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Sample records for 99mtc-tetrofosmin myocardial spect

  1. SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits.

    PubMed

    Chen, Lung-Ching; Lin, Chih-Yuan; Chen, Ing-Jou; Ku, Chi-Tai; Chen, Yen-Kung; Hsu, Bailing

    2016-01-01

    Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions. PMID:26053731

  2. Quantitative Assessment of Myocardial Blood Flow with SPECT.

    PubMed

    Petretta, Mario; Storto, Giovanni; Pellegrino, Teresa; Bonaduce, Domenico; Cuocolo, Alberto

    2015-01-01

    The quantitative assessment of myocardial blood flow (MBF) and coronary flow reserve (CFR) may be useful for the functional evaluation of coronary artery disease, allowing judgment of its severity, tracking of disease progression, and evaluation of the anti-ischemic efficacy of therapeutic strategies. Quantitative estimates of myocardial perfusion and CFR can be derived from single-photon emission computed tomography (SPECT) myocardial perfusion images by use of equipment, tracers, and techniques that are available in most nuclear cardiology laboratories. However, this method underestimates CFR, particularly at high flow rates. The recent introduction of cardiac-dedicated gamma cameras with solid-state detectors provides very fast perfusion imaging with improved resolution, allowing fast acquisition of serial dynamic images during the first pass of a flow agent. This new technology holds great promise for MBF and CFR quantification with dynamic SPECT. Future studies will clarify the effectiveness of dynamic SPECT flow imaging. PMID:25560327

  3. Recent developments and future prospects of SPECT myocardial perfusion imaging.

    PubMed

    Zaman, Maseeh Uz; Hashmi, Ibrahim; Fatima, Nosheen

    2010-10-01

    Myocardial perfusion SPECT imaging is the most commonly performed functional imaging for assessment of coronary artery disease. High diagnostic accuracy and incremental prognostic value are the major benefits while suboptimal spatial resolution and significant radiation exposure are the main limitations. Its ability to detect hemodynamic significance of lesions seen on multidetector CT angiogram (MDCTA) has paved the path for a successful marriage between anatomical and functional imaging modalities in the form of hybrid SPECT/MDCTA system. In recent years, there have been enormous efforts by industry and academia to develop new SPECT imaging systems with better sensitivity, resolution, compact design and new reconstruction algorithms with ability to improve image quality and resolution. Furthermore, expected arrival of Tc-99m-labeled deoxyglucose in next few years would further strengthen the role of SPECT in imaging hibernating myocardium. In view of these developments, it seems that SPECT would enjoy its pivotal role in spite of major threat to be replaced by fluorine-18-labeled positron emission tomography perfusion and glucose metabolism imaging agents. PMID:20652774

  4. [Usefulness of 201Tl/123I-BMIPP myocardial SPECT to evaluate myocardial viability and area at risk in acute myocardial infarction--comparison with 201Tl/99mTc-PYP dual SPECT].

    PubMed

    Isobe, N; Toyama, T; Hoshizaki, H; Oshima, S; Taniguchi, K

    1997-04-01

    To evaluate the area at risk and the myocardial viability of acute myocardial infarction (AMI), we compared rest 123I-beta-methyl iodophenyl pentadecanoic acid (123I-BMIPP) and 201Tl myocardial SPECT with 201Tl/99mTc-PYP dual SPECT (D-SPECT) in 65 patients (mean age 64 +/- 11 years) with AMI. D-SPECT was performed in 3 to 5 days, 123I-BMIPP myocardial SPECT in 5 to 7 days, and left ventriculography on 1 month after onset of AMI. Furthermore, 201Tl/123I-BMIPP myocardial SPECT and left ventriculography were performed on 4 months after onset of AMI. The area which showed the reduced 123I-BMIPP uptake was larger than that showed the accumulation of 99mTc-PYP. The improvement of regional wall motion on 4 months after onset of AMI tended to be more closely correlated with the existence of discrepancy zone between 201Tl and 123I-BMIPP uptake than that of overlap zone between 201Tl and 99mTc-PYP uptake in acute period. We conclude that 201Tl/123I-BMIPP myocardial SPECT is more useful to evaluate the area at risk and myocardial viability of AMI than D-SPECT. PMID:9183144

  5. Comparison of myocardial contrast echocardiography with NC100100 and 99mTc sestamibi SPECT for detection of resting myocardial perfusion abnormalities in patients with previous myocardial infarction

    PubMed Central

    Jucquois, I; Nihoyannopoulos, P; D'Hondt, A; Roelants, V; Robert, A; Melin, J; Glass, D; Vanoverschelde, J

    2000-01-01

    OBJECTIVE—To determine whether myocardial contrast echocardiography (MCE) following intravenous injection of perfluorocarbon microbubbles permits identification of resting myocardial perfusion abnormalities in patients who have had a previous myocardial infarction.
PATIENTS AND INTERVENTIONS—22 patients (mean (SD) age 66 (11) years) underwent MCE after intravenous injection of NC100100, a novel perfluorocarbon containing contrast agent, and resting 99mTc sestamibi single photon emission computed tomography (SPECT). With both methods, myocardial perfusion was graded semiquantitatively as 1 = normal, 0.5 = mild defect, and 0 = severe defect.
RESULTS—Among the 203 normally contracting segments, 151 (74%) were normally perfused by SPECT and 145 (71%) by MCE. With SPECT, abnormal tracer uptake was mainly found among normally contracting segments from the inferior wall. By contrast, with MCE poor myocardial opacification was noted essentially among the normally contracting segments from the anterior and lateral walls. Of the 142 dysfunctional segments, 87 (61%) showed perfusion defects by SPECT, and 94 (66%) by MCE. With both methods, perfusion abnormalities were seen more frequently among akinetic than hypokinetic segments. MCE correctly identified 81/139 segments that exhibited a perfusion defect by SPECT (58%), and 135/206 segments that were normally perfused by SPECT (66%). Exclusion of segments with attenuation artefacts (defined as abnormal myocardial opacification or sestamibi uptake but normal contraction) by either MCE or SPECT improved both the sensitivity (76%) and the specificity (83%) of the detection of SPECT perfusion defects by MCE.
CONCLUSIONS—The data suggest that MCE allows identification of myocardial perfusion abnormalities in patients who have had a previous myocardial infarction, provided that regional wall motion is simultaneously taken into account.


Keywords: myocardial contrast echocardiography; NC100100

  6. [A case of stunned myocardium: dual SPECT findings similar to acute myocardial infarction (AMI)].

    PubMed

    Itho, K; Kohno, Y; Sudo, Y; Azuma, A; Sugihara, H; Asayama, J; Katsume, H; Nakagawa, M

    1993-02-01

    Emergent cardiac catheterization was performed on a 70-year-old female patient who was admitted for further evaluation of acute myocardial infarction. Coronary angiography didn't reveal any significant stenotic lesion, but levogram showed extensively abnormal contractility around the center of the apex region. On the second hospital day, 99mTc-PYP/201TlCl dual SPECT gave findings similar to those found in acute myocardial infarction, but myocardium--released enzyme stayed within the normal range. Two weeks after, 201TlCl myocardial scintigraphy showed disappearance of the perfusion defect, and normal contractility was observed on the levogram of the chronic phase. Since this case was clinically denied to be myocardial infarction, it was considered a typical case of stunned myocardium which showed prolonged left ventricular abnormal contractility with transient myocardial ischemia. This is a case suggestive for estimations of myocardial reversibility in patients with myocardial perfusion and metabolic disorder in dual SPECT. PMID:8434179

  7. Hotspot quantification of myocardial focal tracer uptake from molecular targeted SPECT/CT images: experimental validation

    NASA Astrophysics Data System (ADS)

    Liu, Yi-Hwa; Sahul, Zakir; Weyman, Christopher A.; Ryder, William J.; Dione, Donald P.; Dobrucki, Lawrence W.; Mekkaoui, Choukri; Brennan, Matthew P.; Hu, Xiaoyue; Hawley, Christi; Sinusas, Albert J.

    2008-03-01

    We have developed a new single photon emission computerized tomography (SPECT) hotspot quantification method incorporating extra cardiac activity correction and hotspot normal limit estimation. The method was validated for estimation accuracy of myocardial tracer focal uptake in a chronic canine model of myocardial infarction (MI). Dogs (n = 4) at 2 weeks post MI were injected with Tl-201 and a Tc-99m-labeled hotspot tracer targeted at matrix metalloproteinases (MMPs). An external point source filled with Tc-99m was used for a reference of absolute radioactivity. Dual-isotope (Tc-99m/Tl-201) SPECT images were acquired simultaneously followed by an X-ray CT acquisition. Dogs were sacrificed after imaging for myocardial gamma well counting. Images were reconstructed with CT-based attenuation correction (AC) and without AC (NAC) and were quantified using our quantification method. Normal limits for myocardial hotspot uptake were estimated based on 3 different schemes: maximum entropy, meansquared-error minimization (MSEM) and global minimization. Absolute myocardial hotspot uptake was quantified from SPECT images using the normal limits and compared with well-counted radioactivity on a segment-by-segment basis (n = 12 segments/dog). Radioactivity was expressed as % injected dose (%ID). There was an excellent correlation (r = 0.78-0.92) between the estimated activity (%ID) derived using the SPECT quantitative approach and well-counting, independent of AC. However, SPECT quantification without AC resulted in the significant underestimation of radioactivity. Quantification using SPECT with AC and the MSEM normal limit yielded the best results compared with well-counting. In conclusion, focal myocardial "hotspot" uptake of a targeted radiotracer can be accurately quantified in vivo using a method that incorporates SPECT imaging with AC, an external reference, background scatter compensation, and a suitable normal limit. This hybrid SPECT/CT approach allows for the serial

  8. EANM procedural guidelines for radionuclide myocardial perfusion imaging with SPECT and SPECT/CT: 2015 revision.

    PubMed

    Verberne, Hein J; Acampa, Wanda; Anagnostopoulos, Constantinos; Ballinger, Jim; Bengel, Frank; De Bondt, Pieter; Buechel, Ronny R; Cuocolo, Alberto; van Eck-Smit, Berthe L F; Flotats, Albert; Hacker, Marcus; Hindorf, Cecilia; Kaufmann, Philip A; Lindner, Oliver; Ljungberg, Michael; Lonsdale, Markus; Manrique, Alain; Minarik, David; Scholte, Arthur J H A; Slart, Riemer H J A; Trägårdh, Elin; de Wit, Tim C; Hesse, Birger

    2015-11-01

    Since the publication of the European Association of Nuclear Medicine (EANM) procedural guidelines for radionuclide myocardial perfusion imaging (MPI) in 2005, many small and some larger steps of progress have been made, improving MPI procedures. In this paper, the major changes from the updated 2015 procedural guidelines are highlighted, focusing on the important changes related to new instrumentation with improved image information and the possibility to reduce radiation exposure, which is further discussed in relation to the recent developments of new International Commission on Radiological Protection (ICRP) models. Introduction of the selective coronary vasodilator regadenoson and the use of coronary CT-contrast agents for hybrid imaging with SPECT/CT angiography are other important areas for nuclear cardiology that were not included in the previous guidelines. A large number of minor changes have been described in more detail in the fully revised version available at the EANM home page: http://eanm.org/publications/guidelines/2015_07_EANM_FINAL_myocardial_perfusion_guideline.pdf . PMID:26290421

  9. SPECT imaging with Tl-201 and Ga-67 in myocardial sarcoidosis

    SciTech Connect

    Kurata, C.; Sakata, K.; Taguchi, T.; Fukumoto, Y.; Miyata, H.; Aoshima, S.; Yamazaki, N. )

    1990-06-01

    Two patients with myocardial sarcoidosis are presented, both of whom underwent SPECT imaging with Tl-201 and Ga-67. The first had Ga-67 myocardial uptake with a Tl-201 defect, which disappeared with corticosteroid therapy. The second had multiple Tl-201 defects without Ga-67 uptake, which persisted despite corticosteroid therapy. Therefore, the combination of Tl-201 and Ga-67 imaging may be useful for recognizing myocardial sarcoidosis and for predicting the response to corticosteroid therapy.

  10. Wiener filtering improves quantification of regional myocardial perfusion with thallium-201 SPECT

    SciTech Connect

    Links, J.M.; Jeremy, R.W.; Dyer, S.M.; Frank, T.L.; Becker, L.C. )

    1990-07-01

    Quantitation of myocardial perfusion with thallium-201 (201Tl) SPECT is limited by finite resolution and image noise. This study examined whether Wiener filtering could improve quantitation of the severity of myocardial perfusion deficits. In 19 anesthetized dogs, adjustable stenoses were placed on the left anterior descending (LAD, n = 12) or circumflex (LCx, n = 7) arteries. Thallium-201 SPECT images were acquired during maximal coronary vasodilation with dipyridamole, and simultaneous measurements of myocardial blood flow were made with microspheres. The relationship between SPECT and microsphere flow deficits in the LAD region was significantly better (p less than 0.05) with Wiener filtering (Y = 0.90X + 0.03, r = 0.78) than with conventional Hanning filtering (Y = 0.66X + 0.34, r = 0.61). Similarly, in the LCx region the relationship between SPECT and microsphere perfusion deficits was better (p less than 0.01) with the Wiener filter (Y = 0.91X + 0.07, r = 0.66) than with the Hanning filter (Y = 0.36X + 0.50, r = 0.40). Wiener filtering improves quantitation of the severity of regional myocardial perfusion deficits, allowing better assessment of the functional significance of coronary artery stenoses.

  11. 3-D surface rendering of myocardial SPECT images segmented by level set technique.

    PubMed

    Lee, Hwun-Jae; Lee, Sangbock

    2012-06-01

    SPECT(single photon emission computed tomography) myocardial imaging is a diagnosis technique that images the region of interest and examines any change induced by disease using a computer after injects intravenously a radiopharmaceutical drug emitting gamma ray and the drug has dispersed evenly in the heart . Myocardial perfusion imaging, which contains functional information, is useful for non-invasive diagnosis of myocardial disease but noises caused by physical factors and low resolution give difficulty in reading the images. In order to help reading myocardial images, this study proposed a method that segments myocardial images and reconstructs the segmented region into a 3D image. To resolve difficulty in reading, we segmented the left ventricle, the region of interest, using a level set and modeled the segmented region into a 3D image. PMID:20839037

  12. Variable Activation of the DNA Damage Response Pathways in Patients Undergoing SPECT Myocardial Perfusion Imaging

    PubMed Central

    Hu, Shijun; Liang, Grace; Ong, Sang-Ging; Han, Leng; Sanchez-Freire, Veronica; Lee, Andrew S.; Vasanawala, Minal; Segall, George; Wu, Joseph C.

    2015-01-01

    Background Although single photon emission computed tomography myocardial perfusion imaging (SPECT MPI) has improved the diagnosis and risk stratification of patients with suspected coronary artery disease, it remains a primary source of low dose radiation exposure for cardiac patients. To determine the biological effects of low dose radiation from SPECT MPI, we measured the activation of the DNA damage response pathways using quantitative flow cytometry and single cell gene expression profiling. Methods and Results Blood samples were collected from patients before and after SPECT MPI (n=63). Overall, analysis of all recruited patients showed no marked differences in the phosphorylation of proteins (H2AX, p53, and ATM) following SPECT. The majority of patients also had either down-regulated or unchanged expression in DNA damage response genes at both 24 and 48 hours post-SPECT. Interestingly, a small subset of patients with increased phosphorylation also had significant up-regulation of genes associated with DNA damage, whereas those with no changes in phosphorylation had significant down-regulation or no difference, suggesting that some patients may potentially be more sensitive to low dose radiation exposure. Conclusions Our findings showed that SPECT MPI resulted in a variable activation of the DNA damage response pathways. Although only a small subset of patients had increased protein phosphorylation and elevated gene expression post-imaging, continued care should be taken to reduce radiation exposure to both patients and operators. PMID:25609688

  13. Gated myocardial perfusion SPECT: basic principles, technical aspects, and clinical applications.

    PubMed

    Paul, Asit K; Nabi, Hani A

    2004-12-01

    Electrocardiographically gated myocardial perfusion SPECT (GSPECT) is a state-of-the-art technique for the combined evaluation of myocardial perfusion and left ventricular function within a single study. It is currently one of the most commonly performed cardiology procedures in a nuclear medicine department. Automation of the image processing and quantification has made this technique highly reproducible, practical, and user friendly in the clinical setting. In patients with coronary artery disease, gating enhances the diagnostic and prognostic capability of myocardial perfusion imaging, provides incremental information over the perfusion data, and has shown potentials for myocardial viability assessment and sequential follow-up after therapy. After reading this article, the readers will understand (a) the general principles of GSPECT and quantitation, (b) the methods of the image acquisition and analysis, (c) validation of GSPECT with other cardiac imaging modalities, and (d) application of the GSPECT-derived functional parameters in the clinical practice. PMID:15576339

  14. Peritoneal fluid causing inferior attenuation on SPECT thallium-201 myocardial imaging in women

    SciTech Connect

    Rab, S.T.; Alazraki, N.P.; Guertler-Krawczynska, E.

    1988-11-01

    On SPECT thallium images, myocardial left ventricular (LV) anterior wall attenuation due to breast tissue is common in women. In contrast, in men, inferior wall counts are normally decreased compared to anterior counts. The purpose of this report is to describe cases of inferior wall attenuation of counts in women caused by peritoneal fluid, not myocardial disease. Twelve consecutive SPECT thallium myocardial studies performed in women on peritoneal dialysis, being evaluated for kidney transplant, were included in this study. For all studies, 3.5 mCi 201Tl were injected intravenously. Thirty-two images were acquired over 180 degrees (45 degrees RAO progressing to 45 degrees LPO) at 40 sec per stop. SPECT images were reviewed in short axis, horizontal long and vertical long axes. Data were also displayed in bullseye format with quantitative comparison to gender-matched normal files. Ten of 12 female patients studied had inferior wall defects on images, confirmed by bullseye display. All patients had approximately 2 liters of peritoneal fluid. Review of planar rotational views showed diaphragm elevation and fluid margin attenuations affecting left ventricular inferior wall. Thus, peritoneal fluid is a cause of inferior attenuation on 201Tl cardiac imaging.

  15. Identification of Angiogenesis Rich-Viable Myocardium using RGD Dimer based SPECT after Myocardial Infarction.

    PubMed

    Lee, Min Su; Park, Hyun Soo; Lee, Byung Chul; Jung, Jae Ho; Yoo, Jung Sun; Kim, Sang Eun

    2016-01-01

    Cardiac healing after myocardial ischemia is a complex biological process. Advances in understanding of wound healing response have paved the way for clinical testing of novel molecular imaging to improve clinical outcomes. A key factor for assessing myocardial viability after ischemic injury is the evaluation of angiogenesis accompanying increased expression of integrin αvβ3. Here, we describe the capability of an αvβ3 integrin-targeting SPECT agent, (99m)Tc-IDA-D-[c(RGDfK)]2, for identification of ischemic but viable myocardium, i.e., hibernating myocardium which is crucial to predict functional recovery after revascularization, the standard care of cardiovascular medicine. In vivo SPECT imaging of rat models with transient coronary occlusion showed significantly high uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 in the ischemic region. Comparative measurements with (201)Tl SPECT and (18)F-FDG PET, then, proved that such prominent uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 exactly matched the hallmark of hibernation, i.e., the perfusion-metabolism mismatch pattern. The uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 was non-inferior to that of (18)F-FDG, confirmed by time-course variation analysis. Immunohistochemical characterization revealed that an intense signal of (99m)Tc-IDA-D-[c(RGDfK)]2 corresponded to the vibrant angiogenic events with elevated expression of αvβ3 integrin. Together, these results establish that (99m)Tc-IDA-D-[c(RGDfK)]2 SPECT can serve as a sensitive clinical measure for myocardial salvage to identify the patients who might benefit most from revascularization. PMID:27283041

  16. Identification of Angiogenesis Rich-Viable Myocardium using RGD Dimer based SPECT after Myocardial Infarction

    PubMed Central

    Lee, Min Su; Park, Hyun Soo; Lee, Byung Chul; Jung, Jae Ho; Yoo, Jung Sun; Kim, Sang Eun

    2016-01-01

    Cardiac healing after myocardial ischemia is a complex biological process. Advances in understanding of wound healing response have paved the way for clinical testing of novel molecular imaging to improve clinical outcomes. A key factor for assessing myocardial viability after ischemic injury is the evaluation of angiogenesis accompanying increased expression of integrin αvβ3. Here, we describe the capability of an αvβ3 integrin-targeting SPECT agent, 99mTc-IDA-D-[c(RGDfK)]2, for identification of ischemic but viable myocardium, i.e., hibernating myocardium which is crucial to predict functional recovery after revascularization, the standard care of cardiovascular medicine. In vivo SPECT imaging of rat models with transient coronary occlusion showed significantly high uptake of 99mTc-IDA-D-[c(RGDfK)]2 in the ischemic region. Comparative measurements with 201Tl SPECT and 18F-FDG PET, then, proved that such prominent uptake of 99mTc-IDA-D-[c(RGDfK)]2 exactly matched the hallmark of hibernation, i.e., the perfusion-metabolism mismatch pattern. The uptake of 99mTc-IDA-D-[c(RGDfK)]2 was non-inferior to that of 18F-FDG, confirmed by time-course variation analysis. Immunohistochemical characterization revealed that an intense signal of 99mTc-IDA-D-[c(RGDfK)]2 corresponded to the vibrant angiogenic events with elevated expression of αvβ3 integrin. Together, these results establish that 99mTc-IDA-D-[c(RGDfK)]2 SPECT can serve as a sensitive clinical measure for myocardial salvage to identify the patients who might benefit most from revascularization. PMID:27283041

  17. A new dynamic myocardial phantom for evaluation of SPECT and PET quantitation in systolic and diastolic conditions

    SciTech Connect

    Dreuille, O. de; Bendriem, B.; Riddell, C.

    1996-12-31

    We present a new dynamic myocardial phantom designed to evaluate SPECT and PET imaging in systolic and diastolic conditions. The phantom includes a thoracic attenuating media and the myocardial wall thickness varying during the scan can be performed. In this study the phantom was used with three different wall thickness characteristic of a systolic, end-diastolic and pathologic end-diastolic condition. The myocardium was filled with {sup 99m}Tc, {sup 18}F and Gd and imaged by SPECT, PET and MRI. SPECT attenuation correction was performed using a modified PET transmission. A bull`s eyes image was obtained for all data and wall ROI were then drawn for analysis. Using MRI as a reference, error from PET, SPECT and attenuation corrected SPECT were calculated. Systolic PET performances agree with MRI. Quantitation loss due to wall thickness reduction compared to the systole. Attenuation correction in SPECT leads to significant decrease of the error both in systole (from 29% to 14%) and diastole (35% to 22%). This is particularly sensitive for septum and inferior walls. SPECT residual errors (14% in systole and 22% in pathologic end-diastole) are likely caused by scatter, noise and depth dependent resolution effect. The results obtained with this dynamical phantom demonstrate the quantitation improvement achieved in SPECT with attenuation correction and also reinforce the need for variable resolution correction in addition to attenuation correction.

  18. Reducing CT dose in myocardial perfusion SPECT/CT.

    PubMed

    O'Shaughnessy, Emma; Dixon, Kat L

    2015-11-01

    The aim of this study was to reduce the radiation dose arising from computed tomography (CT) attenuation correction to single photon emission computed tomography myocardial perfusion imaging studies without adversely affecting its accuracy. Using the Perspex CTDI phantom with the Xi detector to measure dose, CT scans were acquired using the Siemens Symbia T over the full range of CT settings available. Using the default setting 'AECmean', the measured dose at the centre of the phantom was 1.68 mGy and the breast dose from the scout view was 0.30 mGy. The lowest dose was achieved using the dose modulation setting in which the doses were reduced to 1.21 mGy and undetectable (<0.01 mGy), respectively. To observe the effect of changing these settings, 30 patients received a stress scan with default CT settings and a rest scan utilizing single photon emission computed tomography-guided CT and the dose modulation CT settings. Results showed a mean effective dose reduction of 23.6%. The dose reduction was greatest for larger patients, with the largest dose reduction for one patient being 72%. There was no apparent difference in attenuation correction between the two sets of resultant images. These new lower-dose settings are now applied to all clinical myocardial perfusion imaging studies. PMID:26302461

  19. Segmentation of the Left Ventricle in Myocardial Perfusion SPECT Using Active Shape Model

    NASA Astrophysics Data System (ADS)

    Tan, Wooi-Haw; Besar, Rosli

    In the quantification of myocardial perfusion SPECT (MPS), numerous processes are involved. Automation is desired as it will considerably reduce the laboriousness of the underlying tasks. In this paper, we propose a segmentation scheme for the delineation of left ventricle (LV) using the Active Shape Models. Our scheme will reduce the labour-intensiveness in MPS quantification, while still allowing interactive guidance from the medical experts. The proposed scheme has been applied on clinical MPS tomograms in which it has successfully delineated the LV in 94% of the test data. In addition, it has also shown to be more suitable for LV segmentation than the rivaling Active Contour Model.

  20. [ECG-gated myocardial SPECT with 99mTc-MIBI in patients with right ventricular infarction].

    PubMed

    Kumita, S; Mizumura, S; Cho, K; Kijima, T; Kumazaki, T; Tetsuou, Y; Sakai, S; Sano, J; Kusama, Y; Munakata, K

    1996-06-01

    Although 99mTc-pyrophosphate (PYP) myocardial scintigraphy has so far been widely used for the diagnosis of right ventricular infarction, PYP accumulation disappears within one week or so. To evaluate the myocardial condition of the right ventricle alternatively, myocardial SPECT with 99mTc-MIBI was performed in 16 patients with acute inferior left ventricular infarction, and ECG-gated myocardial SPECT data acquisition was accompanied in 14 of 16 patients. Right ventricular perfusion defect was observed in 4 of 16 patients (RVI (+) group), and the remains were negative (RVI (-) group). Then, right ventricular count increase rate (RV %WT) of MIBI from end-diastole to end-systole was calculated using an automated method which was developed for quantification of wall thickening in our laboratory. The RV %WT was conceived to be an objective index representing right ventricular contractility. RVI (+) group (n = 3) as compared with RVI (-) group (n = 11) had significant lower RV %WT (26.7 +/- 3.2 vs. 49.6 +/- 14.2; p < 0.01). In conclusion, ECG-gated myocardial SPECT with MIBI was considered to be useful for assessment of myocardial perfusion and contractility of right ventricle. PMID:8741508

  1. Tl-201 myocardial SPECT in patients with Duchenne's muscular dystrophy: A long-term follow-up

    SciTech Connect

    Nagamachi, S.; Jinnouchi, S.; Ono, S.; Hoshi, H.; Inoue, K.; Watanabe, K. )

    1989-11-01

    Tl-201 SPECT was used to evaluate myocardial involvement in 13 patients with Duchenne's muscular dystrophy. Serial studies of 9 patients were done at two-year intervals. The hypoperfused areas of the left ventricle became more prominent with age and severity.

  2. A comparison of cost functions for data-driven motion estimation in myocardial perfusion SPECT imaging

    NASA Astrophysics Data System (ADS)

    Mukherjee, Joyeeta Mitra; Pretorius, P. H.; Johnson, K. L.; Hutton, Brian F.; King, Michael A.

    2011-03-01

    In myocardial perfusion SPECT imaging patient motion during acquisition causes severe artifacts in about 5% of studies. Motion estimation strategies commonly used are a) data-driven, where the motion may be determined by registration and checking consistency with the SPECT acquisition data, and b) external surrogate-based, where the motion is obtained from a dedicated motion-tracking system. In this paper a data-driven strategy similar to a 2D-3D registration scheme with multiple views is investigated, using a partially reconstructed heart for the 3D model. The partially-reconstructed heart has inaccuracies due to limited angle artifacts resulting from using only a part of the SPECT projections acquired while the patient maintained the same pose. The goal of this paper is to compare the performance of different cost-functions in quantifying consistency with the SPECT projection data in a registration-based scheme for motion estimation as the image-quality of the 3D model degrades. Six intensity-based metrics- Mean-squared difference (MSD), Mutual information (MI), Normalized Mutual information NMI), Pattern intensity (PI), normalized cross-correlation (NCC) and Entropy of the difference (EDI) were studied. Quantitative and qualitative analysis of the performance is reported using Monte-Carlo simulations of a realistic heart phantom including degradation factors such as attenuation, scatter and collimator blurring. Further the image quality of motion-corrected images using data-driven motion estimates was compared to that obtained using the external motion-tracking system in acquisitions of anthropomorphic phantoms and patient studies in a real clinical setting. Pattern intensity and Normalized Mutual Information cost functions were observed to have the best performance in terms of lowest average position error and stability with degradation of image quality of the partial reconstruction in simulations and anthropomorphic phantom acquisitions. In patient studies

  3. Evaluation of Respiratory Motion Effect on Defect Detection in Myocardial Perfusion SPECT: A Simulation Study

    PubMed Central

    Yang, Yu-Wen; Chen, Jyh-Cheng; He, Xin; Wang, Shyh-Jen; Tsui, Benjamin M. W.

    2010-01-01

    The objective of this study is to investigate the effects of respiratory motion (RM) on defect detection in Tc-99m sestamibi myocardial perfusion SPECT (MPS) using a phantom population that includes patient variability. Three RM patterns are included, namely breath-hold, slightly enhanced normal breathing, and deep breathing. For each RM pattern, six 4-D NCAT phantoms were generated, each with anatomical variations. Anterior, lateral and inferior myocardial defects with different sizes and contrasts were inserted. Noise-free SPECT projections were simulated using an analytical projector. Poisson noise was then added to generate noisy realizations. The projection data were reconstructed using the OS-EM algorithm with 1 and 4 subsets/iteration and at 1, 2, 3, 5, 7, and 10 iterations. Short-axis images centered at the centroid of the myocardial defect were extracted, and the channelized Hotelling observer (CHO) was applied for the detection of the defect. The CHO results show that the value of the area under the receiver operating characteristics (ROC) curve (AUC) is affected by the RM amplitude. For all the defect sizes and contrasts studied, the highest or optimal AUC values indicate maximum detectability decrease with the increase of the RM amplitude. With no respiration, the ranking of the optimal AUC value in decreasing order is anterior then lateral, and finally inferior defects. The AUC value of the lateral defect drops more severely as the RM amplitude increases compared to other defect locations. Furthermore, as the RM amplitude increases, the AUC values of the smaller defects drop more quickly than the larger ones. We demonstrated that RM affects defect detectability of MPS imaging. The results indicate that developments of optimal data acquisition methods and RM correction methods are needed to improve the defect detectability in MPS. PMID:21731107

  4. Evaluation of mechanical dyssynchrony and myocardial perfusion using phase analysis of gated SPECT imaging in patients with left ventricular dysfunction

    PubMed Central

    Trimble, Mark A.; Borges-Neto, Salvador; Honeycutt, Emily F.; Shaw, Linda K.; Pagnanelli, Robert; Chen, Ji; Iskandrian, Ami E.; Garcia, Ernest V.; Velazquez, Eric J.

    2010-01-01

    Background Using phase analysis of gated single photon emission computed tomography (SPECT) imaging, we examined the relation between myocardial perfusion, degree of electrical dyssynchrony, and degree of SPECT-derived mechanical dyssynchrony in patients with left ventricular (LV) dysfunction. Methods and Results We retrospectively examined 125 patients with LV dysfunction and ejection fraction of 35% or lower. Fourier analysis converts regional myocardial counts into a continuous thickening function, allowing resolution of phase of onset of myocardial thickening. The SD of LV phase distribution (phase SD) and histogram bandwidth describe LV phase dispersion as a measure of dyssynchrony. Heart failure (HF) patients with perfusion abnormalities ities have higher degrees of dyssynchrony measured by median phase SD (45.5° vs 27.7°, P < .0001) and bandwidth (117.0° vs 73.0°, P = .0006). HF patients with prolonged QRS durations have higher degrees of dyssynchrony measured by median phase SD (54.1° vs 34.7°, P < .0001) and bandwidth (136.5° vs 99.0°, P = .0005). Mild to moderate correlations exist between QRS duration and phase analysis indices of phase SD (r = 0.50) and bandwidth (r = 0.40). Mechanical dyssynchrony (phase SD >43°) was 43.2%. Conclusions HF patients with perfusion abnormalities or prolonged QRS durations QRS durations have higher degrees of mechanical dyssynchrony. Gated SPECT myocardial perfusion imaging can quantify myocardial function, perfusion, and dyssynchrony and may help in evaluating patients for cardiac resynchronization therapy. PMID:18761269

  5. [The diagnostic value of Tc-99m PYP, Tl-201 dual isotope SPECT to predict the viability of damaged myocardium in the acute phase of myocardial infarction--comparison with stress, delayed, and reinjected Tl-201 SPECT].

    PubMed

    Matsuo, H; Watanabe, S; Arai, M; Kotoo, Y; Oohashi, H; Oda, H; Ueno, K; Matsubara, T; Ohno, M; Mori, S

    1991-05-01

    To assess the diagnostic value of Tc-99m PYP, Tl-201 dual isotope SPECT for the evaluation of myocardial viability, segmental comparison between dual isotope SPECT and exercise, delayed, and reinjected Tl study were performed with 18 AMI patients. Among 72 damaged myocardial segments, 48 segments (67%) were judged as viable by chronic phase Tl studies. The segments with severely reduced Tl uptake by dual SPECT showed significantly lower prevalence of viable myocardium than the segments with reduced and normal Tl uptake (p less than 0.001). The segments with PYP accumulation localized to the subendocardium represented the favorable outcome compared with the transmural accumulation (p less than 0.001). And overlap segments show better prognosis than the segments without overlap (p less than 0.05). Most importantly, we can get better predictive accuracy of myocardial scar by dual isotope SPECT than the judgement by Tl or PYP SPECT alone (83.3% vs 77.8%, 68.1%). Thus, we conclude that Tc-99m PYP, Tl-201 dual isotope SPECT is useful to assess the severity of myocardial damage in the acute phase of myocardial infarction. PMID:1653372

  6. Optimization of the filter parameters in (99m)Tc myocardial perfusion SPECT studies: the formulation of flowchart.

    PubMed

    Shibutani, Takayuki; Onoguchi, Masahisa; Yamada, Tomoki; Kamida, Hiroki; Kunishita, Kohei; Hayashi, Yuuki; Nakajima, Tadashi; Kinuya, Seigo

    2016-06-01

    Myocardial perfusion single photon emission computed tomography (SPECT) is typically subject to a variation in image quality due to the use of different acquisition protocols, image reconstruction parameters and image display settings by each institution. One of the principal image reconstruction parameters is the Butterworth filter cut-off frequency, a parameter strongly affecting the quality of myocardial images. The objective of this study was to formulate a flowchart for the determination of the optimal parameters of the Butterworth filter for filtered back projection (FBP), ordered subset expectation maximization (OSEM) and collimator-detector response compensation OSEM (CDR-OSEM) methods using the evaluation system of the myocardial image based on technical grounds phantom. SPECT studies were acquired for seven simulated defects where the average counts of the normal myocardial components of 45° left anterior oblique projections were approximately 10-120 counts/pixel. These SPECT images were then reconstructed by FBP, OSEM and CDR-OSEM methods. Visual and quantitative assessment of short axis images were performed for the defect and normal parts. Finally, we formulated a flowchart indicating the optimal image processing procedure for SPECT images. Correlation between normal myocardial counts and the optimal cut-off frequency could be represented as a regression expression, which had high or medium coefficient of determination. We formulated the flowchart in order to optimize the image reconstruction parameters based on a comprehensive assessment, which enabled us to perform objectively processing. Furthermore, the usefulness of image reconstruction using the flowchart was demonstrated by a clinical case. PMID:27052439

  7. Myocardial Perfusion SPECT Imaging in Dextrocardia with Situs Inversus: A Case Report

    PubMed Central

    Ayeni, Olusegun Akinwale; Malan, Nico; Hammond, Emmanuel Niiboye; Vangu, Mboyo-Di-Tamba Heben

    2016-01-01

    Dextrocardia is a cardiac positional anomaly in which the heart is located in the right hemithorax with its base-to-apex axis directed to the right and caudad. Situs inversus is an autosomal recessive disorder that causes organs in the chest and abdomen to be positioned in a mirror image from their normal position. Dextrocardia may occur in isolation or as part of situs inversus. Similarly, situs inversus may occur with or without dextrocardia. Situs inversus accompanied with dextrocardia (situs inversus totalis) is a rare congenital abnormality occurring in 0.01% of live births. Herein, we present the case of a 35-year-old man with previously diagnosed situs inversus totalis with mirror-image dextrocardia, referred to our facility for diagnosis of coronary artery disease (CAD). The incidence and presentation of CAD in patients with dextrocardia are similar to the normal population. However, considerable attention should be paid to the acquisition of myocardial perfusion scintigraphy and data processing/analysis in this group of patients. The present case highlights the distinctive applications and potential pitfalls of myocardial perfusion single-photon emission computed tomography (SPECT) imaging in patients with dextrocardia. PMID:27408900

  8. Numerical surrogates for human observers in myocardial motion evaluation from SPECT image

    PubMed Central

    Marin, Thibault; Kalayehis, Mahdi M.; Parages, Felipe M.; Brankov, Jovan G.

    2014-01-01

    In medical imaging, the gold standard for image-quality assessment is a task-based approach in which one evaluates human observer performance for a given diagnostic task (e.g., detection of a myocardial perfusion or motion defect). To facilitate practical task-based image-quality assessment, model observers are needed as approximate surrogates for human observers. In cardiac-gated SPECT imaging, diagnosis relies on evaluation of the myocardial motion as well as perfusion. Model observers for the perfusion-defect detection task have been studied previously, but little effort has been devoted toward development of a model observer for cardiac-motion defect detection. In this work describe two model observers for predicting human observer performance in detection of cardiac-motion defects. Both proposed methods rely on motion features extracted using previously reported deformable mesh model for myocardium motion estimation. The first method is based on a Hotelling linear discriminant that is similar in concept to that used commonly for perfusion-defect detection. In the second method, based on relevance vector machines (RVM) for regression, we compute average human observer performance by first directly predicting individual human observer scores, and then using multi reader receiver operating characteristic (ROC) analysis. Our results suggest that the proposed RVM model observer can predict human observer performance accurately, while the new Hotelling motion-defect detector is somewhat less effective. PMID:23981533

  9. Myocardial Perfusion SPECT Imaging in Dextrocardia with Situs Inversus: A Case Report.

    PubMed

    Ayeni, Olusegun Akinwale; Malan, Nico; Hammond, Emmanuel Niiboye; Vangu, Mboyo-Di-Tamba Heben

    2016-01-01

    Dextrocardia is a cardiac positional anomaly in which the heart is located in the right hemithorax with its base-to-apex axis directed to the right and caudad. Situs inversus is an autosomal recessive disorder that causes organs in the chest and abdomen to be positioned in a mirror image from their normal position. Dextrocardia may occur in isolation or as part of situs inversus. Similarly, situs inversus may occur with or without dextrocardia. Situs inversus accompanied with dextrocardia (situs inversus totalis) is a rare congenital abnormality occurring in 0.01% of live births. Herein, we present the case of a 35-year-old man with previously diagnosed situs inversus totalis with mirror-image dextrocardia, referred to our facility for diagnosis of coronary artery disease (CAD). The incidence and presentation of CAD in patients with dextrocardia are similar to the normal population. However, considerable attention should be paid to the acquisition of myocardial perfusion scintigraphy and data processing/analysis in this group of patients. The present case highlights the distinctive applications and potential pitfalls of myocardial perfusion single-photon emission computed tomography (SPECT) imaging in patients with dextrocardia. PMID:27408900

  10. [Preliminary evaluation of the effect of an attenuation correction method in myocardial perfusion SPECT].

    PubMed

    Cortés-Blanco, A; Fujii, C; Goris, M L

    1999-12-01

    We propose a method to assess an attenuation correction method in myocardial perfusion SPECT. Three types of images are obtained: one resulting from a classic acquisition and filtered back-projection (classic), and those resulting from acquisition with a transmission source and an iterative reconstruction, with (music) or without (hybrid) the attenuation correction factored in to compare the three types of images and classify them as normal or abnormal, a three dimensional inter-patient quantitative comparison method was used. Differences were computed as fractions of the myocardial volume in which density differences are significant by population standards. In 7 cases the cumulative difference between prone and supine in hybrid images was 124 and 45 in music images. In 10 cases the cumulative difference between classic vs music images was 279, and between classic and hybrid 86. The AC changed 4/12 cases from abnormal to normal. The attenuation correction effect was concentrated on the septal and inferior walls, but neither exclusively nor evenly among patients. The attenuation correction effectively minimizes attenuation effects by a factor of 2.7, due to a correction of at least 69%. The correction has a small but substantial effect on the results. PMID:10611567

  11. Biphasic thallium 201 SPECT-imaging for the noninvasive diagnosis of myocardial perfusion abnormalities in a child with Kawasaki disease--a case report

    SciTech Connect

    Hausdorf, G.; Nienaber, C.A.; Spielman, R.P.

    1988-02-01

    The mucocutaneous lymph node syndrome (Kawasaki disease) is of increasing importance for the pediatric cardiologist, for coronary aneurysms with the potential of thrombosis and subsequent stenosis can develop in the course of the disease. The authors report a 2 1/2-year-old female child in whom, fourteen months after the acute phase of Kawasaki disease, myocardial infarction occurred. Biphasic thallium 201 SPECT-imaging using dipyridamole depicted anterior wall ischemia and inferolateral infarction. This case demonstrates that noninvasive vasodilation-redistribution thallium 201 SPECT-imaging has the potential to predict reversible myocardial perfusion defects and myocardial necrosis, even in small infants with Kawasaki disease.

  12. Prevalence and predictors of mechanical dyssynchrony as defined by phase analysis in patients with left ventricular dysfunction undergoing gated SPECT myocardial perfusion imaging

    PubMed Central

    Samad, Zainab; Atchley, Allen E.; Trimble, Mark A.; Sun, Jie-Lena; Shaw, Linda K.; Pagnanelli, Robert; Chen, Ji; Garcia, Ernest V.; Iskandrian, Ami E.; Velazquez, Eric J.; Borges-Neto, Salvador

    2011-01-01

    Background A novel method to quantify dyssynchrony using phase analysis of single-photon emission computed tomography (SPECT) myocardial perfusion imaging has been developed. We sought to determine the prevalence of SPECT-derived mechanical dyssynchrony, and we report clinical variables which predict mechanical dyssynchrony in patients with left ventricular dysfunction. Methods We used a count-based Fourier analysis method to convert the regional myocardial counts from discrete frames per cardiac cycle into a continuous thickening function which allows resolution of the phase of the onset of myocardial contraction. The standard deviation of left ventricular phases (Phase SD) describes the regional phase dispersion as a measure of dyssynchrony. Significant dyssynchrony was defined as Phase SD ≥ 43°. 260 patients with left ventricular ejection fraction ≤35% were examined. Results The prevalence of mechanical dyssynchrony in the entire cohort of patients studied was 52%. Univariate predictors of Phase SD were age (P = .03), black race (P = .0005), QRS duration, EF, EDV, summed stress score (SSS), and summed rest score (SRS) (all P = <.0001). Black race, male gender, QRS EF, and SRS were independent predictors of SPECT-based mechanical dyssynchrony. Conclusions Significant SPECT-based mechanical dyssynchrony is relatively common among patients with left ventricular dysfunction. In a population of patients with predominantly ischemic heart disease referred for SPECT, a reduced EF, increasing QRS duration, severity and extent of myocardial scar on SPECT imaging are independent predictors of mechanical dyssynchrony and may serve to identify patients for dyssynchrony screening. PMID:21082299

  13. Use of the cavity-to-myocardial count ratio with Tc-99m sestamibi myocardial perfusion SPECT to predict reduced left ventricular function

    SciTech Connect

    Heerden, B.B. van; Heerden, P.D.R. van; Wasserman, H.J.

    1994-05-01

    In patients with left ventricular dysfunction, the left ventricular cavity appears abnormally photopenic on SPECT images, both with T1-201 and Tc-99m sestamibi showed a linear correlation between the cavity-to-myocardial count ratio (C/M ratio) and left ventricular ejection fraction (LVEF) with T1-201 SPECT. Using an exercise ratio of 0.4 as the lower limit of normal, they could predict a reduced LVEF with a sensitivity of 83% and specificity of 78%. The purpose of our study was to ascertain whether the C/M ratio could also be used as an indicator of LVEF when using Tc-99m sestamibi as imaging agent.

  14. Myocardial infarct size quantification in mice by SPECT using a novel algorithm independent of a normal perfusion database

    PubMed Central

    2012-01-01

    Background There is a growing interest in developing non-invasive imaging techniques permitting infarct size (IS) measurements in mice. The aim of this study was to validate the high-resolution rodent Linoview single photon emission computed tomography (SPECT) system for non-invasive measurements of IS in mice by using a novel algorithm independent of a normal database, in comparison with histology. Methods Eleven mice underwent a left coronary artery ligature. Seven days later, animals were imaged on the SPECT 2h30 after injection of 173 ± 27 MBq of Tc-99m-sestamibi. Mice were subsequently killed, and their hearts were excised for IS determination with triphenyltetrazolium chloride (TTC) staining. SPECT images were reconstructed using the expectation maximization maximum likelihood algorithm, and the IS was calculated using a novel algorithm applied on the 20-segment polar map provided by the commercially available QPS software (Cedars-Sinai Medical Center, CA, USA). This original method is attractive by the fact that it does not require the implementation of a normal perfusion database. Results Reconstructed images allowed a clear delineation of the left ventricles borders in all mice. No significant difference was found between mean IS determined by SPECT and by TTC staining [37.9 ± 17.5% vs 35.6 ± 17.2%, respectively (P = 0.10)]. Linear regression analysis showed an excellent correlation between IS measured on the SPECT images and IS obtained with TTC staining (y = 0.95x + 0.03 (r = 0.97; P < 0.0001)), without bias, as demonstrated by the Bland-Altman plot. Conclusion Our results demonstrate the accuracy of the method for the measurement of myocardial IS in mice with the Linoview SPECT system. PMID:23272995

  15. [Quantitative assessment of the infarct size with the unfolded map method of 201Tl myocardial SPECT in patient with acute myocardial infarction].

    PubMed

    Kubota, M

    1992-03-01

    The unfolded map method of 201Tl single photon emission computed tomography (SPECT) was evaluated as to the ability to quantify and the clinical reliability in estimation of infarct size. At first, the following results were obtained in basic experiments using thoracic phantom: 1) the defect area estimated by the unfolded map method was well correlated with the real defect area in spite of overestimation of the defect area, when the defect area was determined by an isocount method (below 80% of maximum count) (y = 1.941 + 2.29x, r = 0.971, p less than 0.001); 2) the defect volume estimated by short-axis images of 201Tl SPECT was closely correlated with real defect volume in spite of overestimation of defect volume (y = 0.762 + 2.156x, r = 0.982, p less than 0.001); 3) when the defect area was estimated by division of the defect volume by the mean myocardial compartment thickness, it was closely correlated with real defect area (y = 0.946 + 1.232x, r = 0.990, p less than 0.001); 4) when the volume was calculated from the summation of voxels in the regions districted by isocount threshold level at each section of the 99mTc SPECT, the optimal isocount threshold level (percentage to maximum count) was 55%. In addition, the clinical reliability of the unfolded map method as infarct sizing was evaluated in 26 patients with acute myocardial infarction by comparing it with enzymatic method, Bull's eye method, and 99mTc pyrophosphate (PYP) SPECT method. In 14 first attack cases of patient without right ventricular infarction, infarct area (IA) of the unfolded map method correlated most closely with the accumulated creatine kinase MB isoenzyme release (CK-MBr) (r = 0.897), compared with the extent score (ES) (r = 0.853) and the severity score (SS) (r = 0.871) of Bull's eye method and the infarct volume (IV) (r = 0.595) of 99mTc PYP SPECT. In conclusion, although the unfolded map method of 201Tl SPECT has the tendency which overestimate infarct size, it is accurate and

  16. [Clinical usefulness of 201Tl/99mTc-PYP dual myocardial quantitative gated SPECT program using low-dose dobutamine loading in assessment of myocardial viability in patient with acute myocardial infarction--a case report].

    PubMed

    Irie, Hidekazu; Ito, Kazuki; Koide, Masahiro; Taniguchi, Takuya; Yokoi, Hirokazu; Nakamura, Reo; Kinoshita, Noriyuki; Hashimoto, Tetsuo; Tamaki, Shunichi; Sawada, Takahisa; Azuma, Akihiro; Matsubara, Hiroaki

    2006-05-01

    An 86-year-old man with chest pain was admitted to our hospital. Coronary angiography revealed 99% stenosis of the mid segment of the left anterior descending coronary artery, therefore, a coronary stent was implanted. Immediately after the stent implantation, 99% stenosis occurred at the proximal site of the 1st diagonal artery because of stent jeal. On the 4th hospital day, ECG-gated 201TL/99mTc-PYP dual myocardial quantitative gated SPECT was performed at rest and during low-dose dobutamine loading. The 201Tl scintigraphy revealed moderately reduced uptake in the anterior, septal and apical walls, and 99mTc-PYP uptake was observed in the mid-anterior wall. A three-dimensional surface display of gated 201Tl SPECT images showed severe hypokinesis in the anterior, septal and apical walls at rest. On the other hand, during low-dose dobutamine loading, improved wall motion was observed in the basal anterior and septal walls, while no change was observed in the midanterior and apical wall movements. Three-dimensional surface display of gated 201Tl/99mTc-PYP dual SPECT images revealed similar patterns of wall motion as those of gated 201Tl SPECT images at rest. During low-dose dobutamine loading, on the other hand, a three-dimensional surface display of gated 201Tl/99mTc-PYP dual SPECT images revealed improved wall motion in the basal anterior, septal and apical walls, but worsened wall motion of the mid-anterior wall. After 6 months, a follow-up coronary angiography revealed no re-stenosis of the stent, but 99% stenosis at the proximal aspect of the 1st diagonal artery. Left ventriculography revealed improved wall motion in the apex and akinesis of the mid-anterior wall. These wall motion findings were similar to those visualized in the three-dimensional surface display of gated 201Tl/99mTc-PYP dual SPECT images during low-dose dobutamine loading in the acute phase. These results suggest that 201Tl/99mTc-PYP dual myocardial quantitative gated SPECT using low

  17. Applying the J-optimal channelized quadratic observer to SPECT myocardial perfusion defect detection

    NASA Astrophysics Data System (ADS)

    Kupinski, Meredith K.; Clarkson, Eric; Ghaly, Michael; Frey, Eric C.

    2016-03-01

    To evaluate performance on a perfusion defect detection task from 540 image pairs of myocardial perfusion SPECT image data we apply the J-optimal channelized quadratic observer (J-CQO). We compare AUC values of the linear Hotelling observer and J-CQO when the defect location is fixed and when it occurs in one of two locations. As expected, when the location is fixed a single channels maximizes AUC; location variability requires multiple channels to maximize the AUC. The AUC is estimated from both the projection data and reconstructed images. J-CQO is quadratic since it uses the first- and second- order statistics of the image data from both classes. The linear data reduction by the channels is described by an L x M channel matrix and in prior work we introduced an iterative gradient-based method for calculating the channel matrix. The dimensionality reduction from M measurements to L channels yields better estimates of these sample statistics from smaller sample sizes, and since the channelized covariance matrix is L x L instead of M x M, the matrix inverse is easier to compute. The novelty of our approach is the use of Jeffrey's divergence (J) as the figure of merit (FOM) for optimizing the channel matrix. We previously showed that the J-optimal channels are also the optimum channels for the AUC and the Bhattacharyya distance when the channel outputs are Gaussian distributed with equal means. This work evaluates the use of J as a surrogate FOM (SFOM) for AUC when these statistical conditions are not satisfied.

  18. Design of a digital phantom population for myocardial perfusion SPECT imaging research

    PubMed Central

    Ghaly, Michael; Du, Yong; Fung, George S.K.; Tsui, Benjamin M.W.; Links, Jonathan M.; Frey, Eric

    2014-01-01

    Digital phantoms and Monte Carlo (MC) simulations have become important tools for optimizing and evaluating instrumentation, acquisition and processing methods for myocardial perfusion SPECT (MPS). In this work, we designed a new adult digital phantom population and generated corresponding Tc-99m and Tl-201 projections for use in MPS research. The population is based on the 3D XCAT phantom with organ parameters sampled from the Emory PET Torso Model Database. Phantoms included 3 variations each in body size, heart size, and subcutaneous adipose tissue level, for a total of 27 phantoms of each gender. The SimSET Monte Carlo code and angular response functions were used to model interactions in the body and the collimator-detector system, respectively. We divided each phantom into seven organs, each simulated separately, allowing use of post-simulation summing to efficiently model uptake variations. Also, we adapted and used a criterion based on the relative Poisson effective count level to determine the required number of simulated photons for each simulated organ. This technique provided a quantitative estimate of the true noise in the simulated projection data, including residual MC simulation noise. Projections were generated in 1 keV wide energy windows from 48-184 keV assuming perfect energy resolution to permit study of the effects of window width, energy resolution, and crosstalk in the context of dual isotope MPS. We have developed a comprehensive method for efficiently simulating realistic projections for a realistic population of phantoms in the context of MPS imaging. The new phantom population and realistic database of simulated projections will be useful in performing mathematical and human observer studies to evaluate various acquisition and processing methods such as optimizing the energy window width, investigating the effect of energy resolution on image quality and evaluating compensation methods for degrading factors such as crosstalk in the

  19. Optimal left ventricular lead position assessed with phase analysis on gated myocardial perfusion SPECT

    PubMed Central

    Boogers, Mark J.; Chen, Ji; van Bommel, Rutger J.; Borleffs, C. Jan Willem; Dibbets-Schneider, Petra; van der Hiel, Bernies; Al Younis, Imad; Schalij, Martin J.; van der Wall, Ernst E.; Garcia, Ernest V.

    2010-01-01

    Purpose The aim of the current study was to evaluate the relationship between the site of latest mechanical activation as assessed with gated myocardial perfusion SPECT (GMPS), left ventricular (LV) lead position and response to cardiac resynchronization therapy (CRT). Methods The patient population consisted of consecutive patients with advanced heart failure in whom CRT was currently indicated. Before implantation, 2-D echocardiography and GMPS were performed. The echocardiography was performed to assess LV end-systolic volume (LVESV), LV end-diastolic volume (LVEDV) and LV ejection fraction (LVEF). The site of latest mechanical activation was assessed by phase analysis of GMPS studies and related to LV lead position on fluoroscopy. Echocardiography was repeated after 6 months of CRT. CRT response was defined as a decrease of ≥15% in LVESV. Results Enrolled in the study were 90 patients (72% men, 67±10 years) with advanced heart failure. In 52 patients (58%), the LV lead was positioned at the site of latest mechanical activation (concordant), and in 38 patients (42%) the LV lead was positioned outside the site of latest mechanical activation (discordant). CRT response was significantly more often documented in patients with a concordant LV lead position than in patients with a discordant LV lead position (79% vs. 26%, p<0.01). After 6 months, patients with a concordant LV lead position showed significant improvement in LVEF, LVESV and LVEDV (p<0.05), whereas patients with a discordant LV lead position showed no significant improvement in these variables. Conclusion Patients with a concordant LV lead position showed significant improvement in LV volumes and LV systolic function, whereas patients with a discordant LV lead position showed no significant improvements. PMID:20953608

  20. Design of a digital phantom population for myocardial perfusion SPECT imaging research.

    PubMed

    Ghaly, Michael; Du, Yong; Fung, George S K; Tsui, Benjamin M W; Links, Jonathan M; Frey, Eric

    2014-06-21

    Digital phantoms and Monte Carlo (MC) simulations have become important tools for optimizing and evaluating instrumentation, acquisition and processing methods for myocardial perfusion SPECT (MPS). In this work, we designed a new adult digital phantom population and generated corresponding Tc-99m and Tl-201 projections for use in MPS research. The population is based on the three-dimensional XCAT phantom with organ parameters sampled from the Emory PET Torso Model Database. Phantoms included three variations each in body size, heart size, and subcutaneous adipose tissue level, for a total of 27 phantoms of each gender. The SimSET MC code and angular response functions were used to model interactions in the body and the collimator-detector system, respectively. We divided each phantom into seven organs, each simulated separately, allowing use of post-simulation summing to efficiently model uptake variations. Also, we adapted and used a criterion based on the relative Poisson effective count level to determine the required number of simulated photons for each simulated organ. This technique provided a quantitative estimate of the true noise in the simulated projection data, including residual MC simulation noise. Projections were generated in 1 keV wide energy windows from 48-184 keV assuming perfect energy resolution to permit study of the effects of window width, energy resolution, and crosstalk in the context of dual isotope MPS. We have developed a comprehensive method for efficiently simulating realistic projections for a realistic population of phantoms in the context of MPS imaging. The new phantom population and realistic database of simulated projections will be useful in performing mathematical and human observer studies to evaluate various acquisition and processing methods such as optimizing the energy window width, investigating the effect of energy resolution on image quality and evaluating compensation methods for degrading factors such as crosstalk

  1. Design of a digital phantom population for myocardial perfusion SPECT imaging research

    NASA Astrophysics Data System (ADS)

    Ghaly, Michael; Du, Yong; Fung, George S. K.; Tsui, Benjamin M. W.; Links, Jonathan M.; Frey, Eric

    2014-06-01

    Digital phantoms and Monte Carlo (MC) simulations have become important tools for optimizing and evaluating instrumentation, acquisition and processing methods for myocardial perfusion SPECT (MPS). In this work, we designed a new adult digital phantom population and generated corresponding Tc-99m and Tl-201 projections for use in MPS research. The population is based on the three-dimensional XCAT phantom with organ parameters sampled from the Emory PET Torso Model Database. Phantoms included three variations each in body size, heart size, and subcutaneous adipose tissue level, for a total of 27 phantoms of each gender. The SimSET MC code and angular response functions were used to model interactions in the body and the collimator-detector system, respectively. We divided each phantom into seven organs, each simulated separately, allowing use of post-simulation summing to efficiently model uptake variations. Also, we adapted and used a criterion based on the relative Poisson effective count level to determine the required number of simulated photons for each simulated organ. This technique provided a quantitative estimate of the true noise in the simulated projection data, including residual MC simulation noise. Projections were generated in 1 keV wide energy windows from 48-184 keV assuming perfect energy resolution to permit study of the effects of window width, energy resolution, and crosstalk in the context of dual isotope MPS. We have developed a comprehensive method for efficiently simulating realistic projections for a realistic population of phantoms in the context of MPS imaging. The new phantom population and realistic database of simulated projections will be useful in performing mathematical and human observer studies to evaluate various acquisition and processing methods such as optimizing the energy window width, investigating the effect of energy resolution on image quality and evaluating compensation methods for degrading factors such as crosstalk in

  2. Performance of Myocardial Perfusion Imaging Using Multi-focus Fan Beam Collimator with Resolution Recovery Reconstruction in a Comparison with Conventional SPECT

    PubMed Central

    Matsutomo, Norikazu; Nagaki, Akio; Sasaki, Masayuki

    2014-01-01

    Objective(s): IQ-SPECT is an advanced high-speed SPECT modality for myocardial perfusion imaging (MPI), which uses a multi-focus fan beam collimator with resolution recovery reconstruction. The aim of this study was to compare IQ-SPECT with conventional SPECT in terms of performance, based on standard clinical protocols. In addition, we examined the concordance between conventional and IQ_SPECT in patients with coronary artery disease (CAD). Methods: Fifty-three patients, undergoing rest-gated MPI for the evaluation of known or suspected CAD, were enrolled in this study. In each patient, conventional SPECT (99mTc-tetrofosmin, 9.6 min and 201Tl, 12.9 min) was performed, immediately followed by IQ-SPECT, using a short acquisition time (4.3 min for 99mTc-tetrofosmin and 6.2 min for 201Tl). A quantitative analysis was performed on an MPI polar map, using a 20-segment model of the left ventricle. An automated analysis by gated SPECT was carried out to determine the left ventricular volume and function including end-diastolic volume (EDV), end-systolic volume (ESV), and left ventricular ejection fraction (LVEF). The degree of concordance between conventional SPECT and IQ-SPECT images was evaluated according to linear regression and Bland-Altman analyses. Results: The segmental percent uptake exhibited a significant correlation between IQ-SPECT and conventional SPECT (P<0.05). The mean differences in 99mTc-tetrofosmin studies were 1.1±6.6% (apex), 2.8±5.7% (anterior wall), 2.9±6.2% (septal wall), 4.9±6.7% (lateral wall), and 1.8±5.6% (inferior wall). Meanwhile, regarding the 201Tl-SPECT studies, these values were 1.6±6.9%, 2.0±6.6%, 2.1±5.9%, 3.3±7.2%, and 2.4±5.8%, respectively. Although the mean LVEF in IQ-SPECT tended to be higher than that observed in conventional SPECT (conventional SPECT=64.8±11.8% and IQ-SPECT=68.3±12.1% for 99mTc-tetrofosmin; conventional SPECT= 56.0±11.7% and IQ-SPECT=61.5±12.2% for 201Tl), quantitative parameters were not

  3. Optimization and comparison of simultaneous and separate acquisition protocols for dual isotope myocardial perfusion SPECT

    NASA Astrophysics Data System (ADS)

    Ghaly, Michael; Links, Jonathan M.; Frey, Eric C.

    2015-07-01

    Dual-isotope simultaneous-acquisition (DISA) rest-stress myocardial perfusion SPECT (MPS) protocols offer a number of advantages over separate acquisition. However, crosstalk contamination due to scatter in the patient and interactions in the collimator degrade image quality. Compensation can reduce the effects of crosstalk, but does not entirely eliminate image degradations. Optimizing acquisition parameters could further reduce the impact of crosstalk. In this paper we investigate the optimization of the rest Tl-201 energy window width and relative injected activities using the ideal observer (IO), a realistic digital phantom population and Monte Carlo (MC) simulated Tc-99m and Tl-201 projections as a means to improve image quality. We compared performance on a perfusion defect detection task for Tl-201 acquisition energy window widths varying from 4 to 40 keV centered at 72 keV for a camera with a 9% energy resolution. We also investigated 7 different relative injected activities, defined as the ratio of Tc-99m and Tl-201 activities, while keeping the total effective dose constant at 13.5 mSv. For each energy window and relative injected activity, we computed the IO test statistics using a Markov chain Monte Carlo (MCMC) method for an ensemble of 1,620 triplets of fixed and reversible defect-present, and defect-absent noisy images modeling realistic background variations. The volume under the 3-class receiver operating characteristic (ROC) surface (VUS) was estimated and served as the figure of merit. For simultaneous acquisition, the IO suggested that relative Tc-to-Tl injected activity ratios of 2.6-5 and acquisition energy window widths of 16-22% were optimal. For separate acquisition, we observed a broad range of optimal relative injected activities from 2.6 to 12.1 and acquisition energy window of widths 16-22%. A negative correlation between Tl-201 injected activity and the width of the Tl-201 energy window was observed in these ranges. The results

  4. MRI measurements of left ventricular systolic wall thickening compared to regional myocardial perfusion as determined by 201Tl SPECT in patients with coronary artery disease.

    PubMed

    Kleinhans, E; Altehoefer, C; Arnold, C; Buell, U; vom Dahl, J; Uebis, R

    1991-04-01

    Magnetic resonance imaging (MRI) of the left ventricle (LV) is an excellent method of measuring systolic wall thickening (SWT). The aim of the present study was (a) to describe a new approach for measurement of SWT and (b) to define the relationship between SWT and regional myocardial perfusion as determined by 201Tl SPECT. 79 patients -51 with and 28 without history of earlier myocardial infarction - underwent SPECT and, within the next two weeks. MRI. End-diastolic and end-systolic spin echo images were obtained by a reduced permutation technique. For MRI measurements, only long-axis sections through the LV in the equatorial plane were used. Slice orientation was selected according to the findings of SPECT, imaging the infarcted wall segment by single or double angulation. At 7 equidistant points around the LV wall SWT was measured and compared with the corresponding regional myocardial uptake values from SPECT in percent of maximal perfusion. Wall thickness of the anterior wall was normal. Because the majority of myocardial infarctions were posterior-inferior (55%), thickness of the posterior wall was markedly decreased. A close relationship of perfusion to SWT was found. Higher perfusion areas (greater than 50% of maximal TI uptake) corresponded with normal SWT (greater than 3.0 mm), a marked decrease of SWT (less than 1 mm) was found in areas with perfusion deficits (less than 40%). Thus, a 201TI uptake value at rest of 41-50% of the respective myocardial maximum acts as a threshold by discriminating normal from severely reduced SWT. PMID:2047242

  5. Quantitative Upright–Supine High-Speed SPECT Myocardial Perfusion Imaging for Detection of Coronary Artery Disease: Correlation with Invasive Coronary Angiography

    PubMed Central

    Nakazato, Ryo; Tamarappoo, Balaji K.; Kang, Xingping; Wolak, Arik; Kite, Faith; Hayes, Sean W.; Thomson, Louise E.J.; Friedman, John D.; Berman, Daniel S.; Slomka, Piotr J.

    2011-01-01

    A recently developed camera system for high-speed SPECT (HS-SPECT) myocardial perfusion imaging shows excellent correlation with conventional SPECT. Our goal was to test the diagnostic accuracy of an automated quantification of combined upright and supine myocardial SPECT for detection of coronary artery disease (CAD) (≥70% luminal diameter stenosis or, in left main coronary artery, ≥50% luminal diameter stenosis) in comparison to invasive coronary angiography (ICA). Methods We studied 142 patients undergoing upright and supine HS-SPECT, including 56 consecutive patients (63% men; mean age 6 ± SD, 64 ± 13 y; 45% exercise stress) without known CAD who underwent diagnostic ICA within 6 mo of HS-SPECT and 86 consecutive patients with a low likelihood of CAD. Reference limits for upright and supine HS-SPECT were created from studies of patients with a low likelihood of CAD. Automated software adopted from supine–prone analysis was used to quantify the severity and extent of perfusion abnormality and was expressed as total perfusion deficit (TPD). TPD was obtained for upright (U-TPD), supine (S-TPD), and combined upright–supine acquisitions (C-TPD). Stress U-TPD ≥ 5%, S-TPD ≥ 5%, and C-TPD ≥ 3% myocardium were considered abnormal for per-patient analysis, and U-TPD, S-TPD, and C-TPD ≥ 2% in each coronary artery territory were considered abnormal for per-vessel analysis. Results On a per-patient basis, the sensitivity was 91%, 88%, and 94% for U-TPD, S-TPD, and C-TPD, respectively, and specificity was 59%, 73%, and 86% for U-TPD, S-TPD, and C-TPD, respectively. C-TPD had a larger area under the receiver-operating-characteristic curve than U-TPD or S-TPD for identification of stenosis ≥ 70% (0.94 vs. 0.88 and 0.89, P < 0.05 and not significant, respectively). On a per-vessel basis, the sensitivity was 67%, 66%, and 69% for U-TPD, S-TPD, and C-TPD, respectively, and specificity was 91%, 94%, and 97% for U-TPD, S-TPD, and C-TPD, respectively (P = 0

  6. Normal qualitative and quantitative Tc-99m sestamibi myocardial SPECT: spectrum of intramyocardial distribution during exercise and at rest.

    PubMed

    Lette, J; Caron, M; Cerino, M; McNamara, D; Metayer, S; D'Aoust, S; Eybalin, M C; Levesseur, A; Grégoire, J; Arsenault, A

    1994-04-01

    Exercise myocardial perfusion imaging with Tc-99m sestaMIBI is routinely used to detect underlying coronary stenoses. Ischemia is diagnosed in regions that display decreased tracer uptake during exercise as compared to rest. Tc-99m sestaMIBI SPECT images of 42 healthy volunteers were assessed both qualitatively (tomographic slices) and quantitatively (sectored polar map) for potential sources of misinterpretation. On the myocardial tomographic slices, the most common culprit artifacts were diaphragmatic attenuation and bowel interposition, which caused fixed or reversible "perfusion defects" in the inferior and posterior regions (in 19/35 abnormal segments), and artifacts related to the presence and shift of hot spots (observed in 11/28 men; in women, they were more difficult to demonstrate because of the overriding effect of breast attenuation). Hot spots shifts between exercise and rest usually resulted in pseudo-reversible defects in the anterolateral and lateral walls. The quantified polar map display of the myocardium showed a physiologic decrease in sestaMIBI activity in the basal anterolateral and basal posterolateral areas in men during exercise. There are many normal variants that may mimic coronary artery disease on tomographic sestaMIBI images. Before reporting an area of decreased activity as either a fixed or reversible perfusion defect, the interpreter should ensure that it does not represent an artifact or a normal variation in the intramyocardial distribution of sestaMIBI during exercise. PMID:8004868

  7. Myocardial blood flow measurement with a conventional dual-head SPECT/CT with spatiotemporal iterative reconstructions - a clinical feasibility study

    PubMed Central

    Alhassen, Fares; Nguyen, Nhan; Bains, Sukhkarn; Gould, Robert G; Seo, Youngho; Bacharach, Stephen L; Song, Xiyun; Shao, Lingxiong; Gullberg, Grant T; Aparici, Carina Mari

    2014-01-01

    Cardiac single photon emission computed tomography (SPECT) cameras typically rotate too slowly around a patient to capture changes in the blood pool activity distribution and provide accurate kinetic parameters. A spatiotemporal iterative reconstruction method to overcome these limitations was investigated. Dynamic rest/stress 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) SPECT/CT was performed along with reference standard rest/stress dynamic positron emission tomography (PET/CT) 13N-NH3 in five patients. The SPECT data were reconstructed using conventional and spatiotemporal iterative reconstruction methods. The spatiotemporal reconstruction yielded improved image quality, defined here as a statistically significant (p<0.01) 50% contrast enhancement. We did not observe a statistically significant difference between the correlations of the conventional and spatiotemporal SPECT myocardial uptake K 1 values with PET K 1 values (r=0.25, 0.88, respectively) (p<0.17). These results indicate the clinical feasibility of quantitative, dynamic SPECT/CT using 99mTc-MIBI and warrant further investigation. Spatiotemporal reconstruction clearly provides an advantage over a conventional reconstruction in computing K 1. PMID:24380045

  8. Simultaneous Tc-99m/I-123 Dual Radionuclide Myocardial Perfusion/Innervation Imaging Using Siemens IQ-SPECT with SMARTZOOM Collimator

    PubMed Central

    Du, Yong; Bhattacharya, Manojeet; Frey, Eric. C.

    2014-01-01

    Simultaneous dual-radionuclide myocardial perfusion/innervation SPECT imaging can provide important information about mismatch between scar tissue and denervated regions. The Siemens IQ-SPECT system developed for cardiac imaging uses a multifocal SMARTZOOM collimator to achieve a four-fold sensitivity for the cardiac region compared to a typical parallel-hole low-energy high-resolution collimator but without the data truncation that can result with conventional converging-beam collimators. The increased sensitivity allows shorter image acquisition times or reduced patient dose, making IQ-SPECT ideal for simultaneous dual-radionuclide SPECT, where reduced administrated activity is desirable in order to reduce patient radiation exposure. However, crosstalk is a major factor affecting the image quality in dual-radionuclide imaging. In this work we developed a model-based method that can estimate and compensate for the crosstalk in IQ-SPECT data. The crosstalk model takes into account interactions in the object and collimator-detector system. Scatter in the object was modeled using the effective source scatter estimation technique (ESSE), previously developed to model scatter with parallel-hole collimators. The geometric collimator detector response was analytically modeled in the IQ-SPECT projector. The estimated crosstalk was then compensated for in an iterative reconstruction process. The new method was validated with data from both Monte Carlo simulation and physical phantom experiments. The results showed that the estimated crosstalk was in good agreement with simulated and measured results. After model-based compensation the images from simultaneous dual-radionuclide acquisitions were similar in quality to those from single radionuclide acquisitions that did not have crosstalk contamination. The proposed model-based method can be used to improve simultaneous dual-radionuclide images acquired using IQ-SPECT. This work also demonstrates that ESSE scatter modeling

  9. Simultaneous Tc-99m/I-123 dual-radionuclide myocardial perfusion/innervation imaging using Siemens IQ-SPECT with SMARTZOOM collimator

    NASA Astrophysics Data System (ADS)

    Du, Yong; Bhattacharya, Manojeet; Frey, Eric C.

    2014-06-01

    Simultaneous dual-radionuclide myocardial perfusion/innervation SPECT imaging can provide important information about the mismatch between scar tissue and denervated regions. The Siemens IQ-SPECT system developed for cardiac imaging uses a multifocal SMARTZOOM collimator to achieve a four-fold sensitivity for the cardiac region, compared to a typical parallel-hole low-energy high-resolution collimator, but without the data truncation that can result with conventional converging-beam collimators. The increased sensitivity allows shorter image acquisition times or reduced patient dose, making IQ-SPECT ideal for simultaneous dual-radionuclide SPECT, where reduced administrated activity is desirable in order to reduce patient radiation exposure. However, crosstalk is a major factor affecting the image quality in dual-radionuclide imaging. In this work we developed a model-based method that can estimate and compensate for the crosstalk in IQ-SPECT data. The crosstalk model takes into account interactions in the object and collimator-detector system. Scatter in the object was modeled using the effective source scatter estimation technique (ESSE), previously developed to model scatter with parallel-hole collimators. The geometric collimator-detector response was analytically modeled in the IQ-SPECT projector. The estimated crosstalk was then compensated for in an iterative reconstruction process. The new method was validated with data from both Monte Carlo simulations and physical phantom experiments. The results showed that the estimated crosstalk was in good agreement with simulated and measured results. After model-based compensation the images from simultaneous dual-radionuclide acquisitions were similar in quality to those from single-radionuclide acquisitions that did not have crosstalk contamination. The proposed model-based method can be used to improve simultaneous dual-radionuclide images acquired using IQ-SPECT. This work also demonstrates that ESSE scatter

  10. Simultaneous Tc-99m/I-123 dual-radionuclide myocardial perfusion/innervation imaging using Siemens IQ-SPECT with SMARTZOOM collimator.

    PubMed

    Du, Yong; Bhattacharya, Manojeet; Frey, Eric C

    2014-06-01

    Simultaneous dual-radionuclide myocardial perfusion/innervation SPECT imaging can provide important information about the mismatch between scar tissue and denervated regions. The Siemens IQ-SPECT system developed for cardiac imaging uses a multifocal SMARTZOOM collimator to achieve a four-fold sensitivity for the cardiac region, compared to a typical parallel-hole low-energy high-resolution collimator, but without the data truncation that can result with conventional converging-beam collimators. The increased sensitivity allows shorter image acquisition times or reduced patient dose, making IQ-SPECT ideal for simultaneous dual-radionuclide SPECT, where reduced administrated activity is desirable in order to reduce patient radiation exposure. However, crosstalk is a major factor affecting the image quality in dual-radionuclide imaging. In this work we developed a model-based method that can estimate and compensate for the crosstalk in IQ-SPECT data. The crosstalk model takes into account interactions in the object and collimator-detector system. Scatter in the object was modeled using the effective source scatter estimation technique (ESSE), previously developed to model scatter with parallel-hole collimators. The geometric collimator-detector response was analytically modeled in the IQ-SPECT projector. The estimated crosstalk was then compensated for in an iterative reconstruction process. The new method was validated with data from both Monte Carlo simulations and physical phantom experiments. The results showed that the estimated crosstalk was in good agreement with simulated and measured results. After model-based compensation the images from simultaneous dual-radionuclide acquisitions were similar in quality to those from single-radionuclide acquisitions that did not have crosstalk contamination. The proposed model-based method can be used to improve simultaneous dual-radionuclide images acquired using IQ-SPECT. This work also demonstrates that ESSE scatter

  11. Development of 4D mathematical observer models for the task-based evaluation of gated myocardial perfusion SPECT

    NASA Astrophysics Data System (ADS)

    Lee, Taek-Soo; Frey, Eric C.; Tsui, Benjamin M. W.

    2015-04-01

    This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical observer model extends the conventional channelized Hotelling observer (CHO) based on a set of 2D spatial channels and the second is a proposed model that uses a set of 4D space-time channels. Simulated projection data were generated using the 4D NURBS-based cardiac-torso (NCAT) phantom with 16 gates/cardiac cycle. The activity distribution modelled uptake of 99mTc MIBI with normal perfusion and a regional wall motion defect. An analytical projector was used in the simulation and the filtered backprojection (FBP) algorithm was used in image reconstruction followed by spatial and temporal low-pass filtering with various cut-off frequencies. Then, we extracted 2D image slices from each time frame and reorganized them into a set of cine images. For the first model, we applied 2D spatial channels to the cine images and generated a set of feature vectors that were stacked for the images from different slices of the heart. The process was repeated for each of the 1,024 noise realizations, and CHO and receiver operating characteristics (ROC) analysis methodologies were applied to the ensemble of the feature vectors to compute areas under the ROC curves (AUCs). For the second model, a set of 4D space-time channels was developed and applied to the sets of cine images to produce space-time feature vectors to which the CHO methodology was applied. The AUC values of the second model showed better agreement (Spearman’s rank correlation (SRC) coefficient = 0.8) to human observer results than those from the first model (SRC coefficient = 0.4). The agreement with human observers indicates the proposed 4D mathematical observer model provides a good predictor of the

  12. Development of 4D mathematical observer models for the task-based evaluation of gated myocardial perfusion SPECT.

    PubMed

    Lee, Taek-Soo; Frey, Eric C; Tsui, Benjamin M W

    2015-04-01

    This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical observer model extends the conventional channelized Hotelling observer (CHO) based on a set of 2D spatial channels and the second is a proposed model that uses a set of 4D space-time channels. Simulated projection data were generated using the 4D NURBS-based cardiac-torso (NCAT) phantom with 16 gates/cardiac cycle. The activity distribution modelled uptake of (99m)Tc MIBI with normal perfusion and a regional wall motion defect. An analytical projector was used in the simulation and the filtered backprojection (FBP) algorithm was used in image reconstruction followed by spatial and temporal low-pass filtering with various cut-off frequencies. Then, we extracted 2D image slices from each time frame and reorganized them into a set of cine images. For the first model, we applied 2D spatial channels to the cine images and generated a set of feature vectors that were stacked for the images from different slices of the heart. The process was repeated for each of the 1,024 noise realizations, and CHO and receiver operating characteristics (ROC) analysis methodologies were applied to the ensemble of the feature vectors to compute areas under the ROC curves (AUCs). For the second model, a set of 4D space-time channels was developed and applied to the sets of cine images to produce space-time feature vectors to which the CHO methodology was applied. The AUC values of the second model showed better agreement (Spearman's rank correlation (SRC) coefficient = 0.8) to human observer results than those from the first model (SRC coefficient = 0.4). The agreement with human observers indicates the proposed 4D mathematical observer model provides a good predictor of the

  13. Diagnostic value of 18F-FDG PET in the assessment of myocardial viability in coronary artery disease: A comparative study with 99mTc SPECT and echocardiography

    PubMed Central

    Al Moudi, Mansour; Sun, Zhong-Hua

    2014-01-01

    Objective To investigate the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in the assessment of myocardial viability in patients with known coronary artery disease (CAD) when compared to 99mTc single photon emission computed tomography (SPECT) and echocardiography, with invasive coronary angiography as the gold standard. Methods Thirty patients with diagnosed CAD met the selection criteria, with 10 of them (9 men, mean age 59.5 ± 10.5 years) undergoing all of these imaging procedures consisting of SPECT and PET, echocardiography and invasive angiography. Diagnostic sensitivity of these less invasive modalities for detection of myocardial viability was compared to invasive coronary angiography. Inter- and intra-observer agreement was assessed for diagnostic performance of SPECT and PET. Results Of all patients with proven CAD, 50% had triple vessel disease. Diagnostic sensitivity of SPECT, PET and echocardiography was 90%, 100% and 80% at patient-based assessment, respectively. Excellent agreement was achieved between inter-observer and intra-observer agreement of the diagnostic value of SPECT and PET in myocardial viability (k = 0.9). Conclusion 18F-FDG PET has high diagnostic value in the assessment of myocardial viability in patients with known CAD when compared to SPECT and echocardiography. Further studies based on a large cohort with incorporation of 18F-FDG PET into patient management are warranted. PMID:25278972

  14. Quantitative reconstruction for myocardial perfusion SPECT: an efficient approach by depth-dependent deconvolution and matrix rotation.

    PubMed

    Ye, J; Liang, Z; Harrington, D P

    1994-08-01

    An efficient reconstruction method for myocardial perfusion single-photon emission computed tomography (SPECT) has been developed which compensates simultaneously for attenuation, scatter, and resolution variation. The scattered photons in the primary-energy-window measurements are approximately removed by subtracting the weighted scatter-energy-window samples. The resolution variation is corrected by deconvolving the subtracted data with the detector-response kernel in frequency space using the depth-dependent frequency relation. The attenuated photons are compensated by recursively tracing the attenuation factors through the object-specific attenuation map. An experimental chest phantom with defects inside myocardium was used to test the method. The attenuation map of the phantom was reconstructed from transmission scans using a flat external source and a high-resolution parallel-hole collimator of a single-detector system. The detector-response kernel was approximated from measurements of a point source in air at several depths from the collimator surface. The emission data were acquired by the same detector setting. A computer simulation using similar protocols as in the experiment was performed. Both the simulation and experiment showed significant improvement in quantification with the proposed method, as compared to the conventional filtered-backprojection technique. The quantitative gain by the additional deconvolution was demonstrated. The computation time was less than 20 min on a HP/730 desktop computer for reconstruction of a 1282 x 64 array from 128 projections of 128 x 64 samples. PMID:15551566

  15. Comparison of Gated SPECT Myocardial Perfusion Imaging with Echocardiography for the Measurement of Left Ventricular Volumes and Ejection Fraction in Patients With Severe Heart Failure

    PubMed Central

    Shojaeifard, Maryam; Ghaedian, Tahereh; Yaghoobi, Nahid; Malek, Hadi; Firoozabadi, Hasan; Bitarafan-Rajabi, Ahmad; Haghjoo, Majid; Amin, Ahmad; Azizian, Nasrin; Rastgou, Feridoon

    2015-01-01

    Background: Gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is known as a feasible tool for the measurement of left ventricular ejection fraction (EF) and volumes, which are of great importance in the management and follow-up of patients with coronary artery diseases. However, considering the technical shortcomings of SPECT in the presence of perfusion defect, the accuracy of this method in heart failure patients is still controversial. Objectives: The aim of the present study was to compare the results from gated SPECT MPI with those from echocardiography in heart failure patients to compare echocardiographically-derived left ventricular dimension and function data to those from gated SPECT MPI in heart failure patients. Patients and Methods: Forty-one patients with severely reduced left ventricular systolic function (EF ≤ 35%) who were referred for gated SPECT MPI were prospectively enrolled. Quantification of EF, end-diastolic volume (EDV), and end-systolic volume (ESV) was performed by using quantitative gated spect (QGS) (QGS, version 0.4, May 2009) and emory cardiac toolbox (ECTb) (ECTb, revision 1.0, copyright 2007) software packages. EF, EDV, and ESV were also measured with two-dimensional echocardiography within 3 days after MPI. Results: A good correlation was found between echocardiographically-derived EF, EDV, and ESV and the values derived using QGS (r = 0.67, r = 0.78, and r = 0.80 for EF, EDV, and ESV, respectively; P < 0.001) and ECTb (r = 0.68, 0.79, and r = 0.80 for EF, EDV, and ESV, respectively; P < 0.001). However, Bland-Altman plots indicated significantly different mean values for EF, 11.4 and 20.9 using QGS and ECTb, respectively, as compared with echocardiography. ECTb-derived EDV was also significantly higher than the EDV measured with echocardiography and QGS. The highest correlation between echocardiography and gated SPECT MPI was found for mean values of ESV different. Conclusions: Gated

  16. Correlation of myocardial perfusion SPECT with invasive and computed tomography coronary angiogram

    PubMed Central

    Shelley, S.; Indirani, M.; Sathyamurthy, I.; Subramanian, K.; Priti, N.; Harshad, K.; Padma, D.

    2012-01-01

    Background The consequences of atherosclerosis can be detected by multislice computed tomography (MSCT), invasive coronary angiogram (CAG) and the resultant myocardial ischaemia by myocardial perfusion single photon emission computed tomography (MPS). In this study an attempt is made to compare MSCT with MPS and also to compare the MSCT findings with that of invasive CAG in patients suspected to have coronary artery disease (CAD). Materials and methods A total of 99 patients suspected to have CAD underwent both MSCT and MPS with 99mTc sestamibi. The MSCT studies were classified as having no CAD, significant CAD (>50% diameter stenosis), and insignificant CAD (<50% diameter stenosis). Myocardial perfusion single photon emission computed tomography was reported as normal and reversible ischaemia. In a subgroup of 33 patient invasive CAG was done. Results In 99 patients, 396 coronaries were evaluated with MSCT and MPS. Coronary artery calcium scoring (CACS) in these patient ranged from 0 to 2200. No CAD was noted in 128 (32%) coronaries but MPS was found abnormal in 9 (7%) coronaries. Insignificant CAD was noted in 169 (43%) coronaries amongst which reversible ischaemia was noted in 23 (14%). Significant CAD was noted in 99 (25%) coronaries of which only 54 (55%) were MPS positive for reversible ischaemia. The MSCT has a negative predictive value (NPV) of 97%. When MSCT was normal, MPS was almost normal, but the reverse was not true. That is when MPS was normal MSCT was not always normal but showed lesion of insignificant obstruction. In the subset of 33 patients, who underwent invasive angiogram, 132 coronaries were evaluated. Coronary angiogram showed 48 coronaries (36%) to have significant CAD (>50% diameter stenosis). Multislice computed tomography correlated well in 46 (84%) with P value of <0.001 (χ2-test) but for 9 (16%) showing overestimation due to increased CACS (>800). Myocardial perfusion single photon emission computed tomography was normal in 15 (27

  17. Review: comparison of PET rubidium-82 with conventional SPECT myocardial perfusion imaging

    PubMed Central

    Ghotbi, Adam A; Kjær, Andreas; Hasbak, Philip

    2014-01-01

    Nuclear cardiology has for many years been focused on gamma camera technology. With ever improving cameras and software applications, this modality has developed into an important assessment tool for ischaemic heart disease. However, the development of new perfusion tracers has been scarce. While cardiac positron emission tomography (PET) so far largely has been limited to centres with on-site cyclotron, recent developments with generator produced perfusion tracers such as rubidium-82, as well as an increasing number of PET scanners installed, may enable a larger patient flow that may supersede that of gamma camera myocardial perfusion imaging. PMID:24028171

  18. [The Optimal Reconstruction Parameters by Scatter and Attenuation Corrections Using Multi-focus Collimator System in Thallium-201 Myocardial Perfusion SPECT Study].

    PubMed

    Shibutani, Takayuki; Onoguchi, Masahisa; Funayama, Risa; Nakajima, Kenichi; Matsuo, Shinro; Yoneyama, Hiroto; Konishi, Takahiro; Kinuya, Seigo

    2015-11-01

    The aim of this study was to reveal the optimal reconstruction parameters of ordered subset conjugates gradient minimizer (OSCGM) by no correction (NC), attenuation correction (AC), and AC+scatter correction (ACSC) using IQ-single photon emission computed tomography (SPECT) system in thallium-201 myocardial perfusion SPECT. Myocardial phantom acquired two patterns, with or without defect. Myocardial images were performed 5-point scale visual score and quantitative evaluations using contrast, uptake, and uniformity about the subset and update (subset×iteration) of OSCGM and the full width at half maximum (FWHM) of Gaussian filter by three corrections. We decided on optimal reconstruction parameters of OSCGM by three corrections. The number of subsets to create suitable images were 3 or 5 for NC and AC, 2 or 3 for ACSC. The updates to create suitable images were 30 or 40 for NC, 40 or 60 for AC, and 30 for ACSC. Furthermore, the FWHM of Gaussian filters were 9.6 mm or 12 mm for NC and ACSC, 7.2 mm or 9.6 mm for AC. In conclusion, the following optimal reconstruction parameters of OSCGM were decided; NC: subset 5, iteration 8 and FWHM 9.6 mm, AC: subset 5, iteration 8 and FWHM 7.2 mm, ACSC: subset 3, iteration 10 and FWHM 9.6 mm. PMID:26596202

  19. Systematic evaluation of 99mTc-tetrofosmin versus 99mTc-sestamibi to study murine myocardial perfusion in small animal SPECT/CT

    PubMed Central

    2012-01-01

    Background The “back-translation” of clinically available protocols to measure myocardial perfusion to preclinical imaging in mouse models of human disease is attractive for basic biomedical research. With respect to single-photon emission computed tomography (SPECT) approaches, clinical myocardial perfusion imaging protocols are established with different 99mTc-labeled perfusion tracers; however, studies evaluating and optimizing protocols for these tracers in high-resolution pinhole SPECT in mice are lacking. This study aims at evaluating two clinically available 99mTc-labeled myocardial perfusion tracers (99mTc-sestamibi vs. 99mTc-Tetrofosmin) in mice using four different imaging protocols. Methods Adult C57BL/6 male mice were injected with 99mTc-sestamibi (MIBI) or 99mTc-Tetrofosmin (TETRO) (4 MBq/g body weight) either intravenously through the tail vein (n = 5) or retroorbitally (n = 5) or intraperitoneally (i.p.) under anesthesia (n = 3) or i.p. in an awake state (n = 3) at rest. Immediately after injection, a multi-frame single-photon emission computed tomography/computed tomography (SPECT/CT) acquisition was initiated with six subsequent time frames of 10 min each. Reconstructed images of the different protocols were assessed and compared by visual analysis by experts and by time-activity-curves generated from regions-of-interest for various organs (normalized uptake values). Results Visually assessing overall image quality, the best image quality was found for MIBI for both intravenous injection protocols, whereas TETRO only had comparable image quality after retroorbital injections. These results were confirmed by quantitative analysis where left ventricular (LV) uptake of MIBI after tail vein injections was found significantly higher for all time points accompanied with a significantly slower washout of 16% for MIBI vs. 33% for TETRO (p = 0.009) from 10 to 60 min post injection (PI). Interestingly, LV washout from 10 to 60 min PI

  20. Collimator optimization in myocardial perfusion SPECT using the ideal observer and realistic background variability for lesion detection and joint detection and localization tasks.

    PubMed

    Ghaly, Michael; Du, Yong; Links, Jonathan M; Frey, Eric C

    2016-03-01

    In SPECT imaging, collimators are a major factor limiting image quality and largely determine the noise and resolution of SPECT images. In this paper, we seek the collimator with the optimal tradeoff between image noise and resolution with respect to performance on two tasks related to myocardial perfusion SPECT: perfusion defect detection and joint detection and localization. We used the Ideal Observer (IO) operating on realistic background-known-statistically (BKS) and signal-known-exactly (SKE) data. The areas under the receiver operating characteristic (ROC) and localization ROC (LROC) curves (AUCd, AUCd+l), respectively, were used as the figures of merit for both tasks. We used a previously developed population of 54 phantoms based on the eXtended Cardiac Torso Phantom (XCAT) that included variations in gender, body size, heart size and subcutaneous adipose tissue level. For each phantom, organ uptakes were varied randomly based on distributions observed in patient data. We simulated perfusion defects at six different locations with extents and severities of 10% and 25%, respectively, which represented challenging but clinically relevant defects. The extent and severity are, respectively, the perfusion defect's fraction of the myocardial volume and reduction of uptake relative to the normal myocardium. Projection data were generated using an analytical projector that modeled attenuation, scatter, and collimator-detector response effects, a 9% energy resolution at 140 keV, and a 4 mm full-width at half maximum (FWHM) intrinsic spatial resolution. We investigated a family of eight parallel-hole collimators that spanned a large range of sensitivity-resolution tradeoffs. For each collimator and defect location, the IO test statistics were computed using a Markov Chain Monte Carlo (MCMC) method for an ensemble of 540 pairs of defect-present and -absent images that included the aforementioned anatomical and uptake variability. Sets of test statistics were computed

  1. Collimator optimization in myocardial perfusion SPECT using the ideal observer and realistic background variability for lesion detection and joint detection and localization tasks

    NASA Astrophysics Data System (ADS)

    Ghaly, Michael; Du, Yong; Links, Jonathan M.; Frey, Eric C.

    2016-03-01

    In SPECT imaging, collimators are a major factor limiting image quality and largely determine the noise and resolution of SPECT images. In this paper, we seek the collimator with the optimal tradeoff between image noise and resolution with respect to performance on two tasks related to myocardial perfusion SPECT: perfusion defect detection and joint detection and localization. We used the Ideal Observer (IO) operating on realistic background-known-statistically (BKS) and signal-known-exactly (SKE) data. The areas under the receiver operating characteristic (ROC) and localization ROC (LROC) curves (AUCd, AUCd+l), respectively, were used as the figures of merit for both tasks. We used a previously developed population of 54 phantoms based on the eXtended Cardiac Torso Phantom (XCAT) that included variations in gender, body size, heart size and subcutaneous adipose tissue level. For each phantom, organ uptakes were varied randomly based on distributions observed in patient data. We simulated perfusion defects at six different locations with extents and severities of 10% and 25%, respectively, which represented challenging but clinically relevant defects. The extent and severity are, respectively, the perfusion defect’s fraction of the myocardial volume and reduction of uptake relative to the normal myocardium. Projection data were generated using an analytical projector that modeled attenuation, scatter, and collimator-detector response effects, a 9% energy resolution at 140 keV, and a 4 mm full-width at half maximum (FWHM) intrinsic spatial resolution. We investigated a family of eight parallel-hole collimators that spanned a large range of sensitivity-resolution tradeoffs. For each collimator and defect location, the IO test statistics were computed using a Markov Chain Monte Carlo (MCMC) method for an ensemble of 540 pairs of defect-present and -absent images that included the aforementioned anatomical and uptake variability. Sets of test statistics were

  2. Application of task-based measures of image quality to optimization and evaluation of three-dimensional reconstruction-based compensation methods in myocardial perfusion SPECT.

    PubMed

    Frey, Eric C; Gilland, Karen L; Tsui, Benjamin M W

    2002-09-01

    In this paper, we apply the channelized Hotelling observer (CHO) using a defect detection task to the optimization and evaluation of three-dimensional iterative reconstruction-based compensation methods for myocardial perfusion single-photon emission computed tomography (SPECT). We used a population of 24 mathematical cardiac-torso phantoms that realistically model the activity and attenuation distribution in three classes of patients: females, and males with flat diaphragms and raised diaphragms. Projection data were generated and subsequently reconstructed using methods based on the ordered subsets-expectation maximization (OSEM) algorithm. The methods evaluated included compensation for attenuation, detector response blurring, and scatter in various combinations. We applied the CHO to optimize the number of iterations for OSEM and the cutoff frequency and order of a three-dimensional postreconstruction Butterworth filter. Using the optimal parameters, we then compared the compensation methods. The index of comparison in these studies was the area under the receiver operating characteristics curve (AUC) for the CHO. We found that attenuation compensation with either detector response or scatter compensation gave statistically significant increases in the AUC compared to attenuation compensation alone. The greatest increase in the AUC occurred when all three compensations were applied. These results indicate that compensation for detector response and scatter, in addition to attenuation compensation, will improve defect detectability in myocardial SPECT images. PMID:12564872

  3. Creation of an ensemble of simulated cardiac cases and a human observer study: tools for the development of numerical observers for SPECT myocardial perfusion imaging

    NASA Astrophysics Data System (ADS)

    O'Connor, J. Michael; Pretorius, P. Hendrik; Gifford, Howard C.; Licho, Robert; Joffe, Samuel; McGuiness, Matthew; Mehurg, Shannon; Zacharias, Michael; Brankov, Jovan G.

    2012-02-01

    Our previous Single Photon Emission Computed Tomography (SPECT) myocardial perfusion imaging (MPI) research explored the utility of numerical observers. We recently created two hundred and eighty simulated SPECT cardiac cases using Dynamic MCAT (DMCAT) and SIMIND Monte Carlo tools. All simulated cases were then processed with two reconstruction methods: iterative ordered subset expectation maximization (OSEM) and filtered back-projection (FBP). Observer study sets were assembled for both OSEM and FBP methods. Five physicians performed an observer study on one hundred and seventy-nine images from the simulated cases. The observer task was to indicate detection of any myocardial perfusion defect using the American Society of Nuclear Cardiology (ASNC) 17-segment cardiac model and the ASNC five-scale rating guidelines. Human observer Receiver Operating Characteristic (ROC) studies established the guidelines for the subsequent evaluation of numerical model observer (NO) performance. Several NOs were formulated and their performance was compared with the human observer performance. One type of NO was based on evaluation of a cardiac polar map that had been pre-processed using a gradient-magnitude watershed segmentation algorithm. The second type of NO was also based on analysis of a cardiac polar map but with use of a priori calculated average image derived from an ensemble of normal cases.

  4. Geometric feature-based multimodal image registration of contrast-enhanced cardiac CT with gated myocardial perfusion SPECT

    PubMed Central

    Woo, Jonghye; Slomka, Piotr J.; Dey, Damini; Cheng, Victor Y.; Hong, Byung-Woo; Ramesh, Amit; Berman, Daniel S.; Karlsberg, Ronald P.; Kuo, C.-C. Jay; Germano, Guido

    2009-01-01

    Purpose: Cardiac computed tomography (CT) and single photon emission computed tomography (SPECT) provide clinically complementary information in the diagnosis of coronary artery disease (CAD). Fused anatomical and physiological data acquired sequentially on separate scanners can be coregistered to accurately diagnose CAD in specific coronary vessels. Methods: A fully automated registration method is presented utilizing geometric features from a reliable segmentation of gated myocardial perfusion SPECT (MPS) volumes, where regions of myocardium and blood pools are extracted and used as an anatomical mask to de-emphasize the inhomogeneities of intensity distribution caused by perfusion defects and physiological variations. A multiresolution approach is employed to represent coarse-to-fine details of both volumes. The extracted voxels from each level are aligned using a similarity measure with a piecewise constant image model and minimized using a gradient descent method. The authors then perform limited nonlinear registration of gated MPS to adjust for phase differences by automatic cardiac phase matching between CT and MPS. For phase matching, they incorporate nonlinear registration using thin-plate-spline-based warping. Rigid registration has been compared with manual alignment (n=45) on 20 stress/rest MPS and coronary CTA data sets acquired from two different sites and five stress CT perfusion data sets. Phase matching was also compared to expert visual assessment. Results: As compared with manual alignment obtained from two expert observers, the mean and standard deviation of absolute registration errors of the proposed method for MPS were4.3±3.5, 3.6±2.6, and 3.6±2.1mm for translation and 2.1±3.2°, 0.3±0.8°, and 0.7±1.2° for rotation at site A and 3.8±2.7, 4.0±2.9, and 2.2±1.8mm for translation and 1.1±2.0°, 1.6±3.1°, and 1.9±3.8° for rotation at site B. The results for CT perfusion were 3.0±2.9, 3.5±2.4, and 2.8±1.0mm for translation and 3

  5. High Concordance Between Mental Stress–Induced and Adenosine-Induced Myocardial Ischemia Assessed Using SPECT in Heart Failure Patients: Hemodynamic and Biomarker Correlates

    PubMed Central

    Wawrzyniak, Andrew J.; Dilsizian, Vasken; Krantz, David S.; Harris, Kristie M.; Smith, Mark F.; Shankovich, Anthony; Whittaker, Kerry S.; Rodriguez, Gabriel A.; Gottdiener, John; Li, Shuying; Kop, Willem; Gottlieb, Stephen S.

    2016-01-01

    Mental stress can trigger myocardial ischemia, but the prevalence of mental stress–induced ischemia in congestive heart failure (CHF) patients is unknown. We characterized mental stress–induced and adenosine-induced changes in myocardial perfusion and neurohormonal activation in CHF patients with reduced left-ventricular function using SPECT to precisely quantify segment-level myocardial perfusion. Methods Thirty-four coronary artery disease patients (mean age ± SD, 62 ± 10 y) with CHF longer than 3 mo and ejection fraction less than 40% underwent both adenosine and mental stress myocardial perfusion SPECT on consecutive days. Mental stress consisted of anger recall (anger-provoking speech) followed by subtraction of serial sevens. The presence and extent of myocardial ischemia was quantified using the conventional 17-segment model. Results Sixty-eight percent of patients had 1 ischemic segment or more during mental stress and 81% during adenosine. On segment-by-segment analysis, perfusion with mental stress and adenosine were highly correlated. No significant differences were found between any 2 time points for B-type natriuretic peptide, tumor necrosis factor-α, IL-1b, troponin, vascular endothelin growth factor, IL-17a, matrix metallopeptidase-9, or C-reactive protein. However, endothelin-1 and IL-6 increased, and IL-10 decreased, between the stressor and 30 min after stress. Left-ventricular end diastolic dimension was 179 ± 65 mL at rest and increased to 217 ± 71 after mental stress and 229 ± 86 after adenosine (P < 0.01 for both). Resting end systolic volume was 129 ± 60 mL at rest and increased to 158 ± 66 after mental stress (P < 0.05) and 171 ± 87 after adenosine (P < 0.07), with no significant differences between adenosine and mental stress. Ejection fraction was 30 ± 12 at baseline, 29 ± 11 with mental stress, and 28 ± 10 with adenosine (P = not significant). Conclusion There was high concordance between ischemic perfusion defects induced

  6. Comparison of image quality, myocardial perfusion, and LV function between standard imaging and single-injection ultra-low-dose imaging using a high-efficiency SPECT camera: the MILLISIEVERT study

    PubMed Central

    Einstein, Andrew J.; Blankstein, Ron; Andrews, Howard; Fish, Mathews; Padgett, Richard; Hayes, Sean W.; Friedman, John D.; Qureshi, Mehreen; Rakotoarivelo, Harivony; Slomka, Piotr; Nakazato, Ryo; Bokhari, Sabahat; Di Carli, Marcello; Berman, Daniel S.

    2015-01-01

    SPECT myocardial perfusion imaging (MPI) plays a central role in coronary artery disease diagnosis; but concerns exist regarding its radiation burden. Compared to standard Anger-SPECT (A-SPECT) cameras, new high-efficiency (HE) cameras with specialized collimators and solid-state cadmium-zinc-telluride detectors offer potential to maintain image quality (IQ), while reducing administered activity and thus radiation dose to patients. No previous study has compared IQ, interpretation, total perfusion deficit (TPD), or ejection fraction (EF) in patients receiving both ultra-low-dose (ULD) imaging on a HE-SPECT camera and standard low-dose (SLD) A-SPECT imaging. Methods We compared ULD-HE-SPECT to SLD-A-SPECT imaging by dividing the rest dose in 101 patients at 3 sites scheduled to undergo clinical A-SPECT MPI using a same day rest/stress Tc-99m protocol. Patients received HE-SPECT imaging following an initial ~130 MBq (3.5mCi) dose, and SLD-A-SPECT imaging following the remainder of the planned dose. Images were scored visually by 2 blinded readers for IQ and summed rest score (SRS). TPD and EF were assessed quantitatively. Results Mean activity was 134 MBq (3.62 mCi) for ULD-HE-SPECT (effective dose 1.15 mSv) and 278 MBq (7.50 mCi, 2.39 mSv) for SLD-A-SPECT. Overall IQ was superior for ULD-HE-SPECT (p<0.0001), with twice as many studies graded excellent quality. Extracardiac activity and overall perfusion assessment were similar. Between-method correlations were high for SRS (r=0.87), TPD (r=0.91), and EF (r=0.88). Conclusion ULD-HE-SPECT rest imaging correlates highly with SLD-A-SPECT. It has improved image quality, comparable extracardiac activity, and achieves radiation dose reduction to 1 mSv for a single injection. PMID:24982439

  7. Quantitative analysis of myocardial perfusion SPECT anatomically guided by co-registered 64-slice coronary CT angiography

    PubMed Central

    Slomka, Piotr J.; Cheng, Victor Y.; Dey, Damini; Woo, Jonghye; Ramesh, Amit; Kriekinge, Serge Van; Suzuki, Yasuzuki; Elad, Yaron; Karlsberg, Ronald; Berman, Daniel S.; Germano, Guido

    2012-01-01

    Aim Sequential testing by coronary computed tomography angiography (CTA) and myocardial perfusion SPECT (MPS) obtained on standalone scanners may be needed to diagnose coronary artery disease (CAD) in equivocal cases. We have developed an automated technique for MPS-CTA registration and demonstrate its utility for improved MPS quantification by guiding the co-registered physiological (MPS) with anatomical CTA information. Methods Automated registration of MPS left ventricular (LV) surfaces with CTA coronary trees was accomplished by iterative minimization of voxel differences between pre-segmented CTA volumes and “motion-frozen” MPS data. Studies of 35 sequential patients (26 males), mean age 67±12 years with 64-slice coronary CTA, MPS and with available results of the invasive coronary angiography performed within 3 months were retrospectively analyzed. 3D coronary vessels and CTA slices were extracted and fused with quantitative MPS results mapped on LV surfaces and MPS coronary regions. Automatically co-registered CTA images and extracted trees were used to correct the MPS contours and to adjust the standard vascular region definitions for MPS quantification. Results Automated co-registration of MPS and coronary CTA had the success rate of 96% as assessed visually; the average errors were 4.3±3.3 mm in translation and 1.5±2.6 deg in rotation on stress and 4.2±3.1 mm in translation and 1.7±3.2 deg in rotation on rest. MPS vascular region definition was adjusted in 17 studies and LV contours were adjusted in 11 studies using co-registered CTA images as a guide. CTA-guided MP analysis resulted in improved area under the receiver operator characteristics (ROC) curves for the detection of RCA and LCX lesions as compared to standard MPS analysis 0.84±0.08 vs. 0.70±0.11 for LCX (p = 0.03) and 0.92±0.05 vs. 0.75±0.09 (p=0.02) for RCA. Conclusions Software image co-registration of standalone coronary CTA and MPS obtained on separate scanners can be performed

  8. Regularized Image Reconstruction Algorithms for Dual-Isotope Myocardial Perfusion SPECT (MPS) Imaging Using a Cross-Tracer Prior

    PubMed Central

    He, Xin; Cheng, Lishui; Fessler, Jeffrey A.

    2011-01-01

    In simultaneous dual-isotope myocardial perfusion SPECT (MPS) imaging, data are simultaneously acquired to determine the distributions of two radioactive isotopes. The goal of this work was to develop penalized maximum likelihood (PML) algorithms for a novel cross-tracer prior that exploits the fact that the two images reconstructed from simultaneous dual-isotope MPS projection data are perfectly registered in space. We first formulated the simultaneous dual-isotope MPS reconstruction problem as a joint estimation problem. A cross-tracer prior that couples voxel values on both images was then proposed. We developed an iterative algorithm to reconstruct the MPS images that converges to the maximum a posteriori solution for this prior based on separable surrogate functions. To accelerate the convergence, we developed a fast algorithm for the cross-tracer prior based on the complete data OS-EM (COSEM) framework. The proposed algorithm was compared qualitatively and quantitatively to a single-tracer version of the prior that did not include the cross-tracer term. Quantitative evaluations included comparisons of mean and standard deviation images as well as assessment of image fidelity using the mean square error. We also evaluated the cross tracer prior using a three-class observer study with respect to the three-class MPS diagnostic task, i.e., classifying patients as having either no defect, reversible defect, or fixed defects. For this study, a comparison with conventional ordered subsets-expectation maximization (OS-EM) reconstruction with postfiltering was performed. The comparisons to the single-tracer prior demonstrated similar resolution for areas of the image with large intensity changes and reduced noise in uniform regions. The cross-tracer prior was also superior to the single-tracer version in terms of restoring image fidelity. Results of the three-class observer study showed that the proposed cross-tracer prior and the convergent algorithms improved the

  9. Combined anatomical and functional imaging using coronary CT angiography and myocardial perfusion SPECT in symptomatic adults with abnormal origin of a coronary artery.

    PubMed

    Uebleis, C; Groebner, M; von Ziegler, F; Becker, A; Rischpler, C; Tegtmeyer, R; Becker, C; Lehner, S; Haug, A R; Cumming, P; Bartenstein, P; Franz, W M; Hacker, M

    2012-10-01

    There has been a lack of standardized workup guidelines for patients with congenital abnormal origin of a coronary artery from the opposite sinus (ACAOS). We aimed to evaluate the use of cardiac hybrid imaging using multi-detector row CT (MDCT) for coronary CT angiography (Coronary CTA) and stress-rest myocardial perfusion SPECT (MPS) for comprehensive diagnosis of symptomatic adult patients with ACAOS. Seventeen symptomatic patients (12 men; 54 ± 13 years) presenting with ACAOS underwent coronary CTA and MPS. Imaging data were analyzed by conventional means, and with additional use of 3D image fusion to allocate stress induced perfusion defects (PD) to their supplying coronary arteries. An anomalous RCA arose from the left anterior sinus in eight patients, an abnormal origin from the right sinus was detected in nine patients (5 left coronary arteries, LCA and 4 LCx). Five of the 17 patients (29%) demonstrated a reversible PD in MPS. There was no correlation between the anatomical variants of ACAOS and the presence of myocardial ischemia. Image fusion enabled the allocation of reversible PD to the anomalous vessel in three patients (two cases in the RCA and the other in the LCA territory); PD in two patients were allocated to the territory of artery giving rise to the anomalies, rather than the anomalies themselves. In a small cohort of adult symptomatic patients with ACAOS anomaly there was no relation found between the specific anatomical variant and the appearance of stress induced myocardial ischemia using cardiac hybrid imaging. PMID:22147107

  10. The Development and Initial Evaluation of a Realistic Simulated SPECT Dataset with Simultaneous Respiratory and Cardiac Motion for Gated Myocardial Perfusion SPECT

    PubMed Central

    Lee, Taek-Soo; Tsui, Benjamin M. W.

    2015-01-01

    We developed a realistic simulation dataset for simultaneous respiratory and cardiac (R&C) gated SPECT/CT using the 4D NURBS-based Cardiac-Torso (NCAT) Phantom and Monte Carlo simulation methods, and evaluated it for a sample application study. The 4D NCAT phantom included realistic respiratory motion and beating heart motion based on respiratory gated CT and cardiac tagged MRI data of normal human subjects. To model the respiratory motion, a set of 24 separate 3D NCAT phantoms excluding the heart was generated over a respiratory cycle. The beating heart motion was modelled separately with 48 frames per cardiac cycle for each of the 24 respiratory phases. The resultant set of 24×48 3D NCAT phantoms provides a realistic model of a normal human subject at different phases of combined R&C motions. An almost noise-free SPECT projection dataset for each of the 1,152 3D NCAT phantoms was generated using Monte Carlo simulation techniques and the radioactivity uptake distribution of 99mTc sestamibi in different organs. By grouping and summing the separate projection datasets, separate or simultaneous R&C gated acquired data with different gating schemes could be simulated. In the initial evaluation, we combined the projection datasets into no gating, 6 respiratory-gates only, 8 cardiac-gates only, and combined 6 respiratory-gates & 8 cardiac-gates projection datasets. Each dataset was reconstructed using 3D OS-EM without and with attenuation correction using the averaged and respiratory-gated attenuation maps, and the resulting reconstructed images were compared. These results were used to demonstrate the effects of R&C motions and the reduction of image artifact due to R&C motions by gating and attenuation corrections. We concluded that the realistic 4D NCAT phantom and Monte Carlo simulated SPECT projection datasets with R&C motions are powerful tools in the study of the effects of R&C motions, as well as in the development of R&C gating schemes and motion correction

  11. The development and initial evaluation of a realistic simulated SPECT dataset with simultaneous respiratory and cardiac motion for gated myocardial perfusion SPECT

    NASA Astrophysics Data System (ADS)

    Lee, Taek-Soo; Tsui, Benjamin M. W.

    2015-02-01

    We developed a realistic simulation dataset for simultaneous respiratory and cardiac (R&C) gated SPECT/CT using the 4D NURBS-based Cardiac-Torso (NCAT) Phantom and Monte Carlo simulation methods, and evaluated it for a sample application study. The 4D NCAT phantom included realistic respiratory motion and beating heart motion based on respiratory gated CT and cardiac tagged MRI data of normal human subjects. To model the respiratory motion, a set of 24 separate 3D NCAT phantoms excluding the heart was generated over a respiratory cycle. The beating heart motion was modeled separately with 48 frames per cardiac cycle for each of the 24 respiratory phases. The resultant set of 24  ×  48 3D NCAT phantoms provides a realistic model of a normal human subject at different phases of combined R&C motions. An almost noise-free SPECT projection dataset for each of the 1152 3D NCAT phantoms was generated using Monte Carlo simulation techniques and the radioactivity uptake distribution of 99mTc sestamibi in different organs. By grouping and summing the separate projection datasets, separate or simultaneous R&C gated acquired data with different gating schemes could be simulated. In the initial evaluation, we combined the projection datasets into ungated, 6 respiratory-gates only, 8 cardiac-gates only, and combined 6 respiratory-gates & 8 cardiac-gates projection datasets. Each dataset was reconstructed using 3D OS-EM without and with attenuation correction using the averaged and respiratory-gated attenuation maps, and the resulting reconstructed images were compared. These results were used to demonstrate the effects of R&C motions and the reduction of image artifact due to R&C motions by gating and attenuation corrections. We concluded that the realistic 4D NCAT phantom and Monte Carlo simulated SPECT projection datasets with R&C motions are powerful tools in the study of the effects of R&C motions, as well as in the development of R&C gating schemes and motion

  12. The development and initial evaluation of a realistic simulated SPECT dataset with simultaneous respiratory and cardiac motion for gated myocardial perfusion SPECT.

    PubMed

    Lee, Taek-Soo; Tsui, Benjamin M W

    2015-02-21

    We developed a realistic simulation dataset for simultaneous respiratory and cardiac (R&C) gated SPECT/CT using the 4D NURBS-based Cardiac-Torso (NCAT) Phantom and Monte Carlo simulation methods, and evaluated it for a sample application study. The 4D NCAT phantom included realistic respiratory motion and beating heart motion based on respiratory gated CT and cardiac tagged MRI data of normal human subjects. To model the respiratory motion, a set of 24 separate 3D NCAT phantoms excluding the heart was generated over a respiratory cycle. The beating heart motion was modeled separately with 48 frames per cardiac cycle for each of the 24 respiratory phases. The resultant set of 24  ×  48 3D NCAT phantoms provides a realistic model of a normal human subject at different phases of combined R&C motions. An almost noise-free SPECT projection dataset for each of the 1152 3D NCAT phantoms was generated using Monte Carlo simulation techniques and the radioactivity uptake distribution of (99m)Tc sestamibi in different organs. By grouping and summing the separate projection datasets, separate or simultaneous R&C gated acquired data with different gating schemes could be simulated. In the initial evaluation, we combined the projection datasets into ungated, 6 respiratory-gates only, 8 cardiac-gates only, and combined 6 respiratory-gates & 8 cardiac-gates projection datasets. Each dataset was reconstructed using 3D OS-EM without and with attenuation correction using the averaged and respiratory-gated attenuation maps, and the resulting reconstructed images were compared. These results were used to demonstrate the effects of R&C motions and the reduction of image artifact due to R&C motions by gating and attenuation corrections. We concluded that the realistic 4D NCAT phantom and Monte Carlo simulated SPECT projection datasets with R&C motions are powerful tools in the study of the effects of R&C motions, as well as in the development of R&C gating schemes and motion

  13. No evidence of myocardial restoration following transplantation of mononuclear bone marrow cells in coronary bypass grafting surgery patients based upon cardiac SPECT and 18F-PET

    PubMed Central

    Tossios, Paschalis; Müller-Ehmsen, Jochen; Schmidt, Matthias; Scheid, Christof; Ünal, Nermin; Moka, Detlef; Schwinger, Robert HG; Mehlhorn, Uwe

    2006-01-01

    Background We tested the hypothesis, that intramyocardial injection of mononuclear bone marrow cells combined with coronary artery bypass grafting (CABG) surgery improves tissue viability or function in infarct regions with non-viable myocardium as assessed by nuclear imaging techniques. Methods Thus far, 7 patients (60 ± 10 [SD] years) undergoing elective CABG surgery after a myocardial infarction were included in this study. Prior to sternotomy, bone marrow was harvested by sternal puncture. Mononuclear bone marrow cells were isolated by gradient centrifugation and resuspended in 2 ml volume of Hank's buffered salt solution. At the end of CABG surgery 10 injections of 0.2 ml each were applied to the core area and borderzones of the infarct. Global and regional perfusion and viability were evaluated by ECG-gated 99mTc-tetrofosmin myocardial single-photon emission computed tomograph (SPECT) imaging and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in all study patients < 6 days before and 3 months after the intervention. Results Non-viable segments indicating transmural defects were identified in 5 patients. Two patients were found to have non-transmural defects before surgery. Concomitant surgical revascularisation and bone marrow cell injection was performed in all patients without major complications. The median total injected mononuclear cell number was 7.0 × 107 (range: 0.8–20.4). At 3 months 99mTc-tetrofosmin SPECT and 18F-FDG-PET scanning showed in 5 patients (transmural defect n = 4; non-transmural defect n = 1) no change in myocardial viability and in two patients (transmural defect n = 1, non-transmural defect n = 1) enhanced myocardial viability by 75%. Overall, global and regional LV ejection fraction was not significantly increased after surgery compared with the preoperative value. Conclusion In CABG surgery patients with non-viable segments the concurrent use of intramyocardial cell transfer did not show any clear improvement in

  14. Real-time cine and myocardial perfusion with treadmill exercise stress cardiovascular magnetic resonance in patients referred for stress SPECT

    PubMed Central

    2010-01-01

    Background To date, stress cardiovascular magnetic resonance (CMR) has relied on pharmacologic agents, and therefore lacked the physiologic information available only with exercise stress. Methods 43 patients age 25 to 81 years underwent a treadmill stress test incorporating both Tc99m SPECT and CMR. After rest Tc99m SPECT imaging, patients underwent resting cine CMR. Patients then underwent in-room exercise stress using a partially modified treadmill. 12-lead ECG monitoring was performed throughout. At peak stress, Tc99m was injected and patients rapidly returned to their prior position in the magnet for post-exercise cine and perfusion imaging. The patient table was pulled out of the magnet for recovery monitoring. The patient was sent back into the magnet for recovery cine and resting perfusion followed by delayed post-gadolinium imaging. Post-CMR, patients went to the adjacent SPECT lab to complete stress nuclear imaging. Each modality's images were reviewed blinded to the other's results. Results Patients completed on average 9.3 ± 2.4 min of the Bruce protocol. Stress cine CMR was completed in 68 ± 14 sec following termination of exercise, and stress perfusion CMR was completed in 88 ± 8 sec. Agreement between SPECT and CMR was moderate (κ = 0.58). Accuracy in eight patients who underwent coronary angiography was 7/8 for CMR and 5/8 for SPECT (p = 0.625). Follow-up at 6 months indicated freedom from cardiovascular events in 29/29 CMR-negative and 33/34 SPECT-negative patients. Conclusions Exercise stress CMR including wall motion and perfusion is feasible in patients with suspected ischemic heart disease. Larger clinical trials are warranted based on the promising results of this pilot study to allow comparative effectiveness studies of this stress imaging system vs. other stress imaging modalities. PMID:20624294

  15. Myocardial perfusion SPECT in a case of retropulmonary looping of left coronary artery in a baby after arterial switch surgery.

    PubMed

    Padma, Subramanyam; Sundaram, Palaniswamy Shanmuga

    2014-04-01

    Pediatric myocardial perfusion imaging (MPI) is not a routine investigation in an Indian setting due to under referrals and logistic problems. However, MPI is a frequently performed and established modality of investigation in adults for the identification of myocardial ischemia and viability. We report myocardial perfusion scintigraphy in a case of retropulmonary looping of left coronary artery in a baby after arterial switch surgery. Adenosine stress MPI revealed a large infarct involving anterior segment with moderate reversible ischemia of the lateral left ventricular segment. Coronary angiogram later confirmed left main coronary artery ostial occlusion with retrograde collateral supply from dilated right coronary artery. PMID:24761067

  16. Task-based evaluation of a 4D MAP-RBI-EM image reconstruction method for gated myocardial perfusion SPECT using a human observer study

    NASA Astrophysics Data System (ADS)

    Lee, Taek-Soo; Higuchi, Takahiro; Lautamäki, Riikka; Bengel, Frank M.; Tsui, Benjamin M. W.

    2015-09-01

    We evaluated the performance of a new 4D image reconstruction method for improved 4D gated myocardial perfusion (MP) SPECT using a task-based human observer study. We used a realistic 4D NURBS-based Cardiac-Torso (NCAT) phantom that models cardiac beating motion. Half of the population was normal; the other half had a regional hypokinetic wall motion abnormality. Noise-free and noisy projection data with 16 gates/cardiac cycle were generated using an analytical projector that included the effects of attenuation, collimator-detector response, and scatter (ADS), and were reconstructed using the 3D FBP without and 3D OS-EM with ADS corrections followed by different cut-off frequencies of a 4D linear post-filter. A 4D iterative maximum a posteriori rescaled-block (MAP-RBI)-EM image reconstruction method with ADS corrections was also used to reconstruct the projection data using various values of the weighting factor for its prior. The trade-offs between bias and noise were represented by the normalized mean squared error (NMSE) and averaged normalized standard deviation (NSDav), respectively. They were used to select reasonable ranges of the reconstructed images for use in a human observer study. The observers were trained with the simulated cine images and were instructed to rate their confidence on the absence or presence of a motion defect on a continuous scale. We then applied receiver operating characteristic (ROC) analysis and used the area under the ROC curve (AUC) index. The results showed that significant differences in detection performance among the different NMSE-NSDav combinations were found and the optimal trade-off from optimized reconstruction parameters corresponded to a maximum AUC value. The 4D MAP-RBI-EM with ADS correction, which had the best trade-off among the tested reconstruction methods, also had the highest AUC value, resulting in significantly better human observer detection performance when detecting regional myocardial wall motion

  17. Task-Based Evaluation of a 4D MAP-RBI-EM Image Reconstruction Method for Gated Myocardial Perfusion SPECT using a Human Observer Study

    PubMed Central

    Lee, Taek-Soo; Higuchi, Takahiro; Lautamäki, Riikka; Bengel, Frank M.; Tsui, Benjamin M. W.

    2015-01-01

    We evaluated the performance of a new 4D image reconstruction method for improved 4D gated myocardial perfusion (MP) SPECT using a task-based human observer study. We used a realistic 4D NURBS-based Cardiac-Torso (NCAT) phantom that models cardiac beating motion. Half of the population was normal; the other half had a regional hypokinetic wall motion abnormality. Noise-free and noisy projection data with 16 gates/cardiac cycle were generated using an analytical projector that included the effects of attenuation, collimator-detector response, and scatter (ADS), and were reconstructed using the 3D FBP without and 3D OS-EM with ADS corrections followed by different cut-off frequencies of a 4D linear post-filter. A 4D iterative maximum a posteriori rescaled-block (MAP-RBI)-EM image reconstruction method with ADS corrections was also used to reconstruct the projection data using various values of the weighting factor for its prior. The trade-offs between bias and noise were represented by the normalized mean squared error (NMSE) and averaged normalized standard deviation (NSDav), respectively. They were used to select reasonable ranges of the reconstructed images for use in a human observer study. The observers were trained with the simulated cine images and were instructed to rate their confidence on the absence or presence of a motion defect on a continuous scale. We then applied receiver operating characteristic (ROC) analysis and used the area under the ROC curve (AUC) index. The results showed that significant differences in detection performance among the different NMSE-NSDav combinations were found and the optimal trade-off from optimized reconstruction parameters corresponded to a maximum AUC value. The 4D MAP-RBI-EM with ADS correction, which had the best trade-off among the tested reconstruction methods, also had the highest AUC value, resulting in significantly better human observer detection performance when detecting regional myocardial wall motion

  18. Task-based evaluation of a 4D MAP-RBI-EM image reconstruction method for gated myocardial perfusion SPECT using a human observer study.

    PubMed

    Lee, Taek-Soo; Higuchi, Takahiro; Lautamäki, Riikka; Bengel, Frank M; Tsui, Benjamin M W

    2015-09-01

    We evaluated the performance of a new 4D image reconstruction method for improved 4D gated myocardial perfusion (MP) SPECT using a task-based human observer study. We used a realistic 4D NURBS-based Cardiac-Torso (NCAT) phantom that models cardiac beating motion. Half of the population was normal; the other half had a regional hypokinetic wall motion abnormality. Noise-free and noisy projection data with 16 gates/cardiac cycle were generated using an analytical projector that included the effects of attenuation, collimator-detector response, and scatter (ADS), and were reconstructed using the 3D FBP without and 3D OS-EM with ADS corrections followed by different cut-off frequencies of a 4D linear post-filter. A 4D iterative maximum a posteriori rescaled-block (MAP-RBI)-EM image reconstruction method with ADS corrections was also used to reconstruct the projection data using various values of the weighting factor for its prior. The trade-offs between bias and noise were represented by the normalized mean squared error (NMSE) and averaged normalized standard deviation (NSDav), respectively. They were used to select reasonable ranges of the reconstructed images for use in a human observer study. The observers were trained with the simulated cine images and were instructed to rate their confidence on the absence or presence of a motion defect on a continuous scale. We then applied receiver operating characteristic (ROC) analysis and used the area under the ROC curve (AUC) index. The results showed that significant differences in detection performance among the different NMSE-NSDav combinations were found and the optimal trade-off from optimized reconstruction parameters corresponded to a maximum AUC value. The 4D MAP-RBI-EM with ADS correction, which had the best trade-off among the tested reconstruction methods, also had the highest AUC value, resulting in significantly better human observer detection performance when detecting regional myocardial wall motion

  19. Ischemic "memory image" in acute myocardial infarction of 123I-BMIPP after reperfusion therapy: a comparison with 99mTc-pyrophosphate and 201Tl dual-isotope SPECT.

    PubMed

    Mochizuki, Teruhito; Murase, Kenya; Higashino, Hiroshi; Miyagawa, Masao; Sugawara, Yoshifumi; Kikuchi, Takanori; Ikezoe, Junpei

    2002-12-01

    Ischemic "memory image" is a phenomenon of 123I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) in which an area at risk of acute myocardial infarction (AMI), could be detected as a defect in a couple of weeks even after successful reperfusion therapy. The purpose of this study was to clarify the incidence of the ischemic "memory image" of 123I-BMIPP in patients with AMI by comparing 99mTc-PYP and 201Tl dual-isotope SPECT. Materials consisted of 14 patients with successfully reperfused AMI and 20 patients with old myocardial infarction (OMI). All AMI patients underwent PYP/Tl dual-isotope SPECT within 1 week after the onset of AMI, and BMIPP SPECT was performed within 1 week after the PYP/Tl dual-isotope SPECT. The extent and severity of the defect of BMIPP and Tl were visually scored into four grades: 0 = no defect to 3 = large or severe defect. These scores were compared. PYP positive AMI lesions were concordant with BMIPP defects (13/14). In AMI, both the extent and severity scores of BMIPP were higher than 201Tl (p < 0.001). Differences (BMIPP - Tl) of extent and severity scores were greater in AMI than in OMI (p < 0.001). In conclusion, the ischemic "memory image" obtained by means of the BMIPP is a common phenomenon (13/14) in AMI, and helpful in evaluating the area at risk. PMID:12593422

  20. Effects of CT-based attenuation correction of rat microSPECT images on relative myocardial perfusion and quantitative tracer uptake

    SciTech Connect

    Strydhorst, Jared H. Ruddy, Terrence D.; Wells, R. Glenn

    2015-04-15

    Purpose: Our goal in this work was to investigate the impact of CT-based attenuation correction on measurements of rat myocardial perfusion with {sup 99m}Tc and {sup 201}Tl single photon emission computed tomography (SPECT). Methods: Eight male Sprague-Dawley rats were injected with {sup 99m}Tc-tetrofosmin and scanned in a small animal pinhole SPECT/CT scanner. Scans were repeated weekly over a period of 5 weeks. Eight additional rats were injected with {sup 201}Tl and also scanned following a similar protocol. The images were reconstructed with and without attenuation correction, and the relative perfusion was analyzed with the commercial cardiac analysis software. The absolute uptake of {sup 99m}Tc in the heart was also quantified with and without attenuation correction. Results: For {sup 99m}Tc imaging, relative segmental perfusion changed by up to +2.1%/−1.8% as a result of attenuation correction. Relative changes of +3.6%/−1.0% were observed for the {sup 201}Tl images. Interscan and inter-rat reproducibilities of relative segmental perfusion were 2.7% and 3.9%, respectively, for the uncorrected {sup 99m}Tc scans, and 3.6% and 4.3%, respectively, for the {sup 201}Tl scans, and were not significantly affected by attenuation correction for either tracer. Attenuation correction also significantly increased the measured absolute uptake of tetrofosmin and significantly altered the relationship between the rat weight and tracer uptake. Conclusions: Our results show that attenuation correction has a small but statistically significant impact on the relative perfusion measurements in some segments of the heart and does not adversely affect reproducibility. Attenuation correction had a small but statistically significant impact on measured absolute tracer uptake.

  1. [The clinical significance of reverse redistribution of Tl-201 SPECT at rest in the 1st month after the onset of acute myocardial infarction].

    PubMed

    Umamoto, I; Sugihara, H; Harada, Y; Sawada, T; Matsumuro, A; Matsubara, K; Shiga, K; Nakagawa, T; Oonishi, K; Nakamura, T

    1991-07-01

    The pattern of Thallium-201 reverse redistribution (r-RD) at rest has been reported in some patients with acute myocardial infarction (AMI) in the acute phase. But there is no report of this pattern in the later phase. To investigate the significance of Thallium-201 reverse redistribution in the subacute phase, 37 patients with AMI underwent Thallium-201 SPECT at rest a month after the onset. The patients were classified into three groups visually and 19 of 37 patients (51%) showed the persistent defect pattern (Group PD), and the remaining 18 patients (49%) had the reverse redistribution pattern (Group r-RD). None of them had the redistribution pattern. Coronary reflow was earlier and the incidence of the scintigraphic overlap on Dual SPECT image of 99mTc-PYP/201TlCl in the acute phase was more frequent in Group r-RD than in Group PD. A decrease in thallium defect size of patients with r-RD from the acute phase to one month after the onset represented improvement more significantly than that with PD. Initial %Tl uptake of the infarcted region of Group r-RD was greater than that of Group PD. The degree of stenosis of the infarct-related coronary artery in Group r-RD was less severe than that in Group PD. And corresponding regional wall motion of Group r-RD was less impaired. The Thallium-201 washout in the infarcted region with r-RD was significantly faster than that in the normal region. It is concluded that the r-RD pattern at rest in the 1st month after the onset of AMI may be a sign of viable myocardium. PMID:1833574

  2. Reproducibility of area at risk assessment in acute myocardial infarction by T1- and T2-mapping sequences in cardiac magnetic resonance imaging in comparison to Tc99m-sestamibi SPECT.

    PubMed

    Langhans, Birgit; Nadjiri, Jonathan; Jähnichen, Christin; Kastrati, Adnan; Martinoff, Stefan; Hadamitzky, Martin

    2014-10-01

    Area at risk (AAR) is an important parameter for the assessment of the salvage area after revascularization in acute myocardial infarction (AMI). By combining AAR assessment by T2-weighted imaging and scar quantification by late gadolinium enhancement imaging cardiovascular magnetic resonance (CMR) offers a promising alternative to the "classical" modality of Tc99m-sestamibi single photon emission tomography (SPECT). Current T2 weighted sequences for edema imaging in CMR are limited by low contrast to noise ratios and motion artifacts. During the last years novel CMR imaging techniques for quantification of acute myocardial injury, particularly the T1-mapping and T2-mapping, have attracted rising attention. But no direct comparison between the different sequences in the setting of AMI or a validation against SPECT has been reported so far. We analyzed 14 patients undergoing primary coronary revascularization in AMI in whom both a pre-intervention Tc99m-sestamibi-SPECT and CMR imaging at a median of 3.4 (interquartile range 3.3-3.6) days after the acute event were performed. Size of AAR was measured by three different non-contrast CMR techniques on corresponding short axis slices: T2-weighted, fat-suppressed turbospin echo sequence (TSE), T2-mapping from T2-prepared balanced steady state free precession sequences (T2-MAP) and T1-mapping from modified look locker inversion recovery (MOLLI) sequences. For each CMR sequence, the AAR was quantified by appropriate methods (absolute values for mapping sequences, comparison with remote myocardium for other sequences) and correlated with Tc99m-sestamibi-SPECT. All measurements were performed on a 1.5 Tesla scanner. The size of the AAR assessed by CMR was 28.7 ± 20.9 % of left ventricular myocardial volume (%LV) for TSE, 45.8 ± 16.6 %LV for T2-MAP, and 40.1 ± 14.4 %LV for MOLLI. AAR assessed by SPECT measured 41.6 ± 20.7 %LV. Correlation analysis revealed best correlation with SPECT for T2-MAP at a T2-threshold of 60 ms

  3. [Interesting PYP, 201Tl, MIBG, AM and BMIPP myocardial SPECT images in a patient under successful reperfusion therapy].

    PubMed

    Tanaka, T; Aizawa, T; Katou, K; Ogasawara, K; Kirigaya, H; Okamoto, K; Hosoi, H; Oota, A

    1992-06-01

    Various types of radiopharmacons such as 201Tl, 99mTc-pyrophosphate(PYP), 123I-metaiodobenzyl-guanidine(MIBG), 111In-antimyosin Fab (AM) and 123I-beta-methyl iodophenyl pentadecanoic acid (BMIPP) were applied to a patient under successful reperfusion therapy. In the patient, elevated serum enzyme activity region in the subacute phase. Ten months after the ischemic event, AM uptake was noted at the region which maintained contractility. Two years after the ischemic event, depressed BMIPP uptake and delayed washout were noted at the apical region and the basal anteroseptal region. From these findings, the following conclusions were reached. Depressed 201Tl uptake was noted in the salvaged jeopardized myocardium. The lesions noted in the MIBG images showed depressed myocardial norepenephrine activity. This suggested that depressed sympathetic nervous function caused by severe ischemia persisted long after both myocardial perfusion and myocardial contractility had been restored. From abnormal AM uptake in the contractile myocardium myocardial cell damage, which permitted AM uptake, was persistent ten months after the ischemic event. Depressed BMIPP uptake and delayed washout suggested that abnormal fatty acid metabolism caused by severe ischemia was persistent. Severe ischemia caused various types of pathological states in the myocardium and radioisotope image was useful for studying these states. PMID:1535723

  4. Importance of 123I-ioflupane SPECT and Myocardial MIBG Scintigraphy to Determine the Candidate of Deep Brain Stimulation for Parkinson’s Disease

    PubMed Central

    ASAHI, Takashi; KASHIWAZAKI, Daina; YONEYAMA, Tatsuya; NOGUCHI, Kyo; KURODA, Satoshi

    2016-01-01

    123I-ioflupane SPECT (DaTscan) is an examination that detects presynaptic dopamine neuronal dysfunction, and has been used as a diagnostic tool to identify degenerative parkinsonism. Additionally, myocardial 123I-metaiodobenzyl guanidine (MIBG) scintigraphy measures the concentration of cardiac sympathetic nerve fibers and is used to diagnose Parkinson’s disease (PD). These exams are used as adjuncts in the diagnosis of parkinsonism, however, the relationship of these two examinations are not well-known. We investigated the relationship of these two scanning results specifically for determining the use of deep brain stimulation therapy (DBS). Subjects were Japanese patients with suspected striatonigral degeneration, including PD; DaTscans and myocardial MIBG scintigraphy were performed. The mean values of the left-right specific binding ratios (SBRs) from the DaTscan, and the early/delayed heart-to-mediastinum ratios (HMRs) from the MIBG scintigraphy were calculated. Using simple linear regression analysis, we compared the SBR and early/delayed HMR values. Twenty-four patients were enrolled in this study. Twenty-one patients were positive via the DaTscan, and the MIBG scintigraphy results showed 14 patients were positive. SBR and both early and delayed HMR were positively correlated in cases of PD, but negative in non-PD cases. A mean SBR value less than 3.0 and a delayed HMR value less than 1.7 indicated a Hoehn-Yahr stage 3 or 4 for PD, which is commonly regarded as a level appropriate for initiating DBS therapy. Our results indicate that performing both DaTscan and MIBG scintigraphy is useful for the evaluation of surgical intervention in PD. PMID:26794041

  5. Diagnosis of myocardial involvement in patients with systemic myopathies with 15-(p-(I-123)iodophenyl) pentadecanoic acid (IPPA) SPECT

    SciTech Connect

    Kropp, J.; Briele, B.; Smekal, A.V.; Hotze, A.L.; Biersack, H.J.; Koehler, U.; Zierz, St. ); Knapp, F.F. )

    1992-01-01

    Involvement of the myocardium in non-infectious myopathies presents in most cases as systolic dysfunction or a disturbed cardiac rhythm. We are interested in exploring how often cardiac involvement can be evaluated with various diagnostic techniques in patients with proven myopathy. We investigated 41 patients with myopathies of various etiology, including mitochondrial and congenital myopathies, Curshmann-Steinert disease, muscular dystrophy, and others. Myopathy was proven by muscular biopsy usually from the bicep. Fatty acid imaging was performed with 15-(p-(I-123)iodophenyl)pentadecanoic acid (IP-PA) and sequential SPECT-scintigraphy with a 180 deg. rotation starting at the 45 deg. RAO position. 190 MBq were injected at the maximal stage of a submaximal exercise. Filtered backprojection and reorientation of the slices were achieved by standard techniques. The quantitative comparison of the oblique slices (bulls-eye technique) of the SPECT-studies revealed turnover-rates as a qualitative measure of {beta}-oxidation. Serum levels of lactate (L), pyruvate (P), glucose (G) and triglycerides (TG) were measured at rest and stress. Ventricular function was investigated by radionuclide ventriculography (MUGA) at rest and under stress with Tc-99m labeled red blood cells. In addition, ECG, 24 hour-ECG, and echocardiography were also performed with standard techniques.

  6. Diagnosis of myocardial involvement in patients with systemic myopathies with 15-(p-[I-123]iodophenyl) pentadecanoic acid (IPPA) SPECT

    SciTech Connect

    Kropp, J.; Briele, B.; Smekal, A.V.; Hotze, A.L.; Biersack, H.J.; Koehler, U.; Zierz, St.; Knapp, F.F.

    1992-03-01

    Involvement of the myocardium in non-infectious myopathies presents in most cases as systolic dysfunction or a disturbed cardiac rhythm. We are interested in exploring how often cardiac involvement can be evaluated with various diagnostic techniques in patients with proven myopathy. We investigated 41 patients with myopathies of various etiology, including mitochondrial and congenital myopathies, Curshmann-Steinert disease, muscular dystrophy, and others. Myopathy was proven by muscular biopsy usually from the bicep. Fatty acid imaging was performed with 15-(p-[I-123]iodophenyl)pentadecanoic acid (IP-PA) and sequential SPECT-scintigraphy with a 180 deg. rotation starting at the 45 deg. RAO position. 190 MBq were injected at the maximal stage of a submaximal exercise. Filtered backprojection and reorientation of the slices were achieved by standard techniques. The quantitative comparison of the oblique slices (bulls-eye technique) of the SPECT-studies revealed turnover-rates as a qualitative measure of {beta}-oxidation. Serum levels of lactate (L), pyruvate (P), glucose (G) and triglycerides (TG) were measured at rest and stress. Ventricular function was investigated by radionuclide ventriculography (MUGA) at rest and under stress with Tc-99m labeled red blood cells. In addition, ECG, 24 hour-ECG, and echocardiography were also performed with standard techniques.

  7. Automatic detection of coronary artery disease in myocardial perfusion SPECT using image registration and voxel to voxel statistical comparisons.

    PubMed

    Peace, R A; Staff, R T; Gemmell, H G; McKiddie, F I; Metcalfe, M J

    2002-08-01

    The purpose of this study was to compare the performance of automatic detection of coronary artery disease (CAD) with that of expert observers. A male and female normal image template was constructed from normal stress technetium-99m single photon emission computed tomography (SPECT) studies. Mean and standard deviation images for each sex were created by registering normal studies to a standard shape and position. The test group consisted of 104 patients who had been routinely referred for SPECT and angiography. The gold standard for CAD was defined by angiography. The test group studies were registered to the respective templates and the Z-score was calculated for each voxel. Voxels with a Z-score greater than 5 indicated the presence of CAD. The performance of this method and that of three observers were compared by continuous receiver operating characteristic (CROC) analysis. The overall sensitivity and specificity for automatic detection were 73% and 92%, respectively. The area (Az) under the CROC curve (+/-1 SE) for automatic detection of CAD was 0.88+/-0.06. There was no statistically significant difference between the performances of the three observers in terms of Az and that of automatic detection (P> or =0.25, univariate Z-score test). The use of this automated statistical mapping approach shows a performance comparable with experienced observers, but avoids inter-observer and intra-observer variability. PMID:12124485

  8. [Interesting PYP, Tl-201, MIBG and AM myocardial SPECT images in a patient under successful reperfusion therapy].

    PubMed

    Tanaka, T; Aizawa, T; Kato, K; Ogasawara, K; Kirigaya, H; Okamoto, K

    1991-09-01

    Various types of radiopharmacons such as Tl-201, Tc-99m pyrophosphate (PYP), I-123 Metaiodobenzylguanidine (MIBG) and In-111 antimyosin Fab (AM), were applied to a patients under successful reperfusion therapy. In the patient QS waves in precordial leads and elevated serum enzyme activity was noted, however well anterior wall movement was maintained in chronic phase. At 4th hospital day PYP uptake was noted at apical region and basal anteroseptal region. Most portion of PYP uptake was overlapped by Tl-201 uptake. Depressed Tl-201 uptake in subacute phase improved. In chronic phase depressed MIBG uptake was noted at the region corresponding to the abnormal region in acute phase. Then months after the ischemic event AM uptake was noted at the region which maintained contractility. From these findings it was concluded as followings. Salvaged jeopardized myocardium remained ischemia in subacute phase. The lesions noted in the MIBG images showed depressed myocardial norepinephrine activity. This suggested that sympathetic nervous function was damaged by severe ischemia and the depressed sympathetic nervous function persisted long after myocardial perfusion had been restored. From abnormal AM uptake ten months after ischemic event it was suspected that myocardial cell membrane damage caused by severe ischemia might be persistent at the region which maintained contractility. Radioisotope image was useful to study pathological myocardium due to ischemic event. PMID:1837571

  9. Assessment of cardiac function using myocardial perfusion imaging technique on SPECT with 99mTc sestamibi

    NASA Astrophysics Data System (ADS)

    Gani, M. R. A.; Nazir, F.; Pawiro, S. A.; Soejoko, D. S.

    2016-03-01

    Suspicion on coronary heart disease can be confirmed by observing the function of left ventricle cardiac muscle with Myocardial Perfusion Imaging techniques. The function perfusion itself is indicated by the uptake of radiopharmaceutical tracer. The 31 patients were studied undergoing the MPI examination on Gatot Soebroto Hospital using 99mTc-sestamibi radiopharmaceutical with stress and rest conditions. Stress was stimulated by physical exercise or pharmacological agent. After two hours, the patient did rest condition on the same day. The difference of uptake percentage between stress and rest conditions will be used to determine the malfunction of perfusion due to ischemic or infarct. Degradation of cardiac function was determined based on the image-based assessment of five segments of left ventricle cardiac. As a result, 8 (25.8%) patients had normal myocardial perfusion and 11 (35.5%) patients suspected for having partial ischemia. Total ischemia occurred to 8 (25.8%) patients with reversible and irreversible ischemia and the remaining 4 (12.9%) patients for partial infarct with characteristic the percentage of perfusion ≤50%. It is concluded that MPI technique of image-based assessment on uptake percentage difference between stress and rest conditions can be employed to predict abnormal perfusion as complementary information to diagnose the cardiac function.

  10. Left ventricular dyssynchrony assessed by two three-dimensional imaging modalities: phase analysis of gated myocardial perfusion SPECT and tri-plane tissue Doppler imaging

    PubMed Central

    Ajmone Marsan, Nina; Henneman, Maureen M.; Chen, Ji; Ypenburg, Claudia; Dibbets, Petra; Ghio, Stefano; Bleeker, Gabe B.; Stokkel, Marcel P.; van der Wall, Ernst E.; Tavazzi, Luigi; Garcia, Ernest V.

    2007-01-01

    Purpose To compare left ventricular (LV) dyssynchrony assessment by phase analysis from gated myocardial perfusion SPECT (GMPS) with LV dyssynchrony assessment by tri-plane tissue Doppler imaging (TDI). Baseline LV dyssynchrony assessed with standard deviation (SD) of time-to-peak systolic velocity of 12 LV segments (Ts-SD) with TDI has proven to be a powerful predictor of response to CRT. Information on LV dyssynchrony can also be provided by GMPS with phase analysis of regional LV maximal count changes throughout the cardiac cycle. Methods Forty heart failure patients, referred for evaluation of potential eligibility for CRT, underwent both 3D echocardiography, with tri-plane TDI, and resting GMPS. From tri-plane TDI, Ts-SD was used as a validated parameter of LV dyssynchrony and compared with different indices (histogram bandwidth, phase SD, histogram skewness and kurtosis) derived from phase analysis of GMPS. Results Histogram bandwidth and phase SD showed good correlation with Ts-SD (r=0.77 and r=0.74, p<0.0001, respectively). Patients with substantial LV dyssynchrony assessed with tri-plane TDI (Ts-SD ≥33 ms) had also significantly higher values of histogram bandwidth and phase SD. Conclusions The results of this study support the use of phase analysis by GMPS to evaluate LV dyssynchrony. Histogram bandwidth and phase SD showed the best correlation with Ts-SD assessed with tri-plane TDI and appeared the most optimal variables for assessment of LV dyssynchrony with GMPS. PMID:17874098

  11. Specificity and sensitivity of SPECT myocardial perfusion studies at the Nuclear Medicine Department of the Limassol General Hospital in Cyprus

    NASA Astrophysics Data System (ADS)

    Koumna, S.; Yiannakkaras, Ch; Avraamides, P.; Demetriadou, O.

    2011-09-01

    The aim is to determine the sensitivity and specificity of Myocardial Perfusion Imaging (MPI) performed at the Nuclear Medicine Department of the Limassol General Hospital in Cyprus. Through a retrospective analysis, patient results obtained by MPI were compared to results obtained by Invasive Angiography. We analyzed data from 96 patients that underwent both MPI and Angiography during the years 2009-2010, with a maximum time interval of ± 9 months between the two types of medical exams. For 51 patients, the indication was the detection of CAD. For 45 patients, the indication was to assess viability and/or ischemia after MI, PCI or CABG. Out of 84 patients with CAD confirmed by angiography, 80 patients resulted in abnormal MPI (sensitivity of 95% and positive predictive value of 98%). Out of 12 patients with normal coronaries, 10 patients resulted in normal MPI (specificity of 83% and negative predictive value of 71%).In conclusion, for the patients with abnormal MPI and confirmed CAD, MPI was a useful aid for further therapy management.

  12. The Benefits of Prone SPECT Myocardial Perfusion Imaging in Reducing Both Artifact Defects and Patient Radiation Exposure

    PubMed Central

    Stathaki, Maria; Koukouraki, Sophia; Papadaki, Emmanouela; Tsaroucha, Angeliki; Karkavitsas, Nikolaos

    2015-01-01

    Background Prone imaging has been demonstrated to minimize diaphragmatic and breast tissue attenuation. Objectives To determine the role of prone imaging on the reduction of unnecessary rest perfusion studies and coronary angiographies performed, thus decreasing investigation time and radiation exposure. Methods We examined 139 patients, 120 with an inferior wall and 19 with an anterior wall perfusion defect that might represented attenuation artifact. Post-stress images were acquired in both the supine and prone position. Coronary angiography was used as the “gold standard” for evaluating coronary artery patency. The study was terminated and rest imaging was obviated in the presence of complete improvement of the defect in the prone position. Quantitative interpretation was performed. Results were compared with clinical data and coronary angiographic findings. Results Prone acquisition correctly revealed defect improvement in 89 patients (89/120) with inferior wall and 12 patients (12/19) with anterior wall attenuation artifact. Quantitative analysis demonstrated statistically significant difference in the mean summed stress scores (SSS) of supine and mean SSS of prone studies in patients with disappearing inferior wall defect in the prone position and patent right coronary artery (true negative results). The mean difference between SSS in supine and in prone position was higher with disappearing than with remaining defects. Conclusion Technetium-99m (Tc-99m) tetrofosmin myocardial perfusion imaging with the patient in the prone position overcomes soft tissue attenuation; moreover it provides an inexpensive, accurate approach to limit the number of unnecessary rest perfusion studies and coronary angiographies performed. PMID:26559981

  13. Collimator optimization and collimator-detector response compensation in myocardial perfusion SPECT using the ideal observer with and without model mismatch and an anthropomorphic model observer

    NASA Astrophysics Data System (ADS)

    Ghaly, Michael; Links, Jonathan M.; Frey, Eric C.

    2016-03-01

    The collimator is the primary factor that determines the spatial resolution and noise tradeoff in myocardial perfusion SPECT images. In this paper, the goal was to find the collimator that optimizes the image quality in terms of a perfusion defect detection task. Since the optimal collimator could depend on the level of approximation of the collimator-detector response (CDR) compensation modeled in reconstruction, we performed this optimization for the cases of modeling the full CDR (including geometric, septal penetration and septal scatter responses), the geometric CDR, or no model of the CDR. We evaluated the performance on the detection task using three model observers. Two observers operated on data in the projection domain: the Ideal Observer (IO) and IO with Model-Mismatch (IO-MM). The third observer was an anthropomorphic Channelized Hotelling Observer (CHO), which operated on reconstructed images. The projection-domain observers have the advantage that they are computationally less intensive. The IO has perfect knowledge of the image formation process, i.e. it has a perfect model of the CDR. The IO-MM takes into account the mismatch between the true (complete and accurate) model and an approximate model, e.g. one that might be used in reconstruction. We evaluated the utility of these projection domain observers in optimizing instrumentation parameters. We investigated a family of 8 parallel-hole collimators, spanning a wide range of resolution and sensitivity tradeoffs, using a population of simulated projection (for the IO and IO-MM) and reconstructed (for the CHO) images that included background variability. We simulated anterolateral and inferior perfusion defects with variable extents and severities. The area under the ROC curve was estimated from the IO, IO-MM, and CHO test statistics and served as the figure-of-merit. The optimal collimator for the IO had a resolution of 9-11 mm FWHM at 10 cm, which is poorer resolution than typical collimators

  14. Collimator optimization and collimator-detector response compensation in myocardial perfusion SPECT using the ideal observer with and without model mismatch and an anthropomorphic model observer.

    PubMed

    Ghaly, Michael; Links, Jonathan M; Frey, Eric C

    2016-03-01

    The collimator is the primary factor that determines the spatial resolution and noise tradeoff in myocardial perfusion SPECT images. In this paper, the goal was to find the collimator that optimizes the image quality in terms of a perfusion defect detection task. Since the optimal collimator could depend on the level of approximation of the collimator-detector response (CDR) compensation modeled in reconstruction, we performed this optimization for the cases of modeling the full CDR (including geometric, septal penetration and septal scatter responses), the geometric CDR, or no model of the CDR. We evaluated the performance on the detection task using three model observers. Two observers operated on data in the projection domain: the Ideal Observer (IO) and IO with Model-Mismatch (IO-MM). The third observer was an anthropomorphic Channelized Hotelling Observer (CHO), which operated on reconstructed images. The projection-domain observers have the advantage that they are computationally less intensive. The IO has perfect knowledge of the image formation process, i.e. it has a perfect model of the CDR. The IO-MM takes into account the mismatch between the true (complete and accurate) model and an approximate model, e.g. one that might be used in reconstruction. We evaluated the utility of these projection domain observers in optimizing instrumentation parameters. We investigated a family of 8 parallel-hole collimators, spanning a wide range of resolution and sensitivity tradeoffs, using a population of simulated projection (for the IO and IO-MM) and reconstructed (for the CHO) images that included background variability. We simulated anterolateral and inferior perfusion defects with variable extents and severities. The area under the ROC curve was estimated from the IO, IO-MM, and CHO test statistics and served as the figure-of-merit. The optimal collimator for the IO had a resolution of 9-11 mm FWHM at 10 cm, which is poorer resolution than typical collimators

  15. An Investigation Of the Trade-Off Between Count Level and Image Quality in Myocardial Perfusion SPECT using Simulated Images: the Effects of Statistical Noise and Object Variability on Defect Detectability

    PubMed Central

    He, Xin; Links, Jonathan M.; Frey, Eric C.

    2010-01-01

    Quantum noise as well as anatomic and uptake variability in patient populations limits observer performance on a defect detection task in myocardial perfusion SPECT (MPS). The goal of this study was to investigate the relative importance of these two effects by varying acquisition time, which determines the count level, and assessing the change in performance on a myocardial perfusion (MP) defect detection task using both mathematical and human observers. We generated 10 sets of projections of a simulated patient population with count levels ranging from 1/128 to around 15 times a typical clinical count level to simulate different levels of quantum noise. For the simulated population we modeled variations in patient, heart and defect size, heart orientation and shape, defect location, organ uptake ratio, etc. The projection data were reconstructed using the OS-EM algorithm with no compensation or with attenuation, detector response and scatter compensation (ADS). The images were then post-filtered and reoriented to generate short axis slices. A channelized Hotelling observer (CHO) was applied to the short-axis images, and the area under the receiver operating characteristics (ROC) curve (AUC) was computed. For each noise level and reconstruction method, we optimized the number of iterations and cutoff frequencies of the Butterworth filter to maximize the AUC. Using the images obtained with the optimal iteration and cutoff frequency and ADS compensation, we performed human observer studies for 4 count levels to validate the CHO results. Both CHO and human observer studies demonstrated that observer performance was dependent on the relative magnitude of the quantum noise and the patient variation. When the count level was high, the patient variation dominated, and the AUC increased very slowly with changes in the count level for the same level of anatomic variability. When the count level was low, however, quantum noise dominated, and changes in count level resulted

  16. An investigation of the trade-off between the count level and image quality in myocardial perfusion SPECT using simulated images: the effects of statistical noise and object variability on defect detectability

    NASA Astrophysics Data System (ADS)

    He, Xin; Links, Jonathan M.; Frey, Eric C.

    2010-09-01

    Quantum noise as well as anatomic and uptake variability in patient populations limits observer performance on a defect detection task in myocardial perfusion SPECT (MPS). The goal of this study was to investigate the relative importance of these two effects by varying acquisition time, which determines the count level, and assessing the change in performance on a myocardial perfusion (MP) defect detection task using both mathematical and human observers. We generated ten sets of projections of a simulated patient population with count levels ranging from 1/128 to around 15 times a typical clinical count level to simulate different levels of quantum noise. For the simulated population we modeled variations in patient, heart and defect size, heart orientation and shape, defect location, organ uptake ratio, etc. The projection data were reconstructed using the OS-EM algorithm with no compensation or with attenuation, detector response and scatter compensation (ADS). The images were then post-filtered and reoriented to generate short-axis slices. A channelized Hotelling observer (CHO) was applied to the short-axis images, and the area under the receiver operating characteristics (ROC) curve (AUC) was computed. For each noise level and reconstruction method, we optimized the number of iterations and cutoff frequencies of the Butterworth filter to maximize the AUC. Using the images obtained with the optimal iteration and cutoff frequency and ADS compensation, we performed human observer studies for four count levels to validate the CHO results. Both CHO and human observer studies demonstrated that observer performance was dependent on the relative magnitude of the quantum noise and the patient variation. When the count level was high, the patient variation dominated, and the AUC increased very slowly with changes in the count level for the same level of anatomic variability. When the count level was low, however, quantum noise dominated, and changes in the count level

  17. Adaptive SPECT

    PubMed Central

    Barrett, Harrison H.; Furenlid, Lars R.; Freed, Melanie; Hesterman, Jacob Y.; Kupinski, Matthew A.; Clarkson, Eric; Whitaker, Meredith K.

    2008-01-01

    Adaptive imaging systems alter their data-acquisition configuration or protocol in response to the image information received. An adaptive pinhole single-photon emission computed tomography (SPECT) system might acquire an initial scout image to obtain preliminary information about the radiotracer distribution and then adjust the configuration or sizes of the pinholes, the magnifications, or the projection angles in order to improve performance. This paper briefly describes two small-animal SPECT systems that allow this flexibility and then presents a framework for evaluating adaptive systems in general, and adaptive SPECT systems in particular. The evaluation is in terms of the performance of linear observers on detection or estimation tasks. Expressions are derived for the ideal linear (Hotelling) observer and the ideal linear (Wiener) estimator with adaptive imaging. Detailed expressions for the performance figures of merit are given, and possible adaptation rules are discussed. PMID:18541485

  18. 99Tcm-methoxy-isobutyl-isonitrile SPECT to evaluate a perfusion index from regional myocardial uptake after exercise and at rest. Results of a four hour protocol in patients with coronary heart disease and in controls.

    PubMed

    Buell, U; Dupont, F; Uebis, R; Kaiser, H J; Kleinhans, E; Reske, S N; Hanrath, P

    1990-02-01

    In 70 patients with angiographically confirmed coronary heart disease and in 10 controls, a 4 h exercise (E) (injection of 150 MBq 99Tcm-MIBI) rest (R) (800 MBq) protocol was employed. Of these, 10 patients with 21 myocardial defects after E received a third injection 24 h after. SPECT was used to image myocardial distribution, and visual findings separated three patterns of perfusion defects after E v. R (reversible [REV], partial reversible (PREV), irreversible (IRR)). Relative regional uptake was obtained from a target-like (33 ROIs) evaluation of short-axis cuts, establishing a perfusion index (PI) by relating the defect uptake to individual maximum uptake (100%) after exercise (PIE), at rest (PIR) and the respective differences Delta PI (PIR-PIE, i.e. filling in by the second 99Tcm-MIBI injection). Visually, the sensitivity was 86% in patients or 69% in involved vessels (stenoses of greater than 33%). Vascular supply areas revealed minimal PIE values of 74.7 +/- 10.6% (control), 62.4 +/- 9.2% (REV), 46.1 +/- 7.7% (PREV) and 33.5 +/- 9.9% (IRR) (p less than 0.01). Delta PI was +13.2% or +10.1% in REV or PREV (n.s.) and +2.1% in IRR (p less than 0.01) or -0.2% in controls. PIE values did not correlate to the degree of stenosis. In areas with old myocardial infarction, the same sequence of significant decrease of PIE with reversibility occurred, independent of the patency of the supplying vessel. 33 of 35 IRR defects (94.3%) revealed PIE of less than 45%, thus predicting IRR already after the E examination. PIR values from the 4 h protocol correlated to PIR values 24 h thereafter with r = 0.94 (n = 21). 99Tcm-MIBI may be employed in a short one day E-R protocol in clinical routine. Evaluation of PI seems to be a promising tool to quantify visual defects aimed at describing the perfusional state of the terminal vascular supply area. PMID:2356070

  19. [Cardiac SPECT/CT: correlation between atherosclerosis, significant coronary artery stenoses and myocardial perfusion parameters in patients with known coronary artery disease].

    PubMed

    Ubleis, C; Rist, C; Griesshammer, I; Becker, A; Becker, C; Hacker, M

    2010-04-01

    Invasive coronary angiography (ICA) and CT angiography (CTA) both enable significant coronary artery stenoses to be detected, but they are not suitable for assessing their hemodynamic relevance. This can be accomplished using myocardial perfusion scintigraphy (MPS) which, however, has limited specificity and spatial resolution. Regarding patients with known coronary artery disease (CAD) it is furthermore important to stratify patient's individual risk for severe cardiac events to guide therapy management.The results of our investigations in 158 patients with CAD indicate that global and regional calcium scores (CAC) do not correlate with the presence of myocardial perfusion defects and significant coronary artery stenoses, respectively. However, published literature has reported CAC as being an independent predictor of long-time survival.For clinical purposes it seems that non-invasive diagnostics with CTA, MPS and CAC screening can be useful even in patients with known CAD. CAC and global scar burden enable long-term risk-stratification, whereas fusion of CTA and MPS is useful to detect the culprit lesion of relevant perfusion defects and to select options for revascularization. PMID:20333503

  20. The association of increased stomach wall radiotracer uptake with prolonged use of omeprazole capsules on myocardial perfusion imaging (MPI) using 99mTc-sestamibi SPECT.

    PubMed

    Javadi, Hamid; Jallalat, Sara; Semnani, Shahriar; Mogharrabi, Mehdi; Nabipour, Iraj; Tabib, Seyed Masoud; Abbaszadeh, Moloud; Assadi, Majid

    2013-01-01

    Myocardial perfusion imaging (MPI) is widely used in routine practice for diagnosis and risk stratification of coronary artery disease (CAD). Intense curvilinear activity in the stomach wall of a patient was seen on MPI raw data. This phenomenon was completely dissimilar to the familiar intraluminal gastric reflux of sestamibi. This observed activity could have resulted in false-positive or false-negative artifacts - and inaccurate diagnosis - of the inferior wall of the left ventricle after MPI processing. On further exploration, the current researchers found that the patient had a history of 10-year Omeprazole capsule consumption. The authors present this infrequent case of intense stomach uptake to stress the related clinical and diagnostic implications with the aim to stimulate acute awareness of possible, unexpected infringements on image quality that could potentially interfere with accurate interpretation of the data. PMID:24068640

  1. Cardiac dedicated ultrafast SPECT cameras: new designs and clinical implications.

    PubMed

    Garcia, Ernest V; Faber, Tracy L; Esteves, Fabio P

    2011-02-01

    Myocardial perfusion imaging (MPI) using nuclear cardiology techniques has been widely applied in clinical practice because of its well-documented value in the diagnosis and prognosis of coronary artery disease. Industry has developed innovative designs for dedicated cardiac SPECT cameras that constrain the entire detector area to imaging just the heart. New software that recovers image resolution and limits image noise has also been implemented. These SPECT innovations are resulting in shortened study times or reduced radiation doses to patients, promoting easier scheduling, higher patient satisfaction, and, importantly, higher image quality. This article describes these cardiocentric SPECT software and hardware innovations, which provide a strong foundation for the continued success of myocardial perfusion SPECT. PMID:21233190

  2. Cardiac sarcoidosis demonstrated by Tl-201 and Ga-67 SPECT imaging

    SciTech Connect

    Taki, J.; Nakajima, K.; Bunko, H.; Ohguchi, M.; Tonami, N.; Hisada, K. )

    1990-09-01

    Ga-67 and Tl-201 SPECT was performed to evaluate cardiac sarcoidosis in a 15-year-old boy. Tl-201 SPECT imaging showed decreased uptake in the inferior to lateral wall and Ga-67 accumulation in the area of decreased Tl-201 uptake. These findings suggested cardiac sarcoidosis, and cardiac biopsy confirmed this diagnosis. After corticosteroid therapy, myocardial uptake of Ga-67 disappeared and myocardial TI-201 uptake became more homogeneous.

  3. Post-Coronary Artery Bypass Grafting Myocardial Ischemia Caused by an Overgrown Left Internal Thoracic Artery Side Branch

    PubMed Central

    Kim, Eung Re; Oh, Se Jin; Kang, Hyun-Jae; Kim, Ki-Bong

    2014-01-01

    We present a patient who developed recurrent angina after coronary artery bypass grafting (CABG). Myocardial single-photon emission computed tomography (SPECT) demonstrated deterioration in the myocardial perfusion, and coronary angiography revealed an overgrown side branch of the grafted left internal thoracic artery (ITA); otherwise, there were no significant changes compared with previous imaging studies obtained after the CABG. After percutaneous embolization of the grafted left ITA side branch, the angina was resolved and myocardial SPECT showed improved perfusion. PMID:25346902

  4. Recent advances in SPECT

    SciTech Connect

    Tsui, Benjamin M. W.

    1998-08-28

    Single photon emission computed tomography (SPECT) is a medical imaging modality that combines conventional nuclear medicine imaging technique and methods of computed tomography (CT). From images that represent the biodistribution of the injected radiopharmaceutical in the patient, SPECT provides functional information that is unique. The first SPECT system was developed in the sixties. However, early progress of SPECT was hampered by the lack of adequate image reconstruction methods. The development of x-ray CT and image reconstruction methods in the seventies spurred a renewed interest in SPECT. In 1981, the first commercial SPECT system based on a single rotating camera was available for clinical use. Today, most modern SPECT systems consist of multiple cameras that rotate around the patients. They have better spatial resolution and higher detection efficiency as compared to the earlier single camera systems. Recently, a new generation of dual camera systems allowing for coincidence imaging of positron emitting radiopharmaceuticals has emerged in the commercial market. Additionally, new quantitative image reconstruction methods are under development. They compensate for image degrading factors including attenuation, collimator-detector blurring and scatter. Also, they result in SPECT images with improved image quality and more accurately represent the three-dimensional radioactivity distribution in the patient. Such advances in radiopharmaceuticals, instrumentation, image reconstruction, compensation methods, and clinical applications have fueled a steady growth of SPECT as an important diagnostic tool in patient management.

  5. Design and assessment of cardiac SPECT systems

    NASA Astrophysics Data System (ADS)

    Lee, Chih-Jie

    Single-photon emission computed tomography (SPECT) is a modality widely used to detect myocardial ischemia and myocardial infarction. Objectively assessing and comparing different SPECT systems is important so that the best detectability of cardiac defects can be achieved. Whitaker, Clarkson, and Barrett's study on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than reconstruction data. Thus, this observer model assesses overall hardware performance independent by any reconstruction algorithm. In addition, we will show that the run time of image-quality studies is significantly reduced. Several systems derived from the GE CZT-based dedicated cardiac SPECT camera Discovery 530c design, which is officially named the Alcyone Technology: Discovery NM 530c, were assessed using the performance of the SLO for the task of detecting cardiac defects and estimating the properties of the defects. Clinically, hearts can be virtually segmented into three coronary artery territories: left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA). One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can correctly predict in which territory the defect exists. A good estimation of the defect extent from the images is also very helpful for determining the seriousness of the myocardial ischemia. In this dissertation, both locations and extent of defects were estimated by the SLO, and system performance was assessed using localization receiver operating characteristic (LROC) / estimation receiver operating characteristic (EROC) curves. Area under LROC curve (AULC) / area under EROC curve (AUEC) and true positive fraction (TPF) at specific false positive fraction (FPF) can be treated as the gures of merit (FOMs). As the results will show, a

  6. SPECT attenuation correction: an essential tool to realize nuclear cardiology's manifest destiny.

    PubMed

    Garcia, Ernest V

    2007-01-01

    Single photon emission computed tomography (SPECT) myocardial perfusion imaging has attained widespread clinical acceptance as a standard of care for cardiac patients. Yet, physical phenomena degrade the accuracy of how our cardiac images are visually interpreted or quantitatively analyzed. This degradation results in cardiac images in which brightness or counts are not necessarily linear with tracer uptake or myocardial perfusion. Attenuation correction (AC) is a methodology that has evolved over the last 30 years to compensate for this degradation. Numerous AC clinical trials over the last 10 years have shown increased diagnostic accuracy over non-AC SPECT for detecting and localizing coronary artery disease, particularly for significantly increasing specificity and normalcy rate. This overwhelming evidence has prompted our professional societies to issue a joint position statement in 2004 recommending the use of AC to maximize SPECT diagnostic accuracy and clinical usefulness. Phantom and animal studies have convincingly shown how SPECT AC recovers the true regional myocardial activity concentration, while non-AC SPECT does not. Thus, AC is also an essential tool for extracting quantitative parameters from all types of cardiac radionuclide distributions, and plays an important role in establishing cardiac SPECT for flow, metabolic, innervation, and molecular imaging, our manifest destiny. PMID:17276302

  7. FDG cardiac SPECT versus PET: Relation to SPECT radionuclide angiography and thallium scintigraphy

    SciTech Connect

    Srinivasan, G.; Kitsiou, A.N.; Bacharach, S.L.

    1996-05-01

    To determine whether fluorodeoxyglucose (FDG) imaging with SPECT, using high-energy collimation, provides comparable viability information to FDG-PET, 16 pts with chronic CAD undergoing FDG-PET studies were reimaged with SPECT immediately after the PET acquisition was completed. All pts had stress (S)-redistribution (RD)-reinjection (RI) thallium (TL) studies and a subset of 12 pts had SPECT radionuclide angiography (RNA). The LV was divided into 4 long-axis tomograms encompassing the entire LV and the myocardial activity of 11 sectors per tomogram was assessed quantitatively. The mean counts per pixel of corresponding FDG-SPECT, FDG-PET, RD and RI-TL images were normalized to that sector having peak activity on TL-S and compared on the basis of severity of reduction in FDG and TL activity as follows: normal (NI = >85% of peak), mild-moderate (50-86%) and severe (<50%). FDG-SPECT provided concordant viability information with FDG-PET (NI/mild-mod vs severe) in 581 of 615 (94%) sectors and with TL S-RD-RI(NI/reversible/mild-mod vs severe irreversible) in 555 or 615 (90%) sectors. To facilitate comparison of FDG and TK uptake with regional contraction, these sectors were grouped into 5 regions (anterior, septal, apex, inferior and lateral). These data suggest that most normal/HK regions are viable both by FDG and TL. Among a total of 33 sHK and AK/DK regions, in which viability is a clinical concern, 17 (52%) were viable by TL, 22 (67%) by FDG-SPECT and 24 (73%) by FDG-PET (p=NS). These data suggest that most normal/HK regions are viable both by FDG and TL. Among a total of 33 sHK and AK/DK regions, in which viability is a clinical concern, 17 (52%) were viable by TL, 22 (67%) by FDG-SPECT and 24 (73%) by FDG-PET (p=NS). These data affirm the good overall correlation between FDG uptake and TL for differentiating viable from nonviable myocardium in asynergic regions regardless of the technology applied, PET or SPECT.

  8. Comparison of 4D-microSPECT and microCT for murine cardiac function

    PubMed Central

    Befera, Nicholas T.; Badea, Cristian T.; Johnson, G. Allan

    2014-01-01

    Purpose The objective of this study was to compare a new generation of four-dimensional (4D) microSPECT with microCT for quantitative in vivo assessment of murine cardiac function. Procedures 4D isotropic cardiac images were acquired from normal C57BL/6 mice with either microSPECT at 350-micron resolution (n=6) or microCT at 88-micron resolution (n=6). One additional mouse with myocardial infarction (MI) was scanned with both modalities. Prior to imaging, mice were injected with either 99mTc -tetrofosmin for microSPECT, or a liposomal blood pool contrast agent for microCT. Segmentation of the left ventricle (LV) was performed using Vitrea (Vital Images) software, to derive global and regional function. Results Measures of global LV function between microSPECT and microCT groups were comparable (e.g. ejection fraction=71±6%-microSPECT and 68±4%-microCT). Regional functional indices (wall motion, wall thickening, regional ejection fraction) were also similar for the two modalities. In the mouse with MI, microSPECT identified a large perfusion defect that was not evident with microCT. Conclusions Despite lower spatial resolution, microSPECT was comparable to microCT in the quantitative evaluation of cardiac function. MicroSPECT offers an advantage over microCT in the ability to evaluate myocardial perfusion radiotracer distribution and function simultaneously. MicroSPECT should be considered as an alternative to microCT and MR for preclinical cardiac imaging in the mouse. PMID:24037175

  9. Prognostic Significance of Imaging Myocardial Sympathetic Innervation.

    PubMed

    Malhotra, Saurabh; Fernandez, Stanley F; Fallavollita, James A; Canty, John M

    2015-08-01

    There has been a longstanding interest in understanding whether the presence of inhomogeneity in myocardial sympathetic innervation can predict patients at risk of sudden cardiac arrest from lethal ventricular arrhythmias. The advent of radiolabeled norepinephrine analogs has allowed this to be imaged in patients with ischemic and non-ischemic cardiomyopathy using single, photon emission computed tomography (SPECT) and positron emission tomography (PET). Several observational studies have demonstrated that globally elevated myocardial sympathetic tone (as reflected by reduced myocardial norepinephrine analog uptake) can predict composite cardiac end-points including total cardiovascular mortality. More recent studies have indicated that quantifying the extent of regional denervation can predict the risk of lethal ventricular arrhythmias and sudden cardiac death. This review will summarize our current understanding of the prognostic significance of altered myocardial sympathetic innervation. PMID:26087899

  10. Proceedings of the cardiac PET summit meeting 12 may 2014: Cardiac PET and SPECT instrumentation.

    PubMed

    Garcia, Ernest V

    2015-06-01

    Advances in PET and SPECT and imaging hardware and software are vastly improving the noninvasive evaluation of myocardial perfusion and function. PET perfusion imaging has benefitted from the introduction of novel detectors that now allow true 3D imaging, and precise attenuation correction (AC). These developments have also resulted in perfusion images with higher spatial and contrast resolution that may be acquired in shorter protocols and/or with less patient radiation exposure than traditional PET or SPECT studies. Hybrid PET/CT cameras utilize transmission computed tomographic (CT) scans for AC, and offer the additional clinical advantages of evaluating coronary calcium and myocardial anatomy but at a higher cost than PET scanners that use (68)Ge radioactive line sources. As cardiac PET systems continue to improve, dedicated cardiac SPECT systems are also undergoing a profound change in their design. The scintillation camera general purpose design is being replaced with systems with multiple detectors focused on the heart yielding 5 to 10 times the sensitivity of conventional SPECT. As a result, shorter acquisition times and/or lower tracer doses produce higher quality SPECT images than were possible before. This article reviews these concepts and compares the attributes of PET and SPECT instrumentation. PMID:25824018

  11. Nuclear cardiac imaging for the assessment of myocardial viability

    PubMed Central

    Slart, R.H.J.A.; Bax, J.J.; van der Wall, E.E.; van Veldhuisen, D.J.; Jager, P.L.; Dierckx, R.A.

    2005-01-01

    An important aspect of the diagnostic and prognostic work-up of patients with ischaemic cardiomyopathy is the assessment of myocardial viability. Patients with left ventricular dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischaemia but at the same time benefit most from revascularisation. It is important to identify viable myocardium in these patients, and radionuclide myocardial scintigraphy is an excellent tool for this. Single-photon emission computed tomography perfusion scintigraphy (SPECT), whether using 201thallium, 99mTc-sestamibi, or 99mTc- tetrofosmin, in stress and/or rest protocols, has consistently been shown to be an effective modality for identifying myocardial viability and guiding appropriate management. Metabolic and perfusion imaging with positron emission tomography radiotracers frequently adds additional information and is a powerful tool for predicting which patients will have an improved outcome from revascularisation. New techniques in the nuclear cardiology field, such as attenuation corrected SPECT, dual isotope simultaneous acquisition (DISA) SPECT and gated FDG PET are promising and will further improve the detection of myocardial viability. Also the combination of multislice computed tomography scanners with PET opens possibilities of adding coronary calcium scoring and noninvasive coronary angiography to myocardial perfusion imaging and quantification. ImagesFigure 1Figure 2Figure 3 PMID:25696432

  12. Myocardial Bridge

    MedlinePlus

    ... artery. See also on this site: Ask a Texas Heart Institute Doctor: Search "myocardial bridge" Updated August ... comments. Terms of Use and Privacy Policy © Copyright Texas Heart Institute All rights reserved.

  13. First Results of Small Animal Imaging Spect Detector for Cardiovascular Disease Studies on Mice

    NASA Astrophysics Data System (ADS)

    Magliozzi, M. L.; Ballerini, M.; Cisbani, E.; Colilli, S.; Cusanno, F.; Fratoni, R.; Garibaldi, F.; Giuliani, F.; Gricia, M.; Lucentini, M.; Santavenere, F.; Torrioli, S.; Veneroni, P.; Majewsky, S.; Mok, S. P. G.; Tsui, B. M. W.; Wang, Y.; Marano, G.; Musumeci, M.; Palazzesi, S.; Ciccariello, G.; de Vincentis, G.; Accorsi, R.

    2008-06-01

    We have developed a compact, open, Dual Head pinhole SPECT system for high resolution molecular imaging with radionuclides of mice, dedicated mainly to preclinical study of stem cells capability to recover myocardial infarction. The gamma detector is made of pinhole tungsten collimators, pixellated scintillators, matrix of multi-anode PMTs and individual channel readout. Measurements have been performed on phantoms and live mice devoted initially to test and calibrate the system and to optimize protocols. The implemented system and the first results will be presented, demonstrating the effectiveness of our dedicated SPECT detector for small animal imaging.

  14. Panic attack triggering myocardial ischemia documented by myocardial perfusion imaging study. A case report

    PubMed Central

    2012-01-01

    Background Chest pain, a key element in the investigation of coronary artery disease is often regarded as a benign prognosis when present in panic attacks. However, panic disorder has been suggested as an independent risk factor for long-term prognosis of cardiovascular diseases and a trigger of acute myocardial infarction. Objective Faced with the extreme importance in differentiate from ischemic to non-ischemic chest pain, we report a case of panic attack induced by inhalation of 35% carbon dioxide triggering myocardial ischemia, documented by myocardial perfusion imaging study. Discussion Panic attack is undoubtedly a strong component of mental stress. Patients with coronary artery disease may present myocardial ischemia in mental stress response by two ways: an increase in coronary vasomotor tone or a sympathetic hyperactivity leading to a rise in myocardial oxygen consumption. Coronary artery spasm was presumed to be present in cases of cardiac ischemia linked to panic disorder. Possibly the carbon dioxide challenge test could trigger myocardial ischemia by the same mechanisms. Conclusion The use of mental stress has been suggested as an alternative method for myocardial ischemia investigation. Based on translational medicine objectives the use of CO2 challenge followed by Sestamibi SPECT could be a useful method to allow improved application of research-based knowledge to the medical field, specifically at the interface of PD and cardiovascular disease. PMID:22999016

  15. Molecular SPECT Imaging: An Overview

    PubMed Central

    Khalil, Magdy M.; Tremoleda, Jordi L.; Bayomy, Tamer B.; Gsell, Willy

    2011-01-01

    Molecular imaging has witnessed a tremendous change over the last decade. Growing interest and emphasis are placed on this specialized technology represented by developing new scanners, pharmaceutical drugs, diagnostic agents, new therapeutic regimens, and ultimately, significant improvement of patient health care. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) have their signature on paving the way to molecular diagnostics and personalized medicine. The former will be the topic of the current paper where the authors address the current position of the molecular SPECT imaging among other imaging techniques, describing strengths and weaknesses, differences between SPECT and PET, and focusing on different SPECT designs and detection systems. Radiopharmaceutical compounds of clinical as well-preclinical interest have also been reviewed. Moreover, the last section covers several application, of μSPECT imaging in many areas of disease detection and diagnosis. PMID:21603240

  16. Investigation of dynamic SPECT measurements of the arterial input function in human subjects using simulation, phantom and human studies

    PubMed Central

    Winant, Celeste D; Aparici, Carina Mari; Zelnik, Yuval R; Reutter, Bryan W; Sitek, Arkadiusz; Bacharach, Stephen L; Gullberg, Grant T

    2012-01-01

    Computer simulations, a phantom study and a human study were performed to determine whether a slowly rotating single-photon computed emission tomography (SPECT) system could provide accurate arterial input functions for quantification of myocardial perfusion imaging using kinetic models. The errors induced by data inconsistency associated with imaging with slow camera rotation during tracer injection were evaluated with an approach called SPECT/P (dynamic SPECT from positron emission tomography (PET)) and SPECT/D (dynamic SPECT from database of SPECT phantom projections). SPECT/P simulated SPECT-like dynamic projections using reprojections of reconstructed dynamic 94Tc-methoxyisobutylisonitrile (94Tc-MIBI) PET images acquired in three human subjects (1 min infusion). This approach was used to evaluate the accuracy of estimating myocardial wash-in rate parameters K1 for rotation speeds providing 180° of projection data every 27 or 54 s. Blood input and myocardium tissue time-activity curves (TACs) were estimated using spatiotemporal splines. These were fit to a one-compartment perfusion model to obtain wash-in rate parameters K1. For the second method (SPECT/D), an anthropomorphic cardiac torso phantom was used to create real SPECT dynamic projection data of a tracer distribution derived from 94Tc-MIBI PET scans in the blood pool, myocardium, liver and background. This method introduced attenuation, collimation and scatter into the modeling of dynamic SPECT projections. Both approaches were used to evaluate the accuracy of estimating myocardial wash-in parameters for rotation speeds providing 180° of projection data every 27 and 54 s. Dynamic cardiac SPECT was also performed in a human subject at rest using a hybrid SPECT/CT scanner. Dynamic measurements of 99mTc-tetrofosmin in the myocardium were obtained using an infusion time of 2 min. Blood input, myocardium tissue and liver TACs were estimated using the same spatiotemporal splines. The spatiotemporal maximum

  17. Comparative study of diverse model building strategies for 3D-ASM segmentation of dynamic gated SPECT data

    NASA Astrophysics Data System (ADS)

    Tobon-Gomez, C.; Butakoff, C.; Ordas, S.; Aguade, S.; Frangi, A. F.

    2007-03-01

    Over the course of the last two decades, myocardial perfusion with Single Photon Emission Computed Tomography (SPECT) has emerged as an established and well-validated method for assessing myocardial ischemia, viability, and function. Gated-SPECT imaging integrates traditional perfusion information along with global left ventricular function. Despite of these advantages, inherent limitations of SPECT imaging yield a challenging segmentation problem, since an error of only one voxel along the chamber surface may generate a huge difference in volume calculation. In previous works we implemented a 3-D statistical model-based algorithm for Left Ventricle (LV) segmentation of in dynamic perfusion SPECT studies. The present work evaluates the relevance of training a different Active Shape Model (ASM) for each frame of the gated SPECT imaging acquisition in terms of their subsequent segmentation accuracy. Models are subsequently employed to segment the LV cavity of gated SPECT studies of a virtual population. The evaluation is accomplished by comparing point-to-surface (P2S) and volume errors, both against a proper Gold Standard. The dataset comprised 40 voxel phantoms (NCAT, Johns Hopkins, University of of North Carolina). Monte-Carlo simulations were generated with SIMIND (Lund University) and reconstructed to tomographic slices with ASPIRE (University of Michigan).

  18. Filters in 2D and 3D Cardiac SPECT Image Processing

    PubMed Central

    Ploussi, Agapi; Synefia, Stella

    2014-01-01

    Nuclear cardiac imaging is a noninvasive, sensitive method providing information on cardiac structure and physiology. Single photon emission tomography (SPECT) evaluates myocardial perfusion, viability, and function and is widely used in clinical routine. The quality of the tomographic image is a key for accurate diagnosis. Image filtering, a mathematical processing, compensates for loss of detail in an image while reducing image noise, and it can improve the image resolution and limit the degradation of the image. SPECT images are then reconstructed, either by filter back projection (FBP) analytical technique or iteratively, by algebraic methods. The aim of this study is to review filters in cardiac 2D, 3D, and 4D SPECT applications and how these affect the image quality mirroring the diagnostic accuracy of SPECT images. Several filters, including the Hanning, Butterworth, and Parzen filters, were evaluated in combination with the two reconstruction methods as well as with a specified MatLab program. Results showed that for both 3D and 4D cardiac SPECT the Butterworth filter, for different critical frequencies and orders, produced the best results. Between the two reconstruction methods, the iterative one might be more appropriate for cardiac SPECT, since it improves lesion detectability due to the significant improvement of image contrast. PMID:24804144

  19. Radionuclide Tracers for Myocardial Perfusion Imaging and Blood Flow Quantification.

    PubMed

    deKemp, Robert A; Renaud, Jennifer M; Klein, Ran; Beanlands, Rob S B

    2016-02-01

    Myocardial perfusion imaging is performed most commonly using Tc-99m-sestamibi or tetrofosmin SPECT as well as Rb-82-rubidium or N-13-ammonia PET. Diseased-to-normal tissue contrast is determined by the tracer retention fraction, which decreases nonlinearly with flow. Reduced tissue perfusion results in reduced tracer retention, but the severity of perfusion defects is typically underestimated by 20% to 40%. Compared to SPECT, retention of the PET tracers is more linearly related to flow, and therefore, the perfusion defects are measured more accurately using N-13-ammonia or Rb-82. PMID:26590778

  20. New Trends in Radionuclide Myocardial Perfusion Imaging

    PubMed Central

    Hung, Guang-Uei; Wang, Yuh-Feng; Su, Hung-Yi; Hsieh, Te-Chun; Ko, Chi-Lun; Yen, Ruoh-Fang

    2016-01-01

    Radionuclide myocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) has been widely used clinically as one of the major functional imaging modalities for patients with coronary artery disease (CAD) for decades. Ample evidence has supported the use of MPI as a useful and important tool in the diagnosis, risk stratification and treatment planning for CAD. Although popular in the United States, MPI has become the most frequently used imaging modality among all nuclear medicine tests in Taiwan. However, it should be acknowledged that MPI SPECT does have its limitations. These include false-positive results due to certain artifacts, false-negative due to balanced ischemia, complexity and adverse reaction arising from current pharmacological stressors, time consuming nature of the imaging procedure, no blood flow quantitation and relatively high radiation exposure. The purpose of this article was to review the recent trends in nuclear cardiology, including the utilization of positron emission tomography (PET) for MPI, new stressor, new SPECT camera with higher resolution and higher sensitivity, dynamic SPECT protocol for blood flow quantitation, new software of phase analysis for evaluation of LV dyssynchrony, and measures utilized for reducing radiation exposure of MPI. PMID:27122946

  1. Dynamic heart-in-thorax phantom for functional SPECT

    SciTech Connect

    Celler, A.; Lyster, D.; Farncombe, T.

    1996-12-31

    We have designed and built a dynamic heart-in-thorax phantom to be used as a primary tool during the experimental verification of the performance of the quantitative dynamic functional imaging method we are developing for standard rotating single photon emission computed tomography (SPECT) cameras. The phantom consists of two independent parts (i) a dynamic heart model with the possibility of mounting {open_quotes}defects{close_quotes} inside it and (ii) a non-uniform thorax model with lungs and spinal cord, and uses the fact that the washout of a tracer by dilution is governed by a linear first order equation, the same type of equation as is used to model time-activity distribution in myocardial viability studies. Tests of the dynamic performance of the phantom in planar scanning mode have confirmed the validity of these assumptions. Also the preliminary results obtained in SPECT mode show that the values of characteristic times could be experimentally determined and that these values agreed well with the values preset on the phantom. We consider that the phantom is ready for extensive use in studies into development of the dynamic SPECT method.

  2. Prognostic evaluation in obese patients using a dedicated multipinhole cadmium-zinc telluride SPECT camera.

    PubMed

    De Lorenzo, Andrea; Peclat, Thais; Amaral, Ana Carolina; Lima, Ronaldo S L

    2016-02-01

    The purpose of this study is to evaluate the prognostic value of myocardial perfusion SPECT obtained in CZT cameras (CZT-SPECT) with multipinhole collimation in obese patients. CZT-SPECT may be technically challenging in the obese, and its prognostic value remains largely unknown. Patients underwent single-day, rest/stress (supine and prone) imaging. Images were visually inspected and graded as poor, fair or good/excellent. Summed stress and difference scores (SSS and SDS, respectively) were converted into percentages of total perfusion defect and of ischemic defect by division by the maximum possible score. Obesity was defined as a body mass index (BMI) ≥ 30 kg/m(2) and classified as class I (BMI 30-34.9 kg/m(2)), II (BMI 35-39.9 kg/m(2)), or III (BMI ≥ 40 kg/m(2)). Patients were followed-up by telephone interview for the occurrence of all-cause death, myocardial infarction or revascularization. A Cox proportional hazards analysis was used to assess the independent predictors of death. Among 1396 patients, 365 (26.1 %) were obese (mean BMI 33.9 ± 3.6; 17.5 % class I, 3.4 % class II, and 3.4 % class III). Image quality was good/excellent in 94.5 % of the obese patients. The annualized mortality rates were not significantly different among obese and non-obese patients, being <1 % with normal CZT-SPECT, and increased with the degree of scan abnormality in both obese and non-obese patients. Age, the use of pharmacologic stress and an abnormal CZT-SPECT, but not obesity, were independent predictors of death. In obese patients, single-day rest/stress CZT-SPECT with a multipinhole camera provides prognostic discrimination with high image quality. PMID:26424491

  3. Radiopharmaceuticals for SPECT cancer detection

    NASA Astrophysics Data System (ADS)

    Chernov, V. I.; Medvedeva, A. A.; Zelchan, R. V.; Sinilkin, I. G.; Stasyuk, E. S.; Larionova, L. A.; Slonimskaya, E. M.; Choynzonov, E. L.

    2016-08-01

    The purpose of the study was to assess the efficacy of single photon emission computed tomography (SPECT) with 199Tl and 99mTc-MIBI in the detection of breast, laryngeal and hypopharyngeal cancers. A total of 220 patients were included into the study: 120 patients with breast lesions (100 patients with breast cancer and 20 patients with benign breast tumors) and 100 patients with laryngeal/hypopharyngeal diseases (80 patients with laryngeal/hypopharyngeal cancer and 20 patients with benign laryngeal/hypopharyngeal lesions). No abnormal 199Tl uptake was seen in all patients with benign breast and laryngeal lesions, indicating a 100% specificity of 199Tl SPECT. In the breast cancer patients, the increased 199Tl uptake in the breast was visualized in 94.8% patients, 99mTc-MIBI—in 93.4% patients. The increased 199Tl uptake in axillary lymph nodes was detected in 60% patients, and 99mTc-MIBI—in 93.1% patients. In patients with laryngeal/hypopharyngeal cancer, the sensitivity of SPECT with 199Tl and 99mTc-MIBI was 95%. The 199Tl SPECT sensitivity in identification of regional lymph node metastases in the patients with laryngeal/hypopharyngeal cancer was 75% and the 99mTc-MIBI SPECT sensitivity was 17%. The data obtained showed that SPECT with 199Tl and 99mTc-MIBI can be used as one of the additional imaging methods in detection of tumors.

  4. Radiopharmaceuticals for SPECT Cancer Detection

    NASA Astrophysics Data System (ADS)

    Chernov, V. I.; Medvedeva, A. A.; Zelchan, R. V.; Sinilkin, I. G.; Stasyuk, E. S.; Larionova, L. A.; Slonimskaya, E. M.; Choynzonov, E. L.

    2016-06-01

    The purpose of the study was to assess the efficacy of single photon emission computed tomography (SPECT) with 199Tl and 99mTc-MIBI in the detection of breast, laryngeal and hypopharyngeal cancers. Materials and Methods: a total of 220 patients were included into the study. Of them, there were 120 patients with breast lesions (100 patients with breast cancer and 20 patients with benign breast tumors) and '00 patients with laryngeal/hypopharyngeal diseases (80 patients with laryngeal/hypopharyngeal cancer and 20 patients with benign laryngeal/hypopharyngeal lesions). Results: no abnormal 199Tl uptake was seen in all patients with benign breast and laryngeal lesions, indicating a 100% specificity of 199Tl SPECT. In breast cancer patients, increased 199Tl uptake in the breast was visualized in 94.8% patients, 99mTc-MIBI in 93.4% patients. Increased 199Tl uptake in axillary lymph nodes was detected in 60% patients and 99mTc-MIBI in 93.1% patients. In patients with laryngeal/hypopharyngeal cancer, sensitivity of SPECT with 199Tl and 99mTc-MIBI were 95%. The 199Tl SPECT sensitivity in identification of regional lymph node metastases in patients with laryngeal/hypopharyngeal cancer was 75% and the 99mTc-MIBI SPECT sensitivity was 17%. Conclusion: the data obtained show that SPECT with 199Tl and 99mTc-MIBI can be used as one of the additional imaging methods in detection of tumors.

  5. [PET and SPECT in epilepsy].

    PubMed

    Setoain, X; Carreño, M; Pavía, J; Martí-Fuster, B; Campos, F; Lomeña, F

    2014-01-01

    Epilepsy is one of the most frequent chronic neurological disorders, affecting 1-2% of the population. Patients with complex partial drug resistant episodes may benefit from a surgical treatment consisting in the excision of the epileptogenic area. Localization of the epileptogenic area was classically performed with video-EEG and magnetic resonance (MR). Recently, functional neuroimaging studies of Nuclear Medicine, positron emission tomography (PET) and single photon emission tomography (SPECT) have demonstrated their utility in the localization of the epileptogenic area prior to surgery. Ictal SPECT with brain perfusion tracers show an increase in blood flow in the initial ictal focus, while PET with (18)FDG demonstrates a decrease of glucose metabolism in the interictal functional deficit zone. In this review, the basic principles and methodological characteristics of the SPECT and PET in epilepsy are described. The ictal SPECT injection mechanism, different patterns of perfusion based on the time of ictal, postictal or interictal injection are detailed and the different diagnostic sensitivities of each one of these SPECT are reviewed. Different methods of analysis of the images with substraction and fusion systems with the MR are described. Similarly, the injection methodology, quantification and evaluation of the images of the PET in epilepsy are described. Finally, the main clinical indications of SPECT and PET in temporal and extratemporal epilepsy are detailed. PMID:24565567

  6. Modelling photon transport in non-uniform media for SPECT with a vectorized Monte Carlo code.

    PubMed

    Smith, M F

    1993-10-01

    A vectorized Monte Carlo code has been developed for modelling photon transport in non-uniform media for single-photon-emission computed tomography (SPECT). The code is designed to compute photon detection kernels, which are used to build system matrices for simulating SPECT projection data acquisition and for use in matrix-based image reconstruction. Non-uniform attenuating and scattering regions are constructed from simple three-dimensional geometric shapes, in which the density and mass attenuation coefficients are individually specified. On a Stellar GS1000 computer, Monte Carlo simulations are performed between 1.6 and 2.0 times faster when the vector processor is utilized than when computations are performed in scalar mode. Projection data acquired with a clinical SPECT gamma camera for a line source in a non-uniform thorax phantom are well modelled by Monte Carlo simulations. The vectorized Monte Carlo code was used to stimulate a 99Tcm SPECT myocardial perfusion study, and compensations for non-uniform attenuation and the detection of scattered photons improve activity estimation. The speed increase due to vectorization makes Monte Carlo simulation more attractive as a tool for modelling photon transport in non-uniform media for SPECT. PMID:8248288

  7. Detection of coronary artery stenosis in children with Kawasaki disease. Usefulness of pharmacologic stress sup 201 Tl myocardial tomography

    SciTech Connect

    Kondo, C.; Hiroe, M.; Nakanishi, T.; Takao, A. )

    1989-09-01

    This study determined the feasibility and accuracy of quantitative 201Tl myocardial single-photon emission computed tomography (SPECT) after dipyridamole infusion to detect coronary obstructive lesions in children with Kawasaki disease. 201Tl distribution after dipyridamole infusion was measured in 23 normal children, and with these normal values, quantitative analysis of SPECT was performed in 49 patients. Thirty-four patients had coronary stenosis 90% or greater on angiograms. Side effects resulting from systemic vasodilation were observed in about 70%. Angina pectoris and ischemic ST changes were observed only in patients with coronary stenosis. These symptoms disappeared after aminophylline infusion. Results of visual and quantitative analysis of SPECT were compared. SPECT data were shown on two-dimensional polar maps, and the extent and severity scores were calculated. The sensitivity of SPECT for detection of overall coronary stenosis was 91% (visual analysis) and 88% (quantitative analysis). The specificity of SPECT was 60% visually and 93% quantitatively. The sensitivity of quantitative analysis to detect individual coronary stenosis was similar to that of visual analysis. However, the specificity of visual analysis to detect individual coronary artery stenosis was significantly less than that of quantitative analysis. From these data, we conclude that quantitative analysis of myocardial SPECT after dipyridamole infusion is a safe and accurate diagnostic method for identifying coronary stenosis in children with Kawasaki disease.

  8. Progress in BazookaSPECT

    PubMed Central

    Miller, Brian W.; Barber, H. Bradford; Furenlid, Lars R.; Moore, Stephen K.; Barrett, Harrison H.

    2010-01-01

    Recent progress on a high-resolution, photon-counting gamma-ray and x-ray imager called BazookaSPECT is presented. BazookaSPECT is an example of a new class of scintillation detectors based on integrating detectors such as CCD(charge-coupled device) or CMOS(complementary metal-oxide semiconductor) sensors. BazookaSPECT is unique in that it makes use of a scintillator in close proximity to a microchannel plate-based image intensifier for up-front optical amplification of scintillation light. We discuss progress made in bringing about compact BazookaSPECT modules and in real-time processing of event data using graphics processing units (GPUs). These advances are being implemented in the design of a high-resolution rodent brain imager called FastSPECT III. A key benefit of up-front optical gain is that any CCD/CMOS sensor can now be utilized for photon counting. We discuss the benefits and feasibility of using CMOS sensors as photon-counting detectors for digital radiography, with application in mammography and computed tomography (CT). We present as an appendix a formal method for comparing various photon-counting integrating detectors using objective statistical criteria. PMID:21297897

  9. Quantification of myocardial infarction: a comparison of single photon-emission computed tomography with pyrophosphate to serial plasma MB-creatine kinase measurements

    SciTech Connect

    Jansen, D.E.; Corbett, J.R.; Wolfe, C.L.; Lewis, S.E.; Gabliani, G.; Filipchuk, N.; Redish, G.; Parkey, R.W.; Buja, L.M.; Jaffe, A.S.

    1985-08-01

    Single photon-emission computed tomography (SPECT) with /sup 99m/Tc-pyrophosphate (PPi) has been shown to estimate size of myocardial infarction accurately in animals. The authors tested the hypothesis that SPECT with /sup /sup 99m//Tc-PPi and blood pool subtraction can provide prompt and accurate estimates of size of myocardial infarction in patients. SPECT estimates are potentially available early after the onset of infarction and should correlate with estimates of infarct size calculated from serial measurements of plasma MB-creatine kinase (CK) activity. Thirty-three patients with acute myocardial infarction and 16 control patients without acute myocardial infarction were studied. Eleven of the patients had transmural anterior myocardial infarction, 16 had transmural inferior myocardial infarction, and six had nontransmural myocardial infarction. SPECT was performed with a commercially available rotating gamma camera. Identical projection images of the distribution of 99mTc-PPi and the ungated cardiac blood pool were acquired sequentially over 180 degrees. Reconstructed sections were color coded and superimposed for purposes of localization of infarct. Areas of increased PPi uptake within myocardial infarcts were thresholded at 65% of peak activity. The blood pool was thresholded at 50% and subtracted to determine the endocardial border for the left ventricle. Myocardial infarcts ranged in size from 1 to 126 gram equivalents (geq) MB-CK. The correlation of MB-CK estimates of size of infarct with size determined by SPECT (both in geq) was good (r = .89 with a regression line of y = 13.1 + 1.5x).

  10. Evidence for myocardial CT perfusion imaging in the diagnosis of hemodynamically significant coronary artery disease

    PubMed Central

    2015-01-01

    This editorial discusses a recent paper published in the August issue of Radiology about the diagnostic value of myocardial computer tomography (CT) perfusion imaging in the detection of hemodynamically significant coronary stenosis when compared to single-photon emission CT (SPECT) imaging based on a secondary analysis of CORE320 study. Three aspects including high diagnostic sensitivity of CT perfusion imaging, moderate specificity of SPECT imaging and lack of use of attenuation correction in SPECT imaging have been discussed with reference to the current literature, and some suggestions have been highlighted for future studies to improve the diagnostic performance of CT perfusion and SPECT imaging in the diagnostic evaluation of coronary artery disease. PMID:25774349

  11. SPECT imaging with resolution recovery

    SciTech Connect

    Bronnikov, A. V.

    2011-07-01

    Single-photon emission computed tomography (SPECT) is a method of choice for imaging spatial distributions of radioisotopes. Many applications of this method are found in nuclear industry, medicine, and biomedical research. We study mathematical modeling of a micro-SPECT system by using a point-spread function (PSF) and implement an OSEM-based iterative algorithm for image reconstruction with resolution recovery. Unlike other known implementations of the OSEM algorithm, we apply en efficient computation scheme based on a useful approximation of the PSF, which ensures relatively fast computations. The proposed approach can be applied with the data acquired with any type of collimators, including parallel-beam fan-beam, cone-beam and pinhole collimators. Experimental results obtained with a micro SPECT system demonstrate high efficiency of resolution recovery. (authors)

  12. A SPECT camera for combined MRI and SPECT for small animals

    NASA Astrophysics Data System (ADS)

    Meier, D.; Wagenaar, D. J.; Chen, S.; Xu, J.; Yu, J.; Tsui, B. M. W.

    2011-10-01

    We describe an MR-compatible SPECT camera for small animals. The SPECT camera system can be inserted into the bore of a state-of-the-art MRI system and allows researchers to acquire tomographic images from a mouse in-vivo with the MRI and the SPECT acquiring simultaneously. The SPECT system provides functional information, while MRI provides anatomical information. Until today it was impossible to operate conventional SPECT inside the MRI because of mutual interference. The new SPECT technology is based on semiconductor radiation sensors (CZT, ASICs), and it fits into conventional high field MRI systems with a minimum 12-cm bore size. The SPECT camera has an MR-compatible multi-pinhole collimator for mice with a Ø25-mm field-of-view. For the work reported here we assembled a prototype SPECT camera system and acquired SPECT and MRI data from radioactive sources and resolution phantoms using the camera outside and inside the MRI.

  13. A SPECT Camera for Combined MRI and SPECT for Small Animals.

    PubMed

    Meier, D; Wagenaar, D J; Chen, S; Xu, J; Yu, J; Tsui, B M W

    2011-10-01

    We describe an MR-compatible SPECT camera for small animals. The SPECT camera system can be inserted into the bore of a state-of-the-art MRI system and allows researchers to acquire tomographic images from a mouse in-vivo with the MRI and the SPECT acquiring simultaneously. The SPECT system provides functional information, while MRI provides anatomical information. Until today it was impossible to operate conventional SPECT inside the MRI because of mutual interference. The new SPECT technology is based on semiconductor radiation sensors (CZT, ASICs), and it fits into conventional high field MRI systems with a minimum 12-cm bore size. The SPECT camera has an MR-compatible multi-pinhole collimator for mice with a ø25-mm field-of-view. For the work reported here we assembled a prototype SPECT camera system and acquired SPECT and MRI data from radioactive sources and resolution phantoms using the camera outside and inside the MRI. PMID:21966076

  14. A SPECT Camera for Combined MRI and SPECT for Small Animals

    PubMed Central

    Meier, D.; Wagenaar, D. J.; Chen, S.; Xu, J.; Yu, J.; Tsui, B. M. W.

    2010-01-01

    We describe an MR-compatible SPECT camera for small animals. The SPECT camera system can be inserted into the bore of a state-of-the-art MRI system and allows researchers to acquire tomographic images from a mouse in-vivo with the MRI and the SPECT acquiring simultaneously. The SPECT system provides functional information, while MRI provides anatomical information. Until today it was impossible to operate conventional SPECT inside the MRI because of mutual interference. The new SPECT technology is based on semiconductor radiation sensors (CZT, ASICs), and it fits into conventional high field MRI systems with a minimum 12-cm bore size. The SPECT camera has an MR-compatible multi-pinhole collimator for mice with a ø25-mm field-of-view. For the work reported here we assembled a prototype SPECT camera system and acquired SPECT and MRI data from radioactive sources and resolution phantoms using the camera outside and inside the MRI. PMID:21966076

  15. [Gallium-67 myocardial imaging for the detection of adriamycin cardiomyopathy].

    PubMed

    Morozumi, T; Ishida, Y; Tani, A; Inui, M; Hori, M; Kitabatake, A; Kamada, T; Kondo, H; Kozuka, T; Kimura, K

    1990-05-01

    To detect Adriamycin cardiomyopathy, radionuclide myocardial imagings with Tl-201, Tc-99m pyrophosphate, I-123 metaiodobenzylguanidine and Ga-67 were performed in a 49 year-old-woman receiving Adriamycin (a total dose of 230 mg/m2) for the treatment of breast cancer. This patient demonstrated symptoms of congestive heart failure 2 months after the last intravenous administration. At the period of performing the radionuclide studies, echocardiographic LV ejection fraction (EF) was 22%. Despite severe deterioration of cardiac function, Tl-201 SPECT demonstrated no defect and Tc-99m pyrophosphate (PYP) SPECT demonstrated no positive finding. I-123 metaiodobenzylguanidine (MIBG) scintigraphy demonstrated no regional defect. However, I-123 MIBG washout rate during 4 hours was markedly enhanced, probably reflecting abnormalities of norepinephrine kinetics due to the progression of heart failure. Compared to these pharmaceuticals, Ga-67 was diffusely accumulated in the heart. Then, 5 months after the first study, when LV EF improved to 30% and congestive symptoms disappeared probably owing to beta-blockade therapy, myocardial accumulation of Ga-67 markedly reduced. It has been reported that Ga-67 accumulates in malignant tumor cells and leukocytes. Since, in Adriamycin cardiomyopathy, myocardial accumulation of leukocytes with myocardial fibrotic changes have been histologically demonstrated, the results of Ga-67 scintigraphy may reflect the accumulation of leukocytes. Thus, this case indicates that Ga-67 scintigraphy is advantageous for detecting Adriamycin cardiomyopathy and may be more useful than Tl-201 and Tc-99m PYP scintigraphies. PMID:2395231

  16. Systolic and diastolic assessment by 3D-ASM segmentation of gated-SPECT Studies: a comparison with MRI

    NASA Astrophysics Data System (ADS)

    Tobon-Gomez, C.; Bijnens, B. H.; Huguet, M.; Sukno, F.; Moragas, G.; Frangi, A. F.

    2009-02-01

    Gated single photon emission tomography (gSPECT) is a well-established technique used routinely in clinical practice. It can be employed to evaluate global left ventricular (LV) function of a patient. The purpose of this study is to assess LV systolic and diastolic function from gSPECT datasets in comparison with cardiac magnetic resonance imaging (CMR) measurements. This is achieved by applying our recently implemented 3D active shape model (3D-ASM) segmentation approach for gSPECT studies. This methodology allows for generation of 3D LV meshes for all cardiac phases, providing volume time curves and filling rate curves. Both systolic and diastolic functional parameters can be derived from these curves for an assessment of patient condition even at early stages of LV dysfunction. Agreement of functional parameters, with respect to CMR measurements, were analyzed by means of Bland-Altman plots. The analysis included subjects presenting either LV hypertrophy, dilation or myocardial infarction.

  17. Filtering in SPECT Image Reconstruction

    PubMed Central

    Lyra, Maria; Ploussi, Agapi

    2011-01-01

    Single photon emission computed tomography (SPECT) imaging is widely implemented in nuclear medicine as its clinical role in the diagnosis and management of several diseases is, many times, very helpful (e.g., myocardium perfusion imaging). The quality of SPECT images are degraded by several factors such as noise because of the limited number of counts, attenuation, or scatter of photons. Image filtering is necessary to compensate these effects and, therefore, to improve image quality. The goal of filtering in tomographic images is to suppress statistical noise and simultaneously to preserve spatial resolution and contrast. The aim of this work is to describe the most widely used filters in SPECT applications and how these affect the image quality. The choice of the filter type, the cut-off frequency and the order is a major problem in clinical routine. In many clinical cases, information for specific parameters is not provided, and findings cannot be extrapolated to other similar SPECT imaging applications. A literature review for the determination of the mostly used filters in cardiac, brain, bone, liver, kidneys, and thyroid applications is also presented. As resulting from the overview, no filter is perfect, and the selection of the proper filters, most of the times, is done empirically. The standardization of image-processing results may limit the filter types for each SPECT examination to certain few filters and some of their parameters. Standardization, also, helps in reducing image processing time, as the filters and their parameters must be standardised before being put to clinical use. Commercial reconstruction software selections lead to comparable results interdepartmentally. The manufacturers normally supply default filters/parameters, but these may not be relevant in various clinical situations. After proper standardisation, it is possible to use many suitable filters or one optimal filter. PMID:21760768

  18. New SPECT and PET Radiopharmaceuticals for Imaging Cardiovascular Disease

    PubMed Central

    Sogbein, Oyebola O.; Pelletier-Galarneau, Matthieu; Schindler, Thomas H.; Wei, Lihui; Wells, R. Glenn; Ruddy, Terrence D.

    2014-01-01

    Nuclear cardiology has experienced exponential growth within the past four decades with converging capacity to diagnose and influence management of a variety of cardiovascular diseases. Single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) with technetium-99m radiotracers or thallium-201 has dominated the field; however new hardware and software designs that optimize image quality with reduced radiation exposure are fuelling a resurgence of interest at the preclinical and clinical levels to expand beyond MPI. Other imaging modalities including positron emission tomography (PET) and magnetic resonance imaging (MRI) continue to emerge as powerful players with an expanded capacity to diagnose a variety of cardiac conditions. At the forefront of this resurgence is the development of novel target vectors based on an enhanced understanding of the underlying pathophysiological process in the subcellular domain. Molecular imaging with novel radiopharmaceuticals engineered to target a specific subcellular process has the capacity to improve diagnostic accuracy and deliver enhanced prognostic information to alter management. This paper, while not comprehensive, will review the recent advancements in radiotracer development for SPECT and PET MPI, autonomic dysfunction, apoptosis, atherosclerotic plaques, metabolism, and viability. The relevant radiochemistry and preclinical and clinical development in addition to molecular imaging with emerging modalities such as cardiac MRI and PET-MR will be discussed. PMID:24901002

  19. [Marked 99mTc-PYP myocardial accumulation immediately after reperfusion in a patient with acute myocardial infarction].

    PubMed

    Adachi, Yoshihiko; Ito, Kazuki; Nishikawa, Susumu; Yuba, Tatsuya; Tsubakimoto, Yoshinori; Takata, Hiroki; Kato, Shuji; Azuma, Akihiro; Sugihara, Hiroki; Nakagawa, Masao

    2003-02-01

    We reported a case of a 72-year-old man with chest pain. An electrocardiogram showed ST segment elevation in I, II, III, aVL, aVF and V1-6 leads. 99mTc-tetrofosmin myocardial SPECT showed defect in the anterior, septal, apical and inferior walls. Coronary angiography showed 99% stenosis of the proximal right coronary artery and total occlusion of the midsegment of the left anterior descending coronary artery. Therefore, direct PTCA was performed for each lesion to achieve reperfusion. We didnt's see reperfusion injury during PTCA of the left coronary artery. On the other side, we saw severe reperfusion injury, such as slow-flow, arrhythmia and falling blood pressure during PTCA of the right coronary artery. After four hours, 99mTc-PYP myocardial SPECT showed marked uptake in the apical and inferior walls, and mild uptake in the anterior and posterior walls. After three days, severely-reduced uptake of 99mTc-PYP in the apex was noted, and mild uptake in the mid-portion of the anterior wall and the mid-portion of the inferior wall. Though reperfusion injury was seen, three was mild myocardial uptake of 99mTc-PYP in the area of the right coronary artery. On the other side, despite no reperfusion injury, there showed marked uptake during the acute phase and defect during the subacute phase in the area of the left coronary artery. Wall motion of the left ventricle was normal in the area of the right coronary artery and akinesis was seen on the left. These findings suggest that 99mTc-tetrofosmin and 99mTc-PYP myocardial SPECT are useful for visualization of reperfusion injury during the acute phase and for estimation of function during the chronic phase, better even than electrocardiogram or coronary angiography. PMID:12701202

  20. Thymic tuberculosis preoperatively evaluated with thallium-201 SPECT: two resected cases.

    PubMed

    Iwata, Takashi; Inoue, Kiyotoshi; Mizuguchi, Shinjiro; Tsukioka, Takuma; Morita, Ryuhei; Suehiro, Shigefumi

    2007-02-01

    We present 2 resected cases of thymic tuberculosis, which had been preoperatively diagnosed as invasive thymoma, using a thallium-201 ((201)Tl) single photon emission computed tomography ((201)Tl SPECT). [Patient 1] A 74-old-male with a 32-year history of steroid therapy for rheumatic arthritis was diagnosed with an anterior mediastinal tumor by routine chest CT scans after onset of myocardial infarction. [Patient 2] A 56-old-female with a 28-year history of diabetes mellitus presented with a dry cough. A chest CT demonstrated an anterior mediastinal tumor. Neither patient showed pulmonary infiltrations on chest x-ray. (201)Tl SPECT was undertaken for each patient. Abnormal findings could not be detected on a planar image of the scintigraphy; however, on SPECT images accumulations of (201)Tl were clearly detected in the anterior mediastinal mass and a thymoma was thus suspected in each case. Total thymectomy was carried out in each case and the mass then diagnosed as caseous granuloma in the thymus. Both patients are well without recurrence after operation. In patients with a (201)Tl SPECT positive anterior mediastinal tumor associated with an immunologically deficient status, and with negative findings in planar images on thallium scintigraphy, the possibility of thymic tuberculosis should be considered. PMID:17392671

  1. Biomedical Imaging: SPECT and PET

    SciTech Connect

    Lecomte, Roger

    2007-11-26

    Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) are non-invasive nuclear imaging techniques relying on the use of tomographic reconstruction methods to provide 3D representations of the distribution of radiolabeled molecules in vivo. Differences in the underlying physical principles determine the achievable spatial resolution, sensitivity, specificity and observation time span of these two imaging modalities. Their specific characteristics are described and the current technology developments and design tradeoffs are reviewed.

  2. End-expiration respiratory gating for a high-resolution stationary cardiac SPECT system

    NASA Astrophysics Data System (ADS)

    Chan, Chung; Harris, Mark; Le, Max; Biondi, James; Grobshtein, Yariv; Liu, Yi-Hwa; Sinusas, Albert J.; Liu, Chi

    2014-10-01

    Respiratory and cardiac motions can degrade myocardial perfusion SPECT (MPS) image quality and reduce defect detection and quantitative accuracy. In this study, we developed a dual respiratory and cardiac gating system for a high-resolution fully stationary cardiac SPECT scanner in order to improve the image quality and defect detection. Respiratory motion was monitored using a compressive sensor pillow connected to a dual respiratory-cardiac gating box, which sends cardiac triggers only during end-expiration phases to the single cardiac trigger input on the SPECT scanners. The listmode data were rebinned retrospectively into end-expiration frames for respiratory motion reduction or eight cardiac gates only during end-expiration phases to compensate for both respiratory and cardiac motions. The proposed method was first validated on a motion phantom in the presence and absence of multiple perfusion defects, and then applied on 11 patient studies with and without perfusion defects. In the normal phantom studies, the end-expiration gated SPECT (EXG-SPECT) reduced respiratory motion blur and increased myocardium to blood pool contrast by 51.2% as compared to the ungated images. The proposed method also yielded an average of 11.2% increase in myocardium to defect contrast as compared to the ungated images in the phantom studies with perfusion defects. In the patient studies, EXG-SPECT significantly improved the myocardium to blood pool contrast (p < 0.005) by 24% on average as compared to the ungated images, and led to improved perfusion uniformity across segments on polar maps for normal patients. For a patient with defect, EXG-SPECT improved the defect contrast and definition. The dual respiratory-cardiac gating further reduced the blurring effect, increased the myocardium to blood pool contrast significantly by 36% (p < 0.05) compared to EXG-SPECT, and further improved defect characteristics and visualization of fine structures at the expense of increased noise on

  3. End-expiration Respiratory Gating for a High Resolution Stationary Cardiac SPECT system

    PubMed Central

    Chan, Chung; Harris, Mark; Le, Max; Biondi, James; Grobshtein, Yariv; Liu, Yi-Hwa; Sinusas, Albert J.; Liu, Chi

    2014-01-01

    Respiratory and cardiac motions can degrade myocardial perfusion SPECT (MPS) image quality and reduce defect detection and quantitative accuracy. In this study, we developed a dual-respiratory and cardiac gating system for a high resolution fully stationary cardiac SPECT scanner in order to improve the image quality and defect detection. Respiratory motion was monitored using a compressive sensor pillow connected to a dual respiratory-cardiac gating box, which sends cardiac triggers only during end-expiration phases to the single cardiac trigger input on the SPECT scanners. The listmode data were rebinned retrospectively into end-expiration frames for respiratory motion reduction or 8 cardiac gates only during end-expiration phases to compensate for both respiratory and cardiac motions. The proposed method was first validated on a motion phantom in the presence and absence of multiple perfusion defects, and then applied on 11 patient studies with and without perfusion defects. In the normal phantom studies, the end-expiration gated SPECT (EXG-SPECT) reduced respiratory motion blur and increased myocardium to blood pool contrast by 51.2% as compared to the ungated images. The proposed method also yielded an average of 11.2% increase in myocardium to defect contrast as compared to the ungated images in the phantom studies with perfusion defects. In the patient studies, EXG-SPECT significantly improved the myocardium to blood pool contrast (p<0.005) by 24% on average as compared to the ungated images, and led to improved perfusion uniformity across segments on polar maps for normal patients. For a patient with defect, EXG-SPECT improved the defect contrast and definition. The dual respiratory-cardiac gating further reduced the blurring effect, increased the myocardium to blood pool contrast significantly by 36% (p<0.05) compared to EXG SPECT, and further improved defect characteristics and visualization of fine structures at the expense of increased noise on the

  4. Organ volume estimation using SPECT

    SciTech Connect

    Zaidi, H.

    1996-06-01

    Knowledge of in vivo thyroid volume has both diagnostic and therapeutic importance and could lead to a more precise quantification of absolute activity contained in the thyroid gland. In order to improve single-photon emission computed tomography (SPECT) quantitation, attenuation correction was performed according to Chang`s algorithm. The dual window method was used for scatter subtraction. The author used a Monte Carlo simulation of the SPECT system to accurately determine the scatter multiplier factor k. Volume estimation using SPECT was performed by summing up the volume elements (voxels) lying within the contour of the object, determined by a fixed threshold and the gray level histogram (GLH) method. Thyroid phantom and patient studies were performed and the influence of (1) fixed thresholding, (2) automatic thresholding, (3) attenuation, (4) scatter, and (5) reconstruction filter were investigated. This study shows that accurate volume estimation of the thyroid gland is feasible when accurate corrections are performed. The relative error is within 7% for the GLH method combined with attenuation and scatter corrections.

  5. Effective dose to patients and staff when using a mobile PET/SPECT system.

    PubMed

    Studenski, Matthew T

    2013-01-01

    The purpose of this study was to determine the number of weekly acquisitions permissible using a mobile PET/SPECT scanner for myocardial perfusion/viability imaging in an intensive care unit (ICU) based on the effective dose to patients and staff. The effective dose to other patients and staff in an ICU was calculated following recommendations from the American Association of Physicists in Medicine Task Group 108 report (AAPM TG-108). The number of weekly acquisitions using 555 MBq (15 mCi) Tc-99m for myocardial perfusion or F-18 for myocardial viability was determined using the regulatory limits described in the Code of Federal Regulations 10 CFR 20. To increase the number of weekly acquisitions allowed, a reduction in administered dose and portable shielding was considered. A single myocardial perfusion image can be acquired with Tc-99m each week with a dose reduction to 455 MBq (12.3 mCi) without additional shielding. To acquire a myocardial viability image with F-18, an activity reduction to 220 MBq (5.9 mCi) is required to meet the regulatory effective dose limit without additional shielding. More than one weekly acquisition can be performed if additional shielding or activity reduction is utilized. A method for calculating dose to patients and staff in an ICU has been developed using conservative assumptions and following AAPM TG-108. This calculation must be repeated for each individual clinic before any acquisition is performed. PMID:23652256

  6. Association between heart rate at rest and myocardial perfusion in patients with acute myocardial infarction undergoing cardiac rehabilitation – a pilot study

    PubMed Central

    Uematsu, Mariko; Ashikaga, Kohei; Yoneyama, Kihei; Kida, Keisuke; Suzuki, Kengo; Omiya, Kazuto; Harada, Tomoo; Banach, Maciej; Miyake, Fumihiko

    2012-01-01

    Introduction This study was conducted to determine if there was a link among heart rate at rest (rHR), muscle volume changes, and single photon emission computed tomography (SPECT) parameters after 6-month cardiac rehabilitation in patients with acute myocardial infarction (AMI). Material and methods Twenty-nine consecutive AMI patients (mean age: 63.0 ±9.1 years) who received appropriate percutaneous coronary intervention on admission were enrolled. 99mTc-Sestamibi myocardial SPECT images were obtained at the early (30 min) and delayed (4 h) phases after tracer injection at 2 weeks (0M) and 6 months (6M) after the onset of AMI. Within a few days of SPECT, all patients underwent cardiopulmonary exercise test for evaluation of cardiac rehabilitation effects. Before the initiation of exercise test, leg muscle volume was measured. All patients were stratified into the ≥ 70 beats per minute (bpm) (n = 15) or < 70 bpm (n = 14) group based on rHR at 6M. Results There were no significant differences in the recanalization time, peak cardiac enzyme, or initial left ventricular ejection fraction between the two groups. After the 6-month training, the muscle volume changes in the lower limbs (< 70 bpm, 0.23 ±0.22; ≥ 70 bpm, –0.07 ±0.26, p < 0.05) were significantly greater in the < 70 bpm group than the ≥ 70 bpm group. The decreased rate of rHR had a significant correlation with the improved global severity (r = 0.62, p = 0.001) and extent (r = 0.48, p = 0.017) of left ventricle evaluated by 99mTc-Sestamibi myocardial SPECT delayed phase. Conclusions The result of this preliminary study demonstrated that improved myocardial perfusion was closely related to decreased rHR after cardiac rehabilitation. PMID:23056072

  7. Ectopic expression of the sodium-iodide symporter enables imaging of transplanted cardiac stem cells in vivo by SPECT or PET

    PubMed Central

    Terrovitis, John; Kwok, Keng Fai; Lautamäki, Riikka; Engles, James M; Barth, Andreas S; Kizana, Eddy; Miake, Junichiro; Leppo, Michelle K; Fox, James; Seidel, Jurgen; Pomper, Martin; Wahl, Richard L; Tsui, Benjamin; Bengel, Frank; Marbán, Eduardo; Abraham, M. Roselle

    2015-01-01

    Objectives We examined the sodium-iodide symporter (NIS) which promotes in vivo cellular uptake of 99mTc or 124I, as a reporter gene for cell tracking by SPECT or PET imaging. Background Stem cells offer the promise of cardiac repair. Stem cell labeling is a prerequisite to tracking cell fate in vivo. Methods The human NIS cDNA was transduced into rat cardiac-derived stem cells (rCDCs) using lentiviral vectors. Rats were injected intra-myocardially with up to 4 million NIS+-rCDCs immediately following LAD ligation. Dual isotope SPECT (or PET) imaging was performed, using 99mTc (or 124I) for cell detection and 201Tl (or 13NH3) for myocardial delineation. In a subset of animals, high resolution ex vivo SPECT scans of explanted hearts were obtained to confirm that in vivo signals were derived from the cell injection site. Results NIS expression in rCDCs did not affect cell viability and proliferation. NIS activity was verified in isolated transduced cells by measuring 99mTc uptake. NIS+ rCDCs were visualized in vivo as regions of 99mTc or 124I uptake within a perfusion deficit in the SPECT and PET images, respectively. Cells could be visualized by SPECT up to day 6 post-injection. Ex vivo SPECT confirmed that in vivo 99mTc signals were localized to the cell injection sites. Conclusion Ectopic NIS expression allows non invasive in vivo stem cell tracking in the myocardium, using either SPECT or PET. The general approach shows significant promise in tracking the fate of transplanted cells participating in cardiac regeneration, given its ability to observe living cells using clinically-applicable imaging modalities. PMID:18992656

  8. SPECT/CT and pulmonary embolism.

    PubMed

    Mortensen, Jann; Gutte, Henrik

    2014-05-01

    Acute pulmonary embolism (PE) is diagnosed either by ventilation/perfusion (V/P) scintigraphy or pulmonary CT angiography (CTPA). In recent years both techniques have improved. Many nuclear medicine centres have adopted the single photon emission CT (SPECT) technique as opposed to the planar technique for diagnosing PE. SPECT has been shown to have fewer indeterminate results and a higher diagnostic value. The latest improvement is the combination of a low-dose CT scan with a V/P SPECT scan in a hybrid tomograph. In a study comparing CTPA, planar scintigraphy and SPECT alone, SPECT/CT had the best diagnostic accuracy for PE. In addition, recent developments in the CTPA technique have made it possible to image the pulmonary arteries of the lungs in one breath-hold. This development is based on the change from a single-detector to multidetector CT technology with an increase in volume coverage per rotation and faster rotation. Furthermore, the dual energy CT technique is a promising modality that can provide functional imaging in combination with anatomical information. Newer high-end CT scanners and SPECT systems are able to visualize smaller subsegmental emboli. However, consensus is lacking regarding the clinical impact and treatment. In the present review, SPECT and SPECT in combination with low-dose CT, CTPA and dual energy CT are discussed in the context of diagnosing PE. PMID:24213621

  9. Normal values for nuclear cardiology: Japanese databases for myocardial perfusion, fatty acid and sympathetic imaging and left ventricular function.

    PubMed

    Nakajima, Kenichi

    2010-04-01

    Myocardial normal databases for stress myocardial perfusion study have been created by the Japanese Society of Nuclear Medicine Working Group. The databases comprised gender-, camera rotation range- and radiopharmaceutical-specific data-sets from multiple institutions, and normal database files were created for installation in common nuclear cardiology software. Based on the electrocardiography-gated single-photon emission computed tomography (SPECT), left ventricular function, including ventricular volumes, systolic and diastolic functions and systolic wall thickening were also analyzed. Normal databases for fatty acid imaging using (123)I-beta-methyl-iodophenyl-pentadecanoic acid and sympathetic imaging using (123)I-meta-iodobenzylguanidine were also examined. This review provides lists and overviews of normal values for myocardial SPECT and ventricular function in a Japanese population. The population-specific approach is a key factor for proper diagnostic and prognostic evaluation. PMID:20108130

  10. Normal values for nuclear cardiology: Japanese databases for myocardial perfusion, fatty acid and sympathetic imaging and left ventricular function

    PubMed Central

    2010-01-01

    Myocardial normal databases for stress myocardial perfusion study have been created by the Japanese Society of Nuclear Medicine Working Group. The databases comprised gender-, camera rotation range- and radiopharmaceutical-specific data-sets from multiple institutions, and normal database files were created for installation in common nuclear cardiology software. Based on the electrocardiography-gated single-photon emission computed tomography (SPECT), left ventricular function, including ventricular volumes, systolic and diastolic functions and systolic wall thickening were also analyzed. Normal databases for fatty acid imaging using 123I-beta-methyl-iodophenyl-pentadecanoic acid and sympathetic imaging using 123I-meta-iodobenzylguanidine were also examined. This review provides lists and overviews of normal values for myocardial SPECT and ventricular function in a Japanese population. The population-specific approach is a key factor for proper diagnostic and prognostic evaluation. PMID:20108130

  11. Myocardial imaging. Coxsackie myocarditis

    SciTech Connect

    Wells, R.G.; Ruskin, J.A.; Sty, J.R.

    1986-09-01

    A 3-week-old male neonate with heart failure associated with Coxsackie virus infection was imaged with Tc-99m PYP and TI-201. The abnormal imaging pattern suggested myocardial infarction. Autopsy findings indicated that the cause was myocardial necrosis secondary to an acute inflammatory process. Causes of abnormal myocardial uptake of Tc-99m PYP in pediatrics include infarction, myocarditis, cardiomyopathy, bacterial endocarditis, and trauma. Myocardial imaging cannot provide a specific cause diagnosis. Causes of myocardial infarction in pediatrics are listed in Table 1.

  12. Imaging of acute myocardial infarction in pigs with Indium-111 monoclonal antimyosin scintigraphy and MRI

    SciTech Connect

    ten Kate, C.I.; van Kroonenburgh, M.J.; Schipperheyn, J.J.; Doornbos, J.; Hoedemaeker, P.J.; Maes, A.; v.d. Nat, K.H.; Camps, J.A.; Huysmans, H.A.; Pauwels, E.K. )

    1990-07-01

    Indium-111 antimyosin F(ab')2 was used in a series of scintigraphic studies on experimentally induced myocardial infarctions in pigs. Antimyosin distribution recorded by planar images of in vivo pigs and by single photon emission computed tomography (SPECT) of excised hearts delineated areas of myocardial necrosis if infarct volume exceeded 3.3 cm3. Scintigraphic images were compared with magnetic resonance images (MRI) obtained from excised hearts and with photographs of slices of the hearts. Infarct size and localization determined with antimyosin were compared. The MR images, with or without gadolinium-DTPA (Gd-DTPA), of the in vivo pigs were all false-negative; some myocardial wall thinning and high bloodpool signals were visible. Results show that both the antimyosin and the MR technique are specific methods for the visualization of induced myocardial necrosis in this animal model. However, the use of antimyosin is limited to a period ranging from 24 to 72 hours after infarction.

  13. [Diagnostic utility of 111In-antimyosin Fab scintigraphy in acute myocardial infarction: comparison with 201Tl and 99mTc-pyrophosphate myocardial scintigraphy].

    PubMed

    Morita, M; Naruse, H; Yamamoto, J; Itano, M; Kawamoto, H; Fukutake, N; Ohyanagi, M; Iwasaki, T; Fukuchi, M

    1991-12-01

    To assess the diagnostic accuracy, extent, and characteristics of 111In-antimyosin Fab scintigraphy (In-AM) in acute myocardial infarction (AMI), we studied In-AM in 17 patients with AMI and compared with In-AM, 99mTc-PYP and 201Tl scintigraphy. Intensity of In-AM uptake was classified into 3 grades. Fourteen of 17 patients (82%) showed positive uptake of In-AM. The locations of infarct area diagnosed by In-AM were in accordance with those by electrocardiography. There was a good correlation between the extent score of In-AM planar and that of SPECT (r = 0.72), In-AM SPECT and Tl SPECT (r = 0.79), In-AM planar and PYP planar (r = 0.92), In-AM SPECT and PYP SPECT (r = 0.76), respectively (p less than 0.01). Thus, In-AM is a useful method for diagnosis of AMI. PMID:1838398

  14. High-Efficiency SPECT MPI: Comparison of Automated Quantification, Visual Interpretation, and Coronary Angiography

    PubMed Central

    Duvall, W. Lane; Slomka, Piotr J.; Gerlach, Jim R.; Sweeny, Joseph M.; Baber, Usman; Croft, Lori B.; Guma, Krista A.; George, Titus; Henzlova, Milena J.

    2013-01-01

    Background Recently introduced high-efficiency (HE) SPECT cameras with solid-state CZT detectors have been shown to decrease imaging time and reduce radiation exposure to patients. An automated, computer derived quantification of HE MPI has been shown to correlate well with coronary angiography on one HE SPECT camera system (D-SPECT), but has not been compared to visual interpretation on any of the HE SPECT platforms. Methods Patients undergoing a clinically indicated Tc-99m sestamibi HE SPECT (GE Discovery 530c with supine and prone imaging) study over a one year period followed by a coronary angiogram within 2 months were included. Only patients with a history of CABG surgery were excluded. Both MPI studies and coronary angiograms were reinterpreted by blinded readers. One hundred and twenty two very low (risk of CAD < 5%) or low (risk of CAD < 10%) likelihood subjects with normal myocardial perfusion were used to create normal reference limits. Computer derived quantification of the total perfusion deficit (TPD) at stress and rest was obtained with QPS software. The visual and automated MPI quantification were compared to coronary angiography (≥ 70% luminal stenosis) by receiver operating curve (ROC) analysis. Results Of the 3,111 patients who underwent HE SPECT over a one year period, 160 patients qualified for the correlation study (66% male, 52% with a history of CAD). The ROC area under the curve (AUC) was similar for both the automated and visual interpretations using both supine only and combined supine and prone images (0.69-0.74). Using thresholds determined from sensitivity and specificity curves, the automated reads showed higher specificity (59-67% versus 27-60%) and lower sensitivity (71-72% versus 79-93%) than the visual reads. By including prone images sensitivity decreased slightly but specificity increased for both. By excluding patients with known CAD and cardiomyopathies, AUC and specificity increased for both techniques (0.72-0.82). The use

  15. Investigation of optimal acquisition time of myocardial perfusion scintigraphy using cardiac focusing-collimator

    NASA Astrophysics Data System (ADS)

    Niwa, Arisa; Abe, Shinji; Fujita, Naotoshi; Kono, Hidetaka; Odagawa, Tetsuro; Fujita, Yusuke; Tsuchiya, Saki; Kato, Katsuhiko

    2015-03-01

    Recently myocardial perfusion SPECT imaging acquired using the cardiac focusing-collimator (CF) has been developed in the field of nuclear cardiology. Previously we have investigated the basic characteristics of CF using physical phantoms. This study was aimed at determining the acquisition time for CF that enables to acquire the SPECT images equivalent to those acquired by the conventional method in 201TlCl myocardial perfusion SPECT. In this study, Siemens Symbia T6 was used by setting the torso phantom equipped with the cardiac, pulmonary, and hepatic components. 201TlCl solution were filled in the left ventricular (LV) myocardium and liver. Each of CF, the low energy high resolution collimator (LEHR), and the low medium energy general purpose collimator (LMEGP) was set on the SPECT equipment. Data acquisitions were made by regarding the center of the phantom as the center of the heart in CF at various acquisition times. Acquired data were reconstructed, and the polar maps were created from the reconstructed images. Coefficient of variation (CV) was calculated as the mean counts determined on the polar maps with their standard deviations. When CF was used, CV was lower at longer acquisition times. CV calculated from the polar maps acquired using CF at 2.83 min of acquisition time was equivalent to CV calculated from those acquired using LEHR in a 180°acquisition range at 20 min of acquisition time.

  16. The AdaptiSPECT Imaging Aperture

    PubMed Central

    Chaix, Cécile; Moore, Jared W.; Van Holen, Roel; Barrett, Harrison H.; Furenlid, Lars R.

    2015-01-01

    In this paper, we present the imaging aperture of an adaptive SPECT imaging system being developed at the Center for Gamma Ray Imaging (AdaptiSPECT). AdaptiSPECT is designed to automatically change its configuration in response to preliminary data, in order to improve image quality for a particular task. In a traditional pinhole SPECT imaging system, the characteristics (magnification, resolution, field of view) are set by the geometry of the system, and any modification can be accomplished only by manually changing the collimator and the distance of the detector to the center of the field of view. Optimization of the imaging system for a specific task on a specific individual is therefore difficult. In an adaptive SPECT imaging system, on the other hand, the configuration can be conveniently changed under computer control. A key component of an adaptive SPECT system is its aperture. In this paper, we present the design, specifications, and fabrication of the adaptive pinhole aperture that will be used for AdaptiSPECT, as well as the controls that enable autonomous adaptation. PMID:27019577

  17. SPECT functional brain imaging. Technical considerations.

    PubMed

    Devous, M D

    1995-07-01

    The technical aspects of functional brain single-photon emission computed tomography (SPECT) imaging, referring primarily to the most common SPECT brain function measure--regional cerebral blood flow--are reviewed. SPECT images of regional cerebral blood flow are influenced by a number of factors unrelated to pathology, including tomographic quality, radiopharmaceuticals, environmental conditions at the time of radiotracer administration, characteristics of the subject (e.g., age, sex), image presentation, and image processing techniques. Modern SPECT scans yield excellent image quality, and instrumentation continues to improve. The armamentarium of regional cerebral blood flow and receptor radiopharmaceuticals is rapidly expanding. Standards regarding the environment for patient imaging and image presentation are emerging. However, there is still much to learn about the circumstances for performances and evaluation of SPECT functional brain imaging. Challenge tests, primarily established in cerebrovascular disease (i.e., the acetazolamide test), offer great promise in defining the extent and nature of disease, as well as predicting therapeutic responses. Clearly, SPECT brain imaging is a powerful clinical and research tool. However, SPECT will only achieve its full potential in the management of patients with cerebral pathology through close cooperation among members of the nuclear medicine, neurology, psychiatry, neurosurgery, and internal medicine specialties. PMID:7626833

  18. Integration of AdaptiSPECT, a small-animal adaptive SPECT imaging system

    PubMed Central

    Chaix, Cécile; Kovalsky, Stephen; Kosmider, Matthew; Barrett, Harrison H.; Furenlid, Lars R.

    2015-01-01

    AdaptiSPECT is a pre-clinical adaptive SPECT imaging system under final development at the Center for Gamma-ray Imaging. The system incorporates multiple adaptive features: an adaptive aperture, 16 detectors mounted on translational stages, and the ability to switch between a non-multiplexed and a multiplexed imaging configuration. In this paper, we review the design of AdaptiSPECT and its adaptive features. We then describe the on-going integration of the imaging system. PMID:26347197

  19. SPECT Imaging: Basics and New Trends

    NASA Astrophysics Data System (ADS)

    Hutton, Brian F.

    Single Photon Emission Computed Tomography (SPECT) is widely used as a means of imaging the distribution of administered radiotracers that have single-photon emission. The most widely used SPECT systems are based on the Anger gamma camera, usually involving dual detectors that rotate around the patient. Several factors affect the quality of SPECT images (e.g., resolution and noise) and the ability to perform absolute quantification (e.g., attenuation, scatter, motion, and resolution). There is a trend to introduce dual-modality systems and organ-specific systems, both developments that enhance diagnostic capability.

  20. Quantitative SPECT/CT: SPECT joins PET as a quantitative imaging modality.

    PubMed

    Bailey, Dale L; Willowson, Kathy P

    2014-05-01

    The introduction of combined modality single photon emission computed tomography (SPECT)/CT cameras has revived interest in quantitative SPECT. Schemes to mitigate the deleterious effects of photon attenuation and scattering in SPECT imaging have been developed over the last 30 years but have been held back by lack of ready access to data concerning the density of the body and photon transport, which we see as key to producing quantitative data. With X-ray CT data now routinely available, validations of techniques to produce quantitative SPECT reconstructions have been undertaken. While still suffering from inferior spatial resolution and sensitivity compared to positron emission tomography (PET) imaging, SPECT scans nevertheless can be produced that are as quantitative as PET scans. Routine corrections are applied for photon attenuation and scattering, resolution recovery, instrumental dead time, radioactive decay and cross-calibration to produce SPECT images in units of kBq.ml(-1). Though clinical applications of quantitative SPECT imaging are lacking due to the previous non-availability of accurately calibrated SPECT reconstructions, these are beginning to emerge as the community and industry focus on producing SPECT/CT systems that are intrinsically quantitative. PMID:24037503

  1. Idiopathic calcified myocardial mass

    PubMed Central

    Patterson, David; Gibson, Derek; Gomes, Ricardo; McDonald, Lawson; Olsen, Eckhardt; Parker, John; Ross, Donald

    1974-01-01

    Patterson, D., Gibson, D., Gomes, R., McDonald, L., Olsen, E., Parker, J., and Ross, D. (1974).Thorax,29, 589-594. Idiopathic calcified myocardial mass. Myocardial calcification can be subdivided into three groups—metastatic, dystrophic or an extension inwards from the pericardium. This case in which the calcified myocardial mass was initially delineated by radiography and by echocardiography and subsequently removed does not fit into any subdivision and has been termed idiopathic. Images PMID:4279467

  2. The effect of acquisition interval and spatial resolution on dynamic cardiac imaging with a stationary SPECT camera.

    PubMed

    Roberts, J; Maddula, R; Clackdoyle, R; DiBella, E; Fu, Z

    2007-08-01

    The current SPECT scanning paradigm that acquires images by slow rotation of multiple detectors in body-contoured orbits around the patient is not suited to the rapid collection of tomographically complete data. During rapid image acquisition, mechanical and patient safety constraints limit the detector orbit to circular paths at increased distances from the patient, resulting in decreased spatial resolution. We consider a novel dynamic rotating slant-hole (DyRoSH) SPECT camera that can collect full tomographic data every 2 s, employing three stationary detectors mounted with slant-hole collimators that rotate at 30 rpm. Because the detectors are stationary, they can be placed much closer to the patient than is possible with conventional SPECT systems. We propose that the decoupling of the detector position from the mechanics of rapid image acquisition offers an additional degree of freedom which can be used to improve accuracy in measured kinetic parameter estimates. With simulations and list-mode reconstructions, we consider the effects of different acquisition intervals on dynamic cardiac imaging, comparing a conventional three detector SPECT system with the proposed DyRoSH SPECT system. Kinetic parameters of a two-compartment model of myocardial perfusion for technetium-99m-teboroxime were estimated. When compared to a conventional SPECT scanner for the same acquisition periods, the proposed DyRoSH system shows equivalent or reduced bias or standard deviation values for the kinetic parameter estimates. The DyRoSH camera with a 2 s acquisition period does not show any improvement compared to a DyRoSH camera with a 10 s acquisition period. PMID:17634648

  3. [Myocardial responses to ischemia].

    PubMed

    Borisenko, V G; Gubareva, E A; Kade, A Kh

    2010-01-01

    The paper details the types of a myocardial response to impaired blood flow, such as myocardial stunning, hibernation, ischemic preconditioning, warm-up phenomenon, ischemic postconditioning, remodeling, and infarction. According to the pathogenesis, the authors identify several types of myocardial dysfunction in transient ischemic attack--uptake, delivery; and a mixed one. It is concluded the myocardial response to damage depends on a combination of influencing factors, a number of pathophysiological processes starting in the acute phase of ischemia achieve its peak in the late period. PMID:20564927

  4. Prognostic Utility of Calcium Scoring as an Adjunct to Stress Myocardial Perfusion Scintigraphy in End-Stage Renal Disease

    PubMed Central

    Moody, William E.; Lin, Erica L.S.; Stoodley, Matthew; McNulty, David; Thomson, Louise E.; Berman, Daniel S.; Edwards, Nicola C.; Holloway, Benjamin; Ferro, Charles J.; Townend, Jonathan N.; Steeds, Richard P.

    2016-01-01

    Coronary artery calcium score (CACS) is a strong predictor of adverse cardiovascular events in the general population. Recent data confirm the prognostic utility of single-photon emission computed tomographic (SPECT) imaging in end-stage renal disease, but whether performing CACS as part of hybrid imaging improves risk prediction in this population is unclear. Consecutive patients (n = 284) were identified after referral to a university hospital for cardiovascular risk stratification in assessment for renal transplantation. Participants underwent technetium-99m SPECT imaging after exercise or standard adenosine stress in those unable to achieve 85% maximal heart rate; multislice CACS was also performed (Siemens Symbia T16, Siemens, Erlangen, Germany). Subjects with known coronary artery disease (n = 88) and those who underwent early revascularization (n = 2) were excluded. The primary outcome was a composite of death or first myocardial infarction. An abnormal SPECT perfusion result was seen in 22% (43 of 194) of subjects, whereas 45% (87 of 194) had at least moderate CACS (>100 U). The frequency of abnormal perfusion (summed stress score ≥4) increased with increasing CACS severity (p = 0.049). There were a total of 15 events (8 deaths, and 7 myocardial infarctions) after a median duration of 18 months (maximum follow-up 3.4 years). Univariate analysis showed diabetes mellitus (Hazard ratio [HR] 3.30, 95% CI 1.14 to 9.54; p = 0.028), abnormal perfusion on SPECT (HR 5.32, 95% CI 1.84 to 15.35; p = 0.002), and moderate-to-severe CACS (HR 3.55, 95% CI 1.11 to 11.35; p = 0.032) were all associated with the primary outcome. In a multivariate model, abnormal perfusion on SPECT (HR 4.18, 95% CI 1.43 to 12.27; p = 0.009), but not moderate-to-severe CACS (HR 2.50, 95% CI 0.76 to 8.20; p = 0.130), independently predicted all-cause death or myocardial infarction. The prognostic value of CACS was not incremental to clinical and SPECT perfusion data (global chi

  5. Prognostic Utility of Calcium Scoring as an Adjunct to Stress Myocardial Perfusion Scintigraphy in End-Stage Renal Disease.

    PubMed

    Moody, William E; Lin, Erica L S; Stoodley, Matthew; McNulty, David; Thomson, Louise E; Berman, Daniel S; Edwards, Nicola C; Holloway, Benjamin; Ferro, Charles J; Townend, Jonathan N; Steeds, Richard P

    2016-05-01

    Coronary artery calcium score (CACS) is a strong predictor of adverse cardiovascular events in the general population. Recent data confirm the prognostic utility of single-photon emission computed tomographic (SPECT) imaging in end-stage renal disease, but whether performing CACS as part of hybrid imaging improves risk prediction in this population is unclear. Consecutive patients (n = 284) were identified after referral to a university hospital for cardiovascular risk stratification in assessment for renal transplantation. Participants underwent technetium-99m SPECT imaging after exercise or standard adenosine stress in those unable to achieve 85% maximal heart rate; multislice CACS was also performed (Siemens Symbia T16, Siemens, Erlangen, Germany). Subjects with known coronary artery disease (n = 88) and those who underwent early revascularization (n = 2) were excluded. The primary outcome was a composite of death or first myocardial infarction. An abnormal SPECT perfusion result was seen in 22% (43 of 194) of subjects, whereas 45% (87 of 194) had at least moderate CACS (>100 U). The frequency of abnormal perfusion (summed stress score ≥4) increased with increasing CACS severity (p = 0.049). There were a total of 15 events (8 deaths, and 7 myocardial infarctions) after a median duration of 18 months (maximum follow-up 3.4 years). Univariate analysis showed diabetes mellitus (Hazard ratio [HR] 3.30, 95% CI 1.14 to 9.54; p = 0.028), abnormal perfusion on SPECT (HR 5.32, 95% CI 1.84 to 15.35; p = 0.002), and moderate-to-severe CACS (HR 3.55, 95% CI 1.11 to 11.35; p = 0.032) were all associated with the primary outcome. In a multivariate model, abnormal perfusion on SPECT (HR 4.18, 95% CI 1.43 to 12.27; p = 0.009), but not moderate-to-severe CACS (HR 2.50, 95% CI 0.76 to 8.20; p = 0.130), independently predicted all-cause death or myocardial infarction. The prognostic value of CACS was not incremental to clinical and SPECT perfusion data (global chi-square change

  6. Cardiac SPECT/CCTA hybrid imaging : One answer to two questions?

    PubMed

    Kaufmann, P A; Buechel, R R

    2016-08-01

    Noninvasive cardiac imaging has witnessed tremendous advances in the recent past, particularly with regard to coronary computed tomography angiography (CCTA) where substantial improvements in image quality have been achieved while at the same time patients' radiation dose exposure has been reduced to the sub-millisievert range. Similarly, for single-photon emission computed tomography (SPECT) the introduction of novel cadmium-zinc-telluride-based semiconductor detectors has significantly improved system sensitivity and image quality, enabling fast image acquisition within less than 2-3 min or reduction of radiation dose exposure to less than 5 mSv. However, neither imaging modality alone is able to fully cover the two aspects of coronary artery disease (CAD), that is, morphology and function. Both modalities have distinct advantages and shortcomings: While CCTA may prove a superb modality for excluding CAD through its excellent negative predictive value, it does not allow for assessment of hemodynamic relevance if obstructive coronary lesions are detected. Conversely, SPECT myocardial perfusion imaging cannot provide any information on the presence or absence of subclinical coronary atherosclerosis. This article aims to highlight the great potential of cardiac hybrid imaging that allows for a comprehensive evaluation of CAD through combination of both morphological and functional information by fusing SPECT with CCTA. PMID:27286848

  7. Postoperative myocardial infarction documented by technetium pyrophosphate scan using single-photon emission computed tomography: Significance of intraoperative myocardial ischemia and hemodynamic control

    SciTech Connect

    Cheng, D.C.; Chung, F.; Burns, R.J.; Houston, P.L.; Feindel, C.M. )

    1989-12-01

    The aim of this prospective study was to document postoperative myocardial infarction (PMI) by technetium pyrophosphate scan using single-photon emission computed tomography (TcPPi-SPECT) in 28 patients undergoing elective coronary bypass grafting (CABG). The relationships of intraoperative electrocardiographic myocardial ischemia, hemodynamic responses, and pharmacological requirements to this incidence of PMI were correlated. Radionuclide cardioangiography and TcPPi-SPECT were performed 24 h preoperatively and 48 h postoperatively. A standard high-dose fentanyl anesthetic protocol was used. Twenty-five percent of elective CABG patients were complicated with PMI, as documented by TcPPi-SPECT with an infarcted mass of 38.0 +/- 5.5 g. No significant difference in demographic, preoperative right and left ventricular function, number of coronary vessels grafted, or aortic cross-clamp time was observed between the PMI and non-PMI groups. The distribution of patients using preoperative beta-adrenergic blocking drugs or calcium channel blocking drugs was found to have no correlation with the outcome of PMI. As well, no significant differences in hemodynamic changes or pharmacological requirements were observed in the PMI and non-PMI groups during prebypass or postbypass periods, indicating careful intraoperative control of hemodynamic indices did not prevent the outcome of PMI in these patients. However, the incidence of prebypass ischemia was 39.3% and significantly correlated with the outcome of positive TcPPi-SPECT, denoting a 3.9-fold increased risk of developing PMI. Prebypass ischemic changes in leads II and V5 were shown to correlate with increased CPK-MB release (P less than 0.05) and tends to occur more frequently with lateral myocardial infarction.

  8. Dynamics of intramyocardial blood volume in the intact animal: evaluation with SPECT

    NASA Astrophysics Data System (ADS)

    Behrenbeck, Thomas; O'Connor, Michael K.; Foley, David A.; Ritman, Erik L.

    1996-04-01

    Variations in blood volume in the myocardium through the cardiac cycle have previously been considered constant. More recent studies have indicated a considerably variation from end diastole to end systole. These studies were nearly all performed under non-physiological conditions using muscle preparations or ex situ cardiac preparations. This study was designed to assess the dynamic changes of the intramyocardial blood volume in the intact animal under normal flow conditions using single photon emission computed tomography (SPECT). Radiolabeled, 15 micrometers diameter, microspheres were emoblized in the myocardial microcirculation of dogs with subsequent scans in a TRIAD single-photon-emission-computed- tomography scanner. Gated images were obtained at 63 msec intervals encompassing the entire heart. Transmural voxel (equals volume element) brightness was measured in all tomographic images reflecting global and regional count density in the myocardium. There was a significant decrease in the blood volume from end diastole to end systole (10.8 cc/100 mL muscle volume; p < 0.00001). The decrease from diastole (ED) to systole (ES) in image brightness at the apex, mid ventricle, and base were: -5.7% (p < 0.01, apex vs. base), -4.7% (p < 0.01, mid ventricle vs. base) and +2.2%, respectively. Conclusions: (1) respiratory and ECG gated SPECT images allow measurement of intramyocardial blood volume changes throughout the cardiac cycle in the intact animal; (2) myocardial blood content is maximum at ED; (3) these findings progressively diminished in magnitude from apex to base.

  9. SPECT assay of radiolabeled monoclonal antibodies

    SciTech Connect

    Jaszczak, R.J.

    1992-02-01

    The long-term goal of this research project is to develop methods to improve the utility of single photon emission computed tomography (SPECI) to quantify the biodistribution of monoclonal antibodies (MoAbs) labeled with clinically relevant radionuclides ({sup 123}I, {sup 131}I, and {sup 111}In) and with another radionuclide,{sup 211}At, recently used in therapy. We describe here our progress in developing quantitative SPECT methodology for {sup 111}In and {sup 123}I. We have focused our recent research thrusts on the following aspects of SPECT: (1) The development of improved SPECT hardware, such as improved acquisition geometries. (2) The development of better reconstruction methods that provide accurate compensation for the physical factors that affect SPECT quantification. (3) The application of carefully designed simulations and experiments to validate our hardware and software approaches.

  10. Awake animal SPECT: Overview and initial results

    SciTech Connect

    Weisenberger, A G; Majewski, S; McKisson, J; Popov, V; Proffitt, J; Stolin, A; Baba, J S; Goddard, J S; Lee, S J; Smith, M F; Tsui, B; Pomper, M

    2009-02-01

    A SPECT / X-ray CT system configured at Johns Hopkins University to image the biodistribution of radiopharmaceuticals in unrestrained, un-anesthetized mice has been constructed and tested on awake mice. The system was built by Thomas Jefferson National Accelerator Facility and Oak Ridge National Laboratory. SPECT imaging is accomplished using two gamma cameras, 10 cm × 20 cm in size based on a 2 × 4 array of Hamamatsu H8500 flat panel position sensitive photomultiplier tubes. A real-time optical tracking system utilizing three infrared cameras provides time stamped pose data of an awake mouse head during a SPECT scan. The six degrees of freedom (three translational and three rotational) pose data are used for motion correction during 3-D tomographic list-mode iterative image reconstruction. SPECT reconstruction of awake, unrestrained mice with motion compensation for head movement has been accomplished.

  11. Single Photon Emission Computed Tomography (SPECT)

    MedlinePlus

    ... High Blood Pressure Tools & Resources Stroke More Single Photon Emission Computed Tomography (SPECT) Updated:Sep 11,2015 ... Persantine) or dobutamine. The tests may take between 2 and 2 1/2 hours. What happens after ...

  12. Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block

    PubMed Central

    Cabeda, Estêvan Vieira; Falcão, Andréa Maria Gomes; Soares Jr., José; Rochitte, Carlos Eduardo; Nomura, César Higa; Ávila, Luiz Francisco Rodrigues; Parga, José Rodrigues

    2015-01-01

    Background Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB). Objective To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and compare the results with those of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy. Methods Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution’s ethics committee. Results The patients’ mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001). The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001). In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001). Conclusion The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB. PMID:26421532

  13. Cerebral SPECT imaging: Impact on clinical management

    SciTech Connect

    Bloom, M.; Jacobs, S.; Pozniakof, T.

    1994-05-01

    Although cerebral SPECT has been reported to be of value in a variety of neurologic disorders, there is limited data available on the value of SPECT relative to clinical management decisions. The purpose of this study was to determine the effect of cerebral SPECT imaging on patient management. A total of 94 consecutive patients referred for clinical evaluation with brain SPECT were included in this study. Patients were assigned to one of nine groups depending on the clinical indication for the study. These groups included transient ischemia (16), stroke (20), dementia (18), seizures (5), hemorrhage (13), head trauma (6), arteriovenous malformations (6), encephalopathy (6) and a miscellaneous (4) group. All patients were injected with 99mTc HMPAO in doses ranging from 15 mCi to 22 mCi (555 MBq to 814 MBq) and scanned on a triple headed SPECT gamma camera. Two weeks after completion of the study, a standardized interview was conducted between the nuclear and referring physicians to determine if the SPECT findings contributed to an alteration in patient management. Overall, patient management was significantly altered in 47% of the cases referred. The greatest impact on patient management occurred in the group evaluated for transient ischemia, where a total of 13/16 (81%) of patients had their clinical management altered as a result of the cerebral SPECT findings. Clinical management was altered in 61% of patients referred for evaluation of dementia, 67% of patients evaluated for arteriovenous malformations, and 50% of patients with head trauma. In the remainder of the patients, alteration in clinical management ranged from 17% to 50% of patients. This study demonstrates the clinical utility of cerebral SPECT imaging since in a significant number of cases clinical management was altered as a result of the examination. Long term follow up will be necessary to determine patient outcome.

  14. Brain SPECT quantitation in clinical diagnosis

    SciTech Connect

    Hellman, R.S.

    1991-12-31

    Methods to quantitate SPECT data for clinical diagnosis should be chosen so that they take advantage of the lessons learned from PET data. This is particularly important because current SPECT high-resolution brain imaging systems now produce images that are similar in resolution to those generated by the last generation PET equipment (9 mm FWHM). These high-resolution SPECT systems make quantitation of SPECT more problematic than earlier. Methodology validated on low-resolution SPECT systems may no longer be valid for data obtained with the newer SPECT systems. For example, in patients with dementia, the ratio of parietal to cerebellar activity often was studied. However, with new instruments, the cerebellum appears very different: discrete regions are more apparent. The large cerebellar regions usually used with older instrumentation are of an inappropriate size for the new equipment. The normal range for any method of quantitation determined using older equipment probably changes for data obtained with new equipment. It is not surprising that Kim et al. in their simulations demonstrated that because of the finite resolution of imaging systems, the ability to measure pure function is limited, with {open_quotes}anatomy{close_quotes} and {open_quotes}function{close_quotes} coupled in a {open_quotes}complex nonlinear way{close_quotes}. 11 refs.

  15. SPECT assay of radiolabeled monoclonal antibodies

    SciTech Connect

    Jaszczak, R.J.

    1992-02-01

    The accurate determination of the biodistribution of radiolabeled monoclonal antibodies (MoAbs) is important for calculation of dosimetry and evaluation of pharmacokinetic variables such as antibody dose and route of administration. The hypothesis of this application is that the biodistribution of radiolabeled monoclonal antibodies (MoAbs) can be quantitatively determined using single photon emission computed tomography (SPECT). The major thrusts during the third year include the continued development and evaluation of improved 3D SPECT acquisition and reconstruction approaches to improve quantitative imaging of radiolabeled monoclonal antibodies (MoAbs), and the implementation and evaluation of algorithms to register serial SPECT image data sets, or to register 3D SPECT images with 3D image data sets acquired from positron emission tomography (PEI) and magnetic resonance images (MRI). The research has involved the investigation of statistical models and iterative reconstruction algorithms that accurately account for the physical characteristics of the SPECT acquisition system. It is our belief that SPECT quantification can be improved by accurately modeling the physical processes such as attenuation, scatter, geometric collimator response, and other factors that affect the measured projection data.

  16. Small-animal SPECT and SPECT/CT: important tools for preclinical investigation.

    PubMed

    Franc, Benjamin L; Acton, Paul D; Mari, Carina; Hasegawa, Bruce H

    2008-10-01

    The need to study dynamic biologic processes in intact small-animal models of disease has stimulated the development of high-resolution nuclear imaging methods. These methods are capable of clarifying molecular interactions important in the onset and progression of disease, assessing the biologic relevance of drug candidates and potential imaging agents, and monitoring therapeutic effectiveness of pharmaceuticals serially within a single-model system. Single-photon-emitting radionuclides have many advantages in these applications, and SPECT can provide 3-dimensional spatial distributions of gamma- (and x-) ray-emitting radionuclide imaging agents or therapeutics. Furthermore, combining SPECT with CT in a SPECT/CT system can assist in defining the anatomic context of biochemical processes and improve the quantitative accuracy of the SPECT data. Over the past decade, dedicated small-animal SPECT and SPECT/CT systems have been developed in academia and industry. Although significant progress in this arena has been realized through system development and biologic application, further innovation continues to address challenges in camera sensitivity, spatial resolution, and image reconstruction and quantification. The innumerable applications of small-animal SPECT and SPECT/CT in drug development, cardiology, neurology, and oncology are stimulating further investment in education, research, and development of these dedicated small-animal imaging modalities. PMID:18794275

  17. Machine-learning model observer for detection and localization tasks in clinical SPECT-MPI

    NASA Astrophysics Data System (ADS)

    Parages, Felipe M.; O'Connor, J. Michael; Pretorius, P. Hendrik; Brankov, Jovan G.

    2016-03-01

    In this work we propose a machine-learning MO based on Naive-Bayes classification (NB-MO) for the diagnostic tasks of detection, localization and assessment of perfusion defects in clinical SPECT Myocardial Perfusion Imaging (MPI), with the goal of evaluating several image reconstruction methods used in clinical practice. NB-MO uses image features extracted from polar-maps in order to predict lesion detection, localization and severity scores given by human readers in a series of 3D SPECT-MPI. The population used to tune (i.e. train) the NB-MO consisted of simulated SPECT-MPI cases - divided into normals or with lesions in variable sizes and locations - reconstructed using filtered backprojection (FBP) method. An ensemble of five human specialists (physicians) read a subset of simulated reconstructed images, and assigned a perfusion score for each region of the left-ventricle (LV). Polar-maps generated from the simulated volumes along with their corresponding human scores were used to train five NB-MOs (one per human reader), which are subsequently applied (i.e. tested) on three sets of clinical SPECT-MPI polar maps, in order to predict human detection and localization scores. The clinical "testing" population comprises healthy individuals and patients suffering from coronary artery disease (CAD) in three possible regions, namely: LAD, LcX and RCA. Each clinical case was reconstructed using three reconstruction strategies, namely: FBP with no SC (i.e. scatter compensation), OSEM with Triple Energy Window (TEW) SC method, and OSEM with Effective Source Scatter Estimation (ESSE) SC. Alternative Free-Response (AFROC) analysis of perfusion scores shows that NB-MO predicts a higher human performance for scatter-compensated reconstructions, in agreement with what has been reported in published literature. These results suggest that NB-MO has good potential to generalize well to reconstruction methods not used during training, even for reasonably dissimilar datasets (i

  18. Respiratory Motion Detection and Correction in ECG-Gated SPECT: a New Approach

    PubMed Central

    Bitarafan, Ahmad; Rajabi, Hossein; Gruy, Bernhard; Rustgou, Feridoon; Sharafi, Ali Akbar; Firoozabady, Hasan; Yaghoobi, Nahid; Malek, Hadi; Pirich, Christian; Langesteger, Werner

    2008-01-01

    Objective Gated myocardial perfusion single-photon emission computed tomography (GSPECT) has been established as an accurate and reproducible diagnostic and prognostic technique for the assessment of myocardial perfusion and function. Respiratory motion is among the major factors that may affect the quality of myocardial perfusion imaging (MPI) and consequently the accuracy of the examination. In this study, we have proposed a new approach for the tracking of respiratory motion and the correction of unwanted respiratory motion by the use of respiratory-cardiac gated-SPECT (RC-GSPECT). In addition, we have evaluated the use of RC-GSPECT for quantitative and visual assessment of myocardial perfusion and function. Materials and Methods Twenty-six patients with known or suspected coronary artery disease (CAD)-underwent two-day stress and rest 99mTc-Tetrofosmin myocardial scintigraphy using both conventional GSPECT and RC-GSPECT methods. The respiratory signals were induced by use of a CT real-time position management (RPM) respiratory gating interface. A PIO-D144 card, which is transistor-transistor logic (TTL) compatible, was used as the input interface for simultaneous detection of both ECG and respiration signals. Results A total of 26 patients with known or suspected CAD were examined in this study. Stress and rest myocardial respiratory motion in the vertical direction was 8.8-16.6 mm (mean, 12.4 ± 2.9 mm) and 7.8-11.8 mm (mean, 9.5 ± 1.6 mm), respectively. The percentages of tracer intensity in the inferior, inferoseptal and septal walls as well as the inferior to lateral (I/L) uptake ratio was significantly higher with the use of RC-GSPECT as compared to the use of GSPECT (p < 0.01). In a left ventricular ejection fraction (LVEF) correlation analysis between the use of rest GSPECT and RC-GSPECT with echocardiography, better correlation was noted between RC-GSPECT and echocardiography as compared with the use of GSPECT (y = 0.9654x + 1.6514; r = 0.93, p < 0

  19. Pediatric solid tumors: Evaluation by gallium-67 SPECT studies

    SciTech Connect

    Rossleigh, M.A.; Murray, I.P.; Mackey, D.W.; Bargwanna, K.A.; Nayanar, V.V. )

    1990-02-01

    A retrospective review of 37 children with a variety of solid tumors who underwent 60 {sup 67}Ga single-photon emission computed tomographic (SPECT) studies was performed. These studies were correlated with clinical and radiological findings and, where possible, histopathologic confirmation. In all studies, SPECT gave better definition and better anatomic localization of disease sites than obtained with planar views. SPECT detected more lesions in the head and neck (planar 16, SPECT 19), chest (planar 39, SPECT 45), and abdomen (planar 22, SPECT 24). In six of 20 patients scanned following chemotherapy, SPECT was useful in demonstrating that tracer accumulation in a normally located and shaped thymus indicated uptake resulting from thymic regeneration rather than tumor recurrence. It is concluded that {sup 67}Ga SPECT studies are very useful in the pediatric population, where perhaps because of their small size, interpretation of standard planar views may be difficult.

  20. A guide to SPECT equipment for brain imaging

    SciTech Connect

    Hoffer, P.B.; Zubal, G.

    1991-12-31

    Single photon emission computed tomography (SPECT) was started by Kuhl and Edwards about 30 years ago. Their original instrument consisted of four focused Nal probes mounted on a moving gantry. During the 1980s, clinical SPECT imaging was most frequently performed using single-headed Anger-type cameras which were modified for rotational as well as static imaging. Such instruments are still available and may be useful in settings where there are few patients and SPECT is used only occasionally. More frequently, however, dedicated SPECT devices are purchased which optimize equipment potential while being user-friendly. Modern SPECT instrumentation incorporates improvements in the detector, computers, mathematical formulations, electronics and display systems. A comprehensive discussion of all aspects of SPECT is beyond the scope of this article. The authors, however, discuss general concepts of SPECT, the current state-of-the-art in clinical SPECT instrumentation, and areas of common misunderstanding. 9 refs.

  1. Differential impact of multi-focus fan beam collimation with L-mode and conventional systems on the accuracy of myocardial perfusion imaging: Quantitative evaluation using phantoms

    PubMed Central

    Onishi, Hideo; Matsutomo, Norikazu; Kangai, Yoshiharu; Saho, Tatsunori; Amijima, Hizuru

    2013-01-01

    Objective(s): A novel IQ-SPECT™ method has become widely used in clinical studies. The present study compares the quality of myocardial perfusion images (MPI) acquired using the IQ-SPECT™ (IQ-mode), conventional (180° apart: C-mode) and L-mode (90° apart: L-mode) systems. We assessed spatial resolution, image reproducibility and quantifiability using various physical phantoms. Methods: SPECT images were acquired using a dual-headed gamma camera with C-mode, L-mode, and IQ-mode acquisition systems from line source, pai and cardiac phantoms containing solutions of 99mTc. The line source phantom was placed in the center of the orbit and at ± 4.0, ± 8.0, ± 12.0, ± 16.0 and ± 20.0 cm off center. We examined quantifiability using the pai phantom comprising six chambers containing 0.0, 0.016, 0.03, 0.045, 0.062, and 0.074 MBq/mL of 99m-Tc and cross-calibrating the SPECT counts. Image resolution and reproducibility were quantified as myocardial wall thickness (MWT) and %uptake using polar maps. Results: The full width at half maximum (FWHM) of the IQ-mode in the center was increased by 11% as compared with C-mode, and FWHM in the periphery was increased 41% compared with FWHM at the center. Calibrated SPECT counts were essentially the same when quantified using IQ-and C-modes. IQ-SPECT images of MWT were significantly improved (P<0.001) over L-mode, and C-mode SPECT imaging with IQ-mode became increasingly inhomogeneous, both visually and quantitatively (C-mode vs. L-mode, ns; C-mode vs. IQ-mode, P<0.05). Conclusion: Myocardial perfusion images acquired by IQ-SPECT were comparable to those acquired by conventional and L-mode SPECT, but with significantly improved resolution and quality. Our results suggest that IQ-SPECT is the optimal technology for myocardial perfusion SPECT imaging. PMID:27408847

  2. SPECT imaging in a case of primary respiratory tract amyloidosis.

    PubMed

    Nishihara, M; Oda, J; Kamura, T; Kimura, M; Odano, I; Sakai, K

    1993-08-01

    SPECT findings in a very rare case of primary amyloidosis localized in the laryngotracheobronchial area are reported. SPECT using Tc-99m PYP revealed widespread uptake in the larynx and the entire tracheobronchial tree up to the subsegmental divisions; the areas corresponded to diffuse thickening and calcification of the walls on CT. SPECT using Ga-67 citrate also showed marked uptake in the same area, consistent with the findings shown by SPECT using Tc-99m PYP. PMID:8403700

  3. Transient myocardial ischaemia after acute myocardial infarction.

    PubMed Central

    Currie, P; Saltissi, S

    1990-01-01

    The prevalence and characteristics of transient myocardial ischaemia were studied in 203 patients with recent acute myocardial infarction by both early (6.4 days) and late (38 days) ambulatory monitoring of the ST segment. Transient ST segment depression was much commoner during late (32% patients) than early (14%) monitoring. Most transient ischaemia (greater than 85% episodes) was silent and 80% of patients had only silent episodes. During late monitoring painful ST depression was accompanied by greater ST depression and tended to occur at a higher heart rate. Late transient ischaemia showed a diurnal distribution, occurred at a higher initial heart rate, and was more often accompanied by a further increase in heart rate than early ischaemia. Thus in the first 2 months after myocardial infarction transient ischaemia became increasingly common and more closely associated with increased myocardial oxygen demand. Because transient ischaemic episodes during early and late ambulatory monitoring have dissimilar characteristics they may also have different pathophysiologies and prognostic implications. PMID:2245108

  4. Motion and deformation tracking for short-axis echo-planar myocardial perfusion imaging.

    PubMed

    Yang, G Z; Burger, P; Panting, J; Gatehouse, P D; Rueckert, D; Pennell, D J; Firmin, D N

    1998-09-01

    The assessment of regional myocardial perfusion during the first-pass of a contrast agent bolus requires tracking of the signal time course for each myocardial segment so that a detailed perfusion map can be derived. To obtain such a map in practice, however, is not trivial because deformation of the shape of the myocardium and respiratory-induced motion render a major difficulty in this process. This study describes an automated approach for motion and deformation tracking of functional myocardial perfusion images. The effectiveness of the described method has been evaluated using a numerical phantom and results are compared with those from existing techniques which use deformable models. Preliminary results from applying our approach to 20 patients are discussed and compared with those from SPECT studies. PMID:9873904

  5. Estimation of dynamic time activity curves from dynamic cardiac SPECT imaging

    NASA Astrophysics Data System (ADS)

    Hossain, J.; Du, Y.; Links, J.; Rahmim, A.; Karakatsanis, N.; Akhbardeh, A.; Lyons, J.; Frey, E. C.

    2015-04-01

    Whole-heart coronary flow reserve (CFR) may be useful as an early predictor of cardiovascular disease or heart failure. Here we propose a simple method to extract the time-activity curve, an essential component needed for estimating the CFR, for a small number of compartments in the body, such as normal myocardium, blood pool, and ischemic myocardial regions, from SPECT data acquired with conventional cameras using slow rotation. We evaluated the method using a realistic simulation of 99mTc-teboroxime imaging. Uptake of 99mTc-teboroxime based on data from the literature were modeled. Data were simulated using the anatomically-realistic 3D NCAT phantom and an analytic projection code that realistically models attenuation, scatter, and the collimator-detector response. The proposed method was then applied to estimate time activity curves (TACs) for a set of 3D volumes of interest (VOIs) directly from the projections. We evaluated the accuracy and precision of estimated TACs and studied the effects of the presence of perfusion defects that were and were not modeled in the estimation procedure. The method produced good estimates of the myocardial and blood-pool TACS organ VOIs, with average weighted absolute biases of less than 5% for the myocardium and 10% for the blood pool when the true organ boundaries were known and the activity distributions in the organs were uniform. In the presence of unknown perfusion defects, the myocardial TAC was still estimated well (average weighted absolute bias <10%) when the total reduction in myocardial uptake (product of defect extent and severity) was ≤5%. This indicates that the method was robust to modest model mismatch such as the presence of moderate perfusion defects and uptake nonuniformities. With larger defects where the defect VOI was included in the estimation procedure, the estimated normal myocardial and defect TACs were accurate (average weighted absolute bias ≈5% for a defect with 25% extent and 100% severity).

  6. Quantitative Signature of Coronary Steal in a Patient with Occluded Coronary Arteries Supported by Collateral Circulation Using Dynamic SPECT

    PubMed Central

    Shrestha, Uttam; Botvinick, Elias H.; Yeghiazarians, Yerem; Seo, Youngho; Gullberg, Grant T.

    2015-01-01

    Coronary steal (CS) is a physiological process that induces absolute decrease in blood flow in collateralized myocardium compared to resting flow during coronary vasodilation due to redistribution of blood away from collateral-dependent myocardium. Although, CS has been well known for decades, there are very few noninvasive perfusion studies in humans that quantitatively predict the existence of CS. In this study, we show that the quantitative measurement of absolute value of regional myocardial blood flow (MBF) and coronary flow reserve (CFR) using dynamic single photon emitted computed tomography (SPECT) can help estimate the presence of CS in myocardium with obstructed coronary artery and collateral circulation. PMID:27081301

  7. Clinical experience with technetium-99m teboroxime, a neutral, lipophilic myocardial perfusion imaging agent

    SciTech Connect

    Johnson, L.L.; Seldin, D.W. )

    1990-10-16

    Technetium-99m (Tc-99m) teboroxime is a new technetium-based myocardial perfusion imaging agent (investigational code = SQ30217 (Cardiotec, Squibb Diagnostics)). A member of a class of neutral, lipophilic, technetium-containing complexes known as boronic acid adducts of technetium dioxime (BATO) complexes, this agent is chemically very different from the cationic tracer thallium-201 (Tl-201) and from the cationic technetium complex Tc-99m sestamibi (Cardiolite, Du Pont Imaging Agents). Tc-99m teboroxime has high myocardial extraction, rapid blood clearance, little lung uptake and rapid myocardial washout. A biexponential pattern of myocardial washout is demonstrated in animals and in man. Effective half-lives of the 2 washout components in man are 5.2 minutes and 3.8 hours and represent approximately 66 and 33% of the myocardial activity, respectively. The first half-life for the myocardium is approximately 11 minutes. As the agent washes out of the heart, hepatic uptake occurs, peaking at about 5 minutes after injection. The liver is the major organ of excretion and receives, along with the large bowel, the largest radiation dose. Rapid imaging protocols using standard cameras have achieved good myocardial counts from 3 planar views acquired over a 4- to 5-minute period or for single photon emission computed tomography (SPECT) images acquired over a 10-minute period. An entire stress/rest procedure can be completed in 1 hour. Analysis of data from 155 patients from 4 centers using planar or SPECT imaging showed a sensitivity and specificity for blinded readings of 82 and 91%, respectively, when compared against overall clinical impression. 13 references.

  8. Myocardial infarction and marijuana.

    PubMed

    Charles, R; Holt, S; Kirkham, N

    1979-04-01

    Myocardial infarction in the virtual absence of risk factors occurred in a 25-year old man shortly after smoking a cigarette containing marijuana. Subsequent coronary arteriography was normal. PMID:466984

  9. Impact of hypertension on the accuracy of exercise stress myocardial perfusion imaging for the diagnosis of coronary artery disease

    PubMed Central

    Elhendy, A; van Domburg, R T; Sozzi, F; Poldermans, D; Bax, J; Roelandt, J

    2001-01-01

    AIM—To compare the accuracy of exercise stress myocardial perfusion single photon emission computed tomography (SPECT) imaging for the diagnosis of coronary artery disease in patients with and without hypertension.
METHODS—A symptom limited bicycle exercise stress test in conjunction with 99m technetium sestamibi or tetrofosmin SPECT imaging was performed in 332 patients (mean (SD) age, 57 (10) years; 257 men, 75 women) without previous myocardial infarction who underwent coronary angiography. Of these, 137 (41%) had hypertension. Rest SPECT images were acquired 24 hours after the stress test. An abnormal scan was defined as one with reversible or fixed perfusion defects.
RESULTS—In hypertensive patients, myocardial perfusion abnormalities were detected in 79 of 102 patients with significant coronary artery disease and in nine of 35 patients without. In normotensive patients, myocardial perfusion abnormalities were detected in 104 of 138 patients with significant coronary artery disease and in 16 of 57 patients without. There were no differences between normotensive and hypertensive patients in sensitivity (77% (95% confidence interval (CI) 69% to 86%) v 75% (95% CI 68% to 83%)), specificity (74% (95% CI 60% to 89%) v 72% (95% CI 60% to 84%)), and accuracy (77% (95% CI 70% to 84%) v 74% (95% CI 68% to 80%)) of exercise SPECT for diagnosing coronary artery disease. The accuracy of SPECT was greater than electrocardiography, both in hypertensive patients (p = 0.005) and in normotensive patients (p = 0.0001). For the detection of coronary artery disease in individual vessels, sensitivity was 58% (95% CI 51% to 65%) v 57% (95% CI 51% to 64%), specificity was 86% (95% CI 82% to 90%) v 85% (95% CI 81% to 89%), and accuracy was 74% (95% CI 70% to 78%) v 74% (95% CI 70% to 78%) in patients with and without hypertension (NS).
CONCLUSIONS—In the usual clinical setting, the value of exercise myocardial perfusion scintigraphy for diagnosing

  10. Automatic registration and alignment on a template of cardiac stress and rest reoriented SPECT images.

    PubMed

    Declerck, J; Feldmar, J; Goris, M L; Betting, F

    1997-12-01

    Single photon emission computed tomography (SPECT) imaging with 201Tl or 99mTc agent is used to assess the location or the extent of myocardial infarction or ischemia. A method is proposed to decrease the effect of operator variability in the visual or quantitative interpretation of scintigraphic myocardial perfusion studies. To effect this, the patient's myocardial images (target cases) are registered automatically over a template image, utilizing a nonrigid transformation. The intermediate steps are: 1) Extraction of feature points in both stress and rest three-dimensional (3-D) images. The images are resampled in a polar geometry to detect edge points, which in turn are filtered by the use of a priori constraints. The remaining feature points are assumed to be points on the edges of the left ventricular myocardium. 2) Registration of stress and rest images with a global affine transformation. The matching method is an adaptation of the iterative closest point algorithm. 3) Registration and morphological matching of both stress and rest images on a template using a nonrigid local spline transformation following a global affine transformation. 4) Resampling of both stress and rest images in the geometry of the template. Optimization of the method was performed on a database of 40 pairs of stress and rest images selected to obtain a wide variation of images and abnormalities. Further testing was performed on 250 cases selected from the same database on the basis of the availability of angiographic results and patient stratification. PMID:9533574

  11. Experimental myocardial infarction

    PubMed Central

    Kumar, Raj; Joison, Julio; Gilmour, David P.; Molokhia, Farouk A.; Pegg, C. A. S.; Hood, William B.

    1971-01-01

    The hemodynamic effects of tachycardia induced by atrial pacing were investigated in left ventricular failure of acute and healing experimental myocardial infarction in 20 intact, conscious dogs. Myocardial infarction was produced by gradual inflation of a balloon cuff device implanted around the left anterior descending coronary artery 10-15 days prior to the study. 1 hr after acute myocardial infarction, atrial pacing at a rate of 180 beats/min decreased left ventricular end-diastolic pressure from 19 to 8 mm Hg and left atrial pressure from 17 to 12 mm Hg, without change in cardiac output. In the healing phase of myocardial infarction 1 wk later, atrial pacing decreased left ventricular end-diastolic pressure from 17 to 9 mm Hg and increased the cardiac output by 37%. This was accompanied by evidence of peripheral vasodilation. In two dogs with healing anterior wall myocardial infarction, left ventricular failure was enhanced by partial occlusion of the circumflex coronary artery. Both the dogs developed pulmonary edema. Pacing improved left ventricular performance and relieved pulmonary edema in both animals. In six animals propranolol was given after acute infarction, and left ventricular function deteriorated further. However the pacing-induced augmentation of cardiac function was unaltered and, hence, is not mediated by sympathetics. The results show that the spontaneous heart rate in left ventricular failure of experimental canine myocardial infarction may be less than optimal and that maximal cardiac function may be achieved at higher heart rates. Images PMID:4395910

  12. Rodent brain imaging with SPECT/CT

    SciTech Connect

    Seo, Youngho; Gao, D.-W.; Hasegawa, Bruce H.; Dae, Michael W.; Franc, Benjamin L.

    2007-04-15

    We evaluated methods of imaging rat models of stroke in vivo using a single photon emission computed tomography (SPECT) system dedicated to small animal imaging (X-SPECT{sup TM}, Gamma Medica-Ideas, Northridge, CA). An animal model of ischemic stroke was developed for in vivo SPECT/CT imaging using the middle cerebral artery occlusion (MCAO) technique. The presence of cerebral ischemia was verified in ex vivo studies using triphenyltetrazolium chloride (TTC) staining. In vivo radionuclide imaging of cerebral blood flow was performed in rats following MCAO using dynamic planar imaging of {sup 99m}Tc-exametazime with parallel hole collimation. This was followed immediately by in vivo radionuclide imaging of cerebral blood flow with {sup 99m}Tc-exametazime in the same animals using 1-mm pinhole SPECT. Correlated computed tomography imaging was performed to localize radiopharmaceutical uptake. The animals were allowed to recover and ex vivo autoradiography was performed with separate administration of {sup 99m}Tc-exametazime. Time activity curve of {sup 99m}Tc-exametazime showed that the radiopharmaceutical uptake could be maintained for over 9 min. The activity would be expected to be relatively stable for a much longer period, although the data were only obtained for 9 min. TTC staining revealed sizable infarcts by visual observation of inexistence of TTC stain in infracted tissues of MCAO rat brains. In vivo SPECT imaging showed cerebral blood flow deficit in the MCAO model, and the in vivo imaging result was confirmed with ex vivo autoradiography. We have demonstrated a capability of imaging regions of cerebral blood flow deficit in MCAO rat brains in vivo using a pinhole SPECT dedicated to small animal imaging.

  13. Translation of Methodology Used In Human Myocardial Imaging to a Sheep Model of Acute Myocardial Infarction

    PubMed Central

    Bailey, Elizabeth A; Bailey, Dale L; Hunyor, Stephen; Ladd, Leigh; Bautovich, George J

    2013-01-01

    Introduction: Pre-clinical investigation of stem cells for repairing damaged myocardium predominantly uses rodents, however large animals have cardiac circulation closely resembling the human heart. The aim of this study was to evaluate whether SPECT/CT myocardial perfusion imaging (MPI) could be used for assessing sheep myocardium following an acute myocardial infarction (MI) and response to intervention. Methods: Eighteen sheep were enrolled in a pilot study to evaluate [99mTc]-sestamibi MPI at baseline, post-MI and after therapy. Modifications to the standard MPI protocols were developed. All data was reconstructed with OSEM using CT-derived attenuation and scatter correction. Standard analyses were performed and inter-observer agreement was measured using Kappa (κ). Power determined the sample sizes needed to show statistically significant changes due to intervention. Results: Ten sheep completed the full protocol. Data processed was performed with pre-existing hardware and software used in human MPI scanning. No improvement in perfusion was seen in the control group, however improvements of 15%-35% were seen after intra-myocardial stem cell administration. Inter-observer agreement was excellent (К=0.89). Using a target power of 0.9, 28 sheep were required to detect a 10-12% change in perfusion. Conclusion: This study demonstrates the suitability of large animal models for imaging with standard MPI protocols and its feasibility with a manageable number of animals. These protocols could be translated into humans to study the efficacy of stem cell therapy in heart regeneration and repair.

  14. Myocardial Noncompaction Presenting With Myocardial Bridge

    PubMed Central

    Shen, Yuechun; Li, Xinchun; Lu, Dongfeng; Xiao, Aiyi; Li, Jun

    2015-01-01

    Abstract Myocardial noncompaction, namly isolated noncompaction of the left ventricular myocardium (NVM), is a rare congenital disease. It can be either seen in the absence of other cardiac anomalies, or associated with other congenital cardiac defects, mostly stenotic lesions of the left ventricular outflow tract. A myocardial bridge (MB) is thought being associated with coronary heart disease, such as coronary spasm, arrhythmia, and so on. The significance of MB in association with other congenital cardiac conditions is unknown. We report a novel case who was presented NVM and MB. A 34-year-old man complained of chest prickling-like pain and dizzy for 1 year. His blood pressure was 110/70 mm Hg. Echocardiograph revealed increased trabeculations below the level of papillary muscle of left ventricle (LV); deep intertrabecular recesses in the endocardial wall of LV particularly in apex free wall; and LV ejection fraction of 57%. A coronary computerized tomography scan showed that part, 38.9 cm, of left descending artery tunnel was surrounding by cardiac muscles rather than resting on top of the myocardium. The therapeutics interventions included lifestyle cares, agents of anti-ischemia and improvement myocardial cell metabolism. The patient was followed up for 2.6 years, and his general condition was stable. This case indicates that NVM can be developed with MB, and the complete diagnosis of NVM and MB should be made by different image studies. PMID:26356695

  15. Design and evaluation of a mobile bedside PET/SPECT imaging system

    NASA Astrophysics Data System (ADS)

    Studenski, Matthew Thomas

    Patients confined to an intensive care unit, the emergency room, or a surgical suite are managed without nuclear medicine procedures such as positron emission tomography (PET) or single photon emission computed tomography (SPECT). These studies have diagnostic value which can greatly benefit the physician's treatment of the patient but require that the patient is moved to a scanner. This dissertation examines the feasibility of an economical PET/SPECT system that can be brought to the bedside of an immobile patient for imaging. We chose to focus on cardiac SPECT imaging including perfusion imaging using 99mTc tracers and viability imaging using 18F tracers first because of problems arising from positioning a detector beneath a patient's bed, a requirement for the opposed detector orientation in PET imaging. Second, SPECT imaging acquiring over the anterior 180 degrees of the patient results in reduced attenuation effects due to the heart's location in the anterior portion of the body. Four studies were done to assess the clinical feasibility of the mobile system; 1) the performance of the system was evaluated in SPECT mode at both 140 keV (99mTc tracers) and 511 keV (positron emitting tracers), 2) a dynamic cardiac phantom was used to develop and test image acquisition and processing methods for the system at both energies, 3) a high energy pinhole collimator was designed to reduce the effects of high energy photon penetration through the parallel hole collimator, and 4) we estimated the radiation dose to persons that would be in the vicinity of a patient to ensure that the effective dose is below the regulatory limit. With these studies, we show that the mobile system provides an economical means of bringing nuclear medicine to an immobile patient while staying below the regulatory dose limit to other persons. The system performed well at both 140 keV and 511 keV and provided viable images of a phantom myocardium at both energies. The system does not achieve the

  16. System calibration and image reconstruction for a new small-animal SPECT system

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Chun

    as the Gauss-Seidel (GS) iteration and the algebraic reconstruction technique (ART). These algorithms were compared in terms of their computational cost, data-agreement measures and subjective assessment of image quality. The spatial resolution of the imaging system was visualized through a miniature Derenzo hot-rod phantom. The smallest rods with 1-mm diameters and 3-mm center-to-center distance were clearly resolved. Mouse bone, kidney and cardiac images illustrated the ability of FastSPECT II to provide high-quality small-animal images. The dynamic-imaging capability was demonstrated via rat myocardial studies. FastSPECT II can be modified to achieve higher angular sampling and higher magnification. Fourier crosstalk analysis and synthetic phantom studies showed that higher angular sampling improved the spatial resolution and image quality along two transverse axes. Line-phantom and mouse-femur images demonstrated the sub-millimeter resolution of FastSPECT II in the high-magnification (18X) configuration.

  17. Performance evaluation of D-SPECT: a novel SPECT system for nuclear cardiology

    NASA Astrophysics Data System (ADS)

    Erlandsson, Kjell; Kacperski, Krzysztof; van Gramberg, Dean; Hutton, Brian F.

    2009-05-01

    D-SPECT (Spectrum Dynamics, Israel) is a novel SPECT system for cardiac perfusion studies. Based on CZT detectors, region-centric scanning, high-sensitivity collimators and resolution recovery, it offers potential advantages over conventional systems. A series of measurements were made on a β-version D-SPECT system in order to evaluate its performance in terms of energy resolution, scatter fraction, sensitivity, count rate capability and resolution. Corresponding measurements were also done on a conventional SPECT system (CS) for comparison. The energy resolution of the D-SPECT system at 140 keV was 5.5% (CS: 9.25%), the scatter fraction 30% (CS: 34%), the planar sensitivity 398 s-1 MBq-1 per head (99mTc, 10 cm) (CS: 72 s-1 MBq-1), and the tomographic sensitivity in the heart region was in the range 647-1107 s-1 MBq-1 (CS: 141 s-1 MBq-1). The count rate increased linearly with increasing activity up to 1.44 M s-1. The intrinsic resolution was equal to the pixel size, 2.46 mm (CS: 3.8 mm). The average reconstructed resolution using the standard clinical filter was 12.5 mm (CS: 13.7 mm). The D-SPECT has superior sensitivity to that of a conventional system with similar spatial resolution. It also has excellent energy resolution and count rate characteristics, which should prove useful in dynamic and dual radionuclide studies.

  18. Patient position alters attenuation effects in multipinhole cardiac SPECT

    SciTech Connect

    Timmins, Rachel; Ruddy, Terrence D.; Wells, R. Glenn

    2015-03-15

    Purpose: Dedicated cardiac cameras offer improved sensitivity over conventional SPECT cameras. Sensitivity gains are obtained by large numbers of detectors and novel collimator arrangements such as an array of multiple pinholes that focus on the heart. Pinholes lead to variable amounts of attenuation as a source is moved within the camera field of view. This study evaluated the effects of this variable attenuation on myocardial SPECT images. Methods: Computer simulations were performed for a set of nine point sources distributed in the left ventricular wall (LV). Sources were placed at the location of the heart in both an anthropomorphic and a water-cylinder computer phantom. Sources were translated in x, y, and z by up to 5 cm from the center. Projections were simulated with and without attenuation and the changes in attenuation were compared. A LV with an inferior wall defect was also simulated in both phantoms over the same range of positions. Real camera data were acquired on a Discovery NM530c camera (GE Healthcare, Haifa, Israel) for five min in list-mode using an anthropomorphic phantom (DataSpectrum, Durham, NC) with 100 MBq of Tc-99m in the LV. Images were taken over the same range of positions as the simulations and were compared based on the summed perfusion score (SPS), defect width, and apparent defect uptake for each position. Results: Point sources in the water phantom showed absolute changes in attenuation of ≤8% over the range of positions and relative changes of ≤5% compared to the apex. In the anthropomorphic computer simulations, absolute change increased to 20%. The changes in relative attenuation caused a change in SPS of <1.5 for the water phantom but up to 4.2 in the anthropomorphic phantom. Changes were larger for axial than for transverse translations. These results were supported by SPS changes of up to six seen in the physical anthropomorphic phantom for axial translations. Defect width was also seen to significantly increase. The

  19. Freehand SPECT in low uptake situations

    NASA Astrophysics Data System (ADS)

    Lasser, Tobias; Ziegler, Sibylle I.; Navab, Nassir

    2011-03-01

    3D functional imaging in the operating room can be extremely useful for some procedures like SLN mapping or SLN biopsies. Freehand SPECT is an example of such an imaging modality, combining manually scanned, hand-held 1D gamma detectors with spatial positioning systems in order to reconstruct localized 3D SPECT images, for example in the breast or neck region. Standard series expansion methods are applied together with custom physical models of the acquisition process and custom filtering procedures to perform 3D tomographic reconstruction from sparse, limited-angle and irregularly sampled data. A Freehand SPECT system can easily be assembled on a mobile cart suitable for use in the operating room. This work addresses in particular the problem of objects with low uptake (like sentinel lymph nodes), where reconstruction tends to be difficult due to low signal to noise ratio. In a neck-like phantom study, we show that four simulated nodes of 250 microliter volume with 0.06% respectively 0.03% uptake of a virtual 70MBq injection of Tc99m (the typical activity for SLN procedures at our hospital) in a background of water can be reconstructed successfully using careful filtering procedures in the reconstruction pipeline. Ten independent Freehand SPECT scans of the phantom were performed by several different operators, with an average scan duration of 5.1 minutes. The resulting reconstructions show an average spatial accuracy within voxel dimensions (2.5mm) compared to CT and exhibit correct relative quantification.

  20. Body Deformation Correction for SPECT Imaging

    PubMed Central

    Gu, Songxiang; McNamara, Joseph E.; Mitra, Joyeeta; Gifford, Howard C.; Johnson, Karen; Gennert, Michael A.; King, Michael A.

    2010-01-01

    Patient motion degrades the quality of SPECT studies. Body bend and twist are types of patient deformation, which may occur during SPECT imaging, and which has been generally ignored in SPECT motion correction strategies. To correct for these types of motion, we propose a deformation model and its inclusion within an iterative reconstruction algorithm. Two experiments were conducted to investigate the applicability of our model. In the first experiment, the return of the postmotion-compensation locations of markers on the body-surface of a volunteer to approximate their original coordinates is used to examine our method of estimating the parameters of our model and the parameters’ use in undoing deformation. The second experiment employed simulated projections of the MCAT phantom formed using an analytical projector which includes attenuation and distance-dependent resolution to investigate applications of our model in reconstruction. We demonstrate in the simulation studies that twist and bend can significantly degrade SPECT image quality visually. Our correction strategy is shown to be able to greatly diminish the degradation seen in the slices, provided the parameters are estimated accurately. We view this work as a first step towards being able to estimate and correct patient deformation based on information obtained from marker tracking data. PMID:20336188

  1. Beam hardening artifact reduction using dual energy computed tomography: implications for myocardial perfusion studies

    PubMed Central

    Carrascosa, Patricia; Cipriano, Silvina; De Zan, Macarena; Deviggiano, Alejandro; Capunay, Carlos; Cury, Ricardo C.

    2015-01-01

    Background Myocardial computed tomography perfusion (CTP) using conventional single energy (SE) imaging is influenced by the presence of beam hardening artifacts (BHA), occasionally resembling perfusion defects and commonly observed at the left ventricular posterobasal wall (PB). We therefore sought to explore the ability of dual energy (DE) CTP to attenuate the presence of BHA. Methods Consecutive patients without history of coronary artery disease who were referred for computed tomography coronary angiography (CTCA) due to atypical chest pain and a normal stress-rest SPECT and had absence or mild coronary atherosclerosis constituted the study population. The study group was acquired using DE and the control group using SE imaging. Results Demographical characteristics were similar between groups, as well as the heart rate and the effective radiation dose. Myocardial signal density (SD) levels were evaluated in 280 basal segments among the DE group (140 PB segments for each energy level from 40 to 100 keV; and 140 reference segments), and in 40 basal segments (at the same locations) among the SE group. Among the DE group, myocardial SD levels and myocardial SD ratio evaluated at the reference segment were higher at low energy levels, with significantly lower SD levels at increasing energy levels. Myocardial signal-to-noise ratio was not significantly influenced by the energy level applied, although 70 keV was identified as the energy level with the best overall signal-to-noise ratio. Significant differences were identified between the PB segment and the reference segment among the lower energy levels, whereas at ≥70 keV myocardial SD levels were similar. Compared to DE reconstructions at the best energy level (70 keV), SE acquisitions showed no significant differences overall regarding myocardial SD levels among the reference segments. Conclusions BHA that influence the assessment of myocardial perfusion can be attenuated using DE at 70 keV or higher. PMID

  2. Monte Carlo scatter correction for SPECT

    NASA Astrophysics Data System (ADS)

    Liu, Zemei

    The goal of this dissertation is to present a quantitatively accurate and computationally fast scatter correction method that is robust and easily accessible for routine applications in SPECT imaging. A Monte Carlo based scatter estimation method is investigated and developed further. The Monte Carlo simulation program SIMIND (Simulating Medical Imaging Nuclear Detectors), was specifically developed to simulate clinical SPECT systems. The SIMIND scatter estimation (SSE) method was developed further using a multithreading technique to distribute the scatter estimation task across multiple threads running concurrently on multi-core CPU's to accelerate the scatter estimation process. An analytical collimator that ensures less noise was used during SSE. The research includes the addition to SIMIND of charge transport modeling in cadmium zinc telluride (CZT) detectors. Phenomena associated with radiation-induced charge transport including charge trapping, charge diffusion, charge sharing between neighboring detector pixels, as well as uncertainties in the detection process are addressed. Experimental measurements and simulation studies were designed for scintillation crystal based SPECT and CZT based SPECT systems to verify and evaluate the expanded SSE method. Jaszczak Deluxe and Anthropomorphic Torso Phantoms (Data Spectrum Corporation, Hillsborough, NC, USA) were used for experimental measurements and digital versions of the same phantoms employed during simulations to mimic experimental acquisitions. This study design enabled easy comparison of experimental and simulated data. The results have consistently shown that the SSE method performed similarly or better than the triple energy window (TEW) and effective scatter source estimation (ESSE) methods for experiments on all the clinical SPECT systems. The SSE method is proven to be a viable method for scatter estimation for routine clinical use.

  3. Pitfalls and artifacts using the D-SPECT dedicated cardiac camera.

    PubMed

    Allie, Rayjanah; Hutton, Brian F; Prvulovich, Elizabeth; Bomanji, Jamshed; Michopoulou, Sofia; Ben-Haim, Simona

    2016-04-01

    Myocardial perfusion imaging is a well-established and widely used imaging technique for the assessment of patients with known or suspected coronary artery disease. Pitfalls and artifacts associated with conventional gamma cameras are well known, and the ways to avoid and correct them have been described. In recent years solid-state detector dedicated cardiac cameras were introduced and have been shown to offer improved accuracy in addition to new imaging protocols and novel applications. The purpose of this manuscript is to familiarize the readers with the causes and effects of technical, patient-related, and operator-related pitfalls and artifacts associated with the D-SPECT dedicated cardiac camera with solid-state detectors. The manuscript offers guidance on how to avoid these factors, how to detect them, and how to correct better for them, providing high-quality diagnostic images. PMID:26403143

  4. Computational tools and methods for objective assessment of image quality in x-ray CT and SPECT

    NASA Astrophysics Data System (ADS)

    Palit, Robin

    Computational tools of use in the objective assessment of image quality for tomography systems were developed for computer processing units (CPU) and graphics processing units (GPU) in the image quality lab at the University of Arizona. Fast analytic x-ray projection code called IQCT was created to compute the mean projection image for cone beam multi-slice helical computed tomography (CT) scanners. IQCT was optimized to take advantage of the massively parallel architecture of GPUs. CPU code for computing single photon emission computed tomography (SPECT) projection images was written calling upon previous research in the image quality lab. IQCT and the SPECT modeling code were used to simulate data for multi-modality SPECT/CT observer studies. The purpose of these observer studies was to assess the benefit in image quality of using attenuation information from a CT measurement in myocardial SPECT imaging. The observer chosen for these studies was the scanning linear observer. The tasks for the observer were localization of a signal and estimation of the signal radius. For the localization study, area under the localization receiver operating characteristic curve (A LROC) was computed as AMeasLROC = 0.89332 ± 0.00474 and ANoLROC = 0.89408 ± 0.00475, where "Meas" implies the use of attenuation information from the CT measurement, and "No" indicates the absence of attenuation information. For the estimation study, area under the estimation receiver operating characteristic curve (AEROC) was quantified as AMeasEROC = 0.55926 ± 0.00731 and ANoEROC = 0.56167 ± 0.00731. Based on these results, it was concluded that the use of CT information did not improve the scanning linear observer's ability to perform the stated myocardial SPECT tasks. The risk to the patient of the CT measurement was quantified in terms of excess effective dose as 2.37 mSv for males and 3.38 mSv for females. Another image quality tool generated within this body of work was a singular value

  5. Respiratory motion correction in gated cardiac SPECT using quaternion-based, rigid-body registration.

    PubMed

    Parker, Jason G; Mair, Bernard A; Gilland, David R

    2009-10-01

    In this article, a new method is introduced for estimating the motion of the heart due to respiration in gated cardiac SPECT using a rigid-body model with rotation parametrized by a unit quaternion. The method is based on minimizing the sum of squared errors between the reference and the deformed frames resulting from the usual optical flow constraint by using an optimized conjugate gradient routine. This method does not require any user-defined parameters or penalty terms, which simplifies its use in a clinical setting. Using a mathematical phantom, the method was quantitatively compared to the principal axis method, as well as an iterative method in which the rotation matrix was represented by Euler angles. The quaternion-based method was shown to be substantially more accurate and robust across a wide range of extramyocardial activity levels than the principal axis method. Compared with the Euler angle representation, the quaternion-based method resulted in similar accuracy but a significant reduction in computation times. Finally, the quaternion-based method was investigated using a respiratory-gated cardiac SPECT acquisition of a human subject. The motion-corrected image has increased sharpness and myocardial uniformity compared to the uncorrected image. PMID:19928105

  6. Story of Rubidium-82 and Advantages for Myocardial Perfusion PET Imaging.

    PubMed

    Chatal, Jean-François; Rouzet, François; Haddad, Ferid; Bourdeau, Cécile; Mathieu, Cédric; Le Guludec, Dominique

    2015-01-01

    Rubidium-82 has a long story, starting in 1954. After preclinical studies in dogs showing that myocardial uptake of this radionuclide was directly proportional to myocardial blood flow (MBF), clinical studies were performed in the 80s leading to an approval in the USA in 1989. From that time, thousands of patients have been tested and their results have been reported in three meta-analyses. Pooled patient-based sensitivity and specificity were, respectively, 0.91 and 0.90. By comparison with (99m)Tc-SPECT, (82)Rb PET had a much better diagnostic accuracy, especially in obese patients with body mass index ≥30 kg/m(2) (85 versus 67% with SPECT) and in women with large breasts. A great advantage of (82)Rb PET is its capacity to accurately quantify MBF. Quite importantly, it has been recently shown that coronary flow reserve is associated with adverse cardiovascular events independently of luminal angiographic severity. Moreover, coronary flow reserve is a functional parameter particularly useful in the estimate of microvascular dysfunction, such as in diabetes mellitus. Due to the very short half-life of rubidium-82, the effective dose calculated for a rest/stress test is roughly equivalent to the annual natural exposure and even less when stress-only is performed with a low activity compatible with a good image quality with the last generation 3D PET scanners. There is still some debate on the relative advantages of (82)Rb PET with regard to (99m)Tc-SPECT. For the last 10 years, great technological advances substantially improved performances of SPECT with its accuracy getting closer to this of (82)Rb/PET. Currently, the main advantages of PET are its capacity to accurately quantify MBF and to deliver a low radiation exposure. PMID:26442267

  7. Story of Rubidium-82 and Advantages for Myocardial Perfusion PET Imaging

    PubMed Central

    Chatal, Jean-François; Rouzet, François; Haddad, Ferid; Bourdeau, Cécile; Mathieu, Cédric; Le Guludec, Dominique

    2015-01-01

    Rubidium-82 has a long story, starting in 1954. After preclinical studies in dogs showing that myocardial uptake of this radionuclide was directly proportional to myocardial blood flow (MBF), clinical studies were performed in the 80s leading to an approval in the USA in 1989. From that time, thousands of patients have been tested and their results have been reported in three meta-analyses. Pooled patient-based sensitivity and specificity were, respectively, 0.91 and 0.90. By comparison with 99mTc-SPECT, 82Rb PET had a much better diagnostic accuracy, especially in obese patients with body mass index ≥30 kg/m2 (85 versus 67% with SPECT) and in women with large breasts. A great advantage of 82Rb PET is its capacity to accurately quantify MBF. Quite importantly, it has been recently shown that coronary flow reserve is associated with adverse cardiovascular events independently of luminal angiographic severity. Moreover, coronary flow reserve is a functional parameter particularly useful in the estimate of microvascular dysfunction, such as in diabetes mellitus. Due to the very short half-life of rubidium-82, the effective dose calculated for a rest/stress test is roughly equivalent to the annual natural exposure and even less when stress-only is performed with a low activity compatible with a good image quality with the last generation 3D PET scanners. There is still some debate on the relative advantages of 82Rb PET with regard to 99mTc-SPECT. For the last 10 years, great technological advances substantially improved performances of SPECT with its accuracy getting closer to this of 82Rb/PET. Currently, the main advantages of PET are its capacity to accurately quantify MBF and to deliver a low radiation exposure. PMID:26442267

  8. [Noninvasive diagnosis of cardiac involvement by technetium-99m-pyrophosphate (Tc-99m PYP) myocardial scintigraphy in 2 cases of familial amyloid polyneuropathy and 1 case of secondary amyloidosis].

    PubMed

    Takezaki, M; Ishida, Y; Morozumi, T; Tani, A; Sato, H; Hori, M; Kitabatake, A; Kamada, T; Kimura, K; Kozuka, T

    1989-12-01

    To validate the significance of technetium-99m-pyrophosphate (Tc-99m PYP) myocardial scintigraphy in diagnosing cardiac amyloidosis, 2 patients with familial amyloid polyneuropathy (FAP) and 1 patient with amyloidosis secondary to chronic rheumatic arthritis were studied. All three patients had echocardiographic abnormalities, which were increased wall thickness of the interventricular septum and the left ventricular posterior wall, and granular sparkling appearance in the septum. In 2 patients with FAP, abnormal myocardial uptake of Tc-99m PYP was diffusely detected in Tc-99m PYP SPECT. In the remaining 1 patient with secondary amyloidosis, however, Tc-99m PYP SPECT showed no abnormality, although we had confirmed the presence of myocardial amyloid deposits (type AA amyloid protein) with high amount in the histological examination. Thus, these results indicate that Tc-99m PYP scintigraphy may have a limitation in detecting cardiac involvement in secondary amyloidosis although it is useful in FAP. PMID:2560088

  9. Myocardial diseases of animals.

    PubMed Central

    Van Vleet, J. F.; Ferrans, V. J.

    1986-01-01

    In this review we have attempted a comprehensive compilation of the cardiac morphologic changes that occur in spontaneous and experimental myocardial diseases of animals. Our coverage addresses diseases of mammals and birds and includes these diseases found in both domesticated and wild animals. A similar review of the myocardial diseases in this broad range of animal species has not been attempted previously. We have summarized and illustrated the gross, microscopic, and ultrastructural alterations for these myocardial diseases; and, whenever possible, we have reviewed their biochemical pathogenesis. We have arranged the myocardial diseases for presentation and discussion according to an etiologic classification with seven categories. These include a group of idiopathic or primary cardiomyopathies recognized in man (hypertrophic, dilated, and restrictive types) and a large group of secondary cardiomyopathies with known causes, such as inherited tendency; nutritional deficiency; toxicity; physical injury and shock; endocrine disorders, and myocarditides of viral, bacterial, and protozoal causation. Considerable overlap exists between each of the etiologic groups in the spectrum of pathologic alterations seen in the myocardium. These include various degenerative changes, myocyte necrosis, and inflammatory lesions. However, some diseases show rather characteristic myocardial alterations such as vacuolar degeneration in anthracycline cardiotoxicity, myofibrillar lysis in furazolidone cardiotoxicity, calcification in calcinosis of mice, glycogen accumulation in the glycogenoses, lipofuscinosis in cattle, fatty degeneration in erucic acid cardiotoxicity, myofiber disarray in hypertrophic cardiomyopathy, and lymphocytic inflammation with inclusion bodies in canine parvoviral myocarditis. The myocardial diseases represent the largest group in the spectrum of spontaneous cardiac diseases of animals. Pericardial and endocardial diseases and congential cardiac diseases are

  10. Assessing Cardiac Injury in Mice With Dual Energy-MicroCT, 4D-MicroCT, and MicroSPECT Imaging After Partial Heart Irradiation

    SciTech Connect

    Lee, Chang-Lung; Min, Hooney; Befera, Nicholas; Clark, Darin; Qi, Yi; Das, Shiva; Johnson, G. Allan; Badea, Cristian T.; Kirsch, David G.

    2014-03-01

    Purpose: To develop a mouse model of cardiac injury after partial heart irradiation (PHI) and to test whether dual energy (DE)-microCT and 4-dimensional (4D)-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging using micro-single photon emission computed tomography (SPECT). Methods and Materials: To study cardiac injury from tangent field irradiation in mice, we used a small-field biological irradiator to deliver a single dose of 12 Gy x-rays to approximately one-third of the left ventricle (LV) of Tie2Cre; p53{sup FL/+} and Tie2Cre; p53{sup FL/−} mice, where 1 or both alleles of p53 are deleted in endothelial cells. Four and 8 weeks after irradiation, mice were injected with gold and iodinated nanoparticle-based contrast agents, and imaged with DE-microCT and 4D-microCT to evaluate myocardial vascular permeability and cardiac function, respectively. Additionally, the same mice were imaged with microSPECT to assess myocardial perfusion. Results: After PHI with tangent fields, DE-microCT scans showed a time-dependent increase in accumulation of gold nanoparticles (AuNp) in the myocardium of Tie2Cre; p53{sup FL/−} mice. In Tie2Cre; p53{sup FL/−} mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53{sup FL/+} mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R{sup 2} = 0.97) between the fraction of the LV that accumulated AuNp and the fraction of LV with a perfusion defect. Furthermore, 4D-microCT scans demonstrated that PHI caused a markedly decreased ejection fraction, and higher end-diastolic and end-systolic volumes, to develop in Tie2Cre; p53{sup FL/−} mice, which were associated with compensatory cardiac hypertrophy of the heart that was not irradiated. Conclusions: Our results show that DE-microCT and 4D-microCT with nanoparticle-based contrast agents are novel imaging approaches

  11. Acute insulin resistance in ST-segment elevation myocardial infarction in non-diabetic patients is associated with incomplete myocardial reperfusion and impaired coronary microcirculatory function

    PubMed Central

    2014-01-01

    Background Insulin resistance (IR) assessed by the Homeostatic Model Assessment (HOMA) index in the acute phase of myocardial infarction in non-diabetic patients was recently established as an independent predictor of intrahospital mortality. In this study we postulated that acute IR is a dynamic phenomenon associated with the development of myocardial and microvascular injury and larger final infarct size in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (pPCI). Methods In 104 consecutive patients with the first anterior STEMI without diabetes, the HOMA index was determined on the 2nd and 7th day after pPCI. Worst-lead residual ST-segment elevation (ST-E) on postprocedural ECG, coronary flow reserve (CFR) determined by transthoracic Doppler echocardiography on the 2nd day after pPCI and fixed perfusion defect on single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) determined six weeks after pPCI were analyzed according to HOMA indices. Results IR was present in 55 % and 58 % of patients on day 2 and day 7, respectively. Incomplete post-procedural ST-E resolution was more frequent in patients with IR compared to patients without IR, both on day 2 (p = 0.001) and day 7 (p < 0.001). The HOMA index on day 7 correlated with SPECT-MPI perfusion defect (r = 0.331), whereas both HOMA indices correlated well with CFR (r = -0.331 to -0.386) (p < 0.01 for all). In multivariable backward logistic regression analysis adjusted for significant univariate predictors and potential confounding variables, IR on day 2 was an independent predictor of residual ST-E ≥ 2 mm (OR 11.70, 95% CI 2.46-55.51, p = 0.002) and CFR < 2 (OR = 5.98, 95% CI 1.88-19.03, p = 0.002), whereas IR on day 7 was an independent predictor of SPECT-MPI perfusion defect > 20% (OR 11.37, 95% CI 1.34-96.21, p = 0.026). Conclusion IR assessed by the HOMA index during the

  12. Plasmid-mediated VEGF gene transfer induces cardiomyogenesis and reduces myocardial infarct size in sheep.

    PubMed

    Vera Janavel, G; Crottogini, A; Cabeza Meckert, P; Cuniberti, L; Mele, A; Papouchado, M; Fernández, N; Bercovich, A; Criscuolo, M; Melo, C; Laguens, R

    2006-08-01

    We have recently reported that in pigs with chronic myocardial ischemia heart transfection with a plasmid encoding the 165 isoform of human vascular endothelial growth factor (pVEGF165) induces an increase in the mitotic index of adult cardiomyocytes and cardiomyocyte hyperplasia. On these bases we hypothesized that VEGF gene transfer could also modify the evolution of experimental myocardial infarct. In adult sheep pVEGF165 (3.8 mg, n=7) or empty plasmid (n=7) was injected intramyocardially 1 h after coronary artery ligation. After 15 days infarct area was 11.3+/-1.3% of the left ventricle in the VEGF group and 18.2+/-2.1% in the empty plasmid group (P<0.02). The mechanisms involved in infarct size reduction (assessed in additional sheep at 7 and 10 days after infarction) included an increase in early angiogenesis and arteriogenesis, a decrease in peri-infarct fibrosis, a decrease in myofibroblast proliferation, enhanced cardiomyoblast proliferation and mitosis of adult cardiomyocytes with occasional cytokinesis. Resting myocardial perfusion (99mTc-sestamibi SPECT) was higher in VEGF-treated group than in empty plasmid group 15 days after myocardial infarction. We conclude that plasmid-mediated VEGF gene transfer reduces myocardial infarct size by a combination of effects including neovascular proliferation, modification of fibrosis and cardiomyocyte regeneration. PMID:16572192

  13. Angina and Mental Stress-Induced Myocardial Ischemia

    PubMed Central

    Pimple, Pratik; Shah, Amit J.; Rooks, Cherie; Bremner, J. Douglas; Nye, Jonathon; Ibeanu, Ijeoma; Raggi, Paolo; Vaccarino, Viola

    2015-01-01

    Objective Mental stress-induced myocardial ischemia is a common phenomenon in patients with coronary artery disease (CAD) and an emerging prognostic factor. Mental stress ischemia is correlated with ambulatory ischemia. However, whether it is related to angina symptoms during daily life has not been examined. Methods We assessed angina-frequency (past month) in 98 post-myocardial infarction (MI) subjects (age 18-60 years) using the Seattle Angina Questionnaire. Patients underwent [99mTc]sestamibi SPECT perfusion imaging at rest, after mental stress, and after exercise/pharmacological stress. Summed scores of perfusion abnormalities were obtained by observer-independent software. A summed-difference score (SDS), the difference between stress and rest scores, was used to quantify myocardial ischemia under both stress conditions. Results The mean age was 50 years, 50% were female and 60% were non-white. After adjustment for age, sex, smoking, CAD-severity, depressive, anger and anxiety symptoms, each 1-point increase in mental-stress SDS was associated with 1.73-unit increase in the angina-frequency score (95% CI: 0.09-3.37) and 17% higher odds of being in a higher angina-frequency category (OR: 1.17, 95% CI: 1.00-1.38). Depressive symptoms were associated with 12% higher odds of being in a higher angina-frequency category (OR: 1.12, 95% CI: 1.03-1.21). In contrast, exercise/pharmacological stress-induced SDS was not associated with angina-frequency. Conclusion Among young and middle-aged post-MI patients, myocardial ischemia induced by mental stress in the lab, but not by exercise/pharmacological stress, is associated with higher frequency of retrospectively reported angina during the day. Psychosocial stressors related to mental stress ischemia may be important contributory factor to daily angina. PMID:25727240

  14. The role of SPECT/CT in skeletal malignancies.

    PubMed

    Ghosh, Partha

    2014-04-01

    Bone scintigraphy is widely used for the detection of skeletal metastases, particularly in prostate and breast cancer. Although planar imaging is widely used, single-photon emission computed tomography (SPECT) imaging has demonstrated higher sensitivity. SPECT/CT imaging with the integration of CT and SPECT gantries has enhanced bone scintigraphy by providing accurate lesion localization and characterization of equivocal and solitary bone lesions. The key impact has been enhanced diagnostic confidence in the differentiation of benign from malignant skeletal lesions made possible by accurate localization of lesions to facet joints, vertebral bodies, or pedicles due to the exact coregistration of CT and SPECT as well as consideration of sclerosis or lysis within the lesion seen on CT. Several studies comparing planar, SPECT, and SPECT/CT in equivocal lesions have demonstrated a substantial improvement in specificity with SPECT/CT. This review highlights the key studies demonstrating the value of SPECT/CT in the evaluation of skeletal malignancies and shows clinical examples illustrating the impact of SPECT/CT in improved localization and characterization of skeletal lesions. PMID:24715449

  15. I-123 Iofetamine SPECT scan in children with neurological disorders

    SciTech Connect

    Flamini, J.R.; Konkol, R.J.; Wells, R.G.; Sty, J.R. )

    1990-10-01

    I-123 Iofetamine (IMP) single photon emission computed tomography (SPECT) imaging of the brain in 42 patients (ages 14 days to 23 years) was compared with other localizing studies in children with neurological diseases. All had an EEG and at least one imaging study of the brain (computed tomography (CT) or magnetic resonance imaging (MRI), or both). Seventy-eight percent of the patients had an EEG within 24-72 hours of the IMP-SPECT scan. Thirty-five (83%) had a history of seizures, and the remainder had other neurological conditions without a history of seizures. In most cases, a normal EEG reading with normal CT or MRI result predicted a normal SPECT study. When the EEG was abnormal the majority of the IMP-SPECT scans were abnormal and localized the abnormality to the same region. A comparison with CT and MRI showed that structural abnormalities involving the cortex were usually well demonstrated with IMP-SPECT imaging. Structural lesions confined to the white matter were generally not detectable with IMP-SPECT. In a few cases, SPECT scans revealed abnormalities in deep brain areas not identified by EEG. IMP-SPECT imaging is a valuable technique for the detection and localization of abnormal cerebral metabolic activity in children with seizure disorders. A correlation with CT or MRI is essential for proper interpretation of abnormalities detected with IMP SPECT imaging.

  16. Bovine myocardial epithelial inclusions.

    PubMed

    Baker, D C; Schmidt, S P; Langheinrich, K A; Cannon, L; Smart, R A

    1993-01-01

    Light microscopic, histochemical, immunohistochemical, and ultrastructural methods were used to examine myocardial epithelial masses in the hearts of ten cattle. The tissues consisted of paraffin-embedded or formalin-fixed samples from eight hearts that were being inspected in slaughter houses and from two hearts from calves that died of septicemia. The ages of the cattle ranged from 4 days to 12 years; the breeds were unspecified for all but one Hereford female and the two Holstein calves; and there were three males, four females, and three steers. The masses in these cases were compared with similar appearing lesions found in other animal species. The lesions in the bovine hearts were single to multiple, well circumscribed, found in the left ventricle wall, and composed of squamous to cuboidal epithelial cells that formed tubular, ductular, and acinar structures with lumens that were void or filled with amorphous protein globules. Electron microscopic examination revealed epithelial cells that had sparse apical microvilli, tight apical intercellular junctions, perinuclear bundles of filaments, and rare cilia. Almost half of the bovine epithelial masses (4/9) had occasional diastase-resistant periodic acid-Schiff-positive granules in their cytoplasm, and few had hyaluronidase-resistant alcian blue-positive granules (2/9) or colloidal iron-positive granules (1/9). All myocardial masses had abundant collagen surrounding the tubular and acinar structures, and 2/9 had elastin fibers as well. None of the myocardial masses had Churukian-Schenk or Fontana Masson's silver staining granules in epithelial cells. Immunohistochemically, all bovine myocardial tumors stained positively for cytokeratin (8/8), and occasional masses stained positively for vimentin (3/8) or carcinoembryonic antigen (3/8). None of the masses stained positively for desmin. The myocardial epithelial tumors most likely represent endodermal rests of tissue misplaced during organogenesis. PMID:7680178

  17. SPECT/CT Imaging of High-Risk Atherosclerotic Plaques using Integrin-Binding RGD Dimer Peptides

    PubMed Central

    Sun Yoo, Jung; Lee, Jonghwan; Ho Jung, Jae; Seok Moon, Byung; Kim, Soonhag; Chul Lee, Byung; Eun Kim, Sang

    2015-01-01

    Vulnerable atherosclerotic plaques with unique biological signatures are responsible for most major cardiovascular events including acute myocardial infarction and stroke. However, current clinical diagnostic approaches for atherosclerosis focus on anatomical measurements such as the degree of luminal stenosis and wall thickness. An abundance of neovessels with elevated expression of integrin αvβ3 is closely associated with an increased risk of plaque rupture. Herein we evaluated the potential of an αvβ3 integrin-targeting radiotracer, 99mTc-IDA-D-[c(RGDfK)]2, for SPECT/CT imaging of high-risk plaque in murine atherosclerosis models. In vivo uptake of 99mTc-IDA-D-[c(RGDfK)]2 was significantly higher in atherosclerotic aortas than in relatively normal aortas. Comparison with the negative-control peptide, 99mTc-IDA-D-[c(RADfK)]2, proved specific binding of 99mTc-IDA-D-[c(RGDfK)]2 for plaque lesions in in vivo SPECT/CT and ex vivo autoradiographic imaging. Histopathological characterization revealed that a prominent SPECT signal of 99mTc-IDA-D-[c(RGDfK)]2 corresponded to the presence of high-risk plaques with a large necrotic core, a thin fibrous cap, and vibrant neoangiogenic events. Notably, the RGD dimer based 99mTc-IDA-D-[c(RGDfK)]2 showed better imaging performance in comparison with the common monomeric RGD peptide probe 123I-c(RGDyV) and fluorescence tissue assay corroborated this. Our preclinical data demonstrated that 99mTc-IDA-D-[c(RGDfK)]2 SPECT/CT is a sensitive tool to noninvasively gauge atherosclerosis beyond vascular anatomy by assessing culprit plaque neovascularization. PMID:26123253

  18. Hybrid SPECT/CT imaging in neurology.

    PubMed

    Ciarmiello, Andrea; Giovannini, Elisabetta; Meniconi, Martina; Cuccurullo, Vincenzo; Gaeta, Maria Chiara

    2014-01-01

    In recent years, the SPECT/CT hybrid modality has led to a rapid development of imaging techniques in nuclear medicine, opening new perspectives for imaging staff and patients as well. However, while, the clinical role of positron emission tomography-computed tomography (PET-CT) is well consolidated, the diffusion and the consequent value of single-photon emission tomography-computed tomography (SPECT-CT) has yet to be weighed, Hence, there is a need for a careful analysis, comparing the "potential" benefits of the hybrid modality with the "established" ones of the standalone machine. The aim of this article is to analyze the impact of this hybrid tool on the diagnosis of diseases of the central nervous system, comparing strengths and weaknesses of both modalities through the use of SWOT analysis. PMID:25143053

  19. SPECT/CT in pediatric patient management.

    PubMed

    Nadel, Helen R

    2014-05-01

    Hybrid SPECT/CT imaging is becoming the standard of care in pediatric imaging. Indications are mainly for oncologic imaging including mIBG scintigraphy for neuroblastoma and I-123 post surgical imaging of children with thyroid carcinoma, bone scintigraphy for back pain, children referred from sports medicine and neurodevelopmentally delayed children presenting with pain symptoms. The studies provide improved diagnostic accuracy, and oncologic imaging that includes optimized CT as part of the SPECT/CT study may decrease the number of studies and sedation procedures an individual child may need. The studies, however, must be tailored on an individual basis as the addition of the CT study can increase exposure to the child and should only be performed after appropriate justification and with adherence to optimized low dose pediatric protocols. PMID:24554052

  20. Accelerated GPU based SPECT Monte Carlo simulations.

    PubMed

    Garcia, Marie-Paule; Bert, Julien; Benoit, Didier; Bardiès, Manuel; Visvikis, Dimitris

    2016-06-01

    Monte Carlo (MC) modelling is widely used in the field of single photon emission computed tomography (SPECT) as it is a reliable technique to simulate very high quality scans. This technique provides very accurate modelling of the radiation transport and particle interactions in a heterogeneous medium. Various MC codes exist for nuclear medicine imaging simulations. Recently, new strategies exploiting the computing capabilities of graphical processing units (GPU) have been proposed. This work aims at evaluating the accuracy of such GPU implementation strategies in comparison to standard MC codes in the context of SPECT imaging. GATE was considered the reference MC toolkit and used to evaluate the performance of newly developed GPU Geant4-based Monte Carlo simulation (GGEMS) modules for SPECT imaging. Radioisotopes with different photon energies were used with these various CPU and GPU Geant4-based MC codes in order to assess the best strategy for each configuration. Three different isotopes were considered: (99m) Tc, (111)In and (131)I, using a low energy high resolution (LEHR) collimator, a medium energy general purpose (MEGP) collimator and a high energy general purpose (HEGP) collimator respectively. Point source, uniform source, cylindrical phantom and anthropomorphic phantom acquisitions were simulated using a model of the GE infinia II 3/8" gamma camera. Both simulation platforms yielded a similar system sensitivity and image statistical quality for the various combinations. The overall acceleration factor between GATE and GGEMS platform derived from the same cylindrical phantom acquisition was between 18 and 27 for the different radioisotopes. Besides, a full MC simulation using an anthropomorphic phantom showed the full potential of the GGEMS platform, with a resulting acceleration factor up to 71. The good agreement with reference codes and the acceleration factors obtained support the use of GPU implementation strategies for improving computational

  1. Accelerated GPU based SPECT Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Garcia, Marie-Paule; Bert, Julien; Benoit, Didier; Bardiès, Manuel; Visvikis, Dimitris

    2016-06-01

    Monte Carlo (MC) modelling is widely used in the field of single photon emission computed tomography (SPECT) as it is a reliable technique to simulate very high quality scans. This technique provides very accurate modelling of the radiation transport and particle interactions in a heterogeneous medium. Various MC codes exist for nuclear medicine imaging simulations. Recently, new strategies exploiting the computing capabilities of graphical processing units (GPU) have been proposed. This work aims at evaluating the accuracy of such GPU implementation strategies in comparison to standard MC codes in the context of SPECT imaging. GATE was considered the reference MC toolkit and used to evaluate the performance of newly developed GPU Geant4-based Monte Carlo simulation (GGEMS) modules for SPECT imaging. Radioisotopes with different photon energies were used with these various CPU and GPU Geant4-based MC codes in order to assess the best strategy for each configuration. Three different isotopes were considered: 99m Tc, 111In and 131I, using a low energy high resolution (LEHR) collimator, a medium energy general purpose (MEGP) collimator and a high energy general purpose (HEGP) collimator respectively. Point source, uniform source, cylindrical phantom and anthropomorphic phantom acquisitions were simulated using a model of the GE infinia II 3/8" gamma camera. Both simulation platforms yielded a similar system sensitivity and image statistical quality for the various combinations. The overall acceleration factor between GATE and GGEMS platform derived from the same cylindrical phantom acquisition was between 18 and 27 for the different radioisotopes. Besides, a full MC simulation using an anthropomorphic phantom showed the full potential of the GGEMS platform, with a resulting acceleration factor up to 71. The good agreement with reference codes and the acceleration factors obtained support the use of GPU implementation strategies for improving computational efficiency

  2. Perioperative Assessment of Myocardial Deformation

    PubMed Central

    Duncan, Andra E.; Alfirevic, Andrej; Sessler, Daniel I.; Popovic, Zoran B.; Thomas, James D.

    2014-01-01

    Evaluation of left ventricular performance improves risk assessment and guides anesthetic decisions. However, the most common echocardiographic measure of myocardial function, the left ventricular ejection fraction (LVEF), has important limitations. LVEF is limited by subjective interpretation which reduces accuracy and reproducibility, and LVEF assesses global function without characterizing regional myocardial abnormalities. An alternative objective echocardiographic measure of myocardial function is thus needed. Myocardial deformation analysis, which performs quantitative assessment of global and regional myocardial function, may be useful for perioperative care of surgical patients. Myocardial deformation analysis evaluates left ventricular mechanics by quantifying strain and strain rate. Strain describes percent change in myocardial length in the longitudinal (from base to apex) and circumferential (encircling the short-axis of the ventricle) direction and change in thickness in the radial direction. Segmental strain describes regional myocardial function. Strain is a negative number when the ventricle shortens longitudinally or circumferentially and is positive with radial thickening. Reference values for normal longitudinal strain from a recent meta-analysis using transthoracic echocardiography are (mean ± SD) −19.7 ± 0.4%, while radial and circumferential strain are 47.3 ± 1.9 and −23.3 ± 0.7%, respectively. The speed of myocardial deformation is also important and is characterized by strain rate. Longitudinal systolic strain rate in healthy subjects averages −1.10 ± 0.16 sec−1. Assessment of myocardial deformation requires consideration of both strain (change in deformation), which correlates with LVEF, and strain rate (speed of deformation), which correlates with rate of rise of left ventricular pressure (dP/dt). Myocardial deformation analysis also evaluates ventricular relaxation, twist, and untwist, providing new and noninvasive methods to

  3. Reconstruction of dynamic gated cardiac SPECT

    SciTech Connect

    Jin Mingwu; Yang Yongyi; King, Michael A.

    2006-11-15

    In this paper we propose an image reconstruction procedure which aims to unify gated single photon emission computed tomography (SPECT) and dynamic SPECT into a single method. We divide the cardiac cycle into a number of gate intervals as in gated SPECT, but treat the tracer distribution for each gate as a time-varying signal. By using both dynamic and motion-compensated temporal regularization, our reconstruction procedure will produce an image sequence that shows both cardiac motion and time-varying tracer distribution simultaneously. To demonstrate the proposed reconstruction method, we simulated gated cardiac perfusion imaging using the gated mathematical cardiac-torso (gMCAT) phantom with Tc99m-Teboroxime as the imaging agent. Our results show that the proposed method can produce more accurate reconstruction of gated dynamic images than independent reconstruction of individual gate frames with spatial smoothness alone. In particular, our results show that the former could improve the contrast to noise ratio of a simulated perfusion defect by as much as 100% when compared to the latter.

  4. SPECT detectors: the Anger Camera and beyond

    PubMed Central

    Peterson, Todd E.; Furenlid, Lars R.

    2011-01-01

    The development of radiation detectors capable of delivering spatial information about gamma-ray interactions was one of the key enabling technologies for nuclear medicine imaging and, eventually, single-photon emission computed tomography (SPECT). The continuous NaI(Tl) scintillator crystal coupled to an array of photomultiplier tubes, almost universally referred to as the Anger Camera after its inventor, has long been the dominant SPECT detector system. Nevertheless, many alternative materials and configurations have been investigated over the years. Technological advances as well as the emerging importance of specialized applications, such as cardiac and preclinical imaging, have spurred innovation such that alternatives to the Anger Camera are now part of commercial imaging systems. Increased computing power has made it practical to apply advanced signal processing and estimation schemes to make better use of the information contained in the detector signals. In this review we discuss the key performance properties of SPECT detectors and survey developments in both scintillator and semiconductor detectors and their readouts with an eye toward some of the practical issues at least in part responsible for the continuing prevalence of the Anger Camera in the clinic. PMID:21828904

  5. SPECT detectors: the Anger Camera and beyond.

    PubMed

    Peterson, Todd E; Furenlid, Lars R

    2011-09-01

    The development of radiation detectors capable of delivering spatial information about gamma-ray interactions was one of the key enabling technologies for nuclear medicine imaging and, eventually, single-photon emission computed tomography (SPECT). The continuous sodium iodide scintillator crystal coupled to an array of photomultiplier tubes, almost universally referred to as the Anger Camera after its inventor, has long been the dominant SPECT detector system. Nevertheless, many alternative materials and configurations have been investigated over the years. Technological advances as well as the emerging importance of specialized applications, such as cardiac and preclinical imaging, have spurred innovation such that alternatives to the Anger Camera are now part of commercial imaging systems. Increased computing power has made it practical to apply advanced signal processing and estimation schemes to make better use of the information contained in the detector signals. In this review we discuss the key performance properties of SPECT detectors and survey developments in both scintillator and semiconductor detectors and their readouts with an eye toward some of the practical issues at least in part responsible for the continuing prevalence of the Anger Camera in the clinic. PMID:21828904

  6. SPECT detectors: the Anger Camera and beyond

    NASA Astrophysics Data System (ADS)

    Peterson, Todd E.; Furenlid, Lars R.

    2011-09-01

    The development of radiation detectors capable of delivering spatial information about gamma-ray interactions was one of the key enabling technologies for nuclear medicine imaging and, eventually, single-photon emission computed tomography (SPECT). The continuous sodium iodide scintillator crystal coupled to an array of photomultiplier tubes, almost universally referred to as the Anger Camera after its inventor, has long been the dominant SPECT detector system. Nevertheless, many alternative materials and configurations have been investigated over the years. Technological advances as well as the emerging importance of specialized applications, such as cardiac and preclinical imaging, have spurred innovation such that alternatives to the Anger Camera are now part of commercial imaging systems. Increased computing power has made it practical to apply advanced signal processing and estimation schemes to make better use of the information contained in the detector signals. In this review we discuss the key performance properties of SPECT detectors and survey developments in both scintillator and semiconductor detectors and their readouts with an eye toward some of the practical issues at least in part responsible for the continuing prevalence of the Anger Camera in the clinic.

  7. Methodology for ventilation/perfusion SPECT.

    PubMed

    Bajc, Marika; Neilly, Brian; Miniati, Massimo; Mortensen, Jan; Jonson, Björn

    2010-11-01

    Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices in all projections as well as in rotating volume images based upon maximum intensity projections. Probabilistic interpretation of V/Q SPECT should be replaced by a holistic interpretation strategy on the basis of all relevant information about the patient and all ventilation/perfusion patterns. PE is diagnosed when there is more than one subsegment showing a V/Q mismatch representing an anatomic lung unit. Apart from pulmonary embolism, other pathologies should be identified and reported, for example, obstructive disease, heart failure, and pneumonia. Pitfalls exist both with respect to imaging technique and scan interpretation. PMID:20920632

  8. Pulsed Doppler tissue imaging for the assessment of myocardial viability: comparison with 99mTc sestamibi perfusion imaging.

    PubMed

    Minamihaba, O; Takeishi, Y; Hirono, O; Yamauchi, S; Arimoto, T; Fukui, A; Okuyama, M; Nozaki, N; Akiyama, H; Fatema, K; Miyamoto, T; Takahashi, H; Fujiwara, S; Okada, A; Takahashi, K; Kubota, I

    2002-12-01

    The aim of the present study was to examine whether Doppler tissue imaging demonstrated comparable diagnostic performance for the detection of viable myocardium compared to myocardial perfusion imaging with Tc hexakis-2-methoxyisobutylisonitrile (MIBI). We studied 30 patients with old myocardial infarction who underwent percutaneous transluminal coronary angioplasty (PTCA). Myocardial single photon emission computed tomography (SPECT) with Tc-MIBI and two-dimensional echocardiography were carried out within 7 days before PTCA. We measured regional Tc-MIBI uptake for each myocardial segment from SPECT and peak systolic velocity and a ratio of regional pre-ejection period to regional ejection time (PEP/ET) from pulsed Doppler tissue imaging. Biplane left ventriculography was performed before interventional procedures and repeated 3 months after PTCA. Myocardial viability was determined when wall motion was improved at least one grade after PTCA. The peak systolic velocity was positively correlated with regional Tc-MIBI uptake (R =0.59, P<0.01). The PEP/ET demonstrated inverse correlation with Tc-MIBI uptake ( R=-0.59, P<0.01). Peak systolic velocity of viable segments was higher than that of non-viable segments ( P<0.05). The PEP/ET was lower in viable segments than in non-viable segments ( P<0.05). Peak systolic velocity and PEP/ET demonstrated high diagnostic accuracy for detecting viable myocardium compared with Tc-MIBI perfusion imaging (80% and 79% vs 90%). These data indicate that measurements of regional peak systolic velocity and PEP/ET by Doppler tissue imaging are useful for evaluating myocardial viability quantitatively and provide helpful information for a clinical judgment in an interventional strategy. PMID:12464785

  9. SPECT data acquisition and image reconstruction in a stationary small animal SPECT/MRI system

    NASA Astrophysics Data System (ADS)

    Xu, Jingyan; Chen, Si; Yu, Jianhua; Meier, Dirk; Wagenaar, Douglas J.; Patt, Bradley E.; Tsui, Benjamin M. W.

    2010-04-01

    The goal of the study was to investigate data acquisition strategies and image reconstruction methods for a stationary SPECT insert that can operate inside an MRI scanner with a 12 cm bore diameter for simultaneous SPECT/MRI imaging of small animals. The SPECT insert consists of 3 octagonal rings of 8 MR-compatible CZT detectors per ring surrounding a multi-pinhole (MPH) collimator sleeve. Each pinhole is constructed to project the field-of-view (FOV) to one CZT detector. All 24 pinholes are focused to a cylindrical FOV of 25 mm in diameter and 34 mm in length. The data acquisition strategies we evaluated were optional collimator rotations to improve tomographic sampling; and the image reconstruction methods were iterative ML-EM with and without compensation for the geometric response function (GRF) of the MPH collimator. For this purpose, we developed an analytic simulator that calculates the system matrix with the GRF models of the MPH collimator. The simulator was used to generate projection data of a digital rod phantom with pinhole aperture sizes of 1 mm and 2 mm and with different collimator rotation patterns. Iterative ML-EM reconstruction with and without GRF compensation were used to reconstruct the projection data from the central ring of 8 detectors only, and from all 24 detectors. Our results indicated that without GRF compensation and at the default design of 24 projection views, the reconstructed images had significant artifacts. Accurate GRF compensation substantially improved the reconstructed image resolution and reduced image artifacts. With accurate GRF compensation, useful reconstructed images can be obtained using 24 projection views only. This last finding potentially enables dynamic SPECT (and/or MRI) studies in small animals, one of many possible application areas of the SPECT/MRI system. Further research efforts are warranted including experimentally measuring the system matrix for improved geometrical accuracy, incorporating the co

  10. [Estimation of destruction of necrotic myocardium with serial PYP SPECT images and serum myosin light chain I level].

    PubMed

    Tanaka, T; Aizawa, T; Kato, K; Hosoi, H

    1992-02-01

    PYP SPECT images were underwent in 15 patients with acute myocardial infarction 2-5 times in three weeks. PYP SPECT images were reconstructed as to include both vertebral images and myocardial images. Quantitative estimation of PYP images was performed by the ratio of maximal PYP myocardial uptake to maximal PYP vertebral uptake in the central sagittal images (%PYP). Disappearance of PYP images was defined as the day, when %PYP reached 50%. Normalization of serum myosin light chain I (LCI) level was defined as the day, when LCI level reached 2.5 ng/ml. %PYP decreased continuously and maximal PYP point remained at the same area. Shape of PYP images varied and diminished. In case of anterior wall infarction apical PYP uptake persisted longer than basal uptake. In case of inferior wall infarction basal PYP uptake persisted longer than apical uptake. The mean period from onset to the disappearance of PYP images was 9 +/- 3 days. Pattern of serial serum MB level was simple, however corresponding pattern of serial serum LCI level showed various types. The mean period from onset to the peak level was 4.1 +/- 1 day. Normalization of LCI level was 9.3 +/- 2.9 days. It showed that process of destruction of necrotic myocardium vary in each case. Weak relation was noted between disappearance of PYP images (DAY-PYP) and normalization of LCI level (DAY-LCI). DAY-PYP = 4.4 +/- 0.46 DAY-LCI (n = 13, r = 0.4). Quantitative PYP images were useful for detecting ongoing necrotic myocardium and serum LCI level was useful for estimating destruction of necrotic myocardium.2+ level were useful to study the process of destruction of necrotic myocardium. PMID:1532996

  11. Complete improvement in a patient with multiple irreversible defects of the left ventricle on 99m technetium-sestamibi SPECT after percutaneous coronary intervention.

    PubMed

    Javadi, H; Porpiranfar, M A; Semnani, S; Jallalat, S; Yavari, P; Mogharrabi, M; Hooman, A; Amini, A; Barekat, M; Iranpour, D; Assadi, M; Asli, I N

    2012-10-01

    99mTc-sestamibi has been investigated as a potential viability marker; initial studies have shown good concordance between 201Tl and 99mTc-sestamibi activities in both viable and nonviable myocardium. However, assessment of myocardial viability by 99mTc-sestamibi remains controversial for tissue recovery after revascularization. Here, we present a patient with several regions of severely diminished and irreversible (defect persisting in both early and delay images of each set scanning) defects on initial scan which were dissolved completely on the follow up scan after an intervention. In a 75 year-old Asian woman with acute myocardial infarction who received thrombolytic therapy and subjected to percutaneous coronary angiography (PCI) on day 28 after acute myocardial infarction(MI), resting 99mTc-sestamibi SPECT was applied on day 4 (initial scan) and 138 (follow up scan) after acute MI at 30 and 180 min after injection of tracer (740 MBq); Two-dimensional echocardiography was carried out at the same time. On the initial image set, there was irreversible defects in the apex, anteroapical, inferoapical, anteroseptal, septal and also anterior walls, while the follow up image was normal in all regions.The angiography intervention showed just significant stenosis on left anterior descending (LAD) vessel (95%). This may highlight the failure of 99mTc-sestamibi as a marker of myocardial viability and also mandate further validating of the procedure with follow up scan or other modalities for myocardial viability investigation. PMID:23090825

  12. Prediction of functional recovery and prognosis in patients with acute myocardial infarction by 123I-BMIPP and 201Tl myocardial single photon emission computed tomography: a multicenter trial.

    PubMed

    Nishimura, T; Nishimura, S; Kajiya, T; Sugihara, H; Kitahara, K; Imai, K; Muramatsu, T; Takahashi, N; Yoshida, H; Osada, T; Terada, K; Ito, T; Naruse, H; Iwabuchi, M

    1998-10-01

    123I-BMIPP [15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid] was developed for metabolic imaging with SPECT. A multicenter collaborative study was conducted on a large patient series to determine whether 123I-BMIPP and 201Tl myocardial SPECT are of use in predicting the prognosis and ventricular function after acute myocardial infarction (AMI). Patients with uncomplicated first AMI underwent resting 123I-BMIPP and 201Tl myocardial SPECT in the subacute phase after the onset of AMI. Of these, 167 patients who had been followed up for an average of 22 months were retrospectively reviewed to predict serious cardiac events and recurrent ischemia. In addition, the association between changes in radionuclide parameters and recurrent ischemia was investigated in Subgroup A (58 patients) who had repeated SPECT in the chronic phase. Furthermore, prediction of the ejection fraction (EF) was investigated in Subgroup B (94 patients) and Subgroup C (76 patients) in whom left ventriculography was performed at the time of discharge and 90 days or more after the onset, respectively. The prognosis was generally favorable, with 4 cases of cardiac death (2%), 3 of heart failure (2%), 4 of nonfatal reMI (2%), and 25 of recurrent ischemia (15%). The results of Cox multivariate regression analysis revealed a high probability of serious cardiac events in patients who were elderly (p = 0.04), who had 90% or more residual stenosis of the infarct-related artery (p = 0.09), and who had a high BMIPP defect score (p = 0.17). There was a high probability of recurrent ischemia in elderly patients (p = 0.10) who had multi-vessel disease (p = 0.03), but no association was found with radionuclide parameters in the subacute phase. In Subgroup A, however, the probability of recurrent ischemia tended to be high in patients with a large mismatch scorebetween 123I-BMIPP and 201Tl in the subacute to chronic phase. An important observation was that the extent of BMIPP defect was more strongly

  13. A partial defect in technetium-99m pyrophosphate image suggesting cardiac rupture following acute myocardial infarction.

    PubMed

    Tsujino, M; Hiroe, M; Sugimoto, K; Miyahara, Y; Ishii, Z; Taniguchi, K; Marumo, F

    1992-01-01

    We present the case of a 70-year-old woman with acute myocardial infarction who died of cardiac rupture on the 2nd hospital day. Dual isotope single photon emission computed tomography (SPECT) using thallium-201 chloride and technetium-99m pyrophosphate (PYP) performed on the 2nd hospital day showed a large perfusion defect in the anteroseptal wall on 201Tl image and a increased accumulation on 99mTc-PYP image in the anterior area consistent with a partial defect. Autopsy performed 1 h after death revealed a tear in the left ventricular anterior wall consistent with the defect on the 99mTc-PYP image. We propose that the finding of a partial defect in 99mTc-PYP is an interesting finding which may be associated with cardiac rupture following acute myocardial infarction. PMID:1533369

  14. Assessment of a Monte-Carlo simulation of SPECT recordings from a new-generation heart-centric semiconductor camera: from point sources to human images.

    PubMed

    Imbert, Laetitia; Galbrun, Ernest; Odille, Freddy; Poussier, Sylvain; Noel, Alain; Wolf, Didier; Karcher, Gilles; Marie, Pierre-Yves

    2015-02-01

    Geant4 application for tomographic emission (GATE), a Monte-Carlo simulation platform, has previously been used for optimizing tomoscintigraphic images recorded with scintillation Anger cameras but not with the new-generation heart-centric cadmium-zinc-telluride (CZT) cameras. Using the GATE platform, this study aimed at simulating the SPECT recordings from one of these new CZT cameras and to assess this simulation by direct comparison between simulated and actual recorded data, ranging from point sources to human images. Geometry and movement of detectors, as well as their respective energy responses, were modeled for the CZT 'D.SPECT' camera in the GATE platform. Both simulated and actual recorded data were obtained from: (1) point and linear sources of (99m)Tc for compared assessments of detection sensitivity and spatial resolution, (2) a cardiac insert filled with a (99m)Tc solution for compared assessments of contrast-to-noise ratio and sharpness of myocardial borders and (3) in a patient with myocardial infarction using segmented cardiac magnetic resonance imaging images. Most of the data from the simulated images exhibited high concordance with the results of actual images with relative differences of only: (1) 0.5% for detection sensitivity, (2) 6.7% for spatial resolution, (3) 2.6% for contrast-to-noise ratio and 5.0% for sharpness index on the cardiac insert placed in a diffusing environment. There was also good concordance between actual and simulated gated-SPECT patient images for the delineation of the myocardial infarction area, although the quality of the simulated images was clearly superior with increases around 50% for both contrast-to-noise ratio and sharpness index. SPECT recordings from a new heart-centric CZT camera can be simulated with the GATE software with high concordance relative to the actual physical properties of this camera. These simulations may be conducted up to the stage of human SPECT-images even if further refinement is needed

  15. Quantitative Monte Carlo-based holmium-166 SPECT reconstruction

    SciTech Connect

    Elschot, Mattijs; Smits, Maarten L. J.; Nijsen, Johannes F. W.; Lam, Marnix G. E. H.; Zonnenberg, Bernard A.; Bosch, Maurice A. A. J. van den; Jong, Hugo W. A. M. de; Viergever, Max A.

    2013-11-15

    Purpose: Quantitative imaging of the radionuclide distribution is of increasing interest for microsphere radioembolization (RE) of liver malignancies, to aid treatment planning and dosimetry. For this purpose, holmium-166 ({sup 166}Ho) microspheres have been developed, which can be visualized with a gamma camera. The objective of this work is to develop and evaluate a new reconstruction method for quantitative {sup 166}Ho SPECT, including Monte Carlo-based modeling of photon contributions from the full energy spectrum.Methods: A fast Monte Carlo (MC) simulator was developed for simulation of {sup 166}Ho projection images and incorporated in a statistical reconstruction algorithm (SPECT-fMC). Photon scatter and attenuation for all photons sampled from the full {sup 166}Ho energy spectrum were modeled during reconstruction by Monte Carlo simulations. The energy- and distance-dependent collimator-detector response was modeled using precalculated convolution kernels. Phantom experiments were performed to quantitatively evaluate image contrast, image noise, count errors, and activity recovery coefficients (ARCs) of SPECT-fMC in comparison with those of an energy window-based method for correction of down-scattered high-energy photons (SPECT-DSW) and a previously presented hybrid method that combines MC simulation of photopeak scatter with energy window-based estimation of down-scattered high-energy contributions (SPECT-ppMC+DSW). Additionally, the impact of SPECT-fMC on whole-body recovered activities (A{sup est}) and estimated radiation absorbed doses was evaluated using clinical SPECT data of six {sup 166}Ho RE patients.Results: At the same noise level, SPECT-fMC images showed substantially higher contrast than SPECT-DSW and SPECT-ppMC+DSW in spheres ≥17 mm in diameter. The count error was reduced from 29% (SPECT-DSW) and 25% (SPECT-ppMC+DSW) to 12% (SPECT-fMC). ARCs in five spherical volumes of 1.96–106.21 ml were improved from 32%–63% (SPECT-DSW) and 50%–80

  16. Evaluation of right and left ventricular function by quantitative blood-pool SPECT (QBS): comparison with conventional methods and quantitative gated SPECT (QGS).

    PubMed

    Odagiri, Keiichi; Wakabayashi, Yasushi; Tawarahara, Kei; Kurata, Chinori; Urushida, Tsuyoshi; Katoh, Hideki; Satoh, Hiroshi; Hayashi, Hideharu

    2006-10-01

    Though quantitative ECG-gated blood-pool SPECT (QBS) has become a popular tool in research settings, more verification is necessary for its utilization in clinical medicine. To evaluate the reliability of the measurements of left and right ventricular functions with QBS, we performed QBS, as well as first-pass pool (FPP) and ECG-gated blood-pool (GBP) studies on planar images in 41 patients and 8 healthy volunteers. Quantitative ECG-gated myocardial perfusion SPECT (QGS) was also performed in 30 of 49 subjects. First, we assessed the reproducibility of the measurements of left and right ventricular ejection fraction (LVEF, RVEF) and left and right ventricular end-diastolic volume (LVEDV, RVEDV) with QBS. Second, LVEF and RVEF obtained from QBS were compared with those from FPP and GBP, respectively. Third, LVEF and LVEDV obtained from QBS were compared with those from QGS, respectively. The intra- and inter-observer reproducibilities were excellent for LVEF, LVEDV, RVEF and RVEDV measured with QBS (r = 0.88 to 0.96, p < 0.01), while the biases in the measurements of RVEF and RVEDV were relatively large. LVEF obtained from QBS correlated significantly with those from FPP and GBP, while RVEF from QBS did not. LVEF and LVEDV obtained from QBS were significantly correlated with those from QGS, but the regression lines were not close to the lines of identity. In conclusion, the measurements of LVEF and LVEDV with QBS have good reproducibility and are useful clinically, while those of RVEF and RVEDV are less useful compared with LVEF and LVEDV. The algorithm of QBS for the measurements of RVEF and RVEDV remains to be improved. PMID:17134018

  17. Acute myocardial infarction.

    PubMed

    Rischpler, Christoph

    2016-09-01

    Inflammatory processes after myocardial infarction have gained major interest in recent cardiovascular research. It is believed that not only the degree of cell recruitment to the heart plays a pivotal role in the quality of wound healing after myocardial infarction, but also the balance between different types or even subtypes of cells. It is also this balance which is thought to control key processes in tissue repair, such as apoptosis and neoangiogenesis. In this paper, we aim to review imaging strategies (with a special focus on nuclear molecular imaging strategies) that target cells and processes involved in postischemic inflammation and that have a high potential to be translated into clinic or that are already being used and evaluated in humans. PMID:27225319

  18. A small-animal imaging system capable of multipinhole circular/helical SPECT and parallel-hole SPECT

    PubMed Central

    Qian, Jianguo; Bradley, Eric L.; Majewski, Stan; Popov, Vladimir; Saha, Margaret S.; Smith, Mark F.; Weisenberger, Andrew G.; Welsh, Robert E.

    2008-01-01

    We have designed and built a small animal single photon emission computed tomography (SPECT) imaging system equipped with parallel-hole and multipinhole collimators and capable of circular or helical SPECT. Copper-beryllium parallel-hole collimators suitable for imaging the ~35 keV photons from the decay of 125I have been built and installed to achieve useful spatial resolution over a range of object-detector distances and to reduce imaging time on our dual-detector array. To address the resolution limitations in the parallel-hole SPECT and the sensitivity and limited field of view of single-pinhole SPECT, we have incorporated multipinhole circular and helical SPECT in addition to expanding the parallel-hole SPECT capabilities. The pinhole SPECT system is based on a 110 mm diameter circular detector equipped with a pixellated NaI(Tl) scintillator array (1×1×5 mm3/pixel). The helical trajectory is accomplished by two stepping motors controlling the rotation of the detector-support gantry and displacement of the animal bed along the axis of rotation of the gantry. Results obtained in SPECT studies of various phantoms show an enlarged field of view, very good resolution and improved sensitivity using multipinhole circular or helical SPECT. Collimators with one, three and five 1 mm diameter pinholes have been implemented and compared in these tests. Our objective is to develop a system on which one may readily select a suitable mode of either parallel-hole SPECT or pinhole circular or helical SPECT for a variety of small animal imaging applications. PMID:19701447

  19. A small-animal imaging system capable of multipinhole circular/helical SPECT and parallel-hole SPECT

    NASA Astrophysics Data System (ADS)

    Qian, Jianguo; Bradley, Eric L.; Majewski, Stan; Popov, Vladimir; Saha, Margaret S.; Smith, Mark F.; Weisenberger, Andrew G.; Welsh, Robert E.

    2008-08-01

    We have designed and built a small-animal single-photon emission computed tomography (SPECT) imaging system equipped with parallel-hole and multipinhole collimators and capable of circular or helical SPECT. Copper-beryllium parallel-hole collimators suitable for imaging the ˜35 keV photons from the decay of 125I have been built and installed to achieve useful spatial resolution over a range of object-detector distances and to reduce imaging time on our dual-detector array. To address the resolution limitations in the parallel-hole SPECT and the sensitivity and limited field of view of single-pinhole SPECT, we have incorporated multipinhole circular and helical SPECT in addition to expanding the parallel-hole SPECT capabilities. The pinhole SPECT system is based on a 110 mm diameter circular detector equipped with a pixellated NaI(Tl) scintillator array (1×1×5 mm 3/pixel). The helical trajectory is accomplished by two stepping motors controlling the rotation of the detector-support gantry and displacement of the animal bed along the axis of rotation of the gantry. Results obtained in SPECT studies of various phantoms show an enlarged field of view, very good resolution and improved sensitivity using multipinhole circular or helical SPECT. Collimators with one, three and five, 1-mm-diameter pinholes have been implemented and compared in these tests. Our objective is to develop a system on which one may readily select a suitable mode of either parallel-hole SPECT or pinhole circular or helical SPECT for a variety of small animal imaging applications.

  20. Interobserver variation in diagnosis of dementia by brain perfusion SPECT.

    PubMed

    Honda, Norinari; Machida, Kikuo; Hosono, Makoto; Matsumoto, Tohru; Matsuda, Hiroshi; Oshima, Motoo; Koizumi, Kiyoshi; Kosuda, Shigeru; Momose, Toshimitsu; Mori, Yutaka; Hashimoto, Jun; Shimizu, Yuji

    2002-01-01

    Brain perfusion SPECT (BP-SPECT) has characteristic patterns of abnormality, enabling the differential diagnosis of dementia. The purpose of this study was to measure interobserver variations in the diagnosis of dementia using BP-SPECT. BP-SPECT images of 57 cases, 19 of Alzheimer's disease (AD), eight of multi-infarct dementia (MID), three of Pick's disease, five of other dementias, and 22 normal controls, were interpreted by ten nuclear medicine physicians with varying levels of experience. Brain MR images of the cases were then interpreted apart from SPECT. The physicians independently rated all of the diagnoses listed beforehand according to a five-point scale, with clinical information provided. Receiver-operating characteristic (ROC) curves and the area under the ROC curve (Az) were calculated. Az varied from 0.48 to 0.87. Mean Az's were significantly larger (p<0.05) in the diagnosis by SPECT than in that by MRI (0.715 and 0.629 for dementia vs. normal, 0.670 and 0.560 for AD or MID vs. normal, 0.610 and 0.416 for AD vs. normal, and 0.672 and 0.412 for AD vs. MID, respectively). Considerable interobserver variation was present in BP-SPECT interpretation. BP-SPECT may be more effective for the evaluation of dementia than MRI when the same nuclear medicine physicians interpret both images. PMID:12553341

  1. Severe fever with thrombocytopenia syndrome with myocardial dysfunction and encephalopathy: A case report.

    PubMed

    Kawaguchi, Takeshi; Matsuda, Motohiro; Takajo, Ichiro; Kawano, Ayako; Kariya, Yumi; Kubo, Kazuyoshi; Miyauchi, Syunichi; Umekita, Kunihiko; Nagatomo, Yasuhiro; Yano, Takao; Yano, Kouji; Okayama, Akihiko

    2016-09-01

    Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease in China, Korea and Japan caused by a novel bunyavirus, SFTS virus (SFTSV). Although central nervous system manifestations are common in SFTS patients, the pathogenesis has not been elucidated; and there are few reports of myocardial dysfunction. Here we report an elderly Japanese patient with reversible myocardial dysfunction and encephalopathy. A previously healthy 65-year-old male engaged in forestry got a tick bite and developed fever and fatigue in 3 days. Three days after onset, he presented to a local hospital where the diagnosis of SFTS with hemophagocytotic syndrome was made. The blood test showed leukopenia and thrombocytopenia as well as elevated levels of alanine aminotransferase and aspartate aminotransferase. Marked hemophagocytosis was found on bone marrow smear. Peripheral blood was positive for SFTSV gene by reverse-transcription polymerase chain reaction. On day 7, the patient was transferred to our hospital. We observed disturbance of consciousness, Kernig sign and myoclonus to face and limbs. Decreased blood flow of whole cerebral cortex was detected by single photon emission computed tomography (SPECT). Chest X-ray revealed cardiomegaly and electrocardiography (ECG) showed abnormal T waves. These data suggested acute encephalopathy and myocardial dysfunction. We treated him with corticosteroid and blood transfusion, which resulted in the complete recovery of the above abnormal symptoms and laboratory data including the findings in SPECT and ECG in about a month. This case demonstrated transient myocardial dysfunction and encephalopathy can occur in addition to typical clinical manifestation of SFTS. PMID:26943978

  2. Patient doses from hybrid SPECT-CT procedures.

    PubMed

    Avramova-Cholakova, S; Dimcheva, M; Petrova, E; Garcheva, M; Dimitrova, M; Palashev, Y; Vassileva, J

    2015-07-01

    The aim of this work is to estimate patient doses from hybrid single-photon emission computed tomography (SPECT) and computed tomography (CT) procedures. The study involved all four SPECT-CT systems in Bulgaria. Effective dose was estimated for about 100 patients per system. Ten types of examinations were considered, representing all diagnostic procedures performed in the SPECT-CT systems. Effective doses from the SPECT component were calculated applying the ICRP 53 and ICRP 80 conversion coefficients. Computed tomography dose index and dose length product were retrospectively obtained from the archives of the systems, and effective doses from the CT component were calculated with CT-Expo software. Parallel estimation of CT component contribution with the National Radiological Protection Board (NRPB) conversion coefficients was performed where applicable. Large variations were found in the current practice of SPECT-CT imaging. Optimisation actions and diagnostic reference levels were proposed. PMID:25862537

  3. Single photon emission computed tomography (SPECT) in epilepsy

    SciTech Connect

    Leroy, R.F.

    1991-12-31

    Epilepsy is a common neurologic disorder which has just begun to be studied with single photon emission computerized tomography (SPECT). Epilepsy usually is studied with electroencephalographic (EEG) techniques that demonstrate the physiologic changes that occur during seizures, and with neuroimaging techniques that show the brain structures where seizures originate. Neither method alone has been adequate to describe the pathophysiology of the patient with epilepsy. EEG techniques lack anatomic sensitivity, and there are no structural abnormalities shown by neuroimaging which are specific for epilepsy. Functional imaging (FI) has developed as a physiologic tool with anatomic sensitivity, and SPECT has been promoted as a FI technique because of its potentially wide availability. However, SPECT is early in its development and its clinical utility for epilepsy still has to be demonstrated. To understand this role of SPECT, consideration must be given to the pathophysiology of epilepsy, brain physiology, types of seizure, epileptic syndromes, and the SPECT technique itself. 44 refs., 2 tabs.

  4. [Mortality of myocardial infarction].

    PubMed

    Bonnefoy, E; Kirkorian, G

    2011-12-01

    Coronary disease is a major cause of death and disability. From 1975 to 2000, coronary mortality was reduced by half. Better treatments and reduction of risk factors are the main causes. This phenomenon is observed in most developed countries, but mortality from coronary heart disease continues to increase in developing countries. In-hospital mortality of ST elevation myocardial infarction (STEMI) is in the range of 7 to 10% in registries. In infarction without ST segment elevation (NSTEMI), in-hospital mortality is around 5%. More recent studies found a similar in-hospital mortality for STEMI and NSTEMI. Because of patient selection and monitoring, mortality in clinical trials is much lower. After adjustment for the extent of coronary disease, age, risk factors, history of myocardial infarction, the excess mortality observed in women is fading. Many clinical, biological and laboratory parameters are associated with mortality in myocardial infarction. They refer to the immediate risk of death (ventricular rhythm disturbances, shock…), the extent of infarction (number of leads with ST elevation on the ECG, release of biomarkers, ejection fraction…), the presence of heart failure, the failure of reperfusion and the patient's baseline risk (age, renal function…). Risk scores, and more specifically the GRACE risk score, synthesize these different markers to predict the risk of death in a given patient. However, their use for the treatment of myocardial only concerns NSTEMI. Only a limited number of mechanical or pharmacological interventions reduces mortality of heart attack. The main benefits are observed with reperfusion by thrombolysis or primary angioplasty in STEMI, aspirin, heparin, beta-blockers, angiotensin converting enzyme inhibitors. Some medications such as bivalirudin and fondaparinux reduce mortality by decreasing the incidence of hemorrhagic complications. The guidelines classify interventions according to their benefit and especially their ability

  5. System Integration of FastSPECT III, a Dedicated SPECT Rodent-Brain Imager Based on BazookaSPECT Detector Technology

    PubMed Central

    Miller, Brian W.; Furenlid, Lars R.; Moore, Stephen K.; Barber, H. Bradford; Nagarkar, Vivek V.; Barrett, Harrison H.

    2010-01-01

    FastSPECT III is a stationary, single-photon emission computed tomography (SPECT) imager designed specifically for imaging and studying neurological pathologies in rodent brain, including Alzheimer’s and Parkinsons’s disease. Twenty independent BazookaSPECT [1] gamma-ray detectors acquire projections of a spherical field of view with pinholes selected for desired resolution and sensitivity. Each BazookaSPECT detector comprises a columnar CsI(Tl) scintillator, image-intensifier, optical lens, and fast-frame-rate CCD camera. Data stream back to processing computers via firewire interfaces, and heavy use of graphics processing units (GPUs) ensures that each frame of data is processed in real time to extract the images of individual gamma-ray events. Details of the system design, imaging aperture fabrication methods, and preliminary projection images are presented. PMID:21218137

  6. Longitudinal myocardial blood flow gradient and CAD detection.

    PubMed

    Valenta, Ines; Wahl, Richard L; Schindler, Thomas H

    2015-01-01

    Conventional myocardial perfusion scintigraphy with SPECT/CT or with PET/CT has been established as pivotal clinical imaging modality for the identification of hemodynamically obstructive coronary artery disease (CAD) and risk stratification of patients with suspected or known CAD. While the assessment of the relative distribution of radiotracer uptake in the left-ventricular (LV) myocardium during vasomotor stress identifies the "culprit" or most severe CAD lesion in multivessel disease, flow-limiting effects of remaining but less severe epicardial lesions may be missed. This limitation principally may be overcome by the possibility of PET/CT with radiotracer-kinetic modeling to concurrently assess left-ventricular (LV) myocardial blood flow (MBF) in ml/g/min at rest and during vasomotor stress and the resulting myocardial flow reserve (MFR). While a stress-induced regional reduction in radiotracer uptake or perfusion identifies the most advanced epicardial lesion, flow-limiting effects of the other epicardial lesions may principally be identified by regional reductions in MFR. Conversely, reductions in MFR in CAD may be appreciated as suboptimal as they reflect not only the consequences of flow-limiting effects of epicardial stenosis but also of microvascular dysfunction. The relatively low specificity of a reduced therefore MFR may hamper a clear identification of the downstream hemodynamic effects of an epicardial lesion on hyperemic coronary flow increases. In this scenario, there is increasing evidence that the PET assessment of an abnormal decrease in MBF from the base to the apex of the LV during hyperemic flows, a so-called longitudinal flow gradient, is primarily related to fluid dynamic consequences of CAD-induced diffuse luminal and/or focal narrowing of the epicardial artery. The combined evaluation of the MFR and corresponding longitudinal MBF gradient could emerge as new a novel analytic concept to further optimize the identification and

  7. Diurnal variations in myocardial metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The heart is challenged by a plethora of extracellular stimuli over the course of a normal day, each of which distinctly influences myocardial contractile function. It is therefore not surprising that myocardial metabolism also oscillates in a time-of-day dependent manner. What is becoming increasin...

  8. Dipyridamole thallium-201 myocardial scintigraphy

    SciTech Connect

    Not Available

    1988-09-01

    Thallium-201 (/sup 201/Tl) myocardial scintigraphy is a sensitive technique for detecting coronary artery disease. Standardized exercise testing is the most common method for inducing myocardial stress for /sup 201/Tl imaging. Unfortunately, a significant number of patients are unable to undergo adequate treadmill or bicycle exercise. In these patients, pharmacologic stress with dipyridamole provides a safe, efficacious, and reliable alternative.

  9. Advances in SPECT in evaluating coronary disease.

    PubMed

    Kelion, Andrew D

    2014-07-01

    Myocardial perfusion scintigraphy is the longest established of the functional imaging investigations for patients with known or suspected coronary artery disease. This article describes recent technical and clinical advances that are ensuring that the technique remains relevant some 40 years after its first introduction. PMID:25040515

  10. Efficacy of coronary artery bypass surgery with gastroepiploic artery. Assessment with thallium 201 myocardial scintigraphy

    SciTech Connect

    Kusukawa, J.; Hirota, Y.; Kawamura, K.; Suma, H.; Takeuchi, A.; Adachi, I.; Akagi, H. )

    1989-09-01

    This study describes the efficacy of the right gastroepiploic artery (GEA) as graft material for coronary artery bypass grafting (CABG) as assessed by exercise thallium 201 myocardial scintigraphy in eight patients (age, 59.4 {plus minus} 9.35 years (mean {plus minus} SD)) who underwent CABG with the GEA graft in the past 2 years. Planar and single-photon-emission computed tomographic (SPECT) images were obtained during and 3 hours after exercise. Planar images were evaluated quantitatively with the percentile-washout method, and SPECT images were evaluated qualitatively with a bull's-eye, polar-coordinate map. All patients had triple-vessel disease, and in situ GEAs were anastomosed to the right coronary artery in seven patients and to the left anterior descending coronary artery in one. The internal mammary artery graft was concomitantly used in all patients. The mean number of grafts per patient was 3.0 (range, 2-4). Preoperative exercise testing could not be performed in two patients because of emergency operation. By qualitative assessment with the polar-coordinate map, four patients showed improvement, one did not show any change, and one became worse due to perioperative myocardial infarction.

  11. Spiral MR myocardial tagging.

    PubMed

    Ryf, Salome; Kissinger, Kraig V; Spiegel, Marcus A; Börnert, Peter; Manning, Warren J; Boesiger, Peter; Stuber, Matthias

    2004-02-01

    In the present study, complementary spatial modulation of magnetization (CSPAMM) myocardial tagging was extended with an interleaved spiral imaging sequence. The use of a spiral sequence enables the acquisition of grid-tagged images with a tagline distance as low as 4 mm in a single breath-hold. Alternatively, a high temporal resolution of 77 frames per second was obtained with 8-mm grid spacing. Ten healthy adult subjects were studied. With this new approach, high-quality images can be obtained and the tags persist throughout the entire cardiac cycle. PMID:14755646

  12. Assessment of myocardial viability.

    PubMed

    Travin, Mark I; Bergmann, Steven R

    2005-01-01

    The prevalence of left ventricular (LV) dysfunction and resultant congestive heart failure is increasing. Patients with this condition are at high risk for cardiac death and usually have significant limitations in their lifestyles. Although there have been advances in medical therapy resulting in improved survival and well being, the best and most definitive therapy, when appropriate, is revascularization. In the setting of coronary artery disease, accounting for approximately two thirds of cases of congestive heart failure, LV dysfunction often is not the result of irreversible scar but rather caused by impairment in function and energy use of still viable-myocytes, with the opportunity for improved function if coronary blood flow is restored. Patients with LV dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischemia but at the same time benefit most from revascularization. It is important to identify viable myocardium in these patients, and radionuclide myocardial scintigraphy is an excellent tool for this. Single-photon emission computed tomography perfusion scintigraphy, whether using thallium-201, Tc-99m sestamibi, or Tc-99m tetrofosmin, in stress and/or rest protocols, has consistently been shown to be an effective modality for identifying myocardial viability and guiding appropriate management. Metabolic imaging with positron emission tomography radiotracers frequently adds additional information and is a powerful tool for predicting which patients will have an improved outcome from revascularization, including some patients referred instead for cardiac transplantation. Other noninvasive modalities, such as stress echocardiography, also facilitate the assessment of myocardial viability, but there are advantages and disadvantages compared with the nuclear techniques. Nuclear imaging appears to require fewer viable cells for detection, resulting in a higher sensitivity but a lower specificity than stress

  13. Proceedings of clinical SPECT (single photon emission computed tomography) symposium

    SciTech Connect

    Not Available

    1986-09-01

    It has been five years since the last in-depth American College of Nuclear Physicians/Society of Nuclear Medicine Symposium on the subject of single photon emission computed tomography (SPECT) was held. Because this subject was nominated as the single most desired topic we have selected SPECT imaging as the basis for this year's program. The objectives of this symposium are to survey the progress of SPECT clinical applications that have taken place over the last five years and to provide practical and timely guidelines to users of SPECT so that this exciting imaging modality can be fully integrated into the evaluation of pathologic processes. The first half was devoted to a consideration of technical factors important in SPECT acquisition and the second half was devoted to those organ systems about which sufficient clinical SPECT imaging data are available. With respect to the technical aspect of the program we have selected the key areas which demand awareness and attention in order to make SPECT operational in clinical practice. These include selection of equipment, details of uniformity correction, utilization of phantoms for equipment acceptance and quality assurance, the major aspect of algorithms, an understanding of filtered back projection and appropriate choice of filters and an awareness of the most commonly generated artifacts and how to recognize them. With respect to the acquisition and interpretation of organ images, the faculty will present information on the major aspects of hepatic, brain, cardiac, skeletal, and immunologic imaging techniques. Individual papers are processed separately for the data base. (TEM)

  14. SPECT/CT Fusion in the Diagnosis of Hyperparathyroidism

    PubMed Central

    Monzen, Yoshio; Tamura, Akihisa; Okazaki, Hajime; Kurose, Taichi; Kobayashi, Masayuki; Kuraoka, Masatsugu

    2015-01-01

    Objective(s): In this study, we aimed to analyze the relationship between the diagnostic ability of fused single photon emission computed tomography/ computed tomography (SPECT/CT) images in localization of parathyroid lesions and the size of adenomas or hyperplastic glands. Methods: Five patients with primary hyperparathyroidism (PHPT) and 4 patients with secondary hyperparathyroidism (SHPT) were imaged 15 and 120 minutes after the intravenous injection of technetium99m-methoxyisobutylisonitrile (99mTc-MIBI). All patients underwent surgery and 5 parathyroid adenomas and 10 hyperplastic glands were detected. Pathologic findings were correlated with imaging results. Results: The SPECT/CT fusion images were able to detect all parathyroid adenomas even with the greatest axial diameter of 0.6 cm. Planar scintigraphy and SPECT imaging could not detect parathyroid adenomas with an axial diameter of 1.0 to 1.2 cm. Four out of 10 (40%) hyperplastic parathyroid glands were diagnosed, using planar and SPECT imaging and 5 out of 10 (50%) hyperplastic parathyroid glands were localized, using SPECT/CT fusion images. Conclusion: SPECT/CT fusion imaging is a more useful tool for localization of parathyroid lesions, particularly parathyroid adenomas, in comparison with planar and or SPECT imaging.

  15. Detection models for freehand SPECT reconstruction

    NASA Astrophysics Data System (ADS)

    Hartl, Alexander; Shakir, Dzhoshkun I.; Lasser, Tobias; Ziegler, Sibylle I.; Navab, Nassir

    2015-02-01

    Nuclear imaging modalities are commonly used tools in today’s diagnostics and therapy planning. However for interventional use they suffer from drawbacks which limit their application. Freehand SPECT was developed to provide 3D functional imaging during interventions. It combines a nuclear detector with an optical tracking system to obtain its position and orientation in space and synchronizes this with the detector readings. This information can be used to compute a 3D tomographic reconstruction of an activity distribution of a nuclear tracer. As there is no fixed geometry, the system matrix has to be computed on the fly. This is done with models of the detection process for completely arbitrary freehand acquisitions. The accuracy of the reconstructions is highly dependent on the used models of the detection process. Different models of the detection process were developed and evaluated in this work, in particular two analytical models as well as lookup tables generated from either real measurements or Monte Carlo simulations. We showed that it is possible to perform acceptable reconstructions with a simple but efficient analytical model. The use of lookup tables to generate the system matrix in Freehand SPECT is a fast solution with good accuracy.

  16. Advances in SPECT and PET Hardware.

    PubMed

    Slomka, Piotr J; Pan, Tinsu; Berman, Daniel S; Germano, Guido

    2015-01-01

    There have been significant recent advances in single photon emission computed tomography (SPECT) and positron emission tomography (PET) hardware. Novel collimator designs, such as multi-pinhole and locally focusing collimators arranged in geometries that are optimized for cardiac imaging have been implemented to reduce imaging time and radiation dose. These new collimators have been coupled with solid state photon detectors to further improve image quality and reduce scanner size. The new SPECT scanners demonstrate up to a 7-fold increase in photon sensitivity and up to 2 times improvement in image resolution. Although PET scanners are used primarily for oncological imaging, cardiac imaging can benefit from the improved PET sensitivity of 3D systems without inter-plane septa and implementation of the time-of-flight reconstruction. Additionally, resolution recovery techniques are now implemented by all major PET vendors. These new methods improve image contrast, image resolution, and reduce image noise. Simultaneous PET/magnetic resonance (MR) hybrid systems have been developed. Solid state detectors with avalanche photodiodes or digital silicon photomultipliers have also been utilized in PET. These new detectors allow improved image resolution, higher count rate, as well as a reduced sensitivity to electromagnetic MR fields. PMID:25721706

  17. Detection models for freehand SPECT reconstruction.

    PubMed

    Hartl, Alexander; Shakir, Dzhoshkun I; Lasser, Tobias; Ziegler, Sibylle I; Navab, Nassir

    2015-02-01

    Nuclear imaging modalities are commonly used tools in today's diagnostics and therapy planning. However for interventional use they suffer from drawbacks which limit their application. Freehand SPECT was developed to provide 3D functional imaging during interventions. It combines a nuclear detector with an optical tracking system to obtain its position and orientation in space and synchronizes this with the detector readings. This information can be used to compute a 3D tomographic reconstruction of an activity distribution of a nuclear tracer. As there is no fixed geometry, the system matrix has to be computed on the fly. This is done with models of the detection process for completely arbitrary freehand acquisitions. The accuracy of the reconstructions is highly dependent on the used models of the detection process. Different models of the detection process were developed and evaluated in this work, in particular two analytical models as well as lookup tables generated from either real measurements or Monte Carlo simulations. We showed that it is possible to perform acceptable reconstructions with a simple but efficient analytical model. The use of lookup tables to generate the system matrix in Freehand SPECT is a fast solution with good accuracy. PMID:25585618

  18. Bone SPECT/CT of Femoral Head Subchondral Insufficiency Fracture.

    PubMed

    Motomura, Goro; Yamamoto, Takuaki; Karasuyama, Kazuyuki; Iwamoto, Yukihide

    2015-09-01

    Subchondral insufficiency fracture of the femoral head may be confused with osteonecrosis, mainly because of radiological overlap. SPECT/CT with Tc-99 m hydroxymethylene diphosphonate images in 7 patients with subchondral insufficiency fracture were retrospectively reviewed and compared with those from 11 patients with symptomatic early osteonecrosis. In all of the hips with subchondral insufficiency fracture, SPECT/CT showed increased uptake at the subchondral lesions of the femoral head. On the other hand, in all of the hips with osteonecrosis, absence of uptake was confirmed at the subchondral lesions. SPECT/CT may assist in differentiating subchondral insufficiency fracture from osteonecrosis. PMID:26164176

  19. Fabrication of the pinhole aperture for AdaptiSPECT

    PubMed Central

    Kovalsky, Stephen; Kupinski, Matthew A.; Barrett, Harrison H.; Furenlid, Lars R.

    2015-01-01

    AdaptiSPECT is a pre-clinical pinhole SPECT imaging system under final construction at the Center for Gamma-Ray Imaging. The system is designed to be able to autonomously change its imaging configuration. The system comprises 16 detectors mounted on translational stages to move radially away and towards the center of the field-of-view. The system also possesses an adaptive pinhole aperture with multiple collimator diameters and pinhole sizes, as well as the possibility to switch between multiplexed and non-multiplexed imaging configurations. In this paper, we describe the fabrication of the AdaptiSPECT pinhole aperture and its controllers. PMID:26146443

  20. Valsartan after myocardial infarction.

    PubMed

    Güleç, Sadi

    2014-12-01

    One of the important problems of the patients undergoing acute myocardial infarction (MI) is early development of heart failure. It has been revealed in various studies that renin-angiotensin-aldosterone system (RAAS) has a significant role in this process. The studies conducted with angiotensin converting enzyme (ACE) inhibitors have resulted in decreased mortality rate. Another RAAS blocker which was discovered about ten years later than other ACE inhibitors in historical process is angiotensin receptor blockers (ARB) inhibiting the efficiency of angiotensin 2 by binding to angiotensin 1 receptor. Valsartan is one of the molecules of this group, which has higher number of large-scale randomized clinical studies. In this review, following presentation of a general overview on heart failure after acute MI, the efficiency of ARBs in this patient group will be discussed. This discussion will mostly emphasize the construction, outcomes and clinical importance of VALIANT (VALsartan In Acute myocardial iNfarcTion), which is the study on valsartan after acute MI heart failure. PMID:25604205

  1. Trauma Induced Myocardial Infarction

    PubMed Central

    Lolay, Georges A.; Abdel-Latef, Ahmed K.

    2016-01-01

    Chest Trauma in athletes is a common health problem. However, myocardial infarction secondary to coronary dissection in the setting of blunt chest trauma is extremely rare. We report a case of acute inferior wall myocardial infarction following blunt chest trauma. A 32-year-old male with no relevant medical problems was transferred to our medical center for retrosternal chest pain after being elbowed in the chest during a soccer game. Few seconds later, he started experiencing sharp retrosternal chest pain that was severe to that point where he called the emergency medical service. Upon arrival to the Trauma department patient was still complaining of chest pain. ECG demonstrated ST segment elevation in the inferior leads with reciprocal changes in the lateral leads all consistent with active ischemia. After rolling out Aortic dissection, patient was loaded with ASA, ticagerlor, heparin and was emergently taken to the cardiac catheterization lab. Coronary angiography demonstrated 100% thrombotic occlusion in the distal right coronary artery with TIMI 0 flow distally. After thrombus aspiration, a focal dissection was noted on the angiogram that was successfully stented. Two days after admission patient was discharged home. Echocardiography prior to discharge showed inferior wall akinesis, normal right ventricular systolic function and normal overall ejection fraction. PMID:26490501

  2. Dynamic molecular imaging of cardiac innervation using a dual headpinhole SPECT system

    SciTech Connect

    Hu, Jicun; Boutchko, Rostyslav; Sitek, Arkadiusz; Reutter, BryanW.; Huesman, Ronald H.; Gullberg, Grant T.

    2008-03-29

    Typically 123I-MIBG is used for the study of innervation andfunction of the sympathetic nervous system in heart failure. The protocolinvolves two studies: first a planar or SPECT scan is performed tomeasure initial uptake of the tracer, followed some 3-4 hours later byanother study measuring the wash-out of the tracer from the heart. A fastwash-out is indicative of a compromised heart. In this work, a dual headpinhole SPECT system was used for imaging the distribution and kineticsof 123I-MIBG in the myocardium of spontaneous hypertensive rats (SHR) andnormotensive Wistar Kyoto (WKY) rats. The system geometry was calibratedbased on a nonlinear point projection fitting method using a three-pointsource phantom. The angle variation effect of the parameters was modeledwith a sinusoidal function. A dynamic acquisition was performed byinjecting 123I-MIBG into rats immediately after starting the dataacquisition. The detectors rotated continuously performing a 360o dataacquisition every 90 seconds. We applied the factor analysis (FA)methodand region of interest (ROI) sampling method to obtain time activitycurves (TACs)in the blood pool and myocardium and then appliedtwo-compartment modeling to estimate the kinetic parameters. Since theinitial injection bolus is too fast for obtaining a consistenttomographic data set in the first few minutes of the study, we appliedthe FA method directly to projections during the first rotation. Then thetime active curves for blood and myocardial tissue were obtained from ROIsampling. The method was applied to determine if there were differencesin the kinetics between SHR and WKY rats and requires less time byreplacing the delayed scan at 3-4 hours after injection with a dynamicacquisition over 90 to 120 minutes. The results of a faster washout and asmaller distribution volume of 123IMIBG near the end of life in the SHRmodel of hypertrophic cardiomyopthy may be indicative of a failing heartin late stages of heart failure.

  3. Design and development of MR-compatible SPECT systems for simultaneous SPECT-MR imaging of small animals

    NASA Astrophysics Data System (ADS)

    Tsui, Benjamin M. W.; Hugg, James W.; Xu, Jingyan; Chen, Si; Meier, Dirk; Edelstein, William; El-Sharkawy, Abdel; Wagenaar, Douglas J.; Patt, Bradley E.

    2011-03-01

    We describe a continuing design and development of MR-compatible SPECT systems for simultaneous SPECT-MR imaging of small animals. A first generation prototype SPECT system was designed and constructed to fit inside a MRI system with a gradient bore inner diameter of 12 cm. It consists of 3 angularly offset rings of 8 detectors (1"x1", 16x16 pixels MR-compatible solid-state CZT). A matching 24-pinhole collimator sleeve, made of a tungsten-compound, provides projections from a common FOV of ~25 mm. A birdcage RF coil for MRI data acquisition surrounds the collimator. The SPECT system was tested inside a clinical 3T MRI system. Minimal interference was observed on the simultaneously acquired SPECT and MR images. We developed a sparse-view image reconstruction method based on accurate modeling of the point response function (PRF) of each of the 24 pinholes to provide artifact-free SPECT images. The stationary SPECT system provides relatively low resolution of 3-5 mm but high geometric efficiency of 0.5- 1.2% for fast dynamic acquisition, demonstrated in a SPECT renal kinetics study using Tc-99m DTPA. Based on these results, a second generation prototype MR-compatible SPECT system with an outer diameter of 20 cm that fits inside a mid-sized preclinical MRI system is being developed. It consists of 5 rings of 19 CZT detectors. The larger ring diameter allows the use of optimized multi-pinhole collimator designs, such as high system resolution up to ~1 mm, high geometric efficiency, or lower system resolution without collimator rotation. The anticipated performance of the new system is supported by simulation data.

  4. FastSPECT II: A Second-Generation High-Resolution Dynamic SPECT Imager

    PubMed Central

    Furenlid, Lars R.; Wilson, Donald W.; Chen, Yi-chun; Kim, Hyunki; Pietraski, Philip J.; Crawford, Michael J.; Barrett, Harrison H.

    2010-01-01

    FastSPECT II is a recently commissioned 16-camera small-animal SPECT imager built with modular scintillation cameras and list-mode data-acquisition electronics. The instrument is housed in a lead-shielded enclosure and has exchangeable aperture assemblies and adjustable camera positions for selection of magnification, pinhole size, and field of view. The calibration of individual cameras and measurement of an overall system imaging matrix (1 mm3 voxels) are supported via a five-axis motion-control system. Details of the system integration and results of characterization and performance measurements are presented along with first tomographic images. The dynamic imaging capabilities of the instrument are explored and discussed. PMID:20877439

  5. Value of thallium-201 reinjection after delayed SPECT imaging for predicting reversible ischemia after coronary artery bypass grafting

    SciTech Connect

    Ohtani, H.; Tamaki, N.; Yonekura, Y.; Mohiuddin, I.H.; Hirata, K.; Ban, T.; Konishi, J. )

    1990-08-15

    The reinjection of a small dose (40 MBq) of thallium-201 after stress and delayed imaging often shows new redistribution in the regions with persistent defect. To assess whether these segments may represent reversible ischemia, reinjection thallium-201 single-photon emission computed tomography (SPECT) was performed after stress and 3-hour delayed imaging in 24 patients before coronary artery bypass grafting (CABG). The left ventricular myocardium was divided into 5 myocardial segments and regional wall motion was scored on a scale from 0 (normal) to 4 (dyskinesia). Thallium-201 findings were compared with improvement in regional perfusion and wall motion 1 to 2 months after CABG. The reinjection imaging identified new redistribution in 15 of 32 persistent defects (47%) on the 3-hour delayed images. In the study of stress and delayed SPECT imaging, the improvement in perfusion was observed in 34 of 43 segments (79%) exhibiting redistribution and 15 of 32 (47%) segments without redistribution (p less than 0.01). The reinjection SPECT identified new redistribution in 12 of the 15 improved segments that were not detected on the delayed images. Similarly, the improvement in wall motion was observed in 23 of 31 segments (74%) exhibiting redistribution and 14 of 30 segments (47%) without redistribution on the delayed images (p less than 0.05). The reinjection identified new redistribution in 10 of the 14 improved segments that were undetected on the delayed images. The predictive values for improvement in perfusion and wall motion by the reinjection imaging were significantly higher (92 and 89%) than those by the delayed imaging (69 and 62%, respectively, p less than 0.05 each).

  6. Assessment of a Monte-Carlo simulation of SPECT recordings from a new-generation heart-centric semiconductor camera: from point sources to human images

    NASA Astrophysics Data System (ADS)

    Imbert, Laetitia; Galbrun, Ernest; Odille, Freddy; Poussier, Sylvain; Noel, Alain; Wolf, Didier; Karcher, Gilles; Marie, Pierre-Yves

    2015-02-01

    Geant4 application for tomographic emission (GATE), a Monte-Carlo simulation platform, has previously been used for optimizing tomoscintigraphic images recorded with scintillation Anger cameras but not with the new-generation heart-centric cadmium-zinc-telluride (CZT) cameras. Using the GATE platform, this study aimed at simulating the SPECT recordings from one of these new CZT cameras and to assess this simulation by direct comparison between simulated and actual recorded data, ranging from point sources to human images. Geometry and movement of detectors, as well as their respective energy responses, were modeled for the CZT ‘D.SPECT’ camera in the GATE platform. Both simulated and actual recorded data were obtained from: (1) point and linear sources of 99mTc for compared assessments of detection sensitivity and spatial resolution, (2) a cardiac insert filled with a 99mTc solution for compared assessments of contrast-to-noise ratio and sharpness of myocardial borders and (3) in a patient with myocardial infarction using segmented cardiac magnetic resonance imaging images. Most of the data from the simulated images exhibited high concordance with the results of actual images with relative differences of only: (1) 0.5% for detection sensitivity, (2) 6.7% for spatial resolution, (3) 2.6% for contrast-to-noise ratio and 5.0% for sharpness index on the cardiac insert placed in a diffusing environment. There was also good concordance between actual and simulated gated-SPECT patient images for the delineation of the myocardial infarction area, although the quality of the simulated images was clearly superior with increases around 50% for both contrast-to-noise ratio and sharpness index. SPECT recordings from a new heart-centric CZT camera can be simulated with the GATE software with high concordance relative to the actual physical properties of this camera. These simulations may be conducted up to the stage of human SPECT-images even if further refinement is needed

  7. Cardiac AAV9 Gene Delivery Strategies in Adult Canines: Assessment by Long-term Serial SPECT Imaging of Sodium Iodide Symporter Expression

    PubMed Central

    Moulay, Gilles; Ohtani, Tomohito; Ogut, Ozgur; Guenzel, Adam; Behfar, Atta; Zakeri, Rosita; Haines, Philip; Storlie, Jimmy; Bowen, Lorna; Pham, Linh; Kaye, David; Sandhu, Gurpreet; O'Connor, Michael; Russell, Stephen; Redfield, Margaret

    2015-01-01

    Heart failure is a leading cause of morbidity and mortality, and cardiac gene delivery has the potential to provide novel therapeutic approaches. Adeno-associated virus serotype 9 (AAV9) transduces the rodent heart efficiently, but cardiotropism, immune tolerance, and optimal delivery strategies in large animals are unclear. In this study, an AAV9 vector encoding canine sodium iodide symporter (NIS) was administered to adult immunocompetent dogs via epicardial injection, coronary infusion without and with cardiac recirculation, or endocardial injection via a novel catheter with curved needle and both end- and side-holes. As NIS mediates cellular uptake of clinical radioisotopes, expression was tracked by single-photon emission computerized tomography (SPECT) imaging in addition to Western blot and immunohistochemistry. Direct epicardial or endocardial injection resulted in strong cardiac expression, whereas expression after intracoronary infusion or cardiac recirculation was undetectable. A threshold myocardial injection dose that provides robust nonimmunogenic expression was identified. The extent of transmural myocardial expression was greater with the novel catheter versus straight end-hole needle delivery. Furthermore, the authors demonstrate that cardiac NIS reporter gene expression and duration can be quantified using serial noninvasive SPECT imaging up to 1 year after vector administration. These data are relevant to efforts to develop cardiac gene delivery as heart failure therapy. PMID:25915925

  8. Cardiac AAV9 Gene Delivery Strategies in Adult Canines: Assessment by Long-term Serial SPECT Imaging of Sodium Iodide Symporter Expression.

    PubMed

    Moulay, Gilles; Ohtani, Tomohito; Ogut, Ozgur; Guenzel, Adam; Behfar, Atta; Zakeri, Rosita; Haines, Philip; Storlie, Jimmy; Bowen, Lorna; Pham, Linh; Kaye, David; Sandhu, Gurpreet; O'Connor, Michael; Russell, Stephen; Redfield, Margaret

    2015-07-01

    Heart failure is a leading cause of morbidity and mortality, and cardiac gene delivery has the potential to provide novel therapeutic approaches. Adeno-associated virus serotype 9 (AAV9) transduces the rodent heart efficiently, but cardiotropism, immune tolerance, and optimal delivery strategies in large animals are unclear. In this study, an AAV9 vector encoding canine sodium iodide symporter (NIS) was administered to adult immunocompetent dogs via epicardial injection, coronary infusion without and with cardiac recirculation, or endocardial injection via a novel catheter with curved needle and both end- and side-holes. As NIS mediates cellular uptake of clinical radioisotopes, expression was tracked by single-photon emission computerized tomography (SPECT) imaging in addition to Western blot and immunohistochemistry. Direct epicardial or endocardial injection resulted in strong cardiac expression, whereas expression after intracoronary infusion or cardiac recirculation was undetectable. A threshold myocardial injection dose that provides robust nonimmunogenic expression was identified. The extent of transmural myocardial expression was greater with the novel catheter versus straight end-hole needle delivery. Furthermore, the authors demonstrate that cardiac NIS reporter gene expression and duration can be quantified using serial noninvasive SPECT imaging up to 1 year after vector administration. These data are relevant to efforts to develop cardiac gene delivery as heart failure therapy. PMID:25915925

  9. A geometric method of measuring the left ventricular ejection fraction on gated Tc-99m sestamibi myocardial imaging.

    PubMed

    Miron, S D; Finkelhor, R; Penuel, J H; Bahler, R; Bellon, E M

    1996-06-01

    Geometric measurements of the left ventricular diameters as used in biplane angiocardiography and echocardiography were applied to gated SPECT Tc-99m sestamibi myocardial scintigrams in order to calculate the left ventricular ejection fraction. These measurements take no longer than 5 minutes and require no additional computer software. In a review of 79 examinations, the left ventricular ejection fraction calculated using these measurements correlated well with the echocardiographically estimated ejection fraction (r = 0.78, P < 0.0001). The technique is highly reproducible with an intraobserver correlation of r = 0.94 and interobserver correlation of r = 0.93. PMID:8744176

  10. A Naive-Bayes model observer for detection and localization of perfusion defects in cardiac SPECT-MPI

    NASA Astrophysics Data System (ADS)

    Parages, Felipe M.; O'Connor, J. Michael; Pretorius, P. Hendrik; Brankov, Jovan G.

    2014-03-01

    Model observers (MO) are widely used in medical imaging to act as surrogates of human observers in task-based image quality evaluation, frequently towards optimization of reconstruction algorithms. In SPECT myocardial perfusion imaging (MPI), a realistic task-based approach involves detection and localization of perfusion defects, as well as a subsequent assessment of defect severity. In this paper we explore a machine-learning MO based on Naive- Bayes classification (NB-MO). NB-MO uses a set of polar-map image features to predict lesion detection, localization and severity scores given by five human readers for a set of simulated 3D SPECT-MPI patients. The simulated dataset included lesions with different sizes, perfusion-reduction ratios, and locations. Simulated projections were reconstructed using two readily used methods namely: FBP and OSEM. For validation, a multireader multi-case (MRMC) analysis of alternative free-response ROC (AFROC) curve was performed for NB-MO and human observers. For comparison, we also report performances of a statistical Hotelling Observer applied on polar-map images. Results show excellent agreement between NB-MO and humans, as well as model's good generalization between different reconstruction treatments.

  11. Taking the perfect nuclear image: quality control, acquisition, and processing techniques for cardiac SPECT, PET, and hybrid imaging.

    PubMed

    Case, James A; Bateman, Timothy M

    2013-10-01

    Nuclear Cardiology for the past 40 years has distinguished itself in its ability to non-invasively assess regional myocardial blood flow and identify obstructive coronary disease. This has led to advances in managing the diagnosis, risk stratification, and prognostic assessment of cardiac patients. These advances have all been predicated on the collection of high quality nuclear image data. National and international professional societies have established guidelines for nuclear laboratories to maintain high quality nuclear cardiology services. In addition, laboratory accreditation has further advanced the goal of the establishing high quality standards for the provision of nuclear cardiology services. This article summarizes the principles of nuclear cardiology single photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging and techniques for maintaining quality: from the calibration of imaging equipment to post processing techniques. It also will explore the quality considerations of newer technologies such as cadmium zinc telleride (CZT)-based SPECT systems and absolute blood flow measurement techniques using PET. PMID:23868070

  12. Performance evaluation of advanced industrial SPECT system with diverging collimator.

    PubMed

    Park, Jang Guen; Jung, Sung-Hee; Kim, Jong Bum; Moon, Jinho; Yeom, Yeon Soo; Kim, Chan Hyeong

    2014-12-01

    An advanced industrial SPECT system with 12-fold-array diverging collimator was developed for flow visualization in industrial reactors and was discussed in the previous study. The present paper describes performance evaluation of the SPECT system under both static- and dynamic- flow conditions. Under static conditions, the movement of radiotracer inside the test reactor was compared with that of color tracer (blue ink) captured with a high-speed camera. The comparison of the reconstructed images obtained with the radiotracer and the SPECT system showed fairly good agreement with video-frames of the color tracer obtained with the camera. Based on the results of the performance evaluation, it is concluded that the SPECT system is suitable for investigation and visualization of flows in industrial flow reactors. PMID:25169132

  13. Portal vein aneurysm demonstrated by blood pool SPECT.

    PubMed

    Fukui, H; Kashiwagi, T; Kimura, K; Goto, M; Takei, Y; Kasahara, A; Kawano, S; Fusamoto, H; Kozuka, T; Kamada, T

    1992-11-01

    Portal vein aneurysms are rare and are occasionally suggested by ultrasound and usually confirmed by invasive angiography. Such a case was diagnosed by scintigraphic studies, most importantly blood pool SPECT, which clearly separates it from hepatic cysts. PMID:1424375

  14. Sci—Thur PM: Imaging — 01: Position-sensitive noise characteristics in multi-pinhole cardiac SPECT imaging

    SciTech Connect

    Cuddy-Walsh, SG; Wells, RG

    2014-08-15

    Myocardial perfusion imaging (MPI) with Single Photon Emission Computed Tomography (SPECT) is invaluable in the diagnosis and management of heart disease. It provides essential information on myocardial blood flow and ischemia. Multi-pinhole dedicated cardiac-SPECT cameras offer improved count sensitivity, and spatial and energy resolutions over parallel-hole camera designs however variable sensitivity across the field-of-view (FOV) can lead to position-dependent noise variations. Since MPI evaluates differences in the signal-to-noise ratio, noise variations in the camera could significantly impact the sensitivity of the test for ischemia. We evaluated the noise characteristics of GE Healthcare's Discovery NM530c camera with a goal of optimizing the accuracy of our patient assessment and thereby improving outcomes. Theoretical sensitivity maps of the camera FOV, including attenuation effects, were estimated analytically based on the distance and angle between the spatial position of a given voxel and each pinhole. The standard deviation in counts, σ was inferred for each voxel position from the square root of the sensitivity mapped at that position. Noise was measured experimentally from repeated (N=16) acquisitions of a uniform spherical Tc-99m-water phantom. The mean (μ) and standard deviation (σ) were calculated for each voxel position in the reconstructed FOV. Noise increased ∼2.1× across a 12 cm sphere. A correlation of 0.53 is seen when experimental noise is compared with theory suggesting that ∼53% of the noise is attributed to the combined effects of attenuation and the multi-pinhole geometry. Further investigations are warranted to determine the clinical impact of the position-dependent noise variation.

  15. Cost-effectiveness of intracoronary flow velocity measurements and myocardial perfusion scintigraphy for management of intermediate coronary lesions

    PubMed Central

    Chamuleau, S.A.J.; Dijkgraaf, M.G.W.; van Eck-Smit, B.L.F.; Tijssen, J.G.P.; Piek, J.J.

    2005-01-01

    Background Coronary flow velocity reserve (CFVR) is an alternative for myocardial perfusion scintigraphy (SPECT) in assessing functional severity of coronary lesions. For the acceptance of CFVR in daily clinical decision-making, cost-effectiveness must be proven. Aim Economic evaluation of different diagnostic management strategies using CFVR compared with SPECT for making decisions regarding use of PTCA of an intermediate coronary lesion in patients with multivessel disease. Methods The incremental cost-effectiveness analysis was based on data from a prospective multicentre study in 201 patients with multivessel coronary artery disease. Four management strategies, assuming performance of angioplasty after positive test result(s), were compared: SPECT alone, CFVR alone (cut-off value of 2.0), and combined strategies of SPECT and CFVR with one ('extensive') or two ('restrictive') positive test(s). Probabilistic sensitivity analyses were performed using Monte Carlo simulation. Primary outcome was the probability of a cardiac event-free first year with respect to the intermediate lesion. Results A 10% event rate was observed, which was predominantly associated with ischaemia-driven revascularisations. A strategy based on CFVR was most effective. The restrictive strategy had the lowest costs and was most cost-effective; with increasing willingness-to-pay values (above €20,000) a CFVR-alone strategy became equally cost-effective. Conclusion It is mandatory to measure CFVR to decide upon angioplasty of the intermediate lesion in patients with multivessel coronary artery disease. This decision can be based on the restrictive strategy (i.e. performance of PTCA in case of abnormal test results of both SPECT and CFVR) or solely on CFVR, depending on society's willingness-to-pay to prevent cardiac events. ImagesFigure 3 PMID:25696495

  16. Comparison Between Postprocessing Software and Repeated Scanning to Eliminate Subdiaphragmatic Activity in Myocardial Perfusion Scintigraphy.

    PubMed

    Theerakulpisut, Daris; Chotipanich, Chanisa

    2016-01-01

    Myocardial perfusion single photon emission computed tomography (SPECT) is a powerful test of evaluation for coronary artery disease, but subdiaphragmatic radiotracer activity often interferes with the interpretation of inferior wall findings. This study aims to evaluate the effectiveness of using software elimination of the subdiaphragmatic activity for the assessment of its efficacy in the correctness of image interpretation and the overall image quality of myocardial perfusion scintigraphy (MPS). MPS studies from January 2010 to October 2012 at our institution were reviewed. Thirty-two SPECT studies were included, all of which had significant subdiaphragmatic activity in the first scan and needed to be delayed to let the activity clear. Each scan was interpreted by using semiquantitative scoring in 17 segments according to the degree of radiotracer uptake. The first scan, which had interfering activity, was manipulated by masking out the unwanted activity with software native to our image processing software suite. The manipulated images were then compared with delayed images of the same patient, of which the subdiaphragmatic activity was spontaneously cleared with time. The first scan masked by software correlated with the delayed scan for myocardial regions supplied by the left circumflex (LCx) and right coronary artery (RCA), but not the left anterior descending (LAD). However, the quality of the masked scans was perceived by the observer to be better in terms of quality and ease of interpretation. Using software to mask out unwanted subdiaphragmatic activity has no detrimental effect on the interpretation of MPS images when compared with delayed scanning, but it can improve subjective scan quality and ease of interpretation. PMID:27134559

  17. Comparison Between Postprocessing Software and Repeated Scanning to Eliminate Subdiaphragmatic Activity in Myocardial Perfusion Scintigraphy

    PubMed Central

    Theerakulpisut, Daris; Chotipanich, Chanisa

    2016-01-01

    Myocardial perfusion single photon emission computed tomography (SPECT) is a powerful test of evaluation for coronary artery disease, but subdiaphragmatic radiotracer activity often interferes with the interpretation of inferior wall findings. This study aims to evaluate the effectiveness of using software elimination of the subdiaphragmatic activity for the assessment of its efficacy in the correctness of image interpretation and the overall image quality of myocardial perfusion scintigraphy (MPS). MPS studies from January 2010 to October 2012 at our institution were reviewed. Thirty-two SPECT studies were included, all of which had significant subdiaphragmatic activity in the first scan and needed to be delayed to let the activity clear. Each scan was interpreted by using semiquantitative scoring in 17 segments according to the degree of radiotracer uptake. The first scan, which had interfering activity, was manipulated by masking out the unwanted activity with software native to our image processing software suite. The manipulated images were then compared with delayed images of the same patient, of which the subdiaphragmatic activity was spontaneously cleared with time. The first scan masked by software correlated with the delayed scan for myocardial regions supplied by the left circumflex (LCx) and right coronary artery (RCA), but not the left anterior descending (LAD). However, the quality of the masked scans was perceived by the observer to be better in terms of quality and ease of interpretation. Using software to mask out unwanted subdiaphragmatic activity has no detrimental effect on the interpretation of MPS images when compared with delayed scanning, but it can improve subjective scan quality and ease of interpretation. PMID:27134559

  18. Prognostic value of quantitative high-speed myocardial perfusion imaging

    PubMed Central

    Nakazato, Ryo; Berman, Daniel S.; Gransar, Heidi; Hyun, Mark; Miranda-Peats, Romalisa; Kite, Faith C.; Hayes, Sean W.; Thomson, Louise E.J.; Friedman, John D.; Rozanski, Alan; Slomka, Piotr J.

    2012-01-01

    Background Most studies have reported using semi-quantitative analysis to assess the prognostic utility of SPECT myocardial perfusion imaging (MPI). Thus we studied the prognostic value of fully automated quantitative analysis software applied to new solid-state, high-speed (HS) SPECT-MPI. Methods 1613 consecutive patients undergoing exercise or adenosine HS-MPI were followed for 2.6±0.5 years for all-cause mortality (ACM). Automated quantitative software was used for assessing stress total perfusion deficit (sTPD) and was compared to semi-quantitative visual analysis. MPI was characterized as 0% (normal); 1–4% (minimal perfusion defect); 5–10% (mildly abnormal); and >10% (moderately/severely abnormal). Results During follow-up, 79 patients died (4.9%). Annualized ACM increased with progressively increasing sTPD; 0% (0.87%), 1–4% (1.94%), 5–10% (3.10%) and >10% (5.33%) (log-rank p<0.0001). While similar overall findings were observed with visual analysis, only sTPD demonstrated increased risk in patients with minimal perfusion defects. In multivariable analysis, sTPD >10% was a mortality predictor (HR 3.03, 95% CI 1.30–7.09, p=0.01). Adjusted mortality rate was substantial in adenosine MPI, but low in exercise MPI (9.0% versus 1.0%, p<0.0001). Conclusions By quantitative analysis, ACM increases with increasing perfusion abnormality among patients undergoing stress HS-MPI. These findings confirm previous results obtained with visual analysis using conventional Anger camera imaging systems. PMID:23065414

  19. An unusual myocardial infarction

    PubMed Central

    Di Michele, Sara; Mirabelli, Francesca; Mankad, Sunil

    2014-01-01

    Summary We present a 74-year-old male with a chondrosarcoma, who presented with chest pain. The history, electrocardiogram (ECG), and biomarkers established the diagnosis of myocardial infarction (MI); angiography did not show coronary atherosclerosis and, both initial transthoracic echocardiogram and chest computed tomography (CT), did not demonstrate any cardiac abnormalities. A second echocardiogram following a routine ECG showed presence of a mass involving the right ventricle and the cardiac apex that was confirmed by chest CT scan. We underline the importance of considering cardiac tumors in the clinical arena of MI management. Learning points Cardiac tumors cause ECG changes similar to ischemic heart diseases.Keep in mind cardiac tumors when performing transthoracic echocardiogram (TTE) in the setting of suspected MI.TTE is the technique of choice in detecting cardiac tumors. PMID:26693309

  20. Masquerades of myocardial infarction.

    PubMed Central

    Bean, W. B.

    1976-01-01

    I summarize these observations in Figure 1. It represents every person in a hypothetical population who has myocardial infarction. A large but unknown number, some believe almost half, never get help. Mobile coronary care units are reducing this group, but so far only a little. When the diagnosis is not understood the disease is not recognized. Then come discovery and popularization. Hereafter masquerades hide some cases and the diagnosis is missed. Somewhere fairly early the diagnostic fad leads to false positive diagnosis. As new techniques are discovered, perfected and mastered, false positive errors and masquerades leading to oversights diminish but still exist. All the skill and technical virtuosity in the world will not be applied if we do not think of the disease. When we think of it, even obscure cases may be resolved easily. PMID:960416

  1. Cervical SPECT Camera for Parathyroid Imaging

    SciTech Connect

    None, None

    2012-08-31

    Primary hyperparathyroidism characterized by one or more enlarged parathyroid glands has become one of the most common endocrine diseases in the world affecting about 1 per 1000 in the United States. Standard treatment is highly invasive exploratory neck surgery called Parathyroidectomy. The surgery has a notable mortality rate because of the close proximity to vital structures. The move to minimally invasive parathyroidectomy is hampered by the lack of high resolution pre-surgical imaging techniques that can accurately localize the parathyroid with respect to surrounding structures. We propose to develop a dedicated ultra-high resolution (~ 1 mm) and high sensitivity (10x conventional camera) cervical scintigraphic imaging device. It will be based on a multiple pinhole-camera SPECT system comprising a novel solid state CZT detector that offers the required performance. The overall system will be configured to fit around the neck and comfortably image a patient.

  2. Iterative restoration of SPECT projection images

    SciTech Connect

    Glick, S.J.; Xia, W.

    1997-04-01

    Photon attenuation and the limited nonstationary spatial resolution of the detector can reduce both qualitative and quantitative image quality in single photon emission computed tomography (SPECT). In this paper, a reconstruction approach is described which can compensate for both of these degradations. The approach involves processing the project data with Bellini`s method for attenuation compensation followed by an iterative deconvolution technique which uses the frequency distance principle (FDP) to model the distance-dependent camera blur. Modeling of the camera blur with the FDP allows an efficient implementation using fast Fourier transformation (FFT) methods. After processing of the project data, reconstruction is performed using filtered backprojections. Simulation studies using two different brain phantoms show that this approach gives reconstructions with a favorable bias versus noise tradeoff, provides no visually undesirable noise artifacts, and requires a low computational load.

  3. SPECT Analysis of Cardiac Perfusion Changes After Whole-Breast/Chest Wall Radiation Therapy With or Without Active Breathing Coordinator: Results of a Randomized Phase 3 Trial

    SciTech Connect

    Zellars, Richard; Bravo, Paco E.; Tryggestad, Erik; Hopfer, Kari; Myers, Lee; Tahari, Abdel; Asrari, Fariba; Ziessman, Harvey; Garrett-Mayer, Elizabeth

    2014-03-15

    Purpose: Cardiac muscle perfusion, as determined by single-photon emission computed tomography (SPECT), decreases after breast and/or chest wall (BCW) irradiation. The active breathing coordinator (ABC) enables radiation delivery when the BCW is farther from the heart, thereby decreasing cardiac exposure. We hypothesized that ABC would prevent radiation-induced cardiac toxicity and conducted a randomized controlled trial evaluating myocardial perfusion changes after radiation for left-sided breast cancer with or without ABC. Methods and Materials: Stages I to III left breast cancer patients requiring adjuvant radiation therapy (XRT) were randomized to ABC or No-ABC. Myocardial perfusion was evaluated by SPECT scans (before and 6 months after BCW radiation) using 2 methods: (1) fully automated quantitative polar mapping; and (2) semiquantitative visual assessment. The left ventricle was divided into 20 segments for the polar map and 17 segments for the visual method. Segments were grouped by anatomical rings (apical, mid, basal) or by coronary artery distribution. For the visual method, 2 nuclear medicine physicians, blinded to treatment groups, scored each segment's perfusion. Scores were analyzed with nonparametric tests and linear regression. Results: Between 2006 and 2010, 57 patients were enrolled and 43 were available for analysis. The cohorts were well matched. The apical and left anterior descending coronary artery segments had significant decreases in perfusion on SPECT scans in both ABC and No-ABC cohorts. In unadjusted and adjusted analyses, controlling for pretreatment perfusion score, age, and chemotherapy, ABC was not significantly associated with prevention of perfusion deficits. Conclusions: In this randomized controlled trial, ABC does not appear to prevent radiation-induced cardiac perfusion deficits.

  4. Quantification of infarct size by /sup 201/Tl single-photon emission computed tomography during acute myocardial infarction in humans. Comparison with enzymatic estimates

    SciTech Connect

    Mahmarian, J.J.; Pratt, C.M.; Borges-Neto, S.; Cashion, W.R.; Roberts, R.; Verani, M.S.

    1988-10-01

    We prospectively investigated whether /sup 201/Tl single-photon emission computed tomography (SPECT) could accurately diagnose the presence and quantify the extent of acute myocardial infarction when compared with infarct size assessed by plasma MB-creatine kinase activity. Thirty patients with enzymatic evidence of infarction were imaged within 12-36 hours of chest pain (mean, 23.4 hours). No patient had a previous infarction, and none underwent intervention seeking to restore coronary patency. Infarct size was quantified with computer-generated polar maps of the myocardial radioactivity and expressed as a percentage of the total left ventricular volume. To assess left and right ventricular performance, blood-pool gated radionuclide angiography was performed immediately after SPECT. All 30 patients had perfusion defects consistent with myocardial infarction. Scintigraphic and enzymatic estimates of infarct size correlated well for the group as a whole (r = 0.78, p less than 0.001, SEE = 9.1) but especially for those patients with anterior infarction (r = 0.91, p less than 0.001, SEE = 7.9). The poor correlation observed in patients with inferior infarction (r = 0.50, p less than 0.05, SEE = 10.0) was believed to be related to the frequent occurrence of right ventricular involvement because SPECT assessed only left ventricular damage, whereas the enzymatic method estimated the myocardial injury in both ventricles. A quantitative index of right ventricular infarct size, derived from the relation between the scintigraphic and enzymatic estimates, had a strong inverse correlation with right ventricular ejection fraction (r = -0.89, p less than 0.001, SEE = 3.6).

  5. Uncommon and dynamic changes detected by 123I-15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid myocardial single photon emission computed tomography in a stunned myocardium induced by coronary microvascular spasm.

    PubMed

    Zen, K; Ito, K; Hikosaka, T; Adachi, Y; Yoneyama, S; Katoh, S; Azuma, A; Sugihara, H; Nakagawa, M

    2000-08-01

    A 55-yr-old man underwent surgery. Soon after the procedure was finished, the patient complained of chest pain, and the electrocardiogram showed increase in the ST-segment in some leads. Emergency angiography showed normal coronary arteries, but there was asynergy in the left ventricle, and delayed filling of contrast medium was observed in the LCA. An intracoronary infusion of isosorbide dinitrate did not improve the delayed filling of contrast medium or ST segment increase in the electrocardiogram. Soon after nicorandil was injected into the LCA, the patient's symptoms, electrocardiogram, and delayed filling of contrast medium dramatically improved. On the second day, initial imaging by 123I-BMIPP myocardial SPECT showed a moderate increase in tracer uptake in the apico-anteroseptal region and a moderate decrease in tracer uptake in the lateral region, in which the first left ventriculography showed akinesis, and delayed imaging revealed a moderate increase in tracer uptake in the apical region and a high washout of 123I-BMIPP in the anteroseptal and lateral regions. On the sixth day, initial imaging by 123I-BMIPP myocardial SPECT showed a moderate decrease in tracer uptake in the apical and lateral regions and a mild decrease in tracer uptake in the anteroseptal region, and delayed imaging revealed a moderate increase in tracer uptake in the apical region and a high washout of 123I-BMIPP in the anteroseptal and lateral regions. By the 30th day, 123I-BMIPP myocardial SPECT had normalized. We consider that these dynamic changes in 123I-BMIPP myocardial SPECT imaging may reflect metabolic changes in fatty acids in the ischemic state, the size of the triacylglycerol pool, and the degree of turnover in the triacylglycerol pool. PMID:11023032

  6. Stress echocardiography: what is new and how does it compare with myocardial perfusion imaging and other modalities?

    PubMed

    Tweet, Marysia S; Arruda-Olson, Adelaide M; Anavekar, Nandan S; Pellikka, Patricia A

    2015-06-01

    Cardiovascular disease is a leading cause of morbidity and mortality, and noninvasive strategies to diagnose and risk stratify patients remain paramount in the evaluative process. Stress echocardiography is a well-established, versatile, real-time imaging modality with advantages including lack of radiation exposure, portability, and affordability. Innovative techniques in stress echocardiography include myocardial contrast echocardiography, deformation imaging, three-dimensional (3D) echocardiography, and assessment of coronary flow reserve. Myocardial perfusion imaging with single-photon emission computed tomography (SPECT) or positron emission tomography (PET) are imaging alternatives, and stress cardiac magnetic resonance imaging and coronary computed tomography (CT) angiography, including CT perfusion imaging, are emerging as newer approaches. This review will discuss recent and upcoming developments in the field of stress testing, with an emphasis on stress echocardiography while highlighting comparisons with other modalities. PMID:25911442

  7. Quantitative High-Efficiency Cadmium-Zinc-Telluride SPECT with Dedicated Parallel-Hole Collimation System in Obese Patients: Results of a Multi-Center Study

    PubMed Central

    Nakazato, Ryo; Slomka, Piotr J.; Fish, Mathews; Schwartz, Ronald G.; Hayes, Sean W.; Thomson, Louise E.J.; Friedman, John D.; Lemley, Mark; Mackin, Maria L.; Peterson, Benjamin; Schwartz, Arielle M.; Doran, Jesse A.; Germano, Guido; Berman, Daniel S.

    2014-01-01

    Background Obesity is a common source of artifact on conventional SPECT myocardial perfusion imaging (MPI). We evaluated image quality and diagnostic performance of high-efficiency (HE) cadmium-zinc-telluride (CZT) parallel-hole SPECT-MPI for coronary artery disease (CAD) in obese patients. Methods and Results 118 consecutive obese patients at 3 centers (BMI 43.6±8.9 kg/m2, range 35–79.7 kg/m2) had upright/supine HE-SPECT and ICA >6 months (n=67) or low-likelihood of CAD (n=51). Stress quantitative total perfusion deficit (TPD) for upright (U-TPD), supine (S-TPD) and combined acquisitions (C-TPD) was assessed. Image quality (IQ; 5=excellent; <3 nondiagnostic) was compared among BMI 35–39.9 (n=58), 40–44.9 (n=24) and ≥45 (n=36) groups. ROC-curve area for CAD detection (≥50% stenosis) for U-TPD, S-TPD, and C-TPD were 0.80, 0.80, and 0.87, respectively. Sensitivity/specificity was 82%/57% for U-TPD, 74%/71% for S-TPD, and 80%/82% for C-TPD. C-TPD had highest specificity (P=.02). C-TPD normalcy rate was higher than U-TPD (88% vs. 75%, P=.02). Mean IQ was similar among BMI 35–39.9, 40–44.9 and ≥45 groups [4.6 vs. 4.4 vs. 4.5, respectively (P=.6)]. No patient had a non-diagnostic stress scan. Conclusions In obese patients, HE-SPECT MPI with dedicated parallel-hole collimation demonstrated high image quality, normalcy rate, and diagnostic accuracy for CAD by quantitative analysis of combined upright/supine acquisitions. PMID:25388380

  8. Wave Propagation of Myocardial Stretch: Correlation with Myocardial Stiffness

    PubMed Central

    Pislaru, Cristina; Pellikka, Patricia A.; Pislaru, Sorin V.

    2015-01-01

    The mechanism of flow propagation during diastole in the left ventricle (LV) has been well described. Little is known about the associated waves propagating along the heart wall s. These waves may have a mechanism similar to pulse wave propagation in arteries. The major goal of the study was to evaluate the effect of myocardial stiffness and preload on this wave transmission. Methods Longitudinal late diastolic deformation and wave speed (Vp) of myocardial stretch in the anterior LV wall were measured using sonomicrometry in sixteen pigs. Animals with normal and altered myocardial stiffness (acute myocardial infarction) were studied with and without preload alterations. Elastic modulus estimated from Vp (EVP; Moens-Korteweg equation) was compared to incremental elastic modulus obtained from exponential end -diastolic stress-strain relation (ESS). Myocardial distensibility and α-and β-coefficients of stress-strain relations were calculated. Results Vp was higher at reperfusion compared to baseline (2.6±1.3 m/s vs. 1.3±0.4 m/s; p=0.005) and best correlated with ESS (r 2=0.80, p<0.0001), β-coefficient (r2=0.78, p<0.0001), distensibility (r2=0.47, p=0.005), and wall thickness/diameter ratio (r2=0.42, p=0.009). Elastic moduli (EVP and ESS) were strongly correlated (r2=0.83, p<0.0001). Increasing preload increased Vp and EVP and decreased distensibility. At multivariate analysis, ESS, wall thickness, and end-diastolic and systolic LV pressures were independent predictors of Vp (r2model=0.83, p<0.0001). Conclusions The main determinants of wave propagation of longitudinal myocardial stretch were myocardial stiffness and LV geometry and pressure. This local wave speed could potentially be measured noninvasively by echocardiography. PMID:25193091

  9. Ready for prime time? Dual tracer PET and SPECT imaging

    PubMed Central

    Fakhri, Georges El

    2012-01-01

    Dual isotope single photon emission computed tomography (SPECT) and dual tracer positron emission tomography (PET) imaging have great potential in clinical and molecular applications in the pediatric as well as the adult populations in many areas of brain, cardiac, and oncologic imaging as it allows the exploration of different physiological and molecular functions (e.g., perfusion, neurotransmission, metabolism, apoptosis, angiogenesis) under the same physiological and physical conditions. This is crucial when the physiological functions studied depend on each other (e.g., perfusion and metabolism) hence requiring simultaneous assessment under identical conditions, and can reduce greatly the quantitation errors associated with physical factors that can change between acquisitions (e.g., human subject or animal motion, change in the attenuation map as a function of time) as is detailed in this editorial. The clinical potential of simultaneous dual isotope SPECT, dual tracer PET and dual SPECT/PET imaging are explored and summarized. In this issue of AJNMMI (http://www.ajnmmi.us), Chapman et al. explore the feasibility of simultaneous and sequential SPECT/PET imaging and conclude that down-scatter and crosstalk from 511 keV photons preclude obtaining useful SPECT information in the presence of PET radiotracers. They report on an alternative strategy that consists of performing sequential SPECT and PET studies in hybrid microPET/SPECT/CT scanners, now widely available for molecular imaging. They validate their approach in a phantom consisting of a 96-well plate with variable 99mTc and 18F concentrations and illustrate the utility of such approaches in two sequential SPECT-PET/CT studies that include 99mTc-MAA/18F-NaF and 99mTc-Pentetate/18F-NaF. These approaches will need to be proven reproducible, accurate and robust to variations in the experimental conditions before they can be accepted by the molecular imaging community and be implemented in routine molecular

  10. Radiation-induced myocardial perfusion abnormalities in breast cancer patients following external beam radiation therapy

    PubMed Central

    Eftekhari, Mohammad; Anbiaei, Robabeh; Zamani, Hanie; Fallahi, Babak; Beiki, Davood; Ameri, Ahmad; Emami-Ardekani, Alireza; Fard-Esfahani, Armaghan; Gholamrezanezhad, Ali; Seid Ratki, Kazem Razavi; Roknabadi, Alireza Momen

    2015-01-01

    Objective(s): Radiation therapy for breast cancer can induce myocardial capillary injury and increase cardiovascular morbidity and mortality. A prospective cohort was conducted to study the prevalence of myocardial perfusion abnormalities following radiation therapy of left-sided breast cancer patients as compared to those with right–sided cancer. Methods: To minimize potential confounding factors, only those patients with low 10-year risk of coronary artery disease (based on Framingham risk scoring) were included. All patients were initially treated by modified radical mastectomy and then were managed by postoperative 3D Conformal Radiation Therapy (CRT) to the surgical bed with an additional 1-cm margin, delivered by 46-50 Gy (in 2 Gy daily fractions) over a 5-week course. The same dose-adjusted chemotherapy regimen (including anthracyclines, cyclophosphamide and taxol) was given to all patients. Six months after radiation therapy, all patients underwent cardiac SPECT for the evaluation of myocardial perfusion. Results: A total of 71 patients with a mean age of 45.3±7.2 years [35 patients with leftsided breast cancer (exposed) and 36 patients with right-sided cancer (controls)] were enrolled. Dose-volume histogram (DVH) [showing the percentage of the heart exposed to >50% of radiation] was significantly higher in patients with left-sided breast cancer. Visual interpretation detected perfusion abnormalities in 42.9% of cases and 16.7% of controls (P=0.02, Odds ratio=1.46). In semiquantitative segmental analysis, only apical (28.6% versus 8.3%, P=0.03) and anterolateral (17.1% versus 2.8%, P=0.049) walls showed significantly reduced myocardial perfusion in the exposed group. Summed Stress Score (SSS) of>3 was observed in twelve cases (34.3%), while in five of the controls (13.9%),(Odds ratio=1.3). There was no significant difference between the groups regarding left ventricular ejection fraction. Conclusion: The risk of radiation induced myocardial perfusion

  11. Comparison of transmission acquisition approaches for SPECT nonuniform attenuation compensation

    SciTech Connect

    Gilland, D.R.; Jaszczak, R.J.; Turkington, T.G.; Coleman, R.E.

    1998-06-01

    This study compared two approaches for acquiring transmission computed tomography (TCT) data for SPECT nonuniform attenuation compensation. One approach, which has been implemented in commercial SPECT systems, acquires the TCT and SPECT data simultaneously using a scanning transmission line source, dual head SPECT system and parallel beam collimation (PB-sim). The other approach acquires the TCT and SPECT data sequentially using long focus, off-set fan beam collimation with a non-scanning line source and a triple head system (FB-seq). The two systems were compared based on: (a) the noise level of the TCT projection data, (b) the spatial resolution of the TCT projection data, and (c) the quality of reconstructed TCT and SPECT images of a thorax phantom. For the thorax phantom data a fast TCT scan (2 min.) was used and total scan time (TCT and SPECT) was the same for the two systems. The results from the TCT noise measurements showed that for the source activities used here (400 mCi for PB-sim, 56 mCi for FB-seq), PB-sim had higher in the heart and liver regions. The measured TCT spatial resolution for the two systems was comparable in the axial direction but was superior with FB-seq in the transaxial direction. The resolution difference was apparent in the reconstructed TCT images. These results suggest that the FB-seq system offers a viable approach for TCT acquisition and one that compares favorably with current commercial approaches based on TCT noise, resolution and reconstructed image quality.

  12. Diagnosis of orbital cavernous hemangioma with Tc-99m RBC SPECT.

    PubMed

    Ki, W W; Shin, J W; Won, K S; Ryu, J S; Yang, S O; Lee, H K; Kim, Y J

    1997-08-01

    The authors report two cases of orbital cavernous hemangioma diagnosed by Tc-99m RBC SPECT. Tc-99m RBC SPECT showed a typical scintigraphic pattern commonly seen in hepatic hemangioma in which there is intense focally increased uptake on delayed SPECT images. Tc-99m RBC SPECT in orbital cavernous hemangioma may be as useful a diagnostic modality as in hepatic hemangioma. PMID:9262901

  13. CAD of myocardial perfusion

    NASA Astrophysics Data System (ADS)

    Storm, Corstiaan J.; Slump, Cornelis H.

    2007-03-01

    Our purpose is in the automated evaluation of the physiological relevance of lesions in coronary angiograms. We aim to extract as much as possible quantitative information about the physiological condition of the heart from standard angiographic image sequences. Coronary angiography is still the gold standard for evaluating and diagnosing coronary abnormalities as it is able to locate precisely the coronary artery lesions. The dimensions of the stenosis can be assessed nowadays successfully with image processing based Quantitative Coronary Angiography (QCA) techniques. Our purpose is to assess the clinical relevance of the pertinent stenosis. We therefore analyze the myocardial perfusion as revealed in standard angiographic image sequences. In a Region-of-Interest (ROI) on the angiogram (without an overlaying major blood vessel) the contrast is measured as a function of time (the so-called time-density curve). The required hyperemic state of exercise is induced artificially by the injection of a vasodilator drug e.g. papaverine. In order to minimize motion artifacts we select based on the recorded ECG signal end-diastolic images in both a basal and a hyperemic run in the same projection to position the ROI. We present the development of the algorithms together with results of a small study of 20 patients which have been catheterized following the standard protocol.

  14. Experimental myocardial infarction

    PubMed Central

    Hood, William B.; Bianco, Jesus A.; Kumar, Raj; Whiting, Richard B.

    1970-01-01

    Compliance of the infarcted left ventricle was studied in dogs 3-5 days after occlusion of the left anterior descending coronary artery. Compliance was assessed from postmortem pressure-volume curves and from pressure-length measurements (mercury-in-silastic segment length gauges) made both in vivo and postmortem. Postmortem pressure-volume curves showed reduced compliance compared to sham-operated animals. Postmortem pressure-length curves of infarcted and adjacent normal myocardium indicated that the diminished total compliance could be attributed to an increase in stiffness of the infarcted area. This was confirmed by in vivo end-diastolic pressure-length changes produced by transient aortic occlusion. The infarcted area was akinetic, showing neither contraction nor aneurysmal bulging. In addition, anesthetized dogs with infarcts, when compared with sham-operated animals, had similar left ventricular end-diastolic volumes (indicator dilution method), but higher left ventricular end-diastolic pressures. Taken with previous observations, which show that systolic aneurysmal bulging is uniformly present at the onset of ischemia, these results indicate that stiffening of the ischemic myocardium occurs during the first 5 days after infarction, and show that elevation of left ventricular filling pressure does not necessarily signify ventricular dilatation. The results also suggest a mechanism whereby ventricular performance may improve during recovery from acute myocardial infarction. Images PMID:4914678

  15. Myocardial perfusion imaging for detection of silent myocardial ischemia

    SciTech Connect

    Beller, G.A.

    1988-04-21

    Despite the widespread use of the exercise stress test in diagnosing asymptomatic myocardial ischemia, exercise radionuclide imaging remains useful for detecting silent ischemia in numerous patient populations, including those who are totally asymptomatic, those who have chronic stable angina, those who have recovered from an episode of unstable angina or an uncomplicated myocardial infarction, and those who have undergone angioplasty or received thrombolytic therapy. Studies show that thallium scintigraphy is more sensitive than exercise electrocardiography in detecting ischemia, i.e., in part, because perfusion defects occur more frequently than ST depression and before angina in the ischemic cascade. Thallium-201 scintigraphy can be performed to differentiate a true- from a false-positive exercise electrocardiographic test in patients with exercise-induced ST depression and no angina. The development of technetium-labeled isonitriles may improve the accuracy of myocardial perfusion imaging. 11 references.

  16. MYOCARDIAL AKT: THE OMNIPRESENT NEXUS

    PubMed Central

    Sussman, Mark A.; Völkers, Mirko; Fischer, Kimberlee; Bailey, Brandi; Cottage, Christopher T.; Din, Shabana; Gude, Natalie; Avitabile, Daniele; Alvarez, Roberto; Sundararaman, Balaji; Quijada, Pearl; Mason, Matt; Konstandin, Mathias H.; Malhowski, Amy; Cheng, Zhaokang; Khan, Mohsin; McGregor, Michael

    2013-01-01

    One of the greatest examples of integrated signal transduction is revealed by examination of effects mediated by AKT kinase in myocardial biology. Positioned at the intersection of multiple afferent and efferent signals, AKT exemplifies a molecular sensing node that coordinates dynamic responses of the cell in literally every aspect of biological responses. The balanced and nuanced nature of homeostatic signaling is particularly essential within the myocardial context, where regulation of survival, energy production, contractility, and response to pathological stress all flow through the nexus of AKT activation or repression. Equally important, the loss of regulated AKT activity is primarily the cause or consequence of pathological conditions leading to remodeling of the heart and eventual decompensation. This review presents an overview compendium of the complex world of myocardial AKT biology gleaned from more than a decade of research. Summarization of the widespread influence that AKT exerts upon myocardial responses leaves no doubt that the participation of AKT in molecular signaling will need to be reckoned with as a seemingly omnipresent regulator of myocardial molecular biological responses. PMID:21742795

  17. How reliable is myocardial imaging in the diagnosis of acute myocardial infarction

    SciTech Connect

    Willerson, J.T.

    1983-01-01

    Myocardial scintigraphic techniques available presently allow a sensitive and relatively specific diagnosis of acute myocardial infarction when they are used correctly, although every technique has definite limitations. Small myocardial infarcts (less than 3 gm.) may be missed, and there are temporal limitations in the usefulness of the scintigraphic techniques. The development of tomographic methodology that may be used with single-photon radionuclide emitters (including technetium and /sup 201/Tl will allow the detection of relatively small abnormalities in myocardial perfusion and regions of myocardial infarction and will help to provide a more objective interpretation of the myocardial scintigrams. The use of overlay techniques allowing simultaneous assessment of myocardial perfusion, infarct-avid imaging, and radionuclide ventriculograms will provide insight into the relevant aspects of the extent of myocardial damage, the relationship of damage to myocardial perfusion, and the functional impact of myocardial infarction on ventricular performance.

  18. Multimodality tomographic scintimammography with PET, PECI, and SPECT: initial evaluation

    NASA Astrophysics Data System (ADS)

    Krol, Andrzej; Feiglin, David H.; Thomas, Frank D.; Hellwig, Bradford J.; Gagne, George M.

    2002-04-01

    We compared tomographic scintimammography performed using single photon emission computed tomography (SPECT), positron emission coincidence imaging (PECI) and positron emission tomography (PET). A female thorax phantom was used. Activities of the myocardium, thorax and breasts were adjusted to emulate the count rate observed with patients. Hollow plastic spheres, imitating hot lesions (1.5-20ml), filled with radioactive saline were inserted in the center of each breast. Specific activities of internal organs were adjusted to emulate the count rate observed with patients. SPECT data were acquired with Tc-99m using gamma cameras with NaI(Tl) detectors. A modified FBP (CODE) reconstruction algorithm was used to render SPECT tomographic images. PECI (Siemens E.CAM with NaI(Tl)) and PET (GE Advance with BGO) data were acquired using F-18 FDG. Vendor supplied reconstruction algorithms were used. The reconstructed hot lesions contrast and resolution were investigated. Image quality obtained can be ranked as follows: (1) PET(BGO), (2) PECI(NaI), (3) SPECT(NaI) In conclusion, assuming comparable uptake values of Tc-99m-sestamibi and F-18 FDG, PET seems to be a superior methodology in visualization of breast lesion as compared to SPECT and PECI. All these tomographic methods appear to be promising adjunct to x-ray mammography in difficult to interpret cases.

  19. Performance Evaluation of a Bedside Cardiac SPECT System

    SciTech Connect

    M.T. Studenski, D.R. Gilland, J.G. Parker, B. Hammond, S. Majewski, A.G. Weisenberger, V. Popov

    2009-06-01

    This paper reports on the initial performance evaluation of a bedside cardiac PET/SPECT system. The system was designed to move within a hospital to image critically-ill patients, for example, those in intensive care unit (ICU) or emergency room settings, who cannot easily be transported to a conventional SPECT or PET facility. The system uses two compact (25 cm times 25 cm) detectors with pixilated NaI crystals and position sensitive PMTs. The performance is evaluated for both 140 keV (Tc-99m) and 511 keV (F-18) emitters with the system operating in single photon counting (SPECT) mode. The imaging performance metrics for both 140 keV and 511 keV included intrinsic energy resolution, spatial resolution (intrinsic, system, and reconstructed SPECT), detection sensitivity, count rate capability, and uniformity. Results demonstrated an intrinsic energy resolution of 31% at 140 keV and 23% at 511 keV, a planar intrinsic spatial resolution of 5.6 mm full width half-maximum (FWHM) at 140 keV and 6.3 mm FWHM at 511 keV, and a sensitivity of 4.15 countsmiddotmuCi-1 ldr s-1 at 140 keV and 0.67 counts ldr muCi-1 ldr s-1 at 511 keV. To further the study, a SPECT acquisition using a dynamic cardiac phantom was performed, and the resulting reconstructed images are presented.

  20. Parallel-hole collimator concept for stationary SPECT imaging

    NASA Astrophysics Data System (ADS)

    Pato, Lara R. V.; Vandenberghe, Stefaan; Zedda, Tiziana; Van Holen, Roel

    2015-11-01

    Parallel-hole SPECT collimators have traditionally been manufactured by stacking sheets of lead foil or by casting. These techniques significantly restrict our options in terms of collimator geometry. However, recent developments in metal additive manufacturing are making novel collimator designs possible, giving rise to new opportunities in SPECT imaging. In this paper we propose an innovative type of collimator for stationary SPECT, using parallel-holes whose collimation direction depends on their axial position. Its main advantage compared to current stationary SPECT systems (which are based on pinholes) is that, using only axial bed translations, we can achieve complete angular sampling of an increased portion of the transaxial area of the collimator bore. This allows the system to be much more compact than current stationary SPECT systems that image objects of the same size. We describe three possible designs, for full-body, brain and small-animal imaging, respectively, and test their feasibility using simulations. The system modeling method is validated against realistic Monte Carlo simulations, and then used in the evaluation of the systems’ performances and reconstructions. The simulations show that the system is able to reconstruct objects occupying the predicted field of view (75% of the transaxial area of the bore) without sampling artifacts. In particular, we perform reconstructions from noisy projection data obtained for an activity and scanning time similar to standard protocols for the three applications, and the resulting images indicate the possibility of using the proposed systems in practice.

  1. Parallel-hole collimator concept for stationary SPECT imaging.

    PubMed

    Pato, Lara R V; Vandenberghe, Stefaan; Zedda, Tiziana; Van Holen, Roel

    2015-11-21

    Parallel-hole SPECT collimators have traditionally been manufactured by stacking sheets of lead foil or by casting. These techniques significantly restrict our options in terms of collimator geometry. However, recent developments in metal additive manufacturing are making novel collimator designs possible, giving rise to new opportunities in SPECT imaging. In this paper we propose an innovative type of collimator for stationary SPECT, using parallel-holes whose collimation direction depends on their axial position. Its main advantage compared to current stationary SPECT systems (which are based on pinholes) is that, using only axial bed translations, we can achieve complete angular sampling of an increased portion of the transaxial area of the collimator bore. This allows the system to be much more compact than current stationary SPECT systems that image objects of the same size. We describe three possible designs, for full-body, brain and small-animal imaging, respectively, and test their feasibility using simulations. The system modeling method is validated against realistic Monte Carlo simulations, and then used in the evaluation of the systems' performances and reconstructions. The simulations show that the system is able to reconstruct objects occupying the predicted field of view ([Formula: see text] of the transaxial area of the bore) without sampling artifacts. In particular, we perform reconstructions from noisy projection data obtained for an activity and scanning time similar to standard protocols for the three applications, and the resulting images indicate the possibility of using the proposed systems in practice. PMID:26528908

  2. A 3D image analysis tool for SPECT imaging

    NASA Astrophysics Data System (ADS)

    Kontos, Despina; Wang, Qiang; Megalooikonomou, Vasileios; Maurer, Alan H.; Knight, Linda C.; Kantor, Steve; Fisher, Robert S.; Simonian, Hrair P.; Parkman, Henry P.

    2005-04-01

    We have developed semi-automated and fully-automated tools for the analysis of 3D single-photon emission computed tomography (SPECT) images. The focus is on the efficient boundary delineation of complex 3D structures that enables accurate measurement of their structural and physiologic properties. We employ intensity based thresholding algorithms for interactive and semi-automated analysis. We also explore fuzzy-connectedness concepts for fully automating the segmentation process. We apply the proposed tools to SPECT image data capturing variation of gastric accommodation and emptying. These image analysis tools were developed within the framework of a noninvasive scintigraphic test to measure simultaneously both gastric emptying and gastric volume after ingestion of a solid or a liquid meal. The clinical focus of the particular analysis was to probe associations between gastric accommodation/emptying and functional dyspepsia. Employing the proposed tools, we outline effectively the complex three dimensional gastric boundaries shown in the 3D SPECT images. We also perform accurate volume calculations in order to quantitatively assess the gastric mass variation. This analysis was performed both with the semi-automated and fully-automated tools. The results were validated against manual segmentation performed by a human expert. We believe that the development of an automated segmentation tool for SPECT imaging of the gastric volume variability will allow for other new applications of SPECT imaging where there is a need to evaluate complex organ function or tumor masses.

  3. The role of gated myocardial perfusion scintigraphy (GMPS) in myocarditis: a case report and review of the literature.

    PubMed

    Javadi, Hamid; Jallalat, Sara; Pourbehi, Gholamreza; Semnani, Shahriar; Mogharrabi, Mehdi; Nabipour, Iraj; Ravanbod, Mohammadreza; Amini, Abdullatif; Assadi, Majid

    2011-01-01

    Acute myocarditis is one of the most challenging diagnoses and treatments in cardiology. The acute viral myocarditis diagnosis is usually based on high suspicion, history taking, and physical examination. Likewise, the use of chest radiography, electrocardiography (ECG), and echocardiography is helpful in making a final diagnosis, but all are non-specific. In addition, in imaging query, magnetic resonance imaging (MRI) depicts some degree of cardiac inflammation in the course of myocarditis. Myocardial perfusion imaging (MPI) has also been shown to be useful in diagnosis, and this noninvasive technique diminishes the need for myocardial biopsy. The current study presents the diagnostic and prognostic role of MPI in a 25-year-old patientwith suspected myocarditis. The patient underwent gated-technetium- 99m-lablled, methoxyisobutyl isonitrile, single photon emission computed tomography (Gated 99mTc-MIBI SPECT) that showed nonheterogeneous absorption with remarkable decreased radiotracer uptake in the myocardium in both stress and rest phases. In addition, the gated mode demonstrated decreased wall motion and thickening of the myocardium with a sum motion score (SMS) of 28, a sum thickening score (STS) of 15, and a measured LVEF of 34%. The study concludes that 99mTC-MIBI SPECT imaging is a useful modality in the preparation of supplementary diagnostic and prognostic information in viral myocarditis. PMID:22219153

  4. Effect of intramyocardial bone marrow-derived mononuclear cell injection on cardiac sympathetic innervation in patients with chronic myocardial ischemia.

    PubMed

    van Ramshorst, Jan; Beeres, Saskia L M A; Rodrigo, Sander F; Dibbets-Schneider, Petra; Scholte, Arthur J; Fibbe, Willem E; Zwaginga, Jaap J; Schalij, Martin J; Bax, Jeroen J; Atsma, Douwe E

    2014-03-01

    Intramyocardial bone marrow cell injection has been associated with improvements in myocardial perfusion and left ventricular function. The current substudy of a randomized, placebo-controlled, double-blinded study, investigated the effect of intramyocardial bone marrow cell injection on myocardial sympathetic innervation in patients with chronic myocardial ischemia. In a total of 16 patients (64 ± 8 years, 13 men), early and late iodine-123 metaiodobenzylguanidine (MIBG) imaging was performed before and 3 months after intramyocardial bone marrow cell injection. No improvements were observed in global early H/M ratio (P = 0.40), late H/M ratio (P = 0.43) and cardiac washout rate (P = 0.98). However, late 123-I MIBG SPECT defect score showed a trend to improvement in the bone marrow cell group (from 31.0 ± 7.1 to 28.1 ± 14.9) as compared to the placebo group (from 33.6 ± 8.5 to 34.5 ± 9.8, P = 0.055 between groups). This trend was mainly driven by a substantial improvement in three bone marrow cell-treated patients, which all had diabetes and severe MIBG defects. In these patients, the extent and severity of MIBG defects improved substantially independent of myocardial perfusion and cell injection sites. The present study does not demonstrate improvements in global cardiac sympathetic nerve innervation after intramyocardial bone marrow cell injection in patients with chronic myocardial ischemia. However, regional analysis of sympathetic nerve innervation reveals improvements in three diabetic patients independent of myocardial perfusion, suggestive of a therapeutic effect on diabetic cardiac sympathetic dysinnervation. PMID:24481723

  5. A SPECT imager with synthetic collimation

    PubMed Central

    Havelin, Ronan J.; Miller, Brian W.; Barrett, Harrison H.; Furenlid, Lars R.; Murphy, J M; Foley, Mark J.

    2015-01-01

    This work outlines the development of a multi-pinhole SPECT system designed to produce a synthetic-collimator image of a small field of view. The focused multi-pinhole collimator was constructed using rapid-prototyping and casting techniques. The collimator projects the field of view through forty-six pinholes when the detector is adjacent to the collimator. The detector is then moved further from the collimator to increase the magnification of the system. The amount of pinhole-projection overlap increases with the system magnification. There is no rotation in the system; a single tomographic angle is used in each system configuration. The maximum-likelihood expectation-maximization (MLEM) algorithm is implemented on graphics processing units to reconstruct the object in the field of view. Iterative reconstruction algorithms, such as MLEM, require an accurate model of the system response. For each system magnification, a sparsely-sampled system response is measured by translating a point source through a grid encompassing the field of view. The pinhole projections are individually identified and associated with their respective apertures. A 2D elliptical Gaussian model is applied to the pinhole projections on the detector. These coefficients are associated with the object-space location of the point source, and a finely-sampled system matrix is interpolated. Simulations with a hot-rod phantom demonstrate the efficacy of combining low-resolution non-multiplexed data with high-resolution multiplexed data to produce high-resolution reconstructions. PMID:26346410

  6. Positron Emission Tomography for the Assessment of Myocardial Viability

    PubMed Central

    2005-01-01

    ventricular (LV) viability is, therefore, critical in deciding whether a patient with coronary artery disease and severe LV dysfunction should undergo revascularization, receive a heart transplant, or remain on medical therapy. Assessment of Left Ventricular Viability Techniques for assessing myocardial viability depend on the measurement of a specific characteristic of viable myocytes such as cell membrane integrity, preserved metabolism, mitochondria integrity, and preserved contractile reserve. In Ontario, single photon emission computed tomography (SPECT) using radioactive 201thallium is the most commonly used technique followed by dobutamine echocardiography. Newer techniques include SPECT using technetium tracers, cardiac magnetic resonance imaging, and PET, the subject of this review. Positron Emission Tomography PET is a nuclear imaging technique based on the metabolism of radioactive analogs of normal substrates such as glucose and water. The radiopharmaceutical used most frequently in myocardial viability assessment is F18 fluorodeoxyglucose (FDG), a glucose analog. The procedure involves the intravenous administration of FDG under controlled glycemic conditions, and imaging with a PET scanner. The images are reconstructed using computer software and analyzed visually or semi-quantitatively, often in conjunction with perfusion images. Dysfunctional but stunned myocardium is characterized by normal perfusion and normal FDG uptake; hibernating myocardium exhibits reduced perfusion and normal/enhanced FDG uptake (perfusion/metabolism mismatch), whereas scar tissue is characterized by reduction in both perfusion and FDG uptake (perfusion/metabolism match). Review Strategy The Medical Advisory Secretariat used a search strategy similar to that used in the 2001 ICES review to identify English language reports of health technology assessments and primary studies in selected databases, published from January 1, 2001 to April 20, 2005. Patients of interest were those with

  7. Myocardial infarction following bee sting.

    PubMed

    Puvanalingam, A; Karpagam, P; Sundar, C; Venkatesan, S; Ragunanthanan

    2014-08-01

    Bee stings are commonly encountered worldwide. Various manifestations after bee sting have been described. Local reactions are common. Unusually, manifestations like vomiting, diarrhoea, dyspnoea, generalised oedema, acute renal failure, hypotension and collapse may occur. Rarely vasculitis, serum sickness, neuritis and encephalitis have been described which generally develop days to weeks after a sting. Acute coronary syndromes after hymenoptera stings and other environmental exposures are referred to as the Kounis syndrome or allergic myocardial ischaemia and infarction. We report a 60 year old male who developed myocardial infarction after multiple bee stings over his body. PMID:25856951

  8. Receptor Specific Ligands for Spect Imaging

    SciTech Connect

    Kung, H. F.

    2003-02-25

    In the past funding period we have concentrated in developing new 99mTc labeled MIBG analogs. Basic chemistry of ligand synthesis, radiochemistry of Re and 99mTc complex formation, separation of stereoisomers and in vitro stability were investigated. We have prepared a number of new MIBG derivatives containing chelating moiety N2S2 and additional groups to increase lipophilicity. Unfortunately none of the new 99mTc labeled MIBG analogs showed promise as an imaging agent for myocardial neuronal function. Radioactive-iodine-labeled meta-iodobenzylguanidine (MIBG) is currently being used as an in vivo imaging agent to evaluate neuroendocrine tumors as well as the myocardial sympathetic nervous system in patients with myocardial infarct and cardiomyopathy. It is generally accepted that MIBG is an analog of norepinephrine and its uptake in the heart corresponds to the distribution of norepinephrine and the density of sympathetic neurons. A series of MIBG derivatives containing suitable chelating functional groups N2S2 for the formation of [Tcv0]+3N2S2 complex was successfully synthesized and the 99mTc-labeled complexes were prepared and tested in rats. One of the compounds, [99mTc]M2, tested showed significant, albeit lower, heart uptakes post iv injection in rats (0.18% dose/organ at 4 hours) as compared to [l25l]MIBG (1.4% dose/organ at 4 hours). The heart uptake of the 99mTc-labeled complex, [99mTc]M2, appears to be specific and can be reduced by coinjection with nonradioactive MIBG or by pretreatment with desipramine. a selective norepinephrine transporter inhibitor. Further evaluation of the in vitro uptake of [99mTc]M2 in cultured neuroblastoma cells displayed consistently lower, but measurable uptake (app. 10% of that for [125l]MlBG). These preliminary results suggested that the mechanisms of heart uptake of [99mTc]M2 may be related to those for [125l]MIBG uptake. To improve the heart uptake of the MIBG derivatives we have developed chemistry related to the

  9. Modeling dynamic PET-SPECT studies in the wavelet domain.

    PubMed

    Turkheimer, F E; Banati, R B; Visvikis, D; Aston, J A; Gunn, R N; Cunningham, V J

    2000-05-01

    This work develops a theoretical framework and corresponding algorithms for the modeling of dynamic PET-SPECT studies both in time and space. The problem of estimating the spatial dimension is solved by applying the wavelet transform to each scan of the dynamic sequence and then performing the kinetic modeling and statistical analysis in the wavelet domain. On reconstruction through the inverse wavelet transform, one obtains parametric images that are consistent estimates of the spatial patterns of the kinetic parameter of interest. The theoretical setup allows the use of linear techniques currently used in PET-SPECT for kinetic analysis. The method is applied to artificial and real data sets. The application to dynamic PET-SPECT studies was performed both for validation purposes, when the spatial patterns are known, and for illustration of the advantages offered by the technique in case of tracers with an unknown pattern of distribution. PMID:10826539

  10. Brain SPECT thallium using cadmium zinc telluride: a first experience.

    PubMed

    Farid, Karim; Queneau, Mathieu; Guernou, Mohamed; Lussato, David; Petras, Slavomir; Songy, Bernard

    2011-11-01

    A 70-year-old man underwent a thallium-201 brain SPECT in the work-up and characterization of a frontotemporal mass. SPECT images were performed on cadmium zinc telluride system during only 5 minutes and after the injection of only 2 mCi. Images demonstrated high thallium uptake in frontotemporal areas considered as a potential malignant tumor. Surgical removal confirmed the diagnosis of malignant glioblastoma. The thallium SPECT fast acquisition imaging on cadmium zinc telluride systems is feasible with reduced injected dose. This method allows a significantly decrease of patient radiation exposure without compromising the image quality. This initial experience needs to be confirmed and optimized in larger clinical studies. PMID:21975418

  11. The role of DAT-SPECT in movement disorders.

    PubMed

    Kägi, G; Bhatia, K P; Tolosa, E

    2010-01-01

    Dopamine transporter (DAT) imaging is a sensitive method to detect presynaptic dopamine neuronal dysfunction, which is a hallmark of neurodegenerative parkinsonism. DAT imaging can therefore assist the differentiation between conditions with and without presynaptic dopaminergic deficit. Diagnosis of Parkinson disease or tremor disorders can be achieved with high degrees of accuracy in cases with full expression of classical clinical features; however, diagnosis can be difficult, since there is a substantial clinical overlap especially in monosymptomatic tremor (dystonic tremor, essential tremor, Parkinson tremor). The use of DAT-SPECT can prove or excludes with high sensitivity nigrostriatal dysfunction in those cases and facilitates early and accurate diagnosis. Furthermore, a normal DAT-SPECT is helpful in supporting a diagnosis of drug-induced-, psychogenic- and vascular parkinsonism by excluding underlying true nigrostriatal dysfunction. This review addresses the value of DAT-SPECT and its impact on diagnostic accuracy in movement disorders presenting with tremor and/or parkinsonism. PMID:20019219

  12. Evaluation of simultaneous 201Tl/99mTc dual-isotope cardiac SPECT imaging with model-based crosstalk compensation using canine studies

    PubMed Central

    Du, Y.; Links, J. M.; Becker, L.; DiPaula, A. F.; Frank, T.; Schuleri, K. H.; Lardo, A. C.; Frey, E. C.

    2014-01-01

    Background Simultaneous 201Tl/99mTc-Sestamibi dual-isotope myocardial perfusion SPECT imaging can reduce imaging time and produce perfectly registered rest/stress images. However, crosstalk from 99mTc into 201Tl images can significantly reduce 201Tl image quality. We have developed a model-based compensation (MBC) method to compensate for this crosstalk. The method has previously been validated with phantom and simulation studies. In this study, we evaluated the MBC method using a canine model. Methods Left anterior descending or left circumflex coronary artery stenoses were created in 50 adult mongrel dogs weighing 20–30 kg. The dogs were injected with 111 MBq (3 mCi) of 201Tl at rest, and a SPECT study acquired. Stress was induced by administering adenosine to the dog, followed by injection of 740 MBq (20 mCi) of 99mTc-Sestamibi at peak stress. A second SPECT study was performed with data acquired in both 201Tl and 99mTc energy windows to provide simultaneous dual-isotope projection data. The images were reconstructed using the ordered subsets-expectation maximization (OS-EM) reconstruction algorithm with compensation for attenuation, scatter and detector response. For simultaneously acquired 201Tl data, we also applied the MBC method to compensate for crosstalk contamination from 99mTc. Results Without compensation, 99mTc crosstalk increased the estimated 201Tl activity concentration in the rest images and reduced defect contrast. After MBC, the 201Tl images were in good agreement with the registered single isotope images and ex vivo count data. The ischemic (IS) to non-ischemic (NIS) region 201Tl activity concentration ratios were computed for single isotope and dual isotope studies. The correlation with ex vivo IS-NIS ratios was 0.815 after MBC, compared to the 0.495 from data without compensation. In addition, the regression line for the IS-NIS ratios with MBC was almost parallel to the line of identity with a slope of 0.93, compared to a slope of 0

  13. [Acute myocardial infarction: comparison of results of Tl-201, Tc-99m pyrophosphate and In-111 antimyosin Fab imagings].

    PubMed

    Naruse, H; Morita, M; Yamamoto, J; Kawamoto, H; Itano, M; Fukutake, N; Ohyanagi, M; Fujitani, K; Iwasaki, T; Fukuchi, M

    1992-01-01

    To evaluate the extent and characteristics of infarct areas, we performed indium-111 monoclonal antimyosin Fab (InAM), thallium-201 (TL) and Tc-99m pyrophosphate (PYP) imagings in 17 patients with acute myocardial infarction, and tried to find out the mechanism that causes difference of these imagings. In each study, the extent scores as an index of the infarct area were obtained by single photon emission computed tomography (SPECT), and comparisons were made between the results obtained. The overlap between InAM and TL imagings obtained by SPECT was evaluated. Location, severity, extent and patterns of accumulation were compared between InAM and PYP with both planar image and SPECT. The extent scores of InAM correlated well with those of TL (r = 0.73, p < 0.01). However, the overlap of both methods was recognized in 8 of 17 patients, in whom wall thickness of the infarct area as obtained by echocardiography was well preserved. The left ventricular regional asynergy was mild in 6 of these 8 patients. Coronary angiography showed poor or no collateral circulation in these cases. Although there were generally close correlations of the extent scores between InAM and PYP, discrepancy was noted in 2 cases for location; 2 for severity, 5 for extent, and 3 for patterns of accumulation. These differences may be attributed to the timings of imaging, coronary reperfusion and different mechanisms of accumulation. In conclusion, the extent of acute myocardial infarction obtained by InAM correlates well with those obtained by TL and PYP, with some exceptions. PMID:1339788

  14. Biodistribution and radiodosimetry of a novel myocardial perfusion tracer 123I-CMICE-013 in healthy rats

    PubMed Central

    2014-01-01

    Background 123I-CMICE-013 is a novel radiotracer previously reported to have promising characteristics for single-photon emission computed tomography (SPECT) myocardial perfusion imaging. We evaluated the biokinetics and radiodosimetry of this rotenone-like 123I-labeled tracer in a microSPECT imaging-based study. Methods 37 to 111 MBq of 123I-CMICE-013 was synthesized and administered intravenously to 14 healthy rats. Images were acquired with a microSPECT/CT camera at various time intervals and reconstructed to allow activity quantification in the tissues of interest. Radiation dosage resulted from the injection of 123I-CMICE-013 was estimated base on the biodistribution data. Tissue uptake values from image analysis were verified by gamma-counting dissected organs ex vivo. Results The heart/stomach and heart/intestine uptake ratios peaked shortly after the injection of 123I-CMICE-013, meanwhile the heart/liver ratio reached 2 as early as at 23 min post-injection. Little activity was observed in the lung and overnight clearance was significant in most of the measured tissues. The radiation dosimetry analysis based on the time-activity curves provided an estimate of the effective human dose of 6.99E-03 mSv/MBq using ICRP 60 and 7.15E-03 mSv/MBq using ICRP 103, which is comparable to the popular myocardium perfusion imaging (MPI) agents such as 99mTc-tetrofosmin and 99mTc-sestamibi, as well as other 123I-based radiotracers. Conclusions 123I-CMICE-013 demonstrated desirable characteristics in its biokinetic and radiodosimetric profiles, supporting its potential application as a novel myocardial perfusion imaging agent. PMID:24620906

  15. Thallium-201 myocardial scintigraphy in acute myocardial infarction and ischemia

    SciTech Connect

    Wackers, F.J.

    1982-04-01

    Thallium-201 scintigraphy provides a sensitive and reliable method of detecting acute myocardial infarction and ischemia when imaging is performed with understanding of the temporal characteristics and accuracy of the technique. The results of scintigraphy are related to the time interval between onset of symptoms and time of imaging. During the first 6 hr after chest pain almost all patients with acute myocardial infarction and approximately 50% of the patients with unstable angina will demonstrate /sup 201/TI pefusion defects. Delayed imaging at 2-4 hr will permit distinction between ischemia and infarction. In patients with acute myocardial infarction, the size of the perfusion defect accurately reflects the extent of the infarcted and/or jeopardized myocardium, which may be used for prognostic stratification. In view of the characteristics of /sup 201/TI scintigraphy, the most practical application of this technique is in patients in whom myocardial infarction has to be ruled out, and for early recognition of patients at high risk for complications.

  16. Real-time SPECT and 2D ultrasound image registration.

    PubMed

    Bucki, Marek; Chassat, Fabrice; Galdames, Francisco; Asahi, Takeshi; Pizarro, Daniel; Lobo, Gabriel

    2007-01-01

    In this paper we present a technique for fully automatic, real-time 3D SPECT (Single Photon Emitting Computed Tomography) and 2D ultrasound image registration. We use this technique in the context of kidney lesion diagnosis. Our registration algorithm allows a physician to perform an ultrasound exam after a SPECT image has been acquired and see in real time the registration of both modalities. An automatic segmentation algorithm has been implemented in order to display in 3D the positions of the acquired US images with respect to the organs. PMID:18044572

  17. Determination of left ventricular mass through SPECT imaging

    NASA Astrophysics Data System (ADS)

    Zárate-Morales, A.; Rodríguez-Villafuerte, M.; Martínez-Rodríguez, F.; Arévila-Ceballos, N.

    1998-08-01

    An edge detection algorithm has been applied to estimate left ventricular (LV) mass from single photon emission computed tomography (SPECT) thallium-201 images. The algorithm was validated using SPECT images of a phantom. The algorithm was applied to 20 patient studies from the Hospital de Cardiologia, Centro Médico Nacional Siglo XXI. Left ventricular masses derived from the stress and redistribution studies were highly correlated (r=0.96). The average LV masses obtained were 162±37 g and 169±34 g in the redistribution and stress studies, respectively.

  18. Determination of left ventricular mass through SPECT imaging

    SciTech Connect

    Zarate-Morales, A.; Rodriguez-Villafuerte, M.; Martinez-Rodriguez, F.; Arevila-Ceballos, N.

    1998-08-28

    An edge detection algorithm has been applied to estimate left ventricular (LV) mass from single photon emission computed tomography (SPECT) thallium-201 images. The algorithm was validated using SPECT images of a phantom. The algorithm was applied to 20 patient studies from the Hospital de Cardiologia, Centro Medico Nacional Siglo XXI. Left ventricular masses derived from the stress and redistribution studies were highly correlated (r=0.96). The average LV masses obtained were 162{+-}37 g and 169{+-}34 g in the redistribution and stress studies, respectively.

  19. A Investigation of Partially Extracted Tracers Used to Determine Myocardial Blood Flow with PET.

    NASA Astrophysics Data System (ADS)

    Christian, Bradley Thomas

    Positron Emission Tomography (PET) provides the ability to quantitatively measure mass-specific blood flow to myocardial tissue (ml/min/g tissue). The partially extracted tracers ^{62}Cu -PTSM and two single photon emission computed tomography(SPECT) agents, teboroxime and sestamibi were studied. The latter two demonstrate the effectiveness of PET as a pharmacological tool for SPECT perfusion tracer development. The characteristics of these tracers were compared to commonly used partially extracted tracers ^{13}rm NH_3 and ^{82} Rb. Positron emitting ^{rm 94m}Tc was used to label ligands originally developed for ^{rm 99m} Tc labeling. ^{rm 94m }Tc can be produced by the bombardment of a natural molybdenum foil with an 11Mev proton beam, via the ^{94}rm Mo(p,n)^ {94m}Tc reaction. The production of ^{rm94m}Tc is accompanied by ^{92}Tc, ^ {94}Tc, ^{95} Tc, ^{rm 95m}Tc, ^{96}Tc, and ^{rm 99m}Tc due to the isotopic mixture of natural Mo. The presence of these radionuclidic impurities increase the radiation dose received by the patient and radio chemist. The elimination of these impurities was achieved by irradiating an isotopically enriched target material, ^{94}rm MoO_3. The ability to reclaim the enriched target is essential due to the high cost of the material. Recovery was accomplished by a solvent extraction technique yielding an activity recovery of 80% and target material recovery of 95%. Preliminary data was measured for the myocardial perfusion tracer ^{62}Cu -PTSM. It was found that the uptake of ^ {62}Cu-PTSM is linear for resting flows but a high degree of variability is observed at stress induced flows. This same result was found in the human studies when compared to ^{13} rm NH_3 measured myocardial perfusion values. The dynamic analysis of multiple tracers in the sequence of protocols: (1) acute canine prep ( ^{11}rm CO, ^{82 }Rb, ^{62}Cu-PTSM, ^{13}rm NH_3, ^{94m,99m}Tc-BATO, H_2 ^{14}rm O, ^{18 }FCH_3), (2) chronic canine prep ( ^{82}rm Rb, ^{13 }NH_3

  20. Acute myocardial infarction

    PubMed Central

    Domes, Trustin; Szafran, Olga; Bilous, Cheryl; Olson, Odell; Spooner, G. Richard

    2006-01-01

    OBJECTIVE To assess the quality of care of acute myocardial infarction (AMI) in a rural health region. DESIGN Clinical audit employing multiple explicit criteria of care elements for emergency department and in-hospital AMI management. The audit was conducted using retrospective chart review. SETTING Twelve acute care health centres and hospitals in the East Central Health Region, a rural health region in Alberta, where medical and surgical services are provided almost entirely by family physicians. PARTICIPANTS Hospital inpatients with a confirmed discharge diagnosis of AMI (ICD-9-CM codes 410.xx) during the period April 1, 2001, to March 31, 2002, were included (177 confirmed cases). MAIN OUTCOME MEASURES Quality of AMI care was assessed using guidelines from the American College of Cardiology and the American Heart Association and the Canadian Cardiovascular Outcomes Research Team and Canadian Cardiovascular Society. Quality of care indicators at three stages of patient care were assessed: at initial recognition and AMI management in the emergency department, during in-hospital AMI management, and at preparation for discharge from hospital. RESULTS In the emergency department, the quality of care was high for most procedural and therapeutic audit elements, with the exception of rapid electrocardiography, urinalysis, and provision of nitroglycerin and morphine. Average door-to-needle time for thrombolysis was 102.5 minutes. The quality of in-hospital care was high for most elements, but low for nitroglycerin and angiotensin-converting enzyme (ACE) inhibitors, daily electrocardiography, and counseling regarding smoking cessation and diet. Few patients received counseling for lifestyle changes at hospital discharge. Male and younger patients were treated more aggressively than female and older patients. Sites that used care protocols achieved better results in initial AMI management than sites that did not. Stress testing was not readily available in the rural

  1. Myocardial contusion following nonfatal blunt chest trauma

    SciTech Connect

    Kumar, S.A.; Puri, V.K.; Mittal, V.K.; Cortez, J.

    1983-04-01

    Currently available diagnostic techniques for myocardial contusion following blunt chest trauma were evaluated. We investigated 30 patients prospectively over a period of 1 year for the presence of myocardial contusion. Among the 30 patients, eight were found to have myocardial contusion on the basis of abnormal electrocardiograms, elevated creatine phosphokinase MB fraction (CPK-MB), and positive myocardial scan. Myocardial scan was positive in seven of eight patients (87.5%). CPK-MB fraction was elevated in four of eight patients (50%). Definitive electrocardiographic changes were seen in only two of eight patients (25%). It appears that myocardial scan using technetium pyrophosphate and CPK-MB fraction determinations are the most reliable aids in diagnosis of myocardial contusion following blunt chest trauma.

  2. Spousal Adjustment to Myocardial Infarction.

    ERIC Educational Resources Information Center

    Ziglar, Elisa J.

    This paper reviews the literature on the stresses and coping strategies of spouses of patients with myocardial infarction (MI). It attempts to identify specific problem areas of adjustment for the spouse and to explore the effects of spousal adjustment on patient recovery. Chapter one provides an overview of the importance in examining the…

  3. [Sewer gas induced myocardial toxicity].

    PubMed

    Antonelli, Dante; Sabanchiev, Avi; Rosner, Ehud; Turgeman, Yoav

    2014-07-01

    We report the case of a 19 year-old worker who collapsed after acute exposure to sewer gas. He rapidly developed cardiorespiratory failure with electrocardiographic, echocardiographic and laboratory findings of myocardial involvement. The mainstay of the therapy was mainly supportive treatment with a successful outcome. PMID:25189024

  4. Thrombolysis for Acute Myocardial Infarction

    PubMed Central

    Webb, John; Thompson, Christopher

    1992-01-01

    Thrombolysis has an important role in the management of acute myocardial infarction. Early treatment can markedly reduce mortality and morbidity. This new standard of care requires knowledge of accepted indications and contraindications for thrombolysis as well as familiarity with available agents and regimens. ImagesFigure 3 PMID:21221398

  5. Effects of scatter modeling on time-activity curves estimated directly from dynamic SPECT projections

    SciTech Connect

    Reutter, Bryan W.; Gullberg, Grant T.; Huesman, Ronald H.

    2003-10-29

    Quantitative analysis of uptake and washout of cardiac single photon emission computed tomography (SPECT) radiopharmaceuticals has the potential to provide better contrast between healthy and diseased tissue, compared to conventional reconstruction of static images. Previously, we used B-splines to model time-activity curves (TACs) for segmented volumes of interest and developed fast least-squares algorithms to estimate spline TAC coefficients and their statistical uncertainties directly from dynamic SPECT projection data. This previous work incorporated physical effects of attenuation and depth-dependent collimator response. In the present work, we incorporate scatter and use a computer simulation to study how scatter modeling affects directly estimated TACs and subsequent estimates of compartmental model parameters. An idealized single-slice emission phantom was used to simulate a 15 min dynamic {sup 99m}Tc-teboroxime cardiac patient study in which 500,000 events containing scatter were detected from the slice. When scatter was modeled, unweighted least-squares estimates of TACs had root mean square (RMS) error that was less than 0.6% for normal left ventricular myocardium, blood pool, liver, and background tissue volumes and averaged 3% for two small myocardial defects. When scatter was not modeled, RMS error increased to average values of 16% for the four larger volumes and 35% for the small defects. Noise-to-signal ratios (NSRs) for TACs ranged between 1-18% for the larger volumes and averaged 110% for the small defects when scatter was modeled. When scatter was not modeled, NSR improved by average factors of 1.04 for the larger volumes and 1.25 for the small defects, as a result of the better-posed (though more biased) inverse problem. Weighted least-squares estimates of TACs had slightly better NSR and worse RMS error, compared to unweighted least-squares estimates. Compartmental model uptake and washout parameter estimates obtained from the TACs were less

  6. Anatomical-based partial volume correction for low-dose dedicated cardiac SPECT/CT.

    PubMed

    Liu, Hui; Chan, Chung; Grobshtein, Yariv; Ma, Tianyu; Liu, Yaqiang; Wang, Shi; Stacy, Mitchel R; Sinusas, Albert J; Liu, Chi

    2015-09-01

    Due to the limited spatial resolution, partial volume effect has been a major degrading factor on quantitative accuracy in emission tomography systems. This study aims to investigate the performance of several anatomical-based partial volume correction (PVC) methods for a dedicated cardiac SPECT/CT system (GE Discovery NM/CT 570c) with focused field-of-view over a clinically relevant range of high and low count levels for two different radiotracer distributions. These PVC methods include perturbation geometry transfer matrix (pGTM), pGTM followed by multi-target correction (MTC), pGTM with known concentration in blood pool, the former followed by MTC and our newly proposed methods, which perform the MTC method iteratively, where the mean values in all regions are estimated and updated by the MTC-corrected images each time in the iterative process. The NCAT phantom was simulated for cardiovascular imaging with (99m)Tc-tetrofosmin, a myocardial perfusion agent, and (99m)Tc-red blood cell (RBC), a pure intravascular imaging agent. Images were acquired at six different count levels to investigate the performance of PVC methods in both high and low count levels for low-dose applications. We performed two large animal in vivo cardiac imaging experiments following injection of (99m)Tc-RBC for evaluation of intramyocardial blood volume (IMBV). The simulation results showed our proposed iterative methods provide superior performance than other existing PVC methods in terms of image quality, quantitative accuracy, and reproducibility (standard deviation), particularly for low-count data. The iterative approaches are robust for both (99m)Tc-tetrofosmin perfusion imaging and (99m)Tc-RBC imaging of IMBV and blood pool activity even at low count levels. The animal study results indicated the effectiveness of PVC to correct the overestimation of IMBV due to blood pool contamination. In conclusion, the iterative PVC methods can achieve more accurate quantification, particularly

  7. Anatomical-based partial volume correction for low-dose dedicated cardiac SPECT/CT

    NASA Astrophysics Data System (ADS)

    Liu, Hui; Chan, Chung; Grobshtein, Yariv; Ma, Tianyu; Liu, Yaqiang; Wang, Shi; Stacy, Mitchel R.; Sinusas, Albert J.; Liu, Chi

    2015-09-01

    Due to the limited spatial resolution, partial volume effect has been a major degrading factor on quantitative accuracy in emission tomography systems. This study aims to investigate the performance of several anatomical-based partial volume correction (PVC) methods for a dedicated cardiac SPECT/CT system (GE Discovery NM/CT 570c) with focused field-of-view over a clinically relevant range of high and low count levels for two different radiotracer distributions. These PVC methods include perturbation geometry transfer matrix (pGTM), pGTM followed by multi-target correction (MTC), pGTM with known concentration in blood pool, the former followed by MTC and our newly proposed methods, which perform the MTC method iteratively, where the mean values in all regions are estimated and updated by the MTC-corrected images each time in the iterative process. The NCAT phantom was simulated for cardiovascular imaging with 99mTc-tetrofosmin, a myocardial perfusion agent, and 99mTc-red blood cell (RBC), a pure intravascular imaging agent. Images were acquired at six different count levels to investigate the performance of PVC methods in both high and low count levels for low-dose applications. We performed two large animal in vivo cardiac imaging experiments following injection of 99mTc-RBC for evaluation of intramyocardial blood volume (IMBV). The simulation results showed our proposed iterative methods provide superior performance than other existing PVC methods in terms of image quality, quantitative accuracy, and reproducibility (standard deviation), particularly for low-count data. The iterative approaches are robust for both 99mTc-tetrofosmin perfusion imaging and 99mTc-RBC imaging of IMBV and blood pool activity even at low count levels. The animal study results indicated the effectiveness of PVC to correct the overestimation of IMBV due to blood pool contamination. In conclusion, the iterative PVC methods can achieve more accurate quantification, particularly for low

  8. Small hepatocellular carcinomas in chronic liver disease: Detection with SPECT

    SciTech Connect

    Kudo, M.; Hirasa, M.; Takakuwa, H.; Ibuki, Y.; Fujimi, K.; Miyamura, M.; Tomita, S.; Komori, H.; Todo, A.; Kitaura, Y.

    1986-06-01

    Single-photon emission computed tomography (SPECT) performed using a rotating gamma camera was compared with ..cap alpha../sub 1/-fetoprotein (AFP) assay, conventional liver scintigraphy, ultrasound (US) imaging, computed tomography (CT), and selective celiac angiography in 40 patients with a total of 50 small hepatocellular carcinomas (HCCs;<5 cm). The detection rates of US and CT were determined on an initial screening study and on a second, more precisely focused study. The detection rate of small HCCs by the various modalities was as follows: AFP, 13%; liver scintigraphy, 36%; SPECT, 72%; initial screening US, 80%; second, more precise US studies, 94%; initial screening CT, 64%; second, more precise CT study, 82%; angiography, 88%. Although SPECT was inferior to the initial screening US examination in detecting HCCs less than 2 cm in size, its sensitivity was identical to that of the initial screening US study for detecting HCCs of 2-5 cm. The combination of SPECT and US was an excellent method for the early detection of HCCs, yielding a detection rate of 94%.

  9. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    PubMed Central

    Baba, Justin S.; Endres, Christopher J.; Foss, Catherine A.; Nimmagadda, Sridhar; Jung, Hyeyun; Goddard, James S.; Lee, Seungjoon; McKisson, John; Smith, Mark F.; Stolin, Alexander V.; Weisenberger, Andrew G.; Pomper, Martin G.

    2014-01-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a 99mTc-pertechnetate phantom, 99mTcmethylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand 123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of 123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake. PMID:23536223

  10. Nonlinear dual reconstruction of SPECT activity and attenuation images.

    PubMed

    Liu, Huafeng; Guo, Min; Hu, Zhenghui; Shi, Pengcheng; Hu, Hongjie

    2014-01-01

    In single photon emission computed tomography (SPECT), accurate attenuation maps are needed to perform essential attenuation compensation for high quality radioactivity estimation. Formulating the SPECT activity and attenuation reconstruction tasks as coupled signal estimation and system parameter identification problems, where the activity distribution and the attenuation parameter are treated as random variables with known prior statistics, we present a nonlinear dual reconstruction scheme based on the unscented Kalman filtering (UKF) principles. In this effort, the dynamic changes of the organ radioactivity distribution are described through state space evolution equations, while the photon-counting SPECT projection data are measured through the observation equations. Activity distribution is then estimated with sub-optimal fixed attenuation parameters, followed by attenuation map reconstruction given these activity estimates. Such coupled estimation processes are iteratively repeated as necessary until convergence. The results obtained from Monte Carlo simulated data, physical phantom, and real SPECT scans demonstrate the improved performance of the proposed method both from visual inspection of the images and a quantitative evaluation, compared to the widely used EM-ML algorithms. The dual estimation framework has the potential to be useful for estimating the attenuation map from emission data only and thus benefit the radioactivity reconstruction. PMID:25225796

  11. Thallium-201 accumulation in cerebral candidiasis: Unexpected finding on SPECT

    SciTech Connect

    Tonami, N.; Matsuda, H.; Ooba, H.; Yokoyama, K.; Hisada, K.; Ikeda, K.; Yamashita, J. )

    1990-06-01

    The authors present an unexpected finding of Tl-201 uptake in the intracerebral lesions due to candidiasis. SPECT demonstrated the extent of the lesions and a high target-to-background ratio. The regions where abnormal Tl-201 accumulation was seen were nearly consistent with CT scans of those enhanced by a contrast agent. After treatment, most of the abnormal Tl-201 accumulation disappeared.

  12. Hemimegalencephaly: Clinical, EEG, neuroimaging, and IMP-SPECT correlation

    SciTech Connect

    Konkol, R.J.; Maister, B.H.; Wells, R.G.; Sty, J.R. )

    1990-11-01

    Iofetamine-single photon emission computed tomography (IMP-SPECT) was performed on 2 girls (5 1/2 and 6 years of age) with histories of intractable seizures, developmental delay, and unilateral hemiparesis secondary to hemimegalencephaly. Electroencephalography (EEG) revealed frequent focal discharges in 1 patient, while a nearly continuous burst suppression pattern over the malformed hemisphere was recorded in the other. IMP-SPECT demonstrated a good correlation with neuroimaging studies. In spite of the different EEG patterns, which had been proposed to predict contrasting clinical outcomes, both IMP-SPECT scans disclosed a similar decrease in tracer uptake in the malformed hemisphere. These results are consistent with the pattern of decreased tracer uptake found in other interictal studies of focal seizures without cerebral malformations. In view of recent recommendations for hemispherectomy in these patients, we suggest that the IMP-SPECT scan be used to compliment EEG as a method to define the extent of abnormality which may be more relevant to long-term prognosis than EEG alone.

  13. Simplifying the Measurement of Gastric Accommodation using SPECT

    PubMed Central

    Vijayvargiya, Priya; Camilleri, Michael; Shin, Andrea; Breen, Mary; Burton, Duane

    2013-01-01

    Background Noninvasive single photon emission computed tomography (SPECT) has been validated as a test for postprandial gastric volume accommodation, with volumes measured twice over 30 minutes and averaged. The purpose of this study is to simplify the SPECT measurement of gastric accommodation. Methods The primary aim of this study was to compare 2 postprandial gastric volume measurements with data collected retrospectively from 443 patients and healthy volunteers who had undergone SPECT in the last decade. The differences in the two gastric volumes were compared in the entire group and each subgroup, and the correlation between the 2 measurements and their differences across a wide range of gastric volumes were plotted. Key Results There was a median difference of <2% (p=0.041) between postprandial scan 1 (757 mL) and scan 2 (743 mL), with significant correlation (rs = 0.859, p<0.01) and excellent agreement (S.D. 60 mL) between the 2 scans across the entire range of observed postprandial gastric volumes. Conclusions & Inferences A single postprandial scan can detect gastric accommodation with the same accuracy as averaging 2 postprandial scans. These data support simplifying SPECT measurement of postprandial gastric volume with a scan in the first 15 minutes after a meal. PMID:23413813

  14. The role of SPECT in the evaluation of skeletal trauma.

    PubMed

    Murray, I P

    1993-02-01

    Single photon emission computed tomography (SPECT) has, in the last decade, established a critical role in routine diagnosis. Skeletal scintigraphy exemplifies the impact in improving detection of lesions by delineation of their site and size. The advantage of minimizing the superimposed radioactivity from overlying and underlying structures is typified by the readiness with which avascular necrosis of the femoral head can be identified by removal of the surrounding hyperaemia which masks the classical photopaenia. However, the ability to achieve an accurate image at a plane at a prescribed depth is most characteristically shown by the study of a vertebra, a bone of irregular contour and subject to a variety of pathological disorders at different sites within it. The various focal abnormalities resulting from these can be localized exactly, readily distinguishing, for example, those in the body from those in the natural arch. In particular, the alterations resulting from trauma, such as pars interarticularis stress fracture, are readily seen. Consequently SPECT has an indispensable role in the investigation and management of low back pain. However, the ability of SPECT to delineate abnormal accumulation has provided a new approach to the evaluation of knee pain, especially when acute such as that resulting from athletic injury, since the identification of the presence or absence of focal abnormalities can be critical to patient management. The frequency of these various disorders in which SPECT is so useful explains why the procedure has become such a routine high-volume examination is so many departments. PMID:8461235

  15. Nonlinear Dual Reconstruction of SPECT Activity and Attenuation Images

    PubMed Central

    Liu, Huafeng; Guo, Min; Hu, Zhenghui; Shi, Pengcheng; Hu, Hongjie

    2014-01-01

    In single photon emission computed tomography (SPECT), accurate attenuation maps are needed to perform essential attenuation compensation for high quality radioactivity estimation. Formulating the SPECT activity and attenuation reconstruction tasks as coupled signal estimation and system parameter identification problems, where the activity distribution and the attenuation parameter are treated as random variables with known prior statistics, we present a nonlinear dual reconstruction scheme based on the unscented Kalman filtering (UKF) principles. In this effort, the dynamic changes of the organ radioactivity distribution are described through state space evolution equations, while the photon-counting SPECT projection data are measured through the observation equations. Activity distribution is then estimated with sub-optimal fixed attenuation parameters, followed by attenuation map reconstruction given these activity estimates. Such coupled estimation processes are iteratively repeated as necessary until convergence. The results obtained from Monte Carlo simulated data, physical phantom, and real SPECT scans demonstrate the improved performance of the proposed method both from visual inspection of the images and a quantitative evaluation, compared to the widely used EM-ML algorithms. The dual estimation framework has the potential to be useful for estimating the attenuation map from emission data only and thus benefit the radioactivity reconstruction. PMID:25225796

  16. V/Q SPECT: utility for investigation of pulmonary physiology.

    PubMed

    King, Gregory G; Harris, Benjamin; Mahadev, Sriram

    2010-11-01

    Single-photon emission computed tomography (SPECT) is being increasingly used as a tool in respiratory research, in particular ventilation SPECT. Much of the basic understanding of pulmonary physiology has been derived from inhaled radioactive inert gases because, as the lung behaves in an asymmetric manner, the nature of regional differences in ventilation is ideally studied with the use of imaging. It is well known to clinicians that ventilation is patchy in patients who have airways disease. However, the relevance to the disease mechanisms itself only started to be studied with the use of 3-dimensional imaging and with advances in quantitative image analysis. The measurements of both ventilation distribution and nonventilation (airway closure) have become very topical in the study of asthma, and accurate quantification of those parameters is of relevance to disease mechanisms. In chronic obstructive pulmonary disease, the drive is towards better characterization of disease groups ("phenotypes") and, again, description of ventilation patterns may prove to be useful. This is a review, therefore, on pulmonary SPECT imaging in respiratory research which includes a focus on methodology in relation to respiratory physiology. There has been relatively little published in this area but there is great potential for advances in the understanding of airways disease to be gained from SPECT imaging. PMID:20920636

  17. Geometric characterization of multi-axis multi-pinhole SPECT

    SciTech Connect

    DiFilippo, Frank P.

    2008-01-15

    A geometric model and calibration process are developed for single photon emission computed tomography (SPECT) imaging with multiple pinholes and multiple mechanical axes. Unlike the typical situation where pinhole collimators are mounted directly to rotating gamma ray detectors, this geometric model allows for independent rotation of the detectors and pinholes, for the case where the pinhole collimator is physically detached from the detectors. This geometric model is applied to a prototype small animal SPECT device with a total of 22 pinholes and which uses dual clinical SPECT detectors. All free parameters in the model are estimated from a calibration scan of point sources and without the need for a precision point source phantom. For a full calibration of this device, a scan of four point sources with 360 deg. rotation is suitable for estimating all 95 free parameters of the geometric model. After a full calibration, a rapid calibration scan of two point sources with 180 deg. rotation is suitable for estimating the subset of 22 parameters associated with repositioning the collimation device relative to the detectors. The high accuracy of the calibration process is validated experimentally. Residual differences between predicted and measured coordinates are normally distributed with 0.8 mm full width at half maximum and are estimated to contribute 0.12 mm root mean square to the reconstructed spatial resolution. Since this error is small compared to other contributions arising from the pinhole diameter and the detector, the accuracy of the calibration is sufficient for high resolution small animal SPECT imaging.

  18. [Radionuclide cisternography: SPECT- and 3D-technique].

    PubMed

    Henkes, H; Huber, G; Hierholzer, J; Cordes, M; Kujat, C; Piepgras, U

    1991-10-01

    Radionuclide cisternography is indicated in the clinical work-up for hydrocephalus, when searching for CSF leaks, and when testing whether or not intracranial cystic lesions are communicating with the adjacent subarachnoid space. This paper demonstrates the feasibility and diagnostic value of SPECT and subsequent 3D surface rendering in addition to conventional rectilinear CSF imaging in eight patients. Planar images allowed the evaluation of CSF circulation and the detection of CSF fistula. They were advantageous in examinations 48 h after application of 111In-DTPA. SPECT scans, generated 4-24 h after tracer application, were superior in the delineation of basal cisterns, especially in early scans; this was helpful in patients with pooling due to CSF fistula and in cystic lesions near the skull base. A major drawback was the limited image quality of delayed scans, when the SPECT data were degraded by a low count rate. 3D surface rendering was easily feasible from SPECT data and yielded high quality images. The presentation of the spatial distribution of nuclide-contaminated CSF proved especially helpful in the area of the basal cisterns. PMID:1956980

  19. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    SciTech Connect

    Baba, Justin S.; Endres, Christopher J.; Foss, Catherine A.; Nimmagadda, Sridhar; Jung, Hyeyun; Goddard, James S.; Lee, Seung Joon; McKisson, John; Smith, Mark F.; Stolin, Alexander V.; Weisenberger, Andrew G.; Pomper, Martin G.

    2013-06-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a ^99mTc-pertechnetate phantom, ^99mTc-methylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand ^123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of ^123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.

  20. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    SciTech Connect

    Baba, Justin S; Endres, Christopher; Foss, Catherine; Nimmagadda, Sridhar; Jung, Hyeyun; Goddard Jr, James Samuel; Lee, Seung Joon; McKisson, John; Smith, Mark F.; Stolin, Alexander; Weisenberger, Andrew G.; Pomper, Martin

    2013-01-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a 99mTc-pertechnetate phantom, 99mTcmethylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand 123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of 123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.

  1. A COMPUTER MODEL OF LUNG MORPHOLOGY TO ANALYZE SPECT IMAGES

    EPA Science Inventory

    Measurement of the three-dimensional (3-D) spatial distribution of aerosol deposition can be performed using Single Photon Emission Computed Tomography (SPECT). The advantage of using 3-D techniques over planar gamma imaging is that deposition patterns can be related to real lun...

  2. Collimator design for a multipinhole brain SPECT insert for MRI

    SciTech Connect

    Van Audenhaege, Karen; Van Holen, Roel; Vanhove, Christian; Vandenberghe, Stefaan

    2015-11-15

    Purpose: Brain single photon emission computed tomography (SPECT) imaging is an important clinical tool, with unique tracers for studying neurological diseases. Nowadays, most commercial SPECT systems are combined with x-ray computed tomography (CT) in so-called SPECT/CT systems to obtain an anatomical background for the functional information. However, while CT images have a high spatial resolution, they have a low soft-tissue contrast, which is an important disadvantage for brain imaging. Magnetic resonance imaging (MRI), on the other hand, has a very high soft-tissue contrast and does not involve extra ionizing radiation. Therefore, the authors designed a brain SPECT insert that can operate inside a clinical MRI. Methods: The authors designed and simulated a compact stationary multipinhole SPECT insert based on digital silicon photomultiplier detector modules, which have shown to be MR-compatible and have an excellent intrinsic resolution (0.5 mm) when combined with a monolithic 2 mm thick LYSO crystal. First, the authors optimized the different parameters of the SPECT system to maximize sensitivity for a given target resolution of 7.2 mm in the center of the field-of-view, given the spatial constraints of the MR system. Second, the authors performed noiseless simulations of two multipinhole configurations to evaluate sampling and reconstructed resolution. Finally, the authors performed Monte Carlo simulations and compared the SPECT insert with a clinical system with ultrahigh-resolution (UHR) fan beam collimators, based on contrast-to-noise ratio and a visual comparison of a Hoffman phantom with a 9 mm cold lesion. Results: The optimization resulted in a stationary multipinhole system with a collimator radius of 150.2 mm and a detector radius of 172.67 mm, which corresponds to four rings of 34 diSPM detector modules. This allows the authors to include eight rings of 24 pinholes, which results in a system volume sensitivity of 395 cps/MBq. Noiseless simulations

  3. Calpain inhibition preserves myocardial structure and function following myocardial infarction.

    PubMed

    Mani, Santhosh K; Balasubramanian, Sundaravadivel; Zavadzkas, Juozas A; Jeffords, Laura B; Rivers, William T; Zile, Michael R; Mukherjee, Rupak; Spinale, Francis G; Kuppuswamy, Dhandapani

    2009-11-01

    Cardiac pathology, such as myocardial infarction (MI), activates intracellular proteases that often trigger programmed cell death and contribute to maladaptive changes in myocardial structure and function. To test whether inhibition of calpain, a Ca(2+)-dependent cysteine protease, would prevent these changes, we used a mouse MI model. Calpeptin, an aldehydic inhibitor of calpain, was intravenously administered at 0.5 mg/kg body wt before MI induction and then at the same dose subcutaneously once per day. Both calpeptin-treated (n = 6) and untreated (n = 6) MI mice were used to study changes in myocardial structure and function after 4 days of MI, where end-diastolic volume (EDV) and left ventricular ejection fraction (EF) were measured by echocardiography. Calpain activation and programmed cell death were measured by immunohistochemistry, Western blotting, and TdT-mediated dUTP nick-end labeling (TUNEL). In MI mice, calpeptin treatment resulted in a significant improvement in EF [EF decreased from 67 + or - 2% pre-MI to 30 + or - 4% with MI only vs. 41 + or - 2% with MI + calpeptin] and attenuated the increase in EDV [EDV increased from 42 + or - 2 microl pre-MI to 73 + or - 4 microl with MI only vs. 55 + or - 4 microl with MI + calpeptin]. Furthermore, calpeptin treatment resulted in marked reduction in calpain- and caspase-3-associated changes and TUNEL staining. These studies indicate that calpain contributes to MI-induced alterations in myocardial structure and function and that it could be a potential therapeutic target in treating MI patients. PMID:19734364

  4. Partial volume correction in SPECT reconstruction with OSEM

    NASA Astrophysics Data System (ADS)

    Erlandsson, Kjell; Thomas, Ben; Dickson, John; Hutton, Brian F.

    2011-08-01

    SPECT images suffer from poor spatial resolution, which leads to partial volume effects due to cross-talk between different anatomical regions. By utilising high-resolution structural images (CT or MRI) it is possible to compensate for these effects. Traditional partial volume correction (PVC) methods suffer from various limitations, such as correcting a single region only, returning only regional mean values, or assuming a stationary point spread function (PSF). We recently presented a novel method in which PVC was combined with the reconstruction process in order to take into account the distance dependent PSF in SPECT, which was based on filtered backprojection (FBP) reconstruction. We now present a new method based on the iterative OSEM algorithm, which has advantageous noise properties compared to FBP. We have applied this method to a series of 10 brain SPECT studies performed on healthy volunteers using the DATSCAN tracer. T1-weighted MRI images were co-registered to the SPECT data and segmented into 33 anatomical regions. The SPECT data were reconstructed using OSEM, and PVC was applied in the projection domain at each iteration. The correction factors were calculated by forward projection of a piece-wise constant image, generated from the segmented MRI. Images were also reconstructed using FBP and standard OSEM with and without resolution recovery (RR) for comparison. The images were evaluated in terms of striatal contrast and regional variability (CoV). The mean striatal contrast obtained with OSEM, OSEM-RR and OSEM-PVC relative to FBP were 1.04, 1.42 and 1.53, respectively, and the mean striatal CoV values are 1.05, 1.53, 1.07. Both OSEM-RR and OSEM-PVC results in images with significantly higher contrast as compared to FBP or OSEM, but OSEM-PVC avoids the increased regional variability of OSEM-RR due to improved structural definition.

  5. Imaging and Modeling of Myocardial Metabolism

    PubMed Central

    Jamshidi, Neema; Karimi, Afshin; Birgersdotter-Green, Ulrika; Hoh, Carl

    2010-01-01

    Current imaging methods have focused on evaluation of myocardial anatomy and function. However, since myocardial metabolism and function are interrelated, metabolic myocardial imaging techniques, such as positron emission tomography, single photon emission tomography, and magnetic resonance spectroscopy present novel opportunities for probing myocardial pathology and developing new therapeutic approaches. Potential clinical applications of metabolic imaging include hypertensive and ischemic heart disease, heart failure, cardiac transplantation, as well as cardiomyopathies. Furthermore, response to therapeutic intervention can be monitored using metabolic imaging. Analysis of metabolic data in the past has been limited, focusing primarily on isolated metabolites. Models of myocardial metabolism, however, such as the oxygen transport and cellular energetics model and constraint-based metabolic network modeling, offer opportunities for evaluation interactions between greater numbers of metabolites in the heart. In this review, the roles of metabolic myocardial imaging and analysis of metabolic data using modeling methods for expanding our understanding of cardiac pathology are discussed. PMID:20559785

  6. Perioperative myocardial ischemia reperfusion injury.

    PubMed

    Shernan, Stanton K

    2003-09-01

    Myocardial I-R injury contributes to adverse cardiovascular outcomes after cardiac surgery. The pathogenesis of I-R injury is complex and involves the activation, coordination, and amplification of several systemic and local proinflammatory pathways (Fig. 4). Treatment and prevention of perioperative morbidity associated with myocardial I-R will ultimately require a multifocal approach. Combining preoperative risk stratification (co-morbidity and surgical complexity), minimizing initiating factors predisposing to SIRS, limiting ischemia duration, and administering appropriate immunotherapy directed toward systemic and local proinflammatory mediators of I-R injury, should all be considered. In addition, the role of the genetic-environmental interactions in the pathogenesis of cardiovascular disease is also being examined. Thus, in the near future, preoperative screening for polymorphisms of certain inflammatory and coagulation genes should inevitably help reduce morbidity by permitting the identification of high-risk cardiac surgical patients and introducing the opportunity for gene therapy or pharmacogenetic intervention [42,64]. PMID:14562561

  7. Myocardialization of the cardiac outflow tract

    NASA Technical Reports Server (NTRS)

    van den Hoff, M. J.; Moorman, A. F.; Ruijter, J. M.; Lamers, W. H.; Bennington, R. W.; Markwald, R. R.; Wessels, A.

    1999-01-01

    During development, the single-circuited cardiac tube transforms into a double-circuited four-chambered heart by a complex process of remodeling, differential growth, and septation. In this process the endocardial cushion tissues of the atrioventricular junction and outflow tract (OFT) play a crucial role as they contribute to the mesenchymal components of the developing septa and valves in the developing heart. After fusion, the endocardial ridges in the proximal portion of the OFT initially form a mesenchymal outlet septum. In the adult heart, however, this outlet septum is basically a muscular structure. Hence, the mesenchyme of the proximal outlet septum has to be replaced by cardiomyocytes. We have dubbed this process "myocardialization." Our immunohistochemical analysis of staged chicken hearts demonstrates that myocardialization takes place by ingrowth of existing myocardium into the mesenchymal outlet septum. Compared to other events in cardiac septation, it is a relatively late process, being initialized around stage H/H28 and being basically completed around stage H/H38. To unravel the molecular mechanisms that are responsible for the induction and regulation of myocardialization, an in vitro culture system in which myocardialization could be mimicked and manipulated was developed. Using this in vitro myocardialization assay it was observed that under the standard culture conditions (i) whole OFT explants from stage H/H20 and younger did not spontaneously myocardialize the collagen matrix, (ii) explants from stage H/H21 and older spontaneously formed extensive myocardial networks, (iii) the myocardium of the OFT could be induced to myocardialize and was therefore "myocardialization-competent" at all stages tested (H/H16-30), (iv) myocardialization was induced by factors produced by, most likely, the nonmyocardial component of the outflow tract, (v) at none of the embryonic stages analyzed was ventricular myocardium myocardialization-competent, and finally

  8. Acute care of myocardial infarction.

    PubMed Central

    Gutman, M. B.; Lee, T. F.; Gin, K.; Ho, K.

    1996-01-01

    Patients with acute myocardial infarct (AMI) need rapid diagnosis and prompt initiation of thrombolytic therapy. Patients with suspected cardiac ischemia must receive a coordinated team response by the emergency room staff including rapid electrocardiographic analysis and a quick but thorough history and physical examination to diagnose AMI. Thrombolysis and adjunct therapies should be administered promptly when indicated. The choice of thrombolytics is predicated by the location of the infarct. PMID:8754702

  9. Myocardial Infarction in the Elderly

    PubMed Central

    Carro, Amelia; Kaski, Juan Carlos

    2011-01-01

    Advances in pharmacological treatment and effective early myocardial revascularization have –in recent years- led to improved clinical outcomes in patients with acute myocardial infarction (AMI). However, it has been suggested that compared to younger subjects, elderly AMI patients are less likely to receive evidence-based treatment, including myocardial revascularization therapy. Several reasons have been postulated to explain this trend, including uncertainty regarding the true benefits of the interventions commonly used in this setting as well as increased risk mainly associated with comorbidities. The diagnosis, management, and post-hospitalization care of elderly patients presenting with an acute coronary syndrome pose many difficulties at present. A complex interplay of variables such as comorbidities, functional and socioeconomic status, side effects associated with multiple drug administration, and individual biologic variability, all contribute to creating a complex clinical scenario. In this complex setting, clinicians are often required to extrapolate evidence-based results obtained in cardiovascular trials from which older patients are often, implicitly or explicitly, excluded. This article reviews current recommendations regarding management of AMI in the elderly. PMID:22396870

  10. Percutaneous Intramyocardial Delivery of Mesenchymal Stem Cells Induces Superior Improvement in Regional Left Ventricular Function Compared with Bone Marrow Mononuclear Cells in Porcine Myocardial Infarcted Heart

    PubMed Central

    Tao, Bo; Cui, Mingliang; Wang, Chen; Ma, Sai; Wu, Feng; Yi, Fu; Qin, Xing; Liu, Junting; Wang, Haichang; Wang, Zhe; Ma, Xiaowei; Tian, Jie; Chen, Yundai; Wang, Jing; Cao, Feng

    2015-01-01

    Aim: To investigate the efficacy and feasibility of percutaneous intramyocardial injection of bone marrow mesenchymal stem cells (MSC) and autologous bone marrow-derived mononuclear cells (BMMNC) on cardiac functional improvement in porcine myocardial infarcted hearts. Methods and Results: Acute myocardial infarction (AMI) was induced in 22 minipigs by temporary balloon occlusion of the left anterior descending coronary artery for 60min.Two weeks post AMI, BMMNC (n = 7, 245 ± 98×106), MSC (n = 8, 56 ± 17×106), or phosphate buffered saline (PBS; n = 7) were injected intramyocardially. Cardiac function and myocardial perfusion were analyzed by echocardiography and gated single-photon emission computed tomography/computed tomography (SPECT/CT) at 1 week before AMI and 2 and 10 weeks after AMI. Cell engraftment, proliferation, vascular density, and cardiac fibrosis were evaluated by histology analysis. In all groups, the echocardiography revealed no significant change in the left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV), or left ventricular end-diastolic volume (LVEDV) at 10 weeks after AMI compared with those at 2 weeks after AMI. However, the wall motion score index (WMSI) and left ventricular systolic wall thickening (WT%) were significantly improved at 10 weeks compared with those at 2 weeks after AMI in the MSC group (WMSI 1.55 ± 0.06 vs. 1.87 ± 0.10, WT 33.4 ± 2.3% vs.24.8 ± 2.7%,p < 0.05) but not in the BMMNC group. In addition, myocardial perfusion quantified by SPECT/CT was improved in both the MSC and BMMNC groups, whereas the MSC group showed a superior improvement in vascular density and collagen volume fraction (p < 0.05). Conclusion: This preclinically relevant study suggests that when delivered by percutaneous (transcatheter) intramyocardial injection, MSC might be more effective than BMMNC to improve ischemia and reperfusion after AMI. PMID:25553108

  11. [Vectorcardiographic diagnosis of the myocardial inactivatable zone].

    PubMed

    de Micheli, A; Medrano, G A

    1989-01-01

    Clinical importance of the vectorcardiographic exploration (distant and spatial) of the myocardial electrical phenomenon is emphasized. This technique constitutes a useful integration of electrocardiographic exploration (near and analytical). The more characteristic morphological and chronological changes due to an inactivatable area are discussed in the light of ventricular myocardial depolarization. Some typical vectorcardiographic features corresponding to the presence of a myocardial inactivatable zone are presented. The utility of the complementary elements which vectorcardiography can bring to electrocardiography is emphasized. Both of these procedures integrate a rational exploration of electrical activity of the myocardium, the solid base of prognostic and therapeutic decisions in cases of myocardial infarction. PMID:2669657

  12. Myocardial perfusion imaging using contrast echocardiography.

    PubMed

    Pathan, Faraz; Marwick, Thomas H

    2015-01-01

    Microbubbles are an excellent intravascular tracer, and both the rate of myocardial opacification (analogous to coronary microvascular perfusion) and contrast intensity (analogous to myocardial blood volume) provide unique insights into myocardial perfusion. A strong evidence base has been accumulated to show comparability with nuclear perfusion imaging and incremental diagnostic and prognostic value relative to wall motion analysis. This technique also provides the possibility to measure myocardial perfusion at the bedside. Despite all of these advantages, the technique is complicated, technically challenging, and has failed to scale legislative and financial hurdles. The development of targeted imaging and therapeutic interventions will hopefully rekindle interest in this interesting modality. PMID:25817740

  13. Myocardial ischaemia during tracheal intubation and extubation.

    PubMed

    Edwards, N D; Alford, A M; Dobson, P M; Peacock, J E; Reilly, C S

    1994-10-01

    The incidence of myocardial ischaemia during tracheal intubation and extubation was compared using ambulatory ECG monitoring in 60 patients undergoing a variety of different surgical operations. Seven patients had myocardial ischaemia after tracheal intubation and seven patients during tracheal extubation. The patients who developed myocardial ischaemia during tracheal extubation had significantly greater rate-pressure products immediately before tracheal extubation (P < 0.05) and 1 min after tracheal extubation (P < 0.01) compared with those patients who did not develop myocardial ischaemia during extubation. PMID:7999498

  14. Novel Cadmium Zinc Telluride Devices for Myocardial Perfusion Imaging-Technological Aspects and Clinical Applications.

    PubMed

    Ben-Haim, Simona; Kennedy, John; Keidar, Zohar

    2016-07-01

    Myocardial perfusion imaging plays an important role in the assessment of patients with known or suspected coronary artery disease and is well established for diagnosis and for prognostic evaluation in these patients. The dedicated cardiac SPECT cameras with solid-state cadmium zinc telluride (CZT) detectors were first introduced a decade ago. A large body of evidence is building up, showing the superiority of the new technology compared with conventional gamma cameras. Not only the CZT detectors, but also new collimator geometries, the ability to perform focused imaging optimized for the heart and advances in data processing algorithms all contribute to the significantly improved sensitivity up to 8-10 times, as well as improved energy resolution and improved reconstructed spatial resolution compared with conventional technology. In this article, we provide an overview of the physical characteristics of the CZT cameras, as well as a review of the literature published so far, including validation studies in comparison with conventional myocardial perfusion imaging and with invasive coronary angiography, significant reduction in radiation dose, and new imaging protocols enabled by the new technology. PMID:27237438

  15. [Thallium-201 myocardial perfusion imaging during adenosine-induced coronary vasodilation in patients with ischemic heart disease].

    PubMed

    Takeishi, Y; Chiba, J; Abe, S; Ikeda, K; Tonooka, I; Komatani, A; Takahashi, K; Nakagawa, Y; Shiraishi, T; Tomoike, H

    1992-09-01

    201Tl myocardial perfusion imaging during adenosine infusion was performed in consecutive 55 patients with suspected coronary artery disease. Adenosine was infused intravenously at a rate of 0.14 mg/kg/min for 6 minutes and a dose of 111 MBq of 201Tl was administered in a separate vein at the end of third minute of infusion. Myocardial SPECT imaging was begun 5 minutes and 3 hours after the end of adenosine infusion. For evaluating the presence of perfusion defects, 2 short axis images at the basal and apical levels and a vertical long axis image at the mid left ventricle were used. The regions with decreased 201Tl uptake were assessed semi-quantitatively. Adenosine infusion caused a slight reduction in systolic blood pressure and an increase in heart rate. The rate pressure products increased slightly (9314 +/- 2377 vs. 10360 +/- 2148, p < 0.001). Chest pain (24%) and headache (13%) were the frequent side effects. The second-degree atrioventricular block was developed in 11 of 55 (20%) patients. All symptoms and hemodynamic changes were well tolerated and disappeared within 1 or 2 minutes after discontinuing adenosine infusion. The sensitivity and specificity for the detection of patients with coronary artery disease were 100% (31/31) and 88% (7/8), respectively. 201Tl myocardial imaging during adenosine infusion was considered to be safe and useful for evaluating the patients with ischemic heart disease. PMID:1453559

  16. Myocardial perfusion scintigraphy: the evidence.

    PubMed

    Underwood, S R; Anagnostopoulos, C; Cerqueira, M; Ell, P J; Flint, E J; Harbinson, M; Kelion, A D; Al-Mohammad, A; Prvulovich, E M; Shaw, L J; Tweddel, A C

    2004-02-01

    This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by

  17. Brain SPECT Imaging in Complex Psychiatric Cases: An Evidence-Based, Underutilized Tool

    PubMed Central

    Amen, Daniel G; Trujillo, Manuel; Newberg, Andrew; Willeumier, Kristen; Tarzwell, Robert; Wu, Joseph C; Chaitin, Barry

    2011-01-01

    Over the past 20 years brain Single Photon Emission Computed Tomography (SPECT) imaging has developed a substantial, evidence-based foundation and is now recommended by professional societies for numerous indications relevant to psychiatric practice. Unfortunately, SPECT in clinical practice is utilized by only a handful of clinicians. This article presents a rationale for a more widespread use of SPECT in clinical practice for complex cases, and includes seven clinical applications where it may help optimize patient care. PMID:21863144

  18. 99mTc-MDP SPECT/CT for assessment of condylar hyperplasia.

    PubMed

    Derlin, Thorsten; Busch, Jasmin D; Habermann, Christian R

    2013-01-01

    We report a case of condylar hyperplasia diagnosed with 99mTc-MDP SPECT/CT. A 21-year-old woman with facial asymmetry was referred for assessment of condylar growth activity. SPECT/CT confirmed condylar hyperactivity, and simultaneous low-dose CT contributed to the diagnosis of hemimandibular hyperplasia. SPECT/CT may become a valuable tool for the diagnosis and comprehensive assessment of condylar hyperplasia, providing both functional and morphological information. PMID:23242067

  19. Design and simulation of a high-resolution stationary SPECT system for small animals

    NASA Astrophysics Data System (ADS)

    Beekman, Freek J.; Vastenhouw, Brendan

    2004-10-01

    Exciting new SPECT systems can be created by combining pinhole imaging with compact high-resolution gamma cameras. These new systems are able to solve the problem of the limited sensitivity-resolution trade-off that hampers contemporary small animal SPECT. The design presented here (U-SPECT-III) uses a set of detectors placed in a polygonal configuration and a cylindrical collimator that contains 135 pinholes arranged in nine rings. Each ring contains 15 gold pinhole apertures that focus on the centre of the cylinder. A non-overlapping projection is acquired via each pinhole. Consequently, when a mouse brain is placed in the central field-of-view, each voxel in the cerebrum can be observed via 130 to 135 different pinholes simultaneously. A method for high-resolution scintillation detection is described that eliminates the depth-of-interaction problem encountered with pinhole cameras, and is expected to provide intrinsic detector resolutions better than 150 µm. By means of simulations U-SPECT-III is compared to a simulated dual pinhole SPECT (DP-SPECT) system with a pixelated array consisting of 2.0 × 2.0 mm NaI crystals. Analytic calculations indicate that the proposed U-SPECT-III system yields an almost four times higher linear and about sixty times higher volumetric system resolution than DP-SPECT, when the systems are compared at matching system sensitivity. In addition, it should be possible to achieve a 15 up to 30 times higher sensitivity with U-SPECT-III when the systems are compared at equal resolution. Simulated images of a digital mouse-brain phantom show much more detail with U-SPECT-III than with DP-SPECT. In a resolution phantom, 0.3 mm diameter cold rods are clearly visible with U-SPECT-III, whereas with DP-SPECT the smallest visible rods are about 0.6-0.8 mm. Furthermore, with U-SPECT-III, the image deformations outside the central plane of reconstruction that hamper conventional pinhole SPECT are strongly suppressed. Simulation results indicate

  20. Prone breast tumor imaging using vertical axis-of-rotation (VAOR) SPECT systems: An initial study

    SciTech Connect

    Wang, Huili; Scarfone, C.; Greer, K.L.; Coleman, R.E.

    1996-12-31

    We propose the use of a single photon emission computed tomography (SPECT) system equipped with multiple cameras revolving around a vertical axis-of-rotation (VAOR) to image tumors in a prone-dependent breast. This innovative breast imaging approach has the advantages of a small attenuation volume between breast lesions and gamma detector as well as a minimal radius-of-rotation compared to conventional (horizontal axis-of-rotation) breast SPECT. Small attenuation volume results in improved detected counts and minimal radius-of-rotation leads to increased collimator resolution. Because of no VAOR SPECT system currently available, we conducted our experiments on a conventional SPECT system using an isolated breast phantom to investigate the proposed VAOR breast SPECT. Our experimental setup simulated a VAOR SPECT study with a prone-dependent breast in the camera`s field-of-view. The results of our experiment indicate that VAOR breast SPECT with Trionix LESR parallel hole collimator is capable of detecting a breast lesion with a diameter of 10 mm and a lesion-to-background concentration ratio of 6 to 1. The results also demonstrate that VAOR breast SPECT provides improved lesion visualization over planar scintimammography and conventional breast SPECT.

  1. Myocardial contusion in patients with blunt chest trauma as evaluated by thallium 201 myocardial scintigraphy

    SciTech Connect

    Bodin, L.; Rouby, J.J.; Viars, P.

    1988-07-01

    Fifty five patients suffering from blunt chest trauma were studied to assess the diagnosis of myocardial contusion using thallium 201 myocardial scintigraphy. Thirty-eight patients had consistent scintigraphic defects and were considered to have a myocardial contusion. All patients with scintigraphic defects had paroxysmal arrhythmias and/or ECG abnormalities. Of 38 patients, 32 had localized ST-T segment abnormalities; 29, ST-T segment abnormalities suggesting involvement of the same cardiac area as scintigraphic defects; 21, echocardiographic abnormalities. Sixteen patients had segmental hypokinesia involving the same cardiac area as the scintigraphic defects. Fifteen patients had clinical signs suggestive of myocardial contusion and scintigraphic defects. Almost 70 percent of patients with blunt chest trauma had scintigraphic defects related to areas of myocardial contusion. When thallium 201 myocardial scintigraphy directly showed myocardial lesion, two-dimensional echocardiography and standard ECG detected related functional consequences of cardiac trauma.

  2. First Robotic SPECT for Minimally Invasive Sentinel Lymph Node Mapping.

    PubMed

    Fuerst, Bernhard; Sprung, Julian; Pinto, Francisco; Frisch, Benjamin; Wendler, Thomas; Simon, Hervé; Mengus, Laurent; van den Berg, Nynke S; van der Poel, Henk G; van Leeuwen, Fijs W B; Navab, Nassir

    2016-03-01

    In this paper we present the usage of a drop-in gamma probe for intra-operative Single-Photon Emission Computed Tomography (SPECT) imaging in the scope of minimally invasive robot-assisted interventions. The probe is designed to be inserted and reside inside the abdominal cavity during the intervention. It is grasped during the procedure using a robotic laparoscopic gripper enabling full six degrees of freedom handling by the surgeon. We demonstrate the first deployment of the tracked probe for intra-operative in-patient robotic SPECT enabling augmented-reality image guidance. The hybrid mechanical- and image-based in-patient probe tracking is shown to have an accuracy of 0.2 mm. The overall system performance is evaluated and tested with a phantom for gynecological sentinel lymph node interventions and compared to ground-truth data yielding a mean reconstruction accuracy of 0.67 mm. PMID:26561283

  3. Dual-radiolabeled nanoparticle SPECT probes for bioimaging

    NASA Astrophysics Data System (ADS)

    Black, Kvar C. L.; Akers, Walter J.; Sudlow, Gail; Xu, Baogang; Laforest, Richard; Achilefu, Samuel

    2014-12-01

    A gold nanoparticle was radiolabeled with 125I and 111In and functionalized with an MMP9-cleavable peptide to form a multispectral SPECT imaging contrast agent. Peptide cleavage from the nanoprobe by MMP9 was observed in vitro, and distinct pharmacokinetic properties of the contrast agent were observed between tumors with high or low MMP9 expression.A gold nanoparticle was radiolabeled with 125I and 111In and functionalized with an MMP9-cleavable peptide to form a multispectral SPECT imaging contrast agent. Peptide cleavage from the nanoprobe by MMP9 was observed in vitro, and distinct pharmacokinetic properties of the contrast agent were observed between tumors with high or low MMP9 expression. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr05269b

  4. A novel SPECT camera for molecular imaging of the prostate

    NASA Astrophysics Data System (ADS)

    Cebula, Alan; Gilland, David; Su, Li-Ming; Wagenaar, Douglas; Bahadori, Amir

    2011-10-01

    The objective of this work is to develop an improved SPECT camera for dedicated prostate imaging. Complementing the recent advancements in agents for molecular prostate imaging, this device has the potential to assist in distinguishing benign from aggressive cancers, to improve site-specific localization of cancer, to improve accuracy of needle-guided prostate biopsy of cancer sites, and to aid in focal therapy procedures such as cryotherapy and radiation. Theoretical calculations show that the spatial resolution/detection sensitivity of the proposed SPECT camera can rival or exceed 3D PET and further signal-to-noise advantage is attained with the better energy resolution of the CZT modules. Based on photon transport simulation studies, the system has a reconstructed spatial resolution of 4.8 mm with a sensitivity of 0.0001. Reconstruction of a simulated prostate distribution demonstrates the focal imaging capability of the system.

  5. SPECT study of regional cerebral blood flow in Alzheimer disease

    SciTech Connect

    Bonte, F.J.; Ross, E.D.; Chehabi, H.H.; Devous, M.D. Sr.

    1986-07-01

    A common cause of dementia in late midlife and old age is Alzheimer disease (AD), which affects more than one in 20 individuals over the age of 65. Past studies of regional cerebral blood flow (rCBF) in patients with AD here suggested blood flow abnormalities, but findings have differed. We have studied 37 patients diagnosed as having AD with inhalation and washout of /sup 133/Xe and single-photon emission computed tomography (SPECT), obtaining evidence of abnormal rCBF patterns in 19. Flow reductions were most common in the temporoparietal regions and were occasionally found in the frontal areas. Investigators using positron-emission tomography (PET) have identified similar findings with respect to rCBF and regional oxygen, glucose, and protein metabolism. The SPECT determination of rCBF, which gives information similar to that provided by PET, may assume importance in the diagnosis of AD and in the differential diagnosis of the dementias.

  6. Infective endocarditis detection through SPECT/CT images digital processing

    NASA Astrophysics Data System (ADS)

    Moreno, Albino; Valdés, Raquel; Jiménez, Luis; Vallejo, Enrique; Hernández, Salvador; Soto, Gabriel

    2014-03-01

    Infective endocarditis (IE) is a difficult-to-diagnose pathology, since its manifestation in patients is highly variable. In this work, it was proposed a semiautomatic algorithm based on SPECT images digital processing for the detection of IE using a CT images volume as a spatial reference. The heart/lung rate was calculated using the SPECT images information. There were no statistically significant differences between the heart/lung rates values of a group of patients diagnosed with IE (2.62+/-0.47) and a group of healthy or control subjects (2.84+/-0.68). However, it is necessary to increase the study sample of both the individuals diagnosed with IE and the control group subjects, as well as to improve the images quality.

  7. Recent advances in cardiac SPECT instrumentation and system design.

    PubMed

    Smith, Mark F

    2013-08-01

    Recent advances in clinical cardiac SPECT instrumentation are reviewed from a systems perspective. New hardware technologies include pixelated scintillator and semiconductor detector elements; photodetectors such as position-sensitive photomultiplier tubes (PSPMT), avalanche photodiodes (APD) and silicon photomultipliers (SiPM); and novel cardiac collimation methods. There are new approaches for positioning detectors and controlling their motion during cardiac imaging. Software technology advances include iterative image reconstruction with modeling of Poisson statistics and depth-dependent collimator response. These new technologies enable faster acquisitions, the lowering of administered activity and radiation dose, and improved image resolution. Higher sensitivity collimators are a significant factor enabling faster acquisitions. Several clinical systems incorporating new technologies are discussed and different system designs can achieve similar performance. With detector elements such as APDs, SiPMs and semiconductors that are insensitive to magnetic fields, the potential for cardiac SPECT imagers that are MRI compatible opens up new frontiers in clinical cardiac research and patient care. PMID:23832650

  8. Bone Scintigraphy SPECT/CT Evaluation of Mandibular Condylar Hyperplasia.

    PubMed

    Yang, Zhiyun; Reed, Tameron; Longino, Becky H

    2016-03-01

    Mandibular condylar hyperplasia (CH) is a complex developmental deformity resulting in asymmetries of the hyperplastic condyle. Bone scan SPECT is a sensitive and accurate method of detecting the growth activity of this disorder. This method can be used to quantitate the radionuclide uptake differences between the left and right condyles. Uptake differences of 10% or more between the left and right condyles, with increased uptake ipsilateral to the CH, are considered to be evidence of active growing CH. Quantitative assessment of CH is important to select an appropriate treatment course. Degenerative arthropathies of the temporomandibular joints may result in altered uptake, but this is mostly associated with the side contralateral to the CH. The CT portion of SPECT/CT is useful to assess the condylar dimensions and underlying bony changes. PMID:26111714

  9. Accuracy of quantitative reconstructions in SPECT/CT imaging

    NASA Astrophysics Data System (ADS)

    Shcherbinin, S.; Celler, A.; Belhocine, T.; van der Werf, R.; Driedger, A.

    2008-09-01

    The goal of this study was to determine the quantitative accuracy of our OSEM-APDI reconstruction method based on SPECT/CT imaging for Tc-99m, In-111, I-123, and I-131 isotopes. Phantom studies were performed on a SPECT/low-dose multislice CT system (Infinia-Hawkeye-4 slice, GE Healthcare) using clinical acquisition protocols. Two radioactive sources were centrally and peripherally placed inside an anthropometric Thorax phantom filled with non-radioactive water. Corrections for attenuation, scatter, collimator blurring and collimator septal penetration were applied and their contribution to the overall accuracy of the reconstruction was evaluated. Reconstruction with the most comprehensive set of corrections resulted in activity estimation with error levels of 3-5% for all the isotopes.

  10. Dual-headed SPECT for awake animal brain imaging

    SciTech Connect

    Lee, Seung Joon; Weisenberger, A G; McKisson, J; Goddard Jr, James Samuel; Baba, Justin S; Smith, M F

    2011-01-01

    Abstract- Motion-corrected awake animal imaging is needed for normal-state investigations of models of neurological disease and brain activity. The awake animal brain SPECT/CT system, AwakeSPECT at Johns Hopkins University has in the past used a single gamma camera for imaging. Enhancements have been made by adding a pinhole collimator to the second gamma camera at the opposite side which has been previously equipped parallel hole collimator. Geometry calibration was performed using a custom built quality control phantom containing three Co-57 point sources and applied to the tomographic reconstruction code. Hot-rod phantom scans with Tc-99m were performed to test sensitivity and resolution improvements. The reconstruction results show significant resolution and sensitivity improvements.

  11. Dual-headed SPECT for awake animal brain imaging

    SciTech Connect

    S. Lee, B. Kross, D. Weisenberger, J. McKisson, J.S. Goddard, J.S. Baba, M.S. Smith

    2012-02-01

    Motion-corrected awake animal imaging is needed for normal-state investigations of models of neurological disease and brain activity. The awake animal brain SPECT/CT system, AwakeSPECT at Johns Hopkins University has in the past used a single gamma camera for imaging. Enhancements have been made by adding a pinhole collimator to the second gamma camera at the opposite side which has been previously equipped parallel hole collimator. Geometry calibration was performed using a custom built quality control phantom containing three Co-57 point sources and applied to the tomographic reconstruction code. Hot-rod phantom scans with Tc-99m were performed to test sensitivity and resolution improvements. The reconstruction results show significant resolution and sensitivity improvements.

  12. A randomized, open-label, multicenter trial for the safety and efficacy of adult mesenchymal stem cells after acute myocardial infarction.

    PubMed

    Lee, Jun-Won; Lee, Seung-Hwan; Youn, Young-Jin; Ahn, Min-Soo; Kim, Jang-Young; Yoo, Byung-Su; Yoon, Junghan; Kwon, Woocheol; Hong, In-Soo; Lee, Kyounghoon; Kwan, Jun; Park, Keum Soo; Choi, Donghoon; Jang, Yang Soo; Hong, Mun K

    2014-01-01

    Recent studies suggest that the intracoronary administration of bone marrow (BM)-derived mesenchymal stem cells (MSCs) may improve left ventricular function in patients with acute myocardial infarction (AMI). However, there is still argumentative for the safety and efficacy of MSCs in the AMI setting. We thus performed a randomized pilot study to investigate the safety and efficacy of MSCs in patients with AMI. Eighty patients with AMI after successful reperfusion therapy were randomly assigned and received an intracoronary administration of autologous BM-derived MSCs into the infarct related artery at 1 month. During follow-up period, 58 patients completed the trial. The primary endpoint was changes in left ventricular ejection fraction (LVEF) by single-photon emission computed tomography (SPECT) at 6 month. We also evaluated treatment-related adverse events. The absolute improvement in the LVEF by SPECT at 6 month was greater in the BM-derived MSCs group than in the control group (5.9% ± 8.5% vs 1.6% ± 7.0%; P=0.037). There was no treatment-related toxicity during intracoronary administration of MSCs. No significant adverse cardiovascular events occurred during follow-up. In conclusion, the intracoronary infusion of human BM-derived MSCs at 1 month is tolerable and safe with modest improvement in LVEF at 6-month follow-up by SPECT. (ClinicalTrials.gov registration number: NCT01392105). PMID:24431901

  13. A Randomized, Open-Label, Multicenter Trial for the Safety and Efficacy of Adult Mesenchymal Stem Cells after Acute Myocardial Infarction

    PubMed Central

    Lee, Jun-Won; Youn, Young-Jin; Ahn, Min-Soo; Kim, Jang-Young; Yoo, Byung-Su; Yoon, Junghan; Kwon, Woocheol; Hong, In-Soo; Lee, Kyounghoon; Kwan, Jun; Park, Keum Soo; Choi, Donghoon; Jang, Yang Soo; Hong, Mun K.

    2014-01-01

    Recent studies suggest that the intracoronary administration of bone marrow (BM)-derived mesenchymal stem cells (MSCs) may improve left ventricular function in patients with acute myocardial infarction (AMI). However, there is still argumentative for the safety and efficacy of MSCs in the AMI setting. We thus performed a randomized pilot study to investigate the safety and efficacy of MSCs in patients with AMI. Eighty patients with AMI after successful reperfusion therapy were randomly assigned and received an intracoronary administration of autologous BM-derived MSCs into the infarct related artery at 1 month. During follow-up period, 58 patients completed the trial. The primary endpoint was changes in left ventricular ejection fraction (LVEF) by single-photon emission computed tomography (SPECT) at 6 month. We also evaluated treatment-related adverse events. The absolute improvement in the LVEF by SPECT at 6 month was greater in the BM-derived MSCs group than in the control group (5.9%±8.5% vs 1.6%±7.0%; P=0.037). There was no treatment-related toxicity during intracoronary administration of MSCs. No significant adverse cardiovascular events occurred during follow-up. In conclusion, the intracoronary infusion of human BM-derived MSCs at 1 month is tolerable and safe with modest improvement in LVEF at 6-month follow-up by SPECT. (ClinicalTrials.gov registration number: NCT01392105) PMID:24431901

  14. Radiation dose to radiosensitive organs in PET/CT myocardial perfusion examination using versatile optical fibre

    NASA Astrophysics Data System (ADS)

    Salasiah, M.; Nordin, A. J.; Fathinul Fikri, A. S.; Hishar, H.; Tamchek, N.; Taiman, K.; Ahmad Bazli, A. K.; Abdul-Rashid, H. A.; Mahdiraji, G. A.; Mizanur, R.; Noor, Noramaliza M.

    2013-05-01

    Cardiac positron emission tomography (PET) provides a precise method in order to diagnose obstructive coronary artery disease (CAD), compared to single photon emission tomography (SPECT). PET is suitable for obese and patients who underwent pharmacologic stress procedures. It has the ability to evaluate multivessel coronary artery disease by recording changes in left ventricular function from rest to peak stress and quantifying myocardial perfusion (in mL/min/g of tissue). However, the radiation dose to the radiosensitive organs has become crucial issues in the Positron Emission Tomography/Computed Tomography(PET/CT) scanning procedure. The objective of this study was to estimate radiation dose to radiosensitive organs of patients who underwent PET/CT myocardial perfusion examination at Centre for Diagnostic Nuclear Imaging, Universiti Putra Malaysia in one month period using versatile optical fibres (Ge-B-doped Flat Fibre) and LiF (TLD-100 chips). All stress and rest paired myocardial perfusion PET/CT scans will be performed with the use of Rubidium-82 (82Rb). The optic fibres were loaded into plastic capsules and attached to patient's eyes, thyroid and breasts prior to the infusion of 82Rb, to accommodate the ten cases for the rest and stress PET scans. The results were compared with established thermoluminescence material, TLD-100 chips. The result shows that radiation dose given by TLD-100 and Germanium-Boron-doped Flat Fiber (Ge-B-doped Flat Fiber) for these five organs were comparable to each other where the p>0.05. For CT scans,thyroid received the highest dose compared to other organs. Meanwhile, for PET scans, breasts received the highest dose.

  15. Os trigonum syndrome on bone SPECT/CT.

    PubMed

    Huang, Jianmin; Servaes, Sabah; Zhuang, Hongming

    2014-08-01

    A 16-year-old female athlete presented with increased pain in the distal left lower extremity. A possible stress fracture or shin splint of the left tibia was first considered. A 3-phase bone scintigraphy showed a very small focus of increased activity in the posterior left foot. A diagnosis of os trigonum syndrome was made after SPECT/CT images pinpointed the activity at the left os trigonum. PMID:24686218

  16. Myocardial ischaemia in infancy and childhood

    PubMed Central

    Berry, C. L.

    1967-01-01

    Examination of 135 consecutive necropsy specimens has shown that ischaemic myocardial injury is not uncommon in infancy and childhood. The extent of the myocardial change has been assessed by a technique of staining with acid fuchsin, first described by Selye (1958). The significance of the findings is discussed. Images PMID:4163355

  17. Fast SPECT simulation including object shape dependent scatter.

    PubMed

    Beekman, F J; Viergever, M A

    1995-01-01

    A fast simulator of SPECT projection data taking into account attenuation, distance dependent detector response, and scatter has been developed, based on an analytical point spread function model. The parameters of the scatter response are obtained from a single line source measurement with a triangular phantom. The simulator is able to include effects of object curvature on the scatter response to a high accuracy. The simulator has been evaluated for homogeneous media by measurements of (99m)Tc point sources placed at different locations in a water-filled cylinder at energy windows of 15% and 20%. The asymmetrical shapes of measured projections of point sources are In excellent agreement with simulations for both energy windows. Scatter-to-primary ratio (SPR) calculations of point sources at different positions in a cylindrical phantom differ not more than a few percent from measurements. The simulator uses just a few megabytes of memory for storing the tables representing the forward model; furthermore, simulation of 60 SPECT projections from a three-dimensional digital brain phantom with 6-mm cubic voxels takes only ten minutes on a standard workstation. Therefore, the simulator could serve as a projector in iterative true 3-D SPECT reconstruction. PMID:18215831

  18. Fast SPECT simulation including object shape dependent scatter

    SciTech Connect

    Beekman, F.J.; Viergever, M.A.

    1995-06-01

    A fast simulator of SPECT projection data taking into account attenuation, distance dependent detector response, and scatter has been developed, based on an analytical point spread function model. The parameters of the scatter response are obtained from a single line source measurement with a triangular phantom. The simulator is able to include effects of object curvature on the scatter responses to a high accuracy. The simulator has been evaluated for homogeneous media by measurements of {sup 99m}Tc point sources placed at different locations in a water-filled cylinder at energy windows of 15% and 20%. The asymmetrical shapes of measured projections of point sources are in excellent agreement with simulations for both energy windows. Scatter-to-primary ratio (SPR) calculations of point sources at different positions in a cylindrical phantom differ not more than a few percent from measurements. The simulator uses just a few megabytes of memory for storing the tables representing the forward model; furthermore, simulation of 60 SPECT projections from a three-dimensional digital brain phantom with 6-mm cubic voxels takes only ten minutes on a standard workstation. Therefore, the simulator could serve as a projector in iterative true 3-D SPECT reconstruction.

  19. SPECT-PET in Epilepsy and Clinical Approach in Evaluation.

    PubMed

    Ergün, Eser Lay; Saygi, Serap; Yalnizoglu, Dilek; Oguz, Kader Karli; Erbas, Belkis

    2016-07-01

    In epilepsy, a detailed history, blood chemistry, routine electroencephalography, and brain MRI are important for the diagnosis of seizure type or epilepsy syndrome for the decision of appropriate drug treatment. Although antiepileptic drugs are mostly successful for controlling epileptic seizures, 20%-30% patients are resistant to medical treatment and continue to have seizures. In this intractable patient group, surgical resection is the primarily preferred treatment option. This particular group of patients should be referred to the epilepsy center for detailed investigation and further treatment. When the results of electroencephalography, MRI, and clinical status are discordant or there is no structural lesion on MRI, ictal-periictal SPECT, and interictal PET play key roles for lateralization or localization of epileptic region and guidance for the subsequent subdural electrode placement in intractable epilepsy. SPECT and PET show the functional status of the brain. SPECT and PET play important roles in the evaluation of epilepsy sydromes in childhood by showing abnormal brain regions. Most of the experience has been gained with (18)FDG-PET, in this respect. (11)C-flumazenil-PET usually deliniates the seizure focus more smaller than (18)FDG-PET and is sensitive in identifying medial temporal sclerosis. (11)C-alpha-methyl-l-tryptophan is helpful in the differentiation of epileptogenic and nonepileptogenic regions in children especially in tuberous sclerosis and multifocal cortical dysplasia for the evaluation of surgery. Finally, when there is concordance among these detailed investigations, resective surgery or palliative procedures can be discussed individually. PMID:27237440

  20. Compact CT/SPECT Small-Animal Imaging System

    PubMed Central

    Kastis, George A.; Furenlid, Lars R.; Wilson, Donald W.; Peterson, Todd E.; Barber, H. Bradford; Barrett, Harrison H.

    2015-01-01

    We have developed a dual-modality CT/SPECT imaging system for small-animal imaging applications. The X-ray system comprises a commercially available micro-focus X-ray tube and a CCD-based X-ray camera. X-ray transmission measurements are performed based on cone-beam geometry. Individual projections are acquired by rotating the animal about a vertical axis in front of the CCD detector. A high-resolution CT image is obtained after reconstruction using an ordered subsets-expectation maximization (OS-EM) reconstruction algorithm. The SPECT system utilizes a compact semiconductor camera module previously developed in our group. The module is mounted perpendicular to the X-ray tube/CCD combination. It consists of a 64×64 pixellated CdZnTe detector and a parallel-hole tungsten collimator. The field of view is 1 square inch. Planar projections for SPECT reconstruction are obtained by rotating the animal in front of the detector. Gamma-ray and X-ray images are presented of phantoms and mice. Procedures for merging the anatomical and functional images are discussed. PMID:26538684

  1. SPECT-CT system for small animal imaging

    SciTech Connect

    Andrew Weisenberger; Randolph Wojcik; E.L. Bradley; Paul Brewer; Stanislaw Majewski; Jianguo Qian; Amoreena Ranck; Arunava Saha; Mark Smith; Robert Welsh

    2003-02-01

    The Detector Group at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) and the Biology, Physics, and Applied Sciences Departments at the College of William and Mary are collaborating on the development of a miniature dual modality SPECT-CT system for mouse imaging. The detector heads of the SPECT sub-system are designed to be capable of imaging the gamma- and X-ray emissions (28-35 keV) of the radioactive isotope iodine-125 (I-125). Two different sets of I-125 imaging detectors are configured on a gantry that has an open-barrel type design. One set of detector heads is based on the 1-in square Hamamatsu R5900-M64 position sensitive photomultiplier tube coupled to crystal scintillator arrays. The other detector heads configured on the gantry are two 5-in diameter Hamamatsu R3292-based compact gamma cameras. The X-ray radiographic projections are obtained using a LIXI Inc. model LF-85-503-OS X-ray imaging system that has an active area of 5.5 cm in diameter. The open-barrel shaped gantry facilitates the positioning of various mini gamma-ray imaging detectors and the X-ray system. The data acquisition and gantry control is interfaced through a Macintosh G3 workstation. Preliminary SPECT reconstruction results using the R5900 based detector are presented.

  2. SPECT-CT System for Small Animal Imaging

    SciTech Connect

    A.G. Weisenberger; R. Wojcik; E.L. Bradley; P. Brewer; S. Majewski; J. Qian; A. Ranck; M.S. Saha; K. Smith; M.F. Smith; R.E. Welsh

    2001-11-01

    The Detector Group at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) and the Biology, Physics and Applied Sciences Departments at the College of William and Mary are collaborating on the development of a miniature dual modality SPECT-CT system for mouse imaging. The detector heads of the SPECT sub-system are capable of imaging the gamma- and x-ray emissions (28-35 keV) of the radioactive isotope iodine-125 (I-125). Two different sets of I-125 imaging detectors are configured on a gantry which has an open-barrel type design. One set of detector heads is based on the 1 inch square Hamamatsu R5900-M64 position sensitive photomultiplier tube coupled to crystal scintillator arrays. The other detector heads configured on the gantry are two 5-inch diameter Hamamatsu R3292-based compact gamma cameras. The x-ray radiographic projections will be obtained using a LIXI Inc. model LF-85-503-OS x-ray imaging system that has an active area of 5.5 cm in diameter. The open-barrel shaped gantry facilitates the positioning of various mini gamma-ray imaging detectors and the x-ray system. The data acquisition and gantry control is interfaced through a Macintosh G3 workstation. SPECT reconstruction results using the R5900 based detector are presented.

  3. Physiological imaging with PET and SPECT in Dementia

    SciTech Connect

    Jagust, W.J. . Dept. of Neurology Lawrence Berkeley Lab., CA )

    1989-10-01

    Dementia is a medical problem of increasingly obvious importance. The most common cause of dementia, Alzheimer's disease (AD) accounts for at least 50% of all cases of dementia, with multi-infarct dementia the next most common cause of the syndrome. While the accuracy of diagnosis of AD may range from 80 to 90%, there is currently no laboratory test to confirm the diagnosis. Functional imaging techniques such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) offer diagnostic advantages since brain function is unequivocally disturbed in all dementing illnesses. Both PET and SPECT have been utilized in the study of dementia. While both techniques rely on principles of emission tomography to produce three dimensional maps of injected radiotracers, the differences between positron and single photon emission have important consequences for the practical applications of the two procedures. This briefly reviews the technical differences between PET and SPECT, and discusses how both techniques have been used in our laboratory to elucidate the pathophysiology of dementia. 32 refs., 2 figs.

  4. Risk stratification after myocardial infarction. Clinical overview

    SciTech Connect

    O'Rourke, R.A. )

    1991-09-01

    Many patients with an acute myocardial infarction can be stratified into subgroups that are at high risk for morbidity and mortality on the basis of clinical characteristics that indicate recurrent myocardial ischemia, persistent left ventricular dysfunction, and/or recurrent cardiac arrhythmias. In patients with uncomplicated myocardial infarction the assessment of symptoms, physical findings, and ECG changes during predischarge exercise testing often identifies patients at increased risk for further cardiac events. Because of the suboptimum sensitivity and specificity of the exercise ECG for detecting myocardial ischemia, myocardial perfusion imaging with 201Tl and/or assessment of global and segmental ventricular function by two-dimensional echocardiography or radionuclide cineangiography during or immediately after exercise are often added to the predischarge risk stratification.

  5. [Ischemic myocardial metabolism and antianginal drugs].

    PubMed

    Ichihara, K

    1986-12-01

    The effect of several kinds of antianginal drugs: nitrates, coronary vasodilators, beta-adrenergic blocking agents and calcium entry blocking agents on the myocardial metabolism and myocardial acidosis during ischemia was studied in the dog heart in vivo. Ischemia was induced by ligating the left anterior descending coronary artery. Ischemia accelerated anaerobic metabolism in the myocardium, in which glycogen breakdown, accumulation of glycolytic intermediates, loss of high energy phosphate and tissue acidosis occurred. Nitroglycerin, beta-adrenergic blocking agents such as propranolol, and some calcium entry blocking agents such as diltiazem and flunarizine prevented the myocardial metabolism from shifting to an anaerobic metabolism in spite of ischemia. However, coronary vasodilators and the dihydropyridine type of calcium entry blocking agents were not capable of reducing changes in the myocardial metabolism and myocardial acidosis during ischemia. The author makes a point in the present review that all the drugs which dilate coronary artery are not always effective on the ischemic myocardium. PMID:3549484

  6. [Fibrinolysis in acute myocardial infarct].

    PubMed

    Bleifeld, W

    1987-10-24

    Fibrinolysis has opened up a new avenue in the treatment of acute myocardial infarction (AMI). In principle, the rate of reperfusion depends on the type of compound used, the mode of administration and the time between onset of symptoms and the beginning of treatment. With intracoronary streptokinase the reperfusion rate is of the order of 85%. Intravenous urokinase administered as a bolus results in a reopening rate of 50-60%; a similar rate of reperfusion is achieved with rt-PA as infusion, while i.v. streptokinase produces about 50% reopened coronary vessels. The final infarct size is decreased in 70% of patients if fibrinolysis is initiated within 2.5 hours after the onset of symptoms and followed by reopening of the occluded vessel. This results in a lowering of in-hospital mortality, which in various studies is of the order of 45-60%.- Bearing in mind the contraindications, fibrinolysis should be initiated within 3 hours. Hemodynamic improvement by a decrease of infarct size may also be achieved beyond 3 hours in large anterior myocardial infarctions and in posterior infarctions with cardiogenic shock. Early initiation of thrombolysis is of major importance in improving left ventricular function and lowering mortality following acute myocardial infarction. Therefore, prehospital thrombolytic therapy should be considered. - In the postinfarction phase coronary angiography is indicated in patients with angina at rest, stable angina of ECG signs of ischemia. In this situation transfer to a specialized cardiology division for possible percutaneous transluminal angioplasty is indicated. - Reocclusion after successful thrombolysis occurs in 20-30%, and it is therefore important to avoid reinfarction to improve the long term prognosis after AMI.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3321420

  7. Myocardial protection with mild hypothermia.

    PubMed

    Tissier, Renaud; Ghaleh, Bijan; Cohen, Michael V; Downey, James M; Berdeaux, Alain

    2012-05-01

    Mild hypothermia, 32-35° C, is very potent at reducing myocardial infarct size in rabbits, dogs, sheep, pigs, and rats. The benefit is directly related to reduction in normothermic ischaemic time, supporting the relevance of early and rapid cooling. The cardioprotective effect of mild hypothermia is not limited to its recognized reduction of infarct size, but also results in conservation of post-ischaemic contractile function, prevention of no-reflow or microvascular obstruction, and ultimately attenuation of left ventricular remodelling. The mechanism of the anti-infarct effect does not appear to be related to diminished energy utilization and metabolic preservation, but rather to survival signalling that involves either the extracellular signal-regulated kinases and/or the Akt/phosphoinositide 3-kinase/mammalian target of rapamycin pathways. Initial clinical trials of hypothermia in patients with ST-segment elevation myocardial infarction were disappointing, probably because cooling was too slow to shorten normothermic ischaemic time appreciably. New approaches to more rapid cooling have recently been described and may soon be available for clinical use. Alternatively, it may be possible to pharmacologically mimic the protection provided by cooling soon after the onset of ischaemia with an activator of mild hypothermia signalling, e.g. extracellular signal-regulated kinase activator, that could be given by emergency medical personnel. Finally, the protection afforded by cooling can be added to that of pre- and post-conditioning because their mechanisms differ. Thus, myocardial salvage might be greatly increased by rapidly cooling patients as soon as possible and then giving a pharmacological post-conditioning agent immediately prior to reperfusion. PMID:22131353

  8. Solar activity and myocardial infarction.

    PubMed

    Szczeklik, E; Mergentaler, J; Kotlarek-Haus, S; Kuliszkiewicz-Janus, M; Kucharczyk, J; Janus, W

    1983-01-01

    The correlation between the incidence of myocardial infarction, sudden cardiac death, the solar activity and geomagnetism in the period 1969-1976 was studied, basing on Wrocław hospitals material registered according to WHO standards; sudden death was assumed when a person died within 24 hours after the onset of the disease. The highest number of infarctions and sudden deaths was detected for 1975, which coincided with the lowest solar activity, and the lowest one for the years 1969-1970 coinciding with the highest solar activity. Such an inverse, statistically significant correlation was not found to exist between the studied biological phenomena and geomagnetism. PMID:6851574

  9. [Cardiac rehabilitation after myocardial infarction].

    PubMed

    Ghannem, M; Ghannem, L; Ghannem, L

    2015-12-01

    Although the proofs of the benefits of cardiac rehabilitation accumulate, many patients are not sent to rehabilitation units, especially younger and very elderly patients. As the length of stay in acute care units decreases, rehabilitation offers more time to fully assess the patients' conditions and needs. Meta-analyses of randomised trials suggest that mortality can be improved by as much as 20-30%. In addition, rehabilitation helps managing risk factors, including hyperlipidemia, diabetes, smoking and sedentary behaviours. Physical training also helps improving exercise capacity. Because of all of these effects, cardiac rehabilitation for post-myocardial infarction patients has been given a class IA recommendation in current guidelines. PMID:26548984

  10. Direction-dependent localization errors in SPECT images

    SciTech Connect

    Roper, Justin; Bowsher, James; Yin Fangfang

    2010-09-15

    Purpose: Single photon emission computed tomography (SPECT) is being investigated for imaging inside radiation therapy treatment rooms to localize biological targets. Here, computer simulations were used to analyze locational and directional dependencies in localization errors and to assess the effects of spatial resolution modeling and observer normalization on localization performance. Methods: SPECT images of the XCAT phantom, containing 12 hot tumors, were reconstructed with detector response function compensation (DRC) and without DRC (nDRC). Numerical observers were forced to select the most suspicious tumor location, using normalized cross correlation (NXC) or un-normalized cross correlation (XC), from 3 cm diameter search volumes that each contained only one tumor. For each tumor site, localization was optimized as a function of the iteration number and postreconstruction smoothing. Localization error, the distance between true and estimated tumor positions, was calculated across the ensembles of 80 images. Direction-dependent localization bias and precision were estimated from the image ensemble. Results: For the six superficial tumors in close proximity to the detector trajectory, mean localization errors were <2 mm and were lowest or comparable using DRC-NXC, though differences from DRC-XC and nDRC-NXC were not statistically significant. DRC-NXC did provide statistically significantly better localization than nDRC-XC for five of these six tumors. At the other six sites where attenuation was more severe and the distance was generally greater between the tumor and detector, DRC typically did not show better localization than nDRC. Observer normalization improved the localization substantially for a tumor near the hotter heart. Localization errors were anisotropic and dependent on tumor location relative to the detector trajectory. Conclusions: This computer-simulation study compared localization performance for normalized and un-normalized numerical

  11. Prognostic Value of Major Cardiac Event Risk Score Estimated With Gated Myocardial Perfusion Imaging in Japanese Patients With Coronary Artery Disease.

    PubMed

    Yoda, Shunichi; Nakanishi, Kanae; Tano, Ayako; Hori, Yusuke; Hayase, Misa; Mineki, Takashi; Suzuki, Yasuyuki; Matsumoto, Naoya; Hirayama, Atsushi

    2016-07-27

    We published a cardiac event risk score (CERS) predicting the risk of major cardiac events (MCEs) within 3 years. The purpose of this study was to verify the prognostic value of the CERS before and after treatment in Japanese patients with coronary artery disease.We retrospectively investigated 612 patients who underwent rest (201)Tl and stress (99m)Tc-tetrofosmin myocardial perfusion single photon emission computed tomography (SPECT) between October 2004 and March 2013 and who had a significant stenosis with ≥ 75% narrowing of the arterial diameter detected by coronary angiography performed after confirmation of ≥ 5% ischemia with the SPECT. The patients underwent treatment including revascularization and medication, and thereafter, were re-evaluated with SPECT during a chronic phase and followed-up to confirm prognosis for ≥ 1 year. The endpoint was the onset of MCEs during the follow-up.During the follow-up (36.7 ± 14.5 months), 50 patients (8.7%) experienced MCEs comprising cardiac death (n = 16), non-fatal myocardial infarction (n = 4), and unstable angina pectoris (n = 30). The multivariate Cox proportional hazards regression model analysis for the actual occurrence of MCEs showed the summed difference score % and MCE risks estimated with the CERS after treatment to be significant independent variables. Ischemic reduction after treatment contributed significantly to a decrease in the MCE risks. The MCE risks estimated with the CERS after treatment were generally consistent with the incidence of the MCEs actually observed.The CERS after treatment is a valuable formula for predicting prognosis in Japanese patients with coronary artery disease. PMID:27357436

  12. A parallel Monte Carlo code for planar and SPECT imaging: implementation, verification and applications in 131I SPECT

    PubMed Central

    Dewaraja, Yuni K.; Ljungberg, Michael; Majumdar, Amitava; Bose, Abhijit; Koral, Kenneth F.

    2009-01-01

    This paper reports the implementation of the SIMIND Monte Carlo code on an IBM SP2 distributed memory parallel computer. Basic aspects of running Monte Carlo particle transport calculations on parallel architectures are described. Our parallelization is based on equally partitioning photons among the processors and uses the Message Passing Interface (MPI) library for interprocessor communication and the Scalable Parallel Random Number Generator (SPRNG) to generate uncorrelated random number streams. These parallelization techniques are also applicable to other distributed memory architectures. A linear increase in computing speed with the number of processors is demonstrated for up to 32 processors. This speed-up is especially significant in Single Photon Emission Computed Tomography (SPECT) simulations involving higher energy photon emitters, where explicit modeling of the phantom and collimator is required. For 131I, the accuracy of the parallel code is demonstrated by comparing simulated and experimental SPECT images from a heart/thorax phantom. Clinically realistic SPECT simulations using the voxel-man phantom are carried out to assess scatter and attenuation correction. PMID:11809318

  13. Mechanics of the left ventricular myocardial interstitium: effects of acute and chronic myocardial edema.

    PubMed

    Desai, Ketaki V; Laine, Glen A; Stewart, Randolph H; Cox, Charles S; Quick, Christopher M; Allen, Steven J; Fischer, Uwe M

    2008-06-01

    Myocardial interstitial edema forms as a result of several disease states and clinical interventions. Acute myocardial interstitial edema is associated with compromised systolic and diastolic cardiac function and increased stiffness of the left ventricular chamber. Formation of chronic myocardial interstitial edema results in deposition of interstitial collagen, which causes interstitial fibrosis. To assess the effect of myocardial interstitial edema on the mechanical properties of the left ventricle and the myocardial interstitium, we induced acute and chronic interstitial edema in dogs. Acute myocardial edema was generated by coronary sinus pressure elevation, while chronic myocardial edema was generated by chronic pulmonary artery banding. The pressure-volume relationships of the left ventricular myocardial interstitium and left ventricular chamber for control animals were compared with acutely and chronically edematous animals. Collagen content of nonedematous and chronically edematous animals was also compared. Generating acute myocardial interstitial edema resulted in decreased left ventricular chamber compliance compared with nonedematous animals. With chronic edema, the primary form of collagen changed from type I to III. Left ventricular chamber compliance in animals made chronically edematous was significantly higher than nonedematous animals. The change in primary collagen type secondary to chronic left ventricular myocardial interstitial edema provides direct evidence for structural remodeling. The resulting functional adaptation allows the chronically edematous heart to maintain left ventricular chamber compliance when challenged with acute edema, thus preserving cardiac function over a wide range of interstitial fluid pressures. PMID:18375722

  14. Cell therapy for myocardial infarction.

    PubMed

    Kwon, Yoo-Wook; Yang, Han-Mo; Cho, Hyun-Jai

    2010-05-01

    Ischemic heart disease, particularly acute myocardial infarction (MI), is the worldwide health care problem and the leading cause of morbidity and mortality. The fundamental treatment of MI remains a major unmet medical need. Although recent tremendous advances have been made in the treatment for acute MI such as percutaneous coronary intervention (PCI) and medical and surgical therapies, myocardial cell loss after ischemia and subsequent, adverse cardiac remodeling and heart failure are demanding for new therapeutic strategy. Since the first experimental studies of adult stem cell therapy into the ischemic heart were performed in the early 1990s, the identification and potential application of stem and/or progenitor cells has triggered attempts to regenerate damaged heart tissue and cell-based therapy is a promising option for treatment of MI. In this review, we would like to discuss the pathogenesis of acute MI, current standard treatments and their limitation, clinical results of recent stem or progenitor cell therapy which have shown a favorable safety profile with modest improvement in cardiac function, and putative mechanisms of benefits. PMID:24855535

  15. Circadian influences on myocardial infarction.

    PubMed

    Virag, Jitka A I; Lust, Robert M

    2014-01-01

    Components of circadian rhythm maintenance, or "clock genes," are endogenous entrainable oscillations of about 24 h that regulate biological processes and are found in the suprachaismatic nucleus (SCN) and many peripheral tissues, including the heart. They are influenced by external cues, or Zeitgebers, such as light and heat, and can influence such diverse phenomena as cytokine expression immune cells, metabolic activity of cardiac myocytes, and vasodilator regulation by vascular endothelial cells. While it is known that the central master clock in the SCN synchronizes peripheral physiologic rhythms, the mechanisms by which the information is transmitted are complex and may include hormonal, metabolic, and neuronal inputs. Whether circadian patterns are causally related to the observed periodicity of events, or whether they are simply epi-phenomena is not well established, but a few studies suggest that the circadian effects likely are real in their impact on myocardial infarct incidence. Cycle disturbances may be harbingers of predisposition and subsequent response to acute and chronic cardiac injury, and identifying the complex interactions of circadian rhythms and myocardial infarction may provide insights into possible preventative and therapeutic strategies for susceptible populations. PMID:25400588

  16. Circadian influences on myocardial infarction

    PubMed Central

    Virag, Jitka A. I.; Lust, Robert M.

    2014-01-01

    Components of circadian rhythm maintenance, or “clock genes,” are endogenous entrainable oscillations of about 24 h that regulate biological processes and are found in the suprachaismatic nucleus (SCN) and many peripheral tissues, including the heart. They are influenced by external cues, or Zeitgebers, such as light and heat, and can influence such diverse phenomena as cytokine expression immune cells, metabolic activity of cardiac myocytes, and vasodilator regulation by vascular endothelial cells. While it is known that the central master clock in the SCN synchronizes peripheral physiologic rhythms, the mechanisms by which the information is transmitted are complex and may include hormonal, metabolic, and neuronal inputs. Whether circadian patterns are causally related to the observed periodicity of events, or whether they are simply epi-phenomena is not well established, but a few studies suggest that the circadian effects likely are real in their impact on myocardial infarct incidence. Cycle disturbances may be harbingers of predisposition and subsequent response to acute and chronic cardiac injury, and identifying the complex interactions of circadian rhythms and myocardial infarction may provide insights into possible preventative and therapeutic strategies for susceptible populations. PMID:25400588

  17. [Acute myocardial infarction during sport].

    PubMed

    Fujiwara, M; Asakuma, S; Nakamura, K; Nakamura, T; Yasutomi, N; Iwasaki, T

    1995-10-01

    Thirty patients with acute myocardial infarction which occurred during sport were investigated to identify the type of sport, prodromata, situations at the onset of disease, habit of exercise, preceding medical evaluation, coronary risk factors, and coronary angiographic findings. Infarction occurred during golf in 12 patients, bowling in 4, gateball in 4, jogging or running in 5, baseball in 2, and tennis or table tennis in 3. The majority of the patients were playing ball games. Twenty-seven patients were men (90%) and 3 were women (10%). All patients had played the same kind of sport for several years. Twenty-four patients had one or more coronary risk factors, and especially 18 patients smoked cigarettes. Nine patients had experienced anterior chest pain but only two patients had received medical evaluation. Coronary angiography was performed in 25 patients (83.3%), revealing single-vessel disease in 14, two-vessel disease in 6, three-vessel disease in 4, and disease of all left main coronary trunks in 1. The acute episode of infarction occurred mainly in spring or fall. Many patients with acute myocardial infarction occurring during sport participate in sports of low or moderate dynamic and low static exercises which are generally regarded safe. Many patients had enjoyed their sports regularly for a long time. Though many patients had coronary risk factors, only a few had received a medical check before their heart attack. PMID:7500263

  18. Clinical value and severity of myocardial perfusion defects in asymptomatic diabetic patients with negative or weakly positive exercise treadmill test

    PubMed Central

    Zakavi, Seyed Rasoul; Taherpour, Mehdi; Moossavi, Zohreh; Sadeghi, Ramin; Kakhki, Vahidreza Dabbagh; Rokni, Haleh

    2013-01-01

    Objective: Although coronary artery disease (CAD) is the leading cause of death in type 2 diabetic patients, it is frequently asymptomatic. Myocardial perfusion imaging (MPI) is reported to show ischemia in a significant number of asymptomatic diabetic patients. We studied the prevalence and severity of myocardial perfusion defects in asymptomatic diabetic patients and its clinical impact. Methods and patients: One hundred thirty consecutive asymptomatic patients, aged 35-65 years with type 2 diabetes mellitus and with no history of CAD and no cardiac symptoms were recruited in the study. Echocardiography, electrocardiography (ECG), routine laboratory tests and exercise treadmill test (ETT) were performed and patients with weakly positive or negative ETT underwent Dipyridamole MPI. Patients with positive ETT were referred to coronary angiography. Patients were followed for at least 17 months (mean 21.7 months) and any cardiac event was recorded. Results: We studied 81 female and 49 male patients with mean age of 51.8 years. Negative, weakly positive and positive ETT result was noted in 74.3%, 15% and 10.7% respectively. 75% of patients with positive ETT had coronary artery disease in angiography. Gated myocardial perfusion SPECT was done in 106 patients. MPI showed reversible defect in 26.9% of the patients with a mean summed stress score of 3.3±1.8. Follow up completed in 112 patients and only one patient with abnormal MPI underwent coronary angiography followed by PTCA. No cardiac death, MI, UA or hospital admission occurred among our patients during follow up (17-26 months). Mean stress end diastolic volume (EDV) was significantly higher in patients with reversible defect compared to patients without reversible defect based on MPI findings (62.0±31.6 Vs 48.5±18.4 ml, P=0.04). Blood glucose and HbA1c were significantly higher in patients with ischemia compared to patients without ischemia (P<0.05). Meanwhile the ratio of TG to HDL was 6.06±3.2 in ischemic

  19. Distinction between hemangioma of the liver and hepatocellular carcinoma: value of labeled RBC-SPECT scanning

    SciTech Connect

    Kudo, M.; Ikekubo, K.; Yamamoto, K.; Ibuki, Y.; Hino, M.; Tomita, S.; Komori, H.; Orino, A.; Todo, A.

    1989-05-01

    The role of adding single-photon emission CT (SPECT) to /sup 99m/Tc-labeled RBC imaging of the liver was evaluated by specifically focusing on the differentiation between hepatic hemangioma and hepatocellular carcinoma. Planar RBC imaging followed by blood-pool SPECT scanning was performed in 77 patients with a total of 108 hemangiomas and in 29 patients with a total of 46 hepatocellular carcinomas. All lesions were smaller than 5 cm in diameter. Thirty-six (33%) of 108 hemangiomas were detected by planar delayed RBC imaging, whereas 63 (58%) were detected by the delayed RBC-SPECT scan. The smallest hemangioma shown by delayed RBC-SPECT scanning was 1.4 cm in diameter, compared with 1.7 cm by planar RBC scanning. When confined to nodules larger than 1.4 cm in diameter, 42% of hemangiomas (36/85) were detected by planar delayed RBC imaging, whereas 74% (63/85) were detected by delayed RBC-SPECT. Increase in sensitivity was noted in nodules 2.1-4.0 cm in diameter. No hepatocellular carcinomas were shown by delayed RBC planar or SPECT scans. We concluded that with the addition of SPECT, the sensitivity of delayed RBC scans in the detection of small hemangiomas is considerably improved. Delayed RBC-SPECT scanning can be used to distinguish hemangioma from hepatocellular carcinoma.

  20. Evaluation of the Effect of Attenuation Correction by External CT in a Semiconductor SPECT.

    PubMed

    Uchibe, Taku; Miyai, Masahiro; Yata, Nobuhiro; Haramoto, Masuo; Yamamoto, Yasushi; Nakamura, Megumi; Kitagaki, Hajime; Takahashi, Yasuyuki

    2016-07-01

    The discovery of NM530c with a cadmium-zinc-telluride detector (CdZnTe-SPECT) is superior to the conventional Anger-type SPECT with a sodium-iodide detector (NaI-SPECT) in terms of sensitivity and spatial resolution. However, in the clinical example, even in CdZnTe-SPECT, a count decrease in myocardium due to the attenuation of the gamma ray is an issue. This study was conducted to evaluate the effect of computed tomography attenuation correction (CTAC) in CdZnTe-SPECT with the help of external CT. We evaluated the revision effect of uniformity, influence by the difference in attenuation distance, contrast ratio, an uptake rate using the heart phantom. As a result of the phantom studies, a good revision effect was obtained. In the clinical study, there was a statistical significant difference between the contrast ratio before and after CTAC in the inferior wall. In addition, the contrast ratio before and after CTAC in CdZnTe-SPECT image was equal to those of NaI-SPECT image. It was suggested that CTAC using external CT in CdZnTe-SPECT was clinically useful for inferior wall. PMID:27440705

  1. SPECT assay of radiolabeled monoclonal antibodies. Final performance report, March 1992--November 1995

    SciTech Connect

    Jaszczak, R.J.

    1995-12-01

    Research is described in the following areas: development and evaluation quantitatively of reconstruction algorithms with improved compensations for attenuation, scatter, and geometric collimator response; evaluation of single photon emission computed tomography (SPECT) quantification of iodine 123 and astatine 211; and the development and evaluation of SPECT pinhole imaging for low and medium energy photons.

  2. SPECT-OPT multimodal imaging enables accurate evaluation of radiotracers for β-cell mass assessments

    PubMed Central

    Eter, Wael A.; Parween, Saba; Joosten, Lieke; Frielink, Cathelijne; Eriksson, Maria; Brom, Maarten; Ahlgren, Ulf; Gotthardt, Martin

    2016-01-01

    Single Photon Emission Computed Tomography (SPECT) has become a promising experimental approach to monitor changes in β-cell mass (BCM) during diabetes progression. SPECT imaging of pancreatic islets is most commonly cross-validated by stereological analysis of histological pancreatic sections after insulin staining. Typically, stereological methods do not accurately determine the total β-cell volume, which is inconvenient when correlating total pancreatic tracer uptake with BCM. Alternative methods are therefore warranted to cross-validate β-cell imaging using radiotracers. In this study, we introduce multimodal SPECT - optical projection tomography (OPT) imaging as an accurate approach to cross-validate radionuclide-based imaging of β-cells. Uptake of a promising radiotracer for β-cell imaging by SPECT, 111In-exendin-3, was measured by ex vivo-SPECT and cross evaluated by 3D quantitative OPT imaging as well as with histology within healthy and alloxan-treated Brown Norway rat pancreata. SPECT signal was in excellent linear correlation with OPT data as compared to histology. While histological determination of islet spatial distribution was challenging, SPECT and OPT revealed similar distribution patterns of 111In-exendin-3 and insulin positive β-cell volumes between different pancreatic lobes, both visually and quantitatively. We propose ex vivo SPECT-OPT multimodal imaging as a highly accurate strategy for validating the performance of β-cell radiotracers. PMID:27080529

  3. SPECT-OPT multimodal imaging enables accurate evaluation of radiotracers for β-cell mass assessments.

    PubMed

    Eter, Wael A; Parween, Saba; Joosten, Lieke; Frielink, Cathelijne; Eriksson, Maria; Brom, Maarten; Ahlgren, Ulf; Gotthardt, Martin

    2016-01-01

    Single Photon Emission Computed Tomography (SPECT) has become a promising experimental approach to monitor changes in β-cell mass (BCM) during diabetes progression. SPECT imaging of pancreatic islets is most commonly cross-validated by stereological analysis of histological pancreatic sections after insulin staining. Typically, stereological methods do not accurately determine the total β-cell volume, which is inconvenient when correlating total pancreatic tracer uptake with BCM. Alternative methods are therefore warranted to cross-validate β-cell imaging using radiotracers. In this study, we introduce multimodal SPECT - optical projection tomography (OPT) imaging as an accurate approach to cross-validate radionuclide-based imaging of β-cells. Uptake of a promising radiotracer for β-cell imaging by SPECT, (111)In-exendin-3, was measured by ex vivo-SPECT and cross evaluated by 3D quantitative OPT imaging as well as with histology within healthy and alloxan-treated Brown Norway rat pancreata. SPECT signal was in excellent linear correlation with OPT data as compared to histology. While histological determination of islet spatial distribution was challenging, SPECT and OPT revealed similar distribution patterns of (111)In-exendin-3 and insulin positive β-cell volumes between different pancreatic lobes, both visually and quantitatively. We propose ex vivo SPECT-OPT multimodal imaging as a highly accurate strategy for validating the performance of β-cell radiotracers. PMID:27080529

  4. Use of thallium 201 myocardial imaging to exclude myocardial infarction after dissection in congenital coarctation of the aorta

    SciTech Connect

    Halon, D.A.; Weiss, A.T.; Tzivoni, D.; Atlan, H.; Gotsman, M.S.

    1981-10-01

    The use of a mobile gamma camera with thallium 201 myocardial imaging is described to exclude myocardial infarction in a patient admitted to the coronary care unit in shock and with clinical, enzyme, and ECG changes consistent with infarction. The patient suffered from acute aortic dissection associated with congenital coarctation of the aorta. The myocardial scan excluded transmural myocardial injury.

  5. Altered myocardial perfusion in patients with angina pectoris or silent ischemia during exercise as assessed by quantitative thallium-201 single-photon emission computed tomography

    SciTech Connect

    Mahmarian, J.J.; Pratt, C.M.; Cocanougher, M.K.; Verani, M.S. )

    1990-10-01

    The extent of abnormally perfused myocardium was compared in patients with and without chest pain during treadmill exercise from a large, relatively low-risk consecutive patient population (n = 356) referred for quantitative thallium-201 single-photon emission computed tomography (SPECT). All patients had concurrent coronary angiography. Patients were excluded if they had prior coronary angioplasty or bypass surgery. Tomographic images were assessed visually and from computer-generated polar maps. Chest pain during exercise was as frequent in patients with normal coronary arteries (12%) as in those with significant (greater than 50% stenosis) coronary artery disease (CAD) (14%). In the 219 patients with significant CAD, silent ischemia was fivefold more common than symptomatic ischemia (83% versus 17%, p = 0.0001). However, there were no differences in the extent, severity, or distribution of coronary stenoses in patients with silent or symptomatic ischemia. Our major observation was that the extent of quantified SPECT perfusion defects was nearly identical in patients with (20.9 +/- 15.9%) and without (20.5 +/- 15.6%) exertional chest pain. The sensitivity for detecting the presence of CAD was significantly improved with quantitative SPECT compared with stress electrocardiography (87% versus 65%, p = 0.0001). Although scintigraphic and electrocardiographic evidence of exercise-induced ischemia were comparable in patients with chest pain (67% versus 73%, respectively; p = NS), SPECT was superior to stress electrocardiography for detecting silent myocardial ischemia. The majority of patients in this study with CAD who developed ischemia during exercise testing were asymptomatic, although they exhibited an angiographic profile and extent of abnormally perfused myocardium similar to those of patients with symptomatic ischemia.

  6. Cardioplegia and myocardial preservation during cardiopulmonary bypass.

    PubMed

    Engelman, R M; Levitsky, S; O'Donoghue, M J; Auvil, J

    1978-09-01

    A standard experimental protocol was developed to explore the role of hypothermia and potassium cardioplegia in myocardial preservation during 120 minutes of ischemic arrest followed by 30 minutes of reperfusion. Seven different experimental groups of six animals each were evaluated using an in-vivo pig heart preparation. Hypothermic arrest without cardioplegia and cardioplegic arrest at normothermia were each compared to hypothermic cardioplegia. In addition, the use of an asanguineous hypothermic coronary perfusate without cardioplegia was compared to both multidose cardioplegia and single-dose cardioplegia followed by the same asanguineous perfusate. The parameters measured included: myocardial contractility and compliance, myocardial blood flow, endocardial/epicardial blood flow ratio, and electron microscopic studies. Myocardial preservation was inadequate with hypothermic arrest alone (without cardioplegia; and with cardioplegia at normothermia. In both experimental groups, myocardial contractility and compliance were so depressed that the) could not be accurately measured following ischemia and reperfusion while coronary blood flow remained significantly elevated. Preservation was improved but still inadequate following myocardial washout with a normokalemic or hypokalemic perfusate and following single dose cardioplegia plus myocardial washout. In the latter four groups, contractility ranged from 42 to 78% of control, and there was a decrease in compliance of 16 to 78%. Adequate preservation was found only after hypothermia and multidose potassium (35 mEq/L) cardioplegia. In this group, contractility was 129 +/- 13% of control and compliance increased by 21 +/- 24% compared to that of the control. PMID:14740689

  7. Determination of the Role of Oxygen in Suspected Acute Myocardial Infarction by Biomarkers

    ClinicalTrials.gov

    2016-01-25

    Acute Myocardial Infarction (AMI); Acute Coronary Syndrome (ACS); ST Elevation (STEMI) Myocardial Infarction; Ischemic Reperfusion Injury; Non-ST Elevation (NSTEMI) Myocardial Infarction; Angina, Unstable

  8. Evaluation of quantitative accuracy in CZT-based pre-clinical SPECT for various isotopes

    NASA Astrophysics Data System (ADS)

    Park, S.-J.; Yu, A. R.; Kim, Y.-s.; Kang, W.-S.; Jin, S. S.; Kim, J.-S.; Son, T. J.; Kim, H.-J.

    2015-05-01

    In vivo pre-clinical single-photon emission computed tomography (SPECT) is a valuable tool for functional small animal imaging, but several physical factors, such as scatter radiation, limit the quantitative accuracy of conventional scintillation crystal-based SPECT. Semiconductor detectors such as CZT overcome these deficiencies through superior energy resolution. To our knowledge, little scientific information exists regarding the accuracy of quantitative analysis in CZT-based pre-clinical SPECT systems for different isotopes. The aim of this study was to assess the quantitative accuracy of CZT-based pre-clinical SPECT for four isotopes: 201Tl, 99mTc, 123I, and 111In. The quantitative accuracy of the CZT-based Triumph X-SPECT (Gamma-Medica Ideas, Northridge, CA, U.S.A.) was compared with that of a conventional SPECT using GATE simulation. Quantitative errors due to the attenuation and scatter effects were evaluated for all four isotopes with energy windows of 5%, 10%, and 20%. A spherical source containing the isotope was placed at the center of the air-or-water-filled mouse-sized cylinder phantom. The CZT-based pre-clinical SPECT was more accurate than the conventional SPECT. For example, in the conventional SPECT with an energy window of 10%, scatter effects degraded quantitative accuracy by up to 11.52%, 5.10%, 2.88%, and 1.84% for 201Tl, 99mTc, 123I, and 111In, respectively. However, with the CZT-based pre-clinical SPECT, the degradations were only 9.67%, 5.45%, 2.36%, and 1.24% for 201Tl, 99mTc, 123I, and 111In, respectively. As the energy window was increased, the quantitative errors increased in both SPECT systems. Additionally, the isotopes with lower energy of photon emissions had greater quantitative error. Our results demonstrated that the CZT-based pre-clinical SPECT had lower overall quantitative errors due to reduced scatter and high detection efficiency. Furthermore, the results of this systematic assessment quantifying the accuracy of these SPECT

  9. Automatic estimation of detector radial position for contoured SPECT acquisition using CT images on a SPECT/CT system.

    PubMed

    Liu, Ruijie Rachel; Erwin, William D

    2006-08-01

    An algorithm was developed to estimate noncircular orbit (NCO) single-photon emission computed tomography (SPECT) detector radius on a SPECT/CT imaging system using the CT images, for incorporation into collimator resolution modeling for iterative SPECT reconstruction. Simulated male abdominal (arms up), male head and neck (arms down) and female chest (arms down) anthropomorphic phantom, and ten patient, medium-energy SPECT/CT scans were acquired on a hybrid imaging system. The algorithm simulated inward SPECT detector radial motion and object contour detection at each projection angle, employing the calculated average CT image and a fixed Hounsfield unit (HU) threshold. Calculated radii were compared to the observed true radii, and optimal CT threshold values, corresponding to patient bed and clothing surfaces, were found to be between -970 and -950 HU. The algorithm was constrained by the 45 cm CT field-of-view (FOV), which limited the detected radii to < or = 22.5 cm and led to occasional radius underestimation in the case of object truncation by CT. Two methods incorporating the algorithm were implemented: physical model (PM) and best fit (BF). The PM method computed an offset that produced maximum overlap of calculated and true radii for the phantom scans, and applied that offset as a calculated-to-true radius transformation. For the BF method, the calculated-to-true radius transformation was based upon a linear regression between calculated and true radii. For the PM method, a fixed offset of +2.75 cm provided maximum calculated-to-true radius overlap for the phantom study, which accounted for the camera system's object contour detect sensor surface-to-detector face distance. For the BF method, a linear regression of true versus calculated radius from a reference patient scan was used as a calculated-to-true radius transform. Both methods were applied to ten patient scans. For -970 and -950 HU thresholds, the combined overall average root-mean-square (rms

  10. Automatic estimation of detector radial position for contoured SPECT acquisition using CT images on a SPECT/CT system

    SciTech Connect

    Liu Ruijie Rachel; Erwin, William D.

    2006-08-15

    An algorithm was developed to estimate noncircular orbit (NCO) single-photon emission computed tomography (SPECT) detector radius on a SPECT/CT imaging system using the CT images, for incorporation into collimator resolution modeling for iterative SPECT reconstruction. Simulated male abdominal (arms up), male head and neck (arms down) and female chest (arms down) anthropomorphic phantom, and ten patient, medium-energy SPECT/CT scans were acquired on a hybrid imaging system. The algorithm simulated inward SPECT detector radial motion and object contour detection at each projection angle, employing the calculated average CT image and a fixed Hounsfield unit (HU) threshold. Calculated radii were compared to the observed true radii, and optimal CT threshold values, corresponding to patient bed and clothing surfaces, were found to be between -970 and -950 HU. The algorithm was constrained by the 45 cm CT field-of-view (FOV), which limited the detected radii to {<=}22.5 cm and led to occasional radius underestimation in the case of object truncation by CT. Two methods incorporating the algorithm were implemented: physical model (PM) and best fit (BF). The PM method computed an offset that produced maximum overlap of calculated and true radii for the phantom scans, and applied that offset as a calculated-to-true radius transformation. For the BF method, the calculated-to-true radius transformation was based upon a linear regression between calculated and true radii. For the PM method, a fixed offset of +2.75 cm provided maximum calculated-to-true radius overlap for the phantom study, which accounted for the camera system's object contour detect sensor surface-to-detector face distance. For the BF method, a linear regression of true versus calculated radius from a reference patient scan was used as a calculated-to-true radius transform. Both methods were applied to ten patient scans. For -970 and -950 HU thresholds, the combined overall average root-mean-square (rms) error

  11. Anatomical and functional imaging of myocardial infarction in mice using micro-CT and eXIA 160 contrast agent

    PubMed Central

    Ashton, Jeffrey R.; Befera, Nicholas; Clark, Darin; Qi, Yi; Mao, Lan; Rockman, Howard A.; Johnson, G. Allan; Badea, Cristian T.

    2014-01-01

    Non-invasive small animal imaging techniques are essential for evaluation of cardiac disease and potential therapeutics. A novel preclinical iodinated contrast agent called eXIA 160 has recently been developed, which has been evaluated for micro-CT cardiac imaging. eXIA 160 creates strong contrast between blood and tissue immediately after its injection and is subsequently taken up by the myocardium and other metabolically active tissues over time. We focus on these properties of eXIA and show its use in imaging myocardial infarction in mice. Five C57BL/6 mice were imaged ~ 2 weeks after LAD coronary artery ligation. Six C57BL/6 mice were used as controls. Immediately after injection of eXIA 160, an enhancement difference between blood and myocardium of ~340 HU enabled cardiac function estimation via 4D micro-CT scanning with retrospective gating. Four hours post-injection, the healthy perfused myocardium had a contrast difference of ~140 HU relative to blood while the infarcted myocardium showed no enhancement. These differences allowed quantification of infarct size via dual energy micro-CT. In vivo micro-SPECT imaging and ex vivo TTC staining provided validation for the micro-CT findings. Root mean squared error of infarct measurements was 2.7% between micro-CT and SPECT, and 4.7% between micro-CT and TTC. Thus, micro-CT with eXIA 160 can be used to provide both morphological and functional data for preclinical studies evaluating myocardial infarction and potential therapies. Further studies are warranted to study the potential use of eXIA 160 as a CT molecular imaging tool for other metabolically active tissues in the mouse. PMID:24523061

  12. 3D scintigraphic imaging and navigation in radioguided surgery: freehand SPECT technology and its clinical applications.

    PubMed

    Bluemel, Christina; Matthies, Philipp; Herrmann, Ken; Povoski, Stephen P

    2016-01-01

    Freehand SPECT (fhSPECT) is a technology platform for providing 3-dimensional (3D) navigation for radioguided surgical procedures, such as sentinel lymph node (SLN) biopsy (SLNB). In addition to the information provided by conventional handheld gamma detection probes, fhSPECT allows for direct visualization of the distribution of radioactivity in any given region of interest, allowing for improved navigation to radioactive target lesions and providing accurate lesion depth measurements. Herein, we will review the currently available clinical data on the use of fhSPECT: (i) for SLNB of various malignancies, including difficult-to-detect SLNs, and (ii) for radioguided localization of solid tumors. Moreover, the combination of fhSPECT with other technologies (e.g., small field-of-view gamma cameras, and diagnostic ultrasound) is discussed. These technical advances have the potential to greatly expand the clinical application of radioguided surgery in the future. PMID:26878667

  13. Design and performance of a multi-pinhole collimation device for small animal imaging with clinical SPECT and SPECT CT scanners

    NASA Astrophysics Data System (ADS)

    Di Filippo, Frank P.

    2008-08-01

    A multi-pinhole collimation device is developed that uses the gamma camera detectors of a clinical SPECT or SPECT-CT scanner to produce high-resolution SPECT images. The device consists of a rotating cylindrical collimator having 22 tungsten pinholes with 0.9 mm diameter apertures and an animal bed inside the collimator that moves linearly to provide helical or ordered-subsets axial sampling. CT images also may be acquired on a SPECT-CT scanner for purposes of image co-registration and SPECT attenuation correction. The device is placed on the patient table of the scanner without attaching to the detectors or scanner gantry. The system geometry is calibrated in-place from point source data and is then used during image reconstruction. The SPECT imaging performance of the device is evaluated with test phantom scans. Spatial resolution from reconstructed point source images is measured to be 0.6 mm full width at half maximum or better. Micro-Derenzo phantom images demonstrate the ability to resolve 0.7 mm diameter rod patterns. The axial slabs of a Micro-Defrise phantom are visualized well. Collimator efficiency exceeds 0.05% at the center of the field of view, and images of a uniform phantom show acceptable uniformity and minimal artifact. The overall simplicity and relatively good imaging performance of the device make it an interesting low-cost alternative to dedicated small animal scanners.

  14. Migration of bone marrow-derived cells and improved perfusion after treatment with erythropoietin in a murine model of myocardial infarction

    PubMed Central

    Brunner, Stefan; Huber, Bruno C; Weinberger, Tobias; Vallaster, Marcus; Wollenweber, Tim; Gerbitz, Armin; Hacker, Marcus; Franz, Wolfgang-Michael

    2012-01-01

    Abstract Erythropoietin (EPO) was shown to have protective effects after myocardial infarction (MI) by neovascularization and antiapoptotic mechanisms. Beside direct receptor-dependent mechanisms, mobilization and homing of bone marrow-derived cells (BMCs) may play a pivotal role in this regard. In this study, we intended to track different subpopulations of BMCs and to assess serially myocardial perfusion changes in EPO-treated mice after MI. To allow tracking of BMCs, we used a chimeric mouse model. Therefore, mice (C57BL/6J) were sublethally irradiated, and bone marrow (BM) from green fluorescent protein transgenic mice was transplanted. Ten weeks later coronary artery ligation was performed to induce MI. EPO was injected for 3 days with a total dose of 5000 IU/kg. Subpopulations (CD31, c-kit, CXCR-4 and Sca-1) of EGFP+ cells were studied in peripheral blood, bone marrow and hearts by flow cytometry. Myocardial perfusion was serially investigated in vivo by pinhole single-photon emission computed tomography (SPECT) at days 6 and 30 after MI. EPO-treated animals revealed an enhanced mobilization of BMCs into peripheral blood. The numbers of these cells in BM remained unchanged. Homing of all BMCs subpopulations to the ischaemic myocardium was significantly increased in EPO-treated mice. Among the investigated subpopulations, EPO predominantly affected migration of CXCR-4+ (4.3-fold increase). Repetitively SPECT analyses revealed a reduction of perfusion defects after EPO treatment over time. Our study shows that EPO treatment after MI enhances the migration capacity of BMCs into ischaemic tissue, which may attribute to an improved perfusion and reduced size of infarction, respectively. PMID:21362129

  15. A multipinhole small animal SPECT system with submillimeter spatial resolution

    SciTech Connect

    Funk, Tobias; Despres, Philippe; Barber, William C.; Shah, Kanai S.; Hasegawa, Bruce H.

    2006-05-15

    Single photon emission computed tomography (SPECT) is an important technology for molecular imaging studies of small animals. In this arena, there is an increasing demand for high performance imaging systems that offer improved spatial resolution and detection efficiency. We have designed a multipinhole small animal imaging system based on position sensitive avalanche photodiode (PSAPD) detectors with the goal of submillimeter spatial resolution and high detection efficiency, which will allow us to minimize the radiation dose to the animal and to shorten the time needed for the imaging study. Our design will use 8x24 mm{sup 2} PSAPD detector modules coupled to thallium-doped cesium iodide [CsI(Tl)] scintillators, which can achieve an intrinsic spatial resolution of 0.5 mm at 140 keV. These detectors will be arranged in rings of 24 modules each; the animal is positioned in the center of the 9 stationary detector rings which capture projection data from the animal with a cylindrical tungsten multipinhole collimator. The animal is supported on a bed which can be rocked about the central axis to increase angular sampling of the object. In contrast to conventional SPECT pinhole systems, in our design each pinhole views only a portion of the object. However, the ensemble of projection data from all of the multipinhole detectors provide angular sampling that is sufficient to reconstruct tomographic data from the object. The performance of this multipinhole PSAPD imaging system was simulated using a ray tracing program that models the appropriate point spread functions and then was compared against the performance of a dual-headed pinhole SPECT system. The detection efficiency of both systems was simulated and projection data of a hot rod phantom were generated and reconstructed to assess spatial resolution. Appropriate Poisson noise was added to the data to simulate an acquisition time of 15 min and an activity of 18.5 MBq distributed in the phantom. Both sets of data

  16. Ventricular Aneurysm Following Myocardial Infarction

    PubMed Central

    Walters, M. B.

    1966-01-01

    Cineradiographic examination appears to be the best method for the study of cardiac pulsations. Fifty consecutive patients, who had sustained transmural myocardial infarction at least six months previously, were studied by this technique. Thirty-six had some abnormality of pulsation and eight had dynamic ventricular aneurysm. Six of the eight had suffered severe infarct. Functional recovery in those with aneurysm was not as complete as in the rest of the group. Two made a poor functional recovery, two a fair recovery, and four a moderately good recovery. Clinically, there were no systemic emboli in the patients with dynamic aneurysms. Five of the 50 had persistent ST-segment elevation and “coving” of the T waves; three of these patients had aneurysms. There was no good correlation between the electrocardiographic site of the infarct and the site of the abnormal pulsation. ImagesFig. 1 PMID:5928534

  17. Myocardial infarction in young adults

    PubMed Central

    Egred, M; Viswanathan, G; Davis, G

    2005-01-01

    Although myocardial infarction (MI) mainly occurs in patients older than 45, young men or women can suffer MI. Fortunately, its incidence is not common in patients younger than 45 years. However, the disease carries a significant morbidity, psychological effects, and financial constraints for the person and the family when it occurs at a young age. The causes of MI among patients aged less than 45 can be divided into four groups: (1) atheromatous coronary artery disease; (2) non-atheromatous coronary artery disease; (2) hyper-coagulable states; (4) MI related to substance misuse. There is a considerable overlap between all the groups. This article reviews the literature and highlights the practical issues involved in the management of young adults with MI. PMID:16344295

  18. Multipinhole collimator with 20 apertures for a brain SPECT application

    SciTech Connect

    Lee, Tzu-Cheng; Ellin, Justin R.; Shrestha, Uttam; Seo, Youngho; Huang, Qiu; Gullberg, Grant T.

    2014-11-01

    Purpose: Several new technologies for single photon emission computed tomography (SPECT) instrumentation with parallel-hole collimation have been proposed to improve detector sensitivity and signal collection efficiency. Benefits from improved signal efficiency include shorter acquisition times and lower dose requirements. In this paper, the authors show a possibility of over an order of magnitude enhancement in photon detection efficiency (from 7.6 × 10{sup −5} to 1.6 × 10{sup −3}) for dopamine transporter (DaT) imaging of the striatum over the conventional SPECT parallel-hole collimators by use of custom-designed 20 multipinhole (20-MPH) collimators with apertures of 0.75 cm diameter. Methods: Quantifying specific binding ratio (SBR) of {sup 123}I-ioflupane or {sup 123}I-iometopane’s signal at the striatal region is a common brain imaging method to confirm the diagnosis of the Parkinson’s disease. The authors performed imaging of a striatal phantom filled with aqueous solution of I-123 and compared camera recovery ratios of SBR acquired between low-energy high-resolution (LEHR) parallel-hole collimators and 20-MPH collimators. Results: With only two-thirds of total acquisition time (20 min against 30 min), a comparable camera recovery ratio of SBR was achieved using 20-MPH collimators in comparison to that from the LEHR collimator study. Conclusions: Their systematic analyses showed that the 20-MPH collimator could be a promising alternative for the DaT SPECT imaging for brain over the traditional LEHR collimator, which could give both shorter scan time and improved diagnostic accuracy.

  19. Impact of reconstruction parameters on quantitative I-131 SPECT.

    PubMed

    van Gils, C A J; Beijst, C; van Rooij, R; de Jong, H W A M

    2016-07-21

    Radioiodine therapy using I-131 is widely used for treatment of thyroid disease or neuroendocrine tumors. Monitoring treatment by accurate dosimetry requires quantitative imaging. The high energy photons however render quantitative SPECT reconstruction challenging, potentially requiring accurate correction for scatter and collimator effects. The goal of this work is to assess the effectiveness of various correction methods on these effects using phantom studies. A SPECT/CT acquisition of the NEMA IEC body phantom was performed. Images were reconstructed using the following parameters: (1) without scatter correction, (2) with triple energy window (TEW) scatter correction and (3) with Monte Carlo-based scatter correction. For modelling the collimator-detector response (CDR), both (a) geometric Gaussian CDRs as well as (b) Monte Carlo simulated CDRs were compared. Quantitative accuracy, contrast to noise ratios and recovery coefficients were calculated, as well as the background variability and the residual count error in the lung insert. The Monte Carlo scatter corrected reconstruction method was shown to be intrinsically quantitative, requiring no experimentally acquired calibration factor. It resulted in a more accurate quantification of the background compartment activity density compared with TEW or no scatter correction. The quantification error relative to a dose calibrator derived measurement was found to be  <1%,-26% and 33%, respectively. The adverse effects of partial volume were significantly smaller with the Monte Carlo simulated CDR correction compared with geometric Gaussian or no CDR modelling. Scatter correction showed a small effect on quantification of small volumes. When using a weighting factor, TEW correction was comparable to Monte Carlo reconstruction in all measured parameters, although this approach is clinically impractical since this factor may be patient dependent. Monte Carlo based scatter correction including accurately simulated CDR

  20. Impact of reconstruction parameters on quantitative I-131 SPECT

    NASA Astrophysics Data System (ADS)

    van Gils, C. A. J.; Beijst, C.; van Rooij, R.; de Jong, H. W. A. M.

    2016-07-01

    Radioiodine therapy using I-131 is widely used for treatment of thyroid disease or neuroendocrine tumors. Monitoring treatment by accurate dosimetry requires quantitative imaging. The high energy photons however render quantitative SPECT reconstruction challenging, potentially requiring accurate correction for scatter and collimator effects. The goal of this work is to assess the effectiveness of various correction methods on these effects using phantom studies. A SPECT/CT acquisition of the NEMA IEC body phantom was performed. Images were reconstructed using the following parameters: (1) without scatter correction, (2) with triple energy window (TEW) scatter correction and (3) with Monte Carlo-based scatter correction. For modelling the collimator-detector response (CDR), both (a) geometric Gaussian CDRs as well as (b) Monte Carlo simulated CDRs were compared. Quantitative accuracy, contrast to noise ratios and recovery coefficients were calculated, as well as the background variability and the residual count error in the lung insert. The Monte Carlo scatter corrected reconstruction method was shown to be intrinsically quantitative, requiring no experimentally acquired calibration factor. It resulted in a more accurate quantification of the background compartment activity density compared with TEW or no scatter correction. The quantification error relative to a dose calibrator derived measurement was found to be  <1%,‑26% and 33%, respectively. The adverse effects of partial volume were significantly smaller with the Monte Carlo simulated CDR correction compared with geometric Gaussian or no CDR modelling. Scatter correction showed a small effect on quantification of small volumes. When using a weighting factor, TEW correction was comparable to Monte Carlo reconstruction in all measured parameters, although this approach is clinically impractical since this factor may be patient dependent. Monte Carlo based scatter correction including accurately simulated

  1. [Thrombolytic treatment of acute myocardial infarct. 1].

    PubMed

    Soares-Costa, J T; Soares-Costa, T J; Gabriel, H M

    1998-05-01

    I-Rationale of thrombolytic therapy in acute myocardial infarction (AMI). II-Thrombolytic drugs. III-Effects of thrombolytic therapy on mortality. IV-Studies comparing the effects of various thrombolytic agents on mortality. PMID:9951051

  2. Imaging of myocardial fatty acid oxidation.

    PubMed

    Mather, Kieren J; DeGrado, Timothy R

    2016-10-01

    Myocardial fuel selection is a key feature of the health and function of the heart, with clear links between myocardial function and fuel selection and important impacts of fuel selection on ischemia tolerance. Radiopharmaceuticals provide uniquely valuable tools for in vivo, non-invasive assessment of these aspects of cardiac function and metabolism. Here we review the landscape of imaging probes developed to provide non-invasive assessment of myocardial fatty acid oxidation (MFAO). Also, we review the state of current knowledge that myocardial fatty acid imaging has helped establish of static and dynamic fuel selection that characterizes cardiac and cardiometabolic disease and the interplay between fuel selection and various aspects of cardiac function. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk. PMID:26923433

  3. Repetitive Myocardial Infarctions Secondary to Delirium Tremens

    PubMed Central

    Schwartzberg, David; Shiroff, Adam

    2014-01-01

    Delirium tremens develops in a minority of patients undergoing acute alcohol withdrawal; however, that minority is vulnerable to significant morbidity and mortality. Historically, benzodiazepines are given intravenously to control withdrawal symptoms, although occasionally a more substantial medication is needed to prevent the devastating effects of delirium tremens, that is, propofol. We report a trauma patient who required propofol sedation for delirium tremens that was refractory to benzodiazepine treatment. Extubed prematurely, he suffered a non-ST segment myocardial infarction followed by an ST segment myocardial infarction requiring multiple interventions by cardiology. We hypothesize that his myocardial ischemia was secondary to an increased myocardial oxygen demand that occurred during his stress-induced catecholamine surge during the time he was undertreated for delirium tremens. This advocates for the use of propofol for refractory benzodiazepine treatment of delirium tremens and adds to the literature on the instability patients experience during withdrawal. PMID:25197580

  4. Repetitive myocardial infarctions secondary to delirium tremens.

    PubMed

    Schwartzberg, David; Shiroff, Adam

    2014-01-01

    Delirium tremens develops in a minority of patients undergoing acute alcohol withdrawal; however, that minority is vulnerable to significant morbidity and mortality. Historically, benzodiazepines are given intravenously to control withdrawal symptoms, although occasionally a more substantial medication is needed to prevent the devastating effects of delirium tremens, that is, propofol. We report a trauma patient who required propofol sedation for delirium tremens that was refractory to benzodiazepine treatment. Extubed prematurely, he suffered a non-ST segment myocardial infarction followed by an ST segment myocardial infarction requiring multiple interventions by cardiology. We hypothesize that his myocardial ischemia was secondary to an increased myocardial oxygen demand that occurred during his stress-induced catecholamine surge during the time he was undertreated for delirium tremens. This advocates for the use of propofol for refractory benzodiazepine treatment of delirium tremens and adds to the literature on the instability patients experience during withdrawal. PMID:25197580

  5. Myocardial hypoperfusion on conventional contrast computed tomography.

    PubMed

    Ching, Shing; Chung, Tak Shun

    2015-10-01

    Non–electrocardiogram (ECG)–gated contrast computed tomography (CT) is commonly performed to exclude aortic dissection in chest pain patients. Besides evaluating the aorta for dissection flap, attention should be paid to the myocardium for areas of hypoenhancement that may suggest ischemia. Current models of multidetector CT enable assessment of myocardial perfusion with minimal motion artifact even without ECG gating. Transmural hypoenhancement with preserved wall thickness in a coronary distribution is highly specific for acute myocardial infarction. We report 2 cases of acute chest pain with initial nondiagnostic studies that underwent CT aortogram to exclude dissection. Instead, the CT showed myocardial hypoenhancement in left anterior descending artery territory. Myocardial hypoenhancement occurred before ST-segment elevation on ECG, suggesting that recognition of this important finding may lead to earlier revascularization decisions. PMID:26321167

  6. High Sensitivity SPECT for Small Animals and Plants

    SciTech Connect

    Mitchell, Gregory S.

    2015-02-28

    Imaging systems using single gamma-ray emitting radioisotopes typically implement collimators in order to form the images. However, a tradeoff in sensitivity is inherent in the use of collimators, and modern preclinical single-photon emission computed tomography (SPECT) systems detect a very small fraction of emitted gamma-rays (<0.3%). We have built a collimator-less system, which can reach sensitivity of 40% for 99mTc imaging, while still producing images of sufficient spatial resolution for certain applications in thin objects such as mice, small plants, and well plates used for in vitro experiments.

  7. Monte Carlo simulation of PET and SPECT imaging of {sup 90}Y

    SciTech Connect

    Takahashi, Akihiko Sasaki, Masayuki; Himuro, Kazuhiko; Yamashita, Yasuo; Komiya, Isao; Baba, Shingo

    2015-04-15

    Purpose: Yittrium-90 ({sup 90}Y) is traditionally thought of as a pure beta emitter, and is used in targeted radionuclide therapy, with imaging performed using bremsstrahlung single-photon emission computed tomography (SPECT). However, because {sup 90}Y also emits positrons through internal pair production with a very small branching ratio, positron emission tomography (PET) imaging is also available. Because of the insufficient image quality of {sup 90}Y bremsstrahlung SPECT, PET imaging has been suggested as an alternative. In this paper, the authors present the Monte Carlo-based simulation–reconstruction framework for {sup 90}Y to comprehensively analyze the PET and SPECT imaging techniques and to quantitatively consider the disadvantages associated with them. Methods: Our PET and SPECT simulation modules were developed using Monte Carlo simulation of Electrons and Photons (MCEP), developed by Dr. S. Uehara. PET code (MCEP-PET) generates a sinogram, and reconstructs the tomography image using a time-of-flight ordered subset expectation maximization (TOF-OSEM) algorithm with attenuation compensation. To evaluate MCEP-PET, simulated results of {sup 18}F PET imaging were compared with the experimental results. The results confirmed that MCEP-PET can simulate the experimental results very well. The SPECT code (MCEP-SPECT) models the collimator and NaI detector system, and generates the projection images and projection data. To save the computational time, the authors adopt the prerecorded {sup 90}Y bremsstrahlung photon data calculated by MCEP. The projection data are also reconstructed using the OSEM algorithm. The authors simulated PET and SPECT images of a water phantom containing six hot spheres filled with different concentrations of {sup 90}Y without background activity. The amount of activity was 163 MBq, with an acquisition time of 40 min. Results: The simulated {sup 90}Y-PET image accurately simulated the experimental results. PET image is visually

  8. [The latest treatments for myocardial infarction].

    PubMed

    Leclercq, Florence

    2015-03-01

    Ischemic heart disease and its main complication, myocardial infarction, remain the leading cause of death after the age of forty in developed countries. Myocardial infarction is the consequence of a sudden obstruction of a coronary artery by a thrombus. Thrombolysis and coronary angioplasty are the two emergency coronary artery revascularisation techniques. A medication-based treatment and adapted lifestyle aim to prevent repeat infarction. PMID:26040139

  9. Myocardial perfusion imaging with 201Tl.

    PubMed

    Pagnanelli, Robert A; Basso, Danny A

    2010-03-01

    The object of this review is to provide information about (201)Tl-thallous chloride in radionuclide myocardial perfusion imaging. This technique has experienced a recent resurgence because of the shortage of (99m)Tc. After reading this article, the technologist will be able to describe the properties and uptake mechanism of (201)Tl, the procedure for myocardial perfusion imaging with this agent, and the advantages and disadvantages of thallium, compared with the technetium agents. PMID:20159930

  10. Improved exercise myocardial perfusion during lidoflazine therapy

    SciTech Connect

    Shapiro, W.; Narahara, K.A.; Park, J.

    1983-11-01

    Lidoflazine is a synthetic drug with calcium-channel blocking effects. In a study of 6 patients with severe classic angina pectoris, single-blind administration of lidoflazine was associated with improved myocardial perfusion during exercise as determined by thallium-201 stress scintigraphy. These studies demonstrate that lidoflazine therapy is associated with relief of angina, an increased physical work capacity, and improved regional myocardial perfusion during exercise.

  11. Relationship between myocardial bridging and coronary arteriosclerosis.

    PubMed

    Sun, Jian Ling; Huang, Wei Min; Guo, Ji Hong; Li, Xiao Ying; Ma, Xian Lin; Wang, Chong Yu

    2013-04-01

    The objective of the study was to explore the prevalence and characteristics of myocardial bridging in patients who underwent coronary angiography and to also evaluate the correlation between bridged coronary segments and atherosclerosis. For this purpose, clinical materials of 1,500 patients who had received coronary angiography were retrospectively analyzed. The location and length of the myocardial bridge were recorded as well as the extent and location of coronary artery stenosis was described. Segments proximal and distal to the bridging were evaluated for coronary arteriosclerosis as were the remaining coronary segments. We found that myocardial bridging was present in 179 (11.9 %) patients. Bridges were frequently (84.9 %) localized in the mid-distal segment of the left anterior descending (LAD) artery. Myocardial bridging was not considered a significant risk factor for coronary atherosclerosis (odds ratio 0.58) compared with traditional cardiovascular risk factors. The incidence of coronary arteriosclerosis in the distal segments was significantly less affected than the proximal segments (P < 0.01). It was, therefore, concluded that myocardial bridging frequently localized in the mid-distal segment of the LAD artery. The presence of myocardial bridging promotes proximal atherosclerosis but it is not an additional risk factor for coronary atherosclerosis. PMID:23076634

  12. Computational modeling of acute myocardial infarction.

    PubMed

    Sáez, P; Kuhl, E

    2016-01-01

    Myocardial infarction, commonly known as heart attack, is caused by reduced blood supply and damages the heart muscle because of a lack of oxygen. Myocardial infarction initiates a cascade of biochemical and mechanical events. In the early stages, cardiomyocytes death, wall thinning, collagen degradation, and ventricular dilation are the immediate consequences of myocardial infarction. In the later stages, collagenous scar formation in the infarcted zone and hypertrophy of the non-infarcted zone are auto-regulatory mechanisms to partly correct for these events. Here we propose a computational model for the short-term adaptation after myocardial infarction using the continuum theory of multiplicative growth. Our model captures the effects of cell death initiating wall thinning, and collagen degradation initiating ventricular dilation. Our simulations agree well with clinical observations in early myocardial infarction. They represent a first step toward simulating the progression of myocardial infarction with the ultimate goal to predict the propensity toward heart failure as a function of infarct intensity, location, and size. PMID:26583449

  13. Myocardial Sleeve Tissues in Surgical Lung Specimens.

    PubMed

    Yoshida, Akihiko; Kamata, Tsugumasa; Iwasa, Takeshi; Watanabe, Shun-ichi; Tsuta, Koji

    2015-10-01

    Left atrial myocardial extensions over the pulmonary veins (PVs), known as myocardial sleeves, are present in the physiological anatomy of most individuals. Although this structure has recently received clinical attention as a major origin of paroxysmal atrial fibrillation (AF), it has not been documented in surgical specimens. Here, we examine incidentally identified myocardial sleeve tissue in routinely processed lung resection specimens to determine its incidence and diagnostic implications. Among 694 lung resection specimens with evaluable PV margins, myocardial sleeve tissue was identified in 26 cases (3.7%). The tissue was located within the adventitia of the PVs, mostly in margin preparations, and existed outside the pericardium in the majority of cases. Carcinoma infiltration of the sleeves was evident in 6 cases. No heart injuries were observed, and no tumors invaded the heart. Preoperative electrocardiography showed sinus rhythm in all cases, whereas postoperative monitoring revealed sinus rhythm in all patients except one who showed AF and flutter. Myocardial sleeve tissue is an underrecognized incidental finding in lung resection specimens, and it is not indicative of heart injury. Cancer infiltration into this tissue indicates neither heart invasion nor, by itself, invasion into the pericardium. Although surgical transection of the myocardial sleeve did not evoke immediate arrhythmia in most cases, the overall influence of this procedure on the postsurgical risk of AF remains to be determined in further studies involving extensive rhythm assessment. PMID:26099012

  14. Myocardial Dysfunction and Shock after Cardiac Arrest

    PubMed Central

    Jentzer, Jacob C.; Chonde, Meshe D.; Dezfulian, Cameron

    2015-01-01

    Postarrest myocardial dysfunction includes the development of low cardiac output or ventricular systolic or diastolic dysfunction after cardiac arrest. Impaired left ventricular systolic function is reported in nearly two-thirds of patients resuscitated after cardiac arrest. Hypotension and shock requiring vasopressor support are similarly common after cardiac arrest. Whereas shock requiring vasopressor support is consistently associated with an adverse outcome after cardiac arrest, the association between myocardial dysfunction and outcomes is less clear. Myocardial dysfunction and shock after cardiac arrest develop as the result of preexisting cardiac pathology with multiple superimposed insults from resuscitation. The pathophysiology involves cardiovascular ischemia/reperfusion injury and cardiovascular toxicity from excessive levels of inflammatory cytokine activation and catecholamines, among other contributing factors. Similar mechanisms occur in myocardial dysfunction after cardiopulmonary bypass, in sepsis, and in stress-induced cardiomyopathy. Hemodynamic stabilization after resuscitation from cardiac arrest involves restoration of preload, vasopressors to support arterial pressure, and inotropic support if needed to reverse the effects of myocardial dysfunction and improve systemic perfusion. Further research is needed to define the role of postarrest myocardial dysfunction on cardiac arrest outcomes and identify therapeutic strategies. PMID:26421284

  15. Onboard functional and molecular imaging: A design investigation for robotic multipinhole SPECT

    SciTech Connect

    Bowsher, James Giles, William; Yin, Fang-Fang; Yan, Susu; Roper, Justin

    2014-01-15

    Purpose: Onboard imaging—currently performed primarily by x-ray transmission modalities—is essential in modern radiation therapy. As radiation therapy moves toward personalized medicine, molecular imaging, which views individual gene expression, may also be important onboard. Nuclear medicine methods, such as single photon emission computed tomography (SPECT), are premier modalities for molecular imaging. The purpose of this study is to investigate a robotic multipinhole approach to onboard SPECT. Methods: Computer-aided design (CAD) studies were performed to assess the feasibility of maneuvering a robotic SPECT system about a patient in position for radiation therapy. In order to obtain fast, high-quality SPECT images, a 49-pinhole SPECT camera was designed which provides high sensitivity to photons emitted from an imaging region of interest. This multipinhole system was investigated by computer-simulation studies. Seventeen hot spots 10 and 7 mm in diameter were placed in the breast region of a supine female phantom. Hot spot activity concentration was six times that of background. For the 49-pinhole camera and a reference, more conventional, broad field-of-view (FOV) SPECT system, projection data were computer simulated for 4-min scans and SPECT images were reconstructed. Hot-spot localization was evaluated using a nonprewhitening forced-choice numerical observer. Results: The CAD simulation studies found that robots could maneuver SPECT cameras about patients in position for radiation therapy. In the imaging studies, most hot spots were apparent in the 49-pinhole images. Average localization errors for 10-mm- and 7-mm-diameter hot spots were 0.4 and 1.7 mm, respectively, for the 49-pinhole system, and 3.1 and 5.7 mm, respectively, for the reference broad-FOV system. Conclusions: A robot could maneuver a multipinhole SPECT system about a patient in position for radiation therapy. The system could provide onboard functional and molecular imaging with 4-min

  16. Onboard functional and molecular imaging: A design investigation for robotic multipinhole SPECT

    PubMed Central

    Bowsher, James; Yan, Susu; Roper, Justin; Giles, William; Yin, Fang-Fang

    2014-01-01

    Purpose: Onboard imaging—currently performed primarily by x-ray transmission modalities—is essential in modern radiation therapy. As radiation therapy moves toward personalized medicine, molecular imaging, which views individual gene expression, may also be important onboard. Nuclear medicine methods, such as single photon emission computed tomography (SPECT), are premier modalities for molecular imaging. The purpose of this study is to investigate a robotic multipinhole approach to onboard SPECT. Methods: Computer-aided design (CAD) studies were performed to assess the feasibility of maneuvering a robotic SPECT system about a patient in position for radiation therapy. In order to obtain fast, high-quality SPECT images, a 49-pinhole SPECT camera was designed which provides high sensitivity to photons emitted from an imaging region of interest. This multipinhole system was investigated by computer-simulation studies. Seventeen hot spots 10 and 7 mm in diameter were placed in the breast region of a supine female phantom. Hot spot activity concentration was six times that of background. For the 49-pinhole camera and a reference, more conventional, broad field-of-view (FOV) SPECT system, projection data were computer simulated for 4-min scans and SPECT images were reconstructed. Hot-spot localization was evaluated using a nonprewhitening forced-choice numerical observer. Results: The CAD simulation studies found that robots could maneuver SPECT cameras about patients in position for radiation therapy. In the imaging studies, most hot spots were apparent in the 49-pinhole images. Average localization errors for 10-mm- and 7-mm-diameter hot spots were 0.4 and 1.7 mm, respectively, for the 49-pinhole system, and 3.1 and 5.7 mm, respectively, for the reference broad-FOV system. Conclusions: A robot could maneuver a multipinhole SPECT system about a patient in position for radiation therapy. The system could provide onboard functional and molecular imaging with 4-min

  17. Detection of Sentinel Lymph Nodes in Gynecologic Tumours by Planar Scintigraphy and SPECT/CT

    PubMed Central

    Kraft, Otakar; Havel, Martin

    2012-01-01

    Objective: Assess the role of planar lymphoscintigraphy and fusion imaging of SPECT/CT in sentinel lymph node (SLN) detection in patients with gynecologic tumours. Material and Methods: Planar scintigraphy and hybrid modality SPECT/CT were performed in 64 consecutive women with gynecologic tumours (mean age 53.6 with range 30-77 years): 36 pts with cervical cancer (Group A), 21 pts with endometrial cancer (Group B), 7 pts with vulvar carcinoma (Group C). Planar and SPECT/CT images were interpreted separately by two nuclear medicine physicians. Efficacy of these two techniques to image SLN were compared. Results: Planar scintigraphy did not image SLN in 7 patients (10.9%), SPECT/CT was negative in 4 patients (6.3%). In 35 (54.7%) patients the number of SLNs captured on SPECT/CT was higher than on planar imaging. Differences in detection of SLN between planar and SPECT/CT imaging in the group of all 64 patients are statistically significant (p<0.05). Three foci of uptake (1.7% from totally visible 177 foci on planar images) in 2 patients interpreted on planar images as hot LNs were found to be false positive non-nodal sites of uptake when further assessed on SPECT/CT. SPECT/CT showed the exact anatomical location of all visualised sentinel nodes. Conclusion: In some patients with gynecologic cancers SPECT/CT improves detection of sentinel lymph nodes. It can image nodes not visible on planar scintigrams, exclude false positive uptake and exactly localise pelvic and paraaortal SLNs. It improves anatomic localization of SLNs. Conflict of interest:None declared. PMID:23486989

  18. Apelin-13 protects against myocardial infarction-induced myocardial fibrosis.

    PubMed

    Zhang, Xuemin; Hu, Wenyu; Feng, Feng; Xu, Jian; Wu, Fang

    2016-06-01

    Myocardial infarction is a serious health threat. Apelin is an endogenous ligand of angiotensin II receptor-like 1 (APJ) and the apelin/APJ system is associated with various types of heart disease. However, whether apelin protects against myocardial infarction‑induced myocardial fibrosis remains unclear. The present study aimed to investigate the function of apelin‑13 during myocardial infarction‑induced myocardial fibrosis, and to determine the mechanism underlying the effects of apelin‑13. Apelin‑13 was demonstrated to improve left ventricular function and results of hematoxylin and eosin staining, Masson's trichrome staining and western blotting showed that apelin‑13 attenuated myocardial fibrosis. Further mechanistic investigation was performed by enzyme‑linked immunosorbent assay, western blotting and electrophoretic mobility shift assay. The results demonstrated that apelin‑13 inhibited the activation of nuclear factor (NF)‑κB signaling in vitro and in vivo. To the best of our knowledge, the present study was the first to demonstrate that apelin‑13 may attenuate myocardial infarction‑induced myocardial fibrosis, and that this protective function may be mediated by inhibition of NF‑κB signaling. The present study suggests a theoretical basis for the effects of apelin‑13 and provides insight into the potential clinical application of apelin-13. PMID:27109054

  19. Simultaneous CT and SPECT tomography using CZT detectors

    DOEpatents

    Paulus, Michael J.; Sari-Sarraf, Hamed; Simpson, Michael L.; Britton, Jr., Charles L.

    2002-01-01

    A method for simultaneous transmission x-ray computed tomography (CT) and single photon emission tomography (SPECT) comprises the steps of: injecting a subject with a tracer compound tagged with a .gamma.-ray emitting nuclide; directing an x-ray source toward the subject; rotating the x-ray source around the subject; emitting x-rays during the rotating step; rotating a cadmium zinc telluride (CZT) two-sided detector on an opposite side of the subject from the source; simultaneously detecting the position and energy of each pulsed x-ray and each emitted .gamma.-ray captured by the CZT detector; recording data for each position and each energy of each the captured x-ray and .gamma.-ray; and, creating CT and SPECT images from the recorded data. The transmitted energy levels of the x-rays lower are biased lower than energy levels of the .gamma.-rays. The x-ray source is operated in a continuous mode. The method can be implemented at ambient temperatures.

  20. SPECT in Alzheimer`s disease and the dementias

    SciTech Connect

    Bonte, F.J.

    1991-12-31

    Among 90 patients with a clinical diagnosis of Alzheimer`s disease (AD), two subgroups were identified for special study, including 42 patients who had a history of dementia in one or more first-degree relatives, and 14 who had a diagnosis of early AD. Of the 42 patients with a family history of dementia, 34 out of the 35 patients whose final clinical diagnosis was possible or probable AD had positive SPECT rCBF studies. Studies in the 14 patients thought to have very early AD were positive in 11 cases. This finding suggests that altered cortical physiology, and hence, rCBF, occurs quite early in the course of AD, perhaps before the onset of symptoms. It is possible that Xenon 133 rCBF studies might be used to detect the presence of subclinical AD in a population of individuals at risk to this disorder. Despite the drawbacks of a radionuclide with poor photon energy, Xenon 133, with its low cost and round-the-clock availability, deserves further study. Although the physical characteristics of Xenon 127 might make it preferable as a SPECT tracer, it is still not regularly available, and some instrument systems are not designed to handle its higher photon energies.

  1. Applications of SPECT imaging of dopaminergic neurotransmission in neuropsychiatric disorders.

    PubMed

    Kugaya, A; Fujita, M; Innis, R B

    2000-02-01

    Single photon emission computed tomography (SPECT) tracers selective for pre- and post-synaptic targets have allowed measurements of several aspects of dopaminergic (DA) neurotransmission. In this article, we will first review our DA transporter imaging in Parkinson's disease. We have developed the in vivo dopamine transporter (DAT) imaging with [123I]beta-CIT ((1R)-2beta-Carbomethoxy-3beta-(4-iodophenyl)tropane). This method showed that patients with Parkinson's disease have markedly reduced DAT levels in striatum, which correlated with disease severity and disease progression. Second, we applied DA imaging techniques in patients with schizophrenia. Using amphetamine as a releaser of DA, we observed the enhanced DA release, which was measured by imaging D2 receptors with [123I]IBZM (iodobenzamide), in schizophrenics. Further we developed the measurement of basal synaptic DA levels by AMPT (alpha-methyl-paratyrosine)-induced unmasking of D2 receptors. Finally, we expanded our techniques to the measurement of extrastriatal DA receptors using [123I]epidepride. The findings suggest that SPECT is a useful technique to measure DA transmission in human brain and may further our understanding of the pathophysiology of neuropsychiatric disorders. PMID:10770574

  2. Development of PET and SPECT Probes for Glutamate Receptors

    PubMed Central

    Nakayama, Morio

    2015-01-01

    l-Glutamate and its receptors (GluRs) play a key role in excitatory neurotransmission within the mammalian central nervous system (CNS). Impaired regulation of GluRs has also been implicated in various neurological disorders. GluRs are classified into two major groups: ionotropic GluRs (iGluRs), which are ligand-gated ion channels, and metabotropic GluRs (mGluRs), which are coupled to heterotrimeric guanosine nucleotide binding proteins (G-proteins). Positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging of GluRs could provide a novel view of CNS function and of a range of brain disorders, potentially leading to the development of new drug therapies. Although no satisfactory imaging agents have yet been developed for iGluRs, several PET ligands for mGluRs have been successfully employed in clinical studies. This paper reviews current progress towards the development of PET and SPECT probes for GluRs. PMID:25874256

  3. Intrinsic Feature Pose Measurement for Awake Animal SPECT Imaging

    SciTech Connect

    Goddard Jr, James Samuel; Baba, Justin S; Lee, Seung Joon; Weisenberger, A G; Stolin, A; McKisson, J; Smith, M F

    2009-01-01

    New developments have been made in optical motion tracking for awake animal imaging that measures 3D position and orientation (pose) for a single photon emission computed tomography (SPECT) imaging system. Ongoing SPECT imaging research has been directed towards head motion measurement for brain studies in awake, unrestrained mice. In contrast to previous results using external markers, this work extracts and tracks intrinsic features from multiple camera images and computes relative pose from the tracked features over time. Motion tracking thus far has been limited to measuring extrinsic features such as retro-reflective markers applied to the mouse s head. While this approach has been proven to be accurate, the additional animal handling required to attach the markers is undesirable. A significant improvement in the procedure is achieved by measuring the pose of the head without extrinsic markers using only the external surface appearance. This approach is currently being developed with initial results presented here. The intrinsic features measurement extracts discrete, sparse natural features from 2D images such as eyes, nose, mouth and other visible structures. Stereo correspondence between features for a camera pair is determined for calculation of 3D positions. These features are also tracked over time to provide continuity for surface model fitting. Experimental results from live images are presented.

  4. SPECT reconstruction using DCT-induced tight framelet regularization

    NASA Astrophysics Data System (ADS)

    Zhang, Jiahan; Li, Si; Xu, Yuesheng; Schmidtlein, C. R.; Lipson, Edward D.; Feiglin, David H.; Krol, Andrzej

    2015-03-01

    Wavelet transforms have been successfully applied in many fields of image processing. Yet, to our knowledge, they have never been directly incorporated to the objective function in Emission Computed Tomography (ECT) image reconstruction. Our aim has been to investigate if the ℓ1-norm of non-decimated discrete cosine transform (DCT) coefficients of the estimated radiotracer distribution could be effectively used as the regularization term for the penalized-likelihood (PL) reconstruction, where a regularizer is used to enforce the image smoothness in the reconstruction. In this study, the ℓ1-norm of 2D DCT wavelet decomposition was used as a regularization term. The Preconditioned Alternating Projection Algorithm (PAPA), which we proposed in earlier work to solve penalized likelihood (PL) reconstruction with non-differentiable regularizers, was used to solve this optimization problem. The DCT wavelet decompositions were performed on the transaxial reconstructed images. We reconstructed Monte Carlo simulated SPECT data obtained for a numerical phantom with Gaussian blobs as hot lesions and with a warm random lumpy background. Reconstructed images using the proposed method exhibited better noise suppression and improved lesion conspicuity, compared with images reconstructed using expectation maximization (EM) algorithm with Gaussian post filter (GPF). Also, the mean square error (MSE) was smaller, compared with EM-GPF. A critical and challenging aspect of this method was selection of optimal parameters. In summary, our numerical experiments demonstrated that the ℓ1-norm of discrete cosine transform (DCT) wavelet frame transform DCT regularizer shows promise for SPECT image reconstruction using PAPA method.

  5. Quantitative SPECT reconstruction using CT-derived corrections

    NASA Astrophysics Data System (ADS)

    Willowson, Kathy; Bailey, Dale L.; Baldock, Clive

    2008-06-01

    A method for achieving quantitative single-photon emission computed tomography (SPECT) based upon corrections derived from x-ray computed tomography (CT) data is presented. A CT-derived attenuation map is used to perform transmission-dependent scatter correction (TDSC) in conjunction with non-uniform attenuation correction. The original CT data are also utilized to correct for partial volume effects in small volumes of interest. The accuracy of the quantitative technique has been evaluated with phantom experiments and clinical lung ventilation/perfusion SPECT/CT studies. A comparison of calculated values with the known total activities and concentrations in a mixed-material cylindrical phantom, and in liver and cardiac inserts within an anthropomorphic torso phantom, produced accurate results. The total activity in corrected ventilation-subtracted perfusion images was compared to the calibrated injected dose of [99mTc]-MAA (macro-aggregated albumin). The average difference over 12 studies between the known and calculated activities was found to be -1%, with a range of ±7%.

  6. Radiotracers for PET and SPECT studies of neurotransmitter systems

    SciTech Connect

    Fowler, J.S.

    1991-01-01

    The study of neurotransmitter systems is one of the major thrusts in emission tomography today. The current generation of Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) radiotracers examines neurotransmitter properties from a number of different perspectives including their pre and post synaptic sites and the activity of the enzymes which regulate their concentration. Although the dopamine system has been the most extensively investigated, other neurotransmitter systems including the acetylcholine muscarine, serotonin, benzodiazepine, opiate, NMDA and others are also under intensive development. Enzymes involved in the synthesis and regulation of neurotransmitter concentration, for example monoamine oxidase and amino acid decarboxylase has also been probed in vivo. Medical applications range from the study of normal function and the characterization of neurotransmitter activity in neurological and psychiatric diseases and in heart disease and cancer to the study of the binding of therapeutic drugs and substances of abuse. This chapter will provide an overview of the current generation of radiotracers for PET and SPECT studies of neurotransmitter systems including radiotracer design, synthesis localization mechanisms and applications in emission tomography. 60 refs., 1 tab.

  7. Adaptive SPECT imaging with crossed-slit apertures

    PubMed Central

    Durko, Heather L.; Furenlid, Lars R.

    2015-01-01

    Preclinical single-photon emission computed tomography (SPECT) is an essential tool for studying the progression, response to treatment, and physiological changes in small animal models of human disease. The wide range of imaging applications is often limited by the static design of many preclinical SPECT systems. We have developed a prototype imaging system that replaces the standard static pinhole aperture with two sets of movable, keel-edged copper-tungsten blades configured as crossed (skewed) slits. These apertures can be positioned independently between the object and detector, producing a continuum of imaging configurations in which the axial and transaxial magnifications are not constrained to be equal. We incorporated a megapixel silicon double-sided strip detector to permit ultrahigh-resolution imaging. We describe the configuration of the adjustable slit aperture imaging system and discuss its application toward adaptive imaging, and reconstruction techniques using an accurate imaging forward model, a novel geometric calibration technique, and a GPU-based ultra-high-resolution reconstruction code. PMID:26190884

  8. Comparison study of temporal regularization methods for fully 5D reconstruction of cardiac gated dynamic SPECT.

    PubMed

    Niu, Xiaofeng; Yang, Yongyi; King, Michael A

    2012-09-01

    Temporal regularization plays a critical role in cardiac gated dynamic SPECT reconstruction, of which the goal is to obtain an image sequence from a single acquisition which simultaneously shows both cardiac motion and tracer distribution change over the course of imaging (termed 5D). In our recent work, we explored two different approaches for temporal regularization of the dynamic activities in gated dynamic reconstruction without the use of fast camera rotation: one is the dynamic EM (dEM) approach which is imposed on the temporal trend of the time activity of each voxel, and the other is a B-spline modeling approach in which the time activity is regulated by a set of B-spline basis functions. In this work, we extend the B-spline approach to fully 5D reconstruction and conduct a thorough quantitative comparison with the dEM approach. In the evaluation of the reconstruction results, we apply a number of quantitative measures on two major aspects of the reconstructed dynamic images: (1) the accuracy of the reconstructed activity distribution in the myocardium and (2) the ability of the reconstructed dynamic activities to differentiate perfusion defects from normal myocardial wall uptake. These measures include the mean square error (MSE), bias-variance analysis, accuracy of time-activity curves (TAC), contrast-to-noise ratio of a defect, composite kinetic map of the left ventricle wall and perfusion defect detectability with channelized Hotelling observer. In experiments, we simulated cardiac gated imaging with the NURBS-based cardiac-torso phantom and Tc99m-Teboroxime as the imaging agent, where acquisition with the equivalent of only three full camera rotations was used during the imaging period. The results show that both dEM and B-spline 5D could achieve similar overall accuracy in the myocardium in terms of MSE. However, compared to dEM 5D, the B-spline approach could achieve a more accurate reconstruction of the voxel TACs; in particular, B-spline 5D could

  9. Incremental Diagnostic Performance of Combined Parameters in the Detection of Severe Coronary Artery Disease Using Exercise Gated Myocardial Perfusion Imaging

    PubMed Central

    Liu, Chia-Ju; Wu, Yen-Wen; Ko, Kuan-Yin; Chen, Yi-Chieh; Cheng, Mei-Fang; Yen, Ruoh-Fang; Tzen, Kai-Yuan

    2015-01-01

    Purpose Myocardial perfusion imaging (MPI) using gated single-photon emission tomography (gSPECT) may underestimate the severity of coronary artery disease (CAD). This study aimed to evaluate the significance of combined parameters derived from gSPECT, as well as treadmill stress test parameters, in the detection of severe CAD. Methods A total of 211 consecutive patients referred for exercise MPI between June 2011 and June 2013 (who received invasive coronary angiography within six months after MPI) were retrospectively reviewed. Exercise MPI was performed with Bruce protocol and 201Tl injected at peak exercise. Gated SPECT was performed using a cadmium-zinc-telluride camera and processed by QPS/QGS software. Perfusion defect abnormalities such as sum stress score (SSS); sum difference score, algorithm-derived total perfusion deficits, transient ischemic dilatation ratios of end-diastolic volumes and end-systolic volumes, post-stress changes in ejection fraction, and lung/heart ratio (LHR) were calculated. Treadmill parameters, including ST depression (STD) at the 1st and 3rd minutes of recovery stage (1’STD and 3’STD), maximal STD corrected by heart rate increment (ST/HR), heart rate decline in 1st and 3rd minutes of recovery stage, recovery heart rate ratio (HR ratio), systolic and mean blood pressure ratios (SBP ratio and MAP ratio) during recovery phase were recorded. Diagnostic performances of these parameters were analyzed with receiver operating characteristic (ROC) analysis and logistic regression for detection of left main (≥ 50%) or 3-vessel disease (all ≥ 70% luminal stenosis) on invasive angiography. Results Among various MPI and treadmill parameters used for detection of severe CAD, SSS and ST/HR had the highest AUC (0.78, 0.73, p = NS) and best cut-off values (SSS > 6, ST/HR > 17.39 10-2mV/bpm), respectively. By univariate logistic regression, all parameters except 1’HRR, 3’HRR, SBP and MAP ratios increased the odds ratio of severe CAD

  10. Radionuclide imaging of myocardial perfusion and viability in assessment of acute myocardial infarction

    SciTech Connect

    Berman, D.S.; Kiat, H.; Maddahi, J.; Shah, P.K.

    1989-07-18

    Technical advances in radionuclide imaging have important implications for the management of patients with acute myocardial infarction. Single-photon emission computerized tomography with thallium 201 (TI-201) offers greater accuracy than planar imaging in detecting, localizing and sizing myocardial perfusion defects. Use of single-photon emission computerized tomography with TI-201 should allow for a more accurate assessment of prognosis after myocardial infarction. A new radiopharmaceutical, technetium 99-m methoxyisobutyl isonitrile, provides a number of advantages over TI-201, including higher quality images, lack of redistribution, and the ability to assess first-pass ventricular function. Applications of TI-201 and technetium 99-m methoxyisobutyl isonitrile include assessment of arterial patency and myocardial salvage immediately after thrombolytic therapy, detection of resting ischemia after thrombolytic therapy, targeting of subsets of patients for further intervention, and predischarge assessment to predict the future course of patients after an acute myocardial infarction.

  11. Incidence of acute myocardial infarction in patients with exercise-induced silent myocardial ischemia

    SciTech Connect

    Assey, M.E.; Walters, G.L.; Hendrix, G.H.; Carabello, B.A.; Usher, B.W.; Spann, J.F. Jr.

    1987-03-01

    Fifty-five patients with angiographically proved coronary artery disease (CAD) underwent Bruce protocol exercise stress testing with thallium-201 imaging. Twenty-seven patients (group I) showed myocardial hypoperfusion without angina pectoris during stress, which normalized at rest, and 28 patients (group II) had a similar pattern of reversible myocardial hypoperfusion but also had angina during stress. Patients were followed for at least 30 months. Six patients in group I had an acute myocardial infarction (AMI), 3 of whom died, and only 1 patient in group II had an AMI (p = 0.05), and did not die. Silent myocardial ischemia uncovered during exercise stress thallium testing may predispose to subsequent AMI. The presence of silent myocardial ischemia identified in this manner is of prognostic value, independent of angiographic variables such as extent of CAD and left ventricular ejection fraction.

  12. Sequential sup 123 I-IMP-SPECT in acute infantile hemiplegia

    SciTech Connect

    Shirasaka, Y.; Ito, M.; Okuno, T.; Fujii, T.; Mikawa, H. )

    1989-09-01

    Sequential {sup 123}I-N-isopropyl-p-iodoamphetamine (IMP) single-photon emission computed tomography (SPECT) was performed in 2 patients with acute infantile hemiplegia. In both patients, low uptake of IMP was detected in the targeted abnormal hemisphere. The {sup 123}I-IMP-SPECT findings indicative of a pathologic condition persisted even when the clinical findings and electroencephalographic abnormalities improved. Because of its sensitivity, noninvasiveness, and accurate reflection of the cerebral blood flow distribution, {sup 123}I-IMP-SPECT is useful in the examination of acute infantile hemiplegia and in the evaluation of prognosis.

  13. Unusual Adrenal and Brain Metastases From Follicular Thyroid Carcinoma Revealed by 131I SPECT/CT.

    PubMed

    Zhao, Zhen; Shen, Guo-hua; Liu, Bin; Kuang, An-ren

    2016-01-01

    The adrenal metastasis from differentiated thyroid carcinoma is uncommon. Metastatic involvement of both adrenal and brain in the same patient from differentiated thyroid carcinoma is rare. Here, we described an unusual case with iodine-avid lung, bone, adrenal, liver, and brain metastases from follicular thyroid carcinoma confirmed by 131I SPECT/CT. The utilization of SPECT/CT in thyroid cancer patients can detect the presence of metastases and also exclude potential false-positive lesions. Our case demonstrates that SPECT/CT is helpful in localizing and confirming metastatic lesions from differentiated thyroid carcinoma in rare and unusual sites. PMID:26018699

  14. Ranolazine Therapy Reduces Non-ST-Segment-Elevation Myocardial Infarction and Unstable Angina in Coronary Disease Patients with Angina.

    PubMed

    Murray, Gary L; Colombo, Joseph

    2016-09-01

    High sympathetic tone and cardiac autonomic neuropathy (CAN) are associated with major adverse cardiac events (MACE). We have shown ranolazine (RAN) improves autonomic function. RAN was introduced to 51 successive anginal CD patients (RANCD). A control group of 54 successive nonanginal CD patients (NORANCD) continued baseline therapy. Mean study duration was 6.1 years, which included semi-annual autonomic function measures (ANX 3.0, ANSAR Medical Technologies, Inc., Philadelphia, PA) and yearly myocardial perfusion SPECT studies (MPI). MACE were experienced by 29% RANCD patients versus 46% NORANCD patients (p = 0.0105). The patients from both groups with abnormal parasympathetic and sympathetic (P&S) measures and MACE totaled 52 of those patients with MACE versus 17% of those patients without MACE (p = 0.0274). Abnormal MPI was demonstrated in 35% of those with abnormal (P&S) measures and MACE versus 12% without MACE. Sympathovagal balance (SB) was lower, indicating higher, relative parasympathetic tone (known to be cardioprotective) in the RANCD group. Acute coronary syndromes occurred 4.5 times as often in NORANCD patients. High SB occur more frequently than abnormal MPI in CD patients experiencing MACE. In addition to increased myocardial blood flow as its proposed mechanism of angina relief, RAN improves P&S measures, a potentially new mechanism whereby RAN improves outcomes. PMID:27574382

  15. The Influence of Autologous Bone Marrow Stem Cell Transplantation on Matrix Metalloproteinases in Patients Treated for Acute ST-Elevation Myocardial Infarction

    PubMed Central

    Furenes, Eline Bredal; Opstad, Trine Baur; Solheim, Svein; Lunde, Ketil; Arnesen, Harald; Seljeflot, Ingebjørg

    2014-01-01

    Background. Matrix metalloproteinase-9 (MMP-9), regulated by tissue inhibitor of metalloproteinase-9 (TIMP-1) and the extracellular matrix metalloproteinase inducer (EMMPRIN), contributes to plaque instability. Autologous stem cells from bone marrow (mBMC) treatment are suggested to reduce myocardial damage; however, limited data exists on the influence of mBMC on MMPs. Aim. We investigated the influence of mBMC on circulating levels of MMP-9, TIMP-1, and EMMPRIN at different time points in patients included in the randomized Autologous Stem-Cell Transplantation in Acute Myocardial Infarction (ASTAMI) trial (n = 100). Gene expression analyses were additionally performed. Results. After 2-3 weeks we observed a more pronounced increase in MMP-9 levels in the mBMC group, compared to controls (P = 0.030), whereas EMMPRIN levels were reduced from baseline to 2-3 weeks and 3 months in both groups (P < 0.0001). Gene expression of both MMP-9 and EMMPRIN was reduced from baseline to 3 months. MMP-9 and EMMPRIN were significantly correlated to myocardial injury (CK: P = 0.005 and P < 0.001, resp.) and infarct size (SPECT: P = 0.018 and P = 0.008, resp.). Conclusion. The results indicate that the regulation of metalloproteinases is important during AMI, however, limited influenced by mBMC. PMID:25294955

  16. Parathyroid scintigraphy in patients with primary hyperparathyroidism: 99mTc sestamibi SPECT and SPECT/CT.

    PubMed

    Eslamy, Hedieh K; Ziessman, Harvey A

    2008-01-01

    The clinical diagnosis of primary hyperparathyroidism is based largely on serum laboratory test results, as patients often are asymptomatic. Surgery, often with bilateral exploration of the neck, has been considered the definitive treatment for symptomatic disease. However, given that approximately 90% of cases are due to a single parathyroid adenoma, a better treatment may be the selective surgical excision of the hyperfunctioning parathyroid gland after its preoperative identification and localization at radiologic imaging. Scintigraphy and ultrasonography are the imaging modalities most often used for preoperative localization. Various scintigraphic protocols may be used in the clinical setting: Single-phase dual-isotope subtraction imaging, dual-phase single-isotope imaging, or a combination of the two may be used to obtain planar or tomographic views. Single photon emission computed tomography (SPECT) with the use of technetium-99m ((99m)Tc) sestamibi as the radiotracer, especially when combined with x-ray-based computed tomography (CT), is particularly helpful for preoperative localization: The three-dimensional functional information from SPECT is fused with the anatomic information obtained from CT. In addition, knowledge of the anatomy and embryologic development of the parathyroid glands and the pathophysiology of primary hyperparathyroidism aid in the identification and localization of hyperfunctioning glands. PMID:18794320

  17. Evaluation of 99mTcN-MPO as a New Myocardial Perfusion Imaging Agent in Normal Dogs and in an Acute Myocardial Infarction Canine Model: Comparison with 99mTc-Sestamibi

    PubMed Central

    Bu, Lihong; Li, Renfei; Jin, Zhongnan; Wen, Xiaofei; Liu, Shuang; Yang, Baofeng; Shen, Baozhong; Chen, Xiaoyuan

    2010-01-01

    Purpose 99mTcN-MPO ([99mTcN(mpo)(PNP5)]+: mpo=2-mercaptopyridine oxide and PNP5=N-ethoxyethyl-N,N-bis[2-(bis(3-methoxypropyl)phosphino)ethyl]amine) is a cationic 99mTc-nitrido complex, which has favorable biodistribution and myocardial uptake with rapid liver clearance in Sprague Dawley rats. The objective of this study was to compare the biodistribution and pharmacokinetics of 99mTcN-MPO and 99mTc-Sestamibi in normal dogs, and to evaluate the potential of 99mTcN-MPO as a myocardial perfusion agent in canines with acute myocardial infarction. Methods Five normal mongrel dogs were injected intravenously with 99mTcN-MPO. Venous blood samples were collected via a femoral vein catheter at 0.5, 1, 2, 3, 4, 5, 10, 20, 30, 40, 60, and 90 min post-injection (p.i.). Anterior-posterior planar images were acquired by γ-camera at 10, 20, 30, 60, 90, and 120 min p.i. Regions of interest (ROIs) were drawn around the heart, liver, and lungs. The heart/liver and heart/lung ratios were calculated by dividing the mean counts in heart ROI by the mean counts in the liver and lung ROI, respectively. For comparison, 99mTc-sestamibi was also evaluated in the same five dogs. The interval period between the two examinations was 1 week to eliminate possible interference between these two radiotracers. In addition, single positron emission computed tomography (SPECT) images in the canine infarct model were collected 24 h after myocardial infarction at 30 and 60 min after the administration of 99mTcN-MPO (n=4) or 99mTc-Sestamibi (n=4). Results It was found that 99mTcN-MPO and 99mTc-Sestamibi displayed very similar blood clearance characteristics during the first 90 min p.i. Both 99mTcN-MPO and 99mTc-Sestamibi had a rapid blood clearance with less than 50% of initial radioactivity remaining at 1 min and less than 5% at 30 min p.i. 99mTcN-MPO and 99mTc-Sestamibi both showed good heart/lung contrast. The heart/liver ratio of 99mTcN-MPO increased with time (0.53±0.06 at 10 min, 0.90±0.062 at

  18. Clinical decision making with myocardial perfusion imaging in patients with known or suspected coronary artery disease.

    PubMed

    Cremer, Paul; Hachamovitch, Rory; Tamarappoo, Balaji

    2014-07-01

    Myocardial perfusion imaging (MPI) to diagnose coronary artery disease (CAD) is best performed in patients with intermediate pretest likelihood of disease; unfortunately, pretest likelihood is often overestimated, resulting in the inappropriate use of perfusion imaging. A good functional capacity often predicts low risk, and MPI for diagnosing CAD should be reserved for individuals with poor exercise capacity, abnormal resting electrocardiography, or an intermediate or high probability of CAD. With respect to anatomy-based testing, coronary CT angiography has a good negative predictive value, but stenosis severity correlates poorly with ischemia. Therefore decision making with respect to revascularization may be limited when a purely noninvasive anatomical test is used. Regarding perfusion imaging, the diagnostic accuracies of SPECT, PET, and cardiac magnetic resonance are similar, though fewer studies are available with cardiac magnetic resonance. PET coronary flow reserve may offer a negative predictive value sufficiently high to exclude severe CAD such that patients with mild to moderate reversible perfusion defects can forego invasive angiography. In addition, combined anatomical and perfusion-based imaging may eventually offer a definitive evaluation for diagnosing CAD, even in higher risk patients. Any remarkable findings on single-photon emission computed tomography and PET MPI studies are valuable for prognostication. Furthermore, assessment of myocardial blood flow with PET is particularly powerful for prognostication as it reflects the end result of many processes that lead to atherosclerosis. Decision making with respect to revascularization is limited for cardiac MRI and PET MPI. In contrast, retrospective radionuclide studies have identified an ischemic threshold, but randomized trials are needed. In patients with at least moderately reduced left ventricular systolic function, viable myocardium as assessed by PET or MRI, appears to identify patients

  19. Immunological results in myocardial diseases.

    PubMed Central

    Bolte, H. D.; Schultheiss, P.

    1978-01-01

    Immunological studies have shown new diagnostically important changes in alcoholic and viral myocarditis, as well as in congestive cardiomyopathy. Increased heart size correlated with the degree of congestive heart failure, as well as with negative immunofluorescence and an increased IgA concentration in the serum. These findings may serve as a diagnostic aid in patients with myocardial disease due to alcohol abuse. Viral heart disease is characterized by a variety of symptoms and nuclear antibodies (IgM) can be of help in the differential diagnosis. Heart muscle tissue of patients with congestive cardiomyopathy preferentially binds IgG and IgA. In addition to the other changes these findings are of diagnostic importance. It seems likely that results similar to those obtained for humoral antibodies in congestive cardiomyopathy will apply in the correlation of the haemodynamic status of the patients. The pathophysiological implication of these findings is not clear at present, but the evolution of congestive cardiomyopathy appears to be associated with binding of immunoglobulin to the myocardium, as well as with humoral antiheart antibodies. PMID:704517

  20. [Occupational stress and myocardial infarction].

    PubMed

    Consoli, Silla M

    2015-01-01

    Besides the best-known role of depressed mood, occupational stress deserves to be taken as a coronary risk factor. There are two basic models to define occupational stress: Karasek's model (high job psychological demands associated with low decision latitude, or even low social support at work) and Siegrist's model (imbalance between efforts and rewards received). The combination of the two models better reflects the coronary risk than each model alone. Occupational stress appears both as a risk factor and a prognostic factor after the occurrence of myocardial infarction. The relevance of the models is best in men or in younger age subjects. In women, role conflicts (occupational/domestic), the existence of excessive "intrinsic" efforts (job over investment) and association with marital stress provide more specific information. Burnout, particularly among health professionals, and bullying at work are also linked to cardiovascular risk. Occupational stress is a collective indicator of health at work, valuable to the employer. At an individual level, it can lead to therapeutic preventive approaches. PMID:26150284

  1. Molecular genetics of myocardial infarction

    PubMed Central

    Ichihara, Sahoko; Nishida, Tamotsu

    2008-01-01

    Abstract Myocardial infarction (MI) is an important clinical problem because of its large contribution to mortality. The main causal and treatable risk factors for MI include hypertension, hypercholesterolemia or dyslipidemia, diabetes mellitus, and smoking. In addition to these risk factors, recent studies have shown the importance of genetic factors and interactions between multiple genes and environmental factors. Disease prevention is an important strategy for reducing the overall burden of MI, with the identification of markers for disease risk being key both for risk prediction and for potential intervention to lower the chance of future events. Although genetic linkage analyses of families and sib-pairs as well as candidate gene and genome-wide association studies have implicated several loci and candidate genes in predisposition to coronary heart disease (CHD) or MI, the genes that contribute to genetic susceptibility to these conditions remain to be identified definitively. In this review, we summarize both candidate loci for CHD or MI identified by linkage analyses and candidate genes examined by association studies. We also review in more detail studies that have revealed the association with MI or CHD of polymorphisms in MTHFR, LPL, and APOE by the candidate gene approach and those in LTA and at chromosomal region 9p21.3 by genome-wide scans. Such studies may provide insight into the function of implicated genes as well as into the role of genetic factors in the development of CHD and MI. PMID:18704761

  2. Echocardiographic assessment of myocardial ischemia

    PubMed Central

    Dworrak, Birgit; Sanchis-Gomar, Fabian; Lucia, Alejandro; Buck, Thomas; Erbel, Raimund

    2016-01-01

    Over the last 60 years, echocardiography has emerged as a dominant and indispensable technique for the detection and assessment of coronary heart disease (CHD). In this review, we will describe and discuss this powerful tool of cardiology, especially in the hands of an experienced user, with a focus on myocardial ischemia. Technical development is still on-going, and various new ultrasound techniques have been established in the field of echocardiography in the last several years, including tissue Doppler imaging (TDI), contrast echocardiography, three-dimensional echocardiography (3DE), and speckle tracking echocardiography (i.e., strain/strain rate-echocardiography). High-end equipment with harmonic imaging, high frame rates and the opportunity to adjust mechanical indices has improved imaging quality. Like all new techniques, these techniques must first be subjected to comprehensive scientific assessment, and appropriate training that accounts for physical and physiological limits should be provided. These limits will constantly be redefined as echocardiographic techniques continue to change, which will present new challenges for the further development of ultrasound technology. PMID:27500160

  3. Echocardiographic assessment of myocardial ischemia.

    PubMed

    Leischik, Roman; Dworrak, Birgit; Sanchis-Gomar, Fabian; Lucia, Alejandro; Buck, Thomas; Erbel, Raimund

    2016-07-01

    Over the last 60 years, echocardiography has emerged as a dominant and indispensable technique for the detection and assessment of coronary heart disease (CHD). In this review, we will describe and discuss this powerful tool of cardiology, especially in the hands of an experienced user, with a focus on myocardial ischemia. Technical development is still on-going, and various new ultrasound techniques have been established in the field of echocardiography in the last several years, including tissue Doppler imaging (TDI), contrast echocardiography, three-dimensional echocardiography (3DE), and speckle tracking echocardiography (i.e., strain/strain rate-echocardiography). High-end equipment with harmonic imaging, high frame rates and the opportunity to adjust mechanical indices has improved imaging quality. Like all new techniques, these techniques must first be subjected to comprehensive scientific assessment, and appropriate training that accounts for physical and physiological limits should be provided. These limits will constantly be redefined as echocardiographic techniques continue to change, which will present new challenges for the further development of ultrasound technology. PMID:27500160

  4. A preliminary feasibility study of simultaneous dual-isotope imaging with a solid-state dedicated cardiac camera for evaluating myocardial perfusion and fatty acid metabolism.

    PubMed

    Ko, Toshiyuki; Utanohara, Yuko; Suzuki, Yasuhiro; Kurihara, Makiko; Iguchi, Nobuo; Umemura, Jun; Sumiyoshi, Tetsuya; Tomoike, Hitonobu

    2016-01-01

    Simultaneous dual-isotope SPECT imaging with 201Tl and (123)I-β-methyl-p-iodophenylpentadecanoic acid (BMIPP) is used to study the perfusion-metabolism mismatch. It predicts post-ischemic functional recovery by detecting stunned myocardium. On the other hand, (99m)Tc-MIBI is another radioisotope widely used in myocardial perfusion imaging because of its better image quality and lower radiation exposure than 201Tl. However, since the photopeak energies of (99m)Tc and (123)I are very similar, crosstalk hampers the simultaneous use of these two radioisotopes. To overcome this problem, we conducted simultaneous dual-isotope imaging study using the D-SPECT scanner (Spectrum-Dynamics, Israel) which has a novel detector design and excellent energy resolution. We first conducted a basic experiment using cardiac phantom to simulate the condition of normal perfusion and impaired fatty acid metabolism. Subsequently, we prospectively recruited 30 consecutive patients who underwent successful percutaneous coronary intervention for acute myocardial infarction, and performed (99m)Tc-MIBI/(123)I-BMIPP dual-isotope imaging within 5 days after reperfusion. Images were interpreted by two experienced cardiovascular radiologists to identify the infarcted and stunned areas based on the coronary artery territories. As a result, cardiac phantom experiment revealed no significant crosstalk between (99m)Tc and (123)I. In the subsequent clinical study, (99m)Tc-MIBI/(123)I-BMIPP dual-isotope imaging in all participant yielded excellent image quality and detected infarcted and stunned areas correctly when compared with coronary angiographic findings. Furthermore, we were able to reduce radiation exposure to significantly approximately one-eighth. In conclusion, we successfully demonstrated the practical application of simultaneous assessment of myocardial perfusion and fatty acid metabolism by (99m)Tc-MIBI and (123)I-BMIPP using a D-SPECT cardiac scanner. Compared with conventional (201)Tl

  5. Myocardial infarction size: measurement and modification

    PubMed Central

    Cairns, John A.

    1977-01-01

    The majority of in-hospital deaths from acute myocardial infarction occur as a result of the “power failure” syndrome (severe congestive heart failure and cardiogenic shock), which results from extensive loss of myocardium. The death of myocardial cells is sequential over many hours. Surrounding the central zone of necrosis in an acute myocardial infarction is a zone of ischemic myocardium whose fate might be altered by interventions during the early phase of the infarction. ST-segment mapping, serial measurement of the serum concentration of creatine phosphokinase and myocardial imaging by means of radionuclides are being developed for the noninvasive assessment of infarct size in animals and humans. A number of interventions appear to limit infarct size in animals. There have been relatively few studies in humans to date, but preliminary results suggest that infarct size might be limited by certain interventions. The research has provided important practical benefits in terms of understanding the course of acute myocardial infarction and the potential effects of conventional therapies. For the present, interventions designed to limit infarct size remain in the realm of clinical research; routine clinical use would be inappropriate. PMID:69481

  6. Contemporary perspective on endogenous myocardial regeneration

    PubMed Central

    Milasinovic, Dejan; Mohl, Werner

    2015-01-01

    Considering the complex nature of the adult heart, it is no wonder that innate regenerative processes, while maintaining adequate cardiac function, fall short in myocardial jeopardy. In spite of these enchaining limitations, cardiac rejuvenation occurs as well as restricted regeneration. In this review, the background as well as potential mechanisms of endogenous myocardial regeneration are summarized. We present and analyze the available evidence in three subsequent steps. First, we examine the experimental research data that provide insights into the mechanisms and origins of the replicating cardiac myocytes, including cell populations referred to as cardiac progenitor cells (i.e., c-kit+ cells). Second, we describe the role of clinical settings such as acute or chronic myocardial ischemia, as initiators of pathways of endogenous myocardial regeneration. Third, the hitherto conducted clinical studies that examined different approaches of initiating endogenous myocardial regeneration in failing human hearts are analyzed. In conclusion, we present the evidence in support of the notion that regaining cardiac function beyond cellular replacement of dysfunctional myocardium via initiation of innate regenerative pathways could create a new perspective and a paradigm change in heart failure therapeutics. Reinitiating cardiac morphogenesis by reintroducing developmental pathways in the adult failing heart might provide a feasible way of tissue regeneration. Based on our hypothesis “embryonic recall”, we present first supporting evidence on regenerative impulses in the myocardium, as induced by developmental processes. PMID:26131310

  7. SPECT imaging evaluation in movement disorders: far beyond visual assessment.

    PubMed

    Badiavas, Kosmas; Molyvda, Elisavet; Iakovou, Ioannis; Tsolaki, Magdalini; Psarrakos, Kyriakos; Karatzas, Nikolaos

    2011-04-01

    Single photon emission computed tomography (SPECT) imaging with (123)I-FP-CIT is of great value in differentiating patients suffering from Parkinson's disease (PD) from those suffering from essential tremor (ET). Moreover, SPECT with (123)I-IBZM can differentiate PD from Parkinson's "plus" syndromes. Diagnosis is still mainly based on experienced observers' visual assessment of the resulting images while many quantitative methods have been developed in order to assist diagnosis since the early days of neuroimaging. The aim of this work is to attempt to categorize, briefly present and comment on a number of semi-quantification methods used in nuclear medicine neuroimaging. Various arithmetic indices have been introduced with region of interest (ROI) manual drawing methods giving their place to automated procedures, while advancing computer technology has allowed automated image registration, fusion and segmentation to bring quantification closer to the final diagnosis based on the whole of the patient's examinations results, clinical condition and response to therapy. The search for absolute quantification has passed through neuroreceptor quantification models, which are invasive methods that involve tracer kinetic modelling and arterial blood sampling, a practice that is not commonly used in a clinical environment. On the other hand, semi-quantification methods relying on computers and dedicated software try to elicit numerical information out of SPECT images. The application of semi-quantification methods aims at separating the different patient categories solving the main problem of finding the uptake in the structures of interest. The semi-quantification methods which were studied fall roughly into three categories, which are described as classic methods, advanced automated methods and pixel-based statistical analysis methods. All these methods can be further divided into various subcategories. The plethora of the existing semi-quantitative methods reinforces

  8. Two-dimensional filtering of SPECT images using the Metz and Wiener filters

    SciTech Connect

    King, M.A.; Schwinger, R.B.; Doherty, P.W.; Penney, B.C.

    1984-11-01

    Two-dimensional filtering, both before and after reconstruction, has been applied to the processing of single photon emission computerized tomographic (SPECT) images. The filters investigated were the count-dependent Metz filter and Wiener filter, both of which automatically adapt to the image being processed. Using a SPECT phantom, with images reconstructed with these filters rather than the ramp, the authors observed a statistically signficant increase in the image contrast for solid Plexiglas spheres, and significant decrease in the percent fractional standard deviation of counts in a region of uniform activity. The adaptability of these filters is demonstrated by a comparison of SPECT acquisition of the phantom at two different count levels. An example of the application to clinical studies is presented. Two-dimensional digital image restoration with these techniques can produce a significant increase in SPECT image quality, with a small cost in processing time when these techniques are implemented on an array processor.

  9. SPECT assay of radiolabeled monoclonal antibodies. Comprehensive progress report, September 1989--February 1992

    SciTech Connect

    Jaszczak, R.J.

    1992-02-01

    The long-term goal of this research project is to develop methods to improve the utility of single photon emission computed tomography (SPECI) to quantify the biodistribution of monoclonal antibodies (MoAbs) labeled with clinically relevant radionuclides ({sup 123}I, {sup 131}I, and {sup 111}In) and with another radionuclide,{sup 211}At, recently used in therapy. We describe here our progress in developing quantitative SPECT methodology for {sup 111}In and {sup 123}I. We have focused our recent research thrusts on the following aspects of SPECT: (1) The development of improved SPECT hardware, such as improved acquisition geometries. (2) The development of better reconstruction methods that provide accurate compensation for the physical factors that affect SPECT quantification. (3) The application of carefully designed simulations and experiments to validate our hardware and software approaches.

  10. Clinical application of SPECT in adrenal imaging with iodine-131 6 beta-iodomethyl-19-norcholesterol

    SciTech Connect

    Ishimura, J.; Kawanaka, M.; Fukuchi, M.

    1989-04-01

    Forty-one patients with or without adrenocortical disorders were studied to evaluate the clinical usefulness of SPECT in adrenal imaging with I-131 Adosterol. In the SPECT images from this study, all glands with either normally functioning or hyperfunctioning adrenal cortices could be detected, while those glands with hypofunctioning adrenal cortices could not be detected. Particularly in transaxial and sagittal slices, the adrenal gland was identified posteriorly and was clearly distinguished from the gallbladder. In preliminary results using SPECT by a standard method, uptake in 68 detectable glands ranged from 1.7% to 4.9% in four glands with Cushing's syndrome, from 1.1% to 1.3% in seven glands with primary aldosteronism, and were distributed below 1.0% in the remaining glands with normally functioning adrenal cortices. These data show that it is possible to evaluate the adrenocortical functioning status simply by analyzing the SPECT images of the adrenal.

  11. Choroidal Metastasis of Papillary Thyroid Carcinoma Demonstrated on SPECT-CT.

    PubMed

    Torun, Nese; Reyhan, Mehmet; Yapar, Ali Fuat; Karatas, Muge

    2016-05-01

    We report a 68-year-old woman with papillary thyroid carcinoma metastasizing to choroid. The choroid metastasis was diagnosed with SPECT-CT and then was treated with high-dose radioactive iodine therapy. PMID:26825205

  12. Depression Increases Sympathetic Activity and Exacerbates Myocardial Remodeling after Myocardial Infarction: Evidence from an Animal Experiment

    PubMed Central

    Liu, Tao; Yuan, Xiaoran; Ruan, Bing; Sun, Lifang; Tang, Yanhong; Yang, Bo; Hu, Dan; Huang, Congxin

    2014-01-01

    Depression is an independent risk factor for cardiovascular events and mortality in patients with myocardial infarction (MI). Excessive sympathetic activation and serious myocardial remodeling may contribute to this association. The aim of this study was to discuss the effect of depression on sympathetic activity and myocardial remodeling after MI. Wild-type (WT) rats were divided into a sham group (Sham), a myocardial infarction group (MI), a depression group (D), and a myocardial infarction plus depression group (MI+D). Compared with controls, the MI+D animals displayed depression-like behaviors and attenuated body weight gain. The evaluation of sympathetic activity showed an increased level in plasma concentrations of epinephrine and norepinephrine and higher expression of myocardial tyrosine hydroxylase in the MI+D group than the control groups (p<0.05 for all). Cardiac function and morphologic analyses revealed a decreased fractional shortening accompanied by increased left ventricular dimensions, thinning myocardium wall, and reduced collagen repair in