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Sample records for detection emission tomography

  1. Cerebrospinal fluid analysis detects cerebral amyloid-β accumulation earlier than positron emission tomography.

    PubMed

    Palmqvist, Sebastian; Mattsson, Niklas; Hansson, Oskar

    2016-04-01

    Cerebral accumulation of amyloid-β is thought to be the starting mechanism in Alzheimer's disease. Amyloid-β can be detected by analysis of cerebrospinal fluid amyloid-β42 or amyloid positron emission tomography, but it is unknown if any of the methods can identify an abnormal amyloid accumulation prior to the other. Our aim was to determine whether cerebrospinal fluid amyloid-β42 change before amyloid PET during preclinical stages of Alzheimer's disease. We included 437 non-demented subjects from the prospective, longitudinal Alzheimer's Disease Neuroimaging Initiative (ADNI) study. All underwent (18)F-florbetapir positron emission tomography and cerebrospinal fluid amyloid-β42 analysis at baseline and at least one additional positron emission tomography after a mean follow-up of 2.1 years (range 1.1-4.4 years). Group classifications were based on normal and abnormal cerebrospinal fluid and positron emission tomography results at baseline. We found that cases with isolated abnormal cerebrospinal fluid amyloid-β and normal positron emission tomography at baseline accumulated amyloid with a mean rate of 1.2%/year, which was similar to the rate in cases with both abnormal cerebrospinal fluid and positron emission tomography (1.2%/year, P = 0.86). The mean accumulation rate of those with isolated abnormal cerebrospinal fluid was more than three times that of those with both normal cerebrospinal fluid and positron emission tomography (0.35%/year, P = 0.018). The group differences were similar when analysing yearly change in standardized uptake value ratio of florbetapir instead of percentage change. Those with both abnormal cerebrospinal fluid and positron emission tomography deteriorated more in memory and hippocampal volume compared with the other groups (P < 0.001), indicating that they were closer to Alzheimer's disease dementia. The results were replicated after adjustments of different factors and when using different cut-offs for amyloid-β abnormality

  2. The accuracy of positron emission tomography in the detection of posttransplant lymphoproliferative disorder.

    PubMed

    Dierickx, Daan; Tousseyn, Thomas; Requilé, Annelies; Verscuren, Raf; Sagaert, Xavier; Morscio, Julie; Wlodarska, Iwona; Herreman, An; Kuypers, Dirk; Van Cleemput, Johan; Nevens, Frederik; Dupont, Lieven; Uyttebroeck, Anne; Pirenne, Jacques; De Wolf-Peeters, Christiane; Verhoef, Gregor; Brepoels, Lieselot; Gheysens, Olivier

    2013-05-01

    We investigated sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-fluorodeoxyglucose-positron emission tomography in 170 cases with suspected or biopsy-proven posttransplant lymphoproliferative disorder. All solid organ and hematopoietic stem cell transplant recipients who underwent an 18F-fluorodeoxyglucose-positron emission tomography scan between 2003 and 2010 in our center for the indication posttransplant lymphoproliferative disorder, were retrospectively reviewed and results were compared with tissue biopsy whenever possible. One hundred and seventy positron emission tomography scans in 150 patients were eligible for evaluation. In 45 cases, the patient had a biopsy-confirmed posttransplant lymphoproliferative disorder before positron emission tomography scanning and positron emission tomography was performed for staging purposes. In the remaining 125 cases, positron emission tomography was performed to differentiate between posttransplant lymphoproliferative disorder and other diseases. 18F-fluorodeoxyglucose-uptake was quantitatively expressed by calculation of maximum and mean standardized uptake value in the most intense lesion or, in the absence of attenuation corrected positron emission tomography scans, by comparing uptake in target lesion to liver and mediastinal uptake. We found an overall sensitivity of 89%, specificity of 89%, positive predictive value of 91% and negative predictive value of 87% for posttransplant lymphoproliferative disorder detection by 18F-fluorodeoxyglucose-positron emission tomography. In a subanalysis of the 125 scans performed for differentiating posttransplant lymphoproliferative disorder from other diseases, sensitivity, specificity, positive predictive value and negative predictive value were 90%, 89%, 85% and 93%, respectively. 18F-fluorodeoxyglucose-uptake in posttransplant lymphoproliferative disorder was generally high with a median mean and maximum standardized uptake

  3. The accuracy of positron emission tomography in the detection of posttransplant lymphoproliferative disorder

    PubMed Central

    Dierickx, Daan; Tousseyn, Thomas; Requilé, Annelies; Verscuren, Raf; Sagaert, Xavier; Morscio, Julie; Wlodarska, Iwona; Herreman, An; Kuypers, Dirk; Van Cleemput, Johan; Nevens, Frederik; Dupont, Lieven; Uyttebroeck, Anne; Pirenne, Jacques; De Wolf-Peeters, Christiane; Verhoef, Gregor; Brepoels, Lieselot; Gheysens, Olivier

    2013-01-01

    We investigated sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-fluorodeoxyglucose-positron emission tomography in 170 cases with suspected or biopsy-proven posttransplant lymphoproliferative disorder. All solid organ and hematopoietic stem cell transplant recipients who underwent an 18F-fluorodeoxyglucose-positron emission tomography scan between 2003 and 2010 in our center for the indication posttransplant lymphoproliferative disorder, were retrospectively reviewed and results were compared with tissue biopsy whenever possible. One hundred and seventy positron emission tomography scans in 150 patients were eligible for evaluation. In 45 cases, the patient had a biopsy-confirmed posttransplant lymphoproliferative disorder before positron emission tomography scanning and positron emission tomography was performed for staging purposes. In the remaining 125 cases, positron emission tomography was performed to differentiate between posttransplant lymphoproliferative disorder and other diseases. 18F-fluorodeoxyglucose-uptake was quantitatively expressed by calculation of maximum and mean standardized uptake value in the most intense lesion or, in the absence of attenuation corrected positron emission tomography scans, by comparing uptake in target lesion to liver and mediastinal uptake. We found an overall sensitivity of 89%, specificity of 89%, positive predictive value of 91% and negative predictive value of 87% for posttransplant lymphoproliferative disorder detection by 18F-fluorodeoxyglucose-positron emission tomography. In a subanalysis of the 125 scans performed for differentiating posttransplant lymphoproliferative disorder from other diseases, sensitivity, specificity, positive predictive value and negative predictive value were 90%, 89%, 85% and 93%, respectively. 18F-fluorodeoxyglucose-uptake in posttransplant lymphoproliferative disorder was generally high with a median mean and maximum standardized uptake

  4. Extramedullary Plasmacytoma of the Gallbladder Detected on Fluorine 18-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

    PubMed Central

    Fakhri, Asif Ali; Rodrigue, Paul David; Fakhri, Amena Fatima

    2016-01-01

    Extramedullary plasmacytoma is rare in patients with diagnosed multiple myeloma. Soft tissue plasmacytoma of the gallbladder is particularly uncommon and has been described in only a handful of cases. Diagnosis of gallbladder plasmacytoma with fluorine 18-fluorodeoxyglucose (F18-FDG) positron emission tomography/computed tomography (PET/CT) has not previously been reported. We present a 65-year-old female with a history of multiple myeloma who underwent a restaging F18-FDG-PET/CT which showed a focal area of hypermetabolic activity, corresponding to a nodular lesion within the posterior gallbladder wall. The patient underwent successful cholecystectomy, with surgical pathology revealing gallbladder plasmacytoma. A follow-up scan was negative for active malignancy. This is a novel case of gallbladder plasmacytoma diagnosed on whole-body F18-FDG PET/CT – thus demonstrating the clinical value of this imaging modality in staging, restaging, and surveillance for patients with multiple myeloma. PMID:27761300

  5. Improved detection of myocardial infarction by emission computed tomography with thallium-201. Relation to infarct size.

    PubMed Central

    Tamaki, S; Kambara, H; Kadota, K; Suzuki, Y; Nohara, R; Kawai, C; Tamaki, N; Torizuka, K

    1984-01-01

    Emission computed tomography with thallium-201 was compared with planar imaging in its ability to detect myocardial infarctions of various sizes four weeks after the onset. Tomography was performed after planar imaging at rest in 160 patients with a first myocardial infarction, in whom infarct size was prospectively estimated by the peak value of creatine kinase activity at the time of the acute episode and in 39 patients without infarction. The planar images and the transaxial, short axial, and long axial tomograms were interpreted qualitatively. Tomography was significantly more sensitive than planar imaging in detecting anterior (87% v 96%), inferior (73% v 97%), and non-transmural (47% v 87%) infarcts. The increased sensitivity was confined to detecting small infarcts as assessed by the peak creatine kinase value (44% v 89% when peak creatine kinase activity was less than or equal to 1000 IU/l). The overall sensitivity was 96% for tomography and 78% for planar imaging. The specificity was similar (92%) with the two techniques. Thus emission computed tomography can improve the detection rate of small infarcts that cannot be identified on planar images, by showing the three dimensional distribution of thallium-201, and increases the diagnostic value of thallium-201 scintigraphy. Images PMID:6334533

  6. Cerebrospinal fluid analysis detects cerebral amyloid-β accumulation earlier than positron emission tomography

    PubMed Central

    Mattsson, Niklas

    2016-01-01

    See Rabinovici (doi:10.1093/brain/aww025) for a scientific commentary on this article. Cerebral accumulation of amyloid-β is thought to be the starting mechanism in Alzheimer’s disease. Amyloid-β can be detected by analysis of cerebrospinal fluid amyloid-β42 or amyloid positron emission tomography, but it is unknown if any of the methods can identify an abnormal amyloid accumulation prior to the other. Our aim was to determine whether cerebrospinal fluid amyloid-β42 change before amyloid PET during preclinical stages of Alzheimer’s disease. We included 437 non-demented subjects from the prospective, longitudinal Alzheimer’s Disease Neuroimaging Initiative (ADNI) study. All underwent 18F-florbetapir positron emission tomography and cerebrospinal fluid amyloid-β42 analysis at baseline and at least one additional positron emission tomography after a mean follow-up of 2.1 years (range 1.1–4.4 years). Group classifications were based on normal and abnormal cerebrospinal fluid and positron emission tomography results at baseline. We found that cases with isolated abnormal cerebrospinal fluid amyloid-β and normal positron emission tomography at baseline accumulated amyloid with a mean rate of 1.2%/year, which was similar to the rate in cases with both abnormal cerebrospinal fluid and positron emission tomography (1.2%/year, P = 0.86). The mean accumulation rate of those with isolated abnormal cerebrospinal fluid was more than three times that of those with both normal cerebrospinal fluid and positron emission tomography (0.35%/year, P = 0.018). The group differences were similar when analysing yearly change in standardized uptake value ratio of florbetapir instead of percentage change. Those with both abnormal cerebrospinal fluid and positron emission tomography deteriorated more in memory and hippocampal volume compared with the other groups (P < 0.001), indicating that they were closer to Alzheimer’s disease dementia. The results were replicated after

  7. Distant metastasis of prostate cancer: early detection of recurrent tumor with dual-phase carbon-11 choline positron emission tomography/computed tomography in two cases.

    PubMed

    Maeda, Tetsuo; Tateishi, Ukihide; Komiyama, Motokiyo; Fujimoto, Hiroyuki; Watanabe, Shun-Ichi; Terauchi, Takashi; Moriyama, Noriyuki; Arai, Yasuaki; Sugimura, Kazuro; Kakizoe, Tadao

    2006-09-01

    Several types of recurrence may be detected by radiologic assessment after treatment in patients with prostate cancer. However, early detection of distant metastasis using positron emission tomography has so far never been published. We report two patients who underwent hormone therapy or surgical resection for prostate cancer. They developed distant metastases which were detected on whole body [C-11] choline positron emission tomography/computed tomography with significant elevation of serum PSA level. In one patient, recurrent tumor of the supraclavicular node (6 mm) diminished in size after subsequent hormone therapy. Surgical resection of recurrent tumor of the lung (12 mm) was performed in the other patient, the pathology of which confirmed the metastatic adenocarcinoma derived from the prostate. The recurrent tumor can be correctly detected by dual-phase whole body [C-11] choline positron emission tomography/computed tomography.

  8. Early-Dynamic Positron Emission Tomography (PET)/Computed Tomography and PET Angiography for Endoleak Detection After Endovascular Aneurysm Repair.

    PubMed

    Drescher, Robert; Gühne, Falk; Freesmeyer, Martin

    2017-06-01

    To propose a positron emission tomography (PET)/computed tomography (CT) protocol including early-dynamic and late-phase acquisitions to evaluate graft patency and aneurysm diameter, detect endoleaks, and rule out graft or vessel wall inflammation after endovascular aneurysm repair (EVAR) in one examination without intravenous contrast medium. Early-dynamic PET/CT of the endovascular prosthesis is performed for 180 seconds immediately after intravenous injection of F-18-fluorodeoxyglucose. Data are reconstructed in variable time frames (time periods after tracer injection) to visualize the arterial anatomy and are displayed as PET angiography or fused with CT images. Images are evaluated in view of vascular abnormalities, graft configuration, and tracer accumulation in the aneurysm sac. Whole-body PET/CT is performed 90 to 120 minutes after tracer injection. This protocol for early-dynamic PET/CT and PET angiography has the potential to evaluate vascular diseases, including the diagnosis of complications after endovascular procedures.

  9. Positron Emission Tomography - Computed Tomography (PET/CT)

    MedlinePlus

    ... Index A-Z Positron Emission Tomography - Computed Tomography (PET/CT) Positron emission tomography (PET) uses small amounts of ... CT)? What is Positron Emission Tomography – Computed Tomography (PET/CT) Scanning? Positron emission tomography, also called PET imaging ...

  10. Low Utility of Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography for Detecting Hepatocellular Carcinoma in Patients Before Liver Transplantation.

    PubMed

    Alotaibi, Faisal; Kabbani, Monther; Abaalkhail, Faisal; Chorley, Alicia; Elbeshbeshy, Hany; Al-Hamoudi, Waleed; Alabbad, Saleh; Boehnert, Markus U; Alsofayan, Mohammad; Al-Kattan, Wael; Ahmed, Baderaldeen; Broering, Dieter; Al Sebayel, Mohamed; Elsiesy, Hussien

    2017-02-01

    Our program routinely used fluorodeoxyglucose-positron emission tomography/computed tomography as part of the liver transplant evaluation of patients with hepatocellular carcinoma. The aim of this study was to evaluate the role of this imaging modality in the pretransplant work-up. This was a retrospective chart review of our liver transplant database from January 2011 to December 2014 for all patients with hepatocellular carcinoma who underwent a liver transplant. Collected data included age, sex, cause of liver disease, imaging modality, fluorodeoxyglucose-positron emission tomography/computed tomography results, explant tissue analysis, type of transplant, and transplant outcome. During the study period, 275 liver transplants were performed. Fifty-three patients had hepatocellular carcinoma; 41 underwent fluorodeoxyglucose-positron emission tomography/computed tomography. Twenty-nine patients underwent living-donor liver transplant, and 12 patients underwent deceased-donor liver transplant. One of the 41 patients with negative FDG-imaging results had no evidence of hepatocellular carcinoma in the explant and was excluded from the study. The patients' average age was 58 years (range, 22-72 y), and 28 patients were men. The cause of liver disease was hepatitis C virus in 24 patients, cryptogenic cirrhosis in 12 patients, and hepatitis B virus in 5 patients. One patient had no hepatocellular carcinoma on explants and was excluded from the study. Twenty-five patients had hepatocellular carcinoma that met the Milan criteria, 7 were within the UCSF (University of California, San Francisco) criteria, and 8 exceeded the UCSF criteria. Of the 40 patients, 11 had positive fluorodeoxyglucose-positron emission tomography/computed tomography results (27.5%) with evidence of hepatocellular carcinoma in the explant; the remaining 29 patients (72.5%) had negative results. The fluorodeoxyglucose-positron emission tomography/computed tomography results were positive in 16% (4 of

  11. (18) F-fluorodeoxyglucose positron emission tomography/computed tomography for the detection of recurrent bone and soft tissue sarcoma.

    PubMed

    Al-Ibraheem, Akram; Buck, Andreas K; Benz, Matthias R; Rudert, Maximilian; Beer, Ambros J; Mansour, Asem; Pomykala, Kelsey L; Haller, Bernhard; Juenger, Hendrik; Scheidhauer, Klemens; Schwaiger, Markus; Herrmann, Ken

    2013-03-15

    The clinical utility of modern hybrid imaging modalities for detecting recurrent bone or soft tissue sarcoma remains to be determined. In this report, the authors present a clinical study on the diagnostic accuracy and incremental value of integrated (18) F-fluorodeoxyglucose positron emission tomography/computed tomography ((18) F-FDG PET/CT) in patients with a history of sarcoma who have clinically suspected disease recurrence. Forty-three patients who had a history of bone or soft tissue sarcoma and had documented complete remission underwent (18) F-FDG PET/CT. Image analysis was performed independently for (18) F-FDG PET (n = 43) and for contrast-enhanced spiral CT (CE-CT) (n = 30) by 2 separate readers, whereas combined (18) F-FDG PET/CT (n = 43) images were analyzed in consensus by both readers. Imaging findings were rated on a 5-point scale and finally were reported as malignant, benign, or equivocal. Imaging findings were validated either by histopathology (n = 24) or by clinical follow-up (n = 19). (18) F-FDG PET/CT had greater sensitivity and specificity compared with CE-CT alone (94% and 92% vs 78% and 67%, respectively), resulting in significantly greater accuracy (93% vs 73%; P = .03). (18) F-FDG PET/CT was particularly superior regarding detection of local recurrence or soft tissue lesions (sensitivity and specificity: 83% and 100% vs 50% and 100%, respectively) or bone metastases (100% and 100% vs 85% and 88%, respectively). (18) F-FDG PET/CT had greater diagnostic accuracy in the detection of recurrent bone or soft tissue sarcoma compared with CE-CT alone. The detection of local recurrence was the most evident advantage of (18) F-FDG PET/CT over CE-CT. Cancer 2013. © 2012 American Cancer Society. Copyright © 2012 American Cancer Society.

  12. Positron emission tomography in the diagnostic work-up of screening-detected lung nodules.

    PubMed

    Veronesi, Giulia; Travaini, Laura L; Maisonneuve, Patrick; Rampinelli, Cristiano; Bertolotti, Raffaella; Spaggiari, Lorenzo; Bellomi, Massimo; Paganelli, Giovanni

    2015-02-01

    Low-dose computed tomography (CT) screening for lung cancer can reduce lung cancer mortality, but overdiagnosis, false positives and invasive procedures for benign nodules are worrying. We evaluated the utility of positron emission tomography (PET)-CT in characterising indeterminate screening-detected lung nodules. 383 nodules, examined by PET-CT over the first 6 years of the COSMOS (Continuous Observation of Smoking Subjects) study to diagnose primary lung cancer, were reviewed and compared with pathological findings (surgically-treated patients) or follow-up (negative CT for ⩾2 years, considered negative); 196 nodules were malignant. The sensitivity, specificity and accuracy of PET-CT for differentially diagnosing malignant nodules were, respectively, 64%, 89% and 76% overall, and 82%, 92% and 88% for baseline-detected nodules. Performance was lower for nodules found at repeat annual scans, with sensitivity ranging from 22% for nonsolid to 79% for solid nodules (p=0.0001). Sensitivity (87%) and specificity (73%) were high for nodules ⩾15 mm, better (sensitivity 98%) for solid nodules ⩾15 mm. PET-CT was highly sensitive for the differential diagnosis of indeterminate nodules detected at baseline, nodules ⩾15 mm and solid nodules. Sensitivity was low for sub-solid nodules and nodules discovered after baseline for which other methods, e.g. volume doubling time, should be used.

  13. Use of single-photon emission computed tomography/low-resolution computed tomography fusion imaging in detecting an unusually presenting osteoid osteoma of the lumbar vertebra.

    PubMed

    Hephzibah, Julie; Theodore, Bernice; Oommen, Regi; David, Kenny; Moses, Vinu; Shah, Sanjeev; Panicker, Jayalakshmi

    2009-03-01

    In this article, we describe an unusual presentation of osteoid osteoma of the lumbar vertebra in a woman in her early 30s. Single-photon emission computed tomography/low-resolution computed tomography (SPECT/CT) fusion imaging was used to detect the osteoma, precisely localize the pathology site, and guide surgical excision of the lesion. In recent years, SPECT/CT fusion imaging has helped make interpretations of scintigraphic images significantly more accurate.

  14. Positron emission tomography in the detection of occult primary head and neck carcinoma: a retrospective study

    PubMed Central

    2012-01-01

    Background The management of cervical lymph node metastases from an unknown primary tumor remains a controversial subject. Recently, Positron Emission Tomography (PET) has proved useful in the detection of these tumors, even after an unsuccessful conventional diagnostic workup. This study was performed to assess the role of PET in the detection of occult primary head and neck carcinomas. Methods A retrospective analysis of a four year period at a tertiary referral oncology hospital was conducted. Results Of the 49 patients with cervical metastases of carcinoma from an unknown primary, PET detected a primary in 9 patients and gave 5 false positive and 4 false negative results. Detection rate, sensitivity, specificity and accuracy were of 18.4%, 69.2%, 86.1% and 81.6%, respectively. PET was also of substantial benefit in detecting distant metastatic disease and, thus, altered therapeutic strategies in a significant amount of patients. Conclusions Therefore, PET is a valuable tool in the management of patients with occult primary head and neck carcinoma, not only because it provides additional information as to the location of primary tumors, but also due to the fact that it can detect unexpected distant metastases. PMID:22709938

  15. F-18 Fluoride Positron Emission Tomography-Computed Tomography for Detecting Atherosclerotic Plaques.

    PubMed

    Kang, Won Jun

    2015-01-01

    A large number of major cardiovascular events occur in patients due to minimal or some lumen narrowing of the coronary artery. Recent biological studies have shown that the biological composition or vulnerability of the plaque is more critical for plaque rupture compared to the degree of stenosis. To overcome the limitations of anatomical images, molecular imaging techniques have been suggested as promising imaging tools in various fields. F-18 fluorodeoxyglucose (FDG), which is widely used in the field of oncology, is an example of molecular probes used in atherosclerotic plaque evaluation. FDG is a marker of plaque macrophage glucose utilization and inflammation, which is a prominent characteristic of vulnerable plaque. Recently, F-18 fluoride has been used to visualize vulnerable plaque in clinical studies. F-18 fluoride accumulates in regions of active microcalcification, which is normally observed during the early stages of plaque formation. More studies are warranted on the accumulation of F-18 fluoride and plaque formation/vulnerability; however, due to high specific accumulation, low background activity, and easy accessibility, F-18 fluoride is emerging as a promising non-invasive imaging probe to detect vulnerable plaque.

  16. Cardiac positron emission tomography

    SciTech Connect

    Geltman, E.M.

    1985-12-01

    Positron emission tomography (PET) is a new technique for noninvasively assessing myocardial metabolism and perfusion. It has provided new insight into the dynamics of myocardial fatty acid and glucose metabolism in normal subjects, patients with ischemic heart disease and those with cardiomyopathies, documenting regionally depressed fatty acid metabolism during myocardial ischemia and infarction and spatial heterogeneity of fatty acid metabolism in patients with cardiomyopathy. Regional myocardial perfusion has been studied with PET using water, ammonia and rubidium labeled with positron emitters, permitting the noninvasive detection of hypoperfused zones at rest and during vasodilator stress. With these techniques the relationship between perfusion and the metabolism of a variety of substrates has been studied. The great strides that have been made in developing faster high-resolution instruments and producing new labeled intermediates indicate the promise of this technique for facilitating an increase in the understanding of regional metabolism and blood flow under normal and pathophysiologic conditions. 16 references, 9 figures, 2 tables.

  17. Rapid calculation of detectability in Bayesian single photon emission computed tomography

    NASA Astrophysics Data System (ADS)

    Xing, Yuxiang; Hsiao, Ing-Tsung; Gindi, Gene

    2003-11-01

    We consider the calculation of lesion detectability using a mathematical model observer, the channelized Hotelling observer (CHO), in a signal-known-exactly/background-known-exactly detection task for single photon emission computed tomography (SPECT). We focus on SPECT images reconstructed with Bayesian maximum a posteriori methods. While model observers are designed to replace time-consuming studies using human observers, the calculation of CHO detectability is usually accomplished using a large number of sample images, which is still time consuming. We develop theoretical expressions for a measure of detectability, the signal-to-noise-ratio (SNR) of a CHO observer, that can be very rapidly evaluated. Key to our expressions are approximations to the reconstructed image covariance. In these approximations, we use methods developed in the PET literature, but modify them to reflect the different nature of attenuation and distance-dependent blur in SPECT. We validate our expressions with Monte Carlo methods. We show that reasonably accurate estimates of the SNR can be obtained at a computational expense equivalent to approximately two projection operations, and that evaluating SNR for subsequent lesion locations requires negligible additional computation.

  18. Low background high efficiency radiocesium detection system based on positron emission tomography technology

    SciTech Connect

    Yamamoto, Seiichi; Ogata, Yoshimune

    2013-09-15

    After the 2011 nuclear power plant accident at Fukushima, radiocesium contamination in food became a serious concern in Japan. However, low background and high efficiency radiocesium detectors are expensive and huge, including semiconductor germanium detectors. To solve this problem, we developed a radiocesium detector by employing positron emission tomography (PET) technology. Because {sup 134}Cs emits two gamma photons (795 and 605 keV) within 5 ps, they can selectively be measured with coincidence. Such major environmental gamma photons as {sup 40}K (1.46 MeV) are single photon emitters and a coincidence measurement reduces the detection limit of radiocesium detectors. We arranged eight sets of Bi{sub 4}Ge{sub 3}O{sub 12} (BGO) scintillation detectors in double rings (four for each ring) and measured the coincidence between these detectors using PET data acquisition system. A 50 × 50 × 30 mm BGO was optically coupled to a 2 in. square photomultiplier tube (PMT). By measuring the coincidence, we eliminated most single gamma photons from the energy distribution and only detected those from {sup 134}Cs at an average efficiency of 12%. The minimum detectable concentration of the system for the 100 s acquisition time is less than half of the food monitor requirements in Japan (25 Bq/kg). These results show that the developed radiocesium detector based on PET technology is promising to detect low level radiocesium.

  19. Low background high efficiency radiocesium detection system based on positron emission tomography technology

    NASA Astrophysics Data System (ADS)

    Yamamoto, Seiichi; Ogata, Yoshimune

    2013-09-01

    After the 2011 nuclear power plant accident at Fukushima, radiocesium contamination in food became a serious concern in Japan. However, low background and high efficiency radiocesium detectors are expensive and huge, including semiconductor germanium detectors. To solve this problem, we developed a radiocesium detector by employing positron emission tomography (PET) technology. Because 134Cs emits two gamma photons (795 and 605 keV) within 5 ps, they can selectively be measured with coincidence. Such major environmental gamma photons as 40K (1.46 MeV) are single photon emitters and a coincidence measurement reduces the detection limit of radiocesium detectors. We arranged eight sets of Bi4Ge3O12 (BGO) scintillation detectors in double rings (four for each ring) and measured the coincidence between these detectors using PET data acquisition system. A 50 × 50 × 30 mm BGO was optically coupled to a 2 in. square photomultiplier tube (PMT). By measuring the coincidence, we eliminated most single gamma photons from the energy distribution and only detected those from 134Cs at an average efficiency of 12%. The minimum detectable concentration of the system for the 100 s acquisition time is less than half of the food monitor requirements in Japan (25 Bq/kg). These results show that the developed radiocesium detector based on PET technology is promising to detect low level radiocesium.

  20. Low background high efficiency radiocesium detection system based on positron emission tomography technology.

    PubMed

    Yamamoto, Seiichi; Ogata, Yoshimune

    2013-09-01

    After the 2011 nuclear power plant accident at Fukushima, radiocesium contamination in food became a serious concern in Japan. However, low background and high efficiency radiocesium detectors are expensive and huge, including semiconductor germanium detectors. To solve this problem, we developed a radiocesium detector by employing positron emission tomography (PET) technology. Because (134)Cs emits two gamma photons (795 and 605 keV) within 5 ps, they can selectively be measured with coincidence. Such major environmental gamma photons as (40)K (1.46 MeV) are single photon emitters and a coincidence measurement reduces the detection limit of radiocesium detectors. We arranged eight sets of Bi4Ge3O12 (BGO) scintillation detectors in double rings (four for each ring) and measured the coincidence between these detectors using PET data acquisition system. A 50 × 50 × 30 mm BGO was optically coupled to a 2 in. square photomultiplier tube (PMT). By measuring the coincidence, we eliminated most single gamma photons from the energy distribution and only detected those from (134)Cs at an average efficiency of 12%. The minimum detectable concentration of the system for the 100 s acquisition time is less than half of the food monitor requirements in Japan (25 Bq/kg). These results show that the developed radiocesium detector based on PET technology is promising to detect low level radiocesium.

  1. Quantitative assessment of lesion detection accuracy, resolution, and reconstruction algorithms in neutron stimulated emission computed tomography.

    PubMed

    Lakshmanan, Manu N; Kapadia, Anuj J

    2012-07-01

    We present a quantitative analysis of the image quality obtained using filtered back-projection (FBP) with Ram-Lak filtering and maximum likelihood-expectation maximization (ML-EM)-with no post-reconstruction filtering in either case-in neutron stimulated emission computed tomography (NSECT) imaging using Monte Carlo simulations in the context of clinically relevant models of liver iron overload. The ratios of pixel intensities for several regions of interest and lesion shape detection using an active-contours segmentation algorithm are assessed for accuracy across different scanning configurations and reconstruction algorithms. The modulation transfer functions (MTFs) are also computed for the cases under study and are applied to determine a minimum detectable lesion spacing as a form of sensitivity analysis. The accuracy of NSECT imaging in measuring relative tissue concentration is presented for simulated clinical liver cases. When using the 15th iteration, ML-EM provides at least 25% better resolution than FBP and proves to be highly robust under low-signal high-noise conditions prevalent in NSECT. However, FBP gives more accurate lesion pixel intensity ratios and size estimates in some cases; due to advantages provided by both reconstruction algorithms, it is worth exploring the development of an algorithm that is a hybrid of the two. We also show that NSECT imaging can be used to accurately detect 3-cm lesions in backgrounds that are a significant fraction (one-quarter) of the concentration of the lesion, down to a 4-cm spacing between lesions.

  2. A promising new mechanism of ionizing radiation detection for positron emission tomography: modulation of optical properties

    NASA Astrophysics Data System (ADS)

    Tao, Li; Daghighian, Henry M.; Levin, Craig S.

    2016-11-01

    Using conventional scintillation detection, the fundamental limit in positron emission tomography (PET) time resolution is strongly dependent on the inherent temporal variances generated during the scintillation process, yielding an intrinsic physical limit for the coincidence time resolution of around 100 ps. On the other hand, modulation mechanisms of the optical properties of a material exploited in the optical telecommunications industry can be orders of magnitude faster. In this paper we borrow from the concept of optics pump-probe measurement to for the first time study whether ionizing radiation can produce modulations of optical properties, which can be utilized as a novel method for radiation detection. We show that a refractive index modulation of approximately 5× {{10}-6} is induced by interactions in a cadmium telluride (CdTe) crystal from a 511 keV photon source. Furthermore, using additional radionuclide sources, we show that the amplitude of the optical modulation signal varies linearly with both the detected event rate and average photon energy of the radiation source.

  3. Comparing propofol versus sevoflurane anesthesia for epileptogenic focus detection during positron emission tomography in pediatric patients.

    PubMed

    Wagner, K J; Schulz, C M; Sprenger, T; Pieper, T; Heuser, F; Hohmann, C P; Wermke, M; Martin, J; Drzezga, A

    2013-11-01

    Fluoro-D-deoxyglucose positron emission tomography (FDG-PET) is a standard procedure for interictal assessment and accurate pre-surgical evaluation of presumed epileptogenic zone localization. Profound sedation or general anesthesia is frequently required to reduce movement artefacts in young or cognitively impaired patients during image acquisition. This study compares the impact of propofol and sevoflurane anesthesia on overall quality of PET images, detectability of a hypometabolic lesion and demarcation of the detected lesion in pediatric patients suffering from focal epilepsia. Pediatric patients with focal epilepsia were anesthesized using propofol (N.=37) or sevoflurane (N.=43). Two independent blinded investigators rated the PET-scans on a 3-point Likert scale with respect to overall quality of PET images, detectability of a hypometabolic lesion and demarcation of the detected lesion. Mann-Whitney-U-Test was conducted to compare the rating results between the two anesthesia regimes. Inter-rater reliability was calculated using Cohen's Kappa. Anesthesia was throughout uneventful and there was no clinical evidence for peridiagnostic seizures. Differences in neither single dimension ratings nor in sum scores (mean 5.8 ± SD 1.5 for propofol, and 5.7 ± SD 1.5 for sevoflurane; P=0.567) were statistically significant. Cohen's Kappa was between 0.428 and 0.499. For surgical planning in patients with epilepsy, FDG-PET imaging is an indispensable functional imaging technique to detect hypometabolism. We conclude that both, sevoflurane and propofol based anesthetic regimes are suitable to detect hypometabolic cerebral lesions during FDG-PET.

  4. Breast cancer detection using neutron stimulated emission computed tomography: prominent elements and dose requirements.

    PubMed

    Bender, Janelle E; Kapadia, Anuj J; Sharma, Amy C; Tourassi, Georgia D; Harrawood, Brian P; Floyd, Carey E

    2007-10-01

    Neutron stimulated emission computed tomography (NSECT) is being developed to noninvasively determine concentrations of trace elements in biological tissue. Studies have shown prominent differences in the trace element concentration of normal and malignant breast tissue. NSECT has the potential to detect these differences and diagnose malignancy with high accuracy with dose comparable to that of a single mammogram. In this study, NSECT imaging was simulated for normal and malignant human breast tissue samples to determine the significance of individual elements in determining malignancy. The normal and malignant models were designed with different elemental compositions, and each was scanned spectroscopically using a simulated 2.5 MeV neutron beam. The number of incident neutrons was varied from 0.5 million to 10 million neutrons. The resulting gamma spectra were evaluated through receiver operating characteristic (ROC) analysis to determine which trace elements were prominent enough to be considered markers for breast cancer detection. Four elemental isotopes (133Cs, 81Br, 79Br, and 87Rb) at five energy levels were shown to be promising features for breast cancer detection with an area under the ROC curve (A(Z)) above 0.85. One of these elements--87Rb at 1338 keV--achieved perfect classification at 10 million incident neutrons and could be detected with as low as 3 million incident neutrons. Patient dose was calculated for each gamma spectrum obtained and was found to range from between 0.05 and 0.112 mSv depending on the number of neutrons. This simulation demonstrates that NSECT has the potential to noninvasively detect breast cancer through five prominent trace element energy levels, at dose levels comparable to other breast cancer screening techniques.

  5. Breast cancer detection using neutron stimulated emission computed tomography: Prominent elements and dose requirements

    SciTech Connect

    Bender, Janelle E.; Kapadia, Anuj J.; Sharma, Amy C.; Tourassi, Georgia D.; Harrawood, Brian P.; Floyd, Carey E. Jr.

    2007-10-15

    Neutron stimulated emission computed tomography (NSECT) is being developed to noninvasively determine concentrations of trace elements in biological tissue. Studies have shown prominent differences in the trace element concentration of normal and malignant breast tissue. NSECT has the potential to detect these differences and diagnose malignancy with high accuracy with dose comparable to that of a single mammogram. In this study, NSECT imaging was simulated for normal and malignant human breast tissue samples to determine the significance of individual elements in determining malignancy. The normal and malignant models were designed with different elemental compositions, and each was scanned spectroscopically using a simulated 2.5 MeV neutron beam. The number of incident neutrons was varied from 0.5 million to 10 million neutrons. The resulting gamma spectra were evaluated through receiver operating characteristic (ROC) analysis to determine which trace elements were prominent enough to be considered markers for breast cancer detection. Four elemental isotopes ({sup 133}Cs, {sup 81}Br, {sup 79}Br, and {sup 87}Rb) at five energy levels were shown to be promising features for breast cancer detection with an area under the ROC curve (A{sub Z}) above 0.85. One of these elements - {sup 87}Rb at 1338 keV - achieved perfect classification at 10 million incident neutrons and could be detected with as low as 3 million incident neutrons. Patient dose was calculated for each gamma spectrum obtained and was found to range from between 0.05 and 0.112 mSv depending on the number of neutrons. This simulation demonstrates that NSECT has the potential to noninvasively detect breast cancer through five prominent trace element energy levels, at dose levels comparable to other breast cancer screening techniques.

  6. Effectiveness of positron emission tomography for the detection of melanoma metastases.

    PubMed Central

    Holder, W D; White, R L; Zuger, J H; Easton, E J; Greene, F L

    1998-01-01

    OBJECTIVE: The purpose of this study was to determine the sensitivity, specificity, and clinical utility of 18F 2-fluoro-2-deoxy-D-glucose (FDG) total-body positron emission tomography (PET) scanning for the detection of metastases in patients with malignant melanoma. SUMMARY BACKGROUND DATA: Recent preliminary reports suggest that PET using FDG may be more sensitive and specific for detection of metastatic melanoma than standard radiologic imaging studies using computed tomography (CT). PET technology is showing utility in the detection of metastatic tumors from multiple primary sites including breast, lung, lymphoma, and melanoma. However, little information is available concerning the general utility, sensitivity, and specificity of PET scanning of patients with metastatic melanoma. METHODS: One hundred three PET scans done on 76 nonrandomized patients having AJCC stage II to IV melanoma were prospectively evaluated. Patients were derived from two groups. Group 1 (63 patients) had PET, CT (chest and abdomen), and magnetic resonance imaging (MRI; brain) scans as a part of staging requirements for immunotherapy protocols. Group 2 (13 nonprotocol patients) had PET, CT, and MRI scans as in group 1, but for clinical evaluation only. PET scans were done using 12 to 20 mCi of FDG given intravenously. Results of PET scans were compared to CT scans and biopsy or cytology results. RESULTS: PET scanning for the detection of melanoma metastases had a sensitivity of 94.2% and a specificity of 83.3% compared to 55.3% and 84.4%, respectively, for CT scanning. Factors that produced false-positive PET scans were papillary carcinoma of the thyroid (1), bronchogenic carcinoma (1), inflamed epidermal cyst (1), Warthin's tumor of the parotid gland (1), surgical wound inflammation (2), leiomyoma of the uterus (1), suture granuloma (1), and endometriosis (1). The four false-negative scans were thought to be due to smaller (<0.3 to 0.5 cm) and diffuse areas of melanoma without a mass

  7. A new mechanism of ionizing radiation detection for positron emission tomography: modulation of optical properties

    NASA Astrophysics Data System (ADS)

    Tao, Li; Daghighian, Henry M.; Levin, Craig S.

    2016-10-01

    Using conventional scintillation detection, the fundamental limit in positron emission tomography (PET) annihilation photon pair coincidence time resolution is strongly dependent on the inherent temporal variances generated during the scintillation process, yielding an intrinsic physical limit of around 100 ps. On the other hand, modulation mechanisms of a material's optical properties as exploited in the optical telecommunications industry can be orders of magnitude faster. In this paper we borrow from the concept of optics pump-probe measurement to study whether ionizing radiation can also produce fast modulations of optical properties, which can be utilized as a novel method for radiation detection. We show that a refractive index modulation of approximately 5x10-6 is induced by interactions in a cadmium telluride (CdTe) crystal from a 511 keV photon source. Furthermore, using additional radionuclide sources, we show that the amplitude of the optical modulation signal varies linearly with both the radiation source flux rate and average photon energy.

  8. Detection of neuronal damage in degenerative brain disease with cobalt-55 and positron emission tomography

    SciTech Connect

    Jansen, H.M.L.; Pruim, J.; Paans, A.M.J.

    1994-05-01

    We suggest Cobalt-55 (Co) as a Calcium (Ca)-marker to visualize Ca transport across the neuronal membrane. Elevation of intracellular Ca is closely linked with the process of neuronal cell-decay. Co-uptake is correlated with Ca-accumulation through divalent cation-permeable kainate (KA)-activated receptor-operated channels in the neuronal membrane. This hypothesis was studied with position emission tomography (PET) both in patients with a ischemic cerebro-vascular accident (CVA) and in patients with relapsing progressive multiple sclerosis (MS). Co-PET studies were performed in a dynamic mode (6 frames of 10 minutes) 20-25 hours after iv.-administration of 1-2 mCi Co. Regional specific accumulation irrespective of blood brain barrier (BBB) integrity in the (clinically appropriate) affected cerebral region could be demonstrated in CVA-patients, thus suggesting neuronal decay in (the early phase of) infarction. In MS, inhomogeneous cerebral distribution of Co was detected, in contrast to healthy volunteers. This suggests focal accumulation of Co in multiple spots of neuronal decay, possibly related to MS-lesions on MRI. In conclusion, Co-PET may prove to be a valuable tool for the early detection of neuronal decay not only in CVA and MS, but in other brain-pathology as well. The usefulness of Co-PET in imaging brain-tumors and myocardial ischemia has already been established.

  9. Optic nerve sheath meningioma detected by single- photon emission computed tomography/computed tomography somatostatin receptor scintigraphy: a case report.

    PubMed

    Nussbaum-Hermassi, Lucie; Ahle, Guido; Zaenker, Chistophe; Duca, Camelia; Namer, Izzie Jacques

    2016-04-22

    Optic nerve sheath meningiomas account for only 2% of orbital lesions and 42% of optic nerve tumors. Diagnosis remains difficult because histologic confirmation carries a high risk of visual loss. Therefore, a less invasive and specific diagnostic method for differentiating optic nerve sheath meningiomas from other optic nerve lesions is needed to overcome the limitations of computed tomography and magnetic resonance imaging, and make the best individualized treatment decision. This case is a good illustration of the clinical and imaging difficulties inherent in this rare tumor, which may be hard to differentiate from other causes. A 51-year-old Caucasian woman developed a central scotoma, visual loss, and abnormal visual evoked potentials. The first magnetic resonance imaging scan classified the optic nerve damage as retrobulbar optic neuritis. After magnetic resonance imaging follow-up at 3 months, a negative lumbar puncture and biological workup, and clinical worsening, an optic nerve sheath meningioma was suspected. We confirmed this diagnosis with 111In-pentetreotide single-photon emission computed tomography, which is able to bind with very high affinity to somatostatin receptor subtype 2 expressed on meningiomas. In the diagnosis of optic nerve sheath meningiomas, [111In]-pentetreotide single-photon emission computed tomography-fused magnetic resonance imaging is a valuable additional tool, optimizing the diagnosis and obviating the need for a more invasive procedure.

  10. Brown adipose tissue in humans: detection and functional analysis using PET (positron emission tomography), MRI (magnetic resonance imaging), and DECT (dual energy computed tomography).

    PubMed

    Borga, Magnus; Virtanen, Kirsi A; Romu, Thobias; Leinhard, Olof Dahlqvist; Persson, Anders; Nuutila, Pirjo; Enerbäck, Sven

    2014-01-01

    If the beneficial effects of brown adipose tissue (BAT) on whole body metabolism, as observed in nonhuman experimental models, are to be translated to humans, tools that accurately measure how BAT influences human metabolism will be required. This chapter discusses such techniques, how they can be used, what they can measure and also some of their limitations. The focus is on detection and functional analysis of human BAT and how this can be facilitated by applying advanced imaging technology such as positron emission tomography, magnetic resonance imaging, and dual energy computed tomography. © 2014 Elsevier Inc. All rights reserved.

  11. Detection of cardiovascular system involvement in Behçet's disease using fluorodeoxyglucose positron emission tomography.

    PubMed

    Cho, Sung Bin; Yun, Mijin; Lee, Jae-Hoon; Kim, Jihyun; Shim, Won-Heum; Bang, Dongsik

    2011-04-01

    Behçet's disease (BD) theoretically affects all sizes and types of vessels; however, there have been few reports describing the clinical efficacy of using (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in patients with BD. Eight patients who were registered at the BD Specialty Clinic of Severance Hospital between 2004 and 2008 underwent FDG-PET scans to evaluate the cardiovascular presentations associated with BD. Medical records and FDG-PET images of the patients were retrospectively reviewed to determine the clinical significance of the cardiovascular findings. The median quantitative FDG uptake index was 1.46 (range, 0.58-2.61). FDG uptake was detected in multiple pseudoaneurysms, aortitis and arteritis associated with aortic regurgitation, and aneurysmatic dilation of the sinus of Valsalva, atherosclerotic change of the proximal ascending aorta associated with aortic regurgitation, and multiple pulmonary artery aneurysms. The quantitative FDG uptake intensity was significantly associated with the ESR level. FDG-PET scans may have clinical value as a workup study for patients with BD who have cardiovascular presentations. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Regional changes in extravascular lung water detected by positron emission tomography

    SciTech Connect

    Schuster, D.P.; Marklin, G.F.; Mintun, M.A.

    1986-04-01

    Regional measurements of extravascular lung water (rEVLW) were made with positron emission tomography (PET) and 15O-labeled radionuclides. The label used to measure the total lung water (TLW) content fully equilibrated with TLW prior to scanning in both dogs with normal and low cardiac outputs, and nearly so in areas of lung made edematous by oleic acid injury (the TLW values used were 97% of maximum values). Regional EVLW measurements made by PET (EVLW-PET) and gravimetric techniques in both normal and edematous lung were closely correlated (r = 0.93), and EVLW-PET increased from an average of 0.20 to 0.37 mlH/sub 2/O/ml lung (P less than 0.05) after regional lung injury. PET measurements of regional blood volume always decreased (from an average of 0.12 to 0.09 ml blood/ml lung (P less than 0.05)) after cardiac output was lowered by hemorrhage in a separate set of animals. Total EVLW (by thermodye indicator dilution) did not change. Likewise, regional EVLW remained constant in areas below the left atrium but decreased in areas above the left atrium. We conclude that PET measurements are accurate, noninvasive, and reproducible and that regional changes may be detected even when measurements of total EVLW by other methods may fail to change significantly.

  13. Positron emission tomography detects tissue metabolic activity in myocardial segments with persistent thallium perfusion defects

    SciTech Connect

    Brunken, R.; Schwaiger, M.; Grover-McKay, M.; Phelps, M.E.; Tillisch, J.; Schelbert, H.R.

    1987-09-01

    Positron emission tomography with /sup 13/N-ammonia and /sup 18/F-2-deoxyglucose was used to assess myocardial perfusion and glucose utilization in 51 myocardial segments with a stress thallium defect in 12 patients. Myocardial infarction was defined by a concordant reduction in segmental perfusion and glucose utilization, and myocardial ischemia was identified by preservation of glucose utilization in segments with rest hypoperfusion. Of the 51 segments studied, 36 had a fixed thallium defect, 11 had a partially reversible defect and 4 had a completely reversible defect. Only 15 (42%) of the 36 segments with a fixed defect and 4 (36%) of the 11 segments with a partially reversible defect exhibited myocardial infarction on study with positron tomography. In contrast, residual myocardial glucose utilization was identified in the majority of segments with a fixed (58%) or a partially reversible (64%) thallium defect. All of the segments with a completely reversible defect appeared normal on positron tomography. Apparent improvement in the thallium defect on delayed images did not distinguish segments with ischemia from infarction. Thus, positron emission tomography reveals evidence of persistent tissue metabolism in the majority of segments with a fixed or partially resolving stress thallium defect, implying that markers of perfusion alone may underestimate the extent of viable tissue in hypoperfused myocardial segments.

  14. Escherichia coli Nissle 1917 facilitates tumor detection by positron emission tomography and optical imaging.

    PubMed

    Brader, Peter; Stritzker, Jochen; Riedl, Christopher C; Zanzonico, Pat; Cai, Shangde; Burnazi, Eva M; Ghani, E Rashid; Hricak, Hedvig; Szalay, Aladar A; Fong, Yuman; Blasberg, Ronald

    2008-04-15

    Bacteria-based tumor-targeted therapy is a modality of growing interest in anticancer strategies. Imaging bacteria specifically targeting and replicating within tumors using radiotracer techniques and optical imaging can provide confirmation of successful colonization of malignant tissue. The uptake of radiolabeled pyrimidine nucleoside analogues and [18F]FDG by Escherichia coli Nissle 1917 (EcN) was assessed both in vitro and in vivo. The targeting of EcN to 4T1 breast tumors was monitored by positron emission tomography (PET) and optical imaging. The accumulation of radiotracer in the tumors was correlated with the number of bacteria. Optical imaging based on bioluminescence was done using EcN bacteria that encode luciferase genes under the control of an l-arabinose-inducible P(BAD) promoter system. We showed that EcN can be detected using radiolabeled pyrimidine nucleoside analogues, [18F]FDG and PET. Importantly, this imaging paradigm does not require transformation of the bacterium with a reporter gene. Imaging with [18F]FDG provided lower contrast than [18F]FEAU due to high FDG accumulation in control (nontreated) tumors and surrounding tissues. A linear correlation was shown between the number of viable bacteria in tumors and the accumulation of [18F]FEAU, but not [18F]FDG. The presence of EcN was also confirmed by bioluminescence imaging. EcN can be imaged by PET, based on the expression of endogenous E. coli thymidine kinase, and this imaging paradigm could be translated to patient studies for the detection of solid tumors. Bioluminescence imaging provides a low-cost alternative to PET imaging in small animals.

  15. Detection of occult disease in breast cancer using fluorodeoxyglucose camera-based positron emission tomography.

    PubMed

    Pecking, A P; Mechelany-Corone, C; Bertrand-Kermorgant, F; Alberini, J L; Floiras, J L; Goupil, A; Pichon, M F

    2001-10-01

    An isolated increase of blood tumor marker CA 15.3 in breast cancer is considered a sensitive indicator for occult metastatic disease but by itself is not sufficient for initiating therapeutic intervention. We investigated the potential of camera-based positron emission tomography (PET) imaging using [18F]-fluorodeoxyglucose (FDG) to detect clinically occult recurrences in 132 female patients (age, 35-69 years) treated for breast cancer, all presenting with an isolated increase in blood tumor marker CA 15.3 without any other evidence of metastatic disease. FDG results were correlated to pathology results or to a sequentially guided conventional imaging method. One hundred nineteen patients were eligible for correlations. Positive FDG scans were obtained for 106 patients, including 89 with a single lesion and 17 with 2 or more lesion. There were 92 true-positive and 14 false-positive cases, 10 of which became true positive within 1 year. Among the 13 negative cases, 7 were false negative and 6 were true negative. Camera-based PET using FDG has successfully identified clinically occult disease with an overall sensitivity of 93.6% and a positive predictive value of 96.2%. The smallest detected size was 6 mm for a lymph node metastasis (tumor to nontumor ratio, 4:2). FDG camera-based PET localized tumors in 85.7% of cases suspected for clinically occult metastatic disease on the basis of a significant increase in blood tumor marker. A positive FDG scan associated with an elevated CA 15.3 level is most consistent with metastatic relapse of breast cancer.

  16. Endobronchial ultrasound-guided transbronchial needle aspiration of hilar and mediastinal lymph nodes detected on 18F-fluorodeoxyglucose positron emission tomography/computed tomography

    PubMed Central

    Minami, Daisuke; Takigawa, Nagio; Oda, Naohiro; Ninomiya, Takashi; Kubo, Toshio; Ohashi, Kadoaki; Sato, Akiko; Hotta, Katsuyuki; Tabata, Masahiro; Kaji, Mitsumasa; Tanimoto, Mitsune; Kiura, Katsuyuki

    2016-01-01

    Objective Endobronchial ultrasound-guided transbronchial needle aspiration is of diagnostic value in hilar/mediastinal (N1/N2) lymph node staging. We assessed the utility of endobronchial ultrasound-guided transbronchial needle aspiration in lung cancer patients with N1/N2 lymph nodes detected on 18F-fluorodeoxyglucose positron emission tomography/computed tomography. Methods Fifty lung cancer patients with N1/N2 disease on 18F-fluorodeoxyglucose positron emission tomography/computed tomography underwent endobronchial ultrasound-guided transbronchial needle aspiration for pathological lymph nodes between November 2012 and April 2015. The diagnostic performance of endobronchial ultrasound-guided transbronchial needle aspiration, lymph node site and size, number of needle passes and complications were evaluated retrospectively from patients' medical records. Malignancy was defined as a maximum standardized uptake value (SUVmax) >2.5. Results The median longest diameter of the 61 lymph nodes (29 subcarinal, 21 right lower paratracheal, 6 left lower paratracheal, 4 right hilar and 1 upper paratracheal) was 23.4 mm (range: 10.4–45.7); the median number of needle passes was 2 (range: 1–5). There were no severe complications. A definitive diagnosis was made by endobronchial ultrasound-guided transbronchial needle aspiration in 39 patients (31 adenocarcinomas, 3 small-cell carcinomas, 2 squamous-cell carcinomas, 3 large-cell neuroendocrine carcinomas). In the remaining 11 patients, the diagnosis was indefinite: insufficient endobronchial ultrasound-guided transbronchial needle aspiration material was collected in two patients and non-specific lymphadenopathy was confirmed by endobronchial ultrasound-guided transbronchial needle aspiration or thoracotomy in the other nine patients. The mean lymph node SUVmax was 7.09 (range: 2.90–26.9) and was significantly higher in true-positive than in false-positive nodes (P < 0.05, t-test). Non-specific lymphadenopathy was

  17. Phase II safety and clinical comparison with single-photon emission computed tomography myocardial perfusion imaging for detection of coronary artery disease: flurpiridaz F 18 positron emission tomography.

    PubMed

    Berman, Daniel S; Maddahi, Jamshid; Tamarappoo, B K; Czernin, Johannes; Taillefer, Raymond; Udelson, James E; Gibson, C Michael; Devine, Marybeth; Lazewatsky, Joel; Bhat, Gajanan; Washburn, Dana

    2013-01-29

    This was a phase II trial to assess flurpiridaz F 18 for safety and compare its diagnostic performance for positron emission tomography (PET) myocardial perfusion imaging (MPI) with Tc-99m single-photon emission computed tomography (SPECT) MPI with regard to image quality, interpretative certainty, defect magnitude, and detection of coronary artery disease (CAD) (≥50% stenosis) on invasive coronary angiography (ICA). In pre-clinical and phase I studies, flurpiridaz F 18 has shown characteristics of an essentially ideal MPI tracer. One hundred forty-three patients from 21 centers underwent rest-stress PET and Tc-99m SPECT MPI. Eighty-six patients underwent ICA, and 39 had low-likelihood of CAD. Images were scored by 3 independent, blinded readers. A higher percentage of images were rated as excellent/good on PET versus SPECT on stress (99.2% vs. 88.5%, p < 0.01) and rest (96.9% vs. 66.4, p < 0.01) images. Diagnostic certainty of interpretation (percentage of cases with definitely abnormal/normal interpretation) was higher for PET versus SPECT (90.8% vs. 70.9%, p < 0.01). In 86 patients who underwent ICA, sensitivity of PET was higher than SPECT (78.8% vs. 61.5%, respectively, p = 0.02). Specificity was not significantly different (PET: 76.5% vs. SPECT: 73.5%). Receiver-operating characteristic curve area was 0.82 ± 0.05 for PET and 0.70 ± 0.06 for SPECT (p = 0.04). Normalcy rate was 89.7% with PET and 97.4% with SPECT (p = NS). In patients with CAD on ICA, the magnitude of reversible defects was greater with PET than SPECT (p = 0.008). Extensive safety assessment revealed that flurpiridaz F 18 was safe in this cohort. In this phase 2 trial, PET MPI with flurpiridaz F 18 was safe and superior to SPECT MPI for image quality, interpretative certainty, and overall CAD diagnosis. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  18. Emission tomography of the kidney

    SciTech Connect

    Teates, C.D.; Croft, B.Y.; Brenbridge, N.A.; Bray, S.T.; Williamson, B.R.

    1983-12-01

    Single photon emission computerized tomography (SPECT) was done on two patients with suspected renal masses. Nuclear scintigraphy was equivocal on two tumors readily identified by SPECT. Single photon tomography is cost effective and increases the reliability of nuclear scintigraphy.

  19. Positron Emission Tomography (PET)

    SciTech Connect

    Welch, M.J.

    1990-01-01

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET. 22 figs.

  20. Positron Emission Tomography (PET)

    DOE R&D Accomplishments Database

    Welch, M. J.

    1990-01-01

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET.

  1. Generalized local emission tomography

    DOEpatents

    Katsevich, Alexander J.

    1998-01-01

    Emission tomography enables locations and values of internal isotope density distributions to be determined from radiation emitted from the whole object. In the method for locating the values of discontinuities, the intensities of radiation emitted from either the whole object or a region of the object containing the discontinuities are inputted to a local tomography function .function..sub..LAMBDA..sup.(.PHI.) to define the location S of the isotope density discontinuity. The asymptotic behavior of .function..sub..LAMBDA..sup.(.PHI.) is determined in a neighborhood of S, and the value for the discontinuity is estimated from the asymptotic behavior of .function..sub..LAMBDA..sup.(.PHI.) knowing pointwise values of the attenuation coefficient within the object. In the method for determining the location of the discontinuity, the intensities of radiation emitted from an object are inputted to a local tomography function .function..sub..LAMBDA..sup.(.PHI.) to define the location S of the density discontinuity and the location .GAMMA. of the attenuation coefficient discontinuity. Pointwise values of the attenuation coefficient within the object need not be known in this case.

  2. Subcutaneous fatty tissue metastasis from renal cell carcinoma detected with fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography and magnetic resonance imaging

    PubMed Central

    Tatoğlu, Mehmet Tarιk; Özülker, Tamer; Değirmenci, Hülya; Sayιlgan, Ayşe Tülay

    2011-01-01

    A patient who had undergone left radical nephrectomy 11 years ago for renal cell carcinoma (RCC) was referred to our clinic for restaging. Fluorine-18 fluorodeoxyglucose (F18-FDG) positron emission tomography/computed tomography (F18-FDG PET/CT) showed hypometabolic area in left frontal region of the brain and increased FDG uptake in the subcutaneous fatty tissues of the right thigh. Histopathological examination of the biopsy material from the left frontal region and right gluteal region revealed metastasis of clear cell type RCC. Seven months later, a magnetic resonance ımaging (MRI) of right cruris showed a contrast-enhancing lesion with a diameter of 3.5 cm, located at the subcutaneous area of posterior part of right cruris. A concomitant F18-FDG PET/CT detected an increased FDG uptake focus in the proximal third of right cruris adjacent to the muscle planes and this finding was consistent with metastasis of RCC. PMID:21969776

  3. Applications of Beta Particle Detection for Synthesis and Usage of Radiotracers Developed for Positron Emission Tomography

    NASA Astrophysics Data System (ADS)

    Dooraghi, Alex Abreu

    Positron Emission Tomography (PET) is a noninvasive molecular imaging tool that requires the use of a radioactive compound or radiotracer which targets a molecular pathway of interest. We have developed and employed three beta particle radiation detection systems to advance PET. Specifically, the goals of these systems are to: 1. Automate dispensing of solutions containing a positron emitting isotope. 2. Monitor radioactivity on-chip during synthesis of a positron emitting radiotracer. 3. Assay cellular uptake on-chip of a positron emitting radiotracer. Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing an optimum environment for radiation workers, but also to ensure a quantitatively accurate workflow. For the first project, we describe the development and performance of a system for automated radioactivity distribution of beta particle emitting radioisotopes such as fluorine-18 (F-18). Key to the system is a radiation detector in-line with a peristaltic pump. The system demonstrates volume accuracy within 5 % for volumes of 20 muL or greater. When considering volumes of 20 muL or greater, delivered radioactivity is in agreement with the requested radioactivity as measured with the dose calibrator. The integration of the detector and pump leads to a flexible system that can accurately dispense solutions containing F-18 in radioactivity concentrations directly produced from a cyclotron (~ 0.1-1 mCi/muL), to low activity concentrations intended for preclinical mouse scans (~ 1-10 muCi/muL), and anywhere in between. Electrowetting on dielectric (EWOD) is an attractive microfluidic platform for batch synthesis of PET radiotracers. Visualization of radioisotopes on-chip is critical for synthesis optimization and technological development. For the second project, we describe the development and performance of a Cerenkov/real-time imaging system for PET radiotracer synthesis on EWOD. We also investigate

  4. The role of positron emission tomography in the detection of pancreatic disease

    SciTech Connect

    Syrota, A.; Duquesnoy, N.; Paraf, A.; Kellershohn, C.

    1982-04-01

    Positron emission tomography (PET) was used to assess possible pancreatic disease in 100 patients. Following injection of 10-15 mCi (370-740 MBq) of /sup 11/C-L-methionine, 4-12 transverse sections 2 cm thick were obtained. In 85 patients with a definite diagnosis (45 normal, 9 acute pancreatitis, 18 chronic pancreatitis, and 13 cancer), PET showed a sensitivity of 85.0%, a specificity of 97.8%, and an accuracy of 91.8%, higher than with transmission computed tomography (CT) or ultrasonography, despite relatively low spatial resolution; this can be explained by the fact that exocrine pancreatic function was altered prior to morphological change. In 22 normal subjects, 0.011 +/- 0.003% (mean +/- S.D.) of injected /sup 11/C was found in 1 ml of liver tissue and 0.015 +/- 0.005% in 1 ml of pancreatic tissue; the pancreas-to-liver concentration ratio was 1.3 +/- 0.4. Hepatic /sup 11/C concentration was identical in the four groups of patients. Pancreatic uptake of /sup 11/C-L-methionine was significantly lower in patients with chronic pancreatitis (n = 13) and pancreatic carcinoma (n = 10) (p <0.001); however, it was not possible to distinguish cancer from chronic pancreatitis because the same functional alteration occurred in both.

  5. The role of positron emission tomography in the detection of pancreatic disease

    SciTech Connect

    Syrota, A.; Duquesnoy, N.; Paraf, A.; Kellershohn, C.

    1982-04-01

    Positron emission tomography (PET) was used to assess possible pancreatic disease in 100 patients. Following injection of 10-15 mCi (370-740 MBq) of 11C-L-methionine, 4-12 transverse sections 2 cm thick were obtained. In 85 patients with a definite diagnosis (45 normal, 9 acute pancreatitis, 18 chronic pancreatitis, and 13 cancer), PET showed a sensitivity of 85.0%, a specificity of 97.8%, and an accuracy of 91.8%, higher than with transmission computed tomography (CT) or ultrasonography, despite relatively low spatial resolution; this can be explained by the fact that exocrine pancreatic function was altered prior to morphological change. In 22 normal subjects, 0.011 +/- 0.003% (mean +/- S.D). of injected 11C was found in 1 ml of liver tissue and 0.015 +/- 0.005% in 1 ml of pancreatic tissue; the pancreas-to-liver concentration ratio was 1.3 +/- 0.4. Hepatic 11C concentration was identical in the four groups of patients. Pancreatic uptake of 11C-L-methionine was significantly lower in patients with chronic pancreatitis (n . 13) and pancreatic carcinoma (n . 10) (p less than 0.001); however, it was not possible to distinguish cancer from chronic pancreatitis because the same functional alteration occurred in both.

  6. Single photon emission computerized tomography (SPECT) in detecting neurodegeneration in Huntington's disease.

    PubMed

    Reynolds, N C; Hellman, R S; Tikofsky, R S; Prost, R W; Mark, L P; Elejalde, B R; Lebel, R; Hamsher, K S; Swanson, S; Benezra, E E

    2002-01-01

    Single photon emission computerized tomography (SPECT) studies were performed on 34 manifest Huntington's disease (HD) patients at various stages of clinical pathology ranging from early chorea to late dystonia with or without signs of dementia and 12 pre-symptomatic patients with abnormal terminal CAG expansions. Thirty HD patients with obvious clinical signs and seven pre-symptomatic patients without signs or symptoms of HD displayed selective caudate hypoperfusion by direct visual inspection. Such qualitative, selective striatal hypoperfusion patterns can be indicative of early and persistent metabolic changes in striatal neuropathology. SPECT studies can be useful in documenting early pre-clinical changes in patients with abnormal terminal CAG expansions and in confirming the presence of caudate pathology in patients with clinical signs of HD.

  7. Detection of avascular necrosis in adults by single photon emission computed tomography

    SciTech Connect

    Collier, B.D.; Johnston, R.P.; Carrera, G.; Isitman, A.T.; Hellman, R.S.; Zielonka, J.S.

    1984-01-01

    Twenty-one adult patients with the clinical diagnosis of avascular necrosis (AVN) of the femoral head were examined with planar bone scintigraphy (high resolution collimator) and single photon emission computed tomography (SPECT). The duration of hip pain ranged from 1 day to 18 months. Risk factors (including steroids, renal transplantation, alcoholism, and trauma) were present in 17 cases. A final diagnosis of AVN (20 hips), osteochondral facture, or stress fracture, was established for 17 patients. The 4 remaining patients, who were radiographically normal and did not complain of pain 3 months later, were thought to have no significant bone pathology. SPECT and planar bone scintigraphy were reported as positive for AVN only if a photopenic bony defect could be identified. In particular, uniformly increased activity throughout the femoral head was not considered to be diagnostic of AVN. The authors conclude that by identifying a photopenic defect which is not evident on planar bone scintigraphy, SPECT can contribute to accurate diagnosis of AVN.

  8. Prospective Study of 68Ga-DOTATATE Positron Emission Tomography/Computed Tomography for Detecting Gastro-Entero-Pancreatic Neuroendocrine Tumors and Unknown Primary Sites

    PubMed Central

    Sadowski, Samira M.; Neychev, Vladimir; Millo, Corina; Shih, Joanna; Nilubol, Naris; Herscovitch, Peter; Pacak, Karel; Marx, Stephen J.

    2016-01-01

    Purpose Gastro-entero-pancreatic neuroendocrine tumors (GEPNETs) are increasing in incidence, and accurate staging is important for selecting the appropriate treatment. 68Ga-DOTATATE imaging is a promising approach for detecting GEPNETs and could help in selecting optimal therapeutic strategies. The aim of this study was to prospectively determine the clinical utility of 68Ga-DOTATATE positron emission tomography (PET)/computed tomography (CT) in detecting unknown primary and metastatic GEPNETs. Patients and Methods One hundred thirty-one patients were enrolled in a prospective study of patients undergoing 68Ga-DOTATATE PET/CT, 111In-pentetreotide single-photon emission computed tomography (SPECT)/CT and multiphasic CT scan, and/or magnetic resonance imaging in a blinded fashion with comprehensive biochemical testing. The primary outcome measure was the detection of lesions by each imaging study. Results 68Ga-DOTATATE PET/CT imaging detected 95.1% of lesions (95% CI, 92.4% to 96.8%) with an average maximum standardized uptake value of 65.4 ± 47 (range, 6.9 to 244), anatomic imaging detected 45.3% of lesions (95% CI, 37.9% to 52.9%), and 111In-pentetreotide SPECT/CT detected 30.9% of lesions (95% CI, 25.0% to 37.5%), with a significant difference between imaging modalities (P < .001). In four of 14 patients (28.6%), 68Ga-DOTATATE PET/CT found a previously unknown primary tumor, and detected primary GEPNET, lymph node, and distant metastases correctly in 72 of 113 lesions (63.7%) when compared with histopathology, with 22.1% and 38.9% detected by using 111In-pentetreotide SPECT/CT and anatomic imaging, respectively. On the basis of findings with 68Ga-DOTATATE PET/CT, 43 of 131 patients (32.8%) had a change in management recommendation. In patients with carcinoid symptoms but negative biochemical testing, 68Ga-DOTATATE PET/CT detected lesions in 65.2% of patients, 40% of which were detected neither by anatomic imaging nor by 111In-pentetreotide SPECT/CT. Conclusion

  9. Charged-particle emission tomography.

    PubMed

    Ding, Yijun; Caucci, Luca; Barrett, Harrison H

    2017-06-01

    Conventional charged-particle imaging techniques - such as autoradiography - provide only two-dimensional (2D) black ex vivo images of thin tissue slices. In order to get volumetric information, images of multiple thin slices are stacked. This process is time consuming and prone to distortions, as registration of 2D images is required. We propose a direct three-dimensional (3D) autoradiography technique, which we call charged-particle emission tomography (CPET). This 3D imaging technique enables imaging of thick tissue sections, thus increasing laboratory throughput and eliminating distortions due to registration. CPET also has the potential to enable in vivo charged-particle imaging with a window chamber or an endoscope. Our approach to charged-particle emission tomography uses particle-processing detectors (PPDs) to estimate attributes of each detected particle. The attributes we estimate include location, direction of propagation, and/or the energy deposited in the detector. Estimated attributes are then fed into a reconstruction algorithm to reconstruct the 3D distribution of charged-particle-emitting radionuclides. Several setups to realize PPDs are designed. Reconstruction algorithms for CPET are developed. Reconstruction results from simulated data showed that a PPD enables CPET if the PPD measures more attributes than just the position from each detected particle. Experiments showed that a two-foil charged-particle detector is able to measure the position and direction of incident alpha particles. We proposed a new volumetric imaging technique for charged-particle-emitting radionuclides, which we have called charged-particle emission tomography (CPET). We also proposed a new class of charged-particle detectors, which we have called particle-processing detectors (PPDs). When a PPD is used to measure the direction and/or energy attributes along with the position attributes, CPET is feasible. © 2017 The Authors. Medical Physics published by Wiley Periodicals

  10. Broadband chemical species tomography: Measurement theory and a proof-of-concept emission detection experiment

    NASA Astrophysics Data System (ADS)

    Grauer, Samuel J.; Tsang, Roger W.; Daun, Kyle J.

    2017-09-01

    This work introduces broadband-absorption based chemical species tomography (CST) as a novel approach to reconstruct hydrocarbon concentrations from open-path attenuation measurements. In contrast to monochromatic CST, which usually involves solving a mathematically ill-posed linear problem, the measurement equations in broadband CST are nonlinear due to the integration of the radiative transfer equation over the detection spectrum. We present a transfer function that relates broadband transmittances to a path-integrated concentration, suitable for tomographic reconstruction, and use a Bayesian reconstruction technique that combines the measurement data with a priori assumptions about the spatial distribution of the target species. The technique is demonstrated by reconstructing a propane plume, and validating the results by point concentration measurements made with a flame ionization detector.

  11. Detection of bone marrow involvement in newly diagnosed post-transplant lymphoproliferative disorder: (18)F-fluorodeoxyglucose positron emission tomography/computed tomography versus bone marrow biopsy.

    PubMed

    Gheysens, Olivier; Thielemans, Sanne; Morscio, Julie; Boeckx, Nancy; Goffin, Karolien E; Deroose, Christophe M; Sagaert, Xavier; Wlodarska, Iwona; Verhoef, Gregor; Dierickx, Daan; Tousseyn, Thomas

    2016-10-01

    Detecting bone marrow involvement (BMI) in lymphoma is important as it adversely affects stage. Bone marrow biopsy (BMB) remains the standard to detect BMI but is prone to sampling error. We retrospectively investigated whether (18)F-fluorodeoxyglucose positron emission tomography with computed tomography ((18)F-FDG-PET/CT) could identify BMI in patients with post-transplant lymphoproliferative disorder (PTLD) with sufficient accuracy in comparison with staging BMB. Twenty-five patients diagnosed with PTLD who underwent (18)F-FDG-PET/CT and BMB within one month were evaluated. Based on our criteria, six patients (24%) were considered positive for BMI on (18)F-FDG-PET/CT compared to one by BMB. Although we cannot completely exclude false positive results on (18)F-FDG-PET/CT, our data indicate a significantly higher sensitivity of (18)F-FDG-PET/CT compared to BMB (100% vs 17%) but similar specificity. These data confirm the high diagnostic performance of (18)F-FDG-PET/CT for detecting BMI, but prospective studies are needed to determine whether (18)F-FDG-PET/CT could indeed replace staging BMB in PTLD.

  12. The value of positron emission tomography scanning in the detection of subclinical metastatic melanoma.

    PubMed

    Acland, K M; O'Doherty, M J; Russell-Jones, R

    2000-04-01

    We have undertaken a retrospective analysis of all positron emission tomography (PET) scans carried out at St Thomas' Hospital, London, since 1994 to establish the sensitivity and specificity of this radiologic technique in cutaneous malignant melanoma. In particular, we have identified those patients with primary cutaneous malignant melanoma in whom PET scanning revealed in-transit or regional spread to nodes and those patients with known regional spread in whom PET scanning revealed distant metastases. We defined our false-negative results as a negative scan result with positive histology or subsequent clinical progression of disease. False-positive results were defined as a suspect scan with negative histology or no subsequent progression of disease. PET scanning had an overall sensitivity of 78% and specificity of 87%; however, subset analysis (M. D. Anderson staging system) showed a sensitivity of 50% for stage I disease (34 patients and 35 scans) and 33% for stage II disease (9 patients and 9 scans) with specificities of 87% and 100%, respectively. For stage III disease (16 patients and 17 scans), PET showed a sensitivity of 93% and specificity of 50%. Overall, 35% of patients with true-positive scans had their disease restaged. We can conclude therefore that PET is valuable as a staging procedure in patients with known regional spread but is suboptimal in the prediction of outcome in stage I or stage II disease.

  13. Positron emission tomography wrist detector

    DOEpatents

    Schlyer, David J.; O'Connor, Paul; Woody, Craig; Junnarkar, Sachin Shrirang; Radeka, Veljko; Vaska, Paul; Pratte, Jean-Francois

    2006-08-15

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal representing a time-of-occurrence of an annihilation event, generating an address signal representing a channel detecting the annihilation event, and generating a channel signal including the time and address signals. The method also includes generating a composite signal including the channel signal and another similarly generated channel signal concerning another annihilation event. An apparatus that serially transfers annihilation information includes a time signal generator, address signal generator, channel signal generator, and composite signal generator. The time signal is asynchronous and the address signal is synchronous to a clock signal. A PET scanner includes a scintillation array, detection array, front-end array, and a serial encoder. The serial encoders include the time signal generator, address signal generator, channel signal generator, and composite signal generator.

  14. Inflammation is Related to Coronary Flow Reserve Detected by Positron Emission Tomography in Asymptomatic Male Twins

    PubMed Central

    Vaccarino, Viola; Khan, Durreshahwar; Votaw, John; Faber, Tracy; Veledar, Emir; Jones, Dean P.; Goldberg, Jack; Raggi, Paolo; Quyyumi, Arshed A.; Bremner, J. Douglas

    2011-01-01

    Objectives To examine the relationship between inflammation and coronary microvascular function in asymptomatic individuals using positron emission tomography (PET) and assessment of coronary flow reserve (CFR). Background Coronary microvascular dysfunction is an early precursor of coronary artery disease (CAD) thought to result from endothelial cell activation and inflammation, but data are limited. Methods We examined 268 asymptomatic male monozygotic and dizygotic twins. Plasma biomarkers of inflammation and endothelial cell activation included C-reactive protein (CRP), interleukin-6 (IL-6), white blood cell count (WBC), vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Blood flow quantitation was obtained with [13N] ammonia PET at rest and after adenosine stress. CFR was measured as the ratio of maximum flow to baseline flow at rest; abnormal CFR was defined as a ratio <2.5. A summed stress score for visible perfusion defects was calculated. Results In within-pair analyses, all biomarkers, except VCAM-1, were higher in twins with lower CFR than their brothers with higher CFR (p<0.05). This was observed in the entire sample, as well as within pairs discordant for a CFR of <2.5. Associations persisted after adjusting for summed stress score and CAD risk factors. In contrast no biomarker, except IL-6, was related to the summed stress score of visible defects. Conclusions Even in asymptomatic subjects, a decrease in coronary microvascular function is accompanied by a systemic inflammatory response, independent of CAD risk factors. Our results, using a controlled twin design, highlight the importance of coronary microvascular function in the early phases of CAD. PMID:21392641

  15. Inflammation is related to coronary flow reserve detected by positron emission tomography in asymptomatic male twins.

    PubMed

    Vaccarino, Viola; Khan, Durreshahwar; Votaw, John; Faber, Tracy; Veledar, Emir; Jones, Dean P; Goldberg, Jack; Raggi, Paolo; Quyyumi, Arshed A; Bremner, J Douglas

    2011-03-15

    This study sought to examine the relationship between inflammation and coronary microvascular function in asymptomatic individuals using positron emission tomography (PET) and assessment of coronary flow reserve (CFR). Coronary microvascular dysfunction is an early precursor of coronary artery disease (CAD) thought to result from endothelial cell activation and inflammation, but data are limited. We examined 268 asymptomatic male monozygotic and dizygotic twins. Plasma biomarkers of inflammation and endothelial cell activation included C-reactive protein (CRP), interleukin (IL)-6, white blood cell count (WBC), vascular cell adhesion molecule (VCAM)-1, and intercellular adhesion molecule (ICAM)-1. Blood flow quantitation was obtained with [¹³N] ammonia PET at rest and after adenosine stress. CFR was measured as the ratio of maximum flow to baseline flow at rest; abnormal CFR was defined as a ratio < 2.5. A summed stress score for visible perfusion defects was calculated. In within-pair analyses, all biomarkers, except VCAM-1, were higher in twins with lower CFR than their brothers with higher CFR (p < 0.05). This was observed in the entire sample, as well as within pairs discordant for a CFR of <2.5. Associations persisted after adjusting for summed stress score and CAD risk factors. In contrast no biomarker, except IL-6, was related to the summed stress score of visible defects. Even in asymptomatic subjects, a decrease in coronary microvascular function is accompanied by a systemic inflammatory response, independent of CAD risk factors. Our results, using a controlled twin design, highlight the importance of coronary microvascular function in the early phases of CAD. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  16. [Tau Positron Emission Tomography].

    PubMed

    Higuchi, Makoto

    2017-07-01

    Accumulation of fibrillar tau protein aggregates is a neuropathological hallmark of Alzheimer's disease (AD) and related neurodegenerative dementias, including a subgroup of frontotemporal lobar degeneration (FTLD). Visualization of tau lesions in the brains of living subjects enables a pathology-based diagnosis of dementing illnesses in the prodromal stage, and offers objective measures of disease progression and outcomes of disease-modifying therapies. With this rationale, diverse classes of low-molecular-weight chemicals capable of binding to a β-pleated sheet structure have been developed to be used for in vivo positron emission tomography (PET) of tau pathologies. Clinical PET studies of AD patients with such tau probes have provided the following insights: (1) Tau fibrils accumulate in the hippocampal formation in an age-dependent manner that is independent of amyloid-beta peptide (Aβ) pathology; (2) The deposition of Aβ may trigger a spatial expansion of tau pathology, in transition from normal aging to advanced AD; and (3) Tau accumulation is intimately associated with local neuronal loss, leading to cortical atrophy and focal symptoms. In contrast, studies of FTLD have shown a limited performance of first-generation PET probes in capturing non-AD-type tau lesions. New compounds have accordingly been developed and clinically tested, proving to yield a high contrast for tau deposits with high specificity. These second-generation probes are being evaluated primarily by pharmaceutical companies, in line with their growing demands for neuroimaging-based biomarkers serving for clinical trials of anti-Aβ and anti-tau therapies. Meanwhile, a consortium flexibly linking academia and industry to facilitate the utilization of research tools, including tau PET probes, has been established in Japan, for the ultimate purpose of elucidating the molecular etiology of tauopathies and creating diagnostic and therapeutic agents based on such an understanding.

  17. Comparison of rubidium-82 positron emission tomography and thallium-201 SPECT imaging for detection of coronary artery disease

    SciTech Connect

    Stewart, R.E.; Schwaiger, M.; Molina, E.; Popma, J.; Gacioch, G.M.; Kalus, M.; Squicciarini, S.; al-Aouar, Z.R.; Schork, A.; Kuhl, D.E. )

    1991-06-15

    The diagnostic performance of rubidium-82 (Rb-82) positron emission tomography (PET) and thallium-201 (Tl-201) single-photon emission-computed tomography (SPECT) for detecting coronary artery disease was investigated in 81 patients (52 men, 29 women). PET studies using 60 mCi of Rb-82 were performed at baseline and after intravenous infusion of 0.56 mg/kg dipyridamole in conjunction with handgrip stress. Tl-201 SPECT was performed after dipyridamole-handgrip stress and, in a subset of patients, after treadmill exercise. Sensitivity, specificity and overall diagnostic accuracy were assessed using both visually and quantitatively interpreted coronary angiograms. The overall sensitivity, specificity and accuracy of PET for detection of coronary artery disease (greater than 50% diameter stenosis) were 84, 88 and 85%, respectively. In comparison, the performance of SPECT revealed a sensitivity of 84%, specificity of 53% (p less than 0.05 vs PET) and accuracy of 79%. Similar results were obtained using either visual or quantitative angiographic criteria for severity of coronary artery disease. In 43 patients without prior myocardial infarction, the sensitivity for detection of disease was 71 and 73%, respectively, similar for both PET and SPECT. There was no significant difference in diagnostic performance between imaging modalities when 2 different modes of stress (exercise treadmill vs intravenous dipyridamole plus handgrip) were used with SPECT imaging. Thus, Rb-82 PET provides improved specificity compared with Tl-201 SPECT for identifying coronary artery disease, most likely due to the higher photon energy of Rb-82 and attenuation correction provided by PET. However, post-test referral cannot be entirely excluded as a potential explanation for the lower specificity of Tl-201 SPECT.

  18. Pancreatic cancer detected by positron emission tomography with 18F-labelled deoxyglucose: method and first results.

    PubMed

    Bares, R; Klever, P; Hellwig, D; Hauptmann, S; Fass, J; Hambuechen, U; Zopp, L; Mueller, B; Buell, U; Schumpelick, V

    1993-07-01

    In order to evaluate the utility of positron emission tomography (PET) with 18F-labelled deoxyglucose (FDG) for detection of pancreatic cancer 15 patients with pancreatic masses shown by computed tomography were investigated. Static PET scans covering an axial field of view of 15 cm were obtained 45 min after intravenous injection of 150-300 MBq FDG. Focally increased FDG accumulation was present in 12 out of 13 patients with histologically proven adenocarcinoma, in particular in eight of nine lymph node and four of five liver metastases. Scans of two patients with chronic pancreatitis confirmed by surgery revealed a normal FDG distribution. Contrast between tumour and normal tissue depended the metabolic situation prior to FDG injection. High ratios were found in fasting patients whereas no elevated FDG uptake was measured in an insulin-dependent diabetic suffering from carcinoma of the pancreatic head. We conclude that FDG PET might have the potential for detection and even differentiation of pancreatic carcinoma from chronic pancreatitis. Further studies are necessary to substantiate these preliminary findings and to optimize results in diabetic patients.

  19. Effect of furosemide administration before F-18 fluorodeoxyglucose positron emission tomography/computed tomography on urine radioactivity and detection of uterine cervical cancer.

    PubMed

    d'Amico, Andrea; Gorczewska, Izabela; Gorczewski, Kamil; Turska-d'Amico, Maria; Di Pietro, Marco

    2014-01-01

    In evaluating uterine cervical cancer with ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), there may be overlap between the FDG activity at tumor sites and nonspecific radioactivity in the urine. We evaluated the efficacy of furosemide premedication with routine hydration to obtain better contrast and less overlap between cervical cancer and the urinary bladder. We retrospectively evaluated 166 patients who had primary or relapsed cervical cancer and underwent FDG PET/CT scanning with (133 patients) or without (33 patients) furosemide premedication (10 mg intravenous, slowly injected 30 min before the scan). We calculated bladder and tumor maximum and median standardized uptake value (SUVmax and SUVmed), and overlap between tumor and urinary activity was detected visually. Overlap between urinary and tumor radioactivity was observed in 8 of 133 scans (6%) in patients who receive furosemide and in 3 of 33 scans (9%) in patients who did not receive furosemide. The SUVmax and SUVmed for the bladder were significantly lower in patients who were pretreated with furosemide (SUVmax, 6.3; SUVmed, 4.6) than patients who were not pretreated with furosemide (SUVmax, 8.8 [P ≤ 0.008]; SUVmed, 6.5 [P ≤ 0.002]). The tumor SUVmax and SUVmed were similar between the patient groups. Furosemide premedication before FDG PET/CT scanning may enable improved evaluation of activity and extension of cervical cancer.

  20. The utility of [18F] fluorodeoxyglucose-positron emission tomography/computed tomography for detecting lung and esophagus multiple primary cancers involved in the larynx: Two case reports.

    PubMed

    Wang, Qinying; Chai, Liang; Zhou, Shuihong

    2015-01-01

    Multiple primary cancers involved in the larynx of differentiating synchronous multiple primary cancers from metastasis can often be very difficult, especially when they have the same histology. However, it is very important because the therapeutic approach is completely different. Clinical situations like this appear to be increasing as a result of the recent popular use of [18F] fluorodeoxyglucose-positron emission tomography/computed tomography. Herein, we report two cases of multiple primary cancers involved in the larynx.

  1. The Rate and Clinical Significance of Incidental Thyroid Uptake as Detected by Gallium-68 DOTATATE Positron Emission Tomography/Computed Tomography

    PubMed Central

    Nockel, Pavel; Millo, Corina; Keutgen, Xavier; Klubo-Gwiezdzinska, Joanna; Shell, Jasmine; Patel, Dhaval; Nilubol, Naris; Herscovitch, Peter; Sadowski, Samira M.

    2016-01-01

    Background: Gallium-68 (Ga-68) DOTATATE is a radiolabeled peptide–imaging modality that targets the somatostatin receptor (SSTR), especially subtype 2 (SSTR2). Benign and malignant thyroid tumors have been observed to express SSTR. The aim of this study was to evaluate the frequency and clinical significance of incidental atypical thyroid uptake as detected by Ga-68 DOTATATE positron emission tomography/computed tomography (PET/CT). Methods: A retrospective analysis was conducted of a prospective study in which 237 patients underwent Ga-68 DOTATATE PET/CT as part of a work-up for metastatic and unknown primary neuroendocrine tumors. The types of uptake in the thyroid gland (focal/diffuse) and maximum standardized uptake value (SUVmax) levels were evaluated and compared with the background uptake in the liver and salivary glands. Results: Of 237 patients, 26 (11%) had atypical thyroid uptake as detected by Ga-68 DOTATATE PET/CT. There were no significant clinical or biochemical variables associated with atypical thyroid uptake. Fourteen (54%) patients had positive focal uptake, and 12 (46%) patients had diffuse uptake. Of the 14 patients with atypical focal uptake, 10 (71%) had thyroid nodules on the corresponding side, as detected by anatomic imaging. Three of 10 patients (21%) were found to have papillary thyroid cancer, and seven (70%) had adenomatoid nodules. Of the 12 patients with diffuse increased uptake, six (50%) had a history of hypothyroidism, five (42%) had chronic lymphocytic thyroiditis, and one (8%) had nontoxic multinodular goiter. Conclusions: Patients with an incidental focal abnormal thyroid uptake on Ga-68 DOTATATE PET/CT scan should have further clinical evaluation to exclude a diagnosis of thyroid cancer. PMID:27094616

  2. Application of the Intraoperative Dual Photon Emission Computed Tomography System in Sentinel Lymph Node Detection: A Simulation Study

    NASA Astrophysics Data System (ADS)

    Lin, Chang-Shiun; Lin, Hsin-Hon.; Ni, Yu-Ching; Jan, Meei-Ling.; Lu, Kuan-Pai; Chuang, Keh-Shih

    2016-02-01

    The sentinel lymph node (SLN) hypothesis is applied as part of the standard procedure for identifying early-stage breast cancer. Thus, an imaging system that can locate SLNs in operating rooms is desired. Many 2-D probe imaging systems and a freehand single-photon emission-computed tomography (fhSPECT) system have been proposed. However, 2-D probe imaging systems are affected by shine-through and shadowing effects. Here, we propose an alternative to 3-D imaging systems, i.e., a dual-photon emission computed tomography (DuPECT) system, which integrates both preoperative and intraoperative information to locate SLNs using cascade isotopes such as Se-75. The system consists of a LaBr3-based probe and planar head, a collimation system, and a coincidence circuit. For each disintegration, the slat and parallel-hole collimator define a plane and a line, respectively, which represent the possible flight paths of each photon. SLNs can be located using the line-plane intersection. Here, the performance is evaluated using Monte Carlo software developed in our laboratory, integrated with SimSET and GATE software. A measurement study indicates that the randoms rate increases with increased initial activities, while the scatter rate is lower than 1.2 count/s for various activities. In a simulated imaging study, four injection sites and two LNs placed at various depths are minimally distinguishable. However, the LNs are clearly identifiable in the absence of injection sites. Our results indicate that the proposed three-dimensional imaging system has the potential to identify injection sites and various SLNs. However, difficulties with low sensitivity for LN detection, especially in the presence of activity from injection sites, and the choice of appropriate radioisotope must be overcome for its clinical usage.

  3. Role of F-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of recurrence in patients with cervical cancer.

    PubMed

    Bhoil, Amit; Mittal, Bhagwant Rai; Bhattacharya, Anish; Santhosh, Sampath; Patel, Firuza

    2013-10-01

    Treatment of cervical cancer is usually surgery in the early stages and radiotherapy or chemoradiotherapy in more advanced stages of the disease. Recurrence may occur in multiple sites following primary treatment. Although recurrent metastatic disease is not curable, surgical treatment may be of great help if locoregional recurrence is detected early. Fluorine-18 Fluorodeoxyglucose positron emission tomography - computed tomography (F-18 FDG PET/CT) forms an important part of investigations in the diagnosis of clinically suspicious recurrent cervical cancer. To assess the role of F-18 FDG PET/CT in diagnosing recurrence in patients with clinical suspicion of recurrent cervical cancer. We retrospectively evaluated 53 histopathologically proved patients of cervical cancer. All the patients had been treated with either surgery/radiation therapy with or without chemotherapy. The standard PET/CT acquisition protocol, with delayed post void static pelvic images, wherever required, was followed in all patients. Significant uptake of FDG in the lymph nodes was considered to be a recurrence suggestive of metastasis. Para-aortic lymph nodal involvement was considered to be distant metastasis. Any significant uptake in the lung nodule on FDG PET was evaluated either by histological confirmation, by taking fine needle aspiration cytology (FNAC), or by a follow-up chest CT done after three months. Of the 53 patients with clinically equivocal recurrence, FDG PET/CT suggested recurrence in 41 patients (local recurrence in 14 patients and distant recurrence/metastasis with or without local recurrence in 27 patients). It had a sensitivity of 97.5%, a specificity of 63.6%, positive predictive value of 90.9%, and negative predictive value of 87.5%. PET/CT appears to have an important role in detecting recurrence following primary treatment of cervical cancer. The high positive and negative predictive values of PET/CT may be helpful in planning management of recurrent cervical cancer.

  4. Risk of node metastasis of sentinel lymph nodes detected in level II/III of the axilla by single-photon emission computed tomography/computed tomography

    PubMed Central

    SHIMA, HIROAKI; KUTOMI, GORO; SATOMI, FUKINO; MAEDA, HIDEKI; TAKAMARU, TOMOKO; KAMESHIMA, HIDEKAZU; OMURA, TOSEI; MORI, MITSURU; HATAKENAKA, MASAMITSU; HASEGAWA, TADASHI; HIRATA, KOICHI

    2014-01-01

    In breast cancer, single-photon emission computed tomography/computed tomography (SPECT/CT) shows the exact anatomical location of sentinel nodes (SN). SPECT/CT mainly exposes axilla and partly exposes atypical sites of extra-axillary lymphatic drainage. The mechanism of how the atypical hot nodes are involved in lymphatic metastasis was retrospectively investigated in the present study, particularly at the level II/III region. SPECT/CT was performed in 92 clinical stage 0-IIA breast cancer patients. Sentinel lymph nodes are depicted as hot nodes in SPECT/CT. Patients were divided into two groups: With or without hot node in level II/III on SPECT/CT. The existence of metastasis in level II/III was investigated and the risk factors were identified. A total of 12 patients were sentinel lymph node biopsy metastasis positive and axillary lymph node dissection (ALND) was performed. These patients were divided into two groups: With and without SN in level II/III, and nodes in level II/III were pathologically proven. In 11 of the 92 patients, hot nodes were detected in level II/III. There was a significant difference in node metastasis depending on whether there were hot nodes in level II/III (P=0.0319). Multivariate analysis indicated that the hot nodes in level II/III and lymphatic invasion were independent factors associated with node metastasis. There were 12 SN-positive patients followed by ALND. In four of the 12 patients, hot nodes were observed in level II/III. Two of the four patients with hot nodes depicted by SPECT/CT and metastatic nodes were pathologically evident in the same lesion. Therefore, the present study indicated that the hot node in level II/III as depicted by SPECT/CT may be a risk of SN metastasis, including deeper nodes. PMID:25289038

  5. Sensitivity of post treatment positron emission tomography/computed tomography to detect inter-fractional range variations in scanned ion beam therapy.

    PubMed

    Handrack, Josefine; Tessonnier, Thomas; Chen, Wenjing; Liebl, Jakob; Debus, Jürgen; Bauer, Julia; Parodi, Katia

    2017-09-18

    Ion therapy, especially with modern scanning beam delivery, offers very sharp dose gradients for highly conformal cancer treatment. However, it is very sensitive to uncertainties of tissue stopping properties as well as to anatomical changes and setup errors, making range verification highly desirable. To this end, positron emission tomography (PET) can be used to measure decay products of β(+)-emitters created in interactions inside the patient. This work investigates the sensitivity of post treatment PET/CT (computed tomography) to detect inter-fractional range variations. Fourteen patients of different indication underwent PET/CT monitoring after selected treatment fractions with scanned proton or carbon ion beams. In addition to PET/CT measurements, PET and dose distributions were simulated on different co-registered CT data. Pairs of PET data were then analyzed in terms of longitudinal shifts along the beam path, as surrogate of inter-fractional range deviations. These findings were compared to changes of dose-volume-histogram indexes and corresponding dose as well as CT shifts to disentangle the origin of possible PET shifts. Biological washout modeling (PET simulations) and low (<55 Bq/ml) activity concentrations (offline PET measurements, especially for (12)C ions) were the main limitations for clinical treatment verification. For two selected cases, the benefit of improved washout modeling based on organ segmentation could be demonstrated. Overall, inter-fractional range shifts up to ±3 mm could be deduced from both PET measurements and simulations, and found well correlated (typically within 1.8 mm) to anatomical changes derived from CT scans, in agreement with dose data. Despite known limitations of post treatment PET/CT imaging, this work indicates its potential for assessing inter-fractional changes and points to future developments for improved PET-based treatment verification.

  6. Risk of node metastasis of sentinel lymph nodes detected in level II/III of the axilla by single-photon emission computed tomography/computed tomography.

    PubMed

    Shima, Hiroaki; Kutomi, Goro; Satomi, Fukino; Maeda, Hideki; Takamaru, Tomoko; Kameshima, Hidekazu; Omura, Tosei; Mori, Mitsuru; Hatakenaka, Masamitsu; Hasegawa, Tadashi; Hirata, Koichi

    2014-11-01

    In breast cancer, single-photon emission computed tomography/computed tomography (SPECT/CT) shows the exact anatomical location of sentinel nodes (SN). SPECT/CT mainly exposes axilla and partly exposes atypical sites of extra-axillary lymphatic drainage. The mechanism of how the atypical hot nodes are involved in lymphatic metastasis was retrospectively investigated in the present study, particularly at the level II/III region. SPECT/CT was performed in 92 clinical stage 0-IIA breast cancer patients. Sentinel lymph nodes are depicted as hot nodes in SPECT/CT. Patients were divided into two groups: With or without hot node in level II/III on SPECT/CT. The existence of metastasis in level II/III was investigated and the risk factors were identified. A total of 12 patients were sentinel lymph node biopsy metastasis positive and axillary lymph node dissection (ALND) was performed. These patients were divided into two groups: With and without SN in level II/III, and nodes in level II/III were pathologically proven. In 11 of the 92 patients, hot nodes were detected in level II/III. There was a significant difference in node metastasis depending on whether there were hot nodes in level II/III (P=0.0319). Multivariate analysis indicated that the hot nodes in level II/III and lymphatic invasion were independent factors associated with node metastasis. There were 12 SN-positive patients followed by ALND. In four of the 12 patients, hot nodes were observed in level II/III. Two of the four patients with hot nodes depicted by SPECT/CT and metastatic nodes were pathologically evident in the same lesion. Therefore, the present study indicated that the hot node in level II/III as depicted by SPECT/CT may be a risk of SN metastasis, including deeper nodes.

  7. Clinical importance of [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography in the management of patients with bronchoalveolar carcinoma: Role in the detection of recurrence.

    PubMed

    Skoura, Evangelia; Datseris, Ioannis E; Exarhos, Dimitrios; Chatziioannou, Sophia; Oikonomopoulos, Georgios; Samartzis, Alexandros; Giannopoulou, Chariklia; Syrigos, Konstantinos N

    2013-05-01

    [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) has been reported to have a low sensitivity in the initial diagnosis of bronchoalveolar carcinoma (BAC) due to BAC's low metabolic activity. The aim of this study was to assess the value of [(18)F]FDG-PET/CT in the detection of BAC recurrence. Between February 2007 and September 2011, the [(18)F]FDG-PET/CT scans that were performed on patients with known, histologically proven BAC were studied. A total of 24 [(18)F]FDG-PET/CT scans were performed in 22 patients, including 16 males and 6 females, with a mean age of 65±9 years. Among the scans, 15 were performed to assess for possible recurrence with equivocal findings in conventional imaging methods and 9 for restaging post-therapy. In all cases conventional imaging studies (CT and MRI) were performed 5-30 days prior to PET/CT. Among the 24 [(18)F]FDG-PET/CT scans, 18 were positive and 6 negative. Among the 15 [(18)F]FDG-PET/CT scans performed for suspected recurrence, 34 lesions were detected and the mean maximum standardized uptake value (SUVmax) was 6.8±3.26. In nine scans, upstaging was observed, while two were in agreement with the findings of the conventional modalities. A greater number of lesions were detected in two scans and fewer lesions were detected in one, with no change in staging. Only one scan was negative. By contrast, in patients examined for restaging, there were only five lesions with a mean SUVmax of 4.86±3.18. Agreement between the findings of [(18)F]FDG-PET/CT and the conventional modalities was observed in 8 out of 9 cases. Although [(18)F]FDG-PET/CT has been reported to have a low sensitivity in the initial diagnosis of BAC, the present results indicate that when there is recurrence, the lesions become [(18)F]FDG avid. [(18)F]FDG-PET/CT may provide further information in patients evaluated for recurrence and thus improve patient management.

  8. Skeletal muscle metastases as the initial manifestation of an unknown primary lung cancer detected on F-18 fluorodeoxyglucose positron emission tomography/computed tomography.

    PubMed

    Agrawal, Kanhaiyalal; Bhattacharya, Anish; Singh, Navneet; Harisankar, Chidambaram Natarajan Balasubramanian; Mittal, Bhagwant Rai

    2013-01-01

    Skeletal muscle metastasis as the initial presentation of the unknown primary lung cancer is unusual. A 65-year-old male patient presented with pain and swelling of the right forearm. Fine needle aspiration of the swelling revealed metastatic squamous cell carcinoma. The patient underwent whole body F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) to identify the site of the primary malignancy. The authors present PET/CT images showing FDG-avid metastases to the skeletal muscles along with a previously unknown primary tumor in the right lung, in a patient presenting with initial muscular symptoms without any pulmonary manifestations.

  9. Detection of submicron scale cracks and other surface anomalies using positron emission tomography

    DOEpatents

    Cowan, Thomas E.; Howell, Richard H.; Colmenares, Carlos A.

    2004-02-17

    Detection of submicron scale cracks and other mechanical and chemical surface anomalies using PET. This surface technique has sufficient sensitivity to detect single voids or pits of sub-millimeter size and single cracks or fissures of millimeter size; and single cracks or fissures of millimeter-scale length, micrometer-scale depth, and nanometer-scale length, micrometer-scale depth, and nanometer-scale width. This technique can also be applied to detect surface regions of differing chemical reactivity. It may be utilized in a scanning or survey mode to simultaneously detect such mechanical or chemical features over large interior or exterior surface areas of parts as large as about 50 cm in diameter. The technique involves exposing a surface to short-lived radioactive gas for a time period, removing the excess gas to leave a partial monolayer, determining the location and shape of the cracks, voids, porous regions, etc., and calculating the width, depth, and length thereof. Detection of 0.01 mm deep cracks using a 3 mm detector resolution has been accomplished using this technique.

  10. 21 CFR 892.1200 - Emission computed tomography system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Emission computed tomography system. 892.1200 Section 892.1200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... system. (a) Identification. An emission computed tomography system is a device intended to detect...

  11. 21 CFR 892.1200 - Emission computed tomography system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Emission computed tomography system. 892.1200 Section 892.1200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... system. (a) Identification. An emission computed tomography system is a device intended to detect...

  12. 21 CFR 892.1200 - Emission computed tomography system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Emission computed tomography system. 892.1200 Section 892.1200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... system. (a) Identification. An emission computed tomography system is a device intended to detect...

  13. 21 CFR 892.1200 - Emission computed tomography system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Emission computed tomography system. 892.1200 Section 892.1200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... system. (a) Identification. An emission computed tomography system is a device intended to detect...

  14. Highly Sensitive Detection of Minimal Cardiac Ischemia using Positron Emission Tomography Imaging of Activated Platelets

    PubMed Central

    Ziegler, Melanie; Alt, Karen; Paterson, Brett M.; Kanellakis, Peter; Bobik, Alex; Donnelly, Paul S.; Hagemeyer, Christoph E.; Peter, Karlheinz

    2016-01-01

    A reliable method for the diagnosis of minimal cardiac ischemia would meet a strong demand for the sensitive diagnosis of coronary artery disease in cardiac stress testing and risk stratification in patients with chest pain but unremarkable ECGs and biomarkers. We hypothesized that platelets accumulate early on in ischemic myocardium and a newly developed technology of non-invasive molecular PET imaging of activated platelets can thus detect minimal degrees of myocardial ischemia. To induce different degrees of minimal cardiac ischemia, the left anterior descending artery (LAD) was ligated for 10, 20 or 60 min. Mice were injected with a newly generated scFvanti-GPIIb/IIIa-64CuMeCOSar radiotracer, composed of a single-chain antibody that only binds to activated integrin GPIIb/IIIa (αIIbβIII) and thus to activated platelets, and a sarcophagine cage MeCOSar complexing the long half-life PET tracer copper-64. A single PET/CT scan was performed. Evans Blue/TTC staining to detect necrosis as well as classical serological biomarkers like Troponin I and heart-type fatty acid-binding protein (H-FABP) were negative, whereas PET imaging of activated platelets was able to detect small degrees of ischemia. Taken together, molecular PET imaging of activated platelets represents a unique and highly sensitive method to detect minimal cardiac ischemia. PMID:27909290

  15. Positron emission tomography (PET) for cholangiocarcinoma

    PubMed Central

    Breitenstein, S.; Apestegui, C.

    2008-01-01

    The combination of positron emission tomography (PET) with computed tomography (PET-CT) provides simultaneous metabolic and anatomic information on tumors in the same imaging session. Sensitivity of PET/PET-CT is higher for intrahepatic (>90%) than for extrahepatic cholangiocarcinoma (CCA) (about 60%). The detection rate of distant metastasis is 100%. PET, and particularly PET-CT, improves the results and impacts on the oncological management in CCA compared with other imaging modalities. Therefore, PET-CT is recommended in the preoperative staging of intrahepatic (strength of recommendation: moderate) and extrahepatic (strength of recommendation: low) CCA. PMID:18773069

  16. Simultaneous reconstruction and edge detection of transmission images in emission computed tomography

    NASA Astrophysics Data System (ADS)

    Lee, Soo-Jin

    2001-12-01

    This paper presents a Bayesian method for reconstructing transmission images, which provide attenuation correction factors for emission scans. In order to preserve the edges that bound anatomical regions, which are important especially for areas of non-uniform attenuation, we use the line-process model as a prior. Our prior model provides edge maps containing the anatomical boundary information as well as edge preserved reconstructions. To optimize our nonconvex objective function, we use our previously developed deterministic annealing algorithm, in which the energy function is approximated by a sequence of smooth functions that converges uniformly to the original energy function. To accelerate the convergence speed of our algorithm, we apply the ordered subsets principle to the deterministic annealing algorithm. We also show how the smoothing parameter can be adjusted to account for the effects of using ordered subsets so that the degree of smoothness can be retained for variations of the number of subsets. To validate the quantitative performance of our algorithm, we use the quantitation of bias/variance over noise trials. Our preliminary results indicate that, in some circumstances, our methods have advantages over conventional methods.

  17. A Restless Leg Syndrome Incidentally Detected by an 18F-FDG Positron Emission Tomography.

    PubMed

    Ohnona, Jessica; Metlaine, Arnaud; Leger, Damien; Talbot, Jean-Noël

    2017-05-01

    A case of a restless leg syndrome (RLS) was incidentally detected in a 49-year-old woman referred for an F-FDG PET/CT in monitoring her breast cancer. She was treated with chemotherapy and on long-term hormone therapy. Diffuse F-FDG uptake of calf muscles was visualized. Medical history revealed that the patient felt leg cramps in supine position, suggesting RLS. The diagnosis was confirmed using clinical rating scales and polysomnography. RLS being underdiagnosed, this type of FDG PET/CT incidental finding should prompt to check the presence of evocative symptoms and refer the patient to a physician specialized in sleep disorders.

  18. Positron emission tomography with C11-acetate for tumor detection and localization in patients with prostate-specific antigen relapse after radical prostatectomy.

    PubMed

    Sandblom, Gabriel; Sörensen, Jens; Lundin, Niclas; Häggman, Michael; Malmström, Per-Uno

    2006-05-01

    To evaluate positron emission tomography with C11-acetate as a method for detecting and localizing prostate cancer recurrence. No technique for localizing and detecting prostate cancer recurrence after biochemical relapse available today is sensitive enough to localize recurrence at a stage at which salvage radiotherapy is still curative. Twenty patients (age 56 to 77 years) who had undergone radical prostatectomy and had an increasing prostate-specific antigen level measured on two consecutive occasions were included. In addition to the investigations usually performed when prostate cancer recurrence is suspected, they underwent positron emission tomography with C11-acetate as the marker. Pathologic uptake of acetate was seen in 15 (75%) of the 20 patients. In 8 of these patients, a solitary lesion was found (seven in the prostatic fossa and one at the regional lymph nodes). Multiple lesions were found in the remaining 7. False-positive uptake was seen in 3 men (15%). Additional investigations in these men revealed pathologic findings other than prostate cancer. Positron emission tomography with C11-acetate as marker is a promising method for early detection and localization of prostate cancer recurrence. False-positive uptake does occur.

  19. Spindle cell sarcoma of pulmonary artery mimicking thromboembolism with lung metastasis detected in fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography.

    PubMed

    Kamaleshwaran, Koramadai Karuppusamy; Pattabiraman, Vr; Mehta, Sangita; Mohanan, Vyshakh; Shinto, Ajit Sugunan

    2014-10-01

    Pulmonary artery sarcoma (PAS), although rare, must be considered in the differential diagnosis of pulmonary thromboembolism (PTE). This tumor is highly malignant and the prognosis is very poor. As much as the standardized uptake values (SUVs) at fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) have helped in differentiating between benign and malignant tumors, visualization of a low-attenuation filling defect within a pulmonary artery on contrast-enhanced chest computed tomography (CT) can be suggestive of a malignancy, such as PAS, if the lesion shows high FDG uptake at PET. We present a case of PAS that showed high FDG uptake on integrated FDG PET/CT and with lung metastasis. Patient underwent endoscopic bronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA), which confirmed spindle cell sarcoma.

  20. Spindle cell sarcoma of pulmonary artery mimicking thromboembolism with lung metastasis detected in fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

    PubMed Central

    Kamaleshwaran, Koramadai Karuppusamy; Pattabiraman, VR; Mehta, Sangita; Mohanan, Vyshakh; Shinto, Ajit Sugunan

    2014-01-01

    Pulmonary artery sarcoma (PAS), although rare, must be considered in the differential diagnosis of pulmonary thromboembolism (PTE). This tumor is highly malignant and the prognosis is very poor. As much as the standardized uptake values (SUVs) at fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) have helped in differentiating between benign and malignant tumors, visualization of a low-attenuation filling defect within a pulmonary artery on contrast-enhanced chest computed tomography (CT) can be suggestive of a malignancy, such as PAS, if the lesion shows high FDG uptake at PET. We present a case of PAS that showed high FDG uptake on integrated FDG PET/CT and with lung metastasis. Patient underwent endoscopic bronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA), which confirmed spindle cell sarcoma. PMID:25400365

  1. Study of material properties important for an optical property modulation-based radiation detection method for positron emission tomography.

    PubMed

    Tao, Li; Daghighian, Henry M; Levin, Craig S

    2017-01-01

    We compare the performance of two detector materials, cadmium telluride (CdTe) and bismuth silicon oxide (BSO), for optical property modulation-based radiation detection method for positron emission tomography (PET), which is a potential new direction to dramatically improve the annihilation photon pair coincidence time resolution. We have shown that the induced current flow in the detector crystal resulting from ionizing radiation determines the strength of optical modulation signal. A larger resistivity is favorable for reducing the dark current (noise) in the detector crystal, and thus the higher resistivity BSO crystal has a lower (50% lower on average) noise level than CdTe. The CdTe and BSO crystals can achieve the same sensitivity under laser diode illumination at the same crystal bias voltage condition while the BSO crystal is not as sensitive to 511-keV photons as the CdTe crystal under the same crystal bias voltage. The amplitude of the modulation signal induced by 511-keV photons in BSO crystal is around 30% of that induced in CdTe crystal under the same bias condition. In addition, we have found that the optical modulation strength increases linearly with crystal bias voltage before saturation. The modulation signal with CdTe tends to saturate at bias voltages higher than 1500 V due to its lower resistivity (thus larger dark current) while the modulation signal strength with BSO still increases after 3500 V. Further increasing the bias voltage for BSO could potentially further enhance the modulation strength and thus, the sensitivity.

  2. Impact of computed tomography and {sup 18}F-deoxyglucose coincidence detection emission tomography image fusion for optimization of conformal radiotherapy in non-small-cell lung cancer

    SciTech Connect

    Deniaud-Alexandre, Elisabeth; Touboul, Emmanuel . E-mail: emmanuel.touboul@tnn.aphp.fr; Lerouge, Delphine; Grahek, Dany; Foulquier, Jean-Noel; Petegnief, Yolande; Gres, Benoit; El Balaa, Hanna; Keraudy, Katia; Kerrou, Kaldoun; Montravers, Francoise; Milleron, Bernard; Lebeau, Bernard; Talbot, Jean-Noel

    2005-12-01

    Purpose: To report a retrospective study concerning the impact of fused {sup 18}F-fluoro-deoxy-D-glucose (FDG)-hybrid positron emission tomography (PET) and CT images on three-dimensional conformal radiotherapy planning for patients with non-small-cell lung cancer. Methods and Materials: A total of 101 patients consecutively treated for Stage I-III non-small-cell lung cancer were studied. Each patient underwent CT and FDG-hybrid PET for simulation treatment in the same treatment position. Images were coregistered using five fiducial markers. Target volume delineation was initially performed on the CT images, and the corresponding FDG-PET data were subsequently used as an overlay to the CT data to define the target volume. Results: {sup 18}F-fluoro-deoxy-D-glucose-PET identified previously undetected distant metastatic disease in 8 patients, making them ineligible for curative conformal radiotherapy (1 patient presented with some positive uptake corresponding to concomitant pulmonary tuberculosis). Another patient was ineligible for curative treatment because the fused PET-CT images demonstrated excessively extensive intrathoracic disease. The gross tumor volume (GTV) was decreased by CT-PET image fusion in 21 patients (23%) and was increased in 24 patients (26%). The GTV reduction was {>=}25% in 7 patients because CT-PET image fusion reduced the pulmonary GTV in 6 patients (3 patients with atelectasis) and the mediastinal nodal GTV in 1 patient. The GTV increase was {>=}25% in 14 patients owing to an increase in the pulmonary GTV in 11 patients (4 patients with atelectasis) and detection of occult mediastinal lymph node involvement in 3 patients. Of 81 patients receiving a total dose of {>=}60 Gy at the International Commission on Radiation Units and Measurements point, after CT-PET image fusion, the percentage of total lung volume receiving >20 Gy increased in 15 cases and decreased in 22. The percentage of total heart volume receiving >36 Gy increased in 8

  3. Impact of computed tomography and 18F-deoxyglucose coincidence detection emission tomography image fusion for optimization of conformal radiotherapy in non-small-cell lung cancer.

    PubMed

    Deniaud-Alexandre, Elisabeth; Touboul, Emmanuel; Lerouge, Delphine; Grahek, Dany; Foulquier, Jean-Noël; Petegnief, Yolande; Grès, Benoît; El Balaa, Hanna; Keraudy, Katia; Kerrou, Kaldoun; Montravers, Françoise; Milleron, Bernard; Lebeau, Bernard; Talbot, Jean-Noël

    2005-12-01

    To report a retrospective study concerning the impact of fused 18F-fluoro-deoxy-D-glucose (FDG)-hybrid positron emission tomography (PET) and CT images on three-dimensional conformal radiotherapy planning for patients with non-small-cell lung cancer. A total of 101 patients consecutively treated for Stage I-III non-small-cell lung cancer were studied. Each patient underwent CT and FDG-hybrid PET for simulation treatment in the same treatment position. Images were coregistered using five fiducial markers. Target volume delineation was initially performed on the CT images, and the corresponding FDG-PET data were subsequently used as an overlay to the CT data to define the target volume. 18F-fluoro-deoxy-D-glucose-PET identified previously undetected distant metastatic disease in 8 patients, making them ineligible for curative conformal radiotherapy (1 patient presented with some positive uptake corresponding to concomitant pulmonary tuberculosis). Another patient was ineligible for curative treatment because the fused PET-CT images demonstrated excessively extensive intrathoracic disease. The gross tumor volume (GTV) was decreased by CT-PET image fusion in 21 patients (23%) and was increased in 24 patients (26%). The GTV reduction was > or = 25% in 7 patients because CT-PET image fusion reduced the pulmonary GTV in 6 patients (3 patients with atelectasis) and the mediastinal nodal GTV in 1 patient. The GTV increase was > or = 25% in 14 patients owing to an increase in the pulmonary GTV in 11 patients (4 patients with atelectasis) and detection of occult mediastinal lymph node involvement in 3 patients. Of 81 patients receiving a total dose of > or = 60 Gy at the International Commission on Radiation Units and Measurements point, after CT-PET image fusion, the percentage of total lung volume receiving >20 Gy increased in 15 cases and decreased in 22. The percentage of total heart volume receiving >36 Gy increased in 8 patients and decreased in 14. The spinal cord

  4. Single photon emission computed tomography/computed tomography for malignant otitis externa: lesion not shown on planar image.

    PubMed

    Chen, Yu-Hung; Hsieh, Hung-Jen

    2013-01-01

    Malignant otitis externa is a severe and rare infection of the external acoustic meatus. Triphasic bone and (67)Ga scintigraphies are used to initial detect and follow-up the response of therapy. With single photon emission computed tomography/computed tomography images, the diagnostic sensitivity is higher. We presented a case with malignant otitis externa with initial negative planar scintigraphic finding. The lesion was detected by photon emission computed tomography/computed tomography images. We concluded that the photon emission computed tomography/computed tomography should be performed routinely for patients with suspected malignant otitis externa, even without evidence of lesion on planar images. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Discovery of the primary site of esophageal squamous cell carcinoma based on axillary lymph nodes metastasis detected with fluorodeoxyglucose positron-emission tomography: report of a case.

    PubMed

    Hagiwara, Nobutoshi; Matsutani, Takeshi; Nomura, Tsutomu; Miyashita, Masao; Yamashita, Naoyuki; Wachi, Eiko; Uchida, Eiji

    2014-01-01

    A 60-year-old Japanese man with no chief complaints underwent 18F-fluorodeoxyglucose positron-emission tomography (FDG-PET) during a medical check-up. FDG-PET revealed high tracer uptake in the left supraclavicular and axillary regions but no significant uptake in the esophageal region. However, upper gastrointestinal endoscopy revealed an ulcerative tumor in the middle third of the esophagus. Endoscopic biopsy revealed moderately differentiated squamous cell carcinoma. The patient underwent chemoradiotherapy. Follow-up FDG-PET and computed tomography after therapy revealed a complete response in the lymph nodes. The patient underwent subtotal esophagectomy with gastric tube reconstruction through the posterior mediastinum. However, metastasis to the axillary lymph nodes was detected 16 months after surgery, and lymph node dissection was performed. To our knowledge, this is the first reported case in which the primary site of esophageal squamous cell carcinoma was discovered on the basis of axillary lymph node metastasis detected with FDG-PET.

  6. Clinical evaluation of emission tomography using seven-pinhole collimator: improved detection of perfusion defect by the addition of the right anterior oblique projection

    SciTech Connect

    Tamaki, N.; Yonekura, Y.; Mukai, T.; Yamamoto, K.; Fujita, T.; Minato, K.; Ishii, Y.; Torizuka, K.; Kambara, H.; Kawai, C.

    1982-04-01

    The clinical efficacy of thallium emission myocardial tomography using a seven-pinhole collimator in the right anterior oblique (RAO) projection was evaluated. Myocardial tomography in left anterior oblique (LAO) and RAO projections was performed following planar thallium perfusion imaging at rest in 11 patients with myocardial infarction. The RAO tomogram was useful, especially in detecting apical perfusion defects, while the LAO tomogram was useful in detecting inferior and anteroseptal wall defects. For the four patients without an apparent myocardial perfusion defect seen on the planar image, the LAO tomogram showed a perfusion defect in three, and the RAO tomogram also showed the defect in three. One or the other of the two views demonstrated the defect for all 11 patients. The myocardial tomogram in the RAO projection, providing a sufficiently high-quality and high-contrast image, gives useful information complementary to the findings of the commonly used LAO projection in the evaluation of myocardial infarctions.

  7. Development of novel emission tomography system

    NASA Astrophysics Data System (ADS)

    Fu, Geng

    In recent years, small animals, such as mice and rats, have been widely used as subjects of study in biomedical research while molecular biology and imaging techniques open new opportunities to investigate disease model. With the help of medical imaging techniques, researchers can investigate underlying mechanisms inside the small animal, which are useful for both early diagnosis and treatment monitoring. Based on tracer principle single photon emission computed tomography (SPECT) has increased popularity in small animal imaging due to its higher spatial resolution and variety of single-photon emitting radionuclides. Since the image quality strongly depends on the detector properties, both scintillation and semiconductor detectors are under active investigation for high resolution X-ray and gamma ray photon detection. The desired detector properties include high intrinsic spatial resolution, high energy resolution, and high detection efficiency. In this thesis study, we have made extensive efforts to develop novel emission tomography system, and evaluate the use of both semiconductor and ultra-high resolution scintillation detectors for small animal imaging. This thesis work includes the following three areas. Firstly, we have developed a novel energy-resolved photon counting (ERPC) detector. With the benefits of high energy resolution, high spatial resolution, flexible detection area, and a wide dynamic range of 27--200keV, ERPC detector is well-suited for small animal SPECT applications. For prototype ERPC detector excellent imaging (˜350microm) and spectroscopic performance (4keV Co-57 122keV) has been demonstrated in preliminary study. Secondly, to further improve spatial resolution to hundred-micron level, an ultra-high resolution Intensified EMCCD (I-EMCCD) detector has been designed and evaluated. This detector consists of the newly developed electron multiplying CCD (EMCCD) sensor, columnar CsI(Tl) scintillator, and an electrostatic de-magnifier (DM) tube

  8. [Detection of inflammation in an atherosclerose plaque: the role of the positron emission tomography and C reactive protein].

    PubMed

    Alexánderson, Erick; Mendoza, Raúl G; Adame, Gloria; Talayero, José Antonio; Sierra, Carlos; Cruz, Patricio; García-Rojas, Leonardo; Rodríguez-Valero, Mónica; Flores, Armando; Zárate, Adolfo; Meave, Aloha; Arauz, Antonio

    2007-01-01

    To demonstrate that inflammatory atheromatose carotid plaques can be visualized with positron emission tomography with 18F-fluorodeoxyglucose (18FDG PET) in symptomatic patients, in order to correlate them with systemic inflammatory markers, such as CRP. Fifteen patients with cerebral ischemia due to atherosclerotic carotid disease were studied. 18FDG uptake with PET was considered and blood samples were taken for determining high sensibility C reactive protein (HsCRP). The mean age of the patients was 66 years; 11 of them were males (73%) and 4 were females (27%). 18FDG PET was positive in 12 patients (80%), while 100% of the studied population had low risk HsCRP with normal white cell count. 18FDG PET proves active inflammation in carotid atheromatose plaques. There was no significant correlation between the presence of ahteromatose carotid plaques, HsCRP serum levels, and 18FDG PET study.

  9. Single photon emission computed tomography

    SciTech Connect

    Piez, C.W. Jr.; Holman, B.L.

    1985-07-01

    Single photon emission computed tomography (SPECT) is becoming an increasingly important part of routine clinical nuclear medicine. By providing tomographic reconstructions in multiple planes through the patient, SPECT expands the clinical applications in nuclear medicine as well as providing better contrast, edge definition and separation of target from background activities. Imaging techniques have been developed for the evaluation of regional cerebral blood flow using radiolabeled amines. Thus, cerebral functional imaging can be used in the diagnosis of acute cerebral infarction, cerebral vascular disease, dementia and epilepsy. SPECT plays a complementary role in the evaluation of coronary artery disease, particularly when it is coupled with thallium-201 and exercise testing. SPECT extends our diagnostic capabilities in additional areas, such as liver and bone scintigraphy as well as tumor imaging with gallium-67.

  10. Exercise four hour redistribution thallium-201 single photon emission computed tomography and exercise induced ST segment elevation in detecting the viable myocardium in patients with acute myocardial infarction

    PubMed Central

    Yamagishi, H; Akioka, K; Takagi, M; Tanaka, A; Takeuchi, K; Yoshikawa, J; Ochi, H

    1999-01-01

    Objective—To investigate the specificity and sensitivity of the combination of redistribution in exercise thallium-201 single photon emission computed tomography (SPECT) and exercise induced ST elevation for detecting the viable myocardium in patients with acute myocardial infarction.
Design—37 patients were studied within seven weeks of onset of Q wave myocardial infarction (anterior in 22, inferior in 15). All patients underwent exercise four hour redistribution thallium-201 SPECT and positron emission tomography using fluorine-18-fluorodeoxyglucose (FDG) and nitrogen-13 ammonia under fasting conditions.
Results—Sixteen patients showed exercise induced ST elevation ⩾ 1.5 mm, and 15 of these had increased FDG uptake in the infarct region. Eleven of 16 patients (10 of 11 patients with anterior infarctions) with irreversible thallium-201 defects and increased FDG uptake showed exercise induced ST elevation. The sensitivity, specificity, and predictive accuracy of redistribution, exercise induced ST segment elevation, or both for detecting increased FDG uptake were 82%, 75%, and 67% (94%, 75%, and 91% for anterior infarctions), respectively. 
Conclusions—In patients with acute Q wave myocardial infarction, the combination of redistribution in exercise thallium-201 SPECT and exercise induced ST elevation can detect the viable myocardium in the infarct region with high sensitivity and specificity, especially in patients with anterior infarctions.

 Keywords: acute myocardial infarction;  viability;  exercise induced ST elevation;  exercise thallium-201 SPECT PMID:10220539

  11. Detection of lymph node metastases in pediatric and adolescent/young adult sarcoma: Sentinel lymph node biopsy versus fludeoxyglucose positron emission tomography imaging-A prospective trial.

    PubMed

    Wagner, Lars M; Kremer, Nathalie; Gelfand, Michael J; Sharp, Susan E; Turpin, Brian K; Nagarajan, Rajaram; Tiao, Gregory M; Pressey, Joseph G; Yin, Julie; Dasgupta, Roshni

    2017-01-01

    Lymph node metastases are an important cause of treatment failure for pediatric and adolescent/young adult (AYA) sarcoma patients. Nodal sampling is recommended for certain sarcoma subtypes that have a predilection for lymphatic spread. Sentinel lymph node biopsy (SLNB) may improve the diagnostic yield of nodal sampling, particularly when single-photon emission computed tomography/computed tomography (SPECT-CT) is used to facilitate anatomic localization. Functional imaging with positron emission tomography/computed tomography (PET-CT) is increasingly used for sarcoma staging and is a less invasive alternative to SLNB. To assess the utility of these 2 staging methods, this study prospectively compared SLNB plus SPECT-CT with PET-CT for the identification of nodal metastases in pediatric and AYA patients. Twenty-eight pediatric and AYA sarcoma patients underwent SLNB with SPECT-CT. The histological findings of the excised lymph nodes were then correlated with preoperative PET-CT imaging. A median of 2.4 sentinel nodes were sampled per patient. No wound infections or chronic lymphedema occurred. SLNB identified tumors in 7 of the 28 patients (25%), including 3 patients who had normal PET-CT imaging of the nodal basin. In contrast, PET-CT demonstrated hypermetabolic regional nodes in 14 patients, and this resulted in a positive predictive value of only 29%. The sensitivity and specificity of PET-CT for detecting histologically confirmed nodal metastases were only 57% and 52%, respectively. SLNB can safely guide the rational selection of nodes for biopsy in pediatric and AYA sarcoma patients and can identify therapy-changing nodal disease not appreciated with PET-CT. Cancer 2017;155-160. © 2016 American Cancer Society. © 2016 American Cancer Society.

  12. Fan Beam Emission Tomography for Laminar Fires

    NASA Technical Reports Server (NTRS)

    Sivathanu, Yudaya; Lim, Jongmook; Feikema, Douglas

    2003-01-01

    Obtaining information on the instantaneous structure of turbulent and transient flames is important in a wide variety of applications such as fire safety, pollution reduction, flame spread studies, and model validation. Durao et al. has reviewed the different methods of obtaining structure information in reacting flows. These include Tunable Laser Absorption Spectroscopy, Fourier Transform Infrared Spectroscopy, and Emission Spectroscopy to mention a few. Most flames emit significant radiation signatures that are used in various applications such as fire detection, light-off detection, flame diagnostics, etc. Radiation signatures can be utilized to maximum advantage for determining structural information in turbulent flows. Emission spectroscopy is most advantageous in the infrared regions of the spectra, principally because these emission lines arise from transitions in the fundamental bands of stable species such as CO2 and H2O. Based on the above, the objective of this work was to develop a fan beam emission tomography system to obtain the local scalar properties such as temperature and mole fractions of major gas species from path integrated multi-wavelength infrared radiation measurements.

  13. Compact conscious animal positron emission tomography scanner

    DOEpatents

    Schyler, David J.; O'Connor, Paul; Woody, Craig; Junnarkar, Sachin Shrirang; Radeka, Veljko; Vaska, Paul; Pratte, Jean-Francois; Volkow, Nora

    2006-10-24

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal for an event, generating an address signal representing a detecting channel, generating a detector channel signal including the time and address signals, and generating a composite signal including the channel signal and similarly generated signals. The composite signal includes events from detectors in a block and is serially output. An apparatus that serially transfers annihilation information from a block includes time signal generators for detectors in a block and an address and channel signal generator. The PET scanner includes a ring tomograph that mounts onto a portion of an animal, which includes opposing block pairs. Each of the blocks in a block pair includes a scintillator layer, detection array, front-end array, and a serial encoder. The serial encoder includes time signal generators and an address signal and channel signal generator.

  14. Imaging tumour hypoxia with positron emission tomography

    PubMed Central

    Fleming, I N; Manavaki, R; Blower, P J; West, C; Williams, K J; Harris, A L; Domarkas, J; Lord, S; Baldry, C; Gilbert, F J

    2015-01-01

    Hypoxia, a hallmark of most solid tumours, is a negative prognostic factor due to its association with an aggressive tumour phenotype and therapeutic resistance. Given its prominent role in oncology, accurate detection of hypoxia is important, as it impacts on prognosis and could influence treatment planning. A variety of approaches have been explored over the years for detecting and monitoring changes in hypoxia in tumours, including biological markers and noninvasive imaging techniques. Positron emission tomography (PET) is the preferred method for imaging tumour hypoxia due to its high specificity and sensitivity to probe physiological processes in vivo, as well as the ability to provide information about intracellular oxygenation levels. This review provides an overview of imaging hypoxia with PET, with an emphasis on the advantages and limitations of the currently available hypoxia radiotracers. PMID:25514380

  15. [Positron emission tomography/computed tomography in rheumatology].

    PubMed

    Derlin, T

    2017-06-29

    Combined positron emission tomography/computed tomography (PET/CT) is a whole-body imaging procedure, which enables sensitive detection of inflammatory changes. It may be used to simultaneously obtain both precise anatomical and molecular information in order to comprehensively characterize diseases. The glucose analogue (18)F-fluorodeoxyglucose (FDG) represents a universally applicable radiotracer for imaging of inflammatory processes. Its accumulation in tissues can be semiquantitatively characterized by use of standardized uptake values (SUV). In principle, a broad spectrum of infectious and non-infectious inflammatory and malignant diseases can be imaged. (18)F-FDG PET/CT has become a valuable modality and is increasingly being used for evaluation of large vessel vasculitis and for evaluation of elevated systemic inflammatory markers without known cause. Beside the radiotracer (18)F-FDG, other radiopharmaceuticals enable a non-invasive analysis of additional parameters of inflammatory disorders, such as other metabolic pathways or the expression of surface receptors.

  16. Estimation of linear functionals in emission tomography

    SciTech Connect

    Kuruc, A.

    1995-08-01

    In emission tomography, the spatial distribution of a radioactive tracer is estimated from a finite sample of externally-detected photons. We present an algorithm-independent theory of statistical accuracy attainable in emission tomography that makes minimal assumptions about the underlying image. Let f denote the tracer density as a function of position (i.e., f is the image being estimated). We consider the problem of estimating the linear functional {Phi}(f) {triple_bond} {integral}{phi}(x)f(x) dx, where {phi} is a smooth function, from n independent observations identically distributed according to the Radon transform of f. Assuming only that f is bounded above and below away from 0, we construct statistically efficient estimators for {Phi}(f). By definition, the variance of the efficient estimator is a best-possible lower bound (depending on and f) on the variance of unbiased estimators of {Phi}(f). Our results show that, in general, the efficient estimator will have a smaller variance than the standard estimator based on the filtered-backprojection reconstruction algorithm. The improvement in performance is obtained by exploiting the range properties of the Radon transform.

  17. Comparison of magnetic resonance spectroscopy and positron emission tomography in detection of tumor recurrence in posttreatment of glioma: A diagnostic meta-analysis.

    PubMed

    Wang, Xiaoyue; Hu, Xudong; Xie, Peng; Li, Wanhu; Li, Xiaoling; Ma, Li

    2015-06-01

    It is important to distinguish between tumor recurrence and treatment effects in posttreatment patients with high-grade gliomas. Several imaging modalities have been reported in differentiating between tumor recurrence and treatment effects. However, there were no consistent conclusions between different studies. We performed a meta-analysis of 23 studies that compared the diagnostic values of fluorine-18-fluorodeoxyglucose ((18)F-FDG) and (11)C-methionine ((11)C-MET) PET (positron emission tomography) or PET/CT (computed tomography) and magnetic resonance spectroscopy (MRS) in predicting tumor recurrence of gliomas. The pooled estimated sensitivity, specificity, positive likelihood ratios, negative likelihood ratios and summary receiver operating characteristic curves of (18)F-FDG and (11)C-MET PET or PET/CT and MRS in detecting tumor recurrence were calculated. In conclusion, MRS is highly sensitive in the detection of tumor recurrence in glioma.(18)F-FDG PET or PET/CT is highly specific in recurrence diagnosis. (11)C-MET does not have noticeable advantage over (18)F-FDG. The current evidence shows no statistical difference between MRS and PET on the accuracy.

  18. Tumor Quantification in Clinical Positron Emission Tomography

    PubMed Central

    Bai, Bing; Bading, James; Conti, Peter S

    2013-01-01

    Positron emission tomography (PET) is used extensively in clinical oncology for tumor detection, staging and therapy response assessment. Quantitative measurements of tumor uptake, usually in the form of standardized uptake values (SUVs), have enhanced or replaced qualitative interpretation. In this paper we review the current status of tumor quantification methods and their applications to clinical oncology. Factors that impede quantitative assessment and limit its accuracy and reproducibility are summarized, with special emphasis on SUV analysis. We describe current efforts to improve the accuracy of tumor uptake measurements, characterize overall metabolic tumor burden and heterogeneity of tumor uptake, and account for the effects of image noise. We also summarize recent developments in PET instrumentation and image reconstruction and their impact on tumor quantification. Finally, we offer our assessment of the current development needs in PET tumor quantification, including practical techniques for fully quantitative, pharmacokinetic measurements. PMID:24312151

  19. Detection rate of (99m) Tc-MIBI single photon emission computed tomography (SPECT)/CT in preoperative planning for patients with primary hyperparathyroidism: A meta-analysis.

    PubMed

    Treglia, Giorgio; Sadeghi, Ramin; Schalin-Jäntti, Camilla; Caldarella, Carmelo; Ceriani, Luca; Giovanella, Luca; Eisele, David W

    2016-04-01

    Parathyroid scintigraphy using (99m) Tc-MIBI single photon emission computed tomography (SPECT)/CT has been proposed as one of the most accurate localization techniques in patients with primary hyperparathyroidism (PHPT). The purpose of this review was to meta-analyze published data on the detection rate of (99m) Tc-MIBI SPECT/CT in the preoperative planning of patients with PHPT. A comprehensive literature search of studies published through June 2014 was performed. The pooled detection rate of this scintigraphic method including 95% confidence intervals (95% CIs) was calculated on a per patient-based and on a per lesion-based analysis by using a random effects model. Twenty-three articles including 1236 patients with PHPT were selected. The pooled detection rate of (99m) Tc-MIBI SPECT/CT in the preoperative planning of patients with PHPT was 88% (95% CI = 84% to 92%) and 88% (95% CI = 82% to 92%) on a per patient-based and per lesion-based analysis, respectively. The (99m) Tc-MIBI SPECT/CT has high detection rate for hyperfunctioning parathyroid glands in patients with PHPT. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2159-E2172, 2016. © 2015 Wiley Periodicals, Inc.

  20. Recent Developments in Positron Emission Tomography (PET) Instrumentation

    DOE R&D Accomplishments Database

    Derenzo, S. E.; Budinger, T. F.

    1986-04-01

    This paper presents recent detector developments and perspectives for positron emission tomography (PET) instrumentation used for medical research, as well as the physical processes in positron annihilation, photon scattering and detection, tomograph design considerations, and the potentials for new advances in detectors.

  1. Recent developments in positron emission tomography (PET) instrumentation

    SciTech Connect

    Derenzo, S.E.; Budinger, T.F.

    1986-04-01

    This paper presents recent detector developments and perspectives for positron emission tomography (PET) instrumentation used for medical research, as well as the physical processes in positron annihilation, photon scattering and detection, tomograph design considerations, and the potentials for new advances in detectors. 117 refs., 4 figs., 4 tabs.

  2. Single photon emission computed tomography/computed tomography of the skull in malignant otitis externa.

    PubMed

    Chakraborty, Dhritiman; Bhattacharya, Anish; Kamaleshwaran, Koramadai Karuppusamy; Agrawal, Kanhaiyalal; Gupta, Ashok Kumar; Mittal, Bhagwant Rai

    2012-01-01

    Malignant otitis externa is a severe, rare infective condition of the external auditory canal and skull base. The diagnosis is generally made from a range of clinical, laboratory, and imaging findings. Technetium 99m methylene diphosphonate bone scintigraphy is known to detect osteomyelitis earlier than computed tomography. The authors present a patient with bilateral malignant otitis externa where the extent of skull base involvement was determined on 3-phase bone scintigraphy with single photon emission computed tomography/computed tomography. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Added value of using a cocktail of F-18 sodium fluoride and F-18 fluorodeoxyglucose in positron emission tomography/computed tomography for detecting bony metastasis: a case report.

    PubMed

    Chan, Hung-Pin; Hu, Chin; Yu, Chang-Ching; Huang, Tsung-Chi; Peng, Nan-Jing

    2015-04-01

    Current nuclear imaging of the skeletal system is achieved using technetium-99m (Tc-99m) methylene diphosphonate (MDP), F-18 sodium fluoride (NaF), or F-18 fluorodeoxyglucose (FDG). However, comparisons of these are rare in the literature. We present a case of a 51-year-old female with suspicious lung cancer due to main symptoms of dyspnea, nonproductive cough, and pleural pain. Tc-99m MDP whole-body bone scan (WBBS) showed multiple bony metastases. Five days later, positron emission tomography/computed tomography (PET/CT) images using both F-18 NaF and a cocktail of F-18 NaF and F-18 FDG were obtained on the same day 2 hours apart. The former showed more foci and precisely showed bony lesions compared to those obtained using Tc-99m MDP WBBS. However, the latter demonstrated more extensive radiotracer uptake, especially in osteolytic lesions, and additional soft tissue lesions in the left axillary and surpraclavicular nodes as well as the left pleura. Surgical biopsy was performed in left axillary nodes, and the metastatic carcinoma was found to be of breast origin. This case demonstrated that a cocktail of F-18 NaF and F-18 FDG could be useful in PET/CT for not only detecting more skeletal lesions but also guiding biopsies accurately to the affected tissue.

  4. Neural networks combined with region growing techniques for tumor detection in [18F]-fluorothymidine dynamic positron emission tomography breast cancer studies

    NASA Astrophysics Data System (ADS)

    Cseh, Zoltan; Kenny, Laura; Swingland, James; Bose, Subrata; Turheimer, Federico E.

    2013-03-01

    Early detection and precise localization of malignant tumors has been a primary challenge in medical imaging in recent years. Functional modalities play a continuously increasing role in these efforts. Image segmentation algorithms which enable automatic, accurate tumor visualization and quantification on noisy positron emission tomography (PET) images would significantly improve the quality of treatment planning processes and in turn, the success of treatments. In this work a novel multistep method has been applied in order to identify tumor regions in 4D dynamic [18F] fluorothymidine (FLT) PET studies of patients with locally advanced breast cancer. In order to eliminate the effect of inherently detectable high inhomogeneity inside tumors, specific voxel-kinetic classes were initially introduced by finding characteristic FLT-uptake curves with K-means algorithm on a set of voxels collected from each tumor. Image voxel sets were then split based on voxel time-activity curve (TAC) similarities, and models were generated separately on each voxel set. At first, artificial neural networks, in comparison with linear classification algorithms were applied to distinguish tumor and healthy regions relying on the characteristics of TACs of the individual voxels. The outputs of the best model with very high specificity were then used as input seeds for region shrinking and growing techniques, the application of which considerably enhanced the sensitivity and specificity (78.65% +/- 0.65% and 98.98% +/- 0.03%, respectively) of the final image segmentation model.

  5. Comparison of Positron Emission Tomography Scanning and Sentinel Node Biopsy in the Detection of Inguinal Node Metastases in Patients With Anal Cancer

    SciTech Connect

    Mistrangelo, Massimiliano; Pelosi, Ettore; Bello, Marilena; Castellano, Isabella; Cassoni, Paola; Ricardi, Umberto; Munoz, Fernando; Racca, Patrizia; Contu, Viviana; Beltramo, Giancarlo; Morino, Mario; Mussa, Antonio

    2010-05-01

    Background: Inguinal lymph node metastases in patients with anal cancer are an independent prognostic factor for local failure and overall mortality. Inguinal lymph node status can be adequately assessed with sentinel node biopsy, and the radiotherapy strategy can subsequently be changed. We compared this technique vs. dedicated 18F-fluorodeoxyglucose positron emission tomography (PET) to determine which was the better tool for staging inguinal lymph nodes. Methods and Materials: In our department, 27 patients (9 men and 18 women) underwent both inguinal sentinel node biopsy and PET-CT. PET-CT was performed before treatment and then at 1 and 3 months after treatment. Results: PET-CT scans detected no inguinal metastases in 20 of 27 patients and metastases in the remaining 7. Histologic analysis of the sentinel lymph node detected metastases in only three patients (four PET-CT false positives). HIV status was not found to influence the results. None of the patients negative at sentinel node biopsy developed metastases during the follow-up period. PET-CT had a sensitivity of 100%, with a negative predictive value of 100%. Owing to the high number of false positives, PET-CT specificity was 83%, and positive predictive value was 43%. Conclusions: In this series of patients with anal cancer, inguinal sentinel node biopsy was superior to PET-CT for staging inguinal lymph nodes.

  6. Detection of vulnerable atherosclerosis plaques with a dual-modal single-photon-emission computed tomography/magnetic resonance imaging probe targeting apoptotic macrophages.

    PubMed

    Cheng, Dengfeng; Li, Xiao; Zhang, Chunfu; Tan, Hui; Wang, Cong; Pang, Lifang; Shi, Hongcheng

    2015-02-04

    Atherosclerosis (AS), especially the vulnerable AS plaque rupture-induced acute obstructive vascular disease, is a leading cause of death. Accordingly, there is a need for an effective method to draw accurate predictions about AS progression and plaque vulnerability. Herein we report on an approach to constructing a hybrid nanoparticle system using a single-photon-emission computed tomography (SPECT)/magnetic resonance imaging (MRI) multimodal probe, aiming for a comprehensive evaluation of AS progression by achieving high sensitivity along with high resolution. Ultrasmall superparamagnetic iron oxide (USPIO) was covered by aminated poly(ethylene glycol) (PEG) and carboxylated PEG simultaneously and then functionalized with diethylenetriaminepentacetate acid for (99m)Tc coordination and subsequently Annexin V for targeting apoptotic macrophages abundant in vulnerable plaques. The in vivo accumulations of imaging probe reflected by SPECT and MRI were consistent and accurate in highlighting lesions. Intense radioactive signals detected by SPECT facilitated focus recognization and quantification, while USPIO-based T2-weighted MRI improved the focal localization and volumetry of AS plaques. For subsequent ex vivo planar images, targeting effects were further confirmed by immunohistochemistry, including CD-68 and TUNEL staining; meanwhile, the degree of concentration was proven to be statistically correlated with the Oil Red O staining results. In conclusion, these results indicated that the Annexin V-modified hybrid nanoparticle system specifically targeted the vulnerable AS plaques containing apoptotic macrophages and could be of great value in the invasively accurate detection of vulnerable plaques.

  7. Positron Emission Tomography: A Basic Analysis

    NASA Astrophysics Data System (ADS)

    Kerbacher, M. E.; Deaton, J. W.; Phinney, L. C.; Mitchell, L. J.; Duggan, J. L.

    2007-10-01

    Positron Emission Tomography is useful in detecting biological abnormalities. The technique involves attaching radiotracers to a material used inside the body, in many cases glucose. Glucose is absorbed most readily in areas of unusual cell growth or uptake of nutrients so through natural processes the treated glucose highlights regions of tumors and other degenerative disorders such as Alzheimer's disease. The higher the concentration of isotopes, the more dynamic the area. Isotopes commonly used as tracers are 11C, 18F, 13N, and 15O due to their easy production and short half-lives. Once the tracers have saturated an area of tissue they are detected using coincidence detectors collinear with individual isotopes. As the isotope decays it emits a positron which, upon annihilating an electron, produces two oppositely directioned gamma rays. The PET machine consists of several pairs of detectors, each 180 degrees from their partner detector. When the oppositely positioned detectors are collinear with the area of the isotope, a computer registers the location of the isotope and can compile an image of the activity of the highlighted area based on the position and strength of the isotopes.

  8. Advanced Instrumentation for Positron Emission Tomography [PET

    DOE R&D Accomplishments Database

    Derenzo, S. E.; Budinger, T. F.

    1985-04-01

    This paper summarizes the physical processes and medical science goals that underlay modern instrumentation design for Positron Emission Tomography. The paper discusses design factors such as detector material, crystalphototube coupling, shielding geometry, sampling motion, electronics design, time-of-flight, and the interrelationships with quantitative accuracy, spatial resolution, temporal resolution, maximum data rates, and cost.

  9. Advanced instrumentation for Positron Emission Tomography

    SciTech Connect

    Derenzo, S.E.; Budinger, T.F.

    1985-04-01

    This paper summarizes the physical processes and medical science goals that underly modern instrumentation design for Positron Emission Tomography. The paper discusses design factors such as detector material, crystalphototube coupling, shielding geometry, sampling motion, electronics design, time-of-flight, and the interrelationships with quantitative accuracy, spatial resolution, temporal resolution, maximum data rates, and cost. 71 refs., 3 figs., 3 tabs.

  10. A Prospective Analysis of Positron Emission Tomography and Conventional Imaging for Detection of Stage IV Metastatic Melanoma in Patients Undergoing Metastasectomy

    PubMed Central

    Finkelstein, Steven E.; Carrasquillo, Jorge A.; Hoffman, John M.; Galen, Barbara; Choyke, Peter; White, Donald E.; Rosenberg, Steven A.; Sherry, Richard M.

    2008-01-01

    Background Positron emission tomography with 2-deoxy-2-[18F]fluoro-d-glucose (FDG-PET) is available for evaluation of patients with melanoma. This study evaluates the potential of FDG-PET to improve on conventional imaging (CI) in patients with stage IV melanoma undergoing metastasectomy. Methods This was a prospective study comparing radiological evaluation of patients who underwent metastasectomy for palliation or cure. Patients underwent preoperative evaluation by physical examination, CI by computed tomography and/or magnetic resonance imaging, and FDG-PET. Independent observers performed three separate analyses of CI alone, FDG-PET alone, or FDG-PET read with knowledge of CI (FDG-PET + CI). Abnormalities were reported as benign or malignant and assessed by pathologic analysis or by clinical outcome determined by disease progression detected on serial evaluations. Results Ninety-four lesions were noted in 18 patients who underwent preoperative assessment, metastasectomy, and long-term follow up (median, 24 months). Lesion-by-lesion analysis for CI demonstrated a sensitivity of 76%, a specificity of 87%, a positive predictive value (PPV) of 86%, and a negative predictive value (NPV) of 76%. FDG-PET demonstrated a sensitivity of 79%, a specificity of 87%, a PPV of 86%, and an NPV of 80%. For FDG-PET + CI, the sensitivity was 88%, specificity was 91%, and PPV and NPV were 91% and 88%, respectively. Conclusions Combined use of FDG-PET and CI may be an accurate strategy to identify sites of disease in patients with stage IV melanoma being considered for metastasectomy. Interpreted independently, FDG-PET and CI seemed to be equivalent modalities. FDG-PET + CI had both the highest sensitivity on lesion-by-lesion analysis and the best accuracy on patient-by-patient analysis. PMID:15249335

  11. Positron emission tomography - a new approach to brain chemistry

    SciTech Connect

    Jacobson, H.G.

    1988-11-11

    Positron emission tomography permits examination of the chemistry of the brain in living beings. Until recently, positron emission tomography had been considered a research tool, but it is rapidly moving into clinical practice. This report describes the uses and applications of positron emission tomography in examinations of patients with strokes, epilepsy, malignancies, dementias, and schizophrenia and in basic studies of synaptic neurotransmission.

  12. Imaging in breast cancer: Single-photon computed tomography and positron-emission tomography

    PubMed Central

    Bénard, François; Turcotte, Éric

    2005-01-01

    Although mammography remains a key imaging method for the early detection and screening of breast cancer, the overall accuracy of this test remains low. Several radiopharmaceuticals have been proposed as adjunct imaging methods to characterize breast masses by single-photon-emission computed tomography (SPECT) and positron-emission tomography (PET). Useful in characterizing indeterminate palpable masses and in the detection of axillary metastases, these techniques are insufficiently sensitive to detect subcentimetric tumor deposits. Their role in staging nodal involvement of the axillary areas therefore currently remains limited. Several enzymes and receptors have been targeted for imaging breast cancers with PET. [18F]Fluorodeoxyglucose is particularly useful in the detection and staging of recurrent breast cancer and in assessing the response to chemotherapy. Several other ligands targeting proliferative activity, protein synthesis, and hormone and cell-membrane receptors may complement this approach by providing unique information about biological characteristics of breast cancer across primary and metastatic tumor sites. PMID:15987467

  13. Evaluation of cancer detection with whole-body positron emission tomography (PET) and 2-[F-18]fluoro-2-deoxy-D-glucose

    NASA Astrophysics Data System (ADS)

    Hoh, Carl K.; Hawkins, Randall A.; Glaspy, John A.; Dahlbom, Magnus; Tse, Nielson Y.; Hoffman, Edward T.; Schiepers, Christiaan; Choi, Yong; Rege, Sheila; Nitzsche, Egbert U.; Maddahi, Jamshid; Phelps, Michael E.

    1993-08-01

    Until recently, positron emission tomography (PET) has been acquired and displayed in a standard transaxial image format. The development of whole body PET has allowed biochemical and physiologic imaging of the entire body, expanding the limited axial field of view of the conventional PET scanner. In this study, the application of whole body PET studies with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG) for tumor imaging was evaluated. Whole body PET studies were positive (presence of focal FDG uptake relative to surrounding tissue activity) in 61 of 70 patients (87%) with biopsy confirmed malignant tumors. PET images failed to reveal focal hypermetabolism in 9 of the 70 patients. Of the 17 patients with benign biopsies lesions, 13 patients had whole body PET studies without focal areas of FDG uptake. Because of the high glycolytic rate of malignant tissue, the whole body PET FDG technique has promise in the detection of a wide variety of both primary and metastatic malignancies. The presence of FDG uptake in benign inflammatory conditions may limit the specificity of the technique. The true positive rates for the characterization of known lesions was 87% in this series, and the PET FDG method is promising both in determining both the nature of a localized lesion, and in defining the systemic extent of malignant disease.

  14. Positron emission tomography in generalized seizures

    SciTech Connect

    Theodore, W.H.; Brooks, R.; Margolin, R.; Patronas, N.; Sato, S.; Porter, R.J.; Mansi, L.; Bairamian, D.; DiChiro, G.

    1985-05-01

    The authors used /sup 18/F-fluorodeoxyglucose (FDG) positron emission tomography (PET) to study nine patients with clinical absence or generalized seizures. One patient had only absence seizures, two had only generalized tonic-clonic seizures, and six had both seizure types. Interictal scans in eight failed to reveal focal or lateralized hypometabolism. No apparent abnormalities were noted. Two patients had PET scans after isotope injection during hyperventilation-induced generalized spike-wave discharges. Diffusely increased metabolic rates were found in one compared with an interictal scan, and in another compared with control values. Another patient had FDG injected during absence status: EEG showed generalized spike-wave discharges (during which she was unresponsive) intermixed with slow activity accompanied by confusion. Metabolic rates were decreased, compared with the interictal scan, throughout both cortical and subcortical structures. Interictal PET did not detect specific anatomic regions responsible for absence seizure onset in any patient, but the results of the ictal scans did suggest that pathophysiologic differences exist between absence status and single absence attacks.

  15. Amorphous silicon detectors in positron emission tomography

    SciTech Connect

    Conti, M. Lawrence Berkeley Lab., CA ); Perez-Mendez, V. )

    1989-12-01

    The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters {epsilon}{sup 2}{tau}'s are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs.

  16. Role of 18-fluoro-2-deoxyglucose positron emission tomography in detecting acute inflammatory lesions of non-bacterial osteitis in patients with a fever of unknown origin: A comparative study of 18-fluoro-2-deoxyglucose positron emission tomography, bone scan, and magnetic resonance imaging.

    PubMed

    Shimizu, Masaki; Saikawa, Yutaka; Yachie, Akihiro

    2016-06-20

    We report three patients with non-bacterial osteitis (NBO) who had fever of unknown origin (FUO) as an initial symptom. 18-Fluoro-2-deoxyglucose positron emission tomography ((18)F-FDG-PET) can be used to detect acute inflammatory lesions. There seems to be variation among the results of (18)F-FDG-PET, a bone scan, and magnetic resonance imaging (MRI). Therefore, it would be useful to perform a bone scan to detect all lesions, combined with MRI to confirm the diagnosis of NBO, followed by (18)F-FDG-PET.

  17. Positron emission tomography/computed tomography in melanoma.

    PubMed

    Bourgeois, Austin C; Chang, Ted T; Fish, Lindsay M; Bradley, Yong C

    2013-09-01

    Fludeoxyglucose F 18 positron emission tomography/computed tomography (PET/CT) has been invaluable in the assessment of melanoma throughout the course of the disease. As with any modality, the studies are incomplete and more information will be gleaned as our experience progresses. Additionally, it is hoped that a newer PET agent in the pipeline will give us even greater success in the identification and subsequent treatment of melanoma. This article aims to examine the utilization of PET/CT in the staging, prognostication, and follow-up of melanoma while providing the physicians who order and interpret these studies practical guidelines and interpretive pitfalls. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Improving Detection of Axillary Lymph Nodes by Computer-Aided Kinetic Feature Identification in Positron Emission Tomography

    DTIC Science & Technology

    2004-08-01

    Detection of Early Metastasized Molecular Feature (IDEMMF) system; and test and evaluate the prototype with phantom , animal study and clinical patient...reported below. 5 2.1.1 TAC feature extraction Using dynamic phantom data with known ground truth, we tested, to a certain degree, how the time activity...averaged time activity curve. We have performed an experimental study with a realistic liver phantom . In the liver phantom three artificial spherical

  19. Single photon emission computed tomography (SPECT) and SPECT/low-dose computerized tomography did not increase sensitivity or specificity compared to planar bone scintigraphy for detection of bone metastases in advanced breast cancer.

    PubMed

    Haraldsen, Ate; Bluhme, Henrik; Røhl, Lisbeth; Pedersen, Erik Morre; Jensen, Anders Bonde; Hansen, Eva Boysen; Nellemann, Hanne; Rasmussen, Finn; Morsing, Anni

    2016-01-01

    To evaluate and compare the diagnostic performance of whole-body planar bone scintigraphy (WBS), single photon emission computed tomography (SPECT), SPECT/low-dose computerized tomography (SPECT/ldCT) and SPECT/contrast enhanced diagnostic CT (SPECT/cdCT) in the staging of patients with advanced breast cancer. Seventy-eight patients with recurrence of biopsy-proven breast cancer and suspicion of disseminated disease were investigated with WBS, SPECT, SPECT/ldCT, SPECT/cdCT and MRI performed on the same day in this prospective study. Images were separately analysed in a blinded fashion by radiologists and nuclear medicine physicians regarding the presence of pathological findings. MRI served as reference standard. According to reference standard, 38 of 73 patients had bone metastases. The sensitivity was 87%, 87%, 79%, and 84% and specificity 63%, 71%, 63% and 83% for WBS, SPECT, SPECT/ldCT and SPECT/cdCT. A significantly increased specificity of SPECT/cdCT compared to WBS and SPECT/ldCT was found, and other parameters did not differ significantly between modalities. Additional two patients had bone metastases solely located outside the MRI scan field and seven patients had soft tissue metastases, but no skeletal changes on MRI. WBS, SPECT and SPECT/ldCT were less sensitive than MRI and equally specific for the detection of bone metastases in patients with advanced breast cancer. Based on our findings, we suggest that initial staging include WBS, MRI of the spine and CT for soft tissue evaluation. Further studies may clarify the potential benefits of whole-body MRI and 18F-NaF PET/CT or 18F-FDG PET/CT. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  20. Diagnostic accuracy of supine and prone thallium-201 stress myocardial perfusion single-photon emission computed tomography to detect coronary artery disease in inferior wall of left ventricle.

    PubMed

    Katayama, Takuji; Ogata, Nobuhiko; Tsuruya, Yoshio

    2008-05-01

    Prone thallium-201 ((201)Tl) myocardial perfusion single-photon emission computed tomography (SPECT) reduces false-positive rates when evaluating inferior wall abnormalities by minimizing diaphragmatic attenuation. The present study investigates the diagnostic validity of prone (201)Tl stress myocardial perfusion SPECT for detecting coronary artery disease in the inferior wall of the left ventricle in Japanese patients. Of the 104 consecutive patients who underwent (201)Tl stress myocardial perfusion SPECT to diagnose coronary artery disease, we evaluated 46 who underwent image acquisition in both the supine and prone positions, and coronary angiography within 3 months thereafter. Images were acquired in the routine supine position immediately following (201)Tl (111 MBq) injection and 4 h following early acquisition. Images were acquired in the prone position only during the early phase following supine acquisition. We evaluated the SPECT images of the inferior half segments of the left ventricle using a five-point defect scoring system. According to the coronary angiographic findings, we investigated the diagnostic accuracy of stress-rest supine, stress supine, stress prone, and combined supine-prone images. Reduced uptake in the stress supine image of the combined images was considered as attenuation when uptake was normal in the prone image. The sensitivity of the stress-rest supine, stress supine, stress prone, and stress-combined supine-prone images was 77%, 86%, 55%, and 55%, and the specificity was 71%, 54%, 79%, and 83%, respectively. Diagnostic accuracy was the highest in stress-rest supine images. Prone images tended to improve the specificity of detecting coronary artery disease in the inferior wall, but not diagnostic accuracy compared with stress-rest supine images because of decreased sensitivity.

  1. Noninvasive detection of matrix metalloproteinase-9 in atherosclerotic lesions using technetium-99m-labeled single-photon emission computed tomography in vivo.

    PubMed

    Wang, Zhongjuan; Deng, Gang; Zhang, Zhuiyang; Huang, Hongbo; Zhao, Yanjun

    2017-04-01

    Previous studies have suggested that matrix metalloproteinase (MMP) inhibitor uptake may offer a precise estimation of MMP activity in atherosclerotic lesions. In this study, we explored the feasibility of noninvasive detection of MMP-9 activity using technetium-99m-labeled matrix metalloproteinase-9 antibody (Tc-McAb) in vivo. ApoE-deficient (ApoE) atherosclerosis mice models (n=10) were induced through a high-cholesterol diet following ligation of their left common carotid artery. After 4 weeks, the models were verified through proton density-weighted and T2-weighted images obtained by MRI. C57BL/6 sham mice (n=8) were used as controls. In addition, normal mice (n=20) were used to characterize blood clearance. After radiolabeled McAb administration, single-photon emission computed tomography (SPECT) was performed. Subsequently, left common carotid arteries were harvested for ex-vivo autoradiograph imaging. Then, morphology and activity assays of MMP-9 were histologically and immunohistochemically examined. MRI showed higher signal intensities in the left common carotid arteries with irregular stenoses in the lumen of blood vessels in atherosclerosis mice models in vivo. Atherosclerotic lesions on left common carotid artery specimens were also clearly visualized using SPECT 2 h after Tc-McAb administration in vivo. Note that the radiochemistry purity of the Tc-McAb used was 85-95%. Biodistribution studies have shown that the clearance of Tc-McAb from blood was rapid. In addition, atherosclerotic lesions were clearly visualized on radioautography film shadows ex vivo. MMP-9 activities within the atherosclerotic lesions were noninvasively detected using Tc-labeled SPECT in vivo.

  2. Detection and Assessment Using Positron Emission Tomography of Genetically Determined Defects in Myocardial Fatty Acid Utilization. Final report, 8/1/93-6/30/97

    SciTech Connect

    Bergmann, Steven R.

    2000-04-09

    An approach using positron emission tomography (PET) was developed, validated and used to measure myocardial fatty acid metabolism in patients with inherited forms of heart failure. Abnormalities were correlated with the severity of the clinical illness. The approach developed was also shown to identify abnormalities in myocardial fatty acid metabolism in some patients with acquired forms of heart failure. The PET technique thus permits identification of abnormal fatty acid metabolism and provides an approach to evaluate the efficacy of interventional strategies.

  3. Positron Emission Tomography Imaging of Hypoxia

    PubMed Central

    Lapi, Suzanne E.; Voller, Thomas F.; Welch, Michael J.

    2009-01-01

    Synopsis Hypoxia imaging has applications in functional recovery in ischemic events such as stroke and myocardial ischemia, but especially in tumors in which hypoxia can be predictive of treatment response and overall prognosis. Recently there has been development of imaging agents utilizing positron emission tomography for non-invasive imaging of hypoxia. Many of these PET agents have come to the forefront of hypoxia imaging. Halogenated PET nitroimidazole imaging agents labeled with 18F (t1/2 = 110 m) and 124I (t1/2 = 110 m) have been under investigation for the last 25 years, with radiometal agents (64Cu-ATSM) being developed more recently. This review focuses on these positron emission tomography imaging agents for hypoxia. PMID:20046923

  4. A wavelet phase filter for emission tomography

    SciTech Connect

    Olsen, E.T.; Lin, B.

    1995-07-01

    The presence of a high level of noise is a characteristic in some tomographic imaging techniques such as positron emission tomography (PET). Wavelet methods can smooth out noise while preserving significant features of images. Mallat et al. proposed a wavelet based denoising scheme exploiting wavelet modulus maxima, but the scheme is sensitive to noise. In this study, the authors explore the properties of wavelet phase, with a focus on reconstruction of emission tomography images. Specifically, they show that the wavelet phase of regular Poisson noise under a Haar-type wavelet transform converges in distribution to a random variable uniformly distributed on [0, 2{pi}). They then propose three wavelet-phase-based denoising schemes which exploit this property: edge tracking, local phase variance thresholding, and scale phase variation thresholding. Some numerical results are also presented. The numerical experiments indicate that wavelet phase techniques show promise for wavelet based denoising methods.

  5. In Vivo Fibrillar β-Amyloid Detected Using [11C]PiB Positron Emission Tomography and Neuropathologic Assessment in Older Adults

    PubMed Central

    Sojkova, Jitka; Driscoll, Ira; Iacono, Diego; Zhou, Yun; Codispoti, Kari-Elise; Kraut, Michael A.; Ferrucci, Luigi; Pletnikova, Olga; Mathis, Chester A.; Klunk, William E.; O’Brien, Richard J.; Wong, Dean F.; Troncoso, Juan C.; Resnick, Susan M.

    2011-01-01

    Background In demented older adults, in vivo amyloid imaging shows agreement with diagnostic neuropathologic assessment of β-amyloid (Aβ). However, the extent of agreement in nondemented older adults remains unclear. Objective To compare Aβ quantified using in vivo carbon 11–labeled Pittsburgh Compound B positron emission tomography and postmortem neuropathologic assessment of Aβ in older adults. Design Case series. Setting Community-dwelling older adults who came to autopsy. Participants Five nondemented and 1 demented participant from the Baltimore Longitudinal Study of Aging. Main Outcome Measure Agreement between the mean cortical distribution volume ratio and the Consortium to Establish a Registry for AD (CERAD) neuritic plaque (NP) score used for pathologic diagnosis of Alzheimer disease. Results Of the 6 participants, 4 had moderate NPs, 2 had sparse or no detectable NPs, and 3 had microscopic findings of cerebral amyloid angiopathy at autopsy. On in vivo imaging, the mean cortical distribution volume ratio ranged from 0.96 to 1.59. Although there was agreement between in vivo amyloid imaging and CERAD NP scores in participants with either high or negligible Aβ levels in vivo, only limited agreement was observed among those with intermediate levels of Aβ. The best overall agreement was achieved at a distribution volume ratio of 1.2. Conclusions In older adults, variable agreement between in vivo imaging and CERAD NP score was observed. The limited agreement may, in part, reflect differences in typical measurements of Aβ using imaging compared with the CERAD neuropathologic protocol. Direct quantification of regional Aβ in relation to in vivo imaging is necessary to further enhance our understanding of the imaging–pathologic assessment correlation. PMID:21320990

  6. 99Tcm-MIBI single photon emission tomography (SPET) for detecting myocardial ischaemia and necrosis in patients with significant coronary artery disease.

    PubMed

    Sciammarella, M G; Fragasso, G; Gerundini, P; Maffioli, L; Cappelletti, A; Margonato, A; Savi, A; Chierchia, S

    1992-12-01

    The ability of 99Tcm-methoxyisobutylisonitrile (MIBI) single photon emission tomography (SPET) to detect myocardial ischaemia and necrosis was assessed in 56 patients (45 male, 11 female, aged 55 +/- 5 years), with clinically recognized ischaemic heart disease (IHD). All underwent coronary angiography (CA) and left ventriculography (LV). SPET images were obtained at rest and at peak exercise (Modified Bruce) 90 min after injection of 99Tcm-MIBI (650-850 MBq). Data were acquired in 30 min over 180 degrees (from 45 degrees RAO to 45 degrees LPO) with no correction for attenuation, using a 64 x 64 matrix. The presence of persistent (P) or reversible (R) perfusion defects (PD) was then correlated to the resting and exercise ECG and to the results of CA and LV. Of the 56 patients, 34 had reversible underperfusion (RPD), 46 persistent underperfusion (PPD) and 31 had both. The occurrence of RPD correlated well with the occurrence of exercise-induced ST segment depression and/or angina (27 patients of 34 patients, 79%) and with the presence of significant coronary artery disease (CAD) (33 of 44, 73%). In 45 of 46 patients (98%) PPD corresponded to akinetic or severely hypokinetic segments (LV) usually explored by ECG leads exhibiting diagnostic Q waves (42 of 46 patients, 91%). The scan was normal both at rest and after stress in four of 11 patients with no CAD, and in two of 45 patients with CAD. Finally, an abnormal resting scan was seen in seven of 11 patients with normal coronary arteries, of whom six had regional wall motion abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Comparisons of Positron Emission Tomography/Computed Tomography and Ultrasound Imaging for Detection of Internal Mammary Lymph Node Metastases in Patients With Breast Cancer and Pathologic Correlation by Ultrasound-Guided Biopsy Procedures.

    PubMed

    An, Yeong Yi; Kim, Sung Hun; Kang, Bong Joo; Lee, Ah Won

    2015-08-01

    To compare the diagnostic performance of [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and ultrasound imaging (US) with pathologic results obtained by US-guided biopsy and to evaluate the role of US in detecting internal mammary lymph node (LN) metastases in patients with breast cancer. Between January 2008 and December 2012, 37 patients with breast cancer (median age, 51.4 years; range, 40-79 years) underwent US-guided biopsy for suspected internal mammary LN metastases. Medical records, radiologic images, and reports were reviewed and correlated with pathologic results. The positive internal mammary LN metastasis rate was 78.4%. All biopsies were performed safely without major complications. Only 8.1% of obtained samples were unsatisfactory. There were statistically significant differences in lesion size (P = .0002), standardized uptake value on PET/CT (P = .0015), biopsy methods (P = .002), and specimen adequacy (P = .007) between metastatic and benign groups. Of the clinical factorsreviewed, only concurrent distant metastasis was correlated with internal mammary LN metastasis (P< .0001). Sensitivities for detecting internal mammary LN metastases were 76.7%, 96.7%, and 92.9% for initial US examinations, initial US combined with second-look US for initially missed cases, and PET/CT, respectively (P= .017). In a subgroup analysis, the only significant difference found was in sensitivities between initial and combined US (P = .019). In a receiver operating characteristic curve analysis, the area under the curve for PET/CT using standardized uptake criteria (0.87) was higher than that for US using size criteria (0.83); however, this difference was not significant. Although PET/CT is the best noninvasive method for evaluating internal mammary LN metastases, US is also useful if internal mammary LN evaluation is routine during standard US surveillance of patients with breast cancer. Additionally, US-guided biopsies could be

  8. Quantitative Positron Emission Tomography Imaging Detects Early Metabolic Remodeling in a Mouse Model of Pressure Overload Left Ventricular Hypertrophy in vivo

    PubMed Central

    Zhong, Min; Alonso, Clayton E.; Taegtmeyer, Heinrich; Kundu, Bijoy K.

    2013-01-01

    We proposed that metabolic remodeling in the form of increased myocardial glucose analogue 2-[18F] fluoro-2deoxy-D-glucose (FDG) uptake precedes and triggers the onset of severe contractile dysfunction in pressure overload left ventricular hypertrophy (LVH) in vivo. To test this hypothesis we used a mouse model of transverse aortic constriction (TAC) together with Positron Emission Tomography (PET) and assessed serial changes in cardiac metabolism and function over 7 days. Methods PET scans of 16 C57BL/6 male mice were performed using a microPET scanner under sevofluorane anesthesia. A 10-minute transmission scan was followed by a 60-minute dynamic FDG-PET scan with cardiac and respiratory gating. Blood glucose levels were measured before and after the emission scan. Transverse aortic constriction (TAC) and sham surgeries were performed after baseline imaging. Osmotic mini-pumps containing either propranolol (5 mg/kg/day) or vehicle alone were implanted subcutaneously at the end of surgery. Subsequent scans were taken at days 1 and 7 after surgery. A compartment model, in which the blood input function with spill-over and partial volume corrections and the metabolic rate constants in a 3-compartment model are simultaneously estimated, was used to determine the net myocardial FDG influx constant, Ki. The rate of myocardial glucose use, rMGU, was also computed. Estimations of the ejection fractions (EF) were based on the high resolution gated PET images Results Mice undergoing TAC surgery exhibited an increase in the Ki (580%) and glucose usage the day after surgery indicating early adaptive response. On day 7 the EF had decreased by 24% indicating a maladaptive response. Average Ki increases were not linearly associated with increases in rMGU. Ki exceeded rMGU by 29% in the TAC mice. TAC Mice treated with propranolol attenuated rate of FDG uptake, diminished mismatch between Ki and rMGU (9%) and rescued cardiac function. Conclusions Metabolic maladaptation precedes

  9. Anti-3-[18F]FACBC Positron Emission Tomography-Computerized Tomography and 111In-Capromab Pendetide Single Photon Emission Computerized Tomography-Computerized Tomography for Recurrent Prostate Carcinoma: Results of a Prospective Clinical Trial

    PubMed Central

    Schuster, David M.; Nieh, Peter T.; Jani, Ashesh B.; Amzat, Rianot; Bowman, F. DuBois; Halkar, Raghuveer K.; Master, Viraj A.; Nye, Jonathon A.; Odewole, Oluwaseun A.; Osunkoya, Adeboye O.; Savir-Baruch, Bital; Alaei-Taleghani, Pooneh; Goodman, Mark M.

    2014-01-01

    Purpose We prospectively evaluated the amino acid analogue positron emission tomography radiotracer anti-3-[18F]FACBC compared to ProstaScint® (111In-capromab pendetide) single photon emission computerized tomography-computerized tomography to detect recurrent prostate carcinoma. Materials and Methods A total of 93 patients met study inclusion criteria who underwent anti-3-[18F]FACBC positron emission tomography-computerized tomography plus 111In-capromab pendetide single photon emission computerized tomography-computerized tomography for suspected recurrent prostate carcinoma within 90 days. Reference standards were applied by a multidisciplinary board. We calculated diagnostic performance for detecting disease. Results In the 91 of 93 patients with sufficient data for a consensus on the presence or absence of prostate/bed disease anti-3-[18F]FACBC had 90.2% sensitivity, 40.0% specificity, 73.6% accuracy, 75.3% positive predictive value and 66.7% negative predictive value compared to 111In-capromab pendetide with 67.2%, 56.7%, 63.7%, 75.9% and 45.9%, respectively. In the 70 of 93 patients with a consensus on the presence or absence of extraprostatic disease anti-3-[18F]FACBC had 55.0% sensitivity, 96.7% specificity, 72.9% accuracy, 95.7% positive predictive value and 61.7% negative predictive value compared to 111In-capromabpendetide with10.0%, 86.7%, 42.9%, 50.0% and 41.9%, respectively. Of 77 index lesions used to prove positivity histological proof was obtained in 74 (96.1%). Anti-3-[18F]FACBC identified 14 more positive prostate bed recurrences (55 vs 41) and 18 more patients with extraprostatic involvement (22 vs 4). Anti-3-[18F]FACBC positron emission tomography-computerized tomography correctly up-staged 18 of 70 cases (25.7%) in which there was a consensus on the presence or absence of extraprostatic involvement. Conclusions Better diagnostic performance was noted for anti-3-[18F]FACBC positron emission tomography-computerized tomography than for 111In

  10. Reconstruction of Emission Tomography Data Using Origin Ensembles

    PubMed Central

    Sitek, Arkadiusz

    2011-01-01

    A new statistical reconstruction method based on origin ensembles (OE) for emission tomography (ET) is examined. Using a probability density function (pdf) derived from first principles, an ensemble expectation of numbers of detected event origins per voxel is determined. These numbers divided by sensitivities of voxels and acquisition time provide OE estimates of the voxel activities. The OE expectations are shown to be the same as expectations calculated using the complete–data space. The properties of the OE estimate are examined. It is shown that OE estimate approximates maximum likelihood (ML) estimate for conditions usually achieved in practical applications in emission tomography. Three numerical experiments with increasing complexity are used to validate theoretical findings and demonstrate similarities of ML and OE estimates. Recommendations for achieving improved accuracy and speed of OE reconstructions are provided. PMID:21147594

  11. Positron Emission Tomography: Principles, Technology, and Recent Developments

    NASA Astrophysics Data System (ADS)

    Ziegler, Sibylle I.

    2005-04-01

    Positron emission tomography (PET) is a nuclear medical imaging technique for quantitative measurement of physiologic parameters in vivo (an overview of principles and applications can be found in [P.E. Valk, et al., eds. Positron Emission Tomography. Basic Science and Clinical Practice. 2003, Springer: Heidelberg]), based on the detection of small amounts of posi-tron-emitter-labelled biologic molecules. Various radiotracers are available for neuro-logical, cardiological, and oncological applications in the clinic and in research proto-cols. This overview describes the basic principles, technology, and recent develop-ments in PET, followed by a section on the development of a tomograph with ava-lanche photodiodes dedicated for small animal imaging as an example of efforts in the domain of high resolution tomographs.

  12. Integrated Myocardial Perfusion Imaging Diagnostics Improve Detection of Functionally Significant Coronary Artery Stenosis by 13N-ammonia Positron Emission Tomography.

    PubMed

    Lee, Joo Myung; Kim, Chee Hae; Koo, Bon-Kwon; Hwang, Doyeon; Park, Jonghanne; Zhang, Jinlong; Tong, Yaliang; Jeon, Ki-Hyun; Bang, Ji-In; Suh, Minseok; Paeng, Jin Chul; Cheon, Gi Jeong; Na, Sang-Hoon; Ahn, Jung-Min; Park, Seung-Jung; Kim, Hyo-Soo

    2016-09-01

    Recent evidence suggests that the diagnostic accuracy of myocardial perfusion imaging is improved by quantifying stress myocardial blood flow (MBF) in absolute terms. We evaluated a comprehensive quantitative (13)N-ammonia positron emission tomography ((13)NH3-PET) diagnostic panel, including stress MBF, coronary flow reserve (CFR), and relative flow reserve (RFR) in conjunction with relative perfusion defect (PD) assessments to better detect functionally significant coronary artery stenosis. A total of 130 patients (307 vessels) with coronary artery disease underwent both (13)NH3-PET and invasive coronary angiography with fractional flow reserve (FFR) measurement. Diagnostic accuracy, optimal cut points, and discrimination indices of respective (13)NH3-PET quantitative measures were compared, with FFR as standard reference. The capacity to discern disease with stepwise addition of stress MBF, CFR, and RFR to qualitatively assessed relative PD was also gauged, using the category-free net reclassification index. All quantitative measures showed significant correlation with FFR (PET-derived CFR, r=0.388; stress MBF, r=0.496; and RFR, r=0.780; all P<0.001). Optimal respective cut points for FFR ≤0.8 and ≤0.75 were 1.99 and 1.84 mL/min per g for stress MBF and 2.12 and 2.00 for PET-derived CFR. Discrimination indices of quantitative measures that correlated with FFR ≤0.8 were all significantly higher than that of relative PD (area under the curve: 0.626, 0.730, 0.806, and 0.897 for relative PD, CFR, stress MBF, and RFR, respectively; overall comparison P<0.001). The capacity for functionally significant coronary stenosis was incrementally improved by the successive addition of CFR (net reclassification index=0.629), stress MBF (net reclassification index=0.950), and RFR (net reclassification index=1.253; all P<0.001) to relative PD. Integrating quantitative (13)NH3-PET measures with qualitative myocardial perfusion assessment provides superior diagnostic accuracy

  13. Therapy response evaluation with positron emission tomography-computed tomography.

    PubMed

    Segall, George M

    2010-12-01

    Positron emission tomography-computed tomography with F-18-fluorodeoxyglucose is widely used for evaluation of therapy response in patients with solid tumors but has not been as readily adopted in clinical trials because of the variability of acquisition and processing protocols and the absence of universal response criteria. Criteria proposed for clinical trials are difficult to apply in clinical practice, and gestalt impression is probably accurate in individual patients, especially with respect to the presence of progressive disease and complete response. Semiquantitative methods of determining tissue glucose metabolism, such as standard uptake value, can be a useful descriptor for levels of tissue glucose metabolism and changes in response to therapy if technical quality control measures are carefully maintained. The terms partial response, complete response, and progressive disease are best used in clinical trials in which the terms have specific meanings and precise definitions. In clinical practice, it may be better to use descriptive terminology agreed upon by imaging physicians and clinicians in their own practice.

  14. Single photon emission computed tomography-guided Cerenkov luminescence tomography

    NASA Astrophysics Data System (ADS)

    Hu, Zhenhua; Chen, Xueli; Liang, Jimin; Qu, Xiaochao; Chen, Duofang; Yang, Weidong; Wang, Jing; Cao, Feng; Tian, Jie

    2012-07-01

    Cerenkov luminescence tomography (CLT) has become a valuable tool for preclinical imaging because of its ability of reconstructing the three-dimensional distribution and activity of the radiopharmaceuticals. However, it is still far from a mature technology and suffers from relatively low spatial resolution due to the ill-posed inverse problem for the tomographic reconstruction. In this paper, we presented a single photon emission computed tomography (SPECT)-guided reconstruction method for CLT, in which a priori information of the permissible source region (PSR) from SPECT imaging results was incorporated to effectively reduce the ill-posedness of the inverse reconstruction problem. The performance of the method was first validated with the experimental reconstruction of an adult athymic nude mouse implanted with a Na131I radioactive source and an adult athymic nude mouse received an intravenous tail injection of Na131I. A tissue-mimic phantom based experiment was then conducted to illustrate the ability of the proposed method in resolving double sources. Compared with the traditional PSR strategy in which the PSR was determined by the surface flux distribution, the proposed method obtained much more accurate and encouraging localization and resolution results. Preliminary results showed that the proposed SPECT-guided reconstruction method was insensitive to the regularization methods and ignored the heterogeneity of tissues which can avoid the segmentation procedure of the organs.

  15. Positron Emission Tomography: Its 65 years

    NASA Astrophysics Data System (ADS)

    Del Guerra, A.; Belcari, N.; Bisogni, M.

    2016-04-01

    Positron Emission Tomography (PET) is a well-established imaging technique for in vivo molecular imaging. In this review after a brief history of PET there are presented its physical principles and the technology that has been developed for bringing PET from a bench experiment to a clinical indispensable instrument. The limitations and performance of the PET tomographs are discussed, both as for the hardware and software aspects. The status of art of clinical, pre-clinical and hybrid scanners (, PET/CT and PET/MR) is reported. Finally the actual trend and the recent and future technological developments are fully illustrated.

  16. Single-photon emission computed tomography (SPECT): Applications and potential

    SciTech Connect

    Holman, B.L.; Tumeh, S.S. )

    1990-01-26

    Single-photon emission computed tomography has received increasing attention as radiopharmaceuticals that reflect perfusion, metabolism, and receptor and cellular function have become widely available. Perfusion single-photon emission computed tomography of the brain provides functional information useful for the diagnosis and management of stroke, dementia, and epilepsy. Single-photon emission computed tomography has been applied to myocardial, skeletal, hepatic, and tumor scintigraphy, resulting in increased diagnostic accuracy over planar imaging because background activity and overlapping tissues interfere far less with activity from the target structure when tomographic techniques are used. Single-photon emission computed tomography is substantially less expensive and far more accessible than positron emission tomography and will become an increasingly attractive alternative for transferring the positron emission tomography technology to routine clinical use.

  17. Introduction to neutron stimulated emission computed tomography.

    PubMed

    Floyd, Carey E; Bender, Janelle E; Sharma, Amy C; Kapadia, Anuj; Xia, Jessie; Harrawood, Brian; Tourassi, Georgia D; Lo, Joseph Y; Crowell, Alexander; Howell, Calvin

    2006-07-21

    Neutron stimulated emission computed tomography (NSECT) is presented as a new technique for in vivo tomographic spectroscopic imaging. A full implementation of NSECT is intended to provide an elemental spectrum of the body or part of the body being interrogated at each voxel of a three-dimensional computed tomographic image. An external neutron beam illuminates the sample and some of these neutrons scatter inelastically, producing characteristic gamma emission from the scattering nuclei. These characteristic gamma rays are acquired by a gamma spectrometer and the emitting nucleus is identified by the emitted gamma energy. The neutron beam is scanned over the body in a geometry that allows for tomographic reconstruction. Tomographic images of each element in the spectrum can be reconstructed to represent the spatial distribution of elements within the sample. Here we offer proof of concept for the NSECT method, present the first single projection spectra acquired from multi-element phantoms, and discuss potential biomedical applications.

  18. Direct conversion semiconductor detectors in positron emission tomography

    NASA Astrophysics Data System (ADS)

    Cates, Joshua W.; Gu, Yi; Levin, Craig S.

    2015-05-01

    Semiconductor detectors are playing an increasing role in ongoing research to improve image resolution, contrast, and quantitative accuracy in preclinical applications of positron emission tomography (PET). These detectors serve as a medium for direct detection of annihilation photons. Early clinical translation of this technology has shown improvements in image quality and tumor delineation for head and neck cancers, relative to conventional scintillator-based systems. After a brief outline of the basics of PET imaging and the physical detection mechanisms for semiconductor detectors, an overview of ongoing detector development work is presented. The capabilities of semiconductor-based PET systems and the current state of these devices are discussed.

  19. [Detection of cerebral hypoperfusion using single photon emission computed tomography image analysis and statistical parametric mapping in patients with Parkinson's disease or progressive supranuclear palsy].

    PubMed

    Harada, Kengo; Saeki, Hiroshi; Matsuya, Eiji; Okita, Izumi

    2013-11-01

    We carried out differential diagnosis of brain blood flow images using single-photon emission computed tomography (SPECT) for patients with Parkinson's disease (PD) or progressive supranuclear paralysis (PSP) using statistical parametric mapping (SPM) and to whom we had applied anatomical standardization. We studied two groups and compared brain blood flow images using SPECT (N-isopropyl-4-iodoamphetamine [(123)I] hydrochloride injection, 222 MGq dosage i.v.). A total of 27 patients were studied using SPM: 18 with PD and 9 with PSP; humming bird sign on MRI was from moderate to medium. The decline of brain bloodstream in the PSP group was more notable in the midbrain, near the domain where the humming bird sign was observable, than in the PD group. The observable differences in brain bloodstream decline in the midbrain of PSP and PD patients suggest the potential usefulness of this technique's clinical application to distinction diagnosis.

  20. Positron Emission Tomography of the Heart

    DOE R&D Accomplishments Database

    Schelbert, H. R.; Phelps, M. E.; Kuhl, D. E.

    1979-01-01

    Positron emission computed tomography (PCT) represents an important new tool for the noninvasive evaluation and, more importantly, quantification of myocardial performance. Most currently available techniques permit assessment of only one aspect of cardiac function, i.e., myocardial perfusion by gamma scintillation camera imaging with Thallium-201 or left ventricular function by echocardiography or radionuclide angiocardiography. With PCT it may become possible to study all three major segments of myocardial performance, i.e., regional blood flow, mechanical function and, most importantly, myocardial metabolism. Each of these segments can either be evaluated separately or in combination. This report briefly describes the principles and technological advantages of the imaging device, reviews currently available radioactive tracers and how they can be employed for the assessment of flow, function and metabolism; and, lastly, discusses possible applications of PCT for the study of cardiac physiology or its potential role in the diagnosis of cardiac disease.

  1. Positron Emission Tomography with improved spatial resolution

    SciTech Connect

    Drukier, A.K.

    1990-04-01

    Applied Research Corporation (ARC) proposed the development of a new class of solid state detectors called Superconducting Granular Detectors (SGD). These new detectors permit considerable improvements in medical imaging, e.g. Positron Emission Tomography (PET). The biggest impact of this technique will be in imaging of the brain. It should permit better clinical diagnosis of such important diseases as Altzheimer's or schizophrenia. More specifically, we will develop an improved PET-imager; a spatial resolution 2 mm may be achievable with SGD. A time-of-flight capability(t {approx} 100 psec) will permit better contrast and facilitate 3D imaging. In the following, we describe the results of the first 9 months of the development.

  2. Quantitative positron emission tomography in brain research.

    PubMed

    Heurling, Kerstin; Leuzy, Antoine; Jonasson, My; Frick, Andreas; Zimmer, Eduardo R; Nordberg, Agneta; Lubberink, Mark

    2017-09-01

    The application of positron emission tomography (PET) in brain research has increased substantially during the past 20years, and is still growing. PET provides a unique insight into physiological and pathological processes in vivo. In this article we introduce the fundamentals of PET, and the methods available for acquiring quantitative estimates of the parameters of interest. A short introduction to different areas of application is also given, including basic research of brain function and in neurology, psychiatry, drug receptor occupancy studies, and its application in diagnostics of neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. Our aim is to inform the unfamiliar reader of the underlying basics and potential applications of PET, hoping to inspire the reader into considering how the technique could be of benefit for his or her own research. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Imaging local brain function with emission computed tomography

    SciTech Connect

    Kuhl, D.E.

    1984-03-01

    Positron emission tomography (PET) using /sup 18/F-fluorodeoxyglucose (FDG) was used to map local cerebral glucose utilization in the study of local cerebral function. This information differs fundamentally from structural assessment by means of computed tomography (CT). In normal human volunteers, the FDG scan was used to determine the cerebral metabolic response to conrolled sensory stimulation and the effects of aging. Cerebral metabolic patterns are distinctive among depressed and demented elderly patients. The FDG scan appears normal in the depressed patient, studded with multiple metabolic defects in patients with multiple infarct dementia, and in the patients with Alzheimer disease, metabolism is particularly reduced in the parietal cortex, but only slightly reduced in the caudate and thalamus. The interictal FDG scan effectively detects hypometabolic brain zones that are sites of onset for seizures in patients with partial epilepsy, even though these zones usually appear normal on CT scans. The future prospects of PET are discussed.

  4. Positron emission tomography and single-photon emission computed tomography in substance abuse research.

    PubMed

    Volkow, Nora D; Fowler, Joanna S; Wang, Gene-Jack

    2003-04-01

    Many advances in the conceptualization of addiction as a disease of the brain have come from the application of imaging technologies directly in the human drug abuser. New knowledge has been driven by advances in radiotracer design and chemistry and positron emission tomography (PET) and single-photon emission computed tomography (SPECT) instrumentation and the integration of these scientific tools with the tools of biochemistry, pharmacology, and medicine. This topic cuts across the medical specialties of neurology, psychiatry, oncology, and cardiology because of the high medical, social, and economic toll that drugs of abuse, including the legal drugs, cigarettes and alcohol, take on society. This article highlights recent advances in the use of PET and SPECT imaging to measure the pharmacokinetic and pharmacodynamic effects of drugs of abuse on the human brain.

  5. Calorimetry in Medical Applications: Single-Photon Emission Computed Tomography and Positron Emission Tomography

    SciTech Connect

    Chen, C.-T.

    2006-10-27

    Positron emission tomography (PET) and single-photon emission computed tomography (SPECT), two nuclear medicine imaging modalities broadly used in clinics and research, share many common instrumentation, detector, and electronics technology platforms with calorimetry in high-energy physics, astronomy, and other physics sciences. Historically, advances made in calorimetry had played major roles in the development of novel approaches and critical technologies essential to the evolution of PET and SPECT. There have also been examples in which PET/SPECT developments had led to new techniques in calorimetry for other application areas. In recent years, several innovations have propelled advances in both calorimetry in general and PET/SPECT in particular. Examples include time-of-flight (TOF) measurements, silicon photomultipliers (SiPMs), etc.

  6. Teflon laryngeal granuloma presenting as laryngeal cancer on combined positron emission tomography and computed tomography scanning.

    PubMed

    Ondik, M P; Kang, J; Bayerl, M G; Bruno, M; Goldenberg, D

    2009-05-01

    Positron emission tomography with 18F-fluorodeoxyglucose (18FDG) has been increasingly used in the diagnostic investigation of patients with neoplasms of the head and neck. Positron emission tomography and computed tomography have also proven useful for surveillance of thyroid cancers that no longer concentrate radioiodine. However, certain benign or inflammatory lesions can also accumulate 18F-fluorodeoxyglucose and lead to misdiagnosis. We review and discuss the pitfalls of using positron emission tomography and computed tomography for surveillance of thyroid cancer. We present the case of a 48-year-old woman who was diagnosed with a laryngeal neoplasm on integrated positron emission tomography and computed tomography scanning, after a routine ultrasound demonstrated an enlarged thyroid nodule. On physical examination, she had a laryngeal mass overlying an immobile vocal fold. The mass was biopsied and found to harbour a Teflon granuloma. Positron emission tomography positive Teflon granulomas have previously been reported in the nasopharynx and vocal folds, and should be considered in the differential diagnosis of patients who have undergone prior surgery involving Teflon injection. It is important for otolaryngologists and radiologists to recognise potential causes of false positive positron emission tomography and computed tomography findings, including Teflon granulomas.

  7. Positron emission tomography with fluorodeoxyglucose to evaluate tumor response and control after radiation therapy

    SciTech Connect

    Chaiken, L.; Juillard, G.; Rege, S.; Hoh, C.; Choi, Y.; Jabour, B.; Hawkins, R.; Parker, R. )

    1993-09-20

    Following radiation therapy, evaluation of viable tumor can often be difficult with anatomic imaging criteria (tumor size alone). In this study, the utility of biochemical imaging with the glucose analog 2-[F-18]fluoro-2-deoxy-D-glucose and positron emission tomography was investigated in patients with radiation therapy. Post-radiation positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose studies were done in all patients, with 9 head and neck patients receiving pre-radiation positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose scans as well. Results were correlated with other imaging techniques and pathology. Positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose detected head and neck primary tumors and lymph node metastases in all nine pre-radiation scans, while magnetic resonance imaging failed to detect two primary tumors. Serial positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose showed a significant decrease in tumor activity after radiation therapy, compared to pre-radiation levels, (p < 0.05), except for two patients with increased uptake at the primary site. Biopsies of these two patients showed persistent/recurrent disease after radiation therapy, which was not detected by magnetic resonance imaging. Six additional head and neck patients, with suspicious examination and inconclusive magnetic resonance imaging, were imaged with positron emission tomography after radiation therapy only. Five patients had increased positron emission tomography activity, with corresponding biopsies positive in four patients, and negative in one patient with clinically worsening symptoms. The remaining sixth patient had minimal and stable positron emission tomography uptake, and is improving clinically. Four patients had mammogram findings suspicious for recurrence after conservation treatment for breast cancer. 40 refs., 6 figs., 1 tab.

  8. Multifocal, persistent cardiac uptake of [18-F]-fluoro-deoxy-glucose detected by positron emission tomography in patients with acute myocardial infarction.

    PubMed

    Godino, Cosmo; Messa, Cristina; Gianolli, Luigi; Landoni, Claudio; Margonato, Alberto; Cera, Michela; Stefano, Coli; Cianflone, Domenico; Fazio, Ferruccio; Maseri, Attilio

    2008-11-01

    Inflammation appears to be important in the pathogenesis of acute myocardial infarction (AMI). Cardiac [18-F]-fluoro-deoxy-glucose (FDG) uptake by positron emission tomography/computed tomography (PET/CT)-scan was investigated in 12 fasting patients with first AMI (FAMI) single-vessel disease after successful primary percutaneous coronary intervention and at 9 weeks follow-up, and in 12 controls. The average FDG uptake (aFDGu) of the 28 left ventricular (LV) wall segments defined on the PET/CT images of the 12 FAMI patients was 1.28+/-0.57-fold higher than the activity present in the LV cavity. By contrast, the aFDGu of the 12 controls was 0.70+/-22 (p<0.001). The segmental aFDGu in the FAMI was multifocal in both the culprit and non-culprit segments; it was less than LV cavity activity in 38%, 1-2-fold greater in 51.8% and more than 2-fold greater in 10.2%. At follow-up, aFDGu was significantly increased in both culprit and non-culprit segments (1.69+/-1.15, p<0.001). Statistically significant differences between FAMI and controls patients were only found for interleukin-6 plasma levels on admission (11.3+/-7.7 pg/ml vs 2.2+/-1.3 pg/ml; p<0.004). Multifocal, non-infarct related, cardiac-FDG-uptake occurred immediately after AMI and persisted at follow-up. The cause of these striking and consistent findings is still speculative.

  9. Concurrent Ultrasonic Tomography and Acoustic Emission in Solid Materials

    NASA Astrophysics Data System (ADS)

    Chow, Thomas M.

    A series of experiments were performed to detect stress induced changes in the elastic properties of various solid materials. A technique was developed where these changes were monitored concurrently by two methods, ultrasonic tomography and acoustic emission monitoring. This thesis discusses some experiments in which acoustic emission (AE) and ultrasonic tomography were performed on various samples of solid materials including rocks, concrete, metals, and fibre reinforced composites. Three separate techniques were used to induce stress in these samples. Disk shaped samples were subject to stress via diametral loading using an indirect tensile test geometry. Cylindrical samples of rocks and concrete were subject to hydraulic fracture tests, and rectangular samples of fibre reinforced composite were subject to direct tensile loading. The majority of the samples were elastically anisotropic. Full waveform acoustic emission and tomographic data were collected while these samples were under load to give information concerning changes in the structure of the material as it was undergoing stress change and/or failure. Analysis of this data indicates that AE and tomographic techniques mutually compliment each other to give a view of the stress induced elastic changes in the tested samples.

  10. The diagnostic possibilities of positron emission tomography (PET): applications in oral and maxillofacial buccal oncology.

    PubMed

    Carranza-Pelegrina, Daniela; Lomeña-Caballero, Francisco; Soler-Peter, Marina; Berini-Aytés, Leonardo; Gay-Escoda, Cosme

    2005-01-01

    The principles of positron emission tomography (PET), recently introduced as a diagnostic procedure into the health sciences, are described. The principle clinical applications apply to a particular group of specialties: cardiology, neurology, psychiatry, and above all oncology. Positron emission tomography is a non-invasive diagnostic imaging technique with clinical applications. It is an excellent tool for the study of the stage and possible malignancy of tumors of head and neck, the detection of otherwise clinically indeterminate metastases and lymphadenopathies, and likewise for the diagnosis of relapses. The only tracer with any practical clinical application is fluor-desoxyglucosa-F18 (FDG). PET detects the intense accumulation of FDG produced in malignant tumors due to the increased glycolytic rate of the neoplastic cells. With the introduction of hybrid systems that combine computerized tomography or magnetic resonance with positron emission tomography, important advances are being made in the diagnosis and follow-up of oncologic pathology of head and neck.

  11. Association Between Pulmonary Uptake of Fluorodeoxyglucose Detected by Positron Emission Tomography Scanning After Radiation Therapy for Non-Small-Cell Lung Cancer and Radiation Pneumonitis

    SciTech Connect

    Mac Manus, Michael P.; Ding Zhe; Hogg, Annette; Herschtal, Alan; Binns, David; Ball, David L.; Hicks, Rodney J.

    2011-08-01

    Purpose: To study the relationship between fluorodeoxyglucose (FDG) uptake in pulmonary tissue after radical radiation therapy (RT) and the presence and severity of radiation pneumonitis. Methods and Materials: In 88 consecutive patients, {sup 18}F-FDG-positron emission tomography was performed at a median of 70 days after completion of RT. Patients received 60 Gy in 30 fractions, and all but 15 had concurrent platinum-based chemotherapy. RT-induced pulmonary inflammatory changes occurring within the radiation treatment volume were scored, using a visual (0 to 3) radiotoxicity grading scale, by an observer blinded to the presence or absence of clinical radiation pneumonitis. Radiation pneumonitis was retrospectively graded using the Radiation Therapy Oncology Group (RTOG) scale by an observer blinded to the PET radiotoxicity score. Results: There was a significant association between the worst RTOG pneumonitis grade occurring at any time after RT and the positron emission tomograph (PET) radiotoxicity grade (one-sided p = 0.033). The worst RTOG pneumonitis grade occurring after the PET scan was also associated with the PET radiotoxicity grade (one-sided p = 0.035). For every one-level increase in the PET toxicity scale, the risk of a higher RTOG radiation pneumonitis score increased by approximately 40%. The PET radiotoxicity score showed no significant correlation with the duration of radiation pneumonitis. Conclusions: The intensity of FDG uptake in pulmonary tissue after RT determined using a simple visual scoring system showed significant correlation with the presence and severity of radiation pneumonitis. {sup 18}F-FDG-PET may be useful in the prediction, diagnosis and therapeutic monitoring of radiation pneumonitis.

  12. Detection of cerebral amyloid angiopathy by 3-T magnetic resonance imaging and amyloid positron emission tomography in a patient with subcortical ischaemic vascular dementia.

    PubMed

    Kida, Hirotaka; Satoh, Masayuki; Ii, Yuichiro; Fukuyama, Hidenao; Maeda, Masayuki; Tomimoto, Hidekazu

    2017-01-01

    The patient was an 81-year-old man who had been treated for hypertension for several decades. In 2012, he developed gait disturbance and mild amnesia. One year later, his gait disturbance worsened, and he developed urinary incontinence. Conventional brain magnetic resonance imaging using T 2 -weighted images and fluid-attenuated inversion recovery showed multiple lacunar infarctions. These findings fulfilled the diagnostic criteria for subcortical ischaemic vascular dementia. However, susceptibility weighted imaging showed multiple lobar microbleeds in the bilateral occipitoparietal lobes, and double inversion recovery and 3-D fluid-attenuated inversion recovery images on 3-T magnetic resonance imaging revealed cortical microinfarctions in the left parietal-temporo-occipito region. Pittsburgh compound B-positron emission tomography revealed diffuse uptake in the cerebral cortex. Therefore, we diagnosed the patient with subcortical ischaemic vascular dementia associated with Alzheimer's disease. The use of the double inversion recovery and susceptibility weighted imaging on 3-T magnetic resonance imaging may be a supplemental strategy for diagnosing cerebral amyloid angiopathy, which is closely associated with Alzheimer's disease.

  13. Resistive plate chambers in positron emission tomography

    NASA Astrophysics Data System (ADS)

    Crespo, Paulo; Blanco, Alberto; Couceiro, Miguel; Ferreira, Nuno C.; Lopes, Luís; Martins, Paulo; Ferreira Marques, Rui; Fonte, Paulo

    2013-07-01

    Resistive plate chambers (RPC) were originally deployed for high energy physics. Realizing how their properties match the needs of nuclear medicine, a LIP team proposed applying RPCs to both preclinical and clinical positron emission tomography (RPC-PET). We show a large-area RPC-PET simulated scanner covering an axial length of 2.4m —slightly superior to the height of the human body— allowing for whole-body, single-bed RPC-PET acquisitions. Simulations following NEMA (National Electrical Manufacturers Association, USA) protocols yield a system sensitivity at least one order of magnitude larger than present-day, commercial PET systems. Reconstruction of whole-body simulated data is feasible by using a dedicated, direct time-of-flight-based algorithm implemented onto an ordered subsets estimation maximization parallelized strategy. Whole-body RPC-PET patient images following the injection of only 2mCi of 18-fluorodesoxyglucose (FDG) are expected to be ready 7 minutes after the 6 minutes necessary for data acquisition. This compares to the 10-20mCi FDG presently injected for a PET scan, and to the uncomfortable 20-30minutes necessary for its data acquisition. In the preclinical field, two fully instrumented detector heads have been assembled aiming at a four-head-based, small-animal RPC-PET system. Images of a disk-shaped and a needle-like 22Na source show unprecedented sub-millimeter spatial resolution.

  14. Positron-emission tomography and personality disorders.

    PubMed

    Goyer, P F; Andreason, P J; Semple, W E; Clayton, A H; King, A C; Compton-Toth, B A; Schulz, S C; Cohen, R M

    1994-02-01

    This study used positron-emission tomography to examine cerebral metabolic rates of glucose (CMRG) in 17 patients with DSM III-R diagnoses of personality disorder. Within the group of 17 personality disorder patients, there was a significant inverse correlation between a life history of aggressive impulse difficulties and regional CMRG in the frontal cortex of the transaxial plane approximately 40 mm above the canthomeatal line (CML) (r = -.56, p = 0.17). Diagnostic groups included antisocial (n = 6), borderline (n = 6), dependent (n = 2), and narcissistic (n = 3). Regional CMRG in the six antisocial patients and in the six borderline patients was compared to a control group of 43 subjects using an analysis of covariance with age and sex as covariates. In the borderline personality disorder group, there was a significant decrease in frontal cortex metabolism in the transaxial plane approximately 81 mm above the CML and a significant increase in the transaxial plane approximately 53 mm above the CML (F[1,45] = 8.65, p = .005; and F[1,45] = 7.68, p = .008, respectively.

  15. A Review on Segmentation of Positron Emission Tomography Images

    PubMed Central

    Foster, Brent; Bagci, Ulas; Mansoor, Awais; Xu, Ziyue; Mollura, Daniel J.

    2014-01-01

    Positron Emission Tomography (PET), a non-invasive functional imaging method at the molecular level, images the distribution of biologically targeted radiotracers with high sensitivity. PET imaging provides detailed quantitative information about many diseases and is often used to evaluate inflammation, infection, and cancer by detecting emitted photons from a radiotracer localized to abnormal cells. In order to differentiate abnormal tissue from surrounding areas in PET images, image segmentation methods play a vital role; therefore, accurate image segmentation is often necessary for proper disease detection, diagnosis, treatment planning, and follow-ups. In this review paper, we present state-of-the-art PET image segmentation methods, as well as the recent advances in image segmentation techniques. In order to make this manuscript self-contained, we also briefly explain the fundamentals of PET imaging, the challenges of diagnostic PET image analysis, and the effects of these challenges on the segmentation results. PMID:24845019

  16. MR-IMPACT II: Magnetic Resonance Imaging for Myocardial Perfusion Assessment in Coronary artery disease Trial: perfusion-cardiac magnetic resonance vs. single-photon emission computed tomography for the detection of coronary artery disease: a comparative multicentre, multivendor trial.

    PubMed

    Schwitter, Juerg; Wacker, Christian M; Wilke, Norbert; Al-Saadi, Nidal; Sauer, Ekkehart; Huettle, Kalman; Schönberg, Stefan O; Luchner, Andreas; Strohm, Oliver; Ahlstrom, Hakan; Dill, Thorsten; Hoebel, Nadja; Simor, Tamas

    2013-03-01

    Perfusion-cardiac magnetic resonance (CMR) has emerged as a potential alternative to single-photon emission computed tomography (SPECT) to assess myocardial ischaemia non-invasively. The goal was to compare the diagnostic performance of perfusion-CMR and SPECT for the detection of coronary artery disease (CAD) using conventional X-ray coronary angiography (CXA) as the reference standard. In this multivendor trial, 533 patients, eligible for CXA or SPECT, were enrolled in 33 centres (USA and Europe) with 515 patients receiving MR contrast medium. Single-photon emission computed tomography and CXA were performed within 4 weeks before or after CMR in all patients. The prevalence of CAD in the sample was 49%. Drop-out rates for CMR and SPECT were 5.6 and 3.7%, respectively (P = 0.21). The primary endpoint was non-inferiority of CMR vs. SPECT for both sensitivity and specificity for the detection of CAD. Readers were blinded vs. clinical data, CXA, and imaging results. As a secondary endpoint, the safety profile of the CMR examination was evaluated. For CMR and SPECT, the sensitivity scores were 0.67 and 0.59, respectively, with the lower confidence level for the difference of +0.02, indicating superiority of CMR over SPECT. The specificity scores for CMR and SPECT were 0.61 and 0.72, respectively (lower confidence level for the difference: -0.17), indicating inferiority of CMR vs. SPECT. No severe adverse events occurred in the 515 patients. In this large multicentre, multivendor study, the sensitivity of perfusion-CMR to detect CAD was superior to SPECT, while its specificity was inferior to SPECT. Cardiac magnetic resonance is a safe alternative to SPECT to detect perfusion deficits in CAD.

  17. The Role of Chemistry in Positron Emission Tomography.

    ERIC Educational Resources Information Center

    Feliu, Anthony L.

    1988-01-01

    Investigates use of positron emission tomography (PET) to study in-vivo metabolic processes. Discusses methodology of PET and medical uses. Outlines the production of different radioisotopes used in PET radiotracers. Includes selected bibliography. (ML)

  18. The Role of Chemistry in Positron Emission Tomography.

    ERIC Educational Resources Information Center

    Feliu, Anthony L.

    1988-01-01

    Investigates use of positron emission tomography (PET) to study in-vivo metabolic processes. Discusses methodology of PET and medical uses. Outlines the production of different radioisotopes used in PET radiotracers. Includes selected bibliography. (ML)

  19. SPECT (Single-Photon Emission Computerized Tomography) Scan

    MedlinePlus

    SPECT scan Overview By Mayo Clinic Staff A single-photon emission computerized tomography (SPECT) scan lets your doctor analyze the function of some of your internal organs. A SPECT scan is a type of nuclear imaging test, ...

  20. Myocardial blood flow quantification for evaluation of coronary artery disease by positron emission tomography, cardiac magnetic resonance imaging, and computed tomography.

    PubMed

    Waller, Alfonso H; Blankstein, Ron; Kwong, Raymond Y; Di Carli, Marcelo F

    2014-05-01

    The noninvasive detection of the presence and functional significance of coronary artery stenosis is important in the diagnosis, risk assessment, and management of patients with known or suspected coronary artery disease. Quantitative assessment of myocardial perfusion can provide an objective and reproducible estimate of myocardial ischemia and risk prediction. Positron emission tomography, cardiac magnetic resonance, and cardiac computed tomography perfusion are modalities capable of measuring myocardial blood flow and coronary flow reserve. In this review, we will discuss the technical aspects of quantitative myocardial perfusion imaging with positron emission tomography, cardiac magnetic resonance imaging, and computed tomography, and its emerging clinical applications.

  1. Myocardial Blood Flow Quantification for Evaluation of Coronary Artery Disease by Positron Emission Tomography, Cardiac Magnetic Resonance Imaging, and Computed Tomography

    PubMed Central

    Waller, Alfonso H.; Blankstein, Ron; Kwong, Raymond Y.; Di Carli, Marcelo F.

    2014-01-01

    The noninvasive detection of the presence and functional significance of coronary artery stenosis is important in the diagnosis, risk assessment, and management of patients with known or suspected coronary artery disease. Quantitative assessment of myocardial perfusion can provide an objective and reproducible estimate of myocardial ischemia and risk prediction. Positron emission tomography, cardiac magnetic resonance, and cardiac computed tomography perfusion are modalities capable of measuring myocardial blood flow and coronary flow reserve. In this review, we will discuss the technical aspects of quantitative myocardial perfusion imaging with positron emission tomography, cardiac magnetic resonance imaging and computed tomography, and its emerging clinical applications. PMID:24718671

  2. Laparoscopic extended pelvic lymph node (LN) dissection as validation of the performance of [(11) C]-acetate positron emission tomography/computer tomography in the detection of LN metastasis in intermediate- and high-risk prostate cancer.

    PubMed

    Daouacher, Georgios; von Below, Catrin; Gestblom, Charlotta; Ahlström, Håkan; Grzegorek, Rafael; Wassberg, Cecilia; Sörensen, Jens; Waldén, Mauritz

    2016-07-01

    To evaluate the accuracy of the radiopharmaceutical [(11) C]-acetate combined with positron emission tomography/computer tomography (acetate-PET/CT) in lymph node (LN) staging in newly diagnosed prostate cancer cases. A second aim was to evaluate the potential discriminative properties of acetate-PET/CT in clinical routine. In a prospective comparative study, from July 2010 to June 2013, 53 men with newly histologically diagnosed intermediate- or high-risk prostate cancer underwent acetate-PET/CT investigation at one regional centre before laparoscopic extended pelvic LN dissection (ePLND) at one referral centre. The sensitivity, specificity and accuracy of acetate-PET/CT were calculated. Comparisons were made between true-positive and false-negative PET/CT cases to identify differences in the clinical parameters: PSA level, Gleason status, lymph metastasis burden and size, calculated risk of LN involvement, and curative treatment decisions. In all, 26 patients had surgically/histologically confirmed LN metastasis (LN+). Acetate-PET/CT was true positive in 10 patients, false positive in one, false negative in 16, and true negative in 26. The individual sensitivity was 38%, specificity 96%, and accuracy 68%. The acetate-PET/CT positive cases had significantly more involved LNs (mean 7.9 vs 2.4, P < 0.001) with larger cancer diameters (14.1 vs 4.9 mm, P = 0.001) and fewer eventually had treatment with curative intent (40% vs 94%, P <0.005), although we lack long-term outcome data. Acetate-PET/CT has too low a sensitivity for routine LN staging but the specificity is high. The acetate-PET/CT positive cases have a very high burden of LN spread. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

  3. Detection of Local, Regional, and Distant Recurrence in Patients With PSA Relapse After External-Beam Radiotherapy Using {sup 11}C-Choline Positron Emission Tomography

    SciTech Connect

    Breeuwsma, Anthonius J.; Pruim, Jan; Bergh, Alphons C.M. van den; Leliveld, Anna M.; Nijman, Rien J.M.; Dierckx, Rudi A.J.O.; Jong, Igle J. de

    2010-05-01

    Purpose: An elevated serum prostate-specific antigen (PSA) level cannot distinguish between local-regional recurrences and the presence of distant metastases after treatment with curative intent for prostate cancer. With the advent of salvage treatment such as cryotherapy, it has become important to localize the site of recurrence (local or distant). In this study, the potential of {sup 11}C-choline positron emission tomography (PET) to identify site of recurrence was investigated in patients with rising PSA after external-beam radiotherapy (EBRT). Methods and Materials: Seventy patients with histologically proven prostate cancer treated with EBRT and showing biochemical recurrence as defined by American Society for Therapeutic Radiology and Oncology consensus statement and 10 patients without recurrence underwent a PET scan using 400 MBq {sup 11}C-choline intravenously. Biopsy-proven histology from the site of suspicion, findings with other imaging modalities, clinical follow-up and/or response to adjuvant therapy were used as comparative references. Results: None of the 10 patients without biochemical recurrence had a positive PET scan. Fifty-seven of 70 patients with biochemical recurrence (median PSA 9.1 ng/mL; mean PSA 12.3 ng/mL) showed an abnormal uptake pattern (sensitivity 81%). The site of recurrence was only local in 41 of 57 patients (mean PSA 11.1 ng/mL at scan), locoregionally and/or distant in 16 of 57 patients (mean PSA 17.7 ng/mL). Overall the positive predictive value and negative predictive value for {sup 11}C-choline PET scan were 1.0 and 0.44 respectively. Accuracy was 84%. Conclusions: {sup 11}C-choline PET scan is a sensitive technique to identify the site of recurrence in patients with PSA relapse after EBRT for prostate cancer.

  4. Clinical and cost implications of amyloid beta detection with amyloid beta positron emission tomography imaging in early Alzheimer's disease - the case of florbetapir.

    PubMed

    Hornberger, John; Bae, Jay; Watson, Ian; Johnston, Joe; Happich, Michael

    2017-04-01

    Amyloid beta (Aβ) positron emission tomography (PET) imaging helps estimate Aβ neuritic plaque density in patients with cognitive impairment who are under evaluation for Alzheimer's disease (AD). This study aims to evaluate the cost-effectiveness of the Aβ-PET scan as an adjunct to standard diagnostic assessment for diagnosis of AD in France, using florbetapir as an example. A state-transition probability analysis was developed adopting the French Health Technology Assessment (HTA) perspective per guidance. Parameters included test characteristics, rate of cognitive decline, treatment effect, costs, and quality of life. Additional scenarios assessed the validity of the analytical framework, including: (1) earlier evaluation/treatment; (2) cerebrospinal fluid (CSF) as a comparator; and (3) use of other diagnostic procedures. Outputs included differences in quality-adjusted life years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). All benefits and costs were discounted for time preferences. Sensitivity analyses were performed to assess the robustness of findings and key influencers of outcomes. Aβ-PET used as an adjunct to standard diagnostic assessment increased QALYs by 0.021 years and 10 year costs by €470 per patient. The ICER was €21,888 per QALY gained compared to standard diagnostic assessment alone. When compared with CSF, Aβ-PET costs €24,084 per QALY gained. In other scenarios, Aβ-PET was consistently cost-effective relative to the commonly used affordability threshold (€40,000 per QALY). Over 95% of simulations in the sensitivity analysis were cost-effective. Aβ-PET is projected to affordably increase QALYs from the French HTA perspective per guidance over a range of clinical scenarios, comparators, and input parameters.

  5. Positron emission tomography detects greater blood flow and less blood flow heterogeneity in the exercising skeletal muscles of old compared with young men during fatiguing contractions.

    PubMed

    Rudroff, Thorsten; Weissman, Jessica A; Bucci, Marco; Seppänen, Marko; Kaskinoro, Kimmo; Heinonen, Ilkka; Kalliokoski, Kari K

    2014-01-15

    The purpose of this study was to investigate blood flow and its heterogeneity within and among the knee muscles in five young (26 ± 6 years) and five old (77 ± 6 years) healthy men with similar levels of physical activity while they performed two types of submaximal fatiguing isometric contraction that required either force or position control. Positron emission tomography (PET) and [(15)O]-H2O were used to determine blood flow at 2 min (beginning) and 12 min (end) after the start of the tasks. Young and old men had similar maximal forces and endurance times for the fatiguing tasks. Although muscle volumes were lower in the older subjects, total muscle blood flow was similar in both groups (young men: 25.8 ± 12.6 ml min(-1); old men: 25.1 ± 15.4 ml min(-1); age main effect, P = 0.77) as blood flow per unit mass of muscle in the exercising knee extensors was greater in the older (12.5 ± 6.2 ml min(-1) (100 g)(-1)) than the younger (8.6 ± 3.6 ml min(-1) (100 g)(-1)) men (age main effect, P = 0.001). Further, blood flow heterogeneity in the exercising knee extensors was significantly lower in the older (56 ± 27%) than the younger (67 ± 34%) men. Together, these data show that although skeletal muscles are smaller in older subjects, based on the intact neural drive to the muscle and the greater, less heterogeneous blood flow per gram of muscle, old fit muscle achieves adequate exercise hyperaemia.

  6. Future direction of renal positron emission tomography.

    PubMed

    Szabo, Zsolt; Xia, Jinsong; Mathews, William B; Brown, Phillip R

    2006-01-01

    Positron emission tomography (PET) is perfectly suited for quantitative imaging of the kidneys, and the recent improvements in detector technology, computer hardware, and image processing software add to its appeal. Multiple positron emitting radioisotopes can be used for renal imaging. Some, including carbon-11, nitrogen-13, and oxygen-15, can be used at institutions with an on-site cyclotron. Other radioisotopes that may be even more useful in a clinical setting are those that either can be obtained from radionuclide generators (rubidium-82, copper-62) or have a sufficiently long half-life for transportation (fluorine-18). The clinical use of functional renal PET studies (blood flow, glomerular filtration rate) has been slow, in part because of the success of concurrent technologies, including single-photon emission computed tomography (SPECT) and planar gamma camera imaging. Renal blood flow studies can be performed with O-15-labeled water, N-13-labeled ammonia, rubidium-82, and copper-labeled PTSM. With these tracers, renal blood flow can be quantified using a modified microsphere kinetic model. Glomerular filtration can be imaged and quantified with gallium-68 EDTA or cobalt-55 EDTA. Measurements of renal blood flow with PET have potential applications in renovascular disease, in transplant rejection or acute tubular necrosis, in drug-induced nephropathies, ureteral obstruction, before and after revascularization, and before and after the placement of ureteral stents. The most important clinical application for imaging glomerular function with PET would be renovascular hypertension. Molecular imaging of the kidneys with PET is rather limited. At present, research is focused on the investigation of metabolism (acetate), membrane transporters (organic cation and anion transporters, pepT1 and pepT2, GLUT, SGLT), enzymes (ACE), and receptors (AT1R). Because many nephrological and urological disorders are initiated at the molecular and organelle levels and may

  7. Radiofluorinated carbohydrates for positron emission tomography.

    PubMed

    Mun, Jiyoung

    2013-01-01

    2-Deoxy-2-[(18)F]fluoro-D-glucose (2-(18)FDG) has represented radiofluorinated carbohydrates as the most successful tracer for positron emission tomography (PET). 2-(18)FDG uptake depends on glucose metabolism, which is related to a disease progression. 2-(18)FDG has been widely used in oncology, neurology, cardiology, infectious diseases, and inflammation, to complement anatomical modalities such as CT and MRI. Followed by the success of 2-(18)FDG, various radiofluorinated carbohydrates have been evaluated as PET tracers, which include analogs of D-ribose, D-mannose, D-galactose, D-talose, D-fructose, D-allose, lactose, L-fucose, N-acetylneuraminic acid, and L-ascorbic acid. Among those radiofluorinated carbohydrates, several have implied potential for further development. 2-Deoxy-2-[(18)F]fluoro-D-galactose has been developed to assess liver function and diagnose hepatic carcinoma. 6-Deoxy-6-[(18)F]fluoro-D-fructose showed promising characteristics for diagnosis of breast cancer. Three radiofluorinated analogs of lactose have been designed as the substrates of the overexpressed hepatocarcinoma-intestine-pancreas/pancreatitis-associated protein in peritumoral pancreatic tissue for early diagnosis of pancreatic cancer. The metabolism of 6-[(18)F]fluoro-L-fucose suggested that it is a bioactive analog of L-fucose in the synthesis of glycoconjugate macromolecules. 6-Deoxy-6-[(18)F]fluoro-L-ascorbic acid was evaluated to assess antioxidant function of L-ascorbic acid in rodent models of transient global ischemia and glutathione deficiency.

  8. Asymptomatic Emphysematous Pyelonephritis - Positron Emission Tomography Computerized Tomography Aided Diagnostic and Therapeutic Elucidation

    PubMed Central

    Pathapati, Deepti; Shinkar, Pawan Gulabrao; kumar, Satya Awadhesh; Jha; Dattatreya, Palanki Satya; Chigurupati, Namrata; Chigurupati, Mohana Vamsy; Rao, Vatturi Venkata Satya Prabhakar

    2017-01-01

    The authors report an interesting coincidental unearthing by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) of a potentially serious medical condition of emphysematous pyelonephritis in a case of nasopharyngeal carcinoma. The management by conservative ureteric stenting and antibiotics was done with gratifying clinical outcome. PMID:28242985

  9. Fuzzy-rule-based image reconstruction for positron emission tomography

    NASA Astrophysics Data System (ADS)

    Mondal, Partha P.; Rajan, K.

    2005-09-01

    Positron emission tomography (PET) and single-photon emission computed tomography have revolutionized the field of medicine and biology. Penalized iterative algorithms based on maximum a posteriori (MAP) estimation eliminate noisy artifacts by utilizing available prior information in the reconstruction process but often result in a blurring effect. MAP-based algorithms fail to determine the density class in the reconstructed image and hence penalize the pixels irrespective of the density class. Reconstruction with better edge information is often difficult because prior knowledge is not taken into account. The recently introduced median-root-prior (MRP)-based algorithm preserves the edges, but a steplike streaking effect is observed in the reconstructed image, which is undesirable. A fuzzy approach is proposed for modeling the nature of interpixel interaction in order to build an artifact-free edge-preserving reconstruction. The proposed algorithm consists of two elementary steps: (1) edge detection, in which fuzzy-rule-based derivatives are used for the detection of edges in the nearest neighborhood window (which is equivalent to recognizing nearby density classes), and (2) fuzzy smoothing, in which penalization is performed only for those pixels for which no edge is detected in the nearest neighborhood. Both of these operations are carried out iteratively until the image converges. Analysis shows that the proposed fuzzy-rule-based reconstruction algorithm is capable of producing qualitatively better reconstructed images than those reconstructed by MAP and MRP algorithms. The reconstructed images are sharper, with small features being better resolved owing to the nature of the fuzzy potential function.

  10. Overview of positron emission tomography chemistry: clinical and technical considerations and combination with computed tomography.

    PubMed

    Koukourakis, G; Maravelis, G; Koukouraki, S; Padelakos, P; Kouloulias, V

    2009-01-01

    The concept of emission and transmission tomography was introduced by David Kuhl and Roy Edwards in the late 1950s. Their work later led to the design and construction of several tomographic instruments at the University of Pennsylvania. Tomographic imaging techniques were further developed by Michel Ter-Pogossian, Michael E. Phelps and others at the Washington University School of Medicine. Positron emission tomography (PET) is a nuclear medicine imaging technique which produces a 3-dimensional image or map of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (tracer), which is introduced into the body on a biologically active molecule. Images of tracer concentration in 3-dimensional space within the body are then reconstructed by computer analysis. In modern scanners, this reconstruction is often accomplished with the aid of a CT X-ray scan performed on the patient during the same session, in the same machine. If the biologically active molecule chosen for PET is 18F-fluorodeoxyglucose (FDG), an analogue of glucose, the concentrations of tracer imaged give tissue metabolic activity in terms of regional glucose uptake. Although use of this tracer results in the most common type of PET scan, other tracer molecules are used in PET to image the tissue concentration of many other types of molecules of interest. The main role of this article was to analyse the available types of radiopharmaceuticals used in PET-CT along with the principles of its clinical and technical considerations.

  11. 21 CFR 892.1200 - Emission computed tomography system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Emission computed tomography system. 892.1200 Section 892.1200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1200 Emission computed...

  12. Positron Emission Tomography: state of the art and future developments

    NASA Astrophysics Data System (ADS)

    Pizzichemi, M.

    2016-08-01

    Positron emission tomography (PET) plays a fundamental role in medical imaging, with a wide range of applications covering, among the others, oncology, neurology and cardiology. PET has undergone a steady technological evolution since its introduction in mid 20th century, from the development of 3D PET in the late 1980s, to the invention of PET/CT in the 1990s and more recently with the introduction of PET/MR scanners. The current research topics aiming to develop the next generation of PET scanners are summarized in this paper, focusing on the efforts to increase the sensitivity of the detectors, as long as improving their timing, spatial and energy resolutions, with the final goal of reducing the amount of radioactive dose received by the patients and the duration of the exams while improving at the same time the detectability of lesions.

  13. Quantitative single photon emission computed thallium-201 tomography for detection and localization of coronary artery disease: Optimization and prospective validation of a new technique

    SciTech Connect

    Maddahi, J.; Van Train, K.; Prigent, F.; Garcia, E.V.; Friedman, J.; Ostrzega, E.; Berman, D. )

    1989-12-01

    One hundred eight-three men underwent stress-redistribution thallium-201 myocardial perfusion tomography. After evaluation of various preprocessing filters in a phantom study, the Butterworth filter with a frequency cutoff of 0.2 cycles/pixel, order 5 (which provided optimal filter power) was used in the back projection algorithm of the patient studies. All short-axis and apical portions of vertical long-axis images were quantified by dividing each myocardial slice into 60 equal sectors and displaying the maximal count per sector as a linear profile. In a pilot group consisting of 20 normal men (less than 5% likelihood of coronary artery disease) and 25 men with coronary artery disease (greater than or equal to 50% coronary stenosis by angiography), profiles representing the lowest observed value below the mean normal profiles provided the best threshold for defining normal limits. Abnormal portions of the patient profiles were plotted on a two-dimensional polar map. The polar map was divided into 102 sectors, and sectors with a probability of greater than or equal to 80% for disease of each one of the three major coronary arteries were clustered to represent specific coronary artery territories. Receiver operating characteristic curve analysis for defect size showed that the optimal threshold for defining a definite perfusion defect was 12% for the left anterior descending and left circumflex and 8% for the right coronary artery territories. These criteria were prospectively applied to an additional 92 patients with angiographic coronary artery disease, 18 patients with normal coronary arteriograms and 28 patients with less than 5% likelihood of coronary disease. Sensitivity, specificity and normalcy rate for overall detection of coronary disease were 96%, 56% and 86%, respectively.

  14. Multimodal sentinel lymph node mapping with single-photon emission computed tomography (SPECT)/computed tomography (CT) and photoacoustic tomography.

    PubMed

    Akers, Walter J; Edwards, W Barry; Kim, Chulhong; Xu, Baogang; Erpelding, Todd N; Wang, Lihong V; Achilefu, Samuel

    2012-03-01

    The identification of cancer cells in the lymph nodes surrounding a tumor is important in establishing a prognosis. Optical detection techniques such as fluorescence and photoacoustic tomography (PAT) have been reported in preclinical studies for noninvasive sentinel lymph node (SLN) mapping. A method for validation of these techniques is needed for clinical trials. We report the use of a multimodal optical-radionuclear contrast agent as a validation tool for PAT in a preclinical model. Methylene blue (MB) was radiolabeled with (125)I for multimodal SLN mapping and used in conjunction with MB to assess the feasibility of multimodal SLN mapping in a rat model by PAT and single-photon emission computed tomography (SPECT). MB provided sufficient contrast for identifying SLNs noninvasively with a PAT system adapted from a clinical ultrasound imaging system. The signal location was corroborated by SPECT using (125)I labeled MB. The translation of PAT into the clinic can be facilitated by a direct comparison with established imaging methods using a clinically relevant dual SPECT and photoacoustic imaging agent. The new high-resolution PAT is a promising technology for the sensitive and accurate SLN detection in cancer patients. Copyright © 2012 Mosby, Inc. All rights reserved.

  15. Characterization of nontransmural myocardial infarction by positron-emission tomography

    SciTech Connect

    Geltman, E.M.; Biello, D.; Welch, M.J.; Ter-Pogossian, M.M.; Roberts, R.; Sobel, B.E.

    1982-04-01

    The present study was performed to determine whether positron emission tomography (PET) performed after i.v. 11C-palmitate permits detection and characterization of nontransmural myocardial infarction. PET was performed after the i.v. injection of 11C-palmitate in 10 normal subjects, 24 patients with initial nontransmural myocardial infarction (defined electrocardiographically), and 22 patients with transmural infarction. Depressed accumulation of 11C-palmitate was detected with sagittal, coronal and transverse reconstructions, and quantified based on 14 contiguous transaxial reconstructions. Defects with homogeneously intense depression of accumulation of tracer were detected in all 22 patients with transmural infarction (100%). Abnormalities of the distribution of 11C-palmitate in the myocardium were detected in 23 patients with nontransmural infarction (96%). Thallium scintigrams were abnormal in only 11 of 18 patients with nontransmural infarction (61%). Tomographically estimated infarct size was greater among patients with transmural infarction (50.4 +/- 7.8 PET-g-Eq/m2 (+/- SEM SEM)) compared with those with nontransmural infarction (19 +/- 4 PET-g-Eq, p less than 0.01). Residual accumulation of 11C-palmitate within regions of infarction was more intensely depressed among patients with transmural compared to nontransmural infarction (33 +/- 1 vs 39 +/- 1% maximal myocardial radioactivity, p less than 0.01). Thus, PET and metabolic imaging with 11C-palmitate is a sensitive means of detecting, quantifying and characterizing nontransmural and transmural myocardial infarction.

  16. An online emission spectral tomography system with digital signal processor.

    PubMed

    Wan, Xiong; Xiong, Wenlin; Zhang, Zhimin; Chang, Fangfei

    2009-03-30

    Emission spectral tomography (EST) has been adopted to test the three-dimensional distribution parameters of fluid fields, such as burning gas, flame and plasma etc. In most cases, emission spectral data received by the video cameras are enormous so that the emission spectral tomography calculation is often time-consuming. Hence, accelerating calculation becomes the chief factor that one must consider for the practical application of EST. To solve the problem, a hardware implementation method was proposed in this paper, which adopted a digital signal processor (DSP) DM642 in an emission spectral tomography test system. The EST algorithm was fulfilled in the DSP, then calculation results were transmitted to the main computer via the user datagram protocol. Compared with purely VC++ software implementations, this new approach can decrease the calculation time significantly.

  17. Orbital positron emission tomography/computed tomography (PET/CT) imaging findings in graves ophthalmopathy

    PubMed Central

    2013-01-01

    Background We aimed to describe orbital positron emission tomography/computed tomography (PET/CT) imaging findings, both structural and metabolic, in different clinical stages of Graves ophthalmopathy (GO). This prospective, observational, cross-sectional study examined 32 eyes of 16 patients with GO. Methods Patients were assessed with a complete ophthalmological evaluation and assigned a VISA classification for GO. All patients underwent serum thyroid hormone measurement, antibody profile, and 18-fluorodeoxyglucose positron emission tomography/computed tomography (18-FDG PET/CT) of the orbits. The 18-FDG uptake on PET images was expressed in terms of maximum standard uptake value (SUVmax). CT images were analyzed, and orbital structures were measured in millimeters. Vision, inflammation, strabismus, and overall appearance were assessed according to the VISA classification system, thyroid hormone levels, antibody values, 18-FDG uptake, and thickness of orbital structures. Results Altogether, 32 eyes of 16 patients (10 women, 6 men; mean age 44.31 ± 13 years, range 20–71 years) were included. Three patients were hypothyroid, seven were euthyroid, and six were hyperthyroid. CT measurements of extraocular muscle diameter were elevated (P < 0.05), and muscle 18-FDG uptake values were increased. Eyes with a clinical VISA inflammation score of ≤ 4 had an average extraocular muscle SUVmax of 3.09, and those with a score of ≥ 5 had an average SUVmax of 3.92 (P = 0.09), showing no clear correlation between clinically observed inflammation and 18-FDG uptake. 18-FDG uptake values also did not show a correlation with extraocular muscle diameter as measured by CT (R2 = 0.0755, P > 0.05). Conclusions We demonstrated a lack of correlation between 18-FDG extraocular muscle uptake and either clinical inflammation score or muscle diameter. Although 18-FDG uptake has been used as an inflammation marker in other pathologies, inflammation in GO may

  18. Role of positron emission tomography in urological oncology.

    PubMed

    Rioja, Jorge; Rodríguez-Fraile, Macarena; Lima-Favaretto, Ricardo; Rincón-Mayans, Anibal; Peñuelas-Sánchez, Iván; Zudaire-Bergera, Juan Javier; Parra, Raul O

    2010-12-01

    • Positron emission tomography (PET) is a diagnostic tool using radiotracers to show changes in metabolic activities in tissues. We analysed the role of PET and PET/computed tomography (CT) in the diagnosis, staging, and follow-up of urological tumours. • A critical, non-structured review of the literature of the role of PET and PET/CT in urological oncology was conducted. • PET and PET/CT can play a role in the management of urological malignancies. For prostate cancer, the advances in radiotracers seems promising, with novel radiotracers yielding better diagnostic and staging results than 18F-fluorodeoxyglucose (18F-FDG). In kidney cancer, PET and PET/CT allow a proper diagnosis before the pathological examination of the surgical specimen. For testis cancer, PET and PET/CT have been shown to be useful in the management of seminoma tumours. In bladder cancer, these scans allow a better initial diagnosis for invasive cancer, while detecting occult metastases. • PET and its combined modality PET/CT have shown their potential in the diagnosis of urological malignancies. However, further studies are needed to establish the role of PET in the management of these diseases. Future applications of PET may involve fusion techniques such as magnetic resonance imaging with PET.

  19. Positron emission tomography in patients with clinically diagnosed Alzheimer's disease.

    PubMed Central

    McGeer, P L; Kamo, H; Harrop, R; Li, D K; Tuokko, H; McGeer, E G; Adam, M J; Ammann, W; Beattie, B L; Calne, D B

    1986-01-01

    Fourteen patients who had clinically diagnosed Alzheimer's disease with mild to severe dementia (mean age 69.1 years) were evaluated by calculation of local cerebral metabolic rate for glucose (LCMR-gl) based on uptake of 18F-2-fluoro-2-deoxyglucose (FDG) detected with positron emission tomography (PET). PET scanning showed that the patients had significantly lower LCMR-gl values than 11 age-matched neurologically normal volunteers (mean age 66.3 years). The differences were most marked in the temporal cortex, followed by the frontal, parietal and occipital cortex. In each case the LCMR-gl value was below the lowest control value in at least one cortical area and usually in several; the reduction in LCMR-gl and the number of regions involved in the patients increased with the severity of the dementia. Deficits noted in neuropsychologic testing generally correlated with those predicted from loss of regional cortical metabolism. The patients with Alzheimer's disease were also examined with magnetic resonance imaging, computed tomography or both; the degree of atrophy found showed only a poor correlation with the neuropsychologic deficit. Significant atrophy was also noted in some of the controls. A detailed analysis of LCMR-gl values in selected cerebral regions of various sizes refuted the hypothesis that the reduction in cortical glucose metabolism in Alzheimer's disease is due to the filling by metabolically inert cerebrospinal fluid of space created by tissue atrophy. Images Fig. 2 Fig. 3 Fig. 4 Fig. 7 Fig. 8 Fig. 9 PMID:3512063

  20. Monte Carlo Simulation Of Emission Tomography And Other Medical Imaging Techniques.

    PubMed

    Harrison, Robert L

    2010-01-05

    An introduction to Monte Carlo simulation of emission tomography. This paper reviews the history and principles of Monte Carlo simulation, then applies these principles to emission tomography using the public domain simulation package SimSET (a Simulation System for Emission Tomography) as an example. Finally, the paper discusses how the methods are modified for X-ray computed tomography and radiotherapy simulations.

  1. C-Arm Computed Tomography Compared With Positron Emission Tomography/Computed Tomography for Treatment Planning Before Radioembolization

    SciTech Connect

    Becker, Christoph Waggershauser, Tobias; Tiling, Reinhold; Weckbach, Sabine; Johnson, Thorsten; Meissner, Oliver; Klingenbeck-Regn, Klaus; Reiser, Maximilian; Hoffmann, Ralf Thorsten

    2011-06-15

    The purpose of this study was to determine whether rotational C-arm computed tomography (CT) allows visualization of liver metastases and adds relevant information for radioembolization (RE) treatment planning. Technetium angiography, together with C-arm CT, was performed in 47 patients to determine the feasibility for RE. C-arm CT images were compared with positron emission tomography (PET)/CT images for the detection of liver tumors. The images were also rated according one of the following three categories: (1) images that provide no additional information compared with DSA alone; (2) images that do provide additional information compared with DSA; and (2) images that had an impact on eligibility determination for and planning of the RE procedure. In all patients, 283 FDG-positive liver lesions were detected by PET. In venous contrast-phase CT, 221 (78.1%) and 15 (5.3%) of these lesions were either hypodense or hyperdense, respectively. In C-arm CT, 103 (36.4%) liver lesions were not detectable because they were outside of either the field of view or the contrast-enhanced liver segment. Another 25 (8.8%) and 98 (34.6%) of the liver lesions were either hyperdense or presented primarily as hypodense lesions with a rim enhancement, respectively. With PET/CT as the standard of reference, venous CT and C-arm CT failed to detect 47 (16.6%) and 57 (20.1%) of all liver lesions, respectively. For RE planning, C-arm CT provided no further information, provide some additional information, or had an impact on the procedure in 20 (42.5%), 15 (31.9%) and 12 (25.6%) of patients, respectively. We conclude that C-arm CT may add decisive information in patients scheduled for RE.

  2. Principles and clinical applications of positron emission tomography.

    PubMed

    Gardner, S F; Green, J A; Bednarczyk, E M; Farnett, L; Miraldi, F

    1992-06-01

    The basics of positron emission tomography (PET) are presented, including the physics, instrumentation, and radiopharmaceuticals involved; the clinical and research applications; and the cost. In PET, organic molecules labeled with positron-emitting radionuclides are injected or inhaled, and the high-energy photons produced by annihilation events are detected by paired, integrated crystal detectors. A computer uses the lines of origin of these photons to reconstruct a three-dimensional map of a functioning organ system. The positron-emitting radionuclides most often used are carbon 11, oxygen 15, nitrogen 13, fluorine 18, and rubidium 82. PET imaging centers usually consist of a cyclotron facility, a radiochemistry facility, a PET scanner, and computers for image reconstruction. Radiopharmaceuticals used in PET may be divided into blood flow-imaging agents, metabolic imaging agents, and drug receptor-imaging agents. Although PET is still primarily a research tool, it has shown diagnostic potential in neurology, cardiology, and oncology. It has also shown promise as a tool for pharmacologic assessment, as in studies of the effects of the fluorinated quinolones on cerebral blood flow and glucose metabolism. PET may become important in drug development because it yields specific information relatively noninvasively. A single study carries an average break-even price tag of $1500-$2000; rigorous cost-benefit analyses should be conducted before society is asked to subsidize such costs. Positron emission tomography is a frontier technology for which valuable clinical applications are being discovered. Pharmacists can contribute enormously to PET applications and at the same time establish a unique subspecialty for the profession.

  3. Diagnosis of dementia with single photon emission computed tomography

    SciTech Connect

    Jagust, W.J.; Budinger, T.F.; Reed, B.R.

    1987-03-01

    Single photon emission computed tomography is a practical modality for the study of physiologic cerebral activity in vivo. We utilized single photon emission computed tomography and N-isopropyl-p-iodoamphetamine iodine 123 to evaluate regional cerebral blood flow in nine patients with Alzheimer's disease (AD), five healthy elderly control subjects, and two patients with multi-infarct dementia. We found that all subjects with AD demonstrated flow deficits in temporoparietal cortex bilaterally, and that the ratio of activity in bilateral temporoparietal cortex to activity in the whole slice allowed the differentiation of all patients with AD from both the controls and from the patients with multi-infarct dementia. Furthermore, this ratio showed a strong correlation with disease severity in the AD group. Single photon emission computed tomography appears to be useful in the differential diagnosis of dementia and reflects clinical features of the disease.

  4. Novel targets for positron emission tomography (PET) radiopharmaceutical tracers for visualization of neuroinflammation

    NASA Astrophysics Data System (ADS)

    Shchepetkin, I.; Shvedova, M.; Anfinogenova, Y.; Litvak, M.; Atochin, D.

    2017-08-01

    Non-invasive molecular imaging techniques can enhance diagnosis of neurological diseases to achieve their successful treatment. Positron emission tomography (PET) imaging can identify activated microglia and provide detailed functional information based on molecular biology. This imaging modality is based on detection of isotope labeled tracers, which emit positrons. The review summarizes the developments of various radiolabeled ligands for PET imaging of neuroinflammation.

  5. [Positron-emission tomography/computed tomography: artifacts and pitfalls in cancer patients].

    PubMed

    Gorospe Sarasúa, L; Echeveste Aizpurúa, J; Raman, S

    2006-01-01

    Diagnostic accuracy and correct initial staging (or restaging) are fundamental in the management of oncological patients and can directly influence therapeutic decisions. The combination of positron-emission tomography (PET) and computed tomography (CT) in a single scanner (PET/TC) represents an important achievement in the fields of oncology, nuclear medicine, and radiology. These scanners allow morphologic images (obtained by CT) to be fused and correlated with metabolic images (obtained by PET) to a high degree of accuracy. In addition to an understanding of the physiopathology of cancer and the behavior of the different types of neoplasms, the correct interpretation of PET/CT images requires in-depth knowledge of the physiological distribution of the F-18 fluorodeoxyglucose molecule (FDG, currently the most widely used marker in oncology), of the frequent physiological variations in its distribution, and of the possible causes of non-malignant pathological FDG uptake. Furthermore, the use of CT data to correct attenuation and reconstruct PET images in PET/CT scanners can generate some characteristic artifacts specific to this new diagnostic tool, and these can lead to misinterpretation with potential therapeutic implications. This article reviews and illustrates some of the most common artifacts and pitfalls that can appear in PET/CT studies. The detection and correct interpretation of these findings are essential for the appropriate management of oncologic patients.

  6. Positron emission tomography-computed tomography in the management of lung cancer: An update

    PubMed Central

    Sharma, Punit; Singh, Harmandeep; Basu, Sandip; Kumar, Rakesh

    2013-01-01

    This communication presents an update on the current role of positron emission tomography-computed tomography (PET-CT) in the various clinical decision-making steps in lung carcinoma. The modality has been reported to be useful in characterizing solitary pulmonary nodules, improving lung cancer staging, especially for the detection of nodal and metastatic site involvement, guiding therapy, monitoring treatment response, and predicting outcome in non-small cell lung carcinoma (NSCLC). Its role has been more extensively evaluated in NSCLC than small cell lung carcinoma (SCLC). Limitations in FDG PET-CT are encountered in cases of tumor histotypes characterized by low glucose uptake (mucinous forms, bronchioalveolar carcinoma, neuroendocrine tumors), in the assessment of brain metastases (high physiologic 18F-FDG uptake in the brain) and in cases presenting with associated inflammation. The future potentials of newer PET tracers beyond FDG are enumerated. An evolving area is PET-guided assessment of targeted therapy (e.g., EGFR and EGFR tyrosine kinase overexpression) in tumors which have significant potential for drug development. PMID:24455612

  7. Positron emission tomography/computer tomography in gastrointestinal malignancies: current potential and challenges.

    PubMed

    Tind, Sofie; Vestergaard, Sys; Farahani, Ziba A; Hess, Søren

    2017-10-01

    The use of 18F-Fluoro-D-deoxy-glucose -positron emission tomography/computed tomography (FDG-PET/CT) in gastrointestinal (GI)-malignancies may not be as straightforward as in many other cancers, but the potential is clearly there in select clinical settings. The challenges include the relative non-specificity of FDG, the variable degrees of physiologic FDG-uptake, and the heterogeneous FDG-uptake in different cell types within the GI-domain, which all together hamper the use in primary diagnostics. In general, the literature is older, heterogeneous, and based on stand-alone PET, which is now largely considered obsolete. There is emerging evidence for use of hybrid PET/CT, but the literature is still relatively sparse. The main indications are preoperative staging of distant metastases, not only in limited disease but also before curative treatment of limited metastatic disease. Controversies remain concerning liver metastases but improved technology boast well for the future role of FDG-PET/CT not least concerning equivocal findings on conventional imaging. In our opinion, an important upcoming indication is early response assessment, perhaps mostly in the neoadjuvant settings of upper GI-malignancies, but standardization of response assessment criteria is lacking before a more widespread implementation is feasible. Finally, there seems to be a significant role in recurrence detection, especially in CRC.

  8. Ultrasonic guided wave tomography for ice detection.

    PubMed

    Zhao, Xiang; Rose, Joseph L

    2016-04-01

    Of great concern for many structures, particularly critical sections of rotary and fixed wing aircrafts, is the ability to detect ice either on grounded or in-flight vehicles. As a consequence, some work is reported here that could be useful for a variety of different industries where ice formation is an important problem. This paper presents experimental validations of a probability-based reconstruction algorithm (PRA) on ice detection of plate-like structures. The ice detection tests are performed for three different specimens: a single layer aluminum plate with a circular ice sensing array, a titanium plate with a sparse rectangular ice sensing array, and a carbon-fiber-reinforced titanium plate with an embedded ice sensing array mounted on a carbon fiber back plate. Cases from the simple to the more challenging exemplify that special modes can be used to differentiate ice from water, a sparse rectangular array could also be used for ice detection, and an ice sensing array could be further used to detect the ice on the sensor free side, a very useful application of ice sensing for aircraft wings, for example. Ice detection images for the respective cases are reconstructed to investigate the feasibility of ice sensing with ultrasonic guided wave tomography technology. The results show that the PRA based ultrasonic guided wave tomography method successfully detected and showed ice spots correctly for all three cases. This corroborates the fact that ultrasonic guided wave imaging technology could be a potential useful ice sensing tool in plate-like structures.

  9. Positron emission tomography in the evaluation of subdural hematomas

    SciTech Connect

    Ericson, K.; Bergstroem, M.; Eriksson, L.

    1980-12-01

    Fifteen patients with 21 subdural effusions were investigated both with transmission computer assisted tomography (CAT) and positron emission tomography (PET). The tracer in the emission studies was /sup 68/Ga-EDTA. Twelve lesions were visualized both with CAT and PET. Five lesions that were negative or doubtful on CAT were visualized with PET, whereas four lesions negative or doubtful on PET were demonstrated by CAT. The two methods complement each other due to the fact that they are based on different mechanisms: CAT mainly on attenuation of the fluid collection. PET on isotope accumulation, particularly in the hematoma membranes.

  10. Magnetosensory function in rats: localization using positron emission tomography.

    PubMed

    Frilot, Clifton; Carrubba, Simona; Marino, Andrew A

    2009-05-01

    The aim of this study was to show that low-strength electromagnetic fields (EMFs) produced evoked potentials in rats and to localize the activated region in the brain. In response to a 2.5-G, 60-Hz stimulus, onset- and offset-evoked potentials were detected (P < 0.05 in each of the 10 animals studied); the evoked potentials had the same magnitude, latency, and nonlinear relationship to the field seen in previous studies on rabbits and human subjects. The neuroanatomical region of activation associated with the electrophysiological effect was identified by positron emission tomography using fluorodeoxyglucose. Paired emission scans (the same animal with and without field treatment) from 10 additional rats were differenced and averaged to produce a t-statistic image using the pooled variance; the t value of each voxel was compared with a calculated critical t value to identify the activated voxels (P < 0.05). A brain volume of 13 mm(3) (15 voxels) located in the posterior, central cerebellum was found to have been activated by exposure to the field. Taken together, the results indicated that magnetosensory evoked potentials in the rats were associated with increased glucose utilization in the cerebellum, thereby supporting earlier evidence that EMF transduction occurred in the brain.

  11. Single Photon Emission Local Tomography (SPELT)

    SciTech Connect

    Zeng, G.L.; Gullberg, G.T.

    1996-12-31

    Local tomography uses truncated projection data to reconstruct a region of interest, and is important in medical imaging and industrial non-destructive evaluation using micro X-ray CT. The popular filtered backprojection (FBP) algorithm does not reconstruct a reliable image, which varies with the degree and location of truncation due to its global convolution kernel. A typical local tomography method uses a second derivative local operator to replace the global convolution kernel in the filtered backprojection algorithm (LFBP). By using a local filter, the reconstructed region depends only on the local projections. The singularities (edges) are preserved, but the exact image value cannot be recovered. This paper, using the data consistency conditions, developed a pre-processing technique that uses the FBP algorithm, which outperforms direct FBP and LFBP.

  12. Positron emission tomography-computed tomography coregistration for diagnosis and intraoperative localization in recurrent nelson syndrome.

    PubMed

    Hintz, Eric B; Tomlin, Jeffery M; Chengazi, Vaseem; Vates, G Edward

    2013-06-01

    Recurrent pituitary disease presents unique challenges, including in some cases difficulty localizing a tumor radiographically. Here, we present the case of a patient with recurrent Nelson syndrome whose radiographic work-up was complicated by a significant parasellar metallic artifact. Positron emission tomography ultimately localized the lesion, and coregistration with computed tomography allowed for accurate intraoperative navigation. Additionally, we review a range of imaging techniques available in the evaluation of pituitary disease.

  13. Pigmented villonodular synovitis mimics metastases on fluorine 18 fluorodeoxyglucose position emission tomography-computed tomography.

    PubMed

    Elumogo, Comfort O; Kochenderfer, James N; Civelek, A Cahid; Bluemke, David A

    2016-04-01

    Pigmented villonodular synovitis (PVNS) is a benign joint disease best characterized on magnetic resonance imaging (MRI). The role of fluorine 18 fluorodeoxyglucose ((18)F-FDG) position emission tomography-computed tomography (PET-CT) in the diagnosis or characterization remains unclear. PVNS displays as a focal FDG avid lesion, which can masquerade as a metastatic lesion, on PET-CET. We present a case of PVNS found on surveillance imaging of a lymphoma patient.

  14. Pigmented villonodular synovitis mimics metastases on fluorine 18 fluorodeoxyglucose position emission tomography-computed tomography

    PubMed Central

    Elumogo, Comfort O.; Kochenderfer, James N.; Civelek, A. Cahid

    2016-01-01

    Pigmented villonodular synovitis (PVNS) is a benign joint disease best characterized on magnetic resonance imaging (MRI). The role of fluorine 18 fluorodeoxyglucose (18F-FDG) position emission tomography-computed tomography (PET-CT) in the diagnosis or characterization remains unclear. PVNS displays as a focal FDG avid lesion, which can masquerade as a metastatic lesion, on PET-CET. We present a case of PVNS found on surveillance imaging of a lymphoma patient. PMID:27190776

  15. Endocrine radionuclide scintigraphy with fusion single photon emission computed tomography/computed tomography

    PubMed Central

    Wong, Ka-Kit; Gandhi, Arpit; Viglianti, Benjamin L; Fig, Lorraine M; Rubello, Domenico; Gross, Milton D

    2016-01-01

    AIM: To review the benefits of single photon emission computed tomography (SPECT)/computed tomography (CT) hybrid imaging for diagnosis of various endocrine disorders. METHODS: We performed MEDLINE and PubMed searches using the terms: “SPECT/CT”; “functional anatomic mapping”; “transmission emission tomography”; “parathyroid adenoma”; “thyroid cancer”; “neuroendocrine tumor”; “adrenal”; “pheochromocytoma”; “paraganglioma”; in order to identify relevant articles published in English during the years 2003 to 2015. Reference lists from the articles were reviewed to identify additional pertinent articles. Retrieved manuscripts (case reports, reviews, meta-analyses and abstracts) concerning the application of SPECT/CT to endocrine imaging were analyzed to provide a descriptive synthesis of the utility of this technology. RESULTS: The emergence of hybrid SPECT/CT camera technology now allows simultaneous acquisition of combined multi-modality imaging, with seamless fusion of three-dimensional volume datasets. The usefulness of combining functional information to depict the bio-distribution of radiotracers that map cellular processes of the endocrine system and tumors of endocrine origin, with anatomy derived from CT, has improved the diagnostic capability of scintigraphy for a range of disorders of endocrine gland function. The literature describes benefits of SPECT/CT for 99mTc-sestamibi parathyroid scintigraphy and 99mTc-pertechnetate thyroid scintigraphy, 123I- or 131I-radioiodine for staging of differentiated thyroid carcinoma, 111In- and 99mTc- labeled somatostatin receptor analogues for detection of neuroendocrine tumors, 131I-norcholesterol (NP-59) scans for assessment of adrenal cortical hyperfunction, and 123I- or 131I-metaiodobenzylguanidine imaging for evaluation of pheochromocytoma and paraganglioma. CONCLUSION: SPECT/CT exploits the synergism between the functional information from radiopharmaceutical imaging and anatomy

  16. Assessment of the relationship between stenosis severity and distribution of coronary artery stenoses on multislice computed tomographic angiography and myocardial ischemia detected by single photon emission computed tomography

    PubMed Central

    Tamarappoo, Balaji K.; Gutstein, Ariel; Cheng, Victor Y.; Nakazato, Ryo; Gransar, Heidi; Dey, Damini; Thomson, Louise E. J.; Hayes, Sean W.; Friedman, John D.; Germano, Guido; Slomka, Piotr J.

    2010-01-01

    Background The relationship between luminal stenosis measured by coronary CT angiography (CCTA) and severity of stress-induced ischemia seen on single photon emission computed tomographic myocardial perfusion imaging (SPECT-MPI) is not clearly defined. We sought to evaluate the relationship between stenosis severity assessed by CCTA and ischemia on SPECT-MPI. Methods and Results ECG-gated CCTA (64 slice dual source CT) and SPECT-MPI were performed within 6 months in 292 patients (ages 26-91, 73% male) with no prior history of coronary artery disease. Maximal coronary luminal narrowing, graded as 0, ≥25%, 50%, 70%, or 90% visual diameter reduction, was consensually assessed by two expert readers. Perfusion defect on SPECT-MPI was assessed by computer-assisted visual interpretation by an expert reader using the standard 17 segment, 5 point-scoring model (stress perfusion defect of ≥5% = abnormal). By SPECT-MPI, abnormal perfusion was seen in 46/292 patients. With increasing stenosis severity, positive predictive value (PPV) increased (42%, 51%, and 74%, P = .01) and negative predictive value was relatively unchanged (97%, 95%, and 91%) in detecting perfusion abnormalities on SPECT-MPI. In a receiver operator curve analysis, stenosis of 50% and 70% were equally effective in differentiating between the presence and absence of ischemia. In a multivariate analysis that included stenosis severity, multivessel disease, plaque composition, and presence of serial stenoses in a coronary artery, the strongest predictors of ischemia were stenosis of 50-89%, odds ratio (OR) 7.31, P = .001, stenosis ≥90%, OR 34.05, P = .0001, and serial stenosis ≥50% OR of 3.55, P = .006. Conclusions The PPV of CCTA for ischemia by SPECT-MPI rises as stenosis severity increases. Luminal stenosis ≥90% on CCTA strongly predicts ischemia, while <50% stenosis strongly predicts the absence of ischemia. Serial stenosis of ≥50% in a vessel may offer incremental value in addition

  17. Addiction Studies with Positron Emission Tomography

    ScienceCinema

    Joanna Fowler

    2016-07-12

    Brookhaven scientist Joanna Fowler describes Positron Emission Technology (PET) research at BNL which for the past 30 years has focused in the integration of basic research in radiotracer chemistry with the tools of neuroscience to develop new scientific

  18. Addiction Studies with Positron Emission Tomography

    SciTech Connect

    Joanna Fowler

    2008-10-13

    Brookhaven scientist Joanna Fowler describes Positron Emission Technology (PET) research at BNL which for the past 30 years has focused in the integration of basic research in radiotracer chemistry with the tools of neuroscience to develop new scientific

  19. The Positron Emission Tomography Tracer 3’-Deoxy-3’-[18F]Fluorothymidine ([18F]FLT) Is Not Suitable to Detect Tissue Proliferation Induced by Systemic Yersinia enterocolitica Infection in Mice

    PubMed Central

    Rolle, Anna-Maria; Warnke, Philipp; Kohlhofer, Ursula; Quintanilla-Martinez, Leticia; Reischl, Gerald; Autenrieth, Ingo B.; Pichler, Bernd J.; Autenrieth, Stella E.

    2016-01-01

    Most frequently, gram-negative bacterial infections in humans are caused by Enterobacteriaceae and remain a major challenge in medical diagnostics. We non-invasively imaged moderate and severe systemic Yersinia enterocolitica infections in mice using the positron emission tomography (PET) tracer 3’-deoxy-3’-[18F]fluorothymidine ([18F]FLT), which is a marker of proliferation, and compared the in vivo results to the ex vivo biodistributions, bacterial loads, and histologies of the corresponding organs. Y. enterocolitica infection is detectable with histology using H&E staining and immunohistochemistry for Ki 67. [18F]FLT revealed only background uptake in the spleen, which is the main manifestation site of systemic Y. enterocolitica-infected mice. The uptake was independent of the infection dose. Antibody-based thymidine kinase 1 (Tk-1) staining confirmed the negative [18F]FLT-PET data. Histological alterations of spleen tissue, observed via Ki 67-antibody-based staining, can not be detected by [18F]FLT-PET in this model. Thus, the proliferation marker [18F]FLT is not a suitable tracer for the diagnosis of systemic Y. enterocolitica infection in the C57BL/6 animal model of yersiniosis. PMID:27701464

  20. Role of positron emission tomography/computed tomography in breast cancer.

    PubMed

    Bourgeois, Austin C; Warren, Lance A; Chang, Ted T; Embry, Scott; Hudson, Kathleen; Bradley, Yong C

    2013-09-01

    Although positron emission tomography (PET) imaging may not be used in the diagnosis of breast cancer, the use of PET/computed tomography is imperative in all aspects of breast cancer staging, treatment, and follow-up. PET will continue to be relevant in personalized medicine because accurate tumor status will be even more critical during and after the transition from a generic metabolic agent to receptor imaging. Positron emission mammography is an imaging proposition that may have benefits in lower doses, but its use is limited without new radiopharmaceuticals. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. [Methods and clinical applications of positron emission tomography in endocrinology].

    PubMed

    De Landsheere, C; Lamotte, D

    1990-01-01

    Positron emission tomography (PET) allows to detect in coincidence photons issued from annihilation between positrons and electrons nearby situated. Tomographic detection (plane by plane) and tomographic reconstruction will lead to the quantitation of radioactive distribution per voxel, in the organ of interest. Recent tomographs can acquire simultaneously several transaxial slices, with a high sensitivity and a spatial resolution of 3-5 mm. Commonly used positron emitters have a short half-life: 2, 10, 20 and 110 min for 150, 13N, 11C and 18F, respectively. The use of these isotopes requires on line production of radionuclides and synthesis of selected molecules. In endocrinology, PET allows among others to study noninvasively the receptor density of hormone-dependent neoplasms such as breast, uterus, prostate tumors and prolactinomas. These last tumors represent a particular entity because of several combined characteristics: high turnover rate of amino acids, high density of dopaminergic receptors and response to bromocriptine (analogue of dopamine inhibiting the secretion of prolactin) in relation to the level of receptors. Because PET permits to evaluate the density of dopaminergic receptors and the metabolism of amino acids, theoretical response of the prolactinoma to bromocriptine can be predicted, the achieved therapeutic efficacy can be estimated and the long-term follow up of tumor growth can be assessed. This example illustrates the clinical value of PET in endocrinology.

  2. MR imaging and positron emission tomography of cortical heterotopia

    SciTech Connect

    Bairamian, D.; Di Chiro, G.; Theodore, W.H.; Holmes, M.D.; Dorwart, R.H.; Larson, S.M.

    1985-11-01

    Heterotopia of the gray matter is a developmental malformation in which ectopic cortex is found in the white matter of the brain. A case of a 33-year-old man with cortical heterotopia who had a lifelong history of seizures and psychomotor retardation is reported, including the results of cerebral CT, magnetic resonance imaging, and positron emission tomography using YF-2-deoxyglucose.

  3. Positron Emission Tomography: Human Brain Function and Biochemistry.

    ERIC Educational Resources Information Center

    Phelps, Michael E.; Mazziotta, John C.

    1985-01-01

    Describes the method, present status, and application of positron emission tomography (PET), an analytical imaging technique for "in vivo" measurements of the anatomical distribution and rates of specific biochemical reactions. Measurements and image dynamic biochemistry link basic and clinical neurosciences with clinical findings…

  4. Positron Emission Tomography: Human Brain Function and Biochemistry.

    ERIC Educational Resources Information Center

    Phelps, Michael E.; Mazziotta, John C.

    1985-01-01

    Describes the method, present status, and application of positron emission tomography (PET), an analytical imaging technique for "in vivo" measurements of the anatomical distribution and rates of specific biochemical reactions. Measurements and image dynamic biochemistry link basic and clinical neurosciences with clinical findings…

  5. Comparison of sulfur hexafluoride microbubble (SonoVue)-enhanced myocardial contrast echocardiography with gated single-photon emission computed tomography for detection of significant coronary artery disease: a large European multicenter study.

    PubMed

    Senior, Roxy; Moreo, Antonella; Gaibazzi, Nicola; Agati, Luciano; Tiemann, Klaus; Shivalkar, Bharati; von Bardeleben, Stephan; Galiuto, Leonarda; Lardoux, Hervé; Trocino, Giuseppe; Carrió, Ignasi; Le Guludec, Dominique; Sambuceti, Gianmario; Becher, Harald; Colonna, Paolo; Ten Cate, Folkert; Bramucci, Ezio; Cohen, Ariel; Bezante, Gianpaolo; Aggeli, Costantina; Kasprzak, Jaroslaw D

    2013-10-08

    The purpose of this study was to compare sulfur hexafluoride microbubble (SonoVue)-enhanced myocardial contrast echocardiography (MCE) with single-photon emission computed tomography (SPECT) relative to coronary angiography (CA) for assessment of coronary artery disease (CAD). Small-scale studies have shown that myocardial perfusion assessed by SonoVue-enhanced MCE is a viable alternative to SPECT for CAD assessment. However, large multicenter studies are lacking. Patients referred for myocardial ischemia testing at 34 centers underwent rest/vasodilator SonoVue-enhanced flash-replenishment MCE, standard (99m)Tc-labeled electrocardiography-gated SPECT, and quantitative CA within 1 month. Myocardial ischemia assessments by 3 independent, blinded readers for MCE and 3 readers for SPECT were collapsed into 1 diagnosis per patient per technique and were compared to CA (reference standard) read by 1 independent blinded reader. Of 628 enrolled patients who received SonoVue (71% males; mean age: 64 years; >1 cardiovascular [CV] risk factor in 99% of patients) 516 patients underwent all 3 examinations, of whom 161 (31.2%) had ≥70% stenosis (131 had single-vessel disease [SVD]; 30 had multivessel disease), and 310 (60.1%) had ≥50% stenosis. Higher sensitivity was obtained with MCE than with SPECT (75.2% vs. 49.1%, respectively; p < 0.0001), although specificity was lower (52.4% vs. 80.6%, respectively; p < 0.0001) for ≥70% stenosis. Similar findings were obtained for patients with ≥50% stenosis. Sensitivity levels for detection of SVD and proximal disease for ≥70% stenosis were higher for MCE (72.5% vs. 42.7%, respectively; p < 0.0001; 80% vs. 58%, respectively; p = 0.005, respectively). SonoVue-enhanced MCE demonstrated superior sensitivity but lower specificity for detection of CAD compared to SPECT in a population with a high incidence of CV risk factors and intermediate-high prevalence of CAD. (A phase III study to compare SonoVue® enhanced myocardial

  6. Accuracy of 18F fluorodeoxyglucose positron emission tomography/computed tomography in staging of pediatric sarcomas.

    PubMed

    Tateishi, Ukihide; Hosono, Ako; Makimoto, Atsushi; Sakurada, Aine; Terauchi, Takashi; Arai, Yasuaki; Imai, Yutaka; Kim, Euishin Edmund

    2007-09-01

    The present study was conducted to clarify the diagnostic accuracy of 18F-fluoro-2-deoxy-D-glucose (18FDG) positron emission tomography (PET)/computed tomography (CT) in the staging in pediatric sarcomas. Fifty pediatric patients with histologically proven sarcomas who underwent 18FDG PET/CT before treatment were evaluated retrospectively for the detection of nodal and distant metastases. Diagnostic accuracy of 18FDG PET/CT in detecting nodal and distant metastases was compared with that of 18FDG PET and conventional imaging (CI). The images were reviewed and a diagnostic consensus was reached by 3 observers. REFERENCE standard was histologic examination in 15 patients and confirmation of an obvious progression in size of the lesions on follow-up examinations. Nodal metastasis was correctly assessed in 48 patients (96%) with PET/CT, in contrast to 43 patients (86%) with PET, and 46 patients (92%) with CI. Diagnostic accuracies of nodal metastasis in 3 modalities were similar. Using PET/CT, distant metastasis was correctly assigned in 43 patients (86%), whereas interpretation based on PET alone or CI revealed distant metastasis in 33 patients (66%) and 35 patients (70%), respectively. Diagnostic accuracy of distant metastasis with PET/CT was significantly higher than that of PET (P=0.002) or CI (P=0.008). False negative results regarding distant metastasis by PET/CT in 7 patients (14%) were caused by subcentimetric lesions (n=4), bone marrow lesion (n=2), and soft tissue lesions (n=1). PET/CT is more accurate and probably more cost-effective than PET alone or CI regarding distant metastasis in pediatric sarcomas.

  7. 77 FR 71802 - Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-04

    ... ``Investigational New Drug Applications for Positron Emission Tomography (PET) Drugs.'' The guidance is intended to assist manufacturers of PET drugs in submitting investigational new drug applications (INDs). DATES... guidance entitled ``Investigational New Drug Applications for Positron Emission Tomography (PET) Drugs...

  8. Positron Emission Tomography: Current Challenges and Opportunities for Technological Advances in Clinical and Preclinical Imaging Systems

    PubMed Central

    Vaquero, Juan José; Kinahan, Paul

    2017-01-01

    Positron emission tomography (PET) imaging is based on detecting two time-coincident high-energy photons from the emission of a positron-emitting radioisotope. The physics of the emission, and the detection of the coincident photons, give PET imaging unique capabilities for both very high sensitivity and accurate estimation of the in vivo concentration of the radiotracer. PET imaging has been widely adopted as an important clinical modality for oncological, cardiovascular, and neurological applications. PET imaging has also become an important tool in preclinical studies, particularly for investigating murine models of disease and other small-animal models. However, there are several challenges to using PET imaging systems. These include the fundamental trade-offs between resolution and noise, the quantitative accuracy of the measurements, and integration with X-ray computed tomography and magnetic resonance imaging. In this article, we review how researchers and industry are addressing these challenges. PMID:26643024

  9. Positron Emission Tomography: Current Challenges and Opportunities for Technological Advances in Clinical and Preclinical Imaging Systems.

    PubMed

    Vaquero, Juan José; Kinahan, Paul

    2015-01-01

    Positron emission tomography (PET) imaging is based on detecting two time-coincident high-energy photons from the emission of a positron-emitting radioisotope. The physics of the emission, and the detection of the coincident photons, give PET imaging unique capabilities for both very high sensitivity and accurate estimation of the in vivo concentration of the radiotracer. PET imaging has been widely adopted as an important clinical modality for oncological, cardiovascular, and neurological applications. PET imaging has also become an important tool in preclinical studies, particularly for investigating murine models of disease and other small-animal models. However, there are several challenges to using PET imaging systems. These include the fundamental trade-offs between resolution and noise, the quantitative accuracy of the measurements, and integration with X-ray computed tomography and magnetic resonance imaging. In this article, we review how researchers and industry are addressing these challenges.

  10. Comparing whole body 18F-2-deoxyglucose positron emission tomography and technetium-99m methylene diophosphate bone scan to detect bone metastases in patients with non-small cell lung cancer.

    PubMed

    Hsia, T C; Shen, Y Y; Yen, R F; Kao, C H; Changlai, S P

    2002-01-01

    Despite advances in morphological imaging, some patients with non-small cell lung cancer (NSCLC) are found to have non-resectable disease at surgery or die of recurrence within a year of surgery. At present, metastatic bone involvement is usually assessed using conventional technetium-99m methylene diophosphate (Tc-99m MDP) whole body bone scan (bone scan), which has a high sensitivity but a poor specificity. We have attempted to evaluate the usefulness of whole body positron emission tomography with 18F-2-deoxyglucose (FDG-PET) for the detection of malignant bone metastases of NSCLC, and to compare FDG-PET results with Bone Scan findings. Forty-eight patients with biopsy-proven NSCLC and suspected to have stage IV disease underwent whole body bone scan and FDG-PET to detect bone metastases. The final diagnoses of bone metastases were established by operative, histopathological findings or clinical follow-up longer than 1 year by additional radiographs or following FDG-PET/Tc-99m MDP bone scan findings showing progressively and extensively widespread bone lesions. A total of 138 bone lesions found on either FDG-PET or Tc-99m MDP bone scan were evaluated. Among the 106 metastatic and 32 benign bone lesions, FDG-PET and Tc-99m MDP bone scan could accurately diagnose 99 and 98, as well as 30 and 2 metastatic and benign bone lesions, respectively. Diagnostic sensitivity and accuracy of FDG-PET and Tc-99m MDP bone scan were 93.4% and 92.5%, as well as 93.5% and 72.5%, respectively. In conclusion, our data suggest that FDG-PET with the same sensitivity and a better accuracy than those of Tc-99m MDP bone scan to detect metastatic bone lesions in patients with biopsy-proven NSCLC and suspected to have stage IV disease.

  11. Silent myocardial ischemia detected by single photon emission computed tomography (SPECT) and risk of cardiac events among asymptomatic patients with type 2 diabetes: a meta-analysis of prospective studies.

    PubMed

    Zhang, Lihua; Li, Hong; Zhang, Simin; Jaacks, Lindsay M; Li, Yufeng; Ji, Linong

    2014-01-01

    To assess the value of detecting silent myocardial ischemia (SMI) by single photon emission computed tomography (SPECT) in predicting risk of cardiac events among patients with type 2 diabetes mellitus (T2DM) who do not have overt cardiac symptoms. Electronic databases (PubMed, Cochrane Library, EMBASE, and others) and original article references were systematically searched through February 1, 2013. A fixed-effects model was applied to pooled data to estimate relative risks (RR) and 95% confidence intervals (CI). Ten prospective studies with follow-up ranging from 1 to 6 years were identified. Among the total of 1360 asymptomatic patients with T2DM screened by SPECT, the cumulative prevalence rate of SMI was 26.1%. Patients with SMI were at increased risk of experiencing endpoints relative to patients without SMI: RR (95% CI) for cardiac death, 4.60 (1.78-11.84); non-fatal cardiac events, 3.48 (2.30-5.28); total cardiac events, 3.48 (2.59-4.68); and all-cause mortality, 2.20 (1.14-4.25). The risk of cardiac death and non-fatal cardiac events increased with increasing severity of SPECT-detected abnormalities. SMI detected by SPECT is associated with increased risk of cardiac death, all-cause mortality, and non-fatal cardiac events in T2DM patients without overt cardiac symptoms. Advanced intervention procedures including intensive drug management should be implemented to reduce the risk of cardiac events for SMI-positive T2DM patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Markerless motion tracking of awake animals in positron emission tomography.

    PubMed

    Kyme, Andre; Se, Stephen; Meikle, Steven; Angelis, Georgios; Ryder, Will; Popovic, Kata; Yatigammana, Dylan; Fulton, Roger

    2014-11-01

    Noninvasive functional imaging of awake, unrestrained small animals using motion-compensation removes the need for anesthetics and enables an animal's behavioral response to stimuli or administered drugs to be studied concurrently with imaging. While the feasibility of motion-compensated radiotracer imaging of awake rodents using marker-based optical motion tracking has been shown, markerless motion tracking would avoid the risk of marker detachment, streamline the experimental workflow, and potentially provide more accurate pose estimates over a greater range of motion. We have developed a stereoscopic tracking system which relies on native features on the head to estimate motion. Features are detected and matched across multiple camera views to accumulate a database of head landmarks and pose is estimated based on 3D-2D registration of the landmarks to features in each image. Pose estimates of a taxidermal rat head phantom undergoing realistic rat head motion via robot control had a root mean square error of 0.15 and 1.8 mm using markerless and marker-based motion tracking, respectively. Markerless motion tracking also led to an appreciable reduction in motion artifacts in motion-compensated positron emission tomography imaging of a live, unanesthetized rat. The results suggest that further improvements in live subjects are likely if nonrigid features are discriminated robustly and excluded from the pose estimation process.

  13. Cyclotrons and positron emission tomography radiopharmaceuticals for clinical imaging.

    PubMed

    Saha, G B; MacIntyre, W J; Go, R T

    1992-07-01

    Positron emission tomography (PET) requires positron-emitting radionuclides that emit 511-keV photons detectable by PET imagers. Positron-emitting radionuclides are commonly produced in charged particle accelerators, eg, linear accelerators or cyclotrons. The most widely available radiopharmaceuticals for PET imaging are carbon-11-, nitrogen-13-, and oxygen-15-labeled compounds, many of which, either in their normal state or incorporated in other compounds, serve as physiological tracers. Other useful PET radiopharmaceuticals include fluorine-18-, bromine-75-, gallium-68 (68Ga)-, rubidium-82 (82Rb)-, and copper-62 (62Cu)-labeled compounds. Many positron emitters have short half-lives and thus require on-site cyclotrons for application, and others (68Ga, 82Rb, and 62Cu) are available from radionuclides generators using relatively long-lived parent radionuclides. This review is divided into two sections: cyclotrons and PET radiopharmaceuticals for clinical imaging. In the cyclotron section, the principle of operation of the cyclotron, types of cyclotrons, medical cyclotrons, and production of radionuclides are discussed. In the section on PET radiopharmaceuticals, the synthesis and clinical use of PET radiopharmaceuticals are described.

  14. Quantitative Cardiac Positron Emission Tomography: The Time Is Coming!

    PubMed Central

    Sciagrà, Roberto

    2012-01-01

    In the last 20 years, the use of positron emission tomography (PET) has grown dramatically because of its oncological applications, and PET facilities are now easily accessible. At the same time, various groups have explored the specific advantages of PET in heart disease and demonstrated the major diagnostic and prognostic role of quantitation in cardiac PET. Nowadays, different approaches for the measurement of myocardial blood flow (MBF) have been developed and implemented in user-friendly programs. There is large evidence that MBF at rest and under stress together with the calculation of coronary flow reserve are able to improve the detection and prognostication of coronary artery disease. Moreover, quantitative PET makes possible to assess the presence of microvascular dysfunction, which is involved in various cardiac diseases, including the early stages of coronary atherosclerosis, hypertrophic and dilated cardiomyopathy, and hypertensive heart disease. Therefore, it is probably time to consider the routine use of quantitative cardiac PET and to work for defining its place in the clinical scenario of modern cardiology. PMID:24278760

  15. Imaging pancreatic islet cells by positron emission tomography

    PubMed Central

    Li, Junfeng; Karunananthan, Johann; Pelham, Bradley; Kandeel, Fouad

    2016-01-01

    It was estimated that every year more than 30000 persons in the United States - approximately 80 people per day - are diagnosed with type 1 diabetes (T1D). T1D is caused by autoimmune destruction of the pancreatic islet (β cells) cells. Islet transplantation has become a promising therapy option for T1D patients, while the lack of suitable tools is difficult to directly evaluate of the viability of the grafted islet over time. Positron emission tomography (PET) as an important non-invasive methodology providing high sensitivity and good resolution, is able to accurate detection of the disturbed biochemical processes and physiological abnormality in living organism. The successful PET imaging of islets would be able to localize the specific site where transplanted islets engraft in the liver, and to quantify the level of islets remain alive and functional over time. This information would be vital to establishing and evaluating the efficiency of pancreatic islet transplantation. Many novel imaging agents have been developed to improve the sensitivity and specificity of PET islet imaging. In this article, we summarize the latest developments in carbon-11, fluorine-18, copper-64, and gallium-68 labeled radioligands for the PET imaging of pancreatic islet cells. PMID:27721939

  16. Quantitative single-photon emission computed tomography/computed tomography for technetium pertechnetate thyroid uptake measurement.

    PubMed

    Lee, Hyunjong; Kim, Ji Hyun; Kang, Yeon-Koo; Moon, Jae Hoon; So, Young; Lee, Won Woo

    2016-07-01

    Technetium pertechnetate (TcO4) is a radioactive tracer used to assess thyroid function by thyroid uptake system (TUS). However, the TUS often fails to deliver accurate measurements of the percent of thyroid uptake (%thyroid uptake) of TcO4. Here, we investigated the usefulness of quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) after injection of TcO4 in detecting thyroid function abnormalities. We retrospectively reviewed data from 50 patients (male:female = 15:35; age, 46.2 ± 16.3 years; 17 Graves disease, 13 thyroiditis, and 20 euthyroid). All patients underwent TcO4 quantitative SPECT/CT (185 MBq = 5 mCi), which yielded %thyroid uptake and standardized uptake value (SUV). Twenty-one (10 Graves disease and 11 thyroiditis) of the 50 patients also underwent conventional %thyroid uptake measurements using a TUS. Quantitative SPECT/CT parameters (%thyroid uptake, SUVmean, and SUVmax) were the highest in Graves disease, second highest in euthyroid, and lowest in thyroiditis (P < 0.0001, Kruskal-Wallis test). TUS significantly overestimated the %thyroid uptake compared with SPECT/CT (P < 0.0001, paired t test) because other TcO4 sources in addition to thyroid, such as salivary glands and saliva, contributed to the %thyroid uptake result by TUS, whereas %thyroid uptake, SUVmean and SUVmax from the SPECT/CT were associated with the functional status of thyroid. Quantitative SPECT/CT is more accurate than conventional TUS for measuring TcO4 %thyroid uptake. Quantitative measurements using SPECT/CT may facilitate more accurate assessment of thyroid tracer uptake.

  17. Quantitative single-photon emission computed tomography/computed tomography for technetium pertechnetate thyroid uptake measurement

    PubMed Central

    Lee, Hyunjong; Kim, Ji Hyun; Kang, Yeon-koo; Moon, Jae Hoon; So, Young; Lee, Won Woo

    2016-01-01

    Abstract Objectives: Technetium pertechnetate (99mTcO4) is a radioactive tracer used to assess thyroid function by thyroid uptake system (TUS). However, the TUS often fails to deliver accurate measurements of the percent of thyroid uptake (%thyroid uptake) of 99mTcO4. Here, we investigated the usefulness of quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) after injection of 99mTcO4 in detecting thyroid function abnormalities. Materials and methods: We retrospectively reviewed data from 50 patients (male:female = 15:35; age, 46.2 ± 16.3 years; 17 Graves disease, 13 thyroiditis, and 20 euthyroid). All patients underwent 99mTcO4 quantitative SPECT/CT (185 MBq = 5 mCi), which yielded %thyroid uptake and standardized uptake value (SUV). Twenty-one (10 Graves disease and 11 thyroiditis) of the 50 patients also underwent conventional %thyroid uptake measurements using a TUS. Results: Quantitative SPECT/CT parameters (%thyroid uptake, SUVmean, and SUVmax) were the highest in Graves disease, second highest in euthyroid, and lowest in thyroiditis (P < 0.0001, Kruskal–Wallis test). TUS significantly overestimated the %thyroid uptake compared with SPECT/CT (P < 0.0001, paired t test) because other 99mTcO4 sources in addition to thyroid, such as salivary glands and saliva, contributed to the %thyroid uptake result by TUS, whereas %thyroid uptake, SUVmean and SUVmax from the SPECT/CT were associated with the functional status of thyroid. Conclusions: Quantitative SPECT/CT is more accurate than conventional TUS for measuring 99mTcO4 %thyroid uptake. Quantitative measurements using SPECT/CT may facilitate more accurate assessment of thyroid tracer uptake. PMID:27399139

  18. Positron Emission Tomography for the Assessment of Myocardial Viability

    PubMed Central

    2005-01-01

    Executive Summary Objective The objective was to update the 2001 systematic review conducted by the Institute For Clinical Evaluative Sciences (ICES) on the use of positron emission tomography (PET) in assessing myocardial viability. The update consisted of a review and analysis of the research evidence published since the 2001 ICES review to determine the effectiveness and cost-effectiveness of PET in detecting left ventricular (LV) viability and predicting patient outcomes after revascularization in comparison with other noninvasive techniques. Background Left Ventricular Viability Heart failure is a complex syndrome that impairs the contractile ability of the heart to maintain adequate blood circulation, resulting in poor functional capacity and increased risk of morbidity and mortality. It is the leading cause of hospitalization in elderly Canadians. In more than two-thirds of cases, heart failure is secondary to coronary heart disease. It has been shown that dysfunctional myocardium resulting from coronary heart disease (CAD) may recover contractile function (i.e. considered viable). Dysfunctional but viable myocardium may have been stunned by a brief episode of ischemia, followed by restoration of perfusion, and may regain function spontaneously. It is believed that repetitive stunning results in hibernating myocardium that will only regain contractile function upon revascularization. For people with CAD and severe LV dysfunction (left ventricular ejection fraction [LVEF] <35%) refractory to medical therapy, coronary artery bypass and heart transplantation are the only treatment options. The opportunity for a heart transplant is limited by scarcityof donor hearts. Coronary artery bypass in these patients is associated with high perioperative complications; however, there is evidence that revascularization in the presence of dysfunctional but viable myocardium is associated with survival benefits and lower rates of cardiac events. The assessment of left

  19. High-resolution(18)F-fluorodeoxyglucose positron emission tomography and magnetic resonance imaging for pituitary adenoma detection in Cushing disease.

    PubMed

    Chittiboina, Prashant; Montgomery, Blake K; Millo, Corina; Herscovitch, Peter; Lonser, Russell R

    2015-04-01

    OBJECT High-resolution PET (hrPET) performed using a high-resolution research tomograph is reported as having a resolution of 2 mm and could be used to detect corticotroph adenomas through uptake of(18)F-fluorodeoxyglucose ((18)F-FDG). To determine the sensitivity of this imaging modality, the authors compared(18)F-FDG hrPET and MRI detection of pituitary adenomas in Cushing disease (CD). METHODS Consecutive patients with CD who underwent preoperative(18)F-FDG hrPET and MRI (spin echo [SE] and spoiled gradient recalled [SPGR] sequences) were prospectively analyzed. Standardized uptake values (SUVs) were calculated from hrPET and were compared with MRI findings. Imaging findings were correlated to operative and histological findings. RESULTS Ten patients (7 females and 3 males) were included (mean age 30.8 ± 19.3 years; range 11-59 years). MRI revealed a pituitary adenoma in 4 patients (40% of patients) on SE and 7 patients (70%) on SPGR sequences.(18)F-FDG hrPET demonstrated increased(18)F-FDG uptake consistent with an adenoma in 4 patients (40%; adenoma size range 3-14 mm). Maximum SUV was significantly higher for(18)F-FDG hrPET-positive tumors (difference = 5.1, 95% CI 2.1-8.1; p = 0.004) than for(18)F-FDG hrPET-negative tumors.(18)F-FDG hrPET positivity was not associated with tumor volume (p = 0.2) or dural invasion (p = 0.5). Midnight and morning ACTH levels were associated with(18)F-FDG hrPET positivity (p = 0.01 and 0.04, respectively) and correlated with the maximum SUV (R = 0.9; p = 0.001) and average SUV (R = 0.8; p = 0.01). All(18)F-FDG hrPET-positive adenomas had a less than a 180% ACTH increase and(18)F-FDG hrPET-negative adenomas had a greater than 180% ACTH increase after CRH stimulation (p = 0.03). Three adenomas were detected on SPGR MRI sequences that were not detected by(18)F-FDG hrPET imaging. Two adenomas not detected on SE (but no adenomas not detected on SPGR) were detected on(18)F-FDG hrPET. CONCLUSIONS While(18)F-FDG hrPET imaging can

  20. Positron Emission Tomography (PET) in Oncology

    PubMed Central

    Gallamini, Andrea; Zwarthoed, Colette; Borra, Anna

    2014-01-01

    Since its introduction in the early nineties as a promising functional imaging technique in the management of neoplastic disorders, FDG-PET, and subsequently FDG-PET/CT, has become a cornerstone in several oncologic procedures such as tumor staging and restaging, treatment efficacy assessment during or after treatment end and radiotherapy planning. Moreover, the continuous technological progress of image generation and the introduction of sophisticated software to use PET scan as a biomarker paved the way to calculate new prognostic markers such as the metabolic tumor volume (MTV) and the total amount of tumor glycolysis (TLG). FDG-PET/CT proved more sensitive than contrast-enhanced CT scan in staging of several type of lymphoma or in detecting widespread tumor dissemination in several solid cancers, such as breast, lung, colon, ovary and head and neck carcinoma. As a consequence the stage of patients was upgraded, with a change of treatment in 10%–15% of them. One of the most evident advantages of FDG-PET was its ability to detect, very early during treatment, significant changes in glucose metabolism or even complete shutoff of the neoplastic cell metabolism as a surrogate of tumor chemosensitivity assessment. This could enable clinicians to detect much earlier the effectiveness of a given antineoplastic treatment, as compared to the traditional radiological detection of tumor shrinkage, which usually takes time and occurs much later. PMID:25268160

  1. Positron emission tomography and computed tomography assessments of the aging human brain

    SciTech Connect

    de Leon, M.J.; George, A.E.; Ferris, S.H.; Christman, D.R.; Fowler, J.S.; Gentes, C.I.; Brodie, J.; Reisberg, B.; Wolf, A.P.

    1984-02-01

    The relationship between alterations in brain structure and brain function was studied in vivo in both young and elderly human subjects. Computed tomography revealed significant age-related ventricular and cortical sulcal dilatation. The cortical changes were most closely related to age. Positron emission tomography failed to show regional changes in brain glucose metabolic rate. The results suggest that the normal aging brain undergoes structural atrophic changes without incurring regional metabolic changes. Examination of the correlations between the structural and the metabolic measures revealed no significant relationships. These data are discussed with respect to the significant structure-function relationships that have been reported in Alzheimer disease. 27 references, 3 figures, 2 tables.

  2. Depiction of ventriculoperitoneal shunt obstruction with single-photon emission computed tomography/computed tomography.

    PubMed

    Aksoy, Sabire Yılmaz; Vatankulu, Betül; Uslu, Lebriz; Halac, Metin

    2016-01-01

    An 83-year-old male patient with ventriculoperitoneal shunt underwent radionuclide shunt study using single-photon emission computed tomography/computed tomography (SPECT/CT) to evaluate the shunt patency. The planar images showed activity at the cranial region and spinal canal but no significant activity at the peritoneal cavity. However, SPECT/CT images clearly demonstrated accumulation of activity at the superior part of bifurcation level with no activity at the distal end of shunt as well as no spilling of radiotracer into the peritoneal cavity indicating shunt obstruction. SPECT/CT makes the interpretation of radionuclide shunt study more accurate and easier as compared with traditional planar images.

  3. Value and limitation of stress thallium-201 single photon emission computed tomography: comparison with nitrogen-13 ammonia positron tomography

    SciTech Connect

    Tamaki, N.; Yonekura, Y.; Senda, M.; Yamashita, K.; Koide, H.; Saji, H.; Hashimoto, T.; Fudo, T.; Kambara, H.; Kawai, C.

    1988-07-01

    The diagnostic value of exercise /sup 201/Tl single photon emission computed tomography (SPECT) for assessing coronary artery disease (CAD) was comparatively evaluated with exercise (13N) ammonia positron emission tomography (PET). Fifty-one patients underwent both stress-delayed SPECT imaging using a rotational gamma camera and stress-rest PET imaging using a high resolution PET camera. Of 48 CAD patients, SPECT showed abnormal perfusion in 46 patients (96%), while PET detected perfusion abnormalities in 47 (98%). The sensitivity for detecting disease in individual coronary arteries (greater than 50% stenosis) was also similar for SPECT (81%) and PET (88%). When their interpretations were classified as normal, transient defect, and fixed defect in 765 myocardial segments, SPECT and PET findings were concordant in 606 segments (79%). However, 66 segments showed a fixed defect by SPECT but a transient defect by PET, whereas there were only nine segments showing a transient defect by SPECT and a fixed defect by PET. PET identified transient defects in 34% of the myocardial segments showing a fixed defect by SPECT. We conclude that both stress SPECT and PET showed high and similar sensitivities for detecting CAD and individual stenosed vessels. Since stress-delayed SPECT with single tracer injection detected fewer transient defects, it may underestimate the presence of myocardial ischemia, compared with high resolution PET imaging with two tracer injections.

  4. Role of Positron Emission Tomography-Computed Tomography in the Management of Anal Cancer

    SciTech Connect

    Mistrangelo, Massimiliano; Pelosi, Ettore; Bello, Marilena; Ricardi, Umberto; Milanesi, Enrica; Cassoni, Paola; Baccega, Massimo; Filippini, Claudia; Racca, Patrizia; Lesca, Adriana; Munoz, Fernando H.; Fora, Gianluca; Skanjeti, Andrea; Cravero, Francesca; Morino, Mario

    2012-09-01

    Purpose: Pre- and post-treatment staging of anal cancer are often inaccurate. The role of positron emission tomograpy-computed tomography (PET-CT) in anal cancer is yet to be defined. The aim of the study was to compare PET-CT with CT scan, sentinel node biopsy results of inguinal lymph nodes, and anal biopsy results in staging and in follow-up of anal cancer. Methods and Materials: Fifty-three consecutive patients diagnosed with anal cancer underwent PET-CT. Results were compared with computed tomography (CT), performed in 40 patients, and with sentinel node biopsy (SNB) (41 patients) at pretreatment workup. Early follow-up consisted of a digital rectal examination, an anoscopy, a PET-CT scan, and anal biopsies performed at 1 and 3 months after the end of treatment. Data sets were then compared. Results: At pretreatment assessment, anal cancer was identified by PET-CT in 47 patients (88.7%) and by CT in 30 patients (75%). The detection rates rose to 97.9% with PET-CT and to 82.9% with CT (P=.042) when the 5 patients who had undergone surgery prior to this assessment and whose margins were positive at histological examination were censored. Perirectal and/or pelvic nodes were considered metastatic by PET-CT in 14 of 53 patients (26.4%) and by CT in 7 of 40 patients (17.5%). SNB was superior to both PET-CT and CT in detecting inguinal lymph nodes. PET-CT upstaged 37.5% of patients and downstaged 25% of patients. Radiation fields were changed in 12.6% of patients. PET-CT at 3 months was more accurate than PET-CT at 1 month in evaluating outcomes after chemoradiation therapy treatment: sensitivity was 100% vs 66.6%, and specificity was 97.4% vs 92.5%, respectively. Median follow-up was 20.3 months. Conclusions: In this series, PET-CT detected the primary tumor more often than CT. Staging of perirectal/pelvic or inguinal lymph nodes was better with PET-CT. SNB was more accurate in staging inguinal lymph nodes.

  5. Positron emission tomography reveals a leiomyosarcoma causing proteinuria.

    PubMed

    Hegner, B; Krakamp, B; Hedde, J P; Brockmann, M; Weber, M; Schulze-Lohoff, E

    2003-08-01

    Obstruction of the renal veins may result in proteinuria and is frequently caused by thrombosis or tumorous processes. Since thrombosis and malignancy may occur simultaneously in the venous outflow of the kidneys, search for an underlying intraluminal tumor may be impeded by extensive thrombosis in the lumen of renal and caval veins. We report the case of a 30-year-old man with moderate proteinuria which was caused by an obstructing process of the vena cava inferior and the renal veins. While the obstructive mass was initially misdiagnosed as thrombosis, positron emission tomography helped to reveal the tumorous character of the lesion and fine-needle biopsy allowed rapid diagnosis of a leiomyosarcoma originating from the caval or renal veins. We conclude that undelayed diagnosis of the cause of renal and caval vein obstruction is facilitated by early positron emission tomography and subsequent fine-needle biopsy to identify possible tumorous lesions.

  6. The improved accuracy of planar bone scintigraphy by adding single photon emission computed tomography (SPECT-CT) to detect skeletal metastases from prostate cancer.

    PubMed

    McLoughlin, L C; O'Kelly, F; O'Brien, C; Sheikh, M; Feeney, J; Torreggiani, W; Thornhill, J A

    2016-02-01

    Planar bone scintigraphy (PBS) is a standard radiological technique to detect skeletal metastases from prostate cancer (PC), the addition of SPECT-CT to PBS improves its diagnostic accuracy. The aim of this study was to assess the additional value of targeted SPECT-CT with PBS in detecting skeletal metastasis form prostate cancer, considering resource implications in an Irish hospital setting. 54 PC patients with increased radiotracer uptake on PBS were retrospectively recruited from 2012 to 2013. All underwent targeted evaluation with SPECT-CT. PBS and SPECT-CT images were reviewed by two nuclear medicine radiologists and reported independently. The final diagnosis was made based on the CT finding corresponding to the area of radiotracer uptake. The mean age was 70.9 years (48-88 years) and median PSA at presentation was 13.9 ng/ml (4.2-215 ng/ml). 68.5 % (n = 37) men received treatment for PC while 31.5 % (n = 17) patients had not received treatment prior to PBS. 164 areas of increased radiotracer uptake were identified on PBS; 13 areas were characterised as metastatic on SPECT-CT; iliac bone (n = 3), ribs (n = 1), skull (n = 2), sacrum (n = 1), ischium (n = 1), femur (n = 3), thoracic spine (n = 1) and cervical spine (n = 1). 151 areas were characterised as benign on SPECT-CT. One area of increased radiotracer uptake in the ribs was subsequently described as indeterminate after evaluation with SPECT-CT. SPECT-CT improves the diagnostic accuracy of PBS in detecting skeletal metastasis from PC and is superior to PBS alone in differentiating benign from malignant lesions. Notwithstanding resource implications of increased cost, specialist equipment and specialist manpower hours; we recommend the use of SPECT-CT in conjunction with PBS for targeted evaluation of suspicious bony lesions in this cohort of patients.

  7. Magnetic resonance imaging and positron emission tomography of band heterotopia.

    PubMed

    Miura, K; Watanabe, K; Maeda, N; Matsumoto, A; Kumagai, T; Ito, K; Kato, T

    1993-01-01

    A case of band heterotopia was reported with findings of positron emission tomography (PET). The patient was an 8-year-old girl who had mild mental retardation and intractable partial epilepsy. Her MRI showed another diffuse layer of gray matter underlying the normal-looking cortex and separated from it by an apparently normal layer of white matter. PET scan with [18F]fluorodeoxyglucose revealed that band heterotopia had the same degree of glucose metabolism as that of the overlying cortex.

  8. Technology related parameters affecting quantification in positron emission tomography imaging.

    PubMed

    Visvikis, D; Turzo, A; Bizais, Y; Cheze-Le Rest, C

    2004-07-01

    Some of the issues associated with positron emission tomography (PET) technology which still pose challenges for the recovery of quantitative images are discussed. Through these issues reference to what is today considered as the 'gold standard' in quantitative PET imaging is also presented. A brief comparison of 2-D and 3-D PET is given, together with a short discussion of combined PET/CT imaging devices.

  9. Current and future technological trends in positron emission tomography.

    PubMed

    Karp, J S; Freifelder, R

    1992-04-01

    Current trends in positron emission tomography (PET) instrumentation are examined, with an emphasis on providing information suitable to the prospective PET user. Basic principles underlying PET are explained and information on performance measurements, techniques, and quantitation are given in order to allow the user to compare and contrast different types of PET scanners. These scanner designs are described. Specific examples are given and the combination of PET with other modalities is discussed.

  10. Revisiting stopping rules for iterative methods used in emission tomography.

    PubMed

    Guo, Hongbin; Renaut, Rosemary A

    2011-07-01

    The expectation maximization algorithm is commonly used to reconstruct images obtained from positron emission tomography sinograms. For images with acceptable signal to noise ratios, iterations are terminated prior to convergence. A new quantitative and reproducible stopping rule is designed and validated on simulations using a Monte-Carlo generated transition matrix with a Poisson noise distribution on the sinogram data. Iterations are terminated at the solution which yields the most probable estimate of the emission densities while matching the sinogram data. It is more computationally efficient and more accurate than the standard stopping rule based on the Pearson's χ(2) test.

  11. Utility of (18)F-choline photon emission tomography/computed tomography in the diagnosis of parathyroid adenoma.

    PubMed

    Damle, Nishikant Avinash; Tripathi, Madhavi; Behera, Abhishek; Aggarwal, Sameer; Bal, Chandrasekhar; Aggarwal, Shipra; Aggarwal, Vivek; Kandasamy, Devasenathipathi; Taywade, Sameer

    2016-01-01

    Recently, the role of (18)F-choline in the detection of parathyroid adenomas has been reported. At our institution, we are currently studying the role of this tracer in comparison to the standard methoxy-isobutyl-isonitrile.(MIBI) scan with single photon emission tomography/computed tomography. Our initial results show that (18)F-choline is at least as good as 99mTc-MIBI scan. We present here a representative case of a 45-year-old woman with multiple skeletal lytic lesions and a high parathyroid hormone.(PTH) who underwent both these imaging techniques with concordant results, further confirmed by histopathology and postoperative fall in serum PTH levels.

  12. Utility of 18F-choline photon emission tomography/computed tomography in the diagnosis of parathyroid adenoma

    PubMed Central

    Damle, Nishikant Avinash; Tripathi, Madhavi; Behera, Abhishek; Aggarwal, Sameer; Bal, Chandrasekhar; Aggarwal, Shipra; Aggarwal, Vivek; Kandasamy, Devasenathipathi; Taywade, Sameer

    2016-01-01

    Recently, the role of 18F-choline in the detection of parathyroid adenomas has been reported. At our institution, we are currently studying the role of this tracer in comparison to the standard methoxy-isobutyl-isonitrile.(MIBI) scan with single photon emission tomography/computed tomography. Our initial results show that 18F-choline is at least as good as 99mTc-MIBI scan. We present here a representative case of a 45-year-old woman with multiple skeletal lytic lesions and a high parathyroid hormone.(PTH) who underwent both these imaging techniques with concordant results, further confirmed by histopathology and postoperative fall in serum PTH levels. PMID:27385893

  13. Intracranial Leptomeningeal Carcinomatosis in Three Cases from Breast Cancer Demonstrated on F-18 Fluorodeoxyglucose Positron Emission Tomography/Computerized Tomography.

    PubMed

    Ortapamuk, Hulya; Demir, Mustafa Kemal

    2017-01-01

    Leptomeningeal carcinomatosis (LC) is an uncommon late manifestation of non-central nervous system (CNS) solid tumors. With prolonged survival in solid tumors, an increased frequency of metastases is noted in these tumors too. The detection of tumor cells in the cerebrospinal fluid remains the gold standard. Noninvasively, magnetic resonance imaging is frequently used for the diagnosis of LC. Although its low sensitivity of F-18 fluorodeoxyglucose positron emission tomography/computerized tomography (F-18 FDG PET/CT) on demonstrating CNS lesions, it could be useful in identifying the possibility of LC of breast carcinoma by giving high attention to the meninges. We discuss here three cases all of them having intracranial LC; where (18)F-FDG PET/CT study helped us in the diagnosis of LC. To our knowledge, this is the second report about intracranial LC from breast cancer demonstrating on (18)F-FDG PET/CT.

  14. Intracranial Leptomeningeal Carcinomatosis in Three Cases from Breast Cancer Demonstrated on F-18 Fluorodeoxyglucose Positron Emission Tomography/Computerized Tomography

    PubMed Central

    Ortapamuk, Hulya; Demir, Mustafa Kemal

    2017-01-01

    Leptomeningeal carcinomatosis (LC) is an uncommon late manifestation of non-central nervous system (CNS) solid tumors. With prolonged survival in solid tumors, an increased frequency of metastases is noted in these tumors too. The detection of tumor cells in the cerebrospinal fluid remains the gold standard. Noninvasively, magnetic resonance imaging is frequently used for the diagnosis of LC. Although its low sensitivity of F-18 fluorodeoxyglucose positron emission tomography/computerized tomography (F-18 FDG PET/CT) on demonstrating CNS lesions, it could be useful in identifying the possibility of LC of breast carcinoma by giving high attention to the meninges. We discuss here three cases all of them having intracranial LC; where 18F-FDG PET/CT study helped us in the diagnosis of LC. To our knowledge, this is the second report about intracranial LC from breast cancer demonstrating on 18F-FDG PET/CT. PMID:28242978

  15. ACR-SPR-STR Practice Parameter for the Performance of Cardiac Positron Emission Tomography - Computed Tomography (PET/CT) Imaging.

    PubMed

    Subramaniam, Rathan M; Janowitz, Warren R; Johnson, Geoffrey B; Lodge, Martin A; Parisi, Marguerite T; Ferguson, Mark R; Hellinger, Jeffrey C; Gladish, Gregory W; Gupta, Narainder K

    2017-09-15

    This clinical practice parameter has been developed collaboratively by the American College of Radiology (ACR), the Society for Pediatric Radiology (SPR), and the Society of Thoracic Radiology (STR). This document is intended to act as a guide for physicians performing and interpreting positron emission tomography-computed tomography (PET/CT) of cardiac diseases in adults and children. The primary value of cardiac PET/CT imaging include evaluation of perfusion, function, viability, inflammation, anatomy, and risk stratification for cardiac-related events such as myocardial infarction and death. Optimum utility of cardiac PET/CT is achieved when images are interpreted in conjunction with clinical information and laboratory data. Measurement of myocardial blood flow, coronary flow reserve and detection of balanced ischemia are significant advantages of cardiac PET perfusion studies. Increasingly cardiac PET/CT is used in diagnosis and treatment response assessment for cardiac sarcoidosis.

  16. Usefulness of composite methionine-positron emission tomography/3.0-tesla magnetic resonance imaging to detect the localization and extent of early-stage Cushing adenoma.

    PubMed

    Ikeda, Hidetoshi; Abe, Takehiko; Watanabe, Kazuo

    2010-04-01

    Fifty to eighty percent of Cushing disease is diagnosed by typical endocrine responses. Recently, the number of diagnoses of Cushing disease without typical Cushing syndrome has been increasing; therefore, improving ways to determine the localization of the adenoma and making an early diagnosis is important. This study was undertaken to determine the present diagnostic accuracy for Cushing microadenoma and to compare the differences in diagnostic accuracy between MR imaging and PET/MR imaging. During the past 3 years the authors analyzed the diagnostic accuracy in a series of 35 patients with Cushing adenoma that was verified by surgical pituitary exploration. All 35 cases of Cushing disease, including 20 cases of "overt" and 15 cases of "preclinical" Cushing disease, were studied. Superconductive MR images (1.5 or 3.0 T) and composite images from FDG-PET or methionine (MET)-PET and 3.0-T MR imaging were compared with the localization of adenomas verified by surgery. The diagnostic accuracy of superconductive MR imaging for detecting the localization of Cushing microadenoma was only 40%. The causes of unsatisfactory results for superconductive MR imaging were false-negative results (10 cases), false-positive results (6 cases), and instances of double pituitary adenomas (3 cases). In contrast, the accuracy of microadenoma localization using MET-PET/3.0-T MR imaging was 100% and that of FDG-PET/3.0-T MR imaging was 73%. Moreover, the adenoma location was better delineated on MET-PET/MR images than on FDG-PET/MR images. There was no significant difference in maximum standard uptake value of adenomas evaluated by MET-PET between preclinical Cushing disease and overt Cushing disease. Composite MET-PET/3.0-T MR imaging is useful for the improvement of the delineation of Cushing microadenoma and offers high-quality detectability for early-stage Cushing adenoma.

  17. Multiphoton tomography to detect chemo- and biohazards

    NASA Astrophysics Data System (ADS)

    König, Karsten

    2015-03-01

    In vivo high-resolution multiphoton/CARS tomography provides optical biopsies with 300 nm lateral resolution with chemical fingerprints. Thousands of volunteers and patients have been investigated for early cancer diagnosis, evaluation of anti-ageing cosmetic products, and changes of cellular metabolism by UV exposure and decreased oxygen supply. The skin as the outermost and largest organ is also the major target of CB agents. Current UV-based sensors are useful for bio-aerosol sensing but not for evaluating exposed in vivo skin. Here we evaluate the use of 4D multiphoton/CARS tomographs based on near infrared femtosecond laser radiation, time-correlated single photon counting (FLIM) and white light generation by photonic crystal fibers to detect bio- and chemohazards in human in vivo skin using twophoton fluorescence, SHG, and Raman signals.

  18. Characteristics of a new automated blood sampling system for positron emission tomography

    SciTech Connect

    Eriksson, L.; Ingvar, M.; Rosenqvist, G.; Ekdahl, T.; Kappel, P.

    1995-08-01

    A new commercially available automated blood sampling system (ABSS) for positron emission tomography has been evaluated. The system uses a single BGO crystal and detects with high efficiency the annihilation radiation from tracers, labelled with positron emitting isotopes, in arterial blood. In addition the possibilities to use the ABSS as a detector in the analysis of the plasma samples with liquid chromatography techniques under flow conditions has been explored.

  19. Positron emission tomography studies in parkinsonism.

    PubMed

    Eidelberg, D

    1992-05-01

    PET imaging is a rapidly expanding technique with growing clinical utility. In this review, we have discussed the contribution of functional neuroimaging with PET in elucidating the pathophysiology of parkinsonism. In addition, we emphasize the growing role of this technique in the clinical setting. FDG/PET has become increasingly available at major medical centers and is especially suitable as an aid in the clinical assessment of patients with akinetic-rigid or other movement disorders. Although this technique is essentially quantitative and ideally suited for broad population studies, qualitative and semiquantitative approaches may suffice in the evaluation of individual patients. To the extent that several of the functional imaging models are linear with raw count rates, blood sampling may not be needed in each instance. Moreover recent advances in SPECT perfusion imaging may permit the extension of PET diagnostic criteria to other imaging modalities that are less costly and more accessible in the community setting. New statistical methods for the detection of regional metabolic covariation patterns hold special promise for the development of disease-specific imaging markers, which may permit rapid differential diagnosis, improved drug trials, and possible preclinical detection. F-dopa/PET has provided many important in vivo insights into the nigrostriatal dopamine system and its role in the development of parkinsonism. In contrast to FDG/PET, this technique demands specialized radiochemistry, plasma analysis, and modeling approaches that currently restrict its applicability to a few research PET centers. Several promising developments in radiochemical synthesis, data acquisition, and kinetic modeling may simplify the technique sufficiently to be used in the clinical domain. F-dopa/PET holds particular promise in preclinical screening of individuals at risk for Parkinson's disease on genetic or environmental grounds. This has great significance in view of the

  20. Positron Emission Tomography Computed Tomography: A Guide for the General Radiologist.

    PubMed

    Beadsmoore, Clare; Newman, David; MacIver, Duncan; Pawaroo, Davina

    2015-11-01

    Cancer remains a leading cause of death in Canada and worldwide. Whilst advances in anatomical imaging to detect and monitor malignant disease have continued over the last few decades, limitations remain. Functional imaging, such as positron emission tomography (PET), has improved the sensitivity and specificity in detecting malignant disease. In combination with computed tomography (CT), PET is now commonly used in the oncology setting and is an integral part of many cancer patients' pathways. Although initially the CT component of the study was purely for attenuation of the PET imaging and to provide anatomical coregistration, many centers now combine the PET study with a diagnostic quality contrast enhanced CT to provide one stop staging, thus refining the patient's pathway. The commonest tracer used in everyday practice is FDG (F18-fluorodeoxyglucose). There are many more tracers in routine clinical practice and those with emerging roles, such as 11C-choline, useful in the imaging of prostate cancer; 11C-methionine, useful in imaging brain tumours; C11-acetate, used in imaging hepatocellular carcinomas; 18F-FLT, which can be used as a marker of cellular proliferation in various malignancies; and F18-DOPA and various 68Ga-somatostatin analogues, used in patients with neuroendocrine tumours. In this article we concentrate on FDG PETCT as this is the most commonly available and widely utilised tracer now used to routinely stage a number of cancers. PETCT alters the stage in approximately one-third of patients compared to anatomical imaging alone. Increasingly, PETCT is being used to assess early metabolic response to treatment. Metabolic response can be seen much earlier than a change in the size/volume of the disease which is measured by standard CT imaging. This can aid treatment decisions in both in terms of modifying therapy and in addition to providing important prognostic information. Furthermore, it is helpful in patients with distorted anatomy from surgery

  1. Positron Emission Tomography in Breast Cancer

    PubMed Central

    Vercher-Conejero, Jose Luis; Pelegrí-Martinez, Laura; Lopez-Aznar, Diego; Cózar-Santiago, María del Puig

    2015-01-01

    Gradually, FDG-PET/CT has been strengthening within the diagnostic algorithms of oncological diseases. In many of these, PET/CT has shown to be useful at different stages of the disease: diagnosis, staging or re-staging, treatment response assessment, and recurrence. Some of the advantages of this imaging modality versus CT, MRI, bone scan, mammography, or ultrasound, are based on its great diagnostic capacity since, according to the radiopharmaceutical used, it reflects metabolic changes that often occur before morphological changes and therefore allows us to stage at diagnosis. Moreover, another advantage of this technique is that it allows us to evaluate the whole body so it can be very useful for the detection of distant disease. With regard to breast cancer, FDG-PET/CT has proven to be important when recurrence is suspected or in the evaluation of treatment response. The technological advancement of PET equipment through the development of new detectors and equipment designed specifically for breast imaging, and the development of more specific radiopharmaceuticals for the study of the different biological processes of breast cancer, will allow progress not only in making the diagnosis of the disease at an early stage but also in enabling personalized therapy for patients with breast cancer. PMID:26854143

  2. Shape threat detection via adaptive computed tomography

    NASA Astrophysics Data System (ADS)

    Masoudi, Ahmad; Thamvichai, Ratchaneekorn; Neifeld, Mark A.

    2016-05-01

    X-ray Computed Tomography (CT) is used widely for screening purposes. Conventional x-ray threat detection systems employ image reconstruction and segmentation algorithms prior to making threat/no-threat decisions. We find that in many cases these pre-processing steps can degrade detection performance. Therefore in this work we will investigate methods that operate directly on the CT measurements. We analyze a fixed-gantry system containing 25 x-ray sources and 2200 photon counting detectors. We present a new method for improving threat detection performance. This new method is a so-called greedy adaptive algorithm which at each time step uses information from previous measurements to design the next measurement. We utilize sequential hypothesis testing (SHT) in order to derive both the optimal "next measurement" and the stopping criterion to insure a target probability of error Pe. We find that selecting the next x-ray source according to such a greedy adaptive algorithm, we can reduce Pe by a factor of 42.4× relative to the conventional measurement sequence employing all 25 sources in sequence.

  3. [Positron emission tomography in neuroscience. An integrative part of clinical diagnostic methods and experimental research].

    PubMed

    Schaller, B

    2005-02-01

    The role of molecular neuroimaging techniques is increasing in the understanding of pathophysiological mechanism of diseases. To date, positron emission tomography is the most powerful tool for the non-invasive study of biochemical and molecular processes in humans and animals in vivo. With the development in radiochemistry and tracer technology, a variety of endogenously expressed and exogenously introduced genes can be analyzed by PET. This opens up the exciting and rapidly field of molecular imaging, aiming at the non-invasive localisation of a biological process of interest in normal and diseased cells in animal models and humans in vivo. Besides its usefulness for basic research positron emission tomography has been proven to be superior to conventional diagnostic methods in several clinical indications. This is illustrated by detection of biological or anatomic changes that cannot be demonstrated by computed tomography or magnetic resonance imaging, as well as even before symptoms are expressed. The present review summarizes the clinical use of positron emission tomography in neuroscience that has helped elucidate the pathophysiology of a number of diseases and has suggested strategies in the treatment of these patients. Special reference is given to the neurovascular, neurodegenerative and neurooncological disease.

  4. Noninvasive imaging of islet grafts using positron-emission tomography

    NASA Astrophysics Data System (ADS)

    Lu, Yuxin; Dang, Hoa; Middleton, Blake; Zhang, Zesong; Washburn, Lorraine; Stout, David B.; Campbell-Thompson, Martha; Atkinson, Mark A.; Phelps, Michael; Gambhir, Sanjiv Sam; Tian, Jide; Kaufman, Daniel L.

    2006-07-01

    Islet transplantation offers a potential therapy to restore glucose homeostasis in type 1 diabetes patients. However, islet transplantation is not routinely successful because most islet recipients gradually lose graft function. Furthermore, serological markers of islet function are insensitive to islet loss until the latter stages of islet graft rejection. A noninvasive method of monitoring islet grafts would aid in the assessment of islet graft survival and the evaluation of interventions designed to prolong graft survival. Here, we show that recombinant adenovirus can engineer isolated islets to express a positron-emission tomography (PET) reporter gene and that these islets can be repeatedly imaged by using microPET after transplantation into mice. The magnitude of signal from engineered islets implanted into the axillary cavity was directly related to the implanted islet mass. PET signals attenuated over the following weeks because of the transient nature of adenovirus-mediated gene expression. Because the liver is the preferred site for islet implantation in humans, we also tested whether islets could be imaged after transfusion into the mouse liver. Control studies revealed that both intrahepatic islet transplantation and hyperglycemia altered the biodistribution kinetics of the PET probe systemically. Although transplanted islets were dispersed throughout the liver, clear signals from the liver region of mice receiving PET reporter-expressing islets were detectable for several weeks. Viral transduction, PET reporter expression, and repeated microPET imaging had no apparent deleterious effects on islet function after implantation. These studies lay a foundation for noninvasive quantitative assessments of islet graft survival using PET. diabetes | transplantation

  5. Silicon as an Unconventional Detector in Positron Emission Tomography

    PubMed Central

    Clinthorne, N.H.; Brzezinski, K.; Chesi, E.; Cochran, E.; Grkovski, M.; Grošičar, B.; Honscheid, K.; Huh, S.; Kagan, H.; Lacasta, C.; Linhart, V.; Mikuž, M.; Smith, S.; Stankova, V.; Studen, A.; Weilhammer, P.; žontar, D.

    2012-01-01

    Positron emission tomography (PET) is a widely used technique in medical imaging and in studying small animal models of human disease. In the conventional approach, the 511 keV annihilation photons emitted from a patient or small animal are detected by a ring of scintillators such as LYSO read out by arrays of photodetectors. Although this has been a successful in achieving ~5mm FWHM spatial resolution in human studies and ~1mm resolution in dedicated small animal instruments, there is interest in significantly improving these figures. Silicon, although its stopping power is modest for 511 keV photons, offers a number of potential advantages over more conventional approaches. Foremost is its high spatial resolution in 3D: our past studies show that there is little diffculty in localizing 511 keV photon interactions to ~0.3mm. Since spatial resolution and reconstructed image noise trade off in a highly non-linear manner that depends on the PET instrument response, if high spatial resolution is the goal, silicon may outperform standard PET detectors even though it has lower sensitivity to 511 keV photons. To evaluate silicon in a variety of PET “magnifying glass” configurations, an instrument has been constructed that consists of an outer partial-ring of PET scintillation detectors into which various arrangements of silicon detectors can be inserted to emulate dual-ring or imaging probe geometries. Recent results have demonstrated 0.7 mm FWHM resolution using pad detectors having 16×32 arrays of 1.4mm square pads and setups have shown promising results in both small animal and PET imaging probe configurations. Although many challenges remain, silicon has potential to become the PET detector of choice when spatial resolution is the primary consideration. PMID:23230345

  6. Polarization sensitive optical coherence tomography detection method

    SciTech Connect

    Everett, M J; Sathyam, U S; Colston, B W; DaSilva, L B; Fried, D; Ragadio, J N; Featherstone, J D B

    1999-05-12

    This study demonstrates the potential of polarization sensitive optical coherence tomography (PS-OCT) for non-invasive in vivo detection and characterization of early, incipient caries lesions. PS-OCT generates cross-sectional images of biological tissue while measuring the effect of the tissue on the polarization state of incident light. Clear discrimination between regions of normal and demineralized enamel is first shown in PS-OCT images of bovine enamel blocks containing well-characterized artificial lesions. High-resolution, cross-sectional images of extracted human teeth are then generated that clearly discriminate between the normal and carious regions on both the smooth and occlusal surfaces. Regions of the teeth that appeared to be demineralized in the PS-OCT images were verified using histological thin sections examined under polarized light microscopy. The PS-OCT system discriminates between normal and carious regions by measuring the polarization state of the back-scattered 1310 nm light, which is affected by the state of demineralization of the enamel. Demineralization of enamel increases the scattereing coefficient, thus depolarizing the incident light. This study shows that PS-OCT has great potential for the detection, characterization, and monitoring of incipient caries lesions.

  7. Neutron stimulated emission computed tomography: a Monte Carlo simulation approach.

    PubMed

    Sharma, A C; Harrawood, B P; Bender, J E; Tourassi, G D; Kapadia, A J

    2007-10-21

    A Monte Carlo simulation has been developed for neutron stimulated emission computed tomography (NSECT) using the GEANT4 toolkit. NSECT is a new approach to biomedical imaging that allows spectral analysis of the elements present within the sample. In NSECT, a beam of high-energy neutrons interrogates a sample and the nuclei in the sample are stimulated to an excited state by inelastic scattering of the neutrons. The characteristic gammas emitted by the excited nuclei are captured in a spectrometer to form multi-energy spectra. Currently, a tomographic image is formed using a collimated neutron beam to define the line integral paths for the tomographic projections. These projection data are reconstructed to form a representation of the distribution of individual elements in the sample. To facilitate the development of this technique, a Monte Carlo simulation model has been constructed from the GEANT4 toolkit. This simulation includes modeling of the neutron beam source and collimation, the samples, the neutron interactions within the samples, the emission of characteristic gammas, and the detection of these gammas in a Germanium crystal. In addition, the model allows the absorbed radiation dose to be calculated for internal components of the sample. NSECT presents challenges not typically addressed in Monte Carlo modeling of high-energy physics applications. In order to address issues critical to the clinical development of NSECT, this paper will describe the GEANT4 simulation environment and three separate simulations performed to accomplish three specific aims. First, comparison of a simulation to a tomographic experiment will verify the accuracy of both the gamma energy spectra produced and the positioning of the beam relative to the sample. Second, parametric analysis of simulations performed with different user-defined variables will determine the best way to effectively model low energy neutrons in tissue, which is a concern with the high hydrogen content in

  8. Sooting flame thermometry using emission/absorption tomography

    NASA Astrophysics Data System (ADS)

    Hall, Robert J.; Bonczyk, Paul A.

    1990-11-01

    A sooting flame temperature measurement technique has been demonstrated based on emission-absorption tomography. The approach applies the algorithms of Fourier transform tomography to deconvolve local soot absorption coefficient and Planck function (temperature) from sets of parallel line-of-sight measurements. The technique has the advantage that it is experimentally simple and does not require involved data reduction. For small particles, there is also no sensitivity of the inferred temperature to possibly uncertain medium parameters. Its main limitation seems to be that it will not work for vanishingly small absorption, but this could be overcome in practice by seeding and then performing all work at the wavelength of a seed resonance. While in principle limited to optically thin flames, accurate corrections for moderate optical thickness can often be made. A self-consistent comparison of measured global radiation from a sooting ethylene flame with a radiative transfer calculation based on measured temperature and soot absorption parameters has been performed.

  9. Sooting flame thermometry using emission/absorption tomography.

    PubMed

    Hall, R J; Bonczyk, P A

    1990-11-01

    A sooting flame temperature measurement technique has been demonstrated based on emission-absorption tomography. The approach applies the algorithms of Fourier transform tomography to deconvolve local soot absorption coefficient and Planck function (temperature) from sets of parallel line-of-sight measurements. The technique has the advantage that it is experimentally simple and does not require involved data reduction. For small particles, there is also no sensitivity of the inferred temperature to possibly uncertain medium parameters. Its main limitation seems to be that it will not work well for vanishingly small absorption, but this could be overcome in practice by seeding and then performing all work at the wavelength of a seed resonance. While in principle limited to optically thin flames, accurate corrections for moderate optical thickness can often be made. A self-consistent comparison of measured global radiation from a sooting ethylene flame with a radiative transfer calculation based on measured temperature and soot absorption parameters has been performed.

  10. Single photon emission computed tomography in seizure disorders.

    PubMed Central

    Denays, R; Rubinstein, M; Ham, H; Piepsz, A; Noël, P

    1988-01-01

    Fourteen children with various seizure disorders were studied using a cerebral blood flow tracer, 123I iodoamphetamine (0.05 mCi/kg), and single photon emission computed tomography (SPECT). In the five patients with radiological lesions, SPECT showed congruent or more extensive abnormalities. Five of the nine children with a normal scan on computed tomography had abnormal SPECT studies consisting of focal hypoperfusion, diffuse hemispheric hypoperfusion, multifocal and bilateral hypoperfusion, or focal hyperperfusion. A focal lesion seen on SPECT has been found in children with tonic-clonic seizures suggesting secondarily generalised seizures. Moreover the pattern seen on SPECT seemed to be related to the clinical status. An extensive impairment found on SPECT was associated with a poor evolution in terms of intellectual performance and seizure frequency. Conversely all children with a normal result on SPECT had less than two seizures per year and normal neurological and intellectual development. Images Figure PMID:3264135

  11. History and future technical innovation in positron emission tomography.

    PubMed

    Jones, Terry; Townsend, David

    2017-01-01

    Instrumentation for positron emission tomography (PET) imaging has experienced tremendous improvements in performance over the past 60 years since it was first conceived as a medical imaging modality. Spatial resolution has improved by a factor of 10 and sensitivity by a factor of 40 from the early designs in the 1970s to the high-performance scanners of today. Multimodality configurations have emerged that combine PET with computed tomography (CT) and, more recently, with MR. Whole-body scans for clinical purposes can now be acquired in under 10 min on a state-of-the-art PET/CT. This paper will review the history of these technical developments over 40 years and summarize the important clinical research and healthcare applications that have been made possible by these technical advances. Some perspectives for the future of this technology will also be presented that promise to bring about new applications of this imaging modality in clinical research and healthcare.

  12. Newer positron emission tomography radiopharmaceuticals for radiotherapy planning: an overview

    PubMed Central

    Mukherjee, Anirban

    2016-01-01

    Positron emission tomography-computed tomography (PET-CT) has changed cancer imaging in the last decade, for better. It can be employed for radiation treatment planning of different cancers with improved accuracy and outcomes as compared to conventional imaging methods. 18F-fluorodeoxyglucose remains the most widely used though relatively non-specific cancer imaging PET tracer. A wide array of newer PET radiopharmaceuticals has been developed for targeted imaging of different cancers. PET-CT with such new PET radiopharmaceuticals has also been used for radiotherapy planning with encouraging results. In the present review we have briefly outlined the role of PET-CT with newer radiopharmaceuticals for radiotherapy planning and briefly reviewed the available literature in this regard. PMID:26904575

  13. Single photon emission computed tomography in AIDS dementia complex

    SciTech Connect

    Pohl, P.; Vogl, G.; Fill, H.; Roessler, H.Z.; Zangerle, R.; Gerstenbrand, F.

    1988-08-01

    Single photon emission computed tomography (SPECT) studies were performed in AIDS dementia complex using IMP in 12 patients (and HM-PAO in four of these same patients). In all patients, SPECT revealed either multiple or focal uptake defects, the latter corresponding with focal signs or symptoms in all but one case. Computerized tomography showed a diffuse cerebral atrophy in eight of 12 patients, magnetic resonance imaging exhibited changes like atrophy and/or leukoencephalopathy in two of five cases. Our data indicate that both disturbance of cerebral amine metabolism and alteration of local perfusion share in the pathogenesis of AIDS dementia complex. SPECT is an important aid in the diagnosis of AIDS dementia complex and contributes to the understanding of the pathophysiological mechanisms of this disorder.

  14. Fluorine-18 fluorodeoxyglucose positron emission tomography in the management of solitary pulmonary nodule: a review.

    PubMed

    Divisi, Duilio; Barone, Mirko; Zaccagna, Gino; Crisci, Roberto

    2017-11-01

    Solitary pulmonary nodules are common radiologic findings and their detection has increased due to the introduction and improvement of diagnostics. Since a nodule can be an expression of early lung cancers, a proper classification and management are required because its treatment might lead to decreased morbidity and mortality. In this regard, prominent guidelines are available although they are characterized sometimes by discordant and misleading evidences. Furthermore, the same results of studies in the literature appear conflicting. Aim of this work is to evaluate the role of imaging through an extensive literature review but focusing on 18-fluorine fluorodeoxyglucose positron emission tomography combined with computed tomography ((18)F-FDG-PET/CT) in order to assess the limits and future perspectives of solitary pulmonary nodule characterization in early detection of lung cancer. Key messages Detection of solitary pulmonary nodules has increased. Management of solitary pulmonary nodules is still debated. Future perspectives of early solitary pulmonary nodule characterization.

  15. Positron emission tomography scanning is coming to a hospital near you soon!

    PubMed

    Bashir, Humayun; Shabo, Gregory; Nunan, T O

    2008-04-01

    Positron emission tomography (PET) is still generally not available in the UK; however, there are plans to introduce a national service in England from April 2008. Plans are also at an advanced stage in Scotland and Wales. The main uses of PET are in preoperative staging of lung cancer, detection of recurrent colorectal cancer, and management of patients with lymphoma. Although these provide the bulk of the referral base, PET is also of use in specific situations in patients with less common cancers, such as head and neck cancer, gynaecological cancer, and melanoma. In its more common uses, PET has been shown to be cost effective. Positron emission tomography will play an increasing role in the evaluation of response to treatment to enable early separation of patients who are responding well to chemotherapy from those who are not responding and need to be transferred to another therapy.

  16. Single photon emission computed tomography in Alzheimer's disease. Abnormal iofetamine I 123 uptake reflects dementia severity

    SciTech Connect

    Johnson, K.A.; Holman, B.L.; Mueller, S.P.; Rosen, T.J.; English, R.; Nagel, J.S.; Growdon, J.H.

    1988-04-01

    To determine whether abnormalities in regional cerebral functional activity estimated by iofetamine hydrochloride I 123 and single photon emission computed tomography can be detected in mild or moderate as well as severe cases of Alzheimer's disease (AD), we performed iofetamine I 123-single photon emission computed tomography in 37 patients with probable AD (nine patients with mild, 18 patients with moderate, and ten patients with severe dementia) and nine age-matched control subjects. Iofetamine I 123 uptake was measured in right and left frontal, temporal, parietal, and occipital cortices. Mean (right and left) iofetamine I 123 activity was lowest in the parietal region of patients with AD and was significantly reduced in the other three regions compared with control subjects. Only in the parietal region was lower relative iofetamine I 123 activity associated with an impaired level of patient function and with cognitive deficit.

  17. Single photon emission computed tomography in Alzheimer's disease. Abnormal iofetamine I 123 uptake reflects dementia severity

    SciTech Connect

    Johnson, K.A.; Holman, B.L.; Mueller, S.P.; Rosen, T.J.; English, R.; Nagel, J.S.; Growdon, J.H.

    1988-04-01

    To determine whether abnormalities in regional cerebral functional activity estimated by iofetamine hydrochloride I 123 and single photon emission computed tomography can be detected in mild or moderate as well as severe cases of Alzheimer's disease (AD), we performed iofetamine I 123-single photon emission computed tomography in 37 patients with probable AD (nine patients with mild, 18 patients with moderate, and ten patients with severe dementia) and nine age-matched control subjects. Iofetamine I 123 uptake was measured in right and left frontal, temporal, parietal, and occipital cortices. Mean (right and left) iofetamine I 123 activity was lowest in the parietal region of patients with AD and was significantly reduced in the other three regions compared with control subjects. Only in the parietal region was lower relative iofetamine I 123 activity associated with an impaired level of patient function and with cognitive deficit.

  18. Brain single photon emission computed tomography: Newer activation and intervention studies

    SciTech Connect

    Tikofsky, R.S.; Hellman, R.S. )

    1991-01-01

    Single-photon emission computed tomography (SPECT) regional cerebral blood flow (rCBF) findings using non-xenon 133 tracers in combination with activation and intervention techniques are reviewed. Examination of the currently available data indicates that it is possible to detect the effects of a variety of activations and interventional procedures using SPECT rCBF with non-xenon 133 tracers. There are still many issues to be resolved before SPECT can reach the level of sophistication attained by xenon 133 and positron emission tomography in studying rCBF during activation or intervention. However, research to date indicates that SPECT rCBF studied with tracers other than xenon 133 has an excellent potential for increasing the ability to differentiate normal and pathological states. 97 refs.

  19. 4D seismics in the laboratory: Imaging using acoustic emission tomography

    NASA Astrophysics Data System (ADS)

    Brantut, Nicolas

    2017-04-01

    Over the past three decades, there has been tremendous technological developments of laboratory equipment and studies using acoustic emission and ultrasonic monitoring of rock samples during deformation. Using relatively standard seismological techniques, acoustic emissions can be detected, located in space and time, and source mechanisms can be obtained. In parallel, ultrasonic velocities can be measured routinely using standard pulse-receiver techniques. Despite these major developments, current acoustic emission and ultrasonic monitoring systems are typically used separately, and the poor spatial coverage of acoustic transducers precludes performing active 3D tomography in typical laboratory settings. Here, I present an algorithm and software package that uses both passive acoustic emission data and active ultrasonic measurements to determine acoustic emission locations together with the 3D, anistropic P-wave structure of rock samples during deformation. The technique is analogous to local earthquake tomography, but tailored to the specificities of small scale laboratory tests. The fast marching method is employed to compute the forward problem. The acoustic emission locations and the anisotropic P-wave field are jointly inverted using the Quasi-Newton method. I will present benchmark tests, as well as a real-life example showing the propagation of a compaction front in a porous sandstone.

  20. Positron Emission Tomography (PET) for benign and malignant disease

    PubMed Central

    Visioni, Anthony; Kim, Julian

    2011-01-01

    Synopsis Functional imaging using radiolabeled probes which specifically bind and accumulate in target tissues has improved the sensitivity and specificity of conventional imaging. Positron Emission Tomography using modified glucose probes (FDG-PET) has demonstrated improved diagnostic accuracy in differentiating benign from malignant lesions in the setting of solitary pulmonary nodules. In addition, FDG-PET has become a useful modality in pre-operative staging of patients with lung cancer and is being tested with many other malignancies for its ability to change patient management. This article provides an overview of the current status of FDG-PET and presents the challenges of moving towards routine use. PMID:21184913

  1. [Positron emission tomography: diagnostic imaging on a molecular level].

    PubMed

    Allemann, K; Wyss, M; Wergin, M; Bley, C Rohrer; Ametamay, S; Bruehlmeier, M; Kaser-Hotz, B

    2004-08-01

    In human medicine positron emission tomography (PET) is a modern diagnostic imaging method. In the present paper we outline the physical principles of PET and give an overview over the main clinic fields where PET is being used, such as neurology, cardiology and oncology. Moreover, we present a current project in veterinary medicine (in collaboration with the Paul Scherrer Institute and the University Hospital Zurich), where a hypoxia tracer is applied to dogs and cats suffering from spontaneous tumors. Finally new developments in the field of PET were discussed.

  2. [Positron emission tomography and scintigraphy. Nuclear imaging in clinical orthopaedics].

    PubMed

    Kirsch, C M

    2006-09-01

    Nuclear medicine uses the function of organs or organ systems to diagnose and treat disease. The source of radiation is brought into the patient's body by means of a radioactive labelled pharmaceutical. Its way through the body is recorded by appropriate equipment on the outside. Of the many nuclear medical procedures, those primarily applicable to orthopaedic problems are explained here, such as bone scintigraphy, scintigraphy of inflammatory lesions, and tumour scintigraphy. Besides their use in diagnostics, therapeutic applications are covered as well. Using examples from clinical practice, "conventional" nuclear medicine and positron emission tomography are also covered.

  3. Positron emission tomography for use in microdosing studies.

    PubMed

    Wagner, Claudia Christina; Müller, Markus; Lappin, Graham; Langer, Oliver

    2008-01-01

    Positron emission tomography (PET) imaging using microdoses of radiolabeled drug tracers is gaining increasing acceptance in modern clinical drug development. This approach is unique in that it allows for direct quantitative assessment of drug concentrations in the tissues targeted for treatment, thereby bridging the gap between pharmacokinetics and pharmacodynamics. Current applications of PET in anticancer, anti-infective and central nervous system drug research are reviewed herein. Situated at the interface of preclinical and clinical drug testing, PET microdosing is a powerful and highly innovative tool for pharmaceutical development.

  4. Quantitative simultaneous positron emission tomography and magnetic resonance imaging

    PubMed Central

    Ouyang, Jinsong; Petibon, Yoann; Huang, Chuan; Reese, Timothy G.; Kolnick, Aleksandra L.; El Fakhri, Georges

    2014-01-01

    Abstract. Simultaneous positron emission tomography and magnetic resonance imaging (PET-MR) is an innovative and promising imaging modality that is generating substantial interest in the medical imaging community, while offering many challenges and opportunities. In this study, we investigated whether MR surface coils need to be accounted for in PET attenuation correction. Furthermore, we integrated motion correction, attenuation correction, and point spread function modeling into a single PET reconstruction framework. We applied our reconstruction framework to in vivo animal and patient PET-MR studies. We have demonstrated that our approach greatly improved PET image quality. PMID:26158055

  5. Spatial emission tomography reconstruction using Pitman-Yor process

    SciTech Connect

    Fall, Mame Diarra; Mohammad-Djafari, Ali; Barat, Eric; Comtat, Claude

    2009-12-08

    In this paper, we address the problem of emission tomography spatial reconstruction in three dimensions following a Bayesian nonparametric approach. Our model makes use of a generalization of the Dirichlet process called Pitman-Yor process. The problem in this approach is to deal with the infinite representation of the distribution in the inference. So we propose an efficient Markov Chain Monte-Carlo sampling scheme which is able to generate samples from the posterior distribution of the activity distribution. An application to 3D-PET reconstruction is presented.

  6. Positron emission tomography: the conceptual idea using a multidisciplinary approach.

    PubMed

    Paans, Anne M J; van Waarde, Aren; Elsinga, Philip H; Willemsen, Antoon T M; Vaalburg, Willem

    2002-07-01

    Positron emission tomography (PET) is a method for quantitatively measuring biochemical and physiological processes in vivo by using radiopharmaceuticals labeled with positron-emitting radionuclides such as 11C, 13N, 15O, and 18F and by measuring the annihilation radiation using a coincidence technique. This technique is also used for measurement of the pharmacokinetics of labeled drugs and measurement of the effects of drugs on metabolism. Deviations from normal metabolism can be measured and insight into biological processes responsible for diseases can be obtained.

  7. Existing Pittsburgh Compound-B positron emission tomography thresholds are too high: statistical and pathological evaluation.

    PubMed

    Villeneuve, Sylvia; Rabinovici, Gil D; Cohn-Sheehy, Brendan I; Madison, Cindee; Ayakta, Nagehan; Ghosh, Pia M; La Joie, Renaud; Arthur-Bentil, Samia Kate; Vogel, Jacob W; Marks, Shawn M; Lehmann, Manja; Rosen, Howard J; Reed, Bruce; Olichney, John; Boxer, Adam L; Miller, Bruce L; Borys, Ewa; Jin, Lee-Way; Huang, Eric J; Grinberg, Lea T; DeCarli, Charles; Seeley, William W; Jagust, William

    2015-07-01

    Amyloid-β, a hallmark of Alzheimer's disease, begins accumulating up to two decades before the onset of dementia, and can be detected in vivo applying amyloid-β positron emission tomography tracers such as carbon-11-labelled Pittsburgh compound-B. A variety of thresholds have been applied in the literature to define Pittsburgh compound-B positron emission tomography positivity, but the ability of these thresholds to detect early amyloid-β deposition is unknown, and validation studies comparing Pittsburgh compound-B thresholds to post-mortem amyloid burden are lacking. In this study we first derived thresholds for amyloid positron emission tomography positivity using Pittsburgh compound-B positron emission tomography in 154 cognitively normal older adults with four complementary approaches: (i) reference values from a young control group aged between 20 and 30 years; (ii) a Gaussian mixture model that assigned each subject a probability of being amyloid-β-positive or amyloid-β-negative based on Pittsburgh compound-B index uptake; (iii) a k-means cluster approach that clustered subjects into amyloid-β-positive or amyloid-β-negative based on Pittsburgh compound-B uptake in different brain regions (features); and (iv) an iterative voxel-based analysis that further explored the spatial pattern of early amyloid-β positron emission tomography signal. Next, we tested the sensitivity and specificity of the derived thresholds in 50 individuals who underwent Pittsburgh compound-B positron emission tomography during life and brain autopsy (mean time positron emission tomography to autopsy 3.1 ± 1.8 years). Amyloid at autopsy was classified using Consortium to Establish a Registry for Alzheimer's Disease (CERAD) criteria, unadjusted for age. The analytic approaches yielded low thresholds (standard uptake value ratiolow = 1.21, distribution volume ratiolow = 1.08) that represent the earliest detectable Pittsburgh compound-B signal, as well as high thresholds (standard

  8. Fasciola Hepatica Mimicking Malignancy on 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

    PubMed Central

    Sürücü, Erdem; Demir, Yusuf; Dülger, Ahmet C.; Batur, Abdüssamed; Ölmez, Şehmus; Kitapçı, Mehmet T.

    2016-01-01

    A 48-year-old female with complaints of gastrointestinal symptoms such as abdominal pain, fatigue, vomiting, nausea, and weight loss was diagnosed with neuroendocrine tumor after removal of a 2 mm lesion from the stomach with endoscopic biopsy. Her magnetic resonance imaging that was performed due to on-going symptoms showed multiple linear hypointense lesions in the liver. Positron emission tomography/computed tomography (PET/CT) scan was performed for differential diagnosis, which showed high fluorodeoxyglucose (FDG) uptake in these lesions. Clinical and laboratory findings revealed the final diagnosis as Fasciola hepatica. The imaging features of this case is presented to aid in differentiating this infectious disease from malignancy and avoid misdiagnosis on FDG-PET/CT. PMID:27751978

  9. Combined positron emission tomography and computed tomography to visualize and quantify fluid flow in sedimentary rocks

    NASA Astrophysics Data System (ADS)

    Fernø, M. A.; Gauteplass, J.; Hauge, L. P.; Abell, G. E.; Adamsen, T. C. H.; Graue, A.

    2015-09-01

    Here we show for the first time the combined positron emission tomography (PET) and computed tomography (CT) imaging of flow processes within porous rocks to quantify the development in local fluid saturations. The coupling between local rock structure and displacement fronts is demonstrated in exploratory experiments using this novel approach. We also compare quantification of 3-D temporal and spatial water saturations in two similar CO2 storage tests in sandstone imaged separately with PET and CT. The applicability of each visualization technique is evaluated for a range of displacement processes, and the favorable implementation of combining PET/CT for laboratory core analysis is discussed. We learn that the signal-to-noise ratio (SNR) is over an order of magnitude higher for PET compared with CT for the studied processes.

  10. Depiction of ventriculoperitoneal shunt obstruction with single-photon emission computed tomography/computed tomography

    PubMed Central

    Aksoy, Sabire Yılmaz; Vatankulu, Betül; Uslu, Lebriz; Halac, Metin

    2016-01-01

    An 83-year-old male patient with ventriculoperitoneal shunt underwent radionuclide shunt study using single-photon emission computed tomography/computed tomography (SPECT/CT) to evaluate the shunt patency. The planar images showed activity at the cranial region and spinal canal but no significant activity at the peritoneal cavity. However, SPECT/CT images clearly demonstrated accumulation of activity at the superior part of bifurcation level with no activity at the distal end of shunt as well as no spilling of radiotracer into the peritoneal cavity indicating shunt obstruction. SPECT/CT makes the interpretation of radionuclide shunt study more accurate and easier as compared with traditional planar images. PMID:27385906

  11. The role of positron emission tomography/computed tomography in planning radiotherapy in endometrial cancer.

    PubMed

    Simcock, Bryony; Narayan, Kailash; Drummond, Elizabeth; Bernshaw, David; Wells, Elizabeth; Hicks, Rodney J

    2015-05-01

    The optimal method of assessing disease distribution in endometrial cancer is widely debated. Knowledge of disease distribution assists in planning adjuvant radiotherapy; in this study we used positron emission tomography/computed tomography (PET/CT) to assess disease distribution before radiotherapy. Seventy-three consecutive patients referred to the Peter MacCallum Cancer Centre for adjuvant radiotherapy for endometrial cancer, with either high-risk disease after a hysterectomy or recurrent disease, had a PET/CT before treatment. The findings on PET/CT and clinical course were recorded. PET/CT found additional disease in 35% of postoperative patients, changing planned treatment in 31%. In the group with known recurrence, additional disease was found in 72%, changing management in 36%. PET/CT is a valuable tool for planning radiotherapy in endometrial cancer.

  12. False positive diagnosis of malignancy in a case of cryptogenic organising pneumonia presenting as a pulmonary mass with mediastinal nodes detected on fluorodeoxyglucose-positron emission tomography: a case report.

    PubMed

    Ponnuswamy, Aravind; Mediratta, Neeraj; Lyburn, Iain D; Finnerty, James P

    2009-11-14

    We report the case of a patient with positive findings on a lung emission tomography/computed tomography (PET/CT) scan, with possible contra lateral mediastinal involvement, which strongly suggested an inoperable lung carcinoma. The lung mass proved to be a cryptogenic organising pneumonia. While the latter has previously been shown to be PET/CT positive, mediastinal involvement simulating malignant spread has not been previously reported. A 50-year-old Caucasian woman presented with a history of unproductive cough and was found to have a mass in the right upper lobe as shown on chest X-ray and a computed tomography scan. A subsequent PET/CT scan showed strong uptake in the right upper lobe (maximum standard uptake values (SUVmax) 9.6) with increased uptake in the adjacent mediastinum and contralateral mediastinal nodes. Surgical resection and mediastinoscopy revealed cryptogenic organising pneumonia, with enlarged reactive mediastinal lymph nodes. The case illustrates the limits of PET/CT scanning as a diagnostic tool, and emphasizes the importance of obtaining histological confirmation of malignant diseases whenever possible.

  13. False positive diagnosis of malignancy in a case of cryptogenic organising pneumonia presenting as a pulmonary mass with mediastinal nodes detected on fluorodeoxyglucose-positron emission tomography: a case report

    PubMed Central

    2009-01-01

    Introduction We report the case of a patient with positive findings on a lung emission tomography/computed tomography (PET/CT) scan, with possible contra lateral mediastinal involvement, which strongly suggested an inoperable lung carcinoma. The lung mass proved to be a cryptogenic organising pneumonia. While the latter has previously been shown to be PET/CT positive, mediastinal involvement simulating malignant spread has not been previously reported. Case presentation A 50-year-old Caucasian woman presented with a history of unproductive cough and was found to have a mass in the right upper lobe as shown on chest X-ray and a computed tomography scan. A subsequent PET/CT scan showed strong uptake in the right upper lobe (maximum standard uptake values (SUVmax) 9.6) with increased uptake in the adjacent mediastinum and contralateral mediastinal nodes. Surgical resection and mediastinoscopy revealed cryptogenic organising pneumonia, with enlarged reactive mediastinal lymph nodes. Conclusion The case illustrates the limits of PET/CT scanning as a diagnostic tool, and emphasizes the importance of obtaining histological confirmation of malignant diseases whenever possible. PMID:19946541

  14. Pure hemidystonia with basal ganglion abnormalities on positron emission tomography

    SciTech Connect

    Perlmutter, J.S.; Raichle, M.E.

    1984-03-01

    We present a patient with hemidystonia and an abnormality of the contralateral basal ganglion seen only with positron emission tomography. A 50-year-old sinistral man suffered minor trauma to the right side of his head and neck. Within 20 minutes he developed paroxysmal intermittent dystonic posturing of his right face, forearm, hand, and foot, with weaker contractions of the left foot, lasting several seconds and recurring every few minutes. Neurological findings between spells were normal. The following were also normal: electrolyte, calcium, magnesium, and arterial blood gas levels, and findings of drug screen, cerebrospinal fluid examination, electroencephalography with nasopharyngeal leads, computed tomographic scanning (initially and four weeks later), and cerebral angiography. Positron emission tomographic scanning revealed abnormalities in the left basal ganglion region, including decreased oxygen metabolism, decreased oxygen extraction, increased blood volume, and increased blood flow.

  15. 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging in a Patient with HIV (-) Kaposi Sarcoma

    PubMed Central

    Cengiz, Arzu; Şavk, Ekin; Tataroğlu, Canten; Yürekli, Yakup

    2016-01-01

    Kaposi sarcoma (KS) is a vascular neoplasm that often manifests with multiple vascular nodules on the skin and other organs. Various imaging modalities can be used to display disease extent. Herein we present a 65-year-old female patient with human immunodeficiency virus negative KS along with her whole-body positron emission tomography/computed tomography imaging findings. PMID:27751977

  16. Rare case of an ovarian vein tumor thrombosis identified on fluorodeoxyglucose positron emission tomography/computed tomography

    PubMed Central

    Chandra, Piyush; Agrawal, Archi; Purandare, Nilendu; Shah, Sneha; Rangarajan, Venkatesh

    2016-01-01

    Fludeoxyglucose positron emission tomography/computed tomography is valuable in the identification of tumor thrombus and differentiating it from bland thrombus which has implications in initiating anticoagulation. We present a rare case of tumor thrombosis in ovarian vein, in a recurrent case of uterine carcinosarcoma. PMID:27833321

  17. Preoperative [18]fluorodeoxyglucose-positron emission tomography/computed tomography in early stage breast cancer: Rates of distant metastases.

    PubMed

    Vinh-Hung, Vincent; Everaert, Hendrik; Farid, Karim; Djassemi, Navid; Baudin-Veronique, Jacqueline; Bougas, Stefanos; Michailovich, Yuriy; Joachim-Contaret, Clarisse; Cécilia-Joseph, Elsa; Verschraegen, Claire; Nguyen, Nam P

    2017-07-28

    To investigate rates of distant metastases (DM) detected with [18]fluorodeoxyglucose-positron emission tomography/computed tomography ((18)FDG-PET/CT) in early stage invasive breast cancer. We searched the English language literature databases of PubMed, EMBASE, ISI Web of Knowledge, Web of Science and Google Scholar, for publications on DM detected in patients who had (18)FDG-PET/CT scans as part of the staging for early stages of breast cancer (stage I and II), prior to or immediately following surgery. Reports published between 2011 and 2017 were considered. The systematic review was conducted according to the PRISMA guidelines. Among the 18 total studies included in the analysis, the risk of DM ranged from 0% to 8.3% and 0% to 12.9% for stage I and II invasive breast cancer, respectively. Among the patients with clinical stage II, the rate of occult metastases diagnosed by (18)FDG-PET/CT was 7.2% (range, 0%-19.6%) for stage IIA and 15.8% (range, 0%-40.8%) for stage IIB. In young patients (< 40-year-old), (18)FDG-PET/CT demonstrated a higher prevalence of DM at the time of diagnosis for those with aggressive histology (i.e., triple-negative receptors and poorly differentiated grade). Young patients with poorly differentiated tumors and stage IIB triple-negative breast cancer may benefit from (18)FDG-PET/CT at initial staging to detect occult DM prior to surgery.

  18. Clinical Utility of Positron Emission Tomography Magnetic Resonance Imaging (PET-MRI) in Gastrointestinal Cancers.

    PubMed

    Matthews, Robert; Choi, Minsig

    2016-09-09

    Anatomic imaging utilizing both CT (computed tomography) and MRI (magnetic resonance imaging) limits the assessment of cancer metastases in lymph nodes and distant organs while functional imaging like PET (positron emission tomography) scan has its limitation in spatial resolution capacity. Hybrid imaging utilizing PET-CT and PET-MRI are novel imaging modalities that are changing the current landscape in cancer diagnosis, staging, and treatment response. MRI has shown to have higher sensitivity in soft tissue, head and neck pathology, and pelvic disease, as well as, detecting small metastases in the liver and bone compared to CT. Combining MRI with PET allows for detection of metastases that may have been missed with current imaging modalities. In this review, we will examine the clinical utility of FDG PET-MRI in the diagnosis and staging of gastrointestinal cancers with focus on esophageal, stomach, colorectal, and pancreatic cancers. We will also explore its role in treatment response and future directions associated with it.

  19. Positron emission tomography: physics, instrumentation, and image analysis.

    PubMed

    Porenta, G

    1994-01-01

    Positron emission tomography (PET) is a noninvasive diagnostic technique that permits reconstruction of cross-sectional images of the human body which depict the biodistribution of PET tracer substances. A large variety of physiological PET tracers, mostly based on isotopes of carbon, nitrogen, oxygen, and fluorine is available and allows the in vivo investigation of organ perfusion, metabolic pathways and biomolecular processes in normal and diseased states. PET cameras utilize the physical characteristics of positron decay to derive quantitative measurements of tracer concentrations, a capability that has so far been elusive for conventional SPECT (single photon emission computed tomography) imaging techniques. Due to the short half lives of most PET isotopes, an on-site cyclotron and a radiochemistry unit are necessary to provide an adequate supply of PET tracers. While operating a PET center in the past was a complex procedure restricted to few academic centers with ample resources, PET technology has rapidly advanced in recent years and has entered the commercial nuclear medicine market. To date, the availability of compact cyclotrons with remote computer control, automated synthesis units for PET radiochemistry, high-performance PET cameras, and user-friendly analysis workstations permits installation of a clinical PET center within most nuclear medicine facilities. This review provides simple descriptions of important aspects concerning physics, instrumentation, and image analysis in PET imaging which should be understood by medical personnel involved in the clinical operation of a PET imaging center.

  20. Ictal onset zone and seizure propagation delineated on ictal F-18 fluorodeoxyglucose positron emission tomography/computed tomography.

    PubMed

    Tripathi, Madhavi; Tripathi, Manjari; Garg, Ajay; Damle, Nishikant; Bal, Chandrasekhar

    2016-01-01

    The present case highlights the utility of ictal F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in delineating the seizure onset zone in a child with complex partial seizures. Although F-18 FDG PET has been successfully used to delineate interictal hypometabolism, planned ictal FDG PET, in cases with prolonged seizure activity, can provide better spatial resolution than single-photon emission CT by delineating the seizure onset zone and propagation pathway.

  1. Positron Emission Tomography for the Assessment of Myocardial Viability

    PubMed Central

    2010-01-01

    waiting lists. The third option, revascularization, is used to restore the flow of blood to the heart via coronary artery bypass grafting (CABG) or through minimally invasive percutaneous coronary interventions (balloon angioplasty and stenting). Both methods, however, are associated with important perioperative risks including mortality, so it is essential to properly select patients for this procedure. Myocardial Viability Left ventricular dysfunction may be permanent if a myocardial scar is formed, or it may be reversible after revascularization. Reversible LV dysfunction occurs when the myocardium is viable but dysfunctional (reduced contractility). Since only patients with dysfunctional but viable myocardium benefit from revascularization, the identification and quantification of the extent of myocardial viability is an important part of the work-up of patients with heart failure when determining the most appropriate treatment path. Various non-invasive cardiac imaging modalities can be used to assess patients in whom determination of viability is an important clinical issue, specifically: dobutamine echocardiography (echo), stress echo with contrast, SPECT using either technetium or thallium, cardiac magnetic resonance imaging (cardiac MRI), and positron emission tomography (PET). Dobutamine Echocardiography Stress echocardiography can be used to detect viable myocardium. During the infusion of low dose dobutamine (5 – 10 μg/kg/min), an improvement of contractility in hypokinetic and akentic segments is indicative of the presence of viable myocardium. Alternatively, a low-high dose dobutamine protocol can be used in which a biphasic response characterized by improved contractile function during the low-dose infusion followed by a deterioration in contractility due to stress induced ischemia during the high dose dobutamine infusion (dobutamine dose up to 40 ug/kg/min) represents viable tissue. Newer techniques including echocardiography using contrast agents

  2. Prognostic value of rubidium-82 positron emission tomography in patients after heart transplant.

    PubMed

    Mc Ardle, Brian A; Davies, Ross A; Chen, Li; Small, Gary R; Ruddy, Terrence D; Dwivedi, Girish; Yam, Yeung; Haddad, Haissam; Mielniczuk, Lisa M; Stadnick, Ellamae; Hessian, Renee; Guo, Ann; Beanlands, Rob S; deKemp, Robert A; Chow, Benjamin J W

    2014-11-01

    Cardiac allograft vasculopathy is a key prognostic determinant after heart transplant. Detection and risk stratification of patients with cardiac allograft vasculopathy are problematic. Positron emission tomography using rubidium-82 allows quantification of absolute myocardial blood flow and may have utility for risk stratification in this population. Patients with a history of heart transplant undergoing dipyridamole rubidium-82 positron emission tomography were prospectively enrolled. Myocardial perfusion and left ventricular ejection fraction were recorded. Absolute flow quantification at rest and after dipyridamole stress as well as the ratio of mean global flow at stress and at rest, termed myocardial flow reserve, were calculated. Patients were followed for all-cause death, acute coronary syndrome, and heart failure hospitalization. A total of 140 patients (81% men; median age, 62 years; median follow-up, 18.2 months) were included. There were 14 events during follow-up (9 deaths, 1 acute coronary syndrome, and 4 heart failure admissions). In addition to baseline clinical variables (estimated glomerular filtration rate, previously documented cardiac allograft vasculopathy), relative perfusion defects, mean myocardial flow reserve, and mean stress myocardial blood flow were significant predictors of adverse outcome. Abnormalities on rubidium-82 positron emission tomography were predictors of adverse events in heart transplant patients. Larger prospective studies are required to confirm these findings. © 2014 American Heart Association, Inc.

  3. The role of single-photon emission computed tomography/computed tomography in benign and malignant bone disease.

    PubMed

    Horger, Marius; Bares, Roland

    2006-10-01

    Radiological (plain radiographs, computed tomography [CT], magnetic resonance imaging [MRI]) and nuclear medicine methods (bone scan, leukocyte scan) both provide unique information about the status of the skeleton. Both have typical strengths and weaknesses, which often lead to the sequential use of different procedures in daily routine. This use causes the unnecessary loss of time and sometimes money, if redundant information is obtained without establishing a final diagnosis. Recently, new devices for hybrid imaging (single-photon emission computed tomography/computed tomography [SPECT/CT], positron emission tomography/computed tomography [PET/CT]) were introduced, which allow for direct fusion of morphological (CT) and functional (SPECT, PET) data sets. With regard to skeletal abnormalities, this approach appears to be extremely useful because it combines the advantages of both techniques (high-resolution imaging of bone morphology and high sensitivity imaging of bone metabolism). By the accurate correlation of both, a new quality of bone imaging has now become accessible. Although researchers undertaking the initial studies exclusively used low-dose CT equipment, a new generation of SPECT/CT devices has emerged recently. By integrating high-resolution spiral CT, quality of bone imaging may improve once more. Ongoing prospective studies will have to show whether completely new diagnostic algorithms will come up for classification of bone disease as a consequence of this development. Besides, the role of ultrasonography and MRI for bone and soft-tissue imaging also will have to be re-evaluated. Looking at the final aim of all imaging techniques--to achieve correct diagnosis in a fast, noninvasive, comprehensive, and inexpensive way--we are now on the edge of a new era of multimodality imaging that will probably change the paths and structure of medicine in many ways. Presently, hybrid imaging using SPECT/CT has been proven to increase sensitivity and specificity

  4. Application of Computer Tomography for Life Detection

    NASA Technical Reports Server (NTRS)

    Tsapin, A.; Nealson, K.

    2001-01-01

    Perhaps one of the most fundamentally difficult challenges facing those who would search for life is that of scale determination. Spatial scales of life on Earth range over more than 15 orders of magnitude in mass and volume, and more than 8 orders of magnitude in 2 dimensional space. If the distribution of life is sparse in comparison to the background on which it is found, then the choice of the right scale is critical to finding that life. But how does one identify the proper scale? To put this in other words, how does one recognize the "haystacks" in which the needles (biosignatures and evidence of life) might be most profitably searched for? The problem is further exacerbated when conditions get extreme because much of the life moves from the clement surface environment into the pores and more clement environments inside of rocks, minerals and soils. Once encased in their lithic homes, these microbes become nearly impossible to study by standard techniques because of the opacity of the rocks. It is this problem that we propose to address in the work proposed here. Computer Tomography (CT) has been a very valuable tool in medicine, where the best resolution available has typically been of the order of about 0.5 mm. However, to adapt the approach for life detection of microbial endoliths, the resolution needs to be moved to the micrometer and even submicrometer levels. Thus for the studies proposed here, we begin with a commercially available instrument that can yield resolution of approximately 10 micrometers. The rational for this is twofold: first, this is the "state of the art" in laboratory instruments; and second, that while the usual size of a microbial cell is about 1 micron, microorganisms tend to live in communities that usually exceed the 10 micrometer size range. The resolution also depends on the sample size itself, so having a small lab instrument into which small samples can be placed will be beneficial to the resolution. We have now used several

  5. Application of Computer Tomography for Life Detection

    NASA Technical Reports Server (NTRS)

    Tsapin, A.; Nealson, K.

    2001-01-01

    Perhaps one of the most fundamentally difficult challenges facing those who would search for life is that of scale determination. Spatial scales of life on Earth range over more than 15 orders of magnitude in mass and volume, and more than 8 orders of magnitude in 2 dimensional space. If the distribution of life is sparse in comparison to the background on which it is found, then the choice of the right scale is critical to finding that life. But how does one identify the proper scale? To put this in other words, how does one recognize the "haystacks" in which the needles (biosignatures and evidence of life) might be most profitably searched for? The problem is further exacerbated when conditions get extreme because much of the life moves from the clement surface environment into the pores and more clement environments inside of rocks, minerals and soils. Once encased in their lithic homes, these microbes become nearly impossible to study by standard techniques because of the opacity of the rocks. It is this problem that we propose to address in the work proposed here. Computer Tomography (CT) has been a very valuable tool in medicine, where the best resolution available has typically been of the order of about 0.5 mm. However, to adapt the approach for life detection of microbial endoliths, the resolution needs to be moved to the micrometer and even submicrometer levels. Thus for the studies proposed here, we begin with a commercially available instrument that can yield resolution of approximately 10 micrometers. The rational for this is twofold: first, this is the "state of the art" in laboratory instruments; and second, that while the usual size of a microbial cell is about 1 micron, microorganisms tend to live in communities that usually exceed the 10 micrometer size range. The resolution also depends on the sample size itself, so having a small lab instrument into which small samples can be placed will be beneficial to the resolution. We have now used several

  6. Mycosis fungoides staged by 18F-flurodeoxyglucose positron emission tomography/computed tomography

    PubMed Central

    Xu, Lu; Pang, Hua; Zhu, Jin; Chen, Xi; Guan, Lili; Wang, Jie; Chen, Jing; Liu, Ying

    2016-01-01

    Abstract Introduction: Mycosis fungoides is a kind of malignant lymphoma arising from T cells, but primarily occurs in skin, and it is the most common type of cutaneous lymphoma. Mycosis fungoides (MF) is a rare non-Hodgkin lymphoma but the most common type of primary cutaneous T-cell lymphomas. Because of unknown etiology and mechanism, and lack of typical clinical and histophysiological manifestations, the final diagnosis of MF is currently dependent on pathology and immunohistochemistry. Subsequently, tumor staging is very important. Different approaches would be taken according to varying degrees of cutaneous and extracutaneous lesions. Computed tomography (CT) scan has been chosen to stage tumors customarily. However, CT could only provide morphological information and analyze lymphadenopathy by the size criteria. 18F-flurodeoxyglucose positron emission tomography/computed tomography (PET/CT) could provide morphological information and metabolic conditions simultaneously, which is helpful to locate and stage lesion. Conclusion: 18F-flurodeoxyglucose PET/CT could identify cutaneous and extracutaneous lesions in patients with MF. It could provide the range of lesions and biopsy target. PMID:27828842

  7. Is there any role of positron emission tomography computed tomography for predicting resectability of gallbladder cancer?

    PubMed

    Kim, Jaihwan; Ryu, Ji Kon; Kim, Chulhan; Paeng, Jin Chul; Kim, Yong-Tae

    2014-05-01

    The role of integrated (18)F-2-fluoro-2-deoxy-D-glucose positron emission tomography computed tomography (PET-CT) is uncertain in gallbladder cancer. The aim of this study was to show the role of PET-CT in gallbladder cancer patients. Fifty-three patients with gallbladder cancer underwent preoperative computed tomography (CT) and PET-CT scans. Their medical records were retrospectively reviewed. Twenty-six patients underwent resection. Based on the final outcomes, PET-CT was in good agreement (0.61 to 0.80) with resectability whereas CT was in acceptable agreement (0.41 to 0.60) with resectability. When the diagnostic accuracy of the predictions for resectability was calculated with the ROC curve, the accuracy of PET-CT was higher than that of CT in patients who underwent surgical resection (P=0.03), however, there was no difference with all patients (P=0.12). CT and PET-CT had a discrepancy in assessing curative resection in nine patients. These consisted of two false negative and four false positive CT results (11.3%) and three false negative PET-CT results (5.1%). PET-CT was in good agreement with the final outcomes compared to CT. As a complementary role of PEC-CT to CT, PET-CT tended to show better prediction about resectability than CT, especially due to unexpected distant metastasis.

  8. CO2BOLD assessment of moyamoya syndrome: Validation with single photon emission computed tomography and positron emission tomography imaging

    PubMed Central

    Pellaton, Alain; Bijlenga, Philippe; Bouchez, Laurie; Cuvinciuc, Victor; Barnaure, Isabelle; Garibotto, Valentina; Lövblad, Karl-Olof; Haller, Sven

    2016-01-01

    AIM To compare the assessment of cerebrovascular reserve (CVR) using CO2BOLD magnetic resonance imaging (MRI) vs positron emission tomography (PET) and single photon emission computed tomography (SPECT) as reference standard. METHODS Ten consecutive patients (8 women, mean age of 41 ± 26 years) with moyamoya syndrome underwent 14 pre-surgical evaluations for external-internal carotid artery bypass surgery. CVR was assessed using CO2BOLD and PET (4)/SPECT (11) with a maximum interval of 36 d, and evaluated by two experienced neuroradiologists. RESULTS The inter-rater agreement was 0.81 for SPECT (excellent), 0.43 for PET (fair) and 0.7 for CO2BOLD (good). In 9/14 cases, there was a correspondence between CO2BOLD and PET/SPECT. In 4/14 cases, CVR was over-estimated in CO2BOLD, while in 1/14 case, CVR was underestimated in CO2BOLD. The sensitivity of CO2BOLD was 86% and a specificity of 43%. CONCLUSION CO2BOLD can be used for pre-surgical assessment of CVR in patients with moyamoya syndrome and combines the advantages of absent irradiation, high availability of MRI and assessment of brain parenchyma, cerebral vessels and surrogate CVR in one stop. PMID:27928470

  9. Shifted helical computed tomography to optimize cardiac positron emission tomography-computed tomography coregistration: quantitative improvement and limitations.

    PubMed

    Johnson, Nils P; Pan, Tinsu; Gould, K Lance

    2010-10-01

    Positron emission tomography-computed tomography (PET-CT) uses CT attenuation correction but suffers from misregistration artifacts. However, the quantitative accuracy of helical versus cine CT in the same patient after optimized coregistration by shifting both CT data as needed for each patient is unknown. We studied 293 patients undergoing cardiac perfusion PET-CT using helical CT attenuation correction for comparison to cine CT. Objective, quantitative criteria identified perfusion abnormalities that were associated visually with PET-CT misregistration. Custom software shifted CT data to optimize coregistration with quantitative artifact improvement. The majority (58.1%) of cases with both helical and shifted helical CT data (n  = 93) had artifacts that improved or resolved by software shifting helical CT data. Translation of shifted helical CT was greatest in the x-direction (8.8 ± 3.3 mm) and less in the y- and z-directions (approximately 3.5 mm). The magnitude of differences in quantitative end points was greatest for helical (p  =  .0001, n  =  177 studies), less for shifted helical but significant (p  =  .0001, n  =  93 studies), and least for cine (not significant, n  =  161 studies) CT compared to optimal attenuation correction for each patient. Frequent artifacts owing to attenuation-emission misregistration are substantially corrected by software shifting helical CT scans to achieve proper coregistration that, however, remains on average significantly inferior to cine CT attenuation quantitatively.

  10. Ocular Granulocytic Sarcoma as an Initial Clinical Presentation of Acute Myeloid Leukemia Identified on Flurodeoxyglucose Positron Emission Tomography/Computed Tomography

    PubMed Central

    Chandra, Piyush; Purandare, Nilendu; Shah, Sneha; Agrawal, Archi; Rangarajan, Venkatesh

    2017-01-01

    Granulocytic sarcoma (GS) or chloroma, rare extramedullary manifestation of acute myeloid leukemia and not infrequently, can be presenting clinical feature. Multiple studies have demonstrated the clinical utility of fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in early detection and follow-up assessment of GS after chemotherapy. Commonly involved areas include bones, lymph nodes, breasts, and skin and not uncommonly, the disease can be multifocal. We present a rare case of ocular GS, where FDG-PET/CT in addition to the identifying the ocular mass, revealed multiple clinically occult extramedullary lesions. PMID:28242990

  11. F18-fluorodeoxyglucose-positron emission tomography and computed tomography is not accurate in preoperative staging of gastric cancer

    PubMed Central

    Ha, Tae Kyung; Choi, Yun Young; Song, Soon Young

    2011-01-01

    Purpose To investigate the clinical benefits of F18-fluorodeoxyglucose-positron emission tomography and computed tomography (18F-FDG-PET/CT) over multi-detector row CT (MDCT) in preoperative staging of gastric cancer. Methods FDG-PET/CT and MDCT were performed on 78 patients with gastric cancer pathologically diagnosed by endoscopy. The accuracy of radiologic staging retrospectively was compared to pathologic result after curative resection. Results Primary tumors were detected in 51 (65.4%) patients with 18F-FDG-PET/CT, and 47 (60.3%) patients with MDCT. Regarding detection of lymph node metastasis, the sensitivity of FDG-PET/CT was 51.5% with an accuracy of 71.8%, whereas those of MDCT were 69.7% and 69.2%, respectively. The sensitivity of 18F-FDG-PET/CT for a primary tumor with signet ring cell carcinoma was lower than that of 18F-FDG-PET/CT for a primary tumor with non-signet ring cell carcinoma (35.3% vs. 73.8%, P < 0.01). Conclusion Due to its low sensitivity, 18F-FDG-PET/CT alone shows no definite clinical benefit for prediction of lymph node metastasis in preoperative staging of gastric cancer. PMID:22066108

  12. Simulation study of respiratory-induced errors in cardiac positron emission tomography/computed tomography

    SciTech Connect

    Fitzpatrick, Gianna M.; Wells, R. Glenn

    2006-08-15

    Heart disease is a leading killer in Canada and positron emission tomography (PET) provides clinicians with in vivo metabolic information for diagnosing heart disease. Transmission data are usually acquired with {sup 68}Ge, although the advent of PET/CT scanners has made computed tomography (CT) an alternative option. The fast data acquisition of CT compared to PET may cause potential misregistration problems, leading to inaccurate attenuation correction (AC). Using Monte Carlo simulations and an anthropomorphic dynamic computer phantom, this study determines the magnitude and location of respiratory-induced errors in radioactivity uptake measured in cardiac PET/CT. A homogeneous tracer distribution in the heart was considered. The AC was based on (1) a time-averaged attenuation map (2) CT maps from a single phase of the respiratory cycle, and (3) CT maps phase matched to the emission data. Circumferential profiles of the heart uptake were compared and differences of up to 24% were found between the single-phase CT-AC method and the true phantom values. Simulation results were supported by a PET/CT canine study which showed differences of up to 10% in the heart uptake in the lung-heart boundary region when comparing {sup 68}Ge- to CT-based AC with the CT map acquired at end inhalation.

  13. Single-photon emission computed tomography/computed tomography in brain tumors.

    PubMed

    Schillaci, Orazio; Filippi, Luca; Manni, Carlo; Santoni, Riccardo

    2007-01-01

    Anatomic imaging procedures (computed tomography [CT] and magnetic resonance imaging [MRI]) have become essential tools for brain tumor assessment. Functional images (positron emission tomography [PET] and single-photon emission computed tomography [SPECT]) can provide additional information useful during the diagnostic workup to determine the degree of malignancy and as a substitute or guide for biopsy. After surgery and/or radiotherapy, nuclear medicine examinations are essential to assess persistence of tumor, to differentiate recurrence from radiation necrosis and gliosis, and to monitor the disease. The combination of functional images with anatomic ones is of the utmost importance for a full evaluation of these patients, which can be obtained by means of imaging fusion. Despite the fast-growing diffusion of PET, in most cases of brain tumors, SPECT studies are adequate and provide results that parallel those obtained with PET. The main limitation of SPECT imaging with brain tumor-seeking radiopharmaceuticals is the lack of precise anatomic details; this drawback is overcome by the fusion with morphological studies that provide an anatomic map to scintigraphic data. In the past, software-based fusion of independently performed SPECT and CT or MRI demonstrated usefulness for brain tumor assessment, but this process is often time consuming and not practical for everyday nuclear medicine studies. The recent development of dual-modality integrated imaging systems, which allow the acquisition of SPECT and CT images in the same scanning session, and their co-registration by means of the hardware, has facilitated this process. In SPECT studies of brain tumors with various radiopharmaceuticals, fused images are helpful in providing the precise localization of neoplastic lesions, and in excluding the disease in sites of physiologic tracer uptake. This information is useful for optimizing diagnosis, therapy monitoring, and radiotherapy treatment planning, with a

  14. Studies of the brain cannabinoid system using positron emission tomography

    SciTech Connect

    Gatley, S.J.; Volkow, N.D.

    1995-10-01

    Studies using radiolabeled psychoactive drugs in conjunction with positron emission tomography (PET) have permitted the imaging of binding sites in the human brain. Similar studies of marijuana have been hampered by the unsuitability of radiolabeled THC for PET studies, and the current unavailability of other in vivo imaging agents for cannabinoid receptors. Recent developments in medicinal chemistry suggest that a PET radiotracer for cannabinoid receptors will soon become available. This chapter briefly reviews these developments, together with the results of PET studies of the effects of marijuana and other abused drugs on brain metabolism. It also reviews PET studies of cocaine binding sites, to demonstrate the kind of investigations that will be possible when a cannabinoid receptor PET radioligand becomes available.

  15. Cerebral blood flow and personality: a positron emission tomography study.

    PubMed

    Johnson, D L; Wiebe, J S; Gold, S M; Andreasen, N C; Hichwa, R D; Watkins, G L; Boles Ponto, L L

    1999-02-01

    This study sought to describe brain regions associated with the personality dimension of introversion/extraversion. Measures of cerebral blood flow (CBF) were obtained from 18 healthy subjects by means of [150]H20 positron emission tomography. Correlations of regional CBF with introversion/extraversion were calculated, and a three-dimensional map of those correlations was generated. Overall, introversion was associated with increased blood flow in the frontal lobes and in the anterior thalamus. Regions in the anterior cingulate gyrus, the temporal lobes, and the posterior thalamus were found to be correlated with extraversion. The findings of the study lend support to the notion that introversion is associated with increased activity in frontal lobe regions. Moreover, the study suggests that individual differences in introversion and extraversion are related to differences in a fronto-striato-thalamic circuit.

  16. Differential diagnosis of depression: relevance of positron emission tomography

    SciTech Connect

    Schwartz, J.M.; Baxter, L.R. Jr.; Mazziotta, J.C.; Gerner, R.H.; Phelps, M.E.

    1987-09-11

    The proper differential diagnosis of depression is important. A large body of research supports the division of depressive illness into bipolar and unipolar subtypes with respect to demographics, genetics, treatment response, and neurochemical mechanisms. Optimal treatment is different for unipolar and bipolar depressions. Treating a patient with bipolar depression as one would a unipolar patient may precipitate a serious manic episode or possibly even permanent rapid cycling disorder. The clinical distinction between these disorders, while sometimes difficult, can often be achieved through an increased diagnostic suspicion concerning a personal or family history of mania. Positron emission tomography and the FDG method, which allow in vivo study of the glucose metabolic rates for discrete cerebral structures, provide new evidence that bipolar and unipolar depression are two different disorders.

  17. Current good manufacturing practice for positron emission tomography drugs.

    PubMed

    2009-12-10

    The Food and Drug Administration (FDA) is issuing regulations on current good manufacturing practice (CGMP) for positron emission tomography (PET) drugs. The regulations are intended to ensure that PET drugs meet the requirements of the Federal Food, Drug, and Cosmetic Act (the act) regarding safety, identity, strength, quality, and purity. In this final rule, we are establishing CGMP regulations for approved PET drugs. For investigational and research PET drugs, the final rule states that the requirement to follow CGMP may be met by complying with these regulations or by producing PET drugs in accordance with the United States Pharmacopeia (USP) general chapter on compounding PET radiopharmaceuticals. We are establishing these CGMP requirements for PET drugs under the provisions of the Food and Drug Administration Modernization Act of 1997 (the Modernization Act). Elsewhere in this issue of the Federal Register, we are announcing the availability of a guidance entitled "PET Drugs--Current Good Manufacturing Practice (CGMP)."

  18. Respiratory motion correction in emission tomography image reconstruction.

    PubMed

    Reyes, Mauricio; Malandain, Grégoire; Koulibaly, Pierre Malick; González Ballester, Miguel A; Darcourt, Jacques

    2005-01-01

    In Emission Tomography imaging, respiratory motion causes artifacts in lungs and cardiac reconstructed images, which lead to misinterpretations and imprecise diagnosis. Solutions like respiratory gating, correlated dynamic PET techniques, list-mode data based techniques and others have been tested with improvements over the spatial activity distribution in lungs lesions, but with the disadvantages of requiring additional instrumentation or discarding part of the projection data used for reconstruction. The objective of this study is to incorporate respiratory motion correction directly into the image reconstruction process, without any additional acquisition protocol consideration. To this end, we propose an extension to the Maximum Likelihood Expectation Maximization (MLEM) algorithm that includes a respiratory motion model, which takes into account the displacements and volume deformations produced by the respiratory motion during the data acquisition process. We present results from synthetic simulations incorporating real respiratory motion as well as from phantom and patient data.

  19. Wilson's disease studied with FDG and positron emission tomography

    SciTech Connect

    Hawkins, R.A.; Mazziotta, J.C.; Phelps, M.E.

    1987-11-01

    Four patients with Wilson's disease and eight normal controls were studied with 2-deoxy-2-(/sup 18/F)fluoro-D-glucose (FDG) and positron emission tomography (PET). The patients had diffusely reduced glucose metabolism in all brain regions evaluated compared with controls, with the exception of the thalamus. The ratio of the cerebral metabolic rate for glucose in the lenticular nuclei to hemispheres declined from 1.23 (+/- 0.14 SD) in controls to 1.03 (+/- 0.06) (p less than 0.025) in Wilson's disease patients. Compared with Huntington's disease, the PET FDG results in Wilson's disease indicate relatively less focal involvement of the caudate nucleus, more severe focal changes in the lenticular nuclei, and more significant global changes in glucose metabolism.

  20. Positron emission tomography in CNS drug discovery and drug monitoring.

    PubMed

    Piel, Markus; Vernaleken, Ingo; Rösch, Frank

    2014-11-26

    Molecular imaging methods such as positron emission tomography (PET) are increasingly involved in the development of new drugs. Using radioactive tracers as imaging probes, PET allows the determination of the pharmacokinetic and pharmacodynamic properties of a drug candidate, via recording target engagement, the pattern of distribution, and metabolism. Because of the noninvasive nature and quantitative end point obtainable by molecular imaging, it seems inherently suited for the examination of a pharmaceutical's behavior in the brain. Molecular imaging, most especially PET, can therefore be a valuable tool in CNS drug research. In this Perspective, we present the basic principles of PET, the importance of appropriate tracer selection, the impact of improved radiopharmaceutical chemistry in radiotracer development, and the different roles that PET can fulfill in CNS drug research.

  1. Microdosing studies in humans: the role of positron emission tomography.

    PubMed

    Bauer, Martin; Wagner, Claudia Christina; Langer, Oliver

    2008-01-01

    Positron emission tomography (PET)-microdosing comprises the administration of a carbon-11- or fluorine-18-labelled drug candidate to human subjects in order to describe the drug's concentration-time profile in body tissues targeted for treatment. As PET microdosing involves the administration of only microgram amounts of unlabelled drug, the potential toxicological risk to human subjects is very limited. Consequently, regulatory authorities require reduced preclinical safety testing as compared with conventional phase 1 studies. Microdose studies are gaining increasing importance in clinical drug research as they have the potential to shorten time-lines and cut costs along the critical path of drug development. Current applications of PET in anticancer, anti-infective and CNS system drug research are reviewed.

  2. (68)Ga-labeled radiopharmaceuticals for positron emission tomography.

    PubMed

    Shetty, Dinesh; Lee, Yun-Sang; Jeong, Jae Min

    2010-12-01

    (68)Ga is a promising emerging radionuclide for positron emission tomography (PET). It is produced using a (68)Ge/(68)Ga-generator, and thus, would enable the cyclotron-independent distribution of PET. However, new (68)Ga-labeled radiopharmaceuticals that can replace (18)F-labeled agents like [(18)F]fluorodeoxyglucose (FDG) are needed. Most of the (68)Ga-labeled derivatives currently used are peptide agents, but the developments of other agents, such as amino acid derivatives, nitroimidazole derivatives, and glycosylated human serum albumin, are being actively pursued in many laboratories. Thus, appearance of new (68)Ga-labeled radiopharmaceuticals with high impact are expected in the near future. Here, we present an overview of (68)Ga-labeled agents in terms of their clinical significances and relevances to the management of certain tumors, and pertinent pre-clinical developments.

  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. The investigation of Alzheimer's disease with single photon emission tomography.

    PubMed Central

    Burns, A; Philpot, M P; Costa, D C; Ell, P J; Levy, R

    1989-01-01

    Twenty patients satisfying standard clinical criteria for Alzheimer's disease (AD) and six age-matched normal controls were studied using 99mTc hexamethyl-propyleneamine oxime and single photon emission tomography. The AD patients had lower regional cerebral blood flow (rCBF) in the temporal and posterior parietal lobes compared to controls. AD patients with apraxia and aphasia had lower rCBF in the lateral temporal and posterior parietal lobes than AD patients without these features. Within the AD group, correlations were found between neuropsychological tests and rCBF: praxis correlated with posterior parietal activity, memory with left temporal lobe activity and language with activity throughout the left hemisphere. Images PMID:2467967

  5. Chelators for copper radionuclides in positron emission tomography radiopharmaceuticals.

    PubMed

    Cai, Zhengxin; Anderson, Carolyn J

    2014-04-01

    The development of chelating agents for copper radionuclides in positron emission tomography radiopharmaceuticals has been a highly active and important area of study in recent years. The rapid evolution of chelators has resulted in highly specific copper chelators that can be readily conjugated to biomolecules and efficiently radiolabeled to form stable complexes in vivo. Chelators are not only designed for conjugation to monovalent biomolecules but also for incorporation into multivalent targeting ligands such as theranostic nanoparticles. These advancements have strengthened the role of copper radionuclides in the fields of nuclear medicine and molecular imaging. This review emphasizes developments of new copper chelators that have most greatly advanced the field of copper-based radiopharmaceuticals over the past 5 years. © 2013 The Authors. J. Label Compd. Radiopharm published by John Wiley & Sons Ltd.

  6. FDG positron emission computed tomography in a study of aphasia

    SciTech Connect

    Metter, E.J.; Wasterlain, C.G.; Kuhl, D.E.; Hanson, W.R.; Phelps, M.E.

    1981-08-01

    Positron emission computed tomography (PECT) using 18F-2-fluoro-2-deoxy-D-glucose (FDG) was used to investigate the correlations between clinical status, anatomy (as described by CT), and metabolism in five patients with stable aphasia resulting from ischemic cerebral infarction. Local cerebral metabolic activity was diminished in an area larger than the area of infarction demonstrated by CT. In one patient, FDG PECT revealed a metabolic lesion that probably caused the aphasic syndrome and was not apparent by CT. The data suggest that reliance on CT in delineating the extent of the brain lesion in aphasia or other neuropsychological defects can be misleading; FDG PECT may provide important additional information. Two patients with similar metabolic lesions had very different clinical syndromes, showing that even when currently available methods are combined, major gaps remain in clinicoanatomical correlations in aphasia.

  7. Temporoparietal cortex in aphasia. Evidence from positron emission tomography

    SciTech Connect

    Metter, E.J.; Hanson, W.R.; Jackson, C.A.; Kempler, D.; van Lancker, D.; Mazziotta, J.C.; Phelps, M.E. )

    1990-11-01

    Forty-four aphasic patients were examined with (F18)-fluorodeoxyglucose positron emission tomography in a resting state to determine whether consistent glucose metabolic abnormalities were present. Ninety-seven percent of subjects showed metabolic abnormalities in the angular gyrus, 89% in the supramarginal gyrus, and 87% in the lateral and transverse superior temporal gyrus. Pearson product moment correlations were calculated between regional metabolic measures and performance on the Western Aphasia Battery. No significant correlations were found between the Western Aphasia Battery scores and right hemisphere metabolic measures. Most left hemisphere regions correlated with more than one score from the Western Aphasia Battery. Temporal but not frontal regions had significant correlations to the comprehension score. The left temporoparietal region was consistently affected in these subjects, suggesting that common features in the aphasias were caused by left temporoparietal dysfunction, while behavioral differences resulted from (1) the extent of temporoparietal changes, and (2) dysfunction elsewhere in the brain, particularly the left frontal and subcortical areas.

  8. Translational neuroimaging: positron emission tomography studies of monoamine oxidase.

    PubMed

    Fowler, Joanna S; Logan, Jean; Volkow, Nora D; Wang, Gene-Jack

    2005-01-01

    Positron emission tomography (PET) using radiotracers with high molecular specificity is an important scientific tool in studies of monoamine oxidase (MAO), an important enzyme in the regulation of the neurotransmitters dopamine, norepinephrine, and serotonin as well as the dietary amine, tyramine. MAO occurs in two different subtypes, MAO A and MAO B, which have different substrate and inhibitor specificity and which are different gene products. The highly variable subtype distribution with different species makes human studies of special value. MAO A and B can be imaged in the human brain and certain peripheral organs using PET and carbon-11 (half-life 20.4 minutes) labeled mechanism-based irreversible inhibitors, clorgyline and L -deprenyl, respectively. In this article we introduce MAO and describe the development of these radiotracers and their translation from preclinical studies to the investigation of variables affecting MAO in the human brain and peripheral organs.

  9. Tau Positron Emission Tomography (PET) Imaging: Past, Present, and Future.

    PubMed

    Ariza, Manuela; Kolb, Hartmuth C; Moechars, Dieder; Rombouts, Frederik; Andrés, José Ignacio

    2015-06-11

    Alzheimer's disease (AD) is a chronic neurodegenerative disorder and the most common cause of dementia among the elderly population. The good correlation of the density and neocortical spread of neurofibrillary tangles (NFTs) with clinical AD disease progression offers an opportunity for the early diagnosis and staging using a noninvasive imaging technique such as positron emission tomography (PET). Thus, PET imaging of NFTs not only holds promise as a diagnostic tool but also may enable the development of disease modifying therapeutics for AD. In this review, we focus on the structural diversity of tau PET tracers, the challenges related to the identification of high affinity and highly selective NFT ligands, and recent progress in the clinical development of tau PET radioligands.

  10. Positron emission tomography as a diagnostic tool in oncology.

    PubMed

    Schiepers, C; Hoh, C K

    1998-01-01

    Early diagnosis in oncology is important for treatment by surgical intervention, which generally has the highest curative potential. For higher stages of disease involvement, initiation of rapid treatment is indicated to provide the patient with the optimal therapy regimen. Although this may not improve the prognosis, it will maintain the quality of life. Anatomic imaging modalities, such as CT, MR imaging, and US, are clinically important high-resolution imaging techniques that are well suited to reveal structural abnormalities. However, the differentiation of lesions as being benign or malignant is still problematic. Metabolic imaging modalities in nuclear medicine (NM), i.e., single photon emission computed tomography (SPECT) and positron emission tomography (PET), can reveal biochemical parameters of the lesions such as glucose, oxygen, or amino acid metabolism, or measure the receptor density status. These parameters may allow a completely new clinical perspective in the management and understanding of diseases such as cancer. Although PET has been around since the early 1960s, it has only recently emerged as a powerful diagnostic tool in oncology. Society has great difficulty accepting this clinical imaging modality because of its high cost and complexity. Current applications of PET in oncology have been in characterizing lesions, differentiating recurrent disease from treatment effects, staging tumors, evaluating the extent of disease, and therapy monitoring. Here, the role of PET in diagnosis, staging, and restaging of cancer is reviewed and compared with the other tumor imaging modalities. We cover articles published in the past 3 years. We utilize the typical radiology format, in which the contribution in each body area is reviewed (topographic orientation), instead of the more organ-based approach used in internal medicine.

  11. Integrated telemedicine applications and services for oncological positron emission tomography.

    PubMed

    Kontaxakis, George; Visvikis, Dimitris; Ohl, Roland; Sachpazidis, Ilias; Suarez, Juan Pablo; Selby, Peter; Cheze-Le Rest, Catherine; Santos, Andres; Ortega, Fernando; Diaz, Javier; Pan, Leyun; Strauss, Ludwig; Dimitrakopoulou-Strauss, Antonia; Sakas, Georgios; Pozo, Miguel Angel

    2006-01-01

    TENPET (Trans European Network for Positron Emission Tomography) aims to evaluate the provision of integrated teleconsultation and intelligent computer supported cooperative work services for clinical positron emission tomography (PET) in Europe at its current stage, as it is a multi-centre project financially supported by the European Commission (Information Society, eTEN Program). It addresses technological challenges by linking PET centres and developing supporting services that permit remote consultation between professionals in the field. The technological platform (CE-marked) runs on Win2000/NT/XP systems and incorporates advanced techniques for image visualization, analysis and fusion, as well as for interactive communication and message handling for off-line communications. Four PET Centres from Spain, France and Germany participate to the pilot system trials. The performance evaluation of the system is carried out via log files and user-filled questionnaires on the frequency of the teleconsultations, their duration and efficacy, quality of the images received, user satisfaction, as well as on privacy, ethical and security issues. TENPET promotes the co-operation and improved communication between PET practitioners that are miles away from their peers or on mobile units, offering options for second opinion and training and permitting physicians to remotely consult patient data if they are away from their centre. It is expected that TENPET will have a significant impact in the development of new skills by PET professionals and will support the establishment of peripheral PET units. To our knowledge, TENPET is the first telemedicine service specifically designed for oncological PET. This report presents the technical innovations incorporated in the TENPET platform and the initial pilot studies at real and diverse clinical environments in the field of oncology.

  12. Two Cases of Legionella pneumophila Pneumonia with Prolonged Neurologic Symptoms and Brain Hypoperfusion on Single-Photon Emission Computed Tomography

    PubMed Central

    Miura, You; Seto, Akira; Kanazawa, Minoru; Nagata, Makoto

    2016-01-01

    Cerebral and cerebellar symptoms are frequently associated with Legionnaires' disease. However, corresponding brain lesions are difficult to demonstrate using either computed tomography (CT) or magnetic resonance imaging (MRI). We report here two patients with Legionella pneumophila pneumonia accompanied by prolonged neurologic symptoms. In contrast to brain CT and MRI, which failed to detect any abnormalities, single-photon emission computed tomography (SPECT) showed multiple sites of hypoperfusion within the brains of both patients. These cases suggest that vasculopathy, which is detectable by SPECT, might be one of the causes of neurologic symptoms in patients with Legionnaires' disease. PMID:27478660

  13. Tc99m HM-PAO single photon emission computed tomography in temporal lobe epilepsy.

    PubMed

    Duncan, R; Patterson, J; Hadley, D M; Wyper, D J; McGeorge, A P; Bone, I

    1990-04-01

    We present the results of single photon emission computed tomography (SPECT) in 40 patients with temporal lobe epilepsy and normal computed transmission tomography (CT). Abnormalities of regional cerebral blood flow were found in 26 patients. There was focal hypoperfusion alone in 14, focal hyperperfusion alone in 6, and both types of abnormality in 6. In 4 patients there were bilateral abnormalities. Repeat SPECT showed persistence of interictal hyperperfusion in 5/12 patients. There were no significant correlations between SPECT findings and clinical parameters, and no relation between the persistence of interictal hyperperfusion and time since last seizure or seizure frequency. Where SPECT and multiple surface EEG recordings were both lateralising, agreement between them was good. The results of this study support the usefulness of HMPAO SPECT in detecting lateralising abnormalities in temporal lobe epilepsy. Interictal hyperperfusion may be commoner than previous publications suggest, and may be persistent in some cases.

  14. Positron emission tomography in minor ischemic stroke using oxygen-15 steady-state technique

    SciTech Connect

    Pozzilli, C.; Itoh, M.; Matsuzawa, T.; Fukuda, H.; Abe, Y.; Sato, T.; Takeda, S.; Ido, T.

    1987-04-01

    A study with positron emission tomography (PET) was performed on 10 patients with ischemic stroke and mild disability. The patients underwent cerebral angiography, x-ray computed tomography (CT) scan and regional cerebral measurements of CBF, CMRO2, oxygen extraction ratio (OER), and cerebral blood volume (CBV). Only minor arterial involvement was detected by angiography. In all patients, PET images of functional defects were more extensive than the corresponding CT hypodensity, and there were statistically significant reductions in CBF, CMRO2, and CBF/CBV ratio as compared with control subjects. Half of the regions analyzed in the affected hemisphere demonstrated a disruption of the normal coupling between CBF and CMRO2 as reflected by OER values significantly higher or lower than those of the corresponding region of the contralateral hemisphere. The pathophysiological pattern of high OER combined with a reduction in CBF proportionally greater than the reduction in CMRO2 was particularly indicative of regional chronic hemodynamic compromise in these patients.

  15. Utility of positron emission tomography/CT in the evaluation of small bowel pathology.

    PubMed

    Cronin, C G; Scott, J; Kambadakone, A; Catalano, O A; Sahani, D; Blake, M A; McDermott, S

    2012-09-01

    We describe the management principles and different roles of positron emission tomography (PET)/CT in the evaluation of patients with small bowel tumours (adenocarcinoma, gastrointestinal stromal tumour, lymphoma, metastases) from initial staging, monitoring response to treatment, to detection of recurrent disease. We also discuss the various non-malignant aetiologies of small bowel fludeoxyglucose (FDG) PET uptake, and other pitfalls in FDG PET/CT interpretation. Awareness of the imaging appearances of small bowel tumours, patterns of disease spread and potential PET/CT interpretation pitfalls are of paramount importance to optimise diagnostic accuracy.

  16. Painful spondylolysis or spondylolisthesis studied by radiography and single-photon emission computed tomography

    SciTech Connect

    Collier, B.D.; Johnson, R.P.; Carrera, G.F.; Meyer, G.A.; Schwab, J.P.; Flatley, T.J.; Isitman, A.T.; Hellman, R.S.; Zielonka, J.S.; Knobel, J.

    1985-01-01

    Planar bone scintigraphy (PBS) and single-photon emission computed tomography (SPECT) were compared in 19 adults with radiographic evidence of spondylolysis and/or spondylolisthesis. SPECT was more sensitive than PBS when used to identify symptomatic patients and sites of painful defects in the pars interarticularis. In addition, SPECT allowed more accurate localization than PBS. In 6 patients, spondylolysis or spondylolisthesis was unrealted to low back pain, and SPECT images of the posterior neural arch were normal. The authors conclude that when spondylolysis or spondylolisthesis is the cause of low back pain, pars defects are frequently heralded by increased scintigraphic activity which is best detected and localized by SPECT.

  17. Current status and future needs for standards of radionuclides used in positron emission tomography.

    PubMed

    Zimmerman, B E

    2013-06-01

    Positron Emission Tomography (PET) is being increasingly used as a quantitative technique for detecting disease and monitoring patient progress during treatment. To ensure the validity of the quantitative information derived from the imaging data, it is imperative that all radioactivity measurements that are part of the imaging procedure be traceable to national or international standards. This paper reviews the current status of standards for positron emitting radionuclides (e.g., (18)F, (68)Ge/(68)Ga, and (124)I) and suggests needs for future work.

  18. Advantages and disadvantages of F-18 fluorodeoxyglucose positron emission tomography/computed tomography in carcinoma of unknown primary.

    PubMed

    Yu, Xiaozhou; Li, Xiaofeng; Song, Xiuyu; Dai, Dong; Zhu, Lei; Zhu, Yanjia; Wang, Jian; Zhao, Huiqin; Xu, Wengui

    2016-11-01

    Carcinoma of unknown primary is a type of malignant disease where the primary carcinoma cannot be identified by conventional examination, which presents challenges in diagnosis and therapy. This study aims to evaluate the detailed clinical value and indications of using fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in a large sample. A total of 449 patients who were selected under strict standards were retrospectively included in this study. F-18 FDG PET/CT accurately detected the primary carcinoma in 115 of 449 patients whose primaries could not be detected by conventional examination (25.6%), with additional 27 false-positive patients. The most common primary site was the lung (34.8%). In addition, except for in metastatic melanoma (1/19, 5.3%) and axillary metastasis patients (2/49, 4.1%), F-18 FDG PET/CT had a comparative performance in detecting primary carcinoma in other pathological types and anatomical locations. The scan is able to guide treatment strategy modifications to some extent (130/449, 29.0%). We strongly recommend the use of F-18 FDG PET/CT in the early phase of examination. It is also recommended as a supplementary radiological method, and certain patients may benefit from its application in cases where regular examination is inconclusive. However, in metastatic melanoma or axillary metastasis patients where the primary site cannot be identified by routine examination, regular application of F-18 FDG PET/CT for the sole purpose of detecting the primary carcinoma should not be encouraged.

  19. Advantages and disadvantages of F-18 fluorodeoxyglucose positron emission tomography/computed tomography in carcinoma of unknown primary

    PubMed Central

    Yu, Xiaozhou; Li, Xiaofeng; Song, Xiuyu; Dai, Dong; Zhu, Lei; Zhu, Yanjia; Wang, Jian; Zhao, Huiqin; Xu, Wengui

    2016-01-01

    Carcinoma of unknown primary is a type of malignant disease where the primary carcinoma cannot be identified by conventional examination, which presents challenges in diagnosis and therapy. This study aims to evaluate the detailed clinical value and indications of using fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in a large sample. A total of 449 patients who were selected under strict standards were retrospectively included in this study. F-18 FDG PET/CT accurately detected the primary carcinoma in 115 of 449 patients whose primaries could not be detected by conventional examination (25.6%), with additional 27 false-positive patients. The most common primary site was the lung (34.8%). In addition, except for in metastatic melanoma (1/19, 5.3%) and axillary metastasis patients (2/49, 4.1%), F-18 FDG PET/CT had a comparative performance in detecting primary carcinoma in other pathological types and anatomical locations. The scan is able to guide treatment strategy modifications to some extent (130/449, 29.0%). We strongly recommend the use of F-18 FDG PET/CT in the early phase of examination. It is also recommended as a supplementary radiological method, and certain patients may benefit from its application in cases where regular examination is inconclusive. However, in metastatic melanoma or axillary metastasis patients where the primary site cannot be identified by routine examination, regular application of F-18 FDG PET/CT for the sole purpose of detecting the primary carcinoma should not be encouraged. PMID:27895731

  20. Disseminated metastatic penile squamous cell carcinoma detected by fluorodeoxyglucose PET/computerized tomography

    PubMed Central

    Kaya, Zubeyde Rana; Sager, Sait; Halac, Metin; Sonmezoglu, Kerim

    2012-01-01

    Penile cancer is an uncommon malignancy which of the management depends on the clinical stage and location of the lesion. Positron emission tomography/computerized tomography (PET/CT) is a promising method for detection of distant metastatic lesions and therapeutic strategy planning. Here, we report a case of penile squamous cell carcinoma of 57-year-old male patient, was referred to PET/CT department for investigation of metastases. There were significantly increased fluoro-18 fluorodeoxyglucose activities in supradiaphragmatic and infradiaphragmatic lymphatic stations. PMID:23919076

  1. [Positron emission tomography combined with computed tomography in the initial evaluation and response assessment in primary central nervous system lymphoma].

    PubMed

    Mercadal, Santiago; Cortés-Romera, Montserrat; Vélez, Patricia; Climent, Fina; Gámez, Cristina; González-Barca, Eva

    2015-06-08

    To evaluate the role of positron emission tomography combined with computed tomography (PET-CT) in the initial evaluation and response assessment in primary central nervous system lymphoma (PCNSL). Fourteen patients (8 males) with a median age 59.5 years diagnosed of PCNSL. A brain PET-CT and magnetic resonance imaging (MRI) were performed in the initial evaluation. In 7 patients a PET-CT after treatment was performed. PET-CT showed at diagnosis 31 hypermetabolic focuses and MRI showed 47 lesions, with a good grade of concordance between both (k = 0.61; P = .005). In the response assessment, correlation between both techniques was good, and PET-CT was helpful in the appreciation of residual MRI lesions. Overall survival at 2 years of negative vs. positive PET-CT at the end of treatment was 100 vs. 37.5%, respectively (P = .045). PET-CT can be useful in the initial evaluation of PCNSL, and especially in the assessment of response. Despite the fact that PET-CT detects less small lesions than MRI, a good correlation between MRI and PET-CT was observed. It is effective in the evaluation of residual lesions. Prospective studies are needed to confirm their possible prognostic value. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  2. Application of positron emission tomography/computed tomography in radiation treatment planning for head and neck cancers.

    PubMed

    Awan, Musaddiq J; Siddiqui, Farzan; Schwartz, David; Yuan, Jiankui; Machtay, Mitchell; Yao, Min

    2015-11-28

    18-fluorodeoxygluocose positron emission tomography/computed tomography ((18)FDG-PET/CT) provides significant information in multiple settings in the management of head and neck cancers (HNC). This article seeks to define the additional benefit of PET/CT as related to radiation treatment planning for squamous cell carcinomas (SCCs) of the head and neck through a review of relevant literature. By helping further define both primary and nodal volumes, radiation treatment planning can be improved using PET/CT. Special attention is paid to the independent benefit of PET/CT in targeting mucosal primaries as well as in detecting nodal metastases. The utility of PET/CT is also explored for treatment planning in the setting of SCC of unknown primary as PET/CT may help define a mucosal target volume by guiding biopsies for examination under anesthesia thus changing the treatment paradigm and limiting the extent of therapy. Implications of the use of PET/CT for proper target delineation in patients with artifact from dental procedures are discussed and the impact of dental artifact on CT-based PET attenuation correction is assessed. Finally, comment is made upon the role of PET/CT in the high-risk post-operative setting, particularly in the context of radiation dose escalation. Real case examples are used in these settings to elucidate the practical benefits of PET/CT as related to radiation treatment planning in HNCs.

  3. Application of positron emission tomography/computed tomography in radiation treatment planning for head and neck cancers

    PubMed Central

    Awan, Musaddiq J; Siddiqui, Farzan; Schwartz, David; Yuan, Jiankui; Machtay, Mitchell; Yao, Min

    2015-01-01

    18-fluorodeoxygluocose positron emission tomography/computed tomography (18FDG-PET/CT) provides significant information in multiple settings in the management of head and neck cancers (HNC). This article seeks to define the additional benefit of PET/CT as related to radiation treatment planning for squamous cell carcinomas (SCCs) of the head and neck through a review of relevant literature. By helping further define both primary and nodal volumes, radiation treatment planning can be improved using PET/CT. Special attention is paid to the independent benefit of PET/CT in targeting mucosal primaries as well as in detecting nodal metastases. The utility of PET/CT is also explored for treatment planning in the setting of SCC of unknown primary as PET/CT may help define a mucosal target volume by guiding biopsies for examination under anesthesia thus changing the treatment paradigm and limiting the extent of therapy. Implications of the use of PET/CT for proper target delineation in patients with artifact from dental procedures are discussed and the impact of dental artifact on CT-based PET attenuation correction is assessed. Finally, comment is made upon the role of PET/CT in the high-risk post-operative setting, particularly in the context of radiation dose escalation. Real case examples are used in these settings to elucidate the practical benefits of PET/CT as related to radiation treatment planning in HNCs. PMID:26644824

  4. Attenuation correction in emission tomography using the emission data—A review

    SciTech Connect

    Berker, Yannick Li, Yusheng

    2016-02-15

    The problem of attenuation correction (AC) for quantitative positron emission tomography (PET) had been considered solved to a large extent after the commercial availability of devices combining PET with computed tomography (CT) in 2001; single photon emission computed tomography (SPECT) has seen a similar development. However, stimulated in particular by technical advances toward clinical systems combining PET and magnetic resonance imaging (MRI), research interest in alternative approaches for PET AC has grown substantially in the last years. In this comprehensive literature review, the authors first present theoretical results with relevance to simultaneous reconstruction of attenuation and activity. The authors then look back at the early history of this research area especially in PET; since this history is closely interwoven with that of similar approaches in SPECT, these will also be covered. We then review algorithmic advances in PET, including analytic and iterative algorithms. The analytic approaches are either based on the Helgason–Ludwig data consistency conditions of the Radon transform, or generalizations of John’s partial differential equation; with respect to iterative methods, we discuss maximum likelihood reconstruction of attenuation and activity (MLAA), the maximum likelihood attenuation correction factors (MLACF) algorithm, and their offspring. The description of methods is followed by a structured account of applications for simultaneous reconstruction techniques: this discussion covers organ-specific applications, applications specific to PET/MRI, applications using supplemental transmission information, and motion-aware applications. After briefly summarizing SPECT applications, we consider recent developments using emission data other than unscattered photons. In summary, developments using time-of-flight (TOF) PET emission data for AC have shown promising advances and open a wide range of applications. These techniques may both remedy

  5. Attenuation correction in emission tomography using the emission data—A review

    PubMed Central

    Li, Yusheng

    2016-01-01

    The problem of attenuation correction (AC) for quantitative positron emission tomography (PET) had been considered solved to a large extent after the commercial availability of devices combining PET with computed tomography (CT) in 2001; single photon emission computed tomography (SPECT) has seen a similar development. However, stimulated in particular by technical advances toward clinical systems combining PET and magnetic resonance imaging (MRI), research interest in alternative approaches for PET AC has grown substantially in the last years. In this comprehensive literature review, the authors first present theoretical results with relevance to simultaneous reconstruction of attenuation and activity. The authors then look back at the early history of this research area especially in PET; since this history is closely interwoven with that of similar approaches in SPECT, these will also be covered. We then review algorithmic advances in PET, including analytic and iterative algorithms. The analytic approaches are either based on the Helgason–Ludwig data consistency conditions of the Radon transform, or generalizations of John’s partial differential equation; with respect to iterative methods, we discuss maximum likelihood reconstruction of attenuation and activity (MLAA), the maximum likelihood attenuation correction factors (MLACF) algorithm, and their offspring. The description of methods is followed by a structured account of applications for simultaneous reconstruction techniques: this discussion covers organ-specific applications, applications specific to PET/MRI, applications using supplemental transmission information, and motion-aware applications. After briefly summarizing SPECT applications, we consider recent developments using emission data other than unscattered photons. In summary, developments using time-of-flight (TOF) PET emission data for AC have shown promising advances and open a wide range of applications. These techniques may both remedy

  6. Clinical applications of positron emission tomography/computed tomography treatment planning.

    PubMed

    Macapinlac, Homer A

    2008-03-01

    Positron emission tomography/computed tomography (PET/CT) has provided an incremental dimension to the management of cancer patients by allowing the incorporation of important molecular images in radiotherapy treatment planning, ie, direct evaluation of tumor metabolism, cell proliferation, apoptosis, hypoxia, and angiogenesis. The CT component allows 4D imaging techniques, allowing improvements in the accuracy of treatment delivery by compensating for tumor/normal organ motion, improving PET quantification, and correcting PET and CT image misregistration. The combination of PET and CT in a single imaging system to obtain a fused anatomical and functional image data is now emerging as a promising tool in radiotherapy departments for improved delineation of tumor volumes and optimization of treatment plans. PET has the potential to improve radiotherapy planning by minimizing unnecessary irradiation of normal tissues and by reducing the risk of geographic miss. PET influences treatment planning in a high proportion of cases and therefore radiotherapy dose escalation without PET may be futile. This article examines the increasing role of hybrid PET/CT imaging techniques in process of improving treatment planning in oncology with emphasis on non small cell lung cancer.

  7. Quality Assurance of Positron Emission Tomography/Computed Tomography for Radiation Therapy

    SciTech Connect

    Xing Lei

    2008-05-01

    Recent advances in radiation delivery techniques, such as intensity-modulated radiation therapy, provide unprecedented ability to exquisitely control three-dimensional dose distribution. Development of on-board imaging and other image-guidance methods significantly improved our ability to better target a radiation beam to the tumor volume. However, in reality, accurate definition of the location and boundary of the tumor target is still problematic. Biologic and physiologic imaging promises to solve the problem in a fundamental way and has a more and more important role in patient staging, treatment planning, and therapeutic assessment in radiation therapy clinics. The last decade witnessed a dramatic increase in the use of positron emission tomography and computed tomography in radiotherapy practice. To ensure safe and effective use of nuclide imaging, a rigorous quality assurance (QA) protocol of the imaging tools and integration of the imaging data must be in place. The application of nuclide imaging in radiation oncology occurs at different levels of sophistication. Quantitative use of the imaging data in treatment planning through image registration and standardized uptake value calculation is often involved. Thus, QA should not be limited to the performance of the scanner, but should also include the process of implementing image data in treatment planning, such as data transfer, image registration, and quantitation of data for delineation of tumors and sensitive structures. This presentation discusses various aspects of nuclide imaging as applied to radiotherapy and describes the QA procedures necessary for the success of biologic image-guided radiation therapy.

  8. Extracardiac abnormalities on rubidium-82 cardiac positron emission tomography/computed tomography.

    PubMed

    Mirpour, Sahar; Khandani, Amir H

    2011-04-01

    The role of rubidium-82 (Rb) in recognizing extracardiac diseases is minimally investigated. The aim of this study was to evaluate the frequency and incremental added value of extracardiac findings on Rb cardiac positron emission tomography/computed tomography (PET/CT) studies. The study included all consecutive patients who were referred from July 2008 to June 2010 for Rb cardiac PET/CT to our institution. A blinded reader reviewed the images retrospectively to assess abnormal extracardiac PET findings. Images of 406 patients (142 men; 264 women) with a mean age±standard deviation of 59.72±12.93 years (range: 18-91 years) were reviewed. Incidental extracardiac abnormalities were found in 67 of 406 patients (16.5%). Among them, eight patients had malignant etiologies (1.9%). Incidental extracardiac findings were present in a significant portion of patients undergoing Rb cardiac PET/CT studies. Although most of the extracardiac findings on Rb cardiac PET/CT studies represented clinically known pathologies, these incidental findings on routine Rb cardiac PET/CT scans may have a significant clinical impact on a small number of patients, and offer the referring physician the chance to obtain additional clinically relevant information.

  9. Positron emission tomography / computerized tomography evaluation of primary Hodgkin's disease of liver.

    PubMed

    Gota, V S; Purandare, N C; Gujral, S; Shah, S; Nair, R; Rangarajan, V

    2009-01-01

    Occurrence of primary Hodgkin's lymphoma (PHL) of the liver is extremely rare. We report on a case of a 60-year-old male who presented with liver mass and B-symptomatology. Hepatoma or hepatic metastasis from a gastrointestinal primary was initially suspected. Tumor markers like AFP, CEA, Total PSA, and CA-19.9 were within normal limits. Positron Emission Tomography / Computerized Tomography (PET/CT) revealed a large hepatic lesion and a nodal mass in the porta hepatis. A liver biopsy was consistent with Hodgkin's lymphoma. There was complete regression of the hepatic lesion and evidence of shrinkage of the nodal mass following four cycles of chemotherapy. 18F Fluro -de-oxy Glucose (FDG) PET / CT in this case helped in establishing a primary hepatic lymphoma by demonstrating the absence of pathologically hypermetabolic foci in any other nodes or organs. PET / CT scan is a useful adjunct to conventional imaging and histopathology, not only to establish the initial diagnosis, but also to monitor treatment response in PHL.

  10. Small Animal Imaging using a Clinical Positron Emission Tomography/Computed Tomography and Super-Resolution

    PubMed Central

    DiFilippo, Frank P.; Patel, Sagar; Asosingh, Kewal; Erzurum, Serpil

    2013-01-01

    Considering the high cost of dedicated small animal positron emission tomography/computed tomography (PET/CT), an acceptable alternative in many situations might be clinical PET/CT. However spatial resolution and image quality are of concern. The utility of clinical PET/CT for small-animal research and image quality improvements from super-resolution (spatial subsampling) were investigated. National Electrical Manufacturers Association (NEMA) NU 4 phantom and mouse data were acquired with a clinical PET/CT scanner, both as conventional static and stepped scans. Static scans were reconstructed with and without point spread function (PSF) modeling. Stepped images were postprocessed with iterative deconvolution to produce super-resolution images. Image quality was markedly improved using the super-resolution technique, avoiding certain artifacts produced by PSF modeling. The 2-mm rod of the NU 4 phantom was visualized with high contrast, and the major structures of the mouse were well resolved. Although not a perfect substitute for a state-of-the-art small animal PET/CT scanner, a clinical PET/CT scanner with super-resolution produces acceptable small-animal image quality for many preclinical research studies. PMID:22554485

  11. A novel phantom design for emission tomography enabling scatter- and attenuation-"free" single-photon emission tomography imaging.

    PubMed

    Larsson, S A; Jonsson, C; Pagani, M; Johansson, L; Jacobsson, H

    2000-02-01

    A newly designed technique for experimental single-photon emission tomography (SPET) and positron emission tomography (PET) data acquisition with minor disturbing effects from scatter and attenuation has been developed. In principle, the method is based on discrete sampling of the radioactivity distribution in 3D objects by means of equidistant 2D planes. The starting point is a set of digitised 2D sections representing the radioactivity distribution of the 3D object. Having a radioactivity-related grey scale, the 2D images are printed on paper sheets using radioactive ink. The radioactive sheets can be shaped to the outline of the object and stacked into a 3D structure with air or some arbitrary dense material in between. For this work, equidistantly spaced transverse images of a uniform cylindrical phantom and of the digitised Hoffman rCBF phantom were selected and printed out on paper sheets. The uniform radioactivity sheets were imaged on the surface of a low-energy ultra-high-resolution collimator (4 mm full-width at half-maximum) of a three-headed SPET camera. The reproducibility was 0.7% and the uniformity was 1.2%. Each rCBF sheet, containing between 8.3 and 80 MBq of 99mTcO4- depending on size, was first imaged on the collimator and then stacked into a 3D structure with constant 12 mm air spacing between the slices. SPET was performed with the sheets perpendicular to the central axis of the camera. The total weight of the stacked rCBF phantom in air was 63 g, giving a scatter contribution comparable to that of a point source in air. The overall attenuation losses were <20%. A second SPET study was performed with 12-mm polystyrene plates in between the radioactive sheets. With polystyrene plates, the total phantom weight was 2300 g, giving a scatter and attenuation magnitude similar to that of a patient study. With the proposed technique, it is possible to obtain "ideal" experimental images (essentially built up by primary photons) for comparison with "real

  12. Retroperitoneal Endometriosis: A Possible Cause of False Positive Finding at 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

    PubMed Central

    Maffione, Anna Margherita; Panzavolta, Riccardo; Lisato, Laura Camilla; Ballotta, Maria; D'Isanto, Mariangela Zanforlini; Rubello, Domenico

    2015-01-01

    Endometriosis is a frequent and clinically relevant problem in young women. Laparoscopy is still the gold standard for the diagnosis of endometriosis, but frequently both morphologic and functional imaging techniques are involved in the diagnostic course before achieving a conclusive diagnosis. We present a case of a patient affected by infiltrating retroperitoneal endometriosis falsely interpreted as a malignant mass by contrast-enhanced magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography/computed tomography. PMID:26097425

  13. EEG, transmission computed tomography, and positron emission tomography with fluorodeoxyglucose /sup 18/F. Their use in adults with gliomas

    SciTech Connect

    Newmark, M.E.; Theodore, W.H.; Sato, S.; De La Paz, R.; Patronas, N.; Brooks, R.; Jabbari, B.; Di Chiro, G.

    1983-10-01

    We evaluated the relationship between findings from EEG, transmission computed tomography (CT), and positron emission tomography in 23 adults with gliomas. The cortical metabolic rate was suppressed in patients with and without focal slowing. Focal delta activity was not related to involvement of gray or white matter. Rhythmic delta activity and focal attenuation of background amplitude on EEG, however, were correlated with involvement of the thalamus.

  14. Preoperative [18]fluorodeoxyglucose-positron emission tomography/computed tomography in early stage breast cancer: Rates of distant metastases

    PubMed Central

    Vinh-Hung, Vincent; Everaert, Hendrik; Farid, Karim; Djassemi, Navid; Baudin-Veronique, Jacqueline; Bougas, Stefanos; Michailovich, Yuriy; Joachim-Contaret, Clarisse; Cécilia-Joseph, Elsa; Verschraegen, Claire; Nguyen, Nam P

    2017-01-01

    AIM To investigate rates of distant metastases (DM) detected with [18]fluorodeoxyglucose-positron emission tomography/computed tomography (18FDG-PET/CT) in early stage invasive breast cancer. METHODS We searched the English language literature databases of PubMed, EMBASE, ISI Web of Knowledge, Web of Science and Google Scholar, for publications on DM detected in patients who had 18FDG-PET/CT scans as part of the staging for early stages of breast cancer (stage I and II), prior to or immediately following surgery. Reports published between 2011 and 2017 were considered. The systematic review was conducted according to the PRISMA guidelines. RESULTS Among the 18 total studies included in the analysis, the risk of DM ranged from 0% to 8.3% and 0% to 12.9% for stage I and II invasive breast cancer, respectively. Among the patients with clinical stage II, the rate of occult metastases diagnosed by 18FDG-PET/CT was 7.2% (range, 0%-19.6%) for stage IIA and 15.8% (range, 0%-40.8%) for stage IIB. In young patients (< 40-year-old), 18FDG-PET/CT demonstrated a higher prevalence of DM at the time of diagnosis for those with aggressive histology (i.e., triple-negative receptors and poorly differentiated grade). CONCLUSION Young patients with poorly differentiated tumors and stage IIB triple-negative breast cancer may benefit from 18FDG-PET/CT at initial staging to detect occult DM prior to surgery. PMID:28794827

  15. Whole-body 18F FDG positron emission tomography/computed tomography evaluation of patients with uveal metastasis.

    PubMed

    Patel, Payal; Finger, Paul T

    2012-04-01

    To investigate the value of whole-body positron emission tomography/computed tomography (PET/CT) as a screening tool for patients with uveal metastasis. Retrospective observational case series. setting: Clinical practice. study population: Eighteen patients with uveal metastatic tumors were evaluated. Patients had no history of malignancy or a past medical history of malignancy without known active metastasis or known systemic cancer. intervention: Whole-body PET/CT was used as a screening tool to evaluate the intraocular tumor, to evaluate for multi-organ metastatic disease, and for cancer staging. main outcome measures: Detection and PET/CT uptake of primary tumors and metastatic disease. PET/CT imaging uncovered previously occult primary nonocular cancers (11/18, 61%), revealed progression of known primary systemic cancer (7/18, 39%), and confirmed multi-organ metastases in all cases (18/18, 100%). PET/CT findings were used to direct nonocular, confirmatory biopsy in 67% of cases (12/18). No uveal biopsies were required. PET/CT revealed lymph nodes and bone as the most common metastatic sites. The intraocular tumor was detectable in 28% of cases. Small, non-avid tumors and those within the hypermetabolic, PET-avid brain were falsely negative. This study suggests that whole-body PET/CT can be useful for clinical evaluation of patients with uveal metastases. It allowed for screening of the entire body and directed extraocular biopsy. Commonly used for tumor staging, PET/CT aided in the detection of the primary cancer in patients with metastatic uveal tumors. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Role of positron emission tomography in thyroid and neuroendocrine tumours.

    PubMed

    Treglia, Giorgio; Kroiss, Alexander S; Piccardo, Arnoldo; Lococo, Filippo; Santhanam, Prasanna; Imperiale, Alessio

    2017-09-25

    Positron emission tomography (PET) is an established imaging method in oncology. PET/computed tomography (PET/CT) and PET/magnetic resonance imaging (PET/MRI) are hybrid techniques which combine morphological information obtained by CT and MRI with functional data provided by PET. Several radiotracers evaluating different metabolic pathways or receptor status can be used as PET radiotracers to assess endocrine tumours such as thyroid tumours or neuroendocrine neoplasms (NENs). This review is focused to describe the role of PET imaging using different radiotracers in patients with thyroid tumours and NENs. The role of PET imaging with different radiotracers in several endocrine tumours including thyroid tumours, gastroenteropancreatic neoplasms (GEP-NENs), lung neuroendocrine neoplasms (LNENs), pheochromocytomas (PCC) and paragangliomas (PGL), and multiple endocrine neoplasia (MEN) syndromes has been described. Fluorine-18 fluorodeoxyglucose (18F-FDG) PET evaluating the glucose metabolism provides useful diagnostic and prognostic information in patients with thyroid tumours. Iodine-124 (124I) assessing the iodine metabolism (124I) PET may be used for dosimetry and diagnostic purposes in thyroid tumours. In patients with NENs specific radiotracers can be used for diagnostic purposes such as somatostatin analogues labeled with gallium-68 (68Ga-DOTA-peptides) evaluating somatostatin receptor expression and fluorine-18 fluorodihydroxyphenylalanine (18F- FDOPA) assessing the uptake, decarboxylation and storage of amine precursors. One advantage of 68Ga-DOTA-peptides PET is to select patients with well-differentiated and inoperable NENs for peptide receptor radionuclide therapy (PRRT). 18F-FDG PET may provide useful prognostic information in patients with high-grade NENs. PET imaging with different radiotracers is a useful functional imaging technique in the work-up of several endocrine tumours.

  17. Bayesian image reconstruction for improving detection performance of muon tomography.

    PubMed

    Wang, Guobao; Schultz, Larry J; Qi, Jinyi

    2009-05-01

    Muon tomography is a novel technology that is being developed for detecting high-Z materials in vehicles or cargo containers. Maximum likelihood methods have been developed for reconstructing the scattering density image from muon measurements. However, the instability of maximum likelihood estimation often results in noisy images and low detectability of high-Z targets. In this paper, we propose using regularization to improve the image quality of muon tomography. We formulate the muon reconstruction problem in a Bayesian framework by introducing a prior distribution on scattering density images. An iterative shrinkage algorithm is derived to maximize the log posterior distribution. At each iteration, the algorithm obtains the maximum a posteriori update by shrinking an unregularized maximum likelihood update. Inverse quadratic shrinkage functions are derived for generalized Laplacian priors and inverse cubic shrinkage functions are derived for generalized Gaussian priors. Receiver operating characteristic studies using simulated data demonstrate that the Bayesian reconstruction can greatly improve the detection performance of muon tomography.

  18. Detecting correlated errors in state-preparation-and-measurement tomography

    NASA Astrophysics Data System (ADS)

    Jackson, Christopher; van Enk, S. J.

    2015-10-01

    Whereas in standard quantum-state tomography one estimates an unknown state by performing various measurements with known devices, and whereas in detector tomography one estimates the positive-operator-valued-measurement elements of a measurement device by subjecting to it various known states, we consider here the case of SPAM (state preparation and measurement) tomography where neither the states nor the measurement device are assumed known. For d -dimensional systems measured by d -outcome detectors, we find there are at most d2(d2-1 ) "gauge" parameters that can never be determined by any such experiment, irrespective of the number of unknown states and unknown devices. For the case d =2 we find gauge-invariant quantities that can be accessed directly experimentally and that can be used to detect and describe SPAM errors. In particular, we identify conditions whose violations detect the presence of correlations between SPAM errors. From the perspective of SPAM tomography, standard quantum-state tomography and detector tomography are protocols that fix the gauge parameters through the assumption that some set of fiducial measurements is known or that some set of fiducial states is known, respectively.

  19. Characterization of pulmonary lesions in patients with suspected lung cancer: computed tomography versus [¹⁸F] fluorodeoxyglucose-positron emission tomography/computed tomography.

    PubMed

    Harders, Stefan Walbom; Madsen, Hans Henrik; Hjorthaug, Karin; Arveschoug, Anne Kirstine; Rasmussen, Torben Riis; Meldgaard, Peter; Andersen, Johanne Bach; Pilegaard, Hans Kristian; Hager, Henrik; Rehling, Michael; Rasmussen, Finn

    2012-10-16

    Pulmonary nodules are of high clinical importance, given they may prove to be an early manifestation of lung cancer. Pulmonary nodules are small, focal, radiographic opacities that may be solitary or multiple. A solitary pulmonary nodule is a single, small (<-30 mm in diameter) opacity. Larger opacities are called masses and are often malignant. As imaging techniques improve and more nodules are detected, the optimal management of pulmonary nodules remains unclear. However, the question of malignancy of any given nodule remains the same. A standard contrast-enhanced computed tomography (CT) scan is often the first examination, followed by a number of other examinations. The purpose of this study was to examine the clinical feasibility of CT versus integrated [18F]fluorodeoxyglucose-positron emission tomography (PET)/low-dose CT scan in patients with suspected lung cancer and pulmonary lesions on CT. All results were controlled for reproducibility. We found that when used early in the work-up of the lesions, CT raised the prevalence of lung cancer in the population to the point where further diagnostic imaging examination could be considered futile. We also found that the overall diagnostic accuracy, as well as the classification probabilities and predictive values of the two modalities were not significantly different; the reproducibility of these results was substantial.

  20. Altered regional myocardial metabolism in congestive cardiomyopathy detected by positron tomography

    SciTech Connect

    Geltman, E.M.; Smith, J.L.; Beecher, D.; Ludbrook, P.A.; Ter-Pogossian, M.M.; Sobel, B.E.

    1983-05-01

    The present study was performed to determine whether positron emission tomography performed after intravenous injection of /sup 11/C-palmitate permits detection and characterization of congestive cardiomyopathy. Positron emission tomography was performed after the intravenous injection of /sup 11/C-palmitate in 13 normal subjects, 17 patients with congestive cardiomyopathy, and six patients with initial transmural myocardial infarction (defined electrocardiographically). Regionally depressed accumulation of /sup 11/C-palmitate was assessed, characterized, and quantified in seven parallel transaxial reconstructions in each patient. Patients with cardiomyopathy exhibited a larger number of discrete noncontiguous regions of accumulation of palmitate within the myocardium than either control subjects or patients with transmural infarction (17.4 +/- 0.6 (SEM) versus 11.8 +/- 0.7 versus 10.3 +/- 0.6, p less than 0.005). Similarly, regions of accumulation of palmitate were irregularly shaped in patients with cardiomyopathy, with a longer normalized perimeter than either control subjects or patients with transmural infarction (2.0 +/- 0.05 versus 1.8 +/- 0.06 versus 1.9 +/- 0.09, p less than 0.05). Regional abnormalities of the accumulation of 11C-palmitate could not be explained by regional differences in left ventricular wall motion or myocardial perfusion. Thus, marked heterogeneity of regional myocardial accumulation of 11C-palmitate is detectable and quantifiable in patients with congestive cardiomyopathy by positron emission tomography and may be particularly valuable for early detection and characterization of cardiomyopathy.

  1. Integrated Positron Emission Tomography/Computed Tomography May Render Bone Scintigraphy Unnecessary to Investigate Suspected Metastatic Breast Cancer

    PubMed Central

    Morris, Patrick G.; Lynch, Colleen; Feeney, John N.; Patil, Sujata; Howard, Jane; Larson, Steven M.; Dickler, Maura; Hudis, Clifford A.; Jochelson, Maxine; McArthur, Heather L.

    2010-01-01

    Purpose Although the accurate detection of osseous metastases in the evaluation of patients with suspected metastatic breast cancer (MBC) has significant prognostic and therapeutic implications, the ideal diagnostic approach is uncertain. In this retrospective, single-institution study, we compare the diagnostic performance of integrated positron emission tomography/computed tomography (PET/CT) and bone scintigraphy (BSc) in women with suspected MBC. Patients and Methods Women with suspected MBC evaluated with PET/CT and BSc (within 30 days) between January 1, 2003 and June 30, 2008, were identified through institutional databases. Electronic medical records were reviewed, and radiology reports were classified as positive/negative/equivocal for osseous metastases. A nuclear medicine radiologist (blinded to correlative and clinical end points) reviewed all equivocal PET/CT and BSc images and reclassified some reports. Final PET/CT and BSc classifications were compared. Baseline patient/tumor characteristics and bone pathology were recorded and compared to the final imaging results. Results We identified 163 women who had a median age of 52 years (range, 30 to 90 years); 32% had locally advanced breast cancer, 42% had been diagnosed with breast cancer less than 12 weeks before identification. Twenty studies were originally deemed equivocal (five with PET/CT, and 15 with BSc), and 13 (65%) of these studies were reclassified after radiology review. Overall, PET/CT and BSc were highly concordant for reporting osseous metastases with 132 paired studies (81%); 32 (20%) were positive, and 100 (61%) were negative. Thirty-one occurrences (19%) were discordant. Twelve of these (39%) had pathology confirming osseous metastases: nine (of 18) were PET/CT positive and BSc negative; one (of three) was PET/CT positive and BSc equivocal; and two (of two) were PET/CT equivocal and BSc negative. Conclusion This study supports the use of PET/CT in detecting osseous metastases for

  2. The clinical value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in postoperative patients with gastrointestinal mucinous adenocarcinoma.

    PubMed

    Yang, Zhong-Yi; Hu, Si-Long; Shi, Wei; Zhu, Bei-Ling; Xu, Jun-Yan; Zhang, Ying-Jian

    2011-11-01

    To evaluate the clinical value of F-fluorodeoxyglucose positron emission tomography and computed tomography (¹⁸F-FDG PET/CT) in postoperative patients with gastrointestinal mucinous adenocarcinoma. From July 2007 to March 2009, 30 patients who had previous surgical resection of histopathologically diagnosed gastrointestinal mucinous adenocarcinoma underwent ¹⁸F-FDG PET/CT scans in our center. The standard of reference for tumor recurrence, regional lymph node (LN) metastasis, peritoneal and distant metastasis consisted of histopathologic confirmation or clinical follow-up information for at least 6 months after PET/CT examinations. With final diagnosis, tumor recurrences were confirmed in eight of the 30 patients (26.7%). If a maximum standardized uptake value (SUVmax) of 2.5 or more was used as a cut-off point, the sensitivity, specificity, and accuracy of PET/CT were 87.5, 77.3, and 80.0%, respectively. However, if an SUVmax of 4.0 or more was the criterion, the sensitivity, specificity, and accuracy were 25.0, 86.4, and 70.0%, respectively. A cut-off point of 2.5 showed a higher sensitivity (P=0.041), and there was no statistical difference in the specificity and the accuracy of these two criteria. For the diagnosis of metastasis in regional LNs and peritoneum, the detection rate was 95.2 and 86.4%, respectively. In addition, we followed up 20 patients with 26 suspicious distant lesions. The sensitivity, specificity, and accuracy were 58.3, 92.9, and 76.9%, respectively. ¹⁸F-FDG PET/CT may be effective to discriminate tumor recurrence, and to detect regional LNs, peritoneal and distant metastasis in postoperative patients with gastrointestinal mucinous adenocarcinoma.

  3. 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)

  4. Florbetapir positron emission tomography and cerebrospinal fluid biomarkers

    PubMed Central

    Hake, Ann; Trzepacz, Paula T.; Wang, Shufang; Yu, Peng; Case, Michael; Hochstetler, Helen; Witte, Michael M.; Degenhardt, Elisabeth K.; Dean, Robert A.

    2015-01-01

    Background We evaluated the relationship between florbetapir-F18 positron emission tomography (FBP PET) and cerebrospinal fluid (CSF) biomarkers. Methods Alzheimer’s Disease Neuroimaging Initiative (ADNI)-GO/2 healthy control (HC), mild cognitive impairment (MCI), and Alzheimer’s disease (AD) dementia subjects with clinical measures and CSF collected ±90 days of FBP PET data were analyzed using correlation and logistic regression. Results In HC and MCI subjects, FBP PET anterior and posterior cingulate and composite standard uptake value ratios correlated with CSF amyloid beta (Aβ1-42) and tau/Aβ1-42 ratios. Using logistic regression, Aβ1-42, total tau (t-tau), phosphorylated tau181P (p-tau), and FBP PET composite each differentiated HC versus AD. Aβ1-42 and t-tau distinguished MCI versus AD, without additional contribution by FBP PET. Total tau and p-tau added discriminative power to FBP PET when classifying HC versus AD. Conclusion Based on cross-sectional diagnostic groups, both amyloid and tau measures distinguish healthy from demented subjects. Longitudinal analyses are needed. PMID:25916563

  5. The next generation of positron emission tomography radiopharmaceuticals in oncology.

    PubMed

    Rice, Samuel L; Roney, Celeste A; Daumar, Pierre; Lewis, Jason S

    2011-07-01

    Although (18)F-fluorodeoxyglucose ((18)F-FDG) is still the most widely used positron emission tomography (PET) radiotracer, there are a few well-known limitations to its use. The last decade has seen the development of new PET probes for in vivo visualization of specific molecular targets, along with important technical advances in the production of positron-emitting radionuclides and their related labeling methods. As such, a broad range of new PET tracers are in preclinical development or have recently entered clinical trials. The topics covered in this review include labeling methods, biological targets, and the most recent preclinical or clinical data of some of the next generation of PET radiopharmaceuticals. This review, which is by no means exhaustive, has been separated into sections related to the PET radionuclide used for radiolabeling: fluorine-18, for the labeling of agents such as FACBC, FDHT, choline, and Galacto-RGD; carbon-11, for the labeling of choline; gallium-68, for the labeling of peptides such as DOTATOC and bombesin analogs; and the long-lived radionuclides iodine-124 and zirconium-89 for the labeling of monoclonal antibodies cG250, and J591 and trastuzumab, respectively. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Automated identification of the lung contours in positron emission tomography

    NASA Astrophysics Data System (ADS)

    Nery, F.; Silvestre Silva, J.; Ferreira, N. C.; Caramelo, F. J.; Faustino, R.

    2013-03-01

    Positron Emission Tomography (PET) is a nuclear medicine imaging technique that permits to analyze, in three dimensions, the physiological processes in vivo. One of the areas where PET has demonstrated its advantages is in the staging of lung cancer, where it offers better sensitivity and specificity than other techniques such as CT. On the other hand, accurate segmentation, an important procedure for Computer Aided Diagnostics (CAD) and automated image analysis, is a challenging task given the low spatial resolution and the high noise that are intrinsic characteristics of PET images. This work presents an algorithm for the segmentation of lungs in PET images, to be used in CAD and group analysis in a large patient database. The lung boundaries are automatically extracted from a PET volume through the application of a marker-driven watershed segmentation procedure which is robust to the noise. In order to test the effectiveness of the proposed method, we compared the segmentation results in several slices using our approach with the results obtained from manual delineation. The manual delineation was performed by nuclear medicine physicians that used a software routine that we developed specifically for this task. To quantify the similarity between the contours obtained from the two methods, we used figures of merit based on region and also on contour definitions. Results show that the performance of the algorithm was similar to the performance of human physicians. Additionally, we found that the algorithm-physician agreement is similar (statistically significant) to the inter-physician agreement.

  7. FPGA-Based Pulse Parameter Discovery for Positron Emission Tomography.

    PubMed

    Haselman, Michael; Hauck, Scott; Lewellen, Thomas K; Miyaoka, Robert S

    2009-10-24

    Modern Field Programmable Gate Arrays (FPGAs) are capable of performing complex digital signal processing algorithms with clock rates well above 100MHz. This, combined with FPGA's low expense and ease of use make them an ideal technology for a data acquisition system for a positron emission tomography (PET) scanner. The University of Washington is producing a series of high-resolution, small-animal PET scanners that utilize FPGAs as the core of the front-end electronics. For these next generation scanners, functions that are typically performed in dedicated circuits, or offline, are being migrated to the FPGA. This will not only simplify the electronics, but the features of modern FPGAs can be utilizes to add significant signal processing power to produce higher resolution images. In this paper we report how we utilize the reconfigurable property of an FPGA to self-calibrate itself to determine pulse parameters necessary for some of the pulse processing steps. Specifically, we show how the FPGA can generate a reference pulse based on actual pulse data instead of a model. We also report how other properties of the photodetector pulse (baseline, pulse length, average pulse energy and event triggers) can be determined automatically by the FPGA.

  8. Positron Emission Tomography Application to Drug Development and Research

    NASA Astrophysics Data System (ADS)

    Salvadori, Piero A.

    The research for the identification and development of new drugs represents a very complex process implying long times and massive investments. This process was not able to parallel the rate of discoveries made in the field of genomic and molecular biology and a gap created between demand of new drugs and the ability of pharmaceutical companies to select good candidates. Positron Emission Tomography, among the different Molecular Imaging modalities, could represent a new tool for the early assessment and screening of new drug candidates and, due to its physical performances and the characteristics of positron-labeled tracers, gain the role of "Biomarker" accepted by the Companies and the Regulatory Bodies of Drug Agencies. To fulfil this task PET has to exploit all of its special features such as data absolute quantification and modelling, high spatial resolution and dynamic imaging. Relevant efforts need to be directed to the careful design and validation of experimental protocols with the main goal of achieving consistency in multi- centric trials.

  9. Microfluidics for Positron Emission Tomography (PET) Imaging Probe Development

    PubMed Central

    Wang, Ming-Wei; Lin, Wei-Yu; Liu, Kan; Masterman-Smith, Michael; Shen, Clifton Kwang-Fu

    2012-01-01

    Due to increased needs for Positron Emission Tomography (PET) scanning, high demands for a wide variety of radiolabeled compounds will have to be met by exploiting novel radiochemistry and engineering technologies to improve the production and development of PET probes. The application of microfluidic reactors to perform radiosyntheses is currently attracting a great deal of interest because of their potential to deliver many advantages over conventional labeling systems. Microfluidic-based radiochemistry can lead to the use of smaller quantities of precursors, accelerated reaction rates and easier purification processes with greater yield and higher specific activity of desired probes. Several ‘proof-of-principle’ examples, along with basics of device architecture and operation, and potential limitations of each design are discussed here. Along with the concept of radioisotope distribution from centralized cyclotron facilities to individual imaging centers and laboratories (“decentralized model”), an easy-to-use, standalone, flexible, fully-automated radiochemical microfluidic platform can open up to simpler and more cost-effective procedures for molecular imaging using PET. PMID:20643021

  10. Brain activity following esophageal acid infusion using positron emission tomography

    PubMed Central

    Kobayashi, Shigeyuki; Abe, Yasuhiko; Tashiro, Manabu; Koike, Tomoyuki; Iijima, Katsunori; Imatani, Akira; Ohara, Shuichi; Watanabe, Satoshi; Fukudo, Shin; Shimosegawa, Tooru

    2010-01-01

    AIM: To investigate symptoms and brain activity following esophageal acid infusion. METHODS: Fifteen healthy volunteers were recruited for the study. Hydrochloric acid (pH 1 and 2) and distilled water (pH 7) were randomly and repeatedly infused into the esophagus. The brain activity was evaluated by positron emission tomography. The severity of heartburn elicited by the infusion was rated on an auditory analog scale of 0-10. RESULTS: The severity of heartburn following each infusion showed a step-wise increase with increasing acidity of the perfusate. The heartburn scores were significantly higher in the second pH 1 infusion compared with the first infusion. Acid and distilled water infusion induced activation of various brain areas such as the anterior insula, temporal gyrus, and anterior/posterior cingulate cortex. At pH 1 or 2, in particular, activation was observed in some emotion-related brain areas such as the more anterior part of the anterior cingulate cortex, parahippocampal gyrus, or the temporal pole. Strong activation of the orbitofrontal cortex was found by subtraction analysis of the two second pH 1 infusions, with a significant increase of heartburn symptoms. CONCLUSION: Emotion-related brain areas were activated by esophageal acid stimulation. The orbitofrontal area might be involved in symptom processing, with esophageal sensitization induced by repeated acid stimulation. PMID:21086568

  11. Brain single photon emission computed tomography in neonates

    SciTech Connect

    Denays, R.; Van Pachterbeke, T.; Tondeur, M.; Spehl, M.; Toppet, V.; Ham, H.; Piepsz, A.; Rubinstein, M.; Nol, P.H.; Haumont, D. )

    1989-08-01

    This study was designed to rate the clinical value of ({sup 123}I)iodoamphetamine (IMP) or ({sup 99m}Tc) hexamethyl propylene amine oxyme (HM-PAO) brain single photon emission computed tomography (SPECT) in neonates, especially in those likely to develop cerebral palsy. The results showed that SPECT abnormalities were congruent in most cases with structural lesions demonstrated by ultrasonography. However, mild bilateral ventricular dilatation and bilateral subependymal porencephalic cysts diagnosed by ultrasound were not associated with an abnormal SPECT finding. In contrast, some cortical periventricular and sylvian lesions and all the parasagittal lesions well visualized in SPECT studies were not diagnosed by ultrasound scans. In neonates with subependymal and/or intraventricular hemorrhage the existence of a parenchymal abnormality was only diagnosed by SPECT. These results indicate that ({sup 123}I)IMP or ({sup 99m}Tc)HM-PAO brain SPECT shows a potential clinical value as the neurodevelopmental outcome is clearly related to the site, the extent, and the number of cerebral lesions. Long-term clinical follow-up is, however, mandatory in order to define which SPECT abnormality is associated with neurologic deficit.

  12. Modularized compact positron emission tomography detector for rapid system development.

    PubMed

    Xi, Daoming; Liu, Xiang; Zeng, Chen; Liu, Wei; Li, Yanzhao; Hua, Yuexuan; Mei, Xiongze; Kim, Heejong; Xiao, Peng; Kao, Chien-Min; Xie, Qingguo

    2017-01-01

    We report the development of a modularized compact positron emission tomography (PET) detector that outputs serial streams of digital samples of PET event pulses via an Ethernet interface using the UDP/IP protocol to enable rapid configuration of a PET system by connecting multiple such detectors via a network switch to a computer. Presently, the detector is [Formula: see text] in extent (excluding I/O connectors) and contains an [Formula: see text] array of [Formula: see text] one-to-one coupled lutetium-yttrium oxyorthosilicate/silicon photomultiplier pixels. It employs cross-wire and stripline readouts to merge the outputs of the 216 detector pixels to 24 channels. Signals at these channels are sampled using a built-in 24-ch, 4-level field programmable gate arrays-only multivoltage threshold digitizer. In the computer, software programs are implemented to analyze the digital samples to extract event information and to perform energy qualification and coincidence filtering. We have developed two such detectors. We show that all their pixels can be accurately discriminated and measure a crystal-level energy resolution of 14.4% to 19.4% and a detector-level coincidence time resolution of 1.67 ns FWHM. Preliminary imaging results suggests that a PET system based on the detectors can achieve an image resolution of [Formula: see text].

  13. Application of silicon photomultipliers to positron emission tomography.

    PubMed

    Roncali, Emilie; Cherry, Simon R

    2011-04-01

    Historically, positron emission tomography (PET) systems have been based on scintillation crystals coupled to photomultipliers tubes (PMTs). However, the limited quantum efficiency, bulkiness, and relatively high cost per unit surface area of PMTs, along with the growth of new applications for PET, offers opportunities for other photodetectors. Among these, small-animal scanners, hybrid PET/MRI systems, and incorporation of time-of-flight information are of particular interest and require low-cost, compact, fast, and magnetic field compatible photodetectors. With high quantum efficiency and compact structure, avalanche photodiodes (APDs) overcome several of the drawbacks of PMTs, but this is offset by degraded signal-to-noise and timing properties. Silicon photomultipliers (SiPMs) offer an alternative solution, combining many of the advantages of PMTs and APDs. They have high gain, excellent timing properties and are insensitive to magnetic fields. At the present time, SiPM technology is rapidly developing and therefore an investigation into optimal design and operating conditions is underway together with detailed characterization of SiPM-based PET detectors. Published data are extremely promising and show good energy and timing resolution, as well as the ability to decode small scintillator arrays. SiPMs clearly have the potential to be the photodetector of choice for some, or even perhaps most, PET systems.

  14. European health telematics networks for positron emission tomography

    NASA Astrophysics Data System (ADS)

    Kontaxakis, George; Pozo, Miguel Angel; Ohl, Roland; Visvikis, Dimitris; Sachpazidis, Ilias; Ortega, Fernando; Guerra, Pedro; Cheze-Le Rest, Catherine; Selby, Peter; Pan, Leyun; Diaz, Javier; Dimitrakopoulou-Strauss, Antonia; Santos, Andres; Strauss, Ludwig; Sakas, Georgios

    2006-12-01

    A pilot network of positron emission tomography centers across Europe has been setup employing telemedicine services. The primary aim is to bring all PET centers in Europe (and beyond) closer, by integrating advanced medical imaging technology and health telematics networks applications into a single, easy to operate health telematics platform, which allows secure transmission of medical data via a variety of telecommunications channels and fosters the cooperation between professionals in the field. The platform runs on PCs with Windows 2000/XP and incorporates advanced techniques for image visualization, analysis and fusion. The communication between two connected workstations is based on a TCP/IP connection secured by secure socket layers and virtual private network or jabber protocols. A teleconsultation can be online (with both physicians physically present) or offline (via transmission of messages which contain image data and other information). An interface sharing protocol enables online teleconsultations even over low bandwidth connections. This initiative promotes the cooperation and improved communication between nuclear medicine professionals, offering options for second opinion and training. It permits physicians to remotely consult patient data, even if they are away from the physical examination site.

  15. The economics of creating a positron emission tomography center.

    PubMed

    Lissak, R J

    2000-10-01

    Positron emission tomography (PET) scanning has been a powerful research tool since its inception. Changes in the marketplace that have allowed PET to move into the clinical environment include the commercial availability of appropriate radiopharmaceuticals, reimbursement of procedures by insurance companies, and increasing awareness of physicians of the benefits of PET. Facilities that are interested in clinical PET need to develop a process to purchase equipment with an appropriate business plan. This is necessary to assure financial viability and to convince hospital administrators of the viability. The creation of a successful PET program requires an understanding of all aspects relating to a center. The process begins with reviewing the mission statement of the facility. The next step is to prepare the feasibility study, which includes reviewing the existing marketplace and determining the volume, level of referring physicians' interest, and availability of radiopharmaceuticals. Finally, an appropriate pro forma needs to be constructed to facilitate the final decision concerning the potential financial viability of such an endeavor.

  16. SAKE: a new quantification tool for positron emission tomography studies.

    PubMed

    Veronese, Mattia; Rizzo, Gaia; Turkheimer, Federico E; Bertoldo, Alessandra

    2013-07-01

    In dynamic positron emission tomography (PET) studies, spectral analysis (SA) refers to a data-driven quantification method, based on a single-input single-output model for which the transfer function is described by a sum of exponential terms. SA allows to quantify numerosities, amplitudes and eigenvalues of the transfer function allowing, in this way, to separate kinetic components of the tissue tracer activity with minimal model assumptions. The SA model can be solved with a linear estimator alone or with numerical filters, resulting in different types of SA approaches. Once estimated the number, amplitudes and eigenvalues of the transfer function, one can distinguish the presence in the system of irreversible and/or reversible components as well as derive parameters of physiological significance. These characteristics make it an appealing alternative method to compartmental models which are widely used for the quantitative analysis of dynamic studies acquired with PET. However, despite its applicability to a large number of PET tracers, its implementation is not straightforward and its utilization in the nuclear medicine community has been limited especially by the lack of an user-friendly software application. In this paper we proposed SAKE, a computer program for the quantitative analysis of PET data through the main SA methods. SAKE offers a unified pipeline of analysis usable also by people with limited computer knowledge but with high interest in SA. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  17. Positron emission tomography: a first-hand experience.

    PubMed

    Traylor, J

    2000-01-01

    In July 1999, the University of Kansas Hospital installed a positron emission tomography (PET) scanner and added PET to the imaging technologies it offers patients and physicians. The new service is managed by the nuclear medicine section in the department of radiology. Plans are being implemented now to install a cyclotron in March 2000. Prior to installation of the scanner, a radiation area survey was performed in the space being considered for the PET unit. We also needed to address other critical considerations, including the manufacturer's requirements for construction of the scanner room, special electrical needs, and how the system would connect to our existing information network. It is important to work closely with your chief financial officer and chief operations officer from the beginning of the purchasing process so that these administrators have up-to-date, supportive information about PET and the progress of the installation. We made use of a variety of promotional techniques to market the new service, including broadcast e-mail, an open house for potential referring physicians, postings on the nuclear medicine Web site and communication through the local media. We also worked with the major insurance providers that utilize our hospital to educate them about PET and its benefits. In addition, we trained our own billing staff about procedures that optimize reimbursement for PET. In March 2000, University of Kansas Hospital will install the first cyclotron in the state, enabling us to generate the drugs used for PET scanning and potentially to add targets for research PET radiopharmaceuticals.

  18. Variation in Positron Emission Tomography Use After Colon Cancer Resection

    PubMed Central

    Bailey, Christina E.; Hu, Chung-Yuan; You, Y. Nancy; Kaur, Harmeet; Ernst, Randy D.; Chang, George J.

    2015-01-01

    Purpose: Colon cancer surveillance guidelines do not routinely include positron emission tomography (PET) imaging; however, its use after surgical resection has been increasing. We evaluated the secular patterns of PET use after surgical resection of colon cancer among elderly patients and identified factors associated with its increasing use. Patients and Methods: We used the SEER-linked Medicare database (July 2001 through December 2009) to establish a retrospective cohort of patients age ≥ 66 years who had undergone surgical resection for colon cancer. Postoperative PET use was assessed with the test for trends. Patient, tumor, and treatment characteristics were analyzed using univariable and multivariable logistic regression analyses. Results: Of the 39,221 patients with colon cancer, 6,326 (16.1%) had undergone a PET scan within 2 years after surgery. The use rate steadily increased over time. The majority of PET scans had been performed within 2 months after surgery. Among patients who had undergone a PET scan, 3,644 (57.6%) had also undergone preoperative imaging, and 1,977 (54.3%) of these patients had undergone reimaging with PET within 2 months after surgery. Marriage, year of diagnosis, tumor stage, preoperative imaging, postoperative visit to a medical oncologist, and adjuvant chemotherapy were significantly associated with increased PET use. Conclusion: PET use after colon cancer resection is steadily increasing, and further study is needed to understand the clinical value and effectiveness of PET scans and the reasons for this departure from guideline-concordant care. PMID:25852143

  19. Geoscientific process monitoring with positron emission tomography (GeoPET)

    NASA Astrophysics Data System (ADS)

    Kulenkampff, Johannes; Gründig, Marion; Zakhnini, Abdelhamid; Lippmann-Pipke, Johanna

    2016-08-01

    Transport processes in geomaterials can be observed with input-output experiments, which yield no direct information on the impact of heterogeneities, or they can be assessed by model simulations based on structural imaging using µ-CT. Positron emission tomography (PET) provides an alternative experimental observation method which directly and quantitatively yields the spatio-temporal distribution of tracer concentration. Process observation with PET benefits from its extremely high sensitivity together with a resolution that is acceptable in relation to standard drill core sizes. We strongly recommend applying high-resolution PET scanners in order to achieve a resolution on the order of 1 mm. We discuss the particularities of PET applications in geoscientific experiments (GeoPET), which essentially are due to high material density. Although PET is rather insensitive to matrix effects, mass attenuation and Compton scattering have to be corrected thoroughly in order to derive quantitative values. Examples of process monitoring of advection and diffusion processes with GeoPET illustrate the procedure and the experimental conditions, as well as the benefits and limits of the method.

  20. The Next Generation of Positron Emission Tomography Radiopharmaceuticals in Oncology

    PubMed Central

    Rice, Samuel L.; Roney, Celeste A.; Daumar, Pierre; Lewis, Jason S.

    2015-01-01

    Although 18F-fluorodeoxyglucose (18F-FDG) is still the most widely used positron emission tomography (PET) radiotracer, there are a few well-known limitations to its use. The last decade has seen the development of new PET probes for in vivo visualization of specific molecular targets, along with important technical advances in the production of positron-emitting radionuclides and their related labeling methods. As such, a broad range of new PET tracers are in preclinical development or have recently entered clinical trials. The topics covered in this review include labeling methods, biological targets, and the most recent preclinical or clinical data of some of the next generation of PET radiopharmaceuticals. This review, which is by no means exhaustive, has been separated into sections related to the PET radionuclide used for radiolabeling: fluorine-18, for the labeling of agents such as FACBC, FDHT, choline, and Galacto-RGD; carbon-11, for the labeling of choline; gallium-68, for the labeling of peptides such as DOTATOC and bombesin analogs; and the long-lived radionuclides iodine-124 and zirconium-89 for the labeling of monoclonal antibodies cG250, and J591 and trastuzumab, respectively. PMID:21624561

  1. Simultaneous laser speckle imaging and positron emission tomography

    NASA Astrophysics Data System (ADS)

    Gramer, M.; Feuerstein, D.; Backes, H.; Takagaki, M.; Kumagai, T.; Graf, R.

    2013-06-01

    Complex biological systems often require measurements of multiple parameters with high temporal and spatial resolution. Multimodal approaches and the combination of methods are therefore a powerful tool to address such scientific questions. Laser speckle imaging (LSI) is an optical method that monitors dynamic changes in cortical blood flow (CBF) with high temporal resolution. Positron emission tomography (PET) allows for quantitative imaging of physiological processes and is a gold standard method to determine absolute cerebral blood flow. We developed a setup that allows simultaneous measurement with both modalities. Here, we simultaneously measured CBF with PET and LSI in rats and analyzed how the correlation of PET and LSI is modified when (1) different methods are used for the calculation of speckle inverse correlation time (ICT), (2) speckle data is acquired through thinned or craniectomized skull, (3) influence of surface vessels is removed from the speckle data. For the latter, a method for automated vessel segmentation from LSI data was developed. We obtained the best correlation (R² = 0.890, p<0.001) when correcting for surface vessel structures taking into account the contribution of static scatterers while keeping the coherence factor constant. However, using the originally published relation, which allows a 900 times faster computation of blood flow maps, still provided a good correlation (R2 = 0.879, p<0.001). Given the good correlation between LSI and PET we used our data to calibrate the speckle ICT. Thus, LSI provides CBF in absolute units at high temporal resolution.

  2. Positron Emission Tomography Detector Development for Plant Biology

    SciTech Connect

    Weisenberger, A G; McKisson, J; Stolin, A; Zorn, C; Howell, C R; Crowell, A S; Reid, C D; Majewski, S; Smith, M F

    2010-01-01

    There are opportunities for the development of new tools to advance plant biology research through the use of radionuclides. Thomas Jefferson National Accelerator Facility, Duke University, West Virginia University and the University of Maryland are collaborating on the development of radionuclide imaging technologies to facilitate plant biology research. Biological research into optimizing plant productivity under various environmental constraints, biofuel and carbon sequestration research are areas that could potentially benefit from new imaging technologies. Using 11CO2 tracers, the investigators at Triangle University Nuclear Laboratory / Duke University Phytotron are currently researching the dynamical responses of plants to environmental changes forecasted from increasing greenhouse trace gases involved in global change. The biological research primary focus is to investigate the impact of elevated atmospheric CO2 and nutrients limitation on carbon and nitrogen dynamics in plants. We report here on preliminary results of 11CO2 plant imaging experiments involving barley plants using Jefferson Lab dual planar positron emission tomography detectors to image 11CO2 in live barley plants. New detector designs will be developed based on the preliminary studies reported here and further planned.

  3. Enhancement of positron emission tomography-computed tomography image quality using the principle of stochastic resonance.

    PubMed

    Pandey, Anil Kumar; Sharma, Sanjay Kumar; Sharma, Punit; Singh, Harmandeep; Patel, Chetan; Sarkar, Kaushik; Kumar, Rakesh; Bal, Chandra Sekhar

    2014-10-01

    Acquisition of higher counts improves visual perception of positron emission tomography-computed tomography (PET-CT) image. Larger radiopharmaceutical doses (implies more radiation dose) are administered to acquire this count in a short time period. However, diagnostic information does not increase after a certain threshold of counts. This study was conducted to develop a post processing method based on principle of "stochastic resonance" to improve visual perception of the PET-CT image having a required threshold counts. PET-CT images (JPEG file format) with low, medium, and high counts in the image were included in this study. The image was corrupted with the addition of Poisson noise. The amplitude of the Poisson noise was adjusted by dividing each pixel by a constant 1, 2, 4, 8, 16, and 32. The best amplitude of the noise that gave best images quality was selected based on high value of entropy of the output image, high value of structural similarity index and feature similarity index. Visual perception of the image was evaluated by two nuclear medicine physicians. The variation in structural and feature similarity of the image was not appreciable visually, but statistically images deteriorated as the noise amplitude increases although maintaining structural (above 70%) and feature (above 80%) similarity of input images in all cases. We obtained the best image quality at noise amplitude "4" in which 88% structural and 95% feature similarity of the input images was retained. This method of stochastic resonance can be used to improve the visual perception of the PET-CT image. This can indirectly lead to reduction of radiation dose.

  4. Trends in radiation protection of positron emission tomography/computed tomography imaging.

    PubMed

    Alenezi, A; Soliman, K

    2015-06-01

    Over the past decade, the number of positron emission tomography/computed tomography (PET/CT) imaging procedures has increased substantially. This imaging technique provides accurate functional and anatomical information, particularly for oncological applications. Separately, both PET and CT are considered as high-dose imaging modalities. With the increased use of PET/CT, one could expect an increase in radiation doses to staff and patients. As such, major efforts have been made to reduce radiation dose in PET/CT facilities. Variations in working techniques have made it difficult to compare published results. This study aimed to review the literature on proposed methods to reduce patient and staff dose in clinical PET/CT imaging. A brief overview of some published information on staff and patient doses will be analysed and presented. Recent trends regarding radiation protection in PET/CT imaging will be discussed, and practical recommendations for reducing radiation doses to staff and patients will be discussed and summarised. Generally, the CT dose component is often higher in magnitude than the dose from PET alone; as such, focusing on CT dose reduction will decrease the overall patient dose in PET/CT imaging studies. The following factors should be considered in order to reduce the patient's dose from CT alone: proper justification for ordering contrast-enhanced CT; use of automatic exposure control features; use of adaptive statistical iterative reconstruction algorithms; and optimisation of scan parameters, especially scan length. The PET dose component can be reduced by administration of lower activity to the patient, optimisation of the workflow, and appropriate use of protective devices and engineered systems. At the international level, there is wide variation in work practices among institutions. The current observed trends are such that the annual dose limits for radiation workers in PET/CT imaging are unlikely to be exceeded.

  5. Does positron emission tomography/computed tomography change management in colorectal cancer?

    PubMed

    Falconer, Rachel; Connor, Saxon; Balasingam, Adrian; Eglinton, Tim

    2016-10-27

    Positron emission tomography/computed tomography (PET/CT) is used pre-operatively in patients with metastatic or recurrent colorectal cancer to identify those who have potentially curative disease. However, a recent randomized trial questioned the added benefit of PET/CT over conventional imaging in patients with liver metastases. The aim of this study was to determine the proportion of patients with colorectal cancer in whom PET/CT altered surgical management, in a single tertiary centre. This was a retrospective study of all patients with colorectal cancer who had a PET/CT for colorectal cancer, funded by the Canterbury District Health Board between 2010 and 2014. Some 111 PET/CT scans were performed on 105 patients. A total of 38% of PET/CT were for patients with known or suspected liver metastases, 23% for suspected local recurrence and 18% for known or suspected lung metastases. Five scans were for post-operative patients with a rising carcinoembryonic antigen and no attributable source on conventional imaging. PET/CT identified additional extrahepatic sites of disease in 19 of 111 (17%) scans in patients deemed to have potentially operable disease. Overall, PET/CT altered surgical management following six of 42 (14%) scans for patients with liver metastases, four of 20 (20%) scans for patients with lung metastases and six of 26 (23%) scans for patients with local recurrence. PET/CT remains a useful adjunct to conventional imaging in the pre-operative workup of patients with colorectal cancer. © 2016 Royal Australasian College of Surgeons.

  6. 18F-fluorodeoxyglucose positron-emission tomography-computed tomography to diagnose recurrent cancer

    PubMed Central

    You, J J; Cline, K J; Gu, C-S; Pritchard, K I; Dayes, I S; Gulenchyn, K Y; Inculet, R I; Dhesy-Thind, S K; Freeman, M A; Chan, A M; Julian, J A; Levine, M N

    2015-01-01

    Background: Sometimes the diagnosis of recurrent cancer in patients with a previous malignancy can be challenging. This prospective cohort study assessed the clinical utility of 18F-fluorodeoxyglucose positron-emission tomography-computed tomography (18F-FDG PET-CT) in the diagnosis of clinically suspected recurrence of cancer. Methods: Patients were eligible if cancer recurrence (non-small-cell lung (NSCL), breast, head and neck, ovarian, oesophageal, Hodgkin's or non-Hodgkin's lymphoma) was suspected clinically, and if conventional imaging was non-diagnostic. Clinicians were asked to indicate their management plan before and after 18F-FDG PET-CT scanning. The primary outcome was change in planned management after 18F-FDG PET-CT. Results: Between April 2009 and June 2011, 101 patients (age, median 65 years; 55% female) were enroled from four cancer centres in Ontario, Canada. Distribution by primary tumour type was: NSCL (55%), breast (19%), ovarian (10%), oesophageal (6%), lymphoma (6%), and head and neck (4%). Of the 99 subjects who underwent 18F-FDG PET-CT, planned management changed after 18F-FDG PET-CT in 52 subjects (53%, 95% confidence interval (CI), 42–63%); a major change in plan from no treatment to treatment was observed in 38 subjects (38%, 95% CI, 29–49%), and was typically associated with 18F-FDG PET-CT findings that were positive for recurrent cancer (37 subjects). After 3 months, the stated post-18F-FDG PET-CT management plan was actually completed in 88 subjects (89%, 95% CI, 81–94%). Conclusion: In patients with suspected cancer recurrence and conventional imaging that is non-diagnostic, 18F-FDG PET-CT often provides new information that leads to important changes in patient management. PMID:25942398

  7. Predicting exercise capacity after lobectomy by single photon emission computed tomography and computed tomography.

    PubMed

    Nagamatsu, Yoshinori; Sueyoshi, Susumu; Sasahara, Hiroko; Oka, Yousuke; Kumazoe, Hiroyuki; Mitsuoka, Masahiro; Akagi, Yoshito

    2016-09-01

    This study compared the prediction of postoperative exercise capacity by employing lung perfusion scintigraphy images obtained with single photon emission computed tomography together with computed tomography (SPECT/CT) versus the common method of counting subsegments (SC method). In 18 patients scheduled for lobectomy, predicted postoperative maximum oxygen uptake per kilogram body weight ([Formula: see text]) was calculated by the SPECT/CT and SC methods. Correlations were examined between the [Formula: see text] predicted by SPECT/CT or the SC method, and the actual [Formula: see text] measured at 2 weeks (mean 15.4 ± 1.5 days) and 1 month (mean 29.1 ± 0.75 days) after surgery to determine whether SPECT/CT was more accurate than SC for predicting postoperative exercise capacity. There was a significant positive correlation between the [Formula: see text] predicted by SPECT/CT and the actual value at 2 weeks (r = 0.802, p < 0.0001) or 1 month (r = 0.770, p < 0.0001). There was also a significant positive correlation between the [Formula: see text] predicted by SC and the actual value at 2 weeks (r = 0.785, p < 0.0001) or 1 month (r = 0.784, p < 0.0001). This study showed that both SPECT/CT and the SC method were useful for predicting postoperative [Formula: see text] in the clinical setting.

  8. Relationship of computed tomography perfusion and positron emission tomography to tumour progression in malignant glioma

    SciTech Connect

    Yeung, Timothy P C; Yartsev, Slav; Lee, Ting-Yim; Wong, Eugene; He, Wenqing; Fisher, Barbara; VanderSpek, Lauren L; Macdonald, David; Bauman, Glenn

    2014-02-15

    Introduction: This study aimed to explore the potential for computed tomography (CT) perfusion and 18-Fluorodeoxyglucose positron emission tomography (FDG-PET) in predicting sites of future progressive tumour on a voxel-by-voxel basis after radiotherapy and chemotherapy. Methods: Ten patients underwent pre-radiotherapy magnetic resonance (MR), FDG-PET and CT perfusion near the end of radiotherapy and repeated post-radiotherapy follow-up MR scans. The relationships between these images and tumour progression were assessed using logistic regression. Cross-validation with receiver operating characteristic (ROC) analysis was used to assess the value of these images in predicting sites of tumour progression. Results: Pre-radiotherapy MR-defined gross tumour; near-end-of-radiotherapy CT-defined enhancing lesion; CT perfusion blood flow (BF), blood volume (BV) and permeability-surface area (PS) product; FDG-PET standard uptake value (SUV); and SUV:BF showed significant associations with tumour progression on follow-up MR imaging (P < 0.0001). The mean sensitivity (±standard deviation), specificity and area under the ROC curve (AUC) of PS were 0.64 ± 0.15, 0.74 ± 0.07 and 0.72 ± 0.12 respectively. This mean AUC was higher than that of the pre-radiotherapy MR-defined gross tumour and near-end-of-radiotherapy CT-defined enhancing lesion (both AUCs = 0.6 ± 0.1, P ≤ 0.03). The multivariate model using BF, BV, PS and SUV had a mean AUC of 0.8 ± 0.1, but this was not significantly higher than the PS only model. Conclusion: PS is the single best predictor of tumour progression when compared to other parameters, but voxel-based prediction based on logistic regression had modest sensitivity and specificity.

  9. Multidimensional characterization of an entangled photon-pair source via stimulated emission tomography.

    PubMed

    Fang, B; Liscidini, M; Sipe, J E; Lorenz, V O

    2016-05-02

    Using stimulated emission tomography, we characterize an entangled photon-pair source in the energy and polarization degrees of freedom, with a precision far exceeding what could be obtained by quantum state tomography. Through this multidimensional tomography we find that energy-polarization correlations are a cause of polarization-entanglement degradation, demonstrating that this technique provides useful information for source engineering and can accelerate the development of quantum information processing systems dependent on many degrees of freedom.

  10. Noise reduction in muon tomography for detecting high density objects

    NASA Astrophysics Data System (ADS)

    Benettoni, M.; Bettella, G.; Bonomi, G.; Calvagno, G.; Calvini, P.; Checchia, P.; Cortelazzo, G.; Cossutta, L.; Donzella, A.; Furlan, M.; Gonella, F.; Pegoraro, M.; Rigoni Garola, A.; Ronchese, P.; Squarcia, S.; Subieta, M.; Vanini, S.; Viesti, G.; Zanuttigh, P.; Zenoni, A.; Zumerle, G.

    2013-12-01

    The muon tomography technique, based on multiple Coulomb scattering of cosmic ray muons, has been proposed as a tool to detect the presence of high density objects inside closed volumes. In this paper a new and innovative method is presented to handle the density fluctuations (noise) of reconstructed images, a well known problem of this technique. The effectiveness of our method is evaluated using experimental data obtained with a muon tomography prototype located at the Legnaro National Laboratories (LNL) of the Istituto Nazionale di Fisica Nucleare (INFN). The results reported in this paper, obtained with real cosmic ray data, show that with appropriate image filtering and muon momentum classification, the muon tomography technique can detect high density materials, such as lead, albeit surrounded by light or medium density material, in short times. A comparison with algorithms published in literature is also presented.

  11. Detection of microspheres in vivo using multispectral optoacoustic tomography.

    PubMed

    Bhutiani, N; Kimbrough, C W; Burton, N C; Morscher, S; Egger, M; McMasters, K; Woloszynska-Read, A; El-Baz, A; McNally, L R

    2017-02-06

    We introduce a new approach to detect individual microparticles that contain NIR fluorescent dye by multispectral optoacoustic tomography in the context of the hemoglobin-rich environment within murine liver. We encapsulated a near infrared (NIR) fluorescent dye within polystyrene microspheres, then injected them into the ileocolic vein, which drains to the liver. NIR absorption was determined using multispectral optoacoustic tomography. To quantitate the minimum diameter of microspheres, we used both colorimetric and spatial information to segment the regions in which the microspheres appear. Regional diameter was estimated by doubling the maximum regional distance. We found that the minimum microsphere size threshold for detection by multispectral optoacoustic tomography images is 78.9 µm.

  12. Lhermitte-Duclos disease presenting with positron emission tomography-magnetic resonance fusion imaging: a case report.

    PubMed

    Calabria, Ferdinando; Grillea, Giovanni; Zinzi, Maddalena; Barbarisi, Manlio; Siravo, Emanuele; Bartolo, Marcello; Cantore, Giampaolo; Colonnese, Claudio; Grasso, Cristina; Schillaci, Orazio

    2012-03-06

    Lhermitte-Duclos disease or dysplastic gangliocytoma of the cerebellum is an extremely rare tumor. It is a slowly enlarging mass within the cerebellar cortex. The majority of cases are diagnosed in the third or fourth decade of life. We report the case of a 37-year-old Caucasian woman who underwent positron emission tomography-computed tomography with fluorine-18-fluorodeoxyglucose for evaluation of a solitary lung node. No pathological uptake was detected in the solitary lung node but the positron emission tomography-computed tomography of her brain showed intense tracer uptake, suggestive of a malignant neoplasm, in a mass in her left cerebellar lobe. Our patient had experienced two years of occipital headache and movement disorder. Subsequently, magnetic resonance imaging was performed with contrast agent administration, showing a large subtentorial mass in her left cerebellar hemisphere, with compression and dislocation of the fourth ventricle. Metabolic data provided by positron emission tomography and morphological magnetic resonance imaging views were fused in post-processing, allowing a diagnosis of dysplastic gangliocytoma with increased glucose metabolism. Total resection of the tumor was performed and histological examination confirmed the diagnosis of Lhermitte-Duclos disease. Our case indicates that increased uptake of fluorine-18-fluorodeoxyglucose may be misinterpreted as a neoplastic process in the evaluation of patients with Lhermitte-Duclos disease, but supports the usefulness of integrated positron emission tomography-magnetic resonance imaging in the exact pathophysiologic explanation of this disease and in making the correct diagnosis. However, an accurate physical examination and exact knowledge of clinical data is of the utmost importance.

  13. Hypoxia imaging using Positron Emission Tomography in non-small cell lung cancer: implications for radiotherapy.

    PubMed

    Bollineni, Vikram Rao; Wiegman, Erwin M; Pruim, Jan; Groen, Harry J M; Langendijk, Johannes A

    2012-12-01

    Tumour hypoxia is an important contributor to radioresistance. Thus, increasing the radiation dose to hypoxic areas may result in improved locoregional tumour control. However, this strategy requires accurate detection of the hypoxic sub-volume using PET imaging. Secondly, hypoxia imaging may also provide prognostic information and may be of help to monitor treatment response. Therefore, a systematic review of the scientific literature was carried out on the use of Positron Emission Tomography (PET) to image Tumour hypoxia in non-small cell lung cancer (NSCLC). More specifically, the purpose of this review was (1) to summarize the different hypoxia tracers used, (2) to investigate whether Tumour hypoxia can be detected in NSCLC and finally (3) whether the presence of hypoxia can be used to predict outcome.

  14. Fluorodeoxyglucose positron emission tomography/computed tomography findings in a patient with cerebellar mutism after operation in posterior fossa.

    PubMed

    Gedik, Gonca Kara; Sari, Oktay; Köktekir, Ender; Akdemir, Gökhan

    2017-04-01

    Cerebellar mutism is a transient period of speechlessness that evolves after posterior fossa surgery in children. Although direct cerebellar and brain stem injury and supratentorial dysfunction have been implicated in the mediation of mutism, the pathophysiological mechanisms involved in the evolution of this kind of mutism remain unclear. Magnetic resonance imaging revealed dentatothalamocortical tract injuries and single photon emission computed tomography showed cerebellar and cerebral hypoperfusion in patients with cerebellar mutism. However, findings with (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in this group of patients have not been documented previously. In this clinical case, we report a patient who experienced cerebellar mutism after undergoing a posterior fossa surgery. Right cerebellar and left frontal lobe hypometabolism was shown using FDG PET/CT. The FDG metabolism of both the cerebellum and the frontal lobe returned to normal levels after the resolution of the mutism symptoms. Copyright © 2017. Published by Elsevier Taiwan.

  15. The role of single-photon emission computed tomography and SPECT/computed tomography in oncologic imaging.

    PubMed

    Brandon, David; Alazraki, Adina; Halkar, Raghuveer K; Alazraki, Naomi P

    2011-02-01

    Single-photon emission computed tomography (SPECT) and hybrid SPECT/computed tomography (SPECT/CT) cameras have emerged as a dominant technology providing invaluable tools in the diagnosis, staging, therapy planning, and treatment monitoring of multiple cancers over the past decade. In the same way that positron emission tomography (PET) benefited from the addition of CT, functional SPECT and anatomic CT data obtained as a single study have shown improvements in diagnostic imaging sensitivity and specificity by improving lesion conspicuity, reducing false positives, and clarifying indeterminate lesions. Furthermore, the anatomic imaging better localizes the functional data, which can be critical in surgical and therapy planning. As more disease-specific imaging agents become available, the role of SPECT/CT in the new paradigms of molecular imaging for personalized medicine will expand. Established and emerging uses of SPECT/CT in a wide variety of oncologic diseases, as well as radiation exposure issues, are reviewed. Published by Elsevier Inc.

  16. Structural damage detection via impediographic tomography

    NASA Astrophysics Data System (ADS)

    Zhao, Liuxian; Yang, Jie; Wang, K. W.; Semperlotti, Fabio

    2015-03-01

    We investigate the use of impediographic tomography to achieve high sensitivity and high resolution damage identification in plate-like structures. The impediographic approach exploits the coupled piezo-resistive and electrostatic response of the host structure to generate high sensitivity and high resolution maps of its internal electrical conductivity. Focused acoustic waves are used to generate localized electrical conductivity perturbations that allow a drastic improvement in the conditioning of the inverse problem. The localized acoustic perturbations are obtained by exploiting the concept of Frequency Selective Structures (FSS) in which intentional mistuning of periodically distributed structural features, such as thin notches, enables self-focusing and vibration localization by using a single ultrasonic transducer. The impediographic reconstruction is achieved by using two different methods: the 0-Laplacian and the Levenberg-Marquardt. Both methodologies are compared in terms of accuracy of the reconstructed electrical conductivity and of their ability to deal with important practical issues such as limited view and limited perturbation data. Numerical results show that, although both approaches perform well in terms of damage identification, localization, and sizing, the LM technique allows higher flexibility in handling imperfect data.

  17. 18F-FDG positron emission tomography in oncology: main indications.

    PubMed

    Vercher-Conejero, J L; Gámez Cenzano, C

    2016-01-01

    The development of molecular and functional imaging with new imaging techniques such as computed tomography, magnetic resonance imaging, and positron emission tomography (PET) among others, has greatly improved the detection of tumors, tumor staging, and the detection of possible recurrences. Furthermore, the combination of these different imaging modalities and the continual development of radiotracers for PET have advanced our understanding and knowledge of the different pathophysiological processes in cancer, thereby helping to make treatment more efficacious, improving patients' quality of life, and increasing survival. PET is one of the imaging techniques that has attracted the most interest in recent years for its diagnostic capabilities. Its ability to anatomically locate pathologic foci of metabolic activity has revolutionized the detection and staging of many tumors, exponentially broadening its potential indications not only in oncology but also in other fields such as cardiology, neurology, and inflammatory and infectious diseases. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Detecting small scale CO2 emission structures using OCO-2

    NASA Astrophysics Data System (ADS)

    Schwandner, Florian M.; Eldering, Annmarie; Verhulst, Kristal R.; Miller, Charles E.; Nguyen, Hai M.; Oda, Tomohiro; O'Dell, Christopher; Rao, Preeti; Kahn, Brian; Crisp, David; Gunson, Michael R.; Sanchez, Robert M.; Ashok, Manasa; Pieri, David; Linick, Justin P.; Yuen, Karen

    2016-04-01

    Localized carbon dioxide (CO2) emission structures cover spatial domains of less than 50 km diameter and include cities and transportation networks, as well as fossil fuel production, upgrading and distribution infra-structure. Anthropogenic sources increasingly upset the natural balance between natural carbon sources and sinks. Mitigation of resulting climate change impacts requires management of emissions, and emissions management requires monitoring, reporting and verification. Space-borne measurements provide a unique opportunity to detect, quantify, and analyze small scale and point source emissions on a global scale. NASA's first satellite dedicated to atmospheric CO2 observation, the July 2014 launched Orbiting Carbon Observatory (OCO-2), now leads the afternoon constellation of satellites (A-Train). Its continuous swath of 2 to 10 km in width and eight footprints across can slice through coincident emission plumes and may provide momentary cross sections. First OCO-2 results demonstrate that we can detect localized source signals in the form of urban total column averaged CO2 enhancements of ~2 ppm against suburban and rural backgrounds. OCO-2's multi-sounding swath observing geometry reveals intra-urban spatial structures reflected in XCO2 data, previously unobserved from space. The transition from single-shot GOSAT soundings detecting urban/rural differences (Kort et al., 2012) to hundreds of soundings per OCO-2 swath opens up the path to future capabilities enabling urban tomography of greenhouse gases. For singular point sources like coal fired power plants, we have developed proxy detections of plumes using bands of imaging spectrometers with sensitivity to SO2 in the thermal infrared (ASTER). This approach provides a means to automate plume detection with subsequent matching and mining of OCO-2 data for enhanced detection efficiency and validation. © California Institute of Technology

  19. Evaluation of acoustic tomography for tree decay detection

    Treesearch

    Shanquing Liang; Xiping Wang; Janice Wiedenbeck; Zhiyong Cai; Feng Fu

    2008-01-01

    In this study, the acoustic tomography technique was used to detect internal decay in high value black cherry (Prunus seratina) trees. Two-dimensional images of the cross sections of the tree samples were constructed using PiCUS Q70 software. The trees were felled following the field test, and a disc from each testing elevation was subsequently cut...

  20. Acoustic tomography for decay detection in black cherry trees

    Treesearch

    Xiping Wang; Jan Wiedenbeck; Shanqing Liang

    2009-01-01

    This study investigated the potential of using acoustic tomography for detecting internal decay in high-value hardwood trees in the forest. Twelve black cherry (Prunus serotina) trees that had a wide range of physical characteristics were tested in a stand of second-growth hardwoods in Kane, PA, using a PiCUS Sonic Tomograph tool. The trees were felled after the field...

  1. Gamma knife treatment for refractory epilepsy in seizure focus localized by positron emission tomography/CT★

    PubMed Central

    Bai, Xia; Wang, Xuemei; Wang, Hongwei; Zhao, Shigang; Han, Xiaodong; Hao, Linjun; Wang, Xiangcheng

    2012-01-01

    A total of 80 patients with refractory epilepsy were recruited from the Inner Mongolia Medical College Affiliated Hospital. The foci of 60% of the patients could be positioned using a combined positron emission tomography/CT imaging modality. Hyper- and hypometabolism foci were examined as part of this study. Patients who had abnormal metabolism in positron emission tomography/CT imaging were divided into intermittent-phase group and the seizure-phase group. The intermittent-phase group was further divided into a single-focus group and a multiple-foci group according to the number of seizure foci detected by imaging. Following gamma knife treatment, seizure frequency was significantly lower in the intermittent-phase group and the seizure-phase group. Wieser’s classification reached Grade I or II in nearly 40% of patients. Seizure frequency was significantly lower following treatment, but Wieser’s classification score was significantly higher in the seizure-phase group compared with the intermittent-phase group. Seizure frequency was significantly lower following treatment in the single-focus group, but Wieser’s classification score was significantly higher in the single-focus group as compared with the multiple-foci group. PMID:25317147

  2. Routine positron emission tomography and positron emission tomography/computed tomography in melanoma staging with positive sentinel node biopsy is of limited benefit.

    PubMed

    Constantinidou, Anastasia; Hofman, Michael; O'Doherty, Michael; Acland, Katharine M; Healy, Ciaran; Harries, Mark

    2008-02-01

    Positron emission tomography (PET) is increasingly used for the staging and management of melanoma. The aim of this study was to evaluate the role of PET or PET/ computed tomography (CT) as a routine procedure in patients with positive sentinel node biopsy (SNB). Thirty patients with melanoma of Breslow thickness greater than 1 mm who had PET or PET/CT scans performed within 100 days after a positive SNB were reviewed retrospectively. Two patients (6%) had a positive PET scan, none of which were melanoma related. The first patient had a synchronous neuroendocrine thyroid tumour and the second patient had increased uptake in the chest wall, which proved to be old trauma. Lymph node dissection was positive in five cases (16%). With a median follow-up of 24 months, 21 patients remained disease free. In none of the 30 cases did the early PET scan after a positive SNB alter subsequent melanoma management. The role of PET scanning soon after a positive sentinel node biopsy seems to be of limited benefit. It is questionable whether any imaging is beneficial at this stage. The results of this review suggest that PET scanning might not be indicated for this group of patients.

  3. Positron emission tomography-computed tomography versus positron emission tomography-magnetic resonance imaging for diagnosis of oral squamous cell carcinoma: A pilot study.

    PubMed

    Schlittenbauer, Tilo; Zeilinger, Martin; Nkenke, Emeka; Kreißel, Sebastian; Wurm, Matthias C; Lell, Michael; Kuwert, Torsten; Beck, Michael

    2015-12-01

    Diagnostic imaging of head and neck cancer has made enormous progress during recent years. Next to morphological imaging modalities (computed tomography [CT] and magnetic resonance imaging [MRI]), there are also hybrid imaging systems that combine functional and morphological information (positron emission tomography [PET]/CT and PET/MRI). The aim of this study was to compare the diagnostic accuracy of PET/MRI in the diagnosis of head and neck cancer with other imaging modalities (MRI, CT, PET/CT). Ten patients (nine male and one female) with histologically proven oral squamous cell carcinoma participated in an 18 F-FDG-PET/CT scan and an additional 18 F-FDG PET/MRI scan prior to surgery. The morphological and functional results were compared with the histological results. Inclusion criteria were histologically proven oral squamous cell carcinoma and no prior surgical intervention, medical therapy, or local external radiation. There was no significant correlation between tumor differentiation and maximum standard uptake values. Functional imaging showed a slightly better correlation with the measurement of the maximal tumor diameter, whereas pure morphological imaging showed a better correlation with the measurement of infiltration depth. Only with PET/MRI could correct lymph node staging be reached; the other imaging tools showed false-negative or false-positive results. In conclusion, we showed in our limited patient cohort that PET/MRI is superior to the morphological imaging modalities, especially for lymph node staging.

  4. [Positron emission tomography and computed tomography (PET/CT) in lung cancer].

    PubMed

    Altamirano-Ley, Javier; Estrada-Sánchez, Gisela Rocío; Ochoa-Carrillo, Francisco Javier

    2007-01-01

    Lung cancer is the most frequent cause of death due to neoplasm in Western populations, with >660,000 new diagnoses of lung cancer per year according to the World Health Organization. We undertook this study to emphasize the role of positron emission tomography to all health care professionals involved in lung cancer diagnosis. There are false negatives with PET-(18)FDG in carcinoids and broncheoalveolar carcinoma in almost 40% of the cases. One relatively common cause of false positives is the vocal cord and adjacent muscles contralateral and compensatory to the lung lesion that show an increased uptake of (18)FDG because of lesions in the laryngeal nerve by the tumor or secondary to surgery. It should not be confounded with metastases. There is sufficient scientific evidence pointing to the usefulness of PET studies and its evolution to PET/CT, especially in patients with lung cancer. This can resolve doubts by the oncologist and patient when there is a suspicious malignant lesion by the following: characterizing solitary pulmonary nodules (benign or malignant), localizing the optimal site for the biopsy, diagnosis of the primary tumor for initial staging, evaluation of mediastinal involvement and distant metastasis, evaluate and restage residual tumor, assessment of recurrence, monitoring response, prognostic prediction and radiotherapy planning.

  5. Prediction of positron emission tomography/computed tomography (PET/CT) positivity in patients with high-risk primary melanoma.

    PubMed

    Danielsen, Maria; Kjaer, Andreas; Wu, Max; Martineau, Lea; Nosrati, Mehdi; Leong, Stanley Pl; Sagebiel, Richard W; Iii, James R Miller; Kashani-Sabet, Mohammed

    2016-01-01

    Positron emission tomography/computed tomography (PET/CT) is an important tool to identify occult melanoma metastasis. To date, it is controversial which patients with primary cutaneous melanoma should have staging PET/CT. In this retrospective analysis of more than 800 consecutive patients with cutaneous melanoma, we sought to identify factors predictive of PET/CT positivity in the setting of newly-diagnosed high-risk primary melanoma to determine those patients most appropriate to undergo a PET/CT scan as part of their diagnostic work up. 167 patients with newly-diagnosed high-risk primary cutaneous melanoma underwent a PET/CT scan performed as part of their initial staging. Clinical and histologic factors were evaluated as possible predictors of melanoma metastasis identified on PET/CT scanning using both univariate and multivariate logistic regression. In all, 32 patients (19.2%) had a positive PET/CT finding of metastatic melanoma. In more than half of these patients (56.3%), PET/CT scanning identified disease that was not detectable on clinical examination. Mitotic rate, tumor thickness, lymphadenopathy, and bleeding were significantly predictive of PET/CT positivity. A combinatorial index constructed from these factors revealed a significant association between number of high-risk factors observed and prevalence of PET/CT positivity, which increased from 5.8% (with the presence of 0-2 factors) to 100.0%, when all four factors were present. These results indicate that combining clinical and histologic prognostic factors enables the identification of patients with a higher likelihood of a positive PET/CT scan.

  6. Prediction of positron emission tomography/computed tomography (PET/CT) positivity in patients with high-risk primary melanoma

    PubMed Central

    Danielsen, Maria; Kjaer, Andreas; Wu, Max; Martineau, Lea; Nosrati, Mehdi; Leong, Stanley PL; Sagebiel, Richard W; III, James R Miller; Kashani-Sabet, Mohammed

    2016-01-01

    Positron emission tomography/computed tomography (PET/CT) is an important tool to identify occult melanoma metastasis. To date, it is controversial which patients with primary cutaneous melanoma should have staging PET/CT. In this retrospective analysis of more than 800 consecutive patients with cutaneous melanoma, we sought to identify factors predictive of PET/CT positivity in the setting of newly-diagnosed high-risk primary melanoma to determine those patients most appropriate to undergo a PET/CT scan as part of their diagnostic work up. 167 patients with newly-diagnosed high-risk primary cutaneous melanoma underwent a PET/CT scan performed as part of their initial staging. Clinical and histologic factors were evaluated as possible predictors of melanoma metastasis identified on PET/CT scanning using both univariate and multivariate logistic regression. In all, 32 patients (19.2%) had a positive PET/CT finding of metastatic melanoma. In more than half of these patients (56.3%), PET/CT scanning identified disease that was not detectable on clinical examination. Mitotic rate, tumor thickness, lymphadenopathy, and bleeding were significantly predictive of PET/CT positivity. A combinatorial index constructed from these factors revealed a significant association between number of high-risk factors observed and prevalence of PET/CT positivity, which increased from 5.8% (with the presence of 0-2 factors) to 100.0%, when all four factors were present. These results indicate that combining clinical and histologic prognostic factors enables the identification of patients with a higher likelihood of a positive PET/CT scan. PMID:27766186

  7. Role of bone marrow biopsy in staging of patients with classical Hodgkin's lymphoma undergoing positron emission tomography/computed tomography.

    PubMed

    Puccini, B; Nassi, L; Minoia, C; Volpetti, S; Ciancia, R; Riccomagno, P C; Di Rocco, A; Mulè, A; Toldo, C; Sassone, M C; Guariglia, R; Filì, C; Finolezzi, E; Falorio, S; Zanon, S; Furlan, A; Doa, G; Zaja, F

    2017-07-01

    Several studies suggested that staging bone marrow biopsy (BMB) could be omitted in patients with classical Hodgkin's lymphoma (cHL) when a positron emission tomography/computed tomography (PET/CT) is performed at baseline.To address the concordance between BMB and PET/CT in the detection of bone marrow involvement (BMI) and the BMB role in determining the Ann Arbor stage, we retrospectively collected data on 1244 consecutive patients with cHL diagnosed from January 2007 to December 2013. One thousand eighty-five patients who had undergone both BMB and PET/CT were analyzed, comparing the Ann Arbor stage assessed with PET/CT only to that resulting from PET/CT combined with BMB.One hundred sixty-nine patients (16%) showed at least one focal skeletal lesion (FSL) at PET/CT evaluation. Only 55 patients had a positive BMB (5.1%); 34 of them presented at least one FSL at PET/CT. To the contrary, 895 out of 1030 patients with a negative BMB did not show any FSL (86.9%). Positive and negative predictive values of PET/CT for BMI were 20 and 98%, respectively; sensitivity and specificity were 62 and 87%, respectively. Fifty-four out of 55 patients with a positive BMB could have been evaluated as an advanced stage just after PET/CT; only one patient (0.1%) would have been differently treated without BMB.Our data showed a very high negative predictive value of PET/CT for BMI and a negligible influence of BMB on treatment planning, strengthening the recent indications that BMB could be safely omitted in cHL patients staged with PET/CT.

  8. 18-Fluoro-2-deoxyglucose positron emission tomography-computed tomography: an additional tool in the diagnosis of prosthetic valve endocarditis.

    PubMed

    Ricciardi, Alessandra; Sordillo, Pasquale; Ceccarelli, Laura; Maffongelli, Gaetano; Calisti, Giorgio; Di Pietro, Barbara; Caracciolo, Cristiana Ragano; Schillaci, Orazio; Pellegrino, Antonio; Chiariello, Luigi; Andreoni, Massimo; Sarmati, Loredana

    2014-11-01

    To evaluate the role of 18-fluoro-2-deoxyglucose positron emission tomography-computed tomography ((18)F-FDG-PET-CT) in the diagnosis of infectious endocarditis (IE). We retrospectively examined 27 consecutive patients who were admitted to the Infectious Diseases Department of Tor Vergata University Hospital between 2009 and 2013 with a suspicion of IE. The final IE diagnosis was defined according to the modified Duke criteria, and the microbiological and diagnostic results were collected for each patient. Twenty out of 27 patients had a suspected prosthetic valve endocarditis (PVE) and seven had a suspected native valve endocarditis (NVE). Twenty-five out of 27 patients (92%) had a confirmed diagnosis of IE (18/25 PVE and 7/25 NVE); 16 had a positive echocardiography evaluation and 16 had positive (18)F-FDG-PET-CT findings. Echocardiography showed a higher sensitivity as a diagnostic tool for the detection of IE compared to (18)F-FDG-PET-CT (80% vs. 55%). However, a greater number of PVE had positive (18)F-FDG-PET-CT results compared to those with positive echocardiography findings (11/13 vs. 9/13), and overall 89% (16/18) of confirmed PVE resulted (18)F-FDG-PET-CT positive. Analyzing only the cases who underwent transoesophageal echocardiography, (18)F-FDG-PET-CT showed a sensitivity of 85% in PVE (vs. 69% for echocardiography and 77% for the Duke criteria). All seven patients with NVE had a positive echocardiography and negative (18)F-FDG-PET-CT findings (p<0.001). The results of this study further highlight the limitations of echocardiography in the diagnosis of PVE and the potential advantages of (18)F-FDG-PET-CT in these cases.

  9. Clinical Utility of Thallium-201 Single Photon Emission Computed Tomography and Cerebrospinal Fluid Epstein-Barr Virus Detection Using Polymerase Chain Reaction in the Diagnosis of AIDS-Related Primary Central Nervous System Lymphoma.

    PubMed

    Hussain, Fadilah S; Hussain, Namath S

    2016-05-10

    To determine the diagnostic efficiency of thallium-201 single photon emission computed tomography (SPECT) and Epstein-Barr virus (EBV) polymerase chain reaction (PCR) in the differentiation of primary central nervous system lymphoma (PCNSL) from other central nervous system processes in patients with HIV/AIDS. Over 10 years, 68 thallium-201 SPECT scans were performed on neurologically symptomatic HIV+ patients with focal lesions on CT or MRI at the Johns Hopkins Hospital. Diagnoses were then established by either autopsy, biopsy, or clinical response to anti-toxoplasmosis therapy. Patients were categorized prior to a prospective clinical reading of the SPECT scans by nuclear medicine physicians. In our patient sample overall, the diagnostic efficiency of thallium-201 SPECT was 79%. The diagnostic accuracy of EBV PCR testing alone in a subset of 22 patients in our study that had CSF analyzed was 73%. However, when both positive EBV PCR and positive thallium-201 SPECT results were used together, the diagnostic accuracy improved to 100% based on a sample of 13 patients where EBV PCR and SPECT imaging results were concordant.  Thallium-201 SPECT has a relatively high positive predictive value with regards to the diagnosis of PCNSL, which suggests that patients with positive results could undergo empiric radiation treatment without resorting to brain biopsy. However, the predictive value can be increased by testing for CSF EBV using PCR. Alternatively, if CSF cannot be safely obtained because of mass effect, we believe that these data still suggest that empiric radiation treatment should be considered when discussing treatment options with patients with a positive thallium-201 SPECT.

  10. Chronic thromboembolic pulmonary hypertension: Comparison of dual-energy computed tomography and single photon emission computed tomography in canines.

    PubMed

    Tang, Chun Xiang; Yang, Gui Fen; Schoepf, U Joseph; Han, Zong Hong; Qi, Li; Zhao, Yan E; Wu, Jiang; Zhou, Chang Sheng; Zhu, Hong; Stubenrauch, Andrew C; Mangold, Stefanie; Zhang, Long Jiang; Lu, Guang Ming

    2016-02-01

    To compare diagnostic accuracy between dual-energy CT lung perfused blood volume (Lung PBV) imaging and single photon emission computed tomography (SPECT) in detecting chronic thromboembolic pulmonary hypertension (CTEPH) with histopathological results as reference standard in a canine model. Eighteen CTEPH canines were included into this experimental study. All procedures including paracentesis, embolization, scanning, pressure measurement and feeding medicine were repeated each two weeks, until systolic/diastolic pressure in canines was ≥ 30/15 mm Hg or mean pulmonary artery pressure ≥ 20 mm Hg, and then sacrificed for histopathology examination. Two radiologists (readers 1 and 2) and two nuclear radiologists (readers 3 and 4) analyzed images of conventional CT pulmonary angiography in dual-energy CT mode, Lung PBV imaging and SPECT, respectively. The presence, numbers, and locations of pulmonary emboli (PE) were recorded on a per-lobe basis. Pathological examination was served as reference standard. Sensitivity, specificity and accuracy of Lung PBV and SPECT were calculated. Kappa statistics were used to quantify inter-reader agreement. With histopathological results as reference standard, the sensitivities of 72.2%, 78.8%, 81.2%, specificities of 75.9%, 87.5%, 84.8%, accuracies of 73.8%, 83.1%, 83.1%, for readers 1, 2 and both with Lung PBV, respectively. Readers 3, 4 and both had sensitivities of 14.3%, 25.7%, 33.3%, specificities of 90.0%, 86.7%, 93.3%, accuracies of 49.2%, 53.8%, 60.0% with SPECT for detecting CTEPH. Inter-reader agreements were good for dual-energy CT (kappa=0.662) and SPECT (k=0.706) for detecting CTEPH. Dual-energy CT had a higher accuracy to detect CTEPH than SPECT in this canine model study. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Super-resolution in respiratory synchronized positron emission tomography.

    PubMed

    Wallach, Daphné; Lamare, Frédéric; Kontaxakis, Giorgos; Visvikis, Dimitris

    2012-02-01

    Respiratory motion is a major source of reduced quality in positron emission tomography (PET). In order to minimize its effects, the use of respiratory synchronized acquisitions, leading to gated frames, has been suggested. Such frames, however, are of low signal-to-noise ratio (SNR) as they contain reduced statistics. Super-resolution (SR) techniques make use of the motion in a sequence of images in order to improve their quality. They aim at enhancing a low-resolution image belonging to a sequence of images representing different views of the same scene. In this work, a maximum a posteriori (MAP) super-resolution algorithm has been implemented and applied to respiratory gated PET images for motion compensation. An edge preserving Huber regularization term was used to ensure convergence. Motion fields were recovered using a B-spline based elastic registration algorithm. The performance of the SR algorithm was evaluated through the use of both simulated and clinical datasets by assessing image SNR, as well as the contrast, position and extent of the different lesions. Results were compared to summing the registered synchronized frames on both simulated and clinical datasets. The super-resolution image had higher SNR (by a factor of over 4 on average) and lesion contrast (by a factor of 2) than the single respiratory synchronized frame using the same reconstruction matrix size. In comparison to the motion corrected or the motion free images a similar SNR was obtained, while improvements of up to 20% in the recovered lesion size and contrast were measured. Finally, the recovered lesion locations on the SR images were systematically closer to the true simulated lesion positions. These observations concerning the SNR, lesion contrast and size were confirmed on two clinical datasets included in the study. In conclusion, the use of SR techniques applied to respiratory motion synchronized images lead to motion compensation combined with improved image SNR and contrast

  12. Simulation of emission tomography using grid middleware for distributed computing.

    PubMed

    Thomason, M G; Longton, R F; Gregor, J; Smith, G T; Hutson, R K

    2004-09-01

    SimSET is Monte Carlo simulation software for emission tomography. This paper describes a simple but effective scheme for parallel execution of SimSET using NetSolve, a client-server system for distributed computation. NetSolve (version 1.4.1) is "grid middleware" which enables a user (the client) to run specific computations remotely and simultaneously on a grid of networked computers (the servers). Since the servers do not have to be identical machines, computation may take place in a heterogeneous environment. To take advantage of diversity in machines and their workloads, a client-side scheduler was implemented for the Monte Carlo simulation. The scheduler partitions the total decay events by taking into account the inherent compute-speeds and recent average workloads, i.e., the scheduler assigns more decay events to processors expected to give faster service and fewer decay events to those expected to give slower service. When compute-speeds and sustained workloads are taken into account, the speed-up is essentially linear in the number of equivalent "maximum-service" processors. One modification in the SimSET code (version 2.6.2.3) was made to ensure that the total number of decay events specified by the user is maintained in the distributed simulation. No other modifications in the standard SimSET code were made. Each processor runs complete SimSET code for its assignment of decay events, independently of others running simultaneously. Empirical results are reported for simulation of a clinical-quality lung perfusion study.

  13. PDE regularization for Bayesian reconstruction of emission tomography

    NASA Astrophysics Data System (ADS)

    Wang, Zhentian; Zhang, Li; Xing, Yuxiang; Zhao, Ziran

    2008-03-01

    The aim of the present study is to investigate a type of Bayesian reconstruction which utilizes partial differential equations (PDE) image models as regularization. PDE image models are widely used in image restoration and segmentation. In a PDE model, the image can be viewed as the solution of an evolutionary differential equation. The variation of the image can be regard as a descent of an energy function, which entitles us to use PDE models in Bayesian reconstruction. In this paper, two PDE models called anisotropic diffusion are studied. Both of them have the characteristics of edge-preserving and denoising like the popular median root prior (MRP). We use PDE regularization with an Ordered Subsets accelerated Bayesian one step late (OSL) reconstruction algorithm for emission tomography. The OS accelerated OSL algorithm is more practical than a non-accelerated one. The proposed algorithm is called OSEM-PDE. We validated the OSEM-PDE using a Zubal phantom in numerical experiments with attenuation correction and quantum noise considered, and the results are compared with OSEM and an OS version of MRP (OSEM-MRP) reconstruction. OSEM-PDE shows better results both in bias and variance. The reconstruction images are smoother and have sharper edges, thus are more applicable for post processing such as segmentation. We validate this using a k-means segmentation algorithm. The classic OSEM is not convergent especially in noisy condition. However, in our experiment, OSEM-PDE can benefit from OS acceleration and keep stable and convergent while OSEM-MRP failed to converge.

  14. Alcohol ADME in Primates Studied with Positron Emission Tomography

    PubMed Central

    Li, Zizhong; Xu, Youwen; Warner, Don; Volkow, Nora D.

    2012-01-01

    Background and Purpose The sensitivity to the intoxicating effects of alcohol as well as its adverse medical consequences differ markedly among individuals, which reflects in part differences in alcohol's absorption, distribution, metabolism, and elimination (ADME) properties. The ADME of alcohol in the body and its relationship with alcohol's brain bioavailability, however, is not well understood. Experimental Approach The ADME of C-11 labeled alcohol, CH311CH2OH, 1 and C-11 and deuterium dual labeled alcohol, CH311CD2OH, 2 in baboons was compared based on the principle that C–D bond is stronger than C–H bond, thus the reaction is slower if C–D bond breaking occurs in a rate-determining metabolic step. The following ADME parameters in peripheral organs and brain were derived from time activity curve (TAC) of positron emission tomography (PET) scans: peak uptake (Cmax); peak uptake time (Tmax), half-life of peak uptake (T1/2), the area under the curve (AUC60min), and the residue uptake (C60min). Key Results For 1 the highest uptake occurred in the kidney whereas for 2 it occurred in the liver. A deuterium isotope effect was observed in the kidneys in both animals studied and in the liver of one animal but not the other. The highest uptake for 1 and 2 in the brain was in striatum and cerebellum but 2 had higher uptake than 1 in all brain regions most evidently in thalamus and cingulate. Alcohol's brain uptake was significantly higher when given intravenously than when given orally and also when the animal was pretreated with a pharmacological dose of alcohol. Conclusion and Implications The study shows that alcohol metabolism in peripheral organs had a large effect on alcohol's brain bioavailability. This study sets the stage for clinical investigation on how genetics, gender and alcohol abuse affect alcohol's ADME and its relationship to intoxication and medical consequences. PMID:23049712

  15. Averaging and Metropolis iterations for positron emission tomography.

    PubMed

    Szirmay-Kalos, László; Magdics, Milán; Tóth, Balázs; Bükki, Tamás

    2013-03-01

    Iterative positron emission tomography (PET) reconstruction computes projections between the voxel space and the lines of response (LOR) space, which are mathematically equivalent to the evaluation of multi-dimensional integrals. The dimension of the integration domain can be very high if scattering needs to be compensated. Monte Carlo (MC) quadrature is a straightforward method to approximate high-dimensional integrals. As the numbers of voxels and LORs can be in the order of hundred millions and the projection also depends on the measured object, the quadratures cannot be precomputed, but Monte Carlo simulation should take place on-the-fly during the iterative reconstruction process. This paper presents modifications of the maximum likelihood, expectation maximization (ML-EM) iteration scheme to reduce the reconstruction error due to the on-the-fly MC approximations of forward and back projections. If the MC sample locations are the same in every iteration step of the ML-EM scheme, then the approximation error will lead to a modified reconstruction result. However, when random estimates are statistically independent in different iteration steps, then the iteration may either diverge or fluctuate around the solution. Our goal is to increase the accuracy and the stability of the iterative solution while keeping the number of random samples and therefore the reconstruction time low. We first analyze the error behavior of ML-EM iteration with on-the-fly MC projections, then propose two solutions: averaging iteration and Metropolis iteration. Averaging iteration averages forward projection estimates during the iteration sequence. Metropolis iteration rejects those forward projection estimates that would compromise the reconstruction and also guarantees the unbiasedness of the tracer density estimate. We demonstrate that these techniques allow a significant reduction of the required number of samples and thus the reconstruction time. The proposed methods are built into

  16. Positron emission tomography: a financial and operational analysis.

    PubMed

    Conti, P S; Keppler, J S; Halls, J M

    1994-06-01

    Positron emission tomography (PET) is an emerging clinical imaging technique that is facing the challenges of expansion in a period of imminent health care contraction and reform. Although PET began showing utility in clinical medicine in the mid-1980s [1], its proliferation into mainstream medical practice has not matched that of other new imaging technologies such as MR imaging. Many factors have contributed to this, including the changing health care economy, the high cost of PET, the length of time it takes to develop a PET facility, and its inherent complexity. In part because of the proliferation of the use of other technologies and the general explosion of costs, insurance carriers are now holding diagnostic techniques, including PET, to stricter standards of efficacy. New techniques must show improvement in long-term outcome of patients, a difficult task for diagnostic tools. In addition to these issues, PET is an expensive technology that requires highly trained multidisciplinary personnel. Questions have also been raised about the most appropriate mechanism for regulation of PET isotope preparation, leading to speculation about future regulatory requirements. The current pioneers of PET must meet these challenges in order for it to become a routine imaging technique. Because of its clinical value, PET will probably survive despite the challenges. For many reasons, though, not every hospital should necessarily develop PET services. Conversely, many hospitals without this technology should consider acquiring PET. The purpose of this article is to identify the financial, operational, and clinical challenges facing PET centers today, describe potential organizational configurations that may enable PET to survive in an antitechnology environment, and delineate which institutions should consider this new technology.

  17. The Alzheimer's Disease Neuroimaging Initiative positron emission tomography core.

    PubMed

    Jagust, William J; Bandy, Dan; Chen, Kewei; Foster, Norman L; Landau, Susan M; Mathis, Chester A; Price, Julie C; Reiman, Eric M; Skovronsky, Daniel; Koeppe, Robert A

    2010-05-01

    This is a progress report of the Alzheimer's Disease Neuroimaging Initiative (ADNI) positron emission tomography (PET) Core. The Core has supervised the acquisition, quality control, and analysis of longitudinal [(18)F]fluorodeoxyglucose PET (FDG-PET) data in approximately half of the ADNI cohort. In an "add on" study, approximately 100 subjects also underwent scanning with [(11)C] Pittsburgh compound B PET for amyloid imaging. The Core developed quality control procedures and standardized image acquisition by developing an imaging protocol that has been widely adopted in academic and pharmaceutical industry studies. Data processing provides users with scans that have identical orientation and resolution characteristics despite acquisition on multiple scanner models. The Core labs have used many different approaches to characterize differences between subject groups (Alzheimer's disease, mild cognitive impairment, controls), to examine longitudinal change over time in glucose metabolism and amyloid deposition, and to assess the use of FDG-PET as a potential outcome measure in clinical trials. ADNI data indicate that FDG-PET increases statistical power over traditional cognitive measures, might aid subject selection, and could substantially reduce the sample size in a clinical trial. Pittsburgh compound B PET data showed expected group differences, and identified subjects with significant annual increases in amyloid load across the subject groups. The next activities of the PET core in ADNI will entail developing standardized protocols for amyloid imaging using the [(18)F]-labeled amyloid imaging agent AV45, which can be delivered to virtually all ADNI sites. ADNI has demonstrated the feasibility and utility of multicenter PET studies and is helping to clarify the role of biomarkers in the study of aging and dementia. Copyright 2010 The Alzheimer

  18. Positron emission tomography (PET) and macromolecular delivery in vivo.

    PubMed

    Strauss, Ludwig G; Dimitrakopoulou-Strauss, Antonia

    2009-01-01

    Positron emission tomography (PET) examinations with F-18-fluorodeoxyglucose (FDG) provide detailed information about the glucose-like metabolism in tissue. It is generally accepted that FDG reflects the viability of tumour cells. The kinetics of FDG is modulated by several genes, besides the glucose transporters and hexokinases. Additional specific information can be obtained non-invasively by using other tracers specific for cell membrane receptors. PET studies with radiolabelled peptides have emerged as a new diagnostic tool for imaging of certain tumour entities, like neuroendocrine tumours (NETs) and gastrointestinal stromal tumours (GISTs). This application is based on certain properties of these tumours, like the overexpression of somatostatin receptors, which can be visualised by somatostatin analogues, like 1,4,7,10-tetraazacyclododecane-N, N', N'', N'''-tetraacetic-acid-D: -Phe1-Tyr3 octreotide (DOTATOC) in NET. The overexpression of gastrin-releasing peptide (GRP) receptors can be visualised in GIST by using bombesin analogues. These peptides can be labelled by (68)Ga, which is a generator product and therefore more cost-effective than cyclotron products. (68)Ga-DOTATOC is a peptide that binds primarily to somatostatin receptor subtype 2 (SSTR2). PET studies with (68)Ga-DOTATOC are performed in patients with NET and some other tumours. (68)Ga-BZH3 ((68)Ga-Bombesin) is a peptide that binds to at least three bombesin receptor subtypes: the BB1 (also known as neuromedin B), the BB2 (also known as GRP), and the BB3 (bombesin receptor subtype 3). This bombesin analogue, (68)Ga-BZH3, is used in patients with GIST.

  19. Ictal single photon emission computed tomography of myoclonic absence seizures.

    PubMed

    Ikeda, Hiroko; Imai, Katsumi; Ikeda, Hitoshi; Matsuda, Kazumi; Takahashi, Yukitoshi; Inoue, Yushi

    2017-08-16

    Epilepsy with myoclonic absences (EMAs) is a rare epileptic disorder characterized by a predominant type of seizures, myoclonic absences (MAs). The pathophysiology of MAs in patients with EMAs remains unknown. Here, we report the first characterization of the ictal phase of MAs by single photon emission computed tomography (SPECT). We evaluated 1 male (Patient 1) and 1 female (Patient 2) patient with EMAs, aged 8 and 4years at first SPECT investigation, respectively. We performed ictal and interictal (99 m)Tc-ethyl cysteinate dimer (ECD) SPECT. We then generated images of subtraction ictal SPECT co-registered to MRI (SISCOM) from the interictal and ictal data to evaluate topographic changes in cerebral blood flow (CBF) during MAs as compared to the interictal state. In Patient 1, the CBF increased in the perirolandic areas, thalamus, caudate nucleus, and precuneus, and decreased in the middle frontal gyrus and bilateral orbitofrontal regions. In Patient 2, CBF increased in the thalamus, putamen, and globus pallidus. In contrast to the CBF in Patient 1, CBF was decreased in the precuneus. Using SPECT, we showed that, in addition to the thalamus and basal ganglia, the perirolandic cortical motor area is involved in MAs. We hypothesize that in MAs the blood perfusion in the perirolandic cortical motor area might have changed under the influence of the cortico-thalamic network oscillation features. The CBF properties observed by means of our SPECT procedure may represent key features of the pathophysiological mechanisms underlying MAs. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  20. Nonhuman primate positron emission tomography neuroimaging in drug abuse research.

    PubMed

    Howell, Leonard Lee; Murnane, Kevin Sean

    2011-05-01

    Positron emission tomography (PET) neuroimaging in nonhuman primates has led to significant advances in our current understanding of the neurobiology and treatment of stimulant addiction in humans. PET neuroimaging has defined the in vivo biodistribution and pharmacokinetics of abused drugs and related these findings to the time course of behavioral effects associated with their addictive properties. With novel radiotracers and enhanced resolution, PET neuroimaging techniques have also characterized in vivo drug interactions with specific protein targets in the brain, including neurotransmitter receptors and transporters. In vivo determinations of cerebral blood flow and metabolism have localized brain circuits implicated in the effects of abused drugs and drug-associated stimuli. Moreover, determinations of the predisposing factors to chronic drug use and long-term neurobiological consequences of chronic drug use, such as potential neurotoxicity, have led to novel insights regarding the pathology and treatment of drug addiction. However, similar approaches clearly need to be extended to drug classes other than stimulants. Although dopaminergic systems have been extensively studied, other neurotransmitter systems known to play a critical role in the pharmacological effects of abused drugs have been largely ignored in nonhuman primate PET neuroimaging. Finally, the study of brain activation with PET neuroimaging has been replaced in humans mostly by functional magnetic resonance imaging (fMRI). There has been some success in implementing pharmacological fMRI in awake nonhuman primates. Nevertheless, the unique versatility of PET imaging will continue to complement the systems-level strengths of fMRI, especially in the context of nonhuman primate drug abuse research.

  1. Usefulness of Positron Emission Tomography in Patients with Syphilis: A Systematic Review of Observational Studies.

    PubMed

    Chen, Jian-Hua; Zheng, Xin; Liu, Xiu-Qin

    2017-05-05

    Diagnosis of syphilis is difficult. Follow-up and therapy evaluation of syphilitic patients are poor. Little is known about positron emission tomography (PET) in syphilis. This review was to systematically review usefulness of PET for diagnosis, disease extent evaluation, follow-up, and treatment response assessment in patients with syphilis. We searched PubMed, EMBASE, SCOPUS, Cochrane Library, Web of Science, ClinicalTrials.gov, and three Chinese databases (SinoMed, Wanfang, and CNKI) for English and Chinese language articles from inception to September 2016. We also collected potentially relevant studies and reviews using a manual search. The search keywords included the combined text and MeSH terms "syphilis" and "positron emission tomography". We included studies that reporting syphilis with a PET scan before and/or after antibiotic treatment. The diagnosis of syphilis was based on serological criteria or dark field microscopy. Outcomes include pre- and post-treatment PET scan, pre- and post-treatment computed tomography, and pre- and post-treatment magnetic resonance imaging. We excluded the articles not published in English or Chinese or not involving humans. Of 258 identified articles, 34 observational studies were included. Thirty-three studies were single-patient case reports and one study was a small case series. All patients were adults. The mean age of patients was 48.3 ± 12.1 years. In primary syphilis, increased fluorodeoxyglucose (FDG) accumulation could be seen at the site of inoculation or in the regional lymph nodes. In secondary syphilis with lung, bone, gastrointestinal involvement, or generalized lymphadenopathy, increased FDG uptake was the most commonly detected changes. In tertiary syphilis, increased glucose metabolic activity, hypometabolic lesions, or normal glucose uptake might be seen on PET. There were five types of PET scans in neurosyphilis. A repeated PET scan after treatment revealed apparent or complete resolution of the

  2. Contrast-enhanced fluorodeoxyglucose positron emission tomography/contrast-enhanced computed tomography in mediastinal T-cell lymphoma with superior vena cava syndrome.

    PubMed

    Santhosh, Sampath; Gorla, Arun Kumar Reddy; Bhattacharya, Anish; Varma, Subhash Chander; Mittal, Bhagwant Rai

    2016-01-01

    Positron emission tomography-computed tomography (PET/CT) is a routine investigation for the staging of lymphomas. Contrast-enhanced computed tomography is mandatory whenever parenchymal lesions, especially in the liver and spleen are suspected. We report a rare case of primary mediastinal T-cell lymphoma evaluated with contrast-enhanced PET/CT that showed features of superior vena cava syndrome.

  3. High-resolution PET [Positron Emission Tomography] for Medical Science Studies

    DOE R&D Accomplishments Database

    Budinger, T. F.; Derenzo, S. E.; Huesman, R. H.; Jagust, W. J.; Valk, P. E.

    1989-09-01

    One of the unexpected fruits of basic physics research and the computer revolution is the noninvasive imaging power available to today's physician. Technologies that were strictly the province of research scientists only a decade or two ago now serve as the foundations for such standard diagnostic tools as x-ray computer tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), ultrasound, single photon emission computed tomography (SPECT), and positron emission tomography (PET). Furthermore, prompted by the needs of both the practicing physician and the clinical researcher, efforts to improve these technologies continue. This booklet endeavors to describe the advantages of achieving high resolution in PET imaging.

  4. High-resolution PET (positron emission tomography) for medical science studies

    SciTech Connect

    Budinger, T.F.; Derenzo, S.E.; Huesman, R.H.; Jagust, W.J.; Valk, P.E. )

    1989-09-01

    One of the unexpected fruits of basic physics research and the computer revolution is the noninvasive imaging power available to today's physician. Technologies that were strictly the province of research scientists only a decade or two ago now serve as the foundations for such standard diagnostic tools as x-ray computer tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), ultrasound, single photon emission computed tomography (SPECT), and positron emission tomography (PET). Furthermore, prompted by the needs of both the practicing physician and the clinical researcher, efforts to improve these technologies continue. This booklet endeavors to describe the advantages of achieving high resolution in PET imaging. 6 refs., 21 figs.

  5. Budget impact from the incorporation of positron emission tomography – computed tomography for staging lung cancers

    PubMed Central

    Biz, Aline Navega; Caetano, Rosângela

    2015-01-01

    OBJECTIVE To estimate the budget impact from the incorporation of positron emission tomography (PET) in mediastinal and distant staging of non-small cell lung cancer. METHODS The estimates were calculated by the epidemiological method for years 2014 to 2018. Nation-wide data were used about the incidence; data on distribution of the disease´s prevalence and on the technologies’ accuracy were from the literature; data regarding involved costs were taken from a micro-costing study and from Brazilian Unified Health System (SUS) database. Two strategies for using PET were analyzed: the offer to all newly-diagnosed patients, and the restricted offer to the ones who had negative results in previous computed tomography (CT) exams. Univariate and extreme scenarios sensitivity analyses were conducted to evaluate the influence from sources of uncertainties in the parameters used. RESULTS The incorporation of PET-CT in SUS would imply the need for additional resources of 158.1 BRL (98.2 USD) million for the restricted offer and 202.7 BRL (125.9 USD) million for the inclusive offer in five years, with a difference of 44.6 BRL (27.7 USD) million between the two offer strategies within that period. In absolute terms, the total budget impact from its incorporation in SUS, in five years, would be 555 BRL (345 USD) and 600 BRL (372.8 USD) million, respectively. The costs from the PET-CT procedure were the most influential parameter in the results. In the most optimistic scenario, the additional budget impact would be reduced to 86.9 BRL (54 USD) and 103.8 BRL (64.5 USD) million, considering PET-CT for negative CT and PET-CT for all, respectively. CONCLUSIONS The incorporation of PET in the clinical staging of non-small cell lung cancer seems to be financially feasible considering the high budget of the Brazilian Ministry of Health. The potential reduction in the number of unnecessary surgeries may cause the available resources to be more efficiently allocated. PMID:26274871

  6. Does positron emission tomography/computed tomography aid the diagnosis of prosthetic valve infective endocarditis?

    PubMed

    Balmforth, Damian; Chacko, Jacob; Uppal, Rakesh

    2016-10-01

    A best evidence topic was constructed according to a structured protocol. The question addressed was whether (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) aids the diagnosis of prosthetic valve endocarditis (PVE)? A total of 107 publications were found using the reported search, of which 6 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The reported outcome of all studies was a final diagnosis of confirmed endocarditis on follow-up. All the six studies were non-randomized, single-centre, observational studies and thus represented level 3 evidence. The diagnostic capability of PET/CT for PVE was compared with that of the modified Duke Criteria and echocardiography, and reported in terms of sensitivity, specificity and positive and negative predictive values. All studies demonstrated an increased sensitivity for the diagnosis of PVE when PET/CT was combined with the modified Duke Criteria on admission. A higher SUVmax on PET was found to be significantly associated with a confirmed diagnosis of endocarditis and an additional diagnostic benefit of PET/CT angiography over conventional PET/non-enhanced CT is reported due to improved anatomical resolution. However, PET/CT was found to be unreliable in the early postoperative period due to its inability to distinguish between infection and residual postoperative inflammatory changes. PET/CT was also found to be poor at diagnosing cases of native valve endocarditis. We conclude that PET/CT aids in the diagnosis of PVE when combined with the modified Duke Criteria on admission by increasing the diagnostic sensitivity. The diagnostic ability of PET/CT can be potentiated by the use of PET/CTA; however, its use may be unreliable in the early postoperative period or in native valve endocarditis. © The Author 2016. Published by

  7. Positron Emission Tomography-Determined Hyperemic Flow, Myocardial Flow Reserve, and Flow Gradient—Quo Vadis?

    PubMed Central

    Leucker, Thorsten M.; Valenta, Ines; Schindler, Thomas Hellmut

    2017-01-01

    Positron emission tomography/computed tomography (PET/CT) applied with positron-emitting flow tracers such as 13N-ammonia and 82Rubidium enables the quantification of both myocardial perfusion and myocardial blood flow (MBF) in milliliters per gram per minute for coronary artery disease (CAD) detection and characterization. The detection of a regional myocardial perfusion defect during vasomotor stress commonly identifies the culprit lesion or most severe epicardial narrowing, whereas adding regional hyperemic MBFs, myocardial flow reserve (MFR), and/or longitudinal flow decrease may also signify less severe but flow-limiting stenosis in multivessel CAD. The addition of regional hyperemic flow parameters, therefore, may afford a comprehensive identification and characterization of flow-limiting effects of multivessel CAD. The non-specific origin of decreases in hyperemic MBFs and MFR, however, prompts an evaluation and interpretation of regional flow in the appropriate context with the presence of obstructive CAD. Conversely, initial results of the assessment of a longitudinal hyperemic flow gradient suggest this novel flow parameter to be specifically related to increases in CAD caused epicardial resistance. The concurrent assessment of myocardial perfusion and several hyperemic flow parameters with PET/CT may indeed open novel avenues of precision medicine to guide coronary revascularization procedures that may potentially lead to a further improvement in cardiovascular outcomes in CAD patients. PMID:28770213

  8. Clinical Utility of Positron Emission Tomography Magnetic Resonance Imaging (PET-MRI) in Gastrointestinal Cancers

    PubMed Central

    Matthews, Robert; Choi, Minsig

    2016-01-01

    Anatomic imaging utilizing both CT (computed tomography) and MRI (magnetic resonance imaging) limits the assessment of cancer metastases in lymph nodes and distant organs while functional imaging like PET (positron emission tomography) scan has its limitation in spatial resolution capacity. Hybrid imaging utilizing PET-CT and PET-MRI are novel imaging modalities that are changing the current landscape in cancer diagnosis, staging, and treatment response. MRI has shown to have higher sensitivity in soft tissue, head and neck pathology, and pelvic disease, as well as, detecting small metastases in the liver and bone compared to CT. Combining MRI with PET allows for detection of metastases that may have been missed with current imaging modalities. In this review, we will examine the clinical utility of FDG PET-MRI in the diagnosis and staging of gastrointestinal cancers with focus on esophageal, stomach, colorectal, and pancreatic cancers. We will also explore its role in treatment response and future directions associated with it. PMID:27618106

  9. 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography for Other Thyroid Cancers: Medullary, Anaplastic, Lymphoma and So Forth

    PubMed Central

    Araz, Mine; Çayır, Derya

    2017-01-01

    Positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose (FDG) is used in staging, restaging, and evaluation of therapy response in many cancers as well as differentiated thyroid carcinomas especially in non-iodine avid variants. Its potential in less frequent thyroid tumors like medullary, anaplastic thyroid cancers, thyroid lymphoma and metastatic tumors of the thyroid however, is not well established yet. The aim of this review is to provide an overview on the recent applications and indications of 18F-FDG PET/CT in these tumors and to focus on the controversies in the clinical setting. PMID:28291004

  10. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in a rare case of carcinoma stomach with concomitant silicosis

    PubMed Central

    Sasikumar, Arun; Joy, Ajith; Unni, Madhavan; Madhavan, Jayaprakash

    2016-01-01

    The role of fluorine-18 fluorodeoxyglucose. (18F-FDG) positron emission tomography. (PET)/computed tomography. (CT) in the initial staging of various malignancies is now well established. However, nonspecificity of FDG occasionally results in tracer uptake in benign lung lesions. The authors describe a complicated case of carcinoma stomach with multiple nodules and a cavitary lesion in lungs where 18F-FDG PET CT done for initial staging revealed FDG avid mass in stomach, FDG avid multiple mediastinal lymph nodes and multiple intensely FDG avid bilateral lung lesions. The FDG avid lung lesions turned out to be due to silicosis as confirmed by histopathology. PMID:27833322

  11. Comparison of diffuse optical tomography of human breast with whole-body and breast-only positron emission tomography

    PubMed Central

    Konecky, Soren D.; Choe, Regine; Corlu, Alper; Lee, Kijoon; Wiener, Rony; Srinivas, Shyam M.; Saffer, Janet R.; Freifelder, Richard; Karp, Joel S.; Hajjioui, Nassim; Azar, Fred; Yodh, Arjun G.

    2008-01-01

    We acquire and compare three-dimensional tomographic breast images of three females with suspicious masses using diffuse optical tomography (DOT) and positron emission tomography (PET). Co-registration of DOT and PET images was facilitated by a mutual information maximization algorithm. We also compared DOT and whole-body PET images of 14 patients with breast abnormalities. Positive correlations were found between total hemoglobin concentration and tissue scattering measured by DOT, and fluorodeoxyglucose (18F-FDG) uptake. In light of these observations, we suggest potential benefits of combining both PET and DOT for characterization of breast lesions. PMID:18383664

  12. Comparison of diffuse optical tomography of human breast with whole-body and breast-only positron emission tomography.

    PubMed

    Konecky, Soren D; Choe, Regine; Corlu, Alper; Lee, Kijoon; Wiener, Rony; Srinivas, Shyam M; Saffer, Janet R; Freifelder, Richard; Karp, Joel S; Hajjioui, Nassim; Azar, Fred; Yodh, Arjun G

    2008-02-01

    We acquire and compare three-dimensional tomographic breast images of three females with suspicious masses using diffuse optical tomography (DOT) and positron emission tomography (PET). Co-registration of DOT and PET images was facilitated by a mutual information maximization algorithm. We also compared DOT and whole-body PET images of 14 patients with breast abnormalities. Positive correlations were found between total hemoglobin concentration and tissue scattering measured by DOT, and fluorodeoxyglucose (18F-FDG) uptake. In light of these observations, we suggest potential benefits of combining both PET and DOT for characterization of breast lesions.

  13. Incremental value of single photon emission tomography/computed tomography in 3-phase bone scintigraphy of an accessory navicular bone.

    PubMed

    Jain, Sachin; Karunanithi, Sellam; Agarwal, Krishan Kant; Kumar, Ganesh; Roy, Shambo Guha; Tripathi, Madhavi

    2014-07-01

    Accessory navicular bone is one of the supernumerary ossicles in the foot. Radiography is non diagnostic in symptomatic cases. Accessory navicular has been reported as a cause of foot pain and is usually associated with flat foot. Increased radio tracer uptake on bone scan is found to be more sensitive. We report a case highlighting the significance of single photon emission tomography/computed tomography in methylene diphosphonate bone scan in the evaluation of symptomatic accessory navicular bone where three phase bone scan is equivocal.

  14. Incremental value of single photon emission tomography/computed tomography in 3-phase bone scintigraphy of an accessory navicular bone

    PubMed Central

    Jain, Sachin; Karunanithi, Sellam; Agarwal, Krishan Kant; Kumar, Ganesh; Roy, Shambo Guha; Tripathi, Madhavi

    2014-01-01

    Accessory navicular bone is one of the supernumerary ossicles in the foot. Radiography is non diagnostic in symptomatic cases. Accessory navicular has been reported as a cause of foot pain and is usually associated with flat foot. Increased radio tracer uptake on bone scan is found to be more sensitive. We report a case highlighting the significance of single photon emission tomography/computed tomography in methylene diphosphonate bone scan in the evaluation of symptomatic accessory navicular bone where three phase bone scan is equivocal. PMID:25210293

  15. Metastatic superscan in prostate carcinoma on gallium-68-prostate-specific membrane antigen positron emission tomography/computed tomography scan.

    PubMed

    Agarwal, Krishan Kant; Tripathi, Madhavi; Kumar, Rajeev; Bal, Chandrasekhar

    2016-01-01

    We describe the imaging features of a metastatic superscan on gallium-68 Glu-NH-CO-NH-Lys-(Ahx)-[Ga-68(HBED-CC)], abbreviated as gallium-68-prostate-specific membrane antigen ((68)Ga-PSMA) positron emission tomography/computed tomography (PET/CT) imaging. (68)Ga-PSMA is novel radiotracer undergoing evaluation for PET/CT imaging of prostate carcinoma. This patient had a superscan of metastases on conventional bone scintigraphy and was referred for (68)Ga-PSMA PET/CT to evaluate the feasibility of (177)Lu-PSMA therapy.

  16. Iodine-131 meta-iodobezylguanidine single photon emission computed tomography/computerized tomography in diagnosis of neuro-endocrine tumors

    PubMed Central

    Harisankar, Chidambaram Natrajan Balasubramanian; Mittal, Bhagwant Rai; Bhattacharya, Anish; Kashyap, Raghava; Bhansali, Anil

    2012-01-01

    Metaiodobenzyl guanidine (MIBG) is a derivative of guanethidine and acts as an analogue of nor-epinephrine and is widely used in the imaging of tumors of neuro-endocrine origin. Iodine-123 MIBG has ideal imaging characteristics but is expensive with limited availability. Iodine-131 MIBG is widely used in India and is cheap. Hybrid single photon emission computed tomography (SPECT)/computerized tomography (CT) allows for anatomico-functional imaging and is being tried in MIBG studies. However, the experience with I-131 MIBG is limited. We present a pictorial assay of I-131 MIBG SPECT/CT findings in various MIBG avid tumors. PMID:23599604

  17. Role of F18 fluorodeoxyglucose positron-emission tomography/computed tomography in the management of Askin's tumor.

    PubMed

    Santhosh, Sampath; Kashyap, Raghava; Bhattacharya, Anish; Kumar Jindal, Surinder; Rai Mittal, Bhagwant

    2013-07-01

    A primitive neuroectodermal tumor (PNET) of the thoraco-abdominal region is one of a group of small round cell tumors usually found in children and young adults, originally described by Askin et al. Most cases arise in the soft-tissues of the thorax, but may rarely occur within the lung with the symptoms of chest wall pain, pleural effusion and dyspnea. The authors present two cases demonstrating the utility of F18 fluorodeoxyglucose positron-emission tomography/computed tomography in the staging and prognosis of PNET of the chest wall.

  18. Positron Emission Tomography/Magnetic Resonance Imaging for Local Tumor Staging in Patients With Primary Breast Cancer: A Comparison With Positron Emission Tomography/Computed Tomography and Magnetic Resonance Imaging.

    PubMed

    Grueneisen, Johannes; Nagarajah, James; Buchbender, Christian; Hoffmann, Oliver; Schaarschmidt, Benedikt Michael; Poeppel, Thorsten; Forsting, Michael; Quick, Harald H; Umutlu, Lale; Kinner, Sonja

    2015-08-01

    This study aimed to assess the diagnostic performance of integrated positron emission tomography (PET)/magnetic resonance imaging (MRI) of the breast for lesion detection and local tumor staging of patients with primary breast cancer in comparison to PET/computed tomography (CT) and MRI. The study was approved by the local institutional review board. Forty-nine patients with biopsy-proven invasive breast cancer were prospectively enrolled in our study. All patients underwent a PET/CT, and subsequently, a contrast-enhanced PET/MRI of the breast after written informed consent was obtained before each examination. Two radiologists independently evaluated the corresponding data sets (PET/CT, PET/MRI, and MRI) and were instructed to identify primary tumors lesions as well as multifocal/multicentric and bilateral disease. Furthermore, the occurrence of lymph node metastases was assessed, and the T-stage for each patient was determined. Histopathological verification of the local tumor extent and the axillary lymph node status was available for 30 of 49 and 48 of 49 patients, respectively. For the remaining patients, a consensus characterization was performed for the determination of the T-stage and nodal status, taking into account the results of clinical staging, PET/CT, and PET/MRI examinations. Statistical analysis was performed to test for differences in diagnostic performance between the different imaging procedures. P values less than 0.05 were considered to be statistically significant. Positron emission tomography/MRI and MRI correctly identified 47 (96%) of the 49 patients with primary breast cancer, whereas PET/CT enabled detection of 46 (94%) of 49 breast cancer patients and missed a synchronous carcinoma in the contralateral breast in 1 patient. In a lesion-by-lesion analysis, no significant differences could be obtained between the 3 imaging procedures for the identification of primary breast cancer lesions (P > 0.05). Positron emission tomography/MRI and

  19. Simulation Study of Single Photon Emission Computed Tomography for Industrial Applications

    SciTech Connect

    Roy, Tushar; Sarkar, P. S.; Sinha, Amar

    2008-09-26

    SPECT (Single Photon Emission Computed Tomography) provides for an invaluable non-invasive technique for the characterization and activity distribution of the gamma-emitting source. For many applications of radioisotopes for medical and industrial application, not only the positional information of the distribution of radioisotopes is needed but also its strength. The well-established X-ray radiography or transmission tomography techniques do not yield sufficient quantitative information about these objects. Emission tomography is one of the important methods for such characterization. Application of parallel beam, fan beam and 3D cone beam emission tomography methods have been discussed in this paper. Simulation studies to test these algorithms have been carried out to validate the technique.

  20. Fingerprint fake detection by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Meissner, Sven; Breithaupt, Ralph; Koch, Edmund

    2013-03-01

    The most established technique for the identification at biometric access control systems is the human fingerprint. While every human fingerprint is unique, fingerprints can be faked very easily by using thin layer fakes. Because commercial fingerprint scanners use only a two-dimensional image acquisition of the finger surface, they can only hardly differentiate between real fingerprints and fingerprint fakes applied on thin layer materials. A Swept Source OCT system with an A-line rate of 20 kHz and a lateral and axial resolution of approximately 13 μm, a centre wavelength of 1320 nm and a band width of 120 nm (FWHM) was used to acquire fingerprints and finger tips with overlying fakes. Three-dimensional volume stacks with dimensions of 4.5 mm x 4 mm x 2 mm were acquired. The layering arrangement of the imaged finger tips and faked finger tips was analyzed and subsequently classified into real and faked fingerprints. Additionally, sweat gland ducts were detected and consulted for the classification. The manual classification between real fingerprints and faked fingerprints results in almost 100 % correctness. The outer as well as the internal fingerprint can be recognized in all real human fingers, whereby this was not possible in the image stacks of the faked fingerprints. Furthermore, in all image stacks of real human fingers the sweat gland ducts were detected. The number of sweat gland ducts differs between the test persons. The typical helix shape of the ducts was observed. In contrast, in images of faked fingerprints we observe abnormal layer arrangements and no sweat gland ducts connecting the papillae of the outer fingerprint and the internal fingerprint. We demonstrated that OCT is a very useful tool to enhance the performance of biometric control systems concerning attacks by thin layer fingerprint fakes.

  1. (18) F-sodium fluoride positron emission tomography of the equine distal limb: Exploratory study in three horses.

    PubMed

    Spriet, M; Espinosa, P; Kyme, A Z; Phillips, K L; Katzman, S A; Galuppo, L D; Stepanov, P; Beylin, D

    2017-07-14

    Positron emission tomography (PET) is a cross-sectional, functional imaging modality that has recently become available to the horse. The use of (18) F-sodium fluoride ((18) F-NaF), a PET bone tracer, has not previously been reported in this species. To assess the feasibility of (18) F-NaF PET in the equine distal limb and explore possible applications in the horse in comparison with other imaging modalities. Exploratory descriptive study involving three research horses. Horses were placed under general anaesthesia prior to intravenous (i.v.) administration of 1.5 MBq/kg of (18) F-NaF. Positron emission tomography imaging of both front feet and fetlocks was performed using a portable scanner. Computed tomography (CT) of the distal limb was performed under a separate anaesthetic episode. Bone scintigraphy and magnetic resonance imaging (MRI) were subsequently performed under standing sedation. Images obtained from PET and other imaging modalities were independently assessed and the results correlated. Positron emission tomography images were obtained without complication. The radiation exposure rate was similar to equine bone scintigraphy. Positron emission tomography detected focal (18) F-NaF uptake in areas where other imaging modalities did not identify any abnormalities. This included sites of ligamentous attachment, subchondral compact bone plate and the flexor cortex of the navicular bone. (18) F-NaF uptake was identified in some, but not all, osseous fragments and areas of osseous formation, suggesting a distinction between active and inactive lesions. A small number of horses were included and histopathology was not available. (18) F-NaF PET imaging of the equine distal limb provides useful additional information when compared with CT, MRI and scintigraphy and has the potential for both research and clinical applications in the horse. The Summary is available in Chinese - see Supporting information. © 2017 EVJ Ltd.

  2. Paraneoplastic syndrome turned out to be non-Hodgkin's lymphoma on 18F-fluorodeoxyglucose positron emission tomography/computed tomography

    PubMed Central

    Sahoo, Manas Kumar; Arunraj, S. T.; Srivastava, Achal Kumar; Sahoo, Ranjit Kumar; Kumar, Rakesh; Bal, Chandrasekhar

    2016-01-01

    Paraneoplastic neurological syndromes (PNSs) are commonly encountered with underlying malignant pathology. Though anti--neuronal antibodies play a major role in the diagnosis of the underlying malignant pathology but at many times it becomes inconclusive. As early detection of the primary cause and its treatment gives the best result in such situations, there arises an early and accurate diagnostic need. We present a 65--year--old patient presenting with rapidly progressive quadriparesis with both distal and proximal involvement. With all routine work--up tests within normal limits, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) was done which revealed multiple findings that suggested a diagnosis of lymphoma. In our case, PET/CT proved to be an important modality for finding the underlying malignant pathology in a suspected case of PNS. PMID:27833317

  3. Comparison of single-photon emission computed tomography with (123I)iodoamphetamine and xenon-enhanced computed tomography for assessing regional cerebral blood flow

    SciTech Connect

    Hellman, R.S.; Collier, B.D.; Tikofsky, R.S.; Kilgore, D.P.; Daniels, D.L.; Haughton, V.M.; Walsh, P.R.; Cusick, J.F.; Saxena, V.K.; Palmer, D.W.

    1986-12-01

    Regional CBF (rCBF) images obtained from xenon-enhanced computed tomography (XeCT) and single-photon emission computed tomography (SPECT) with N-isopropyl-p-(/sup 123/I)iodoamphetamine (IMP) done with a rotating gamma-camera were compared in nine patients. Both XeCT and SPECT/IMP demonstrated flow abnormalities at all sites of infarction identified by CT, while detecting reduced rCBF in areas normal by CT in eight of the nine patients. All areas that were abnormal on XeCT were abnormal on the comparable SPECT/IMP images. The major advantages of XeCT are its greater resolution and potential for noninvasive quantitation of rCBF, while the major advantage of SPECT/IMP is its visualization of the entire brain on transverse, coronal, and sagittal sections.

  4. Paraneoplastic syndrome turned out to be non-Hodgkin's lymphoma on (18)F-fluorodeoxyglucose positron emission tomography/computed tomography.

    PubMed

    Sahoo, Manas Kumar; Arunraj, S T; Srivastava, Achal Kumar; Sahoo, Ranjit Kumar; Kumar, Rakesh; Bal, Chandrasekhar

    2016-01-01

    Paraneoplastic neurological syndromes (PNSs) are commonly encountered with underlying malignant pathology. Though anti--neuronal antibodies play a major role in the diagnosis of the underlying malignant pathology but at many times it becomes inconclusive. As early detection of the primary cause and its treatment gives the best result in such situations, there arises an early and accurate diagnostic need. We present a 65--year--old patient presenting with rapidly progressive quadriparesis with both distal and proximal involvement. With all routine work--up tests within normal limits, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) was done which revealed multiple findings that suggested a diagnosis of lymphoma. In our case, PET/CT proved to be an important modality for finding the underlying malignant pathology in a suspected case of PNS.

  5. Enhancement of molecular sensitivity in positron emission tomography with quantum correlation of γ-ray photons

    SciTech Connect

    Sato, K.; Kobayashi, Y.

    2015-05-15

    Enhancement of molecular sensitivity in positron emission tomography (PET) has long been discussed with respect to imaging instrumentation and algorithms for data treatment. Here, the molecular sensitivity in PET is discussed on the basis of 2-dimensional coincident measurements of 511 keV γ ray photons resultant from two-photon annihilation. Introduction of an additional selection window based on the energy sum and difference of the coincidently measured γ ray photons, without any significant instrumental and algorithmic changes, showed an improvement in the signal-to-noise ratio (SNR) by an order of magnitude. Improvement of performance characteristics in the PET imaging system was demonstrated by an increase in the noise equivalent count rate (NECR) which takes both the SNR and the detection efficiency into consideration. A further improvement of both the SNR and the NECR is expected for the present system in real clinical and in-vivo environments, where much stronger positron sources are employed.

  6. Enhancement of molecular sensitivity in positron emission tomography with quantum correlation of γ-ray photons.

    PubMed

    Sato, K; Kobayashi, Y

    2015-05-01

    Enhancement of molecular sensitivity in positron emission tomography (PET) has long been discussed with respect to imaging instrumentation and algorithms for data treatment. Here, the molecular sensitivity in PET is discussed on the basis of 2-dimensional coincident measurements of 511 keV γ ray photons resultant from two-photon annihilation. Introduction of an additional selection window based on the energy sum and difference of the coincidently measured γ ray photons, without any significant instrumental and algorithmic changes, showed an improvement in the signal-to-noise ratio (SNR) by an order of magnitude. Improvement of performance characteristics in the PET imaging system was demonstrated by an increase in the noise equivalent count rate (NECR) which takes both the SNR and the detection efficiency into consideration. A further improvement of both the SNR and the NECR is expected for the present system in real clinical and in-vivo environments, where much stronger positron sources are employed.

  7. Neutron Stimulated Emission Computed Tomography: A New Technique for Spectroscopic Medical Imaging

    NASA Astrophysics Data System (ADS)

    Kapadia, A. J.

    Neutron stimulated emission computed tomography (NSECT) is being developed as a new medical-imaging technique to quantify spatial distributions of elements in a sample through inelastic scattering of fast neutrons and detection of the resulting gamma rays. It has the potential to diagnose several disorders in the human body that are characterized by changes in element concentration in the diseased tissue. NSECT is sensitive to several naturally occurring elements in the human body that demonstrate concentration changes in the presence of diseases. NSECT, therefore, has the potential to noninvasively diagnose such disorders with radiation dose that is comparable to other ionizing imaging modalities. This chapter discusses the development and progress of NSECT and presents an overview of the current status of the imaging technique.

  8. The impact of positron emission tomography imaging on the clinical management of patients with epilepsy.

    PubMed

    Juhász, Csaba

    2012-06-01

    Clinical positron emission tomography (PET) imaging of human epilepsy has a 30-year history, but it is still searching for its exact role among rapidly advancing neuroimaging techniques. The vast majority of epilepsy PET studies used this technique to improve detection of epileptic foci for surgical resection. Here, we review the main trends emerging from three decades of PET research in epilepsy, with a particular emphasis on how PET imaging has impacted on the clinical management of patients with intractable epilepsy. While reviewing the latest studies, we also present an argument for a changing role of PET and molecular imaging in the future, with an increasing focus on epileptogenesis and newly discovered molecular mechanisms of epilepsy. These new applications will be facilitated by technological advances, such as the use of integrated PET/MRI systems and utilization of novel radiotracers, which may also enhance phenotype-genotype correlations and assist rational, individualized treatment strategies.

  9. Effect of gender on glucose utilization rates in healthy humans: A positron emission tomography study

    SciTech Connect

    Miura, S.A.; Schapiro, M.B.; Grady, C.L.; Kumar, A.; Salerno, J.A.; Kozachuk, W.E.; Wagner, E.; Rapoport, S.I.; Horwitz, B. )

    1990-12-01

    Positron emission tomography (PET) was used with 18fluorodeoxyglucose to see if gender differences in resting cerebral glucose utilization could be detected. Thirty-two healthy subjects (15 women and 17 men; age range: 21-38 yr) were examined using a high-resolution PET scanner to determine the regional cerebral metabolic rate for glucose (CMRglc) in 65 gray matter regions of interest. Whole brain CMRglc did not differ significantly between the two genders, nor did any of the regional CMRglc values. Only 1 of 65 ratios of regional-to-whole brain CMRglc differed significantly between men and women, which is consistent with chance. These results indicate that there are no differences in resting regional cerebral glucose utilization between young men and women.

  10. Enhancement of molecular sensitivity in positron emission tomography with quantum correlation of γ-ray photons

    NASA Astrophysics Data System (ADS)

    Sato, K.; Kobayashi, Y.

    2015-05-01

    Enhancement of molecular sensitivity in positron emission tomography (PET) has long been discussed with respect to imaging instrumentation and algorithms for data treatment. Here, the molecular sensitivity in PET is discussed on the basis of 2-dimensional coincident measurements of 511 keV γ ray photons resultant from two-photon annihilation. Introduction of an additional selection window based on the energy sum and difference of the coincidently measured γ ray photons, without any significant instrumental and algorithmic changes, showed an improvement in the signal-to-noise ratio (SNR) by an order of magnitude. Improvement of performance characteristics in the PET imaging system was demonstrated by an increase in the noise equivalent count rate (NECR) which takes both the SNR and the detection efficiency into consideration. A further improvement of both the SNR and the NECR is expected for the present system in real clinical and in-vivo environments, where much stronger positron sources are employed.

  11. Photoacoustic tomography using a Michelson interferometer with quadrature phase detection

    NASA Astrophysics Data System (ADS)

    Speirs, Rory W.; Bishop, Alexis I.

    2013-07-01

    We present a pressure sensor based on a Michelson interferometer, for use in photoacoustic tomography. Quadrature phase detection is employed allowing measurement at any point on the mirror surface without having to retune the interferometer, as is typically required by Fabry-Perot type detectors. This opens the door to rapid full surface detection, which is necessary for clinical applications. Theory relating acoustic pressure to detected acoustic particle displacements is used to calculate the detector sensitivity, which is validated with measurement. Proof-of-concept tomographic images of blood vessel phantoms have been taken with sub-millimeter resolution at depths of several millimeters.

  12. Evaluating Positron Emission Tomography Use in Differentiated Thyroid Cancer

    PubMed Central

    Esfandiari, Nazanene H.; Papaleontiou, Maria; Worden, Francis P.; Haymart, Megan R.

    2015-01-01

    Background: Using the Surveillance, Epidemiology, and End Results—Medicare database, a substantial increase was found in the use of positron emission tomography (PET) scans after 2004 in differentiated thyroid cancer (DTC) patients. The reason for the increased utilization of the PET scan was not clear based on available the data. Therefore, the indications for and outcomes of PET scans performed at an academic institution were evaluated. Methods: A retrospective cohort study was performed of DTC patients who underwent surgery at the University of Michigan Health System from 2006 to 2011. After identifying patients who underwent a PET scan, indications, rate of positive PET scans, and impact on management were evaluated. For positive scans, the location of disease was characterized, and presence of disease on other imaging was determined. Results: Of the 585 patients in the cohort, 111 (19%) patients had 200 PET scans performed for evaluation of DTC. Indications for PET scan included: elevated thyroglobulin and negative radioiodine scan in 52 scans (26.0%), thyroglobulin antibodies in 13 scans (6.5%), rising thyroglobulin in 18 scans (9.0%), evaluation of abnormality on other imaging in 22 scans (11.0%), evaluation of extent of disease in 33 scans (16.5%), follow-up of previous scan in 57 scans (28.5%), other indications in two scans (1.0%), and unclear indications in three scans (1.5%). The PET scan was positive in 124 studies (62.0%); positivity was identified in the thyroid bed on 25 scans, cervical or mediastinal lymph nodes on 105 scans, lung on 28 scans, bone on four scans, and other areas on 14 scans. Therapy following PET scan was surgery in 66 cases (33.0%), chemotherapy or radiation in 23 cases (11.5%), observation in 110 cases (55.0%), and palliative care in one case (0.5%). Disease was identifiable on other imaging in 66% of cases. PET scan results changed management in 59 cases (29.5%). Conclusions: In this academic medical center, the PET scan was

  13. Practical implementation of tetrahedral mesh reconstruction in emission tomography

    NASA Astrophysics Data System (ADS)

    Boutchko, R.; Sitek, A.; Gullberg, G. T.

    2013-05-01

    This paper presents a practical implementation of image reconstruction on tetrahedral meshes optimized for emission computed tomography with parallel beam geometry. Tetrahedral mesh built on a point cloud is a convenient image representation method, intrinsically three-dimensional and with a multi-level resolution property. Image intensities are defined at the mesh nodes and linearly interpolated inside each tetrahedron. For the given mesh geometry, the intensities can be computed directly from tomographic projections using iterative reconstruction algorithms with a system matrix calculated using an exact analytical formula. The mesh geometry is optimized for a specific patient using a two stage process. First, a noisy image is reconstructed on a finely-spaced uniform cloud. Then, the geometry of the representation is adaptively transformed through boundary-preserving node motion and elimination. Nodes are removed in constant intensity regions, merged along the boundaries, and moved in the direction of the mean local intensity gradient in order to provide higher node density in the boundary regions. Attenuation correction and detector geometric response are included in the system matrix. Once the mesh geometry is optimized, it is used to generate the final system matrix for ML-EM reconstruction of node intensities and for visualization of the reconstructed images. In dynamic PET or SPECT imaging, the system matrix generation procedure is performed using a quasi-static sinogram, generated by summing projection data from multiple time frames. This system matrix is then used to reconstruct the individual time frame projections. Performance of the new method is evaluated by reconstructing simulated projections of the NCAT phantom and the method is then applied to dynamic SPECT phantom and patient studies and to a dynamic microPET rat study. Tetrahedral mesh-based images are compared to the standard voxel-based reconstruction for both high and low signal-to-noise ratio

  14. Practical implementation of tetrahedral mesh reconstruction in emission tomography.

    PubMed

    Boutchko, R; Sitek, A; Gullberg, G T

    2013-05-07

    This paper presents a practical implementation of image reconstruction on tetrahedral meshes optimized for emission computed tomography with parallel beam geometry. Tetrahedral mesh built on a point cloud is a convenient image representation method, intrinsically three-dimensional and with a multi-level resolution property. Image intensities are defined at the mesh nodes and linearly interpolated inside each tetrahedron. For the given mesh geometry, the intensities can be computed directly from tomographic projections using iterative reconstruction algorithms with a system matrix calculated using an exact analytical formula. The mesh geometry is optimized for a specific patient using a two stage process. First, a noisy image is reconstructed on a finely-spaced uniform cloud. Then, the geometry of the representation is adaptively transformed through boundary-preserving node motion and elimination. Nodes are removed in constant intensity regions, merged along the boundaries, and moved in the direction of the mean local intensity gradient in order to provide higher node density in the boundary regions. Attenuation correction and detector geometric response are included in the system matrix. Once the mesh geometry is optimized, it is used to generate the final system matrix for ML-EM reconstruction of node intensities and for visualization of the reconstructed images. In dynamic PET or SPECT imaging, the system matrix generation procedure is performed using a quasi-static sinogram, generated by summing projection data from multiple time frames. This system matrix is then used to reconstruct the individual time frame projections. Performance of the new method is evaluated by reconstructing simulated projections of the NCAT phantom and the method is then applied to dynamic SPECT phantom and patient studies and to a dynamic microPET rat study. Tetrahedral mesh-based images are compared to the standard voxel-based reconstruction for both high and low signal-to-noise ratio

  15. Positron Emission Tomography Imaging Using Radiolabeled Inorganic Nanomaterials

    PubMed Central

    Sun, Xiaolian; Cai, Weibo; Chen, Xiaoyuan

    2015-01-01

    CONSPECTUS Positron emission tomography (PET) is a radionuclide imaging technology that plays an important role in preclinical and clinical research. With administration of a small amount of radiotracer, PET imaging can provide a noninvasive, highly sensitive, and quantitative readout of its organ/tissue targeting efficiency and pharmacokinetics. Various radiotracers have been designed to target specific molecular events. Compared with antibodies, proteins, peptides, and other biologically relevant molecules, nanoparticles represent a new frontier in molecular imaging probe design, enabling the attachment of different imaging modalities, targeting ligands, and therapeutic payloads in a single vector. We introduce the radiolabeled nanoparticle platforms that we and others have developed. Due to the fundamental differences in the various nanoparticles and radioisotopes, most radiolabeling methods are designed case-by-case. We focus on some general rules about selecting appropriate isotopes for given types of nanoparticles, as well as adjusting the labeling strategies according to specific applications. We classified these radiolabeling methods into four categories: (1) complexation reaction of radiometal ions with chelators via coordination chemistry; (2) direct bombardment of nanoparticles via hadronic projectiles; (3) synthesis of nanoparticles using a mixture of radioactive and nonradioactive precursors; (4) chelator-free postsynthetic radiolabeling. Method 1 is generally applicable to different nanomaterials as long as the surface chemistry is well-designed. However, the addition of chelators brings concerns of possible changes to the physicochemical properties of nanomaterials and detachment of the radiometal. Methods 2 and 3 have improved radiochemical stability. The applications are, however, limited by the possible damage to the nanocomponent caused by the proton beams (method 2) and harsh synthetic conditions (method 3). Method 4 is still in its infancy

  16. [Ventricular volumes determined by single-photon emission computed tomography].

    PubMed

    Katohno, E; Ono, K; Owada, K; Fujino, A; Watanabe, N; Sato, M; Konno, I; Yaoita, H; Tsuda, F; Kariyone, S

    1987-06-01

    To determine right (RV) and left ventricular (LV) volumes, a new technique was developed using ECG-gated single-photon emission computed tomography (SPECT). RV volumes of nine patients and LV volumes of 22 patients measured by SPECT and biplane contrast cineangiography were compared. In addition, volume and ejection fraction (EF) of the RV and LV were obtained by SPECT for 10 normal controls, 21 patients with old myocardial infarction (OMI), eight patients with hypertrophic cardiomyopathy (HCM) and 12 patients with dilated cardiomyopathy (DCM), and these results were compared. The intracardiac blood pool was labeled with Tc-99m sodium pertechnetate and 32 images were recorded through 180 degrees by a rotating gamma-camera. End-diastolic and end-systolic counts during 50 msec were recorded during 50 or 60 cardiac cycles. These counting data were reconstructed as tomographic images of vertical long-axial slices with thickness of a pixel without any attenuation correction. The numbers of voxels within the % cut-off level were summed, and the sum was multiplied by the one voxel volume. The cut-off level for ventricular delineation was determined as 45% by phantom studies. 1. The values obtained from SPECT and contrast angiography correlated well. 2. In normal controls, LV end-diastolic and end-systolic volumes were significantly less than those of the RV (p less than 0.05, p less than 0.001) and LVEF was significantly greater than the RVEF (p less than 0.001). 3. In OMI (single vessel disease), both end-diastolic and end-systolic volumes of the LV were significantly greater than those of normals (p less than 0.01, p less than 0.001) and LVEF was significantly less. In HCM end-systolic volumes of the RV were significantly less (p less than 0.05) than those of the normals. 4. LV volume was greater and LVEF was extremely low both in DCM and in OMI (multivessel disease) compared to that of the normals. In DCM, RV end-systolic volumes was greater and RVEF was lower than

  17. Positron emission tomography imaging using radiolabeled inorganic nanomaterials.

    PubMed

    Sun, Xiaolian; Cai, Weibo; Chen, Xiaoyuan

    2015-02-17

    CONSPECTUS: Positron emission tomography (PET) is a radionuclide imaging technology that plays an important role in preclinical and clinical research. With administration of a small amount of radiotracer, PET imaging can provide a noninvasive, highly sensitive, and quantitative readout of its organ/tissue targeting efficiency and pharmacokinetics. Various radiotracers have been designed to target specific molecular events. Compared with antibodies, proteins, peptides, and other biologically relevant molecules, nanoparticles represent a new frontier in molecular imaging probe design, enabling the attachment of different imaging modalities, targeting ligands, and therapeutic payloads in a single vector. We introduce the radiolabeled nanoparticle platforms that we and others have developed. Due to the fundamental differences in the various nanoparticles and radioisotopes, most radiolabeling methods are designed case-by-case. We focus on some general rules about selecting appropriate isotopes for given types of nanoparticles, as well as adjusting the labeling strategies according to specific applications. We classified these radiolabeling methods into four categories: (1) complexation reaction of radiometal ions with chelators via coordination chemistry; (2) direct bombardment of nanoparticles via hadronic projectiles; (3) synthesis of nanoparticles using a mixture of radioactive and nonradioactive precursors; (4) chelator-free postsynthetic radiolabeling. Method 1 is generally applicable to different nanomaterials as long as the surface chemistry is well-designed. However, the addition of chelators brings concerns of possible changes to the physicochemical properties of nanomaterials and detachment of the radiometal. Methods 2 and 3 have improved radiochemical stability. The applications are, however, limited by the possible damage to the nanocomponent caused by the proton beams (method 2) and harsh synthetic conditions (method 3). Method 4 is still in its infancy

  18. Improved diagnostic performance of exercise thallium-201 single photon emission computed tomography over planar imaging in the diagnosis of coronary artery disease: a receiver operating characteristic analysis

    SciTech Connect

    Fintel, D.J.; Links, J.M.; Brinker, J.A.; Frank, T.L.; Parker, M.; Becker, L.C.

    1989-03-01

    Qualitative interpretation of tomographic and planar scintigrams, a five point rating scale and receiver operating characteristic analysis were utilized to compare single photon emission computed tomography and conventional planar imaging of myocardial thallium-201 uptake in the accuracy of the diagnosis of coronary artery disease and individual vessel involvement. One hundred twelve patients undergoing cardiac catheterization and 23 normal volunteers performed symptom-limited treadmill exercise, followed by stress and redistribution imaging by both tomographic and planar techniques, with the order determined randomly. Paired receiver operating characteristic curves revealed that single photon emission computed tomography was more accurate than planar imaging over the entire range of decision thresholds for the overall detection and exclusion of coronary artery disease and involvement of the left anterior descending and left circumflex coronary arteries. Tomography offered relatively greater advantages in male patients and in patients with milder forms of coronary artery disease, who had no prior myocardial infarction, only single vessel involvement or no lesion greater than or equal to 50 to 69%. Tomography did not appear to provide improved diagnosis in women or in detection of disease in the right coronary artery. Although overall detection of coronary artery disease was not improved in patients with prior myocardial infarction, tomography provided improved identification of normal and abnormal vascular regions. These results indicate that single photon emission computed tomography provides improved diagnostic performance compared with planar imaging in many clinical subgroups.

  19. RF Tomography for Tunnel Detection: Principles and Inversion Schemes

    NASA Astrophysics Data System (ADS)

    Lo Monte, L.; Erricolo, D.; Inan, U. S.; Wicks, M. C.

    2008-12-01

    We propose a novel way to detect underground tunnels based on classical seismic tomography, Ground Penetrating Radar (GPR), inverse scattering principles, and the deployment of distributed sensors, which we call "Distributed RF Tomography". Tunnel detection has been a critical problem that cannot be considered fully solved. Presently, tunnel detection is performed by methods that include seismic sensors, electrical impedance, microgravity, boreholes, and GPR. All of these methods have drawbacks that make them not applicable for use in unfriendly environments, such as battlefields. Specifically, they do not cover wide surface areas, they are generally shallow, they are limited to vertical prospecting, and require the user to be in situ, which may jeopardize one's safety. Additional application of the proposed distributed RF tomography include monitoring sensitive areas, (e.g. banks, power plants, military bases, prisons, national borders) and civil applications (e.g. environmental engineering, mine safety, search and rescue, speleology, archaeology and geophysics). The novelty of a Distributed RF tomography system consists of the following. 1) Sensors are scattered randomly above the ground, thus saving time and money compared to the use of boreholes. 2) The use of lower operating frequency (around HF), which allows for deeper penetration. 3) The use of CW diffraction tomography, which increases the resolution to sub-wavelength values, independently from the sensor displacement, and increases the SNR. 4) Use of linear inversion schemes that are suited for tunnel detection. 5) The use of modulation schemes and signal processing algorithms to mitigate interferences and noise. This presentation will cover: 1. Current physical limits of existing techniques for tunnel detection. 2. Concept of Distributed RF Tomography. 3. Inversion theories and strategies a. Proper forward model for voids buried into an homogeneous medium b. Extended matched filtering inversion c. Near

  20. A case of skeletal tuberculosis and psoas abscess: disease activity evaluated using 18 F-fluorodeoxyglucose positron emission tomography-computed tomography

    PubMed Central

    2013-01-01

    Background Psoas abscess complicating tuberculous spondylitis is a rare morbidity in extrapulmonary tuberculosis. There are no established guidelines for evaluating the clinical response of psoas abscess. Although several studies have shown that positron emission tomography-computed tomography with 18 F-fluorodeoxyglucose can play a potential role in diagnosing multifocal tuberculosis and monitoring the clinical response of pulmonary tuberculosis, to our knowledge, this is the first report demonstrating that positron emission tomography-computed tomography is useful for evaluating local inflammation and disease activity of a tuberculous psoas abscess. Case presentation We report a case of multifocal bone and lymph node tuberculosis with concomitant lumbar psoas abscess in a 77-year-old man, along with a literature review. An initial positron emission tomography-computed tomography scan showed intense 18 F-fluorodeoxyglucose accumulation in the sternum, ribs, vertebrae, and lymph nodes. The patient was successfully treated with antitubercular agents and computed tomography-guided drainage therapy. A follow-up positron emission tomography-computed tomography after abscess drainage and 9 months of antitubercular drug treatment revealed that the majority of lesions improved; however, protracted inflammation surrounding the psoas abscess was still observed. These results indicate that disease activity of psoas abscess can remain, even after successful drainage and antitubercular medication regime of appropriate duration. Conclusion We have successfully followed up the extent of skeletal tuberculosis complicated with psoas abscess by positron emission tomography-computed tomography. In this patient, positron emission tomography-computed tomography is useful for evaluating the disease activity of tuberculous psoas abscess and for assessing the appropriate duration of antitubercular drug therapy in psoas abscess. PMID:24225333

  1. Design of a portable optical emission tomography system for microwave induced compact plasma for visible to near-infrared emission lines

    NASA Astrophysics Data System (ADS)

    Rathore, Kavita; Munshi, Prabhat; Bhattacharjee, Sudeep

    2016-03-01

    A new non-invasive diagnostic system is developed for Microwave Induced Plasma (MIP) to reconstruct tomographic images of a 2D emission profile. A compact MIP system has wide application in industry as well as research application such as thrusters for space propulsion, high current ion beams, and creation of negative ions for heating of fusion plasma. Emission profile depends on two crucial parameters, namely, the electron temperature and density (over the entire spatial extent) of the plasma system. Emission tomography provides basic understanding of plasmas and it is very useful to monitor internal structure of plasma phenomena without disturbing its actual processes. This paper presents development of a compact, modular, and versatile Optical Emission Tomography (OET) tool for a cylindrical, magnetically confined MIP system. It has eight slit-hole cameras and each consisting of a complementary metal-oxide-semiconductor linear image sensor for light detection. The optical noise is reduced by using aspheric lens and interference band-pass filters in each camera. The entire cylindrical plasma can be scanned with automated sliding ring mechanism arranged in fan-beam data collection geometry. The design of the camera includes a unique possibility to incorporate different filters to get the particular wavelength light from the plasma. This OET system includes selected band-pass filters for particular argon emission 750 nm, 772 nm, and 811 nm lines and hydrogen emission Hα (656 nm) and Hβ (486 nm) lines. Convolution back projection algorithm is used to obtain the tomographic images of plasma emission line. The paper mainly focuses on (a) design of OET system in detail and (b) study of emission profile for 750 nm argon emission lines to validate the system design.

  2. Design of a portable optical emission tomography system for microwave induced compact plasma for visible to near-infrared emission lines.

    PubMed

    Rathore, Kavita; Munshi, Prabhat; Bhattacharjee, Sudeep

    2016-03-01

    A new non-invasive diagnostic system is developed for Microwave Induced Plasma (MIP) to reconstruct tomographic images of a 2D emission profile. A compact MIP system has wide application in industry as well as research application such as thrusters for space propulsion, high current ion beams, and creation of negative ions for heating of fusion plasma. Emission profile depends on two crucial parameters, namely, the electron temperature and density (over the entire spatial extent) of the plasma system. Emission tomography provides basic understanding of plasmas and it is very useful to monitor internal structure of plasma phenomena without disturbing its actual processes. This paper presents development of a compact, modular, and versatile Optical Emission Tomography (OET) tool for a cylindrical, magnetically confined MIP system. It has eight slit-hole cameras and each consisting of a complementary metal-oxide-semiconductor linear image sensor for light detection. The optical noise is reduced by using aspheric lens and interference band-pass filters in each camera. The entire cylindrical plasma can be scanned with automated sliding ring mechanism arranged in fan-beam data collection geometry. The design of the camera includes a unique possibility to incorporate different filters to get the particular wavelength light from the plasma. This OET system includes selected band-pass filters for particular argon emission 750 nm, 772 nm, and 811 nm lines and hydrogen emission H(α) (656 nm) and H(β) (486 nm) lines. Convolution back projection algorithm is used to obtain the tomographic images of plasma emission line. The paper mainly focuses on (a) design of OET system in detail and (b) study of emission profile for 750 nm argon emission lines to validate the system design.

  3. Design of a portable optical emission tomography system for microwave induced compact plasma for visible to near-infrared emission lines

    SciTech Connect

    Rathore, Kavita E-mail: pmunshi@iitk.ac.in Munshi, Prabhat E-mail: pmunshi@iitk.ac.in; Bhattacharjee, Sudeep E-mail: pmunshi@iitk.ac.in

    2016-03-15

    A new non-invasive diagnostic system is developed for Microwave Induced Plasma (MIP) to reconstruct tomographic images of a 2D emission profile. A compact MIP system has wide application in industry as well as research application such as thrusters for space propulsion, high current ion beams, and creation of negative ions for heating of fusion plasma. Emission profile depends on two crucial parameters, namely, the electron temperature and density (over the entire spatial extent) of the plasma system. Emission tomography provides basic understanding of plasmas and it is very useful to monitor internal structure of plasma phenomena without disturbing its actual processes. This paper presents development of a compact, modular, and versatile Optical Emission Tomography (OET) tool for a cylindrical, magnetically confined MIP system. It has eight slit-hole cameras and each consisting of a complementary metal–oxide–semiconductor linear image sensor for light detection. The optical noise is reduced by using aspheric lens and interference band-pass filters in each camera. The entire cylindrical plasma can be scanned with automated sliding ring mechanism arranged in fan-beam data collection geometry. The design of the camera includes a unique possibility to incorporate different filters to get the particular wavelength light from the plasma. This OET system includes selected band-pass filters for particular argon emission 750 nm, 772 nm, and 811 nm lines and hydrogen emission H{sub α} (656 nm) and H{sub β} (486 nm) lines. Convolution back projection algorithm is used to obtain the tomographic images of plasma emission line. The paper mainly focuses on (a) design of OET system in detail and (b) study of emission profile for 750 nm argon emission lines to validate the system design.

  4. [Detection and characterization of pulmonary nodules using multislice computed tomography].

    PubMed

    Bastarrika, G; Cano, D; Hernández, C; Alonso-Burgos, A; González, I; Villanueva, A; Vivas, I; Zulueta, J

    2007-01-01

    Pulmonary nodules are a common finding in routine chest studies. Although there are no pathognomic clinical or radiological signs that enable the exact nature of a pulmonary nodule to be determined, the clinical context and the appropriate characterization of the pulmonary nodule make it possible to reach the correct diagnosis in most cases. This article discusses the most important aspects involved in the use of multislice computed tomography in the noninvasive detection and characterization of pulmonary nodules.

  5. Early Detection of Breast Cancer by Fluorescence Molecular Tomography

    DTIC Science & Technology

    2007-07-01

    development of appropriate fluorescence imaging methods for highly reliable and quantitative fluorescence imaging ii ) the establishment and imaging of...Tomography (FMT) is a relatively new optical tomographic imaging approach that capitalizes on the strengths of molecular imaging. It bases detection...The large boxes on Fig.5 b,c indicate the detector FOV. Fig.5 b,c depict FMT ( tomo - synthesis) images in color, obtained with an empirical

  6. Flourodeoxyglucose positron emission tomography scan may be helpful in the case of ductal variant prostate cancer when prostate specific membrane antigen ligand positron emission tomography scan is negative.

    PubMed

    McEwan, Louise M; Wong, David; Yaxley, John

    2017-03-28

    Gallium-68 prostate specific membrane antigen ligand (Ga-68 PSMA) positron emission tomography/computed tomography (PET/CT) scanning is emerging as a useful imaging modality for the staging of suspected and known recurrent or metastatic prostate cancer and in staging of newly diagnosed higher grade prostate cancer. However, we have observed at our institution that in some cases of the more aggressive ductal variant, Ga-68 PSMA uptake has sometimes been poor compared with prominent 18-flourodeoxyglucose (F-18 FDG) avidity seen in F-18 FDG PET/CT, which would suggest that FDG PET/CT scans are important in staging of ductal pattern prostate cancer.

  7. Computed tomography and (18)F-fluorodeoxyglucose positron emission tomography/computed tomography findings in adrenal candidiasis and histoplasmosis: two cases.

    PubMed

    Altinmakas, Emre; Guo, Ming; Kundu, Uma R; Habra, Mouhammed Amir; Ng, Chaan

    2015-01-01

    We report the contrast-enhanced computed tomography (CT) and (18)F-fluorodeoxyglucose positron emission tomography findings in adrenal histoplasmosis and candidiasis. Both demonstrated bilateral hypermetabolic heterogeneous adrenal masses with limited wash-out on delayed CT. Adrenal candidiasis has not been previously reported, nor have the CT wash-out findings in either infection. The adrenal imaging findings are indistinguishable from malignancy, which is more common; but in this setting, physicians should be alert to the differential diagnosis of fungal infections, since it can be equally deadly.

  8. Sensitivity estimation in time-of-flight list-mode positron emission tomography

    SciTech Connect

    Herraiz, J. L.; Sitek, A.

    2015-11-15

    Purpose: An accurate quantification of the images in positron emission tomography (PET) requires knowing the actual sensitivity at each voxel, which represents the probability that a positron emitted in that voxel is finally detected as a coincidence of two gamma rays in a pair of detectors in the PET scanner. This sensitivity depends on the characteristics of the acquisition, as it is affected by the attenuation of the annihilation gamma rays in the body, and possible variations of the sensitivity of the scanner detectors. In this work, the authors propose a new approach to handle time-of-flight (TOF) list-mode PET data, which allows performing either or both, a self-attenuation correction, and self-normalization correction based on emission data only. Methods: The authors derive the theory using a fully Bayesian statistical model of complete data. The authors perform an initial evaluation of algorithms derived from that theory and proposed in this work using numerical 2D list-mode simulations with different TOF resolutions and total number of detected coincidences. Effects of randoms and scatter are not simulated. Results: The authors found that proposed algorithms successfully correct for unknown attenuation and scanner normalization for simulated 2D list-mode TOF-PET data. Conclusions: A new method is presented that can be used for corrections for attenuation and normalization (sensitivity) using TOF list-mode data.

  9. Sensitivity estimation in time-of-flight list-mode positron emission tomography

    PubMed Central

    Herraiz, J. L.; Sitek, A.

    2015-01-01

    Purpose: An accurate quantification of the images in positron emission tomography (PET) requires knowing the actual sensitivity at each voxel, which represents the probability that a positron emitted in that voxel is finally detected as a coincidence of two gamma rays in a pair of detectors in the PET scanner. This sensitivity depends on the characteristics of the acquisition, as it is affected by the attenuation of the annihilation gamma rays in the body, and possible variations of the sensitivity of the scanner detectors. In this work, the authors propose a new approach to handle time-of-flight (TOF) list-mode PET data, which allows performing either or both, a self-attenuation correction, and self-normalization correction based on emission data only. Methods: The authors derive the theory using a fully Bayesian statistical model of complete data. The authors perform an initial evaluation of algorithms derived from that theory and proposed in this work using numerical 2D list-mode simulations with different TOF resolutions and total number of detected coincidences. Effects of randoms and scatter are not simulated. Results: The authors found that proposed algorithms successfully correct for unknown attenuation and scanner normalization for simulated 2D list-mode TOF-PET data. Conclusions: A new method is presented that can be used for corrections for attenuation and normalization (sensitivity) using TOF list-mode data. PMID:26520759

  10. Distinguishing tumor recurrence from irradiation sequelae with positron emission tomography in patients treated for larynx cancer

    SciTech Connect

    Greven, K.M.; Williams, D.W. III; Keyes, J.W. Jr.; McGuirt, W.F.; Harkness, B.A.; Watson, N.E. Jr.; Raben, M.; Frazier, L.C.; Geisinger, K.R.; Capellari, J.O.

    1994-07-01

    Distinguishing persistent or recurrent tumor from postradiation edema, or soft tissue/cartilage necrosis in patients treated for carcinoma of the larynx can be difficult. Because recurrent tumor is often submucosal, multiple deep biopsies may be necessary before a diagnosis can be established. Positron emission tomography with 18F-2-fluro-2-deoxglucose (FDG) was studied for its ability to aid in this problem. Positron emission tomography (18FDG) scans were performed on 11 patients who were suspected of having persistent or recurrent tumor after radiation treatment for carcinoma of the larynx. Patients underwent thorough history and physical examinations, scans with computerized tomography, and pathologic evaluation when indicated. Standard uptake values were used to quantitate the FDG uptake in the larynx. The time between completion of radiation treatment and positron emission tomography examination ranged from 2 to 26 months with a median of 6 months. Ten patients underwent computed tomography (CT) of the larynx, which revealed edema of the larynx (six patients), glottic mass (four patients), and cervical nodes (one patient). Positron emission tomography scans revealed increased FDG uptake in the larynx in five patients and laryngectomy confirmed the presence of carcinoma in these patients. Five patients had positron emission tomography results consistent with normal tissue changes in the larynx, and one patient had increased FDG uptake in neck nodes. This patient underwent laryngectomy, and no cancer was found in the primary site, but nodes were pathologically positive. One patient had slightly elevated FDG uptake and negative biopsy results. The remaining patients have been followed for 11 to 14 months since their positron emission studies and their examinations have remained stable. In patients without tumor, average standard uptake values of the larynx ranged from 2.4 to 4.7, and in patients with tumor, the range was 4.9 to 10.7. 18 refs., 3 figs., 1 tab.

  11. Fluorodeoxyglucose positron emission tomography in primary thyroid lymphoma with coexisting lymphocytic thyroiditis.

    PubMed

    Arabi, Mohammad; Dvorak, Ryan; Smith, Lauren B; Kujawski, Lisa; Gross, Milton D

    2011-10-01

    Primary thyroid lymphoma is an uncommon neoplasm frequently associated with lymphocytic thyroiditis (LT). Once the pathologic diagnosis of primary thyroid lymphoma is established, imaging plays an important role in tumor staging and evaluating treatment response. The present case discusses the role of fluorodeoxyglucose positron emission tomography (18F-FDG PET)/computed tomography (CT) in this clinical setting along with the potential diagnostic challenges. A 44-year-old man with a history of LT and hypothyroidism presented with an enlarging goiter. Initial imaging evaluation showed markedly enlarged gland with bilateral cervical and mediastinal adenopathy. Histopathologic evaluation confirmed the diagnosis of primary thyroid lymphoma on a background of LT. An 18F-FDG PET/CT revealed increased uptake in the gland and lymph nodes. Follow-up 18F-FDG PET/CT after chemotherapy showed interval decrease in FDG uptake in the thyroid gland associated with interval decrease in the size and metabolic activity of the cervical and superior mediastinal lymph nodes. The frequent association of LT with primary thyroid lymphoma and the overlap of their clinical and pathologic findings pose a significant diagnostic challenge. While other imaging techniques are helpful in evaluating anatomic local and regional extent of primary thyroid lymphoma, 18F-FDG PET/CT can be of an added value in evaluating its metabolic activity and detecting regional and distant disease as well as in assessing response to treatment.

  12. TOPICAL REVIEW: Biological imaging in radiation therapy: role of positron emission tomography

    NASA Astrophysics Data System (ADS)

    Nestle, Ursula; Weber, Wolfgang; Hentschel, Michael; Grosu, Anca-Ligia

    2009-01-01

    In radiation therapy (RT), staging, treatment planning, monitoring and evaluation of response are traditionally based on computed tomography (CT) and magnetic resonance imaging (MRI). These radiological investigations have the significant advantage to show the anatomy with a high resolution, being also called anatomical imaging. In recent years, so called biological imaging methods which visualize metabolic pathways have been developed. These methods offer complementary imaging of various aspects of tumour biology. To date, the most prominent biological imaging system in use is positron emission tomography (PET), whose diagnostic properties have clinically been evaluated for years. The aim of this review is to discuss the valences and implications of PET in RT. We will focus our evaluation on the following topics: the role of biological imaging for tumour tissue detection/delineation of the gross tumour volume (GTV) and for the visualization of heterogeneous tumour biology. We will discuss the role of fluorodeoxyglucose-PET in lung and head and neck cancer and the impact of amino acids (AA)-PET in target volume delineation of brain gliomas. Furthermore, we summarize the data of the literature about tumour hypoxia and proliferation visualized by PET. We conclude that, regarding treatment planning in radiotherapy, PET offers advantages in terms of tumour delineation and the description of biological processes. However, to define the real impact of biological imaging on clinical outcome after radiotherapy, further experimental, clinical and cost/benefit analyses are required.

  13. Identifying active vascular microcalcification by 18F-sodium fluoride positron emission tomography

    PubMed Central

    Irkle, Agnese; Vesey, Alex T.; Lewis, David Y.; Skepper, Jeremy N.; Bird, Joseph L. E.; Dweck, Marc R.; Joshi, Francis R.; Gallagher, Ferdia A.; Warburton, Elizabeth A.; Bennett, Martin R.; Brindle, Kevin M.; Newby, David E.; Rudd, James H.; Davenport, Anthony P.

    2015-01-01

    Vascular calcification is a complex biological process that is a hallmark of atherosclerosis. While macrocalcification confers plaque stability, microcalcification is a key feature of high-risk atheroma and is associated with increased morbidity and mortality. Positron emission tomography and X-ray computed tomography (PET/CT) imaging of atherosclerosis using 18F-sodium fluoride (18F-NaF) has the potential to identify pathologically high-risk nascent microcalcification. However, the precise molecular mechanism of 18F-NaF vascular uptake is still unknown. Here we use electron microscopy, autoradiography, histology and preclinical and clinical PET/CT to analyse 18F-NaF binding. We show that 18F-NaF adsorbs to calcified deposits within plaque with high affinity and is selective and specific. 18F-NaF PET/CT imaging can distinguish between areas of macro- and microcalcification. This is the only currently available clinical imaging platform that can non-invasively detect microcalcification in active unstable atherosclerosis. The use of 18F-NaF may foster new approaches to developing treatments for vascular calcification. PMID:26151378

  14. Digital balanced detection for fast optical computerized tomography

    NASA Astrophysics Data System (ADS)

    Hafiz, Rehan; Ozanyan, Krikor B.

    2006-10-01

    Analogue Balanced Photo-detection has found extensive usage in high- sensitivity small signal applications e.g. coherent heterodyne detection. It is particularly effective for laser intensity noise removal. Nevertheless, the high cost of the commercially available analogue systems makes them unsuitable for multi-channel applications, such as fast tomography. In this paper a flexible, scalable, inexpensive and compact solution for multi channel digital balanced detection is presented. The proposed system has two components: an analogue front-end, comprising a differential photodiode amplifier for minimizing the external interference noise, and a digital balanced noise remover. The latter component initially calculates a balancing factor (BF) from the average power ratio of the signal and reference photocurrents, measured with the object removed from the signal path. Three digital balancing algorithms (DBAx) are considered for subsequent processing. In DBA1, BF is directly used in real-time ratiometric calculations. In DBA2, the BF is adjusted in real time by monitoring the window-averaged power of the received photocurrents. In DBA3, first the baseline is removed using differentiation and then ratiometric detection is performed. Using the digital alternative only one measurement of the reference beam is necessary for single-source, multi-channel detection systems. The data from multiple channels are processed in parallel by pipelined hardware, configured as a state machine. The proposed system leads to a fast optical computerized tomography system using digital balanced detection.

  15. Breath-hold single-photon emission tomography and computed tomography for predicting residual pulmonary function in patients with lung cancer.

    PubMed

    Sudoh, Manabu; Ueda, Kazuhiro; Kaneda, Yoshikazu; Mitsutaka, Jinbo; Li, Tao-Sheng; Suga, Kazuyoshi; Kawakami, Yasuhiko; Hamano, Kimikazu

    2006-05-01

    We sought to evaluate the utility of integrated breath-hold single-photon emission tomography and computed tomography imaging compared with that of simple calculation with the lung segment-counting technique for predicting residual pulmonary function in patients undergoing surgical intervention for lung cancer. A prospective series of 22 patients undergoing anatomic lung resection for cancer were enrolled in this study. Postoperative residual forced expiratory volume in 1 second was predicted by measuring the radioactivity counts of the affected lobes or segments to be resected within the entire lungs by placement of regions of interest on single-photon emission tomography and computed tomography images. Residual forced expiratory volume in 1 second was also estimated by using the segment-counting technique. Both predicted values agreed well with postoperative forced expiratory volume in 1 second. Although the residual forced expiratory volume in 1 second predicted by means of single-photon emission tomography and computed tomography correlated well with that predicted by using segment counting, the values were significantly underestimated by the segment-counting technique in 4 outliers with severe emphysema. There were 2 patients with borderline pulmonary functional reserve whose residual forced expiratory volume in 1 second values were predicted more accurately by means of single-photon emission tomography and computed tomography than by using segment counting. Integrated breath-hold single-photon emission tomography and computed tomography images allow the accurate prediction of postoperative pulmonary function but without statistical superiority over the simple segment-counting technique. Further study of the usefulness of single-photon emission tomography and computed tomography in patients with severe emphysema and borderline lung function should prove valuable because the segment-counting technique underestimates pulmonary functional reserve in these

  16. The role of positron emission tomography with computed tomography in the follow-up of asymptomatic cutaneous malignant melanoma patients with a high risk of disease recurrence.

    PubMed

    Abbott, Rachel Angharad; Acland, Katharine M; Harries, Mark; O'Doherty, Michael

    2011-10-01

    The aim of this study was to evaluate the role of [F] fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) as a surveillance tool in asymptomatic patients with primary cutaneous melanoma with the American Joint Committee on Cancer stage 3 disease. Thirty-four patients with primary cutaneous malignant melanoma with American Joint Committee on Cancer stage 3 disease, who underwent at least one annual surveillance PET/CT scan, were retrospectively identified from our PET Centre Database in May 2008 and their characteristics, PET/CT results and disease course were reviewed. In 20 patients with microscopic stage 3 disease at diagnosis, annual surveillance PET/CT detected two of three recurrences and detected one incidental breast carcinoma. In 14 patients with macroscopic stage 3 disease at, or subsequent to, their initial diagnosis, annual PET/CT detected four of four recurrences, detected metastases in one patient who remains asymptomatic and detected one incidental thyroid carcinoma. PET/CT seems to be a useful surveillance tool in patients with macroscopic stage 3 disease, although the numbers in this study are small. However, the role of PET/CT in patients initially presenting with microscopic stage 3 disease requires further confirmation.

  17. Diagnostic advantage of stress computed tomography myocardial perfusion over single-photon emission computed tomography for the assessment of myocardial ischemia.

    PubMed

    Ueki, Yasushi; Izawa, Atsushi; Kashiwagi, Daisuke; Nishiyama, Shigeki; Aso, Shinichi; Suzuki, Chihiro; Sakurai, Shumpei; Oguchi, Kazuhiro; Yazaki, Yoshikazu; Ikeda, Uichi; Kuwahara, Koichiro

    2017-08-01

    This study compared adenosine stress computed tomography myocardial perfusion (CTP) with single-photon emission computed tomography (SPECT) in the diagnosis of functionally significant coronary artery stenosis using fractional flow reserve (FFR) as reference standard. We included a total of 93 coronary arteries from 31 patients in whom at least one vessel with ≥50% stenosis was detected with computed tomography coronary angiography. All patients underwent both SPECT and adenosine stress CTP, followed by invasive coronary angiography (ICA) and FFR. Diagnostic accuracy between CTP and SPECT was compared according to positive findings of either ≥99% stenosis on ICA or FFR ≤0.8. Among 78 vessels eligible for the quantitative analyses, significant coronary artery disease (CAD) was diagnosed in 22 vessels of 19 patients. Comparison of CTP vs. SPECT for sensitivity, specificity, positive predictive value (PPV), negative predictive value, and accuracy in detecting significant CAD were 59% vs. 18%, 96% vs. 93%, 87% vs. 50%, 86% vs. 74%, and 86% vs. 72%, respectively. CTP demonstrated a significant diagnostic advantage over SPECT in the identification of significant CAD, especially in terms of sensitivity and PPV. Adenosine stress CTP is useful for the noninvasive diagnosis of functionally significant CAD. Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  18. Differential diagnostic value of single-photon emission computed tomography/spiral computed tomography with Tc-99m-methylene diphosphonate in patients with spinal lesions.

    PubMed

    Zhang, Yiqiu; Shi, Hongcheng; Gu, Yushen; Xiu, Yan; Li, Beilei; Zhu, Weimin; Chen, Shuguang; Yu, Haojun

    2011-12-01

    The objective of this study was to compare the diagnostic value obtained using single-photon emission computed tomography (SPECT)/spiral computed tomography (CT) with Tc-99m methylene-diphosphonate with that obtained using SPECT alone in patients with spinal lesions. This was a retrospective study of 56 patients who underwent planar whole-body scintigraphy because of bone pain or osseous lesions that had been detected by other imaging techniques, or for the investigation of bone metastasis in patients with extraskeletal malignancies. Only patients who had hot spots detected in their spine and who had undergone single-photon emission computed tomography/computed tomography (SPECT/CT) imaging were included. One lesion from each patient was resected or biopsied for pathological diagnosis, and lesions for which a pathological diagnosis could be made were included in this study. Single-photon emission computed tomography (SPECT) and SPECT/CT images were independently interpreted by two experienced nuclear medicine physicians who had not been involved in the selection of data for the study. The physicians were aware of patients' sex, age, history of histologically confirmed extraskeletal malignancy, and whole-body scintigraphy results, but were unaware of the results of other investigations, such as X-ray, MRI, and laboratory tests. SPECT images were analyzed first, followed by SPECT/CT images. Each lesion was graded on a 4-point diagnostic scale (1, benign; 2, likely benign; 3, likely malignant; 4, malignant), and the inter-reviewer agreement and the agreement of the SPECT and SPECT/CT diagnoses with the pathology results were evaluated by κ scores. The pathology results revealed 39 malignant bone tumors and 17 benign lesions. In the malignant cases, 20 were bone metastases and 19 were malignant tumors of another histological type. The reviewers rated 67.9% of lesions as equivocal (grade 2-3) by SPECT, but only 19.6% as equivocal by SPECT/CT. The κ scores for inter

  19. Balanced detection for spectral domain optical coherence tomography.

    PubMed

    Kuo, Wen-Chuan; Lai, Chih-Ming; Huang, Yi-Shiang; Chang, Cheng-Yi; Kuo, Yue-Ming

    2013-08-12

    The use and advantages of applying balanced-detection (BD) operation method to high speed spectral domain optical coherence tomography (SDOCT) are presented in this study, which we believe is the first such demonstration. Compared to conventional SDOCT, BD-SDOCT provides two unique advantages. First, the method can suppress background noise and autocorrelation artifacts in biological tissues. Second, it is a power-efficient method which is particularly helpful for high speed SDOCT to eliminate random intensity noise and to achieve shot noise limited detection. This performance allows in vivo three-dimensional tissue visualization with high imaging quality and high speed.

  20. Positron emission tomography image on evaluating intraperitoneal dissemination of malignant gastrointestinal stromal tumor.

    PubMed

    Kobayashi, Yoshinao; Nakao, Makoto; Konishi, Masayshi; Urawa, Naohito; Iwasa, Motoh; Kaito, Masahiko; Adachi, Yukihiko

    2008-01-01

    Herein is a report of a patient with gastrointestinal stromal tumor (GIST) possibly arising from greater omentum accompanying diffuse peritoneal disseminatation. Positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) revealed that 18F-FDG uptake was widely spreading in the abdomen. In this case, the PET image was more useful than computed tomography (CT) for understanding tumor distribution rather. PET provides important information on tumor distribution and has an impact on evaluating clinical stage in GIST patients.

  1. On the detection of lunar volatile emissions

    NASA Technical Reports Server (NTRS)

    Srnka, L. J.

    1979-01-01

    This letter shows that the Apollo lunar-surface Suprathermal Ion Detection Experiment (SIDE) instruments lack the sensitivity to detect even large emissions of radiogenic gases from the moon if the venting of these gases occurs primarily at a few-well-defined sites of lunar transient phenomena (LTPs). It is suggested that specific flight instruments for the proposed ESA Polar Orbiting Lunar Observatory (POLO) mission, which could detect active venting, would help determine the energy source for LTPs and would increase knowledge of lunar geophysics. A critical-velocity model for the LTP energy source is briefly discussed.

  2. Molecular Imaging of Transporters with Positron Emission Tomography

    NASA Astrophysics Data System (ADS)

    Antoni, Gunnar; Sörensen, Jens; Hall, Håkan

    Positron emission tomography (PET) visualization of brain components in vivo is a rapidly growing field. Molecular imaging with PET is also increasingly used in drug development, especially for the determination of drug receptor interaction for CNS-active drugs. This gives the opportunity to relate clinical efficacy to per cent receptor occupancy of a drug on a certain targeted receptor and to relate drug pharmacokinetics in plasma to interaction with target protein. In the present review we will focus on the study of transporters, such as the monoamine transporters, the P-glycoprotein (Pgp) transporter, the vesicular monoamine transporter type 2, and the glucose transporter using PET radioligands. Neurotransmitter transporters are presynaptically located and in vivo imaging using PET can therefore be used for the determination of the density of afferent neurons. Several promising PET ligands for the noradrenaline transporter (NET) have been labeled and evaluated in vivo including in man, but a really useful PET ligand for NET still remains to be identified. The most promising tracer to date is (S,S)-[18F]FMeNER-D2. The in vivo visualization of the dopamine transporter (DAT) may give clues in the evaluation of conditions related to dopamine, such as Parkinson's disease and drug abuse. The first PET radioligands based on cocaine were not selective, but more recently several selective tracers such as [11C]PE2I have been characterized and shown to be suitable as PET radioligands. Although there are a large number of serotonin transporter inhibitors used today as SSRIs, it was not until very recently, when [11C]McN5652 was synthesized, that this transporter was studied using PET. New candidates as PET radioligands for the SERT have subsequently been developed and [11C]DASB and [11C]MADAM and their analogues are today the most promising ligands. The existing radioligands for Pgp transporters seem to be suitable tools for the study of both peripheral and central drug

  3. Early postischemic hyperperfusion: pathophysiologic insights from positron emission tomography.

    PubMed

    Marchal, G; Young, A R; Baron, J C

    1999-05-01

    Early postischemic hyperperfusion (EPIH) has long been documented in animal stroke models and is the hallmark of efficient recanalization of the occluded artery with subsequent reperfusion of the tissue (although occasionally it may be seen in areas bordering the hypoperfused area during arterial occlusion). In experimental stroke, early reperfusion has been reported to both prevent infarct growth and aggravate edema formation and hemorrhage, depending on the severity and duration of prior ischemia and the efficiency of reperfusion, whereas neuronal damage with or without enlarged infarction also may result from reperfusion (so-called "reperfusion injury"). In humans, focal hyperperfusion in the subacute stage (i.e., more than 48 hours after onset) has been associated with tissue necrosis in most instances, but regarding the acute stage, its occurrence, its relations with tissue metabolism and viability, and its clinical prognostic value were poorly understood before the advent of positron emission tomography (PET), in part because of methodologic issues. By measuring both CBF and metabolism, PET is an ideal imaging modality to study the pathophysiologic mechanism of EPIH. Although only a few PET studies have been performed in the acute stage that have systematically assessed tissue and clinical outcome in relation to EPIH, they have provided important insights. In one study, about one third of the patients with first-ever middle cerebral artery (MCA) territory stroke studied within 5 to 18 hours after symptom onset exhibited EPIH. In most cases, EPIH affected large parts of the cortical MCA territory in a patchy fashion, together with abnormal vasodilation (increased cerebral blood volume), "luxury perfusion" (decreased oxygen extraction fraction), and mildly increased CMRO2, which was interpreted as postischemic rebound of cellular metabolism in structurally preserved tissue. In that study, the spontaneous outcome of the tissue exhibiting EPIH was good, with late

  4. 11C-5-hydroxytryptophan positron emission tomography after radiofrequency ablation of neuroendocrine tumor liver metastases.

    PubMed

    Norlén, Olov; Nilsson, Anders; Krause, Johan; Stålberg, Peter; Hellman, Per; Sundin, Anders

    2012-08-01

    The aim was to assess the feasibility of (11)C-5-hydroxy-tryptophan positron emission tomography ((11)C-5-HTP-PET) in the follow-up after radiofrequency ablation (RFA) of liver metastases from neuroendocrine tumors (NETs). Contrast-enhanced computed tomography (CECT) and contrast-enhanced ultrasound (CEUS) are commonly used to evaluate the liver after RFA of NETs. In general, (11)C-5-HTP-PET is more sensitive in the visualization of NETs, but no studies have investigated its role after RFA. Six consecutive patients with liver metastases from NETs were subjected to RFA treatment. All patients underwent baseline imaging before RFA and on two occasions (1-2 and 6-11 months) after RFA. The imaging consisted of (11)C-5-HTP-PET, CEUS and CECT on all three occasions. Thirty RFA areas were evaluated, and residual tumors (RTs) were depicted in eight areas (22%). (11)C-5-HTP-PET depicted RTs after RFA with maximum sensitivity (100%) and specificity (100%), using radiological follow-up as the gold standard. (11)C-5-HTP-PET detected five out of eight RTs earlier than CECT or CEUS. In general, the sensitivity of (11)C-5-HTP-PET exceeded that of CECT and CEUS for early visualization of NET liver metastases. (11)C-5-HTP-PET can be used in the follow-up after RFA for the purpose of detecting RT, and it provides additional information to CEUS and CECT by detecting new lesions. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Pretreatment Staging Positron Emission Tomography/Computed Tomography in Patients With Inflammatory Breast Cancer Influences Radiation Treatment Field Designs

    SciTech Connect

    Walker, Gary V.; Niikura, Naoki; Yang Wei; Rohren, Eric; Valero, Vicente; Woodward, Wendy A.; Alvarez, Ricardo H.; Lucci, Anthony; Ueno, Naoto T.; Buchholz, Thomas A.

    2012-08-01

    Purpose: Positron emission tomography/computed tomography (PET/CT) is increasingly being utilized for staging of inflammatory breast cancer (IBC). The purpose of this study was to define how pretreatment PET/CT studies affected postmastectomy radiation treatment (PMRT) planning decisions for IBC. Methods and Materials: We performed a retrospective analysis of 62 patients diagnosed with IBC between 2004 and 2009, who were treated with PMRT in our institution and who had a staging PET/CT within 3 months of diagnosis. Patients received a baseline physical examination, staging mammography, ultrasonographic examination of breast and draining lymphatics, and chest radiography; most patients also had a bone scan (55 patients), liver imaging (52 patients), breast MRI (46 patients), and chest CT (25 patients). We compared how PET/CT findings affected PMRT, assuming that standard PMRT would target the chest wall, level III axilla, supraclavicular fossa, and internal mammary chain (IMC). Any modification of target volumes, field borders, or dose prescriptions was considered a change. Results: PET/CT detected new areas of disease in 27 of the 62 patients (44%). The areas of additional disease included the breast (1 patient), ipsilateral axilla (1 patient), ipsilateral supraclavicular (4 patients), ipsilateral infraclavicular (1 patient), ipsilateral IMC (5 patients), ipsilateral subpectoral (3 patients), mediastinal (8 patients), other distant/contralateral lymph nodes (15 patients), or bone (6 patients). One patient was found to have a non-breast second primary tumor. The findings of the PET/CT led to changes in PMRT in 11 of 62 patients (17.7%). These changes included additional fields in 5 patients, adjustment of fields in 2 patients, and higher doses to the supraclavicular fossa (2 patients) and IMC (5 patients). Conclusions: For patients with newly diagnosed IBC, pretreatment PET/CT provides important information concerning involvement of locoregional lymph nodes

  6. Pretreatment staging positron emission tomography/computed tomography in patients with inflammatory breast cancer influences radiation treatment field designs.

    PubMed

    Walker, Gary V; Niikura, Naoki; Yang, Wei; Rohren, Eric; Valero, Vicente; Woodward, Wendy A; Alvarez, Ricardo H; Lucci, Anthony; Ueno, Naoto T; Buchholz, Thomas A

    2012-08-01

    Positron emission tomography/computed tomography (PET/CT) is increasingly being utilized for staging of inflammatory breast cancer (IBC). The purpose of this study was to define how pretreatment PET/CT studies affected postmastectomy radiation treatment (PMRT) planning decisions for IBC. We performed a retrospective analysis of 62 patients diagnosed with IBC between 2004 and 2009, who were treated with PMRT in our institution and who had a staging PET/CT within 3 months of diagnosis. Patients received a baseline physical examination, staging mammography, ultrasonographic examination of breast and draining lymphatics, and chest radiography; most patients also had a bone scan (55 patients), liver imaging (52 patients), breast MRI (46 patients), and chest CT (25 patients). We compared how PET/CT findings affected PMRT, assuming that standard PMRT would target the chest wall, level III axilla, supraclavicular fossa, and internal mammary chain (IMC). Any modification of target volumes, field borders, or dose prescriptions was considered a change. PET/CT detected new areas of disease in 27 of the 62 patients (44%). The areas of additional disease included the breast (1 patient), ipsilateral axilla (1 patient), ipsilateral supraclavicular (4 patients), ipsilateral infraclavicular (1 patient), ipsilateral IMC (5 patients), ipsilateral subpectoral (3 patients), mediastinal (8 patients), other distant/contralateral lymph nodes (15 patients), or bone (6 patients). One patient was found to have a non-breast second primary tumor. The findings of the PET/CT led to changes in PMRT in 11 of 62 patients (17.7%). These changes included additional fields in 5 patients, adjustment of fields in 2 patients, and higher doses to the supraclavicular fossa (2 patients) and IMC (5 patients). For patients with newly diagnosed IBC, pretreatment PET/CT provides important information concerning involvement of locoregional lymph nodes, mediastinal lymph nodes, and unsuspected sites of distant

  7. Incidental abnormal FDG uptake in the prostate on 18-fluoro-2-deoxyglucose positron emission tomography-computed tomography scans.

    PubMed

    Kang, Pil Moon; Seo, Won Ik; Lee, Sun Seong; Bae, Sang Kyun; Kwak, Ho Sup; Min, Kweonsik; Kim, Wansuk; Kang, Dong Il

    2014-01-01

    18-fluoro-2-deoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) scans are commonly used for the staging and restaging of various malignancies, such as head and neck, breast, colorectal and gynecological cancers. However, the value of FDG PET/CT for detecting prostate cancer is unknown. The aim of this study was to evaluate the clinical value of incidental prostate 18F-FDG uptake on PET/CT scans. We reviewed 18F-FDG PET/CT scan reports from September 2009 to September 2013, and selected cases that reported focal/diffuse FDG uptake in the prostate. We analyzed the correlation between 18F-FDG PET/CT scan findings and data collected during evaluations such as serum prostate-specific antigen (PSA) levels, digital rectal examination (DRE), transrectal ultrasound (TRUS), and/or biopsy to confirm prostate cancer. Of a total of 18,393 cases, 106 (0.6%) exhibited abnormal hypermetabolism in the prostate. Additional evaluations were performed in 66 patients. Serum PSA levels were not significantly correlated with maximum standardized uptake values (SUVmax) in all patients (rho 0.483, p=0.132). Prostate biopsies were performed in 15 patients, and prostate cancer was confirmed in 11. The median serum PSA level was 4.8 (0.55-7.06) ng/mL and 127.4 (1.06-495) ng/mL in the benign and prostate cancer groups, respectively. The median SUVmax was higher in the prostate cancer group (mean 10.1, range 3.8-24.5) than in the benign group (mean 4.3, range 3.1-8.8), but the difference was not statistically significant (p=0.078). There was no significant correlation between SUVmax and serum PSA, prostatic volume, or Gleason score. 18F-FDG PET/CT scans did not reliably differentiate malignant or benign from abnormal uptake lesions in the prostate, and routine prostate biopsy was not usually recommended in patients with abnormal FDG uptake. Nevertheless, patients with incidental prostate uptake on 18F-FDG PET/ CT scans should not be ignored and should be undergo

  8. An atlas of Doppler emission-line tomography of cataclysmic variable stars

    NASA Technical Reports Server (NTRS)

    Kaitchuck, Ronald H.; Schlegel, Eric M.; Honeycutt, R. Kent; Horne, Keith; Marsh, T. R.; White, J. C., II; Mansperger, Cathy S.

    1994-01-01

    Doppler emission-line tomography is a technique similar to medical tomography. In this atlas the emission-line profiles of cataclysmic variable stars, seen at different orbital phases, are transformed into velocity space images. This transformation makes many of the complex line profile changes easier to interpret. The emission contributions of the disk and the s-wave are clearly separated in these images, and any emission from the stream and the secondary star can often be identified. In this atlas, Doppler tomograms of Hbeta, He I lambda 4471, and He II lambda 4686 emission lines of 18 cataclysmic variable stars are presented. The Doppler images provide insights into the individual systems and a better technique for measuring and radial velocity amplitude of the white dwarf.

  9. Infantile spasms: III. Prognostic implications of bitemporal hypometabolism on positron emission tomography.

    PubMed

    Chugani, H T; Da Silva, E; Chugani, D C

    1996-05-01

    Positron emission tomography (PET) of brain glucose utilization is highly sensitive in detecting focal cortical abnormalities in patients with infantile spasms even when the computed tomographic (CT) and magnetic resonance imaging (MRI) scans are normal. Of 110 infants with spasms evaluated for potential surgical intervention during an 8-year period, we encountered 18 infants (7 males, 11 females; age range, 10 mo to 5 yr) with a common metabolic pattern on positron emission tomography (PET) consisting of bilateral hypometabolism in the temporal lobes. CT and MRI scans did not reveal any focal abnormalities in the 18 infants. Video-electroencephalographic monitoring indicated either bilateral or multifocal epileptogenicity, or failed to show any epileptic focus, so that none of the 18 infants were considered candidates for resective surgery. These patients were then enrolled in a prospective study aimed at determining long-term outcome in the presence of bilateral temporal PET hypometabolism. Analysis of outcome in 14 of the 18 subjects (follow-up period, 10 mo to 10 yr 5 mo; mean, 3 yr 11 mo +/- 2 yr 4 mo [SD]) revealed the following: (1) all had severe developmental delay and had failed to gain significant milestones; (2) language development had been minimal or absent; (3) 10 of the 14 met the DSM-IV criteria for autistic disorder. Our findings indicate that patients with infantile spasms and bitemporal glucose hypometabolism on PET comprise a relatively homogeneous group and are typically not candidates for cortical resection. The long-term outcome of these infants is particularly poor and the majority are autistic.

  10. Whole-body 18F-fluorodeoxyglucose positron emission tomography/computed tomography images before and after chemotherapy for Kaposi sarcoma and highly active antiretrovirus therapy.

    PubMed

    Morooka, Miyako; Ito, Kimiteru; Kubota, Kazuo; Minamimoto, Ryogo; Shida, Yoshitaka; Hasuo, Kanehiro; Ito, Tateki; Tasato, Daisuke; Honda, Haruhito; Teruya, Katsuji; Kikuchi, Yoshimi; Ohtomo, Kuni

    2010-12-01

    Kaposi sarcoma is an acquired immunodeficiency syndrome-related disease that mainly involves the skin, gastrointestinal gut, and lungs. Whole-body 18F-fluorodeoxyglucose-positron emission tomography and computed tomography (FDG-PET/CT) scanning is useful for simultaneous detection of multiple lesions of Kaposi sarcoma. We present a 67-year-old man with a history of infection with human immunodeficiency virus who presented with numerous cutaneous lesions. FDG-PET/CT images showed lesions in the skin, lung, and lymph nodes. The gastrointestinal lesions were detected using gastric fiberscopy (GF) and colon fiberscopy (CF). After Kaposi sarcoma therapy, the uptake in the lesions of the skin, lung, and lymph nodes decreased, but new lesions were detected in the pancreas and lumbar spine. He had pancreatitis and Candida spondilitis. Whole-body FDG-PET/CT is useful for detecting lesions and determining the extension to which the disease has spread, adding the gastrointestinal lesions by GF and CF. After therapy, FDG-PET/CT can be used to demonstrate which lesions remain active and to determine the overall response to treatment. In this case, we show how useful FDG-PET/CT is and how difficult it is to treat Kaposi sarcoma.

  11. Positron-emission tomography of brain regions activated by recognition of familiar music.

    PubMed

    Satoh, M; Takeda, K; Nagata, K; Shimosegawa, E; Kuzuhara, S

    2006-05-01

    We can easily recognize familiar music by listening to only one or 2 of its opening bars, but the brain regions that participate in this cognitive processing remain undetermined. We used positron-emission tomography (PET) to study changes in regional cerebral blood flow (rCBF) that occur during listening to familiar music. We used a PET subtraction technique to elucidate the brain regions associated with the recognition of familiar melodies such as well-known nursery tunes. Nonmusicians performed 2 kinds of musical tasks: judging the familiarity of musical pieces (familiarity task) and detecting deliberately altered notes in the pieces (alteration-detecting task). During the familiarity task, bilateral anterior portions of bilateral temporal lobes, superior temporal regions, and parahippocampal gyri were activated. The alteration-detecting task bilaterally activated regions in the precunei, superior/inferior parietal lobules, and lateral surface of frontal lobes, which seemed to show a correlation with the analysis of music. We hypothesize that during the familiarity task, activated brain regions participate in retrieval from long-term memory and verbal and emotional processing of familiar melodies. Our results reinforced the hypothesis reported in the literature as a result of group and case studies, that temporal lobe regions participate in the recognition of familiar melodies.

  12. Early Dose Response to Yttrium-90 Microsphere Treatment of Metastatic Liver Cancer by a Patient-Specific Method Using Single Photon Emission Computed Tomography and Positron Emission Tomography

    SciTech Connect

    Campbell, Janice M. Wong, C. Oliver; Muzik, Otto; Marples, Brian; Joiner, Michael; Burmeister, Jay

    2009-05-01

    Purpose: To evaluate a patient-specific single photon emission computed tomography (SPECT)-based method of dose calculation for treatment planning of yttrium-90 ({sup 90}Y) microsphere selective internal radiotherapy (SIRT). Methods and Materials: Fourteen consecutive {sup 90}Y SIRTs for colorectal liver metastasis were retrospectively analyzed. Absorbed dose to tumor and normal liver tissue was calculated by partition methods with two different tumor/normal liver vascularity ratios: an average 3:1 and a patient-specific ratio derived from pretreatment technetium-99m macroaggregated albumin SPECT. Tumor response was quantitatively evaluated from fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography scans. Results: Positron emission tomography showed a significant decrease in total tumor standardized uptake value (average, 52%). There was a significant difference in the tumor absorbed dose between the average and specific methods (p = 0.009). Response vs. dose curves fit by linear and linear-quadratic modeling showed similar results. Linear fit r values increased for all tumor response parameters with the specific method (+0.20 for mean standardized uptake value). Conclusion: Tumor dose calculated with the patient-specific method was more predictive of response in liver-directed {sup 90}Y SIRT.

  13. Graphics processing unit (GPU)-accelerated particle filter framework for positron emission tomography image reconstruction.

    PubMed

    Yu, Fengchao; Liu, Huafeng; Hu, Zhenghui; Shi, Pengcheng

    2012-04-01

    As a consequence of the random nature of photon emissions and detections, the data collected by a positron emission tomography (PET) imaging system can be shown to be Poisson distributed. Meanwhile, there have been considerable efforts within the tracer kinetic modeling communities aimed at establishing the relationship between the PET data and physiological parameters that affect the uptake and metabolism of the tracer. Both statistical and physiological models are important to PET reconstruction. The majority of previous efforts are based on simplified, nonphysical mathematical expression, such as Poisson modeling of the measured data, which is, on the whole, completed without consideration of the underlying physiology. In this paper, we proposed a graphics processing unit (GPU)-accelerated reconstruction strategy that can take both statistical model and physiological model into consideration with the aid of state-space evolution equations. The proposed strategy formulates the organ activity distribution through tracer kinetics models and the photon-counting measurements through observation equations, thus making it possible to unify these two constraints into a general framework. In order to accelerate reconstruction, GPU-based parallel computing is introduced. Experiments of Zubal-thorax-phantom data, Monte Carlo simulated phantom data, and real phantom data show the power of the method. Furthermore, thanks to the computing power of the GPU, the reconstruction time is practical for clinical application.

  14. Magnetic resonance-based motion correction for positron emission tomography imaging.

    PubMed

    Ouyang, Jinsong; Li, Quanzheng; El Fakhri, Georges

    2013-01-01

    Positron emission tomography (PET) image quality is limited by patient motion. Emission data are blurred owing to cardiac and/or respiratory motion. Although spatial resolution is 4 mm for standard clinical whole-body PET scanners, the effective resolution can be as low as 1 cm owing to motion. Additionally, the deformation of attenuation medium causes image artifacts. Previously, gating has been used to "freeze" the motion, but led to significantly increased noise level. Simultaneous PET/magnetic resonance (MR) modality offers a new way to perform PET motion correction. MR can be used to measure 3-dimensional motion fields, which can then be incorporated into the iterative PET reconstruction to obtain motion-corrected PET images. In this report, we present MR imaging techniques to acquire dynamic images, a nonrigid image registration algorithm to extract motion fields from acquired MR images, and a PET reconstruction algorithm with motion correction. We also present results from both phantom and in vivo animal PET/MR studies. We demonstrate that MR-based PET motion correction using simultaneous PET/MR improves image quality and lesion detectability compared with gating and no motion correction. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Bilateral diffuse