The efficacy of preoperative positron emission tomography-computed tomography (PET-CT) for detection of lymph node metastasis in cervical and endometrial cancer: clinical and pathological factors influencing it.

PubMed

Nogami, Yuya; Banno, Kouji; Irie, Haruko; Iida, Miho; Kisu, Iori; Masugi, Yohei; Tanaka, Kyoko; Tominaga, Eiichiro; Okuda, Shigeo; Murakami, Koji; Aoki, Daisuke

2015-01-01

We studied the diagnostic performance of (18)F-fluoro-2-deoxy-d-glucose-positron emission tomography/computed tomography in cervical and endometrial cancers with particular focus on lymph node metastases. Seventy patients with cervical cancer and 53 with endometrial cancer were imaged with (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography before lymphadenectomy. We evaluated the diagnostic performance of (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography using the final pathological diagnoses as the golden standard. We calculated the sensitivity, specificity, positive predictive value and negative predictive value of (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography. In cervical cancer, the results evaluated by cases were 33.3, 92.7, 55.6 and 83.6%, respectively. When evaluated by the area of lymph nodes, the results were 30.6, 98.9, 55.0 and 97.0%, respectively. As for endometrial cancer, the results evaluated by cases were 50.0, 93.9, 40.0 and 95.8%, and by area of lymph nodes, 45.0, 99.4, 64.3 and 98.5%, respectively. The limitation of the efficacy was found out by analyzing it by the region of the lymph node, the size of metastatic node, the historical type of tumor in cervical cancer and the prevalence of lymph node metastasis. The efficacy of positron emission tomography/computed tomography regarding the detection of lymph node metastasis in cervical and endometrial cancer is not established and has limitations associated with the region of the lymph node, the size of metastasis lesion in lymph node and the pathological type of primary tumor. The indication for the imaging and the interpretation of the results requires consideration for each case by the pretest probability based on the information obtained preoperatively. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Positron Computed Tomography: Current State, Clinical Results and Future Trends

DOE R&D Accomplishments Database

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

1980-09-01

An overview is presented of positron computed tomography: its advantages over single photon emission tomography, its use in metabolic studies of the heart and chemical investigation of the brain, and future trends. (ACR)

Advanced imaging in COPD: insights into pulmonary pathophysiology

PubMed Central

Milne, Stephen

2014-01-01

Chronic obstructive pulmonary disease (COPD) involves a complex interaction of structural and functional abnormalities. The two have long been studied in isolation. However, advanced imaging techniques allow us to simultaneously assess pathological processes and their physiological consequences. This review gives a comprehensive account of the various advanced imaging modalities used to study COPD, including computed tomography (CT), magnetic resonance imaging (MRI), and the nuclear medicine techniques positron emission tomography (PET) and single-photon emission computed tomography (SPECT). Some more recent developments in imaging technology, including micro-CT, synchrotron imaging, optical coherence tomography (OCT) and electrical impedance tomography (EIT), are also described. The authors identify the pathophysiological insights gained from these techniques, and speculate on the future role of advanced imaging in both clinical and research settings. PMID:25478198

The predictive value of 18F-FDG PET for pathological response of primary tumor in patients with esophageal cancer during or after neoadjuvant chemoradiotherapy: a meta-analysis.

PubMed

Cong, Lihong; Wang, Shikun; Gao, Teng; Hu, Likuan

2016-12-01

We want to review the value of 18-fluoro-deoxy-glucose positron emission tomography for response prediction of primary tumor in patients with esophageal cancer during or after neoadjuvant chemoradiotherapy. Studies were searched in Pubmed, Embase and Cochrane Library with specific search strategy. The published articles were included according to the criteria established in advance. The included studies were divided into two groups according to the time of the repeat positron emission tomography: during (Group A) or after neoadjuvant chemoradiotherapy (Group B). The studies that performed the repeat positron emission tomography after neoadjuvant chemoradiotherapy were graded Quality Assessment of Diagnostic Accuracy Studies. The pooled sensitivity, specificity and diagnostic odds ratio were obtained for both groups on the basis of no-existing of threshold effect. Fifteen studies were included in the present study. The threshold effect did not exist in both groups. The pooled sensitivity, specificity and diagnostic odds ratio were 85%, 59%, 6.82 with 95% confidence interval 76-91%, 48-69%, 2.25-20.72 in Group A. The equivalent values were 67%, 69%, 6.34 with 95% confidence interval 60-73%, 63-74%, 2.08-19.34 in Group B. The pooled sensitivity was 90% in four studies that enrolled patients with esophageal squamous cell carcinoma merely in Group B. According to the present data, positron emission tomography should not be used routinely to guide treatment strategy in esophageal cancer patients. We speculated that positron emission tomography could be used as a tool to predict treatment response after neoadjuvant chemoradiotherapy in patients with esophageal squamous cell carcinoma. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Positron emission tomography

NASA Astrophysics Data System (ADS)

Yamamoto, Y. Lucas; Thompson, Christopher J.; Diksic, Mirko; Meyer, Ernest; Feindel, William H.

One of the most exciting new technologies introduced in the last 10 yr is positron emission tomography (PET). PET provides quantitative, three-dimensional images for the study of specific biochemical and physiological processes in the human body. This approach is analogous to quantitative in-vivo autoradiography but has the added advantage of permitting non-invasive in vivo studies. PET scanning requires a small cyclotron to produce short-lived positron emitting isotopes such as oxygen-15, carbon-11, nitrogen-13 and fluorine-18. Proper radiochemical facilities and advanced computer equipment are also needed. Most important, PET requires a multidisciplinary scientific team of physicists, radiochemists, mathematicians, biochemists and physicians. This review analyzes the most recent trends in the imaging technology, radiochemistry, methodology and clinical applications of positron emission tomography.

Investigation of Abnormal Left Temporal Functioning in Dyslexia through rCBF, Auditory Evoked Potentials, and Positron Emission Tomography.

ERIC Educational Resources Information Center

Wood, Frank; And Others

1991-01-01

Investigates the proposed left hemisphere dysfunction in dyslexia by reviewing four studies using regional cerebral blood flow (RCBF) and combined auditory evoked responses with positron emission tomography. Emphasizes methodological issues. Finds that dyslexics showed a positive correlation between Heschl's gyrus activation and phonemic…

Carbon-11-Pittsburgh compound B positron emission tomography imaging of amyloid deposition in presenilin 1 mutation carriers.

PubMed

Knight, William D; Okello, Aren A; Ryan, Natalie S; Turkheimer, Federico E; Rodríguez Martinez de Llano, Sofia; Edison, Paul; Douglas, Jane; Fox, Nick C; Brooks, David J; Rossor, Martin N

2011-01-01

(11)Carbon-Pittsburgh compound B positron emission tomography studies have suggested early and prominent amyloid deposition in the striatum in presenilin 1 mutation carriers. This cross-sectional study examines the (11)Carbon-Pittsburgh compound B positron emission tomography imaging profiles of presymptomatic and mildly affected (mini-mental state examination ≥ 20) carriers of seven presenilin 1 mutations, comparing them with groups of controls and symptomatic sporadic Alzheimer's disease cases. Parametric ratio images representing (11)Carbon-Pittsburgh compound B retention from 60 to 90 min were created using the pons as a reference region and nine regions of interest were studied. We confirmed that increased amyloid load may be detected in presymptomatic presenilin 1 mutation carriers with (11)Carbon-Pittsburgh compound B positron emission tomography and that the pattern of retention is heterogeneous. Comparison of presenilin 1 and sporadic Alzheimer's disease groups revealed significantly greater thalamic retention in the presenilin 1 group and significantly greater frontotemporal retention in the sporadic Alzheimer's disease group. A few individuals with presenilin 1 mutations showed increased cerebellar (11)Carbon-Pittsburgh compound B retention suggesting that this region may not be as suitable a reference region in familial Alzheimer's disease.

Positron Emission Tomography (PET) and Positron Scanning

Science.gov Websites

National Laboratory 'Positron Emission Tomography ... [is a medical imaging technique that] can track human brain.' Edited excerpts from from Medical Applications of Non-Medical Research: Applications Technical Report, November 1988 High-resolution PET (Positron Emission Tomography) for Medical Science

Data analysis in emission tomography using emission-count posteriors

NASA Astrophysics Data System (ADS)

Sitek, Arkadiusz

2012-11-01

A novel approach to the analysis of emission tomography data using the posterior probability of the number of emissions per voxel (emission count) conditioned on acquired tomographic data is explored. The posterior is derived from the prior and the Poisson likelihood of the emission-count data by marginalizing voxel activities. Based on emission-count posteriors, examples of Bayesian analysis including estimation and classification tasks in emission tomography are provided. The application of the method to computer simulations of 2D tomography is demonstrated. In particular, the minimum-mean-square-error point estimator of the emission count is demonstrated. The process of finding this estimator can be considered as a tomographic image reconstruction technique since the estimates of the number of emissions per voxel divided by voxel sensitivities and acquisition time are the estimates of the voxel activities. As an example of a classification task, a hypothesis stating that some region of interest (ROI) emitted at least or at most r-times the number of events in some other ROI is tested. The ROIs are specified by the user. The analysis described in this work provides new quantitative statistical measures that can be used in decision making in diagnostic imaging using emission tomography.

Cerebral perfusion imaging in Alzheimer's disease. Use of single photon emission computed tomography and iofetamine hydrochloride I 123

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, K.A.; Mueller, S.T.; Walshe, T.M.

1987-02-01

We used single photon emission computed tomography (SPECT) to study 15 patients with Alzheimer's disease and nine controls. Iofetamine hydrochloride I 123 uptake data were recorded from the entire brain using a rotating gamma camera. Activity ratios were measured for the frontal, posterior parietal, posterior, medial, and lateral cortical temporal regions and striate cortex and were normalized by the activity in the cerebellum. Abnormalities in iofetamine hydrochloride I 123 activity were similar to the abnormalities in glucose metabolism observed with positron emission tomography. Cortical tracer activity was globally depressed in patients with Alzheimer's disease, with the greatest reduction in themore » posterior parietal cortex.« less

Independent information from cerebrospinal fluid amyloid-β and florbetapir imaging in Alzheimer's disease.

PubMed

Mattsson, Niklas; Insel, Philip S; Donohue, Michael; Landau, Susan; Jagust, William J; Shaw, Leslie M; Trojanowski, John Q; Zetterberg, Henrik; Blennow, Kaj; Weiner, Michael W

2015-03-01

Reduced cerebrospinal fluid amyloid-β42 and increased retention of florbetapir positron emission tomography are biomarkers reflecting cortical amyloid load in Alzheimer's disease. However, these measurements do not always agree and may represent partly different aspects of the underlying Alzheimer's disease pathology. The goal of this study was therefore to test if cerebrospinal fluid and positron emission tomography amyloid-β biomarkers are independently related to other Alzheimer's disease markers, and to examine individuals who are discordantly classified by these two biomarker modalities. Cerebrospinal fluid and positron emission tomography amyloid-β were measured at baseline in 769 persons [161 healthy controls, 68 subjective memory complaints, 419 mild cognitive impairment and 121 Alzheimer's disease dementia, mean age 72 years (standard deviation 7 years), 47% females] and used to predict diagnosis, APOE ε4 carriage status, cerebral blood flow, cerebrospinal fluid total-tau and phosphorylated-tau levels (cross-sectionally); and hippocampal volume, fluorodeoxyglucose positron emission tomography results and Alzheimer's Disease Assessment Scale-cognitive subscale scores (longitudinally). Cerebrospinal fluid and positron emission tomography amyloid-β were highly correlated, but adjusting one of these predictors for the other revealed that they both provided partially independent information when predicting diagnosis, APOE ε4, hippocampal volume, metabolism, cognition, total-tau and phosphorylated-tau (the 95% confidence intervals of the adjusted effects did not include zero). Cerebrospinal fluid amyloid-β was more strongly related to APOE ε4 whereas positron emission tomography amyloid-β was more strongly related to tau levels (P < 0.05). Discordance (mainly isolated cerebrospinal fluid amyloid-β positivity) differed by diagnostic group (P < 0.001) and was seen in 21% of cognitively healthy people but only 6% in dementia patients. The finding that cerebrospinal fluid and positron emission tomography amyloid-β provide partially independent information about a wide range of Alzheimer's measures supports the theory that these modalities represent partly different aspects of Alzheimer's pathology. The fact that mismatch, with positive cerebrospinal fluid amyloid-β but normal positron emission tomography amyloid-β, is relatively common in cognitively healthy people may be considered when using these biomarkers to identify early stage Alzheimer's disease. Reduced cerebrospinal fluid amyloid-β may be more strongly related to early stage Alzheimer's disease, whereas increased positron emission tomography amyloid-β may be more strongly related to disease progression. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

11C-Methionine Positron Emission Tomography/Computed Tomography Versus 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Evaluation of Residual or Recurrent World Health Organization Grades II and III Meningioma After Treatment.

PubMed

Tomura, Noriaki; Saginoya, Toshiyuki; Goto, Hiromi

2018-04-02

The aim of this study was to determine the assessment of positron emission tomography-computed tomography using C-methionine (MET PET/CT) for World Health Organization (WHO) grades II and III meningiomas; MET PET/CT was compared with PET/CT using F-fluorodeoxy glucose (FDG PET/CT). This study was performed in 17 cases with residual and/or recurrent WHO grades II and III meningiomas. Two neuroradiologists reviewed both PET/CT scans. For agreement, the κ coefficient was measured. Difference in tumor-to-normal brain uptake ratios (T/N ratios) between 2 PET/CT scans was analyzed. Correlation between the maximum tumor size and T/N ratio in PET/CT was studied. For agreement by both reviewers, the κ coefficient was 0.51 (P < 0.05). The T/N ratio was significantly higher for MET PET/CT (3.24 ± 1.36) than for FDG PET/CT (0.93 ± 0.44) (P < 0.01). C-methionine ratio significantly correlated with tumor size (y = 8.1x + 16.3, n = 22, P < 0.05), but FDG ratio did not CONCLUSIONS: C-methionine PET/CT has superior potential for imaging of WHO grades II and III meningiomas with residual or recurrent tumors compared with FDG PET/CT.

MRI and 18F-fluorodeoxyglucose positron emission tomography in hemimegalencephaly.

PubMed

Hoffmann, K T; Amthauer, H; Liebig, T; Hosten, N; Etou, A; Lehmann, T N; Farahati, J; Felix, R

2000-10-01

We report hemimegalencephaly in a 44-year-old woman with mental retardation, epilepsy and a mild hemiparesis. In addition to typical findings on MRI, 2-deoxy-2[18F]fluorodeoxyglucose positron-emission tomography (PET) demonstrated glucose hypometabolism of the affected hemisphere. The results of PET have been coregistered with morphological information from the MRI studies by image fusion.

F18 FDG positron emission tomography revelation of primary testicular lymphoma with concurrent multiple extra nodal involvement

PubMed Central

Vamsy, Mohana; Dattatreya, PS; Parakh, Megha; Dayal, Monal; Rao, VVS Prabhakar

2013-01-01

Primary testicular lymphoma (PTL) a relatively rare disease of non-Hodgkin's lymphomas occurring with a lesser incidence of 1-2% has a propensity to occur at later ages above 50 years. PTL spreads to extra nodal sites due to deficiency of extra cellular adhesion molecules. We present detection of multiple sites of extra nodal involvement of PTL by F-18 positron emission tomography/computed tomography study aiding early detection of the dissemination thus aiding in staging and management. PMID:24019676

Meta-Analysis of Stress Myocardial Perfusion Imaging

ClinicalTrials.gov

2017-06-06

Coronary Disease; Echocardiography; Fractional Flow Reserve, Myocardial; Hemodynamics; Humans; Magnetic Resonance Imaging; Myocardial Perfusion Imaging; Perfusion; Predictive Value of Tests; Single Photon Emission Computed Tomography; Positron Emission Tomography; Multidetector Computed Tomography; Echocardiography, Stress; Coronary Angiography

Emission Computed Tomography: A New Technique for the Quantitative Physiologic Study of Brain and Heart in Vivo

DOE R&D Accomplishments Database

Phelps, M. E.; Hoffman, E. J.; Huang, S. C.; Schelbert, H. R.; Kuhl, D. E.

1978-01-01

Emission computed tomography can provide a quantitative in vivo measurement of regional tissue radionuclide tracer concentrations. This facility when combined with physiologic models and radioactively labeled physiologic tracers that behave in a predictable manner allow measurement of a wide variety of physiologic variables. This integrated technique has been referred to as Physiologic Tomography (PT). PT requires labeled compounds which trace physiologic processes in a known and predictable manner, and physiologic models which are appropriately formulated and validated to derive physiologic variables from ECT data. In order to effectively achieve this goal, PT requires an ECT system that is capable of performing truly quantitative or analytical measurements of tissue tracer concentrations and which has been well characterized in terms of spatial resolution, sensitivity and signal to noise ratios in the tomographic image. This paper illustrates the capabilities of emission computed tomography and provides examples of physiologic tomography for the regional measurement of cerebral and myocardial metabolic rate for glucose, regional measurement of cerebral blood volume, gated cardiac blood pools and capillary perfusion in brain and heart. Studies on patients with stroke and myocardial ischemia are also presented.

Nonmetastatic Castration-resistant Prostate Cancer: A Modern Perspective.

PubMed

Cancian, Madeline; Renzulli, Joseph F

2018-06-01

Nonmetastatic castration-resistant prostate cancer (nmCRPC) presents a challenge to urologists as currently there are no Food and Drug Administration-approved therapies. However, there are new imaging modalities, including fluciclovine positron emission tomography-computed tomography and Ga-PSMA (prostate specific membrane antigent) positron emission tomography-computed tomography, which are improving accuracy of diagnosis. With improved imaging, we are better able to target therapy. Today there are 3 ongoing clinical trials studying second-generation antiandrogens in nmCRPC, which hold the promise of a new treatment paradigm. In this article, we will review the new imaging techniques and the rationale behind novel treatment modalities in nmCRPC. Copyright © 2018 Elsevier Inc. All rights reserved.

18F-Labeling of Sensitive Biomolecules for Positron Emission Tomography

PubMed Central

Krishnan, Hema S.; Ma, Longle; Vasdev, Neil; Liang, Steven H.

2017-01-01

Positron emission tomography (PET) imaging study of fluorine-18 labeled biomolecules is an emerging and rapidly growing area for preclinical and clinical research. The present review focuses on recent advances in radiochemical methods for incorporating fluorine-18 into biomolecules via ‘direct’ or ‘indirect’ bioconjugation. Recently developed prosthetic groups and pre-targeting strategies, as well as representative examples in 18F-labeling of biomolecules in PET imaging research studies are highlighted. PMID:28704575

Tomography of a simply magnetized toroidal plasma

NASA Astrophysics Data System (ADS)

Ruggero, BARNI; Stefano, CALDIROLA; Luca, FATTORINI; Claudia, RICCARDI

2018-02-01

Optical emission spectroscopy is a passive diagnostic technique, which does not perturb the plasma state. In particular, in a hydrogen plasma, Balmer-alpha (H α ) emission can be easily measured in the visible range along a line of sight from outside the plasma vessel. Other emission lines in the visible spectral range from hydrogen atoms and molecules can be exploited too, in order to gather complementary pieces of information on the plasma state. Tomography allows us to capture bi-dimensional structures. We propose to adopt an emission spectroscopy tomography for studying the transverse profiles of magnetized plasmas when Abel inversion is not exploitable. An experimental campaign was carried out at the Thorello device, a simple magnetized torus. The characteristics of the profile extraction method, which we implemented for this purpose are discussed, together with a few results concerning the plasma profiles in a simply magnetized torus configuration.

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.

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

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

Are We Ready for Positron Emission Tomography/Computed Tomography-based Target Volume Definition in Lymphoma Radiation Therapy?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeoh, Kheng-Wei; Mikhaeel, N. George, E-mail: George.Mikhaeel@gstt.nhs.uk

2013-01-01

Fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) has become indispensable for the clinical management of lymphomas. With consistent evidence that it is more accurate than anatomic imaging in the staging and response assessment of many lymphoma subtypes, its utility continues to increase. There have therefore been efforts to incorporate PET/CT data into radiation therapy decision making and in the planning process. Further, there have also been studies investigating target volume definition for radiation therapy using PET/CT data. This article will critically review the literature and ongoing studies on the above topics, examining the value and methods of adding PET/CTmore » data to the radiation therapy treatment algorithm. We will also discuss the various challenges and the areas where more evidence is required.« less

18 F-Labeling of Sensitive Biomolecules for Positron Emission Tomography.

PubMed

Krishnan, Hema S; Ma, Longle; Vasdev, Neil; Liang, Steven H

2017-11-07

Positron emission tomography (PET) imaging study of fluorine-18 labeled biomolecules is an emerging and rapidly growing area for preclinical and clinical research. The present review focuses on recent advances in radiochemical methods for incorporating fluorine-18 into biomolecules via "direct" or "indirect" bioconjugation. Recently developed prosthetic groups and pre-targeting strategies, as well as representative examples in 18 F-labeling of biomolecules in PET imaging research studies are highlighted. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

2018-01-01

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.

Ion beam induced 18F-radiofluorination: straightforward synthesis of gaseous radiotracers for the assessment of regional lung ventilation using positron emission tomography.

PubMed

Gómez-Vallejo, V; Lekuona, A; Baz, Z; Szczupak, B; Cossío, U; Llop, J

2016-09-29

A simple, straightforward and efficient method for the synthesis of [ 18 F]CF 4 and [ 18 F]SF 6 based on an ion beam-induced isotopic exchange reaction is presented. Positron emission tomography ventilation studies in rodents using [ 18 F]CF 4 showed a uniform distribution of the radiofluorinated gas within the lungs and rapid elimination after discontinuation of the administration.

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.

FDG-PET/CT in the evaluation of anal carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cotter, Shane E.; Medical Scientist Training Program, Washington University School of Medicine, St. Louis, MO; Grigsby, Perry W.

2006-07-01

Purpose: Surgical staging and treatment of anal carcinoma has been replaced by noninvasive staging studies and combined modality therapy. In this study, we compare computed tomography (CT) and physical examination to [{sup 18}F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) in the staging of carcinoma of the anal canal, with special emphasis on determination of spread to inguinal lymph nodes. Methods and Materials: Between July 2003 and July 2005, 41 consecutive patients with biopsy-proved anal carcinoma underwent a complete staging evaluation including physical examination, CT, and 2-FDG-PET/CT. Patients ranged in age from 30 to 89 years. Nine men were HIV-positive. Treatment was withmore » standard Nigro regimen. Results: [{sup 18}F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) detected 91% of nonexcised primary tumors, whereas CT visualized 59%. FDG-PET/CT detected abnormal uptake in pelvic nodes of 5 patients with normal pelvic CT scans. FDG-PET/CT detected abnormal nodes in 20% of groins that were normal by CT, and in 23% without abnormality on physical examination. Furthermore, 17% of groins negative by both CT and physical examination showed abnormal uptake on FDG-PET/CT. HIV-positive patients had an increased frequency of PET-positive lymph nodes. Conclusion: [{sup 18}F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography detects the primary tumor more often than CT. FDG-PET/CT detects substantially more abnormal inguinal lymph nodes than are identified by standard clinical staging with CT and physical examination.« less

Cholangiocarcinoma associated with limbic encephalitis and early cerebral abnormalities detected by 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography-positron emission tomography: a case report.

PubMed

Schmidt, Sergio L; Schmidt, Juliana J; Tolentino, Julio C; Ferreira, Carlos G; de Almeida, Sergio A; Alvarenga, Regina P; Simoes, Eunice N; Schmidt, Guilherme J; Canedo, Nathalie H S; Chimelli, Leila

2016-07-20

Limbic encephalitis was originally described as a rare clinical neuropathological entity involving seizures and neuropsychological disturbances. In this report, we describe cerebral patterns visualized by positron emission tomography in a patient with limbic encephalitis and cholangiocarcinoma. To our knowledge, there is no other description in the literature of cerebral positron emission tomography findings in the setting of limbic encephalitis and subsequent diagnosis of cholangiocarcinoma. We describe a case of a 77-year-old Caucasian man who exhibited persistent cognitive changes 2 years before his death. A cerebral scan obtained at that time by 2-deoxy-2-[fluorine-18]fluoro- D -glucose integrated with computed tomography-positron emission tomography showed low radiotracer uptake in the frontal and temporal lobes. Cerebrospinal fluid analysis indicated the presence of voltage-gated potassium channel antibodies. Three months before the patient's death, a lymph node biopsy indicated a cholangiocarcinoma, and a new cerebral scan obtained by 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography-positron emission tomography showed an increment in the severity of metabolic deficit in the frontal and parietal lobes, as well as hypometabolism involving the temporal lobes. Two months before the patient's death, cerebral metastases were detected on a contrast-enhanced computed tomographic scan. Postmortem examination revealed a cholangiocarcinoma with multiple metastases including the lungs and lymph nodes. The patient's brain weighed 1300 g, and mild cortical atrophy, ex vacuo dilation of the ventricles, and mild focal thickening of the cerebellar leptomeninges, which were infiltrated by neoplastic epithelial cells, were observed. These findings support the need for continued vigilance in malignancy surveillance in patients with limbic encephalitis and early cerebral positron emission tomographic scan abnormalities. The difficulty in early diagnosis of small tumors, such as a cholangiocarcinoma, is discussed in the context of the clinical utility of early cerebral hypometabolism detected by 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography-positron emission tomography in patients with rapidly progressive dementia.

Neurobiology of Chronic Stress-Related Psychiatric Disorders: Evidence from Molecular Imaging Studies

PubMed Central

Davis, Margaret T.; Holmes, Sophie E.; Pietrzak, Robert H.; Esterlis, Irina

2018-01-01

Chronic stress accounts for billions of dollars of economic loss annually in the United States alone, and is recognized as a major source of disability and mortality worldwide. Robust evidence suggests that chronic stress plays a significant role in the onset of severe and impairing psychiatric conditions, including major depressive disorder, bipolar disorder, and posttraumatic stress disorder. Application of molecular imaging techniques such as positron emission tomography and single photon emission computed tomography in recent years has begun to provide insight into the molecular mechanisms by which chronic stress confers risk for these disorders. The present paper provides a comprehensive review and synthesis of all positron emission tomography and single photon emission computed tomography imaging publications focused on the examination of molecular targets in individuals with major depressive disorder, posttraumatic stress disorder, or bipolar disorder to date. Critical discussion of discrepant findings and broad strengths and weaknesses of the current body of literature is provided. Recommended future directions for the field of molecular imaging to further elucidate the neurobiological substrates of chronic stress-related disorders are also discussed. This article is part of the inaugural issue for the journal focused on various aspects of chronic stress. PMID:29862379

F-18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Appearance of Extramedullary Hematopoesis in a Case of Primary Myelofibrosis

PubMed Central

Mukherjee, Anirban; Bal, Chandrasekhar; Tripathi, Madhavi; Das, Chandan Jyoti; Shamim, Shamim Ahmed

2017-01-01

A 44-year-old female with known primary myelofibrosis presented with shortness of breath. High Resolution Computed Tomography thorax revealed large heterogeneously enhancing extraparenchymal soft tissue density mass involving bilateral lung fields. F-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography revealed mildly FDG avid soft tissue density mass with specks of calcification involving bilateral lung fields, liver, and spleen. Subsequent histopathologic evaluation from the right lung mass was suggestive of extramedullary hematopoesis. PMID:28533647

Limitations of PET/CT in the Detection of Occult N1 Metastasis in Clinical Stage I(T1-2aN0) Non-Small Cell Lung Cancer for Staging Prior to Stereotactic Body Radiotherapy

PubMed Central

Akthar, Adil S.; Ferguson, Mark K.; Koshy, Matthew; Vigneswaran, Wickii T.

2016-01-01

Purpose/Objectives: Patients receiving stereotactic body radiotherapy for stage I non-small cell lung cancer are typically staged clinically with positron emission tomography–computed tomography. Currently, limited data exist for the detection of occult hilar/peribronchial (N1) disease. We hypothesize that positron emission tomography–computed tomography underestimates spread of cancer to N1 lymph nodes and that future stereotactic body radiotherapy patients may benefit from increased pathologic evaluation of N1 nodal stations in addition to N2 nodes. Materials/Methods: A retrospective study was performed of all patients with clinical stage I (T1-2aN0) non-small cell lung cancer (American Joint Committee on Cancer, 7th edition) by positron emission tomography–computed tomography at our institution from 2003 to 2011, with subsequent surgical resection and lymph node staging. Findings on positron emission tomography–computed tomography were compared to pathologic nodal involvement to determine the negative predictive value of positron emission tomography–computed tomography for the detection of N1 nodal disease. An analysis was conducted to identify predictors of occult spread. Results: A total of 105 patients with clinical stage I non-small cell lung cancer were included in this study, of which 8 (7.6%) patients were found to have occult N1 metastasis on pathologic review yielding a negative predictive value for N1 disease of 92.4%. No patients had occult mediastinal nodes. The negative predictive value for positron emission tomography–computed tomography in patients with clinical stage T1 versus T2 tumors was 72 (96%) of 75 versus 25 (83%) of 30, respectively (P = .03), and for peripheral versus central tumor location was 77 (98%) of 78 versus 20 (74%) of 27, respectively (P = .0001). The negative predictive values for peripheral T1 and T2 tumors were 98% and 100%, respectively; while for central T1 and T2 tumors, the rates were 85% and 64%, respectively. Occult lymph node involvement was not associated with primary tumor maximum standard uptake value, histology, grade, or interval between positron emission tomography–computed tomography and surgery. Conclusion: Our results support pathologic assessment of N1 lymph nodes in patients with stage Inon-small cell lung cancer considered for stereotactic body radiotherapy, with the greatest benefit in patients with central and T2 tumors. Diagnostic evaluation with endoscopic bronchial ultrasound should be considered in the evaluation of stereotactic body radiotherapy candidates. PMID:26792491

Positron emission tomography in neurological diseases.

PubMed

Kumar, Sudhir; Rajshekher, G; Prabhakar, Subhashini

2005-06-01

Positron emission tomography (PET) is the study of human physiology by electronic detection of positron-emitting radiopharmaceuticals. It is one of the noninvasive technologies that can measure the metabolic and functional activity of living tissue. Positron emission tomography finds its clinical applications in broadly three specialties--oncology, cardiology, and neurology. The current review focuses on its indications in neurological diseases. Recently published literature on the use of PET in neurology has been thoroughly analyzed. Several reports regarding the usage of PET in epilepsy, stroke, dementia, and movement disorders are available. Positron emission tomography does not appear to be useful as a primary or sole imaging technique in these conditions. On the other hand, it is useful in very specific situations, which have been elaborated in the review. It is also noteworthy that PET is complementary to the computed tomography/magnetic resonance imaging findings and data obtained from combining these modalities can be valuable in situations such as localization of the epileptogenic focus in cases of refractory epilepsy or for prediction of the outcome after thrombolysis in acute ischemic stroke. The major handicaps in widespread use of PET appear to be its lack of availability and its relatively high cost. Nevertheless, a review such as this would be helpful in judiciously selecting those patients who would benefit from undergoing a PET scan, at a time when PET imaging facility is likely to be available soon in the Indian private sector.

Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rumsey, J.M.; Duara, R.; Grady, C.

The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic ratesmore » (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions.« less

Split gradient coils for simultaneous PET-MRI

PubMed Central

Poole, Michael; Bowtell, Richard; Green, Dan; Pittard, Simon; Lucas, Alun; Hawkes, Rob; Carpenter, Adrian

2015-01-01

Combining positron emission tomography (PET) and MRI necessarily involves an engineering tradeoff as the equipment needed for the two modalities vies for the space closest to the region where the signals originate. In one recently described scanner configuration for simultaneous positron emission tomography–MRI, the positron emission tomography detection scintillating crystals reside in an 80-mm gap between the 2 halves of a 1-T split-magnet cryostat. A novel set of gradient and shim coils has been specially designed for this split MRI scanner to include an 110-mm gap from which wires are excluded so as not to interfere with positron detection. An inverse boundary element method was necessarily employed to design the three orthogonal, shielded gradient coils and shielded Z0 shim coil. The coils have been constructed and tested in the hybrid positron emission tomography-MRI system and successfully used in simultaneous positron emission tomography-MRI experiments. PMID:19780167

Ray Tracing Methods in Seismic Emission Tomography

NASA Astrophysics Data System (ADS)

Chebotareva, I. Ya.

2018-03-01

Highly efficient approximate ray tracing techniques which can be used in seismic emission tomography and in other methods requiring a large number of raypaths are described. The techniques are applicable for the gradient and plane-layered velocity sections of the medium and for the models with a complicated geometry of contrasting boundaries. The empirical results obtained with the use of the discussed ray tracing technologies and seismic emission tomography results, as well as the results of numerical modeling, are presented.

Radiolabelling and positron emission tomography of PT70, a time-dependent inhibitor of InhA, the Mycobacterium tuberculosis enoyl-ACP reductase

DOE PAGES

Wang, Hui; Liu, Li; Lu, Yang; ...

2015-07-14

PT70 is a diaryl ether inhibitor of InhA, the enoyl-ACP reductase in the Mycobacterium tuberculosis fatty acid biosynthesis pathway. It has a residence time of 24 min on the target, and also shows antibacterial activity in a mouse model of tuberculosis infection. Due to the interest in studying target tissue pharmacokinetics of PT70, we developed a method to radiolabel PT70 with carbon-11 and have studied its pharmacokinetics in mice and baboons using positron emission tomography.

Radiolabelling and positron emission tomography of PT70, a time-dependent inhibitor of InhA, the Mycobacterium tuberculosis enoyl-ACP reductase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hui; Liu, Li; Lu, Yang

PT70 is a diaryl ether inhibitor of InhA, the enoyl-ACP reductase in the Mycobacterium tuberculosis fatty acid biosynthesis pathway. It has a residence time of 24 min on the target, and also shows antibacterial activity in a mouse model of tuberculosis infection. Due to the interest in studying target tissue pharmacokinetics of PT70, we developed a method to radiolabel PT70 with carbon-11 and have studied its pharmacokinetics in mice and baboons using positron emission tomography.

No-carrier-added labeling of the neuroprotective Ebselen with selenium-73 and selenium-75.

PubMed

Helfer, Andreas; Ermert, Johannes; Humpert, Sven; Coenen, Heinz H

2015-03-01

Selenium-73 is a positron emitting non-standard radionuclide, which is suitable for positron emission tomography. A copper-catalyzed reaction allowed no-carrier-added labeling of the anti-inflammatory seleno-organic compound Ebselen with (73) Se and (75) Se under addition of sulfur carrier in a one-step reaction. The new authentically labeled radioselenium molecule is thus available for preclinical evaluation and positron emission tomography studies. Copyright © 2015 John Wiley & Sons, Ltd.

Occupancy of Norepinephrine Transporter by Duloxetine in Human Brains Measured by Positron Emission Tomography with (S,S)-[18F]FMeNER-D2.

PubMed

Moriguchi, Sho; Takano, Harumasa; Kimura, Yasuyuki; Nagashima, Tomohisa; Takahata, Keisuke; Kubota, Manabu; Kitamura, Soichiro; Ishii, Tatsuya; Ichise, Masanori; Zhang, Ming-Rong; Shimada, Hitoshi; Mimura, Masaru; Meyer, Jeffrey H; Higuchi, Makoto; Suhara, Tetsuya

2017-12-01

The norepinephrine transporter in the brain has been targeted in the treatment of psychiatric disorders. Duloxetine is a serotonin and norepinephrine reuptake inhibitor that has been widely used for the treatment of depression. However, the relationship between dose and plasma concentration of duloxetine and norepinephrine transporter occupancy in the human brain has not been determined. In this study, we examined norepinephrine transporter occupancy by different doses of duloxetine. We calculated norepinephrine transporter occupancies from 2 positron emission tomography scans using (S,S)-[18F]FMeNER-D2 before and after a single oral dose of duloxetine (20 mg, n = 3; 40 mg, n = 3; 60 mg, n =2). Positron emission tomography scans were performed from 120 to 180 minutes after an i.v. bolus injection of (S,S)-[18F]FMeNER-D2. Venous blood samples were taken to measure the plasma concentration of duloxetine just before and after the second positron emission tomography scan. Norepinephrine transporter occupancy by duloxetine was 29.7% at 20 mg, 30.5% at 40 mg, and 40.0% at 60 mg. The estimated dose of duloxetine inducing 50% norepinephrine transporter occupancy was 76.8 mg, and the estimated plasma drug concentration inducing 50% norepinephrine transporter occupancy was 58.0 ng/mL. Norepinephrine transporter occupancy by clinical doses of duloxetine was approximately 30% to 40% in human brain as estimated using positron emission tomography with (S,S)-[18F]FMeNER-D2. © The Author 2017. Published by Oxford University Press on behalf of CINP.

A review of the evidence of zolpidem efficacy in neurological disability after brain damage due to stroke, trauma and hypoxia: A justification of further clinical trials.

PubMed

Sutton, J A; Clauss, R P

2017-01-01

During 15 years, 23 clinical reports and 6 studies have demonstrated associations between sub-sedative doses of zolpidem and recoveries from brain damage due to strokes, trauma and hypoxia. Clinical findings include unexpected awakenings from vegetative states and regressions of stroke symptoms after dosing that disappear during elimination and reappear on repeat dosing. Initially single-photon emission computed tomography scans showed improved perfusion within, around and distant from infarctions. Then positron emission tomography scans and electroencephalography detected renewed metabolic and neuronal activity. Placebo or a similar, gamma-aminobutyric acid (GABA)-ergic, sedative zopiclone has no such effect. The effect appears only several months after the injury, reflecting recent evidence in mice of substantial differences between the states of GABA receptors in acute and chronic repair phases of recovery. Zolpidem's good safety record and rapid absorption further indicate a need for more clinical trials. List of acronyms: BOLD, Blood-Oxygen-Level Dependent contrast imaging in MRI; CRS, Coma Recovery Scale; CRS-R, Coma Recovery Scale Revised; CSI, Cerebral State Index; CSM, Cerebral State Monitor; DOC, Disorder of Consciousness; EEG, Electro Encephalography; FDG-PET, FluoroDeoxyGlucose-Positron Emission Tomography; FTD, Frontotemporal dementia; GABA, Gamma-Aminobutyric Acid; MCS, Minimally Conscious State; M-EEG, Magneto-Encephalography; MRI, Magnetic Resonance Image; MSN, Median Spiny Neurones; PET, Positron Emission Tomography; PVS, Persistent Vegetative Sate; RLAC, Rancho Los Amigos Cognitive scores; SPECT, Single-photon emission computed tomography; TFES, Tinetti Falls Efficacy Scale; 99mTc HMPAO, Technetium hexamethylpropyleneamine oxime.

Positron emission tomography/computerized tomography in lung cancer

PubMed Central

Vural, Gulin Ucmak

2014-01-01

Positron emission tomography (PET) using 2-(18F)-flouro-2-deoxy-D-glucose (FDG) has emerged as a useful tool in the clinical work-up of lung cancer. This review article provides an overview of applications of PET in diagnosis, staging, treatment response evaluation, radiotherapy planning, recurrence assessment and prognostication of lung cancer. PMID:24914421

Anthropomorphic thorax phantom for cardio-respiratory motion simulation in tomographic imaging

NASA Astrophysics Data System (ADS)

Bolwin, Konstantin; Czekalla, Björn; Frohwein, Lynn J.; Büther, Florian; Schäfers, Klaus P.

2018-02-01

Patient motion during medical imaging using techniques such as computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), or single emission computed tomography (SPECT) is well known to degrade images, leading to blurring effects or severe artifacts. Motion correction methods try to overcome these degrading effects. However, they need to be validated under realistic conditions. In this work, a sophisticated anthropomorphic thorax phantom is presented that combines several aspects of a simulator for cardio-respiratory motion. The phantom allows us to simulate various types of cardio-respiratory motions inside a human-like thorax, including features such as inflatable lungs, beating left ventricular myocardium, respiration-induced motion of the left ventricle, moving lung lesions, and moving coronary artery plaques. The phantom is constructed to be MR-compatible. This means that we can not only perform studies in PET, SPECT and CT, but also inside an MRI system. The technical features of the anthropomorphic thorax phantom Wilhelm are presented with regard to simulating motion effects in hybrid emission tomography and radiotherapy. This is supplemented by a study on the detectability of small coronary plaque lesions in PET/CT under the influence of cardio-respiratory motion, and a study on the accuracy of left ventricular blood volumes.

Nuclear Heart Scan

MedlinePlus

... into your blood and travels to your heart. Nuclear heart scans use single photon emission computed tomography (SPECT) or cardiac positron emission tomography (PET) to detect the energy from the tracer to make pictures of your ...

PET and Single-Photon Emission Computed Tomography in Brain Concussion.

PubMed

Raji, Cyrus A; Henderson, Theodore A

2018-02-01

This article offers an overview of the application of PET and single photon emission computed tomography brain imaging to concussion, a type of mild traumatic brain injury and traumatic brain injury, in general. The article reviews the application of these neuronuclear imaging modalities in cross-sectional and longitudinal studies. Additionally, this article frames the current literature with an overview of the basic physics and radiation exposure risks of each modality. Copyright © 2017 Elsevier Inc. All rights reserved.

Radionuclide Ventriculography or Radionuclide Angiography (MUGA Scan)

MedlinePlus

... Attack Heart Failure Myocardial Perfusion Imaging (MPI) Single Photon Emission Computed Tomography (SPECT) Positron Emission Tomography (PET) ... stroke. Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Heart Attack Symptoms in ...

Brain PET scan

MedlinePlus

... tissues are working. Other imaging tests, such as magnetic resonance imaging ( MRI ) and computed tomography ( CT ) scans only reveal ... M, Hellwig S, Kloppel S, Weiller C. Functional neuroimaging: functional magnetic resonance imaging, positron emission tomography, and single-photon emission computed ...

Technological Advances in the Study of Reading: An Introduction.

ERIC Educational Resources Information Center

Henk, William A.

1991-01-01

Describes the purpose and functional operation of new computer-driven technologies such as computerized axial tomography, positron emissions transaxial tomography, regional cerebral blood flow monitoring, magnetic resonance imaging, and brain electrical activity mapping. Outlines their current contribution to the knowledge base. Speculates on the…

Trails on 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Leading to Diagnosis of Testicular Adrenal Rest Tumor.

PubMed

Kashyap, Raghava

2018-01-01

Testicular adrenal rest tumors (TARTs) are secondary to hypertrophy of adrenal rest cells in the rete testis in settings of hypersecretion of androgens. We present a case of congenital adrenal hyperplasia with TART with clues to the diagnosis on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT). To the best of our knowledge, this is the first reported case on the role of 18 F-FDG PET/CT in TART.

Pleuroperitoneal Mesothelioma: A Rare Entity on 18F-FDG PET/CT

PubMed Central

Sahoo, Manas Kumar; Mukherjee, Anirban; Girish; Parida, Kumar; Agarwal, Krishan Kant; Bal, Chandrasekhar; Tripathi, Madhavi; Das, Chandan Jyoti; Shamim, Shamim Ahmed

2017-01-01

Pleuroperitoneal mesothelioma is an extremely rare entity. Only few cases are reported worldwide. We hereby represent a case of pleural mesothelioma referred for F-18-Fluorodeoxyglucose positron emission tomography/computed tomography for response evaluation. Diffuse F-18-Fluorodeoxyglucose avid peritoneal and omental thickening noted which subsequently turned out to be mesothelial involvement on peritoneal biopsy. This case demonstrates the role of F-18-Fluorodeoxyglucose positron emission tomography/computed tomography in detecting other sites of involvement in case of malignant mesothelioma. PMID:28242997

Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Disseminated Cryptococcosis.

PubMed

Tripathy, Sarthak; Parida, Girish Kumar; Roy, Shambo Guha; Singhal, Abhinav; Mallick, Saumya Ranjan; Tripathi, Madhavi; Shamim, Shamim Ahmed

2017-01-01

Disseminated cryptococcosis without pulmonary involvement is a very rare phenomenon. Patterns of organ involvement in cryptococcosis resemble various other infective conditions as well as malignant conditions on fluorodeoxyglucose positron emission tomography-computed tomography. We present a case of a 43-year-old male patient who had disseminated cryptococcosis. The rarity of the case being noninvolvement of lungs and meninges and resembling more like lymphoma due to the diffuse involvement of the lymph nodes on both sides of the diaphragm.

Combined single photon emission computerized tomography and conventional computerized tomography: Clinical value for the shoulder surgeons?

PubMed Central

Hirschmann, Michael T.; Schmid, Rahel; Dhawan, Ranju; Skarvan, Jiri; Rasch, Helmut; Friederich, Niklaus F.; Emery, Roger

2011-01-01

With the cases described, we strive to introduce single photon emission computerized tomography in combination with conventional computer tomography (SPECT/CT) to shoulder surgeons, illustrate the possible clinical value it may offer as new diagnostic radiologic modality, and discuss its limitations. SPECT/CT may facilitate the establishment of diagnosis, process of decision making, and further treatment for complex shoulder pathologies. Some of these advantages were highlighted in cases that are frequently seen in most shoulder clinics. PMID:22058640

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. Published by Elsevier Inc.

Physically corrected forward operators for induced emission tomography: a simulation study

NASA Astrophysics Data System (ADS)

Viganò, Nicola Roberto; Solé, Vicente Armando

2018-03-01

X-ray emission tomography techniques over non-radioactive materials allow one to investigate different and important aspects of the matter that are usually not addressable with the standard x-ray transmission tomography, such as density, chemical composition and crystallographic information. However, the quantitative reconstruction of these investigated properties is hindered by additional problems, including the self-attenuation of the emitted radiation. Work has been done in the past, especially concerning x-ray fluorescence tomography, but this has always focused on solving very specific problems. The novelty of this work resides in addressing the problem of induced emission tomography from a much wider perspective, introducing a unified discrete representation that can be used to modify existing algorithms to reconstruct the data of the different types of experiments. The direct outcome is a clear and easy mathematical description of the implementation details of such algorithms, despite small differences in geometry and other practical aspects, but also the possibility to express the reconstruction as a minimization problem, allowing the use of variational methods, and a more flexible modeling of the noise involved in the detection process. In addition, we look at the results of a few selected simulated data reconstructions that describe the effect of physical corrections like the self-attenuation, and the response to noise of the adapted reconstruction algorithms.

Addiction Studies with Positron Emission Tomography

ScienceCinema

Joanna Fowler

2017-12-09

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

Addiction Studies with Positron Emission Tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joanna Fowler

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

Striatal dopamine in Parkinson disease: A meta-analysis of imaging studies.

PubMed

Kaasinen, Valtteri; Vahlberg, Tero

2017-12-01

A meta-analysis of 142 positron emission tomography and single photon emission computed tomography studies that have investigated striatal presynaptic dopamine function in Parkinson disease (PD) was performed. Subregional estimates of striatal dopamine metabolism are presented. The aromatic L-amino-acid decarboxylase (AADC) defect appears to be consistently smaller than the dopamine transporter and vesicular monoamine transporter 2 defects, suggesting upregulation of AADC function in PD. The correlation between disease severity and dopamine loss appears linear, but the majority of longitudinal studies point to a negative exponential progression pattern of dopamine loss in PD. Ann Neurol 2017;82:873-882. © 2017 American Neurological Association.

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

2017-12-01

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.

Systematic Review on the Accuracy of Positron Emission Tomography/Computed Tomography and Positron Emission Tomography/Magnetic Resonance Imaging in the Management of Ovarian Cancer: Is Functional Information Really Needed?

PubMed Central

Suppiah, Subapriya; Chang, Wing Liong; Hassan, Hasyma Abu; Kaewput, Chalermrat; Asri, Andi Anggeriana Andi; Saad, Fathinul Fikri Ahmad; Nordin, Abdul Jalil; Vinjamuri, Sobhan

2017-01-01

Ovarian cancer (OC) often presents at an advanced stage with frequent relapses despite optimal treatment; thus, accurate staging and restaging are required for improving treatment outcomes and prognostication. Conventionally, staging of OC is performed using contrast-enhanced computed tomography (CT). Nevertheless, recent advances in the field of hybrid imaging have made positron emission tomography/CT (PET/CT) and PET/magnetic resonance imaging (PET/MRI) as emerging potential noninvasive imaging tools for improved management of OC. Several studies have championed the role of PET/CT for the detection of recurrence and prognostication of OC. We provide a systematic review and meta-analysis of the latest publications regarding the role of molecular imaging in the management of OC. We retrieved 57 original research articles with one article having overlap in both diagnosis and staging; 10 articles (734 patients) regarding the role of PET/CT in diagnosis of OC; 12 articles (604 patients) regarding staging of OC; 22 studies (1429 patients) for detection of recurrence; and 13 articles for prognostication and assessment of treatment response. We calculated pooled sensitivity and specificity of PET/CT performance in various aspects of imaging of OC. We also discussed the emerging role of PET/MRI in the management of OC. We aim to give the readers and objective overview on the role of molecular imaging in the management of OC. PMID:28670174

SIMULATION STUDY FOR GASEOUS FLUXES FROM AN AREA SOURCE USING COMPUTED TOMOGRAPHY AND OPTICAL REMOTE SENSING

EPA Science Inventory

The paper presents a new approach to quantifying emissions from fugitive gaseous air pollution sources. Computed tomography (CT) and path-integrated optical remote sensing (PI-ORS) concentration data are combined in a new field beam geometry. Path-integrated concentrations are ...

Adult onset Niemann-Pick type C disease: A clinical, neuroimaging and molecular genetic study.

PubMed

Battisti, Carla; Tarugi, Patrizla; Dotti, Maria Teresa; De Stefano, Nicola; Vattimo, Angelo; Chierichetti, Francesea; Calandra, Sebastiano; Federico, Antonio

2003-11-01

We report on a patient with adult-onset Niemann-Pick type C (NPC) disease, carrying the mutations P1007 and I1061T in the NPC1 gene, presenting with marked psychiatric changes followed by dystonia and cognitive impairment. Filipin staining, single photon emission computed tomography perfusional, positron emission tomography metabolic, conventional magnetic resonance imaging, and magnetic resonance spectroscopy findings suggested a pathophysiological correlation with phenotype expression. This case expands the clinical and genetic spectrum of the rare adult-onset NPC disease phenotype.

Positron emission tomography assessment of effects of benzodiazepines on regional glucose metabolic rate in patients with anxiety disorder

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buchsbaum, M.S.; Wu, J.; Haier, R.

1987-06-22

Patients with generalized anxiety disorder (n = 18) entered a 21-day, double-blind, placebo-controlled random assignment trial of clorazepate. Positron emission tomography with YF-deoxyglucose was carried out before and after treatment. Decreases in glucose metabolic rate in visual cortex and relative increases in the basal ganglia and thalamus were found. A correlation between regional changes in metabolic rate and regional benzodiazepine receptor binding density from other human autopsy studies was observed; brain regions highest in receptor density showed the greatest decrease in rate.

The Evolution of Neuroimaging Research and Developmental Language Disorders.

ERIC Educational Resources Information Center

Lane, Angela B.; Foundas, Anne L.; Leonard, Christiana M.

2001-01-01

This article reviews current neuroimaging literature, including computer tomography, positron emission tomography, single photon emission spectroscopy, and magnetic resonance imaging, on individuals with developmental language disorders. The review suggests a complicated relationship between cortical morphometry and language development that is…

Hybrid Gama Emission Tomography (HGET): FY16 Annual Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Erin A.; Smith, Leon E.; Wittman, Richard S.

2017-02-01

Current International Atomic Energy Agency (IAEA) methodologies for the verification of fresh low-enriched uranium (LEU) and mixed oxide (MOX) fuel assemblies are volume-averaging methods that lack sensitivity to individual pins. Further, as fresh fuel assemblies become more and more complex (e.g., heavy gadolinium loading, high degrees of axial and radial variation in fissile concentration), the accuracy of current IAEA instruments degrades and measurement time increases. Particularly in light of the fact that no special tooling is required to remove individual pins from modern fuel assemblies, the IAEA needs new capabilities for the verification of unirradiated (i.e., fresh LEU and MOX)more » assemblies to ensure that fissile material has not been diverted. Passive gamma emission tomography has demonstrated potential to provide pin-level verification of spent fuel, but gamma-ray emission rates from unirradiated fuel emissions are significantly lower, precluding purely passive tomography methods. The work presented here introduces the concept of Hybrid Gamma Emission Tomography (HGET) for verification of unirradiated fuels, in which a neutron source is used to actively interrogate the fuel assembly and the resulting gamma-ray emissions are imaged using tomographic methods to provide pin-level verification of fissile material concentration.« less

Review of cardiovascular imaging in The Journal of Nuclear Cardiology in 2014: Part 1 of 2: Positron emission tomography, computed tomography, and neuronal imaging.

PubMed

AlJaroudi, Wael A; Hage, Fadi G

2015-06-01

The year 2014 has been an exciting year for the cardiovascular imaging community with significant advances in the realm of nuclear and multimodality cardiac imaging. In this new feature of the Journal of Nuclear Cardiology, we will summarize some of the breakthroughs that were published in the Journal in 2014 in 2 sister articles. This first article will concentrate on publications dealing with cardiac positron emission tomography (PET), computed tomography (CT), and neuronal imaging.

PET imaging for receptor occupancy: meditations on calculation and simplification.

PubMed

Zhang, Yumin; Fox, Gerard B

2012-03-01

This invited mini-review briefly summarizes procedures and challenges of measuring receptor occupancy with positron emission tomography. Instead of describing the detailed analytic procedures of in vivo ligand-receptor imaging, the authors provide a pragmatic approach, along with personal perspectives, for conducting positron emission tomography imaging for receptor occupancy, and systematically elucidate the mathematics of receptor occupancy calculations in practical ways that can be understood with elementary algebra. The authors also share insights regarding positron emission tomography imaging for receptor occupancy to facilitate applications for the development of drugs targeting receptors in the central nervous system.

PET imaging for receptor occupancy: meditations on calculation and simplification

PubMed Central

Zhang, Yumin; Fox, Gerard B.

2012-01-01

This invited mini-review briefly summarizes procedures and challenges of measuring receptor occupancy with positron emission tomography. Instead of describing the detailed analytic procedures of in vivo ligand-receptor imaging, the authors provide a pragmatic approach, along with personal perspectives, for conducting positron emission tomography imaging for receptor occupancy, and systematically elucidate the mathematics of receptor occupancy calculations in practical ways that can be understood with elementary algebra. The authors also share insights regarding positron emission tomography imaging for receptor occupancy to facilitate applications for the development of drugs targeting receptors in the central nervous system. PMID:23554733

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campbell, Janice M.; Department of Radiation Oncology, Wayne State University, Detroit, MI; Wong, C. Oliver

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 standardizedmore » 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.« less

Design of a portable optical emission tomography system for microwave induced compact plasma for visible to near-infrared emission lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rathore, Kavita, E-mail: kavira@iitk.ac.in, E-mail: pmunshi@iitk.ac.in, E-mail: sudeepb@iitk.ac.in; Munshi, Prabhat, E-mail: kavira@iitk.ac.in, E-mail: pmunshi@iitk.ac.in, E-mail: sudeepb@iitk.ac.in; Bhattacharjee, Sudeep, E-mail: kavira@iitk.ac.in, E-mail: pmunshi@iitk.ac.in, E-mail: sudeepb@iitk.ac.in

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 actualmore » 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.« less

Positron Emission Tomography Molecular Imaging in Late-Life Depression

PubMed Central

Hirao, Kentaro; Smith, Gwenn S.

2017-01-01

Molecular imaging represents a bridge between basic and clinical neuroscience observations and provides many opportunities for translation and identifying mechanisms that may inform prevention and intervention strategies in late-life depression (LLD). Substantial advances in instrumentation and radiotracer chemistry have resulted in improved sensitivity and spatial resolution and the ability to study in vivo an increasing number of neurotransmitters, neuromodulators, and, importantly, neuropathological processes. Molecular brain imaging studies in LLD will be reviewed, with a primary focus on positron emission tomography. Future directions for the field of molecular imaging in LLD will be discussed, including integrating molecular imaging with genetic, neuropsychiatric, and cognitive outcomes and multimodality neuroimaging. PMID:24394152

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…

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.

PET/CT in paediatric malignancies - An update

PubMed Central

Padma, Subramanyam; Sundaram, Palaniswamy Shanmuga; Tewari, Anshu

2016-01-01

18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a well-established imaging modality in adult oncological practice. Its role in childhood malignancies needs to be discussed as paediatric malignancies differ from adults in tumor subtypes and they have different tumor biology and FDG uptake patterns. This is also compounded by smaller body mass, dosimetric restrictions, and physiological factors that can affect the FDG uptake. It calls for careful planning of the PET study, preparing the child, the parents, and expertise of nuclear physicians in reporting pediatric positron emission tomography/computed tomography (PET/CT) studies. In a broad perspective, FDG-PET/CT has been used in staging, assessment of therapy response, identifying metastases and as a follow-up tool in a wide variety of pediatric malignancies. This review outlines the role of PET/CT in childhood malignancies other than hematological malignancies such as lymphoma and leukemia. PMID:27688605

Image Guided Biodistribution and Pharmacokinetic Studies of Theranostics

PubMed Central

Ding, Hong; Wu, Fang

2012-01-01

Image guided technique is playing an increasingly important role in the investigation of the biodistribution and pharmacokinetics of drugs or drug delivery systems in various diseases, especially cancers. Besides anatomical imaging modalities such as computed tomography (CT), magnetic resonance imaging (MRI), molecular imaging strategy including optical imaging, positron emission tomography (PET) and single-photon emission computed tomography (SPECT) will facilitate the localization and quantization of radioisotope or optical probe labeled nanoparticle delivery systems in the category of theranostics. The quantitative measurement of the bio-distribution and pharmacokinetics of theranostics in the fields of new drug/probe development, diagnosis and treatment process monitoring as well as tracking the brain-blood-barrier (BBB) breaking through by high sensitive imaging method, and the applications of the representative imaging modalities are summarized in this review. PMID:23227121

[Positron emission tomography and the Hungarian PET program].

PubMed

Trón, Lajos

2002-05-26

After a short introduction detailing the most basic features of the positron emission tomography (PET) the history of the preparation for the start of the Hungarian PET program is reviewed along with the results of the eight years activity of the Debrecen PET Centre.

Single photon emission computed tomography and positron emission tomography imaging of multi-drug resistant P-glycoprotein--monitoring a transport activity important in cancer, blood-brain barrier function and Alzheimer's disease.

PubMed

Piwnica-Worms, David; Kesarwala, Aparna H; Pichler, Andrea; Prior, Julie L; Sharma, Vijay

2006-11-01

Overexpression of multi-drug resistant P-glycoprotein (Pgp) remains an important barrier to successful chemotherapy in cancer patients and impacts the pharmacokinetics of many important drugs. Pgp is also expressed on the luminal surface of brain capillary endothelial cells wherein Pgp functionally comprises a major component of the blood-brain barrier by limiting central nervous system penetration of various therapeutic agents. In addition, Pgp in brain capillary endothelial cells removes amyloid-beta from the brain. Several single photon emission computed tomography and positron emission tomography radiopharmaceutical have been shown to be transported by Pgp, thereby enabling the noninvasive interrogation of Pgp-mediated transport activity in vivo. Therefore, molecular imaging of Pgp activity may enable noninvasive dynamic monitoring of multi-drug resistance in cancer, guide therapeutic choices in cancer chemotherapy, and identify transporter deficiencies of the blood-brain barrier in Alzheimer's disease.

Reduced ventilation-perfusion (V/Q) mismatch following endobronchial valve insertion demonstrated by Gallium-68 V/Q photon emission tomography/computed tomography.

PubMed

Leong, Paul; Le Roux, Pierre-Yves; Callahan, Jason; Siva, Shankar; Hofman, Michael S; Steinfort, Daniel P

2017-09-01

Endobronchial valves (EBVs) are increasingly deployed in the management of severe emphysema. Initial studies focussed on volume reduction as the mechanism, with subsequent improvement in forced expiratory volume in 1 s (FEV 1 ). More recent studies have emphasized importance of perfusion on predicting outcomes, though findings have been inconsistent. Gallium-68 ventilation-perfusion (V/Q) photon emission tomography (PET)/computed tomography (CT) is a novel imaging modality with advantages in spatial resolution, quantitation, and speed over conventional V/Q scintigraphy. We report a pilot case in which V/Q-PET/CT demonstrated discordant findings compared with quantitative CT analysis, and directed left lower lobe EBV placement. The patient experienced a significant improvement in 6-min walk distance (6MWD) without change in spirometry. Post-EBV V/Q-PET/CT demonstrated a marked decrease in unmatched (detrimental) V/Q areas and improvement in overall V/Q matching on post-EBV V/Q-PET/CT. These preliminary novel findings suggest that EBVs improve V/Q matching and may explain the observed functional improvements.

The role of fluorine-18-fluorodeoxyglucose positron emission tomography in aggressive histological subtypes of thyroid cancer: an overview.

PubMed

Treglia, Giorgio; Annunziata, Salvatore; Muoio, Barbara; Salvatori, Massimo; Ceriani, Luca; Giovanella, Luca

2013-01-01

Aggressive histological subtypes of thyroid cancer are rare and have a poor prognosis. The most important aggressive subtypes of thyroid cancer are Hürthle cell carcinoma (HCTC) and anaplastic and poorly differentiated carcinoma (ATC and PDTC). The American Thyroid Association recently published guidelines for the management of patients with ATC, but no specific guidelines have been done about HCTC. We performed an overview of the literature about the role of Fluorine-18-Fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography (FDG-PET or PET/CT) in aggressive histological subtypes of thyroid cancer. Only few original studies about the role of FDG-PET or PET/CT in HCTC, PDTC, and ATC have been published in the literature. FDG-PET or PET/CT seems to be useful in staging or followup of invasive and metastatic HCTC. FDG-PET or PET/CT should be used in patients with ATC in initial staging and in the followup after surgery to evaluate metastatic disease. Some authors suggest the use of FDG-PET/CT in staging of PDTC, but more studies are needed to define the diagnostic use of FDG-PET/CT in this setting. Limited experience suggests the usefulness of FDG-PET or PET/CT in patients with more aggressive histological subtypes of DTC. However, DTC presenting as radioiodine refractory and FDG-PET positive should be considered aggressive tumours with poor prognosis.

Diagnostic dilemma of degenerative joint disease, chronic avascular necrosis or metastasis in planar Tc-99m-methylene diphosphonate planar skeletal scintigraphy excluded by single positron emission computed tomography/computed tomography.

PubMed

Jain, Tarun Kumar; Phulsunga, Rohit Kumar; Basher, Rajender Kumar; Kumar, Narendra; Bhattacharya, Anish; Mittal, Bhagwant Rai

2015-01-01

We present a 71-year-old male patient subjected to skeletal scintigraphy for metastasis work up of prostate cancer. Whole body planar images revealed a solitary focal tracer uptake in left femoral head mimicking as solitary metastatic focus. Single positron emission computed tomography/computed tomography images localized this increased tracer uptake to the subchondral cysts with minimal sclerosis in left femur head with no decrease in size of femur head and was reported as (degenerative joint disease).

Diagnostic dilemma of degenerative joint disease, chronic avascular necrosis or metastasis in planar Tc-99m-methylene diphosphonate planar skeletal scintigraphy excluded by single positron emission computed tomography/computed tomography

PubMed Central

Jain, Tarun Kumar; Phulsunga, Rohit Kumar; Basher, Rajender Kumar; Kumar, Narendra; Bhattacharya, Anish; Mittal, Bhagwant Rai

2015-01-01

We present a 71-year-old male patient subjected to skeletal scintigraphy for metastasis work up of prostate cancer. Whole body planar images revealed a solitary focal tracer uptake in left femoral head mimicking as solitary metastatic focus. Single positron emission computed tomography/computed tomography images localized this increased tracer uptake to the subchondral cysts with minimal sclerosis in left femur head with no decrease in size of femur head and was reported as (degenerative joint disease). PMID:26170582

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... analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component...

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... analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component...

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... analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component...

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... analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component...

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... analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component...

Accuracy and Precision of Radioactivity Quantification in Nuclear Medicine Images

PubMed Central

Frey, Eric C.; Humm, John L.; Ljungberg, Michael

2012-01-01

The ability to reliably quantify activity in nuclear medicine has a number of increasingly important applications. Dosimetry for targeted therapy treatment planning or for approval of new imaging agents requires accurate estimation of the activity in organs, tumors, or voxels at several imaging time points. Another important application is the use of quantitative metrics derived from images, such as the standard uptake value commonly used in positron emission tomography (PET), to diagnose and follow treatment of tumors. These measures require quantification of organ or tumor activities in nuclear medicine images. However, there are a number of physical, patient, and technical factors that limit the quantitative reliability of nuclear medicine images. There have been a large number of improvements in instrumentation, including the development of hybrid single-photon emission computed tomography/computed tomography and PET/computed tomography systems, and reconstruction methods, including the use of statistical iterative reconstruction methods, which have substantially improved the ability to obtain reliable quantitative information from planar, single-photon emission computed tomography, and PET images. PMID:22475429

Evaluative studies in nuclear medicine research. Emission-computed tomography assessment. Progress report 1 January-15 August 1981

DOE Office of Scientific and Technical Information (OSTI.GOV)

Potchen, E.J.

Questions regarding what imaging performance goals need to be met to produce effective biomedical research using positron emission computer tomography, how near those performance goals are to being realized by imaging systems, and the dependence of currently-unachieved performance goals on design and operational factors have been addressed in the past year, along with refinement of economic estimates for the capital and operating costs of a PECT research facility. The two primary sources of information have been solicitations of expert opinion and review of current literature. (ACR)

Positron emission tomography/computed tomography imaging and rheumatoid arthritis.

PubMed

Wang, Shi-Cun; Xie, Qiang; Lv, Wei-Fu

2014-03-01

Rheumatoid arthritis (RA) is a phenotypically heterogeneous, chronic, destructive inflammatory disease of the synovial joints. A number of imaging tools are currently available for evaluation of inflammatory conditions. By targeting the upgraded glucose uptake of infiltrating granulocytes and tissue macrophages, positron emission tomography/computed tomography with fluorine-18 fluorodeoxyglucose ((18) F-FDG PET/CT) is available to delineate inflammation with high sensitivity. Recently, several studies have indicated that FDG uptake in affected joints reflects the disease activity of RA. In addition, usage of FDG PET for the sensitive detection and monitoring of the response to treatment has been reported. Combined FDG PET/CT enables the detailed assessment of disease in large joints throughout the whole body. These unique capabilities of FDG PET/CT imaging are also able to detect RA-complicated diseases. Therefore, PET/CT has become an excellent ancillary tool to assess disease activity and prognosis in RA. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

Clinical impact of (11)C-Pittsburgh compound-B positron emission tomography carried out in addition to magnetic resonance imaging and single-photon emission computed tomography on the diagnosis of Alzheimer's disease in patients with dementia and mild cognitive impairment.

PubMed

Omachi, Yoshie; Ito, Kimiteru; Arima, Kunimasa; Matsuda, Hiroshi; Nakata, Yasuhiro; Sakata, Masuhiro; Sato, Noriko; Nakagome, Kazuyuki; Motohashi, Nobutaka

2015-12-01

The purpose of this study was to evaluate the clinical impact of addition of [(11)C]Pittsburgh compound-B positron emission tomography ((11)C-PiB PET) on routine clinical diagnosis of Alzheimer's disease (AD) dementia and mild cognitive impairment (MCI), and to assess diagnostic agreement between clinical criteria and research criteria of the National Institute on Aging-Alzheimer's Association. The diagnosis in 85 patients was made according to clinical criteria. Imaging examinations, including both magnetic resonance imaging and single-photon emission computed tomography/computed tomography to identify neuronal injury (NI), and (11)C-PiB PET to identify amyloid were performed, and all subjects were re-categorized according to the research criteria. Among 40 patients with probable AD dementia (ProAD), 37 were NI-positive, 29 were (11)C-PiB-positive, and 27 who were both NI- and (11C-PiB-positive were categorized as having 'ProAD dementia with a high level of evidence of the AD pathophysiological process'. Among 20 patients with possible AD dementia (PosAD), 17 were NI-positive, and six who were both NI- and (11)C-PiB-positive were categorized as having 'PosAD with evidence of the AD pathophysiological process'. Among 25 patients with MCI, 18 were NI-positive, 13 were (11)C-PiB-positive, and 10 who were both NI- and (11)C-PiB-positive were categorized as having 'MCI due to AD-high likelihood'. Diagnostic concordance between clinical criteria and research criteria may not be high in this study. (11)C-PiB PET may be of value in making the diagnosis of dementia and MCI in cases with high diagnostic uncertainty. © 2015 The Authors. Psychiatry and Clinical Neurosciences © 2015 Japanese Society of Psychiatry and Neurology.

Studies of the brain cannabinoid system using positron emission tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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 ofmore » cocaine binding sites, to demonstrate the kind of investigations that will be possible when a cannabinoid receptor PET radioligand becomes available.« less

Positron Emission Tomography in Cochlear Implant and Auditory Brainstem Implant Recipients.

ERIC Educational Resources Information Center

Miyamoto, Richard T.; Wong, Donald

2001-01-01

Positron emission tomography imaging was used to evaluate the brain's response to auditory stimulation, including speech, in deaf adults (five with cochlear implants and one with an auditory brainstem implant). Functional speech processing was associated with activation in areas classically associated with speech processing. (Contains five…

77 FR 8262 - Draft Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-14

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-D-0081] Draft Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug...

Single photon emission computed tomography in motor neuron disease with dementia.

PubMed

Sawada, H; Udaka, F; Kishi, Y; Seriu, N; Mezaki, T; Kameyama, M; Honda, M; Tomonobu, M

1988-01-01

Single photon emission computed tomography with [123 I] isopropylamphetamine was carried out on a patient with motor neuron disease with dementia. [123 I] uptake was decreased in the frontal lobes. This would reflect the histopathological findings such as neuronal loss and gliosis in the frontal lobes.

Anti-leucine rich glioma inactivated 1 protein and anti-N-methyl-D-aspartate receptor encephalitis show distinct patterns of brain glucose metabolism in 18F-fluoro-2-deoxy-d-glucose positron emission tomography

PubMed Central

2014-01-01

Background Pathogenic autoantibodies targeting the recently identified leucine rich glioma inactivated 1 protein and the subunit 1 of the N-methyl-D-aspartate receptor induce autoimmune encephalitis. A comparison of brain metabolic patterns in 18F-fluoro-2-deoxy-d-glucose positron emission tomography of anti-leucine rich glioma inactivated 1 protein and anti-N-methyl-D-aspartate receptor encephalitis patients has not been performed yet and shall be helpful in differentiating these two most common forms of autoimmune encephalitis. Methods The brain 18F-fluoro-2-deoxy-d-glucose uptake from whole-body positron emission tomography of six anti-N-methyl-D-aspartate receptor encephalitis patients and four patients with anti-leucine rich glioma inactivated 1 protein encephalitis admitted to Hannover Medical School between 2008 and 2012 was retrospectively analyzed and compared to matched controls. Results Group analysis of anti-N-methyl-D-aspartate encephalitis patients demonstrated regionally limited hypermetabolism in frontotemporal areas contrasting an extensive hypometabolism in parietal lobes, whereas the anti-leucine rich glioma inactivated 1 protein syndrome was characterized by hypermetabolism in cerebellar, basal ganglia, occipital and precentral areas and minor frontomesial hypometabolism. Conclusions This retrospective 18F-fluoro-2-deoxy-d-glucose positron emission tomography study provides novel evidence for distinct brain metabolic patterns in patients with anti-leucine rich glioma inactivated 1 protein and anti-N-methyl-D-aspartate receptor encephalitis. PMID:24950993

Greater left cerebral hemispheric metabolism in bulimia assessed by positron emission tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, J.C.; Hagman, J.; Buchsbaum, M.S.

1990-03-01

Eight women with bulimia and eight age- and sex-matched normal control subjects were studied with positron emission tomography using (18F)-fluorodeoxyglucose (FDG) as a tracer of brain metabolic rate. Subjects performed a visual vigilance task during FDG uptake. In control subjects, the metabolic rate was higher in the right hemisphere than in the left, but patients with bulimia did not have this normal asymmetry. Lower metabolic rates in the basal ganglia, found in studies of depressed subjects, and higher rates in the basal ganglia, reported in a study of anorexia nervosa, were not found. This is consistent with the suggestion thatmore » bulimia is a diagnostic grouping distinct from these disorders.« less

Volume-Based Parameters of {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Improve Disease Recurrence Prediction in Postmastectomy Breast Cancer Patients With 1 to 3 Positive Axillary Lymph Nodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakajima, Naomi, E-mail: haruhi0321@gmail.com; Department of Radiology, Ehime University, Ehime; Kataoka, Masaaki

Purpose: To determine whether volume-based parameters on pretreatment {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography in breast cancer patients treated with mastectomy without adjuvant radiation therapy are predictive of recurrence. Methods and Materials: We retrospectively analyzed 93 patients with 1 to 3 positive axillary nodes after surgery, who were studied with {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography for initial staging. We evaluated the relationship between positron emission tomography parameters, including the maximum standardized uptake value, metabolic tumor volume (MTV), and total lesion glycolysis (TLG), and clinical outcomes. Results: The median follow-up duration was 45 months. Recurrence was observed in 11 patients.more » Metabolic tumor volume and TLG were significantly related to tumor size, number of involved nodes, nodal ratio, nuclear grade, estrogen receptor (ER) status, and triple negativity (TN) (all P values were <.05). In receiver operating characteristic curve analysis, MTV and TLG showed better predictive performance than tumor size, ER status, or TN (area under the curve: 0.85, 0.86, 0.79, 0.74, and 0.74, respectively). On multivariate analysis, MTV was an independent prognostic factor of locoregional recurrence-free survival (hazard ratio 34.42, 95% confidence interval 3.94-882.71, P=.0008) and disease-free survival (DFS) (hazard ratio 13.92, 95% confidence interval 2.65-103.78, P=.0018). The 3-year DFS rate was 93.8% for the lower MTV group (<53.1; n=85) and 25.0% for the higher MTV group (≥53.1; n=8; P<.0001, log–rank test). The 3-year DFS rate for patients with both ER-positive status and MTV <53.1 was 98.2%; and for those with ER-negative status and MTV ≥53.1 it was 25.0% (P<.0001). Conclusions: Volume-based parameters improve recurrence prediction in postmastectomy breast cancer patients with 1 to 3 positive nodes. The addition of MTV to ER status or TN has potential benefits to identify a subgroup at higher risk for recurrence.« less

18-Fluorodeoxy-Glucose Positron Emission Tomography- Computed Tomography (18-FDG-PET/CT) for Gross Tumor Volume (GTV) Delineation in Gastric Cancer Radiotherapy

PubMed

Dębiec, Kinga; Wydmański, Jerzy; Gorczewska, Izabela; Leszczyńska, Paulina; Gorczewski, Kamil; Leszczyński, Wojciech; d’Amico, Andrea; Kalemba, Michał

2017-11-26

Purpose: Evaluation of the 18-fluorodeoxy-glucose positron emission tomography-computed tomography (18-FDGPET/ CT) for gross tumor volume (GTV) delineation in gastric cancer patients undergoing radiotherapy. Methods: In this study, 29 gastric cancer patients (17 unresectable and 7 inoperable) were initially enrolled for radical chemoradiotherapy (45Gy/25 fractions + chemotherapy based on 5 fluorouracil) or radiotherapy alone (45Gy/25 fractions) with planning based on the 18-FDG-PET/CT images. Five patients were excluded due to excess blood glucose levels (1), false-negative positron emission tomography (1) and distant metastases revealed by 18-FDG-PET/CT (3). The analysis involved measurement of metabolic tumor volumes (MTVs) performed on PET/CT workstations. Different threshold levels of the standardized uptake value (SUV) and liver uptake were set to obtain MTVs. Secondly, GTVPET values were derived manually using the positron emission tomography (PET) dataset blinded to the computed tomography (CT) data. Subsequently, GTVCT values were delineated using a radiotherapy planning system based on the CT scans blinded to the PET data. The referenced GTVCT values were correlated with the GTVPET and were compared with a conformality index (CI). Results: The mean CI was 0.52 (range, 0.12-0.85). In 13/24 patients (54%), the GTVPET was larger than GTVCT, and in the remainder, GTVPET was smaller. Moreover, the cranio-caudal diameter of GTVPET in 16 cases (64%) was larger than that of GTVCT, smaller in 7 cases (29%), and unchanged in one case. Manual PET delineation (GTVPET) achieved the best correlation with GTVCT (Pearson correlation = 0.76, p <0.0001). Among the analyzed MTVs, a statistically significant correlation with GTVCT was revealed for MTV10%SUVmax (r = 0.63; p = 0.0014), MTVliv (r = 0.60; p = 0.0021), MTVSUV2.5 (r = 0.54; p = 0.0063); MTV20%SUVmax (r = 0.44; p = 0.0344); MTV30%SUVmax (r = 0.44; p = 0.0373). Conclusion: 18-FDG-PET/CT in gastric cancer radiotherapy planning may affect the GTV delineation. https://www.ncbi.nlm.nih.gov/pubmed/management

Technical Considerations on Scanning and Image Analysis for Amyloid PET in Dementia.

PubMed

Akamatsu, Go; Ohnishi, Akihito; Aita, Kazuki; Ikari, Yasuhiko; Yamamoto, Yasuji; Senda, Michio

2017-01-01

Brain imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and positron emission tomography (PET), can provide essential and objective information for the early and differential diagnosis of dementia. Amyloid PET is especially useful to evaluate the amyloid-β pathological process as a biomarker of Alzheimer's disease. This article reviews critical points about technical considerations on the scanning and image analysis methods for amyloid PET. Each amyloid PET agent has its own proper administration instructions and recommended uptake time, scan duration, and the method of image display and interpretation. In addition, we have introduced general scanning information, including subject positioning, reconstruction parameters, and quantitative and statistical image analysis. We believe that this article could make amyloid PET a more reliable tool in clinical study and practice.

Dual-modality imaging

NASA Astrophysics Data System (ADS)

Hasegawa, Bruce; Tang, H. Roger; Da Silva, Angela J.; Wong, Kenneth H.; Iwata, Koji; Wu, Max C.

2001-09-01

In comparison to conventional medical imaging techniques, dual-modality imaging offers the advantage of correlating anatomical information from X-ray computed tomography (CT) with functional measurements from single-photon emission computed tomography (SPECT) or with positron emission tomography (PET). The combined X-ray/radionuclide images from dual-modality imaging can help the clinician to differentiate disease from normal uptake of radiopharmaceuticals, and to improve diagnosis and staging of disease. In addition, phantom and animal studies have demonstrated that a priori structural information from CT can be used to improve quantification of tissue uptake and organ function by correcting the radionuclide data for errors due to photon attenuation, partial volume effects, scatter radiation, and other physical effects. Dual-modality imaging therefore is emerging as a method of improving the visual quality and the quantitative accuracy of radionuclide imaging for diagnosis of patients with cancer and heart disease.

Imaging and modeling of flow in porous media using clinical nuclear emission tomography systems and computational fluid dynamics

NASA Astrophysics Data System (ADS)

Boutchko, Rostyslav; Rayz, Vitaliy L.; Vandehey, Nicholas T.; O'Neil, James P.; Budinger, Thomas F.; Nico, Peter S.; Druhan, Jennifer L.; Saloner, David A.; Gullberg, Grant T.; Moses, William W.

2012-01-01

This paper presents experimental and modeling aspects of applying nuclear emission tomography to study fluid flow in laboratory packed porous media columns of the type frequently used in geophysics, geochemistry and hydrology research. Positron emission tomography (PET) and single photon emission computed tomography (SPECT) are used as non-invasive tools to obtain dynamic 3D images of radioactive tracer concentrations. Dynamic sequences obtained using 18F-FDG PET are used to trace flow through a 5 cm diameter × 20 cm tall sand packed column with and without an impermeable obstacle. In addition, a custom-made rotating column setup placed in a clinical two-headed SPECT camera is used to image 99mTc-DTPA tracer propagation in a through-flowing column (10 cm diameter × 30 cm tall) packed with recovered aquifer sediments. A computational fluid dynamics software package FLUENT is used to model the observed flow dynamics. Tracer distributions obtained in the simulations in the smaller column uniformly packed with sand and in the column with an obstacle are remarkably similar to the reconstructed images in the PET experiments. SPECT results demonstrate strongly non-uniform flow patterns for the larger column slurry-packed with sub-surface sediment and slow upward flow. In the numerical simulation of the SPECT study, two symmetric channels with increased permeability are prescribed along the column walls, which result in the emergence of two well-defined preferential flow paths. Methods and results of this work provide new opportunities in hydrologic and biogeochemical research. The primary target application for developed technologies is non-destructive, non-perturbing, quantitative imaging of flow dynamics within laboratory scale porous media systems.

Imaging and modeling of flow in porous media using clinical nuclear emission tomography systems and computational fluid dynamics.

PubMed

Boutchko, Rostyslav; Rayz, Vitaliy L; Vandehey, Nicholas T; O'Neil, James P; Budinger, Thomas F; Nico, Peter S; Druhan, Jennifer L; Saloner, David A; Gullberg, Grant T; Moses, William W

2012-01-01

This paper presents experimental and modeling aspects of applying nuclear emission tomography to study fluid flow in laboratory packed porous media columns of the type frequently used in geophysics, geochemistry and hydrology research. Positron emission tomography (PET) and single photon emission computed tomography (SPECT) are used as non-invasive tools to obtain dynamic 3D images of radioactive tracer concentrations. Dynamic sequences obtained using 18 F-FDG PET are used to trace flow through a 5 cm diameter × 20 cm tall sand packed column with and without an impermeable obstacle. In addition, a custom-made rotating column setup placed in a clinical two-headed SPECT camera is used to image 99m Tc-DTPA tracer propagation in a through-flowing column (10 cm diameter × 30 cm tall) packed with recovered aquifer sediments. A computational fluid dynamics software package FLUENT is used to model the observed flow dynamics. Tracer distributions obtained in the simulations in the smaller column uniformly packed with sand and in the column with an obstacle are remarkably similar to the reconstructed images in the PET experiments. SPECT results demonstrate strongly non-uniform flow patterns for the larger column slurry-packed with sub-surface sediment and slow upward flow. In the numerical simulation of the SPECT study, two symmetric channels with increased permeability are prescribed along the column walls, which result in the emergence of two well-defined preferential flow paths. Methods and results of this work provide new opportunities in hydrologic and biogeochemical research. The primary target application for developed technologies is non-destructive, non-perturbing, quantitative imaging of flow dynamics within laboratory scale porous media systems.

Prospective Evaluation of 18F-Fluorodeoxyglucose Uptake in Postischemic Myocardium by Simultaneous Positron Emission Tomography/Magnetic Resonance Imaging as a Prognostic Marker of Functional Outcome.

PubMed

Rischpler, Christoph; Dirschinger, Ralf J; Nekolla, Stephan G; Kossmann, Hans; Nicolosi, Stefania; Hanus, Franziska; van Marwick, Sandra; Kunze, Karl P; Meinicke, Alexander; Götze, Katharina; Kastrati, Adnan; Langwieser, Nicolas; Ibrahim, Tareq; Nahrendorf, Matthias; Schwaiger, Markus; Laugwitz, Karl-Ludwig

2016-04-01

The immune system orchestrates the repair of infarcted myocardium. Imaging of the cellular inflammatory response by (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/magnetic resonance imaging in the heart has been demonstrated in preclinical and clinical studies. However, the clinical relevance of post-MI (18)F-FDG uptake in the heart has not been elucidated. The objective of this study was to explore the value of (18)F-FDG positron emission tomography/magnetic resonance imaging in patients after acute myocardial infarction as a biosignal for left ventricular functional outcome. We prospectively enrolled 49 patients with ST-segment-elevation myocardial infarction and performed (18)F-FDG positron emission tomography/magnetic resonance imaging 5 days after percutaneous coronary intervention and follow-up cardiac magnetic resonance imaging after 6 to 9 months. In a subset of patients, (99m)Tc-sestamibi single-photon emission computed tomography was performed with tracer injection before revascularization. Cellular innate immune response was analyzed at multiple time points. Segmental comparison of (18)F-FDG-uptake and late gadolinium enhancement showed substantial overlap (κ=0.66), whereas quantitative analysis demonstrated that (18)F-FDG extent exceeded late gadolinium enhancement extent (33.2±16.2% left ventricular myocardium versus 20.4±10.6% left ventricular myocardium, P<0.0001) and corresponded to the area at risk (r=0.87, P<0.0001). The peripheral blood count of CD14(high)/CD16(+) monocytes correlated with the infarction size and (18)F-FDG signal extent (r=0.53, P<0.002 and r=0.42, P<0.02, respectively). (18)F-FDG uptake in the infarcted myocardium was highest in areas with transmural scar, and the standardized uptake valuemean was associated with left ventricular functional outcome independent of infarct size (Δ ejection fraction: P<0.04, Δ end-diastolic volume: P<0.02, Δ end-systolic volume: P<0.005). In this study, the intensity of (18)F-FDG uptake in the myocardium after acute myocardial infarction correlated inversely with functional outcome at 6 months. Thus, (18)F-FDG uptake in infarcted myocardium may represent a novel biosignal of myocardial injury. © 2016 American Heart Association, Inc.

Miscellaneous indications in bone scintigraphy: metabolic bone diseases and malignant bone tumors.

PubMed

Cook, Gary J R; Gnanasegaran, Gopinath; Chua, Sue

2010-01-01

The diphosphonate bone scan is ideally suited to assess many global, focal or multifocal metabolic bone disorders and there remains a role for conventional bone scintigraphy in metabolic bone disorders at diagnosis, investigation of complications, and treatment response assessment. In contrast, the role of bone scintigraphy in the evaluation of primary malignant bone tumors has reduced with the improvement of morphologic imaging, such as computed tomography and magnetic resonance imaging. However, an increasing role for (18)F-fluorodeoxyglucose positron emission tomography and positron emission tomography/computed tomography is emerging as a functional assessment at diagnosis, staging, and neoadjuvant treatment response assessment.

Usefulness of fluorodeoxyglucose positron emission tomography/computed tomography for detection of a neuroblastic nodule in a ganglioneuroblastoma: a case report.

PubMed

Takeda, Yuka; Sano, Hideki; Kawano, Asuka; Mochizuki, Kazuhiro; Takahashi, Nobuhisa; Kobayashi, Shogo; Ohara, Yoshihiro; Tasaki, Kazuhiro; Hosoya, Mitusuaki; Kikuta, Atsushi

2018-05-03

Ganglioneuroblastoma, nodular is defined as a composite tumor of biologically distinct clones. The peripheral neuroblastic tumors in this category are characterized by the presence of grossly visible neuroblastoma nodules coexisting with ganglioneuroblastoma, intermixed, or with ganglioneuroma. Making a correct diagnosis of ganglioneuroblastoma, nodular is often difficult by biopsy or partial tumor resection, because the neuroblastic nodule could be hidden and not sampled for pathological examination. We report a case of a Japanese boy aged 3 years, 8 months, with an unresectable abdominal tumor and elevated vanillylmandelic acid and homovanillic acid levels. The initial biopsy was ganglioneuroma. However, after the second biopsy from a hidden neuroblastoma nodule that was clearly highlighted by fluorodeoxyglucose positron emission tomography/computed tomography, we reached the diagnosis of ganglioneuroblastoma, nodular. Because the nodule demonstrated neuroblastoma, differentiating subtype, with a low mitosis-karyorrhexis index (favorable histology) and nonamplified MYCN, the boy was treated according to the intermediate-risk protocol and is now alive and well 4 years after the diagnosis. This case illustrates the critical role of fluorodeoxyglucose positron emission tomography/computed tomography for detecting a neuroblastoma nodule in a ganglioneuroblastoma.

Time-resolved tomography using acoustic emissions in the laboratory, and application to sandstone compaction

NASA Astrophysics Data System (ADS)

Brantut, Nicolas

2018-02-01

Acoustic emission and active ultrasonic wave velocity monitoring are often performed during laboratory rock deformation experiments, but are typically processed separately to yield homogenised wave velocity measurements and approximate source locations. Here I present a numerical method and its implementation in a free software to perform a joint inversion of acoustic emission locations together with the three-dimensional, anisotropic P-wave structure of laboratory samples. The data used are the P-wave first arrivals obtained from acoustic emissions and active ultrasonic measurements. The model parameters are the source locations and the P-wave velocity and anisotropy parameter (assuming transverse isotropy) at discrete points in the material. The forward problem is solved using the fast marching method, and the inverse problem is solved by the quasi-Newton method. The algorithms are implemented within an integrated free software package called FaATSO (Fast Marching Acoustic Emission Tomography using Standard Optimisation). The code is employed to study the formation of compaction bands in a porous sandstone. During deformation, a front of acoustic emissions progresses from one end of the sample, associated with the formation of a sequence of horizontal compaction bands. Behind the active front, only sparse acoustic emissions are observed, but the tomography reveals that the P-wave velocity has dropped by up to 15%, with an increase in anisotropy of up to 20%. Compaction bands in sandstones are therefore shown to produce sharp changes in seismic properties. This result highlights the potential of the methodology to image temporal variations of elastic properties in complex geomaterials, including the dramatic, localised changes associated with microcracking and damage generation.

The Neural Correlates of Driving Performance Identified Using Positron Emission Tomography

ERIC Educational Resources Information Center

Horikawa, E.; Okamura, N.; Tashiro, M.; Sakurada, Y.; Maruyama, M.; Arai, H.; Yamaguchi, K.; Sasaki, H.; Yanai, K.; Itoh, M.

2005-01-01

Driving is a complex behavior involving multiple cognitive domains. To identify neural correlates of driving performance, [^1^5O]H"2O positron emission tomography was performed using a simulated driving task. Compared with the resting condition, simulated driving increased regional cerebral blood flow (rCBF) in the cerebellum, occipital, and…

76 FR 54473 - Guidance on Positron Emission Tomography Drug Applications-Content and Format for New Drug...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-01

... (formerly Docket No. 00D-0892)] Guidance on Positron Emission Tomography Drug Applications-- Content and... the availability of a guidance for industry entitled ``PET Drug Applications--Content and Format for... guidance for industry entitled ``PET Drug Applications--Content and Format for NDAs and ANDAs.'' The...

The early years of single photon emission computed tomography (SPECT): an anthology of selected reminiscences.

PubMed

Jaszczak, Ronald Jack

2006-07-07

The origin of SPECT can be found in pioneering experiments on emission tomography performed approximately 50 years ago. This historical review consists of a compilation of first person recollections from nine trailblazing scientists who shaped the early years of SPECT instrumentation during the 1960s and 1970s.

76 FR 6144 - Positron Emission Tomography; Notice of Public Meeting; Request for Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-03

... injection, and sodium fluoride F 18 injection used in positron emission tomography (PET) imaging. By... be submitted for FDG F 18 injection, ammonia N 13 injection, and sodium fluoride F 18 injection used..., ammonia N 13 injection, and sodium fluoride F 18 injection. FDA will present information designed to...

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.

Time-resolved acoustic emission tomography in the laboratory: tracking localised damage in rocks

NASA Astrophysics Data System (ADS)

Brantut, N.

2017-12-01

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, anisotropic 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.The method is used to track the propagation of compaction bands in a porous sandstone deformed in the ductile, cataclastic flow regime under triaxial stress conditions. Near the yield point, a compaction front forms at one end of the sample, and slowly progresses towards the other end. The front is illuminated by clusters of Acoustic Emissions, and leaves behind a heavily damaged material where the P-wave speed has dropped by up to 20%.The technique opens new possibilities to track in-situ strain localisation and damage around laboratory faults, and preliminary results on quasi-static rupture in granite will be presented.

18F-AV-1451 tau PET imaging correlates strongly with tau neuropathology in MAPT mutation carriers

PubMed Central

Puschmann, Andreas; Schöll, Michael; Ohlsson, Tomas; van Swieten, John; Honer, Michael; Englund, Elisabet

2016-01-01

Abstract Tau positron emission tomography ligands provide the novel possibility to image tau pathology in vivo. However, little is known about how in vivo brain uptake of tau positron emission tomography ligands relates to tau aggregates observed post-mortem. We performed tau positron emission tomography imaging with 18F-AV-1451 in three patients harbouring a p.R406W mutation in the MAPT gene, encoding tau. This mutation results in 3- and 4-repeat tau aggregates similar to those in Alzheimer’s disease, and many of the mutation carriers initially suffer from memory impairment and temporal lobe atrophy. Two patients with short disease duration and isolated memory impairment exhibited 18F-AV-1451 uptake mainly in the hippocampus and adjacent temporal lobe regions, correlating with glucose hypometabolism in corresponding regions. One patient died after 26 years of disease duration with dementia and behavioural deficits. Pre-mortem, there was 18F-AV-1451 uptake in the temporal and frontal lobes, as well as in the basal ganglia, which strongly correlated with the regional extent and amount of tau pathology in post-mortem brain sections. Amyloid-β (18F-flutemetamol) positron emission tomography scans were negative in all cases, as were stainings of brain sections for amyloid. This provides strong evidence that 18F-AV-1451 positron emission tomography can be used to accurately quantify in vivo the regional distribution of hyperphosphorylated tau protein. PMID:27357347

The Role of Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography in Aggressive Histological Subtypes of Thyroid Cancer: An Overview

PubMed Central

Treglia, Giorgio; Annunziata, Salvatore; Muoio, Barbara; Salvatori, Massimo; Ceriani, Luca; Giovanella, Luca

2013-01-01

Aggressive histological subtypes of thyroid cancer are rare and have a poor prognosis. The most important aggressive subtypes of thyroid cancer are Hürthle cell carcinoma (HCTC) and anaplastic and poorly differentiated carcinoma (ATC and PDTC). The American Thyroid Association recently published guidelines for the management of patients with ATC, but no specific guidelines have been done about HCTC. We performed an overview of the literature about the role of Fluorine-18-Fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography (FDG-PET or PET/CT) in aggressive histological subtypes of thyroid cancer. Only few original studies about the role of FDG-PET or PET/CT in HCTC, PDTC, and ATC have been published in the literature. FDG-PET or PET/CT seems to be useful in staging or followup of invasive and metastatic HCTC. FDG-PET or PET/CT should be used in patients with ATC in initial staging and in the followup after surgery to evaluate metastatic disease. Some authors suggest the use of FDG-PET/CT in staging of PDTC, but more studies are needed to define the diagnostic use of FDG-PET/CT in this setting. Limited experience suggests the usefulness of FDG-PET or PET/CT in patients with more aggressive histological subtypes of DTC. However, DTC presenting as radioiodine refractory and FDG-PET positive should be considered aggressive tumours with poor prognosis. PMID:23653645

Single-Photon Emission Computed Tomography/Computed Tomography Imaging in a Rabbit Model of Emphysema Reveals Ongoing Apoptosis In Vivo

PubMed Central

Goldklang, Monica P.; Tekabe, Yared; Zelonina, Tina; Trischler, Jordis; Xiao, Rui; Stearns, Kyle; Romanov, Alexander; Muzio, Valeria; Shiomi, Takayuki; Johnson, Lynne L.

2016-01-01

Evaluation of lung disease is limited by the inability to visualize ongoing pathological processes. Molecular imaging that targets cellular processes related to disease pathogenesis has the potential to assess disease activity over time to allow intervention before lung destruction. Because apoptosis is a critical component of lung damage in emphysema, a functional imaging approach was taken to determine if targeting apoptosis in a smoke exposure model would allow the quantification of early lung damage in vivo. Rabbits were exposed to cigarette smoke for 4 or 16 weeks and underwent single-photon emission computed tomography/computed tomography scanning using technetium-99m–rhAnnexin V-128. Imaging results were correlated with ex vivo tissue analysis to validate the presence of lung destruction and apoptosis. Lung computed tomography scans of long-term smoke–exposed rabbits exhibit anatomical similarities to human emphysema, with increased lung volumes compared with controls. Morphometry on lung tissue confirmed increased mean linear intercept and destructive index at 16 weeks of smoke exposure and compliance measurements documented physiological changes of emphysema. Tissue and lavage analysis displayed the hallmarks of smoke exposure, including increased tissue cellularity and protease activity. Technetium-99m–rhAnnexin V-128 single-photon emission computed tomography signal was increased after smoke exposure at 4 and 16 weeks, with confirmation of increased apoptosis through terminal deoxynucleotidyl transferase dUTP nick end labeling staining and increased tissue neutral sphingomyelinase activity in the tissue. These studies not only describe a novel emphysema model for use with future therapeutic applications, but, most importantly, also characterize a promising imaging modality that identifies ongoing destructive cellular processes within the lung. PMID:27483341

The optimality of different strategies for supplemental staging of non-small-cell lung cancer: a health economic decision analysis.

PubMed

Søgaard, Rikke; Fischer, Barbara Malene B; Mortensen, Jann; Rasmussen, Torben R; Lassen, Ulrik

2013-01-01

To assess the expected costs and outcomes of alternative strategies for staging of lung cancer to inform a Danish National Health Service perspective about the most cost-effective strategy. A decision tree was specified for patients with a confirmed diagnosis of non-small-cell lung cancer. Six strategies were defined from relevant combinations of mediastinoscopy, endoscopic or endobronchial ultrasound with needle aspiration, and combined positron emission tomography-computed tomography with F18-fluorodeoxyglucose. Patients without distant metastases and central or contralateral nodal involvement (N2/N3) were considered to be candidates for surgical resection. Diagnostic accuracies were informed from literature reviews, prevalence and survival from the Danish Lung Cancer Registry, and procedure costs from national average tariffs. All parameters were specified probabilistically to determine the joint decision uncertainty. The cost-effectiveness analysis was based on the net present value of expected costs and life years accrued over a time horizon of 5 years. At threshold values of around €30,000 for cost-effectiveness, it was found to be cost-effective to send all patients to positron emission tomography-computed tomography with confirmation of positive findings on nodal involvement by endobronchial ultrasound. This result appeared robust in deterministic sensitivity analysis. The expected value of perfect information was estimated at €52 per patient, indicating that further research might be worthwhile. The policy recommendation is to make combined positron emission tomography-computed tomography and endobronchial ultrasound available for supplemental staging of patients with non-small-cell lung cancer. The effects of alternative strategies on patients' quality of life, however, should be examined in future studies. Copyright © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Evaluation of dosimetry and image of very low-dose computed tomography attenuation correction for pediatric positron emission tomography/computed tomography: phantom study

NASA Astrophysics Data System (ADS)

Bahn, Y. K.; Park, H. H.; Lee, C. H.; Kim, H. S.; Lyu, K. Y.; Dong, K. R.; Chung, W. K.; Cho, J. H.

2014-04-01

In this study, phantom was used to evaluate attenuation correction computed tomography (CT) dose and image in case of pediatric positron emission tomography (PET)/CT scan. Three PET/CT scanners were used along with acryl phantom in the size for infant and ion-chamber dosimeter. The CT image acquisition conditions were changed from 10 to 20, 40, 80, 100 and 160 mA and from 80 to 100, 120 and 140 kVp, which aimed at evaluating penetrate dose and computed tomography dose indexvolume (CTDIvol) value. And NEMA PET Phantom™ was used to obtain PET image under the same CT conditions in order to evaluate each attenuation-corrected PET image based on standard uptake value (SUV) value and signal-to-noise ratio (SNR). In general, the penetrate dose was reduced by around 92% under the minimum CT conditions (80 kVp and 10 mA) with the decrease in CTDIvol value by around 88%, compared with the pediatric abdomen CT conditions (100 kVp and 100 mA). The PET image with its attenuation corrected according to each CT condition showed no change in SUV value and no influence on the SNR. In conclusion, if the minimum dose CT that is properly applied to body of pediatric patient is corrected for attenuation to ensure that the effective dose is reduced by around 90% or more compared with that for adult patient, this will be useful to reduce radiation exposure level.

Fusion Imaging: A Novel Staging Modality in Testis Cancer

PubMed Central

Sterbis, Joseph R.; Rice, Kevin R.; Javitt, Marcia C.; Schenkman, Noah S.; Brassell, Stephen A.

2010-01-01

Objective: Computed tomography and chest radiographs provide the standard imaging for staging, treatment, and surveillance of testicular germ cell neoplasms. Positron emission tomography has recently been utilized for staging, but is somewhat limited in its ability to provide anatomic localization. Fusion imaging combines the metabolic information provided by positron emission tomography with the anatomic precision of computed tomography. To the best of our knowledge, this represents the first study of the effectiveness using fusion imaging in evaluation of patients with testis cancer. Methods: A prospective study of 49 patients presenting to Walter Reed Army Medical Center with testicular cancer from 2003 to 2009 was performed. Fusion imaging was compared with conventional imaging, tumor markers, pathologic results, and clinical follow-up. Results: There were 14 true positives, 33 true negatives, 1 false positive, and 1 false negative. Sensitivity, specificity, positive predictive value, and negative predictive value were 93.3, 97.0, 93.3, and 97.0% respectively. In 11 patient scenarios, fusion imaging differed from conventional imaging. Utility was found in superior lesion detection compared to helical computed tomography due to anatomical/functional image co-registration, detection of micrometastasis in lymph nodes (pathologic nodes < 1cm), surveillance for recurrence post-chemotherapy, differentiating fibrosis from active disease in nodes < 2.5cm, and acting as a quality assurance measure to computed tomography alone. Conclusions: In addition to demonstrating a sensitivity and specificity comparable or superior to conventional imaging, fusion imaging shows promise in providing additive data that may assist in clinical decision-making. PMID:21103077

Fusion imaging: a novel staging modality in testis cancer.

PubMed

Sterbis, Joseph R; Rice, Kevin R; Javitt, Marcia C; Schenkman, Noah S; Brassell, Stephen A

2010-11-05

Computed tomography and chest radiographs provide the standard imaging for staging, treatment, and surveillance of testicular germ cell neoplasms. Positron emission tomography has recently been utilized for staging, but is somewhat limited in its ability to provide anatomic localization. Fusion imaging combines the metabolic information provided by positron emission tomography with the anatomic precision of computed tomography. To the best of our knowledge, this represents the first study of the effectiveness using fusion imaging in evaluation of patients with testis cancer. A prospective study of 49 patients presenting to Walter Reed Army Medical Center with testicular cancer from 2003 to 2009 was performed. Fusion imaging was compared with conventional imaging, tumor markers, pathologic results, and clinical follow-up. There were 14 true positives, 33 true negatives, 1 false positive, and 1 false negative. Sensitivity, specificity, positive predictive value, and negative predictive value were 93.3, 97.0, 93.3, and 97.0% respectively. In 11 patient scenarios, fusion imaging differed from conventional imaging. Utility was found in superior lesion detection compared to helical computed tomography due to anatomical/functional image co-registration, detection of micrometastasis in lymph nodes (pathologic nodes < 1cm), surveillance for recurrence post-chemotherapy, differentiating fibrosis from active disease in nodes < 2.5cm, and acting as a quality assurance measure to computed tomography alone. In addition to demonstrating a sensitivity and specificity comparable or superior to conventional imaging, fusion imaging shows promise in providing additive data that may assist in clinical decision-making.

Preoperative 18F-FDG-PET/CT imaging and sentinel node biopsy in the detection of regional lymph node metastases in malignant melanoma.

PubMed

Singh, Baljinder; Ezziddin, Samer; Palmedo, Holger; Reinhardt, Michael; Strunk, Holger; Tüting, Thomas; Biersack, Hans-Jürgen; Ahmadzadehfar, Hojjat

2008-10-01

The objective of this study was to evaluate the role of preoperative 18F-fluorodeoxyglucose-positron emission tomography/computed tomography scanning, preoperative lymphoscintigraphy (LS), and sentinel lymph node biopsy in patients with malignant melanoma. Fifty-two patients (36 men: 16 women; mean age 55.0+/-13.0 years; median age 61 years; range 17-76 years) with malignant melanoma were selected. According to the latest version of the American Joint Committee on Cancer staging system, the disease in the study patients was initially classified as either stage I or II. The other primary tumor characteristics were mean Breslow depth=2.87 mm and median=2 mm; range 1-12.0 mm and Clarks levels III-V. None of the study patients had clinical or radiological evidence of regional lymph node metastatic disease. At least one sentinel node was identified in all patients. Preoperative LS detected a total of 111 sentinel lymph nodes (average 2.13 sentinel lymph node per patient) and demonstrated a single nodal draining basin in 38 (73%) patients and multiple (2-3 draining basins) in the remaining 14 (27%) patients. Fourteen out of the 52 patients (27%) had at least one involved sentinel node. Positron emission tomography was true positive in two patients with a sentinel node greater than 1 cm and false positive in two other patients. In this study, the detection of sentinel lymph node by LS and gamma probe had a sensitivity of 100%. In contrast, 18F-FDG-PET imaging demonstrated very low sensitivity (14.3%; 95% CI, 2.5 to 44%) and positive predictive value (50%; 95% CI, 9 to 90%) for localizing the subclinical nodal metastases. The specificity, net present value, and diagnostic accuracy were 94.7, 75, and 73%, respectively. Preoperative fluorodeoxyglucose-positron emission tomography/computed tomography imaging is not able to substitute LS/sentinel lymph node biopsy in patients at stage I or II.

Influence of the Pixel Sizes of Reference Computed Tomography on Single-photon Emission Computed Tomography Image Reconstruction Using Conjugate-gradient Algorithm.

PubMed

Okuda, Kyohei; Sakimoto, Shota; Fujii, Susumu; Ida, Tomonobu; Moriyama, Shigeru

The frame-of-reference using computed-tomography (CT) coordinate system on single-photon emission computed tomography (SPECT) reconstruction is one of the advanced characteristics of the xSPECT reconstruction system. The aim of this study was to reveal the influence of the high-resolution frame-of-reference on the xSPECT reconstruction. 99m Tc line-source phantom and National Electrical Manufacturers Association (NEMA) image quality phantom were scanned using the SPECT/CT system. xSPECT reconstructions were performed with the reference CT images in different sizes of the display field-of-view (DFOV) and pixel. The pixel sizes of the reconstructed xSPECT images were close to 2.4 mm, which is acquired as originally projection data, even if the reference CT resolution was varied. The full width at half maximum (FWHM) of the line-source, absolute recovery coefficient, and background variability of image quality phantom were independent on the sizes of DFOV in the reference CT images. The results of this study revealed that the image quality of the reconstructed xSPECT images is not influenced by the resolution of frame-of-reference on SPECT reconstruction.

Effects of BDNF Val66Met polymorphism on brain metabolism in Alzheimer's disease.

PubMed

Xu, Cunlu; Wang, Zhenhua; Fan, Ming; Liu, Bing; Song, Ming; Zhen, Xiantong; Jiang, Tianzi

2010-08-23

Earlier studies showed that the Val66Met polymorphisms of the brain-derived neurotrophic factor differentially affect gray matter volume and brain region activities. This study used resting positron emission tomography to investigate the relationship between the polymorphisms of Val66Met and the regional cerebral metabolic rate in the brain. We analyzed the positron emission tomography images of 215 patients from the Alzheimer's Disease Neuroimaging Initiative and found significant differences in the parahippocampal gyrus, superior temporal gyrus, prefrontal cortex, and inferior parietal lobule when comparing Met carriers with noncarriers among both the normal controls and those with mild cognitive impairment. For those with Alzheimer's disease, we also found additional differences in the bilateral insula between the carriers and noncarriers.

REVIEW: The early years of single photon emission computed tomography (SPECT): an anthology of selected reminiscences

NASA Astrophysics Data System (ADS)

Jaszczak, Ronald Jack

2006-07-01

The origin of SPECT can be found in pioneering experiments on emission tomography performed approximately 50 years ago. This historical review consists of a compilation of first person recollections from nine trailblazing scientists who shaped the early years of SPECT instrumentation during the 1960s and 1970s.

Positron Emission Tomography Methods with Potential for Increased Understanding of Mental Retardation and Developmental Disabilities

ERIC Educational Resources Information Center

Sundaram, Senthil K.; Chugani, Harry T.; Chugani, Diane C.

2005-01-01

Positron emission tomography (PET) is a technique that enables imaging of the distribution of radiolabeled tracers designed to track biochemical and molecular processes in the body after intravenous injection or inhalation. New strategies for the use of radiolabeled tracers hold potential for imaging gene expression in the brain during development…

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.

(/sup 11/C)clorgyline and (/sup 11/C)-L-deprenyl and their use in measuring functional monoamine oxidase activity in the brain using positron emission tomography

DOEpatents

Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.

1986-04-17

This invention involves a new strategy for imaging the activity of the enzyme monoamine oxidase in the living body by using /sup 11/C-labeled enzyme inhibitors which bind irreversibly to an enzyme as a result of catalysis. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography. 2 figs.

Noninvasive studies of human visual cortex using neuromagnetic techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aine, C.J.; George, J.S.; Supek, S.

1990-01-01

The major goals of noninvasive studies of the human visual cortex are: to increase knowledge of the functional organization of cortical visual pathways; and to develop noninvasive clinical tests for the assessment of cortical function. Noninvasive techniques suitable for studies of the structure and function of human visual cortex include magnetic resonance imaging (MRI), positron emission tomography (PET), single photon emission tomography (SPECT), scalp recorded event-related potentials (ERPs), and event-related magnetic fields (ERFs). The primary challenge faced by noninvasive functional measures is to optimize the spatial and temporal resolution of the measurement and analytic techniques in order to effectively characterizemore » the spatial and temporal variations in patterns of neuronal activity. In this paper we review the use of neuromagnetic techniques for this purpose. 8 refs., 3 figs.« less

Clinical and Radiographic Response of Extramedullary Leukemia in Patients Treated With Gemtuzumab Ozogamicin.

PubMed

McNeil, Michael J; Parisi, Marguerite T; Hijiya, Nobuko; Meshinchi, Soheil; Cooper, Todd; Tarlock, Katherine

2018-05-04

Extramedullary leukemia (EML) is common in pediatric acute leukemia and can present at diagnosis or relapse. CD33 is detected on the surface of myeloid blasts in many patients with acute myelogenous leukemia and is the target of the antibody drug conjugate gemtuzumab ozogamicin (GO). Here we present 2 patients with CD33 EML treated with GO. They achieved significant response, with reduction of EML on both clinical and radiographic exams, specifically fluorine fluorodeoxyglucose positron emission tomography/computed tomography, demonstrating potential for targeted therapy with GO as a means of treating EML in patients with CD33 leukemia and the utility of fluorine fluorodeoxyglucose positron emission tomography/computed tomography monitoring in EML.

68Gallium-Arginine-Glycine-Aspartic Acid and 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Chondroblastic Osteosarcoma of the Skull.

PubMed

Orunmuyi, Akintunde; Modiselle, Moshe; Lengana, Thabo; Ebenhan, Thomas; Vorster, Mariza; Sathekge, Mike

2017-09-01

We report the case of a 32 year-old male with Chondroblastic Osteosarcoma of the skull, which was imaged with both 18 [F]fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) and 68 Gallium-arginine-glycine-aspartic acid ( 68 Ga-RGD) PET/CT. The 18 F-FDG PET/CT did not demonstrate the tumour, whereas the 68 Ga-RGD PET/CT clearly depicted a left-sided frontal tumour. 68 Ga-RGD PET/CT may be a clinically useful imaging modality for early detection of recurrent osteosarcoma, considering the limitations of 18 F-FDG PET in a setting of low glycolytic activity.

Rationale and design of dal-PLAQUE: A study assessing efficacy and safety of dalcetrapib on progression or regression of atherosclerosis using magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography/computed tomography

PubMed Central

Fayad, Zahi A.; Mani, Venkatesh; Woodward, Mark; Kallend, David; Bansilal, Sameer; Pozza, Joseph; Burgess, Tracy; Fuster, Valentin; Rudd, James H. F.; Tawakol, Ahmed; Farkouh, Michael E.

2014-01-01

dal-PLAQUE is a placebo-controlled multicenter study designed to assess the effect of dalcetrapib on imaging measures of plaque inflammation and plaque burden. dal-PLAQUE is a multimodality imaging study in the context of the large dal-HEART Program. Decreased high-density lipoprotein cholesterol is linked to increased risk of coronary heart disease (CHD). Dalcetrapib, a compound that increases high-density lipoprotein cholesterol by modulating cholesteryl ester transfer protein, is being studied to assess if it can reduce the progression of atherosclerotic disease and thereby decrease cardiovascular morbidity and mortality. Patients with CHD or CHD-risk equivalents were randomized to receive 600 mg dalcetrapib or placebo daily for 24 months, in addition to conventional lipid-lowering medication and other medications for cardiovascular risk factors. The primary outcomes are the effect of dalcetrapib on 18F-fluorodeoxyglucose positron emission tomography target-to-background ratio after 6 months and magnetic resonance imaging (MRI) plaque burden (wall area, wall thickness, total vessel area, and wall area/total vessel area ratio) after 12 months. Secondary objectives include positron emission tomography target-to-background ratio at 3 months and MRI plaque burden at 6 and 24 months; plaque composition at 6, 12, and 24 months; and aortic compliance at 6 months. A tertiary objective is to examine the dynamic contrast-enhanced MRI parameters of plaque neovascularization. In total, 189 subjects entered screening, and 130 were randomized. dal-PLAQUE will provide important information on the effects of dalcetrapib on markers of inflammation and atherosclerotic plaque burden and, thereby, on the safety of cholesteryl ester transfer protein modulation with dalcetrapib. Results are expected in 2011. PMID:21835280

Arterial Spin Labeling Perfusion Magnetic Resonance Image with Dual Postlabeling Delay: A Correlative Study with Acetazolamide Loading (123)I-Iodoamphetamine Single-Photon Emission Computed Tomography.

PubMed

Haga, Sei; Morioka, Takato; Shimogawa, Takafumi; Akiyama, Tomoaki; Murao, Kei; Kanazawa, Yuka; Sayama, Tetsuro; Arakawa, Shuji

2016-01-01

Perfusion magnetic resonance image with arterial spin labeling (ASL) provides a completely noninvasive measurement of cerebral blood flow (CBF). However, arterial transient times can have a marked effect on the ASL signal. For example, a single postlabeling delay (PLD) of 1.5 seconds underestimates the slowly streaming collateral pathways that maintain the cerebrovascular reserve (CVR). To overcome this limitation, we developed a dual PLD method. A dual PLD method of 1.5  and 2.5 seconds was compared with (123)I-iodoamphetamine single-photon emission computed tomography with acetazolamide loading to assess CVR in 10 patients with steno-occlusive cerebrovascular disease. In 5 cases (Group A), dual PLD-ASL demonstrated low CBF with 1.5-second PLD in the target area, whereas CBF was improved with 2.5-second PLD. In the other 5 cases (Group B), dual PLD-ASL depicted low CBF with 1.5-second PLD, and no improvement in CBF with 2.5-second PLD in the target area was observed. On single-photon emission computed tomography, CVR was maintained in Group A but decreased in Group B. Although dual PLD methods may not be a completely alternative test for (123)I-iodoamphetamine single-photon emission computed tomography with acetazolamide loading, it is a feasible, simple, noninvasive, and repeatable technique for assessing CVR, even when employed in a routine clinical setting. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

[Features of Acquired Immunodeficiency Syndrome-related Lymphoma on (18)F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography].

PubMed

Niu, Na; Zhu, Zhao-hui; Ma, Yan-ru; Xing, Hai-qun; Li, Fang

2015-10-01

To analyze the imaging features of (18)F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography(PET)/computed tomography (CT) in acquired immune deficiency syndrome-related lymphoma (ARL) patients correlated with their clinical signs, symptoms, and treatments. Five ARL patients underwent ¹⁸F-FDG PET/CT at Peking Union Medical College Hospital from October 2008 to January 2013. Two patients received two additional follow-up studies 6 months later. Among these 5 patients, ¹⁸FDG-PET/CT helped in diagnosis of two patient and changed therapeutic strategy in other two patients. In two patients underwent ¹⁸F-FDG PET/CT brain scans, low-metabolism lesion was newly found in cerebral cortex. Of 4 patients receiving highly active antiretroviral therapy, PET/CT also demonstrated diffusely elevated ¹⁸F-FDG uptake in subcutaneous adipose tissue in two patients. ¹⁸F-FDG PET/CT is a highly useful tool in the diagnosis and treatment of ARL patients, in particular in the identification of associated encephalopathy and lipodystrophy.

Preoperative evaluation of patients with squamous cell carcinoma of the oral cavity: fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography and ultrasonography versus histopathology.

PubMed

Sugawara, Chieko; Takahashi, Akira; Kubo, Michiko; Otsuka, Hideki; Ishimaru, Naozumi; Miyamoto, Youji; Honda, Eiichi

2012-10-01

The purpose of this retrospective study was to compare fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and ultrasonography (US) in the staging of patients with squamous cell carcinoma of the oral cavity. We compared preoperative evaluations regarding lymph nodes using PET/CT, US, and both methods. The cutoff for the maximum standardized uptake value (SUV(max)) in PET/CT was set at 2.7 by a receiver operating characteristic analysis that was based on the histopathological diagnosis. US was used to examine internal structural changes on B-mode and hilar vascularity on power Doppler. The performance of PET/CT and US in combination was better than that of each modality separately. However, there were histopathological changes that could not be detected on PET/CT or US. PET/CT could not detect nodes with necrotic or cystic changes. US could not detect lymph nodes that did not have abnormal structures. PET/CT and US are complementary tools to evaluate preoperative patients. Copyright © 2012 Elsevier Inc. All rights reserved.

The role of Fluorine-18-Fluorodeoxyglucose positron emission tomography in staging and restaging of patients with osteosarcoma.

PubMed

Quartuccio, Natale; Treglia, Giorgio; Salsano, Marco; Mattoli, Maria Vittoria; Muoio, Barbara; Piccardo, Arnoldo; Lopci, Egesta; Cistaro, Angelina

2013-06-01

The objective of this study is to systematically review the role of positron emission tomography (PET) and PET/computed tomography (PET/CT) with Fluorine-18-Fluorodeoxyglucose (FDG) in patients with osteosarcoma (OS). A comprehensive literature search of published studies through October 10(th), 2012 in PubMed/MEDLINE, Embase and Scopus databases regarding whole-body FDG-PET and FDG-PET/CT in patients with OS was performed. We identified 13 studies including 289 patients with OS. With regard to the staging and restaging of OS, the diagnostic performance of FDG-PET and PET/CT seem to be high; FDG-PET and PET/CT seem to be superior to bone scintigraphy and conventional imaging methods in detecting bone metastases; conversely, spiral CT seems to be superior to FDG-PET in detecting pulmonary metastases from OS. Metabolic imaging may provide additional information in the evaluation of OS patients. The combination of FDG-PET or FDG-PET/CT with conventional imaging methods seems to be a valuable tool in the staging and restaging of OS and may have a relevant impact on the treatment planning.

Neuroimaging studies in schizophrenia: an overview of research from Asia.

PubMed

Narayanaswamy, Janardhanan C; Venkatasubramanian, Ganesan; Gangadhar, Bangalore N

2012-10-01

Neuroimaging studies in schizophrenia help clarify the neural substrates underlying the pathogenesis of this neuropsychiatric disorder. Contemporary brain imaging in schizophrenia is predominated by magnetic resonance imaging (MRI)-based research approaches. This review focuses on the various imaging studies from India and their relevance to the understanding of brain abnormalities in schizophrenia. The existing studies are predominantly comprised of structural MRI reports involving region-of-interest and voxel-based morphometry approaches, magnetic resonance spectroscopy and single-photon emission computed tomography/positron emission tomography (SPECT/PET) studies. Most of these studies are significant in that they have evaluated antipsychotic-naïve schizophrenia patients--a relatively difficult population to obtain in contemporary research. Findings of these studies offer robust support to the existence of significant brain abnormalities at very early stages of the disorder. In addition, theoretically relevant relationships between these brain abnormalities and developmental aberrations suggest possible neurodevelopmental basis for these brain deficits.

Integration of Quantitative Positron Emission Tomography Absolute Myocardial Blood Flow Measurements in the Clinical Management of Coronary Artery Disease.

PubMed

Gewirtz, Henry; Dilsizian, Vasken

2016-05-31

In the >40 years since planar myocardial imaging with(43)K-potassium was introduced into clinical research and management of patients with coronary artery disease (CAD), diagnosis and treatment have undergone profound scientific and technological changes. One such innovation is the current state-of-the-art hardware and software for positron emission tomography myocardial perfusion imaging, which has advanced it from a strictly research-oriented modality to a clinically valuable tool. This review traces the evolving role of quantitative positron emission tomography measurements of myocardial blood flow in the evaluation and management of patients with CAD. It presents methodology, currently or soon to be available, that offers a paradigm shift in CAD management. Heretofore, radionuclide myocardial perfusion imaging has been primarily qualitative or at best semiquantitative in nature, assessing regional perfusion in relative terms. Thus, unlike so many facets of modern cardiovascular practice and CAD management, which depend, for example, on absolute values of key parameters such as arterial and left ventricular pressures, serum lipoprotein, and other biomarker levels, the absolute levels of rest and maximal myocardial blood flow have yet to be incorporated into routine clinical practice even in most positron emission tomography centers where the potential to do so exists. Accordingly, this review focuses on potential value added for improving clinical CAD practice by measuring the absolute level of rest and maximal myocardial blood flow. Physiological principles and imaging fundamentals necessary to understand how positron emission tomography makes robust, quantitative measurements of myocardial blood flow possible are highlighted. © 2016 American Heart Association, Inc.

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.

Halogenated naphthyl methoxy piperidines for mapping serotonin transporter sites

DOEpatents

Goodman, Mark M.; Faraj, Bahjat

1999-01-01

Halogenated naphthyl methoxy piperidines having a strong affinity for the serotonin transporter are disclosed. Those compounds can be labeled with positron-emitting and/or gamma emitting halogen isotopes by a late step synthesis that maximizes the useable lifeterm of the label. The labeled compounds are useful for localizing serotonin transporter sites by positron emission tomography and/or single photon emission computed tomography.

Halogenated naphthyl methoxy piperidines for mapping serotonin transporter sites

DOEpatents

Goodman, M.M.; Faraj, B.

1999-07-06

Halogenated naphthyl methoxy piperidines having a strong affinity for the serotonin transporter are disclosed. Those compounds can be labeled with positron-emitting and/or gamma emitting halogen isotopes by a late step synthesis that maximizes the useable lifeterm of the label. The labeled compounds are useful for localizing serotonin transporter sites by positron emission tomography and/or single photon emission computed tomography.

Attention Performance in Autism and Regional Brain Metabolic Rate Assessed by Positron Emission Tomography. Brief Report.

ERIC Educational Resources Information Center

Buchsbaum, M. S.; And Others

1992-01-01

This evaluation of seven high functioning adults with autism utilized positron emission tomography on a visual vigilance task. Although the subjects, as a group, did as well as normal controls on the task, there was a lack of normal hemispheric asymmetry in glucose metabolic rate. A heterogeneous etiology for autism is suggested to explain…

THERANOSTICS: From Molecular Imaging Using Ga-68 Labeled Tracers and PET/CT to Personalized Radionuclide Therapy - The Bad Berka Experience

PubMed Central

Baum, Richard P.; Kulkarni, Harshad R.

2012-01-01

The acronym THERANOSTICS epitomizes the inseparability of diagnosis and therapy, the pillars of medicine and takes into account personalized management of disease for a specific patient. Molecular phenotypes of neoplasms can be determined by molecular imaging with specific probes using positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), or optical methods, so that the treatment is specifically targeted against the tumor and its environment. To meet these demands, we need to define the targets, ligands, coupling and labeling chemistry, the most appropriate radionuclides, biodistribution modifiers, and finally select the right patients for the personalized treatment. THERANOSTICS of neuroendocrine tumors (NETs) using Ga-68 labeled tracers for diagnostics with positron emission tomography/ computed tomography (PET/CT), and using Lu-177 or other metallic radionuclides for radionuclide therapy by applying the same peptide proves that personalized radionuclide therapy today is already a fact and not a fiction. PMID:22768024

Simultaneous reconstruction of 3D refractive index, temperature, and intensity distribution of combustion flame by double computed tomography technologies based on spatial phase-shifting method

NASA Astrophysics Data System (ADS)

Guo, Zhenyan; Song, Yang; Yuan, Qun; Wulan, Tuya; Chen, Lei

2017-06-01

In this paper, a transient multi-parameter three-dimensional (3D) reconstruction method is proposed to diagnose and visualize a combustion flow field. Emission and transmission tomography based on spatial phase-shifted technology are combined to reconstruct, simultaneously, the various physical parameter distributions of a propane flame. Two cameras triggered by the internal trigger mode capture the projection information of the emission and moiré tomography, respectively. A two-step spatial phase-shifting method is applied to extract the phase distribution in the moiré fringes. By using the filtered back-projection algorithm, we reconstruct the 3D refractive-index distribution of the combustion flow field. Finally, the 3D temperature distribution of the flame is obtained from the refractive index distribution using the Gladstone-Dale equation. Meanwhile, the 3D intensity distribution is reconstructed based on the radiation projections from the emission tomography. Therefore, the structure and edge information of the propane flame are well visualized.

THERANOSTICS: From Molecular Imaging Using Ga-68 Labeled Tracers and PET/CT to Personalized Radionuclide Therapy - The Bad Berka Experience.

PubMed

Baum, Richard P; Kulkarni, Harshad R

2012-01-01

The acronym THERANOSTICS epitomizes the inseparability of diagnosis and therapy, the pillars of medicine and takes into account personalized management of disease for a specific patient. Molecular phenotypes of neoplasms can be determined by molecular imaging with specific probes using positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), or optical methods, so that the treatment is specifically targeted against the tumor and its environment. To meet these demands, we need to define the targets, ligands, coupling and labeling chemistry, the most appropriate radionuclides, biodistribution modifiers, and finally select the right patients for the personalized treatment. THERANOSTICS of neuroendocrine tumors (NETs) using Ga-68 labeled tracers for diagnostics with positron emission tomography/ computed tomography (PET/CT), and using Lu-177 or other metallic radionuclides for radionuclide therapy by applying the same peptide proves that personalized radionuclide therapy today is already a fact and not a fiction.

Nursing benefits of using an automated injection system for ictal brain single photon emission computed tomography.

PubMed

Vonhofen, Geraldine; Evangelista, Tonya; Lordeon, Patricia

2012-04-01

The traditional method of administering radioactive isotopes to pediatric patients undergoing ictal brain single photon emission computed tomography testing has been by manual injections. This method presents certain challenges for nursing, including time requirements and safety risks. This quality improvement project discusses the implementation of an automated injection system for isotope administration and its impact on staffing, safety, and nursing satisfaction. It was conducted in an epilepsy monitoring unit at a large urban pediatric facility. Results of this project showed a decrease in the number of nurses exposed to radiation and improved nursing satisfaction with the use of the automated injection system. In addition, there was a decrease in the number of nursing hours required during ictal brain single photon emission computed tomography testing.

Compensation of optical heterogeneity-induced artifacts in fluorescence molecular tomography: theory and in vivo validation

NASA Astrophysics Data System (ADS)

Mohajerani, Pouyan; Adibi, Ali; Kempner, Joshua; Yared, Wael

2009-05-01

We present a method for reduction of image artifacts induced by the optical heterogeneities of tissue in fluorescence molecular tomography (FMT) through identification and compensation of image regions that evidence propagation of emission light through thin or low-absorption tunnels in tissue. The light tunneled as such contributes to the emission image as spurious components that might substantially overwhelm the desirable fluorescence emanating from the targeted lesions. The proposed method makes use of the strong spatial correlation between the emission and excitation images to estimate the tunneled components and yield a residual image that mainly consists of the signal due to the desirable fluorescence. This residual image is further refined using a coincidence mask constructed for each excitation-emission image pair. The coincidence mask is essentially a map of the ``hot spots'' that occur in both excitation and emission images, as such areas are often associated with tunneled emission. In vivo studies are performed on a human colon adenocarcinoma xenograft tumor model with subcutaneous tumors and a murine breast adenocarcinoma model with aggressive tumor cell metastasis and growth in the lungs. Results demonstrate significant improvements in the reconstructions achieved by the proposed method.

Hybrid SPECT/CT imaging in neurology.

PubMed

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

2014-01-01

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

Stomach metastasis of breast carcinoma mimicking primary gastric neoplasm on fluorodeoxy glucose-positron emission tomography-computed tomography.

PubMed

Joshi, Prathamesh; Lele, Vikram; Jain, Reetu; Khubchandani, Shaila; Sinhasan, Shraddha

2013-04-01

We present fluorodeoxy glucose positron emission tomography-computed tomography (FDG-PET/CT) findings in a case of breast carcinoma. The PET/CT findings in this case were suspicious of second primary neoplasm in the stomach. However, on endoscopic biopsy, the lesion was found to be stomach metastasis of breast carcinoma with estrogen receptor positivity. Stomach is a rare site of breast carcinoma metastasis. Our case suggests that it is difficult to distinguish a stomach metastasis of breast cancer from a primary gastric cancer on the basis of clinical and imaging features. However, this differential diagnosis must be kept in mind and it is important to make such distinction because of its implications on patient management.

Usefulness of Tc99m-mebrofenin Hepatobiliary Scintigraphy and Single Photon Emission Computed Tomography/Computed Tomography in the Diagnosis of Bronchobiliary Fistula.

PubMed

Parghane, Rahul Vithalrao; Phulsunga, Rohit Kumar; Gupta, Rajesh; Basher, Rajender Kumar; Bhattacharya, Anish; Mittal, Bhagwant Rai

2017-01-01

Bronchobiliary fistula (BBF), a rare complication of liver disease, is an abnormal communication between the biliary tract and bronchial tree. BBF may occur as a consequence of local liver infections such as hydatid or amebic disease, pyogenic liver abscess or trauma to the liver, obstruction of biliary tract, and tumor. As such management of liver disease with BBF is very difficult and often associated with a high rate of morbidity and mortality. Therefore, timely diagnosis of BBF is imperative. Hepatobiliary scintigraphy along with hybrid single photon emission computed tomography/computed tomography using Tc99m-mebrofenin is a very useful noninvasive imaging modality, in the diagnosis of BBF.

Usefulness of Tc99m-mebrofenin Hepatobiliary Scintigraphy and Single Photon Emission Computed Tomography/Computed Tomography in the Diagnosis of Bronchobiliary Fistula

PubMed Central

Parghane, Rahul Vithalrao; Phulsunga, Rohit Kumar; Gupta, Rajesh; Basher, Rajender Kumar; Bhattacharya, Anish; Mittal, Bhagwant Rai

2017-01-01

Bronchobiliary fistula (BBF), a rare complication of liver disease, is an abnormal communication between the biliary tract and bronchial tree. BBF may occur as a consequence of local liver infections such as hydatid or amebic disease, pyogenic liver abscess or trauma to the liver, obstruction of biliary tract, and tumor. As such management of liver disease with BBF is very difficult and often associated with a high rate of morbidity and mortality. Therefore, timely diagnosis of BBF is imperative. Hepatobiliary scintigraphy along with hybrid single photon emission computed tomography/computed tomography using Tc99m-mebrofenin is a very useful noninvasive imaging modality, in the diagnosis of BBF. PMID:29033682

Hemispheric encoding/retrieval asymmetry in episodic memory: positron emission tomography findings.

PubMed Central

Tulving, E; Kapur, S; Craik, F I; Moscovitch, M; Houle, S

1994-01-01

Data are reviewed from positron emission tomography studies of encoding and retrieval processes in episodic memory. These data suggest a hemispheric encoding/retrieval asymmetry model of prefrontal involvement in encoding and retrieval of episodic memory. According to this model, the left and right prefrontal lobes are part of an extensive neuronal network that subserves episodic remembering, but the two prefrontal hemispheres play different roles. Left prefrontal cortical regions are differentially more involved in retrieval of information from semantic memory and in simultaneously encoding novel aspects of the retrieved information into episodic memory. Right prefrontal cortical regions, on the other hand, are differentially more involved in episodic memory retrieval. PMID:8134342

Caffeine and human cerebral blood flow: A positron emission tomography study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cameron, O.G.; Modell, J.G.; Hariharan, M.

1990-01-01

Positron emission tomography (PET) was used to quantify the effect of caffeine on whole brain and regional cerebral blood flow (CBF) in humans. A mean dose of 250 mg of caffeine produced approximately a 30% decrease in whole brain CBF; regional differences in caffeine effect were not observed. Pre-caffeine CBF strongly influenced the magnitude of the caffeine-induced decrease. Caffeine decreased p{sub a}CO{sub 2} and increased systolic blood pressure significantly; the change in p{sub a}CO{sub 2} did not account for the change in CBF. Smaller increases in diastolic blood pressure, heart rate, plasma epinephrine and norepinephrine, and subjectively reported anxiety weremore » also observed.« less

Roche tomography of cataclysmic variables - VIII. The irradiated and spotted dwarf nova, SS Cygni

NASA Astrophysics Data System (ADS)

Hill, C. A.; Smith, Robert Connon; Hebb, L.; Szkody, P.

2017-12-01

We present the results of our spectroscopic study of the dwarf nova SS Cyg, using Roche tomography to map the stellar surface and derive the system parameters. Given that this technique takes into account the inhomogeneous brightness distribution on the surface of the secondary star, our derived parameters are (in principle) the most robust yet found for this system. Furthermore, our surface maps reveal that the secondary star is highly spotted, with strongly asymmetric irradiation on the inner hemisphere. Moreover, by constructing Doppler tomograms of several Balmer emission lines, we find strong asymmetric emission from the irradiated secondary star, and an asymmetric accretion disc that exhibits spiral structures.

Collimator-free photon tomography

DOEpatents

Dilmanian, F. Avraham; Barbour, Randall L.

1998-10-06

A method of uncollimated single photon emission computed tomography includes administering a radioisotope to a patient for producing gamma ray photons from a source inside the patient. Emissivity of the photons is measured externally of the patient with an uncollimated gamma camera at a plurality of measurement positions surrounding the patient for obtaining corresponding energy spectrums thereat. Photon emissivity at the plurality of measurement positions is predicted using an initial prediction of an image of the source. The predicted and measured photon emissivities are compared to obtain differences therebetween. Prediction and comparison is iterated by updating the image prediction until the differences are below a threshold for obtaining a final prediction of the source image.

Comparison of whole body magnetic resonance imaging (WBMRI) to whole body computed tomography (WBCT) or 18F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) in patients with myeloma: Systematic review of diagnostic performance.

PubMed

Gariani, Joanna; Westerland, Olwen; Natas, Sarah; Verma, Hema; Cook, Gary; Goh, Vicky

2018-04-01

To undertake a systematic review to determine the diagnostic performance of whole body MRI (WBMRI) including diffusion weighted sequences (DWI) compared to whole body computed tomography (WBCT) or 18 F-fluorodeoxyglucose positron emission tomography/CT ( 18 F-FDG PET/CT) in patients with myeloma. Two researchers searched the primary literature independently for WBMRI studies of myeloma. Data were extracted focusing on the diagnostic ability of WBMRI versus WBCT and 18 F-FDG PET/CT. Meta-analysis was intended. 6 of 2857 articles were eligible that included 147 patients, published from 2008 to 2016. Studies were heterogeneous including both newly diagnosed & relapsed patients. All were single centre studies. Four of the six studies (66.7%) accrued prospectively and 5/6 (83.3%, 3 prospective) included WBMRI and 18 F-FDG PET/CT. Three of seven (42.9%) included DWI. The lack of an independent reference standard for individual lesions was noted in 5/6 (83.3%) studies. Studies reported that WBMRI detected more lesions than 18 F-FDG PET/CT (sensitivity 68-100% versus 47-100%) but was less specific (specificity 37-83% versus 62-85.7%). No paper assessed impact on management. Studies were heterogeneous, the majority lacking an independent reference standard. Future prospective trials should address these limitations and assess the impact of WBMRI on management. Copyright © 2018. Published by Elsevier B.V.

The metabolic basis of cognitive insight in psychosis: A positron emission tomography study

PubMed Central

Paoli, Riccardo A.; Cigliobianco, Michela; Prunas, Cecilia; Zugno, Elisa; Bottinelli, Francesca; Brambilla, Paolo; Altamura, A. Carlo

2017-01-01

The purpose of this study was to investigate the relationship between cognitive insight and cerebral metabolism in patients suffering from psychosis. The Beck Cognitive Insight Scale (BCIS) was administered to 63 patients with psychosis undergoing Positron Emission Tomography investigation. The sample was divided into two groups considering the BCIS score. Data were analyzed using Statistical Parametric Mapping. Results: patients with low insight, compared to those with high insight, showed decreased metabolism in the right fusiform gyrus, left precuneus, superior temporal gyrus and insula bilaterally, as well as increased metabolism in the left orbito-frontal gyrus (all p<0.005). Our results suggest that reduced posterior (occipito-temporo-insulo-parietal) and increased anterior (orbitofrontal) cerebral metabolism may sustain low cognitive insight in psychosis. PMID:28414766

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

A Phase 2 Study of 16α-[18F]-fluoro-17β-estradiol Positron Emission Tomography (FES-PET) as a Marker of Hormone Sensitivity in Metastatic Breast Cancer (MBC)

PubMed Central

Peterson, Lanell M.; Kurland, Brenda F.; Schubert, Erin K.; Link, Jeanne M.; Gadi, V.K.; Specht, Jennifer M.; Eary, Janet F.; Porter, Peggy; Shankar, Lalitha K.; Mankoff, David A.; Linden, Hannah M.

2014-01-01

Purpose 16α-[18F]-fluoro-17β-estradiol positron emission tomography (FES-PET) quantifies estrogen receptor (ER) expression in tumors and may provide diagnostic benefit. Procedures Women with newly diagnosed metastatic breast cancer (MBC) from an ER-positive primary tumor were imaged before starting endocrine therapy. FES uptake was evaluated qualitatively and quantitatively, and associated with response and with ER expression. Results Nineteen patients underwent FES imaging. Fifteen had a biopsy of a metastasis and 15 were evaluable for response. Five patients had quantitatively low FES uptake, six had at least one site of qualitatively FES-negative disease. All patients with an ER-negative biopsy had both low uptake and at least one site of FES-negative disease. Of response-evaluable patients, 2/2 with low FES standard uptake value tumors had progressive disease within 6 months, as did 2/3 with qualitatively FES-negative tumors. Conclusions Low/absent FES uptake correlates with lack of ER expression. FES-positron emission tomography can help identify patients with endocrine resistant disease and safely measures ER in MBC. PMID:24170452

Melorheostosis associated with peripheral form spondyloarthropathy: new image with 18-fluoride positron emission tomoscintigraphy coupled to computed tomography

PubMed Central

Hassani, Hakim; Slama, Jérôme; Hayem, Gilles; Ben Ali, Khadija; Sarda-Mantel, Laure; Burg, Samuel; Le Guludec, Dominique

2012-01-01

Melorheostosis is a rare benign bone pathology which can be responsible for incapacitating pain and bone deformations. Its imaging abnormalities are often typical. We describe here the case of a patient with melorheostosis involving the lower limbs, associated with a peripheral form of inflammatory spondyloarthropathy, who underwent 18FNa positron emission tomography coupled to a computed tomography scan. Our objective is to present this new image, to show the value of this new modality and emphasize its advantages compared to the 99mTechnetium bone scan. PMID:27790007

Comprehensive Digital Imaging Network Project At Georgetown University Hospital

NASA Astrophysics Data System (ADS)

Mun, Seong K.; Stauffer, Douglas; Zeman, Robert; Benson, Harold; Wang, Paul; Allman, Robert

1987-10-01

The radiology practice is going through rapid changes due to the introduction of state-of-the-art computed based technologies. For the last twenty years we have witnessed the introduction of many new medical diagnostic imaging systems such as x-ray computed tomo-graphy, digital subtraction angiography (DSA), computerized nuclear medicine, single pho-ton emission computed tomography (SPECT), positron emission tomography (PET) and more re-cently, computerized digital radiography and nuclear magnetic resonance imaging (MRI). Other than the imaging systems, there has been a steady introduction of computed based information systems for radiology departments and hospitals.

Clinical Relevance of 18F-Sodium Fluoride Positron-Emission Tomography in Noninvasive Identification of High-Risk Plaque in Patients With Coronary Artery Disease.

PubMed

Lee, Joo Myung; Bang, Ji-In; Koo, Bon-Kwon; Hwang, Doyeon; Park, Jonghanne; Zhang, Jinlong; Yaliang, Tong; Suh, Minseok; Paeng, Jin Chul; Shiono, Yasutsugu; Kubo, Takashi; Akasaka, Takashi

2017-11-01

18 F-sodium fluoride ( 18 F-NaF) positron-emission tomography has been introduced as a potential noninvasive imaging tool to identify plaques with high-risk characteristics in patients with coronary artery disease. We sought to evaluate the clinical relevance of 18 F-NaF uptake using optical coherence tomography (OCT), intravascular ultrasound (IVUS), and coronary computed tomography angiography in patients with coronary artery disease. The target population consisted of 51 prospectively enrolled patients (93 stenoses) who underwent 18 F-NaF positron-emission tomography before invasive coronary angiography. 18 F-NaF uptake was compared with IVUS- and OCT-derived plaque characteristics. In the coronary computed tomography angiography subgroup (46 lesions), qualitative lesion characteristics were compared between 18 F-NaF-positive and 18 F-NaF-negative plaques using adverse plaque characteristics. The plaques with 18 F-NaF uptake showed significantly higher plaque burden, more frequent posterior attenuation and positive remodeling in IVUS, and significantly higher maximum lipid arc and more frequent microvessels in OCT (all P <0.05). There were no differences in minimum lumen area and area of calcium between 18 F-NaF-positive and 18 F-NaF-negative lesions. Among 51 lesions with 18 F-NaF-positive uptake, 48 lesions (94.1%) had at least one of high-risk characteristics. The 18 F-NaF tissue-to-background ratio in plaques with high-risk characteristics was significantly higher than in those without (1.09 [95% confidence interval, 0.85-1.34] versus 0.62 [95% confidence interval, 0.42-0.82], P <0.001 for IVUS definition; 0.76 [95% confidence interval, 0.54-0.98] versus 0.42 [95% confidence interval, 0.21-0.62], P =0.014 for OCT definition). Among the 15 lesions that met both IVUS- and OCT-defined criteria for high-risk plaque, 14 (93.3%) showed 18 F-NaF-positive uptake. There was no difference in the prevalence of plaques with any adverse plaque characteristics between 18 F-NaF-positive and 18 F-NaF-negative plaques in the coronary computed tomography angiography subgroup (85.2% versus 78.9%; P =0.583). This study's results suggest that 18 F-NaF positron-emission tomography can be a useful noninvasive diagnostic tool to identify and localize plaque with high-risk characteristics. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02388412. © 2017 American Heart Association, Inc.

Impact of Single-Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) and Positron Emission Tomography/Computed Tomography (PET/CT) in the Diagnosis of Traumatic Brain Injury (TBI): Case Report.

PubMed

Molina-Vicenty, Irma L; Santiago-Sánchez, Michelaldemar; Vélez-Miró, Iván; Motta-Valencia, Keryl

2016-09-01

Traumatic brain injury (TBI) is defined as damage to the brain resulting from an external force. TBI, a global leading cause of death and disability, is associated with serious social, economic, and health problems. In cases of mild-to-moderate brain damage, conventional anatomical imaging modalities may or may not detect the cascade of metabolic changes that have occurred or are occurring at the intracellular level. Functional nuclear medicine imaging and neurophysiological parameters can be used to characterize brain damage, as the former provides direct visualization of brain function, even in the absence of overt behavioral manifestations or anatomical findings. We report the case of a 30-year-old Hispanic male veteran who, after 2 traumatic brain injury events, developed cognitive and neuropsychological problems with no clear etiology in the presence of negative computed tomography (CT) findings.

[Novelties in diagnostics and treatment of prostate cancer].

PubMed

Riesz, Péter; Nyírádi, Péter

2016-03-13

Similarly to earlier years, a vast majority of novel findings were published on prostate cancer, which is the most common urological cancer. Clinical trials with long-term follow-up and promising observational studies were published. In this paper the author reviews the relevant novelties including the diagnostic use of magnetic resonance imaging and positron emission tomography/computed tomography as well as active surveillance, cytoreductive prostatectomy and medical treatment.

Novel methodology for labelling mesoporous silica nanoparticles using the 18F isotope and their in vivo biodistribution by positron emission tomography

NASA Astrophysics Data System (ADS)

Rojas, Santiago; Gispert, Juan Domingo; Menchón, Cristina; Baldoví, Herme G.; Buaki-Sogo, Mireia; Rocha, Milagros; Abad, Sergio; Victor, Victor Manuel; García, Hermenegildo; Herance, José Raúl

2015-03-01

Nanoparticles have been proposed for several biomedical applications due to their potential as drug carriers, diagnostic and therapeutic agents. However, only a few of them have been approved for their use in humans. In order to gauge the potential applicability of a specific type of nanoparticle, in vivo biodistribution studies to characterize their pharmacokinetic properties are essential. In this regard, mesoporous silica nanoparticles (30-130 nm) have been functionalized with amino groups in order to react with N-succinimidyl 4-[18F]fluorobenzoate and thus anchor the 18F positron emission isotope by using a novel and easy labelling strategy. In vivo biodistribution was characterized in mice after intravenous administration of radiolabelled nanoparticles by positron emission tomography. Our results indicated that radiolabelled mesoporous silica nanoparticles were excreted into bile and urine and accumulated mainly in the organs of the reticuloendothelial system and lungs.

Role of radionuclide imaging for diagnosis of device and prosthetic valve infections

PubMed Central

Sarrazin, Jean-François; Philippon, François; Trottier, Mikaël; Tessier, Michel

2016-01-01

Cardiovascular implantable electronic device (CIED) infection and prosthetic valve endocarditis (PVE) remain a diagnostic challenge. Cardiac imaging plays an important role in the diagnosis and management of patients with CIED infection or PVE. Over the past few years, cardiac radionuclide imaging has gained a key role in the diagnosis of these patients, and in assessing the need for surgery, mainly in the most difficult cases. Both 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and radiolabelled white blood cell single-photon emission computed tomography/computed tomography (WBC SPECT/CT) have been studied in these situations. In their 2015 guidelines for the management of infective endocarditis, the European Society of Cardiology incorporated cardiac nuclear imaging as part of their diagnostic algorithm for PVE, but not CIED infection since the data were judged insufficient at the moment. This article reviews the actual knowledge and recent studies on the use of 18F-FDG PET/CT and WBC SPECT/CT in the context of CIED infection and PVE, and describes the technical aspects of cardiac radionuclide imaging. It also discusses their accepted and potential indications for the diagnosis and management of CIED infection and PVE, the limitations of these tests, and potential areas of future research. PMID:27721936

Mind Over Matter: Methamphetamine

MedlinePlus

... If a Person Uses Methamphetamine for a Long Time? Scientists are using brain imaging techniques, like positron emission tomography (called PET for short), to study the brains of human Methamphetamine users. They have ...

Optimal Adenosine Stress for Maximum Stress Perfusion, Coronary Flow Reserve, and Pixel Distribution of Coronary Flow Capacity by Kolmogorov-Smirnov Analysis.

PubMed

Kitkungvan, Danai; Lai, Dejian; Zhu, Hongjian; Roby, Amanda E; Johnson, Nils P; Steptoe, Derek D; Patel, Monica B; Kirkeeide, Richard; Gould, K Lance

2017-02-01

Different adenosine stress imaging protocols have not been systemically validated for absolute myocardial perfusion and coronary flow reserve (CFR) by positron emission tomography, where submaximal stress precludes assessing physiological severity of coronary artery disease. In 127 volunteers, serial rest-stress positron emission tomography scans using rubidium-82 with various adenosine infusion protocols identified (1) the protocol with maximum stress perfusion and CFR, (2) test-retest precision in same subject, (3) stress perfusion and CFR after adenosine compared with dipyridamole, (4) heterogeneity of coronary flow capacity combining stress perfusion and CFR, and (5) potential relevance for patients with risk factors or coronary artery disease. The adenosine 6-minute infusion with rubidium-82 injection at 3 minutes caused CFR that was significantly 15.7% higher than the 4-minute adenosine infusion with rubidium-82 injection at 2 minutes and significantly more homogeneous by Kolmogorov-Smirnov analysis for histograms of 1344 pixel range of perfusion in paired positron emission tomographies. In a coronary artery disease cohort separate from volunteers of this study, compared with the 3/6-minute protocol, the 2/4-minute adenosine protocol would potentially have changed 332 of 1732 (19%) positron emission tomographies at low-risk physiological severity CFR ≥2.3 to CFR <2.0, thereby implying high-risk quantitative severity potentially appropriate for interventions but because of suboptimal stress of the 2/4 protocol in some patients. The 6-minute adenosine infusion with rubidium-82 activation at 3 minutes produced CFR that averaged 15.7% higher than that in the 2/4-minute protocol, thereby potentially providing essential information for personalized management in some patients. © 2017 American Heart Association, Inc.

Positron emission tomography/magnetic resonance hybrid scanner imaging of cerebral blood flow using 15O-water positron emission tomography and arterial spin labeling magnetic resonance imaging in newborn piglets

PubMed Central

Andersen, Julie B; Henning, William S; Lindberg, Ulrich; Ladefoged, Claes N; Højgaard, Liselotte; Greisen, Gorm; Law, Ian

2015-01-01

Abnormality in cerebral blood flow (CBF) distribution can lead to hypoxic–ischemic cerebral damage in newborn infants. The aim of the study was to investigate minimally invasive approaches to measure CBF by comparing simultaneous 15O-water positron emission tomography (PET) and single TI pulsed arterial spin labeling (ASL) magnetic resonance imaging (MR) on a hybrid PET/MR in seven newborn piglets. Positron emission tomography was performed with IV injections of 20 MBq and 100 MBq 15O-water to confirm CBF reliability at low activity. Cerebral blood flow was quantified using a one-tissue-compartment-model using two input functions: an arterial input function (AIF) or an image-derived input function (IDIF). The mean global CBF (95% CI) PET-AIF, PET-IDIF, and ASL at baseline were 27 (23; 32), 34 (31; 37), and 27 (22; 32) mL/100 g per minute, respectively. At acetazolamide stimulus, PET-AIF, PET-IDIF, and ASL were 64 (55; 74), 76 (70; 83) and 79 (67; 92) mL/100 g per minute, respectively. At baseline, differences between PET-AIF, PET-IDIF, and ASL were 22% (P<0.0001) and −0.7% (P=0.9). At acetazolamide, differences between PET-AIF, PET-IDIF, and ASL were 19% (P=0.001) and 24% (P=0.0003). In conclusion, PET-IDIF overestimated CBF. Injected activity of 20 MBq 15O-water had acceptable concordance with 100 MBq, without compromising image quality. Single TI ASL was questionable for regional CBF measurements. Global ASL CBF and PET CBF were congruent during baseline but not during hyperperfusion. PMID:26058699

Dental optical tomography with upconversion nanoparticles—a feasibility study

PubMed Central

Long, Feixiao; Intes, Xavier

2017-01-01

Abstract. Upconversion nanoparticles (UCNPs) have the unique ability to emit multiple colors upon excitation by near-infrared (NIR) light. Herein, we investigate the potential use of UCNPs as contrast agents for dental optical tomography, with a focus on monitoring the status of fillings after dental restoration. The potential of performing tomographic imaging using UCNP emission of visible or NIR light is established. This in silico and ex vivo study paves the way toward employing UCNPs as theranostic agents for dental applications. PMID:28586852

Dental optical tomography with upconversion nanoparticles—a feasibility study

NASA Astrophysics Data System (ADS)

Long, Feixiao; Intes, Xavier

2017-06-01

Upconversion nanoparticles (UCNPs) have the unique ability to emit multiple colors upon excitation by near-infrared (NIR) light. Herein, we investigate the potential use of UCNPs as contrast agents for dental optical tomography, with a focus on monitoring the status of fillings after dental restoration. The potential of performing tomographic imaging using UCNP emission of visible or NIR light is established. This in silico and ex vivo study paves the way toward employing UCNPs as theranostic agents for dental applications.

Dental optical tomography with upconversion nanoparticles-a feasibility study.

PubMed

Long, Feixiao; Intes, Xavier

2017-06-01

Upconversion nanoparticles (UCNPs) have the unique ability to emit multiple colors upon excitation by near-infrared (NIR) light. Herein, we investigate the potential use of UCNPs as contrast agents for dental optical tomography, with a focus on monitoring the status of fillings after dental restoration. The potential of performing tomographic imaging using UCNP emission of visible or NIR light is established. This in silico and ex vivo study paves the way toward employing UCNPs as theranostic agents for dental applications.

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 asymmetry of radiotracer uptake. PET is helpful in targeting diagnostic interventions, characterizing disease extent, assessing nodal involvement, and treatment efficacy for syphilis.

Relative Value of Restaging MRI, CT, and FDG-PET Scan After Preoperative Chemoradiation for Rectal Cancer.

PubMed

Schneider, Daniel A; Akhurst, Timothy J; Ngan, Samuel Y; Warrier, Satish K; Michael, Michael; Lynch, Andrew C; Te Marvelde, Luc; Heriot, Alexander G

2016-03-01

Management of rectal cancer has become multidisciplinary and is driven by the stage of the disease, with increased focus on restaging rectal cancer after neoadjuvant therapy. The purpose of this study was to assess the relative impact of restaging after preoperative chemoradiation with FDG-PET scan, CT, and MRI in the management of patients with rectal cancer. This was a retrospective study from a single institution. This study was conducted at a tertiary cancer center. A total of 199 patients met the inclusion criteria: patients with rectal adenocarcinoma; staged with positron emission tomography, CT, and MRI; T2 to T4, N0 to N2, M0 to M1; treated with neoadjuvant chemoradiation 50.4 Gy and infusional 5-fluorouracil; and restaged 4 weeks after chemoradiation before surgery between 2003 and 2013. Comparisons of the tumor stage among different imaging modalities before and after neoadjuvant chemoradiation were performed. The impact of restaging on the management plan was assessed. The stage at presentation was T2, 8.04%; T3, 65.33%; T4, 26.63%; N0, 17.09%; N1, 47.74%; N2, 34.67%; M0, 81.91%; and M1, 18.09%. Changes in disease stage postneoadjuvant chemoradiation were observed in 99 patients (50%). The management plans of 29 patients (15%) were changed. The impact of each restaging modality on management for all of the patients was positron emission tomography, 11%; CT, 4%; and MRI, 4%. In patients with metastatic disease at primary staging, the relative impact of each restaging modality in changing management was positron emission tomography, 32%; CT, 18%; and MRI, 6%. This study was limited by its single-center and retrospective design. Operations were performed 4 weeks after restaging. Changes in the extent of disease after long-course chemoradiotherapy result in changes of management in a significant percentage of patients. Positron emission tomography has the most significant impact in the change of management overall, and its use in restaging advanced rectal cancer should be further explored.

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.

Direct Test for Neuroinflammation with [11C]DAP-713-PET Scanning

DTIC Science & Technology

2015-10-01

individuals suffering from the Gulf War Illness (GWI). We are using quantitative positron emission tomography (PET) using [11C]DPA-713 (DPA). DPA...suffering from the Gulf War Illness (GWI). We are using quantitative positron emission tomography (PET) using [11C]DPA-713 (DPA). DPA binds to the... Resistant Prostate Cancer Time commitments: 0.12 calendar months Supporting Agency: CDMRP Grants Contact: TBD PI: Denmeade Co-Investigator

Progress on the diagnosis and evaluation of brain tumors

PubMed Central

Gao, Huile

2013-01-01

Abstract Brain tumors are one of the most challenging disorders encountered, and early and accurate diagnosis is essential for the management and treatment of these tumors. In this article, diagnostic modalities including single-photon emission computed tomography, positron emission tomography, magnetic resonance imaging, and optical imaging are reviewed. We mainly focus on the newly emerging, specific imaging probes, and their potential use in animal models and clinical settings. PMID:24334439

Preamputation evaluation of lower-limb skeletal muscle perfusion with H(2) (15)O positron emission tomography.

PubMed

Scremin, Oscar U; Figoni, Stephen F; Norman, Keith; Scremin, A M Erika; Kunkel, Charles F; Opava-Rutter, Dorene; Schmitter, Eric D; Bert, Alberto; Mandelkern, Mark

2010-06-01

To establish whether muscle blood flow (MBF) measurements with O-water positron emission tomography could reliably identify patients with critical limb ischemia and detect and quantify a distal deficit in skeletal MBF in these cases. O-water positron emission tomography scans were performed at rest or during unloaded ankle plantar and dorsiflexion exercise of the diseased leg in 17 subjects with leg ischemia or on a randomly selected leg of 18 age-matched healthy control subjects. TcPO2 was evaluated with Novametrix monitors and perfusion of skin topically heated to 44 degrees C and adjacent nonheated areas with a Moor Instruments laser Doppler imaging scanner. The enhancement of MBF induced by exercise was significantly lower in ischemic than in normal legs, and the sensitivity and specificity of this phenomenon were similar to those of laser Doppler imaging or TcPO2 in identifying ischemia subjects. In addition, the exercise MBF deficit was predominant at the distal-leg levels, indicating the ability of the technique to help determine the correct level of amputation. Skeletal MBF of legs with severe ischemia can be detected accurately with O-water positron emission tomography and could add valuable information about viability of skeletal muscle in the residual limb when deciding the level of an amputation.

Collimator-free photon tomography

DOEpatents

Dilmanian, F.A.; Barbour, R.L.

1998-10-06

A method of uncollimated single photon emission computed tomography includes administering a radioisotope to a patient for producing gamma ray photons from a source inside the patient. Emissivity of the photons is measured externally of the patient with an uncollimated gamma camera at a plurality of measurement positions surrounding the patient for obtaining corresponding energy spectrums thereat. Photon emissivity at the plurality of measurement positions is predicted using an initial prediction of an image of the source. The predicted and measured photon emissivities are compared to obtain differences therebetween. Prediction and comparison is iterated by updating the image prediction until the differences are below a threshold for obtaining a final prediction of the source image. 6 figs.

Development of a Simple Image Processing Application that Makes Abdominopelvic Tumor Visible on Positron Emission Tomography/Computed Tomography Image.

PubMed

Pandey, Anil Kumar; Saroha, Kartik; Sharma, Param Dev; Patel, Chetan; Bal, Chandrashekhar; Kumar, Rakesh

2017-01-01

In this study, we have developed a simple image processing application in MATLAB that uses suprathreshold stochastic resonance (SSR) and helps the user to visualize abdominopelvic tumor on the exported prediuretic positron emission tomography/computed tomography (PET/CT) images. A brainstorming session was conducted for requirement analysis for the program. It was decided that program should load the screen captured PET/CT images and then produces output images in a window with a slider control that should enable the user to view the best image that visualizes the tumor, if present. The program was implemented on personal computer using Microsoft Windows and MATLAB R2013b. The program has option for the user to select the input image. For the selected image, it displays output images generated using SSR in a separate window having a slider control. The slider control enables the user to view images and select one which seems to provide the best visualization of the area(s) of interest. The developed application enables the user to select, process, and view output images in the process of utilizing SSR to detect the presence of abdominopelvic tumor on prediuretic PET/CT image.

Preoperative predictive model of cervical lymph node metastasis combining fluorine-18 fluorodeoxyglucose positron-emission tomography/computerized tomography findings and clinical factors in patients with oral or oropharyngeal squamous cell carcinoma.

PubMed

Mochizuki, Yumi; Omura, Ken; Nakamura, Shin; Harada, Hiroyuki; Shibuya, Hitoshi; Kurabayashi, Toru

2012-02-01

This study aimed to construct a preoperative predictive model of cervical lymph node metastasis using fluorine-18 fluorodeoxyglucose positron-emission tomography/computerized tomography ((18)F-FDG PET/CT) findings in patients with oral or oropharyngeal squamous cell carcinoma (SCC). Forty-nine such patients undergoing preoperative (18)F-FDG PET/CT and neck dissection or lymph node biopsy were enrolled. Retrospective comparisons with spatial correlation between PET/CT and the anatomical sites based on histopathological examinations of surgical specimens were performed. We calculated a logistic regression model, including the SUVmax-related variable. When using the optimal cutoff point criterion of probabilities calculated from the model that included either clinical factors and delayed-phase SUVmax ≥0.087 or clinical factors and maximum standardized uptake (SUV) increasing rate (SUV-IR) ≥ 0.100, it significantly increased the sensitivity, specificity, and accuracy (87.5%, 65.7%, and 75.2%, respectively). The use of predictive models that include clinical factors and delayed-phase SUVmax and SUV-IR improve preoperative nodal diagnosis. Copyright © 2012 Elsevier Inc. All rights reserved.

Implementation and applications of dual-modality imaging

NASA Astrophysics Data System (ADS)

Hasegawa, Bruce H.; Barber, William C.; Funk, Tobias; Hwang, Andrew B.; Taylor, Carmen; Sun, Mingshan; Seo, Youngho

2004-06-01

In medical diagnosis, functional or physiological data can be acquired using radionuclide imaging with positron emission tomography or with single-photon emission computed tomography. However, anatomical or structural data can be acquired using X-ray computed tomography. In dual-modality imaging, both radionuclide and X-ray detectors are incorporated in an imaging system to allow both functional and structural data to be acquired in a single procedure without removing the patient from the imaging system. In a clinical setting, dual-modality imaging systems commonly are used to localize radiopharmaceutical uptake with respect to the patient's anatomy. This helps the clinician to differentiate disease from regions of normal radiopharmaceutical accumulation, to improve diagnosis or cancer staging, or to facilitate planning for radiation therapy or surgery. While initial applications of dual-modality imaging were developed for clinical imaging on humans, it now is recognized that these systems have potentially important applications for imaging small animals involved in experimental studies including basic investigations of mammalian biology and development of new pharmaceuticals for diagnosis or treatment of disease.

Contemporary imaging of mild TBI: the journey toward diffusion tensor imaging to assess neuronal damage.

PubMed

Fox, W Christopher; Park, Min S; Belverud, Shawn; Klugh, Arnett; Rivet, Dennis; Tomlin, Jeffrey M

2013-04-01

To follow the progression of neuroimaging as a means of non-invasive evaluation of mild traumatic brain injury (mTBI) in order to provide recommendations based on reproducible, defined imaging findings. A comprehensive literature review and analysis of contemporary published articles was performed to study the progression of neuroimaging findings as a non-invasive 'biomarker' for mTBI. Multiple imaging modalities exist to support the evaluation of patients with mTBI, including ultrasound (US), computed tomography (CT), single photon emission computed tomography (SPECT), positron emission tomography (PET), and magnetic resonance imaging (MRI). These techniques continue to evolve with the development of fractional anisotropy (FA), fiber tractography (FT), and diffusion tensor imaging (DTI). Modern imaging techniques, when applied in the appropriate clinical setting, may serve as a valuable tool for diagnosis and management of patients with mTBI. An understanding of modern neuroanatomical imaging will enhance our ability to analyse injury and recognize the manifestations of mTBI.

Cardiac PET/CT for the Evaluation of Known or Suspected Coronary Artery Disease

PubMed Central

Murthy, Venkatesh L.

2011-01-01

Positron emission tomography (PET) is increasingly being applied in the evaluation of myocardial perfusion. Cardiac PET can be performed with an increasing variety of cyclotron- and generator-produced radiotracers. Compared with single photon emission computed tomography, PET offers lower radiation exposure, fewer artifacts, improved spatial resolution, and, most important, improved diagnostic performance. With its capacity to quantify rest–peak stress left ventricular systolic function as well as coronary flow reserve, PET is superior to other methods for the detection of multivessel coronary artery disease and, potentially, for risk stratification. Coronary artery calcium scoring may be included for further risk stratification in patients with normal perfusion imaging findings. Furthermore, PET allows quantification of absolute myocardial perfusion, which also carries substantial prognostic value. Hybrid PET–computed tomography scanners allow functional evaluation of myocardial perfusion combined with anatomic characterization of the epicardial coronary arteries, thereby offering great potential for both diagnosis and management. Additional studies to further validate the prognostic value and cost effectiveness of PET are warranted. © RSNA, 2011 PMID:21918042

Tissue-like phantoms

DOEpatents

Frangioni, John V.; De Grand, Alec M.

2007-10-30

The invention is based, in part, on the discovery that by combining certain components one can generate a tissue-like phantom that mimics any desired tissue, is simple and inexpensive to prepare, and is stable over many weeks or months. In addition, new multi-modal imaging objects (e.g., beads) can be inserted into the phantoms to mimic tissue pathologies, such as cancer, or merely to serve as calibration standards. These objects can be imaged using one, two, or more (e.g., four) different imaging modalities (e.g., x-ray computed tomography (CT), positron emission tomography (PET), single photon emission computed tomography (SPECT), and near-infrared (NIR) fluorescence) simultaneously.

The role of positron emission tomography in the diagnosis, staging and response assessment of non-small cell lung cancer

PubMed Central

Ali, Jason M.; Tasker, Angela; Peryt, Adam; Aresu, Giuseppe; Coonar, Aman S.

2018-01-01

Lung cancer is a common disease and the leading cause of cancer-related mortality, with non-small cell lung cancer (NSCLC) accounting for the majority of cases. Following diagnosis of lung cancer, accurate staging is essential to guide clinical management and inform prognosis. Positron emission tomography (PET) in conjunction with computed tomography (CT)—as PET-CT has developed as an important tool in the multi-disciplinary management of lung cancer. This article will review the current evidence for the role of 18F-fluorodeoxyglucose (FDG) PET-CT in NSCLC diagnosis, staging, response assessment and follow up. PMID:29666818

Review of cardiovascular imaging in the Journal of Nuclear Cardiology in 2017. Part 2 of 2: Myocardial perfusion imaging.

PubMed

Hage, Fadi G; AlJaroudi, Wael A

2018-04-16

In 2017, the Journal of Nuclear Cardiology published many high-quality articles. In this review, we will summarize a selection of these articles to provide a concise review of the main advancements that have recently occurred in the field. In the first article of this 2-part series, we focused on publications dealing with positron emission tomography, computed tomography, and magnetic resonance. This review will place emphasis on myocardial perfusion imaging using single-photon emission computed tomography summarizing advances in the field including prognosis, safety and tolerability, the impact of imaging on management, and the use of novel imaging protocols.

Update on advances in molecular PET in urological oncology

PubMed Central

Yamamoto, Shingo; Fukushima, Kazuhito; Minamimoto, Ryogo; Kamai, Takao; Jadvar, Hossein

2017-01-01

Integrated positron emission tomography/computed tomography (PET/CT) with 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) has emerged as a powerful tool for the combined metabolic and anatomic evaluation of many cancers. In urological oncology, however, the use of 18F-FDG has been limited by a generally low tumor uptake, and physiological excretion of FDG through the urinary system. 18F-FDG PET/CT is useful when applied to specific indications in selected patients with urological malignancy. New radiotracers and positron emission tomography/magnetic resonance imaging (PET/MRI) are expected to further improve the performance of PET in uro-oncology. PMID:27222021

The role of Fluorine-18-Fluorodeoxyglucose positron emission tomography in staging and restaging of patients with osteosarcoma

PubMed Central

Quartuccio, Natale; Treglia, Giorgio; Salsano, Marco; Mattoli, Maria Vittoria; Muoio, Barbara; Piccardo, Arnoldo; Lopci, Egesta; Cistaro, Angelina

2013-01-01

Background The objective of this study is to systematically review the role of positron emission tomography (PET) and PET/computed tomography (PET/CT) with Fluorine-18-Fluorodeoxyglucose (FDG) in patients with osteosarcoma (OS). Methods A comprehensive literature search of published studies through October 10th, 2012 in PubMed/MEDLINE, Embase and Scopus databases regarding whole-body FDG-PET and FDG-PET/CT in patients with OS was performed. Results We identified 13 studies including 289 patients with OS. With regard to the staging and restaging of OS, the diagnostic performance of FDG-PET and PET/CT seem to be high; FDG-PET and PET/CT seem to be superior to bone scintigraphy and conventional imaging methods in detecting bone metastases; conversely, spiral CT seems to be superior to FDG-PET in detecting pulmonary metastases from OS Conclusions Metabolic imaging may provide additional information in the evaluation of OS patients. The combination of FDG-PET or FDG-PET/CT with conventional imaging methods seems to be a valuable tool in the staging and restaging of OS and may have a relevant impact on the treatment planning. PMID:23801904

Molecular Imaging of Hydrolytic Enzymes Using PET and SPECT

PubMed Central

Rempel, Brian P.; Price, Eric W.

2017-01-01

Hydrolytic enzymes are a large class of biological catalysts that play a vital role in a plethora of critical biochemical processes required to maintain human health. However, the expression and/or activity of these important enzymes can change in many different diseases and therefore represent exciting targets for the development of positron emission tomography (PET) and single-photon emission computed tomography (SPECT) radiotracers. This review focuses on recently reported radiolabeled substrates, reversible inhibitors, and irreversible inhibitors investigated as PET and SPECT tracers for imaging hydrolytic enzymes. By learning from the most successful examples of tracer development for hydrolytic enzymes, it appears that an early focus on careful enzyme kinetics and cell-based studies are key factors for identifying potentially useful new molecular imaging agents. PMID:28927325

PET scan-positive cat scratch disease in a patient with T cell lymphoblastic lymphoma.

PubMed

Jeong, Woondong; Seiter, Karen; Strauchen, James; Rafael, Theodore; Lau, Har Chi; Breakstone, Beth; Ahmed, Tauseef; Liu, Delong

2005-05-01

In patients who have history of lymphoma, a positive positron emission tomography (PET) scan is frequently considered as good evidence for relapse and/or persistent disease. Thus, lymph node biopsy is not always done to confirm the diagnosis of relapse or refractory lymphoma before a patient is subjected to further chemotherapy. We report a case of patient with history of T cell lymphoblastic lymphoma who presented again with inguinal lymphadenopathy and positive study on positron emission tomography suggestive of lymphoma relapse. This was pathologically proven to be cat scratch disease. This case suggests that in the immunocompromised patients who had history of lymphoma, infectious etiology should be ruled out for PET scan-positive lymphadenopathy.

Molecular Imaging of Hydrolytic Enzymes Using PET and SPECT.

PubMed

Rempel, Brian P; Price, Eric W; Phenix, Christopher P

2017-01-01

Hydrolytic enzymes are a large class of biological catalysts that play a vital role in a plethora of critical biochemical processes required to maintain human health. However, the expression and/or activity of these important enzymes can change in many different diseases and therefore represent exciting targets for the development of positron emission tomography (PET) and single-photon emission computed tomography (SPECT) radiotracers. This review focuses on recently reported radiolabeled substrates, reversible inhibitors, and irreversible inhibitors investigated as PET and SPECT tracers for imaging hydrolytic enzymes. By learning from the most successful examples of tracer development for hydrolytic enzymes, it appears that an early focus on careful enzyme kinetics and cell-based studies are key factors for identifying potentially useful new molecular imaging agents.

Quality control of positron emission tomography radiopharmaceuticals: An institutional experience.

PubMed

Shukla, Jaya; Vatsa, Rakhee; Garg, Nitasha; Bhusari, Priya; Watts, Ankit; Mittal, Bhagwant R

2013-10-01

To study quality control parameters of routinely prepared positron emission tomography (PET) radiopharmaceuticals. Three PET radiopharmaceuticals fluorine-18 fluorodeoxyglucose (F-18 FDG), N-13 ammonia (N-13 NH3), and Ga-68 DOTATATE (n = 25 each), prepared by standardized protocols were used. The radionuclide purity, radiochemical purity, residual solvents, pH, endotoxins, and sterility of these radiopharmaceuticals were determined. The physical half-life of radionuclide in radiopharmaceuticals, determined by both graphical and formula method, demonstrated purity of radionuclides used. pH of all PET radiopharmaceuticals used was in the range of 5-6.5. No microbial growth was observed in radiopharmaceutical preparations. The residual solvents, chemical impurity, and pyrogens were within the permissible limits. All three PET radiopharmaceuticals were safe for intravenous administration.

How to design PET experiments to study neurochemistry: application to alcoholism.

PubMed

Morris, Evan D; Lucas, Molly V; Petrulli, J Ryan; Cosgrove, Kelly P

2014-03-01

Positron Emission Tomography (PET) (and the related Single Photon Emission Computed Tomography) is a powerful imaging tool with a molecular specificity and sensitivity that are unique among imaging modalities. PET excels in the study of neurochemistry in three ways: 1) It can detect and quantify neuroreceptor molecules; 2) it can detect and quantify changes in neurotransmitters; and 3) it can detect and quantify exogenous drugs delivered to the brain. To carry out any of these applications, the user must harness the power of kinetic modeling. Further, the quality of the information gained is only as good as the soundness of the experimental design. This article reviews the concepts behind the three main uses of PET, the rationale behind kinetic modeling of PET data, and some of the key considerations when planning a PET experiment. Finally, some examples of PET imaging related to the study of alcoholism are discussed and critiqued.

How to Design PET Experiments to Study Neurochemistry: Application to Alcoholism

PubMed Central

Morris, Evan D.; Lucas, Molly V.; Petrulli, J. Ryan; Cosgrove, Kelly P.

2014-01-01

Positron Emission Tomography (PET) (and the related Single Photon Emission Computed Tomography) is a powerful imaging tool with a molecular specificity and sensitivity that are unique among imaging modalities. PET excels in the study of neurochemistry in three ways: 1) It can detect and quantify neuroreceptor molecules; 2) it can detect and quantify changes in neurotransmitters; and 3) it can detect and quantify exogenous drugs delivered to the brain. To carry out any of these applications, the user must harness the power of kinetic modeling. Further, the quality of the information gained is only as good as the soundness of the experimental design. This article reviews the concepts behind the three main uses of PET, the rationale behind kinetic modeling of PET data, and some of the key considerations when planning a PET experiment. Finally, some examples of PET imaging related to the study of alcoholism are discussed and critiqued. PMID:24600335

In Vivo Imaging and Monitoring of Transplanted Stem Cells: Clinical Applications

PubMed Central

Rodriguez-Porcel, Martin

2010-01-01

Regenerative medicine using stem cells has appeared as a potential therapeutic alternative for coronary artery disease, and stem cell clinical studies are currently on their way. However, initial results of these studies have provided mixed information, in part because of the inability to correlate organ functional information with the presence/absence of transplanted stem cells. Recent advances in molecular biology and imaging have allowed the successful noninvasive monitoring of transplanted stem cells in the living subject. In this article, different imaging strategies (direct labeling, indirect labeling with reporter genes) to study the viability and biology of stem cells are discussed. In addition, the limitations of each approach and imaging modality (eg, single photon emission computed tomography, positron emission tomography, and MRI) and their requirements for clinical use are addressed. Use of these strategies will be critical as the different regenerative therapies are being tested for clinical use. PMID:20425184

The role of positron emission tomography and positron emission tomography/computed tomography in thyroid tumours: an overview.

PubMed

Treglia, Giorgio; Muoio, Barbara; Giovanella, Luca; Salvatori, Massimo

2013-05-01

Positron emission tomography (PET) and PET/computed tomography (PET/CT) with different tracers have been increasingly used in patients with thyroid tumours. The aim of this article is to perform an overview based on literature data about the usefulness of PET imaging in this setting. The role of Fluorine-18-Fluorodeoxyglucose (FDG) PET and PET/CT in differentiated thyroid carcinoma (DTC) is well established, particularly in patients presenting with elevated serum thyroglobulin levels and negative radioiodine whole-body scan. Iodine-124 PET and PET/CT may serve a role in staging DTC and obtaining lesional dosimetry for a better and more rationale planning of treatment with Iodine-131. FDG-PET and PET/CT are useful in the post-thyroidectomy staging of high-risk patients with less differentiated histological subtypes. PET and PET/CT with different tracers seem to be useful methods in localizing the source of elevated calcitonin levels in patients with recurrent medullary thyroid carcinoma. Incorporation of FDG-PET or PET/CT into the initial workup of patients with indeterminate thyroid nodules at fine needle aspiration biopsy deserves further investigation. FDG-PET report should suggest further evaluation when focal thyroid incidentalomas are described because these findings are associated with a significant risk of cancer.

Radiation Hard Sensors for Surveillance.

DTIC Science & Technology

1988-03-11

track position measurements were noted. E. Heijne (CERN) reported on the degradation of silicon detectors for doses larger than 2x10 11 muons /cm 2...Workshop on Transmission and Emission Computerized Tomography , July 1978, Seoul, Korea Nahmias C., Kenyon D.B., Garnett E.S.: Optimization of...crystal size in emission computed tomography . IEEE Trans ,.-.e Nucl Sci NS-27: 529-532, 1980. Mullani N.A., Ficke D.C., Ter-Pogossian M.M.: Cesium Fluoride

Usefulness of whole-body fluorine-18-fluorodeoxyglucose positron emission tomography in patients with large-vessel vasculitis: a systematic review.

PubMed

Treglia, Giorgio; Mattoli, Maria Vittoria; Leccisotti, Lucia; Ferraccioli, Gianfranco; Giordano, Alessandro

2011-10-01

The objective of this study is to systematically review the role of positron emission tomography (PET) and PET/computed tomography (PET/CT) with fluorine-18-fluorodeoxyglucose (FDG) in patients with large-vessel vasculitis (LVV). A comprehensive literature search of published studies through April 2011 in PubMed/MEDLINE and Scopus databases regarding whole-body FDG-PET and PET/CT in patients with LVV was performed. We identified 32 studies including 604 LVV patients. The main findings of these studies are presented. The conclusions are the following: (1) FDG-PET and PET/CT are useful imaging methods in the initial diagnosis and in the assessment of activity and extent of disease in patients with LVV; (2) the correlation between FDG-PET findings and serological levels of inflammatory markers, as well as the usefulness of FDG-PET and PET/CT in evaluating treatment response, remains unclear; (3) it appears that there is a superiority of FDG-PET and PET/CT over conventional imaging methods in the diagnosis of LVV, but not in assessing disease activity under immunosuppressive treatment, in predicting relapse or in evaluating vascular complications; and (4) given the heterogeneity between studies with regard to PET analysis and diagnostic criteria, a standardization of the technique is needed.

Allan Cormack, Computerized Axial Tomography (CAT), and Magnetic Resonance

Science.gov Websites

Radiopharmaceuticals, DOE Technical Report, 1977 Emission Computed Tomography: A New Technique for the Quantitative Extending the Power of Nuclear Magnetic Resonance Techniques Magnetic Resonance Imaging Research Top Some

Epilepsy Surgery for Individuals with TSC

MedlinePlus

... tomography (PET), single-photon emission tomography (SPECT), magnetoencephalography (MEG), Diffusion Tensor Imaging (DTI), and functional MRI (fMRI). ... sclerosis: a comparison of high resolution EEG and MEG. Epilepsia 47:108-114 Jansen FE, Huffelen ACV, ...

SPECT/CT in imaging foot and ankle pathology-the demise of other coregistration techniques.

PubMed

Mohan, Hosahalli K; Gnanasegaran, Gopinath; Vijayanathan, Sanjay; Fogelman, Ignac

2010-01-01

Disorders of the ankle and foot are common and given the complex anatomy and function of the foot, they present a significant clinical challenge. Imaging plays a crucial role in the management of these patients, with multiple imaging options available to the clinician. The American College of radiology has set the appropriateness criteria for the use of the available investigating modalities in the management of foot and ankle pathologies. These are broadly classified into anatomical and functional imaging modalities. Recently, single-photon emission computed tomography and/or computed tomography scanners, which can elegantly combine functional and anatomical images have been introduced, promising an exciting and important development. This review describes our clinical experience with single-photon emission computed tomography and/or computed tomography and discusses potential applications of these techniques.

Posterior mediastinal ganglioneuroma with peripheral replacement by white and brown adipocytes resulting in diagnostic fallacy from a false-positive 18F-2-fluoro-2-deoxyglucose-positron emission tomography finding: a case report

PubMed Central

2014-01-01

Introduction Ganglioneuroma is a rare tumor in the posterior mediastinum; fat-containing ganglioneuromas are rarely reported. The present case report documents a brown fat-containing, posterior mediastinal ganglioneuroma, which has not been reported previously. Radiological examination, in particular 18F-2-fluoro-2-deoxyglucose-positron emission tomography, suggested that the tumor had low-grade malignant potential. This led to uncertainty at preoperative diagnosis. Case presentation An asymptomatic 66-year-old Japanese woman with no significant past medical history was referred for the evaluation of a posterior mediastinal mass. Although its size had not changed in the past 5 years, a malignant lipomatous tumor could not be excluded due to the presence of intratumoral fat and increased 18F-2-fluoro-2-deoxyglucose uptake observed by positron emission tomography imaging. A computed tomography-guided core-needle biopsy revealed a mixture of mature adipocytes, spindle-shaped cells, and fibrotic stroma. Definite diagnosis was not possible, and surgical resection was performed. Three years after the surgery, she remains disease-free. Conclusions Histological diagnosis of the surgically resected mass confirmed ganglioneuroma with substantial amounts of white and brown adipose tissues in peripheral areas. The existence of both ganglion cells and brown fat tissue intensified the accumulation of 18F-2-fluoro-2-deoxyglucose, resulting in a false-positive result by positron emission tomography. Considering this, ganglioneuroma should not be excluded either clinically or pathologically in fat-containing, posterior mediastinal tumors. PMID:25319096

[18F]FDG labeling of neural stem cells for in vivo cell tracking with positron emission tomography: inhibition of tracer release by phloretin.

PubMed

Stojanov, Katica; de Vries, Erik F J; Hoekstra, Dick; van Waarde, Aren; Dierckx, Rudi A J O; Zuhorn, Inge S

2012-02-01

The introduction of neural stem cells into the brain has promising therapeutic potential for the treatment of neurodegenerative diseases. To monitor the cellular replacement therapy, that is, to determine stem cell migration, survival, and differentiation, in vivo tracking methods are needed. Ideally, these tracking methods are noninvasive. Noninvasive tracking methods that have been successfully used for the visualization of blood-derived progenitor cells include magnetic resonance imaging and radionuclide imaging using single-photon emission computed tomography (SPECT) and positron emission tomography (PET). The SPECT tracer In-111-oxine is suitable for stem cell labeling, but for studies in small animals, the higher sensitivity and facile quantification that can be obtained with PET are preferred. Here the potential of 2'-[18F]fluoro-2'-deoxy-D-glucose ([18F]-FDG), a PET tracer, for tracking of neural stem cell (NSCs) trafficking toward an inflammation site was investigated. [18F]-FDG turns out to be a poor radiopharmaceutical to label NSCs owing to the low labeling efficiency and substantial release of radioactivity from these cells. Efflux of [18F]-FDG from NSCs can be effectively reduced by phloretin in vitro, but inhibition of tracer release is insufficient in vivo for accurate monitoring of stem cell trafficking.

Dynamic Positron Emission Tomography Imaging of Renal Clearable Gold Nanoparticles

PubMed Central

Chen, Feng; Goel, Shreya; Hernandez, Reinier; Graves, Stephen A.; Shi, Sixiang; Nickles, Robert J.; Cai, Weibo

2016-01-01

Optical imaging has been the primary imaging modality for nearly all of the renal clearable nanoparticles since 2007. Due to the tissue depth penetration limitation, providing accurate organ kinetics non-invasively has long been a huge challenge. Although a more quantitative imaging technique has been developed by labeling nanoparticles with single-photon emission computed tomography (SPECT) isotopes, the low temporal resolution of SPECT still limits its potential for visualizing the rapid dynamic process of renal clearable nanoparticles in vivo. Here, we report the dynamic positron emission tomography (PET) imaging of renal clearable gold (Au) nanoparticles by labeling them with copper-64 (64Cu) to form 64Cu-NOTA-Au-GSH. Systematic nanoparticle synthesis and characterizations were performed to demonstrate the efficient renal clearance of as-prepared nanoparticles. A rapid renal clearance of 64Cu-NOTA-Au-GSH was observed (>75 %ID at 24 h post-injection) with its elimination half-life calculated to be less than 6 min, over 130 times shorter than previously reported similar nanoparticles. Dynamic PET imaging not only addresses the current challenges in accurately and non-invasively acquiring the organ kinetics, but also potentially provides a highly useful tool for studying renal clearance mechanism of other ultra-small nanoparticles, as well as the diagnosis of kidney diseases in the near future. PMID:27062146

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 deficiencies of purely MRI-based AC approaches in PET/MRI and improve standalone PET imaging. PMID:26843243

Attenuation correction in emission tomography using the emission data—A review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berker, Yannick, E-mail: berker@mail.med.upenn.edu; 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 thenmore » 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 deficiencies of purely MRI-based AC approaches in PET/MRI and improve standalone PET imaging.« less

Radionuclide and Fluorescence Imaging of Clear Cell Renal Cell Carcinoma Using Dual Labeled Anti-Carbonic Anhydrase IX Antibody G250.

PubMed

Muselaers, Constantijn H J; Rijpkema, Mark; Bos, Desirée L; Langenhuijsen, Johan F; Oyen, Wim J G; Mulders, Peter F A; Oosterwijk, Egbert; Boerman, Otto C

2015-08-01

Tumor targeted optical imaging using antibodies labeled with near infrared fluorophores is a sensitive imaging modality that might be used during surgery to assure complete removal of malignant tissue. We evaluated the feasibility of dual modality imaging and image guided surgery with the dual labeled anti-carbonic anhydrase IX antibody preparation (111)In-DTPA-G250-IRDye800CW in mice with intraperitoneal clear cell renal cell carcinoma. BALB/c nu/nu mice with intraperitoneal SK-RC-52 lesions received 10 μg DTPA-G250-IRDye800CW labeled with 15 MBq (111)In or 10 μg of the dual labeled irrelevant control antibody NUH-82 (20 mice each). To evaluate when tumors could be detected, 4 mice per group were imaged weekly during 5 weeks with single photon emission computerized tomography/computerized tomography and the fluorescence imaging followed by ex vivo biodistribution studies. As early as 1 week after tumor cell inoculation single photon emission computerized tomography and fluorescence images showed clear delineation of intraperitoneal clear cell renal cell carcinoma with good concordance between single photon emission computerized tomography/computerized tomography and fluorescence images. The high and specific accumulation of the dual labeled antibody conjugate in tumors was confirmed in the biodistribution studies. Maximum tumor uptake was observed 1 week after inoculation (mean ± SD 58.5% ± 18.7% vs 5.6% ± 2.3% injected dose per gm for DTPA-G250-IRDye800CW vs NUH-82, respectively). High tumor uptake was also observed at other time points. This study demonstrates the feasibility of dual modality imaging with dual labeled antibody (111)In-DTPA-G250-IRDye800CW in a clear cell renal cell carcinoma model. Results indicate that preoperative and intraoperative detection of carbonic anhydrase IX expressing tumors, positive resection margins and metastasis might be feasible with this approach. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Rationale and design of the dual-energy computed tomography for ischemia determination compared to "gold standard" non-invasive and invasive techniques (DECIDE-Gold): A multicenter international efficacy diagnostic study of rest-stress dual-energy computed tomography angiography with perfusion.

PubMed

Truong, Quynh A; Knaapen, Paul; Pontone, Gianluca; Andreini, Daniele; Leipsic, Jonathon; Carrascosa, Patricia; Lu, Bin; Branch, Kelley; Raman, Subha; Bloom, Stephen; Min, James K

2015-10-01

Dual-energy CT (DECT) has potential to improve myocardial perfusion for physiologic assessment of coronary artery disease (CAD). Diagnostic performance of rest-stress DECT perfusion (DECTP) is unknown. DECIDE-Gold is a prospective multicenter study to evaluate the accuracy of DECT to detect hemodynamic (HD) significant CAD, as compared to fractional flow reserve (FFR) as a reference standard. Eligible participants are subjects with symptoms of CAD referred for invasive coronary angiography (ICA). Participants will undergo DECTP, which will be performed by pharmacological stress, and participants will subsequently proceed to ICA and FFR. HD-significant CAD will be defined as FFR ≤ 0.80. In those undergoing myocardial stress imaging (MPI) by positron emission tomography (PET), single photon emission computed tomography (SPECT) or cardiac magnetic resonance (CMR) imaging, ischemia will be graded by % ischemic myocardium. Blinded core laboratory interpretation will be performed for CCTA, DECTP, MPI, ICA, and FFR. Primary endpoint is accuracy of DECTP to detect ≥1 HD-significant stenosis at the subject level when compared to FFR. Secondary and tertiary endpoints are accuracies of combinations of DECTP at the subject and vessel levels compared to FFR and MPI. DECIDE-Gold will determine the performance of DECTP for diagnosing ischemia.

Nuclear medicine imaging system

DOEpatents

Bennett, G.W.; Brill, A.B.; Bizais, Y.J.C.; Rowe, R.W.; Zubal, I.G.

1983-03-11

It is an object of this invention to provide a nuclear imaging system having the versatility to do positron annihilation studies, rotating single or opposed camera gamma emission studies, and orthogonal gamma emission studies. It is a further object of this invention to provide an imaging system having the capability for orthogonal dual multipinhole tomography. It is another object of this invention to provide a nuclear imaging system in which all available energy data, as well as patient physiological data, are acquired simultaneously in list mode.

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.

Simultaneous whole body 18F-fluorodeoxyglucose positron emission tomography magnetic resonance imaging for evaluation of pediatric cancer: Preliminary experience and comparison with 18F-fluorodeoxyglucose positron emission tomography computed tomography

PubMed Central

Pugmire, Brian S; Guimaraes, Alexander R; Lim, Ruth; Friedmann, Alison M; Huang, Mary; Ebb, David; Weinstein, Howard; Catalano, Onofrio A; Mahmood, Umar; Catana, Ciprian; Gee, Michael S

2016-01-01

AIM: To describe our preliminary experience with simultaneous whole body 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography and magnetic resonance imaging (PET-MRI) in the evaluation of pediatric oncology patients. METHODS: This prospective, observational, single-center study was Health Insurance Portability and Accountability Act-compliant, and institutional review board approved. To be eligible, a patient was required to: (1) have a known or suspected cancer diagnosis; (2) be under the care of a pediatric hematologist/oncologist; and (3) be scheduled for clinically indicated 18F-FDG positron emission tomography-computed tomography (PET-CT) examination at our institution. Patients underwent PET-CT followed by PET-MRI on the same day. PET-CT examinations were performed using standard department protocols. PET-MRI studies were acquired with an integrated 3 Tesla PET-MRI scanner using whole body T1 Dixon, T2 HASTE, EPI diffusion-weighted imaging (DWI) and STIR sequences. No additional radiotracer was given for the PET-MRI examination. Both PET-CT and PET-MRI examinations were reviewed by consensus by two study personnel. Test performance characteristics of PET-MRI, for the detection of malignant lesions, including FDG maximum standardized uptake value (SUVmax) and minimum apparent diffusion coefficient (ADCmin), were calculated on a per lesion basis using PET-CT as a reference standard. RESULTS: A total of 10 whole body PET-MRI exams were performed in 7 pediatric oncology patients. The mean patient age was 16.1 years (range 12-19 years) including 6 males and 1 female. A total of 20 malignant and 21 benign lesions were identified on PET-CT. PET-MRI SUVmax had excellent correlation with PET-CT SUVmax for both benign and malignant lesions (R = 0.93). PET-MRI SUVmax > 2.5 had 100% accuracy for discriminating benign from malignant lesions using PET-CT reference. Whole body DWI was also evaluated: the mean ADCmin of malignant lesions (780.2 + 326.6) was significantly lower than that of benign lesions (1246.2 + 417.3; P = 0.0003; Student’s t test). A range of ADCmin thresholds for malignancy were evaluated, from 0.5-1.5 × 10-3 mm2/s. The 1.0 × 10-3 ADCmin threshold performed best compared with PET-CT reference (68.3% accuracy). However, the accuracy of PET-MRI SUVmax was significantly better than ADCmin for detecting malignant lesions compared with PET-CT reference (P < 0.0001; two-tailed McNemar’s test). CONCLUSION: These results suggest a clinical role for simultaneous whole body PET-MRI in evaluating pediatric cancer patients. PMID:27028112

Simultaneous whole body (18)F-fluorodeoxyglucose positron emission tomography magnetic resonance imaging for evaluation of pediatric cancer: Preliminary experience and comparison with (18)F-fluorodeoxyglucose positron emission tomography computed tomography.

PubMed

Pugmire, Brian S; Guimaraes, Alexander R; Lim, Ruth; Friedmann, Alison M; Huang, Mary; Ebb, David; Weinstein, Howard; Catalano, Onofrio A; Mahmood, Umar; Catana, Ciprian; Gee, Michael S

2016-03-28

To describe our preliminary experience with simultaneous whole body (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography and magnetic resonance imaging (PET-MRI) in the evaluation of pediatric oncology patients. This prospective, observational, single-center study was Health Insurance Portability and Accountability Act-compliant, and institutional review board approved. To be eligible, a patient was required to: (1) have a known or suspected cancer diagnosis; (2) be under the care of a pediatric hematologist/oncologist; and (3) be scheduled for clinically indicated (18)F-FDG positron emission tomography-computed tomography (PET-CT) examination at our institution. Patients underwent PET-CT followed by PET-MRI on the same day. PET-CT examinations were performed using standard department protocols. PET-MRI studies were acquired with an integrated 3 Tesla PET-MRI scanner using whole body T1 Dixon, T2 HASTE, EPI diffusion-weighted imaging (DWI) and STIR sequences. No additional radiotracer was given for the PET-MRI examination. Both PET-CT and PET-MRI examinations were reviewed by consensus by two study personnel. Test performance characteristics of PET-MRI, for the detection of malignant lesions, including FDG maximum standardized uptake value (SUVmax) and minimum apparent diffusion coefficient (ADCmin), were calculated on a per lesion basis using PET-CT as a reference standard. A total of 10 whole body PET-MRI exams were performed in 7 pediatric oncology patients. The mean patient age was 16.1 years (range 12-19 years) including 6 males and 1 female. A total of 20 malignant and 21 benign lesions were identified on PET-CT. PET-MRI SUVmax had excellent correlation with PET-CT SUVmax for both benign and malignant lesions (R = 0.93). PET-MRI SUVmax > 2.5 had 100% accuracy for discriminating benign from malignant lesions using PET-CT reference. Whole body DWI was also evaluated: the mean ADCmin of malignant lesions (780.2 + 326.6) was significantly lower than that of benign lesions (1246.2 + 417.3; P = 0.0003; Student's t test). A range of ADCmin thresholds for malignancy were evaluated, from 0.5-1.5 × 10(-3) mm(2)/s. The 1.0 × 10(-3) ADCmin threshold performed best compared with PET-CT reference (68.3% accuracy). However, the accuracy of PET-MRI SUVmax was significantly better than ADCmin for detecting malignant lesions compared with PET-CT reference (P < 0.0001; two-tailed McNemar's test). These results suggest a clinical role for simultaneous whole body PET-MRI in evaluating pediatric cancer patients.

Medical Imaging.

ERIC Educational Resources Information Center

Jaffe, C. Carl

1982-01-01

Describes principle imaging techniques, their applications, and their limitations in terms of diagnostic capability and possible adverse biological effects. Techniques include film radiography, computed tomography, nuclear medicine, positron emission tomography (PET), ultrasonography, nuclear magnetic resonance, and digital radiography. PET has…

Nuclear Cardiology: Are We Using the Right Protocols and Tracers the Right Way?

PubMed

Dondi, Maurizio; Pascual, Thomas; Paez, Diana; Einstein, Andrew J

2017-12-01

The field of nuclear cardiology has changed considerably over recent years, with greater attention paid to safety and radiation protection issues. The wider usage of technetium-99m (Tc-99m)-labeled radiopharmaceuticals for single-photon emission computed tomography (SPECT) imaging using gamma cameras has contributed to better quality studies and lower radiation exposure to patients. Increased availability of tracers and scanners for positron emission tomography (PET) will help further improve the quality of studies and quantify myocardial blood flow and myocardial flow reserve, thus enhancing the contribution of non-invasive imaging to the management of coronary artery disease. The introduction of new instrumentation such as solid state cameras and new software will help reduce further radiation exposure to patients undergoing nuclear cardiology studies. Results from recent studies, focused on assessing the relationship between best practices and radiation risk, provide useful insights on simple measures to improve the safety of nuclear cardiology studies without compromising the quality of results.

Intraprocedural yttrium-90 positron emission tomography/CT for treatment optimization of yttrium-90 radioembolization.

PubMed

Bourgeois, Austin C; Chang, Ted T; Bradley, Yong C; Acuff, Shelley N; Pasciak, Alexander S

2014-02-01

Radioembolization with yttrium-90 ((90)Y) microspheres relies on delivery of appropriate treatment activity to ensure patient safety and optimize treatment efficacy. We report a case in which (90)Y positron emission tomography (PET)/computed tomography (CT) was performed to optimize treatment planning during a same-day, three-part treatment session. This treatment consisted of (i) an initial (90)Y infusion with a dosage determined using an empiric treatment planning model, (ii) quantitative (90)Y PET/CT imaging, and (iii) a secondary infusion with treatment planning based on quantitative imaging data with the goal of delivering a specific total tumor absorbed dose. © 2014 SIR Published by SIR All rights reserved.

Sarcoidosis Occurring After Solid Cancer: A Nonfortuitous Association

PubMed Central

Grados, Aurélie; Ebbo, Mikael; Bernit, Emmanuelle; Veit, Véronique; Mazodier, Karin; Jean, Rodolphe; Coso, Diane; Aurran-Schleinitz, Thérèse; Broussais, Florence; Bouabdallah, Reda; Gravis, Gwenaelle; Goncalves, Anthony; Giovaninni, Marc; Sève, Pascal; Chetaille, Bruno; Gavet-Bongo, Florence; Weitten, Thierry; Pavic, Michel; Harlé, Jean-Robert; Schleinitz, Nicolas

2015-01-01

Abstract The association between cancer and sarcoidosis is controversial. Some epidemiological studies show an increase of the incidence of cancer in patients with sarcoidosis but only few cases of sarcoidosis following cancer treatment have been reported. We conducted a retrospective case study from internal medicine and oncology departments for patients presenting sarcoidosis after solid cancer treatment. We also performed a literature review to search for patients who developed sarcoidosis after solid cancer. We describe the clinical, biological, and radiological characteristics and outcome of these patients. Twelve patients were included in our study. Various cancers were observed with a predominance of breast cancer. Development of sarcoidosis appeared in the 3 years following cancer and was asymptomatic in half of the patients. The disease was frequently identified after a follow-up positron emission tomography computerized tomography evaluation. Various manifestations were observed but all patients presented lymph node involvement. Half of the patients required systemic therapy. With a median follow-up of 73 months, no patient developed cancer relapse. Review of the literature identified 61 other patients for which the characteristics of both solid cancer and sarcoidosis were similar to those observed in our series. This report demonstrates that sarcoidosis must be considered in the differential diagnosis of patients with a history of malignancy who have developed lymphadenopathy or other lesions on positron emission tomography computerized tomography. Histological confirmation of cancer relapse is mandatory in order to avoid unjustified treatments. This association should be consider as a protective factor against cancer relapse. PMID:26181571

The relationship between duration of psoriasis, vascular inflammation, and cardiovascular events.

PubMed

Egeberg, Alexander; Skov, Lone; Joshi, Aditya A; Mallbris, Lotus; Gislason, Gunnar H; Wu, Jashin J; Rodante, Justin; Lerman, Joseph B; Ahlman, Mark A; Gelfand, Joel M; Mehta, Nehal N

2017-10-01

Psoriasis is associated with risk of cardiovascular (CV) disease (CVD) and a major adverse CV event (MACE). Whether psoriasis duration affects risk of vascular inflammation and MACEs has not been well characterized. We utilized two resources to understand the effect of psoriasis duration on vascular disease and CV events: (1) a human imaging study and (2) a population-based study of CVD events. First, patients with psoriasis (N = 190) underwent fludeoxyglucose F 18 positron emission tomography/computed tomography (duration effect reported as a β-coefficient). Second, MACE risk was examined by using nationwide registries (adjusted hazard ratios in patients with psoriasis (n = 87,161) versus the general population (n = 4,234,793). In the human imaging study, patients were young, of low CV risk by traditional risk scores, and had a high prevalence of cardiometabolic diseases. Vascular inflammation by fludeoxyglucose F 18 positron emission tomography/computed tomography was significantly associated with disease duration (β = 0.171, P = .002). In the population-based study, psoriasis duration had strong relationship with MACE risk (1.0% per additional year of psoriasis duration [hazard ratio, 1.010; 95% confidence interval, 1.007-1.013]). These studies utilized observational data. We found detrimental effects of psoriasis duration on vascular inflammation and MACE, suggesting that cumulative duration of exposure to low-grade chronic inflammation may accelerate vascular disease development and MACEs. Providers should consider inquiring about duration of disease to counsel for heightened CVD risk in psoriasis. Copyright © 2017 American Academy of Dermatology, Inc. All rights reserved.

Fast Neutron Emission Tomography of Used Nuclear Fuel Assemblies

NASA Astrophysics Data System (ADS)

Hausladen, Paul; Iyengar, Anagha; Fabris, Lorenzo; Yang, Jinan; Hu, Jianwei; Blackston, Matthew

2017-09-01

Oak Ridge National Laboratory is developing a new capability to perform passive fast neutron emission tomography of spent nuclear fuel assemblies for the purpose of verifying their integrity for international safeguards applications. Most of the world's plutonium is contained in spent nuclear fuel, so it is desirable to detect the diversion of irradiated fuel rods from an assembly prior to its transfer to ``difficult to access'' storage, such as a dry cask or permanent repository, where re-verification is practically impossible. Nuclear fuel assemblies typically consist of an array of fuel rods that, depending on exposure in the reactor and consequent ingrowth of 244Cm, are spontaneous sources of as many as 109 neutrons s-1. Neutron emission tomography uses collimation to isolate neutron activity along ``lines of response'' through the assembly and, by combining many collimated views through the object, mathematically extracts the neutron emission from each fuel rod. This technique, by combining the use of fast neutrons -which can penetrate the entire fuel assembly -and computed tomography, is capable of detecting vacancies or substitutions of individual fuel rods. This paper will report on the physics design and component testing of the imaging system. This material is based upon work supported by the U.S. Department of Energy, Office of Defense Nuclear Nonproliferation Research and Development within the National Nuclear Security Administration, under Contract Number DE-AC05-00OR22725.

Representation of photon limited data in emission tomography using origin ensembles

NASA Astrophysics Data System (ADS)

Sitek, A.

2008-06-01

Representation and reconstruction of data obtained by emission tomography scanners are challenging due to high noise levels in the data. Typically, images obtained using tomographic measurements are represented using grids. In this work, we define images as sets of origins of events detected during tomographic measurements; we call these origin ensembles (OEs). A state in the ensemble is characterized by a vector of 3N parameters Y, where the parameters are the coordinates of origins of detected events in a three-dimensional space and N is the number of detected events. The 3N-dimensional probability density function (PDF) for that ensemble is derived, and we present an algorithm for OE image estimation from tomographic measurements. A displayable image (e.g. grid based image) is derived from the OE formulation by calculating ensemble expectations based on the PDF using the Markov chain Monte Carlo method. The approach was applied to computer-simulated 3D list-mode positron emission tomography data. The reconstruction errors for a 10 000 000 event acquisition for simulated ranged from 0.1 to 34.8%, depending on object size and sampling density. The method was also applied to experimental data and the results of the OE method were consistent with those obtained by a standard maximum-likelihood approach. The method is a new approach to representation and reconstruction of data obtained by photon-limited emission tomography measurements.

The neurobiology of glucocerebrosidase-associated parkinsonism: a positron emission tomography study of dopamine synthesis and regional cerebral blood flow.

PubMed

Goker-Alpan, Ozlem; Masdeu, Joseph C; Kohn, Philip D; Ianni, Angela; Lopez, Grisel; Groden, Catherine; Chapman, Molly C; Cropp, Brett; Eisenberg, Daniel P; Maniwang, Emerson D; Davis, Joie; Wiggs, Edythe; Sidransky, Ellen; Berman, Karen F

2012-08-01

Mutations in GBA, the gene encoding glucocerebrosidase, the enzyme deficient in Gaucher disease, are common risk factors for Parkinson disease, as patients with Parkinson disease are over five times more likely to carry GBA mutations than healthy controls. Patients with GBA mutations generally have an earlier onset of Parkinson disease and more cognitive impairment than those without GBA mutations. We investigated whether GBA mutations alter the neurobiology of Parkinson disease, studying brain dopamine synthesis and resting regional cerebral blood flow in 107 subjects (38 women, 69 men). We measured dopamine synthesis with (18)F-fluorodopa positron emission tomography, and resting regional cerebral blood flow with H(2)(15)O positron emission tomography in the wakeful, resting state in four study groups: (i) patients with Parkinson disease and Gaucher disease (n = 7, average age = 56.6 ± 9.2 years); (ii) patients with Parkinson disease without GBA mutations (n = 11, 62.1 ± 7.1 years); (iii) patients with Gaucher disease without parkinsonism, but with a family history of Parkinson disease (n = 14, 52.6 ± 12.4 years); and (iv) healthy GBA-mutation carriers with a family history of Parkinson disease (n = 7, 50.1 ± 18 years). We compared each study group with a matched control group. Data were analysed with region of interest and voxel-based methods. Disease duration and Parkinson disease functional and staging scores were similar in the two groups with parkinsonism, as was striatal dopamine synthesis: both had greatest loss in the caudal striatum (putamen Ki loss: 44 and 42%, respectively), with less reduction in the caudate (20 and 18% loss). However, the group with both Parkinson and Gaucher diseases showed decreased resting regional cerebral blood flow in the lateral parieto-occipital association cortex and precuneus bilaterally. Furthermore, two subjects with Gaucher disease without parkinsonian manifestations showed diminished striatal dopamine. In conclusion, the pattern of dopamine loss in patients with both Parkinson and Gaucher disease was similar to sporadic Parkinson disease, indicating comparable damage in midbrain neurons. However, H(2)(15)O positron emission tomography studies indicated that these subjects have decreased resting activity in a pattern characteristic of diffuse Lewy body disease. These findings provide insight into the pathophysiology of GBA-associated parkinsonism.

The neurobiology of glucocerebrosidase-associated parkinsonism: a positron emission tomography study of dopamine synthesis and regional cerebral blood flow

PubMed Central

Goker-Alpan, Ozlem; Masdeu, Joseph C.; Kohn, Philip D.; Ianni, Angela; Lopez, Grisel; Groden, Catherine; Chapman, Molly C.; Cropp, Brett; Eisenberg, Daniel P.; Maniwang, Emerson D.; Davis, Joie; Wiggs, Edythe; Berman, Karen F.

2012-01-01

Mutations in GBA, the gene encoding glucocerebrosidase, the enzyme deficient in Gaucher disease, are common risk factors for Parkinson disease, as patients with Parkinson disease are over five times more likely to carry GBA mutations than healthy controls. Patients with GBA mutations generally have an earlier onset of Parkinson disease and more cognitive impairment than those without GBA mutations. We investigated whether GBA mutations alter the neurobiology of Parkinson disease, studying brain dopamine synthesis and resting regional cerebral blood flow in 107 subjects (38 women, 69 men). We measured dopamine synthesis with 18F-fluorodopa positron emission tomography, and resting regional cerebral blood flow with H215O positron emission tomography in the wakeful, resting state in four study groups: (i) patients with Parkinson disease and Gaucher disease (n = 7, average age = 56.6 ± 9.2 years); (ii) patients with Parkinson disease without GBA mutations (n = 11, 62.1 ± 7.1 years); (iii) patients with Gaucher disease without parkinsonism, but with a family history of Parkinson disease (n = 14, 52.6 ± 12.4 years); and (iv) healthy GBA-mutation carriers with a family history of Parkinson disease (n = 7, 50.1 ± 18 years). We compared each study group with a matched control group. Data were analysed with region of interest and voxel-based methods. Disease duration and Parkinson disease functional and staging scores were similar in the two groups with parkinsonism, as was striatal dopamine synthesis: both had greatest loss in the caudal striatum (putamen Ki loss: 44 and 42%, respectively), with less reduction in the caudate (20 and 18% loss). However, the group with both Parkinson and Gaucher diseases showed decreased resting regional cerebral blood flow in the lateral parieto-occipital association cortex and precuneus bilaterally. Furthermore, two subjects with Gaucher disease without parkinsonian manifestations showed diminished striatal dopamine. In conclusion, the pattern of dopamine loss in patients with both Parkinson and Gaucher disease was similar to sporadic Parkinson disease, indicating comparable damage in midbrain neurons. However, H215O positron emission tomography studies indicated that these subjects have decreased resting activity in a pattern characteristic of diffuse Lewy body disease. These findings provide insight into the pathophysiology of GBA-associated parkinsonism. PMID:22843412

Lung Hot Spot Without Corresponding Computed Tomography Abnormality on Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: Artifactual or Real, Iatrogenic or Pathologic?

PubMed

Liu, Yiyan

Focal lung uptake without corresponding lesions or abnormalities on computed tomography (CT) scan poses a dilemma in the interpretation of fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). A limited number of case reports have previously suggested an artifactual or iatrogenic nature of the uptake. In the present study, 8 relevant cases were included within a retrospective search of the database. Medical records were reviewed for follow-up radiological and pathologic information. In 7 of 8 cases with focal increased FDG uptake but no corresponding lesions or abnormalities on CT scan, the lung hot spots were artifactual or iatrogenic upon follow-up diagnostic chest CT or repeated PET/CT or both the scans. Microemboli were most likely a potential cause of the pulmonary uptake, with or without partial paravenous injection. One case in the series had a real pulmonary lesion demonstrated on follow-up PET/CT scans and on surgical pathology, although the initial integrated CT and follow-up diagnostic chest CT scans revealed negative findings to demonstrate pulmonary abnormalities corresponding to the hot spot on the PET scan. In conclusion, the finding of a lung hot spot in the absence of anatomical abnormality on FDG PET/CT was most likely artifactual or iatrogenic, but it might also represent a real pulmonary lesion. Nonvisualization of anatomical abnormality could be because of its small size and position directly overlying a segmental vessel. Further image follow-up is necessary and important to clarify the nature of the uptake. Copyright © 2017 Elsevier Inc. All rights reserved.

Nicotine Blocks Brain Estrogen Synthase (Aromatase): In Vivo Positron Emission Tomography Studies in Female Baboons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biegon, A.; Biegon, A.; Kim, S.-W.

Cigarette smoking and nicotine have complex effects on human physiology and behavior, including some effects similar to those elicited by inhibition of aromatase, the last enzyme in estrogen biosynthesis. We report the first in vivo primate study to determine whether there is a direct effect of nicotine administration on brain aromatase. Brain aromatase availability was examined with positron emission tomography and the selective aromatase inhibitor [{sup 11}C]vorozole in six baboons before and after exposure to IV nicotine at .015 and .03 mg/kg. Nicotine administration produced significant, dose-dependent reductions in [{sup 11}C]vorozole binding. The amygdala and preoptic area showed the largestmore » reductions. Plasma levels of nicotine and its major metabolite cotinine were similar to those found in cigarette smokers. Nicotine interacts in vivo with primate brain aromatase in regions involved in mood, aggression, and sexual behavior.« less

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.

Effect of gender on glucose utilization rates in healthy humans: A positron emission tomography study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miura, S.A.; Schapiro, M.B.; Grady, C.L.

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 thatmore » there are no differences in resting regional cerebral glucose utilization between young men and women.« less

Optical imaging of reporter gene expression using a positron-emission-tomography probe

NASA Astrophysics Data System (ADS)

Liu, Hongguang; Ren, Gang; Liu, Shuanglong; Zhang, Xiaofen; Chen, Luxi; Han, Peizhen; Cheng, Zhen

2010-11-01

Reporter gene/reporter probe technology is one of the most important techniques in molecular imaging. Lately, many reporter gene/reporter probe systems have been coupled to different imaging modalities such as positron emission tomography (PET) and optical imaging (OI). It has been recently found that OI techniques could be used to monitor radioactive tracers in vitro and in living subjects. In this study, we further demonstrate that a reporter gene/nuclear reporter probe system [herpes simplex virus type-1 thymidine kinase (HSV1-tk) and 9-(4-18F-fluoro-3-[hydroxymethyl] butyl) guanine ([18F]FHBG)] could be successfully imaged by OI in vitro and in vivo. OI with radioactive reporter probes will facilitate and broaden the applications of reporter gene/reporter probe techniques in medical research.

Brain abnormalities in murderers indicated by positron emission tomography.

PubMed

Raine, A; Buchsbaum, M; LaCasse, L

1997-09-15

Murderers pleading not guilty by reason of insanity (NGRI) are thought to have brain dysfunction, but there have been no previous studies reporting direct measures of both cortical and subcortical brain functioning in this specific group. Positron emission tomography brain imaging using a continuous performance challenge task was conducted on 41 murderers pleading not guilty by reason of insanity and 41 age- and sex-matched controls. Murderers were characterized by reduced glucose metabolism in the prefrontal cortex, superior parietal gyrus, left angular gyrus, and the corpus callosum, while abnormal asymmetries of activity (left hemisphere lower than right) were also found in the amygdala, thalamus, and medial temporal lobe. These preliminary findings provide initial indications of a network of abnormal cortical and subcortical brain processes that may predispose to violence in murderers pleading NGRI.

No-carrier-added (/sup 18/F)-N-methylspiroperidol

DOEpatents

Shiue, C.Y.; Fowler, J.S.; Wolf, A.P.

1985-10-04

The present invention is directed to the synthesis of a radioligand, labeled with a positron emitting radionuclide which is suitable for dynamic studies in humans using positron emission transaxial tomography. No-carrier-added (NCA) (/sup 18/F)-N-methylspiroperiodl is prepared from four different sustrates: p-nitrobenzonitrile, cyclopropyl p-nitrophenyl ketone, p-cyclopropanoyl-N,N,N-trimethylanilinium iodide and p-cyclopropanoyl-N,N,N-trimethylanilinium perchlorate. The process for the production of NCA (/sup 18/F)-N-methylspiroperidol is a nucleophilic aromatic substitution reaction. Furthermore, the compound of this invention is shown to be effective as a new drug of choice for in vivo examination of dopamine binding sites in a human brain. In particular, this drug is primarily useful in the noninvasive technique of positron emission transaxial tomography (PETT).

Long-term results of positron emission tomography-directed management of the neck in node-positive head and neck cancer after organ preservation therapy.

PubMed

Sjövall, Johanna; Chua, Benjamin; Pryor, David; Burmeister, Elizabeth; Foote, Matthew C; Panizza, Benedict; Burmeister, Bryan H; Porceddu, Sandro V

2015-03-01

The current study presents the long-term results from a study designed to evaluate a restaging positron emission tomography (PET) directed policy whereby neck dissections were omitted in all node positive head and neck squamous cell carcinoma (N+HNSCC) patients with PET-negative lymph nodes after definitive radiotherapy (RT), with or without chemotherapy. A post-therapy nodal response assessment with PET and computed tomography (CT) was performed in patients who achieved a complete response at the primary site after definitive radiotherapy. Patients with PET-negative lymph nodes were observed regardless of residual CT abnormalities. One hundred and twelve patients, the majority of whom (83 patients, 74%) had oropharyngeal primaries, were treated on protocol. Median follow-up was 62months. Negative and positive predictive values for the restaging PET was 97.1% and 77.8% respectively, with only one patient who was PET-negative after treatment experiencing an isolated nodal relapse. PET-guided management of the neck following organ preservation therapy effectively spares neck dissections in patients with N+HNSCC without compromising isolated nodal control or overall survival. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Myocardial contrast echocardiography in mice: technical and physiological aspects.

PubMed

Verkaik, Melissa; van Poelgeest, Erik M; Kwekkeboom, Rick F J; Ter Wee, Piet M; van den Brom, Charissa E; Vervloet, Marc G; Eringa, Etto C

2018-03-01

Myocardial contrast echocardiography (MCE) offers the opportunity to study myocardial perfusion defects in mice in detail. The value of MCE compared with single-photon emission computed tomography, positron emission tomography, and computed tomography consists of high spatial resolution, the possibility of quantification of blood volume, and relatively low costs. Nevertheless, a number of technical and physiological aspects should be considered to ensure reproducibility among research groups. The aim of this overview is to describe technical aspects of MCE and the physiological parameters that influence myocardial perfusion data obtained with this technique. First, technical aspects of MCE discussed in this technical review are logarithmic compression of ultrasound data by ultrasound systems, saturation of the contrast signal, and acquisition of images during different phases of the cardiac cycle. Second, physiological aspects of myocardial perfusion that are affected by the experimental design are discussed, including the anesthesia regimen, systemic cardiovascular effects of vasoactive agents used, and fluctuations in body temperature that alter myocardial perfusion. When these technical and physiological aspects of MCE are taken into account and adequately standardized, MCE is an easily accessible technique for mice that can be used to study the control of myocardial perfusion by a wide range of factors.

Molecular Imaging of Experimental Abdominal Aortic Aneurysms

PubMed Central

Ramaswamy, Aneesh K.; Hamilton, Mark; Joshi, Rucha V.; Kline, Benjamin P.; Li, Rui; Wang, Pu; Goergen, Craig J.

2013-01-01

Current laboratory research in the field of abdominal aortic aneurysm (AAA) disease often utilizes small animal experimental models induced by genetic manipulation or chemical application. This has led to the use and development of multiple high-resolution molecular imaging modalities capable of tracking disease progression, quantifying the role of inflammation, and evaluating the effects of potential therapeutics. In vivo imaging reduces the number of research animals used, provides molecular and cellular information, and allows for longitudinal studies, a necessity when tracking vessel expansion in a single animal. This review outlines developments of both established and emerging molecular imaging techniques used to study AAA disease. Beyond the typical modalities used for anatomical imaging, which include ultrasound (US) and computed tomography (CT), previous molecular imaging efforts have used magnetic resonance (MR), near-infrared fluorescence (NIRF), bioluminescence, single-photon emission computed tomography (SPECT), and positron emission tomography (PET). Mouse and rat AAA models will hopefully provide insight into potential disease mechanisms, and the development of advanced molecular imaging techniques, if clinically useful, may have translational potential. These efforts could help improve the management of aneurysms and better evaluate the therapeutic potential of new treatments for human AAA disease. PMID:23737735

Clinical oncologic applications of PET/MRI: a new horizon

PubMed Central

Partovi, Sasan; Kohan, Andres; Rubbert, Christian; Vercher-Conejero, Jose Luis; Gaeta, Chiara; Yuh, Roger; Zipp, Lisa; Herrmann, Karin A; Robbin, Mark R; Lee, Zhenghong; Muzic, Raymond F; Faulhaber, Peter; Ros, Pablo R

2014-01-01

Positron emission tomography/magnetic resonance imaging (PET/MRI) leverages the high soft-tissue contrast and the functional sequences of MR with the molecular information of PET in one single, hybrid imaging technology. This technology, which was recently introduced into the clinical arena in a few medical centers worldwide, provides information about tumor biology and microenvironment. Studies on indirect PET/MRI (use of positron emission tomography/computed tomography (PET/CT) images software fused with MRI images) have already generated interesting preliminary data to pave the ground for potential applications of PET/MRI. These initial data convey that PET/MRI is promising in neuro-oncology and head & neck cancer applications as well as neoplasms in the abdomen and pelvis. The pediatric and young adult oncology population requiring frequent follow-up studies as well as pregnant woman might benefit from PET/MRI due to its lower ionizing radiation dose. The indication and planning of therapeutic interventions and specifically radiation therapy in individual patients could be and to a certain extent are already facilitated by performing PET/MRI. The objective of this article is to discuss potential clinical oncology indications of PET/MRI. PMID:24753986

Primary central nervous system lymphoma in an human immunodeficiency virus-infected patient mimicking bilateral eye sign in brain seen in fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography.

PubMed

Kamaleshwaran, Koramadai Karuppusany; Thirugnanam, Rajasekar; Shibu, Deepu; Kalarikal, Radhakrishnan Edathurthy; Shinto, Ajit Sugunan

2014-04-01

Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) has proven useful in the diagnosis, staging, and detection of metastasis and posttreatment monitoring of several malignancies in human immunodeficiency virus (HIV)-infected patients. It also has the ability to make the important distinction between malignancy and infection in the evaluation of central nervous system (CNS) lesions, leading to the initiation of the appropriate treatment and precluding the need for invasive biopsy. We report an interesting case of HIV positive 35-year-old woman presented with headache, disorientation, and decreased level of consciousness. She underwent whole body PET/CT which showed multiple lesions in the cerebrum which mimics bilateral eye in brain. A diagnosis of a primary CNS lymphoma was made and patient was started on chemotherapy.

Change in the diagnosis from classical Hodgkin's lymphoma to anaplastic large cell lymphoma by (18)F flourodeoxyglucose positron emission tomography/computed tomography: Importance of recognising disease pattern on imaging and immunohistochemistry.

PubMed

Senthil, Raja; Mohapatra, Ranjan Kumar; Sampath, Mouleeswaran Koramadai; Sundaraiya, Sumati

2016-01-01

Anaplastic large cell lymphoma (ALCL) is a rare type of nonHodgkin's lymphoma (NHL), but one of the most common subtypes of T-cell lymphoma. It is an aggressive T-cell lymphoma, and some ALCL may mimic less aggressive classical HL histopathlogically. It may be misdiagnosed unless careful immunohistochemical examination is performed. As the prognosis and management of these two lymphomas vary significantly, it is important to make a correct diagnosis. We describe a case who was diagnosed as classical HL by histopathological examination of cervical lymph node, in whom (18)F-flouro deoxyglucose positron emission tomography/computed tomography appearances were unusual for HL and warranted review of histopathology that revealed anaplastic lymphoma kinase-1 negative anaplastic large T-cell lymphoma, Hodgkin-like variant, thereby changing the management.

False-positive 18F-fluorodeoxyglucose positron emission tomography/computed tomography in a patient with metallic implants following chondrosarcoma resection

PubMed Central

ZHOU, PU; TANG, JINLIANG; ZHANG, DONG; LI, GUANGHUI

2016-01-01

Positron emission tomography (PET) with fluorine-18-labeled fluorodeoxyglucose (18F-FDG) has been used for the staging and evaluation of recurrence in cancer patients. We herein report a false-positive result of 18F-FDG PET/computed tomography (CT) scan in a patient following chondrosarcoma resection and metallic implanting. A 35-year-old male patient with chondrosarcoma of the left iliac bone underwent radical resection, metal brace implanting and radiotherapy. A high uptake of 18F-FDG was observed in the metallic implants and adjacent tissue during PET/CT scanning in the 5th year of follow-up. Tissue biopsy and follow-up examination identified no tumor recurrence or infection at these sites, suggesting that the results of 18F-FDG PET/CT must be interpreted with caution in cancer patients with metallic implants. PMID:27123290

False-positive 18F-fluorodeoxyglucose positron emission tomography/computed tomography in a patient with metallic implants following chondrosarcoma resection.

PubMed

Zhou, P U; Tang, Jinliang; Zhang, Dong; Li, Guanghui

2016-05-01

Positron emission tomography (PET) with fluorine-18-labeled fluorodeoxyglucose ( 18 F-FDG) has been used for the staging and evaluation of recurrence in cancer patients. We herein report a false-positive result of 18 F-FDG PET/computed tomography (CT) scan in a patient following chondrosarcoma resection and metallic implanting. A 35-year-old male patient with chondrosarcoma of the left iliac bone underwent radical resection, metal brace implanting and radiotherapy. A high uptake of 18 F-FDG was observed in the metallic implants and adjacent tissue during PET/CT scanning in the 5th year of follow-up. Tissue biopsy and follow-up examination identified no tumor recurrence or infection at these sites, suggesting that the results of 18 F-FDG PET/CT must be interpreted with caution in cancer patients with metallic implants.

Bayesian reconstruction and use of anatomical a priori information for emission tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowsher, J.E.; Johnson, V.E.; Turkington, T.G.

1996-10-01

A Bayesian method is presented for simultaneously segmenting and reconstructing emission computed tomography (ECT) images and for incorporating high-resolution, anatomical information into those reconstructions. The anatomical information is often available from other imaging modalities such as computed tomography (CT) or magnetic resonance imaging (MRI). The Bayesian procedure models the ECT radiopharmaceutical distribution as consisting of regions, such that radiopharmaceutical activity is similar throughout each region. It estimates the number of regions, the mean activity of each region, and the region classification and mean activity of each voxel. Anatomical information is incorporated by assigning higher prior probabilities to ECT segmentations inmore » which each ECT region stays within a single anatomical region. This approach is effective because anatomical tissue type often strongly influences radiopharmaceutical uptake. The Bayesian procedure is evaluated using physically acquired single-photon emission computed tomography (SPECT) projection data and MRI for the three-dimensional (3-D) Hoffman brain phantom. A clinically realistic count level is used. A cold lesion within the brain phantom is created during the SPECT scan but not during the MRI to demonstrate that the estimation procedure can detect ECT structure that is not present anatomically.« less

Role for positron emission tomography in skeletal diseases.

PubMed

Duet, Michèle; Pouchot, Jacques; Lioté, Frédéric; Faraggi, Marc

2007-01-01

Imaging plays a prominent role in the diagnosis and management of rheumatic diseases. Conventional imaging methods provide high-resolution structural information but usually fail to distinguish between active lesions and residual changes. Positron emission tomography (PET) with the tracer 18F-fluorodeoxyglucose (18F-FDG) was recently introduced into clinical practice as a means of obtaining information on both structure and metabolic activity. 18F-FDG-PET is widely used in oncology and may be valuable in patients with infections or inflammatory diseases, most notably vasculitis. Although encouraging results have been published, the number of studies remains small, as 18F-FDG-PET is an expensive investigation that is not available everywhere. Further work is needed to determine the cost-effectiveness ratio of 18F-FDG-PET in patients with infections or inflammatory diseases. Imaging plays a prominent role in the diagnosis and management of many musculoskeletal diseases. Although considerable progress has been made recently, the structural information supplied by conventional imaging methods is inadequate in some patients. Positron emission tomography (PET) after injection of 18fluorodeoxyglucose (18F-FDG) provides information on tissue metabolism. The usefulness of 18F-FDG-PET in oncology is now widely recognized. Other uses are emerging, in part thanks to the development of new cameras that combine dedicated detectors and an X-scanner in order to ensure accurate three-dimensional localization of metabolically active lesions. However, the exact role for 18F-FDG-PET needs to be studied in larger populations of patients.

Evaluation of attenuation and scatter correction requirements in small animal PET and SPECT imaging

NASA Astrophysics Data System (ADS)

Konik, Arda Bekir

Positron emission tomography (PET) and single photon emission tomography (SPECT) are two nuclear emission-imaging modalities that rely on the detection of high-energy photons emitted from radiotracers administered to the subject. The majority of these photons are attenuated (absorbed or scattered) in the body, resulting in count losses or deviations from true detection, which in turn degrades the accuracy of images. In clinical emission tomography, sophisticated correction methods are often required employing additional x-ray CT or radionuclide transmission scans. Having proven their potential in both clinical and research areas, both PET and SPECT are being adapted for small animal imaging. However, despite the growing interest in small animal emission tomography, little scientific information exists about the accuracy of these correction methods on smaller size objects, and what level of correction is required. The purpose of this work is to determine the role of attenuation and scatter corrections as a function of object size through simulations. The simulations were performed using Interactive Data Language (IDL) and a Monte Carlo based package, Geant4 application for emission tomography (GATE). In IDL simulations, PET and SPECT data acquisition were modeled in the presence of attenuation. A mathematical emission and attenuation phantom approximating a thorax slice and slices from real PET/CT data were scaled to 5 different sizes (i.e., human, dog, rabbit, rat and mouse). The simulated emission data collected from these objects were reconstructed. The reconstructed images, with and without attenuation correction, were compared to the ideal (i.e., non-attenuated) reconstruction. Next, using GATE, scatter fraction values (the ratio of the scatter counts to the total counts) of PET and SPECT scanners were measured for various sizes of NEMA (cylindrical phantoms representing small animals and human), MOBY (realistic mouse/rat model) and XCAT (realistic human model) digital phantoms. In addition, PET projection files for different sizes of MOBY phantoms were reconstructed in 6 different conditions including attenuation and scatter corrections. Selected regions were analyzed for these different reconstruction conditions and object sizes. Finally, real mouse data from the real version of the same small animal PET scanner we modeled in our simulations were analyzed for similar reconstruction conditions. Both our IDL and GATE simulations showed that, for small animal PET and SPECT, even the smallest size objects (˜2 cm diameter) showed ˜15% error when both attenuation and scatter were not corrected. However, a simple attenuation correction using a uniform attenuation map and object boundary obtained from emission data significantly reduces this error in non-lung regions (˜1% for smallest size and ˜6% for largest size). In lungs, emissions values were overestimated when only attenuation correction was performed. In addition, we did not observe any significant improvement between the uses of uniform or actual attenuation map (e.g., only ˜0.5% for largest size in PET studies). The scatter correction was not significant for smaller size objects, but became increasingly important for larger sizes objects. These results suggest that for all mouse sizes and most rat sizes, uniform attenuation correction can be performed using emission data only. For smaller sizes up to ˜ 4 cm, scatter correction is not required even in lung regions. For larger sizes if accurate quantization needed, additional transmission scan may be required to estimate an accurate attenuation map for both attenuation and scatter corrections.

Brain Positron Emission Tomography-Computed Tomography Gender Differences in Tinnitus Patients.

PubMed

Shlamkovich, Nathan; Gavriel, Haim; Eviatar, Ephraim; Lorberboym, Mordechay; Aviram, Eliad

2016-10-01

Increased metabolism in the left auditory cortex has been reported in tinnitus patients. However, gender difference has not been addressed. To assess the differences in Positron emission tomography-computed tomography (PET-CT) results between the genders in tinnitus patients. Retrospective cohort. Included were patients referred to our clinic between January 2011 and August 2013 who complained of tinnitus and underwent fluorodeoxyglucose (FDG)-PET to assess brain metabolism. Univariate and multivariate nominal logistic regressions were used to evaluate the association between upper temporal gyrus (UTG; right and left) and gender. Included were 140 patients (87 males) with an average age of 52.5 yr (median = 53.1). Bilateral tinnitus was found in 85 patients (60.7%), left sided in 30 (21.4%), and right sided in 21(15%). Increased uptake in the UTG was found in 60% of the patients on either side. Males had a statistically significant increased uptake in the UTG in those with unilateral tinnitus and in the entire population. We present the largest study reported so far on tinnitus patients who have undergone FDG-PET-CT. We found a statistically significant difference between the genders in FDG uptake by the UTG. Further investigations should be undertaken to reveal the etiologies for these differences and to assess different therapeutic protocols according to gender. American Academy of Audiology

In-vivo Diagnosis of Breast Cancer Using Gamma Stimulated Emission Computed Tomography

DTIC Science & Technology

2011-04-01

2006. [9] Floyd CE, Howell CR, Harrawood BP, Crowell AS, Kapadia AJ, Macri R, Xia JQ, Pedroni R, Bowsher J, Kiser MR, Tourassi GD, Tornow W , and...spin-sequence 0-1-2), with emitted gamma-ray energy 3448keV, 2601keV, 2657.562keV. In our simulation, w take tw m jor de-excitation parts into... Walter R, "Neutron Stimulated Emission Computed Tomography of Stable Isotopes," Proceedings of SPIE Medical Imaging 2004, vol. 5368, pp. 248-254. 17

Design, Implementation, and Characterization of a Dedicated Breast Computed Mammo Tomography System for Enhanced Lesion Imaging

DTIC Science & Technology

2007-03-01

common FOV of each system. 64 SPECT System Our current emission tomography system uses a compact 16x20cm 2 field of view Cadmium Zinc Telluride (CZT...Brzymialkiewicz, M.P. Tornai, R.L. McKinley, J.E. Bowsher. “Evaluation of Fully 3D Emission Mammotomography with a Compact Cadmium Zinc Telluride Detector...conclusions. Stacks of breast tissue equivalent plates, each 2.0cm thick (CIRS Inc., Norfolk, VA) having either 100% glandular or 100% adipose composition

Fluorodeoxyglucose Positron Emission Tomography–Computed Tomography in Disseminated Cryptococcosis

PubMed Central

Tripathy, Sarthak; Parida, Girish Kumar; Roy, Shambo Guha; Singhal, Abhinav; Mallick, Saumya Ranjan; Tripathi, Madhavi; Shamim, Shamim Ahmed

2017-01-01

Disseminated cryptococcosis without pulmonary involvement is a very rare phenomenon. Patterns of organ involvement in cryptococcosis resemble various other infective conditions as well as malignant conditions on fluorodeoxyglucose positron emission tomography–computed tomography. We present a case of a 43-year-old male patient who had disseminated cryptococcosis. The rarity of the case being noninvolvement of lungs and meninges and resembling more like lymphoma due to the diffuse involvement of the lymph nodes on both sides of the diaphragm. PMID:29142368

Neurologic applications of positron emission tomography.

PubMed

Lenzi, G L; Pantano, P

1984-11-01

The impact of computerized neuroimaging in the neurologic sciences has been so dramatic that it has completely changed our approach to the individual patient. Further changes may be expected from the newborn positron emission tomography (PET) and nuclear magnetic resonance (NMR) in order to help the reader digest a large bulk of data and fully realize the present state of the art of PET, the authors have shaped this review mainly on results rather than on methods and on published reports rather than on future potential.

Imaging Stem Cells Implanted in Infarcted Myocardium

PubMed Central

Zhou, Rong; Acton, Paul D.; Ferrari, Victor A.

2008-01-01

Stem cell–based cellular cardiomyoplasty represents a promising therapy for myocardial infarction. Noninvasive imaging techniques would allow the evaluation of survival, migration, and differentiation status of implanted stem cells in the same subject over time. This review describes methods for cell visualization using several corresponding noninvasive imaging modalities, including magnetic resonance imaging, positron emission tomography, single-photon emission computed tomography, and bioluminescent imaging. Reporter-based cell visualization is compared with direct cell labeling for short- and long-term cell tracking. PMID:17112999

[Analysis of single-photon emission computed tomography in patients with hypertensive encephalopathy complicated with previous hypertensive crisis].

PubMed

Kustkova, H S

2012-01-01

In cerebrovascular diseases pefuzionnaya single photon emission computed tomography with lipophilic amines used for the diagnosis of functional disorders of cerebral blood flow. Quantitative calculations helps clarify the nature of vascular disease and clarify the adequacy and effectiveness of the treatment. In this modern program for SPECT ensure conduct not only as to the calculation of blood flow, but also make it possible to compute also the absolute values of cerebral blood flow.

Intranasal Nerve Growth Factor administration improves cerebral functions in a child with severe traumatic brain injury: A case report.

PubMed

Chiaretti, Antonio; Conti, Giorgio; Falsini, Benedetto; Buonsenso, Danilo; Crasti, Matteo; Manni, Luigi; Soligo, Marzia; Fantacci, Claudia; Genovese, Orazio; Calcagni, Maria Lucia; Di Giuda, Daniela; Mattoli, Maria Vittoria; Cocciolillo, Fabrizio; Ferrara, Pietro; Ruggiero, Antonio; Staccioli, Susanna; Colafati, Giovanna Stefania; Riccardi, Riccardo

2017-01-01

Nerve growth factor (NGF) promotes neural recovery after experimental traumatic brain injury (TBI) supporting neuronal growth, differentiation and survival of brain cells and up-regulating the neurogenesis-associated protein Doublecortin (DCX). Only a few studies reported NGF administration in paediatric patients with severe TBI. A four-year-old boy in a persistent unresponsive wakefulness syndrome (UWS) was treated with intranasal murine NGF administration 6 months after severe TBI. The patient received four cycles of intranasal NGF (0.1 mg/kg, twice a day for 10 consecutive days). NGF administration improved functional [Positron Emission Tomography/Computed Tomography (PET/CT); Single photon emission/Computed Tomography (SPECT/CT) and Magnetic Resonance Imaging (MRI)] assessment, electrophysiological [Electroencephalogram (EEG) and Visual Evoked Potential (VEP)] studies and clinical conditions. He showed improvements in voluntary movements, facial mimicry, phonation, attention and verbal comprehension, ability to cry, cough reflex, oral motility, feeding capacity, and bowel and urinary functions. After NGF administration, raised levels of both NGF and DCX were found in the cerebrospinal fluid of the patient. No side effects were reported. Although further studies are needed for better understanding the neuroprotective role of this neurotrophin, intranasal NGF administration appears to be a promising and safe rescuing strategy treatment in children with neurological impairment after TBI.

Positron Emission Tomography-Guided, Focal-Dose Escalation Using Intensity-Modulated Radiotherapy for Head and Neck Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madani, Indira; Duthoy, Wim; Derie, Cristina R.N.

2007-05-01

Purpose: To assess the feasibility of intensity-modulated radiotherapy (IMRT) using positron emission tomography (PET)-guided dose escalation, and to determine the maximum tolerated dose in head and neck cancer. Methods and Materials: A Phase I clinical trial was designed to escalate the dose limited to the [{sup 18}-F]fluoro-2-deoxy-D-glucose positron emission tomography ({sup 18}F-FDG-PET)-delineated subvolume within the gross tumor volume. Positron emission tomography scanning was performed in the treatment position. Intensity-modulated radiotherapy with an upfront simultaneously integrated boost was employed. Two dose levels were planned: 25 Gy (level I) and 30 Gy (level II), delivered in 10 fractions. Standard IMRT was appliedmore » for the remaining 22 fractions of 2.16 Gy. Results: Between 2003 and 2005, 41 patients were enrolled, with 23 at dose level I, and 18 at dose level II; 39 patients completed the planned therapy. The median follow-up for surviving patients was 14 months. Two cases of dose-limiting toxicity occurred at dose level I (Grade 4 dermitis and Grade 4 dysphagia). One treatment-related death at dose level II halted the study. Complete response was observed in 18 of 21 (86%) and 13 of 16 (81%) evaluated patients at dose levels I and II (p < 0.7), respectively, with actuarial 1-year local control at 85% and 87% (p n.s.), and 1-year overall survival at 82% and 54% (p = 0.06), at dose levels I and II, respectively. In 4 of 9 patients, the site of relapse was in the boosted {sup 18}F-FDG-PET-delineated region. Conclusions: For head and neck cancer, PET-guided dose escalation appears to be well-tolerated. The maximum tolerated dose was not reached at the investigated dose levels.« less

Early Cardiac Involvement Affects Left Ventricular Longitudinal Function in Females Carrying α-Galactosidase A Mutation: Role of Hybrid Positron Emission Tomography and Magnetic Resonance Imaging and Speckle-Tracking Echocardiography.

PubMed

Spinelli, Letizia; Imbriaco, Massimo; Nappi, Carmela; Nicolai, Emanuele; Giugliano, Giuseppe; Ponsiglione, Andrea; Diomiaiuti, Tommaso Claudio; Riccio, Eleonora; Duro, Giovanni; Pisani, Antonio; Trimarco, Bruno; Cuocolo, Alberto

2018-04-01

Hybrid 18 F-fluorodeoxyglucose (FDG) positron emission tomography and magnetic resonance imaging may differentiate mature fibrosis or scar from fibrosis associated to active inflammation in patients with Anderson-Fabry disease, even in nonhypertrophic stage. This study was designed to compare the results of positron emission tomography and magnetic resonance cardiac imaging with those of speckle-tracking echocardiography in heterozygous Anderson-Fabry disease females. Twenty-four heterozygous females carrying α-galactosidase A mutation and without left ventricular hypertrophy underwent cardiac positron emission tomography and magnetic resonance using 18 F-FDG for glucose uptake and 2-dimensional strain echocardiography. 18 F-FDG myocardial uptake was quantified by measuring the coefficient of variation (COV) of the standardized uptake value using a 17-segment model. Focal 18 F-FDG uptake with COV >0.17 was detected in 13 patients, including 2 patients with late gadolinium enhancement at magnetic resonance. COV was 0.30±0.14 in patients with focal 18 F-FDG uptake and 0.12±0.03 in those without ( P <0.001). Strain echocardiography revealed worse global longitudinal systolic strain in patients with COV >0.17 compared with those with COV ≤0.17 (-18.5±2.7% versus -22.2±1.8%; P =0.024). For predicting COV >0.17, a global longitudinal strain >-19.8% had 77% sensitivity and 91% specificity and a value >2 dysfunctional segments 92% sensitivity and 100% specificity. In females carrying α-galactosidase A mutation, focal 18 F-FDG uptake represents an early sign of disease-related myocardial damage and is associated with impaired left ventricular longitudinal function. These findings support the hypothesis that inflammation plays an important role in glycosphingolipids storage disorders. © 2018 American Heart Association, Inc.

Development of computational small animal models and their applications in preclinical imaging and therapy research.

PubMed

Xie, Tianwu; Zaidi, Habib

2016-01-01

The development of multimodality preclinical imaging techniques and the rapid growth of realistic computer simulation tools have promoted the construction and application of computational laboratory animal models in preclinical research. Since the early 1990s, over 120 realistic computational animal models have been reported in the literature and used as surrogates to characterize the anatomy of actual animals for the simulation of preclinical studies involving the use of bioluminescence tomography, fluorescence molecular tomography, positron emission tomography, single-photon emission computed tomography, microcomputed tomography, magnetic resonance imaging, and optical imaging. Other applications include electromagnetic field simulation, ionizing and nonionizing radiation dosimetry, and the development and evaluation of new methodologies for multimodality image coregistration, segmentation, and reconstruction of small animal images. This paper provides a comprehensive review of the history and fundamental technologies used for the development of computational small animal models with a particular focus on their application in preclinical imaging as well as nonionizing and ionizing radiation dosimetry calculations. An overview of the overall process involved in the design of these models, including the fundamental elements used for the construction of different types of computational models, the identification of original anatomical data, the simulation tools used for solving various computational problems, and the applications of computational animal models in preclinical research. The authors also analyze the characteristics of categories of computational models (stylized, voxel-based, and boundary representation) and discuss the technical challenges faced at the present time as well as research needs in the future.

The Neurobiological Basis of Reading.

ERIC Educational Resources Information Center

Joseph, Jane; Noble, Kimberly; Eden, Guinevere

2001-01-01

This paper reviews studies using positron emission tomography and functional magnetic resonance imaging in adults to study the reading process and notes that general networks of regions seem to be uniquely associated with different components of the reading process. Findings are evaluated in light of technical and experimental limitations and…

Compressive Sampling Based Interior Reconstruction for Dynamic Carbon Nanotube Micro-CT

PubMed Central

Yu, Hengyong; Cao, Guohua; Burk, Laurel; Lee, Yueh; Lu, Jianping; Santago, Pete; Zhou, Otto; Wang, Ge

2010-01-01

In the computed tomography (CT) field, one recent invention is the so-called carbon nanotube (CNT) based field emission x-ray technology. On the other hand, compressive sampling (CS) based interior tomography is a new innovation. Combining the strengths of these two novel subjects, we apply the interior tomography technique to local mouse cardiac imaging using respiration and cardiac gating with a CNT based micro-CT scanner. The major features of our method are: (1) it does not need exact prior knowledge inside an ROI; and (2) two orthogonal scout projections are employed to regularize the reconstruction. Both numerical simulations and in vivo mouse studies are performed to demonstrate the feasibility of our methodology. PMID:19923686

Identification of prefrontal cortex (BA10) activation while performing Stroop test using diffuse optical tomography

NASA Astrophysics Data System (ADS)

Khadka, Sabin; Chityala, Srujan R.; Tian, Fenghua; Liu, Hanli

2011-03-01

Stroop test is commonly used as a behavior-testing tool for psychological examinations that are related to attention and cognitive control of the human brain. Studies have shown activations in Broadmann area 10 (BA10) of prefrontal cortex (PFC) during attention and cognitive process. The use of diffuse optical tomography (DOT) for human brain mapping is becoming more prevalent. In this study we expect to find neural correlates between the performed cognitive tasks and hemodynamic signals detected by a DOT system. Our initial observation showed activation of oxy-hemoglobin concentration in BA 10, which is consistent with some results seen by positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). Our study demonstrates the possibility of combining DOT with Stroop test to quantitatively investigate cognitive functions of the human brain at the prefrontal cortex.

Syntheses of precursors and reference compounds of the melanin-concentrating hormone receptor 1 (MCHR1) tracers [¹¹C]SNAP-7941 and [¹⁸F]FE@SNAP for positron emission tomography.

PubMed

Schirmer, Eva; Shanab, Karem; Datterl, Barbara; Neudorfer, Catharina; Mitterhauser, Markus; Wadsak, Wolfgang; Philippe, Cécile; Spreitzer, Helmut

2013-09-30

The MCH receptor has been revealed as a target of great interest in positron emission tomography imaging. The receptor's eponymous substrate melanin-concentrating hormone (MCH) is a cyclic peptide hormone, which is located predominantly in the hypothalamus with a major influence on energy and weight regulation as well as water balance and memory. Therefore, it is thought to play an important role in the pathophysiology of adiposity, which is nowadays a big issue worldwide. Based on the selective and high-affinity MCH receptor 1 antagonist SNAP-7941, a series of novel SNAP derivatives has been developed to provide different precursors and reference compounds for the radiosyntheses of the novel PET radiotracers [(11)C]SNAP-7941 and [(18)F]FE@SNAP. Positron emission tomography promotes a better understanding of physiologic parameters on a molecular level, thus giving a deeper insight into MCHR1 related processes as adiposity.

Positron emission tomography/computed tomography with 18F-fluorocholine improve tumor staging and treatment allocation in patients with hepatocellular carcinoma.

PubMed

Chalaye, Julia; Costentin, Charlotte E; Luciani, Alain; Amaddeo, Giuliana; Ganne-Carrié, Nathalie; Baranes, Laurence; Allaire, Manon; Calderaro, Julien; Azoulay, Daniel; Nahon, Pierre; Seror, Olivier; Mallat, Ariane; Soussan, Michael; Duvoux, Christophe; Itti, Emmanuel; Nault, Jean Charles

2018-03-06

Hepatocellular carcinoma (HCC) staging according to the Barcelona Clinical Liver Cancer (BCLC) classification is based on conventional imaging. The aim of our study was to assess the impact of dual-tracer 18F-fluorocholine and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) on tumor staging and treatment allocation. A total of 192 dual-tracer PET/CT scans (18F-fluorocholine and 18F-fluorodeoxyglucose PET/CT) were performed in 177 patients with HCC. BCLC staging and treatment proposal were retrospectively collected based on conventional imaging, along with any new lesions detected, and changes in BCLC classification or treatment allocation based on dual-tracer PET/CT. Patients were primarily men (87.5%) with cirrhosis (71%) due to alcohol ± non-alcoholic steatohepatitis (26%), viral infection (62%) or unknown causes (12%). Among 122 patients with PET/CT performed for staging, BCLC stage based on conventional imaging was 0/A in 61 patients (50%), B in 32 patients (26%) and C in 29 patients (24%). Dual-tracer PET/CT detected new lesions in 26 patients (21%), upgraded BCLC staging in 14 (11%) and modified treatment strategy in 17 (14%). In addition, dual-tracer PET/CT modified the final treatment in 4/9 (44%) patients with unexplained elevation of alpha-fetoprotein (AFP), 10/25 patients (40%) with doubtful lesions on conventional imaging and 3/36 patients (8%) waiting for liver transplantation without active HCC after tumor response following bridging therapy. When used for HCC staging, dual-tracer PET/CT enabled BCLC upgrading and treatment modification in 11% and 14% of patients, respectively. Dual-tracer PET/CT might also be useful in specific situations (an unexplained rise in AFP, doubtful lesions or pre-transplant evaluation of patients without active HCC). Using a combination of tracers 18F-fluorocholine and 18F-fluorodeoxyglucose when performing positron emission tomography/computed tomography (PET/CT), often called a PET scan, helps to identify new tumor lesions in patients with hepatocellular carcinoma. This technique enabled staging modification of patients' tumors and led to changes in treatment allocation in certain patients. Copyright © 2018. Published by Elsevier B.V.

The Physics of Physical Examinations.

ERIC Educational Resources Information Center

Patterson, James D.

1989-01-01

Discussed are several topics on medical imaging including x-rays and Computer Assisted Tomography (CAT) scans, magnetic resonance imaging, fiber optics endoscopy, nuclear medicine and bone scans, positron-emission tomography, and ultrasound. The concepts of radiation dosage, electrocardiograms, and laser therapy are included. (YP)

Brain single-photon emission computed tomography in fetal alcohol syndrome: a case report and study implications.

PubMed

Codreanu, Ion; Yang, JiGang; Zhuang, Hongming

2012-12-01

The indications of brain single-photon emission computed tomography (SPECT) in fetal alcohol syndrome are not clearly defined, even though the condition is recognized as one of the most common causes of mental retardation. This article reports a case of a 9-year-old adopted girl with developmental delay, mildly dysmorphic facial features, and behavioral and cognitive abnormalities. Extensive investigations including genetic studies and brain magnetic resonance imaging (MRI) revealed no abnormalities, and a diagnosis of fetal alcohol syndrome was considered since official diagnostic criteria were met. A brain SPECT was requested and showed severely decreased tracer activity in the thalami, basal ganglia, and temporal lobes on both sides, the overall findings being consistent with the established diagnosis of fetal alcohol syndrome. With increasing availability of functional brain imaging, the study indications and possible ethical implications in suspected prenatal alcohol exposure or even before adoption need further consideration. In this patient, SPECT was the only test to yield positive results.

Linearization correction of /sup 99m/Tc-labeled hexamethyl-propylene amine oxime (HM-PAO) image in terms of regional CBF distribution: comparison to C VO2 inhalation steady-state method measured by positron emission tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inugami, A.; Kanno, I.; Uemura, K.

1988-12-01

The radioisotope distribution following intravenous injection of 99mTc-labeled hexamethylpropyleneamine oxime (HM-PAO) in the brain was measured by single photon emission computed tomography (SPECT) and corrected for the nonlinearity caused by differences in net extraction. The linearization correction was based on a three compartment model, and it required a region of reference to normalize the SPECT image in terms of regional cerebral blood flow distribution. Two different regions of reference, the cerebellum and the whole brain, were tested. The uncorrected and corrected HM-PAO images were compared with cerebral blood flow (CBF) image measured by the C VO2 inhalation steady state methodmore » and positron emission tomography (PET). The relationship between uncorrected HM-PAO and PET-CBF showed a correlation coefficient of 0.85 but tended to saturate at high CBF values, whereas it was improved to 0.93 after the linearization correction. The whole-brain normalization worked just as well as normalization using the cerebellum. This study constitutes a validation of the linearization correction and it suggests that after linearization the HM-PAO image may be scaled to absolute CBF by employing a global hemispheric CBF value as measured by the nontomographic TTXe clearance method.« less

18F-FDG PET/CT-based early treatment response evaluation of nanoparticle-assisted photothermal cancer therapy

PubMed Central

Simón, Marina; Melander, Fredrik; Kristensen, Lotte K.; Bendix, Pól M.; Andresen, Thomas L.; Oddershede, Lene B.; Kjaer, Andreas

2017-01-01

Within the field of nanoparticle-assisted photothermal cancer therapy, focus has mostly been on developing novel heat-generating nanoparticles with the right optical and dimensional properties. Comparison and evaluation of their performance in tumor-bearing animals are commonly assessed by changes in tumor volume; however, this is usually a late-occurring event. This study implements 2-deoxy-2-[F-18]fluoro-D-glucose positron emission tomography imaging to perform early evaluation of the treatment outcome of photothermal therapy. Silica-gold nanoshells (NS) are administered intravenously to nude mice bearing human neuroendocrine tumor xenografts and the tumors are irradiated by a near-infrared laser. The animals are positron emission tomography scanned with 2-deoxy-2-[F-18]fluoro-D-glucose one day before and one day after treatment. Using this setup, a significant decrease in tumor uptake of 2-deoxy-2-[F-18]fluoro-D-glucose is found already one day after therapy in the group receiving NS and laser treatment compared to control animals. At this time point no change in tumor volume can be detected. Moreover, the change in tumor uptake, is used to stratify the animals into responders and non-responders, where the responding group matched improved survival. Overall, these findings support the use of 2-deoxy-2-[F-18]fluoro-D-glucose positron emission tomography imaging for preclinical and clinical evaluation and optimization of photothermal therapy. PMID:28542311

18F-FDG PET/CT-based early treatment response evaluation of nanoparticle-assisted photothermal cancer therapy.

PubMed

Norregaard, Kamilla; Jørgensen, Jesper T; Simón, Marina; Melander, Fredrik; Kristensen, Lotte K; Bendix, Pól M; Andresen, Thomas L; Oddershede, Lene B; Kjaer, Andreas

2017-01-01

Within the field of nanoparticle-assisted photothermal cancer therapy, focus has mostly been on developing novel heat-generating nanoparticles with the right optical and dimensional properties. Comparison and evaluation of their performance in tumor-bearing animals are commonly assessed by changes in tumor volume; however, this is usually a late-occurring event. This study implements 2-deoxy-2-[F-18]fluoro-D-glucose positron emission tomography imaging to perform early evaluation of the treatment outcome of photothermal therapy. Silica-gold nanoshells (NS) are administered intravenously to nude mice bearing human neuroendocrine tumor xenografts and the tumors are irradiated by a near-infrared laser. The animals are positron emission tomography scanned with 2-deoxy-2-[F-18]fluoro-D-glucose one day before and one day after treatment. Using this setup, a significant decrease in tumor uptake of 2-deoxy-2-[F-18]fluoro-D-glucose is found already one day after therapy in the group receiving NS and laser treatment compared to control animals. At this time point no change in tumor volume can be detected. Moreover, the change in tumor uptake, is used to stratify the animals into responders and non-responders, where the responding group matched improved survival. Overall, these findings support the use of 2-deoxy-2-[F-18]fluoro-D-glucose positron emission tomography imaging for preclinical and clinical evaluation and optimization of photothermal therapy.

Dynamic Positron Emission Tomography [PET] in Man Using Small Bismuth Germanate Crystals

DOE R&D Accomplishments Database

Derenzo, S. E.; Budinger, T. F.; Huesman, R. H.; Cahoon, J. L.

1982-04-01

Primary considerations for the design of positron emission tomographs for medical studies in humans are the need for high imaging sensitivity, whole organ coverage, good spatial resolution, high maximum data rates, adequate spatial sampling with minimum mechanical motion, shielding against out of plane activity, pulse height discrimination against scattered photons, and timing discrimination against accidental coincidences. We discuss the choice of detectors, sampling motion, shielding, and electronics to meet these objectives.

First-in-Human Positron Emission Tomography Study Using the 18F-αvβ6-Binding-Peptide

ClinicalTrials.gov

2018-03-01

Breast Carcinoma; Colorectal Carcinoma; Lung Carcinoma; Metastatic Malignant Neoplasm in the Breast; Metastatic Malignant Neoplasm in the Colon; Metastatic Malignant Neoplasm in the Lung; Metastatic Malignant Neoplasm in the Rectum; Pancreatic Carcinoma

Pertuzumab and Erlotinib in Patients With Relapsed Non-Small Cell Lung Cancer: A Phase II Study Using 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging

PubMed Central

Mileshkin, Linda; Townley, Peter; Gitlitz, Barbara; Eaton, Keith; Mitchell, Paul; Hicks, Rodney; Wood, Katie; Amler, Lucas; Fine, Bernard M.; Loecke, David; Pirzkall, Andrea

2014-01-01

Background. Combination blockade of human epidermal growth factor receptor (HER) family signaling may confer enhanced antitumor activity than single-agent blockade. We performed a single-arm study of pertuzumab, a monoclonal antibody that inhibits HER2 dimerization, and erlotinib in relapsed non-small cell lung cancer (NSCLC). Methods. Patients received pertuzumab (840-mg loading dose and 420-mg maintenance intravenously every 3 weeks) and erlotinib (150-mg or 100-mg dose orally, daily). The primary endpoint was response rate (RR) by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) at day 56 in all patients and those with EGFR wild-type tumors. Results. Of 41 patients, 28 (68.3%) experienced treatment-related grade ≥3 adverse events, including pneumatosis intestinalis (3 patients), resulting in early cessation of enrollment. Tissue samples from 32 patients showed mutated EGFR status in 9 of 41 (22%) and wild-type EGFR in 23 of 41 (56%). The FDG-PET RR for patients with assessments at day 56 was 19.5% in all patients (n = 41) and 8.7% in patients with wild-type EGFR NSCLC (n = 23). Investigator-assessed computed tomography RR at day 56 was 12.2%. Conclusion. FDG-PET suggests that pertuzumab plus erlotinib is an active combination, but combination therapy was poorly tolerated, which limits its clinical applicability. More research is warranted to identify drug combinations that disrupt HER receptor signaling but that exhibit improved tolerability profiles. PMID:24457379

F-18 fluoride positron emission tomography/computed tomography in the diagnosis of avascular necrosis of the femoral head: Comparison with magnetic resonance imaging

PubMed Central

Gayana, Shankaramurthy; Bhattacharya, Anish; Sen, Ramesh Kumar; Singh, Paramjeet; Prakash, Mahesh; Mittal, Bhagwant Rai

2016-01-01

Objective: Femoral head avascular necrosis (FHAVN) is one of the increasingly common causes of musculoskeletal disability and poses a major diagnostic and therapeutic challenge. Although radiography, scintigraphy, computed tomography (CT), and magnetic resonance imaging (MRI) have been widely used in the diagnosis of FHAVN, positron emission tomography (PET) has recently been evaluated to assess vascularity of the femoral head. In this study, the authors compared F-18 fluoride PET/CT with MRI in the initial diagnosis of FHAVN. Patients and Methods: We prospectively studied 51 consecutive patients with a high clinical suspicion of FHAVN. All patients underwent MRI and F-18 fluoride PET/CT, the time interval between the two scans being 4–10 (mean 8) days. Two nuclear medicine physicians blinded to the MRI report read the PET/CT scans. Clinical assessment was also done. Final diagnoses were made by surgical pathology or clinical and radiologic follow-up. Results: A final diagnosis of avascular necrosis (AVN) was made in 40 patients. MRI was 96.5% sensitive, 100% specific, and 98.03% accurate while PET/CT was 100% sensitive, specific, and accurate in diagnosing FHAVN. The agreement between the two imaging modalities for the diagnosis of AVN was 96.07%. Conclusion: F-18 fluoride PET/CT showed good agreement with MRI in the initial diagnosis of FHAVN and can be better than MRI in detecting early disease. PMID:26917886

Pilot study utilizing Fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography for glycolytic phenotyping of canine mast cell tumors.

PubMed

Griffin, Lynn R; Thamm, Doug H; Selmic, Laura E; Ehrhart, E J; Randall, Elissa

2018-03-23

The goal of this prospective pilot study was to use naturally occurring canine mast cell tumors of various grades and stages as a model for attempting to determine how glucose uptake and markers of biologic behavior are correlated. It was hypothesized that enhanced glucose uptake, as measured by 2-[fluorine-18]fluoro-d-glucose-positron emission tomography/computed tomography (F18 FDG PET-CT), would correlate with histologic grade. Dogs were recruited for this study from a population referred for treatment of cytologically or histologically confirmed mast cell tumors. Patients were staged utilizing standard of care methods (abdominal ultrasound and three view thoracic radiographs), followed by a whole body F18 FDG PET-CT. Results of the F18 FDG PET-CT were analyzed for possible metastasis and standard uptake value maximum (SUV max ) of identified lesions. Incisional or excisional biopsies of the accessible mast cell tumors were obtained and histology performed. Results were then analyzed to look for a possible correlation between the grade of mast cell tumors and SUV max . A total of nine animals were included in the sample. Findings indicated that there was a correlation between grade of mast cell tumors and SUV max as determined by F18 FDG PET-CT (p-value = 0.073, significance ≤ 0.1). Based on the limited power of this study, it is felt that further research to examine the relationship between glucose utilization and biologic aggressiveness in canine mast cell tumors is warranted. This study was unable to show that F18 FDG PET-CT was a better staging tool than standard of care methods. © 2018 American College of Veterinary Radiology.

The neural basis of functional neuroimaging signal with positron and single-photon emission tomography.

PubMed

Sestini, S

2007-07-01

Functional imaging techniques such as positron and single-photon emission tomography exploit the relationship between neural activity, energy demand and cerebral blood flow to functionally map the brain. Despite the fact that neurobiological processes are not completely understood, several results have revealed the signals that trigger the metabolic and vascular changes accompanying variations in neural activity. Advances in this field have demonstrated that release of the major excitatory neurotransmitter glutamate initiates diverse signaling processes between neurons, astrocytes and blood perfusion, and that this signaling is crucial for the occurrence of brain imaging signals. Better understanding of the neural sites of energy consumption and the temporal correlation between energy demand, energy consumption and associated cerebrovascular hemodynamics gives novel insight into the potential of these imaging tools in the study of metabolic neurodegenerative disorders.

Cardiac involvement in facio-scapulo-humeral muscular dystrophy: a family study using Thallium-201 single-photon-emission-computed tomography.

PubMed

Faustmann, P M; Farahati, J; Rupilius, B; Dux, R; Koch, M C; Reiners, C

1996-12-01

Fifteen persons from two consecutive generations of one family affected with facio-scapulo-humeral muscular dystrophy (FSHD) were clinically and neurophysiologically examined. Diagnostic muscle biopsies were obtained from two members. Linkage analysis showed that all four affected members of the family inherit the same 4q35 haplotype giving a lod score of z = +1.44. Six family members were examined by ECG at rest and under stress, by two-dimensional echocardiography, and by cardiac Thallium-201 single-photon-emission computed tomography (Tl-201-SPECT) under dobutamine stress and at rest. Abnormal reduced Tl-201 uptake in cardiac SPECT was only found in the affected members of the family. Therefore we suggest that cardiac Tl-201-SPECT abnormalities in FSHD reflect cardiomyogenic changes in this type of muscular disease.

Evaluation of 18-F-fluoro-2-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) as a staging and monitoring tool for dogs with stage-2 splenic hemangiosarcoma - A pilot study.

PubMed

Borgatti, Antonella; Winter, Amber L; Stuebner, Kathleen; Scott, Ruth; Ober, Christopher P; Anderson, Kari L; Feeney, Daniel A; Vallera, Daniel A; Koopmeiners, Joseph S; Modiano, Jaime F; Froelich, Jerry

2017-01-01

Positron Emission Tomography-Computed Tomography (PET-CT) is routinely used for staging and monitoring of human cancer patients and is becoming increasingly available in veterinary medicine. In this study, 18-fluorodeoxyglucose (18FDG)-PET-CT was used in dogs with naturally occurring splenic hemangiosarcoma (HSA) to assess its utility as a staging and monitoring modality as compared to standard radiography and ultrasonography. Nine dogs with stage-2 HSA underwent 18FDG-PET-CT following splenectomy and prior to commencement of chemotherapy. Routine staging (thoracic radiography and abdominal ultrasonography) was performed prior to 18FDG-PET-CT in all dogs. When abnormalities not identified on routine tests were noted on 18FDG-PET-CT, owners were given the option to repeat a PET-CT following treatment with eBAT. A PET-CT scan was repeated on Day 21 in three dogs. Abnormalities not observed on conventional staging tools, and most consistent with malignant disease based on location, appearance, and outcome, were detected in two dogs and included a right atrial mass and a hepatic nodule, respectively. These lesions were larger and had higher metabolic activity on the second scans. 18FDG-PET-CT has potential to provide important prognostic information and influence treatment recommendations for dogs with stage-2 HSA. Additional studies will be needed to precisely define the value of this imaging tool for staging and therapy monitoring in dogs with this and other cancers.

Evaluation of 18-F-fluoro-2-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) as a staging and monitoring tool for dogs with stage-2 splenic hemangiosarcoma – A pilot study

PubMed Central

Winter, Amber L.; Stuebner, Kathleen; Scott, Ruth; Ober, Christopher P.; Anderson, Kari L.; Feeney, Daniel A.; Vallera, Daniel A.; Koopmeiners, Joseph S.; Modiano, Jaime F.; Froelich, Jerry

2017-01-01

Positron Emission Tomography-Computed Tomography (PET-CT) is routinely used for staging and monitoring of human cancer patients and is becoming increasingly available in veterinary medicine. In this study, 18-fluorodeoxyglucose (18FDG)-PET-CT was used in dogs with naturally occurring splenic hemangiosarcoma (HSA) to assess its utility as a staging and monitoring modality as compared to standard radiography and ultrasonography. Nine dogs with stage-2 HSA underwent 18FDG-PET-CT following splenectomy and prior to commencement of chemotherapy. Routine staging (thoracic radiography and abdominal ultrasonography) was performed prior to 18FDG-PET-CT in all dogs. When abnormalities not identified on routine tests were noted on 18FDG-PET-CT, owners were given the option to repeat a PET-CT following treatment with eBAT. A PET-CT scan was repeated on Day 21 in three dogs. Abnormalities not observed on conventional staging tools, and most consistent with malignant disease based on location, appearance, and outcome, were detected in two dogs and included a right atrial mass and a hepatic nodule, respectively. These lesions were larger and had higher metabolic activity on the second scans. 18FDG-PET-CT has potential to provide important prognostic information and influence treatment recommendations for dogs with stage-2 HSA. Additional studies will be needed to precisely define the value of this imaging tool for staging and therapy monitoring in dogs with this and other cancers. PMID:28222142

Radiation dose to radiosensitive organs in PET/CT myocardial perfusion examination using versatile optical fibre

NASA Astrophysics Data System (ADS)

Salasiah, M.; Nordin, A. J.; Fathinul Fikri, A. S.; Hishar, H.; Tamchek, N.; Taiman, K.; Ahmad Bazli, A. K.; Abdul-Rashid, H. A.; Mahdiraji, G. A.; Mizanur, R.; Noor, Noramaliza M.

2013-05-01

Cardiac positron emission tomography (PET) provides a precise method in order to diagnose obstructive coronary artery disease (CAD), compared to single photon emission tomography (SPECT). PET is suitable for obese and patients who underwent pharmacologic stress procedures. It has the ability to evaluate multivessel coronary artery disease by recording changes in left ventricular function from rest to peak stress and quantifying myocardial perfusion (in mL/min/g of tissue). However, the radiation dose to the radiosensitive organs has become crucial issues in the Positron Emission Tomography/Computed Tomography(PET/CT) scanning procedure. The objective of this study was to estimate radiation dose to radiosensitive organs of patients who underwent PET/CT myocardial perfusion examination at Centre for Diagnostic Nuclear Imaging, Universiti Putra Malaysia in one month period using versatile optical fibres (Ge-B-doped Flat Fibre) and LiF (TLD-100 chips). All stress and rest paired myocardial perfusion PET/CT scans will be performed with the use of Rubidium-82 (82Rb). The optic fibres were loaded into plastic capsules and attached to patient's eyes, thyroid and breasts prior to the infusion of 82Rb, to accommodate the ten cases for the rest and stress PET scans. The results were compared with established thermoluminescence material, TLD-100 chips. The result shows that radiation dose given by TLD-100 and Germanium-Boron-doped Flat Fiber (Ge-B-doped Flat Fiber) for these five organs were comparable to each other where the p>0.05. For CT scans,thyroid received the highest dose compared to other organs. Meanwhile, for PET scans, breasts received the highest dose.

Tunable Emission Wavelength Stacked InAs/GaAs Quantum Dots by Chemical Beam Epitaxy for Optical Coherence Tomography

PubMed Central

Ilahi, Bouraoui; Zribi, Jihene; Guillotte, Maxime; Arès, Richard; Aimez, Vincent; Morris, Denis

2016-01-01

We report on Chemical Beam Epitaxy (CBE) growth of wavelength tunable InAs/GaAs quantum dots (QD) based superluminescent diode’s active layer suitable for Optical Coherence Tomography (OCT). The In-flush technique has been employed to fabricate QD with controllable heights, from 5 nm down to 2 nm, allowing a tunable emission band over 160 nm. The emission wavelength blueshift has been ensured by reducing both dots’ height and composition. A structure containing four vertically stacked height-engineered QDs have been fabricated, showing a room temperature broad emission band centered at 1.1 µm. The buried QD layers remain insensitive to the In-flush process of the subsequent layers, testifying the reliability of the process for broadband light sources required for high axial resolution OCT imaging. PMID:28773633

Efficacy, Predictive Factors, and Prediction Nomograms for 68Ga-labeled Prostate-specific Membrane Antigen-ligand Positron-emission Tomography/Computed Tomography in Early Biochemical Recurrent Prostate Cancer After Radical Prostatectomy.

PubMed

Rauscher, Isabel; Düwel, Charlotte; Haller, Bernhard; Rischpler, Christoph; Heck, Matthias M; Gschwend, Jürgen E; Schwaiger, Markus; Maurer, Tobias; Eiber, Matthias

2018-05-01

Recently, 68 Ga-labeled prostate-specific membrane antigen (PSMA)-ligand positron-emission tomography (PET) imaging has been shown to improve detection rates in recurrent prostate cancer (PC). However, published studies include only small patient numbers at low prostate-specific antigen (PSA) values. For this study, 272 consecutive patients with biochemical recurrence after radical prostatectomy and PSA value between 0.2 and 1ng/ml were included. The 68 Ga-PSMA-ligand PET/computed tomography (CT) was evaluated, and detection rates were determined and correlated to various clinical variables using univariate and multivariable analyses. Subgroups of patients with very low (0.2-0.5ng/ml) and low (>0.5-1.0ng/ml) PSA values were analyzed. In total, lesions indicative of PC recurrence were detected in 55% (74/134) and 74% (102/138) with very low and low PSA values, respectively. Main sites of recurrence were pelvic or retroperitoneal lymph nodes metastases, followed by local recurrence and bone metastases with higher probability in the low versus very low PSA subgroup. Detection rates significantly increased with higher PSA values, primary pT≥3a, primary pN+ disease, grade group ≥4, previous radiation therapy, and concurrent androgen deprivation therapy (ADT) in univariate analysis. In a multivariable logistic regression model, concurrent ADT and PSA values were identified as most relevant predictors of positive 68 Ga-PSMA-ligand PET/CT. Further, prediction nomograms were established, which may help in estimating pretest PSMA-ligand PET positivity in clinical practice. In our study, 68 Ga-labeled prostate-specific membrane antigen (PSMA)-ligand positron-emission tomography (PET)/computed tomography (CT) detected recurrent disease after radical prostatectomy in 55% (74/134) and 74% (102/138) of patients with very low (0.2-0.5ng/ml) and low (>0.5-1.0ng/ml) prostate-specific antigen values, respectively. On the basis of these data, it seems reasonable to perform 68 Ga-PSMA-ligand PET/CT also in patients with early biochemical recurrence, as it can tailor further therapy decisions (eg, local vs systemic treatment). The established prediction nomograms can further assist urologists in discussions on the use of 68 Ga-PSMA-ligand PET/CT with their patients in specific clinical settings. Copyright © 2018 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Brain Mapping of Language and Auditory Perception in High-Functioning Autistic Adults: A PET Study.

ERIC Educational Resources Information Center

Muller, R-A.; Behen, M. E.; Rothermel, R. D.; Chugani, D. C.; Muzik, O.; Mangner, T. J.; Chugani, H. T.

1999-01-01

A study used positron emission tomography (PET) to study patterns of brain activation during auditory processing in five high-functioning adults with autism. Results found that participants showed reversed hemispheric dominance during the verbal auditory stimulation and reduced activation of the auditory cortex and cerebellum. (CR)

Anterior Medial Temporal Lobe Activation during Encoding of Words: FMRI Methods to Optimize Sensitivity

ERIC Educational Resources Information Center

Parsons, Michael W.; Haut, Marc W.; Lemieux, Susan K.; Moran, Maria T.; Leach, Sharon G.

2006-01-01

The existence of a rostrocaudal gradient of medial temporal lobe (MTL) activation during memory encoding has historically received support from positron emission tomography studies, but less so from functional MRI (FMRI) studies. More recently, FMRI studies have demonstrated that characteristics of the stimuli can affect the location of activation…

42 CFR 414.68 - Imaging accreditation.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) Computed tomography. (iii) Nuclear medicine. (iv) Positron emission tomography. CMS-approved accreditation... if CMS takes an adverse action based on accreditation findings. (vi) Notify CMS, in writing... organization must permit its surveyors to serve as witnesses if CMS takes an adverse action based on...

42 CFR 414.68 - Imaging accreditation.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Computed tomography. (iii) Nuclear medicine. (iv) Positron emission tomography. CMS-approved accreditation... if CMS takes an adverse action based on accreditation findings. (vi) Notify CMS, in writing... organization must permit its surveyors to serve as witnesses if CMS takes an adverse action based on...

42 CFR 414.68 - Imaging accreditation.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) Computed tomography. (iii) Nuclear medicine. (iv) Positron emission tomography. CMS-approved accreditation... if CMS takes an adverse action based on accreditation findings. (vi) Notify CMS, in writing... organization must permit its surveyors to serve as witnesses if CMS takes an adverse action based on...

5-HT(1A) receptor binding in euthymic bipolar patients using positron emission tomography with [carbonyl-(11)C]WAY-100635.

PubMed

Sargent, Peter A; Rabiner, Eugenii A; Bhagwagar, Zubin; Clark, Luke; Cowen, Philip; Goodwin, Guy M; Grasby, Paul M

2010-06-01

This study was undertaken to examine whether brain 5-HT(1A) receptor binding is reduced in euthymic bipolar patients. Eight medicated euthymic bipolar patients and 8 healthy volunteers underwent positron emission tomography scanning using the selective 5-HT(1A) receptor radioligand [carbonyl-(11)C]WAY-100635. No significant difference in global postsynaptic parametric binding potential (BP(ND)) was found between euthymic bipolar patients (mean + or - SD, 4.24 + or - 0.76) and healthy volunteers (mean + or - SD, 4.34 + or - 0.86). Ninety five percent Confidence Intervals for the difference in group mean global postsynaptic BP(ND) were -0.77 to 0.97. Analysis of regional BP(ND) did not reveal regional differences between patients and healthy controls. The number of subjects studied was limited and all subjects were on medication. In contrast to previous findings of reduced 5-HT(1A) receptor binding in untreated unipolar and bipolar depressed patients [Sargent, P.A., Kjaer, K.H., Bench, C.J., Rabiner, E.A., Messa, C., Meyer, J., Gunn, R.N., Grasby, P.M., Cowen, P.J., 2000. Brain serotonin1A receptor binding measured by positron emission tomography with [(11)C]WAY-100635: effects of depression and antidepressant treatment. Arch. Gen. Psychiatry 57, 174-180]; [Drevets, W.C., Frank, E., Price, J.C., Kupfer, D.J., Holt, D., Greer, P.J., Huang, Y., Gautier, C., Mathis, C., 1999. PET imaging of serotonin1A receptor binding in depression. Biol. Psychiatry 46, 1375-1387] and in recovered unipolar depressed patients [Bhagwagar, Z., Rabiner, E.A., Sargent, P.A., Grasby, P.M., Cowen, P.J., 2004. Persistent reduction in brain serotonin1A receptor binding in recovered depressed men measured by positron emission tomography with [(11)C]WAY-100635. Mol. Psychiatry 9, 386-92], this study found no difference in 5-HT(1A) receptor BP(ND) between medicated euthymic bipolar patients and healthy controls. Normal 5-HT(1A) receptor BP(ND) in these patients may be a result of drug treatment or could indicate that reduced 5-HT(1A) receptor binding is specific to the depressed state in bipolar patients. Copyright 2009 Elsevier B.V. All rights reserved.

Does Regional Lung Strain Correlate With Regional Inflammation in Acute Respiratory Distress Syndrome During Nonprotective Ventilation? An Experimental Porcine Study.

PubMed

Retamal, Jaime; Hurtado, Daniel; Villarroel, Nicolás; Bruhn, Alejandro; Bugedo, Guillermo; Amato, Marcelo Britto Passos; Costa, Eduardo Leite Vieira; Hedenstierna, Göran; Larsson, Anders; Borges, João Batista

2018-06-01

It is known that ventilator-induced lung injury causes increased pulmonary inflammation. It has been suggested that one of the underlying mechanisms may be strain. The aim of this study was to investigate whether lung regional strain correlates with regional inflammation in a porcine model of acute respiratory distress syndrome. Retrospective analysis of CT images and positron emission tomography images using [F]fluoro-2-deoxy-D-glucose. University animal research laboratory. Seven piglets subjected to experimental acute respiratory distress syndrome and five ventilated controls. Acute respiratory distress syndrome was induced by repeated lung lavages, followed by 210 minutes of injurious mechanical ventilation using low positive end-expiratory pressures (mean, 4 cm H2O) and high inspiratory pressures (mean plateau pressure, 45 cm H2O). All animals were subsequently studied with CT scans acquired at end-expiration and end-inspiration, to obtain maps of volumetric strain (inspiratory volume - expiratory volume)/expiratory volume, and dynamic positron emission tomography imaging. Strain maps and positron emission tomography images were divided into 10 isogravitational horizontal regions-of-interest, from which spatial correlation was calculated for each animal. The acute respiratory distress syndrome model resulted in a decrease in respiratory system compliance (20.3 ± 3.4 to 14.0 ± 4.9 mL/cm H2O; p < 0.05) and oxygenation (PaO2/FIO2, 489 ± 80 to 92 ± 59; p < 0.05), whereas the control animals did not exhibit changes. In the acute respiratory distress syndrome group, strain maps showed a heterogeneous distribution with a greater concentration in the intermediate gravitational regions, which was similar to the distribution of [F]fluoro-2-deoxy-D-glucose uptake observed in the positron emission tomography images, resulting in a positive spatial correlation between both variables (median R = 0.71 [0.02-0.84]; p < 0.05 in five of seven animals), which was not observed in the control animals. In this porcine acute respiratory distress syndrome model, regional lung strain was spatially correlated with regional inflammation, supporting that strain is a relevant and prominent determinant of ventilator-induced lung injury.

Image quality assessment of automatic three-segment MR attenuation correction vs. CT attenuation correction.

PubMed

Partovi, Sasan; Kohan, Andres; Gaeta, Chiara; Rubbert, Christian; Vercher-Conejero, Jose L; Jones, Robert S; O'Donnell, James K; Wojtylak, Patrick; Faulhaber, Peter

2013-01-01

The purpose of this study is to systematically evaluate the usefulness of Positron emission tomography/Magnetic resonance imaging (PET/MRI) images in a clinical setting by assessing the image quality of Positron emission tomography (PET) images using a three-segment MR attenuation correction (MRAC) versus the standard CT attenuation correction (CTAC). We prospectively studied 48 patients who had their clinically scheduled FDG-PET/CT followed by an FDG-PET/MRI. Three nuclear radiologists evaluated the image quality of CTAC vs. MRAC using a Likert scale (five-point scale). A two-sided, paired t-test was performed for comparison purposes. The image quality was further assessed by categorizing it as acceptable (equal to 4 and 5 on the five-point Likert scale) or unacceptable (equal to 1, 2, and 3 on the five-point Likert scale) quality using the McNemar test. When assessing the image quality using the Likert scale, one reader observed a significant difference between CTAC and MRAC (p=0.0015), whereas the other readers did not observe a difference (p=0.8924 and p=0.1880, respectively). When performing the grouping analysis, no significant difference was found between CTAC vs. MRAC for any of the readers (p=0.6137 for reader 1, p=1 for reader 2, and p=0.8137 for reader 3). All three readers more often reported artifacts on the MRAC images than on the CTAC images. There was no clinically significant difference in quality between PET images generated on a PET/MRI system and those from a Positron emission tomography/Computed tomography (PET/CT) system. PET images using the automatic three-segmented MR attenuation method provided diagnostic image quality. However, future research regarding the image quality obtained using different MR attenuation based methods is warranted before PET/MRI can be used clinically.

The use of positron emission tomography in pion radiotherapy.

PubMed

Goodman, G B; Lam, G K; Harrison, R W; Bergstrom, M; Martin, W R; Pate, B D

1986-10-01

The radioactive debris produced by pion radiotherapy can be imaged by the technique of Positron Emission Tomography (PET) as a method of non-invasive in situ verification of the pion treatment. This paper presents the first visualization of the pion stopping distribution within a tumor in a human brain using PET. Together with the tissue functional information provided by the standard PET scans using radiopharmaceuticals, the combination of pion with PET technique can provide a much better form of radiotherapy than the use of conventional radiation in both treatment planning and verification.

[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.

A Dual Modality System for Simultaneous Fluorescence and Positron Emission Tomography Imaging of Small Animals

NASA Astrophysics Data System (ADS)

Liu, Shuangquan; Zhang, Bin; Wang, Xin; Li, Lin; Chen, Yan; Liu, Xin; Liu, Fei; Shan, Baoci; Bai, Jing

2011-02-01

A dual-modality imaging system for simultaneous fluorescence molecular tomography (FMT) and positron emission tomography (PET) of small animals has been developed. The system consists of a noncontact 360°-projection FMT module and a flat panel detector pair based PET module, which are mounted orthogonally for the sake of eliminating cross interference. The FMT images and PET data are simultaneously acquired by employing dynamic sampling mode. Phantom experiments, in which the localization and range of radioactive and fluorescence probes are exactly indicated, have been carried out to verify the feasibility of the system. An experimental tumor-bearing mouse is also scanned using the dual-modality simultaneous imaging system, the preliminary fluorescence tomographic images and PET images demonstrate the in vivo performance of the presented dual-modality system.

Science Based Stockpile Stewardship

DTIC Science & Technology

1994-11-01

camera, and to do tomography from the data. This is a standard medical imaging procedure (SPECT: Single-photon emission com- puted tomography ). We do...interest remain the obser- vations of extremely rare branching ratios of the decays of muons and pions. 4. Accelerator-based Power Sources (APS). The

Comparison of Core-Needle Biopsy and Fine-Needle Aspiration for Evaluating Thyroid Incidentalomas Detected by 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: A Propensity Score Analysis.

PubMed

Suh, Chong Hyun; Choi, Young Jun; Lee, Jong Jin; Shim, Woo Hyun; Baek, Jung Hwan; Chung, Han Cheol; Shong, Young Kee; Song, Dong Eun; Sung, Tae Yon; Lee, Jeong Hyun

2017-10-01

This study used a propensity score analysis to assess the roles of core-needle biopsy (CNB) and fine-needle aspiration (FNA) in the evaluation of thyroid incidentalomas detected on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT). The study population was obtained from a historical cohort who underwent 18 F-FDG PET/CT between October 2008 and September 2015. Patients were included who underwent ultrasound-guided CNB or FNA for incidental focal uptake of 18 F-FDG in the thyroid gland on PET/CT. The primary study outcomes included the inconclusive result rates in the CNB and FNA groups. The secondary outcome measures included the non-diagnostic result rate and the diagnostic performance for neoplasms. Multivariate analysis, propensity score matching, and inverse probability weighting were conducted. A total of 1360 nodules from 1338 patients were included in this study: 859 nodules from 850 patients underwent FNA, and 501 nodules from 488 patients underwent CNB. Compared to FNA, CNB demonstrated a significantly lower inconclusive result rate in the pooled cohort (23.8% vs. 35.4%; p < 0.001), propensity score-matched cohorts (22.9% vs. 36.6%; p < 0.001), and with inverse probability weighting (22.4% vs. 35.2%; p < 0.001). Non-diagnostic result rates were also significantly lower in CNB than in FNA. The diagnostic performance of the two groups in the pooled and matched cohorts was similar, with no significant differences found. The significantly lower inconclusive result rates in CNB than in FNA were consistent within the propensity score-matched cohorts. Therefore, CNB appears to be a promising diagnostic tool for patients with thyroid incidentalomas detected on 18 F-FDG PET/CT.

Applying standardized uptake values in gallium-67-citrate single-photon emission computed tomography/computed tomography studies and their correlation with blood test results in representative organs.

PubMed

Toriihara, Akira; Daisaki, Hiromitsu; Yamaguchi, Akihiro; Yoshida, Katsuya; Isogai, Jun; Tateishi, Ukihide

2018-05-21

Recently, semiquantitative analysis using standardized uptake value (SUV) has been introduced in bone single-photon emission computed tomography/computed tomography (SPECT/CT). Our purposes were to apply SUV-based semiquantitative analytic method for gallium-67 (Ga)-citrate SPECT/CT and to evaluate correlation between SUV of physiological uptake and blood test results in representative organs. The accuracy of semiquantitative method was validated using an National Electrical Manufacturers Association body phantom study (radioactivity ratio of sphere : background=4 : 1). Thereafter, 59 patients (34 male and 25 female; mean age, 66.9 years) who had undergone Ga-citrate SPECT/CT were retrospectively enrolled in the study. A mean SUV of physiological uptake was calculated for the following organs: the lungs, right atrium, liver, kidneys, spleen, gluteal muscles, and bone marrow. The correlation between physiological uptakes and blood test results was evaluated using Pearson's correlation coefficient. The phantom study revealed only 1% error between theoretical and actual SUVs in the background, suggesting the sufficient accuracy of scatter and attenuation corrections. However, a partial volume effect could not be overlooked, particularly in small spheres with a diameter of less than 28 mm. The highest mean SUV was observed in the liver (range: 0.44-4.64), followed by bone marrow (range: 0.33-3.60), spleen (range: 0.52-2.12), and kidneys (range: 0.42-1.45). There was no significant correlation between hepatic uptake and liver function, renal uptake and renal function, or bone marrow uptake and blood cell count (P>0.05). The physiological uptake in Ga-citrate SPECT/CT can be represented as SUVs, which are not significantly correlated with corresponding blood test results.

Contrast-enhanced [18F] fluorodeoxyglucose-positron emission tomography-computed tomography as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin.

PubMed

Jain, Avani; Srivastava, Madhur Kumar; Pawaskar, Alok Suresh; Shelley, Simon; Elangovan, Indirani; Jain, Hasmukh; Pandey, Somnath; Kalal, Shilpa; Amalachandran, Jaykanth

2015-01-01

To evaluate the advantages of contrast enhanced F-18-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-contrast enhanced CT [CECT]) when used as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin (MUO). A total of 243 patients with fine needle aspiration cytology/biopsy proven MUO were included in this prospective study. Patients who were thoroughly evaluated for primary or primary tumor was detected by any other investigation were excluded from the analysis. Totally, 163 patients with pathological diagnosis of malignancy but no apparent sites of the primary tumor were finally selected for analysis. The site of probable primary malignancy suggested by PET-CECT was confirmed by biopsy/follow-up. PET-CECT suggested probable site of primary in 128/163 (78.52%) patients. In 30/35 remaining patients, primary tumor was not detected even after extensive work-up. In 5 patients, where PET-CECT was negative, primary was found on further extensive investigations or follow-up. The sensitivity, specificity, positive predictive value and negative predictive value of the study were 95.76%, 66.67%, 88.28% and 85.71% respectively. F-18 FDG PET-CECT aptly serves the purpose of initial imaging modality owing to high sensitivity, negative and positive predictive value. PET-CECT not only surveys the whole body for the primary malignancy but also stages the disease accurately. Use of contrast improves the diagnostic utility of modality as well as help in staging of the primary tumor. Although benefits of using PET-CECT as initial diagnostic modality are obvious from this study, there is a need for a larger study comparing conventional methods for diagnosing primary in patients with MUO versus PET-CECT.

Micro-positron emission tomography/contrast-enhanced computed tomography imaging of orthotopic pancreatic tumor-bearing mice using the αvβ₃ integrin tracer ⁶⁴Cu-labeled cyclam-RAFT-c(-RGDfK-)₄.

PubMed

Aung, Winn; Jin, Zhao-Hui; Furukawa, Takako; Claron, Michael; Boturyn, Didier; Sogawa, Chizuru; Tsuji, Atsushi B; Wakizaka, Hidekatsu; Fukumura, Toshimitsu; Fujibayashi, Yasuhisa; Dumy, Pascal; Saga, Tsuneo

2013-09-01

The purpose of this study was to develop a clinically relevant orthotopic xenotransplantation model of pancreatic cancer and to perform a preclinical evaluation of a new positron emission tomography (PET) imaging probe, ⁶⁴Cu-labeled cyclam-RAFT-c(-RGDfK-)₄ peptide (⁶⁴Cu-RAFT-RGD), using this model. Varying degrees of αvβ₃ integrin expression in several human pancreatic cancer cell lines were examined by flow cytometry and Western blotting. The cell line BxPC-3, which is stably transfected with a red fluorescence protein (RFP), was used for surgical orthotopic implantation. Orthotopic xenograft was established in the pancreas of recipient nude mice. An in vivo probe biodistribution and receptor blocking study, preclinical PET imaging coregistered with contrast-enhanced computed tomography (CECT) comparing ⁶⁴Cu-RAFT-RGD and ¹⁸F-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) accumulation in tumor, postimaging autoradiography, and histologic and immunohistochemical examinations were done. Biodistribution evaluation with a blocking study confirmed that efficient binding of probe to tumor is highly αvβ₃ integrin specific. ⁶⁴Cu-RAFT-RGD PET combined with CECT provided for precise and easy detection of cancer lesions. Autoradiography, histologic, and immunohistochemical examinations confirmed the accumulation of ⁶⁴Cu-RAFT-RGD in tumor versus nontumor tissues. In comparative PET studies, ⁶⁴Cu-RAFT-RGD accumulation provided better tumor contrast to background than ¹⁸F-FDG. Our results suggest that ⁶⁴Cu-RAFT-RGD PET imaging is potentially applicable for the diagnosis of αvβ₃ integrin-expressing pancreatic tumors.

2-deoxy-2-(18F)fluoro-D-glucose positron emission tomography/computed tomography imaging in paediatric oncology

PubMed Central

Freebody, John; Wegner, Eva A; Rossleigh, Monica A

2014-01-01

Positron emission tomography (PET) is a minimally invasive technique which has been well validated for the diagnosis, staging, monitoring of response to therapy, and disease surveillance of adult oncology patients. Traditionally the value of PET and PET/computed tomography (CT) hybrid imaging has been less clearly defined for paediatric oncology. However recent evidence has emerged regarding the diagnostic utility of these modalities, and they are becoming increasingly important tools in the evaluation and monitoring of children with known or suspected malignant disease. Important indications for 2-deoxy-2-(18F)fluoro-D-glucose (FDG) PET in paediatric oncology include lymphoma, brain tumours, sarcoma, neuroblastoma, Langerhans cell histiocytosis, urogenital tumours and neurofibromatosis type I. This article aims to review current evidence for the use of FDG PET and PET/CT in these indications. Attention will also be given to technical and logistical issues, the description of common imaging pitfalls, and dosimetric concerns as they relate to paediatric oncology. PMID:25349660

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.

Gaussian process tomography for soft x-ray spectroscopy at WEST without equilibrium information

NASA Astrophysics Data System (ADS)

Wang, T.; Mazon, D.; Svensson, J.; Li, D.; Jardin, A.; Verdoolaege, G.

2018-06-01

Gaussian process tomography (GPT) is a recently developed tomography method based on the Bayesian probability theory [J. Svensson, JET Internal Report EFDA-JET-PR(11)24, 2011 and Li et al., Rev. Sci. Instrum. 84, 083506 (2013)]. By modeling the soft X-ray (SXR) emissivity field in a poloidal cross section as a Gaussian process, the Bayesian SXR tomography can be carried out in a robust and extremely fast way. Owing to the short execution time of the algorithm, GPT is an important candidate for providing real-time reconstructions with a view to impurity transport and fast magnetohydrodynamic control. In addition, the Bayesian formalism allows quantifying uncertainty on the inferred parameters. In this paper, the GPT technique is validated using a synthetic data set expected from the WEST tokamak, and the results are shown of its application to the reconstruction of SXR emissivity profiles measured on Tore Supra. The method is compared with the standard algorithm based on minimization of the Fisher information.

Unusual Asymptomatic Fluorodeoxyglucose Avid Pheochromocytoma in a Case of Myxoid Liposarcoma of the Extremity on 18-F Fluorodeoxyglucose Positron Emission Tomography-computed Tomography.

PubMed

Shivdasani, Divya; Singh, Natasha; Pereira, Melvika; Zade, Anand

2017-01-01

Sarcomas are a heterogeneous group of rare tumors and arise either from soft tissue or from bone. Soft-tissue sarcomas (STSs) initially metastasize to the lungs. Metastases to extrapulmonary sites such as liver, brain, and soft tissue distant from primary tumor usually develop later. However, cases with isolated adrenal metastasis without disseminated disease have been reported in literature. We present a case of primary myxoid liposarcoma of the lower limb, in which staging 18 -F fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) scan detected a suspicious FDG avid adrenal lesion which eventually on resection was diagnosed as asymptomatic pheochromocytoma. Pheochromocytomas have been reported to demonstrate FDG uptake mimicking metastasis. Hence, while interpreting FDG PET-CT scans in the context of STSs, both the extrapulmonary metastatic potential of aggressive histological subtypes of sarcoma and rare possibility of FDG avid coexistent benign tumor should be taken into consideration.

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.

Advancements in optical techniques and imaging in the diagnosis and management of bladder cancer.

PubMed

Rose, Tracy L; Lotan, Yair

2018-03-01

Accurate detection and staging is critical to the appropriate management of urothelial cancer (UC). The use of advanced optical techniques during cystoscopy is becoming more widespread to prevent recurrent nonmuscle invasive bladder cancer. Standard of care for muscle-invasive UC includes the use of computed tomography and/or magnetic resonance imaging, but staging accuracy of these tests remains imperfect. Novel imaging modalities are being developed to improve current test performance. Positron emission tomography/computed tomography has a role in the initial evaluation of select patients with muscle-invasive bladder cancer and in disease recurrence in some cases. Several novel immuno-positron emission tomography tracers are currently in development to address the inadequacy of current imaging modalities for monitoring of tumor response to newer immune-based treatments. This review summaries the current standards and recent advances in optical techniques and imaging modalities in localized and metastatic UC. Copyright © 2018 Elsevier Inc. All rights reserved.

Esophageal cancer associated with a sarcoid-like reaction and systemic sarcoidosis in lymph nodes: supportive findings of [18F]-fluorodeoxyglucose positron emission tomography-computed tomography during neoadjuvant therapy.

PubMed

Kishino, Takayoshi; Okano, Keiichi; Ando, Yasuhisa; Suto, Hironobu; Asano, Eisuke; Oshima, Minoru; Fujiwara, Masao; Usuki, Hisashi; Kobara, Hideki; Masaki, Tsutomu; Ibuki, Emi; Kushida, Yoshio; Haba, Reiji; Suzuki, Yasuyuki

2018-06-25

In patients with esophageal cancer, differentiation between lymph node metastasis and lymphadenopathies from sarcoidosis or sarcoid-like reactions of lymph nodes is clinically important. Herein, we report two esophageal cancer cases with lymph node involvement of sarcoid-like reaction or sarcoidosis. One patient received chemotherapy and the other chemoradiotherapy as initial treatments. In both cases, [ 18 F]-fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT) was performed before and after chemo(radio)therapy. After the treatment, FDG uptake was not detected in the primary tumor, but it was slightly reduced in the hilar and mediastinal lymph nodes in both cases. These non-identical responses to chemo(radio)therapy suggest the presence of sarcoid-like reaction of lymph nodes associated with squamous cell carcinoma of the esophagus. Curative surgical resection was performed as treatment. These FDG-PET/CT findings may be helpful to distinguish between metastasis and sarcoidosis-associated lymphadenopathy in esophageal cancer.

The Effect of Glycolytic Modulation in Prostate Cancer

DTIC Science & Technology

2009-11-01

glycolysis to induce cytotox- icity, despite diagnostic studies developing positron emission tomography (PET), which uses a trapped glucose analogue, 2...controlled by androgen ablation therapy or chemotherapy, warranting the study ofnovel approaches. In this regard, recent studies have demonstrated...dependence on glycolysis, supporting arationale for selectivity of abrogating glycolysis in tumor cells compared to normal cells. Additional recent studies

Application of positron emission tomography to neuroimaging in sports sciences.

PubMed

Tashiro, Manabu; Itoh, Masatoshi; Fujimoto, Toshihiko; Masud, Md Mehedi; Watanuki, Shoichi; Yanai, Kazuhiko

2008-08-01

To investigate exercise-induced regional metabolic and perfusion changes in the human brain, various methods are available, such as positron emission tomography (PET), functional magnetic resonance imaging (fMRI), near-infrared spectroscopy (NIRS) and electroencephalography (EEG). In this paper, details of methods of metabolic measurement using PET, [(18)F]fluorodeoxyglucose ([(18)F]FDG) and [(15)O]radio-labelled water ([(15)O]H(2)O) will be explained. Functional neuroimaging in the field of neuroscience was started in the 1970s using an autoradiography technique on experimental animals. The first human functional neuroimaging exercise study was conducted in 1987 using a rough measurement system known as (133)Xe inhalation. Although the data was useful, more detailed and exact functional neuroimaging, especially with respect to spatial resolution, was achieved by positron emission tomography. Early studies measured the cerebral blood flow changes during exercise. Recently, PET was made more applicable to exercise physiology and psychology by the use of the tracer [(18)F]FDG. This technique allowed subjects to be scanned after an exercise task is completed but still obtain data from the exercise itself, which is similar to autoradiography studies. In this report, methodological information is provided with respect to the recommended protocol design, the selection of the scanning mode, how to evaluate the cerebral glucose metabolism and how to interpret the regional brain activity using voxel-by-voxel analysis and regions of interest techniques (ROI). Considering the important role of exercise in health promotion, further efforts in this line of research should be encouraged in order to better understand health behavior. Although the number of research papers is still limited, recent work has indicated that the [(18)F]FDG-PET technique is a useful tool to understand brain activity during exercise.

The role of 18F-FDG PET/CT in pediatric lymph-node acute lymphoblastic leukemia involvement.

PubMed

Cistaro, Angelina; Saglio, Francesco; Asaftei, Sebastian; Fania, Piercarlo; Berger, Massimo; Fagioli, Franca

2011-01-01

In pediatric oncology, positron emission tomography/computed tomography (PET/CT) is emerging as an essential diagnostic tool in characterizing suspicious neoplastic lesions and staging malignant diseases. Most studies regarding the possible role of FDG-PET/CT in the management of acute lymphoblastic leukemia (ALL) patients are limited to adults. Here we report a pediatric patient with recurrent ALL, in which FDG-PET/CT was used both to define more precisely the cause of lymphadenopathy and to assess the effect of the second-line therapy.

Functional brain imaging and bioacoustics in the Bottlenose dolphins, Tursiops truncatus

NASA Astrophysics Data System (ADS)

Ridgway, Sam; Finneran, James; Carder, Donald; van Bonn, William; Smith, Cynthia; Houser, Dorian; Mattrey, Robert; Hoh, Carl

2003-10-01

The dolphin brain is the central processing computer for a complex and effective underwater echolocation and communication system. Until now, it has not been possible to study or diagnose disorders of the dolphin brain employing modern functional imaging methods like those used in human medicine. Our most recent studies employ established methods such as behavioral tasks, physiological observations, and computed tomography (CT) and, for the first time, single photon emission computed tomography (SPECT), and positron emission tomography (PET). Trained dolphins slide out of their enclosure on to a mat and are transported by trainers and veterinarians to the laboratory for injection of a ligand. Following ligand injection, brief experiments include trained vocal responses to acoustic, visual, or tactile stimuli. We have used the ligand technetium (Tc-99m) biscisate (Neurolite) to image circulatory flow by SPECT. Fluro-deoxy-d-glucose (18-F-FDG) has been employed to image brain metabolism with PET. Veterinarians carefully monitored dolphins during and after the procedure. Through these methods, we have demonstrated that functional imaging can be employed safely and productively with dolphins to obtain valuable information on brain structure and function for medical and research purposes. Hemispheric differences and variations in flow and metabolism in different brain areas will be shown.

Imaging Strategies for Tissue Engineering Applications

PubMed Central

Nam, Seung Yun; Ricles, Laura M.; Suggs, Laura J.

2015-01-01

Tissue engineering has evolved with multifaceted research being conducted using advanced technologies, and it is progressing toward clinical applications. As tissue engineering technology significantly advances, it proceeds toward increasing sophistication, including nanoscale strategies for material construction and synergetic methods for combining with cells, growth factors, or other macromolecules. Therefore, to assess advanced tissue-engineered constructs, tissue engineers need versatile imaging methods capable of monitoring not only morphological but also functional and molecular information. However, there is no single imaging modality that is suitable for all tissue-engineered constructs. Each imaging method has its own range of applications and provides information based on the specific properties of the imaging technique. Therefore, according to the requirements of the tissue engineering studies, the most appropriate tool should be selected among a variety of imaging modalities. The goal of this review article is to describe available biomedical imaging methods to assess tissue engineering applications and to provide tissue engineers with criteria and insights for determining the best imaging strategies. Commonly used biomedical imaging modalities, including X-ray and computed tomography, positron emission tomography and single photon emission computed tomography, magnetic resonance imaging, ultrasound imaging, optical imaging, and emerging techniques and multimodal imaging, will be discussed, focusing on the latest trends of their applications in recent tissue engineering studies. PMID:25012069

Noninvasive imaging of experimental lung fibrosis.

PubMed

Zhou, Yong; Chen, Huaping; Ambalavanan, Namasivayam; Liu, Gang; Antony, Veena B; Ding, Qiang; Nath, Hrudaya; Eary, Janet F; Thannickal, Victor J

2015-07-01

Small animal models of lung fibrosis are essential for unraveling the molecular mechanisms underlying human fibrotic lung diseases; additionally, they are useful for preclinical testing of candidate antifibrotic agents. The current end-point measures of experimental lung fibrosis involve labor-intensive histological and biochemical analyses. These measures fail to account for dynamic changes in the disease process in individual animals and are limited by the need for large numbers of animals for longitudinal studies. The emergence of noninvasive imaging technologies provides exciting opportunities to image lung fibrosis in live animals as often as needed and to longitudinally track the efficacy of novel antifibrotic compounds. Data obtained by noninvasive imaging provide complementary information to histological and biochemical measurements. In addition, the use of noninvasive imaging in animal studies reduces animal usage, thus satisfying animal welfare concerns. In this article, we review these new imaging modalities with the potential for evaluation of lung fibrosis in small animal models. Such techniques include micro-computed tomography (micro-CT), magnetic resonance imaging, positron emission tomography (PET), single photon emission computed tomography (SPECT), and multimodal imaging systems including PET/CT and SPECT/CT. It is anticipated that noninvasive imaging will be increasingly used in animal models of fibrosis to gain insights into disease pathogenesis and as preclinical tools to assess drug efficacy.

The role of fluorine-18-fluorodeoxyglucose positron emission tomography in evaluating the response to tyrosine-kinase inhibitors in patients with metastatic primary renal cell carcinoma.

PubMed

Caldarella, Carmelo; Muoio, Barbara; Isgrò, Maria Antonietta; Porfiri, Emilio; Treglia, Giorgio; Giovanella, Luca

2014-09-01

Positron emission tomography-computed tomography (PET-CT) using fluorodeoxyglucose (FDG) is increasingly used in the evaluation of patients with advanced renal cell carcinoma (RCC), primarily for staging purposes. The aim of this paper is to perform a systematic review about the usefulness of PET-CT using FDG in response assessment after treatment with tyrosine-kinase inhibitors (TKIs) in patients with advanced RCC. The scientific literature about the role of PET-CT using FDG in the assessment of response to treatment with TKIs in patients affected by advanced RCC was systematically reviewed. Seven studies about the role of PET-CT using FDG in the response assessment after treatment with TKIs (essentially sunitinib and sorafenib) in advanced RCC were retrieved in full-text and analysed, to determine the predictive role of this morpho-functional imaging method on patient outcome. To date, the role of PET-CT using FDG in evaluating the response to TKIs in metastatic RCC patients is still not well defined, partly due to heterogeneity of available studies; however, PET-CT reveals potential role for the selection of patients undergoing therapy with TKIs. The use of contrast-enhanced PET-CT appears to be promising for a "multi-dimensional" evaluation of treatment response in these patients.

Nuclear emission-based imaging in the study of brain function

NASA Astrophysics Data System (ADS)

Sossi, Vesna

2016-09-01

Nuclear emission - based imaging has been used in medicine for decades either in the form of Single Photon Emission Computerized Tomography (SPECT) or Positron Emission Tomography (PET). Both techniques are based on radiolabelling molecules of biological interest (radiotracers) with either a gamma (SPECT) or a positron (PET) emitting radionuclide. By detecting radiation from the radiolabels and reconstructing the acquired data it is possible to form an image of the radiotracer distribution in the body and thus obtain information on the biological process that the radiotracer is tagging. While most of the clinical applications of PET are in oncology, where the glucose analogue 18F-flurodeoxyglocose (FDG) is the most commonly used radiotracer, the importance of PET imaging for brain applications is rapidly increasing. Numerous radiotracers exist that can tag different neurotransmitter systems as well as abnormal protein aggregations that are known to underlie several brain diseases: amyloid deposition, a characteristic of Alzheimer's, and, more recently, tau deposition, which is deemed abnormal not only in dementia, but also in Parkinson's syndrome and traumatic brain injury. Imaging has shown that may brain diseases start decades before clinical symptoms, in part explaining the difficulty of developing adequate treatments. This talk will briefly summarize the role of PET imaging in the study of neurodegeneration and discuss the upcoming hybrid PET/MRI imaging instrumentation. NSERC, CIHR, MJFF.

Assessing the role of "bottom-up" emissions and simplified chemical mechanisms in reconciling CESM2.0 with TOGA observations from the ORCAS and ATom-2 campaigns

NASA Astrophysics Data System (ADS)

Asher, E.; Emmons, L. K.; Kinnison, D. E.; Tilmes, S.; Hills, A. J.; Hornbrook, R. S.; Stephens, B. B.; Apel, E. C.

2017-12-01

Surface albedo and precipitation over the Southern Ocean are sensitive to parameterizations of aerosol formation and cloud dynamics in global climate models. Observations of precursor gases for natural aerosols can help constrain the uncertainty in these parameterizations, if used in conjunction with an appropriately simplified chemical mechanism. We implement current oceanic "bottom-up" emission climatologies of dimethyl sulfide (DMS) and isoprene in CESM2.0 (Lana et al. 2016; Archer et al. 2009) and compare modeled constituents from two separate chemical mechanisms with data obtained from the Trace Organic Gas Analyzer (TOGA) on the O2/N2 Ratios and CO2 Airborne Study in the Southern Ocean (ORCAS) and the Atmospheric Tomography Mission 2 (ATom-2). We use ORCAS measurements of DMS, isoprene, methyl vinyl ketone (MVK) and methacrolein (MACR) from over 10 flights in Jan. - Feb. 2016 as a training dataset to improve "bottom-up" emissions. Thereafter, we evaluate the scaled "top-down" emissions in CESM with TOGA data obtained from the Atmospheric Tomography Mission (ATom-2) in Feb. 2017. Recent laboratory studies at NCAR confirm that TOGA surpasses proton transfer reaction mass spectrometry (PTR-MS) and commercial gas chromatography (GC) instruments with respect to accurate measurements of oxygenated VOCs in low nitrogen oxide (NO) environments, such as MVK and MACR.

18F-FDG positron emission tomography/computed tomography in infective endocarditis.

PubMed

Salomäki, Soile Pauliina; Saraste, Antti; Kemppainen, Jukka; Bax, Jeroen J; Knuuti, Juhani; Nuutila, Pirjo; Seppänen, Marko; Roivainen, Anne; Airaksinen, Juhani; Pirilä, Laura; Oksi, Jarmo; Hohenthal, Ulla

2017-02-01

The diagnosis of infective endocarditis (IE), especially the diagnosis of prosthetic valve endocarditis (PVE) is challenging since echocardiographic findings are often scarce in the early phase of the disease. We studied the use of 2-[ 18 F]fluoro-2-deoxy-D-glucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) in IE. Sixteen patients with suspected PVE and 7 patients with NVE underwent visual evaluation of 18 F-FDG-PET/CT. 18 F-FDG uptake was measured also semiquantitatively as maximum standardized uptake value (SUV max ) and target-to-background ratio (TBR). The modified Duke criteria were used as a reference. There was strong, focal 18 F-FDG uptake in the area of the affected valve in all 6 cases of definite PVE, in 3 of 5 possible PVE cases, and in 2 of 5 rejected cases. In all patients with definite PVE, SUV max of the affected valve was higher than 4 and TBR higher than 1.8. In contrast to PVE, only 1 of 7 patients with NVE had uptake of 18 F-FDG by PET/CT in the valve area. Embolic infectious foci were detected in 58% of the patients with definite IE. 18 F-FDG-PET/CT appears to be a sensitive method for the detection of paravalvular infection associated with PVE. Instead, the sensitivity of PET/CT is limited in NVE.

High-Grade Mixed Adenoneuroendocrine Carcinoma in the Cecum: A Case Report

PubMed Central

Shin, Sang Ho; Jung, Sung Hee; Jang, Ji Woong; Kang, Min Seok; Kim, Sang Il; Kim, Ji Hye; Lee, Jun Ho

2017-01-01

Gastrointestinal neoplasms with an exocrine and a neuroendocrine component are rare. Such neoplasms are called “mixed adenoneuroendocrine carcinomas” (MANECs) according to the most recent World Health Organization classification of gastrointestinal tract neoplasms. MANECs have no specific findings that distinguish them from pure adenocarcinomas. In addition, the optimal management strategy of MANECs is largely unknown. We describe the case of a 32-year-old man with dizziness and abdominal bloating. A cecal mass was suspected based on an image study done at a local clinic. We evaluated the cecal mass by using colonoscopy, contrast enhanced computed tomography of the abdomen, positron emission tomography-computed tomography, and laboratory studies. The patient underwent a right hemicolectomy and adjuvant chemotherapy. The final histopathological diagnosis was a high-grade MANEC of the ascending colon, tumor stage T3N2M0. PMID:28289663

Development of computational small animal models and their applications in preclinical imaging and therapy research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Tianwu; Zaidi, Habib, E-mail: habib.zaidi@hcuge.ch; Geneva Neuroscience Center, Geneva University, Geneva CH-1205

The development of multimodality preclinical imaging techniques and the rapid growth of realistic computer simulation tools have promoted the construction and application of computational laboratory animal models in preclinical research. Since the early 1990s, over 120 realistic computational animal models have been reported in the literature and used as surrogates to characterize the anatomy of actual animals for the simulation of preclinical studies involving the use of bioluminescence tomography, fluorescence molecular tomography, positron emission tomography, single-photon emission computed tomography, microcomputed tomography, magnetic resonance imaging, and optical imaging. Other applications include electromagnetic field simulation, ionizing and nonionizing radiation dosimetry, and themore » development and evaluation of new methodologies for multimodality image coregistration, segmentation, and reconstruction of small animal images. This paper provides a comprehensive review of the history and fundamental technologies used for the development of computational small animal models with a particular focus on their application in preclinical imaging as well as nonionizing and ionizing radiation dosimetry calculations. An overview of the overall process involved in the design of these models, including the fundamental elements used for the construction of different types of computational models, the identification of original anatomical data, the simulation tools used for solving various computational problems, and the applications of computational animal models in preclinical research. The authors also analyze the characteristics of categories of computational models (stylized, voxel-based, and boundary representation) and discuss the technical challenges faced at the present time as well as research needs in the future.« less

Maternal high-fat feeding leads to alterations of brain glucose metabolism in the offspring: positron emission tomography study in a porcine model.

PubMed

Sanguinetti, Elena; Liistro, Tiziana; Mainardi, Marco; Pardini, Silvia; Salvadori, Piero A; Vannucci, Alessandro; Burchielli, Silvia; Iozzo, Patricia

2016-04-01

Maternal obesity negatively affects fetal development. Abnormalities in brain glucose metabolism are predictive of metabolic-cognitive disorders. We studied the offspring (aged 0, 1, 6, 12 months) of minipigs fed a normal vs high-fat diet (HFD), by positron emission tomography (PET) to measure brain glucose metabolism, and ex vivo assessments of brain insulin receptors (IRβ) and GLUT4. At birth, brain glucose metabolism and IRβ were twice as high in the offspring of HFD-fed than control mothers. During infancy and youth, brain glucose uptake, GLUT4 and IRβ increased in the offspring of control mothers and decreased in those of HFD-fed mothers, leading to a 40-85% difference (p < 0.05), and severe glycogen depletion, lasting until adulthood. Maternal high-fat feeding leads to brain glucose overexposure during fetal development, followed by long-lasting depression in brain glucose metabolism in minipigs. These features may predispose the offspring to develop metabolic-neurodegenerative diseases.

Single photon emission computed tomography (SPECT) in epilepsy

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 promotedmore » 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.« less

Refraction-compensated motion tracking of unrestrained small animals in positron emission tomography.

PubMed

Kyme, Andre; Meikle, Steven; Baldock, Clive; Fulton, Roger

2012-08-01

Motion-compensated radiotracer imaging of fully conscious rodents represents an important paradigm shift for preclinical investigations. In such studies, if motion tracking is performed through a transparent enclosure containing the awake animal, light refraction at the interface will introduce errors in stereo pose estimation. We have performed a thorough investigation of how this impacts the accuracy of pose estimates and the resulting motion correction, and developed an efficient method to predict and correct for refraction-based error. The refraction model underlying this study was validated using a state-of-the-art motion tracking system. Refraction-based error was shown to be dependent on tracking marker size, working distance, and interface thickness and tilt. Correcting for refraction error improved the spatial resolution and quantitative accuracy of motion-corrected positron emission tomography images. Since the methods are general, they may also be useful in other contexts where data are corrupted by refraction effects. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

New bifunctional chelator for 64Cu-immuno-positron emission tomography.

PubMed

Pandya, Darpan N; Bhatt, Nikunj; Dale, Ajit V; Kim, Jung Young; Lee, Hochun; Ha, Yeong Su; Lee, Ji-Eun; An, Gwang Il; Yoo, Jeongsoo

2013-08-21

A new tetraazamacrocyclic bifunctional chelator, TE2A-Bn-NCS, was synthesized in high overall yield from cyclam. An extra functional group (NCS) was introduced to the N-atom of TE2A for specific conjugation with antibody. The Cu complex of TE2A-Bn-NCS showed high kinetic stability in acidic decomplexation and cyclic voltammetry studies. X-ray structure determination of the Cu-TE2A-Bn-NH2 complex confirmed octahedral geometry, in which copper atom is strongly coordinated by four macrocyclic nitrogens in equatorial positions and two carboxylate oxygen atoms occupy the elongated axial positions. Trastuzumab was conjugated with TE2A-Bn-NCS and then radiolabeled with 64Cu quantitatively at room temperature within 10 min. Biodistribution studies showed that the 64Cu-labeled TE2A-Bn-NCS-trastuzumab conjugates maintain high stability in physiological conditions, and NIH3T6.7 tumors were clearly visualized up to 3 days by 64Cu-immuno-positron emission tomography imaging in animal models.

PET AND SPECT STUDIES IN CHILDREN WITH HEMISPHERIC LOW-GRADE GLIOMAS

PubMed Central

Juhász, Csaba; Bosnyák, Edit

2016-01-01

Molecular imaging is playing an increasing role in the pre-treatment evaluation of low-grade gliomas. While glucose positron emission tomography (PET) can be helpful to differentiate low-grade from high-grade tumors, PET imaging with amino acid radiotracers has several advantages, such as better differentiation between tumors and non-tumorous lesions, optimized biopsy targeting and improved detection of tumor recurrence. This review provides a brief overview of single photon emission computed tomography (SPECT) studies followed by a more detailed review of clinical applications of glucose and amino acid PET imaging in low-grade hemispheric gliomas. We discuss key differences in the performance of the most commonly utilized PET radiotracers and highlight the advantage of PET/MRI fusion to obtain optimal information about tumor extent, heterogeneity and metabolism. Recent data also suggest that simultaneous acquisition of PET/MR images and the combination of advanced MRI techniques with quantitative PET can further improve the pre- and post-treatment evaluation of pediatric brain tumors. PMID:27659825

[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.

PET and SPECT studies in children with hemispheric low-grade gliomas.

PubMed

Juhász, Csaba; Bosnyák, Edit

2016-10-01

Molecular imaging is playing an increasing role in the pretreatment evaluation of low-grade gliomas. While glucose positron emission tomography (PET) can be helpful to differentiate low-grade from high-grade tumors, PET imaging with amino acid radiotracers has several advantages, such as better differentiation between tumors and non-tumorous lesions, optimized biopsy targeting, and improved detection of tumor recurrence. This review provides a brief overview of single-photon emission computed tomography (SPECT) studies followed by a more detailed review of the clinical applications of glucose and amino acid PET imaging in low-grade hemispheric gliomas. We discuss key differences in the performance of the most commonly utilized PET radiotracers and highlight the advantage of PET/MRI fusion to obtain optimal information about tumor extent, heterogeneity, and metabolism. Recent data also suggest that simultaneous acquisition of PET/MR images and the combination of advanced MRI techniques with quantitative PET can further improve the pretreatment and post-treatment evaluation of pediatric brain tumors.

RADIAL COMPUTED TOMOGRAPHY OF AIR CONTAMINANTS USING OPTICAL REMOTE SENSING

EPA Science Inventory

The paper describes the application of an optical remote-sensing (ORS) system to map air contaminants and locate fugitive emissions. Many ORD systems may utilize radial non-overlapping beam geometry and a computed tomography (CT) algorithm to map the concentrations in a plane. In...

Quantification of dopamine transporters in the mouse brain using ultra-high resolution single-photon emission tomography.

PubMed

Acton, Paul D; Choi, Seok-Rye; Plössl, Karl; Kung, Hank F

2002-05-01

Functional imaging of small animals, such as mice and rats, using ultra-high resolution positron emission tomography (PET) and single-photon emission tomography (SPET), is becoming a valuable tool for studying animal models of human disease. While several studies have shown the utility of PET imaging in small animals, few have used SPET in real research applications. In this study we aimed to demonstrate the feasibility of using ultra-high resolution SPET in quantitative studies of dopamine transporters (DAT) in the mouse brain. Four healthy ICR male mice were injected with (mean+/-SD) 704+/-154 MBq [(99m)Tc]TRODAT-1, and scanned using an ultra-high resolution SPET system equipped with pinhole collimators (spatial resolution 0.83 mm at 3 cm radius of rotation). Each mouse had two studies, to provide an indication of test-retest reliability. Reference tissue kinetic modeling analysis of the time-activity data in the striatum and cerebellum was used to quantitate the availability of DAT. A simple equilibrium ratio of striatum to cerebellum provided another measure of DAT binding. The SPET imaging results were compared against ex vivo biodistribution data from the striatum and cerebellum. The mean distribution volume ratio (DVR) from the reference tissue kinetic model was 2.17+/-0.34, with a test-retest reliability of 2.63%+/-1.67%. The ratio technique gave similar results (DVR=2.03+/-0.38, test-retest reliability=6.64%+/-3.86%), and the ex vivo analysis gave DVR=2.32+/-0.20. Correlations between the kinetic model and the ratio technique ( R(2)=0.86, P<0.001) and the ex vivo data ( R(2)=0.92, P=0.04) were both excellent. This study demonstrated clearly that ultra-high resolution SPET of small animals is capable of accurate, repeatable, and quantitative measures of DAT binding, and should open up the possibility of further studies of cerebral binding sites in mice using pinhole SPET.

Colorectal cancer staging: comparison of whole-body PET/CT and PET/MR.

PubMed

Catalano, Onofrio A; Coutinho, Artur M; Sahani, Dushyant V; Vangel, Mark G; Gee, Michael S; Hahn, Peter F; Witzel, Thomas; Soricelli, Andrea; Salvatore, Marco; Catana, Ciprian; Mahmood, Umar; Rosen, Bruce R; Gervais, Debra

2017-04-01

Correct staging is imperative for colorectal cancer (CRC) since it influences both prognosis and management. Several imaging methods are used for this purpose, with variable performance. Positron emission tomography-magnetic resonance (PET/MR) is an innovative imaging technique recently employed for clinical application. The present study was undertaken to compare the staging accuracy of whole-body positron emission tomography-computed tomography (PET/CT) with whole-body PET/MR in patients with both newly diagnosed and treated colorectal cancer. Twenty-six patients, who underwent same day whole-body (WB) PET/CT and WB-PET/MR, were evaluated. PET/CT and PET/MR studies were interpreted by consensus by a radiologist and a nuclear medicine physician. Correlations with prior imaging and follow-up studies were used as the reference standard. Correct staging was compared between methods using McNemar's Chi square test. The two methods were in agreement and correct for 18/26 (69%) patients, and in agreement and incorrect for one patient (3.8%). PET/MR and PET/CT stages for the remaining 7/26 patients (27%) were discordant, with PET/MR staging being correct in all seven cases. PET/MR significantly outperformed PET/CT overall for accurate staging (P = 0.02). PET/MR outperformed PET/CT in CRC staging. PET/MR might allow accurate local and distant staging of CRC patients during both at the time of diagnosis and during follow-up.

[Chilean experience with the use of 18F-deoxyglucose positron emission tomography].

PubMed

Massardo, Teresa; Jofré, M Josefina; Sierralta, Paulina; Canessa, José; González, Patricio; Humeres, Pamela; Valdebenito, Robert

2007-03-01

Clinical oncology is the main application of 18F-deoxyglucose (FDG) positron emission tomography (PET). To evaluate the first 1,000 patients studied with FDG PET in Chile. Retrospective analysis of 1,000 patients (aged between 1 and 94 years, 550 females) studied with FDG PET, since 2003. All studies were performed in a high resolution Siemens Ecat-Exact HR (+). All reports were based on the visual analysis of three plane and three-dimensional images. Ninety seven percent of exams were done for oncological indications, mainly lung lesions, lymphoma, colorectal and gastroesophageal, cancer and breast tumors. Only 1% of patients had brain tumors. Non tumor neurological indications corresponded to 1.7%. Cardiac studies were only 0.3% and inflammatory process corresponded to 1%. The 5.6% corresponded to pediatric population. Six percent of patients were aged less than 18 years and in 50% of them, the indication was oncological, mainly lymphomas, brain tumors, endocrine cancers and sarcomas. The remaining 50% had a neurological indications, mainly for refractory epilepsy. PET FDG imaging was effective in the management of diverse diseases of children and adults.

Estimation of baseline dopamine D2 receptor occupancy in striatum and extrastriatal regions in humans with positron emission tomography with [18F] fallypride.

PubMed

Riccardi, Patrizia; Baldwin, Ron; Salomon, Ronald; Anderson, Sharlet; Ansari, Mohammad S; Li, Rui; Dawant, Benoit; Bauernfeind, Amy; Schmidt, Dennis; Kessler, Robert

2008-01-15

This study examined whether positron emission tomography (PET) studies with [18F] fallypride performed before and after alpha-methyl-para-tyrosine (AMPT) administration can be used to estimate baseline dopamine (DA) D2 receptor occupancy in striatal and extrastriatal regions. Six normal subjects underwent PET with [18 F] fallypride before and after administration of AMPT. The DA D2 receptor binding potentials (bp) were calculated with the reference region method. Percent changes in bp in striatal and extrastriatal regions were calculated with both region-of-interest analysis and on a voxel by voxel basis with parametric images of DA D2 receptor levels. The results of the current study indicate that AMPT treatment significantly increased the bp in the caudate, putamen, ventral striatum, and substantia nigra. A trend level increase was seen in the medial thalamus. This study demonstrates that PET with [18F] fallypride can be used to estimate baseline DA D2 receptor occupancy in striatal and extrastriatal regions.

Integrating Dynamic Positron Emission Tomography and Conventional Pharmacokinetic Studies to Delineate Plasma and Tumor Pharmacokinetics of FAU, a Prodrug Bioactivated by Thymidylate Synthase.

PubMed

Li, Jing; Kim, Seongho; Shields, Anthony F; Douglas, Kirk A; McHugh, Christopher I; Lawhorn-Crews, Jawana M; Wu, Jianmei; Mangner, Thomas J; LoRusso, Patricia M

2016-11-01

FAU, a pyrimidine nucleotide analogue, is a prodrug bioactivated by intracellular thymidylate synthase to form FMAU, which is incorporated into DNA, causing cell death. This study presents a model-based approach to integrating dynamic positron emission tomography (PET) and conventional plasma pharmacokinetic studies to characterize the plasma and tissue pharmacokinetics of FAU and FMAU. Twelve cancer patients were enrolled into a phase 1 study, where conventional plasma pharmacokinetic evaluation of therapeutic FAU (50-1600 mg/m 2 ) and dynamic PET assessment of 18 F-FAU were performed. A parent-metabolite population pharmacokinetic model was developed to simultaneously fit PET-derived tissue data and conventional plasma pharmacokinetic data. The developed model enabled separation of PET-derived total tissue concentrations into the parent drug and metabolite components. The model provides quantitative, mechanistic insights into the bioactivation of FAU and retention of FMAU in normal and tumor tissues and has potential utility to predict tumor responsiveness to FAU treatment. © 2016, The American College of Clinical Pharmacology.

Kinetic filtering of [18F]Fluorothymidine in positron emission tomography studies

NASA Astrophysics Data System (ADS)

Gray, Katherine R.; Contractor, Kaiyumars B.; Kenny, Laura M.; Al-Nahhas, Adil; Shousha, Sami; Stebbing, Justin; Wasan, Harpreet S.; Coombes, R. Charles; Aboagye, Eric O.; Turkheimer, Federico E.; Rosso, Lula

2010-02-01

[18F]Fluorothymidine (FLT) is a cell proliferation marker that undergoes predominantly hepatic metabolism and therefore shows a high level of accumulation in the liver, as well as in rapidly proliferating tumours. Furthermore, the tracer's uptake is substantial in other organs including the heart. We present a nonlinear kinetic filtering technique which enhances the visualization of tumours imaged with FLT positron emission tomography (FLT-PET). A classification algorithm to isolate cancerous tissue from healthy organs was developed and validated using 29 scan data from patients with locally advanced or metastatic breast cancer. A large reduction in signal from the liver and heart of 80% was observed following application of the kinetic filter, whilst the majority of signal from both primary tumours and metastases was retained. A scan acquisition time of 60 min has been shown to be sufficient to obtain the necessary kinetic data. The algorithm extends utility of FLT-PET imaging in oncology research.

Neuroimaging of epilepsy

PubMed Central

Cendes, Fernando; Theodore, William H.; Brinkmann, Benjamin H.; Sulc, Vlastimil; Cascino, Gregory D.

2017-01-01

Imaging is pivotal in the evaluation and management of patients with seizure disorders. Elegant structural neuroimaging with magnetic resonance imaging (MRI) may assist in determining the etiology of focal epilepsy and demonstrating the anatomical changes associated with seizure activity. The high diagnostic yield of MRI to identify the common pathological findings in individuals with focal seizures including mesial temporal sclerosis, vascular anomalies, low-grade glial neoplasms and malformations of cortical development has been demonstrated. Positron emission tomography (PET) is the most commonly performed interictal functional neuroimaging technique that may reveal a focal hypometabolic region concordant with seizure onset. Single photon emission computed tomography (SPECT) studies may assist performance of ictal neuroimaging in patients with pharmacoresistant focal epilepsy being considered for neurosurgical treatment. This chapter highlights neuroimaging developments and innovations, and provides a comprehensive overview of the imaging strategies used to improve the care and management of people with epilepsy. PMID:27430454

Precision control of eluted activity from a Sr/Rb generator for cardiac positron emission tomography.

PubMed

Klein, R; Adler, A; Beanlands, R S; deKemp, R A

2004-01-01

A rubidium-82 (/sup 82/Rb) elution system is described for use with clinical positron emission tomography. The system is self-calibrating with 1.4% repeatability, independent of generator activity and elution flow rate. Saline flow is switched between a /sup 82/Sr//sup 82/Rb generator and a bypass line to achieve a constant activity elution of /sup 82/Rb. In the present study, pulse width modulation (PWM) of a solenoid valve is compared to simple threshold control as a means to simulate a proportional valve. A predictive-corrective control algorithm is developed which produces a constant activity elution within the constraints of long feedback delay and short elution time. Accurate constant-activity elutions of 10-70% of the total generator activity were demonstrated using the threshold comparison control. The adaptive-corrective control of the PWM valve provided a substantial improvement in precision of the steady-state output.

Pituitary adenoma with seizures: PET demonstration of reduced glucose utilization in the medial temporal lobe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bairamian, D.; Di Chiro, G.; Blume, H.

1986-05-01

A patient with a benign chromophobe adenoma, who had incomplete surgical removal followed by radiotherapy, continued to have epileptic seizures up to two or three times a day. She was studied with positron emission tomography using /sup 18/F-2-deoxyglucose (FDG). This technique showed a high level of glucose utilization in the area of the operated tumor but also clear reduction of glucose utilization in the left medial temporal region adjacent to the sella and the scar tissue from the neoplasm. This area of reduced glucose utilization corresponded well to the same finding observed in other patients with complex partial epilepsy. Amore » left temporal anterior lobectomy was carried out followed by improved control of the epilepsy. Positron emission tomography using FDG, together with electrophysiological examinations, may assist in the management of epilepsy related to pituitary tumors.« less

Molecular Imaging of Influenza and Other Emerging Respiratory Viral Infections

PubMed Central

Lawler, James; Paragas, Jason; Jahrling, Peter B.; Mollura, Daniel J.

2011-01-01

Research on the pathogenesis and therapy of influenza and other emerging respiratory viral infections would be aided by methods that directly visualize pathophysiologic processes in patients and laboratory animals. At present, imaging of diseases, such as swine-origin H1N1 influenza, is largely restricted to chest radiograph and computed tomography (CT), which can detect pulmonary structural changes in severely ill patients but are more limited in characterizing the early stages of illness, differentiating inflammation from infection or tracking immune responses. In contrast, imaging modalities, such as positron emission tomography, single photon emission CT, magnetic resonance imaging, and bioluminescence imaging, which have become useful tools for investigating the pathogenesis of a range of disease processes, could be used to advance in vivo studies of respiratory viral infections in patients and animals. Molecular techniques might also be used to identify novel biomarkers of disease progression and to evaluate new therapies. PMID:21422476

Correlated high-resolution x-ray diffraction photoluminescence and atom probe tomography analysis of continuous and discontinuous In xGa 1-xN quantum wells

DOE PAGES

Ren, Xiaochen; Riley, James R.; Koleske, Daniel; ...

2015-07-14

In this study, atom probe tomography (APT) is used to characterize the influence of hydrogen dosing duringGaN barrier growth on the indium distribution of In xGa 1-xN quantum wells, and correlatedmicro-photoluminescence is used to measure changes in the emission spectrum and efficiency. We found that relative to the control growth, hydrogen dosing leads to a 50% increase in emission intensity arising from discontinuous quantum wells that are narrower, of lower indium content, and with more abrupt interfaces. Additionally, simulations of carrier distributions based on APT composition profiles indicate that the greater carrier confinement leads to an increased radiative recombination rate.more » Furthermore, APT analysis of quantum well profiles enables refinement of x-ray diffractionanalysis for more accurate nondestructive measurements of composition.« less

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.

Regional cerebral metabolic alterations in dementia of the Alzheimer type: positron emission tomography with (/sup 18/F)fluorodeoxyglucose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friedland, R.P.; Budinger, T.F.; Ganz, E.

1983-08-01

Alzheimer disease is the most common cause of dementia in adults. Despite recent advances in our understanding of its anatomy and chemistry, we remain largely ignorant of its pathogenesis, physiology, diagnosis, and treatment. Dynamic positron emission tomography using (/sup 18/F)fluorodeoxyglucose (FDG) was performed on the Donner 280-crystal ring in 10 subjects with dementia of the Alzheimer type and six healthy age-matched controls. Ratios comparing mean counts per resolution element in frontal, temporoparietal, and entire cortex regions in brain sections 10 mm thick obtained 40-70 min following FDG injection showed relatively less FDG uptake in the temporoparietal cortex bilaterally in allmore » the Alzheimer subjects (p less than 0.01). Left-right alterations were less prominent than the anteroposterior changes. This diminished uptake was due to lowered rates of FDG use and suggests that the metabolic effects of Alzheimer disease are most concentrated in the temporoparietal cortex. Positron emission tomography is a most powerful tool for the noninvasive in vivo assessment of cerebral pathophysiology in dementia.« less

Higher fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) uptake in tuberculous compared to bacterial spondylodiscitis.

PubMed

Bassetti, Matteo; Merelli, Maria; Di Gregorio, Fernando; Della Siega, Paola; Screm, Maria; Scarparo, Claudio; Righi, Elda

2017-06-01

Tuberculous spondylodiscitis can be difficult to diagnose because of its nonspecific symptoms and the similarities with non-tubercular forms of spinal infection. Fluorine-18-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG PET-CT) is increasingly used for the diagnosis and monitoring of tubercular diseases. Retrospective, case-control study comparing tuberculous spondylodiscitis with biopsy-confirmed pyogenic spondylodiscitis in the period 2010-2012. Ten cases of tuberculous spondylodiscitis and 20 controls were included. Compared to pyogenic, tuberculous spondylodiscitis was more frequent in younger patients (P = 0.01) and was more often associated with thoraco-lumbar tract lesions (P = 0.01) and multiple vertebral involvement (P = 0.01). Significantly higher maximum standardized uptake values (SUV) at FDG-PET were displayed by tuberculous spondylodiscitis compared to controls (12.4 vs. 7.3, P = 0.003). SUV levels above 8 showed the highest value of specificity (0.80). Mean SUV reduction of 48% was detected for tuberculous spondylodiscitis at 1-month follow-up. Higher SUV levels at FDG-PET were detected in tuberculous compared with pyogenic spondylodiscitis. PET-CT use appeared useful in the disease follow-up after treatment initiation.

Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET)/MRI for Lung Cancer Staging.

PubMed

Ohno, Yoshiharu; Koyama, Hisanobu; Lee, Ho Yun; Yoshikawa, Takeshi; Sugimura, Kazuro

2016-07-01

Tumor, lymph node, and metastasis (TNM) classification of lung cancer is typically performed with the TNM staging system, as recommended by the Union Internationale Contre le Cancer (UICC), the American Joint Committee on Cancer (AJCC), and the International Association for the Study of Lung Cancer (IASLC). Radiologic examinations for TNM staging of lung cancer patients include computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography with 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG-PET), and FDG-PET combined with CT (FDG-PET/CT) and are used for pretherapeutic assessments. Recent technical advances in MR systems, application of fast and parallel imaging and/or introduction of new MR techniques, and utilization of contrast media have markedly improved the diagnostic utility of MRI in this setting. In addition, FDG-PET can be combined or fused with MRI (PET/MRI) for clinical practice. This review article will focus on these recent advances in MRI as well as on PET/MRI for lung cancer staging, in addition to a discussion of their potential and limitations for routine clinical practice in comparison with other modalities such as CT, FDG-PET, and PET/CT.

Therapeutic and scintigraphic applications of polymeric micelles: combination of chemotherapy and radiotherapy in hepatocellular carcinoma

PubMed Central

Shih, Ying-Hsia; Peng, Cheng-Liang; Chiang, Ping-Fang; Lin, Wuu-Jyh; Luo, Tsai-Yueh; Shieh, Ming-Jium

2015-01-01

This study evaluated a multifunctional micelle simultaneously loaded with doxorubicin (Dox) and labeled with radionuclide rhenium-188 (188Re) as a combined radiotherapy and chemotherapy treatment for hepatocellular carcinoma. We investigated the single photon emission computed tomography, biodistribution, antitumor efficacy, and pathology of 188Re-Dox micelles in a murine orthotopic luciferase-transfected BNL tumor cells hepatocellular carcinoma model. The single photon emission computed tomography and computed tomography images showed high radioactivity in the liver and tumor, which was in agreement with the biodistribution measured by γ-counting. In vivo bioluminescence images showed the smallest size tumor (P<0.05) in mice treated with the combined micelles throughout the experimental period. In addition, the combined 188Re-Dox micelles group had significantly longer survival compared with the control, 188ReO4 alone (P<0.005), and Dox micelles alone (P<0.01) groups. Pathohistological analysis revealed that tumors treated with 188Re-Dox micelles had more necrotic features and decreased cell proliferation. Therefore, 188Re-Dox micelles may enable combined radiotherapy and chemotherapy to maximize the effectiveness of treatment for hepatocellular carcinoma. PMID:26719687

Value of 18fluorodeoxyglucose-positron-emission tomography in amyotrophic lateral sclerosis: a prospective study.

PubMed

Van Laere, Koen; Vanhee, Annelies; Verschueren, Jolien; De Coster, Liesbeth; Driesen, An; Dupont, Patrick; Robberecht, Wim; Van Damme, Philip

2014-05-01

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder primarily affecting the motor system, with extramotor involvement to a variable extent. Biomarkers for early differential diagnosis and prognosis are needed. An autosomal dominant hexanucleotide (GGGGCC) expansion in the noncoding region of the chromosome 9 open reading frame 72 (C9orf72) gene is the most frequent genetic cause of ALS, but its metabolic pattern has not been studied systematically. To evaluate the use of 18fluorodeoxyglucose-positron-emission tomography as a marker of ALS pathology and investigate whether a specific metabolic signature is present in patients with C9orf72 mutations. In total, 81 patients with a suspected diagnosis of ALS at University Hospital Leuven were prospectively investigated. All underwent detailed neurological examination and electrodiagnostic and genetic testing for the major known genetic causes of ALS (C9orf72, SOD1, TARDBP, and FUS). A diagnosis of ALS was made in 70 of 81 patients. Of these, 11 were C9orf72 positive and 59 were C9orf72 negative. In 7 patients, the diagnosis of primary lateral sclerosis was made; 4 patients had progressive muscular atrophy. A screened healthy control population was used for comparison. Positron-emission tomographic data were spatially normalized and analyzed using a predefined volume of interest and a voxel-based analysis (SPM8). Discriminant analysis was done both volume of interest based and voxel based using a support vector machine approach. Compared with control participants, 18fluorodeoxyglucose-positron-emission tomography showed perirolandic and variable prefrontal hypometabolism in most patients. Patients with primary lateral sclerosis showed a similar pattern. Patients with C9orf72-positive ALS had discrete relative hypometabolism in the thalamus and posterior cingulate compared with those with C9orf72-negative ALS. A posteriori-corrected discriminant analysis was able to correctly classify 95% of ALS cases and 71% of primary lateral sclerosis cases. Prefrontal hypometabolism was associated with reduced clinical functioning (ALS Functional Rating Scale). Extensive hypometabolism in the prefrontal or anterior temporal areas was present in 10% of patients and associated with significantly shorter survival as an independent factor (n = 63, P < .001). Patients who were C9orf72 positive did not differ in survival compared with those who were C9orf72 negative. 18Fluorodeoxyglucose-positron-emission tomography is a useful early diagnostic and prognostic marker for ALS. Amyotrophic lateral sclerosis that is positive for C9orf72 is characterized by only mild cerebral metabolic differences that show no prognostic difference.

Ionospheric-thermospheric UV tomography: 3. A multisensor technique for creating full-orbit reconstructions of atmospheric UV emission

NASA Astrophysics Data System (ADS)

Hei, Matthew A.; Budzien, Scott A.; Dymond, Kenneth F.; Nicholas, Andrew C.; Paxton, Larry J.; Schaefer, Robert K.; Groves, Keith M.

2017-07-01

We present the Volume Emission Rate Tomography (VERT) technique for inverting satellite-based, multisensor limb and nadir measurements of atmospheric ultraviolet emission to create whole-orbit reconstructions of atmospheric volume emission rate. The VERT approach is more general than previous ionospheric tomography methods because it can reconstruct the volume emission rate field irrespective of the particular excitation mechanisms (e.g., radiative recombination, photoelectron impact excitation, and energetic particle precipitation in auroras); physical models are then applied to interpret the airglow. The technique was developed and tested using data from the Special Sensor Ultraviolet Limb Imager and Special Sensor Ultraviolet Spectrographic Imager instruments aboard the Defense Meteorological Satellite Program F-18 spacecraft and planned for use with upcoming remote sensing missions. The technique incorporates several features to optimize the tomographic solutions, such as the use of a nonnegative algorithm (Richardson-Lucy, RL) that explicitly accounts for the Poisson statistics inherent in optical measurements, capability to include extinction effects due to resonant scattering and absorption of the photons from the lines of sight, a pseudodiffusion-based regularization scheme implemented between iterations of the RL code to produce smoother solutions, and the capability to estimate error bars on the solutions. Tests using simulated atmospheric emissions verify that the technique performs well in a variety of situations, including daytime, nighttime, and even in the challenging terminator regions. Lastly, we consider ionospheric nightglow and validate reconstructions of the nighttime electron density against Advanced Research Project Agency (ARPA) Long-range Tracking and Identification Radar (ALTAIR) incoherent scatter radar data.

Predicted extracapsular invasion of hilar lymph node metastasis by fusion positron emission tomography/computed tomography in patients with lung cancer

PubMed Central

MAKINO, TAKASHI; HATA, YOSHINOBU; OTSUKA, HAJIME; KOEZUKA, SATOSHI; ISOBE, KAZUTOSHI; TOCHIGI, NOBUMI; SHIRAGA, NOBUYUKI; SHIBUYA, KAZUTOSHI; HOMMA, SAKAE; IYODA, AKIRA

2015-01-01

Intraoperative detection of hilar lymph node metastasis, particularly with extracapsular invasion, may affect the surgical procedure in patients with lung cancer, as the preoperative estimation of hilar lymph node metastasis is unsatisfactory. The aim of this study was to investigate whether fusion positron emission tomography/computed tomography (PET/CT) is able to predict extracapsular invasion of hilar lymph node metastasis. Between April, 2007 and April, 2013, 509 patients with primary lung cancer underwent surgical resection at our institution, among whom 28 patients exhibiting hilar lymph node metastasis (at stations 10 and 11) were enrolled in this study. A maximum lymph node standardized uptake value of >2.5 in PET scans was interpreted as positive. A total of 17 patients had positive preoperative PET/CT findings in their hilar lymph nodes, while the remaining 11 had negative findings. With regard to extracapsular nodal invasion, the PET/CT findings (P=0.0005) and the histological findings (squamous cell carcinoma, P=0.05) were found to be significant predictors in the univariate analysis. In the multivariate analysis, the PET/CT findings were the only independent predictor (P=0.0004). The requirement for extensive pulmonary resection (sleeve lobectomy, bilobectomy or pneumonectomy) was significantly more frequent in the patient group with positive compared with the group with negative PET/CT findings (76 vs. 9%, respectively, P=0.01). Therefore, the PET/CT findings in the hilar lymph nodes were useful for the prediction of extracapsular invasion and, consequently, for the estimation of possible extensive pulmonary resection. PMID:26623046

Predicted extracapsular invasion of hilar lymph node metastasis by fusion positron emission tomography/computed tomography in patients with lung cancer.

PubMed

Makino, Takashi; Hata, Yoshinobu; Otsuka, Hajime; Koezuka, Satoshi; Isobe, Kazutoshi; Tochigi, Nobumi; Shiraga, Nobuyuki; Shibuya, Kazutoshi; Homma, Sakae; Iyoda, Akira

2015-09-01

Intraoperative detection of hilar lymph node metastasis, particularly with extracapsular invasion, may affect the surgical procedure in patients with lung cancer, as the preoperative estimation of hilar lymph node metastasis is unsatisfactory. The aim of this study was to investigate whether fusion positron emission tomography/computed tomography (PET/CT) is able to predict extracapsular invasion of hilar lymph node metastasis. Between April, 2007 and April, 2013, 509 patients with primary lung cancer underwent surgical resection at our institution, among whom 28 patients exhibiting hilar lymph node metastasis (at stations 10 and 11) were enrolled in this study. A maximum lymph node standardized uptake value of >2.5 in PET scans was interpreted as positive. A total of 17 patients had positive preoperative PET/CT findings in their hilar lymph nodes, while the remaining 11 had negative findings. With regard to extracapsular nodal invasion, the PET/CT findings (P=0.0005) and the histological findings (squamous cell carcinoma, P=0.05) were found to be significant predictors in the univariate analysis. In the multivariate analysis, the PET/CT findings were the only independent predictor (P=0.0004). The requirement for extensive pulmonary resection (sleeve lobectomy, bilobectomy or pneumonectomy) was significantly more frequent in the patient group with positive compared with the group with negative PET/CT findings (76 vs. 9%, respectively, P=0.01). Therefore, the PET/CT findings in the hilar lymph nodes were useful for the prediction of extracapsular invasion and, consequently, for the estimation of possible extensive pulmonary resection.

Impacts of biological and procedural factors on semiquantification uptake value of liver in fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography imaging.

PubMed

Mahmud, Mohd Hafizi; Nordin, Abdul Jalil; Ahmad Saad, Fathinul Fikri; Azman, Ahmad Zaid Fattah

2015-10-01

Increased metabolic activity of fluorodeoxyglucose (FDG) in tissue is not only resulting of pathological uptake, but due to physiological uptake as well. This study aimed to determine the impacts of biological and procedural factors on FDG uptake of liver in whole body positron emission tomography/computed tomography (PET/CT) imaging. Whole body fluorine-18 ((18)F) FDG PET/CT scans of 51 oncology patients have been reviewed. Maximum standardized uptake value (SUVmax) of lesion-free liver was quantified in each patient. Pearson correlation was performed to determine the association between the factors of age, body mass index (BMI), blood glucose level, FDG dose and incubation period and liver SUVmax. Multivariate regression analysis was established to determine the significant factors that best predicted the liver SUVmax. Then the subjects were dichotomised into four BMI groups. Analysis of variance (ANOVA) was established for mean difference of SUVmax of liver between those BMI groups. BMI and incubation period were significantly associated with liver SUVmax. These factors were accounted for 29.6% of the liver SUVmax variance. Statistically significant differences were observed in the mean SUVmax of liver among those BMI groups (P<0.05). BMI and incubation period are significant factors affecting physiological FDG uptake of liver. It would be recommended to employ different cut-off value for physiological liver SUVmax as a reference standard for different BMI of patients in PET/CT interpretation and use a standard protocol for incubation period of patient to reduce variation in physiological FDG uptake of liver in PET/CT study.

Detection of incidental colorectal pathology on positron emission tomography/computed tomography.

PubMed

Mui, Milton; Akhurst, Timothy; Warrier, Satish K; Lynch, A Craig; Heriot, Alexander G

2018-03-01

Positron emission tomography/computed tomography (PET/CT) is an important modality in cancer imaging. With its increasing availability and use, it is not uncommon to detect incidental focal colorectal 18 F-FDG uptake which poses a diagnostic challenge, as they may be associated with malignant or pre-malignant colorectal lesions. The aim of our study is to determine the proportion of these findings which represents true pathology. Patients with incidental focal colorectal 18 F-FDG uptake on PET/CT who subsequently underwent colonoscopy between January 2002 to September 2013 were identified from a prospective database in a tertiary referral centre. PET/CT results were correlated with colonoscopy and pathology results in these patients. Positive predictive values (PPVs) and 95% confidence intervals (CIs) of PET/CT in the detection of incidental colorectal pathology were calculated. A total of 148 patients (92 men and 56 women), with a mean age 73 years (range of 36 to 93 years) were included in the study. A total of 170 foci of colorectal 18 F-FDG uptake were detected on PET/CT. Of these, 101 foci corresponded to a malignant or pre-malignant lesion (PPV 59%; 95% CI: 52-67%). On a per-patient analysis, 93 patients had at least one focus of colorectal 18 F-FDG uptake which corresponded to a pre-malignant or malignant lesion (PPV 63%; 95% CI: 54-71%). Focal colorectal 18 F-FDG uptake on PET/CT is associated with a significant proportion of malignant or pre-malignant lesions. Further evaluation with colonoscopy is recommended. © 2016 Royal Australasian College of Surgeons.

Futility of fluorodeoxyglucose F 18 positron emission tomography in initial evaluation of patients with T2 to T4 melanoma.

PubMed

Clark, Paige B; Soo, Victoria; Kraas, Jonathan; Shen, Perry; Levine, Edward A

2006-03-01

Evaluation of newly diagnosed patients with melanoma for metastasis is requisite to treatment planning. The reported diagnostic yield of whole-body conventional radiological imaging in initial staging of patients with melanoma is low. However, the diagnostic yield of positron emission tomography (PET) for distant metastases is unclear. There is no utility of PET as part of a routine metastatic survey in patients with T2 to T4 melanoma. Retrospective review of a cohort study between December 1998 and July 2004. University hospital tertiary care center. There were 64 patients with T2 to T4 melanomas who underwent PET for detection of occult metastases at our institution. All patients underwent surgical excision of the primary lesion and sentinel lymph node dissection. Data included were pathologic findings of the primary lesion and sentinel lymph nodes, laboratory data, and radiological reports. None of the patients had clinically suspected regional or distant metastases prior to PET. The diagnostic yield of PET was evaluated through retrospective analysis. Positive scans were then correlated for accuracy with follow-up imaging, biopsy, and clinical information when available. Positron emission tomography did not reveal occult distant metastases in any of the patients. Positron emission tomographic scans showed no abnormalities in 94% of these patients. In 2 patients (3%), false-positive findings were reported on PET (muscular activity and intranodal melanocytic nevocellular inclusion). Further, PET was not useful in predicting regional lymph node metastases. Nineteen of 64 patients had positive sentinel lymph nodes, and only 2 (11%) were identified on PET. Overall, PET did not change clinical management in any of the patients. This study suggests no utility for PET in the detection of occult metastases in patients at initial diagnosis of melanoma. Omission of PET imaging from preoperative evaluations for patients with melanoma is recommended.

Distribution of adoptively transferred porcine T-lymphoblasts tracked by (18)F-2-fluoro-2-deoxy-D-glucose and position emission tomography.

PubMed

Eriksson, Olof; Sadeghi, Arian; Carlsson, Björn; Eich, Torsten; Lundgren, Torbjörn; Nilsson, Bo; Tötterman, Thomas; Korsgren, Olle; Sundin, Anders

2011-08-01

Autologous or allogeneic transfer of tumor-infiltrating T-lymphocytes is a promising treatment for metastatic cancers, but a major concern is the difficulty in evaluating cell trafficking and distribution in adoptive cell therapy. This study presents a method of tracking transfusion of T-lymphoblasts in a porcine model by (18)F-2-fluoro-2-deoxy-d-glucose ([(18)F]FDG) and positron emission tomography. T-lymphoblasts were labeled with the positron-emitting tracer [(18)F]FDG through incubation. The T-lymphoblasts were administered into the bloodstream, and the distribution was followed by positron emission tomography for 120 min. The cells were administered either intravenously into the internal jugular vein (n=5) or intraarterially into the ascending aorta (n=1). Two of the pigs given intravenous administration were pretreated with low-molecular-weight dextran sulphate. The cellular kinetics and distribution were readily quantifiable for up to 120 min. High (78.6% of the administered cells) heterogeneous pulmonary uptake was found after completed intravenous transfusion. The pulmonary uptake was decreased either by preincubating and coadministrating the T-lymphoblasts with low-molecular-weight dextran sulphate or by administrating them intraarterially. The present work shows the feasibility of quantitatively monitoring and evaluating cell trafficking and distribution following administration of [(18)F]FDG-labeled T-lymphoblasts. The protocol can potentially be transferred to the clinical setting with few modifications. Copyright © 2011 Elsevier Inc. All rights reserved.

An incidentally found inflamed uterine myoma causing low abdominal pain, using Tc-99m-tektrotyd single photon emission computed tomography-CT hybrid imaging.

PubMed

Zandieh, Shahin; Schütz, Matthias; Bernt, Reinhard; Zwerina, Jochen; Haller, Joerg

2013-01-01

We report the case of a 50-year-old woman presented with a history of right hemicolectomy due to an ileocecal neuroendocrine tumor and left breast metastasis. Owing to a slightly elevated chromogranin A-level and lower abdominal pain, single photon emission computed tomography-computer tomography (SPECT-CT) was performed. There were no signs of recurrence on the SPECT-CT scan, but the patient was incidentally found to have an inflamed intramural myoma. We believe that the slightly elevated chromogranin A-level was caused by the hypertension that the patient presented. In the clinical context, this is a report of an inflamed uterine myoma seen as a false positive result detected by TC-99m-Tc-EDDA/HYNIC-Tyr3-Octreotide (Tektrotyd) SPECT-CT hybrid imaging.

A computed tomography-based spatial normalization for the analysis of [18F] fluorodeoxyglucose positron emission tomography of the brain.

PubMed

Cho, Hanna; Kim, Jin Su; Choi, Jae Yong; Ryu, Young Hoon; Lyoo, Chul Hyoung

2014-01-01

We developed a new computed tomography (CT)-based spatial normalization method and CT template to demonstrate its usefulness in spatial normalization of positron emission tomography (PET) images with [(18)F] fluorodeoxyglucose (FDG) PET studies in healthy controls. Seventy healthy controls underwent brain CT scan (120 KeV, 180 mAs, and 3 mm of thickness) and [(18)F] FDG PET scans using a PET/CT scanner. T1-weighted magnetic resonance (MR) images were acquired for all subjects. By averaging skull-stripped and spatially-normalized MR and CT images, we created skull-stripped MR and CT templates for spatial normalization. The skull-stripped MR and CT images were spatially normalized to each structural template. PET images were spatially normalized by applying spatial transformation parameters to normalize skull-stripped MR and CT images. A conventional perfusion PET template was used for PET-based spatial normalization. Regional standardized uptake values (SUV) measured by overlaying the template volume of interest (VOI) were compared to those measured with FreeSurfer-generated VOI (FSVOI). All three spatial normalization methods underestimated regional SUV values by 0.3-20% compared to those measured with FSVOI. The CT-based method showed slightly greater underestimation bias. Regional SUV values derived from all three spatial normalization methods were correlated significantly (p < 0.0001) with those measured with FSVOI. CT-based spatial normalization may be an alternative method for structure-based spatial normalization of [(18)F] FDG PET when MR imaging is unavailable. Therefore, it is useful for PET/CT studies with various radiotracers whose uptake is expected to be limited to specific brain regions or highly variable within study population.

PATIENT STUDY OF IN VIVO VERIFICATION OF BEAM DELIVERY AND RANGE, USING POSITRON EMISSION TOMOGRAPHY AND COMPUTED TOMOGRAPHY IMAGING AFTER PROTON THERAPY

PubMed Central

Parodi, Katia; Paganetti, Harald; Shih, Helen A.; Michaud, Susan; Loeffler, Jay S.; Delaney, Thomas F.; Liebsch, Norbert J.; Munzenrider, John E.; Fischman, Alan J.; Knopf, Antje; Bortfeld, Thomas

2007-01-01

Purpose To investigate the feasibility and value of positron emission tomography and computed tomography (PET/CT) for treatment verification after proton radiotherapy. Methods and Materials This study included 9 patients with tumors in the cranial base, spine, orbit, and eye. Total doses of 1.8–3 GyE and 10 GyE (for an ocular melanoma) per fraction were delivered in 1 or 2 fields. Imaging was performed with a commercial PET/CT scanner for 30 min, starting within 20 min after treatment. The same treatment immobilization device was used during imaging for all but 2 patients. Measured PET/CT images were coregistered to the planning CT and compared with the corresponding PET expectation, obtained from CT-based Monte Carlo calculations complemented by functional information. For the ocular case, treatment position was approximately replicated, and spatial correlation was deduced from reference clips visible in both the planning radiographs and imaging CT. Here, the expected PET image was obtained from an analytical model. Results Good spatial correlation and quantitative agreement within 30% were found between the measured and expected activity. For head-and-neck patients, the beam range could be verified with an accuracy of 1–2 mm in well-coregistered bony structures. Low spine and eye sites indicated the need for better fixation and coregistration methods. An analysis of activity decay revealed as tissue-effective half-lives of 800–1,150 s. Conclusions This study demonstrates the feasibility of postradiation PET/CT for in vivo treatment verification. It also indicates some technological and methodological improvements needed for optimal clinical application. PMID:17544003

Accuracy of 18F-FDOPA Positron Emission Tomography and 18F-FET Positron Emission Tomography for Differentiating Radiation Necrosis from Brain Tumor Recurrence.

PubMed

Yu, Jun; Zheng, Jingwei; Xu, Weilin; Weng, Jiaqi; Gao, Liansheng; Tao, Li; Liang, Feng; Zhang, Jianmin

2018-06-01

Distinguishing radiation necrosis from brain tumor recurrence remains challenging. We performed a meta-analysis to assess the diagnostic accuracy of 2 different amino acid tracers used in positron emission tomography/computed tomography scans: 18 F-FDOPA (6-[18F]-fluoro-L-3,4-dihydroxyphenylalanine) and 18 F-FET (O-(2-18F-fluoroethyl)-L-tyrosine). We searched for studies in 3 databases: PubMed, Embase, and Chinese Biomedical databases. The data were extracted from eligible studies and then processed with heterogeneity test, threshold effect test, and calculations of sensitivity, specificity, and area under the summary receiver operating characteristic curve. Meta-regression and subgroup analyses were performed to explore the source of heterogeneity. A total of 48 studies ( 18 F-FDOPA, n = 21; 18 F-FET, n = 27) were included. Quantitative synthesis determined pooled weight values in the 18 F-FDOPA and 18 F-FET groups: sensitivity, 0.85 versus 0.82; specificity, 0.77 versus 0.80; diagnostic odds ratio, 21.7 versus 23.03; area under the curve (AUC) values, 0.8771 versus 0.8976 (P = 0.46). Moreover, the type of tumor was identified as the possible source of the significant heterogeneity (I 2  = 52%; P = 0.003) found in the 18 F-FDOPA group. In meta-regression and subgroup analyses, 18 F-FDOPA showed better diagnostic accuracy in patients with glioma compared with patients with brain metastases (AUC values, 0.9691 vs. 0.837; P < 0.01). 18 F-FDOPA also showed a significant advantage in the diagnosis of glioma recurrence compared with 18 F-FET (AUC values, 0.9691 vs. 0.9124; P = 0.015). Both 18 F-FDOPA and 18 F-FET exhibit moderate overall accuracy in diagnosing brain tumor recurrence from radiation necrosis. However, 18 F-FDOPA is more adept at diagnosing glioma recurrence compared with brain metastases, and it is more effective than 18 F-FET in diagnosing glioma recurrence. Copyright © 2018 Elsevier Inc. All rights reserved.

NUT Midline Carcinoma in Elderly Patients: Usefulness of 18F-FDG PET/CT for Treatment Assessment.

PubMed

Kawase, Takatsugu; Naka, Go; Kubota, Kazuo; Sakashita, Baku; Takeda, Yuichiro

2015-09-01

Nuclear protein in testis (NUT) midline carcinoma is a rare disease that generally arises in adolescents and young adults. However, we encountered a rare NUT midline carcinoma case in an elderly patient. F-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (PET/CT) studies were performed before and during the treatment course. In this case, the initial PET/CT study revealed locoregional hypermetabolism in the mediastinal lesion. After then, the interim PET/CT study indicated a clear diminishing response to the initial treatment, whereas the residual masses were morphologically observable. Nuclear imaging may allow visualization of the therapeutic effect of antineoplastic therapies in both young and elderly patients.

Reliability of eye lens dosimetry in workers of a positron emission tomography radiopharmaceutical production facility.

PubMed

da Silva, Teógenes A; Guimarães, Margarete C; Meireles, Leonardo S; Teles, Luciana L D; Lacerda, Marco Aurélio S

2016-11-01

A new regulatory statement was issued concerning the eye lens radiation protection of persons in planned exposures. A debate was raised on the adequacy of the dosimetric quantity and on its method of measurement. The aim of this work was to establish the individual monitoring procedure with the EYE-D™ holder and a MCP-N LiF:Mg,Cu,P thermoluminescent chip detector for measuring the personal dose equivalent H p (3) in workers of a Positron Emission Tomography Radiopharmaceutical Production Facility. Copyright © 2016 Elsevier Ltd. All rights reserved.

Costal chondrosarcoma requiring differential diagnosis from metastatic tumor.

PubMed

Matsuoka, Katsunari; Ueda, Mitsuhiro; Miyamoto, Yoshihiro

2017-02-01

Although chondrosarcoma is a common malignant bone tumor, cases arising in the rib are relatively rare. We experienced a case of chondrosarcoma arising in the right 10th rib during follow-up after lung cancer surgery. Although the finding of an osteolytic mass suggested a metastatic bone tumor, 18F-fluorodeoxyglucose positron-emission tomography demonstrated low fluorodeoxyglucose uptake, and a primary bone tumor was suspected. The bone tumor was resected and diagnosed as chondrosarcoma. Four years after resection, there has been no recurrence or metastasis. Positron-emission tomography was useful for differential diagnosis between a chondrosarcoma and a metastatic bone tumor.

[Use of positron-emission tomography with F18-fluorodeoxyglucose for the assessment of lung lesions suspicious of malignancy].

PubMed

Jofré, M Josefina; Massardo, Teresa; González, Patricio; Canessa, José; Sierralta, Paulina; Humeres, Pamela; Galaz, Rodrigo; Valdebenito, Robert

2005-05-01

Positron-emission tomography (PET) with F18-fluorodeoxyglucose (FDG) is very helpful in the evaluation and management of lung lesions. It is specially useful for the characterization of solitary nodules, for the staging, evaluation of recurrence and therapeutic response in non-small cell lung cancer, for the evaluation of small cell lung cancer and for the assessment of pulmonary metastases. This article is a literature review on PET with FDG in lung cancer. A preliminary analysis of PET results at the Military Hospital in Santiago, Chile, is also presented.

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.

Monitoring of the biological response to murine hindlimb ischemia with 64Cu-labeled vascular endothelial growth factor-121 positron emission tomography.

PubMed

Willmann, Jürgen K; Chen, Kai; Wang, Hui; Paulmurugan, Ramasamy; Rollins, Mark; Cai, Weibo; Wang, David S; Chen, Ian Y; Gheysens, Olivier; Rodriguez-Porcel, Martin; Chen, Xiaoyuan; Gambhir, Sanjiv S

2008-02-19

Vascular endothelial growth factor-121 (VEGF121), an angiogenic protein secreted in response to hypoxic stress, binds to VEGF receptors (VEGFRs) overexpressed on vessels of ischemic tissue. The purpose of this study was to evaluate 64Cu-VEGF121 positron emission tomography for noninvasive spatial, temporal, and quantitative monitoring of VEGFR2 expression in a murine model of hindlimb ischemia with and without treadmill exercise training. 64Cu-labeled VEGF121 and a VEGF mutant were tested for VEGFR2 binding specificity in cell culture. Mice (n=58) underwent unilateral ligation of the femoral artery, and postoperative tissue ischemia was assessed with laser Doppler imaging. Longitudinal VEGFR2 expression in exercised and nonexercised mice was quantified with 64Cu-VEGF121 positron emission tomography at postoperative day 8, 15, 22, and 29 and correlated with postmortem gamma-counting. Hindlimbs were excised for immunohistochemistry, Western blotting, and microvessel density measurements. Compared with the VEGF mutant, VEGF121 showed specific binding to VEGFR2. Perfusion in ischemic hindlimbs fell to 9% of contralateral hindlimb on postoperative day 1 and recovered to 82% on day 29. 64Cu-VEGF121 uptake in ischemic hindlimbs increased significantly (P < 0.001) from a control level of 0.61+/-0.17% ID/g (percentage of injected dose per gram) to 1.62+/-0.35% ID/g at postoperative day 8, gradually decreased over the following 3 weeks (0.59+/-0.14% ID/g at day 29), and correlated with gamma-counting (R2 = 0.99). Compared with nonexercised mice, 64Cu-VEGF121 uptake was increased significantly (P < or = 0.0001) in exercised mice (at day 15, 22, and 29) and correlated with VEGFR2 levels as obtained by Western blotting (R2 = 0.76). Ischemic hindlimb tissue stained positively for VEGFR2. In exercised mice, microvessel density was increased significantly (P<0.001) compared with nonexercised mice. 64Cu-VEGF121 positron emission tomography allows longitudinal spatial and quantitative monitoring of VEGFR2 expression in murine hindlimb ischemia and indirectly visualizes enhanced angiogenesis stimulated by treadmill exercise training.

WHOLE BODY NONRIGID CT-PET REGISTRATION USING WEIGHTED DEMONS.

PubMed

Suh, J W; Kwon, Oh-K; Scheinost, D; Sinusas, A J; Cline, Gary W; Papademetris, X

2011-03-30

We present a new registration method for whole-body rat computed tomography (CT) image and positron emission tomography (PET) images using a weighted demons algorithm. The CT and PET images are acquired in separate scanners at different times and the inherent differences in the imaging protocols produced significant nonrigid changes between the two acquisitions in addition to heterogeneous image characteristics. In this situation, we utilized both the transmission-PET and the emission-PET images in the deformable registration process emphasizing particular regions of the moving transmission-PET image using the emission-PET image. We validated our results with nine rat image sets using M-Hausdorff distance similarity measure. We demonstrate improved performance compared to standard methods such as Demons and normalized mutual information-based non-rigid FFD registration.

Evaluative studies in nuclear medicine research: emission computed tomography assessment. Final report, January 1-December 31, 1981

DOE Office of Scientific and Technical Information (OSTI.GOV)

Potchen, E.J.; Harris, G.I.; Gift, D.A.

The report provides information on an assessment of the potential short and long term benefits of emission computed tomography (ECT) in biomedical research and patient care. Work during the past year has been augmented by the development and use of an opinion survey instrument to reach a wider representation of knowledgeable investigators and users of this technology. This survey instrument is reproduced in an appendix. Information derived from analysis of the opinion survey, and used in conjunction with results of independent staff studies of available sources, provides the basis for the discussions given in following sections of PET applications inmore » the brain, of technical factors, and of economic implications. Projections of capital and operating costs on a per study basis were obtained from a computerized, pro forma accounting model and are compared with the survey cost estimates for both research and clinical modes of application. The results of a cash-flow model analysis of the relationship between projected economic benefit of PET research to disease management and the costs associated with such research are presented and discussed.« less

[(18)F]-fluorodeoxyglucose positron emission tomography of the cat brain: A feasibility study to investigate osteoarthritis-associated pain.

PubMed

Guillot, Martin; Chartrand, Gabriel; Chav, Ramnada; Rousseau, Jacques; Beaudoin, Jean-François; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Lecomte, Roger; de Guise, Jacques A; Troncy, Eric

2015-06-01

The objective of this pilot study was to investigate central nervous system (CNS) changes related to osteoarthritis (OA)-associated chronic pain in cats using [(18)F]-fluorodeoxyglucose ((18)FDG) positron emission tomography (PET) imaging. The brains of five normal, healthy (non-OA) cats and seven cats with pain associated with naturally occurring OA were imaged using (18)FDG-PET during a standardized mild anesthesia protocol. The PET images were co-registered over a magnetic resonance image of a cat brain segmented into several regions of interest. Brain metabolism was assessed in these regions using standardized uptake values. The brain metabolism in the secondary somatosensory cortex, thalamus and periaqueductal gray matter was increased significantly (P ≤ 0.005) in OA cats compared with non-OA cats. This study indicates that (18)FDG-PET brain imaging in cats is feasible to investigate CNS changes related to chronic pain. The results also suggest that OA is associated with sustained nociceptive inputs and increased activity of the descending modulatory pathways. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mu-opiate receptors measured by positron emission tomography are increased in temporal lobe epilepsy.

PubMed

Frost, J J; Mayberg, H S; Fisher, R S; Douglass, K H; Dannals, R F; Links, J M; Wilson, A A; Ravert, H T; Rosenbaum, A E; Snyder, S H

1988-03-01

Neurochemical studies in animal models of epilepsy have demonstrated the importance of multiple neurotransmitters and their receptors in mediating seizures. The role of opiate receptors and endogenous opioid peptides in seizure mechanisms is well developed and is the basis for measuring opiate receptors in patients with epilepsy. Patients with complex partial seizures due to unilateral temporal seizure foci were studied by positron emission tomography using 11C-carfentanil to measure mu-opiate receptors and 18F-fluoro-deoxy-D-glucose to measure glucose utilization. Opiate receptor binding is greater in the temporal neocortex on the side of the electrical focus than on the opposite side. Modeling studies indicate that the increase in binding is due to an increase in affinity or the number of unoccupied receptors. No significant asymmetry of 11C-carfentanil binding was detected in the amygdala or hippocampus. Glucose utilization correlated inversely with 11C-carfentanil binding in the temporal neocortex. Increased opiate receptors in the temporal neocortex may represent a tonic anticonvulsant system that limits the spread of electrical activity from other temporal lobe structures.

Sodium-22-radiolabeled silica nanoparticles as new radiotracer for biomedical applications: in vivo positron emission tomography imaging, biodistribution, and biocompatibility

PubMed Central

Al Faraj, Achraf; Alotaibi, Basem; Shaik, Abjal Pasha; Shamma, Khaled Z; Al Jammaz, Ibrahim; Gerl, Jürgen

2015-01-01

Despite their advantageous chemical properties for nuclear imaging, radioactive sodium-22 (22Na) tracers have been excluded for biomedical applications because of their extremely long lifetime. In the current study, we proposed, for the first time, the use of 22Na radiotracers for pre-clinical applications by efficiently loading with silica nanoparticles (SiNPs) and thus offering a new life for this radiotracer. Crown-ether-conjugated SiNPs (300 nm; −0.18±0.1 mV) were successfully loaded with 22Na with a loading efficacy of 98.1%±1.4%. Noninvasive positron emission tomography imaging revealed a transient accumulation of 22Na-loaded SiNPs in the liver and to a lower extent in the spleen, kidneys, and lung. However, the signal gradually decreased in a time-dependent manner to become not detectable starting from 2 weeks postinjection. These observations were confirmed ex vivo by quantifying 22Na radioactivity using γ-counter and silicon content using inductively coupled plasma-mass spectrometry in the blood and the different organs of interest. Quantification of Si content in the urine and feces revealed that SiNPs accumulated in the organs were cleared from the body within a period of 2 weeks and completely in 1 month. Biocompatibility evaluations performed during the 1-month follow-up study to assess the possibility of synthesized nanocarriers to induce oxidative stress or DNA damage confirmed their safety for pre-clinical applications. 22Na-loaded nanocarriers can thus provide an innovative diagnostic agent allowing ultra-sensitive positron emission tomography imaging. On the other hand, with its long lifetime, onsite generators or cyclotrons will not be required as 22Na can be easily stored in the nuclear medicine department and be used on-demand. PMID:26504381

Comparison of O-(2-18F-Fluoroethyl)-L-Tyrosine Positron Emission Tomography and Perfusion-Weighted Magnetic Resonance Imaging in the Diagnosis of Patients with Progressive and Recurrent Glioma: A Hybrid Positron Emission Tomography/Magnetic Resonance Study.

PubMed

Verger, Antoine; Filss, Christian P; Lohmann, Philipp; Stoffels, Gabriele; Sabel, Michael; Wittsack, Hans-J; Kops, Elena Rota; Galldiks, Norbert; Fink, Gereon R; Shah, Nadim J; Langen, Karl-Josef

2018-05-01

To compare the diagnostic performance of O-(2- 18 F-fluoroethyl)-L-tyrosine ( 18 F-FET) positron emission tomography (PET) and perfusion-weighted magnetic resonance imaging (PWI) for the diagnosis of progressive or recurrent glioma. Thirty-two pretreated gliomas (25 progressive or recurrent tumors, 7 treatment-related changes) were investigated with 18 F-FET PET and PWI via a hybrid PET/magnetic resonance scanner. Volumes of interest with a diameter of 16 mm were centered on the maximum of abnormality in the tumor area in PET and PWI maps (relative cerebral blood volume, relative cerebral blood flow, mean transit time) and the contralateral unaffected hemisphere. Mean and maximum tumor-to-brain ratios as well as dynamic data for 18 F-FET uptake were calculated. Diagnostic accuracies were evaluated by receiver operating characteristic analyses, calculating the area under the curve. 18 F-FET PET showed a significant greater sensitivity to detect abnormalities in pretreated gliomas than PWI (76% vs. 52%, P = 0.03). The maximum tumor-to-brain ratio of 18 F-FET PET was the only parameter that discriminated treatment-related changes from progressive or recurrent gliomas (area under the curve, 0.78; P = 0.03, best cut-off 2.61; sensitivity 80%, specificity 86%, accuracy 81%). Among patients with signal abnormality in both modalities, 75% revealed spatially incongruent local hot spots. This pilot study suggests that 18 F-FET PET is superior to PWI to diagnose progressive or recurrent glioma. Copyright © 2018 Elsevier Inc. All rights reserved.

Variable uptake feature of focal nodular hyperplasia in Tc-99m phytate hepatic scintigraphy/single-photon emission computed tomography-A parametric analysis.

PubMed

Hsu, Yu-Ling; Chen, Yu-Wen; Lin, Chia-Yang; Lai, Yun-Chang; Chen, Shinn-Cherng; Lin, Zu-Yau

2015-12-01

Tc-99m phytate hepatic scintigraphy remains the standard method for evaluating the functional features of Kupffer cells. In this study, we demonstrate the variable uptake feature of focal nodular hyperplasia (FNH) in Tc-99m phytate scintigraphy. We reviewed all patients who underwent Tc-99m phytate hepatic scintigraphy between 2008 and 2012 in Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. Cases with FNH were diagnosed on the basis of pathology or at least one or more prior imaging with a periodic clinical follow-up. All patients received a standard protocol of dynamic flow study and planar and Tc-99m phytate single-photon emission computed tomography (E. CAM; Siemens). The correlation of variable nodular radioactivity with parameters such as tumor size and localization was analyzed. In total, 15 lesions of 14 patients in the clinic were diagnosed as FNH. The tumor size was approximately 2.9-7.4 cm (mean size 4.6 cm). Four lesions were larger than 5 cm. The major anatomic distribution was in the right hepatic lobe (10 lesions), particularly in the superior segments (7 lesions). Tc-99m phytate single-photon emission computed tomography imaging for determining the functional features of Kupffer cells included cool/cold (8 lesions), isoradioactive/warm (6 lesions), and hot (1 lesion) patterns of uptake. We did not observe any statistically significant correlation between variable nodular radioactivity and tumor size (p=0.68) or localization (p=0.04). Herein, we demonstrate the variable uptake feature of FNH in Tc-99m phytate scintigraphy. In small FNH tumors (< 5 cm), increased or equal uptake still provided specificity for the differential diagnosis of hepatic solid tumors. Copyright © 2015. Published by Elsevier Taiwan.

Influence of 24-Nor-Ursodeoxycholic Acid on Hepatic Disposition of [(18)F]Ciprofloxacin, a Positron Emission Tomography Study in Mice.

PubMed

Wanek, Thomas; Halilbasic, Emina; Visentin, Michele; Mairinger, Severin; Römermann, Kerstin; Stieger, Bruno; Kuntner, Claudia; Müller, Markus; Langer, Oliver; Trauner, Michael

2016-01-01

24-nor-ursodeoxycholic acid (norUDCA) is a novel therapeutic approach to cholestatic liver diseases. In mouse models of cholestasis, norUDCA induces basolateral multidrug resistance-associated proteins 4 (Mrp4) and 3 in hepatocytes, which provide alternative escape routes for bile acids accumulating during cholestasis but could also result in altered hepatic disposition of concomitantly administered substrate drugs. We used positron emission tomography imaging to study the influence of norUDCA on hepatic disposition of the model Mrp4 substrate [(18)F]ciprofloxacin in wild-type and Mdr2((-/-)) mice, a model of cholestasis. Animals underwent [(18)F]ciprofloxacin positron emission tomography at baseline and after norUDCA treatment. After norUDCA treatment, liver-to-blood area under the curve ratio of [(18)F]ciprofloxacin was significantly decreased compared to baseline, both in wild-type (-34.0 ± 2.1%) and Mdr2((-/-)) mice (-20.5 ± 6.0%). [(18)F]Ciprofloxacin uptake clearance from blood into liver was reduced by -17.1 ± 9.0% in wild-type and by -20.1 ± 7.3% in Mdr2((-/-)) mice. Real-time PCR analysis showed significant increases in hepatic Mrp4 and multidrug resistance-associated protein 3 mRNA after norUDCA. Transport experiments in organic anion transporting polypeptide (OATP)1B1-, OATP1B3-, and OATP2B1-transfected cells revealed weak transport of [(14)C]ciprofloxacin by OATP1B3 and OATP2B1 and no inhibition by norUDCA. In conclusion, our data suggest that changes in hepatic [(18)F]ciprofloxacin disposition in mice after norUDCA treatment were caused by induction of basolateral Mrp4 in hepatocytes. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Characterization of novel molecular photoacoustic contrast agents for in vivo photoacoustic tomography

NASA Astrophysics Data System (ADS)

Laoui, Samir

Photoacoustic tomography is a hybrid imaging modality that takes advantage of the high contrast of pure optical imaging and the high intrinsic resolution of ultrasound without the necessity of ionizing radiation. Photoacoustic imaging (PM) is neither purely optical nor purely acoustical in nature, but a combination of the two. It is fundamentally based on light excitation and ultrasonic detection. Photoacoustic imaging has been successful without the introduction of exogenous contrast agents; however, to image deeper regions of biological tissue, a contrast agent is necessary. Several types of photoacoustic contrast agents have been made available for diagnostic purposes; however, the majority of literature has focused on gold nanoparticle systems for which the surface-plasmon resonance effect is important. The only option currently available for molecular PM contrast agents is to choose an existing near infrared absorbing fluorescent probes with the hope that they may generate a substantial photoacoustic (PA) response. However, these dyes have been designed with an optimized fluorescence emission response and are not anticipated to generate an adequate photoacoustic response. This dissertation addresses this lack of precedence in the literature for understanding the mechanism of a photoacoustic signal generation from strongly absorbing dye molecules including BODIPY, cyanine and curcumin systems. This work represents preliminary efforts in bringing novel molecular photoacoustic contrast agents (MPACs) into the photoacoustic imaging arena. To this end, photoacoustic and optical Z-scan experiments, and quenching studies were employed to demonstrate correlation of photoacoustic emission enhancement with excited state absorption mechanisms. To investigate further the photoacoustic emission in a practical imaging setting, MPACs were imaged using a recently developed photoacoustic imaging tomography system which was constructed exclusively for the purpose of this study.

Functional Neuroimaging Studies of Written Sentence Comprehension

ERIC Educational Resources Information Center

Caplan, David

2004-01-01

Sentences convey relationships between the meanings of words, such as who is accomplishing an action or receiving it. Functional neuroimaging based on positron-emission tomography and functional magnetic resonance imaging has been used to identify areas of the brain involved in structuring sentences and determining aspects of meaning associated…

Looking at the Brains behind Figurative Language--A Quantitative Meta-Analysis of Neuroimaging Studies on Metaphor, Idiom, and Irony Processing

ERIC Educational Resources Information Center

Bohrn, Isabel C.; Altmann, Ulrike; Jacobs, Arthur M.

2012-01-01

A quantitative, coordinate-based meta-analysis combined data from 354 participants across 22 fMRI studies and one positron emission tomography (PET) study to identify the differences in neural correlates of figurative and literal language processing, and to investigate the role of the right hemisphere (RH) in figurative language processing.…

The analysis of a rocket tomography measurement of the N2+3914A emission and N2 ionization rates in an auroral arc

NASA Technical Reports Server (NTRS)

Mcdade, Ian C.

1991-01-01

Techniques were developed for recovering two-dimensional distributions of auroral volume emission rates from rocket photometer measurements made in a tomographic spin scan mode. These tomographic inversion procedures are based upon an algebraic reconstruction technique (ART) and utilize two different iterative relaxation techniques for solving the problems associated with noise in the observational data. One of the inversion algorithms is based upon a least squares method and the other on a maximum probability approach. The performance of the inversion algorithms, and the limitations of the rocket tomography technique, were critically assessed using various factors such as (1) statistical and non-statistical noise in the observational data, (2) rocket penetration of the auroral form, (3) background sources of emission, (4) smearing due to the photometer field of view, and (5) temporal variations in the auroral form. These tests show that the inversion procedures may be successfully applied to rocket observations made in medium intensity aurora with standard rocket photometer instruments. The inversion procedures have been used to recover two-dimensional distributions of auroral emission rates and ionization rates from an existing set of N2+3914A rocket photometer measurements which were made in a tomographic spin scan mode during the ARIES auroral campaign. The two-dimensional distributions of the 3914A volume emission rates recoverd from the inversion of the rocket data compare very well with the distributions that were inferred from ground-based measurements using triangulation-tomography techniques and the N2 ionization rates derived from the rocket tomography results are in very good agreement with the in situ particle measurements that were made during the flight. Three pre-prints describing the tomographic inversion techniques and the tomographic analysis of the ARIES rocket data are included as appendices.

Use of PET/CT scanning in cancer patients: technical and practical considerations

PubMed Central

2005-01-01

This overview of the oncologic applications of positron emission tomography (PET) focuses on the technical aspects and clinical applications of a newer technique: the combination of a PET scanner and a computed tomography (CT) scanner in a single (PET/CT) device. Examples illustrate how PET/CT contributes to patient care and improves upon the previous state-of-the-art method of comparing a PET scan with a separate CT scan. Finally, the author presents some of the results from studies of PET/CT imaging that are beginning to appear in the literature. PMID:16252023

Learning Nuclear Chemistry through Practice: A High School Student Project Using PET in a Clinical Setting

ERIC Educational Resources Information Center

Liguori, Lucia; Adamsen, Tom Christian Holm

2013-01-01

Practical experience is vital for promoting interest in science. Several aspects of chemistry are rarely taught in the secondary school curriculum, especially nuclear and radiochemistry. Therefore, we introduced radiochemistry to secondary school students through positron emission tomography (PET) associated with computer tomography (CT). PET-CT…

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 Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Fast simulation of Proton Induced X-Ray Emission Tomography using CUDA

NASA Astrophysics Data System (ADS)

Beasley, D. G.; Marques, A. C.; Alves, L. C.; da Silva, R. C.

2013-07-01

A new 3D Proton Induced X-Ray Emission Tomography (PIXE-T) and Scanning Transmission Ion Microscopy Tomography (STIM-T) simulation software has been developed in Java and uses NVIDIA™ Common Unified Device Architecture (CUDA) to calculate the X-ray attenuation for large detector areas. A challenge with PIXE-T is to get sufficient counts while retaining a small beam spot size. Therefore a high geometric efficiency is required. However, as the detector solid angle increases the calculations required for accurate reconstruction of the data increase substantially. To overcome this limitation, the CUDA parallel computing platform was used which enables general purpose programming of NVIDIA graphics processing units (GPUs) to perform computations traditionally handled by the central processing unit (CPU). For simulation performance evaluation, the results of a CPU- and a CUDA-based simulation of a phantom are presented. Furthermore, a comparison with the simulation code in the PIXE-Tomography reconstruction software DISRA (A. Sakellariou, D.N. Jamieson, G.J.F. Legge, 2001) is also shown. Compared to a CPU implementation, the CUDA based simulation is approximately 30× faster.

Incidental detection of prostate-specific antigen-negative metastatic prostate cancer initially presented with solitary pulmonary nodule on fluorodeoxyglucose positron emission tomography/computed tomography

PubMed Central

Erdogan, Ezgi Basak; Buyukpinarbasili, Nur; Ziyade, Sedat; Akman, Tolga; Turk, Haci Mehmet; Aydin, Mehmet

2015-01-01

A 71-year-old male patient with solitary pulmonary nodule underwent fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) showing slightly increased FDG uptake in this nodule. In addition, PET/CT detected hypermetabolic sclerotic bone lesions in the right second rib and 7th thoracic vertebrae, which were interpreted as possible metastases, and mildly increased FDG uptake in the prostate gland highly suspicious of malignancy. The patient's prostate-specific antigen (PSA) level was within normal range (3.8 ng/dL). The histopathological examination of the lung nodule and right second rib lesion proved metastases from prostate cancer, then the prostate biopsy-confirmed prostate adenocarcinoma. The unique feature of this case is to emphasize the importance of performing PET/CT for solitary pulmonary nodule in detecting PSA-negative metastatic prostate cancer. This case indicated that it should be kept in mind that, even if the PSA is negative, a lung metastasis of prostate cancer may be an underlying cause in patients evaluated for solitary pulmonary nodule by FDG PET/CT. PMID:26170575

Lymphadenopathy resulting from acute toxoplasmosis mimicking relapse of non-Hodgkin's lymphoma on fluorodeoxyglucose positron emission tomography/computed tomography.

PubMed

Joshi, Prathamesh; Lele, Vikram; Mahajan, Pravin

2012-01-01

We report a case documenting fluorodeoxyglucose (FDG) accumulation in cervical, supraclavicular and axillary lymph nodes resulting from acute toxoplasmosis. A 50-year-old Indian female with history of non-Hodgkin's lymphoma (NHL) of left breast, postchemotherapy status, was found to have hypermetabolic right cervical, supraclavicular and axillary lymph nodes on a surveillance FDG positron emission tomography/computed tomography (PET/CT) scan. Her previous two PET/CT scans were unremarkable with no evidence of metabolically active disease. Therefore, a differential diagnosis of relapse of NHL versus infectious/inflammatory pathology was raised in the report. Biopsy of axillary lymph node demonstrated features characteristic of toxoplasmosis. The serological test results were also compatible with acute toxoplasmosis infection. Infective and inflammatory diseases are known to accumulate FDG, resulting in false positives for malignancy. This case demonstrates lymph nodal toxoplasmosis as a potential cause of false positive FDG PET/CT findings in patients with known malignancy and highlights the importance of histopathological and laboratory correlation for the accurate interpretation of FDG PET/CT scans.

Radionuclide Myocardial Perfusion Imaging for the Evaluation of Patients With Known or Suspected Coronary Artery Disease in the Era of Multimodality Cardiovascular Imaging

PubMed Central

Taqueti, Viviany R.; Di Carli, Marcelo F.

2018-01-01

Over the last several decades, radionuclide myocardial perfusion imaging (MPI) with single photon emission tomography and positron emission tomography has been a mainstay for the evaluation of patients with known or suspected coronary artery disease (CAD). More recently, technical advances in separate and complementary imaging modalities including coronary computed tomography angiography, computed tomography perfusion, cardiac magnetic resonance imaging, and contrast stress echocardiography have expanded the toolbox of diagnostic testing for cardiac patients. While the growth of available technologies has heralded an exciting era of multimodality cardiovascular imaging, coordinated and dispassionate utilization of these techniques is needed to implement the right test for the right patient at the right time, a promise of “precision medicine.” In this article, we review the maturing role of MPI in the current era of multimodality cardiovascular imaging, particularly in the context of recent advances in myocardial blood flow quantitation, and as applied to the evaluation of patients with known or suspected CAD. PMID:25770849

Radiolabeling, whole-body single photon emission computed tomography/computed tomography imaging, and pharmacokinetics of carbon nanohorns in mice

PubMed Central

Zhang, Minfang; Jasim, Dhifaf A; Ménard-Moyon, Cécilia; Nunes, Antonio; Iijima, Sumio; Bianco, Alberto; Yudasaka, Masako; Kostarelos, Kostas

2016-01-01

In this work, we report that the biodistribution and excretion of carbon nanohorns (CNHs) in mice are dependent on their size and functionalization. Small-sized CNHs (30–50 nm; S-CNHs) and large-sized CNHs (80–100 nm; L-CNHs) were chemically functionalized and radiolabeled with [111In]-diethylenetriaminepentaacetic acid and intravenously injected into mice. Their tissue distribution profiles at different time points were determined by single photon emission computed tomography/computed tomography. The results showed that the S-CNHs circulated longer in blood, while the L-CNHs accumulated faster in major organs like the liver and spleen. Small amounts of S-CNHs- and L-CNHs were excreted in urine within the first few hours postinjection, followed by excretion of smaller quantities within the next 48 hours in both urine and feces. The kinetics of excretion for S-CNHs were more rapid than for L-CNHs. Both S-CNH and L-CNH material accumulated mainly in the liver and spleen; however, S-CNH accumulation in the spleen was more prominent than in the liver. PMID:27524892

Charged-particle emission tomography

PubMed Central

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

2018-01-01

Purpose 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. Methods 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. Results 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. Conclusions 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. PMID:28370094

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, Inc. on behalf of American Association of Physicists in Medicine.

Safety and biodistribution of 111In-amatuximab in patients with mesothelin expressing cancers using Single Photon Emission Computed Tomography-Computed Tomography (SPECT-CT) imaging

PubMed Central

Adler, Stephen; Mena, Esther; Kurdziel, Karen; Maltzman, Julia; Wallin, Bruce; Hoffman, Kimberly; Pastan, Ira; Paik, Chang Hum; Choyke, Peter; Hassan, Raffit

2015-01-01

Amatuximab is a chimeric high-affinity monoclonal IgG1/k antibody targeting mesothelin that is being developed for treatment of mesothelin-expressing cancers. Considering the ongoing clinical development of amatuximab in these cancers, our objective was to characterize the biodistribution, and dosimetry of 111Indium (111In) radiolabelled amatuximab in mesothelin-expressing cancers. Between October 2011 and February 2013, six patients including four with malignant mesothelioma and two with pancreatic adenocarcinoma underwent Single Photon Emission Computed Tomography-Computed Tomography (SPECT/CT) imaging following administration of 111In amatuximab. SPECT/CT images were obtained at 2–4 hours, 24–48 hours and 96–168 hours after radiotracer injection. In all patients, tumor to background ratios (TBR) consistently met or exceeded an uptake of 1.2 (range 1.2–62.0) which is considered the minimum TBR that can be visualized. TBRs were higher in tumors of patients with mesothelioma than pancreatic adenocarcinoma. 111In-amatuximab uptake was noted in both primary tumors and metastatic sites. The radiotracer dose was generally well-tolerated and demonstrated physiologic uptake in the heart, liver, kidneys and spleen. This is the first study to show tumor localization of an anti-mesothelin antibody in humans. Our results show that 111In-amatuximab was well tolerated with a favorable dosimetry profile. It localizes to mesothelin expressing cancers with a higher uptake in mesothelioma than pancreatic cancer. PMID:25756664

PET scanning in head and neck oncology: a review.

PubMed

McGuirt, W F; Greven, K; Williams, D; Keyes, J W; Watson, N; Cappellari, J O; Geisinger, K R

1998-05-01

The objective of this study was to review and describe the usage of fluorine-labeled deoxyglucose (FDG) and positron emission tomography (PET) in the diagnosis and management of head and neck cancer. Several prospective series,-including 159 newly diagnosed and previously untreated and 23 previously irradiated head and neck squamous cell carcinoma patients initially seen at the Wake Forest University Medical Center and evaluated by clinical examination, conventional computed tomography/ magnetic resonance imaging (CT/MRI) scans, PET scans, and histopathologic studies,-were reviewed and the findings summarized for comparison of the correct differentiation of primary and metastatic cancers and for postirradiation tumor clearance in a subsegment of those cases. Positron emission tomography scanning using a fluorine-labeled deoxyglucose (FDG) radiotracer proved as reliable as conventional scanning for primary and metastatic tumor identification. Compared with clinical examination, PET was better for identification of nodal metastatic tumors but poorer for small primary tumors. For previously irradiated patients treated at least 4 months before the test, PET scanning was clearly superior to clinical examination and conventional imaging in differentiating tumor recurrence from soft-tissue irradiation effects. Fluorine-labeled deoxyglucose-PET scanning is comparable to conventional imaging of head and neck cancers in detecting primary and metastatic carcinoma. Lack of anatomic detail remains its major drawback. Currently, its greatest role is in the evaluation of the postradiotherapy patient.

Diagnosis and evaluation of gastric cancer by positron emission tomography

PubMed Central

Wu, Chen-Xi; Zhu, Zhao-Hui

2014-01-01

Gastric cancer is the second leading cause of cancer mortality worldwide. The diagnosis of gastric cancer has been significantly improved with the broad availability of gastrointestinal endoscopy. Effective technologies for accurate staging and quantitative evaluation are still in demand to merit reasonable treatment and better prognosis for the patients presented with advanced disease. Preoperative staging using conventional imaging tools, such as computed tomography (CT) and endoscopic ultrasonography, is inadequate. Positron emission tomography (PET), using 18F-fluorodeoxyglucose (FDG) as a tracer and integrating CT for anatomic localization, holds a promise to detect unsuspected metastasis and has been extensively used in a variety of malignancies. However, the value of FDG PET/CT in diagnosis and evaluation of gastric cancer is still controversial. This article reviews the current literature in diagnosis, staging, response evaluation, and relapse monitoring of gastric cancer, and discusses the current understanding, improvement, and future prospects in this area. PMID:24782610

Recurrent malignant pheochromocytoma with unusual omental metastasis: 68Ga-DOTANOC PET/CT and 131I-MIBG SPECT/CT scintigraphy findings

PubMed Central

Arora, Saurabh; Agarwal, Krishan Kant; Karunanithi, Sellam; Tripathi, Madhavi; Kumar, Rakesh

2014-01-01

Pheochromocytomas are rare catecholamine-secreting tumors derived from the sympathetic nervous system. The most common sites of metastasis for pheochromocytoma or extra-adrenal paraganglioma are lymph nodes, bones, lungs, and liver. Patients with known or suspected malignancy should undergo staging with computed tomography (CT) or magnetic resonance imaging as well as functional imaging (e.g. with 123I/131I-MIBG (131I-metaiodobenzylguanidine) and 68Ga-DOTANOC (68Ga-labeled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-NaI3-octreotide) positron emission tomography (PET)/CT) to determine the extent and location of disease. We present a case of recurrent malignant pheochromocytoma with unusual site of metastasis in omentum, which was positive on 68Ga-DOTANOC PET/CT and 131I-MIBG single-photon emission computed tomography (SPECT/)/CT scintigraphy. PMID:25400380

Recurrent malignant pheochromocytoma with unusual omental metastasis: (68)Ga-DOTANOC PET/CT and (131)I-MIBG SPECT/CT scintigraphy findings.

PubMed

Arora, Saurabh; Agarwal, Krishan Kant; Karunanithi, Sellam; Tripathi, Madhavi; Kumar, Rakesh

2014-10-01

Pheochromocytomas are rare catecholamine-secreting tumors derived from the sympathetic nervous system. The most common sites of metastasis for pheochromocytoma or extra-adrenal paraganglioma are lymph nodes, bones, lungs, and liver. Patients with known or suspected malignancy should undergo staging with computed tomography (CT) or magnetic resonance imaging as well as functional imaging (e.g. with (123)I/(131)I-MIBG ((131)I-metaiodobenzylguanidine) and (68)Ga-DOTANOC ((68)Ga-labeled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-NaI3-octreotide) positron emission tomography (PET)/CT) to determine the extent and location of disease. We present a case of recurrent malignant pheochromocytoma with unusual site of metastasis in omentum, which was positive on (68)Ga-DOTANOC PET/CT and (131)I-MIBG single-photon emission computed tomography (SPECT/)/CT scintigraphy.

Early prosthetic aortic valve infection identified with the use of positron emission tomography in a patient with lead endocarditis.

PubMed

Amraoui, Sana; Tlili, Ghoufrane; Sohal, Manav; Bordenave, Laurence; Bordachar, Pierre

2016-12-01

18-Fluorodeoxyglucose positron emission tomography/computerized tomography (FDG PET/CT) scanning has recently been proposed as a diagnostic tool for lead endocarditis (LE). FDG PET/CT might be also useful to localize associated septic emboli in patients with LE. We report an interesting case of a LE patient with a prosthetic aortic valve in whom a trans-esophageal echocardiogram did not show associated aortic endocarditis. FDG PET/CT revealed prosthetic aortic valve infection. A second TEE performed 2 weeks after identified aortic vegetation. A longer duration of antimicrobial therapy with serial follow-up echocardiography was initiated. There was also increased uptake in the sigmoid colon, corresponding to focal polyps resected during a colonoscopy. FDG PET/CT scanning seems to be highly sensitive for prosthetic aortic valve endocarditis diagnosis. This promising diagnostic tool may be beneficial in LE patients, by identifying septic emboli and potential sites of pathogen entry.

Generalized subcutaneous edema as a rare manifestation of dermatomyositis: clinical lesson from a rare feature.

PubMed

Haroon, Muhammad; Eltahir, Ahmed; Harney, Sinead

2011-04-01

Generalized subcutaneous edema is a very rare manifestation of inflammatory myopathies. A 61-year-old woman presented with classic signs and symptoms of dermatomyositis. She was also noted to have generalized edema that was so florid that an alternative diagnosis was considered. Her disease was resistant to corticosteroids, azathioprine, and mycophenolate mofetil. Intravenous administration of immunoglobulins was started because of marked worsening of her disease-muscle weakness, generalized anasarca, and involvement of her bulbar muscles. This led to dramatic resolution of her subcutaneous edema and significant improvement of her skin and muscle disease. As the initial screen for malignancy was negative, a positron emission tomography-computed tomography scan was requested, which interestingly showed a metabolically active cervical tumor. Anasarca is an unusual manifestation of dermatomyositis. In treatment-refractory cases, it seems reasonable to consider positron emission tomography scan in excluding underlying malignant disease.

Myocardial perfusion imaging: Lessons learned and work to be done-update.

PubMed

Iskandrian, Ami E; Dilsizian, Vasken; Garcia, Ernest V; Beanlands, Rob S; Cerqueira, Manuel; Soman, Prem; Berman, Daniel S; Cuocolo, Alberto; Einstein, Andrew J; Morgan, Charity J; Hage, Fadi G; Schelbert, Heinrich R; Bax, Jeroen J; Wu, Joseph C; Shaw, Leslee J; Sadeghi, Mehran M; Tamaki, Nagara; Kaufmann, Philipp A; Gropler, Robert; Dorbala, Sharmila; Van Decker, William

2018-02-01

As the second term of our commitment to Journal begins, we, the editors, would like to reflect on a few topics that have relevance today. These include prognostication and paradigm shifts; Serial testing: How to handle data? Is the change in perfusion predictive of outcome and which one? Ischemia-guided therapy: fractional flow reserve vs perfusion vs myocardial blood flow; positron emission tomography (PET) imaging using Rubidium-82 vs N-13 ammonia vs F-18 Flurpiridaz; How to differentiate microvascular disease from 3-vessel disease by PET? The imaging scene outside the United States, what are the differences and similarities? Radiation exposure; Special issues with the new cameras? Is attenuation correction needed? Are there normal databases and are these specific to each camera system? And finally, hybrid imaging with single-photon emission tomography or PET combined with computed tomography angiography or coronary calcium score. We hope these topics are of interest to our readers.

Molecular Imaging in the College of Optical Sciences – An Overview of Two Decades of Instrumentation Development

PubMed Central

Furenlid, Lars R.; Barrett, Harrison H.; Barber, H. Bradford; Clarkson, Eric W.; Kupinski, Matthew A.; Liu, Zhonglin; Stevenson, Gail D.; Woolfenden, James M.

2015-01-01

During the past two decades, researchers at the University of Arizona’s Center for Gamma-Ray Imaging (CGRI) have explored a variety of approaches to gamma-ray detection, including scintillation cameras, solid-state detectors, and hybrids such as the intensified Quantum Imaging Device (iQID) configuration where a scintillator is followed by optical gain and a fast CCD or CMOS camera. We have combined these detectors with a variety of collimation schemes, including single and multiple pinholes, parallel-hole collimators, synthetic apertures, and anamorphic crossed slits, to build a large number of preclinical molecular-imaging systems that perform Single-Photon Emission Computed Tomography (SPECT), Positron Emission Tomography (PET), and X-Ray Computed Tomography (CT). In this paper, we discuss the themes and methods we have developed over the years to record and fully use the information content carried by every detected gamma-ray photon. PMID:26236069

Positron emission tomography molecular imaging of dopaminergic system in drug addiction.

PubMed

Hou, Haifeng; Tian, Mei; Zhang, Hong

2012-05-01

Dopamine (DA) is involved in drug reinforcement, but its role in drug addiction remains unclear. Positron emission tomography (PET) is the first technology used for the direct measurement of components of the dopaminergic system in the living human brain. In this article, we reviewed the major findings of PET imaging studies on the involvement of DA in drug addiction, especially in heroin addiction. Furthermore, we summarized PET radiotracers that have been used to study the role of DA in drug addiction. To investigate presynaptic function in drug addiction, PET tracers have been developed to measure DA synthesis and transport. For the investigation of postsynaptic function, several radioligands targeting dopamine one (D1) receptor and dopamine two (D2) receptor are extensively used in PET imaging studies. Moreover, we also summarized the PET imaging findings of heroin addiction studies, including heroin-induced DA increases and the reinforcement, role of DA in the long-term effects of heroin abuse, DA and vulnerability to heroin abuse and the treatment implications. PET imaging studies have corroborated the role of DA in drug addiction and increase our understanding the mechanism of drug addiction. Copyright © 2012 Wiley Periodicals, Inc.

Diagnostic performance of fluorodeoxyglucose positron emission tomography/magnetic resonance imaging fusion images of gynecological malignant tumors: comparison with positron emission tomography/computed tomography.

PubMed

Nakajo, Kazuya; Tatsumi, Mitsuaki; Inoue, Atsuo; Isohashi, Kayako; Higuchi, Ichiro; Kato, Hiroki; Imaizumi, Masao; Enomoto, Takayuki; Shimosegawa, Eku; Kimura, Tadashi; Hatazawa, Jun

2010-02-01

We compared the diagnostic accuracy of fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and PET/magnetic resonance imaging (MRI) fusion images for gynecological malignancies. A total of 31 patients with gynecological malignancies were enrolled. FDG-PET images were fused to CT, T1- and T2-weighted images (T1WI, T2WI). PET-MRI fusion was performed semiautomatically. We performed three types of evaluation to demonstrate the usefulness of PET/MRI fusion images in comparison with that of inline PET/CT as follows: depiction of the uterus and the ovarian lesions on CT or MRI mapping images (first evaluation); additional information for lesion localization with PET and mapping images (second evaluation); and the image quality of fusion on interpretation (third evaluation). For the first evaluation, the score for T2WI (4.68 +/- 0.65) was significantly higher than that for CT (3.54 +/- 1.02) or T1WI (3.71 +/- 0.97) (P < 0.01). For the second evaluation, the scores for the localization of FDG accumulation showing that T2WI (2.74 +/- 0.57) provided significantly more additional information for the identification of anatomical sites of FDG accumulation than did CT (2.06 +/- 0.68) or T1WI (2.23 +/- 0.61) (P < 0.01). For the third evaluation, the three-point rating scale for the patient group as a whole demonstrated that PET/T2WI (2.72 +/- 0.54) localized the lesion significantly more convincingly than PET/CT (2.23 +/- 0.50) or PET/T1WI (2.29 +/- 0.53) (P < 0.01). PET/T2WI fusion images are superior for the detection and localization of gynecological malignancies.

Orbital flourine-18-fluorodeoxyglucose positron emission tomography in patients with Graves' disease for evaluation of active inflammation.

PubMed

Uslu-Beşli, Lebriz; Kabasakal, Levent; Sağer, Sait; Cicik, Erdoğan; Asa, Sertaç; Sönmezoğlu, Kerim

2017-11-01

Prediction and early diagnosis of orbitopathy is needed in patients with Graves' disease, especially when radioiodine therapy is planned. Positron emission tomography/computerized tomography (PET/CT) using flourine-18-fluorodeoxyglucose (FDG) is an effective imaging modality in detection of inflammation, however, its ability to detect orbital inflammation has not been well studied. The aim of our study is to determine the ability of FDG PET/CT to detect orbital inflammation related with Graves' disease, identify active orbitopathy, predict the radioiodine-triggered orbitopathy, and find out the effects of radioiodine on orbital inflammation. Total 31 Graves' disease patients and 17 controls were included. All Graves' disease patients underwent cranial FDG PET/CT imaging prior therapy. Radioiodine therapy and post-treatment PET/CT study was applied to 21 patients. PET/CT images of all examinees were evaluated, measuring extraocular muscle maximum standard uptake value (SUVmax) and muscle thickness. FDG uptake was increased in the majority of extraocular muscles in Graves' disease patients in comparison to controls and this increase was found to be irrelevant from muscle thickness. Extraocular muscle SUVmax values did not increase in Graves' orbitopathy patients who received radioiodine under corticosteroid prophylaxis. SUVmax level of all orbital rectus muscles were increased after radioiodine therapy in nonsmokers, whereas no increase was detected in smokers. FDG PET/CT may be helpful in detection of extraocular muscle inflammation and it may show ongoing orbitopathy in early stages of inflammation before anatomical changes occur.

The timing of adoption of positron emission tomography: a real options approach.

PubMed

Pertile, Paolo; Torri, Emanuele; Flor, Luciano; Tardivo, Stefano

2009-09-01

This paper presents the economic evaluation from a hospital's perspective of the investment in positron emission tomography, adopting a real options approach. The installation of this equipment requires a major capital outlay, while uncertainty on several key variables is substantial. The value of several timing strategies, including sequential investment, is determined taking into account that future decisions will be based on the information available at that time. The results show that adopting this approach may have an impact on the timing of investment, because postponing the investment may be optimal even when the Expected Net Present Value of the project is positive.

Multi-Spacecraft 3D differential emission measure tomography of the solar corona: STEREO results.

NASA Astrophysics Data System (ADS)

Vásquez, A. M.; Frazin, R. A.

We have recently developed a novel technique (called DEMT) for the em- pirical determination of the three-dimensional (3D) distribution of the so- lar corona differential emission measure through multi-spacecraft solar ro- tational tomography of extreme-ultaviolet (EUV) image time series (like those provided by EIT/SOHO and EUVI/STEREO). The technique allows, for the first time, to develop global 3D empirical maps of the coronal elec- tron temperature and density, in the height range 1.0 to 1.25 RS . DEMT constitutes a simple and powerful 3D analysis tool that obviates the need for structure specific modeling.

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.

Emission computerized axial tomography from multiple gamma-camera views using frequency filtering.

PubMed

Pelletier, J L; Milan, C; Touzery, C; Coitoux, P; Gailliard, P; Budinger, T F

1980-01-01

Emission computerized axial tomography is achievable in any nuclear medicine department from multiple gamma camera views. Data are collected by rotating the patient in front of the camera. A simple fast algorithm is implemented, known as the convolution technique: first the projection data are Fourier transformed and then an original filter designed for optimizing resolution and noise suppression is applied; finally the inverse transform of the latter operation is back-projected. This program, which can also take into account the attenuation for single photon events, was executed with good results on phantoms and patients. We think that it can be easily implemented for specific diagnostic problems.

An analysis of regional cerebral blood flow in impulsive murderers using single photon emission computed tomography.

PubMed

Amen, Daniel G; Hanks, Chris; Prunella, Jill R; Green, Aisa

2007-01-01

The authors explored differences in regional cerebral blood flow in 11 impulsive murderers and 11 healthy comparison subjects using single photon emission computed tomography. The authors assessed subjects at rest and during a computerized go/no-go concentration task. Using statistical parametric mapping software, the authors performed voxel-by-voxel t tests to assess significant differences, making family-wide error corrections for multiple comparisons. Murderers were found to have significantly lower relative rCBF during concentration, particularly in areas associated with concentration and impulse control. These results indicate that nonemotionally laden stimuli may result in frontotemporal dysregulation in people predisposed to impulsive violence.

Contribution of positron emission tomography in pleural disease.

PubMed

Duysinx, B; Corhay, J-L; Larock, M-P; Withofs, N; Bury, T; Hustinx, R; Louis, R

2010-10-01

Positron emission tomography (PET) now plays a clear role in oncology, especially in chest tumours. We discuss the value of metabolic imaging in characterising pleural pathology in the light of our own experience and review the literature. PET is particularly useful in characterising malignant pleural pathologies and is a factor of prognosis in mesothelioma. Metabolic imaging also provides clinical information for staging lung cancer, in researching the primary tumour in metastatic pleurisy and in monitoring chronic or recurrent pleural pathologies. PET should therefore be considered as a useful tool in the diagnosis of liquid or solid pleural pathologies. Copyright © 2010 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Cardiac Sarcoidosis Concomitant with Large-vessel Aortitis Detected by 18F-fluorodeoxyglucose Positron Emission Tomography.

PubMed

Higuchi, Yoshihiro; Kimoto, Yasutaka; Tanoue, Rika; Tokunou, Tomotake; Tomonari, Kenichiro; Maeda, Toyoki; Horiuchi, Takahiko

2018-06-01

We herein report a case of concurrent cardiac sarcoidosis and large-vessel aortitis detected by 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) and followed up during immunosuppressive therapy. After high-dose prednisolone administration (1 mg/kg), serial FDG-PET showed that almost all of the abnormal FDG uptake in the heart and extracardiac region, including the abdominal to bilateral iliac arteries, had been disappeared. During the tapering of prednisolone, additive methotrexate therapy was needed to treat the recurrence of cardiac sarcoidosis. FDG-PET is a useful tool for detecting cardiac sarcoidosis concomitant with large-vessel aortitis and monitoring the effectiveness of immunosuppressive therapy.

Malignant external otitis: early scintigraphic detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strashun, A.M.; Nejatheim, M.; Goldsmith, S.J.

1984-02-01

Pseudomonas otitis externa in elderly diabetics may extend aggressively to adjacent bone, cranial nerves, meninges, and vessels, leading to a clinical diagnosis of ''malignant'' external otitis. Early diagnosis is necessary for successful treatment. This study compares the findings of initial radiographs, thin-section tomography of temporal bone, CT scans of head and neck, technetium-99m methylene diphosphonate (MDP) and gallium-67 citrate scintigraphy, and single-photon emission computed tomography (SPECT) for detection of temporal bone osteomylitis in ten patients fulfilling the clinical diagnostic criteria of malignant external otitis. Skull radiographs were negative in all of the eight patients studied. Thin-section tomography was positive inmore » one of the seven patients studied using this modality. CT scanning suggested osteomyelitis in three of nine patients. Both Tc-99m and Ga-67 citrate scintigraphy were positive in 10 of 10 patients. These results suggest that technetium and gallium scintigraphy are more sensitive than radiographs and CT scans for early detection of malignant external otitis.« less

Doppler tomography and photometry of the cataclysmic variable 1RXS J064434.5+334451

NASA Astrophysics Data System (ADS)

Hernández Santisteban, J. V.; Echevarría, J.; Michel, R.; Costero, R.

2017-01-01

We have obtained simultaneous photometric and spectroscopic observations of the cataclysmic variable 1RXS J064434.5+334451. We have calibrated the spectra for slit losses using simultaneous photometry, allowing us to construct reliable Doppler images from Hα and He II 4686-Å emission lines. We have improved the ephemeris of the object based on new photometric eclipse timings, obtaining HJD = 245 3403.759 533 + 0.269 374 46E. Some eclipses present a clear internal structure, which we attribute to a central He II emission region surrounding the white dwarf, a finding supported by Doppler tomography. This indicates that the system has a large inclination angle I = 78 ± 2°. We have also analysed the radial velocity curve from the emission lines to measure its semi-amplitude, K1, from Hα and He II 4686 and derive the masses of the components M1 = 0.82 ± 0.06 M⊙, M2 = 0.78 ± 0.04 M⊙ and their separation a = 2.01 ± 0.06 R⊙. The Doppler tomography and other observed features in this nova-like system strongly suggest that this is a SW Sex type system.

18F-positron-emitting/fluorescent labeled erythrocytes allow imaging of internal hemorrhage in a murine intracranial hemorrhage model

PubMed Central

Wang, Ye; An, Fei-Fei; Chan, Mark; Friedman, Beth; Rodriguez, Erik A; Tsien, Roger Y; Aras, Omer

2017-01-01

An agent for visualizing cells by positron emission tomography is described and used to label red blood cells. The labeled red blood cells are injected systemically so that intracranial hemorrhage can be visualized by positron emission tomography (PET). Red blood cells are labeled with 0.3 µg of a positron-emitting, fluorescent multimodal imaging probe, and used to non-invasively image cryolesion induced intracranial hemorrhage in a murine model (BALB/c, 2.36 × 108 cells, 100 µCi, <4 mm hemorrhage). Intracranial hemorrhage is confirmed by histology, fluorescence, bright-field, and PET ex vivo imaging. The low required activity, minimal mass, and high resolution of this technique make this strategy an attractive alternative for imaging intracranial hemorrhage. PET is one solution to a spectrum of issues that complicate single photon emission computed tomography (SPECT). For this reason, this application serves as a PET alternative to [99mTc]-agents, and SPECT technology that is used in 2 million annual medical procedures. PET contrast is also superior to gadolinium and iodide contrast angiography for its lack of clinical contraindications. PMID:28054494

The Quality of Staging Non-Small Cell Lung Cancer in the Netherlands: Data From the Dutch Lung Surgery Audit.

PubMed

Heineman, David Jonathan; Ten Berge, Martijn Geert; Daniels, Johannes Marlene; Versteegh, Michaël Ignatius; Marang-van de Mheen, Perla Jacqueline; Wouters, Michael Wilhelmus; Schreurs, Wilhelmina Hendrika

2016-11-01

Clinical staging of non-small cell lung cancer (NSCLC) determines the initial treatment offered to a patient. The similarity between clinical and pathologic staging in some studies is as low as 50%, and others publish results as high as 91%. The Dutch Lung Surgery Audit is a clinical database that registers the clinical and pathologic TNM of almost all NSCLC patients who undergo operations in the Netherlands. The objective of this study was to determine the accuracy of clinical staging of NSCLC. Prospective data were derived from the Dutch Lung Surgery Audit in 2013 and 2014. Patients were included if they had undergone a surgical resection for stage IA to IIIB NSCLC without neoadjuvant treatment and had a positron emission tomography-computed tomography scan as part of the clinical workup. Clinical (c)TNM and pathologic (p)TNM were compared, and whether discrepancy was based on tumor or nodal staging was determined. From 2,834 patients identified, 2,336 (82.4%) fulfilled the inclusion criteria and had complete data. Of these 2,336, 1,276 (54.6%) were staged accurately, 707 (30.3%) were clinically understaged, and 353 (15.1%) were clinically overstaged. In the understaged group, 346 patients had a higher pN stage (14.8%), of which 148 patients had unforeseen N2 disease (6.3%). In the overstaged group, 133 patients had a cN that was higher than the pN (5.7%). Accuracy of NSCLC staging in the Netherlands is low (54.6%), even in the era of positron emission tomography-computed tomography. Especially accurate nodal staging remains challenging. Future efforts should include the identification of specific pitfalls in NSCLC staging. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

The Added Value of a Single-photon Emission Computed Tomography-Computed Tomography in Sentinel Lymph Node Mapping in Patients with Breast Cancer and Malignant Melanoma.

PubMed

Bennie, George; Vorster, Mariza; Buscombe, John; Sathekge, Mike

2015-01-01

Single-photon emission computed tomography-computed tomography (SPECT-CT) allows for physiological and anatomical co-registration in sentinel lymph node (SLN) mapping and offers additional benefits over conventional planar imaging. However, the clinical relevance when considering added costs and radiation burden of these reported benefits remains somewhat uncertain. This study aimed to evaluate the possible added value of SPECT-CT and intra-operative gamma-probe use over planar imaging alone in the South African setting. 80 patients with breast cancer or malignant melanoma underwent both planar and SPECT-CT imaging for SLN mapping. We assessed and compared the number of nodes detected on each study, false positive and negative findings, changes in surgical approach and or patient management. In all cases where a sentinel node was identified, SPECT-CT was more accurate anatomically. There was a significant change in surgical approach in 30 cases - breast cancer (n = 13; P 0.001) and malignant melanoma (n = 17; P 0.0002). In 4 cases a node not identified on planar imaging was seen on SPECT-CT. In 16 cases additional echelon nodes were identified. False positives were excluded by SPECT-CT in 12 cases. The addition of SPECT-CT and use of intra-operative gamma-probe to planar imaging offers important benefits in patients who present with breast cancer and melanoma. These benefits include increased nodal detection, elimination of false positives and negatives and improved anatomical localization that ultimately aids and expedites surgical management. This has been demonstrated in the context of industrialized country previously and has now also been confirmed in the setting of a emerging-market nation.

Intra-tumour 18F-FDG uptake heterogeneity decreases the reliability on target volume definition with positron emission tomography/computed tomography imaging.

PubMed

Dong, Xinzhe; Wu, Peipei; Sun, Xiaorong; Li, Wenwu; Wan, Honglin; Yu, Jinming; Xing, Ligang

2015-06-01

This study aims to explore whether the intra-tumour (18) F-fluorodeoxyglucose (FDG) uptake heterogeneity affects the reliability of target volume definition with FDG positron emission tomography/computed tomography (PET/CT) imaging for nonsmall cell lung cancer (NSCLC) and squamous cell oesophageal cancer (SCEC). Patients with NSCLC (n = 50) or SCEC (n = 50) who received (18)F-FDG PET/CT scanning before treatments were included in this retrospective study. Intra-tumour FDG uptake heterogeneity was assessed by visual scoring, the coefficient of variation (COV) of the standardised uptake value (SUV) and the image texture feature (entropy). Tumour volumes (gross tumour volume (GTV)) were delineated on the CT images (GTV(CT)), the fused PET/CT images (GTV(PET-CT)) and the PET images, using a threshold at 40% SUV(max) (GTV(PET40%)) or the SUV cut-off value of 2.5 (GTV(PET2.5)). The correlation between the FDG uptake heterogeneity parameters and the differences in tumour volumes among GTV(CT), GTV(PET-CT), GTV(PET40%) and GTV(PET2.5) was analysed. For both NSCLC and SCEC, obvious correlations were found between uptake heterogeneity, SUV or tumour volumes. Three types of heterogeneity parameters were consistent and closely related to each other. Substantial differences between the four methods of GTV definition were found. The differences between the GTV correlated significantly with PET heterogeneity defined with the visual score, the COV or the textural feature-entropy for NSCLC and SCEC. In tumours with a high FDG uptake heterogeneity, a larger GTV delineation difference was found. Advance image segmentation algorithms dealing with tracer uptake heterogeneity should be incorporated into the treatment planning system. © 2015 The Royal Australian and New Zealand College of Radiologists.

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

Metabolic and clinical assessment of efficacy of cryoablation therapy on skeletal masses by 18F-FDG positron emission tomography/computed tomography (PET/CT) and visual analogue scale (VAS): initial experience.

PubMed

Masala, Salvatore; Schillaci, Orazio; Bartolucci, Alberto D; Calabria, Ferdinando; Mammucari, Matteo; Simonetti, Giovanni

2011-02-01

Various therapy modalities have been proposed as standard treatments in management of bone metastases. Radiation therapy remains the standard of care for patients with localized bone pain, but up to 30% of them do not experience notable pain relief. Percutaneous cryoablation is a minimally invasive technique that induces necrosis by alternately freezing and thawing a target tissue. This technique is successfully used to treat a variety of malignant and benign diseases in different sites. (18)F-FDG positron emission tomography/computed tomography ((18)F-FDG PET/CT) is a single technique of imaging that provides in a "single step" both morphological and metabolic features of neoplastic lesions of the bone. The aim of this study was to evaluate the efficacy of the cryosurgical technique on secondary musculoskeletal masses according to semi-quantitative PET analysis and clinical-test evaluation with the visual analogue scale (VAS). We enrolled 20 patients with painful bone lesions (score pain that exceeded 4 on the VAS) that were non-responsive to treatment; one lesion per patient was treated. All patients underwent a PET-CT evaluation before and 8 weeks after cryotherapy; maximum standardized uptake value (SUV(max)) was measured before and after treatment for metabolic assessment of response to therapy. After treatment, 18 patients (90%) showed considerable reduction in SUV(max) value (>50%) suggestive of response to treatment; only 2 patients did not show meaningful reduction in metabolic activity. Our preliminary study demonstrates that quantitative analysis provided by PET correlates with response to cryoablation therapy as assessed by CT data and clinical VAS evaluation.

(18)F-fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma.

PubMed

Li, Xiao-Feng; Fu, Qiang; Dong, You-Wen; Liu, Jian-Jing; Song, Xiu-Yu; Dai, Dong; Zuo, Cong; Xu, Wen-Gui

2016-09-14

To compare (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma. Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent (18)F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions, including FDG avidity, pattern (focal/diffuse), and intensity [maximal standard uptake value: (SUVmax)]. The correlation of SUVmax with gastric clinicopathological variables was investigated by χ(2) test, and receiver-operating characteristic (ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma. Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients (94.23%) with gastric lymphoma and 65 patients (89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type I and type II lesions, whereas gastric carcinoma patients mainly had type III lesions. The SUVmax (13.39 ± 9.24 vs 8.35 ± 5.80, P < 0.001) and SUVmax/THKmax (maximal thickness) (7.96 ± 4.02 vs 4.88 ± 3.32, P < 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone. PET/CT features differ between gastric lymphoma and carcinoma, which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma.

18F-fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma

PubMed Central

Li, Xiao-Feng; Fu, Qiang; Dong, You-Wen; Liu, Jian-Jing; Song, Xiu-Yu; Dai, Dong; Zuo, Cong; Xu, Wen-Gui

2016-01-01

AIM To compare 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma. METHODS Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent 18F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions, including FDG avidity, pattern (focal/diffuse), and intensity [maximal standard uptake value: (SUVmax)]. The correlation of SUVmax with gastric clinicopathological variables was investigated by χ2 test, and receiver-operating characteristic (ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma. RESULTS Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients (94.23%) with gastric lymphoma and 65 patients (89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type I and type II lesions, whereas gastric carcinoma patients mainly had type III lesions. The SUVmax (13.39 ± 9.24 vs 8.35 ± 5.80, P < 0.001) and SUVmax/THKmax (maximal thickness) (7.96 ± 4.02 vs 4.88 ± 3.32, P < 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone. CONCLUSION PET/CT features differ between gastric lymphoma and carcinoma, which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma. PMID:27678362

The use of combined single photon emission computed tomography and X-ray computed tomography to assess the fate of inhaled aerosol.

PubMed

Fleming, John; Conway, Joy; Majoral, Caroline; Tossici-Bolt, Livia; Katz, Ira; Caillibotte, Georges; Perchet, Diane; Pichelin, Marine; Muellinger, Bernhard; Martonen, Ted; Kroneberg, Philipp; Apiou-Sbirlea, Gabriela

2011-02-01

Gamma camera imaging is widely used to assess pulmonary aerosol deposition. Conventional planar imaging provides limited information on its regional distribution. In this study, single photon emission computed tomography (SPECT) was used to describe deposition in three dimensions (3D) and combined with X-ray computed tomography (CT) to relate this to lung anatomy. Its performance was compared to planar imaging. Ten SPECT/CT studies were performed on five healthy subjects following carefully controlled inhalation of radioaerosol from a nebulizer, using a variety of inhalation regimes. The 3D spatial distribution was assessed using a central-to-peripheral ratio (C/P) normalized to lung volume and for the right lung was compared to planar C/P analysis. The deposition by airway generation was calculated for each lung and the conducting airways deposition fraction compared to 24-h clearance. The 3D normalized C/P ratio correlated more closely with 24-h clearance than the 2D ratio for the right lung [coefficient of variation (COV), 9% compared to 15% p < 0.05]. Analysis of regional distribution was possible for both lungs in 3D but not in 2D due to overlap of the stomach on the left lung. The mean conducting airways deposition fraction from SPECT for both lungs was not significantly different from 24-h clearance (COV 18%). Both spatial and generational measures of central deposition were significantly higher for the left than for the right lung. Combined SPECT/CT enabled improved analysis of aerosol deposition from gamma camera imaging compared to planar imaging. 3D radionuclide imaging combined with anatomical information from CT and computer analysis is a useful approach for applications requiring regional information on deposition.

Granulosa cell tumor induced massive recurrence of post hysterectomy leiomyoma

PubMed Central

Chalanki, Mohana Vamsy; Dattatreya, Satya; Padmaja, Parvathaneni; Dayal, Monal; Parakh, Megha; Rao, Vatturi Venkata Satya Prabhakar

2014-01-01

The authors report a very unusual occurrence of a massive recurrence of leiomyoma from post hysterectomy stump diagnosed on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG PET/CT). The case also has an additional complexity of granulosa cell tumor (GCT) of ovary probably contributing to the recurrence and massive size. PMID:25210289

Reduced dopamine receptors and transporters but not synthesis capacity in normal aging adults: a meta-analysis.

PubMed

Karrer, Teresa M; Josef, Anika K; Mata, Rui; Morris, Evan D; Samanez-Larkin, Gregory R

2017-09-01

Many theories of cognitive aging are based on evidence that dopamine (DA) declines with age. Here, we performed a systematic meta-analysis of cross-sectional positron emission tomography and single-photon emission-computed tomography studies on the average effects of age on distinct DA targets (receptors, transporters, or relevant enzymes) in healthy adults (N = 95 studies including 2611 participants). Results revealed significant moderate to large, negative effects of age on DA transporters and receptors. Age had a significantly larger effect on D1- than D2-like receptors. In contrast, there was no significant effect of age on DA synthesis capacity. The average age reductions across the DA system were 3.7%-14.0% per decade. A meta-regression found only DA target as a significant moderator of the age effect. This study precisely quantifies prior claims of reduced DA functionality with age. It also identifies presynaptic mechanisms (spared synthesis capacity and reduced DA transporters) that may partially account for previously unexplained phenomena whereby older adults appear to use dopaminergic resources effectively. Recommendations for future studies including minimum required samples sizes are provided. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

A Noninvasive Imaging Approach to Understanding Speech Changes following Deep Brain Stimulation in Parkinson's Disease

ERIC Educational Resources Information Center

Narayana, Shalini; Jacks, Adam; Robin, Donald A.; Poizner, Howard; Zhang, Wei; Franklin, Crystal; Liotti, Mario; Vogel, Deanie; Fox, Peter T.

2009-01-01

Purpose: To explore the use of noninvasive functional imaging and "virtual" lesion techniques to study the neural mechanisms underlying motor speech disorders in Parkinson's disease. Here, we report the use of positron emission tomography (PET) and transcranial magnetic stimulation (TMS) to explain exacerbated speech impairment following…

Brain-Based Learning. Research Brief

ERIC Educational Resources Information Center

Walker, Karen

2005-01-01

What does brain-based research say about how adolescents learn? The 1990s was declared as the Decade of the Brain by President Bush and Congress. With the advancement of MRIs (Magnetic Resonance Imagining) and PET (positron emission tomography) scans, it has become much easier to study live healthy brains. As a result, the concept of…

INNOVATIVE APPROACH FOR MEASURING AMMONIA AND METHANE FLUXES FROM A HOG FARM USING OPEN-PATH FOURIER TRANSFORM INFRARED SPECTROSCOPY

EPA Science Inventory

The paper describes a new approach to quantify emissions from area air pollution sources. The approach combines path-integrated concentration data acquired with any path-integrated optical remote sensing (PI-ORS) technique and computed tomography (CT) technique. In this study, an...

Modeling Dynamic Functional Neuroimaging Data Using Structural Equation Modeling

ERIC Educational Resources Information Center

Price, Larry R.; Laird, Angela R.; Fox, Peter T.; Ingham, Roger J.

2009-01-01

The aims of this study were to present a method for developing a path analytic network model using data acquired from positron emission tomography. Regions of interest within the human brain were identified through quantitative activation likelihood estimation meta-analysis. Using this information, a "true" or population path model was then…

Longitudinal Cerebral Blood Flow Changes during Speech in Hereditary Ataxia

ERIC Educational Resources Information Center

Sidtis, John J.; Strother, Stephen C.; Naoum, Ansam; Rottenberg, David A.; Gomez, Christopher

2010-01-01

The hereditary ataxias constitute a group of degenerative diseases that progress over years or decades. With principal pathology involving the cerebellum, dysarthria is an early feature of many of the ataxias. Positron emission tomography was used to study regional cerebral blood flow changes during speech production over a 21 month period in a…

Genomics, proteomics, MEMS and SAIF: which role for diagnostic imaging?

PubMed

Grassi, R; Lagalla, R; Rotondo, A

2008-09-01

In these three words--genomics, proteomics and nanotechnologies--is the future of medicine of the third millennium, which will be characterised by more careful attention to disease prevention, diagnosis and treatment. Molecular imaging appears to satisfy this requirement. It is emerging as a new science that brings together molecular biology and in vivo imaging and represents the key for the application of personalized medicine. Micro-PET (positron emission tomography), micro-SPECT (single photon emission computed tomography), micro-CT (computed tomography), micro-MR (magnetic resonance), micro-US (ultrasound) and optical imaging are all molecular imaging techniques, several of which are applied only in preclinical settings on animal models. Others, however, are applied routinely in both clinical and preclinical setting. Research on small animals allows investigation of the genesis and development of diseases, as well as drug efficacy and the development of personalized therapies, through the study of biological processes that precede the expression of common symptoms of a pathology. Advances in molecular imaging were made possible only by collaboration among scientists in the fields of radiology, chemistry, molecular and cell biology, physics, mathematics, pharmacology, gene therapy and oncology. Although until now researchers have traditionally limited their interactions, it is only by increasing these connections that the current gaps in terminology, methods and approaches that inhibit scientific progress can be eliminated.

Triple primary malignancies of surface osteosarcoma of jaw, myelodysplastic syndrome and colorectal cancer as a second primary cancer detected by PET2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography: A case report.

PubMed

Maruyama, Nobuyuki; Nishihara, Kazuhide; Nakasone, Toshiyuki; Saio, Masanao; Maruyama, Tessho; Tedokon, Iori; Ohira, Tetsuya; Nimura, Fumikazu; Matayoshi, Akira; Karube, Ken-Nosuke; Yoshimi, Naoki; Arasaki, Akira

2018-06-01

Second primary malignancy (SPM) is a severe issue for cancer survivors, particularly for osteosarcoma (OS) survivors. To date, the associations between subsequent SPM and OS have been well reported. Hematogenic and solid malignancies tend to occur following OS treatment. Reportedly, 2-[ 18 F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) is mainly used in OS patients for initial cancer staging, to evaluate the response of neoadjuvant chemotherapy, and when recurrence or metastasis is clinically suspected. The present case report describes a 70-year-old man diagnosed with three primary malignancies: jaw OS, myelodysplastic syndrome and colorectal adenocarcinoma. To the best of our knowledge, this combination of malignancies has not been reported previously. Until now, there is no specific protocol of postoperative FDG-PET for OS patients. Few studies have described OS follow-up methods; therefore, there is no consensus on proper follow-up methods. In the present case report, the colorectal early-stage SPM was observed, without any symptoms, by FDG-PET/computed tomography. To avoid overlooking solid SPMs, it is suggested that FDG-PET should be performed in the long-term follow-up of OS patients.

Application of fluorodeoxyglucose positron emission tomography in the management of head and neck cancers

PubMed Central

Siddiqui, Farzan; Yao, Min

2014-01-01

The use of fluorodeoxyglucose positron emission tomography (FDG PET) scan technology in the management of head and neck cancers continues to increase. We discuss the biology of FDG uptake in malignant lesions and also discuss the physics of PET imaging. The various parameters described to quantify FDG uptake in cancers including standardized uptake value, metabolic tumor volume and total lesion glycolysis are presented. PET scans have found a significant role in the diagnosis and staging of head and neck cancers. They are also being increasingly used in radiation therapy treatment planning. Many groups have also used PET derived values to serve as prognostic indicators of outcomes including loco-regional control and overall survival. FDG PET scans are also proving very useful in assessing the efficacy of treatment and management and follow-up of head and neck cancer patients. This review article focuses on the role of FDG-PET computed tomography scans in these areas for squamous cell carcinoma of the head and neck. We present the current state of the art and speculate on the future applications of this technology including protocol development, newer imaging methods such as combined magnetic resonance and PET imaging and novel radiopharmaceuticals that can be used to further study tumor biology. PMID:24976927

Dual tracer imaging of SPECT and PET probes in living mice using a sequential protocol

PubMed Central

Chapman, Sarah E; Diener, Justin M; Sasser, Todd A; Correcher, Carlos; González, Antonio J; Avermaete, Tony Van; Leevy, W Matthew

2012-01-01

Over the past 20 years, multimodal imaging strategies have motivated the fusion of Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) scans with an X-ray computed tomography (CT) image to provide anatomical information, as well as a framework with which molecular and functional images may be co-registered. Recently, pre-clinical nuclear imaging technology has evolved to capture multiple SPECT or multiple PET tracers to further enhance the information content gathered within an imaging experiment. However, the use of SPECT and PET probes together, in the same animal, has remained a challenge. Here we describe a straightforward method using an integrated trimodal imaging system and a sequential dosing/acquisition protocol to achieve dual tracer imaging with 99mTc and 18F isotopes, along with anatomical CT, on an individual specimen. Dosing and imaging is completed so that minimal animal manipulations are required, full trimodal fusion is conserved, and tracer crosstalk including down-scatter of the PET tracer in SPECT mode is avoided. This technique will enhance the ability of preclinical researchers to detect multiple disease targets and perform functional, molecular, and anatomical imaging on individual specimens to increase the information content gathered within longitudinal in vivo studies. PMID:23145357

Radioisotope generators for short-lived positron emitters applicable to positron emission tomography

NASA Astrophysics Data System (ADS)

Yano, Y.

1989-04-01

Radioisotope generators provide short-lived positron emitters for positron emission tomography (PET) without the need for an on-site cyclotron. These generators consist of a long-lived parent radionuclide, generally produced on an accelerator, from which the short-lived daughter radionuclide is separated and used as needed. Generators developed and applied to PET studies include 288 d 68Ge for 68 min 68Ga, 25 d 82Sr for 76 s 82Rb and 20.1 h 122Xe for 3.6 min 122I. These radiotracers have been used for the assessment of myocardial and brain blood flow in patient studies. Additionally, 82Rb has been used to determine the breakdown in the blood brain barrier in brain tumor patients who have undergone radiation therapy. When used in conjunction with 18F-fluorodeoxylucose produced on a regional cyclotron for the measurement of glucose utilization in brain tumors, differential diagnosis can be made between tumor regrowth and radiation therapy necrosis. Other possible applications include the detection of vascular lesions with 68Ga labeled platelets or porphyrins.

Cobalt-55 positron emission tomography in traumatic brain injury: a pilot study.

PubMed Central

Jansen, H M; van der Naalt, J; van Zomeren, A H; Paans, A M; Veenma-van der Duin, L; Hew, J M; Pruim, J; Minderhoud, J M; Korf, J

1996-01-01

Traumatic brain injury is usually assessed with the Glasgow coma scale (GCS), CT, or MRI. After such injury, the injured brain tissue is characterised by calcium mediated neuronal damage and inflammation. Positron emission tomography with the isotope cobalt-55 (Co-PET) as a calcium tracer enables imaging of affected tissue in traumatic brain injury. The aim was to determine whether additional information can be gained by Co-PET in the diagnosis of moderate traumatic brain injury and to assess any prognostic value of Co-PET. Five patients with recent moderately severe traumatic brain injury were studied. CT was performed on the day of admission, EEG within one week, and MRI and Co-PET within four weeks of injury. Clinical assessment included neurological examination, GCS, neuropsychological testing, and Glasgow outcome scale (GOS) after one year. Co-PET showed focal uptake that extended beyond the morphological abnormalities shown by MRI and CT, in brain regions that were actually diagnosed with EEG. Thus Co-PET is potentially useful for diagnostic localisation of both structural and functional abnormalities in moderate traumatic brain injury. Images PMID:8708661

Striatal and extrastriatal dopamine release in the common marmoset brain measured by positron emission tomography and [(18)F]fallypride.

PubMed

Ota, Miho; Ogawa, Shintaro; Kato, Koichi; Masuda, Chiaki; Kunugi, Hiroshi

2015-12-01

Previous studies have demonstrated that patients with schizophrenia show greater sensitivity to psychostimulants than healthy subjects. Sensitization to psychostimulants and resultant alteration of dopaminergic neurotransmission in rodents has been suggested as a useful model of schizophrenia. This study sought to examine the use of methylphenidate as a psychostimulant to induce dopamine release and that of [(18)F]fallypride as a radioligand to quantify the release in a primate model of schizophrenia. Four common marmosets were scanned by positron emission tomography twice, before and after methylphenidate challenge, to evaluate dopamine release. Four other marmosets were sensitized by repeated methamphetamine (MAP) administration. Then, they were scanned twice, before and after methylphenidate challenge, to evaluate whether MAP-sensitization induced greater sensitivity to methylphenidate. We revealed a main effect of the methylphenidate challenge but not the MAP pretreatment on the striatal binding potential. These results suggest that methylphenidate-induced striatal dopamine release in the common marmoset could be evaluated by [(18)F]fallypride. Copyright © 2015 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Brain single photon emission computed tomography in neonates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Denays, R.; Van Pachterbeke, T.; Tondeur, M.

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.more » 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.« less

Epidural premotor cortical stimulation in primary focal dystonia: clinical and 18F-fluoro deoxyglucose positron emission tomography open study.

PubMed

Lalli, Stefania; Piacentini, Sylvie; Franzini, Angelo; Panzacchi, Andrea; Cerami, Chiara; Messina, Giuseppe; Ferré, Francesca; Perani, Daniela; Albanese, Alberto

2012-04-01

The aim of this study was to evaluate the efficacy and safety of epidural premotor stimulation in patients with primary focal dystonia. Seven patients were selected: 6 had cervical dystonia and 1 had right upper limb dystonia. In 2 patients, sustained muscle contractions led to a prevalently fixed head posture. Patients with cervical dystonia received a bilateral implant, whereas the patient with hand dystonia received a unilateral implant. Neurological and neuropsychological evaluations were performed before surgery (baseline), and 1, 3, 6, and 12 months afterward. The Burke-Fahn-Marsden scale (BFMS) and the Toronto Western spasmodic torticollis rating scale (TWSTRS) were administered at the same time points. Patients underwent resting (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) scans, before and 12 months after surgery. No adverse events occurred. An overall improvement was observed on the BFMS and TWSTRS after surgery. Patients with prevalently fixed cervical dystonia had a reduced benefit. Presurgical neuroimaging revealed a significant bilateral metabolic increase in the sensorimotor areas, which was reduced after surgery. Copyright © 2012 Movement Disorder Society.

Brain response to putative pheromones in lesbian women

PubMed Central

Berglund, Hans; Lindström, Per; Savic, Ivanka

2006-01-01

The progesterone derivative 4,16-androstadien-3-one (AND) and the estrogen-like steroid estra-1,3,5(10),16-tetraen-3-ol (EST) are candidate compounds for human pheromones. In previous positron emission tomography studies, we found that smelling AND and EST activated regions primarily incorporating the sexually dimorphic nuclei of the anterior hypothalamus, that this activation was differentiated with respect to sex and compound, and that homosexual men processed AND congruently with heterosexual women rather than heterosexual men. These observations indicate involvement of the anterior hypothalamus in physiological processes related to sexual orientation in humans. We expand the information on this issue in the present study by performing identical positron emission tomography experiments on 12 lesbian women. In contrast to heterosexual women, lesbian women processed AND stimuli by the olfactory networks and not the anterior hypothalamus. Furthermore, when smelling EST, they partly shared activation of the anterior hypothalamus with heterosexual men. These data support our previous results about differentiated processing of pheromone-like stimuli in humans and further strengthen the notion of a coupling between hypothalamic neuronal circuits and sexual preferences. PMID:16705035

Neurobiological findings related to Internet use disorders.

PubMed

Park, Byeongsu; Han, Doug Hyun; Roh, Sungwon

2017-07-01

In the last 10 years, numerous neurobiological studies have been conducted on Internet addiction or Internet use disorder. Various neurobiological research methods - such as magnetic resonance imaging; nuclear imaging modalities, including positron emission tomography and single photon emission computed tomography; molecular genetics; and neurophysiologic methods - have made it possible to discover structural or functional impairments in the brains of individuals with Internet use disorder. Specifically, Internet use disorder is associated with structural or functional impairment in the orbitofrontal cortex, dorsolateral prefrontal cortex, anterior cingulate cortex, and posterior cingulate cortex. These regions are associated with the processing of reward, motivation, memory, and cognitive control. Early neurobiological research results in this area indicated that Internet use disorder shares many similarities with substance use disorders, including, to a certain extent, a shared pathophysiology. However, recent studies suggest that differences in biological and psychological markers exist between Internet use disorder and substance use disorders. Further research is required for a better understanding of the pathophysiology of Internet use disorder. © 2016 The Authors. Psychiatry and Clinical Neurosciences published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Psychiatry and Neurology.

Contrast-enhanced [18F] fluorodeoxyglucose-positron emission tomography-computed tomography as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin

PubMed Central

Jain, Avani; Srivastava, Madhur Kumar; Pawaskar, Alok Suresh; Shelley, Simon; Elangovan, Indirani; Jain, Hasmukh; Pandey, Somnath; Kalal, Shilpa; Amalachandran, Jaykanth

2015-01-01

Background: To evaluate the advantages of contrast enhanced F-18-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-contrast enhanced CT [CECT]) when used as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin (MUO). Materials and Methods: A total of 243 patients with fine needle aspiration cytology/biopsy proven MUO were included in this prospective study. Patients who were thoroughly evaluated for primary or primary tumor was detected by any other investigation were excluded from the analysis. Totally, 163 patients with pathological diagnosis of malignancy but no apparent sites of the primary tumor were finally selected for analysis. The site of probable primary malignancy suggested by PET-CECT was confirmed by biopsy/follow-up. Results: PET-CECT suggested probable site of primary in 128/163 (78.52%) patients. In 30/35 remaining patients, primary tumor was not detected even after extensive work-up. In 5 patients, where PET-CECT was negative, primary was found on further extensive investigations or follow-up. The sensitivity, specificity, positive predictive value and negative predictive value of the study were 95.76%, 66.67%, 88.28% and 85.71% respectively. Conclusions: F-18 FDG PET-CECT aptly serves the purpose of initial imaging modality owing to high sensitivity, negative and positive predictive value. PET-CECT not only surveys the whole body for the primary malignancy but also stages the disease accurately. Use of contrast improves the diagnostic utility of modality as well as help in staging of the primary tumor. Although benefits of using PET-CECT as initial diagnostic modality are obvious from this study, there is a need for a larger study comparing conventional methods for diagnosing primary in patients with MUO versus PET-CECT. PMID:26170563

Sub-core permeability and relative permeability characterization with Positron Emission Tomography

NASA Astrophysics Data System (ADS)

Zahasky, C.; Benson, S. M.

2017-12-01

This study utilizes preclinical micro-Positron Emission Tomography (PET) to image and quantify the transport behavior of pulses of a conservative aqueous radiotracer injected during single and multiphase flow experiments in a Berea sandstone core with axial parallel bedding heterogeneity. The core is discretized into streamtubes, and using the micro-PET data, expressions are derived from spatial moment analysis for calculating sub-core scale tracer flux and pore water velocity. Using the flux and velocity data, it is then possible to calculate porosity and saturation from volumetric flux balance, and calculate permeability and water relative permeability from Darcy's law. Full 3D simulations are then constructed based on this core characterization. Simulation results are compared with experimental results in order to test the assumptions of the simple streamtube model. Errors and limitations of this analysis will be discussed. These new methods of imaging and sub-core permeability and relative permeability measurements enable experimental quantification of transport behavior across scales.

Muscarinic cholinergic receptor binding: in vivo depiction using single photon emission computed tomography and radioiodinated quinuclidinyl benzilate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drayer, B.; Jaszczak, R.; Coleman, E.

1982-06-01

An attempt was made to characterize, in vivo, specific binding to the muscarinic cholinergic receptor in the calf using the radioiodinated ligand quinuclidinyl benzilate (/sup 123/I-OH-QNB) and single photon detection emission computed tomography (SPECT). The supratentorial brain activity was significantly increased after the intravenous infusion of /sup 123/I-OH-QNB as compared to free /sup 123/I. Scopolamine, a muscarinic cholinergic receptor antagonist, decreased the measured brain activity when infused prior to /sup 123/I-OH-QNB consistent with pharmacologic blockade of specific receptor binding. Quantitative in vitro tissue distribution studies obtained following SPECT imaging were consistent with regionally distinct specific receptor binding in the striatummore » and cortical gray matter, nonspecific binding in the cerebellum, and pharmacologic blockade of specific binding sites with scopolamine. Although /sup 123/I-OH-QNB is not the ideal radioligand, our limited success will hopefully encourage the development of improved binding probes for SPECT imaging and quantitation.« less

[Fluorodeoxiglucose F18 positron emission tomography imaging (F18FDG) for the assessment of rising levels of serum CA 19-9 in pancreatic mucinous cystadenocarcinoma. Report of one case].

PubMed

Canessa, José A; Larach, Jorge A; Massardo, Teresa; Parra, Juan; Jofré, Josefina; González, Patricio; Morales, Bernardo; Humeres, Pamela; Sierralta, Paulina; Galaz, Rodrigo

2004-03-01

We report a 38 year old female patient with a pancreatic mucinous cystadenocarcinoma. She presented at the onset with a peritoneal rupture that required emergency surgery. Five months later, the patient was subjected to a segmental pancreatectomy and splenectomy. One year later, the patient had a serious gastric bleeding secondary to a gastric ulcer. Due to a persistent increase in her CA 19-9 levels, a Positron Emission Tomography (PET) functional imaging with fluorine 18-deoxyglucose (F18FDG) was done. It showed an intense focal hypermetabolism in the gastric wall reported as a secondary tumour location. The patient was subjected to a total gastrectomy and Roux en Y anastomosis, with a good outcome. The pathological study confirmed the presence of a metastasis of an adenocarcinoma in the gastric wall. The relative value of CA 19-9 markers and FDG PET in pancreatic and gastric carcinomas is discussed.

A case of temporal lobe epilepsy with improvement of clinical symptoms and single photon emission computed tomography findings after treatment with clonazepam.

PubMed

Ide, M; Mizukami, K; Suzuki, T; Shiraishi, H

2000-10-01

A 26-year-old female presented psychomotor seizures, deja vu and amnestic syndrome after meningitis at the age of 14 years. Repeated electroencephalograms (EEG) demonstrated occasional spikes localized in the right temporal region in addition to a considerable amount of theta waves mainly in the right fronto-temporal region. Single photon emission computed tomography (SPECT) showed a marked hypoperfusion corresponding to the region in which the EEG showed abnormal findings, although magnetic resonance imaging (MRI) demonstrated no abnormal findings associated with the clinical features. Treatment with clonazepam in addition to sodium valproate resulted in a remarkable improvement of clinical symptoms (i.e. psychomotor seizures and deja vu), as well as of the EEG and SPECT findings. The present study suggests that SPECT is a useful method not only to determine the localization of regions associated with temporal lobe epilepsy but also to evaluate the effect of treatment in temporal lobe epilepsy.

Non-invasive mapping of deep-tissue lymph nodes in live animals using a multimodal PET/MRI nanoparticle

NASA Astrophysics Data System (ADS)

Thorek, Daniel L. J.; Ulmert, David; Diop, Ndeye-Fatou M.; Lupu, Mihaela E.; Doran, Michael G.; Huang, Ruimin; Abou, Diane S.; Larson, Steven M.; Grimm, Jan

2014-01-01

The invasion status of tumour-draining lymph nodes (LNs) is a critical indicator of cancer stage and is important for treatment planning. Clinicians currently use planar scintigraphy and single-photon emission computed tomography (SPECT) with 99mTc-radiocolloid to guide biopsy and resection of LNs. However, emerging multimodality approaches such as positron emission tomography combined with magnetic resonance imaging (PET/MRI) detect sites of disease with higher sensitivity and accuracy. Here we present a multimodal nanoparticle, 89Zr-ferumoxytol, for the enhanced detection of LNs with PET/MRI. For genuine translational potential, we leverage a clinical iron oxide formulation, altered with minimal modification for radiolabelling. Axillary drainage in naive mice and from healthy and tumour-bearing prostates was investigated. We demonstrate that 89Zr-ferumoxytol can be used for high-resolution tomographic studies of lymphatic drainage in preclinical disease models. This nanoparticle platform has significant translational potential to improve preoperative planning for nodal resection and tumour staging.

Design of a serotonin 4 receptor radiotracer with decreased lipophilicity for single photon emission computed tomography.

PubMed

Fresneau, Nathalie; Dumas, Noé; Tournier, Benjamin B; Fossey, Christine; Ballandonne, Céline; Lesnard, Aurélien; Millet, Philippe; Charnay, Yves; Cailly, Thomas; Bouillon, Jean-Philippe; Fabis, Frédéric

2015-04-13

With the aim to develop a suitable radiotracer for the brain imaging of the serotonin 4 receptor subtype (5-HT4R) using single photon emission computed tomography (SPECT), we synthesized and evaluated a library of di- and triazaphenanthridines with lipophilicity values which were in the range expected to favour brain penetration, and which demonstrated specific binding to the target of interest. Adding additional nitrogen atoms to previously described phenanthridine ligands exhibiting a high unspecific binding, we were able to design a radioiodinated compound [(125)I]14. This compound exhibited a binding affinity value of 0.094 nM toward human 5-HT4R and a high selectivity over other serotonin receptor subtypes (5-HTR). In vivo SPECT imaging studies and competition experiments demonstrated that the decreased lipophilicity (in comparison with our previously reported compounds 4 and 5) allowed a more specific labelling of the 5-HT4R brain-containing regions. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Correlative studies of structural and functional imaging in primary progressive aphasia.

PubMed

Panegyres, P K; McCarthy, M; Campbell, A; Lenzo, N; Fallon, M; Thompson, J

2008-01-01

To compare and contrast structural and functional imaging in primary progressive aphasia (PPA). A cohort of 8 patients diagnosed with PPA presenting with nonfluency were prospectively evaluated. All patients had structural imaging in the form of MRI and in 1 patient CAT scanning on account of a cardiac pacemaker. All patients had single-photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging. SPECT and PET imaging had 100% correlation. Anatomical imaging was abnormal in only 6 of the 8 patients. Wernicke's area showed greater peak Z score reduction and extent of area affected than Broca's area (McNemar paired test: P = .008 for Z score reduction; P = .0003 for extent). PET scanning revealed significant involvement of the anterior cingulum. Functional imaging in PPA: (a) identified more patients correctly than anatomic imaging highlighting the importance of SPECT and PET in the diagnosis; and (b) demonstrated the heterogeneous involvement of disordered linguistic networks in PPA suggesting its syndromic nature.

Positron emission tomography (PET) imaging with 18F-based radiotracers

PubMed Central

Alauddin, Mian M

2012-01-01

Positron Emission Tomography (PET) is a nuclear medicine imaging technique that is widely used in early detection and treatment follow up of many diseases, including cancer. This modality requires positron-emitting isotope labeled biomolecules, which are synthesized prior to perform imaging studies. Fluorine-18 is one of the several isotopes of fluorine that is routinely used in radiolabeling of biomolecules for PET; because of its positron emitting property and favorable half-life of 109.8 min. The biologically active molecule most commonly used for PET is 2-deoxy-2-18F-fluoro-β-D-glucose (18F-FDG), an analogue of glucose, for early detection of tumors. The concentrations of tracer accumulation (PET image) demonstrate the metabolic activity of tissues in terms of regional glucose metabolism and accumulation. Other tracers are also used in PET to image the tissue concentration. In this review, information on fluorination and radiofluorination reactions, radiofluorinating agents, and radiolabeling of various compounds and their application in PET imaging is presented. PMID:23133802

Lumbosacral Radiculoplexopathy as the Initial Presentation of Lymphoma: A Report of 4 Cases.

PubMed

Marquardt, Robert J; Li, Yuebing

2018-06-01

To evaluate the clinical, laboratory, and radiological features of 4 cases of biopsy-proven lymphomatous lumbosacral radiculoplexopathy. Retrospective chart review. All patients suffered from diffuse large B-cell lymphoma. A mean diagnostic delay of 10 months was encountered. Presenting symptoms in all 4 patients included back pain, radicular leg pain, and leg weakness, similar to spondylotic radiculopathy. Electrodiagnostic study showed axon loss radiculoplexopathy and magnetic resonance imaging of the lumbar spine or pelvis demonstrated nerve or nerve root enhancement. Increased uptake by lumbosacral roots/plexus on fluorodeoxyglucose-positron emission tomography aided diagnosis in 3 cases. Cytology was positive in 1 of 10 cerebrospinal fluid samples. Combined chemotherapy and radiation treatment led to clinicoradiological improvement, with residual neurological symptoms in all patients. Lymphomatous lumbosacral radiculoplexopathy should be considered in patients with progressive lumbosacral radicular symptoms. Magnetic resonance imaging and fluorodeoxyglucose-positron emission tomography, but not cerebrospinal fluid, are helpful in achieving early diagnosis. Treatment responses seem favorable.

Regional cerebral blood flow (rCBF) in schizophrenia during verbal memory activation: a 99mTc-HMPAO single photon emission tomography (SPET) study.

PubMed

Busatto, G F; Costa, D C; Ell, P J; Pilowsky, L S; David, A S; Kerwin, R W

1994-05-01

Regional cerebral blood flow (rCBF) was investigated in a group of medicated DSM-III-R schizophrenic patients and age, sex and handedness matched normal volunteers using a split-dose 99mTc-HMPAO Single Photon Emission Tomography (SPET) protocol. Measures were taken during the performance of a verbal memory task aimed at activating the left medial temporal lobe, a region repeatedly suggested to be structurally abnormal in schizophrenia. In normal subjects, the performance of the task was associated with significant rCBF increases in the left medial temporal, left inferior frontal and anterior cingulate cortices, and right cerebellum. Despite their significantly poorer performance on the memory task, the degree of medial temporal activation measured in the schizophrenic patients was not significantly different from that found in the control group. This finding suggests that memory deficits in schizophrenia do not necessarily imply failure to activate the left medial temporal lobe as assessed by 99mTc-HMPAO SPET.

Neurokinin-3 Receptor Binding in Guinea Pig, Monkey, and Human Brain: In Vitro and in Vivo Imaging Using the Novel Radioligand, [18F]Lu AF10628.

PubMed

Varnäs, Katarina; Finnema, Sjoerd J; Stepanov, Vladimir; Takano, Akihiro; Tóth, Miklós; Svedberg, Marie; Møller Nielsen, Søren; Khanzhin, Nikolay A; Juhl, Karsten; Bang-Andersen, Benny; Halldin, Christer; Farde, Lars

2016-08-01

Previous autoradiography studies have suggested a marked interspecies variation in the neuroanatomical localization and expression levels of the neurokinin 3 receptor, with high density in the brain of rat, gerbil, and guinea pig, but at the time offered no conclusive evidence for its presence in the human brain. Hitherto available radioligands have displayed low affinity for the human neurokinin 3 receptor relative to the rodent homologue and may thus not be optimal for cross-species analyses of the expression of this protein. A novel neurokinin 3 receptor radioligand, [(18)F]Lu AF10628 ((S)-N-(cyclobutyl(3-fluorophenyl)methyl)-8-fluoro-2-((3-[(18)F]-fluoropropyl)amino)-3-methyl-1-oxo-1,2-dihydroisoquinoline-4-carboxamide), was synthesized and used for autoradiography studies in cryosections from guinea pig, monkey, and human brain as well as for positron emission tomography studies in guinea pig and monkey. The results confirmed previous observations of interspecies variation in the neurokinin 3 receptor brain localization with more extensive distribution in guinea pig than in primate brain. In the human brain, specific binding to the neurokinin 3 receptor was highest in the amygdala and in the hypothalamus and very low in other regions examined. Positron emission tomography imaging showed a pattern consistent with that observed using autoradiography. The radioactivity was, however, found to accumulate in skull bone, which limits the use of this radioligand for in vivo quantification of neurokinin 3 receptor binding. Species differences in the brain distribution of neurokinin 3 receptors should be considered when using animal models for predicting human neurokinin 3 receptor pharmacology. For positron emission tomography imaging of brain neurokinin 3 receptors, additional work is required to develop a radioligand with more favorable in vivo properties. © The Author 2016. Published by Oxford University Press on behalf of CINP.

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography evaluation of subcutaneous panniculitis-like T cell lymphoma and treatment response

PubMed Central

Gorodetskiy, Vadim R; Mukhortova, Olga V; Aslanidis, Irakli P; Klapper, Wolfram; Probatova, Natalya A

2016-01-01

Subcutaneous panniculitis-like T cell lymphoma (SPTCL) is a very rare variant of non-Hodgkin’s lymphoma. Currently, there is no standard imaging method for staging of SPTCL nor for assessment of treatment response. Here, we describe our use of fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for staging and monitoring of treatment response in 3 cases of SPTCL. Primary staging by PET/CT showed that all 3 patients had multiple foci in the subcutaneous fat tissue, with SUVmax from 10.5 to 14.6. Involvement of intra-abdominal fat with high SUVmax was identified in 2 of the patients. Use of the triple drug regimen of gemcitabine, cisplatin and methylprednisolone (commonly known as “GEM-P”) as first-line therapy or second-line therapy facilitated complete metabolic response for all 3 cases. FDG PET/CT provides valuable information for staging and monitoring of treatment response and can reveal occult involvement of the intra-abdominal visceral fat. High FDG uptake on pre-treatment PET can identify patients with aggressive disease and help in selection of first-line therapy. PMID:27672640

Mixed spine metastasis detection through positron emission tomography/computed tomography synthesis and multiclassifier

PubMed Central

Yao, Jianhua; Burns, Joseph E.; Sanoria, Vic; Summers, Ronald M.

2017-01-01

Abstract. Bone metastases are a frequent occurrence with cancer, and early detection can guide the patient’s treatment regimen. Metastatic bone disease can present in density extremes as sclerotic (high density) and lytic (low density) or in a continuum with an admixture of both sclerotic and lytic components. We design a framework to detect and characterize the varying spectrum of presentation of spine metastasis on positron emission tomography/computed tomography (PET/CT) data. A technique is proposed to synthesize CT and PET images to enhance the lesion appearance for computer detection. A combination of watershed, graph cut, and level set algorithms is first run to obtain the initial detections. Detections are then sent to multiple classifiers for sclerotic, lytic, and mixed lesions. The system was tested on 44 cases with 225 sclerotic, 139 lytic, and 92 mixed lesions. The results showed that sensitivity (false positive per patient) was 0.81 (2.1), 0.81 (1.3), and 0.76 (2.1) for sclerotic, lytic, and mixed lesions, respectively. It also demonstrates that using PET/CT data significantly improves the computer aided detection performance over using CT alone. PMID:28612036

Sex differences in the relationship of regional dopamine release to affect and cognitive function in striatal and extrastriatal regions using positron emission tomography and [¹⁸F]fallypride.

PubMed

Riccardi, Patrizia; Park, Sohee; Anderson, Sharlet; Doop, Mikisha; Ansari, M Sib; Schmidt, Dennis; Baldwin, Ronald

2011-02-01

The purpose of this study was to examine sex differences in the correlations of d-amphetamine (d-AMPH) induced displacements of [¹⁸F]fallypride in striatal and extrastriatal regions in relation to affect and cognition. Seven male and six female healthy subjects, whose mean age was 25.9 years, underwent positron emission tomography (PET) with [¹⁸F]fallypride at baseline and 3 h after a 0.43 mg/kg oral dose of d-AMPH. Percent displacements in striatal and extrastriatal regions were calculated using regions of interest (ROI) analysis and on a pixel-by-pixel basis. Subjects underwent neuropsychological testing prior to the baseline PET study and one hour after d-AMPH administration for the second PET. In order to examine the subjective effect of d-AMPH, subjects rated PANAS at baseline and after administration of amphetamine. Correlations of changes in cognition and affect with regional dopamine (DA) release revealed several significant sex related differences. The results of this study demonstrate in vivo sex related differences in the relationship of regional DA release to affect and cognitive function. Copyright © 2010 Wiley-Liss, Inc.

Protective effects of minocycline on the reduction of dopamine transporters in the striatum after administration of methamphetamine: a positron emission tomography study in conscious monkeys.

PubMed

Hashimoto, Kenji; Tsukada, Hideo; Nishiyama, Shingo; Fukumoto, Dai; Kakiuchi, Takeharu; Iyo, Masaomi

2007-03-01

Positron emission tomography (PET) studies of methamphetamine (METH) abusers suggest that psychotic symptoms of METH abusers may be attributable to the reduction of dopamine transporters (DAT) in the human brain. However, there are currently no particular pharmacological treatments for the wide range of symptoms associated with METH abuse. Using a PET study in conscious monkeys, we investigated whether the second generation antibiotic minocycline could protect against the reduction of DAT in monkeys treated with METH (2 mg/kg x 3, 3-hour intervals). Pretreatment and subsequent administration of minocycline significantly attenuated the reduction of DAT in the striatum of monkeys treated with METH. Furthermore, posttreatment and subsequent administration of minocycline also significantly attenuated the reduction of DAT. In contrast, repeated administration of minocycline alone did not alter the density of DAT in the striatum of monkeys treated with METH. Our findings suggest that minocycline protects against METH-induced neurotoxicity in the monkey brain. Therefore, minocycline is likely to be a promising therapeutic agent for the treatment of several symptoms associated with METH use in humans.

An Automatic Method for Generating an Unbiased Intensity Normalizing Factor in Positron Emission Tomography Image Analysis After Stroke.

PubMed

Nie, Binbin; Liang, Shengxiang; Jiang, Xiaofeng; Duan, Shaofeng; Huang, Qi; Zhang, Tianhao; Li, Panlong; Liu, Hua; Shan, Baoci

2018-06-07

Positron emission tomography (PET) imaging of functional metabolism has been widely used to investigate functional recovery and to evaluate therapeutic efficacy after stroke. The voxel intensity of a PET image is the most important indicator of cellular activity, but is affected by other factors such as the basal metabolic ratio of each subject. In order to locate dysfunctional regions accurately, intensity normalization by a scale factor is a prerequisite in the data analysis, for which the global mean value is most widely used. However, this is unsuitable for stroke studies. Alternatively, a specified scale factor calculated from a reference region is also used, comprising neither hyper- nor hypo-metabolic voxels. But there is no such recognized reference region for stroke studies. Therefore, we proposed a totally data-driven automatic method for unbiased scale factor generation. This factor was generated iteratively until the residual deviation of two adjacent scale factors was reduced by < 5%. Moreover, both simulated and real stroke data were used for evaluation, and these suggested that our proposed unbiased scale factor has better sensitivity and accuracy for stroke studies.

Imaging Transgene Expression with Radionuclide Imaging Technologies1

PubMed Central

Gambhir, SS; Herschman, HR; Cherry, SR; Barrio, JR; Satyamurthy, N; Toyokuni, T; Phelps, ME; Larson, SM; Balaton, J; Finn, R; Sadelain, M; Tjuvajev, J

2000-01-01

Abstract A variety of imaging technologies are being investigated as tools for studying gene expression in living subjects. Noninvasive, repetitive and quantitative imaging of gene expression will help both to facilitate human gene therapy trials and to allow for the study of animal models of molecular and cellular therapy. Radionuclide approaches using single photon emission computed tomography (SPECT) and positron emission tomography (PET) are the most mature of the current imaging technologies and offer many advantages for imaging gene expression compared to optical and magnetic resonance imaging (MRI)-based approaches. These advantages include relatively high sensitivity, full quantitative capability (for PET), and the ability to extend small animal assays directly into clinical human applications. We describe a PET scanner (micro PET) designed specifically for studies of small animals. We review “marker/reporter gene” imaging approaches using the herpes simplex type 1 virus thymidine kinase (HSV1-tk) and the dopamine type 2 receptor (D2R) genes. We describe and contrast several radiolabeled probes that can be used with the HSV1-tk reporter gene both for SPECT and for PET imaging. We also describe the advantages/disadvantages of each of the assays developed and discuss future animal and human applications. PMID:10933072

Evaluation of positron emission tomography as a method to visualize subsurface microbial processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinsella K.; Schlyer D.; Kinsella, K.

2012-01-18

Positron emission tomography (PET) provides spatiotemporal monitoring in a nondestructive manner and has higher sensitivity and resolution relative to other tomographic methods. Therefore, this technology was evaluated for its application to monitor in situ subsurface bacterial activity. To date, however, it has not been used to monitor or image soil microbial processes. In this study, PET imaging was applied as a 'proof-of-principle' method to assess the feasibility of visualizing a radiotracer labeled subsurface bacterial strain (Rahnella sp. Y9602), previously isolated from uranium contaminated soils and shown to promote uranium phosphate precipitation. Soil columns packed with acid-purified simulated mineral soils weremore » seeded with 2-deoxy-2-[{sup 18}F]fluoro-d-glucose ({sup 18}FDG) labeled Rahnella sp. Y9602. The applicability of [{sup 18}F]fluoride ion as a tracer for measuring hydraulic conductivity and {sup 18}FDG as a tracer to identify subsurface metabolically active bacteria was successful in our soil column studies. Our findings indicate that positron-emitting isotopes can be utilized for studies aimed at elucidating subsurface microbiology and geochemical processes important in contaminant remediation.« less

Incidence of a single subsegmental mismatched perfusion defect in single-photon emission computed tomography and planar ventilation/perfusion scans.

PubMed

Stubbs, Matthew; Chan, Kenneth; McMeekin, Helena; Navalkissoor, Shaunak; Wagner, Thomas

2017-02-01

This study aims to compare the incidence of ventilation/perfusion (V/Q) scans interpreted as indeterminate for the diagnosis of pulmonary embolism (PE) using single-photon emission computed tomography (SPECT) versus planar scintigraphy and to consider the effect of variable interpretation of single subsegmental V/Q mismatch (SSM). A total of 1300 consecutive V/Q scans were retrospectively reviewed. After exclusion and matching for age and sex, 542 SPECT and 589 planar scans were included in the analysis. European Association of Nuclear Medicine guidelines were used to interpret the V/Q scans, initially interpreting SSM as negative scans. Patients with SSM were followed up for 3 months and further imaging for PE was collected. Indeterminate scans were significantly fewer in the SPECT than the planar group on the basis of the initial report (7.7 vs. 12.2%, P<0.05). This is irrespective of classification of SSM as a negative scan (4.6 vs. 12.1%, P<0.0001) or an indeterminate scan (8.3 vs. 12.2%, P<0.05). Of the 21 patients who had SSM, 19 underwent computer tomography pulmonary angiogram and embolism was found in one patient. None of these patients died at the 3-month follow-up. V/Q SPECT has greater diagnostic certainty of PE, with a 41% reduction in an indeterminate scan compared with planar scintigraphy. This is irrespective of the clinician's interpretation of SSM as negative or intermediate probability. Patients with SSM would not require further computer tomography pulmonary angiogram imaging.

What is the role of florine-18 fluorodeoxyglucose/positron emission tomography/computed tomography imaging in well-differentiated thyroid cancers with negative iodine-131 scan high thyroglobulin and normal anti-thyroglobulin levels.

PubMed

Döner, Rana Kaya; Sager, Sait; Görtan, Fatma Arzu; Topuz, Özge Vural; Akyel, Reşit; Vatankulu, Betül; Baran, Ahmet; Teksoz, Serkan; Sönmezoglu, Kerim

2016-01-01

This retrospective study aims to assess the cut-off value of thyroglobulin (Tg) levels in nux or metastatic well-differentiated thyroid cancers (DTCs) with normal anti-Tg levels using with fluorodeoxyglucose/positron emission tomography/computed tomography (FDG PET/CT). We reviewed FDG PET/CT images of 104 patients with well DTC (28 men, 76 women) whose: Iodine-131 (131 I) whole-body scanning was negative but had elevated Tg with normal anti-Tg levels. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of florine-18-FDG PET/CT findings were found to be 95.92%, 87.27%, 87.04%, 96.00%, and 91.35%, respectively. The best Tg cut-off value was found to be 10.4 ng/ml. In the Tg level <10.4 ng/ml group, the sensitivity, specificity, PPV, NPV, and accuracy of FDG PET/CT were found to be 94.1%, 91.30%, 88.8%, 95.4%, and 92.5%, respectively. In the other group, which Tg level ≥10.4 ng/ml, sensitivity, specificity, PPV, NPV, and accuracy of FDG PET/CT exams were found to be 96.8%, 84.3%, 86.1%, 96.4%, and 90.6%, respectively. FDG PET/CT imaging is a valuable imaging method in the evaluation of patients with elevated serum Tg levels and normal anti-Tg levels. Furthermore, it has potential utility in the dedifferentiation of active foci that are present, and in assessing optimal decision making during follow-up.

Cone-beam computed tomography fusion and navigation for real-time positron emission tomography-guided biopsies and ablations: a feasibility study.

PubMed

Abi-Jaoudeh, Nadine; Mielekamp, Peter; Noordhoek, Niels; Venkatesan, Aradhana M; Millo, Corina; Radaelli, Alessandro; Carelsen, Bart; Wood, Bradford J

2012-06-01

To describe a novel technique for multimodality positron emission tomography (PET) fusion-guided interventions that combines cone-beam computed tomography (CT) with PET/CT before the procedure. Subjects were selected among patients scheduled for a biopsy or ablation procedure. The lesions were not visible with conventional imaging methods or did not have uniform uptake on PET. Clinical success was defined by adequate histopathologic specimens for molecular profiling or diagnosis and by lack of enhancement on follow-up imaging for ablation procedures. Time to target (time elapsed between the completion of the initial cone-beam CT scan and first tissue sample or treatment), total procedure time (time from the moment the patient was on the table until the patient was off the table), and number of times the needle was repositioned were recorded. Seven patients underwent eight procedures (two ablations and six biopsies). Registration and procedures were completed successfully in all cases. Clinical success was achieved in all biopsy procedures and in one of the two ablation procedures. The needle was repositioned once in one biopsy procedure only. On average, the time to target was 38 minutes (range 13-54 min). Total procedure time was 95 minutes (range 51-240 min, which includes composite ablation). On average, fluoroscopy time was 2.5 minutes (range 1.3-6.2 min). An integrated cone-beam CT software platform can enable PET-guided biopsies and ablation procedures without the need for additional specialized hardware. Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.

Early Changes by 18Fluorodeoxyglucose Positron Emission Tomography Coregistered with Computed Tomography Predict Outcome after Mycobacterium tuberculosis Infection in Cynomolgus Macaques

PubMed Central

Coleman, M. Teresa; Maiello, Pauline; Tomko, Jaime; Frye, Lonnie James; Fillmore, Daniel; Janssen, Christopher; Klein, Edwin

2014-01-01

Cynomolgus macaques infected with low-dose Mycobacterium tuberculosis develop both active tuberculosis and latent infection similar to those of humans, providing an opportunity to study the clinically silent early events in infection. 18Fluorodeoxyglucose radiotracer with positron emission tomography coregistered with computed tomography (FDG PET/CT) provides a noninvasive method to measure disease progression. We sought to determine temporal patterns of granuloma evolution that distinguished active-disease and latent outcomes. Macaques (n = 10) were infected with low-dose M. tuberculosis with FDG PET/CT performed during infection. At 24 weeks postinfection, animals were classified as having active disease (n = 3) or latent infection (n = 6), with one “percolator” monkey. Imaging characteristics (e.g., lesion number, metabolic activity, size, mineralization, and distribution of lesions) were compared among active and latent groups. As early as 3 weeks postinfection, more pulmonary granulomas were observed in animals that would later develop active disease than in those that would develop latent infection. Over time, new lesions developed in active-disease animals but not in latent animals. Granulomas and mediastinal lymph nodes from active-disease but not latent animals consistently increased in metabolic activity at early time points. The presence of fewer lesions at 3 weeks and the lack of new lesion development in animals with latent infection suggest that innate and rapid adaptive responses are critical to preventing active tuberculosis. A greater emphasis on innate responses and/or rapid recruitment of adaptive responses, especially in the airway, should be emphasized in newer vaccine strategies. PMID:24664509

Renal Manifestation of Birt-Hogg-Dubé Syndrome Depicted by 18F-fludeoxyglucose Positron Emission Tomography/Computed Tomography in a Patient with Hurtle Cell Thyroid Malignancy.

PubMed

Panagiotidis, Emmanouil; Seshadri, Nagabhushan; Vinjamuri, Sobhan

2018-01-01

Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant genetic disorder characterized by small papular skin lesions (fibrofolliculomas) causing susceptibility to kidney cancer, renal and pulmonary cysts, spontaneous pneumothoraces, and several noncutaneous tumors. We report a case of a 67-year-old woman, with a previous history of right hemithyroidectomy for adenomatous lesion. She presented with a swelling in the right thyroid bed that on subsequent biopsy revealed features of metastatic carcinoma. 18F-fludeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) performed for the detection of primary malignancy showed increased high-grade metabolic activity in the right supraclavicular soft tissue mass extending into the superior mediastinum. Moreover, on low-dose CT, there have been bilateral renal interpolar cortical lesions with mild metabolic activity. Given the fact that the right neck mass was highly unlikely to represent renal metastases in the absence of widespread metastatic disease, surgical excision of the right neck mass was performed. The histology of the mass was in keeping with hurtle cell thyroid carcinoma. In regard to renal lesions, bilateral partial nephrectomy was performed, which was consistent with chromophobe renal cell carcinoma, raising the suspicion of BHD that was confirmed by the subsequent genetic evaluation. It is well established that 18F-FDG PET/CT study is not an optimal modality for evaluation of renal lesions. However, careful assessment of the CT features in conjunction with the associated metabolic activity of the 18F-FDG PET component increases the diagnostic accuracy of PET/CT.

Role of Combined 68Ga-DOTATOC and 18F-FDG Positron Emission Tomography/Computed Tomography in the Diagnostic Workup of Pancreas Neuroendocrine Tumors: Implications for Managing Surgical Decisions.

PubMed

Cingarlini, Sara; Ortolani, Silvia; Salgarello, Matteo; Butturini, Giovanni; Malpaga, Anna; Malfatti, Veronica; DʼOnofrio, Mirko; Davì, Maria Vittoria; Vallerio, Paola; Ruzzenente, Andrea; Capelli, Paola; Citton, Elia; Grego, Elisabetta; Trentin, Chiara; De Robertis, Riccardo; Scarpa, Aldo; Bassi, Claudio; Tortora, Giampaolo

2017-01-01

Ga-DOTATOC (Ga) positron emission tomography (PET)/computed tomography (CT) is recommended in the workup of pancreas neuroendocrine tumors (PanNETs); evidence suggests that F-FDG (F) PET/CT can also provide prognostic information. Aims of this study were to assess the role of combined Ga- and F-PET/CT in the evaluation of grade (G) 1-2 PanNETs and to test the correlation between F-PET/CT positivity and tumor grade. Preoperative Ga- and F-PET/CT of 35 patients with surgically resected G1-2 PanNETs were evaluated. For grading, the 2010 World Health Organization Classification was used; an ancillary analysis with Ki67 cutoffs at 5% to 20% was conducted. Correlation between F-PET/CT positivity (SUVmax > 3.5) and grade was assessed. Of 35 PanNETs, 28.6% and 71.4% were G1 and G2 as per World Health Organization. Ga-PET/CT showed high sensitivity (94.3%) in detecting G1-2 PanNETs. F-PET/CT was positive in 20% and 76% G1 and G2 tumors (P = 0.002). F-PET/CT identified G2 PanNETs with high positive predictive value (PPV, 90.5%). F-PET/CT correlated with tumor grade also in the ancillary analysis (P = 0.009). The high sensitivity of Ga-PET/CT in NET detection is known. The high PPV of F-PET/CT in the identification of G2 forms suggests its potential role in PanNETs prognostication and risk stratification.

Seasonal influence on stimulated BAT activity in prospective trials: a retrospective analysis of BAT visualized on 18F-FDG PET-CTs and 123I-mIBG SPECT-CTs.

PubMed

Bahler, Lonneke; Deelen, Jan W; Hoekstra, Joost B; Holleman, Frits; Verberne, Hein J

2016-06-15

Retrospective studies have shown that outdoor temperature influences the prevalence of detectable brown adipose tissue (BAT). Prospective studies use acute cold exposure to activate BAT. In prospective studies, BAT might be preconditioned in winter months leading to an increased BAT response to various stimuli. Therefore the aim of this study was to assess whether outdoor temperatures and other weather characteristics modulate the response of BAT to acute cold. To assess metabolic BAT activity and sympathetic outflow to BAT, 64 (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) and 56 additional (123)I-meta-iodobenzylguanidine ((123)I-mIBG) single-photon emission computed tomography-CT (SPECT-CT) scans, respectively, of subjects participating in previously executed trials were retrospectively included. BAT activity was measured in subjects after an overnight fast, following 2 h of cold exposure (∼17°C). The average daytime outdoor temperatures and other weather characteristics were obtained from the Dutch Royal Weather Institute. Forty-nine subjects were BAT positive. One week prior to the scan, outdoor temperature was significantly lower in the BAT-positive group compared with the BAT-negative group. Higher outdoor temperatures on preceding days resulted in lower stimulated metabolic BAT activity and volume (all P < 0.01). Outdoor temperatures did not correlate with sympathetic outflow to BAT. In conclusion, outdoor temperatures influence metabolic BAT activity and volume, but not sympathetic outflow to BAT, in subjects exposed to acute cold. To improve the consistency of the findings of future BAT studies in humans and to exclude bias introduced by outdoor temperatures, these studies should be planned in periods of similar outdoor temperatures. Copyright © 2016 the American Physiological Society.

GATE Monte Carlo simulation of GE Discovery 600 and a uniformity phantom

NASA Astrophysics Data System (ADS)

Sheen, Heesoon; Im, Ki Chun; Choi, Yong; Shin, Hanback; Han, Youngyih; Chung, Kwangzoo; Cho, Junsang; Ahn, Sang Hee

2014-12-01

GATE (Geant4 Application Tomography Emission) Monte Carlo simulations have been successful in the application of emission tomography for precise modeling of various physical processes. Most previous studies on Monte Carlo simulations have only involved performance assessments using virtual phantoms. Although that allows the performance of simulated positron emission tomography (PET) to be evaluated, it does not reflect the reality of practical conditions. This restriction causes substantial drawbacks in GATE simulations of real situations. To overcome the described limitation and to provide a method to enable simulation research relevant to clinically important issues, we conducted a GATE simulation using real data from a scanner rather than a virtual phantom and evaluated the scanner is performance. For that purpose, the system and the geometry of a commercial GE PET/ CT (computed tomography) scanner, BGO-based Discovery 600 (D600), was developed for the first time. The performance of the modeled PET system was evaluated by using the National Electrical Manufacturers Association NEMA NU 2-2007 protocols and results were compared with those of the reference data. The sensitivity, scatter fraction, noise-equivalent count rate (NECR), and resolution were estimated by using the protocol of the NEMA NU2-2007. Sensitivities were 9.01 cps/kBq at 0 cm and 9.43 cps/kBq at 10 cm. Scatter fractions were 39.5%. The NECR peak was 89.7 kcps @ 14.7 kBq/cc. Resolutions were 4.8 mm in the transaxial plane and 5.9 mm in the axial plane at 1 cm, and 6.2 mm in the transaxial plane and 6.4 mm in the axial plane at 10 cm. The resolutions exceeded the limited value provided by the manufacturer. The uniformity phantom was simulated using the CT and the PET data. The output data in a ROOT format were converted and then reconstructed by using the C program and STIR (Software for Tomographic Image Reconstruction). The reconstructed images of the simulated uniformity phantom data had comparable quality even though improvement in the quality is still required. In conclusion, we have demonstrated a successful simulation of a PET system by using scanned data. In future studies, the parameters that alter the imaging conditions, such as patient movement and physiological change, need to be studied.

The Effect of Glycolytic Modulation on Prostate Cancer

DTIC Science & Technology

2010-07-01

this paradigm in the clinic, we completed a phase I study of 2-deoxyglucose (2DG), and assessed 2DG uptake with fluorodeoxyglucose (FDG) positron ...efficacy. In vitro studies with 2DG have demonstrated activity in osteosarcoma cells that were defective in oxidative phosphorylation implying that cells...diagnostic studies developing positron emission tomography (PET), which uses a trapped glucose analogue, 2-deoxy-D-glucose (2DG), for detec- tion of

Tau and Amyloid Positron Emission Tomography Imaging Predict Driving Performance Among Older Adults with and without Preclinical Alzheimer's Disease.

PubMed

Roe, Catherine M; Babulal, Ganesh M; Mishra, Shruti; Gordon, Brian A; Stout, Sarah H; Ott, Brian R; Carr, David B; Ances, Beau M; Morris, John C; Benzinger, Tammie L S

2018-01-01

Abnormal levels of Alzheimer's disease (AD) biomarkers, measured by positron emission tomography imaging using amyloid-based radiotracers and cerebrospinal fluid, are associated with impaired driving performance in older adults. We examined whether preclinical AD staging, defined using amyloid imaging and tau imaging using the radiotracer T807 (AKA flortaucipir or AV-1451), was associated with receiving a marginal/fail rating on a standardized road test (n = 42). Participants at Stage 2 (positive amyloid and tau scans) of preclinical AD were more likely to receive a marginal/fail rating compared to participants at Stage 0 or 1. Stage 2 preclinical AD may manifest in worse driving performance.

Dosimetric Considerations in Radioimmunotherapy and Systemic Radionuclide Therapies: A Review

PubMed Central

Loke, Kelvin S. H.; Padhy, Ajit K.; Ng, David C. E.; Goh, Anthony S.W.; Divgi, Chaitanya

2011-01-01

Radiopharmaceutical therapy, once touted as the “magic bullet” in radiation oncology, is increasingly being used in the treatment of a variety of malignancies; albeit in later disease stages. With ever-increasing public and medical awareness of radiation effects, radiation dosimetry is becoming more important. Dosimetry allows administration of the maximum tolerated radiation dose to the tumor/organ to be treated but limiting radiation to critical organs. Traditional tumor dosimetry involved acquiring pretherapy planar scans and plasma estimates with a diagnostic dose of intended radiopharmaceuticals. New advancements in single photon emission computed tomography and positron emission tomography systems allow semi-quantitative measurements of radiation dosimetry thus allowing treatments tailored to each individual patient. PMID:22144871

Use of cyclotrons in medicine

NASA Astrophysics Data System (ADS)

Qaim, S. M.

2004-10-01

Cyclotrons are versatile ion-accelerating machines which find many applications in medicine. In this short review their use in hadron therapy is briefly discussed. Proton therapy is gaining significance because of its capability to treat deep-lying tumours. A strong area of application of cyclotrons involves the production of short-lived neutron deficient radiotracers for use in emission tomography, especially positron emission tomography. This fast and quantitative in vivo diagnostic technique is being increasingly used in neurology, cardiology and oncology. Besides routine patient care, considerable interdisciplinary work on development of new positron emitters is under way. A short account of those efforts is given. The use of cyclotrons in the production of radionuclides for internal radiotherapy is also briefly described.

Distributed Microprocessor Automation Network for Synthesizing Radiotracers Used in Positron Emission Tomography [PET

DOE R&D Accomplishments Database

Russell, J. A. G.; Alexoff, D. L.; Wolf, A. P.

1984-09-01

This presentation describes an evolving distributed microprocessor network for automating the routine production synthesis of radiotracers used in Positron Emission Tomography. We first present a brief overview of the PET method for measuring biological function, and then outline the general procedure for producing a radiotracer. The paper identifies several reasons for our automating the syntheses of these compounds. There is a description of the distributed microprocessor network architecture chosen and the rationale for that choice. Finally, we speculate about how this network may be exploited to extend the power of the PET method from the large university or National Laboratory to the biomedical research and clinical community at large. (DT)

GePEToS: A Geant4 Monte Carlo Simulation Package for Positron Emission Tomography

NASA Astrophysics Data System (ADS)

Jan, S.; Collot, J.; Gallin-Martel, M.-L.; Martin, P.; Mayet, F.; Tournefier, E.

2005-02-01

GePEToS is a simulation framework developed over the last few years for assessing the instrumental performance of future positron emission tomography (PET) scanners. It is based on Geant4, written in object-oriented C++ and runs on Linux platforms. The validity of GePEToS has been tested on the well-known Siemens ECAT EXACT HR+ camera. The results of two application examples are presented: the design optimization of a liquid Xe /spl mu/PET camera dedicated to small animal imaging as well as the evaluation of the effect of a strong axial magnetic field on the image resolution of a Concorde P4 /spl mu/PET camera.

New techniques for positron emission tomography in the study of human neurological disorders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuhl, D.E.

1993-01-01

This progress report describes accomplishments of four programs. The four programs are entitled (1) Faster,simpler processing of positron-computing precursors: New physicochemical approaches, (2) Novel solid phase reagents and methods to improve radiosynthesis and isotope production, (3) Quantitative evaluation of the extraction of information from PET images, and (4) Optimization of tracer kinetic methods for radioligand studies in PET.

New techniques for positron emission tomography in the study of human neurological disorders: Progress report, December 15, 1987-June 14, 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuhl, D.E.

1988-02-01

A brief progress report is presented describing the preparation and animal testing of /sup 11/C scopolamine and /sup 18/F fluoride. Additional studies entitled ''Automated Arterial Blood Sampling System for PET,'' Rapid Data Analysis Schemes for Functional Imaging in PET,'' and ''Tracer Kinetic Modeling in PET Measures of Cholinergic Receptors'' are described

The Effect of Delayed Auditory Feedback on Activity in the Temporal Lobe while Speaking: A Positron Emission Tomography Study

ERIC Educational Resources Information Center

Takaso, Hideki; Eisner, Frank; Wise, Richard J. S.; Scott, Sophie K.

2010-01-01

Purpose: Delayed auditory feedback is a technique that can improve fluency in stutterers, while disrupting fluency in many nonstuttering individuals. The aim of this study was to determine the neural basis for the detection of and compensation for such a delay, and the effects of increases in the delay duration. Method: Positron emission…

Systematic review with meta-analysis: neuroimaging in hepatitis C chronic infection.

PubMed

Oriolo, G; Egmond, E; Mariño, Z; Cavero, M; Navines, R; Zamarrenho, L; Solà, R; Pujol, J; Bargallo, N; Forns, X; Martin-Santos, R

2018-05-01

Chronic hepatitis C is considered a systemic disease because of extra-hepatic manifestations. Neuroimaging has been employed in hepatitis C virus-infected patients to find in vivo evidence of central nervous system alterations. Systematic review and meta-analysis of neuroimaging research in chronic hepatitis C treatment naive patients, or patients previously treated without sustained viral response, to study structural and functional brain impact of hepatitis C. Using PRISMA guidelines a database search was conducted from inception up until 1 May 2017 for peer-reviewed studies on structural or functional neuroimaging assessment of chronic hepatitis C patients without cirrhosis or encephalopathy, with control group. Meta-analyses were performed when possible. The final sample comprised 25 studies (magnetic resonance spectroscopy [N = 12], perfusion weighted imaging [N = 1], positron emission tomography [N = 3], single-photon emission computed tomography [N = 4], functional connectivity in resting state [N = 1], diffusion tensor imaging [N = 2] and structural magnetic resonance imaging [N = 2]). The whole sample was of 509 chronic hepatitis C patients, with an average age of 41.5 years old and mild liver disease. A meta-analysis of magnetic resonance spectroscopy studies showed increased levels of choline/creatine ratio (mean difference [MD] 0.12, 95% confidence interval [CI] 0.06-0.18), creatine (MD 0.85, 95% CI 0.42-1.27) and glutamate plus glutamine (MD 1.67, 95% CI 0.39-2.96) in basal ganglia and increased levels of choline/creatine ratio in centrum semiovale white matter (MD 0.13, 95% CI 0.07-0.19) in chronic hepatitis C patients compared with healthy controls. Photon emission tomography studies meta-analyses did not find significant differences in PK11195 binding potential in cortical and subcortical regions of chronic hepatitis C patients compared with controls. Correlations were observed between various neuroimaging alterations and neurocognitive impairment, fatigue and depressive symptoms in some studies. Patients with chronic hepatitis C exhibit cerebral metabolite alterations and structural or functional neuroimaging abnormalities, which sustain the hypothesis of hepatitis C virus involvement in brain disturbances. © 2018 John Wiley & Sons Ltd.

Interdisciplinary Study of Egyptian Mummies from the Pushkin State Museum of Fine Arts Collection at the National Research Centre ``Kurchatov Institute''

NASA Astrophysics Data System (ADS)

Yatsishina, E. B.; Kovalchuk, M. V.; Loshak, M. D.; Vasilyev, S. V.; Vasilieva, O. A.; Dyuzheva, O. P.; Pojidaev, V. M.; Ushakov, V. L.

2018-05-01

Nine ancient Egyptian mummies (dated preliminarily to the period from the 1st mill. BCE to the first centuries CE) from the collection of the State Pushkin Museum of Fine Arts have been studied at the National Research Centre "Kurchatov Institute" (NRC KI) on the base of the complex of NBICS technologies. Tomographic scanning is performed using a magneto-resonance tomograph (3 T) and a hybrid positron emission tomography/computed tomography (PET-CT) scanner. Three-dimensional reconstructions of mummies and their anthropological measurements are carried out. Some medical conclusions are drawn based on the tomographic data. In addition, the embalming composition and tissue of one of the mummies are preliminarily analyzed.

Imaging Neurotensin Receptor in Prostate Cancer With 64Cu-Labeled Neurotensin Analogs.

PubMed

Deng, Huaifu; Wang, Hui; Zhang, He; Wang, Mengzhe; Giglio, Ben; Ma, Xiaofen; Jiang, Guihua; Yuan, Hong; Wu, Zhanhong; Li, Zibo

2017-01-01

Neurotensin receptor 1 (NTR-1) is expressed and activated in prostate cancer cells. In this study, we explore the NTR expression in normal mouse tissues and study the positron emission tomography (PET) imaging of NTR in prostate cancer models. Three 64 Cu chelators (1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid [DOTA], 1,4,7-triazacyclononane-N,N',N″-triacetic acid [NOTA], or AmBaSar) were conjugated to an NT analog. Neurotensin receptor binding affinity was evaluated using cell binding assay. The imaging profile of radiolabeled probes was compared in well-established NTR + HT-29 tumor model. Stability of the probes was tested. The selected agents were further evaluated in human prostate cancer PC3 xenografts. All 3 NT conjugates retained the majority of NTR binding affinity. In HT-29 tumor, all agents demonstrated prominent tumor uptake. Although comparable stability was observed, 64 Cu-NOTA-NT and 64 Cu-AmBaSar-NT demonstrated improved tumor to background contrast compared with 64 Cu-DOTA-NT. Positron emission tomography/computed tomography imaging of the NTR expression in PC-3 xenografts showed high tumor uptake of the probes, correlating with the in vitro Western blot results. Blocking experiments further confirmed receptor specificity. Our results demonstrated that 64 Cu-labeled neurotensin analogs are promising imaging agents for NTR-positive tumors. These agents may help us identify NTR-positive lesions and predict which patients and individual tumors are likely to respond to novel interventions targeting NTR-1.

Hypoxic volume evaluated by 18F-fluoromisonidazole positron emission tomography (FMISO-PET) may be a prognostic factor in patients with oral squamous cell carcinoma: preliminary analyses.

PubMed

Sato, J; Kitagawa, Y; Watanabe, S; Asaka, T; Ohga, N; Hirata, K; Shiga, T; Satoh, A; Tamaki, N

2018-05-01

Tumour hypoxia can be detected by 18 F-fluoromisonidazole positron emission tomography (FMISO-PET). Few studies have assessed the relationships of new PET parameters, including hypoxic volume (HV), metabolic tumour volume (MTV), and total lesion glycolysis (TLG), with 5-year survival of patients treated surgically for oral squamous cell carcinoma (OSCC). This study evaluated the relationships between these PET parameters and 5-year survival in OSCC patients. Twenty-three patients (age 42-84 years; 15 male, eight female) with OSCC underwent FMISO- and 18 F-fluoro-2-deoxyglucose (FDG)-PET computed tomography before surgery. All of them underwent radical surgery and were followed up for more than 5 years. The FDG-PET maximum standardized uptake value (SUV max ), HV, MTV, and TLG were measured. The ability of PET parameters to predict disease-free survival (DFS) and loco-regional recurrence (LR) was evaluated using receiver operating characteristic curve analysis. During the follow-up period, five of the 23 patients (22%) died and six (26%) experienced LR. Although FDG-PET SUV max was not significantly associated with DFS or LR, HV correlated significantly with both DFS and LR. TLG, but not MTV, was significantly associated with DFS; however neither MTV nor TLG was related significantly to LR. In conclusion, tumour HV may predict outcomes in patients with OSCC. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Functional Magnetic Resonance Imaging and Spectroscopic Imaging of the Brain: Application of fMRI and fMRS to Reading Disabilities and Education.

ERIC Educational Resources Information Center

Richards, Todd L.

2001-01-01

This tutorial/review covers functional brain-imaging methods and results used to study language and reading disabilities. Although the emphasis is on magnetic resonance imaging and functional magnetic resonance spectroscopy, other imaging techniques are also discussed including positron emission tomography, electroencephalography,…

'What' and 'where' in the human brain.

PubMed

Ungerleider, L G; Haxby, J V

1994-04-01

Multiple visual areas in the cortex of nonhuman primates are organized into two hierarchically organized and functionally specialized processing pathways, a 'ventral stream' for object vision and a 'dorsal stream' for spatial vision. Recent findings from positron emission tomography activation studies have localized these pathways within the human brain, yielding insights into cortical hierarchies, specialization of function, and attentional mechanisms.

Iofetamine hydrochloride I 123: a new radiopharmaceutical for cerebral perfusion imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Druckenbrod, R.W.; Williams, C.C.; Gelfand, M.J.

1989-01-01

Iofetamine hydrochloride I-123 permits cerebral blood perfusion imaging with single photon emission computed tomography (SPECT). SPECT is more widely available than positron emission tomography, and complements anatomic visualization with X-ray computed tomography (CT) or magnetic resonance imaging. Iofetamine is an amphetamine analog that is rapidly taken up by the lungs, then redistributed principally to the liver and brain. The precise mechanism of localization has not been determined, but is believed to result from nonspecific receptor binding. Brain uptake peaks at 30 minutes postinjection and remains relatively constant through 60 minutes. The drug is metabolized and excreted in the urine, withmore » negligible activity remaining at 48 hours. When compared with CT in stroke patients, visualization may be performed sooner after symptom onset and a larger zone of involvement may be evident with iofetamine. Localization of seizure foci and diagnosis of Alzheimer's disease may also be possible. As CT has revolutionized noninvasive imaging of brain anatomy, SPECT with iofetamine permits routine cerebral blood flow imaging. 36 references.« less

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.

2-[18 F]fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) findings of chronic expanding intrapericardial hematoma: a potential interpretive pitfall that mimics a malignant tumor

PubMed Central

2013-01-01

A 77-year-old man who had undergone mitral valve replacement 5 years previously presented with an intrapericardial mass. Computed tomography and magnetic resonance imaging showed that the mass lesion contained hematoma components. Positron-emission tomography (PET) with 2-[18 F] fluoro-2-deoxy-d-glucose (FDG) revealed uptake in the peripheral rim of the mass. These findings suggested the presence of hematoma associated with a malignant lesion. Surgical resection was performed, and the histological diagnosis was chronic expanding intrapericardial hematoma without neoplastic changes. Chronic expanding intrapericardial hematoma is a rare disease but should be considered when an expanding mass is found in a patient after cardiac surgery. The FDG-PET findings of chronic expanding hematomas, including FDG uptake in the peripheral rim of the mass as a result of inflammation, should be recognized as a potential interpretive pitfall that mimics a malignant tumor. PMID:23324446

Usefulness of positron emission tomography in primary intestinal follicular lymphoma

PubMed Central

Tari, Akira; Asaoku, Hideki; Kunihiro, Masaki; Tanaka, Shinji; Yoshino, Tadashi

2013-01-01

Double-balloon enteroscopy (DBE) and video capsule endoscopy are useful for the diagnosis of lymphoma in the small intestine. However, DBE cannot be safely performed in cases with passage disturbance due to wall thickening and stenosis. Additionally, video capsule endoscopy cannot be performed in such cases because of the risk of retention. Here, we report 4 cases of primary follicular lymphoma of the gastrointestinal tract that could be detected using 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (PET-CT). The endoscopic findings of these 4 cases included lesions with wall thickening, which comprised macroscopically clusters of nodules, dense clusters of whitish granules or small nodules, fold thickening and ulcers with irregular margins that occupied the whole lumen with edematous mucosa. All patients fulfilled the World Health Organization grade 1 criteria. 18F-fluorodeoxyglucose PET-CT can help predict the risks that may result from certain endoscopic examinations, such as DBE and video capsule endoscopy. PMID:23569346

Emerging MRI and metabolic neuroimaging techniques in mild traumatic brain injury.

PubMed

Lu, Liyan; Wei, Xiaoer; Li, Minghua; Li, Yuehua; Li, Wenbin

2014-01-01

Traumatic brain injury (TBI) is one of the leading causes of death worldwide, and mild traumatic brain injury (mTBI) is the most common traumatic injury. It is difficult to detect mTBI using a routine neuroimaging. Advanced techniques with greater sensitivity and specificity for the diagnosis and treatment of mTBI are required. The aim of this review is to offer an overview of various emerging neuroimaging methodologies that can solve the clinical health problems associated with mTBI. Important findings and improvements in neuroimaging that hold value for better detection, characterization and monitoring of objective brain injuries in patients with mTBI are presented. Conventional computed tomography (CT) and magnetic resonance imaging (MRI) are not very efficient for visualizing mTBI. Moreover, techniques such as diffusion tensor imaging, magnetization transfer imaging, susceptibility-weighted imaging, functional MRI, single photon emission computed tomography, positron emission tomography and magnetic resonance spectroscopy imaging were found to be useful for mTBI imaging.

Radioactive Nanomaterials for Multimodality Imaging

PubMed Central

Chen, Daiqin; Dougherty, Casey A.; Yang, Dongzhi; Wu, Hongwei; Hong, Hao

2016-01-01

Nuclear imaging techniques, including primarily positron emission tomography (PET) and single-photon emission computed tomography (SPECT), can provide quantitative information for a biological event in vivo with ultra-high sensitivity, however, the comparatively low spatial resolution is their major limitation in clinical application. By convergence of nuclear imaging with other imaging modalities like computed tomography (CT), magnetic resonance imaging (MRI) and optical imaging, the hybrid imaging platforms can overcome the limitations from each individual imaging technique. Possessing versatile chemical linking ability and good cargo-loading capacity, radioactive nanomaterials can serve as ideal imaging contrast agents. In this review, we provide a brief overview about current state-of-the-art applications of radioactive nanomaterials in the circumstances of multimodality imaging. We present strategies for incorporation of radioisotope(s) into nanomaterials along with applications of radioactive nanomaterials in multimodal imaging. Advantages and limitations of radioactive nanomaterials for multimodal imaging applications are discussed. Finally, a future perspective of possible radioactive nanomaterial utilization is presented for improving diagnosis and patient management in a variety of diseases. PMID:27227167

History and future technical innovation in positron emission tomography

PubMed Central

Jones, Terry; Townsend, David

2017-01-01

Abstract. 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. PMID:28401173

Molecular imaging of inflammation and intraplaque vasa vasorum: A step forward to identification of vulnerable plaques?

PubMed Central

ten Kate, Gerrit L.; Sijbrands, Eric J. G.; Valkema, Roelf; ten Cate, Folkert J.; Feinstein, Steven B.; van der Steen, Antonius F. W.; Daemen, Mat J. A. P.

2010-01-01

Current developments in cardiovascular biology and imaging enable the noninvasive molecular evaluation of atherosclerotic vascular disease. Intraplaque neovascularization sprouting from the adventitial vasa vasorum has been identified as an independent predictor of intraplaque hemorrhage and plaque rupture. These intraplaque vasa vasorum result from angiogenesis, most likely under influence of hypoxic and inflammatory stimuli. Several molecular imaging techniques are currently available. Most experience has been obtained with molecular imaging using positron emission tomography and single photon emission computed tomography. Recently, the development of targeted contrast agents has allowed molecular imaging with magnetic resonance imaging, ultrasound and computed tomography. The present review discusses the use of these molecular imaging techniques to identify inflammation and intraplaque vasa vasorum to identify vulnerable atherosclerotic plaques at risk of rupture and thrombosis. The available literature on molecular imaging techniques and molecular targets associated with inflammation and angiogenesis is discussed, and the clinical applications of molecular cardiovascular imaging and the use of molecular techniques for local drug delivery are addressed. PMID:20552308

Use of positron emission tomography (PET) for the diagnosis of large-vessel vasculitis.

PubMed

Loricera, J; Blanco, R; Hernández, J L; Martínez-Rodríguez, I; Carril, J M; Lavado, C; Jiménez, M; González-Vela, C; González-Gay, M Á

2015-01-01

The term vasculitis encompasses a heterogeneous group of diseases that share the presence of inflammatory infiltrates in the vascular wall. The diagnosis of large-vessel vasculitis is often a challenge because the presenting clinical features are nonspecific in many cases and they are often shared by different types of autoimmune and inflammatory diseases including other systemic vasculitides. Moreover, the pathogenesis of large-vessel vasculitis is not fully understood. Nevertheless, the advent of new imaging techniques has constituted a major breakthrough to establish an early diagnosis and a promising tool to monitor the follow-up of patients with largevessel vasculitis. This is the case of the molecular imaging with the combination of positron emission tomography with computed tomography (PET/CT) using different radiotracers, especially the (18)F-fluordeoxyglucose ((18)F-FDG). In this review we have focused on the contribution of (18)F-FDG PET in the diagnosis of large-vessel vasculitis. Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

Breast Cancer Treatment in the Era of Molecular Imaging

PubMed Central

Edelhauser, Gundula; Funovics, Martin

2008-01-01

Summary Molecular imaging employs molecularly targeted probes to visualize and often quantify distinct disease-specific markers and pathways. Modalities like intravital confocal or multiphoton microscopy, near-infrared fluorescence combined with endoscopy, surface reflectance imaging, or fluorescence-mediated tomography, and radionuclide imaging with positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are increasingly used for small animal high-throughput screening, drug development and testing, and monitoring gene therapy experiments. In the clinical treatment of breast cancer, PET and SPECT as well as magnetic resonance-based molecular imaging are already established for the staging of distant disease and intrathoracic nodal status, for patient selection regarding receptor-directed treatments, and to gain early information about treatment efficacy. In the near future, reporter gene imaging during gene therapy and further spatial and qualitative characterization of the disease can become clinically possible with radionuclide and optical methods. Ultimately, it may be expected that every level of breast cancer treatment will be affected by molecular imaging, including screening. PMID:21048912

Image Fusion During Vascular and Nonvascular Image-Guided Procedures☆

PubMed Central

Abi-Jaoudeh, Nadine; Kobeiter, Hicham; Xu, Sheng; Wood, Bradford J.

2013-01-01

Image fusion may be useful in any procedure where previous imaging such as positron emission tomography, magnetic resonance imaging, or contrast-enhanced computed tomography (CT) defines information that is referenced to the procedural imaging, to the needle or catheter, or to an ultrasound transducer. Fusion of prior and intraoperative imaging provides real-time feedback on tumor location or margin, metabolic activity, device location, or vessel location. Multimodality image fusion in interventional radiology was initially introduced for biopsies and ablations, especially for lesions only seen on arterial phase CT, magnetic resonance imaging, or positron emission tomography/CT but has more recently been applied to other vascular and nonvascular procedures. Two different types of platforms are commonly used for image fusion and navigation: (1) electromagnetic tracking and (2) cone-beam CT. Both technologies would be reviewed as well as their strengths and weaknesses, indications, when to use one vs the other, tips and guidance to streamline use, and early evidence defining clinical benefits of these rapidly evolving, commercially available and emerging techniques. PMID:23993079

Imaging atherosclerosis with hybrid [18F]fluorodeoxyglucose positron emission tomography/computed tomography imaging: what Leonardo da Vinci could not see.

PubMed

Cocker, Myra S; Mc Ardle, Brian; Spence, J David; Lum, Cheemun; Hammond, Robert R; Ongaro, Deidre C; McDonald, Matthew A; Dekemp, Robert A; Tardif, Jean-Claude; Beanlands, Rob S B

2012-12-01

Prodigious efforts and landmark discoveries have led toward significant advances in our understanding of atherosclerosis. Despite significant efforts, atherosclerosis continues globally to be a leading cause of mortality and reduced quality of life. With surges in the prevalence of obesity and diabetes, atherosclerosis is expected to have an even more pronounced impact upon the global burden of disease. It is imperative to develop strategies for the early detection of disease. Positron emission tomography (PET) imaging utilizing [(18)F]fluorodeoxyglucose (FDG) may provide a non-invasive means of characterizing inflammatory activity within atherosclerotic plaque, thus serving as a surrogate biomarker for detecting vulnerable plaque. The aim of this review is to explore the rationale for performing FDG imaging, provide an overview into the mechanism of action, and summarize findings from the early application of FDG PET imaging in the clinical setting to evaluate vascular disease. Alternative imaging biomarkers and approaches are briefly discussed.

Clinical determinants of fluorodeoxyglucose positron emission tomography/computed tomography in differentiated thyroid cancer patients with elevated thyroglobulin and negative (131)iodine whole body scans after (131)iodine therapy.

PubMed

Shamim, Syed Ejaz; Nang, Lee Boon; Shuaib, Ibrahim Lutfi; Muhamad, Nor Asiah

2014-05-01

A cross-sectional prospective study has been conducted on differentiated thyroid cancer (DTC) patients using negative (131)Iodine ((131)I) whole body scans and elevated thyroglobulin (Tg) levels. The main objective of this research was to determine the prevalence of the conversion of differentiated to dedifferentiated thyroid cancer patients during follow up at the Hospital Kuala Lumpur. It has been demonstrated that fluorodeoxyglucose (FDG) uptake is inversely proportional to the iodine concentration and to differentiation of the cells. Thirty-five patients with histologically proven DTC that have undergone total or near total thyroidectomy, and post (131)I radioactive iodine ablation therapy, were selected and prospectively analysed. The patients also had to show at least one negative whole body scan and Tg levels of 10 μg/L and above. The results of the FDG-Positron Emission Tomography/Computed Tomography (PET/CT) were then studied to determine the association and the predictors influencing the outcome by using univariable and multivariable analyses. Out of the thirty-five patients, 60% of them (twenty-one) showed positive results and 40% (fourteen) showed negative. Age, gender, and type of histopathology (HPE) showed significant associations with the positive results of the FDG-PET/CT. The results also showed no correlations observed between the Tg levels and standardised uptake value (SUV)max in the DTC patients with positive disease findings in the FDG-PET/CT. The predictor for this study was age. The prevalence of the conversion of differentiated to dedifferentiated thyroid cancer among patients with negative (131)I and elevated Tg was 60%, with age as the predictor. DTC patients aged 45 year-old and older were seven times more likely to have positive results of FDG-PET/CT imaging.

[18F]-Fluoromisonidazole Positron Emission Tomography/Computed Tomography Visualization of Tumor Hypoxia in Patients With Chordoma of the Mobile and Sacrococcygeal Spine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheney, Matthew D., E-mail: mcheney@lroc.harvard.edu; Chen, Yen-Lin; Lim, Ruth

2014-12-01

Purpose: To investigate [18F]-fluoromisonidazole positron emission tomography/computed tomography (FMISO-PET/CT) detection of targetable hypoxic subvolumes (HSVs) in chordoma of the mobile or sacrococcygeal spine. Methods and Materials: A prospective, pilot study of 20 patients with primary or locally recurrent chordoma of the mobile or sacrococcygeal spine treated with proton or combined proton/photon radiation therapy (RT) with or without surgery was completed. The FMISO-PET/CT was performed before RT and after 19.8-34.2 GyRBE (relative biologic effectiveness). Gross tumor volumes were delineated and HSVs defined including voxels with standardized uptake values ≥1.4 times the muscle mean. Clinical characteristics and treatments received were compared betweenmore » patients with and without HSVs. Results: The FMISO-PET/CT detected HSVs in 12 of 20 patients (60%). Baseline and interval HSV spatial concordance varied (0%-94%). Eight HSVs were sufficiently large (≥5 cm{sup 3}) to potentially allow an intensity modulated proton therapy boost. Patients with HSVs had significantly larger gross tumor volumes (median 410.0 cm{sup 3} vs 63.4 cm{sup 3}; P=.02) and were significantly more likely to have stage T2 tumors (5 of 12 vs 0 of 8; P=.04). After a median follow-up of 1.8 years (range, 0.2-4.4 years), a local recurrence has yet to be observed. Three patients developed metastatic disease, 2 with HSVs. Conclusions: Detection of targetable HSVs by FMISO-PET/CT within patients undergoing RT with or without surgery for treatment of chordoma of the mobile and sacrococcygeal spine is feasible. The study's inability to attribute interval HSV changes to treatment, rapidly changing hypoxic physiology, or imaging inconsistencies is a limitation. Further study of double-baseline FMISO-PET/CT and hypoxia-directed RT dose escalation, particularly in patients at high risk for local recurrence, is warranted.« less

Diagnostic Accuracy of 64Copper Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography for Primary Lymph Node Staging of Intermediate- to High-risk Prostate Cancer: Our Preliminary Experience.

PubMed

Cantiello, Francesco; Gangemi, Vincenzo; Cascini, Giuseppe Lucio; Calabria, Ferdinando; Moschini, Marco; Ferro, Matteo; Musi, Gennaro; Butticè, Salvatore; Salonia, Andrea; Briganti, Alberto; Damiano, Rocco

2017-08-01

To assess the diagnostic accuracy of 64 Copper prostate-specific membrane antigen ( 64 Cu-PSMA) positron emission tomography/computed tomography (PET/CT) in the primary lymph node (LN) staging of a selected cohort of intermediate- to high-risk prostate cancer (PCa) patients. An observational prospective study was performed in 23 patients with intermediate- to high-risk PCa, who underwent 64 Cu-PSMA PET/CT for local and lymph nodal staging before laparoscopic radical prostatectomy with an extended pelvic LN dissection. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for LN status of 64 Cu-PSMA PET/CT were calculated using the final pathological findings as reference. Furthermore, we evaluated the correlation of intraprostatic tumor extent and grading with 64 Cu-PSMA intraprostatic distribution. Pathological analysis of LN involvement in 413 LNs harvested from our study cohort identified a total of 22 LN metastases in 8 (5%) of the 23 (35%) PCa patients. Imaging-based LN staging in a per-patient analysis showed that 64 Cu-PSMA PET/CT was positive in 7 of 8 LN-positive patients (22%) with a sensitivity of 87.5%, specificity of 100%, PPV of 100%, and NPV of 93.7%, considering the maximum standardized uptake value (SUV max ) at 4 hours as our reference. Receiver operating characteristic curve was characterized by an area under the curve of 0.938. A significant positive association was observed between SUV max at 4 hours with Gleason score, index, and cumulative tumor volume. In our intermediate- to high-risk PCa patients study cohort, we showed the high diagnostic accuracy of 64 Cu-PSMA PET/CT for primary LN staging before radical prostatectomy. Copyright © 2017 Elsevier Inc. All rights reserved.

Positron Emission Tomography/Computed Tomography Identification of Clear Cell Renal Cell Carcinoma: Results From the REDECT Trial

PubMed Central

Divgi, Chaitanya R.; Uzzo, Robert G.; Gatsonis, Constantine; Bartz, Roman; Treutner, Silke; Yu, Jian Qin; Chen, David; Carrasquillo, Jorge A.; Larson, Steven; Bevan, Paul; Russo, Paul

2013-01-01

Purpose A clinical study to characterize renal masses with positron emission tomography/computed tomography (PET/CT) was undertaken. Patients and Methods This was an open-label multicenter study of iodine-124 (124I) -girentuximab PET/CT in patients with renal masses who were scheduled for resection. PET/CT and contrast-enhanced CT (CECT) of the abdomen were performed 2 to 6 days after intravenous 124I-girentuximab administration and before resection of the renal mass(es). Images were interpreted centrally by three blinded readers for each imaging modality. Tumor histology was determined by a blinded central pathologist. The primary end points—average sensitivity and specificity for clear cell renal cell carcinoma (ccRCC)—were compared between the two modalities. Agreement between and within readers was assessed. Results 124I-girentuximab was well tolerated. In all, 195 patients had complete data sets (histopathologic diagnosis and PET/CT and CECT results) available. The average sensitivity was 86.2% (95% CI, 75.3% to 97.1%) for PET/CT and 75.5% (95% CI, 62.6% to 88.4%) for CECT (P = .023). The average specificity was 85.9% (95% CI, 69.4% to 99.9%) for PET/CT and 46.8% (95% CI, 18.8% to 74.7%) for CECT (P = .005). Inter-reader agreement was high (κ range, 0.87 to 0.92 for PET/CT; 0.67 to 0.76 for CECT), as was intrareader agreement (range, 87% to 100% for PET/CT; 73.7% to 91.3% for CECT). Conclusion This study represents (to the best of our knowledge) the first clinical validation of a molecular imaging biomarker for malignancy. 124I-girentuximab PET/CT can accurately and noninvasively identify ccRCC, with potential utility for designing best management approaches for patients with renal masses. PMID:23213092

Bone and Gallium Single-Photon Emission Computed Tomography-Computed Tomography is Equivalent to Magnetic Resonance Imaging in the Diagnosis of Infectious Spondylodiscitis: A Retrospective Study.

PubMed

Tamm, Alexander S; Abele, Jonathan T

2017-02-01

Spondylodiscitis has historically been a difficult clinical diagnosis. Two imaging techniques that address this problem are magnetic resonance imaging (MRI) and combined bone ( 99m Tc-methylene diphosphonate) and gallium-67 single-photon emission computed tomography-computed tomography (SPECT-CT). Their accuracies have not been adequately compared. The purpose of this study is to compare the sensitivities and specificities of bone and gallium SPECT-CT and MRI in infectious spondylodiscitis. This retrospective study assessed all patients who underwent a bone or gallium SPECT-CT of the spine to assess for infectious spondylodiscitis from January 1, 2010, to May 2, 2012, at a single tertiary care centre. Thirty-four patients (23 men; average 62 ± 14 years of age) were included. The results of the bone or gallium SPECT-CT were compared against MRI for all patients in the cohort who underwent an MRI within 12 weeks of the SPECT-CT. A diagnosis of spondylodiscitis in the discharge summary was considered the reference standard, and was based on a combination of clinical scenario, response to therapy, imaging, or microbiology. Spondylodiscitis was diagnosed in 18 patients and excluded in 16. Bone or gallium SPECT-CT and MRI had similar (P > .05; κ = 0.74) sensitivities (0.94 vs 0.94), specificities (1.00 vs 1.00), positive predictive values (1.00 vs 1.00), negative predictive values (0.94 vs 0.80), and accuracies (0.97 vs 0.95) when compared to the reference standard. Although MRI remains the initial modality of choice in diagnosing spondylodiscitis, bone and gallium SPECT-CT appears diagnostically equivalent and should be considered a viable supplementary or alternative imaging modality particularly if there is contraindication or inaccessibility to MRI. Copyright © 2016 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

Clinical Determinants of Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Differentiated Thyroid Cancer Patients with Elevated Thyroglobulin and Negative 131Iodine Whole Body Scans after 131Iodine Therapy

PubMed Central

SHAMIM, Syed Ejaz; NANG, Lee Boon; SHUAIB, Ibrahim Lutfi; MUHAMAD, Nor Asiah

2014-01-01

Background: A cross-sectional prospective study has been conducted on differentiated thyroid cancer (DTC) patients using negative 131Iodine (131I) whole body scans and elevated thyroglobulin (Tg) levels. The main objective of this research was to determine the prevalence of the conversion of differentiated to dedifferentiated thyroid cancer patients during follow up at the Hospital Kuala Lumpur. It has been demonstrated that fluorodeoxyglucose (FDG) uptake is inversely proportional to the iodine concentration and to differentiation of the cells. Methods: Thirty-five patients with histologically proven DTC that have undergone total or near total thyroidectomy, and post 131I radioactive iodine ablation therapy, were selected and prospectively analysed. The patients also had to show at least one negative whole body scan and Tg levels of 10 μg/L and above. The results of the FDG-Positron Emission Tomography/Computed Tomography (PET/CT) were then studied to determine the association and the predictors influencing the outcome by using univariable and multivariable analyses. Results: Out of the thirty-five patients, 60% of them (twenty-one) showed positive results and 40% (fourteen) showed negative. Age, gender, and type of histopathology (HPE) showed significant associations with the positive results of the FDG-PET/CT. The results also showed no correlations observed between the Tg levels and standardised uptake value (SUV)max in the DTC patients with positive disease findings in the FDG-PET/CT. The predictor for this study was age. Conclusion: The prevalence of the conversion of differentiated to dedifferentiated thyroid cancer among patients with negative 131I and elevated Tg was 60%, with age as the predictor. DTC patients aged 45 year-old and older were seven times more likely to have positive results of FDG-PET/CT imaging. PMID:25246834

Dynamic dual-isotope molecular imaging elucidates principles for optimizing intrathecal drug delivery

PubMed Central

Wolf, Daniel A.; Hesterman, Jacob Y.; Sullivan, Jenna M.; Orcutt, Kelly D.; Silva, Matthew D.; Lobo, Merryl; Wellman, Tyler; Hoppin, Jack

2016-01-01

The intrathecal (IT) dosing route offers a seemingly obvious solution for delivering drugs directly to the central nervous system. However, gaps in understanding drug molecule behavior within the anatomically and kinetically unique environment of the mammalian IT space have impeded the establishment of pharmacokinetic principles for optimizing regional drug exposure along the neuraxis. Here, we have utilized high-resolution single-photon emission tomography with X-ray computed tomography to study the behavior of multiple molecular imaging tracers following an IT bolus injection, with supporting histology, autoradiography, block-face tomography, and MRI. Using simultaneous dual-isotope imaging, we demonstrate that the regional CNS tissue exposure of molecules with varying chemical properties is affected by IT space anatomy, cerebrospinal fluid (CSF) dynamics, CSF clearance routes, and the location and volume of the injected bolus. These imaging approaches can be used across species to optimize the safety and efficacy of IT drug therapy for neurological disorders. PMID:27699254

Fluorodeoxyglucose positron emission tomography–computed tomography in evaluation of pelvic and para-aortic nodal involvement in early stage and operable cervical cancer: Comparison with surgicopathological findings

PubMed Central

Bansal, Vandana; Damania, Kaizad; Sharma, Anshu Rajnish

2011-01-01

Introduction: Nodal metastases in cervical cancer have prognostic implications. Imaging is used as an adjunct to clinical staging for evaluation of nodal metastases. Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has an advantage of superior resolution of its CT component and detecting nodal disease based on increased glycolytic activity rather than node size. But there are limited studies describing its limitations in early stage cervical cancers. Objective: We have done meta-analysis with an objective to evaluate the efficacy of FDG PET/CT and its current clinical role in early stage and operable cervical cancer. Materials and Methods: Studies in which FDG PET/CT was performed before surgery in patients with early stage cervical cancers were included for analysis. PET findings were confirmed with histopathological diagnosis rather than clinical follow-up. FDG PET/CT showed lower sensitivity and clinically unacceptable negative predictive value in detecting nodal metastases in early stage cervical cancer and therefore, can not replace surgicopathological staging. False negative results in presence of microscopic disease and sub-centimeter diseased nodes are still the area of concern for metabolic imaging. However, these studies are single institutional and performed in a small group of patients. There is enough available evidence of clinical utility of FDG PET/CT in locally advanced cervical cancer. But these results can not be extrapolated for early stage disease. Conclusion: The current data suggest that FDG PET/CT is suboptimal in nodal staging in early stage cervical cancer. PMID:23559711

Diagnostic performance of Fluorine-18-Fluorodeoxyglucose positron emission tomography for the diagnosis of osteomyelitis related to diabetic foot: a systematic review and a meta-analysis.

PubMed

Treglia, Giorgio; Sadeghi, Ramin; Annunziata, Salvatore; Zakavi, Seyed Rasoul; Caldarella, Carmelo; Muoio, Barbara; Bertagna, Francesco; Ceriani, Luca; Giovanella, Luca

2013-12-01

To systematically review and meta-analyse published data about the diagnostic performance of Fluorine-18-Fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) and PET/computed tomography (PET/CT) in osteomyelitis related to diabetic foot. A comprehensive literature search of studies on (18)F-FDG-PET and PET/CT in patients with diabetic foot was performed. Pooled sensitivity, specificity, positive and negative likelihood ratio (LR+ and LR-) and diagnostic odds ratio (DOR) and area under the summary ROC curve of (18)F-FDG-PET and PET/CT in patients with osteomyelitis related to diabetic foot were calculated. Nine studies comprising 299 patients with diabetic foot were included in the qualitative analysis (systematic review) and discussed. The quantitative analysis (meta-analysis) of four selected studies provided the following results on a per patient-based analysis: sensitivity was 74% [95% confidence interval (95%CI): 60-85%], specificity 91% (95%CI: 85-96%), LR+ 5.56 (95%CI: 2.02-15.27), LR- 0.37 (95%CI: 0.10-1.35), and DOR 16.96 (95%CI: 2.06-139.66). The area under the summary ROC curve was 0.874. In patients with suspected osteomyelitis related to diabetic foot (18)F-FDG-PET and PET/CT demonstrated a high specificity, being potentially useful tools if combined with other imaging methods such as MRI. Nevertheless, the literature focusing on the use of (18)F-FDG-PET and PET/CT in this setting remains still limited. Copyright © 2013 Elsevier Ltd. All rights reserved.