scholarly journals Meta-Analysis of Molecular Imaging of Serotonin Transporters in Major Depression

2014 ◽  
Vol 34 (7) ◽  
pp. 1096-1103 ◽  
Author(s):  
Gregor Gryglewski ◽  
Rupert Lanzenberger ◽  
Georg S Kranz ◽  
Paul Cumming
Keyword(s):  
Molecular Imaging ◽  
Temporal Dynamics ◽  
Single Photon ◽  
Meta Analysis ◽  
Photon Emission ◽  
Strong Relationship ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Sufficient Power ◽  
Severity Of Depression

The success of serotonin-selective reuptake inhibitors has lent support to the monoamine theory of major depressive disorder (MDD). This issue has been addressed in a number of molecular imaging studies by positron emission tomography or single-photon emission computed tomography of serotonin reuptake sites (5-HTT) in the brain of patients with MDD, with strikingly disparate conclusions. Our meta-analysis of the 18 such studies, totaling 364 MDD patients free from significant comorbidities or medication and 372 control subjects, revealed reductions in midbrain 5-HTT (Hedges' g = −0.49; 95% CI: (−0.84, −0.14)) and amygdala (Hedges' g = −0.50; 95% CI: (−0.78, −0.22)), which no individual study possessed sufficient power to detect. Only small effect sizes were found in other regions with high binding (thalamus: g = −0.24, striatum: g = −0.32, and brainstem g = −0.22), and no difference in the frontal or cingulate cortex. Age emerged as an important moderator of 5-HTT availability in MDD, with more severe reductions in striatal 5-HTT evident with greater age of the study populations ( P<0.01). There was a strong relationship between severity of depression and 5-HTT reductions in the amygdala ( P = 0.01). Thus, molecular imaging findings indeed reveal widespread reductions of ˜10% in 5-HTT availability in MDD, which may predict altered spatial-temporal dynamics of serotonergic neurotransmission.

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

2017 ◽  
Vol 1 ◽  
pp. 247054701771091 ◽  
Author(s):  
Margaret T. Davis ◽  
Sophie E. Holmes ◽  
Robert H. Pietrzak ◽  
Irina Esterlis
Keyword(s):  
Molecular Imaging ◽  
Chronic Stress ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Single Photon Emission ◽  
Major Depressive ◽  
Positron Emission ◽  
Single Photon Emission Computed ◽  
Photon Emission Computed Tomography

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.

scholarly journals Mitochondrial-Targeted Molecular Imaging in Cardiac Disease

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Jinhui Li ◽  
Jing Lu ◽  
You Zhou
Keyword(s):  
Molecular Imaging ◽  
Cardiac Disease ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Molecular Imaging Probes ◽  
Imaging Probes ◽  
Targeted Molecular Imaging

The present study aimed to discuss the role of mitochondrion in cardiac function and disease. The mitochondrion plays a fundamental role in cellular processes ranging from metabolism to apoptosis. The mitochondrial-targeted molecular imaging could potentially illustrate changes in global and regional cardiac dysfunction. The collective changes that occur in mitochondrial-targeted molecular imaging probes have been widely explored and developed. As probes currently used in the preclinical setting still have a lot of shortcomings, the development of myocardial metabolic activity, viability, perfusion, and blood flow molecular imaging probes holds great potential for accurately evaluating the myocardial viability and functional reserve. The advantages of molecular imaging provide a perspective on investigating the mitochondrial function of the myocardium in vivo noninvasively and quantitatively. The molecular imaging tracers of single-photon emission computed tomography and positron emission tomography could give more detailed information on myocardial metabolism and restoration. In this study, series mitochondrial-targeted99mTc-,123I-, and18F-labeled tracers displayed broad applications because they could provide a direct link between mitochondrial dysfunction and cardiac disease.

scholarly journals Molecular Imaging in Tumor Angiogenesis and Relevant Drug Research

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Xibo Ma ◽  
Jie Tian ◽  
Xin Yang ◽  
Chenghu Qin
Keyword(s):  
Computed Tomography ◽  
Molecular Imaging ◽  
Tumor Angiogenesis ◽  
Drug Research ◽  
Single Photon ◽  
Photon Emission ◽  
Region Of Interest ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Novel Drug

Molecular imaging, including fluorescence imaging (FMI), bioluminescence imaging (BLI), positron emission tomography (PET), single-photon emission-computed tomography (SPECT), and computed tomography (CT), has a pivotal role in the process of tumor and relevant drug research. CT, especially Micro-CT, can provide the anatomic information for a region of interest (ROI); PET and SPECT can provide functional information for the ROI. BLI and FMI can provide optical information for an ROI. Tumor angiogenesis and relevant drug development is a lengthy, high-risk, and costly process, in which a novel drug needs about 10–15 years of testing to obtain Federal Drug Association (FDA) approval. Molecular imaging can enhance the development process by understanding the tumor mechanisms and drug activity. In this paper, we focus on tumor angiogenesis, and we review the characteristics of molecular imaging modalities and their applications in tumor angiogenesis and relevant drug research.

scholarly journals New SPECT and PET Radiopharmaceuticals for Imaging Cardiovascular Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-24 ◽  
Author(s):  
Oyebola O. Sogbein ◽  
Matthieu Pelletier-Galarneau ◽  
Thomas H. Schindler ◽  
Lihui Wei ◽  
R. Glenn Wells ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Prognostic Information ◽  
Spect Myocardial Perfusion ◽  
Positron Emission ◽  
Magnetic Resonance Imaging Mri ◽  
Novel Target ◽  
Photon Emission Computed Tomography

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

Recent Advances in Targeting Nuclear Molecular Imaging Driven by Tetrazine Bioorthogonal Chemistry

2020 ◽  
Vol 27 (23) ◽  
pp. 3924-3943 ◽  
Author(s):  
Ping Dong ◽  
Xueyi Wang ◽  
Junwei Zheng ◽  
Xiaoyang Zhang ◽  
Yiwen Li ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Single Photon ◽  
Imaging Techniques ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Bioorthogonal Chemistry ◽  
Cellular Processes ◽  
Positron Emission ◽  
Diagnosis Of Cancer

Molecular imaging techniques apply sophisticated technologies to monitor, directly or indirectly, the spatiotemporal distribution of molecular or cellular processes for biomedical, diagnostic, or therapeutic purposes. For example, Single-Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) imaging, the most representative modalities of molecular imaging, enable earlier and more accurate diagnosis of cancer and cardiovascular diseases. New possibilities for noninvasive molecular imaging in vivo have emerged with advances in bioorthogonal chemistry. For example, tetrazine-related Inverse Electron Demand Diels-Alder (IEDDA) reactions can rapidly generate short-lived radioisotope probes in vivo that provide strong contrast for SPECT and PET. Here, we review pretargeting strategies for molecular imaging and novel radiotracers synthesized via tetrazine bioorthogonal chemistry. We systematically describe advances in direct radiolabeling and pretargeting approaches in SPECT and PET using metal and nonmetal radioisotopes based on tetrazine bioorthogonal reactions, and we discuss prospects for the future of such contrast agents.

scholarly journals Toward Molecular Imaging of Intestinal Pathology

2020 ◽  
Vol 26 (10) ◽  
pp. 1470-1484 ◽  
Author(s):  
Mariane Le Fur ◽  
Iris Y Zhou ◽  
Onofrio Catalano ◽  
Peter Caravan
Keyword(s):  
Computed Tomography ◽  
Molecular Imaging ◽  
Single Photon ◽  
Imaging Techniques ◽  
Photon Emission ◽  
Major Complication ◽  
Emission Computed Tomography ◽  
Cross Sectional ◽  
Intestinal Fibrosis ◽  
Positron Emission

Abstract Inflammatory bowel disease (IBD) is defined by a chronic relapsing and remitting inflammation of the gastrointestinal tract, with intestinal fibrosis being a major complication. The etiology of IBD remains unknown, but it is thought to arise from a dysregulated and excessive immune response to gut luminal microbes triggered by genetic and environmental factors. To date, IBD has no cure, and treatments are currently directed at relieving symptoms and treating inflammation. The current diagnostic of IBD relies on endoscopy, which is invasive and does not provide information on the presence of extraluminal complications and molecular aspect of the disease. Cross-sectional imaging modalities such as computed tomography enterography (CTE), magnetic resonance enterography (MRE), positron emission tomography (PET), single photon emission computed tomography (SPECT), and hybrid modalities have demonstrated high accuracy for the diagnosis of IBD and can provide both functional and morphological information when combined with the use of molecular imaging probes. This review presents the state-of-the-art imaging techniques and molecular imaging approaches in the field of IBD and points out future directions that could help improve our understanding of IBD pathological processes, along with the development of efficient treatments.

scholarly journals A Nordic survey of CT doses in hybrid PET/CT and SPECT/CT examinations

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Natalie A. Bebbington ◽  
Bryan T. Haddock ◽  
Henrik Bertilsson ◽  
Eero Hippeläinen ◽  
Ellen M. Husby ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Single Photon Emission ◽  
Positron Emission ◽  
Pet Ct ◽  
Clinical Purpose ◽  
Single Photon Emission Computed ◽  
Photon Emission Computed Tomography

Abstract Background Computed tomography (CT) scans are routinely performed in positron emission tomography (PET) and single photon emission computed tomography (SPECT) examinations globally, yet few surveys have been conducted to gather national diagnostic reference level (NDRL) data for CT radiation doses in positron emission tomography/computed tomography (PET/CT) and single photon emission computed tomography/computed tomography (SPECT/CT). In this first Nordic-wide study of CT doses in hybrid imaging, Nordic NDRL CT doses are suggested for PET/CT and SPECT/CT examinations specific to the clinical purpose of CT, and the scope for optimisation is evaluated. Data on hybrid imaging CT exposures and clinical purpose of CT were gathered for 5 PET/CT and 8 SPECT/CT examinations via designed booklet. For each included dataset for a given facility and scanner type, the computed tomography dose index by volume (CTDIvol) and dose length product (DLP) was interpolated for a 75-kg person (referred to as CTDIvol,75kg and DLP75kg). Suggested NDRL (75th percentile) and achievable doses (50th percentile) were determined for CTDIvol,75kg and DLP75kg according to clinical purpose of CT. Differences in maximum and minimum doses (derived for a 75-kg patient) between facilities were also calculated for each examination and clinical purpose. Results Data were processed from 83 scanners from 43 facilities. Data were sufficient to suggest Nordic NDRL CT doses for the following: PET/CT oncology (localisation/characterisation, 15 systems); infection/inflammation (localisation/characterisation, 13 systems); brain (attenuation correction (AC) only, 11 systems); cardiac PET/CT and SPECT/CT (AC only, 30 systems); SPECT/CT lung (localisation/characterisation, 12 systems); bone (localisation/characterisation, 30 systems); and parathyroid (localisation/characterisation, 13 systems). Great variations in dose were seen for all aforementioned examinations. Greatest differences in DLP75kg for each examination, specific to clinical purpose, were as follows: SPECT/CT lung AC only (27.4); PET/CT and SPECT/CT cardiac AC only (19.6); infection/inflammation AC only (18.1); PET/CT brain localisation/characterisation (16.8); SPECT/CT bone localisation/characterisation (10.0); PET/CT oncology AC only (9.0); and SPECT/CT parathyroid localisation/characterisation (7.8). Conclusions Suggested Nordic NDRL CT doses are presented according to clinical purpose of CT for PET/CT oncology, infection/inflammation, brain, PET/CT and SPECT/CT cardiac, and SPECT/CT lung, bone, and parathyroid. The large variation in doses suggests great scope for optimisation in all 8 examinations.

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