Coronary artery disease remains a major cause of mortality. Presence of atherosclerotic plaques in the coronary artery is responsible for lu-men stenosis which is often used as an indicator for determining the severity of coronary artery disease. However, the degree of coronary lumen stenosis is not often related to compromising myocardial blood flow, as most of the cardiac events that are caused by atherosclerotic plaques are the result of vulnerable plaques which are prone to rupture. Thus, identification of vulnerable plaques in coronary arteries has become increas-ingly important to assist identify patients with high cardiovascular risks. Molecular imaging with use of positron emission tomography (PET) and single photon emission computed tomography (SPECT) has fulfilled this goal by providing functional information about plaque activity which enables accurate assessment of plaque stability. This review article provides an overview of diagnostic applications of molecular imaging tech-niques in the detection of plaques in coronary arteries with PET and SPECT. New radiopharmaceuticals used in the molecular imaging of coro-nary plaques and diagnostic applications of integrated PET/CT and PET/MRI in coronary plaques are also discussed.

The aim of this report was to assess the changes in the 18F-fluorodeoxyglucose (18F-FDG) uptake of brown fats on integrated positron emission tomography/computed tomography (PET/CT) imaging. The patient presented with an enlargement of the neck lymph nodes, and was suspicious for tuberculous lymphadenitis. A whole body PET/CT imaging was performed, followed by a delayed imaging of the neck and thoracic regions. A visually increased 18F-FDG uptake was taken as a positive finding. A semi-quantitative evaluation was performed using a maximum standardised uptake value (SUVmax), with a cut-off value above 2.5. There were a number of 18F-FDG avid activity areas seen at the supraclavicular, mediastinal, paravertebral and perirenal regions. These are in keeping with the physiological 18F-FDG uptake in brown fat. The differences in SUVmax between the two images ranged from -20 percent to +20 percent. Based on our observations, dual time point imaging may not be a reliable method for assessing the 18F-FDG uptake of brown fat.
Adipose Tissue, Brown ; diagnostic imaging ; metabolism ; Adult ; Female ; Fluorodeoxyglucose F18 ; Humans ; Positron-Emission Tomography ; methods ; Tuberculosis, Lymph Node ; diagnostic imaging

Introduction: This preliminary study aimed to non-invasively evaluate choline (CHO), creatine (Cr) and intramyocellular lipid (IMCL) metabolites in skeletal muscles at pre- and post-functional electrical stimulation (FES) exercise among incomplete spinal cord injury (SCI) of American Spinal Injury Association Impairment Scale (ASIA-AIS) D patients using proton magnetic resonance spectroscopy or 1 H-MRS. Methods: These metabolites were measured from the vastus lateralis and semitendinosus muscles of three incomplete SCI ASIA-AIS D patients who completed the FES exercise and later underwent 3 Tesla (T) MRI (repetition time/echo time; TR/TE of 3500ms/100ms, field-ofview; FOV of 20cm, slice thickness of 6mm) and 1 H-MRS (TR/TE of 2000ms/31ms, voxel size of 20mm x 20mm x 35mm). Results: Out of those selected metabolites, only CHO value of vastus lateralis showed a statistically significant difference between pre- and post FES exercise 1 H-MRS scanning (p = 0.01). Conclusion: Therefore, this preliminary finding has postulated that the quantification of muscle metabolites using 1 H-MRS imaging could be used as a potential indicator in evaluating the muscle strength for incomplete SCI ASIA-AIS D patients after the completion of FES cycling exercise.