Annals of nuclear medicine
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The deep-inspiration breath-hold PET/CT (DIBH PET/CT) technique improves the limitations of diagnosing a lesion located in an area influenced by respiratory motion that results in spatial misregistrations caused by respiration between PET and CT. However, its reproducibility with regard to calculating the maximal standardized uptake value (SUV(max)) and metabolic volume (MV) in DIBH PET/CT has not been elucidated. ⋯ The DIBH technique improves the inaccurate quantification of both SUV(max) and MV. Although the CV value of SUV(max) with DIBH technique is better in thoracic lesions compared with that in abdominal lesions, the reproducibility was acceptable.
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In positron emission tomography/computed tomography (PET/CT) examinations, the standardized uptake value (SUV) is a commonly used index to evaluate the activity of cancer. The precision of SUV is directly affected by the local statistical noise in PET images because SUV is calculated based on the counts on PET image data. The purpose of this study was to estimate the local statistical noise in the PET image caused by attenuation of annihilation photons inside the body. ⋯ Our algorithm favorably estimated the local statistical noise in PET image data using CT image data, regardless of object size, although the consideration was limited for phantoms with homogeneous interiors.
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The deep inspiration breath-hold (DIBH) technique for positron emission tomography/computed tomography (PET/CT) is under investigation for its contribution to the accurate diagnosis of pulmonary lesions. "Step and shoot" or multi-bed-position image acquisition is necessary to improve the accuracy of whole-lung evaluation. The purpose of this study was to describe the method and preliminary results of evaluating pulmonary lesions using multi-bed-position deep inspiration breath-hold (MDIBH) PET/CT. ⋯ The MDIBH-PET/CT can provide better-aligned fused images, featuring superior image quality, in both PET and CT images. The PET images showed low BG, non-blurring and high TBRs, and the CT images provided diagnostic capability of detecting small pulmonary lesions with negligible radiation exposure.
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The transition of microglia from the normal resting state to the activated state is associated with an increased expression of peripheral benzodiazepine receptors (PBR). The extent of PBR expression is dependent on the level of microglial activation. A PBR ligand, [(11)C]PK11195, has been used for imaging of the activation of microglia in vivo. We evaluated whether [(11)C]PK11195 PET can indicate differences of microglial activation between no treatment and lipopolysaccharide (LPS) treatment in a rat artificial injury model of brain inflammation. ⋯ The results suggest that intensity of PBR signals in [(11)C]PK11195 PET may be related to the level of microglial activation rather than the number in activated microglia at least in an artificial brain injury model.