Journal of nuclear medicine : official publication, Society of Nuclear Medicine
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Comparative Study
Performance characteristics of a newly developed PET/CT scanner using NEMA standards in 2D and 3D modes.
This study evaluates the 2-dimensional (2D) and 3-dimensional (3D) performance characteristics of a newly developed PET/CT scanner using the National Electrical Manufacturers Association (NEMA) NU 2-1994 (NU94) and NEMA NU 2-2001 (NU01) standards. The PET detector array consists of 10,080 individual bismuth germanate crystals arranged in 24 rings of 420 crystals each. The size of each crystal is 6.3 x 6.3 x 30 mm in the axial, transaxial, and radial dimensions, respectively. The PET detector ring diameter is 88.6 cm with axial and transaxial fields of view (FOVs) of 15.7 and 70 cm, respectively. The scanner has a uniform patient port of 70 cm throughout the PET and CT FOV, and the PET scanner is equipped with retractable septa to allow 2D and 3D imaging. ⋯ The results show excellent system sensitivity with relatively uniform resolution throughout the FOV, making this scanner highly suitable for whole-body studies.
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Letter Practice Guideline Guideline
Exemption of radiopharmaceuticals from <797>.
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Comparative Study Clinical Trial Controlled Clinical Trial
Tomographic imaging in the diagnosis of pulmonary embolism: a comparison between V/Q lung scintigraphy in SPECT technique and multislice spiral CT.
Although ventilation/perfusion (V/Q) lung scintigraphy is a well-accepted and frequently performed procedure in the diagnosis of pulmonary embolism, there is growing controversy about its relevance, particularly due to the increasing competition between scintigraphy and CT. Even though comparative studies between both modalities have already been performed, their results were highly inconsistent. Remarkably, in most of those studies, conventional planar perfusion scans were compared with tomographic images acquired using state-of-the-art CT scanners-a study design that cannot give impartial results. Hence, the aim of our study was a balanced comparison between V/Q lung scintigraphy and CT angiography using advanced imaging techniques for both modalities. ⋯ SPECT and ultrafine aerosols are technical advancements that can substantially improve lung scintigraphy. Using advanced imaging techniques, V/Q scintigraphy and multislice spiral CT both yield an excellent and, in all aspects, comparable diagnostic accuracy, with CT leading in specificity while SPECT shows a superior sensitivity. Even though planar lung scintigraphy yields satisfactory results for a nontomographic modality, it does not compare with tomographic imaging.
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Comparative Study Clinical Trial Controlled Clinical Trial
Ursodeoxycholic acid-augmented hepatobiliary scintigraphy in the evaluation of neonatal jaundice.
Early differentiation of extrahepatic biliary atresia from intrahepatic cholestasis is important. Hepatobiliary scintigraphy is an excellent noninvasive investigation for ruling out extrahepatic biliary atresia. This study aimed at identifying the role of ursodeoxycholic acid (UDCA), a choleretic agent, in conjunction with hepatobiliary scintigraphy in differentiating extrahepatic biliary atresia from neonatal hepatitis. ⋯ Pretreatment with UDCA significantly improves the specificity of hepatobiliary scintigraphy in ruling out extrahepatic biliary atresia as a cause of prolonged neonatal jaundice.