UNLABELLED This study was performed to investigate lesions with ring-like thallium-201 (201Tl) uptake and to determine whether SPECT provides any information in differential diagnosis. METHODS A total of 244 201Tl SPECT images were reviewed. In each study, early (15 min postinjection) and late (3 hr) brain SPECT images were obtained with 111 MBq of 201Tl. The early uptake ratio (ER; lesion to...

BACKGROUND AND PURPOSE Differentiation of tumor recurrence from treatment-related changes may be difficult with conventional MR imaging when newly enhancing lesions appear. Our aim was to determine the value of perfusion-sensitive contrast-enhanced MR imaging for differentiating recurrent neoplasm from nonneoplastic contrast-enhancing tissue. METHODS Twenty patients in whom new enhancing lesi...

Introduction: It is a common protocol to use 201Tl for the rest and 99mTc for the stress cardiac SPECT imaging. Theoretically, both types of imaging may be performed simultaneously using different energy windows for each radionuclide. However, a potential limitation is the cross-contamination of scattered photons from 99mTc and collimator X-rays into the 201Tl energy window. We used a middle en...

BACKGROUND Several authors have reported cases in which 201Tl scintigraphy demonstrated perfusion abnormality in the septum of patients with left bundle branch block (LBBB) and normal coronary arteriogram. The mechanism of this abnormality, however, remains to be clarified. METHODS AND RESULTS To determine whether LBBB itself induces abnormal myocardial perfusion and ischemia and to elucidate...

UNLABELLED The evaluation of myocardial damage by [123I] 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) imaging, which represents free fatty acid metabolism, has not been reported in patients with Duchenne-type muscular dystrophy (DMD). To date, the relationship between clinical stage, prognosis and myocardial damage has not been evaluated by radionuclear cardiac imaging. The main g...

One hundred and eight patients with single and multiple vessel coronary artery disease confirmed by arteriography were evaluated by exercise thallium-201 (201Tl) myocardial scintigraphy to determine the scintigraphic appearances of specific coronary stenoses. In general proximal stenoses caused more widespread, but not necessarily more severe, myocardial tracer deficit than distal stenoses. In ...

UNLABELLED A poor signal-to-noise ratio attributable to a low injected dose of thallium and the presence of scattered photons are the major impediments in the use of thallium as an imaging agent. Thallium decays in a complicated way and emits photons in a wide range of energies (68-82 keV). To increase the ratios of primary photons to scatter photons (primary-to-scatter ratios) and possibly inc...