Journal of nuclear medicine : official publication, Society of Nuclear Medicine
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Under ordinary circumstances a toddler's fracture of the lower extremity is diagnosed by clinical evaluation and history. Often the initial conventional radiograph is unrevealing, but the fracture is diagnosed and treated based on appropriate clinical and laboratory findings. ⋯ Skeletal scintigraphy in this small group of patients has been valuable in defining a spiral fracture of the midshaft of the tibia connected with a toddler's fracture. We report the scintigraphic appearance from the findings in six patients with unsuspected toddler's fracture evaluated by this method.
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Paget's disease of the bone occasionally transforms into sarcomatous tumors such as osteosarcoma. While Paget's disease demonstrates markedly increased uptake of bone scanning radiopharmaceutical, osteosarcomas complicating this condition often show decreased uptake. An unusual scan appearance of the osteosarcoma is presented in which the tumor showed intense uptake of the tracer on the bone scan. The extent of the sarcoma as delineated by the bone scan corresponded closely to the size of the lesion as seen on computerized tomography and magnetic resonance imaging and was confirmed at surgery.
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Radioaerosol inhalation lung cine-scintigraphy and lung function tests were performed on ten patients with bronchial asthma in remission before and after inhalation of salbutamol following intravenously administered aminophylline. Radioaerosol inhalation lung cine-scintigraphy was very useful in revealing the changes not only in the deposition patterns of inhaled aerosol in the lungs but also in the dynamic transport of mucus on the airways. ⋯ Lung function data including FVC, FEV 1.0, FEV 1.0%, MMF, V50 and Vp significantly improved after the treatment. There was, however, little visual or quantitative improvement in mucociliary clearance after the treatment.
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Comparative Study
Comparison of technetium-99m MAG3 kit with HPLC-purified technetium-99m MAG3 and OIH in rats.
Technetium-99m (99mTc) mercaptoacetylglycylglycylyglycine (MAG3) in high (greater than or equal to 95%) radiochemical purity is prepared from lyophilized kits containing benzoylMAG3, sodium tartrate, lactose, and stannous chloride by adding sodium [99mTC]pertechnetate and heating the contents briefly. Constant-infusion renal whole-blood clearance obtained with [99mTc] MAG3 kits was compared with that obtained with high performance liquid chromatography (HPLC) pure [99mTc]MAG3 and with co-infused iodine-131 (131I) iodohippurate (OIH) in anesthetized rats. Average renal whole-blood clearance of [99mTc]MAG3 from kits was 3.9 +/- 0.4 ml/min/100 g body weight (mean +/- s.e.m. n = 5) and that for HPLC-pure [99mTc]MAG3 was 4.6 +/- 0.3 (n = 3). ⋯ To assess possible interference from hepatobiliary uptake and excretion in renal failure, radioactivity in liver regions of interest was followed by gamma camera scintigraphy for 30 min after intravenous injection of [131I]OIH and kit and HPLC-purified [99mTc]MAG3 in anesthetized rats rendered anephric by ligating renal peduncles. Liver activity was 25% of total for both preparations of [99mTc]MAG3 and was 22% of total for [131I]OIH. There were no significant differences among the substances.
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To establish the effect of the paramagnetic contrast agent gadolinium diethylenetriaminepentaacetic acid ([Gd]DTPA) on myocardial magnetic resonance relaxation parameters T1 and T2, and its relationship to myocardial perfusion, we administered [Gd] DTPA 0.2 mM/kg to two groups of dogs. Group I had severe, resting myocardial ischemia induced by coronary occlusion, followed in 2 min by [Gd]DTPA infusion and heart excision 1 min later. Group II had a variable reduction in blood flow. ⋯ Although vasodilatation delivered more Gd-DTPA to the normal myocardium in Group II, the lack of further decrease in T1 suggested that it was cleared more rapidly. Thus, [Gd]DTPA permits the detection and characterization of severe, resting myocardial ischemia by magnetic resonance techniques. Using the experimental techniques described in this study, less severe flow differences caused by vasodilatation and resultant hyperemia are not detected.