Radiology
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Idiopathic pulmonary ossification is an uncommon and asymptomatic disorder of unknown etiology in which trabeculated bone is found in the lung. It is usually mistaken for more serious entities radiographically, most commonly appearing as branching linear shadows of calcific density involving a limited area of the lung and exhibiting very slow progression; however, the shadows may be round or irregular and bulky. Sometimes the trabeculae are recognizable, and occasionally the lungs demonstrate widespread involvement. The authors describe 8 proven cases, including one in which a bone scan revealed uptake by heterotopic bone in the lung.
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A method for determining absolute left ventricular (LV) volumes from radionuclide gated blood-pool (GBP) images was validated in 34 patients. The technique is nongeometric, corrects for tissue attenuation, and uses an experimentally determined set of build-up factors to account for the effects of scatter. ⋯ Phantom studies showed less than 4% error for volume determinations at all investigated depths. For the patients studied the correlation between volumes obtained by GBP and contrast ventriculography was 0.97 for diastole and 0.96 for systole.
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A spectrum of rare urachal abnormalities in the adult is described, including urachal cyst, infected urachal cyst and abscess, and urachal carcinoma. The clinical and radiographic features are presented, and diagnosis using ultrasound, computed tomography, and needle aspiration is discussed. Treatment of infected urachal cysts with percutaneous catheter drainage is described.
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Comparative Study
New diphosphonate compounds for skeletal imaging: comparison with methylene diphosphonate.
Three-hour biodistribution of Tc-99m complexes of six diphosphonates was compared in rabbits with tibial lesions to determine which was best for detection of focal bone lesions. Sr-85 was used as a standard. ⋯ They also exhibited much higher uptake in the liver and kidney, as well as muscle and red marrow in the case of DPD. None was superior to MDP as an all-purpose skeletal agent, though others may be better for specific applications.
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The accuracy of radiographic detection of neurosurgical sponges was measured experimentally. Commercially available sponges were inserted into a cadaver in several paravertebral locations and radiographed. ⋯ Mean false-negative and false-positive rates were both about 10%. In addition, false-negative rates varied between 3 and 25% according to the type of sponge.