Radiology
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To evaluate the relationship between extravascular lung water, pulmonary capillary wedge pressure, and chest radiographic findings, extravascular lung water (EVLW) was assessed using double indicator-dilution techniques in 34 adult patients with mitral stenosis. Seven patients were studied 6 to 12 months after successful mitral valve replacement. In the 27 preoperative patients, septal lines were found to be indicative of elevated EVLW only in the presence of intravascular congestion. ⋯ Postoperatively, septal lines were invariably associated with normal filling pressures and EVLW. Thus in both preoperative and postoperative mitral stenosis patients, interstitial Kerley B lines are insensitive markers of elevated extravascular lung water in the absence of pulmonary vascular engorgement. This emphasizes the importance of interpreting radiographic findings of extravascular fluid in conjunction with evaluation of the vascular bed in patients with chronic postcapillary hypertension.
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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.