Biomedical subjects
Publications and source records attributed to J R Perry.
Following the oral administration of 75Se-selenofolate in two normal healthy volunteers, retention was measured by whole body counting, and distribution throughout the body was determined with a hybrid scanner. Approximately 65% of the dose was absorbed from the GI tract. The metabolic data obtained from this study was used to calculate the integrated radiation dose to the liver, and the effective dose equivalent.
We studied 243 patients in whom 248 pulmonary angiograms were performed because of suspected pulmonary embolism. Ventilation and perfusion lung scanning in 140 of them revealed 38 to be in low and high probability groups. Of 19 patients with subsegmental and nonsegmental perfusion defects that were matched with ventilation defects, none had pulmonary embolism. Conversely, angiography was positive in 17 of 19 patients with multiple segmental or lobar perfusion defects in areas of normal ventilation. Doppler flow examinations of the veins of the legs showed normal flow in 61 of 79 (77 percent) patients with pulmonary emboli and, therefore, were insensitive indicators of embolism. There was no mortality from angiography, and serious complications occurred in 2 percent of the patients. Anticoagulation in 83 patients was associated with bleeding in 25, two of whom died. The data indicate that ventilation-perfusion lung scanning can be used to separate many of the patients suspected of having pulmonary embolism who need anticoagulant treatment from those who do not. However, there is a considerable number of patients with nonspecific abnormalities on lung scan. For this group of patients with nonspecific abnormalities, the risk of complications from empiric treatment with anticoagulant drugs is probably greater than the risk of complications from pulmonary angiography. Further, our data show that patients with negative angiography have a very low risk of subsequent pulmonary embolism. In this group of patients, therefore, pulmonary embolism should be demonstrated by angiography before long-term anticoagulant therapy is prescribed.
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The arterial and venous volume blood flow in the dominant and nondominant upper extremities of five male pitchers, ages 16 to 21, was measured using color flow duplex ultrasound. Blood-flow measurements were obtained at baseline, after warm-up, and after each sequence of 20 pitches until 100 pitches were thrown. Blood flow was additionally determined 1 hour after the last pitch. The velocity of each pitch was recorded with a speed gun. Anthropomorphic measurements of the upper extremity were obtained at baseline and immediately after Pitch 100 using a standard measuring tape. The highest average arterial volume flow in the pitching arm occurred after 40 pitches, reaching a peak of 549 ml/min (56% increase from baseline). Thereafter, the average arterial blood flow steadily declined, reaching an average of 402 ml/min after the 100th pitch (14% increase from baseline). In contrast, the arterial blood flow in the nonpitching arm increased only slightly from baseline, reaching a maximal volume flow of 448 ml/min immediately after the warm-up period (10% increase from baseline). The volume flow then persistently fell to a level 30% below baseline after the 100th pitch. Although this small pilot study does not demonstrate causation between a decline in pitching performance and arterial blood flow, it suggests arterial flow in the dominant extremity falls as the pitch count increases.
Better communications are essential in the new medical environment. Methods to make more efficient the throughput in an existing department, foster confidence of patients, and improve the communications and efficiency of referring physicians are needed. The most difficult and thus the driving component of the new communications environment is image transmission. Concepts of picture archiving and communications systems, or PACS, arising from digital technology make possible unique and ubiquitous solutions to image communications. Better quality control and improved interpretation throughout the system, including the offices of referring physicians, will be possible. Radiologists are in a position to mold this new medical industry.