Several new derivatives of lidocaine were synthesized and used to examine the intra- and extrahepatic bile ducts and gallbladder. Diisopropyl-IDA exhibited approximately twice the bile concentration of 131I-rose bengal during the first hour after injection. P-butyl-IDA also concentrates moderately well in the bile and has the added advantage of very low excretion into the urine (2%). It seems more effective than the other IDA derivatives at high bilirubin levels.

Foot-shock stress resulted in a threefold increase in myocardial uptake of technetium-99m-methylene diphosphonate (Tc-99m-MDP) in rats compared to unstressed controls. The introduction of a 4-sec signal prior to each shock resulted in a two-thirds reduction in this stress-induced Tc-99m-MDP myocardial uptake, suggesting that most of the stress-induced myocardial damage was psychologically mediated.

Acute experimental pulmonary arterial occlusions were produced in 5 dogs. The chest was subsequently imaged with computed tomography (CT), 99mTc-MAA scintigraphy, and plain radiography. Gamma images revealed all 6 lesions, and plain radiographs were uniformly negative. Enhanced CT scans demonstrated 3 of 5 lesions, and unenhanced scans revealed 1 of 6. CT findings were variable.

Computed tomography of the chest or abdomen may reveal vertebral abnormalities. Images in multiple projections of dry and fresh specimens of the spine demonstrate that osteophytes, end-plate irregularities, and marked obliquity fail to mimic true osteoblastic vertebral lesions. Disk calcification may simulate a metastatic deposit if the section includes both disk and vertebral body. Abdominal or chest "window" settings produce an apparent increase in bone density. Analysis of the bony spine from abdominal and chest images requires gray scale settings different from those used for the study of visceral organs.

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