Effect of vasospasm on perfusion radionuclide imaging in experimental pulmonary embolism

Journal Article · · Invest. Radiol.; (United States)

DOI:https://doi.org/10.1097/00004424-198309000-00012· OSTI ID:7015900

Feigin, D S; Bookstein, J J; Alazraki, N P

Experiments were conducted to further evaluate previously observed discrepancies between postembolic perfusion scans and angiograms, and the relationship of these discrepancies to pulmonary vasospasm. Nonresorbable emboli were formed from Ivalon, muscle, or heated autologous clot. Scans and angiograms were compared at 24-hour intervals for two to eight days. During the first two days after embolism, angiographic-scan discrepancies occurred in most dogs, characterized by decreased size of scintigraphically demonstrated perfusion defects at the same times that the angiogram showed stable or even progressive obstruction. This discordant behavior of scan and angiogram is thought to reflect subsidence of postembolic vasospasm. In the 17 experimental dogs, 13 showed evidence of vasospasm, and four did not. In those that developed spasm, direct angiographic evidence of such spasm was present in all but one, manifest as diffuse constriction of small arteries and diminished parenchymal stain in vascular beds that were not directly obstructed mechanically. Although spasm diminished rapidly during the first 6 hours, there was continued and appreciable further resolution for over 48 hours in some dogs. This study reconfirms the frequent existence of vasospasm in three different embolic models, and indicates subsidence of spasm over a much longer time frame than was formerly supposed. Regression of spasm over an interval of several days suggests that perfusion scans should be performed clinically as soon as possible after a suspected embolic episode, prior to subsidence of spasm, in order to exploit the added sensitivity provided by spasm.

• Research Organization: Veterans Administration Hospital, La Jolla, CA
• OSTI ID: 7015900
• Journal Information: Invest. Radiol.; (United States), Journal Name: Invest. Radiol.; (United States) Vol. 18:5; ISSN INVRA
• Country of Publication: United States
• Language: English

Related Subjects

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62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
BIOMEDICAL RADIOGRAPHY
BODY
COMPARATIVE EVALUATIONS
COUNTING TECHNIQUES
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
DISEASES
DOGS
EMBOLI
LUNGS
MAMMALS
MEDICINE
NUCLEAR MEDICINE
ORGANS
RADIOISOTOPE SCANNING
RADIOLOGY
RESPIRATORY SYSTEM
RESPIRATORY SYSTEM DISEASES
VERTEBRATES