Assessment of Pulmonary Photoscanning and Angiography in Experimental Pulmonary Embolism

Abstract

The diagnostic reliability and specificity of pulmonary angiography and perfusion photoscanning were examined by applying both technics in two series of dogs: one subjected to multiple small pulmonary emboli; the other, to massive embolization. Interpretations of the angiograms and photoscans by two observers were correlated with each other and autopsy data. Analysis disclosed a high degree of agreement between the two technics. Application of both technics, however, led to a greater incidence and accuracy of embolic detection than either method provided alone. Both technics were subject to interpretive errors leading to false positive and false negative diagnoses. The factors promoting such errors are discussed. It is concluded that the two technics are complementary, not competitive, and that each is least reliable in detecting emboli at the extremes of size.

Pulmonary perfusion defects in postoperative chest infections

“…The further observation by Moser et al (1969) of a high degree of correlation between the isotope scan and the pulmonary angiogram further enhanced the potential value of the scan.…”

Ventilation-Perfusion Lung Scanning for Pulmonary Emboli

“…With experimentally induced emboli in dogs the overall false negative rate was 17%, the emboli being missed either because they involved very small areas of lung or because they lodged centrally, causing only partial obstruction to flow (Moser et al 1969). This has not yet been confirmed in man.…”

Resolution of Experimental Pulmonary Emboli with Heparin and Streptokinase in Different Dosage Regimens

“…Difficulties, however, have been experienced with the quantitation of experimental pulmonary emboli (13,26,49,50). Pulmonary angiography (13,(49)(50)(51)(52) and lung scanning (50,52,53) are semiquantitative and postmortem recovery of the embolic material (50,51,54,55) while more quantitative may fail to include the emboli from all the very small vessels. We have therefore used an alternative method which permitted more accurate quantitation of the degree of resolution of experimental pulmonary emboli.…”