VENTILATION-PERFUSION LUNG IMAGING AND SELECTIVE PULMONARY ANGIOGRAPHY IN DOGS WITH EXPERIMENTAL PULMONARY-EMBOLISM

  • 1 January 1978
    • journal article
    • research article
    • Vol. 19  (2) , 164-171
Abstract
To determine the accuracy and limitations of 133Xe ventilation and 99mTc perfusion lung images (V-P images) in detecting pulmonary emboli (PE), these studies were performed in 23 dogs after experimental production of PE by a modified Wessler technique. Of the animals (14) also underwent selective pulmonary angiography. 133Xe abnormalities were seen immediately after embolization in 2 of the 23 animals (8.7%). Perfusion images revealed the location of 83% of emboli that completely obstructed pulmonary vessels, but only 26% of those that partially obstructed flow. Defects were seen with 97% of emboli that completely occluded vessels larger than 2.0 mm in diameter, but in only 66% of those occluding smaller vessles. Oblique perfusion images provided the only evidence of the perfusion defect associated with 5 of 88 (5.7%) angiographically proven emboli. V-P imaging is a sensitive technique for detecting PE unless the emboli lodge in very small vessels or incompletely obstruct a vessel. 133Xe abnormalities occur infrequently following PE and should not be a common cause for a false-negative V-P match in clinical practice.