Radiology, Vol 159, 647-651, Copyright © 1986 by Radiological Society of North America
Aortopulmonary window lesions: detection with chest radiography
PR Jolles, MS Shin and WP Jones
A retrospective morphologic study of 80 cases was undertaken to determine
factors affecting detectability of computed tomographically (CT) proved
aortopulmonary (AP) window lesions on conventional posteroanterior (PA) and
lateral chest radiographs. Criteria used for determining abnormality were:
solitary lymph node enlargement over 1.5 cm or three or more 1-cm nodes and
obvious large masses or vascular anomalies. CT scans and corresponding PA
and lateral radiographs were analyzed for lesion detectability, size, and
location. In 49% of cases there was no detectable lesion in the AP window
on radiographs; a definite AP window lesion was seen in 41%, and 10% were
equivocal. Major contributing factors to low detectability of AP window
lesions on radiographs include size and, more important, location of the
lesion. An additional 45 cases of CT-proved normal AP windows were
retrospectively reviewed to determine the false-positive rate of PA and
lateral radiographs in detection of AP window lesions: 43 (96%) were
classified as negative, the remaining two (4%) as equivocal. Although the
AP window is a small space, it is the site of many pathologic conditions;
the study results indicate that CT may be an essential procedure for its
evaluation.
