RT Journal Article
SR Electronic
T1 The low specificity of postoperative perfusion lung scan defects
JF Canadian Medical Association Journal
JO CMAJ
FD Canadian Medical Association
SP 153
OP 158
VO 124
IS 2
A1 Walker, I.
A1 Aukland, P.
A1 Hirsh, J.
A1 Coates, G.
A1 Cockshott, P.
A1 Taylor, R.
A1 Hull, R.
YR 1981
UL http://www.cmaj.ca/content/124/2/153.abstract
AB Ventilation and perfusion lung scans were performed preoperatively and postoperatively in 169 patients and classified blindly according to preset criteria. Perfusion lung scan abnormalities were present in 25 (15%) of the preoperative scans and 42 (25%) of the postoperative scans; 16 (38%) of the 42 abnormal postoperative scans were identical to the preoperative scans. Perfusion defects indicating a "high probability" of pulmonary embolism (lobar or segmental defects) were present in 5 preoperative scans and 10 postoperative scans; the 10 postoperative scans were classified as showing "definite" (5), "possible" (1) or "no" (4) pulmonary embolism on the basis of the preoperative scan and the ventilation scan; none of the 10 patients had clinical evidence of pulmonary embolism. Venous thrombosis was present in 12 patients, including 4 of the patients whose lung scans showed definite pulmonary embolism. Thus, postoperative perfusion lung scan defects are potentially misleading even when large.