Discordance between CT aniography in the PIOPED II study

Purpose To retrospectively evaluate the causes of discordant computed tomographic (CT)-angiographic readings from Pospective Investigation of Pulmonary Embolism Diagnosis, or PIOPED, IIstudy. Materials and Methods: Institutional review board approval was obtained for this HIPAA-compliant study. Of 1036 patients suspected of having pulmonary embolism who were examined with CT, 226 underwent angiography; 206 patients had concordant results and 20 had discordant results according to two readers. Of these 20 patients, 10 were men and 10 were women (mean age, 49 years). Among the 20 and 10 were won studies with discordant results, central readers identified seven cases as negative and 13 as positive for pulmonary embolism at CT these findings were reversed at angiograp isons of discordant studies were performed in consensus. The tiryie between CT and angiography and all locations of pulmonary embolism vasculat territory were recorded. The McNemar binomial test was used. Result One patient had false-positive findings at angiography, 13-negative findings at angiography, and patients had false two patients had false-negative findings at CT. Four patients had true-negative findings at CT; however, findings for thrombus at angiography. The sensitivity were positi for the detection of pulmonary embolism was 87% for CT and 32% for angiography (P = .007). The largest missed thrombus at: was subsegmental in eight paangiograpliv , segmental in two patients, and lobar in three paV tients; at CT it was subsegmental in two patients. The I mean time between CT and angiography was 40 hours 21 (standard deviation) (range, 10-97 hours). Conclusion: In the interval between CT and angiography, thrombi can remain the same, resolve, develop, or result from angiography. (c) RSNA, 2007