Discordance between CT and angiography in the PIOPED II study

Area of Science:

• Radiology
• Cardiovascular Imaging
• Pulmonary Embolism Diagnosis

Background:

• Pulmonary embolism (PE) diagnosis relies on imaging modalities like computed tomography (CT) and angiography.
• Discordant readings between CT and angiography can lead to diagnostic challenges.

Purpose of the Study:

• To retrospectively evaluate the causes of discordant computed tomographic (CT)-angiographic readings in the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) II study.

Main Methods:

• Retrospective analysis of 1036 patients suspected of PE, focusing on 20 cases with discordant CT-angiography results.
• Comparison of CT and angiography findings by central readers and consensus review.
• Analysis of time interval between CT and angiography and thrombus location.

Main Results:

• CT sensitivity for PE detection was 87% versus 32% for angiography (P=.007).
• Angiography had a higher rate of false negatives (13 patients) compared to CT (2 patients).
• The time between CT and angiography averaged 40 hours, during which thrombi could change.

Conclusions:

• Discordant CT-angiography readings in PE diagnosis can arise from changes in thrombus status between imaging studies.
• Thrombi may resolve, develop, or remain unchanged in the interval between CT and angiography.
• Angiography may also introduce findings that contribute to discrepancies.