Computed tomographic pulmonary angiography

In diagnostic imaging, computed tomographic pulmonary angiography is a form of x-ray computed tomography for examining the pulmonary vessels.

Pulmonary embolism
Assessing the accuracy of CT pulmonary angiography is hindered by the rapid changes in the number of rows of detectors available in multidetector CT (MDCT) machines. The PIOPED II study used a mixture of 4 slice and 16 slice scanners and reported a sensitivity of 83% and a specificity of 96%. This study noted that additional testing is necessary when the clinical probability is inconsistent with the imaging results.
 * Role in diagnosis

Two systematic reviews and two more recent randomized controlled trials  have studied prognosis after a negative CTPA.
 * Role in Prognosis==