Introduction of helical CT started a new era in the diagnosis of PE. It is noninvasive and readily available. Developments in helical CT technology (particularly introduction of multidetector scanners) improved image quality by decreasing the scanning time and slice thickness. With the addition of indirect CT venography to CT pulmonary angiography, CT also took the role of venous ultrasound, thus creating a single examination for diagnosis of VTD. On the other hand, CT is not perfect at all circumstances, especially in the evaluation of subsegmental arteries. Careful selection of patients for imaging studies will save time, cost, and radiation.