Figure 1a. Acute pulmonary embolism and deep venous thrombosis (DVT) in a 48-year-old woman. (a) Contrast material-enhanced pulmonary CT arteriogram (1.25-mm collimation) obtained at the level of the basal subsegmental pulmonary artery shows multifocal low-attenuation emboli (arrows) in segmental and subsegmental arteries in the right lower lobe. (b) Contrast-enhanced indirect CT venogram (5-mm collimation) obtained at the level of the pelvic inlet 3 minutes after injection shows large low-attenuation thrombi filling the left common iliac vein (arrow).