Fig. 1A.Positive, negative, and indeterminate pulmonary CT
angiograms. Pulmonary angiogram of 56-year-old man shows filling defect and
surrounding contrast material at segmental branching of right lower lobe
pulmonary artery. Thrombus is also present in medial right middle lobe
segmental pulmonary artery.
Fig. 1C.Positive, negative, and indeterminate pulmonary CT
angiograms. Indeterminate pulmonary CT angiogram of 51-year-old man shows poor
bilateral opacification of segmental pulmonary arteries that prevents
detection of intraluminal filling defects.