Evaluation of the nonpregnant adult with intermediate probability of pulmonary embolism

PE: pulmonary embolism; CT: computed tomography.
* We prefer the Wells criteria to determine the pretest probability of PE, although the modified Geneva score or clinical gestalt is also appropriate. Refer to UpToDate text for details.
¶ Some experts proceed directly to CT pulmonary angiography in patients on the higher end of the intermediate risk spectrum (eg, Wells score 4 to 6) or in those with limited cardiopulmonary reserve.
Δ Feasibility requires adequate scanner technology. Also the patient must be able to lie flat, to cooperate with exam breath-holding instructions, have a body habitus that can fit into scanner, and no contraindications for iodinated contrast.
◊ Repeat CT pulmonary angiography for more definitive results may be worthwhile if the factor causing poor image quality can be mitigated (eg, patient more capable of cooperating with positioning and breath-holding instructions). Repeat imaging is unlikely to prove useful if exam was nondiagnostic due to factors such as scanner technology, body habitus, or indwelling metallic foreign bodies.
§ Feasibility requires a chest radiograph demonstrating clear lungs and a patient able to lie still for >30 minutes.
¥ Further testing first involves revisiting the feasibility of CT pulmonary angiography. If CT pulmonary angiography is still not feasible then lower extremity compression ultrasonography with Doppler is appropriate.