Diagnosis of pulmonary embolus by spiral CT: a case study.

A thirty-eight-year old immunosuppressed woman presented with respiratory distress and was diagnosed with Pneumocystis Carinii Pneumonia. Pulmonary embolism was also suspected on clinical grounds. A Ventilation-Perfusion Scan was indeterminate. Contrast-enhanced spiral computed tomography of the chest confirmed the presence of a central pulmonary embolus and helped to avoid pulmonary angiography in this critically ill patient.