Acute Pulmonary Artery Embolism Detected by Noncontrast Functional Lung Magnetic Resonance Imaging.

A 30-year-old woman presented to the emergency department with acute shortness of breath, dizziness, and left-sided thoracic pain. The patient had been diagnosed with adenocarcinoma of the lung and metastases in central nervous system, liver, and bones 2 years earlier. After initial radiation and chemotherapeutic treatment, the patient showed a mixed response and was subsequently treated with the tyrosine-kinase inhibitor crizotinib, as well as further radiation of the progressive and symptomatic cerebral metastases. On admission, the patient was afebrile, displayed unimpaired oxygen saturation in room air, and presented with mild pitting edema of the calves. The ECG was without pathological findings and d-dimers were slightly elevated. Because of her clinical presentation and the increased pretest probability (clinical presentation and cancer diagnosis), a contrast-enhanced multidetector computed tomography was conducted to test for pulmonary embolism (PE). Multidetector computed tomography, however, showed no thrombotic mass in the main and segmental pulmonary arteries but a subpleural wedge-shaped consolidation, rated suspicious for beginning ischemic pneumonia, for example, because of subsegmental embolism, which is commonly missed by conventional multidetector computed tomography (Figure 1). The patient consecutively underwent ventilation and perfusion single-photon emission computed tomography (SPECT), which revealed a mismatch consisting of a perfusion defect in segments 8 and 9 of the left lower lobe …