State-of-the-Art Imaging in Pulmonary Embolism: Ventilation/Perfusion Single-Photon Emission Computed Tomography versus Computed Tomography Angiography - Controversies, Results, and Recommendations from a Systematic Review.

Pulmonary embolism (PE) is a common, ubiquitous, and potentially lethal disease. As symptoms and clinical findings are notoriously nonspecific, diagnostic imaging is essential to avoid undertreatment as well as overtreatment. Controversies remain regarding first-line imaging in suspected PE. The two main contemporary contenders are ventilation/perfusion scintigraphy with single-photon emission computed tomography (V/Q SPECT) with or without additional low-dose CT (SPECT/CT) and CT angiography (CTA). We present our results from a systematic review and meta-analysis of the diagnostic performances of these modalities: V/Q SPECT, V/Q SPECT/CT, and CTA are all viable options, but we consider V/Q SPECT/CT to be superior in most clinical settings with better overall diagnostic performance, that is, pooled sensitivities (97.6 vs. 82.0%), specificities (95.9 vs. 94.9%), positive predictive values (93.0 vs. 93.8%), negative predictive values (98.6 vs. 84.7%), and accuracies (96.5 vs. 88.6%). We further address some of the ongoing controversies regarding the various modalities, that is, radiation exposure, the issues of subsegmental PE, nondiagnostic studies, and various challenges in specific patient populations. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.