Competitive assessments of pulmonary embolism: Noninvasiveness versus the golden standard.

Diagnosis of suspected pulmonary embolism (PE) is crucial as undiagnosed and over-diagnosis can both lead to serious consequences. Contemporary diagnostic approach of PE is a sequential combination assessment beginning with clinical assessment, validated with D-dimer measurement and confirmed with pulmonary angiography or imaging. Since the invasive pulmonary angiography is risky and costly, imaging is a warranted tool in the diagnosis procedure. CT pulmonary angiography is a less-invasive method with general availability, studies provide favorable evidences for CT pulmonary angiography as a stand-alone test for excluding PE, and it has become the first choice of tests in emergency department for suspected PE in most centers. Ventilation/perfusion single-photon emission CT signifies a new era in nuclear medicine. It has excellent sensitivity and specificity, fast procedure, low radiation exposure, few complications and contradictions. Besides, MR angiography is another possible and promising approach for diagnosis of suspected PE with much safer contrast agents than CT and no ionizing radiation. With wide availability and less invasive effects, imaging becomes a firsthand tool to obtain optimal accuracy in the diagnosis work up in clinic nowadays. This review summarizes the current methods in diagnosing PE and the update of imaging assessments of the disease.