Medical News Today -- When it comes to diagnosing pulmonary embolism - a sudden blockage in the lung artery that could be deadly if not treated - which technique is the most effective? Research published in the December issue of The Journal of Nuclear Medicine (JNM) suggests that a form of molecular imaging called single photon emission computed tomography (SPECT), when combined with low dose CT, may provide an accurate diagnosis - allowing physicians to improve care for patients suffering from this often critical condition by using a diagnostic test that does not expose the patient to a great deal of radiation.