Prevalence and clinical significance of solitary pulmonary sub-segmental microembolism.

Background: Solitary pulmonary microembolism is rarely discussed as a distinct diagnostic entity. The purpose of this investigation was to determine the prevalence and clinical significance of embolism limited to subsegmental branches in a group of patients discharged from hospital on anticoagulants with a diagnosis of pulmonary embolism based on ventilation-perfusion imaging followed by selective angiography.

Material And Methods: Of 29 consecutive patients with classic signs of pulmonary embolism at angiography, we identified a subgroup of 5 patients with sub-segmental embolism, which was solitary in all cases.

Scintigraphic probability and angiographic diagnostic certainty in acute pulmonary embolism.

The objectives of this study were to determine if diagnostic certainty on angiography correlates with scintigraphic probability for the diagnosis of pulmonary embolism. From a total of 160 consecutive patients who underwent both nuclear imaging and invasive selective pulmonary angiography, we reviewed the xenon-133 ventilation images in 2 posterior oblique views and the Tc-99m macroaggregated serum albumin perfusion scans and angiograms of 40 patients (15 men, 25 women; average age 57 years) who were discharged from the hospital on anticoagulants with a diagnosis of pulmonary embolism. The angiograms were reviewed and the diagnosis of embolism was considered certain in the presence of an intraluminal filling defect, a trailing embolus, or a branch occlusion equal to or larger than a segmental branch (n=29; 73%), and uncertain when the studies were reinterpreted as either equivocal or negative or in the presence of a single, small subsegmental filling defect of questionable clinical significance.