Screening of pulmonary embolism by ventilation / perfusion tomography-SPECT and comparation with planar...

Pulmonary embolism (PE) affects up to 1 per 1000 people every year and is one of the commonest preventable causes of death among hospital inpatients. Laboratory chemical test alone cannot confirm or exclude PE but are used together with the clinical test probability for risk stratification. Ventilation/ perfusion tomographic imaging may be the best practical way to accomplish on this larger scale. The aim of this study was to screen the pulmonary embolism by ventilation/perfusion tomography V/P SPECT. We also compared V/P SPECT with planar scintigraphy.

A total of 40 patients with clinically suspected pulmonary embolism were examined. Fifteen patients (37.5%) considered to have perfusion defect with preserved ventilation using ventilation/ perfusion tomography-SPECT. In this group five patients (33%) had multiple perfusion defects (RoPer = 16 poens, RoVent = o poens). Correlation coefficient has been sign among visual analysis and quantitative analysis (C = 0.510). In 25 patients (62.5%) we have found normal ventilation/ perfusion scintigraphy. On the planar scintigraphy PE with high probability was considered in five (26.6%) patients. Intermediate and low probability was considered in seven patients with planar ventilation/ perfusion scintigraphy. Sub-segmental perfusion defect with preserved ventilation we have found in two patients (13%). On the planar scintigraphy the same defect was unclear.

Ventilation/ Perfusion tomography-SPECT is clinically relevant in the diagnosis of pulmonary embolism, and may help reduce the number of non-diagnostic scintigraphy results. On the planar perfusion scintigraphy patients tended to have fewer perfusion defects corresponding pulmonary embolism.