Ventilation-perfusion scintigraphy in children and adolescents is associated with a low rate of indeterminate studies

In selected populations, ventilation-perfusion (V/Q) studies are nearly as accurate as CT angiography (CTA) for the diagnosis of pulmonary emboli (PE). This study was performed to determine the percentage of V/Q studies in children and adolescents that are indeterminate for the presence of PE.

V/Q studies performed over a period of 2 years were reviewed. Studies from children and adolescents with chronic lung disease or recent documented severe PE were excluded. There were 37 V/Q studies and 3 perfusion only (Q) studies in 35 patients. Studies were evaluated using modified Biello criteria. Effective doses (EDs) for V/Q and CTA studies of the lung were calculated from administered activities and CT exposure parameters used.

Eighteen studies were normal, 4 studies had a very low probability of PE, 6 were low probability, and 2 were high probability for PE. Four studies were negative for new PE when compared with a previous study. Five V/Q studies and 1 Q only study were indeterminate for PE (15%), only slightly higher than the reported percentage of indeterminate CTA in adults. ED from V/Q was about half the ED from CT angiography. Breast dose from V/Q was less than 3% of the breast dose from CT.

In this selected group of children and adolescents, the percentage of indeterminate V/Q studies is low. V/Q has considerably lower absorbed breast and effective radiation doses than CTA, and is still appropriate for imaging children who are suspected of having PE.