SPECT perfusion lung scintigraphy in children with chronic pulmonary damage: Preliminary results of a prospective study

The aim of this study was to describe SPECT perfusion lung scintigraphy findings in symptomatic children with chronic pulmonary damage. Material and Method: We studied 111 children (average age:3.9 yr, range:1 month- 15 yr, 61.3% boys) with chronic pulmonary pathology. The most common clinical diagnosis reported in this population were recurrent bronchopneumonia (45.9%), unknown origin chronic pulmonary damage (36.9%), chronic obstructed bronchitis (27.9%), adenovirus bronchopneumonia sequelae (27.9%) and bronchopulmonary dysplasia (14.4%). The SPECT lung perfusion scintigraphy (LS) was performed in a SMV DST XLi two headed gammacamera, 64x64 matrix, 32 steps of 15 sec each, using a HRLE collimator, after i.v. injection of a age-adjusted dose of Tc99m-MAA. The images were reconstructed using a iterative-post filter method and displayed in tomographic slices and 3D form. We took also planar images in frontal and posterior projections to assess the differential perfusion. The studies were separated according to scintigraphy findings and gender. Results: Ninety eight (88.3%) of realized LS were abnormal (59.2% boys). Fifty three (54.1%) of abnormal scans showed bilateral alterations, being this finding significantly (p:0.034) more frequent in boys (63.8% bilateral lesions) than in girls (40.0% bilateral lesions). When unilateral altered scans were analyzed, the right lung was more frequently affected than left lung (73.5% vs 26.5%) (p:0.002). Of whole abnormal group, 19.4% had diffuse perfusion alterations, 46.9% showed focal alterations and 33.7% had a mixed diffuse-focal pattern. In focal alterations group, the majority presented a segmental distribution (83.7%), being the more frequent localizations the right inferior lobe (39.8%), right upper lobe (34.7%) and left inferior lobe (34.7%). Sixteen patients (16,3%) had focal non-segmental alterations, being situated mainly in upper middle of right lung (47.6%). The range of differential perfusion quantification in abnormal scans was 27%-96% in right lung (average:52.9%, SD:10.8) and 4%-73% in left lung (average:47.1%, SD:10.8). In normal scan the range was 48%-55% in right lung (average:51.9%, SD:2.4) and 45%-52% in the left one (average:47.1%, SD:2.4). Conclusion: In symptomatic children with chronic pulmonary pathologies SPECT lung perfusion scintigraphy has a high rate of abnormality and bilateral involvement, especially in boys, showing mainly focal segmental perfusion alterations