Technetium-99m-sulfur colloid SPECT imaging in infants with suspected heterotaxy syndrome

For the evaluation of a variety of hepatosplenic disorders, SPECT complements planar ^99mTc-sulfur colloid liver/spleen imaging. By isolating small, ectopic or poorly functioning spleen(s) from overlying or adjacent liver, SPECT imaging should facilitate identification of splenic tissue in infants with suspected heterotaxy syndrome. Methods: During a 10-yr period, 10 planar-only and 9 planar-plus-SPECT liver/spleen scans were obtained from 15 infants, 13 of whom were less than 1 mo of age at first examination. Four of the planar-only group had follow-up planar-plus-SPECT imaging. Scintigraphic diagnosis regarding presence of splenic tissue was correlated with clinical diagnosis. Results: Thirteen infants had splenic tissue; two were asplenic. Planar-only imaging provided correct diagnoses in six [four with, two without spleen(s)] but was negative or equivocal in four infants. Planar-plus-SPECT imaging was positive in all in whom it was performed; moreover, in 4/13 infants (31%), splenic tissue was documented only by SPECT imaging. Conclusion: Particularly when planar views are inconclusive, SPECT imaging is invaluable for identification and localization of functioning splenic tissue in infants with suspected heterotaxy syndrome.