title: Increasing the accuracy of lung perfusion scintigraphy in children with bidirectional Glenn circulation.
abstract: BACKGROUND
  In children who have undergone a bidirectional Glenn procedure without antegrade or additional pulmonary blood flow, we have often noted a discrepancy between apparent lung perfusion on scintigraphy and superior vena cava angiography when evaluating right and left pulmonary blood flow. We found a tendency for radionuclide, tracer 99mTc-MAA, when administered through a single upper extremity vein, to preferentially accumulate in the ipsilateral lung.
  
  
  OBJECTIVE
  In the present study, we examined whether the ratio of right-to-left pulmonary flow varied when 99mTc-MAA was administered via either the right upper or the left upper extremity vein.
  
  
  METHODS
  We studied six children (median age 1.3 ± 0.23 years) who underwent a bidirectional Glenn before total cavopulmonary connection. Five children who underwent biventricular repair served as a control. Perfusion scintigraphy using 99mTc-labeled macroaggregated albumin (99mTc-MAA) was performed in all children. First, we injected radionuclide via the right upper extremity and calculated the pulmonary accumulation in both lungs (R-image). Second, we injected the same dose of radionuclide via the left upper extremity and calculated the pulmonary accumulation (B-image), which represented the resulting administration via both upper extremities. The lung accumulation that resulted from radionuclide administration via the left upper extremity (L-image) was determined by subtracting the R-image from the B-image. We evaluated the right-to-total pulmonary blood flow ratio (radionuclide accumulation in right lung / radionuclide accumulation in both lungs) in the R-, L- and B-images.
  
  
  RESULTS
  The right-to-total pulmonary blood flow ratios in the R-, L- and B-images were 815 ± 15.3%, 39.8 ± 11.7% and 61.3 ± 11.8%, respectively, and there were significant differences among the three images (P < 0.01). On the other hand, in the control group, the right-to-total pulmonary blood flow ratios in the R-, L- and B-images were 59.3 ± 22.4%, 57.8 ± 26.4% and 58.8 ± 23.7%, respectively, and there was no significant difference.
  
  
  CONCLUSIONS
  In children with bidirectional Glenn circulation without antegrade or additional pulmonary blood flow, the venous blood of each arm tends to flow into the ipsilateral lung. The administration of radionuclide via both arms is important for accurate evaluation of lung perfusion scintigraphy in children who have undergone a bidirectional Glenn procedure.
authors.affiliation: Department of Pediatrics, Takeda General Hospital, Aizu Wakamatsu-shi, Fukushima, Japan. yfuku@takeda.or.jp
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Fukuda
authors.forename: Nobuo
authors.initials: N
authors.lastname: Momoi
authors.forename: Masaki
authors.initials: M
authors.lastname: Mitomo
authors.forename: Yoshimichi
authors.initials: Y
authors.lastname: Aoyagi
authors.forename: Kisei
authors.initials: K
authors.lastname: Endo
authors.forename: Ayumi
authors.initials: A
authors.lastname: Matsumoto
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Hosoya
mesh_terms: D000465:Algorithms; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007223:Infant; D007275:Injections, Intravenous; D008168:Lung / Q000000981:diagnostic imaging*; D055420:Perfusion Imaging / Q000379:methods*; D011666:Pulmonary Valve Stenosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013668:Technetium Tc 99m Aggregated Albumin; D018785:Tricuspid Atresia / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*
chemical_list: D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin