Modified Blalock-Taussig shunt patency for pulmonary atresia: assessment with electron beam CT.
OBJECTIVE
The purpose of this work was to evaluate electron beam CT (EBCT) for the noninvasive assessment of modified Blalock-Taussig (BT) shunt patency in patients with pulmonary atresia.


METHODS
Five infants and children with pulmonary atresia and modified BT shunts underwent contrast-enhanced EBCT. Modified BT shunts from the subclavian artery to the pulmonary artery were performed to improve the pulmonary blood flow. Electrocardiogram (ECG)-triggered EBCT was obtained with a 100 ms exposure, 3 mm section thickness, and 2 mm table feed after intravenous administration of contrast material. Three-dimensional (3D) or maximum intensity projection (MIP) EBCT images were compared with conventional angiography. The visibility of modified BT shunts was graded and recorded with use of a four-point scale.


RESULTS
Satisfactory visualization was achieved in both 3D and MIP EBCT images to evaluate modified BT shunt patency.


CONCLUSIONS
Contrast-enhanced 3D or MIP EBCT imaging with ECG trigger may be used as an effective substitute to evaluate modified BT shunts with low radiation dose exposure.
Okada
Munemasa
M
Department of Radiology, Yamaguchi University School of Medicine, Japan. radokada@po.cc.yamaguchi-u.ac.jp
Matsunaga
Naofumi
N
Ito
Katsuyoshi
K
Takano
Katsuyuki
K
Fujiwara
Motoki
M
Ueda
Katsuhiko
K
D019917:Blood Vessel Prosthesis Implantation; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007223:Infant; D008297:Male; D011093:Polyethylene Terephthalates; D011138:Polytetrafluoroethylene; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D018633:Pulmonary Atresia / Q000000981:diagnostic imaging / Q000601:surgery*; D011856:Radiographic Image Enhancement; D012680:Sensitivity and Specificity; D013348:Subclavian Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed
D011093:Polyethylene Terephthalates; D011138:Polytetrafluoroethylene