Dual Source CT를 이용한 폐정맥 검사시 전향적 심전도 동조화 기법의 유용성 평가

The Usefulness of Prospective ECG gating at Pulmonary Vein CT of Using Dual Source CT

Purpose It’s necessary that 3-D anatomy is described for successful RFCA of atrial fibrillation before the therapy. But there was a issue increasing patient dose of using retrospective ECG gating in heart study. This research has compared retrospective ECG gating with prospective ECG gating and estimated the usefulness of prospective ECG gating in pulmonary vein CT. Materials and methods We analyzed the 182 patients who had examined pulmonary vein CT before and behind RFA for aortal fibrillation from august 2007 to January 2009. We used dual source CT; Somatom Definition(Erlangen, Germany, 2006)equipment, and spiral and sequential scanned, Spiral scan parameters; 100kV (BMI < 25 kg/m2) or 120kV (BMI > 25 kg/m2), using Care dose 4D of dose modulation and quality reference mAs; spiral - 320mAs/rot, sequential - 320 mAs, scan time multi 0.38, common parameters; 0.33sec tube rotation time, scan time multi 0.38, 0.6mm collimation, slice thickness, increment scan range; from pulmonary upper margin to hearty base, contrast medium volume; (scan time* 4cc)+35cc, 4cc/sec injection following (scan time*4cc)+35cc add injection. Retrospective ECG gating was applied to 106 patients and prospective ECG gating was applied to 76 patients. Two radiologists checked up stair-step artifact and analyzed it. We estimated dose with DLP. Results Both retrospective ECG gating and prospective ECG gating has have excellent image in regular heart rate. But image of prospective gating was superior to retrospective ECG gating in case of arrhythmia patients. Average dose of prospective ECG gating 0.4 times as high as retrospective ECG gating and it is 0.29 times in case of arrhythmia patients. Conclusion Pulmonary vein CT image is useful for planning RFCA. In pulmonary vein CT, prospective ECG gating is better than retrospective ECG gating to decrease patient dose especially arrhythmia patients case.