期外収縮症例における冠動脈CTの検討: 64列MDCTと320列ADCTの比較

摘要

Background: Because coronary computed tomography angiography (CCTA) by 320-area detector CT (320-ADCT) can be obtained in a short time, the probability of meeting up with premature contraction (PC) during scanning may be lower in 320-ADCT compared to 64-MDCT. The purpose is to compare the probability of meeting up with PC, scanning time, and image quality in patients with PC between the 2 groups (320-ADCT vs 64-MDCT). Methods: We have never rejected any CCTA examination due to arrhythmias. The 320-ADCT was performed in 2424 consecutive patients to include 70 atrial fibrillations (Afibs) and 64-MDCT in 1905 consecutive patients to include 51 Afibs. After exclusion of the patients with Afibs, we studied the probability of meeting up with PC during scanning and we compared the scanning time, image quality, and reconstruction phase for patients with PC between the 2 groups. Results: The probability of meeting up with PC during scanning in 320-ADCT (2.0%) is significantly lower (P<0.0001) than 64-MDCT (5.6%). For patients with PC, scanning time in 320-ADCT (2.9±0.6 s) was significantly shorter (P<0.0001) than 64-MDCT (9.5±1.9 s) and image quality in 320-ADCT (2.9±0.3 points) was significantly higher (P<0.0001) than 64-MDCT (2.2±0.8 points). CCTA was reconstructed in mid-diastolic phase in 93% of patients with PC using the 320-ADCT with arrhythmia rejection system. Conclusion: The scanning time of 320-ADCT was 1/3 in comparison with that of 64-MDCT, and the probability of meeting up with PC during scanning in 320-ADCT was 1/3 in comparison with that in 64-MDCT.%冠動脈computed tomography（CT）は64列multidetector CT（MDCT）の普及によって比較的容易に高画質の画像が得られるようになり，冠動脈内腔狭窄ばかりではなくプラーク性状の評価も可能な検査法として認知されるようになった.64列MDCTの検出器幅は32～40mmと狭いため寝台移動と同時に得られた心電図情報から複数心拍の同一心位相データを体軸方向に積み重ねて心臓全体の画像を構築している．そのため不整脈例で高画質な画像を得ることは比較的困難であった．