Department of Radiological Technology, Takase Clinic, Takasaki, 370-0036, Japan.
J Cardiol. 2009 Dec;54(3):441-51. doi: 10.1016/j.jjcc.2009.07.004. Epub 2009 Sep 2.
Since image quality obtained in the mid-diastolic [or slow filling (SF)] phase is generally superior to end-systolic image in coronary multidetector row computed tomography (MDCT), low heart rate (HR) comprises the most important factor for acquisition of high-quality images. However, despite HR <70 and optimum breath-hold, sometimes high quality images cannot be obtained in SF. We assessed the significance of PQ interval in acquisition of coronary MDCT.
Of 541 consecutive patients who underwent coronary MDCT, 7 patients with incomplete breath-hold, 62 HR ≥70, and 70 arrhythmias were excluded. The remaining 402 patients (M: 222, 66±11 years), including 38 with first-degree atrioventricular block (1° AVB, PQ >200 ms) were evaluated. RR and PQ were measured on electrocardiogram and systolic and SF phase with 4-chamber cine cardiac computed tomography. SF significantly (p<0.0001) correlated with RR (SF=-471+0.720RR, r=0.887) in all subjects. The SF of without 1° AVB (292±97 ms) was significantly (p<0.0147) longer than that of with 1° AVB (251±121 ms), although RR was not significantly different between the two groups. The SF/RR of without 1° AVB (27.2±6.1%) was also significantly (p<0.0001) higher than that of with 1° AVB (22.7±8.0%). The coefficient of correlation between (RR-PQ) and SF [r=0.915, p<0.0001, SF=-362+0.742(RR-PQ)] was significantly (p<0.034) higher than that of correlation between RR and SF in all subjects. The SF of rank A image quality was significantly longer than that of rank B (p<0.0001) or rank C (p=0.0042). In critical HR (60-69 bpm), the optimum phase was ES in 7/139 patients without 1° AVB, and SF in 3/13 patients with 1° AVB (chi(2), p<0.0416).
Since SF depends on (RR-PQ), if PQ is long in critical HR, it might be difficult to reconstruct high quality images in the SF phase.
由于在冠状动脉多层螺旋 CT（MDCT）中舒张中期[或缓慢充盈（SF）]获得的图像质量通常优于收缩末期，因此低心率（HR）是获得高质量图像的最重要因素。但是，尽管 HR<70 且最佳屏气，但有时仍无法在 SF 中获得高质量的图像。我们评估了 PQ 间期在冠状动脉 MDCT 采集过程中的意义。
在接受冠状动脉 MDCT 的 541 例连续患者中，排除了 7 例屏气不完全、62 例 HR≥70 和 70 例心律失常的患者。剩余 402 例患者（M：222 例，66±11 岁），包括 38 例一度房室传导阻滞（1° AVB，PQ>200ms）。RR 和 PQ 在心电图上以及四腔心脏 CT 电影上测量收缩期和 SF 期。SF 与 RR 呈显著负相关（SF=-471+0.720RR，r=0.887）（p<0.0001）。无 1° AVB 的 SF（292±97ms）明显长于有 1° AVB 的 SF（251±121ms）（p<0.0147），尽管两组的 RR 无明显差异。无 1° AVB 的 SF/RR（27.2±6.1%）也明显高于有 1° AVB 的 SF/RR（22.7±8.0%）（p<0.0001）。在所有患者中，（RR-PQ）与 SF 之间的相关系数[r=0.915，p<0.0001，SF=-362+0.742（RR-PQ）]明显高于 RR 与 SF 之间的相关系数。A 级图像质量的 SF 明显长于 B 级（p<0.0001）或 C 级（p=0.0042）。在临界 HR（60-69bpm）下，无 1° AVB 的 139 例患者中，最佳期为 ES，而有 1° AVB 的 13 例患者中最佳期为 SF（卡方，p<0.0416）。
由于 SF 取决于（RR-PQ），因此如果在临界 HR 中 PQ 较长，则可能难以在 SF 期重建高质量的图像。
