Sano Tomonari, Matsutani Hideyuki, Kondo Takeshi, Fujimoto Shinichiro, Sekine Takako, Arai Takehiro, Morita Hitomi, Takase Shinichi
Department of Radiological Technology, Takase Clinic.
Nihon Hoshasen Gijutsu Gakkai Zasshi. 2011;67(7):765-71. doi: 10.6009/jjrt.67.765.
The purpose of this study is to elucidate the relationship among RR interval (RR), the optimal reconstruction phase, and adequate temporal resolution (TR) to obtain coronary CT angiography images of acceptable quality using 64-MDCT (Aquilion 64) of end-systolic reconstruction in 407 patients with high heart rates. Image quality was classified into 3 groups [rank A (excellent): 161, rank B (acceptable): 207, and rank C (unacceptable): 39 patients]. The optimal absolute phase (OAP) significantly correlated with RR [OAP (ms)=119-0.286RR (ms), r=0.832, p<0.0001], and the optimal relative phase (ORP) also significantly correlated with RR [ORP (%)=62-0.023RR (ms), r=0.656, p<0.0001], and the correlation coefficient of OAP was significantly (p<0.0001) higher than that of ORP. The OAP range (±2SD) in which it is highly possible to get a static image was from [119-0.286RR (ms)-46] to [119-0.286RR (ms)+46]. The TR was significantly different among ranks A (97 ± 22 ms), B (111 ± 31 ms) and C (135 ± 34 ms). The TR significantly correlated with RR in ranks A (TR=-16+0.149RR, r=0.767, p<0.0001), B (TR=-15+0.166RR, r=0.646, p<0.0001), and C (TR=52+0.117RR, r=0.425, p=0.0069). Rank C was distinguished from ranks A or B by linear discriminate analysis (TR=-46+0.21RR), and the discriminate rate was 82.6%. In conclusion, both the OAP and adequate TR depend on RR, and the OAP range (±2SD) can be calculated using the formula [119-0.286RR (ms)-46] to [119-0.286RR (ms)+46], and an adequate TR value would be less than (-46+0.21RR).
本研究旨在阐明RR间期（RR）、最佳重建期与足够的时间分辨率（TR）之间的关系，以便使用64排多层螺旋CT（Aquilion 64）对407例心率较高的患者进行收缩末期重建，从而获得质量可接受的冠状动脉CT血管造影图像。图像质量分为3组[A级（优秀）：161例，B级（可接受）：207例，C级（不可接受）：39例]。最佳绝对期（OAP）与RR显著相关[OAP（毫秒）=119 - 0.286RR（毫秒），r = 0.832，p < 0.0001]，最佳相对期（ORP）也与RR显著相关[ORP（%）=62 - 0.023RR（毫秒），r = 0.656，p < 0.0001]，且OAP的相关系数显著高于ORP（p < 0.0001）。获得静态图像可能性较高的OAP范围（±2标准差）为[119 - 0.286RR（毫秒）- 46]至[119 - 0.286RR（毫秒）+ 46]。TR在A级（97±22毫秒）、B级（111±31毫秒）和C级（135±34毫秒）之间存在显著差异。在A级（TR = -16 + 0.149RR，r = 0.767，p < 0.0001）、B级（TR = -15 + 0.166RR，r = 0.646，p < 0.0001）和C级（TR = 52 + 0.117RR，r = 0.425，p = 0.0069）中，TR与RR均显著相关。通过线性判别分析（TR = -46 + 0.21RR）可将C级与A级或B级区分开来，判别率为82.6%。总之，OAP和足够的TR均取决于RR，OAP范围（±2标准差）可使用公式[119 - 0.286RR（毫秒）- 46]至[119 - 0.286RR（毫秒）+ 46]计算得出，足够的TR值应小于（-46 + 0.21RR）。
