Matsutani Hideyuki, Sano Tomonari, Kondo Takeshi, Fujimoto Shinichiro, Sekine Takako, Arai Takehiro, Morita Hitomi, Takase Shinichi
Department of Radiology, Takase Clinic, Japan.
Nihon Hoshasen Gijutsu Gakkai Zasshi. 2010 Dec 20;66(12):1548-54. doi: 10.6009/jjrt.66.1548.
A high radiation dose associated with 64 multidetector-row computed tomography (64-MDCT) is a major concern for physicians and patients alike. A new 320 row area detector computed tomography (ADCT) can obtain a view of the entire heart with one rotation (0.35 s) without requiring the helical method. As such, ADCT is expected to reduce the radiation dose. We studied image quality and radiation dose of ADCT compared to that of 64-MDCT in patients with a low heart rate (HR≤60).
Three hundred eighty-five consecutive patients underwent 64-MDCT and 379 patients, ADCT. Patients with an arrhythmia were excluded. Prospective ECG-gated helical scan with high HP (FlashScan) in 64 was used for MDCT and prospective ECG-gated conventional one beat scan, for 320-ADCT. Image quality was visually evaluated by an image quality score. Radiation dose was estimated by DLP (mGy・cm) for 64-MDCT and DLP.e (mGy・cm) for 320-ADCT.
Radiation dose of 320-ADCT (208±48 mGy・cm) was significantly (P<0.0001) lower than that of 64-MDCT (484±112 mGy・cm), and image quality score of 320-ADCT (3.0±0.2) was significantly (P=0.0011) higher than that of 64-MDCT (2.9±0.4). Scan time of 320-ADCT (1.4±0.1 s) was also significantly (P<0.0001) shorter than that of 64-MDCT (6.8±0.6 s).
320-ADCT can achieve not only a reduction in radiation dose but also a superior image quality and shortening of scan time compared to 64-MDCT.
64排多层螺旋计算机断层扫描(64-MDCT)所带来的高辐射剂量是医生和患者共同关注的主要问题。新型的320排面积探测器计算机断层扫描(ADCT)能够在一次旋转(0.35秒)内获取整个心脏的图像,无需采用螺旋扫描方法。因此,ADCT有望降低辐射剂量。我们研究了心率较低(HR≤60)的患者中,ADCT与64-MDCT相比的图像质量和辐射剂量。
385例连续患者接受了64-MDCT检查,379例患者接受了ADCT检查。排除心律失常患者。64-MDCT采用前瞻性心电图门控高螺距(FlashScan)螺旋扫描,320-ADCT采用前瞻性心电图门控常规单搏扫描。通过图像质量评分对图像质量进行视觉评估。64-MDCT的辐射剂量通过剂量长度乘积(DLP,mGy・cm)估算,320-ADCT的辐射剂量通过等效剂量长度乘积(DLP.e,mGy・cm)估算。
320-ADCT的辐射剂量(208±48 mGy・cm)显著低于64-MDCT(484±112 mGy・cm)(P<0.0001),320-ADCT的图像质量评分(3.0±0.2)显著高于64-MDCT(2.9±0.4)(P=0.0011)。320-ADCT的扫描时间(1.4±0.1秒)也显著短于64-MDCT(6.8±0.6秒)(P<0.0001)。
与64-MDCT相比,320-ADCT不仅能够降低辐射剂量,还能获得更高的图像质量并缩短扫描时间。