Department of Advanced Imaging and Interventional Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Clin Radiol. 2019 Aug;74(8):650.e13-650.e18. doi: 10.1016/j.crad.2019.03.017. Epub 2019 Apr 20.
To compare perfusion computed tomography (CT) with reconstructed image from source data using low-dose contrast agent and conventional 320-row CT for the evaluation of renal tumours.
Twenty-eight patients underwent conventional CT (C-CT) and 26 patients underwent perfusion CT with low-dose (40 ml) contrast agent. Image noise, arterial visualisation, the sharpness of the corticomedullary junction (CMJ), and overall image quality were each assessed using a four-point scale. The tumour detection rate for lesions <4 cm (n=66) was also evaluated. Quantitative image parameters including image noise and the contrast-to-noise ratios (CNRs) of the renal artery and CMJ were measured. The volume CT dose index (CTDI), dose-length product (DLP), and size-specific dose estimate (SSDE) were also recorded.
Although the image noise of perfusion CT was higher than that of C-CT and the overall image quality of perfusion CT was lower than that of C-CT, the arterial visualisation score of perfusion CT was significantly higher than that of C-CT. The CMJ sharpness scores of the two techniques were equivalent. Sensitivity and positive predictive values were also equivalent with respect to tumour detection. The CNRs of both the left and right renal arteries were significantly higher on perfusion CT than on C-CT. The CTDI, DLP, and SSDE of perfusion CT were significantly lower than those of C-CT.
Perfusion CT using low-dose contrast agent preserved arterial visualisation and the tumour detection rate and achieved a low radiation dose despite image quality degradation and image noise.
比较低剂量对比剂的灌注 CT 与原始数据重建图像在评估肾肿瘤方面的效果。
28 例患者行常规 CT（C-CT），26 例患者行低剂量（40ml）对比剂灌注 CT。采用 4 分制评估图像噪声、动脉显影、皮质髓质交界（CMJ）锐利度和整体图像质量。还评估了用于评估 <4cm 病变（n=66）的肿瘤检出率。测量了图像噪声和肾动脉及 CMJ 的对比噪声比（CNR）等定量图像参数。还记录了容积 CT 剂量指数（CTDI）、剂量长度乘积（DLP）和体型特异性剂量估计（SSDE）。
尽管灌注 CT 的图像噪声高于 C-CT，且整体图像质量低于 C-CT，但灌注 CT 的动脉显影评分显著高于 C-CT。两种技术的 CMJ 锐利度评分相当。在肿瘤检出方面，灵敏度和阳性预测值也相当。左、右肾动脉的 CNRs 在灌注 CT 上均显著高于 C-CT。灌注 CT 的 CTDI、DLP 和 SSDE 均显著低于 C-CT。
尽管图像质量下降和噪声增加，但低剂量对比剂的灌注 CT 仍能保持动脉显影和肿瘤检出率，并实现低辐射剂量。
