Nagayama Yasunori, Tanoue Shota, Tsuji Akinori, Urata Joji, Furusawa Mitsuhiro, Oda Seitaro, Nakaura Takeshi, Utsunomiya Daisuke, Yoshida Eri, Yoshida Morikatsu, Kidoh Masafumi, Tateishi Machiko, Yamashita Yasuyuki
1 Department of Radiology, Kumamoto City Hospital , Kumamoto , Japan.
2 Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University , Kumamoto , Japan.
Br J Radiol. 2018 May;91(1085):20170632. doi: 10.1259/bjr.20170632. Epub 2018 Mar 2.
To evaluate the image quality, radiation dose, and renal safety of contrast medium (CM)-reduced abdominal-pelvic CT combining 80-kVp and sinogram-affirmed iterative reconstruction (SAFIRE) in patients with renal dysfunction for oncological assessment.
We included 45 patients with renal dysfunction (estimated glomerular filtration rate <45 ml per min per 1.73 m) who underwent reduced-CM abdominal-pelvic CT (360 mgI kg, 80-kVp, SAFIRE) for oncological assessment. Another 45 patients without renal dysfunction (estimated glomerular filtration rate >60 ml per lmin per 1.73 m) who underwent standard oncological abdominal-pelvic CT (600 mgI kg, 120-kVp, filtered-back projection) were included as controls. CT attenuation, image noise, and contrast-to-noise ratio (CNR) were compared. Two observers performed subjective image analysis on a 4-point scale. Size-specific dose estimate and renal function 1-3 months after CT were measured.
The size-specific dose estimate and iodine load of 80-kVp protocol were 32 and 41%,, respectively, lower than of 120-kVp protocol (p < 0.01). CT attenuation and contrast-to-noise ratio of parenchymal organs and vessels in 80-kVp images were significantly better than those of 120-kVp images (p < 0.05). There were no significant differences in quantitative or qualitative image noise or subjective overall quality (p > 0.05). No significant kidney injury associated with CM administration was observed.
80-kVp abdominal-pelvic CT with SAFIRE yields diagnostic image quality in oncology patients with renal dysfunction under substantially reduced iodine and radiation dose without renal safety concerns. Advances in knowledge: Using 80-kVp and SAFIRE allows for 40% iodine load and 32% radiation dose reduction for abdominal-pelvic CT without compromising image quality and renal function in oncology patients at risk of contrast-induced nephropathy.
评估在肾功能不全患者中，采用80千伏峰值（kVp）和正弦图确认迭代重建（SAFIRE）技术的低剂量对比剂腹部盆腔CT用于肿瘤评估时的图像质量、辐射剂量和肾脏安全性。
我们纳入了45例肾功能不全患者（估计肾小球滤过率<45毫升/每分钟/1.73平方米），这些患者接受了低剂量对比剂腹部盆腔CT（360毫克碘/千克，80 kVp，SAFIRE）以进行肿瘤评估。另外纳入45例肾功能正常患者（估计肾小球滤过率>60毫升/每分钟/1.73平方米）作为对照，他们接受了标准的肿瘤腹部盆腔CT（600毫克碘/千克，120 kVp，滤波反投影）。比较了CT衰减、图像噪声和对比噪声比（CNR）。两名观察者采用4分制进行主观图像分析。测量了CT后1至3个月的体型特异性剂量估计值和肾功能。
80 kVp方案的体型特异性剂量估计值和碘负荷分别比120 kVp方案低32%和41%（p<0.01）。80 kVp图像中实质器官和血管的CT衰减及对比噪声比显著优于120 kVp图像（p<0.05）。在定量或定性图像噪声或主观整体质量方面无显著差异（p>0.05）。未观察到与对比剂给药相关的显著肾损伤。
采用SAFIRE的80 kVp腹部盆腔CT在碘剂和辐射剂量大幅降低的情况下，可为肾功能不全的肿瘤患者提供诊断图像质量，且无肾脏安全性问题。知识进展：使用80 kVp和SAFIRE可使腹部盆腔CT的碘负荷降低40%，辐射剂量降低32%，同时不影响有对比剂肾病风险的肿瘤患者的图像质量和肾功能。
