辅助检查 对于所有疑似肾绞痛的非妊娠成人患者，应申请行紧急（就诊后 24 小时内）低剂量计算机体层成像平扫（non-contrast computed tomography, NCCT）。[15]National Institute for Health and Care Excellence. Renal and ureteric stones: assessment and management. January 2019 [internet publication].https://www.nice.org.uk/guidance/ng118
NCCT 的敏感性和特异性很高，因此是肾结石的首选影像学检查手段，一旦怀疑肾结石，就应尽快进行该项检查。 NCCT 可准确确定是否存在肾结石，同时确定结石的大小和位置；如果检测阴性，则可在很大程度上排除肾结石。
体重指数（BMI）≤30 kg/m² 的患者首选低剂量扫描（<4 mSv），因为这种影像学检查可在降低放射暴露量的同时，将敏感性和特异性保持在 90% 或以上。不建议对 BMI >30 kg/m² 的患者进行低剂量 CT，因为其对这一患者人群的敏感性和特异性较低。[33]Fulgham PF, Assimos DG, Pearle MS, et al. Clinical effectiveness protocols for imaging in the management of ureteral calculous disease: AUA Technology Assessment. J Urol. 2013 Apr;189(4):1203-13.http://www.jurology.com/article/S0022-5347%2812%2905259-7/fulltexthttp://www.ncbi.nlm.nih.gov/pubmed/23085059?tool=bestpractice.com 对所有罹患肾结石且需要干预的患者，无论 BMI 如何，根据体型进行调整并减少剂量的 CT 方案其敏感性显示可达 96%。[43]Moore CL, Daniels B, Ghita M, et al. Accuracy of reduced-dose computed tomography for ureteral stones in emergency department patients. Ann Emerg Med. 2015 Feb;65(2):189-98.e2.http://www.ncbi.nlm.nih.gov/pubmed/25441242?tool=bestpractice.com
照射剂量＜50 mGy 不会导致胎儿畸形或流产的风险增加，因此，为了帮助疑难病例的诊断，低剂量 CT (＜4 mGy) 可作为底线检查方案，在妊娠中后期使用。[31]Türk C, Neisius A, Petrik A, et al. European Association of Urology. Urolithiasis. 2020 [internet publication].https://uroweb.org/guideline/urolithiasis/[33]Fulgham PF, Assimos DG, Pearle MS, et al. Clinical effectiveness protocols for imaging in the management of ureteral calculous disease: AUA Technology Assessment. J Urol. 2013 Apr;189(4):1203-13.http://www.jurology.com/article/S0022-5347%2812%2905259-7/fulltexthttp://www.ncbi.nlm.nih.gov/pubmed/23085059?tool=bestpractice.com[39]ACOG Committee on Obstetric Practice. Committee opinion no. 723: Guidelines for diagnostic imaging during pregnancy and lactation. Obstet Gynecol. 2017 Oct;130(4):e210-6.https://www.acog.org/-/media/Committee-Opinions/Committee-on-Obstetric-Practice/co723.pdf?dmc=1&ts=20180127T0150226583http://www.ncbi.nlm.nih.gov/pubmed/28937575?tool=bestpractice.com[40]Valovska MI, Pais VM Jr. Contemporary best practice urolithiasis in pregnancy. Ther Adv Urol. 2018 Apr;10(4):127-38.https://www.doi.org/10.1177/1756287218754765http://www.ncbi.nlm.nih.gov/pubmed/29560029?tool=bestpractice.com
如果患者年龄小于 16 岁且超声检查后仍不能确诊，请考虑进行低剂量 NCCT。[15]National Institute for Health and Care Excellence. Renal and ureteric stones: assessment and management. January 2019 [internet publication].https://www.nice.org.uk/guidance/ng118[31]Türk C, Neisius A, Petrik A, et al. European Association of Urology. Urolithiasis. 2020 [internet publication].https://uroweb.org/guideline/urolithiasis/[33]Fulgham PF, Assimos DG, Pearle MS, et al. Clinical effectiveness protocols for imaging in the management of ureteral calculous disease: AUA Technology Assessment. J Urol. 2013 Apr;189(4):1203-13.http://www.jurology.com/article/S0022-5347%2812%2905259-7/fulltexthttp://www.ncbi.nlm.nih.gov/pubmed/23085059?tool=bestpractice.com
