New York Urological Associates, New York, New York 10021, USA.
J Endourol. 2012 Sep;26(9):1242-6. doi: 10.1089/end.2012.0130. Epub 2012 Jun 27.
Noncontrast abdominal/pelvic CT is the current imaging standard for patients who present with acute urinary colic. Conventional CT, however, exposes the patient to significant amounts of ionizing radiation, which is cumulative when additional CTs are used to monitor stone migration, outcomes, etc. We sought to maintain diagnostic adequacy while decreasing our patients' radiation exposure from CT by using a reduced tube current, an abbreviated scanning area, and the use of coronal reformatted images.
Between March 3, 2011 and October 31, 2011, 101 consecutive adult patients with suspected urinary colic were evaluated with a "low" dose CT. If the suspected calculus(i) was not seen, the patient underwent immediate conventional CT imaging customized to their body habitus. Radiation exposure for each patient was calculated using an established formula of dose length product and scan length. The effective total radiation dose was measured in millisieverts (mSv).
Overall, 84 patients had an upper tract calculus(i) consistent with the clinical suspicion. Of these, 76 (90%) were adequately imaged with low dose and 8 (10%) with conventional noncontrast CTs. The mean effective radiation dose in the 76 low dose stone-positive CTs was 2.14 mSV (median 2.10 mSv). This was almost seven-fold lower than the mean conventional stone-positive CT dose of 14.5 mSv (median 13.1 mSv).
Low dose noncontrast CT provided adequate imaging to guide optimal urologic management in the majority of our patients. This modality offered a significantly lower ionizing radiation dose and should be considered in patients who present with acute urinary colic.
对于出现急性尿路绞痛的患者，非增强腹部/盆腔 CT 是目前的影像学标准。然而，常规 CT 会使患者暴露在大量的电离辐射下，如果为了监测结石移动、结果等需要进行额外的 CT 检查，辐射量就会累积。我们试图在保持诊断充分性的同时，通过使用降低的管电流、缩短扫描范围和使用冠状位重建图像来降低患者 CT 辐射暴露。
在 2011 年 3 月 3 日至 2011 年 10 月 31 日期间，101 例疑似尿路绞痛的成年患者接受了“低剂量” CT 检查。如果未发现可疑结石(i)，则根据患者的体型立即进行定制的常规 CT 成像。每位患者的辐射暴露量均通过剂量长度乘积和扫描长度的既定公式进行计算。有效总辐射剂量以毫西弗(mSv)测量。
总体而言，84 例患者的上尿路结石(i)与临床怀疑相符。在这些患者中，76 例（90%）低剂量 CT 成像充分，8 例（10%）常规非增强 CT 成像充分。76 例低剂量结石阳性 CT 的平均有效辐射剂量为 2.14 mSv（中位数 2.10 mSv）。这比平均常规结石阳性 CT 剂量 14.5 mSv（中位数 13.1 mSv）低近 7 倍。
低剂量非增强 CT 为大多数患者提供了充分的成像，以指导最佳泌尿科治疗。这种方法的电离辐射剂量显著降低，对于出现急性尿路绞痛的患者应予以考虑。
