From the Department of Radiology (M.D.M., P.Y.S.), The Permanente Medical Group, Kaiser Permanente Medical Center, Santa Clara, Santa Clara, California
Department of Radiology and Biomedical Imaging (M.D.M.), University of California, San Francisco, San Francisco, California.
AJNR Am J Neuroradiol. 2023 Mar;44(3):341-346. doi: 10.3174/ajnr.A7784. Epub 2023 Feb 2.
Dynamic CT myelography can identify spinal CSF leaks secondary to dural tears (type 1) and ruptured meningeal diverticula (type 2), but the radiation can be high secondary to multiple successive acquisitions. The purpose of this article is to discuss the procedural approach of a modified dynamic CT myelography technique with single scan acquisitions, reduced contrast volume, and condensed scan coverage and compare its radiation dose with that in traditional dynamic CT myelography.
Retrospective review was performed for patients with spontaneous CSF leaks showing extradural collections on spine MR imaging who underwent traditional and modified dynamic CT myelography. The radiation doses between the 2 cohorts were compared.
Thirty-seven patients (25 women, 12 men) had a type 1 or 2 CSF leak on dynamic CT myelography. Thirty-one patients had a type 1 CSF leak, and 6 patients had type 2 leaks. The traditional dynamic CT myelography was performed in 25 patients, and the average number of acquisitions per dynamic CT myelography was 3.6. The mean total effective dose per dynamic CT myelography was 31.3 mSv (range, 11.3-68.4 mSv). The modified dynamic CT myelography was performed in 12 patients, and the average number of acquisitions was 2.8. The mean total effective dose per dynamic CT myelography was 15.1 mSv (range, 4.8-24.6 mSv). The effective dose and dose-length product between the cohorts were statistically significant ( < .0001 and .01, respectively).
Modified dynamic CT myelography performed with single scan acquisitions, smaller volume of contrast, and reduced scan coverage can reduce the radiation dose for type 1 and 2 CSF leak detection.
动态 CT 脊髓造影术可识别硬脊膜撕裂引起的脊髓 CSF 漏（1 型）和脑膜憩室破裂（2 型），但由于多次连续采集，辐射量可能会很高。本文旨在讨论一种改良的动态 CT 脊髓造影技术，该技术采用单次扫描采集、减少对比剂体积和缩短扫描范围，并比较其与传统动态 CT 脊髓造影的辐射剂量。
对 MRI 显示硬膜外积液的自发性 CSF 漏患者进行回顾性分析，这些患者行传统和改良动态 CT 脊髓造影检查。比较两组之间的辐射剂量。
37 例（25 例女性，12 例男性）患者在动态 CT 脊髓造影中显示 1 型或 2 型 CSF 漏。25 例患者行传统动态 CT 脊髓造影，平均每例动态 CT 脊髓造影采集次数为 3.6 次。平均总有效剂量为 31.3 mSv（范围为 11.3-68.4 mSv）。12 例患者行改良动态 CT 脊髓造影，平均采集次数为 2.8 次。平均总有效剂量为 15.1 mSv（范围为 4.8-24.6 mSv）。两组间的有效剂量和剂量长度乘积差异均有统计学意义（均 P<.0001 和 P<.01）。
采用单次扫描采集、较小的对比剂体积和缩短的扫描范围进行改良的动态 CT 脊髓造影术，可以降低 1 型和 2 型 CSF 漏检测的辐射剂量。
