Department of Radiology B, University Hospital of Strasbourg-Hôpital Civil 1, place de l'hôpital, 67091 Strasbourg cedex, France.
Department of Radiology B, University Hospital of Strasbourg-Hôpital Civil 1, place de l'hôpital, 67091 Strasbourg cedex, France.
Diagn Interv Imaging. 2018 Oct;99(10):653-662. doi: 10.1016/j.diii.2018.05.009. Epub 2018 Jun 14.
To evaluate the best collimation used in wide volume (WV) mode to cover the abdomen in computed tomography (CT) urography in terms of radiation dose and image quality.
This study was performed on a 320×0.5mm detector row CT unit. The first part identified the lowest volume CT dose index (CTDIvol) by using the topograms data of 25 medium size patients (13 men and 12 women; mean age: 52±9 [SD] years; age range: 46-68 years) using different collimations on WV from 6cm to 16cm and the one of the helical mode for the same coverage length. The second part consisted of a clinical evaluation of this result including 45 medium size patients (32 men and 13 women; mean age: 68±14 [SD] years; age range: 45-72 years). The qualitative evaluation included several items based on a 5-point Likert scale.
The first part of the study indicated that a collimation of 10cm (200×0.5mm) in WV mode with 5 volumes had the lowest CTDIvol (2.78±0.35mGy; range: 2.35-3.21mGy) compared to helical mode (4.38±0.48mGy, range: 3.75-4.95mGy). In the second part, the mean radiation dose reduction by comparison with helical mode was 44.03%±0.36% (P<0.001) and 51.16%±1.22% (P<0.005) for CTDIvol and DLP, respectively.
Wide volume mode of the abdomen can be performed with a significant radiation dose reduction with a collimation of 10cm (200×0.5mm) and five volumes.
在 CT 尿路造影中，评估宽体积（WV）模式下覆盖腹部的最佳准直方式，从辐射剂量和图像质量两方面进行考量。
本研究在一台 320×0.5mm 探测器排 CT 机上进行。第一部分，使用不同准直器对 25 名中等体型患者（13 名男性和 12 名女性；平均年龄：52±9[标准差]岁；年龄范围：46-68 岁）的 WV 从 6cm 到 16cm 进行顶层扫描数据，并与相同覆盖长度的螺旋模式的 CT 剂量指数（CTDIvol）进行比较，确定最低的 CTDIvol。第二部分由对该结果的临床评估组成，共纳入 45 名中等体型患者（32 名男性和 13 名女性；平均年龄：68±14[标准差]岁；年龄范围：45-72 岁）。定性评估包括基于 5 分制的多项内容。
研究的第一部分表明，与螺旋模式相比，WV 模式下的 10cm（200×0.5mm）准直器具有 5 个容积时的 CTDIvol 最低（2.78±0.35mGy；范围：2.35-3.21mGy）。在第二部分中，与螺旋模式相比，CTDIvol 和 DLP 的平均辐射剂量降低分别为 44.03%±0.36%（P<0.001）和 51.16%±1.22%（P<0.005）。
使用 10cm（200×0.5mm）准直器和 5 个容积，可显著降低腹部 WV 模式的辐射剂量。
