Widmann G, Fasser M, Schullian P, Zangerl A, Puelacher W, Kral F, Riechelmann H, Jaschke W, Bale R
Department of Radiology, Innsbruck Medical University, Austria.
Rofo. 2012 Feb;184(2):136-42. doi: 10.1055/s-0031-1281971. Epub 2012 Jan 13.
Reduction of the radiation exposure involved in image-guided craniofacial and skull base surgery is an important goal. The purpose was to evaluate the influence of low-dose protocols in modern multi-slice spiral computed tomography (MSCT) on target registration errors (TREs).
An anthropomorphic skull phantom with target markers at the craniofacial bone and the anterior skull base was scanned in Sensation Open (40-slice), LightSpeed VCT (64-slice) and Definition Flash (128-slice). Identical baseline protocols (BP) at 120 kV/100 mAs were compared to the following low-dose protocols (LD) in care dose/dose modulation: (LD-I) 100 kV/35ref. mAs, (LD-II) 80 kV/40 - 41ref. mAs, and (LD-III) 80 kV/15 - 17ref. mAs. CTDIvol and DLP were obtained. TREs using an optical navigation system were calculated for all scanners and protocols. Results were statistically analyzed in SPSS and compared for significant differences (p ≤ 0.05).
CTDIvol for the Sensation Open/LightSpeed VCT/Definition Flash showed: (BP) 22.24 /32.48 /14.32 mGy; (LD-I) 4.61 /3.52 /1.62 mGy; (LD-II) 3.15 /2.01 /0.87 mGy; and (LD-III) na/0.76 /0.76 mGy. Differences between the BfS (Bundesamt für Strahlenschutz) reference CTDIvol of 9 mGy and the lowest CTDIvol were approximately 3-fold for Sensation Open, and 12-fold for the LightSpeed VCT and Definition Flash. A total of 33 registrations and 297 TRE measurements were performed. In all MSCT scanners, the TREs did not significantly differ between the low-dose and the baseline protocols.
Low-dose protocols in modern MSCT provided substantial dose reductions without significant influence on TRE and should be strongly considered in image-guided surgery.
减少影像引导下颅面及颅底手术中的辐射暴露是一个重要目标。本研究旨在评估现代多层螺旋计算机断层扫描（MSCT）低剂量扫描方案对靶区配准误差（TRE）的影响。
使用一个在颅面骨和前颅底带有靶标标记的仿真人头骨模型，分别在Sensation Open（40层）、LightSpeed VCT（64层）和Definition Flash（128层）CT扫描仪上进行扫描。将120 kV/100 mAs的相同基线扫描方案（BP）与以下Care Dose/剂量调制低剂量扫描方案（LD）进行比较：（LD-I）100 kV/35参考mAs，（LD-II）80 kV/40 - 41参考mAs，以及（LD-III）80 kV/15 - 17参考mAs。记录容积CT剂量指数（CTDIvol）和剂量长度乘积（DLP）。使用光学导航系统计算所有扫描仪及扫描方案的TRE。结果在SPSS软件中进行统计学分析，并比较差异是否具有统计学意义（p≤0.05）。
Sensation Open/LightSpeed VCT/Definition Flash的CTDIvol结果显示：（BP）22.24/32.48/14.32 mGy；（LD-I）4.61/3.52/1.62 mGy；（LD-II）3.15/2.01/0.87 mGy；以及（LD-III）未给出/0.76/0.76 mGy。Sensation Open的CTDIvol与德国联邦辐射防护办公室（BfS）9 mGy的参考CTDIvol相比，最低CTDIvol约低3倍；LightSpeed VCT和Definition Flash则约低12倍。总共进行了33次配准和297次TRE测量。在所有MSCT扫描仪中，低剂量扫描方案与基线扫描方案之间的TRE无显著差异。
现代MSCT的低剂量扫描方案可大幅降低辐射剂量，且对TRE无显著影响，在影像引导手术中应予以充分考虑。
