Tschauner Sebastian, Marterer Robert, Nagy Eszter, Apfaltrer Georg, Riccabona Michael, Singer Georg, Stücklschweiger Georg, Guss Helmuth, Sorantin Erich
Division of Pediatric Radiology, Department of Radiology, Medical University of Graz, Graz, Austria.
Division of General Pediatric and Adolescence Surgery, Medical University of Graz, Graz, Austria.
PLoS One. 2017 Jun 1;12(6):e0178747. doi: 10.1371/journal.pone.0178747. eCollection 2017.
To evaluate and compare surface doses of a cone beam computed tomography (CBCT) and a multidetector computed tomography (MDCT) device in pediatric ankle and wrist phantoms.
Thermoluminescent dosimeters (TLD) were used to measure and compare surface doses between CBCT and MDCT in a left ankle and a right wrist pediatric phantom. In both modalities adapted pediatric dose protocols were utilized to achieve realistic imaging conditions. All measurements were repeated three times to prove test-retest reliability. Additionally, objective and subjective image quality parameters were assessed.
Average surface doses were 3.8 ±2.1 mGy for the ankle, and 2.2 ±1.3 mGy for the wrist in CBCT. The corresponding surface doses in optimized MDCT were 4.5 ±1.3 mGy for the ankle, and 3.4 ±0.7 mGy for the wrist. Overall, mean surface dose was significantly lower in CBCT (3.0 ±1.9 mGy vs. 3.9 ±1.2 mGy, p<0.001). Subjectively rated general image quality was not significantly different between the study protocols (p = 0.421), whereas objectively measured image quality parameters were in favor of CBCT (p<0.001).
Adapted extremity CBCT imaging protocols have the potential to fall below optimized pediatric ankle and wrist MDCT doses at comparable image qualities. These possible dose savings warrant further development and research in pediatric extremity CBCT applications.
评估并比较锥形束计算机断层扫描（CBCT）和多排探测器计算机断层扫描（MDCT）设备在儿童踝关节和腕关节模型中的表面剂量。
使用热释光剂量计（TLD）测量并比较CBCT和MDCT在儿童左踝关节和右腕关节模型中的表面剂量。在两种模式下均采用适合儿童的剂量方案以实现逼真的成像条件。所有测量均重复三次以证明重测可靠性。此外，还评估了客观和主观图像质量参数。
CBCT中踝关节的平均表面剂量为3.8±2.1 mGy，腕关节为2.2±1.3 mGy。优化后的MDCT中踝关节和腕关节的相应表面剂量分别为4.5±1.3 mGy和3.4±0.7 mGy。总体而言，CBCT的平均表面剂量显著更低（3.0±1.9 mGy对3.9±1.2 mGy，p<0.001）。研究方案之间主观评定的总体图像质量无显著差异（p = 0.421），而客观测量的图像质量参数更有利于CBCT（p<0.001）。
在图像质量相当的情况下，适合四肢的CBCT成像方案有可能低于优化后的儿童踝关节和腕关节MDCT剂量。这些可能的剂量节省值得在儿童四肢CBCT应用中进一步开发和研究。
