Juresic Ewa, Liney Gary P, Rai Robba, Descalar Joseph, Lee Mark, Wong Karen, Moses Daniel, Veera Jacqueline, Holloway Lois
Liverpool and Macarthur Cancer Therapy Centres, Liverpool Hospital, Liverpool, New South Wales, Australia.
South Western Clinical School, School of Medicine, University of New South Wales, Liverpool, New South Wales, Australia.
J Med Radiat Sci. 2018 Mar;65(1):22-30. doi: 10.1002/jmrs.266.
A magnetic resonance (MR) scanner for radiotherapy treatment simulation was commissioned in our department in June 2013. Practical set up and MR image quality trade-offs using a variety of patient positions and immobilisation devices routinely used in the treatment planning of rectal cancer patients were considered. The study also aimed to investigate the MR compatibility of the device materials with a focus on temperature changes during routine clinical examinations.
Ten volunteers were scanned: (1) Prone on a Civco Contoura Bellyboard (BBB), (2) Prone on a Civco MR Series Bellyboard (WBB), (3) Prone with no bellyboard and (4) Supine. All scans were performed with a T weighted (T -w) turbo spin echo (TSE) sequence. Images were scored by five assessors for: (1) ease of identifying specific organs, (2) overall image quality and (3) signal to noise ratio (SNR). Temperature changes were measured for each volunteer in each position.
Both expert scores and SNR analysis demonstrated that images obtained in the supine position allowed for easier and clearer delineation of the organs. Image factors such as artefacts and noise, along with the overall image quality, also performed better in the supine position. The carbon fibre bellyboard did not demonstrate significant heating during scanning with the T -w TSE transverse sequence.
A supine position was determined to be superior to the other positions in a majority of comparisons. The volunteers did not experience any increased temperature changes during scanning on the bellyboard in comparison to the other positions.
2013年6月，一台用于放射治疗模拟的磁共振（MR）扫描仪在我们科室投入使用。我们考虑了使用直肠癌患者治疗计划中常规采用的各种患者体位和固定装置进行实际设置以及MR图像质量的权衡。该研究还旨在调查设备材料的MR兼容性，重点关注常规临床检查期间的温度变化。
对10名志愿者进行扫描：（1）俯卧在Civco Contoura腹托板（BBB）上，（2）俯卧在Civco MR系列腹托板（WBB）上，（3）俯卧不使用腹托板，（4）仰卧。所有扫描均采用T加权（T -w）快速自旋回波（TSE）序列进行。由五名评估人员对图像进行评分：（1）识别特定器官的难易程度，（2）整体图像质量，（3）信噪比（SNR）。测量了每位志愿者在每个体位的温度变化。
专家评分和SNR分析均表明，仰卧位获得的图像能更轻松、清晰地勾勒出器官轮廓。诸如伪影和噪声等图像因素以及整体图像质量在仰卧位时也表现更佳。使用T -w TSE横向序列扫描时，碳纤维腹托板未显示出明显发热。
在大多数比较中，仰卧位被确定优于其他体位。与其他体位相比，志愿者在腹托板上扫描时未出现任何温度升高变化。
