Chu W F, Lin C J, Chen W S, Hung S C, Chiu C F, Wu T H, Guo W Y
From the Department of Radiology (W.F.C., C.J.L., S.C.H., C.F.C., W.Y.G.), Taipei Veterans General Hospital, Taipei, TaiwanSchool of Medicine (W.F.C., C.J.L., S.C.H., C.F.C., W.Y.G.).
Department of Biomedical Imaging and Radiological Sciences (W.S.C., T.H.W.), National Yang-Ming University, Taipei, Taiwan.
AJNR Am J Neuroradiol. 2014 Jun;35(6):1073-7. doi: 10.3174/ajnr.A3822. Epub 2013 Dec 26.
Parenchymal blood volume measurement by C-arm CT facilitates in-room peritherapeutic perfusion evaluation. However, the radiation dose remains a major concern. This study aimed to compare the radiation dose of parenchymal blood volume measurement using C-arm CT with that of conventional CTP using multidetector CT.
A biplane DSA equipped with C-arm CT and a Rando-Alderson phantom were used. Slab parenchymal blood volume (8-cm scanning range in a craniocaudal direction) and whole-brain parenchymal blood volume with identical scanning parameters, except for scanning ranges, were undertaken on DSA. Eighty thermoluminescent dosimeters were embedded into 22 organ sites of the phantom. We followed the guidelines of the International Commission on Radiation Protection number 103 to calculate the effective doses. For comparison, 8-cm CTP with the same phantom and thermoluminescent dosimeter distribution was performed on a multidetector CT. Two repeat dose experiments with the same scanning parameters and phantom and thermoluminescent dosimeter settings were conducted.
Brain-equivalent dose in slab parenchymal blood volume, whole-brain parenchymal blood volume, and CTP were 52.29 ± 35.31, 107.51 ± 31.20, and 163.55 ± 89.45 mSv, respectively. Variations in the measurement of an equivalent dose for the lens were highest in slab parenchymal blood volume (64.5%), followed by CTP (54.6%) and whole-brain parenchymal blood volume (29.0%). The effective doses of slab parenchymal blood volume, whole-brain parenchymal blood volume, and CTP were 0.87 ± 0.55, 3.91 ± 0.78, and 2.77 ± 1.59 mSv, respectively.
The dose measurement conducted in the current study was reliable and reproducible. The effective dose of slab parenchymal blood volume is about one-third that of CTP. With the advantages of on-site and immediate imaging availability and saving procedural time and patient transportation, slab parenchymal blood volume measurement using C-arm CT can be recommended for clinical application.
通过C臂CT测量实质血容量有助于在治疗室内进行治疗期间的灌注评估。然而，辐射剂量仍然是一个主要问题。本研究旨在比较使用C臂CT测量实质血容量与使用多排CT进行传统CT灌注的辐射剂量。
使用配备C臂CT的双平面数字减影血管造影（DSA）和Rando-Alderson体模。在DSA上进行了平板实质血容量（在头足方向上8厘米的扫描范围）和全脑实质血容量测量，除扫描范围外，扫描参数相同。将80个热释光剂量计嵌入体模的22个器官部位。我们遵循国际辐射防护委员会第103号指南来计算有效剂量。为了进行比较，在多排CT上对相同的体模和热释光剂量计分布进行了8厘米的CT灌注检查。进行了两次具有相同扫描参数、体模和热释光剂量计设置的重复剂量实验。
平板实质血容量、全脑实质血容量和CT灌注的脑等效剂量分别为52.29±35.31、107.51±31.20和163.55±89.45毫希沃特。平板实质血容量中晶状体等效剂量测量的变化最大（64.5%），其次是CT灌注（54.6%）和全脑实质血容量（29.0%）。平板实质血容量、全脑实质血容量和CT灌注的有效剂量分别为0.87±0.55、3.91±0.78和2.77±1.59毫希沃特。
本研究中进行的剂量测量是可靠且可重复的。平板实质血容量的有效剂量约为CT灌注的三分之一。鉴于具有现场即时成像、节省检查时间和患者转运等优点，推荐使用C臂CT测量平板实质血容量用于临床应用。
