Yagami K, Miyoshi T, Shigeyama S, Takai H, Tsukahara Y, Matsumoto K, Suzuki R, Yasuda N, Okada H, Suzuki S, Foley S J
Radiology Services, Gifu University Hospital, Gifu, Japan.
Graduate School of Health Sciences, Fujita Health University, Toyoake, Japan.
Radiat Prot Dosimetry. 2018 Oct 1;181(3):261-268. doi: 10.1093/rpd/ncy022.
The aim of this study was to evaluate the suitability of size specific dose estimates (SSDE) to estimate patient dose in Fast kVp switching dual energy CT. An anthropomorphic phantom (RAN-110) was repeatedly scanned (chest, abdomen and the pelvis) using a 64 detector row MDCT (Discovery CT750 HD, GE Healthcare, Milwaukee, WI, USA) with various CT parameters, including Fast kVp switching. Dosimetry was performed using thermo-luminescent dosimeters, positioned both superficially and within the phantom. SSDE was calculated for all slices of the anthropomorphic phantom using both the localiser and axial images. In Fast kVp switching, SSDE underestimated the measured absorbed dose for the chest/abdomen region ~35% at the maximum, but were in closer agreement for the pelvic region about within 10%. In single energy techniques, SSDE could not be applied in the estimation of organ doses, but in Fast kVp switching dual energy techniques, SSDE could be applied for anatomical regions with larger thicknesses.
本研究的目的是评估特定尺寸剂量估计值（SSDE）在快速千伏切换双能CT中估算患者剂量的适用性。使用64排探测器MDCT（Discovery CT750 HD，GE Healthcare，密尔沃基，威斯康星州，美国），采用包括快速千伏切换在内的各种CT参数，对一个仿真人体模型（RAN - 110）进行反复扫描（胸部、腹部和骨盆）。使用热释光剂量计进行剂量测定，剂量计放置在模型表面和内部。使用定位像和轴位像为仿真人体模型的所有层面计算SSDE。在快速千伏切换中，SSDE对胸部/腹部区域的测量吸收剂量最多低估约35%，但对骨盆区域的低估在10%左右，两者更为接近。在单能技术中，SSDE不能用于估算器官剂量，但在快速千伏切换双能技术中，SSDE可用于厚度较大的解剖区域。
