Silov Güler, Boğa Fatih
Samsun Gazi State Hospital, Clinic of Nuclear Medicine, Samsun, Türkiye.
Mol Imaging Radionucl Ther. 2023 Oct 20;32(3):214-220. doi: 10.4274/mirt.galenos.2023.55707.
To investigate the amount of effective dose (ED) due to the computed tomography (CT) component of lung perfusion-single-photon emission computed tomography (Q-SPECT)/CT.
In this single-center retrospective study, imaging data were collected from the clinic database for the period 2016-2022. The 327 patients identified were aged between 20 and 94 years. Tube voltage, tube current, pitch, gantry rotation time, volume CT dose index, and dose-length product (DLP) were recorded. The DLP was then converted to an ED using the conversion factors. The comparison of the ED between two groups was performed using the Mann-Whitney U non-parametric test.
ED (mean ± standard deviation, mSv) was 1.20±0.70 for the pulmonary embolism (PE) (-) and 1.54±1.04 for the PE (+) cases (p<0.05). It was observed that there was a 28% increase in the ED for the PE (+) cases. In addition, each of the PE (-) and PE (+) cases was divided into two groups according to the use of the computed tomography dose reduction (CTDR): without CTDR protocol group (non-CTDR) and with CTDR protocol group (CTDR). For those groups, ED were obtained as 0.87±0.72 and 1.55±0.47 for PE (-) cases (p<0.05); 1.56±1.17 and 1.49±0.54 for PE (+) cases (p>0.05) correspondingly. For a deeper understanding, ED was calculated for all three groups formed with different tube voltage values applied for the non-CTDR and CTDR groups.There was a 42% decrease in the ED for group 1 PE (+) compared to group 2 PE (+) (1.21±0.28, 2.07±0.91, p<0.05) and there was a 41% decrease in the ED for group 1 PE (-) compared to group 2 PE (-) cases (1.17±0.32, 1.97±0.65, p<0.05).
It could be concluded that the effective DR protocol is the non-CTDR protocol for the PE (-) cases and the application of the tube voltage at the level of 100 kVp for the PE (+) cases.
研究肺灌注 - 单光子发射计算机断层扫描（Q - SPECT）/CT中计算机断层扫描（CT）部分所致的有效剂量（ED）量。
在这项单中心回顾性研究中，从2016年至2022年的临床数据库收集影像数据。确定的327例患者年龄在20至94岁之间。记录管电压、管电流、螺距、机架旋转时间、容积CT剂量指数和剂量长度乘积（DLP）。然后使用转换因子将DLP转换为ED。两组之间ED的比较采用曼 - 惠特尼U非参数检验。
肺栓塞（PE）（ - ）病例的ED（平均值±标准差，mSv）为1.20±0.70，PE（ + ）病例为1.54±1.04（p<0.05）。观察到PE（ + ）病例的ED增加了28%。此外，根据计算机断层扫描剂量降低（CTDR）的使用情况，将每个PE（ - ）和PE（ + ）病例分为两组：无CTDR协议组（非CTDR）和有CTDR协议组（CTDR）。对于这些组，PE（ - ）病例的ED分别为0.87±0.72和1.55±0.47（p<0.05）；PE（ + ）病例分别为1.56±1.17和1.49±0.54（p>0.05）。为了更深入理解，对非CTDR组和CTDR组应用不同管电压值形成的所有三组计算ED。与第2组PE（ + ）相比，第1组PE（ + ）的ED降低了42%（1.21±0.28，2.07±0.91，p<0.05），与第2组PE（ - ）病例相比，第1组PE（ - ）的ED降低了41%（1.17±0.32，1.97±0.65，p<0.05）。
可以得出结论，对于PE（ - ）病例，有效的剂量降低协议是非CTDR协议，对于PE（ + ）病例，管电压应用水平为100 kVp。
