Padole Atul, Sainani Nisha, Lira Diego, Khawaja Ranish Deedar Ali, Pourjabbar Sarvenaz, Lo Gullo Roberto, Otrakji Alexi, Kalra Mannudeep K
Atul Padole, Nisha Sainani, Diego Lira, Ranish Deedar Ali Khawaja, Sarvenaz Pourjabbar, Roberto Lo Gullo, Alexi Otrakji, Mannudeep K Kalra, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
World J Radiol. 2016 Jun 28;8(6):618-27. doi: 10.4329/wjr.v8.i6.618.
To assess diagnostic image quality of reduced dose (RD) abdominal computed tomography (CT) with 9 iterative reconstruction techniques (IRTs) from 4 different vendors to the standard of care (SD) CT.
In an Institutional Review Board approved study, 66 patients (mean age 60 ± 13 years, 44 men, and 22 women) undergoing routine abdomen CT on multi-detector CT (MDCT) scanners from vendors A, B, and C (≥ 64 row CT scanners) (22 patients each) gave written informed consent for acquisition of an additional RD CT series. Sinogram data of RD CT was reconstructed with two vendor-specific and a vendor-neutral IRTs (A-1, A-2, A-3; B-1, B-2, B-3; and C-1, C-2, C-3) and SD CT series with filtered back projection. Subjective image evaluation was performed by two radiologists for each SD and RD CT series blinded and independently. All RD CT series (198) were assessed first followed by SD CT series (66). Objective image noise was measured for SD and RD CT series. Data were analyzed by Wilcoxon signed rank, kappa, and analysis of variance tests.
There were 13/50, 18/57 and 9/40 missed lesions (size 2-7 mm) on RD CT for vendor A, B, and C, respectively. Missed lesions includes liver cysts, kidney cysts and stone, gall stone, fatty liver, and pancreatitis. There were also 5, 4, and 4 pseudo lesions (size 2-3 mm) on RD CT for vendor A, B, and C, respectively. Lesions conspicuity was sufficient for clinical diagnostic performance for 6/24 (RD-A-1), 10/24 (RD-A-2), and 7/24 (RD-A-3) lesions for vendor A; 5/26 (RD-B-1), 6/26 (RD-B-2), and 7/26 (RD-B-3) lesions for vendor B; and 4/20 (RD-C-1) 6/20 (RD-C-2), and 10/20 (RD-C-3) lesions for vendor C (P = 0.9). Mean objective image noise in liver was significantly lower for RD A-1 compared to both RD A-2 and RD A-3 images (P < 0.001). Similarly, mean objective image noise lower for RD B-2 (compared to RD B-1, RD B-3) and RD C-3 (compared to RD C-1 and C-2) (P = 0.016).
Regardless of IRTs and MDCT vendors, abdominal CT acquired at mean CT dose index volume 1.3 mGy is not sufficient to retain clinical diagnostic performance.
评估采用4家不同供应商的9种迭代重建技术（IRT）的低剂量（RD）腹部计算机断层扫描（CT）与标准剂量（SD）CT相比的诊断图像质量。
在一项经机构审查委员会批准的研究中，66例患者（平均年龄60±13岁，44例男性，22例女性）在供应商A、B和C的多排CT（MDCT）扫描仪（≥64排CT扫描仪）上接受常规腹部CT检查（各22例患者），并书面知情同意获取额外的RD CT系列。RD CT的正弦图数据采用两种供应商特定的和一种供应商中立的IRT（A-1、A-2、A-3；B-1、B-2、B-3；以及C-1、C-2、C-3）进行重建，SD CT系列采用滤波反投影重建。由两名放射科医生对每个SD和RD CT系列进行盲法独立主观图像评估。首先评估所有RD CT系列（198个），然后评估SD CT系列（66个）。测量SD和RD CT系列的客观图像噪声。数据采用Wilcoxon符号秩检验、kappa检验和方差分析进行分析。
供应商A、B和C的RD CT上分别有13/50、18/57和9/40个漏诊病变（大小为2-7mm）。漏诊病变包括肝囊肿、肾囊肿和结石、胆结石、脂肪肝和胰腺炎。供应商A、B和C的RD CT上分别还有5个、4个和4个假病变（大小为2-3mm）。对于供应商A的病变，6/24（RD-A-1）、10/24（RD-A-2）和7/24（RD-A-3）的病变清晰度足以满足临床诊断性能；对于供应商B的病变，5/26（RD-B-1）、6/26（RD-B-2）和7/26（RD-B-3）；对于供应商C的病变，4/20（RD-C-1）、6/20（RD-C-2）和10/20（RD-C-3）（P = 0.9）。与RD A-2和RD A-3图像相比，RD A-1肝脏中的平均客观图像噪声显著更低（P < 0.001）。同样，RD B-2（与RD B-1、RD B-3相比）和RD C-3（与RD C-1和C-2相比）的平均客观图像噪声更低（P = 0.016）。
无论IRT和MDCT供应商如何，平均CT剂量指数体积为1.3 mGy时采集的腹部CT不足以保持临床诊断性能。
