摘要

PURPOSE:To assess radiation dose reduction for abdominal computed tomography (CT) examinations with adaptive statistical iterative reconstruction (ASIR) technique.
MATERIALS AND METHODS:With institutional review board approval, retrospective review of weight adapted abdominal CT exams were performed in 156 consecutive patients with ASIR and in 66 patients with filtered back projection (FBP) on a 64-slice MDCT. Patients were categorized into 3 groups of or=91 kg (n = 80) for weight-based adjustment of automatic exposure control technique. Remaining scan parameters were held constant at 1.375:1 pitch, 120 kVp, 55 mm table feed per rotation, 5 mm section thickness. Two radiologists reviewed all CT examinations for image noise and diagnostic acceptability. CT dose index volume, and dose length product were recorded. Image noise and transverse abdominal diameter were measured in all patients. Data were analyzed using analysis of variance.
RESULTS:ASIR allowed for an overall average decrease of 25.1% in CT dose index volume compared with the FBP technique (ASIR, 11.9 +/- 3.6 mGy; FBP, 15.9 +/- 4.3 mGy) (P < 0.0001). In each of the 3 weight categories, CT examinations reconstructed with ASIR technique were associated with significantly lower radiation dose compared with FBP technique (P < 0.0001). There was also significantly less objective image noise with ASIR (6.9 +/- 2.2) than with FBP (9.5 +/- 2.0) (P < 0.0001). For the subjective analysis, all ASIR and FBP reconstructed abdominal CTs had optimal or less noise. However, 9% of FBP and 3.8% of ASIR reconstructed CT examinations were diagnostically unacceptable because of the presence of artifacts. Use of ASIR reconstruction kernel results in a blotchy pixilated appearance in 39% of CT sans which however, was mild and did not affect the diagnostic acceptability of images. The critical reproduction of visually sharp anatomic structures was preserved in all but one ASIR 40% reconstructed CT examination.
CONCLUSION:ASIR technique allows radiation dose reduction for abdominal CT examinations whereas improving image noise compared with the FBP technique.

译文

目的: 用自适应统计迭代重建 (ASIR) 技术评估腹部计算机断层扫描 (CT) 检查的辐射剂量减少。
材料和方法: 经机构审查委员会批准,对 156 名连续 ASIR 患者和 66 名过滤反投影 (FBP) 患者进行了重量适应性腹部 ct检查的回顾性审查在 64 层 MDCT 上。患者被分为 3 组 or = 91千克 (n = 80),以体重为基础调整自动暴露控制技术。剩余的扫描参数保持恒定在 1.375: 1 间距,120 kVp,每次旋转 55毫米工作台进给量,5毫米截面厚度。两位放射科医生审查了所有 ct检查的图像噪声和诊断可接受性。记录 CT 剂量指数体积和剂量长度乘积。所有患者均测量图像噪声和腹部横径。数据采用方差分析进行分析。
结果: 与 FBP 技术相比,ASIR 允许 CT 剂量指数体积总体平均下降 25.1% (ASIR,11.9/-3.6 mGy; FBP,15.9/-4.3 mGy) (P <0.0001)。在 3 个重量类别中,与 FBP 技术相比,用 ASIR 技术重建的 ct检查与显著较低的辐射剂量相关 (P & lt; 0.0001)。ASIR (6.9/-2.2) 的客观图像噪声也明显少于 FBP (9.5/-2.0) (P & lt; 0.0001)。对于主观分析,所有 ASIR 和 FBP 重建的腹部 CTs 都有最佳或较小的噪声。然而,由于伪影的存在,9% 的 FBP 和 3.8% 的 ASIR 重建 ct检查在诊断上是不可接受的。ASIR 重建核的使用导致 39% 的 CT 无斑点像素化的出现,然而,这是温和的,不影响图像的诊断可接受性。除一次 ASIR 40% 的重建 ct检查外,所有重建 ct检查都保留了视觉清晰解剖结构的关键再现。
结论: 与 FBP 技术相比,ASIR 技术可以减少腹部 ct检查的辐射剂量,同时改善图像噪声。

abdominal CT

消化 腹腔脏器疾病检查 诊断方式
概述  :  

进行腹部CT检查的目的是为了了解腹腔脏器有没有感染性疾病,如:炎症、结核、脓肿等;有没有占位,如良、恶性肿瘤,转移性肿瘤等;有没有畸形、结石、梗阻、穿孔、积液等。 正常CT表现CT图像为腹部某一横断图像,须根据各脏器的解剖部位进行扫描。不同脏器的正常CT表现如下:肝脏:CT可显示肝脏轮廓、大小、密度和内部结构。正常肝脏密度均匀,CT值为40-70H,比脾脏高。不同层面上,所显示的肝脏各叶、段的大小、形状有所不同。如肝门以层,可显示“H”形低密度带状影。右纵裂为胆囊窝,左纵裂为肝镰状

abdominal 英 /æbˈdɒmɪnl/  美 /æbˈdɑːmɪnl/

释义   adj. 腹部的

例句   Objective: To discuss the clinical value of sebaceous indicator-effect in abdominal CT. 目的:探讨皮脂腺指标效应在腹部CT检查中的临床价值。


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