PURPOSE To evaluate image quality and confidence for planning of periradicular infiltrations using virtually lowered tube currents and in-house developed iterative reconstruction (IR) for multidetector computed tomography (MDCT). METHODS A total of 20 patients (mean age 54.9 ± 13.1 years) underwent MDCT for planning purposes of periradicular infiltrations at the lumbosacral spine (120 kVp and 100 mAs). Planning scans were simulated as if they were performed at 50% (D50), 10% (D10), 5% (D5), and 1% (D1) of the tube current of original scanning. Image reconstruction was achieved with two levels of IR (A: similar in appearance to clinical reconstructions, B: 10 times stronger noise reduction). Qualitative image evaluation was performed by two readers (R1 and R2) considering overall image quality and artifacts, image contrast, determination of nerve root, and confidence for intervention planning (scoring: 1 high, 2 medium, and 3 low confidence). RESULTS Level A of IR was favorable regarding overall image quality, artifacts, image contrast, and nerve root depiction according to both readers, with preserved good to excellent scores down to D10 scans. The confidence for intervention planning was not significantly different (p > 0.05) between scans with tube currents virtually lowered down to 10% as compared to the original scans when using level A of IR (R1: 1.2 ± 0.4, R2: 1.1 ± 0.3). Inter-reader agreement for planning confidence was good to excellent (range of weighted Cohen's kappa: 0.62-1.00). CONCLUSION The use of MDCT for planning purposes of lumbosacral periradicular infiltrations may be possible with tube currents lowered down to 10% of standard dose (equal to 10 mAs) without limitations in planning confidence.

中文翻译：

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低剂量 MDCT 用于规划腰骶椎周围浸润的系统评估。

目的使用几乎降低的管电流和内部开发的多探测器计算机断层扫描 (MDCT) 迭代重建 (IR) 来评估图像质量和规划根周浸润的置信度。方法 共有 20 名患者（平均年龄 54.9 ± 13.1 岁）接受了 MDCT，以规划腰骶椎根周浸润（120 kVp 和 100 mAs）。计划扫描被模拟，就好像它们是在原始扫描管电流的 50% (D50)、10% (D10)、5% (D5) 和 1% (D1) 下执行的。图像重建是通过两个级别的 IR 实现的（A：外观与临床重建相似，B：降噪强度提高 10 倍）。考虑整体图像质量和伪影、图像对比度、确定神经根和干预计划的置信度（评分：1 高、2 中、3 低置信度）。结果 根据两位读者的意见，IR 的 A 级在整体图像质量、伪影、图像对比度和神经根描绘方面是有利的，在 D10 扫描时保持良好到优秀的分数。与使用 IR 级别 A 的原始扫描相比，管电流实际上降低至 10% 的扫描之间的干预计划置信度没有显着差异（p > 0.05）（R1：1.2 ± 0.4，R2：1.1 ± 0.3） . 计划信心的读者间一致性从好到极好（加权 Cohen's kappa 范围：0.62-1.00）。