Low-Tube-Voltage, High-Tube-Current Multidetector Abdominal CT: Improved Image Quality and Decreased Radiation Dose with Adaptive Statistical Iterative Reconstruction Algorithm-Initial Clinical Experience
Low-Tube-Voltage, High-Tube-Current Multidetector Abdominal CT: Improved Image Quality and Decreased Radiation Dose with Adaptive Statistical Iterative Reconstruction Algorithm-Initial Clinical Experience
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DOI：
10.1148/radiol.09090094
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发表时间：
2010-01-01
期刊：
影响因子：
19.7
通讯作者：
Samei, Ehsan
中科院分区：
文献类型：
--
作者：
Marin, Daniele;Nelson, Rendon C.;Samei, Ehsan
目的：探讨自适应统计迭代重建（ASIR）算法是否能改善肝动脉晚期低管电压（80 kvp）、高管电流（675 ma）多检测器腹部计算机断层扫描（CT）的图像质量。材料和方法：本前瞻性单中心hipaa研究已获机构审查委员会批准。获得患者知情同意。10例已知或疑似肝高血管性肿瘤患者（男6例，女4例，平均年龄63岁，年龄51 ~ 77岁）行双能64层多层CT检查。在肝动脉增强晚期依次获得高、低管电压CT图像。标准卷积FBP用于重建140-kVp（协议A）和80-kVp（协议B）图像集，ASIR（协议C）用于重建80-kVp图像集。平均图像噪声；主动脉、肝脏和胰腺相对于肌肉的噪声对比比（CNR）；并对每种方案的有效剂量进行了评估。计算优点值（FOM）将每个方案的图像噪声和CNR归一化到有效剂量。采用Bonferroni调整多重比较的重复测量方差分析，比较三种方案在平均CNR、图像噪声和相应FOM方面的差异。并比较了不同方案下自定义模体产生的噪声功率谱。结果：当图像噪声归一化到有效剂量时，方案C与方案A （P= 0.0002）和方案B （P= 0.0001）相比，产生了大约两倍的噪声降低。当CNR归一化到有效剂量时，方案C对主动脉、肝脏和胰腺的CNR显著高于方案A（所有比较P= 0.0001），对肝脏的CNR显著高于方案B （P= 0.003）。方案A的平均有效剂量为17.5毫西弗+/- 0.6（标准误差），方案B和C的平均有效剂量为5.1毫西弗+/- 0.3（标准误差）。与方案A和B相比，方案C在整个空间频率频谱上产生了较小但可量化的降噪。结论：与标准FBP重建相比，ASIR算法提高了图像质量，并有可能降低肝动脉晚期低管电压、高管电流多探头腹部CT的辐射剂量。(c) rsna, 2010
Purpose: To investigate whether an adaptive statistical iterative reconstruction (ASIR) algorithm improves the image quality at low-tube-voltage (80-kVp), high-tube-current (675-mA) multidetector abdominal computed tomography (CT) during the late hepatic arterial phase.Materials and Methods: This prospective, single-center HIPAA-compliant study was institutional review board approved. Informed patient consent was obtained. Ten patients (six men, four women; mean age, 63 years; age range, 51-77 years) known or suspected to have hypervascular liver tumors underwent dual-energy 64-section multidetector CT. High-and low-tube-voltage CT images were acquired sequentially during the late hepatic arterial phase of contrast enhancement. Standard convolution FBP was used to reconstruct 140-kVp (protocol A) and 80-kVp (protocol B) image sets, and ASIR (protocol C) was used to reconstruct 80-kVp image sets. The mean image noise; contrast-to-noise ratio (CNR) relative to muscle for the aorta, liver, and pancreas; and effective dose with each protocol were assessed. A figure of merit (FOM) was computed to normalize the image noise and CNR for each protocol to effective dose. Repeated-measures analysis of variance with Bonferroni adjustment for multiple comparisons was used to compare differences in mean CNR, image noise, and corresponding FOM among the three protocols. The noise power spectra generated from a custom phantom with each protocol were also compared.Results: When image noise was normalized to effective dose, protocol C, as compared with protocols A (P=.0002) and B (P=.0001), yielded an approximately twofold reduction in noise. When the CNR was normalized to effective dose, protocol C yielded significantly higher CNRs for the aorta, liver, and pancreas than did protocol A (P=.0001 for all comparisons) and a significantly higher CNR for the liver than did protocol B (P=.003). Mean effective doses were 17.5 mSv +/- 0.6 (standard error) with protocol A and 5.1 mSv +/- 0.3 with protocols B and C. Compared with protocols A and B, protocol C yielded a small but quantifiable noise reduction across the entire spectrum of spatial frequencies.Conclusion: Compared with standard FBP reconstruction, an ASIR algorithm improves image quality and has the potential to decrease radiation dose at low-tube-voltage, high-tube-current multidetector abdominal CT during the late hepatic arterial phase. (C) RSNA, 2010