Diffusion-weighted MRI of the prostate at 3.0 T: Comparison of endorectal coil (ERC) MRI and phased-array coil (PAC) MRI-The impact of SNR on ADC measurement
Diffusion-weighted MRI of the prostate at 3.0 T: Comparison of endorectal coil (ERC) MRI and phased-array coil (PAC) MRI-The impact of SNR on ADC measurement
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DOI：
10.1016/j.ejrad.2013.04.041
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发表时间：
2013-10-01
影响因子：
3.3
通讯作者：
Hricak, Hedvig
中科院分区：
文献类型：
--
作者：
Mazaheri, Yousef;Vargas, H. Alberto;Hricak, Hedvig
目的：比较在3.0 T下使用直肠内和相控阵线圈（ERC + PAC）获得的前列腺弥散加权MR（DW-MR）图像测量的ADC值与使用8通道躯干相控阵线圈（PAC）获得的DW-MRI图像测量的ADC值。方法：机构审查委员会发布了这项符合HIPAA的研究的知情同意豁免。25例经活检证实的前列腺癌患者在同一个疗程中使用2种不同的线圈排列（ERC + PAC和仅PAC）进行了标准3-T MRI。使用两种线圈布置在5个b值（0、600、1000、1200和1500 s/mm（2））下采集DW-MRI。在B = 0的图像上，信噪比（SNR）被测量为来自PZ和TZ ROI的平均信号与直肠中无伪影ROI中平均信号的标准差的比值。在ERC-MRI和PAC-MRI的外周带和移行带中识别出匹配的感兴趣区（ROI）。对于每个ROI，计算所有零和非零b值组合的平均ADC值。PZ时ERC-MRI的平均SNR（66.33 +/- 27.07）和TZ（32.69 +/- 12.52）分别是PAC-MRI（（7.32 +/- 2.30）和（6.13 +/- 1.56））的9.27和5.52倍（两者均为P < 0.0001）。PAC-MRI在PZ和TZ的所有b值下获得的DW-MR图像的ADC值显著低于ERC-MRI（P均< 0.001）。结论：与使用ERC获得的类似测量值相比，使用PAC获得的前列腺DW-MR图像的较低SNR可显著降低在较高b值下的ADC值。为了满足这些要求，临床MR系统应具有包含噪声分布的图像处理能力。(C)2013爱思唯尔爱尔兰有限公司保留所有权利。
Purpose: To compare ADC values measured from diffusion-weighted MR (DW-MR) images of the prostate obtained with both endorectal and phased-array coils (ERC + PAC) to those from DW-MRI images obtained with an eight-channel torso phased-array coil (PAC) at 3.0 T.Methods: The institutional review board issued a waiver of informed consent for this HIPAA-compliant study. Twenty-five patients with biopsy-proven prostate cancer underwent standard 3-T MRI using 2 different coil arrangements (ERC + PAC and PAC only) in the same session. DW-MRI at five b-values (0, 600, 1000, 1200, and 1500 s/mm(2)) were acquired using both coil arrangements. On b = 0 images, signal-to-noise ratios (SNRs) were measured as the ratio of the mean signal from PZ and TZ ROIs to the standard deviation from the mean signal in an artifact-free ROI in the rectum. Matching regions-of-interest (ROIs) were identified in the peripheral zone and transition zone on ERC-MRI and PAC-MRI. For each ROI, mean ADC values for all zero and non-zero b-value combinations were computed.Results: Mean SNR with ERC-MRI at PZ (66.33 +/- 27.07) and TZ (32.69 +/- 12.52) was 9.27 and 5.52 times higher than with PAC-MRI ((7.32 +/- 2.30) and (6.13 +/- 1.56), respectively) (P < 0.0001 for both). ADCs from DW-MR images obtained with all b-values in the PZ and TZ were significantly lower with PAC-MRI than with ERC-MRI (P < 0.001 for all).Conclusion: Lower SNR of DW-MR images of the prostate obtained with a PAC can significantly decrease ADC values at higher b-values compared to similar measurements obtained using the ERC. To address these requirements, clinical MR systems should have image processing capabilities which incorporate the noise distribution. (C) 2013 Elsevier Ireland Ltd. All rights reserved.