Siemens Healthcare, Erlangen, Germany.
Invest Radiol. 2019 Aug;54(8):524-530. doi: 10.1097/RLI.0000000000000560.
Comparison of the diagnostic value of simultaneous multislice (SMS) accelerated diffusion-weighted echo planar imaging (EPI) of malignant and benign lesions of the breast compared with a reference EPI sequence.
The study was approved by the institutional ethics committee. Sixty-eight patients were examined with a diffusion-weighted EPI (reference EPI; TE = 54 milliseconds; TR = 9000 milliseconds; TA, 3:27 minutes) and a diffusion-weighted SMS accelerated EPI (SMS EPI; acceleration factor 2; TE = 58 milliseconds; TR = 4300 milliseconds; TA, 1:53 minutes) in addition to the standard magnetic resonance imaging (MRI) protocol. Further acquisition parameters were as follows: 3 T MAGNETOM Skyra (Siemens Healthcare, Erlangen, Germany), 2.5-mm isotropic resolution, field of view = 185 to 190 × 350 mm, 62 slices, b = 50 and 800 s/mm with 1 and 4 averages, respectively. A dedicated 16-channel bilateral breast coil was used for imaging. Image quality was evaluated with respect to the presence of artifacts, signal voids, and quality of fat suppression. These parameters were rated using a 5-point Likert scale (1 = very strong to 5 = negligible). The apparent diffusion coefficient (ADC) was measured in 72 focal lesions (46 breast carcinomas and 26 benign lesions), and the diagnostic value of the 2 datasets was statistically evaluated and compared. The evaluation was performed a second time excluding cysts.
Artifacts and signal voids were negligible in both sequences (mean on Likert scale for reference EPI 4.68 vs SMS EPI 4.65, P = 0.52, and mean on Likert scale for reference EPI 4.85 vs SMS EPI 4.77, P = 0.14). Fat suppression was significantly better in SMS EPI (mean on Likert scale 3.28 vs 2.97, P < 0.001, Pearson r = 0.49). For benign lesions, the mean ADC in both EPI sequences was 1.86 · 10 mm/s. For malignant lesions, a mean ADC of 0.90 · 10 mm/s for the reference EPI and 0.89 · 10 mm/s for the SMS EPI was found. No significant difference between the EPI sequences was observed for ADC values (P = 0.75) and for the area under the curve (SMS, 0.985; no SMS, 0.975). The cutoff for differentiation of benign and malignant lesions was at ADC = 1.42 · 10 mm/s for SMS EPI (sensitivity, 1; specificity, 0.88) and at 1.23 · 10 mm/s for the reference EPI (sensitivity, 1; specificity, 0.92). Excluding the cysts, the cutoff for differentiation of benign and malignant lesions was at ADC = 1.11 · 10 mm/s for SMS EPI (sensitivity, 0.89; specificity, 0.93) and at 1.23 · 10 mm/s for the reference EPI (sensitivity, 1; specificity, 0.87).
Our data indicate that SMS acceleration can be used for diffusion imaging in breast MRI in clinical practice. Simultaneous multislice EPI achieved the same diagnostic accuracy in breast MRI, but in a substantially reduced scan time.
比较恶性和良性乳腺病变的同时多层（SMS）加速扩散加权回波平面成像（EPI）与参考 EPI 序列的诊断价值。
本研究经机构伦理委员会批准。68 例患者接受扩散加权 EPI（参考 EPI；TE = 54 毫秒；TR = 9000 毫秒；TA，3:27 分钟）和扩散加权 SMS 加速 EPI（SMS EPI；加速因子 2；TE = 58 毫秒；TR = 4300 毫秒；TA，1:53 分钟）以及标准磁共振成像（MRI）方案检查。进一步的采集参数如下：3T MAGNETOM Skyra（西门子医疗，德国埃朗根），2.5 毫米各向同性分辨率，视野 = 185 至 190 × 350 毫米，62 层，b = 50 和 800 s/mm，分别有 1 和 4 次平均。使用专用的 16 通道双侧乳房线圈进行成像。根据存在伪影、信号缺失和脂肪抑制质量，评估图像质量。这些参数使用 5 分李克特量表（1 = 非常强至 5 = 可忽略不计）进行评分。在 72 个局灶性病变（46 例乳腺癌和 26 例良性病变）中测量表观扩散系数（ADC），并对 2 组数据集的诊断价值进行统计学评估和比较。评估第二次排除囊肿。
两种序列的伪影和信号缺失均可以忽略不计（参考 EPI 的平均 Likert 评分为 4.68，SMS EPI 的平均 Likert 评分为 4.65，P = 0.52，参考 EPI 的平均 Likert 评分为 4.85，SMS EPI 的平均 Likert 评分为 4.77，P = 0.14）。SMS EPI 的脂肪抑制明显更好（Likert 量表平均评分为 3.28，2.97，P < 0.001，Pearson r = 0.49）。对于良性病变，两种 EPI 序列的平均 ADC 均为 1.86·10mm/s。对于恶性病变，参考 EPI 的平均 ADC 为 0.90·10mm/s，SMS EPI 的平均 ADC 为 0.89·10mm/s。EPI 序列的 ADC 值（P = 0.75）和曲线下面积（SMS，0.985；无 SMS，0.975）之间无显著差异。区分良性和恶性病变的截断值为 SMS EPI 的 ADC = 1.42·10mm/s（灵敏度，1；特异性，0.88）和参考 EPI 的 ADC = 1.23·10mm/s（灵敏度，1；特异性，0.92）。排除囊肿后，区分良性和恶性病变的截断值为 SMS EPI 的 ADC = 1.11·10mm/s（灵敏度，0.89；特异性，0.93）和参考 EPI 的 ADC = 1.23·10mm/s（灵敏度，1；特异性，0.87）。
我们的数据表明，SMS 加速可用于临床实践中的乳腺 MRI 扩散成像。同时多层 EPI 在乳腺 MRI 中具有相同的诊断准确性，但扫描时间大大缩短。
