Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, Maryland, USA.
Center for Neuroscience and Regenerative Medicine, Bethesda, Maryland, USA.
J Magn Reson Imaging. 2022 Nov;56(5):1529-1535. doi: 10.1002/jmri.28326. Epub 2022 Jul 19.
Susceptibility-weighted imaging (SWI) provides superior image contrast of cerebral microhemorrhages (CMBs). It is based on a three-dimensional (3D) gradient echo (GRE) sequence with a relatively long imaging time.
To evaluate whether an accelerated 3D segmented echo planar imaging SWI is comparable to GRE SWI in detecting CMBs in traumatic brain injury (TBI).
Prospective.
Four healthy volunteers and 46 consecutive subjects (38.0 ± 14.4 years, 16 females; 12 mild, 13 moderate, and 7 severe TBI).
FIELD STRENGTH/SEQUENCE: A 3 T scanner/3D gradient echo and 3D segmented echo planar imaging (segEPI).
Brain images were acquired using GRE and segEPI in a single session (imaging time = 9 minutes 47 seconds and 1 minute 30 seconds, respectively). The signal-to-noise ratio (SNR) calculated from healthy volunteer thalamus and centrum semiovale were compared. CMBs were counted by three raters blinded to diagnostic information.
A t-test was used to assess SNR difference. Pearson correlation and Wilcoxon signed-rank test were performed using CMB counts. The intermethod agreement was evaluated using Bland-Altman method. Intermethod and interrater reliabilities of image-based diffuse axonal injury (DAI) diagnoses were evaluated using Cohen's kappa and percent agreement. P ≤ 0.05 was considered statistically significant.
Thalamus SNRs were 16.9 ± 2.2 and 16.5 ± 3 for GRE and segEPI (P = 0.84), respectively. Centrum semiovale SNRs were 25.8 ± 4.6 and 21.1 ± 2.7 (P = 0.13). The correlation coefficient of CMBs was 0.93, and differences were not significant (P = 0.56-0.85). For DAI diagnoses, Cohen's kappa was 0.62-0.84 and percent agreement was 85%-94%.
CMB counts on segEPI and GRE were highly correlated, and DAI diagnosis was made equally effectively. segEPI SWI can potentially replace GRE SWI in detecting TBI CMBs, especially when time constraints are critical.
1 TECHNICAL EFFICACY: Stage 2.
磁敏感加权成像（SWI）提供了优越的脑微出血（CMBs）的图像对比。它基于三维（3D）梯度回波（GRE）序列，具有相对较长的成像时间。
评估加速 3D 分段回波平面成像 SWI 在检测创伤性脑损伤（TBI）中的 CMBs 方面是否与 GRE SWI 相当。
前瞻性。
4 名健康志愿者和 46 名连续受试者（38.0±14.4 岁，16 名女性；12 名轻度，13 名中度，7 名重度 TBI）。
磁场强度/序列：3T 扫描仪/3D 梯度回波和 3D 分段回波平面成像（segEPI）。
使用 GRE 和 segEPI 在单次扫描中采集脑图像（成像时间分别为 9 分 47 秒和 1 分 30 秒）。从健康志愿者的丘脑和半卵圆中心计算信噪比（SNR）。由三位盲于诊断信息的评分者计数 CMBs。
使用 t 检验评估 SNR 差异。使用 CMB 计数进行 Pearson 相关性和 Wilcoxon 符号秩检验。使用 Bland-Altman 方法评估两种方法之间的一致性。使用 Cohen 的 kappa 和百分比一致性评估基于图像的弥漫性轴索损伤（DAI）诊断的两种方法之间和评分者之间的可靠性。P≤0.05 被认为具有统计学意义。
GRE 和 segEPI 的丘脑 SNR 分别为 16.9±2.2 和 16.5±3（P=0.84）。GRE 和 segEPI 的半卵圆中心 SNR 分别为 25.8±4.6 和 21.1±2.7（P=0.13）。CMBs 的相关系数为 0.93，差异无统计学意义（P=0.56-0.85）。对于 DAI 诊断，Cohen 的 kappa 值为 0.62-0.84，百分比一致性为 85%-94%。
segEPI 和 GRE 上的 CMB 计数高度相关，DAI 诊断同样有效。segEPI SWI 有可能替代 GRE SWI 检测 TBI CMBs，特别是在时间限制至关重要的情况下。
1 技术功效：第 2 阶段。
