Chen Wei, Su Guo-Yi, Zhou Yan, Jiang Jia-Suo, Jiang Run-Hao, Bao Mei-Ling, Xu Xiao-Quan, Wu Fei-Yun
Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Department of Medical Imaging, Subei People's Hospital, Medical School of Yangzhou University, Yangzhou, China.
J Magn Reson Imaging. 2021 Dec;54(6):1730-1741. doi: 10.1002/jmri.27836. Epub 2021 Jul 18.
Several magnetic resonance imaging (MRI) sequences have been applied to assess injured glands but without histological validation.
To evaluate longitudinal changes in multiparametric MRI (mp-MRI) of irradiated salivary glands in a rat model and investigate correlations between mp-MRI and histological findings.
Prospective.
Submandibular glands of 36 rats were radiated using a single dose of 15 Gy X-ray (irradiation [IR] group), and 6 other rats were enrolled into sham-IR group. mp-MRI were scanned 1 day after sham-IR (n = 6), or 1, 2, 4, 8, 12, 24 weeks after IR (n = 36, 6 per subgroup).
FIELD STRENGTH/SEQUENCE: A 3.0-T/Diffusion-weighted imaging (DWI), readout-segmented echo-planar imaging (EPI) sequence; intravoxel incoherent motion DWI, single-shot EPI sequence; T1 mapping, dual-flip-angle gradient-echo sequence with volumetric interpolated breath-hold examination; T2 mapping, turbo spin-echo sequence.
Parameters including apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo-diffusion coefficient (D ), perfusion fraction (f), T1 and T2 value were obtained. Histological examinations, including hematoxylin and eosin staining (for acinar cell fraction [AC%] detection), Masson's trichrome staining (for degree of fibrosis [F%] determination) and CD34-immunohistochemical staining (for microvessel density [MVD] calculation), were performed at corresponding time points.
One-way analysis of variance was used to compare the mp-MRI and histological parameters among different groups. Spearman correlation analysis was applied to determine the correlation between mp-MRI and histological parameters. Two-sided P ≤ 0.05 was considered statistically significant.
Changes of mp-MRI parameters (ADC, D, D , f, T1, T2) and histological results (AC%, F%, MVD) among the seven groups were all significant. ADC, D, and T2 values negatively correlated with AC% (ADC, r = -0.728; D, r = -0.773; T2, r = -0.600), f positively correlated with MVD (r = 0.496), and T1 values positively correlated with F% (r = 0.714). DATA CONCLUSION: mp-MRI might be able to noninvasively and quantitatively evaluate the dynamic pathological changes within the irradiated salivary glands.
1 TECHNICAL EFFICACY: Stage 2.
已有多种磁共振成像（MRI）序列用于评估受损腺体，但均未经过组织学验证。
评估大鼠模型中受照射唾液腺的多参数MRI（mp-MRI）的纵向变化，并研究mp-MRI与组织学结果之间的相关性。
前瞻性研究。
36只大鼠的下颌下腺接受单次15 Gy X射线照射（照射[IR]组），另外6只大鼠纳入假照射组。假照射后1天（n = 6）或照射后1、2、4、8、12、24周（n = 36，每组6只）进行mp-MRI扫描。
场强/序列：3.0 T/扩散加权成像（DWI），读出分段回波平面成像（EPI）序列；体素内不相干运动DWI，单次激发EPI序列；T1映射，具有容积内插屏气检查的双翻转角梯度回波序列；T2映射，快速自旋回波序列。
获取包括表观扩散系数（ADC）、纯扩散系数（D）、伪扩散系数（D*）、灌注分数（f）、T1和T2值等参数。在相应时间点进行组织学检查，包括苏木精和伊红染色（用于检测腺泡细胞分数[AC%]）、Masson三色染色（用于确定纤维化程度[F%]）和CD34免疫组织化学染色（用于计算微血管密度[MVD]）。
采用单因素方差分析比较不同组之间的mp-MRI和组织学参数。应用Spearman相关性分析确定mp-MRI与组织学参数之间的相关性。双侧P≤0.05被认为具有统计学意义。
七组之间mp-MRI参数（ADC、D、D*、f、T1、T2）和组织学结果（AC%、F%、MVD）的变化均具有显著性。ADC、D和T2值与AC%呈负相关（ADC，r = -0.728；D，r = -0.773；T2，r = -0.600），f与MVD呈正相关（r = 0.496），T1值与F%呈正相关（r = 0.714）。
mp-MRI可能能够无创且定量地评估受照射唾液腺内的动态病理变化。
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2级
