Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA; Division of Neonatal-Perinatal Medicine, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Radiology, Mayo Clinic Medical Center, Jacksonville, FL, USA.
Magn Reson Imaging. 2021 Jul;80:26-32. doi: 10.1016/j.mri.2021.03.007. Epub 2021 Mar 22.
Placenta accreta spectrum (PAS) disorders occur when the placenta adheres abnormally to the uterine myometrium and can have devastating effects on maternal health due to risks of massive postpartum hemorrhage and possible need for emergency hysterectomy. PAS can be difficult to diagnose using routine clinical imaging with ultrasound and structural MRI.
To determine feasibility of using intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) analysis in the diagnosis of the placenta accreta spectrum disorders in pregnant women.
A total of 49 pregnant women were recruited including 14 with pathologically confirmed cases of PAS and 35 health controls without prior cesarean delivery and no suspected PAS by ultrasound. All women underwent diffusion-weighted imaging with an 8 b-value scanning sequence. A semi-automated method for image processing was used, creating a 3D object map, which was then fit to a biexponential signal decay curve for IVIM modeling to determine slow diffusion (D), fast diffusion (D), and perfusion fraction (P).
Our results demonstrated a high degree of model fitting (R ≥ 0.98), with P significantly higher in those with PAS compared to healthy controls (0.451 ± 0.019 versus 0.341 ± 0.022, p = 0.002). By contrast, no statistical difference in the D (1.70 × 10 ± 0.38 × 10 versus 1.48 × 10 ± 0.08 × 10 mm/s, p = 0.211) or D (1.34 × 10 ± 0.10 × 10 versus 1.45 × 10 ± 0.007 × 10 mm/s, p = 0.215) was found between subjects with PAS and healthy controls.
The use of MRI, and IVIM modeling in particular, may have potential in aiding in the diagnosis of PAS when other imaging modalities are equivocal. However, the widespread use of these techniques will require generation of large normative data sets, consistent sequencing protocols, and streamlined analysis techniques.
胎盘植入谱系（PAS）疾病是指胎盘异常附着于子宫平滑肌层，可能会导致产后大出血和紧急子宫切除等严重后果。常规超声和结构磁共振成像（MRI）检查对 PAS 的诊断具有一定难度。
评估磁共振扩散加权成像中的体素内不相干运动（IVIM）分析在诊断胎盘植入谱系疾病中的可行性。
共纳入 49 例孕妇，包括 14 例经病理证实的 PAS 患者和 35 例无剖宫产史且超声检查未见 PAS 患者。所有患者均行 8 b 值扩散加权成像。采用半自动图像处理方法，创建 3D 物体图，然后拟合双指数信号衰减曲线进行 IVIM 建模，以确定慢速扩散（D）、快速扩散（D）和灌注分数（P）。
我们的结果显示模型拟合度高（R≥0.98），P 值在 PAS 患者中明显高于健康对照组（0.451±0.019 比 0.341±0.022，p=0.002）。相反，PAS 患者与健康对照组之间 D（1.70×10±0.38×10 比 1.48×10±0.08×10mm/s，p=0.211）和 D（1.34×10±0.10×10 比 1.45×10±0.007×10mm/s，p=0.215）无统计学差异。
当其他影像学检查结果不确定时，MRI 特别是 IVIM 模型可能有助于 PAS 的诊断。但是，这些技术的广泛应用需要生成大量的正常数据集、一致的测序方案和简化的分析技术。
