Diffusion-weighted imaging of placenta in intrauterine growth restriction with worsening Doppler US findings
Diffusion-weighted imaging of placenta in intrauterine growth restriction with worsening Doppler US findings
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DOI：
10.5152/dir.2019.18358
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发表时间：
2019-07-01
影响因子：
2.1
通讯作者：
Orturk, Ahmet
中科院分区：
文献类型：
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作者：
Gorkem, Sureyya Burcu;Coskun, Abdulhakim;Orturk, Ahmet
目的应用弥散加权成像（DWI）比较多普勒超声（US）表现恶化的宫内生长受限（IUGR）患者与多普勒超声（US）表现正常的对照组胎盘弥散的差异。方法采用DWI （b值0-1000 s/mm(2)）对63例（孕周，28-34周）患者的胎盘弥漫性差异进行前瞻性研究，其中50例IUGR患者（平均孕周，30周3天+/- 16.2天）多普勒超声检查结果恶化，13例多普勒超声检查结果正常（平均孕周，29周4天+/- 12.3天）。我们根据脐动脉搏动指数（PI）图的参考值将IUGR患者分为三组。胎盘表观扩散系数（ADC）通过手绘兴趣区（roi）进行计算(最小，8.04 cm(2)；最大，200厘米(2))。结果IUGR患者胎盘ADC值(平均值：1.624 +/- 0.181 x10-(3) mm (2) /s；1.35-1.96 x10（-3) mm(2)/s）与对照组相比显著降低(平均1.827 +/- 0.191 x10(-3) mm(2)/s；范围为1.35-2.84 x10(-3) mm(2)/s) （P = 0.001）。调整后ROI面积计算，3、2、1组的ADC值分别显著低于对照组（P < 0.05）；1、2组间差异无统计学意义（P < 0.05）。与无子痫前期患者相比，子痫前期患者胎盘弥散明显减少（P = 0.003）。对照组妊娠年龄对ADC值无显著影响（r= 0.08, P = 0.561）。ADC检测IUGR的敏感性为72%，特异性为84.6%，阴性预测值为44%，阳性预测值为94.7%，临界值为1.727 x10(-3) mm(2)/s。结论胎盘ADC值对IUGR严重程度的诊断估计与脐动脉PI相当。考虑到在IUGR发病的早期，胎盘弥散减弱，ADC代替脐动脉PI作为IUGR的标志物有可能确定胎盘弥散减弱的阈值。因此，应在常规胎儿MRI的基础上增加DWI，以显示胎盘的弥散变化。
PURPOSEWe aimed to compare the placental diffusion difference between intrauterine growth restriction (IUGR) patients with worsening Doppler ultrasonography (US) findings and control group with normal Doppler US findings by using diffusion-weighted imaging (DWI).METHODSWe performed a prospective study to compare the placental diffusion difference in 63 patients (gestational week, 28-34 weeks), including 50 IUGR patients (mean gestational week, 30 weeks 3 days +/- 16.2 days) with worsening Doppler US findings and 13 patients with normal Doppler US findings (mean gestational week, 29 weeks 4 days +/- 12.3 days) by using DWI (b value, 0-1000 s/mm(2)). We classified IUGR patients into three groups according to the reference values of the umbilical artery pulsatility index (PI) chart. Placenta apparent diffusion coefficient (ADC) calculations were performed by freehand drawn regions-of-interest (ROIs) (min, 8.04 cm(2); max, 200 cm(2)).RESULTSPlacental ADC values in IUGR patients (mean, 1.624 +/- 0.181 x10-(3) mm (2) /s; range, 1.35-1.96 x10(-3) mm(2)/s) were significantly reduced compared with the control group (mean, 1.827 +/- 0.191 x10(-3) mm(2)/s; range, 1.35-2.84 x10(-3) mm(2)/s) (P = 0.001). For adjusted ROI area calculation, ADC values were significantly lower in groups 3, 2 and 1, respectively, compared with the control group (P < 0.05); and there was no significant difference between groups 1 and 2 (P > 0.05). Preeclampsia significantly reduced the placental diffusion compared with patients without preeclampsia (P = 0.003). Gestational aging did not significantly affect ADC values in control patients (r= 0.08, P = 0.561). The sensitivity, specificity, negative and positive predictive values of ADC to detect IUGR were 72%, 84.6%, 44%, and 94.7% with a cutoff value of 1.727 x10(-3) mm(2)/s, respectively.CONCLUSIONThe diagnostic estimation of placental ADC values to predict the severity of IUGR is comparable to that of umbilical artery PI. Considering that at the very early onset of IUGR, placental diffusion diminishes, ADC as a marker for IUGR in lieu of umbilical artery PI has the potential to determine the threshold for decreased placental diffusion. Therefore, DWI should be added to routine fetal MRI to show diffusion changes in placenta.