Delibalta Semra, Genç Barış, Bilgici Meltem Ceyhan, Aslan Kerim
Acıbadem Mehmet Ali Aydınlar University Faculty of Medicine, Atakent Hospital, Department of Radiology, İstanbul, Türkiye.
Ondokuz Mayıs University Faculty of Medicine, Department of Radiology, Samsun, Türkiye.
Diagn Interv Radiol. 2024 Sep 2. doi: 10.4274/dir.2024.242720.
To evaluate the diagnostic efficacy of computed diffusion-weighted imaging (DWI) in pediatric posterior fossa tumors generated using high b-values.
We retrospectively performed our study on 32 pediatric patients who had undergone brain magnetic resonance imaging for a posterior fossa tumor between January 2016 and January 2022. The DWIs were evaluated for each patient by two blinded radiologists. The computed DWI (cDWI) was mathematically derived using a mono-exponential model from images with b = 0 and 1,000 s/mm and high b-values of 1,500, 2,000, 3,000, and 5,000 s/mm. The posterior fossa tumors were divided into two groups, low grade and high grade, and the tumor/thalamus signal intensity (SI) ratios were compared. The Mann-Whitney U test and receiver operating characteristic (ROC) curves were used to compare the diagnostic performance of the acquired DWI (DWI), apparent diffusion coefficient (ADC) maps, and cDWI (cDWI1500, cDWI, cDWI, and cDWI).
The comparison of the two tumor groups revealed that the tumor/thalamus SI ratio on the DWI and cDWI (cDWI1500, cDWI, cDWI, and cDWI) was statistically significantly higher in high-grade tumors ( < 0.001). In the ROC curve analysis, higher sensitivity and specificity were detected in the cDWI1500, cDWI, cDWI, and ADC maps (100%, 90.90%) compared with the DWI (80%, 81.80%). cDWI had the highest area under the curve (AUC) value compared with other parameters (AUC: 0.976).
cDWI generated using high b-values was successful in differentiating between low-grade and high-grade posterior fossa tumors without increasing imaging time.
cDWI created using high b-values can provide additional information about tumor grade in pediatric posterior fossa tumors without requiring additional imaging time.
评估使用高b值生成的计算机扩散加权成像（DWI）在小儿后颅窝肿瘤中的诊断效能。
我们回顾性地对2016年1月至2022年1月间因后颅窝肿瘤接受脑磁共振成像的32例儿科患者进行了研究。两名盲法放射科医生对每位患者的DWI进行评估。使用单指数模型从b = 0和1000 s/mm以及1500、2000、3000和5000 s/mm的高b值图像中数学推导计算出扩散加权成像（cDWI）。将后颅窝肿瘤分为低级别和高级别两组，并比较肿瘤/丘脑信号强度（SI）比值。采用曼-惠特尼U检验和受试者操作特征（ROC）曲线来比较所获取的DWI（DWI）、表观扩散系数（ADC）图和cDWI（cDWI1500、cDWI、cDWI和cDWI）的诊断性能。
两组肿瘤的比较显示，高级别肿瘤在DWI和cDWI（cDWI1500、cDWI、cDWI和cDWI）上的肿瘤/丘脑SI比值在统计学上显著更高（<0.001）。在ROC曲线分析中，与DWI（80%，81.80%）相比，cDWI1500、cDWI、cDWI和ADC图检测到更高的敏感性和特异性（100%，90.90%）。与其他参数相比，cDWI的曲线下面积（AUC）值最高（AUC：0.976）。
使用高b值生成的cDWI成功地区分了低级别和高级别后颅窝肿瘤，且无需增加成像时间。
使用高b值创建的cDWI可以在不增加成像时间的情况下，为小儿后颅窝肿瘤的肿瘤分级提供额外信息。
