Department of Radiology, University of Alberta Hospital and Stollery Children's Hospital, 2J2.00 WC Mackenzie Health Sciences Centre, 8440 112 St. NW, Edmonton, Alberta, T6G 2R7, Canada.
Department of Radiology, Hershey Children's Hospital and Penn State Health Milton S. Hershey Medical Center, Penn State College of Medicine, Philadelphia, PA, USA.
Pediatr Radiol. 2020 Oct;50(11):1587-1593. doi: 10.1007/s00247-020-04744-8. Epub 2020 Jun 29.
While magnetic resonance imaging (MRI) of the pelvis and hips is common in pediatric patients, to date there are no data on the quantification of normal hip joint fluid volume in this patient population.
We sought to assess the feasibility and reliability of quantitative hip joint fluid measurement in the pediatric population to estimate the normal volume of fluid in a pediatric hip joint.
Seventy healthy children ages 8-17 years underwent a pelvic MRI including a large field of view coronal T2 fat-saturated sequence where hips were entirely imaged. Following 3 training sessions, 2 readers with experience in musculoskeletal imaging performed volumetric quantitative measurements of hip fluid (140 hips) using semiautomated pixel-based thresholding on custom MATLAB software.
The mean processing time per hip was 2 min, 41 s. The mean volume of fluid in a hip joint was 2.1 mL (range: 0.38-5.41 mL), increasing slightly with age. Volumes were also greater in boys than in girls (P=0.004). Intra-observer and interobserver agreement were high (intra-class correlation coefficients 0.93 and 0.98, respectively), with mean volume differences of 0.04 mL for intra-observer and 0.09 mL for interobserver.
A semiautomated pixel-based thresholding approach was feasible and reliable for measuring joint fluid in pediatric hip MRI. The average fluid volume of 2.1 mL can represent a visually substantial quantity of fluid per MRI slice, particularly in small children, and should not be misinterpreted as a joint effusion.
虽然骨盆和髋关节的磁共振成像（MRI）在儿科患者中很常见，但迄今为止，尚无关于该患者人群正常髋关节液量定量的数据。
我们旨在评估在儿科人群中进行髋关节关节液定量测量的可行性和可靠性，以估计小儿髋关节液的正常量。
70 名 8-17 岁的健康儿童接受了骨盆 MRI 检查，包括完全成像髋关节的大视野冠状 T2 脂肪饱和序列。在进行了 3 次培训后，2 名具有肌肉骨骼成像经验的读者使用基于自定义 MATLAB 软件的半自动像素阈值法对髋关节液进行了容积定量测量（140 个髋关节）。
每个髋关节的平均处理时间为 2 分 41 秒。髋关节液的平均体积为 2.1 毫升（范围：0.38-5.41 毫升），随年龄略有增加。男孩的髋关节液体积也大于女孩（P=0.004）。观察者内和观察者间的一致性均较高（组内相关系数分别为 0.93 和 0.98），观察者内平均体积差异为 0.04 毫升，观察者间平均体积差异为 0.09 毫升。
基于半自动像素阈值法的方法对于测量儿科髋关节 MRI 中的关节液是可行且可靠的。2.1 毫升的平均液量代表每 MRI 切片中有可观的液体量，特别是在小孩子中，不应被错误地解释为关节积液。
