Thompson Eric M, Wagner Kate, Kronfeld Kassi, Selden Nathan R
Division of Neurosurgery, The Hospital for Sick Children, Toronto, Ontario, Canada; and.
J Neurosurg. 2014 Dec;121(6):1504-7. doi: 10.3171/2014.8.JNS132898. Epub 2014 Sep 26.
Radionuclide shuntography interpretation is uncertain when the tracer fails to enter the ventricles but quickly drains distally or when the tracer enters the ventricles but takes longer than 15 minutes to drain distally. The purpose of this study was to aid in the clinical interpretation of a variety of shuntography results and to determine the applicability of shuntography in different patient populations.
The results of 259 shuntograms were reviewed. Chi-square analysis was performed to evaluate the relationship between clinical variables and shuntography results. Two-by-two binary classification analyses were performed to determine the sensitivity, specificity, positive predictive value, and negative predictive value for 4 different combinatorial types of shuntography results based on 2 variables: ventricular tracer entry and distal tracer drainage.
Median patient age was 19 years, and 51% of patients were male. The most common presentation in patients undergoing shuntography was headache (169/254, 66.5%) with radiographically stable ventricle size. Of 227 patients with available imaging data, 163 (71.8%) presented with the same ventricle size as shown on a previous asymptomatic scan, 43 (18.9%) had larger ventricles, and 21 (9.2%) had smaller ventricles. Within 30 days of shuntography, 74 of 259 patients (28.6%) underwent surgical shunt exploration: 65 were found to have an obstructed shunt and 9 were found to have a patent shunt. Of those patients not undergoing surgery, the median length of benign clinical follow-up was 1051 days. Clinical variables were not significantly associated with shuntography results, including valve type (p = 0.180), ventricle size (p = 0.556), age (p = 0.549), distal drainage site (p = 0.098), and hydrocephalus etiology (p = 0.937). Shuntography results of patients with myelomeningocele were not dissociable from those of the group as a whole. Sensitivity to diagnose shunt failure was lowest (37.5%) but specificity was highest (97.2%) when the definition of a "normal" shuntogram included any tracer movement into the distal site within 45 minutes. Conversely, sensitivity was highest (87.5%) and specificity was lowest (51.4%) when the definition was limited exclusively to tracer entry into the ventricles and distal drainage within 15 minutes.
Even with a stringent definition of a "normal" shuntogram, sensitivity and specificity were relatively low for a diagnostic test. Clinical variables such as valve type, ventricle size, patient age, distal drainage site, and etiology of hydrocephalus were not associated with shuntography results.
当示踪剂未能进入脑室但迅速向远端引流时，或当示踪剂进入脑室但向远端引流的时间超过15分钟时，放射性核素分流造影的解读存在不确定性。本研究的目的是辅助临床解读各种分流造影结果，并确定分流造影在不同患者群体中的适用性。
回顾了259例分流造影的结果。进行卡方分析以评估临床变量与分流造影结果之间的关系。基于脑室示踪剂进入和示踪剂远端引流这两个变量，对4种不同组合类型的分流造影结果进行二乘二二元分类分析，以确定其敏感性、特异性、阳性预测值和阴性预测值。
患者的中位年龄为19岁，51%为男性。接受分流造影的患者中最常见的表现是头痛（169/254，66.5%），影像学上脑室大小稳定。在227例有可用影像数据的患者中，163例（71.8%）的脑室大小与之前无症状扫描时相同，43例（18.9%）脑室较大，21例（9.2%）脑室较小。在分流造影后30天内，259例患者中有74例（28.6%）接受了手术分流探查：65例发现分流梗阻，9例发现分流通畅。在未接受手术的患者中，良性临床随访的中位时长为1051天。临床变量与分流造影结果无显著相关性，包括瓣膜类型（p = 0.180）、脑室大小（p = 0.556）、年龄（p = 0.549）、远端引流部位（p = 0.098）和脑积水病因（p = 0.937）。脊髓脊膜膨出患者的分流造影结果与总体组无差异。当“正常”分流造影的定义包括示踪剂在45分钟内进入任何远端部位时，诊断分流失败的敏感性最低（37.5%），但特异性最高（97.2%）。相反，当定义仅限于示踪剂在15分钟内进入脑室并远端引流时，敏感性最高（87.5%），特异性最低（51.4%）。
即使对“正常”分流造影有严格定义，诊断试验的敏感性和特异性相对较低。瓣膜类型、脑室大小、患者年龄、远端引流部位和脑积水病因等临床变量与分流造影结果无关。
