Automated posterior cranial fossa volumetry by MRI: applications to Chiari malformation type I.
Automated posterior cranial fossa volumetry by MRI: applications to Chiari malformation type I.
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DOI：
10.3174/ajnr.a3435
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发表时间：
2013-09
期刊：
影响因子：
--
通讯作者：
Alperin N
中科院分区：
文献类型：
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作者：
Bagci AM;Lee SH;Nagornaya N;Green BA;Alperin N
量化PCF体积和PCF拥挤程度有助于CMI扁桃体疝的鉴别诊断和预测手术结果。然而，缺乏自动化的方法限制了PCF体积测定的临床应用。提出了一种适合CMI的基于图谱的PCF自动分割方法。从精度和与人工分割的空间重叠度两方面评价了该方法的性能。报道了PCF体积与先前提出的线性地标长度之间的关联程度。使用3T扫描仪获得的1毫米各向同性分辨率的t1加权体积MR成像数据来自14名CMI患者和3名健康受试者。人工圈定9例患者的PCF，用于建立基于图谱的PCF自动分割方法的cmi特异性参考。通过t检验验证了5个不同CMI数据集的人工和自动分割的一致性。通过对3名健康受试者进行2次重复扫描，建立了测量的可重复性。采用Pearson相关法确定PCF体积与6个线性标志之间的线性关联程度。使用自动方法和人工方法测得的PCF体积相似，分别为196.2±8.7 mL和196.9±11.0 mL。平均相对差为- 0.3±1.9%，无统计学意义。测量变异性低，平均绝对百分比值为0.6±0.2%。PCF线性标志与PCF体积均无显著相关性。使用基于图谱的自动分割方法，可以可靠地测量CMI患者的PCF和组织含量体积。
Quantification of PCF volume and the degree of PCF crowdedness were found beneficial for differential diagnosis of tonsillar herniation and prediction of surgical outcome in CMI. However, lack of automated methods limits the clinical use of PCF volumetry. An atlas-based method for automated PCF segmentation tailored for CMI is presented. The method performance is assessed in terms of accuracy and spatial overlap with manual segmentation. The degree of association between PCF volumes and the lengths of previously proposed linear landmarks is reported. T1-weighted volumetric MR imaging data with 1-mm isotropic resolution obtained with the use of a 3T scanner from 14 patients with CMI and 3 healthy subjects were used for the study. Manually delineated PCF from 9 patients was used to establish a CMI-specific reference for an atlas-based automated PCF parcellation approach. Agreement between manual and automated segmentation of 5 different CMI datasets was verified by means of the t test. Measurement reproducibility was established through the use of 2 repeated scans from 3 healthy subjects. Degree of linear association between PCF volume and 6 linear landmarks was determined by means of Pearson correlation. PCF volumes measured by use of the automated method and with manual delineation were similar, 196.2 ± 8.7 mL versus 196.9 ± 11.0 mL, respectively. The mean relative difference of −0.3 ± 1.9% was not statistically significant. Low measurement variability, with a mean absolute percentage value of 0.6 ± 0.2%, was achieved. None of the PCF linear landmarks were significantly associated with PCF volume. PCF and tissue content volumes can be reliably measured in patients with CMI by use of an atlas-based automated segmentation method.