Emblem Kyrre E, Nedregaard Baard, Nome Terje, Due-Tonnessen Paulina, Hald John K, Scheie David, Borota Olivera Casar, Cvancarova Milada, Bjornerud Atle
Departments of Medical Physics, Rikshospitalet-Radiumhospitalet Medical Centre, Sognsvannsveien 20, N-0027 Oslo, Norway.
Radiology. 2008 Jun;247(3):808-17. doi: 10.1148/radiol.2473070571.
To retrospectively compare the diagnostic accuracy of an alternative method used to grade gliomas that is based on histogram analysis of normalized cerebral blood volume (CBV) values from the entire tumor volume (obtained with the histogram method) with that of the hot-spot method, with histologic analysis as the reference standard.
The medical ethics committee approved this study, and all patients provided informed consent. Fifty-three patients (24 female, 29 male; mean age, 48 years; age range, 14-76 years) with histologically confirmed gliomas were examined with dynamic contrast material-enhanced 1.5-T magnetic resonance (MR) imaging. CBV maps were created and normalized to unaffected white matter (normalized CBV maps). Four neuroradiologists independently measured the distribution of whole-tumor normalized CBVs and analyzed this distribution by classifying the values into area-normalized bins. Glioma grading was performed by assessing the normalized peak height of the histogram distributions. Logistic regression analysis and interobserver agreement were used to compare the proposed method with a hot-spot method in which only the maximum normalized CBV was used.
For the histogram method, diagnostic accuracy was independent of the observer. Interobserver agreement was almost perfect for the histogram method (kappa = 0.923) and moderate for the hot-spot method (kappa = 0.559). For all observers, sensitivity was higher with the histogram method (90%) than with the hot-spot method (55%-76%).
Glioma grading based on histogram analysis of normalized CBV heterogeneity is an alternative to the established hot-spot method, as it offers increased diagnostic accuracy and interobserver agreement.
回顾性比较一种基于对整个肿瘤体积的标准化脑血容量（CBV）值进行直方图分析（直方图法）的胶质瘤分级替代方法与热点法的诊断准确性，并以组织学分析作为参考标准。
医学伦理委员会批准了本研究，所有患者均提供了知情同意书。对53例经组织学证实为胶质瘤的患者（24例女性，29例男性；平均年龄48岁；年龄范围14 - 76岁）进行了动态对比剂增强1.5-T磁共振（MR）成像检查。创建CBV图并将其标准化为未受影响的白质（标准化CBV图）。四名神经放射科医生独立测量全肿瘤标准化CBV的分布，并通过将值分类到面积标准化的区间来分析该分布。通过评估直方图分布的标准化峰值高度进行胶质瘤分级。使用逻辑回归分析和观察者间一致性来比较所提出的方法与仅使用最大标准化CBV的热点法。
对于直方图法，诊断准确性与观察者无关。观察者间一致性对于直方图法几乎是完美的（kappa = 0.923），而对于热点法为中等（kappa = 0.559）。对于所有观察者，直方图法的敏感性（90%）高于热点法（55% - 76%）。
基于标准化CBV异质性直方图分析的胶质瘤分级是既定热点法的一种替代方法，因为它提供了更高的诊断准确性和观察者间一致性。
