Intracranial Calcifications and Hemorrhages: Characterization with Quantitative Susceptibility Mapping
Intracranial Calcifications and Hemorrhages: Characterization with Quantitative Susceptibility Mapping
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DOI：
10.1148/radiol.13122640
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发表时间：
2014-02-01
期刊：
影响因子：
19.7
通讯作者：
Wang, Yi
中科院分区：
文献类型：
--
作者：
Chen, Weiwei;Zhu, Wenzhen;Wang, Yi
目的：比较梯度回波(GRE)位相磁共振(MR)成像和定量磁化率图(QSM)在检测颅内钙化和出血中的作用。入选38例患者，男24例，女14例，平均年龄33岁+/-16[标准差]，均经CT、MR检查(检查间隔1.78天+/-1.31天)和临床资料确诊为颅内钙化和/或出血。从相同的GRE数据重建GRE和QSM图像。两位经验丰富的神经放射学家在两次随机会议中独立地确认了QSM和GRE相图上的钙化和出血。计算敏感度、特异度和观察者间一致性，并与McNemar检验和kappa系数进行比较。测量钙化负荷和体积以衡量与CT的相关性。总共检测到156个病变：62个出血，89个钙化，5个混合病变，既有出血又有钙化。大多数病变(96.7%，146个)在QSM图像上有明显征象，提示出血或钙化的特定诊断，而其中一半(76/151，50.3%)在GRE相图上是不均匀的，因此很难定性。在两个独立观察者的平均水平上，QSM检测出血的敏感性和特异性分别为89.5%和94.5%，显著高于GRE时相成像(分别为71%和80%；P<；两种读数均为0.05)。QSM对钙化诊断的敏感性为80.5%，略高于GRE时相显像(71%；P=0.08和0.10)，特异度为93.5%，显著高于GRE时相显像(76.5%；P<；0.05)。QSM在区分出血和钙化方面明显优于GRE时相成像(kappa分别为0.91和0.55；P<；0.05)。QSM在区分颅内钙化和出血、检测出血的敏感性和特异性以及钙化的特异性方面优于GRE时相成像。
To compare gradient-echo (GRE) phase magnetic resonance (MR) imaging and quantitative susceptibility mapping (QSM) in the detection of intracranial calcifications and hemorrhages.This retrospective study was approved by the institutional review board. Thirty-eight patients (24 male, 14 female; mean age, 33 years +/- 16 [standard deviation]) with intracranial calcifications and/ or hemorrhages diagnosed on the basis of computed tomography (CT), MR imaging (interval between examinations, 1.78 days +/- 1.31), and clinical information were selected. GRE and QSM images were reconstructed from the same GRE data. Two experienced neuroradiologists independently identified the calcifications and hemorrhages on the QSM and GRE phase images in two randomized sessions. Sensitivity, specificity, and interobserver agreement were computed and compared with the McNemar test and kappa coefficients. Calcification loads and volumes were measured to gauge intermodality correlations with CT.A total of 156 lesions were detected: 62 hemorrhages, 89 calcifications, and five mixed lesions containing both hemorrhage and calcification. Most of these lesions (146 of 151 lesions, 96.7%) had a dominant sign on QSM images suggestive of a specific diagnosis of hemorrhage or calcium, whereas half of these lesions (76 of 151, 50.3%) were heterogeneous on GRE phase images and thus were difficult to characterize. Averaged over the two independent observers for detecting hemorrhages, QSM achieved a sensitivity of 89.5% and a specificity of 94.5%, which were significantly higher than those at GRE phase imaging (71% and 80%, respectively; P < .05 for both readers). In the identification of calcifications, QSM achieved a sensitivity of 80.5%, which was marginally higher than that with GRE phase imaging (71%; P = .08 and .10 for the two readers), and a specificity of 93.5%, which was significantly higher than that with GRE phase imaging (76.5%; P < .05 for both readers). QSM achieved significantly better interobserver agreements than GRE phase imaging in the differentiation of hemorrhage from calcification (kappa: 0.91 vs 0.55, respectively; P < .05).QSM is superior to GRE phase imaging in the differentiation of intracranial calcifications from hemorrhages and with regard to the sensitivity and specificity of detecting hemorrhages and the specificity of detecting calcifications.