Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Tao-Yuan, Taiwan.
Chang Gung University College of Medicine, Tao-Yuan, Taiwan.
J Magn Reson Imaging. 2021 Aug;54(2):598-606. doi: 10.1002/jmri.27563. Epub 2021 Feb 17.
Obtaining pus for microbial cultures is one of the surgical aims in patients with brain abscess. Predictors of microbial yields are necessary as they help in treatment planning.
To investigate the relationship between microbial culture yields of brain abscesses and their apparent diffusion coefficient (ADC) values and clinical characteristics.
Retrospective.
Eighty-four patients diagnosed with brain abscess by surgery and histopathology (59 with positive abscess cultures).
FIELD STRENGTH/SEQUENCE: Diffusion-weighted, T2-weigthed, and contrast-enhanced T1-weighted imaging at 1.5 T and 3 T.
Contrast-enhanced T1-weighted images were co-registered to ADC maps. Three neuroradiologists determined abscess imaging characteristics (distribution, location, and ventricular rupture), and two measured abscess volumes and ADC values. Clinical characteristics collected included sex, age, fever, underlying diseases, infection sources, white blood cell count, percentage of segmented neutrophils, C-reactive protein level, regimen and duration of empirical antibiotics, and types of surgery.
Interobserver differences were assessed with Fleiss kappa and intraclass correlation coefficients. The differences in clinical and imaging factors between the positive and negative culture groups were compared with Chi-square analysis or Student's t test. All factors were subjected to multivariable logistic regression analysis to assess their associations with microbial culture yields, and factors with statistical significance were evaluated with receiver operating characteristic curve analysis to assess their diagnostic performance in discriminating the two groups.
Mean ADC (×10 mm /s) of culture-negative abscesses (841 ± 173) was significantly higher (P < 0.05) than that of culture-positive abscesses (536 ± 90). On multivariable analysis, mean ADC was the only significant factor (P < 0.05) related to culture yields. With 660 as the cutoff value, the sensitivity, specificity, and accuracy of ADC for discriminating culture yields were 93.2%, 88.0%, and 91.7%, respectively.
ADC could be used to discriminate between culture-positive and culture-negative abscesses.
4 TECHNICAL EFFICACY: Stage 2.
获取脓液进行微生物培养是脑脓肿患者的手术目标之一。微生物产量的预测因素是必要的，因为它们有助于治疗计划。
研究脑脓肿的微生物培养产量与其表观扩散系数（ADC）值和临床特征之间的关系。
回顾性。
84 名经手术和组织病理学诊断为脑脓肿的患者（59 名脓肿培养阳性）。
磁场强度/序列：1.5T 和 3T 下的弥散加权、T2 加权和对比增强 T1 加权成像。
对比增强 T1 加权图像与 ADC 图配准。三位神经放射科医生确定脓肿的影像学特征（分布、位置和脑室破裂），两位医生测量脓肿体积和 ADC 值。收集的临床特征包括性别、年龄、发热、基础疾病、感染源、白细胞计数、分叶中性粒细胞百分比、C 反应蛋白水平、经验性抗生素的方案和疗程，以及手术类型。
采用 Fleiss kappa 和组内相关系数评估观察者间差异。比较培养阳性和培养阴性组之间的临床和影像学因素差异，采用卡方分析或学生 t 检验。将所有因素进行多变量逻辑回归分析，以评估其与微生物培养产量的关系，并对有统计学意义的因素进行受试者工作特征曲线分析，以评估其在区分两组方面的诊断性能。
培养阴性脓肿的平均 ADC（×10mm/s）（841±173）明显高于培养阳性脓肿（536±90）（P<0.05）。多变量分析显示，平均 ADC 是唯一与培养产量相关的显著因素（P<0.05）。以 660 为截断值，ADC 鉴别培养产量的灵敏度、特异度和准确度分别为 93.2%、88.0%和 91.7%。
ADC 可用于区分培养阳性和培养阴性脓肿。
4 级 技术功效：2 级。
