Department of Radiology, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA.
Radiology. 2011 Jun;259(3):834-43. doi: 10.1148/radiol.11101975. Epub 2011 Apr 6.
To assess whether single-time-point and longitudinal volumetric magnetic resonance (MR) imaging measures provide predictive prognostic information in patients with amnestic mild cognitive impairment (MCI).
This study was conducted with institutional review board approval and in compliance with HIPAA regulations. Written informed consent was obtained from all participants or the participants' legal guardians. Cross-validated discriminant analyses of MR imaging measures were performed to differentiate 164 Alzheimer disease (AD) cases from 203 healthy control cases. Separate analyses were performed by using data from MR images obtained at one time point or by combining single-time-point measures with 1-year change measures. Resulting discriminant functions were applied to 317 MCI cases to derive individual patient risk scores. Risk of conversion to AD was estimated as a continuous function of risk score percentile. Kaplan-Meier survival curves were computed for risk score quartiles. Odds ratios (ORs) for the conversion to AD were computed between the highest and lowest quartile scores.
Individualized risk estimates from baseline MR examinations indicated that the 1-year risk of conversion to AD ranged from 3% to 40% (average group risk, 17%; OR, 7.2 for highest vs lowest score quartiles). Including measures of 1-year change in global and regional volumes significantly improved risk estimates (P = 001), with the risk of conversion to AD in the subsequent year ranging from 3% to 69% (average group risk, 27%; OR, 12.0 for highest vs lowest score quartiles).
Relative to the risk of conversion to AD conferred by the clinical diagnosis of MCI alone, MR imaging measures yield substantially more informative patient-specific risk estimates. Such predictive prognostic information will be critical if disease-modifying therapies become available.
http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101975/-/DC1.
评估单次时间点和纵向容积磁共振（MR）成像测量值是否为遗忘型轻度认知障碍（MCI）患者提供预测预后信息。
本研究经机构审查委员会批准，并符合 HIPAA 法规。所有参与者或其法定监护人都签署了书面知情同意书。对 MR 成像测量值进行交叉验证判别分析，以区分 164 例阿尔茨海默病（AD）病例和 203 例健康对照病例。分别对单次时间点的 MRI 数据或单次时间点测量值与 1 年变化测量值相结合进行分析。将得出的判别函数应用于 317 例 MCI 病例，得出每位患者的风险评分。将 AD 转化率的风险估计为风险评分百分位数的连续函数。为风险评分四分位数计算 Kaplan-Meier 生存曲线。计算最高和最低四分位数评分之间 AD 转化率的比值比（OR）。
基于基线 MR 检查的个体化风险估计表明，1 年内 AD 转化率的范围为 3%至 40%（平均组风险为 17%；最高与最低四分位数评分之间的 OR 为 7.2）。纳入 1 年的全球和区域容积变化测量值可显著改善风险估计（P = 0.001），随后 1 年内 AD 的转化率范围为 3%至 69%（平均组风险为 27%；最高与最低四分位数评分之间的 OR 为 12.0）。
与单纯 MCI 临床诊断所带来的 AD 转化率风险相比，MR 成像测量值提供了更具信息量的患者特定风险估计。如果出现疾病修饰疗法，这种预测预后信息将至关重要。
http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101975/-/DC1.
