Predictive Utility of Marketed Volumetric Software Tools in Subjects at Risk for Alzheimer Disease: Do Regions Outside the Hippocampus Matter?

• Published in: American journal of neuroradiology : AJNR Vol. 38; no. 3; pp. 546 - 552
• Main Authors: Tanpitukpongse, T.P., Mazurowski, M.A., Ikhena, J., Petrella, J.R.
• Format: Journal Article
• Language: English
• Published: United States American Society of Neuroradiology 01.03.2017
• Subjects: Adult Brain; Aged; Aged, 80 and over; Alzheimer Disease - diagnostic imaging; Alzheimer Disease - pathology; Alzheimer's disease; Atrophy; Atrophy - diagnostic imaging; Atrophy - pathology; Biomarkers; Brain; Cognitive ability; Cognitive Dysfunction - pathology; Computer programs; Conversion; Demographics; Disease Progression; Editor's Choice; Effectiveness; Female; Health risks; Hippocampus; Hippocampus - diagnostic imaging; Hippocampus - pathology; Humans; Impairment; Logistic Models; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Medical imaging; Neurodegenerative diseases; Neuroimaging; Neurology; Patients; Regional analysis; Regression analysis; ROC Curve; Software; Software development tools; Software packages
• DOI: 10.3174/ajnr.A5061
• ISSN: 0195-6108; 1936-959X

Alzheimer disease is a prevalent neurodegenerative disease. Computer assessment of brain atrophy patterns can help predict conversion to Alzheimer disease. Our aim was to assess the prognostic efficacy of individual-versus-combined regional volumetrics in 2 commercially available brain volumetric software packages for predicting conversion of patients with mild cognitive impairment to Alzheimer disease. Data were obtained through the Alzheimer's Disease Neuroimaging Initiative. One hundred ninety-two subjects (mean age, 74.8 years; 39% female) diagnosed with mild cognitive impairment at baseline were studied. All had T1-weighted MR imaging sequences at baseline and 3-year clinical follow-up. Analysis was performed with NeuroQuant and Neuroreader. Receiver operating characteristic curves assessing the prognostic efficacy of each software package were generated by using a univariable approach using individual regional brain volumes and 2 multivariable approaches (multiple regression and random forest), combining multiple volumes. On univariable analysis of 11 NeuroQuant and 11 Neuroreader regional volumes, hippocampal volume had the highest area under the curve for both software packages (0.69, NeuroQuant; 0.68, Neuroreader) and was not significantly different ( > .05) between packages. Multivariable analysis did not increase the area under the curve for either package (0.63, logistic regression; 0.60, random forest NeuroQuant; 0.65, logistic regression; 0.62, random forest Neuroreader). Of the multiple regional volume measures available in FDA-cleared brain volumetric software packages, hippocampal volume remains the best single predictor of conversion of mild cognitive impairment to Alzheimer disease at 3-year follow-up. Combining volumetrics did not add additional prognostic efficacy. Therefore, future prognostic studies in mild cognitive impairment, combining such tools with demographic and other biomarker measures, are justified in using hippocampal volume as the only volumetric biomarker.