Agreement and Comparative Performance of Cognitive Testing, Visual MRI Rating, and Automated Brain Morphometry in Older Adults with Suspected Dementia in Uganda

Rita Nassanga,1 Mark Kaddumukasa,2 Stephen E Jones,3 Martha Sajatovic,4 Ajay Nemani,5 Roy Clark Basiimwa,6 Michael Grace Kawooya,7 James K Tumwine,8 Kamada Lwere,9 Joy Louise Gumikiriza-Onoria,10 Aloysius Gonzaga Mubuuke,1 Noeline Nakasujja10 1Department of Radiology, Makerere University, College of Health Sciences, Kampala, Uganda; 2Department of Internal Medicine, Makerere University, College of Health Sciences, Kampala, Uganda; 3Department of Neuroradiology, Cleveland Clinic, Lerner College of Medicine, Cleveland, OH, USA; 4Department of Psychiatry, Case Western Reserve University School of Medicine, Cleveland, OH, USA; 5Department of Radiology, Imaging Institute, Cleveland Clinic, Mellen Center, Cleveland, OH, USA; 6Department of Radiology, St Francis Hospital Nsambya, Kampala, Uganda; 7Department of Radiology, Ernest Cook University, Kampala, Uganda; 8Department of Paediatrics and Child Health, Kabale University, School of Medicine, Kabale, Uganda; 9Department of Microbiology, Soroti University, Faculty of Health Sciences, Soroti, Uganda; 10Department of Psychiatry, Makerere University, College of Health Sciences, Kampala, UgandaCorrespondence: Rita Nassanga, Department of Radiology, Makerere University, College of Health Sciences, Kampala, Uganda, Tel +256774280446, Email [email protected]: Dementia diagnosis in sub-Saharan Africa is constrained by limited access to specialist neuroimaging interpretation and reduced specificity of brief cognitive tools in low-literacy populations. We evaluated the agreement, incremental value, and comparative performance of Mini Mental State Exam (MMSE), visual MRI medial temporal atrophy (MTA), and automated brain morphometry in older Ugandan adults with suspected dementia.Methods: In this cross-sectional study, adults aged ≥ 50 years with suspected dementia were recruited from neurology and psychiatry clinics at two hospitals and from a community cohort. Participants underwent MMSE and standardized 1.5T brain MRI. Visual MRI ratings were performed by radiologists blinded to clinical data, and automated morphometry was generated using NeuroQuant® normative percentiles. Hippocampal occupancy (HOC < 5th percentile) was used as a reference MRI biomarker for comparative classification. Agreement between visual and automated measures was assessed using Spearman correlation and intraclass correlation. Incremental value was assessed using regression models, and comparative performance using area under the curve (AUC).Results: Sixty-three participants were included (mean age 75.6 ± 8.7 years; 49 female). Agreement between visual ratings and automated morphometry was poor. MMSE correlated inversely with MTA (ρ = − 0.47; p = 0.049) and correlated positively with hippocampal volume percentile (ρ = 0.46; p = 0.056). Adding hippocampal volume to MTA did not improve model fit for MMSE (ΔR2 = 0.028; p = 0.18). For comparative classification, MMSE alone was sensitive but poorly specific, while the combined MMSE-MTA model improved specificity and discrimination (AUC 0.70 vs 0.62 for either measure alone).Conclusion: Visual and automated MRI measures were not interchangeable in this heterogeneous cohort. Automated hippocampal volumetry added limited value beyond visual MTA for global cognition, while combining MMSE with visual MTA showed modest improvement in comparative classification and warrants further validation.Keywords: dementia, MMSE, medial temporal atrophy, visual MRI rating, automated brain volumetric analysis software, hippocampal occupancy, automated morphometry