Magnetic resonance spectroscopy and brain volumetry in mild cognitive impairment. A prospective study

Nicolás Fayed; Pedro J Modrego; Gracián García-Martí; Roberto Sanz-Requena; Luis Marti-Bonmatí

doi:10.1016/j.mri.2016.12.010

Magnetic resonance spectroscopy and brain volumetry in mild cognitive impairment. A prospective study

Magn Reson Imaging. 2017 May:38:27-32. doi: 10.1016/j.mri.2016.12.010. Epub 2016 Dec 11.

Authors

Nicolás Fayed¹, Pedro J Modrego², Gracián García-Martí³, Roberto Sanz-Requena⁴, Luis Marti-Bonmatí⁵

Affiliations

¹ Radiology Department, Quirón Hospital, Zaragoza 50009, Spain.
² Department of Neurology, Miguel Servet Hospital, Zaragoza 50009, Spain. Electronic address: pmodrego@salud.aragon.es.
³ Biomedical Engineering, Quirón Hospital, Valencia, Spain; CIBERSAM, Mental Research Network, Valencia, Spain.
⁴ Biomedical Engineering, Quirón Hospital, Valencia 46920, Spain.
⁵ Radiology Department, Quirón Hospital, Valencia 46920, Spain.

PMID: 27964994
DOI: 10.1016/j.mri.2016.12.010

Abstract

Objective: To assess the accuracy of magnetic resonance spectroscopy (1H-MRS) and brain volumetry in mild cognitive impairment (MCI) to predict conversion to probable Alzheimer's disease (AD).

Methods: Forty-eight patients fulfilling the criteria of amnestic MCI who underwent a conventional magnetic resonance imaging (MRI) followed by MRS, and T1-3D on 1.5 Tesla MR unit. At baseline the patients underwent neuropsychological examination. 1H-MRS of the brain was carried out by exploring the left medial occipital lobe and ventral posterior cingulated cortex (vPCC) using the LCModel software. A high resolution T1-3D sequence was acquired to carry out the volumetric measurement. A cortical and subcortical parcellation strategy was used to obtain the volumes of each area within the brain. The patients were followed up to detect conversion to probable AD.

Results: After a 3-year follow-up, 15 (31.2%) patients converted to AD. The myo-inositol in the occipital cortex and glutamate+glutamine (Glx) in the posterior cingulate cortex predicted conversion to probable AD at 46.1% sensitivity and 90.6% specificity. The positive predictive value was 66.7%, and the negative predictive value was 80.6%, with an overall cross-validated classification accuracy of 77.8%. The volume of the third ventricle, the total white matter and entorhinal cortex predict conversion to probable AD at 46.7% sensitivity and 90.9% specificity. The positive predictive value was 70%, and the negative predictive value was 78.9%, with an overall cross-validated classification accuracy of 77.1%. Combining volumetric measures in addition to the MRS measures the prediction to probable AD has a 38.5% sensitivity and 87.5% specificity, with a positive predictive value of 55.6%, a negative predictive value of 77.8% and an overall accuracy of 73.3%.

Conclusion: Either MRS or brain volumetric measures are markers separately of cognitive decline and may serve as a noninvasive tool to monitor cognitive changes and progression to dementia in patients with amnestic MCI, but the results do not support the routine use in the clinical settings.

Keywords: Alzheimer's disease; Brain volumetry; Magnetic resonance spectroscopy; Mild cognitive impairment.

MeSH terms

Aged
Brain / diagnostic imaging*
Brain / pathology*
Brain Mapping / methods
Cognitive Dysfunction / diagnostic imaging*
Cognitive Dysfunction / pathology*
Female
Follow-Up Studies
Humans
Magnetic Resonance Spectroscopy / methods*
Male
Organ Size
Prospective Studies
Reproducibility of Results
Sensitivity and Specificity