Reliability of the MRI‐based Brain Atrophy and Lesion Index in the evaluation of whole‐brain structural health

Abstract

BackgroundThe Brain Atrophy and Lesion Index (BALI), which evaluates several common aging‐related MRI changes in combination, has been validated as a feasible method to assess the status of structural brain health. Previous studies have been based primarily on older participants and high‐field MRI. Here, we tested the generalizability of the BALI by examining its measurement properties in a wide age range at both high and conventional MRI field strengths.MethodsSubjects (n = 229) who had T2WI at either 1.5T or 3.0T were grouped into younger (age ≤ 60 years) and older (age > 60 years) groups. Image evaluation and scoring were performed independently by two experienced neuroradiologists who have mastered the BALI method. Inter‐ and intrarater agreement rates were examined comparing age groups and field strengths.ResultsThe intraclass correlation coefficient for the BALI total score was consistently high under each experimental condition (interrater ICC ≥ 0.92, 95% CI: 0.84‐0.96), with no statistical difference between age groups (Fisher Z = 1.43) or field strengths (Z = 0.60). The reliability for BALI category subscores ranged between moderate and perfect (eg, 0.85 vs 0.57 for GA), similar for both age groups and typically greater at 3.0T than at 1.5T.ConclusionThe BALI based on T2WI can be reliably applied to the evaluation of the whole‐brain health of both younger and older adults at both field strengths, even though high‐field MRI is preferable.

Age-Related Whole-Brain Structural Changes in Relation to Cardiovascular Risks Across the Adult Age Spectrum

“…Given that DICOM is the default format with all MRI scanners, brain scans can be readily evaluated without the need for reformatting. Despite these limitations, in this study, the evaluation of BALI strictly followed standard procedures (Guo et al, 2014a) and, as demonstrated elsewhere, the resulting BALI scores showed great intra-rater and inter-rater reliability (Gu et al, 2018).…”

“…Given that high field strength can allow high signal-to-noise ratios and greater image contrast, it is not surprising that a significantly higher mean BALI total scores using 3.0T over 1.5T images (6.84 ± 3.28 vs.5.80 ± 2.92, t = 2.17, p = 0.031). On the other hand, the evaluation has been proven reliable (Gu et al, 2018) and data collection was not biased for field-strength, in terms of age and possession of the risk factors under study (e.g., mean age 48.77 ± 12.87 vs. 47.00 ± 11.41, t = 0.94, p = 0.348; mean number of risk factors 1.93 ± 1.18 vs. 1.78 ± 1.24, t = 0.85, p = 0.398). Previous studies have also demonstrated the reliability and comparability of both field strengths (Guo et al, 2014b; Gu et al, 2018).…”

“…Two experienced neuroradiologists (TG, HG) performed the evaluation independently, with the subjects’ demographic information masked. The first author, TG evaluated and scored all the images, and HG assessed a randomly selected 20% images to test interrater reliability of the rating, as reported elsewhere, together with estimates of intra-rater reliability (Gu et al, 2018).…”