Abstract
Changes in mean magnetic resonance imaging (MRI)-derived measurements between patient groups are often used to determine outcomes in therapeutic trials and other longitudinal studies of multiple sclerosis (MS). However, in day-to-day clinical practice the changes within individual patients may also be of interest. In this paper, we estimated the measurement error of an automated brain tissue quantification algorithm and determined the thresholds for statistically significant change of MRI-derived T2 lesion volume and brain atrophy in individual patients. Twenty patients with MS were scanned twice within 30 min. Brain tissue volumes were measured using the computer algorithm. Brain atrophy was estimated by calculation of brain parenchymal fraction. The threshold of change between repeated scans that represented statistically significant change beyond measurement error with 95% certainty was 0.65 mL for T2 lesion burden and 0.0056 for brain parenchymal fraction. Changes in lesion burden and brain atrophy below these thresholds can be safely (with 95% certainty) explained by measurement variability alone. These values provide clinical neurologists with a useful reference to interpret MRI-derived measures in individual patients.
Original language | English (US) |
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Pages (from-to) | 402-406 |
Number of pages | 5 |
Journal | Multiple Sclerosis |
Volume | 10 |
Issue number | 4 |
DOIs | |
State | Published - Aug 2004 |
Keywords
- Brain atrophy
- Computer-assisted
- Image processing
- Magnetic resonance imaging
- Multiple sclerosis
ASJC Scopus subject areas
- Neurology
- Clinical Neurology