Related Experiment Videos
Intraobserver and interobserver variability in measuring changes in lesion volume on serial brain MR images in
M Filippi1, M Rovaris, M P Sormani
1Department of Neurology, MS Biosignal Analysis Center, Scientific Institute Ospedale S. Raffaele, University of Milan, Italy.
Purpose:
We evaluated the intraobserver and interobserver variability in measuring long-term changes in the volume of brain lesions on 5- and 3-mm-thick MR sections in patients with multiple sclerosis.
Methods:
Eighteen 18 patients were scanned on two separate occasions with a mean interval of 16.4 months between the two examinations. In each session, a scan with 24 contiguous 5-mm-thick axial sections and another with 40 contiguous 3-mm-thick axial sections was acquired consecutively without moving the patient. We assessed MR lesion load by using a semiautomated local thresholding technique.
Results:
Lesion volume was significantly higher on images with 3-mm-thick sections than on those with 5-mm-thick sections both at baseline and at follow up. Significant increases in total lesion volume were observed during the follow-up period on images obtained with both 5- and 3-mm-thick sections. The intra- and interobserver variability in measurements of changes in lesion volume was significantly higher on images with 5-mm-thick sections than on those with 3-mm-thick sections.
Conclusion:
Our data indicate that the acquisition of thinner sections increases the reliability of the assessment of changes in brain lesion load on MR images in patients with multiple sclerosis.