Effects of gadolinium contrast agent administration on automatic brain tissue classification of patients with multiple sclerosis.
OBJECTIVE
The administration of gadolinium contrast agent is a common part of MR imaging examinations in patients with MS. The presence of gadolinium may affect the outcome of automated tissue classification. The purpose of this study was to investigate the effects of the presence of gadolinium on the automatic segmentation in patients with MS by using the synthetic tissue-mapping method.


METHODS
A cohort of 20 patients with clinically definite multiple sclerosis were recruited, and the T1 and T2 relaxation times and proton density were simultaneously quantified before and after the administration of gadolinium. Synthetic tissue-mapping was used to measure white matter, gray matter, CSF, brain parenchymal, and intracranial volumes. For comparison, 20 matched controls were measured twice, without gadolinium.


RESULTS
No differences were observed for the control group between the 2 measurements. For the MS group, significant changes were observed pre- and post-gadolinium in intracranial volume (-13 mL, P < .005) and cerebrospinal fluid volume (-16 mL, P < .005) and the remaining, unclassified non-WM/GM/CSF tissue volume within the intracranial volume (+8 mL, P < .05). The changes in the patient group were much smaller than the differences, compared with the controls, which were -129 mL for WM volume, -22 mL for GM volume, +91 mL for CSF volume, 24 mL for the remaining, unclassified non-WM/GM/CSF tissue volume within the intracranial volume, and -126 mL for brain parenchymal volume. No significant differences were observed for linear regression values against age and Expanded Disability Status Scale.


CONCLUSIONS
The administration of gadolinium contrast agent had a significant effect on automatic brain-tissue classification in patients with MS by using synthetic tissue-mapping. The observed differences, however, were much smaller than the group differences between MS and controls.
From the Center for Medical Image Science and Visualization, (J.B.M.W., A.T., P.L.)Clinical Physiology (J.B.M.W.)Departments of Clinical Physiology (J.B.M.W.) marcel.warntjes@cmiv.liu.se.
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Warntjes
From the Center for Medical Image Science and Visualization, (J.B.M.W., A.T., P.L.)Radiation Physics (A.T.), Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
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Tisell
Clinical Neuroscience (A.-M.L.)Neurology, Department of Clinical and Experimental Medicine (A.-M.L.), Linköping University, Linköping, Sweden.
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Landtblom
From the Center for Medical Image Science and Visualization, (J.B.M.W., A.T., P.L.)Radiation Physics (P.L.), Department of Medical and Health Sciences, Linköping University, Linköping, SwedenRadiation Physics (P.L.), UHL, County Council of Östergötland, Linköping, Sweden.
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Lundberg
D001921:Brain / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D066128:Gray Matter / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology*; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D066127:White Matter / Q000473:pathology*
D003287:Contrast Media; D019786:Gadolinium DTPA