Normal Appearing and Diffusely Abnormal White Matter in Patients with Multiple Sclerosis, Assessed with Quantitative MR : Optimization for clinical usage

• Introduction: Magnetic Resonance Imaging is a sensitive technique for detecting white matter (WM) MS lesions, but the relation with clinical disability is low. Because of this, changes in both ‘normal appearing white matter’ (NAWM) and ‘diffusely abnormal white matter’ (DAWM) have been of interest in recent years. MR techniques, including quantitative magnetic resonance imaging (qMRI) and quantitative magnetic resonance spectroscopy (qMRS), have been developed in order to detect and  quantify such changes.In this study, a combination of qMRI and qMRS was used to investigate NAWM and DAWM in typical MS patients and in MS patients with low number of WM lesions. Patient data were compared to ‘normal white matter’ (NWM) in healthy controls.Methods: QMRI and qMRS measurements were performed on a 1.5T Philips MR-scanner. 35 patients with clinically definite MS and 20 healthy controls were included. Fifteen of the patients showed few WM lesions (‘MRIneg‘) and 20 showed radiologically typical findings (‘MRIpos’). QMRI properties were determined in ROIs of NAWM, DAWM and WM lesions in the MS groups and of NWM in controls. Descriptive statistical analysis and comparisons were performed. Correlations were calculated between qMRI measurements and (1) clinical parameters and (2) WM metabolite concentrations. Regression analyses were performed with brain parenchyma fraction and MSSS.Results: NAWM in the MRIneg group was significantly different from NAWM in the MRIpos group and NWM. In addition, R1 and R2 of NAWM in the MRIpos group correlated negatively with EDSS and MSSS. DAWM was significantly different from NWM, but similar in the two MS groups. N-acetyl aspartate correlated negatively with R1 and R2 in MRIneg. Finally, R2 of DAWM was associated with BPF.Conclusions: Changes in NAWM and DAWM are independent pathological entities in the disease. Combined qMRI and qMRS measurements of NAWM and DAWM provide important markers for disease status.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Radiologi och bildbehandling (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Radiology, Nuclear Medicine and Medical Imaging (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Neurologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Neurology (hsv//eng)

Keyword

Multiple Sclerosis

Quantitative MRI

Quantitative MRS

QMRI

MRS

MEDICINE

MEDICIN

Publication and Content Type

ref (subject category)

art (subject category)