Applications Of Diffusion Tensor Magnetic Resonance Imaging In Multiple Sclerosis

Objectives: This study analyzed the DTI imaging features of MS in different stages oflesions, optic nerves, optic radiations after optic neuritis, normal-appearing white matter,normal-appearing deep gray matter by using3.0T magnetic resonance imaging which canprovide strong evidence for the early diagnosis, treatment and prognosis of MS.Materials and Methods: This study recruited10neurological department MS patientsof Jilin University Bethune first hospital in2011September to2012June who wereaccording to the diagnostic criteria of McDonald. There were10age-and sex-matchedhealthy volunteers. The clinical relevant data including sex, age, signs, disease duration, Therecurrence of the disease history, he history of optic neuritis, brain MRI, brain enhancedMRI and brain DTI. In this study, the patients of MS were divided into4parts for analysisand comparison with the normal control groups.1. The comparison of MS silent lesions, subacute lesions, normal-appearing white matter(NAWM) and normal control groups were made.2. The comparison of MS thalamus, caudate nucleus, deep gray matter and normal controlgroups were made.3. The comparison of MS optic nerves after optic neuritis, optic nerves of unaffected opticneuritis and normal control groups were made.4. The comparison of MS optic radiations of optic nerves after optic neuritis, optic radiationsof unaffected optic neuritis and normal control groups were made.All subjects were imaged using a Siemens3.0T Trio Tim MRI system (Siemens,Erlangen, Germany). Statistical analysis was performed by using the SPSS17.0Windowssoftware package. All data were record as mean±standard deviation, statistical significancelevel was set as a=0.05，significant difference was defined as p＜0.05．Results:1.1FA value, λ∥value of silent lesions and subacute lesions were lower than NAWM andnormal control groups. MD value and λ⊥value is higher than NAWM and normal controlgroups. FA value is reduced and MD value, λ∥value, λ⊥value were increased in NAWMthan the normal control groups. Silent lesions and subacute lesions in the value comparison had no significant difference (p＞0.05). The comparision of Static lesions λ∥value, NAWMand normal control groups had no clearly difference. There was no obvious differencebetween Subacute lesions, NAWM and normal control in MD value. The size of lesions onFA and DEC maps wag increased compared with that on conventional MRI. Disruption offiber Disruption and reduce of fiber pathway in MS lesions were detected on DTT maps.2.1FA value, MD value, λ∥value and λ⊥value in MS thalamic were increased comparedto normal thalamus, MD value and λ∥value revealed progressively difference. Caudatenucleus, deep gray matter in MS com pared with normal control groups, lower FA value andhigher MD value, λ∥value and λ⊥value were existed. MS caudate nucleus and normalcontrol groups in the FA values showed clearly difference(p＜0.05). MS deep gray matterand normal deep gray matter in λ∥value, λ⊥value showed clearly difference(p＜0.05).3.1Affected optic nerves after optic neuritis and unaffected optic nerves after optic neuritisshowed lower FA value and higher MD value, λ∥value, λ⊥value than normal controlgroups(p＜0.05). The difference between affected optic nerves after optic neuritis withunaffected optic nerves after optic neuritis was no found. In10MS patients, there were7affected optic nerves and13unaffected optic nerves. Enlargement and abnormal increasedsignals of the optic nerves by brain MRI in2MS patients were detected.The green signalwere decreased in DEC maps of3cases.4.1Optic radiations of affected optic nerves after optic neuritis and optic radiation ofunaffected optic nerves after optic neuritis in FA value were increased than normal controlgroups, MD value were reduced (p＜0.05).There was no obvious difference between opticradiations of affected optic nerves after optic neuritis and optic radiation of unaffected opticnerves after optic neuritis（p＞0.05）.Conclusion:(1) The silent lesions and subacute lesions of MS have been found axonal damage anddemyelination, remyelination of MS damaged tissue have been found.(2) The size of lesions on FA and DEC maps wag increased compared with that onconventional MRI. Disruption and reduction of fiber pathway in MS lesions were detectedon DTT maps.(3) Affected optic nerves after optic neuritis and unaffected optic nerves after optic neuritisin remission stage may exist demyelination and axonal damage at the same time,opticradiation of affected optic nerves after optic neuritis was associated with trans-synaptic degeneration occurs.(4) NAWM, deep gray matter, unaffected optic nerves and unaffected optic radiations in MSexisted potential damage. DTI have more heigher sensitivity.