Magnetization Transfer Imaging Of The Spinal Cord And The Optic Nerve In Multiple Sclerosis
van Waesberghe JH, Barkhof F
Neurology 1999;53(5 Suppl 3):S46-8
MR Centre for MS Research, Academic Hospital Vrije Universiteit, Dept of Radiology, Amsterdam, The Netherlands
PMID# 10496211; UI# 99424530
Magnetization Transfer (MT) imaging has been successfully applied to patients with Multiple Sclerosis (MS), showing lesion heterogeneity, subtle changes in the Normal-Appearing White Matter, and a better correlation with disability, in comparison with conventional Magnetic Resonance Imaging.
MT imaging is a fairly simple technique, which allows a quantitative analysis with high spatial resolution to delicate structures like the Optic Nerve and Spinal Cord.
In the Spinal Cord, MT imaging can be applied as a contrast augmentation technique.
Using the MT Ratio (MTR), two studies have reported a mild, but significant, reduction in MT Ratio in the Cervical Spinal Cord, compared with healthy controls.
In one study, clinical disability correlated independently of Cord Atrophy with MTR, which may relate to preliminary findings of a correlation between Axonal loss and MTR in the Spinal Cord.
In the Optic Nerve, two studies reported strongly decreased MTR in affected Nerves, even in the absence of lesions on conventional imaging; unaffected Nerves showed values similar to White Matter in the Brain.
In one study, MTR was significantly correlated with ElectroPhysiological parameters, but not with Vision.
In conclusion, MT imaging provides a quantifiable parameter that can be applied with high spatial resolution to delicate structures, such as the Spinal Cord and the Optic Nerve.
Further work is needed to correlate MTR measurements with pathology and, most importantly, with the functional status.
Such relationships being established, a quantitative technique such as MTR could be useful in monitoring disease progression in MS.
A Longitudinal MR Study Of The Presymptomatic Phase In A Patient With Clinically Definite Multiple Sclerosis
Mastronardo G, Rocca MA, Iannucci G, Pereira C, Filippi M
AJNR Am J NeuroRadiol 1999 Aug;20(7):1268-72
Scientific Institute, Ospedale San Raffaele, University of Milan, Department of NeuroScience, Italy
PMID# 10472984; UI# 99399963
We describe the dynamics and the nature of the presymptomatic phase of Multiple Sclerosis (MS) in a patient for whom MR abnormalities suggestive of MS were found before the development of clinical symptoms.
The patient was monitored with serial monthly MR imaging of the Brain and Spinal Cord for 5 months.
Disease activity during the presymptomatic phase showed imaging characteristics comparable to that of early Relapsing/Remitting MS in terms of enhancing lesions, duration of enhancement, and new lesions depicted by T2 weighted imaging.
Measurements derived from Magnetization Transfer imaging suggested that the amount and degree of tissue destruction within and outside the lesions revealed by T2 weighted imaging were mild.
This, together with the fact that only one of the 43 new lesions that developed during the presymptomatic phase was located in a Neurologically eloquent area.
May be the reason why, for a relatively long period, the patient had no clinical manifestations of MS despite the marked MR findings of disease activity.
Asymptomatic Spinal Cord Lesions In Clinically Isolated Optic Nerve, BrainStem, And Spinal Cord Syndromes Suggestive Of DeMyelination
O'Riordan JI, Losseff NA, Phatouros C, Thompson AJ, Moseley IF, MacManus DG, McDonald WI, Miller DH
J Neurol NeuroSurg Psychiatry 1998 Mar;64(3):353-7
The Institute of Neurology, NMR Research Unit, London, UK
PMID# 9527148; UI# 98186378
Conventional T1 weighted MRI studies have highlighted the fact that the presence of clinically silent Brain lesions increases the risk of developing Clinically Definite Multiple Sclerosis after an Isolated Syndrome of the Optic Nerve, BrainStem, or Spinal Cord.
The objectives of the present study are to:
- Show whether or not these patients also have asymptomatic abnormalities of the Spinal Cord, and
- Recruit a new cohort of such patients using high resolution MRI of both Brain and Spinal Cord
The Brain was imaged in the Axial plane with 3 mm thick contiguous slices using a Proton Density and T2 weighted Fast Spin Echo (FSE) sequence; a T2 weighted sequence after the injection of Gadolinium-DTPA; and a fast Fluid Attenuated Inversion Recovery (FLAIR) sequence.
The Spinal Cord was imaged in the Sagittal plane with 3 mm thick slices using a T2 weighted FSE and a T1 weighted Gadolinium enhanced sequence.
Thirty three patients, mean age 31 (16-46) were recruited. There were 14 men and 19 women.
Brain MRI was abnormal in 22 (67%); no patient was seen with abnormalities on only one or other sequence. Six patients (18%) displayed one or more Gadolinium enhancing lesions on Brain MRI.
In the Spinal Cord, nine (27%) patients displayed one or more Clinically Silent lesions on FSE. Two patients showed one and two Gadolinium enhancing lesions in the Spinal Cord respectively.
This high incidence of Spinal Cord lesions emphasizes that asymptomatic DeMyelinating lesions may also involve clinically eloquent pathways. Follow up studies are required to determine their prognostic importance.
Multiple Sclerosis Of The Spinal Cord: Diagnosis And Follow-Up With Contrast-Enhanced MR And Correlation With Clinical Activity
Trop I, Bourgouin PM, Lapierre Y, Duquette P, Wolfson CM, Duong HD, Trudel GC
AJNR Am J NeuroRadiol 1998 Jun-Jul;19(6):1025-33
University of Montreal Medical Center, Department of Radiology, Canada
PMID# 9672006; UI# 98335727
Although MR findings in Multiple Sclerosis (MS) are well known, the relationship between MR-detected lesions and clinical activity has not been studied in the Spinal Cord.
The purpose of this study was to determine whether serial MR imaging provides evidence of disease activity unsuspected on clinical examination and to determine whether it is useful in monitoring patients with MS primarily affecting the Spinal Cord.
Twenty-five consecutive patients with MS and with signs and symptoms of myelopathy underwent a full Neurologic Examination and contrast-enhanced MR imaging of the spinal cord at intervals of 0, 2, 6, and 12 months.
Disability was rated according to Kurtzke's Functional Systems and the Expanded Disability Status Scale (EDSS). Clinical status of Myelopathy (improved, deteriorated, or stable) was also assessed.
HyperIntense lesions were counted on T2-weighted images and a weighted lesion load was calculated for each patient. The number of enhancing lesions was also determined.
We found a moderate correlation between Lesion Load and Sensory Function and EDSS. Seventy percent of patients with new clinical manifestations of Myelopathy had one or more enhancing lesions.
Agreement between MR findings and clinical examination in evincing disease activity was found in 60% of follow-up examinations.
MR images showed lesion progression in seven (44%) of 16 occurrences of clinical deterioration and in 21 (35%) of 60 occurrences of clinical improvement or stability.
Serial MR imaging provides evidence of disease activity unsuspected on clinical examination and could be useful in monitoring patients with MS primarily affecting the Spinal Cord.