Friday, September 28, 2018 1:00 PM–2:30 PM abstracts: a new look at imaging: 202. The Functional relevance of diffusion tensor imaging in comparison to conventional MRI in patients with cervical compressive myelopathy

Abstract

BACKGROUND CONTEXT Most of cervical myelopathy are easily diagnosed by conventional T2-weighted magnetic resonance imaging together with a history of specific symptoms and neurological examinations. Although MRI has played an important role in the diagnosis and follow-up of spinal cord lesions at present, it still lacks relevance to the functional outcome and prognosis. A recently introduced technique, diffusion tensor imaging (DTI), has been investigated for estimating the neural tissue integrity in the brain and spinal cord. It would be important to validate the advantage of DTI in terms of functional relevance compared to conventional MRI. PURPOSE To determine the functional relevance of diffusion tensor imaging (DTI) metrics and conventional MRI (signal intensity change in T2, compression ratio) by measuring the correlation of these parameters with clinical outcome measured by the modified Japanese Orthopedic Association (mJOA) score. STUDY DESIGN/SETTING This is a prospective cohort study. PATIENT SAMPLE A total of 20 cervical myelopathy (CM) patients participated. OUTCOME MEASURES The mJOA score, Conventional MRIs (T2-weighted images) and DTI metrics [fractional anisotropy (FA), apparent diffusion coefficient (ADC)] at each lesion and below each lesion (C7/T1) level were acquired using a 3-T Achieva MRI. METHODS Conventional MRIs abd DTI metrics parameters were correlated with the mJOA scores to determine the functional relevance. RESULTS Ninety percent of CM patients showed signal changes and 30% of patients noted a more than 40% canal compression ratio in conventional MRIs at the lesion level; however, these findings were not correlated with the mJOA score (p<.05). In contrast, FA values on DTI showed high sensitivity to CM (100%), which was well correlated with the mJOA score (p=.034, r=0.475) below the lesion level (C7/T1). CONCLUSIONS This study showed a meaningful symptomatic correlation between mJOA scores and FA values below the lesion levels in CMpatients. It could give us more understanding of the pathological changes in spinal cords matched with various clinical findings in CM patients than the results from conventional MRI. Most of cervical myelopathy are easily diagnosed by conventional T2-weighted magnetic resonance imaging together with a history of specific symptoms and neurological examinations. Although MRI has played an important role in the diagnosis and follow-up of spinal cord lesions at present, it still lacks relevance to the functional outcome and prognosis. A recently introduced technique, diffusion tensor imaging (DTI), has been investigated for estimating the neural tissue integrity in the brain and spinal cord. It would be important to validate the advantage of DTI in terms of functional relevance compared to conventional MRI. To determine the functional relevance of diffusion tensor imaging (DTI) metrics and conventional MRI (signal intensity change in T2, compression ratio) by measuring the correlation of these parameters with clinical outcome measured by the modified Japanese Orthopedic Association (mJOA) score. This is a prospective cohort study. A total of 20 cervical myelopathy (CM) patients participated. The mJOA score, Conventional MRIs (T2-weighted images) and DTI metrics [fractional anisotropy (FA), apparent diffusion coefficient (ADC)] at each lesion and below each lesion (C7/T1) level were acquired using a 3-T Achieva MRI. Conventional MRIs abd DTI metrics parameters were correlated with the mJOA scores to determine the functional relevance. Ninety percent of CM patients showed signal changes and 30% of patients noted a more than 40% canal compression ratio in conventional MRIs at the lesion level; however, these findings were not correlated with the mJOA score (p<.05). In contrast, FA values on DTI showed high sensitivity to CM (100%), which was well correlated with the mJOA score (p=.034, r=0.475) below the lesion level (C7/T1). This study showed a meaningful symptomatic correlation between mJOA scores and FA values below the lesion levels in CMpatients. It could give us more understanding of the pathological changes in spinal cords matched with various clinical findings in CM patients than the results from conventional MRI.