Cervical Spinal Cord In Patients Research Articles

Can Qualitative Cervical Tractography Predict Clinical Findings as Effectively as It Aids Surgical Planning Today?

To investigate cervical spinal tractography (CST) and diffusion tensor imaging findings in patients with intramedullary cervical spinal cord (CSC) tumors and to evaluate the association between qualitative diffusion tensor tractography (DTT) findings and neurological examination findings (NEF). Neuroradiology case records were retrospectively evaluated to identify patients with intramedullary CSC tumors who underwent cervical spinal DTT. Conventional magnetic resonance imaging (MRI) and DTT were performed using a 3.0-T MRI system. Demographic data, CST and clinical findings, fractional anisotropy (FA), and apparent diffusion coefficient (ADC) were recorded. The sensitivity, specificity, and positive and negative predictive values (PPV and NPV, respectively) were calculated. This study enrolled 31 patients (16 women and 15 men) with a mean age of 35.2 ± 15.6 years (range: 1-70 years). The mean FA and ADC were 0.34 ± 0.45 and 1.88 ± 0.89, respectively. Physical examination revealed hemihypesthesia (19.3%), hemiparesis (16.1%), and quadriparesis (3.2%). Completely normal neurological findings were observed in 61.3% of the patients. DTT revealed deviation (n=15), deformation (n=11), and interruption (n=5) of the fibers. No significant relationship was observed between NEF and DTT findings (p=0.127). The sensitivity, specificity, PPV, and NPV of DTT for CSC tracts were 100%, 0%, 38.7%, and 0%, respectively. Although qualitative DTT of the CSC might be useful for planning and preservation of the fiber tracts during intramedullary tumor surgery, it did not exhibit significant association with clinical findings in this study. Qualitative DTT of CSC in patients with intramedullary tumors may not correlate well with NEF.

Evaluation of (R)-[11C]PK11195 PET/MRI for Spinal Cord-Related Neuropathic Pain in Patients with Cervical Spinal Disorders

Activated microglia are involved in secondary injury after acute spinal cord injury (SCI) and in development of spinal cord-related neuropathic pain (NeP). The aim of the study was to assess expression of translocator protein 18 kDa (TSPO) as an indicator of microglial activation and to investigate visualization of the dynamics of activated microglia in the injured spinal cord using PET imaging with (R)-[11C]PK11195, a specific ligand for TSPO. In SCI chimeric animal models, TSPO was expressed mainly in activated microglia. Accumulation of (R)-[3H]PK11195 was confirmed in autoradiography and its dynamics in the injured spinal cord were visualized by (R)-[11C]PK11195 PET imaging in the acute phase after SCI. In clinical application of (R)-[11C]PK11195 PET/MRI of the cervical spinal cord in patients with NeP related to cervical disorders, uptake was found in cases up to 10 months after injury or surgery. No uptake could be visualized in the injured spinal cord in patients with chronic NeP at more than 1 year after injury or surgery, regardless of the degree of NeP. However, a positive correlation was found between standardized uptake value ratio and the severity of NeP, suggesting the potential of clinical application for objective evaluation of chronic NeP.

A long-term follow up study of cervical spondylotic myelopathy using diffusion tensor imaging

Objective: To analyze the correlation between the parameters of diffusion tensor imaging (DTI) and the clinical function scores before and 5 years after anterior cervical discectomy and fusion (ACDF) by measuring the DTI signal of the maximum compression level (MCL) of the cervical spinal cord in patients with cervical spondylotic myelopathy (CSM). Methods: A prospective study was conducted and clinical data of 37 patients with CSM treated by ACDF in Beijing Chaoyang Hospital from February 2014 to February 2020 were analyzed. The MCL was studied with diffusion tensor imaging (DTI) of MRI. The changes of diffusion indexes (fractional anisotropy (FA)), and clinical function score including Modified Japanese Orthopedic Association (mJOA), neck disability index (NDI) and visual analog scale (VAS) of pain were compared among each follow-up point. The FA value and clinical function score were collected and the data was analyzed to determine whether the high signal intensity could be observed in T2-weighted imaging (T2WI) at each follow-up point. The changes of preoperative and postoperative data were compared, and the correlation between FA value and other two clinical function score were analyzed at each follow-up point. Results: There were 14 males and 23 females with a mean age of (55±10) years in this study. All patients received the surgery and the medullary symptoms improved significantly postoperatively. After 3 months, the mJOA and FA value were improved by 2.62±1.41 and 0.14±0.11 on average, respectively (both P<0.05); and there were significant differences in these two indexes between each follow-up point in two years after the operation (all P<0.05). At the MCL, there were strong correlations between the FA value and mJOA score pre-and postoperatively (rs=0.770, 0.729, both P<0.01). There was no significant correlation between mJOA, NDI and VAS (both P>0.05). Conclusions: The DTI sensitively reflects the improvement of spinal cord function and can be used as an important tool to predict and evaluate the state of spinal cord dysfunction in patients with CSM.

Brain Stem Glucose Hypermetabolism in Amyotrophic Lateral Sclerosis/Frontotemporal Dementia and Shortened Survival: An 18F-FDG PET/MRI Study.

A few 18F-FDG PET/CT studies have revealed the presence of brain hypermetabolism in the brain stem and cervical spinal cord of patients within the amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) continuum. We aimed to investigate this finding through a hybrid PET/MRI system, allowing a more precise depiction of the spatial pattern of metabolic changes in the brain stem and cervical spinal cord. Methods: Twenty-eight patients with a diagnosis of ALS or a diagnosis of the behavioral variant of FTD plus motoneuron disease, as well as 13 control subjects, underwent 18F-FDG PET/MRI. Mean normalized 18F-FDG uptake in the midbrain/pons, medulla oblongata, and cervical spinal cord as defined on the individual's MRI scans were compared between groups. Furthermore, the associations between regional 18F-FDG uptake and clinical and demographic characteristics-including gene mutation, type of onset (bulbar, spinal, dementia), and clinical characteristics-were investigated. Results: A significant (P < 0.005) increment in glucose metabolism in the midbrain/pons and medulla oblongata was found in ALS/FTD patients (spinal-ALS and FTD-motor neuron disease subgroups) in comparison to controls. No relevant associations between clinical and metabolic features were reported, although medulla oblongata hypermetabolism was associated with shortened survival (P < 0.001). Conclusion: Increased glucose metabolism in the brain stem might be due to neuroinflammation, one of the key steps in the pathogenic cascade that leads to neurodegeneration in ALS/FTD. 18F-FDG PET/MRI could be a valuable tool to assess glial changes in the ALS/FTD spectrum and could serve as a prognostic biomarker. Large prospective initiatives would likely shed more light on the promising application of PET/MRI in this setting.

MR Diffusion Properties of Cervical Spinal Cord as a Predictor of Progression to Multiple Sclerosis in Patients with Clinically Isolated Syndrome.

This study's aim was to investigate diffusion properties of the cervical spinal cord in patients with clinically isolated syndrome (CIS) through analysis of diffusion tensor imaging (DTI) data and thereby to assess the capacity of this technique for predicting the progression of CIS to clinically definite multiple sclerosis (CDMS). The study groups were comprised of 47 patients with CIS (15 of them with progression to CDMS within 2 years of follow-up) and 57 asymptomatic controls. All patients and controls had undergone magnetic resonance imaging (MRI) of the cervical spine including DTI and brain MRI. Methodological approaches included histogram analysis of the cervical cord's diffusion parameters and evaluation of T2 hyperintense lesions of the spinal cord and brain. All parameters were compared between the study groups. Sensitivity and specificity calculations were then performed with a view to predicting conversion to CDMS. The patient subgroups defined by progression to CDMS differed significantly in values of fractional anisotropy (FA) kurtosis measured within white matter (WM) and normal-appearing WM (NAWM). The same parameters also differed significantly when patients with progression to CDMS were compared to healthy controls. Receiver operating characteristic (ROC) analysis revealed sensitivity and specificity of FA kurtosis of WM and NAWM of 93% and 72%, respectively, in terms of predicting CIS to CDMS progression. This study presents evidence that histogram analysis of diffusion parameters of the cervical spinal cord in patients with CIS may be helpful in predicting conversion to CDMS.

7 T imaging reveals a gradient in spinal cord lesion distribution in multiple sclerosis.

We used 7 T MRI to: (i) characterize the grey and white matter pathology in the cervical spinal cord of patients with early relapsing-remitting and secondary progressive multiple sclerosis; (ii) assess the spinal cord lesion spatial distribution and the hypothesis of an outside-in pathological process possibly driven by CSF-mediated immune cytotoxic factors; and (iii) evaluate the association of spinal cord pathology with brain burden and its contribution to neurological disability. We prospectively recruited 20 relapsing-remitting, 15 secondary progressive multiple sclerosis participants and 11 age-matched healthy control subjects to undergo 7 T imaging of the cervical spinal cord and brain as well as conventional 3 T brain acquisition. Cervical spinal cord imaging at 7 T was used to segment grey and white matter, including lesions therein. Brain imaging at 7 T was used to segment cortical and white matter lesions and 3 T imaging for cortical thickness estimation. Cervical spinal cord lesions were mapped voxel-wise as a function of distance from the inner central canal CSF pool to the outer subpial surface. Similarly, brain white matter lesions were mapped voxel-wise as a function of distance from the ventricular system. Subjects with relapsing-remitting multiple sclerosis showed a greater predominance of spinal cord lesions nearer the outer subpial surface compared to secondary progressive cases. Inversely, secondary progressive participants presented with more centrally located lesions. Within the brain, there was a strong gradient of lesion formation nearest the ventricular system that was most evident in participants with secondary progressive multiple sclerosis. Lesion fractions within the spinal cord grey and white matter were related to the lesion fraction in cerebral white matter. Cortical thinning was the primary determinant of the Expanded Disability Status Scale, white matter lesion fractions in the spinal cord and brain of the 9-Hole Peg Test and cortical thickness and spinal cord grey matter cross-sectional area of the Timed 25-Foot Walk. Spinal cord lesions were localized nearest the subpial surfaces for those with relapsing-remitting and the central canal CSF surface in progressive disease, possibly implying CSF-mediated pathogenic mechanisms in lesion development that may differ between multiple sclerosis subtypes. These findings show that spinal cord lesions involve both grey and white matter from the early multiple sclerosis stages and occur mostly independent from brain pathology. Despite the prevalence of cervical spinal cord lesions and atrophy, brain pathology seems more strongly related to physical disability as measured by the Expanded Disability Status Scale.

Multiple sclerosis lesions in motor tracts from brain to cervical cord: spatial distribution and correlation with disability.

Despite important efforts to solve the clinico-radiological paradox, correlation between lesion load and physical disability in patients with multiple sclerosis remains modest. One hypothesis could be that lesion location in corticospinal tracts plays a key role in explaining motor impairment. In this study, we describe the distribution of lesions along the corticospinal tracts from the cortex to the cervical spinal cord in patients with various disease phenotypes and disability status. We also assess the link between lesion load and location within corticospinal tracts, and disability at baseline and 2-year follow-up. We retrospectively included 290 patients (22 clinically isolated syndrome, 198 relapsing remitting, 39 secondary progressive, 31 primary progressive multiple sclerosis) from eight sites. Lesions were segmented on both brain (T2-FLAIR or T2-weighted) and cervical (axial T2- or T2*-weighted) MRI scans. Data were processed using an automated and publicly available pipeline. Brain, brainstem and spinal cord portions of the corticospinal tracts were identified using probabilistic atlases to measure the lesion volume fraction. Lesion frequency maps were produced for each phenotype and disability scores assessed with Expanded Disability Status Scale score and pyramidal functional system score. Results show that lesions were not homogeneously distributed along the corticospinal tracts, with the highest lesion frequency in the corona radiata and between C2 and C4 vertebral levels. The lesion volume fraction in the corticospinal tracts was higher in secondary and primary progressive patients (mean = 3.6 ± 2.7% and 2.9 ± 2.4%), compared to relapsing-remitting patients (1.6 ± 2.1%, both P < 0.0001). Voxel-wise analyses confirmed that lesion frequency was higher in progressive compared to relapsing-remitting patients, with significant bilateral clusters in the spinal cord corticospinal tracts (P < 0.01). The baseline Expanded Disability Status Scale score was associated with lesion volume fraction within the brain (r = 0.31, P < 0.0001), brainstem (r = 0.45, P < 0.0001) and spinal cord (r = 0.57, P < 0.0001) corticospinal tracts. The spinal cord corticospinal tracts lesion volume fraction remained the strongest factor in the multiple linear regression model, independently from cord atrophy. Baseline spinal cord corticospinal tracts lesion volume fraction was also associated with disability progression at 2-year follow-up (P = 0.003). Our results suggest a cumulative effect of lesions within the corticospinal tracts along the brain, brainstem and spinal cord portions to explain physical disability in multiple sclerosis patients, with a predominant impact of intramedullary lesions.

Cross-sectional and longitudinal assessment of the upper cervical spinal cord in motor neuron disease.

BackgroundAmyotrophic lateral sclerosis (ALS) is a progressive neuromuscular disease characterized by both upper and lower motor neuron degeneration. While neuroimaging studies of the brain can detect upper motor neuron degeneration, these brain MRI scans also include the upper part of the cervical spinal cord, which offers the possibility to expand the focus also towards lower motor neuron degeneration. Here, we set out to investigate cross-sectional and longitudinal disease effects in the upper cervical spinal cord in patients with ALS, progressive muscular atrophy (PMA: primarily lower motor neuron involvement) and primary lateral sclerosis (PLS: primarily upper motor neuron involvement), and their relation to disease severity and grey and white matter brain measurements.MethodsWe enrolled 108 ALS patients without C9orf72 repeat expansion (ALS C9–), 26 ALS patients with C9orf72 repeat expansion (ALS C9+), 28 PLS patients, 56 PMA patients and 114 controls. During up to five visits, longitudinal T1-weighted brain MRI data were acquired and used to segment the upper cervical spinal cord (UCSC, up to C3) and individual cervical segments (C1 to C4) to calculate cross-sectional areas (CSA). Using linear (mixed-effects) models, the CSA differences were assessed between groups and correlated with disease severity. Furthermore, a relationship between CSA and brain measurements was examined in terms of cortical thickness of the precentral gyrus and white matter integrity of the corticospinal tract.ResultsCompared to controls, CSAs at baseline showed significantly thinner UCSC in all groups in the MND spectrum. Over time, ALS C9– patients demonstrated significant thinning of the UCSC and, more specifically, of segment C3 compared to controls. Progressive thinning over time was also observed in C1 of PMA patients, while ALS C9+ and PLS patients did not show any longitudinal changes. Longitudinal spinal cord measurements showed a significant relationship with disease severity and we found a significant correlation between spinal cord and motor cortex thickness or corticospinal tract integrity for PLS and PMA, but not for ALS patients.DiscussionOur findings demonstrate atrophy of the upper cervical spinal cord in the motor neuron disease spectrum, which was progressive over time for all but PLS patients. Cervical spinal cord imaging in ALS seems to capture different disease effects than brain neuroimaging. Atrophy of the cervical spinal cord is therefore a promising additional biomarker for both diagnosis and disease progression and could help in the monitoring of treatment effects in future clinical trials.

Correlations between cervical spinal cord magnetic resonance diffusion tensor and diffusion kurtosis imaging metrics and motor performance in patients with chronic ischemic brain lesions of the corticospinal tract.

To investigate modifications of Magnetic Resonance Diffusion Tensor Imaging (DTI) and Diffusion Kurtosis Imaging (DKI) metrics in lateral white matter (WM) bundles of the cervical spinal cord in patients with previous stroke in the vascular territory of the middle cerebral artery (MCA). Twenty consecutive patients with a previous ischemic stroke of the MCA territory and a varying degree of upper motor impairment were enrolled. DKI was centered at the C3C4 and C5C6 intervertebral level. The fractional anisotropy (FA) values in C3C4 and C5C6 were found to be significantly lower in the lateral WM bundles contralateral to the ischemic lesion and thus, in the WM bundle including the affected corticospinal tract (CST) (p = 0.005 and p = 0.008, respectively), as well as mean kurtosis (MK) and axonal water fraction (AWF) values (p = 0.004 and p = 0.04. respectively). FA values correlated significantly with the Global Motor Index (GMI) both for C3C4 (ρ = 0.61, p = 0.004) and C5C6 (ρ = 0.69, p = 0.002). At C3C4, AWF correlated significantly with GMI (ρ = 0.54, p = 0.03). No correlations were found between lateral WM bundle volumes and GMI. A reduction of anisotropy and microstructural complexity in the affected lateral WM bundle of the cervical spinal cord was observed in patients with previous ischemic stroke involving the CST. The correlations between these metrics and motor performance were statistically significant.

Does MR spectroscopy of normal-appearing cervical spinal cord in patients with multiple sclerosis have diagnostic value in assessing disease progression? A prospective comparative analysis

To clarify the role of magnetic resonance spectroscopy (MRS) in examining the normal-appearing cervical spinal cord of patients with multiple sclerosis (MS) to detect metabolite abnormalities in this disease and to assess its progression. Thirty-six patients with MS and 30 healthy controls were enrolled. Each patient was submitted to MRS performed using a 1.5 T magnetic resonance imaging (MRI) scanner. The spectra of total N-acetyl-aspartate (tNAA), choline (Cho), creatine (Cr), and myoinositol (M-Ins), as well as the metabolite ratios of tNAA/Cr, tNAA/Cho, Cho/Cr, and M-Ins/Cr of the two groups were measured and compared. The correlations between the metabolite concentrations, disease duration, and clinical disability (expanded disability status scale, EDSS) were further explored. Significantly lower tNAA and higher M-Ins were observed in MS patients than in health controls. The tNAA/Cr and tNAA/Cho ratios were significantly lower in MS patients than in healthy controls. In MS patients, the EDSS was correlated with the tNAA/Cr ratio. The spinal cord cross-sectional area was significantly smaller in MS patients than in healthy controls. Reduced tNAA and increased M-Ins are important, sensitive indices for differentiating between MS patients and healthy controls. In MS patients, before lesions appear, MRS of the spinal cord may provide crucial information for assessing disease progression.

Brain imaging and genetic risk in the pediatric population, part 1: inherited metabolic diseases.

In this article, the genotype-MR phenotype correlation of the most common or clinically important inherited metabolic diseases (IMD) in the pediatric population is reviewed. A nonsystematic search of the PubMed/Medline database of relevant studies about "genotype-phenotype correlation" in IMD was performed. Some MR phenotypes related to specific gene mutations were found, such as bilateral hypertrophy of inferior olives in patients harboring POLG and SURF1 mutations, and central lesions in the cervical spinal cord in patients with nonketotic hyperglycinemia harboring GLRX5 gene mutation.

Preliminary Study on Cervical Spinal Cord in Patients with Amyotrophic Lateral Sclerosis Using MR Diffusion Tensor Imaging

To investigate the conventional magnetic resonance (MR) findings of cervical spinal cord, to explore the possible changes on diffusion tensor imaging (DTI) in patients with amyotrophic lateral sclerosis (ALS), and to assess the correlations between the changes on DTI and clinical parameters in patients with ALS. Conventional MR imaging (MRI) and DTI in 24 patients with ALS and 16 age-matched control subjects were obtained. On axial planes, regions of interest (ROIs) were marked in bilateral spinothalamic tracts (STs), posterior funiculus, and bilateral lateral corticospinal tracts (LCTs), respectively, at the levels of cervical 2-4 vertebral bodies. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of these ROIs were estimated. Independent sample t test and Pearson correlation analysis were used. In patients with ALS, no abnormal findings were noted in the cervical spinal cord on conventional MRI. FA values of bilateral LCTs decreased significantly compared to those of the control group (P < .05), and ADC values of bilateral LCTs were significantly greater than those of the control group (P < .05). FA and ADC values of bilateral LCTs showed no significant difference between patients with definite and probable ALS (P > .05). No significant correlation existed between abnormal DTI parameters (FA and ADC values of bilateral LCTs) and clinical parameters (P > .05). Subtle abnormalities in bilateral LCTs in the "normal-appearing" cervical spinal cord can be detected using quantitative DTI technique in patients with ALS.

Diffusion tensor imaging of the cervical spinal cord of patients with Neuromyelitis Optica

BackgroundPrevious studies have demonstrated a correlation between Expanded Disability Status Scale (EDSS) and Diffusion Tensor Imaging (DTI) metrics, but the conclusions were based on evaluations of the entire cervical spinal cord. ObjectivesThe purpose of this study was to quantify the FA and MD values in the spinal cord of NMO patients, separating the lesion sites from the preserved sites, which has not been previously preformed. In addition, we attempted to identify a correlation with EDSS. MethodsDTI was performed in 11 NMO patients and 11 healthy individuals using a 1.5-T MRI scanner. We measured the FA and MD at ROIs positioned along the cervical spinal cord. The mean values of FA and MD at lesion, preserved and spinal cord sites were compared with those of a control group. We tested the correlations between the mean FA and MD with EDSS. ResultsFA in NMO patients was significantly reduced in lesion sites (0.44 vs. 0.55, p=0.0046), preserved sites (0.46 vs. 0.55, p=0.0015), and all sites (0.45 vs 0.55, p=0.0013) while MD increased only in lesion sites (1.03×10−3mm2/s vs. 0.90×10−3mm2/s, p=0.009). The FA demonstrated the best correlation with EDSS (r=−0.7603, p=0.0086), particularly at lesion sites. ConclusionsThe results reinforce the importance of the FA index and confirm the hypothesis that NMO is a diffuse disease.

NEUROPHYSIOLOGICAL ASSESSMENT OF SPINAL FUNCTION IN SURGICAL TREATMENT OF PATIENTS WITH CERVICAL SPONDYLOGENIC MYELOPATHY

SummaryThe aim of the study is to improve diagnosis of spinal disorders in patients with cervical spondylogenic myelopathy (CSM) using complex neurophysiological (NPh) methods of diagnostics, development of Nph criteria...

Hypermetabolism in 18F-FDG PET Predicts Favorable Outcome Following Decompressive Surgery in Patients with Degenerative Cervical Myelopathy

The aim of this study was to prospectively assess the regional changes of glucose metabolism of the cervical spinal cord in patients with degenerative cervical spine stenosis and symptomatic cervical myelopathy after decompressive surgery using (18)F-FDG PET. Twenty patients with symptomatic degenerative monosegmental cervical stenosis with neuroradiologic signs of spinal cord compression underwent decompressive surgery. The clinical course using a functional status score (Japanese Orthopedic Association [JOA] score), (18)F-FDG uptake, and MR imaging were assessed before and at follow-up 12 mo after surgery. Pre- and postoperative changes of (18)F-FDG PET were correlated to the patients' clinical outcome. Ten patients demonstrated preoperatively a focally increased (18)F-FDG uptake at the level of the stenosis. At follow-up, the uptake declined significantly (P = 0.008), and a significant improvement of JOA scores (P < 0.001) could be observed. The remaining 10 patients were characterized preoperatively by an inconspicuous glucose uptake at the level of cord compression in combination with a poststenotic decrease of (18)F-FDG uptake. At follow-up, both JOA scores and (18)F-FDG uptake changed insignificantly. Focal glucose hypermetabolism at the level of cervical spinal cord compression may predict an improved outcome after surgical decompression. Thus, this finding on (18)F-FDG PET suggests a functional damage in a reversible phase of cervical myelopathy.

A Better Characterization of Spinal Cord Damage in Multiple Sclerosis: A Diffusional Kurtosis Imaging Study

The spinal cord is a site of predilection for MS lesions. While diffusion tensor imaging is useful for the study of anisotropic systems such as WM tracts, it is of more limited utility in tissues with more isotropic microstructures (on the length scales studied with diffusion MR imaging) such as gray matter. In contrast, diffusional kurtosis imaging, which measures both Gaussian and non-Gaussian properties of water diffusion, provides more biomarkers of both anisotropic and isotropic structural changes. The aim of this study was to investigate the cervical spinal cord of patients with MS and to characterize lesional and normal-appearing gray matter and WM damage by using diffusional kurtosis imaging. Nineteen patients (13 women, mean age = 41.1 ± 10.7 years) and 16 controls (7 women, mean age = 35.6 ± 11.2-years) underwent MR imaging of the cervical spinal cord on a 3T scanner (T2 TSE, T1 magnetization-prepared rapid acquisition of gradient echo, diffusional kurtosis imaging, T2 fast low-angle shot). Fractional anisotropy, mean diffusivity, and mean kurtosis were measured on the whole cord and in normal-appearing gray matter and WM. Spinal cord T2-hyperintense lesions were identified in 18 patients. Whole spinal cord fractional anisotropy and mean kurtosis (P = .0009, P = .003), WM fractional anisotropy (P = .01), and gray matter mean kurtosis (P = .006) were significantly decreased, and whole spinal cord mean diffusivity (P = .009) was increased in patients compared with controls. Mean spinal cord area was significantly lower in patients (P = .04). Diffusional kurtosis imaging of the spinal cord can provide a more comprehensive characterization of lesions and normal-appearing WM and gray matter damage in patients with MS. Diffusional kurtosis imaging can provide additional and complementary information to DTI on spinal cord pathology.

Pulse-Triggered DTI Sequence with Reduced FOV and Coronal Acquisition at 3T for the Assessment of the Cervical Spinal Cord in Patients with Myelitis

DTI is a promising technique for imaging of the spinal cord, but the technique has susceptibility-induced artifacts. We evaluated a pulse-triggered DTI sequence with an rFOV technique and coronal acquisition for the assessment of the cervical spinal cord in patients with myelitis at 3T. A rFOV acquisition was established by a noncoplanar application of the excitation and the refocusing pulse in conjunction with outer volume suppression. The DTI sequence was performed in the coronal plane in 12 healthy volunteers and 40 consecutive patients with myelitis. Probabilistic tractography of the posterior and lateral funiculi was performed from the C1 to C7 levels. FA, MD, aD, rD, and ratios of aD and rD were measured. In healthy volunteers, mean DTI indices within the whole-fiber pathways were the following: FA = 0.61, MD = 1.17 × 10(-3) mm(2)/s, aD = 1.96 × 10(-3) mm(2)/s, rD = 0.77 × 10(-3) mm(2)/s, and ratios of aD and rD = 2.5. Comparison of healthy controls and patients with myelitis identified statistically significant differences for all DTI parameters. Different patterns of myelitis, including spinal cord atrophy and active inflammatory lesions, were recognized. There was a significant correlation between clinical severity and DTI parameters. The present work introduces a new approach for DTI of the cervical spinal cord at 3T, enabling a quantitative follow-up of patients with myelitis.

Fiber density index in the evaluation of the spinal cord in patients with multiple sclerosis

The aims of this study were to determine fractional anisotropy (FA) and the fibre density index (FDi) in the cervical spinal cord of patients with multiple sclerosis (MS) by using diffusion-tensor magnetic resonance imaging (DT-MRI) to identify possible differences between MS patients and controls. We studied 27 patients with MS - nine with primary progressive (PPMS), nine with secondary progressive (SPMS) and nine with relapsing-remitting (RRMS) disease - and 18 healthy individuals as controls. Conventional and DTI sequences with diffusion gradients applied in 32 directions were obtained. The results were compared between healthy controls and patients, between healthy controls and individual forms of MS and between the three forms of MS. Statistical analysis was performed by analysis of variance (ANOVA) and Student's t test. The FDi in the three subgroups of patients and in controls showed a statistically significant difference. Using the t test, we found results from both PPMS and SPMS groups were different from controls. The correlation between FA and FDi was significant both in healthy controls and in MS patients evaluated as a single group. CONSLUCIONS: Despite the small group of patients, these findings suggest that FDi associated with FA is a sensitive parameter for assessing spinal cord damage in patients with MS.

Diffusion tensor imaging and fibre tracking in cervical spondylotic myelopathy

To (1) obtain microstructural parameters (Fractional Anisotropy: FA, Mean Diffusivity: MD) of the cervical spinal cord in patients suffering from cervical spondylotic myelopathy (CSM) using tractography, (2) to compare DTI parameters with the clinical assessment of these patients (3) and with information issued from conventional sequences. DTI was performed on 20 symptomatic patients with cervical spondylotic myelopathy, matched with 15 volunteers. FA and MD were calculated from tractography images at the C2-C3 level and compressed level in patients and at the C2-C3 and C4-C7 in controls. Patients were clinically evaluated using a self-administered questionnaire. The FA values of patients were significantly lower at the compressed level than the FA of volunteers at the C4-C7 level. A significant positive correlation between FA at the compressed level and clinical assessment was demonstrated. Increased signal intensity on T2-weighted images did not correlate either with FA or MD values, or with any of the clinical scores. FA values were significantly correlated with some of the patients' clinical scores. High signal intensity of the spinal cord on T2 was not correlated either with the DTI parameters or with the clinical assessment, suggesting that FA is more sensitive than T2 imaging.

Regional impairment of 18F-FDG uptake in the cervical spinal cord in patients with monosegmental chronic cervical myelopathy

The aim of this preliminary report was to assess glucose metabolism in the cervical spine of patients with chronic compressive myelopathy by using FDG PET. Ten patients with monosegmental chronic degenerative stenosis and local cord compression of the upper/middle cervical spine with signs of myelopathy on MRI and 10 control patients without known cervical abnormalities were investigated by FDG PET. Maximum standardised uptake values (SUV(max)) were measured at all levels of the cervical spine (C1-C7). While the controls showed the typical pattern of homogeneous linear FDG uptake along the entire cervical cord, the patients with chronic compressive myelopathy had a normal glucose utilisation only above the level of stenosis and a significant decrease in FDG uptake below their individual level of cord compression. This may be caused by atrophy of anterior grey horn cells and the loss of glucose-consuming neurons below the level of cord compression. FDG PET of the spine of patients with chronic compressive myelopathy may be helpful to determine the stage and severity of cervical myelopathy.