Biomedical subjects

M A Rocca

Publications and source records attributed to M A Rocca.

At least 73 records · Page 4Linked to original sources

PubMed1998

A longitudinal brain MRI study comparing the sensitivities of the conventional and a newer approach for detecting active lesions in multiple sclerosis.

Monthly dual-echo spin-echo (SE) and enhanced magnetic resonance imaging (MRI) after the injection of a standard dose (SD) of gadolinium (Gd) is the conventional approach to monitor short-term disease activity in multiple sclerosis (MS). In this study, the sensitivity of this approach in detecting active lesions in MS was compared with that of monthly fast fluid attenuated inversion recovery (FLAIR) scans associated with enhanced MRI after the injection of a triple dose (TD) of Gd. Thirteen patients with relapsing-remitting MS entered the study. Monthly MRI scans were obtained on four occasions in two separate sessions (interval between 12 and 24 h). In one session, dual-echo conventional SE and SD Tl-weighted scans were obtained; in the other, fast-FLAIR and TD Tl-weighted scans. The order of the two sessions was randomized. Three observers counted the number of active lesions detected by each of the two approaches. One hundred and four active lesions were detected by the conventional approach and 199 by the newer approach (average increase per patient = 75%, range = 0-325%). The mean number of active lesions per month per patient was 2.0 for the conventional approach and 3.8 for the new approach (P = 0.004). Scans with active lesions were 34/52 (65%) with the conventional approach and 37/52 (71%) with the new approach. Our data indicate that the combined use of monthly fast-FLAIR and TD enhanced Tl-weighted scans increases the number of active lesions detected on serial MRI scans from patients with MS.

Adult↗

PubMed1998

Quantitative volumetric analysis of brain magnetic resonance imaging from patients with multiple sclerosis.

We compared the volumes of the brain as a whole and of different cerebral structures from patients with multiple sclerosis (MS) and normal subjects. In the patients, we also correlated brain volumes with T2 and T1 lesion loads and disability. A magnetization-prepared rapid acquisition gradient echo (MP RAGE) sequence with subsequent reconstruction of axial 1-mm thick slices and a dual-echo sequence were obtained in 15 patients with relapsing-remitting or secondary progressive MS and 15 sex-, age-, height- and weight-matched normal subjects. The brains and the different cerebral structures studied (cerebral hemispheres, cerebellum and brainstem) were segmented manually by a single observer on the 1-mm MP RAGE scans. The hyperintense lesion volumes seen on dual-echo scans and the hypointense lesion volumes seen on the 1-mm MP RAGE scans were measured using a semi-automated segmentation technique based on local thresholding. Compared to the normal volunteers, patients had significantly lower cerebral (P = 0.008), hemispheric (P = 0.01) and brainstem (P = 0.03) volumes. Cerebral atrophy was detected in seven (47%) MS patients. Patients with brainstem signs had significantly lower mean brainstem volume than the others (P = 0.04). No significant correlations were found between the cerebral volumes and the EDSS scores, the hyperintense lesion volumes and the hypointense lesion volumes. We conclude that cerebral atrophy is a relatively frequent finding in MS, but its relationship with physical disability is modest.

Adult↗

PubMed1998

A one year study of new lesions in multiple sclerosis using monthly gadolinium enhanced MRI: correlations with changes of T2 and magnetization transfer lesion loads.

In this study, 14 patients with either relapsing-remitting or secondary progressive multiple sclerosis (MS) were scanned monthly using gadolinium enhanced magnetic resonance imaging (MRI). At the start of the study and at 1 year follow up, T2-weighted and magnetization transfer (MT) scans were also performed. The correlation between the frequency and extent of enhancement and changes of lesion load over a 1 year period on T2-weighted and MT images were assessed. For all patients, and for the relapsing-remitting patients only, the number and volume of enhancing lesions per month showed no significant correlation with the change between baseline and 1 year follow up of lesion volumes on T2 and MT images. However, strong correlations were found between the number and volume of gadolinium enhancing lesions with changes of T2 (r = 0.93, P = 0.02) and MT (r = 0.82, P = 0.04) lesion loads in patients with secondary progressive MS. Strong correlations were also found between the lesion loads on T2-weighted scans and on MT images both at baseline and at 1 year follow up (r = 0.83, P = 0.003). In addition, the changes in lesion load over 1 year, detected using the two techniques, were moderately correlated (r = 0.51, P = 0.05). This study provides further evidence that the pathological processes in MS are at different stages in relapsing-remitting and secondary progressive MS. It also suggests that the effectiveness of recovery mechanisms within lesions might be one of the major factors responsible for such a difference.

Adult↗

PubMed1998

Correlations between monthly enhanced MRI lesion rate and changes in T2 lesion volume in multiple sclerosis.

Magnetic resonance imaging (MRI) provides a powerful tool for assessing disease activity in multiple sclerosis (MS), and its role as a surrogate marker for monitoring treatment efficacy is now becoming established. The most commonly used MRI parameters in treatment trials are (1) monthly gadolinium-enhanced MRI, with the number of active lesions serving as the outcome measure, and (2) annual lesion load quantification, in which change in MS lesion volume provides the MRI endpoint. We evaluated clinical/MRI correlations and the relationship between these two markers of disease activity in 73 patients with clinically definite MS. Quantification of T2 lesion load was performed at study entry and exit, with a median study duration of 11 months (range, 9 to 14 months). Monthly postgadolinium T1-weighted images were acquired between these time points. Lesion load at study entry was significantly correlated with the baseline Expanded Disability Status Scale (EDSS) score, but no significant longitudinal correlation was demonstrated. The number of enhancing lesions on the entry scan was predictive of subsequent relapse rate over the study duration and also correlated with the subsequent enhancing lesion activity over the study period. A significant correlation was found between change in lesion load and disease activity on the monthly scans. Our results suggest that annual lesion load quantification provides an efficient measure of ongoing disease activity, and this supports its application as a surrogate marker of disease evolution in phase III treatment trials.

Adolescent↗

PubMed1998

Magnetization transfer changes in the normal appearing white matter precede the appearance of enhancing lesions in patients with multiple sclerosis.

Serial monthly magnetization transfer (MT) imaging was performed to evaluate whether a change of the normal appearing white matter (NAWM), which precedes the appearance of enhancing lesions, is seen in patients with multiple sclerosis (MS). Every 4 weeks for 3 months, 10 patients with relapsing-remitting MS were scanned with a T1-weighted sequence, 20 minutes after injection with 0.3 mmol/kg gadolinium-DTPA (Gd-DTPA). During each of the monthly sessions, MT and dual echo scans were also performed before Gd-DTPA injection. On coregistered images, the MT ratio (MTR) was measured in NAWM subsequently involved by enhancing lesions, in NAWM areas on the same slices but outside any present or future MR abnormality, and in enhancing lesions at the time of their appearance. Forty-eight new enhancing lesions with no corresponding abnormalities on previous scans were identified. Their average MTR was 33.1% (+/-8.4%). Three, 2, and 1 month before enhancement appearance, the mean MTR in NAWM, measured from areas corresponding to future enhancing lesions, was significantly lower than the mean MTR in NAWM outside enhancing areas; the MTR decreased steadily as the time when the enhanced lesion approached. These results suggest that changes in the NAWM of patients with MS occur before lesions become evident on conventional MRI scans.

Adult↗

PubMed1998

A comparison between the sensitivities of 3-mm and 5-mm thick serial brain MRI for detecting lesion volume changes in patients with multiple sclerosis.

In this longitudinal study the authors evaluated the sensitivity of 3-mm and 5-mm magnetic resonance imaging (MRI) of the brain in the detection of lesion load changes over time in multiple sclerosis (MS). The authors also correlated the changes detected with these two techniques with the changes in disability. Eighteen patients with MS underwent two MRI examinations of the brain--one at entrance into the study and one follow-up examination. At both sessions, images with 24 contiguous slices 5 mm thick and another with 40 contiguous axial slices 3 mm thick were consecutively acquired. On the same occasions, the patients' Expanded Disability Status Scale (EDSS) scores were rated. MR images with slices 3 mm thick showed higher lesion loads than those with slices 5 mm thick at both entrance and follow-up examinations (median, 13.4 vs 12.8 ml and 17.5 vs 17.0 ml, respectively; p < 0.0001). The correlation between MRI and EDSS changes was significant for both MRI acquisition schemes (3 mm, r = 0.64; 5 mm, r = 0.59). The data suggest that acquisition of thinner slices does not significantly increase the sensitivity of MRI of the brain in the detection of lesion load changes in MS.

Adult↗

PubMed1998

Detecting new lesion formation in multiple sclerosis: the relative contributions of monthly dual-echo and T1-weighted scans after triple-dose gadolinium.

In this study, we evaluated the frequency of formation of new lesions on brain magnetic resonance imaging (MRI) from patients with relapsing-remitting multiple sclerosis (MS) and defined the relative contributions of unenhanced and enhanced MRI. Every 4 weeks for 3 months, dual-echo and postcontrast T1-weighted (5 min after the injection of 0.3 mmol/kg gadolinium-DTPA) scans were obtained from 28 patients with relapsing-remitting MS. New lesions were defined as those present on dual-echo and/or postcontrast T1-weighted scans but with no corresponding MRI abnormalities on any of the preceding scans. A total of 111 newly formed lesions were detected during the follow-up on dual-echo and postcontrast T1-weighted scans (i.e., an average of 1.3 lesions per patient per month). Ninety-eight (88%) of such lesions were seen on both dual-echo and postcontrast T1-weighted scans, whilst 13 (12%) were seen only with one of the two techniques: 9 only on dual-echo and 4 only on postcontrast scans. Five of the 98 new lesions seen by both techniques were seen by postcontrast scans 1 month before their appearance on dual-echo scans. Our study suggests that both dual-echo and postcontrast T1-weighted scans are useful to detect newly formed lesions in patients with MS. This is of importance when using MRI to monitor the efficacy of treatments which may halt MS lesion formation.

Adult↗

PubMed1998

The effect of cross-talk on MRI lesion numbers and volumes in multiple sclerosis using conventional and turbo spin-echo.

We measured and compared lesion numbers and volumes present on brain magnetic resonance imaging (MRI) scans of patients with multiple sclerosis (MS) acquired with contiguous (scheme A) and interleaved (scheme B) slice acquisition, to evaluate whether there was a gain in sensitivity using the second pattern of acquisition and whether this counterbalanced the doubled acquisition time. Conventional spin-echo (CSE) sequences were performed for eight patients and turbo spin-echo (TSE) sequences for ten. Acquisition scheme B detected 3.8% more lesions than acquisition scheme A (the increase was 3.1% for CSE and 4.5% for TSE). These differences were not statistically significant. No significant difference in lesion numbers was found when different lesion locations were also considered. Lesions volumes were significantly higher when scheme B was used (P = 0.024). This was due to higher lesion volumes on TSE images (P = 0.006), especially on even-numbered slices (P = 0.008). Inter-slice cross-talk has a negligible effect on lesion numbers and volume estimates in MS for CSE sequence, whilst it cannot be neglected when TSE sequences are used to measure MS lesion volume.

Adult↗

PubMed1998

Magnetization transfer ratios in multiple sclerosis lesions enhancing after different doses of gadolinium.

We performed serial monthly magnetization transfer (MT) imaging to evaluate whether MS lesions that enhance only after the injection of a triple dose (TD) of gadolinium-DTPA (Gd) have different pathologic characteristics and evolution than those that enhance after the injection of a standard dose (SD). Every 4 weeks for 3 months and in two separate sessions, we obtained T1-weighted scans from 10 patients with relapsing-remitting MS, 5 minutes after SD (0.1 mmol/kg) or TD (0.3 mmol/kg) Gd injection. During each of the first monthly sessions, we obtained MT images and dual-echo scans before Gd injection. We measured the MT ratio (MTR) of newly enhancing lesions on co-registered quantitative MTR images. During the 3-month follow-up, 81 newly enhancing lesions were seen on SD scans. An additional 46 lesions enhanced only on TD scans. The mean (+/- standard deviation) MTR values were 31.4% +/- 8.4% for lesions enhancing after SD and 38.2% +/- 6.0% for lesions enhancing only after TD injection (p < 0.0001). The mean MTR values of lesions seen with both SD (p < 0.00001) and TD (p = 0.002) increased significantly during the follow-up. At each time point during the follow-up, the MTR values of TD lesions were significantly higher than the SD lesions. These results indicate that the enhancing lesion population in MS is heterogeneous and that the tissue damage occurring within lesions enhancing only after TD injection is less severe than in lesions enhancing after the injection of an SD.

Adult↗

PubMed1998

Relation between MR abnormalities and patterns of cognitive impairment in multiple sclerosis.

OBJECTIVE: This study correlated the extent of abnormalities detected by different magnetic resonance imaging (MRI) techniques [proton density (PD)-weighted, T1-weighted, and magnetization transfer imaging (MTI)] with the overall cognitive, frontal lobe, and memory impairments in patients with MS. PATIENTS: There were 30 clinically definite MS patients, with different disease courses. EXCLUSION CRITERIA: psychoactive/steroid treatments, mood disorders, acute relapse phase. MAIN OUTCOME MEASURES: Neuropsychological test results. Total (TLL) and frontal (FLL) lesion loads assessed from PD-weighted, T1-weighted (22 patients), and MTI (22 patients) MRI scans. Average lesion MT ratios (MTR) and analysis of the MTR histograms from brain tissue axial slabs on MTI scans. RESULTS: Patients with frontal lobe deficits (n=15) or memory impairment (n-17) had a higher TLL on PD scans (p=0.04 and p=0.01, respectively). Patients with frontal lobe deficits had higher FLL on PD scans (p=0.01) and TLL on MTI (p=0.03) scans. No significant relationships between the extent of T1-weighted lesion loads and the presence of any neuropsychological impairment. Mean MTR of both MS lesions and whole brain tissue was lower in patients with frontal lobe impairment (p=0.04). MRI lesion loads correlated significantly with some neuropsychological test scores. CONCLUSIONS: Lesion loads on PD-weighted MRI and MTI-derived measures are associated with cognitive decline in MS patients. Overall macroscopic and microscopic brain damage is more important than the corresponding regional brain disease in determining deficits of selective cognitive domains.

Adult↗

PubMed1998

Increased spatial resolution using a three-dimensional T1-weighted gradient-echo MR sequence results in greater hypointense lesion volumes in multiple sclerosis.

PURPOSE: Our goal was to evaluate whether improved spatial resolution of MR images results in the detection of higher volumes of hypointense lesions in patients with multiple sclerosis (MS). METHODS: A magnetization-prepared rapid acquisition gradient-echo (MP-RAGE) sequence with subsequent reconstruction of axial sections with 5-, 3-, and 1-mm thickness and a dual-echo sequence were obtained in 16 patients with relapsing-remitting or secondary-progressive MS. The volumes of MR imaging abnormalities present on each of these studies were measured using a semiautomated segmentation technique based on local thresholding. The hypointense lesion volumes seen on the three reconstructed MP-RAGE sets of images were compared using the Friedman test and correlated with the hyperintense lesion volume on proton density-weighted images and with scores on the Expanded Disability Status Scale using Spearman's rank correlation coefficient. RESULTS: The median volume of hypointense lesions increased from 1.2 mL (range, 0 to 14.9 mL) on the 5-mm-thick MP-RAGE images to 1.7 mL (range, 0 to 15.8 mL) on the 3-mm-thick images, and to 1.9 mL (range, 0 to 16.2 mL) on the 1-mm-thick images. The hypointense lesion volumes measured on the three MP-RAGE images correlated significantly with the degree of disability, whereas this correlation was not significant with the T2-weighted lesion load. CONCLUSION: Our findings indicate that a significant increase in the volume of potentially disabling MS lesions is observed when obtaining MR images with thin sections.

Adult↗

PubMed1998

Intraobserver and interobserver variability in schemes for estimating volume of brain lesions on MR images in multiple sclerosis.

PURPOSE: Our goal was to evaluate the intraobserver and interobserver reproducibility of measurements of brain lesion load in multiple sclerosis (MS) by using two proposed acquisition schemes. METHODS: Three-millimeter-thick conventional spin-echo (CSE) and fast fluid-attenuated inversion-recovery (FLAIR) sequences were obtained and the lesions segmented using a semiautomated technique based on local thresholding to calculate intraobserver and interobserver reproducibility. These were compared with images obtained from two separate MR units in which 5-mm CSE sequences were obtained and segmented by using the local thresholding technique and also by manual outlining. RESULTS: The intraobserver coefficient of variation was 4.0% (95% confidence interval [CI], 3.0% to 4.5%) for the 5-mm CSE sequence measured with manual outlining, 3.1% (95% CI, 2.5% to 3.2%) and 5.1% (95% CI, 4.1% to 5.6%) for the two sets of 5-mm CSE sequences measured using the local thresholding technique, 5.7% (95% CI, 3.9% to 6.6%) for the 3-mm CSE sequence, and 2.6% (95% CI, 2.1% to 2.7%) for the fast FLAIR sequence. The interobserver coefficient of variation was 7.1% (95% CI, 4.9% to 8.7%) and 8.3% (95% CI, 6.4% to 9.6%) for the two sets of 5-mm CSE sequences, 7.3% (95% CI, 4.7% to 9.1%) for the 3-mm CSE sequence, and 2.9% (95% CI, 2.3% to 3.3%) for the fast FLAIR sequence. The intraobserver and interobserver reproducibility of measurements obtained with the fast FLAIR technique was significantly better than those obtained with the other techniques. CONCLUSIONS: Our data indicate that the intraobserver and interobserver variability in quantifying MS lesions can be reduced significantly with the use of fast FLAIR sequences, while no significant improvement is gained by reducing the section thickness from 5 mm to 3 mm.

Adult↗

PubMed1998

Intraobserver and interobserver variability in measuring changes in lesion volume on serial brain MR images in multiple sclerosis.

PURPOSE: We evaluated the intraobserver and interobserver variability in measuring long-term changes in the volume of brain lesions on 5- and 3-mm-thick MR sections in patients with multiple sclerosis. METHODS: Eighteen 18 patients were scanned on two separate occasions with a mean interval of 16.4 months between the two examinations. In each session, a scan with 24 contiguous 5-mm-thick axial sections and another with 40 contiguous 3-mm-thick axial sections was acquired consecutively without moving the patient. We assessed MR lesion load by using a semiautomated local thresholding technique. RESULTS: Lesion volume was significantly higher on images with 3-mm-thick sections than on those with 5-mm-thick sections both at baseline and at follow up. Significant increases in total lesion volume were observed during the follow-up period on images obtained with both 5- and 3-mm-thick sections. The intra- and interobserver variability in measurements of changes in lesion volume was significantly higher on images with 5-mm-thick sections than on those with 3-mm-thick sections. CONCLUSION: Our data indicate that the acquisition of thinner sections increases the reliability of the assessment of changes in brain lesion load on MR images in patients with multiple sclerosis.

Adult↗

PubMed1997

Sensitivity of delayed gadolinium-enhanced MRI in multiple sclerosis.

INTRODUCTION: We performed this study to define the sensitivity of delayed gadolinium-enhanced magnetic resonance imaging (MRI) in detecting active lesions in the brains of patients with multiple sclerosis (MS). MATERIAL AND METHODS: T1-weighted images were obtained in 27 patients with relapsing-remitting or secondary progressive MS before, 5-7 min and 20-30 min after the injection of 0.1 mmol/kg gadolinium-DTPA. RESULTS: One-hundred-and-three enhancing lesions were found on the early and 110 on the delayed scans (increase=6.4%). Six patients had 8 additional lesions in the delayed scans, while 1 patient had 1 more lesion on the early scan. Two of the 12 (17%) patients with no enhancing lesions on the early scans had 2 enhancing lesions on the delayed scans. The average increase of enhancing lesion detection with delayed scanning was 14.5% for those patients who already had enhancing lesions on the early post-contrast scans. A significant increase of the enhancing lesion volume was found with delayed scanning (P=0.004). CONCLUSION: These data indicate that it is possible to increase MRI sensitivity in detecting MS active lesions by delaying the scanning after gadolinium injection.

Adult↗

PubMed1997

The influence of slice orientation on brain MRI lesion load measurement in multiple sclerosis.

This study aimed at evaluating the influence of a different slice orientation on brain magnetic resonance imaging (MRI) lesion load in multiple sclerosis (MS). Fifteen MS patients were scanned obtaining both axial and sagittal conventional spin echo (24 slices; TR 2400, TE 30/80) brain MRI. The total lesion load (TLL) was assessed twice for each scan, using a semi-automated local thresholding technique and the same marked hardcopies. The mean TLL was 22734 mm3 for axial and 22003 mm3 for sagittal scans. The mean intra-observer coefficient of variation (COV) was 4.65% for the axial acquisitions and 4.52% for the sagittal acquisitions. This difference was not statistically significant (one-way ANOVA, P > 0.1). The lesion load was significantly higher from axial MRI as compared to the intra-observer variability (two-way ANOVA, P=0.01), but the fluctuations around this average difference between axial and sagittal scan TLL were significantly large (test for interaction, P < 0.001). Our data indicate that the use of sagittal conventional MRI scans does not seem to be worthwhile for the quantitative assessment of lesion load in MS patients.

Adult↗

PubMed1997

The effect of imprecise repositioning on lesion volume measurements in patients with multiple sclerosis.

In this study, we evaluated the effect of imprecision in patient repositioning encountered in real life on multiple sclerosis (MS) lesion volumes measured from MRIs. We also evaluated two putative methods for reducing the variability in these lesion volume measurements: first, a reduction of slice thickness (from the conventional 5 mm to 3 mm) and second, the application of a new repositioning technique based on the use of head immobilization shells. We evaluated the errors in lesion volume by scanning 10 patients a total of four times using the two slice thicknesses and two repositioning methods (conventional and using a head immobilization shell). The mean absolute percentage difference between two corresponding scans was 6.8% (range, 1.24 to 11%) using conventional slice thickness and repositioning, 4.1% (range, 0.7 to 5.56%) using conventional slice thickness and head immobilization shells, 2.6% (range, 0.8 to 6.66%) using the conventional repositioning technique and 3-mm slice thickness, and 1.4% (range, 0.2 to 6.14%) using slice thickness of 3 mm and head immobilization shells. These mean absolute differences were significantly different (p = 0.0008). Our results indicate that the effect of repositioning errors of the order of those that can be encountered in the daily life situation of clinical trials affects significantly lesion load measurements in MS and that the combined use of thinner slices and more accurate repositioning techniques can markedly improve the reproducibility of such measurements.

Adult↗

PubMed1997

Interscanner variation in brain MRI lesion load measurements in MS: implications for clinical trials.

We evaluated the effect of interscanner variation on brain MRI-measured lesion volumes and measurement reproducibility in MS. Twenty clinically definite MS patients were each scanned on two or three scanners (a total of 14 scanners were used). In addition, a formalin-fixed MS brain was studied on eight scanners from different manufacturers and with different field strengths. For the formalin-fixed MS brain, on each machine we obtained two scans with slice thicknesses of 5 and 3 mm. Only 5-mm-thick slices were obtained from patients. The lesion volume present on each scan was evaluated three times by a single observer in random order, using a local thresholding technique. In two groups of eight patients scanned on machines with different field strengths, the mean lesion volumes present on scans obtained at 1.5 T were significantly higher than those measured on scans obtained with machines operating at 0.5 and 1.0 T (p < 0.01). When a single observer repeatedly evaluated the same scan, a median introbserver agreement of 98.7% (95% CI, 97.9 to 99.1) was achieved. However, when the observer evaluated the scans from different MRI scanners, the agreement (an interscanner agreement) fell to 91.1% (CI, 90.2 to 94.1). When only scanners operating at 1.5 T were considered, the median interscanner agreement was 96.7% (CI, 95 to 97.5). Also, for the formalin-fixed MS brain, the intraobserver agreements obtained with both slice thicknesses were significantly higher than the corresponding interscanner agreements. The interscanner agreement, but not the intraobserver agreement, obtained with a slice thickness of 3 mm was higher than that obtained with a slice thickness of 5 mm. Our results indicate that lesion volume measurements in MS are influenced significantly by the use of different MR scanners and that a patient included in a serial study should be always scanned with the same MR machine using 3-mm thick slices.

Adult↗

PubMedDate not supplied

Magnetization-transfer histogram analysis of the cervical cord in patients with multiple sclerosis.

BACKGROUND AND PURPOSE: Previous studies have failed to show significant correlations between the number and extent of T2 spinal cord lesions and the clinical status of multiple sclerosis (MS) patients. We evaluated 1) whether it is feasible to create magnetization transfer-ratio (MTR) histograms of the cervical cord in patients with MS by using two different acquisition schemes, and 2) whether cervical cord MTR histogram metrics were different from those of healthy control subjects and between MS patients with and without locomotor disability. METHODS: We obtained two sets of gradient-echo sequences with and without a saturation pulse from 90 MS patients and 20 sex- and age-matched healthy control subjects. One set consisted of 20 axial, contiguous slices with a thickness equal to 5 mm. The other set consisted of 17 sagittal slices with a thickness equal to 3 mm and an interslice gap equal to 0.3 mm. After image coregistration and removal of tissues around the cervical cord, MTR histograms were created. The average MTR, the peak height, and the peak position of the histograms were measured. All of these measurements were from the whole of the cervical cord, thus including both MS lesions and normal-appearing tissue. RESULTS: When comparing the MTR histograms obtained using axial, contiguous, 5-mm-thick slices, MS patients had significantly lower average cervical cord MTR and peak height than did control subjects. When comparing the MTR histograms obtained using sagittal, 3-mm-thick slices, MS patients also had significantly lower average cervical cord MTR and peak location than did control subjects. Patients with locomotor disability had significantly lower average cord MTR and peak location than those without. CONCLUSION: This study shows that it is feasible to obtain MTR histograms of the cervical cord from MS patients by using different acquisition schemes. Our results also suggest that the assessment of MS cervical cord damage, achieved using MTR histograms, may lead to a better understanding of the clinical manifestations of the disease.

Adult↗