Teaching NeuroImages: Marked reduced apparent diffusion coefficient in acute multiple sclerosis lesion (original) (raw)
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The contribution of diffusion-weighted MR imaging in multiple sclerosis during acute attack
European Journal of Radiology, 2008
Purpose: The aims of the study are firstly, to determine the difference in diffusion-weighted imaging (DWI) in normal appearing white matter (NAWM) between patients with acute multiple sclerosis (MS) and controls; secondly, to determine whether there is a correlation between EDSS scores and DWI in acute plaques and also NAWM. Materials and method: Out of 50 patients with acute MS attack, 35 patients had active plaques with diffuse or ring enhancement on postcontrast images. Eighteen healthy volunteers constituted the control group. While 26 of 35 had relapsing-remitting, 9 had secondary progressive MS. Apparent diffusion coefficients (ADC) of the active plaques, NAWM at the level of centrum semiovale and occipital horn of lateral ventricle in the patients and NAWM in control group were measured. ADC values of active plaques were compared with WM of the patients and the control group. The relationship of ADC value of active plaques and WM in MS with expanded disability status scale (EDSS) was investigated by using Mann-Whitney U-test. Results: Of 63 plaques totally, 26 and 37 of the active plaques had diffuse and ring enhancement, respectively. There was no statistically significant difference between ADC value of active plaques and EDSS (p > 0.05). However, there was a statistically significant difference between ADC value of WM occipital horn and EDSS (p < 0.05). ADC value of active plaques were higher than WM in both groups (p < 0.001). The difference between ADC value of WM at the centrum semiovale (p < 0.05) and occipital horns (p < 0.001) in patients and controls was statistically significant. There was no statistically significant difference between EDSS scores, ADC value at centrum semiovale and WM around occipital horn and active plaques in subgroups (p > 0.05). Conclusion: Apparently normal tissue in MS patients may show early abnormalities when investigated carefully enough, and there is an even though moderate correlation between EDSS and ADC values and early alterations of ADC value are starting in the occipital white matter along the ventricles. This has to be verified in larger series.
Benha Medical Journal
Background: Magnetic resonance imaging (MRI) is a very vital tool to diagnose and monitor multiple sclerosis (MS). Standard MRI measures lack of pathological specificity and are weakly correlated with MS clinical manifestations. Advanced MRI techniques together with diffusion studies square measure up the understanding of the mechanisms underlying tissue injury, repair and functional adaptation in MS but, they need careful standardization. It doesn't only enhance the understanding of the pathophysiology and evolution of disease, but also to generate research hypotheses, monitor treatment, increase costeffectiveness and power of clinical trials. Aim of the Work: The aim of this study is to evaluate the role of DTI in assessment of MS versus the normally-appearing white matter (NAWM). Patients and Methods: The study included 50 patients, 42 females and 8 males having MS (between 20 and 40 years of age) referred from Neurologists to Radio-diagnosis Department at Benha University hospitals with 5 age-matched control subjects (during the period between Aug. 2018 and Jan. 2020). Each patient included in the study was subjected to full history taking, reviewing medical sheet and MR examination including: Conventional MR examination and Diffusion Tensor imaging. Technique was performed using a standard 1.5 Tesla unit. Results: The study showed that DTI can reveal changes in NAWM in MS cases before visible sizable plaques can be detected by conventional MRI.
The evaluation of MRI diffusion values of active demyelinating lesions in multiple sclerosis
Multiple Sclerosis and Related Disorders, 2016
Background: Gadolinium (Gd) enhancement of lesions is the main radiologic marker for detection of activity in Multiple Sclerosis (MS). This study compares Diffusion weighted imaging (DWI) characteristics and enhancement to determine whether DWI can be used as an alternative to Gd administration. Methods: A retrospective study of 72 patients who had MRI with Gd and DWI. Visual assessment and comparison of the Apparent Diffusion Coefficient (ADC) values on Gd+ lesions, all lesions showing restricted diffusion, 2 Gd− lesions and 1 area of normal-appearing white matter (NAWM) in each MRI were performed. Results: DWI values were measured on 275 T2 lesions, 68 Gd+ and 207 Gd− lesions, as well as 104 NAWM. 34 Gd+ lesions showed restricted diffusion. The median ADC-minimum of Gd+ lesions was significantly lower than NAWM and even lower than Gd− lesions. Most DWI restricted lesions were also Gd+(specificity≥94%), however many Gd+ lesions did not show visually detectable restriction in DWI (sensitivity≤34%). The median ADCminimum of symptomatic lesions was lower than asymptomatic lesions. Conclusion: While Gd+ lesions have lower ADC-minimum, visual DWI assessment cannot replace Gd administration for identifying active lesions. Gd+ lesions showing restricted diffusion are clinically important as they are more likely associated with neurological symptoms.
Diffusion tensor imaging of post mortem multiple sclerosis brain
NeuroImage, 2007
Magnetic resonance imaging (MRI) is being used to probe the central nervous system (CNS) of patients with multiple sclerosis (MS), a chronic demyelinating disease. Conventional T 2 -weighted MRI (cMRI) largely fails to predict the degree of patients' disability. This shortcoming may be due to poor specificity of cMRI for clinically relevant pathology. Diffusion tensor imaging (DTI) has shown promise to be more specific for MS pathology. In this study we investigated the association between histological indices of myelin content, axonal count and gliosis, and two measures of DTI (mean diffusivity [MD] and fractional anisotropy [FA]), in unfixed post mortem MS brain using a 1.5-T MR system. Both MD and FA were significantly lower in post mortem MS brain compared to published data acquired in vivo. However, the differences of MD and FA described in vivo between white matter lesions (WMLs) and normal-appearing white matter (NAWM) were retained in this study of post mortem brain: average MD in WMLs was 0.35 × 10 − 3 mm 2 /s (SD, 0.09) versus 0.22 (0.04) in NAWM; FA was 0.22 (0.06) in WMLs versus 0.38 (0.13) in NAWM. Correlations were detected between myelin content (Tr myelin ) and (i) FA (r = − 0.79, p < 0.001), (ii) MD (r = 0.68, p < 0.001), and (iii) axonal count (r = − 0.81, p < 0.001). Multiple regression suggested that these correlations largely explain the apparent association of axonal count with (i) FA (r = 0.70, p < 0.001) and (ii) MD (r = − 0.66, p < 0.001). In conclusion, this study suggests that FA and MD are affected by myelin content and -to a lesser degree -axonal count in post mortem MS brain.
Reduced Diffusion in a Subset of Acute MS Lesions: A Serial Multiparametric MRI Study
American Journal of Neuroradiology, 2012
BACKGROUND AND PURPOSE: MRI studies have focused on newly developing MS lesions to characterize the early pathology of the disease. DWI is highly sensitive to acute and chronic tissue changes in MS. We characterized the development of acute MS lesions by using DWI in a multiparametric MRI protocol. MATERIALS AND METHODS: Seventy-two consecutive patients presenting with a new symptom with definite MS or a CIS suggestive of central nervous system demyelination were screened with MRI. Patients who showed an acute MRI lesion with a reduction of ADC were studied with serial MRI for up to 4 months after presentation. RESULTS: Ten of 72 screened patients who showed a lesion with a reduced ADC were each examined 4-7 times, resulting in 52 examinations in total. We identified a characteristic sequence of signalintensity changes: 1) days 0-7: slight T2 hyperintensity and prominent ADC reduction (maximum, Ϫ66%), faint or no enhancement on postcontrast T1-weighted images; 2) days 7-10: prominent T2 hyperintensity and contrast enhancement, ADC normalization/pseudonormalization; 3) up to 4 weeks: elevated ADC values, prominent enhancement on postcontrast images; 4) after 4 weeks: partial reversibility of T2 hyperintensity, ADC elevation, and resolution of contrast enhancement. CONCLUSIONS: In a subgroup of patients with MS presenting soon after new symptom onset, a transient reduction of the ADC delineated a short and very early phase of MS lesion evolution. Subsequent pseudonormalization of the ADC occurred along with signs of the development of vasogenic edema.
Diffusion MRI in multiple sclerosis
Neurology, 2005
Background Multiple Sclerosis Multiple sclerosis (MS) is a chronic disease of the CNS that begins most commonly in young adults, and is pathologically characterised by multiple areas of white matter inflammation, demyelination, and gliosis. The clinical course of MS varies from a benign course to a rapidly progressive and disabling disorder. Most patients, however, begin with a relapsing-remitting illness, which is caused by the occurrence of multiple lesions that are disseminated in time as well as in space. However, after 10-20 years or longer, most patients become disabled. MRI is extremely useful in MS, since it can be used to support the diagnosis of MS and to monitor disease evolution in both natural history studies and treatment trials. New MRI techniques Although conventional MRI is the most sensitive paraclinical test in the diagnosis of MS, its specificity is limited. Any pathology from edema and mild demyelination, through to completely necrotic lesions, may show the same abnormal signal. This lack of histopathological specificity accounts, in part, for the modest correlation between clinical disability and MRI parameters, often referred to as the "clinical radiological paradox" [1]. New MRI techniques have been recently developed in order to overcome this limitation, and provide additional in vivo information on the pathological substrates of MS. They showed that MS pathology is not restricted to the demyelinating lesions, but also involves the brain outside the lesions, the so-called normal-appearing white matter (NAWM) and grey matter (NAGM), confirming post-mortem data.
Journal of Neurology, Neurosurgery & Psychiatry, 2001
Objectives-To investigate the relations between quantitative diVusion coeYcient MRI histograms, clinical variables, and cerebral atrophy. Methods-Twenty two patients with clinically definite multiple sclerosis and 11 healthy volunteers were studied. Histograms of apparent diVusion coeYcient (ADC) from a volume of interest that included multiple slices encompassing the lateral ventricles were processed from diffusion weighted MRI. In addition, total lesion load was measured on T2 weighted dual echo images, and cerebral volume from 3D magnetisation prepared rapid acquisition gradient echo scans. All patients underwent neurological assessment, including disability on the expanded disability status scale (EDSS). Results-Histograms from the patient group showed a reduced peak height and a "right shift" compared with healthy controls. Peak height of the diVusion histogram correlated with both EDSS (r=−0.54, p=0.0101) and disease duration (r=−0.52, p=0.0140), but not with age. Brain volume correlated with peak height of the ADC histogram (r=0.55, p=0.0129), but not with disability. Total lesion load also correlated moderately with EDSS (r=0.46, p=0.03). Conclusions-This study shows for the first time that quantitative MRI measures of diVusion correlate with clinical variables (disability, disease duration) and cerebral atrophy in multiple sclerosis. Cerebral atrophy and fixed neurological deficit may be attributed to axonal loss, which would be expected to have a significant eVect on ADC. Extension of this method to more patients and longitudinal studies will further elucidate its sensitivity, reproducibility, and potential role in clinical practice and treatment trials.
Magnetic Resonance in Medicine, 1996
The diffusion characteristics of water in brain white matter were studied in patients with benign and secondary progressive multiple sclerosis (MS), and also in normal controls. In the MS patients, both lesions and normal-appearing white matter (NAWM) were examined to assess whether pathological differences might be evident from the diffusion behavior. A volume-selective technique was used to reduce data acquisition time and improve the reliability and precision of the measurements. This also allowed the time-dependence of apparent diffusion coefficients to be assessed. While lesions from both patient groups showed an elevated diffusion coefficient, no differences between the two groups were found. In addition, NAWM was elevated for both patient groups compared with the control group, although this was only statistically significant for patients with a benign disease course. The degree of elevation of the diffusion coefficient within the individual lesions measured was not related to the disability of the patient. Pathological differences between lesions in patients with different disease courses, if they exist, have not been detected in this study of brain water diffusion.
Turkish Journal Of Neurology, 2022
Objective: To compare diffusion tensor imaging (DTI) findings of the normal-appearing white matter (NAWM) and corpus callosum (CC) in patients with clinically isolated syndrome (CIS) and relapsing-remitting multiple sclerosis (RRMS) and a healthy control (HC) group. Materials and Methods: The CIS (n = 10), RRMS (n = 29), and HC (n = 13) groups were evaluated by DTI in this retrospective study. Mean diffusion (MD) and fractional anisotropy (FA) maps as well as MD and FA measurements were made from the corpus callosum genu (CCG), corpus callosum splenium (CCS), and NAWM areas from the frontal, parietal, occipital and temporal lobes. Results: The mean FA values of the NAWM in the temporal lobes were bilaterally lower in both the CIS and RRMS groups than in the HC group. However, no difference was found between the CIS and RRMS groups. In addition, the CIS group had lower FA values in the CCG, whereas the RRMS group had lower FA values in the CCS compared with the HC group. The MD values were significantly different in the CCG between the RRMS and HC groups. Conclusion: DTI contributes to detecting early changes in the NAWM and CC in patients diagnosed with CIS and RRMS. Additionally, DTI can aid in the follow-up care and management of these patients.