[Show abstract][Hide abstract] ABSTRACT: Studies have shown a relationship between increased iron content and clinical progression, cognitive impairment, and brain atrophy in patients with multiple sclerosis. Altered phase, as determined by susceptibility-weighted imaging (SWI), can potentially capture iron content changes.
The objective of this study was to investigate phase changes in white matter (WM) lesions and subcortical deep-gray matter (SDGM) of patients with relapsing-remitting (RR) MS treated with interferon beta-1a administered subcutaneously versus untreated healthy controls (HCs).
We conducted a 24-week, nonrandomized, open-label pilot study of 23 patients with RRMS receiving interferon beta-1a administered subcutaneously and 15 HCs. Patients were imaged on a 3T scanner at baseline, 12, and 24 weeks; changes in phase behavior in WM lesions and regional SDGM [mean phase of low-phase voxels (MP-LPV)], and in SDGM volumes, were measured. Between- and within-group changes were tested using nonparametric statistics adjusted for multiple comparisons.
The number (p = 0.003) and volume (p < 0.001) of phase WM lesions both significantly decreased among RRMS patients over 24 weeks. At baseline, MP-LPV was lower (suggestive of greater iron content) in total SDGM among RRMS patients versus HCs (p = 0.002). Week 24 MP-LPV changes from baseline were not significantly different between groups in total SDGM or any region except the putamen (-0.0025 radians in RRMS patients versus 0.0035 radians in HCs; p = 0.041).
Over 24 weeks, phase lesions were reduced significantly in the RRMS group. These preliminary results suggest that SWI-filtered phase may become a useful tool for monitoring RRMS disease activity.
No preview · Article · Mar 2015 · Therapeutic Advances in Neurological Disorders
[Show abstract][Hide abstract] ABSTRACT: Background and purpose:
Identifying MRI biomarkers that can differentiate multiple sclerosis patients from other neurological disorders is a subject of intense research. Our aim was to investigate phase WM signal abnormalities for their presence, prevalence, location, and diagnostic value among patients with clinically isolated syndrome and other neurologic disorders and age-, sex-, and group-matched healthy controls.
Materials and methods:
Forty-eight patients with clinically isolated syndrome and 30 patients with other neurologic diseases and a healthy control group (n = 47) were included in the study. Subjects were scanned at 3T by using SWI-filtered phase and T2WI, with WM signal abnormalities ≥3 mm being classified.
Patients with clinically isolated syndrome had significantly more phase and T2 WM signal abnormalities than healthy controls (P < .001). Phase WM signal abnormalities were more prevalent among patients with clinically isolated syndrome compared with patients with other neurologic disorders (4:1 ratio), whereas T2 WM signal abnormalities were more ubiquitous with a 2:1 ratio. The presence of phase WM signal abnormalities was sensitive for clinically isolated syndrome (70.8%) and achieved a moderate-to-high specificity for differentiating patients with clinically isolated syndrome and healthy controls, patients with other neurologic disorders, and patients with other neurologic disorders of other autoimmune origin (specificity, 70%-76.7%). Combining the presence of ≥2 phase lesions with the McDonald 2005 and 2010 criteria for dissemination in space improved the specificity (90%), but not the accuracy, in differentiating patients with clinically isolated syndrome from those with other neurologic disorders. In subanalyses among patients with clinically isolated syndrome who converted to clinically definite multiple sclerosis versus those who did not within a 3-year follow-up period, converters had significantly more phase (P = .008) but not T2 or T1 WM signal abnormalities.
Phase WM signal abnormalities are prevalent among patients with clinically isolated syndrome. The presence of (multiple) phase WM signal abnormalities tended to be more predictive of conversion to clinically definite multiple sclerosis and was specific in differentiating patients with clinically isolated syndrome and other neurologic disorders, compared with T2 WM signal abnormalities; however, the accuracy remains similar to that of the current McDonald criteria.
Preview · Article · May 2014 · American Journal of Neuroradiology
[Show abstract][Hide abstract] ABSTRACT: Objective: To determine differences in deep gray matter (DGM) magnetic susceptibility using susceptibility-weighted imaging (SWI) in PD patients with- and without mild cognitive impairment (MCI). Associations of these indirect brain-iron measurements with clinical status were assessed.Background: Elevated brain-iron levels have been proposed to play an important role in the pathophysiology of neurodegenerative disorders including Parkinson's disease (PD) and may influence clinical outcomes.Methods: Out of a total sample of 40 PD patients, 23 were classified as MCI, while 17 were not. MCI was defined as having a Hoehn & Yahr (H&Y) stage of 2-4, a Montreal Cognitive Assessment score (MoCA) of ≤25 and a Clinical Dementia Rating (CDR) of 0.5. Using SWI-filtered phase imaging, the mean phase (suggestive of overall iron levels), mean phase of low phase voxels (MP-LPV; suggestive of severe iron pathology) as well as structural volume measurements were derived of 10 DGM structures, including the caudate, putame
[Show abstract][Hide abstract] ABSTRACT: Background and purpose:
It has been demonstrated that increased levels of iron in the brain occur with aging. In this study we investigated the nature of the association between age and SWI-filtered phase values, indicative of iron content, in the subcortical deep gray matter of healthy individuals.
Materials and methods:
A total of 210 healthy individuals (men: n = 89, women: n = 121), mean age, 39.8 years (standard deviation = 15.5; range = 6-76 years), were imaged on a 3T scanner. Mean MRI phase, mean phase of low-phase voxels, and normalized volumes were determined for total subcortical deep gray matter, caudate, putamen, globus pallidus, thalamus, pulvinar nucleus, hippocampus, amygdala, nucleus accumbens, red nucleus, and substantia nigra. Linear and nonlinear regression models were used to explore the relationship between phase and volume measures, and aging.
Mean phase values of subcortical deep gray matter structures showed a quadratic relationship, with individuals in late middle age (40-59 years) having the lowest mean phase values, followed by a reversal of this trend in the elderly. In contrast, mean phase of low-phase voxel measurements showed strong negative linear relationships with aging. Significantly lower phase values were detected in women compared with men (P < .001), whereas no sex differences were observed for mean phase of low-phase voxels. Normalized volume measurements were also linearly related to aging, and women showed smaller normalized volumes of subcortical deep gray matter structures than men (P < .001). Lower mean phase of low-phase voxels was related to decreased volume measures.
A strong association between phase (quadratic effect; phase decreases are followed by increases), mean phase of low-phase voxels (linear effect), volume (linear effect), and age was observed. Low phase was related to brain atrophy.
Full-text · Article · May 2013 · American Journal of Neuroradiology
[Show abstract][Hide abstract] ABSTRACT: The association between clinical outcomes and abnormal susceptibility-weighted imaging (SWI)-filtered phase, indicative of increased iron content, as well as atrophy, was investigated in the subcortical deep-gray matter (SDGM) of multiple sclerosis (MS) patients. 149 relapsing-remitting (RR) and 61 secondary-progressive (SP) MS patients underwent SWI on a 3T scanner. Mean phase of the abnormal phase tissue (MP-APT) and normalized volumes were determined for the total and region-specific SDGM structures. In an age- and gender-adjusted regression model, total SDGM volume was the strongest predictor of Expanded Disability Status Scale (EDSS) (beta = -.224, p<.001), followed by total SDGM MP-APT (beta = -.168, p <.019). This model accounted for 30.4% of the variance in EDSS. Only SDGM MP-APT added additional variance in predicting EDSS, compared to conventional MRI metrics. Caudate and red nucleus MP-APT and amygdala volume were associated with EDSS. Our findings suggest that disability in MS patients is associated better with SDGM pathology, as indicated by increased iron content and atrophy, than with lesion burden or white matter and cortical volumes.
Full-text · Article · Jan 2013 · Frontiers in bioscience (Elite edition)
[Show abstract][Hide abstract] ABSTRACT: To investigate phase lesions identified on susceptibility-weighted imaging (SWI)-filtered phase images in patients with multiple sclerosis (MS), clinically isolated syndrome (CIS) and healthy controls (HC). To relate phase lesion characteristics to other clinical and MRI outcomes.
95 relapsing-remitting (RR), 40 secondary-progressive (SP) MS patients, as well as 19 CIS patients and 49 age- and sex-matched HC, were scanned on a 3T scanner. Phase-, T1-, and T2-lesion characteristics were determined. Overlap of T1- and T2-weighted imaging (WI) lesions with phase lesions (T1P and T2P), as well as brain atrophy outcomes, was assessed.
MS patients showed significantly greater numbers and larger volume of phase lesions, compared with HC (P < 0.001). 23.6% of T2 lesions overlapped with phase lesions, whereas the same figure for T1 lesions was 37.3%. Conversely, 33.4% and 69.7% of phase lesions were not visible on T2- or T1-WI, respectively. Phase, T1P and T2P lesions were not related to clinical outcomes, but phase lesions were related to ventricular enlargement.
Phase lesions were present in both MS and CIS patients, and showed partial overlap with lesions observed using conventional MRI. The role of phase lesions in clinical progression remains unclear and should be further explored.
Full-text · Article · Apr 2012 · Journal of Magnetic Resonance Imaging
[Show abstract][Hide abstract] ABSTRACT: Increasing evidence suggests that iron deposition is present in the later stages of MS. In this study we examined abnormal phase values, indicative of increased iron content on SWI-filtered phase images of the SDGM in CIS patients and HC. We also examined the association of abnormal phase with conventional MR imaging outcomes at first clinical onset.
Forty-two patients with CIS (31 female, 11 male) and 65 age and sex-matched HC (41 female, 24 male) were scanned on a 3T scanner. Mean age was 40.1 (SD = 10.4) years in patients with CIS, and 42.8 (SD = 14) years in HC, while mean disease duration was 1.2 years (SD = 1.3) in patients with CIS. MP-APT, NPTV, and normalized volume measurements were derived for all SDGM structures. Parametric and nonparametric group-wise comparisons were performed, and associations were determined with other MR imaging metrics.
Patients with CIS had significantly increased MP-APT (P = .029) and MP-APT volume (P = .045) in the pulvinar nucleus of the thalamus compared with HC. Furthermore, the putamen (P = .004), caudate (P = .035), and total SDGM (P = .048) displayed significant increases in MP-APT volume, while MP-APT was also significantly increased in the putamen (P = .029). No global or regional volumetric MR imaging differences were found between the study groups. Significant correlations were observed between increased MP-APT volumes of total SDGM, caudate, thalamus, hippocampus, and substantia nigra with white matter atrophy and increased T2 lesion volume (P < .05).
Patients with CIS showed significantly increased content and volume of iron, as determined by abnormal SWI-phase measurement, in the various SDGM structures, suggesting that iron deposition may precede structure-specific atrophy.
Full-text · Article · Mar 2012 · American Journal of Neuroradiology
[Show abstract][Hide abstract] ABSTRACT: To determine the effects of intravenous natalizumab and intramuscular interferon beta-1a (IFNβ-1a) on the volume of white-matter (WM) lesions and normal appearing brain tissue (NABT) undergoing voxel-wise (VW) increases in magnetization transfer ratio (MTR) suggestive of remyelination in patients with relapsing multiple sclerosis.
This prospective, open-label, single-blinded study enrolled patients with relapsing-remitting multiple sclerosis (RRMS) and relapsing secondary progressive multiple sclerosis (RSPMS) as well as a group of age/sex-matched healthy controls (n=22). Patients with multiple sclerosis were assigned to receive natalizumab monotherapy (n=77; RRMS/RSPMS) or intramuscular IFNβ-1a (n=26) as either monotherapy (RRMS) or combined with pulsed i.v. methylprednisolone, as needed (RSPMS). The primary endpoint was the two-year change in volume of NABT VWMTR, by quantifying the number of voxels that increased (suggesting remyelination) or decreased (suggesting demyelination) in their MTR value.
The volume of tissue undergoing increases in VWMTR was significantly larger in natalizumab compared with IFNβ-1a-treated patients (year 1: p=0.001 in NABT and p<0.006 in WM lesions; year 2: p=0.008 in NABT) and compared with healthy control subjects (year 1: p=0.05 and year 2: p=0.007 in NABT). The larger volume within NABT undergoing decreases in VWMTR was detected in multiple sclerosis patients compared with healthy controls (p<0.001), and in the IFNβ-1a group compared with the natalizumab group (year 1: p=0.05; year 2: p=0.002). One patient on natalizumab died from progressive multifocal leukoencephalopathy eight months after completing the study.
Natalizumab may promote remyelination and stabilize demyelination in lesions and NABT in relapsing multiple sclerosis, compared with intramuscular IFNβ-1a.
No preview · Article · Dec 2011 · Multiple Sclerosis
[Show abstract][Hide abstract] ABSTRACT: To investigate abnormal phase on susceptibility-weighted imaging (SWI)-filtered phase images indicative of iron content, in subcortical deep-gray matter (SDGM) of multiple sclerosis (MS) patients and healthy controls (HC), and to explore its relationship with MRI outcomes.
169 relapsing-remitting (RR) and 64 secondary-progressive (SP) MS patients, and 126 age- and sex-matched HC were imaged on a 3T scanner. Mean phase of the abnormal phase tissue (MP-APT), normal phase tissue volume (NPTV) and normalized volume were determined for total SDGM, caudate, putamen, globus pallidus, thalamus, pulvinar nucleus of thalamus (PVN), hippocampus, amygdala, nucleus accumbens, red nucleus and substantia nigra. 63 HC were used for establishment of normal reference phase values, while additional 63 HC were used for blinded comparisons with MS patients.
Increased MP-APT, decreased normalized volume and decreased NPTV were detected in total SDGM, caudate, putamen, globus pallidus, thalamus and PVN in MS patients compared to HC (p<.0004). MS patients also showed decreased volume in hippocampus (<.0001) and decreased NPTV in the hippocampus, amygdala and accumbens (<.0004). SPMS patients had increased MP-APT, decreased volume and decreased NPTV in total SDGM, caudate and amygdala compared to RRMS (p<.005), while individual measure differences were also detected in putamen, thalamus, hippocampus and accumbens (p<.006). RRMS patients showed a significant relationship between increased MP-APT and increased lesion burden and more advanced brain atrophy (p<.004).
Abnormal phase, indicative of higher iron content was significantly increased in MS patients compared to HC, and was related to more severe lesion burden and brain atrophy.
[Show abstract][Hide abstract] ABSTRACT: Information-processing speed (IPS) slowing is a primary cognitive deficit in multiple sclerosis (MS). Basal ganglia, thalamus and neocortex are thought to have a key role for efficient information-processing, yet the specific relative contribution of these structures for MS-related IPS impairment is poorly understood. To determine if basal ganglia and thalamus atrophy independently contribute to visual and auditory IPS impairment in MS, after controlling for the influence of neocortical volume, we enrolled 86 consecutive MS patients and 25 normal controls undergoing 3T brain MRI and neuropsychological testing. Using Sienax and FIRST software, neocortical and deep gray matter (DGM) volumes were calculated. Neuropsychological testing contributed measures of auditory and visual IPS using the Paced Auditory Serial Addition Test (PASAT) and the Symbol Digit Modalities Test (SDMT), respectively. MS patients exhibited significantly slower IPS relative to controls and showed reduction in neocortex, caudate, putamen, globus pallidus, thalamus and nucleus accumbens volume. SDMT and PASAT were significantly correlated with all DGM regions. These effects were mitigated by controlling for the effects of neocortical volume, but all DGM volumes remained significantly correlated with SDMT, putamen (r = 0.409, p < 0.001) and thalamus (r = 0.362, p < 0.001) having the strongest effects, whereas for PASAT, the correlation was significant for putamen (r = 0.313, p < 0.01) but not for thalamus. We confirm the significant role of thalamus atrophy in MS-related IPS slowing and find that putamen atrophy is also a significant contributor to this disorder. These DGM structures have independent, significant roles, after controlling for the influence of neocortex atrophy.
No preview · Article · Jul 2011 · Journal of Neurology
[Show abstract][Hide abstract] ABSTRACT: The associations between vitamin D and MRI measures of brain tissue injury have not been previously investigated in multiple sclerosis (MS). This research evaluates the significance of vitamin D and its active metabolites in brain tissue injury and clinical disability in MS patients.
The study population consisted of 193 MS patients (152 women and 41 men; mean age 46.1 (SD 8.4) years; disease duration 13.8 (SD 8.4) years). Serum levels of 25-hydroxyvitamin D(3) (25(OH)VD(3)), 25-hydroxyvitamin D(2) (25(OH)VD(2)), 1α, 25-dihydroxyvitamin D(3) (1, 25(OH)(2)VD(3)) and 24(R), 25-dihydroxyvitamin D(3) (24, 25(OH)(2)VD(3)) were measured using a novel capillary liquid-chromatography-mass spectrometry method. Disability was assessed with the Expanded Disability Status Scale (EDSS) and the MS Severity Scale (MSSS). MRI measures included T2 lesion volume (LV), T1-LV and brain parenchymal fraction. The associations between deseasonalised levels of vitamin D metabolites and clinical and MRI measurements were assessed using regression analyses.
Lower deseasonalised levels of total 25(OH)VD (p=0.029), 25(OH)VD(3) (p=0.032) and 24, 25(OH)(2)VD(3) (p=0.005) were associated with higher MSSS. Similarly, lower deseasonalised levels of 24, 25(OH)(2)VD(3) (p=0.012) were associated with higher EDSS. Higher values of the 25(OH)VD(3) to 24, 25(OH)(2)VD(3) ratio were associated with higher MSSS (p=0.041) and lower brain parenchymal fraction (p=0.008).
Vitamin D metabolites have protective associations with disability and brain atrophy in MS. In particular, the results indicate strong associations for the 24, 25(OH)(2)VD(3) metabolite, which has not been extensively investigated in MS patients.
No preview · Article · Nov 2010 · Journal of neurology, neurosurgery, and psychiatry
[Show abstract][Hide abstract] ABSTRACT: Chronic cerebrospinal venous insufficiency (CCSVI) is a vascular phenomenon recently described in multiple sclerosis (MS) that is characterized by stenoses affecting the main extracranial venous outflow pathways and by a high rate of cerebral venous reflux that may lead to increased iron deposition in the brain. Aim of this study was to investigate the relationship between CCSVI and iron deposition in the brain of MS patients by correlating venous hemodynamic (VH) parameters and iron concentration in deep-gray matter structures and lesions, as measured by susceptibility-weighted imaging (SWI), and to preliminarily define the relationship between iron measures and clinical and other magnetic resonance imaging (MRI) outcomes.
Sixteen (16) consecutive relapsing-remitting MS patients and 8 age- and sex-matched healthy controls (HC) were scanned on a GE 3T scanner, using SWI.
All 16 MS patients fulfilled the diagnosis of CCSVI (median VH=4), compared to none of the HC. In MS patients, the higher iron concentration in the pulvinar nucleus of the thalamus, thalamus, globus pallidus, and hippocampus was related to a higher number of VH criteria (P<0.05). There was also a significant association between a higher number of VH criteria and higher iron concentration of overlapping T2 (r=-0.64, P=0.007) and T1 (r=-0.56, P=0.023) phase lesions. Iron concentration measures were related to longer disease duration and increased disability as measured by EDSS and MSFC, and to increased MRI lesion burden and decreased brain volume.
The findings from this pilot study suggest that CCSVI may be an important mechanism related to iron deposition in the brain parenchyma of MS patients. In turn, iron deposition, as measured by SWI, is a modest-to-strong predictor of disability progression, lesion volume accumulation and atrophy development in patients with MS.
Full-text · Article · Apr 2010 · International angiology: a journal of the International Union of Angiology