OBJECTIVE: To develop an objective method for quantifying venous vasculature in brain parenchyma on susceptibility-weighted imaging (SWI). To apply this technique in multiple sclerosis (MS) patients and in healthy controls (HC). BACKGROUND: SWI is a MRI application that can directly image cerebral veins by exploiting venous blood oxygenation. DESIGN/METHODS: Sixty-two (62) MS patients (44 relapsing-remitting and 18 secondaryprogressive) and 33 age- and sex-matched HC were imaged on a 3T GE scanner using pre-contrast SWI. A subset of MS patients (50) and HC (7) obtained SWI-post gadolinium contrast sequence (0.1 mMol/Kg Gd-DTPA with 10 min delay). In-house developed segmentation algorithm, based on a 3D multi-scale line filter, was applied for vein segmentation. Absolute volumetric measurement for total vein vasculature was performed in milliliters (ml) and the relative venous intracranial fraction (VIF) was obtained to correct for head size and amount of brain atrophy. The size of individual veins was measured in mm and 4 groups were created according to their mean diameter: 0.9 mm. Voxel brain average distance-from-vein maps was also calculated with higher distance indicating fewer veins. RESULTS: A significantly lower absolute venous volume was detected in MS patients compared to HC, both in pre-contrast (67.5 vs. 82.7ml, -18.3%, p<0.001) and post-contrast (70.4 vs. 87.1ml, 19.1%, p<0.011) images. The VIF was significantly lower in MS patients (p<0.001). The highest mean diameter difference was found for the smallest veins (<0.3 mm), both on pre- (p<0.001) and post-contrast (p<0.018) images. The distance-from-veins was also significantly higher in MS patients (p<0.001). CONCLUSIONS/RELEVANCE: We developed and validated a quantitative vein segmentation method that showed altered visibility of venous vasculature on SWI pre- and post-contrast images in MS patients. These findings suggest severely compromised brain venous system in MS patients.
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, putamen, substantia niagra pars compacta and pars reticulata. Clinical measures included were H&Y, CDR, MoCA, Mini-Mental State Exam (MMSE), and motor Unified Parkinson's Disease Rating Scale (UPDRS). Although non-significant, because of slight differences between groups, age and gender were included as confounders in all statistical models (ANCOVA for group-wise comparisons, linear regression for associative analyses). Analyses were adjusted for multiple comparisons using the false discovery rate method. Results: MCI and non-MCI PD patients did not differ in DGM volumes, mean phase or MP-LPV (all p>.05). Neither the MCI nor the non-MCI group showed significant associations with H&Y, CDR, MoCA, MMSE, or motor UPDRS (p>.05). Conclusion: In contrast to previous accounts, the present study of PD patients with MCI did not show increased tissue magnetic susceptibility. No associations of these measures with clinical status were observed.
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.
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.
MATERIALS AND METHODS:
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.
RESULTS:
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).
CONCLUSION:
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.
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.
RESULTS:
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.
CONCLUSIONS:
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.
Small cell lung cancer (SCLC) is an aggressive and largely immune-cold cancer type, for which chemotherapy combined with Immuno-oncology (IO) therapies is providing benefit only in a subgroup of patients. SCLC is a highly heterogeneous cancer with at least four major subtypes.1 Among them, the 'inflamed' subtype is characterized by an inflamed immune gene signature and high expression of MHC class I (MHC-I) antigen presentation and shows the greatest benefit from the addition of IO treatment to chemotherapy,2 suggesting that MHC-I could serve as a biomarker for IO therapies. Here, we aimed to assess the spatial characteristics of immune cells in MHC-I high SCLC cases to investigate and support its role as a potential biomarker for IO therapies.
Methods
We combined a computational pathology approach with multiplex immunofluorescence (mIF) to profile the SCLC tumor microenvironment (TME). To this end, 126 SCLC formalin-fixed, paraffin-embedded tissue samples were stained with two mIF panels consisting of six markers each: (A) PanCK, CD8, CD68, PD-1, PD-L1, and Ki67; (B) CD20, NKp46, CD1c, CD66b, ICOS, and FOXP3. Based on these panels, we investigated the location and phenotype of each cell in the tumor center and within the stroma and tumor parenchyma. Additional slides from the same tissue blocks were immunohistochemically stained with MHC-I and scored by pathologists. Starting from the observation that high MHC-I expression was associated with higher densities of CD8+ T-cells,3 we further explored the TME characteristics of MHC-I SCLC cases.
Results
Beyond higher densities of CD8+ cytotoxic T-cells, we observed higher densities of FOXP3+ regulatory T-cells, and ICOS+ T-cells in the tumor center of MHC-I high cases. Considering the role of MHC-I in antigen presentation and T-cell activation, we investigated the proportion of CD8;PD-1;Ki67+ T-cells out of all CD8+ cells. Of note, we observed a compelling association of a high proportion of CD8;PD-1;Ki67+ T-cells with high MHC-I. This effect was particularly prominent in the tumor parenchyma and absent in the stroma, revealing an association with functionally relevant presentation of tumor antigens by MHC-I on SCLC tumor cells. Interestingly, we did not observe alterations in other immune cell populations like myeloid dendritic cells, macrophages, and granulocytes.
Conclusions
We utilized computational pathology to comprehensively profile the composition and spatial arrangement of the TME in inflamed SCLC cases defined by high MHC-I expression. Our findings provide the functional rationale for MHC-I as a biomarker for a potentially increased response to IO therapies.4
References
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Ethics Approval
All samples from which data in this report were generated, were obtained from an internal repository. All protocols, amendments, and participant informed consent documents were approved by the appropriate institutional review boards.
We report three cases of dural arteriovenous fistula (DAVF) of the cavernous sinus treated by Onyx injection through the superior pharyngeal branch of the ascending pharyngeal artery. The treatment of choice of DAVFs of the cavernous sinus is endovascular, and it is preferentially done via transvenous occlusion of the cavernous sinus. The cavernous sinus can be reached through either the inferior petrosal sinus or the superior ophthalmic vein. When these venous routes are occluded, the first attempt is to pass through the occluded inferior petrosal sinus, but sometimes this attempt can fail. In some cases there are small transosseous feeders to the fistula arising from the superior pharyngeal branch of the ascending pharyngeal artery. When all of the more conventional approaches are unattainable, this route can be attempted. In our experience, it allowed safe and rapid occlusion of the fistula.
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