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Cerebral microhaemorrhage is a commonly identified neuropathological consequence of mild traumatic brain injury (mTBI) and can be identified in vivo using susceptibility weighted imaging (SWI). This study aimed to determine whether SWI-detected microhaemorrhages are more common in individuals after a single, first-ever, mTBI event relative to trauma controls (TC) and to investigate whether a linear relationship exists between microhaemorrhage numbers and cognition or symptom reporting in the post-acute period after injury, independently of age, psychological status and premorbid level of functioning. Microhaemorrhagic lesions were identified by expert clinical examination of SWI for 78 premorbidly healthy adult participants who were admitted to hospital after a traumatic injury and had suffered a first-ever mTBI (n = 47) or no head strike (n = 31). Participants underwent objective cognitive examination of processing speed, attention, memory, and executive function as well as self-reported post-concussion symptomatology. Bootstrapping analyses were used as data were not normally distributed. Analyses revealed that the mTBI group had significantly more microhaemorrhages than the TC group (Cohen's d = 0.559). These lesions were only evident in 28% of individuals. The mTBI participants demonstrated a significant linear association between number of microhaemorrhages and processing speed, independently of age, psychological status, or premorbid level of functioning. This study shows that a single mTBI causes cerebral microhaemorrhages to occur in a minority of premorbidly healthy individuals. Greater microhaemorrhage count is independently associated with slower processing speed, but not symptom reporting, during the post-acute injury period. [ABSTRACT FROM AUTHOR]

CMBs are the accumulations in the brain vessels of many aged and stroke-affected persons. The presence of CMBs may lead to dementia, traumatic brain injury, and other physiological complications leading them to confusing behavior. Tracking of CMBs from the human brain is challenging due to their small size, manual detection by neurologists may lead to delusions. In this paper, we propose a newfangled technique for feature extraction in the detection of CMB, namely the Edge Emphasized Weber Maximum Directional Co-occurance Matrix (EEWMDCM). Our proposed methodology efficiently recognizes the CMB from magnetic resonance images by integrating the WLD with the notions of the Directional Co-occurance Matrix. When compared with the previous works that occupied many handpicked ROIs selections, more useful features can be extracted in our proposed work from the segmented images that progress the accuracy rate in the detection process. Noise removal filters are utilized and the segmentation is done to identify the candidate in the preprocessing stage which strengthens the feature extraction stage. The features that are extracted from the feature extraction stage are classified and experimented with a set of classifiers, the Support Vector Machine (SVM), Cosine Distance (CO) classifier, Chi-square (CS) classifier, Extreme Learning Machine (ELM), and Convolutional Neural Network (CNN) classifier. The proposed work has been verified and validated on an SWI-CMB dataset that was captured from 320 subjects, in which the images from 230 subjects are for training and images from 90 subjects are for testing purposes. The experiential results specify that our proposed work gives the best sensitivity of 97.11%, the precision of 97.31%, specificity of 97.24%, and an accuracy of 98.06%. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to observe the changes of venous continuity using the susceptibility weighted imaging-minimum intensity projection (SWI-MinIP) images in children with primary headache. Methods: The headache types were classified following the International Headache Society's diagnostic criteria. Patients with secondary headaches were excluded. The presence of asymmetric vasculature in SWI-MinIP images was visually assessed. Moreover, the relationship between headache patterns and asymmetric hypointense signals was analyzed. Results: In this single-center, retrospective study from 2016 to 2020, among 251 cases of primary headache (male/female, 108/143; mean age, 11.4 ± 4.0 years), 137 (54.6%), 75 (29.9%), and 39 (15.5%) patients had migraine, tension-type headache, and other primary headaches, respectively. On SWI-MinIP images, 14 (5.6%) patients showed an asymmetric venous pattern. All patients with SWI-MinIP asymmetry were included in the migraine group, accounting for 10.2% of patients with migraine. Five (35.7%) and nine (64.3%) patients were included in the aura and non-aura groups, respectively, without a significant difference in the frequency of asymmetric hypointense signals between the two groups (p = 0.325). All 14 patients with asymmetric hypervascularity had brain MRI within 12 h of headache onset. Ten (71.4%) of the 14 patients showed consistency between the laterality of headache and the hemisphere of predominant vascularity in SWI-MinIP. Conclusion: Patients with migraine had increased cerebral venous perfusion in the most involved region of the headache on the SWI-MinIP view on a 3.0 T scanner, which can be used as a qualitative indicator with low sensitivity and high specificity for the diagnosis of primary headache in the acute phase (< 12 h). [ABSTRACT FROM AUTHOR]

Objective: Brain calcifications are associated with several neurodegenerative diseases. Here, we describe the occurrence of intracranial calcifications as a new phenotype in transgenic P301L mice overexpressing four repeat tau, a model of human tauopathy. Materials and methods: Thirty-six P301L mice (Thy1.2) and ten age-matched non-transgenic littermates of different ages were assessed. Gradient echo data were acquired in vivo and ex vivo at 7 T and 9.4 T for susceptibility-weighted imaging (SWI) and phase imaging. In addition, ex vivo micro-computed tomography (μCT) was performed. Histochemistry and immunohistochemistry were used to investigate the nature of the imaging lesions. Results: SW images revealed regional hypointensities in the hippocampus, cortex, caudate nucleus, and thalamus of P301L mice, which in corresponding phase images indicated diamagnetic lesions. Concomitantly, µCT detected hyperdense lesions, though fewer lesions were observed compared to MRI. Diamagnetic susceptibility lesions in the hippocampus increased with age. The immunochemical staining of brain sections revealed osteocalcin-positive deposits. Furthermore, intra-neuronal and vessel-associated osteocalcin-containing nodules co-localized with phosphorylated-tau (AT8 and AT100) in the hippocampus, while vascular osteocalcin-containing nodules were detected in the thalamus in the absence of phosphorylated-tau deposition. Discussion: SWI and phase imaging sensitively detected intracranial calcifications in the P301L mouse model of human tauopathy. [ABSTRACT FROM AUTHOR]

The purpose of this study was to noninvasively evaluate the changes of regional cerebral venous oxygen saturation (rSvO2) in hemodialysis patients using quantitative susceptibility mapping (QSM) and investigate the relationship with clinical risk factors and neuropsychological testing. Fifty four (54) hemodialysis patients and 54 age, gender and education matched healthy controls (HCs) were recruited in this prospective study. QSM data were reconstructed from the original phase data of susceptibility weighted imaging to measure the susceptibility of cerebral regional major veins in all subjects and calculate their rSvO2. The differences in rSvO2 between hemodialysis patients and HCs were investigated using analysis of covariance adjusting for age and gender as covariates. Stepwise multiple regression and correlation analysis were performed between the cerebral rSvO2 and clinical factors including neuropsychological testing. The SvO2 of the bilateral cortical, thalamostriate, septal, cerebral internal and basal veins in hemodialysis patients was significantly lower than that in HCs (p < 0.001, Bonferroni corrected). The cerebral rSvO2 in all these veins was reduced by 1.67% to 2.30%. The hematocrit, iron, glucose, pre-and post-dialysis diastolic blood pressure (DBP) were independent predictive factors for the cerebral rSvO2 (all P < 0.05). The Mini-Mental State Examination and Montreal Cognitive Assessment (MoCA) scores were both lower in patients than those in HCs (both P < 0.05). The SvO2 of the left cerebral internal vein correlated with MoCA scores (r = 0.492; P = 0.02, FDR corrected). In conclusion, our study indicated that the cerebral rSvO2 was reduced in hemodialysis patients, which was the risk factor for neurocognitive impairment. The hematocrit, iron, glucose, pre-and post-dialysis DBP were independent risk factors for the cerebral rSvO2. [ABSTRACT FROM AUTHOR]

Although there are several case reports of progressive multifocal leukoencephalopathy (PML) in multiple myeloma (MM), there are few reports of cases associated with pomalidomide. Here, we report the case of a 69-year-old female who had received 41 cycles of pomalidomide and dexamethasone treatment for relapsed/refractory IgG-κ MM presented with right-hand weakness; she was diagnosed as pomalidomide-associated PML. Fluid-attenuated inversion recovery (FLAIR) on admission showed high signals in the bilateral front-parietal lobe white matter, with multiple punctate lesions in the vicinity of the main lesions. These punctate pattern findings on FLAIR were similar to that of natalizumab-associated PML. Susceptibility weighted imaging (SWI) showed hypointense rims within the cortex at unaffected sites, in the initial stages. Subsequently, the clinical manifestations deteriorated, and the FLAIR images showed new hyperintense white matter lesions at the sites where cortical SWI hypointense rims were detected on the initial MRI examination. Our patient's serial MRI findings suggest that cortical SWI hypointense rims appear prior to the visible demyelinating white matter lesions in patients with PML. [ABSTRACT FROM AUTHOR]

Objectives: Asymmetrically prominent veins (APVs) detected on susceptibility weighted imaging (SWI) in acute stroke patients are assumed to signify compromised cerebral perfusion. We aimed to explore the role of APVs in identifying the ischemic penumbra and predicting stroke progression in acute stroke patients Methods: Twenty patients with a middle cerebral artery ischemic infarction presenting within 24 h of symptoms onset underwent SWI following our standard MR stroke protocol imaging sequences which included diffusion-weighted imaging (DWI). Follow-up (FUP) FLAIR images were obtained at least 5 days after the initial MRI study. The Alberta Stroke Program Early CT Score (ASPECTS) was used to determine the initial infarct size, extent of APVs and final infarct size on initial DWI, SWI, and FUP images respectively. For each patient, SWI was compared with DWI images to determine match/mismatch of their respective ASPECTS values and calculate mismatch scores, whereas acute DWI findings were compared with follow-up images to identify infarct growth (IG) and calculate infarction growth scores (IGS). Results: IG occurred in 6/10 patients with a positive DWI-SWI mismatch and in none of the patients without a positive DWI-SWI mismatch. A positive DWI/SWI mismatch was significantly associated with IG (χ2 = 8.57, p = 0.0138, Cramer's V = 0.65). A significant inverse correlation was found between SWI ASPECTS and IGS (rs = − 0.702, p = 0.001). DWI-SWI mismatch scores were strongly correlated with IGS. (rs = 0.788, p = 0.000) Conclusion: A positive DWI-SWI mismatch is an indicator of the ischemic penumbra and a predictor of infarct expansion if left untreated. [ABSTRACT FROM AUTHOR]

Purpose: White matter hyperintensities (WMH) and cerebral microbleeds (CMBs) are known to be associated with small vessel diseases (SVD) and neuroinflammation. The purpose was to investigate the relationship between CMBs and WMH in patients with systemic lupus erythematosus (SLE).Methods: Thirty-one SLE patients with WMH and 27 SLE patients with normal brain MRI were compared. The presence, location, and grading of CMBs were assessed using susceptibility-weighted images. WMH volume was quantitatively measured. Clinical characteristics and serologic markers were compared. We also performed two separate subgroup analyses after (1) dividing WMH into inflammatory lesion vs. SVD subgroups and (2) dividing WMH into those with vs. without CMB subgroups.Results: The WMH group showed more frequent CMBs than the normal MR group (p < 0.001). The WMH group showed higher SLE disease activity index, longer disease duration, and a higher incidence of antiphospholipid syndrome than the normal MR group (p = 0.02, 0.04, and 0.04, respectively). There was a moderate correlation between WMH volume and CMB grading (r = 0.49, p = 0.006). Within the WMH group, the inflammatory lesion subgroup showed more frequent CMBs and larger WMH volume than the SVD subgroup (p < 0.001 and 0.02, respectively). The WMH with CMB subgroup had larger WMH volume than the WMH without CMB subgroup (p = 0.004).Conclusion: In patients with SLE, CMBs could be related to large-volume WMH and inflammatory lesions. CMBs along with severe WMH could be used as an imaging biomarker of vasculitis in patients with SLE. [ABSTRACT FROM AUTHOR]

It is important to detect cerebral microbleed voxels from the brain image of cerebral autosomal-dominant arteriopathy with subcortical infarcts and Leukoencephalopathy (CADASIL) patients. Traditional manual method suffers from intra-observe and inter-observe variability. In this study, we used the susceptibility weighted imaging (SWI) to scan 10 CADASIL patients and 10 healthy controls. We used slicing neighborhood processing (SNP) to extract “input” and “target” dataset from the 20 brain volumetric images. Afterwards, the undersampling technique was employed to handle the class-imbalanced problem. The single-hidden layer feedforward neural-network with scaled conjugate gradient was used as the classifier. We compared three activation functions: logistic sigmoid (LOSI), rectified linear unit (ReLU), and leaky rectified linear unit (LReLU). Early stopping and K-fold cross validation (CV) was used to avoid overfitting and statistical analysis. In the experiment, we generated 68,847 CMB voxels, and 68,829 non-CMB voxels. We observed that LReLU achieved the best result with a sensitivity of 93.05%, a specificity of 93.06%, and an accuracy of 93.06%. We also observed the effect of early stopping and K-fold CV. We found the optimal number of hidden neuron was 10 by grid searching method. Besides, our method performs better than three state-of-the-art methods. The results show our method is promising. In addition, LReLU is a better activation function that may replace traditional logistic sigmoid function in other applications. [ABSTRACT FROM AUTHOR]

Background: It is unclear which magnetic resonance imaging (MRI) sequence most accurately corresponds with the electrophysiological subthalamic nucleus (STN) obtained during microelectrode recording (MER, MER-STN). CT/MRI fusion allows for comparison between MER-STN and the STN visualized on preoperative MRI (MRI-STN). Objective: To compare dorsal and ventral STN borders as seen on 3-Tesla T2-weighted (T2) and susceptibility weighted images (SWI) with electrophysiological STN borders in deep brain stimulation (DBS) for Parkinson's disease (PD). Methods: Intraoperative CT (iCT) was performed after each MER track. iCT images were merged with preoperative images using planning software. Dorsal and ventral borders of each track were determined and compared to MRI-STN borders. Differences between borders were calculated. Results: A total of 125 tracks were evaluated in 45 patients. MER-STN started and ended more dorsally than respective dorsal and ventral MRI-STN borders. For dorsal borders, differences were 1.9 ± 1.4 mm (T2) and 2.5 ± 1.8 mm (SWI). For ventral borders, differences were 1.9 ± 1.6 mm (T2) and 2.1 ± 1.8 mm (SWI). Conclusions: Discrepancies were found comparing borders on T2 and SWI to the electrophysiological STN. The largest border differences were found using SWI. Border differences were considerably larger than errors associated with iCT and fusion techniques. A cautious approach should be taken when relying solely on MR imaging for delineation of both clinically relevant STN borders. [ABSTRACT FROM AUTHOR]

Cerebral venous oxygen saturation (SvO) is an important indicator of brain function. There was debate about lower cerebral oxygen metabolism in hemodialysis patients and there were no reports about the changes of deep regional cerebral SvO in hemodialysis patients. In this study, we aim to explore the deep regional cerebral SvO from straight sinus using quantitative susceptibility mapping (QSM) and the correlation with clinical risk factors and neuropsychiatric testing 52 hemodialysis patients and 54 age-and gender-matched healthy controls were enrolled. QSM reconstructed from original phase data of 3.0 T susceptibility-weighted imaging was used to measure the susceptibility of straight sinus. The susceptibility was used to calculate the deep regional cerebral SvO and compare with healthy individuals. Correlation analysis was performed to investigate the correlation between deep regional cerebral SvO, clinical risk factors and neuropsychiatric testing. The deep regional cerebral SvO of hemodialysis patients (72.5 ± 3.7%) was significantly lower than healthy controls (76.0 ± 2.1%) ( P < 0.001). There was no significant difference in the measured volume of interests of straight sinus between hemodialysis patients (250.92 ± 46.65) and healthy controls (249.68 ± 49.68) ( P = 0.859). There were no significant correlations between the measured susceptibility and volume of interests in hemodialysis patients ( P = 0.204) and healthy controls ( P = 0.562), respectively. Hematocrit ( r = 0.480, P < 0.001, FDR corrected), hemoglobin ( r = 0.440, P < 0.001, FDR corrected), red blood cell ( r = 0.446, P = 0.003, FDR corrected), dialysis duration ( r = 0.505, P = 0.002, FDR corrected) and parathyroid hormone ( r = −0.451, P = 0.007, FDR corrected) were risk factors for decreased deep regional cerebral SvO in patients. The Mini-Mental State Examination (MMSE) scores of hemodialysis patients were significantly lower than healthy controls ( P < 0.001). However, the deep regional cerebral SvO did not correlate with MMSE scores ( P = 0.630). In summary, the decreased deep regional cerebral SvO occurred in hemodialysis patients and dialysis duration, parathyroid hormone, hematocrit, hemoglobin and red blood cell may be clinical risk factors. [ABSTRACT FROM AUTHOR]

Purpose: Phase imaging provides additional information on multiple sclerosis (MS) lesions and may in combination with mean diffusivity (MD) and magnetization transfer ratio (MTR) help differentiating heterogeneity of MS lesion pathology. Methods: Magnetic resonance imaging (MRI) was performed in 23 MS patients including diffusion tensor imaging (DTI), magnetization transfer imaging (MTI), and SWI. Mean values (MTR, MD, and homodyne filtered phase) from 138 chronic MS lesions and normal appearing white matter (NAWM) were obtained and correlations examined. For explorative analysis, a divisive hierarchical clustering algorithm was applied. Results: Phase characteristics were an independent characteristic of chronic T2 lesions, as MTR and MD were not correlated with phase values (R = − 0.23, R = − 0.18). Dependent on MTR, MD, and phase, cluster analysis led to five lesion groups. Of the two groups with phase values close to NAWM, one presented with highest MD and most severe MTR decrease ( p = 0.01), the other with slight MD increase and MTR decrease. Two lesion groups with highest phase values ( p = 0.01) displayed slightly increased MD and moderate decrease in MTR. Clinical data including EDSS, disease duration, and age did not differ significantly between groups. Conclusions: Increased phase is predominantly detectable in lesions with clear MTR decrease but only moderate MD increase. Phase images seem to represent an independent parameter for MS lesion characterization and may provide additional information on MS lesion heterogeneity. [ABSTRACT FROM AUTHOR]

Introduction: The aims of this study were to observe magnetic resonance imaging (MRI) features and the frequency of hemorrhagic transformation (HT) in patients with acute cerebral infarction and to identify the risk factors of HT. Methods: We first performed multimodal MRI (anatomical, diffusion weighted, and susceptibility weighted) scans on 87 patients with acute cerebral infarction within 24 hours after symptom onset and documented the image findings. We then performed follow-up examinations 3 days to 2 weeks after the onset or whenever the conditions of the patients worsened within 3 days. We utilized univariate statistics to identify the correlations between HT and image features and used multivariate logistical regression to correct for confounding factors to determine relevant independent image features of HT. Results: HT was observed in 17 out of total 87 patients (19.5 %). The infarct size ( p = 0.021), cerebral microbleeds (CMBs) ( p = 0.004), relative apparent diffusion (rADC) ( p = 0.023), and venous anomalies ( p = 0.000) were significantly related with HT in the univariate statistics. Multivariate analysis demonstrated that CMBs (odd ratio (OR) = 0.082; 95 % confidence interval (CI) = 0.011-0.597; p = 0.014), rADC (OR = 0.000; 95 % CI = 0.000-0.692; p = 0.041), and venous anomalies (OR = 0.066; 95 % CI = 0.011-0.403; p = 0.003) were independent risk factors for HT. Conclusions: The frequency of HT is 19.5 % in this study. CMBs, rADC, and venous anomalies are independent risk factors for HT of acute cerebral infarction. [ABSTRACT FROM AUTHOR]

The value of magnetic resonance (MR) imaging for the clinical management of brain tumour patients has greatly increased in recent years through the introduction of functional MR sequences. Previously, MR imaging for brain tumours relied for the most part on contrast-enhanced T1-weighted MR sequences but today with the help of advanced functional MR sequences, the pathophysiological aspects of tumour growth can be directly visualised and investigated. This article will present the pathophysiological background of the MR sequences relevant to neuro-oncological imaging as well as potential clinical applications. Ultimately, we take a look at possible future developments for ultra-high-field MR imaging. [ABSTRACT FROM AUTHOR]

Purpose: Oligodendroglioma are rare pediatric brain tumors. The literature about neuroimaging findings is scant. A correct presurgical diagnosis is important to plan the therapeutic approach. Here, we evaluated the conventional and advanced neuroimaging features in our cohort of pediatric oligodendrogliomas and discuss our findings in the context of the current literature. Methods: Clinical histories were reviewed for tumor grading, neurologic manifestation, treatment, and clinical status at the last follow-up. Neuroimaging studies were retrospectively evaluated for tumor morphology and characteristics on conventional and advanced magnetic resonance imaging (MRI). Results: Five children with oligodendroglioma were included in this study. Four children were diagnosed with a low-grade oligodendroglioma. The location of the tumors included the frontal and temporal lobe in two cases each and the fronto-parietal lobe in one. In all oligodendrogliomas, tumor margins appeared sharp. In the high-grade oligodendroglioma, a cystic and partially hemorrhagic component was seen. In all children, the tumor showed a T1-hypointense and T2-hyperintense signal. The signal intensity on fluid attenuation inversion recovery (FLAIR) images was hyperintense in four and mixed hypo-hyperintense in one child. The anaplastic oligodendroglioma showed postcontrast enhancement and decreased diffusion while the low-grade oligodendrogliomas showed increased diffusion. One low-grade oligodendroglioma showed calcifications on susceptibility weighted imaging. Conclusion: Conventional MRI findings of pediatric oligodendrogliomas are nonspecific. Advanced MRI sequences may differentiate (1) low-grade and high-grade pediatric oligodendrogliomas and (2) pediatric oligodendrogliomas and other brain tumors. [ABSTRACT FROM AUTHOR]

Due to the introduction of advanced functional and spectroscopic magnetic resonance (MR) sequences, MR imaging has gained significant importance in neuro-oncology. In contrast to recent years when neuro-oncological imaging was mostly limited to contrast-enhanced T1-weighted images, advanced MR methods provide direct visualization and assessment of tumor pathophysiology. This article summarizes the most relevant MR methods for neuro-oncological imaging and highlights the pathophysiological background as well as potential clinical applications. Ultimately, this article gives a glimpse into the future and introduces potential applications of ultra-high field MRI. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the feasibility of using susceptibility-weighted imaging (SWI) to discriminate abscesses and necrotic tumours. Methods: Twenty-one patients with pyogenic abscesses, 21 patients with rim-enhancing glioblastomas and 23 patients with rim-enhancing metastases underwent SWI. Intralesional susceptibility signal (ILSS) was analyzed employing both qualitative (QL) and semi-quantitative (SQ) methods. Logistic regression models and receiver operating characteristic analysis were used to demonstrate the discriminating power. Results: In QL analysis, ILSSs were seen in 12 of 21 abscesses, in 20 of 21 glioblastomas, and in 16 of 23 metastases. In SQ analysis, a low degree of ILSS (85.8 %) was in the majority of abscesses and a high degree of ILSS (76.2 %) was in the majority of glioblastomas. SQ model was significantly better than QL model in distinguishing abscesses from glioblastomas ( P < .001). A derived ILSS cutoff grade of 1 or less was quantified as having a sensitivity of 85.7 %, specificity of 90.5 %, accuracy of 88.1 %, PPV of 90.0 %, and NPV of 86.4 % in distinguishing abscesses from glioblastomas. Conclusions: A high-grade ILSS may help distinguish glioblastomas from abscesses and necrotic metastatic brain tumours. The lack of ILSS or low-grade ILSS can be a more specific sign in the imaging diagnosis of abscesses. Key Points: • ILSS of SWI can contribute to differential diagnosis of rim-enhanced mass. • Low-grade ILSS can be a more specific sign in abscesses. • High-grade ILSS may help distinguish necrotic glioblastomas from abscesses. • ILSS spreads across the four ILSS categories in metastases. [ABSTRACT FROM AUTHOR]

Objectives: Susceptibility weighted imaging (SWI) may have the potential to depict the perivenous extent of white matter lesions (WMLs) in multiple sclerosis (MS). We aimed to assess the discriminatory value of the 'central vein sign' (CVS). Methods: In a 3-T magnetic resonance imaging (MRI) study, 28 WMLs in 14 patients with at least one circumscribed lesion >5 mm and not more than eight non-confluent lesions >3 mm were prospectively included. Only WMLs in FLAIR images with a maximum diameter of >5 mm were correlated to their SWI equivalent for CVS evaluation. Results: Five patients fulfilled the revised McDonald criteria for MS and nine patients were given alternative diagnoses. Nineteen MS-WMLs and nine non-MS-WMLs >5 mm were detected. Consensus reading found a central vein in 16 out of 19 MS-WMLs (84 %) and in one out of nine non-MS-WMLs (11 %), respectively. The CVS proved to be a highly significant discriminator ( P < 0.001) between MS-WMLs and non-MS-WMLs with a sensitivity, specificity, positive and negative predictive value and accuracy of 84 %, 89 %, 94 %, 73 % and 86 %, respectively. Inter-rater agreement was good (κ = 0.77). Conclusions: Even though the CVS is not exclusively found in MS-WMLs, SWI may be a useful adjunct in patients with possible MS. Key Points: • MRI continues to yield further information concerning MS lesions. • SWI adds diagnostic information in patients with possible MS. • The 'central vein sign' was predominantly seen in MS lesions. • The 'central vein sign' helps discriminate between MS and non-MS lesions. [ABSTRACT FROM AUTHOR]

To explore the handedness effects on phase asymmetries in deep gray matter of healthy adults by using magnetic susceptibility-weighted imaging (SWI) phase. Thirty left-handed (16 men, 14 women; age range, 20 to 57 years) and 30 age- and sex-matched right-handed (16 men, 14 women; age range, 20 to 58 years) healthy adults were examined at 3.0 T MRI. For each subject, phase values were detected in bilateral frontal white matters (FWM), caudate nucleus (CA), putamen (PU), globus pallidus (GP), thalamus (TH), red nucleus (RN) and substantia nigra (SN) on phase images. Statistical analysis was performed with paired-samples t-test and independent-samples t-test. In both handedness groups, the corrected phase values in the left hemisphere were significantly lower than those in the right one in FWM, CA, PU, GP ( P < 0.05) and there was no significant hemispheric asymmetry in TH, RN and SN ( P > 0.05). Differences in corrected phase values in corresponding brain regions of the same hemisphere between left-handed and right-handed groups were not statistically significant ( P > 0.05). Hemispheric asymmetry of SWI phase in deep gray matter may not associate with handedness in adult brain. [ABSTRACT FROM AUTHOR]

Susceptibility weighted imaging (SWI) is a newly developed magnetic resonance (MR) protocol. Recent studies have found that SWI may be useful in the field of cerebrovascular diseases, especially for detecting the presence of prominent veins, microbleeds and the susceptibility vessel sign (SVS). Some authors have even suggested that SWI can be used to predict outcome. We conducted a prospective study of patients hospitalized with middle cerebral artery territory infarction receiving MRI within 2 days of stroke onset. The presence of prominent veins, microbleeds and SVS in SWI was analyzed along with hospital characteristics of the patients. A total of 44 patients were enrolled. Among the 44 patients, 15 (34.1%) patients showed prominent veins, 19 (43.2%) showed SVS, and 14 (31.8%) showed microbleeds. The presence of SVS and prominent veins was not associated with prognosis. Though not statistically significant ( p = 0.06), patients with SVS were more likely to develop later brain edema. SVS was significantly associated with arterial occlusion ( p = 0.008) based on the MR angiogram, and microbleeds were significantly associated with later hemorrhagic transformation ( p = 0.018). In our study, SWI could not be used to predict outcome as previously suggested. However, the presence of microbleeds may predict further hemorrhagic transformation, and the presence of SVS could be used to detect intra-arterial thrombus. Patients with SVS were also more likely to develop later brain edema. Including SWI in routine MR protocols for major acute ischemic stroke would be worthwhile. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the capability of venography based on MR phase-sensitive imaging (PSI) in the visualization of internal cerebral veins (ICV) and their tributaries, and to concurrently describe their anatomical variants. Patients and methods: A total of 100 consecutive patients underwent PSI MR examination. A minimum intensity projection image from PSI was generated and evaluated by two radiologists. Veins included in this study were ICV, thalamostriate veins (TSV), septal veins (SV), anterior caudate nucleus veins, medial atrial veins and lateral direct veins. Results: With PSI-based venography, we clearly delineated ICV, SV, TSV, anterior caudate nucleus veins, medial atrial veins and lateral direct veins in 100, 98.5, 100, 92.5, 92 and 32% of 200 sides, respectively, within a group of 100 patients. In 80.5% of the sides, the TSV–SV–ICV junction was located adjacent to the posterior margin of the foramen of Monro; in 19.5% the junction was located beyond the foramen of Monro; and in 70.8%, the anterior caudate nucleus veins drained into TSV. In 21.6% of the sides, the SV, TSV and anterior caudate nucleus veins joined together to form the ICV. In 7.6% of the sides, the anterior caudate nucleus veins and TSV separately conjoined with SV or ICV. The pattern that the anterior caudate nucleus veins drain into SV or ICV is more frequent in the sides with TSV–SV–ICV in the posterior location. Of the 64 lateral direct veins, 59.4% of the sides were accompanied by an insufficient development of the TSV and 40.6% sides were normal. Enlarged direct lateral veins frequently accompany an insufficient development of TSV. Conclusions: Phase-sensitive imaging-based venography showed its extraordinary detectability in demonstrating the anatomy and variants of ICV and their tributaries. The advantages of this technique are a relatively short examination time, and a non-invasive and contrast-free procedure. We propose that PSI-based venography may be a promising method to study the anatomy of subependymal veins, especially the tiny and tortuous ones. [ABSTRACT FROM AUTHOR]

Susceptibility-weighted imaging (SWI) is a novel magnetic resonance (MR) technique that exploits the magnetic susceptibility differences of various tissues, such as blood, iron and calcification. This pictorial review covers many clinical conditions illustrating its usefulness. SWI consists of using both magnitude and phase images from a high-resolution, three-dimensional fully velocity-compensated gradient echo sequence. Phase mask is created from the MR phase images, and multiplying these with the magnitude images increase the conspicuity of the smaller veins and other sources of susceptibility effects, which is depicted using minimal intensity projection (minIP). The phase images are useful in differentiating between diamagnetic and paramagnetic susceptibility effects of calcium and blood, respectively. This unique MR sequence will help in detecting occult low flow vascular lesions, calcification and cerebral microbleed in various pathologic conditions and aids in characterizing tumors and degenerative diseases of the brain. This sequence also can be used to visualize normal brain structures with conspicuity. Susceptibility-weighted imaging is useful in differentiating and characterizing diverse brain pathologies. [ABSTRACT FROM AUTHOR]