Susceptibility-weighted Imaging Sequences Research Articles

Radiation diagnostics of cerebral cavernous malformations

Cerebral cavernous malformations are a fairly common vascular pathology at the moment, with the number of detected cases increasing dramatically in recent years. This is because modern neuroimaging methods such as computed tomography (CT) and magnetic resonance imaging (MRI) have been introduced into clinical practice and are widely available. Prior to the advent of CT and MRI technologies, it was extremely difficult to diagnose this pathology, and the diagnosis was usually made intraoperatively or based on autopsy data. Further, the literature review is devoted to the radiological diagnosis of cerebral cavernous malformations (CM). The role of neuroimaging methods in the diagnosis of cavernous malformations, as well as the use of MRI for CM visualization, was analyzed. The advantages of MRI over other neuroimaging methods for this pathology have been demonstrated. Pulse sequences of MRI and signaling characteristics of various foci were characterized, depending on the morphological substrate. The significance of the susceptibility-weighted imaging sequence was also evaluated for the detection of multifocal lesions in cases of familial CM. The study of the main pulse sequences of MRI for visualization of CM will improve the protocol algorithm for the timely diagnosis of this pathology and the selection of therapeutic approach.

Multiple sclerosis: prevalence of the 'central vein' sign in white matter lesions on gadolinium-enhanced susceptibility-weighted images.

To evaluate prospectively whether an intravenous gadolinium injection could improve the detection of the central vein sign on susceptibility-weighted imaging sequences obtained with a 1.5 T magnetic resonance scanner in patients with multiple sclerosis compared to unenhanced susceptibility-weighted images. This prospective, institution review board-approved study included 19 patients affected by multiple sclerosis (six men; 13 women; mean age 40.8 years, range 20-74 years). Patients had the relapsing-remitting clinical subtype in 95% of cases, and only one (5%) patient had the primary progressive clinical subtype of multiple sclerosis. T2-weighted images, fluid-attenuated inversion recovery images, unenhanced and contrast-enhanced susceptibility-weighted images were evaluated in consensus by two neuroradiologists for the presence of the central vein sign. The readers were blinded to magnetic resonance imaging reports, clinical information, the presence and the localisation of focal hyperintense white matter lesions. Any discordance between readers was resolved through a joint review of the recorded images with an additional neuroradiologist. A total of 317 multiple sclerosis lesions were analysed. The central vein sign had a higher prevalence detection rate on gadolinium-enhanced susceptibility-weighted images (272 of 317 lesions, 86%) compared to unenhanced susceptibility-weighted images (172 of 317 lesions, 54%). Gadolinium-enhanced susceptibility-weighted imaging improves the detection rate of the central vein sign in multiple sclerosis lesions.

Intratumoral microhemorrhage detection on susceptibility-weighted imaging can help in preoperative differentiation of cerebellopontine angle vestibular schwannomas from meningiomas: Correlation with pathology findings

Objectives: In this study, we aimed to evaluate whether intratumoral microhemorrhage detection on susceptibility-weighted imaging (SWI) could help in preoperative differentiation of cerebellopontine angle (CPA) vestibular schwannomas (VSs) from meningiomas. Patients and Methods: A total of 75 patients (32 males, 43 females; mean age: 45.5±16.7 years; range, 17 to 68 years) consisting of 61 VSs and 14 meningiomas located in the CPA cistern were retrospectively analyzed. All patients underwent contrast-enhanced magnetic resonance imaging (MRI) using the SWI sequence. All images in our study were obtained with a 12-channel phased-array head coil on a 1.5-Tesla clinical scanner. The presence of intratumoral microhemorrhages on SWI sequence was evaluated by demonstrating blooming artifacts as punctate hypointense regions. Both magnitude and phase-contrast images were used to verify microhemorrhages. All patients in our patient cohort underwent surgery and resected tumor specimens were evaluated by pathology. Results: All VS cases in our cohort exhibited multiple hypointense small foci causing blooming artifact on magnitude and processed SWI images. In the meningioma population, typical MRI signal intensity characteristics, including an intense homogenous contrast enhancement, were observed. In all the meningioma cases, except for one, there was no blooming artifact due to intratumoral hemorrhage within the mass lesions on SWI images. In only one meningioma case, SWI revealed hypointense microhemorrhages within the mass lesion. Following surgical procedures and tumor resections, pathology specimens were evaluated and absence or presence of intratumoral microhemorrhages were detected. These results were significantly correlated with the SWI findings. We obtained 100% sensitivity, 92.8% specificity, and 98.6% accuracy in terms of differentiating VSs from meningiomas located in the CPA cistern by using the SWI sequence. Conclusion: Meningiomas and VSs are the two most common masses of the CPA cistern and, in some cases, it seems to be difficult to reach an accurate diagnosis with conventional MRI sequences. The SWI can be helpful to solve this problem by demonstrating whether intratumoral microhemorrhages are present or not within mass lesions and, thus, can help to assume a probable accurate diagnosis prior to surgery

Abstract P431: White-Matter Disease Burden and Cerebral Microbleeds After Extracorporeal Membrane Oxygenation Support

Introduction: Cerebral microbleeds (CMBs) have been increasingly reported in patients receiving extracorporeal membrane oxygenation (ECMO) support. Both, CMBs and cerebral white-matter disease (WMD) are thought to be a result of microvascular lipo-hyalinosis; as commonly seen in an aging brain. The pathogenesis of microbleeds after ECMO, has not yet been definitively established. We sought to examine the relationship between cerebral WMD burden and microbleeds after ECMO-support at a single tertiary referral academic hospital with high volumes of ECMO patients. Methods: All patients receiving venovenous (vv) and venoarterial (va) ECMO between January 2013 to January 2018 were retrospectively examined. The distribution of white matter hyperintensities was quantified using the Walhund age-related white matter changes (ARWMC) scale and correlated with the presence of cerebral microbleeds on brain MRI studies with Susceptibility Weighted Imaging (SWI) performed shortly after cessation of ECMO. Results: A total of 307 ECMO patients were reviewed, among whom 44 patients (vv:va= 13:31; male:female= 29:15) received at-least one MRI-brain study with SWI sequences after ECMO decannulation. The median duration of ECMO support was 4 days (range 1-25 days), with median duration from decannulation-to-MRI being 11.5 days (range 3-724 days). Microbleeds were present in 77.3% (n=34) patients, with 38.2% (n=13), 14.7% (n=5), and 47.1% (n=16) having mild (<10), moderate (10-30) and severe (>30) CMBs respectively. The median Walhund ARWMC score was 1 (range 0-22). Age and sex adjusted Walhund scores were not found predictive of CMB presence (p=0.578 [0.90-1.19]). Of 44 patients with at-least one post-ECMO MRI, 10 patients had a follow-up MRI scan at a median duration of 4 months (range 0.22-55 months); all of whom had unchanged CMB burden. At 10-month median clinical follow-up (range 0-76 months), none of the 34 patients with CMBs on initial MRI-study had presented with an intracranial hemorrhage. Conclusion: Development of CMBs after ECMO support is independent of microvascular lipo-hyalinosis, as estimated from cerebral white-matter disease burden. This requires further study in a larger sample-size.

Susceptibility-weighted Imaging: Technical Essentials and Clinical Neurologic Applications.

Susceptibility-weighted imaging (SWI) evolved from simple two-dimensional T2*-weighted sequences to three-dimensional sequences with improved spatial resolution and enhanced susceptibility contrast. SWI is an MRI sequence sensitive to compounds that distort the local magnetic field (eg, calcium and iron), in which the phase information can differentiate. But the term SWI is colloquially used to denote high-spatial-resolution susceptibility-enhanced sequences across different MRI vendors and sequences even when phase information is not used. The imaging appearance of SWI and related sequences strongly depends on the acquisition technique. Initially, SWI and related sequences were mostly used to improve the depiction of findings already known from standard two-dimensional T2*-weighted neuroimaging: more microbleeds in patients who are aging or with dementia or mild brain trauma; increased conspicuity of superficial siderosis in Alzheimer disease and amyloid angiopathy; and iron deposition in neurodegenerative diseases or abnormal vascular structures, such as capillary telangiectasia. But SWI also helps to identify findings not visible on standard T2*-weighted images: the nigrosome 1 in Parkinson disease and dementia with Lewy bodies, the central vein and peripheral rim signs in multiple sclerosis, the peripheral rim sign in abscesses, arterial signal loss related to thrombus, asymmetrically prominent cortical veins in stroke, and intratumoral susceptibility signals in brain neoplasms.

Association between infectious burden and cerebral microbleeds: a pilot cross‐sectional study

ObjectiveCerebral microbleeds (CMBs) is a subtype of cerebral small vessel disease. Their underlying pathogenesis remains unclear. The aim of this study was to investigate the association between infectious burden (IB) and CMBs.MethodsSeven hundred and seventy‐three consecutive patients who were hospitalized in the Department of Neurology in General Hospital of Western Theater Command without severe neurological symptoms were recruited and selected in this pilot cross‐sectional study. CMBs were assessed using the susceptibility‐weighted imaging sequence of magnetic resonance imaging. Immunoglobulin G antibodies against common pathogens, including herpes simplex virus (HSV)‐1, HSV‐2, cytomegalovirus (CMV), Chlamydia pneumoniae (C. pneumoniae), Mycoplasma pneumoniae (M. pneumoniae), Epstein‐Barr virus (EBV), Helicobacter pylori (HP), and Borrelia burgdorferi (B. burgdorferi), were measured by commercial ELISA assays. IB was defined as a composite serologic measure of exposure to these common pathogens.ResultsPatients with and without CMBs were defined as the CMBs group (n = 76) and the non‐CMBs group (n = 81), respectively. IB was significantly different between the CMBs and non‐CMBs groups. After adjusted for other risk factors, the increased IB was independently associated with the presence of CMBs (P = 0.031, OR = 3.00, 95% CI [1.11–8.15]). IB was significantly positively associated with the number of CMBs (Spearman ρ = 0.653, P < 0.001). The levels of serum inflammatory markers were significantly different between the CMBs and non‐CMBs groups and among the categories of IB.InterpretationIB consisting of HSV‐1, HSV‐2, CMV, C. pneumoniae, M. pneumoniae, EBV, HP, and B. burgdorferi was associated with CMBs. All the findings suggested that pathogen infection could be involved in the pathogenesis of CMBs.

Comparison of susceptibility weighted imaging with conventional MRI sequences in multiple sclerosis plaque assessment: A cross-sectional study.

Background:The current study was performed to compare susceptibility-weighted imaging (SWI) with magnetic resonance imaging (MRI) methods of T2-weighted (T2W) and fluid-attenuated inversion recovery (FLAIR) imaging in multiple sclerosis (MS) plaque assessmentMaterials and Methods:This cross-sectional study was conducted among 50 MS patients referred to Shafa Imaging Center, Isfahan, Iran. Patients who fulfilled McDonald criteria and were diagnosed with MS by a professional neurologist at least 1 year before the study initiation were included in the study. Eligible patients underwent brain scans using SWI, T2W imaging, and FLAIR. Plaques’ number and volume were detected separately for each imaging sequence. Moreover, identified lesions in SWI sequence were evaluated in terms of iron deposition and central veinsResults:Totally 50 patients (10 males and 40 females) with a mean age of 28.48 ± 5.25 years were included in the current study. Majority of patients (60%) had a disease duration of >5 years, and mean expanded disability status score was 2.56 ± 1.32. There was no significant difference between different imaging modalities in terms of plaques’ number and volume (P > 0.05). It was also found that there was a high correlation between SWI and conventional imaging techniques of T2W (r = 0.97, 0.91, P < 0.001) and FLAIR (r = 0.99, 0.99, P < 0.001) in the estimation of both the number and volume of plaques (P < 0.001)Conclusion:The results of the present study indicated that SWI and conventional MRI sequences have similar efficiency for plaque assessment in MS patients.

Omparative Analysis of Diagnostic Sensitivity of Magnetic Resonance Susceptibility Sequence with Non Enhanced Computed Tomography and Magnetic Resonance Gradient Sequence in Early Haemorrhagic Transformation of Cerebral Infarction- A Cohort Study

Introduction: Susceptibility Weighted Imaging (SWI) is a Magnetic Resonance Imaging (MRI) sequence aiming to enhance contrast in MR imaging. SWI is considered to be sensitive in detecting even minute amount of haemorrhage, putting in consideration that early detection of haemorrhage inside acute infarction restricts the use of thrombolytic drugs and minimise the development of large haematoma that need to be evacuated surgically thus, improving the prognosis of the patient. Aim: To evaluate and compare the diagnostic sensitivity of MR SWI with Non Enhanced Computed Tomography (NECT) and Magnetic Resonance Gradient Recalled Echo (MR GRE) sequence in detecting the early Haemorrhagic Transformation (HT) of cerebral infarction. Materials and Methods: This was a cohort study conducted from July 2018 to October 2019 on 45 patients referred to the Radiology Department of the institute with imaging findings suggestive of stroke. Apart from the NECT brain conducted on 128 slice machine and routine stroke protocol, MR SWI was also performed. MRI study was performed on 1.5 Tesla MRI scanner with a eight channel Navigator radiofrequency coil. A follow-up CT was done after 48 hours. The images obtained were subjected to radiological analysis and interpretation. Statistical Package for Social Sciences (SPSS) version 22, descriptive analysis was carried out by calculating mean±standard deviation, frequency and proportion. The collected data was compared with each other, using Chi-square test and Fisher's-exact test, correlated using Spearman Correlation test. Results: Total 45 patients (mean age: 56 years, 31 males and 14 females) were included in the study. The diagnostic sensitivity of MR SWI in detecting early HT was high 97.5% compared to 45.0% of NECT and 82.5% of MR GRE. However, the specificity of MR SWI (33.3%) and that of MR GRE (33.33%) were very low as compared to NECT (66.67%), which had a higher specificity in detection of HT. There was a weak positive correlation between surface area of bleed in GRE and surface area of bleed in SWI (Spearman’s RHO correlation 0.324, p-value 0.030). Conclusion: MR SWI had high diagnostic sensitivity in detecting HT earlier than NECT and MR GRE sequence and hence, it could play a crucial role in the treatment of patients. One of the most dreaded complications of cerebral infarction-intracerebral haemorrhage could be prevented and thus, prognosis of the patient improves. Hence, MR SWI sequence should be added to routine stroke protocol, however it cannot replace NECT, since the specificity of NECT is high compared to MR SWI.

Evaluation of subacute subarachnoid haemorrhage detection using a magnetic resonance imaging sequence: Double inversion recovery.

Background and objectivesThe diagnosis of subarachnoid hemorrhage (SAH) especially at the subacute stage is still a challenging issue using the conventional imaging modalities. Here we evaluated the role of double inversion recovery (DIR) sequence of MRI compared with the conventional gradient-recalled echo (GRE)-T2*-W and susceptibility-weighted imaging (SWI) sequences in the diagnosis of subacute SAH.Materials and methodsThis prospective study was conducted on 21 patients with SAH, which were diagnosed using CT scan at the initial step. In the third week after the injury (14-20 days), all patients underwent a brain MRI exam that included T2*-W, SWI, and DIR imaging sequences. All images were independently read by two radiologists, who were blinded to the clinical history of the patients. The presence or absence of SAH was reviewed and assessed in 6 anatomical regions.ResultsOn the DIR images, 20 patients were found to have at least one subarachnoid signal abnormality, while the SWI and T2*-W images identified SAH areas on 17 and 15 patients, respectively. The highest rate of inter-observer consensus by the DIR sequence was found in the interhemispheric fissure and perimesencephalic area (k = 1). Also, a highest rate of inter-observer consensus using SWI was found in the interhemispheric fissure and posterior fossa cistern area (k = 1). A weak agreement was found in frontal-parietal convexity using SWI (k = 0.447), and in posterior fossa cistern by the T2* sequence (k = 0.447).ConclusionIn conclusion, the DIR sequence was more reliable at identifying signal abnormalities in subacute SAH patients than the T2*-W and SWI sequence, and is suggested as a promising imaging technique for detecting hemorrhagic areas without considering the anatomical distribution of SAH.

Analysis of imaging features of age-related cerebral small vessel disease with idiopathic normal pressure hydrocephalus

Objective: To explore the imaging features in age-related cerebral small vessel disease (ArCSVD) with idiopathic normal pressure hydrocephalus (INPH). Methods: Ten cases of age-related cerebral small vessel disease (CSVD) with idiopathic normal pressure hydrocephalus admitted to the Third Affiliated Hospital of Sun Yat-sen University from December 2015 to March 2020 were retrospective analyzed, all patients met the inclusion and exclusion criteria, and completed the head Magnetic resonance angiography plain scan, T2 fluid attenuated inversion recovery and Susceptibility Weighted Imaging sequence. Deep marrow venous signs (DMVs), INPH severity (DESH score), cortical/subcortical and deep microhemorrhages (CMBs) statistics, paraventricular and deep white matter damage (WMH) severity and CSVD imaging burden score were acquired, and correlations of DMVs and DESH scores with CMBs, WMH and Burden scores were evaluated using Spearman correlation analysis. Results: DMVs and DESH scores were significantly and positively correlated (r=0.965 9, P<0.000 1). DMVs and DESH scores were not significantly correlated with cortical/subcortical CMBs and deep CMBs. Likewise, DMVs and DESH scores were not significantly correlated with deep WMH. The WMH score of paraventricular of the 10 cases was 3 points, and the Burden score was 4 points. Conclusion: DMVs may be an indicator of the severity of ArCSVD with INPH, due to the small sample size of the current study, more cases are needed for further verification.

Morphology and signal changes of the lentiform nucleus based on susceptibility weighted imaging in parkinsonism-predominant multiple system atrophy

IntroductionIt remains challenging to make a differential diagnosis between atypical parkinsonism and Parkinson's disease (PD) from routine neuroimaging. This case-control study aimed to quantitatively investigate both morphological and signal intensity changes in susceptibility weighted imaging (SWI) of the lentiform nucleus (LN) for discriminating parkinsonism-predominant multiple system atrophy (MSA-P) from PD. MethodsWe retrospectively enrolled patients with MSA-P, PD, and sex- and age-matched controls between January 2016 and November 2019 at the Movement Disorder Center who underwent 3T MR imaging of brain with SWI sequence. Two specialists at the center reviewed the medical records and made the final diagnosis, and two experienced neuroradiologists performed MRI image analysis based on a defined radiological protocol to conduct the ROI-based morphological measurements of the LN and the signal intensity. ResultsA total of 19 patients with MSA-P, 19 patients with PD and 19 controls were enrolled in this study. We found that patients with MSA-P had significant decreases size in the short line (SL) and the ratio of the SL and the long line (SLLr) and increased value in the signal intensity standard deviation of the LN (SIsd_LN) compared with the patients with PD and with the controls (P < 0.05). Combining these three indexes, this finding had a sensitivity of 94.7% and a specificity of 63.2% to distinguish MSA-P from PD. ConclusionAs compared to PD and control subjects, the SA-P patients are characterized by narrowing morphology and the inhomogeneous signal intensity of the posterior region of LN. The quantitative morphological change is a possible potential marker to differentiate MSA-P from PD on SWI.

Utility of Imaging of Nigrosome-1 on 3T MRI and Its Comparison with 18F-DOPA PET in the Diagnosis of Idiopathic Parkinson Disease and Atypical Parkinsonism.

Loss of nigrosome-1 on 3T and 7T magnetic resonance imaging (MRI) is a recently explored imaging biomarker in the diagnosis of neurodegenerative parkinsonism. This study was undertaken to evaluate the utility of imaging of nigrosome in the diagnosis of neurodegenerative parkinsonism on 3T MRI. An institution-based prospective case-control study was conducted at a tertiary care center in North India. 3T venous blood oxygen level-dependent (VenoBOLD) and high-resolution susceptibility-weighted imaging (SWI) imaging sequences in MRI were performed in 100 patients with parkinsonism (56 with idiopathic Parkinson's disease [IPD], 30 with young onset Parkinson's disease [YOPD], 12 with progressive supranuclear palsy, and 2 patients with multiple system atrophy) and 15 controls. Grading of nigrosome was done in both the sequences. Each patient underwent 18F-DOPA positron emission tomography (PET), detailed neurological examination including Hoen and Yahr (H&Y) staging and Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) scoring. The diagnostic sensitivity and specificity of the detection of loss of nigrosome-1 on VenoBOLD and SWI sequence at 3T MR imaging were 90% and 66.7% and 94% and 80%, respectively. A weak negative correlation was found between the grading of the nigrosome and clinical parameters (H&Y and UPDRS III). There was no correlation between the side of nigrosome loss and clinical asymmetry. However, nigrosome imaging was not able to differentiate between Parkinson's disease and atypical parkinsonism. The loss of nigrosome-1 on 3T MRI on SWI and VenoBOLD sequences may serve as a potential imaging marker in the diagnosis of degenerative parkinsonian syndromes. However, it cannot differentiate between idiopathic Parkinson's disease and atypical parkinsonian syndromes.

A susceptibility-weighted imaging qualitative score of the motor cortex may be a useful tool for distinguishing clinical phenotypes in amyotrophic lateral sclerosis.

To distinguish amyotrophic lateral sclerosis (ALS) and its subtypes from ALS mimics and healthy controls based on the assessment of iron-related hypointensity of the primary motor cortex in susceptibility-weighted imaging (SWI). We enrolled 64 patients who had undergone magnetic resonance imaging studies with clinical suspicions of ALS. The ALS group included 48 patients; the ALS-mimicking disorder group had 16 patients. The ALS group was divided into three subgroups according to the prevalence of upper motor neuron (UMN) or lower motor neuron (LMN) impairment, with 12 subjects in the UMN-predominant ALS group (UMN-ALS), 16 in the LMN-predominant ALS group (LMN-ALS), and 20 with no prevalent impairment (C-ALS). The Motor Cortex Susceptibility (MCS) score was defined according to the hypointensity of the primary motor cortex in the SWI sequence. Its diagnostic accuracy in differentiating groups was evaluated. The MCS was higher in the ALS group than in the healthy control and ALS-mimicking disorder groups (p< 0.001). Among ALS subgroups, the MCS was significantly higher in the UMN-ALS group than in the healthy control (p< 0.001), ALS-mimicking disorder (p= 0.002), and LMN-ALS groups (p= 0.002) and higher in the C-ALS group than in the healthy control group (p= 0.019). An MCS value ≥ 2 showed specificity and a positive predictive value of 100% in the detection of both UMN-ALS and C-ALS patients. The assessment of MCS in the SWI sequence could be a useful tool in supporting diagnosis in patients suspicious for ALS with prevalent signs of UMN impairment or with no prevalence signs of UMN or LMN impairment. • The hypointensity of the primary motor cortex in susceptibility-weighted imaging could support the diagnosis of ALS. • Our new qualitative score called MCS shows high specificity and positive predictive value in differentiating ALS patients with upper motor neuron impairment from patients with ALS-mimicking disorders and healthy controls.

Role of magnetic susceptibility-weighted imaging in characterization of cerebral microbleeds in acute ischemic stroke Egyptian obese patients

ObjectiveThe study was done to investigate the role of susceptibility-weighted imaging (SWI) in characterization of cerebral microbleeds (CMBs) and incidence of CMBs in acute ischemic stroke obese patients.Materials and methodsWe recruited 120 acute ischemic stroke obese patients. All participants or their relatives gave written informed consent. MRI of the brain with SWI sequences was done for all patients.ResultsSWI showed 30% of the patients have CMBs. The total numbers of CMBs were statistically significant higher in small vessel diseases (SVDs) than large vessel diseases (LVDs) (P = 0.008). According to the severity scale, CMBs were more prominent in patients with grade 0 (70%) followed by grade III (25.8%) then grade II (4.2%). BMI was independent risk factors for developing CMBs as shown in simple regression analysis (х2 = 6.008, P = 0.002). SVDs and hypertension were statistically significant independent predictors and had higher odds to exhibit CMBs. Patients with SVDs had 5.3 times higher odds to exhibit CMBs (P = 0.002) while patients with hypertension had 3.9 times higher odds to exhibit CMBs (P = 0.032).ConclusionSWI is a gold standard MR imaging technique in diagnosis and characterization of CMBs with more prevalence especially in obese patients suffering from acute ischemia stroke due to SVDs. Hypertension was an independent risk factor for development of CMBs but IHD, use of antiplatelet medications, increased BMI, and dyslipidemia must be taken into consideration.

Texture analysis in susceptibility-weighted imaging may be useful to differentiate acute from chronic multiple sclerosis lesions.

To evaluate the diagnostic performance of texture analysis (TA) applied on non-contrast-enhanced susceptibility-weighted imaging (SWI) to differentiate acute (enhancing) from chronic (non-enhancing) multiple sclerosis (MS) lesions. We analyzed 175 lesions from 58 patients with relapsing-remitting MS imaged on a 3.0 T MRI scannerand applied TA on T2-w and SWI images to extract texture features. We evaluated the presence or absence of lesion enhancement on T1-w post-contrast images and performed a computational statistical analysis to assess if there was any significant correlation between the texture features and the presence of lesion activity. ROC curves and leave-one-out cross-validation were used to evaluate the performance of individual features and multiparametric models in the identification of active lesions. Multiple TA features obtained from SWI images showed a significantly different distribution in acute and chronic lesions (AUC, 0.617-0.720). Multiparametric predictive models based on logistic ridge regression and partial least squares regression yielded an AUC of 0.778 and 0.808, respectively. Results from T2-w images did not show any significant predictive ability of neither individual features nor multiparametric models. Texture analysis on SWI sequences may be useful to differentiate acute from chronic MS lesions. The good diagnostic performance could help to reduce the need of intravenous contrast agent administration in follow-up MRI studies. • Texture analysis applied on SWI sequences may be useful to differentiate acute from chronic multiple sclerosis lesions • The good diagnostic performance could help to minimize the need of intravenous contrast agent administration in follow-up MRI studies.

An unusual cause of superficial siderosis of central nervous system: A case report of a vestibular schwannoma

Vestibular schwannomas are relatively common benign tumors that account for 7-8% of all intracranial tumors. There is a limited number of cases of subarachnoid hemorrhage associated with vestibular schwannoma in the literature. The incidence of symptomatic tumor bleeding is historically reported less than 1%. Susceptibility-weighted imaging (SWI) is a relatively new Magnetic Resonance Imaging (MRI) sequence that is highly sensitive to compounds which distort the local magnetic field such as blood products and hemorrhage. We herein report the rare MRI findings of a 53-year-old man with unilateral vestibular schwannoma and hearing loss who was followed for 4 years. Initial diagnosis of the vestibular schwannoma was made on prior conventional MRI. We included SWI sequence in routine brain MRI protocol. During follow-up, SWI demonstrated focal superficial siderosis due to recurrent subarachnoid hemorrhage seen as hypointense blooming artifacts on the middle cerebellar peduncle-pons junction adjacent to the mass. We think that including SWI in routine MRI protocol will contribute to the initial diagnosis of acoustic schwannoma and detection of its complications such as subarachnoid hemorrhage and subsequent superficial siderosis.

Susceptibility-weighted imaging and transcranial Doppler ultrasound in patients with cerebral small vessel disease.

Cerebral small vessel disease (SVD) is a common accompaniment to aging. Magnetic resonance imaging (MRI) features of SVD include lacunar infarcts (LI) and white matter hyperintensity (WMH). Brain iron deposition is also a known marker of SVD that is associated with cognitive impairment and can be detected with susceptibility-weighted imaging (SWI) MRI technique. According to recent studies, the pulsation of cerebral blood flow can be one of the main factors of the development of pathological brain changes in elderly patients. The objective of this study was to investigate the relationship between the brain iron deposition, cerebral blood flow pulsation, and cognitive impairment in patients with SVD. For the study, 97 patients with diagnosed SVD were selected. The patients were divided into two groups based on the Montreal Cognitive Assessment (MoCA) test scores. All patients underwent MRI in the SWI sequence. Pulsatility index (PI) and resistivity index (RI) were recorded from the middle cerebral artery bilaterally using transcranial Doppler (TCD). The linear regression model showed that the pulsatility index (PI) and resistivity index (RI) were associated with cognitive impairment and brain iron deposition in basal ganglia. The most significant association was found between left globus pallidus severe hypointensity voxels count and left middle cerebral artery (MCA) RI (p = 0.009). The results of the study provide information that TCD indicators may be associated with brain iron deposition and cognitive decline in patients with SVD. Our findings suggest that both brain iron deposition and cerebral hemodynamics abnormalities may play an important role in the pathophysiological mechanisms of SVD.

Prolonged Migraine Stuttering Aura: Structural, Functional, and Video Neuroimaging Study of an Atypical Migraine Aura. A Case Report

Stuttering is a disorder in the rhythm of speech characterized by an involuntary repetition, prolongation, and cessation of sounds. Neurogenic acquired stuttering is a very rare disorder which could result from different conditions with the involvement of several brain locations. A 16-year-old male presented to our Hospital with headache associated with blurred vision followed by right-sided facial and upper limb tingling, clumsiness of right arm, and a complete inability to formulate language which evolved in the next minutes into an intense speech disorder characterized by persistent stuttering. Urgent brain magnetic resonance imaging showed a prominence of venous vasculature in left hemisphere in susceptibility weighted imaging sequence. A fluorodeoxyglucose-positron emission tomography revealed a bilateral occipital, temporal, and parietal hypometabolism. With the suspicion of migraine aura, analgesic treatment was administered. Symptoms progressively resolved inside 10hours. Five months later he experienced a similar episode. This case report represents a diagnostic challenge and suggests the inclusion of stuttering within the neurological manifestations of higher cortical dysfunction that can be found as a result of migraine aura.

What is New about Magnetic Resonance Imaging of Multiple Sclerosis?

Background: Multiple sclerosis (MS) is a demyelinating disease of the central nervous system. Magnetic resonance imaging (MRI) has an important role in early diagnosis of MS. Patients and Method: Thirty patients with clinically diagnosed to have MS according to McDonald criteria were included and referred to department of radio-diagnosis, Faculty of Medicine, Minia University. Imaging was performed on a 1.5T Philips MR system using double inversion recovery (DIR), fluid attenuated inversion recovery (FLAIR), T2-weighted, T1-weighted and susceptibility-weighted imaging (SWI) sequences with the parameters including field of view (FOV), matrix, slice thickness and voxel size. They were done after the approval of ethical committee of our institution. Data analysis was performed using the SPSS version 20 and p-value as well as comparative study were gained. Results: The detection rate of white matter lesions in T2 was (88%); while for grey matter lesions was (10%). In FLAIR sequence, we found that; the detection rate of white matter lesions was (96%); while for grey matter lesions was (25%). As regarding DIR sequence, the detection rate of white matter lesions was (90%); while for grey matter lesions was (95%).Comparative study between serial MRI sequences (T2,FLAIR and DIR) revealed; significant increase in detected number of grey matter lesions; in DIR-MRI sequence (p &lt; 0.0001). In SWI, a central vein sign was detected in 96 lesions (66 in periventricular lesions and 30 in subcortical lesions). Conclusion: From this study we concluded that new imaging modalities of MRI as regarding DIR and SWI are a valuable MRI sequences in imaging of multiple sclerosis; thus, we recommend adding DIR and SWI sequences in routine MR protocols for MS patients.

Role of SWI in Early Detection of Hemorrhagic Transformation in Acute Cerebral Ischemia

Background: The advent of new magnetic resonance imaging (MRI) techniques has improved acute stroke diagnosis. Susceptibility weighted imaging (SWI) has an important role in the management of cerebro-vascular strokes. Patients and Method: The study was conducted upon 50 patients clinically diagnosed with cerebro-vascular strokes and referred to department of radio-diagnosis, Faculty of Medicine, Minia University. Computed tomography (CT) was done at first then magnetic resonance imaging was performed on a 1.5T Philips MR system using conventional MRI sequences as fluid attenuated inversion recovery (FLAIR), T2-weighted, T1-weighted and advanced sequences as susceptibility-weighted imaging (SWI) with the parameters including slice thickness, voxel size, field of view (FOV) and matrix,. They were done after the approval of ethical committee of our institution. Informed written consents were taken from the patients or their relatives. Results : In our study, we found that 35 patients presented with acute non hemorrhagic infarction even on SWI and 15 patients presented with hemorrhagic infarction noted in SWI. Only ten of those patients with hemorrhagic infarction detected in CT. We found that detection rate of hemorrhage in SWI sequence was (100%). Detection rate of hemorrhage in CT was (33.3%). In SWI as regarding detection of different signs of acute ischemic strokes we found that of hemorrhage was (88%), detection rate of prominent cortical veins in vicinity of infarct was (62%) and detection rate of dark vessel sign was 6%. Comparative studies between them were done revealed that hemorrhage was the most important sign detected at SWI. Conclusion : From this study we concluded that new imaging SWI MRI modality is a valuable MRI sequence in imaging hemorrhagic transformation in ischemic stroke.