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Objective: To identify the risk factors contributing to cerebral microbleeds (CMBs), analyze the correlation between the quantity and distribution of CMBs and overall cognitive performance, including specific cognitive domains in patients, and investigate the underlying mechanisms by which CMBs impact cognitive function. Methods: Patients diagnosed with cerebral small vessel disease were recruited between September 2022 and September 2023. Clinical baseline data were systematically gathered. The Montreal Cognitive Assessment (MoCA) was employed to evaluate patients' cognitive status. CMBs were identified via susceptibility-weighted imaging (SWI), noting their locations and quantities. Patients were categorized into two cohorts: those without CMBs and those with CMBs. This division facilitated the comparison of basic clinical data and laboratory indicators, aiming to elucidate the risk factors associated with CMBs. Within the CMBs cohort, patients were further classified based on the number of CMBs into mild, moderate, and severe groups, and according to CMBs' locations into deep, cortical-subcortical, and mixed groups. Spearman correlation analysis and ANOVA were utilized to compare the total MoCA scores, as well as scores in specific cognitive domains, across these groups. This approach enabled the analysis of the relationship between the quantity and location of CMBs and cognitive impairment. Results: Statistically significant differences were noted between patients with and without cerebral microbleeds (CMBs) regarding gender, age, hypertension, diabetes, history of cerebral infarction, history of alcohol consumption, glycosylated hemoglobin levels, low-density lipoprotein cholesterol, and homocysteine levels (p <.05). Multifactorial logistic regression analysis identified age, hypertension, diabetes, history of alcohol consumption, and elevated homocysteine as independent risk factors for the development of CMBs. Spearman correlation analysis revealed a linear correlation between the presence of CMBs and the total score of the MoCA (r = −.837, p <.001). The group with CMBs demonstrated a significant decline in visuospatial execution function and delayed recall abilities compared to the group without CMBs (p <.05). Specifically, deep CMBs were linked to impairments in visuospatial execution function, naming, attention, computational ability, language, delayed recall, and orientation (p <.05). Cortical-subcortical CMBs affected visuospatial execution function, attention, computational ability, and delayed recall ability(p <.05). Mixed CMBs impacted visuospatial execution function and naming (p <.05). Conclusion: Age, hypertension, diabetes, history of alcohol consumption, and elevated homocysteine levels are key independent risk factors for CMBs. There exists a linear relationship between the severity of CMBs and the extent of cognitive impairment. Patients with CMBs show notable deterioration in visuospatial execution function and delayed recall abilities. Furthermore, the location of CMBs influences various specific cognitive domains. [ABSTRACT FROM AUTHOR]

Background: There is a lack of automated tools for the segmentation and quantification of neuromelanin (NM) and iron in the nigrosome‐1 (N1). Existing tools evaluate the N1 sign, i.e., the presence or absence of the "swallow‐tail" in iron‐sensitive MRI, or globally analyze the MRI signal in an area containing the N1, without providing a volumetric delineation. Purpose: Present an automated method to segment the N1 and quantify differences in N1's NM and iron content between Parkinson's disease (PD) patients and healthy controls (HCs). Study whether N1 degeneration is clinically related to PD and could be used as a biomarker of the disease. Study Type: Prospective. Subjects: Seventy‐one PD (65.3 ± 10.3 years old, 34 female/37 male); 30 HC (62.7 ± 7.8 years old, 17 female/13 male). Field Strength/Sequence: 3 T Anatomical T1‐weighted MPRAGE, NM‐MRI T1‐weighted gradient with magnetization transfer, susceptibility‐weighted imaging (SWI). Assessment: N1 was automatically segmented in SWI images using a multi‐image atlas, populated with healthy N1 structures manually annotated by a neurologist. Relative NM and iron content were quantified and their diagnostic performance assessed and compared with the substantia nigra pars compacta (SNc). The association between image parameters and clinically relevant variables was studied. Statistical Tests: Nonparametric tests were used (Mann–Whitney's U, chi‐square, and Friedman tests) at P = 0.05. Results: N1's relative NM content decreased and relative iron content increased in PD patients compared with HCs (NM‐CRHC = 22.55 ± 1.49; NM‐CRPD = 19.79 ± 1.92; NM‐nVolHC = 2.69 × 10−5 ± 1.02 × 10−5; NM‐nVolPD = 1.18 × 10−5 ± 0.96 × 10−5; Iron‐CRHC = 10.51 ± 2.64; Iron‐CRPD = 19.35 ± 7.88; Iron‐nVolHC = 0.72 × 10−5 ± 0.81 × 10−5; Iron‐nVolPD = 2.82 × 10−5 ± 2.04 × 10−5). Binary logistic regression analyses combining N1 and SNc image parameters yielded a top AUC = 0.955. Significant correlation was found between most N1 parameters and both disease duration (ρNM‐CR = −0.31; ρiron‐CR = 0.43; ρiron‐nVol = 0.46) and the motor status (ρNM‐nVol = −0.27; ρiron‐CR = 0.33; ρiron‐nVol = 0.28), suggesting NM reduction along with iron accumulation in N1 as the disease progresses. Data Conclusion: This method provides a fully automatic N1 segmentation, and the analyses performed reveal that N1 relative NM and iron quantification improves diagnostic performance and suggest a relative NM reduction along with a relative iron accumulation in N1 as the disease progresses. Evidence Level: 1 Technical Efficacy: Stage 1 [ABSTRACT FROM AUTHOR]

Background and Aims: Susceptibility‐weighted imaging (SWI) can help in the diagnosis of thrombus within the vessel in acute ischemic stroke, known as susceptibility vessel sign (SVS), and detection of SVS within the vessel can predict treatment modality and outcome. In this study, the purpose is to correlate the SVS on SWI with different parameters of stroke. Methods: This prospective cross‐sectional study enrolled consecutive stroke patients with vessel occlusion on magnetic resonance angiography (MRA) over 1 year. The relationship between SVS on SWI with risk factors, territory involved, and length of thrombus was correlated with the National Institutes of Health Stroke Scale (NIHSS). Results: A total of 105 patients were enrolled in this study. Sixty‐two percent (66 out of 105) of patients showed SVS on SWI with MRA‐positive occlusion. A positive correlation was observed between SVS on SWI and the risk factor (p = 0.003, chi‐square test), with 86% of patients with heart disease and 47% with hypertension exhibiting SVS. Additionally, a positive correlation was observed between SVS on SWI and territorial occlusion (p = 0.000, chi‐square test). A moderate positive correlation was observed between the NIHSS and thrombus length (p = 0.002, Pearson's correlation coefficient), with a Pearson's coefficient of 0.367. Conclusions: SWI can be useful in identifying the location of the thrombus, and NIHSS can determine the thrombus length in acute stroke. A higher incidence of SVS can be associated with risk factors, and it also depends upon the site of occlusion of the vessel. Key points: Sixty‐two percent of patients showed susceptibility vessel sign (SVS) on susceptibility‐weighted imaging (SWI) with magnetic resonance angiography (MRA)‐positive occlusion, indicating the potential of SWI in assessing stroke severity.Positive correlations were observed between SVS and risk factors (heart disease, hypertension), territorial occlusion, and a moderate correlation between the NIH Stroke Scale (NIHSS) score and thrombus length.SWI is highlighted as a valuable tool due to its superior sensitivity in detecting blood products and vascular anomalies, emphasizing its role in identifying thrombus location and predicting treatment outcomes in acute ischemic stroke. [ABSTRACT FROM AUTHOR]

Abnormal alpha‐synuclein (αSyn) and iron accumulation in the brain play an important role in Parkinson's disease (PD). Herein, we aim to visualize αSyn inclusions and iron deposition in the brains of M83 (A53T) mouse models of PD in vivo. The fluorescent pyrimidoindole derivative THK‐565 probe was characterized by means of recombinant fibrils and brains from 10‐ to 11‐month‐old M83 mice. Concurrent wide‐field fluorescence and volumetric multispectral optoacoustic tomography (vMSOT) imaging were subsequently performed in vivo. Structural and susceptibility weighted imaging (SWI) magnetic resonance imaging (MRI) at 9.4 T as well as scanning transmission x‐ray microscopy (STXM) were performed to characterize the iron deposits in the perfused brains. Immunofluorescence and Prussian blue staining were further performed on brain slices to validate the detection of αSyn inclusions and iron deposition. THK‐565 showed increased fluorescence upon binding to recombinant αSyn fibrils and αSyn inclusions in post‐mortem brain slices from patients with PD and M83 mice. Administration of THK‐565 in M83 mice showed higher cerebral retention at 20 and 40 min post‐intravenous injection by wide‐field fluorescence compared to nontransgenic littermate mice, in congruence with the vMSOT findings. SWI/phase images and Prussian blue indicated the accumulation of iron deposits in the brains of M83 mice, presumably in the Fe3+ form, as evinced by the STXM results. In conclusion, we demonstrated in vivo mapping of αSyn by means of noninvasive epifluorescence and vMSOT imaging and validated the results by targeting the THK‐565 label and SWI/STXM identification of iron deposits in M83 mouse brains ex vivo. [ABSTRACT FROM AUTHOR]

Delirium is a severe postoperative complication associated with poor overall and especially neurocognitive prognosis. Altered brain mineralization is found in neurodegenerative disorders but has not been studied in postoperative delirium and postoperative cognitive decline. We hypothesized that mineralization‐related hypointensity in susceptibility‐weighted magnetic resonance imaging (SWI) is associated with postoperative delirium and cognitive decline. In an exploratory, hypothesis‐generating study, we analysed a subsample of cognitively healthy patients ≥65 years who underwent SWI before (N = 65) and 3 months after surgery (N = 33). We measured relative SWI intensities in the basal ganglia, hippocampus and posterior basal forebrain cholinergic system (pBFCS). A post hoc analysis of two pBFCS subregions (Ch4, Ch4p) was conducted. Patients were screened for delirium until the seventh postoperative day. Cognitive testing was performed before and 3 months after surgery. Fourteen patients developed delirium. After adjustment for age, sex, preoperative cognition and region volume, only pBFCS hypointensity was associated with delirium (regression coefficient [90% CI]: B = −15.3 [−31.6; −0.8]). After adjustments for surgery duration, age, sex and region volume, perioperative change in relative SWI intensities of the pBFCS was associated with cognitive decline 3 months after surgery at a trend level (B = 6.8 [−0.9; 14.1]), which was probably driven by a stronger association in subregion Ch4p (B = 9.3 [2.3; 16.2]). Brain mineralization, particularly in the cerebral cholinergic system, could be a pathomechanism in postoperative delirium and cognitive decline. Evidence from our studies is limited because of the small sample and a SWI dataset unfit for iron quantification, and the analyses presented here should be considered exploratory. [ABSTRACT FROM AUTHOR]

Purpose: In this review, the pathophysiology, clinical manifestations, and radiological findings of sporadic CAA will be detailed. Material and Methods: Cerebral amyloid angiopathy (CAA), the second most common cause of spontaneous acute intracerebral hemorrhage after hypertension in the elderly population is characterized by brain parenchymal damage secondary to hemorrhage and ischemia caused by the accumulation of Aβ protein in the walls of small arteries and arterioles. Advanced age is the most significant risk factor for CAA. While the definitive diagnosis requires histopathological examination through autopsy/biopsy, the probable or possible diagnosis of CAA is based on clinical features as well as characteristic neuroimaging findings. Results: With the increasing elderly population and the growing prevalence of succesibility-weighted magnetic resonance imaging sequences in routine, it becomes imperative to have a thorough understanding of the imaging spectrum associated with CAA. Early diagnosis is extremely critical in patients with CAA who have not yet developed intracranial hemorrhage. Furthermore, patients with CAA may present clinically transient focal neurological episodes or cognitive impairment, which can be mistaken for transient ischemic attacks caused by convexity subarachnoid hemorrhage. Conclusion: Additionally, before initiating newly introduced anti-amyloid monoclonal antibody drugs in Alzheimer's disease, it is necessary to exclude signs of CAA. Moreover, the anticipated side effects of these drugs often manifest imaging abnormalities resembling inflammation or bleeding associated with CAA, necessitating familiarity with the imaging findings of CAA. [ABSTRACT FROM AUTHOR]

ObjectiveTo explore the relationship between the deep medullary vein (DMV) score and atrophy in patients with cerebral small vessel disease (CSVD).MethodsImaging and clinical data from 125 patients with CSVD from January to December 2022 were reviewed. Normalized gray matter volume (GM_N) was calculated by dividing the gray matter volume by the whole brain volume. DMV scoring is conducted using susceptibility-weighted magnetic resonance imaging, wherein the DMV area is partitioned into six distinct regions: bilateral frontal, parietal, and occipital regions. Each region undergoes assessment based on the clarity and consistency of DMV visibility. Subsequently, the scores from these six regions are summed, resulting in a score ranging from 0 to 18 points.ResultsDMV score was associated with GM_N (r = −0.376, p

Abstract Background and Aims Susceptibility‐weighted imaging (SWI) can help in the diagnosis of thrombus within the vessel in acute ischemic stroke, known as susceptibility vessel sign (SVS), and detection of SVS within the vessel can predict treatment modality and outcome. In this study, the purpose is to correlate the SVS on SWI with different parameters of stroke. Methods This prospective cross‐sectional study enrolled consecutive stroke patients with vessel occlusion on magnetic resonance angiography (MRA) over 1 year. The relationship between SVS on SWI with risk factors, territory involved, and length of thrombus was correlated with the National Institutes of Health Stroke Scale (NIHSS). Results A total of 105 patients were enrolled in this study. Sixty‐two percent (66 out of 105) of patients showed SVS on SWI with MRA‐positive occlusion. A positive correlation was observed between SVS on SWI and the risk factor (p = 0.003, chi‐square test), with 86% of patients with heart disease and 47% with hypertension exhibiting SVS. Additionally, a positive correlation was observed between SVS on SWI and territorial occlusion (p = 0.000, chi‐square test). A moderate positive correlation was observed between the NIHSS and thrombus length (p = 0.002, Pearson's correlation coefficient), with a Pearson's coefficient of 0.367. Conclusions SWI can be useful in identifying the location of the thrombus, and NIHSS can determine the thrombus length in acute stroke. A higher incidence of SVS can be associated with risk factors, and it also depends upon the site of occlusion of the vessel.

Purpose To investigate the value of susceptibility weighted imaging (SWI) for assessing the hyperacute outcome of ablation of uterine fibroids immediately after magnetic resonance-guided focused ultrasound (MRgFUS) treatment.Methods This retrospective imaging study included patients who underwent SWI and contrast-enhanced (CE) MR within 15 min of MRgFUS ablation for uterine fibroids. Two readers independently assessed the SWI features of ablative lesions and their association with the non-perfused volume (NPV) ratio. The intraclass correlation coefficient (ICC) and diagnostic value of SWI findings were calculated.Results A total of 27 uterine fibroids from 21 participants (mean age 40.1 ± 7.2 years) were analyzed. 51.9% (14/27) leiomyomas had NPV ratio ≥90%. In post-ablation SWI images, the interobserver ICC for the relative signal intensity and hypointense peripheral rim were 0.613 and 0.843, respectively (both p .05). When using the complete hypointense peripheral rim as a diagnostic criterion to identify NPV ratio ≥ 90%, readers 1 and 2 showed diagnostic sensitivity, specificity, and accuracy of 85.7%, 76.9%, 81.5%, and 78.6%, 76.9%, 77.8%, respectively.Conclusion Identifying a complete hypointense peripheral rim on SWI may be a potential imaging marker for assessing the hyperacute outcome of uterine fibroids ablation by MRgFUS, specifically in determining whether the NPV ratio is ≥90%.

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]

血管性帕金森综合征（vascular parkinsonism，VP）是临床上常见的继发性帕金森综合征，目前VP临床诊断和鉴别诊断的准确率较低，影响其临床治疗和预后。在临床实践中，影像学常用于VP的诊断。近年来多模态MRI和分子影像成像及分析技术等影像学技术的进展为提高VP的诊断和鉴别诊断准确率提供了客观手段。本文就前沿影像学技术在VP与原发性帕金森病以及其他非典型帕金森综合征鉴别诊断领域的研究进展进行综述，以期为VP的诊断和鉴别诊断提供新的思路。 Abstract: Vascular parkinsonism is a common secondary parkinsonism. At present, the accuracy of diagnosis and differential diagnosis of vascular parkinsonism is low, which affects its treatment and prognosis. Imaging is commonly used in clinical practice to diagnose vascular parkinsonism. In recent years, the advance of multimodal MRI and molecular imaging and analysis technology has provided objective methods to improve the accuracy of diagnosis and differential diagnosis of vascular parkinsonism. This paper reviews the latest progress of various cutting-edge imaging techniques in the differential diagnosis of vascular parkinsonism from idiopathic Parkinson’s disease and other atypical parkinsonisms, hoping to provide new ideas for the diagnosis and differential diagnosis of vascular parkinsonism.

Abstract Purpose This study compares the observation efficiency of brain gray matter nuclei of patients with early-stage Parkinson’s disease among various Magnetic Resonance Imaging techniques, which include susceptibility weighted imaging (SWI), quantitative susceptibility imaging (QSM), diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI). Based on the findings, this study suggests an efficient combination of scanning techniques for brain gray matter nuclei observation, aiming to provide an opportunity to advance the understanding of clinical diagnosis of early-stage Parkinson’s disease. Methods Forty examinees, including twenty patients who were clinically diagnosed with early Parkinson’s disease with a course of 0.5-6 years (PD group) and twenty healthy controls (HC group), underwent head MRI examination. Philips 3.0T (tesla) MR machine was used to measure the imaging indexes of gray matter nuclei in patients with early Parkinson’s disease. SWI, QSM, DTI and DKI were used for diagnosis. SPSS (Statistical Product and Service Solutions) 21.0 was used for data analysis. Results When SWI was used, fifteen PD patients and six healthy volunteers were diagnosed correctly. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic coincidence rate about the diagnosis of nigrosome-1 on imaging were 75.0%, 30.0%, 51.7%, 54.5% and 52.5% respectively. By contrast, when QSM was used, 19 PD patients and 11 healthy volunteers were diagnosed correctly. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic coincidence rate about the diagnosis of Nigrosome-one on imaging were 95.0%, 55.0%, 67.9%, 91.7% and 75.0% respectively. The mean kurtosis (MK) value within both the substantia nigra and thalamus, together with the mean diffusivity (MD) within both the substantia nigra and the head of caudate nucleus in PD group was greater than that of HC group. The susceptibility values within the substantia nigra, red nucleus, head of caudate nucleus and putamen of PD group was greater than that of HC group. The MD value in substantia nigra reveals the optimal diagnostic efficiency to distinguish the HC group and the PD group, followed by the MK value in substantia nigra. Specifically, the maximum area under ROC curve (AUC) of the MD value was 0.823, the sensitivity 70.0%, the specificity 85.0%, and the diagnostic threshold 0.414. The area under ROC curve (AUC) of the MK value was 0.695, the sensitivity 95.0%, the specificity 50.0%, and the diagnostic threshold was 0.667. Both of them were statistically significant. Conclusions In the early diagnosis of Parkinson’s disease, QSM is more efficient than SWI in observing nigrosome-1 in substantia nigra. In the early diagnosis of Parkinson’s disease, MD and MK values of substantia nigra in DKI parameters have higher diagnostic efficiency. The combined scanning of DKI and QSM has the highest diagnostic efficiency and provides imaging basis for clinical diagnosis of early Parkinson’s disease.

Key Clinical Message: If you suspect cerebral fat embolism (CFE) of the diagnosis for the patients who present with impaired consciousness and hypoxia following a fracture, susceptibility‐weighted imaging should be included of head MRI imaging. We report a case of cerebral fat embolism (CFE) that could be identified only by susceptibility‐weighted imaging (SWI). Collection and analysis of previous case reports of CFE revealed utilization of SWI in less than one third of suspected cases, despite its known diagnostic ability for CFE. [ABSTRACT FROM AUTHOR]

Vascular parkinsonism is a common secondary parkinsonism. At present, the accuracy of diagnosis and differential diagnosis of vascular parkinsonism is low, which affects its treatment and prognosis. Imaging is commonly used in clinical practice to diagnose vascular parkinsonism. In recent years, the advance of multimodal MRI and molecular imaging and analysis technology has provided objective methods to improve the accuracy of diagnosis and differential diagnosis of vascular parkinsonism. This paper reviews the latest progress of various cutting-edge imaging techniques in the differential diagnosis of vascular parkinsonism from idiopathic Parkinson's disease and other atypical parkinsonisms, hoping to provide new ideas for the diagnosis and differential diagnosis of vascular parkinsonism. [ABSTRACT FROM AUTHOR]

Background and purpose: To investigate Susceptibility Weighted Imaging (SWI) signal changes in the draining vein of deep-seated arterio-venous malformations (AVMs) following stereotactic radiosurgery (SRS). Methods and Materials: This is a retrospective study of 32 patients with deep-seated AVMs who were treated with SRS. Pre-SRS treatment and post-SRS treatment MRI were performed at 6, 12, and 24-month intervals. Deep-seated AVMs were classified based on their anatomical location and venous drainage pattern. AVM nidal volume (cm3) was estimated using the ABC/2 method. AV shunting of the AVM draining veins were graded according to its SWI signal intensity: hyperintense (grade III), mixed signal intensity (grade II), hypointense (grade I) and absent (grade 0). Conventional time-of-flight (TOF)-MRA and contrast enhanced (CE)-MRA sequences were performed to document the patency of the vein. Results: Pre-SRS treatment AVM draining veins were either grade III 18/32 (56%) or grade II 14/32 (44%). Using mixed effects analysis, we demonstrate that each month following the SRS treatment nidal volumes decreased at the rate of 0.51 cm3/per month (CI −0.61 to (−0.40)) p =.00. Following the treatment, there was a clinically significant relationship between the signal and nidal volume: signal 0 corresponded with average nidal volume of 1.81 cm3 (CI 1.40–2.21), signal 1 with nidal volume of 2.06 cm3 (CI 1.69–2.44), signal 2 with nidal volume 2.73 cm3 (CI 2.35–3.11) and signal 3 with nidal volume 3.13 cm3 (CI 2.70–3.56) p =.00. Conclusion: Post-SRS AVM draining veins shows a stepwise regression of the SWI signal grades which can be reliably used as a surrogate to monitor the reduction of AV shunting. [ABSTRACT FROM AUTHOR]

Abstract Background Kernicterus in the acute phase is difficult to diagnose. It depends on a high signal on T1 at the globus pallidum and subthalamic nucleus level. Unfortunately, these areas also show a relatively high signal on T1 in neonates as an expression of early myelination. Therefore, a less myelin-dependent sequence, like SWI, may be more sensitive to detecting damage in the globus pallidum area. Case presentation A term baby developed jaundice on day three following an uncomplicated pregnancy and delivery. Total bilirubin peaked at 542 μmol/L on day four. Phototherapy was started, and an exchange transfusion was performed. ABR showed absent responses on day 10. MRI on day eight demonstrated abnormal high signal globus pallidus on T1w, isointense on T2w, without diffusion restriction, and high signal on SWI at globus pallidal and subthalamus level and phase image at globus pallidal level. These findings were consistent with the challenging diagnosis of kernicterus. On follow-up, the infant presented with sensorineural hearing loss and had a work-up for cochlear implant surgery. At 3 months of age, the follow-up MR shows normalization of the T1 and SWI signals and a high signal on T2. Conclusions SWI seems more sensitive to injury than the T1w and lacks the disadvantage of the T1w sequence, where early myelin confers a high signal.

Key Clinical Message If you suspect cerebral fat embolism (CFE) of the diagnosis for the patients who present with impaired consciousness and hypoxia following a fracture, susceptibility‐weighted imaging should be included of head MRI imaging. Abstract We report a case of cerebral fat embolism (CFE) that could be identified only by susceptibility‐weighted imaging (SWI). Collection and analysis of previous case reports of CFE revealed utilization of SWI in less than one third of suspected cases, despite its known diagnostic ability for CFE.

Purpose: This study compares the observation efficiency of brain gray matter nuclei of patients with early-stage Parkinson's disease among various Magnetic Resonance Imaging techniques, which include susceptibility weighted imaging (SWI), quantitative susceptibility imaging (QSM), diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI). Based on the findings, this study suggests an efficient combination of scanning techniques for brain gray matter nuclei observation, aiming to provide an opportunity to advance the understanding of clinical diagnosis of early-stage Parkinson's disease. Methods: Forty examinees, including twenty patients who were clinically diagnosed with early Parkinson's disease with a course of 0.5-6 years (PD group) and twenty healthy controls (HC group), underwent head MRI examination. Philips 3.0T (tesla) MR machine was used to measure the imaging indexes of gray matter nuclei in patients with early Parkinson's disease. SWI, QSM, DTI and DKI were used for diagnosis. SPSS (Statistical Product and Service Solutions) 21.0 was used for data analysis. Results: When SWI was used, fifteen PD patients and six healthy volunteers were diagnosed correctly. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic coincidence rate about the diagnosis of nigrosome-1 on imaging were 75.0%, 30.0%, 51.7%, 54.5% and 52.5% respectively. By contrast, when QSM was used, 19 PD patients and 11 healthy volunteers were diagnosed correctly. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic coincidence rate about the diagnosis of Nigrosome-one on imaging were 95.0%, 55.0%, 67.9%, 91.7% and 75.0% respectively. The mean kurtosis (MK) value within both the substantia nigra and thalamus, together with the mean diffusivity (MD) within both the substantia nigra and the head of caudate nucleus in PD group was greater than that of HC group. The susceptibility values within the substantia nigra, red nucleus, head of caudate nucleus and putamen of PD group was greater than that of HC group. The MD value in substantia nigra reveals the optimal diagnostic efficiency to distinguish the HC group and the PD group, followed by the MK value in substantia nigra. Specifically, the maximum area under ROC curve (AUC) of the MD value was 0.823, the sensitivity 70.0%, the specificity 85.0%, and the diagnostic threshold 0.414. The area under ROC curve (AUC) of the MK value was 0.695, the sensitivity 95.0%, the specificity 50.0%, and the diagnostic threshold was 0.667. Both of them were statistically significant. Conclusions: In the early diagnosis of Parkinson's disease, QSM is more efficient than SWI in observing nigrosome-1 in substantia nigra. In the early diagnosis of Parkinson's disease, MD and MK values of substantia nigra in DKI parameters have higher diagnostic efficiency. The combined scanning of DKI and QSM has the highest diagnostic efficiency and provides imaging basis for clinical diagnosis of early Parkinson's disease. [ABSTRACT FROM AUTHOR]

Purpose: To describe the role of SWI compared with other MR imaging sequences and CT in diagnosis of cerebral gnathostomiasis. Materials and methods: CTs and MRIs of patients with cerebral gnathostomiasis were retrospectively reviewed. The types of intracranial hemorrhage, including intraparenchymal hemorrhage (IPH), subdural hemorrhage (SDH), subarachnoid hemorrhage (SAH), and their locations were recorded. Results: Four patients proven as cerebral gnathostomiasis were included. Intracranial hemorrhage was detected in all patients. There was IPH in all patients, SAH in 2 patients, and SDH in 2 patients. All patients (4/4) revealed hemorrhagic tracts which were very conspicuously seen on SWI. Other imaging sequences could also reveal hemorrhagic tracts in 3 patients (3/4) but are less conspicuously seen than SWI. None of the CT brains could detect hemorrhagic tracts. Conclusions: Intracranial hemorrhage associated with hemorrhagic tract, best demonstrated by SWI, is the key imaging characteristic in diagnosis of cerebral gnathostomiasis. [ABSTRACT FROM AUTHOR]

The objective of this study is to assess the effectiveness of a stroke clinic in stroke prevention and progression of cerebral microbleeds (CMB). We conducted a retrospective observational study of patients who visited a stroke clinic between January 2011 and March 2017. Susceptibility-weighted imaging (SWI) MRI studies were obtained at baseline and follow-up visits to identify new infarctions and CMB progression. Patients with CMB who also underwent brain computed tomography (CT) imaging were identified and their cerebral arterial calcification was quantified to evaluate the relationship between the extent of intracranial calcification and CMB burden. A total of 64 stroke patients (mean age 73.1 ± 11.0, 47% males) had CMB on baseline and follow-up MRI studies. During a mean follow-up period of 22.6 months, four strokes occurred (4/64, 6%; 3 ischemic, 1 hemorrhagic), producing mild neurological deficit. Progression of CMB was observed in 54% of patients with two MRIs and was significantly associated with length of follow-up. Subjects with intracranial calcification score > 300 cm3 had higher CMB count than those with scores

The objective of this study is to assess the effectiveness of a stroke clinic in stroke prevention and progression of cerebral microbleeds (CMB). We conducted a retrospective observational study of patients who visited a stroke clinic between January 2011 and March 2017. Susceptibility-weighted imaging (SWI) MRI studies were obtained at baseline and follow-up visits to identify new infarctions and CMB progression. Patients with CMB who also underwent brain computed tomography (CT) imaging were identified and their cerebral arterial calcification was quantified to evaluate the relationship between the extent of intracranial calcification and CMB burden. A total of 64 stroke patients (mean age 73.1 ± 11.0, 47% males) had CMB on baseline and follow-up MRI studies. During a mean follow-up period of 22.6 months, four strokes occurred (4/64, 6%; 3 ischemic, 1 hemorrhagic), producing mild neurological deficit. Progression of CMB was observed in 54% of patients with two MRIs and was significantly associated with length of follow-up. Subjects with intracranial calcification score > 300 cm3 had higher CMB count than those with scores

目的 旨在统计SWI相位图病灶本身信号强度（直接征象）鉴别单纯出血或钙化发生错判的概率，并通过logistic回归分析确定错判的独立影像学危险因素，为影像及临床医师鉴别诊断提供依据。 方法 回顾性分析2016-2019年首都医科大学附属北京天坛医院单纯出血或钙化病例，连续性入组。将SWI图像进行标准化，即将左手图变成右手图。含有多个病灶者，所有病变逐个评估。两名观察者直观定性评估SWI相位图数据：低、高信号或无法判断（混杂或等信号），预测病变为出血或钙化。与CT诊断“金标准”进行对比，预判结果与CT结果不一致者认定为失败组，一致者为成功组。评估的临床及影像学影响因素包括年龄、性别、病灶直径、平均CT值、T1WI和T2WI信号、SWI相位图病灶本身信号强度（直接征象）、左右手图、病灶位置、侧别、单多发及病灶性质。采用logistic回归分析SWI相位图病灶本身信号强度法鉴别失败的影响因素。 结果 共纳入受试者41例，病灶339个，钙化及出血病灶分别为157个及182个。失败组105个病灶，成功组234个病灶。通过SWI相位图病灶本身信号强度（直接征象）错判率为30.97%。多因素logistic回归分析显示，SWI相位图等或混杂信号（OR 97.263，95%CI 28.746～329.096，P4 mm（OR 2.437，95%CI 1.168～5.084，P=0.018）是导致SWI相位图病灶本身信号强度（直接征象）错判的独立危险因素。 结论 SWI相位图病灶高或混杂信号者、T2WI低或混杂信号者、CT值91～300 Hu者及病灶直径>4 mm者采用SWI相位图病灶本身信号强度（直接征象）方法鉴别单纯出血及钙化错误风险高，对临床及影像学诊断有一定指导作用。 Objective To investigate the influencing factors for false differentiating simple hemorrhage from calcification by cerebral lesion signal intensity on SWI phase image. Methods This retrospective analysis enrolled the consecutive patients with simple calcifications and/or microhemorrhage on head SWI phase image at Beijing Tiantan Hospital, Capital Medical University between 2016 and 2019. Follow-up CT scan was taken as the gold standard. The evaluation standard on right handed SWI phase image: low and high intensity signal sign for hemorrhage and calcification, respectively. The clinical and imaging parameters included gender, age, lesion side, location, diameter, single or multiple lesions, lesion nature, CT value, T1WI and T2WI signal, lesion signal intensity on SWI phase image, left- or right-handed MR image. Multivariate logistic regression analysis was used to analyze the influencing factors for false differentiating the lesions. Results A total of 339 lesions from 41 cases were analyzed, including 157 hemorrhage lesions and 182 calcification lesions. 234 lesions were correctly diagnosed and 105 lesions were incorrectly diagnosed, and the false diagnosis rate was 30.97% by the signal intensity on SWI phase image. Multivariate logistic regression analysis showed that equal or mixed signal intensity (OR 97.263, 95%CI 28.746-329.096, P

目的 探讨缺血性卒中（acute ischemic stroke，AIS）急性期头颅MRI SWI序列上不对称突出静脉征（asymmetrical prominent veins sign，APVS）的发生率及其影响因素。 方法 前瞻性连续收集2021年7月-2022年3月在青岛大学附属烟台毓璜顶医院就诊的AIS患者。所有患者均在发病72 h内完成多模式头颅MRI检查，包括DWI、SWI和MRA序列，根据SWI上是否出现APVS，将患者分为APVS阳性组和APVS阴性组，收集患者年龄、性别、血管危险因素、入院时NIHSS、入院时平均动脉压、发病至MRI检查时间、颅内血管狭窄情况、梗死部位、TOAST分型及90 d不良预后（mRS＞1分）等资料，采用单因素分析和多因素logistic回归分析APVS的影响因素。 结果 共入组80例患者，其中28例（35%）SWI序列上出现APVS。单因素分析显示，APVS阳性组患者的入院时NHISS[8（4～11）分 vs. 2（1～6）分，P＜0.001]、颅内血管重度狭窄或闭塞比例（57.1% vs. 3.8%，P＜0.001）、前循环梗死比例（92.9% vs. 65.4%，P=0.007）以及90 d不良预后比例（71.4% vs. 30.8%，P＜0.001）均高于APVS阴性组。多因素logistic回归分析显示，与APVS独立相关的因素为前循环梗死（OR 7.665，95%CI 1.089～53.959，P=0.041）、颅内血管重度狭窄或闭塞（OR 20.928，95%CI 3.420～128.056，P=0.001）。 结论 前循环梗死、颅内血管重度狭窄或闭塞的AIS患者SWI序列上更易出现APVS。 Abstract: Objective To investigate the related factors leading to asymmetrical prominent veins sign (APVS) on SWI in patients with acute ischemic stroke (AIS). Methods This prospective study enrolled the consecutive patients with AIS admitted to the Affiliated Yantai Yuhuangding Hospital of Qingdao University between July 2021 and March 2022. All patients completed multimodal MRI within 72 hours of symptoms onset, including DWI, SWI and MRA sequences. Patients were divided into APVS positive and negative groups according to having APVS on SWI or not. The baseline clinical data and 90-day poor prognosis (mRS>1) were collected. Multivariate logistic regression analysis was used to determine the factors affecting the presence of APVS. Results A total of 80 patients were enrolled, with APVS on SWI occurring in 28 patients (35%). Univariate analysis showed that the NIHSS score [8 (4-11) vs. 2 (10-6), P

目的 比较SWI相位图病灶本身信号强度（传统直观）法与病灶周围征象即极晕（间接）法对单纯出血或单纯钙化的诊断效能。 方法 本研究纳入以随访CT为“金标准”（单次病灶CT或复查CT值变化）的单纯钙化灶和单纯出血灶。针对每个病灶分别采用SWI相位图病灶本身信号强度（传统直观）法和病灶周围极晕（间接）法评估。SWI相位图全部转换为右手图后再进行评估。SWI相位图病灶本身信号强度（传统直观）法评估标准：病灶本身呈低、高信号分别代表出血及钙化。病灶周围极晕（间接）法评估标准：低信号两极征或高信号反晕征，认定病变为出血；高信号两极征或低信号反晕征，认定病变为钙化。用科恩Kappa值评估两名观察者评判相位图病灶本身信号强度、病灶周围极晕结果的一致性。采用阴性预测值、阳性预测值、敏感度及特异度评估上述两种方法鉴别钙化的诊断效能。 结果 共纳入224个病灶（共36例患者）。其中出血灶123个病灶（8例患者），钙化灶101个病灶（28例患者）。两名观察者病灶本身信号强度法（K=0.768）及病灶周围极晕法（K=0.876）分析SWI相位图的结果一致性较好。SWI相位图病灶本身信号强度法鉴别钙化的阳性预测值、阴性预测值、敏感度及特异度分别为66.7%、70.2%、61.4%、74.8%。病灶周围极晕法鉴别钙化的阳性预测值、阴性预测值、敏感度及特异度分别为99.0%、97.6%、97.0%、99.2%。 结论 SWI相位图病灶周围极晕法具有潜在的临床实用价值，有可能成为一种简便易行的MR鉴别单纯出血或钙化的方法。 Abstract: Objective To compare the diagnostic value of traditional method of signal intensity of foci and indirect signs (reversed halo sign and bipolar sign) on SWI phase image in differentiating simple calcification from hemorrhage. Methods The included simple calcification and simple hemorrhage were confirmed by follow-up CT scan. All the lesions were evaluated by traditional method and indirect polar-halo method. The evaluation standard of traditional method as follows: low and high intensity sign representing hemorrhage and calcification, respectively. The evaluation standard of indirect method as follows: low signal intensity bipolar sign or high signal intensity reversed halo sign representing hemorrhage, and high signal intensity bipolar sign or low signal intensity reversed halo sign representing calcification. The Kappa value was calculated to evaluate the consistency of lesion signal intensity and peri-lesion polar-halo sign results between the two observers. Positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity were calculated to evaluate the diagnosis value of SWI direct and indirect characteristics in differentiating simple calcification and hemorrhage. Results A total of 224 lesions (36 patients) were included, with 101 simple calcifications (28 patients) and 123 simple hemorrhagic lesions (8 cases). The consistency coefficient of the two observers on traditional method and indirect polar-halo method was 0.768 and 0.876, respectively. The PPV, NPV, sensitivity and specificity of traditional method in identifying calcification were 66.7%, 70.2%, 61.4% and 74.8%, respectively. The PPV, NPV, sensitivity and specificity of polar-halo method in identifying calcification were 99.0%, 97.6%, 97.0% and 99.2%, respectively. Conclusions The indirect polar-halo sign on SWI phase image has a higher diagnostic accuracy, which may be a more reliable way to differentiate simple hemorrhage from simple calcification.

Background: Kernicterus in the acute phase is difficult to diagnose. It depends on a high signal on T1 at the globus pallidum and subthalamic nucleus level. Unfortunately, these areas also show a relatively high signal on T1 in neonates as an expression of early myelination. Therefore, a less myelin-dependent sequence, like SWI, may be more sensitive to detecting damage in the globus pallidum area. Case presentation: A term baby developed jaundice on day three following an uncomplicated pregnancy and delivery. Total bilirubin peaked at 542 μmol/L on day four. Phototherapy was started, and an exchange transfusion was performed. ABR showed absent responses on day 10. MRI on day eight demonstrated abnormal high signal globus pallidus on T1w, isointense on T2w, without diffusion restriction, and high signal on SWI at globus pallidal and subthalamus level and phase image at globus pallidal level. These findings were consistent with the challenging diagnosis of kernicterus. On follow-up, the infant presented with sensorineural hearing loss and had a work-up for cochlear implant surgery. At 3 months of age, the follow-up MR shows normalization of the T1 and SWI signals and a high signal on T2. Conclusions: SWI seems more sensitive to injury than the T1w and lacks the disadvantage of the T1w sequence, where early myelin confers a high signal. [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 To assess whether internal cerebral vein （ICV） asymmetry on susceptibility weighted imaging （SWI） of MRI is associated with malignant brain edema （MBE） and long-term poor outcome in acute ischemic stroke （AIS） patients with large vessel occlusion （LVO）; proximal occlusion of internal carotid artery or M1 segment of middle cerebral artery. Methods Clinical and image data of AIS patients with LVO were collected. According to the signal of ICV on SWI, all patients were divided into the asymmetric and non-asymmetric ICV groups. The incidence of MBE and long-term poor outcome were statistically compared between two groups. Results Thirty-two AIS patients with LVO, including 19 in the asymmetric and 13 in the non-asymmetric ICV groups, were recruited in this study. The median NIHSS score was 17. Patients with asymmetric ICV had a significantly higher incidence of MBE （76.9% vs. 5.9%,P < 0.001）, lower proportion of 3-month good outcome （23.1% vs. 70.6%, P = 0.025） and higher 3-month mortality rate （46.2% vs. 0%,P = 0.003） compared with their counterparts with non-asymmetric ICV. Binary logistic analysis showed that asymmetric ICV was associated with the incidence of MBE in AIS patients with LVO （OR = 43.333,95%CI： 3.897-481.820, P = 0.020）. The progression of MBE was correlated with 3-month poor outcome in AIS patients with LVO （OR = 0.330,95%CI： 0.002-0.653,P = 0.025）. Conclusions For AIS patients with LVO, asymmetric ICV on SWI sequence of MRI is probably associated with the risk of MBE. Moreover, the progression of MBE may be correlated with 3-month poor outcome.

Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating disease of the central nervous system whose clinical manifestations and diagnostic criteria are non-specific and absence of golden criteria when diagnosing. Magnetic resonance imaging (MRI) can not only observe the focal lesions of demyelination, but also evaluate microstructural damages and iron deposition in the white/gray matter in MS patients by applying various developing sequences. MRIs play an irreplaceable role in revealing pathological evolution, prognosis and monitoring after treatment of MS patients. This paper reviewed the clinical value and application of MRIs for the MS patients in recent years.

Background: The Gd-SWI sequence is a new important magnetic resonance imaging sequence that has been applied currently due to its ability to optimize the recognition of active plaques of MS and has a higher accurate performance than gadolinium T1WI that is currently used in clinical practice. The aim of this study is comparing the performance of the Gd-SWI sequence with the performance of other used sequences in clinical practice in detection of blood brain barrier (BBB) dysfunctions in MS plaques. Methods: In this retrospective study, Twenty four patients were involved (16 females and 8males, their age ranging from 20-42 years with the mean age 26.33 years), they were divided into two groups: 8 active cases and 22 inactive cases clinically and radiologically proven MS cases for MRI diagnosis and follow up. Results: Two thirds of the studied group (66.7 %) had inactive lesions and one third (33.3 %) had active ones with (12.5 %) of both active and inactive lesions were progressive. There was higher ability of post-contrast SWI to demonstrate active plaques than post-contrast TIWI and there was highly statistically significance and good agreement (kappa=0.71) with 89.5% percent of agreement between post contrast enhanced lesions by SWI and T1 and statistically highly significant difference (p<0.001). Conclusions: Gadolinium -- SWI technique improved detection accuracy of MS- contrast-enhanced plaques better than Gd-T1 SE, including their locations and morphologies. [ABSTRACT FROM AUTHOR]

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Background: Haemorrhagic demyelinating lesions are rare, and little is known about the demyelinating diseases with which they are associated, or how lesional haemorrhage affects treatment and outcomes. Objective: To examine the clinical characteristics and outcomes of patients with demyelinating lesions and magnetic resonance imaging (MRI) evidence of haemorrhage seen at the Mayo clinic between 1990 and 2018. Methods: The Mayo Clinic's medical-record diagnostic-linkage system was used to identify patients with CNS demyelinating disease and parenchymal haemorrhage on brain MRI cross-referenced against a database of patients with pathologically confirmed CNS demyelinating disease. The clinical characteristics, diagnosis, MRI findings, brain histopathology, and outcomes of these patients were reviewed. Results: Ten patients with haemorrhagic demyelination were identified, including three patients who underwent a brain biopsy. The main findings were that haemorrhagic demyelinating lesions most often occur in atypical forms of demyelination, especially acute haemorrhagic leukoencephalitis (AHL, or Weston–Hurst disease) and tumefactive demyelination, and rarely in multiple sclerosis. A spectrum of outcomes was observed for these patients ranging from complete remission through to high level disability. Conclusion: Lesional haemorrhage is uncommon in demyelinating disease where it is most closely associated with AHL. Bleeding within a demyelinating lesion does not always herald a poor prognosis. [ABSTRACT FROM AUTHOR]

To investigate the feasibility of susceptibility weighted imaging (SWI) in detecting tumour boundaries in metastatic liver disease (MLD) without contrast agent, and whether SWI can provide pathophysiologic information for preoperative evaluation. Thirty patients with MLD underwent tumour resection. All patients underwent conventional MRI (T1-weighted and T2-weighted imaging), contrast-enhanced (CE) MRI and multibreath-hold 2D SWI. The conspicuity of the tumour boundary was assessed using a 4-grade scale. The detection rate of tumour boundaries and areas were reviewed and measured. The longest dimension was used to estimate the tumour size from the MR image. The conspicuity of the tumour boundary and area were compared using a nonparametric multi-group comparison (Friedman M). The McNemar test was applied to examine differences in the detection rate of tumour boundaries. Among four different MRI sequences, SWI exhibited increased conspicuity of the tumour boundary than the conventional MRI (P < 0.001). SWI (91.8%) and CE-MRI (64.4%) exhibited higher detection rates of the tumour boundary than T1WI and T2WI (6.8% and 12.3% respectively). Longer tumour maximum diameters were measured with SWI (29.1 ± 17.2 mm) and CE-MRI (28.2 ± 16.8) compared to conventional MRI (P < 0.05). 2D multibreath-hold SWI enables enhanced noninvasive detection of tumour boundaries in patients with MLD compared with conventional MRI and CE-MRI without using an exogenous contrast agent. SWI has the potential to become a preoperative assessment standard that complements conventional MRI. [ABSTRACT FROM AUTHOR]

Diffuse axonal injury (DAI) is one of the most severe types of primary traumatic brain injury. In recent years, MR imaging has been gaining popularity as an adjunctive imaging method in patients with DAI. In this case report, we describe MRI findings of an 11-year-old male patient diagnosed with DAI and discuss the role of different sequences in the evaluation of DAI.

OBJECTIVES:A precise assessment of angioarchitectural characteristics using noninvasive imaging is helpful for serial follow-up and weighting risk of natural history in unruptured brain arteriovenous malformation (bAVM). This study aimed to test the hypothesis that susceptibility weighted imaging (SWI) would provide an accurate evaluation of angioarchitectural features of unruptured bAVM. METHODS:A total of 81 consecutive patients with unruptured bAVM were examined. Image quality of SWI for the assessment of bAVM angioarchitectural features was determined by a 5-point scale. The accuracy of SWI for detection of angioarchitectural features was evaluated using digital subtraction angiography as a standard reference and further compared among unruptured bAVMs with or without silent intralesional microhemorrhage on SWI to examine the potential confounding effect of microhemorrhage on image analysis. RESULTS:All lesions were identified on SWI. Image quality of SWI was judged to be at least adequate for diagnosis (range, 3-5) in all patients by both readers. Using digital subtraction angiography as a reference standard, the area under the receiver operating curve of detection of deep or posterior fossa location, exclusively deep venous drainage, venous ectasia, venous varices, and the presence of associated aneurysm on SWI was 1, 0.93, 0.94, 0.95, and 0.83, respectively. Silent intralesional microhemorrhage were detected in 39 patients (48.15%) on SWI and no significant difference (P > 0.05) was found in angioarchitectural features between patients with and without silent microhemorrhage. CONCLUSIONS:SWI might be a noninvasive alternative technique for angiography in the angioarchitectural assessment of unruptured bAVM.

Background and purposeWith extensive research efforts in place to address the clinical relevance of cerebral microbleeds (CMBs), there remains a need for fast and accurate methods to detect and quantify CMB burden. Although some computer-aided detection algorithms have been proposed in the literature with high sensitivity, their specificity remains consistently poor. More sophisticated machine learning methods appear to be promising in their ability to minimize false positives (FP) through high-level feature extraction and the discrimination of hard-mimics. To achieve superior performance, these methods require sizable amounts of precisely labelled training data. Here we present a user-guided tool for semi-automated CMB detection and volume segmentation, offering high specificity for routine use and FP labelling capabilities to ease and expedite the process of generating labelled training data.Materials and methodsExisting computer-aided detection methods reported by our group were extended to include fully-automated segmentation and user-guided CMB classification with FP labelling. The algorithm's performance was evaluated on a test set of ten patients exhibiting radiotherapy-induced CMBs on MR images.ResultsThe initial algorithm's base sensitivity was maintained at 86.7%. FP's were reduced to inter-rater variations and segmentation results were in 98% agreement with ground truth labelling. There was an approximate 5-fold reduction in the time users spent evaluating CMB burden with the algorithm versus without computer aid. The Intra-class Correlation Coefficient for inter-rater agreement was 0.97 CI[0.92,0.99].ConclusionsThis development serves as a valuable tool for routine evaluation of CMB burden and data labelling to improve CMB classification with machine learning. The algorithm is available to the public on GitHub (https://github.com/LupoLab-UCSF/CMB_labeler).

Background: Phase images contains information regarding local susceptibility changes between the tissues, which can help measure the iron and other content which changes the local field. Typically, this information is ignored before looking at console. Susceptibility weighted imaging (SWI) is a magnetic resonance (MR) technique detects an early hemorrhagic transformation within the infarct to provide insight into cerebral hemodynamics following the stroke. Objective: Significance of “phase mask imaging in differentiation of hemorrhage and calcifications†in acute stroke patients. Methods: An observational non-interventional study carried out on 100 patients with stroke and headache symptoms. MRI Brain Stroke Profile with FLAIR, DWI, ADC, SWAN, and Phase mask sequences, done on 3T GE MRI scanner. Results: All patients underwent MRI study with SWI sequence. Of 183 cases, 33%(n=60) patients had microbleeds, 5%(n=10) patients had granulomas, 32%(n=58) patients had arterial thrombus with infarct, 11%(n=20) patients had falx calcifications, 11%(n=20) patients had intraparenchymal haemorrhage, and 8%(n=15) patients had infarcts with haemorrhagic transformation. The sensitivity of phase imaging in the detection of calcification was 90%. Conclusion: Phase mask imaging plays an important role to detect intracranial calcifications and chronic microbleeds. Phase mask imaging acts as a supplement tool in acute stroke patients, which guides further management.

The study aimed to investigate the hemodynamic features and independent predictors of neoangiogenesis after revascularization in moyamoya disease (MMD) by pseudocontinuous arterial spin labeling magnetic resonance imaging (pCASL MRI). Thirty-nine MMD patients were categorized into infarction group, hemorrhagic group, and atypical group. All patients underwent combined bypass surgery and pCASL MRI with postlabeling delays (PLD) of 1525 ms and 2525 ms. Absolute CBF MCA (cerebral blood flow in middle cerebral artery territory), relative CBF MCA (CBF MCA 2525 ms/CBF MCA 1525 ms), and spatial coefficient of variation of MCA (CoV MCA) were analyzed. Relationships between CBF MCA and the following clinical parameters were assessed: Suzuki stage, modified Rankin scale (mRS), cerebrovascular accident lesion score, and deep medullary veins score. Potential predictors for favorable neoangiogenesis and hemodynamic changes were explored as well. Preoperative CBF MCA differed among MMD patients with variable clinical presentations, Matsushima stages, modified Rankin Scale scores, CVA scores, and deep medullary vein scores. After bypass surgery, mean CBF MCA increased significantly in the infarction group (P = 0.027) and decreased in the hemorrhagic group (P = 0.043), while spatial CoV MCA was observed to decline in all groups. Higher preoperative relative CBF MCA and spatial CoV MCA were independent predictors for robust neoangiogenesis after bypass. The cutoff value of 0.330 of spatial CoV MCA at long PLD yielded the best sensitivity at 82.1% and specificity at 81.8%. Furthermore, both preoperative relative CBF MCA and spatial CoV MCA showed mild positive correlations with ΔmRS in MMD patients. pCASL-MRI with multiple PLDs could reflect preoperative hemodynamic impairment and predict the neoangiogenesis after combined bypass surgery in moyamoya patients. [ABSTRACT FROM AUTHOR]

Recent evidence suggests that the presence of magnetic susceptibility changes in MS lesions correlates with patients' expanded disability status scale (EDSS). This study evaluated the presence of ring lesions (RLs) and non-RLs, as well as changes in lesion susceptibility and lesion volume over a two-year time period in relapsing-remitting multiple sclerosis (RRMS) patients and compared these measures to the EDSS. Longitudinal cohort. A total of forty-three (43) patients with RRMS were recruited for this study. All subjects underwent 3 T MRI at baseline and forty-one (41) subjects had follow-up scans over a two-year period. The protocol included T2 fluid attenuated inversion recovery (FLAIR), pre- and post-contrast 2D T1-weighted gradient echo imaging and susceptibility weighted imaging (SWI) sequences. All data were acquired prior to gadolinium-based contrast agent injection except for SWI and post-contrast T1-weighted data. Mean and peak susceptibilities of lesions were measured using quantitative susceptibility mapping (QSM). For the RLs, inner−/outer-diameters from SWI data and absolute intensity from the FLAIR data were measured. The susceptibility and volumes of RLs and non-RLs were correlated with EDSS. The number of RLs correlated positively with EDSS (p -value = 0.04), but the RL volumes did not show a correlation with EDSS. Measurements of the annular ring and regions with high susceptibility remained constant over time (p = 0.2). For non-ring QSM-positive (QSM+) lesions, the average susceptibility was significantly correlated to EDSS (p < 0.01.) This was also the case for lesion volume, as well as the product of volume and susceptibility when compared to EDSS (p < 0.01 for both). The susceptibility distribution and lesion volumes for the RLs remained almost constant over time, suggesting that the changes in pathophysiology of the RLs is a gradual process. On the other hand, the presence of more than one RL along with both volume and susceptibility of non-RL QSM+ lesions were significantly associated with increased disability as measured by EDSS. These findings may strengthen the role of QSM in assessing MS patients radiologically. [ABSTRACT FROM AUTHOR]

Background and purpose: We previously established a radiological protocol to discriminate multiple system atrophy-parkinsonian subtype (MSA-P) from Parkinson’s disease (PD). However, we do not know if it can differentiate early stage disease. This study aimed to investigate whether the morphological and intensity changes in susceptibility weighted imaging (SWI) of the lentiform nucleus (LN) could discriminate MSA-P from PD at early stages. Methods: We retrospectively enrolled patients with MSA-P, PD and sex- and age-matched controls whose brain MRI included SWI, between January 2015 and July 2020 at the Movement Disorder Center. Two specialists at the center reviewed the medical records and made the final diagnosis, and two experienced neuroradiologists performed MRI analysis, based on a defined and revised protocol for conducting morphological measurements of the LN and signal intensity. Results: Nineteen patients with MSA-P and 19 patients with PD, with less than 2 years of disease duration, and 19 control individuals were enrolled in this study. We found that patients with MSA- P presented significantly decreased size in the short line (SL) and corrected short line (cSL), ratio of the SL to the long line (SLLr) and corrected SLLr (cSLLr) of the LN, increased standard deviation of signal intensity (SIsd_LN, cSIsd_LN) compared to patients with PD and controls (P < 0.05). With receiver operating characteristic (ROC) analysis, this finding had a sensitivity of 89.5% and a specificity of 73.7% to distinguish MSA- P from PD. Conclusion: Compared to PD and controls, patients with MSA-P are characterized by a narrowing morphology of the posterior region of the LN. Quantitative morphological changes provide a reference for clinical auxiliary diagnosis. [ABSTRACT FROM AUTHOR]

Cerebral amyloid angiopathy related inflammation (CAA-ri) is a rare encephalopathy resulting from perivascular inflammation after β-βamyloid (A) deposition in cerebral vessels leading to progressive dementia, focal neurological signs, seizures and intracerebral hemorrhages. This condition is characterized on magnetic resonance imaging (MRI) by patchy or confluent T2/fluid attenuation inversion recovery (FLAIR) hyperintensities in the cortex and subcortical white matter located mainly in the same areas of pre-existing multiple microhemorrhages. In this report of 2 cases of “probable” CAA-ri women aged 71 and 68, we propose a review on the pathophysiological, clinical, radiological, therapeutic and prognostic aspects of this little-known and poor outcome condition.Even though an apparently favorable initial evolution after steroid and/or immunosuppressive treatment, CAA-ri course is unpredictable and often associated with low survival rates. We suggest the importance of timely and proper clinico-radiological evaluation in suspected CAA-ri cases, in order to start an appropriate treatment even without the brain biopsy.

Aim: The detection and segmentation of cerebral microbleeds (CMBs) images are the focus of clinical diagnosis and treatment. However, segmentation is difficult in clinical practice, and missed diagnosis may occur. Few related studies on the automated segmentation of CMB images have been performed, and we provide the most effective CMB segmentation to date using an automated segmentation system.Materials and Methods: From a research perspective, we focused on the automated segmentation of CMB targets in susceptibility weighted imaging (SWI) for the first time and then constructed a deep learning network focused on the segmentation of micro-objects. We collected and marked clinical datasets and proposed a new medical micro-object cascade network (MMOC-Net). In the first stage, U-Net was utilized to select the region of interest (ROI). In the second stage, we utilized a full-resolution network (FRN) to complete fine segmentation. We also incorporated residual atrous spatial pyramid pooling (R-ASPP) and a new joint loss function.Results: The most suitable segmentation result was achieved with a ROI size of 32 × 32. To verify the validity of each part of the method, ablation studies were performed, which showed that the best segmentation results were obtained when FRN, R-ASPP and the combined loss function were used simultaneously. Under these conditions, the obtained Dice similarity coefficient (DSC) value was 87.93% and the F2-score (F2) value was 90.69%. We also innovatively developed a visual clinical diagnosis system that can provide effective support for clinical diagnosis and treatment decisions.Conclusions: We created the MMOC-Net method to perform the automated segmentation task of CMBs in an SWI and obtained better segmentation performance; hence, this pioneering method has research significance.

Mild traumatic brain injury (mTBI) accounts for more than 80% of the total number of TBI cases. The mechanism of injury for patients with mTBI has a variety of neuropathological processes. However, the underlying neurophysiological mechanism of the mTBI is unclear, which affects the early diagnosis, treatment decision-making, and prognosis evaluation. More and more multimodal magnetic resonance imaging (MRI) techniques have been applied for the diagnosis of mTBI, such as functional magnetic resonance imaging (fMRI), arterial spin labeling (ASL) perfusion imaging, susceptibility-weighted imaging (SWI), and diffusion MRI (dMRI). Various imaging techniques require to be used in combination with neuroimaging examinations for patients with mTBI. The understanding of the neuropathological mechanism of mTBI has been improved based on different angles. In this review, we have summarized the application of these aforementioned multimodal MRI techniques in mTBI and evaluated its benefits and drawbacks. [ABSTRACT FROM AUTHOR]

Amyotrophic lateral sclerosis (ALS) results in progressive impairment of upper and lower motor neurons. Increasing evidence from both in vivo and ex vivo studies suggest that iron accumulation in the motor cortex is a neuropathological hallmark in ALS. An in vivo neuroimaging marker of iron dysregulation in ALS would be useful in disease diagnosis and prognosis. Magnetic resonance imaging (MRI), with its unique capability to generate a variety of soft tissue contrasts, provides opportunities to image iron distribution in the human brain with millimeter to sub‐millimeter anatomical resolution. Conventionally, MRI T1‐weighted, T2‐weighted, and T2*‐weighted images have been used to investigate iron dysregulation in the brain in vivo. Susceptibility weighted imaging has enhanced contrast for para‐magnetic materials that provides superior sensitivity to iron in vivo. Recently, the development of quantitative susceptibility mapping (QSM) has realized the possibility of using quantitative assessments of magnetic susceptibility measures in brain tissues as a surrogate measurement of in vivo brain iron. In this review, we provide an overview of MRI techniques that have been used to investigate iron dysregulation in ALS in vivo. The potential uses, strengths, and limitations of these techniques in clinical trials, disease diagnosis, and prognosis are presented and discussed. We recommend further longitudinal studies with appropriate cohort characterization to validate the efficacy of these techniques. We conclude that quantitative iron assessment using recent advances in MRI including QSM holds great potential to be a sensitive diagnostic and prognostic marker in ALS. The use of multimodal neuroimaging markers in combination with iron imaging may also offer improved sensitivity in ALS diagnosis and prognosis that could make a major contribution to clinical care and treatment trials. Level of Evidence: 2 Technical Efficacy: Stage 3 [ABSTRACT FROM AUTHOR]

The magnetism of hemoglobin - being paramagnetic in its deoxy and diamagnetic in its oxy state - offers unique opportunities to probe oxygen metabolism in blood and tissues. The magnetic susceptibility χ of blood scales linearly with blood oxygen saturation, which can be obtained by measuring the magnetic field ΔB of the intravascular MR signal relative to tissue. In contrast to χ, the induced field ΔB is non-local. Therefore, to obtain the intravascular susceptibility Δχ relative to adjoining tissue from the measured ΔB demands solution of an inverse problem. Fortunately, for ellipsoidal structures, to which a straight, cylindrically shaped blood vessel segment conforms, the solution is trivial. The article reviews the principle of MR susceptometry-based blood oximetry. It then discusses applications for quantification of whole-brain oxygen extraction - typically on the basis of a measurement in the superior sagittal sinus - and, in conjunction with total cerebral blood flow, the cerebral metabolic rate of oxygen (CMRO2 ). By simultaneously measuring flow and venous oxygen saturation (SvO2 ) a temporal resolution of a few seconds can be achieved, allowing the study of the response to non-steady-state challenges such as volitional apnea. Extensions to regional measurements in smaller cerebral veins are also possible, as well as voxelwise quantification of venous blood saturation in cerebral veins accomplished by quantitative susceptibility mapping (QSM) techniques. Applications of susceptometry-based oximetry to studies of metabolic and degenerative disorders of the brain are reviewed. Lastly, the technique is shown to be applicable to other organ systems such as the extremities using SvO2 as a dynamic tracer to monitor the kinetics of the microvascular response to induced ischemia. Copyright © 2016 John Wiley & Sons, Ltd.

BackgroundCerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common genetic cause of stroke. In addition to ischemic stroke, CADASIL predisposes to development of cerebral microbleeds (CMB). CMB and hypertension are known to be associated with intracerebral hemorrhage (ICH). The purpose of this study was to analyze the relationships among CMB, hypertension, and ICH in CADASIL.Materials and methodsWe enrolled 94 genetically confirmed CADASIL patients from 76 unrelated families at Jeju National University Hospital (Korea) between March 2012 and February 2015. We analyzed CMB presence, number, and distribution on susceptibility-weighted imaging MRI using the microbleed anatomical rating scale. Multiple logistic regression was used to determine factors associated with the presence of CMB and ICH.ResultsCMB were observed in 62 patients (66%), median number of CMB per patient was 4 (range 0-121). Twenty-two ICHs were found in 16 patients (17%). There was incongruence between the most common site of CMB (thalamus) and that of ICH (basal ganglia). Hypertension was independently associated with the presence of CMB (multiple regression OR, 2.71; 95% CI 1.02-7.18, p