Susceptibility-weighted Imaging Sequences Research Articles

Magnetic resonance imaging scanning susceptibility weighted imaging sequences in the diagnosis and prognostic evaluation of neonatal hypoxic-ischemic encephalopathy

BACKGROUND Magnetic resonance imaging (MRI) scanning with susceptibility weighted imaging (SWI) sequences plays a significant role in the diagnosis and prognostic evaluation of neonatal hypoxic-ischemic encephalopathy (HIE). AIM To observe the role of MRI multi-parameter quantitative indexes in the diagnosis of neonatal HIE. METHODS The imaging data from 23 cases of neonatal HIE admitted to the Imaging Department of Ganyu District People's Hospital of Lianyungang City and 23 neonates without HIE admitted during the same period were analyzed retrospectively from August, 2021 to December, 2023. The results of clinical judgment were compared with the results of computed tomography (CT) and MRI examinations. RESULTS The degree of cerebral edema (more than moderate), the number of damaged brain regions (> 2), the number of cerebral hemorrhages (> 2), and the percentage of small venous dilatation detected were higher in MRI than in CT examination, and the differences were statistically significant (P < 0.05). The total area of the largest region of cerebral damage and of cerebral hemorrhage observed by MRI examination were significantly larger than those of CT examination (P < 0.01). Multiparametric quantitative MRI combined with diffusion weighted imaging and SWI had higher sensitivity and accuracy than CT diagnosis, and the difference was statistically significant (P < 0.05). The difference in the specificity of the two modes of diagnosis was not significant (P > 0.05). CONCLUSION The use of MRI multi-parameter quantitative indexes can accurately diagnose and evaluate neonatal HIE.

Correlation between asymmetrical vein sign of SWI and long-term clinical outcomes in patients with middle cerebral artery ischemic stroke.

To evaluate the association of asymmetrical cortical vein sign (ACVS) and asymmetrical medullary vein sign (AMVS) on susceptibility-weighted imaging (SWI) with 90-day poor outcomes in patients with unilateral middle cerebral artery acute ischemic stroke (AIS) after conservative drug treatment. Clinical data for the participants included age, sex, smoking, alcohol, hypertension, diabetes, hyperlipidemia, coronary heart disease, NHISS-admission, and NHISS-discharge scores. Participants underwent magnetic resonance imaging (MRI) within 12h of hospital admission, including conventional scan sequences and a SWI sequence. Poor prognosis was defined as a modified Rankin scale (mRS) ≥ 3 at 90days. A total of 108 patients were included from January 2021 to March 2022. Twenty-seven (25%) patients had a poor outcome at 90days. Univariate analysis indicated that diabetes, NHISS-admission, NHISS-discharge, DWI-ASPECTS, SWI-ASPECTS, FLAIR-ASPECTS, and AMVS + were associated with 90-day poor outcome. Multivariate regression analysis showed that AMVS + was associated with 90-day poor outcome from the three models (OR = 3.57, P = 0.006; OR = 3.74, P = 0.005; OR = 5.14, P = 0.0057). However, no significant association was found between ACVS + and 90-day poor outcome. AMVS might be a helpful neuroimaging predictor for poor outcome at 90days compared to ACVS in drug-conserving treatment of patients with unilateral middle cerebral artery ischemic stroke.

Multi-contrast echo-planar imaging sequence (Echo-planar imaging mix) in clinical situations demanding faster MRI-brain scans.

The excellent resolution offered by magnetic resonance imaging (MRI) has a trade-off in the form of scan duration. The purpose of the present study was to assess the clinical utility of echo-planar imaging mix (EPIMix), an echo-planar imaging-based MRI sequence for the brain with a short acquisition time. This was a retrospective observational study of 50 patients, who could benefit from faster MRI brain scans. The T1, T2, fluid attenuated inversion recovery, diffusion-weighted imaging (DWI), and T2*/susceptibility-weighted imaging sequences were acquired, conventionally and with EPIMix. Conventional and EPIMix images were assessed by two radiologists for overall quality, motion, and susceptibility artifacts and scored on a Likert scale. The scores given for conventional and EPIMix images were compared. The diagnostic performance of EPIMix was also assessed by the ability to detect clinically relevant findings. The acquisition time for conventional MRI was 11 min and 45 s and for EPIMix 1 min and 15 s. All EPIMix images were sufficient for diagnostic use. On assessment of the diagnostic performance, it was excellent for ischemic and hemorrhagic strokes. Smaller lesions, lesions adjacent to bone, and post-operative tumors were difficult to identify. Moderate to perfect agreement (Kappa values 0.41-1) was seen between radiologists for all categories except skull base, calvarial, and orbital lesions. Image quality, artifact assessment showed excellent interobserver agreement (>90%) for the scores. All EPIMix images showed reduced motion artifacts. The EPIMix-DWI was comparable to conventional-DWI in terms of quality and artifacts. The remaining sequences showed reduced quality and increased susceptibility. The EPIMix has a significantly reduced acquisition time than conventional MRI and could be used instead of conventional MRI in situations demanding faster scans such as suspected acute ischemic or hemorrhagic stroke. In other clinical scenarios, it could help tailor the MRI examination for each patient.

Evaluation of diagnostic value of pelvic MRI in endometriosis in comparison with surgical findings: A cross-sectional study.

Endometriosis is a multifocal gynecologic disorder during the fertility period in women. Magnetic resonance imaging (MRI) is an important diagnostic modality for this disease and can either be used alone or along with transvaginal ultrasonography. This study aims to compare the accuracy of pelvis MRI in pelvic deep endometriosis with laparoscopic findings in women referred to Shahid Sadoughi hospital in one year. This cross-sectional study was conducted on 40 women suspicious of endometriosis who referred to Shahid Sadoughi hospital, Yazd, Iran from November 2020-2021. Based on clinical findings and history, participants were referred to the imaging center for pelvic MRI. Finally, the results of MRI and diagnostic laparoscopy were compared with pathologic findings. The sensitivity and specificity of MRI for pelvic endometriosis were 94.8% and 20%, respectively. Also, the positive predictive value and negative predictive value of MRI were 90.2% and 33.3%, respectively. Laparoscopy is still the gold standard of endometriosis diagnosis, but MRI with susceptibility-weighted imaging sequence is the best noninvasive diagnostic method.

Simultaneous time-of-flight MR angiography and quantitative susceptibility mapping with key time-of-flight features.

A technique for combined time-of-flight (TOF) MR angiography (MRA) and quantitative susceptibility mapping (QSM) was developed with key features of standard three-dimensional (3D) TOF acquisitions, including multiple overlapping thin slab acquisition (MOTSA), ramped RF excitation, and venous saturation. The developed triple-echo 3D TOF-QSM sequence enabled TOF-MRA, susceptibility-weighted imaging (SWI), QSM, and R2* mapping. The effects of ramped RF, resolution, flip angle, venous saturation, and MOTSA were studied on QSM. Six volunteers were scanned at 3 T with the developed sequence, conventional TOF-MRA, and conventional SWI. Quantitative comparison of susceptibility values on QSM and normalized arterial and venous vessel-to-background contrasts on TOF and SWI were performed. The ramped RF excitation created an inherent phase variation in the raw phase. A generic correction factor was computed to remove the phase variation to obtain QSM without artifacts from the TOF-QSM sequence. No statistically significant difference was observed between the developed and standard QSM sequence for susceptibility values. However, maintaining standard TOF features led to compromises in signal-to-noise ratio for QSM and SWI, arising from the use of MOTSA rather than one large 3D slab, higher TOF spatial resolution, increased TOF background suppression due to larger flip angles, and reduced venous signal from venous saturation. In terms of vessel contrast, veins showed higher normalized contrast on SWI derived from TOF-QSM than the standard SWI sequence. While fast flowing arteries had reduced contrast compared with standard TOF-MRA, no statistical difference was observed for slow flowing arteries. Arterial contrast differences largely arise from the longer TR used in TOF-QSM over standard TOF-MRA to accommodate additional later echoes for SWI. In conclusion, although the sequence has a longer TR and slightly lower arterial contrast, provided an adequate correction is made for ramped RF excitation effects on phase, QSM may be performed from a multiecho sequence that includes all key TOF features, thus enabling simultaneous TOF-MRA, SWI, QSM, and R2* map computation.

MRI Otak Demensia: Protokol RSUP Dr. Sardjito Yogyakarta

Background: The procedure for examining brain magnetic resonance imaging (MRI) in clinical dementia at the Radiology Installation of RSUP dr. Sardjito Yogyakarta used T2W, 3D FLAIR, 3D FFE ADNI, diffusion weighted imaging (DWI) and susceptibility weighted imaging (SWI) sequences. The selection of this sequence was in accordance with the existing references, but was added with the SWI sequence. This study aims to determine the MRI brain examination in clinical dementia and to find out the reason for the addition of the SWI sequence.Methods: This type of research is a qualitative research with a case study approach. Data was collected by observation, in-depth interviews and documentation. Data analysis was carried out with the stages of data transcription, data reduction, data presentation and carried out discussions and drawing conclusions.Results: The results of the study stated that the measurement of brain volume was carried out by entering the raw data of the T1 FFE ADNI sequence image into the freesurfer software which was useful for assessing Alzheimer's dementia.Conclusions: The diagnosis is made by looking for bleeding and microbleeding using the SWI sequence in assessing vascular dementia. SWI sequences are useful in differentiating between calcification and microbleeding causing vascular dementia.

Prominent Vessel Signs After Endovascular Thrombectomy Corelates with Unexplained Neurological Deterioration and is a More Reliable Imaging Predictor of Prognosis in Anterior Large Vessel Occlusion Stroke

Fifty percent of patients who undergo endovascular thrombectomy (EVT) for large-vessel occlusion exhibit unfavorable outcomes. The primary factor is attributed to persistent brain impairment even after successful EVT. The prominent vessel sign (PVS) on magnetic resonance susceptibility-weighted imaging reflects the territory of dysmetabolism and may facilitate an expeditious assessment for prognostication. We aimed to examine the relationship between PVS after EVT and the occurrence of early neurological deterioration (END) and 3-month outcomes. Patients who underwent EVT and multimodal magnetic resonance imaging were included. END was defined as an increase of ≥2 in the National Institutes of Health Stroke Scale within 72 hours after EVT. Symptomatic intracranial hemorrhage, malignant edema, and surgical complications were defined as definite END, whereas the other symptoms were categorized as unexplained END (ux-END). The PVS-Alberta Stroke Program Early CT Score (ASPECTS) score was used to evaluate the asymmetric cerebral venous signal on the susceptibility-weighted imaging sequences semiquantitatively. A total of 116 eligible patients were included, 18 (15.5%) of whom presented with ux-END. The 72hour National Institutes of Health Stroke Scale was strongly correlated with diffusion-weighted imaging infarct volume and PVS-ASPECTS and was significantly higher in the ux-END group (16 ± 6 vs. 5 ± 4, P= 0.001). The PVS-ASPECTS score was significantly associated with poor outcomes (odds ratio 2.551, 95% confidence interval (CI) 1.722-3.780, P＜0.001), and PVS-ASPECTS (area under the curve 0.884, 95% CI 0.815-0.953, P<0.001) was superior to diffusion-weighted imaging infarct volume (area under the cure 0.720, 95% CI 0.620-0.820, P= 0.001) in predicting 3-month poor outcome. At the optimal cut-off of 2, the PVS-ASPECT predicted poor outcomes with a sensitivity of 89.7% and a specificity of 78.2%. PVS 72 hours after EVT correlated with ux-END. The PVS-ASPECTS is a more reliable predictor of stroke prognosis and provides valuable information regarding post-EVT management.

PERANAN SEQUENCE SWI (SUSCEPTIBILITY WEIGHTED IMAGING) PADA PEMERIKSAAN MRI BRAIN KLINIS PARKINSON

The Role of SWI (Susceptibility Weighted Imaging) Sequence in Clinical Parkinson’s MRI Brain Imaging. Magnetic Resonance Imaging (MRI) is a technique for imaging body crossings based on the principle of magnetic resonance of hydrogen atoms. Brain MRI examination aims to see anatomy and abnormalities within the brain to establish clinical diagnosis, pathological abnormalities, tumors, and surrounding abnormalities. Imaging examinations are also conducted to find other causes of Parkinsonism. Head MRI is one of the non-invasive examinations performed to help confirm the diagnosis of Parkinson's disease. This study aims to determine the procedure for Brain MRI examination with Parkinson's clinical and to determine the sequence information SWI (Susceptibility Weighted Imaging) can establish clinical diagnosis of Parkinson's. This study is qualitative descriptive with a case study approach. The subject consists of three patients with clinical Parkinson's. All subjects performed MRI brain 3 tesla examinations to determine the procedure and sequence information used. The research results were obtained according to the theory using an additional 2 mm sequence, while in the field using 0.9 mm sequence the examination was conducted using the head coil of the patient's position, namely supine, head first. Sequences used in field inspections are AAHead Scout, t1 fl2d transversal, t2 tse (time spin echo) dark fluid transversal, t2 tse (time spin echo) transversal, ep2d diff (diffusion) 4scan trace, asl 3d transversal, tof cs carotids, flow pc3d MRV (magnetic resonance venography), tof brain MRA (magnetic resonance angiography), t2 swi (susceptibility weighted imaging) 3d transversal 0.9 mm. The thin axial sequence of 0.9 mm is more likely to see Parkinson's anatomical abnormalities, higher SNR and better spatial resolution than using a 2 mm slice thickness.

Comparing CT-Like Images Based on Ultra-Short Echo Time and Gradient Echo T1-Weighted MRI Sequences for the Assessment of Vertebral Disorders Using Histology and True CT as the Reference Standard.

Several magnetic resonance (MR) techniques have been suggested for radiation-free imaging of osseous structures. To compare the diagnostic value of ultra-short echo time and gradient echo T1-weighted MRI for the assessment of vertebral pathologies using histology and computed tomography (CT) as the reference standard. Prospective. Fifty-nine lumbar vertebral bodies harvested from 20 human cadavers (donor age 73 ± 13 years; 9 male). Ultra-short echo time sequence optimized for both bone (UTEb) and cartilage (UTEc) imaging and 3D T1-weighted gradient-echo sequence (T1GRE) at 3 T; susceptibility-weighted imaging (SWI) gradient echo sequence at 1.5 T. CT was performed on a dual-layer dual-energy CT scanner using a routine clinical protocol. Histopathology and conventional CT were acquired as standard of reference. Semi-quantitative and quantitative morphological features of degenerative changes of the spines were evaluated by four radiologists independently on CT and MR images independently and blinded to all other information. Features assessed were osteophytes, endplate sclerosis, visualization of cartilaginous endplate, facet joint degeneration, presence of Schmorl's nodes, and vertebral dimensions. Vertebral disorders were assessed by a pathologist on histology. Agreement between T1GRE, SWI, UTEc, and UTEb sequences and CT imaging and histology as standard of reference were assessed using Fleiss' κ and intra-class correlation coefficients, respectively. For the morphological assessment of osteophytes and endplate sclerosis, the overall agreement between SWI, T1GRE, UTEb, and UTEc with the reference standard (histology combined with CT) was moderate to almost perfect for all readers (osteophytes: SWI, κ range: 0.68-0.76; T1GRE: 0.92-1.00; UTEb: 0.92-1.00; UTEc: 0.77-0.85; sclerosis: SWI, κ range: 0.60-0.70; T1GRE: 0.77-0.82; UTEb: 0.81-0.92; UTEc: 0.61-0.71). For the visualization of the cartilaginous endplate, UTEc showed the overall best agreement with the reference standard (histology) for all readers (κ range: 0.85-0.93). Morphological assessment of vertebral pathologies was feasible and accurate using the MR-based bone imaging sequences compared to CT and histopathology. T1GRE showed the overall best performance for osseous changes and UTEc for the visualization of the cartilaginous endplate. 1 TECHNICAL EFFICACY: Stage 2.

Cerebral microbleeds. Utility of SWI sequences

ObjectivesDefine the concept of cerebral microbleeds (CMBs) and describe the most useful MRI sequences for detecting this finding.Review the entities that most frequently present with CMBs and that may benefit from the use of susceptibility-weighted imaging (SWI) sequences. ConclusionsSWI is a useful MRI sequence for the detection and characterization of microhemorrhages, venous structures and other sources of susceptibility in imaging.SWI is particularly sensitive to local magnetic field inhomogeneities generated by certain substances and is superior to T2* GRE sequences for this assessment.CMBs may be seen in different neurologic conditions, in certain infrequent clinical contexts and have a key role as a biomarker status in gliomas (ITTS) and as a marker of inflammatory activity in multiple sclerosis.

Association of brain microbleeds with risk factors, cognition, and MRI markers in MESA.

Little is known about the epidemiology of brain microbleeds in racially/ethnically diverse populations. In the Multi-Ethnic Study of Atherosclerosis, brain microbleeds were identified from 3T magnetic resonance imaging susceptibility-weighted imaging sequences using deep learning models followed by radiologist review. Among 1016 participants without prior stroke (25% Black, 15% Chinese, 19% Hispanic, 41% White, mean age 72), microbleed prevalence was 20% at age 60 to 64.9 and 45% at ≥85 years. Deep microbleeds were associated with older age, hypertension, higher body mass index, and atrial fibrillation, and lobar microbleeds with male sex and atrial fibrillation. Overall, microbleeds were associated with greater white matter hyperintensity volume and lower total white matter fractional anisotropy. Results suggest differing associations for lobar versus deep locations. Sensitive microbleed quantification will facilitate future longitudinal studies of their potential role as an early indicator of vascular pathology.

Cerebral Microbleeds-Long-Term Outcome After Cerebrospinal Fluid Shunting in Idiopathic Normal Pressure Hydrocephalus.

Cerebral microbleeds (CMBs) are common in idiopathic normal pressure hydrocephalus (INPH) and have been suggested as radiological markers of a brain prone to bleeding. The presence of CMBs might be relevant when selecting patients for shunt surgery. To evaluate whether CMBs increases long-term risk of hemorrhagic complications and mortality or affects outcomes after cerebrospinal fluid shunt surgery in a cohort of patients with INPH. One hundred and forty nine shunted patients with INPH (mean age, 73 years) were investigated with MRI (T2* or susceptibility-weighted imaging sequences) preoperatively. CMBs were scored with the Microbleed Anatomic Rating Scale. Patients were observed for a mean of 6.5 years (range 2 weeks to 13 years) after surgery. Hemorrhagic events and death were noted. Improvement in gait was evaluated 3 to 6 months after surgery. At baseline, 74 patients (50%) had CMBs. During follow-up, 7 patients (5%) suffered a hemorrhagic stroke and 43 (29%) suffered a subdural hematoma/hygroma with a median time from surgery of 30.2 months (IQR 50). Overall, having CMBs was not associated with suffering a subdural hematoma/hygroma or hemorrhagic stroke during follow-up with 1 exception that an extensive degree of CMBs (≥50 CMB) was more common in patients suffering a hemorrhagic stroke ( P = .03). CMBs were associated with increased mortality ( P = .02, Kaplan-Meier, log-rank test). The presence of CMBs did not affect gait outcome ( P = .28). CMBs were associated with hemorrhagic stroke and mortality. CMBs do not seem to reduce the possibility of gait improvement after shunt surgery or contribute to the risk of hemorrhagic complications regarding subdural hematoma or hygroma.

Susceptibility artifact morphology is more conspicuous on susceptibility-weighted imaging compared to T2* gradient echo sequences in the brains of dogs and cats with suspected intracranial disease.

Susceptibility-weighted imaging (SWI) has been found to be more reliable in the detection of vessels and blood products than T2*-weighted gradient echo (GE) in several human brain diseases. In veterinary medicine, published information on the diagnostic usefulness of SWI is lacking. The aim of this retrospective observational study was to investigate the value of SWI compared to T2*-weighted GE images in a population of dogs and cats with presumed, MRI-based diagnoses grouped as neoplastic (27), cerebrovascular (14), inflammatory (14), head trauma (5), other pathologies (4), or that were normal (36). Areas of signal void (ASV) were assessed based on shape, distribution, number, and conspicuity. Presence of ASV was found in 31 T2*-weighted GE and 40 SWI sequences; the conspicuity of lesions increased in 92.5% of cases with SWI. A 44.7% increase in the number of cerebral microbleeds (CMBs) was identified within the population using SWI (110) compared to T2*-weighted GE (76). Linear ASV presumed to be abnormal vascular structures, as are reported in humans, were identified in 12 T2*-weighted GE and 19 SWI sequences. In presumed brain tumors, abnormal vascular structures were detected in 11 of 27 (40.7%) cases on T2*-weighted GE and in 16 of 27 (59.3%) cases on SWI, likely representing tumor neovascularization; amorphous ASV interpreted as presumed hemorrhages on T2*-weighted GE were diagnosed as vessels on SWI in five of 27 (18.5%) cases. Since SWI shows ASV more conspicuously than T2*-weighted GE, the authors advocate the use of SWI in veterinary patients.

Value of 3.0T MRI T2 mapping combined with SWI for the assessment of early lesions in hemophilic arthropathy

ABSTRACT Purpose To explore the value of magnetic resonance imaging (MRI) T2 mapping combined with susceptibility-weighted imaging (SWI) in detecting early cartilage damage and joint bleeding in the hemophilic arthropathy (HA). Methods 147 patients and 56 healthy controls were prospectively recruited. The knees were divided into groups A and B according to the criteria of the International Cartilage Repair Society (ICRS). The Regions of Interest (ROIs) of T2 mapping were drawn for the patella, lateral and medial femoral condyle, and lateral and medial tibial condyle. The T2 values were compared between the patients and control group using one-way ANOVA. The joint count data of International Prophylaxis Study Group (IPSG) scores of conventional and SWI sequences were statistically described using the composition ratio, and the rank sum test was used for the difference analysis. Results Finally, there were 99 joints in the control group, 135 knees in group A, and 94 knees in group B. There was a significant difference between the T2 value in each subgroup. Comparison of T2 value groups in each cartilage partition, except for group A and group B of the patella, revealed significant differences (all P<0.05). SWI was likely more sensitive than conventional sequences in detecting hemosiderin deposits in hemophilic joints. In addition, the IPSG scores detected by the SWI were generally higher than those of conventional sequences. Conclusions MR T2 mapping combined with SWI has great potential to be used for detecting early cartilage damage and micro-hemosiderin deposition in hemophiliac arthropathies and developing preventative treatment plans.

&lt;I&gt;In vivo&lt;/I&gt; vascular mapping of the human hippocampus using MICRO imaging

BACKGROUND: There is an urgent need for better detection and understanding of vascular abnormalities at the micro-level, where critical vascular nourishment and cellular metabolic changes occur. This is especially the case for structures such as the midbrain and hippocampus, where both the feeding and draining vessels are quite small. The hippocampus is a complex grey matter structure that plays an important role in spatial and episodic memory. It can be affected by a wide range of pathologies including vascular abnormalities. Being able to monitor vascular changes in normal aging in various hippocampal subfields will allow us to better understand vascular vulnerability across the hippocampus.&#x0D; METHODS: We recently introduced the concept of microvascular in-vivo contrast revealed origins (MICRO) protocol to image micro-cerebral vessels.1-3 MICRO uses ferumoxytol, an ultra-small superparamagnetic iron oxides (USPIO) agent, to induce susceptibility in the arteries and veins; and by imaging with high resolution (0.22×0.44×1 mm3) susceptibility weighted imaging sequence (SWI) at 3 T. Although the increased vascular susceptibility enhances the visibility of small sub-voxel vessels, the accompanying strong signal loss of the large vessels deteriorates the local tissue contrast. Hence, data are collected at different time points during a gradual administration (final concentration = 4 mg/kg) of ferumoxytol. Dynamically acquired SWI data were co-registered and combined (phase gradient-based adaptive combination or SWIPGAC) to reduce the blooming artifacts from large vessels, preserving the small-vessel contrast.&#x0D; RESULTS: The presence of ferumoxytol helped to enhance the microvasculature, something that has previously only been demonstrated in cadaver brain studies. Figure 1 shows the difference between the pre-contrast SWI and SWIPGAC data in visualizing the micro-vasculature across four healthy subjects. The intra-hippocampal and superficial major arteries (obtained through a non-linear subtraction method) and veins (obtained by averaging the T1-shortening map, pre-contrast quantitative susceptibility mapping (QSM) and pre-contrast R2* maps) are used as an overlay in the third column to better visualize the major vessels penetrating and draining the hippocampus. The hippocampal fissure, along with the fimbria, granular cell layer of the dentate gyrus and cornu ammonis layers (except for CA1), showed higher micro-vascular density than the other parts of hippocampus. The CA1 region exhibited a significant correlation with age (R=−0.37, p&lt;0.05, n=37). demonstrating an overall loss of hippocampal vascularity in the normal aging process. Moreover, the vascular density reduction was more prominent than the age correlation with the volume reduction (R=−0.1, p&gt;0.05, n=37) of the CA1 subfield.&#x0D; CONCLUSIONS: With this USPIO-induced increase in susceptibility comes the potential to study the cerebral micro-vasculature using high-resolution SWI. There was a strong negative correlation between hippocampal functional vessel density (FVD) (especially in CA1) and age. This FVD reduction was more prominent than volume reduction vs age, suggesting that vascular atrophy may precede reductions in tissue volume. Mapping the hippocampal vasculature has immediate implications for understanding the effects of normal aging and the etiology of many neurovascular diseases. MICRO imaging brings us into the decade of imaging the microvasculature of the entire human body.

Prospective Associations of Susceptibility-Weighted Imaging Biomarkers with Fatigue Symptom Severity in Childhood Traumatic Brain Injury.

Fatigue may be among the most profound and debilitating consequences of pediatric traumatic brain injury (TBI); however, neurostructural risk factors associated with post-injury fatigue remain elusive. This prospective study aimed to evaluate the independent value of susceptibility-weighted imaging (SWI) biomarkers, over-and-above known risk factors, to predict fatigue symptom severity in children with TBI. Forty-two children were examined with structural magnetic resonance imaging (sMRI), including a SWI sequence, within eight weeks post-injury. The PedsQL Multi-Dimensional Fatigue Scale (MFS) was administered 24 months post-injury. Compared with population expectations, the TBI group displayed significantly higher levels of general fatigue (Cohen d = 0.44), cognitive fatigue (Cohen d = 0.59), sleep/rest fatigue (Cohen d = 0.37), and total fatigue (Cohen d = 0.63). In multi-variate models adjusted for TBI severity, child demographic factors, and depression, we found that subacute volume of SWI lesions was independently associated with all fatigue symptom domains. The magnitude of the brain-behavior relationship varied by fatigue symptom domain, such that the strongest relationships were observed for the cognitive fatigue and total fatigue symptom scales. Overall, we found that total subacute volume of SWI lesions explained up to 24% additional variance in multi-dimensional fatigue, over-and-above known risk factors. The subacute SWI has potential to improve prediction of post-injury fatigue in children with TBI. Our preliminary findings suggest that volume of SWI lesions may represent a novel, independent biomarker of post-injury fatigue, which could help to identify high-risk children who are likely to benefit from targeted psychoeducation and/or preventive strategies to minimize risk of long-term post-injury fatigue.

GNA11-mutated Sturge-Weber syndrome has distinct neurological and dermatological features.

Sturge-Weber syndrome (SWS) is a neurocutaneous disorder characterized by clinical manifestations involving the brain, eye and skin. SWS is commonly caused by somatic mutations in G protein subunit Alpha Q (GNAQ). Five cases of subunit Alpha 11 (GNA11) mutations have been reported. We studied phenotypic features of GNA11-SWS and compared them with those of classic SWS. Within two European multidisciplinary centers we looked for patients with clinical characteristics of SWS and a GNA11 mutation. Clinical and radiological data were collected retrospectively and prospectively. We identified three patients with SWS associated with a somatic GNA11 mutation. All had disseminated capillary malformation (CM) and hyper- or hypotrophy of an extremity. At birth, the CMs of the face, trunk and limbs were pink and patchy, and slowly darkened with age, evolving to a purple color. Two of the patients had glaucoma. All had neurological symptoms and moderate brain atrophy with a lower degree of severity than that classically associated with SWS. Susceptibility-weighted imaging (SWI) and contrast-enhanced fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging demonstrated the best sensitivity to reveal the pial angiomas. We have differentiated two distinct clinical/radiological phenotypes of SWS; GNAQ- and GNA11-SWS. The classic GNAQ-SWS is characterized by a homogeneous dark-red CM, commonly associated with underlying soft tissue hypertrophy. The CM in GNA11-SWS is more reticulate and darkens with time, and the neurological picture is milder. SWI and post-contrast FLAIR sequences appear to be necessary to demonstrate leptomeningeal angiomatosis. Anti-epileptic medication or future targeted therapies may be useful, as in classic SWS.

Capillary telangiectasia

Brain capillary telangiectasia is usually a small collection of dilated capillary-like vessels. In most cases it is aharmless incidental finding with no clinical significance. They are most commonly located in the pons. In terms of image morphology, they show brush-like signal extinction in T2*/SWI (susceptibility-weighted imaging) sequences and contrast enhancement in T1-weighted images. Other sequences are usually unremarkable unless they involve unusually large capillary telangiectasias. Angiographically they usually remain silent. Sometimes they are associated with venous abnormalities and/or cavernomas. Their distinctive radiographic features usually allow for areliable diagnosis. Differential diagnostic considerations, such as differentiation from atumorous or inflammatory process, are sometimes necessary.

Association between haemoglobin A1c and cerebral microbleeds in community-based stroke-free individuals: A cross-sectional study.

The association between haemoglobin A1c (HbA1c) and cerebral microbleeds (CMBs) remains unclear. We aimed to investigate the association between HbA1c and CMBs in community-based individuals without stroke or transient ischaemic attack (TIA) and whether the association differs between individuals with and without diabetes mellitus (DM). All individuals were recruited from a community in Beijing, China, from January 2015 to September 2019. All individuals completed a questionnaire and underwent blood tests and brain magnetic resonance imaging. A susceptibility-weighted imaging sequence was acquired to detect CMBs, which were defined as small, round and low-signal lesions with <10mm diameter. The association between HbA1c and CMBs was analysed using multivariable logistic regression adjusted for demographics, medical history and blood sample test results. Subgroup analyses stratified by history of DM were performed. Of 544 recruited individuals, 119 (21.88%) had CMBs. HbA1c was independently associated with CMBs (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.03-2.22). In 87 individuals with DM, multivariable logistic analysis showed that HbA1c was significantly associated with CMBs (OR, 1.67; 95% CI, 1.04-2.69), whereas in individuals without DM, no significant association was observed between HbA1c and CMBs (OR, 1.07; 95% CI, 0.50-2.30). HbA1c was associated with CMBs in individuals without stroke or TIA, particularly in individuals with DM, suggesting that the status of glycaemic control warrants attention for the prevention of CMBs. It would be beneficial to manage HbA1c specifically to control the risk of CMBs, especially in individuals with DM.

Hybrid [18F]-F-DOPA PET/MRI Interpretation Criteria and Scores for Glioma Follow-up After Radiotherapy.

18F‑fluoro-L‑3,4‑dihydroxyphenylalanine positron emission tomography (F‑DOPA PET) is used in glioma follow-up after radiotherapy to discriminate treatment-related changes (TRC) from tumor progression (TP). We compared the performances of acombined PET and MRI analysis with F‑DOPA current standard of interpretation. We included 76consecutive patients showing at least one gadolinium-enhanced lesion on the T1‑w MRI sequence (T1G). Two nuclear medicine physicians blindly analyzed PET/MRI images. In addition to the conventional PET analysis, they looked for F‑DOPA uptake(s) outside T1G-enhanced areas (T1G/PET), in the white matter (WM/PET), for T1G-enhanced lesion(s) without sufficiently concordant F‑DOPA uptake (T1G+/PET), and F‑DOPA uptake(s) away from hemorrhagic changes as shown with asusceptibility weighted imaging sequence (SWI/PET). We measured lesions' F‑DOPA uptake ratio using healthy brain background (TBR) and striatum (T/S) as references, and lesions' perfusion with arterial spin labelling cerebral blood flow maps (rCBF). Scores were determined by logistic regression. 53and 23patients were diagnosed with TP and TRC, respectively. The accuracies were 74% for T/S, 76% for TBR, and 84% for rCBF, with best cut-off values of 1.3, 3.7 and 1.25, respectively. For hybrid variables, best accuracies were obtained with conventional analysis (82%), T1G+/PET (82%) and SWI/PET (81%). T1G+/PET, SWI/PET and rCBF ≥ 1.25 were selected to construct a3-point score. It outperformed conventional analysis and rCBF with an AUC of 0.94 and an accuracy of 87%. Our scoring approach combining F‑DOPA PET and MRI provided better accuracy than conventional PET analyses for distinguishing TP from TRC in our patients after radiation therapy.