Infratentorial Research Articles

A study on various patterns of cranial metastases on MRI

Introduction: The radiological imaging plays a primary role to detect, localize, and diagnose the lesion. Various modalities which can be used are radiography, Computed imaging, Magnetic resonance imaging, Nuclear medicine and angiography. Except MRI, all other modalities involve exposure to radiation. Methodology: Fifty (n = 50) patients, who underwent surgery with histopathological diagnosis were included in the study. Written informed consent was obtained from all the patients for the study. Detailed clinical history was taken in all the patients. Results: Intraaxial was the most common compared to the extra axial location. Supra tentorial was most common than infra tentorial. Skull vault involvement was seen in 10% cases and dural metastases were seen in 18% cases. Conclusion: Brain metastasis is common among patients with systemic cancer. Brain metastasis (MET) is thought to occur when the primary tumor acquires the ability to migrate away from the primary site and travels to the brain.

Structural covariance in subcortical stroke patients measured by automated MRI-based volumetry.

A network-level investigation of the volumetric changes of subcortical stroke patients is still lacking. Here, we explored the alterations of structural covariance caused by subcortical stroke with automated brain volumetry. T1-weighed brain MRI scans were obtained from 63 normal controls (NC), 46 stroke patients with infarct in left internal capsule (CI_L), 33 stroke patients with infarct in right internal capsule (CI_R). We performed automatic anatomical segmentation of the T1-weighted brain images with AccuBrain. Volumetric structural covariance analyses were first performed within the basal ganglia structures that were both identified by voxel-based morphometry with AAL atlas and AccuBrain. Subsequently, we additionally included the infratentorial regions that were particularly quantified by AccuBrain for the structural covariance analyses and investigated the alterations of anatomical connections within these subcortical regions in CI_L and CI_R compared with NC. The association between the regional brain volumetry and motor function was also evaluated in stroke groups. There were significant and extensive volumetric differences in stroke patients. These significant regions were generally symmetric for CI_L and CI_R group depending on the side of stroke, involving both regions close to lesions and remote regions. The structural covariance analyses revealed the synergy volume alteration in subcortical regions both in CI_L and CI_R group. In addition, the alterations of volumetric structural covariance were more extensive in CI_L group than CI_R group. Moreover, we found that the subcortical regions with atrophy contributed to the deficits of motor function in CI_R group but not CI_L group, indicating a lesion-side effect of brain volumetric changes after stroke. These findings indicated that the chronic subcortical stroke patients have extensive disordered anatomical connections involving the whole-brain level network, and the connections patterns depend on the lesion-side.

Outcomes of surgical treatment of patients with infratentorial metastatic tumors

Мета: визначити показання до хірургічного втручання та лікувальну тактику при метастатичних новоутвореннях субтенторіальної локалізації. Матеріали і методи. У дослідженні взяли участь 162 пацієнта з метастатичними пухлинами субтенторіальної локалізації. Критерієм залучення в дослідження був вторинний характер неопластичного ураження структур задньої черепної ямки. Тотальне видалення вздовж перифокальної зони росту пухлини проведено 102 (79,7 %) пацієнтам, субтотальне – 9 (7 %), часткове – 8 (6,3 %). У 5 (3,9 %) хворих видалення пухлини поєднували з лікворошунтувальною операцією. В 4 (3,1 %) випадках хірургічна допомога полягала у встановленні лікворошунтувальної системи. Результати. Найчастішими джерелами метастазування в задню черепну ямку були легені (у 42 (32,8 %) хворих), молочна залоза (у 19 (14,8 %)) та меланома (у 15 (11,7 %)). До окремої групи віднесено пацієнтів з невідомим первинним вогнищем (32 (25 %)). Із 43 хворих з відомим катамнезом солітарні метастази мали 37 (86 %), множинні (зокрема суб-супратенторіальні) – 6 (14 %). Середня тривалість життя після операції у хворих із солітарними метастазами становила (8,4 ± 1,5) міс, з множинними (зокрема суб-супратенторіальними) – (5,1 ± 0,8) міс. Тривалість життя більше 1 року зафіксована у 13 (30,2 %) хворих, з них в 1 (2,3 %) з множинними метастазами. Висновки. Пацієнтам з метастатичними пухлинами субтенторіального простору, тяжкість стану яких зумовлена оклюзійною симптоматикою, навіть у разі <70 бала за шкалою Карновського показано проведення хірургічного втручання. Декомпресія задньої черепної ямки з відновленням ліквороциркуляції дає змогу поліпшити стан хворого та провести комбіноване лікування, а отже, продовжити тривалість життя.

Spinal cord and infratentorial lesions in radiologically isolated syndrome are associated with decreased retinal ganglion cell/inner plexiform layer thickness

Background: The role of retinal imaging with optical coherence tomography (OCT) in assessing individuals with radiologically isolated syndrome (RIS) remains largely unexplored. Objective: To assess retinal layer thicknesses in RIS and examine their associations with clinical features suggestive of increased risk for conversion to multiple sclerosis (MS). Methods: A total of 30 RIS subjects and 60 age- and sex-matched healthy controls (HC) underwent retinal imaging with spectral-domain OCT, followed by automated segmentation of retinal layers. Results: Overall, retinal layer thicknesses did not differ between RIS and HC. However, RIS subjects with spinal cord (SC) lesions had lower ganglion cell + inner plexiform layer (GCIP) thickness compared to HC (−4.41 μm; p = 0.007) and RIS without SC lesions (–3.53 μm; p = 0.041). Similarly, RIS subjects with infratentorial (IT) brain lesions had lower GCIP thickness compared to HC (–4.07 μm; p < 0.001) and RIS without IT lesions (–3.49 μm; p = 0.029). Multivariate analyses revealed that the presence of SC or IT lesions were independently associated with lower GCIP thickness in RIS (p = 0.04 and p = 0.03, respectively). Other patient characteristics, including sex, abnormal cerebrospinal fluid, and presence of gadolinium-enhancing or juxtacortical lesions, were not associated with retinal layer thicknesses. Conclusion: The presence of SC or IT lesions in RIS may be associated with retinal neuro-axonal loss, supporting the presence of more disseminated disease.

Should Spinal MRI Be Routinely Performed in Patients With Clinically Isolated Optic Neuritis?

Should Spinal MRI Be Routinely Performed in Patients With Clinically Isolated Optic Neuritis?

NIMG-72. A NOVEL ARRAY LAYOUT FOR DELIVERING TTFIELDS TO THE WHOLE BRAIN

INTRODUCTION: Tumor Treating Fields (TTFields) is an antimitotic cancer treatment approved for the treatment of Glioblastoma Multiforme. TTFields are delivered using 2 pairs of transducer arrays. When treating Glioblastoma, the array positioning on the head is planned to maximize TTFields dose delivered to the tumor. This results in an increased dose of TTFields at the tumor, whilst reducing the intensity of the field in other regions. In some clinical scenarios, such as treatment of multiple brain metastases, it might be desirable to deliver TTFields at therapeutic intensities to the entire brain, thereby ensuring that even microscopic lesions receive a therapeutic dose of TTFields. Here we present novel transducer array layouts designed to deliver a uniform distribution of TTFields to the entire brain. Methods Computer simulations were used to calculate the field distributions generated by different array layouts. The simulations utilized a realistic computerized head model of a 40+ years old human mal. Delivery of TTFields using pairs of array layouts placed at different locations on the head and neck was simulated using Sim4Life V3.0 (ZMT Zurich). To analyze the field distributions, the brain was divided into five regions: 1) the cerebellum, brain stem and other infra-tentorial anatomical regions; 2–5) four quadrant of the cerebrum. The mean and median field intensities in the five regions generated by each layout were calculated and compared. Results A layout in which one pair of arrays is placed on the right temple, and left scapula and the second pair placed on the left temple and right scapula yielded a uniform intensity distribution within the brain. (median intensities between 1.5 V/cm to 1.7 V/cm within all regions). Conclusion We have identified a novel TTFields array layout that will be beneficial in clinical scenarios where treatment of the entire brain with TTFields is desired.

Quantitative contrast study of sellar region by lateral orbital keyhole approach and conventional keyhole approach

Objective To compare lateral orbital keyhole approach(LOK) with conventional keyhole approach including supraorbital keyhole approach (SOK) and pterional approach(PTK) for exposuring the sellar region and operation ability, to provide theoretical and practical basis for the clinic. Methods From January, 2017 to Feburary, 2018, 15 cadaver head specimens of Chinese (30 sides) fixed by formalin were randomly divided into 3 groups, simulating SOK, LOK and PTK, application of frameless neuronavigation system, intersection of the posterior margin of the optic chiasma and the lamina terminalis served as the base point. Six different reference points were selected to radiate into the parasellar region of the skull base. The direction of the 2 adjacent reference points were connected to the base point to form a triangle. Six triangles constituted the sellar region to represent the total area. The supratentorial area, ipsilateral area, inferior area and contralateral area were calculated by stacking triangle. The comparison was made between groups. The Salma operation exposure scale was used to simulate the aneurysms of the common parts in the brain and the quantitative scores were performed. Results The total parasellar regions by SOK, LOK and PTK respectively were: (1641.6±295.6) mm2, (1782.3±294.6) mm2 and (1552.5±307.4) mm2. There was no statistical difference(P>0.05); To compare the supratentorial region, SOK and LOK were both bigger than PTK(P<0.05); To compare the ipsilateral and infratentorial area, LOK and PTK were both bigger than SOK respectively(P<0.05); To compare the contralateral area, SOK, LOK and PTK were increased in turn(P<0.05). Salma operation exposure scale was used to get the scores: the score of SOK was 29.7 (39.08%), LOK was 37.0 (48.68%), and PTK was 36.1 (47.50%). Conclusion Anatomical analysis displayed that the 3 keyhole approaches showed different exposure of each part the parasellar regions, the LOK had a good exposure to the parasellar region and so as the higher maneuverability. But the clinical application should be comprehensive analysis, pay attention to specific lesions and make an appropriate choice. It has important clinical significance to improve the prognosis of patients. Key words: Sellar region; Keyhole approach; Applied anatomy; Quantificative study

Diagnosis and Management of Brain Tumors in Children

Brain tumors are the second most common malignancy and the most common solid tumors found in childhood. During 11 months 19 patients with brain tumors were hospitalized at the Department of Child Health, Dr. Cipto Mangunkusurno Hospital, Jakarta, 10 of them were males. The youngest patient was 5 months old and the oldest was 13 years old. The important signs and symptoms in establishing diagnosis were the non-localizing signs and symptoms, i.e., nausea and vomiting. The most frequent localizing signs and symptoms were papilledema, cranial nerves palsy, ataxia and incoordination, hemiparesis, visual disturbances, and optic atrophy. Focal seizures were rare.&#x0D; Most of the tumors were in infratentorial region, and metastatic tumors were rare. The mortality of this series was high due to the severity of the disease. The most frequent of tumors are astrocytomas and medulloblastomas.

Predicting Dysphagia with National Institute of Health Stroke Scale: Distinction between Infra- and Supratentorial Region is Essential

Background: For the early detection of post-stroke dysphagia (PSD), valid screening parameters are crucial as part of a step-wise diagnostic procedure. This study examines the role of the National Institute of Health Stroke Scale (NIH-SS) as a potential low-threshold screening parameter. Methods: During a ten-year period, 687 newly admitted patients at University Hospital Muenster were included in a retrospective analysis, if they had ischemic or haemorrhagic stroke confirmed by neuroimaging and had received NIH-SS scoring and endoscopic swallowing evaluation upon admission. The NIH-SS score was correlated with dysphagia severity as measured by the validated 6-point fiberoptic endoscopic dysphagia severity score (FEDSS), and the ideal cut-off score to predict PSD, defined as FEDSS > 1, was calculated. Supra- and infratentorial strokes were analysed separately due to their differing role in the pathophysiology of neurogenic dysphagia. Results: NIH-SS and dysphagia severity show a significant positive correlation in the whole study population (R² = 0.745) as well as in both analysed subgroups (R² = 0.494 for supra- and R² = 0.646 for infratentorial strokes, p < 0.0005, respectively). For supratentorial strokes, the ideal NIH-SS cut-off is > 9 (sensitivity 68.3%, specificity 61.5%, positive predictive value 89.7%, negative predictive value 28.4%). For infratentorial strokes, a lower ideal cut-off > 5 was calculated (sensitivity 67.4%, specificity 85.0%, positive predictive value 95.1%, negative predictive value 37.8%). Conclusions: NIH-SS may be used as an adjunct to predict dysphagia in acute stroke patients with moderate sensitivity and specificity. Differentiation between supra- and infratentorial regions is essential not to miss dysphagia in infratentorial stroke.

Increased cerebral microbleeds and cortical superficial siderosis in pediatric patients with Down syndrome

Patients with Down syndrome carry a third copy of the amyloid precursor protein gene, which is localized on chromosome 21. Consequently, these patients are prone to develop early-onset Alzheimer disease and cerebral amyloid angiopathy. Post-mortem studies suggest increased amyloid deposition to be already detectable in children with Down syndrome. The aim of our study was to evaluate if amyloid-related changes in pediatric Down syndrome patients can be detected invivo using MRI biomarkers of cerebral microbleeds and cortical superficial siderosis. This retrospective study included 12 patients with Down syndrome (mean age=5.0 years) and 12 age-matched control subjects (mean age=4.8 years). Frequency and location of microbleeds and siderosis were assessed on blood-sensitive MRI sequences in a consensus reading by two radiologists applying a modified Microbleed Anatomical Rating Scale. Down syndrome patients showed a significantly higher mean microbleeds count and likelihood of siderosis than age-matched controls. Across groups, the highest microbleeds count was found in lobar regions (gray and white matter of frontal, parietal, temporal, and occipital lobes, and the insula), while fewer microbleeds were located in subcortical and infratentorial regions. The number of microbleeds increased over time in all three Down syndrome patients with a follow-up exam. Invivo MRI biomarkers can support the diagnosis of early-onset cerebral amyloid angiopathy, which might already be present in pediatric Down syndrome patients. This might contribute to clinical decision-making and potentially to the development of therapeutic and prophylactic approaches, as cerebral amyloid angiopathy increases the risk for intracranial hemorrhage and may be associated with increased risk of developing Alzheimer disease.

Acute contrecoup epidural hematoma that developed without skull fracture in two adults: two\xa0case reports

BackgroundThe incidence of acute epidural hematoma not accompanied by fracture is low, and it mostly occurs right below the impact point in children. Acute epidural hematoma on the contralateral side of the impact point without fracture is very rare.Case presentationCase 1: a 52-year-old Japanese woman fell and was bruised in the left occipital region, and acute epidural hematoma developed in the right frontal region. No fracture line was observed in the right frontal region on head computed tomography or during surgery, and the source of bleeding was the middle meningeal artery. Case 2: a 56-year-old Japanese man fell down the stairs and was bruised in the right occipital region, and acute epidural hematoma developed in the right occipital supra- and infratentorial regions and left frontal region. Separation of the lambdoid suture was noted in the right occipital region, but no fracture line was present in the left frontal region on either head computed tomography or during surgery, and the source of bleeding was the middle meningeal artery.ConclusionsTwo rare cases of frontal contrecoup acute epidural hematoma without facture near the hematoma were reported. It is possible that the dura mater detaches from the inner surface of the skull due to cavitation theory-related negative pressure and blood vessels in the dura mater are damaged, causing contrecoup acute epidural hematoma even though no fracture occurs, for which careful course observation is necessary.

Spontaneous Intracerebral Hemorrhage in a Plateau Area: A Study Based on the Tibetan Population

To reveal the characteristics of spontaneous intracerebral hemorrhage (sICH) in a plateau area based on the Tibetan population. Data of Tibetan and Han patients (control group) with sICH treated at our center from January 2013 to April 2017 were retrospectively reviewed. A total of 122 Tibetan and 927 Han patients were included. Compared with Han patients, Tibetan patients were older (54.7 ± 11.2 vs. 50.9 ± 18.3 years, P=0.027), exhibited higher male-to-female ratios (73.8% vs. 55.0%, P < 0.001), were more overweight (22.1% vs. 13.1%, P= 0.007) had more smokers (36.9% vs. 20.5%, P<0.001), had a higher concentration of hemoglobin (163.7 ± 17.6 vs. 134.8 ± 20.2 g/L, P<0.001), and included a higher number of patients with hypertension (83.6% vs. 60.5%, P<0.001), diabetes mellitus (19.2% vs. 9.3%, P= 0.002), and prior hemorrhagic stroke (9.0% vs. 2.0%, P < 0.001). Tibetan patients also experienced more brainstem hemorrhage (11.5% vs. 5.1%, P= 0.039) in the infratentorial region and had a higher risk of in-hospital complications resulting from hematoma enlargement (20.5% vs. 10.4%, P= 0.002) and cerebral infarction (59.0% vs. 9.7%, P< 0.001). During a 6-month follow-up period, they had higher rates of unfavorable outcomes and case mortality (P < 0.05). A multivariable analysis adjusted for confounding factors revealed that the Tibetan race was positively associated with unfavorable clinical outcomes in sICH patients (P < 0.05). Tibetan sICH patients from the plateau area presented unique characteristics in their baseline measurements, incidence of comorbidities, hematoma location, risk of in-hospital complications, and clinical outcomes compared with Han patients. The Tibetan race was positively associated with unfavorable 6-month outcomes in ICH patients.

Evaluation of the Detection Accuracy of Conventional Magnetic Resonance Imaging in Patients Diagnosed with Optic Neuritis

Introduction: Inflammation of the optic nerve is one of the most common causes of unilateral and/or bilateral blindness. The most common cause of this phenomenon is demyelinating processes which involve central nervous system and the diagnosis is suspected via clinical finding and confirmed by Magnetic Resonance Imaging (MRI). In this study we plan to investigate whether isolated conventional MRI is a reliable and sufficient diagnosing tool in approach to patients with clinical finings of optic neuritis. Methods: This retrospective study was performed in patients referred to neurology department of a private hospital in Tehran from 2012 to 2014, and underwent brain MRI after clinical diagnosis has been established. Clinical diagnosis of optic neuritis was confirmed by neuro-ophthalmological examination, visual field assessment and visual evoked potential (VEP). We have utilized SPSS program for statistical analysis, along with Student T-test and Chi-Square test. Result: Demographic analysis and data gathering were performed for all of the patients. Ninety patients were enrolled in the study, which 58 cases (64.4%) showed MRI abnormality in their neuro-imaging. In this group, supratentorial and infratentorial lesions were existed in 34 cases (58.6%) and 24 cases (41.3%) respectively. The most common affected sites of supratentorial region were periventricular region (in 17 cases), followed by juxtacortical (in 6 cases), basal ganglia (in 3 cases), corpus callosum (in 3 cases), centrum semiovale (in 2 cases) and in optic nerve in 3 patients. In patients with lesions in their infratentorial region, the most common sites were cerebellum hemispheres (in 11 cases), followed by mesencephalon (in 6 cases), pons (in 4 cases) and medulla oblongata (in 3 cases). Conclusion: We have found that conventional MRI as a single approach is not reliable in detecting enhancing plaques of white matter tracts in 35.6% of our enrolled cases who their diagnosis of optic neuritis were confirmed by visual field assessment and VEP. This issue raises the importance of addition of other enhancing technique to MRI for better localization of enhancement for multi-disciplinary approach.

Radiotherapy in acromegaly: Long-term brain parenchymal and vascular magnetic resonance changes

BackgroundRadiation therapy (RT) effectiveness on hormonal reduction is proven in acromegaly; however, collateral long-term effects are still undetermined. This transversal neuroimaging study on a large cohort of acromegalic patients aimed to investigate the rate of parenchymal and vascular changes after RT. Materials and methodsThirty-six acromegalic patients underwent RT (RT+) after unsuccessful surgery and were compared to RT− acromegalic patients matched for age, gender, adenoma features, clinical and surgical history. All patients underwent magnetic resonance angiography (MRA) to investigate intracranial artery abnormalities and FLAIR sequence to assess white matter changes according to the Wahlund scale. ResultsRT+ acromegalic patients had a higher rate of controlled disease (29/36 vs. 12/36, P<0.001). RT+ acromegalic patients had MRI/MRA evaluation 15.3±9.6 years after RT. RT+ acromegalic patients had a significantly higher Wahlund score than RT− acromegalic patients (6.03±6.41 vs. 2.53±3.66, P=0.006) due to increased white matter signal abnormalities at the level of the temporal lobes, the basal ganglia (insula) and the infratentorial regions, bilaterally. Among RT+ patients one died because of temporo-polar anaplastic astrocytoma, one suffered from a stroke due to right internal carotid artery occlusion, one presented with cystic degeneration of the temporal poles. Long-dated RT (>10 years before MR evaluation) was associated with a higher rate of RT-related white matter changes (P=0.0004). ConclusionsRT seems to have created a cohort of patients with brain parenchymal changes whose clinical and cognitive impact is still unknown. These patients might require a prolonged MRI and MRA follow-up to promptly detect delayed RT-related complications and minimize their clinical consequences.

Diagnostic potential of dentatorubrothalamic tract analysis in progressive supranuclear palsy

BackgroundThe differentiation of progressive supranuclear palsy-parkinsonism (PSP-P) from Parkinson's disease (PD) remains a major clinical challenge. ObjectivesTo evaluate the diagnostic potential of observer-independent assessments of microstructural integrity within infratentorial brain regions to differentiate PSP-Richardson's syndrome (PSP-RS), PSP-P and PD. Methods3T MRI parameters of mean diffusivity, fractional anisotropy, grey and white matter volumes from patients with PSP-RS (n = 12), PSP-P (n = 12) and mean disease duration of 2.4 ± 1.7 years were compared with PD patients (n = 20) and healthy controls (n = 23) by using statistical parametric mapping and the spatially unbiased infratentorial template. Subsequently MRI measurements of the dentatorubrothalamic tract were determined observer-independently by a validated probabilistic infratentorial atlas. The impairment of gait and postural stability was evaluated by a sum-score derived from the Unified Parkinson Disease Rating Scale. ResultsSignificant mean diffusivity increases, fractional anisotropy decreases and corresponding volume loss were localized in mesencephalic tegmentum, superior cerebellar peduncle, decussation of superior cerebellar peduncle and dentate nucleus in PSP-RS and PSP-P compared to PD and healthy controls. Altered microstructural integrity of the dentatorubrothalamic tract in PSP-RS was significantly more pronounced compared to PSP-P and correlated significantly with the gait and postural stability sum-score. Linear discriminant analysis identified diffusion tensor imaging measures of the dentatorubrothalamic tract and the gait and postural stability sum-score to classify correctly 95.5% of PRP-RS, PSP-P and PD patients. ConclusionsObserver-independent analysis of microstructural integrity within the dentatorubrothalamic tract in combination with assessments of gait and postural stability differentiate PSP-P from PSP-RS and PD in early to moderately advanced stages.

Location, number and factors associated with cerebral microbleeds in an Italian-British cohort of CADASIL patients.

Background and purposeThe frequency, clinical correlates, and risk factors of cerebral microbleeds (CMB) in Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) are still poorly known. We aimed at determining the location and number of CMB and their relationship with clinical manifestations, vascular risk factors, drugs, and other neuroimaging features in CADASIL patients.MethodsWe collected clinical data by means of a structured proforma and centrally evaluated CMB on magnetic resonance gradient echo sequences applying the Microbleed Anatomical Rating Scale in CADASIL patients seen in 2 referral centers in Italy and United Kingdom.ResultsWe evaluated 125 patients. CMB were present in 34% of patients and their presence was strongly influenced by the age. Twenty-nine percent of the patients had CMB in deep subcortical location, 22% in a lobar location, and 18% in infratentorial regions. After adjustment for age, factors significantly associated with a higher total number of CMB were hemorrhagic stroke, dementia, urge incontinence, and statins use (this latter not confirmed by multivariate analysis). Infratentorial and deep CMB were associated with dementia and urge incontinence, lobar CMB with hemorrhagic stroke, dementia, and statins use. Unexpectedly, patients with migraine, with or without aura, had a lower total, deep, and lobar number of CMB than patients without migraine.DiscussionCMB formation in CADASIL seems to increase with age. History of hemorrhagic stroke, dementia, urge incontinence, and statins use are associated with a higher number of CMB. However, these findings need to be confirmed by longitudinal studies.

Accuracy of the Compressed Sensing Accelerated 3D-FLAIR Sequence for the Detection of MS Plaques at 3T.

The use of 3D FLAIR improves the detection of brain lesions in MS patients, but requires long acquisition times. Compressed sensing reduces acquisition time by using the sparsity of MR images to randomly undersample the k-space. Our aim was to compare the image quality and diagnostic performance of 3D-FLAIR with and without compressed sensing for the detection of multiple sclerosis lesions at 3T. Twenty-three patients with relapsing-remitting MS underwent both conventional 3D-FLAIR and compressed sensing 3D-FLAIR on a 3T scanner (reduction in scan time 1 minute 25 seconds, 27%; compressed sensing factor of 1.3). Two blinded readers independently evaluated both conventional and compressed sensing FLAIR for image quality (SNR and contrast-to-noise ratio) and the number of MS lesions visible in the periventricular, intra-juxtacortical, infratentorial, and optic nerve regions. The volume of white matter lesions was measured with automatic postprocessing segmentation software for each FLAIR sequence. Image quality and the number of MS lesions detected by the readers were similar between the 2 FLAIR acquisitions (P = .74 and P = .094, respectively). Almost perfect agreement was found between both FLAIR acquisitions for total MS lesion count (Lin concordance correlation coefficient = 0.99). Agreement between conventional and compressed sensing FLAIR was almost perfect for periventricular and infratentorial lesions and substantial for intrajuxtacortical and optic nerve lesions. Postprocessing with the segmentation software did not reveal a significant difference between conventional and compressed sensing FLAIR in total MS lesion volume (P = .63) or the number of MS lesions (P = .15). With a compressed sensing factor of 1.3, 3D-FLAIR is 27% faster and preserves diagnostic performance for the detection of MS plaques at 3T.

Default mode network modifications in Fabry disease: A resting-state fMRI study with structural correlations.

Aim of the study was to evaluate the presence of Default Mode Network (DMN) modifications in Fabry Disease (FD), and their possible correlations with structural alterations and neuropsychological scores. Thirty-two FD patients with a genetically confirmed diagnosis of classical FD (12 males, mean age 43.3 ± 12.2) were enrolled, along with 35 healthy controls (HC) of comparable age and sex (14 males, mean age 42.1 ± 14.5). Resting-State fMRI data were analyzed using a seed-based approach, with six different seeds sampling the main hubs of the DMN. Structural modifications were assessed by means of Voxel-Based Morphometry (VBM) and Tract-Based Spatial Statistics analyses. Between-group differences and correlations with neuropsychological variables were probed voxelwise over the whole brain. Possible correlations between FC modifications and global measures of microstructural alteration were also tested in FD patients with a partial correlation analysis. In the FD group, clusters of increased functional connectivity involving both supratentorial and infratentorial regions emerged, partially correlated to the widespread white matter (WM) damage found in these patients. No gray matter volume differences were found at VBM between the two groups. The connectivity between right inferior frontal gyrus and precuneus was significantly correlated with the Corsi block-tapping test results (p = .0001). Widespread DMN changes are present in FD patients that correlate with WM alterations and cognitive performance. Our results confirm the current view of a cerebral involvement in FD patients not simply associated to major cerebrovascular events, but also related to significant and diffuse microstructural and functional changes.

Cerebral microbleeds and blood pressure abnormalities in Parkinson's disease.

Blood pressure abnormalities are frequently observed in patients with Parkinson's disease (PD), and are associated with cerebrovascular diseases such as white matter hyperintensities and carotid atherosclerosis. We assessed the relationship between blood pressure abnormalities and cerebral microbleeds (CMBs), a marker of cerebral small vessel disease, in 128 patients with PD. We examined supine and orthostatic blood pressures and used 24-hour ambulatory blood pressure monitoring to assess the presence or absence of orthostatic hypotension (OH), supine hypertension (SH), nocturnal hypertension (NH), and loss of nocturnal blood pressure dips (non-dipping). CMBs were found in 13 (10.2%) patients, and the median number of CMBs was 1 (range: 1 to 10). Six of these patients had deep or infratentorial CMBs, six had strictly lobar CMBs, and one had mixed CMBs. Linear regression analysis indicated that presence of both OH and SH was independently associated with greater numbers of CMBs in deep or infratentorial regions, independent of age, sex, cardiovascular risk factors, and white matter hyperintensities. NH and non-dipping were not associated with CMBs in deep or infratentorial regions, and there was no association between blood pressure and CMBs in lobar regions. Our results suggest that the presence of both OH and SH may be related to deep or infratentorial CMBs in patients with PD.

Dual-Sensitivity Multiple Sclerosis Lesion and CSF Segmentation for Multichannel 3T Brain MRI.

ABSTRACTBACKGROUND AND PURPOSEA pipeline for fully automated segmentation of 3T brain MRI scans in multiple sclerosis (MS) is presented. This 3T morphometry (3TM) pipeline provides indicators of MS disease progression from multichannel datasets with high‐resolution 3‐dimensional T1‐weighted, T2‐weighted, and fluid‐attenuated inversion‐recovery (FLAIR) contrast. 3TM segments white (WM) and gray matter (GM) and cerebrospinal fluid (CSF) to assess atrophy and provides WM lesion (WML) volume.METHODSTo address nonuniform distribution of noise/contrast (eg, posterior fossa in 3D‐FLAIR) of 3T magnetic resonance imaging, the method employs dual sensitivity (different sensitivities for lesion detection in predefined regions). We tested this approach by assigning different sensitivities to supratentorial and infratentorial regions, and validated the segmentation for accuracy against manual delineation, and for precision in scan‐rescans.RESULTSIntraclass correlation coefficients of .95, .91, and .86 were observed for WML and CSF segmentation accuracy and brain parenchymal fraction (BPF). Dual sensitivity significantly reduced infratentorial false‐positive WMLs, affording increases in global sensitivity without decreasing specificity. Scan‐rescan yielded coefficients of variation (COVs) of 8% and .4% for WMLs and BPF and COVs of .8%, 1%, and 2% for GM, WM, and CSF volumes. WML volume difference/precision was .49 ± .72 mL over a range of 0–24 mL. Correlation between BPF and age was r = .62 (P = .0004), and effect size for detecting brain atrophy was Cohen's d = 1.26 (standardized mean difference vs. healthy controls).CONCLUSIONSThis pipeline produces probability maps for brain lesions and tissue classes, facilitating expert review/correction and may provide high throughput, efficient characterization of MS in large datasets.