Showing papers in "Neuroradiology in 2013"
TL;DR: The 3D turbo field echo sequence can distinguish the PD group from the control group with high sensitivity and specificity, especially for early stage of PD.
Abstract: Introduction
Neuromelanin-sensitive MRI has been reported to be used in the diagnosis of Parkinson’s disease (PD), which results from loss of dopamine-producing cells in the substantia nigra pars compacta (SNc). In this study, we aimed to apply a 3D turbo field echo (TFE) sequence for neuromelanin-sensitive MRI and to evaluate the diagnostic performance of semi-automated method for measurement of SNc volume in patients with PD.
103 citations
TL;DR: ASL perfusion imaging is useful for differentiating PCNSLs from GBMs as well as DWI and FDG-PET in differentiating primary central nervous system lymphomas from glioblastoma multiformes.
Abstract: Our purpose was to evaluate the diagnostic performance of arterial spin labeling (ASL) perfusion imaging, diffusion-weighted imaging (DWI), and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in differentiating primary central nervous system lymphomas (PCNSLs) from glioblastoma multiformes (GBMs). Fifty-six patients including 19 with PCNSL and 37 with GBM were retrospectively studied. From the ASL data, an absolute tumor blood flow (aTBF) and a relative tumor blood flow (rTBF) were obtained within the enhancing portion of each tumor. In addition, the minimum apparent diffusion coefficient (ADCmin) and the maximum standard uptake value (SUVmax) were obtained from DWI and FDG-PET data, respectively. Each of the four parameters was compared between PCNSLs and GBMs using Kruskal–Wallis test. The performance in discriminating between PCNSLs and GBMs was evaluated using the receiver-operating characteristics analysis. Area-under-the-curve (AUC) values were compared among the four parameters using a nonparametric method. The aTBF, rTBF, and ADCmin were significantly higher in GBMs (mean aTBF ± SD = 91.6 ± 56.0 mL/100 g/min, mean rTBF ± SD = 2.61 ± 1.61, mean ADCmin ± SD = 0.78 ± 0.19 × 10−3 mm2/s) than in PCNSLs (mean aTBF ± SD = 37.3 ± 10.5 mL/100 g/min, mean rTBF ± SD = 1.24 ± 0.37, mean ADCmin ± SD = 0.61 ± 0.13 × 10−3 mm2/s) (p < 0.005, respectively). In addition, SUVmax was significantly lower in GBMs (mean ± SD = 13.1 ± 6.34) than in PCNSLs (mean ± SD = 22.5 ± 7.83) (p < 0.005). The AUC for aTBF (0.888) was higher than those for rTBF (0.810), ADCmin (0.768), and SUVmax (0.848), although their difference was not statistically significant. ASL perfusion imaging is useful for differentiating PCNSLs from GBMs as well as DWI and FDG-PET.
101 citations
TL;DR: Investigating whether the effect of scanner for cortex volumetry with atlas-based method is reduced using Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) normalization compared with standard normalization found it to be reduced with DARTEL normalization.
Abstract: This study aimed to investigate whether the effect of scanner for cortex volumetry with atlas-based method is reduced using Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) normalization compared with standard normalization. Three-dimensional T1-weighted magnetic resonance images (3D-T1WIs) of 21 healthy subjects were obtained and evaluated for effect of scanner in cortex volumetry. 3D-T1WIs of the 21 subjects were obtained with five MRI systems. Imaging of each subject was performed on each of five different MRI scanners. We used the Voxel-Based Morphometry 8 tool implemented in Statistical Parametric Mapping 8 and WFU PickAtlas software (Talairach brain atlas theory). The following software default settings were used as bilateral region-of-interest labels: “Frontal Lobe,” “Hippocampus,” “Occipital Lobe,” “Orbital Gyrus,” “Parietal Lobe,” “Putamen,” and “Temporal Lobe.” Effect of scanner for cortex volumetry using the atlas-based method was reduced with DARTEL normalization compared with standard normalization in Frontal Lobe, Occipital Lobe, Orbital Gyrus, Putamen, and Temporal Lobe; was the same in Hippocampus and Parietal Lobe; and showed no increase with DARTEL normalization for any region of interest (ROI). DARTEL normalization reduces the effect of scanner, which is a major problem in multicenter studies.
96 citations
TL;DR: CBV measurements using DCE-MRI may predict the status of contrast enhancing lesions and give results very similar to FDG-PET with regards to differentiation between tumor recurrence and radiation necrosis.
Abstract: To investigate if perfusion measured with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can be used to differentiate radiation necrosis from tumor recurrence in patients with high-grade glioma. The study was approved by the institutional review board and informed consent was obtained from all subjects. 19 patients were recruited following surgery and radiation therapy for glioma. Patients had contrast enhancing lesions, which during the standard MRI examination could not be exclusively determined as recurrence or radiation necrosis. DCE-MRI was used to measure cerebral blood volume (CBV), blood–brain barrier (BBB) permeability and cerebral blood flow (CBF). Subjects also underwent FDG-PET and lesions were classified as either metabolically active or inactive. Follow-up clinical MRI and lesion histology in case of additional tissue resection was used to determine whether lesions were regressing or progressing. Fourteen enhancing lesions could be classified as progressing (11) or regressing (three). An empirical threshold of 2.0 ml/100 g for CBV allowed detection of regressing lesions with a sensitivity of 100 % and specificity of 100 %. FDG-PET and DCE-MRI agreed in classification of tumor status in 13 out of the 16 cases where an FDG-PET classification was obtained. In two of the remaining three patients, MRI follow-up and histology was available and both indicated that the DCE-MRI answer was correct. CBV measurements using DCE-MRI may predict the status of contrast enhancing lesions and give results very similar to FDG-PET with regards to differentiation between tumor recurrence and radiation necrosis.
93 citations
TL;DR: A guide to the detection and clinical relevance of cerebral microbleeds in different conditions based on a comprehensive review of the literature and own findings in research and clinical practice is provided.
Abstract: Cerebral microbleeds have emerged as an important new imaging marker of cerebral small vessel disease With the development of MRI techniques that are exquisitely sensitive to paramagnetic blood products, such as T2*-weighted gradient-recalled echo and susceptibility-weighted sequences, microbleeds have been detected in ever-increasing numbers of patients in stroke and cognitive clinics, as well as in healthy older people and in a variety of other rarer diseases and syndromes Detection of cerebral microbleeds has clinical implications with respect to the diagnosis of the underlying small vessel disease, the safety of antithrombotic use, and the risk of symptomatic intracerebral haemorrhage, cognitive impairment and dementia This article provides a guide to the detection and clinical relevance of cerebral microbleeds in different conditions based on a comprehensive review of the literature and own findings in research and clinical practice
92 citations
TL;DR: Based on the direct correlation between postportem NmMRI and neuropathological findings, signal intensity in the SNc is closely related to the quantity of neuromelanin-containing neurons but is not influenced by iron deposition.
Abstract: Poster: "ECR 2013 / C-1246 / Correlation between pathology and neuromelanin MR imaging in Parkinson's disease and dementia with Lewy bodies" by: "S. Kitao1, E. Matsusue2, S. Fujii1, F. Miyoshi1, T. Kaminou1, T. Ogawa1; 1Yonago/JP, 2Tottori/JP"
90 citations
TL;DR: The IVIM-fitted post-processing of DWI-signal decay in human gliomas could show significantly different values of fractional perfusion-related volume and fast diffusion coefficient between low- and high-grade tumors, which might enable a noninvasive WHO grading in vivo.
Abstract: Introduction
The purpose of this study was to evaluate the feasibility of intravoxel incoherent motion (IVIM) imaging and its value in differentiating the histologic grade among human gliomas.
88 citations
TL;DR: The preliminary evaluation indicates that an initial high f may predict poor prognosis in HNSCC and in responders, a significant increase of all IVIM parameters after therapy was demonstrated.
Abstract: Using the intravoxel incoherent motion (IVIM) model, diffusion-related coefficient (D) and perfusion-related parameter (f) can be measured. Here, we used IVIM imaging to characterize squamous cell carcinomas of head and neck (HNSCC) and evaluated its application in follow-up after nonsurgical organ preserving therapy. Twenty-two patients with locally advanced HNSCC (clinical stage III to IVb) were examined before treatment using eight different b values (b = 0, 50, 100, 150, 200, 250, 700, 800 s/mm2). All patients were followed for at least 7.5 months after conclusion of therapy. In 16 of these patients, follow-up MRI was available. Using the IVIM approach, f and D were extracted using a bi-exponential fit. For comparison, ADC maps were calculated. The initial values of f before therapy were located between 5.9 % and 12.9 % (mean: 9.4 ± 2.4 %) except for two outliers (f = 17.9 % and 18.2 %). These two patients exclusively displayed poor initial treatment response. Overall, high initial f (13.1 ± 4.1 % vs. 9.1 ± 2.4 %) and ADC (1.17 ± 0.08 × 10−3 mm2/s vs. 0.98 ± 0.19 × 10−3 mm2/s) were associated with poor short term outcome (n = 6) after 7.5 months follow-up. D values before treatment were 0.98 × 10−3 ± 0.18 mm2/s and ADC values were 1.03 × 10−3 ± 0.18 mm2/s. At follow-up, in all primary responders, D (69 ± 52 %), f (65 ± 46 %), and ADC (68 ± 49%) increased. Our preliminary evaluation indicates that an initial high f may predict poor prognosis in HNSCC. In responders, a significant increase of all IVIM parameters after therapy was demonstrated.
82 citations
TL;DR: X-ray imaging technology using an image noise reduction algorithm and system settings provided approximately 60% radiation dose reduction in neuroangiography and interventional neuroradiology, without affecting the working habits of the physician.
Abstract: Introduction
The purpose of this study was to quantify the reduction in patient radiation dose by X-ray imaging technology using image noise reduction and system settings for neuroangiography and to assess its impact on the working habits of the physician.
82 citations
TL;DR: Absolute baseline ASPECT score reflects early symptomatic hemorrhage risk and functional outcome at 3 months, and further analyses are needed to determine its importance in the selection of patients for mechanical thrombectomy.
Abstract: The study attempts to identify notable factors predicting poor outcome, death, and intracranial hemorrhage in patients with acute ischemic stroke undergoing mechanical thrombectomy with stent retriever. These data could be useful to improve the selection of patients for thrombectomy. Patients with acute ischemic stroke treated with the Solitaire FR device were retrospectively analyzed from a prospectively collected database. We assessed the effect of selected demographic characteristics, clinical and imaging factors on poor outcome at 3 months (modified Rankin score 3–6), mortality at 3 months, and hemorrhage at day 1 (symptomatic and asymptomatic). From May 2010 to April 2012, 59 consecutive patients with an acute ischemic stroke underwent mechanical thrombectomy. At 3 months, 57.6 % of the patients were functionally independent (modified Rankin Scale 0–2) and mortality was 20.4 %. Multivariate analyses revealed that a thrombus length > 14 mm (p = 0.02; OR 7.55; 95 % CI 1.35–42.31) and longer endovascular procedure duration (p = 0.01; OR 1.04; 95 % CI 1.01–1.07) were independently associated with poor outcome. A higher baseline Alberta Stroke Program Early CT (ASPECT) score (p = 0.04; OR 0.79 per point; 95 % CI 0.63–0.99) and successful recanalization (p = 0.02; OR 0.07; 95 % CI 0.01–0.72) were independent predictors of good functional outcome. Baseline ASPECT score (p < 0.01; OR 0.65; 95 % CI 0.54–0.78) independently predicted symptomatic intracranial hemorrhage at day 1. Absolute baseline ASPECT score reflects early symptomatic hemorrhage risk and functional outcome at 3 months. Thrombus length measured on MRI play an important role on functional outcome at 3 months after thrombectomy. Further analyses are needed to determine its importance in the selection of patients for mechanical thrombectomy.
80 citations
TL;DR: These deep venous injuries appear to preserve the subplate zone, which is likely to be a significant element to consider in the perspective of the neurodevelopmental outcome.
Abstract: Introduction
Neurodevelopmental outcome in prematures who suffer from a neonatal brain injury depends on the lesion itself, and on how the lesion interferes with the still developing functional anatomy.
TL;DR: Endovascular reconstructive treatment of a ruptured BA using a flow-diverting device is a promising strategy that can be performed with acceptable clinical and good radiological results.
Abstract: Introduction
The current literature describing surgical and endovascular interventions in blister-like aneurysms (BAs) offers no clear consensus on the optimal treatment modality. The aim of this study was to assess the clinical and angiographic features of ruptured BAs treated endovascularly using predominantly flow-diversion strategy.
TL;DR: Individually, CBV measurement provides the greatest diagnostic performance for predicting glioma grade; however, the most accurate classification can be achieved by combining all of the imaging parameters.
Abstract: Accurate grading of cerebral glioma using conventional structural imaging techniques remains challenging due to the relatively poor sensitivity and specificity of these methods. The purpose of this study was to evaluate the relative sensitivity and specificity of structural magnetic resonance imaging and MR measurements of perfusion, diffusion, and whole-brain spectroscopic parameters for glioma grading. Fifty-six patients with radiologically suspected untreated glioma were studied with T1- and T2-weighted MR imaging, dynamic contrast-enhanced MR imaging, diffusion tensor imaging, and volumetric whole-brain MR spectroscopic imaging. Receiver-operating characteristic analysis was performed using the relative cerebral blood volume (rCBV), apparent diffusion coefficient, fractional anisotropy, and multiple spectroscopic parameters to determine optimum thresholds for tumor grading and to obtain the sensitivity, specificity, and positive and negative predictive values for identifying high-grade gliomas. Logistic regression was performed to analyze all the parameters together. The rCBV individually classified glioma as low and high grade with a sensitivity and specificity of 100 and 88 %, respectively, based on a threshold value of 3.34. On combining all parameters under consideration, the classification was achieved with 2 % error and sensitivity and specificity of 100 and 96 %, respectively. Individually, CBV measurement provides the greatest diagnostic performance for predicting glioma grade; however, the most accurate classification can be achieved by combining all of the imaging parameters.
TL;DR: rCBF in the CN and AD groups were significantly reduced in the subjects with the carriers of the epsilon4 allele, which is a risk factor for Alzheimer’s disease.
Abstract: The objective of this study was to evaluate the effect of apolipoprotein E (APOE) epsilon 4 allele on regional cerebral perfusion (rCBF) changes using arterial spin labeling (ASL) magnetic resonance imaging (MRI) in subjects who are carriers or noncarriers of this risk factor for Alzheimer disease (AD). Twenty-five subjects with AD, 25 with amnestic mild cognitive impairment (MCI) and 25 cognitively normal (CN) subjects underwent isotropic volumetric T1-weighted imaging and pulsed ASL MRI. All subjects were divided into carrier or noncarriers of the epsilon4 allele. Voxel-based statistical analyses were performed among groups on rCBF by ANOVA tests. In each subject group, we also evaluated the rCBF change between carrier and noncarrier groups. rCBF was significantly reduced in AD subjects compared to other subjects. In CN and AD subjects, rCBF in the carrier group was significantly reduced in several areas of the brain compared with that of the noncarrier group. In the carrier group, rCBF was significantly increased in the right parahippocampal gyrus, the bilateral cingulate gyri and the right posterior cingulate on the MCI group in addition to the right superior frontal gyrus in the AD group. rCBF in the CN and AD groups were significantly reduced in the subjects with the carriers of the epsilon4 allele, which is a risk factor for Alzheimer’s disease. In addition, rCBF in the MCI group was significantly increased in subjects who were carriers. Therefore, rCBF can be used as a biomarker to show disease progression in areas of the brain of MCI subjects.
TL;DR: This review tries to discuss when best to perform cranial ultrasound and MRI, and the additional information each technique may provide.
Abstract: Neuroimaging of preterm infants has become part of routine clinical care, but the question is often raised on how often cranial ultrasound should be done and whether every high risk preterm infant should at least have one MRI during the neonatal period. An increasing number of centres perform an MRI either at discharge or around term equivalent age, and a few centres have access to a magnet in or adjacent to the neonatal intensive care unit and are doing sequential MRIs. In this review, we try to discuss when best to perform these two neuroimaging techniques and the additional information each technique may provide.
TL;DR: 3D-BB-T1WI is a promising method to evaluate intramural haematoma in patients with suspected intracranial VAD and was considered the most consistent sequence in representing the extent and morphology of the lesion in 14 cases.
Abstract: We investigated the efficacy of three-dimensional black blood T1-weighted imaging (3D-BB-T1WI) using a variable refocusing flip angle turbo spin-echo sequence in the diagnosis of intracranial vertebral artery dissection (VAD). Sixteen consecutive patients diagnosed with intracranial VAD underwent magnetic resonance imaging that included 3D time-of-flight-MRA, axial spin-echo T1-weighted images (SE-T1WI) and oblique coronal 3D-BB-T1WI sequences. The visualization, morphology and extent of intramural haematomas were assessed and compared among the sequences. Results obtained by digital subtraction angiography (DSA), 3D-angiography and/or 3D-CT angiography (CTA) were used as standards of reference. 3D-BB-T1WI revealed intramural haematomas in all cases, whereas SE-T1WI and magnetic resonance angiography (MRA) failed to reveal a haematoma in one case and three cases, respectively. The mean visualization grading score for the intramural haematoma was the highest for 3D-BB-T1WI, and there was a statistically significant difference among the sequences (p < 0.001). At least a portion of the intramural haematoma was distinguishable from the lumen on 3D-BB-T1WI, whereas the haematomas were entirely indistinguishable from intraluminal signals on MRA in two cases (12.5 %) and on SE-T1WI in one case (6.3 %). 3D-BB-T1WI revealed the characteristic crescent shape of the intramural haematoma in 14 cases (87.5 %), whereas SE-T1WI and MRA revealed a crescent shape in only 7 cases (43.8 %) and 8 cases (50 %), respectively. In a consensus reading, 3D-BB-T1WI was considered the most consistent sequence in representing the extent and morphology of the lesion in 14 cases (87.5 %), compared to DSA and CTA. 3D-BB-T1WI is a promising method to evaluate intramural haematoma in patients with suspected intracranial VAD.
TL;DR: FDG-PET is an accurate noninvasive method in lateralizing the epileptogenic focus in temporal lobe epilepsy, especially in patients with normal or equivocal MRIs, or non-lateralized EEG monitoring.
Abstract: Introduction
We studied the contribution of interictal FDG-PET ([18 F] fluorodeoxyglucose-positron emission tomography) in epileptic focus identification in temporal lobe epilepsy patients with positive, equivocal and negative magnetic resonance imaging (MRI).
TL;DR: Fluorodeoxyglucose-PET performed at the time of initial referral for parkinsonism is useful for the differential diagnosis of IPD, PSP, MSA, and CBS.
Abstract: Positron emission tomography (PET) imaging with F-18 fluorodeoxyglucose (FDG) has been used to identify characteristic patterns of regional glucose metabolism in patients with idiopathic Parkinson's disease (IPD) and the atypical parkinsonian syndromes of progressive supranuclear palsy (PSP), multiple system atrophy (MSA), and corticobasal syndrome (CBS). We undertook this study to assess the utility of fluorodeoxyglucose-PET in the differential diagnosis of individual patients with clinical parkinsonism. “Visual” and “computer-supported” reading of the fluorodeoxyglucose-PET scans were used for image interpretation and compared with each other. One hundred thirty-six parkinsonian patients were referred from movement disorder clinics in specialty neurology centers for the fluorodeoxyglucose-PET study. Imaging-based diagnosis was obtained by visual assessment of individual scans by a PET physician blinded to the clinical diagnosis and also by computer-assisted interpretation using statistical parametric mapping (SPM) analysis. The results were compared with a 2-year follow-up clinical assessment made by a movement disorder specialist. Concordance of visual evaluation of fluorodeoxyglucose-PET with clinical diagnosis was achieved in 91.7 % of patients scanned, 97.6 % IPD, 80 % MSA, 76.6 % PSP, and 100 % CBS. Blinded computer assessment using SPM was concordant with the clinical diagnosis in 91 % of cases evaluated (90.4 % IPD, 80 % MSA, 93.3 % PSP, and 100 % CBS). Fluorodeoxyglucose-PET performed at the time of initial referral for parkinsonism is useful for the differential diagnosis of IPD, PSP, MSA, and CBS. Computer-assisted methods can be used for objective evaluation especially when expert readers are not available.
TL;DR: Volumetric assessment in WB-CTP is reliable and reproducible and might serve for a more accurate assessment of stroke outcome prognosis and definition of flow-volume mismatch.
Abstract: The aim of this study was to examine reliability and reproducibility of volumetric perfusion deficit assessment in patients with acute ischemic stroke who underwent recently introduced whole-brain CT perfusion (WB-CTP). Twenty-five consecutive patients underwent 128-row WB-CTP with extended scan coverage of 100 mm in the z-axis using adaptive spiral scanning technique. Volumetric analysis of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), time to peak (TTP), and time to drain (TTD) was performed twice by two blinded and experienced readers using OsiriX V.4.0 imaging software. Interreader agreement and intrareader agreement were assessed by intraclass correlation coefficients (ICCs) and Bland–Altman Analysis. Interreader agreement was highest for TTD (ICC 0.982), followed by MTT (0.976), CBF (0.955), CBV (0.933), and TTP (0.865). Intrareader agreement was also highest for TTD (ICC 0.993), followed by MTT (0.988), CBF (0.981), CBV (9.953), and TTP (0.927). The perfusion deficits showed the highest absolute volumes in the time-related parametric maps TTD (mean volume 121.4 ml), TTP (120.0 ml), and MTT (112.6 ml) and did not differ significantly within this group (each with p > 0.05). In comparison to time-related maps, the mean CBF perfusion deficit volume was significantly smaller (92.1 ml, each with p < 0.05). The mean CBV lesion size was 23.4 ml. Volumetric assessment in WB-CTP is reliable and reproducible. It might serve for a more accurate assessment of stroke outcome prognosis and definition of flow-volume mismatch. Time to drain showed the highest agreement and therefore might be an interesting parameter to define tissue at risk.
TL;DR: 4D PC MRI appears as valid alternative for intracranial velocity measurement consistent with previous reference standards, foremost with TCD.
Abstract: Introduction
4D phase contrast MR imaging (4D PC MRI) has been introduced for spatiotemporal evaluation of intracranial hemodynamics in various cerebrovascular diseases. However, it still lacks validation with standards of reference. Our goal was to compare blood flow quantification derived from 4D PC MRI with transcranial ultrasound and 2D PC MRI.
TL;DR: Anomalous origin and anomalous entry level into the TF correlated strongly, and recognition and reporting of these variations is important in interpreting CT angiography to prevent complications during surgery of the aortic arch or lower neck.
Abstract: The origin of the vertebral artery (VA) varies, though most VAs enter the transverse foramen (TF) of the sixth cervical vertebra. On computed tomography (CT) angiographic images, we evaluated the prevalence of variations of both VA origin and its level of entry into the TF. We retrospectively reviewed CT angiographic images of 2,287 patients obtained using either of two 64-slice multidetector CT scanners. All patients were Japanese and underwent scanning from the aortic arch to the intracranial region; most had or were suspected of having cerebrovascular diseases. The left VA (LVA) arose from the aorta between the left common carotid artery and left subclavian artery in 94 patients (4.1 %) and in other variations in 44 patients (1.9 %). The right VA (RVA) arose from the extreme proximal segment of the right subclavian artery in 72 patients (3.1 %) and in other variations in 14 patients (0.6 %). The LVA entered the sixth TF in 2,127 patients (93.0 %), and the RVA entered the sixth TF in 2,146 patients (93.8 %). Anomalous origin and anomalous entry level into the TF correlated strongly. The total prevalence of variation in the origin of the LVA was 6.0 % and of the RVA, 3.8 %. The total prevalence of variation in entry level into the TF was 7.0 % for the LVA and 6.2 % for the RVA. Recognition and reporting of these variations is important in interpreting CT angiography to prevent complications during surgery of the aortic arch or lower neck.
TL;DR: MRI abnormalities in neurosyphilis are protean and mimic of many other neurological disorders and thus require a high index of suspicion to reduce diagnostic omissions.
Abstract: Introduction
The clinical and MR imaging features of neurosyphilis are highly varied. In this study, we describe the spectrum of the imaging findings in patients with neurosyphilis.
TL;DR: SWI at 7 T is a useful method for detecting intratumoral vascular architecture of brain gliomas and that SWI pattern quantification by means of fractal dimension offers a potential objective morphometric image biomarker of tumor grade is confirmed.
Abstract: Susceptibility-weighted imaging (SWI) with high- and ultra-high-field magnetic resonance is a very helpful tool for evaluating brain gliomas and intratumoral structures, including microvasculature. Here, we test whether objective quantification of intratumoral SWI patterns by applying fractal analysis can offer reliable indexes capable of differentiating glial tumor grades. Thirty-six patients affected by brain gliomas (grades II–IV, according to the WHO classification system) underwent MRI at 7 T using a SWI protocol. All images were collected and analyzed by applying a computer-aided fractal image analysis, which applies the fractal dimension as a measure of geometrical complexity of intratumoral SWI patterns. The results were subsequently statistically correlated to the histopathological tumor grade. The mean value of the fractal dimension of the intratumoral SWI patterns was 2.086 ± 0.413. We found a trend of higher fractal dimension values in groups of higher histologic grade. The values ranged from a mean value of 1.682 ± 0.278 for grade II gliomas to 2.247 ± 0.358 for grade IV gliomas (p = 0.013); there was an overall statistically significant difference between histopathological groups. The present study confirms that SWI at 7 T is a useful method for detecting intratumoral vascular architecture of brain gliomas and that SWI pattern quantification by means of fractal dimension offers a potential objective morphometric image biomarker of tumor grade.
TL;DR: DTI parameters fractional anisotropy and RD are altered in the optic chiasm and radiations of glaucoma patients and could serve as potential noninvasive markers of disease severity.
Abstract: Introduction
Glaucoma is the second leading cause of blindness worldwide The purpose of this study is to identify areas of neurodegeneration in glaucoma utilizing 3 T magnetic resonance (MR) diffusion tensor imaging (DTI) parameters with whole-brain voxel-based analysis (VBA) and determine whether these parameters correlate with disease severity
TL;DR: d-MRI is an effective tool for investigating preterm white matter injury and has the potential to be a biomarker of subsequent outcome and to evaluate efficacy of clinical interventions in this population of survivors of preterm birth.
Abstract: Inroduction
White matter injury and abnormal maturation are thought to be major contributors to the neurodevelopmental disabilities observed in children and adolescents who were born preterm. Early detection of abnormal white matter maturation is important in the design of preventive, protective, and rehabilitative strategies for the management of the preterm infant. Diffusion-weighted magnetic resonance imaging (d-MRI) has become a valuable tool in assessing white matter maturation and injury in survivors of preterm birth. In this review, we aim to (1) describe the basic concepts of d-MRI; (2) evaluate the methods that are currently used to analyse d-MRI; (3) discuss neuroimaging correlates of preterm brain injury observed at term corrected age; during infancy, adolescence and in early adulthood; and (4) explore the relationship between d-MRI measures and subsequent neurodevelopmental performance.
TL;DR: Different cortical reorganization patterns (increases in or focusing of recruitment to the cSMC region) exist in chronic stroke patients after interventions, and patients may choose efficient patterns to improve their motor function.
Abstract: Despite its clinical efficacy, few studies have examined the neural mechanisms of motor imagery training (MIT) in stroke. Our objective was to find the cortical reorganization patterns after MIT in chronic stroke patients. Twenty stroke patients with severe motor deficits were randomly assigned to the MIT or conventional rehabilitation therapy (CRT) group, but two lost in the follow-up. All 18 patients received CRT 5 days/week for 4 weeks. Nine subjects in the MIT group received 30-min MIT 5 days/week for 4 weeks. Before and after the interventions, the upper limb section of the Fugl–Meyer Scale (FM-UL) was blindly evaluated, and functional magnetic resonance imaging was administered while the patients executed a passive fist clutch task. Two cortical reorganization patterns were found. One pattern consisted of the growth in activation in the contralateral sensorimotor cortex (cSMC) for most patients (six in the MIT group, five in the CRT group), and the other consisted of focusing of the activation in the cSMC with increasing of the laterality index of the SMC for a small portion of patients (three in the MIT group, one in the CRT group). When we applied correlation analyses to the variables of relative ΔcSMC and ΔFM-UL in the 11 patients who experienced the first pattern, a positive relationship was detected. Our results indicate that different cortical reorganization patterns (increases in or focusing of recruitment to the cSMC region) exist in chronic stroke patients after interventions, and patients may choose efficient patterns to improve their motor function.
TL;DR: The aim is to present the range of associated arterial anomalies or syndromes, as well as pathologies that are associated with a PTA: aneurysms, trigeminal cavernous fistulas, and trigemINAL nerve compression, and their management.
Abstract: The persistent trigeminal artery (PTA) is the most common and most cephalad-located embryological anastomosis between the developing carotid artery and vertebrobasilar system to persist into adulthood. As such, it is frequently reported as an incidental finding in computed tomography angiography and magnetic resonance angiography studies. Here, we review the embryology, anatomy, and angiographic imaging findings, including important variants of this commonly encountered cerebrovascular anomaly (reported incidence of PTA/PTA variants ranges from 0.1% to 0.76%). Further, the aim is to present the range of associated arterial anomalies or syndromes, as well as pathologies that are associated with a PTA: aneurysms, trigeminal cavernous fistulas, and trigeminal nerve compression. Besides summarizing the risks and clinical presentation of such pathologies, their management is discussed with endovascular strategies mostly being the primary choice for aneurysms and trigeminal cavernous fistulas. Symptomatic trigeminal nerve compression can be treated with microvascular decompression surgery. As an illustrative example, a case of a trigeminal cavernous fistula on a PTA variant is included, mainly to emphasize the importance of understanding the variant anatomy for treatment planning in such pathologies. Finally, recommendations on how to manage patients with PTA-associated vascular pathologies are advanced.
TL;DR: The results of this study have proven that endovascular internal trapping is a stable and durable treatment for closure of VADs.
Abstract: Introduction
Previous reports have suggested that endovascular parent artery occlusion is an effective and safe procedure for the treatment of vertebral artery dissection (VAD). However, the results of long-term outcomes are still unclear. This study reviewed the clinical and imaging outcomes of patients with VAD treated by endovascular internal trapping.
TL;DR: Treatment with stents and a flow diverter led to reductions in aneurysmal fluid dynamic activity for both idealized and patient-specific models, and telescoping high-porosity stents may represent a viable treatment alternative in situations where the use of a PED is not an option.
Abstract: Introduction
Flow diverting devices and stents can be used to treat cerebral aneurysms too difficult to treat with coiling or craniotomy and clipping. However, the hemodynamic effects of these devices have not been studied in depth. The objective of this study was to quantify and understand the fluid dynamic changes that occur within bifurcating aneurysms when treated with different devices and configurations.
TL;DR: DTI measurement could detect abnormality of the optic nerve in patients with glaucoma and may serve as a biomarker of disease severity.
Abstract: Introduction
To investigate the association of quantitative 3-T diffusion tensor imaging (DTI) with retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT) and clinical severity in detecting optic nerve degeneration in patients with primary closed-angle glaucoma.