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https://www.readbyqxmd.com/read/28101675/operative-planning-aid-for-optimal-endoscopic-third-ventriculostomy-entry-points-in-pediatric-cases
#1
Zsolt Zador, David J Coope, Abteen Mostofi, Ian D Kamaly-Asl
OBJECT: Endoscopic third ventriculostomy (ETV) uses anatomical spaces of the ventricular system to reach the third ventricle floor and create an alternative pathway for cerebrospinal fluid flow. Optimal ETV trajectories have been previously proposed in the literature, designed to grant access to the third ventricle floor without a displacement of eloquent periventricular structures. However, in hydrocephalus, there is a significant variability to the configuration of the ventricular system, implying that the optimal ETV trajectory and cranial entry point needs to be planned on a case-by-case basis...
January 18, 2017: Child's Nervous System: ChNS: Official Journal of the International Society for Pediatric Neurosurgery
https://www.readbyqxmd.com/read/28095387/mri-of-cerebellar-infarction
#2
Laurens J L De Cocker, Karl-Olof Lövblad, Jeroen Hendrikse
BACKGROUND: MRI is the imaging modality of choice for diagnosing brain infarction. Because of few or atypical clinical symptoms and a relatively low sensitivity of CT scans, many cerebellar infarctions may be detected only with MRI. With adequate recognition of cerebellar infarction on MRI and prompt initiation or optimisation of preventive therapeutic measures, more dramatic strokes may be avoided in selected cases. SUMMARY: We first briefly review the clinical presentation of cerebellar infarctions, followed by a short refresher on cerebellar anatomy and pathophysiological mechanisms of cerebellar infarcts...
January 18, 2017: European Neurology
https://www.readbyqxmd.com/read/28092848/the-initial-use-of-arterial-spin-labeling-perfusion-and-diffusion-weighted-magnetic-resonance-images-in-the-diagnosis-of-nonconvulsive-partial-status-epileptics
#3
Takafumi Shimogawa, Takato Morioka, Tetsuro Sayama, Sei Haga, Yuka Kanazawa, Kei Murao, Shuji Arakawa, Ayumi Sakata, Koji Iihara
BACKGROUND: In the diagnosis of nonconvulsive status epilepticus (NCSE), capture of ongoing ictal electroencephalographic (EEG) findings is the gold standard; however, this is practically difficult without continuous EEG monitoring facilities. Magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI) and perfusion MRI with arterial spin labeling (ASL), have been applied mainly in emergency situations. Recent reports have described that ictal MRI findings, including ictal hyperperfusion on ASL and cortical hyperintensity of cytotoxic edema on DWI, can be obtained from epileptically activated cortex...
December 21, 2016: Epilepsy Research
https://www.readbyqxmd.com/read/28092411/measurement-of-arterial-transit-time-and-renal-blood-flow-using-pseudocontinuous-asl-mri-with-multiple-post-labeling-delays-feasibility-reproducibility-and-variation
#4
Dong Won Kim, Woo Hyun Shim, Seong Kuk Yoon, Jong Yeong Oh, Jeong Kon Kim, Hoesu Jung, Tsuyoshi Matsuda, Dongeun Kim
PURPOSE: To evaluate the feasibility, reproducibility, and variation of renal perfusion and arterial transit time (ATT) using pseudocontinuous arterial spin labeling magnetic resonance imaging (PCASL MRI) in healthy volunteers. MATERIALS AND METHODS: PCASL MRI at 3T was performed in 25 healthy volunteers on two different occasions. The ATT and ATT-corrected renal blood flow (ATT-cRBF) were calculated at four different post-labeling delay points (0.5, 1.0, 1.5, and 2...
January 16, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28063376/a-comprehensive-non-invasive-framework-for-diagnosing-prostate-cancer
#5
Islam Reda, Ahmed Shalaby, Mohammed Elmogy, Ahmed Abou Elfotouh, Fahmi Khalifa, Mohamed Abou El-Ghar, Ehsan Hosseini-Asl, Georgy Gimel'farb, Naoufel Werghi, Ayman El-Baz
Early detection of prostate cancer increases chances of patients' survival. Our automated non-invasive system for computer-aided diagnosis (CAD) of prostate cancer segments the prostate on diffusion-weighted magnetic resonance images (DW-MRI) acquired at different b-values, estimates its apparent diffusion coefficients (ADC), and classifies their descriptors - empirical cumulative distribution functions (CDF) - with a trained deep learning network. To segment the prostate, an evolving geometric (level-set-based) deformable model is guided by a speed function depending on intensity attributes extracted from the DW-MRI with nonnegative matrix factorization (NMF)...
December 23, 2016: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28048262/su-g-iep1-07-inaccuracy-of-lesion-blood-flow-quantification-related-to-the-proton-density-reference-image-in-arterial-spin-labeling-mri-of-brain-tumors
#6
M Jen, J Johnson, P Hou, H Liu
PURPOSE: Cerebral blood flow quantification in arterial spin labeling (ASL) MRI requires an estimate of the equilibrium magnetization of blood, which is often obtained by a set of proton density (PD) reference image. Normally, a constant blood-brain partition coefficient is assumed across the brain. However, this assumption may not be valid for brain lesions. This study aimed to evaluate the impact of lesion-related PD variations on ASL quantification in patients with brain tumors. METHODS: MR images for posttreatment evaluation of 42 patients with brain tumors were retrospectively analyzed...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046971/th-cd-206-01-expectation-maximization-algorithm-based-tissue-mixture-quantification-for-perfusion-mri
#7
H Han, Z Liang, L Li, L Xing
PURPOSE: To investigate the feasibility of estimating the tissue mixture perfusions and quantifying cerebral blood flow change in arterial spin labeled (ASL) perfusion MR images. METHODS: The proposed perfusion MR image analysis framework consists of 5 steps: (1) Inhomogeneity correction was performed on the T1- and T2-weighted images, which are available for each studied perfusion MR dataset. (2) We used the publicly available FSL toolbox to strip off the non-brain structures from the T1- and T2-weighted MR images...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28045051/randomized-trial-on-the-effects-of-a-combined-physical-cognitive-training-in-aged-mci-subjects-the-train-the-brain-study
#8
(no author information available yet)
Age-related cognitive impairment and dementia are an increasing societal burden. Epidemiological studies indicate that lifestyle factors, e.g. physical, cognitive and social activities, correlate with reduced dementia risk; moreover, positive effects on cognition of physical/cognitive training have been found in cognitively unimpaired elders. Less is known about effectiveness and action mechanisms of physical/cognitive training in elders already suffering from Mild Cognitive Impairment (MCI), a population at high risk for dementia...
January 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/27988320/heterogeneous-increases-of-regional-cerebral-blood-flow-during-preterm-brain-development-preliminary-assessment-with-pseudo-continuous-arterial-spin-labeled-perfusion-mri
#9
Minhui Ouyang, Peiying Liu, Tina Jeon, Lina Chalak, Roy Heyne, Nancy K Rollins, Daniel J Licht, John A Detre, Timothy P L Roberts, Hanzhang Lu, Hao Huang
The human brain develops rapidly during 32-45 postmenstrual weeks (PMW), a critical stage characterized by dramatic increases of metabolic demand. The increasing metabolic demand can be inferred through measurements of regional cerebral blood flow (CBF), which might be coupled to regional metabolism in preterm brains. Arterial spin labeled (ASL) perfusion MRI is one of the few viable approaches for imaging regional CBF of preterm brains, but must be optimized for the extremely slow blood velocity unique in preterm brains...
December 14, 2016: NeuroImage
https://www.readbyqxmd.com/read/27986990/multiparametric-computer-aided-differential-diagnosis-of-alzheimer-s-disease-and-frontotemporal-dementia-using-structural-and-advanced-mri
#10
Esther E Bron, Marion Smits, Janne M Papma, Rebecca M E Steketee, Rozanna Meijboom, Marius de Groot, John C van Swieten, Wiro J Niessen, Stefan Klein
OBJECTIVES: To investigate the added diagnostic value of arterial spin labelling (ASL) and diffusion tensor imaging (DTI) to structural MRI for computer-aided classification of Alzheimer's disease (AD), frontotemporal dementia (FTD), and controls. METHODS: This retrospective study used MRI data from 24 early-onset AD and 33 early-onset FTD patients and 34 controls (CN). Classification was based on voxel-wise feature maps derived from structural MRI, ASL, and DTI...
December 16, 2016: European Radiology
https://www.readbyqxmd.com/read/27942478/arterial-spin-labeling-perfusion-magnetic-resonance-imaging-of-non-human-primates
#11
Xiaodong Zhang, Chun-Xia Li
Non-human primates (NHPs) resemble most aspects of humans in brain physiology and anatomy and are excellent animal models for translational research in neuroscience, biomedical research and pharmaceutical development. Cerebral blood flow (CBF) offers essential physiological information of the brain to examine the abnormal functionality in NHP models with cerebral vascular diseases and neurological disorders or dementia. Arterial spin labeling (ASL) perfusion MRI techniques allow for high temporal and spatial CBF measurement and are intensively used in studies of animals and humans...
October 2016: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/27924360/perfusion-imaging-of-brain-gliomas-using-arterial-spin-labeling-correlation-with-histopathological-vascular-density-in-mri-guided-biopsies
#12
Di Ningning, Pang Haopeng, Dang Xuefei, Cheng Wenna, Ren Yan, Wu Jingsong, Yao Chengjun, Yao Zhenwei, Feng Xiaoyuan
INTRODUCTION: This study was designed to determine if cerebral blood flow (CBF) derived from arterial spin labeling (ASL) perfusion imaging could be used to quantitatively evaluate the microvascular density (MVD) of brain gliomas on a "point-to-point" basis by matching CBF areas and surgical biopsy sites as accurate as possible. METHODS: The study enrolled 47 patients with treatment-naive brain gliomas who underwent preoperative ASL, 3D T1-weighted imaging with gadolinium contrast enhancement (3D T1C+), and T2 fluid acquisition of inversion recovery (T2FLAIR) sequences before stereotactic surgery...
December 6, 2016: Neuroradiology
https://www.readbyqxmd.com/read/27913820/cerebral-blood-flow-transit-time-and-apparent-diffusion-coefficient-in-moyamoya-disease-before-and-after-acetazolamide
#13
Christian Federau, Soren Christensen, Zungho Zun, Sun-Won Park, Wendy Ni, Michael Moseley, Greg Zaharchuk
INTRODUCTION: The goal of this study was to assess the changes in arterial spin labeling (ASL) cerebral blood flow (CBF) and arterial transit time (ATT), and in apparent diffusion coefficient (ADC), before and after an acetazolamide challenge in moyamoya patients, as function of arterial stenosis severity. METHODS: Pre-operative patients diagnosed with moyamoya disease who could undergo MRI at 3.0T were recruited for this study. A multi-delay pseudo-continuous ASL and a diffusion-weighted sequence were acquired before and 15 min after acetazolamide injection...
December 2, 2016: Neuroradiology
https://www.readbyqxmd.com/read/27911758/multimodal-imaging-for-dreadd-expressing-neurons-in-living-brain-and-their-application-to-implantation-of-ipsc-derived-neural-progenitors
#14
Bin Ji, Hiroyuki Kaneko, Takafumi Minamimoto, Haruhisa Inoue, Hiroki Takeuchi, Katsushi Kumata, Ming-Rong Zhang, Ichio Aoki, Chie Seki, Maiko Ono, Masaki Tokunaga, Satoshi Tsukamoto, Koji Tanabe, Ryong-Moon Shin, Takeharu Minamihisamatsu, Seiji Kito, Barry J Richmond, Tetsuya Suhara, Makoto Higuchi
: Chemogenetic manipulation of neuronal activities has been enabled by a designer receptor (designer receptor exclusively activated by designer drugs, DREADD) that is activated exclusively by clozapine-N-oxide (CNO). Here, we applied CNO as a functional reporter probe to positron emission tomography (PET) of DREADD in living brains. Mutant human M4 DREADD (hM4Di) expressed in transgenic (Tg) mouse neurons was visualized by PET with microdose [(11)C]CNO. Deactivation of DREADD-expressing neurons in these mice by nonradioactive CNO at a pharmacological dose could also be captured by arterial spin labeling MRI (ASL-MRI)...
November 9, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27908711/cerebral-blood-flow-measured-by-arterial-spin-labeling-mri-at-resting-state-in-normal-aging-and-alzheimer-s-disease
#15
REVIEW
Nan Zhang, Marc L Gordon, Terry E Goldberg
Arterial spin labeling (ASL) magnetic resonance imaging uses arterial blood water as an endogenous tracer to measure cerebral blood flow (CBF). In this review, based on ASL studies in the resting state, we discuss state-of-the-art technical and data processing improvements in ASL, and ASL CBF changes in normal aging, mild cognitive impairment (MCI), Alzheimer's disease (AD), and other types of dementia. We propose that vascular and AD risk factors should be considered when evaluating CBF changes in aging, and that other validated biomarkers should be used as inclusion criteria or covariates when evaluating CBF changes in MCI and AD...
January 2017: Neuroscience and Biobehavioral Reviews
https://www.readbyqxmd.com/read/27898185/perfusion-has-no-effect-on-the-in-vivo-cest-effect-from-cr-crcest-in-skeletal-muscle
#16
Feliks Kogan, Randall B Stafford, Erin K Englund, Garry E Gold, Hari Hariharan, John A Detre, Ravinder Reddy
Creatine, a key component of muscle energy metabolism, exhibits a chemical exchange saturation transfer (CEST) effect between its amine group and bulk water, which has been exploited to spatially and temporally map creatine changes in skeletal muscle before and after exercise. In addition, exercise leads to an increase in muscle perfusion. In this work, we determined the effects of perfused blood on the CEST effects from creatine in skeletal muscle. Experiments were performed on healthy human subjects (n = 5) on a whole-body Siemens 7T magnetic resonance imaging (MRI) scanner with a 28-channel radiofrequency (RF) coil...
January 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/27876537/artificial-neural-networks-approach-to-pharmacokinetic-model-selection-in-dce-mri-studies
#17
Mohammad-Reza Mohammadian-Behbahani, Ali-Reza Kamali-Asl
PURPOSE: In pharmacokinetic analysis of Dynamic Contrast Enhanced MRI data, a descriptive physiological model should be selected properly out of a set of candidate models. Classical techniques suggested for this purpose suffer from issues like computation time and general fitting problems. This article proposes an approach based on Artificial Neural Networks (ANNs) for solving these problems. METHODS: A set of three physiologically and mathematically nested models generated from the Tofts model were assumed: Model I, II and III...
December 2016: Physica Medica: PM
https://www.readbyqxmd.com/read/27867814/the-assessment-of-myometrium-perfusion-in-patients-with-uterine-fibroid-by-arterial-spin-labeling-mri
#18
Nozomi Takahashi, Osamu Yoshino, Osamu Hiraike, Eriko Maeda, Masanobu Nakamura, Masaaki Hori, Miyuki Harada, Kaori Koga, Shigeru Saito, Tomoyuki Fujii, Yutaka Osuga
BACKGROUND: It has been suggested that an inadequate blood supply caused by uterine fibroids may lead to decreasing fertility. Therefore, a quantitative evaluation of blood flow in the uterus might be a good tool for infertility treatments. For the first step, the ability to perform arterial spin labeling (ASL)-MRI in pelvic organs was examined by measuring blood flow in the uterine muscle layer. RESULTS: Three normal volunteer women, seven patients with one uterine fibroid and four patients treated with GnRH analogue for uterine fibroids, were enrolled in this study...
2016: SpringerPlus
https://www.readbyqxmd.com/read/27867170/evaluation-of-appropriate-readout-sequence-for-renal-mri-perfusion-using-astar-asl-technique
#19
Kyoko Takakura, Aki Kido, Koji Fujimoto, Kayo Kiguchi, Yasutaka Fushimi, Naotaka Sakashita, Tokunori Kimura, Kaori Togashi
The aim of this study was to compare true-steady state free precession (True-SSFP) with fast field echo (FFE) as readout imaging sequences for renal arterial spin labeling (ASL), and to optimize the imaging condition. Renal ASL perfusion images were acquired using signal targeting with alternated radio frequency using asymmetric inversion slab (ASTAR) technique with respiratory triggering at 3T MRI system, using either 3D True-SSFP or FFE as the readout sequence. Inversion time (TI) varied from 800 to 2400 ms...
2016: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/27864008/renal-plasma-flow-rpf-measured-with-multiple-inversion-time-arterial-spin-labeling-asl-and-tracer-kinetic-analysis-validation-against-a-dynamic-contrast-enhancement-method
#20
Christopher C Conlin, Niels Oesingmann, Bradley Bolster, Yufeng Huang, Vivian S Lee, Jeff L Zhang
PURPOSE: To propose and validate a method for accurately quantifying renal plasma flow (RPF) with arterial spin labeling (ASL). MATERIALS AND METHODS: The proposed method employs a tracer-kinetic approach and derives perfusion from the slope of the ASL difference signal sampled at multiple inversion-times (TIs). To validate the method's accuracy, we performed a HIPAA-compliant and IRB-approved study with 15 subjects (9 male, 6 female; age range 24-73) to compare RPF estimates obtained from ASL to those from a more established dynamic contrast-enhanced (DCE) MRI method...
November 15, 2016: Magnetic Resonance Imaging
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