scholarly journals Multiplatform genomic profiling and magnetic resonance imaging identify mechanisms underlying intratumor heterogeneity in meningioma

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Stephen T. Magill ◽  
Harish N. Vasudevan ◽  
Kyounghee Seo ◽  
Javier E. Villanueva-Meyer ◽  
Abrar Choudhury ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Images ◽  
Molecular Therapy ◽  
Intratumor Heterogeneity ◽  
Marker Genes ◽  
Proliferating Cells ◽  
Developmental Gene Expression ◽  
High Apparent Diffusion Coefficient ◽  
Apparent Diffusion ◽  
Human Meningiomas

Abstract Meningiomas are the most common primary intracranial tumors, but the molecular drivers of meningioma tumorigenesis are poorly understood. We hypothesized that investigating intratumor heterogeneity in meningiomas would elucidate biologic drivers and reveal new targets for molecular therapy. To test this hypothesis, here we perform multiplatform molecular profiling of 86 spatially-distinct samples from 13 human meningiomas. Our data reveal that regional alterations in chromosome structure underlie clonal transcriptomic, epigenomic, and histopathologic signatures in meningioma. Stereotactic co-registration of sample coordinates to preoperative magnetic resonance images further suggest that high apparent diffusion coefficient (ADC) distinguishes meningioma regions with proliferating cells enriched for developmental gene expression programs. To understand the function of these genes in meningioma, we develop a human cerebral organoid model of meningioma and validate the high ADC marker genes CDH2 and PTPRZ1 as potential targets for meningioma therapy using live imaging, single cell RNA sequencing, CRISPR interference, and pharmacology.

Estimation of ultrasonic scattering attenuation in partially frozen brines using magnetic resonance images

Geophysics ◽  
2011 ◽  
Vol 76 (1) ◽  
pp. T13-T25 ◽  
Author(s):  
Jun Matsushima ◽  
Makoto Suzuki ◽  
Yoshibumi Kato ◽  
Shuichi Rokugawa
Keyword(s):  
Magnetic Resonance ◽  
Seismic Waves ◽  
Synthetic Data ◽  
Magnetic Resonance Images ◽  
Seismic Attenuation ◽  
Ultrasonic Scattering ◽  
Data Set ◽  
Scattering Attenuation ◽  
Apparent Diffusion ◽  
Solid Liquid

Seismic attenuation is not due entirely to intrinsic properties; a component due to scattering effects is included. Although different techniques have been used to experimentally investigate the attenuation of seismic waves, not so many laboratory measurements of attenuation have taken into account the effect of scattering attenuation. Herein, partially frozen brine as a solid-liquid coexistence system is used to investigate attenuation phenomena. We obtained a series of 2D apparent diffusion coefficient (ADC) maps of the ice-brine coexisting system using a diffusion-weighted magnetic resonance imaging (DW-MRI) technique at [Formula: see text], and found a strongly heterogeneous spatial distribution of unfrozen brine. From these maps, we constructed a synthetic seismic data set propagating through 2D media, and generated synthetic data with a second-order finite-difference scheme for the 2D acoustic wave equation. We estimated ultrasonic scattering attenuation in such systems by the centroid frequency shift method and by assuming that the quality factor ([Formula: see text]-value) is independent of frequency. The estimated scattering attenuation ranges from 0.015 to 0.05, corresponding to 10% to 30% of the total attenuation measured in laboratory experiments.

scholarly journals Brain Magnetic Resonance Spectroscopy in Episodic Hepatic Encephalopathy

2012 ◽  
Vol 33 (2) ◽  
pp. 272-277 ◽  
Author(s):  
Laia Chavarria ◽  
Juli Alonso ◽  
Rita García-Martínez ◽  
Macarena Simón-Talero ◽  
Meritxell Ventura-Cots ◽  
...  
Keyword(s):  
Hepatic Encephalopathy ◽  
Magnetic Resonance ◽  
Water Distribution ◽  
White Matter Lesions ◽  
Resonance Spectroscopy ◽  
Brain White Matter ◽  
High Apparent Diffusion Coefficient ◽  
Apparent Diffusion ◽  
Brain Water

Brain magnetic resonance (MR) study has shown metabolic abnormalities and changes in water distribution of the brain tissue that may relate to the pathogenesis of hepatic encephalopathy (HE). We designed a study to investigate the disturbances in brain water and metabolites during episodic HE using a 3-T MR scanner. Cirrhotic patients with different grades of HE underwent MR during hospitalization ( n = 18). The MR was repeated at 6 weeks' follow-up ( n = 14). The results were compared with those of a group of healthy volunteers ( n = 8). During episodic HE, brain diffusion-weighted imaging showed a high apparent diffusion coefficient (ADC) (12% to 14%) that decreased during follow-up (–1% to −4%). These disturbances were accompanied by high glutamine (581%), low choline (–31%), and low myo-inositol (–86%) peaks on MR spectroscopy. In overt HE, patients showed high glutamine that decreased during follow-up (–22%). In addition, these patients exhibited a rise in plasma S100 beta and enlargement of brain white-matter lesions. In conclusion, several disturbances detected by MR support the presence of impaired brain water homeostasis during episodic HE. Although astrocytes have a major role in this condition, brain edema during episodic HE may be extracellular and does not appear to be directly responsible for the development of neurologic manifestations.

Diffusion Tensor Imaging with Three-dimensional Fiber Tractography of Traumatic Axonal Shearing Injury: An Imaging Correlate for the Posterior Callosal “Disconnection” Syndrome: Case Report

Neurosurgery ◽  
2005 ◽  
Vol 56 (1) ◽  
pp. E195-E201 ◽  
Author(s):  
Tuong H. Le ◽  
Pratik Mukherjee ◽  
Roland G. Henry ◽  
Jeffrey I. Berman ◽  
Marcus Ware ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Diffusion Tensor ◽  
Three Dimensional ◽  
Magnetic Resonance Images ◽  
Fiber Tractography ◽  
Disconnection Syndrome ◽  
Apparent Diffusion

Abstract OBJECTIVE: To demonstrate that magnetic resonance diffusion tensor imaging (DTI) with three-dimensional (3-D) fiber tractography can visualize traumatic axonal shearing injury that results in posterior callosal disconnection syndrome. METHODS: A 22-year-old man underwent serial magnetic resonance imaging 3 days and 12 weeks after blunt head injury. The magnetic resonance images included whole-brain DTI acquired with a single-shot spin echo echoplanar sequence. 3-D DTI fiber tractography of the splenium of the corpus callosum was performed. Quantitative DTI parameters, including apparent diffusion coefficient and fractional anisotropy, from the site of splenial injury were compared with those of a normal adult male volunteer. RESULTS: Conventional magnetic resonance images revealed findings of diffuse axonal injury, including a lesion at the midline of the splenium of the corpus callosum. DTI performed 3 days posttrauma revealed that the splenial lesion had reduced apparent diffusion coefficient and fractional anisotropy, reflecting a large decrease in the magnitude of diffusion parallel to the white matter fibers, which had partially recovered as revealed by follow-up DTI 12 weeks postinjury. 3-D tractography revealed an interruption of the white matter fibers in the posteroinferior aspect of the splenium that correlated with the patient's left hemialexia, a functional deficit caused by disconnection of the right visual cortex from the language centers of the dominant left hemisphere. CONCLUSION: DTI with 3-D fiber tractography can visualize acute axonal shearing injury, which may have prognostic value for the cognitive and neurological sequelae of traumatic brain injury.

scholarly journals Autosegmentation of Prostate Zones and Cancer Regions from Biparametric Magnetic Resonance Images by Using Deep-Learning-Based Neural Networks

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2709
Author(s):  
Chih-Ching Lai ◽  
Hsin-Kai Wang ◽  
Fu-Nien Wang ◽  
Yu-Ching Peng ◽  
Tzu-Ping Lin ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Deep Learning ◽  
Magnetic Resonance ◽  
Peripheral Zone ◽  
Magnetic Resonance Images ◽  
Dice Similarity Coefficient ◽  
Resonance Imaging ◽  
Prostate Mri ◽  
Diffusion Weighted Images ◽  
Apparent Diffusion

The accuracy in diagnosing prostate cancer (PCa) has increased with the development of multiparametric magnetic resonance imaging (mpMRI). Biparametric magnetic resonance imaging (bpMRI) was found to have a diagnostic accuracy comparable to mpMRI in detecting PCa. However, prostate MRI assessment relies on human experts and specialized training with considerable inter-reader variability. Deep learning may be a more robust approach for prostate MRI assessment. Here we present a method for autosegmenting the prostate zone and cancer region by using SegNet, a deep convolution neural network (DCNN) model. We used PROSTATEx dataset to train the model and combined different sequences into three channels of a single image. For each subject, all slices that contained the transition zone (TZ), peripheral zone (PZ), and PCa region were selected. The datasets were produced using different combinations of images, including T2-weighted (T2W) images, diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) images. Among these groups, the T2W + DWI + ADC images exhibited the best performance with a dice similarity coefficient of 90.45% for the TZ, 70.04% for the PZ, and 52.73% for the PCa region. Image sequence analysis with a DCNN model has the potential to assist PCa diagnosis.

An emerging technology: Nuclear magnetic resonance microscopy

1988 ◽  
Vol 46 ◽  
pp. 1000-1001
Author(s):  
M.J. Hennessy ◽  
E. Kwok
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Basic Research ◽  
Local Environment ◽  
Magnetic Resonance Images ◽  
Nmr Microscopy ◽  
Mri Scans ◽  
Temperature Relaxation ◽  
Nuclear Magnetic

Much progress in nuclear magnetic resonance microscope has been made in the last few years as a result of improved instrumentation and techniques being made available through basic research in magnetic resonance imaging (MRI) technologies for medicine. Nuclear magnetic resonance (NMR) was first observed in the hydrogen nucleus in water by Bloch, Purcell and Pound over 40 years ago. Today, in medicine, virtually all commercial MRI scans are made of water bound in tissue. This is also true for NMR microscopy, which has focussed mainly on biological applications. The reason water is the favored molecule for NMR is because water is,the most abundant molecule in biology. It is also the most NMR sensitive having the largest nuclear magnetic moment and having reasonable room temperature relaxation times (from 10 ms to 3 sec). The contrast seen in magnetic resonance images is due mostly to distribution of water relaxation times in sample which are extremely sensitive to the local environment.

Functional information from magnetic resonance imaging

1995 ◽  
Vol 53 ◽  
pp. 84-85
Author(s):  
Alan P. Koretsky ◽  
Afonso Costa e Silva ◽  
Yi-Jen Lin
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Cancer Biology ◽  
Imaging Modality ◽  
Magnetic Resonance Images ◽  
Great Success ◽  
Functional Information ◽  
Resonance Imaging ◽  
High Resolution Mri

Magnetic resonance imaging (MRI) has become established as an important imaging modality for the clinical management of disease. This is primarily due to the great tissue contrast inherent in magnetic resonance images of normal and diseased organs. Due to the wide availability of high field magnets and the ability to generate large and rapidly switched magnetic field gradients there is growing interest in applying high resolution MRI to obtain microscopic information. This symposium on MRI microscopy highlights new developments that are leading to increased resolution. The application of high resolution MRI to significant problems in developmental biology and cancer biology will illustrate the potential of these techniques.In combination with a growing interest in obtaining high resolution MRI there is also a growing interest in obtaining functional information from MRI. The great success of MRI in clinical applications is due to the inherent contrast obtained from different tissues leading to anatomical information.

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