Comparison of Two Software Packages for Perfusion Imaging: Ischemic Core and Penumbra Estimation and Patient Triage in Acute Ischemic Stroke.

Automated postprocessing packages have been developed for managing acute ischemic stroke (AIS). These packages identify ischemic core and penumbra using either computed tomographic perfusion imaging (CTP) data or magnetic resonance imaging (MRI) data. Measurements of abnormal tissues and treatment decisions derived from different vendors can vary.

Brain structural alterations detected by an automatic quantified tool as an indicator for MCI diagnosing in type 2 diabetes mellitus patients: A magnetic resonance imaging study.

Background And Objectives: Type 2 diabetes mellitus (T2DM) is an important risk factors for mild cognitive impairment (MCI). Structural magnetic resonance imaging (sMRI) is an effective and widely used method to investigate brain pathomorphological injury in neural diseases. In present study, we aimed to determine the brain regional alterations that correlated to the incidence of MCI in T2DM patients.

Hippocampal and Amygdalar Morphological Abnormalities in Alzheimer's Disease Based on Three Chinese MRI Datasets.

Background: Early detection of Alzheimer's disease (AD) and its early stage, the mild cognitive impairment (MCI), has important scientific, clinical and social significance. Magnetic resonance imaging (MRI) based statistical shape analysis provides an opportunity to detect regional structural abnormalities of brain structures caused by AD and MCI.

Objective: In this work, we aimed to employ a well-established statistical shape analysis pipeline, in the framework of large deformation diffeomorphic metric mapping, to identify and quantify the regional shape abnormalities of the bilateral hippocampus and amygdala at different prodromal stages of AD, using three Chinese MRI datasets collected from different domestic hospitals.

Deep-Learning-Based Segmentation and Localization of White Matter Hyperintensities on Magnetic Resonance Images.

White matter magnetic resonance hyperintensities of presumed vascular origin, which could be widely observed in elderly people, and has significant importance in multiple neurological studies. Quantitative measurement usually relies heavily on manual or semi-automatic delineation and intuitive localization, which is time-consuming and observer-dependent. Current automatic quantification methods focus mainly on the segmentation, but the spatial distribution of lesions plays a vital role in clinical diagnosis.

Revealing hemodynamic heterogeneity of gliomas based on signal profile features of dynamic susceptibility contrast-enhanced MRI.

Dynamic susceptibility contrast enhanced magnetic resonance imaging (DSC MRI) is widely used for studying blood perfusion in brain tumors. While the time-dependent change of MRI signals related to the concentration of the tracer is used to derive the hemodynamic parameters such as regional blood volume and flow into tumors, the tissue-specific information associated with variations in profiles of signal time course is often overlooked. We report a new approach of combining model free independent component analysis (ICA) identification of specific signal profiles of DSC MRI time course data and extraction of the features from those time course profiles to interrogate time course data followed by calculating the region specific blood volume based on selected individual time courses.

Traumatic Brain Injury Results in Dynamic Brain Structure Changes Leading to Acute and Chronic Motor Function Deficits in a Pediatric Piglet Model.

Traumatic brain injury (TBI) is a leading cause of death and disability in children. Pediatric TBI patients often suffer from crippling cognitive, emotional, and motor function deficits that have negative lifelong effects. The objective of this study was to longitudinally assess TBI pathophysiology using multi-parametric magnetic resonance imaging (MRI), gait analysis, and histological approaches in a pediatric piglet model.

Metabolite Profile of Alzheimer's Disease in the Frontal Cortex as Analyzed by HRMAS H NMR.

Investigation on neurochemical changes in the frontal cortex in individuals with Alzheimer's disease (AD) and different Apolipoprotein E (APOE) genotypes, using solid-state high-resolution NMR analysis, may lead to a better understanding of the neurochemistry associated with AD as well as new AD-specific metabolite biomarkers that might potentially improve the clinical diagnosis of AD. Intact tissue samples of the frontal cortex were obtained from 11 patients and 11 age-matched non-demented controls. Metabolite profiles in all samples were analyzed , using solid-state high-resolution magic angle spinning (HRMAS) 600 MHz H nuclear magnetic resonance (NMR).

Evaluation of neuregulin-1's neuroprotection against ischemic injury in rats using diffusion tensor imaging.

Stroke is a devastating neurovascular disorder that results in damage to neurons and white matter tracts. It has been previously demonstrated that neuregulin-1 (NRG-1) protects neurons from ischemic injury following stroke. Here, diffusion tensor imaging (DTI) was utilized to characterize the effects of NRG-1 treatment on cererbral infarction and integrity of white matter after ischemic insult using a permanent middle celebral artery occlusion (pMCAo) rat model.

Progressive Assessment of Ischemic Injury to White Matter Using Diffusion Tensor Imaging: A Preliminary Study of a Macaque Model of Stroke.

Background: Previous Diffusion Tensor Imaging (DTI) studies have demonstrated the temporal evolution of stroke injury in grey matter and white matter can be characterized by DTI indices. However, it still remains not fully understood how the DTI indices of white matter are altered progressively during the hyperacute (first 6 hours) and acute stage of stroke (≤ 1 week). In the present study, DTI was employed to characterize the temporal evolution of infarction and white matter injury after stroke insult using a macaque model with permanent ischemic occlusion.

Longitudinal MRI evaluation of neuroprotective effects of pharmacologically induced hypothermia in experimental ischemic stroke.

Pharmacologically induced hypothermia (PIH) shows promising neuroprotective effects after stroke insult. However, the dynamic evolution of stroke infarct during the hypothermic therapy has not been understood very well. In the present study, MRI was utilized to longitudinally characterize the infarct evolution in a mouse model of ischemic stroke treated by PIH using the neurotensin agonist HPI201.

Amyloid-Related Imaging Abnormalities in an Aged Squirrel Monkey with Cerebral Amyloid Angiopathy.

Amyloid-related imaging abnormalities (ARIA) in magnetic resonance imaging scans have emerged as indicators of potentially serious side effects in clinical trials of therapeutics for Alzheimer's disease. These anomalies include an edematous type (ARIA-E) that appears as hyperintense (bright) regions by T2-weighted MRI, and a type characterized by the deposition of hemosiderin (ARIA-H) that elicits a hypointense signal, especially in T2* susceptibility weighted images. ARIA in general has been linked to the presence of amyloid-β (Aβ)-type cerebral amyloid angiopathy, an accumulation of misfolded Aβ protein in the vascular wall that impairs the integrity of brain blood vessels.

Genetic engineered molecular imaging probes for applications in cell therapy: emphasis on MRI approach.

Recent advances in stem cell-based regenerative medicine, cell replacement therapy, and genome editing technologies (i.e. CRISPR-Cas 9) have sparked great interest in cell monitoring.

Determining Cardiac Fiber Orientation Using FSL and Registered Ultrasound/DTI volumes.

Accurate extraction of cardiac fiber orientation from diffusion tensor imaging is important for determining heart structure and function. However, the acquisition of magnetic resonance (MR) diffusion tensor images is costly and time consuming. By comparison, cardiac ultrasound imaging is rapid and relatively inexpensive, but it lacks the capability to directly measure fiber orientations.

Register cardiac fiber orientations from 3D DTI volume to 2D ultrasound image of rat hearts.

Two-dimensional (2D) ultrasound or echocardiography is one of the most widely used examinations for the diagnosis of cardiac diseases. However, it only supplies the geometric and structural information of the myocardium. In order to supply more detailed microstructure information of the myocardium, this paper proposes a registration method to map cardiac fiber orientations from three-dimensional (3D) magnetic resonance diffusion tensor imaging (MR-DTI) volume to the 2D ultrasound image.

3D imaging of rat hearts by high frequency ultrasound and its application in myofiber orientation wrapping.

Cardiac ultrasound plays an important role in the imaging of hearts in basic cardiovascular research and clinical examinations. 3D ultrasound imaging can provide the geometry or motion information of the heart. Especially, the wrapping of cardiac fiber orientations to the ultrasound volume could supply useful information on the stress distributions and electric action spreading.

Simulating cardiac ultrasound image based on MR diffusion tensor imaging.

Purpose: Cardiac ultrasound simulation can have important applications in the design of ultrasound systems, understanding the interaction effect between ultrasound and tissue and setting the ground truth for validating quantification methods. Current ultrasound simulation methods fail to simulate the myocardial intensity anisotropies. New simulation methods are needed in order to simulate realistic ultrasound images of the heart.

Spatio-temporal assessment of the neuroprotective effects of neuregulin-1 on ischemic stroke lesions using MRI.

The neuroprotective effects of neuregulin-1 (NRG-1) on stroke lesions were assessed longitudinally in rats with middle cerebral artery occlusion (MCAo) using MRI. Sprague-Dawley rats (n=16, 250±20g) underwent permanent MCAo surgery with cerebral blood flow (CBF) monitored by laser doppler flowmetry at ipsilateral side of bregma for 20min post-occlusion. A single 50μl bolus dose of NRG-1 or vehicle was administered into the left internal carotid artery immediately prior to MCAo.

Temporal evolution of ischemic lesions in nonhuman primates: a diffusion and perfusion MRI study.

Background And Purpose: Diffusion-weighted imaging (DWI) and perfusion MRI were used to examine the spatiotemporal evolution of stroke lesions in adult macaques with ischemic occlusion.

Methods: Permanent MCA occlusion was induced with silk sutures through an interventional approach via the femoral artery in adult rhesus monkeys (n = 8, 10-21 years old). The stroke lesions were examined with high-resolution DWI and perfusion MRI, and T2-weighted imaging (T2W) on a clinical 3T scanner at 1-6, 48, and 96 hours post occlusion and validated with H&E staining.

Mapping Cardiac Fiber Orientations from High-Resolution DTI to High-Frequency 3D Ultrasound.

The orientation of cardiac fibers affects the anatomical, mechanical, and electrophysiological properties of the heart. Although echocardiography is the most common imaging modality in clinical cardiac examination, it can only provide the cardiac geometry or motion information without cardiac fiber orientations. If the patient's cardiac fiber orientations can be mapped to his/her echocardiography images in clinical examinations, it may provide quantitative measures for diagnosis, personalized modeling, and image-guided cardiac therapies.

Quantitative multiparametric MRI assessment of glioma response to radiotherapy in a rat model.

Background: The inability of structural MRI to accurately measure tumor response to therapy complicates care management for patients with gliomas. The purpose of this study was to assess the potential of several noninvasive functional and molecular MRI biomarkers for the assessment of glioma response to radiotherapy.

Methods: Fourteen U87 tumor-bearing rats were irradiated using a small-animal radiation research platform (40 or 20 Gy), and 6 rats were used as controls.

Radiation induced brain injury: assessment of white matter tracts in a pre-clinical animal model using diffusion tensor MR imaging.

We aim to study radiation induced white matter injury in a pre-clinical model using Diffusion tensor MR imaging (DTI). Nineteen 12-week old Sprague-Dawley rats were irradiated to the right hemisphere using a linear accelerator. The dose distribution map was coregistered to the DTI map to generate the actual radiation dose to each white matter tract.

Combined use of 18F-FDG PET/CT, DW-MRI, and DCE-MRI in treatment response for preoperative chemoradiation therapy in locally invasive rectal cancers.

We investigated if 18F-FDG PET/CT, DW-MRI, and DCE-MRI are able to predict preoperative chemoradiation therapy (CRT) response in patients with T3-4 rectal adenocarcinomas. MRI and PET/CT scans were performed within 1 week, at baseline, early midtreatment (2 weeks of CRT), and posttreatment (6 weeks after completing CRT). Responders (n = 4) and nonresponders (n = 4) were defined according to tumor regression grade by histology.

Diffusion tensor magnetic resonance imaging of rat glioma models: a correlation study of MR imaging and histology.

Introduction: Diffusion tensor magnetic resonance (MR) imaging (DTI) can be used to characterize the microstructures of ordered biological tissues. This study was designed to assess histological features of gliomas and surrounding brain tissues in rats using DTI.

Methods: Three types of tumors, a 9L gliosarcoma (n = 8), a F98 glioma (n = 5), and a human glioblastoma xenograft (GBM22; n = 8) were incubated in rat brains and underwent conventional MRI and DTI scanning using a 4.

Growth properties of SF188/V+ human glioma in rats in vivo observed by magnetic resonance imaging.

SF188/V+ is a highly vascular human glioma model that is based on transfection of vascular endothelial growth factor (VEGF) cDNA into SF188/V- cells. This study aims to assess its growth and vascularity properties in vivo in a rat model. Thirty-two adult rats were inoculated with SF188/V+ tumor cells, and, for comparison, five were inoculated with SF188/V- tumor cells.