scholarly journals If the skull fits: magnetic resonance imaging and microcomputed tomography for combined analysis of brain and skull phenotypes in the mouse

2012 ◽  
Vol 44 (20) ◽  
pp. 992-1002 ◽  
Author(s):  
Brian J. Nieman ◽  
Marissa C. Blank ◽  
Brian B. Roman ◽  
R. Mark Henkelman ◽  
Kathleen J. Millen
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Prognostic Significance ◽  
Microcomputed Tomography ◽  
Complete Characterization ◽  
Mammalian Brain ◽  
Resonance Imaging ◽  
The Relationship ◽  
The Brain

The mammalian brain and skull develop concurrently in a coordinated manner, consistently producing a brain and skull that fit tightly together. It is common that abnormalities in one are associated with related abnormalities in the other. However, this is not always the case. A complete characterization of the relationship between brain and skull phenotypes is necessary to understand the mechanisms that cause them to be coordinated or divergent and to provide perspective on the potential diagnostic or prognostic significance of brain and skull phenotypes. We demonstrate the combined use of magnetic resonance imaging and microcomputed tomography for analysis of brain and skull phenotypes in the mouse. Co-registration of brain and skull images allows comparison of the relationship between phenotypes in the brain and those in the skull. We observe a close fit between the brain and skull of two genetic mouse models that both show abnormal brain and skull phenotypes. Application of these three-dimensional image analyses in a broader range of mouse mutants will provide a map of the relationships between brain and skull phenotypes generally and allow characterization of patterns of similarities and differences.

scholarly journals Simulating Local Deformations in the Human Cortex Due to Blood Flow-Induced Changes in Mechanical Tissue Properties: Impact on Functional Magnetic Resonance Imaging

2021 ◽  
Vol 15 ◽  
Author(s):  
Mahsa Zoraghi ◽  
Nico Scherf ◽  
Carsten Jaeger ◽  
Ingolf Sack ◽  
Sebastian Hirsch ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Brain Tissue ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Tissue Properties ◽  
The Relationship ◽  
The Brain

Investigating human brain tissue is challenging due to the complexity and the manifold interactions between structures across different scales. Increasing evidence suggests that brain function and microstructural features including biomechanical features are related. More importantly, the relationship between tissue mechanics and its influence on brain imaging results remains poorly understood. As an important example, the study of the brain tissue response to blood flow could have important theoretical and experimental consequences for functional magnetic resonance imaging (fMRI) at high spatial resolutions. Computational simulations, using realistic mechanical models can predict and characterize the brain tissue behavior and give us insights into the consequent potential biases or limitations of in vivo, high-resolution fMRI. In this manuscript, we used a two dimensional biomechanical simulation of an exemplary human gyrus to investigate the relationship between mechanical tissue properties and the respective changes induced by focal blood flow changes. The model is based on the changes in the brain’s stiffness and volume due to the vasodilation evoked by neural activity. Modeling an exemplary gyrus from a brain atlas we assessed the influence of different potential mechanisms: (i) a local increase in tissue stiffness (at the level of a single anatomical layer), (ii) an increase in local volume, and (iii) a combination of both effects. Our simulation results showed considerable tissue displacement because of these temporary changes in mechanical properties. We found that the local volume increase causes more deformation and consequently higher displacement of the gyrus. These displacements introduced considerable artifacts in our simulated fMRI measurements. Our results underline the necessity to consider and characterize the tissue displacement which could be responsible for fMRI artifacts.

scholarly journals Possibilities of Magnetic Resonance Imaging of the Brain in Infantile Cerebral Palsy

2018 ◽  
Vol 17 (4) ◽  
pp. 272-278 ◽  
Author(s):  
Anna N. Belova ◽  
Gennadii E. Sheiko ◽  
Evgenii А. Klyuev ◽  
Maksim G. Dunaev
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cerebral Palsy ◽  
Magnetic Resonance ◽  
Brain Damage ◽  
Prognostic Significance ◽  
Childhood Disability ◽  
Resonance Imaging ◽  
Infantile Cerebral Palsy ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

Infantile cerebral palsy (ICP) is the main cause of childhood disability and is characterized by a non-progressive lesion and/or impaired development of the brain in a foetus or newborn. Magnetic resonance imaging (MRI) is a modern non-invasive method with extensive capabilities for diagnosing brain damage in ICP. The review focuses on anatomical structural MR patterns of brain damage in ICP and gives the present-day classification of MR changes in this disease. The role of MRI in determining the duration of brain damage in ICP has been considered. Data on the ratio of ICP phenotypes to pathological MR findings has been presented. Neuroimaging prognostic biomarkers are discussed. It is emphasized that many questions regarding the prognostic significance of MR findings remain unresolved; prospects are associated with the use of new MRI modalities such as functional and diffusiontensor MRI.

scholarly journals The Relationship between Diffusion-Weighted Magnetic Resonance Imaging Lesions and 24-Hour Rhythm Holter Findings in Patients with Cryptogenic Stroke

Medicina ◽  
2019 ◽  
Vol 55 (2) ◽  
pp. 38 ◽  
Author(s):  
Muhammet Gürdoğan ◽  
Sezgin Kehaya ◽  
Selçuk Korkmaz ◽  
Servet Altay ◽  
Uğur Özkan ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Prognostic Significance ◽  
Cryptogenic Stroke ◽  
Multivariate Logistic Regression Analysis ◽  
Resonance Imaging ◽  
Cranial Magnetic Resonance Imaging ◽  
Diffusion Weighted ◽  
Weighted Magnetic Resonance Imaging ◽  
The Relationship

Background and objectives: Cranial magnetic resonance imaging findings of patients considered to be cryptogenic stroke may be useful in determining the clinical and prognostic significance of arrhythmias, such as atrial premature beats and atrial run attacks, that are frequently encountered in rhythm Holter analysis. This study was conducted to investigate the relationship between short atrial runs and frequent premature atrial contractions detected in Holter monitors and infarct distributions in cranial magnetic resonance imaging of patients diagnosed with cryptogenic stroke. Materials and Methods: We enrolled the patients with acute ischemic stroke whose etiology were undetermined. We divided the patients in two groups according to diffusion-weighted magnetic resonance imaging as single or multiple vascular territory acute infarcts. The demographic, clinical, laboratory, echocardiographic, and rhythm Holter analyses were compared. Results: The study investigated 106 patients diagnosed with cryptogenic stroke. Acute cerebral infarctions were detected in 31% of the investigated patients in multiple territories and in 69% in a single territory. In multivariate logistic regression analysis, the total premature atrial contraction count (OR = 1.002, 95% CI: 1.001–1.004, p = 0.001) and short atrial run count (OR = 1.086, 95% CI: 1.021–1.155, p = 0.008) were found as independent variables that could distinguish between infarctions in a single or in multiple vascular territories. Conclusions: Rhythm Holter monitoring of patients with infarcts detected in multiple vascular territories showed significantly higher premature atrial contractions and short atrial run attacks. More effort should be devoted to the identification of cardioembolic etiology in cryptogenic stroke patients with concurrent acute infarcts in the multiple vascular territories of the brain.

Сauses of Dizziness in Patients with Suspected Stroke

2018 ◽  
Vol 7 (3) ◽  
pp. 217-221
Author(s):  
E. V. Shevchenko ◽  
G. R. Ramazanov ◽  
S. S. Petrikov
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Demyelinating Disease ◽  
Heart Rhythm ◽  
Diagnostic Methods ◽  
Deficiency Anemia ◽  
Resonance Imaging ◽  
Peripheral Vestibulopathy ◽  
Suspected Stroke ◽  
The Brain

Background Acute dizziness may be the only symptom of stroke. Prevalence of this disease among patients with isolated dizziness differs significantly and depends on study design, inclusion criteria and diagnostic methods. In available investigations, we did not find any prospective studies where magnetic resonance imaging, positional maneuvers, and Halmagyi-Curthoys test had been used to clarify a pattern of diseases with isolated acute dizziness and suspected stroke.Aim of study To clarify the pattern of the causes of dizziness in patients with suspected acute stroke.Material and methods We examined 160 patients admitted to N.V. Sklifosovsky Research Institute for Emergency Medicine with suspected stroke and single or underlying complaint of dizziness. All patients were examined with assessment of neurological status, Dix-Hollpike and Pagnini-McClure maneuvers, HalmagyiCurthoys test, triplex scans of brachiocephalic arteries, transthoracic echocardiography, computed tomography (CT) and magnetic resonance imaging (MRI) of the brain with magnetic field strength 1.5 T. MRI of the brain was performed in patients without evidence of stroke by CT and in patients with stroke of undetermined etiology according to the TOAST classification.Results In 16 patients (10%), the cause of dizziness was a disease of the brain: ischemic stroke (n=14 (88%)), hemorrhage (n=1 (6%)), transient ischemic attack (TIA) of posterior circulation (n=1 (6%)). In 70.6% patients (n=113), the dizziness was associated with peripheral vestibulopathy: benign paroxysmal positional vertigo (n=85 (75%)), vestibular neuritis (n=19 (17%)), Meniere’s disease (n=7 (6%)), labyrinthitis (n=2 (1,3%)). In 6.9% patients (n=11), the cause of dizziness was hypertensive encephalopathy, 1.9% of patients (n=3) had heart rhythm disturbance, 9.4% of patients (n=15) had psychogenic dizziness, 0.6% of patients (n=1) had demyelinating disease, and 0.6% of patients (n=1) had hemic hypoxia associated with iron deficiency anemia.Conclusion In 70.6% patients with acute dizziness, admitted to hospital with a suspected stroke, peripheral vestibulopathy was revealed. Only 10% of patients had a stroke as a cause of dizziness.

scholarly journals The Correlations between Horizontal and Vertical Peripheral Refractions and Human Eye Shape Using Magnetic Resonance Imaging in Highly Myopic Eyes

Healthcare ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 966
Author(s):  
Hui-Ying Kuo ◽  
John Ching-Jen Hsiao ◽  
Jing-Jie Chen ◽  
Chi-Hung Lee ◽  
Chun-Chao Chuang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Shape Deformation ◽  
Spherical Equivalent ◽  
Horizontal Meridian ◽  
Resonance Imaging ◽  
Vertical Meridian ◽  
Useful Knowledge ◽  
Human Eye ◽  
The Relationship

The aim of this study was to determine the relationship between relative peripheral refraction and retinal shape by 2-D magnetic resonance imaging in high myopes. Thirty-five young adults aged 20 to 30 years participated in this study with 16 high myopes (spherical equivalent < −6.00 D) and 19 emmetropes (+0.50 to −0.50 D). An open field autorefractor was used to measure refractions from the center out to 60° in the horizontal meridian and out to around 20° in the vertical meridian, with a step of 3 degrees. Axial length was measured by using A-scan ultrasonography. In addition, images of axial, sagittal, and tangential sections were obtained using 2-D magnetic resonance imaging. The highly myopic group had a significantly relative peripheral hyperopic refraction and showed a prolate ocular shape compared to the emmetropic group. The highly myopic group had relative peripheral hyperopic refraction and showed a prolate ocular form. Significant differences in the ratios of height/axial (1.01 ± 0.02 vs. 0.94 ± 0.03) and width/axial (0.99 ± 0.17 vs. 0.93 ± 0.04) were found from the MRI images between the emmetropic and the highly myopic eyes (p < 0.001). There was a negative correlation between the retina’s curvature and relative peripheral refraction for both temporal (Pearson r = −0.459; p < 0.01) and nasal (Pearson r = −0.277; p = 0.011) retina. For the highly myopic eyes, the amount of peripheral hyperopic defocus is correlated to its ocular shape deformation. This could be the first study investigating the relationship between peripheral refraction and ocular dimension in high myopes, and it is hoped to provide useful knowledge of how the development of myopia changes human eye shape.

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