scholarly journals Magnetic Resonance Imaging of the Nose and Paranasal Sinuses

1989 ◽  
Vol 82 (2) ◽  
pp. 84-87 ◽  
Author(s):  
G A S Lloyd
Keyword(s):  
Magnetic Resonance ◽  
Malignant Disease ◽  
Malignant Tumours ◽  
Additional Advantage ◽  
Paramagnetic Contrast Agent ◽  
Sinus Disease ◽  
Wide Range ◽  
Main Disadvantage ◽  
Magnetic Resonance Scanning ◽  
Nose And Sinuses

Seventy-five patients with a wide range of sinus disease have been investigated by magnetic resonance (MR): these included congenital conditions, allergic and inflammatory sinus disease, fungus infections, and the necrotizing granulomata. In addition, a variety of benign and malignant tumours have been examined, and in the more recent sinus malignancies the paramagnetic contrast agent, Gadolinium (Gd) DTPA (Schering Health Care) has been used. This experience of magnetic resonance scanning has shown that it is superior to computed tomography in demonstrating the extent of malignant disease in the nose and sinuses; most especially when Gd DTPA is used, reaching an accuracy of over 96% by biopsy correlation. An additional advantage of this technique is the wide coverage of the head and neck for the assessment of malignant disease, provided by direct 3 plane imaging and the multislice facility. The main disadvantage of magnetic resonance of the sinuses is the poor demonstration of calcification and bone. For this reason the MR scans may need to be augmented by high resolution CT performed specifically to show bone detail.

scholarly journals Measuring Cerebral Blood Flow Using Magnetic Resonance Imaging Techniques

1999 ◽  
Vol 19 (7) ◽  
pp. 701-735 ◽  
Author(s):  
Fernando Calamante ◽  
David L. Thomas ◽  
Gaby S. Pell ◽  
Jonna Wiersma ◽  
Robert Turner
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Imaging Techniques ◽  
Absolute Quantification ◽  
Dynamic Susceptibility ◽  
Resonance Imaging ◽  
Dynamic Susceptibility Contrast ◽  
Paramagnetic Contrast Agent ◽  
Wide Range ◽  
Magnetic Resonance Imaging Techniques

Magnetic resonance imaging techniques measuring CBF have developed rapidly in the last decade, resulting in a wide range of available methods. The most successful approaches are based either on dynamic tracking of a bolus of a paramagnetic contrast agent (dynamic susceptibility contrast) or on arterial spin labeling. This review discusses their principles, possible pitfalls, and potential for absolute quantification and outlines clinical and neuroscientific applications.

Role of Cardiac MRI in Detecting Familial Hypertrophic Cardiomyopathy: Review

2016 ◽  
Vol 1 (1) ◽  
pp. 4
Author(s):  
Marymol Koshy ◽  
Bushra Johari ◽  
Mohd Farhan Hamdan ◽  
Mohammad Hanafiah
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Magnetic Resonance ◽  
Genetic Disorder ◽  
Familial Hypertrophic Cardiomyopathy ◽  
Non Invasive ◽  
Wide Range ◽  
Proper Diagnosis ◽  
Magnetic Resonance Imaging Mri ◽  
Potential Use

Hypertrophic cardiomyopathy (HCM) is a global disease affecting people of various ethnic origins and both genders. HCM is a genetic disorder with a wide range of symptoms, including the catastrophic presentation of sudden cardiac death. Proper diagnosis and treatment of this disorder can relieve symptoms and prolong life. Non-invasive imaging is essential in diagnosing HCM. We present a review to deliberate the potential use of cardiac magnetic resonance (CMR) imaging in HCM assessment and also identify the risk factors entailed with risk stratification of HCM based on Magnetic Resonance Imaging (MRI).

scholarly journals Cerebral embolism due to left atrial myxoma in a patient presenting with chest pain and ST-segment elevation: a case report

2020 ◽  
Author(s):  
António Fontes ◽  
Nuno Dias-Ferreira ◽  
Anabela Tavares ◽  
Fátima Neves
Keyword(s):  
Myocardial Infarction ◽  
Chest Pain ◽  
Magnetic Resonance ◽  
Left Atrial ◽  
Left Ventricular ◽  
Atrial Myxoma ◽  
Left Atrial Myxoma ◽  
St Segment ◽  
Wide Range ◽  
St Elevation

Abstract Background Myocarditis is an uncommon, potentially life-threatening disease that presents with a wide range of symptoms. In acute myocarditis, chest pain (CP) may mimic typical angina and also be associated with electrocardiographic changes, including an elevation of the ST-segment. A large percentage (20–56%) of myxomas are found incidentally. Case summary A 62-year-old female presenting with sudden onset CP and infero-lateral ST-elevation in the electrocardiogram. The diagnosis of ST-elevation myocardial infarction was presumed and administered tenecteplase. The patient was immediately transported to a percutaneous coronary intervention centre. She complained of intermittent diplopia during transport and referred constitutional symptoms for the past 2 weeks. Coronary angiography showed normal arteries. The echocardiogram revealed moderate to severe left ventricular systolic dysfunction due to large areas of akinesia sparing most of the basal segments, and a mobile mass inside the left atrium attached to the septum. The cardiac magnetic resonance (CMR) suggested the diagnosis of myocarditis with concomitant left atrial myxoma. The patient underwent resection of the myxoma. Neurological evaluation was performed due to mild vertigo while walking and diplopia in extreme eye movements. The head magnetic resonance imaging identified multiple infracentimetric lesions throughout the cerebral parenchyma compatible with an embolization process caused by fragments of the tumour. Discussion Myocarditis can have various presentations may mimic acute myocardial infarction and CMR is critical to establish the diagnosis. Myxoma with embolic complications requires emergent surgery. To the best of our knowledge, this is the first case reported in the applicable literature of a myxoma diagnosed during a myocarditis episode.

scholarly journals INSPECTOR: free software for magnetic resonance spectroscopy data inspection, processing, simulation and analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Martin Gajdošík ◽  
Karl Landheer ◽  
Kelley M. Swanberg ◽  
Christoph Juchem
Keyword(s):  
Magnetic Resonance ◽  
Quality Management ◽  
Magnetic Resonance Spectroscopy ◽  
Data Processing ◽  
Biomedical Research ◽  
Clinical Diagnostics ◽  
Resonance Spectroscopy ◽  
User Friendliness ◽  
Wide Range

AbstractIn vivo magnetic resonance spectroscopy (MRS) is a powerful tool for biomedical research and clinical diagnostics, allowing for non-invasive measurement and analysis of small molecules from living tissues. However, currently available MRS processing and analytical software tools are limited in their potential for in-depth quality management, access to details of the processing stream, and user friendliness. Moreover, available MRS software focuses on selected aspects of MRS such as simulation, signal processing or analysis, necessitating the use of multiple packages and interfacing among them for biomedical applications. The freeware INSPECTOR comprises enhanced MRS data processing, simulation and analytical capabilities in a one-stop-shop solution for a wide range of biomedical research and diagnostic applications. Extensive data handling, quality management and visualization options are built in, enabling the assessment of every step of the processing chain with maximum transparency. The parameters of the processing can be flexibly chosen and tailored for the specific research problem, and extended confidence information is provided with the analysis. The INSPECTOR software stands out in its user-friendly workflow and potential for automation. In addition to convenience, the functionalities of INSPECTOR ensure rigorous and consistent data processing throughout multi-experiment and multi-center studies.

scholarly journals The role of magnetic resonance cholangiopancreatography and diffusion-weighted imaging for the differential diagnosis of obstructive biliary disorders

2017 ◽  
Vol 21 (1) ◽  
Author(s):  
Zeynep Cetiner-Alpay ◽  
Fatma Kulali ◽  
Aslihan Semiz-Oysu ◽  
Yasar Bukte ◽  
Kamil Ozdil
Keyword(s):  
Magnetic Resonance ◽  
Sensitivity And Specificity ◽  
Gold Standard ◽  
Diffusion Weighted Imaging ◽  
Magnetic Resonance Cholangiopancreatography ◽  
Malignant Tumours ◽  
Diagnostic Efficacy ◽  
Diffusion Weighted ◽  
Sensitivity Specificity ◽  
And Diffusion

Background: Although endoscopic retrograde cholangiopancreatography (ERCP) is accepted as the gold standard, there is a place for magnetic resonance cholangiopancreatography (MRCP) and diffusion-weighted imaging (DWI) in the diagnosis of obstructive biliary disorders.Aim: To compare the findings of MRCP with ERCP in patients with obstructive biliary disorders and to investigate the diagnostic efficacy of MRCP combined with DWI.Study design: Retrospective, analytic, cross-sectional study.Methods: The MRCP images of 126 patients who underwent both MRCP and ERCP owing to biliary obstruction were reviewed. Nine patients were excluded because of incomplete diagnostic workup or a long period (>3 months) between MRCP and ERCP. Ninety-two patients underwent DWI, which was also evaluated. The sensitivity, specificity and accuracy of MRCP and DWI were analysed.Results: The sensitivity, specificity and accuracy of MRCP according to ERCP results as the gold standard was 97%, 71% and 93% for assessment of biliary dilatation; 100%, 94.7% and 97.5% for the diagnosis of choledocholithiasis; 93.7%, 100% and 99% for the identification of benign strictures; 100%, 100% and 100% for the diagnosis of malignant tumours; and 100%, 100% and 100% for the detection of complicated hydatid cysts; respectively. The sensitivity and specificity of DWI for the diagnosis of malignant tumour was 100%. In the detection of choledocholithiasis, the sensitivity and specificity of DWI was 70.8% and 100%.Conclusions: MRCP is an alternative, non-invasive, diagnostic modality, comparable with ERCP for the evaluation of pancreaticobiliary diseases. DWI can be helpful for diagnosis of choledocholithiasis and tumours.

In Vitro Magnetic Resonance Scanning of Urinary Calculi

1994 ◽  
pp. 680-680 ◽  
Author(s):  
N. P. Cohen ◽  
H. N. Whitfield ◽  
G. Dolke ◽  
Y. Y. Ng ◽  
P. Armstrong
Keyword(s):  
Magnetic Resonance ◽  
Urinary Calculi ◽  
Magnetic Resonance Scanning

Brain abnormality detection using template matching

2018 ◽  
Vol 14 (4) ◽  
Author(s):  
G.B. Praveen ◽  
Anita Agrawal ◽  
Shrey Pareek ◽  
Amalin Prince
Keyword(s):  
Magnetic Resonance ◽  
Template Matching ◽  
Imaging Modality ◽  
Brain Mri ◽  
Tumor Segmentation ◽  
Processing Unit ◽  
Brain Disorders ◽  
Brain Tumor Segmentation ◽  
Central Processing ◽  
Wide Range

Abstract Magnetic resonance imaging (MRI) is a widely used imaging modality to evaluate brain disorders. MRI generates huge volumes of data, which consist of a sequence of scans taken at different instances of time. As the presence of brain disorders has to be evaluated on all magnetic resonance (MR) sequences, manual brain disorder detection becomes a tedious process and is prone to inter- and intra-rater errors. A technique for detecting abnormalities in brain MRI using template matching is proposed. Bias filed correction is performed on volumetric scans using N4ITK filter, followed by volumetric registration. Normalized cross-correlation template matching is used for image registration taking into account, the rotation and scaling operations. A template of abnormality is selected which is then matched in the volumetric scans, if found, the corresponding image is retrieved. Post-processing of the retrieved images is performed by the thresholding operation; the coordinates and area of the abnormality are reported. The experiments are carried out on the glioma dataset obtained from Brain Tumor Segmentation Challenge 2013 database (BRATS 2013). Glioma dataset consisted of MR scans of 30 real glioma patients and 50 simulated glioma patients. NVIDIA Compute Unified Device Architecture framework is employed in this paper, and it is found that the detection speed using graphics processing unit is almost four times faster than using only central processing unit. The average Dice and Jaccard coefficients for a wide range of trials are found to be 0.91 and 0.83, respectively.

scholarly journals Functional connectivity of fMRI using differential covariance predicts structural connectivity and behavioral reaction times

2021 ◽  
Author(s):  
Yusi Chen ◽  
Qasim Bukhari ◽  
Tiger Wutu Lin ◽  
Terrence J Sejnowski
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Resting State ◽  
Structural Connectivity ◽  
Reaction Times ◽  
Resonance Imaging ◽  
Brain Areas ◽  
Human Connectome Project ◽  
Wide Range

Recordings from resting state functional magnetic resonance imaging (rs-fMRI) reflect the influence of pathways between brain areas. A wide range of methods have been proposed to measure this functional connectivity (FC), but the lack of ''ground truth'' has made it difficult to systematically validate them. Most measures of FC produce connectivity estimates that are symmetrical between brain areas. Differential covariance (dCov) is an algorithm for analyzing FC with directed graph edges. Applied to synthetic datasets, dCov-FC was more effective than covariance and partial correlation in reducing false positive connections and more accurately matching the underlying structural connectivity. When we applied dCov-FC to resting state fMRI recordings from the human connectome project (HCP) and anesthetized mice, dCov-FC accurately identified strong cortical connections from diffusion Magnetic Resonance Imaging (dMRI) in individual humans and viral tract tracing in mice. In addition, those HCP subjects whose rs-fMRI were more integrated, as assessed by a graph-theoretic measure, tended to have shorter reaction times in several behavioral tests. Thus, dCov-FC was able to identify anatomically verified connectivity that yielded measures of brain integration causally related to behavior.

scholarly journals Design of an experimental four-camera setup for enhanced 3D surface reconstruction in microsurgery

2017 ◽  
Vol 3 (2) ◽  
pp. 539-542 ◽  
Author(s):  
Christian Marzi ◽  
Andreas Wachter ◽  
Werner Nahm
Keyword(s):  
3D Reconstruction ◽  
Reconstruction Algorithms ◽  
Camera System ◽  
Additional Information ◽  
Wide Range ◽  
Main Disadvantage ◽  
The Common ◽  
Visualization Systems ◽  
Compact Design ◽  
The Impact

AbstractFuture fully digital surgical visualization systems enable a wide range of new options. Caused by optomechanical limitations a main disadvantage of today’s surgical microscopes is their incapability of providing arbitrary perspectives to more than two observers. In a fully digital microscopic system, multiple arbitrary views can be generated from a 3D reconstruction. Modern surgical microscopes allow replacing the eyepieces by cameras in order to record stereoscopic videos. A reconstruction from these videos can only contain the amount of detail the recording camera system gathers from the scene. Therefore, covered surfaces can result in a faulty reconstruction for deviating stereoscopic perspectives. By adding cameras recording the object from different angles, additional information of the scene is acquired, allowing to improve the reconstruction. Our approach is to use a fixed four-camera setup as a front-end system to capture enhanced 3D topography of a pseudo-surgical scene. This experimental setup would provide images for the reconstruction algorithms and generation of multiple observing stereo perspectives. The concept of the designed setup is based on the common main objective (CMO) principle of current surgical microscopes. These systems are well established and optically mature. Furthermore, the CMO principle allows a more compact design and a lowered effort in calibration than cameras with separate optics. Behind the CMO four pupils separate the four channels which are recorded by one camera each. The designed system captures an area of approximately 28mm × 28mm with four cameras. Thus, allowing to process images of 6 different stereo perspectives. In order to verify the setup, it is modelled in silico. It can be used in further studies to test algorithms for 3D reconstruction from up to four perspectives and provide information about the impact of additionally recorded perspectives on the enhancement of a reconstruction.

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