scholarly journals Increased Brain Volumetric Measurement Precision from Multi-Site 3D T1-weighted 3T Magnetic Resonance Imaging by Correcting Geometric Distortions

2021 ◽  
Author(s):  
Nuwan D. Nanayakkara ◽  
Stephen R. Arnott ◽  
Christopher J.M. Scott ◽  
Igor Solovey ◽  
Shuai Liang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Measurement Precision ◽  
Distortion Correction ◽  
Geometric Distortion ◽  
Resonance Imaging ◽  
Volumetric Measurement ◽  
Distance Measurements ◽  
Geometric Distortions ◽  
One Year ◽  
Volumetric Measurements

Magnetic resonance imaging (MRI) scanner-specific geometric distortions may contribute to scanner induced variability and decrease volumetric measurement precision for multi-site studies. The purpose of this study was to determine whether geometric distortion correction increases the precision of brain volumetric measurements in a multi-site multi-scanner study. Geometric distortion variation was quantified over a one-year period at 10 sites using the distortion fields estimated from monthly 3D T1-weighted MRI geometrical phantom scans. The variability of volume and distance measurements were quantified using synthetic volumes and a standard quantitative MRI (qMRI) phantom. The effects of geometric distortion corrections on MRI derived volumetric measurements of the human brain were assessed in two subjects scanned on each of the 10 MRI scanners and in 150 subjects with cerebrovascaular disease (CVD) acquired across imaging sites. Geometric distortions were found to vary substantially between different MRI scanners but were relatively stable on each scanner over a one-year interval. Geometric distortions varied spatially, increasing in severity with distance from the magnet isocenter. In measurements made with the qMRI phantom, the geometric distortion correction decreased the standard deviation of volumetric assessments by 35% and distance measurements by 42%. The average coefficient of variance decreased by 16% in gray matter and white matter volume estimates in the two subjects scanned on the 10 MRI scanners. Geometric distortion correction using an up-to-date correction field is recommended to increase precision in volumetric measurements made from MRI images.

Compensation of Geometric Distortion Effects on Intraoperative Magnetic Resonance Imaging for Enhanced Visualization in Image-guided Neurosurgery

2008 ◽  
Vol 62 (suppl_1) ◽  
pp. ONS209-ONS216 ◽  
Author(s):  
Neculai Archip ◽  
Olivier Clatz ◽  
Stephen Whalen ◽  
Simon P. DiMaio ◽  
Peter M. Black ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Distortion Correction ◽  
Intraoperative Mri ◽  
Geometric Distortion ◽  
Nonrigid Registration ◽  
Resonance Imaging ◽  
Distortion Compensation ◽  
Rigid Registration ◽  
Image Guided

Abstract Objective: Preoperative magnetic resonance imaging (MRI), functional MRI, diffusion tensor MRI, magnetic resonance spectroscopy, and positron-emission tomographic scans may be aligned to intraoperative MRI to enhance visualization and navigation during image-guided neurosurgery. However, several effects (both machine- and patient-induced distortions) lead to significant geometric distortion of intraoperative MRI. Therefore, a precise alignment of these image modalities requires correction of the geometric distortion. We propose and evaluate a novel method to compensate for the geometric distortion of intraoperative 0.5-T MRI in image-guided neurosurgery. Methods: In this initial pilot study, 11 neurosurgical procedures were prospectively enrolled. The scheme used to correct the geometric distortion is based on a nonrigid registration algorithm introduced by our group. This registration scheme uses image features to establish correspondence between images. It estimates a smooth geometric distortion compensation field by regularizing the displacements estimated at the correspondences. A patient-specific linear elastic material model is used to achieve the regularization. The geometry of intraoperative images (0.5 T) is changed so that the images match the preoperative MRI scans (3 T). Results: We compared the alignment between preoperative and intraoperative imaging using 1) only rigid registration without correction of the geometric distortion, and 2) rigid registration and compensation for the geometric distortion. We evaluated the success of the geometric distortion correction algorithm by measuring the Hausdorff distance between boundaries in the 3-T and 0.5-T MRIs after rigid registration alone and with the addition of geometric distortion correction of the 0.5-T MRI. Overall, the mean magnitude of the geometric distortion measured on the intraoperative images is 10.3 mm with a minimum of 2.91 mm and a maximum of 21.5 mm. The measured accuracy of the geometric distortion compensation algorithm is 1.93 mm. There is a statistically significant difference between the accuracy of the alignment of preoperative and intraoperative images, both with and without the correction of geometric distortion (P < 0.001). Conclusion: The major contributions of this study are 1) identification of geometric distortion of intraoperative images relative to preoperative images, 2) measurement of the geometric distortion, 3) application of nonrigid registration to compensate for geometric distortion during neurosurgery, 4) measurement of residual distortion after geometric distortion correction, and 5) phantom study to quantify geometric distortion.

497 Influence of different inhomogeneities on the geometric distortion in stereotactic magnetic resonance imaging

2005 ◽  
Vol 76 ◽  
pp. S213
Author(s):  
J. Novotny ◽  
J. Vymaza ◽  
P. Chuda ◽  
D. Urgosik ◽  
J. Novotny ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Geometric Distortion ◽  
Resonance Imaging

scholarly journals Longitudinal Motor Functional Outcomes and Magnetic Resonance Imaging Patterns of Muscle Involvement in Upper Limbs in Duchenne Muscular Dystrophy

Medicina ◽  
2021 ◽  
Vol 57 (11) ◽  
pp. 1267
Author(s):  
Claudia Brogna ◽  
Lara Cristiano ◽  
Tommaso Verdolotti ◽  
Giulia Norcia ◽  
Luana Ficociello ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Duchenne Muscular Dystrophy ◽  
Magnetic Resonance ◽  
Muscular Dystrophy ◽  
Resonance Imaging ◽  
Muscle Mri ◽  
Functional Changes ◽  
One Year ◽  
Age Range

Background and Objectives: The aim of this study was to evaluate longitudinal changes using both upper limb muscle Magnetic Resonance Imaging (MRI) at shoulder, arm and forearm levels and Performance of upper limb (PUL) in ambulant and non-ambulant Duchenne Muscular Dystrophy (DMD) patients. We also wished to define whether baseline muscle MRI could help to predict functional changes after one year. Materials and Methods: Twenty-seven patients had both baseline and 12month muscle MRI and PUL assessments one year later. Results: Ten were ambulant (age range 5–16 years), and 17 non ambulant (age range 10–30 years). Increased abnormalities equal or more than 1.5 point on muscle MRI at follow up were found on all domains: at shoulder level 12/27 patients (44%), at arm level 4/27 (15%) and at forearm level 6/27 (22%). Lower follow up PUL score were found in 8/27 patients (30%) at shoulder level, in 9/27 patients (33%) at mid-level whereas no functional changes were found at distal level. There was no constant association between baseline MRI scores and follow up PUL scores at arm and forearm levels but at shoulder level patients with moderate impairment on the baseline MRI scores between 16 and 34 had the highest risk of decreased function on PUL over a year. Conclusions: Our results confirmed that the integrated use of functional scales and imaging can help to monitor functional and MRI changes over time.

scholarly journals Diffusion-weighted Renal MRI at 9.4 Tesla Using RARE to Improve Anatomical Integrity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Joāo dos Santos Periquito ◽  
Katharina Paul ◽  
Till Huelnhagen ◽  
Min-Chi Ku ◽  
Yiyi Ji ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Tissue Characterization ◽  
Kidney Diseases ◽  
Geometric Distortion ◽  
Fast Spin Echo ◽  
Single Shot ◽  
Resonance Imaging ◽  
Rapid Acquisition ◽  
Diffusion Weighted

AbstractDiffusion-weighted magnetic resonance imaging (DWI) is a non-invasive imaging technique sensitive to tissue water movement. By enabling a discrimination between tissue properties without the need of contrast agent administration, DWI is invaluable for probing tissue microstructure in kidney diseases. DWI studies commonly make use of single-shot Echo-Planar Imaging (ss-EPI) techniques that are prone to suffering from geometric distortion. The goal of the present study was to develop a robust DWI technique tailored for preclinical magnetic resonance imaging (MRI) studies that is free of distortion and sensitive to detect microstructural changes. Since fast spin-echo imaging techniques are less susceptible to B0 inhomogeneity related image distortions, we introduced a diffusion sensitization to a split-echo Rapid Acquisition with Relaxation Enhancement (RARE) technique for high field preclinical DWI at 9.4 T. Validation studies in standard liquids provided diffusion coefficients consistent with reported values from the literature. Split-echo RARE outperformed conventional ss-EPI, with ss-EPI showing a 3.5-times larger border displacement (2.60 vs. 0.75) and a 60% higher intra-subject variability (cortex = 74%, outer medulla = 62% and inner medulla = 44%). The anatomical integrity provided by the split-echo RARE DWI technique is an essential component of parametric imaging on the way towards robust renal tissue characterization, especially during kidney disease.

scholarly journals Sexual Dimorphism in Laryngeal Volumetric Measurements Using Magnetic Resonance Imaging

2019 ◽  
Vol 99 (2) ◽  
pp. 132-136 ◽  
Author(s):  
Abdul-Latif Hamdan ◽  
Elie Khalifee ◽  
Georges Ziade ◽  
Sahar Semaan
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Statistical Significance ◽  
Resonance Imaging ◽  
Men And Women ◽  
Mean Width ◽  
Significant Difference ◽  
The Mean ◽  
The Right ◽  
Volumetric Measurements

The objective of this study is to investigate the dimensional and volumetric measurements in the thyroarytenoid (TA) muscle in men and women using magnetic resonance imaging (MRI). The hypothesis is that there is a gender-related difference in these measurements. A retrospective chart review of 76 patients who underwent MRI of the neck at the American University of Beirut Medical Center was conducted. The dimension and volume of the right and left TA muscle were measured on axial and coronal planes short tau inversion recovery images. Male and female groups were compared with respect to demographic data and MRI findings using parametric and nonparametric tests. The mean length of the thyro-arytenoid muscle in males was larger than that in females on the right (males 2.44 [0.29] cm vs females 1.70 [0.22] cm) and on the left (males 2.50 [0.28] cm vs females 1.72 [0.24] cm) reaching statistical significance ( P < .001). The mean width of the thyro-arytenoid muscle in males was larger than that in females on the right (males 0.68 [0.13] cm vs females 0.59 [0.11] cm) and on the left (males 0.68 [0.12] cm vs females 0.57 [0.12] cm) reaching statistical significance ( P < .001). The mean height of the thyro-arytenoid muscle in males was larger than that in females on the right (males 1.05 [0.21] cm vs females 0.95 [0.12] cm) and on the left (males 1.05 [0.21] cm vs females 0.95 [0.12] cm) reaching statistical significance ( P < .01 on the right and P < .05 on the left). The volume of the thyroarytenoid muscle in males was larger than that in females on the right (males 0.86 [0.25] mL vs females 0.48 [0.15] mL) and on the left (males 0.89 [0.27] mL vs females 0.48 [0.17] mL) reaching statistical significance ( P < .001). The results of this investigation clearly indicate a significant difference in these measurements between men and women.

scholarly journals Dural Cavernous Hemangioma: An Under-recognized Lesion Mimicking Meningioma

1993 ◽  
Vol 20 (3) ◽  
pp. 230-233 ◽  
Author(s):  
R. Perry James ◽  
S. Tucker William ◽  
Chui Mario ◽  
M. Bilbao Juan
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cavernous Hemangioma ◽  
Distinct Type ◽  
Resonance Imaging ◽  
Partial Seizures ◽  
Enhancement Pattern ◽  
Signal Characteristics ◽  
Pathologic Findings ◽  
One Year ◽  
Serial Examination

ABSTRACT:We report a 77-year-old woman who presented with partial seizures and was found to have an enhancing dural-based parietal convexity mass. The lesion enlarged on serial examination by computed tomography (CT) over a one year period. The clinical features and radiologic appearance were compatible with a pre-operative diagnosis of meningioma; however, pathologic findings were typical of a dural cavernous hemangioma. Accumulating evidence suggests that these lesions are an uncommon but distinct type of vascular malformation most often arising from the cavernous sinus, tentorium, or cerebello-pontine angle. With CT, magnetic resonance imaging and angiography, these lesions can closely resemble meningioma in terms of signal characteristics, enhancement pattern, and location. This is of importance both in the practical management of meningiomas where the diagnosis is often based on radiologic studies alone, and in clinical trials where incorrect entry diagnosis should be avoided.

Cochlear patency following translabyrinthine vestibular schwannoma resection: implications for hearing rehabilitation

2019 ◽  
Vol 133 (7) ◽  
pp. 560-565
Author(s):  
V Carswell ◽  
J A Crowther ◽  
R Locke ◽  
W Taylor ◽  
G Kontorinis
Keyword(s):  
Magnetic Resonance Imaging ◽  
Vestibular Schwannoma ◽  
Time Window ◽  
Inclusion Criteria ◽  
Resonance Imaging ◽  
Hearing Rehabilitation ◽  
Translabyrinthine Approach ◽  
Complete Obliteration ◽  
One Year ◽  
Fluid Signal

AbstractObjectiveTo examine when cochlear fibrosis occurs following a translabyrinthine approach for vestibular schwannoma resection, and to determine the safest time window for potential cochlear implantation in cases with a preserved cochlear nerve.MethodsThis study retrospectively reviewed the post-operative magnetic resonance imaging scans of patients undergoing a translabyrinthine approach for vestibular schwannoma resection, assessing the fluid signal within the cochlea. Cochleae were graded based on the Isaacson et al. system (from grade 0 – no obstruction, to grade 4 – complete obliteration).ResultsThirty-nine patients fulfilled the inclusion criteria. The cochleae showed no evidence of obliteration in: 75 per cent of patients at six months, 38.5 per cent at one year and 27 per cent beyond one year. Most changes happened between 6 and 12 months after vestibular schwannoma resection, with cases of an unobstructed cochlear decreasing dramatically, from 75 per cent to 38.5 per cent, within this time.ConclusionThe progress of cochlear obliteration that occurred between 6 and 12 months following vestibular schwannoma resection indicates that the first 6 months provides a safer time window for cochlear patency.

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