scholarly journals Inter- and Intra-Scanner Variability of Automated Brain Volumetry on Three Magnetic Resonance Imaging Systems in Alzheimer’s Disease and Controls

2021 ◽  
Vol 13 ◽  
Author(s):  
Mandy Melissa Jane Wittens ◽  
Gert-Jan Allemeersch ◽  
Diana Maria Sima ◽  
Maarten Naeyaert ◽  
Tim Vanderhasselt ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Imaging System ◽  
Brain Mri ◽  
Intraclass Correlation ◽  
Imaging Systems ◽  
Resonance Imaging ◽  
Brain Volumes ◽  
Brain Volumetry ◽  
Multiple Imaging

Magnetic Resonance Imaging (MRI) has become part of the clinical routine for diagnosing neurodegenerative disorders. Since acquisitions are performed at multiple centers using multiple imaging systems, detailed analysis of brain volumetry differences between MRI systems and scan-rescan acquisitions can provide valuable information to correct for different MRI scanner effects in multi-center longitudinal studies. To this end, five healthy controls and five patients belonging to various stages of the AD continuum underwent brain MRI acquisitions on three different MRI systems (Philips Achieva dStream 1.5T, Philips Ingenia 3T, and GE Discovery MR750w 3T) with harmonized scan parameters. Each participant underwent two subsequent MRI scans per imaging system, repeated on three different MRI systems within 2 h. Brain volumes computed by icobrain dm (v5.0) were analyzed using absolute and percentual volume differences, Dice similarity (DSC) and intraclass correlation coefficients, and coefficients of variation (CV). Harmonized scans obtained with different scanners of the same manufacturer had a measurement error closer to the intra-scanner performance. The gap between intra- and inter-scanner comparisons grew when comparing scans from different manufacturers. This was observed at image level (image contrast, similarity, and geometry) and translated into a higher variability of automated brain volumetry. Mixed effects modeling revealed a significant effect of scanner type on some brain volumes, and of the scanner combination on DSC. The study concluded a good intra- and inter-scanner reproducibility, as illustrated by an average intra-scanner (inter-scanner) CV below 2% (5%) and an excellent overlap of brain structure segmentation (mean DSC > 0.88).

scholarly journals 4H Leukodystrophy: A Brain Magnetic Resonance Imaging Scoring System

2017 ◽  
Vol 48 (03) ◽  
pp. 152-160 ◽  
Author(s):  
Suzanne Vrij-van den Bos ◽  
Janna Hol ◽  
Roberta La Piana ◽  
Inga Harting ◽  
Adeline Vanderver ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Scoring System ◽  
Hypogonadotropic Hypogonadism ◽  
Brain Mri ◽  
Intraclass Correlation ◽  
Brain Magnetic Resonance Imaging ◽  
Brain Regions ◽  
Resonance Imaging ◽  
Mri Scans

4H (hypomyelination, hypodontia and hypogonadotropic hypogonadism) leukodystrophy (4H) is an autosomal recessive hypomyelinating white matter (WM) disorder with neurologic, dental, and endocrine abnormalities. The aim of this study was to develop and validate a magnetic resonance imaging (MRI) scoring system for 4H. A scoring system (0–54) was developed to quantify hypomyelination and atrophy of different brain regions. Pons diameter and bicaudate ratio were included as measures of cerebral and brainstem atrophy, and reference values were determined using controls. Five independent raters completed the scoring system in 40 brain MRI scans collected from 36 patients with genetically proven 4H. Interrater reliability (IRR) and correlations between MRI scores, age, gross motor function, gender, and mutated gene were assessed. IRR for total MRI severity was found to be excellent (intraclass correlation coefficient: 0.87; 95% confidence interval: 0.80–0.92) but varied between different items with some (e.g., myelination of the cerebellar WM) showing poor IRR. Atrophy increased with age in contrast to hypomyelination scores. MRI scores (global, hypomyelination, and atrophy scores) significantly correlated with clinical handicap (p < 0.01 for all three items) and differed between the different genotypes. Our 4H MRI scoring system reliably quantifies hypomyelination and atrophy in patients with 4H, and MRI scores reflect clinical disease severity.

Magnetic resonance imaging findings and its association to electroencephalogram in children with partial epilepsy (Preprint)

2020 ◽  
Author(s):  
Huynh Quang Huy
Keyword(s):  
Magnetic Resonance Imaging ◽  
Preschool Children ◽  
Magnetic Resonance ◽  
Brain Mri ◽  
Partial Epilepsy ◽  
Small Sample ◽  
Normal Brain ◽  
Resonance Imaging ◽  
Normal Children ◽  
Eeg Abnormalities

BACKGROUND It is important to identify the neuroimaging features that are associated with partial epilepsy in preschool children. Advances in technology recently to localize focal epileptogenic lesions, especially that of high-resolution structural imaging with magnetic resonance imaging (MRI). The recommendation that electroencephalography (EEG) should be gold criteria and that M.R.I should be optional has been questioned. OBJECTIVE The present study aims to to explore the brain lesions on MRI and its association to electroencephalogram in children with partial epilepsy. METHODS The present study was conducted among 112 preschool children with history of partial seizures. All patients underwent EEG and brain MRI. The epileptogenic lesions were identified on the basis of the signal intensities and morphological abnormalities seen on MRI. The correlation between MRI and EEG abnormalities was explored using a chi-square test. RESULTS Abnormal MRI were found in 34.8% (n = 39) of the sample. The EEG and MRI agreed with respect to classify into abnormal or normal in 48.2% (n = 54). Of the 27 patients with a normal EEG, six (22.2%) were seen to have an abnormal MRI. CONCLUSIONS A number of MRI abnormalities was found in our study of otherwise normal children, although the correlation between these results was not clear. Follow-up of these children will help us identify the important abnormalities. Despite of small sample, our results showed that a normal E.E.G findings does not predict a normal brain MRI in children with partial epilepsy.

5377679 Magnetic resonance imaging system

1995 ◽  
Vol 13 (6) ◽  
pp. VI-VII
Author(s):  
Machida Yoshio ◽  
Hatanaka Masahiko ◽  
Kitane Shinichi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Imaging System ◽  
Magnetic Resonance Imaging System ◽  
Resonance Imaging

scholarly journals RF-Induced Heating of Various Tattoos at Magnetic Resonance Imaging Systems

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 100951-100961
Author(s):  
Shahzeb Hayat ◽  
Youngdae Cho ◽  
Sukhoon Oh ◽  
Hyoungsuk Yoo
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Imaging Systems ◽  
Resonance Imaging

Pontine ataxic hemiparesis studied by a high-resolution magnetic resonance imaging system

1987 ◽  
Vol 21 (2) ◽  
pp. 204-207 ◽  
Author(s):  
Hidehiko Nabatame ◽  
Hidenao Fukuyama ◽  
Ichiro Akiguchi ◽  
Masakuni Kameyama ◽  
Kazumasa Nishimura ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Imaging System ◽  
Magnetic Resonance Imaging System ◽  
Resonance Imaging ◽  
Ataxic Hemiparesis

5432449 Test apparatus for magnetic resonance imaging systems

1995 ◽  
Vol 13 (7) ◽  
pp. XV-XVI
Author(s):  
E Ferut John ◽  
W Belt Kenneth ◽  
Phillip Steen ◽  
Johnny Parham ◽  
John Wolak ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Imaging Systems ◽  
Test Apparatus ◽  
Resonance Imaging

scholarly journals Numerical Analysis of a Flexible Dual Loop Coil and its Experimental Validation for pre-Clinical Magnetic Resonance Imaging of Rodents at 7 T

2016 ◽  
Vol 16 (6) ◽  
pp. 294-299 ◽  
Author(s):  
S. Solis-Najera ◽  
F. Vazquez ◽  
R. Hernandez ◽  
O. Marrufo ◽  
A.O. Rodriguez
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Imaging System ◽  
Ex Vivo ◽  
Small Animal ◽  
Magnetic Resonance Imaging System ◽  
External Diameter ◽  
Rf Coil ◽  
Resonance Imaging ◽  
Clinical Magnetic Resonance Imaging

Abstract A surface radio frequency coil was developed for small animal image acquisition in a pre-clinical magnetic resonance imaging system at 7 T. A flexible coil composed of two circular loops was developed to closely cover the object to be imaged. Electromagnetic numerical simulations were performed to evaluate its performance before the coil construction. An analytical expression of the mutual inductance for the two circular loops as a function of the separation between them was derived and used to validate the simulations. The RF coil is composed of two circular loops with a 5 cm external diameter and was tuned to 300 MHz and 50 Ohms matched. The angle between the loops was varied and the Q factor was obtained from the S11 simulations for each angle. B1 homogeneity was also evaluated using the electromagnetic simulations. The coil prototype was designed and built considering the numerical simulation results. To show the feasibility of the coil and its performance, saline-solution phantom images were acquired. A correlation of the simulations and imaging experimental results was conducted showing a concordance of 0.88 for the B1 field. The best coil performance was obtained at the 90° aperture angle. A more realistic phantom was also built using a formaldehyde-fixed rat phantom for ex vivo imaging experiments. All images showed a good image quality revealing clearly defined anatomical details of an ex vivo rat.

Yield of Brain Magnetic Resonance Imaging in Epilepsy Diagnosis from 1998 to 2020: A Large Retrospective Cohort Study

2021 ◽  
Author(s):  
Tomer Stern ◽  
Liora Kornreich ◽  
Hadassa Goldberg
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Focal Epilepsy ◽  
Brain Mri ◽  
Brain Magnetic Resonance Imaging ◽  
Infantile Spasms ◽  
Mesial Temporal Sclerosis ◽  
Resonance Imaging ◽  
Brain Abnormalities ◽  
Epilepsy Diagnosis

Abstract Background We aimed to find the clinical significance of brain abnormalities on magnetic resonance imaging (MRI) in epilepsy and the lateralization of these findings with electroencephalogram (EEG). Methods We retrospectively analyzed the results of all EEGs and brain MRIs of 600 consecutive epilepsy patients from 1998 to 2020. Results Data were available for 563 cases (267 females). Ninety percent of the patients were 18 years old or younger. A total of 345 patients (61.3%) had focal epilepsy, 180 (32%), generalized, and 38 (6.7%), inconclusive. In 187 (33.2%), the first MRI was abnormal and in 81 (out of 108 repeated MRI), the second was pathological. The most frequent brain abnormalities were cortical dysplasia in 41 (18.1%), other structural abnormalities in 25 (11%), various phacomatoses in 23 (10.1%), and mesial temporal sclerosis in 17 (7.5%). Among 226 patients with abnormal MRI, 171 (75.6%) had focal epilepsy when compared with 36 (15.9%) with generalized epilepsy (p <0.001). In 121 patients (53.5%), the result of the abnormal MRI contributed significantly to the understanding of the epilepsy etiology. The side of abnormality was lateralized to the EEG focus in 120 cases (53%); in 10/15 cases with infantile spasms (66%), MRI was significantly abnormal. In 33, in whom the first MRI was normal, a second MRI revealed a significant abnormality. Conclusion Brain MRI is an important tool in epilepsy diagnosis, mainly in focal seizures and infantile spasms. A repeat MRI is mandatory in intractable focal cases to improve the yield of this test.

U mỡ trong xương bướm: một trường hợp hiếm gặp

2021 ◽  
Author(s):  
Thu Hien Trinh Thi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Rare Case ◽  
Imaging Techniques ◽  
Brain Mri ◽  
Brain Magnetic Resonance Imaging ◽  
Sphenoid Bone ◽  
Resonance Imaging ◽  
Large Tumor ◽  
Intraosseous Lipoma

TÓM TẮT U mỡ trong xương là khối u lành tính hiếm gặp, thường gặp ở các xương dẹt, hiếm gặp ở xương nền sọ, đặc biệt là xương bướm. Trong đa số các trường hợp, u mỡ trong xương bướm thường được phát hiện tình cờ qua chụp cắt lớp vi tinh (CLVT) hoặc cộng hưởng từ (CHT) sọ não. Đây là một khối u phát triển chậm, ít gây ra triệu chứng, một số trường hợp gây triệu chứng khi khối u to chèn ép vào cấu trúc lân cận như tuyến yên hoặc dây thần kinh thị. Trong bài này, chúng tôi báo cáo một trường hợp u mỡ trong xương bướm không triệu chứng được phát hiện tình cờ và được chẩn đoán dựa vào phim chụp cộng hưởng từ sọ não. Bệnh nhân được khuyến nghị theo dõi định kỳ bằng cộng hưởng từ mà không phải tiến hành bất kỳ phương pháp điều trị nào. Từ khóa: U mỡ, xương bướm, MRI, cộng hưởng từ sọ não, chẩn đoán hình ảnh. ABSTRACT INTRAOSSEOUS LIPOMA OF SPHENOID BONE: A RARE CASE REVIEW Intraosseous lipoma is very rare, usually benign tumor of flat bones. The incidence of an intraosseous lipomalocated basal skull bones is extremely rare, especially in sphenoid bone. Radiological imaging techniques such as magnetic resonance imaging (MRI) and computed tomography (CT) are used to detect the intraosseous lipoma by accident. These tumors are slow growing and usually asymptomatic, in some cases causing symptoms when the large tumor presses on nearby structures such as pituitary gland or the optic nerve. We present a rare case of lipomaof the sphenoid bone discovered incidentally with brain magnetic resonance imaging. The patient has been followed-up by magnetic resonance imaging without the need for surgery. Keywords: Intraosseous lipoma, sphenoid bone, MRI, brain MRI, diagnostic radiology

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