scholarly journals FLAIR2 post-processing: improving MS lesion detection in standard MS imaging protocols

Author(s):  
Zrzavy Tobias ◽  
Wielandner Alice ◽  
Haider Lukas ◽  
Bartsch Sophie ◽  
Leutmezer Fritz ◽  
...  

Abstract Background Technical improvements in magnetic resonance imaging (MRI) acquisition, such as higher field strength and optimized sequences, lead to better multiple sclerosis (MS) lesion detection and characterization. Multiplication of 3D-FLAIR with 3D-T2 sequences (FLAIR2) results in isovoxel images with increased contrast-to-noise ratio, increased white–gray-matter contrast, and improved MS lesion visualization without increasing MRI acquisition time. The current study aims to assess the potential of 3D-FLAIR2 in detecting cortical/leucocortical (LC), juxtacortical (JC), and white matter (WM) lesions. Objective To compare lesion detection of 3D-FLAIR2 with state-of-the-art 3D-T2-FLAIR and 3D-T2-weighted images. Methods We retrospectively analyzed MRI scans of thirteen MS patients, showing previously noted high cortical lesion load. Scans were acquired using a 3 T MRI scanner. WM, JC, and LC lesions were manually labeled and manually counted after randomization of 3D-T2, 3D-FLAIR, and 3D-FLAIR2 scans using the ITK-SNAP tool. Results LC lesion visibility was significantly improved by 3D-FLAIR2 in comparison to 3D-FLAIR (4 vs 1; p = 0.018) and 3D-T2 (4 vs 1; p = 0.007). Comparing LC lesion detection in 3D-FLAIR2 vs. 3D-FLAIR, 3D-FLAIR2 detected on average 3.2 more cortical lesions (95% CI − 9.1 to 2.8). Comparing against 3D-T2, 3D-FLAIR2 detected on average 3.7 more LC lesions (95% CI 3.3–10.7). Conclusions 3D-FLAIR2 is an easily applicable time-sparing MR post-processing method to improve cortical lesion detection. Larger sampled studies are warranted to validate the sensitivity and specificity of 3D-FLAIR2.

2016 ◽  
Vol 23 (7) ◽  
pp. 973-981 ◽  
Author(s):  
Jan-Mendelt Tillema ◽  
Stephen D Weigand ◽  
Jay Mandrekar ◽  
Yunhong Shu ◽  
Claudia F Lucchinetti ◽  
...  

Background: The relationship between cortical lesions (CLs) and white matter lesions (WMLs) in multiple sclerosis (MS) is poorly understood. Pathological studies support a topographical association between CLs and underlying subcortical WMLs and suggest CLs may play a role in both disease initiation and progression. We hypothesized that cortical MS lesions are physically connected to white matter MS lesions via axonal connections. Objective: To assess the presence of CL-WML connectivity utilizing novel magnetic resonance imaging (MRI) methodology. Methods: In all, 28 relapsing-remitting MS patients and 25 controls received 3 T MRI scans, including double inversion recovery (DIR) for CL detection coupled with diffusion tensor imaging (DTI). CL and WML maps were created, and DTI was used to calculate inter-lesional connectivity and volumetric connectivity indices. Results: All patients showed inter-lesional WML connectivity (median 76% of WMLs connected to another WML; interquartile range (IQR), 58%–88%). On average, 52% of detected CLs per patient were connected to at least one WML (IQR, 42%–71%). Volumetric connectivity analysis showed significantly elevated cortical lesion ratios in MS patients (median, 2.3; IQR, 1.6–3.3) compared to null MS and healthy control datasets ( p < 0.001). Conclusion: These findings provide strong evidence of inter-lesional connectivity between CLs and WMLs, supporting our hypothesis of intrinsic CL-WML connectivity.


2016 ◽  
Vol 22 (9) ◽  
pp. 1174-1183 ◽  
Author(s):  
Mike P Wattjes ◽  
Martijn T Wijburg ◽  
Anke Vennegoor ◽  
Birgit I Witte ◽  
Stefan D Roosendaal ◽  
...  

Background: In natalizumab-treated multiple sclerosis (MS) patients, magnetic resonance imaging (MRI) is considered as a sensitive tool in detecting both MS disease activity and progressive multifocal leukoencephalopathy (PML). Objective: To investigate the performance of neuroradiologists using brain MRI in detecting new MS lesions and asymptomatic PML lesions and in differentiating between MS and PML lesions in natalizumab-treated MS patients. The secondary aim was to investigate interrater variability. Methods: In this retrospective diagnostic study, four blinded neuroradiologists assessed reference and follow-up brain MRI scans of 48 natalizumab-treated MS patients with new asymptomatic PML lesions ( n = 21) or new MS lesions ( n = 20) or no new lesions ( n = 7). Sensitivity and specificity for detection of new lesions in general (MS and PML lesions), MS and PML lesion differentiation, and PML detection were determined. Interrater agreement was calculated. Results: Overall sensitivity and specificity for the detection of new lesions, regardless of the nature of the lesions, were 77.4% and 89.3%, respectively; for PML-MS lesion differentiation, 74.2% and 84.7%, respectively; and for asymptomatic PML lesion detection, 59.5% and 91.7%, respectively. Interrater agreement for the tested categories was fair to moderate. Conclusion: The diagnostic performance of trained neuroradiologists using brain MRI in pharmacovigilance of natalizumab-treated MS patients is moderately good. Interrater agreement among trained readers is fair to moderate.


2018 ◽  
Vol 11 (2) ◽  
pp. 141-149
Author(s):  
Milan N. Mladenovski ◽  
Nikolay V. Vasilev ◽  
Mladen E. Ovcharov ◽  
Iliya V. Valkov

Summary Craniometric points are essential for orienting neurosurgeons in their practice. Understanding the correlations of these points help to manage any pathological lesion located on the cortical surface and subcortically. The brain sulci and gyri should be identified before craniotomy. It is difficult to identify these anatomical structures intraoperatively (after craniotomy) with precision. The main purpose of this study was to collect as much information as possible from the literature and our clinical practice in order to facilitate the placement of craniotomies without using modern neuronavigation systems. Operative reports from the last five years on cranial operations for cortical and subcortical lesions were reviewed. All the craniotomies had been planned, using four methods: detection of craniometric points, computed tomography (CT) scans/topograms, magnetic resonance imaging (MRI) scans/topograms, and intraoperative real-time ultrasonography (USG). Retrospectively, we analyzed 295 cranial operations. Our analysis showed that operating on for cortical lesions, we had frequently used the first and the second method mentioned above (118 patients), while in cases of subcortical lesions, we had used craniometric points, MRI scans/topograms and intraoperative real-time USG as methods of neuronavigation (177 patients). These results show that craniometric points are essential in both neurosurgical procedures.


Author(s):  
Sally Mohamed Shaaban ◽  
Azza Elmongui Elmongui ◽  
Ahmed Abdel Khalek Abdel Razek ◽  
Tamer Mohamed Belal

Abstract Background Multiple sclerosis is a chronic inflammatory disease affecting both white and gray matters of the central nervous system. It has been approved that the degree of gray matter involvement is closely associated with the degree of physical disability and the extent of cognitive impairment. Thus, it is necessary to incorporate widely available simple methods for neurocognitive evaluation and gray matter detection in the periodic assessment of MS patients that will influence treatment decisions. Objectives To assess the correlation of cortical lesions of multiple sclerosis (MS) at double inversion recovery (DIR) with cognition screening scores Methods This study was conducted on 30 patients with MS with an average age of 31.3±13.6 years. All of them underwent MRI and clinical assessment with the calculation of Expanded Disability Status Scale (EDSS), Montreal Cognitive Assessment (MoCA), and Symbol Digit Modality Test (SDMT) scores. The image analysis was performed by 2 reviewers for cortical lesion number, shape, and subtypes, and total lesion load. Results Both MoCA and SDMT scales had a significant inverse correlation with cortical lesions number (r=− 0.68, − 0.72) respectively and total lesion load (r=− 0.53, − 0.65) respectively. Besides, there was a significant inverse correlation between the MoCA test, varied cortical subtypes: leukocortical, juxtacortical, and intracortical subtypes (r = − 0.63, − 0.56, − 0.52) respectively, and different cortical lesion shapes: oval, wedge, and curvilinear shaped (r = − 0.62, − 0.69, − 0.49) respectively. As well, the SDMT scale showed a significant inverse correlation with varied cortical subtypes: intracortical, leukocortical, and juxtacortical subtypes (r = − 0.63, − 0.61, − 0.57) respectively, and different cortical lesion shapes: oval, curvilinear, and wedge shaped (r = − 0.61, − 0.59, − 0.46) respectively. Interestingly, there was an excellent inter-observer correlation of cortical lesion number (r = 0.96), total lesion load (r = 0.95), subtypes of cortical lesion (r = 0.94), and cortical lesion shapes (r = 0.77). Conclusion We concluded that DIR can detect cortical lesions of MS, and MRI findings were well-correlated with cognitive dysfunction in these patients.


Author(s):  
Nguyen Linh-Trung ◽  
Truong Minh-Chinh ◽  
Tan Tran-Duc ◽  
Ha Vu Le ◽  
Minh Ngoc Do

Fast image acquisition in magnetic resonance imaging (MRI) is important, due to the need to find ways that help relieve patient’s stress during MRI scans. Methods for fast MRI have been proposed, most notably among them are pMRI (parallel MRI), SWIFT (SWeep Imaging with Fourier Transformation), and compressed sensing (CS) based MRI. Although it promises to significantly reduce acquisition time, applying CS to MRI leads to difficulties with hardware design because of the randomness nature of the measurement matrix used by the conventional CS methods. In this paper, we propose a novel method that combines the above-mentioned three approaches for fast MRI by designing a compound measurement matrix from a series of single measurement matrices corresponding to pMRI, SWIFT, and CS. In our method, the CS measurement matrix is designed to be deterministic via chaotic systems. This chaotic compressed sensing (CCS) measurement matrix, while retaining most features of the random CS matrix, is simpler to realize in hardware. Several compound measurement matrices have been constructed and examined in this work, including CCS-MRI, CCS-pMRI, CCS-SWIFT, and CCS-pSWIFT. Simulation results showed that the proposed method allows an increase in the speed of the MRI acquisition process while not compromising the quality of the acquired MR images.


2011 ◽  
Vol 17 (10) ◽  
pp. 1202-1210 ◽  
Author(s):  
Alexandra Seewann ◽  
Hugo Vrenken ◽  
Evert-Jan Kooi ◽  
Paul van der Valk ◽  
Dirk L Knol ◽  
...  

Background: Cortical lesions (CLs) occur frequently in multiple sclerosis (MS), but only few CLs are observed on conventional magnetic resonance imaging (MRI). Why some CLs are visible and others are not is currently unknown. Here, we investigated whether CLs that are visible on conventional MRI differ from MRI-invisible CLs in terms of underlying histopathology and quantitative MRI (qMRI) measures. Methods: A total of 16 brain slices from 10 patients with chronic MS were analysed histopathologically and with conventional and qMRI. A region-of-interest approach was used to compare MRI-visible CLs with MRI-invisible CLs. Results: Although under-powering cannot be completely excluded in this study, MRI-visible CLs did not seem to differ from MRI-invisible CLs in terms of histopathology or qMRI measures. They were, however, significantly larger than their invisible counterparts (mean 13.3 ± 1.7 mm2 versus 6.9 ± 1.3 mm2; p = 0.001). Furthermore, the number of MRI-visible lesions correlated with the overall number of CLs in the brain slice ( r = 0.96, p < 0.01) and with the overall percentage of demyelination ( r = 0.78, p < 0.01) per hemispheric brain slice. Conclusion: MRI visibility of CLs is determined by lesion size, and not by any distinctive underlying pathology. Visible CLs are associated with a higher total cortical lesion load, which suggests that when CLs in patients with MS become detectable on MRI, they merely represent ‘the tip of the pathological iceberg’.


Author(s):  
Abdullah Dhaifallah Almutairi ◽  
Hasyma Abu Hassan ◽  
Subapriya Suppiah ◽  
Othman I. Alomair ◽  
Abdulbaset Alshoaibi ◽  
...  

Abstract Background Magnetic resonance imaging (MRI) is one of the diagnostic imaging modalities employing in lesion detection in neurological disorders such as multiple sclerosis (MS). Advances in MRI techniques such as double inversion recovery (DIR) made it more sensitive to distinguish lesions in the brain. To investigate the lesion load on different anatomical regions of the brain with MS using DIR, fluid attenuated inversion recovery (FLAIR) and T2-weighted imaging (T2WI) sequences. A total of 97 MS patients were included in our retrospective study, confirmed by neurologist. The patients were randomly selected from the major hospital in Saudi Arabia. All images were obtained using 3T Scanner (Siemens Skyra). The images from the DIR, FLAIR, and T2WI sequence were compared on axial planes with identical anatomic position and the number of lesions was assigned to their anatomical region. Results Comparing the lesion load measurement at various brain anatomical regions showed a significant difference among those three methods (p < 0.05). Conclusion DIR is a valuable MRI sequence for better delineation, greater contrast measurements and the increasing total number of MS lesions in MRI, compared with FLAIR, and T2WI and DIR revealed more intracortical lesions as well; therefore, in MS patients, it is recommended to add DIR sequence in daily routine imaging sequences.


2021 ◽  
pp. 135245852110298
Author(s):  
Piet M Bouman ◽  
Victor IJ Strijbis ◽  
Laura E Jonkman ◽  
Hanneke E Hulst ◽  
Jeroen JG Geurts ◽  
...  

Background: Cortical lesions are highly inconspicuous on magnetic resonance imaging (MRI). Double inversion recovery (DIR) has a higher sensitivity than conventional clinical sequences (i.e. T1, T2, FLAIR) but is difficult to acquire, leading to overseen cortical lesions in clinical care and clinical trials. Objective: To evaluate the usability of artificially generated DIR (aDIR) images for cortical lesion detection compared to conventionally acquired DIR (cDIR). Methods: The dataset consisted of 3D-T1 and 2D-proton density (PD) T2 images of 73 patients (49RR, 20SP, 4PP) at 1.5 T. Using a 4:1 train:test-ratio, a fully convolutional neural network was trained to predict 3D-aDIR from 3D-T1 and 2D-PD/T2 images. Randomized blind scoring of the test set was used to determine detection reliability, precision and recall. Results: A total of 626 vs 696 cortical lesions were detected on 15 aDIR vs cDIR images (intraclass correlation coefficient (ICC) = 0.92). Compared to cDIR, precision and recall were 0.84 ± 0.06 and 0.76 ± 0.09, respectively. The frontal and temporal lobes showed the largest differences in discernibility. Conclusion: Cortical lesions can be detected with good reliability on artificial DIR. The technique has potential to broaden the availability of DIR in clinical care and provides the opportunity of ex post facto implementation of cortical lesions imaging in existing clinical trial data.


1997 ◽  
Vol 3 (6) ◽  
pp. 382-384
Author(s):  
M. Rovaris ◽  
MP Sormanis ◽  
MA Rocca ◽  
G. Comi ◽  
M. Filippi

This study aimed at evaluating the influence of a different slice orientation on brain magnetic resonance imaging (MRI) lesion load in multiple sclerosis (MS). Fifteen MS patients were scanned obtaining both axial and sagittal conventional spin echo (24 slices; TR 2400, TE 30/80) brain MRI. The total lesion load (TLL) was assessed twice for each scan, using a semi-automated local thresholding technique and the same marked hardcopies. The mean TLL was 22734 mm3 for axial and 22003 mm3 for sagittal scans. The mean intra-observer coefficient of variation (COV) was 4.65% for the axial acquisitions and 4.52% for the sagittal acquisitions. This difference was not statistically significant (one-way ANOVA, P> 0.1). The lesion load was significantly higher from axial MRI as compared to the intra-observer variability (two-way ANOVA, P =0.01), but the fluctuations around this average difference between axial and sagittal scan TLL were significantly large (test for interaction, P < 0.00I). Our data indicate that the use of sagittal conventional MRI scans does not seem to be worthwhile for the quantitative assessment of lesion load in MS patients.


2013 ◽  
Vol 20 (2) ◽  
pp. 227-233 ◽  
Author(s):  
Niraj Mistry ◽  
Rasha Abdel-Fahim ◽  
Olivier Mougin ◽  
Christopher Tench ◽  
Penny Gowland ◽  
...  

Background:Degeneration of central nervous system normal appearing white matter (NAWM) underlies disability and progression in multiple sclerosis (MS). Axon loss typifies NAWM degeneration.Objective:The objective of this paper is to assess correlation between cortical lesion load and magnetisation transfer ratio (MTR) of the NAWM in MS. This was in order to test the hypothesis that cortical lesions cause NAWM degeneration.Methods:Nineteen patients with MS underwent 7 Tesla magnetisation-prepared-rapid-acquisition-gradient-echo (MPRAGE), and magnetisation transfer ratio (MTR) brain magnetic resonance imaging (MRI). Cortical lesions were identified using MPRAGE and MTR images of cortical ribbons. White matter lesions (WMLs) were segmented using MPRAGE images. WML maps were subtracted from white matter volumes to produce NAWM masks. Pearson correlation was calculated for NAWM MTR vs cortical lesion load, and WML volumes.Results:Cortical lesion volumes and counts all had significant correlation with NAWM mean MTR. The strongest correlation was with cortical lesion volumes obtained using MTR images ( r = −0.6874, p = 0.0006). WML volume had no significant correlation with NAWM mean MTR ( r = −0.08706, p = 0.3615).Conclusion:Our findings are consistent with the hypothesis that cortical lesions cause NAWM degeneration. This implicates cortical lesions in the pathogenesis of NAWM axon loss, which underpins long-term disability and progression in MS.


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