Validating Nonlinear Registration to Improve Subtraction Images for Lesion Detection and Quantification in Multiple Sclerosis

2017 ◽  
Vol 28 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Vikas Kotari ◽  
Racha Salha ◽  
Dana Wang ◽  
Emily Wood ◽  
Marco Salvetti ◽  
...  
2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Nicolo’ Bruschi ◽  
Giacomo Boffa ◽  
Matilde Inglese

Abstract Magnetic resonance imaging (MRI) is essential for the early diagnosis of multiple sclerosis (MS), for investigating the disease pathophysiology, and for discriminating MS from other neurological diseases. Ultra-high-field strength (7-T) MRI provides a new tool for studying MS and other demyelinating diseases both in research and in clinical settings. We present an overview of 7-T MRI application in MS focusing on increased sensitivity and specificity for lesion detection and characterisation in the brain and spinal cord, central vein sign identification, and leptomeningeal enhancement detection. We also discuss the role of 7-T MRI in improving our understanding of MS pathophysiology with the aid of metabolic imaging. In addition, we present 7-T MRI applications in other demyelinating diseases. 7-T MRI allows better detection of the anatomical, pathological, and functional features of MS, thus improving our understanding of MS pathology in vivo. 7-T MRI also represents a potential tool for earlier and more accurate diagnosis.


2014 ◽  
Vol 115 (3) ◽  
pp. 147-161 ◽  
Author(s):  
Mariano Cabezas ◽  
Arnau Oliver ◽  
Eloy Roura ◽  
Jordi Freixenet ◽  
Joan C. Vilanova ◽  
...  

2006 ◽  
Vol 2006 ◽  
pp. 1-10 ◽  
Author(s):  
Jinyi Qi

Statistical image reconstruction methods based on maximum a posteriori (MAP) principle have been developed for emission tomography. The prior distribution of the unknown image plays an important role in MAP reconstruction. The most commonly used prior are Gaussian priors, whose logarithm has a quadratic form. Gaussian priors are relatively easy to analyze. It has been shown that the effect of a Gaussian prior can be approximated by linear filtering a maximum likelihood (ML) reconstruction. As a result, sharp edges in reconstructed images are not preserved. To preserve sharp transitions, non-Gaussian priors have been proposed. However, their effect on clinical tasks is less obvious. In this paper, we compare MAP reconstruction with Gaussian and non-Gaussian priors for lesion detection and region of interest quantification using computer simulation. We evaluate three representative priors: Gaussian prior, Huber prior, and Geman-McClure prior. We simulate imaging a prostate tumor using positron emission tomography (PET). The detectability of a known tumor in either a fixed background or a random background is measured using a channelized Hotelling observer. The bias-variance tradeoff curves are calculated for quantification of the total tumor activity. The results show that for the detection and quantification tasks, the Gaussian prior is as effective as non-Gaussian priors.


2012 ◽  
Vol 23 (2) ◽  
pp. 528-540 ◽  
Author(s):  
Wolter L. de Graaf ◽  
Iris D. Kilsdonk ◽  
Alexandra Lopez-Soriano ◽  
Jaco J. M. Zwanenburg ◽  
Fredy Visser ◽  
...  

2007 ◽  
Vol 54 (3) ◽  
pp. 115-117 ◽  
Author(s):  
T.L. Stosic-Opincal ◽  
M. Gavrilov ◽  
S. Lavrnic ◽  
R. Milenkovic ◽  
V. Peric ◽  
...  

To estimate the relative sensitivity of MR examination for brain lesions in multiple sclerosis at 1.0 Tesla (T) and 3.0 T using identical acquisition conditions. 54 patients with multiple sclerosis were examined both at 1.0T (Siemens Impact Expert) and 3.0T (Philips Intera) using T1-weighted spin echo (T1W-SE) with and without gadolinium contrast injections, T2W SE and fluid attenuated inversion recovery (FLAIR) imaging. Images were examined independently by three experienced neuroradiologists using focal lesion counting. 3.0T scans compared with 1.0T scans demonstrate a 27.3%, increase in the number of detected contrast enhanced lesions and an 22.7% increase in the number of detected lesions on FLAIR MR tomograms. High field 3.0T MR imaging demonstrates better sensitivity in the detection of focal brain lesions in multiple sclerosis. This improvement is more apparent in contrast enhanced lesion detection and less noticeable in FLAIR detected lesions.


2020 ◽  
Vol 25 ◽  
pp. 102149 ◽  
Author(s):  
Mostafa Salem ◽  
Sergi Valverde ◽  
Mariano Cabezas ◽  
Deborah Pareto ◽  
Arnau Oliver ◽  
...  

2009 ◽  
Vol 2009 ◽  
pp. 1-13 ◽  
Author(s):  
Oren Freifeld ◽  
Hayit Greenspan ◽  
Jacob Goldberger

This paper focuses on the detection and segmentation of Multiple Sclerosis (MS) lesions in magnetic resonance (MRI) brain images. To capture the complex tissue spatial layout, a probabilistic model termed Constrained Gaussian Mixture Model (CGMM) is proposed based on a mixture of multiple spatially oriented Gaussians per tissue. The intensity of a tissue is considered a global parameter and is constrained, by a parameter-tying scheme, to be the same value for the entire set of Gaussians that are related to the same tissue. MS lesions are identified as outlier Gaussian components and are grouped to form a new class in addition to the healthy tissue classes. A probability-based curve evolution technique is used to refine the delineation of lesion boundaries. The proposed CGMM-CE algorithm is used to segment 3D MRI brain images with an arbitrary number of channels. The CGMM-CE algorithm is automated and does not require an atlas for initialization or parameter learning. Experimental results on both standard brain MRI simulation data and real data indicate that the proposed method outperforms previously suggested approaches, especially for highly noisy data.


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