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Your search keyword '"Fallatah, S. M."' showing total 3 results
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3 results on '"Fallatah, S. M."'

1. Perfusion imaging in brain tumours

Author

Fallatah, S. M. Y., Golay, X., and Jäger, R.

Subjects
612.8
Abstract

Perfusion-weighted magnetic resonance imaging (MRI) is a widely used technique to study the blood perfusion to brain tumours. It provides information on tissue hemodynamic changes and increases the accuracy of anatomical MRI in the diagnosis of brain tumours. Numerous perfusion MRI techniques have been devised to measure various perfusion-related parameters in the last 30 years. There are two primary perfusion MRI approaches those with exogenous contrast agent including dynamic susceptibility contrast MRI (DSC-MRI) and dynamic contrast enhanced MRI (DCE-MRI); and those without exogenous contrast agent, including arterial spin labelling (ASL). Despite the substantial development of perfusion MRI, the technique still encounters significant challenges. Many limitations and drawbacks have been already pointed out in the literature, yet more work remains to be done to address these limitations. A major issue with these techniques is the lack of technical standardisation in acquisition and post-processing methods. Furthermore, high-quality images cannot be achieved without attention to quality control. This thesis focuses on perfusion MRI in brain tumours with a great deal of attention to reproducibility, quality control and standardisation.

Published
2016

3. A visual quality control scale for clinical arterial spin labeling images

Author

Fallatah, S. M., Pizzini, F. B., Gómez-Ansón, Beatriz, Magerkurth, J., De Vita, E., Bisdas, S., Jäger, Hans Rolf, Mutsaerts, H. J. M. M., Golay, X., and Universitat Autònoma de Barcelona

Subjects
Magnetic resonance imaging, Quality control, Perfusion imaging, Arterial spin labelling
Abstract

Image-quality assessment is a fundamental step before clinical evaluation of magnetic resonance images. The aim of this study was to introduce a visual scoring system that provides a quality control standard for arterial spin labeling (ASL) and that can be applied to cerebral blood flow (CBF) maps, as well as to ancillary ASL images. The proposed image quality control (QC) system had two components: (1) contrast-based QC (cQC), describing the visual contrast between anatomical structures; and (2) artifact-based QC (aQC), evaluating image quality of the CBF map for the presence of common types of artifacts. Three raters evaluated cQC and aQC for 158 quantitative signal targeting with alternating radiofrequency labelling of arterial regions (QUASAR) ASL scans (CBF, T1 relaxation rate, arterial blood volume, and arterial transient time). Spearman correlation coefficient (r), intraclass correlation coefficients (ICC), and receiver operating characteristic analysis were used. Intra/inter-rater agreement ranged from moderate to excellent; inter-rater ICC was 0.72 for cQC, 0.60 for aQC, and 0.74 for the combined QC (cQC + aQC). Intra-rater ICC was 0.90 for cQC; 0.80 for aQC, and 0.90 for the combined QC. Strong correlations were found between aQC and CBF maps quality (r = 0.75), and between aQC and cQC (r = 0.70). A QC score of 18 was optimal to discriminate between high and low quality clinical scans. The proposed QC system provided high reproducibility and a reliable threshold for discarding low quality scans. Future research should compare this visual QC system with an automatic QC system.

Published
2021

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