Quantitative dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) measures the rate of transfer of contrast agent from the vascular space to the tissue space by fitting signal-time data to pharmacokinetic models. However, these models are very sensitive to errors in T mapping. Accurate T mapping is necessary for high quality quantitative DCE-MRI studies. This study compares magnetization prepared rapid (two) gradient echo sequence (MP2RAGE) T-mapping accuracy to the conventional variable flip angle (VFA) approach, and also determines the effect of the new T-mapping method on the K parameter. VFA and MP2RAGE T values were compared to the gold standard inverse recovery (IR) method in phantom over manually drawn ROIs. In vivo, ROIs were manually drawn over prostate and prostatic lesions. Average T values over ROIs were compared and K maps for each method were calculated via the extended Tofts model. VFA-T maps overestimated T values by up to 50% compared to gold standard IR T values in phantom. MP2RAGE differed by up to 9%. MP2RAGE-T and K values were significantly different from VFA values over prostatic lesions (p < 0.05). K was consistently underestimated using VFA compared to MP2RAGE (p < 0.05). MP2RAGE T maps are shown to be more accurate, leading to more reliable pharmacokinetic modeling. This can potentially lead to better lesion characterization and improve clinical outcomes.
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http://dx.doi.org/10.1016/j.mri.2020.01.001 | DOI Listing |
Magn Reson Imaging
January 2025
Department of Radiology, University Hospital of Strasbourg, 1 Avenue Moliere, 67098 Strasbourg, France.
Purpose: Compressed Sensing (CS) is an emerging technique to accelerate MRI acquisitions. The aim of this study was to assess the reliability and accuracy of cartilage thickness measurements in the knee using a CS-enabled isotropic 3D Fast Spin-Echo (FSE) sequence on a 3-T MRI scanner.
Methods: Twenty-eight tibial condyle sections were collected from 14 adult patients who underwent total knee arthroplasty.
Radiat Oncol
December 2024
Department of Cognitive Neuropsychology, Tilburg University, Tilburg, The Netherlands.
Background And Purpose: Timely identification of local failure after stereotactic radiotherapy for brain metastases allows for treatment modifications, potentially improving outcomes. While previous studies showed that adding radiomics or Deep Learning (DL) features to clinical features increased Local Control (LC) prediction accuracy, their combined potential to predict LC remains unexplored. We examined whether a model using a combination of radiomics, DL and clinical features achieves better accuracy than models using only a subset of these features.
View Article and Find Full Text PDFMagn Reson Med
December 2024
Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, New York, USA.
Purpose: To implement and evaluate the feasibility of brain spin-lattice relaxation in the rotating frame (T1ρ) mapping using a novel optimized pulse sequence that incorporates weighted spin-lock acquisitions, enabling high-resolution three-dimensional (3D) mapping.
Methods: The optimized variable flip-angle framework, previously proposed for knee T1ρ mapping, was enhanced by integrating weighted spin-lock acquisitions. This strategic combination significantly boosts signal-to-noise ratio (SNR) while reducing data acquisition time, facilitating high-resolution 3D-T1ρ mapping of the brain.
Background: When antispasmodics are unavailable, the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER; called BLADE by Siemens Healthineers) or half Fourier single-shot turbo spin echo (HASTE) is clinically used in gynecologic MRI. However, their imaging qualities are limited compared to Turbo Spin Echo (TSE) with antispasmodics. Even with antispasmodics, TSE can be artifact-affected, necessitating a rapid backup sequence.
View Article and Find Full Text PDFFront Oncol
November 2024
Advanced Imaging Research Center, Oregon Health and Science University, Portland, OR, United States.
Quantitative dynamic contrast-enhanced (DCE) MRI as a promising method for the prediction of breast cancer response to neoadjuvant chemotherapy (NAC) has been demonstrated mostly in single-center and single-vendor platform studies. This preliminary study reports the initial experience in implementing quantitative breast DCE-MRI in multi-center (MC) and multi-vendor platform (MP) settings to predict NAC response. MRI data, including B mapping, variable flip angle (VFA) measurements of native tissue R (R), and DCE-MRI, were acquired during NAC at three sites using 3T systems with Siemens, Philips, and GE platforms, respectively.
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