Publications by authors named "R Neji"

Purpose: To demonstrate the feasibility of hepatic 3D MR elastography (MRE) at 0.55 T in healthy volunteers using Hadamard encoding and to study the effects of concomitant fields in the domain of MRE in general.

Methods: Concomitant field effects in MRE are assessed using a Taylor series expansion and an encoding scheme is proposed to study the corresponding effects on 3D MRE at 0.

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Purpose: To develop a 3D distortion-free reduced-FOV diffusion-prepared gradient-echo sequence and demonstrate its application in vivo for diffusion imaging of the spinal cord in healthy volunteers.

Methods: A 3D multi-shot reduced-FOV diffusion-prepared gradient-echo acquisition is achieved using a slice-selective tip-down pulse in the phase-encoding direction in the diffusion preparation, combined with magnitude stabilizers, centric k-space encoding, and 2D phase navigators to correct for intershot phase errors. The accuracy of the ADC values obtained using the proposed approach was evaluated in a diffusion phantom and compared to the tabulated reference ADC values and to the ADC values obtained using a standard spin echo diffusion-weighted single-shot EPI sequence (DW-SS-EPI).

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Article Synopsis
  • The study aimed to create and assess a new method for conducting free-breathing 3D whole-heart Cardiac Magnetic Resonance Angiography (CMRA) without contrast agents at a lower magnetic field strength of 0.55T.
  • To achieve this, researchers optimized pulse sequences and imaging techniques, incorporating advanced methods like low-rank denoising and respiratory motion correction, and tested their approach on 11 healthy volunteers.
  • Results showed that the new method produced high-quality images with minimal artifacts in just 6 minutes, matching the performance of higher field strength systems, paving the way for future testing in patients with heart conditions.
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Article Synopsis
  • Pretraining deep convolutional networks using natural images can enhance medical imaging analysis, particularly given the scarcity of annotated medical data.
  • The study compared 18 different pretrained backbone networks for evaluating the quality of PET brain scans, using data from multiple patients and testing against clinical quality metrics.
  • Results indicated that using residual units in backbone architectures improved performance, with many networks achieving a mean-absolute-error below 0.5, highlighting the potential of over-parameterization for automated image quality assessments.
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Background: Coronary computed tomography angiography (CCTA) is recommended as the first-line diagnostic imaging modality in low-to-intermediate-risk individuals suspected of stable coronary artery disease (CAD). However, CCTA exposes patients to ionizing radiation and potentially nephrotoxic contrast agents. Invasive coronary angiography is the gold-standard investigation to guide coronary revascularisation strategy; however, invasive procedures incur an inherent risk to the patient.

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