For every patient, the MR safety evaluation should include the assessment of risks in three key areas, each corresponding to a specific hazard posed by the electromagnetic fields generated by the MR scanner: ferromagnetic attraction and displacement by the static field; stimulation, acoustic noise, and device interaction by the gradient fields; and bulk and focal heating by the radiofrequency field. MR safety guidelines and procedures are typically designed around the "average" patient: adult, responsive, and of typical habitus. For this type of patient, we can safely expect that a detailed history can identify metallic objects inside and outside the body, verbal contact during the scan can detect signs of discomfort from heating or acoustic noise, and safety calculations performed by the scanner can prevent hyperthermia.
View Article and Find Full Text PDFRadiol Cardiothorac Imaging
August 2024
Introduction/aims: Muscle diffusion tensor imaging has not yet been explored in facioscapulohumeral muscular dystrophy (FSHD). We assessed diffusivity parameters in FSHD subjects compared with healthy controls (HCs), with regard to their ability to precede any fat replacement or edema.
Methods: Fat fraction (FF), water T2 (wT2), mean, radial, axial diffusivity (MD, RD, AD), and fractional anisotropy (FA) of thigh muscles were calculated in 10 FSHD subjects and 15 HCs.
G Ital Cardiol (Rome)
April 2024
Across the Tree of Life, most studies of phenotypic disparity and diversification have been restricted to adult organisms. However, many lineages have distinct ontogenetic phases that differ from their adult forms in morphology and ecology. Focusing disproportionately on the evolution of adult forms unnecessarily hinders our understanding of the pressures shaping evolution over time.
View Article and Find Full Text PDFBackground: While surgery is almost always indicated for acute type A aortic dissections (ATAADs), the extent of surgery is often debated, with some surgeons preferring a conservative option and others preferring a more radical option This study aims to assess the outcome after surgery for ATAAD and the prognostic impact of surgical strategy (with without aortic arch replacement).
Methods: Data was gathered between 1 January 2005 and 31 December 2021 and retrospectively analyzed with multivariable logistic and Cox regression to ascertain risk factors and survival respectively.
Results: A total of 601 patients underwent type A aortic dissection repair across the recruiting centers with an operative mortality of 24.
J Clin Med
December 2023
Objective: To describe a study protocol for investigating the functional association between posture, spinal balance, ambulatory biomechanics, paraspinal muscle fatigue, paraspinal muscle quality and symptoms in patients with symptomatic lumbar spinal stenosis (sLSS) before and 1-year after elective surgical intervention.
Design: Single-centre prospective, experimental, multimodal (clinical, biomechanical, radiological) study with three instances of data collection: baseline (study visit 1), 6-month follow-up (remote) and 1-year follow-up (study visit 2). Both study visits include an in vivo experiment aiming to elicit paraspinal muscle fatigue for postural assessment in a non-fatigued and fatigued state.
Objectives: To validate the correlation between histopathological findings and quantitative magnetic resonance imaging (qMRI) fat fraction (FF) and water T2 mapping in patients with idiopathic inflammatory myopathy (IIM).
Methods: The study included 13 patients with histopathologically confirmed IIM who underwent dedicated thigh qMRI scanning within 1 month before open muscle biopsy. For the biopsied muscles, FF derived from the iterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation (IDEAL-IQ) and T2 time from T2 mapping with chemical shift selective fat saturation were measured using a machine learning software.
Type A acute aortic dissection is associated with significant morbidity and mortality, with prompt referral imaging and management to tertiary referral centers needed urgently. Surgery is usually needed emergently, but the choice of surgery often varies depending on the patient and the presentation. Staff and center expertise also play a major role in determining the surgical strategy employed.
View Article and Find Full Text PDFLung function testing and lung imaging are commonly used techniques to monitor respiratory diseases, such as cystic fibrosis (CF). The nitrogen (N) multiple-breath washout technique (MBW) has been shown to detect ventilation inhomogeneity in CF, but the underlying pathophysiological processes that are altered are often unclear. Dynamic oxygen-enhanced magnetic resonance imaging (OE-MRI) could potentially be performed simultaneously with MBW because both techniques require breathing of 100% oxygen (O) and may allow for visualisation of alterations underlying impaired MBW outcomes.
View Article and Find Full Text PDFPurpose: To provide a robust whole-brain quantitative magnetization transfer (MT) imaging method that is not limited by long acquisition times.
Methods: Two variants of a spiral 2D interleaved multi-slice spoiled gradient echo (SPGR) sequence are used for rapid quantitative MT imaging of the brain at 3 T. A dual flip angle, steady-state prepared, double-contrast method is used for combined B and-T mapping in combination with a single-contrast MT-prepared acquisition over a range of different saturation flip angles (50 deg to 850 deg) and offset frequencies (1 kHz and 10 kHz).
Purpose: Quantitative Muscle MRI (qMRI) is a valuable and non-invasive tool to assess disease involvement and progression in neuromuscular disorders being able to detect even subtle changes in muscle pathology. The aim of this study is to evaluate the feasibility of using a conventional short-tau inversion recovery (STIR) sequence to predict fat fraction (FF) and water T2 (wT2) in skeletal muscle introducing a radiomic workflow with standardized feature extraction combined with machine learning algorithms.
Methods: Twenty-five patients with facioscapulohumeral muscular dystrophy (FSHD) were scanned at calf level using conventional STIR sequence and qMRI techniques.