Unsupervised clustering analysis-based characterization of spatial profiles of inaccuracy in apparent diffusion coefficient values with varying acquisition plan orientation and diffusion weighting gradient direction - a large multicenter phantom study.

This large multicenter study of 37 magnetic resonance imaging scanners aimed at characterizing, for the first time, spatial profiles of inaccuracy (namely, Δ-profiles) in apparent diffusion coefficient (ADC) values with varying acquisition plan orientation and diffusion weighting gradient direction, using a statistical approach exploiting unsupervised clustering analysis. A diffusion-weighted imaging (DWI) protocol (b-value: 0-200-400-600-800-1000 s mm) with different combinations of acquisition plan orientation (axial/sagittal/coronal) and diffusion weighting gradient direction (anterior-posterior/left-right/feet-head) was acquired on a standard water phantom. For each acquisition setup, Δ-profiles along the 3 main orthogonal directions were characterized by fitting data with a second order polynomial function ().

DCE-MRI Radiomic analysis in triple negative ductal invasive breast cancer. Comparison between BRCA and not BRCA mutated patients: Preliminary results.

Objective: The research aimed to determine whether and which radiomic features from breast dynamic contrast enhanced (DCE) MRI could predict the presence of BRCA1 mutation in patients with triple-negative breast cancer (TNBC).

Material And Methods: This retrospective study included consecutive patients histologically diagnosed with TNBC who underwent breast DCE-MRI in 2010-2021. Baseline DCE-MRIs were retrospectively reviewed; percentage maps of wash-in and wash-out were computed and breast lesions were manually segmented, drawing a 5 mm-Region of Interest (ROI) inside the tumor and another 5 mm-ROI inside the contralateral healthy gland.

The impact of transfer learning on 3D deep learning convolutional neural network segmentation of the hippocampus in mild cognitive impairment and Alzheimer disease subjects.

Research on segmentation of the hippocampus in magnetic resonance images through deep learning convolutional neural networks (CNNs) shows promising results, suggesting that these methods can identify small structural abnormalities of the hippocampus, which are among the earliest and most frequent brain changes associated with Alzheimer disease (AD). However, CNNs typically achieve the highest accuracy on datasets acquired from the same domain as the training dataset. Transfer learning allows domain adaptation through further training on a limited dataset.

Uncover the Offensive Side of Disparagement Humor: An fMRI Study.

Disparagement humor is a kind of humor that denigrates, belittles an individual or a social group. In the aim to unveil the offensive side of these kinds of jokes, we have run an event-related fMRI study asking 30 healthy volunteers to judge the level of fun of a series of verbal stimuli that ended with a sentence that was socially inappropriate but funny (disparagement joke -DJ), socially inappropriate but not funny (SI) or neutral (N). Behavioral results showed disparagement jokes are perceived as funny and at the same time offensive.

On the dependence of quantitative diffusion-weighted imaging on scanner system characteristics and acquisition parameters: A large multicenter and multiparametric phantom study with unsupervised clustering analysis.

Purpose: The purpose of this multicenter phantom study was to exploit an innovative approach, based on an extensive acquisition protocol and unsupervised clustering analysis, in order to assess any potential bias in apparent diffusion coefficient (ADC) estimation due to different scanner characteristics. Moreover, we aimed at assessing, for the first time, any effect of acquisition plan/phase encoding direction on ADC estimation.

Methods: Water phantom acquisitions were carried out on 39 scanners.

Dependence of apparent diffusion coefficient measurement on diffusion gradient direction and spatial position - A quality assurance intercomparison study of forty-four scanners for quantitative diffusion-weighted imaging.

Purpose: To propose an MRI quality assurance procedure that can be used for routine controls and multi-centre comparison of different MR-scanners for quantitative diffusion-weighted imaging (DWI).

Materials And Methods: 44 MR-scanners with different field strengths (1 T, 1.5 T and 3 T) were included in the study.

A straightforward multiparametric quality control protocol for proton magnetic resonance spectroscopy: Validation and comparison of various 1.5 T and 3 T clinical scanner systems.

Purpose: The aim of this study was to propose and validate across various clinical scanner systems a straightforward multiparametric quality assurance procedure for proton magnetic resonance spectroscopy (MRS).

Methods: Eighteen clinical 1.5 T and 3 T scanner systems for MRS, from 16 centres and 3 different manufacturers, were enrolled in the study.

Brain Activation Patterns Characterizing Different Phases of Motor Action: Execution, Choice and Ideation.

Motor behaviour is controlled by a large set of interacting neural structures, subserving the different components involved in hierarchical motor processes. Few studies have investigated the neural substrate of higher-order motor ideation, i.e.

Quality assurance multicenter comparison of different MR scanners for quantitative diffusion-weighted imaging.

Purpose: To propose a magnetic resonance imaging (MRI) quality assurance procedure that can be used for multicenter comparison of different MR scanners for quantitative diffusion-weighted imaging (DWI).

Materials And Methods: Twenty-six centers (35 MR scanners with field strengths: 1T, 1.5T, and 3T) were enrolled in the study.

Transvaginal ultrasound assessment of uterine scar after previous caesarean section: comparison with 3T-magnetic resonance diffusion tensor imaging.

Purpose: This study aimed to evaluate 3-T magnetic resonance imaging in the analysis of caesarean scars in women with prior caesarean section (pCS) and investigate the potential added value of diffusion tensor imaging (3T-MR-DTI) with fibre tracking reconstruction, compared with transvaginal ultrasound (TVUS).

Methods: Thirty women who had previously undergone elective CS in a singleton pregnancy at term were examined (19 women with one pCS formed group 1 and 11 women with two pCS formed group 2). Patients underwent TVUS and 3T-MR-DTI within 2 days.

An algorithm to estimate anatomical connectivity between brain regions using diffusion MRI.

The study of anatomical connectivity is essential for interpreting functional MRI data and for establishing how brain areas are linked together into networks to support higher-order functions. Diffusion-weighted MR images (DWI) and tractography provide a unique noninvasive tool to explore the connectional architecture of the brain. The identification of anatomical circuits associated with a specific function can be better accomplished by the joint application of diffusion and functional MRI.

Magnetic resonance for quantitative assessment of liver steatosis: a new potential tool to monitor antiretroviral-drug-related toxicities.

Background: There is an increasing need for new diagnostic tools to monitor antiretroviral drug-related toxicities. Magnetic resonance (MR) imaging and MR spectroscopy are non-invasive diagnostic methods used in the detection and quantification of liver fat. The aim of this study was to compare sensitivity and specificity of different MR techniques in the quantitative assessment of liver steatosis, using liver biopsy as the reference standard, in patients with and without HIV infection.

Human parietofrontal networks related to action observation detected at rest.

Recent data show a broad correspondence between human resting-state and task-related brain networks. We performed a functional magnetic resonance imaging (fMRI) study to compare, in the same subjects, the spatial independent component analysis (ICA) maps obtained at rest and during the observation of either reaching/grasping hand actions or matching static pictures. Two parietofrontal networks were identified by ICA from action observation task data.

Combining neuropsychological and structural neuroimaging indicators of conversion to Alzheimer's disease in amnestic mild cognitive impairment.

Morphometric and neuropsychological retrospective studies of amnestic mild cognitive impairment (MCI) have demonstrated that regional atrophies and cognitive impairments may differentiate stable from progressing MCI. No measure has proved helpful prospectively. In this study, twenty five amnestic MCI patients and 25 healthy controls underwent structural MRI and comprehensive neuropsychological assessment.

Suggested visual hallucination without hypnosis enhances activity in visual areas of the brain.

This functional Magnetic Resonance Imaging (fMRI) study investigated high and low suggestible people responding to two visual hallucination suggestions with and without a hypnotic induction. Participants in the study were asked to see color while looking at a grey image, and to see shades of grey while looking at a color image. High suggestible participants reported successful alterations in color perception in both tasks, both in and out of hypnosis, and showed a small benefit if hypnosis was induced.

Reduction of scatter radiation during transradial percutaneous coronary angiography: a randomized trial using a lead-free radiation shield.

Background: Occupational radiation exposure is a growing problem due to the increasing number and complexity of interventional procedures performed. Radial artery access has reduced the number of complications at the price of longer procedure duration. Radpad® scatter protection is a sterile, disposable bismuth-barium radiation shield drape that should be able to decrease the dose of operator radiation during diagnostic and interventional procedures.

Humor comprehension and appreciation: an FMRI study.

Humor is a unique ability in human beings. Suls [A two-stage model for the appreciation of jokes and cartoons. In P.

Ex vivo HR-MAS MRS of human meningiomas: a comparison with in vivo 1H MR spectra.

We report on the magnetic resonance spectroscopy (MRS) characterisation of different human meningiomas. Three histological subtypes of meningiomas (meningothelial, fibrous and oncocytic) were analysed both through in vivo and ex vivo MRS experiments. The ex vivo high-resolution magic angle spinning (HR-MAS) investigations, permitting an accurate description of the metabolic profile, are very helpful for the assignment of the resonances in vivo of human meningiomas and for the validation of the quantification procedure of in vivo MR spectra.