Inversion-recovery ultrashort-echo-time (IR-UTE) MRI-based detection of radiation dose heterogeneity in gynecologic cancer patients treated with HDR brachytherapy.

Purpose: To evaluate the relationship between delivered radiation (RT) and post-RT inversion-recovery ultrashort-echo-time (IR-UTE) MRI signal-intensity (SI) in gynecologic cancer patients treated with high-dose-rate (HDR) brachytherapy (BT).

Methods: Seven patients underwent whole-pelvis RT (WPRT) followed by BT to the high-risk clinical target volume (HR-CTV). MR images were acquired at three time-points; pre-RT, post-WPRT/pre-BT, and 3-6 months post-BT.

MRI-Conditional Eccentric-Tube Injection Needle: Design, Fabrication, and Animal Trial.

Effective radiation therapy aims to maximize the radiation dose delivered to the tumor while minimizing damage to the surrounding healthy tissues, which can be a challenging task when the tissue-tumor space is small. To eliminate the damage to healthy tissue, it is now possible to inject biocompatible hydrogels between cancerous targets and surrounding tissues to create a spacer pocket. Conventional methods have limitations in poor target visualization and device tracking.

Predictive potential of MRI in differentiating the predominant component in biphasic pleural mesothelioma.

Purpose: To assess the potential of apparent diffusion coefficient (ADC) values derived from diffusion weighted (DW) MRI preoperatively to predict the predominant histologic component among biphasic pleural mesothelioma (PM) tumors.

Methods: ADC maps were generated from DW MRI scans. Histology and predominant component of biphasic PM were confirmed following surgical resection.

GABA, glutamate and excitatory-inhibitory ratios measured using short-TE STEAM MRS at 7-Tesla: Effects of macromolecule basis sets and baseline parameters.

Rationale And Objectives: Macromolecules (MMs) affect the precision and accuracy of neurochemical quantification in magnetic resonance spectroscopy. A measured MM basis is increasingly used in LCModel analysis combined with a spline baseline, whose stiffness is controlled by a parameter named DKNTMN. The effects of measured MM basis and DKNTMN were investigated.

Quantification of Cerebral Glucose Concentrations via Detection of the H1-α-Glucose Peak in H MRS at 7 T.

Background: Sensitive detection and quantification of cerebral glucose is desired.

Purpose: To quantify cerebral glucose by detecting the H1-α-glucose peak at 5.23 ppm in H magnetic resonance spectroscopy at 7 T.

Inter- and intravisit repeatability of free-breathing MRI in pediatric cystic fibrosis lung disease.

Purpose: The purpose of this study is to assess the intra- and interscan repeatability of free-breathing phase-resolved functional lung (PREFUL) MRI in stable pediatric cystic fibrosis (CF) lung disease in comparison to static breath-hold hyperpolarized 129-xenon MRI (Xe-MRI) and pulmonary function tests.

Methods: Free-breathing 1-hydrogen MRI and Xe-MRI were acquired from 15 stable pediatric CF patients and seven healthy age-matched participants on two visits, 1 month apart. Same-visit MRI scans were also performed on a subgroup of the CF patients.

Simultaneous multislice diffusion-weighted imaging versus standard diffusion-weighted imaging in whole-body PET/MRI.

Objective: To compare standard (STD-DWI) single-shot echo-planar imaging DWI and simultaneous multislice (SMS) DWI during whole-body positron emission tomography (PET)/MRI regarding acquisition time, image quality, and lesion detection.

Methods: Eighty-three adults (47 females, 57%), median age of 64 years (IQR 52-71), were prospectively enrolled from August 2018 to March 2020. Inclusion criteria were (a) abdominal or pelvic tumors and (b) PET/MRI referral from a clinician.

Multicenter Repeatability and Reproducibility of MR Fingerprinting in Phantoms and in Prostatic Tissue.

Purpose: To evaluate multicenter repeatability and reproducibility of T and T maps generated using MR fingerprinting (MRF) in the International Society for Magnetic Resonance in Medicine/National Institute of Standards and Technology MRI system phantom and in prostatic tissues.

Methods: MRF experiments were performed on 5 different 3 Tesla MRI scanners at 3 different institutions: University Hospitals Cleveland Medical Center (Cleveland, OH), Brigham and Women's Hospital (Boston, MA) in the United States, and Diagnosticos da America (Rio de Janeiro, RJ) in Brazil. Raw MRF data were reconstructed using a Gadgetron-based MRF online reconstruction pipeline to yield quantitative T and T maps.

Clinical Feasibility of Structural and Functional MRI in Free-Breathing Neonates and Infants.

Background: Evaluation of structural lung abnormalities with magnetic resonance imaging (MRI) has previously been shown to be predictive of clinical neonatal outcomes in preterm birth. MRI during free-breathing with phase-resolved functional lung (PREFUL) may allow for complimentary functional information without exogenous contrast.

Purpose: To investigate the feasibility of structural and functional pulmonary MRI in a cohort of neonates and infants with no cardiorespiratory disease.

MR-Tracked Deflectable Stylet for Gynecologic Brachytherapy.

Brachytherapy is a radiation based treatment that is implemented by precisely placing focused radiation sources into tumors. In advanced interstitial cervical cancer bracytherapy treatment, this is performed by placing a metallic rod ("stylet") inside a hollow cylindrical tube ("catheter") and advancing the pair to the desired target. The stylet is removed once the target is reached, followed by the insertion of radiation sources into the catheter.

Clinical 7T MRI for epilepsy care: Value, patient selection, technical issues, and outlook.

Ultra-high-field 7.0 Tesla (T) MRI offers substantial gains in signal-to-noise ratio (SNR) over 3T and 1.5T, but for over two decades has remained a research tool, while 3T scanners have achieved widespread clinical use.

Dynamic contrast-enhanced magnetic resonance imaging of the lung reveals important pathobiology in idiopathic pulmonary fibrosis.

Introduction: Evidence suggests that abnormalities occur in the lung microvasculature in idiopathic pulmonary fibrosis (IPF). We hypothesised that dynamic contrast-enhanced (DCE)-magnetic resonance imaging (MRI) could detect alterations in permeability, perfusion and extracellular extravascular volume in IPF, thus providing regional functional information not otherwise available.

Methods: Healthy controls and IPF subjects underwent DCE-MRI of the thorax using a dynamic volumetric radial sampling sequence and administration of gadoterate meglumine at a dose of 0.

Interobserver Variability of Quantitative and Qualitative Assessment Using MRI in Malignant Pleural Mesothelioma.

Purpose: To evaluate the interobserver variability associated with quantitative and qualitative MRI assessments of malignant pleural mesothelioma (MPM).

Materials And Methods: Patients with MPM who underwent uniform-protocol preoperative MRI between 2009 and 2014 were included. The MRI-derived tumor volume was estimated.

Ferumoxytol-enhanced ultrashort TE MRA and quantitative morphometry of the human kidney vasculature.

Purpose: To evaluate the feasibility of Quantitative Ultrashort-Time-to-Echo Contrast-Enhanced (QUTE-CE) MRA using ferumoxytol as a contrast agent for abdominal angiography in the kidney.

Methods: Four subjects underwent ferumoxytol-enhanced MRA with the 3D UTE Spiral VIBE WIP sequence at 3 T. Image quality metrics were quantified, specifically the blood Signal-to-Noise Ratio (SNR), blood-tissue Contrast-to-Noise Ratio (CNR) and Intraluminal Signal Heterogeneity (ISH) from both the aorta and inferior vena cava (IVC).

Repeatability of proton magnetic resonance spectroscopy of the brain at 7 T: effect of scan time on semi-localized by adiabatic selective refocusing and short-echo time stimulated echo acquisition mode scans and their comparison.

Background: Proton magnetic resonance spectroscopy (MRS) provides a unique opportunity for measurements of the brain's metabolic profile. Two methods of mainstream data acquisition are compared at 7 T, which provides certain advantages as well as challenges. The two representative methods have seldom been compared in terms of measured metabolite concentrations and different scan times.

Comparison of Functional Free-Breathing Pulmonary H and Hyperpolarized Xe Magnetic Resonance Imaging in Pediatric Cystic Fibrosis.

Rationale And Objectives: Phase resolved functional lung (PREFUL) magnetic resonance imaging (MRI) is a free-breathing H-based technique that produces maps of fractional ventilation (FV). This study compared ventilation defect percent (VDP) calculated using PREFUL to hyperpolarized (HP) Xe MRI and pulmonary function tests in pediatric cystic fibrosis (CF).

Materials And Methods: 27 pediatric participants were recruited (mean age 13.

Clinical Implementation of a Free-Breathing, Motion-Robust Dynamic Contrast-Enhanced MRI Protocol to Evaluate Pleural Tumors.

The purpose of this study was to develop a motion insensitive clinical dynamic contrast-enhanced MRI (DCE-MRI) protocol to assess the response of pleural tumors in clinical trials. Thirty-two patients with pleura-based lesions were administered contrast material and imaged with gradient-recalled echo DCE-MRI sequence variants: either a traditional cartesian k-space acquisition (FLASH), a time-resolved imaging with stochastic trajectories acquisition (TWIST), or a radial stack-of-stars acquisition (radial) sequence in addition to other standard-of-care imaging sequences. Each image acquisition's sensitivity to motion was evaluated by comparing the motion of the thoracic border in 3D throughout the acquisition.

Free-breathing dynamic contrast-enhanced magnetic resonance of interstitial lung fibrosis.

Purpose: Computed tomography (CT) imaging is the standard to assess interstitial lung disease. Magnetic resonance (MR) is potentially advantageous due to superior tissue characterization and better assessment of blood flow dynamics. This study aimed to evaluate idiopathic pulmonary fibrosis (IPF) using prototype 4D Stack of Stars GRE (StarVIBE) MR and compare it to CT.

Image quality and diagnostic accuracy of complex-averaged high b value images in diffusion-weighted MRI of prostate cancer.

Purpose: To evaluate the impact of complex-averaging on image quality (IQ) and diagnostic accuracy of acquired and calculated high b value (aHBV, cHBV) images in diffusion-weighted prostate MRI.

Materials And Methods: This retrospective study included 84 patients who underwent multiparametric prostate MRI at 3 Tesla without endorectal coil. DWIs were acquired at three different b values which included two lower b values (b = 50,900 s/mm) and one higher b value (aHBV at 2000 s/mm).

Gadofosveset-enhanced lung magnetic resonance imaging to detect ongoing vascular leak in pulmonary fibrosis.

Vascular leak is increased diffusely in the lungs in pulmonary fibrosis and is not limited to radiographic areas of disease involvement.

Prospective Clinical Implementation of a Novel Magnetic Resonance Tracking Device for Real-Time Brachytherapy Catheter Positioning.

Purpose: We designed and built dedicated active magnetic resonance (MR)-tracked (MRTR) stylets. We explored the role of MRTR in a prospective clinical trial.

Methods And Materials: Eleven gynecologic cancer patients underwent MRTR to rapidly optimize interstitial catheter placement.

Ultra high-field (7tesla) magnetic resonance spectroscopy in Amyotrophic Lateral Sclerosis.

The main objective of this study was to utilize high field (7T) in vivo proton magnetic resonance imaging to increase the ability to detect metabolite changes in people with ALS, specifically, to quantify levels of glutamine and glutamine separately. The second objective of this study was to correlate metabolic markers with clinical outcomes of disease progression. 13 ALS participants and 12 age-matched healthy controls (HC) underwent 7 Tesla MRI and MRS.