Quantifying spatial and dynamic lung abnormalities with 3D PREFUL FLORET UTE imaging: A feasibility study.

Purpose: Pulmonary MRI faces challenges due to low proton density, rapid transverse magnetization decay, and cardiac and respiratory motion. The fermat-looped orthogonally encoded trajectories (FLORET) sequence addresses these issues with high sampling efficiency, strong signal, and motion robustness, but has not yet been applied to phase-resolved functional lung (PREFUL) MRI-a contrast-free method for assessing pulmonary ventilation during free breathing. This study aims to develop a reconstruction pipeline for FLORET UTE, enhancing spatial resolution for three-dimensional (3D) PREFUL ventilation analysis.

Xe Image Processing Pipeline: An open-source, graphical user interface application for the analysis of hyperpolarized Xe MRI.

Purpose: Hyperpolarized Xe MRI presents opportunities to assess regional pulmonary microstructure and function. Ongoing advancements in hardware, sequences, and image processing have helped it become increasingly adopted for both research and clinical use. As the number of applications and users increase, standardization becomes crucial.

Quantifying abnormal alveolar microstructure in cystic fibrosis lung disease via hyperpolarized Xe diffusion MRI.

Rationale: Cystic Fibrosis (CF) progresses through recurrent infection and inflammation, causing permanent lung function loss and airway remodeling. CT scans reveal abnormally low-density lung parenchyma in CF, but its microstructural nature remains insufficiently explored due to clinical CT limitations. To this end, diffusion-weighted Xe MRI is a non-invasive and validated measure of lung microstructure.

A decay-modeled compressed sensing reconstruction approach for non-Cartesian hyperpolarized Xe MRI.

Purpose: Hyperpolarized Xe MRI benefits from non-Cartesian acquisitions that sample k-space efficiently and rapidly. However, their reconstructions are complex and burdened by decay processes unique to hyperpolarized gas. Currently used gridded reconstructions are prone to artifacts caused by magnetization decay and are ill-suited for undersampling.

B and magnetization decay correction for hyperpolarized Xe lung imaging using sequential 2D spiral acquisitions.

Purpose: To mitigate signal variations caused by inhomogeneous RF and magnetization decay in hyperpolarized Xe ventilation images using flip-angle maps generated from sequential 2D spiral ventilation images acquired in a breath-hold. Images and correction maps were compared with those obtained using conventional, 2D gradient-recalled echo.

Theory And Methods: Analytical expressions to predict signal intensity and uncertainty in flip-angle measurements were derived from the Bloch equations and validated by simulations and phantom experiments.

Short-term structural and functional changes after airway clearance therapy in cystic fibrosis.

Background: Airway clearance therapy (ACT) with a high-frequency chest wall oscillation (HFCWO) vest is a common but time-consuming treatment. Its benefit to quality of life for cystic fibrosis (CF) patients is well established but has been questioned recently as new highly-effective modulator therapies begin to change the treatment landscape. Xe ventilation MRI has been shown to be very sensitive to lung obstruction in mild CF disease, making it an ideal tool to identify and quantify subtle, regional changes.

Diffusion weighted hyperpolarized Xe MRI of the lung with 2D and 3D (FLORET) spiral.

Purpose: To enable efficient hyperpolarized Xe diffusion imaging using 2D and 3D (Fermat Looped, ORthogonally Encoded Trajectories, FLORET) spiral sequences and demonstrate that Xe ADCs obtained using these sequences are comparable to those obtained using a conventional, 2D gradient-recalled echo (GRE) sequence.

Theory And Methods: Diffusion-weighted Xe MRI (b-values = 0, 7.5, 15 s/cm ) was performed in four healthy volunteers and one subject with lymphangioleiomyomatosis using slice-selective 2D-GRE (scan time = 15 s), slice-selective 2D-Spiral (4 s), and 3D-FLORET (16 s) sequences.

Atypical Case of Schmidt's Syndrome in a Young Male.

Autoimmune polyendocrine syndrome type 2, also known as Schmidt's syndrome, is a rare autosomal dominant life-threatening syndrome. It is defined by the presence of Addison's disease in combination with at least one of the known autoimmune diseases: thyroid autoimmune disease, type 1 diabetes, and hypogonadism. It is more common in middle-aged females and is treatable if diagnosed early.

Improving hyperpolarized Xe ADC mapping in pediatric and adult lungs with uncertainty propagation.

Rationale: Hyperpolarized (HP) Xe-MRI provides non-invasive methods to quantify lung function and structure, with the Xe apparent diffusion coefficient (ADC) being a well validated measure of alveolar airspace size. However, the experimental factors that impact the precision and accuracy of HP Xe ADC measurements have not been rigorously investigated. Here, we introduce an analytical model to predict the experimental uncertainty of Xe ADC estimates.

Categorizing cortical dysplasia lesions for surgical outcome using network functional connectivity.

Objective: Focal cortical dysplasia (FCD) is often associated with drug-resistant epilepsy, leading to a recommendation to surgically remove the seizure focus. Predicting outcome for resection of FCD is challenging, requiring a new approach. Lesion-symptom mapping is a powerful and broadly applicable method for linking neurological symptoms or outcomes to damage to particular brain regions.