Ventilation defect burden predicts lung cancer resection outcomes.

Background: Abnormal ventilation prior to lung cancer resection has not been investigated using modern ventilation imaging modalities and may better predict postoperative outcomes than guideline-recommended lung function tests. Our objective was to quantify the burden of ventilation defects observed using Technegas single-photon emission computed tomography (SPECT) and Xe magnetic resonance imaging (MRI) before lung cancer resection, and to evaluate their association with postoperative pulmonary complications and length of hospital stay.

Methods: This was a prospective, 6-week, observational study of adults undergoing lung cancer resection at a single centre.

Exercise-Induced Changes in Knee Cartilage In Vivo: Comparing MRI Sequences.

The purpose was to assess the agreement in measures of acute knee cartilage thickness and composition change after loading in clinical knee osteoarthritis (OA) between two magnetic resonance imaging (MRI) acquisition approaches: (1) single sequence approach using quantitative double-echo in steady-state (qDESS), which allows simultaneous morphological and compositional scanning, versus (2) multi-sequence approach that captures morphology (fast spoiled gradient recalled (FSPGR) or qDESS) and composition (multi-echo spin echo (MESE)) separately. Twenty adults with clinical knee OA participated. 3T MR scans were acquired before and immediately after a 25-min treadmill walk at a standardized speed.

A Review on Accelerated Magnetic Resonance Imaging Techniques: Parallel Imaging, Compressed Sensing, and Machine Learning.

A concise overview of three major advancements in fast magnetic resonance imagine (MRI) reconstruction techniques is presented, focusing on their roles in enhancing image quality and reducing acquisition times. The first set of methods, parallel imaging techniques, includes sensitivity encoding (SENSE) and generalized autocalibrating partially parallel acquisitions (GRAPPA). SENSE utilizes spatial sensitivity information from multiple receiver coils to accelerate image acquisition by undersampling k-space data and reconstructing images using coil sensitivity profiles, allowing for faster scans.

Assessment of reconstruction accuracy for under-sampled 31P-MRS data using compressed sensing and a low rank Hankel matrix completion approach.

Phosphorus magnetic resonance spectroscopy and spectroscopic imaging (P-MRS/MRSI) are techniques to evaluate energy metabolism , they are capable of measuring metabolites such as phosphocreatine and inorganic phosphate in muscle and brain tissue. Despite their capability, these techniques are not very often used in clinical settings due to the long acquisition times required. In recent years, compressed sensing has been widely used as an acceleration method for MRI signal acquisition and translated to MRS.

Compressed Sensing-Accelerated Free-Breathing Liver MRI at 7 T.

Ultra-high field MRI facilitates imaging at high spatial resolutions, which may become important for detailed anatomical and pathological assessment of the human liver. Therefore, we aimed to advance structural liver imaging at 7 T by implementing a high-resolution, phase-shimmed, free-breathing liver scan. Six healthy participants underwent liver MRI scans at 7 T, utilizing an eight-channel parallel transmission system for phase shimming.

Assessing measurement consistency of a diffusion tensor imaging (DTI) quality control (QC) anisotropy phantom.

Objectives: We evaluated a quality control (QC) phantom designed to mimic diffusion characteristics and white matter fiber tracts in the brain. We hypothesized that acquisition of diffusion tensor imaging (DTI) data on different vendors and over multiple repeated measures would not contribute to significant variability in calculated diffusion tensor scalar metrics such as fractional anisotropy (FA) and mean diffusivity (MD).

Materials And Methods: The DTI QC phantom was scanned using a 32-direction DTI sequence on General Electric (GE), Siemens, and Philips 3 Tesla scanners.

The Concussion, Exercise, and Brain Networks (ConExNet) study: a cohort study aimed at understanding the effects of sub-maximal aerobic exercise on resting state functional brain activity in pediatric concussion.

Background: Recent scientific evidence has challenged the traditional "rest-is-best" approach for concussion management. It is now thought that "exercise-is-medicine" for concussion, owing to dozens of studies which demonstrate that sub-maximal, graded aerobic exercise can reduce symptom burden and time to symptom resolution. However, the primary neuropathology of concussion is altered functional brain activity.

Denoising of the gradient artifact present in simultaneous studies of muscle blood oxygen level dependent (BOLD) signal and electromyography (EMG).

The MR-induced gradient artifact affects EMG recordings during simultaneous muscle BOLD/EMG acquisitions. However, no dedicated hardware can remove the gradient artifact easily, and alternative methods are expensive and time-consuming. This study aimed to develop three denoising methods requiring different processing levels and MR-compatible hardware.

Sampling pattern discrepancy in the application of compressed sensing hyperpolarized xenon-129 lung MRI.

Although hyperpolarized (HP) Xe ventilation MRI can be carried out within a breath hold, it is still challenging for many sick patients. Compressed sensing (CS) is a viable alternative to accelerate this approach. However, undersampled images with identical sampling ratios differ from one another.

The Role of Calcium in Non-Invasively Imaging Breast Cancer: An Overview of Current and Modern Imaging Techniques.

The landscape of breast cancer diagnostics has significantly evolved over the past decade. With these changes, it is possible to provide a comprehensive assessment of both benign and malignant breast calcifications. The biochemistry of breast cancer and calcifications are thoroughly examined to describe the potential to characterize better different calcium salts composed of calcium carbonate, calcium oxalate, or calcium hydroxyapatite and their associated prognostic implications.

A review of brain regions and associated post-concussion symptoms.

The human brain is an exceptionally complex organ that is comprised of billions of neurons. Therefore, when a traumatic event such as a concussion occurs, somatic, cognitive, behavioral, and sleep impairments are the common outcome. Each concussion is unique in the sense that the magnitude of biomechanical forces and the direction, rotation, and source of those forces are different for each concussive event.

New Insights Into Accelerometer-Measured Habitual Physical Activity and Sedentary Time During Early Recovery in Pediatric Concussion.

Purpose: Concussion management is shifting away from a rest-is-best approach, as data now suggest that exercise-is-medicine for this mild brain injury. Despite this, we have limited data on habitual physical activity following concussion. Therefore, our objective was to quantify accelerometer-measured physical activity and sedentary time in children with concussion (within the first month of injury) and healthy controls.

Comparison of ventilation defects quantified by Technegas SPECT and hyperpolarized Xe MRI.

The ideal contrast agents for ventilation SPECT and MRI are Technegas and Xe gas, respectively. Despite increasing interest in the clinical utility of ventilation imaging, these modalities have not been directly compared. Therefore, our objective was to compare the ventilation defect percent (VDP) assessed by Technegas SPECT and hyperpolarized Xe MRI in patients scheduled to undergo lung cancer resection with and without pre-existing obstructive lung disease.

Sex-specific differences in resting-state functional brain activity in pediatric concussion.

Pediatric concussion has a rising incidence and can lead to long-term symptoms in nearly 30% of children. Resting state functional magnetic resonance imaging (rs-fMRI) disturbances are a common pathological feature of pediatric concussion, though no studies have explicitly examined sex-differences with respect to this outcome, precluding a sex-specific understanding of the functional neuropathology of pediatric concussion. Therefore, we performed a secondary data analysis of rs-fMRI data collected on children with concussion (n = 29) recruited from in a pediatric hospital setting, with greater than 12:1 matched control data accessed from the open-source ABIDE-II database.

Amyloid-PET of the white matter: Relationship to free water, fiber integrity, and cognition in patients with dementia and small vessel disease.

White matter (WM) injury is frequently observed along with dementia. Positron emission tomography with amyloid-ligands (Aβ-PET) recently gained interest for detecting WM injury. Yet, little is understood about the origin of the altered Aβ-PET signal in WM regions.

Nailfold capillaroscopy and deep learning in diabetes.

Objective: To determine whether nailfold capillary images, acquired using video capillaroscopy, can provide diagnostic information about diabetes and its complications.

Research Design And Methods: Nailfold video capillaroscopy was performed in 120 adult patients with and without type 1 or type 2 diabetes, and with and without cardiovascular disease. Nailfold images were analyzed using convolutional neural networks, a deep learning technique.

Vascular burden and cognition: Mediating roles of neurodegeneration and amyloid PET.

It remains unclear to what extent cerebrovascular burden relates to amyloid beta (Aβ) deposition, neurodegeneration, and cognitive dysfunction in mixed disease populations with small vessel disease and Alzheimer's disease (AD) pathology. In 120 subjects, we investigated the association of vascular burden (white matter hyperintensity [WMH] volumes) with cognition. Using mediation analyses, we tested the indirect effects of WMH on cognition via Aβ deposition ( F-AV45 positron emission tomography [PET]) and neurodegeneration (cortical thickness or F fluorodeoxyglucose PET) in AD signature regions.

Exploring the relationship between resting-state intra-network connectivity and accelerometer-measured physical activity in pediatric concussion: a cohort study.

Our objective was to explore the association between resting-state functional connectivity and accelerometer-measured physical activity in pediatric concussion. Fourteen children with concussion (aged 14.54 ± 2.

Non-invasive MR imaging techniques for measuring femoral arterial flow in a pediatric and adolescent cohort.

Magnetic Resonance Imaging (MRI) is well-suited for imaging peripheral blood flow due to its non-invasive nature and excellent spatial resolution. Although MRI is routinely used in adults to assess physiological changes in chronic diseases, there are currently no MRI-based data quantifying arterial flow in pediatric or adolescent populations during exercise. Therefore the current research sought to document femoral arterial blood flow at rest and following exercise in a pediatric-adolescent population using phase contrast MRI, and to present test-retest reliability data for this method.

Impaired Cold-Stimulated Supraclavicular Brown Adipose Tissue Activity in Young Boys With Obesity.

Childhood obesity is a growing worldwide problem. In adults, lower cold-induced brown adipose tissue (BAT) activity is linked to obesity and metabolic dysfunction; this relationship remains uncertain in children. In this cross-sectional study, we compared cold-induced supraclavicular (SCV) BAT activity (percent change in proton density fat fraction [PDFF]) within the SCV region after 1 h of whole-body cold exposure (18°C), using MRI in 26 boys aged 8-10 years: 13 with normal BMI and 13 with overweight/obesity.

Investigating acute changes in osteoarthritic cartilage by integrating biomechanics and statistical shape models of bone: data from the osteoarthritis initiative.

Objective: This proof-of-principle study integrates joint reaction forces (JRFs) and bone shape to assess acute cartilage changes from walking and cycling.

Methods: Sixteen women with symptomatic knee osteoarthritis were recruited. Biomechanical assessment estimated JRFs during walking and cycling.

The Effect of Exercise on Neural Activation and Cognition: A Review of Task-Based fMRI Studies.

Numerous studies have stressed the importance of exercise in promoting physical and mental health and for aiding in cognition. Encouragingly, physical exercise has been shown to reduce the risk of developing Alzheimer's disease and to mitigate hemiparesis experienced by stroke patients. Additionally, today where over 1.

A Radiology-focused Review of Predictive Uncertainty for AI Interpretability in Computer-assisted Segmentation.

The recent advances and availability of computer hardware, software tools, and massive digital data archives have enabled the rapid development of artificial intelligence (AI) applications. Concerns over whether AI tools can "communicate" decisions to radiologists and primary care physicians is of particular importance because automated clinical decisions can substantially impact patient outcome. A challenge facing the clinical implementation of AI stems from the potential lack of trust clinicians have in these predictive models.

An approach to evaluation of the point-spread function for Na magnetic resonance imaging.

Despite the technical challenges that require lengthy acquisitions to overcome poor signal-to-noise ratio (SNR), sodium ( Na) magnetic resonance imaging (MRI) is an intriguing area of research due to its essential role in human metabolism. Low SNR images can impact the measurement of the point-spread function (PSF) by adding uncertainty into the resulting quantities. Here, we present methods to calculate the PSF by using the modulation transfer function (MTF), and a 3D-printed line-pair phantom in the context of Na MRI.