Chinook salmon (Oncorhynchus tshawytscha) farmed in New Zealand are known to develop abnormal spinal curvature late in seawater production. Its cause is presently unknown, but there is evidence to suggest a neuromuscular pathology. Using magnetic resonance imaging (MRI), we evaluated the relationship between soft tissue pathology and spinal curvature in farmed Chinook salmon.
View Article and Find Full Text PDFBackground: Left ventricular (LV) global longitudinal strain (GLS) has been proposed as an early imaging biomarker of cardiac mechanical dysfunction.
Objective: To assess the impact of angiotensin-converting enzyme (ACE) inhibitor treatment of hypertensive heart disease on LV GLS and mechanical function.
Methods: The spontaneously hypertensive rat (SHR) model of hypertensive heart disease ( n = 38) was studied.
Background: The societal cost of shoulder disabilities in our aging society keeps rising. Providing biomarkers of early changes in the microstructure of rotator cuff (RC) muscles might improve surgical planning. Elevation angle (E1A) and pennation angle (PA) assessed by ultrasound change with RC tears.
View Article and Find Full Text PDFRadiomics of pancreas magnetic resonance (MR) images is positioned well to play an important role in the management of diseases characterized by diffuse involvement of the pancreas. The effect of image pre-processing configurations on these images has been sparsely investigated. Fifteen individuals with definite chronic pancreatitis (an exemplar diffuse disease of the pancreas) and 15 healthy individuals were included in this age- and sex-matched case-control study.
View Article and Find Full Text PDFPhys Eng Sci Med
September 2022
Magnetic resonance imaging (MRI) guided cardiac radioablation (CR) for atrial fibrillation (AF) is a promising treatment concept. However, the visibility of AF CR targets on MRI acquisitions requires further exploration and MRI sequence and parameter optimization has not yet been performed for this application. This pilot study explores the feasibility of MRI-guided tracking of AF CR targets by evaluating AF CR target visualization on human participants using a selection of 3D and 2D MRI sequences.
View Article and Find Full Text PDFBackground: Radiomics of the pancreas has the potential to personalize the management of patients with diseases that are characterized by diffuse involvement of the pancreas. However, to date, radiomics features that are both clinically useful and reproducible have not been reported.
Methods: Individuals with definite chronic pancreatitis and healthy individuals, matched on sex and age, were prospectively recruited and underwent T1-weighted magnetic resonance imaging of the pancreas at 3T.
Background And Purpose: Atrial fibrillation (AF) cardiac radioablation (CR) challenges radiotherapy tracking: multiple small targets close to organs-at-risk undergo rapid differential cardiac contraction and respiratory motion. MR-guidance offers a real-time target tracking solution. This work develops and investigates MRI-guided tracking of AF CR targets with cardiac-induced motion.
View Article and Find Full Text PDFPurpose: The safe delivery of cardiac radioablation (CR) for atrial fibrillation (AF) is challenged by multi-direction target motion, cardiac rate variability, target proximity to critical structures, and the importance of complete target dose coverage for therapeutic benefit. Careful selection of appropriate treatment procedures is therefore essential. This work characterizes AF cardiac radioablation target motion and target proximity to surrounding structures in both healthy and AF participants to guide optimal treatment technique and technology choice.
View Article and Find Full Text PDFObjectives: To systematically review published studies on the use of radiomics of the pancreas.
Methods: The search was conducted in the MEDLINE database. Human studies that investigated the applications of radiomics in diseases of the pancreas were included.
Purpose: Common types of congenital heart disease exhibit a variety of structural and functional variations which may be accompanied by changes in the myocardial microstructure. We aimed to compare myocardial architecture from magnetic resonance diffusion tensor imaging (DTI) in preserved pathology specimens.
Materials And Methods: Pathology specimens (n = 24) formalin-fixed for 40.
Vitreous liquefactive processes play an integral role in ocular health. Knowledge of the degree of liquefaction would allow better monitoring of ocular disease progression and enable more informed therapeutic dosing for an individual patient. Presently this process cannot be monitored in a non-invasive manner.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2019
We investigated if blood flow changes induced through the presence of a stent could be detected using in vitro dynamically scaled 4D Phase-Contrast Magnetic Resonance Imaging (PC-MRI). Using idealized and patient-specific left main coronary artery bifurcations, we 3D-printed the dynamically large scaled geometries and incorporated them into a flow circuit for non-invasive acquisition with a higher effective spatial resolution. We tested the effects of using non-Newtonian and Newtonian fluids for the experiment.
View Article and Find Full Text PDFBackground: Optimizing intranasal distribution and retention of nasal sprays is essential in the management of patients with chronic rhinosinusitis (CRS), including those that have had functional endoscopic sinus surgery (FESS). Despite multiple existing distribution studies, there remains a need for a technique that allows regionalization of particle deposition within a patient's unique 3-dimensional (3D) geometry without exposing the patient to radiation.
Methods: Seven participants delivered normal saline containing a gadolinium-based contrast agent (GBCA) by either saline irrigation or nasal sprays on 1 side of the nasal cavity.
Mice with a targeted mutation in the pro-opiomelanocortin (Pomc) gene (Pomctm1/tm1 mice) are unable to synthesize desacetyl-α-MSH and α-MSH and they develop obesity when fed chow diet. In this study, we hypothesized that a chronic high-fat (HF) diet exacerbates Pomctm1/tm1 mouse obesity. Male and female Pomcwt/wt and Pomctm1/tm1 mice were fed low-fat (LF) (10 kcal percent fat) or HF (45 kcal percent fat) diets from weaning for 23 weeks.
View Article and Find Full Text PDFSustained lidocaine release via a thermoresponsive poloxamer-based in situ gelling system has the potential to alleviate pain following knee arthroplasty. A previously developed formulation showed a promising drug release profile in synthetic phosphate-buffered saline (PBS). To support the translation of this formulation, ex vivo characterisation was warranted.
View Article and Find Full Text PDFApproximately 1% of all babies are born with some form of congenital heart defect. Many serious forms of CHD can now be surgically corrected after birth, which has led to improved survival into adulthood. However, many patients require serial monitoring to evaluate progression of heart failure and determine timing of interventions.
View Article and Find Full Text PDFObjective: Regulation of energy balance depends on pro-opiomelanocortin (POMC)-derived peptides and melanocortin-4 receptor (MC4R). Alpha-melanocyte stimulating hormone (α-MSH) is the predicted natural POMC-derived peptide that regulates energy balance. Desacetyl-α-MSH, the precursor for α-MSH, is present in brain and blood.
View Article and Find Full Text PDFIEEE J Biomed Health Inform
September 2017
Cardiac magnetic resonance perfusion examinations enable noninvasive quantification of myocardial blood flow. However, motion between frames due to breathing must be corrected for quantitative analysis. Although several methods have been proposed, there is a lack of widely available benchmarks to compare different algorithms.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
August 2016
Congenital heart disease is the most common birth defect, with an incidence of 75 in every 1000 births. As a result of improved interventions, 90% of people with congenital heart disease now survive to adulthood. They must undergo regular imaging to assess their biventricular (left and right ventricular) function.
View Article and Find Full Text PDFWith the advent of large-scale imaging studies and big health data, and the corresponding growth in analytics, machine learning and computational image analysis methods, there are now exciting opportunities for deepening our understanding of the mechanisms and characteristics of heart disease. Two emerging fields are computational analysis of cardiac remodelling (shape and motion changes due to disease) and computational analysis of physiology and mechanics to estimate biophysical properties from non-invasive imaging. Many large cohort studies now underway around the world have been specifically designed based on non-invasive imaging technologies in order to gain new information about the development of heart disease from asymptomatic to clinical manifestations.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
August 2015
Survival rates for infants with congenital heart disease (CHD) are improving, resulting in a growing population of adults with CHD. However, the analysis of left and right ventricular function is very time-consuming owing to the variety of congenital morphologies. Efficient customization of patient geometry and function depends on high quality shape templates specifically designed for the application.
View Article and Find Full Text PDFJ Magn Reson Imaging
November 2015
Purpose: To investigate the potential patient risk and interactions between a prototype implantable pressure monitoring device and a 3T clinical magnetic resonance imaging (MRI) machine to guide device design towards MR Conditional safety approval.
Materials And Methods: The pressure monitor device contained a catheter-mounted piezo-resistive pressure sensor, rechargeable battery, wireless communication system, and inductive pickup coil. Standard testing methods were used to guide experiments to investigate static field induced force and torque, radiofrequency (RF)-induced heating, image artifacts, and the MR's effect on device function.
Purpose: To quantify spatial and temporal inflammation-induced changes in vascular permeability and macrophage infiltration in guinea-pig (GP) cochlea using MRI.
Materials And Methods: GPs were injected with lipopolysaccharide (LPS) to induce cochlear inflammation. One group was injected with a gadolinium based contrast agent (GBCA) and dynamic contrast enhanced (DCE)-MRI was performed at 4, 7, and 10 days after LPS treatment.
Background: Defective copper regulation is implicated as a causative mechanism of organ damage in diabetes. Treatment with trientine, a divalent-copper-selective chelator, improves arterial and renal structure/function in diabetes, wherein it also ameliorates left-ventricular (LV) hypertrophy. However, direct in vivo evidence that trientine can improve cardiac function in heart failure has hitherto been lacking.
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
June 2012
It has been proposed that in the absence of blood supply, the ocular lens operates an internal microcirculation system that delivers nutrients to internalized fiber cells faster and more efficiently than would occur by passive diffusion alone. To visualize the extracellular space solute fluxes potentially generated by this system, bovine lenses were organ cultured in artificial aqueous humor (AAH) for 4 h in the presence or absence of two gadolinium-based contrast agents, ionic Gd(3+), or a chelated form of Gd(3+), Gd-diethylenetriamine penta-acetic acid (Gd-DTPA; mol mass = 590 Da). Contrast reagent penetration into the lens core was monitored in real time using inversion recovery-spin echo (IR-SE) magnetic resonance imaging (MRI), while steady-state accumulation of [Gd-DTPA](-2) was also determined by calculating T1 values.
View Article and Find Full Text PDF