Purpose: To demonstrate the feasibility of three-dimensional thick-partition, contrast-enhanced, catheter-directed coronary artery magnetic resonance angiography (MRA) and test the hypothesis that three-dimensional imaging improves coronary artery background contrast-to-noise ratio (CNR) compared to two-dimensional imaging.
Materials And Methods: Catheters were advanced into the coronary arteries of swine (N = 6) under MR guidance. Three-dimensional coronary MRA was performed after intracoronary injection of a small dose of contrast media using magnetization-prepared steady-state free precession (SSFP) with two thick partitions. For comparison, two magnetization-prepared two-dimensional SSFP scans were also performed, one with no signal averaging and one with two signal averages. All sequences had the same coverage and in-plane spatial resolution.
Results: The coronary artery was successfully catheterized in all (6/6) animals. CNR for three-dimensional imaging was 11.1 +/- 1.2 for proximal arterial segments and 4.3 +/- 0.4 for distal segments. Without averaging, two-dimensional imaging CNRs for proximal and distal segments were 5.0 +/- 0.7 and 1.2 +/- 0.2, respectively. With averaging, two-dimensional imaging CNRs for proximal and distal segments were 9.4 +/- 1.5 and 2.9 +/- 0.4, respectively. Three-dimensional imaging showed a statistically significant increase in CNR over all two-dimensional imaging for both proximal and distal segments (P < 0.05).
Conclusion: Three-dimensional thick-partition, contrast-enhanced, catheter-directed coronary MRA is feasible and improves CNR over two-dimensional projection imaging.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1435989 | PMC |
http://dx.doi.org/10.1002/jmri.20390 | DOI Listing |
Innovations (Phila)
December 2024
Department of Neurosciences and Rehabilitation, Cardiac Surgery Unit, University of Ferrara, Italy.
Objective: Both the en bloc island technique and the branched graft technique (BGT) present advantages but also limitations in aortic arch surgery. Here is the first presentation of an innovative prosthesis for aortic arch replacement, conceived to overcome the disadvantages of both techniques.
Methods: The novel ISLAND graft is a tubular Dacron or hybrid prosthesis with an additional extended Dacron graft ("bubble") on the superior aspect, for en bloc island graft anastomosis.
Bone Rep
March 2025
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States of America.
High resolution peripheral quantitative computed tomography (HRpQCT) offers detailed bone geometry and microarchitecture assessment, including cortical porosity, but assessing chronic kidney disease (CKD) bone images remains challenging. This proof-of-concept study merges deep learning and machine learning to 1) improve automatic segmentation, particularly in cases with severe cortical porosity and trabeculated endosteal surfaces, and 2) maximize image information using machine learning feature extraction to classify CKD-related skeletal abnormalities, surpassing conventional DXA and CT measures. We included 30 individuals (20 non-CKD, 10 stage 3 to 5D CKD) who underwent HRpQCT of the distal and diaphyseal radius and tibia and contributed data to develop and validate four different AI models for each anatomical site.
View Article and Find Full Text PDFJ Cardiovasc Magn Reson
January 2025
Philips Healthcare, Beijing 100600, China.
Background: This study aims to identify optimal acceleration factors (AFs) for compressed sensing (CS) technology to enhance its clinical application for suspected coronary artery disease (CAD) in whole-heart non-contrast coronary magnetic resonance angiography (CMRA).
Methods: Two hundred and seventeen individuals with suspected CAD underwent whole-heart non-contrast CMRA on a 1.5-T CMR scanner with CS AFs of 2, 4, and 6 (CS2, CS4, and CS6).
J Shoulder Elbow Surg
January 2025
Department of Orthopedics and Trauma, Peking University People's Hospital, Beijing 100044, China; Key Laboratory of Trauma and Neural Regeneration (Peking University), Ministry of Education, Beijing 100044, China; National Center for Trauma Medicine, Peking University People's Hospital, Beijing 100044, China. Electronic address:
Objective: The bare area is defined as a transverse region within the trochlear notch, serving as an optimal entry point for olecranon osteotomy due to the absence of articular cartilage coverage. However, there is limited research on the morphology and location of the bare area, and there is a lack of intuitive visual description. Thus, the purpose of this study is to delineate anatomical features of the bare area and visualize its morphology and refine the olecranon osteotomy approach.
View Article and Find Full Text PDFAnimal
December 2024
PEGASE, INRAE, Institut Agro, 35590 Saint Gilles, France. Electronic address:
During digestion, almost 50% of absorbed essential amino acids (AAs) are metabolised by intestinal tissue, thus not appearing directly in the portal vein. This value, which is referred to as first-pass metabolism, seems high in relation to the overall efficiency of AA use considered in growth models. Experimental studies of first-pass metabolism are complicated due to the presence of numerous metabolic fluxes in the intestine and to the dynamics of digestion and absorption.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!