Publications by authors named "R P van Heeswijk"
Magnetic resonance spectroscopic imaging (MRSI) enables the simultaneous noninvasive acquisition of MR spectra from multiple spatial locations inside the brain. Although H-MRSI is increasingly used in the human brain, it is not yet widely applied in the preclinical setting, mostly because of difficulties specifically related to very small nominal voxel size in the rat brain and low concentration of brain metabolites, resulting in low signal-to-noise ratio (SNR). In this context, we implemented a free induction decay H-MRSI sequence (H-FID-MRSI) in the rat brain at 14.
View Article and Find Full Text PDFPurpose: To implement a flexible framework, named HydrOptiFrame, for the design and optimization of time-efficient water-excitation (WE) RF pulses using B-spline interpolation, and to characterize their lipid suppression performance.
Methods: An evolutionary optimization algorithm was used to design WE RF pulses. The algorithm minimizes a composite loss function that quantifies the fat-water contrast using Bloch equation simulations.
Article Synopsis
- The study aimed to evaluate the effectiveness of two blind source separation techniques (SOBI and ICA) against principal component analysis (PCA) for identifying cardiac triggers in 5D whole-heart MRI.
- Data was collected from three different groups: healthy volunteers, congenital heart disease patients, and patients with suspected coronary artery disease, each undergoing MRI scans with different protocols.
- Results showed SOBI provides more accurate and sharper cardiac triggers compared to PCA and ICA, demonstrating its reliability across varying patient conditions and noise levels.
Background: Cardiovascular magnetic resonance imaging (CMR) faces challenges due to the interference of bright fat signals in visualizing structures, such as coronary arteries. Effective fat suppression is crucial, especially when using whole-heart CMR techniques. Conventional methods often fall short due to rapid fat signal recovery, leading to residual fat content hindering visualization.
View Article and Find Full Text PDFPurpose: This retrospective study aimed to validate the ACS NSQIP Surgical Risk Calculator (SCR) to predict 30-day postoperative outcomes in patients with one of the following subacute orthopedic trauma diagnoses; multiple rib fractures, pelvic ring/acetabular fracture, or unilateral femoral fracture.
Methods: Data of patients with these diagnoses treated between January 1, 2015 and September 19, 2020 were extracted from the patients' medical files. Diagnostic performance, discrimination, calibration, and accuracy of the ACS NSQIP SRC to predict specific outcomes developing within 30 days after surgery was determined.