Sparse-representation-based direct minimum L (p) -norm algorithm for MRI phase unwrapping.

Comput Math Methods Med

School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, QLD 4072, Australia.

Published: December 2014

A sparse-representation-based direct minimum L (p) -norm algorithm is proposed for a two-dimensional MRI phase unwrapping. First, the algorithm converts the weighted-L (p) -norm-minimization-based phase unwrapping problem into a linear system problem whose system (coefficient) matrix is a large, symmetric one. Then, the coefficient-matrix is represented in the sparse structure. Finally, standard direct solvers are employed to solve this linear system. Several wrapped phase datasets, including simulated and MR data, were used to evaluate this algorithm's performance. The results demonstrated that the proposed algorithm for unwrapping MRI phase data is reliable and robust.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3984868PMC
http://dx.doi.org/10.1155/2014/134058DOI Listing

Publication Analysis

Top Keywords

mri phase
12
phase unwrapping
12
sparse-representation-based direct
8
direct minimum
8
minimum -norm
8
-norm algorithm
8
linear system
8
phase
5
algorithm
4
algorithm mri
4

Similar Publications

Role of Cardiovascular MR Imaging and MR Angiography in Patients with Pulmonary Vascular Disease.

Radiol Clin North Am

March 2025

Radiology Department, Northwestern University Feinberg School of Medicine, Arkes Pavilion, 676 North St Clair Street, Suite 800, Chicago, IL 60611, USA. Electronic address:

Cardiac MR imaging and pulmonary MR angiography (MRA) are important clinical tools for the assessment of pulmonary vascular diseases. There are evolving noncontrast and contrast-enhanced techniques to evaluate pulmonary vasculature. Pulmonary MRA is a feasible imaging alternative to CTA in pulmonary embolism detection.

View Article and Find Full Text PDF

Purpose: To improve the current method for MRI turbulence quantification which is the intravoxel phase dispersion (IVPD) method. Turbulence is commonly characterized by the Reynolds stress tensor (RST) which describes the velocity covariance matrix. A major source for systematic errors in MRI is the sequence's sensitivity to the variance of the derivatives of velocity, such as the acceleration variance, which can lead to a substantial measurement bias.

View Article and Find Full Text PDF

Magnetic resonance electrical properties tomography can extract the electrical properties of in-vivo tissue. To estimate tissue electrical properties, various reconstruction algorithms have been proposed. However, physics-based reconstructions are prone to various artifacts such as noise amplification and boundary artifact.

View Article and Find Full Text PDF

Purpose: To explore the evaluation value of contrast enhanced ultrasound (CEUS) quantitative parameters in ischemic-type biliary lesions after liver transplantation to assist its early-diagnosis.

Methods: Patients who underwent liver transplantation and intravenous CEUS at Beijing Friendship Hospital, Capital Medical University from June 25, 2020 to December 28, 2022 and were diagnosed with Ischemic-type biliary lesions (ITBLs) by Magnetic Resonance Cholangiopancreatography (MRCP) or Endoscopic Retrograde Cholangiopancreatography (ERCP) or Percutaneous Transhepatic Cholangiography (PTC) were prospectively enrolled. SonoLiver software was used to quantitatively analyze the contrast images, transplanted livers with normal biliary tracts as the control group.

View Article and Find Full Text PDF

Objectives: The Scrotal and Penile Imaging Working Group (SPIWG) of the European Society of Urogenital Radiology (ESUR) aimed to formulate recommendations on the imaging modalities and minimal technical requirements for abdominopelvic imaging in the follow-up of adult patients treated for testicular germ-cell tumors (TGCT).

Methods: The SPIWG members performed an extensive literature search, reviewed the current clinical practice, and reached a consensus based on the opinions of experts in the field.

Results: Recurrence in patients treated for TGCT mainly occurs in retroperitoneal lymph nodes (LNs).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!