Background: Subtraction of Dynamic Contrast-Enhanced 3D Magnetic Resonance (DCE-MR) volumes can result in images that depict and accurately characterize a variety of liver lesions. However, the diagnostic utility of subtraction images depends on the extent of co-registration between non-enhanced and enhanced volumes. Movement of liver structures during acquisition must be corrected prior to subtraction. Currently available methods are computer intensive. We report a new method for the dynamic subtraction of MR liver images that does not require excessive computer time.
Methods: Nineteen consecutive patients (median age 45 years; range 37-67) were evaluated by VIBE T1-weighted sequences (TR 5.2 ms, TE 2.6 ms, flip angle 20 degrees , slice thickness 1.5 mm) acquired before and 45s after contrast injection. Acquisition parameters were optimized for best portal system enhancement. Pre and post-contrast liver volumes were realigned using our 3D registration method which combines: (a) rigid 3D translation using maximization of normalized mutual information (NMI), and (b) fast 2D non-rigid registration which employs a complex discrete wavelet transform algorithm to maximize pixel phase correlation and perform multiresolution analysis. Registration performance was assessed quantitatively by NMI.
Results: The new registration procedure was able to realign liver structures in all 19 patients. NMI increased by about 8% after rigid registration (native vs. rigid registration 0.073 +/- 0.031 vs. 0.078 +/- 0.031, n.s., paired t-test) and by a further 23% (0.096 +/- 0.035 vs. 0.078 +/- 0.031, p < 0.001, paired t-test) after non-rigid realignment. The overall average NMI increase was 31%.
Conclusion: This new method for realigning dynamic contrast-enhanced 3D MR volumes of liver leads to subtraction images that enhance diagnostic possibilities for liver lesions.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1564010 | PMC |
| http://dx.doi.org/10.1186/1471-2342-6-5 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Fluorinated Cyclic Olefin Copolymers (COCs) and Cyclic Olefin Polymers (COPs).
Macromol Rapid Commun
January 2025
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun, 130022, China.
The demand for insulating materials with superior dielectric properties has increased. Among these materials, polymers containing cyclic structure including cyclic olefin copolymer (COC) and cyclic olefin polymer (COP) stand out because of their excellent dielectric properties originating from the pure hydrocarbon structure. Introducing fluorine into polymers is one efficient strategy for optimizing the dielectric and the related important properties.
View Article and Find Full Text PDFShape-matching-based fracture reduction aid concept exemplified on the proximal humerus-a pilot study.
Int J Comput Assist Radiol Surg
January 2025
AO Research Institute Davos, Davos, Switzerland.
Purpose: Optimizing fracture reduction quality is key to achieve successful osteosynthesis, especially for epimetaphyseal regions such as the proximal humerus (PH), but can be challenging, partly due to the lack of a clear endpoint. We aimed to develop the prototype for a novel intraoperative C-arm-based aid to facilitate true anatomical reduction of fractures of the PH.
Methods: The proposed method designates the reduced endpoint position of fragments by superimposing the outer boundary of the premorbid bone shape on intraoperative C-arm images, taking the mirrored intact contralateral PH from the preoperative CT scan as a surrogate.
Associations of RANKL levels and polymorphisms with rheumatoid arthritis: A meta-analysis.
PLoS One
January 2025
Department of Rheumatology, Korea University College of Medicine, Seoul, Korea.
Objectives: This study examined the correlation between circulating receptor activator for nuclear factor-κB ligand (RANKL) levels and rheumatoid arthritis (RA), and investigated the association between polymorphisms in the RANKL gene and susceptibility to RA.
Method: We searched the Medline, Embase, and Cochrane databases for relevant publications up to September 2024. A meta-analysis was conducted to assess serum/plasma RANKL levels in patients with RA and controls, and to explore the relationship between RANKL rs9533156 and rs2277438 polymorphisms and RA susceptibility.
Hyaluronic Acid is Associated with Severity and Prognosis in Patients with Community-Acquired Pneumonia.
J Inflamm Res
December 2024
Department of Center of Integrated Traditional Chinese and Western Medicine, Peking University Ditan Teaching Hospital, Beijing, People's Republic of China.
Purpose: Hyaluronic acid (HA) is a novel inflammatory biomarker with a prognostic value for several infectious diseases. This study investigated the association of HA with severity and prognosis in hospitalized patients with community-acquired pneumonia (CAP).
Patients And Methods: We analyzed the differences of HA levels in different groups.
School-Based Physical Activity Program Implementation Is Enhanced With Support From Community-Based Partners.
J Sch Health
January 2025
College of Health, Oregon State University, Corvallis, Oregon, USA.
Background: School-based physical activity (PA) programs are an equitable, evidence-based approach to combat health and PA disparities. This study examined factors associated with implementation of BE Physically Active 2Day (BEPA 2.0), a K-5 school-based PA program, and examined how support from Cooperative Extension via Supplemental Nutrition Assistance Program Education (SNAP-Ed) partners influenced implementation.
View Article and Find Full Text PDFWant 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!