Category Ranking
98%
Total Visits
921
Avg Visit Duration
2 minutes
Citations
20
Article Abstract
Objectives: To investigate a multimodal, multiparametric perfusion MRI / 18F-fluoro-deoxyglucose-(18F-FDG)-PET imaging protocol for monitoring regorafenib therapy effects on experimental colorectal adenocarcinomas in rats with immunohistochemical validation.
Materials And Methods: Human colorectal adenocarcinoma xenografts (HT-29) were implanted subcutaneously in n = 17 (n = 10 therapy group; n = 7 control group) female athymic nude rats (Hsd:RH-Foxn1rnu). Animals were imaged at baseline and after a one-week daily treatment protocol with regorafenib (10 mg/kg bodyweight) using a multimodal, multiparametric perfusion MRI/18F-FDG-PET imaging protocol. In perfusion MRI, quantitative parameters of plasma flow (PF, mL/100 mL/min), plasma volume (PV, %) and endothelial permeability-surface area product (PS, mL/100 mL/min) were calculated. In 18F-FDG-PET, tumor-to-background-ratio (TTB) was calculated. Perfusion MRI parameters were correlated with TTB and immunohistochemical assessments of tumor microvascular density (CD-31) and cell proliferation (Ki-67).
Results: Regorafenib significantly (p<0.01) suppressed PF (81.1±7.5 to 50.6±16.0 mL/100mL/min), PV (12.1±3.6 to 7.5±1.6%) and PS (13.6±3.2 to 7.9±2.3 mL/100mL/min) as well as TTB (3.4±0.6 to 1.9±1.1) between baseline and day 7. Immunohistochemistry revealed significantly (p<0.03) lower tumor microvascular density (CD-31, 7.0±2.4 vs. 16.1±5.9) and tumor cell proliferation (Ki-67, 434.0 ± 62.9 vs. 663.0 ± 98.3) in the therapy group. Perfusion MRI parameters ΔPF, ΔPV and ΔPS showed strong and significant (r = 0.67-0.78; p<0.01) correlations to the PET parameter ΔTTB and significant correlations (r = 0.57-0.67; p<0.03) to immunohistochemical Ki-67 as well as to CD-31-stainings (r = 0.49-0.55; p<0.05).
Conclusions: A multimodal, multiparametric perfusion MRI/PET imaging protocol allowed for non-invasive monitoring of regorafenib therapy effects on experimental colorectal adenocarcinomas in vivo with significant correlations between perfusion MRI parameters and 18F-FDG-PET validated by immunohistochemistry.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4323201 | PMC |
| http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0115543 | PLOS |
Publication Analysis
Top Keywords
Similar Publications
A Multimodal Observational Case-Control Study Exploring Gut Microbiota-Hippocampus Alterations in Individuals With High Positive Schizotypy From the General Population.
Biol Psychiatry Glob Open Sci
November 2025
University of Basel, Department of Clinical Research (DKF), University Psychiatric Clinics, Translational Neurosciences, Basel, Switzerland.
Background: The hippocampus plays a critical role in psychosis, with reduced volume observed across the psychosis continuum. These structural changes are associated with cognitive deficits, symptom severity, and increased risk of psychosis progression. Elevated hippocampal perfusion and glutamate/GABA (gamma-aminobutyric acid) imbalance further suggest metabolic dysregulation as a key mechanism.
View Article and Find Full Text PDFWindow of opportunity evaluation of blood-brain barrier permeability heterogeneity within and across high-grade glioma patients.
Neuro Oncol
September 2025
Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA.
Background: Disruption of the blood-brain barrier (BBB) in high-grade brain tumors is characterized by contrast accumulation on diagnostic imaging. This window of opportunity study correlates contrast imaging features with the tumor distribution of BBB-permeable (levetiracetam) and -impermeable (cefazolin) drugs.
Methods: Patients with a clinical diagnosis of a high-grade brain tumor underwent MRI for surgical planning.
Value of CMR-derived Quantitative Myocardial Blood Flow Assessment in The Setting of Chronic Coronary Occlusion.
Eur Heart J Cardiovasc Imaging
September 2025
Bosch Health Campus, Robert Bosch Hospital, Department of Cardiology and Angiology, Stuttgart, Germany.
Aims: For many years, visual assessment has been the mainstay of detecting obstructive coronary artery disease (CAD) by stress perfusion cardiovascular magnetic resonance (S-CMR). Recently, fully automated quantitative assessment of myocardial blood flow (MBF) has been introduced. The value of MBF quantification in patients with coronary chronic total occlusion (CTO) is unknown.
View Article and Find Full Text PDFVisually assessed ischaemia on cardiac magnetic resonance, but not quantitative perfusion metrics, predicts symptomatic improvement in coronary artery bypass.
J Cardiovasc Magn Reson
September 2025
Royal Brompton and Harefield Hospitals, part of Guy's and St Thomas' NHS Foundation Trust, London, UK; National Heart and Lung Institute, Imperial College London, UK. Electronic address:
Background: Serial perfusion cardiovascular magnetic resonance (CMR) in symptomatic patients undergoing coronary artery bypass grafting (CABG) may provide mechanistic insight into dynamic abnormalities of the myocardium.
Objectives: To assess how changes in cardiac reperfusion and remodelling associate with symptom improvement in patients undergoing CABG METHODS: Patients awaiting elective CABG completed serial quality of life questionnaires and detailed CMR at baseline and at 6-12 months post CABG as per protocol. Automated fully quantitative stress and rest myocardial blood flow was calculated, alongside assessment of the visual ischaemic burden.
The Role of MRI in Debunking the Fallacy of "Mild" Traumatic Brain Injury.
J Magn Reson Imaging
September 2025
Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University Grossman School of Medicine, New York, New York, USA.
Mild traumatic brain injury (mTBI) is a prevalent yet often overlooked public health concern due to the absence of detectable abnormalities on CT or conventional MRI scans. Approximately 18.3%-31.
View Article and Find Full Text PDF