Repeatability of tumor perfusion kinetics from dynamic contrast-enhanced MRI in glioblastoma

Abstract Background Dynamic contrast-enhanced MRI (DCE-MRI) parameters have been shown to be biomarkers for treatment response in glioblastoma (GBM). However, variations in analysis and measurement methodology complicate determination of biological changes measured via DCE. The aim of this study is to quantify DCE-MRI variations attributable to analysis methodology and image quality in GBM patients. Methods The Extended Tofts model (eTM) and Leaky Tracer Kinetic Model (LTKM), with manually and automatically segmented vascular input functions (VIFs), were used to calculate perfusion kinetic parameters from 29 GBM patients with double-baseline DCE-MRI data. DCE-MRI images were acquired 2–5 days apart with no change in treatment. Repeatability of kinetic parameters was quantified with Bland–Altman and percent repeatability coefficient (%RC) analysis. Results The perfusion parameter with the least RC was the plasma volume fraction (vp), with a %RC of 53%. The extra-cellular extra-vascular volume fraction (ve) %RC was 82% and 81%, for extended Tofts-Kety Model (eTM) and LTKM respectively. The %RC of the volume transfer rate constant (Ktrans) was 72% for the eTM, and 82% for the LTKM, respectively. Using an automatic VIF resulted in smaller %RCs for all model parameters, as compared to manual VIF. Conclusions As much as 72% change in Ktrans (eTM, autoVIF) can be attributable to non-biological changes in the 2–5 days between double-baseline imaging. Poor Ktrans repeatability may result from inferior temporal resolution and short image acquisition time. This variation suggests DCE-MRI repeatability studies should be performed institutionally, using an automatic VIF method and following quantitative imaging biomarkers alliance guidelines.

Download Full-text

Applications of Dynamic Contrast Enhanced MRI in Oncology: Measurement of Tumor Oxygen Tension

Technology in Cancer Research & Treatment ◽

10.1177/153303460200100104 ◽

2002 ◽

Vol 1 (1) ◽

pp. 29-38 ◽

Cited By ~ 17

Author(s):

Z. Wang ◽

M-Y. Su ◽

O. Nalcioglu

Keyword(s):

Oxygen Tension ◽

Volume Fraction ◽

Vascular Volume ◽

Dce Mri ◽

Dynamic Contrast Enhanced Mri ◽

Dynamic Contrast Enhanced ◽

Enhanced Mri ◽

Proposed Model ◽

Contrast Enhanced ◽

Contrast Enhanced Mri

A new model based on an extension of the Krogh's cylindrical model was developed to calculate tumor oxygen tension ( pO2) from the H-1 dynamic contrast enhanced MRI (DCE-MRI) measurements. The model enables one to calculate the tumor pO2 using the vascular volume fraction (fb) obtained by the DCE-MRI. The proposed model has three parameters. For small values of fb one assumes that there exists a linear relationship between and fb. The constant of proportionality in this case is given by C1 — the oxygen tension per vascular volume fraction. For larger values of fb a modified version of Krogh model using two parameters is developed and here C2 — is the integrated blood oxygen tension, and C3 -given by the combination of the oxygen diffusion coefficient, solubility of oxygen in the tissue, capillary radius, and tissue metabolic consumption rate. The parameters of the model can be determined by performing simultaneous in-vivo F-19 MRI oxygen tension measurement and dynamic Gd-DTPA enhanced MRI on the same tumor. Dynamic MRI data can be used with a compartmental model to calculate tumor vascular volume fraction on a pixel by pixel basis. Then tumor oxygen tension map can be calculated from the vascular volume fraction by the extended Krogh model as described above. In the present work, the model parameters were determined using three rats bearing Walker-256 tumors and performing simultaneous F-19 and DCE MRI on the same tumor. The parameters obtained by fitting the model equation to the experimental data were: C1 = 983.2+ 133.2torr, C2 = 58.20 + 2.4 torr, and C3 = 1.7 + 0.1 torr. The performance of the extended Krogh model was then tested on two additional rats by performing both F-19 and DCE-MRI studies and calculating the pO2 (H-1) using the model and comparing it with the pO2 (F-19) obtained from the F-19 MRI. It was found that the measurements obtained by both techniques had a high degree of correlation [ pO2 (H-1) = (1.01 + 0.07) pO2 (F-19) + (0.91 + 0.05) and r=0.96], indicating the applicability of the proposed model in determining pO2 from the DCE-MRI.

Download Full-text

Dynamic contrast-enhanced MRI of synovitis in knee osteoarthritis: repeatability, discrimination and sensitivity to change in a prospective experimental study

European Radiology ◽

10.1007/s00330-021-07698-z ◽

2021 ◽

Author(s):

James W. MacKay ◽

Faezeh Sanaei Nezhad ◽

Tamam Rifai ◽

Joshua D. Kaggie ◽

Josephine H. Naish ◽

...

Keyword(s):

Knee Osteoarthritis ◽

Experimental Medicine ◽

Sensitivity To Change ◽

Dce Mri ◽

Dynamic Contrast Enhanced Mri ◽

Knee Oa ◽

Dynamic Contrast Enhanced ◽

Enhanced Mri ◽

Contrast Enhanced ◽

Contrast Enhanced Mri

Abstract Objectives Evaluate test-retest repeatability, ability to discriminate between osteoarthritic and healthy participants, and sensitivity to change over 6 months, of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) biomarkers in knee OA. Methods Fourteen individuals aged 40–60 with mild-moderate knee OA and 6 age-matched healthy volunteers (HV) underwent DCE-MRI at 3 T at baseline, 1 month and 6 months. Voxelwise pharmacokinetic modelling of dynamic data was used to calculate DCE-MRI biomarkers including Ktrans and IAUC60. Median DCE-MRI biomarker values were extracted for each participant at each study visit. Synovial segmentation was performed using both manual and semiautomatic methods with calculation of an additional biomarker, the volume of enhancing pannus (VEP). Test-retest repeatability was assessed using intraclass correlation coefficients (ICC). Smallest detectable differences (SDDs) were calculated from test-retest data. Discrimination between OA and HV was assessed via calculation of between-group standardised mean differences (SMD). Responsiveness was assessed via the number of OA participants with changes greater than the SDD at 6 months. Results Ktrans demonstrated the best test-retest repeatability (Ktrans/IAUC60/VEP ICCs 0.90/0.84/0.40, SDDs as % of OA mean 33/71/76%), discrimination between OA and HV (SMDs 0.94/0.54/0.50) and responsiveness (5/1/1 out of 12 OA participants with 6-month change > SDD) when compared to IAUC60 and VEP. Biomarkers derived from semiautomatic segmentation outperformed those derived from manual segmentation across all domains. Conclusions Ktrans demonstrated the best repeatability, discrimination and sensitivity to change suggesting that it is the optimal DCE-MRI biomarker for use in experimental medicine studies. Key Points • Dynamic contrast-enhanced MRI (DCE-MRI) provides quantitative measures of synovitis in knee osteoarthritis which may permit early assessment of efficacy in experimental medicine studies. • This prospective observational study compared DCE-MRI biomarkers across domains relevant to experimental medicine: test-retest repeatability, discriminative validity and sensitivity to change. • The DCE-MRI biomarker Ktransdemonstrated the best performance across all three domains, suggesting that it is the optimal biomarker for use in future interventional studies.

Download Full-text