Comparison of Models and Contrast Agents for Improved Signal and Signal Linearity in Dynamic Contrast-Enhanced Pulmonary Magnetic Resonance Imaging

Abstract

Motives To compare pulmonary blood flow (PBF) measurements acquired with three previously published models (low dose "single bolus", "dual bolus", and a "non-linear correction" algorithm) for addressing the non-linear relationship between contrast agent concentration and MR signal in the arterial input function (AIF), and to compare both lung signal and PBF measurements obtained using Gd-DTPA (Magnevist) with those obtained using the high-relaxivity agent Gd-BOPTA (Multihance). Materials and Methods Ten out of twelve healthy humans were successfully scanned on two consecutive days at 1.5T. Contrast-enhanced pulmonary perfusion scans were acquired with a 3D spoiled gradient echo pulse sequence and interleaved variable density k-space sampling with a 1s frame rate and 4×4×4 mm3 resolution. Each day, two perfusion scans were acquired with either Gd-DTPA or Gd-BOPTA; the order of the administered contrast agent was randomized. ROI analysis was used to determine PBF based on indicator dilution theory. Linear Mixed Effects Modeling was used to compare the AIF models and contrast agents. Results With Gd-DTPA, no significant differences were observed between the mean PBF calculated for the "single bolus" (323 ± 110 ml/100ml/min), "dual bolus" (315 ± 177 ml/100ml/min), and "non-linear correction" (298 ± 100 ml/100ml/min) approach. With Gd-BOPTA, the mean PBF using the "dual bolus" approach (245 ± 103 ml/100ml/min) was lower than with the "single bolus" (345 ± 130 ml/100ml/min, p < 0.01) and "non-linear correction" (321 ± 115 ml/100ml/min, p = 0.02). Peak lung enhancement was significantly higher in all regions with Gd-BOPTA than with Gd-DTPA (p << 0.01). Conclusion The “dual bolus” approach with Gd-BOPTA resulted in a significantly lower PBF than the other combinations of contrast agent and AIF model. No other statistically significant differences were found. Given the much higher signal in the lung parenchyma using Gd-BOPTA, the use of Gd-BOPTA with either single bolus or the non-linear correction method appears most promising for voxel-wise perfusion quantification using 3D dynamic contrast enhanced pulmonary perfusion MRI.

Imaging of Pulmonary Hypertension in Adults: A Position Paper from the Fleischner Society

“…Automated quantification of regional lung blood volume determined with dual-energy CT may also be an option to evaluate changes in regional blood flow and show any new or residual defects in the blood volume (iodine) maps (111). Dynamic contrast-enhanced MRI perfusion imaging can provide qualitative and semiquantitative assessment of pulmonary perfusion and shows promise for quantitative mapping of pulmonary perfusion in CTEPH (112). Dynamic contrast-enhanced perfusion methods have been used to demonstrate improvement in regional perfusion parameters, regional blood flow, regional blood volume, and mean pulmonary transit time in patients with CTEPH undergoing BPA (113).…”

Towards quantitative perfusion MRI of the lung in COPD: The problem of short-term repeatability

“…As a consequence, the effects of short-term influences like the administration of oxygen in this study, may be obscured by the biases introduced by residual contrast, which cannot be compensated for by the currently available experimental setup and software. More recently, corrections for the non-linearity of AIF signal have been proposed and may reduce this bias contribution [26].…”

Dynamic Contrast-Enhanced Magnetic Resonance Imaging for Quantitative Lung Perfusion Imaging Using the Dual-Bolus Approach

“…A dualhead MR power injector (Spectris Solaris EP; Medrad, Volkach, Germany) was used for injection of contrast into a left antecubital vein with a flow of 4 mL/s. 16,22 …”