Dynamic pulmonary perfusion and flow quantification with MR imaging, 3.0T vs. 1.5T: initial results

Area of Science:

• Magnetic Resonance Imaging
• Cardiovascular Imaging
• Pulmonary Imaging

Background:

• Pulmonary artery (PA) flow quantification and time-resolved MR angiography (MRA) are crucial for assessing pulmonary circulation.
• Higher magnetic field strengths (3.0T) in MRI may offer improved signal-to-noise ratio (SNR) but can also introduce artifacts.

Purpose of the Study:

• To compare the technical feasibility and performance of pulmonary MRA and PA flow quantification at 3.0T versus 1.5T.
• To evaluate image quality, SNR, and quantitative indices of pulmonary perfusion, flow, and velocity at both field strengths.

Main Methods:

• Prospective evaluation in 14 healthy volunteers.
• Time-resolved contrast-enhanced MRA and main PA flow quantification performed at 1.5T and 3.0T using similar sequence parameters.
• Comparison of image quality, SNR, and quantitative perfusion/flow/velocity indices.

Main Results:

• Successful performance of pulmonary MRA, perfusion, and flow quantification at both 1.5T and 3.0T.
• Comparable pulmonary perfusion and flow indices between the two field strengths (no statistically significant difference).
• Higher SNR for vascular structures at 3.0T (P = 0.001), but significantly lower SNR and definition scores for parenchymal enhancement at 3.0T (P = 0.008 and P = 0.001, respectively).

Conclusions:

• Time-resolved pulmonary MRA, perfusion, and flow quantification at 3.0T are technically feasible with results comparable to 1.5T.
• Reduced parenchymal enhancement at 3.0T is likely due to increased susceptibility effects at higher magnetic fields.
• Further research is needed to optimize pulmonary perfusion imaging at 3.0T and overcome current limitations.