2D Ultrashort Echo-Time Functional Lung Imaging.

Area of Science:

• Medical Imaging
• Radiology
• Pulmonary Medicine

Background:

• Magnetic Resonance Imaging (MRI) of the lung is challenging due to low proton density and rapid T2* relaxation.
• There is a need for MRI methods capable of assessing lung parenchyma and function.

Purpose of the Study:

• To investigate the feasibility of two-dimensional ultrashort echo-time (2D UTE) imaging for lung function assessment.
• To evaluate the applicability of breath-hold (BH) and self-gated (SG) 2D-tyUTE for quantifying lung parameters.

Main Methods:

• Prospective study involving eleven healthy volunteers.
• Utilized 3T, 2D tiny golden angle UTE (2D-tyUTE) sequences.
• Assessed signal-to-noise ratio (SNR), proton fraction (fP), fractional ventilation (FV), and perfusion (f) using BH and SG techniques, comparing smokers and nonsmokers.

Main Results:

• Significant differences in SNR were observed across different BH and SG approaches.
• Proton fraction (fP) in expiration was independent of BH technique but slightly higher with SG.
• Fractional ventilation (FV) was reproducible with BH but lower with SG; a moderate correlation was found between breathing amplitude and FV.
• No significant differences in perfusion were noted between BH and SG.
• Smokers showed significantly higher fP than nonsmokers in expiration.

Conclusions:

• 2D-tyUTE is feasible for quantifying lung function parameters at 3T within clinically acceptable times.
• The technique shows potential for assessing lung parenchyma and function.
• Low spatial resolution in the slice selection direction may impact sensitivity and requires further clinical evaluation.