Magnetic Resonance Imaging of Monocrotaline-Induced Pulmonary Hypertension in Rats Using Radial Scanning with...

Area of Science:

• Medical Imaging
• Pulmonary Medicine
• Cardiovascular Research

Background:

• Pulmonary hypertension (PH) significantly alters lung mechanics and function.
• Accurate assessment of lung volume and ventilation is crucial for understanding PH pathophysiology.
• Current imaging techniques may have limitations in dynamic respiratory assessment.

Purpose of the Study:

• To evaluate the efficacy of magnetic resonance imaging (MRI) with radial scanning and retrospective gating for assessing lung function in a rat model of pulmonary hypertension.
• To quantify changes in lung volumes, tidal volume, and fractional ventilation in rats with PH compared to healthy controls.

Main Methods:

• Radial MRI sequences were acquired on intact rat lungs and rat lungs with induced pulmonary hypertension.
• Retrospective gating was applied to reconstruct lung images during inspiratory and expiratory phases.
• Lung volumes, relative tidal volume, and fractional ventilation maps were calculated and analyzed.

Main Results:

• Rats with pulmonary hypertension exhibited significantly increased lung volumes at both inspiration (~4%) and expiration (~18%) compared to intact rats.
• Relative lung tidal volume was markedly reduced by approximately 2.8-fold in the PH group.
• Fractional ventilation maps revealed a substantial decrease (~2.6-fold) in ventilation within pathological lung areas.

Conclusions:

• Retrospective gating in MRI is a valuable tool for detecting and quantifying alterations in lung volume and ventilation associated with pulmonary hypertension.
• This imaging approach can confirm the presence of lung pathology and its detrimental effects on respiratory function.
• The findings support the use of this MRI technique for preclinical research in pulmonary hypertension.