Quantitative perfusion mapping of the human lung using 1H spin labeling

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Pulmonary Physiology
• Medical Imaging Techniques

Background:

• Pulmonary perfusion assessment is crucial for diagnosing and monitoring lung diseases.
• Current methods for pulmonary perfusion imaging often involve contrast agents or are less quantitative.
• Developing noninvasive, rapid, and quantitative techniques is essential for improved patient care.

Purpose of the Study:

• To evaluate the feasibility and reproducibility of a novel noninvasive, rapid, and quantitative pulmonary perfusion mapping method.
• To utilize a two-compartment tissue model combined with (1)H spin labeling for lung perfusion assessment.
• To establish a contrast-agent-free approach for pulmonary perfusion imaging.

Main Methods:

• Employed a 1.5-T whole-body MRI scanner to acquire global and selective lung T(1) maps using an inversion recovery Snapshot FLASH technique.
• Examined ten healthy volunteers and three cystic fibrosis (CF) patients with breath-holds at end-expiration.
• Acquired Gd-DTPA-enhanced (1)H MR perfusion images in CF patients for comparative analysis.

Main Results:

• Successfully calculated quantitative perfusion maps from T(1) maps, with volunteer perfusion rates ranging from 400 to 600 mL/100 g/minute.
• Demonstrated high intra-study reproducibility and low relative errors for the developed method.
• Identified perfusion defects in CF patients using spin labeling, consistent with Gd-DTPA-enhanced MR imaging, with diseased tissue showing rates < 200 mL/100 g/minute.

Conclusions:

• Achieved noninvasive, robust, and quantitative (1)H MR mapping of pulmonary perfusion via rapid lung T(1) mapping and spin labeling.
• The proposed method offers significant potential for qualitative and quantitative assessment of pulmonary perfusion in various lung diseases.
• This technique eliminates the need for contrast agents, enhancing safety and accessibility for patients.