Ultra-Short Echo Time

We are developing structural and functional imaging of lungs using ultra-short echo time (UTE) techniques.

Chronic lung diseases such as COPD affect lungs non-uniformly by disrupting pulmonary ventilation and perfusion. Among various imaging modalities, MRI can be used to monitor disease progression and therapeutic response without concerns for repeated exposures to ionizing radiation. However, a primary challenge of lung MRI is the short T2* of the lung tissue due to air/tissue interface.

Short TE
Short TE (140 µs) images of the lungs acquired in the coronal (a) and reformatted into sagittal (b) and axial orientations on a Philips 3 T Ingenia scanner. The difference images (d-f), between the short TE (140 µs) and the long TE (2.2 ms) images show exquisite signal of the lungs.

We are currently exploring various novel 3D UTE acquisitions for volumetric structural imaging of the lungs while minimizing the signal loss due to short T2* relaxation. We are also developing oxygen-enhanced MRI using 3D UTE for functional imaging by generating pulmonary ventilation maps.

Three-dimensional ventilation map of the lungs measured as a percentage signal enhancement (PSE) between room air (21% O2) and 100% O2 acquired in the coronal orientation, showing progressive PSE threshold maps. Whole lung average PSE was measured to be 6.8% and is slightly lower than the theoretically predicted value of 7.4%.