MRI Technical Developments



     For the CPIR to remain at the cutting edge of pulmonary, cardiology, and airway research, innovative MRI acquisition techniques, reconstruction methods, and hardware must be developed and analyzed. By continuing research in these areas, we can obtain higher quality images, with more useful information, in a shorter amount of time. Below are broad descriptions in which some of our technical development projects are focused. The outcomes from these projects have or will lead to improved characterization of diseases once they become fully developed and implemented.

Proton UTE Imaging:

     One reason imaging of the pulmonary, cardiovascular, and airway systems is difficult is the large amount of intrinsic physiological motion. Thus, MRI acquisition techniques which are robust to motion artifacts is necessary. However, most motion robust techniques require a longer amount of time to acquire a full image. One promising approach to overcome this issue is the use of spiral encoding such as in the FLORET sequence. Another alternative to overcome the motion is acquiring images faster than the intrinsic physiological motion but typically requires much more complicated reconstruction pathways due to the necessary undersampling. Many different techniques are being developed to improve image quality and information while reducing the scan time.


Xenon Imaging:

     Xenon imaging has become one of the main tools of the CPIR due to the information it provides including ventilation defects and alveolar dimensions. However, there is much more information that can be obtained via xenon imaging such as amount of xenon in the barrier, the red blood cell xenon concentration, and much more. This additional information will allow us to visualize defects in perfusion and characterize many other pulmonary diseases which do not exhibit ventilation defects including idiopathic pulmonary fibrosis and pulmonary arterial hypertension.


Xenon Coils:

     Since xenon imaging is a newer but quickly growing field, none of the large MRI manufacturers (Philips, Siemens, GE) have developed xenon coils to detect the signal. Thus, the xenon imaging field must either order imaging coils from other vendors or build their own. While the xenon coils from the other vendors work very well, they are relatively standard and do not implement many of the excellent features of modern proton imaging coils. Thus, in the CPIR, we continue to design and develop xenon coils in order to be on the breaking edge of xenon coil technology. Improved xenon coils will lead to higher signal to noise ratios, more homogenous excitation and detection volumes, larger transmitted RF power and faster acquisitions.