High Dynamic Range Processing for Magnetic Resonance Imaging

Purpose To minimize feature loss in T 1 - and T 2 -weighted MRI by merging multiple MR images acquired at different T R and T E to generate an image with increased dynamic range. Materials and Methods High Dynamic Range (HDR) processing techniques from the field of photography were applied to a series of acquired MR images. Specifically, a method to parameterize the algorithm for MRI data was developed and tested. T 1 - and T 2 -weighted images of a number of contrast agent phantoms and a live mouse were acquired with varying T R and T E parameters. The images were computationally merged to produce HDR-MR images. All acquisitions were performed on a 7.05 T Bruker PharmaScan with a multi-echo spin echo pulse sequence. Results HDR-MRI delineated bright and dark features that were either saturated or indistinguishable from background in standard T 1 - and T 2 -weighted MRI. The increased dynamic range preserved intensity gradation over a larger range of T 1 and T 2 in phantoms and revealed more anatomical features in vivo . Conclusions We have developed and tested a method to apply HDR processing to MR images. The increased dynamic range of HDR-MR images as compared to standard T 1 - and T 2 -weighted images minimizes feature loss caused by magnetization recovery or low SNR.