Using super-resolution reconstruction for whole-brain water content mapping in three orthogonal orientations
Dennis Thomas, Ana-Maria Oros-Peusquens, Dirk Poot and N. Jon Shah
21st July 2022
Water content in the healthy brain is tightly regulated, and any alteration in the normal homeostasis is indicative of pathology. Consequently, measuring brain water content is relevant to understanding numerous conditions, including ischemia, brain injuries, hypoxia, brain tumours, multiple sclerosis and hepatic encephalopathy. MRI-based methods offer a way to measure water content with high resolution, thus enabling the detection of small changes in tissue integrity non-invasively and quantitatively. However, the resolution of the current methods are hindered by long acquisition times and partial volume effects.
In response to this problem, researchers at INM-4 have developed a technique to increase the spatial resolution of water content maps by combining information from multiple low-resolution images, a technique commonly termed as a “super-resolution reconstruction” (SRR).
The technique works by reconstructing a high-resolution (HR) multi-echo gradient echo (mGRE) image in super-resolution from three low-resolution (LR) orthogonal mGRE acquisitions, thus enabling subsequent high resolution water content mapping.
The accuracy of the method was demonstrated using phantoms and six healthy subjects at 3 Tesla. The results show that, in addition to providing better contrast, the proposed method was able to increase the resolution of the water content maps in order to facilitate the detection of very small lesions.
It is anticipated that the impact of the method will be accentuated at higher field strengths, where gains in both imaging time and SNR can be expected. Future research will focus on refining the technique and on its eventual clinical implementation.
Origional publication: Whole-Brain Water Content Mapping Using Super-Resolution Reconstruction with MRI Acquisition in 3 Orthogonal Orientations