MR contrast synthesis for lesion segmentation

The magnetic resonance contrast of a neuroimaging data set has strong impact on the utility of the data in image analysis tasks, such as registration and segmentation. Lengthy acquisition times often prevent routine acquisition of multiple MR contrast images, and opportunities for detailed analysis using these data would seem to be irrevocably lost. This paper describes an example based approach which uses patch matching from a multiple contrast atlas with the intended goal of generating an alternate MR contrast image, thus effectively simulating alternative pulse sequences from one another. In this paper, we deal specifically with Fluid Attenuated Inversion Recovery (FLAIR) sequence generation from T1 and T2 pulse sequences. The applicability of this synthetic FLAIR for estimating white matter lesions segmentation is demonstrated.

1. Introduction

A principal goal of the collaboration between the neuroscience and medical imaging communities is the accurate segmentation of brain structures, with a view towards offering insight about the normal and abnormal features of a brain. Several methods [1], [2] have been proposed to find cortical and sub-cortical structures. These methods are intrinsically dependent on the modality and the contrast between tissues. In this paper, we propose a method to alter the modality of a magnetic resonance (MR) image, thereby changing intrinsic contrast.