A Computer Tool for the Fusion and Visualization of Thermal and Magnetic Resonance Images

Abstract

The measurement of temperature variation along the surface of the body, provided by digital infrared thermal imaging (DITI), is becoming a valuable auxiliary tool for the early detection of many diseases in medicine. However, DITI is essentially a 2-D technique and its image does not provide useful anatomical information associated with it. However, multimodal image registration and fusion may overcome this difficulty and provide additional information for diagnosis purposes. In this paper, a new method of registering and merging 2-D DITI and 3-D MRI is presented. Registration of the images acquired from the two modalities is necessary as they are acquired with different image systems. Firstly, the body volume of interest is scanned by a MRI system and a set of 2-D DITI of it, at orthogonal angles, is acquired. Next, it is necessary to register these two different sets of images. This is done by creating 2-D MRI projections from the reconstructed 3-D MRI volume and registering it with the DITI. Once registered, the DITI is then projected over the 3-D MRI. The program developed to assess the proposed method to combine MRI and DITI resulted in a new tool for fusing two different image modalities, and it can help medical doctors.

Image fusion improvements applied at the generation of 3D thermal models

“…These thermographic images are acquired roughly at the same viewing of the "2D projections", i. e., at 0º, 90º, 180º and 270º. Originally, the small differences between the orthogonal and perspective representation were not considered [1,2]. However, further experiments proved that even such a small difference has an effect on the final 3D model.…”

“…This integration may provide a detailed analysis of the different structures and at the same time it supplies information about physiology [1,2].…”

“…The 3D THERMO [1,2] combines two different imaging modalities: 2D Infrared Images (IR) (skin temperature changes) with Magnetic Resonance Images (MRI) or Computer Tomography (CT) images, in order to obtain 3D thermal models. Regarding the 3D image visualization process, there are two different image viewing projections: orthogonal and perspective.…”

Framework for 2D-3D image fusion of infrared thermography with preoperative MRI

“…In the discussed neurosurgical application, an isosurface of the cerebral cortex has to be computed from preoperative MRI data. Brain segmentation algorithms (see [3]) fulfill this task by removing voxels not representing brain tissue. After successful brain segmentation, an isosurface of the cerebral cortex can be computed.…”

“…Image fusion requires the images to be aligned such that structures being visible in each appear at the same spatial position. This transformation is called image registration and requires establishing a coordinate transform [16] by feature matching [2,3], optimizing a similarity measure [12,15] or by calibration-based approaches [13]. The latter relies on external tracking systems, pre-calibrated instruments or manual measurements.…”