4D space-time techniques: a medical imaging case study

We present the problem of visualizing time-varying medical data. Two medical imaging modalities are compared-MRI and dynamic SPECT. For each modality, we examine several derived scalar and vector quantities such as the change in intensity over time, the spatial gradient, and the change of the gradient over time. We compare several methods for presenting the data, including isosurfaces, direct volume rendering, and vector visualization using glyphs. These techniques may provide more information and context than methods currently used in practice; thus it is easier to discover temporal changes and abnormalities in a data set.

1. Introduction

Time-varying data is common in medicine. Physicians frequently follow progression of disease and make treatment decisions based on periodic scans of a patient. For example, multiple sclerosis (MS) is a degenerative disease characterized by scar tissue that appears as bright lesions in spin-spin (T2) and proton density (PD) Magnetic Resonance Imaging (MRI) brain scans. Thus, physicians use sequences of MRI images to diagnose MS and track disease progression over several months or years.