Problems in texture analysis with magnetic resonance imaging

Since its introduction in the 1930s, magnetic resonance imaging (MRI) has become recognized as a powerful in vivo diagnostic tool. The objective of this article is to discuss developments in quantitative MRI - and particularly texture analysis - that maximize diagnostic information, A fundamental part of the work involves careful study of the optimal MRI data collection strategies for texture analysis. This is critical, because different centers may vary their measuring sequences and acquisition protocols for clinical reasons, and may be reluctant to vary these for texture investigation. Different measuring techniques, such as spin echo, gradient echo, and echo planar, and different measuring parameters produce totally different patterns in texture. Careful investigation of the dependence of all these variables using texture phantoms (test objects) will help understand how MRI image texture is formed from tissue structures. Therefore, it is essential to design and test reliable and accurate test objects for a detailed assessment of texture analysis methods in MRI, The main feature of these test objects is their ability to simulate tissue-like textures with tissue-like MR relaxation properties. Long-term stability is also vital, as is uniformity of the overall texture. Another aspect is to examine the test objects under a whole range of MRI measuring sequences and imaging conditions using different scanners to determine their stability and utility.