Advantages Of Nuclear Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) or Nuclear magnetic resonance imaging (NMR) is a non-ionizing imaging modality used for clinical imaging over the past 25-30 years. This imaging modality provides excellent soft tissue imaging with good contrast resolution in different parts of the body like brain, muscles etc compared to other ionizing modalities like CT (Computed tomography) and conventional radiography. The most important advantage of MRI compared to other imaging modalities is the fact it uses strong magnetic field strengths for imaging unlike other modalities which use ionizing radiation like x-rays for imaging. The principle of MRI lies in using strong magnetic fields to excite certain atoms within the body and then using radiofrequency

This high contrast resolution is very useful in brain imaging. In spite of these advantages MR also has its own limitations as it provides the user with gross macroscopic details but for abnormalities are only visible when it reaches the anatomical scale. This limitation of MRI has led to the widespread use of diffusion weighted imaging and diffusion tensor

MRI is one of the safest and easiest of all imaging methods to noninvasively image the entire brain in-vivo. Conventional MRI cannot image the complex axonal structure organization of the brain which is very well demonstrated by tensor imaging (DTI) which was introduced in the mid 1990’s (P J Basser et al., 1994) and followed by many experimental animal studies and now used very routinely in clinical practice (Harsan et al., 2006). Applications on DTI are very large and extensive. The main ones are as follows: DTI detects high diffusion anisotropy which is seen in unmyelinated nerves (Beaulieu & Allen, 1994). DTI is also very useful in detecting anisotropy changes during brain development without surgery (J. Zhang et al., 2003) (Mukherjee et al., 2002). DTI has proved to be useful in pathology detection of premyelinated brain (J. Zhang et al., 2003) . The use of high resolution diffusion tensor imaging has been used in Phenotype characterization of white matter tracts proved by animal studies (Nieman, Flenniken, Adamson, Henkelman, & Sled, 2006). DTI is also useful in white matter parcellation and connectivity studies (Pagani, Filippi, Rocca, & Horsfield,