Magnetic Resonance Imaging of Soft Tissues
Soft tissue lesions are frequently encountered by radiologists in everyday clinical practice either for further diagnostic assessment of a known but nonspecific lesion, for pre-therapeutic evaluation, especially whenever surgery is considered, or as incidental findings. Characterization of soft tissue lesions remains problematic as many of these lesions have a nonspecific appearance and common radiologic methods such as radiography and computed tomography (CT) are characterized by poor soft tissue contrast. The application of magnetic resonance imaging (MRI) in the assessment of soft tissue lesions has markedly altered the treatment algorithms for a number of lesions [1,2]. In contrast to conventional radiography and CT, MRI provides excellent intrinsic soft tissue contrast, which is the main advantage over other tomographic techniques like CT. MRI uses a three-dimensional (3D) tomographic approach and is able to differentiate different tissue components. Contrast-enhanced imaging adds information on vascularity and dynamic contrast-enhanced imaging gives additional insight into vitality of a lesion and helps evaluating nonsurgical treatment approaches of soft tissue tumors . MRI has become an important tool in pre-operative planning, especially to define vital neurovascular structures. Although soft tissue lesion characterization and consequent definite diagnosis is not always possible due to the inherent nonspecificity of the modality, MRI is crucial in describing extent of lesion, involvement of neighboring tissues and vascularity . MRI findings should be interpreted in conjunction with clinical history, physical examination, laboratory results and potentially all other available imaging modalities to avoid misinterpretations [5,6].