Dual energy computed tomography techniques applied to the characterization of cartilage tissue

The study and visualization of articular cartilage are of great interest for different pathological conditions. Currently, 3D tomographic methods considered for the study of cartilage tissue are Magnetic Resonance Imaging (MRI), which is considered the gold standard technique, and Computed Tomography (CT). However, these have various limitations. MRI is characterized by long acquisition times and difficulties in the presence of metal implants and in the visualization of bones; while CT has difficulties in differentiating soft tissues, characterized by lower attenuation of X-rays. Therefore, in this thesis work, we want to study the properties of Dual Energy Computed Tomography (DECT), which with a single acquisition provides multiple material-specific information using virtual monochromatic and material density reconstructions. In particular, we want to study if DECT without the use of contrast agents, allows a satisfactory visualization of cartilage. Subsequently, we want to investigate how the combined use of DECT and a new cationic contrast agent, called CA4+, can further increase the quality of images. For this purpose, three bovine tibiae supplied by the food chain were considered for a pre-clinical testing. Initially, acquisitions without the use of contrast medium were performed. Afterward, the tibiae were immersed in the contrast medium at three different concentrations (one for each tibia considered). It has been observed that DECT without contrast medium does not allow satisfactory visualization of cartilage, even exploiting the properties of material density and virtual monochromatic reconstructions. On the other hand, the presence of CA4+ contrast medium allows a direct visualization of cartilage and improved distinction with surrounding tissues by exploiting monochromatic and material density reconstructions.