Medical imaging
Because CT and MRI are sensitive to different tissue properties, the appearances of the images obtained with the two techniques differ markedly. In CT, X-rays must be blocked by some form of dense tissue to create an image, so the image quality when looking at soft tissues will be poor. In MRI, while any nucleus with a net nuclear spin can be used, the proton of the hydrogen atom remains the most widely used, especially in the clinical setting, because it is so ubiquitous and returns a large signal. This nucleus, present in water molecules, allows the excellent soft-tissue contrast achievable with MRI.
Soft tissue sarcoma in cats and dogs
Prior to initiating any type of treatment, it is important to gather as much information as possible regarding the tumor's tissue origin, size, site, histologic grade (level of aggressiveness) and whether it has spread to other organs.
To definitively confirm the diagnosis of a soft-tissue sarcoma, the veterinarian will have to perform biopsy for histopathologic evaluation. Additional tests are performed in order to evaluate how advanced the cancer is. These tests generally involve blood and serum biochemical tests, chest X-rays to check for metastasis to the lungs and imaging studies [e.g. ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI)] to evaluate the extent of the disease.