Renal cell carcinoma
Magnetic Resonance Imaging (MRI) scans provide an image of the soft tissues in the body using radio waves and strong magnets. MRI can be used instead of CT if the patient exhibits an allergy to the contrast media administered for the test. Sometimes prior to the MRI scan, an intravenous injection of a contrasting material called gadolinium is given to allow for a more detailed image. Patients on dialysis or those who have renal insufficiency should avoid this contrasting material as it may induce a rare, yet severe, side effect known as nephrogenic systemic fibrosis. A bone scan or brain imaging is not routinely performed unless signs or symptoms suggest potential metastatic involvement of these areas.
MRI scans should also be considered to evaluate tumour extension which has grown in major blood vessels, including the vena cava, in the abdomen. MRI can be used to observe the possible spread of cancer to the brain or spinal cord should the patient present symptoms that suggest this might be the case.
Lameness (equine)
The bone scan offers several advantages over traditional radiographs. In some cases, it may be more sensitive due to the fact that some lesions are only apparent on radiographs after they have become chronic. The bone scan allows imaging of the pelvis, vertebral column, and upper limbs, which are areas that are usually poorly imaged by radiographs on the adult horse, due to their size. It also allows some evaluation of soft tissue, which is generally not imaged well by radiographs.