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.
Breast cancer screening
Despite the aids provided from MRIs, there are some disadvantages. For example, although it is 27–36% more sensitive, it has been claimed to be less specific than mammography. As a result, MRI studies may have up to 30% more false positives, which may have undesirable financial and psychological costs on the patient. Also, MRI procedures are expensive and include an intravenous injection of a gadolinium contrast, which has been implicated in a rare reaction called nephrogenic systemic fibrosis (NFS). Although NSF is uncommon, other patients with a history of renal failure/disease would not be able to undergo an MRI scan. Breast MRI is not recommended for screening all breast cancer patients, yet limited to patients with high risk of developing breast cancer that may have high familial risk or mutations in BCRA1/2 genes. Breast MRI is not a perfect tool despite its increased sensitivity for detecting breast cancer masses when compared to mammography. This due to the ability of MRIs to miss some cancers that would have been detected with conventional mammography, as a result, MRI screening for breast cancer is most affective as a combination with other tests and for certain breast cancer patients. In contrast, the use of MRIs are often limiting to patients with any body metal integration such as patients with tattoos, pacemakers, tissue expanders, and so on.