Magnetic Resonance Imaging (MRI) is an imaging technique using strength magnets, the interaction of high strength magnets and Radio Frequency transmissions with body tissues. MRI has been used for decades to largely evaluate the brain, spine, and musculoskeletal system and become standard modality in medical settings throughout the world as it provides anatomic and physiologic information noninvasively and without the use of ionizing radiation. MRI will allow to provide more detail, faster, with no damaging effects to patients. As an imaging modality that offers tissue differentiation without harm to patients, the imaging that magnetic resonance offers has rapidly developed into the physician’s modality of choice. MRI first performed on a human in 1977
Unlike nuclear medicine or CT imaging that use radioactivity or X-rays, MRI use high strength magnetic field. The largest part of an MRI unit is the superconducting magnet with 10,000g equals to 1 T. The MRI magnet is used to align the atoms and depends on properties of the nucleus. MRI scanners use the element hydrogen, with its single proton in the nucleus and abundance in all tissues of the body, to generate a strong signal. These protons spin, generating a magnetic field, with north and south poles on the axis of their spin. In the body, these protons are arranged in random directions, similar to iron atoms in a piece of soft iron.
Magnetic Resonance Imaging is widely used to detecting breast cancer include staging known breast cancer, monitoring the response to cancer treatment, checking if a breast cancer has come back after treatment, evaluating the breasts in a patient with cancer in the lymph nodes of the armpit who has a mammogram that does not show breast cancer, checking for rupture of breast implants, and screening for breast cancer in high-risk patients (those with BRCA-1 and BRCA-2 genes - genetic markers for an increased risk of breast cancer).
If a patient undergoes MRI (typically takes between 30 and 60 minutes to complete), the facility performing the examination should use, at a minimum, a dedicated breast coil, a high field magnet greater than 1 Tesla (a measure of strength of the MRI), offer high spatial and temporal resolution, and be able to subtract fat signal from the images.
MRI cannot be performed on certain people. For example, having a pacemaker, certain types of surgical clips, metal pins or plate. These issues aside, MRI of the breasts is now possible and there are many indications for such an examination. In the future, we will likely see an even greater role for MRI of the breasts that will hopefully enable us to provide even better healthcare and earlier detection of breast cancer. Magnetic Resonance Imaging (MRI) generally cost around £200 to £600.
