Magnetic resonance imaging has emerged as one of the most valuable tools in the field of breast imaging and asymptomatic diagnosis (check-up). Scientific research has shown its superiority over mammography and ultrasound, but we should focus on which women it is suitable for and when it really benefits a patient. First of all, it is useful to know that MRI is an examination with a high sensitivity rate (90-95%).
The MRI scanners must have special coils and have particularly strong magnetic fields (> 1.5 tesla). MRI is performed on women of reproductive age between the 7th and 13th day of their menstruation cycle in a supine position with one breast free. It takes around 30 minutes and is almost always accompanied by an infusion of an intravenous paramagnetic material so that any suspicious findings and formations (if any) can be detected and studied in the best possible way.
The women who most benefit from an MRI fall into one or more of the following categories:
- Women in high-risk groups with a greater than 20% chance of developing cancer in their life.
- Women with silicone implants
- Women who have undergone mammography and ultrasound, but the imaging has not yielded the desired results (e.g. women with particularly dense breast tissue and women of reproductive age).
- Women with persistent nipple discharge without it being accompanied by other imaging findings.
- Cases of preoperative staging in women with lobular breast cancer.
- Women with lymph node metastasis, when the primary focus of the disease is unknown.
- Cases of disease re-examination and monitoring (pre-operative chemotherapy or post-operative monitoring).
It is worth noting that the MRI method outperforms the combination of mammography and ultrasound by 10-15%. It is particularly indicated in cases of very small and non-palpable tumors (<1 cm), while at the same time it ensures by 93% that the armpit lymph nodes will be clean. Moreover, according to newer research, MRI contributes to the diagnosis of cancers that until now escaped mammography (interval cancers), thus ensuring early diagnosis and successful treatment.
However, the main disadvantage of MRI is its low specificity (ie it sometimes presents false positive findings) and the fact that it does not depict microcalcifications, which are common findings in mammograms, while it has limited utility in inflammatory cancer and DCIS (in carcinoma in situ). Also, there are some cases in which MRI is not indicated such as: in case of an allergy to the paramagnetic material, when the patient presents symptoms of claustrophobia (this can be overcome by the administration of anxiolytics/sedatives by an anesthetist), when there are metal objects such as a pacemaker, old hip prostheses, old artificial heart valves, cochlear implants and vascular stents.
To sum up, MRI has offered great possibilities for physicians and correspondingly great benefits for patients. It took the early diagnosis of breast cancer a step further and benefited large groups of the general population who for various reasons could not benefit from the use of mammography.