Abstract: Currently there are about 120 million women worldwide each year diagnosed with breast cancer, and there are 50 million women die of breast cancer. Therefore early diagnosis of breast cancer is very important. Then, how the breast MRI is the imaging. And what is the application of MRI in the diagnosis of breast cancer. Further more, I will talk about what are the advantages of MRI breast imaging compared with conventional imaging methods? Also , the limitations of breast MRI examin ation are important to be concerned about.
Last, I will talk about what remains to be done in the MRI diagnosis of breast cancer. Key words: MRI, breast cancer, early diagnosis, advantage, limitation Breast cancer is one of the most common malignanc y of women, which usually occurs in breast epithelial tissue, and it is one of the most common malignant tumor that seriously affects women’s physical and mental health and even it is life -threatening. According to statistics, the incidence rate is 7 to 10 percent of various malignant tumors of whole body. It’s often associated with genetic disease.
And the women who are 40 to 60 years old, and are post-menopausal have a higher prevalence. Only about 1-2% of breast patients were male. The information above indicates the significance of breast cancer for early diagnosis. Early diagnosis of breast cancer is very important. Currently there are about 120 million women worldwide each year diagnosed with breast cancer, and there are 50 million women die of breast cancer. Therefore, how to effectively control the occurrence and development of breast cancer has become imperative.
Most scholars believe that during the prevention and treatment of cancer, the secondary prevention of cancer, that is immediate-early investigation, early diagnosis and treatment will be the efficacy direction to obtain substantial increase in solid tumors for a long time in the future. For breast cancer, early detection is the key to improve the prognosis and improve the survival rate. Therefore, improving the accuracy of early diagnosis of breast cancer can greatly reduce the appearance of advanced breast cancer and reduce mortality, so early diagnosis of breast cancer is of great significance.
In recent years, breast conserving surgery and postoperativeradiation therapy combination therapy has become the main treatment of early breast cancer in the United States and Europe. Many studies indicate after breast conserving surgery ,the patients have 90 percent of living more 10 years. Current ly, the clinical mostly use physical examination, mammography and ultrasound to evaluate and select breast conserving surgery, but there are some subjective in physical examination, and the test results depend heavily on the examiner’s clinical experience.
The mammography and ultrasound have lower sensitivity , so the preoperative evaluation of the results is unsatisfactory. MRI (Magnetic Resonance Imaging) with good soft tissue resolution and no radiation damage, has high sensitivity for the discovery and exclusion of breast lesions , and can clearly show the normal breast anatomy and fine structure of lesions, so it can provide the information that mammography and ultrasound can not provide.
Routine examination shows that, for breast cancer patients, preoperative MRI examination can can detect additional malignant lesions, thus changing the treatment of breast cancer. MRI can more accurately evaluate the extent of the tumor, and play the complementary role when the conventional imaging underestimated orov erestimated tumor extent. You may want to ask what is MRI, the following is some definition for MRI. MRI, also known as magnetic resonance imaging uses nuclear magnetic resonance theory, to detecte the emitted electromagnetic waves by external gradient magnetic field, whereby the image of the internal structure of objects can be drawn.
Therefore MRI obtain a wide range of applications in physical, chemical, medical, petrochemical, archeology and so on. Then, how the breast MRI is the imaging. Breast MRI is a imaging technology which uses magnetic field and radio waves to form a detailed three-dimensional imaging of breast tissue. Before the examination, you may need intravenous injection of contrast agent through the arm. Because the contrast agent may affect the kidney, doctors may check your kidney before the injection of contrast agent. Contrast agent will make any suspected breast cancer organization to be more clearly displayed.
During the injection of contrast agent, some people may experience temporary discomfort. The growth of umor needs much blood supply. In breast MRI, the contrast agent is more concentrated in growing part of tumor, thus leaving a white area in black background. This feature will help radiologists determine which areas of tumor growth is possibly a imaging part of the tumor. After the breast MRI examination, you may need further examination to confirm whether those suspicious site is indeed tumor tissue or not.
Many scholars have tried to use MRI’s good soft tissue resolution cap abilities to detect and identify a variety of breast lesions, but until the clinical application of paramagnetic contrast agent, through strengthening to show lesions and further observations of pathological characteristics of lesions, MRI’s application in the breast cancer obtained a great progress. In recent years, the advances in surface coil technology and imaging sequence, making the MRI image’s spatial resolution and time resolution be greatly improved.
MRI examination can not only get the subtle morp hological characteristics of breast lesions, but also can use multi -phase dynamic contrast-enhanced scans to obtain lesions enhanced dynamic information. At home and abroad the vast majority of studies on breast MRI use high magnetic field (1. 5T or above) MR system , mainly due to the follwing reasons. Firstly, high -field MR system will inevitably produce a high signal to noise ratio, so the image quality is better than the low field MR . Secondly, high -field MRI system is better than low field.
MR in low-fat-suppression field, because the breast is rich in fat tissue , good fat suppression effect is good for clearly show the lesions. Thirdly, in high -field MRI, the larger the signal’s strength difference between the strengthened organization and the non-strengthened organization is, the better the contrast between the two will be. In recent years, open low-field MRI’s applications increases day by day.
But because of the low field MR’s signal to noise ratio is low, and fat -suppression is not as effective as high-field MR, we now mainly use it for biopsy and treatment. In recent years, because of the applications of specially dedicated breast coil , breast MRI imaging has been significantly improved. Given the reasons above, many researchers believe that high field strength and a special breast coil is the essential hardware to ensure the quality of breast MR imaging . With the continuous development of dedicated breast coil and the advent of fast imaging sequences, MRI , particularly enhanced MRI, has become the most promising breast cancer diagnosis.
The combination of MRI and diffusion-weighted imaging (DWI) further improves the detection rate of breast cancer. MRI is currently thought to be one of the most valuable means of checking out the b reast cancer multifocal lesions and multi-center lesions. In addition to its high resolution and high detection rate, its no radiation, and can be repeatedly continuous operated without harm, is also a major advantage as a means of breast cancer screening. What are the advantages of MRI breast imaging , compared with conventional imaging methods?
Firstly, there is no radiation damage in magnetic resonance imaging compared with X-ray, so it is good for patients. Secondly, with a g ood soft tissue resolution, MRI can well indicate the glandular structure. Especially for the dense breast which is difficult to detect by X-ray, MRI is much better for the detection of lesions. Thirdly, the choice of a variety of imaging sequences and multi-dimensional imaging observations, can provide many aspects of the feature information such as the internal structure of lesions, morphology, distribution methods and so on.
Fourthly, the hemodynamic characteristics of lesions can be obtained by MRI dynamic contrast -enhanced scans, thus providing an important basis for the qualitative diagnosis and treatment evaluation. In addition, functional imaging methods such as diffusion-weighted imaging and magnetic resonance spectroscopy, can also obtain the movement of water molecules an d information of the metabolites, which can not be obtained by the traditional imaging methods. Also, there are some limitations of breast MRI examination. Firstly, the check cost is very high.
This is regarded as the greatest limitations of breast MRI examination, making it difficult to be widely implemented even with the best clinical results. Secondly, benign and malignant lesions in the MRI showed a certain degree of overlap, so the MRI findings of atypical lesions should be further pathological examination. Thirdly, MRI for small needle-like calcification is not sensitive, especially when the number of calcification is small, for example only 3 to 5, it should still be combined with X-ray mammography for diagnosis.
Fourthly, sometimes the image is affected by respiratory artifacts. Finaly, those peple who have MRI contraindications of can not be checked with this method. What I will further talk about is what remains to be done in MRI breast. Providing the limitations of breast MRI examination, what rema ins to be done in MRI breast is to cut down the cost of breast MRI examination, which needs a wide application of breast MRI examination.
Besides, the accuracy of breast MRI examination also needs to be further increased, whith will lead to a better results of breast examination and will helps patients better. From above we can conclude that MRI breast imaging plays a very important part in the diagnosis of breast cancer. It not only improves the diagnosis method of breast cancer , but alse helps many breast cancer patients live longer. However, there are still many things wo must do to improve the MRI breast imaging. Therefore, we must study harder in the future to do better in the breast MRI examination.