《Breast MRI》.ppt

Breast - MRI MRI is a powerful tool: it is able to detect cancer not visible on conventional imaging, it can be used as a problem-solving instrument, and it can be applied to screen high-risk patients. Breast MRI is also better at monitoring the response to chemotherapy than other imaging modalities used today.It can change the treatment plan in 15-30% of patients with breast cancer. Introduction Enhancing lesions are divided into three main categories: focus/foci, masses, and areas of non-mass enhancement Focus (or when multiple, foci) is an area of enhancement measuring less than 5 mm in diameter which is too small to characterize.  A mass is a three-dimensional lesion that occupies a space within the breast. Just as in mammography and ultrasound, we look at its shape, its margins and its internal characteristics: this includes its T1- and T2-characteristics as well its enhancement pattern. Non-masslike enhancement are areas of enhancement without a detectable three-dimensional mass. Features of non-mass enhancement include its distribution, its internal enhancement pattern, and whether the enhancement is symmetric or asymmetric. Focus and foci One of the things we run into are little bright objects.These foci are enhancing areas of less than 5mm in diameter and are too small to characterize. They have persistent type 1 curves. These lesions are typically stable on follow-up and are considered to be a part of the normal background enhancement pattern in the breast. Masses Morphology ShapeA mass can be round, oval, lobulated, or irregular. Lobulated masses have undulating contours. Irregular masses have an uneven shape that cannot be characterized as round, oval, or lobulated. If a mass is irregularly shaped, it has a 32% chance of being malignant. The image on the left shows a large, irregular mass, which proved to be an angiosarcoma. MarginMargins can be described as smooth, irregular, or spiculated .Spiculated margins are frequently a featu