Compared with ordinary molybdenum target X-ray, CT has higher density resolution, can obtain the cross-sectional image of the scanned part, clearly display the anatomical structure of each layer of the breast, and has higher display rate for cysts, bleeding and calcification in the breast, especially for dense breast, CT examination can provide more information than ordinary molybdenum target X-ray. It is reported that CT is superior to X-ray photography in finding tiny lesions, and lesions with a size of 0.2cm can be found. However, some people think that the spatial resolution of CT is not as good as that of ordinary X-ray photography.
The CT manifestations of common breast diseases are as follows: inflammatory lesions are often slightly increased in density without obvious edges; Benign masses are usually round or oval, with uniform density and smooth or lobulated edges. The CT value of fibroadenoma is close to that of pectoral muscle, while the CT value of cyst is liquid. Malignant tumors are usually irregular high-density tumors with uneven density, and the surrounding burrs are clearly displayed, and the display rate of fine calcification of breast is high.
In addition, CT scan is more valuable for diagnosis when used in the following situations, such as tumor lesions in dense glands, breast root lesions and lymph node metastasis of internal breast, armpit and mediastinum. Breast cancer lesions have been enhanced after injection of contrast agent, but the degree of enhancement varies with the type of lesions. Therefore, CT scanning is not necessarily the best means to distinguish benign from malignant breast lesions.
Because CT examination is expensive and requires intravenous injection of contrast agent, the radiation dose is much higher than that of ordinary molybdenum target X-ray film, so it is generally not used as a routine examination method for breast lesions, but only as a supplement to other methods. In some special cases, such as observing whether breast cancer has lung metastasis, it has high diagnostic value.