What is ndma?

Ndma is the abbreviation of National Digital Mammography Archives. National Digital Mammography Archives.

Basic knowledge: Soft X-rays are used for projection and imaging of breast tissue. In the past, molybdenum target film was commonly used for direct imaging, but now it is rarely used. Now, due to the rapid development of digital imaging technology, basically the film development after digital imaging, the image quality has made a qualitative leap and added many new functions. The breast film formed by it has high definition, which is incomparable to the previous molybdenum target film, and breast nodules with a diameter of 0.2 cm can be found.

Mammography is different from ordinary mammography. In general X-ray machine, the anode palladium surface of the bulb tube is tungsten, and the wavelength generated is 0.008-0.03 1 nm, which is a hard ray with short wavelength and strong penetration.

The wavelengths of molybdenum, rhodium and palladium are 0.063-0.07 1 nm, which are long and have weak penetration. It is a kind of soft ray with high resolution to the fine density difference of soft tissue, which can obtain a good breast image and clearly show glands, ducts, fibrous septa, skin, subcutaneous tissue, vascular structure, pathological masses, fine calcification and so on.

Generally take a standing posture. Axial (CC) and oblique (MLO) projection directions are commonly used, so it is usually taken four times. The film will be marked with the following letters: L (left chest), R (right chest), CC (axial position) and MLO (lateral position).