What is the meaning of the nature of the equipment in the information table of the allocation and use of large medical equipment of category B?

Large medical equipment classification --------- ----- Category A: 1. X-ray positron emission tomography (PET-CT, including positron emission tomography that is PET). 2. gamma-ray stereotactic therapy systems (γ-knife). 3. medical electron cyclotron acceleration therapy system (MM50). 4. proton therapy system. 4. proton therapy system. 5. 5. other large-scale medical equipment with a unit price of 5 million yuan or more. ---------- Category B: 1. X-ray computed tomography (CT). 2. 2 medical magnetic **** vibration imaging equipment (MRI). 3 digital subtraction angiography. 3 digital subtraction angiography X-ray machine (DSA). 4. 4. medical electronic linear gas pedal (LA). 5. 5. single photon emission computed tomography (SPECT). ---------- ---- LA = Linear Accelerator = Medical Linear Accelerator (used for radiation therapy of tumors) Ultrasound is not a Class B large medical device.