According to the NCRP, the minimum total filtration for fluoroscopic equipment operating above 70 kVp must be:

The established guideline from the National Council on Radiation Protection and Measurements (NCRP) indicates that fluoroscopic equipment operating above 70 kVp must have a minimum total filtration of 2.5 millimeters aluminum equivalent. This requirement is crucial for ensuring patient safety and reducing unnecessary radiation exposure.

Filtration in radiography serves to absorb low-energy x-rays that do not contribute to diagnostic imaging but instead increase the patient's exposure to radiation. By having a minimum filtration standard, it ensures that only those x-rays that contribute meaningfully to the image quality penetrate through to the patient, thereby enhancing the overall diagnostic effectiveness while minimizing radiation dose.

While lower levels of filtration might still be acceptable for certain applications or equipment, the specific requirement of 2.5 millimeters aluminum equivalent for fluoroscopy operating above 70 kVp reflects a commitment to maintain safety standards in medical imaging. It balances the need for effective imaging with the imperative of radiation protection, showcasing how regulatory organizations work to safeguard both patient and staff health in clinical settings.