Veterinary X-ray Systems

(A) Equipment. (1) Technique and Exposure Indicators. (a) The technique factors to be used during an exposure shall be indicated before the exposure begins. If automatic exposure controls are used, the technique factors which are set prior to the exposure shall be indicated. (b) The requirements of 105 CMR 120.408(A)(1) may be met by permanent markings on equipment having fixed technique factors. Indication of technique factors shall be visible from the operator's position except in the case of spot films made by the fluoroscopist. (c) The x-ray control shall provide visual indication of the production of x-rays observable at or from the operator's protected position whenever x-rays are produced. (2) The leakage radiation from the diagnostic source assembly measured at a distance of one meter in any direction from the source shall not exceed 100 milliroentgen in one hour when the x-ray tube is operated at its leakage technique factors. Measurement is averaged over an area of 100 square centimeters with no linear dimension greater than 20 centimeters. (3) The useful beam shall be restricted to the area of clinical interest and no larger than the size of the image receptor. (4) Collimating devices shall be provided and shall limit the beam to the area of the image receptor to within 2% of the SID, and shall provide the same degree of protection as is required of the housing. (5) The half-value layer of the useful beam shall not be less than 0.5 millimeters aluminum equivalent for machines operating up to 50 kVp, 1.5 millimeters and 70 kVp, and two millimeters aluminum equivalent for machines operating above 70 kVp. (6) A device shall be provided to terminate the exposure after a preset time or Exposure. (7) A dead-man type of exposure switch shall be provided, together with an exposure cord of sufficient length, so that the operator can stand out of the useful beam and at least six feet from the animal during all x-ray exposures. (8) The coefficient of variation of Exposure shall not exceed 0.10 when all technique factors are held constant. This requirement shall be deemed to have been met if, when four Exposures are made at identical technique factors, the value of the average Exposure (E) is max greater than or equal to five times the maximum Exposure (E ) minus the minimum min Exposure (E ): max min E $ 5 (E - E ) (9) The primary beam shall be aligned with the film by using specified techniques in the facility's operating procedures. (10) Fluoroscopic, CT, and therapy systems used in veterinary facilities shall meet the requirements of 105 CMR 120.405, 120.409 and 120.410 respectively, except the aural communications of 105 CMR 120.400, 120.422: Appendix C, 120.409(B)(1) and 120.410(B)(1). (11) Portable machines shall be used in a manner which complies with 105 CMR 120.000. (B) Structural Shielding. All wall, ceiling, and floor areas shall be equivalent to or provided with applicable protective barriers to assure compliance with 105 CMR 120.211, 120.221 and 120.222. (C) Additional Operational Controls for Veterinary Facilities. (1) All exams and retakes shall be ordered by the veterinarian. (2) The x-ray tube shall not be held by any individual during radiographic exposures. (3) Unless required to restrain an animal, the operator shall stand at least six feet away from the useful beam and the animal during radiographic exposures. (4) No individual, other than the operator, shall be in the x-ray room or area while exposures are being made unless such individual's assistance is required. (5) When an animal must be held in position during radiography, mechanical supporting or restraining devices shall be used when technique permits. (6) A pregnant female shall not hold or restrain an animal.