DHS 157.75(7)(7)Mechanical support of tube head. The tube housing assembly supports shall be adjusted such that the tube housing assembly will remain stable during an exposure unless tube-housing movement is a designed function of an x-ray system.
DHS 157.75(8)(8)Technique indicators.
DHS 157.75(8)(a)(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.
DHS 157.75(8)(b)(b) The requirement in par. (a) 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.
DHS 157.75(9)(9)Maintaining compliance. Diagnostic x-ray systems and their associated components used on humans and certified under the federal x-ray equipment performance standard, 21 CFR 1020, shall be maintained in compliance with applicable requirements of that standard.
DHS 157.75(10)(10)Locks. All position locking, holding and centering devices on x-ray system components and systems shall function as intended.
DHS 157.75 HistoryHistory: CR 01-108: cr. Register July 2002 No. 559, eff. 8-1-02; CR 06-021: am. Table Register October 2006 No. 610, eff. 11-1-06; CR 22-015: am. Table Register June 2023 No. 810, eff. 7-1-23.
DHS 157.76DHS 157.76Fluoroscopic equipment. Only image-intensified or direct-digital receptor fluoroscopic equipment shall be used for fluoroscopy. Equipment for fluoroscopic imaging or for recording images from the fluoroscopic image receptor, except computed tomography x-ray systems manufactured on or after November 29, 1984, shall meet all the following requirements:
DHS 157.76(1)(1)Limitation of useful beam.
DHS 157.76(1)(a)(a) The fluoroscopic imaging assembly shall be provided with a primary protective barrier which intercepts the entire cross section of the useful beam at any source to image distance. The x-ray tube used for fluoroscopy shall not produce x-rays unless the barrier is in position to intercept the entire useful beam. The air kerma rate due to transmission through the barrier with the attenuation block in the useful beam combined with radiation from the fluoroscopic image receptor shall not exceed 3.34 x 10-3 percent of the entrance air kerma rate, at a distance of 10 cm from any accessible surface of the fluoroscopic imaging assembly beyond the plane of the image receptor.
DHS 157.76(1)(b)(b) Compliance shall be determined as follows:
DHS 157.76(1)(b)1.1. The air kerma rate shall be measured as required under sub. (4). The air kerma rate due to transmission through the primary barrier combined with radiation from the fluoroscopic image receptor shall be determined by measurements averaged over an area of 100 square cm with no linear dimension greater than 20 cm.
DHS 157.76(1)(b)2.2. If the source is below the tabletop, the measurement shall be made with the input surface of the fluoroscopic imaging assembly positioned 30 cm above the tabletop. If the source is above the tabletop and the source to image distance is variable, the measurement shall be made with the end of the beam-limiting device or spacer as close to the tabletop as it can be placed, provided that it shall not be closer than 30 cm.
DHS 157.76(1)(b)3.3. Movable grids and compression devices shall be removed from the useful beam during the measurement.
DHS 157.76(1)(b)4.4. For all measurements, the attenuation block shall be positioned in the useful beam 10 cm from the point of measurement of entrance air kerma rate and between this point and the input surface of the fluoroscopic imaging assembly.
DHS 157.76(1)(c)(c) Radiation therapy simulation systems shall be exempt from this requirement provided the systems are intended only for remote control operation and the manufacturer sets forth instructions for assemblers with respect to control location as part of the information required in 21 CFR 1020.30 (g).
DHS 157.76(2)(2)Field limitation.
DHS 157.76(2)(a)(a) For fluoroscopic equipment manufactured after February 25, 1978, when the angle between the image receptor and the beam axis of the x-ray beam is variable, means shall be provided to indicate when the axis of the x-ray beam is perpendicular to the plane of the image receptor. Compliance with par. (e) 1. and 2. shall be determined with the beam axis indicated to be perpendicular to the plane of the image receptor.
DHS 157.76(2)(b)(b) Means shall be provided to permit further limitation of the x-ray field to sizes smaller than the limits of par. (e) 1. and 2. Beam limiting devices manufactured after May 22, 1979, and incorporated in equipment with a variable source to image distance, the capability of a visible area of greater than 300 square cm, or both, shall be provided with means for stepless adjustment of the x-ray field. Equipment with a fixed source to image distance and the capability of a visible area of no greater than 300 square cm shall be provided with either stepless adjustment of the x-ray field or with a means to further limit the x-ray field size at the plane of the image receptor to 125 square cm or less. Stepless adjustment shall, at the greatest source to image distance, provide continuous field sizes from the maximum obtainable to a field size containable in a square of 5 cm by 5 cm. This paragraph does not apply to intensified fluoroscopy units without image intensification.
DHS 157.76(2)(c)(c) The x-ray field produced by non-image-intensified fluoroscopic equipment shall not extend beyond the entire visible area of the image receptor. Means shall be provided for stepless adjustment of field size. The minimum field size, at the greatest source to image distance, shall be containable in a square of 5 cm by 5 cm.
DHS 157.76(2)(d)(d) For fluoroscopic equipment with inherently circular image receptors manufactured before June 10, 2006, other than radiation therapy simulation systems, all the following applies:
DHS 157.76(2)(d)1.1. Neither the length nor the width of the x-ray field in the plane of the image receptor shall exceed that of the visible area of the image receptor by more than 3% of the source to image distance. The sum of the excess length and the excess width shall be no greater than 4% of the source to image distance.
DHS 157.76(2)(d)2.2. For rectangular x-ray fields used with circular image receptors, the error in alignment shall be determined along the length and width dimensions of the x-ray field which pass through the center of the visible area of the image receptor.
DHS 157.76(2)(e)(e) For fluoroscopic equipment manufactured on or after June 10, 2006, other than radiation therapy simulation systems, the maximum area of the x-ray field in the plane of the image receptor shall conform to one of the following requirements:
DHS 157.76(2)(e)1.1. When any linear dimension of the visible area of the image receptor measured through the center of the visible area is less than or equal to 34 cm in any direction, at least 80% of the area of the x-ray field overlaps the visible area of the image receptor.
DHS 157.76(2)(e)2.2. When any linear dimension of the visible area of the image receptor measured through the center of the visible area is greater than 34 cm in any direction, the x-ray field measured along the direction of greatest misalignment with the visible area of the image receptor does not extend beyond the edge of the visible area of the image receptor by more than 2 cm.
DHS 157.76(2)(f)(f) For x-ray systems with inherently rectangular image receptors manufactured on or after June 10, 2006, all the following applies:
DHS 157.76(2)(f)1.1. Neither the length nor the width of the x-ray field in the plane of the image receptor shall exceed that of the visible area of the image receptor by more than 3% of the source to image distance. The sum of the excess length and the excess width shall be no greater than 4% of the source to image distance.
DHS 157.76(2)(f)2.2. The error in alignment shall be determined along the length and width dimensions of the x-ray field which pass through the center of the visible area of the image receptor.