5.0 Diagnostic X-ray EquipmentThe following rules are to ensure the safe use of human-use and veterinary-use diagnostic X-ray equipment at Virginia Tech. These rules are in conformity with the radiation safety standards recommended by the Commonwealth of Virginia. Show
Back To Top 5.1 Personnel MonitoringAll individuals working with diagnostic X-ray equipment shall wear a whole-body personnel monitoring device. Operators of fluoroscopic units shall wear a ring badge and a whole-body badge. When a lead apron or thyroid shield is worn, the whole-body monitoring device shall be worn at the collar outside the apron or shield. Declared pregnant radiation workers shall wear a second whole-body monitoring device under the lead apron at waist level. Back To Top 5.2 Patient ProtectionThe following rules are to protect patients from exposure to ionizing radiation, except that which is intended for diagnostic purposes.
Back To Top 5.3 Personnel ProtectionThe following rules are to protect operators, holders, and other people from exposure to ionizing radiation. 5.3.1 Stationary Units
5.3.2 Portable and Mobile Units
5.3.3 HoldersWhen a patient, animal, or film cassette must be provided with auxiliary support during an X-ray exposure:
Back To Top 5.5 Equipment RequirementsThe control panel shall contain the following legible and accessible warning statements:
The total filtration permanently mounted in the useful beam shall not be less than:
The tube housing assembly support shall ensure that the tube housing remains stable during the X-ray exposure. The technique factors to be used during an exposure shall be visible before the exposure begins. On battery-powered equipment, visual means shall be provided on the control panel to show the charge of the battery. A source-to-image distance (SID) indicator must be provided and be accurate to within 2% of the indicated SID. 5.5.1 Stationary, Portable, and Mobile UnitsA means for stepless adjustment (e.g. variable aperture collimator) of the size of the X-ray field shall be provided. Means shall be provided to visually define the perimeter of the X-ray field. The X-ray field shall not exceed the visually defined field by greater than 2%. A method shall be provided to show when the axis of the X-ray beam is perpendicular to the plane of the image receptor. The exposure shall be ended at a preset time interval, product of current and time, number of pulses, or radiation exposure to the image receptor. The X-ray control shall provide a visual indication of X-ray production and an audible signal when the exposure is finished. The X-ray control for stationary systems shall be permanently mounted in a protected area. 5.5.2 Fluoroscopic SystemsX-ray production shall be controlled by a dead-man switch. The on-time of the fluoroscopic tube shall be controlled by a timing device, which ends the exposure after 5 minutes. An audible signal shall signal the completion of the preset on-time. This signal will remain on until the timing device is reset. Protective barriers of at least 0.25 mm lead equivalency shall be used to attenuate scatter radiation from above the table top (e.g. drapes, bucky-slot covers). This shielding is in addition to the lead apron worn by personnel. Scattered radiation from under the table shall be attenuated by at least 0.25 mm lead equivalency. The fluoroscopic imaging assembly shall be provided with a primary protective barrier, which intercepts the entire cross section of the useful beam. The X-ray tube used for fluoroscopy shall not produce X-rays unless the barrier is in position to intercept the entire useful beam. Back To Top 5.6 Operator's BoothThe operator's booth shall have at least 7.5 square feet of unobstructed floor space in the booth. The booth may be of any shape with no dimension less than 2 feet. The booth is to be located or constructed so that the direct beam and unattenuated direct scatter radiation cannot reach the operator. 5.6.1 Structural RequirementsThe booth walls shall be at least 78 inches high and permanently fixed. A door or panel that is permanently part of the booth must be interlocked. Sufficient shielding shall be provided to prevent occupational limits from being exceeded. 5.6.2 Control PlacementThe X-ray control shall be fixed within the booth at least 40 inches from the edge of the booth wall closest to the examining table. The placement of the control shall allow the operator to use most of the viewing window. 5.6.3 Viewing requirementsThe booth must have a window that will allow the operator to view any occupant in the room and any entry into the room. Access doors that cannot be viewed by the operator must be interlocked. The window shall have an area of at least 1 square foot with the lower edge at least 4.5 feet from the floor. The edge of the window shall be at least 18 inches from the edge of the booth. The glass shall have the same lead equivalency as the walls of the booth. Back To Top 5.7 RecordsThe Laboratory Authority shall maintain the following records and information:
Back To Top 5.8 Surveys and InspectionsRadiation safety and equipment performance surveys shall be performed by a Qualified Expert annually on human-use units and at least every 3 years on bone densitometers or veterinary-use units. A survey for leakage radiation shall be performed following any maintenance, modification or relocation of the system. Radiation surveys of areas adjacent to the X-ray producing facility and in the booth will be performed after installation of new equipment or the relocation of a unit.
Reports of all surveys and inspections will be maintained in the Radiation Safety Office. Back To Top What parts of the body should be shielded from the useful beam whenever possible?Shielding, wherever possible is effective for protection of the patient's radio-sensitive organs, such as the breast, gonads, eyes and thyroid.
Which of the following are radiation shielding design considerations?Which of the following are radiation-shielding design considerations?. The mean energy of the x-rays that will strike the barrier.. Whether the barrier is of a primary or secondary nature.. The workload of the unit.. The use factor of the unit.. The occupancy factor behind the barrier.. What is used to protect the patient from scattering radiation?Lead aprons
It is used as thyroid collar shield, gonadal shield, apron and other forms to provide the secondary barriers to protect wearers from secondary or scatter radiation (see Fig. 2).
What are the safety precautions to be taken in radiography?Personnel must:. Avoid the primary X-ray beam.. Wear protective equipment (e.g., lead aprons and thyroid collar, leaded goggles, leaded gloves).. Use shielding (e.g., mobile shields, lead curtains), when possible.. Be aware of the position of the beam.. Know how to position themselves and the machine for the minimum dose.. |