The effect of the x-ray radiation for the organism Bionegatív effect

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Mabel Heath
5 years ago
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1 Radiation safety During each laboratory or diagnostic procedure, safety should be a primary objective. Radiography is no different. The veterinarian must establish and maintain a radiation safety program for the protection of the patient, the client, and the technical staff. Hazards of ionizing radiation All living cells are susceptible to ionizing radiation damage. Rapidly dividing cells are the most sensitive. Other tissues that are readily sensitive include bone, lymphatic, dermis, leukopoetic and hemopoetic,, and epithelial tissues. The ionizing radiation has a cumulative effect. Hazards of ionizing radiation Somatic damage - cancer, cataracts, aplastic anemia, and sterility - Mortality: a single exposure to a dose of 3 Gray is lethal. Genetic damage - mutation The effect of the x-ray radiation for the organism Bionegatív effect Radiation dosage Sources of exposure dose from ionizing radiation Radiation doses received from some familiar activities Internal 11% Terrestrial 8 % Medical x-rays 11% Cosmic 8 % Nuclear medicine 4% Consumer products 3% Other 1 % 82 % 18 % Radon 55% Los Angeles Paris flight Thoracic radiograph Apollo X. moon flight Panorama dental x-ray Mammography Colonography Heart angiography Radiation therapy 0.05 msv 0.22 msv 4.8 msv 9.1 msv 15 msv 80 msv 450 msv msv 1

MPD: 0,05 Sv/year (whole body) Background radiation: 0,0036 Sv/year Avarage praxis: 0,0004-0,0008 0,0008 Sv/year Radiation protection in the veterinary practice Radiation doses received by the

2 Maximum Permissible Dose The maximum dose of radiation that a person may receive in a given period. National Committee on Radiation Protection and Measurments (NCRP) defines the MPD for occupationally and nonoccupationally exposed persons. MPD: 0,05 Sv/year (whole body) Background radiation: 0,0036 Sv/year Avarage praxis: 0,0004-0,0008 0,0008 Sv/year Radiation protection in the veterinary practice Radiation doses received by the patient 1. The hungarian law says Radiation doses received by the vet People are not allowed to restrain the animals during the radiological procedures. Radiation protection in the veterinary practice 2. Practical possibilities The NCRP has issued a practical approach to radiaton safety in the workplace through a program known as ALARA = As Low As Reasonably Achievable General posssibilities to dicrease the radiation load 1. Immobilisation sedation - professional pros and cons - the owner s fear - financial questions - time - instruments If we have to restrain the animal If we have to restrain the animal 2

3 If we have to restrain the animal Lead apron (coat) If we have to retrain the animal Lead apron (coat) Thyroid gland protector If we have to restrain the animal Lead apron (coat) Thyroid gland protector Lead gloves If we have to restrain 3

Always use protective aprons, gloves, and shields. Keep the collimator beam as small as possible.

4 Intensifying screen, mas Intesifying screen, mas Proper planning and finishing personnel monitoring device: dosimeter (film badge) Fluoroscopy (additional radiation safety rules) Never use it in place of radiography. Always use protective aprons, gloves, and shields. Keep the collimator beam as small as possible. Never palpate the anatomic area that is being viewed while the machine is activated. Follow the rules that apply to the use of a regular x-ray machine. 4

Positional terminology Positioning The correct veterinary anatomic directional terms and abbrevations for radiographic projections follow.

5 Positional terminology Positioning The correct veterinary anatomic directional terms and abbrevations for radiographic projections follow. Left (L) Dorsal (D) Right (R) Ventral (V) Medial (M) Lateral (L) Cranial (Cr) Rostral Caudal (Ca) Plamar (Pa) Oblique (O) Plantar (Pl) Beam direction Patient positioning: basic criteria F.i.: Dorso-Ventral (DV) Welfare of the patient Restraint and immobilization of the patient Minimal trauma to the area of interest The least risk exposing those assisting with the examinaton to radiaton The patient Animals should be handled in a slow, quiet manner. Quick, loud movements and severe restraint usually result in a frightened, tense, and even aggressive patient. As much technical preparation for the exposuer as possible should be done before the animal is positioned on the table. Measurment A caliper is used to measure the anatomic area of interst. Required Views Two views Positioning the area of interest closest to the film 5

6 Collimation The smallest field size possible should be used for any given area of the body. Exposing an unnecessary large area surrounding the area of interest increases the amount of scatter radiation, which decreases the radiographic contrast. Positioning Guidelines Central x-ray beam should be centered directly over the area of interest. The measurment for any anatomic region should be taken over the thickest area. All radiographs of long bones should include the shaft of the bone, as well as the joints both distal and proximal to the bone. For joint radiography, the x-ray beam must be centered over the joint space, and the beam should include a portion of the long bones distal and proximal to the joint. Patient preparation The patient should be clean and free of any debris (artifacts!). Collars, harnesses, and leashes of any sort should be removed. Bandagaes, splints and casts should be removed, unless there is a definite medical reason for leaving them in place. Restraint, positiong aids Chemical restraint is preferred. To assist in the positiong of the animal patient, devices, such as sandbags, foam blocks and wedges, wood blocks, and radiolucent trough can be used. Tape, gauze, rope, and compression bands are also usueful. Positiong aids should not be placed under or over the area of interest. Film identification Patient identification number Marker to identify the right and left Marking sequential radiographs (f.i.: gastrintestinal contrast studies) with appropiate numbers taht identify time elapsed. 6

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Radiation Safety & Determining Need for Radiographs

Radiation Safety & Determining Need for Radiographs Guidelines for Radiographic Examination All radiation is harmful! These guidelines have been established to protect the patient and operator from unnecessary