Mobile Radiography Course 1304 RAD 1304 Instructor: TAGELDIN ABUGROON

Mobile Image intensifier (C arm)

Mobile Image intensifier Units (C arm Unit) Mobile image intensifier are designed primarily for use in any case needs screening image or immediate X-ray Visualization especially in : (A) The operation room with: 1.Orthopedic patients (for reduction & fixation of the fractured femoral neck) 2. Urinary cases (e.g. remove calculi). 3. Biliary system cases (e.g. removal gall stones). (B) The intensive care departments for : 1. Introduction of cardiac catheters. 2. Implantation of cardiac pace-maker.

Central venous Access Catheter

Peripherally Inserted Central Catheters (PICC Lines)

Placement of the Catheter

Hickman Catheter

Advantages: 1.Immediate localization & manipulation of fractures, calculi & catheters under direct vision. 2. Fewer radiographs are needed to provide the required information.( Low dose to operator & patient). 3. Reduced operation time can be achieved, which result in; (A) Less Anesthesia. (B) More efficient use of theatre operating time.

Disadvantages:  Very close control must be kept on the length of fluoroscopy which should be kept as minimum as you can to avoid accumulating dose. The method used to limit the exposure time include: 1.The use of fluoroscopic time display & alarm. 2. The used of pulsed fluoroscopy.

components of mobile image intensifier (C-arm) 1.X-ray tube with it’s collimator. 2. Image intensifier & TV camera. 3. C-arm showing rotation possible. 4. C- arm support allowing rotation. 5. Vertical column showing movement. 6. Transverse movement. 7. Control unit & HT generator. 8. Base extending forward to give stability. 9. Castors for easy movement.

components of mobile image intensifier (C-arm) 1. The tube head : ( X-ray tube & collimator) - Is mounted on the end of the of the “C” shaped arm. The X-ray tube has a dual focus,commonly: i. 0.6mm for fluoroscopy. ii. 1.2mm for radiography. - It has two collimators: 1. One to restrict the beam size to the intensifier 2. Additional one to collimate X-ray field size.

2. Image intensifier & TV camera:  They are mounted on the opposite end of the “C” arm.  The image intensifier may be 5 inch input phosphor. 3. The “C” shaped supported arm: Is mounted on a vertical column to provide: a. Considerable vertical movement. b. Rotation about the fixing to allow. i. a vertical beam. Or ii. Horizontal beam. Or iii. Angles between.

4. The vertical column: Is mounted on the mobile base. The mobile base carries: 1. The control unit (fluoroscopy factors are normally automatically control) The high tension generator ( behind the vertical column). 2. H.T generator making a counterbalance for “C” arm. All movements of the column must have secure mechanical lockers. The wheels on the base must be large to allow easy movement.

5. TV monitor trolley: A separate trolley carrying the TV monitor. 6. Power supply: 13Amp. 240 volt main. For fluoroscopy a maximum of 3mA is provided. For radiography mA with a kV range of Methods of recording the image: 1.By video-tape to record the moving image: 2. CD: Compact disc or DVD. 3. By radiography, either by the cassette holder or by sorting imaging during fluoroscopy and transfer it to the X-ray films

 Care must be taken in setting up this equipment to ensure that the x-ray tube is as far as possible from the patient to minimize the patient dose especially patient skin.  If the focus-skin distance is short the dose received by the patient will be high & the image quality will be poor which occur because of the high object-phosphor distance & enlarged image.

Exposure levels-CR Vertical PA Projection Exposure levels-CR 30 degree from vertical

Exposure patterns & levels-CR horizontal Exposure levels AP projection (Tube on Top) not recommended

Work with C arm Equipment in the Operating Room  Undertaking radiography in conditions other than the controller ones of the x-ray department has psychological effect on the radiographer especially in the operating theatre.  This work has an emergency nature, & the time factor is important. The aim usually in surgical procedures is to be as quick as is consistent with efficient, the prolonging the length of time during the patient under anesthesia will increase the patient risk, so the radiographer should be calm & fast.

Risks in Operating Theatre Risk of Importing Infection Risk of Explosion Radiation Risk

1. Risk of importing infection (Asepsis) How we can reduced this risk? A. cleaning the machine surface before and after usage by sterilized or antiseptic solution in alcohol base. B. placing a plastic cover on the places of the unit that may touch the sterilization area. 2.Risk of explosion  This risk may occurred by using ignitable anesthetic gases during exposure which sometimes produces sparks.  These sparks could be produced from the units wheels or from the electrical parts of the control panel.

How the risk of explosion can be eliminated? (A). using non- ignitable anesthesia gases. (B). special conducting wheels, which manufactured by conducting material to pass small currents from static charges directly to the theatre ground (earthing). (C). special spark-proof X-ray units and electrical plugs are used. Radiation Risk  This risk involves anyone in operating theatre. The radiation protection is the responsibility of the radiographer before starting any exposure.

How the Radiation Risk can be minimized in OR? (1).Wearing lead apron, thyroid collar, glasses, gloves and TLD, the Radiological technologist and the staff must wearing this accessories during fluoroscopy and during taking radiographs. (2) Using the inverse square law with the staff: How? i. By standing at maximum distance. ii. By standing outside from the path of radiation source. (3) Collimation the radiation beams on the required area of the patient. (4) Minimize the screening time as possible as you can. (5)Giving clear instructions to staff before any exposure is made.

Inverse square law I 1 / I 2 = ( d 2) 2 / ( d 1) 2

Lead Apron & Thyroid Shield

Lead Gloves & Goggles

Mobile Barrier Mobile Curtain Face Shield

Collimator

Special Concerns:  In many modern theatre suites it is normally that you find a special room for the x-ray equipment & for processing facilities.  The first thing that the radiographers must be concerned with, is their own personal preparation entering an aseptic controlled area. The radiographer should change clothes & wearing theatre uniform & wear (shoe cover, hair cover, mask & washing hand).  Before unit is removed from it’s store & after it is placed in the theatre, it should be tested. This procedure should be done before surgical procedure.

 The processing equipment should be switched on & tested. Adequate levels of replenisher solutions & supply of cassettes & films should be checked.  All needed accessory equipment should be available (e.g cassette holder).  Always the examination request should be checked before starting the preparation.

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