Unit VI Special Imaging Systems Chapter 39 Mobile Radiography.

Unit VI

Special Imaging Systems

Chapter 39

Mobile Radiography

Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 4

Objectives

• Identify factors contributing to the difficulty of mobile radiography

• Explain appropriate communications methods for mobile examinations

• Describe items that must be considered when arranging a patient room for a mobile examination


Objectives

• Recommend methods for accomplishing acceptable variations of standard radiographic projections, especially chest examinations for air-fluid levels

• Assess the radiation protection rules for mobile radiography


Objectives

• Differentiate light duty portable x-ray units for mobile radiography

• Evaluate advantages of capacitor discharge and battery powered mobile units

• Explain why technical factor selection is more difficult during mobile radiography


Objectives

• Describe effect of various generator waveforms on kVp

• Identify advantages of standardizing mobile SID to one of 40” (100 cm), 56” (140 cm) or 72” (180 cm)


Objectives

• Determine appropriate grids for mobile examinations

• Appraise various film/screen combinations for mobile application


Special Patient Considerations

• Communication

• Manipulating equipment

• Positioning and pathology


Communication

• Park mobile unit outside patient’s room– Establish rapport– Get patient’s permission to do the exam– Explain the procedure– Move items that will be in the way

• Incognizant patients

• Surgery/Emergency Room/ICU


Manipulating Equipment

• Watch out for:– Equipment power supplies– Oxygen tubing– Intravenous lines– Catheters, etc.


Manipulating Equipment

• Don’t bump the bed or your head

• Radiographer’s responsibility to return all items to their original locations


Positioning and Pathology

• Maintain typical positioning for examinations

• Perform chest radiography in semi-erect position whenever possible


Positioning and Pathology

• Increased possibility of artifacts– Remove all radiopaque objects– Move lines from imaging field if possible

• Limit coverings to single, smoothed layer


Demonstration of Air-Fluid Levels


Types of Equipment

• Power supplies

• Generators

• Power drive


Power Supplies

• Portable light duty units– 220V or 110V outlet

• Full power mobile institutional units– Capacitor discharge– Battery operated


Generators

• Capacitor discharge– Constant potential

output

• Battery operated – 3 phase output


Power Drive

• Self-propulsion for mobile unit

• Dead-man switch

• Must use caution when piloting equipment


Special Technical Factor Selection Considerations

• Kilovoltage

• Milliampere-seconds

• Distance

• Grids

• Film/screen combinations

• Other factors


Milliampere-Seconds

• Low power units not capable of high mAs techniques needed for grid radiography

• Double or triple exposure– Be careful not to overload tube


Distance

• Must be measured accurately

• 40”• 56”• 72”


Grids


Film/Screen Combinations

• Wide latitude image receptor appropriate

Unit VI Special Imaging Systems Chapter 39 Mobile Radiography.

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Transcript of Unit VI Special Imaging Systems Chapter 39 Mobile Radiography.