Bariatrics In Radiography Flashcards
What is obesity
An increase in body weight by excessive accumulation of fat
BMI greater than 40 is considered morbidly obese
How grids affect imaging of bariatric patients
Reduces scatter in obese patients
Use of a grid with high ratio 8:1 or 10:1 can reduce scatter and improve image quality
Grids also improve anatomic detail by reducing scatter and increasing SNR
Grids also increase patient dose and can cause grid errors (most common is grid cut off)
Equipment consideration with bariatric patients
Tables in x-Ray, CT and MRI have weight limits identified by manufacturer (300-700lbs)
Do not put them on one if they exceed weight limitations
always have table in lowest position possible and centered to decrease weight load on table and do not float the table
Transportation, Transfer and Movement of bariatric patients
Special beds and stretchers to move larger patients
Power lifts installed in DI and patient wards
Always be sure adequate personnel are available to assist and that transfer tools such as sliders are available
Communicate each part of the transfer process to the pt
Positioning landmarks and bariatric pt
Ensure they are positioned to the centre of the table
Realize that the skeleton and organ have not changed position and they are not any larger
Most positioning landmarks will be reference to the MSP of the pt
Jugular notch may be the only landmark available for palpating
Most landmarks will not be accessible on the morbidly obese
How to find symph on obese pt
Measure from jugular notch base on pt height
5ft - 21” or 53cm
5-6ft - 22” or 56cm
>6ft - 24” or 61cm
Mobile Exams on obese patients
May be restricted to chest and limbs only as machines exposure factors need to be high enough to penetrate the patient
Using a grid will increase contrast resolution
Exposure factors
Increasing kVp will increase the penetration of the beam
mA for obese patients may be higher than 250-320
Selection of a larger focal spot for all but distal limbs
Maintain a special exposure chart for obese patients for reference and lowering the number of repeats
Technical considerations for working effectively with obese patients
Warm up tube before making any exposures
Use lower mA setting (<320) and higher kVp setting
Do not make repeated exposures near tube limits
Use the large focal spot for all but distal limbs
Do NOT use APR to determine exposure technique
When using AEC ensure kVp is high enough and mA is moderate
Collimate to the size of the IR or smaller
With DR collimate to suggested field size for the projection
Never collimate to max size of flat panel DR detector
Maintain special exposure chart for obese patients
Stand at right angles (90 degrees) to the CR when holding obese pt
IR size and collimation
Using proper IR and standard collimation practices will reduce scatter on the image
For abdomens images it may be necessary to take multiple images on quadrants of the body using smaller collimation settings
The collimator should never be set to larger that the size of the IR
