Abdominal positioning and anatomy Flashcards
Radiographic principles and technical factors of the abdomen
One projection should be sufficient
Anterior-Posterior (AP) Supine is the standard projection.
Lateral Decubitus views (Decubitus and Dorsal Decubitus) can be helpful to look at foreign bodies/ perforation.
AP Erect can be taken to visualise air/fluid levels- not routinely done.
KUB for Intravenous Urograms (IVU) or any study relating to renal colic.
Source-to-Image Distance (SID) = 110cm.
Image Receptor Size = 35cm x 43 cm (portrait)
Grid is standard and AEC controls are advised
Focal Spot Size = Broad
Justification for abdomen
FB? / Query foreign body
Distention in a paediatric patient
Obstruction?
Abdominal pain (acute/ non-specific)
BNO = Bowels not opened
Transit studies
Toxic Megacolon
Diverticulitis
Barium follow through
Shunt series
NG tubes – should be CXR
Cholecystitis – should be U/S
Constipation – Clinical examination
Lost intrauterine coil – should be U/S
Perforation
Unless they are in extreme pain cannot perform erect CXR
Appendicitis? – Should be CT or U/S
Pancreatitis? – Should be CT, U/S or ERCP
Back ache – Lumbar Spine XR
AP supine positioning
Patient is positioned with their back against the image receptor
AC joints equidistant from the table
Iliac Crests equidistant from the table
The median sagittal plane is perpendicular to the image receptor
The patient’s arms can be by their side or above their head
AP supine positioning
The x-ray tube is positioned vertically and perpendicular to the image receptor
Locking the tube to the table bucky is required
Most systems will inhibit x-rays until the tube is locked
The centering point is midway between the xiphi-sternum and the symphysis pubis in the median sagittal plane (MSP)
Collimation should include:
Superiorly: The diaphragm
Inferiorly: Symphysis pubis
Bi-laterally: Skin margins
AP supine positioning
A grid is required
AEC (usually side chambers) should be used
SID = 110cm
Focal Spot Size = Broad
Exposure made on arrested EXPIRATION
“Breathe in, breathe out, and stop breathing… x-ray … breathe normally”
Estimated collimation size = 35 X 43 cm
Image Receptor = Portrait orientation
Given Exposure Factors:
75 kV & 32 mAs
AEC should always be used when possible
Anterior-Posterior (AP) erect abdomen
Patient positioned in true AP erect position
AC joints equidistant from vertical bucky
Iliac Crests equidistant from vertical bucky
MSP perpendicular to the IR
Patient can be standing or seated upright
Central Ray must be horizontal and perpendicular to the IR
The centering point is midway between the xiphi-sternum and the symphysis pubis in the MSP
Collimate to include:
Superiorly: Diaphragms
Inferiorly: Symphysis Pubis
Laterally: Skin Margins
Exposure made on arrested EXPIRATION
Estimated collimation size = 35 X 43 cm (portrait)
Grid with AEC required
SID = 110cm
Exposure factors: 75 kV & 32 mAs, Broad focus
Lateral decubitus abdomen
Utilised as alternative view, IF patient cannot tolerate erect film (either PA/AP Chest or AP Abdomen).
Patient lying on left side for 10 minutes prior, to allow air to rise
Patient positioned in lateral position
AC joints aligned or superimposed with the bed
Iliac Crests aligned or superimposed with the bed
MSP perpendicular to the IR
Central Ray must be horizontal and perpendicular to the IR
The centering point is midway between the xiphi-sternum and the symphysis pubis in the MSP
Collimate to include:
Superiorly: Diaphragms
Inferiorly: Symphysis Pubis
Laterally: Skin Margins
Exposure made on arrested EXPIRATION
Estimated collimation size = 35 X 43 cm (portrait)
Grid with AEC required
SID = 110cm
Exposure factors: 75 kV & 32 mAs, Broad focus
What is a KUB?
Positioning:
As for abdomen supine
The symphysis pubis should be clearly visible
Ensure none of the bladder is cut off
Collimate laterally to the ASIS for the gold-standard image
Include the diaphragm superiorly or at least both kidneys
