Chest & Abdomen
On an upright abdomen, this anatomy must be included to evaluate for free air.
Diaphragm
Explanation:
For free air, you need to see beneath the diaphragm, especially on upright chest or abdomen images.
A lateral ankle should show the distal fibula projected over this portion of the tibia.
Posterior Half of the Tibia
Explanation:
A lateral ankle shows the distal fibula superimposed over the posterior portion of the distal tibia.
The CR for an AP axial skull, Towne method, is angled this direction.
Caudad
Explanation:
The AP axial skull, or Towne method, uses a caudad CR angle.
This factor primarily controls radiographic contrast.
kVp
Explanation:
kVp primarily controls contrast by affecting beam penetration and the scale of gray.
This protective device should be worn at the thyroid level during fluoroscopy.
Thyroid Shield
Explanation:
The thyroid is radiosensitive and should be protected during fluoro when possible.
On a KUB, the image should include the abdomen from the diaphragm or upper kidneys down to this structure.
Pubic Symphysis
Explanation:
A KUB should include the kidneys, ureters, and bladder region.
An AP oblique medial rotation of the foot best demonstrates this side of the foot.
Lateral Side
Explanation:
AP oblique foot with medial rotation best demonstrates the lateral foot, including the 3rd through 5th metatarsals.
The open-mouth odontoid view is primarily used to demonstrate this structure.
Dens/Odontoid Process
Explanation:
The open-mouth view demonstrates C1, C2, and the dens.
Motion blur can be reduced by decreasing this exposure factor.
Exposure Time
Explanation:
Shorter exposure time reduces motion blur. Tiny time, crisp crime.
During C-arm imaging, the image intensifier should generally be placed as close as possible to this.
Patient
Explanation:
Keeping the image intensifier close to the patient reduces dose and improves image quality.
A decubitus abdomen for free air usually requires the patient to lie on this side.
Left Side
Explanation:
Left lateral decubitus abdomen is commonly used so free air rises along the right side away from the gastric bubble.
The scaphoid is best demonstrated when the wrist is placed in this deviation.
Ulnar Deviation
Explanation:
Ulnar deviation opens the scaphoid and helps reduce foreshortening.
A lateral thoracic spine commonly requires orthostatic breathing technique to blur this anatomy.
Rib and Lung Markings
Explanation:
Breathing technique helps blur ribs and lung detail over the thoracic spine.
Increasing OID causes increased magnification and this loss of image quality.
Spatial Resolution / Detail
Explanation:
Increased OID increases magnification and decreases recorded detail.
The person standing closest to the x-ray tube during fluoro generally receives more this.
Scatter Radiation
Explanation:
The tube side produces more scatter exposure to nearby staff.
On a PA chest, poor inspiration is suspected if fewer than this many posterior ribs are visible above the diaphragm.
10 Posterior Ribs
Explanation:
A good PA chest inspiration usually shows about 10 posterior ribs above the diaphragm.
A radial head-capitellum view is commonly used to evaluate this injury.
Radial Head or Radial Neck Fracture
Explanation:
The trauma oblique/radial head-capitellum view helps evaluate radial head and neck injuries.
In a properly positioned AP open-mouth, these two structures should be superimposed.
Upper Incisors and Base of Skull
Explanation:
For an open-mouth odontoid, the lower edge of the upper incisors should align with the base of the skull.
When using AEC, placing the wrong chamber under dense anatomy may cause the image to be this.
Overexposed / Too Dark
Explanation:
With AEC, placing the chamber under dense anatomy can cause the machine to keep exposing too long.
Pulsed fluoroscopy helps reduce this.
Patient and Staff Dose
Explanation:
Pulsed fluoro reduces radiation output compared with continuous fluoro.
On a left lateral decubitus chest, the suspected free air or fluid is demonstrated because of this physical principle.
Gravity
Explanation:
Air rises and fluid layers dependently. Decubitus views use gravity to show air-fluid levels or free air.
For a lateral hand, the fingers should be positioned this way to avoid superimposition.
Fanned/Separated
Explanation:
A lateral hand should have the fingers fanned to avoid superimposition, unless a specific finger or trauma protocol says otherwise.
The “Scotty dog” is seen on this spine projection.
Oblique Lumbar Spine
Explanation:
The Scotty dog appears on oblique lumbar projections.
If a grid is used accidentally for a small pediatric extremity, the image may show unnecessary dose and reduced this if positioning is off-center.
Receptor Exposure/Image Quality
Explanation:
Grid cutoff can happen if positioning or centering is wrong, especially with focused grids. In small anatomy, grids may be unnecessary and can increase dose.
In the OR, the safest place to stand during lateral C-arm imaging is generally on this side.
Image Intensifier/Detector Side
Explanation:
During lateral C-arm imaging, the tube side has more scatter. Stand on the detector side when possible.