advanced chest- image analysis

technique for Ap erect litter chest

24 cm pt - 90 kVp @1.6 mAs

(for every 1 chmthickness change= +/- 2 kVp)

Rh note for Ap erect litter chest

use grid on pts over 30 cm and adjust technique accordingly

central ray for AP erect litter chest

tube should be angled to match pt angle, central ray enters 3" below jugular notch on midsaggital plane

special views for CXR

AP axial, AP supine

AP axial CXR

45 SID, 14 x 17 CW collimation

merrills note for AP axial CXR

use 72 SID

RH note for AP axial CXR

use 45 SID to decrease magnificatino of heart bc equipment cant reach 72 SID when in supine position

piggostat CXR age range

3 months - 2.5 years, parent holds child’s hand up (has to deny pregnancy), crying gives better inspiration

technical factors for piggostate CXR

80-90 kVp, center cell (1 mAS if not AEC, 2 mAs for lateral), techniques can varry based of pt age and size, 8 x 10 collimation or 10 x 12 LW then collimate to area of interest

PA Pigg-O- Stat Merrill’s note

collimation should extend from and include the mastoid tips to 2 inches above the iliac crests.

central ray for peds

nipple line

AP erect litter (or wheelchair) CXR evaluation criteria:

1. everything is still the same critique, however…..

2. clavicles appear more horizontal than on the PA projection

3. approx. 1 inch of pulmonary apices should be seen superior to clavicles

4. annotate “AP ERECT”

how to know if there is not enough tube angle on AP erect litter CXR

clavicles are too high

how to know if there is rotation on AP erect litter CXR

there is a major space between the clavicles
ex: major space between R clavicle means rotated towards R side

PA pigg-o-state evaluation criteria

same as chest PA

PA vs AP ribs rotation

PA- away- elongated ribs
AP- towards- elongated ribs

wires for children __ years and under should be removed unless the nurse or doctor says otherwise

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what side to mark for CXR decubitus 

mark side down

what side to mark for CXR decubitus in NICU

mark the side up

is clipping on the side we don’t want okay?

yes because it is not the side of interest

if looking for fluid what side to lay on? (merrill’s)

lie on affected side 

if looking for air what side to lay on? (merrill’s)

unaffected side

CXR decubitus- Right or Left lateral position criteria

• no rotation of the patient demonstrated by the sternal ends of the clavicles equidistant from the spine

• patients arms or chin not visible in the field of interest

• faintly visible spine and pulmonary vascular markings from the hilar regions to the periphery of the lungs

• Annotate DECUBITUS on the image

technique for lateral CXR on litter or chair

• 120 kVp

• Erect IR- center cell (3.6 mAs if not AEC)

• 14 × 17 LW

• 72 inch SID

technique for AP erect (patients who can’t stand or sit on side of litter)

• using calipers, measure front to back at mid sternal area is order to select appropriate technique

  • ex: 24 cm patient- 90 kVp @ 1.6 mAs

• 72 inch SID

• 17 × 14 CW

how much should you change your kVp by when measuring patient thickness

±/- 2 kVp

Decubitus CXR (AP or PA) technique

• 120 kVp

• AEC cells vary (2.0 mAs if not AEC)

• Erect IR

• 72 inch SID

• 14 × 17 LW

AP axial (lordotic)

• 72 inch SID

• 14 × 17 LW or CW

• patient needs to be 1 foot away from erect IR

• lean back against the IR about (15-20 degrees from vertical)

Merrill’s criteria for AP axial

• if patient can not lean back from an erect position, the patient can stand or lay AP with their back against the IR and a 15-20 tube cephalic tube angle directed to the center of the manubrium can be applied

AP supine

• RH: 45 SID

• 14 × 17 CW

Merrill’s note for AP supine

• recommends 72 inch SID

  • RH equipment cannot reach 72 inch SID so they go with 45 inches instead of 40 to help decrease magnification and more easily include entire lungs on image

Chest Pigg-O-Stat Routine

• at wall detector

• 72 inch SID

• 8 × 10 or 10 × 12 collimation

• left marker in light field

Pediatric Chest PA- Pigg-O-Stat

• 80-90 kVp

• Erect IR (1.0 mAs if not AEC)

• 72 inch SID

• 8×10 or 10×12 LW

• erect marker

Pediatric chest lateral- Pigg-O-Stat

• 80-90 kVp

• erect IR (2.0 mAs if not AEC)

• 72 inch SID

• 8×10 or 10×12 LW

Pediatric chest PA- standing

• 80-90 kVp

• Erect IR ( 1.0 mAs if not AEC)

• 72 inch SID

• 8×10 or 10×12

Pediatric chest lateral- standing

• 80-90 kVp

• erect IR (2.0 mAs if not AEC)

• 72 inch SID
  8×10 or 10×12