This document evaluates an AP knee x-ray image for quality, positioning, and compliance with standards. It finds that the image meets acceptance criteria overall but could be improved by better centering and removing artifacts. While diagnostic, the striped pattern over the distal femur should be identified and avoided in future images. Proper positioning and technique were utilized, though the contrast appears more grey than black and white as preferred.

1. +
AP KNEE
PAIGE KAUFFMAN

2. +
IS THIS IMAGE HIPAA COMPLIANT?
 Yes, this image is HIPAA
compliant as it does not display
any information that violates
HIPAA compliancy.

3. +
MARKER & PATIENT ID
 The correct anatomical side marker is
placed on the lateral side making it
appear on the viewer’s left in relation
to the part
 The marker was placed beside the
anatomical part prior to the exposure
 The anatomical marker correctly marks
the side being imaged
 The marker is not superimposing any
pertinent anatomy
 There are no additional markers
needed/ used for this image
 Could use “weight bearing” markers if
knee was ordered weight bearing
 Based on the marker placement the
image is correctly displayed

4. +
RADIATION HYGIENE
 Proper beam restriction requires the
presence of at least three sides of
collimation on the image
 There are at least three sides of beam
restriction present
 Black boarder
 There is evidence to prove primary
shielding was used because there is
collimation on the side closest to the
gonads
 I shielded the patient
 Gonadal shielding must be provided if
gonads are within 5 cm of the
primary beam

5. +
ROUTINE RADIOGRAPHIC
PROJECTION PERFORMED:
 AP
 45 degree Oblique
 Medial rotation
 Lateral rotation
 Lateral
 mediolateral
Other Projections May Include:
• Cross Table Lateral “Shoot Thru”
• Tangential “Sunrise” Method
• Knees AP Weight – Bearing
• Knees PA Weight – Bearing, Rosenberg
• Intercondylar Fossa
• PA Axial Holmblad
• PA Axial Camp-Coventry
• AP Axial Beciere
** Projections differ based on
institutional / departmental protocls

6. +
 This image complies with routine
position(s) / projections
 ALL anatomical parts correctly
visualized

7. +
ARTIFACT IDENTIFICATION
 There appears to be an artifact
on the medial side of the knee
along with a striped-pattern over
the distal femur
 No body parts superimposed that
should not be
 There appears to be hospital
paraphernalia ( crinkled bed
sheet)
 There appears to be no
indwelling artifacts/ foreign
bodies visible

8. +
ARTIFACT IDENTIFICATION / IMAGE
SHARPNESS
 There does not appear to be excess
fog that could degrade overall image
contrast/ visibility of recorded detail &
there are no visible CR/DR artifacts
 The image contrast is quite grey making
it long scale contrast
 There appears to be “gross” voluntary
motion due to the bony trabeculae
being well visualized throughout the
image
 There is no excessive quantum mottle
visible
 There is no evidence of double
exposure
 There are no grid lines, grid artifact &/
or grid cut off due to the likelihood of
the use of a high frequency or
reciprocating grid

9. +
** Grids should be used w/ body
parts that measure more the 10cm
 Avg knee measures 9-13 cm, where non-grid or gird technique
can be employed
 Dependent upon patient knee size, radiographer/ physician
preference, department protocol
 Bontrager:
 Non-grid for smaller patients, with knees measuring 10cm or less
 Grid for larger patients, with knees measuring 10cm or more

10. +
IMAGE SHARPNESS
 Size distortion does not appear greater
than expected
 The CR should enter 1cm (1/2 inch)
below the patellar apex
 Off-centering is ≤1 cm –
shape distortion is
minimal
 Correct centering, alignment, CR
location = important to avoid shape /
size distortion
 Narrow joint spaces clearly demonstrated
 CR angle improves visualization of joint
spaces

11. +
Visualization of Joint Space
 To ensure CR is parallel to tibial plateau, & to visualize an open
joint space, measure distance between ASIS to table top to
determine CR angle …
 Angle is varied depending on the measurement
 <19 cm 3-5 degrees CAUDAD
 Thin patient
 19-24 cm 0 degrees
 Average patient
 > 25 cm 3-5 degrees CEPHALAD
 Thicker patient

12. +
ACCUARATE PART POSITIONING
 The part is adequately aligned to the
longitudinal axis of the imaging media
 The part is not centered to the image
media
 The CR is not centered within 1 cm of
the anatomical part
 The CR is not adequately aligned with
the image media due to the irregular
amounts of beam restriction used
 The CR’s alignment does conform to
an accepted IR exposure field
recognition template / field

13. +
POSITIONING
 IR Size: 10 x 12 inch, lengthwise
 40 in SID
 Place patient in the supine
position, and adjust the body so
that the pelvis is not rotated

14. +
Positioning
 With the IR under the patients knee, flex the joint slightly, locate
the apex of the patella and as the patient extends the knee,
center the IR about ½ inch below the patellar apex. This
centers the IR to the joint space
 Adjust the patients leg by placing the femoral epicondyles
parallel with the IR for a true AP projection. The patella lies
slightly off center to the medial side
 If the knee cannot be fully extended, a curved IR may be used
 SHIELD GONADS
 Collimate to 10 X 12 inch

15. +
EVALUATION CRITERIA
 Knee fully extended if patient’s
condition permits
 Entire knee without rotation
 Femoral condyles symmetric and
tibia intercondylar eminence
centered
 Slight superimposition of the
fibular head if the tibia is normal
 Patella completely superimposed
on the femur
 Open femorotibial joint space,
with interspaces of equal width
on both sides if the knee is
normal
 Soft tissue and bony trabecular
detail
 Evidence of proper collimation

16. + IMAGE EVALUATION
 Knee fully extended ✔
 Entire knee without rotation ✔
 Femoral condyles symmetrical ✔
 Tibia intercondylar eminence centered ✔
 Slight superimposition of the fibular head ✔
 Open femorotibial joint space, with
interspace of equal width on both sides ✔
 Soft tissue & bony trabecular detail ✔
 Evidence of collimation ✔
IS THE ANATOMICAL PART CORRECTLY POSITIONED?
YES

17. +
EXPOSURE TECHNIQUE
 The most radiolucent structure is the soft
tissue margins and the joint space
 The most radiopaque structure is the bony
cortex
 The images contrast is more on the grey
side therefore it has long scale contrast
 Since there is no EI value present it is
difficult to determine if the image is
adequately exposed
 Since I took the image and it was
accepted by the techs, it is in normal
range of the hospital EI values, and is
adequately exposed !! But it should be
short scale contrast (black & white) and
the image looks more long scale (grey)

18. +
ACCEPT OR REJECT?
 This image meets the standards
for acceptance criteria but the
striped pattern artifact over the
distal femur is concerning!
 It is of diagnostic quality
 I would / did accept this image
 No repeat necessary, however I
would change ..

19. +
 I would change the centering of the
position to the image media. I
centered the CR to the base rather
than the apex seen on the image.
 And make sure there are no
crinkled sheets that could be seen
in the x-ray.
 I would also identify what the
striped-pattern artifact over the
distal femur was caused by and try
and remove it!

20. +
REFRENCES
 Frank, E. D., Long, B. W., Smith, B. J., & Merrill, V. (2012).
Merrill's atlas of radiographic positioning & procedures. St.
Louis, MO: Elsevier/Mosby.
 McQuillen-Martensen, K. (2015). Radiographic image
analysis. St. Louis, MO: Elsevier Saunders.
 Picture: BY ME @ Nazareth Hospital