1. Pelvis and Hips

2. Evaluation Criteria Structures shown Position/projection
Collimation/central ray
Exposure criteria
Acceptable and unacceptable pelvis and hip images based on errors i.e.:
Motion
Collimation
Positioning
Exposure factors
Side markers and patient demographic information
Every time a radiographer completes an image, an evaluation must be made to determine whether the image is diagnostically optimal for the radiologist to provide an accurate diagnosis. A radiologist should NEVER have to return an image for repeat if proper evaluation of the image is done by the radiographer.
Here are five basic criteria for radiographic evaluations and critique. These should be used every time a radiographic image is performed.

3. Introduction <Image 1>
The pelvic girdle is divided into three parts which are connected by cartilage in the youth and fused in the adult: ilium, pubis, and ischium. The hip is a diarthrodial, ball-and-socket joint located between the proximal extremity of the femur and the pelvic girdle. The joint is capable of a wide range of movements including flexion, extension, abduction, adduction, lateral rotation and medial rotation. The term pelvis means basin, used to describe the irregularly shaped opening created by the two hip bones, the sacrum, and coccyx. The opening within the pelvis is often separated into the greater and lesser segments, sometimes referred to as the true and false pelvis, by an oblique plane at the pelvic inlet. The pelvis transmits the weight of the upper body to the lower limbs and forms the lower part of the abdominal cavity.

4. AP Pelvis Basics <Images 2, 3>
The AP projection of the pelvis provides a general survey of the bones of the pelvis and the head, neck, and greater trochanter of each of the femora.

5. AP Pelvis Imaging Criteria
Technical Considerations
Regular IR
Grid
kVp range: 85-90
SID: 40 inches (100 cm)
IR size 14 x 17 inch (35 x45)
Patient Position
Supine on the table
Patient should be dressed in a gown with clothing from the waist down removed
Part Position
Midsagittal plane of the body should be centered to the midline of the table
Shoulder should be adjusted to lie in the same transverse plane
Elbows should be flexed with the hands resting on the upper chest
Pelvis should be adjusted so that it is not rotated (distance from the ASIS and table top is the same on both sides)
Feet should be internally rotated approximately 15 degrees
IR is positioned so that its upper border is 1 to 1 ½ inches (3-4 cm) above the iliac crest
Central Ray (CR)
CR perpendicular to the mid point of the IR (approximately 2 inches superior to the symphysis pubis)
Patient Instructions
“Take a breath and hold it, don’t breathe or move.”
Evaluation Criteria
Entire pelvis and proximal femora should be visualized
Pelvis should not be rotated as evidenced by:
Symmetrical iliac alae
Symmetrical obturator foramina
Visualization of ischial spines equally on both sides
Sacrum and coccyx aligned with the symphysis pubis
Little or none of the lesser trochanters should be visible beyond the medical edges of the femora
Greater trochanters should be fully visualized
Density should be sufficient for femoral heads to be demonstrated through the acetabula
Click each button for more information about imaging the AP pelvis.
Technical Considerations
Evaluation Criteria
Additional Information

6. Knowledge Check <Image #3>
With the legs turned in 15 degrees for an AP pelvis, what happens to the visualization of the lesser trochanter?
It is almost invisible
It is in profile
About 2/3 of the lesser trochanter is visible
It stays the same

7. AP Frog Lateral Pelvis Basics
<Images 6, 18>
The AP frog lateral pelvis (modified Cleaves method) is performed for the investigation of congenital hip disease. It is contraindicated in patients with suspected fractures or pathologic hip disease.

8. AP Frog Lateral Pelvis Imaging Criteria
Technical Considerations
Regular IR
Grid
kVp range: 85-90
SID: 40 inches (100 cm)
IR size 14 x 17 inch (35 x45)
Patient Position
Supine on the table
Patient should be dressed in a gown with clothing from the waist down removed
Part Position
Midsagittal plane of the body should be centered to the midline of the table
Shoulder should be adjusted to lie in the same transverse plane
Elbows should be flexed with the hands resting on the upper chest
Pelvis should be adjusted so that it is not rotated (distance from the ASIS and table top is the same on both sides)
Knees should be flexed and the feet drawn up as much as possible
This will place the femora to be abducted to approximately a 40 degree angle from the vertical
Central Ray (CR)
CR perpendicular to a point 1 inch (2.5 cm) superior to the symphysis pubis
Patient Instructions
“Take a breath and hold it, don’t breathe or move.”
Evaluation Criteria
Image should include acetabula, femoral heads, and necks
Pelvis should not be rotate as evidenced by:
Symmetrical iliac alae
Symmetrical obturator foramina
Visualization of ischial spines equally on both sides
Sacrum and coccyx aligned with the symphysis pubis
Lesser trochanter should be projected on the medial side of the femur
Additional Information
This is a modification of the original Cleaves method, which called for a cephalic angulation to parallel the long axis of the femora
Click each button for more information about imaging the AP frog lateral pelvis.
Technical Considerations
Evaluation Criteria
Additional Information

9. Knowledge Check <Image 18 and 20> Label the following anatomy:
Femoral head, Femoral head within acetabulum, Femoral neck, Greater trochanter, Lesser trochanter

10. AP Hip Basics <Images 8 and 13>
The AP hip is performed to visualize the head, neck, trochanter and proximal third of the femoral shaft. The AP hip is usually performed unilaterally when there is a follow up evaluation of a hip prosthesis or other orthopedic hardware and/or follow up on pathology and trauma.

11. AP Hip Imaging Criteria
Technical Considerations
Regular IR
Grid
kVp range: 85-90
SID: 40 inches (100 cm)
IR size 10 x12 inch (24 x 30)
Patient Position
Supine on the table
Patient should be dressed in a gown with clothing from the waist down removed
Part Position
Sagittal plane 2 inches medial to the ASIS of the affected side should be centered to the midline of the table
Shoulder should be adjusted to lie in the same transverse plane
Elbows should be flexed with the hands resting on the upper chest
Pelvis should be adjusted so that it is not rotated (distance from the ASIS and table top is the same on both sides)
Foot should be internally rotated approximately 15 degrees
IR should be centered to the upper limit of the greater trochanter
Central Ray (CR)
CR perpendicular to the midpoint of the IR (approximately 2 inches medial to the ASIS of the affected side at the level just above the greater trochanter)
Patient Instructions
“Take a breath and hold it, don’t breathe or move.”
Evaluation Criteria
Little or none of the lesser trochanter should be visible beyond the medial edge of the femur
Greater trochanters should be full visualized
Density should be sufficient for the femoral head to be demonstrated through the acetabulum
Additional Information
In the initial examination of the hip, an AP pelvis is often done to demonstrate the entire pelvic girdle and both upper femora
Follow-up studies are confined to the affected side
If an orthopedic appliance is in place, AEC should not be used
A larger IR may be required to demonstrate the entire prosthesis
Click each button for more information about imaging the AP hip.
Technical Considerations
Evaluation Criteria
Additional Information

12. Knowledge Check <Images 12-13>
Label the following anatomy: Ilium, Acetabulum, Femoral head, Greater trochanter, Pubis symphysis, Femoral neck, Lesser trochanter, Femoral shaft

13. Lateral Hip Basics <images 7 and 9-1>
The lateral hip provides an orthogonal image of the hip joint. Structures demonstrated on the radiograph include the proximal femur and the acetabulum. This position is contraindicated in patients with suspected fractures or pathologic hip disease.

14. Lateral Hip Imaging Criteria
Technical Considerations (image evaluation criteria)
Regular IR
Grid
kVp range: 85-90
SID: 40 inches (100 cm)
IR size 10 x12 inch (24 x 30)
Patient Position
Supine on the table
Patient should be dressed in a gown with clothing from the waist down removed
Part Position
Patient should flex the knee and turn slightly toward the affected side and abduct the leg to place the femur parallel to the IR
Center the hip (midway between the ASIS and the symphysis pubis) to the midline of the table
Unaffected leg should be extended behind the affected leg
Central Ray (CR)
CR perpendicular to the hip
Patient Instructions
“Take a breath and hold it, don’t breathe or move.”
Evaluation Criteria
Hip joint should be centered to exposed area
Any orthopedic appliance should be seen in its entirety
Additional Information
In the initial examination of the lateral hip, a bilateral frog leg pelvis is often done to demonstrate the entire pelvic girdle and lateral view of both upper femora
Follow-up studies are confined to the affected side
If an orthopedic appliance is in place, AEC should not be used
A larger IR may be required to demonstrate the entire prosthesis
This position should not be used when a fracture is suspected because of the possibility of displacing fracture fragments. A superoinferior projection should be done instead
Click each button for more information about imaging the lateral hip.
Technical Considerations
Evaluation Criteria
Additional Information

15. Knowledge Check <Image 9-1>
What is the arrow pointing at in this lateral hip image?
Femoral neck
Acetabulum,
Obturator foramen
Fractured femoral head

16. Cross Table Lateral Hip Basics
<Images 9, 16>
This lateral position of hip is indicated when the patient cannot be positioned for a routine lateral hip position. It is also called the Danelius-Miller Method.

17. Cross table Lateral Hip Criteria
Technical Considerations
Regular IR
Grid
kVp range: 85-90
SID: 40 inches (100 cm)
IR size 10 x12 inch (24 x 30)
Patient Position
Supine on the table
Patient should be dressed in a patient gown with clothing from the waist down removed
Part Position
Knee of the affected leg should be extended unless contraindicated
Unless contraindicated, internally rotate the foot to the affected side 15 degrees
Flex the knee and hip of the unaffected side and raise the leg using some suitable support for the leg
Top of the cassette should be at the top of the iliac crest and should be parallel to the femoral neck and perpendicular to the CR
Central Ray (CR)
CR horizontal, perpendicular to the hip (about 2 ½ inches or 7 cm below the intersection of the localization points described
Patient Instructions
“Take a breath and hold it, don’t breathe or move.”
Evaluation Criteria
Proximal femur, hip joint, and acetabulum should be visualized
As much as possible of the femoral neck should be visualized
Only a small portion of the lesser trochanter should be seen on anterior and posterior femur
Additional Information
To localize the long axis of the femoral neck, draw a line between the ASIS and the superior border of the symphysis pubis and note its center point.
Palpate the most prominent lateral protrusion of the greater trochanter and note a point 1 inch distal to it. A line drawn between these two point will parallel the long axis of the femoral neck
Click each button for more information about XYZ
Technical Considerations
Evaluation Criteria
Additional Information

18. Knowledge Check <Images 16-17> Label the following anatomy:
Acetabulum, Femoral head, Femoral neck, Greater trochanter, Lesser trochanter, Ischial tuberosity, Posterior surface

19. Summary
Imaging of the pelvis and hip is often performed post initial trauma where the survey images are taken to determine the extent of injury. These types of images are used to assess the orthopedic appliance and healing process.