Mistakes
A radiograph of an RAO sternum projection demonstrates the sternum slightly superimposed over the vertebral column. What positioning error most likely occurred?
Insufficient rotation
Why is an RAO position preferred for imaging the sternum over an LAO position?
Radiographic appearance of uniform density with sternum over heart shadow
Positioning landmark to ensure CR is at T3
2-3" inferior to vertebral prominens
This view of the pelvis will demonstrate the superior and inferior rami superimposed, ischial tuberosity and the obturator foramen.
AP axial Outlet
How should the patient be positioned for an axiolateral oblique projection of the mandible to demonstrate a fracture of the right ramus?
Head in true lateral with right side against IR
A lateral projection of the sternum appears magnified and the top of the manubrium and the bottom of the xiphoid process are cut off. What technical factor may have caused this?
40" SID
This radiographic appearance of a Neer shoulder is suggestive of shoulder impingement.
Subacromial spurs
Where should the central ray be directed when performing oblique projections of the sacroiliac joints?
1-inch medial to upside ASIS
For the Judet method, if the right iliac wing is elongated and the right anterior rim of the acetabulum is demonstrated, your patient is in this position.
RPO
Positioning for an axiolateral oblique projection of the mandible to demonstrate a mandibular body fracture with a perpendicular central ray. (Hint: tilt/rotation?)
25° tilt; 30° rotation
A radiograph of an oblique projection of the sternoclavicular joints demonstrates the affected joint superimposed over the vertebral column. What positioning error most likely occurred?
Insufficient rotation
When performing a tangential projection of toe sesamoids, the foot should be dorsiflexed so that the plantar surface of the foot forms what relationship to the vertical beam?
15° to 20° angle from vertical
Central ray for an AP axial projection of the pelvis to visualize the pelvic brim.
40° caudad for male or female
What position should the patient be placed in to visualize a posterior acetabulum fracture of the left hip with the Judet.
RPO
Joint classification of the temporomandibular joint (list the 3 we covered in class).
Synovial, Hinge, Gliding
A Modified Law demonstrates superimposition of the right and left mandibular condyles. What went wrong?
Insufficient rotation of the patient’s head
Which aspect of the mortise joint is best visualized with the AP stress inversion projection of the ankle?
talofibular joint
Head rotation and CR angle for a Modified Law Method for TMJ's.
15° head rotation toward the IR and angle CR 15° caudad
Where should the CR be directed when performing the Judet method to visualize the anterior acetabulum of the right hip?
2 inches distal and 2 inches medial to affected ASIS
Schuller method: Positioning, angle and CR.
Head in true lateral
Angle CR 30° caudad
Direct CR 2” superior and 1/2” anterior to upside EAM
Improper positioning for the carpal canal projection of the wrist will cause these two carpals to be superimposed.
Hamate and pisiform
An orthopaedic physician wants to assess a patient’s patellofemoral joint space with a 90° flexion. What projection will best demonstrate the area of interest?
Settegast
Gaynor-Hart projection: what central ray angulation is required to visualize the carpal sulcus of the wrist?
25° to 30° to the long axis of the hand
An RPO for the Judet method will demonstrate which obturator foramen?
Left
For the Waters method of the facial bones, the orbitomeatal line is placed at what angle to the IR?
37-degrees