Spine and Pelvis
Positioning Review

Spine and Pelvis
Cervical spine
•	 AP angle cephalad
•	15-20 degrees
•	Center to thyroid cartilage
•	AP of lower 5 cervical vertebrae and disk spaces
AP open mouth

lateral
•	CR directed to C4
•	72 inch distance
•	Lateral projection of all 7 vertebrae

Anterior Oblique
 
Posterior Oblique

lateral swimmers
•	Twining Method (upright)
•	Pawlow Method (recumbent)
•	Visualize C7
•	CR centered to T1 

Lateral Flexion And Extension

•	Do not attempt on trauma patients
•	CR directed to C4
•	Used to determine range of motion 
•	r/o subluxation
AP dens (Fuchs)

•	CR parallel with MML 
•	View odontoid tip
•	PA dens (Judd)
Thoracic Spine
AP T-spine
•	CR directed to T7
•	AP projection of  thoracic vertebrae
•	Anode heel effect 
Lateral T spine
 breathing or expiration
•	CR directed to T7 (no angle)
•	Make sure patient is completely aligned 
•	Breathing –long exposure time to blur the ribs
•	Expiration- shorter exposure time

AP/PA scoliosis series (Ferguson)
•	Upright PA spine (in lieu of AP to reduce RAD exposure)
•	CR directed to midpoint of IR
•	IR to include 1 inch of the iliac crests
•	Elevate patients hip or foot on the convex side of the primary curve ~ 3-4 inches

•	Right and left bending films
•	Flexion and extension films
•	AP stress

Lumbar Spine
AP
Lateral
•	 CR -5-8 degrees caudad towards L3
•	Place sponge under waist 
Posterior & Anterior Oblique 45º

L5-S1 lateral spot
•	 CR directed midway between crest and ASIS
•	5-8 degree angle caudad
AP L5-S1, 30-35º cephalad
•	CR directed to MSP approximately 1.5 inches above symphysis
AP right and left bending
•	CR directed to L3
•	Have patient bend as far to the right and left as possible
•	Used to view any changes when bending

Lateral Flexion 
And Extension

CR directed to L3
Used to determine whether motion is present in the area of spinal fusion or to localize a herniated disk as shown by limitation of motion at the site of the lesion.
Sacrum and Coccyx
AP sacrum, 15-25º cephalad
AP coccyx, 10-20º caudad

•	CR directed 10 degrees  caudad at 2 inches above the symphysis
lateral sacrum and coccyx
 combined or separate
AP Sacroiliac Joints

•	CR 30-35 degrees cephalad 
•	1.5 inches above the symphysis 
 posterior oblique& anterior oblique
Pelvis and Hip
AP hip only
Cross-table Lateral Hip
•	CR directed to femoral neck
unilateral frog-leg, non-trauma
axiolateral inferosuperior, trauma (Clements-Nakayama)

AP Pelvis
•	Patient supine
•	CR directed 2 inches above greater trochanter
•	Top of cassette above iliac crest
•	Feet rotated internally 15 degrees
AP Pelvis, Bilateral Frog-leg
AP pelvis, axial anterior pelvic bones (outlet)
•	Outlet (Taylor Method)
•	AP pelvis with CR directed 20-35 degrees cephalad for males and 30-45 degrees cephalad form females. 
•	Shows rami without foreshortening
AP pelvis, axial anterior pelvic bones (intlet)
•	Lilienfeld method
•	AP pelvis with patient seated upright and leaning back ~45-50 degrees
•	Shows a superoinferior axial projection of the anterior pubic and ischial bones and public symphysis
anterior oblique pelvis, acetabulum (Judet)
Cranium

Skull
 AP axial (Towne/ Grashey)
•	OML perpendicular to film
•	CR 30 degrees caudad to OML or 37 degrees caudad to IOML
•	PA Haas is alternative position
Townes for Skull
Lateral

•	CR directed 2 inches superior to EAM
Lateral Skull
. PA (Caldwell)
PA no angle

•	CR perpendicular to nasion
PA (no angle)            PA Caldwell
PA Facial Bones
submentovertical (full basal)

SMV for
PA 25-30º angle (Haas)
OML perpendicular to film, CR 25 degrees cephalad
(Similar to Townes)
Trauma Cross Table Lateral
Facial bones 
parietoacanthial (Waters)

•	Patient’s chin extended so OML is 37 degrees to IR

For sinuses
open mouth parietoacanthial (Waters)
•	Demonstrates the sphenoidal sinuses projected through the open mouth
Modified Waters
•	Also called Shallow waters
•	Patients neck is extended less 
•	Good to demonstrate blow out fractures
Mandible axiolateral oblique 

•	CR is 25 degrees cephalad entering at mandibular angle
Temporomandibular Joints
lateral (Law)

•	Patient in lateral position
•	IOML is parallel with the IR; rotate patient 15 degrees toward film
•	CR is 15 degrees caudad about 1.5 inch superior to EAM
TMJ lateral (Schuller)

•	Place IOML parallel to film
•	CR is 25 degrees caudad
•	For TMl, do open and closed mouth