Registry 2025 - Radiographic Positioning & Procedures – Master Projections

Vocabulary-style flashcards summarizing key radiographic projections, tube angles, central-ray locations, patient positioning, and anatomy demonstrated across skull, facial bones, spine, thorax, abdomen, and extremities.

AP Axial (Towne) – Skull

30° caudal to OML (37° to IOML); CR 2″ above glabella; dorsum sella in foramen magnum / occipital bone in profile.

Lateral Skull

IPL perp to IR; CR 2″ above EAM; shows entire cranium & sella turcica.

PA Axial (Caldwell) – Skull

OML forms 15° angle with beam; CR exits nasion; petrous ridges in lower third of orbits.

PA Skull

OML ⟂ IR; CR exits glabella; petrous ridges fill orbits; best for frontal bone.

SMV (Schüller) – Skull

IOML ∥ IR; CR midway between gonions; mentum anterior to ethmoid region.

Trauma AP Axial (Reverse Caldwell)

OML ⟂ IR; 15° cephalic; CR nasion; petrous ridges in lower third of orbits (supine trauma).

Trauma AP Skull

OML ⟂ IR; CR glabella; petrous ridges fill orbits; evaluates frontal bone (supine).

Trauma AP Axial (Towne) – Skull

30° caudal to OML (37° to IOML); CR 2″ above glabella; occipital bone / dorsum sella in FM (supine).

Lateral Facial Bones

IPL ⟂ IR; CR midway outer canthus–EAM; demonstrates all facial bones & sinuses.

Waters – Facial Bones

MML ⟂ IR; CR acanthion; petrous ridges below maxillary sinuses; shows maxillae.

PA Axial (Caldwell) – Facial Bones

OML 15° from horizontal; CR nasion; petrous ridges in lower third of orbits.

Modified Waters – Facial Bones

LML ⟂ IR; CR acanthion; shows orbital floors; good for blow-out fractures.

Axiolateral Oblique – Mandible

25° cephalic tube & head rotation (0–45°) to profile rami, body, or mentum per rotation.

PA Mandible

OML ⟂ IR; CR junction of lips; visualizes mandibular rami.

AP Axial (Towne) – Mandible

OML ⟂ IR; 35° caudal; CR 1″ above glabella; condylar processes in fossa.

PA Axial Mandible

OML ⟂ IR; 20–25° cephalic; CR acanthion; condylar heads/neck.

Modified Waters – Mandible

LML ⟂ IR; CR acanthion; demonstrates condyles and TM fossae.

SMV – Mandible

IOML ∥ IR; CR midway between gonions; entire mandible shown.

TMJ Axiolateral Oblique (Modified Law)

Head rotated 15° toward IR; CR 15° caudal, 1.5″ above upside EAM; shows side down TMJ (open/closed).

TMJ Axiolateral (Modified Schüller)

Head true lateral; CR 20-30° caudal, ½″ anterior & 2″ superior to upside EAM; side-down TMJ.

TMJ AP Axial (Modified Towne)

OML ⟂ IR; 35° caudal; CR 3″ above nasion; condyles & TM fossae.

Nasal Bones – Waters

MML ⟂ IR; CR acanthion; evaluates deviated septum, petrous ridges below sinuses.

Nasal Bones – Lateral

IPL ⟂ IR; CR ½″ inferior to nasion; both laterals taken for comparison.

Orbit – Waters

MML ⟂ IR; CR acanthion; petrous ridges below maxillary sinuses; orbital rims.

Orbit – Lateral

IPL ⟂ IR; CR midway outer canthus–EAM; superimposed orbital rims.

Orbit – PA Axial

OML 15° from horizontal; CR nasion; maxillary sinuses in lower ⅓ of orbits.

Orbit – Modified Waters

LML ⟂ IR; CR acanthion; orbital floors in profile (blow-out).

Sinus – Lateral

IPL ⟂ IR; CR midway outer canthus–EAM; shows all four sinus groups (upright).

Sinus – PA Axial (Caldwell)

OML 15° from horizontal; CR nasion; frontal & ethmoid sinuses.

Sinus – Waters

MML ⟂ IR; CR acanthion; maxillary sinuses best, petrous ridges below.

Sinus – SMV

IOML ∥ IR; CR midway between gonions; sphenoid & ethmoid sinuses.

Cervical Spine – AP Axial

15° cephalic; CR C4; opens intervertebral disc spaces C3-T1.

C-Spine – AP Open Mouth

CR through open mouth; shows atlas/axis – lateral masses of C1 & body of C2.

C-Spine – Lateral

72″ SID; CR C4; shoulders depressed; shows zygapophyseal joints.

C-Spine – PA Axial Oblique

15° caudal; CR C4; demonstrates downside intervertebral foramina.

C-Spine – AP Axial Oblique

15° cephalic; CR C4; demonstrates upside intervertebral foramina.

Swimmer’s (Cervicothoracic)

5° caudal; arm closest to IR raised; CR 1″ above jugular notch (T1); separates C7-T1.

Fuchs Method

Supine; MML ⟂ beam; CR mental point; odontoid apex through foramen magnum.

Thoracic Spine – AP

CR T7; shows intervertebral joint spaces.

T-Spine – Lateral Breathing

CR T7; patient breathes to blur ribs; shows intervertebral foramina.

Lumbar Spine – AP / PA

CR iliac crest; demonstrates intervertebral joints.

Lumbar Spine – Lateral

CR crest; shows intervertebral foramina.

L5-S1 Spot (Lateral)

5-8° caudal; CR 1.5″ below crest & 2″ posterior to ASIS; opens L5-S1 space.

Lumbar Posterior Oblique

RPO/LPO; CR 1-2″ above crest & 2″ medial to upside ASIS; side-down zygapophyseal joints.

Lumbar Anterior Oblique

RAO/LAO; CR 1-2″ above crest & 2″ medial to downside PSIS; side-up zygapophyseal joints.

AP Axial L5-S1 (Ferguson)

30-35° cephalic; CR at ASIS; opens L5-S1 joint.

AP Sacrum

15° cephalic; CR 2″ below ASIS; shows entire sacrum & SI joints.

AP Coccyx

10° caudal; CR 2″ below ASIS; coccyx free of superimposition.

Lateral Sacrum/Coccyx

CR 3-4″ posterior to ASIS; sacrum, L5-S1 & coccyx in profile.

SI Joints – AP Axial

30-35° cephalic; CR 2″ below ASIS; open SI joints & L5-S1.

SI Joint – Posterior Oblique

25-30° oblique; CR 1″ medial to upside ASIS; shows upside SI joint.

SI Joint – Anterior Oblique

25-30° oblique; CR 1″ medial to upside PSIS; shows downside SI joint.

AP Hip

CR femoral neck (1-2″ medial, 3-4″ distal to ASIS); proximal femur & acetabulum.

Cross-table Lateral Hip (Danelius-Miller)

IR vertical, beam ⟂ femoral neck; profiles femoral neck (trauma).

Frog-Leg Lateral Hip

Leg abducted 45°; CR femoral neck; shows femoral head/neck & trochanters.

Clements-Nakayama

CR ⟂ femoral neck; IR tilted 15°; modified cross-table for bilateral hip fractures.

AP Pelvis

CR 2″ inferior to ASIS; entire pelvis & proximal femora.

Pelvic Inlet View

40° caudal; CR at ASIS; demonstrates pelvic brim/ring.

Pelvic Outlet View

30° cephalic (male); CR to greater trochanter; shows pubic & ischial rami.

Oblique Acetabulum (Judet) – Downside

45° posterior oblique; CR 2″ distal & 2″ medial to downside ASIS; anterior rim & iliopubic column.

Oblique Acetabulum (Judet) – Upside

45° posterior oblique; CR 2″ distal to upside ASIS; posterior rim & ilioischial column.

Chest PA

Upright; CR T7; full lung fields, air-filled trachea, 10 ribs above diaphragm.

Chest Lateral

CR T7; arms raised; entire lungs without rotation.

AP Lordotic Chest

Patient leans back; CR midsternum; projects clavicles above apices.

Chest Lateral Decubitus

CR T7; side down for fluid, side up for free air.

Ribs – Above Diaphragm

CR 3-4″ below jugular notch; ribs 1-9 in inspiration.

Ribs – Below Diaphragm

CR midway between xiphoid & lower rib margin; ribs 10-12 on expiration.

Oblique Ribs

45° oblique; CR same level as affected ribs; elongates axillary ribs.

Sternum – RAO

15-20° RAO; CR midsternum; uses breathing technique; sternum over heart shadow.

Sternum – Lateral

CR midsternum; arms back; entire sternum free of superimposition.

Soft Tissue Neck – AP

AML ⟂ IR; CR 1″ above jugular notch; air-filled trachea.

Soft Tissue Neck – Lateral

CR C6-C7; slow inspiration; air-filled larynx & trachea.

SC Joints – PA

CR T2-T3 (3″ distal to VP); bilateral SC joints.

SC Joints – RAO/LAO

10-15° oblique; CR T2-T3; shows downside SC joint.

Abdomen – AP Supine (KUB)

CR iliac crest; diaphragm to symphysis pubis.

Abdomen – Upright

CR 2″ above crest; demonstrates free air under diaphragm.

Lateral Decubitus Abdomen

Left side down; CR crest; free intraperitoneal air & fluid levels.

Esophagus – RAO

35-40° RAO; CR 2-3″ below jugular notch; esophagus between spine & heart.

Upper GI – RAO

40-70° RAO; CR L1 halfway between spine & left lateral border; barium in pylorus, air in fundus.

Upper GI – LPO

30-60° LPO; CR L1 midway MSP & left rib margin; barium in fundus.

Upper GI – Right Lateral

CR L1, 1–1.5″ anterior to MCP; retrogastric space & duodenal loop.

Small Bowel Series – PA

Early films CR 2″ above crest, later at crest; follows barium to ileocecal valve.

Contrast Enema – AP Axial Sigmoid

30-40° cephalic; CR 2″ below ASIS; elongates sigmoid colon.

Contrast Enema – PA Axial Sigmoid

30-40° caudal; CR 2″ below PSIS; opens rectosigmoid segments.

Contrast Enema – LPO

35-45° oblique; CR crest & 1″ to elevated side; profiles hepatic flexure.

Contrast Enema – RPO

35-45° oblique; CR crest & 1″ to elevated side; profiles splenic flexure.

Cystogram – AP Axial

10° caudal; CR 2″ above pubic symphysis; contrast-filled bladder elongated.

VCUG – AP (female)

CR symphysis; contrast bladder & urethra during voiding.

VCUG – 30° RPO (male)

CR symphysis; shows urethra & bladder while voiding.

IVU – AP

CR iliac crest; shows kidneys, ureters, bladder through timed images.

IVU – RPO

30° RPO; CR crest; demonstrates left kidney/right ureter.

Fingers – PA

CR PIP; entire phalanx & distal metacarpal.

Finger – Oblique

45° oblique; CR PIP; joint spaces & shafts.

Finger – Lateral

CR PIP; true lateral of phalanges.

Thumb – AP

Hand internally rotated; CR MCP; shows entire thumb & trapezium.

Hand – PA

CR 3rd MCP; entire hand/wrist, 1″ distal forearm.

Hand – Oblique

45° oblique; CR 3rd MCP; midshafts of metacarpals not superimposed.

Hand – Fan Lateral

CR 2nd MCP; phalanges separated; metacarpals superimposed.

Wrist – PA

CR mid-carpals; distal radius/ulna, carpals & proximal metacarpals.

Wrist – PA Oblique

45° oblique; CR mid-carpals; scaphoid & trapezium in profile.