1. RADT 1542 SKULL RADIOGRAPHY
Wynn Harrison, Med, RT(R)(N)

2. What a Bad Day!!!!

3. Section 1: The Cranium New Words:
HEMANGIOMA: tumor containing blood vessels and fibrous tissue
TRAUMATIC PNEUMOCEPHALUS: injury causing gas/air in the extracranial cavity

4. HYDROCEPHALUS: increased cerebrospinal fluid in the ventricles
PAGET’S DISEASE: overproduction of bone
CRANIOTOMY: Incision into the head

5. SUBDURAL HEMATOMA: Blood collected beneath the dura
TERATOMA: Congenital tumor containing 1+ embryonic germ layers (hair/teeth/skin may be present)

6. ENCEPHALITIS: Inflammation of the brain
GLIOMA: Primary tumor of the brain
MENINGIOMA: Slow growing benign tumor in the meninges

7. ACOUSTIC NEUROMA: Benign tumor involving hearing
CRANIO-PHARYNGIOMA: Benign tumor above the sella turcica
CONCUSSION: Impact injury

8. ANENCEPHALUS: Congenital absence of the brain
ACEPHALUS: Absence of head
MICROCEPHALIC: Small head
BURR HOLES: Holes bore into skull for pressure relief

9. Why Dogs Bite Their Owners

10. POSITIONING CONCERNS Some people don’t like to have their face touched
Wash your hands FIRST
CLEAN BUCKY or TABLE (and have them watch you)
Remember body habitus
The body is attached to the head!!!!

11. Lines/Landmarks/Planes
Median saggital
Coronal

12. Composition Composed of 22 Bones Eight Cranial Bones
Fourteen Facial Bones

13. Radiographic Landmarks
Glabella: Triangular area between and slightly superior to the eyebrows and above the bridge of the nose
Nasion: Depression at the bridge of the nose
Junction of the two nasal bones and the frontal bone

14. Radiographic Landmarks
Inner Canthus: Where the eyelids meet near the nose
Outer Canthus: Lateral junction of the eyelids
Acanthion: Midline point at the junction of the upper lip and the nasal septum. Point where the nose and the upper lip meet

15. Radiographic Landmarks
Gonion: Angle of the mandible (Jaw)
Mental Point: A triangular area projects forward as the chin (mentum). The center of the mentum is the mental point

16. Radiographic Landmarks
EAR
Auricle/Pinna: External portion of the ear. Large flap of ear made of cartilage
TEA: Top of the ear attachment. Superior attachment of the auricle. Level of the petrous ridge on each side

17. Radiographic Lines
Radiographic lines are important to skull positioning
Certain lines are formed from anterior structures on the face and connect to the EAM
EAM: External acoustic (auditory) meatus, Opening of the external ear canal

18. Radiographic Landmarks
Eye
Supraorbital Margin (SOML): Superior rim of the bony orbit of the eye
Infraorbital Margin (IOML): Inferior rim of the bony orbit of the eye
Midlateral Orbital Margin: (OML) Portion of the lateral rim near the outer canthus of the eye

19. Radiographic Lines
Orbitomeatal Line (OML): Located between the outer canthus (midlateral orbital margin) and the EAM
Infraorbitomeatal Line (IOML): Formed by connecting the middle of the infraorbital margin to the EAM

20. Radiographic Planes Interpupillary Line (IPL):
A line connecting either the pupils or the outer canthi of the patient’s eyes
The IPL must be exactly perpendicular to the IR in a TRUE LATERAL position

21. Talk about TOO MUCH RAIN~

23. Radiographic Landmark
Inion or EOP:
External occipital protuberance
Rise or bump along the midline of the lower back of the head near the junction of the head and neck
Extension of the IOML posteriorly approximates the location of the inion

24. Radiographic Landmark
Vertex
Top portion of the head

25. Sutures of the Skull
Joints formed between the cranial bones are known as sutures
Fibrous connective tissue hold bones tightly together
Synarthrodial – Don’t permit movement

26. Sutures of the Skull Coronal Suture: Sagittal Suture:
Lambdoidal Suture:
Squamosal Suture:

27. Arthrology Temporomandibular Joint: Only movable joints in the cranium
Formed by the mandibular fossa on each temporal bone with corresponding condyle of the mandible

28. Fontanels Soft spots Present at birth Unossified connective tissue
Where three or more bones ajoin
Six Fontanels
Gradually replaced with bone
Allow for skull compression during birth
Most prominent are the anterior and posterior fontanels
Located on the anterior and posterior ends of the sagittal suture

29. Fontanels
Articulation between the frontal and both parietal bones at the anterior end of the sagittal suture is the bregma
Articulation between the occipital bone and both parietal bones at the posterior end is the lambda
Anterolateral (sphenoid) fontanel is the pterion
Posterolateral fontanel is the asterion

30. Fontanels

31. Fontanels

32. Fontanels

33. Calvarium Skull Cap Composed of four bones Frontal bone
Right Parietal bone
Left Parietal bone
Occipital bone

34. Calvarium

35. Calvarium

36. Cranial Floor Composed of four bones Ethmoid bone Sphenoid bone
Right Temporal bone
Left Temporal bone

37. Cranial Floor

38. Skull Morphology
Mesocephalic: Average shaped head, the petrous ridges lie at a 47 degree angle with the MSP
Brachycephalic: Short, broad, shallow head. Petrous ridges form a 54 degree angle with the MSP
Dolichocephalic: Long, narrow, deep head. Petrous ridges form a 40 degree angle with the MSP

39. Occipital Bone

40. Occipital Bone

41. Sphenoid Bone Location and purpose Midline of cranial floor
Anchor to hold the 8 cranial bones together
Articulates with all cranial bones
Forms the base of skull, small portion of each lateral wall, and posterior wall of each orbit

42. Sphenoid Bone Bat shaped Composition Body Central portion of the bone
Paired lesser wings and greater wings
Pterygoid processes
Body
Central portion of the bone
Between the ethmoid and occipital bones
Anterior surface forms posterior wall of nasal cavity
Body is hollow and enclosed with air – filled sphenoid sinuses

43. Sphenoid Bone Body of sphenoid Sella Turcica
Saddle – shaped depression
Superior surface of the body
Houses pituitary gland
Sella turcica is localized for a radiographic exam by centering ¾ inches anterior and ¾ superior to the EAM on a lateral projection

44. Body of Sphenoid
Dorsum Sellae: is the posterior portion of the sella turcica
Posterior Clinoid Processes: Extend superiorly from the lateral margin of the dorsum sellae
Optic Groove: Depression that runs horizontally across the body
Optic Chiasm: Formed by crossing of the optic nerves, situated in the optic groove

45. Sphenoid Bone Lesser Wings of the Sphenoid
Extends laterally and horizontally across the anterosuperior aspect of the body
Junction at the midline is the sphenoid ridge
Anterior clinoid processes extend from the posterior portion of each lesser wing

46. Sphenoid Bone Greater Wings of Sphenoid Posterior to the lesser wings
Arise from the lateral surfaces of the body and extend outward
Openings on each greater wing serve as passageways for the nerves and blood vessels supplying the orbits and face

47. Sphenoid Bone

48. Sphenoid Bone Pterygoid Processes
Extensions of bone from under the sphenoid bone at the junction of the body and greater wings
Articulates anteriorly with the palatine bone and vomer
Comprised of two plates of bone fused together
Medial plate is called the pterygoid hamulus because it has a small hook – like process

49. Sphenoid Bone

50. Sphenoid Bone

51. Sella Turcica Sphenoid Bone

52. Temporal Bones

53. Temporal Bones Named for the region around the temples Location
Below the parietal bone
Articulates with the greater wing of the sphenoid and the occipital bones
Contains 4 Regions
Squamous
Tympanic
Mastoid
Petrous

54. Temporal Bones

55. Temporal Bones

56. Temporal Bones

57. Group Photo Anyone?

58. AP and PA projections
Petrous pyramids fill the orbit if there is no angulation
Petrous pyramid will lie in lower 1/3 of orbit with 15 degree angulation
if AP is it caudal or cephalic?

59. ROUTINE PROCEDURES AP View
OML and sagittal plane perpendicular to the cassette
Petrous pyramids fill
the orbits

60. AP Axial (Townes) OML = 30 degrees IOML = 37 degrees
Posterior clinoids
HAAS is reverse Townes view

61. PA Skull OML = perpendicular to cassette 0 degree angulation
Petrous pyramids fill the orbits

62. PA Caldwell Patient PA with 12 – 15 degree caudal angulation of CR
CR exits nasion
Petrous pyramids in bottom 1/3 of orbit

63. Lateral Skull Interpupillary line perpendicular to cassette
Midsagittal plane parallel to cassette
(Look at patient body habitus)

64. Submentovertex (SMV) IOML parallel to cassette
Midsagittal plane perpendicular to cassette

65. Positioning Errors
Rotation occurs when the median Saggital plane is not parallel to the film.   

67. Tilt occurs when the interpupilary line is not at 90 to the film

70. Trauma and Pathology

73. Golf club

74. Paget’s Disease

75. Pituitary tumor

76. Film critique

77. Critical thinking