RADT 1542 SKULL RADIOGRAPHY

1. RADT 1542SKULL 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. Median saggital Coronal Lines/Landmarks/Planes

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. 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 Fontanels

29. 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 Fontanels

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. Bat shaped Composition Body 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 Sphenoid Bone

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 ClinoidProcesses: 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