3. SELLA TURCICA
• A depression in the base
of the skull where the
pituitary gland is situated.
It was called the sella
turcica (the Turkish
saddle) because of its
resemblance to a saddle
used by the Turks which
had supports in the front
and back.
4.
5.
6. Sella Turcica – Upright/Recumbent
Lateral
IR 8x10 CW
Px Position Upright/recumbent and in lateral position
Part Position Place patient's head in a true lateral position;
position patient's body oblique as needed for
comfort. Align interpupillary line perpendicular
to IR. Align midsagittal plane parallel to IR. Place
IOML perpendicular to front edge of IR.
Ref. Point Center to a point 3/4 inch (2 cm) anterior and
3/4 inch (2cm) superior to the EAM
SID 40 in (100 cm)
7. Sella Turcica – Upright/Recumbent
Lateral
Central Ray Perpendicular to the IR
Respiration Suspend respiration during exposure.
Struc. Shown Sella turcica, anterior and posterior clinoid
processes, dorsum sallae, and clivus are shown.
Eval. Criteria The sella turcica is visualized without rotation or
tilt as indicated by the following:
- Sella turcica and clivus are demonstrated in
profile.
- Anterior and posterior clinoids are
superimposed.
13. Related Terms:
Skull - a framework of bone or cartilage enclosing
the brain of a vertebrae.
Pituitary Adenoma – a benign neoplasm of the
anterior pituitary gland; some contain hormone-
secreting cells but some are not secretory.
14. Sella Turcica – a depression on the upper
surface of the sphenoid bone, lodging the
pituitary gland.
15. Dorsum Sellae - is part of the sphenoid bone
in the skull.
Posterior Clinoid – the sharp superolateral
corners of the dorsum sellae that provide
attachment for connective tissue fibers.
Anterior Clinoid – the medial end of this border
forms this which gives attachment to
tentorium.
Superciliary Arch/Supraorbital Ridge
- refers to a bony ridge located above the eye
sockets of all primates
Foramen Magnum – is a large opening in the
occipital bone of the cranium.
16. Petrous Ridges - is pyramid-shaped and is
wedged in at the base of the skull between the
sphenoid and occipital bones.
Occipital Bone – a saucer-shaped membrane
bone situated at the back and lower part of the
cranium.
18. Remove all metal, plastic, or other
removable objects from the patient's head.
Take radiograph with patient in erect or
supine position.
Patient Position
21. Part Position:
Rest patient's posterior skull against
table/Bucky surface.
Flex neck to bring Infraorbitomeatal Line
(IOML) perpendicular to midline of the grid
or table/Bucky surface.
Respiration
: Suspend respiration during exposure.
22. Collimation:
Collimate to a field size of approximately 4
inches (10 cm) square.
Note:
To obtain sharply detailed image of the
dorsum sellae, use a small focal spot.
23. Central Ray:
Angle CR 37° caudad if dorsum sellae and
posterior clinoid processes are of primary
interest.
Angle CR 30° caudad if anterior clinoids are
of primary interest.
Center at midsagittal plane 1 1/2 inches (4
cm) above supercillary arch. (CR will exit the
foramen magnum.)
Minimum SID is 40 inches
24.
25. Structure Shown:
Dorsum sellae, anterior and posterior clinoid
processes (depending on CR angulation),
foramen magnum, petrous ridges, and
occipital bone are shown.
26. Evaluation Criteria:
Density and contrast are sufficient to
visualized the dorsum sellae to the adjacent
skull structures.
Sharp bony margins indicate no motion.
29. PA Axial Projection: Sella Turcica (Haas
Method)
• IR: 8x10 lengthwise
• Patient Position: Prone; facing
the image receptor
(erect or recumbent)
• Part Position: Rest patient’s
nose and forehead
against IR or table
OML Perpendicular to IR
MSP perpendicular to
midline of IR
• Central Ray: CR 25° cephalad
entering 1 ½ inch
inferior to the inion.
SID is 40 inches (100 cm)
30. PA Axial Projection: Sella Turcica (Haas
Method)
• Respiration: Suspend
• Structure Shown/Evaluation
Criteria:
- The dorsum sellae
centered at radiograph
and posterior clinoid
processes should be
demonstrated within the
shadow of the foramen
magnum.
- No rotation should be
demonstrated
- Symmetrical petrous
pyramids are visualized.
31. Reference:
• Bontrager, K.J. (1993). Textbook of Radiographic
Positioning and Related Anatomy. (3rd ed.) Mosby-
Year Book, Inc. United States of America.
• Carlton, R., Greathouse, J.S., & Adler, A.K. (2013).
Principles of Radiographic Positioning and
Procedures Pocket Guide. (3rd ed.) Cengage
Learning.
33. http://www.anatomyexpert.c
om/app/structure/596/1076/
SELLA TURCICA
• Sella Turcica is a depression in the base of the
skull where the pituitary gland is situated.
• The size of the Sella Turcica
ranges from 4 to 12 mm for
the vertical and from 5 to
16 mm for anteroposterior
dimension.
• Its size and shape develops
during growth.
36. • IR: 8 x 10 inches (20 x 24 cm) Lengthwise
• Patient Position:
Prone or seated erect. Center midsagittal plane
(MSP) of body to table or vertical grid device.
Shoulders should lie in same transverse plane,
with arms positioned for comfort.
• Part Position:
Rest patient’s head against the Table/Bucky with
the forehead and nose touching the surface. Adjust
the head so that the OML is perpendicular to the
IR.
37. • Central Ray:
Direct the central ray to the glabella at an angle of
10 degrees cephalad. Adjust the position of the
film so that the midpoint will coincide with the
central ray.
• Minimum SID:
40 inches
• Patient Instruction:
Suspend respiration and movement for exposure.
38. Frank, E., & Ballinger, P. (2003). Merrill's atlas of radiographic positioning & radiologic
procedures (10th ed.). St. Louis, Mo.: Mosby.
39. • Structures Demonstrated:
1. Dorsum sellae 4. Frontal
bone
2. Tuberculum sellae 5. Ethmoid sinuses
3. Anterior and posterior clinoid processes
Merrill, V. & Ballinger, P. (1982). Merrill's Atlas of radiographic positions and radiologic
procedures. St. Louis: Mosby.
40. Frank, E., & Ballinger, P. (2003). Merrill's atlas of
radiographic positioning & radiologic procedures (10th ed.).
St. Louis, Mo.: Mosby.
42. • Evaluation Criteria:
1. Cranium should be seen without rotation
2. Structures should be visualized through frontal
bone
3. Petrosae should appear
symmetrical
4. Evidence of collimation
should be observed
5. Correct patient
identification and side
marker should be
present on finished
radiograph Dowd, S. & Wilson, B. (1995). Encyclopedia
of radiographic positioning. Philadelphia:
Saunders.
43. References:
• Dowd, S. & Wilson, B. (1995). Encyclopedia of radiographic
positioning. Philadelphia: Saunders.
• Frank, E., & Ballinger, P. (2003). Merrill's atlas of radiographic
positioning & radiologic procedures (10th ed.). St. Louis, Mo.:
Mosby.
• Mancall, Elliott L.; Brock, David G., eds. (2011). "Cranial
Fossae". Gray's Clinical Anatomy. Elsevier Health Sciences.
p. 154.
• Merrill, V. & Ballinger, P. (1982). Merrill's Atlas of radiographic
positions and radiologic procedures. St. Louis: Mosby.
Fig. 2 Different morphological type of sella turcica: a) normal sella turcica, b) oblique anterior wall, c) double contour of floor, d) sella turcica bridge, e) irregular dorsum sella, f) pyramidal shape of dorsum sella.
Sella turcica is from the Latin words sella, meaning seat, and turcica, meaning Turkish.
Based on this formation’s resemblance to a type of saddle with a broad seat, high pommel and cantle, the term was introduced to the anatomical nomenclature (method of naming anatomical structures) by the Flemish (NORTHERN BELGIUM) anatomist, physician, and botanist Adrianus Spigelius (1578−1625) in De Humani Corporis Fabrica (1627) / On the Fabric of the Human Body
The erect position allows the patient to be positioned quickly and easily.
The dorsum and tuberculum sellae and the posterior and anterior clinoid processes are projected through the frontal bone just above the ethmoid sinuses.
“Note: To obtain sharply detailed image of the dorsum sallae, use of a small focal spot and chose collimation is essential.”
NOTE TO SELF: Take note of the meaning of the structures demonstrated and explain it to the class.
FACT: The sella turcica is usually larger in females than in males – in females the superior border tends to be convex, whereas in males it is usually concave.