Radiographic Positioning And Related Anatomy Ch. 12 Sect. C

Front 1

List the three classifications of the skull; then match them with the correct shape description listed on the right
Classification
A. Mesocephalic
B. Brachycephalic
C. Dolichocephalic

Shape Description
a. Width less than 75% of length
b. Width 80% or more than length
c. Width between 75% and 80% of length

Back 1

A = c
B = b
C = a

Front 2

Central ray angles and degree of rotation stated for basic skull positions are based on the ___________ (average) skull, which has an angle of ______________ degrees between midsagittal plane and the long axis of the petrous bone.

Back 2

Mesocephalic, 47

Front 3

The long, narrow-shaped skull has an angle of approximately _______ between the midsagittal plane and the long axis of the petrous bone.

Back 3

40 degrees

Front 4

T/F. Two older terms for the orbitomeatal line (OML) are Reid's base line and the anthropologic base line.

Back 4

Inframeatal line

Front 5

There is a ___________ difference between the orbitomeatal and infraorbitomeatal lines, and __________ between the orbitomeatal and glabellomeatal lines.

Back 5

7-8 degree, 70 - 80 degrees

Front 6

Match each of the following cranial landmarks and positioning lines with the correct definition.
1. Lateral junction of the eyelid
2. Posterior angle of the jaw
3. A line between the infraorbital margin and EAM
4. Corresponds to the highest "nuchal" line of the occiptal bone
5. A line between the glabella and alveolar process of the maxilla.
6. A line between the mental point and the EAM
7. Located at the junction of the two nasal bones and the frontal bone
8. The small cartilaginous flap covering the ear opening
9. Corresponds to the highest level of the facial bone mass
10. A line between the midlateral orbital margin and the EAM
11. The center point of the EAM
12. A positioning line that is primarily used for the modifed Water's projection.
13. A line used in positioning to ensure that the skull is in a true lateral position.
14. Corresponds to the level of the petrous ridge
15. A smooth, slightly depressed area between the eyebrows.

a. TEA
b. Supraorbital groove
c. Interpupillary line
d. Nasion
e. Gonion
f. Tragus
g. Outer canthus
h. Glabelloalveolar line
i. OML
j. Infraorbitomeatal Line (IOML)
k. Mentomeatal Line
l. Lips-meatal line
m. Glabella
n. Inion
o. Auricular Point

Back 6

1. g
2. e
3. j
4. n
5. h
6. k
7. d
8. f
9. b
10. i
11. o
12. l
13. c
14. a
15. m

Front 7

What is the average kV range for the skull radiograph?

Back 7

70-85 kV

Front 8

T/F. According to HEW Report 76-8031, the patient receives no detectable gonadal exposure during skull projections.

Back 8

True

Front 9

T/F. The AP axial (Towne) skull results in about 10 times more dose to the thyroid than a PA axial (Haas) projections.

Back 9

True

Front 10

The thyroid dose for a submentovertex (SMV) projection of the skull is in the ________ range (which is the highest thyroid dose of any skull projection).

Back 10

C. 200 to 300 mrad

Front 11

List the five most common errors made during skull radiography.
A.
B.
C.
D.
E.

Back 11

A. Rotation
B. Tilt.
C. Excessive Flexion
D. Excessive Extension
E. Incorrect CR angulation

Front 12

Of the five causes listed in the previous question, which two are the most common?
A.
B.

Back 12

A. Rotation
B. Tilt

Front 13

T/F. Adults with osteoporosis may require 25% to 30% reduction in mAs during skull projections

Back 13

True

Front 14

Which one of the following imaging modalities is the most common neuroimaging procedure performed for the cranium?

Back 14

CT

Front 15

Which of the following imaging modalities is usually performed on neonates with a possible intracranial hemorrhage?

Back 15

Ultrasound

Front 16

Which of the following imaging modalities is most commonly performed to evaluate patients for Alzheimer disease?

Back 16

Nuc Med

Front 17

Match each of the following pathological indications to the correct definition or statement.

A. Fracture that may produce an air-fluid level in the sphenoid sinus
B. Destructive lesion with irregular margins
C. Also called a "ping-pong" fracture
D. Proliferative bony lesion of increased density
E. A tumor that may produce erosion of the sella turcica
F. Also known as osteoitis deformans
G. A bone tumor that originates in the bone marrow

1. Osteoblastic neoplasm
2. Pituitary adenoma
3. Basal Skull fracture
4. Paget's disease
5. Osteolytic Neoplasm
6. Depressed skull fracture
7. Multiple myeloma

Back 17

A. 3
B. 5
C. 6
D. 1
E. 2
F. 4
G. 7

Front 18

Which one of the following pathologic indications may require an increase in manual exposure factors?

Back 18

Paget's Disease

Front 19

Which cranial bone is best demonstrated with an AP Axial (Towne Method) projection of the skull?

Back 19

Occipital

Front 20

When using a 30 degree caudad angle for the AP axial (Towne Method) projection of the skull, which positioning line should be perpendicular to the image receptor?

Back 20

OML

Front 21

A property positioned AP axial (Towne method) projection should place the dorsum sellae into the middle aspect of the:

Back 21

Foraemen magnum

Front 22

A lack of symmetry of the petrous ridges indicates which of the following problems with a radiograph of an AP axial projection?

Back 22

Rotation

Front 23

If the patient can't flex the head adequately for the AP axial (Towne method) projection, the technologist could place the ____________ perpendicular to the image receptor and angle the central ray ______ degrees caudad.

Back 23

IOML, 37

Front 24

What evidence on an AP axial (Towne method) radiograph indicates whether the correct central ray angle and correct head flexion were used?

Back 24

Dorsum sellae and posterior clinoids in foramen magnum

Front 25

What CR angle should be used for the PA axial (Haas method) projection for the cranium?

Back 25

25 degree cephalad

Front 26

Where is the CR centered for a lateral projection of the skull?

Back 26

2 inches above the EAM

Front 27

Which specific positioning error is present if the mandibular rami are not superimposed on a lateral skull radiograph?

Back 27

Rotation

Front 28

Where will the petrous ridges be projected with a 15 degree PA axial (Caldwell) projection of the cranium?

Back 28

Lower 1/3 of orbits

Front 29

Which specific positioning error is present if the petrous ridges are projected higher in the orbits than expected for a 15 degree PA axial projection?

Back 29

Excessive flexion or insufficient CR angle

Front 30

Which projection of the cranium produces an image of the frontal bone with little or no distortion?

Back 30

0 degree PA

Front 31

With a possible trauma patient, what must be determined before performing the SMV projection of the skull?

Back 31

R/O cervical fractures or subluxation

Front 32

Where is the CR centered for a lateral projection of the sella turcica?

Back 32

3/4 inch anterior and 3/4 inch superior to EAM

Front 33

Which skull positioning line is placed parallel to the plane of the IR for the SMV projection?

Back 33

IOML

Front 34

Which one of the following AP axial projections for Sella turcica best visualizes the anterior clinoid processes?

Back 34

30 degrees caudal to IOML

Front 35

Which one of the following projections best demonstrates the sella turcica in profile?

Back 35

Lateral

Front 36

Which one of the following projections best demonstrates the foramen rotundum?

Back 36

25 to 30 degree PA axial

Front 37

Which one of the following projections best demonstrates the clivus in profile?

Back 37

Lateral

Front 38

Where does the CR exit for a PA axial (Haas method) projection of the skull?

Back 38

1 1/2 inches (4cm) superior to the nasion

Front 39

What type of CR angle is used with the AP axial projection for sella turcica if the dorsum sellae and posterior clinoid processes are of primary interest?

Back 39

37 degree caudad

Front 40

Which imaging modality is best to differentiate between an epidural and subdural hemorrhage?

Back 40

CT