16- Fundamentals of interpretation

Question 1

Radiographic interpretation can be defined as what?

Answer 1

The ability to see and understand what is revealed by a radiograph

Question 2

5 Interpretation principles

Answer 2

1. Importance of recognizing normal anatomy
2. Radiographic signs are the same in panoramic, PA’s & CBCTs or any other imaging modality
3. The principle of symmetry
4. Radiographic signs: Terminology and description
5. Categorization of disease and/or abnormalities

Question 3

What is the foundation of radiologic interpretation:

Answer 3

The importance of knowing anatomy

Question 4

6 steps to interpreting a panoramic radiograph

Answer 4

1. First, evaluate image quality: image density, contrast; check for patient positioning errors, asymmetric magnification and/or distortion and artifacts
2. Look at bony anatomy & compare to your mental database of normal
3. Evaluate TMJs, ramus & cervical spine
4. Along the bottom of the image, evaluate the hyoid bone and check for calcified carotid atheromas
5. Then, look at the teeth and alveolar ridges
6. Finally, what was the diagnostic task? Where is the region of interest? Make sure and evaluate that

Question 5

5 Steps to interpreting a FMX

Answer 5

1. First, evaluate image quality: image desnity, contrast; check for horizontal angulation problems, closed contacts, cut off apices, are all the teeth visible???
2. Look at bony anatomy & compare to your mental database of normal
3. Evaluate floor of sinus, alveolar bone, mandibular canal, lamina dura, PDL spaces, trabecular pattern, apical radiolucencies, etc.
4. Finally, check for restoration integrity, margins, caries, calculus, etc.
5. Finally, what was the diagnostic task? Where is the region of interest? Make sure and evaluate that.

Question 6

3 guidelines to viewing sequence of Global and Local

Answer 6

Global: 
1. Assess symmetry of form and density
2. Follow cortical boundaries
3. Count teeth
Local:
1. Assess PDL space and lamina dura
2. Evaluate root form and canal structure
3. Assess crowns for caries or abnormality

Question 7

3 Basic views in CBCT:

Answer 7

1. Sagittal
2. Coronal
3. Axial Maxilla/Mandible

Question 8

DMSLSIE stands for what?

Answer 8

D - Density
M - Margin
S - Size
L - Location 
S - Shape
I - Internal Character
E - Effects of surrounding structures

Question 9

Terminology for Radiolucent lesions:

Answer 9

Corticated Unilocular 
Non-corticated Unilocular
Multilocular 
Multifocal Confluent
Moth-Eaten

Question 10

Terminology for Radiopaque lesions:

Answer 10

Focal Opacity
Target Lesion
Multifocal Confluent 
Irregular, Ill-defined 
Ground Glass
Mixed Density
Soft tissue

Question 11

5 Soft tissue radiopacities:

Answer 11

Calcified Lymph nodes
Sialoliths
Tonsiliths
Phleboliths (calcified blood clots)
Calcified carotid atheromas

Question 12

7 Radiographic signs

Answer 12

1. Radiographic density
2. margin Characteristics
3. Shape
4. Location and distribution
5. Size
6. Internal architecture
7. Effect on surrounding tissue

Question 13

Density: Benign vs Malignant

Answer 13

Benign:

• radiolucent
• Mixed radiolucent-radiopaque
• Septations, loculations

Malignant: Always radiolucent except:

• Metastases (breast cancer, prostate cancer)
• Osteogenic sarcoma

Question 14

Margins tell us what?

Answer 14

A lot about the biology of the lesion and its aggressiveness

Question 15

Margins: Benign vs Malignant

Answer 15

Benign:

• Well-defined (narrow zone of transition)
• Smooth, regular
• Corticated

Malignant:

• Ill-defined (wide zone of transition)
• Ragged
• Moth-eaten

Question 16

Shape: Benign vs Malignant

Answer 16

Benign: Round or oval

Malignant: Irregular

Question 17

Effect on Surrounding tissues (Cortical bone): benign vs malignant

Answer 17

Benign:

• Expansion
• Thinning
• Aggressive benign may erode

Malignant:

• Erosion
• Destruction

Question 18

Effect on Surrounding tissues (Maxillary sinus): Benign vs Malignant

Answer 18

Benign:
- Displacement

Malignant:

• Erosion
• Destruction

Question 19

Effect on Surrounding Tissues (Inferior Alveolar Nerve): Benign vs Malignant

Answer 19

Benign:

• Displacement mandibular canal
• No neuro-sensory deficits

Malignant:

• Invasion and destruction of canal
• Anesthesia, paresthesia

Question 20

Effect on Surrounding tissues (Tooth position): Benign vs Malignant

Answer 20

Benign:

• Displacement
• May prevent eruption

Malignant:
- Floating teeth

Question 21

Effect on Surrounding tissues (Tooth root): Benign vs Malignant

Answer 21

Benign:
- Horizontal or near horizontal

Malignant:

• More variable
• Sometimes no root resorption
• Spiked roots

Question 22

Localized root destruction usually is associated with pressure resorption from what type of lesions?

Answer 22

Slowly growing lesions or benign neoplasms such as ameloblastoma

Question 23

Asymmetric widening of the periodontal ligament space and loss of lamina dura can be a sign of what?

Answer 23

A malignant tumor, such as:

• Osteosarcoma
• Chondrosarcoma
• Lymphoma