Principles of radiographic interpretations

SeminarPrinciples of radiographic

interpretations

Introduction

• Interpretation: an explanations• Radiographic interpretation is an explanation

of what is viewed on dental radiograph

• Diagnosis: the identification of a disease by examination or analysis.

Aim:

• systematic method of image analysis

ACQUIRING APPROPRIATE DIAGNOSTIC IMAGES• Quality of the Diagnostic Image• Number and Type of Available Images

• VIEWING CONDITIONS:.Ambient light in the viewing room should be reduced..Intraoral radiographs should be mounted in a film holder..Light from the view box should be of equal intensity across

the viewing surface..The size of the view box should accommodate the size of the

film. If the viewing area is larger than the film, an opaque mask should be used to eliminate all light from around the periphery of the film. This mask can be fabricated from a sheet of opaque material cut to fit the entire view box, leaving an opening for one film.

.An intense light source is essential for evaluating dark regions of the film.

.A magnifying glass allows detailed examination of small regions of the film.

A. Wardray viewing box incorporating an additional central bright-light source for viewing over-exposed dark films.

B. The SDI X-ray reader — an extraneous light excluding intraoral film viewer with built-in magnification.

Image analysis• INTRAORAL IMAGES1. IOPA before bitewing2. Rt. Maxilla lft. Maxilla lft. Mandible rt.

Mandible3. Identify the anatomic structure, examine the

bone & character of the trabecular bone. 4. Compare the same area on adjacent and

corresponding areas of other side.

• 2nd visual circuit1. Examining the ht. and cortication of alveolar

bone relative to teeth.2. Examine alveolar bone for extent and

severity of bone loss3. Areas of erosion; difference in trabeculae

pattern

• 3rd visual circuit1. dentition and associated structures2. Each tooth in sequence, using all available

images3. Examine PDL space & lamina dura of each

tooth.

EXTRAORAL RADIOGRAPHY• Analysis of Intraosseous Lesions1. picture matching, or "Aunt Minnie,"method2. step-by-step analysis

step-by-step analysis

STEP 1: LOCALIZE THE ABNORMALITY

location

localizedunilateral

bilateral

generalized Metabolic/ endocrinal

cherubism

• Position in the jaws Soft tissue

Within jaws• Odontogenic originCoronal to tooth• Odontogenic originAbove IAC• Neural or vascular originWithin IAC• Not of odontogenic originBelow IAC• Cartilagenous or osteochondromasCondylar region

Specific epicenters

CGCG •Mandible- anterior to 1st molar•Maxilla- anterior to cuspid

Osteomyelitis •Mandible more common

Periapical cemental dysplasia

•Periapical region of teeth

• Single or multifocal periapical cementa! dysplasia, odontogenic keratocysts, metastatic lesions, multiple

myeloma, leukemic infiltrates

• Size- may aid in the differential diagnosis

STEP 2: ASSESS THE PERIPHERY AND SHAPEWell defined

borders

Punched out

sclerotic margin

radiopaque lesion with radiolucent

margins

corticated margin

Ill defined borders

blending border

invasive border/ p ermeative

• Shape

Circular/ hydraulic cyst

Scalloped/ multilocular

Cyst, cystlike lesions, tumors

STEP 3: ANALYZE THE INTERNAL STRUCTUREradiolucent

mixed

radiopaque

Radiolucent lesions:Unilocular- eriapical cyst, granuloma,, abscess, PA cemental dysplasia.

Multilocular- OKC, CGCG, botryoid odntogenic cyst, aneursymal bone cyst,cherubism

Moth eaten - osteomyelitis, osteosarcoma, lymphoma,multiple myeloma

radiopaque lesions:Focal opacity- PA cemental dysplasia, condensing osteitis,sclerotic bone

Target lesions- benign cementoblastoma, complex odontome

Multifocal confluent- osteitis deformans, florid osseous dysplasia

Mixed- AOT, CEOT, compound odontome, KCOT, ossifying fibroma

Irregular- osteosarcoma, chondrosarcomaGround glass- FD, ostetis deformans, osteopetrosis, hyperthyroidism

STEP 4: ANALYZE THE EFFECTS OF THELESION ON SURROUNDING STRUCTURES

•stimulate bone resorption or formation.Inflammatory

lesion

•slowly creates its own space by displacing teeth and other surrounding structuresspace-

occupying

Epicentre above the crown

Apical displacement of tooth eg; follicular cyst, odontomas

Epicentre in ramus push teeth in an anterior direction eg; cherubism

Papilla of developing teeth

push the developing tooth in a coronal direction eg; lymphoma, leukemia, Langerhans‘ cell histiocytosis

Widening of the periodontal membrane space

Malignant lesions; an irregular widening and destruction of the lamina dura

Resorption of teethchronic or slowly growing process; more commonly related to benign processes

Presence of reactive bone at periphery

slow, benign growth and possibly the ability to stimulate osteoblastic activity in the surrounding bone

IAN canal superior displacement Fibrous dysplasia

IAN canal widening with cortical boundary

benign lesion of vascular or neural origin

IAN canal widening with cortical destruction

malignant neoplasm growing down the length of the canal

•Periosteal new bone formationSlow growing lesion

•Missing of cortical plateRapidly growing lesions

•Lift the periosteum•Recurrence cause onion skin

patternInflammatory lesion with exudation

STEP 5: FORMULATE A RADIOGRAPHICINTERPRETATION

Decision 1

Decision 2

Decision 3

Systematic approach

• The entire radiograph• Specific lesions

The entire radiograph

Specific lesions

A systematic description of a lesion should include its:• Site or anatomical position• Size• Shape• Outline/edge or periphery• Relative radiodensity and internal structure• Effect on adjacent surrounding structures• Time present, if known.

references

• White & Pharoh Oral Radiology,4th Edition• White & Pharoh Oral Radiology, 5th Edition• Eric Whaites ; Essentials Of Dental

Radiography & Radiology, 3rd Edition• Karjodhkar; Textbook Of Dental & Maxillofacial

Radiology 2nd Edition• Dental Radiography Principles And

Techniques; Haring & Howerton, 3rd Edition