Principles of Radiographic Interpretation L8

Principles of Principles of Radiographic Radiographic InterpretationInterpretation

Prof. Hossam KandilProf. Hossam Kandil Oral and Maxillofacial RadiologyOral and Maxillofacial Radiology

Cairo UniversityCairo University

Principles of Principles of Radiographic Radiographic InterpretationInterpretation

Chapter 15 (Pages 281-296)

Objective of this topicObjective of this topic

To provide step by step, analytic To provide step by step, analytic process that can be applied to the process that can be applied to the interpretation of diagnostic images.interpretation of diagnostic images.

However, reading this topic will not However, reading this topic will not immediately give the ability to immediately give the ability to interpret radiographic films correctly; interpret radiographic films correctly; rather, it will equip the reader with a rather, it will equip the reader with a systematic method of image analysis. systematic method of image analysis. Proficiency comes only with practiceProficiency comes only with practice

Acquiring Appropriate Acquiring Appropriate Diagnostic ImagesDiagnostic Images

* Quality of the diagnostic image* Quality of the diagnostic image Elongated Length of a root Elongated Length of a root

canalcanal

Density and contrast Density and contrast osteoporosis in an overexposed osteoporosis in an overexposed images can not be seenimages can not be seen

Acquiring Appropriate Acquiring Appropriate Diagnostic Images (Cont.)Diagnostic Images (Cont.)

Number and type of available Number and type of available images:images:

- Caution should be exercised in - Caution should be exercised in attempting to make an attempting to make an interpretation based on a single film, interpretation based on a single film, especially if the only film is a especially if the only film is a panoramic view.panoramic view.

- Periapical and bitwing films often - Periapical and bitwing films often can be supplemented.can be supplemented.

Acquiring Appropriate Acquiring Appropriate Diagnostic Images (Cont.)Diagnostic Images (Cont.)

Viewing conditionsViewing conditions

- Ambient (Surrounding) light in the - Ambient (Surrounding) light in the viewing room should be reduced.viewing room should be reduced.

- Films should be mounted in a film holder.- Films should be mounted in a film holder.

- Light from viewing box should be equally - Light from viewing box should be equally distributed.distributed.

- An intense light is used for dark areas.- An intense light is used for dark areas.

- Magnifying lens for detailed examination.- Magnifying lens for detailed examination.

Image AnalysisImage AnalysisSystematic Radiographic Systematic Radiographic

ExaminationExamination Intra-Oral Images:Intra-Oral Images:

- It is most important for the - It is most important for the practitioner to develop a particular practitioner to develop a particular method and to use it regularly.method and to use it regularly.

- Examine periapical before bitewing - Examine periapical before bitewing radiographs.radiographs.

- Starting in the right maxilla to the - Starting in the right maxilla to the left and then dropping down in the left and then dropping down in the left mandible to the right.left mandible to the right.

Systematic Radiographic Systematic Radiographic Examination (Cont.)Examination (Cont.)

1- Concentrate on 1- Concentrate on one anatomic one anatomic structurestructure at a time. at a time.

* Examine the bone, identify all * Examine the bone, identify all anatomic landmarks for the region. anatomic landmarks for the region. eg, maxillary sinus, tuberosity and eg, maxillary sinus, tuberosity and zygomatic bone for maxillary zygomatic bone for maxillary posterior area. Compare both sides.posterior area. Compare both sides.

* Density and size of the * Density and size of the trabecular bone.trabecular bone.


2- Next, Make a second circuit through 2- Next, Make a second circuit through all the images all the images examining,examining,

- - Hight of the alveolar processHight of the alveolar process..( Active or past periodontal disease, any ( Active or past periodontal disease, any areas of erosion of the alveolar crest areas of erosion of the alveolar crest and thickness of the ovelying mucosa- and thickness of the ovelying mucosa- Carcinomas-)Carcinomas-)

- Examine the - Examine the trabecular patterntrabecular pattern of the alveolar process.of the alveolar process.


3- Finally, make a third visual circuit, examining the 3- Finally, make a third visual circuit, examining the dentition and associated structures.dentition and associated structures.- Count the teeth.- Count the teeth.- Examine the crown for normal development of the - Examine the crown for normal development of the enamel for caries, especially interproximal below the enamel for caries, especially interproximal below the contact area.contact area.- Recurrent caries.- Recurrent caries.- Examine the pulp chamber for size and contents.- Examine the pulp chamber for size and contents.- Roots for shape and form.- Roots for shape and form.- width of the PDL.- width of the PDL.- The lamina dura.- The lamina dura.

N.B. The most common abnormalities found in the bone N.B. The most common abnormalities found in the bone are radiolucent or radiopaque lesions at the apices of are radiolucent or radiopaque lesions at the apices of teeth.teeth.


Extra-Oral Radiographs:Extra-Oral Radiographs:

The most commonly used EO The most commonly used EO radiographs are panoramic, radiographs are panoramic,

cephalometric and cephalometric and temporomandibular views.temporomandibular views.

The same general principles of The same general principles of thorough, systematic coverage thorough, systematic coverage should be usedshould be used

Systematic Radiographic Systematic Radiographic Examination(Cont.)Examination(Cont.)

When an When an intraosseous lesionintraosseous lesion is is identified, the following five steps identified, the following five steps should be used to analyze the lesion should be used to analyze the lesion as fully as possible.as fully as possible. Localize the abnormality.Localize the abnormality. Assess the periphery and shape.Assess the periphery and shape. Analyze the internal structure.Analyze the internal structure. Analyze the effects of the lesion on Analyze the effects of the lesion on

surrounding structures.surrounding structures. Formulate a radiographic interpretation.Formulate a radiographic interpretation.

Analysis of intraosseous Analysis of intraosseous lesionslesions

Two basic approaches can be used:Two basic approaches can be used:

1- Picture matching 1- Picture matching “Aunt Minnie”:“Aunt Minnie”:

Trying to match the radiographic image Trying to match the radiographic image with a mental picture or with an image in a with a mental picture or with an image in a textbook.textbook.

2- A 2- A step by step analysisstep by step analysis of all the of all the radiographic characteristics of the radiographic characteristics of the abnormality and production of a abnormality and production of a radiographic interpretation based on these radiographic interpretation based on these findings. findings. Preferred methodPreferred method..

Aunt MinnieAunt Minnie

Periapical Cemental Dysplasia(PCDs)

PCD left after extraction(Not applied)PCD left after extraction(Not applied)


PCD left after extraction(Not applied)


PCD left after extraction(Not applied)

Step 1- Localize the Step 1- Localize the AbnormalityAbnormality

Localized or Generalized.Localized or Generalized. Position in the Jaws.Position in the Jaws. Single or Multifocal.Single or Multifocal. Size.Size.

Localized or GeneralizedLocalized or Generalized

Try to describe the anatomic Try to describe the anatomic location and limits of the location and limits of the abnormality.abnormality.

- Some lesions are localized to a - Some lesions are localized to a specific region.specific region.

- It may be unilateral or bilateral- It may be unilateral or bilateral

May be it is a normal anatomy,submandibular gland fossa or itcan be a disease like paget’s disease of bone

Fibrous dysplasia

CherubismCherubism

Bilateral, manifesting in both the left and right mandibular ramiBilateral, manifesting in both the left and right mandibular ramiBilateral, manifesting in both the left and right mandibular rami

Localized or Generalized Localized or Generalized (Cont.)(Cont.)

Generalized:Generalized:

If an abnormal appearance affects all the If an abnormal appearance affects all the osseous structures of the maxillofacial osseous structures of the maxillofacial region, generalized conditions such as region, generalized conditions such as metabolic or endocrine abnormalities of metabolic or endocrine abnormalities of bone are considered.bone are considered.

Position in the JawsPosition in the Jaws

Is the abnormality in soft tissue or is Is the abnormality in soft tissue or is it contained within the jaws?it contained within the jaws?

When the lesion is in the bone, the When the lesion is in the bone, the point of origin or the epicenter can point of origin or the epicenter can be estimated.be estimated.

The point of origin may indicate the The point of origin may indicate the tissue types that compose the tissue types that compose the abnormality.abnormality.

Position in the Jaws Position in the Jaws (Cont.)(Cont.)

Examples:Examples:- The epicenter is coronal to a tooth or above - The epicenter is coronal to a tooth or above the inferior alveolar canal(IAC)the inferior alveolar canal(IAC)Odontogenic in originOdontogenic in origin- The epicenter is below the IAC it is - The epicenter is below the IAC it is unlikely to be odontogenic in origin.unlikely to be odontogenic in origin.- Originates with the IAC the tissue of - Originates with the IAC the tissue of origin probably is neural or vascular in natureorigin probably is neural or vascular in nature- If the epicenter is within the maxillary - If the epicenter is within the maxillary antrum the lesion is non-odontogenic in antrum the lesion is non-odontogenic in originorigin

Epicenter is coronal

Epicenter is above the IAC

Epicenter is below the IAC Epicenter within the IACEpicenter within the sinus

Position in the Jaws Position in the Jaws (Cont.)(Cont.)

Particular lesions tend to be found Particular lesions tend to be found in specific locationsin specific locations- The epicenters of - The epicenters of central giant cell central giant cell granulomasgranulomas commonly are located commonly are located anterior to the first molars in the anterior to the first molars in the mandible and anterior to the cuspid in mandible and anterior to the cuspid in the maxilla.the maxilla.- - Peripaical cemental dysplasiaPeripaical cemental dysplasia

(PCD) occurs in the periapical region (PCD) occurs in the periapical region of lower anterior teeth.of lower anterior teeth.

Single or MultifocalSingle or Multifocal

MultifocalMultifocal (the list is short) (the list is short)

- PCDs- PCDs

- Odontogenic Keratocysts (OKCs)- Odontogenic Keratocysts (OKCs)

- Metastaic lesions.- Metastaic lesions.

- Multiple myeloma.- Multiple myeloma.

- Leukemic infiltrates.- Leukemic infiltrates.

SizeSize

There are very few size restrictions There are very few size restrictions for a particulate lesion. But the size for a particulate lesion. But the size may aid in DD.may aid in DD.

A dentigerous cyst is often larger A dentigerous cyst is often larger than a hyperplastic follicle.than a hyperplastic follicle.

Step 2- Assess the Step 2- Assess the Periphery and ShapePeriphery and Shape

Periphery of the lesion:Periphery of the lesion:

Well-definedWell-defined Ill-Ill-defineddefinedIs one in which most

of the periphery is well defined

Difficult to draw an exact delineation around the periphery

Periphery of the lesion:Periphery of the lesion:SubcategoriesSubcategories

Well Defined BordersWell Defined Borders- Punched out border:Punched out border: A A

sharp boundary in which no sharp boundary in which no bone reaction is apperant bone reaction is apperant immediately adjacent to the immediately adjacent to the abnormality. eg Multiple abnormality. eg Multiple myeloma.myeloma.

- A Corticated margin:A Corticated margin: Thin Thin fairly uniform radiopaque fairly uniform radiopaque line of reactive bone at the line of reactive bone at the periphery of a lesion.eg periphery of a lesion.eg cystscysts

- A Sclerotic margin:A Sclerotic margin: Wide Wide radiopaque border of radiopaque border of reactive bone that usually reactive bone that usually not uniform in width.eg not uniform in width.eg PCDsPCDs

- A RO lesion may have a A RO lesion may have a soft tissue capsulesoft tissue capsule which which is indicated by the presence is indicated by the presence of radiolucent line at the of radiolucent line at the periphery.eg Odontomasperiphery.eg Odontomas

Ill Defined BordersIll Defined Borders- A blending borderA blending border is is

ill-defined because of ill-defined because of the gradual transition the gradual transition between normal –between normal –appearing bone appearing bone trabeculae and the trabeculae and the abnormal-appearing abnormal-appearing trabeculae of the lesion. trabeculae of the lesion. eg. Sclerosing osteitis eg. Sclerosing osteitis and fibrous dysplasia.and fibrous dysplasia.

- An invasive borderAn invasive border usually is associated usually is associated with rapid growth.eg. with rapid growth.eg. Malignant lesionsMalignant lesions

- Enlargement of the Enlargement of the marrow spacesmarrow spaces at the at the periphery eg. Malignant periphery eg. Malignant lymphomalymphoma

Examples (Well-defined)Examples (Well-defined)

Punched out border. Corticated Margin

Sclerotic Margin Radiolucent Periphery

Examples (Ill-Defined)Examples (Ill-Defined)

Sclerosing osteitis

Invasive Margin (SCC of Ant Maxilla)

Enlargement of small marrow spaces

Lymphoma

Step 2- Assess the Step 2- Assess the Periphery and Shape (Con.)Periphery and Shape (Con.)

Shape:Shape:

The lesion may have a particular The lesion may have a particular shape or it may be irregular.shape or it may be irregular.

- A circular or fluid filled shape is a - A circular or fluid filled shape is a characteristic of a cyst.characteristic of a cyst.

- A scalloped shape (reflects the - A scalloped shape (reflects the mechanism of growth). May be seen mechanism of growth). May be seen in cysts (OKCs), cyst like lesions in cysts (OKCs), cyst like lesions (simple bone cyst) and some tumors.(simple bone cyst) and some tumors.

ShapeShape

Inflated Baloon (Circular)

Scalloped (OKCs)

Step 3- Analyze the Internal Step 3- Analyze the Internal StructureStructure

Classified into one of three basic Classified into one of three basic categories:categories:- Totally Radiolucent. (Common in cysts)- Totally Radiolucent. (Common in cysts)- Totally Radiopaque. (Common in - Totally Radiopaque. (Common in osteomas)osteomas)- Mixed Radiolcent and Radiopaque- Mixed Radiolcent and Radiopaque

Is seen as the presence of calcified Is seen as the presence of calcified structures against a radiolucent structures against a radiolucent background. eg. Bone, enamel background. eg. Bone, enamel (examine (examine the shape, size and pattern of this calcified the shape, size and pattern of this calcified structures).structures).

List of the most RL to the List of the most RL to the most RO material seen in most RO material seen in

plain radiographsplain radiographs Air, fat and gasAir, fat and gas FluidFluid Soft tissueSoft tissue Bone marrowBone marrow Trabecular boneTrabecular bone Cortical bone and dentineCortical bone and dentine EnamelEnamel MetalMetalN.B. A large amount of cortical bone N.B. A large amount of cortical bone

may be as radiopaque as enamel.may be as radiopaque as enamel.

List of a few possible List of a few possible internal structures in mixed internal structures in mixed

density lesionsdensity lesions Abnormal BoneAbnormal Bone

Differ in number, length, width and Differ in number, length, width and orientation of the trabeculae.orientation of the trabeculae.

e.g.: Fibrous dysplasiae.g.: Fibrous dysplasia

Greater in number, shorter and not Greater in number, shorter and not aligned in response to applied stress to aligned in response to applied stress to the bone but are randomly oriented the bone but are randomly oriented giving the pattern described as giving the pattern described as orange orange peel or ground-glass appearancepeel or ground-glass appearance

List of a few possible internal List of a few possible internal structures in mixed density structures in mixed density

lesions (Cont.)lesions (Cont.) Septa:Septa:

Represent residual bone that has been Represent residual bone that has been organized into long strands or walls.organized into long strands or walls.

Multilocular:Multilocular:If these septa divide the internal structure If these septa divide the internal structure into at least two compartments, the term into at least two compartments, the term multilocularmultilocular is used is used

Unilocular:Unilocular:No septa inside the lesionNo septa inside the lesion


lesions (Cont.)lesions (Cont.) The length, width and orientation of the The length, width and orientation of the

septa can be assessed.septa can be assessed. Curved, coarse septa Curved, coarse septa (Soap bubble (Soap bubble

appaearance)appaearance) e.g. Ameloblastoma and OKC e.g. Ameloblastoma and OKC Tennis racket and granuular Tennis racket and granuular

appaearanceappaearance can be seen in can be seen in

odontogenic myxoma with sharp odontogenic myxoma with sharp

angles septaangles septa Smaller locules, Smaller locules, honey comb termhoney comb term is used is used


lesions (Cont.)lesions (Cont.) Dystrophic Calcification:Dystrophic Calcification:

Occurs in damaged soft tissue.Occurs in damaged soft tissue.e.g. - Calcified lymph nodes (cauliflower-e.g. - Calcified lymph nodes (cauliflower-like like masses in the soft tissue)masses in the soft tissue)

- Chronically inflamed cysts- Chronically inflamed cysts Cementum:Cementum: Homogeneous, dense, Homogeneous, dense,amorphous structure, oval or round in amorphous structure, oval or round in

shape.shape. Tooth Structure:Tooth Structure: Identified by the Identified by the organization into enamel, dentin, and organization into enamel, dentin, and pulp chamberpulp chamber

Step 4 - Effect on adjacent Step 4 - Effect on adjacent structuresstructures

The following The following structure are to be structure are to be checked:checked:

The teeth: there may The teeth: there may be evidence ofbe evidence of

ResorptionResorption DisplacementDisplacement Disrupted development Disrupted development Delayed eruptionDelayed eruption hypercementosishypercementosis

Effect on adjacent Effect on adjacent structuresstructures

•Surrounding bone: Surrounding bone: There may be evidence ofThere may be evidence of::

•Expansion: buccal, lingual, Expansion: buccal, lingual, otherother








Surrounding bone: Surrounding bone:

There may be evidence ofThere may be evidence of::

Displacement of: inferior dental canal, Displacement of: inferior dental canal, mental foramen, antra, lower border of mental foramen, antra, lower border of the mandible, nasal cavity and orbits.the mandible, nasal cavity and orbits.



There may be evidence ofThere may be evidence of:: Ragged destructionRagged destruction Alteration of normal trabecular Alteration of normal trabecular

pattern.pattern.



There may be evidence ofThere may be evidence of:: Subperiosteal new bone formation. Giving Subperiosteal new bone formation. Giving

the appearnce of the appearnce of onion-skin patternonion-skin pattern (mostly in (mostly in inflammatory lesioninflammatory lesion as as osteomyelitis and rarely in some osteomyelitis and rarely in some malignant malignant lesionslesions as leukemia. as leukemia.

Some periosteal reactions are very specific Some periosteal reactions are very specific (New bone formed at (New bone formed at right anglesright angles to the to the outer cortical plate, e.g. Metastatic lesions outer cortical plate, e.g. Metastatic lesions of prostate) or (of prostate) or (Radiating patternRadiating pattern, e.g. , e.g. osteogenic sarcoma) osteogenic sarcoma)

Importance of recognition of Importance of recognition of the effect on adjacent the effect on adjacent

structuresstructures Ab tend to grow and infiltrate in all Ab tend to grow and infiltrate in all

directions.directions.

Keratocyst tend to grow and infiltrate Keratocyst tend to grow and infiltrate through the cancellous bone along the through the cancellous bone along the body of the mandible and produce little body of the mandible and produce little expansion.expansion.

The more dangerous the lesion, the more The more dangerous the lesion, the more damaging and destructive its effect.damaging and destructive its effect.

Step 5- Formulate a Step 5- Formulate a Radiographic Radiographic InterpretationInterpretation

Decision 1-Decision 1- Normal Versus Normal Versus Abnormal.Abnormal.

Decision 2-Decision 2- Developmental Versus Developmental Versus Acquired.Acquired.

Decision 3-Decision 3- Classification. Classification. Decision 4-Decision 4- Ways to Proceed. Ways to Proceed.

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Principles of Radiographic Interpretation L8