1. 如何判讀放射線影像 ? 本課程會讓你們瞭解以下的重點 : 學 習 目 標學 習 目 標 1. Eric Whaites: Essentials of dental radiography & radiology 3rd edition, Chapter 1, 18, 24 p. 3-12; p , p 如何書寫放射線影像報告 ? References 2. http//ddmfr.net 3. Farman AG et al. A sequential approach to radiological interpretation. Dent Maxillofac Radiol 2002;31:
牙 三 Dental Radiography--- Techniques 牙 三 Dental Radiography--- Techniques 牙 四 Dental Radiology--- Interpretation 牙 四 Dental Radiology--- Interpretation Radiology is the use of radiant energy (X ray) in the diagnosis and treatment of disease Only dentist can practice radiology as it involves diagnosis and treatment Radiography is the photographically recording of images of the teeth and surrounding structures with use of X-ray. Can be done by hygienists and assistants
Front view Plan view Radiographs Plaster of Paris Hollow Plastic Metal Wood Objects of same shape, different materials Objects of same shape & materials, different densities Different radiographs Different radiographs Front view Plaster of Paris Ref. 1
Front view Plan view Objects of different shape, same materials Objects of different shape, same materials Plaster of Paris Radiographs Front view Plan view Plaster of Paris Different radiographs Different radiographs Objects of same shape, same materials, different diameter Objects of same shape, same materials, different diameter Increasing intensity Radiographs Burn out Ref. 1
Mass of head in a different position & different shape Similar images Lateral view PA view Similar images Radiodence object What kind of X-ray should be taken? Lateral view Diff er ent images Ref. 1
Over exposure Normal exposure Under exposure With a black surmount With a white surround Increased detail Correct Projection Incorrect vertical angle Elongation Shortening Incorrect horizontal angle Distorted images Ref. 1
Many ships? or Many arches Different views Artifacts Illusion Frog Horse Different views Artifacts Illusion Three views of a house FrontSide Plan Ref. 1Internet data: anonymous,
Measuring the dimensions in cm Describing boundaries (the lesion extends from…..to…..in one dimension and extends from…..to……in the other dimension) Size Site Size Shape Outline Relative density Effects on adjacent surrounding structures Site Ref. 1
Outline * Poorly-defined Well-defined with a corticated margin Well-defined without a corticated margin Poorly-defined Smooth Punched-out Corticated: a thick or thin surrounding RO line Sclerotic: a non-uniform RO boundary Oval Encapsulated Irregular * Well-defined Ref. 1
1.Uniformly RL 2.RL with RO (mixed) 3.RO Relative density Effects on adjacent surrounding structures 1.Bony expansion 1.Tooth displacement 3. Thinning of cortex 2. Downward displacement of inferior alveolar canal Ref. 1
Principles of description & localization of bony lesions affecting the jaws 1Relative radiodensity & internal structure of the lesion 2Size & location of the lesion 3Shape of the lesion 4Borders of the lesion 5Effects on surrounding bone 6Effects on the bony cortex 7Effects on adjacent teeth 8Periosteal reaction Ref. 2
Principles of description & localization of bony lesions affecting the jaws 1.Relative radiodensity and internal structure of the lesion The relative radiolucency or radiopacity of the lesion compared to the surrounding bone. 2 Size and location of the lesion The size and the location of a lesion in relation to the adjacent teeth and anatomic structures provide significant information about the type of the underlying condition.
Principles of description & localization of bony lesions affecting the jaws 3. Shape of the lesion The shape of the lesion can provide information about the degree and the rate of development of the lesion. 4. Borders of the lesion The borders of the lesion provide information about the slow or rapid growing of the pathological condition and may help in many cases to differentiate between benign or malignant lesion.
Principles of description & localization of bony lesions affecting the jaws 5. Effects on surrounding bone Features that should be examined are alterations in the size and distribution of trabeculation, existence or not of sclerotic bone rim. 6. Effects on the bony cortex The effects of the lesion on the bony plates of the jaws (expansion, thinning, erosion, perforation).
Principles of description & localization of bony lesions affecting the jaws 7. Effects on adjacent teeth There may be evidence of: root resorption, displacement, delayed eruption, loss of lamina dura. 8. Periosteal reaction The relation of the lesion to possible periosteal reaction (lamellar, sunburst, onion skin, hair-on- end).
There is a well-defined unilocular round shaped circumcoronal radiolucence with a corticated margin over the submerged tooth 38 extending from left retromolar area down to the mandibular angle and from distal aspect of tooth 37 up to two-third of left ramus area, measuring approximately 3 5 cm in diameter. Question: Please describe the lesion as indicated by yellowish arrow 背 ! 背 ! 背 ! SiteSizeShape OutlineRelative density Effect on adjacent structure Downward displacement Ref. 4
There is a well-defined unilocular round shaped circumcoronal radiolucence with a corticated margin over the well-developed submerged tooth 38 (pushed downward to the inferior cortex) extending from left retromolar area down to the mandibular angle and from distal aspect of tooth 37 up to two-third of the left ramus area, measuring approximately 3 5 cm in diameter. Downward displacement of left inferior alveolar canal and thinning of the left external oblique ridge are also noted SiteSizeShape OutlineRelative density Effect on adjacent structure Ref. 4