Panoramic Radiology What's Wrong Here? - Columbia CTL

Panoramic RadiologyWhat’s wrong here?Steven R. Singer, DDSsrs2@columbia.eduPanoramaAn unobstructed viewin every direction.HistoryTomography To view a “slice” of astructure Useful for examiningcentrally locatedstructures whereoverlying structuresobscure conventionalimages Panoramicradiographs are curvedsurface tomogramsHistory1

HistoryTodayTodayIndications for PanoramicRadiography Evaluation of traumaThird molarsLarge lesionsGeneralized diseaseInability to tolerate intraoral filmsAssessment for surgical proceduresAdvantagesDisadvantages Well-tolerated by patients Minimal time to expose when compared tointraoral radiographs Broad anatomical coverage Relatively low patient dose Useful for patient education (although neverexposed only for that purpose!) Resolution is not as good as intraoral films.This results in decreased detail Only objects in focal trough are seen clearly Distortion of image––––Overlapped teethMagnificationMinificationObjects of interest outside of focal trough2

Panoramic ImagesImage LayerPanoramic CollimationImage Layer Volume of tissue seen clearly on tomographicimage Three dimensional curved volume Called the Focal Trough in panoramic radiology Can vary in thickness Usually pre-set on panoramic machines withvariable settings for different size dental archesImage LayerImage Layer Patient must be positioned precisely in themachine, and machine set correctly so thatthe dental arches are in the focal trough Positioning may be difficult due to swelling,pain, and asymmetries3

Image LayerImage LayerImage LayerImage LayerImage LayerCenter ofRotation4

Center of RotationSplit image – 1 Stationary center of rotation Unfortunately, the dental arches are not truearcs. Therefore, several centers of rotationare necessary to maintain the dental archesin the focal trough as the machine turnsaround the patient.The Original SS WhitePanorex MachineContinuous Image- 3 FixedCenters of RotationContinuous Image - SlidingBeam TransitionContinuous Image –Combination of stationary moving rotation centers5

Positioning the PatientPositioning the Patient Prepare the patient– Remove all removable appliances, metallichairclips, necklaces, chains (including thepatient bib!), earrings, etc. Tongue and liprings should also be removed, if at all possible– Explain the procedure to the patient Prepare the machine– Disinfect the machine– Place a new bitestick in the machinePositioning the PatientPositioning the Patient Position the patient– Patient must be as straight as possible– The patient’s neck should be extended– Anterior teeth should be in the notch on thebitestick– Tragus of the ear must be aligned with theplastic guides– Ala – Tragus line should be 50 from levelPositioning the Patient Position the patient– Panoramic lead apronmust be used– Position apron high infront to protect thethyroid– Apron should be lowerin back to expose theneck6

Positioning the PatientPositioning the Patient Instruct the patient––––Procedure takes less than ½ minutePatient must remain motionlessThe machine will revolve around the patientTongue must be kept against the hard palateImages courtesy of sitioning7

Panoramic Concepts Anterior midline is in the center of the film Posterior midline is beyond the left and rightedges of the image Structures appear flattened and spread outPanoramic ConceptsPanoramic ConceptsImages Seen on a PanoramicRadiograph Real Images Anterior midline is in the center of the film Posterior midline is beyond the left and rightedges of the image Structures appear flattened and spread out– Single images– Double images Ghost ImagesPanoramic Concepts Real images are formed when an object isradiographed between the center of rotationand the film Midline structures may appear as single ordouble images. Single and double imagesare real imagesReal ImagesX-ray SourceProjection of “Real”imageRotation CenterEarring8

Double Images Real images may bedouble images Double images areformed in zone incentral region Common doubleimages includeDouble Images If patient is positioned too far forward, thespine may appear as a double image– hard palate– soft palate– hyoid boneReal Images-Single and DoubleGhost Images Formed when anobject is between thesource and the centerof rotationGhost Images Appear on oppositeside of radiograph Appear superior to realimages Appear more blurredthan real images, buthave the samemorphologyGhost Images Common ghost images:––––L and R from machineSpineEarringsInferior border of the mandible9

Ghost ImagesGhost ImagesGhost ImagesImages--Real and GhostImages--Real and GhostSoft Tissue Outlines Seen best in edentulous patients Common soft tissue structures seen:––––Dorsum of tongueSoft PalateLipsNasolabial fold10

Soft Tissue OutlinesTongue and Soft PalateAir SpacesAir Spaces Maxillary sinuses Glossopharyngeal air space Nasal FossaInterpreting PanoramicRadiographs Examination is an orderly t tissueAir spacesTeethInterpreting PanoramicRadiographs Examine the borders ofthe bone first Next, examine themedullary bone Check the internalstructures such as canals,foramina, and sinuses Check the soft tissueshadows Examine the air spaces Save the teeth for last!11

Interpreting PanoramicRadiographsInterpreting PanoramicRadiographsInterpreting PanoramicRadiographsInterpreting PanoramicRadiographsInterpreting PanoramicRadiographsInterpreting PanoramicRadiographs12

Interpreting PanoramicRadiographsPanoramic Anatomy--DentateInterpretationPanoramic Anatomy-EdentulousTransitional Dentition13

Mixed Density LesionsMalignancyMalignancyImpacted MolarsImpacted MolarsCarotid Atheroma14

ArtifactsDental AnomaliesDental AnomaliesDental AnomaliesDental AnomaliesDental Anomalies15

FracturesFracturesSurgical ProceduresSurgical ProceduresSurgical ProceduresFollow-up16

PathosesOcclusal ViewsPathoses –Large LesionsPathoses –Large LesionsPathoses –Large LesionsPathoses17

PathosesQuestions?Question Everything!Thank you!18

Ghost Images Formed when an object is between the source and the center of rotation Ghost Images Appear on opposite side of radiograph Appear superior to real images Appear more blurred than real images, but have the same morphology Ghost Images Common ghost images: - L and R from machine - Spine - Earrings