8/26/20101Introduction to Introduction to Radiographic ImagingRadiographic ImagingImage InterpretationImage InterpretationObjectivesObjectives»» Understand the approach to interpretationUnderstand the approach to interpretation»» Know the conventional anatomic Know the conventional anatomic terminologyterminologyKht di hiiKht di hii»»Know how to name a radiographic viewKnow how to name a radiographic view»» Know how to “hang” a radiographic imageKnow how to “hang” a radiographic image»» List and understand the roentgen signsList and understand the roentgen signs»» Know and identify the five radiographic Know and identify the five radiographic opacitiesopacitiesReviewReview»» Radiograph is picture of xRadiograph is picture of x--rays able to rays able to penetrate object penetrate object –– literal literal shadowshadow of objectof object» Differential absorption of x-rays passing passing through tissues is basis of radiographythrough tissues is basis of radiographythrough tissues is basis of radiographythrough tissues is basis of radiography»» Radiograph is a twoRadiograph is a two--dimensional depiction dimensional depiction of a threeof a three--dimensional objectdimensional objectPrinciples of interpretationPrinciples of interpretation»» Review radiographs in appropriate environment Review radiographs in appropriate environment (low lighting, quiet)(low lighting, quiet)»» Be sure to have appropriate views and complete Be sure to have appropriate views and complete studystudyyy»» Hang radiographs in a standard mannerHang radiographs in a standard manner»» Make sure patient positioning and preparation Make sure patient positioning and preparation are adequateare adequate»» Make sure radiographic technique is appropriateMake sure radiographic technique is appropriate»» Evaluate entire radiograph systematicallyEvaluate entire radiograph systematicallyPrinciples of interpretationPrinciples of interpretation»» Radiographic interpretation Radiographic interpretation need not be mysteriousneed not be mysterious Knowledge of normal radiographic Knowledge of normal radiographic anatomy and possible variants isanatomy and possible variants isanatomy and possible variants is anatomy and possible variants is required!required! Be systematicBe systematic Use basic radiographic signsUse basic radiographic signs Formulate a differential diagnosis Formulate a differential diagnosis listlistConventional TerminologyConventional Terminology»» Use same terminology as in anatomy classUse same terminology as in anatomy class»» Trunk: cranial, caudal, dorsal, ventralTrunk: cranial, caudal, dorsal, ventral»» Head: rostral, caudal, dorsal ventralHead: rostral, caudal, dorsal ventral»»ExtremityExtremity»»ExtremityExtremity Above carpus and tarsus: cranial, caudal, proximal, Above carpus and tarsus: cranial, caudal, proximal, distaldistal At and below carpus and tarsus: At and below carpus and tarsus:  Front limb: dorsal, palmar, proximal, distalFront limb: dorsal, palmar, proximal, distal Rear limb: dorsal, plantar, proximal, distalRear limb: dorsal, plantar, proximal, distal8/26/20102Conventional TerminologyConventional Terminology Application QuestionApplication Question»» “Collimation” refers to restricting the x“Collimation” refers to restricting the x--ray ray beam to the confines of the imaging plate. beam to the confines of the imaging plate. What is one important reason to do this?What is one important reason to do this?Radiographic ViewsRadiographic Views»» Named according to the direction of the Named according to the direction of the xx--ray beam as it penetrates the body part ray beam as it penetrates the body part from from pointpoint--ofof--entranceentrance to to pointpoint--ofof--exitexitFor example during a ventrodorsalFor example during a ventrodorsalFor example, during a ventrodorsal For example, during a ventrodorsal projection of the thorax, the beam enters the projection of the thorax, the beam enters the ventral aspect of the thorax and leaves the ventral aspect of the thorax and leaves the dorsal aspect of the thorax while the patient dorsal aspect of the thorax while the patient is in dorsal recumbencyis in dorsal recumbencyVentrodorsal (VD) view of thoraxVentrodorsal (VD) view of thoraxX-ray beamVentrum Dorsum Radiographic ViewsRadiographic Views»» Technically, lateral views of abdomen/thorax Technically, lateral views of abdomen/thorax should be described as “right to left lateral” or should be described as “right to left lateral” or “left to right lateral”“left to right lateral” Convention shortens name:Convention shortens name: Left lateral Left lateral –– patient in left lateral recumbencypatient in left lateral recumbency Right lateral Right lateral –– patient in right lateral recumbencypatient in right lateral recumbency»» Technically, lateral views of extremities should Technically, lateral views of extremities should be described as “lateromedial” or “mediolateral”be described as “lateromedial” or “mediolateral” Convention shortens name:Convention shortens name: Lateral Lateral Right lateral view of the abdomenRight lateral view of the abdomenX-ray beamLeft lateral aspectRight lateral aspect8/26/20103Dorsopalmar (DP) view of carpusDorsopalmar (DP) view of carpusFrom From Tech of Vet Rad, 5th Tech of Vet Rad, 5th ed, Morgan JP, 1993ed, Morgan JP, 1993Radiographic ViewsRadiographic Views»» Oblique views are views that are made off Oblique views are views that are made off angle from the standard lateral and angle from the standard lateral and DP/CrCd viewsDP/CrCd viewsStill named by the path of the xStill named by the path of the xray beamray beamStill named by the path of the xStill named by the path of the x--ray beamray beam Technically should include angle of obliquity Technically should include angle of obliquity (dorsal 60(dorsal 60º lateralº lateral--palmaromedial oblique)palmaromedial oblique) Not needed for standardized viewsNot needed for standardized views However, degree of obliquity does change However, degree of obliquity does change appearanceappearanceDorsolateral-plantaromedial (DLPM) oblique view of tarsusDorsolateral-plantaromedial (DLPM) oblique view of tarsusFrom From Tech of Vet Rad, 5th Tech of Vet Rad, 5th ed, Morgan