RADIOGRAPHY OF EYE

BY RAVI JAICHANDRADIOGRAPHERINDIA

EYE

ORGAN OF VISION

LATIN -OCULUS

GREEK-OPHTHALMUS

ANATOMY

• INDICATION

LOCALIZATION OF FOREIGN BODY

•ALTERNATE TECHNIQUES USED ULTRASOUND AND COMPUTED TOMOGRAPHY

MRI SHOULD NEVER BE USED

OBSOLETE METHODS VOGT METHOD

SWEET METHOD

PFEIFFER COMBERG METHOD

PARALLAX MOTION METHOD

• IMAGE QUALITY IS OF SUPREME IMPORTANCE FOR

DETECTION AND LOCALIZATION OF MINUTE FOREIGN PARTICLES.

•TO IMPROVE IMAGE QUALITY REDUCE GEOMETRIC UN SHARPNESS

USE CLOSE OID

USE SMALL FOCAL SPOT

USE STANDARD FFD

IMAGE QUALITY • MINIMIZE SECONDARY RADIATION (USE CLOSE

COLLIMATION)

• USE IMMOBILIZATION DEVICES TO IMMOBILIZE HEAD.HAVE THE PATIENT GAZE STEADILY AT A FIXED OBJECT SO AS TO IMMOBILIZE EYEBALLS.

IMAGE RECEPTORS MUST BE VERY CLEAR AS

ANY ARTIFACT CAN SIMULATE FOREIGN BODY

(CAN HAVE RESERVE IMAGE RECEPTOR FOR EYE STUDIES ONLY)

BASIC PROJECTIONS

• LATERAL PROJECTION

• PA AXIAL PROJECTION

• PARIETOCANTHAL PROJECTION (MODIFIED WATER’S VIEW)

IF A FOREIGN BODY IS SUSPECTED, THEN A SECOND PROJECTION MAY BE UNDERTAKEN, WITH THE EYES IN A DIFFERENT POSITION TO DIFFERENTIATE THIS FROM AN IMAGE ARTIFACT. THE INITIAL EXPOSURE COULD BE TAKEN WITH THE EYES POINTING UP AND THE SECOND WITH THE EYES POINTING DOWN.

LATERAL PROJECTION

RIGHT OR LEFT

USE NON GRID TECHNIQUE TO REDUCE MAGNIFICATION AND ARTIFACTS FROM RADIOGRAPHIC TABLE AND GRID

LATERAL PROJECTIONSEMIPRONE OR ERECT

Mid sagittal plane of the patient parallel to

the image receptor

Affected eye adjacent tocenter of image receptor

Inter pupillary line perpendicular to the

image receptor

Exposure made in suspended respiration

LATERAL PROJECTION CENTRAL RAY

PERPENDICULAR THROUGH THE OUTER

CATHUS

INSTRUCT THE PATIENT TO

LOOK STRAIGHT

AHEAD DURING

EXPOSURE

LATERAL PROJECTION EVALUATION CRITERIA

CLOSE BEAM RESTRICTION

SUPERIMPOSITION OF ORBITAL ROOF

OPTIMUM DENSITY AND CONTRAST FOT

VISUALIZATION OF FOREIGN BODY

PA AXIAL PROJECTION

USE NON GRID TECHNIQUE TO REDUCE MAGNIFICATION AND ARTIFACTS FROM RADIOGRAPHIC TABLE AND GRID

PA AXIAL PROJECTIONPATIENT POSITIONINGEXPOSURE MADE IN SUSPENDED RESPIRATION

PATIENT’S HEAD REST OVER THE

IMAGE RECEPTOR

RADIOGRAPHIC BASE LINE

PERPENDICULAR TO THE IMAGE RECEPTOR

PA AXIAL PROJECTION CENTRAL RAY

INSTRUCT THE PATIENT TO CLOSE EYES

&CONCENTRATE HOLDING THEM

STRAIGHT

THROUGH THE CENTRE OF THE ORBITS WITH 30 DEGREE CAUDAL

ANGULATION, PROJECT THE

PETROUS PORTION OF THE TEMPORAL

BONE BELOW INFERIOR MARGIN

OF ORBITS

EVALUATION CRITERIA

NO ROTATION OF THE CRANIUM

PETROUS PYRAMIDS LYING BELOW ORBITAL SHADOW

BEAM RESTRICTION CENTRED TO ORBITAL MARGINS

PARIETOCANTHAL PROJECTIONMODIFIED WATER’S VIEW

THE PETROUS MARGINS ARE DISPLACED BY PART ADJUSTMENT RATHER THAN BY CENTRAL RAY ANGULATION

PARIETOCANTHAL PROJECTIONPATIENT POSITIONINGEXPOSURE MADE IN SUSPENDED RESPIRATION REST

PATIENT’S CHIN ON IMAGE

RECEPTOR HOLDER

MID SAGGITAL PLANE

PERPENDICULAR TO THE PLANE

OF IMAGE RECEPTOR

ADJUST THE FLEXION OF THE HEAD SO THAT THE

RADIOGRAPHIC BASE LINE FORMS AN ANGLE OF 50 DEGREES WITH THE IMAGE RECEPTOR

PARIETOCANTHAL PROJECTION CENTRAL RAY

PERPENDICULAR THROUGH THE MID ORBITS

INSTRUCT THE PATIENT TO CLOSE EYES AND CONCENTRATE ON HOLDING THEM

STRAIGHT

EVALUATION CRITERIA

NO ROTATION OF THE CRANIUM

PETROUS PYRAMIDS LYING BELOW ORBITAL SHADOW

BEAM RESTRICTION CENTRED TO ORBITAL MARGINS

REFERENCES

• MERRILL'S ATLAS OF RADIOGRAPHIC POSITIONS AND RADIOLOGIC PROCEDURES. ED 10,VOLUME 2, AUTHORS PHILIP W. BALLINGER ,EUGENE D. FRANK

• CLARK’S POSITIONING IN RADIOGRAPHY,12TH EDITION, AUTHORS A. STEWART WHITLEY CHARLES SLOANE GR AHAM HOADLEY ADRIAN D. MOORE CHRISSIE W.ALSOP