PowerPoint Presentation

HRCT TEMPORAL BONE AND MRI BRAIN FOCUS ON INNER EAR Dr. Neeraj. M. Suri Asso prof ENTGMERS Gandhinagar

PRESENTATION OUTLINEAXIAL PROJECTIONSCORONAL PROJECTIONSDISCUSSION ON SCANS OF INNER EAR ABNORMALITIES

AXIAL PROJECTIONSTechnical considerations Protocol

Patient position - Supine in head restStart position Skull baseEnd position Superior margin of petrous temporal bone Gantry angle 30o cranial to infraorbital meatal lineSlice thickness 1mmTable increment 1mmKilovoltage 140 kV.mAs per slice 300 mAs (150 nA,2 sec scan time)Algorithm BoneScan field of view 25 cmDisplay field of view 18 cmWindow width 4000window level - 750

Axial CT images show the normal anatomy of the temporal bone from inferior (a) to superior (g).

IAC internal auditory canal. ICA internal carotid artery, LSCC Lateral semicircular canal, PSCC Posterior semicircular canal, SSCC Superior semicircular canal

Axial CT images show the normal anatomy of the temporal bone from inferior (a) to superior (g).3

CORONAL PROJECTIONSTechnical considerations Protocol

Patient position - Prone with head extendedStart position Anterior margin of petrous temporal bone End position Posterior margin of petrous temporal bone Gantry angle 90o to skull basde of middle cranial fossaSlice thickness 1mmTable increment 1mmKilovoltage 140 kV.mAs per slice 300 mAs (150 nA,2 sec scan time)Algorithm BoneScan field of view 25 cmDisplay field of view 18 cmWindow width 4000window level - 750

Coronal CT images show the normal anatomy of the temporal bone from anterior (a) to posterior (g).

Ant. - Anterior m. muscle, n. nerve, t - tendon LSCC Lateral semicircular canal,SSCC Superior semicircular canal

Axial CT images show the normal anatomy of the temporal bone from inferior (a) to superior (g).4

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1. Axial hypotympanic jugular foramen levelc

3.

domeCanal for cochlear nerve

1 & turn of CochleaLike food in a plateRW nicheBasal turn Of cochlea

Lower to IAC& smaller to itIAC

Vestibular AqueductsyndromeIACNormal vestibular Aqueduct1-2mm in diameter

- Inverted V shapedTympanic segmentLabyrinthine segment

SuperiortegmenH-SCCSup-SCCVestibuleIACOW7th NCrossing BelowL-SCC

Coronal imagesMastoid Portion of7th nerveLabyrinthinesegmentTympanic segmentAppears like Snake eyes

Coronal sections

Coronal sections52

3.

ABNORMAL INNER EAR SCANS

Examples of some Complicated scans65

Absent nerve mondini on left side

Absent nerve mondini on left side66

bilateral absence of bony partition between iac and basal turn modiolus absent

bilateral absence of bony partition between iac and basal turn modiolus absentbilateral absence of bony partition between iac and basal turn modiolus absent

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cystic cochlea

Dilated iac

cochlear aplasia

Dysplastic vestibule cochlear aplasia

Facial nerve

Facial nerve72

High jugular

Iac mri

Ice cream appearance

cochlea

cochlea76

MRI endolymphatic sac

MRI cystic cochlea

MRI dilated iac

OSSIFICATION IN COCHLEA80

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THANKS

THANKS85