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
83
THANKS
THANKS85