jalal jalal shokouhi-md diffusion imaging of cholesteatomas
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cholesteatomas
Epidermoid inclusion cystCystic creatinin-filled massLined by stratified squamous epitheliumCommon in frontal bone and earCause: secondary to trauma and implanted
inner table, outer table
jalaljalalshokouhi@hotmail.com www.medimage.ir
Mucoid like content DDx with mucoceleFat content of cholestrol T1-MR signal
T2
Intermediate
Intermediate
high
jalaljalalshokouhi@hotmail.com www.medimage.ir
Acquired cholesteatoma Expansile concentrically enlarging
collection of exfoliated keratin lined by keratinizing stratified squamous epithelium
Not neoplasm May or may not contain cholesterol crystals Congenital (epidermoid) 2% Acquired in middle ear 98%
jalaljalalshokouhi@hotmail.com www.medimage.ir
Acquired: Pars flexia (attic) -> prussak`s space -> mastoid Pars tensa
Acquired: Primary acquired (no infection) Secondary acquired (infection)
Etiology: retraction*, papillary proliferation, immigration, metplasia
jalaljalalshokouhi@hotmail.com www.medimage.ir
Imaging:X-ray CT bone destruction, soft tissue
demo. And complications, uncommon granulation tissue
MR spine-echo non-specific signal moderately Hyperintense (better for tegmen tympani and sinus) exclude
facial nerve involvement GD for granulation tissue versus non-enhancing
cholesteatoma
jalaljalalshokouhi@hotmail.com www.medimage.ir
Diffusion-weighted imagingCholesteatoma is bright means restricted diffusion and
(T2 shine through) Please be aware eddy current artifacts, susceptibility
artifacts, ghosting artifacts, chemical shift and motion artifacts all are prevalent
Higher magnetic fields increase potential of these artifacts in echo-planar DWI
Turbo spin-echo DWI in known to limit, these distortions
Multi shot fast spin-echo periodically rotated overlapping parallel lines with enhanced reconstructions (PROPELLER) DWI= enhanced detection of the lesion (and limiting artifact in high fields)
jalaljalalshokouhi@hotmail.com www.medimage.ir
If there is no middle ear surgery positive predictive value is 93% and negative predictive value is 100%
Sensitivity and specificity 91-100%
DW FAST-SPIN-ECHO Factor 14
Matrix of resolution: 192 x 256
“a” “b” factor 800 second/mm2
1.5 tesla
9 sections in 2.5 mm
3’ 38”
FOV= 230mm
RSNA 2005
DW non-echoplanarDW of middle ear cholesteatoma differ from
abscess and infected cholesteatoma AJNR
DW for post-operative recurrent JU-radiology
jalaljalalshokouhi@hotmail.com www.medimage.ir
T2 left recurrent cholesteatoma-Right granulation tissue
GD T1 enhanced right-non-enhanced left
DW ab factor: 0 - 2.5 mm both DW ab factor: 800-2.5 mm right left
All complications related to bone destruction (mechanical)
C.O.M., vertigo, labyrinthin fistula(more morbidity) in lat. Semicircular canal (18-49)
Facial nerve palsy or paresis (1%)
jalaljalalshokouhi@hotmail.com www.medimage.ir
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