Jalal jalal shokouhi-MD DIFFUSION IMAGING OF CHOLESTEATOMAS

cholesteatomas Epidermoid inclusion cyst Cystic creatinin-filled mass Lined by stratified squamous epithelium Common in frontal bone and ear Cause: secondary to trauma and implanted inner table, outer table

Mucoid like content DDx with mucocele Fat content of cholestrol T1-MR signal T2 Intermediate high

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%

Frontal chole.

Frontal chole.

Frontal chole.

Acquired: Pars flexia (attic) -> prussak`s space -> mastoid Pars tensa Acquired: Primary acquired (no infection) Secondary acquired (infection) Etiology: retraction*, papillary proliferation, immigration, metplasia

prussak`s space- pars flexida

prussak`s space- pars flexida

Petrosal cholesteatoma -> Apex

Petrosal chole. APEX

Pars tensa

Pars tensa

Pars tensa

Pars tensa and tegmental erosion

Ossicular erosion

Facial canal erosion

Acquired cholesteatoma

Acquired cholesteatoma

Acquired cholesteatoma

Auto mastoidectomy

Auto mastoidectomy

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

Epidermoid

Epidermoid

Epidermoid

EAC chol. with no atresia

EAC chol. with no atresia

Cholesteatoma of EAC with atresia

CH. In vestibula

Boney sequestra Ossicular

Chole. In EAC

Large Chole. In EAC

Chole. In middle ear and EAC

Osteopetrosis

In location of geniculate ganglion

Diffusion-weighted imaging Cholesteatoma 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)

If there is no middle ear surgery positive predictive value is 93% and negative predictive value is 100% Sensitivity and specificity % 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-echoplanar DW of middle ear cholesteatoma differ from abscess and infected cholesteatoma AJNR DW for post-operative recurrent JU-radiology

T2 left recurrent cholesteatoma-Right granulation tissue GD T1 enhanced right-non-enhanced left DW ab factor: mm both  DW ab factor: 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%)