The Value of Diffusion-Weighted Magnetic Resonance Image in the Evaluation of Temporal Bone Cholesteatoma


BACK GROUND :Cholesteatoma is non-neoplastic destructive lesion .MRI including diffusion weighted imaging(DWI) is helpful, since high content of keratin is associated with restricted diffusion.AIM OF STUDY:To determine the value of DWMRI and apparent diffusion coefficient (ADC) value in diagnosis oftemporal bone cholesteatoma .PATIENTS AND METHOD :A prospective study conducted 33 patients with clinical suspicious of cholestatoma using 1.5teslaMRI scanner ,DWI with bvalue 1000 sec/ mm2.ADC was reconstructed and mean value measuredin mm2/sec for each lesion .Enhancing image obtained after intravenous contrast administrationwith early and delay images in suspected recurrent cases .RESULT:DWI accurately detect 22 of 25 cholesteatoma lesions (sensitivity = 88% and specificity =100%).Positive predictive value and negative predictive value were 100% and76.9% respectivelywith accuracy rate 91.4%. ADC value revealed (0.469 x10-3 to 0.823 x10-3 mm2/sec) forrestricted lesions with mean value ( 0.653 x10-3 ± 0.09092 SD mm2 /sec)which is significantlydifference from non restricted lesions(P value less than 0.001) .T1W post contrast images alsogive high accuracy in diagnosis of cholesteatoma 23 from 25 cases (sensitivity =92.59 %,specificity = 100).CONCLUSION:MRDWI give high accuracy in detection of cholestatoma in patient with chronic ear discharge.