Diffusion-weighted MR imaging for evaluation of pediatric recurrent XXXX .

@entity1 @entity3540 @entity2172 @entity5377
OBJECTIVE: To compare the efficiency of diffusion-weighted MR imaging (MRI) vs. high resolution CT in predicting recurrent or residual @entity3540 in @entity1 who underwent prior @entity2172 surgery. DESIGN: Prospective study. SETTING: Tertiary care university hospital. @entity1 : Seventeen @entity1 (4 with 2 recurrences) aged 5-17 years (mean 11.4) previously surgically treated for a @entity3540 of the @entity2172 , were included for follow-up with systematic CT scan and MRI, between 2005 and 2007. METHODOLOGY: CT scan was performed on a @entity5377 Somaton 64 (0.5/0.2 mm slices reformatted in 0.5/0.3 mm images), parallel and perpendicular to the lateral semi-circular canal for each ear (100 mmx100 mm FOV). MRI was undertaken on a @entity5377 Avanto 1.5 T unit, with an adapted protocol for young @entity1 . Diagnosis of recurrent @entity3540 was based on the evidence of a hyperintense image at B1000 on diffusion-weighted images. Results of CT scan and MRI were compared with operative diagnosis. RESULTS: Nine @entity1 had a positive MRI, among which 8 had @entity3540 confirmed during revision surgery. In the 12 negative MRI cases, 5 were positive on revision surgery. None of these lesions was over 3mm. Two of them were diagnosed on the CT scan. CT scan alone had a positive predictive value of 75%, and a negative predictive value of 58%. CONCLUSION: Diffusion-weighted MRI is associated with a high positive predictive value for the detection of recurrent @entity3540 . CT scan remains the first choice imaging technique. In case of doubtful CT scan, diffusion-weighted MRI could confirm a recurrence or, when negative, avoid second-look surgery.
