T2-weighted turbo spin-echo images, maximum-intensity projections, and three-dimensional volume-rendering for delineation of pathologies and anatomic details of the inner ear

PURPOSE: The aim of the current study was to compare 3-dimensional T2-weighted turbo spin-echo (TSE) axial slices, maximum-intensity projections (MIPs), and volume-rendered images with respect to the delineation of pathologic findings and anatomic structures of the inner ear. Each of the compared image types was available at 2 different resolutions. MATERIALS AND METHODS: In 64 patients, 3-dimensional T2-TSE images were acquired with a matrix of 128 x 100 and 230 x 230 (field-of-view 90 x 90 mm). Direct axial images, MIPs, and volume-rendered images from the 2 datasets were evaluated in terms of the delineation of pathologic findings and anatomic structures. Analysis was performed by 2 radiologists in consensus. RESULTS: Though axial images acquired with a matrix of 230 x 230 showed more anatomic details than images acquired with a matrix of 128 x 100, pathologic findings (33 in total) were assessable with the same confidence on images of either resolution. Pathologies completely surrounded by fluid were best assessed on axial slices. The delineation of pathologies not embedded in a fluid was almost equally good in axial slices, MIPs, or 3-dimensional volume-rendered images. CONCLUSION: Reading the axial images cannot be replaced by viewing postprocessed reconstructions for initial diagnosis, because only some of the pathologies can be delineated on MIPs and volume reconstructions. However, reconstructions can be valuable for assessing the extent of pathologies and their spatial relation to the anatomic structures.