Matthias Philipp Lichy MD, Presenter: Nothing to Disclose

Hansjoerg Graf, Abstract Co-Author: Nothing to Disclose

Florian Dammann MD, Abstract Co-Author: Nothing to Disclose

Heinz-Peter Wilhelm Schlemmer MD, Abstract Co-Author: Nothing to Disclose

Claus Detlef Claussen MD, Abstract Co-Author: Nothing to Disclose

Fritz Schick MD, Abstract Co-Author: Nothing to Disclose

To acquire high resolution MR images of inner ear structures using a 3T MRI scanner and an 8-channel phased array head-coil.

Temporal bones were examined in 9 healthy volunteers at 1.5T and 3T with 40 mT/m gradient systems and the CP (transmit and receive) and the 8-channel head coil (receive only). Re-phased gradient-echo sequences were applied (3D-CISS: TR/TE = 9.27/4.64 ms, resolution: isotropic (0.3-0.4 mm)3, 100 mm FOV, 50% phase oversampling, 1 average, measuring time: 5-7 min). Two experienced radiologists evaluated quality of MRI (completeness and uniformity of the inner ear structures, noise impression, artifacts on original images and maximum intensity projections).

The 8-channel head coil was characterized by better formfitting to the head resulting in improved image quality at 1.5 and 3T. Although the excitation angle had to be reduced (from 70° to 40-50°) at 3T, SNR improvement was at least 30% compared to 1.5T (CP head coil). Image quality was best with the 8-channel coil at 3T. Although pulsation artifacts of the internal carotid artery and band-like artifacts caused by B0-inhomogeneity were pronounced at 3T, structures of interest were not affected.

Detailed visualization of inner ear structures with isotropic voxels sizes of 30µm3 is feasible at 3T by using an 8-channel head coil. Improved spatial resolution may be helpful for assessing Ménière´s disease or cholear fibrosis in a clinical setting.

Lichy, M, Graf, H, Dammann, F, Schlemmer, H, Claussen, C, Schick, F, High Field MRI of the Inner Ear.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4405216.html