Rofo 2009; 181 - A15
DOI: 10.1055/s-0028-1124046

High Resolution MRI of the Parotid Gland and Duct at 7 Tesla

O Kraff 1, 2, PC Kokulinsky 1, 2, JM Theysohn 1, 2, S Maderwald 1, 2, S Kruszona 1, 2, Z Dogan 3, ME Ladd 1, 2, ER Gizewski 1, 2, SC Ladd 1, 2
  • 1Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Germany
  • 2Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Germany
  • 3Department of Otorhinolaryngology, University Hospital Essen, Germany

Purpose: To assess optimized GRE and TSE sequences at 7T for high-resolution MRI of the parotid gland and duct.

Materials and Methods: A Magnetom 7T whole-body scanner (Siemens) was used in combination with a 10-cm-diameter loop coil (Rapid Biomed). GRE (MEDIC, DESS) and TSE (PD/T2, STIR) sequences were applied in five healthy volunteers and four patients with suspicion of gland inflammation or tumors. High-resolution images were compared with 1.5T images. SNR and CNR were calculated between duct and surrounding tissue. A visual evaluation of the overall quality was performed.

Results: The high 0.6mm isotropic resolution of the 3D-DESS sequence was very useful to define an oblique orientation with most of the duct being in-plane for the subsequent imaging. With the MEDIC sequence very fine branches of the duct are visible; furthermore, MEDIC yields a very good depiction of lymph nodes. The gland tissue in tumor patients can be well evaluated with the PD/T2 TSE. Severe SAR problems were observed with the STIR sequence at 7T. The visual assessment of image quality yielded a superiority of the 7T sequences compared to the according 1.5T sequences. Only the 1.5T STIR sequence showed comparable quality. Highest CNR between duct and gland was achieved with the 7T DESS sequence. The MEDIC sequence yielded 5.8 times higher CNR between duct and gland at 7T than at 1.5T.

Conclusion: MR imaging at 7T provides excellent image contrast and resolution of the parotid gland and duct. The proposed protocol offers a non-invasive examination within about 20 minutes.