Holger Greess MD, Presenter: Nothing to Disclose

Sedat Alibek MD, Abstract Co-Author: Nothing to Disclose

Johannes Zenk MD, Abstract Co-Author: Nothing to Disclose

Alessandro Bozzato MD, Abstract Co-Author: Nothing to Disclose

Heinrich Iro MD, Abstract Co-Author: Nothing to Disclose

Werner A. Bautz MD, Abstract Co-Author: Nothing to Disclose

To evaluate the ability of dynamic contrast-enhanced MRI to differentiate several parotid tumor entities.

110 patients with 113 parotid tumors were examined with dynamic contrast-enhanced MR on a 1.5-T Siemens Symphony Erlangen/Germany during a period of 18 months. An axial T1-weighted SE sequence was performed to determine 5 selected slices for the dynamic study. Subsequently a T1-weighted FLASH sequence was used for the dynamic contrast study with 0.2 ml Gadolinium per kilogram bodyweight administered intravenously (flow 1.0 ml/sec.). Contrast agent application and the FLASH sequence were started simultaneously. 10 acquisitions of 10 seconds scan time were performed (total time 1.66 min.). Intensity versus time studies were performed in the region of interest. The examination was completed by axial T2 STIR and axial and coronal T1 SE FATSAT sequences.

Tumor entities were pleomorphic adenomas (40%), adenolymphomas (Warthin tumors) (21%), carcinomas (11%), lymph nodes (7%), oncocytomas (4%) and cysts (3%). Four typical intensity curves were observed: pleomorphic adenoma showed a gradual increase in signal intensity, followed by a plateau phase on a low intensity level. Cysts showed a vacillate course at a low signal intensity level. Adenolymphomas as well carcinomas showed a rapid increase in signal intensity followed by a plateau phase, but peak values were strikingly different with > 500 in adenolymphomas versus > 1000 in carcinomas. Together with the other MR criteria (contrast enhancement, sharp or blurred border) and clinical criteria a differentiation between adenolymphomas and carcinoma was possible.

With dynamic contrast-enhanced MR studies, differentiation between the common parotid tumors before surgery is possible.

Greess, H, Alibek, S, Zenk, J, Bozzato, A, Iro, H, Bautz, W, The Value of Dynamic Signal Intensity MRI Studies in Parotid Tumors.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4410425.html