Published in Cancer Detection and Prevention 1998; 22(6):540-543.

Delineation of Maxillofacial Cutaneous Lesions by Means of High Resolution Magnetic Resonance Imaging

J. Mäurer, M.D.,a F.D. Knollmann, M.D.,a B. Hell, M.D.,b C. Radke, M.D.,c R. Felix, M.D.a

aStrahlenklinik und Poliklinik, bAbt. fur Mund-, Kiefer-und Gesichtschirurgie, cPathologisches Institut, Virchow-Klinikum Medizinische Fakultat der Humboldt-Universitat zu Berlin

ABSTRACT: To evaluate the use of high-resolution MRI for the differentiation of skin tumors in the maxillofacial region, 60 patients (25 female) were examined in a 1.5 T whole body MR imager with a 2.5cm surface coil. Plain transverse TI-(TR 500 ms, TE 25 ms), T2- (2200 ms, TE 80 ms), fat- (TR 500 ms, TE 28 ms) and water-suppressed (TR 500 ms, TE 38 ms) SE-sequences were used. Following the application of the paramagnetic contrast agent Gd-DTPA, transverse T1-weighted and fat-suppression sequences were repeated. Before and after contrast administration, tumor signal intensities and percent contrast enhancement were determined by a ROI technique. All tumors were classified by standard histologic technique and evaluated with regard to their response to contrast medium. Quantitative evaluation was performed by three independent radiologists. Additionally, signal- and contrast- to noise ratios were calculated for each tumor type. All MRI findings were compared to histology. Significant contrast enhancement occurred in most tumors; malignant tumors displayed inhomogeneous enhancement. The optimal pulse sequences for tumor delineation are plain T1-weighted, water-suppressed and contrast-enhanced fat-suppressed sequences. Tumors could not be specified by signal intensities or percent contrast enhancement and CNR did not allow for malignant lesions to be differentiated from benign tumors. High-resolution MRI proved to be an adequate method for imaging skin tumors and their inner structure. Tumor typing was not possible by either contrast-administration or modification of sequence parameters. In this regard, further innovations in contrast agent design seem to be necessary.

KEY WORDS: skin tumors, High resolution technique, contrast medium.