Role of high-resolution magnetic resonance imaging for differentiating melanin-containing skin tumors.
OBJECTIVE
The aim of the study was to evaluate the use of high resolution magnetic resonance imaging (MRI) for differentiation of melanin-containing skin tumors.


METHODS
Twenty-seven melanocytic nevi and 18 malignant melanomas were examined by high resolution MRI. Signal intensities and signal-to-noise (SNR) and contrast-to-noise ratios (CNR) of the tumors were determined in enhanced (T1, T2, water-suppression, and fat-suppression sequences) and contrast-enhanced images (T1 and fat-suppression sequences). The differences were tested for significance by a Wilcoxon test.


RESULTS
Malignant melanomas differed from melanocytic nevi in that they displayed a higher SNR in T2-weight and unenhanced and contrast-enhanced fat-suppression scan. Malignant melanomas exhibited a higher CNR than did benign lesions in unenhanced and contrast-enhanced fat-suppression sequences with dermis as reference tissue (P < 0.05) and in enhanced fat-suppression sequences with subcutis as reference tissue (P < 0.05).


CONCLUSIONS
The usefulness of SNR and CNR analysis on MRI for the differentiation of malignant skin tumors from benign skin tumors of the melanin-containing system is limited. Clinical and histologic examinations are, further, the important step in evaluation of melanin-containing skin tumors.
Mäurer
J
J
Strahlenklinik und Poliklinik, Medizinische Fakultät, Humboldt-Universität zu Berlin, Germany.
Knollmann
F D
FD
Schlums
D
D
Garbe
C
C
Vogl
T J
TJ
Bier
J
J
Felix
R
R
D000273:Adipose Tissue; D000293:Adolescent; D000328:Adult; D000368:Aged; D001834:Body Water; D003287:Contrast Media; D003937:Diagnosis, Differential; D004338:Drug Combinations; D005260:Female; D005682:Gadolinium; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine; D008543:Melanins; D008545:Melanoma / Q000175:diagnosis*; D008875:Middle Aged; D018329:Nevus, Blue / Q000175:diagnosis; D018330:Nevus, Intradermal / Q000175:diagnosis; D009508:Nevus, Pigmented / Q000175:diagnosis*; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives; D011446:Prospective Studies; D012815:Signal Processing, Computer-Assisted; D012867:Skin; D012878:Skin Neoplasms / Q000175:diagnosis*
D003287:Contrast Media; D004338:Drug Combinations; D008543:Melanins; D009942:Organometallic Compounds; D008536:Meglumine; D004369:Pentetic Acid; D005682:Gadolinium; D019786:Gadolinium DTPA