[Value of contrast-enhanced ultrasound vs. CT and MRI in palpable enlarged lymph nodes of the head and neck]. / Wertigkeit der kontrastmittelverstärkten Sonographie von Lymphknotenvergrösserungen im Kopf-Hals-Bereich versus Computertomographie und Magnetresonanztomographie.

ABSTRACT

PURPOSE: To compare the value of B-mode-, plain and contrast enhanced color Doppler ultrasound, CT and MRI with respect to their diagnostic accuracy in palpable enlarged cervical lymph nodes. MATERIAL AND METHODS: Thirty patients (18 - 90 years old) with palpable enlarged lymph nodes of the head and neck underwent B-mode-ultrasound, plain and contrast enhanced color Doppler, CT and MRI (gold standard histologic analysis in 22 and clinical follow up for at least six months in eight patients). The criteria of malignancy were maximal and minimal lymph node diameter, M/Q-ratio, various morphologic criteria (necrosis, hilus line, internal structure, contour, contrast enhancement), spectral Doppler indices, and vascular architecture in color Doppler. RESULTS: The highest sensitivity (= 1.00, specificity = 0.07 - 0.15) was obtained measuring the lymph node diameter independent on the used imaging modality (ultrasound, CT, MRI), the highest specificity (= 1.00, sensitivity = 0.71) analyzing the vascularity of the lymph node by plain color Doppler. The highest diagnostic (= 0.93) accuracy was delivered by contrast enhanced color Doppler analysis of the vascularity. Sensitivity (= 0.94) and specificity (= 0.92) of this imaging modality were only slightly inferior to the top values. Fisher's exact test revealed significant values in differentiating malignant from benign lymph nodes for B-mode- and MR-analysis of the M/Q-ratio (p < 0001/p < 0.05), B-mode morphology (p < 0.00005), plain and contrast enhanced color Doppler analysis of the vascularity (p < 0.0001/p < 0.000005), MR-morphology (p < 0.0001), and CT-morphology (p < 0.005). CONCLUSION: CT is inferior to MRI, B-mode-ultrasound and contrast-enhanced color Doppler in the differential diagnosis of selectively analyzed, palpably enlarged cervical lymph nodes using the criteria of our study. The analysis of the MR-morphology revealed a slightly inferior diagnostic accuracy to B-mode morphology and color Doppler analysis of the vascularity.