ObjectiveTo examine the potential of two magnetic resonance imaging (MRI)
techniques-dynamic contrast enhancement (DCE) and diffusion-weighted imaging
(DWI)-for the detection of malignant cervical lymph nodes.Materials and MethodsUsing DCE and DWI, we evaluated 33 cervical lymph nodes. For the DCE
technique, the maximum relative enhancement, relative enhancement, time to
peak enhancement, wash-in rate, wash-out rate, brevity of enhancement, and
area under the curve were calculated from a semi-quantitative analysis. For
the DWI technique, apparent diffusion coefficients (ADCs) were acquired in
the region of interest of each lymph node. Cystic or necrotic parts were
excluded. All patients underwent neck dissection or node biopsy. Imaging
results were correlated with the histopathological findings. None of the
patients underwent neoadjuvant treatment before neck dissection.ResultsRelative enhancement, maximum relative enhancement, and the wash-in rate were
significantly higher in malignant lymph nodes than in benign lymph nodes
(p < 0.009; p < 0.05; and
p < 0.03, respectively). The time to peak
enhancement was significantly shorter in the malignant lymph nodes
(p < 0.02). In the multivariate analysis, the
variables identified as being the most capable of distinguishing between
benign and malignant lymph nodes were time to peak enhancement (sensitivity,
73.7%; specificity, 69.2%) and relative enhancement (sensitivity, 89.2%;
specificity, 69.2%).ConclusionAlthough DCE was able to differentiate between benign and malignant lymph
nodes, there is still no consensus regarding the use of a semi-quantitative
analysis, which is difficult to apply in a clinical setting. Low ADCs can
predict metastatic disease, although inflammatory processes might lead to
false-positive results.