The Study Of MRI Applied In Cervical Lymphadenopathy: Differentiation Between Metastatic Squamous Cell Carcinoma And Reactive Lymphadenitis

OBJECTIVE:To investigate the potential role of routine MRI, DCE-MRI and DWI in differentiation between cervical metastatic squamous cell carcinoma(MSCC) and reactive lymphadenitis(RL).MATERIALS & METHODS:1. Basic materials:71 patients with cervical enlarged lymph nodes were collected from March 2008 to November 2010, comprised 50 cases of cervical MSCC and 21 cases of RL. All cases were definitely diagnosed by pathology or clinical treatments. Among 71cases, MRI plain scan and contrast-enhanced T1-weighted imaging were taken in 37 cases, while MRI plain scan, DW-MRI, DCE-MRI, and contrast-enhanced T1-Weighted imaging were taken in the other 34 cases.2. Image analysis and data processing:To analyze the MRI signs of enlarged cervical lymph nodes, including location, the maximum short axial diameter, the feature of inner signal intensity and the feature of contrast-enhanced rim. Based on the different feature of contrast-enhanced rim, lymph nodes collected were divided into typeⅠ,Ⅱ,Ⅲ,Ⅳfor statistical analysis. The data collected from DCE-MRI and DWI was processed by Functool software of GE ADW4.2 workstation. Regions of interest (ROIs) were drawn, and the ADC value and the data of some characteristic parameters with DCE-MRI are recorded for statistical analysis, including positive enhancement integral, time to peak, maximum slope of increase. Based on the different shape of T-SI curves, lymph nodes collected were divided into type A,B,C for statistical analysis.3. Statistical analysis:Statistical software of SPSS13.0 version was applied. Statistics was recorded in the form of mean±standard deviation (Mean±SD).The enumeration data was measured by chi-square test, and the measurement data was calculated by analysis of variance and ambi-independence sample t-test. And the difference was considered to be of statistical significance when the P-value was less than 0.05.RESULTS:Level II and III were the predilection sites in both cervical MSCC and RL. There was statistical difference for type II and III in the feature of contrast-enhanced rim between cervical MSCC and RL (P<0.05). If type I and type II were considered as the diagnostic criteria for RL, and type III and type IV were considered as the diagnostic criteria for cervical MSCC, the sensitivity, the specificity, the accuracy, the positive predictive value and the negative predictive value were 89.1%,86%,88.1%,93.4% and 77.8%, respectively.There was statistical difference in terms of type A and C of T-SI curve between cervical MSCC and RL(P< 0.05). If type A was considered as the diagnostic criteria for MSCC and type B and C were considered as the diagnostic criteria for RL, the sensitivity, the specificity, the accuracy, the positive predictive value, and the negative predictive value were 55.6%, 91.3%,72%,88.2% and 63.6%, respectively. If type A and B were considered as the diagnostic criteria for cervical MSCC and type C was considered as the diagnostic criteria for RL, the sensitivity, the specificity, the accuracy, the positive predictive value and the negative predictive value were 88.9%,52.2%,72%,68.6% and 80%, respectively. There was statistical difference in terms of positive enhancement integral and time to peak between cervical MSCC and RL (P<0.05).The mean ADC value was (0.964±0.222)×10-3mm2/s for cervical MSCC, and (1.107±0.238)×10-3 mm2/s for RL. The mean ADC value of cervical MSCC was significantly lower than the mean ADC value of reactive lymphadenitis. And the difference was of statistical significance (P=0.013).CONCLUSIONS:Type of the contrast-enhanced rim findings is a useful indicator in differentiation between cervical MSCC and RL(maximum short axial diameter≥8mm); DCE-MRI and DWI are of great value for the differentiation.