Role of Dynamic Contrast-Enhanced MRI in Differentiation Between Malignant and Benign Cervical Lymph Nodes: A Case-Control Study

Background: Changes in signals and parameters of time-signal intensity curve (TIC) resulting from dynamic magnetic resonance imaging (MRI) have been considered for determining malignancy. However, the specific diagnostic criteria of TIC for detecting malignancy in various organs, such as lymph nodes, are not yet well-established. Objectives: This study aimed to evaluate the role of some TIC parameters in identifying malignant cervical lymph nodes. Patients and Methods: In this case-control study, patients with cervical lymphadenopathy were examined by dynamic contrast-enhanced MRI (DCE-MRI) before excisional biopsy. They were then divided into malignant and benign groups based on histopathology. Malignant patients were considered as the case group, while benign cases were considered as the control group. The TIC parameters included the signal intensity (SI) at 45 seconds, 90 seconds, 120 seconds, 5 minutes, and 10 minutes, as well as maximum signal intensity (SImax), the time at which the maximum signal intensity occurs (Tmax), the peak signal intensity (SI peak), and the time at which the peak signal intensity occurs (T peak). Additionally, the enhancement slope (ES), washout ratio (WR), and washout slope (WS) were evaluated at 5 and 10 minutes. Results: A total of 63 patients were enrolled in the study, including 31 (49.2%) patients with benign lymphadenopathies and 32 (50.8%) patients with malignant lymphadenopathies. Among the variables under study, significant differences were observed between the malignant (M) group and the benign (B) group in terms of the SI-5 min, SI-10 min, WR-5 min, WR-10 min, and WS-5 min (SI-5 min: 124.4 +/- 145 (B) vs. 219.2 +/- 93.8 (M), P = 0.003; SI-10 min: 109.9 +/- 134.6 (B) vs. 188.9 +/- 83.7 (M), P = 0.007; WR-5 min: 0.58 +/- 0.38 (B) vs. 0.15 +/- 0.13 (M), P < 0.001; WR-10 min: 0.63 +/- 0.36 (B) vs. 0.26 +/- 0.17 (M), P < 0.001; and WS-5 min: 0.93 +/- 1.20 (B) vs. 1.40 +/- 4.44 (M), P = 0.001). In the receiver operating characteristic (ROC) curve analysis, WS-5 min showed specificity of 29.1%, 75%, 90%, and 95% and sensitivity of 88.2%, 70.6%, 47.1%, and 47.1% at cutoff points of 0.1, 0.37, 0.57, and 0.66, respectively. Conclusion: The WR-5 min can be considered as a potential TIC index in DCE-MRI for the diagnosis of malignant cervical lymphadenopathies.