Using amide proton transfer to identify cervical squamous carcinoma/adenocarcinoma and evaluate its differentiation grade

To explore the possibility of using amide proton transfer-weighted imaging (APTWI) for the identification and diagnosis of cervical squamous carcinoma (CSC), cervical adenocarcinoma (CA) and different levels of CSC. Seventy-six patients with newly diagnosed uterine cervical cancer (UCC) were studied prior to treatment, including 20 with poorly differentiated (Grade 3) CSC, 23 with moderately differentiated (Grade 2) CSC, 17 with well-differentiated (Grade 1) CSC, and 16 with CA (13 with poorly differentiated (Grade 3) CA and 3 with moderately differentiated (Grade 2) CA). Differences in the magnetization transfer ratio at 3.5 ppm (MTRasym (3.5 ppm)) were identified between CSC and CA and between high-level (Grade 3) CSC and low-level (Grade 2 and Grade 1) CSC, as well as among all three grades of CSC differentiation. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic thresholds and performance of the parameters. Spearman correlation analysis was used to examine the correlation between the MTRasym (3.5 ppm) and histological grade. The MTRasym (3.5 ppm) in CA was higher than that in CSC (P = 0.001). The MTRasym (3.5 ppm) in high-level CSC was higher than that in low-level CSC (P = 0.001). The MTRasym (3.5 ppm) was positively correlated with the grade of CSC differentiation (r = 0.498, P = 0.001). The MTRasym (3.5 ppm) in Grade 3 CSC was higher than that in Grade 2 and Grade 1 CSC (P = 0.02/0.01). No significant difference in the MTRasym (3.5 ppm) was found between Grade 2 CSC and Grade 1 CSC (P = 0.173). The area under the ROC curve (AUC) for the MTRasym (3.5 ppm) in distinguishing CSC and CA was 0.779, with a cut-off, sensitivity, and specificity of 2.97%, 60.0% and 82.5%, respectively. The AUC for distinguishing high-/low-level CSC was 0.756, with a cut-off, sensitivity, and specificity of 3.29%, 68.8% and 83.3%, respectively. APTWI may be a useful technique for the identification and diagnosis of CSC, CA and different levels of CSC, which may have an important impact on clinical strategies for treating patients with UCC.