T1 mapping in evaluation of clinicopathologic factors for rectal adenocarcinoma

Objective T1 mapping has been increasingly applied in the study of tumor. The purpose of this study was to evaluate the value of T1 mapping in evaluating clinicopathologic factors for rectal adenocarcinoma.Materials and methods Eighty-six patients with rectal adenocarcinoma confirmed by surgical pathology who underwent preoperative pelvic MRI were retrospectively analyzed. High-resolution T(2-)weighted imaging (T2WI), T1 mapping, and diffusion-weighted imaging (DWI) were performed. T1 and apparent diffusion coefficient (ADC) parameters were compared among different associated tumor markers, tumor grades, stages, and structure invasion statuses. A receiver operating characteristic (ROC) analysis was estimated.Results T1 value showed significant difference between high- and low-grade tumors ([1531.5 +/- 84.7 ms] vs. [1437.1 +/- 80.3 ms], P < 0.001). T1 value was significant higher in positive than in negative perineural invasion ([1495.7 +/- 89.2 ms] vs. [1449.4 +/- 88.8 ms], P < 0.05). No significant difference of T1 or ADC was observed in different CEA, CA199, T stage, N stage, lymphovascular invasions, extramural vascular invasion (EMVI), and circumferential resection margin (CRM) (P > 0.05). The AUC under ROC curve of T1 value were 0.796 in distinguishing high- from low-grade rectal adenocarcinoma. The AUC of T1 value in distinguishing perineural invasion was 0.637.Conclusion T1 value was helpful in assessing pathologic grade and perineural invasion correlated with rectal cancer.