Novel T2 Mapping for Evaluating Cervical Cancer Features by Providing Quantitative T2 Maps and Synthetic Morphologic Images: A Preliminary Study

Background: The application value of T₂ mapping in evaluating cervical cancer (CC) features remains unclear.

Purpose: To investigate the role of T₂ values in evaluating CC classification, grade, and lymphovascular space invasion (LVSI) in comparison to apparent diffusion coefficient (ADC), and to compare synthetic T₂ -weighted (T₂ W) images calculated from T₂ values to conventional T₂ W images for CC staging.

Study type: Retrospective.

Population: Sixty-three patients with histopathologically confirmed CC.

Field strength/sequence: 3T, conventional T₂ W turbo spin-echo, diffusion-weighted echo-planar, and accelerated T₂ mapping sequence.

Assessment: T₂ and ADC values between different pathological features of CC were compared. The diagnostic accuracies of conventional and synthetic T₂ W images in staging were also compared.

Statistical tests: Parameters were compared using an independent t-test, Wilcoxon signed-rank test, and the chi-square test. Receiver operating characteristic analysis was performed.

Results: The T₂ values varied significantly between well/moderately differentiated and poorly differentiated tumors ([92.8 ± 9.5 msec] vs. [83.8 ± 9.5 msec], P < 0.05) and between LVSI-positive and LVSI-negative CC ([82.2 ± 8.2 msec] vs. [93.9 ± 9.1 msec], P < 0.05). The ADC values showed a significant difference for grade ([0.76 ± 0.10 × 10^-3 mm² /s] vs. [0.65 ± 0.11 × 10^-3 mm² /s], P < 0.05) and no difference for LVSI status ([0.71 ± 0.11× 10^-3 mm² /s] vs. [0.73 ± 0.12× 10^-3 mm² /s], P = 0.472). There was no significant difference in T₂ and ADC values between squamous cell carcinoma and adenocarcinoma (P = 0.378 and P = 0.661, respectively). In MRI staging, the conventional and synthetic T₂ W images resulted in a similar accuracy (71% vs. 68%, P = 0.698).

Data conclusion: The accelerated T₂ mapping sequence may facilitate grading and staging of CC by providing quantitative T₂ maps and synthetic T₂ W images in one acquisition. T₂ values may be superior to ADC in predicting LVSI.

Level of evidence: 2 TECHNICAL EFFICACY STAGE: 2 J. MAGN. RESON. IMAGING 2020;52:1859-1869.