Three-dimensional turbo-spin-echo amide proton transfer-weighted mri for cervical cancer: A preliminary study

Abstract

Background: Amide proton transfer-weighted (APTw) imaging has shown great potential in the diagnosis of cancer, but has yet not been well studied in cervical cancer.

Purpose: To evaluate the image quality and clinical feasibility of APTw MRI for cervical cancer.

Study type: Prospective.

Population: In all, 75 patients with cervical lesions and 49 healthy volunteers.

Field strength/sequence: 3.0 T, 3D turbo spin echo (TSE) APTw sequence.

Assessment: Three radiologists, blinded to the clinical data, independently evaluated APTw image quality with a 5-point Likert scale on 64 patients with pathologically confirmed cervical cancer. APT values, calculated based on asymmetry of acquired Z-spectrum with respect to water frequency, using 3D turbo spin echo volume acquisition with B₀ correction, were independently measured by two radiologists, twice for each observer, on 52 cervical cancer lesions and 49 normal cervical stroma with a mean region of interest area of 638.6 mm² and 557.5 mm² , respectively.

Statistical tests: Interobserver agreement was evaluated by Kendall's W test. Intra- and interobserver interclass correlation coefficients (ICC) were computed. Student's t-test was used to compare the differences of APT values between cervical cancer and normal cervix; receiver operating characteristic analysis was performed.

Results: Most cases revealed good APTw image quality with excellent agreement (Kendall's W = 0.850, P < 0.001). APT values of cervical cancer and normal cervical stroma were 2.745 ± 0.065 and 1.853 ± 0.059, respectively, with a significant difference (P < 0.0001). Intraobserver ICCs were 0.963 and 0.960 for two readers. Interobserver ICC was 0.993. Area under the curve (AUC) for differentiating cervical cancer from normal cervical stroma was 0.927. The feasible threshold value for AUC was determined as 2.221 with sensitivity of 84.62% and specificity of 83.66%.

Data conclusion: 3D TSE APTw MRI is feasible in cervical cancer. Cervical cancer showed significantly higher APT values than normal cervix.

Level of evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1318-1325.

Keywords: amides; cervical cancer; magnetic resonance imaging; protons.