The influence of the b‐value combination on apparent diffusion coefficient based differentiation between malignant and benign tissue in cervical cancer

Purpose:

To analyze the influence of different b‐value combinations on apparent diffusion coefficient (ADC)‐based differentiation of known malignant and benign tissue in cervical cancer patients.

Materials and Methods:

A total of 35 patients with stage IB1, IB2, IIA cervical cancer underwent a 3.0T MRI scan prior to radical hysterectomy and pelvic lymph node dissection. Conventional T1‐ and T2‐weighted sequences and a diffusion‐weighted sequence (b = 0, 150, 500, 1000 seconds/mm²) were performed. Regions‐of‐interest (ROI) were drawn on ADC maps derived from five different b‐value combinations (0, 500; 0, 150, 500; 0, 1000; 0, 150, 500, 1000; 150, 500, 1000 seconds/mm²). The influence of the b‐value combination on ADC‐based differentiation of benign and malignant tissue was analyzed using receiver‐operating‐characteristics curves.

Results:

For all b‐value combinations, ADCs were significantly lower (P < 0.001) in cervical malignancies (1.15 ± 0.21·10^?3; 1.10 ± 0.21·10^?3; 0.97 ± 0.18·10^?3; 0.97 ± 0.23·10^?3 and 0.85 ± 0.18·10^?3 mm²/second respectively to the aforementioned b‐value combinations) than in benign cervix (2.08 ± 0.31·10^?3; 2.00 ± 0.29·10^?3; 1.62 ± 0.23·10^?3; 1.54 ± 0.21·10^?3 and 1.42 ± 0.22·10^?3 mm²/second respectively). The diagnostic accuracy was high for all b‐value combinations and without statistical differences between the combinations.

Conclusion:

ADC‐based differentiation of benign from malignant cervical tissue is independent of the tested b‐value combinations. The results support the inclusion and possible pooling of studies using different b‐value combinations in meta‐analyses on ADC‐based tissue differentiation in cervical cancer. J. Magn. Reson. Imaging 2010;32:376–382. © 2010 Wiley‐Liss, Inc.