Role of Magnetic Resonance Imaging and Apparent Diffusion Coefficient at 3T in Distinguishing between Adenocarcinoma of the Uterine Cervix and Endometrium

Background: To determine whether magnetic resonance imaging (MRI) and apparent diffusioncoefficient (ADC) are able to distinguish between adenocarcinomaoriginating from the uterine cervix and endometrium.Methods: Institutional review board approval and informed consent were obtained.From May 2006 to June 2008, 29 women 25-73 years old (mean age, 50.3years) with a cervical biopsy yielding adenocarcinoma were enrolled for 3-TMR study with the imaging pulse-sequence protocol of T2-weighted imaging(T2WI) and dynamic contrast-enhanced (DCE) MRI and diffusion-weightedMRI (DWI, b = 0, 1000 sec/mm2). The extent and shapes of the tumor andADC values were evaluated by two radiologists retrospectively. Surgicalhistopathology served as the reference standard of the tumor origin from thecervix (n = 22) or endometrium (n = 7). The Mann-Whitney U test was usedfor statistical comparison and receiver operating characteristic (ROC) analysiswas used to obtain optimal ADC cut off values.Results: A longitudinal shape occurred significantly more frequently in endometrialcancer, and an oval shape was more frequently found in cervical cancer (p =0.011). Mean ADC values were significantly lower in endometrial cancer(76.6 x 10–5 mm2/sec) than in cervical cancer (96.9 x 10–5 mm2/sec).Receiver operating characteristic analysis yielded an optimal ADC cutoffvalue of 70 x 10–5 mm2/sec to distinguish cervical cancer from endometrialcancer.Conclusion: MRI may distinguish between most uterine adenocarcinoma originating fromthe cervix and endometrium using distinctive characteristics found on T2WIand DCE. When tumors show an ambiguous morphology, the ADC value ofthe tumor may be helpful for further differentiation.