MRI Evaluation of Local Extent of Carcinoma Cervix – Is Post Contrast Imaging Needed in Every Case?

Abstract

Introduction: Carcinoma cervix is widely prevalent among women in developing countries. Post contrast Magnetic Resonance Imaging (MRI) utilising spin echo T1 weighted sequence with fat suppression is widely practiced as part of evaluation of carcinoma cervix. However, it is unclear if such post contrast imaging provides any additional information other than adding to the cost of imaging. Aim: To find accuracy of T1 and T2 weighted non contrast MRI protocol in comparison with post contrast spin echo T1 weighted fat suppressed imaging in evaluating the local extent of the carcinoma cervix. Materials and Methods: A prospective study was conducted in the Department of Radiodiagnosis, JJM Medical College and Hospital, Davangere, Karnataka, India, between June 2016 and December 2016. A total of 45 females with a mean age of 50.7 years with biopsy proven cervical malignancy and predetermined clinical staging underwent MRI of pelvis. Prior to the scan, 10-15 ml of lignocaine jelly was instilled into the vagina. Sagittal T2 weighted images of the pelvis were acquired to identify the plane of the uterus and cervix. Axial and coronal imaging were planned perpendicular and parallel to the plane of cervix. Post contrast fat suppressed Spin Echo T1 weighted images were also obtained. Two radiologists evaluated the non contrast and contrast enhanced MR images of all patients separately. Interobserver variability and statistical significance was calculated. Results: There was 100% agreement between the two radiologists in interpreting non contrast scans and 91.1% interobserver agreement for post contrast images. Interruption of T2 hypointense cervical stroma with or without hyperintensity in adjacent parametrium, and interruption of the hypointense inner walls of urinary bladder and rectum could be more easily and reliably identified than the extension of enhancement outside the confines of the cervix. Four patients with a clinical staging of 1b and 2a who underwent surgery showed extension into parametrium on non contrast MRI image as well as peroperatively. In patients who had not underwent surgery, both the non contrast and post contrast MRI imaging findings were in agreement with each other. Twenty out of 45 cases showed pelvic nodes which were identified on both non contrast and post contrast images. Conclusion: Routine post contrast T1 weighted imaging provides no added advantage in comparison with non contrast T1 and T2 weighted imaging in evaluation of carcinoma cervix and need not be acquired routinely. However, only in selective cases with ambiguity on non contrast images, dynamic post contrast imaging may be used as a problem solving tool.

Keywords

• cervical mass
• dynamic contrast imaging
• figo staging
• parametrial infiltration