Accuracy of computed tomography and magnetic resonance imaging in the detection of lymph node involvement in cervix carcinoma

Lymphnodes status in cervical carcinoma is important in therapeutic planning, and the role of Computed Tomography (CT) and Magnetic Resonance (MR) is controversial: this paper aims to evaluate their accuracy in diagnosing nodal metastases in patients with cervical carcinoma. We reviewed, retrospectively and blindly, CT and MR of 62 patients, before surgical lymphnode resection: 45 of these patients had pre-surgical chemotherapy. Lymphnodes were defined metastatic by CT and MRI when larger than 1 cm short axis. Both diagnoses by the original routine reports and by a second blind expert were compared with pathological reports. Results: combining the reading results of both observers CT showed a sensitivity of 64.6% and specificity of 93.3%; MRI a sensitivity of 72.9% and specificity of 93.1%. Positive Predictive Value was 50.8% for CT and 53% for MR, while Negative Predictive Value was 96% both for CT and MR. The expert Radiologist reviewing the films obtained better results. Inter-observer variability in the lower quadrants was high for each imaging technique (kappa for CT: 0.71; kappa for MRI: 0.84). Both imaging techniques showed similar screening accuracy in identifying nodal metastases. The radiologist's experience is important in determinig the performance of the imaging technique. Anyway, CT and MRI are only moderately sensitive for detection of nodal metastases and the clinical impact of their results in patient's management is limited.