Fast dynamic contrast enhanced mr imaging of cervical carcinoma

Abstract

The first pass phase of contrast material is most important to study vascularization and perfusion of tissue and can be studied using dynamic magnetic resonance (MR) imaging. The purpose of this prospective study was to evaluate the usefulness of pre-contrast vs. post-contrast and fast dynamic MR imaging in the preoperative staging of cervical carcinomas. To assess the normal onset of enhancement of the uterus and cervix 15 volunteers underwent dynamic MR imaging. Forty-two consecutive patients with invasive cervical cancer underwent preoperative evaluation using MR imaging. The results of the MR examinations were correlated with clinical (FIGO) staging under anesthesia (n = 42) and with histopathological findings after operation (n = 26). The staging results of precontrast T1-weighted and T2-weighted turbo spin-echo (TSE) MR images, pre-contrast MR images plus post-contrast enhanced (two-dimensional fast low angle shot (FLASH 2-D) post contrast), pre-contrast MR images plus post-contrast enhanced plus fast dynamic enhanced (single slice turbo fast low angle shot (turbo FLASH)) MR images compared to histopathology (n = 26) were 77%, 81%, and 85%, respectively. The improvement was statistically not significant. The result of MR staging compared to clinical staging (n = 42) with pre-contrast MR images was correct in 79% of the cases. Pre-contrast MR images combined with post-contrast MR images did not significantly improve staging accuracy (83%). Pre-contrast plus post-contrast plus fast dynamic MR imaging improved staging to 91%. However, the improvement was only statistically significant for one reader (p = 0.01), whereas the improvement of the second reader was not significant (p = 0.07). The single slice turbo FLASH images showed enhancement of all squamous cell carcinomas (n = 32) with an average onset of 5 seconds (range 4–8 seconds during the first 45 seconds of bolus injection of gadolinium. The normal cervix showed enhancement with an average of 10 seconds (range 6–14 seconds). FLASH 2-D post-contrast images showed less intense enhancement of the cervical tumors with respect to the parametria and other surrounding structures. Fast dynamic MR imaging and to a lesser degree post-contrast MR imaging showed a higher level of confidence than pre-contrast MR. Fast dynamic MRI compared with clinical staging (n = 42) was correct in 91% (38/42) and to histopathology in 85% (22/26). Comparison of clinical staging with histopathology was 85% (22/26). In conclusion, fast dynamic MR imaging is superior to post-contrast and pre-contrast MR imaging and is at least as good as clinical staging in the evaluation of cervical carcinoma.