Although the effectiveness of magnetic resonance imaging (MRI) in depicting cervical carcinoma has been reported, whether MRI can detect early-stage or stage IB "occult"-type cervical carcinoma remained undetermined. We examined the correlation between MRI and pathologic findings in 38 stage I (IB 28 cases, IA 10 cases) cervical carcinoma patients, with special reference to the influence of desmoplastic stromal reaction around the tumor. The results demonstrated that the tumor was detected by MRI in none of stage IA patients but in 21 (75%) stage IB patients. The image was clearly demonstrated in 15 of 18 (83%) tumors of more than 2 cm in diameter and in 6 of 10 (60%) tumors of 2 cm or less. The tumor image was evident in 21 of 22 (95%) tumors with prominent (>200 micron) stromal reaction but in none of 6 tumors with minimal (</= 200 micron) stromal reaction. These findings suggest that MRI is not useful for the detection of stage IA tumors. In stage IB tumors, however, the stromal reaction rather than the size of the tumor may influence the tumor's image in MRI.