Abstract
The aim of this study was to evaluate the usefulness of magnetic resonance imaging for the preoperative measurement of depth of tumor invasion in 45 patients with tongue cancers. The depth of tumor area as determined by MR imaging was compared with the area where the tumor was really invading in the histopathological section prepared from the corresponding surgical material.
Lesion detectability was compared among the following 3 types of image : T1-weighted spin echo imaging, T1WI-group; T2-weighted spin echo imaging, T2WI-group; enhanced MRI-group. The T2WI-group showed highest accuracy in detecting the tumor among the three groups. In each sample the tumor area detecting in the histopathological tissue sections was measured and size reduction rate through histopathological processing was calculated. The depth of corrected histopathological tumor area was calculated by revising with reduction rate. The depth of corrected histopathological tumor area showed statistically significant correlation with the depth of tumor area of MRI. Type of growth, mode of invasion did not show any significant difference between the classified groups. The correlation coefficient between tumor depth of MRI and histopathology showed significant value in the case where lympho-plasmocytic infiltration was slight or none. On the other hand, the correlation coefficient was not significant in the case where lympho-plasmocytic infiltration was marked or moderate. The present result suggests that the depth of tumor area diagnosed by MRI well correlates with actual tumor depth in generally, however, careful diagnosis is required when stromal lymphocyte infiltration is strong.
