Real-time sonoelastography of the cervix: tissue elasticity of the normal and abnormal cervix

Abstract

Rationale and objectives: First study to investigate the basic tissue elastic properties of the cervix in pre- and postmenopausal healthy women and to compare these normal findings with the results in a group of patients with focal pathology of the cervix.

Materials and methods: A total of 113 patients underwent transvaginal ultrasound, among them 24 with cervical pathology. The real-time elastography (Hitachi) information was color-coded and superimposed on the B-mode scan. The elastography images were analyzed by means of a software tool to identify thresholds for the colors red (soft), blue (hard), and green (medium hard), and the percentages of the three colors of the total area were determined. The results were correlated with age. In addition, scans were evaluated subjectively on an analogue scale from 1 (definitely normal) to 5 (definitely abnormal). Statistical analysis was performed using Anova, Wilcoxon's test, and Pearson's correlation.

Results: Computer-assisted generation of the color spectrum showed green to be predominant in both the normal group (67+/-13 %) and in the group with cervical pathology (64+/-15 %) without a significant difference between both groups (p=>0.05). Significant differences (p<0.05) in the blue color spectrum (hard tissue) were found between the 13 cervical tumor patients (34+/-15 %) and the normal group (26+/-13 %) but not between the CIN patients and normal women (19+/-12 %) (p>0.05). Subjective tumor characterization also showed significant differences (p<0.05) among the groups and good correlation with the histologic diagnosis (r2=0.744). There were no significant changes in color distribution with patient age (p>0.05).

Conclusion: Computer-assisted and subjective evaluation of cervical elastography allows differentiation of malignancy from normal findings. CIN cannot be identified with this modality. Elastographically, cervical tissue is of medium hardness and does not change with age.