Background and Aim: Endometriosis is a common gynecological problem. In recent years, it has been one of the main subjects of women's diseases. 5-15% of the premenopausal women are suffering from this disorder. During the past two decades, its incidence has been on the rise.

Material and Methods: This study was a retrospective study and included 60 patients with clinically suspected endometriosis who were candidates for laparoscopy. Transvaginal ultrasound and laparoscopy was performed for all of them. Data were collected using SPSS version 20 software and analyzed by sensitivity, specificity, positive predictive value, negative predictive value, and chi-square.

Result: In this study the mean age of the patients was 31.1 ± 4.97. We found a sensitivity of 100% for transvaginal ultrasound in the diagnosis of pelvic mass. The sensitivity and specificity of transvaginal ultrasound for the diagnosis of the bladder involvement were 50% and 100% respectively. The accuracy of the test to distinguish the two cases were 100% and 93%, respectively.

Conclusion: The results of this study showed that the transvaginal ultrasound can be safely used for the diagnosis of pelvic mass and its diagnostic value is equal to that of laparoscopy. It is less invasive and less expensive than laparoscopy. We obtained satisfactory results by using transvaginal method for detection of bladder involvement.

Keywords: Endometriosis, Transvaginal ultrasound, Laparoscopy, Sensitivity, Specificity.

Received: May 5, 2014      Accepted: Jul 28, 2014