The sonographic evaluation of tubal patency with stimulated acoustic emission imaging

Objectives Experimental and clinical data suggest that insonation of echo-enhancing contrast agents with high acoustic power produces disintegration of microbubbles, resulting in a phenomenon called stimulated acoustic emission (SAE). The purpose of this study was to investigate whether SAE might be detected by transvaginal sonography and whether this technique may be useful in the assessment of tubal patency by hysterosalpingo-contrast sonography (SAE-HyCoSy). Methods Patients booked for X-ray hysterosalpingography (HSG) for infertility evaluation also received SAE-HyCoSy. The order of the two procedures was established in each patient by randomization after placement of a transcervical balloon catheter. For SAE-HyCoSy, the ultrasound contrast medium Levovist was injected, with the acoustic power set at the maximum level permitted on ultrasound machines employing dedicated algorithms. Conventional HSG was performed for comparison. Results Seventy-seven Fallopian tubes were examined in 41 patients. In all cases it was possible to obtain the SAE phenomenon. In 10 tubes (13%) proximal filling was not observed by both SAE-HyCoSy and HSG. In the remaining 67 tubes, free spill from the distal end of the lumen was demonstrated in 96% of cases (64/67) with SAE-HyCoSy and in 97% of cases (65/67) with HSG. Disagreement between the two techniques was observed in five tubes only, with a Cohen's kappa coefficient of 0.76 (95% confidence interval, 0.56-0.96). Conclusion SAE techniques were successfully applied to HyCoSy and allowed the visualization of the free spill of contrast agent into the peritoneal cavity in the majority of cases. SAE-HyCoSy showed good agreement with HSG in this preliminary study.