Handheld ultrasound device in the assessment of the uterus and adnexa

Abstract

Abstract Purpose To assess the performance of the handheld ultrasound device (HUD) Butterfly-iQ compared to conventional transvaginal ultrasonography (US) in characterizing measurement and morphological aspects of the normal and abnormal uterus and adnexa. Methods This prospective accuracy study included 162 patients evaluated with transabdominal HUD, followed by conventional transvaginal US, between May 2021 and September 2022. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated to evaluate gynecological pelvic findings, with conventional US as the reference standard. The intraclass coefficient measured the reliability of pelvic findings measurements and the Kappa coefficient assessed the agreement of categorical variables between the two ultrasound modalities. Results For numerical variables, there was good to excellent agreement for uterine longitudinal diameter, uterine volume, endometrial thickness, fibroid larger diameter, crown–rump length, ovarian volume, and adnexal alteration maximum diameter, with intraclass coefficients ranging between 0.76 and 0.95. The sensitivity and specificity of HUD were 88.1% and 97.6%, respectively, for detecting uterine volume larger than 160 cm³, 84.4% and 99.7% for fibroids larger than 20 mm, and 68.7% and 95.9% for adnexal masses larger than 30 mm. Regarding the evaluation of small structures, HUD showed sensitivity and specificity of 12.5% and 99.3% for identifying intracavitary contents, 22.9% and 99.7% for fibroids smaller than 20 mm, and 33.3% and 98.5% for adnexal alterations smaller than 30 mm. Kappa coefficients for differentiating the position of the uterus, the location of the fibroids, and the type of adnexal mass were 0.68, 0.78, and 0.84, respectively. The data included ten cases of early pregnancy. The sensitivity and specificity were 100% for identifying intrauterine and adnexal pregnancies, and 66.7 and 100%, respectively, for characterizing images compatible with ovular remains. Conclusion Transabdominal HUD Butterfly-iQ and transvaginal conventional US demonstrated good to excellent agreement in measuring pelvic findings. HUD performed well in identifying early pregnancy, and gynecological pelvic conditions such as fibroids larger than 20 mm but exhibited poor performance in identifying small alterations of the uterus and adnexa.