Transvaginal Ultrasound for the Diagnosis of Adenomyosis: Systematic Review and Meta-Analysis

Adenomyosis is characterized by the presence of ectopic foci of endometrial glandular tissue and/or stroma within the myometrium. The diagnosis of adenomyosis is traditionally made through histologic evaluation of the postsurgical specimen. More recently, imaging with transvaginal ultrasound (TVUS) has been used for the preoperative diagnosis of adenomyosis. As yet, there is no consensus regarding the best imaging feature or combination thereof for the nonsurgical diagnosis of adenomyosis. This study systematically evaluated the literature in the last 10 years to determine the accuracy of 2-dimensional (2D) TVUS, different imaging features, enhancing methods such as 3-dimensional (3D) TVUS, elastography and color Doppler in the nonsurgical diagnosis of adenomyosis. A total of 8 studies were included. Pooled sensitivity and specificity for 2D TVUS for the diagnosis of adenomyosis for all combined imaging characteristics was 83.8% and 63.9%, respectively. Pooled sensitivity for 355 total patients with use of imaging feature of heterogeneous myometrium with 2D TVUS was highest (86.0%), and pooled specificity for 283 total patients with use of globular uterus was highest (78.1%). After including the "question mark" sign with other TVUS features, higher sensitivity and specificity, of 92% and 88%, respectively, were noted. For 3D TVUS, pooled sensitivity and specificity for all combined imaging characteristics was 88.9% and 56.0%, respectively. Poor definition of junctional zone showed the highest pooled sensitivity (86%) and the highest pooled specificity (56.0%) for the diagnosis of adenomyosis with 3D TVUS. There was no improvement in overall accuracy in 3D TVUS compared with 2D TVUS. Preliminary results of TVUS with color Doppler showed a high sensitivity and specificity for the differentiation between adenomyosis and myomas (95.6% and 93.4%, respectively). Also, TVUS elastography in 1 study showed an improvement in specificity (82.9%) compared with 2D TVUS (63.9%), albeit with comparable sensitivity. Larger studies are needed to advance our understanding of the different types of adenomyosis and their clinical impact.