Contrast-Enhanced Ultrasound Imaging of Uterine Disorders: A Systematic Review

Abstract

Uterine disorders are often presented with overlapping symptoms. The microvasculature holds specific information important for diagnosing uterine disorders. Conventional sonography is an established diagnostic technique in gynecology, but is limited by its inability to image the microvasculature. Contrast-enhanced ultrasound (CEUS), is capable of imaging the microvasculature by means of intravascular contrast agents; that is, gas-filled microbubbles. We provide a literature overview on the use of CEUS in diagnosing myometrial and endometrial disorders, that is, fibroids, adenomyosis, leiomyosarcomas and endometrial carcinomas, as well as for monitoring and enhancing the effectiveness of minimally invasive therapies. A systematic literature search with quality assessment was performed until December 2020. In total 34 studies were included, published between 2007 and 2020.The results entail a description of contrast-enhancement patterns obtained from healthy tissue and from malignant and benign tissue; providing a first base for potential diagnostic differentiation in gynecology. In addition it is also possible to determine the degree of myometrial invasion in case of endometrial carcinoma using CEUS. The effectiveness of minimally invasive therapies for uterine disorders can safely and accurately be assessed with CEUS. In conclusion, the abovementioned applications of CEUS are promising and it is worth further exploring its full potential for gynecology by designing innovative and methodologically high-quality clinical studies.

Keywords: contrast-enhanced ultrasound; imaging; microvasculature; systematic review; uterine disorders.

Figure 1.

Schematic representation of performing contrast-enhanced ultrasonography (CEUS) in gynecological setting. Step 1: intravenous injection of, for example, SonoVue ultrasound contrast agent. Injection is regulary done via a catheter and 5 mL of saline is flushed after the diluted sonovue is injected (a). Ultrasound contrast agents (microbubbles) remain intravascular (b). Step 2: transvaginal (or abdominal) ultrasound scan of the uterus (c). Providing a contrast-enhanced image of the uterus (d), showing hyper-enhancement of the myometrium (M) compared with the endometrium (E). Step 3: the CEUS image can be fully quantified, providing a time-intensity curve (e) from which parameters such as wash-in rate (1), peak intensity (2), and wash-out rate (3) can be obtained.

Figure 2.

Flow chart of literature search on articles reporting on CEUS for diagnosis of uterine disorder, monitoring, and/or enhancing of minimally invasive therapy.

Figure 3.

Normal uterus. Source. Adapted from Stoelinga et al. CEUS scan uterus: conventional gray-scale ultrasound image on the right and CEUS image on the left. CEUS image obtained 14 seconds after contrast injection shows initial enhancement of the (normal) myometrium.

Figure 4.

Subserosal fibroid (image made at our own institution). On the left CEUS image obtained 19 seconds after contrast injection, shows peripheral enhancement without enhancement in the central part of the fibroid. On the right conventional gray-scale ultrasound image of the same fibroid.