Abstract: Objective To summarize the multimodal ultrasound imaging characteristics of circumscribed choroidal hemangioma (CCH), including two-dimensional ultrasound, color Doppler flow imaging, elastosonography, and contrast-enhanced ultrasound, and explore their significance in the diagnosis and differential diagnosis of CCH. Design Retrospective case series. Participants A total of 99 patients (100 eyes) with CCH were selected from the Department of Ophthalmology, Beijing Tongren Hospital from June 2016 to October 2024. Methods The multi-mode ultrasound imaging of CCH in all cases was retrospectively analyzed, including the image characteristics of two-dimensional ultrasound, color Doppler flow imaging, elastosonography and contrast-enhanced ultrasound. The detection rates of different positions and shapes of the tumor, internal echoes, special acoustic signs and blood flow signals in the tumor were counted. The tumor basal diameter and height were counted, and the height to base ratio was calculated. The elasticity score distribution of the tumors and the time-intensity curve of contrast agents in the tumors were analyzed. Main Outcome Measures Two dimensional ultrasound: location, shape, size, internal echo and special acoustic signs of CCH; Color Doppler flow imaging: blood flow in the tumor; Elastosonography: elasticity score of the tumor; Contrast enhanced ultrasound: time-intensity curve of contrast agent in tumor. Results The average age of 99 cases was (46.81±12.63) years old, including 61 males (62 eyes). Two dimensional ultrasound showed that 55% (55/100) of the tumors were located in the temporal side of the optic disc, accounting for the most. The tumors were all hemispherical in shape, 100% (100/100), 85% (85/100) had similar or higher echo than adjacent orbital tissue, and 95% (95/100) were uniform echo. No special acoustic signs such as hollowing out sign and choroidal excavation sign were found in all tumors. The diameter of the tumor base was (10.12±2.29) mm, the height was (3.47±1.25) mm, and the ratio of height to base was 0.34±0.06. The detection rate of secondary retinal detachment was 69% (69/100). Color Doppler flow imaging showed that blood flow signals were visible in all tumors, and 87% (87/100) of the tumors showed relatively rich blood flow signals. Elastosonography showed that the average elasticity score of tumors was 2.00±0.51, and 11% (11/100), 80% (80/100), 7% (7/100) and 2% (2/100) were scored 1, 2, 3 and 4, respectively. Contrast-enhanced ultrasound showed that the time-intensity curves of all tumors were fast-in and slow-out. Conclusion The ultrasound manifestations of CCH are mostly hemispherical solid protrusions, with uniform and higher echo. Color Doppler flow imaging often shows rich blood flow signals in the tumors, and the elasticity score is usually <3. Circumscribed choroidal hemangioma has a fast-in and slow-out time-intensity curve of contrast-enhanced ultrasound. The application of multimodal ultrasound imaging has important clinical value in the diagnosis and differential diagnosis of CCH.

Key words: Circumscribed choroidal hemangioma, Color Doppler ultrasound, Elastosonography, Contrast-enhanced ultrasound