FIGURE 1.

The chronological change in the transvaginal ultrasound images in hemorrhagic ovarian cysts. A, A normal right ovary with a small follicle on the 25th day of the menstrual cycle. B, An anechoic mass with a size of 48 × 41 mm on the 11th day of the menstrual cycle. C, An anechoic mass with a small follicle with a size of 40 × 28 mm on the 14th day of the menstrual cycle. D, A mass showing a solid pattern with a size of 62 × 40 mm on the 16th day of the menstrual cycle. E, A mass showing distinct solid parts with a size of 90 × 68 mm on the 6th day of the menstrual cycle. F, A mass showing a clear division into cystic and solid parts with a size of 73 × 72 mm on the 14th day of the next menstrual cycle. G, A mass mixed with dense echo and echo‐free spaces with a size of 55 × 37 mm on the 21st day of the menstrual cycle. H, A sponge‐like mass with a size of 38 × 39 mm on the 28th day of the menstrual cycle. I, A sponge‐like mass with a size of 34 × 22 mm on the 5th day of the menstrual cycle. J, A sponge‐like mass with a size of 22 × 17 mm on the 12th day of the next menstrual cycle. K, A normal right ovary after the mass disappeared on the 19th day of the next menstrual cycle. D indicates the first detection of HOC sonograms, which was defined as Day 0. A, B, and C are 33, 5, and 2 days before HOC was detected. D, E, F, G, H, I, J, and K are 18, 26, 33, 40, 47, 55, and 62 days after HOC was detected