[About Gonad Protection Based on Ovarian Position in Hip Plain Radiography]

In gonad protection, it is difficult to identify the position from the body surface during shielding because the position and size of the ovary vary from individual to individual, and it is not possible to evaluate whether the protective equipment is correctly placed at the position of the ovary. Therefore, the position of the ovary with respect to the pelvis was clarified, and the effectiveness of gonad protection in the front and side of the hip joint was evaluated.

From the image of the pelvis taken with an MRI device, the inner and outer edges of the ovary, the upper and lower edges and the long and short axes of the pelvis, and the depth of the ovary were measured, and the position of the ovary was calculated based on the ratio of the ovary to the pelvis. A pelvic schema was created, and the position of the ovary was synthesized on the schema. In addition, the shielding rate was calculated when lead-containing rubber for the protection of the gonads was used.

In front of the pelvis, the ovaries were present throughout the pelvic cavity. On the anterior surface, placing the shield on the caudal side up to the line connecting the centers of the left and right femoral heads had a shielding effect of about 88%. On the lateral side, shielding the pubic upper limbs from the ischial body could reduce the exposure of the unhealthy ovaries by 99%. However, when the gonad protection was placed at the height of the line connecting the anterior superior iliac spines, the shielding rate from the left and right ovarian distribution was about 13%, so the disadvantage of using the protective equipment was greater.

For gonad protection, the presence or absence of use should be judged by using the shielding rate according to the shape of the protective equipment as an index.