CPMs presented as bubble (n=41), irregular (n=33), cystic (n=26) or small circular (n=31) cavities, with even (n=61) or uneven (n=70) thickness of the cavity wall.

• 共有泡样空洞 41枚 ,不规则空洞 3 3枚 ,囊样空洞 2 6枚 ,小环形空洞 3 1枚。 壁厚度均匀者 61枚 ,不均匀者 70枚。