“…[38][39][40][41] Bone tissues, on the other hand, have a higher density due to the significant presence of calcium, resulting in a CT value higher than 200 HU. 35,[38][39][40][41][42][43] Calcium ions, known for their excellent CT signals, are abundant in the human body, with approximately 60% of them being calcium-containing inorganic salts. Among these, bone salts primarily consist of calcium and phosphorus chemicals, distributed in the organic matter as crystalline hydroxyapatite and amorphous calcium phosphate.…”