This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
In a patient with hyperparathyroidism, Xray of the hand shows characteristic radiologic changes in which of the following ? 
Select and explain. 
A. Ulnar aspect of middle phalanx, B. Radial aspect of middle phalanx, C. Radial aspect of little finger, D. Ulnar aspect of little finger
B: Radial aspect of middle phalanx
Answer: B: Radial aspect of middle phalanx 
Explanation: In hyperparathyroidism there is subperiosteal bone resorption and it characteristically involves radial side of the middle phalanx of the middle finger, medial proximal tibia and lateral end of clavicle. Other radiologic features of hyperparathyroidism includes: Brown tumors: These are focal areas of bone resorption where the bone has been replaced by fibrous tissue and osteoclasts. In the spine, appearance of horizontal bands of sclerosis in the veebral bodies adjacent to the veebral end plates result in Rugger Jersey spine appearance. Chondrocalcinosis or calcification of the cailage Ref: Radiological Differential Diagnosis By Bhargava page 59. Skeletal Radiology: The Bare Bones By Felix S. Chew page 282.