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
Which is the most reliable investigation in diagnosing a case of Spinal TB? 
Select and explain. 
A. X ray, B. CT guided biopsy, C. MRI, D. Mantouxtest
C: MRI
Answer: C: MRI 
Explanation: MRI is the imaging technique of choice in diagnosing spinal TBespecially in detecting spinal cord compression or cauda equina. Spinal TB: Spine is involved in 40% cases of skeletal TB. In children the most common site of skeletal TB is upper thoracic spine and in adults lower thoracic and upper lumbar veebrae are frequently affected. Ref: Harrison's Principles of Internal Medicine, 18th Edition chapter 165.