An innovative diagnostic ultrasound method for carpal tunnel syndrome was proposed and compared between carpal tunnel syndrome patients and healthy volunteers.

Inclusion Criteria:

• CTS patients were required to have subjective symptoms of numbness, tingling pain, or dysesthesia over the median nerve innervated area of the involved hand.
• Patients should have positive response in either Tinel's test or Phalen's test during physical examination
• Evidence of median neuropathy at wrist level in NCS.
• Control subjects should have neither symptoms nor signs of CTS along with no abnormal findings in electrodiagnostic study of the median nerve and the ulnar nerve across the wrist joint.

Exclusion Criteria:

• Age younger than 20 years old
• Electrodiagnostic evidence of ulnar neuropathy at the wrist level
• Previous trauma or surgery history of hand
• Medical history of hypothyroidism, diabetes mellitus, uremia, rheumatoid arthritis, amyloidosis, and acromegaly
• Pregnancy

CTS patients were recruited from the Physical Medicine and Rehabilitation Department of Taipei Tzu Chi hospital.

Healthy subjects were recruited from hospital staff, health volunteers and their friends.