CARPAL TUNEL SYNDROME ASSESMENT WITH MR IMAGING HAS ADVATAGES AS DETAILED IN THE PRESENTATION.

1. CARPAL TUNNEL SYNDROMEULTRASOUND AND MR FINDINGS Common compressive neuropathy Increase in the volume of the carpal tunnel or Reduction in the available space in the carpal tunnel leads to compression / mass effect over the median nerve MERCURY IMAGING INSTITUTE SCO 172-173 SEC 9C CHANDIGARH MERCURY IMAGING CENTRE SCO 16-17 SEC 20D CHANDIGARH

2. CARPAL TUNNEL Dedicated assesment of the CARPAL TUNNEL carried out at three levels Distal radioulnar joint Pisiform bone Hook of hammate. Fibro-osseous concave space in the volar aspect of the carpal bones and flexor retinaculum.flexorretinaculum is seen to extend from the scaphoid to tubercle of trapezium on one side and pisiform to hook of hamate on other side. Normal homogenous fat is appreciated in the carpal tunnel aling the dorsal aspect. MEDIAN NERVE

3. NORMAL CARPAL TUNNEL Flexor tendons are hypointense . Flexor retinaculum has hypointense signal with minimal volar bowing . Fat is appreciated normally in dorsal aspect of the tunnel. Median nerve has normal fasciculated, nonfaceted , non angulated appearance.

4. MEDIAN NERVE MEDIAN NERVE :It is normally placed in the volar and radial aspect of the tunnel. NORMAL APPEARANCE Oval with higher signal than adjacent flexor tendons . Non faceted , non angulated , Fascicular appearance is normal. Size decreases from Proximal to distal course in the carpal tunnel.

5. Some facts ........................... CARPAL TUNNEL SYNDROME COMMON COMPRESSIVE NEUROPATHY Focal / segmental thickening of the median nerve ( pseudoneuroma ) – compare size at distal radioulnar joint and at level of pissiform. Flatenning or angulation of the surface of the nerve in vicnity of the flexor tendons. Increased bowing ratio . Increased signal intensity of the median nerve. ( obstructed venous return with resultant nerve edema ). SYMPTOMS =Pain in thumb/ index finger and radial aspect of the Middle finger. Worse at night . Most common cause of the syndrome is tenosynovitis of the flexor tendons. ( overuse as in typists). Cardinal fetaures on MR imaging

6. Post op assesment ................. In case of failure Normal post op apperance after the release of the flexor retinaculum Retinaculum is not completely seen. Free ends of the retinaculum are appreciated with volar deviation. Contents of the carpal tunnel show volar deviation. Incomplete release of the flexor retinaculum appreciated as intact part of the flexor retinaculum . Low signal intensity fibrotic tissue in vicnity of the median nerve Persistant / recurrent mass Median nerve neuroma

7. VOLAR BOWING – Quantitative assesment for carpal tunnel syndrome VOLAR BOWING : Normal flexor retinaculum has minimal volar bowing. TH– Line drawn from tubercle of trapezium to hook of hammate. PD :The palmar displacement is line drawn perpendicular to TH and reaching till the flexor retinaculum …….. The ratio of PD/TH (15% is normal) . 14% TO 26% is taken as abnormal.

8. CASE REVIEW

9. Case of Rheumatoid arthritis with carpal tunnel syndrome. 40 YR FEMALE WITH Inflammatory arthritis ( RA) sequelaffecting Distal Radioulnar / Radiocarpal / intercarpal joint spaces, Articular / subarticular surfaces. ( synovial cysts, marginal erosions, synovial thickening ) Carpal tunnel syndrome. Edema in the carpal tunnel space , Volar bowing of the flexor Retinaculum , Flattening of the median nerve , Tenosynovitis.

10. BULKY MEDIAN NERVE WITH SIGNIFICANT VOLAR BOWING OF THE FLEXOR RETINACULUM.

11. FLUID ALONG FLEXOR TENDONS- TENOSYNOVITIS ONE OF THE COMMON CAUSES OF THE CARPAL TUNNEL SYNDROME

12. EROSION / DESTRUCTION ALONG THE ARTICULAR , SUBARTICULAR LOCATIONS INVOLVING CARPAL BONES , DISTAL RADIUS. APPRECIATED CHONDRAL THINNING , EROSIONS , SURFACE IRREGULARITY ALONG ARTICULAR MARGINS

14. CASE 2 – CARPAL TUNNEL SYNDROME 30 yr old female with MR findings supportive of CARPAL TUNNEL SYNDROME with important features as Tenosynovitis along flexor tendons. Bulky , indentated median nerve with relatively increased intrasubstcnace signal. Small articular / subarticular erosion / irregularities of the carpal bones. Synovial thickening of especially along the intercarpal joints. Synovial cysts as detailed in text above. To R/o INFLAMMATORY ARTHRITIS SEQUAEL ( RHEUMATOID ARTHRITIS) AS POSSIBILITY.

15. BULKY MEDIAN NERVE WITH SIGNIFICANT VOLAR BOWING OF THE FLEXOR RETINACULUM

16. SYNOVIAL CYSTS IN RELATION TO THE DORSAL ASPECT OF THE FLEXOR TENDONS.

17. ASSESMENT OF THE CARPAL TUNNEL WITH ULTRASOUND

18. FASCICULATED APPEARANCE OF THE MEDIAN NERVE ULTRASOUND – Non invasive , No radiation , cost effective , Good for corelation.

19. MEDIAN NERVE FLUID ALONG THE TENDONS IN THE CARPAL TUNNEL

20. MEDIAN NERVE FLUID ALONG THE TENDONS IN THE CARPAL TUNNEL

21. CARPAL TUNNEL SAGITTAL VIEW.

22. FLEXOR TENDONS IN THE CARPAL TUNNEL – SAGITTAL PLANE