DOI: 10.1148/rg.265055712
Peripheral Neuropathies of the Median, Radial, and Ulnar Nerves: MR Imaging Features1
Gustav Andreisek, MD,
David W. Crook, MD,
Doris Burg, MD,
Borut Marincek, MD and
Dominik Weishaupt, MD
1 From the Institute for Diagnostic Radiology, Department of Medical Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich, Switzerland (G.A., D.W.C., B.M., D.W.); and Division of Hand, Plastic and Reconstructive Surgery, Department of Surgery, University Hospital (Academic Medical Center), Zurich, Switzerland (D.B.). Received June 13, 2005; revision requested July 15 and received August 18; accepted August 26. All authors have no financial relationships to disclose.
View larger version (31K):
[in a new window]
|
Figure 1. In A, the schematic provides an anterior view of the course of the median nerve (1) along the elbow, through the two heads of the pronator teres muscle (2), and into the forearm. B is a close-up detail of the most common site of pronator syndrome, where the nerve courses between the humeral head (2a) and the ulnar head (2b) of the muscle.
|
|
View larger version (106K):
[in a new window]
|
Figure 2a. Pronator syndrome in a 58-year-old man after repeated pronation-supination stress from snow shoveling. (a) Axial T1-weighted SE MR image (repetition time msec/echo time msec, 560/9) at a middle level in the forearm shows normal volume and normal signal intensity of the proximal forearm muscles (1 = pronator teres, 2 = flexor carpi radialis, 3 = palmaris longus, 4 = flexor digitorum superficialis, 5 = flexor pollicis longus, 6a = radial part of the flexor digitorum profundus, 6b = ulnar part of the flexor digitorum profundus) and normal signal intensity of the radius (R) and ulna (U). (b) Corresponding T2-weighted fat-suppressed fast SE MR image (4340/106; echo train length, eight) demonstrates increased signal intensity indicative of edema in all of the muscles that are innervated by the median nerve. The ulnar part of the flexor digitorum profundus muscle, which is innervated by the ulnar nerve, is unaffected.
|
|
View larger version (105K):
[in a new window]
|
Figure 2b. Pronator syndrome in a 58-year-old man after repeated pronation-supination stress from snow shoveling. (a) Axial T1-weighted SE MR image (repetition time msec/echo time msec, 560/9) at a middle level in the forearm shows normal volume and normal signal intensity of the proximal forearm muscles (1 = pronator teres, 2 = flexor carpi radialis, 3 = palmaris longus, 4 = flexor digitorum superficialis, 5 = flexor pollicis longus, 6a = radial part of the flexor digitorum profundus, 6b = ulnar part of the flexor digitorum profundus) and normal signal intensity of the radius (R) and ulna (U). (b) Corresponding T2-weighted fat-suppressed fast SE MR image (4340/106; echo train length, eight) demonstrates increased signal intensity indicative of edema in all of the muscles that are innervated by the median nerve. The ulnar part of the flexor digitorum profundus muscle, which is innervated by the ulnar nerve, is unaffected.
|
|
View larger version (25K):
[in a new window]
|
Figure 3. Schematic provides an anterior view of the course of the anterior interosseous nerve (1), which arises from the median nerve (2) in the forearm.
|
|
View larger version (143K):
[in a new window]
|
Figure 4a. Complete anterior interosseous nerve syndrome in a 44-year-old man with weakness of the flexor muscles of the thumb and the second and third fingers. (a, b) Axial T1-weighted SE MR images (440/10) at proximal (a) and distal (b) levels of the forearm show moderate fatty atrophy in the flexor pollicis longus muscle (1 in a), in the radial aspect of the flexor digitorum profundus muscle (2 in a), and in the pronator quadratus muscle (3 in b). R = radius, U = ulna. (c, d) T2-weighted fast SE MR images (5160/98; echo train length, 10), at the same proximal (c) and distal (d) levels as a and b, depict increased signal intensity in the three muscles.
|
|
View larger version (115K):
[in a new window]
|
Figure 4b. Complete anterior interosseous nerve syndrome in a 44-year-old man with weakness of the flexor muscles of the thumb and the second and third fingers. (a, b) Axial T1-weighted SE MR images (440/10) at proximal (a) and distal (b) levels of the forearm show moderate fatty atrophy in the flexor pollicis longus muscle (1 in a), in the radial aspect of the flexor digitorum profundus muscle (2 in a), and in the pronator quadratus muscle (3 in b). R = radius, U = ulna. (c, d) T2-weighted fast SE MR images (5160/98; echo train length, 10), at the same proximal (c) and distal (d) levels as a and b, depict increased signal intensity in the three muscles.
|
|
View larger version (150K):
[in a new window]
|
Figure 4c. Complete anterior interosseous nerve syndrome in a 44-year-old man with weakness of the flexor muscles of the thumb and the second and third fingers. (a, b) Axial T1-weighted SE MR images (440/10) at proximal (a) and distal (b) levels of the forearm show moderate fatty atrophy in the flexor pollicis longus muscle (1 in a), in the radial aspect of the flexor digitorum profundus muscle (2 in a), and in the pronator quadratus muscle (3 in b). R = radius, U = ulna. (c, d) T2-weighted fast SE MR images (5160/98; echo train length, 10), at the same proximal (c) and distal (d) levels as a and b, depict increased signal intensity in the three muscles.
|
|
View larger version (111K):
[in a new window]
|
Figure 4d. Complete anterior interosseous nerve syndrome in a 44-year-old man with weakness of the flexor muscles of the thumb and the second and third fingers. (a, b) Axial T1-weighted SE MR images (440/10) at proximal (a) and distal (b) levels of the forearm show moderate fatty atrophy in the flexor pollicis longus muscle (1 in a), in the radial aspect of the flexor digitorum profundus muscle (2 in a), and in the pronator quadratus muscle (3 in b). R = radius, U = ulna. (c, d) T2-weighted fast SE MR images (5160/98; echo train length, 10), at the same proximal (c) and distal (d) levels as a and b, depict increased signal intensity in the three muscles.
|
|
View larger version (112K):
[in a new window]
|
Figure 5a. Incomplete anterior interosseous nerve syndrome in a 30-year-old woman with isolated weakness of the flexor pollicis longus and pronator quadratus muscles. (a, b) Axial T1-weighted SE MR images (340/15) obtained at proximal (a) and distal (b) levels in the forearm show a normal appearance of the flexor pollicis longus muscle (1 in a) and moderate fatty atrophy (arrows in b) of the pronator quadratus muscle (2 in b). R = radius, U = ulna. (c, d) Corresponding T2-weighted fat-suppressed fast SE MR images (3620/89; echo train length, 12), at the same proximal (c) and distal (d) levels as a and b, depict increased signal intensity in both muscles, a finding indicative of subacute denervation.
|
|
View larger version (120K):
[in a new window]
|
Figure 5b. Incomplete anterior interosseous nerve syndrome in a 30-year-old woman with isolated weakness of the flexor pollicis longus and pronator quadratus muscles. (a, b) Axial T1-weighted SE MR images (340/15) obtained at proximal (a) and distal (b) levels in the forearm show a normal appearance of the flexor pollicis longus muscle (1 in a) and moderate fatty atrophy (arrows in b) of the pronator quadratus muscle (2 in b). R = radius, U = ulna. (c, d) Corresponding T2-weighted fat-suppressed fast SE MR images (3620/89; echo train length, 12), at the same proximal (c) and distal (d) levels as a and b, depict increased signal intensity in both muscles, a finding indicative of subacute denervation.
|
|
View larger version (107K):
[in a new window]
|
Figure 5c. Incomplete anterior interosseous nerve syndrome in a 30-year-old woman with isolated weakness of the flexor pollicis longus and pronator quadratus muscles. (a, b) Axial T1-weighted SE MR images (340/15) obtained at proximal (a) and distal (b) levels in the forearm show a normal appearance of the flexor pollicis longus muscle (1 in a) and moderate fatty atrophy (arrows in b) of the pronator quadratus muscle (2 in b). R = radius, U = ulna. (c, d) Corresponding T2-weighted fat-suppressed fast SE MR images (3620/89; echo train length, 12), at the same proximal (c) and distal (d) levels as a and b, depict increased signal intensity in both muscles, a finding indicative of subacute denervation.
|
|
View larger version (106K):
[in a new window]
|
Figure 5d. Incomplete anterior interosseous nerve syndrome in a 30-year-old woman with isolated weakness of the flexor pollicis longus and pronator quadratus muscles. (a, b) Axial T1-weighted SE MR images (340/15) obtained at proximal (a) and distal (b) levels in the forearm show a normal appearance of the flexor pollicis longus muscle (1 in a) and moderate fatty atrophy (arrows in b) of the pronator quadratus muscle (2 in b). R = radius, U = ulna. (c, d) Corresponding T2-weighted fat-suppressed fast SE MR images (3620/89; echo train length, 12), at the same proximal (c) and distal (d) levels as a and b, depict increased signal intensity in both muscles, a finding indicative of subacute denervation.
|
|
View larger version (123K):
[in a new window]
|
Figure 6a. Carpal tunnel syndrome in a 14-year-old female patient with a wrist trauma–related fracture of the capitate bone. Electrodiagnostic testing revealed a complete conduction block of the median nerve at the level of the carpal tunnel. (a) Coronal T2-weighted fat-suppressed fast SE MR image (3500/100; echo train length, 12) of the wrist shows a fracture of the capitate bone (arrow) without dislocation. (b) Axial T1-weighted SE MR image (540/ 10) at the level of the carpal tunnel depicts moderate bowing of the flexor retinaculum (small arrows) and normal size of the median nerve (large arrow). (c) Axial T2-weighted fast SE MR image (4200/ 100; echo train length, 12) at the same level as b depicts increased signal intensity of the median nerve (arrow), a finding consistent with carpal tunnel syndrome.
|
|
View larger version (121K):
[in a new window]
|
Figure 6b. Carpal tunnel syndrome in a 14-year-old female patient with a wrist trauma–related fracture of the capitate bone. Electrodiagnostic testing revealed a complete conduction block of the median nerve at the level of the carpal tunnel. (a) Coronal T2-weighted fat-suppressed fast SE MR image (3500/100; echo train length, 12) of the wrist shows a fracture of the capitate bone (arrow) without dislocation. (b) Axial T1-weighted SE MR image (540/ 10) at the level of the carpal tunnel depicts moderate bowing of the flexor retinaculum (small arrows) and normal size of the median nerve (large arrow). (c) Axial T2-weighted fast SE MR image (4200/ 100; echo train length, 12) at the same level as b depicts increased signal intensity of the median nerve (arrow), a finding consistent with carpal tunnel syndrome.
|
|
View larger version (118K):
[in a new window]
|
Figure 6c. Carpal tunnel syndrome in a 14-year-old female patient with a wrist trauma–related fracture of the capitate bone. Electrodiagnostic testing revealed a complete conduction block of the median nerve at the level of the carpal tunnel. (a) Coronal T2-weighted fat-suppressed fast SE MR image (3500/100; echo train length, 12) of the wrist shows a fracture of the capitate bone (arrow) without dislocation. (b) Axial T1-weighted SE MR image (540/ 10) at the level of the carpal tunnel depicts moderate bowing of the flexor retinaculum (small arrows) and normal size of the median nerve (large arrow). (c) Axial T2-weighted fast SE MR image (4200/ 100; echo train length, 12) at the same level as b depicts increased signal intensity of the median nerve (arrow), a finding consistent with carpal tunnel syndrome.
|
|
View larger version (89K):
[in a new window]
|
Figure 7a. Carpal tunnel syndrome in a 54-year-old man with a fibrolipomatous hamartoma of the median nerve. (a) Axial T1-weighted SE MR image (380/10) at the level of the hook of the hamate shows enlargement of the median nerve, with hypointense nerve fascicles (arrow) surrounded by fibroadipose tissue (arrowheads). (b) Coronal contrast-enhanced T1-weighted fat-suppressed SE MR image (460/20) depicts entrapment of the median nerve within the carpal tunnel (arrows).
|
|
View larger version (126K):
[in a new window]
|
Figure 7b. Carpal tunnel syndrome in a 54-year-old man with a fibrolipomatous hamartoma of the median nerve. (a) Axial T1-weighted SE MR image (380/10) at the level of the hook of the hamate shows enlargement of the median nerve, with hypointense nerve fascicles (arrow) surrounded by fibroadipose tissue (arrowheads). (b) Coronal contrast-enhanced T1-weighted fat-suppressed SE MR image (460/20) depicts entrapment of the median nerve within the carpal tunnel (arrows).
|
|
View larger version (25K):
[in a new window]
|
Figure 8. Schematic shows a posterior view of the course of the radial nerve through the elbow, forearm, and hand. The radial nerve (1) divides at the level of the elbow into the superficial radial nerve (2) and the posterior interosseous nerve (3). In posterior interosseous nerve syndrome, the most common site of radial nerve compression is where the nerve penetrates the supinator muscle (4).
|
|
View larger version (143K):
[in a new window]
|
Figure 9a. Posterior interosseous nerve syndrome in a 27-year-old woman with weakness of the extensor muscles of the hand. (a) Axial T1-weighted SE MR image (320/10) in the proximal part of the forearm shows a moderate loss of volume in the muscles (1 = abductor pollicis longus, 2 = extensor digitorum, 3 = extensor digiti minimi, 4 = extensor carpi ulnaris, 5 = extensor pollicis brevis and longus). R = radius, U = ulna. (b) Corresponding T2-weighted STIR MR image (repetition time msec/echo time msec/inversion time msec, 4840/54/150) depicts edema in the muscles, all of which are innervated by the posterior interosseous nerve.
|
|
View larger version (127K):
[in a new window]
|
Figure 9b. Posterior interosseous nerve syndrome in a 27-year-old woman with weakness of the extensor muscles of the hand. (a) Axial T1-weighted SE MR image (320/10) in the proximal part of the forearm shows a moderate loss of volume in the muscles (1 = abductor pollicis longus, 2 = extensor digitorum, 3 = extensor digiti minimi, 4 = extensor carpi ulnaris, 5 = extensor pollicis brevis and longus). R = radius, U = ulna. (b) Corresponding T2-weighted STIR MR image (repetition time msec/echo time msec/inversion time msec, 4840/54/150) depicts edema in the muscles, all of which are innervated by the posterior interosseous nerve.
|
|
View larger version (115K):
[in a new window]
|
Figure 10a. Ulnar neuritis in a 67-year-old man with numbness in the ulnar aspect of the palm and in the fingers. (a) Axial CT image shows an osteophyte in the medial aspect of the olecranon, at the level of the ulnar sulcus (arrow). (b) Corresponding axial T2-weighted STIR MR image (4200/54/150) depicts increased signal intensity in the ulnar nerve (arrow), a finding indicative of focal neuritis.
|
|
View larger version (126K):
[in a new window]
|
Figure 10b. Ulnar neuritis in a 67-year-old man with numbness in the ulnar aspect of the palm and in the fingers. (a) Axial CT image shows an osteophyte in the medial aspect of the olecranon, at the level of the ulnar sulcus (arrow). (b) Corresponding axial T2-weighted STIR MR image (4200/54/150) depicts increased signal intensity in the ulnar nerve (arrow), a finding indicative of focal neuritis.
|
|
View larger version (143K):
[in a new window]
|
Figure 11a. Cubital tunnel syndrome in a 44-year-old man with pain in the forearm while playing the transverse flute. Axial T1-weighted SE MR image (500/16) (a) and corresponding axial T2-weighted fat-suppressed SE MR image (5340/58) (b) depict normal muscle volume but high signal intensity in the flexor carpi ulnaris (1 in a) and flexor digitorum profundus (2 in a) muscles, respectively. Increased signal intensity in the ulnar nerve in b is indicative of focal neuritis (arrow). R = radius, U = ulna.
|
|
View larger version (139K):
[in a new window]
|
Figure 11b. Cubital tunnel syndrome in a 44-year-old man with pain in the forearm while playing the transverse flute. Axial T1-weighted SE MR image (500/16) (a) and corresponding axial T2-weighted fat-suppressed SE MR image (5340/58) (b) depict normal muscle volume but high signal intensity in the flexor carpi ulnaris (1 in a) and flexor digitorum profundus (2 in a) muscles, respectively. Increased signal intensity in the ulnar nerve in b is indicative of focal neuritis (arrow). R = radius, U = ulna.
|
|
View larger version (42K):
[in a new window]
|
Figure 12. Schematic provides a palmar view of the course of the ulnar nerve (1) as it passes through the Guyon canal, which is located between the pisiform bone (2) and the hook of the hamate (3). In addition to the ulnar nerve, the Guyon canal contains the ulnar artery (4), fat, and, occasionally, veins. 5 = median nerve, 6 = radial artery.
|
|
View larger version (105K):
[in a new window]
|
Figure 13a. Ulnar nerve compression due to a ganglion cyst in the hand of a 57-year-old man. (a) Axial intermediate-weighted MR image (3500/40) at the level of the hook of the hamate (H) shows a hyperintense ganglion cyst (*). (b) Corresponding axial T1-weighted SE MR image (420/11) demonstrates the location of the ganglion cyst (*) next to the hook of the hamate (H) and near the ulnar nerve (arrow). (c) Axial intermediate-weighted MR image (3500/40) at the level of the metacarpal bones shows increased signal intensity in the adductor pollicis (small arrows) and in all the interosseous muscles (large arrows). (d) Sagittal T1-weighted SE MR image (540/12) at the level of the hook of the hamate (H) depicts the ulnar nerve (large arrow) and its bifurcation into a superficial sensory branch (small arrow) and a deep motor branch (arrowhead).
|
|
View larger version (101K):
[in a new window]
|
Figure 13b. Ulnar nerve compression due to a ganglion cyst in the hand of a 57-year-old man. (a) Axial intermediate-weighted MR image (3500/40) at the level of the hook of the hamate (H) shows a hyperintense ganglion cyst (*). (b) Corresponding axial T1-weighted SE MR image (420/11) demonstrates the location of the ganglion cyst (*) next to the hook of the hamate (H) and near the ulnar nerve (arrow). (c) Axial intermediate-weighted MR image (3500/40) at the level of the metacarpal bones shows increased signal intensity in the adductor pollicis (small arrows) and in all the interosseous muscles (large arrows). (d) Sagittal T1-weighted SE MR image (540/12) at the level of the hook of the hamate (H) depicts the ulnar nerve (large arrow) and its bifurcation into a superficial sensory branch (small arrow) and a deep motor branch (arrowhead).
|
|
View larger version (74K):
[in a new window]
|
Figure 13c. Ulnar nerve compression due to a ganglion cyst in the hand of a 57-year-old man. (a) Axial intermediate-weighted MR image (3500/40) at the level of the hook of the hamate (H) shows a hyperintense ganglion cyst (*). (b) Corresponding axial T1-weighted SE MR image (420/11) demonstrates the location of the ganglion cyst (*) next to the hook of the hamate (H) and near the ulnar nerve (arrow). (c) Axial intermediate-weighted MR image (3500/40) at the level of the metacarpal bones shows increased signal intensity in the adductor pollicis (small arrows) and in all the interosseous muscles (large arrows). (d) Sagittal T1-weighted SE MR image (540/12) at the level of the hook of the hamate (H) depicts the ulnar nerve (large arrow) and its bifurcation into a superficial sensory branch (small arrow) and a deep motor branch (arrowhead).
|
|
View larger version (168K):
[in a new window]
|
Figure 13d. Ulnar nerve compression due to a ganglion cyst in the hand of a 57-year-old man. (a) Axial intermediate-weighted MR image (3500/40) at the level of the hook of the hamate (H) shows a hyperintense ganglion cyst (*). (b) Corresponding axial T1-weighted SE MR image (420/11) demonstrates the location of the ganglion cyst (*) next to the hook of the hamate (H) and near the ulnar nerve (arrow). (c) Axial intermediate-weighted MR image (3500/40) at the level of the metacarpal bones shows increased signal intensity in the adductor pollicis (small arrows) and in all the interosseous muscles (large arrows). (d) Sagittal T1-weighted SE MR image (540/12) at the level of the hook of the hamate (H) depicts the ulnar nerve (large arrow) and its bifurcation into a superficial sensory branch (small arrow) and a deep motor branch (arrowhead).
|
|
View larger version (84K):
[in a new window]
|
Figure 14a. Multifocal motor neuropathy in a 45-year-old female patient with nonspecific muscle weakness of the right arm. (a, b) Coronal fat-suppressed STIR image (5300/32/150) (a) and corresponding T1-weighted SE image (440/8) (b) show increased signal intensity and thickening, respectively, of the right brachial plexus (arrows). (c, d) Axial T2-weighted fast SE image (4000/100; echo train length, 12) (c) and corresponding T1-weighted SE image (620/9) (d) depict edema and atrophy of the supinator muscle (large arrow). Parts of the extensor muscles (small arrows in c) also are involved. R = radius, U = ulna.
|
|
View larger version (105K):
[in a new window]
|
Figure 14b. Multifocal motor neuropathy in a 45-year-old female patient with nonspecific muscle weakness of the right arm. (a, b) Coronal fat-suppressed STIR image (5300/32/150) (a) and corresponding T1-weighted SE image (440/8) (b) show increased signal intensity and thickening, respectively, of the right brachial plexus (arrows). (c, d) Axial T2-weighted fast SE image (4000/100; echo train length, 12) (c) and corresponding T1-weighted SE image (620/9) (d) depict edema and atrophy of the supinator muscle (large arrow). Parts of the extensor muscles (small arrows in c) also are involved. R = radius, U = ulna.
|
|
View larger version (110K):
[in a new window]
|
Figure 14c. Multifocal motor neuropathy in a 45-year-old female patient with nonspecific muscle weakness of the right arm. (a, b) Coronal fat-suppressed STIR image (5300/32/150) (a) and corresponding T1-weighted SE image (440/8) (b) show increased signal intensity and thickening, respectively, of the right brachial plexus (arrows). (c, d) Axial T2-weighted fast SE image (4000/100; echo train length, 12) (c) and corresponding T1-weighted SE image (620/9) (d) depict edema and atrophy of the supinator muscle (large arrow). Parts of the extensor muscles (small arrows in c) also are involved. R = radius, U = ulna.
|
|
View larger version (101K):
[in a new window]
|
Figure 14d. Multifocal motor neuropathy in a 45-year-old female patient with nonspecific muscle weakness of the right arm. (a, b) Coronal fat-suppressed STIR image (5300/32/150) (a) and corresponding T1-weighted SE image (440/8) (b) show increased signal intensity and thickening, respectively, of the right brachial plexus (arrows). (c, d) Axial T2-weighted fast SE image (4000/100; echo train length, 12) (c) and corresponding T1-weighted SE image (620/9) (d) depict edema and atrophy of the supinator muscle (large arrow). Parts of the extensor muscles (small arrows in c) also are involved. R = radius, U = ulna.
|
|
View larger version (141K):
[in a new window]
|
Figure 15a. Schwannoma of the ulnar nerve in a 59-year-old woman. Axial T2-weighted fast SE MR image (4060/90) (a) and corresponding contrast-enhanced T1-weighted fat-suppressed fast spoiled gradient-recalled-echo MR image (205/3) (b) demonstrate a fusiform mass (arrow) at the location of the ulnar nerve in the forearm.
|
|
View larger version (110K):
[in a new window]
|
Figure 15b. Schwannoma of the ulnar nerve in a 59-year-old woman. Axial T2-weighted fast SE MR image (4060/90) (a) and corresponding contrast-enhanced T1-weighted fat-suppressed fast spoiled gradient-recalled-echo MR image (205/3) (b) demonstrate a fusiform mass (arrow) at the location of the ulnar nerve in the forearm.
|
|
View larger version (99K):
[in a new window]
|
Figure 16a. Histologically proved intramuscular lipoma in a 59-year-old man with swelling in the proximal part of the forearm and numbness in the ulnar aspect of the hand. (a, b) Axial T1-weighted SE MR image (460/14) (a) and T2-weighted fast SE MR image (2740/88; echo train length, 12) (b) at a proximal level in the forearm show an atypical lipoma within the flexor digitorum profundus muscle (1). The mass laterally displaces the flexor digitorum super-ficialis (2), flexor carpi ulnaris (3), palmaris longus (4), and flexor carpi radialis (5) muscles, as well as the ulnar nerve (arrow). R = radius, U = ulna. (c) Corresponding contrast-enhanced T1-weighted fat-suppressed SE MR image (420/14) shows inhomogeneous contrast enhancement of the lipoma.
|
|
View larger version (113K):
[in a new window]
|
Figure 16b. Histologically proved intramuscular lipoma in a 59-year-old man with swelling in the proximal part of the forearm and numbness in the ulnar aspect of the hand. (a, b) Axial T1-weighted SE MR image (460/14) (a) and T2-weighted fast SE MR image (2740/88; echo train length, 12) (b) at a proximal level in the forearm show an atypical lipoma within the flexor digitorum profundus muscle (1). The mass laterally displaces the flexor digitorum super-ficialis (2), flexor carpi ulnaris (3), palmaris longus (4), and flexor carpi radialis (5) muscles, as well as the ulnar nerve (arrow). R = radius, U = ulna. (c) Corresponding contrast-enhanced T1-weighted fat-suppressed SE MR image (420/14) shows inhomogeneous contrast enhancement of the lipoma.
|
|
View larger version (105K):
[in a new window]
|
Figure 16c. Histologically proved intramuscular lipoma in a 59-year-old man with swelling in the proximal part of the forearm and numbness in the ulnar aspect of the hand. (a, b) Axial T1-weighted SE MR image (460/14) (a) and T2-weighted fast SE MR image (2740/88; echo train length, 12) (b) at a proximal level in the forearm show an atypical lipoma within the flexor digitorum profundus muscle (1). The mass laterally displaces the flexor digitorum super-ficialis (2), flexor carpi ulnaris (3), palmaris longus (4), and flexor carpi radialis (5) muscles, as well as the ulnar nerve (arrow). R = radius, U = ulna. (c) Corresponding contrast-enhanced T1-weighted fat-suppressed SE MR image (420/14) shows inhomogeneous contrast enhancement of the lipoma.
|
|
Copyright © 2006 by the Radiological Society of North America.
