Magnetic resonance imaging and radiographic findings of seal finger.
OBJECTIVE
To describe the magnetic resonance imaging (MRI) and radiographic findings of five patients with seal finger.


METHODS
The MR images and radiographs of five patients with seal finger were retrospectively evaluated. MRI was performed on four patients in the subacute phase, and follow-up imaging was done on one of them at 5 months. One patient had MRI only at a later stage 5 years after onset. Radiographs were taken three times in the subacute phase and once at a later stage. One patient had had seal finger in another finger previously.


RESULTS
Short-tau inversion-recovery (STIR) sequence showed extensive subcutaneous soft tissue edema in all four patients in the subacute phase and tenosynovitis of the flexion tendons in two cases. Three patients had edema in 2-3 phalanges, and effusion in the distal interphalangeal (DIP) joint was seen in one case. At the later stage, no signal pathology in soft tissues or bones was seen in STIR images. In the subacute phase, radiographs showed digital soft-tissue swelling in three patients, and one patient had a narrowed DIP joint, periarticular osteoporosis, and a periosteal reaction. At the later stage, flexion contracture of the finger was seen.


CONCLUSIONS
In addition to soft-tissue infection, seal finger causes bone marrow edema, tenosynovitis, and effusion in the interphalangeal joints visible as increased signal intensity in STIR images. Radiographs reveal periarticular osteoporosis with loss of cartilage in the subacute phase and flexion contracture at the later stage. MRI (STIR) allows more precise delineation of the inflammatory process compared to radiography.
Marjelund
S
S
Department of Radiology, Oulu University Hospital, Oulu, Finland. sari.marjelund@fimnet.fi
Tikkakoski
T
T
Isokangas
M
M
Räisänen
S
S
D000328:Adult; D000818:Animals; D000890:Anti-Infective Agents / Q000627:therapeutic use; D005383:Finger Injuries / Q000382:microbiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D046048:Seals, Earless / Q000382:microbiology*; D013717:Tenosynovitis / Q000382:microbiology*; D014946:Wound Infection / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000188:drug therapy
D000890:Anti-Infective Agents