J Korean Radiol Soc.  1994 May;30(5):943-946.

CT Evaluation of Sacroiliitis' Differentiation of Infectious Sacroiliitis versus Ankylosing Spondylitis

• Yoon Y
• Lee SU
• Ryu KN
• Park GY

Abstract

PURPOSE
To determine the characteristic CT findings of infectious sacroiliitis and ankylosing spondylitis. MATERIAL AND METHOD: We retrospectively reviewd CT findings in 10 patients with infectious sacroiliitis confirmed by culture and clinical follow ups and in 5 patients with ankylosing spondylitis by HLA-B27 typing. Mean ages were 30 years in ankylosing spondylitis and 29 years in infectious sacroiliits. CT scans were obtained with GE 9800 or Toshiba 900-S scanner. We analyzed CT findings in regard to the morphology and the degree of bone erosion, and the adjacent soft tissue change. RESULT: All cases of ankylosing spondylitis had bilateral and asymmetic bone erosion, predominantly in ilium, showing subchondral sclerosis on ilium. Infectious sacroiliitis showed unilateral involvement and soft tissue swelling in 10 cases and abscess in 5 cases.
CONCLUSION
We concluded that CT was useful in the differentiation between infectious sacroiliitis and ankylosing spondylitis.

MeSH Terms

Abscess
Follow-Up Studies
HLA-B27 Antigen
Humans
Ilium
Retrospective Studies
Sacroiliitis*
Sclerosis
Spondylitis, Ankylosing*
Tomography, X-Ray Computed
HLA-B27 Antigen