Keywords:
Inflammation, Infection, Arthritides, Technical aspects, Diagnostic procedure, Contrast agent-intravenous, PACS, MR-Functional imaging, MR, Musculoskeletal system, Musculoskeletal joint
Authors:
M. K. Kim, S.-H. Choi, H. Y. Lee ; Seoul/KR
DOI:
10.1594/ecr2011/C-2224
Results
For all 30 patients,
the study is comprised of 12 infectious lesions and 18 non-infectious lesions.
For 12 patients of infectious group,
three patients with cellulitis,
three patients with myositis,
two patients with synovitis,
two patients with osteomyelitis and two patients with septic arthritis.
In six patients,
the infectious process involved single knee joint,
four patients involved ankle joint and two patients involved the foot.
The final diagnoses,
proven surgically in 7 cases (Incision and drainage : 5 cases,
partial synovectomy : 1 case and amputation : 1 case) and 2 cases proven by joint fluid aspiration and culture study.
But 3 cases examined only bloody tests.
Dynamic Contrast-enhanced MR Imaging
The three parameter mathematical model used in earlier studies was fitted to the MR enhancement time-intensity curves using the equation [4].
The results showed that the maximal slope for the infectious group (mean:0.14,
SD:0.10) was steeper than that of the non-infectious group (mean:0.04,
SD:0.05) (P<0.05).
The T1⁄2max for the infectious group (mean:7.07,
SD:1.93) was shorter than that of the non-infectious group (mean:63.48,
SD:246.21) (P<0.05).
The peak value of enhancement for the infectious group (mean:1.25,
SD:0.57) was higher than that of the non-infectious group (mean:0.79,
SD:1.32) (P<0.05) (Fig 2).
In patients with infections,
there was a rapid and persistent enhancement,
but in normal controls,
there was slow and plateau of enhancement.
The enhancement of patients with infection was rapider and higher than those of normal controls (Fig 3).