US Area of Interest US may be useful for the detection of synovial thickening or joint effusion. However these are not specific to septic arthritis. US limitations include difficulty imaging deeper structures, deep larger joints (such as the shoulder or hip), an inability to evaluate metal implants, and a lack of sensitivity and specificity to findings such as fistulous tracts, subperiosteal fluid collections, and periosteal thickening [28,33]. WBC Scan and Sulfur Colloid Scan Area of Interest The addition of a sulfur colloid scan is useful in cases in which results are equivocal for septic loosening or osteomyelitis because leukocytes may accumulate in marrow adjacent to orthopedic implants [36,44]. However, the addition of a sulfur colloid bone marrow scan to a WBC scan does not increase the accuracy for detection of septic arthritis. The addition of SPECT/CT is recommended in positive studies to aid in the differentiation of soft tissue infection from osteomyelitis. WBC Scan Area of Interest Systematic reviews by Verberne et al [36] and Van der Bruggen et al [45] both describe significant variability in specificity and sensitivity of WBC scan ability to diagnosis infection of orthopedic implants. This is likely due to Suspected Osteomyelitis, Septic Arthritis variability in scanning technique and criteria used for diagnosis of prosthetic related infection. In a study of 215 patients, Trevail et al [34] reported that a WBC scan had a sensitivity of 80% and a specificity >99%. The addition of SPECT/CT is recommended in positive studies to aid in the differentiation of soft tissue infection from osteomyelitis. Variant 6: Suspected soft tissue infection. History of puncture wound with possible retained foreign body. Radiographs normal. Next imaging study.
Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. US Area of Interest US may be useful for the detection of synovial thickening or joint effusion. However these are not specific to septic arthritis. US limitations include difficulty imaging deeper structures, deep larger joints (such as the shoulder or hip), an inability to evaluate metal implants, and a lack of sensitivity and specificity to findings such as fistulous tracts, subperiosteal fluid collections, and periosteal thickening [28,33]. WBC Scan and Sulfur Colloid Scan Area of Interest The addition of a sulfur colloid scan is useful in cases in which results are equivocal for septic loosening or osteomyelitis because leukocytes may accumulate in marrow adjacent to orthopedic implants [36,44]. However, the addition of a sulfur colloid bone marrow scan to a WBC scan does not increase the accuracy for detection of septic arthritis. The addition of SPECT/CT is recommended in positive studies to aid in the differentiation of soft tissue infection from osteomyelitis. WBC Scan Area of Interest Systematic reviews by Verberne et al [36] and Van der Bruggen et al [45] both describe significant variability in specificity and sensitivity of WBC scan ability to diagnosis infection of orthopedic implants. This is likely due to Suspected Osteomyelitis, Septic Arthritis variability in scanning technique and criteria used for diagnosis of prosthetic related infection. In a study of 215 patients, Trevail et al [34] reported that a WBC scan had a sensitivity of 80% and a specificity >99%. The addition of SPECT/CT is recommended in positive studies to aid in the differentiation of soft tissue infection from osteomyelitis. Variant 6: Suspected soft tissue infection. History of puncture wound with possible retained foreign body. Radiographs normal. Next imaging study.