In patients with suspected or confirmed septic arthritis, femoral neck aspiration performed at the time of incision and drainage was noted to improve diagnosis of concurrent osteomyelitis compared with preoperative MRI alone [63]. Although the bulk of literature on image-guided joint aspiration in the pediatric population refers to the hip joint, aspiration could also be considered in other joints. Although some studies have shown no significant difference in sensitivity and specificity in the diagnosis of osteomyelitis or septic arthritis with or without the use of gadolinium-based contrast agents, contrast has been shown to improve detection of abscesses [32,33]. Decreased femoral head enhancement on early postcontrast imaging has been noted as a reliable feature of septic arthritis not seen in transient synovitis [34]. In addition, MRI has been shown to be useful in evaluating for concurrent musculoskeletal infection. In assessment of septic arthritis, the majority of pediatric patients with septic arthritis were noted on MRI to have infection beyond the joint space, although this may vary based on population factors such as geography [7,46,60,65,66]. Conversely, in metaphyseal osteomyelitis, over 50% in one study were noted on MRI to have concomitant joint effusions, 75% of which were confirmed to be septic arthritis [67]. Osteomyelitis or Septic Arthritis-Child Repeat MRI of the area of interest performed for worsening or persistent symptoms resulted in clinical management changes in 21% of patients [64]. In one study on septic elbow arthritis, 40% of patients did not respond to antibiotic therapy and were noted on subsequent elbow MRI to have concurrent osteomyelitis [60]. MRI Extremity Area of Interest In one study, a large field-of-view MRI was performed to encompass both lower extremities rather than the area of concern [38].
Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. In patients with suspected or confirmed septic arthritis, femoral neck aspiration performed at the time of incision and drainage was noted to improve diagnosis of concurrent osteomyelitis compared with preoperative MRI alone [63]. Although the bulk of literature on image-guided joint aspiration in the pediatric population refers to the hip joint, aspiration could also be considered in other joints. Although some studies have shown no significant difference in sensitivity and specificity in the diagnosis of osteomyelitis or septic arthritis with or without the use of gadolinium-based contrast agents, contrast has been shown to improve detection of abscesses [32,33]. Decreased femoral head enhancement on early postcontrast imaging has been noted as a reliable feature of septic arthritis not seen in transient synovitis [34]. In addition, MRI has been shown to be useful in evaluating for concurrent musculoskeletal infection. In assessment of septic arthritis, the majority of pediatric patients with septic arthritis were noted on MRI to have infection beyond the joint space, although this may vary based on population factors such as geography [7,46,60,65,66]. Conversely, in metaphyseal osteomyelitis, over 50% in one study were noted on MRI to have concomitant joint effusions, 75% of which were confirmed to be septic arthritis [67]. Osteomyelitis or Septic Arthritis-Child Repeat MRI of the area of interest performed for worsening or persistent symptoms resulted in clinical management changes in 21% of patients [64]. In one study on septic elbow arthritis, 40% of patients did not respond to antibiotic therapy and were noted on subsequent elbow MRI to have concurrent osteomyelitis [60]. MRI Extremity Area of Interest In one study, a large field-of-view MRI was performed to encompass both lower extremities rather than the area of concern [38].