MRI Whole-Body MRI, given its sensitivity to soft-tissue and bone marrow pathology, has high accuracy in diagnosing infection, including septic arthritis, osteomyelitis, pyomyositis, and discitis [42,43]. Like bone scan, whole-body MRI provides a total-body screen and is sensitive in detecting osseous abnormalities. As such, whole-body MRI may be an appropriate choice when there is suspicion for multifocal osteomyelitis [22,53,54]. While there is no single protocol for whole-body MRI, sequences may include the use of fluid-sensitive, T1-weighted, diffusion-weighted imaging, or chemical shift imaging, with or without the use of IV contrast [53,55]. CT Lower Extremity There is no relevant literature regarding the use of CT in the initial evaluation of acute limp with nonlocalized symptoms and concern for infection. Variant 4: Child up to age 5. Acute limp. Symptoms localized to the hip. Concern for infection. Initial imaging. If pain or physical examination appears localized to the hip, the diagnosis is septic arthritis until proven otherwise. Septic arthritis is the most common cause of acute severe monoarticular pain in children. It typically results from hematogenous and subsequent intra-articular spread of Staphylococcus aureus, with the hip being the most common site of involvement. In some cases, septic arthritis of the hip may be secondary to adjacent osteomyelitis [56]. Septic arthritis requires rapid diagnosis and intervention to prevent permanent damage to the joint [57]. In children with signs of infection and absence of a hip effusion, a diagnosis of pelvic osteomyelitis or pyomyositis should be considered [40]. Radiography Pelvis or Lumbar Spine There are limited data to support the use of radiographs in the initial evaluation of possible septic hip. The sensitivity and specificity of radiographs for the diagnosis of septic hip are low [58]. US Hips US of the hip allows quick and accurate diagnosis of a joint effusion and can be used to guide aspiration [59,60].
Acutely Limping Child Up To Age 5 PCAs. MRI Whole-Body MRI, given its sensitivity to soft-tissue and bone marrow pathology, has high accuracy in diagnosing infection, including septic arthritis, osteomyelitis, pyomyositis, and discitis [42,43]. Like bone scan, whole-body MRI provides a total-body screen and is sensitive in detecting osseous abnormalities. As such, whole-body MRI may be an appropriate choice when there is suspicion for multifocal osteomyelitis [22,53,54]. While there is no single protocol for whole-body MRI, sequences may include the use of fluid-sensitive, T1-weighted, diffusion-weighted imaging, or chemical shift imaging, with or without the use of IV contrast [53,55]. CT Lower Extremity There is no relevant literature regarding the use of CT in the initial evaluation of acute limp with nonlocalized symptoms and concern for infection. Variant 4: Child up to age 5. Acute limp. Symptoms localized to the hip. Concern for infection. Initial imaging. If pain or physical examination appears localized to the hip, the diagnosis is septic arthritis until proven otherwise. Septic arthritis is the most common cause of acute severe monoarticular pain in children. It typically results from hematogenous and subsequent intra-articular spread of Staphylococcus aureus, with the hip being the most common site of involvement. In some cases, septic arthritis of the hip may be secondary to adjacent osteomyelitis [56]. Septic arthritis requires rapid diagnosis and intervention to prevent permanent damage to the joint [57]. In children with signs of infection and absence of a hip effusion, a diagnosis of pelvic osteomyelitis or pyomyositis should be considered [40]. Radiography Pelvis or Lumbar Spine There are limited data to support the use of radiographs in the initial evaluation of possible septic hip. The sensitivity and specificity of radiographs for the diagnosis of septic hip are low [58]. US Hips US of the hip allows quick and accurate diagnosis of a joint effusion and can be used to guide aspiration [59,60].