Pediatric Imaging Pearl of the Week

The illustrated DDX can be found here.

Preschooler with left hip pain

Ultrasound of transient synovitis of the hip — Sagittal US of the hips shows a large anechoic fluid collection in the anterior recess of the left femur, which is not present in the right hip. This left hip effusion, when tapped under ultrasound guidance, returned clear fluid.

The diagnosis was transient synovitis of the hip.

Teenager with chronic right hip pain and acute left hip pain

Radiograph of Legg-Calve-Perthes disease and slipped capital femoral epiphysis — AP (above) and frogleg (below) radiographs of the pelvis shows the right femoral head to be flat and enlarged with femoral neck shortening. The left femoral epiphysis is slipped posteromedially.

The diagnosis was chronic right Legg-Calve-Perthes disease and left slipped capital femoral epiphysis.

Teenager with left hip pain

Radiograph and CT of slipped capital femoral epiphysis — AP radiograph of the pelvis shows a fracture through the left physeal growth plate causing the femoral epiphysis to sublux off of the femoral metaphysis. This is more clearly seen on the coronal 2D reconstruction CT of the pelvis.

The diagnosis was slipped capital femoral epiphysis.

Preschooler with left hip pain

Radiograph and ultrasound of septic arthritis of the hip — AP radiograph of the pelvis was unremarkable. Sagittal US of the hips shows a large anechoic fluid collection in the anterior recess of the left femur, which is not present in the right hip. This left hip effusion, when tapped under ultrasound guidance, returned green pus.

The diagnosis was septic arthritis of hip.

Teenager with left hip pain

Radiograph of parosteal osteosarcoma of the femur — AP and lateral radiographs of the left hip shows a poorly circumscribed, sclerotic, expansile lesion that appears to be attached to the cortex.

The diagnosis was parosteal osteosarcoma of the femur.

School ager with a left limp

Radiograph and nuclear medicine bone scan of osteomyelitis of the femur — AP radiograph of the pelvis was unremarkable. Nuclear medicine bone scan shows increased radiotracer uptake in the left femoral head and neck and proximal femur.

The diagnosis was osteomyelitis of the left femur.

School ager with right hip pain

Radiograph and CT of osteoid osteoma of the femur — AP radiograph of the pelvis shows a round lucent lesion in the right femoral neck. Coronal 2D reconstruction and axial CT without contrast of the pelvis shows the lesion to be centered in the cortex, to have a central calcification in a radiolucent nidus, and to be surrounded by reactive sclerosis. There is also a left hip effusion on the lower left CT image.

The diagnosis was osteoid osteoma of the femur.

Preschooler with bilateral hip pain

Radiograph of neuroblastoma bone metastases to the femur — AP radiograph of the femurs shows a mottled appearance to both femurs with multiple lytic lesions noted in the femurs with associated periosteal reaction, more prominent on the left than the right.

The diagnosis was metastases from neuroblastoma.

Infant with right hip pain

Radiograph of Langerhans Cell Histiocytosis of the femur — AP radiograph of the pelvis shows a well circumscribed lytic lesion in the proximal right femoral metaphysis without any associated periosteal reaction.

The diagnosis was Langerhans cell histiocytosis

Infant whose mother fell on her who has new left hip pain

Radiograph of acute femur fracture — AP radiograph of the femur shows a transverse lucency through the diaphysis of the femur without any associated periosteal reaction.

The diagnosis was an acute partially displaced femur fracture.

Teenager with right hip pain

Radiograph of Ewing Sarcoma — AP radiograph of the right hip shows a permeative appearance to the medullary portion of the proximal femur with cortical destruction and diffuse periosteal reaction.

The diagnosis was Ewing sarcoma.

Preschooler with right hip pain for 2 weeks

CT of perforated appendicitis — AP radiograph of the right femur was unremarkable. Coronal STIR MRI of the right hip and femur was unremarkable aside from incidental bright pelvic free fluid noted just above the bladder. Coronal 2D reconstruction from a CT with IV and oral contrast of the abdomen shows a large complex fluid collection containing air and a central calcification in the right lower quadrant which was lying next to the psoas muscle.

The diagnosis was perforated appendicitis with an abscess containing an appendicolith.

Our DDX For This Week Is

Pediatric Imaging Pearl of the Week

The illustrated DDX can be found here.

Preschooler with a right limp

US of transient synovitis of the hip — Sagittal US of the hips shows a large anechoic fluid collection in the anterior recess of the right femur, which is not present in the left hip. This right hip effusion, when tapped under ultrasound guidance, returned clear fluid.

The diagnosis was transient synovitis of hip.

Teenager with a right limp

Radiograph of slipped capital femoral epiphysis — Frogleg radiograph of the pelvis shows a fracture through the right physeal growth plate causing the femoral epiphysis to sublux off of the femoral metaphysis.

The diagnosis was slipped capital femoral epiphysis.

Toddler with a right limp

Radiograph of a septic hip — AP radiograph of the pelvis shows symmetrical ossification of the femoral epiphyses and normal acetabulae bilaterally. The right femoral epiphysis was felt to be displaced laterally in comparison to the left. A hip ultrasound showed a right hip joint effusion, which when tapped under ultrasound guidance returned pus.

The diagnosis was septic arthritis of hip.

Teenager with a limp after falling

Radiograph of osteosarcoma of the femur — AP and lateral radiographs of the right femur shows permeative cortical destruction throughout the diaphysis of the femur with associated diffuse sunburst periosteal reaction and a Codman’s triangle.

The diagnosis was osteosarcoma of the femur.

Preschooler with a limp for several weeks

Radiograph and CT scan and MRI scan of diskitis / osteomyelitis of the spine — Lateral radiograph of the spine shows anterior wedging of the T12 vertebral body and loss of height of the T12-L1 intervertebral disk space. Axial CT through T12 shows destruction of the vertebral body anteriorly and an associated paraspinal abscess forming between the aorta and the vertebral body. Sagittal T2 MRI (left), T1 MRI without contrast (middle) and T1 MRI with contrast (right) demonstrate more clearly the irregular contour of the inferior endplate of T12, the loss of height of the T12-L1 intervertebral disk space, and the loss of the normal bright signal within that disk space on T2 weighted-imaging.

The diagnosis was diskitis / osteomyelitis.

School ager with long-standing left limp and occasional fever

Radiograph of chronic osteomyelitis of the femur — AP radiograph of the proximal left femur shows a lucent lesion containing multiple septations that is associated with extensive cortical thickening and periosteal reaction. Percutaneous bone biopsy was performed.

The diagnosis was chronic osteomyelitis of the left femur.

Teenager who is a runner with a limp

Radiograph of stress fracture of the femur — AP and lateral radiographs of the femur show on the AP view a transverse non-displaced healing fracture through the distal femoral diaphysis that on the lateral view has periosteal reaction and marked cortical thickening along the posterior aspect of the femur.

The diagnosis was stress fracture of the femur.

Toddler born breech who is beginning to walk who was noted to have a left limp

Radiograph of developmental dysplasia of the hip — Frogleg radiograph of the pelvis shows markedly asymmetrical ossification of the femoral epiphyses, with the left femoral epiphysis smaller in size than the right femoral epiphysis. The left acetabulum is also more shallow than the right acetabulum and the left femoral epiphysis appears slightly subluxed laterally and superiorly.

The diagnosis was developmental dysplasia of the left hip.

Our DDX For This Week Is

Pediatric Imaging Pearl of the Week

The illustrated DDX can be found here.