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 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.

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.

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.

Preschooler with back pain

MRI of osteomyelitis of the spine
Coronal T1 MRI without contrast of the lumbar spine (left above) shows areas of low signal intensity on the right side of the L4 and L5 vertebral bodies and a right-sided paraspinal mass all of which enhance after the administration of contrast (right above). Axial T2 MRI through the L5 vertebral body (below) shows high signal intensity in the right side of the vertebral body and in the right paraspinal mass. The disk spaces are not involved.

The diagnosis was osteomyelitis.