School ager with catheter that infuses but does not draw back

Line study of a central venous catheter tip that has migrated out of the vessel
CXR from 1 month before (above) shows the tip of the catheter in a left-sided superior vena cava. Scout image from a line study (below left) shows the tip of the catheter has apparently migrated out of the left-sided superior vena cava. Injection of the catheter (below right) shows contrast extravasating into the mediastinum.

The diagnosis was migration of the catheter tip out of the vessel into the mediastinum.

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.