Toddler with limp who won’t bear weight on right leg

Radiograph and MRI of diskitis / osteomyelitis
Lateral radiograph of the lumbar spine shows loss of height of the L3-L4 intervertebral disc space. Sagittal T2 MRI of the lumbar spine shows (right top) loss of normal bright signal of the L3-L4 intervertebral disc and an epidural mass just posterior to the L4 vertebral body. Axial T1 MRI with contrast at the L4 level shows the epidural mass to be right sided and to also involve the right psoas muscle.

The diagnosis was osteomyelitis / diskitis.