aseptische Knochennekrose des Kniegelenks

Teenager with

leukemia and pancytopenia and knee pain. Sagittal T1 (left) and STIR (right) MRI without contrast of the knee show a large knee joint effusion along with well demarcated serpiginous lesions in the distal femur and proximal tibia that on STIR images demonstrate the double line sign.The diagnosis was avascular necrosis of the knee.

Teenager with

acute lymphocytic leukemia on steroids with knee pain. AP (above left) and lateral (above right) radiographs of the knee shows a serpiginous sclerotic lesion in the distal femur. Coronal T1 MRI without contrast of the knee (below left) shows the lesion in the distal femur to be defined by a focal serpentine low signal line with fatty center (reactive interface line) while coronal T2 MRI (below right) shows the lesion in the distal femur to be defined by a serpentine outer dark line and an inner bright line (double line sign).The diagnosis was avascular necrosis of the knee.