Renal osteodystrophy. AP view of the pelvis (a) in a 26-year-old female with secondary hyperparathyroidism that results in multiple, circumscribed, and expanded lucent areas compatible with brown tumors. Associated fracture deformity of the right femoral head and generalized demineralization. Prominent subchondral resorption and subtle widening, notably along the iliac surface of the right sacroiliac joint on axial CT image (b).