Presentation
Referred for a follow-up of a renal stone on the right.
Patient Data



Bilateral subchondral sclerosis of the anterosuperior aspects of both femoral heads, larger on the right side, highly suggestive of avascular necrosis, for further assessment by MRI scan.
The urinary tract examination and rest of abdomen and pelvic organs were normal, apart from four millimeters non-obstructive stone at the right lower calyx.



Bilateral femoral head serpiginous signal abnormalities are seen in the anterosuperior aspect of the head slightly larger in the right side findings indicating avascular necrosis.
The overlying cortex appears intact, no obvious crescent sign.
No significant joint effusion, or periarticular soft-tissue edema.
Sacroiliac joints appear unremarkable.
No pelvis masses or signal abnormality in the gluteal muscles.
Small irregular mixed signal intensity is seen in the deep subcutaneous fat overlying the left gluteal muscles due to previous IM injection (injection granuloma).
Case Discussion
This patient was referred for follow-up of a renal stone on the right. Upon image acquisition, both femoral heads demonstrated sclerosis which required further evaluation by MRI and confirmed findings of avascular necrosis.