 Hello, I am Dr. Suya Srivastav, JR3 Radiology. I am going to present a case series on MR and X-ray evaluation of osteonecrosis of femoral head. I have done this series under guidance of Dr. Ashutosh Chitness, Professor and HOD, and Dr. Gayathri Patil, Associate Professor, Department of Radiology, MGM Medical College in Hospital, Neve Mumbai. Now, osteonecrosis of the femoral head, previously known as avascular necrosis of the hip, is the most common site for osteonecrosis, presumably due to a combination of precarious blood supply and high loading when standing. The clinical presentation is pain in the region of the affected hip, high groin, and buttock. Now, the aim and objectives were to study the findings of MRI and X-ray of osteonecrosis of volatile femoral heads. MRI and X-ray PVH was performed in 30 patients referred to the Department of Radiology, MGM Medical College in Hospital, Neve Mumbai, in a period of one year with clinical suspicion of osteonecrosis of femoral head. Now, in this first case, who is a 38-year-old male, presented with bilateral hip pain more pronounced on the right side. We can see that there is right hip joint reduction. There is irregularity of the femoral head. And there is subchondral patchy sclerosis. Some degree of osteopenia is seen, left side appears unremarkable. On the MRI images, on the axial T1, coronal T2, and stern coronal image, we can see that there are well-defined geographic areas of altered signal intensity involving the anterior superior portion of the right femoral head, which is seen as hyper-intense with hyper-intense limb on T1 and T2 images. Now, we can also see T2 and stern hyper-intense signal edema involving bilateral femoral heads and femoral neck on the right side. The rest of the bones appear normal. The rest of the joint space and particular margins appear normal. These findings are suggestive of a vascular necrosis of the femoral heads. Right side, it is stage 2 of Fickertardlet classification, and on left side, it is stage 1, which appeared unremarkable on the X-ray. Now, on the second case, who is a 68-year-old male, presented with bilateral hip pain, we can see that there is mild bilateral hip joint space reduction. The articular margins are irregular, and there is subchondral patchy sclerosis. There is some degree of osteopenia also present. On the subsequent MR images, coronal T1, T2, and star images, we can see well-defined geographic areas of altered signal intensity involving the anterior superior portions of the bilateral femoral heads, which are seen as hyper-intense with hyper-intense limb on T1 and T2 embedded images. However, if we look closely, the overlying cortex is appearing intact, so no obvious crescent sign is seen. We can see T2 and star hyper-intense marrow edema involving bilateral femoral heads and neck. There is around 30-40% of the involvement of bilateral femoral capital articular surfaces. Mild hip joint diffusion is seen. So these findings are suggestive of stage 2 of picket alert classification, bilaterally. Now, in the third case, who is a 43-year-old female, presented with bilateral hip pain, we can see on the X-ray images that there is bilateral hip space reduction, and articular margins are irregular. And there are ill-defined mixed sclerotic and lytic areas involving bilateral femoral heads. Additional cortical collapse is seen on the superior aspect of the femoral head on the right side with a area of leucency, which is parallel to the articular surface, this leucency. This refers to the crescent sign. On the subsequent MR images, we can see on the axial T1 coronal and star T2 images, we can see geographically scattered areas of surface genus, heterogeneous T1, T2, and star signal intensity involving the anterior superior portions of the bilateral femoral heads. Now, there is around 50 to 60% involvement of the bilateral femoral capital articular surface, and there is flattening of the bilateral femoral heads, which is more pronounced on the left side. However, we can see that there is a sub-condrel crescent seen on the right side. Mild hip joint diffusion is seen. So these findings are suggestive of a vascular necrosis of bilateral femoral heads, which is classified into stage 3 of picotardium classification. Now, in the fourth case, who is a 55-year-old male presented with bilateral hip pain? On the X-ray images, we can see that there is bilaterally reduced joint space with remodeled femoral heads. And there are areas of sclerosis and lysis present on both the femoral heads. There is partial collapse of the femoral heads, which is more pronounced on the left side, with loss of sphericity. And on the subsequent MR images, we can see well-defined geographic areas of altered signal intensity, involving the bilateral femoral heads, bilateral acetaboli, and proximal shaft of bilateral femurs with collapse and flattening, and loss of contour of the left femoral head. We can see some osteophytes on the left side and on the right side as well. So these findings are classified into stage 4 of picotardium classification. In summary, I have correlated the X-ray patterns of AVN with MR images and 30 patients. 80% radiographic manifestations parallel the MRI findings with areas of sclerosis on plain sense, seen as areas of hyperintensity on MRI, and areas of radionucency seen as hyperintensity. Although it's stage 1, the patient has an abnormal MRI, but radiographs appear normal. It is reasonable to postulate that the MRI patterns detected in AVN reflect the different chronological stages of the disease, and it correlates with the X-ray patterns except in stage 1. MRI often demonstrates extensive changes while the conventional radiographs may not demonstrate that. This reflects the ability of MRI to detect the changes before a measurable X-ray change occurs. These are the references. Thank you.