 Avascular Necrosis of Hip MR Evaluate Introduction Avian is defined as cellular death of bone due to loss of blood supply because of any reason. The pathophysiology of vascular avian is not entirely understood but various factors causing avian has a common final effect of loss of blood supply to the affected bone or a part of it. Avian of the femoral head is more common than other sites presumably due to combination of pre-carious blood supply and high loading when standing. The risk factors include trauma alcohol, corticosteroid use, pancreatitis, sickle cell disease, infiltrator diseases, radiotherapy, renal transplantation and caesarean disease etc. The objectives of this evaluation is to analyze the role of a marine evaluation of avian of femoral head and to analyze the risk factors associated with development of avian of femoral head. Materials and methods used that is a prospective study of 50 patients who were diagnosed to have avian of femoral head clinically and referred for MRA of both hip joints to the Department of Radiology Andhra Medical College Mishak. Patients were scanned on 1.5 Tesla GE MRA machine using pelvic coil. The sequences selected were T1 coronal, T2 coronal, STIR coronal, T1 T2 axial, STIR axial, STIR sagittal, T2 sagittal. The patients giving informed consent to be part of the study or included in this study and the patients who are who there is clinical suspicion of avian and patients with unilateral or bilateral groin buttock thigh pain, deformity of limitation of range of hip movement and the traumatic cases clinically suspected to have avian. Patients who refused to consent, patients with non avian causes of femur thigh or knee pain and patients with contraindication to MRA imaging that is that of patients with ferromagnetic implants, cardiac pacemakers, claustrophobia etc. or excluded from the study. In our evaluation 13% of the people belong to female and 37% and 74% are male less than 6 patients are of less than 20 age group and 8 patients are between 21-30 age group, 14 patients between 31-40, 7 patients between 41-50, 6 patients between 51-60, 7 between 61-70 and 2 patients of more than 70. In our evaluation 16 cases are of unilateral and 34 cases are of bilateral avian. In this evaluation the most common location to be involved it is antero superior followed by antero medial and 14% 14 cases are complete and the most common risk factors studied in this evaluation is alcohol followed by trauma followed by corticosteroid and the last cases and last causes coming to ficart and islet stage 1 that is bone marrow edema. This is the corona still image showing bone marrow edema involving the femoral head and neck with minimal effusion. In ficart and islet stage 2 there is geographic area of altered signal intensity and double line sign. This is T1 and T2 coronal images showing geographic areas of altered signal intensity in the left femoral head and this is the T2 coronal weighted image showing double line sign that is hypo intense rim it is this hypo intense rim and inner hyper intense line on T2 weighted coronal. This is the coronal T2 image showing cortical collapse and flattening. This is MR image showing ficart and islet stage 4 showing secondary osteoarthritis changes. This is T1 coronal and T2 coronal image showing loss of articular cartilage and marginal osteophytes and joint effusion. In our study 1 case belong to stage 1 and 43 case 1 person 43 or of stage 2 23% or of stage 3 and 17% or of stage 4. Double line sign is seen in 69% of cases bone marrow edema is seen in 58% of cases joint effusion is seen in 49% of cases reduced joint space is seen in 29 and contour loss is seen in 45% of cases. There is another staging called Mitchell staging based on appearance of center region signal bounded by low signal rim on T1 and T2 weighted image with Mitchell staging A it follows the fat signal that is it appears the central region appears T1 hyper intense and T2 intermediate. This is Mitchell staging A showing T1 hyper intense and T2 intermediate signal intensity and it is bounded by hypo intense low signal low signal rim Mitchell staging B it follows sub acute blood signal it appears T1 hyper intense and T2 hyper intense Mitchell staging C follows fluid or edema signal it appears T1 hyper intense and T2 hyper intense Mitchell staging B follows fibrosis signal it appears hyper intense in both T1 and T2 images. In our study 17 patients or of stage A 31 or of B 12 patients or of C 24 patients or of D total study population we have included in the study or of 50 patients in those patients 37 or male and 13 or male and male with male to female ratio of 1 is to 0.35 most of the patients that is 44% of the patients were between 20 and 40 years bilateral avian is seen in 34 patients and unilateral in 16 patients the most common disc factor is alcohol consumption most common location is anterior superior surface of femoral head most common stage of avian was found to be stage 2 ficcata and arlett the most common MRA sign is in studied in this case was double line sign finally the analysis of the case on the case cases on the basis of Mitchell staging showed that out of 84 femoral heads stage B was the most common stage seen in 36.9 per 9 per conclusion MRA is indispensable for the detection and accurate staging of avian because it can clearly depict the size of the lesion and estimates of the stage of the disease can be made MRA facilitates better response to the treatment since avian can be diagnosed at an early stage and therapeutic measures are more successful the earlier they are in these are my differences