Rapid magnetic resonance imaging protocol for detecting femoral head avascular necrosis: A case series-it′s utility in the general population in developing countries

Abstract

Introduction: Osteonecrosis of the femoral head is an increasing cause of musculoskeletal disability, common among the younger population, between the third and fifth decade of life, affecting mainly men, thereby requiring prompt diagnosis and early intervention. Aims and Objectives: The aim was to formulate a limited magnetic resonance imaging (MRI) examination protocol for detection of avascular necrosis (AVN) in clinically suspected cases that can be performed rapidly and will be inexpensive. Materials and Methods: Forty-five patients suspected clinically and or on conventional radiography for AVN of the femoral head were referred for MRI hip. MRI hip was done on 1.5 T Siemens Avanto. Of 45, 36 were detected to have AVN (total 58 hips), whereas 9 did not have AVN on MRI. Initially, coronal T1-weighted image (T1WI) sequence was obtained as limited MRI protocol, followed by complete MRI examination. Results: Maximum patients belonged to age group 31-40 (30.5%). 32 (88.88%) patients were males and 4 (11.11%) were females. Bilateral AVN was detected in 44 (61.1%) and unilateral in 14 patients (38.8%). Pre collapsed stage (Stages I and II) was detected in 18 hips (31.03%), collapsed stage (Stages III and IV) was detected in 40 hips (68.9%). Peripheral low-intensity rim was seen on T1WI in all 58 cases of AVN. Double line sign on T2-weighted image was seen in 33/58 (56.8%). Conclusion: Our study concluded that coronal T1W sequence is an easy, rapid and cost-effective method of detecting unilateral or bilateral AVN.