Detection of vascularity of femoral head using sub-millimeter resolution steady-state magnetic resonance angiography-initial experience.

Abstract

The purpose of this study was to use the steady-state (SS) magnetic resonance angiography (MRA) with a sub-millimeter resolution to detect the arteries supplying to the femoral head (FH). SS MRA scanning of hips was performed bilaterally in 15 healthy volunteers. A blood pool contrast agent was used. The scanning protocol included a 0.8-mm3 isotropic T1-fast field echo sequence with spectral fat suppression technique. Two highly qualified radiologists independently evaluated the medial circumflex femoral artery (MCFA), the lateral circumflex femoral artery (LCFA), and the three retinacular arteries including superior retinacular artery (SRA), inferior retinacular artery (IRA), and anterior retinacular artery (ARA). The intraosseous branches of the three retinacular arteries were also evaluated. An orthopaedic surgeon was consulted in case of disagreement. Observation by the two radiologists and support from the orthopaedic surgeon served as the end result. Agreement between the two observer radiologists was evaluated. Interobserver agreement between the two radiologists was found to be substantial to perfect. Of the 30 hips, the LCFA and MCFA were detected in all hips; the SRA and IRA were detected in most hips (100%, 90%), and the ARA was detected in 13 hips (43%). The intraosseous branches of SRA and IRA were detected in 30 and 22 hips (100%, 73%), respectively, while the intraosseous branches of ARA were detected in 11 hips (37%). The main arteries supplying the FH can be detected by the SS MRA, making it a novel method to detect the vascularity of FH.