Feline hip joint anatomy in magnetic resonance images

The aim of this study was to develop an anatomical model of the feline hip joint for low-field magnetic resonance imaging (LF-MRI) based on high-field magnetic resonance imaging (HF-MRI). The study was performed on six adult clinically healthy European shorthair cats, aged 1-3 years, with body weight of 2.8-4.4 kg. The animals were examined with the use of the Vet-MRI Grande Esaote LF (0.25 T) scanner and high-field Siemens Magnetom TRIO (3 T) MRI scanner. In the LF-MRI, most satisfactory results in T1-weighted images were obtained when TE was 26 ms in all three planes and when TR was 350-950 ms in the transverse plane, 950-1150 ms in the sagittal plane and 520-750 ms in the dorsal plane. In T2-weighted images, TE was 90 ms in the transverse and dorsal plane and 120 ms in the sagittal plane. The results were presented as images acquired with LF-MRI scanners in three planes. The slice thickness was 3 mm for each plane. In LF-MRI, muscles in the hip joint region and round ligament were well visualized. Unlike in LF-MRI, the cross section of the femoral nerve was identified in HF-MRI scans. In examinations of the feline hip joint, the main limitations of LF-MRI were a lack of reliable contrast between articular cartilage and synovial fluid as well as longer scan time. Despite the above, LF-MRI images were characterized by good contrast between bones and the surrounding soft tissues.