Evaluation of Osseous Morphology of the Hip Using Zero Echo Time Magnetic Resonance Imaging

Abstract

Background: Femoroacetabular impingement syndrome (FAIS) is a common disorder of the hip resulting in groin pain and ultimately osteoarthritis. Radiologic assessment of FAI morphologies, which may present with overlapping radiologic features of hip dysplasia, often requires the use of computed tomography (CT) for evaluation of osseous abnormality, owing to the difficulty of direct visualization of cortical and subchondral bone with conventional magnetic resonance imaging (MRI). The use of a zero echo time (ZTE) MRI pulse sequence may obviate the need for CT by rendering bone directly from MRI. Purpose/Hypothesis: The purpose was to explore the application of ZTE MRI to the assessment of osseous FAI and dysplasia morphologies of the hip. It was hypothesized that angular measurements from ZTE images would show significant agreement with measurements obtained from CT images. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Thirty-eight hips from 23 patients were imaged with ZTE MRI and CT. Clinically relevant angular measurements of hip morphology were made in both modalities and compared to assess agreement. Measurements included coronal and sagittal center-edge angles, femoral neck-shaft angle, acetabular version (at 1-, 2-, and 3-o’clock positions), Tönnis angle, alpha angle, and modified-beta angle. Interrater agreement was assessed for a subset of 10 hips by 2 raters. Intermodal agreement was assessed on the complete cohort and a single rater. Results: Interrater agreement was demonstrated in both CT and ZTE, with intraclass correlation coefficient values ranging from 0.636 to 0.990 for ZTE and 0.747 to 0.983 for CT, indicating “good” to “excellent” agreement. Intermodal agreement was also shown to be significant, with intraclass correlation coefficients ranging from 0.618 to 0.904. Conclusion: Significant agreement of angular measurements for hip morphology exists between ZTE MRI and CT imaging. ZTE MRI may be an effective method to quantitatively evaluate osseous hip morphology.

CT-like images based on T1 spoiled gradient-echo and ultra-short echo time MRI sequences for the assessment of vertebral fractures and degenerative bone changes of the spine

“…for assessing the cartilage endplate [ 33 ] and to differentiate ligaments and calcified structures. ZTE pulse sequences, on the other hand, generate real PD-weighted tissue contrast and have been successfully applied to the shoulder, hip, skull, and cervical spine [ 20 , 34 – 36 ]. How they perform in the thoracolumbar spine in comparison to T1SGRE should be evaluated in future studies.…”

MRI-based Synthetic CT in the Detection of Structural Lesions in Patients with Suspected Sacroiliitis: Comparison with MRI

“…Gersing et al (22) found that MRI-derived radiograph-like images were feasible for bone tumor evaluation and were comparable to radiographs. Argentieri et al (23) and Breighner et al (24) presented MRI-based CT-like images based on zero echo time sequences and reported good agreement with CT of the spine and hips. However, this qualitative technique lacks specificity for cortical bone and requires specific hardware.…”

Evaluation of Osseous Incorporation After Osteochondral Allograft Transplantation: Correlation of Computed Tomography Parameters With Patient-Reported Outcomes

“…Furthermore, newly developed zero echo time MRI pulse sequences may be promising for the evaluation of bone morphology. 3…”