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Osteochondritis Dissecans of the Knee at 7-T Trabecular Bone MRI

Published Online:https://doi.org/10.1148/radiol.240048

A 15-year-old male patient had recurrent right knee pain for over 2 years after experiencing a fall during a basketball game. Radiographs were normal. Dual-energy CT and 3-T MRI of the knee revealed subchondral bone marrow edema at the trochlear articular surface of the lateral femoral condyle and no abnormalities in the tendons, ligaments, or menisci (Fig 1). High-spatial-resolution gradient-recalled-echo trabecular bone MRI at 7 T (1) indicated discontinuity in the subchondral bone plate and intact overlying cartilage (Fig 2), consistent with stable osteochondritis dissecans (2). The adolescent was recommended to abstain from physical activities and wear a knee brace for a minimum of 6 weeks. After 3 months, the subchondral progeny fragment exhibited near-complete healing with surrounding parent bone (Fig 2), and the knee pain resolved. The findings from this case underscore the ability of 7-T MRI to offer information that is unattainable through conventional imaging.

Initial imaging in a 15-year-old male patient with chronic right knee pain. (A) Anteroposterior radiograph shows normal findings. (B) Axial and (C) sagittal CT images with a voxel size of 0.4 × 0.4 × 0.4 mm show no apparent fracture. (D) Axial postprocessed virtual noncalcium image, (E) axial proton-weighted turbo spin-echo image at 3 T with a voxel size of 0.52 × 0.52 × 3.5 mm, and (F) sagittal T1-weighted turbo spin-echo image at 3 T with a voxel size of 0.45 × 0.45 × 3 mm demonstrate bone marrow edema of the lateral femoral condyle (arrow). Color scale in D, −150 to 100 HU.

Figure 1: Initial imaging in a 15-year-old male patient with chronic right knee pain. (A) Anteroposterior radiograph shows normal findings. (B) Axial and (C) sagittal CT images with a voxel size of 0.4 × 0.4 × 0.4 mm show no apparent fracture. (D) Axial postprocessed virtual noncalcium image, (E) axial proton-weighted turbo spin-echo image at 3 T with a voxel size of 0.52 × 0.52 × 3.5 mm, and (F) sagittal T1-weighted turbo spin-echo image at 3 T with a voxel size of 0.45 × 0.45 × 3 mm demonstrate bone marrow edema of the lateral femoral condyle (arrow). Color scale in D, −150 to 100 HU.

High-spatial-resolution 7-T MRI scans (A, C) before and (B, D) after treatment for osteochondritis dissecans of the knee. (A) The fracture line (arrow) is clearly visualized on the axial gradient-recalled-echo trabecular bone image with the following scan parameters: repetition time msec/echo time msec, 8.0/3.64; no fat suppression; flip angle, 15°; and voxel size, 0.1 × 0.1 × 0.8 mm. (C) Axial proton-weighted turbo spin-echo image with a voxel size of 0.1 × 0.1 × 2 mm demonstrates edema in the subchondral bone area (arrow). Corresponding (B) trabecular bone and (D) proton-weighted turbo spin-echo images at 3-month follow-up show near-complete fracture healing.

Figure 2: High-spatial-resolution 7-T MRI scans (A, C) before and (B, D) after treatment for osteochondritis dissecans of the knee. (A) The fracture line (arrow) is clearly visualized on the axial gradient-recalled-echo trabecular bone image with the following scan parameters: repetition time msec/echo time msec, 8.0/3.64; no fat suppression; flip angle, 15°; and voxel size, 0.1 × 0.1 × 0.8 mm. (C) Axial proton-weighted turbo spin-echo image with a voxel size of 0.1 × 0.1 × 2 mm demonstrates edema in the subchondral bone area (arrow). Corresponding (B) trabecular bone and (D) proton-weighted turbo spin-echo images at 3-month follow-up show near-complete fracture healing.

Disclosures of conflicts of interest: Z.Z. No relevant relationships. W.C. No relevant relationships.

Acknowledgments

We thank Wei Chen, PhD (MR Research Collaboration Teams, Siemens Healthineers), for providing technical support and Lin Guo, MD, PhD (Department of Sports Medicine, Southwest Hospital, Army Medical University), for constructive comments on the manuscript. These individuals were not compensated for these contributions.

References

  • 1. Guenoun D, Pithioux M, Souplet JC, et al. Assessment of proximal femur microarchitecture using ultra-high field MRI at 7 tesla. Diagn Interv Imaging 2020;101(1):45–53.
  • 2. Gorbachova T, Amber I, Beckmann NM, et al. Nomenclature of subchondral nonneoplastic bone lesions. AJR Am J Roentgenol 2019;213(5):963–982.

Article History

Received: Jan 9 2024
Revision requested: Feb 5 2024
Revision received: Feb 15 2024
Accepted: Mar 5 2024
Published online: June 11 2024