Utility of magnetic resonance spectroscopy and diffusion-weighted imaging for detecting changes in the femoral head in divers with hip pain at risk for dysbaric osteonecrosis

Tsung-Tai Lin; Cheng-Chuan Hu; Yi-Chih Hsu; Chih-Chien Wang; Shih-Wei Chiang; Chao-Ying Wang; Wei-Chou Chang; Guo-Shu Huang

doi:10.21037/qims-21-148

Utility of magnetic resonance spectroscopy and diffusion-weighted imaging for detecting changes in the femoral head in divers with hip pain at risk for dysbaric osteonecrosis

Quant Imaging Med Surg. 2022 Jan;12(1):43-52. doi: 10.21037/qims-21-148.

Authors

Tsung-Tai Lin¹, Cheng-Chuan Hu¹, Yi-Chih Hsu¹, Chih-Chien Wang², Shih-Wei Chiang¹, Chao-Ying Wang³, Wei-Chou Chang¹, Guo-Shu Huang^{1

4}

Affiliations

¹ Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
² Department of Orthopedic Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
³ Department and Graduate Institute of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan.
⁴ Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.

Abstract

Background: Ischemia before the development of dysbaric osteonecrosis (DON) in femoral heads has never been investigated. We assessed whether quantitative magnetic resonance spectroscopy (MRS) and diffusion weighted imaging (DWI) could detect dysbaric changes in divers with hip pain.

Methods: This IRB-approved exploratory study recruited 17 divers [9 with hip pain (Group 1); 8 asymptomatic (Group 2)] with normal findings on radiographs and conventional magnetic resonance imaging scans were age-, gender- and body-mass-index matched to 17 non-divers as controls (Group 1C, 2C). Apparent diffusion coefficients (ADCs) and MRS spectra were obtained from regions/voxels of interest on the femoral heads of all subjects. LCModel was used to determine water content, lipid composition, and the unsaturation index in bone marrow. Mann-Whitney non-parametric test was used to compare results of quantitative MRS and ADCs of ipsilateral femoral heads between divers and controls.

Results: MRS of the ipsilateral femoral heads revealed higher water (peak: 4.7 ppm) content, lower total lipid fraction (TLF), and higher unsaturation index (UI) of lipids in Group 1 than in Group 2 (water: P=0.040; UI: P=0.022) and Group 1C (water: P=0.027; TLF: P=0.039; UI: P=0.009). In contrast, femoral head ADCs were comparable between divers and controls. Five out of nine symptomatic divers were contacted for follow-up MRS and DWI studies, and the mean difference in water content in the femoral heads of patients with osteonecrosis was also higher than that in patients with symptom relief (osteonecrosis: 0.077±0.130 vs. symptom relief: 0.003±0.010).

Conclusions: Dysbaric change in the femoral heads of divers with hip pain can be detected using quantitative MRS, which reveals increases in water content and UI of lipids, and a decrease in TLF.

Keywords: Dysbaric change; diffusion-weighted magnetic resonance imaging (diffusion-weighted MRI); diving; femoral head; magnetic resonance spectroscopy (MRS).