E-Poster Presentation ESA-SRB-ANZBMS 2021

Development of a novel method to measure bone marrow fat fraction in older women using high-resolution peripheral quantitative computed tomography (#740)

Alison Flehr 1 , Julius Källgård 2 , Jennifer Alvén 3 4 , Kerstin Lagerstrand 5 6 , Evin Papalini 2 5 , Michael Wheeler 1 , Liesbeth Vandenput 1 2 , Fredrik Kahl 7 , Kristian F Axelsson 2 8 , Daniel Sundh 2 , Raghunath Shirish Mysore 2 , Mattias Lorentzon 1 2 9
  1. Bone Health and Fractures Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
  2. Sahlgrenska Osteoporosis Centre, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
  3. Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
  4. Computer Vision and Medical Image Analysis, Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden
  5. Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
  6. Department of Radiation Physics, Institution of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
  7. Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden
  8. Primary Care, Region Västra Götaland, Skövde, Sweden
  9. Geriatric Medicine, Sahlgrenska University Hospital, Region Västra Götaland, Mölndal, Sweden

Marrow adipose tissue (MAT) has been implicated in a number of conditions associated with bone deterioration and osteoporosis. Several studies have found an inverse relationship between MAT and bone mineral density (BMD), and higher levels of MAT in those with prevalent fracture. Magnetic resonance imaging (MRI) is the gold standard for measuring MAT but its use is limited by high costs and low availability. We hypothesized that MAT could also be accurately quantified using high-resolution peripheral quantitative computed tomography (HR-pQCT).

In the present study, a novel method to quantify the tibia bone marrow fat fraction, defined by MRI, using HR-pQCT was developed. In total, 38 postmenopausal women (mean [standard deviation] age 75.9 [3.1] years) were included and measured at the same site at the distal (n=38) and ultradistal (n=18) tibia using both MRI and HR-pQCT. To adjust for partial volume effects, the HR-pQCT images underwent 0 to 10 layers of voxel peeling to remove voxels adjacent to the bone. Linear regression equations were then tested for different degrees of voxel peeling, using the MRI-derived fat fractions as the dependent variable and the HR-pQCT-derived radiodensity as the independent variables.

The most optimal HR-pQCT-derived model, which applied a minimum of 4 layers of peeled voxel and with more than 1% remaining marrow volume, was able to explain 76% of the variation in the ultradistal tibia bone marrow fat fraction, measured with MRI (p<0.001).

The novel HR-pQCT method, developed to estimate MAT, was able to explain a substantial part of the variation in the bone marrow fat fraction and can be used in future studies investigating the role of MAT in osteoporosis and fracture risk prediction.