Felix C Müller1, Kasper K Gosvig2, Østergaard Mikkel3, Roed Bjarne4, Anders Rodell4, Børgesen Henrik2, Bernhard Krauss5, Jesper S Gade6, Mikael Boesen7. 1. Department of Radiology, Herlev and Gentofte Hospital, Borgmester Ib Juuls Vej 17, 2730, Herlev, Denmark; Siemens Healthineers, Borupvang 9, 2750, Ballerup, Denmark. Electronic address: Christoph.felix.mueller@regionh.dk. 2. Department of Radiology, Herlev and Gentofte Hospital, Borgmester Ib Juuls Vej 17, 2730, Herlev, Denmark. 3. Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Valdemar Hansens Vej 1-23, Glostrup, Denmark; Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200, København, Copenhagen, Denmark. 4. Siemens Healthineers, Borupvang 9, 2750, Ballerup, Denmark. 5. Siemens Healthineers, Siemensstraße 1, 91301, Forchheim, Germany. 6. Department of Radiology, Sygehus Lillebælt, Beriderbakken 4, 7100, Vejle, Denmark. 7. Department of Radiology, Bispebjerg and Frederiksberg Hospital, Bispebjerg Bakke 23, 2400, København, Denmark.
Abstract
PURPOSE: Purpose of this study was to investigate Dual-energy CT (DECT) derived virtual non-calcium (VNCa) values for absolute quantification of the bone marrow composition in the wrist. MATERIALS AND METHODS: We prospectively included consecutive adult participants and examined their wrists with DECT. Ranges of VNCa and calcium values were measured in the carpal bones, radius and ulna using a semi-automatic method. Bones with bone marrow edema, assessed by two blinded radiologists, were excluded. After determining optimum parameters for the three-material decomposition, the influence of calcium values, age and sex on VNCa values was assessed using multiple linear regression. RESULTS: 41 participants (Median age 53 years, range 20 years - 88 years, 51 % men) were enrolled and 399 bones assessed. At participant level mean VNCa values were -143 HU (SD 14 HU) using the current parameters for three-material decomposition and -104HU (SD 11 HU) with optimized parameters. There was a strong and significant influence of calcium values on VNCa values with the current parameters (p < 0.001, -0.137 HU[VNCa] / HU[Calcium]). With optimized parameters the calcium values and sex were not statistically significant predictors of VNCa values. Age was a significant, but clinically negligible, predictor (p = 0.03, -0.225 HU / year). CONCLUSIONS: After optimizing three-material decomposition parameters, calcium values, age and sex do not substantially influence virtual non-calcium values, and DECT may therefore be used for absolute quantification of the bone marrow composition - alleviating the need for reference bones or groups.
PURPOSE: Purpose of this study was to investigate Dual-energy CT (DECT) derived virtual non-calcium (VNCa) values for absolute quantification of the bone marrow composition in the wrist. MATERIALS AND METHODS: We prospectively included consecutive adult participants and examined their wrists with DECT. Ranges of VNCa and calcium values were measured in the carpal bones, radius and ulna using a semi-automatic method. Bones with bone marrow edema, assessed by two blinded radiologists, were excluded. After determining optimum parameters for the three-material decomposition, the influence of calcium values, age and sex on VNCa values was assessed using multiple linear regression. RESULTS: 41 participants (Median age 53 years, range 20 years - 88 years, 51 % men) were enrolled and 399 bones assessed. At participant level mean VNCa values were -143 HU (SD 14 HU) using the current parameters for three-material decomposition and -104HU (SD 11 HU) with optimized parameters. There was a strong and significant influence of calcium values on VNCa values with the current parameters (p < 0.001, -0.137 HU[VNCa] / HU[Calcium]). With optimized parameters the calcium values and sex were not statistically significant predictors of VNCa values. Age was a significant, but clinically negligible, predictor (p = 0.03, -0.225 HU / year). CONCLUSIONS: After optimizing three-material decomposition parameters, calcium values, age and sex do not substantially influence virtual non-calcium values, and DECT may therefore be used for absolute quantification of the bone marrow composition - alleviating the need for reference bones or groups.