Martijn F Boomsma1, Inge Slouwerhof2, Jorn A van Dalen2, Mireille A Edens3, Dirk Mueller4, Julien Milles5, Mario Maas6. 1. Department of Radiology, Isala Hospital, Zwolle, The Netherlands. m.f.boomsma@isala.nl. 2. Department of Radiology, Isala Hospital, Zwolle, The Netherlands. 3. Department of Innovation and Science, Isala Hospital, Zwolle, The Netherlands. 4. Philips Healthcare systems, Hamburg, Germany. 5. Philips Healthcare Benelux, Eindhoven, The Netherlands. 6. Department of Radiology, AMC, Amsterdam, The Netherlands.
Abstract
PURPOSE: The purpose of this research is to study the use of an internal reference standard for fat- and muscle as a replacement for an external reference standard with a phantom. By using a phantomless internal reference standard, Hounsfield unit (HU) measurements of various tissues can potentially be assessed in patients with a CT scan of the pelvis without an added phantom at time of CT acquisition. This paves the way for development of a tool for quantification of the change in tissue density in one patient over time and between patients. This could make every CT scan made without contrast available for research purposes. MATERIALS AND METHODS: Fifty patients with unilateral metal-on-metal total hip replacements, scanned together with a calibration reference phantom used in bone mineral density measurements, were included in this study. On computed tomography scans of the pelvis without the use of intravenous iodine contrast, reference values for fat and muscle were measured in the phantom as well as within the patient's body. The conformity between the references was examined with the intra-class correlation coefficient. RESULTS: The mean HU (± SD) of reference values for fat for the internal- and phantom references were -91.5 (±7.0) and -90.9 (±7.8), respectively. For muscle, the mean HU (± SD) for the internal- and phantom references were 59.2 (±6.2) and 60.0 (±7.2), respectively. The intra-class correlation coefficients for fat and muscle were 0.90 and 0.84 respectively and show excellent agreement between the phantom and internal references. CONCLUSION: Internal references can be used with similar accuracy as references from an external phantom. There is no need to use an external phantom to asses CT density measurements of body tissue.
PURPOSE: The purpose of this research is to study the use of an internal reference standard for fat- and muscle as a replacement for an external reference standard with a phantom. By using a phantomless internal reference standard, Hounsfield unit (HU) measurements of various tissues can potentially be assessed in patients with a CT scan of the pelvis without an added phantom at time of CT acquisition. This paves the way for development of a tool for quantification of the change in tissue density in one patient over time and between patients. This could make every CT scan made without contrast available for research purposes. MATERIALS AND METHODS: Fifty patients with unilateral metal-on-metal total hip replacements, scanned together with a calibration reference phantom used in bone mineral density measurements, were included in this study. On computed tomography scans of the pelvis without the use of intravenous iodine contrast, reference values for fat and muscle were measured in the phantom as well as within the patient's body. The conformity between the references was examined with the intra-class correlation coefficient. RESULTS: The mean HU (± SD) of reference values for fat for the internal- and phantom references were -91.5 (±7.0) and -90.9 (±7.8), respectively. For muscle, the mean HU (± SD) for the internal- and phantom references were 59.2 (±6.2) and 60.0 (±7.2), respectively. The intra-class correlation coefficients for fat and muscle were 0.90 and 0.84 respectively and show excellent agreement between the phantom and internal references. CONCLUSION: Internal references can be used with similar accuracy as references from an external phantom. There is no need to use an external phantom to asses CT density measurements of body tissue.
Entities:
Keywords:
CT; Hip; Metal-on-metal; Phantom less bone mineral density; Total hip arthroplasty
Authors: Dirk K Mueller; Alex Kutscherenko; Hans Bartel; Alain Vlassenbroek; Petr Ourednicek; Joachim Erckenbrecht Journal: Eur J Radiol Date: 2010-03-12 Impact factor: 3.528
Authors: James A Browne; C Dustin Bechtold; Daniel J Berry; Arlen D Hanssen; David G Lewallen Journal: Clin Orthop Relat Res Date: 2010-09 Impact factor: 4.176
Authors: David Fabi; Brett Levine; Wayne Paprosky; Craig Della Valle; Scott Sporer; Gregg Klein; Harlan Levine; Mark Hartzband Journal: Orthopedics Date: 2012-07-01 Impact factor: 1.390
Authors: Wierd P Zijlstra; Hugo C van der Veen; Inge van den Akker-Scheek; Mark J M Zee; Sjoerd K Bulstra; Jos J A M van Raay Journal: Hip Int Date: 2013-09-24 Impact factor: 2.135
Authors: Ainsley C J Smith; Justin J Tse; Tadiwa H Waungana; Kirsten N Bott; Michael T Kuczynski; Andrew S Michalski; Steven K Boyd; Sarah L Manske Journal: PLoS One Date: 2022-10-17 Impact factor: 3.752