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Reproducibility of MRI Dixon-Based Attenuation Correction in Combined PET/MR with Applications for Lean Body Mass Estimation
- Source :
- Journal of Nuclear Medicine. 57:1096-1101
- Publication Year :
- 2016
- Publisher :
- Society of Nuclear Medicine, 2016.
-
Abstract
- The aim of this study was to assess the reproducibility of standard, Dixon-based attenuation correction (MR-AC) in PET/MR imaging. A further aim was to estimate a patient-specific lean body mass (LBM) from these MR-AC data. Methods: Ten subjects were positioned in a fully integrated PET/MR system, and 3 consecutive multibed acquisitions of the standard MR-AC image data were acquired. For each subject and MR-AC map, the following compartmental volumes were calculated: total body, soft tissue (ST), fat, lung, and intermediate tissue (IT). Intrasubject differences in the total body and subcompartmental volumes (ST, fat, lung, and IT) were assessed by means of coefficients of variation (CVs) calculated across the 3 consecutive measurements and, again, across these measurements but excluding those affected by major artifacts. All subjects underwent a body composition measurement using air displacement plethysmography (ADP) that was used to calculate a reference LBMADP. A second LBM estimate was derived from available MR-AC data using a formula incorporating the respective tissue volumes and densities as well as the subject-specific body weights. A third LBM estimate was obtained from a sex-specific formula (LBMFormula). Pearson correlation was calculated for LBMADP, LBMMR-AC, and LBMFormula. Further, linear regression analysis was performed on LBMMR-AC and LBMADP.Results: The mean CV for all 30 scans was 2.1 ± 1.9% (TB). When missing tissue artifacts were excluded, the CV was reduced to 0.3 ± 0.2%. The mean CVs for the subcompartments before and after exclusion of artifacts were 0.9 ± 1.1% and 0.7 ± 0.7% for the ST, 2.9 ± 4.1% and 1.3 ± 1.0% for fat, and 3.6 ± 3.9% and 1.3 ± 0.7% for the IT, respectively. Correlation was highest for LBMMR-AC and LBMADP (r = 0.99). Linear regression of data excluding artifacts resulted in a scaling factor of 1.06 for LBMMR-AC. Conclusion: LBMMR-AC is shown to correlate well with standard LBM measurements and thus offers routine LBM-based SUV quantification in PET/MR. However, MR-AC images must be controlled for systematic artifacts, including missing tissue and tissue swaps. Efforts to minimize these artifacts could help improve the reproducibility of MR-AC.
- Subjects :
- Adult
Male
Multimodal Imaging
030218 nuclear medicine & medical imaging
03 medical and health sciences
symbols.namesake
0302 clinical medicine
Fluorodeoxyglucose F18
Linear regression
Image Processing, Computer-Assisted
Humans
Medicine
Whole Body Imaging
Radiology, Nuclear Medicine and imaging
Plethysmography, Whole Body
Sex Characteristics
Reproducibility
business.industry
Reproducibility of Results
Soft tissue
Total body
Magnetic Resonance Imaging
Mr imaging
Pearson product-moment correlation coefficient
Positron-Emission Tomography
030220 oncology & carcinogenesis
Body Composition
symbols
Lean body mass
Female
Artifacts
business
Nuclear medicine
Correction for attenuation
Algorithms
Subjects
Details
- ISSN :
- 2159662X and 01615505
- Volume :
- 57
- Database :
- OpenAIRE
- Journal :
- Journal of Nuclear Medicine
- Accession number :
- edsair.doi.dedup.....0bece89cbf4cf154cdf62caa95c98e46