Siavash Mehdizadeh Seraj1, William Y Raynor1, Mona-Elisabeth Revheim1,2,3, Abdullah Al-Zaghal1, Mahdi Zirakchian Zadeh1, Leila S Arani1, Chaitanya Rojulpote1, Thomas J Werner1, Oke Gerke4,5, Poul F Høilund-Carlsen4,5, Joshua F Baker6,7,8, Abass Alavi9, Stephen J Hunt1. 1. Department of Radiology, Hospital of University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA. 2. Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway. 3. Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway. 4. Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark. 5. Department of Clinical Research, University of Southern Denmark, Odense, Denmark. 6. Division of Rheumatology, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA. 7. Division of Rheumatology, University of Pennsylvania, Philadelphia, PA, USA. 8. Department of Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, PA, USA. 9. Department of Radiology, Hospital of University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA. abass.alavi@uphs.upenn.edu.
Abstract
OBJECTIVE: We aimed to determine whether NaF-PET/CT or FDG-PET/CT can detect abdominal aortic molecular calcification and inflammation in patients with rheumatoid arthritis (RA). METHODS: In this study, 18 RA patients (4 women, 14 men; mean age 56.0 ± 11.7) and 18 healthy controls (4 women, 14 men; mean age 55.8 ± 11.9) were included. The controls were matched to patients by sex and age (± 4 years). All subjects of this study underwent NaF-PET/CT scanning 90 min following the administration of NaF. FDG-PET/CT imaging was performed 180 min following intravenous FDG injection. Using OsiriX software, the global mean standardized uptake value (global SUVmean) in abdominal aorta was calculated for both FDG and NaF. The NaF SUVmean and FDG SUVmean were divided by the blood pool activity providing target-to-background ratios (TBR) namely, NaF-TBRmean and FDG-TBRmean. The CT calcium volume score was obtained using a growing region algorithm based on Hounsfield units. RESULTS: The average NaF-TBRmean score among RA patients was significantly greater than that of healthy controls (median 1.61; IQR 1.49-1.88 and median 1.40; IQR 1.23-1.52, P = 0.002). The average CT calcium volume score among RA patients was also significantly greater than that of healthy controls (median 1.96 cm3; IQR 0.57-5.48 and median 0.004 cm3; IQR 0.04-0.05, P < 0.001). There was no significant difference between the average FDG-TBRmean scores in the RA patients when compared to healthy controls (median 1.29; IQR 1.13-1.52 and median 1.29; IQR 1.13-1.52, respectively, P = 0.98). CONCLUSION: Quantitative assessment with NaF-PET/CT identifies increased molecular calcification in the wall of the abdominal aorta among patients with RA as compared with healthy controls, while quantitative assessment with FDG-PET/CT did not identify a difference in aortic vessel wall FDG uptake between the RA and healthy control groups.
OBJECTIVE: We aimed to determine whether NaF-PET/CT or FDG-PET/CT can detect abdominal aortic molecular calcification and inflammation in patients with rheumatoid arthritis (RA). METHODS: In this study, 18 RApatients (4 women, 14 men; mean age 56.0 ± 11.7) and 18 healthy controls (4 women, 14 men; mean age 55.8 ± 11.9) were included. The controls were matched to patients by sex and age (± 4 years). All subjects of this study underwent NaF-PET/CT scanning 90 min following the administration of NaF. FDG-PET/CT imaging was performed 180 min following intravenous FDG injection. Using OsiriX software, the global mean standardized uptake value (global SUVmean) in abdominal aorta was calculated for both FDG and NaF. The NaF SUVmean and FDG SUVmean were divided by the blood pool activity providing target-to-background ratios (TBR) namely, NaF-TBRmean and FDG-TBRmean. The CT calcium volume score was obtained using a growing region algorithm based on Hounsfield units. RESULTS: The average NaF-TBRmean score among RApatients was significantly greater than that of healthy controls (median 1.61; IQR 1.49-1.88 and median 1.40; IQR 1.23-1.52, P = 0.002). The average CT calcium volume score among RApatients was also significantly greater than that of healthy controls (median 1.96 cm3; IQR 0.57-5.48 and median 0.004 cm3; IQR 0.04-0.05, P < 0.001). There was no significant difference between the average FDG-TBRmean scores in the RApatients when compared to healthy controls (median 1.29; IQR 1.13-1.52 and median 1.29; IQR 1.13-1.52, respectively, P = 0.98). CONCLUSION: Quantitative assessment with NaF-PET/CT identifies increased molecular calcification in the wall of the abdominal aorta among patients with RA as compared with healthy controls, while quantitative assessment with FDG-PET/CT did not identify a difference in aortic vessel wall FDG uptake between the RA and healthy control groups.