Comparing Diagnostic Performance of Short and Long [<sup>18</sup>F]FDG-PET Acquisition Times in Giant Cell Arteritis
Pieter H. Nienhuis,
Marieke van Nieuwland,
Gijs D. van Praagh,
Karolina Markusiewicz,
Edgar M. Colin,
Kornelis S. M. van der Geest,
Nils Wagenaar,
Elisabeth Brouwer,
Celina Alves,
Riemer H. J. A. Slart
Affiliations
Pieter H. Nienhuis
University of Groningen, University Medical Center Groningen, Medical Imaging Center, Department of Nuclear Medicine and Molecular Imaging, 9713 GZ Groningen, The Netherlands
Marieke van Nieuwland
Hospital Group Twente, Department of Rheumatology and Clinical Immunology, 7600 SZ Almelo, The Netherlands
Gijs D. van Praagh
University of Groningen, University Medical Center Groningen, Medical Imaging Center, Department of Nuclear Medicine and Molecular Imaging, 9713 GZ Groningen, The Netherlands
Karolina Markusiewicz
Medical University of Warsaw, 02-091 Warsaw, Poland
Edgar M. Colin
Hospital Group Twente, Department of Rheumatology and Clinical Immunology, 7600 SZ Almelo, The Netherlands
Kornelis S. M. van der Geest
University of Groningen, University Medical Center Groningen, Department of Rheumatology and Clinical Immunology, 9713 GZ Groningen, The Netherlands
Nils Wagenaar
Hospital Group Twente, Department of Nuclear Medicine, 7555 DL Hengelo, The Netherlands
Elisabeth Brouwer
University of Groningen, University Medical Center Groningen, Department of Rheumatology and Clinical Immunology, 9713 GZ Groningen, The Netherlands
Celina Alves
Hospital Group Twente, Department of Rheumatology and Clinical Immunology, 7600 SZ Almelo, The Netherlands
Riemer H. J. A. Slart
University of Groningen, University Medical Center Groningen, Medical Imaging Center, Department of Nuclear Medicine and Molecular Imaging, 9713 GZ Groningen, The Netherlands
(1) Background: In giant cell arteritis (GCA), the assessment of cranial arteries using [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography (PET) combined with low-dose computed tomography (CT) may be challenging due to low image quality. This study aimed to investigate the effect of prolonged acquisition time on the diagnostic performance of [18F]FDG PET/CT in GCA. (2) Methods: Patients with suspected GCA underwent [18F]FDG-PET imaging with a short acquisition time (SAT) and long acquisition time (LAT). Two nuclear medicine physicians (NMPs) reported the presence or absence of GCA according to the overall image impression (gestalt) and total vascular score (TVS) of the cranial arteries. Inter-observer agreement and intra-observer agreement were assessed. (3) Results: In total, 38 patients were included, of whom 20 were diagnosed with GCA and 18 were without it. Sensitivity and specificity for GCA on SAT scans were 80% and 72%, respectively, for the first NMP, and 55% and 89% for the second NMP. On the LAT scans, these values were 65% and 83%, and 75% and 83%, respectively. When using the TVS, LAT scans showed especially increased specificity (94% for both NMPs). Observer agreement was higher on the LAT scans compared with that on the SAT scan. (4) Conclusions: LAT combined with the use of the TVS may decrease the number of false-positive assessments of [18F]FDG PET/CT. Additionally, LAT and TVS may increase both inter and intra-observer agreement.
