PT - JOURNAL ARTICLE AU - Yu, Andy AU - Truong, Mylene AU - Wu, Carol AU - Betancourt Cuellar, Sonia AU - Ferreira Dalla Pria, Hanna AU - Pan, Tinsu TI - <strong>Evaluations of Misregistration and Motion-blur Corrections of 100 Whole Body 18F-FDG Patient Studies</strong> DP - 2023 Jun 01 TA - Journal of Nuclear Medicine PG - P1381--P1381 VI - 64 IP - supplement 1 4099 - http://jnm.snmjournals.org/content/64/supplement_1/P1381.short 4100 - http://jnm.snmjournals.org/content/64/supplement_1/P1381.full SO - J Nucl Med2023 Jun 01; 64 AB - P1381 Introduction: Respiratory motion induced misregistration between PET and CT and motion-blur in PET data can compromise accurate localization and quantification in whole body 18F-FDG PET/CT imaging, in particular in data-driven gated (DDG) PET, which gates PET data at or near the end-expiratory (EE) phase. The aim of this study is to investigate the effects of corrections on 100 consecutive FDG patient studies before and after misregistration and/or motion-blur corrections. Methods: A cohort of 100 consecutive FDG patient studies with misregistration at the diaphragm on four GE Discovery MI-25 cm PET/CT scanners was recruited in an institution approved IRB protocol. A low-dose cine CT of 5 sec duration per step and about ~14 cm coverage was acquired for average CT (ACT) and DDG CT for attenuation correction (AC) of static PET and DDG PET, respectively. The expiratory PET data of 30 to 80% over the breathing cycle was used for DDG PET, and the EE phase CT of the cine CT data was derived for DDG CT based on the lung CT number and body outlines. 1 The following were compared: 1) baseline PET/CT 2) PET/ACT for misregistration correction only, 3) DDG PET for motion-blur correction only (AC by baseline CT) and 4) DDG PET/CT (DDG PET and DDG CT) for both misregistration and motion-blur corrections. The FDG avid foci affected were assessed for changes in localization and changes in SUV. Results: Of the 100 cases, 74 studies had no FDG avid foci at the diaphragmatic interface, 4 had FDG avid foci near the diaphragm due to physiologic uptake, and 22 cases had pathologic foci near the diaphragm: 21 cases with liver metastases only and 1 case with both liver and lung metastases. In 18 of the 22 cases, these metastases were translocated to a different organ after misregistration and motion-blur corrections: 14 from lung to liver, 2 from the inferior vena cava to the liver, 1 from the liver to the lung, and 1 from the heart to the liver. Of these 18 cases, 7 cases failed to correct the translocation by PET/ACT for misregistration correction alone, and 17 cases failed to correct the translocation by DDG PET for motion-blur correction alone. In addition to correct localization, SUV measurements increased on average by 34.3% with PET/ACT for misregistration correction alone, 44.9% with DDG PET for motion-blur correction alone, and 69.6% with DDG PET/CT for both misregistration and motion-blur corrections. In 4 of the 22 cases, these metastases were not translocated to a different organ after misregistration or motion-blur correction. For these 4 cases, SUV measurements increased on average by 33.2% with PET/ACT, 38.9% with DDG PET, and 81% with DDG PET/CT.Conclusions: Misregistration between PET and CT and motion-blur in PET data can lead to misinterpretation of the site/organ of FDG avidity and artificially lower SUV measurements of metastases near the diaphragm. DDG PET/CT, which corrects for both misregistration and motion-blur, outperformed both PET/ACT, which only corrects for misregistration, and DDG PET, which only corrects for motion-blur. DDG PET/CT can be useful to localize the FDG avid foci and to accurately determine SUV measurements, which can impact the determination of treatment response and prognosis.