ABSTRACT
Purpose: To investigate the physiological uptake of hybrid fluorine-18-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) before and after an uncomplicated endovascular aneurysm sealing (EVAS) procedure as a possible tool to diagnose EVAS graft infection and differentiate from postimplantation syndrome. Materials and Methods: Eight consecutive male patients (median age 78 years) scheduled for elective EVAS were included in the prospective study (ClinicalTrials.gov identifier NCT02349100). FDG-PET/CT scans were performed in all patients before the procedure and 6 weeks after EVAS. The abdominal aorta was analyzed in 4 regions: suprarenal, infrarenal neck, aneurysm sac, and iliac. The following parameters were obtained for each region: standard uptake value (SUV), tissue to background ratio (TBR), and visual examination of FDG uptake to ascertain its distribution. Demographic data were obtained from medical files and scored based on reporting standards. Results: Visual examination showed no difference between pre- and postprocedure FDG uptake, which was homogenous. In the suprarenal region no significant pre- and postprocedure differences were observed for the SUV and TBR parameters. The infrarenal neck region showed a significant decrease in the SUV and no significant decrease in the TBR. The aneurysm sac and iliac regions both showed a significant decrease in SUV and TBR between the pre- and postprocedure scans. Conclusion: Physiological FDG uptake after EVAS was stable or decreased with regard to the preprocedure measurements. Future research is needed to assess the applicability and cutoff values of FDG-PET/CT scanning to detect endograft infection after EVAS.
Subject(s)
Aorta, Abdominal/surgery , Aortic Aneurysm, Abdominal/surgery , Blood Vessel Prosthesis Implantation/instrumentation , Blood Vessel Prosthesis , Endovascular Procedures/instrumentation , Fluorodeoxyglucose F18/administration & dosage , Positron Emission Tomography Computed Tomography , Postoperative Complications/diagnostic imaging , Prosthesis-Related Infections/diagnostic imaging , Radiopharmaceuticals/administration & dosage , Aged , Aged, 80 and over , Aorta, Abdominal/diagnostic imaging , Aorta, Abdominal/physiopathology , Aortic Aneurysm, Abdominal/diagnostic imaging , Aortic Aneurysm, Abdominal/physiopathology , Blood Vessel Prosthesis/adverse effects , Blood Vessel Prosthesis Implantation/adverse effects , Diagnosis, Differential , Endovascular Procedures/adverse effects , Humans , Male , Predictive Value of Tests , Prospective Studies , Prosthesis Design , Prosthesis-Related Infections/microbiology , Reproducibility of Results , Treatment OutcomeABSTRACT
Following the instillation of a drug into the eye, drainage mechanisms will commence at once. In this report, an attempt was made to assess the dynamics of an instilled nonsteroidal anti-inflammatory drug (NSAID), diflunisal, labeled with 1 MBq 99mTc followed by twenty minutes of scintigraphy. The results obtained with this labeled drug were compared with instillation of the same volume and activity of 99mTcO4-. Although the pertechnetate anion is an excellent and innocuous indicator for detecting the external lacrimal drainage system of the eye, it cannot visualize the internal structures. A clear scintigraphic difference was noted between labeled diflunisal and the pertechnetate anion. Scintigraphic activity surrounding the pupil of the eye provides evidence of visualization of the iris/ciliary body. This seems reasonable as the cyclooxygenase enzyme is located in this structure, and NSAIDs exert their mechanism of action via this complex. With this technology, visualization of some internal structures of the eye may be facilitated.
