Diagnostic Accuracy of PET/CT and Contrast Enhanced CT in Patients With Suspected Infected Aortic Aneurysms

• Published in: European journal of vascular and endovascular surgery Vol. 59; no. 6; pp. 972 - 981
• Main Authors: Husmann, Lars, Huellner, Martin W., Ledergerber, Bruno, Eberhard, Nadia, Kaelin, Marisa B., Anagnostopoulos, Alexia, Kudura, Ken, Burger, Irene A., Mestres, Carlos-A., Rancic, Zoran, Hasse, Barbara, Anagnostopoulos, A., Hasse (PI), B., Eberhard, N., Hoffmann, M., Husmann, L., Kopp, R., Ledergerber, B., Rancic, Z., Mestres, C.A., Zbinden, R., Zinkernagel, A.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.06.2020
• Subjects: 18F-FDG; Computed tomography angiography; Data accuracy; Infected aneurysm; Infection; PET-CT; Computed tomography angiography; Infection; PET-CT; 18F-FDG; Infected aneurysm; Data accuracy
• ISSN: 1078-5884; 1532-2165
• DOI: 10.1016/j.ejvs.2020.01.032

Infected aortic aneurysms are highly lethal, and management is very demanding, requiring an early diagnosis. The aim of this study was to evaluate the diagnostic accuracy of positron emission tomography/computed tomography with 18F-fluorodeoxyglucose (PET/CT) and contrast enhanced CT (CE-CT) in patients with suspected infected aortic aneurysms. PET/CT was performed in patients with clinically suspected infected aortic aneurysms, and additional CE-CT was performed if feasible. Diagnostic accuracy was assessed by two independent readers using a four point grading score for both imaging modalities. Maximum standardised uptake values (SUVmax) were calculated for quantitative measurements of metabolic activity in PET/CT. The reference standard was a combination of clinical presentation, laboratory findings, and imaging. Ten patients were included prospectively in the study, 24 retrospectively; 16 patients (47%) prior to the start of antimicrobial treatment and all 34 patients prior to any vascular intervention. Thirteen of the 34 patients had an infected aortic aneurysm (38%). Proven infected aortic aneurysms were all metabolically active on PET/CT with a median SUVmax of 6.6 (interquartile range 4.7–21.8). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT for the diagnosis of infected aortic aneurysm was 100%, 71%, 68%, 100%, and 82%, for reader 1 and 85%, 71%, 65%, 88%, and 77%, for reader 2. Respective values for CE-CT, performed in 20 patients (59%), were 63%, 75%, 63%, 75%, and 70%, for reader 1 and 88%, 50%, 54%, 86%, and 65%, for reader 2. The diagnostic accuracy of PET/CT in the detection of infected aortic aneurysms (n = 13) is high, and higher than CE-CT. While PET/CT demonstrates an excellent sensitivity, its specificity is hampered because of false positive findings.