title: Imaging of acute and chronic aortic dissection by 18F-FDG PET/CT.
abstract: By conventional imaging modalities, the discrimination between acute and chronic aortic dissection (AD) for surgical risk evaluation is not possible. However, acute and chronic stable AD potentially may be distinguished by detection of reparatory hypermetabolism in the lacerated aortic wall of acute AD using (18)F-FDG PET/CT. In this study, we analyzed the (18)F-FDG uptake in the aortic wall of acute and chronic stable AD.
  
  
  METHODS
  Eighteen patients with acute (n = 9), symptomatic progressive (n = 2), or known chronic stable (n = 7) type B AD underwent (18)F-FDG PET/CT. Images were analyzed qualitatively and quantitatively considering (18)F-FDG uptake patterns and the standardized uptake values (SUVs) of the aortic wall, dissection membrane, and luminal (18)F-FDG activity. The SUV ratio (maximum SUV in the aorta divided by mean SUV in the blood pool) was calculated to relativize individual luminal (18)F-FDG spillover effects.
  
  
  RESULTS
  In contrast to chronic stable AD, all acute or acute progressive AD showed accentuated (18)F-FDG uptake at the injured aortic wall or dissection membrane. The maximum SUV of the dissection membrane or aortic wall was significantly higher (P = 0.02) in acute AD than in chronic stable AD. Thereby, SUV varied from 3.03 to 4.64 (average maximum SUV, 3.84 +/- 0.51) for the dissection membrane and from 2.22 to 4.60 (average maximum SUV, 2.94 +/- 0.81) for the aortic wall, with false-negative and false-positive outliers. The discrimination between acute and stable AD was improved significantly (P < 0.001), and false-positive or -negative outliers were eliminated, using the SUV ratio method.
  
  
  CONCLUSIONS
  Our results indicate that (18)F-FDG PET/CT might be useful in differentiation of acute from chronic AD in clinically unclear cases. However, larger studies are needed to confirm our preliminary results.
authors.affiliation: Clinic for Vascular Surgery, Klinikum-rechts-der-Isar, Technische Universität München, München, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Reeps
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Pelisek
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Bundschuh
authors.forename: Manuela
authors.initials: M
authors.lastname: Gurdan
authors.forename: Alexander
authors.initials: A
authors.lastname: Zimmermann
authors.forename: Stefan
authors.initials: S
authors.lastname: Ockert
authors.forename: Martin
authors.initials: M
authors.lastname: Dobritz
authors.forename: Hans-Henning
authors.initials: HH
authors.lastname: Eckstein
authors.forename: Markus
authors.initials: M
authors.lastname: Essler
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000784:Aortic Dissection / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging; D001014:Aortic Aneurysm / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D002908:Chronic Disease; D003937:Diagnosis, Differential; D018450:Disease Progression; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D019275:Radiopharmaceuticals; C036309:fibrin fragment D; D019788:Fluorodeoxyglucose F18