Quantitative assessment of glucose metabolism in the vessel wall of abdominal aortic aneurysms: correlation with histology and role of partial volume correction

Int J Cardiovasc Imaging. 2013 Feb;29(2):505-12. doi: 10.1007/s10554-012-0090-9. Epub 2012 Jul 7.

Abstract

Inflammatory-proteolytic processes in the vessel wall are essential in the pathophysiology of abdominal aortic aneurysm (AAA). It has been demonstrated that, (18)F-FDG-PET/CT may be useful for detection of pathological wall metabolism and therefore risk stratification. Quantification of the FDG-uptake in AAA wall is hampered by partial-volume (PV)-effects. For correction and accurate quantitative (18)F-FDG-uptake analysis we designed and validated a novel IDL-based software in correlation to phantom studies, histopathology and clinical presentation of AAA patients. For in vivo studies 23 patients with symptomatic and asymptomatic AAA underwent (18)F-FDG-PET/CT before surgery. In areas with (18)F-FDG-uptake the maximum and mean standardized uptake values in the vessel wall with (PVC-SUV(max), PVC-SUV(mean)) and without (SUV(max), SUV(mean)) PV-correction were determined. Results were correlated with clinical presentation, corresponding macrophage-infiltration and MMP-2- and -9-expression in surgical specimens. In patients, SUV(max), SUV(mean) as well as PVC-SUV(max) or PVC-SUV(mean) enabled a highly significant (p < 0.005) discrimination of symptomatic and asymptomatic AAA. Uncorrected and corrected SUVs showed comparable correlations with macrophage-infiltration and MMP-9 expression. No correlation of (18)F-FDG-uptake and MMP-2 was found. In vivo correlations of detected FDG-uptake with clinical and histological results showed comparable results for corrected and uncorrected SUVs. PV-correction is not mandatory for qualitative clinical assessment of glucose metabolism in the vessel wall of AAA-patients but may be necessary to establish quantitative cut off values to stratify patients for aneurysm repair.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aorta, Abdominal / diagnostic imaging*
  • Aorta, Abdominal / enzymology
  • Aorta, Abdominal / metabolism
  • Aortic Aneurysm, Abdominal / diagnostic imaging*
  • Aortic Aneurysm, Abdominal / enzymology
  • Aortic Aneurysm, Abdominal / metabolism
  • Female
  • Fluorodeoxyglucose F18* / metabolism
  • Humans
  • Image Interpretation, Computer-Assisted*
  • Immunohistochemistry
  • Linear Models
  • Macrophages / metabolism
  • Male
  • Matrix Metalloproteinase 2 / analysis
  • Matrix Metalloproteinase 9 / analysis
  • Middle Aged
  • Multimodal Imaging* / instrumentation
  • Phantoms, Imaging
  • Positron-Emission Tomography*
  • Predictive Value of Tests
  • Radiopharmaceuticals* / metabolism
  • Reproducibility of Results
  • Software Validation*
  • Tomography, X-Ray Computed*

Substances

  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18
  • MMP2 protein, human
  • Matrix Metalloproteinase 2
  • MMP9 protein, human
  • Matrix Metalloproteinase 9