Bao H Do, Presenter: Nothing to Disclose

Carina Mari Aparici MD, Abstract Co-Author: Nothing to Disclose

Andrew Quon MD, Abstract Co-Author: Nothing to Disclose

Jeffrey Tseng MD, Abstract Co-Author: Nothing to Disclose

Sandip Biswal MD, Abstract Co-Author: Nothing to Disclose

Understanding physiologic spinal cord glucose metabolism may provide insight regarding spinal cord diseases such as myelitis, trauma, and malignancy. For this reason, we have characterized the distribution 18F-FDG in the entire length of the spinal cord using whole body PET/CT.

A retrospective review of 100 (93 patients) whole body 18F-FDG PET/CT studies with non-CNS cancers was performed. Studies with vertebral marrow hyperplasia, spinal arthritis, cervical/thoracic kyphosis or motion artifact were excluded. Using the transaxial CT to define the cord, circular region of interests (ROIs) were placed that around the spinal cord and excluded the bony elements of the spine. Using this ROI, corresponding PET measurements were obtained at the midpoint of each vertebral body from C1 to L3. ROI measurements included total count/ROI, area, and standard uptake values (SUVs) (min, max and avg). Sagittal ROIs were obtained from the mid-sagittal plane of the cord and grouped into cervical, upper thoracic (T1-T6), lower thoracic (T7-T12), and lumbar regions. Transaxial measurements at L5, where no cord is present, served as an internal control.

Total counts/ROI ranged from 90 to 253. The mean L5 SUV average was 0.759. For comparative analysis, we defined the cord-to-background (CtB) SUV as the SUV to L5 (control) ratio. The mean CtB SUV average for transaxial C, T, L1-3, and L5 images were 2.201, 1.651, 1.283, and 0.759, respectively. The mean CtB SUV average for sagittal C, T1-6, T7-12, and L images were 2.440, 1.771, 1.739, and 1.171. Foci with relatively higher SUV were observed, most commonly at the level of T11/T12 and C7/T1. The lowest SUVs occurred at L5 (control).

CT-aided ROI placement minimized FDG contributions from the bony elements of the spine and allowed specific measurements of spinal cord SUV. SUV decreased caudally along the cord. Relative increase in SUV occurred most commonly at levels T11/T12 followed by C7/T1, perhaps related to increased neural density of the lumbar and cervical enlargements, respectively. These consistent findings promote the use of 18F-FDG-PET/CT in studying cord metabolism.

Do, B, Mari Aparici, C, Quon, A, Tseng, J, Biswal, S, Metabolic Profile of the Spinal Cord by Whole Body [18F]-2-deoxy-3-fluoro-d-glucose (18F-FDG) Positron Emission Tomography (PET)/Computed Tomography (CT) Imaging.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4419876.html