AnalyzeDirect Timothy L. Menghini et al. Contrast-enhanced CT predictors of lymph nodal metastasis in dogs with oral melanoma Veterinary Radiology & Ultrasound.
Publication Date
June 9, 2023
How Analyze was Used
“Using commercial software (Analyze, Biomedical Imaging Resource), lymphocenters were defined as regions of interest. LC voxels, area (mm 2), volume (mm 3), and degree of attenuation (HU) were compared between groups.
Regions of interest data were calculated automatically using the Analyze software system and volume rendering algorithms. HU is the average of all voxel postcontrast attenuation measurements. A voxel is simply the 3D equivalent to a pixel, whereby its size is related to pixel size and slice thickness. Pixel size is equal to the field of view (FOV) divided by the matrix size. As slices were acquired contiguously, voxel depth was equal to slice thickness. As each ROI is made up of numerous cuboid shaped voxels, the software computes the ROI measurements using discrete mathematical formulae where: Area = total voxel length (mm) × width (mm); and Volume = area (mm2) × voxel depth (mm). This means for non-uniform shapes such as tumors or LNs, volume can be measured by quantifying the number of voxels within a 3D ROI. For example, in a scan with 512 × 512 matrix size, 200 mm FOV, and 0.7 mm slice thickness, each voxel represents a volume of ∼0.106812 mm3.”
Keywords
Canine, Mandibular, Melanoma, Metastasis, Node, Volume
Author Affiliation(s)
The University of Edinburgh, Scotland, UK
