Educational calculators only. Each result is a number plus the population, view, and method behind any published figure. This page does not diagnose a patient, stage a disease, or recommend treatment. It is not specialist sign-off.
Measure the long axis from the ventral carina to the apex, and the short axis perpendicular at the widest point. Transpose each from the cranial edge of T4. VLAS, in dogs, runs from the centre of the ventral carina to the caudal left atrium at the dorsal caudal vena cava, then from cranial T4. Sources: Buchanan & Bücheler 1995, Litster & Buchanan 2000, Lamb et al. 2001, Jepsen-Grant et al. 2013, Bavegems et al. 2005, Malcolm et al. 2018, Baisan & Vulpe 2024, Keene et al. 2019.
Dog only. For the 1.6 figure, LA and Ao are the right-parasternal short-axis measurement in early diastole, same units. LVIDd in the normalised formula is the 2D short-axis-guided M-mode diameter. LVIDDN = LVIDd (cm) / kg0.294. Fractional shortening (%) = [(LVIDd − LVIDs) / LVIDd] × 100 and is load-dependent. Keene et al. 2019, Hansson et al. 2002, Cornell et al. 2004. This page does not recommend treatment.
Dog kidney: sagittal length divided by aortic luminal diameter. Body weight is not the denominator. Mareschal et al. 2007 said renal size should be considered reduced if K/Ao is under 5.5 and increased when over 9.1, “based on 95% confidence intervals,” in 92 dogs without clinical evidence of renal disease. That wording is not a patient diagnosis, and the aortic landmark is not restated here. Dog adrenal: Bento et al. 2016 (non-adrenal illness) and the review-reported Soulsby et al. 2015 suggestions quoted by Huynh & Berry. Cat adrenal: Combes et al. 2013. A feline absolute kidney-length band was not verified, so none is applied.
The scale is defined so distilled water at STP is 0 HU and air at STP is −1000 HU. The bar only locates the number between those anchors and +2000. A single ROI is not a tissue type: values overlap and depend on kilovoltage, reconstruction, and where the ROI sits. Hounsfield unit, Radiopaedia.
Measure the full wall perpendicular to the lumen. Dog jejunum and some duodenal figures depend on weight: Delaney, O'Brien & Waller 2003. Cat figures are study means, not upper limits: Newell et al. 1999. Lost layering is an image finding. This page does not name a disease from thickness or layering.
Prefilled text is a teaching example of report structure, not a patient and not a prescription.