Quantitative Method for Diagnosis of Osteopenia in Cats by Pixel Value Evaluation

Objective: To present a quantitative method for diagnosis of osteopenia in cats by the mean of pixel value evaluation in digital radiography.

Procedures: During this retrospective case-series study, 89 radiographs which had general osteopenic signs subjectively were selected, assigned as a patient group,
from diagnostic imaging archive of diagnostic imaging department of the Small Animal Hospital, Faculty of veterinary Medicine, University of Tehran, Iran. Eighty
nine radiographs without osteopenic signs were also selected as a control group. Region of interest (ROI) about 0.1 cm2 was chosen for quantitative evaluation in lateral radiographs at the location of humerous/femur diaphysis, adjacent soft tissue around diaphysis and adjacent empty area in each cases from both groups. Mean and standard deviation of pixel value of each ROI was recorded. Then the ratio of soft tissue minus bone pixel value and soft tissue pixel value ((B-S)/S), soft tissue minus bone pixel value and adjacent empty area pixel value ((B-S)/E), bone and adjacent soft tissue (B/S); bone and adjacent empty area (B/E) were calculated for elimination of technical differences between individuals in both groups. Finally, groups were compared statistically. […]