title: Frequency of pulmonary mineralization and hypoxemia in 21 dogs with pituitary-dependent hyperadrenocorticism.
abstract: The purpose of this study was to determine the frequency of hypoxemia and pulmonary mineralization using 99mTc-methylene diphosphonate (99mTc-MDP) in dogs with pituitary-dependent hyperadrenocorticism (PDH). Twenty-one dogs with PDH were prospectively evaluated using thoracic radiography, arterial blood gas analysis, and bone phase and pulmonary perfusion scintigraphy (using 99mTc-macro-aggregated albumin [99mTc-MAA]). The radiographs and bone and perfusion studies were evaluated subjectively. An averaged quantitative count density ratio was calculated between the thorax and cranial thoraco-lumbar vertebrae from lateral thoracic 99mTc-MDP images. Thoracic:vertebral ratios were calculated using 99mTc-MDP studies from 21 control dogs. The thoracic:vertebral ratios were compared between the 2 groups (PDH and control). The mean age (+/-SD) of the 21 PDH dogs was 10.2 (+/-3) years, whereas the mean age of the control group was 9.8 (+/-3) years. Seven of the 21 dogs with PDH were hypoxemic (defined as an arterial partial pressure of oxygen [PaO2] < 80 mm Hg) with an average PaO2 (+/-SD) of 62 (+/-15) mm Hg. Of the 7 hypoxemic dogs, 2 were found to have pulmonary mineralization based on bone scintigraphic images. Pulmonary perfusion abnormalities were not identified using 99mTc-MAA in any of the 21 PDH dogs. Six PDH dogs had an abnormal interstitial pulmonary pattern and 5 of these dogs were hypoxemic. The average quantitative thoracic:vertebral ratio was not significantly different between the PDH and control dogs (0.5 +/- 0.4 versus 0.4 +/- 0.1, P = .16). Causes of hypoxemia other than pulmonary thromboembolism should be considered in dogs with PDH. Pulmonary mineralization may contribute to hypoxemia in dogs with PDH.
authors.affiliation: Department of Anatomy, Physiological Sciences and Radiology, North Carolina State University, College of Veterinary Medicine, Raleigh, USA. bkberry@iol15.com
authors.forename: C R
authors.initials: CR
authors.lastname: Berry
authors.forename: E C
authors.initials: EC
authors.lastname: Hawkins
authors.forename: K J
authors.initials: KJ
authors.lastname: Hurley
authors.forename: K
authors.initials: K
authors.lastname: Monce
mesh_terms: D000303:Adrenal Cortex Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000662:veterinary*; D000818:Animals; D004283:Dog Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004285:Dogs; D005260:Female; D000860:Hypoxia / Q000209:etiology / Q000662:veterinary*; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging / Q000662:veterinary*; D008297:Male; D008903:Minerals / Q000378:metabolism*; D010900:Pituitary Diseases / Q000000981:diagnostic imaging / Q000662:veterinary*; D011655:Pulmonary Embolism / Q000175:diagnosis / Q000662:veterinary; D011877:Radionuclide Imaging; D013669:Technetium Tc 99m Medronate
chemical_list: D008903:Minerals; D013669:Technetium Tc 99m Medronate