Thoracic high resolution CT using the modified VetMousetrap™ device is a feasible method for diagnosing canine idiopathic pulmonary fibrosis in awake West Highland White Terriers

Abstract

Canine idiopathic pulmonary fibrosis is a chronic, progressive interstitial lung disease particularly prevalent in West Highland White Terriers. In the present prospective pilot study, we evaluated the feasibility of modified VetMousetrap TM device in high resolution CT to detect idiopathic pulmonary fibrosis in West Highland White Terriers. Twelve awake West Highland White Terriers with canine idiopathic pulmonary fibrosis and 24 clinically healthy West Highland White Terriers were scanned using a helical dual slice scanner utilizing VetMousetrap TM device without or with minimal chemical restraint with butorphanol. Three evaluators blindly assessed the images for image quality and the presence of canine idiopathic pulmonary fibrosis related imaging findings such as ground glass opacity and reticular opacities. Additionally, the attenuation of the lung was quantified with ImageJ software using histogram analysis of density over the lung fields. Computed tomography was successfully completed and motion artifact ranked in statistical analysis barely noticeable to mild in all dogs. The agreement between imaging findings and clinical status was very good with overall value 0.91 and percentage of agreement of 94%. There was also very good intraobserver ( range = 0.79-0.91) and interobserver agreement ( = 0.94). Moderate to severe ground glass opacity was present in all affected dogs. In the ImageJ analysis, a significant difference in lung attenuation between the study groups was observed. We conclude that modified VetMousetrap TM device is applicable in diagnosing canine idiopathic pulmonary fibrosis in awake West Highland White Terriers avoiding anesthetic risk in these often severely hypoxic patients.

Minimal atelectasis and poorly aerated lung on thoracic CT images of normal dogs acquired under sedation

“…In one study, motion was ranked as barely noticeable to mild in all dogs and was not statistically different between normal dogs and dogs with diseased lungs when both groups were scanned awake or with sedation. 25 In another study, a statistical difference between motion artifact present on diseased dogs scanned under sedation versus those scanned under general anesthesia was found. 33 Yet in both groups, the majority of the scans were graded as mild.…”

“…34 Yet, recent studies demonstrated thoracic CT on sedated dogs was superior to radiographs at detecting evidence of blunt force trauma after vehicular accidents 24 and there is good agreement between abnormal CT findings and subject's clinical status in awake White Highland White Terriers with idiopathic pulmonary fibrosis. 25 Future studies should also be aimed at evaluating the indications for sedated CT scans and different sedation protocols to accommodate patients with medication limitations based on comorbidities.…”

“…Recent investigations into the feasibility and diagnostic quality of CT scans performed on sedated or awake animals-upper airway studies in dogs, thoracic studies in cats and dogs, and abdominal studies in dogs-have demonstrated that diagnostic quality studies are acheivable. [21][22][23][24][25] Objectives of the current study were to assess the image quality of thoracic CT scans performed with an MDCT scanner on dogs lacking pulmonary disease given injectable sedation by evaluating the lung volume, mean lung attenuation, and amount of poorly aerated and atelectatic lung. We hypothesized that scans performed using this method would have mean lung attenuation and lung volume measurements consistent with previously documented measurements for thoracic scans of anesthetized normal dogs.…”

Comparison between Image-Guided Transbronchial Cryobiopsies and Thoracoscopic Lung Biopsies in Canine Cadaver: A Pilot Study

“…In canine IPF, the most common CT findings are ground-glass opacity, mosaic attenuation, and reticular patterns, while traction bronchiectasis and honeycombing are rarely described and are associated with later stages of disease [ 7 , 8 , 15 , 16 , 17 ]. Due to the paucity of correlation data between CT and histopathological patterns for ILD in the veterinary literature, histopathology of peripheral lung is the gold standard for diagnosis, as imaging results in the absence of biopsy confirmation might be misleading [ 15 , 18 ].…”

Clinical features and outcome in 25 dogs with respiratory‐associated pulmonary hypertension treated with sildenafil

“…Groups 3 through 5 also have been commonly described in veterinary studies of PH, although definitive diagnosis of the underlying disease process related to PH for dogs in these groups is challenging because of the need for invasive testing including histopathology to confirm many of these disease processes. For example, pulmonary thromboembolism remains difficult to diagnose antemortem and can be found in dogs with normal d ‐dimer concentrations; tracheobronchomalacia (TBM) can require radiographic, fluoroscopic, and bronchoscopic assessment; and, pulmonary fibrosis requires histopathologic documentation, although high‐resolution computed tomography increasingly is used in the diagnosis . Clinically, PH has been reported in a number of these diseases with diagnosis based on clinical suspicion, signalment, physical examination findings, and diagnostic imaging .…”