Drees R, Johnson RA, Stepien RL, et al.
Introduction/Purpose: Cardiac angiography using multi-detector row computed tomography (MDCT) and cardiac magnetic resonance imaging (MRI) are emerging modalities for evaluating anatomy and function of the heart in dogs. Aim of this study was to evaluate two different anesthetic protocols for obtaining two-dimensional cardiac measurements using 64 MDCT and 3T MRI.
Methods: Ten healthy beagles were examined using 64-MDCT cardiac angiography and cardiac 3T MRI in one anesthetic episode on two separate days, randomly using Protocol A (fentanyl/midazolam/isoflurane) on one and Protocol B (dexmedetomedine/isoflurane) on the other. Anesthetic protocols and order of imaging modalities were randomized. The following two-dimensional measurements were obtained: systolic and diastolic interventricular septal- and left ventricular posterior wall thickness; left ventricular-, mitral annulus-, aortic-, pulmonary artery- and left atrial diameter. Fractional shortening, stroke volume and left atrium/aorta ratios were calculated. The paired Wilcoxon signed rank test was used to compare the results between anesthetic protocols; significance was set at P < 0.05.
Results: Cardiac 64-MDCT angiography and cardiac 3T exams were successfully performed in all dogs. No statistical differences were found between the two anesthetic protocols for the evaluated functional parameters when comparing within one modality.
Discussion/Conclusion: This study provides baseline information for two different anesthetic protocols for two-dimensional cardiac measurements in the dog using 64 MDCT and 3T MRI. Despite no significance found between the anesthetic protocols compared within one modality, an effect could be masked by small sample size or intersubject variation and care should be taken in concluding equality for the protocols. Further studies with a larger sample size and patients with functional or morphological abnormalities are indicated.