Objective—To evaluate the accuracy and reproducibility of left ventricular (LV) volumetric and function variables determined via contrast-enhanced cardiac CT and cardiac MRI in healthy dogs.
Animals—10 healthy Beagles.
Procedures—Cardiac MRI and cardiac CT were performed in anesthetized Beagles; both examinations were conducted within a 2-hour period. Cardiac MRI was performed with a 3.0-T magnet, and contrast-enhanced cardiac CT was performed with a 64-row detector CT machine. Data sets were acquired during apnea with simultaneous ECG gating. Short-axis images were created to determine functional variables via the Simpson method.
Results—Cardiac CT values for mean end-diastolic and end-systolic LV volumes had excellent correlation (r = 0.95) with cardiac MRI measurements, whereas LV stroke volume (r = 0.67) and LV ejection fraction (r = 0.75) had good correlations. The only variable that differed significantly between imaging modalities was end-diastolic LV volume. For each pair of values, Bland-Altman analysis revealed good limits of agreement.
Conclusions and Clinical Relevance—The 3-D modalities cardiac CT and cardiac MRI were excellent techniques for use in assessing LV functional variables. Similar results were obtained for LV volume and function variables via both techniques. The major disadvantage of these modalities was the need to anesthetize the dogs for the examinations.
Objective—To quantify left ventricle (LV) volumes by use of 1-D, 2-D, and 3-D echocardiography versus MRI in dogs.
Animals—10 healthy Beagles.
Procedures—During anesthesia, each dog underwent an echocardiographic examination via the Teichholz method, performed on the basis of standard M-mode frames (1-D); the monoplane Simpson method of disk (via 2-D loops); real-time triplane echocardiography (RTTPE) with a 3-D probe; and real-time 3-D echocardiography with a 3-D probe. Afterward, cardiac MRI was performed. Values for the LV end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) were compared between each echocardiographic method and the reference method (cardiac MRI).
Results—No significant differences for EDV, ESV, and EF were detected between RTTPE and cardiac MRI. Excellent correlations (r = 0.97, 0.98, and 0.95 for EDV, ESV, and EF, respectively) were found between RTTPE and values for cardiac MRI. The other echocardiographic methods yielded values significantly different from cardiac MRI and results correlated less well with results of cardiac MRI for EDV, ESV, and EF. Use of the Teichholz method resulted in LV volume overestimation, whereas the Simpson method of disk and real-time 3-D echocardiography significantly underestimated LV volumes.
Conclusions and Clinical Relevance—Use of RTTPE yielded excellent correlations and nonsignificant differences with cardiac MRI and is a suitable method for routine veterinary cardiac examination.