High-resolution cardiac imaging and fiber analysis methods are desired for deeper understanding cardiac anatomy. Although refraction-contrast X-ray CT (RCT) has high contrast for soft tissues, its scanning cost is very high. On the other hand, micro-focus X-ray CT (μCT) is a modality that is commercially available with lower cost, but its contrast for soft tissue is not as high as RCT. To investigate the efficacy of μCT for fiber analysis, we scanned a common rabbit heart with both modalities with our original protocol of preparing materials, and compared their image-based analysis results. Their results were very similar, with correlation coefficient of 0.95. We confirmed that µCT volumes prepared by our protocol are useful for fiber analysis as well as RCT.