Automated measurement of myofiber disarray in transgenic mice with ventricular expression of ras

Quantitative assessment of myofiber disarray associated with diseases such as familial hypertrophic cardiomyopathy (FHC) can be performed by estimatin g local angular deviation of fiber orientation in histologic sections. The large number of measurements required to estimate angular deviation prohibi ts manual measurement. We describe methods for automated measurement of loc al orientation and angular deviation in tissue sections from transgenic mic e with ventricular expression of ras, proposed as a model of FHC. Images of histologic tissue sections from normal and transgenic mice were a nalyzed using image processing techniques to estimate local orientation of myofibers. Results from the automated methods were compared with manual mea surements. Automated methods estimated differing mean orientation in 7-20% of normal s ections and 17-29% of transgenic tissue sections with differing dispersions in 23-30% of normal sections and 25% of transgenic tissue sections. Automa ted methods estimate 24.47 +/- 13.03% of total ventricular mass affected by disarray that is comparable to a previous estimate of 21.7% in the same mo use model. Automated methods are a rapid and accurate alternative to manual measuremen t for estimation of mean orientation and angular deviation in myocardial ti ssue sections. Differences between manual and automated methods may be attr ibuted to the substantially larger number of measurements made by automated methods. Automated methods are particularly appropriate for use in determi ning local variation in orientation such as focal myofiber disarray associa ted with FHC. The generality of these methods suggests they may have use in other biological fields such as quantifying cellular alignment. Anat Rec. 252:612-625, 1998. (C) 1998 Wiley-Liss, Inc.