Pulmonary hypertension is a fatal condition in many cases. A prerequisite for better treatment is an increased understanding of pathophysiology and lung microanatomy. Until now, no satisfactory 3D imaging methods have been available. Further, the goal is to create automated measurement of the thickening of lung vessels. The methods used today are very time consuming and ineffective. Better 3D imaging of the heart in animal models will also help us understand why certain heart disease occurs.