A covenant or agreement between two or more persons, with a lawful consideration or cause. Jacob. A deliberate engagement between competent parties, upon a legal consideration, to do or abstain from doing, some act. Wharton.
Enhancing means that the mass brightens up with contrast, meaning that there is a lot of blood vessels feeding the mass. These are imaging terms that radiologists use to describe a picture. <br /><br /> Inhomogeneous means that the whole mass does not look the same; the best I can describe is that it looks speckled. For example, a cyst that is filled with fluid will be homogeneous. Every part of what's inside the cyst will look identical, because it's just fluid in there.
Physics and Chemistry. A heterogeneous mixture is a mixture of two or more compounds. Examples are: mixtures of sand and water or sand and iron filings, a conglomerate rock, water and oil, a salad, trail mix, and concrete (not cement). h_i = \frac{(c_i - c_\text{batch})m_i}{c_\text{batch} m_\text{aver}} .