The diseases have been categorized as patches (cause dead spots or patches in the lawn), rings (cause rings of dead or affected grass), or leaf blight (affect individual blades of grass, often over a wide area and no distinct patch or ring pattern may be noticeable).
PVR, abbreviation for pulmonary vascular resistance. To measure changes in blood vessel size or changes in gas volume in the lungs to assist in diagnosing diseases such as deep vein thrombosis (DVT), chronic obstructive pulmonary disease (COPD), and some peripheral vascular disorders. Veins, arteries, and lungs. None.
Periventricular leukomalacia (PVL) is a form of white-matter brain injury, characterized by the necrosis (more often coagulation) of white matter near the lateral ventricles.eriventricular leukomalacia involves death of the white matter surrounding the lateral ventricles in fetuses and infants.