The cardio-thoracic ratio, expressed as a percentage, is the ratio between the maximum transverse diameter of the heart and the maximum width of the thorax . 心胸比率用百分率表示,是心脏最大横径和胸廓最大宽径的比率。
Width maximum width of the string in pixels 字符串的最大宽度(以像素为单位) 。