Surprenant E L, Spellberg R D
Radiology. 1975 Oct;117(1):99-104. doi: 10.1148/117.1.99.
Supine tidal volume regional ventilation and perfusion images obtained in the posterior and lateral projections demonstrated several alterations in patients with mitral valve disease. Reversal of the gravitational perfusion gradient correlated with pulmonary venous and arterial hypertension; the supine studies reliably distinguished normal subjects from mitral patients. The reversed gradient was from posterior-base to anterior-apex. Focal defects were common and contributed to the reversed gradient in 50% of patients. Perfusion defects larger than those of ventilation, simulating emboli, occurred in 32%, particularly in the middle lobe and superior segment areas. Relative hypoventilation of the left lung was seen in 44% of these patients.
仰卧位潮气容积区域通气和灌注图像在前后位和侧位投照下的结果显示，二尖瓣疾病患者存在多种改变。重力灌注梯度的逆转与肺静脉和肺动脉高压相关；仰卧位研究能够可靠地将正常人与二尖瓣疾病患者区分开来。逆转梯度是从后基底到前尖部。局灶性缺损很常见，50%的患者出现这种情况并导致了梯度逆转。32%的患者出现灌注缺损大于通气缺损，类似栓子，尤其在中叶和上段区域。44%的这些患者可见左肺相对通气不足。
