Meignan M, Rosso J, Petitprez P, Cinotti L, Harf A, Simonneau G, Duroux P, Galle P
Service de Médecine nucléaire, Hôpital Henri Mondor, Créteil.
Presse Med. 1987 Sep 12;16(29):1401-4.
Ventilation perfusion scanning fails to diagnose pulmonary embolism in matched defects. In 61 patients (19 with pulmonary embolism proved by angiography, 32 with chronic obstructive lung disease and 10 with acute bacterial pneumonia) we computed the ventilation perfusion ratio (V/Q) in these matched defects, using Krypton 81 m. This analysis demonstrated that the diagnosis of pulmonary embolism could be made with a specificity of 100% when the V/Q ratio was greater than 1.2 in the matched defects. Pulmonary embolism was characterized by a perfusion defect with a high V/Q ratio, even in Laennec infarction. In contrast, the analysis excluded the diagnosis of pulmonary embolism and suggested another disease when the V/Q was less than 0.95 with a specificity of 95%. Perfusion defects in acute pneumonia always had a V/Q less than 1. The diagnosis remained difficult in chronic obstructive lung disease when pulmonary embolism was suspected on subsegmental defects. Nevertheless this could be solved in about 50% of the cases by quantitative analysis. We feel, therefore, that ventilation perfusion scanning should be quantified by V/Q analysis to improve the diagnosis of pulmonary embolism.
通气灌注扫描无法诊断出匹配性缺损中的肺栓塞。在61例患者中（19例经血管造影证实患有肺栓塞，32例患有慢性阻塞性肺疾病，10例患有急性细菌性肺炎），我们使用氪81m计算了这些匹配性缺损中的通气灌注比（V/Q）。该分析表明，当匹配性缺损中的V/Q比大于1.2时，肺栓塞的诊断特异性可达100%。肺栓塞的特征是灌注缺损且V/Q比高，即使在Laennec梗死中也是如此。相比之下，当V/Q小于0.95时，分析排除了肺栓塞的诊断，并以95%的特异性提示了另一种疾病。急性肺炎中的灌注缺损V/Q总是小于1。当怀疑亚段性缺损存在肺栓塞时，慢性阻塞性肺疾病的诊断仍然困难。然而，通过定量分析，约50%的病例可以解决这个问题。因此，我们认为通气灌注扫描应通过V/Q分析进行量化，以提高肺栓塞的诊断水平。
