Harris Benjamin, Bailey Dale L, Chicco Peter, Bailey Elizabeth A, Roach Paul J, King Gregory G
Department of Respiratory Medicine, Royal North Shore Hospital, St Leonards, Sydney, Australia.
Clin Physiol Funct Imaging. 2008 Jan;28(1):14-26. doi: 10.1111/j.1475-097X.2007.00767.x.
Lung scintigraphy using single photon emission computed tomography (SPECT) allows accurate regional measurement of the ventilation/perfusion (V/Q) relationship. Objective V/Q analysis has been shown to be useful in the diagnosis of pulmonary embolism (PE). By using anatomical information provided by co-registered computed tomography, we describe methodology for determining the extent of V/Q heterogeneity at a lobar level. We investigate this methodology using simulated data, and demonstrate its potential application in the clinical setting of PE.
Data representing an incremental perfusion defect involving the right lung, together with an unaffected ventilation dataset, were modelled using Monte Carlo simulation. For each increase in the size of the perfusion defect, the whole lung V/Q relationship was objectively determined. In addition, using an image mask of the pulmonary lobes, lobar V/Q relationships were also determined. V/Q heterogeneity was characterized using the log(10) standard deviation of the V/Q ratio (log SDVQR), ventilation (log SDV) and perfusion (log SDQ) distributions. Finally, this methodology was explored in clinical cases.
As an increasing number of segments were involved by perfusion defects, there was a progressive increase in all objective parameters of V/Q heterogeneity. The relative change was greatest for log SDV. Analysis of both the simulated and clinical studies demonstrated sensitive changes in the lobar V/Q profiles to the presence of PE.
Segmentation and analysis of SPECT ventilation-perfusion scintigraphy at a lobar level can be used to quantify regional V/Q relationships. This objective methodology is sensitive to the presence of PE, and may be useful in a clinical setting.
使用单光子发射计算机断层扫描（SPECT）进行肺闪烁扫描可准确测量通气/灌注（V/Q）关系的区域情况。客观V/Q分析已被证明对肺栓塞（PE）的诊断有用。通过使用与计算机断层扫描共同配准提供的解剖学信息，我们描述了在叶水平确定V/Q异质性程度的方法。我们使用模拟数据研究了这种方法，并证明了其在PE临床环境中的潜在应用。
使用蒙特卡罗模拟对代表右肺渐进性灌注缺损的数据以及未受影响的通气数据集进行建模。对于灌注缺损大小的每次增加，客观确定全肺V/Q关系。此外，使用肺叶的图像掩膜，还确定叶V/Q关系。使用V/Q比值的对数（10）标准差（log SDVQR）、通气（log SDV）和灌注（log SDQ）分布来表征V/Q异质性。最后，在临床病例中探索了这种方法。
随着越来越多的节段出现灌注缺损，V/Q异质性的所有客观参数都逐渐增加。log SDV的相对变化最大。模拟研究和临床研究均表明，叶V/Q曲线对PE的存在有敏感变化。
在叶水平对SPECT通气-灌注闪烁扫描进行分割和分析可用于量化区域V/Q关系。这种客观方法对PE的存在敏感，可能在临床环境中有用。
