Generation of ventilation/perfusion ratio map in surgical patients by dual-energy CT after xenon inhalation and intravenous contrast media

Abstract

BackgroundWhile many studies have evaluated the change in lung volume before and after lung resection and correlated this with pulmonary function test results, there is very little evidence on the changes in ventilation perfusion ratio (V/Q) before versus after lung resection. In the present pilot study, we evaluated if V/Q mapping can be constructed using dual energy CT images.MethodsThirty-one lung cancer patients planned for pulmonary resection were included in this study. To evaluate ventilation, Xenon-enhanced CT was performed. This was immediately followed by perfusion CT. The two images were registered manually as well as using dedicated softwares, and division between ventilation pixels and perfusion pixels were done to produce the V/Q map. Also, in order to characterize the distribution of the V/Q, the following numerical indices were calculated; mean, median, mode, standard deviation (SD), coefficient of variation (CV), skewness, kurtosis, and fractal dimension (FD). Pulmonary function tests and blood gas parameters were measured using standard institutional procedures.ResultsIn the whole group, VC, %VC, and FEV1 decreased significantly after resection. FEV1.0% was increased significantly after resection. No significant changes were seen in PaO2, PaCO2, and DLCO/VA before and after resection. The mean, median, mode, SD, skewness, kurtosis and FD of the V/Q did not change significantly before and after resection. A marginal but significant decrease in CV was seen before versus after resection.ConclusionsOverall, it was considered that the V/Q maps could be adequately generated in this study. With further accumulation of data, V/Q map generated by dual energy CT may become one of the potentially useful tools for functional lung imaging.Trial registrationThis trial was registered in University Medical Information Network in Japan (UMIN000010023) on 13Feb2013.

Thymoma and Thymic Carcinoma: Surgical Resection and Multidisciplinary Treatment

“…Due to the complex anatomy of the mediastinum, it is easy to involve surrounding vital structures in a procedure for a locally advanced thymic tumor; this makes the procedure unpredictable and broad. The types of surgery for cases that involve adjacent anatomies to the thymic tumor are listed as follows: If a vascular structure is involved, such as a replacement of the vena cava [ 50 ] or complicated replacement of the aortic arch and its branches [ 51 ]; If a lung is involved, such as lung resection [ 52 ] or extrapleural pneumonectomy [ 53 ]; Specific surgical incisions, such as the common median sternotomy [ 14 ] or the clamshell incision [ 54 ]. …”

“…Specific surgical incisions, such as the common median sternotomy [ 14 ] or the clamshell incision [ 54 ].…”

Improving radiation physics, tumor visualisation, and treatment quantification in radiotherapy with spectral or dual‐energy CT

“…By combining these data with spectral iodine perfusion scans, a ventilation/perfusion CT can be constructed. 207,208 Since iodine and xenon have similar attenuating features, it is not possible to discriminate them on a single spectral CT. However, by replacing iodine with gadolinium as an intravenous contrast agent, it has been demonstrated that it is feasible to acquire a ventilation/perfusion CT with one spectral scan through threematerial differentiation.…”

Prognosis-Based Early Intervention Strategies to Resolve Exacerbation and Progressive Lung Function Decline in Cystic Fibrosis

“…Chest and sinus CT is typically used in CF to detect early lung disease/bronchiectasis and mucus-plugging, respectively [ 30 , 37 ]. Moreover, HRCT is used for detecting the impact of exacerbations and lung disease progression, where CT-based functional analysis using 3D reconstruction of the airway and pulmonary vasculature allows the quantification of airflow obstruction, changes in airway size, and/or blood volume in pulmonary vasculature [ 34 , 55 , 56 , 57 ]. Similarly, advances in magnetic resonance imaging (MRI)-based functional imaging and X-ray-fluoroscopy-based ventilation and lung heterogeneity analysis allow the quantification of regional lung function changes to predict prognosis and efficacy of interventions [ 28 , 29 , 30 , 34 , 55 , 57 ].…”