Quantitative assessment the longitudinal changes of pulmonary vascular counts in chronic obstructive pulmonary disease.

BACKGROUND: Chest computed tomography (CT) is a widely used method to assess morphological and dynamic abnormalities in chronic obstructive pulmonary disease (COPD). The small pulmonary vascular cross-section (CSA), quantitatively extracted from volumetric CT, is a reliable indicator for predicting pulmonary vascular changes. CSA is associated with the severity of symptoms, pulmonary function tests (PFT) and emphysema and in COPD patients the severity increases over time. We analyzed the correlation longitudinal changes in pulmonary vascular parameters with clinical parameters in COPD patients. MATERIALS AND METHODS: A total of 288 subjects with COPD were investigated during follow up period up to 6 years. CT images were classified into five subtypes from normal to severe emphysema according to percentage of low-attenuation areas less than -950 and -856 Hounsfield units (HU) on inspiratory and expiratory CT (LAA-950, LAA-856exp). Total number of vessels (Ntotal) and total number of vessels with area less than 5 mm2 (N<5 mm) per 1 cm2 of lung surface area (LSA) were measured at 6 mm from the pleural surface. RESULTS: Ntotal/LSA and N<5 mm/LSA changed from 1.16 ± 0.27 to 0.87 ± 0.2 and from 1.02 ± 0.22 to 0.78 ± 0.22, respectively, during Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage progression. Both parameters changed from normal to severe emphysema according to CT subtype from 1.39 ± 0.21 to 0.74 ± 0.17 and from 1.18 ± 0.19 to 0.67 ± 0.15, respectively. LAA-950 and LAA-856exp were negatively correlated with Ntotal/LSA (r = - 0.738, - 0.529) and N<5 mm /LSA (r = - 0.729, -- .497). On the other hand, pulmonary function test (PFT) results showed a weak correlation with Ntotal/LSA and N<5 mm/LSA (r = 0.205, 0.210). The depth in CT subtypes for longitudinal change both Ntotal/LSA and N<5 mm/LSA was (- 0.032, - 0.023) and (- 0.027) in normal and SAD, respectively. CONCLUSIONS: Quantitative computed tomography features faithfully reflected pulmonary vessel alterations, showing in particular that pulmonary vascular alteration started.

Computed tomography-based visual assessment of chronic obstructive pulmonary disease: comparison with pulmonary function test and quantitative computed tomography.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) has variable subtypes involving mixture of large airway inflammation, small airway disease, and emphysema. This study evaluated the relationship between visually assessed computed tomography (CT) subtypes and clinical/imaging characteristics. METHODS: In total, 452 participants were enrolled in this study between 2012 and 2017. Seven subtypes were defined by visual evaluation of CT images using Fleischner Society classification: normal, paraseptal emphysema (PSE), bronchial disease, and centrilobular emphysema (trace, mild, moderate and confluent/advanced destructive). The differences in several variables, including clinical, laboratory, spirometric, and quantitative CT features among CT-based visual subtypes, were compared using the chi-square tests and one-way analysis of variance. RESULTS: Subjects who had PSE had better forced expiratory volume in 1 second (FEV1) (P=0.03) percentage and higher lung density (P<0.05) than those with moderate to confluent/advanced destructive centrilobular emphysema. As the visual grade of centrilobular emphysema worsened, pulmonary function declined and modified Medical Research Council, COPD assessment test (CAT) score, and quantitative assessment (emphysema index and air trapping) increased. The bronchial subtype was associated with higher body mass index (BMI), better lung function and higher lung density. Participants with trace emphysema showed a rapid increase in functional small airway disease. CONCLUSIONS: Classifying subtypes using visual CT imaging features can reflect heterogeneity and pathological processes of COPD.

Assessment of global left ventricular function with dual-source computed tomography in patients with valvular heart disease.

BACKGROUND: Left ventricular (LV) function is a vital parameter for prognosis, therapy guidance, and follow-up of cardiovascular disease. Dual-source computed tomography (DSCT) provides an accurate analysis of global LV function. PURPOSE: To assess the performance of DSCT in the determination of global LV functional parameters in comparison with cardiovascular magnetic resonance (CMR) and two-dimensional transthoracic echocardiography (2D-TTE) in patients with valvular heart disease (VHD). MATERIAL AND METHODS: A total of 111 patients (58 men, mean age 49.9 years) with known VHD and who underwent DSCT, 2D-TTE, and CMR a period of 2 weeks before undergoing valve surgery were included in this study. LV end-systolic volume (ESV), end-diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF) were calculated by DSCT using the threshold-based technique, by 2D-TTE using a modified Simpson's method, and by CMR using Simpson's method. Agreement for parameters of LV global function was determined with the Pearson's correlation coefficient (r) and Bland-Altman analysis. All the DSCT and CMR data-sets were assessed independently by two readers. RESULTS: Fifty of the total 111 patients had aortic VHD, 29 patients had mitral VHD, and 32 patients had mixed aortic and mitral VHD. An excellent inter-observer agreement was seen for the assessment of global LV function using DSCT (r = 0.910-0.983) and CMR (r = 0.854-0.965). An excellent or good correlation (r = 0.93, 0.95, 0.87, and 0.71, respectively, P < 0.001) was noted between the DSCT and 2D-TTE values for EDV, ESV, SV, and EF. EDV (33.7 mL, P < 0.001), ESV (12.1 mL, P < 0.001), SV (21.2 mL, P < 0.001), and EF (1.6%, P = 0.019) were significantly overestimated by DSCT when compared with 2D-TTE. An excellent correlation (r = 0.96, 0.97, 0.91, and 0.94, respectively, P < 0.001) between DSCT and CMR was seen in the evaluation of EDV, ESV, SV, and EF. EDV (15.9 mL, P < 0.001), ESV (7.3 mL, P < 0.001), and SV (8.5 mL, P < 0.001) were significantly underestimated, but EF (1.1%, P = 0.002) was significantly overestimated by DSCT when compared with CMR. CONCLUSION: Our study showed that DSCT measurements of global LV function using the threshold-based technique were highly reproducible and compared more favorably with CMR measurements using Simpson's method than those of 2D-TTE using the modified Simpson's method. DSCT enables accurate quantification of global LV function in patients with VHD.