Prognostic value of coexisting conditions and complications in pleuroparenchymal fibroelastosis: a single-center retrospective study.

BACKGROUND: Pleuroparenchymal fibroelastosis (PPFE) is a rare idiopathic interstitial lung disease (ILD) characterized by subpleural parenchymal fibrosis and elastosis mainly in the upper lobes. PPFE occurs in a secondary form that overlaps with underlying medical conditions or complications. This study evaluated the clinical impact of coexisting factors on the survival of patients with PPFE. METHODS: Fifty-five PPFE patients were retrospectively evaluated. The patients' diagnoses were categorized as "idiopathic PPFE" with no known cause or "secondary PPFE" with underlying medical conditions or complications. The clinical characteristics and survival rates of these groups were compared. RESULTS: Twenty-eight patients (50.9%) were diagnosed with idiopathic PPFE and 27 (49.1%) with secondary PPFE, including cases of occupational dust exposure, connective tissue disease (CTD), post-hematopoietic stem cell transplantation (HSCT), and a family history of ILD. The idiopathic and secondary PPFE groups had similar clinical features, laboratory tests, and pulmonary function profiles, including a low body mass index, normal Krebs von den Lungen-6, high surfactant protein-D, and high residual volume/total lung capacity. In the secondary PPFE group, post-HSCT was associated with a worse prognosis, and CTD was associated with better prognosis. A multivariate analysis demonstrated that post-HSCT and a reduced forced vital capacity were significantly associated with a worsened survival in patients with PPFE. CONCLUSIONS: The prognosis of PPFE is highly influenced by underlying medical conditions or complications. Patients with post-HSCT PPFE should be monitored particularly closely, as they are at higher risk of a poor prognosis than others.

Benefit-Risk Profile of P2X3 Receptor Antagonists for Treatment of Chronic Cough: Dose-Response Model-Based Network Meta-Analysis.

BACKGROUND: Refractory or unexplained chronic cough disrupts quality of life and burdens health care systems around the world. The P2X3 receptor antagonist gefapixant is approved in many countries for its antitussive effects, but taste disturbances are a common adverse effect. Four newer, more selective P2X3 receptor antagonists have been developed to address this problem. RESEARCH QUESTION: How does the benefit-risk profile vary across the five available P2X3 receptor antagonists? STUDY DESIGN AND METHODS: A systematic review and network meta-analysis was conducted to evaluate the efficacy of P2X3 receptor antagonists, including gefapixant, sivopixant, eliapixant, camlipixant, and filapixant. Primary outcomes were a reduction rate in 24-h cough frequency and incidence of taste disturbance. Dose-response curves and median effective dose (ED50) were calculated. Effect size at ED50 was ranked according to the surface under the cumulative ranking curve. The confidence was evaluated by Confidence In Network Meta-Analysis. RESULTS: Sixteen randomized controlled trials involving 4,904 participants were analyzed. The gefapixant regimen demonstrated an ED50 of 90.7 mg/d for cough frequency reduction. Gefapixant showed the highest antitussive effectiveness at ED50 (reduction rate in 24-h cough frequency: median, 28.1%; 95% credible interval [CrI], 21.0%-35.6%; ranked 1 of 5; moderate certainty) but the highest prevalence of taste disturbance (absolute risk difference per 100 patients: median, 38; 95% CrI, 27-51; ranked 5 of 5; high certainty) and the highest prevalence of discontinuation. Camlipixant had a well-balanced profile (reduction rate in 24-h cough frequency: median, 14.7%; 95% CrI, 5.4%-26.0%; ranked 3 of 5; low certainty; and taste disturbance; absolute risk difference per 100 patients; median, 2; 95% CrI, 1-6; ranked 2 of 5; low certainty). Placebo had a mean of 33.1% reduction in 24-h cough frequency. INTERPRETATION: When used at safe doses, gefapixant had a favorable risk-benefit profile compared with the other four agents. Camlipixant showed initial promise, which may be further investigated by phase III trials currently underway. CLINICAL TRIAL REGISTRATION: UMIN000050622; URL.

Patients with idiopathic pulmonary fibrosis and refractory cough have traction bronchiectasis and distorted airway architecture: a retrospective case review study.

Cough is a common and important sign/symptom in patients with idiopathic pulmonary fibrosis (IPF). However, there have been few reports focusing on cough, and the exact mechanisms for cough in patients with IPF have remained unclear. The objective of this study was to investigate the clinical features of IPF patients with refractory cough and to clarify mechanisms for cough in these patients. We retrospectively reviewed the files of patients with the diagnosis of IPF at Kanazawa University Hospital and compared the clinical features of IPF patients with refractory cough with the clinical features of IPF patients without refractory cough. Among a total of 23 patients with IPF, 10 patients (43.5%) had chronic cough. Of the ten patients, seven patients had concomitant conditions that could lead to cough. Of these seven patients, the cough of four patients was resolved after treatment of their concomitant condition. Finally, among the 23 patients there were 6 (26.1%) with refractory cough associated with IPF. Significant differences were seen between the following clinical features of IPF patients with or without refractory cough, respectively, as follows: lower body mass index (BMI; 18.8±2.5 vs. 22.8±2.5 kg/m2, P<0.01), lower forced vital capacity (FVC; 77.5%±30.4% predicted vs. 99.9%±0.53% predicted, P=0.046), and presence of traction bronchiectasis and distorted airway architecture on high-resolution computed tomography (HRCT; 83.3% vs. 11.8%, P<0.01). The difference between the proportions of patients with or without refractory cough with capsaicin cough sensitivity was not significant. Mechanical stress on the airways due to traction bronchiectasis and distorted airway architecture is a possible mechanism for cough in IPF patients.

Comparing region of interest selection and whole-field analysis for measurement of ciliary beat frequency in high-speed video analysis.

BACKGROUND: Ciliary beat frequency (CBF) is crucial in mucociliary clearance. High-speed video analysis (HSVA) is commonly used to measure CBF but lacks standardization. We compared visual observation and computer-assisted calculation using fast Fourier transformation (FFT) in freshly collected bronchial ciliary epithelial cells and cultured cells. METHODS: Bronchial epithelial cells were obtained from 12 patients who required bronchoscopic examination. Eighty-five videos of ciliary movement of freshly collected and cultured cells were recorded and used to calculate CBF using manual observation, region of interest (ROI) selection, and whole-field analysis. RESULTS: CBF measured by the ROI selection method strongly correlated with that measured using manual observation, especially in freshly collected cells. However, 27.8% of the manual observation method values were doubled in the ROI selection method, probably because a round trip of cilia was calculated as two cycles and needed to be corrected to 1/2 value. Upon increasing the number of ROIs, the results of the ROI selection method came closer to that of WFA. CONCLUSIONS: Computer-assisted calculation using FFT can aid in measuring CBF; however, current methods require visual confirmation. Further automated evaluation techniques are needed to establish more standardized and generalized CBF measurement methods using HSVA.

Prevalence and causes of chronic cough in Japan.

BACKGROUND: Chronic cough is one of the most common symptoms of respiratory diseases and can adversely affect patients' quality of life and interfere with social activities, resulting in a significant social burden. A survey is required to elucidate the frequency and treatment effect of chronic cough. However, clinical studies that cover all of Japan have not yet been conducted. METHODS: Patients who presented with a cough that lasted longer than 8 weeks and visited the respiratory clinics or hospitals affiliated with the Japan Cough Society during the 2-year study period were registered. RESULTS: A total of 379 patients were enrolled, and those who did not meet the definition of chronic cough were excluded. A total of 334 patients were analyzed: 201 patients had a single cause, and 113 patients had two or more causes. The main causative diseases were cough variant asthma in 92 patients, sinobronchial syndrome (SBS) in 36 patients, atopic cough in 31 patients, and gastroesophageal reflux (GER)-associated cough in 10 patients. The time required to treat undiagnosed patients and those with SBS was significantly longer and the treatment success rate for GER-associated cough was considerably poor. CONCLUSIONS: We confirmed that the main causes of chronic cough were cough variant asthma, SBS, atopic cough, and their complications. We also showed that complicated GER-associated cough was more likely to become refractory. This is the first nationwide study in Japan of the causes and treatment effects of chronic cough.

A systematic review and meta-analysis of macrolides in the management of adult patients with asthma.

BACKGROUND: The efficacy of macrolides in the management of asthma has been studied but remains controversial. We conducted a systematic review and meta-analysis of macrolides in the management of adult patients with asthma. METHODS: Randomized controlled trials of macrolides used in adult patients with asthma were searched for in MEDLINE, EMBASE, PsycINFO, Cochrane Library, CINAHL, and Igaku Chuo Zasshi databases to evaluate the efficacy and safety of macrolides. RESULTS: Seventeen reports with macrolide treatment durations ranging from 6 to 48 weeks were included. Macrolides did not reduce exacerbations requiring hospitalization, severe exacerbations, or rescue use of short-acting beta-2 agonist inhalers; improve lung function; decrease peripheral blood or sputum neutrophil counts; or decrease fractional exhaled nitric oxide compared to placebo. Macrolides statistically improved asthma control and quality of life but by less than the minimal clinically important difference. Peripheral blood eosinophil counts as well as serum and sputum eosinophilic cationic protein concentrations were significantly decreased with macrolides compared to placebo. The improvement of asthma symptoms and airway hyperresponsiveness varied by study. The safety profile of macrolides was comparable to that of placebo. CONCLUSIONS: Although macrolides have some useful clinical aspects, there is not sufficient evidence to recommend their use in the management of adult patients with asthma.

Bronchial thermoplasty improves cough hypersensitivity and cough in severe asthmatics.

BACKGROUND: Cough is a troublesome symptom of asthma because it is associated with disease severity and poor asthma control. Bronchial thermoplasty (BT) may be effective in improving cough severity and cough-related quality of life in severe uncontrolled asthma. OBJECTIVE: To evaluate the efficacy of BT for cough in severe uncontrolled asthma. METHODS: Twelve patients with severe uncontrolled asthma were enrolled in this study between 2018 May and March 2021 and arbitrarily divided into cough-predominant [cough severity Visual Analog Scale (VAS) ≥ 40 mm, n = 8] and typical asthma (cough VAS <40 mm, n = 4) groups. Clinical parameters, such as capsaicin cough sensitivity [C-CS: the concentrations to inhaled capsaicin required to induce at least two (C2) and five (C5) coughs], lung function, and type-2-related biomarkers (fractional nitric oxides and absolute eosinophil counts) and cough-related indices [cough severity VAS and the Leicester Cough Questionnaire (LCQ)] were evaluated before and 3 months after performing BT. RESULTS: BT significantly improved both cough-related indices and C-CS in the cough-predominant group. Changes in C-CS were significantly correlated with changes in the LCQ scores (C5: r = 0.65, p = 0.02 for all patients, and r = 0.81, p = 0.01 for the cough-predominant group). CONCLUSIONS: BT may be effective for cough in severe uncontrolled asthma by improving C-CS. However, further larger cohort studies are necessary to confirm the effect of BT for cough in asthma. CLINICAL TRIAL REGISTRATION: This study was registered in the UMIN Clinical Trials Registry (Registry ID UMIN: 000031982).

Bronchial Thermoplasty Attenuates Cough Reflex Sensitivity in Severe Asthma : A Single-Center Retrospective Study with 2-year Follow-up.

Despite the relatively short follow-up period in our previous study, we had reported that increased cough reflex sensitivity (CRS) may predict the efficacy of bronchial thermoplasty (BT) for treating asthma. Herein, we examined whether CRS predicts the efficacy of BT 2 years after the final BT treatment. We also investigated the influence of BT on CRS. We reviewed 10 patients 2 years after their final BT treatment. CRS, asthma-related symptoms, asthma exacerbations, and cough-related quality of life were assessed at baseline and 2 years after BT. Five patients responded positively to BT (BT responders) and their asthma control improved. No significant difference in CRS at baseline was detected between the BT responders and nonresponders. In contrast, BT responders exhibited significant improvements in CRS 2 years after BT. CRS at baseline could not predict the BT efficacy after 2 years. This is the first report demonstrating BT desensitized CRS in consecutive case series. J. Med. Invest. 70 : 271-275, February, 2023.

Real-world efficacy of anti-IL-5 treatment in patients with allergic bronchopulmonary aspergillosis.

Despite standard treatment with systemic corticosteroids and/or antifungal triazoles, a substantial proportion of patients with allergic bronchopulmonary aspergillosis (ABPA) experience frequent relapses and require long-term treatment despite unfavorable adverse effects. We investigated the efficacy and safety of anti-interleukin (IL)-5/IL-5 receptor α chain (Rα) monoclonal antibodies (mAbs) in patients with ABPA complicated by asthma. ABPA cases treated with anti-IL-5/IL-5Rα mAbs were collected from 132 medical institutes in 2018 and published case reports in Japan. Clinical outcomes, laboratory and physiological data, and radiographic findings during 32 weeks before and after treatment were retrospectively evaluated. We analyzed 29 cases of ABPA: 20 treated with mepolizumab and nine with benralizumab. Treatment with anti-IL-5/IL-5Rα mAbs reduced the frequency of exacerbations (p = 0.03), decreased the dose of oral corticosteroids (p < 0.01), and improved pulmonary function (p = 0.01). Mucus plugs in the bronchi shrank or diminished in 18 patients (82%). Despite the clinical/radiographical improvement, serum levels of total IgE, the key biomarker for the pharmacological response in ABPA, were unchanged. Anti-IL-5/IL-5Rα mAbs that directly target eosinophils are promising candidates for the treatment of patients with ABPA, especially those with mucus plugs in the bronchi.

Primary ciliary dyskinesia with CCDC39 variants displaying specific ciliary ultrastructure and movement concordant with the genotype: A case report.

Primary ciliary dyskinesia (PCD) is a genetic disease with chronic airway infection and inflammation caused by ciliary ultrastructural defects and impairment in ciliary function. We present an adult case of PCD with compound heterozygous nonsense variants in CCDC39. The ciliary ultrastructure findings using electron microscopy and ciliary movement using high-speed video analysis matched the genotype. This is the first case report of PCD with CCDC39 variants in Japan demonstrating specific ciliary ultrastructure and movement related to the genotype.

Tiotropium Add-On and Treatable Traits in Asthma-COPD Overlap: A Real-World Pilot Study.

Purpose: The 'treatable traits' strategy for patients with chronic inflammatory airway diseases, especially asthma and chronic obstructive pulmonary disease (COPD), is a focus of interest, because it implements precision and personalized medicine. Asthma-COPD overlap (ACO), a phenotype involving both asthma and COPD, is an important disease entity because patients with ACO have significantly worse outcomes, conferring greater economical and social burdens. Some guidelines for ACO recommend add-on therapy of long-acting muscarinic antagonists to inhaled corticosteroids and long-acting ß2 agonists. However, this approach is based on extrapolation from patients with asthma or COPD alone. Consequently, a 'treatable traits' approach suitable for ACO remains obscure. Methods: A 12-week open-label cross-over pilot study was conducted in patients with ACO to investigate the effect of tiotropium bromide (TIO) 5 µg/day add-on therapy to fluticasone propionate/formoterol fumarate (FP/FM) 500/20 µg/day compared with FP/FM 500/20 µg/day alone. A 4-week run-in period and two 4-week treatment periods were included. Results: A total of 18 male patients with stable ACO participated in this pilot study. All patients were ex-smokers. Mean values ± standard deviation (SD) for forced expiratory volume in 1 second (FEV1) were 1.21 ± 0.49 L after the run-in period, 1.20 ± 0.51 L after the FP/FM combination therapy period, and 1.30 ± 0.48 L after the TIO add-on therapy to FP/FM period. FEV1 values after the TIO add-on therapy FP/FM period were significantly higher than those after the run-in period (p < 0.01). Conclusion: TIO add-on therapy to FP/FM in patients with ACO, considered difficult to treat because of the presence of both asthma and COPD, resulted in improvements in lung function parameters in this real-world pilot study, indicating the potential value of TIO add-on therapy as a "treatable traits" option for standard treatment for ACO.

Fractional analysis of bronchoalveolar lavage in systemic sclerosis-associated interstitial lung disease.

BACKGROUND: The utility of bronchoalveolar lavage (BAL) in the evaluation of systemic sclerosis-associated interstitial lung disease (SSc-ILD) remains controversial. Fractional analysis of BAL (FBAL) is a technique that can analyze small airways and alveolar compartments separately and has proven informative in other ILDs. The aim of this study was to explore FBAL characteristics across the spectrum of SSc-ILD severity. METHODS: We retrospectively reviewed patients with SSc-ILD who underwent bronchoscopy with FBAL using three 50 mL aliquots of saline solution. These aliquots were analyzed separately for differential cell composition (FBAL-1, -2, and -3). We compared the FBAL cell composition to the progression of ILD and end-stages of ILD using Cox proportional hazards models. RESULTS: Sixty-eight patients with SSc-ILD were enrolled in this study. The percentage of neutrophils and eosinophils was lower in FBAL-3 compared to FBAL-1. In contrast, the percentage of macrophages and lymphocytes was higher in FBAL-3. Neutrophils in FBAL-2, -3, and the estimated total FBAL cell fraction (FBAL-total) were negatively correlated with the forced vital capacity % predicted (r=-0.420, -0.362, -0.409, respectively). Although FBAL-total was not linked to the progression and end-stage of ILD, a high percentage of neutrophils in FBAL-3 was significantly associated with the development of end-stage ILD (HR 1.093, 95% CI: 1.003-1.190). CONCLUSIONS: A higher percentage of neutrophils in FBAL-3 is correlated with development of end-stage ILD in SSc-ILD as well as mortality.

Two cases of chronic obstructive pulmonary disease evaluated by dynamic-ventilatory digital radiography for pulmonary function and assessment of treatment efficacy.

Spirometry is a crucial test used in the diagnosis and monitoring of patients with chronic obstructive pulmonary disease (COPD). Severe acute respiratory syndrome coronavirus 2 pandemic has posed numerous challenges in performing spirometry. Dynamic-ventilatory digital radiography (DR) provides sequential chest radiography images during respiration with lower doses of radiation than conventional X-ray fluoroscopy and computed tomography. Recent studies revealed that parameters obtained from dynamic DR are promising for evaluating pulmonary function of COPD patients. We report two cases of COPD evaluated by dynamic-ventilatory DR for pulmonary function and treatment efficacy and discuss the potential of dynamic DR for evaluating COPD therapy.

Chest Dynamic-Ventilatory Digital Radiography in Chronic Obstructive or Restrictive Lung Disease.

OBJECTIVE: The aim of this study was to identify the relationships between parameters obtained from dynamic-ventilatory digital radiography (DR) and ventilatory disorders. METHODS: This study comprised 273 participants with respiratory diseases who underwent spirometry and functional residual capacity measurements (104 with normal findings on spirometry as controls, 139 with an obstructive lung disorder, 30 with a restrictive lung disorder) were assessed by dynamic-ventilatory DR. Sequential chest radiography images of the patient's slow and maximum breathing were captured at 15 frames per second by a dynamic flat-panel imaging system. The system measured the following parameters: lung area at maximum inspiration divided by height (lung area_in/height), changes in tracheal diameter due to respiratory motions, rate of tracheal narrowing, diaphragmatic motion, and rate of change in lung area due to respiratory motion. Relationships between these parameters and ventilatory disorders were analyzed. RESULTS: Lung area_in/height in patients with restrictive disorders showed significant decreases. Tracheal diameter change and tracheal narrowing rate in patients with obstructive disorders were significantly increased compared to both the control participants and patients with restrictive disorders. Patients with obstructive disorders and patients with restrictive disorders showed decreased diaphragmatic motion and lung area change rate. With the restrictive disorders as references, the area under the curve (AUC), sensitivity and specificity of lung area_in/height were 0.88, 0.77, and 0.88, respectively. With the obstructive disorders as references, the AUC, sensitivity and specificity of tracheal narrowing rate were 0.67, 0.53 and 0.81, respectively. CONCLUSION: Dynamic-ventilatory DR shows potential as a method for the detection and evaluation of ventilatory disorders in patients with respiratory diseases.

Late-onset programmed cell death protein-1 inhibitor-induced pneumonitis after cessation of nivolumab or pembrolizumab in patients with advanced non-small cell lung cancer: a case series.

Awareness of the immune-related adverse event of programmed cell death protein-1 (PD-1) inhibitor-induced pneumonitis is important. Herein, we report the clinical course of 3 patients suspected to have PD-1 inhibitor-induced pneumonitis after cessation of PD-1 inhibitor treatment. In case 1, a 62-year-old man was diagnosed with stage IVA adenocarcinoma. Nivolumab monotherapy was prescribed as second-line therapy and later discontinued due to financial reasons. Seven months after the final administration of nivolumab, the patient developed what we diagnosed as nivolumab-induced pneumonitis. The patient was immediately prescribed prednisolone (1 mg/kg p.o. daily), and the pneumonitis resolved after 1.5 months. In case 2, a 68-year-old man was diagnosed with stage IVB squamous cell carcinoma. Nivolumab monotherapy was prescribed as fourth-line therapy. After the second administration of nivolumab, the patient developed what we diagnosed as nivolumab-induced pneumonitis; nivolumab was discontinued, and the patient was immediately prescribed prednisolone (1 mg/kg p.o. daily). Eight months after the final administration of nivolumab, the patient again developed nivolumab-induced pneumonitis. The pneumonitis resolved without additional medication. In case 3, a 69-year-old man was diagnosed with stage IVB adenocarcinoma. Pembrolizumab monotherapy was initiated as sixth-line therapy, and it was discontinued after 4 cycles due to disease progression. Four months after the final dose of pembrolizumab, the patient developed what we diagnosed as pembrolizumab-induced pneumonitis. The patient immediately received a high intravenous dose of methylprednisolone (1,000 mg per day for three days). The pneumonitis and respiratory failure progressed, and he died 8 weeks after the onset of the pneumonitis. We report pneumonitis after discontinuation of ICIs in 3 patients. We confirm that, although uncommon, PD-1 inhibitor-induced irAEs can develop after treatment discontinuation. Further accumulation of cases and clarification of the clinical features of patients with irAEs, such as the time of onset, imaging findings, and treatment outcomes are needed.

Molecular features of tumor-derived genetic alterations in circulating cell-free DNA in virtue of autopsy analysis.

In cancer patients, circulating cell-free DNA (cfDNA) includes tumor-derived DNA (tDNA). cfDNA has been used clinically for non-invasive gene mutation testing. The aim of this study was to characterize the features of the genetic alterations detected in cfDNA. This study included 6 patients with primary lung cancer who died due to cancer progression. Tumors were biopsied at autopsy. Genetic alteration profiles were obtained using next generation sequencing. The features of the tDNA genetic alterations detected in cfDNA included a higher frequency of being present in multiple tumors (67% truncal mutations, 36% shared mutations, and 4% individual mutations) and a higher variant allele frequency (VAF; 47.6% versus 4.1% for tDNA alterations detected in cfDNA versus not detected in cfDNA, respectively). The data revealed that the tumor-derived genetic alterations most easily detected in cfDNA were truncal mutations with a high VAF. These results showed that essential genetic alterations enriched in cfDNA could help to characterize cancer cells and that genetic testing using cfDNA has advantages in the detection of fundamental regulatory aberrations occurring during tumorigenesis.

Case report: Migraine that persisted for over 20 years disappears after treatment for pulmonary arteriovenous fistula.

We presented a rare case of pulmonary arteriovenous fistula in a patient who suffered from migraine with optic aura for longer than 20 years. This case suggests that the migraine could be expected to disappear after treatment for pulmonary arteriovenous fistula.

Methacholine-induced cough as an indicator of bronchodilator-responsive cough.

BACKGROUND: Cough variant asthma (CVA) is the most common cause of chronic cough and responds well to bronchodilator therapy. Previous studies on methacholine -induced cough have shown that heightened cough response due to bronchoconstriction is a feature of CVA. The aim of this study was to assess Mch-induced cough as an indicator of bronchodilator-responsive cough (BRC). METHODS: This was a single-center retrospective study of prolonged/chronic cough cases who underwent evaluation via spirometry, FeNO and bronchial challenge testing using Mch and capsaicin (C5). Resultant bronchoconstriction after Mch challenge was assessed by flow-volume curves measuring the expiratory flow of the partial flow-volume curve 40% above residual volume (PEF40) and FEV1. BRC was defined as a decrease in cough with bronchodilator therapy by 30% or more on a visual analog scoring scale. RESULTS: Of the 100 patients evaluated, 63 were diagnosed with BRC. Mch-induced cough at a decrease in PEF40 of 35% (PC35-PEF40) was predictive of BRC on AUROC analysis with an AUC of 0.82 (95% CI 0.73-0.90) and cut-off of 24. The AUC for C5, FeNO and PC20-FEV1 were 0.65, 0.47, and 0.58, respectively. CONCLUSION: Compared to C5, FeNO and PC20-FEV1, Mch-induced cough better supports a diagnosis of BRC.

Dynamic-Ventilatory Digital Radiography in Air Flow Limitation: A Change in Lung Area Reflects Air Trapping.

OBJECTIVE: The aim of this study was to determine the utility of dynamic-ventilatory digital radiography (DR) for pulmonary function assessment in patients with airflow limitation. METHODS: One hundred and eighteen patients with airflow limitation (72 patients with lung cancer before surgery, 35 patients with chronic obstructive pulmonary disease [COPD], 6 patients with asthma, and 5 patients with asthma-COPD overlap syndrome) were assessed with dynamic-ventilatory DR. The patients were instructed to inhale and exhale slowly and maximally. Sequential chest X-ray images were captured in 15 frames per second using a dynamic flat-panel imaging system. The relationship between the lung area and the rate of change in the lung area due to respiratory motion with respect to pulmonary function was analyzed. RESULTS: The rate of change in the lung area from maximum inspiration to maximum expiration (Rs ratio) was associated with the RV/TLC ratio (r = 0.48, p < 0.01) and the percentage of the predicted FEV1 (r = -0.33, p < 0.01) in patients with airflow limitations. The Rs ratio also decreased in an FEV1-dependent manner. CONCLUSION: The rate of change in the lung area due to respiratory motion evaluated with dynamic DR reflects air trapping. Dynamic DR is a potential tool for the comprehensive assessment of pulmonary function in patients with COPD.