Influence of Diaphragmatic Mobility on Hypercapnia in Patients with Chronic Obstructive Pulmonary Disease

A reduction in diaphragm mobility has been identified in patients with chronic obstructive pulmonary disease (COPD) and has been associated with a decline in pulmonary function parameters. However, little information exists regarding the potential role of diaphragm mobility on hypercapnia in COPD. A new method of assessing the mobility of the diaphragm, using ultrasound, has recently been validated. The purpose of the present study was to investigate the relationship between diaphragm mobility and pulmonary function parameters, as well as that between arterial blood gas values and diaphragm mobility, in COPD patients. Thirty seven COPD patients were recruited for pulmonary function test, arterial blood gas analysis and diaphragm mobility using ultrasound to measure the craniocaudal displacement of the left branch of the portal vein. There were significant negative correlations between diaphragmatic mobility and PaCO2 (r = -0.373, P = 0.030). Diaphragmatic mobility correlated with airway obstruction (FEV1, r = 0.415, P = 0.011) and with ventilatory capacity (FVC, r = 0.302, P = 0.029; MVV, r = 0.481, P = 0.003). Diaphragmatic mobility also correlated significantly with pulmonary hyperinflation. No relationship was observed between diaphragm mobility and PaO2 (r = -0.028, P = 0.873). These findings support a possibility that the reduction in diaphragm mobility relates to hypercapnia in COPD patients

The Hyper Suprime-Cam SSP survey: Overview and survey design

Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2-m Subaru telescope on the summit of Mauna Kea in Hawaii. A team of scientists from Japan, Taiwan, and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400 deg2 in five broad bands (grizy), with a 5 σ point-source depth of r ≈ 26. The Deep layer covers a total of 26 deg2 in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter still in two pointings of HSC (a total of 3.5 deg2). Here we describe the instrument, the science goals of the survey, and the survey strategy and data processing. This paper serves as an introduction to a special issue of the Publications of the Astronomical Society of Japan, which includes a large number of technical and scientific papers describing results from the early phases of this survey

Detection of the usual interstitial pneumonia pattern in chest CT: effect of computer-aided diagnosis on radiologist diagnostic performance

BackgroundAnti-fibrotic drugs for interstitial pulmonary fibrosis (IPF) have been developed. Physicians are becoming increasingly aware of the need for better diagnosis of IPF.PurposeTo evaluate whether a computer-aided system can improve the diagnostic performance of general radiologists in detecting the usual interstitial pneumonia (UIP) pattern on computed tomography (CT).Material and MethodsWe included 60 CT datasets from 30 patients with IPF and 30 with idiopathic fibrosing non-specific interstitial pneumonia (fNSIP), all diagnosed by a multidisciplinary diagnosis (MDD) procedure that included surgical biopsy. We analyzed the CT data using a computer-aided system (Gaussian histogram normalized correlation: GHNC). Five general radiologists with <6 years of experience each interpreted these CT scans with and without the GHNC results. We compared the likelihoods of a UIP-pattern diagnosis with the likelihood of the same diagnosis by MDD using the average area under the curve (AUC) of the receiver operating characteristics (ROC). We also evaluated the association between the radiologists’ diagnosis and survival using the Kaplan–Meier method.ResultsIn the ROC analysis, the AUC increased significantly from 0.731 without GHNC to 0.829 with GHNC (P = 0.0396). The diagnosis without GHNC was not significantly associated with survival for any radiologist, but the UIP diagnosis with GHNC was significantly associated with a worse prognosis for four out of five radiologists.ConclusionThe computer-aided system could increase the confidence level of UIP-pattern diagnosis by non-expert radiologists

Quantitative Analysis for Lung Disease on Thin-Section CT

Thin-section computed tomography (CT) is widely employed not only for assessing morphology but also for evaluating respiratory function. Three-dimensional images obtained from thin-section CT provide precise measurements of lung, airway, and vessel volumes. These volumetric indices are correlated with traditional pulmonary function tests (PFT). CT also generates lung histograms. The volume ratio of areas with low and high attenuation correlates with PFT results. These quantitative image analyses have been utilized to investigate the early stages and disease progression of diffuse lung diseases, leading to the development of novel concepts such as pre-chronic obstructive pulmonary disease (pre-COPD) and interstitial lung abnormalities. Quantitative analysis proved particularly valuable during the COVID-19 pandemic when clinical evaluations were limited. In this review, we introduce CT analysis methods and explore their clinical applications in the context of various lung diseases. We also highlight technological advances, including images with matrices of 1024 × 1024 and slice thicknesses of 0.25 mm, which enhance the accuracy of these analyses

Reproducibility of pulmonary blood flow measurements by phase-contrast MRI using different 1.5 T MR scanners at two institutions

Background Magnetic resonance imaging (MRI) can be beneficial for diagnosis of disease by offering quantitative information. However, reproducibility can be a major problem when there is a numerical threshold in multi-institution, multi-vendor situations. Purpose To measure pulmonary blood flow with phase-contrast (PC) imaging using two different MR scanners (1.5 T) at different institutions in the same participants and to examine the reproducibility of the measurements. Material and Methods Participants were 10 healthy volunteers (5 men; age range, 27–36 years). The measurements included the mean and maximal blood velocities, the mean blood flow volume, and the acceleration time and volume (AT and AV), derived from the time-flow curve of the PC-MRI. Simultaneously obtained maximal, minimal, and mean areas from regions of interest set in the pulmonary artery were also calculated. In order to calculate the reproducibility of the quantitative variables, intra-class correlation coefficients (ICCs) were employed. When an adequate ICC was obtained, Bland–Altman analysis was conducted to identify any systematic bias. Results The ICCs were almost perfect for the mean blood flow volume and the AV (r = 0.82 and 0.80), and were substantial in the mean and maximal areas, and the AT (r = 0.63, 0.74, and 0.64, respectively). However, there was a fixed bias in the area measurement between the two scanners. Also, the AV had a proportional bias. Conclusion Our results reveal that various indices derived from PC-MRI on different MR scanners are promising as common indices for pulmonary flow assessment. Research and clinical use of PC-MRI for the pulmonary artery is expected to extend to multi-institution situations

Comparison of Clinical Characteristics and Outcomes between Idiopathic and Secondary Pleuroparenchymal Fibroelastosis

Background: Pleuroparenchymal fibroelastosis (PPFE) is a unique clinical, radiologic, and histopathologic entity for which several potential etiologies have been reported recently. However, there has been no comprehensive study of secondary PPFE. Objective: Assessment of the clinical characteristics, outcomes, and prognostic factors of secondary and idiopathic PPFE. Methods: We retrospectively reviewed the medical records of consecutive PPFE patients between January 1999 and December 2018. We identified 132 idiopathic PPFE patients and 32 secondary PPFE patients. Results: The incidence of interstitial lung disease (ILD) pattern different from the usual interstitial pneumonia (UIP) pattern in the lower lobes was higher in secondary PPFE patients (38.5%) than in idiopathic PPFE patients (61.5%, p = 0.02). The idiopathic and secondary PPFE groups did not differ significantly in terms of laboratory data, respiratory complications, and survival (median: 5.0 years vs. 4.1 years, p = 0.95). The presence of UIP pattern was independently associated with increased mortality in multivariate analyses in idiopathic PPFE patients, but not in secondary PPFE patients. Conclusions: The frequency and prognostic impact of UIP-pattern ILD differed between idiopathic and secondary PPFE patients. Lung transplantation should be considered in secondary PPFE patients with low diffusing capacity of the lungs for carbon monoxide (DLCO) regardless of lower-lobe ILD pattern