It was hypothesised that the recruitment of atelectatic lung areas is signified by changes in the airway and tissue mechanics, and by the appearance of crackle activity attributed to the sudden reopening of collapsed airways. The authors also assumed that the acoustic activity is an earlier indicator of lung recruitment than the change in the overall mechanical state of the lungs.Six thoracotomised and mechanically ventilated mini-pigs were studied. Low-frequency pulmonary impedance was measured at end-expiratory pauses at transpulmonary pressures of 4 and 1 hPa to estimate airway resistance (R_aw) and the coefficient of lung tissue elastance (H), and tracheal sounds were recorded during subsequent slow inflations to 30 hPa, in the control state and following increasing doses ofi.v.methacholine (Mch).R_awandHwere higher at baseline and increased more in response to Mch at 1 hPa than at 4 hPa. The crackles detected during the subsequent inflations were concentrated around and associated with the development of the lower knee of the pressure–volume curve. The number of crackles increased faster following the Mch doses and reached statistical significance earlier thanR_awandH.Crackle recording during mechanical ventilation can be employed as a simple method with which to monitor lung recruitment–derecruitment.

The aim of this study was to evaluate airway structure-function relations in elastase-induced emphysema in rats. Sprague-Dawley rats were treated intratracheally with 50 IU porcine pancreatic elastase (PPE, n = 8) or saline (controls, n = 6). Six weeks later, lung volumes [functional residual capacity (FRC), residual volume (RV), and total lung capacity (TLC)] and low-frequency impedance parameters (Newtonian resistance, R_N; tissue damping; tissue elastance, H) were measured, and tracheal sounds were recorded during slow inflation to TLC following in vivo degassing. The lungs were fixed and stained for standard morphometry, elastin, and collagen. In the PPE group, FRC and RV were higher [4.53 ± 0.7 (SD) vs. 3.28 ± 0.45 ml; P = 0.003 and 1.06 ± 0.35 vs. 0.69 ± 0.18 ml; P = 0.036, respectively], and H was smaller in the PPE-treated rats than in the controls (1,344 ± 216 vs. 2,178 ± 305 cmH₂O/l; P < 0.001), whereas there was no difference in R_N. The average number of crackles per inflation was similar in the two groups; however, the crackle size distributions were different and the lower knee of the pressure-volume curves was higher in the PPE group. Microscopic images revealed different alveolar size distributions but similar bronchial diameters in the two groups. The treatment caused a slight but significant decrease in the numbers of alveolar attachments, no difference in elastin and slightly increased mean level and heterogeneity of collagen in the bronchial walls. These results suggest that tissue destruction did not affect the conventionally assessed airway resistance in this emphysema model, whereas the alterations in the recruitment dynamics can be an early manifestation of impaired airway function.

Deep-inspirational breath hold (DIBH) is an option for heart protection in breast radiotherapy; we intended to study its individual benefit. 3DCRT treatment planning was performed in a cohort of 103 patients receiving radiotherapy of the whole breast (WBI)/chest wall (CWI) ± nodal regions (NI) both under DIBH and free breathing (FB) in the supine position, and in the WBI only cases prone (n = 45) position, too. A series of patient-related and heart dosimetry parameters were analyzed. The DIBH technique provided dramatic reduction of all heart dosimetry parameters the individual benefit, however, varied. In the whole population the best predictor of benefit was the ratio of ipsilateral lung volume (ILV)FB and ILVDIBH. In the WBI cohort 9–11 patients and 5–8 patients received less dose to selected heart structures with the DIBH and prone positioning, respectively; based on meeting various dose constraints DIBH was the only solution in 6–13 cases, and prone positioning in 5–6 cases. In addition to other excellent predictors, a small ILVFB or ILVDIBH with outstanding predicting performance (AUC ≥ 0.90) suggested prone positioning. Detailed analysis consistently indicated the outstanding performance of ILVFB and ILVDIBH in predicting the benefit of one over the other technique in lowering the mean heart dose (MHD), left anterior descending coronary artery (LAD) mean dose and left ventricle(LV)-V5Gy. The preference of prone positioning was further confirmed by anatomical parameters measured on a single CT scan at the middle of the heart. Performing spirometry in a cohort of 12 patients, vital capacity showed the strongest correlation with ILVFB and ILVDIBH hence this test could be evaluated as a clinical tool for patient selection. Individual lung volume measures estimated by spirometry and anatomical data examined prior to acquiring planning CT may support the preference of DIBH or prone radiotherapy for optimal heart protection.

Alzheimer’s disease (AD) involves the accumulation of amyloid-β (Aβ) plaques, whose quantification plays a central role in understanding disease progression. Automated segmentation of Aβ deposits in histopathological micrographs enables large-scale analyses but is hindered by the high cost of detailed pixel-level annotations. Weakly supervised learning offers a promising alternative by leveraging coarse or indirect labels to reduce the annotation burden. We evaluated a weakly supervised approach to segment and analyze thioflavin-S-positive parenchymal amyloid pathology in AD and age-matched brains. Our pipeline integrates three key components, each designed to operate under weak supervision. First, robust preprocessing (including retrospective multi-image illumination correction and gradient-based background estimation) was applied to enhance image fidelity and support training, as models rely more on image features. Second, class activation maps (CAMs), generated by a compact deep classifier SqueezeNet, were used to identify, and coarsely localize amyloid-rich parenchymal regions from patch-wise image labels, serving as spatial priors for subsequent refinement without requiring dense pixel-level annotations. Third, a patch-based convolutional neural network, U-Net, was trained on synthetic data generated from micrographs based on CAM-derived pseudo-labels via an extensive object-level augmentation strategy, enabling refined whole-image semantic segmentation and generalization across diverse spatial configurations. To ensure robustness and unbiased evaluation, we assessed the segmentation performance of the entire framework using patient-wise group k-fold cross-validation, explicitly modeling generalization across unseen individuals, critical in clinical scenarios. Despite relying on weak labels, the integrated pipeline achieved strong segmentation performance with an average Dice similarity coefficient (≈0.763) and Jaccard index (≈0.639), widely accepted metrics for assessing segmentation quality in medical image analysis. The resulting segmentations were also visually coherent, demonstrating that weakly supervised segmentation is a viable alternative in histopathology, where acquiring dense annotations is prohibitively labor-intensive and time-consuming. Subsequent morphometric analyses on automatically segmented Aβ deposits revealed size-, structural complexity-, and global geometry-related differences across brain regions and cognitive status. These findings confirm that deposit architecture exhibits region-specific patterns and reflects underlying neurodegenerative processes, thereby highlighting the biological relevance and practical applicability of the proposed image-processing pipeline for morphometric analysis.

Auscultation on the chest has long been considered a valuable part of the physical examination. The analysis of acoustic signals accompanying is non-invasively suitable to assess respiratory and cardiac function. However, the diagnosis based on auscultation maybe subjective and biased by human factors. We aimed at extending the auscultation technic by telemedicine and artificial intelligence tools to minimize the subjective factors present in the traditional evaluation of lung sounds. Teleauscultation was performed on hospitalised or outpatient care children aged 3 months to 10 years with diagnosed acute bronchiolitis (n=9), asthma (n=5), obstructive bronchitis (n=4), chronic bronchitis (n=3) and other lung diseases (n=10) by using electronic stethoscope (3M Littmann Model 3200) controlled by self-developed smartphone application. The registered sound files were uploaded to a clinical cloud storage that can be accessed only by the participating paediatric pulmonologists for further evaluations. This web based system allows the annotation of the acoustic events such as wheezes, stridors, crackles and other disease-specific lung sounds. Altogether 340 characteristic sounds were identified from the 192 recordings, with number of rhonchi, wheezes, stridors and other lung sound events of 140, 25, 40 and 135, respectively. This teleauscultation system is suitable for replaying and systematic re-evaluation of the sound files, which has importance in more detailed further analyses and in medical education. Applying intelligent learning algorithms to the archived and structured acoustic database has the promise to contribute to the more objective interpretation of lung sounds. Grant: EFOP-3.6.1-16-2016-00008

Childhood asthma poses an increasing health care and financial burden, with costs mainly originate from personal clinical assessments and from hospitalizations due to exacerbation. Home spirometry may be suitable for early detection of lung function deterioration and thus, it may assist early therapeutic interventions to reduce the risk of exacerbation. Spirometry currently requires personal patient-physician contact, but rapid development of telemedicine devices facilitates remote spirometry. We aimed at investigating the suitability of portable spirometers allowing telemedical assessment of lung function. We also examined whether regular home measurements can also follow daily variations in the airway caliber within patients. We first compared respiratory function parameters measured with a mobile and a clinically approved spirometer in a group of outpatient care children diagnosed with asthma (n=16, 13±3.4 yrs). A subgroup of 4 children was randomly selected to use telespirometry and was instructed to measure their lung function twice a day according to the ATS/ERS guidelines. In the validation study of clinical and mobile spirometers, we found good agreement in the respiratory function parameters examined. No significant daily variations in PEF (p=0.30) and FEF25-75 (p=0.79) were observed, whereas a tendency in FEV1 (p=0.06) and FVC (p=0.09) for morning elevations appeared. These results suggest that telespirometry system is suitable for telemonitoring of asthmatic children, it can support asthma management and predict exacerbations. While further research is required to confirm the observed trends, the benefit of remote lung function assessment may have particular value in the COVID-19 era.