Alveolar Size Research Articles

Dental morphology evolution in early peratheriines, including a new morphologically cryptic species and findings on the largest early Eocene European metatherian

ABSTRACT The initial stages of the evolutionary history of peratheriines, the European herpetotheriid metatherians, are largely unknown, primarily due to their limited morphological dental disparity throughout the Palaeogene, coupled with significant intraspecific variation. Based on eleven molars, we document a new early peratheriine species, Peratherium musivum sp. nov. which is larger than and morphologically similar to the earliest peratheriine, Peratherium constans (MP7). Subtle molar characters are shared with the largest early Eocene peratheriine, Peratherium maximum comb. nov. We illustrate the importance of studying possible changes in molar cusp – basin proportions and correlated characters that occured during peratheriine evolution. Peratherium musivum sp. nov. which spanned only part of the MP7-MP8 + 9 time interval, and the ~MP8 + 9 Peratherium maximum comb. nov. were probably widespread in Western Europe. The description of a well-preserved mandible of the latter, from La Borie (~MP8 + 9), reveals original features concerning relative size and shape of dental alveoli, partly corroborated using isolated molars. These traits are absent in the younger, most representative species of both peratheriine genera, Peratherium and Amphiperatherium. Based on the aforementioned data and a critical review, it is demonstrated that peratheriine genera lack consistent definitions, so that the Peratherium/Amphiperatherium dichotomy is plausibly inapplicable to early Eocene representatives. This article is registered in ZooBank under urn:lsid:zoobank.org:pub:A2B4DE58-855C-4CB8-BC1D-C9677E6DF97D

Healing of Extraction Sites after Alveolar Ridge Preservation Using Advanced Platelet-Rich Fibrin: A Retrospective Study.

Over time, numerous surgical procedures and biomaterials have been proposed for the reconstruction of post-extraction bone defects, each with their advantages and disadvantages. The main objective of this study was to evaluate dimensional changes in the alveolar bone 3 months after tooth extraction, before implant planning, comparing alveolar ridge preservation (ARP) with spontaneous healing. A total of 84 patients with non-restorable molars were included in the study. Forty-two patients received ARP with advanced platelet-rich fibrin (A-PRF) and spontaneous healing was evaluated in these patients. Cone beam computed tomography (CBCT) analysis performed before and after surgical intervention was used to determine the changes in vertical and horizontal bone dimensions produced after tooth extraction. CBCT measurements showed reduction in both vertical and horizontal alveolar bone size in both groups. For the study group, the alveolar parameters (height, width) were higher compared to the control group. The percentage variations between dimensional differences from the two groups were 38.58% for height, and for width were 36.88% at 0 mm, 35.56% at 3 mm, 36.61% at 5 mm, and 38.73% at 7 mm. The differences were statistically significant (p ˂ 0.0005). The results obtained after ARP with A-PRF showed a reduced loss of bone volume compared to spontaneous healing.

PC (16:0/14:0) ameliorates hyperoxia-induced bronchopulmonary dysplasia by upregulating claudin-1 and promoting alveolar type II cell repair

Bronchopulmonary dysplasia (BPD) remains a significant challenge in neonatal care, the pathogenesis of which potentially involves altered lipid metabolism. Given the critical role of lipids in lung development and the injury response, we hypothesized that specific lipid species could serve as therapeutic agents in BPD. This study aimed to investigate the role of the lipid Phosphatidylcholine (PC) (16:0/14:0) in modulating BPD pathology and to elucidate its underlying mechanisms of action. Our approach integrated in vitro and in vivo methodologies to assess the effects of PC (16:0/14:0) on the histopathology, cellular proliferation, apoptosis, and molecular markers in lung tissue. In a hyperoxia-induced BPD rat model, we observed a reduction in alveolar number and an enlargement in alveolar size, which were ameliorated by PC (16:0/14:0) treatment. Correspondingly, in BPD cell models, PC (16:0/14:0) intervention led to increased cell viability, enhanced proliferation, reduced apoptosis, and elevated surfactant protein C (SPC) expression. RNA sequencing revealed significant gene expression differences between BPD and PC (16:0/14:0) treated groups, with a particular focus on Cldn1 (encoding claudin 1), which was significantly enriched in our analysis. Our findings suggest that PC (16:0/14:0) might protect against hyperoxia-induced alveolar type II cell damage by upregulating CLDN1 expression, potentially serving as a novel therapeutic target for BPD. This study not only advances our understanding of the role of lipids in BPD pathogenesis, but also highlights the significance of PC (16:0/14:0) in the prevention and treatment of BPD, offering new avenues for future research and therapeutic development.

Effect of estrogen receptor α on cardiopulmonary adaptation to chronic developmental hypoxia in a rat model.

Humans living at high-altitude (HA) have adapted to this environment by increasing pulmonary vascular and alveolar growth. RNA sequencing data from a novel murine model that mimics this phenotypical response to HA suggested estrogen signaling via estrogen receptor alpha (ERα) may be involved in this adaptation. We hypothesized ERα was a key mediator in the cardiopulmonary adaptation to chronic hypoxia and sought to delineate the mechanistic role ERα contributes to this process by exposing novel loss-of-function ERα mutant (ERαMut) rats to simulated HA. ERα mutant or wild-type (wt) rats were exposed to normoxia or hypoxia starting at conception and continued postnatally until 6 wk of age. Both wt and ERαMut animals born and raised in hypoxia exhibited lower body mass and higher hematocrits, total alveolar volumes (Va), diffusion capacities of carbon monoxide (DLCO), pulmonary arteriole (PA) wall thickness, and Fulton indices than normoxia animals. Right ventricle adaptation was maintained in the setting of hypoxia. Although no major physiologic differences were seen between wt and ERαMut animals at either exposure, ERαMut animals exhibited smaller mean linear intercepts (MLI) and increased PA total and lumen areas. Hypoxia exposure or ERα loss-of-function did not affect lung mRNA abundance of vascular endothelial growth factor, angiopoietin 2, or apelin. Sexual dimorphisms were noted in PA wall thickness and PA lumen area in ERαMut rats. In summary, in room air-exposed rats and rats with peri- and postnatal hypoxia exposure, ERα loss-of-function was associated with decreased alveolar size (primarily driven by hypoxic animals) and increased PA remodeling.NEW & NOTEWORTHY By exposing novel loss-of-function estrogen receptor alpha (Erα) mutant rats to a novel model of human high-altitude exposure, we demonstrate that ERα has subtle but inconsistent effects on endpoints relevant to cardiopulmonary adaptation to chronic hypoxia. Given that we observed some histologic, sex, and genotype differences, further research into cell-specific effects of ERα during hypoxia-induced cardiopulmonary adaptation is warranted.

A simple and economical method for unbiasedly quantifying the alveolar size of entire mouse lung tissue utilizing Hematoxylin and Eosin Staining

Alveolar, the smallest structural and functional units within the respiratory system, play a crucial role in maintaining lung function. Alveolar damage is a typical pathological hallmark of respiratory diseases. Nevertheless, there is currently no simple, rapid, economical, and unbiased method for quantifying alveolar size for entire lung tissue. Here, firstly, we conducted lung sample slicing based on the size, shape, and distribution of airway branches of different lobes. Next, we performed HE staining on different slices. Then, we provided an unbiased quantification of alveolar size using free software ImageJ. Through this protocol, we demonstrated that C57Bl/6 mice exhibit varying alveolar sizes among different lobes. Collectively, we provided a simple and unbiased method for a more comprehensive quantification of alveolar size in mice, which holds promise for a broader range of respiratory research using mouse models.

Exploring alveolar recruitability using positive end-expiratory pressure in mice overexpressing TGF-β1: a structure–function analysis

Pre-injured lungs are prone to injury progression in response to mechanical ventilation. Heterogeneous ventilation due to (micro)atelectases imparts injurious strains on open alveoli (known as volutrauma). Hence, recruitment of (micro)atelectases by positive end-expiratory pressure (PEEP) is necessary to interrupt this vicious circle of injury but needs to be balanced against acinar overdistension. In this study, the lung-protective potential of alveolar recruitment was investigated and balanced against overdistension in pre-injured lungs. Mice, treated with empty vector (AdCl) or adenoviral active TGF-β1 (AdTGF-β1) were subjected to lung mechanical measurements during descending PEEP ventilation from 12 to 0 cmH2O. At each PEEP level, recruitability tests consisting of two recruitment maneuvers followed by repetitive forced oscillation perturbations to determine tissue elastance (H) and damping (G) were performed. Finally, lungs were fixed by vascular perfusion at end-expiratory airway opening pressures (Pao) of 20, 10, 5 and 2 cmH2O after a recruitment maneuver, and processed for design-based stereology to quantify derecruitment and distension. H and G were significantly elevated in AdTGF-β1 compared to AdCl across PEEP levels. H was minimized at PEEP = 5–8 cmH2O and increased at lower and higher PEEP in both groups. These findings correlated with increasing septal wall folding (= derecruitment) and reduced density of alveolar number and surface area (= distension), respectively. In AdTGF-β1 exposed mice, 27% of alveoli remained derecruited at Pao = 20 cmH2O. A further decrease in Pao down to 2 cmH2O showed derecruitment of an additional 1.1 million alveoli (48%), which was linked with an increase in alveolar size heterogeneity at Pao = 2–5 cmH2O. In AdCl, decreased Pao resulted in septal folding with virtually no alveolar collapse. In essence, in healthy mice alveoli do not derecruit at low PEEP ventilation. The potential of alveolar recruitability in AdTGF-β1 exposed mice is high. H is optimized at PEEP 5–8 cmH2O. Lower PEEP folds and larger PEEP stretches septa which results in higher H and is more pronounced in AdTGF-β1 than in AdCl. The increased alveolar size heterogeneity at Pao = 5 cmH2O argues for the use of PEEP = 8 cmH2O for lung protective mechanical ventilation in this animal model.

Effect Of Formulation On The Fluffiness And Volume Of A Commercial Cake Premix In Relation To Its Acceptability

Making a commercial cake based on a premix is a matter of finding the balance of key ingredients that influence the uniform distribution and homogeneous size of the pockets in order to obtain an acceptable commercial sponginess in a premix. The objective of this work was to evaluate the formulation of a commercial premix in relation to its fluffiness and volume employing image analysis and its acceptability. Initially, a screening was performed with Taguchi's methodology evaluating statistical descriptors of texture by image analysis and volume. The sponginess was evaluated by means of the statistical descriptors of texture ASM, contrast, IDM, and entropy determined by the GLCM method. Two optimum formulations were obtained, formula A consisting of monoglyceride, egg, oil, sugar, xanthan gum, and baking powder, the values of 4.0, 80.0, 50.0, 70.0, 0.05, and 2.0 percent respectively, and formula B; monoglyceride, egg, oil, sugar, xanthan gum, and baking powder; the values of 7.0, 80.0, 30.0, 70.0, 0.05 and 5.0 percent respectively, which were subjected to an acceptability test with 80 consumers. In the result, according to the statistic t = 0.375858 > α (significance level=0.05), the null hypothesis is rejected and the alternative hypothesis is accepted, which means that there is no statistically significant difference between formulas A and B for consumers. This means that, in a cake, not only the volume is important, but also its sponginess (the latter is due to the correct size, distribution, and dispersion of alveoli, as well as its homogeneity in all the cut surface of the crumb of the cake).

Prognostic significance of alveolar collapse in lung invasive adenocarcinoma and its relationship with tumor infiltrating lymphocytes

This study aims to investigate the correlations between alveolar collapse, tumor size, and tumor infiltrating lymphocytes (TILs), while also evaluating the prognostic significance of alveolar collapse in invasive lung adenocarcinoma. 355 patients with solitary invasive lung adenocarcinoma were divided into two groups based on the maximum diameter of alveolar collapse: alveolar collapse ≤ 5 mm group and alveolar collapse > 5 mm group. Differences in clinicopathological characteristics, tumor size, TILs, and prognosis were compared between the two groups. The alveolar collapse > 5 mm group had a higher mean age, larger tumor diameter, and increased TILs levels compared to the alveolar collapse ≤ 5 mm group (P < 0.05). A moderate positive correlation was observed between alveolar collapse and tumor size (r = 0.646, P < 0.001). Lung adenocarcinoma with alveolar collapse > 5 mm demonstrated superior 5-year survival and acted as an independent prognostic indicator (HR=0.152, P = 0.004) in multivariate Cox regression analysis, alongside tumor size (HR=10.172, P = 0.034) and lymph node metastasis (HR=2.88, P = 0.017). The size of alveolar collapse is associated with TILs abundance, suggesting that the immune microenvironment may play a crucial role in alveolar collapse formation. Pathologists should take note of alveolar collapse in lung adenocarcinoma.

The Effect of Diet Consistency on the Craniofacial Morphology: A review Article.

Mastication is a chewing route, that implicates a group of muscles that are responsible for moving the mandible condyle in the temporomandibular joint (TMJ) to chore food between the teeth in the maxillary and mandibular arches (1) .Regarding the growth of the craniofacial system (CFS),there are an agreement which is strongminded via genetic and ecological aspects (2) . Masticatory forces considered as one of the chief environmental incentives that produce craniofacial difference amongst modern humans. New researeches on a broad variety of creatures, counting those having retro-gnathic post canine teeth, expect that retorts to the force of mastication that determined the superior in the occlusal plane (3) . The effect of masticatory stroke induced by the muscles of the mastication on the development of the morphology of craniofacial portion, has established significant attention in the recent oral invistigations (4) . Meanwhile the skeletal of the CFS adapts to the applied loads by bone remodeling in order to get the optimum formula to resist loads according to Wollf ’s law (5) . CFS has been assumed that it formula is mainly resolute by loading induced by mucsles of mastication. This has been reinforced by numerous clinical and experimental readings (6-9) . Investigational studies displayed that the reduced stresses induced by function on the animals mandibles, whose nourished a lenient diet outcomes in organizational variations in their masticatory systems (10) , in addition to morphological modifications of the lower jaw, like diminished of the alveolar bone size (11, 12) .Diet could be considered as a element of masticatory magnitude. Recent humans in developed countries eat an additional treated and softer diet rather than old humans. The change from hard to soft nourishment has been join by reduce in mandibular dimension and the growth of the alveolar bone, along with enlarged occurrence of malocclusion (1,5,7).

Overtime Histological Changes in the Lungs after Intoxication with Baclofen Alone or in Combination with Ethanol (Experimental Study)

The aim of the study was to evaluate the overtime histological changes in the lungs after intoxication with baclofen alone or in combination with ethanol.Materials and methods. The experiment was carried out on 35 male Wistar rats weighing 290-350 g and aged 20 weeks. The animals were split into 7 equal groups (n=5); test drugs were administered via nasogastric tube: rats from Groups 1, 3 and 5 were treated with baclofen at 85 mg/kg; rats from Groups 2, 4 and 6 received similar dose of baclofen and 40% alcohol by volume at a dose of 7 ml/kg; control group rats were not administered with any drugs. Animals of all groups were removed from the experiment by cervical dislocation under anesthesia (chlorolase) after 3 hours (Groups 1, 2), 4.5 hours (Groups 3, 4) and after 24 hours (Groups 5, 6, and the controls). Lung tissue samples were examined by light microscopy. The nonparametric Kraskel-Wallis test was used for multiple comparisons between the groups, and nonparametric Mann–Whitney test with Bonferroni correction was used for pairwise comparison.Results. Light microscopy showed no pathological changes in the lungs of the Control group animals. Baclofen alone, or in combination with ethanol caused significant circulatory disorders (venular and capillary fullness, hemorrhages in the interalveolar septa (IAS) and alveoli, sludge phenomenon), emphysema, atelectasis and distelectasis, and pulmonary edema. IAS thickness in rats from all experimental groups was different from that in animals from the Control group, all differences confirmed by the Kruskel-Wallis test: H=748, p=0.00001.In Group 1 animals IAS was 44.2% thinner (p=0.00052) vs the control Group, while in all remaining experimental groups it was, on the contrary, thicker: in Group 2 – 57.6% increase in thickness (p=0.000038), in Group 3 – 99 % (p=0.00001), in Group 4 – 2.2-fold increase (p= 0.00001), in Group 5 – 2.1-fold (p= 0.00001), in Group 6 – 2.5-fold increase (p= 0.00001). Most significant increase in IAS thickness (6-fold, p=0.00001) occurred within the period from 3 to 4.5 hours after administration of baclofen, while within the period from 4.5 to 24 hours no statistically significant increase occurred (p=0.99). Co-administration of baclofen and ethanol caused 2.8-fold (p=0.00001) increase in IAS thickness after 3 hours as compared to the effects of baclofen only. IAS thickness at 4.5 hours after baclofen and ethanol co-administration increased by additional 41.8% as compared to thickness at 3 hours (p=0.00001). IAS became 11.8% thicker at 24 hours vs 4.5 hours (p=0.87). At 24 hours IAS was 21.7% (p= 0.0011) thicker after baclofen and ethanol co-administration vs baclofen alone. The alveoli size increased by 69.4% (p=0.00001) in Group 1 animals vs the Control group, by 14.3% (p=0.43) - in Group 2, by 55% (p=0.00004) - in Group 3, by 26.3% (p=0.002) - in Group 4, by 45% (p=0.0003) - in Group 5 (baclofen, 24 h), by 43.3% (p=0.0004) – in Group 6 (baclofen and ethanol, 24 h). Co-administration of baclofen and ethanol initially caused a slight increase in alveoli size, bur 3 hours later there was a visible shrinkage in the diameter of alveoli by 32.5% (p= 0.003) vs baclofen mono, 4.5 hours later – by 18.5% (p= 0.062), and 24 hours later – by 1.2% (p= 0.99), that is, the differences were leveled.Conclusion. The combined effects of baclofen and ethanol induce more severe alterations in pulmonary tissue compared to baclofen alone. The pathological changes in the lungs reached their maximum by 24 hours, which confirmed by morphometric assessment. Morphological changes in pulmonary tissue alongside with established chemical properties of the two agents can be used to diagnose cases of intoxication either with baclofen alone or in combination with ethanol.

Zingiber officinale-Derived Extracellular Vesicles Attenuate Bleomycin-Induced Pulmonary Fibrosis Trough Antioxidant, Anti-Inflammatory and Protease Activity in a Mouse Model.

Idiopathic pulmonary fibrosis (IPF) is the most frequent and severe idiopathic interstitial pneumonia. It is a chronic and progressive disease with a poor prognosis and is a major cause of morbidity and mortality. This disease has no cure; therefore, there is a clinical need to search for alternative treatments with greater efficacy. In this study, we aimed to evaluate the effect of extracellular vesicles (EVs) from Zingiber officinale (EVZO) in a murine model of bleomycin (BLM)-induced IPF administered through an osmotic minipump. EVZO had an average size of 373 nm and a spherical morphology, as identified by scanning electron microscopy. Label-free proteomic analysis of EVZOs was performed by liquid chromatography coupled to mass spectrometry, and 20 proteins were identified. In addition, we demonstrated the protease activity of EVZO by gelatin-degrading zymography assay and the superoxide dismutase (SOD) activity of EVZO by an enzymatic assay. In the BLM-induced IPF mouse model, nasal administration of 50 μg of EVZO induced recovery of alveolar space size and decreased cellular infiltrate, collagen deposition, and expression of α-SMA-positive cells. Additionally, EVZO inhibited inflammatory markers such as iNOS and COX-2, lipid peroxidation, and apoptotic cells. These results show that EVZO may represent a novel natural delivery mechanism to treat IPF.

Role of periosteum during healing of alveolar critical size bone defects in the mandible: a pilot study.

Minipigs present advantages for studying oral bone regeneration; however, standardized critical size defects (CSD) for alveolar bone have not been validated yet. The objectives of this study are to develop a CSD in the mandibular alveolar bone in Aachen minipigs and to further investigate the specific role of periosteum. Three female Aachen minipigs aged 17, 24, and 84months were used. For each minipig, a split-mouth design was performed: an osteotomy (2cm height × 2.5cm length) was performed; the periosteum was preserved on the left side and removed on the right side. Macroscopic, cone beam computed tomography (CBCT), microcomputed tomography (µCT), and histological analyses were performed to evaluate the bone defects and bone healing. In both groups, spontaneous healing was insufficient to restore initial bone volume. The macroscopic pictures and the CBCT results showed a larger bone defect without periosteum. µCT results revealed that BMD, BV/TV, and Tb.Th were significantly lower without periosteum. The histological analyses showed (i) an increased osteoid apposition in the crestal area when periosteum was removed and (ii) an ossification process in the mandibular canal area in response to the surgical that seemed to increase when periosteum was removed. A robust model of CSD model was developed in the alveolar bone of minipigs that mimics human mandibular bone defects. This model allows to further investigate the bone healing process and potential factors impacting healing such as periosteum. This model may be relevant for testing different bone reconstruction strategies for preclinical investigations.

Deep-Masker: A Deep Learning-based Tool to Assess Chord Length from Murine Lung Images.

Chord length is an indirect measure of alveolar size and a critical endpoint in animal models of chronic obstructive pulmonary disease (COPD). In assessing chord length, the lumens of nonalveolar structures are eliminated from measurement by various methods, including manual masking. However, manual masking is resource intensive and can introduce variability and bias. We created a fully automated deep learning-based tool to mask murine lung images and assess chord length to facilitate mechanistic and therapeutic discovery in COPD called Deep-Masker (available at http://47.93.0.75:8110/login). We trained the deep learning algorithm for Deep-Masker using 1,217 images from 137 mice from 12 strains exposed to room air or cigarette smoke for 6 months. We validated this algorithm against manual masking. Deep-Masker demonstrated high accuracy with an average difference in chord length compared with manual masking of -0.3 ± 1.4% (rs = 0.99) for room-air-exposed mice and 0.7 ± 1.9% (rs = 0.99) for cigarette-smoke-exposed mice. The difference between Deep-Masker and manually masked images for change in chord length because of cigarette smoke exposure was 6.0 ± 9.2% (rs = 0.95). These values exceed published estimates for interobserver variability for manual masking (rs = 0.65) and the accuracy of published algorithms by a significant margin. We validated the performance of Deep-Masker using an independent set of images. Deep-Masker can be an accurate, precise, fully automated method to standardize chord length measurement in murine models of lung disease.

Spherical alveolar shapes in live mouse lungs

Understanding how the alveolar mechanics work in live lungs is essential for comprehending how the lung behaves during breathing. Due to the lack of appropriate imaging tools, previous research has suggested that alveolar morphologies are polyhedral rather than spherical based on a 2D examination of alveoli in fixed lungs. Here, we directly observe high-resolution 3D alveoli in live mice lungs utilizing synchrotron x-ray microtomography to show spherical alveolar morphologies from the live lungs. Our measurements from x-ray microtomography show high sphericity, low packing density, big alveolar size, and low osmotic pressure, indicating that spherical alveolar morphologies are natural in living lungs. The alveolar packing fraction is quite low in live lungs, where the spherical alveoli would behave like free bubbles, while the confinement of alveolar clusters in fixed lungs would lead to significant morphological deformations of the alveoli appearing polyhedral. Direct observations of the spherical alveolar shapes will help understand and treat lung disease and ventilation.

A single-breath-hold protocol for hyperpolarized 129 Xe ventilation and gas exchange imaging.

Hyperpolarized 129 Xe MRI (Xe-MRI) is increasingly used to image the structure and function of the lungs. Because 129 Xe imaging can provide multiple contrasts (ventilation, alveolar airspace size, and gas exchange), imaging often occurs over several breath-holds, which increases the time, expense, and patient burden of scans. We propose an imaging sequence that can be used to acquire Xe-MRI gas exchange and high-quality ventilation images within a single, approximately 10 s, breath-hold. This method uses a radial one-point Dixon approach to sample dissolved 129 Xe signal, which is interleaved with a 3D spiral ("FLORET") encoding pattern for gaseous 129 Xe. Thus, ventilation images are obtained at higher nominal spatial resolution (4.2 × 4.2 × 4.2 mm3 ) compared with gas-exchange images (6.25 × 6.25 × 6.25 mm3 ), both competitive with current standards within the Xe-MRI field. Moreover, the short 10 s Xe-MRI acquisition time allows for 1 H "anatomic" images used for thoracic cavity masking to be acquired within the same breath-hold for a total scan time of about 14 s. Images were acquired using this single-breath method in 11 volunteers (N = 4 healthy, N = 7 post-acute COVID). For 11 of these participants, a separate breath-hold was used to acquire a "dedicated" ventilation scan and five had an additional "dedicated" gas exchange scan. The images acquired using the single-breath protocol were compared with those from dedicated scans using Bland-Altman analysis, intraclass correlation (ICC), structural similarity, peak signal-to-noise ratio, Dice coefficients, and average distance. Imaging markers from the single-breath protocol showed high correlation with dedicated scans (ventilation defect percent, ICC = 0.77, p = 0.01; membrane/gas, ICC = 0.97, p = 0.001; red blood cell/gas, ICC = 0.99, p < 0.001). Images showed good qualitative and quantitative regional agreement. This single-breath protocol enables the collection of essential Xe-MRI information within one breath-hold, simplifying scanning sessions and reducing costs associated with Xe-MRI.

Unilateral alveolar cleft size on prenatal 2-D ultrasonography predicts cleft of the secondary palate in fetal unilateral cleft lip: A Pilot Study.

Prenatal diagnosis of cleft palate (CP) is challenging. The current study's objective was to investigate if prenatal alveolar cleft width is associated with the likelihood of a cleft of the secondary palate in unilateral cleft lip (CL). The authors reviewed 2D US images in fetuses with unilateral CL from 1/2012-2/2016. Images of the fetal face were obtained with a linear and/or curved probe in the axial and coronal planes. Measurements of the alveolar ridge gap were taken by the senior radiologist. Post-natal phenotype findings were compared with prenatal findings. Thirty patients with unilateral CL met inclusion criteria; average gestational age was 26.67 ± 5.11 weeks (range 20.71, 36.57 weeks). Ten fetuses were found to have an intact alveolar ridge by prenatal US; postnatal exam confirmed intact secondary palate in all. Small alveolar defects <4 mm were noted in 3 fetuses; postnatal examination documented CP in a single patient. CP was confirmed in 15 of the remaining 17 fetuses who had alveolar cleft width >4 mm. An alveolar defect ≥ 4 mm on prenatal US was associated with greater likelihood of a cleft of the secondary palate (c 2 (2, n=30) = 20.23, p<.001). In the setting of unilateral CL, prenatal US documentation of alveolar defects ≥4 mm are highly predictive of the presence of a cleft of the secondary palate. Conversely, an intact alveolar ridge is associated with an intact secondary palate.

Correlation between lung maturity and backscatter coefficient calculations in fetal lung. Simulations

Fetal lung maturity is a public health problem, and developing quantitative ultrasonic (QUS) techniques has become a possible way of assessing lung development. To estimate the feasibility of using quantitative medical ultrasound, we performed numerical simulations of radio frequency signals scattered from lung tissue. Given the distribution of sizes of alveoli, and wall lining thicknesses corresponding to different stages of lung maturity, we calculate the effective speed of sound using an effective medium approximation. The attenuation and backscattering coefficient is calculated from many-body scattering techniques. Also, for the attenuation and the backscattering coefficient, different statistical configurations are considered to determine the correlation between size of alveoli and acoustic properties. The results using QUS are compared to light scattering techniques (1). Our simulations are compared with ultrasonic measurements made with sponges with different pore sizes following the work of . Once the measurements are analyzed, the sponges are cut and analyzed under a dark-filed microscope to obtain the average size of pores. As a proof of concept, we show that quantitative medical ultrasound can provide information on fetal lung maturity accurately. (1) M. S. Durkee, G. K. Fletcher, C. Carlson, K. Matheson, S. K. Swift, et al. Opt. Lett. Vol. 43, No. 20, 5001 (2018).

Random matrix theory (RMT) to quantify scattering behavior in lung mimicking phantoms

As we previously reported in rodent lungs, RMT parameters (Expected value E(x), and λmax, the eigenvalue with the highest probability) extracted from singular value decomposition (SVD) of inter-element response matrix (IRM) show a significant correlation with fibrosis histology scores. The lack of fibrotic models for larger lungs such as pigs motivated us to investigate porous 3D printed PEGDA phantoms with controllable strut size and alveolar density. We hypothesize that E(x), and λmax can distinguish phantoms with different alveolar size, by evaluating multiple scattering in the backscattered signals. IRMs were acquired using a 128-element linear array L7-4 (Verasonics, at 5.2 MHz central frequency) connected to a Verasonics Vantage ultrasound scanner. Phantoms of 1-inches size with different strut diameters of 0.085, 0.17, and 0.26 mm were used. Attenuation constants for these samples were measured using the Substitution Method at 1 MHz, 2.25MHz, and 5 MHz to evaluate scattering attenuation. E(x), and λmax were evaluated using SVD of the IRM. Attenuation constants, E(x), and λmax all show that the phantoms with larger strut size exhibit more multiple scattering than phantoms with smaller strut size. These preliminary results suggest that such phantoms could be used to mimic pulmonary fibrosis.

The choice of an autocorrelation length in dark-field lung imaging

Respiratory diseases are one of the most common causes of death, and their early detection is crucial for prompt treatment. X-ray dark-field radiography (XDFR) is a promising tool to image objects with unresolved micro-structures such as lungs. Using Talbot-Lau XDFR, we imaged inflated porcine lungs together with Polymethylmethacrylat (PMMA) microspheres (in air) of diameter sizes between 20 and 500 upmu hbox {m} over an autocorrelation range of 0.8–5.2 upmu hbox {m}. The results indicate that the dark-field extinction coefficient of porcine lungs is similar to that of densely-packed PMMA spheres with diameter of {200},upmu hbox {m}, which is approximately the mean alveolar structure size. We evaluated that, in our case, the autocorrelation length would have to be limited to {0.57},upmu hbox {m} in order to image {20},hbox {cm}-thick lung tissue without critical visibility reduction (signal saturation). We identify the autocorrelation length to be the critical parameter of an interferometer that allows to avoid signal saturation in clinical lung dark-field imaging.

Analysis of the alveolar shape in 3-D.

Mechanical forces affect the alveolar shape, depending on location and tissue composition, and vary during the respiratory cycle. This study performs alveolar morphomics in different lobes of human lungs using models generated from three-dimensional (3-D) micro-computed tomography (microCT) images. Cylindrical tissue samples (1.6 cm × 2 cm) were extracted from two nontransplantable donor lungs (one ex-smoker and one smoker, 3 samples per subject) that were air-inflated and frozen solid in liquid nitrogen vapor. Samples were scanned with microCT (11 µm/voxel). Within representative cubic regions of interest (5.5 mm edge length), alveoli were segmented to produce corresponding 3-D models from which quantitative data were obtained. The surface of segmented alveoli (n_alv_total = 23,587) was divided into individual planar surfaces (facets) and angles between facet normals were calculated. Moreover, the number of neighboring alveoli was estimated for every alveolus. In this study, we examined intraindividual differences in alveolar morphology, which were reproducible in the lungs of two subjects. The main aspects are higher mean alveolar volumes (v_alv: 6.64 × 106 and 6.63 × 106 µm3 vs. 5.78 × 106 and 6.29 × 106 µm3) and surface sizes (s_alv: 0.19 and 0.18 mm2 vs. 0.17 mm2 in both lower lobes) in both upper lung lobes compared with the lower lobes. An increasing number of facets (f_alv) from top to bottom (12 and 14 in the upper lobes; 14 and 15 in the lower lobes), as well as a decreasing number of alveolar neighbors (nei_alv: 9 and 8 in the upper lobes; 8 and 7 in the lower lobes) from the upper lobes to the lower lobes were observed. We could observe an increasing ratio of alveolar entrance size to the surface size of the alveoli from top to bottom (S_ratio_alv: 0.71 and 0.64 in the upper lobes, 0.73 and 0.70 in the lower lobes). The angles between facet normals (ang_alv) were larger in the upper lobes (67.72° and 62.44°) of both lungs than in the lower lobes (66.19° and 61.30°). By using this new approach of analyzing alveolar 3-D data, which enables the estimation of facet, neighbor, and shape characteristics, we aimed to establish the baseline measures for in-depth studies of mechanical conditions and morphology.