The Mean Linear Intercept (Lm) in the Lung: An Analysis of Line Segment Lengths

2019 ◽  
pp. 485-491
Author(s):  
Jefferson Lima de Santana ◽  
Renato de Lima Vitorasso ◽  
Maria Aparecida de Oliveira ◽  
Henrique Takachi Moriya
Keyword(s):  
Line Segment ◽  
Mean Linear Intercept ◽  
The Mean

INVESTIGATION ON MULTISETS MIXTURE LEARNING BASED OBJECT DETECTION

2007 ◽  
Vol 21 (08) ◽  
pp. 1339-1351 ◽  
Author(s):  
ZHI-YONG LIU ◽  
HONG QIAO ◽  
LEI XU
Keyword(s):  
Object Detection ◽  
Hough Transform ◽  
Line Segment ◽  
Reconstruction Error ◽  
Mean Square ◽  
Noise Resistance ◽  
Generalized Hough Transform ◽  
The Mean ◽  
Sample Reconstruction

By minimizing the mean square reconstruction error, multisets mixture learning (MML) provides a general approach for object detection in image. To calculate each sample reconstruction error, as the object template is represented by a set of contour points, the MML needs to inefficiently enumerate the distances between the sample and all the contour points. In this paper, we develop the line segment approximation (LSA) algorithm to calculate the reconstruction error, which is shown theoretically and experimentally to be more efficient than the enumeration method. It is also experimentally illustrated that the MML based algorithm has a better noise resistance ability than the generalized Hough transform (GHT) based counterpart.

Function–Structure Correlation Studies on Excised Hamster Lungs in Papain-induced Emphysema

1973 ◽  
Vol 51 (9) ◽  
pp. 635-641 ◽  
Author(s):  
P. A. Martorana ◽  
N. W. McKeel ◽  
J. W. Richard ◽  
N. N. Share
Keyword(s):  
Correlation Coefficients ◽  
Histological Evaluation ◽  
Functional Tests ◽  
Elastic Recoil ◽  
Mean Values ◽  
Functional Changes ◽  
High Prediction ◽  
Mean Linear Intercept ◽  
Structure Correlation ◽  
The Mean

Emphysematous lesions induced by a single exposure of hamsters to papain aerosol were evaluated both physiologically (lung elastic recoil) and histologically (mean linear intercept). The extent of the developed lesions was directly related to the concentration of papain employed, and progressed with time following exposure. Histological evaluation was most sensitive for quantitation of minimal lesions; an approximate 20% increase of the mean linear intercept being required for significant functional changes. Maximal mean increase of the mean linear intercept compatible with survival was approximately 75%. Using raw data values, all functional tests exhibited high correlation coefficients (r) with histological evaluation, but prediction efficiencies (r2) were below a practically acceptable value of 75%. However, using group mean values, thereby reducing individual biological variations, higher correlation coefficients as well as high prediction efficiencies were obtained for all functional tests with histological evaluation. In this regard, best prediction efficiencies were obtained for the functional specific static compliance and specific volume at full inflation versus the morphological mean linear intercept.

Morphological Quantitation of Emphysema: A Debate

2006 ◽  
Vol 100 (4) ◽  
pp. 1419-1421 ◽  
Author(s):  
Ewald R. Weibel
Keyword(s):  
Normal Tissue ◽  
Equivalent Diameter ◽  
Reliable Index ◽  
Letters To The Editor ◽  
Large Variability ◽  
Tissue Sections ◽  
Automated Method ◽  
Linear Dimensions ◽  
Mean Linear Intercept ◽  
The Mean

The following series of letters to the editor concerns a recently published morphologic method proposed by Parameswaran and colleagues for sensitive, early detection of emphysema ( J Appl Physiol 100: 186–193, 2006). The validity of the proposed method was critiqued by Ewald Weibel, and, in turn, this critique was rebutted by Parameswaran et al. Additional brief commentaries were contributed by scientists working in the field. Further comments on this important topic are welcome. The following is the abstract of the article discussed in the subsequent letter: The mean linear intercept ( Lm) can be used to estimate the surface area for gas exchange in the lung. However, in recent years it is most commonly used as an index for characterizing the enlargement of airspaces in emphysema and the associated severity of structural destruction in the lung. Specifically, an increase in Lm is thought to result from an increase in airspace sizes. In this paper, we examined how accurately Lm measures the linear dimensions of airspaces from histological sections and a variety of computer-generated test images. To this end, we developed an automated method for measuring linear intercepts from digitized images of tissue sections and calculate Lm as their mean. We examined how the shape of airspaces and the variability of their sizes influence Lm as well as the distribution of linear intercepts. We found that for a relatively homogeneous enlargement of airspaces, Lm was a reliable index for detecting emphysema. However, in the presence of spatial heterogeneities with a large variability of airspace sizes, Lm did not significantly increase and sometimes even decreased compared to its value in normal tissue. We also developed an automated method for measuring the area and computed an equivalent diameter of each individual airspace that is independent of shape. Finally, we introduced new indexes based on the moments of diameter that we found to be more reliable than Lm to characterize airspace enlargement in the presence of heterogeneities.

scholarly journals A new experimental model of cigarette smoke-induced emphysema in Wistar rats

2014 ◽  
Vol 40 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Rodrigo de las Heras Kozma ◽  
Edson Marcelino Alves ◽  
Valter Abraao Barbosa-de-Oliveira ◽  
Fernanda Degobbi Tenorio Quirino dos Santos Lopes ◽  
Renan Cenize Guardia ◽  
...  
Keyword(s):  
Lung Function ◽  
Cigarette Smoke ◽  
Murine Model ◽  
Wistar Rats ◽  
Control Group ◽  
Therapeutic Approaches ◽  
Viable Option ◽  
Male Wistar Rats ◽  
Mean Linear Intercept ◽  
The Mean

OBJECTIVE: To describe a new murine model of cigarette smoke-induced emphysema. METHODS: Twenty-four male Wistar rats were divided into two groups: the cigarette smoke group, comprising 12 rats exposed to smoke from 12 commercial filter cigarettes three times a day (a total of 36 cigarettes per day) every day for 30 weeks; and the control group, comprising 12 rats exposed to room air three times a day every day for 30 weeks. Lung function was assessed by mechanical ventilation, and emphysema was morphometrically assessed by measurement of the mean linear intercept (Lm). RESULTS: The mean weight gain was significantly (approximately ten times) lower in the cigarette smoke group than in the control group. The Lm was 25.0% higher in the cigarette smoke group. There was a trend toward worsening of lung function parameters in the cigarette smoke group. CONCLUSIONS: The new murine model of cigarette smoke-induced emphysema and the methodology employed in the present study are effective and reproducible, representing a promising and economically viable option for use in studies investigating the pathophysiology of and therapeutic approaches to COPD.

Alveolar size as a determinant of pulmonary distensibility in mammalian lungs

1983 ◽  
Vol 54 (3) ◽  
pp. 837-845 ◽  
Author(s):  
P. S. Haber ◽  
H. J. Colebatch ◽  
C. K. Ng ◽  
I. A. Greaves
Keyword(s):  
Static Pressure ◽  
Volume Ratio ◽  
Relative Contribution ◽  
Human Lungs ◽  
Elastic Forces ◽  
Mean Size ◽  
Mean Linear Intercept ◽  
The Common ◽  
The Mean ◽  
Alveolar Surface

Pulmonary distensibility depends on surface tension and tissue elastic forces, but the relative contribution of each to total lung recoil remains incompletely defined. By applying an exponential analysis to static pressure-volume curves obtained from the excised lungs of cats, dogs, and rats with air and saline filling, the exponential constant K (an index of lung distensibility) was related to the mean linear intercept Lm (a morphometric estimate of the mean size of peripheral air spaces at maximal inflation). K for air filling (Ka) was unrelated to K for saline filling (Ks), and Ks was unrelated to Lm, but similar highly significant regressions of Ka on Lm were found in each species, and the common regression was similar to that described previously for human lungs. Approximately 86% of the variance in lung distensibility (Ka) within and between species was explained by Lm. Because Lm determines the size of air spaces, and therefore the alveolar surface-to-volume ratio, the findings indicate that the density of surface forces is the major determinant of lung distensibility in the air-filled state.

scholarly journals Fully automated estimation of the mean linear intercept in histopathology images of mouse lung tissue

2021 ◽  
Vol 8 (02) ◽  
Author(s):  
Sina Salsabili ◽  
Marissa Lithopoulos ◽  
Shreyas Sreeraman ◽  
Arul Vadivel ◽  
Bernard Thébaud ◽  
...  
Keyword(s):  
Lung Tissue ◽  
Mouse Lung ◽  
Mean Linear Intercept ◽  
The Mean ◽  
Histopathology Images ◽  
Mouse Lung Tissue

Structure of Nickel and Nickel-Cobalt Electrodeposits

1972 ◽  
Vol 30 ◽  
pp. 656-657 ◽  
Author(s):  
Anthony W. Thompson
Keyword(s):  
Aqueous Solution ◽  
Fracture Toughness ◽  
Grain Size ◽  
Room Temperature ◽  
Pure Nickel ◽  
Stress Axis ◽  
Nickel Cobalt ◽  
Thin Foils ◽  
Mean Linear Intercept ◽  
The Mean

Electrodeposited plates 6 mm thick were prepared from sulfamate baths by J. W. Dini and H. R. Johnson of this laboratory. The plates were pure nickel or an alloy of 57 Ni-43 Co. Tensile and fracture toughness specimens were machined from these plates; thin foils were cut parallel to the deposition plane, and also perpendicular to that plane and to the stress axis of tensile specimens. R. E. Gorniak prepared the foils by electropolishing at 3 V in an aqueous solution of 48% H3SO4, 32% H2SO4 at room temperature. Foils were examined in a Philips EM300.As Fig. 1 shows, the grain size of the nickel was uniform and small. The true volume grain diameter d was calculated from the mean linear intercept The variations in contrast between grains in Fig. 1 persisted through large, slowly-performed changes in tilt, which suggests that a strong texture was not present.

A species comparison of alveolar size and surface forces

1987 ◽  
Vol 62 (5) ◽  
pp. 1865-1871 ◽  
Author(s):  
H. Lum ◽  
W. Mitzner
Keyword(s):  
Surface Tension ◽  
Static Pressure ◽  
Total Lung Capacity ◽  
Mammalian Species ◽  
Lung Capacity ◽  
Minimum Surface ◽  
Minimum Surface Tension ◽  
Mean Linear Intercept ◽  
The Mean ◽  
Complex Manner

The independent roles of alveolar size and surface tension in relation to lung stability were investigated in 11 different mammalian species whose body weight ranged from 0.03 to 50 kg. This range in species provided a wide variation in subgross anatomy as well as a fourfold range in alveolar diameter. Alveolar diameter was estimated from the mean linear intercept (Lm) of fixed lungs. Quasi-static pressure-volume curves were determined in excised lungs and the percent volume remaining on deflation from total lung capacity at 30 cmH2O to 10 cmH2O (%V10) provided an index of deflation stability related to functional surfactant. Surface tension of lung extract was measured in the Wilhelmy balance, and the minimum surface tension measured provided an index of surface tension lowering capacity of surfactant. Relationships of %V10 with alveolar diameter and surface tension with alveolar diameter were examined for correlations. Our results indicated that despite a range in Lm between 31 and 133 micron (mouse to pig), %V10 did not change in proportion with Lm across species. Similarly, minimum surface tension was about the same (6.1 to 8.8 dyn/cm) across a threefold difference in alveolar diameter. These results suggest that a stable alveolar configuration is maintained by both surface and tissue forces in a complex manner yet to be analyzed.

Airway and tissue behavior during early response in sensitized rats: role of 5-HT and LTD4

1996 ◽  
Vol 80 (2) ◽  
pp. 583-590 ◽  
Author(s):  
T. Nagase ◽  
M. J. Dallaire ◽  
M. S. Ludwig
Keyword(s):  
Early Response ◽  
Tissue Response ◽  
Brown Norway ◽  
Leukotriene D4 ◽  
Mechanically Ventilated ◽  
Airway Constriction ◽  
Tissue Resistance ◽  
Mean Linear Intercept ◽  
The Mean

We have recently demonstrated that tissue resistance increases during the early response (ER) to antigen challenge in sensitized Brown-Norway rats. The purpose of the present study was to investigate the role of the potential ER mediators 5-hydroxytryptamine (5-HT) and leukotriene D4 (LTD4) in the airway and tissue response. We sensitized the rats with ovalbumin (OA) and performed experiments on anesthetized, open-chested, mechanically ventilated [breathing frequency = 1 Hz, tidal volume = 12 ml/kg, positive end-expiratory pressure (PEEP) = 3 cmH2O] animals. We affixed alveolar capsules to the lungs to measure alveolar pressure and calculated the resistance of lung (RL), tissue (Rti), and airway (Raw). To assess the effects of LTD4 and 5-HT, we administered the antagonists methysergide (5-HT antagonist) and MK-571 (LTD4 antagonist) before challenge. To assess lung morphometry during the ER, the lungs of four animals from each group were frozen with liquid nitrogen (PEEP = 3 cmH2O). Airway constriction was assessed by measuring the ratio of the airway lumen to the ideally relaxed airway (Abm/A*bm). Tissue distortion was assessed by measuring the mean linear intercept between alveolar walls (Lm), an atelectasis index (ATI) derived by calculating the ratio of tissue to air space, and SD of the two (SD-Lm and SD-ATI). In all animals receiving OA but no antagonists, an ER was seen (RL, Rti, and Raw = 180.7 +/- 6.1, 155.4 +/- 8.2, and 223.1 +/- 14.0% of baseline, respectively). Methysergide significantly inhibited the ER (RL, Rti, and Raw = 117.0 +/- 5.9, 101.2 +/- 1.6, 133.7 +/- 10.2%, respectively), whereas MK-571 partially reduced the ER (RL, Rti, and Raw = 144.2 +/- 5.6, 132.9 +/- 5.7, and 155.5 +/- 9.2%, respectively). Abm/A*bm was significantly decreased, and SD-Lm and SD-ATI were significantly increased in animals receiving OA alone and in those receiving MK-571 before OA challenge. These data suggest that alterations in both airways and tissues contribute to the ER and that 5-HT and, to a lesser degree, LTD4 are important mediators of the ER in this rat model of extrinsic asthma.

Structural changes in elastic fibers after pancreatic elastase administration in hamsters

1992 ◽  
Vol 72 (4) ◽  
pp. 1473-1479 ◽  
Author(s):  
R. R. Mercer ◽  
J. D. Crapo
Keyword(s):  
Structural Changes ◽  
Ultrastructural Changes ◽  
Elastic Fibers ◽  
Control Group ◽  
Control Groups ◽  
Pancreatic Elastase ◽  
Air Space ◽  
Mean Linear Intercept ◽  
Unit Dose ◽  
The Mean

Ultrastructural changes in lung parenchymal elastic fibers were studied morphometrically 1, 4, and 12 wk after a single 12-unit dose of pancreatic elastase and in a saline-instilled control group. The mean linear intercept of the parenchymal air spaces was increased in the 1-, 4-, and 12-wk post-elastase instillation groups compared with age-matched controls. The volume of alveolar connective tissue fibers predominantly composed of elastin (elastic fibers) was decreased by 35% 1 wk after the instillation of elastase but returned to control levels by 4 wk. Although the total volume of elastic fibers was normal 12 wk after instillation of elastase, the volume of elastic fibers in alveolar entrance rings remained significantly reduced. In serial sections of elastic fibers, numerous gaps or separations in the normally continuous band of elastic fibers that encircle each alveolus were identified 1 wk after elastase instillation. There were 169 +/- 8 (SE), 62 +/- 32, and 12 +/- 6 gaps per millimeter of alveolar entrance ring circumference at 1, 4, and 12 wk, respectively, in the elastase-treated groups. The number of gaps at 12 wk was equivalent to two gaps or discontinuities in the elastic fibers of every alveolar entrance ring. No gaps or separations in elastic fibers were detected at 1, 4, or 12 wk in the control groups. These defects occur in concordance with the progression of air space enlargement and presumably contribute to the progression of air space enlargement that occurs after the elastin content of the tissue has returned to normal.

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