Geometry and respiratory displacement of human ribs

The three-dimensional coordinates of points in the ribs of two supine relaxed males, holding their breath at functional residual capacity (FRC) and with their glottis closed at total lung capacity (TLC), were obtained from volumetric X-ray computed tomographical images. The orientation of planes that best fit the data for each rib at each lung volume and the circular arcs that fit the points in the planes of the ribs were determined, and average values of these geometrical parameters for ribs 3–7 are reported. The planes of the ribs at TLC can be described as displaced from the planes at FRC by a rotation about an axis that passes near the spine. The pump handle and bucket handle components of rotation are 11 and 13 degrees, respectively, for rib 3 and both decrease with increasing rib number to 7 and 10 degrees at rib 7. The angles between the axes of rotation and the midplane are approximately 35 degrees for all 5 ribs. The radii of the circular arcs fit to the data at TLC are slightly larger than those at FRC, and this suggests that there is a small component of rotation normal to the plane of the rib.

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Geometry and kinematics of dog ribs

Journal of Applied Physiology ◽

10.1152/jappl.1989.67.2.707 ◽

1989 ◽

Vol 67 (2) ◽

pp. 707-712 ◽

Cited By ~ 24

Author(s):

S. S. Margulies ◽

J. R. Rodarte ◽

E. A. Hoffman

Keyword(s):

Coordinate System ◽

Functional Residual Capacity ◽

Total Lung Capacity ◽

Beagle Dogs ◽

X Ray ◽

Computed Tomographic ◽

Lung Capacity ◽

Residual Capacity ◽

Bucket Handle ◽

Geometry And Kinematics

Five anesthetized supine beagle dogs were scanned using a fast, multislice computed tomographic X-ray technique to determine the orientation of the ribs at total lung capacity (TLC) and functional residual capacity (FRC). A plane was fit to each rib using a coordinate system in which the z-axis was aligned approximately cephalocaudally and the x-z-plane coincided with the sagittal midplane. The orientation of each plane was described by “pump-handle” and “bucket-handle” angles. The ribs rotated downward and inward during a passive deflation of the lungs from TLC to FRC. Rib displacement was not uniform: bucket-handle motion was predominant in the upper ribs, and pump- and bucket-handle motions were equal in the lower ribs. The change in the pump-handle angles between TLC and FRC was approximately 6 degrees for ribs 3–8, and the change in the bucket-handle angles decreased with rib number from 16 degrees for rib 3 to 6 degrees for rib 8. Rib shape was described by fitting an ellipse to the data for each rib; the ribs became larger and more circular with increasing rib number.

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Zone of apposition in the passive diaphragm of the dog

Journal of Applied Physiology ◽

10.1152/jappl.1996.81.5.1929 ◽

1996 ◽

Vol 81 (5) ◽

pp. 1929-1940 ◽

Cited By ~ 9

Author(s):

Aladin M. Boriek ◽

Joseph R. Rodarte ◽

Susan S. Margulies

Keyword(s):

Surface Area ◽

Lung Volume ◽

Three Dimensional ◽

Beagle Dogs ◽

Rib Cage ◽

X Ray ◽

Lung Capacity ◽

Regional Area ◽

Residual Capacity ◽

Spatial Coordinates

Boriek, Aladin M., Joseph R. Rodarte, and Susan S. Margulies. Zone of apposition in the passive diaphragm of the dog. J. Appl. Physiol. 81(5): 1929–1940, 1996.—We determined the regional area of the diaphragmatic zone of apposition (ZAP) as well as the regional craniocaudal extent of the ZAP (ZAPht) of the passive diaphragm in six paralyzed anesthetized beagle dogs (8–12 kg) at residual lung volume (RV), functional residual capacity (FRC), FRC + 0.25 and FRC + 0.5 inspiratory capacity, and total lung capacity (TLC) in prone and supine postures. To identify the caudal boundary of the ZAP, 17 lead markers (1 mm) were sutured to the abdominal side of the costal and crural diaphragms around the diaphragm insertion on the chest wall. Two weeks later, the dogs’ caudal thoraces were scanned by the use of the dynamic spatial reconstructor (DSR), a prototype fast volumetric X-ray computer tomographic scanner, developed at the Mayo Clinic. The three-dimensional spatial coordinates of the markers were identified (±1.4 mm), and the cranial boundary of the ZAP was determined from 30–40 1.4-mm-thick sagittal and coronal slices in each DSR image. We interpolated the DSR data to find the position of the cranial and caudal boundaries of the ZAP every 5° around the thorax and computed the distribution of regional variation of area of the ZAP and ZAPht as well as the total area of ZAP. The ZAPht and area of ZAP increased as lung volume decreased and were largest near the lateral extremes of the rib cage. We measured the surface area of the rib cage cephaled to the ZAP ( A L) in both postures in another six beagle dogs (12–16 kg) of similar stature, scanned previously in the DSR. We estimated the entire rib cage surface area ( A rc = A ZAP + A L). The A ZAP as a percentage of A rc increased more than threefold as lung volume decreased from TLC to RV, from ∼9 to 29% of A rc.

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Localized compliance of small airways in excised rat lungs using microfocal X-ray computed tomography

Journal of Applied Physiology ◽

10.1152/japplphysiol.00624.2003 ◽

2004 ◽

Vol 96 (5) ◽

pp. 1665-1673 ◽

Cited By ~ 31

Author(s):

Toshihiro Sera ◽

Hideki Fujioka ◽

Hideo Yokota ◽

Akitake Makinouchi ◽

Ryutaro Himeno ◽

...

Keyword(s):

Computed Tomography ◽

Total Lung Capacity ◽

Lung Mechanics ◽

Small Airways ◽

Step Method ◽

X Ray ◽

Lung Capacity ◽

Residual Capacity ◽

X Ray Computed ◽

End Tidal

Airway compliance is a key factor in understanding lung mechanics and is used as a clinical diagnostic index. Understanding such mechanics in small airways physiologically and clinically is critical. We have determined the “morphometric change” and “localized compliance” of small airways under “near”-physiological conditions; namely, the airways were embedded in parenchyma without dehydration and fixation. Previously, we developed a two-step method to visualize small airways in detail by staining the lung tissue with a radiopaque solution and then visualizing the tissue with a cone-beam microfocal X-ray computed tomography system (Sera et al. J Biomech 36: 1587-1594, 2003). In this study, we used this technique to analyze changes in diameter and length of the same small airways (∼150 μm ID) and then evaluated the localized compliance as a function of airway generation ( Z). For smaller (<300-μm-diameter) airways, diameter was 36% larger at end-tidal inspiration and 89% larger at total lung capacity; length was 18% larger at end-tidal inspiration and 43% larger at total lung capacity than at functional residual capacity. Diameter, especially at smaller airways, did not behave linearly with V1/3 (where V is volume). With increasing lung pressure, diameter changed dramatically at a particular pressure and length changed approximately linearly during inflation and deflation. Percentage of airway volume for smaller airways did not behave linearly with that of lung volume. Smaller airways were generally more compliant than larger airways with increasing Z and exhibited hysteresis in their diameter behavior. Airways at higher Z deformed at a lower pressure than those at lower Z. These results indicated that smaller airways did not behave homogeneously.

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Quantification of thoracic volumes by three-dimensional imaging

Journal of Applied Physiology ◽

10.1152/jappl.1987.62.2.591 ◽

1987 ◽

Vol 62 (2) ◽

pp. 591-598 ◽

Cited By ~ 29

Author(s):

S. Krayer ◽

K. Rehder ◽

K. C. Beck ◽

P. D. Cameron ◽

E. P. Didier ◽

...

Keyword(s):

Three Dimensional ◽

Thoracic Cavity ◽

Volume Changes ◽

X Ray ◽

Relative Contribution ◽

Before And After ◽

Residual Capacity ◽

X Ray Computed ◽

Trapped Gas ◽

Gas Volume

End-expiratory thoracic cavity volume (Vthx) was measured in eight volunteers lying supine by three-dimensional X-ray computed tomography using the Dynamic Spatial Reconstructor. Untrapped end-expiratory pulmonary gas volume at functional residual capacity (FRC) was determined by nitrogen clearance. Both measurements were done before and after induction of anesthesia-paralysis. After induction of anesthesia-paralysis, Vthx and FRC were consistently and significantly (P less than 0.01) reduced by 0.28 +/- 0.22 (SD) and 0.59 +/- 0.24 liter, respectively. The reduction of FRC was larger than the reduction of Vthx (delta Vthx) in six of the eight subjects, a finding suggesting that intrathoracic fluid (blood) plus trapped gas volume (Vtt) increased. Changes in Vthx were partitioned into volume changes from the thoracic rib cage (delta Vrc) and from shape and/or position changes of the diaphragm (delta Vdi). delta Vrc contributed significantly (0.17 +/- 0.15 liter, P less than 0.02) to delta Vthx, whereas delta Vdi contributed only in four of the eight subjects. We conclude that delta Vrc, delta Vdi, and delta Vtt contribute to the reduction of FRC after induction of anesthesia-paralysis in humans; the relative contribution of them varies among subjects.

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Three‐dimensional X‐ray‐computed tomography of 3300‐ to 6000‐year‐old Citrullus seeds from Libya and Egypt compared to extant seeds throws doubts on species assignments

Plants People Planet ◽

10.1002/ppp3.10220 ◽

2021 ◽

Author(s):

Katherine A. Wolcott ◽

Guillaume Chomicki ◽

Yannick M. Staedler ◽

Krystyna Wasylikowa ◽

Mark Nesbitt ◽

...

Keyword(s):

Computed Tomography ◽

Three Dimensional ◽

X Ray ◽

X Ray Computed

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Cover Feature: Non‐Destructive Three‐Dimensional Imaging of Metal Organic Framework Mixed Matrix Membranes using Lab‐based X‐ray Computed Tomography (Chemistry ‐ Methods 5/2021)

Chemistry–Methods ◽

10.1002/cmtd.202100034 ◽

2021 ◽

Vol 1 (5) ◽

pp. 202-202

Author(s):

Anton Jansson ◽

Ignacio Luz ◽

Ching‐Chang Chung ◽

Mustapha Soukri

Keyword(s):

Computed Tomography ◽

Metal Organic Framework ◽

Three Dimensional ◽

Mixed Matrix Membranes ◽

Mixed Matrix ◽

Three Dimensional Imaging ◽

X Ray ◽

Metal Organic ◽

X Ray Computed ◽

Non Destructive

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Visualizing Fluid Flows With X-Rays

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2007-37023 ◽

2007 ◽

Cited By ~ 4

Author(s):

Theodore J. Heindel ◽

Terrence C. Jensen ◽

Joseph N. Gray

Keyword(s):

Computed Tomography ◽

Flow Visualization ◽

Three Dimensional ◽

Fluid Flows ◽

X Rays ◽

Radiographic Images ◽

Optical Access ◽

X Ray ◽

X Ray Computed ◽

Density Map

There are several methods available to visualize fluid flows when one has optical access. However, when optical access is limited to near the boundaries or not available at all, alternative visualization methods are required. This paper will describe flow visualization using an X-ray system that is capable of digital X-ray radiography, digital X-ray stereography, and digital X-ray computed tomography (CT). The unique X-ray flow visualization facility will be briefly described, and then flow visualization of various systems will be shown. Radiographs provide a two-dimensional density map of a three dimensional process or object. Radiographic images of various multiphase flows will be presented. When two X-ray sources and detectors simultaneously acquire images of the same process or object from different orientations, stereographic imaging can be completed; this type of imaging will be demonstrated by trickling water through packed columns and by absorbing water in a porous medium. Finally, local time-averaged phase distributions can be determined from X-ray computed tomography (CT) imaging, and this will be shown by comparing CT images from two different gas-liquid sparged columns.

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