| 1. |
- Borisova, Elena, et al.
(författare)
-
Micrometer-resolution X-ray tomographic full-volume reconstruction of an intact post-mortem juvenile rat lung
- 2021
-
Ingår i: Histochemistry and Cell Biology. - : Springer. - 0948-6143 .- 1432-119X. ; 155, s. 215-226
-
Tidskriftsartikel (refereegranskat)abstract
- In this article, we present an X-ray tomographic imaging method that is well suited for pulmonary disease studies in animal models to resolve the full pathway from gas intake to gas exchange. Current state-of-the-art synchrotron-based tomographic phase-contrast imaging methods allow for three-dimensional microscopic imaging data to be acquired non-destructively in scan times of the order of seconds with good soft tissue contrast. However, when studying multi-scale hierarchically structured objects, such as the mammalian lung, the overall sample size typically exceeds the field of view illuminated by the X-rays in a single scan and the necessity for achieving a high spatial resolution conflicts with the need to image the whole sample. Several image stitching and calibration techniques to achieve extended high-resolution fields of view have been reported, but those approaches tend to fail when imaging non-stable samples, thus precluding tomographic measurements of large biological samples, which are prone to degradation and motion during extended scan times. In this work, we demonstrate a full-volume three-dimensional reconstruction of an intact rat lung under immediate post-mortem conditions and at an isotropic voxel size of (2.75 mu m)(3). We present the methodology for collecting multiple local tomographies with 360 degrees extended field of view scans followed by locally non-rigid volumetric stitching. Applied to the lung, it allows to resolve the entire pulmonary structure from the trachea down to the parenchyma in a single dataset. The complete dataset is available online ().
|
|
| 2. |
- Dejea, Hector, et al.
(författare)
-
In Situ Loading and Time-Resolved Synchrotron-Based Phase Contrast Tomography for the Mechanical Investigation of Connective Knee Tissues : A Proof-of-Concept Study
-
Ingår i: Advanced Science. - 2198-3844.
-
Tidskriftsartikel (refereegranskat)abstract
- Articular cartilage and meniscus transfer and distribute mechanical loads in the knee joint. Degeneration of these connective tissues occurs during the progression of knee osteoarthritis, which affects their composition, microstructure, and mechanical properties. A deeper understanding of disease progression can be obtained by studying them simultaneously. Time-resolved synchrotron-based X-ray phase-contrast tomography (SR-PhC-µCT) allows to capture the tissue dynamics. This proof-of-concept study presents a rheometer setup for simultaneous in situ unconfined compression and SR-PhC-µCT of connective knee tissues. The microstructural response of bovine cartilage (n = 16) and meniscus (n = 4) samples under axial continuously increased strain, or two steps of 15% strain (stress–relaxation) is studied. The chondrocyte distribution in cartilage and the collagen fiber orientation in the meniscus are assessed. Variations in chondrocyte density reveal an increase in the top 40% of the sample during loading, compared to the lower half. Meniscus collagen fibers reorient perpendicular to the loading direction during compression and partially redisperse during relaxation. Radiation damage, image repeatability, and image quality assessments show little to no effects on the results. In conclusion, this approach is highly promising for future studies of human knee tissues to understand their microstructure, mechanical response, and progression in degenerative diseases.
|
|
| 3. |
- Lovric, Goran, et al.
(författare)
-
A multi-purpose imaging endstation for high-resolution micrometer-scaled sub-second tomography
- 2016
-
Ingår i: Physica Medica. - : Elsevier BV. - 1120-1797. ; 32:12, s. 1771-1778
-
Tidskriftsartikel (refereegranskat)abstract
- Time-resolved imaging of dynamic processes, ranging from biological in vivo studies to materials under in situ and in operando conditions, requires a flexible endstation capable of controlling complex components that interact in different configurations and at high speeds. At the X02DA TOMCAT beamline we have recently achieved in situ tomographic measurements at a rate of 20 Hz. Independently, we have shown the feasibility of in vivo lung imaging down to the micrometer scale. In the present paper, we discuss the latest developments in view of instrumentation and the accompanying components for achieving these two types of measurements. As the prime example, we focus on the technical requirements for in vivo tomographic microscopy of the lung at the micrometer scale in terms of acquisition schemes, triggering and radiation dose. We identify ultra-short single-projection exposures combined with accurate triggering capabilities as the main prerequisites to obtain high-quality reconstructions while limiting the X-ray dose imparted on the living sample. The presented endstation offers generic high-speed imaging capabilities, as it is compatible with a variety of experimental setups and suitable for a wide range of time-resolved studies.
|
|
| 4. |
- Mokso, Rajmund, et al.
(författare)
-
GigaFRoST : The gigabit fast readout system for tomography
- 2017
-
Ingår i: Journal of Synchrotron Radiation. - 0909-0495. ; 24:6, s. 1250-1259
-
Tidskriftsartikel (refereegranskat)abstract
- Owing to recent developments in CMOS technology, it is now possible to exploit tomographic microscopy at third-generation synchrotron facilities with unprecedented speeds. Despite this rapid technical progress, one crucial limitation for the investigation of realistic dynamic systems has remained: A generally short total acquisition time at high frame rates due to the limited internal memory of available detectors. To address and solve this shortcoming, a new detection and readout system, coined GigaFRoST, has been developed based on a commercial CMOS sensor, acquiring and streaming data continuously at 7.7GBs-1 directly to a dedicated backend server. This architecture allows for dynamic data pre-processing as well as data reduction, an increasingly indispensable step considering the vast amounts of data acquired in typical fast tomographic experiments at synchrotron beamlines (up to several tens of TByte per day of raw data).The GigaFRoST detector enables high acquisition rates and long scanning times for dynamic experiments.
|
|
