Synchrotron-based phase-contrast micro-CT as a tool for understanding pulmonary vascular pathobiology and the 3-D microanatomy of alveolar capillary dysplasia

Abstract

This study aimed to explore the value of synchrotron-based phase-contrast microcomputed tomography (micro-CT) in pulmonary vascular pathobiology. The microanatomy of the lung is complex with intricate branching patterns. Tissue sections are therefore difficult to interpret. Recruited intrapulmonary bronchopulmonary anastomoses (IBAs) have been described in several forms of pulmonary hypertension, including alveolar capillary dysplasia with misaligned pulmonary veins (ACD/MPV). Here, we examine paraffin-embedded tissue using this nondestructive method for high-resolution three-dimensional imaging. Blocks of healthy and ACD/MPV lung tissue were used. Pulmonary and bronchial arteries in the ACD/MPV block had been preinjected with dye. One section per block was stained, and areas of interest were marked to allow precise beam-alignment during image acquisition at the X02DA TOMCAT beamline (Swiss Light Source). A ×4 magnifying objective coupled to a 20-µm thick scintillating material and a sCMOS detector yielded the best trade-off between spatial resolution and field-of-view. A phase retrieval algorithm was applied and virtual tomographic slices and video clips of the imaged volumes were produced. Dye injections generated a distinct attenuation difference between vessels and surrounding tissue, facilitating segmentation and three-dimensional rendering. Histology and immunohistochemistry post-imaging offered complementary information. IBAs were confirmed in ACD/MPV, and the MPVs were positioned like bronchial veins/venules. We demonstrate the advantages of using synchrotron-based phase-contrast micro-CT for three-dimensional characterization of pulmonary microvascular anatomy in paraffin-embedded tissue. Vascular dye injections add additional value. We confirm intrapulmonary shunting in ACD/MPV and provide support for the hypothesis that MPVs are dilated bronchial veins/venules.

Vascular dimorphism ensured by regulated proteoglycan dynamics favors rapid umbilical artery closure at birth

“…Three-dimensional imaging of term human umbilical cords, using synchrotron-based phase contrast micro-CT with effective pixel size 1.63 × 1.63 μm 2 ( Norvik et al, 2020 ) and histology, identified a much thicker tunica media (TM) in the umbilical artery than in the vein, with a visibly different structure ( Figure 1a–c , Figure 1—figure supplement 1a–c , Figure 1—videos 1 , 2 ). Most umbilical arteries were occluded at birth independent of delivery method or cord region analyzed, whereas umbilical veins remained patent ( Figure 1b , Figure 1—figure supplement 1b ).…”

Nichtneoplastische Lungenerkrankungen des Säuglings und Kindesalters

“…Abb. 5 [27,28]. Kongenitale Fehlbildungen von Herz, Niere oder Gastrointestinaltrakt sind zusätzlich in über 50 % der Fälle zu beobachten [26].…”

3D virtual histology of human pancreatic tissue by multiscale phase-contrast X-ray tomography

“…Since previous virtual histology applications at synchrotron as well as at laboratory setups were largely limited to smallanimal models (Albers et al, 2018;Busse et al, 2018;Dejea et al, 2019) or to post mortem human tissue (Tö pperwien et al, 2018;Buscema et al, 2019;Vå gberg et al, 2018;Garcia-Canadilla et al, 2018), the extension of the imaging technique to the 3D assessment of clinical biopsies (Norvik et al, 2020;Katsamenis et al, 2019) is now particular timely. Beyond research of tumor patho-physiology, the technique may even be applied in future in a clinical context with potential impact on the diagnosis of and on clinical treatment decisions.…”