Rapid Three-Dimensional Segmentation of the Carotid Bifurcation From Serial MR Images

1999 ◽  
Vol 122 (1) ◽  
pp. 96-99 ◽  
Author(s):  
H. M. Ladak ◽  
J. S. Milner and ◽  
D. A. Steinman

The current trend in computational hemodynamics is to employ realistic models derived from ex vivo or in vivo imaging. Such studies typically produce a series of images from which the lumen boundaries must first be individually extracted (i.e., two-dimensional segmentation), and then serially reconstructed to produce the three-dimensional lumen surface geometry. In this paper, we present a rapid three-dimensional segmentation technique that combines these two steps, based on the idea of an expanding virtual balloon. This three-dimensional technique is demonstrated in application to finite element meshing and CFD modeling of flow in the carotid bifurcation of a normal volunteer imaged with black blood MRI. Wall shear stress patterns computed using a mesh generated with the three-dimensional technique agree well with those computed using a mesh generated from conventional two-dimensional segmentation and serial reconstruction. In addition to reducing the time required to extract the lumen surface from hours to minutes, our approach is easy to learn and use and requires minimal user intervention, which can potentially increase the accuracy and precision of quantitative and longitudinal studies of hemodynamics and vascular disease. [S0148-0731(00)00201-6]

2021 ◽  
Vol 3 (3) ◽  
pp. e200103
Author(s):  
Stephanie J. Blocker ◽  
James Cook ◽  
Yvonne M. Mowery ◽  
Jeffrey I. Everitt ◽  
Yi Qi ◽  
...  

2012 ◽  
Vol 9 (77) ◽  
pp. 3288-3302 ◽  
Author(s):  
Neha Arya ◽  
Viren Sardana ◽  
Meera Saxena ◽  
Annapoorni Rangarajan ◽  
Dhirendra S. Katti

Owing to the reduced co-relationship between conventional flat Petri dish culture (two-dimensional) and the tumour microenvironment, there has been a shift towards three-dimensional culture systems that show an improved analogy to the same. In this work, an extracellular matrix (ECM)-mimicking three-dimensional scaffold based on chitosan and gelatin was fabricated and explored for its potential as a tumour model for lung cancer. It was demonstrated that the chitosan–gelatin (CG) scaffolds supported the formation of tumoroids that were similar to tumours grown in vivo for factors involved in tumour-cell–ECM interaction, invasion and metastasis, and response to anti-cancer drugs. On the other hand, the two-dimensional Petri dish surfaces did not demonstrate gene-expression profiles similar to tumours grown in vivo . Further, the three-dimensional CG scaffolds supported the formation of tumoroids, using other types of cancer cells such as breast, cervix and bone, indicating a possible wider potential for in vitro tumoroid generation. Overall, the results demonstrated that CG scaffolds can be an improved in vitro tool to study cancer progression and drug screening for solid tumours.


2003 ◽  
Vol 30 (5) ◽  
pp. 887-897 ◽  
Author(s):  
Yunqiu Wang ◽  
H. Neale Cardinal ◽  
Donal B. Downey ◽  
Aaron Fenster

2020 ◽  
Vol 13 (02) ◽  
pp. 2050007
Author(s):  
Joanne Li ◽  
Madison N. Wilson ◽  
Andrew J. Bower ◽  
Marina Marjanovic ◽  
Eric J. Chaney ◽  
...  

To date, numerous studies have been performed to elucidate the complex cellular dynamics in skin diseases, but few have attempted to characterize these cellular events under conditions similar to the native environment. To address this challenge, a three-dimensional (3D) multimodal analysis platform was developed for characterizing in vivo cellular dynamics in skin, which was then utilized to process in vivo wound healing data to demonstrate its applicability. Special attention is focused on in vivo biological parameters that are difficult to study with ex vivo analysis, including 3D cell tracking and techniques to connect biological information obtained from different imaging modalities. These results here open new possibilities for evaluating 3D cellular dynamics in vivo, and can potentially provide new tools for characterizing the skin microenvironment and pathologies in the future.


Author(s):  
Hemanga K. Bhattacharjee ◽  
Shafneed Chaliyadan ◽  
Ashwani K. Mishra ◽  
Harshit Agarwal ◽  
Suhani Suhani ◽  
...  

Reproduction ◽  
2003 ◽  
pp. 259-270 ◽  
Author(s):  
DM Woolley

The hydrodynamic basis for the accumulation of spermatozoa at surfaces has been investigated. The general conclusion is that when spermatozoa arrive at a surface, they will remain there if the vector of the time-averaged thrust is directed towards that surface. This can arise in two basic ways. First, consider spermatozoa that maintain a three-dimensional waveform and roll (spin) as they progress: in this case, it is argued that the conical (rather than cylindrical) shape of the flagellar envelope will establish the direction-of-thrust necessary for capture by the surface. (Additional findings, for spermatozoa of this type, are that the swim-trajectory is curved and that the direction of its curvature reveals the roll-direction of the cell.) Second, consider spermatozoa that maintain a strictly two-dimensional waveform at the surface: in this case, spermatozoa can be captured because the plane-of-flattening of the sperm head is tilted slightly relative to the plane of the flagellar beat. The sperm head is acting as a hydrofoil and, in one orientation only, it comes to exert a pressure against the surface. (This pressure may possibly, in vivo, aid the penetration of the zona pellucida.) The hydrofoil action of sperm heads may explain any bias in the circling direction of spermatozoa that execute two-dimensional waves at surfaces. Finally, a more complex phenomenon is where interaction of the spermatozoa with the surface appears to induce a three-dimensional to two-dimensional conversion of the flagellar wave (thus permitting the hydrofoil effect described). This is characteristic of sperm with 'twisted planar' rather than helical waves. In mammalian spermatozoa, approximately half the beat cycle is planar and the other half generates a pattern of torque causing the head to roll clockwise (seen from ahead), producing a torsion of the neck region of the flagellum. It is the gradual suppression of this torsion, by either impedance at the solid boundary or by raised viscosity, that converts the 'twisted planar' shape into a planar wave.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e19015-e19015
Author(s):  
Amr M. Morsi ◽  
Avital Gazial-Sovran ◽  
Hana Baig ◽  
Robert S. Kerbel ◽  
John Golfinos ◽  
...  

e19015 Background: 75% of patients with metastatic melanoma develop brain metastases (B-mets). Such patients show dismal prognosis with a median survival of < 6 months. Scarcity of clinically relevant in vivo models has hindered melanoma B-met studies. We compared the in vivo dissemination upon ultrasound (u/s) guided intracardiac injection of B16F10 cells to 131/4-5B1 (hereafter 5B1), a WM239A subclone with enhanced brain tropism. We also implemented an ex vivo MRI protocol as a high throughput three dimensional approach for characterizing B-mets penetrance and growth. Methods: B16-F10 or 5B1 melanoma cells were injected in C57BL/6J mice (n=40) or athymic/nude mice (n=40) respectively using u/s-guided intracardiac injection. Upon weight loss, mice were euthanized, and heads prepared for ex vivo imaging. All µMRI experiments were performed with a 7T Bruker Avance II console. The protocol consisted of (110-mm)3 isotropic T1-, T2- and T2*-weighted sequences. Results: Our ex vivo MRI recapitulates the clinical radiological T1 and T2 brightening as well as susceptibility-induced T2* darkening effect of melanoma. The B16F10 model revealed exclusive ventricular and leptomeningeal spread while the 5B1 model showed parenchymal lesions. In addition, 90% of the 5B1 mice with brain tumors showed multiple lesions (3-16) vs. 18% in the B16F10 model (1- 3). Finally, 3D volume studies revealed a higher B-met penetrance (68% vs. 18%), delayed onset of tumor detection (earliest-day 27 vs. day 15) post-injection and a slower growth rate of 5B1 brain metastases compared to B16F10 tumors. Conclusions: Our results suggest that u/s-guided intracardiac injection of melanoma cells is an optimal method to capture the cells’ spontaneous dissemination pattern (or site-specific tropism) and that the 5B1 model is a more clinically relevant model of melanoma B-met for preclinical studies.


1995 ◽  
Vol 107 (1) ◽  
pp. 10-18 ◽  
Author(s):  
A. Ziegler ◽  
M. Izquierdo ◽  
C. Remy ◽  
M. Decorps

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