Segmentation of Blood Vessels Using Magnetic Resonance Angiography Images

Author(s):  
Ahmed Shalaby ◽  
Ali Mahmoud ◽  
Mohammed Ghazal ◽  
Jasjit S. Suri ◽  
Ayman El-Baz
Author(s):  
Ahmed Shalaby ◽  
Ali Mahmoud ◽  
Samineh Mesbah ◽  
Maryam El-Baz ◽  
Jasjit S. Suri ◽  
...  

2008 ◽  
Vol 178 (1) ◽  
pp. 130-132 ◽  
Author(s):  
Samuel Contreras ◽  
José María Vázquez ◽  
Ana De Miguel ◽  
Manuel Morales ◽  
Francisco Gil ◽  
...  

2017 ◽  
Vol 5 (3) ◽  
Author(s):  
Ayman El-baz ◽  
Ahmed Shalaby ◽  
Fatma Taher ◽  
Maryam El-Baz ◽  
Mohammed Ghazal ◽  
...  

2008 ◽  
Vol 36 (02) ◽  
pp. 1-12 ◽  
Author(s):  
A. Brühschwein ◽  
K. Rieden ◽  
U. Matis ◽  
I. Foltin

SummaryMagnetic resonance angiography (MRA) is a non-invasive imaging technique for visualising blood vessels and blood flow. The first half of this article is a literature review of the three basic MRA techniques: Timeof-flight (TOF) angiography, phase-contrast angiography and contrast-enhanced angiography. Physical principles, technical requirements, investigated parameters, advantages and disadvantages of the methods, and the correlation between application of contrast medium and time of examination are discussed. Subsequent processing of the MR images using “maximum intensity projection“ (MIP) provided a threedimensional image of the vascular architecture and improved the anatomical orientation; however, MIP was shown to sometimes cause additional diagnostic pitfalls. Therefore, the original slices should always be consulted in addition to the MIP. The second half of this article describes the application of the different MRA methods in veterinary medicine and compares the results with MRA in human medicine. A total of 15 dogs with clinical signs that warranted further work-up using MRA, and 20 human patients requiring MRA, were included in the study. Five healthy dogs served as controls. The vascular architecture in dogs was compared with that in human patients, and the images were scrutinized for lesions that corresponded to the clinical signs. An abnormal vascular architecture was identified in eight dogs with a portosystemic shunt, which allowed targeted surgical intervention. Aneurysms, thrombi and stenoses were seen in images from human patients. Comparison of the vascular architecture in humans and dogs allowed the anatomic identification and evaluation of the visualised blood vessels in the dog. Magnetic resonance imaging is still a relatively new technique in veterinary medicine and appears to be a promising diagnostic tool for a number of disorders as the availability of high-field MRI in veterinary clinics increases.


2010 ◽  
Vol 31 (2) ◽  
pp. 290-300 ◽  
Author(s):  
Elizabeth Bullitt ◽  
Donglin Zeng ◽  
Benedicte Mortamet ◽  
Arpita Ghosh ◽  
Stephen R. Aylward ◽  
...  

VASA ◽  
2005 ◽  
Vol 34 (3) ◽  
pp. 181-185 ◽  
Author(s):  
Westhoff-Bleck ◽  
Meyer ◽  
Lotz ◽  
Tutarel ◽  
Weiss ◽  
...  

Background: The presence of a bicuspid aortic valve (BAV) might be associated with a progressive dilatation of the aortic root and ascending aorta. However, involvement of the aortic arch and descending aorta has not yet been elucidated. Patients and methods: Magnetic resonance angiography (MRA) was used to assess the diameter of the ascending aorta, aortic arch, and descending aorta in 28 patients with bicuspid aortic valves (mean age 30 ± 9 years). Results: Patients with BAV, but without significant aortic stenosis or regurgitation (n = 10, mean age 27 ± 8 years, n.s. versus control) were compared with controls (n = 13, mean age 33 ± 10 years). In the BAV-patients, aortic root diameter was 35.1 ± 4.9 mm versus 28.9 ± 4.8 mm in the control group (p < 0.01). The diameter of the ascending aorta was also significantly increased at the level of the pulmonary artery (35.5 ± 5.6 mm versus 27.0 ± 4.8 mm, p < 0.001). BAV-patients with moderate or severe aortic regurgitation (n = 18, mean age 32 ± 9 years, n.s. versus control) had a significant dilatation of the aortic root, ascending aorta at the level of the pulmonary artery (41.7 ± 4.8 mm versus 27.0 ± 4.8 mm in control patients, p < 0.001) and, furthermore, significantly increased diameters of the aortic arch (27.1 ± 5.6 mm versus 21.5 ± 1.8 mm, p < 0.01) and descending aorta (21.8 ± 5.6 mm versus 17.0 ± 5.6 mm, p < 0.01). Conclusions: The whole thoracic aorta is abnormally dilated in patients with BAV, particularly in patients with moderate/severe aortic regurgitation. The maximum dilatation occurs in the ascending aorta at the level of the pulmonary artery. Thus, we suggest evaluation of the entire thoracic aorta in patients with BAV.


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