High-Resolution Magnetic Resonance Imaging: Three-Dimensional Trabecular Bone Architecture and Biomechanical Properties

Bone ◽  
1998 ◽  
Vol 22 (5) ◽  
pp. 445-454 ◽  
Author(s):  
S. Majumdar ◽  
M. Kothari ◽  
P. Augat ◽  
D.C. Newitt ◽  
T.M. Link ◽  
...  
2020 ◽  
Author(s):  
Jinmei Zheng ◽  
Bin Sun ◽  
Ruolan Lin ◽  
Yongqi Teng ◽  
Xihai Zhao ◽  
...  

Abstract Background Atherosclerotic plaques are often present in regions with complicated flow patterns. Vascular morphology plays a role in hemodynamics. In this study, we investigate the relationship between the geometry of the vertebrobasilar artery system and the basilar artery (BA) plaque prevalence.Methods We enrolled 290 patients with posterior circulation ischemic stroke. We distinguished four configurations of the vertebrobasilar artery: Walking, Tuning Fork, Lambda, and No Confluence. The diameter of the vertebral artery (VA) and the number of bends in the intracranial VA segment was assessed using three-dimensional time-of-flight magnetic resonance angiography. We differentiated between multi-bending (≥ 3 bends) and oligo-bending (< 3 bends) VAs. High-resolution magnetic resonance imaging was used to evaluate BA plaques. Logistic regression models examined the relationship between the geometry type and BA plaque prevalence.Results After adjusting for sex, age, body mass index ≥ 28, hypertension, and diabetes mellitus, the Walking, Lambda, and No Confluence geometries were associated with the presence of BA plaque. Patients with multi-bending VAs in both the Walking (71.43%, P = 0.003) and Lambda group (40.43%, P = 0.018) had more plaques compared to patients with oligo-bending VAs in these groups. In the Lambda group, the diameter difference between the VAs was larger in patients with BA plaques than that in patients without BA plaques (1.4 mm vs. 0.9 mm, P < 0.001).Conclusions The Walking, Lambda, and No Confluence geometry, ≥ 3 bends in the VAs, and a large diameter difference between the VAs were associated with the presence of BA plaque.


2005 ◽  
Vol 46 (3) ◽  
pp. 306-309 ◽  
Author(s):  
B. Ludescher ◽  
P. Martirosian ◽  
S. Lenk ◽  
J. Machann ◽  
F. Dammann ◽  
...  

Purpose: To evaluate the feasibility of high‐resolution magnetic resonance imaging (MRI) of trabecular bone of the wrist at 3 Tesla (3T) in vivo and to assess the potential benefit of the increased resolution for clinical assessment of structural changes in spongy bone. Material and Methods: High‐resolution MRI of the wrist was performed with a whole‐body 3T MR scanner using a dedicated circularly polarized transmit–receive wrist‐coil. Two 3D‐FISP sequences with a spatial resolution of 300×300×300 µm3 in a measuring time of TA = 7:51 min, and 200×200×200 µm3 in TA = 9:33 min were applied. Seven young healthy volunteers and three elderly subjects with suspected osteoporosis were examined. The signal‐to‐noise ratio (SNR) in the optimized setup at 3T was compared to measurements at 1.5T. Results: The images at 3T allow microscopic analysis of the bone structure at an isotropic spatial resolution of 200 µm in examination times of <10 min. Differences in the structure of the spongy bone between normal and markedly osteoporotic subjects are well depicted. The SNR at 3T was found up to 16 times higher than at 1.5T applying unchanged imaging parameters. Conclusion: The proposed high‐resolution MRI technique offers high potential in the diagnosis and follow‐up of diseases with impaired bone structure of hand and/or wrist in clinical applications.


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