Proposition and Evaluation of a Novel Method Based on Videogrammetry to Measure Three-Dimensional Rib Motion during Breathing

2009 ◽  
Vol 25 (3) ◽  
pp. 247-252 ◽  
Author(s):  
Karine Jacon Sarro ◽  
Amanda Piaia Silvatti ◽  
Andrea Aliverti ◽  
Ricardo M. L. Barros
Keyword(s):  
Magnetic Resonance ◽  
Relative Motion ◽  
Kinematic Analysis ◽  
Healthy Subjects ◽  
Three Dimensional ◽  
Motion Artifact ◽  
Mean Value ◽  
Breathing Cycle ◽  
Angular Variation ◽  
Novel Method

A novel method based on kinematical analysis is proposed to describe the three-dimensional motion of the ribs during breathing. The three-dimensional coordinates of markers on the ribs and vertebrae were used to calculate the orientation of the ribs as a function of time. A test measured the relative motion between the markers and the ribs using magnetic resonance and the results revealed that the skin motion artifact found for the ribs (absolute mean value 3.9 mm) would induce maximum errors of 4° on rib motion calculation. The method identified a signal coherent with the breathing cycle for the angles of the ribs around the mediolateral axis and was also able to show differences between healthy nonathletes and swimmers, which presented greater angular variation of the ribs (p < .05). In conclusion, this study has shown the reliability of using three-dimensional kinematic analysis to evaluate the movement of the ribs during breathing as well as its potential to identify differences in the behavior of the rib motion in trained swimmers and untrained healthy subjects.

scholarly journals Vascular phenotyping of brain tumors using magnetic resonance microscopy (μMRI)

2011 ◽  
Vol 31 (7) ◽  
pp. 1623-1636 ◽  
Author(s):  
Eugene Kim ◽  
Jiangyang Zhang ◽  
Karen Hong ◽  
Nicole E Benoit ◽  
Arvind P Pathak
Keyword(s):  
Brain Tumor ◽  
Magnetic Resonance ◽  
Brain Tumors ◽  
Three Dimensional ◽  
Region Of Interest ◽  
Tumor Model ◽  
Magnetic Resonance Microscopy ◽  
Vascular Phenotype ◽  
Brain Tumor Model ◽  
Novel Method

Abnormal vascular phenotypes have been implicated in neuropathologies ranging from Alzheimer's disease to brain tumors. The development of transgenic mouse models of such diseases has created a crucial need for characterizing the murine neurovasculature. Although histologic techniques are excellent for imaging the microvasculature at submicron resolutions, they offer only limited coverage. It is also challenging to reconstruct the three-dimensional (3D) vasculature and other structures, such as white matter tracts, after tissue sectioning. Here, we describe a novel method for 3D whole-brain mapping of the murine vasculature using magnetic resonance microscopy (μMRI), and its application to a preclinical brain tumor model. The 3D vascular architecture was characterized by six morphologic parameters: vessel length, vessel radius, microvessel density, length per unit volume, fractional blood volume, and tortuosity. Region-of-interest analysis showed significant differences in the vascular phenotype between the tumor and the contralateral brain, as well as between postinoculation day 12 and day 17 tumors. These results unequivocally show the feasibility of using μMRI to characterize the vascular phenotype of brain tumors. Finally, we show that combining these vascular data with coregistered images acquired with diffusion-weighted MRI provides a new tool for investigating the relationship between angiogenesis and concomitant changes in the brain tumor microenvironment.

scholarly journals Preoperative perihilar cholangiocarcinoma assessment using virtual endoscopic imaging magnetic resonance cholangioscopy

2021 ◽  
Vol 09 (07) ◽  
pp. E1158-E1163
Author(s):  
Mitsuru Okuno ◽  
Tsuyoshi Mukai ◽  
Shota Iwata ◽  
Ryuichi Tezuka ◽  
Naoya Mita ◽  
...  
Keyword(s):  
Bile Duct ◽  
Magnetic Resonance ◽  
Three Dimensional ◽  
Preoperative Assessment ◽  
Perihilar Cholangiocarcinoma ◽  
Imaging Method ◽  
Endoscopic Imaging ◽  
Novel Method ◽  
Magnetic Resonance Imaging Mri ◽  
Pass Through

Abstract Background and study aims Preoperative assessment of the superficial ductal spread (SDS) of perihilar cholangiocarcinoma (PCCA) is important for determining its resectability. A virtual endoscopic imaging method, magnetic resonance cholangioscopy (MRCS), wherein a three-dimensional image is created from magnetic resonance imaging (MRI) data, can evaluate all aspects of arbitrary bile ducts. Patients and methods Overall, 15 patients with PCCA who underwent preoperative MRI were enrolled. All patients underwent surgical treatment. Results MRCS could be performed based on preoperative MRI data in all patients. MRCS could not be used in one patient due to debris in the obstructed bile duct. The remaining 14 patients (93 %) were diagnosed with obstructed bile duct or irregular surface of the bile duct, signifying tumor invasion. The accuracy rate of diagnosing the SDS was 93 % (14/15). Seven patients underwent preoperative peroral cholangioscopy; the scope could not pass through the tumor in three patients. In these three patients, MRCS was able to be use dtoevaluate the obstructed side of the bile duct and faciliated accurate diagnosis of SDS. Conclusions MRCS can be used to noninvasively evaluate the bile duct in all directions. This novel method makes it easy to create virtual images and can be useful for diagnosing the preoperative SDS of PCCA.

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