There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

The analysis of medical images has been woven into the fabric of the pattern analysis and machine intelligence (PAMI) community since the earliest days of these Transactions. Initially, the efforts in this area were seen as applying pattern analysis and computer vision techniques to another interesting dataset. However, over the last two to three decades, the unique nature of the problems presented within this area of study have led to the development of a new discipline in its own right. Examples of these include: the types of image information that are acquired, the fully three-dimensional image data, the nonrigid nature of object motion and deformation, and the statistical variation of both the underlying normal and abnormal ground truth. In this paper, we look at progress in the field over the last 20 years and suggest some of the challenges that remain for the years to come.

https://hal.inria.fr/inria-00615100/document

Medical image analysis: progress over two decades and the challenges ahead

The Society for Vascular Surgery practice guidelines on the care of patients with an abdominal aortic aneurysm

https://www.lfb.lv/files/ESVS-AAA-guidelines.pdf

Management of abdominal aortic aneurysms clinical practice guidelines of the European society for vascular surgery.

Magnetic resonance elastography: Non-invasive mapping of tissue elasticity

A nonlinear inversion scheme formulated on small subzones of the total region of interest (ROI) is developed. The algorithm reconstructs the distribution of a linear elastic stiffness term and a Maxwellian damping parameter over the entire ROI through a least squares optimization. The subzones are generated in a hierarchical manner based on progressive error minimization and processed in an automated, sweeping fashion until certain performance criterion are met. Simulation results show that the algorithm works well to minimize global error and is capable of simultaneously reconstructing both property parameter distributions even in the presence of random noise, although initial experience suggests that the elastic property image is superior to its attenuation coefficient counterpart.

Subzone-based nonlinear inversion scheme for viscoelastic tissue properties

Abdominal Aortic Aneurysms (AAAs) are localized enlargements of the aorta. If untreated, AAAs will grow irreversibly until rupture occurs. Ruptured AAAs are usually fatal and are a leading cause of death in the United States, killing 15,000 per year (National Center for Health Statistics, 2001). Surgery to repair AAAs also carries mortality risks, so surgeons desire a reliable tool to evaluate the risk of rupture versus the risk of surgery.Copyright © 2003 by ASME

Inflation Testing as a Means of Measuring Failure Strength of Aortic Tissue

Backside wear in the form of scratching and pitting observed on a series of mobile bearing rotating platform knee retrievals (n = 100) appears to be indicative of third body wear. The appearance of scratching and pitting on the backside does not correlate with duration in vivo or with linear backside wear measurements, but there is a weak correlation with fixation method indicating that some of the third body debris may be bone cement. Tribological tests representing rotation and fretting in the knee were run with bone cement, bone chips, and metal porous coating beads placed as third bodies in the contact. Results with bone cement show scratches similar to those found on retrievals.Copyright © 2005 by ASME

In-Vitro Study of Backside Wear Mechanism on Mobile Knee Bearing Components

Implementing constitutive relations that accurately describe the mechanical behavior of biological tissues in vivo
is integral to the success of any model-based elastographic reconstruction technique, and the diagnostic value of
the recovered images. Recently, poroelastic theory has been used to model tissue and other materials comprised
of two distinct phases. Current linearly elastic techniques are not capable of fully describing the complex
mechanical behavior of fluid-saturated tissues because they consider only a single solid phase, neglecting the
influence of extracellular fluid. In an attempt to model the deformation of biological tissues more effectively
in vivo by employing constitutive relations which are more representative of tissue structure and physiology,
a three-dimensional (3D) finite element reconstruction algorithm has been developed based on the equations
of dynamic poroelasticity. The algorithm operates on a single domain of O(10 3 ) nodes. The performance of
the algorithm was tested using simulated data. The results suggest that the technique is capable of recovering
accurate distributions of the underlying mechanical properties of the solid matrix as well as the time-harmonic
pressure field resulting from tissue vibration.

Assesing the feasibility for a poroelastic reconstruction algorithm in MR elastography

Introduction The ASME Research Committee on Tribology (RCT) has been concerned that some of today's engineering students may not be learning enough about the fundamentals of tribology. After considerable discussion of the topic by RCT membership, it was decided to commission a survey of engineering curricula in the United States to gather data on the present status of tribology education. The survey was followed by a panel discussion which evaluated the significance of the survey results and obtained further input from educators, researchers and practicing engineers representing a broad spectrum of views in different sectors of academia, industry and federal government. This panel session was held at the Joint ASME/STLE Tribology Conference in 1987. Included in the panel and the subsequent discussions were representatives from other countries; their input was important in incorporating the experience and the views on the tribology education. The panel consisted of the following distinguished tribologists: Professor E. E. Klaus, Pennsylvania State University; Professor W. O. Winer, Georgia Institute of Technology; Dr. N. P. Suh, National Science Foundation; A. O. Dehart, General Motors Research; T. A. Harris, MRC Bearings, K. J. Brown, Ontario Hydro; and Professor C. M. Taylor, the University of Leeds.

/pdf/tribology-education-present-status-and-future-challenges-317nw70k3x.pdf

Francis E. Kennedy

Papers

Subzone-based nonlinear inversion scheme for viscoelastic tissue properties

Inflation Testing as a Means of Measuring Failure Strength of Aortic Tissue

In-Vitro Study of Backside Wear Mechanism on Mobile Knee Bearing Components

Assesing the feasibility for a poroelastic reconstruction algorithm in MR elastography

Tribology Education: Present Status and Future Challenges