Automatic Lumbar Vertebrae Segmentation in Fluoroscopic Images via Optimised Concurrent Hough Transform

Low back pain is a very common problem in the industrialised countries and its associated cost is enormous. Diagnosis of the underlying causes can be extremely difficult. Many studies have focused on mechanical disorders of the spine. Digital videofluoroscopy (DVF) was widely used to obtain images for motion studies. This can provide motion sequences of the lumbar spine, but the images obtained often suffer due to noise, exacerbated by the very low radiation dosage. Thus determining vertebrae position within the image sequence presents a considerable challenge. In this paper, we show how our new approach can automatically detect the positions and borders of vertebrae concurrently, relieving many of the problems experienced in other approaches. First, we use phase congruency to relieve difficulty associated with threshold selection in edge detection of the illumination variant DVF images. Then, our new Hough transform approach is applied to determine the moving vertebrae, concurrently. We include optimisation via a genetic algorithm as without it the extraction of moving multiple vertebrae is computationally daunting. Our results show that this new approach can indeed provide extractions of position and rotation which appear to be of sufficient quality to aid therapy and diagnosis of spinal disorders

Lumbar Spine Location in Fluoroscopic Images by Evidence Gathering

Low back pain (LBP) is a very common problem and lumbar segmental instability is one of the causes. It is important to investigate lumbar spine movement in order to understand instability better and as an aid to diagnosis. Digital videofluoroscopy provides a method of quantifying the motion of individual vertebrae, but due to the relatively poor image quality, it is difficult and time consuming to locate landmarks manually, from which the kinematics can be calculated. Some semi-automatic approaches have already been developed but these are still time consuming and require some manual interaction. In this paper we apply the Hough transform (HT) to locate the lumbar spinal segments automatically. The HT is a powerful tool in computer vision and it has good performance in noise and partial occlusion. A recent arbitrary shape representation avoids problems inherent with tabular representations in the generalised HT (GHT) by describing shapes using a continuous formulation. The target shape is described by a set of Fourier descriptors, which vote in an accumulator space from which the object parameters of translation (including the x and y direction), rotation and scale can be determined. At present, this algorithm has been applied to the images of lumbar spine, and has been shown to provide satisfactory results. Further work will concentrate on reducing the computational time for real-time application, and on approaches to refine information at the apices, given initialisation by the new HT method

Neighborhood information and home mortgage lending.

An examination of how information about a neighborhood affects the level of lending activity in it--specifically, whether lenders deny mortgage applications at higher rates in neighborhoods where they have little experience in evaluating applications and/or where the lending community in general lacks such experience.Mortgages ; Discrimination in mortgage loans

Cross-lender variation in home mortgage lending

A lender-specific analysis of differences in minority and low-income mortgage loan originations using new applicant-level data gathered under the Home Mortgage Disclosure Act of 1975.Home Mortgage Disclosure Act ; Mortgages ; Discrimination in mortgage loans

Home mortgage lending by the numbers

A look at some of the issues associated with reports that minority applicants for home mortgage loans are far more likely than whites to be denied credit. The authors raise the concern that simple comparisons of denial rates are not sufficient for grasping the complexities surrounding community-oriented lending.Mortgages ; Community Reinvestment Act of 1977 ; Home Mortgage Disclosure Act

Lender consistency in housing credit markets

An examination of how and why individual financial institutions vary in their propensity to attract and approve mortgage applications from minorities, using Home Mortgage Disclosure Act data.Mortgages ; Housing - Finance ; Home Mortgage Disclosure Act