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|Title: ||AN IMAGE PROCESSING APPROACH FOR CEPHALOMETRIC MEASUREMENTS|
|Authors: ||Mosleh, Mogeeb A.A|
|Keywords: ||Cephalometric system|
|Issue Date: ||2008 |
|Abstract: ||Computational tools for medical image analysis help clinicians diagnose, treat, monitor
changes, plan, and execute procedures more safely and effectively. Two fundamental
problems in analyzing medical imagery are image registration and image segmentation.
Analysis of Cephalometric x-ray and measurements of parameters based on detected
features play an important in monitoring the treatment. The analysis is based on location of
landmarks that form the basis of linear and angular measurements. Many systems had
developed to computerize cephalometric process but most of them didn't satisfy user
requirements in accurate, speed, and reliability.
In this dissertation a new system is developed to automate cephalometric analysis
and measurements using x-ray images. For cephalometric systems our study consists of
three main parts: filtering model, locating landmark model, and measurements model.
The use of filter on x-ray can increase cephalometric system accuracy. Radiographic
images contain many features. Some of them are easily distinguishable while others are
more robust when filter is considered. A particular method of defining Gaussian and
unsharb filters appropriate for x-ray images is used. The filters are adapted to the domain of
radiographic images. Two alternative approaches are implemented to provide suitable
filters for enhancing the x-ray images. These approaches use Gaussian filter and unsharb
filter to provide powerful tools for locating the important landmark points in x-ray image to
obtain better accuracy in cephalometric measurements.
A new system is developed for cephalometric analysis, measurements and locating
of landmark points. Constructions of landmark points are done by manual placement of a
number of nodes with respect to a registered x-ray image. Locations are chosen by
experienced dentist who selected the areas of distinctive appearance on images of different
skull. Eleven nodes are defined on the developed system. The nodes are very carefully
placed to ensure that their placement was at the intended point on the x-ray image. At each
node location, a set of (x,y) point of the coordinates are registered for measurement
purpose. Analysis and measurements processes are performed automatically, including 18
measurements of distance and degree for x-ray image.
Statistical analysis shows better accuracy for the developed cephalometric system
than manual methods. The testing results demonstrated that filter methods can indeed
provided a significant increase in accuracy for locating landmark points. This new system is
fast and superior in accuracy compared to the manual cephalometric methods. There is no
static difference between manual and automatic measurements. The experimental results
have demonstrated that the proposed method performs better than the existing methods in
terms of their identifiably, accuracy, speed, and dynamic range of images.
A prototype was developed with a Multi-Document Interface (MDI) application of
Microsoft Windows. Three modules were included.
• Manual landmarking module provides the function manual to locate the landmarks
on the screen through the interactive user interface.
• Filter module enhances the contrast of x-ray images.
• Measurements are done in the cephalometric analysis module.
The system has proved to be useful tool for orthodontists in the diagnosis and treatment of
|Description: ||Master of Software Engineering|
|Appears in Collections:||Masters Dissertations: Computer Science|