Medical imaging technology plays an important role of creating internal images of the human body for clinical or medical purposes. Historically, this technology was born in November 1895 when Wilhelm Roentgen discovered electromagnetic radiation (x-ray) (Levine, 2010). Medical imaging technique can be defined as a technique which each modality could provide unique details of the human body function. The discovery of x-ray was a motivation reason for others to improve various technologies in medical imaging over the past years such as computed tomography (CT), ultrasound and magnetic resonance imaging (MRI). Ultrasound is one of the medical imaging technologies that are known as sound waves with a frequency above 20 KHz that excess the human hearing range using non-ionizing radiation. Ultrasound is a diagnostic modality technique that has been in clinical use over the past 40 years when Theodore Dussik and his brother Friederich in 1940s attempted to diagnose brain tumours using ultrasound waves, although their incredible work achieved success in 1970s. The aim of this study is to test the hypothesis that the minimum ultrasound transit time above noise (derived from the transit time spectrum) through cancellous bone may predict the velocity measurement. Therefore, deconvolution method has been used to predict ultrasound transit time through cancellous bone and then compare it to the reported transit time from clinical ultrasound bone densitometer (CUBA).
Table of Contents
1. Introduction
1.1 Overview
2. Background
2.1 The Nature of Ultrasound
2.2 Production of Ultrasound
2.3 Ultrasound Measurement Techniques
2.4 Ultrasound Interactions with Tissue
2.4.1 Attenuation
2.4.2 Reflection
2.4.3 Scattering
2.4.4 Refraction
2.4.5 Absorption
2.5 Ultrasonic Wave Propagating In Bone
2.6 Osteoporosis in Cancellous Bone
2.7 Methods of Determining Osteoporosis
2.8 Ultrasound Densitometry
3. Previous Studies
Research Objectives and Themes
The primary aim of this study is to investigate the hypothesis that the minimum ultrasound transit time above noise, as derived from the transit time spectrum, can reliably predict velocity measurements in cancellous bone. The research utilizes deconvolution methods to analyze ultrasound propagation and compares these findings with data from clinical ultrasound bone densitometers (CUBA).
- Mechanisms of ultrasound propagation in cancellous bone
- Methodologies for assessing bone density and osteoporosis risk
- Comparison of clinical ultrasound densitometry systems
- Deconvolution techniques for transit time spectrum analysis
- Relationship between acoustic parameters and bone structure
Excerpt from the Book
The Nature of Ultrasound
Ultrasound is a sound or pressure wave that has a frequency of more than 20 KHz; this frequency is higher than the one detected by the human ear (Bertora, 2007). Ordinarily, ultrasound propagates as longitude waves through fluid, air and human tissue due to the changes in pressure with slow speed of propagating in all materials such as soft tissue; about 1540 m/s. The number of cycles or pressure changes in 1 second, known as the frequency of ultrasound, can be determined by the sound source only. It cannot be determined by the medium of the travelling sound, and the range of frequencies used in clinical procedures is between 2 to 10 MHz. The speed of sound waves that travel through a medium can be determined by the density and stiffness of that medium as it is demonstrated in figure 1. The changes in either density or stiffness will affect the pulse transit time where pulsed beams are used in clinical procedures to achieve the required resolution (Aldrich, 2007).
Summary of Chapters
1. Introduction: This chapter provides a historical context for medical imaging and outlines the study's objective to validate a deconvolution method for predicting ultrasound transit time in cancellous bone.
2. Background: This chapter details the physical principles of ultrasound, including its interaction with tissue, production methods, and its specific application in assessing bone density and osteoporosis.
3. Previous Studies: This chapter reviews historical and contemporary research regarding the use of ultrasound densitometry and theoretical models, such as Biot’s theory, for analyzing cancellous bone properties.
Keywords
Ultrasound, Cancellous Bone, Osteoporosis, Bone Mineral Density, Transducer, Transit Time, Attenuation, Deconvolution, Velocity, Densitometry, Acoustic Impedance, Bone Fracture Risk, Medical Imaging
Frequently Asked Questions
What is the core subject of this research?
The research focuses on the application of ultrasound technology to assess cancellous bone properties and evaluate the risk of osteoporosis.
What are the central thematic fields addressed in this work?
The work covers ultrasound physics, diagnostic medical imaging, bone densitometry techniques, and the mechanical interaction of sound waves with porous structures like bone.
What is the primary objective of this study?
The study aims to test if the minimum ultrasound transit time above noise can successfully predict velocity measurements, serving as a non-invasive diagnostic tool.
Which scientific methodology is primarily employed?
The study uses a deconvolution method to analyze the transit time spectrum of ultrasound waves propagating through cancellous bone phantoms.
What topics are discussed in the main body?
The main body covers the nature and production of ultrasound, interaction mechanisms with human tissue (such as reflection and scattering), and specific densitometry methods like CUBA, DEXA, and QCT.
Which keywords best characterize this work?
Key terms include Ultrasound, Cancellous Bone, Osteoporosis, Bone Mineral Density, and Deconvolution.
Why is the calcaneus bone favored for ultrasound measurements?
The calcaneus is preferred because it has a relatively flat surface for transducer contact, consists of approximately 90% trabecular bone, and contains minimal overlying soft tissue that could attenuate the signal.
How does the CUBA system function for bone assessment?
The CUBA system is a portable device that utilizes automatic transducers to measure time of flight (transit time) and broadband ultrasound attenuation (BUA) to assess bone structure and fracture risk.
What differentiates QUS from other imaging methods like DEXA?
Quantitative Ultrasound (QUS) is non-invasive, radiation-free, and significantly less expensive than X-ray based techniques like DEXA or QCT.
- Arbeit zitieren
- Patrick Kimuyu (Autor:in), 2018, Comparison of Velocity and Ultrasound Transit Time Spectroscopy in Cancellous Bone Phantom, München, GRIN Verlag, https://www.grin.com/document/388407
