Medical imagining
Prepared by:
Marium ramadan
Submitted to:
Dr/Mohamed Hisham
Medical imaging is the method and process that used to create
images of the human body; they play a pivotal role in selecting and
implementing the most appropriate examination protocols which
will answer the clinical question.
There are many types of medical imaging; we will be interested in
one type of them which is ultrasound.
Ultrasound
Definition
It is High-frequency sound waves. Ultrasound waves can be bounced
off of tissues using special devices. The
echoes are then converted into a picture
called a sonogram. Ultrasound imaging,
referred to as ultrasonography, allows
physicians and patients to get an inside
view of soft tissues and body cavities,
without using invasive techniques.
Theory of operation
Ultrasound imaging first, send ultrasound
waves, then hears echoes, finally interprets
these echoes into images. Ultrasonography
uses a probe has many transducers to send
pulses of sound into the body.
The transducer measure the difference in
time between the transmitted one and the
echo that’s used to calculate the depth of
the tissue which reflects the wave. The greater the acoustic
impedances difference, the larger echo is.
‫يعد التصوير الطبى من التطبيقات الحديثة التى تستخدم فى تشخيص االمراض وتحديد‬
‫نوعها حيث انه هو العملية التى تقوم بتصوير جسم االنسان من الداخل يمكن للطبيب من‬
.‫خاللها تشخيص االمراض‬
‫وهناك انواع عديدة من التصوير الطبى وسوف نتعرض لدراسة التصوير عن طريق‬
‫ وهى عبارة عن امواج ذات تردد عالى والتى تسقط على الجسم‬,‫الموجات فوق الصوتية‬
‫المراد تصويرة ثم تنعكس فى صورة صدى يمكن من خالل معرفة سرعتة والوقت الذى‬
‫استغرقة للرجوع مرة اخرى للجهاز المنبعث منه من تكوين صورة واضحة لجسم‬
‫االنسان من الداخل دون الحاجة الى الدخول بمنظار طبى الى داخل جسم االنسان‬
‫يتم التصوير بالموجات الفوق الصوتية عن طريق جهاز باعث للموجات يقوم بارسالها‬
.‫واستقبالها ايضا ويتم حساب الوقت بين ارسال االشعة واستقبالها‬
Clinical uses of ultrasound imaging
Ultrasound is used in clinical use in both applications, diagnosis and
therapeutic.
Diagnosis
 Cardiology: to diagnose e.g. dilatation of parts of the heart and
function of heart ventricles and valves.
 Neurology: for assessing blood flow and stenoses in the
carotid arterie and big intracerebral arteries.
 Cardiovascular system: To assess patency and possible
obstruction of arteries and determine extent and severity of
venous insufficiency (venosonography).
 Gastroenterology: In Abdomen sound waves are blocked by
gas in the bowel and attenuated in different degree by fat,
therefore there are limited diagnostic capabilities in this area
but the appendix can sometimes be seen when inflamed .
 Ophthalmology: provides data on the length of the eye, which
is a major determinant in common sight disorders and to
produce a two-dimensional, cross-sectional view of the eye and
the orbit. It is otherwise called brightness scan.
Therapeutic
In therapeutic application, ultrasound is used to bring heat or
agitation to the body so much higher energies are used than in
diagnosis ultrasound.
 Dental clinic in cleaning teeth.
 Generation of heat and mechanical changes in biological tissue,
e.g. in occupational therapy, physical therapy and cancer
treatment.
 Focused ultrasound to generate high localized heat to treat
cysts and tumors.
 Breaking up kidney stones.
 Stimulation of bone growth.
Standards applied to ultrasound imaging
There are many international standards applied to the ultra sonic
imaging devices we will introduce some of them
1-American National Standards Institute/Association
for the Advancement of Medical Instrumentation.
2-American Society for Testing and Materials. Specification
for medical and surgical suction and drainage
systems
3-American Society for Testing and Materials. Specification
for medical and surgical suction and drainage
systems
4-British Standards Institution. Specification for high
frequency surgical equipment
5-Canadian Standards Association. Reprocessing of reusable
medical and surgical supplies
What are the problems that face ultrasound imaging?
Some ultrasonic aspirator hand pieces need to be
disassembled for cleaning and routine maintenance.
Special accessories such as a torque wrench or hand piece
holder are typically required for proper disassembly
and reassembly.
Ultrasound machine is a complex medical system. So the main
problem for the repairer is the fault, and we will discuss some
common problems.
Appearance of noise in the screen: Check the transducer probe, if
noise changes continuously with rubbing the crystal surface that
means the Probe is damaged.
During rubbing surface of probe if noise is constant, that means that
the probe is fine.
Lines or gap appear on screen at specific region: it’s mean one or
more of the crystal of surface is damaged and probe has to be
replaced.
Error in sending image for printing: check the printer cable
connection on both sides, whether or not properly inserted, check the
I/O board of the CPU section of Ultrasound unit, Check whether the
power supplied to the board is enable or not, If all is right that’s mean
that one or more ICs may be damaged and has to be replaced.
Requirements to establish
There are many technologies used for implementation of ultrasound
like Shear wave elasticity imaging (SWEI) is a new approach for
imaging and characterizing tissue structures based on the use of
shear acoustic waves remotely induced by the radiation force of a
focused ultrasonic beam.
Also we need:
Electronic background
Available raw materials
Financial support from the ministry of industry
Global marketing
Developing scientific researches
The provision of international professors in this field
Human factors applied to ultra sound imaging
In the figure below this is the board that controlled by the technician
during the process of ultrasound. This board must be in line with the
human factors engineering laws.
The labels must be clear, suitable with using, put in a suitable place to be
ease to the technician to work and can’t be deleted with time or be
unclear.
Another consideration is that the ventilation of the room must be good as
the radiation must go out from the room
References
Links
 www.radiologyinfo.org/en/info.cfm?pg=genus
 www.en.wikipedia.org/wiki/Medical_ultrasonography
 http://searchsecurity.techtarget.com/definition/ultrasound
Pdfs
 Encyclopedia of Medical Devices and Instrumentations
 Medical Imaging Physics by Hendee & Ritenour
 Health Care product comparison system