1. Medical Imaging
Lecture 4

2. What is endoscopy?
Endoscopy (en-DAHS-kuh-pee) is a medical procedure done with an instrument called an endoscope (EN-duh-skop). The endoscope is put into the body to look inside, and is sometimes used for certain kinds of surgery.
Looking with an endoscope is different from using imaging tests, like x-rays and CT scans, which can get pictures of the inside the body without putting tools or devices into it.
There are many different kinds of endoscopes, or “scopes.” Most are lighted, and some have a small video camera on the end that puts pictures on a computer screen. Endoscopes are different lengths and shapes. Some are stiff, while others are flexible.
Depending on the area of the body being looked at, the endoscope may be put in the mouth, anus, or urethra. Sometimes, it’s put through a small incision (cut) made in the skin.

3. The endoscopy procedure
An endoscopy is not painful, although it may feel a little uncomfortable.
Endoscopies do not usually require general anaesthetic. However, you may be given a local anaesthetic, which is used to numb a specific area of body.
The endoscope will be carefully guided into the body. Exactly where it enters depend on what part of the body is being examined. Possible options include your: throat, anus, urethra etc. In some cases, the endoscope will be inserted into a small incision (cut) that your surgeon makes in your skin.
The endoscope will be passed through oesophagus and into the area that is being examined, such as the stomach or small intestine (duodenum). The small camera at the end of the endoscope relays images of your stomach or duodenum to a television monitor, allowing the healthcare professional to examine any abnormal areas. If required, a small tissue sample (biopsy) will be taken using a small cutting instrument attached to the end of the endoscope.
Depending on the exact nature of the procedure and its objectives, an endoscopy can take minutes to carry out.

4. Positive Impacts
It’s often used in the prevention, early detection, diagnosis, staging, and treatment of cancer.
Find Internal Bleeding
Better Prevention

5. Negative Impacts
Must train doctors on how to use new technologies being developed
Higher costs with new technology
Infection
Bleeding

6. Medical Thermography
Medical Thermography (digital infrared thermal imaging - DITI ) is used as a method of research for early pre-clinical diagnosis and control during treatment.
The intrinsic safety of this method makes infrared Thermography free from any limitations or contra- indications.
Thermography is a non-invasive, non-contact tool that uses the heat from your body to aid in making diagnosis of a host of health care conditions.
Thermography is completely safe and uses no radiation.

7. Medical Thermography

8. Component of Medical Thermography
It has two parts,
The IR camera or detector : Two categories of detectors are commonly found.
Based on thermal effects and include thermocouples, bolometers, thermopiles and pyroelectric detectors.
Relies on quantum effects and include photoconductors, and photovoltaic diodes.
A standard PC or laptop computer.

9. Working Principle
Any object whose temperature is above 0°K radiates infrared energy.
The amount of radiated energy is a function of the object's temperature and its relative efficiency of thermal radiation, known as emissivity.
Radiated energy (power) is proportional to the body's temperature, raised to the 4th power.
Steffan – Boltzmann Law:
This energy can be measured and an instrument calibrated to indicate the corresponding temperature of the surface it's "looking at".
Instruments which scan an object and create an image or spatial map of surface temperatures are referred to as thermal imagers.
IR cameras don’t see temperature. The IR camera captures the radiosity of the target it is viewing. Radiosity is defined as the infrared energy coming from a target modulated by the intervening atmosphere, and consists of emitted, reflected and transmitted IR energy .
How to see temperature differences?
Infrared Screening or Medical Thermography is based on the measurement of the skin's surface
temperature. This temperature is dependent on the blood circulation in the outer millimeters of the
skin. This blood flow is subject to complex regulation by the nervous system and local factors,
therefore it is not possible to "see" the condition of the internal organs with infrared screening but
rather pathological processes such as tumors, inflammation or tissue damage etc., as these
processes have an impact on the parent skin. The underlying processes lead to vascular and nerve
reactions which can be displayed as different heat patterns (thermograms) by means of infrared
screening.
Infrared screening can be widely applied in both primary and secondary health care. With infrared
screening, the primary care physician will be able to better and faster assess the patient’s situation
or severity of the complaints while the secondary health care specialist will obtain better
understanding of underlying processes within his medical specialty field.

10. Working Principle (…) I.E. = E.E. + T.E. + R.E.
Incident Energy: energy profile when viewed through a thermal imaging device,
Emitted Energy : generally what is intended to be measured,
Transmitted Energy : energy that passes through the subject from a remote thermal source, and
Reflected Energy : amount of energy that reflects off the surface of the object from a remote thermal source.

11. Working Principle (…)

12. Applications of thermography
Different types of pathologies
Extra-Cranial Vessel Disease
Neuro-Musculo-Skeletal
Vertebrae (nerve problems/arthritis)
Lower Extremity Vessel Disease

13. Need of image processing in medicine
Main tasks performed by the image processing unit in medicine are:
Interfacing analog outputs of sensors such as microscopes, endoscopes, ultrasound etc., to digitizers and in turn to Image Processing systems.
Image enhancements.
Changing density dynamic range of B/W images.
Color correction and manipulating of colors within a color image.
Contour detection and area calculations of the cells of a biomedical image.
Restoration and smoothing of images.
Registration of multiple images and creating mosaic of multiple images.
Construction of 3-D images from 2-D images.
Generation of negative images.
Zooming of images.
Removal of artifacts from the image.

14. Corresponding References
Endoscopy Related Link:
Thermography Related Link: