Methods of Physiological Psychology – UGC NET – Notes

Anatomical Methods

• CAT scanning (Computed Axial Tomography) is an advanced X-ray procedure that combines multiple X-ray images with the help of a computer to produce cross-sectional and sometimes 3D images of the internal organs and body structures.

• It was invented in 1972 by British engineer Godfrey N. Hounsfield and physicist Alan Cormack, marking a major advancement in medical imaging technology.

• The procedure uses a large donut-shaped X-ray machine that rotates around the body, capturing images from many different angles. These images are then processed by a computer to create detailed “slices” of the body, known as tomograms.

• Each tomogram represents a thin cross-section of the body, allowing doctors to observe internal structures layer by layer with high precision.

• CAT scans are widely used to examine the head, where they help detect traumatic injuries, such as blood clots, skull fractures, tumors, and infections.

• In the spine, CAT scans provide accurate visualization of the vertebrae and the spinal cord anatomy, making them useful for diagnosing structural abnormalities.

• They are also highly effective in studying internal organs, including the liver, gallbladder, pancreas, spleen, aorta, kidneys, uterus, and ovaries, helping in the identification of diseases or abnormalities.

• The amount of radiation exposure during a CAT scan is generally minimal, and in most cases (especially in men and non-pregnant women), it has not been shown to cause harmful effects.

• However, there are certain risks associated with CAT scans. For example, in pregnant women, alternative imaging methods may be recommended to avoid exposing the fetus to radiation.

• Individuals with asthma or allergies are also advised to be cautious, as the procedure often involves the use of a contrast medium, which may trigger allergic reactions.

• The use of contrast medium carries a slight risk of allergic reaction, particularly in patients with existing medical conditions such as diabetes, heart disease, kidney problems, or thyroid disorders, which can increase sensitivity to the substance.

MRI:

• Although CAT scanning was a major breakthrough in medical imaging, in many situations it has been replaced or supplemented by Magnetic Resonance Imaging (MRI) due to its advanced capabilities.

• MRI is a modern imaging technique that allows doctors to look inside the body without the use of X-rays, harmful dyes, or any form of surgical procedure, making it a safer alternative in many cases.

• Instead of radiation, MRI uses radio waves along with a powerful magnetic field to generate highly detailed images of internal body structures.

• The interaction between the magnetic field and body tissues produces signals, which are then processed by a computer to create clear and precise images.

• MRI is especially useful for visualizing soft tissues, such as the brain, muscles, ligaments, and internal organs, which are often harder to examine using other imaging techniques.

• A common application is the MRI of the head, where it provides detailed side-view images that help in diagnosing conditions related to the brain and surrounding structures.

• Overall, MRI offers remarkably clear and detailed pictures, making it an essential tool in modern diagnostics and often preferred when avoiding radiation exposure is important.

History and Development of MRI:

• MRI (Magnetic Resonance Imaging) is based on a fundamental physics principle known as nuclear magnetic resonance (NMR), which forms the scientific foundation of this imaging technique.

• The phenomenon of NMR was discovered in the 1930s by Felix Bloch and Edward Purcell, whose work significantly contributed to modern medical imaging.

• In nuclear magnetic resonance, a combination of a magnetic field and radio waves interacts with atoms in the body, causing them to emit tiny radio signals that can be detected and analyzed.

• In 1970, Raymond Damadian, a medical doctor and research scientist, discovered how this phenomenon could be applied as a tool for medical diagnosis, laying the groundwork for MRI technology.

• Just four years later, in 1974, a patent was granted for this innovation, marking the first patent ever issued in the field of MRI.

• In 1977, Dr. Damadian successfully built the first “whole-body” MRI scanner, which he named the “Indomitable”, representing a major milestone in medical engineering.

• The medical use of MRI expanded rapidly after its invention, with continuous advancements improving its efficiency and diagnostic capabilities.

• The first MRI machines became available in healthcare settings in the early 1980s, making this technology accessible for clinical use.

• By 2002, MRI had become widely adopted worldwide, with approximately 22,000 MRI scanners in operation and more than 60 million MRI examinations performed, highlighting its importance in modern medicine.

A full size MRI-Scanner:

• MRI (Magnetic Resonance Imaging) is widely used in modern medicine because it provides highly detailed and clear images, making it extremely effective for accurate diagnosis.

• It is commonly used to detect sports-related injuries, especially those involving joints such as the knee, elbow, shoulder, hip, and wrist, where soft tissue damage can be clearly visualized.

• MRI is also an important tool for examining the heart, aorta, and blood vessels, offering a fast and non-invasive method to diagnose artery diseases and various heart conditions.

• Doctors can use MRI to assess the size of heart chambers and determine the extent of damage caused by a heart disease or heart attack, which helps in planning treatment.

• Internal organs such as the lungs, liver, and spleen can also be examined in high detail, allowing detection of abnormalities that may not be visible through other imaging techniques.

• One of the major advantages of MRI is that it involves no radiation exposure, making it a safer option compared to many other diagnostic procedures.

• Due to its safety and precision, MRI is often the preferred diagnostic tool for examining sensitive areas such as the male and female reproductive systems, pelvis, hips, and bladder, where detailed imaging is essential.

Risks:

• One important safety concern with MRI (Magnetic Resonance Imaging) is that any undetected metal implant inside the body may be affected by the strong magnetic field, which can cause movement or interference.

• Because MRI uses powerful magnets, patients are carefully screened for metallic objects or implants such as pacemakers, clips, or prosthetics before undergoing the procedure.

• MRI is generally avoided during the first 12 weeks of pregnancy, as this is a critical period of fetal development and precaution is necessary.

• During early pregnancy, doctors prefer to limit exposure to any procedure involving strong magnetic fields, unless absolutely required.

• In most cases, scientists and doctors choose alternative imaging techniques like ultrasound, which is considered safer for monitoring the condition of pregnant women and the developing fetus.

• MRI is only recommended during pregnancy when there is a strong medical reason, and when the potential benefits outweigh any possible risks.