Magnetic resonance imaging (MRI)

Magnetic resonance imaging (MRI) is a test that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body. In many cases MRI gives different information about structures in the body than can be seen with an X-ray, ultrasound, or computed tomography (CT) scan. MRI also may show problems that cannot be seen with other imaging methods.

For an MRI test, the area of the body being studied is placed inside a special machine that contains a strong magnet. Pictures from an MRI scan are digital images that can be saved and stored on a computer for more study. The images also can be reviewed remotely, such as in a clinic or an operating room. In some cases, contrast material may be used during the MRI scan to show certain structures more clearly.

Magnetic resonance imaging (MRI) is done for many reasons. It is used to find problems such as tumors, bleeding, injury, blood vessel diseases, or infection. MRI also may be done to provide more information about a problem seen on an X-ray, ultrasound scan, or CT scan. Contrast material may be used during MRI to show abnormal tissue more clearly. An MRI scan can be done for the:

• Head. MRI can look at the brain for tumors, an aneurysm, bleeding in the brain, nerve injury, and other problems, such as damage caused by a stroke. MRI can also find problems of the eyes and optic nerves, and the ears and auditory nerves.

• Chest. MRI of the chest can look at the heart, the valves, and coronary blood vessels. It can show if the heart or lungs are damaged. MRI of the chest may also be used to look for breast or lung cancer.

• Blood vessels. Using MRI to look at blood vessels and the flow of blood through them is called magnetic resonance angiography (MRA). It can find problems of the arteries and veins, such as an aneurysm, a blocked blood vessel, or the torn lining of a blood vessel (dissection). Sometimes contrast material is used to see the blood vessels more clearly.

• Abdomen and pelvis. MRI can find problems in the organs and structures in the belly, such as the liver, gallbladder, pancreas, kidneys, and bladder. It is used to find tumors, bleeding, infection, and blockage. In women, it can look at the uterus and ovaries. In men, it looks at the prostate.

• Bones and joints. MRI can check for problems of the bones and joints, such asarthritis, problems with the temporomandibular joint, bone marrow problems,bone tumors, cartilage problems, torn ligaments or tendons, or infection. MRI may also be used to tell if a bone is broken when X-ray results are not clear. MRI is done more commonly than other tests to check for some bone and joint problems.

• Spine. MRI can check the discs and nerves of the spine for conditions such asspinal stenosis, disc bulges, and spinal tumors.

What Is Coronary Angiography?

Coronary angiography (an-jee-OG-rah-fee) is a test that uses dye and special x rays to show the insides of your coronary arteries. The coronary arteries supply oxygen-rich blood to your heart.

A waxy substance called plaque (plak) can build up inside the coronary arteries. The buildup of plaque in the coronary arteries is called coronary heart disease(CHD).

Over time, plaque can harden or rupture (break open). Hardened plaque narrows the coronary arteries and reduces the flow of oxygen-rich blood to the heart. This can cause chest pain or discomfort called angina (an-JI-nuh or AN-juh-nuh).

If the plaque ruptures, a blood clot can form on its surface. A large blood clot can mostly or completely block blood flow through a coronary artery. This is the most common cause of a heart attack. Over time, ruptured plaque also hardens and narrows the coronary arteries.

Overview

During coronary angiography, special dye is released into the bloodstream. The dye makes the coronary arteries visible on x-ray pictures. This helps doctors see blockages in the arteries.  

A procedure called cardiac catheterization (KATH-eh-ter-ih-ZA-shun) is used to get the dye into the coronary arteries.

For this procedure, a thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. The tube is threaded into your coronary arteries, and the dye is released into your bloodstream. X-ray pictures are taken while the dye is flowing through the coronary arteries.

Cardiologists (heart specialists) usually do cardiac catheterization in a hospital. You're awake during the procedure, and it causes little or no pain. However, you may feel some soreness in the blood vessel where the catheter was inserted.

Cardiac catheterization rarely causes serious complications.

X-Ray Radiography

X-Ray Radiography is a nondestructive semiconductor failure analysis technique used to examine the interior details of the package. It operates on the principle of dissimilar transmission of X-Rays through different materials.  The ability of a material to block X-Rays increases with its density. It is this dissimilar transmission of X-rays through different materials that is utilized to create an image of various contrasts.  X-Ray imaging may be accomplished on film, by fluoroscopy, or by using image intensifying video systems.

  

A typical modern X-Ray inspection equipment has a filament that produces an electron beam used to excite a target into producing X-Rays. The X-Ray emissions are then directed to and transmitted through the specimen. The transmitted X-Rays are collected by a detector, translated into electric signals, amplified, and transformed into an X-Ray image.

           

The varying densities of the various materials comprising the specimen allow different amounts of X-Rays to pass through, resulting in varying grayscale levels on the X-Ray image.  The quality of the X-Ray image formed therefore depends not only on the proper operation of the X-Ray equipment used, but on the composition of the specimen as well. Some materials used in semiconductor assembly, such as aluminum wires, are transparent to X-Ray, and are therefore invisible in X-Ray images.           

                              

X-Ray radiography is commonly used to inspect for wiresweeping and other wirebond problems, die attach voids, package voids and cracks. It is excellent for determining leadframe outlines as well. Traditional x-ray systems use photosensitive films to record the x-ray image. Since X-Rays are not easy to focus, this method produces low-resolution images, which greatly limits its usefulness. 

                            

Today, X-Ray systems use a microspot source, real-time detection and automated manipulation of the sample to achieve higher resolution and throughput. These systems are capable of detecting much finer package details and defects.

Basic Mammography Techniques

It is the mammographer's aim to produce a consistently high quality mammographic image.This is paramount in diagnostic mammography to enable the Radiologist to accurately evaluate the image.

Views

Cranio Caudal View

• This view includes most of the breast tissue. 

• Ensure firstly the bucky height is correct and at the level of the infra mammary fold so the breast is fully elevated including the posterior tissue. This reduces the chance of pulling the skin as the compression comes down. 

• The patient stands facing the bucky with her head turned away from the side being examined. Keep one arm around her shoulder and the other hand to position the breast. Position from the medial side of the woman

Criteria for assessing the CC view 

1. As much medial and lateral tissue visualised as possible 

2. Aim to include pectoral muscle 

3. Correct exposure 

4. Adequate compression 

5. No movement 

6. Proper processing 

7. No artefacts 

8. No skin folds or shoulder in view 

9. Images should be symmetrical 

10. Correct film ID-patient details, markers, date, and radiographer's initials 

11. Nipple in profile-if difficult, do an extra nipple view.

Medio-Lateral Oblique

• The degree of angulation depends on the angle of the pectoralis major muscle. The film holder should be parallel to the angle of the pectoral muscle at the mid axillary line. Generally taller, slimmer women need a steeper angle. Smaller women may need to be more lateral and larger breasted women less than 45 degrees. 

• Ask the woman the place her hand on the bar as the armpit is placed over the bucky corner. Ensure no folds on the lateral side of the breast and check all the lateral tissue is on the edge of the Bucky. The arm should be resting over and on to the back of the bucky. 

• Gently push the shoulder down by the hand on the clavicle. 

• Once sure there is adequate axillary tissue, position the breast and apply the compression while supporting the inferior aspect. The breast needs to be pulled up and out so that it will be imaged at 90 degrees to the chest wall. 

• Ensure no folds and smooth out the inframammary region. To be sure that all the breast tissue has been imaged the top of the compression plate should be just below the clavicle and the inner edge alongside the sternum. 

Building Medical words

• a or an or ana - without
» a-calculia (can't do math)
» a-kinesia (without movement)
» a-phasia (without speech)
» a-plasia (not formed or not formed normally) e.g. aplastic anemia

• brady - slow:
» brady-cardia (slow pulse)
» brady-kinesia (slow or paucity of movements)

• dys - abnormal, painful
» dys-function
» dys-phagia (abnormal eating/swallowing)
» dys-phasia (abnormal speech - also aphasia)
» dys-plasia (abnormal cells, tissue, organ)
» dys-pepsia (impaird or painful digestion)
» dys-pnea (bad breathing, shortness or breath or SOB, "air hunger"

• lepid - scales
» lepido-ptera (scale wing)

• lepto - thin
» lepto-meninges (pia and arachnoid)

• morphos - shape
» ana-morphic (without shape)
» dys-morphic (badly shaped)
» poly-morphic (many shapes)

• oligo - few
» oligo-dendrocytes (like astrocyte, but fewer branches)

For more knowledge...

Radiography

Medical radiography is a broad term that covers several types of studies that require the visualization of the internal parts of the body using x-ray techniques. Simply radiography means a technique for generating and recording an x-ray pattern for the purpose of providing the user with a static image(s) after termination of the exposure. It is differentiated as  fluoroscopy, mammography, and computed tomography according to the X-ray energy, recording system as well as the region of the imaged. Radiography may also be used during the planning of radiation therapy treatment.  It is used to diagnose or treat patients by recording images of the internal structure of the body to assess the presence or absence of disease, foreign objects, and structural damage or anomaly.

During a radiographic procedure, an x-ray beam is passed through the body. A portion of the x-rays are absorbed or scattered by the internal structure and the remaining x-ray pattern is transmitted to a detector so that an image may be recorded for later evaluation. The recoding of the pattern may occur on film or through electronic means.

Application 

Radiography is used in many types of examinations and procedures where a record of a static image is desired. Some examples include:

• Dental examination
• Verification of correct placement of surgical markers prior to invasive procedures
• Mammography
• Orthopedic evaluations
• Spot film or static recording during fluoroscopy
• Chiropractic examinations

What is Radiography

Radiography uses the science of radiation to produce images of tissues and organs. 

Radiography Definition

Radiography is used by medical professionals to diagnose and treat medical conditions. The diagonostic side of radiography uses specialized equipment to creat images, such as x-rays, that show the inside of the human body. X-rays can be recorded on film or as a computerized image. Radiography can also be used to treat internal malignancies like tumors. A doctor who specializes in radiography is called a radiologist, while an assistant is referred as a radiologic technologist.