Methods of Diagnosis

Different Types of Diagnosis:

• By monitoring the body’s electrical activity:

1. Electrocardiogram (ECG)

An electrocardiogram (EKG or ECG) is a test that checks for problems with the electrical activity of your heart. An electrocardiogram shows the heart's electrical activity as line tracings on paper. The spikes and dips in the tracings are called waves.

The basic concept of electrocardiography is attaching electrodes to the body’s surface and measuring the electric impulses of the heart, and the device used for this purpose is the electrocardiogram. The transthoracic interpretation of the activity of the heart for a certain period of time that is detected with the help of electrodes attached to the skin’s surface and recorded by a device that is externally attached is called electrocardiography.

These days, electrocardiogram is used for both electrocardiography and electrocardiogram. The rate and the regularity of the heart beat are recorded by means of an ECG. Many further diagnoses that can be made out of an ECG are the size and the position of the four cardiac chambers, any blockages or damages in the heart, and the effectiveness of the drugs and devices used in cardiac treatment.

The heart is a muscular pump made up of four chambers: The two upper chambers are called atria, the two lower chambers are called ventricles. A natural electrical system causes the heart muscle to contract. This pumps blood through the heart to the lungs and the rest of the body.

Most often, ECG is employed only with humans. But for the purpose of research or even for medicinal purpose it may be employed on animals too.

An electrocardiogram is done to:

• Check the heart's electrical activity.
• Find the cause of unexplained chest pain or pressure. This could be caused by a heart attack, inflammation of the sac surrounding the heart (pericarditis), or angina.
• Find the cause of symptoms of heart disease. Symptoms include shortness of breath, dizziness, fainting, and heartbeats that are rapid and irregular (palpitations).
• Find out if the walls of the heart chambers are too thick.
• Check how well medicines are working and see if they are causing side effects that affect the heart.
• Check how well mechanical devices that are implanted in the heart, such as pacemakers, are working. These devices help to control the heartbeat.
• Check the health of the heart when other diseases or conditions are present. These include high blood pressure, high cholesterol, cigarette smoking, diabetes, and a family history of early heart disease.

2. Electroencephalogram (EEG)

An electroencephalogram (EEG) is a test used to evaluate the electrical activity in the brain. Brain cells communicate with each other through electrical impulses. An electroencephalogram can be used to help detect potential problems associated with this activity.

The test tracks and records brain wave patterns. Small, flat metal discs called electrodes are attached to the scalp with wires. The electrodes analyze the electrical impulses in the brain and send signals to a computer, where the results are recorded.

The electrical impulses in an electroencephalogram recording look like wavy lines with peaks and valleys. These lines allow doctors to quickly assess whether there are abnormal patterns. Any irregularities may be a sign of seizures or other brain disorders.

An electroencephalogram is used to detect problems in the electrical activity of the brain that may be associated with certain brain disorders. The measurements given by an EEG are used to confirm or rule out various conditions, including:

• seizure disorders (such as epilepsy)
• a head injury
• encephalitis (an inflammation of the brain)
• a brain tumor
• encephalopathy (a disease that causes brain dysfunction)
• memory problems
• sleep disorders
• stroke
• dementia

When someone is in a coma, an EEG may be performed to determine the level of brain activity. The test can also be used to monitor activity during brain surgery.

3. Electromyography (EMG)

Electromyography (EMG) is a procedure that assesses the health of muscles and nerves. It may be used diagnose suspected muscle or nerve disorders. There are usually two parts to an EMG procedure:

• The nerve conduction study.

• The needle EMG.

A nerve conduction study evaluates the nerves that control muscle movement, while a needle EMG assesses nerve activity within the muscles.

Abnormal EMG results usually indicate nerve or muscle damage.

Electromyography (EMG) is a diagnostic procedure that evaluates the health condition of muscles and the nerve cells that control them. These nerve cells are known as motor neurons. They transmit electrical signals that cause muscles to contract and relax. An EMG translates these signals into graphs or numbers, helping doctors to make a diagnosis.

A doctor will usually order an EMG when someone is showing symptoms of a muscle or nerve disorder. These symptoms may include tingling, numbness, or unexplained weakness in the limbs. EMG results can help the doctor diagnose muscle disorders, nerve disorders, and disorders affecting the connection between nerves and muscles.

There are two components to an EMG test: the nerve conduction study and needle EMG. The nerve conduction study is the first part of the procedure. It involves placing small sensors called surface electrodes on the skin to assess the ability of the motor neurons to send electrical signals. The second part of the EMG procedure, known as needle EMG, also uses sensors to evaluate electrical signals. The sensors are called needle electrodes, and they are directly inserted into muscle tissue to evaluate muscle activity when at rest and when contracted.

During each part of the EMG procedure, one electrode releases a very mild electrical signal while the other electrodes measure how long it takes for the signal to reach them. This mimics the natural electrical signals sent by the nerves to the muscles. The distance between the electrodes and time it takes for a signal to reach them is used to determine the speed at which the nerves are able to send and receive signals. An abnormal speed usually indicates a muscle or nerve disorder.

Some doctors may refer to electromyography as an electrodiagnostic exam.

4. Ergometry

Ergometry is a science that measures amounts of work activity, specifically, the measuring of the amount of physical work done by the body, usually during exertion. Ergometry is aimed at the performance of specific muscles or muscle groups and also includes a measure of power.

It is an ergometric stress test that is used to identify or exclude ischemic heart disease. The patient is submitted to physical exercise, usually on a treadmill or stationary bicycle, in order to increase his heart rate. As the pulse rate rises, the ECG records changes that may occur. These changes could be evidence of cardiac distress related to an oxygen deficit.

If the stress test is indicative of ischemia, physicians can build a plan of care that might include anything from diet management to medications and even surgical interventions. At specific intervals after the interventions are put in place, the patient will submit to subsequent ergometric stress tests to measure how well the interventions are working.

There have been some recent advances in the tools used in ergometrics including the arm ergometer, which looks like bicycle pedals for the arms. It has been found that patients can get almost as accurate a reading from the arm cycle as from using their legs on any of the more standard pieces of equipment. Now, people with balance issues, missing lower limbs or paralysis can benefit from ergometric testing too.

As the science evolves, practical applications are being discovered and used in fields outside of the general healthcare industry. For instance, athletic coaches, trainers and physicians are becoming more data driven in their assessments through the use of ergometry. Data is collected and used to measure things like heart function, breathing ability, and whether or a not a muscle is strong enough to achieve a specific task it is given.

One area where ergometry is playing a major role is in the diagnosing and treatment of football players who may have suffered a concussion. From the peewee leagues to the pros, athlete injuries – especially concussions – are being taken very seriously. How they perform in simple ergometric stress tests like the use of a stationary bike, treadmill or rowing machine is used to help determine if they are well enough to return to the game or need time to recuperate and then be tested again. Similar tests are now being put to use in other sports and activities including hockey, rugby and even rodeo bull riding.

Ergometric assessment is also being used by exercise physiologists to provide in-depth analysis and training recommendations for working athletes at all levels. Ergometry can be used to better understand energy expenditure, and the energy cost of performing specific exercises. The data can then be used to build better, more efficient training programs and regimens.

Ergometric data can lead to teaching the body how to be more efficient during energy expenditure and how to use that energy for more powerful and efficient performance. With continuous testing at regular intervals the athlete’s interpreted data can help build stronger performance with fewer injuries.

• Imaging techniques of diagnosis:

1. Ecography (Ultrasound imaging)

Ultrasound imaging (sonography) uses high-frequency sound waves to view inside the body. Because ultrasound images are captured in real-time, they can also show movement of the body's internal organs as well as blood flowing through the blood vessels. Unlike X-ray imaging, there is no ionizing radiation exposure associated with ultrasound imaging.

In an ultrasound exam, a transducer (probe) is placed directly on the skin or inside a body opening. A thin layer of gel is applied to the skin so that the ultrasound waves are transmitted from the transducer through the gel into the body.

The ultrasound image is produced based on the reflection of the waves off of the body structures. The strength (amplitude) of the sound signal and the time it takes for the wave to travel through the body provide the information necessary to produce an image.

Ultrasound imaging is a medical tool that can help a physician evaluate, diagnose and treat medical conditions. Common ultrasound imaging procedures include:

• Abdominal ultrasound (to visualize abdominal tissues and organs)
• Bone sonometry (to assess bone fragility)
• Breast ultrasound (to visualize breast tissue)
• Doppler fetal heart rate monitors (to listen to the fetal heart beat)
• Doppler ultrasound (to visualize blood flow through a blood vessel, organs, or other structures)
• Echocardiogram (to view the heart)
• Fetal ultrasound (to view the fetus in pregnancy)
• Ultrasound-guided biopsies (to collect a sample of tissue)
• Ophthalmic ultrasound (to visualize ocular structures)
• Ultrasound-guided needle placement (in blood vessels or other tissues of interest)

Ultrasound imaging has been used for over 20 years and has an excellent safety record. It is based on non-ionizing radiation, so it does not have the same risks as X-rays or other types of imaging systems that use ionizing radiation.

Although ultrasound imaging is generally considered safe when used prudently by appropriately trained health care providers, ultrasound energy has the potential to produce biological effects on the body. Ultrasound waves can heat the tissues slightly. In some cases, it can also produce small pockets of gas in body fluids or tissues (cavitation). The long-term consequences of these effects are still unknown.

2. Endoscopy

An endoscopy is a procedure in which your doctor uses specialized instruments to view and operate on the internal organs and vessels of your body. It allows surgeons to view problems within your body without making large incisions.

A surgeon inserts an endoscope through a small cut, or an opening in the body such as the mouth. An endoscope is a flexible tube with an attached camera that allows your doctor to see. Your doctor can use forceps (tongs) and scissors on the endoscope to operate or remove tissue for biopsy.

The endoscopy’s lighted camera allows your doctor to view potential problems without a large incision. A screen in the operating room lets the doctor see exactly what the endoscope sees.

The doctor may suspect that an organ or specific area of your body is infected, damaged, or cancerous. In this case, your doctor may order an endoscopic biopsy. An endoscopic biopsy involves using forceps in an endoscope to remove a small sample of tissue. They will send the sample to a lab for testing.

Your doctor will review your symptoms, perform a physical examination, and possibly order some blood tests prior to an endoscopy. These tests will help your doctor gain a more accurate understanding of the possible cause of your symptoms. These tests may also help them determine if the problems can be treated without an endoscopy or surgery.

Endoscopies fall into categories, based on the area of the body that they investigate. The American Cancer Society (ACS) lists the following types of endoscopies:

• Arthroscopy is used to examine your joints. The scope is inserted through a small incision near the joint being examined.
• Bronchoscopy is used to examine your lungs. The scope is inserted into your nose or mouth.
• Colonoscopy is used to examine your colon. The scope is inserted through your anus.
• Cystoscopy is used to examine your bladder. The scope is inserted through your urethra, which is the hole through which you urinate.
• Enteroscopy is used to examine your small intestine. The scope is inserted through your mouth or anus.
• Hysteroscopy is used for the examining the inside of your uterus. The scope is inserted through your vagina.
• Laparoscopy is used to examine your abdominal or pelvic area. The scope is inserted through a small incision near the area that’s being examined.
• Laryngoscopy is used to examine your voice box, or larynx. The scope is inserted through your mouth or nostril.
• Mediastinoscopy is used to examine the area between the lungs called the “mediastinum.” The scope is inserted through an incision above your breastbone.
• Upper gastrointestinal endoscopy is used to examine your esophagus and upper intestinal tract. The scope is inserted through your mouth.
• Ureteroscopy is used to examine your ureter. The scope is inserted through your urethra.

• Radiological:

1. X-Ray

An X-ray is a common imaging test that’s been used for decades. It can help your doctor view the inside of your body without having to make an incision. This can help them diagnose, monitor, and treat many medical conditions.

Different types of X-rays are used for different purposes. For example, your doctor may order a mammogram to examine your breasts. Or they may order an X-ray with a barium enema to get a closer look at your gastrointestinal tract.

There are some risks involved in getting an X-ray. But for most people, the potential benefits outweigh the risks. Your doctor may order an X-ray to:

• examine an area where you’re experiencing pain or discomfort
• monitor the progression of a diagnosed disease, such as osteoporosis
• check how well a prescribed treatment is working

Conditions that may call for an X-ray include:

• bone cancer
• breast tumors
• enlarged heart
• blocked blood vessels
• conditions affecting your lungs
• digestive problems
• fractures
• infections
• osteoporosis
• arthritis
• tooth decay
• needing to retrieve swallowed items

X-rays use small amounts of radiation to create images of your body. The level of radiation exposure is considered safe for most adults, but not for a developing baby. If you’re pregnant or believe you could be pregnant, tell your doctor before you have an X-ray. They may suggest a different imaging method, such as an MRI.

If you’re having an X-ray done to help diagnose or manage a painful condition, such as a broken bone, you may experience pain or discomfort during the test. You will need to hold your body in certain positions while the images are being taken. This may cause you pain or discomfort. Your doctor may recommend taking pain medicine beforehand.

If you ingest a contrast material before your X-ray, it may cause side effects. These include:

• hives
• itching
• nausea
• lightheadedness
• a metallic taste in your mouth

In very rare cases, the dye can cause a severe reaction, such as anaphylactic shock, very low blood pressure, or cardiac arrest. If you suspect you’re having a severe reaction, contact your doctor immediately.

1. 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.

You may be able to have an MRI with an open machine that doesn't enclose your entire body. But open MRI machines aren't available everywhere. The pictures from an open MRI may not be as good as those from a standard MRI machine .

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 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 as arthritis, 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 as spinal stenosis, disc bulges, and spinal tumors.

A magnetic resonance imaging (MRI) test is usually done by an MRI technologist. The pictures are usually interpreted by a radiologist. But some other types of doctors can also interpret an MRI scan.

You will need to remove all metal objects (such as hearing aids, dentures, jewelry, watches, and hairpins) from your body because these objects may be attracted to the powerful magnet used for the test.

You will need to take off all or most of your clothes, depending on which area is examined (you may be allowed to keep on your underwear if it is not in the way). You will be given a gown to use during the test. If you are allowed to keep some of your clothes on, you should empty your pockets of any coins and cards (such as credit cards or ATM cards) with scanner strips on them because the MRI magnet may erase the information on the cards.

During the test, you usually lie on your back on a table that is part of the MRI scanner. Your head, chest, and arms may be held with straps to help you remain still. The table will slide into the space that contains the magnet. A device called a coil may be placed over or wrapped around the area to be scanned. A special belt strap may be used to sense your breathing or heartbeat. This triggers the machine to take the scan at the right time.

Some people feel nervous (claustrophobic) inside the MRI magnet. If this keeps you from lying still, you can be given a sedative to help you relax. Some MRI machines (called open MRI) are now made so that the magnet does not enclose your entire body. Open MRI machines may be helpful if you are claustrophobic, but they are not available everywhere. The pictures from an open MRI may not be as good as those from a standard MRI machine .

Inside the scanner you will hear a fan and feel air moving. You may also hear tapping or snapping noises as the MRI scans are taken. You may be given earplugs or headphones with music to reduce the noise. It is very important to hold completely still while the scan is being done. You may be asked to hold your breath for short periods of time.

2. Computerized Tomography (CT Scan)

The term “computerized tomography”, or CT, refers to a computerized x-ray imaging procedure in which a narrow beam of x-rays is aimed at a patient and quickly rotated around the body, producing signals that are processed by the machine’s computer to generate cross-sectional images—or “slices”—of the body. These slices are called tomographic images and contain more detailed information than conventional x-rays. Once a number of successive slices are collected by the machine’s computer, they can be digitally “stacked” together to form a three-dimensional image of the patient that allows for easier identification and location of basic structures as well as possible tumors or abnormalities.

Unlike a conventional x-ray—which uses a fixed x-ray tube—a CT scanner uses a motorized x-ray source that rotates around the circular opening of a donut-shaped structure called a gantry. During a CT scan, the patient lies on a bed that slowly moves through the gantry while the x-ray tube rotates around the patient, shooting narrow beams of x-rays through the body. Instead of film, CT scanners use special digital x-ray detectors, which are located directly opposite the x-ray source. As the x-rays leave the patient, they are picked up by the detectors and transmitted to a computer.

Each time the x-ray source completes one full rotation, the CT computer uses sophisticated mathematical techniques to construct a 2D image slice of the patient. The thickness of the tissue represented in each image slice can vary depending on the CT machine used, but usually ranges from 1-10 millimeters. When a full slice is completed, the image is stored and the motorized bed is moved forward incrementally into the gantry. The x-ray scanning process is then repeated to produce another image slice. This process continues until the desired number of slices is collected.

Image slices can either be displayed individually or stacked together by the computer to generate a 3D image of the patient that shows the skeleton, organs, and tissues as well as any abnormalities the physician is trying to identify. This method has many advantages including the ability to rotate the 3D image in space or to view slices in succession, making it easier to find the exact place where a problem may be located.  

CT scans can be used to identify disease or injury within various regions of the body. For example, CT has become a useful screening tool for detecting possible tumors or lesions within the abdomen. A CT scan of the heart may be ordered when various types of heart disease or abnormalities are suspected. CT can also be used to image the head in order to locate injuries, tumors, clots leading to stroke, hemorrhage, and other conditions. It can image the lungs in order to reveal the presence of tumors, pulmonary embolisms (blood clots), excess fluid, and other conditions such as emphysema or pneumonia. A CT scan is particularly useful when imaging complex bone fractures, severely eroded joints, or bone tumors since it usually produces more detail than would be possible with a conventional x-ray.

1. Gamma Ray

Gamma radiation is one of the three types of natural radioactivity. Gamma rays are electromagnetic radiation, like X-rays.  The other two types of natural radioactivity are alpha and beta radiation, which are in the form of particles.   Gamma rays are the most energetic form of electromagnetic radiation, with a very short wavelength of less than one-tenth of a nanometer.

Gamma radiation is the product of radioactive atoms. Depending upon the ratio of neutrons to protons within its nucleus, an isotope of a particular element may be stable or unstable. When the binding energy is not strong enough to hold the nucleus of an atom together, the atom is said to be unstable. Atoms with unstable nuclei are constantly changing as a result of the imbalance of energy within the nucleus. Over time, the nuclei of unstable isotopes spontaneously disintegrate, or transform, in a process known as radioactive decay. Various types of penetrating radiation may be emitted from the nucleus and/or its surrounding electrons. Nuclides which undergo radioactive decay are called radionuclides. Any material which contains measurable amounts of one or more radionuclides is a radioactive material.

The fact that gamma rays kill any living organism is an advantage to the medical field, especially the field of oncology. High doses of gamma rays can kill cancerous cells in a process called radiation therapy (lower doses could lead to cells becoming cancerous). The process of radiation therapy kills the DNA of cancerous cells, preventing growth or division with the use of a machine called an accelerator or radioactive sources placed inside the patient. The main focus of the radiation oncologist is to target the dose of radiation to the cancer as much as possible to avoid side effects. Side effects depend on the area of treatment. Gamma rays are also used for sterilization of medical equipment. Gamma rays easily pass through the packaging of medical equipment (can only be stopped by thick lead) and kill living tissue such as viruses and bacteria.

Gamma rays can be produced by several processes that are both nuclear and non-nuclear. The usual and most common way by which gamma rays arise is a process called gamma decay. This process usually occurs after other types of decay, namely alpha or beta, have occurred. This is the process most commonly used in the field of medicine. Another way by which gamma rays are produced is during the natural phenomena called terrestrial thunderstorms.  During thunderstorms, high intensity static electric fields accelerate electrons, and as a result gamma rays are produced by the ‘Bremsstrahlung’ method when the electrons are slowed down by atoms in the atmosphere during collision.

Gamma rays are widely used in medicine and specifically in the area of oncology to treat malignant and cancerous tumors during a process called gamma knife surgery. In this type of treatment, concentrated beams of gamma rays are directed at tumors in order to kill cancerous cells. These high energy rays ionize water in the cancerous cell, producing H and OH free radicals. The free radicals are highly reactive and therefore interact and damage chromosomes in the cell. Some of the radiation directed at the tumor interacts and directly damages chromosomes without the use of free radicals.

Gamma rays are also used for imaging techniques in nuclear medicine for diagnostic purposes, for example in the use of “PET Scan” and ‘Gamma Cameras’.

Side Effects

There are many side effects attributed to the use of gamma rays for treatment of cancers. These side effects are classified according to the region in the body that is affected

Location	Side Effects
Head and Neck	Dry mouth, mouth and gum sores, difficulty swallowing, jaw stiffness, lymphedema, or tooth decay
Thorax	Shortness of breath, breast or nipple soreness, shoulder stiffness, cough, fever, or radiation pneumonia.
Stomach and Abdomen	Nausea, vomiting, or diarrhea
Pelvis	Diarrhea, rectal bleeding, bladder irritation and sexual problems in both men and women. May cause permanent infertility

Conclusion

Scientists are continuously working on new ways to spare healthy cells and narrow the concentration of the ionizing beams on cancerous cells. The use of gamma rays in medicine continues to be the primary method of treatment in the field of oncology. It is therefore continuously advancing technologically and new methods of treatment with gamma rays are being developed at a rapid rate.

1. Cardiac Catheterization

Cardiac catheterization (cardiac cath or heart cath) is a procedure to examine how well your heart is working.

A thin, hollow tube called a catheter is inserted into a large blood vessel that leads to your heart. Cardiac cath is performed to find out if you have disease of the heart muscle, valves or coronary (heart) arteries. During the procedure, the pressure and blood flow in your heart can be measured. Coronary angiography is done during cardiac catheterization. A contrast dye visible in X-rays is injected through the catheter. X-ray images show the dye as it flows through the heart arteries. This shows where arteries are blocked.

The chances that problems will develop during cardiac cath are low.

A cardiac cath  provides information on how well your heart works, identifies problems and allows for procedures to open blocked arteries. For example, during cardiac cath your doctor may:

• Take X-rays using contrast dye injected through the catheter to look for narrowed or blocked coronary arteries. This is called coronary angiography or coronary arteriography.
• Perform a percutaneous coronary intervention (PCI) such as coronary angioplasty with stenting to open up narrowed or blocked segments of a coronary artery.
• Check the pressure in the four chambers of your heart.
• Take samples of blood to measure the oxygen content in the four chambers of your heart.
• Evaluate the ability of the pumping chambers to contract.
• Look for defects in the valves or chambers of your heart.
• Remove a small piece of heart tissue to examine under a microscope (biopsy).

What are the risks of cardiac catheterization?

Cardiac cath is usually very safe. A small number of people have minor problems. Some develop bruises where the catheter had been inserted (puncture site). The contrast dye that makes the arteries show up on X-rays causes some people to feel sick to their stomachs, get itchy or develop hives.

• You will be given instructions about what to eat and drink during the 24 hours before the test.
• Usually, you will be asked not to eat or drink anything for six to eight hours before the cath procedure.
• Tell your doctor about any medicines (including over-the-counter, herbs and vitamins) you take. The doctor may ask you not to take them before your cath procedure. Don’t stop taking your medicine until your doctor tells you to.
• Tell your doctor or nurse if you are allergic to anything, especially iodine, shellfish, latex or rubber products, medicines like penicillin, or X-ray dye.
• Arrange to have someone drive you home after your procedure.
• If you usually wear a hearing aid, wear it during your procedure. If you wear glasses, bring them to your appointment.

What happens during cardiac catheterization?

A doctor with special training performs the procedure with a team of nurses and technicians. The procedure is done in a hospital cardiac catheterization (cath) lab.

• Before the cath procedure, a nurse will put an IV (intravenous) line into a vein in your arm so you can get the sedative to help you relax, but you’ll be awake and able to follow instructions during the procedure.
• The nurse will clean and shave the area where the doctor will be working. This is usually in the groin area.
• A local anesthetic is usually given to numb the needle puncture site.
• The doctor will make a needle puncture through your skin and into a large blood vessel. A small straw-sized tube (called a sheath) will be inserted into the vessel. The doctor will gently guide a catheter (a long, thin tube) into your vessel through the sheath. A video screen will show the position of the catheter as it is threaded through the major blood vessels and to the heart. You may feel some pressure in your groin, but you shouldn’t feel any pain.
• Various instruments may be placed at the tip of the catheter. They include instruments to measure the pressure of blood in each heart chamber and in blood vessels connected to the heart, view the interior of blood vessels, take blood samples from different parts of the heart, or remove a tissue sample (biopsy) from inside the heart.
• When a catheter is used to inject a dye that can be seen on X-rays, the procedure is called angiography.
• When a catheter is used to clear a narrowed or blocked artery, the procedure is called angioplasty or a percutaneous coronary intervention (PCI).
• When a catheter is used to widen a narrowed heart valve opening, the procedure is called valvuloplasty.
• The doctor will remove the catheters and the sheath. Your nurse will put pressure on the site to prevent bleeding. Sometimes a special closure device is used. The procedure lasts about an hour.

1. Biopsy (3 types)

• Surgical

An incisional biopsy is a procedure in which a small area of tissue is taken to identify the composition (or make-up) of a lesion or abnormality. An excisional biopsy is a more involved procedure where the entire abnormality or area of interest is removed.

To further clarify this, there are four options for obtaining a tissue sample.

• A fine needle aspiration is the simplest, least invasive test and uses the smallest needle to simply remove cells from the abnormality. This is not always adequate to obtain a diagnosis, depending on the area to be biopsied.
• A core needle biopsy removes not only cells, but also a small amount of the surrounding tissue. This provides additional information to assist in the identification of the lesion.
• An incisional biopsy takes out even more surrounding tissue. It takes out some of the abnormality, but not all. The doctor will slice into the lesion and remove only a portion of it. If the lesion is found to be cancerous, further surgery may be needed to remove the whole abnormality.
• An excisional biopsy generally removes the entire area in question.
• If the lesion of interest is large, an incisional biopsy may be performed to make sure the cosmetic outcome following the procedure is suitable. Alternatively, if the abnormality is small, an excisional biopsy may be performed. Ultimately, your doctor will decide what is most appropriate for you based on the location and size of the lesion and the suspected diagnosis.
• While a core needle biopsy can be performed on most parts of the body, incisional and excisional biopsies are most often used for lesions involving the breast, skin, muscles, and lymph nodes.

• Bone Marrow

A bone marrow biopsy is the removal of marrow from inside bone. Bone marrow is the soft tissue inside bones that helps form blood cells. It is found in the hollow part of most bones.

Bone marrow biopsy is not the same as bone marrow aspiration. An aspiration removes a small amount of marrow in liquid form for examination.

How the Test is Performed

A bone marrow biopsy may be done in the health care provider's office or in a hospital. The sample may be taken from the pelvic or breast bone. Sometimes, another area is used.

Marrow is removed in the following steps:

• If needed, you are given medicine to help you relax.
• The provider cleans the skin and injects numbing medicine into the area and surface of the bone.
• A biopsy needle is inserted into the bone. The center of the needle is removed and the hollowed needle is moved deeper into the bone. This captures a tiny sample, or core, of bone marrow within the needle.
• The sample and needle are removed.
• Pressure and then a bandage are applied to the skin.

A bone marrow aspiration may also be done, usually before the biopsy is taken. After the skin is numbed, the needle is inserted into the bone, and a syringe is used to withdraw the liquid bone marrow. If this is done, the needle will be removed and repositioned. Or, another needle may be used for the biopsy.

• Needle

A needle biopsy is a procedure to obtain a sample of cells from your body for laboratory testing. Common needle biopsy procedures include fine-needle aspiration and core needle biopsy. Needle biopsy may be used to take tissue or fluid samples from muscles, bones, and other organs, such as the liver or lungs.

Your doctor may suggest a needle biopsy to help diagnose a medical condition or to rule out a disease or condition. A needle biopsy may also be used to assess the progress of a treatment.

The sample from your needle biopsy may help your doctor determine what's causing:

• A mass or lump. A needle biopsy may reveal whether a mass or lump is a cyst, an infection, a benign tumor or cancer.
• An infection. Analysis from a needle biopsy can help doctors determine what germs are causing an infection so that the most effective medications can be used.
• Inflammation. A needle biopsy sample may reveal what's causing inflammation, and what types of cells are involved.

You may also undergo imaging tests, such as a computerized tomography (CT) scan or an ultrasound, before your needle biopsy. Sometimes these tests are also used during the needle biopsy procedure to more accurately locate the area to be biopsied.

Needle biopsy carries a small risk of bleeding and infection at the site where the needle was inserted. Some mild pain can be expected after needle biopsy, though it is usually controlled with over-the-counter pain relievers or prescription medications.

Call your doctor if you experience:

• Fever
• Pain at the biopsy site that worsens or isn't helped by medications
• Swelling at the biopsy site
• Drainage from the biopsy site
• Bleeding that doesn't stop with pressure or a bandage

• Skin

A skin biopsy is a procedure in which a doctor cuts and removes a small sample of skin to have it tested. This sample may help your doctor diagnose diseases such as skin cancer, infection, or other skin disorders.

There are several types of skin biopsy, including:

• Shave biopsy: The doctor shaves a thin layer from the top of a lesion.
• Punch biopsy: The doctor uses an instrument called a punch to remove a circular section through all layers of the lesion.
• Excisional biopsy: The doctor uses a scalpel to take off the entire lesion. This method is used for smaller lesions.
• Incisional biopsy: The doctor uses a scalpel to remove a small sample of a large lesion.

The doctor will first cleanse the biopsy site, and then numb the skin by using an anesthetic (pain-relieving) injection. The skin is then sampled using one of the above procedures. Shave biopsies do not usually need stitches, while punch, excisional, and incisional biopsies will sometimes be closed with sutures or steri-strips. The procedure is usually done in the doctor's office.

• Kidney

A kidney biopsy involves taking one or more tiny pieces (samples) of your kidney to look at with special microscopes. The microscopes make it possible to see the samples in greater detail.

The biopsy sample may be taken in one of two ways:

1. Percutaneous (through the skin) biopsy: a needle placed through the skin that lies over the kidney and guided to the right place in the kidney, usually with the help of ultrasound.
2. Open biopsy: the kidney sample is taken directly from the kidney during surgery.
3. The kidney sample is then sent to a doctor (pathologist) who looks at it with microscopes. He or she will check for any signs of disease.

Some kidney problems can often be found with blood and urine tests, a sonogram (an image made by ultrasound) or other special x-rays, and a physical exam rather than a biopsy. But in some patients with certain types of kidney disease, and those with a kidney transplant that is not working well, a correct diagnosis can only be made with a kidney biopsy.

Specific reasons to do a kidney biopsy include:

• Blood in the urine (hematuria) or protein in the urine (proteinuria)
• Abnormal blood test results
• Acute or chronic kidney disease with no clear cause
• Nephrotic syndrome and glomerular disease (which happens when the filtering units of the kidney are damaged)

A kidney biopsy may also help to find:

• If a disease is getting better with treatment or if it is getting worse. It may also show a problem that cannot be cured, but can be slowed down by other therapy.
• How much permanent damage has happened in the kidney.
• Why a transplanted kidney is not working well and helps your doctor decide on further treatment.
• A kidney tumor.
• Other unusual or special conditions.
• If a certain treatment is hurting your kidneys

Your healthcare provider should explain the reasons for the kidney biopsy. You should know why it is necessary, the benefits, and any risks. You will be asked to sign a consent (permission) form to make sure you are aware of any risks. Be sure you understand the risks before you sign the consent form. You may want to write down a list of questions about the biopsy.

The risks of kidney biopsy are very small, but they should be discussed with your healthcare provider. As in other medical and surgical procedures, certain complications may happen even though every effort is taken to prevent them. A blood transfusion may be needed if serious bleeding occurs. Rarely, surgery may be needed to fix a blood vessel that is damaged during the procedure.

A kidney biopsy is usually done in a hospital. An overnight stay may be needed to watch for any problems. You may be awake with only light sedation, or asleep under general anesthesia. You will be lying face down with a pillow under your rib cage. If the biopsy is done on a transplanted kidney, you will be lying on your back.

• Liver

A liver biopsy is a procedure in which a small needle is inserted into the liver to collect a tissue sample. The tissue is then analyzed in a laboratory to help doctors diagnose a variety of disorders and diseases in the liver. A liver biopsy is most often performed to help identify the cause of:

• Persistent abnormal liver blood tests (liver enzymes)
• Unexplained yellowing of the skin (jaundice)
• A liver abnormality found on ultrasound, CT scan, or nuclear scan
• Unexplained enlargement of the liver

A liver biopsy can also be used to estimate the degree of liver damage, to grade and stage hepatitis B and C, and to determine the best treatment for the damage or disease.

In most instances, there are no complications in obtaining a liver biopsy. However, rarely, internal bleeding may occur, as well as a leak of bile from the liver or gallbladder. There is a slight risk of a pneumothorax, also called a collapsed lung, if the biopsy needle makes a hole in the chest wall causing air to enter.