X-ray examination

The examination method provides a quick result and is painless. X-rays are particularly good at showing injuries and diseases of solid tissue such as bone. However, due to the risk of radiation exposure, it is important to always weigh up the benefits and risks of an X-ray.

Overview: What is an X-ray examination?

X-ray examination is an imaging procedure that uses X-rays. These are generated in an X-ray tube. The examination method is a quick diagnostic procedure and causes no pain. X-rays are produced when electrically charged particles (electrons) are accelerated and decelerated or change their direction of movement. Energy is released during this process.

X-rays are more energetic than other types of radiation. This allows them to penetrate soft materials such as human tissue and show changes or deviations from the “body norm”. This allows us to detect bone fractures, arthrosis, inflammation, tumors or foreign bodies on an X-ray. Special X-ray examinations can also be used to check the state of health and function of organs such as the heart muscle, kidneys or gastrointestinal tract.

How does the X-ray examination work?

X-rays pass through the human body and hit a special digital reader on the other side. Depending on the density of the tissue in question, some of the X-rays are stopped as they pass through. The more radiation hits the digital reader, the more it excites these areas, which are then displayed in black. If only a small amount of radiation reaches the other side, the part shown remains bright.

Bones, for example, have a relatively high density so that only a few rays penetrate them. Accordingly, bones are shown brightly on the X-ray image. In contrast, lung tissue, but fat and muscle tissue is less dense, so that more X-rays can pass through. This is why lung tissue appears dark on an X-ray.

X-ray examination - the procedure

The examination procedure varies slightly depending on whether you need an X-ray with or without contrast medium. An image without contrast medium is also referred to as a “native X-ray image”. A contrast agent may be required if you want to x-ray organs filled with air or gas, such as the stomach or lungs, as well as soft tissue such as fat, muscles and skin. This is because they are permeable to X-rays and appear dark, which means that they do not show up well on the X-ray image. A contrast agent improves the image.

If a contrast agent is required, you will be given this before the X-ray as a drink, as an injection via a syringe, as an enema (to visualize the colon) or via an endoscope (when examining the bile ducts or pancreatic ducts). After a short time, the contrast medium fills body cavities or vessels or is deposited on the organ walls. This enables the doctor to assess the course of the organs and their surface structure.

For the examination of internal organs such as kidneys, gall bladder, stomach and intestines, you must fast a few hours beforehand. The same is the case if a contrast agent has been administered beforehand.

X-ray examination procedure

For the actual examination, you will usually go to a special X-ray room. The body area to be X-rayed should be uncovered. You must also remove metal objects such as jewelry or watches beforehand, as they can cause image interference. Areas of the body that are particularly sensitive to radiation are protected from X-rays with a lead apron or shield.

Depending on which part of your body is to be X-rayed, you will stand, sit or lie between the X-ray tube that emits the radiation and the X-ray film during the examination. Sometimes small plates with markings are placed next to the body part in question before the image is taken. These provide us with information about the direction of the radiation and the part of the body being X-rayed when we analyze the X-ray image later. X-ray images from different angles of incidence are usually necessary for an accurate diagnosis. You may therefore have to adopt different positions for the recordings.

The actual X-ray scan only takes a few seconds. It is important that you do not move during this time. You may also have to hold your breath for a moment. Otherwise the X-ray image may be blurred. After the examination, the doctor assesses the X-ray images.

Areas of application: When is X-ray examination used?

With the help of an X-ray examination, the doctor can detect possible changes, illnesses or injuries in various parts of the body.

• X-ray of the head: An X-ray can provide information on whether there are injuries, bone fractures or malignant diseases in the head and neck area. The same applies to diseases of the paranasal sinuses, such as suppurations or malformations. X-rays are also frequently used to examine teeth for tooth positions, tooth structures (such as wisdom teeth) or root inflammation. In infants, the condition of the natural skull openings (fontanelles) can be assessed.
• Chest X-ray: An X-ray of the chest (thorax) is necessary for many diseases. For example, heart disease, pericardial effusion and inflammation can be detected on an X-ray. Signs of lung disease such as tuberculosis, lung cancer or emphysema can also be clarified using this method. The doctor can also assess the condition of the blood vessels, such as the aorta, and see malformations or bulges in the vessels (aneurysms) or blockages due to hardening of the arteries (arteriosclerosis). In the area of the ribs, fractures, changes due to osteoporosis or ankylosing spondylitis can be assessed. An “X-ray thorax” is often routinely performed on older people before an operation.
• X-ray of the abdominal cavity: An X-ray examination of the abdominal cavity (abdomen) makes various changes visible. In most cases, an X-ray is first taken of the abdomen without contrast medium. For a more precise diagnosis, it is sometimes necessary to take a further image after administering a contrast medium. This makes it easier to assess the intestinal passage, for example. X-rays also allow a more precise examination of the kidneys and urinary tract. This enables the doctor to diagnose large kidney stones as well as kidney malformations or tumors.
• X-ray of vessels: Arteries, veins and lymphatic vessels are part of the body’s vascular system. Arteries and veins can be visualized with a contrast agent using angiography. Arteries carry blood away from the heart, veins transport it back to the heart. Angiography provides information about possible arterial occlusions or constrictions due to hardening of the arteries (arteriosclerosis). It also allows an assessment of the venous valves, which are designed to prevent the backflow of blood, and possible vascular occlusions (thrombi).
• X-ray of the musculoskeletal system: An X-ray is often used to detect changes or diseases of bones and joints. These include bone fractures, deformities, bone loss (osteoporosis), joint wear and tear (osteoarthritis) or rheumatic joint changes.
• X-ray of the female breast: The X-ray of the female breast (mamma) is one of the special forms of examination. Mammography uses a special device that works with “softer” X-rays and detects tiny calcifications in the breast tissue. These may indicate the presence of breast cancer. Mammography can thus help to detect malignant breast tumors at an early stage and treat them successfully. Mammography therefore plays an important role in the early detection of breast cancer.
• X-ray for foreign bodies: In addition to diseases, foreign bodies that have penetrated the body can also be detected in the X-ray image. These include, for example, swallowed objects or food remains such as bones or fish bones, as well as ammunition resulting from gunshot wounds. If the foreign bodies are not sufficiently visible in the normal X-ray image, special tomography scans such as computed tomography (CT) or magnetic resonance imaging (MRI) can also be performed.

X-ray examination: advantages and risks

An X-ray examination has numerous advantages. These include:

• X-rays can be used to assess numerous diseases, injuries and changes in organs and tissues.
• Dense or solid tissue such as bone is more visible with X-rays than with other methods.
• The X-ray does not cause any pain.
• The method delivers a quick result and is available almost everywhere.
• In the case of a simple X-ray (e.g. for a broken leg), the radiation exposure is relatively low.
• Modern (digital) devices manage with ever lower radiation intensity.

However, X-raying is also associated with some risks:

• X-rays are rich in energy. Part of the energy is transferred to the body during the X-ray. This can damage the cells and genetic material (DNA) if X-rays are taken frequently. In the long term, this can increase the risk of cancer.
• Each additional X-ray examination increases the body’s exposure to radiation.
• It is hardly possible to specify an exact limit value above which X-rays are harmful.
• Unborn babies are particularly susceptible to radiation exposure during organ development. X-rays during pregnancy are therefore only useful and permitted in individual cases. Alternatively, other imaging procedures such as ultrasound (sonography) or magnetic resonance imaging (MRI) are suitable.
• In rare cases, allergic reactions to X-ray contrast media may occur.

Conclusion: Always weigh up with your doctor whether an X-ray examination is necessary and sensible in your case. When used appropriately, the benefits often outweigh the potential risks. You should also have an X-ray passport issued. Each examination is noted here with the date and irradiated body part. This helps to avoid unnecessary X-rays and thus additional radiation exposure.