Diagnostic Work-Up

X-ray images are basically photographs, but they are taken with X-rays instead of light rays. Moreover, it is not the light reflected (reflected back) from the object that is imaged on the film, but the X-rays that penetrate the object. Soft tissue weakens (absorbs and scatters) X-rays very little, air almost not at all, so these areas will be dark in the image. Bones, on the other hand, which contain a lot of calcium, attenuate X-rays strongly, i.e., less light passes through them and this produces bright areas in the image. Therefore, X-rays are good for imaging bones, but only as two-dimensional projections of what are actually three-dimensional structures. Therefore, overlays of multiple bones can complicate interpretation. This problem does not occur with the 3D images achieved with computed tomography. X-rays are poor when it comes to assessing soft tissue structures.

Depending on the type of X-ray, the radiation exposure is about 0.1 to 5 mSv (milli Sievert). The natural annual radiation exposure in Germany is 1 - 4 mSv. In contrast, tumor irradiation (radiation therapy) involves 60,000 to 80,000 mSv. In children, adolescents and younger adults, any radiation exposure should be avoided and an MRI (magnetic resonance imaging) should be taken rather than an X-ray, because an MRI is done completely without radiation exposure. In older people, the long-term risk associated with the radiation exposure of an X-ray is considered lower, but radiation exposure should still be kept as low as reasonably achievable.

An MRI - magnetic resonance imaging or nuclear magnetic resonance - is an imaging technology used in diagnostics to image the human body. To produce images, MRI uses the interaction of protons (nuclei of hydrogen atoms) with magnetic fields and radio frequency fields. It works without high-energy ionizing radiation (e.g., X-rays). MRI can therefore be used in patients of any age and even during pregnancy. MRI can be used in a variety of ways with different imaging techniques, known as "pulse sequences." In contrast to computed tomography (CT), it provides a wide range of tissue contrasts, including soft tissue. In this way, organs and tissues can be examined for different structural and functional characteristics, e.g. for inflammation or cancer.

MRI (Magnetic Resonance Imaging) can show a very wide range of tissues and organs of the body in three dimensions, with high resolution and multiple tissue contrast. In recent decades, it has become one of the most important diagnostic methods in medicine. It can image the brain, abdominal organs, bones, vessels, the heart and nerves, and it can help to differentiate between benign processes and malignant tumors and to detect inflammation, stroke and myocardial infarction. Functional MRI is used to visualize brain activity.

Air and calcification are poorly visible on an MRI. Although special MRI sequences (techniques) can also image air and calcification, MRI is primarily suited for imaging tissues containing water and fat - which are almost all tissues and organs in the body. Even bones, which contain high levels of calcium salts (calcium hydroxylapatite), can be imaged with MRI because they also contain water and fat.

For many diseases involving changes in tissues and organs, MRI (magnetic resonance imaging - nuclear magnetic resonance) can provide more detailed information than conventional diagnostic procedures. While doctors still use X-rays to examine bones, joints and the spine due to their widespread availability, MRI is frequently the method of choice today for these indications. It can show disease at an early stage and its extent, including, for example, articular cartilage, ligaments, muscles and tendons, and inflammation that may be associated with pain - diagnostic information that X-rays do not provide. MRI can also provide more comprehensive information than ultrasound in many applications, such as examining the thyroid, heart, abdominal organs, female breast, bladder, prostate, vessels and soft tissues. In addition, MRI does not use X-rays. Which examination is appropriate should be decided individually with your treating physician.

MRI (magnetic resonance imaging - nuclear magnetic resonance) does not use any ionizing radiation - radiation that, due to its high energy, can cause radiation damage to cells and their genetic material. These include X-rays, but also gamma rays, which are produced during radioactive decay. Radioactive decay plays a role in radionuclides used in nuclear medicine. But not in MRI. MRI contrast media are not radioactive, unlike the radiopharmaceuticals used in nuclear medicine. Like any medicinal product, however, they can cause side effects and are used only after an individual risk-benefit assessment.

Whole-body MRI can cover a wide range of body regions in a single examination, because MRI (magnetic resonance imaging - nuclear magnetic resonance) is a versatile examination method that can be used to examine the entire body in detail. A whole-body MRI examination (whole-body scan) can provide information about the following organs and disease groups:

• Stroke, dementia, brain tumors, inflammatory brain diseases, etc.
• Degenerative and inflammatory changes of the spine, joints, tendons and ligaments, etc.
• Whole body staging for bone metastases - studies have reported higher sensitivity and specificity than bone scintigraphy.
• Malignancies/tumors/cancer of the lymphatic system, thyroid, lung, liver, pancreas, kidneys, spleen, colon, uterus, prostate, bone, etc.

Whole-body MRI does not use ionizing radiation, unlike computed tomography (CT) and nuclear medicine methods (bone scintigraphy and PET). Compared to an ultrasound (US) scan, whole-body MRI has the advantage of being able to image the entire body and all organs: Ultrasound cannot image the brain, spine, lungs, intestines, and many other important body structures. At ANOVA IRM, whole-body MRI is part of the anti-ageing programme.

CT (computed tomography) is the oldest medical cross-sectional imaging technique. Like MRI (magnetic resonance imaging), it was invented in Great Britain. It was the first procedure in medical history to allow direct, cross-sectional imaging of the brain. CT uses X-rays to image the tissues, just as they are used in X-ray images. Tissue contrast is therefore lower compared to MRI (magnetic resonance imaging - nuclear magnetic resonance), so contrast agents administered intravenously and orally play an important role in CT.

Modern computed tomography scanners can image the human body three-dimensionally in a few seconds at submillimeter resolution. They are therefore used in modern emergency medicine, e.g. for accident victims, to detect damage such as bone fractures, bleeding, organ and vascular injuries, lung damage, brain injuries, etc. throughout the body within a very short time - in just one examination. In addition, CT can also be used to examine the lungs, vessels, coronary arteries, and even the intestines, as in an endoscopy. Bones and joints, even endoprostheses can be depicted three-dimensionally with high resolution and detail, with much higher diagnostic significance than through the conventional two-dimensional projection images of the X-ray era.

Computed tomography images the electron density of tissues. Unlike x-rays, which are projection images, CT images the body in cross-sections (axial slices) that are typically 1 - 10 mm thick. Because soft tissues (e.g., the abdomen) do not differ significantly in electron density, CT can image soft tissues, but without good contrast. Bones, due to their calcium content, have a higher electron density than soft tissues, and air, e.g., in the lungs, which has a very low electron density, image with good contrast on CT compared to soft tissues. Due to the low contrast that different soft tissues exhibit on CT, contrast agents are often used in CT examinations that, when applied either through the vascular system or through the intestines, allow for better contrasting and differentiation of different tissues and organs on CT.

Soft tissues such as the abdomen are difficult to image on CT. Without contrast, most soft tissues show up on CT scans only as gray on gray. For imaging soft tissues and organs, MRI (magnetic resonance imaging) is far superior to CT.

The most important applications of computed tomography are:

• Imaging of the lungs
• Imaging of larger sections of the body in severely injured patients
• Examination of the abdominal and pelvic organs in the elderly

Special CT examinations:

• Imaging of the coronary arteries to assess the risk of coronary heart disease (calcium scoring) or to assess the coronary arteries (CT coronary angiography).
• Examination of the colon as part of colon cancer screening without an endoscope (virtual colonoscopy)
• Lung cancer screening in smokers (low-dose CT of the lung)

At ANOVA IRM, CT is also used to guide applications, for example into the cerebrospinal fluid or the lumbar spine.

No. In a CT, X-rays emitted from an X-ray source (X-ray generator) are passed through the object to be imaged in a sharply focused beam, and attenuated depending on the electron density of the tissues. No radioactive substance is used.

Radioactivity is the decay of unstable atomic nuclei, which in the process emit energy in the form of high-energy rays (gamma rays, X-rays) or through the emission of particles (particles, fragments of atomic nuclei). β-"rays" are electrons, α-rays helium nuclei. However, the emission of positrons, neutrons, and neutrinos is also a component of radioactivity.

PET stands for positron emission tomography. PET is a nuclear medical examination procedure in which so-called radioligands are used that bind more or less specifically to certain cells and receptors and can thus detect changes in the body with high specificity. A radioligand in turn consists of a molecule, the ligand, which binds to a receptor or is metabolized, and a radioactive atom, often fluorine-18 or gallium-68, which is bound to the ligand. The radioactive atom decays to emit a positron, which decays into two gamma quanta that are registered in the PET scanner's detector and used to calculate the PET images.

A PET scan is a functional examination. It shows the distribution of metabolic processes or receptors in the body that are more or less specific to certain tissues. For example, most malignant tumors have increased sugar metabolism, which can be detected with the radioligand 18Fluoro-Deoxy-Glucose (18FDG). In prostate cancer, PET exploits the increased density of prostate specific membrane antigen (PSMA) receptors on prostate cancer cells. A Ga68-PSMA radioligand docks onto these receptors, allowing relatively specific detection of prostate cancer. Specific PET radioligands can be produced radiochemically for many other pathological changes in the body.

Anatomical details are poorly imaged on positron emission tomography scans because PET is a functional imaging modality. Therefore, PET is now usually combined with computed tomography (CT) (PET/CT combination scanner). CT images anatomical details so that PET data can be matched anatomically.

There are many indications for positron emission tomography. The most important applications are in the diagnosis of malignant tumors (cancer) and in the diagnosis of diseases of the brain. Depending on the indication, PET uses different radionuclides and ligands that bind more or less specifically to certain cells and receptors and can thus detect changes in the body with high specificity.

Main applications for PET:

• 18Fluoro-deoxy-glucose-PET: whole-body staging (detection of metastases) in malignant tumors, e.g. lung cancer, colon cancer, etc.
• 68Gallium-PSMA (prostate specific membrane antigen)-PET: staging of prostate cancer, detection of local recurrence after prostatectomy and radiotherapy.

A positron emission tomography - PET scan - is not radioactive per se, but the drug/contrast agent used for imaging is radioactive. It consists of a so-called radioligand that binds to specific structures in the patient's body or is metabolized by cells. Bound to this radioligand is a radioactive atom, which emits other high-energy particles and radiation in addition to a positron (hence the name) during radioactive decay. The positron itself decays into two high-energy photons, which are registered by the PET scanner's detector and from which the PET image is calculated. So, in colloquial terms, you could say that a PET scan is "radioactive." The radiation exposure for the patient is roughly 10 mSv. The natural annual radiation exposure is about 1 - 4 mSv.

A scintigram or a scintigraphy is a nuclear medicine examination method in which different radio-pharmaceuticals and nuclides are used to image organs and their function. The best known are bone scintigraphy and thyroid scintigraphy, as well as cardiac and renal function scintigraphy. Bone scintigraphy utilizes the attachment of technetium99m-labeled bisphosphonates to bone. This is particularly pronounced where remodeling processes occur in the bone, such as in inflammation or when the bone is altered by tumors or metastases. In older people, in whom wear-related remodeling processes in joints and the spine are common, the detection of bone metastases by skeletal scintigraphy is more difficult because both metastases and the wear processes absorb the radio-pharmaceutical. Therefore, whole-body MRI has been providing better results in finding bone metastases for about 10 years.

Depending on the radio-pharmaceutical used, scintigraphy can show changes in the thyroid gland, e.g. thyroid nodules, inflammation and degenerative changes in the musculoskeletal system and bone metastases, circulatory disorders in the heart muscle, kidney dysfunction and other pathologic changes. In this context, scintigraphy, like all nuclear medicine examinations, provides more functional information than anatomical information, since the spatial resolution in scintigraphy is much poorer than in computed tomography (CT) and magnetic resonance imaging (MRI).

As often as is medically necessary, based on an individual risk-benefit assessment. Its radiation exposure is 1 - 10 mSv, depending on the application. The natural annual radiation exposure is between 0.5 and 20 mSv. As with any medical examination, the potential benefit of the examination must be weighed against the potential harm. To reduce radiation exposure, MRI (magnetic resonance imaging, nuclear magnetic resonance) can now be used in many cases, especially in younger people, often with more comprehensive and specific results.

Radioactivity describes the decay of atoms by emitting high-energy radiation or particles. The corresponding unstable atoms are called radioactive. In medicine, radioactive atoms are used for imaging in the field of nuclear medicine. The corresponding nuclear medicine imaging techniques are scintigraphy with gamma cameras, SPECT (single photon emission computed tomography) and PET (positron emission tomography). They are primarily used for the diagnosis of the thyroid gland, the heart, the kidneys, the skeletal system and for the detection of tumors in the body.

Osteoarthritis usually makes itself felt through pain and restricted movement in joints and the spine. However, by the time osteoarthritis becomes symptomatic, it has usually progressed considerably and the joint cartilage and bone structures are usually irreparably damaged. Surprisingly, early detection tests for osteoarthritis do not yet exist, although this disease affects almost everyone in old age and leads to considerable limitations in quality of life. Early detection is relevant because the options that can be discussed with a patient differ depending on the stage of the disease. Whether cell-based approaches can influence cartilage damage at an early stage is currently being investigated in laboratory research and early clinical studies; a reliable regenerative effect in patients has not been established. MRI of the joints and spine is the imaging method that shows the relevant structures, including the articular cartilage and the intervertebral discs. These cannot be seen on X-rays.

Many. Generally, CT (computed tomography), MRI (magnetic resonance imaging, nuclear magnetic resonance), and PET (positron emission tomography) are appropriate for finding metastases in the abdomen, depending on the specific question. Ultrasound examinations are also frequently used; for this question their informative value is more limited than that of CT, MRI and PET, but they are widely available. Metastases in the lungs are usually detected by CT, very specifically by PET. MRI has been used less frequently for the lung.

Many. The oldest procedure is X-ray, which is still occasionally used. For decades the standard procedure has been bone or skeletal scintigraphy with technetium 99m labeled bisphosphonates. However, skeletal scintigraphy also shows degenerative bone changes, which can then be mistaken for metastases and must be further clarified by other imaging techniques.

For this reason, studies over the past 15-20 years have reported higher sensitivity and specificity for whole-body MRI than for bone scintigraphy in detecting bone metastases; whole-body MRI also shows lymph nodes and organ metastases that are not visualized by bone scintigraphy. Therefore, when staging with skeletal scintigraphy, computed tomography (CT) is usually still performed, along with 10 - 20 mSv of radiation exposure. MRI is radiation-free.

Recently, positron emission tomography (PET) with 18fluoro-deoxyglucose and, for prostate cancer, with gallium 68 PSMA (prostate specific membrane antigen) in combination with computed tomography (CT) in a combination device - PET/CT - has gained acceptance because studies have reported high detection sensitivity and specificity, particularly for lymph node metastases.

In Germany, medical services are billed according to GOÄ. An MRI costs between 350 and 1200 euros, depending on the effort involved and the region examined.

The contrast agent for an MRI examination costs between 50 and 200 euros. In addition, the injection with a high-pressure syringe is charged, and if necessary, special evaluations of the contrast medium dynamics. If necessary, several contrast agents are used at the same time. In general, it can be said that the use of contrast agent makes the MRI examination more expensive by about 100 - 120 euros.

A whole body scan costs between 1200 and 1500 Euro, depending on the effort. In certain cases, e.g. when multiple administration of contrast medium is necessary, e.g. when MR angiography and contrast medium dynamics are required, e.g. for the examination of the female breast, it may also be that the whole body scan has to be performed over two days. The costs can then rise to approx. 2000 - 2500 Euros. However, this is still much cheaper than if all body regions are examined individually and each is billed separately according to GOÄ.