Nuclear Medicine

Our practice has been active in the medical specialty of nuclear medicine for more than 50 years as Dr. med Müller-Miny founded the first institute for nuclear medicine in Düsseldorf in 1957. Since then, our practice has continuously provided comprehensive nuclear medical diagnostics to patients in the region.

In 2008, we opened an expanded, completely renewed nuclear medicine department, updated according to current rules and regulations and featuring state-of-the-art equipment.

Our nuclear medicine services include:

• Myocardial scintigraphy
• Brain scintigraphy
• Thyroid diagnostics
• Ventilation and perfusion lung scintigraphy
• Skeletal scintigraphy
• Bone marrow scintigraphy
• Nuclear medicine renal studies (isotope nephrograms)
• Liver and spleen scintigraphy
• Lymph node scintigraphy
• Salivary gland scintigraphy

In nuclear medicine, diseases and dysfunctions of organs are diagnosed or treated by means of radioactive substances. Thus, the field of nuclear medicine is divided into diagnostic and a therapeutic sections:

Diagnostic nuclear medicine involves functional imaging of all organ systems of the human body, whereas therapeutic nuclear medicine represents the treatment of the human organ systems by means of radiopharmaceuticals.

The dosage is chosen so that an injury to the patient is ruled out; in comparison to other diagnostic or therapeutic procedures, nuclear medicine treatment is much better tolerated by the patient.

Diagnostics

Nuclear medicine offers a variety of diagnostic opportunities. The so-called scintigraphy uses a gamma camera, and prior to the examination a radioactive substance is administered intravenously. The substances used are manufactured individually for every patient, and they will decay if they are not used.
For this reason, it is important that the patient comes to the examination date as agreed or gives timely notice if the examination can’t take place.

Before exposures can be taken, the organ or area to be investigated has to absorb the substance; this can result in several hours of waiting.

The gamma camera is able to locate the outgoing radiation and provide an image record. For this purpose, the radiation is converted into light pulses using a crystal (so-called scintillation effect, hence the name “scintigraphy”).

Below, we have briefly outlined the five most common nuclear medical diagnostic procedures:


1. Thyroid scintigraphy

Patients with thyroid changes may have so-called cold or hot nodules. The terms cold or hot refer to a reduced or increased thyroid function compared with the surrounding thyroid tissue.

Cold thyroid nodules should be monitored and possibly punctured as malignant changes can often be found in them. When punctured, a procedure usually controlled by ultrasound, tissue is obtained with a thin needle and examined by a pathologist. Today, even malignant thyroid changes have a very high cure rate.

Hot thyroid nodules lead to hyperthyroidism, which is usually recognizable by the patient’s nervousness and tachycardia. Also hair loss, diarrhea, and heat intolerance are commonly encountered. If the nodules are not too large, they can be destroyed by radioiodine while surgery is needed for larger nodules. With radioiodine therapy, the patient swallows a capsule of radioactive iodine, which arrives in the nodule, and the radiation eliminates the nodule without much harm to the patient. Graves’ hyperthyroidism is a special form of hyperthyroidism where the thyroid gland is usually free of nodules and the entire thyroid shows hyperfunction. In the scintigram, the percentage applied to the recording material, the so-called uptake, shows if the thyroid gland has an increased storage level. This type of hyperthyroidism is initially treated with medication for more than a year. If the hyperfunction still exists one year after medication has been discontinued, a radioiodine therapy will be applied to smaller thyroid glands, and surgery is used for a larger thyroid gland.


2. Bone scintigraphy

Hier wird die Knochenstoffwechselaktivität „markiert” bzw. dargestellt.

With bone scintigraphy, the metabolic activity of the bone is marked or displayed. The metabolism of the bone may increase when there are bone fractures or changes due to inflammation or tumors. It is therefore possible to search for such changes using bone scintigraphy; physicians will most commonly try to check if metastasis exists.

Since significant proportions of the substance will reach the bone only after several hours, approximately three hours will elapse between the injection of the substance and the actual imaging. The examination itself may take another hour if the entire body is being examined.


3. Myocardial scintigraphy

In patients with coronary artery disease, the coronary arteries have become narrow, resulting in a decreased myocardial perfusion. If the patient is injected with a substance that is deposited in the heart muscle, accumulation of the substance will be lower in the areas with a coronary vessel constriction. The physician may be able to detect these areas using a gamma camera.

With some patients, a lower accumulation may only be detectable during physical exercise, which is why bicycle ergometry is often required.

The gamma camera records not only from one direction; it can also rotate around the patient (so-called SPECT study).


4. Renal scintigraphy

To determine the renal function, physicians make use of renal scintigraphy or, more precisely, the radioisotope nephrogram (RNG).

The patient is given a radioactive substance (with intravenous injection), which accumulates in the kidneys and is excreted through the kidneys into the ureter and the bladder. The speed of the accumulation and the exit can be measured using a gamma camera, and the renal function (so-called clearance) can be calculated.

In patients with high blood pressure (hypertension), the blood pressure can be caused by a constriction of the renal artery. After an RNG-based investigation, the patient is administered a special blood-pressure-lowering agent (Captopril®) in tablet form after which the examination will be repeated in order to prove that renal artery stenosis is the cause of the patient’s hypertension. If the renal function worsens on one side, a functionally effective renal artery stenosis has been proven.


5. Lung scintigraphy

Lung scintigraphy is applied to patients suspected of having pulmonary embolism, usually the result of a deep vein thrombosis, that is, blood clots deposited in the veins of the leg. If parts of these clots are torn away and transported with the blood flow through the heart into the pulmonary arteries, lung embolism emerges, which may lead to death depending on the size of the embolism. An early diagnosis of the first, smaller embolisms is therefore essential in order to heal the disease through the administration of a coagulation-inhibiting agent. In our practice, we use both lung inhalation scintigraphy and lung perfusion scintigraphy.

With the lung inhalation scintigraphy, our physicians check the ventilation of the lungs by having the patient inhale a radioactive gas or, more accurately, radioactive particles. With the lung perfusion scintigraphy, the physician measures the lung perfusion after giving an intravenous dose of a radioactive substance.

The comparison of the accumulation pattern of lung inhalation and lung perfusion scintigraphy will confirm or rule out a suspected embolism.