INFORMATION FOR PATIENTS
In Vivo diagnostics
Principle of examination
Types of examinations
Perfusion scintigraphy of myocardium stress and resting by gated SPECT method – after intravenous administration of radiopharmaceutical its uptake by myocardial cells occurs. The uptake is directly proportional to the perfusion in the myocardial area at the time of application. Accumulation of the radiopharmaceutical does not occur in necrotic or scarred areas of the myocardium. In ischaemic areas, accumulation is reduced. The examination is performed in two phases, first a stress phase and then a rest phase. Their comparison evaluates the presence of reversible or fixed defects of radiopharmaceutical accumulation. These are indicative of ischaemic or necrotic deposits in the myocardium or postinfarction scarring.
Radionuclide ventriculography (MUGA scan) – imaging of the cardiac cavities using circulating labelled autologous erythrocytes in the bloodstream. Quantification of the recording makes it possible to determine the ejection fraction of the left ventricle, the ejection fraction of the right ventricle.
Dynamic scitigraphy of the kidneys – the method allows for a functional-morphological examination of the kidneys. On the basis of the administered RAF, perfusion, filtration and excretion into the hollow system are monitored, outflow parameters, separated renal function (the share of the left and right kidneys in the total function) and total glomerular filtration are assessed.
Static renal scintigraphy ( + SPECT) – RAF is accumulated and fixed for a certain period of time in the cells of the proximal tubules of the kidneys depending on their functional status, which allows to visualize the state of the functional renal parenchyma, to assess the localization, shape and size of the kidneys, to calculate the separated function and to detect focal lesions.
Dynamic renal scintigraphy with captopril test – the examination is indicated in patients with hemodynamically significant stenosis of the renal artery or its branch with probable renovascular hypertension. The principle of the examination is to compare the parameters evaluated during dynamic renal gammagraphy performed after ACEI administration (captopril study) and those obtained under basal conditions (basal study). The examination is performed on 2-fold. The captopril study is performed first. If the captopril study is negative, the likelihood that the patient has renovascular hypertension is low and there is no need to perform a basal study. If pathological findings are found, the study is repeated without administration of captopril.
Dynamic renal scintigraphy with furosemide test – intravenous application of furosemide during dynamic renal scintigraphy is used to monitor the renal response to its administration. In non-obstructive hydronephrosis, there is a runoff of retinated urine and a decrease in the renographic curve after administration of furosemide (a diuretic).
Whole-body scintigraphy of the skeleton, three-phase scintigraphy of a part of the skeleton, SPECT of a part of the skeleton – the distribution of osteotropic RAF in the skeleton, which accumulates to an increased extent in areas with high metabolic activity, is displayed… The examination has a high sensitivity, but low specificity.
Perfusion scintigraphy of soft tissues – The examination is used for detection of focal processes in soft tissues (muscles, joints) and for determination of their metabolic activity. Radioactive pertechnenate (99mTc O4- ) accumulates at an increased rate in areas of hyperaemia and with increased metabolic activity.
Thyroid scintigraphy – administered pertechnetate (99mTc O4- ) accumulates in the thyroid gland (Tg). Scintigraphy of the thyroid gland provides a functional-morphological image of the thyroid tissue, its size, shape and localization are assessed; it allows detection of foci with reduced accumulation (cold nodes – cysts, tumors…), or foci with increased accumulation of RAF (warm nodes -hyperfunctional tissue).
Parathyroid scintigraphy – RAF that accumulates in the parathyroid glands also accumulates in the thyroid gland. Therefore, subtraction or biphasic scintigraphy is used. In the subtraction method, 99mTc-Myoview is first applied, after 20 min the thyroid gland is scanned together with the parathyroid glands, then pertechnetate is applied, and after 15 min the parathyroid gland is scanned. The thyroid gland is imaged; subtraction of the images yields an image of the parathyroid glands (if enlarged); biphasic scintigraphy takes advantage of the observation that 99mTc-Myoview is more rapidly cleared from thyroid tissue than from hyperplastic tissue or parathyroid adenoma. Acquisition images are obtained at 20-30 min and then at approximately 2 h after RAF application.
Scintigraphy of endocrine and neuroendocrine tumors and tumors arising from the neural tube – The radiopharmaceutical 123I-MIBG (noradrenaline analogue) accumulates in catecholamine secretory granules of neuroendocrine tissues. Omni-radiation is indicated in suspected adrenal medullary hyperplasia, pheochromocytoma/paraganglioma, malignant pheochromocytoma, neuroblastoma, medul. thyroid carcinoma, and others. 99mTc – Tektrotyd is used to image GEP tumors with increased density of somatostatin receptors.
Cholescintigraphy – the examination allows to evaluate the hepatobiliary system, the patency of the bile ducts and the function of the gallbladder; it provides information about the size, shape and location of the liver, the location and size of the gallbladder and the morphology of the bile ducts… The administered RAF is taken up by the hepatocytes and its excretion into the bile ducts and its passage through the ductus choledochus into the duodenum is monitored. To stimulate gallbladder emptying, a fatty diet (dark chocolate, cheese) is given during the examination. If necessary, a static scan is performed in 2-4 hours.
Static scintigraphy of the liver and spleen ( + SPECT) – The administered RAF is taken up by Kupffer cells in the liver (reticuloendothelial system – RES). RES cells phagocytose labelled radionuclides. Due to the presence of RES cells also in the spleen, we obtain an image of the liver together with the spleen. To assess changes in size, shape and distribution of activity, we obtain 5 projections, which allow us to evaluate the liver/spleen activity ratio, their length, cold foci (hyperplastic nodules, fibrous tissue), sites of increased activity….
Scintigraphy of Meckel’s diverticulum – Meckel’s diverticulum is a relatively common malformation, occurring in about 2% of the population. In 20%, it contains functional ectopic gastric mucosa that uptakes the radiopharmaceutical 99mTc O4- and can be visualized gammagraphically (localized increase in activity).
Salivary gland scintigraphy – this is a functional and morphological examination of the salivary glands based on their ability to uptake 99mTc O4- from the bloodstream. It is performed as a dynamic study during which lemon juice is orally administered to stimulate salivary secretion.
After intradermal application into the interstitial space of the lower or upper limb, the radioactive colloid is transported by lymphatic vessels to the lymph nodes, which allows imaging of the lymphatic system in the respective catchment area (retroperitoneal, axillary, cervical, parasternal or iliopelvic). We take static images at rest and afterload (gesture: most commonly walking).
Sentinel node evidence – the sentinel lymph node is the first sentinel lymph node to receive lymphatic drainage directly from the tumor. The aim of this method is to determine the number and location of these nodes. Subsequently, an operative biopsy and histology are performed. If the sentinel lymph node does not contain metastatic cells, the other LUs in the catchment area do not have them either. The examination is mainly used in malignant melanoma and breast cancer. It is also used in cervical cancer. The sentinel lymph node is demonstrated peroperatively using a special probe, therefore, possession of this probe at the time of surgery is a prerequisite for performing this examination.
Scintigraphic imaging of dopamine transporters in the basal ganglia (striatum) of the brain is evaluated using 123I-labeled ioflupane : 123I-FP-CIT ( DaTSCAN ©). Prior to the examination, we block the accumulation of free 123I in the thyroid gland by administering perchlorate. After i.v. application of DaTSCAN© (usually 185 MBq), the injected substance accumulates in the striatum for about 3-4 hours. This is followed by a SPECT scan of the brain lasting about 45 minutes. The patient lies motionless on his back. The scintigram is assessed visually, quantitatively or semi-quantitatively using ROI techniques for the nucleus caudatus and putamen. The indication is the differential diagnosis of movement disorders with deficit (Parkinson’s disease, parkinsonian symdromes) and without dopamine transporter deficit ( mainly essential tremor).