Summary The measurement of blood flow in various organs and its visual presentation in parametric images is a major application in nuclear medicine. The purpose of this paper is to summarize the most important nuclear medicine procedures used to quantify regional blood flow. Starting with the first concepts introduced by Fick and later by Kety-Schmidt the basic principles of measuring global and regional cerebral blood are discussed and their relationships are explained. Different applications and modifications realized first in PET- and later in SPECT-studies of the brain and other organs are described. The permeability and the extraction of the different radiopharmaceuticals are considered. Finally some important instrumental implications are compared.
ZusammenfassungBestätigung und Ausschluß benigner fokaler Leberläsionen sind Hauptaufgabe der nuklearmedizinischen Leberdiagnostik. Es stehen die hepatobiliäre Sequenzszintigraphie (fokale noduläre Hyperplasie, Adenom) und die Blutpoolszintigraphie (Hämangiom), in Einzelfällen die Kolloidszintigraphie im Vordergrund. Neuere Untersuchungsverfahren wie die Rezeptorszintigraphie mit Octreopeptiden, die Immunszintigraphie mit monoklonalen Antikörpern und die 18FDG-Untersuchungen mit PET und Gammakamera sind besonderen Fragestellungen, besonders in der Onkologie, Vorbehalten. Für eine erfolgversprechende artdiagnostische Einstufung fokaler Leberläsionen sind ein schrittweises diagnostisches Vorgehen und umfassende Kenntnisse der Indikationen weiterführender diagnostischer Verfahren erforderlich.
Opportunistic pneumonias are a life-threatening complication in patients with AIDS. Early diagnosis and therapy is necessary to improve prognosis. This study was designed to assess the value of 67Ga scintigraphy in the primary detection and follow-up of these special pneumonias. 67Ga scintigraphy was performed in 40 patients: 10 normal controls and 30 HIV-positive patients with AIDS or AIDS-related complex (ARC). 67Ga scan results were compared with current chest radiographs and the results of pathogen detection. The evaluation of positive scans was based on a quantification of the pulmonary uptake, expressed as a pulmonary/soft-tissue uptake ratio. Only 8/30 patients had a normal scan, 22/30 showed diffuse (13/22) or focal (9/22) increases of pulmonary uptake. In 7/8 patients with normal scans the chest radiograph was negative as well. The one patient with negative scan but positive chest radiograph had pulmonary Kaposi’s sarcoma. In 11/22 patients the 67Ga scan and chest radiograph were positive simultaneously. In the other 11/22 patients with positive scans chest radiographs were initially negative but showed pathology in 5 cases within 1-2 weeks. The reason for positive scans in most cases was an opportunistic lung infection; other forms of pneumonia were only observed in two cases. The defined uptake ratio demonstrated to be a highly sensitive parameter for monitoring pneumonia and the effects of therapy in follow-up studies. In conclusion, quantitative 67Ga scintigraphy proved to be a reliable and highly sensitive method for primary detection and follow-up of opportunistic pneumonias in patients with AIDS.
Thirtyeight patients with suspected thrombosis in the legs were investigated scintigraphically using 99mTc-tripolyphosphate. The ratio between the activity in the leg with suspected thrombosis and the other leg was calculated. The results were compared with those obtained with phlebography. A pathologically high activity ratio was found in all but one of the 18 patients in whom phlebography showed a thrombus. The ratio was normal in 13 of the 20 patients with normal phlebographic findings. The possible use of the method described as a postoperative screening test is discussed.
SummaryIn patients with ischemic heart disease the evaluation of regional myocardial perfusion by 133Xenon intra-coronary injection using a gamma camera computer system allows the detection of regional alterations of myocardial perfusion. While at rest a minority of the patients studied shows large alterations, during pacing induced angina a severe reduction of regional myocardial perfusion can be evidenced both in initial distribution scintigrams, when the injection is performed during angina, and on the washout curves when angina is induced immediately after the injection, during the course of the washout.
Results are reported of quantitative adrenal scintigraphy with 131I-cholesterol in 8 patients with normal adrenal function before and after ACTH-stimulation and cortisol-suppression respectively, in one case with an adrenal metastasis from a pulmonary cancer, in two cases with Cushing's disease and in 7 cases with Conn's disease. In normal cases and in patients with M. Cushing a diagnosis of adrenal cortical function is possible with this method but can usually be replaced by more specific biochemical studies of serum and urine. The scintigraphic method is in addition of value in localization studies and can in unequivocal cases replace the selective adrenal phlebography. In patients with M. Conn increased uptake values (bilateral adrenal cortex hyperplasia) as well as reduced or non-detectable uptakes were observed, one of these cases suffering from a cortex carcinoma with M. Conn.
SummaryThis case report demonstrates an hepatic amebic abscess by scintigraphy, utilizing a new radiopharmaceutical designed specifically for that purpose. The abscess is delineated as a positive lesion after twenty four hours. The agent, 131I-labeled bromometronida-zole, may prove to be specific for the diagnosis of these abscesses.
Summary25 patients with known cerebral disease (either CVA’s or primary or secondary tumours) diagnosed by clinical and angiographic criteria were submitted to a double siotope imaging technique using 99mTcO4 – and 99mTc-EHDP.The different biological behaviour of these radiopharmaceuticals has provided specific and differential diagnosis between vascular and neoplastic disease of the brain. 99mTc-EHDP is shown to be the tracer of choice for the imaging of CVA’s and 99mTcO4 – is confirmed as the tracer of choice for the imaging of primary or secondary tumours in the brain.
In order to analyze cerebral blood flow for diagnostic purposes, Indium 113m-DTPA was i.v. injected into seated patients, and time-activity curves were registered by a multifacet gamma camera (Fucks-Knipping) from 8 regions of interest, from the median area and from the right and left side of the head: 3 from the hemisphere, 3 from the brain stem, 2 from the large arteries of the neck. The results from 14 patients with chronic impairment of cerebral blood flow were compared with normal data from 20 healthy individuals. The time activity curves were analyzed for peak-height, mean transit time, and ratio peak to plateau height. The individual parameters were investigated for the degree of their correlation in a multiparameter system. The results from the patients indicated for the different single parameters a non-uniform response. There was also no correlation between the deviation of different parameters, between single pathological parameters and the degree and the site of blood flow impairment. On the other hand, a positive correlation was found between the number of pathological parameters and the degree of blood flow impairment irrespective of the site of its localization. Reason for this result probably is the variable location and degree of blood flow compensation by collaterals, which predominantly are expected at the cerebral base. The data indicate the potential usefulness of the application of the multiparameter analysis to quantitatively detect the degree of impairment of cerebral blood flow without regard to its topography. In this respect, the method, here described, promises to be of clinical value for non-invasive and non-hazardous diagnostic screening of cerebral blood flow.
Ten healthy volunteers were examined radiospirometrically using 133Xenon in physiologic saline i.v. and with 133Xenon gas inhalation. The measurements were done using a gamma camera (Nuclear Chicago, Pho/Gamma III) in the PA projection in both sitting and supine positions. For evaluation, each lung was divided into three regions: upper, middle, and lower fields. Using a computer (DEC, GAMMA 11), the minute exhalation value, the perfusion and ventilation indices, and the ventilation/perfusion quotient were calculated. In the upright position the ventilation and perfusion indices increase from cranial to caudal. In the horizontal position the regional lung functions tend to equalize. The vital capacity is larger in the vertical position than in the horizontal position, particularly in the right lung. The values are shown in tabular form.
Following operation or/and radioiodine therapy in 69 patients with malignant tumors of the thyroid gland the plasma level of TSH was increased independently of the level of thyroid hormone and of a clinical finding of hypothyroidism. In all cases it was possible to stimulate the secretion of TSH with TRH (p less than 0,0005). Therefore, application of TRH may be helpful to increase the uptake of iodine by metastases. On the other hand substitution of thyroid hormones--thyroxine or triiodothyronine or both combined--resulted in normal levels of TSH and normal response to TRH.
The authors describe a radioisotopic method for the oviduct patency control in patients suffering from primary or secondary sterility. The application of 133Xe causes at least about 3-4 times less radiation than hysterosalpingographical tests. Ease of interpretation facility, painlessness and comparability of the results were noticed.
Using Indium-113m and the Gamma Retina V (Fucks-Knipping Camera), the minimal cardiac transit times (MTTs) were measured radiocardiographically from the right auricle to the aortic root. This analysis served to determine the relation between stroke volume and the segment volume of the part of circulation between the right auricle and the aortic root. In 39 patients with myocardial insufficiency of different clinical degree the effectiveness of digitalization was, up to a period of 5 years, measured by means of the volume relation mentioned above. The following conclusions can be drawn from the results: digitalization of patients with myocardial insufficiency leads to an improvement of the impaired relation of central volumes. In patients with diminished cardiac reserve the improvement is drastic and often results in a nearly complete normalization. The data remain constant during therapy even for an observation period of 5 years. Digitalization of patients with congestive heart failure only leads to a partial improvement. In contrast to patients with diminished cardiac reserve this effect is temporary. The different behaviour of the relation between stroke volume and segment volume in patients with diminished cardiac reserve and congestive heart failure under prolonged administration of digitalis points to the necessity of treatment with digitalis in the early stage of myocardial disease.
SummaryThe use of the first of a new class of chelating agents for the binding of metal ions to macromolecules as a novel approach to radiopharmaceutical labeling is described. Advantages are mild reaction conditions, large variety of accessible radionuclides and reactive groups, and separation of synthetic organic chemistry from radiochemistry. Human serum albumin and bovine fibrinogen labeled with mIndium using this technique were relatively stable in vitro and in vivo, showed little alteration in function, and have potential as tumor localizing agents in humans.
In a retrospective and prospective study the scintigraphically measured kinetics of intrathecally injected tracers are classified and compared with the final clinical diagnoses confirmed by additional examinations and clinical course. The results of the studies show characteristic dynamics of the tracer in patients without neurological diseases, whereas typically abnormal images are demonstrated in different neurological diseases.
Radio-iron utilization was nearly normal in these patients, only bilateral nephrectomized patients showed a reduced radio-iron utilization. Red blood half-life span was shortened in all patients, well corresponding to the degree of anemia. Parameters of erythropoesis like plasma iron clearance, bone marrow transit time, erythron iron turnover, non erythron iron turnover and hemolysis iron turnover failed to quantitate disorders of red blood cell regeneration in these patients. No defect in red blood cell enzyme activity could be demonstrated. Enzymes of glycolysis were increased corresponding to the reduced erythrocyte half-life span.
In a study with numerous samples of serum we compared 5 Digoxin RIA and evaluated the reliability of tests by simultaneous determinations. There were found considerable differences in the determinations with the various RIA for the same serum; evident differences also were recorded in the recovery and in the reproducibility of the assays. Among some other sources of error the dependence of temperature and of the duration of the dextran-charcoal separation were observed; therefore, the charcoal incubation is recommendable at 4 degrees C. Each laboratory which is able to perform the determinations of digoxin concentrations in the serum should declare its own range for the therapeutic and toxic levels for the used RIA in collaboration with the clinicians.
A simple and rapid method for the synthesis of 3-chloromercury-2-hydroxipropyl-urea has been described. It has been concluded that highest yields are obtained by the synthesis of 197HgO and allyl urea in the ratio of 2.5 : 1. Stability of the final preparation was investigated after thermal sterilization and standing at room temperature. It has been proved that the inorganic mercury-197 is not released. Radiochemical purity was controlled by chromatographic method using pyridine, n-butanol and water (3 : 10 : 3 v/v) as a solvent. The results obtained indicate that the preparation is applicable for human use.
In 175 patients the results of combined isotope studies i. e. inhalation and perfusion scintigraphy were compared with those of chest x-ray. The absorbed radiation dose due to the inhalation study calculated for whole body was 3 mrad/500 muCi, lungs 380 mrad/500 muCi, ovaries 0.3 mrad/500 muCi and testes 0.03 mrad/500 muCi. In 44 of our cases the isotope studies suggested the presence of a vascular occlusion, not detectable on the x-ray film in 36 cases. In the remaining 8 cases the inhalation study was found to add to the precision of the diagnosis. In nearly all other cases it was not found to have any diagnostic value.
Tc-99m pyridoxylidene glutamate has proven to be an excellent biliary scanning agent, far superior in many respect to the commonly used I-131 rose bengal. The preparation of the compound as previously reported by Baker et al is too time consuming and requires the use of an autoclave which is not available in most nuclear medicine departments. In our facility, we have been preparing similar compounds using several aldehydes and monosodium glutamate to make labeled complexes having the same pharmacological characteristics. The mixture of monosodium glutamate, aldehyde, and Tc-99m pertechnetate is made slightly alkaline, purged with helium, and placed in a sealed vial. The vial, which is protected by a wire basket, is then heated in a laboratory oven at 130 degrees C for a period of 15 to 20 minutes. During this time, the technetium is reduced to a lower valence state and bound to the complex formed. Chromatographic data show that these compounds are chemically similar to that previously reported. The compounds prepared concentrate in the gall bladder of the rabbit in less than 10 minutes. Kinetic studies have been performed on dogs with a scintillation camera and small digital computer to measure rates of blood clearance, liver and gall bladder uptake, and excretion into the intestine. The aldehyde -- glutamate complex promises to be a useful scanning agent for the diagnosis of biliary and hepatocellular diseases.
