Search

Product development in medical technology is taking place likewise for hardware and software. A cost-effective way to improve the performance of existing medical products is the development of dedicated easy upgradable software. Installing additional complex reconstruction algorithm packages can improve the sensitivity and spatial resolution of PET scanners or SPECT systems dramatically. The rapid improving computer power today allows the implementation of computational very intensive algorithms. For three applications the advantage of pure software implementations in the daily routine is shown.

Zusammenfassung: Die Positronenemissionstomographie liefert regionale Information bezuglich dynamischer, physiologischer und biochemischer Prozesse im lebenden Korper. Der Positronenzerfall wird durch die aus der Annihilation resultierenden Gammaquanten nachgewiesen. Zwei gegenuberliegende Detektoren zahlen nur dann ein Ereignis, wenn beide nahezu gleichzeitig (koinzident) 511-keV-Gammaquanten registrieren. Der Positronenzerfall wird irgendwo auf der Verbindungslinie zwischen den Detektoren (die sog. Koinzidenzlinie) lokalisiert. Hierbei konnen infolge von Streuung oder zufalligen Koinzidenzen mogliche Fehlregistrierungen auftreten. Verschiedene Bauformen derzeitiger PET-Scanner werden vorgestellt und die Eigenschaften der bei der PET gebrauchlichen Szintillationskristalle erortert. Die Akquisition im 2D- und im 3D-Modus wird beschrieben. Korrekturmethoden fur die Schwachung, Streuung und Totzeitverluste werden behandelt. Fur die quantitative Analyse wird der relative Parameter Standard Uptake Value definiert. Abschliesend werden Hybridsysteme wie kombinierte PET/CT-Scanner und der Einsatz von CT-Daten fur die Schwachungskorrektur behandelt. Basic Principles of 18F-Fluorodeoxyglucose Positron Emission Tomography Summary: Positron emission tomography uses photons to receive regional information about dynamic, physiologic, and biochemical processes in the living body. A positron decay is measured indirectly by the simultaneous registration of both gamma rays created by the annihilation. The event is counted, if two directly opposite located detectors register gamma rays in coincidence. Unfortunately the detectors of a positron emission tomography system do not register only true coincident events. There are also scattered and random coincidences. Different types of positron tomographs are presented and scintillation crystals, which are in use for positron emission tomography are discussed. The 2D- and 3D-acquisition methods are described as well as preprocessing methods, such as correction for attenuation, scatter and dead time. For quantification the relative parameter standard uptake value (SUV) is explained. Finally hybrid systems, such as combined positron emission tomography/computed tomography scanners and the use of computed tomography data for attenuation correction are introduced.

We have studied transcription factors that are coupled to the activation of cytokine receptors in liver and in mammary epithelial cells. Interleukin-6 (IL-6) causes the rapid activation of the acute-phase response factor (APRF) in the liver of animals during acute inflammation and in cultured human hepatoma cells (HepG2) and induces the transcription of the acute-phase protein genes, e.g. alpha 2-macroglobulin (alpha 2-M). In the mammary gland and in cultured HC11 mammary epithelial cells, milk protein genes, e.g. beta-casein, are induced by the lactogenic hormones, insulin, glucocorticoids, and PRL. The induction of the beta-casein gene promoter is preceded by the activation of the mammary gland factor (MGF). We have compared the DNA binding sequences of APRF and MGF, 5'-CTTCTT/GGGAATT-3', and have found that they coincide in 11 of 12 positions. Bandshift experiments and oligonucleotide competition experiments showed that both factors, MGF and APRF, are able to bind to the IL-6 response element of the alpha 2-M gene promoter and to the lactogenic hormone response element of the beta-casein gene promoter with very similar specificities. Partial proteolytic digestion of APRF and MGF DNA complexes yielded similar clipping patterns. The UV cross-linked DNA complexes of both transcription factors were of the same apparent molecular mass. IL-6 activation of APRF in HepG2 cells can be observed within minutes. MGF induction by PRL in HC11 cells occurs with similar kinetics. The synergistic action of glucocorticoids and PRL is necessary for the induction of the beta-casein gene, but PRL is sufficient for MGF activation.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular systolic and diastolic performance was evaluated by radionuclide angiography in 17 patients following cardiac transplantation and compared with normal persons. Both groups performed supine bicycle exercise during the investigation, the control group at 102 ± 73 W and the transplanted patients at 61.2 ± 15 W. The ejection fraction increased in the normal persons from 61 ± 8 to 69 ± 10% whereas in the transplanted patients it did not increase significantly. There were no relevant changes in systolic parameters during exercise in the transplant recipients. The changes in diastolic parameters were significantly smaller in transplant patients than in normals. After correction for heart rate-induced changes a significantly different time course of the systolic-diastolic sequence during the cardiac cycle became evident in the transplanted group at rest. During exercise the systolic-diastolic sequence during the cardiac cycle became similar in both groups. It is concluded that the reduced exercise capacity of patients in the late phase after cardiac transplantation is partially due to the absence of an EF increase and a limitation of diastolic reserve during exercise.

The purpose of this study was to evaluate left ventricular function and perfusion at rest before and after percutaneous transluminal coronary angioplasty. In consecutive 69 patients in whom coronary stenoses were dilated, the radionuclide left ventricular ejection fraction at rest increased significantly. In 26 of these patients, the ejection fraction increased by at least 4%. In these patients, exercise-induced ischemic ST depression had been more pronounced than in the others. 36 other patients underwent 201TI myocardial scintigraphy before and after angioplasty. Twelve patients in whom pre-PTCA images had revealed regions with irreversible 201TI uptake defects, showed normal 201TI distribution patterns on post-PTCA scintigrams. Post-exercise 201TI uptake (representing myocardial perfusion and metabolic activity) during pre-PTCA exercise stress tests was significantly lower in these cases. It is concluded that PTCA can improve left ventricular function and perfusion at rest. This improvement is most obvious in patients with pronounced exercise-induced myocardial ischemia as diagnosed by typical ST segment depression and reduced thallium uptake.

Die Arbeitsgemeinschaft fur kardiovaskulare Nuklearmedizin der Deutschen Gesellschaft fur Nuklearmedizin hat eine Multizenterstudie durchgefuhrt, an der 13 Institute in der BRD teilnahmen. Mittels eines Fragebogens wurden die verwendeten Gerate und Methoden der Aquili-brium-Radionuklidventrikulographie sowie die mit ihr erzielten Ergebnisse an 585 Herzgesunden ermittelt. Die globale linksventrikulare Ejektions-fraktion betrug im Mittel 64%, doch zeigten sich signifikante Unterschiede zwischen den teilnehmenden Instituten, die wahrscheinlich auf Unterschiede in der Auswahl der Probanden und in den angewendeten Methoden zuruckgefuhrt werden konnen. Von der Mehrzahl der Institute wurde ein Anstieg der EF um mehr als 10% nach einer Ergometer-Belastung von mehr als 100 W angegeben. Enddiastolische, endsystolische und Schlagvolumina stimmten bei allen Instituten gut uberein. Wahrend Peak Ejection und Peak Filling Rates in Ruhe gut ubereinstimmten, differierten sie nach Belastung erheblich, vermutlich ebenfalls aus methodischen Grunden.

Positron emission tomography uses photons to receive regional information about dynamic, physiologic, and biochemical processes in the living body. A positron decay is measured indirectly by the simultaneous registration of both gamma rays created by the annihilation. The event is counted, if two directly opposite located detectors register gamma rays in coincidence. Unfortunately the detectors of a positron emission tomography system do not register only true coincident events. There are also scattered and random coincidences. Different types of positron tomographs are presented and scintillation crystals, which are in use for positron emission tomography are discussed. The 2D- and 3D-acquisition methods are described as well as preprocessing methods, such as correction for attenuation, scatter and dead time. For quantification the relative parameter standard uptake value (SUV) is explained. Finally hybrid systems, such as combined positron emission tomography/computed tomography scanners and the use of computed tomography data for attenuation correction are introduced.

International audience; Stat (signal transducers and activators of transcription) and Jak (Janus kinases) proteins are central components in the signal transduction events in hematopoietic and epithelial cells. They are rapidly activated by various cytokines, hormones, and growth factors. Upon ligand binding and cytokine receptor dimerization, Stat proteins are phosphorylated on tyrosine residues by Jak kinases. Activated Stat proteins form homo- or heterodimers, translocate to the nucleus, and induce transcription from responsive genes. Stat5 and Stat6 are transcription factors active in mammary epithelial cells and immune cells. Prolactin activates Stat5, and interleukin-4 (IL-4) activates Stat6. Both cytokines are able to stimulate cell proliferation, differentiation, and survival. We investigated the transactivation potential of Stat6 and found that it is not restricted to lymphocytes. IL-4-dependent activation of Stat6 was also observed in HC11 mammary epithelial cells. In these cells, Stat6 activation led to the induction of the beta-casein gene promoter. The induction of this promoter was confirmed in COS7 cells. The glucocorticoid receptor was able to further enhance IL-4-induced gene transcription through the action of Stat6. Deletion analysis of the carboxyl-terminal region of Stat6 and recombination of this region with a heterologous DNA binding domain allowed the delimitation and characterization of the transactivation domain of Stat6. The potencies of the transactivation domains of Stat5, Stat6, and viral protein VP16 were compared. Stat6 had a transactivation domain which was about 10-fold stronger than that of Stat5. In pre-B cells (Ba/F3), the transactivation domain of Stat6 was IL-4 regulated, independently from its DNA binding function.

The purpose of this study was to evaluate left ventricular function and perfusion at rest before and after percutaneous transluminal coronary angioplasty. In consecutive 69 patients in whom coronary stenoses were dilated, the radionuclide left ventricular ejection fraction at rest increased significantly. In 26 of these patients, the ejection fraction increased by at least 4%. In these patients, exercise-induced ischemic ST depression had been more pronounced than in the others. 36 other patients underwent 201TI myocardial scintigraphy before and after angioplasty. Twelve patients in whom pre-PTCA images had revealed regions with irreversible 201TI uptake defects, showed normal 201TI distribution patterns on post-PTCA scintigrams. Post-exercise 201TI uptake (representing myocardial perfusion and metabolic activity) during pre-PTCA exercise stress tests was significantly lower in these cases. It is concluded that PTCA can improve left ventricular function and perfusion at rest. This improvement is most obvious in patients with pronounced exercise-induced myocardial ischemia as diagnosed by typical ST segment depression and reduced thallium uptake.

Left ventricular systolic and diastolic performance was evaluated by radionuclide angiography in 17 patients following cardiac transplantation and compared with normal persons. Both groups performed supine bicycle exercise during the investigation, the control group at 102 +/- 73 W and the transplanted patients at 61.2 +/- 15 W. The ejection fraction increased in the normal persons from 61 +/- 8 to 69 +/- 10% whereas in the transplanted patients it did not increase significantly. There were no relevant changes in systolic parameters during exercise in the transplant recipients. The changes in diastolic parameters were significantly smaller in transplant patients than in normals. After correction for heart rate-induced changes a significantly different time course of the systolic-diastolic sequence during the cardiac cycle became evident in the transplanted group at rest. During exercise the systolic-diastolic sequence during the cardiac cycle became similar in both groups. It is concluded that the reduced exercise capacity of patients in the late phase after cardiac transplantation is partially due to the absence of an EF increase and a limitation of diastolic reserve during exercise.

Hepatobiliary scintigraphy (HBS) is a well established non invasive procedure for the differential diagnosis of intra-and extrahepatic jaundice. Clinical impact of hepatobiliary scintigraphy increased since the introduction of the 99mTc labeled hepatobiliary imaging agents by Loberg and coworkers in 1975 [16, 31].

The Working Group on Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine has organised a multi-center study in which 13 institutes in the FRG participated. Data on equipment and methods employed in equilibrium radionuclide ventriculography and on results in 585 non-cardiac patients were obtained by means of a questionnaire. The global left-ventricular ejection fraction amounted, on average, to 64% but there were significant differences between participating institutes, probably due to differences in the selection of subjects and in the methods used. The majority of institutes reported an increase in EF by more than 10% after an ergometric workload of more than 100 W. End diastolic, end systolic and stroke volume agreed well throughout. However, whereas peak ejection and peak filling rates at rest showed good agreement between institutes, those after exercise differed widely, probably also because of differences in methods.

In 19 patients with hypertrophic cardiomyopathy (15 males, 4 females, mean age 49.2 +/- 10.8 years) left ventricular function was studied with radionuclide ventriculography at rest and during exercise in a crossover design without intervention and after disopyramide and propranolol treatment. 15 of the 19 patients had a resting or latent intraventricular gradient of more than 30 mm Hg. Left ventricular function at rest and during exercise was evaluated before medication, 90 min after oral administration of 200 mg disopyramide or 160 mg propranolol and after 3 weeks of oral therapy with disopyramide 200 mg 2 times a day or propranolol 80 mg 4 times a day. After long-term treatment with disopyramide, resting ejection fraction decreased from 72 +/- 12 to 69 +/- 14% (p less than 0.01) and peak ejection rate (PER) decreased from 3.46 +/- 135 to 3.24 +/- 65 end-diastolic volume (EDV).s-1 (p less than 0.01). Peak filling rate (PFR) at rest decreased from 3.01 +/- 0.8 to 2.77 +/- 0.63 EDV.s-1 (p less than 0.05). Time to peak filling rate (TPFR) at rest and during exercise after acute and chronic therapy did not change compared to control values. Acute and long-term administration of propranolol lead to a significant reduction in heart rate at rest and during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Es wird ein semiautomatisches Computerprogramm zur Quantifizierung des globalen und regionalen 20-Minuten-99mTc-Speicherwertes beschrieben. Die Kalibrierung erfolgt über die in der leeren Spritze vorhandene Restaktivität. Störeinflüsse eines möglichen Paravasates werden bei der Uptake-Bestimmung berücksichtigt. Die standardisierte Definition der Schilddrüsen-Region-of-Interest durch eine Impulsdichtelinie im interpolativ untergrundkorrigierten Schilddrüsenszintigramm resultiert in einer nahezu völligen Unabhängigkeit von verschiedenen Auswertern. Wegen seiner äußerst kurzen Rechenzeit von 30 Sek. ist das Programm für die Routine geeignet.

ZusammenfassungBei 255 Patienten (Gruppe I: 30 -normale Schilddrüsen, Gruppe II: 134 euthyreote Strumen, Gruppe III: 63 hyperthyreote Strumen ohne Exophthalmus, Gruppe IV: 28 Patienten mit M. Basedow) wurde ein TSH-Rezeptor- Autoantikörper-Assay (TRAKAssay) zum Nachweis von Thyreotropin- Bindungs-inhibierenden Antikörpern (TBIAb) erprobt und vergleichend hierzu der 99mTc-Thyroid-Uptake (TcTU) bestimmt. In Gruppe I fanden sich nur normale TcTU (zwischen 1,5 und 5,5%) und normale TR AK-Werte (F < + ll% ) . In Gruppe II war im Sinne einer vermehrten Jodavidität der TcTU in 22,4% der Fälle erhöht, lediglich 2,2% der Patienten hatten TRAK-Werte > + 10%. Einen erhöhten TcTU wiesen 34,9% der Patienten in Gruppe III auf, es fanden sich hier keine erhöhten TRAK-Werte. Die vermehrte extrinsische Stimulation des TSH-Rezeptors bei Immun-Hyperthyreose (Gruppe IV) konnte durch den Nachweis von positiven TRAK-Werten in 71,4% erbracht werden. Korrelierend hierzu fand sich ein deutlich erhöhter TcTU (x̄ = 13,9%) bei M. Basedow in 82,1%. Da die Bestimmung des TcTU wesentliche differentialdiagnostische Hilfestellung geben kann, ist die Funktionsszintigraphie mit Gamma-kamera und Computer heute – insbesondere beim Verdacht auf Hyperthyreose – eine conditio sine qua non.

In 16 men with normal valvular function (group I) and 23 men and one woman with isolated aortic regurgitation (group 2) effective stroke volume was determined by first pass radionuclide ventriculography. Total left ventricular stroke volume was derived from equilibrium radionuclide ventriculography using a geometric approach for the end diastolic volume multiplied by the ejection fraction. The difference between the two stroke volumes as a fraction of total left ventricular stroke volume was taken as radionuclide regurgitant fraction. Radionuclide Iv/rv stroke count ratio was calculated as the ratio of end–diastolic–end–systolic count–rate differences from the left and right ventricles. All patients underwent left heart catheterization. A ngiographic regurgitant fraction was evaluated by the method of Sandier and Dodge in 16 patients of group 2. In the others, aortic regurgitation was quantified in 5 grades of severity. Group I was classified correctly by both radionuclide regurgitant fraction and Iv/rv stroke count ratio (specificity 100%). In group 2 the radionuclide regurgitant fraction was elevated in all (from +20% to +88%, sensitivity 100%), radio nuclide Iv/rv stroke count ratio in 19 of 24 cases (from 0/6 to 5/6, sensitivity 79%). The angiographic regurgitant fraction correlated well with the radionuclide regurgitant fraction (r=0–78), whereas a/o significant correlation was found between the angiographic stroke volume ratio (i.e. left ventricular stroke volume/ cardiac output per beat) and radionuclide stroke count ratio (r= 0/10) due to the high rate of false negative results of the latter method. In conclusion, in patients, with moderate to severe isolated aortic regurgitation, using combined first pass/equilibrium radionuclide regurgitant fraction allows a reliable noninvasive evaluation of aortic regurgitation which is superior to the evaluation of the radionuclide Iv/rv stroke count ratio.

Die vorliegende Studie vergleicht die Aussagekraft von Radionuklidventrikulographie (RNVG) und Myokardszintigraphie mit 201Tl (MSZ) jeweils mit Belastung und trisektoraler Computerauswertung. Hierzu wurden 137 Patienten vor und nach transluminaler Angioplastik (TCA) untersucht. Bei gleicher, 90% entsprechender Spezifitat (10% Perzentile des Kontrollkollektivs [n = 29]) betrug die Gesamtsensitivitat der RNVG 79% (n = 86) und der MSZ 78% (n = 98). Die Sensitivitat der RNVG fur Lasionen der Hinterwand lag niedriger als fur Lasionen der Vorderwand: RIA-Stenosen 83% (n = 46), RCA-Steno-sen 71% (n = 17), RCX-Stenosen 63% (n = 8). Bei der Sensitivitat der MSZ bestand nur ein geringer Unterschied zwischen Hinter- und Vorder-wandlasion: RIA-Stenosen 78% (n = 51), RCA-Stenosen 73% (n = 22), RCX-Stenosen 100% (n = 8). Sowohl bezuglich der Reproduzierbarkeit pathologischer Befunde vor und nach nicht erfolgreicher TCA als auch der Zuordnung myokardialer Lasionen zum betroffenen Gefas ist die MSZ geringgradig treffsicherer. Die potentielle Funktionsverbesserung nach erfolgreicher TCA kann mit Hilfe der MSZ vor dem Eingriff abgeschatzt werden, wahrend die RNVG den funktionellen Erfolg der Intervention dokumentiert.

Bei 9 Patienten mit angiographisch nachgewiesenem offenen Ductus arteriosus Botalli wurde eine Quantifizierung des Shuntvolumens mit der Farbstoff-Verdunnungsmethode und der Radionuklid-Ventrikulographie vorgenommen sowie der diagnostische Wert beider Verfahren verglichen. Nach transluminalem Verschlus des Ductus mit einem Ivalon®-Pfropf wurden die Untersuchungen wiederholt. Ein Patient konnte aufgrund einer Wiedereroffnung des Shunts zweimal untersucht werden. Die Farbstoffkurven wurden nach dem von Carter et al. angegebenen Verfahren ausgewertet. Bei der Radionuklid-Ventrikulographie wurde das effektive Vorwarts-Schlagvolumen aus der ersten Passage der radioaktiven Substanz durch das Herz berechnet; in der Aquilibriumphase wurden die links-ventrikulare Auswurffraktion (EF) und das enddiastolische Volumen (EDV) des linken Ventrikels bestimmt. Die Differenz zwischen dem totalen (Produkt aus EDV und EF) und effektivem Schlagvolumen (first pass), bezogen auf das gesamte Schlagvolumen des linken Ventrikels, ergab das prozentuale Shuntvolumen. Die Sensitivitat der Farbstoff-Verdunnungsmethode in der Shuntdiagnostik betrug 78%; eine Quantifizierung gelang jedoch nur in 55% der Falle (Shunt uber 35%). Die Sensitivitat des nuklearmedizinischen Verfahrens betrug 90%. Nur bei einem Patienten mit geringfugigem Shunt konnte die Schwere nicht bestimmt werden. Nach erfolgreichem Verschlus des Ductus normalisierte sich die Farbstoffkurve in allen Fallen. Nuklearmedizinisch wurde bei 9 von 10 Patienten eine Beseitigung des Shunts nachgewiesen ; lediglich bei einem Patienten mit begleitender Mitralinsuffizienz wurde weiterhin eine Volumenbelastung gemessen. Der Ductus-Verschlus fuhrte zu einer Abnahme des enddiastolischen Volumens des linken Ventrikels (von 224 auf 181 ml, p

In selected cases transluminal coronary angioplasty (TCA) may represent an effective alternative to bypass surgery in the treatment of coronary heart disease [2, 3, 4, 9, 15].

In order to study the course of chronic aortic regurgitation 17 patients with various degrees of aortic valve incompetence were investigated twice with a time interval of 1.5 +/- 0.4 years. The following parameters were evaluated: NYHA class; electrocardiographic sum of the largest R-wave in V4-V6 plus the largest S-wave in V1-V3 (RS index); echocardiographic left ventricular end-diastolic diameter (EDD); roentgenographic heart volume (HV); scintigraphic left ventricular end-diastolic volume (EDV), regurgitated blood volume (RBV) and ejection fraction (EF). During the period of observation functional deterioration occurred in 5 cases, all suffering from moderate to severe aortic regurgitation. While EF did not change significantly (55 +/- 12% vs. 55 +/- 11%), all other parameters showed a significant increase: RS index 5.4 +/- 1.4 mVolt to 6.0 +/- 1.7 mVolt (p less than 0.01); EDD 6.3 +/- 0.7 to 6.8 +/- 0.9 cm (p less than 0.001); HV 1017 +/- 151 ml to 1099 +/- 261 ml (p less than 0.01); EDV 371 +/- 131 ml to 441 +/- 175 ml (p less than 0.001); RBV 117 +/- 57 ml to 151 +/- 77 ml (p less than 0.001). Cases with functional deterioration showed a higher initial EDV and EDD (487 +/- 143 vs. 322 +/- 93 ml, p less than 0.05; 7.1 +/- 0.7 vs. 6.1 +/- 0.5 cm, p less than 0.01). The increase of HV, EDV and RBV during the time of observation was higher than in the remaining patients (166 +/- 137 vs. 39 +/- 95 ml, p less than 0.05; 133 +/- 75 vs. 44 +/- 29 ml, p less than 0.01; 66 +/- 22 vs. 22 +/- 31 ml, p less than 0.01). On average it was less pronounced in cases with mild initial left ventricular dilation than in those with marked dilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Voice and speech changes as a result of clinical treatment for 17 depressive and 15 schizophrenic patients were investigated. Speech samples taken at interviews before and after treatment were analyzed with regard to f0, spectral energy distribution, and formant frequencies of vowels occurring in identical phonetical context. Both groups of patients showed a decrease in f0 after therapy, which was interpreted as a reduction of general arousal. Differential results with regard to spectral energy distribution suggested that the voice of depressives became more relaxed after therapy, but the opposite seemed to be true for schizophrenics. Significant formant changes obtained for the first formants of two vowels were interpreted as differences in the precision of articulation before and after therapy.

Effective and total left ventricular (LV) stroke volume were assessed in 31 patients with verified aortic or mitral regurgitation, or both, and in 22 patients with normal valvular function using combined first-pass and equilibrium radionuclide ventriculography. The difference between these 2 volumes as a fraction of LV stroke volume was taken as the radionuclide regurgitant fraction. The results were compared with the LV/right ventricular (RV) stroke count ratio and with the angiographic regurgitant fraction according to the method of Sandler and Dodge. Radionuclide regurgitant fraction derived from 2 determinations with a time interval of 1 week showed good reproducibility (n = 15, r = 0.96, SEE = 9.1). Sensitivity was 100% for radionuclide regurgitant fraction and 87% for LV/RV stroke count ratio at equal specificity (100%). Radionuclide regurgitant fraction was more sensitive, especially in severely ill patients, in whom additional RV volume overload led to false-low or false-negative ratios. Angiographic and radionuclide regurgitant fraction showed linear correlation (r = 0.79, p less than 0.001). In contrast, because 5 patients had RV volume overload, only a weak correlation could be noticed between angiography and LV/RV stroke count ratio (r = 0.47, p less than 0.05). Excluding these patients, correlation substantially improved (r = 0.74, p less than 0.001). The combination of first-pass and equilibrium radionuclide ventriculography is a sensitive, specific and well reproducible method for the evaluation of mitral and aortic regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

In 15 patients with pure aortic valve incompetence and 5 patients with normal valvular function we determined cardiac output by first-pass-radionuclide ventriculography. In addition, left ventricular stroke volume was evaluated by equilibrium radionuclide ventriculography. The difference between those two volumes in relation to left ventricular stroke volume is the regurgitant fraction. Stroke volume index was calculated as the ratio of enddiastolic-endsystolic count differences of left and right ventricle. Patients with aortic insufficiency demonstrated a regurgitant fraction between 20 and 88%, whilst controls never exceeded 10% (on average-2%). Sensitivity therefore was 100%. In contrast, 2 of 15 patients with aortic valve incompetence showed a stroke volume index within normal range (sensitivity 87%). Regurgitant fraction correlated well with aortographically determined severity of valvular incompetence (r = 0.94). We conclude that combined first-pass-/equilibrium radionuclide ventriculography is a highly sensitive quantitative method for evaluation of aortic insufficiency.

Sehr viele Arzte verstehen unter Angina pectoris noch vorrangig und ausschlieslich einen schweren Anfall im Ruhezustand; sie verbinden damit ein allzu dramatisches Geschehen. Die meisten der Angina-pectoris-Patienten bekommen Schmerzen nur bei Mehrarbeit des Herzens, vorwiegend bei korperlicher Belastung. Die dabei auftretenden Schmerzen werden in der Regel nicht als allzu bedrohend empfunden, wohl auch aus dem Grunde, weil der Patient immer wieder erfahren hat, das er den Schmerz durch Beendigung der korperlichen Belastung in sehr kurzer Zeit zum Verschwinden bringen kann. Die typische Angina pectoris ist somit zunachst einmal eine Belastungs-Angina-pectoris. Dieser Gesichtspunkt wird ausfuhrlich in der klassischen Beschreibung des Krankheitsbildes durch William Heberden (1768) herausgearbeitet. Leider erleben wir heutzutage sehr haufig eine Ungenauigkeit der Anwendung des Begriffes „Angina pectoris“, wenn „herzbezogene“Schmerzen und Misempfindungen als „pektanginose“oder „stenokardische“Beschwerden mit in das Krankheitsbild einbezogen werden.

Zur Leistungsmessung des linken Ventrikels dient als nuklearmedizinisches Standardverfahren die EKG-getriggerte Radionuklidventrikulogra-phie. Hierbei wird die Aktivitatsanderung eines intravasal verbleibenden Radioindikators EKG-getriggert im Verlauf mehrerer hundert Herzaktionen registriert.

Procedures of nuclear cardiology are applied to the diagnosis and follow-up of hypertrophic cardiomyopathy in two aspects: (a) in the determination of myocardial thickening and (b) to document functional response to therapy. For morphological studies, T1-201 myocardial scintigraphy was introduced by Bulkeley in 1975 (7). Using a gated SPECT technique for myocardial scintigraphy, the wall thickening in different myocardial regions could be recorded (25). Soon after their introduction, gated blood pool studies were utilized to image regional dimension and motion of the myocardial wall (17). Later, instead of gated blood pool studies, one and two dimensional echocardiography were employed (8, 16). Besides morphological parameters, regional functional data at rest are available which enable one to quantify regional disorders and responses to drugs (6, 9, 21, 24). Nuclear cardiological measurements of global left ventricular functions, based on analysis of the left ventricular volume curve (time activity curve), were introduced by Bonow (3) in patients with hypertrophic cardiomyopathy before and during verapamil treatment.

In 255 patients (normals: group I, n = 30; nontoxic goitres: group II, n = 134; toxic goitres without ophthalmopathy: group III, n = 63; Graves' disease: group IV, n = 28) a TSH-receptor-autoantibody-assay (TRAK assay) for detection of thyrotropin-binding inhibiting antibodies (TBIAb) was tested and 99mTcO4-uptake (TcTU) was measured. Normal TcTU (range: 1.5-5.5%) and normal TRAK values (normal limit: F less than 11%) were only found in group I. An increased TcTU was found in group II in 22.4% (increased TRAK values only in 2.2%). In group III an increased TcTU was measured in 34.9% of the patients (all with normal TRAK titers). The stimulation of the TSH-receptor in immunogenic hyperthyroidism by TBIAb could be demonstrated by increased TRAK values in 71.4% of the patients with Graves' disease. In correlation, TcTU was also increased in 82.1% of the patients in group IV. As the measurement of TcTU can be helpful in differential diagnosis, the functional imaging with gamma camera and computer is today a conditio sine qua non, especially in suspected hyperthyroidism.

We studied 36 patients with successful transluminal coronary angioplasty (group 1) noninvasively using exercise electrocardiography, exercise T1-201 myocardial scintigraphy and equilibrium radionuclide ventriculography before and 3-5 days after the procedure. Six patients who underwent aortocoronary-bypass surgery (group 2) and 10 patients with stable angina pectoris (group 3) served as controls. All patients had arteriographically documented coronary artery disease at least in one major coronary vessel (stenosis greater than or equal to 70%). In group 1, average coronary stenosis was 81.1 +/- 8.4% before dilatation and 44 +/- 13.7% after the procedure (P less than 0.001). Ischemia score in the exercise electrocardiography decreased from 2.4 +/- 2.7 before dilatation to 0.4 +/- 0.8 after the procedure (P less than 0.001). Myocardial perfusion in computerized T1-201 myocardial scintigraphy 5-10 min after exercise expressed as vitality index (the ratio of T1-201 uptake in the ischemic region to the region of maximal uptake in the same image analyzed carefully in the same view in 2 studies) increased from 72.9 +/- 8.4% before dilatation to 79.9 +/- 11.7% after the procedure (P less than 0.001). Ejection fraction at rest increased from 47.2 +/- 9.2% to 51.0 +/- 9.7% (P less than 0.001) and during exercise from 39.9 +/- 10.5% to 49.4 +/- 10.9% (P less than 0.001) before and after the procedure. In group 2, noninvasive studies showed a tendency to improvement after surgery. In group 3 no significant changes were noted. We conclude that transluminal coronary angioplasty improves both coronary perfusion to ischemic areas supplied by critical coronary artery stenoses and left ventricular function, especially during exercise, if luminal diameter is dilated by greater than 20%.

To assess the results of transluminal coronary angioplasty (TCA), 42 patients (mean age 50 years) with for coronary artery disease were investigated at rest and during exercise with the ECG (n = 40), thallium-201 myocardial scintigraphy (n = 23) and equilibrium-radionuclide ventriculography (n = 32). Each method of stress testing was quantified: the exercise ECG by means of an ischemia score, incremented with increasing ST-segment depression and decremented as a function of duration of exercise and workload in watts; thallium-201 scintigraphy by means of an index for minimal to maximal perfusion region (vitality index) and redistribution factors; equilibrium-radionuclide ventriculography by means of global ejection fraction and maximum systolic volume change with respect to the end-diastolic volume. The patients were divided into three groups: 30 had successful TCA defined as demonstrating at least a 20% reduction in the stenosis; six underwent aortocoronary bypass operation (nine grafts; complete revascularization in four patients); and in six patients TCA was unsuccessful. TCA was successful in 24 LAD stenoses, 5 RCA stenoses, and in one proximal anastomosis of an aortocoronary bypass graft. Dilatation could not be achieved in three LAD stenoses and three stenoses of the RCA. In those in whom it was successful, TCA yielded an average reduction of coronary artery stenosis from 84 to 43%. Both TCA and bypass operation (OP) led to comparable degrees of functional improvement. The ischemia score decreased from 2.8 to 0.9 after TCA and from 1.6 to 0 after OP. The vitality index increased from 67 to 77% and from 74 to 81% after TCA and OP respectively while the corresponding redistribution factors decreased (TCA: at 1 hour from 5 to 1% and at 3.5 hours from 11 to 4%; OP: at 1 hour from 2.2 to 1.4% and at 3.5 hours from 7.6 to 4.1%. The global ejection fractions at rest improved from 46 to 52% and from 38 to 45% and during exercise from 42 to 50% and from 36 to 43% after TCA and OP respectively. The maximum--dV/dt/EDV increased at rest (TCA: from 2.7 to 3.5 per second; OP: from 2.1 to 3.8 per second) and during exercise (TCA: from 3.1 to 4.0 per second; OP: from 2.6 to 3.3 per second). In the group with unsuccessful TCA, no significant differences in the latter parameters were observed. Ten of the 30 patients who had undergone successful dilatation were reinvestigated after three months. Maintenance of good functional results could be documented in eight while deterioration was seen in two patients, one with a significant restenosis and one who developed a new narrowing distal to the successfully dilated stenosis. Thus, the results show that in selected cases, TCA can render improved ventricular function and perfusion comparable to that of aortocoronary artery bypass surgery.

A fully automated computer program is described for processing equilibrium radionuclide ventriculography data with regard to global and sectorial left ventricular ejection fraction. The precise identification of the left ventricular outline, a prerequisite for reproducible determination of sectorial ejection fraction, was achieved by using morphological and functional criteria in a sequential edge detection technique. The high reproducibility of this method (correlation coefficient r: global ejection fraction r = 0.96, sectorial ejection fraction r = 0.82-0.97) allows the evaluation of a mean normal sectorial ejection fraction profile and its adaptation to the individual left ventricle. Computerized comparison between individual and adjusted normal sectorial ejection fraction permits quantitation of the degree and localization of functional impairment at rest, sectorial comparison between ejection fraction at rest and during peak exercise is used for the detection of ischemic functional impairment. The success rate of end diastolic left ventricular edge detection of 96% and the processing time of 150 s makes this method suitable for routine use.

After aortic valve replacement for chronic aortic regurgitation, complete normalization of the left ventricular end-diastolic volume can rarely be observed. We therefore investigated the role of continual volume overload caused by persisting concomitant mitral regurgitation. 20 patients who received an aortic valve for chronic aortic regurgitation (group 1), 5 patients after operation for aortic stenosis (group 2) and 6 patients with double valve replacement because of aortic and mitral valve lesions were included in the study 1 to 108 months after operation. All patients were examined clinically and by combined first pass/equilibrium radionuclide ventriculography. In the case of significant regurgitation (greater than 20%) 2-dimensional colour-coded Doppler-echocardiography was performed in patients of group 1 to localize the regurgitant lesion. 15 patients of group 1 had a typical systolic murmur indicating mitral regurgitation. 14 of these patients had significant scintigraphic left-sided heart regurgitation: 7 patients had regurgitant fractions between 21 and 40%; 6 patients between 41 and 60%; in 1 patient RF was 64%. Echocardiography confirmed mitral regurgitation in 9 of 11 of these cases. No significant regurgitation was observed in patients of group 2; mild regurgitation was measured in 5 of 6 patients of group 3 (26 to 31%). We conclude that in patients with chronic aortic regurgitation complete normalization of the left ventricular end-diastolic volume after valve replacement may not occur in some patients because of persisting mitral regurgitation.

This study compares exercise radionuclide ventriculography (RNVG) and exercise myocardial scintigraphy with 201Tl (MSC) both computed trisectorially. 137 patients before and after transluminal angioplasty (TCA) were investigated. While specificity equivalent was set at 90% for both methods (10% percentile of the controls [n = 29]) overall sensitivity for RNVG was 79% (n = 86) and for MSC 78% (n = 98). Sensitivity of RNVG for lesions of the posterior wall was lower than for the anterior wall: LAD stenoses 83% (n = 46), RCA stenoses 71% (n = 17), and LCX stenoses 63% (n = 8). Sensitivity of MSC presents only a slight difference between anterior and posterior wall lesions: LAD stenoses 78% (n = 51), RCA stenoses 73% (n = 22), RCX stenoses 100% (n = 8). Reproducibility of pathological findings before and after non-successful TCA and the determination of the stenosed vessel was slightly better with MSC than with RNVG. Functional improvement after a successful TCA is predictable by MSC, whereas RNVG documents the functional improvement.

The range of appropriate left ventricular dilatation due to volume overload was defined in 21 patients with a stable course of chronic aortic regurgitation, by correlating the scintigraphically determined left ventricular end-diastolic volume with the regurgitated blood volume. 25 other patients with chronic aortic regurgitation, who were scheduled for valve replacement, were within this normal range (group 1); in nine patients, left ventricular end-diastolic volume exceeded the amount expected from the amount of regurgitation (group 2). Patients were followed up between 2 and 62 months postoperatively (average: 26 +/- 13 months). No patients from group 1, but four out of nine patients from group 2 (45%) died postoperatively from congestive heart failure. In 23 out of 24 patients from group 1, left ventricular ejection fraction was postoperatively within the normal range, although preoperative values had been severely depressed in three cases (lower than 40%). Ejection fraction remained depressed in one patient with persistent mitral regurgitation and in all patients from group 2. Global heart volume significantly decreased by 20% in group 1, whereas only minor changes (-15%) were observed in group 2 (group 1: from 1184 +/- 186 to 954 +/- 120 ml, 2p less than 0.001; group 2: from 1402 +/- 300 to 1185 +/- 294 ml). This was compared to the course of left ventricular end-diastolic diameter (group 1: from 7.1 +/- 0.9 to 5.5 +/- 0.7 cm (-23%), 2p less than 0.001; group 2: from 7.6 +/- 0.7 to 6.9 +/- 1.3 cm (-9%). In group 1, left ventricular ejection fraction significantly increased, whereas no significant changes were observed in group 2 (group 1: from 53 +/- 13 to 64 +/- 13% (+21%), 2p less than 0.001; group 2: from 29 +/- 7 to 32 +/- 14% (+10%]. It is concluded that the scintigraphically determined ratio of left ventricular end-diastolic volume to regurgitated blood volume provides important prognostic and functional information regarding the postoperative course of chronic aortic regurgitation. This ratio is more reliable than single radionuclide, electrocardiographic, roentgenographic or echocardiographic parameters.

A semiautomatic computer program is described for the quantification of global and regional 20 min 99mTc-thyroid uptake. The procedure is self-calibrating by the activity remaining in the empty syringe. The standardized definition of the thyroid ROI by an isocontour in the interpolative background corrected thyroid image results in an excellent inter-observer variability. The very short processing time of 30 sec makes this procedure suitable for routine use.

In 16 patients with chronic aortic regurgitation, we studied the acute hormonal and hemodynamic effects of 12.5 to 25 mg captopril; in 12 patients the changes after a 4 to 8 week treatment period (mean 6.3 +/- 2 weeks; doses: 3 times 12.5 to 3 times 25 mg/day) were investigated. The following baseline variables were evaluated: the radionuclide left ventricular ejection fraction (EF) at rest and during exercise, left ventricular end-diastolic volume (EDV), regurgitant blood volume (RBV); and plasma renin activity (PRA). Repeated determinations of EF, EDV and RPA were carried out 90 minutes after application of the drug. In patients with chronic therapy, EF at rest and during exercise, EDV, RBV and PRA were reinvestigated at the end of the study. Acute administration of captopril was followed by an increase of EF (from 49 +/- 12 to 55 +/- 12%, p less than 0.001) and a slight decrease of EDV (from 389 +/- 160 to 376 +/- 146 ml, p less than 0.05). PRA significantly increased (from 1.6 to 3.1 ng/ml/h, p less than 0.05). Chronic therapy resulted in a moderate decrease of systolic and diastolic blood pressure (from 156/70 +/- 31/15 to 140/63 +/- 23/15 mm Hg, p less than 0.01). However, no significant changes were observed in EF at rest and during exercise (51 +/- 9 vs. 53 +/- 10% and 45 +/- 14 vs. 47 +/- 14%), EDV (433 +/- 179 vs. 422 +/- 179 ml) and RBV (136 +/- 81 vs. 129 +/- 77 ml). PRA was significantly increased (6.3 ng/ml/h, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Recently, monoclonal antibody techniques have provided an opportunity to reevaluate the role of nuclear medicine for the diagnosis of malignant diseases by using the immunological approach. The pioneering studies of Kohler and Milstein [1] made it possible to prepare in vitro immortal cell lines by means of the chemically mediated fusion of lymphocytes from immunized mice and cells from a mouse myeloma tumor. Cloned hybrid cells produce individual monoclonal antibodies in a continuous and virtually endless supply with extremely precise specificity and uniform reaction. To obtain greater specificity in the interpretation of neoplastic masses by in vivo methods, the immunological approach appears to be most promising. About 90 years ago the first attempt to use antibodies produced against malignant tissues was reported by Hericourt and Richet [2]. They prepared antiserum against human osteogenic sarcoma and observed that these sera were effective in the treatment of a fibrosarcoma and a gastric cancer.

21 patients with LAD-stenoses of at least 70% and 21 patients with LAD-stenoses and additional intramural anterior wall infarctions were studied. 20 patients without heart disease or after successful transluminal coronary angioplasty and 18 patients with intramural anterior wall infarction after successful transluminal dilatation of the LAD (remaining stenosis maximal 30%) served as controls. The normal range of global and regional left ventricular ejection fraction response to exercise was defined based on the data of 25 further patients without relevant coronary heart disease. Thus, a decrease in global ejection fraction and regional wall motion abnormalities were judged pathological. All patients were comparable with respect to age, ejection fraction at rest and work load. Myocardial ischemia could be detected by the exercise ECG in 81% of all patients without infarction and in 71% of patients with infarction. The corresponding values for global left ventricular ejection fraction were 76% and 81%, respectively, and for regional ejection fraction 95% in both groups. No false-positive exercise ECGs were observed in the healthy controls and 2 (11%) in the corresponding group with intramural infarction. The global ejection fraction was pathological in 1 (5%) healthy subject without infarction and in 3 (17%) corresponding patients with infarction. Sectorial analysis revealed 5 and 22%, respectively. Our findings suggest that the exercise ECG has a limited sensitivity to detect myocardial ischemia in patients with isolated LAD-stenoses and intramural myocardial infarction. Radionuclide ventriculography yields pathological values more often; however, false-positive results also occur more frequently.

We describe a fully automated method for quantification of left ventricular performance by equilibrium radionuclide ventriculographic studies, based on subdivision of the left ventricular region into 9 equiangular sectors. The precise identification of the left ventricular contours is achieved by the use of morphological and functional criteria in a sequential edge detection algorithm with a success rate of 96%. In addition to left ventricular global and sectorial ejection fraction the first harmonic of the corresponding Fourier spectrum is approximated to each sectorial time-activity curve and to the global one. Sectorial phase is calculated as the difference between the phase of the sectorial and global first Fourier component. Computerized comparison between the sectorial parameters at rest and during peak exercise localizes and classifies the degree of global and regional impairment in response to exercise. The processing time of 60 sec makes this method suitable for routine use. The validity of our procedure has been tested in 34 patients before and after successful transluminal coronary angioplasty. In these patients, 73% of the stenosed vessels before dilatation were localized by sectorial ejection fraction, 77% by sectorial phases, and 88% by the combination of both.

In 9 patients with patent ductus arteriosus, quantification of left-to-right shunt was performed with dye dilution curves after peripheral injection and with radionuclide ventriculography. The study was repeated within 7 days after successful transluminal occlusion of the ductus with an Ivalon-plug. Reproducubility of the method could be studied in one patient in whom reopening of the ductus occurred. Dye dilution curves were analyzed using the method of Carter et al. Radionuclide ventriculography was performed as a combined first-pass and equilibrium study: effective stroke volume was derived from the first pass of the tracer through the heart; during the equilibrium phase left ventricular ejection fraction (EF) and left ventricular enddiastolic volume (EDV) were evaluated. The difference between total left ventricular stroke volume (product of EF and EDV) and effective stroke volume was taken as shunt volume. This volume as a fraction of total left ventricular stroke volume resulted in percent left-to-right shunt. The sensitivity of the dye technique was 78%; a quantification of the shunt lesion was possible in 55% of all cases (shunt greater than 35%). The sensitivity of the radionuclide technique was 90%. The severity of the lesion could not be determined in one patient with a minimal shunt. After successful occlusion of the ductus, dye dilution curves normalized in all cases. Radionuclide ventriculography showed normalization in all but one patient. This patient with concomitant mitral regurgitation still showed moderate left ventricular volume overload.(ABSTRACT TRUNCATED AT 250 WORDS)