Udalrich Büll

Metabolic Imaging of Untreated Prostate Cancer by Positron Emission Tomography with sup 18 Fluorine-Labeled Deoxyglucose

PURPOSE We evaluated positron emission tomograph (PET) with 18fluorine (18F)-labeled deoxyglucose for metabolic grading of untreated primary prostate cancer, and differentiation of benign and malignant prostatic disease. MATERIALS AND METHODS A total of 48 patients with untreated prostate cancer of different stages and 16 with histologically confirmed benign prostatic hyperplasia (BPH) underwent static PET after intravenous injection of 150 to 300 MBq. 18F-deoxyglucose. 18F-deoxyglucose accumulation was quantitated by calculating differential uptake ratios and prostate-to-skeletal muscle ratios. RESULTS Low 18F-deoxyglucose uptake was noted in the majority of primary tumors (81%). 18F-deoxyglucose accumulation did not correlate with increasing tumor grade or stage. There was a significant overlap in uptake values in BPH and malignant prostatic disease. A trend towards statistical significance was noted with lower prostate-to-skeletal muscle ratios in patients with BPH (p < 0.07). Increased 18F-deoxyglucose accumulation was detected in some patients with BPH and malignant prostatic disease, as well as in those with lymph node and bone metastases of prostate cancer. CONCLUSIONS 18F-deoxyglucose PET does not allow for metabolic labeling in the majority of untreated primary prostate cancers. BPH and primary prostate cancer cannot be reliably differentiated on the basis of PET. Increased 18F-deoxyglucose accumulation occurs in some primary prostate tumors and in metastatic deposits of prostate cancer.

Strain rate measurement by Doppler echocardiography allows improved assessment of myocardial viability in patients with depressed left ventricular function

OBJECTIVES This study sought to evaluate whether objective assessment of the myocardial functional reserve, using strain rate imaging (SRI), allows accurate detection of viable myocardium. BACKGROUND Strain rate imaging is a new echocardiographic modality that allows quantitative assessment of segmental myocardial contractility. METHODS In 37 patients (age 58 +/- 9 years) with ischemic left ventricular dysfunction, myocardial viability was assessed using low-dose (10 microg/kg body weight per min) two-dimensional dobutamine stress echocardiography (DSE), tissue Doppler imaging, SRI and (18)F-fluorodeoxyglucose ((18)FDG) positron emission tomography (PET). The peak systolic tissue Doppler velocity and peak systolic myocardial strain rate were determined at baseline and during low-dose dobutamine stress from the apical views. RESULTS A total of 192 segments with dyssynergy at rest were classified by (18)FDG PET as viable in 94 and nonviable in 98. An increase of peak systolic strain rate from rest to dobutamine stimulation by more than -0.23 1/s allowed accurate discrimination of viable from nonviable myocardium, as determined by (18)FDG PET with a sensitivity of 83% and a specificity of 84%. Receiver operating characteristic (ROC) curve analysis showed an area under the curve for prediction of nonviable myocardium, as determined by (18)FDG PET using SRI, of 0.89 (95% confidence interval [CI] 0.88 to 0.90), whereas the area under the ROC curve using tissue Doppler imaging was 0.63 (95% CI 0.61 to 0.65). CONCLUSIONS The increase in the peak systolic strain rate during low-dose dobutamine stimulation allows accurate discrimination between different myocardial viability states. Strain rate imaging is superior to two-dimensional DSE and tissue Doppler imaging for the assessment of myocardial viability.

Neurometabolic Effects of Psilocybin, 3,4-Methylenedioxyethylamphetamine (MDE) and d-Methamphetamine in Healthy Volunteers A Double-Blind, Placebo-Controlled PET Study with [18F]FDG

The neurometabolic effects of the hallucinogen psilocybin (PSI; 0.2 mg/kg), the entactogen 3,4-methylenedioxyethylamphetamine (MDE; 2 mg/kg) and the stimulant d-methamphetamine (METH; 0.2–0.4 mg/kg) and the drugs’ interactions with a prefrontal activation task were investigated in a double-blind, placebo-controlled human [F-18]fluorodeoxyglucoseFDG-positron emission tomographicPET study (each group: n = 8). Subjects underwent two scans (control: word repetition; activation: word association) within 2–4 weeks. Psilocybin increased rMRGlu in distinct right hemispheric frontotemporal cortical regions, particularly in the anterior cingulate and decreased rMRGlu in the thalamus. Both MDE and METH induced cortical hypometabolism and cerebellar hypermetabolism. In the MDE group, cortical hypometabolism was more pronounced in frontal regions, with the exception of the right anterior cingulate, which tended to be hyperactive. Cognitive activation-related increases in left frontocortical regions were attenuated under all three psychoactive substances, but less so under MDE. Taking into account performance data and subjective reports on task difficulty, these effects may result from different mechanisms across the three groups. Our PSI data are in line with studies on acute schizophrenic patients suggesting frontal overactivity at rest, but diminished capacity to activate prefrontal regions upon cognitive demand. The MDE data support the hypothesis that entactogens constitute a distinct psychoactive substance class, which takes an intermediate position between stimulants and hallucinogens.

Psychopathological and SPECT findings in never-treated schizophrenia

A total of 24 never‐treated (i.e. drug‐naive) actively psychotic schizophrenic patients, operationalized according to DSM‐III‐R, were examined in a pre‐post‐treatment design using the Positive and Negative Syndrome Scale for Schizophrenia (PANSS) and 99mTc‐HMPAO‐single photon emission computed tomography (SPECT) to assess regional cerebral blood flow (rCBF). The control subjects were 20 patients free of neurological and psychiatric symptoms. Before treatment there was only a slight hypofrontality, and hypoperfusion was observed in the left temporal superior region. After treatment, hypofrontality was reduced to one region and temporal hypoperfusion disappeared. Formal thought disorders were accompanied by increased rCBF in the bilateral frontal interior and left temporal superior regions. Delusions were associated with hypoperfusion in the anterior cingulate cortex. Negative symptoms showed no linkage to hypofrontality, either before or after treatment. Factor analysis showed delusions and hallucinations loading on different dimensions. The disorganized dimension correlated positively with all regions of interest, whereas these were negatively correlated with reality distortion.

Ergebnisse der Positronen- emissionstomographie mit Fluor-18-markierter Fluordesoxyglukose bei Differentialdiagnose und Staging des Pankreaskarzinoms

ZusammenfassungTrotz methodischer Verbesserungen in der Diagnostik des Pankreaskarzinoms ist die Differentialdiagnose pankreatischer Raumforderungen bei bestehender chronischer Pankreatitis sowie der Nachweis etwaiger Lymphknotenmetastasen bislang nur unvollständig gelöst. Die Bestimmung des regionalen Glukosestoffwechsels mit Hilfe der Positronenemissionstomographie (PET) und Fluor-18-markierter Fluordesoxyglukose (FDG) stellt einen neuen diagnostischen Ansatz dar, der nicht auf dem Nachweis morphologischer sondern metabolischer Tumorcharakteristika beruht. Bei 85 Patienten mit vermutetem Pankreaskarzinom wurde präoperativ eine FDG-PET durchgeführt und der Befund mit der histopathologischen Aufarbeitung des Operationspräparats verglichen. Von 55 malignen Tumoren konnten 47 anhand ihres Hypermetabolismus korrekt klassifiziert werden (85 %), 23 von 30 benignen Tumoren (77 %) wiesen keine Stoffwechselsteigerung auf (richtig-negativ). In der Ausbreitungsdiagnostik zeigte PET in 19 von 31 Fällen (61 %) korrekt das Vorliegen regionaler Lymphknotenmetastasen, in 7 von 13 Fällen (54 %) eine Lebermetastasierung an. Falsch negative Befunde fanden sch bei Diabetikern (5 von 8 unentdeckten Primärtumoren) während falsch positive Ergebnisse mehrheitlich (4 von 7) auf akut entzündliche Veränderungen bei chronischer Pankreatitis zurückzuführen waren. Diese Ergebnisse belegen, daß durch die FDG-PET eine Verbesserung der Diagnostik unklarer pankreatischer Raumforderungen erreicht werden kann, die zu einer Reduktion unnötiger Laparatomien beitragen könnte.SummaryAlthough the detection of pancreatic carcinoma has been considerably improved by recently developed imaging procedures, differential diagnosis between cancer and benign tumor masses, as well as lymph node staging, is still difficult. In vivo evaluation of regional glucose metabolism by means of positron emission tomography (PET) and fluorine-18-labelled fluorodeoxyglucose (FDG) is a new approach utilizing metabolic instead of morphological tumor properties for diagnosis.Patients and methods: A total of 85 patients with suspected pancreatic carcinoma were investigated by FDG-PET prior to surgery. Static PET scans were evaluated visually as well as quantitatively, taking increased FDG uptake as a sign of malignancy. PET results were correlated with intraoperative findings and histopathology of surgical specimens.Results: Forty-seven out of 55 (85 %) malignant tumors and 23 out of 30 (77 %) benign lesions were correctly classified by PET. Lymph node metastases were present in 31 patients, 19 of them (61 %) positive in PET. In 7 our of 13 (54 %) patients with liver metastases, PET detected hypermetabolic lesions. False-negative findings were mainly due to disturbance of glucose metabolism in diabetic patients, while most false-positive results could be attributed to acute inflammatory lesions in chronic pancreatitis.Conclusions: Our results indicate that classification of pancreatic masses can be improved by use of FDG-PET, which might lead to a reduction of unnecessary laparotomies in patients with benign or incurable disease.

Active and remitted schizophrenia: psychopathological and regional cerebral blood flow findings.

Single photon emission computed tomography with technetium-99m-d,l-hexamethylpropyleneamine oxime (99mTc-HMPAO) was used to assess regional cerebral blood flow (rCBF) during both florid and remitted stages of schizophrenia. Forty schizophrenic patients in an active phase of illness (diagnosis by DSM-III-R) were examined in two clinical states (ill vs. improved). At study entry, 24 patients were drug-naive, five were currently drug-free, and 11 were being treated with antipsychotic medication. Twenty medical patients who suffered from non-specific headaches but were free of neurological and psychiatric symptoms served as control subjects. At initial examination during the active phase of illness, cerebral perfusion patterns in the schizophrenic patients were characterized by both hypofrontality and hypotemporality. After remission, hypofrontality was no longer apparent in two of four frontal regions, and hypotemporality disappeared completely. As assessed with the Positive and Negative Syndrome Scale (PANSS), formal thought disorders, hallucinations, and ideas of grandiosity correlated with rCBF in the active phase of illness, but not after remission. In the remitted but not in the florid state, blunted affect, difficulties in abstract thinking, lack of spontaneity, and stereotyped thoughts correlated with rCBF. Correlations of five symptoms with rCBF changed significantly from first to second examination. The present study suggests that correlations between single psychotic symptoms and rCBF differ significantly in florid vs. remitted phases of schizophrenia.

Knochenmarkregeneration nach Bestrahlung der Wirbelsäule

Hintergrund: Die Darstellung des Knochenmarks mittels radioaktiv markierter monoklonaler Antikörper gegen das NCA-95-Antigen humaner Granulozyten eröffnet die Möglichkeit der direkten Abbildung der granulopoetischen Aktivität. Nach einer Strahlentherapie findet sich im Bestrahlungsfeld eine verminderte Speicherung. Ziel dieser Arbeit war die Untersuchung von Stärke und Zeitverlauf dieses Effekts. Patienten und Methode: Wir analysierten 80 Fälle von Patienten, die wegen unterschiedlicher Tumoren mit Feldern unter Einschluß der Wirbelsäule bestrahlt worden waren und im Rahmen der Nachsorge eine Knochenmarkszintigraphie erhalten hatten. Die Aktivität in bestrahlten und unbestrahlten Wirbelkörpern wurde mittels ROI gemessen. Der Quotient aus beiden gab die relative Knochenmarkdepression an. Ergebnisse: Eine Depression des Knochenmarks trat bereits nach wenigen Fraktionen von 1,8 bis 2 Gy ein. Mit zunehmendem Abstand zur Bestrahlung zeigte sich eine Regeneration des Knochenmarks. Bei Patienten ohne Knochenmetastasen kam es zu einer kompletten Knochenmarkregeneration, bei Patienten mit Knochenmetastasen fanden wir in allen Fällen nur eine inkomplette Regeneration. Schlußfolgerung: Für eine gewisse Zeit nach Bestrahlung bildet die Radioimmunszintigraphie die Strahlenfelder als Suppression der granulopoetischen Knochenmarkaktivität ab. Im weiteren Verlauf zeigt sie jedoch auch die Knochenmarkregeneration. So kann sie dazu beitragen, im Rahmen einer multimodalen Behandlung die Toxizität abzuschätzen.Background: Imaging of bone marrow by radio labeled antibodies against NCA-95 antigen of human granulocytes offers the possibility to visualize granulopoietic activity. After radiotherapy, a reduced uptake delineates the radiation field. Aim of our investigation was the study of strength and duration of this effect. Patients and Methods: We analyzed 80 cases of patients irradiated for different primary or metastatic malignancies including parts of the spine who received a bone marrow scan for re-staging or during follow-up. Activity uptake of vertebrae inside and outside the irradiation portal was evaluated by ROI and the ratio was taken as measure of bone marrow suppression. Results: A depression of granulopoietic bone marrow activity was seen even after a few fractions of 1.8 or 2 Gy (Figure 1). Depending on time since irradiation (Figure 2), we found a bone marrow recovery. In patients without bone metastasis, regeneration could be complete, whereas in patients treated for metastases, it was incomplete in all cases (Figure 3). Conclusions: For a certain time after irradiation, radioimmuno imaging delineates the irradiation portal by showing d epression of granulopoiesis. Later on, it also shows bone marrow regeneration after radiotherapy. This may be helpful in reconstruction of radiation portals or in toxicity estimation during multimodal cancer therapy.

MRT-basierte individuelle Regionenatlanten des menschlichen Gehirns Ziele, Methoden, Ausblick

Die direkte automatisierte Generierung dreidimensionaler Regionenatlanten des menschlichen Gehirns auf der Basis von individuellem kernspintomographischen Bilddatenmaterial (MRTBilddaten) berucksichtigt die interindividuelle Variabilitat menschlicher Gehirne. Die hierzu entwickelte Methodik besteht aus zwei aufeinander aufbauenden Schritten: der Gewebeklassifikation („Low Level“-Verarbeitung) und der wissensbasierten Analyse zur Extraktion anatomischer Regionen („High Level“-Verarbeitung). Die Quantifizierung koregistrierter emissionscomputertomographischer Bilddaten (ECT-Bilddaten) auf Basis der zugehorigen individuellen Atlanten ermoglicht die Berucksichtigung partialvolumenbedingter Effekte.

ROI-Atlas des menschlichen Gehirns durch neuronale Klassifikation und Konturverfolgung

Zur quantitativen Analyse funktioneller Bilddaten des Gehirns (PET, SPECT) soll die morphologische Modalitat (MRT) der genauen anatomischen Zuordnung funktioneller Parameter dienen. Die kernspintomographischen Schnittbilder werden hierzu durch einen neuronalen Klassifikator in funf Klassen segmentiert. Zur regionenorientierten Auswertung funktioneller Parameter werden die Regionengrenzen anschliesend als geschlossene Polygonzuge aus den Klassenbildern extrahiert. Diese Polygonzuge werden dann als klassifizierte Regionengrenzkonturen in Form eines ROI-Atlantenl der funktionellen Modalitat uberlagert.

Metabolische Darstellung ischämischer Bereiche durch die Positronenemissionstomographie

Die Positronenemissionstomographie (PET) erlaubt als einziges nichtinvasives Verfahren die absolute Quantifizierung von Blutflus und Stoffwechselvorgangen. Die wesentliche klinische Bedeutung der PET in der Kardiologie liegt in der akkuraten Differenzierung von prolongierter Myokardischamie gegenuber einer Myokardnarbe bei Patienten mit koronarer Herzerkrankung und gestorter regionaler Ventrikelfunktion. Die nichtinvasive Darstellung erhaltenen myokardialen Glucosestoffwechsels durch die PET erlaubt mit einer Treffsicherheit zwischen 78% und 85% (36,37) die Vorhersage des Erfolgs von Revaskularisationsmasnahmen in Bezug auf die Wiederkehr der regionalen Kontraktilitat. Wahrend eine konkordante Reduktion von Blutflus und Glucosestoffwechsel bei Narbengewebe zu finden ist, gilt der Nachweis erhaltenen Stoffwechsels in Regionen deutlich verminderter Ruheperfusion als Kriterium vitalen Myokards. Die PET kann durch Identifizierung derarter Bereiche einen wesentlichen Beitrag zur Therapieentscheidung liefern.