Martin Wenger

Thallium-201 gated single-photon emission tomography for the assessment of left ventricular ejection fraction and regional wall motion abnormalities in comparison with two-dimensional echocardiography

Abstract. Simultaneous assessment of myocardial perfusion and function by gated single-photon emission tomography (GS) after a single tracer injection provides incremental information and is feasible with technetium-99m sestamibi. The present study validated the use of GS with thallium-201 for the assessment of left ventricular ejection fraction (LVEF) and regional wall motion by comparison with two-dimensional (2D) echocardiography (echo), which has not been done before. After injection of 111 MBq 201Tl at peak bicycle exercise (n=55) or pharmacological stress (n=17), GS was acquired 15 (post stress) and 120 min post injection (rest) on a double-head camera. An automatic algorithm (QGS) was used for processing. Echo (Acuson Sequoia C256) was performed immediately after rest GS. LVEFs assessed by GS and echo were correlated. The overall and segmental sensitivity and specificity of GS for the detection of regional wall motion abnormalities (WMAs) were calculated, echo serving as the gold standard. Perfusion abnormalities were scored. The success rate of the automatic algorithm was 100%, and visually assessed image quality was good to excellent in 88% of cases. Post-stress and rest LVEF as assessed by GS were highly correlated (r=0.91). Good correlations were obtained between post-stress LVEF (GS) and rest LVEF (echo) and between rest LVEF (GS) and rest LVEF (echo) (r=0.76 and 0.86 respectively). In patients with a reduced LVEF of less than 50% (n=23), these correlations were even better (r=0.84 and 0.89 respectively). Regional wall motion abnormalities (WMAs) were identified by GS with high sensitivity and specificity (88%–100% and 82%–98% respectively) and were directly related to the extent and severity of stress as well as of resting perfusion defects. It is concluded that GS with 201Tl is a feasible and reliable tool for the evaluation of patients with compromised left ventricular function in the context of coronary artery disease, and thus improves diagnosis and prognostic stratification. Regional WMAs were identified with high diagnostic accuracy and the method may prove helpful for the detection of myocardial viability.

18F-Fluorodeoxyglucose-positron emission tomography: A new explorative perspective

18F-Fluorodeoxyglucose-positron emission tomography (18F-FDG-PET) is a new functional imaging technique available for clinical and experimental use. 18F-FDG-PET studies can be used for screening, localization and follow-up of hypermetabolic processes including malignancies, infections and autoimmune processes. For several years it has been applied in oncological, cardiological and neurological patients, but nowadays an increasing number of studies favours its use in patients with autoimmune diseases including large vessel arteritis. From the experimental view, this technique has even become more important since the introduction of a small PET scanner for the use in animal models. This review focuses on technical aspects, clinical experiences and experimental and future perspectives of 18F-FDG-PET, with a special emphasis on large vessel vasculitis and other autoimmune diseases.

Surfactant protein B labelled with [99mTc(CO)3(H2O)3]+ retains biological activity in vitro

UNLABELLED Labelling of the hydrophobic surfactant protein B (SP-B) under non-reducing conditions was achieved with [(99m)Tc(CO)(3)(H2O)(3)](+) prepared according to Alberto et al. (JACS, 1998). The binding of radioactivity was protein-specific, with an overall radiochemical yield of 50%. Gel electrophoresis and Westernblot analyses showed no structural changes of SP-B. Spreading properties and surface activity of (99m)Tc-labelled SP-B in an air/water interface coincided with those of unlabelled SP-B. (99m)Tc-SP-B seems to be a promising agent to observe surfactant spreading under clinical conditions. BACKGROUND Therapeutic results for surfactant instillation in clinical trials are conflicting. The (99m)Tc-labelling of surfactant would allow to observe its spreading in the lung under clinical conditions. METHODS [(99m)Tc(CO)(3)(H2O)(3)](+) was prepared as described by Alberto et al. (JACS, 1998). This carbonyl complex was used for the direct labelling of surfactant protein B (SP-B) under non-reductive conditions by direct incubation with SP-B at elevated temperature followed by extraction into CHCl(3)/MeOH. RESULTS The hydrophobic protein SP-B was labelled with [(99m)Tc(CO)(3)(H2O)(3)](+). An overall radiochemical yield of about 50% was achieved. HPLC-analysis revealed a single radiolabelled species according to UV elution profile of SP-B, supported by paper and size exclusion chromatography. Gel electrophoresis confirmed that the dimer structure of SP-B was preserved. Spreading properties of (99m)Tc-labelled SP-B in an air/water interface coincided with those of unlabelled SP-B. Spreading of radioactivity observed in a glass trough of 26 cm x 27 cm with a gamma camera was completed during the first 7-9 sec after application of (99m)Tc-labelled SP-B. The corresponding decrease of surface tension to 45 mN/m at the peripheral surface tension sensors took 7 sec +/- 2 sec (MEAN +/- STD; n = 3). CONCLUSIONS Direct and specific (99m)Tc-labelling of the hydrophobic surfactant protein B was achieved using the [(99m)Tc(CO)(3)(H2O)(3)](+) precursor. This procedure can easily be used to prepare specifically labelled surfactant mixtures with spreading properties that coincide with those of unlabelled surfactant.

Generalized Large Vessel Arteritis Visualized by 18Fluorodeoxyglucose-Positron Emission Tomography

This previously healthy 81-year-old man with recurrent fever up to 38.8°C and an erythrocyte sedimentation rate of more than 85 mm/h had no pain and did not respond to empirical treatment with antibiotics. Imaging by computerized tomography, thyroid and whole body 99mTc-MIBI scintigraphy (because of pre-diagnosed hyperparathyroidism), gastroscopy, colonoscopy, and bone marrow aspiration were …

Fibromyalgia may mask onset of autoimmune diseases

A delay of diagnosing autoimmune diseases is a major problem in rheumatology. Patients complaining about sacroiliac pain, for example, are known to wait about seven years until diagnosis of ankylosing spondylitis is made (Braun et al., 1998). Some of these patients may experience stigmatization before receiving appropriate diagnosis and treatment (Asbring and Narvanen, 2002), and thus differentiation between early onset of an autoimmune disease and fibromyalgia may be difficult. In others, established diagnostic criteria for fibromyalgia (FM) (Wolfe et al., 1990) are fulfilled, but further evaluation denied by the patient. Here we retrospectively analyzed a series of consecutive FM patients previously admitted to our hospital for treatment of FM, but instead fulfilled criteria for different autoimmune diseases. Ten patients (51:8 4:3 years old, 9 female) with prior diagnosis of FM were re-evaluated in our rheumatic outpatient clinic with subsequent revision of FM diagnosis (Table 1). Average time until diagnosis of FM had been 1:6 3:5 years (0–8 years). All patients fulfilled the diagnostic criteria for FM. During followup, routine laboratory examinations were repeatedly normal except elevated erythrocyte sedimentation rates (up to 70 mm/h) which were interpreted as occult infections. Thus an additional 6:6 4:1 years (1–23 years) passed by until admission. After re-evaluation, accepted criteria for autoimmune diseases were fulfilled in 9 of these patients, including rheumatoid arthritis, spondylarthritis, sjoegren s syndrome, Hashimoto s thyroiditis and enthesopathies (Arnett et al., 1988; Vitali et al., 1993; Dougados et al., 1991). Diagnosis of FM was revised, and adequate treatment could be initiated. We conclude that even patients fulfilling the established FM criteria may show up with new symptoms and laboratory findings crucial for the diagnosis of an autoimmune disease. Therefore regular re-evaluation of FM patients appears to be warranted to avoid further delay of diagnosis and treatment in these patients.

[Lymph node tuberculosis in a patient with polymyalgic symptoms: value of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET)].

Zusammenfassung. Bei einer 60-jährigen Patientin mit corticosteroid-resistenter Polymyalgia rheumatica und einer erhöhten Blutsenkungsgeschwindigkeit wurde eine 18F-FDG-PET-Untersuchung durchgeführt. Diese zeigte einen cervicalen Focus, der histologisch und mikrobiologisch als Lymphknotentuberkulose identifiziert wurde.Summary.18F-FDG-PET studies were performed in a 60-year-old female patient with polymyalgia rheumatica resistant to prior corticosteroid treatment. PET studies showed a cervical focus, which was identified histologically and microbiologically as lymph node tuberculosis.

Lymphknotentuberkulose bei Polymyalgie-ähnlichem Syndrom: Wert der 18F-Fluorodeoxyglucose Positron Emissions Tomographie (18F-FDG-PET)

Zusammenfassung. Bei einer 60-jährigen Patientin mit corticosteroid-resistenter Polymyalgia rheumatica und einer erhöhten Blutsenkungsgeschwindigkeit wurde eine 18F-FDG-PET-Untersuchung durchgeführt. Diese zeigte einen cervicalen Focus, der histologisch und mikrobiologisch als Lymphknotentuberkulose identifiziert wurde.Summary.18F-FDG-PET studies were performed in a 60-year-old female patient with polymyalgia rheumatica resistant to prior corticosteroid treatment. PET studies showed a cervical focus, which was identified histologically and microbiologically as lymph node tuberculosis.

Lymphknotentuberkulose bei Polymyalgie-ähnlichem Syndrom: Wert der 18F-Fluorodeoxyglucose Positron Emissions Tomographie (18F-FDG-PET)@@@Lymph node tuberculosis in a patient with polymyalgic symptoms: value of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET)

Zusammenfassung. Bei einer 60-jährigen Patientin mit corticosteroid-resistenter Polymyalgia rheumatica und einer erhöhten Blutsenkungsgeschwindigkeit wurde eine 18F-FDG-PET-Untersuchung durchgeführt. Diese zeigte einen cervicalen Focus, der histologisch und mikrobiologisch als Lymphknotentuberkulose identifiziert wurde.Summary.18F-FDG-PET studies were performed in a 60-year-old female patient with polymyalgia rheumatica resistant to prior corticosteroid treatment. PET studies showed a cervical focus, which was identified histologically and microbiologically as lymph node tuberculosis.

3-D-Imaging and Volume Mathematics Versus Common Static Imaging in Combined Inhalation / Perfusion Lung Scintigraphy

The purpose of the present study was to assess the diagnostic value and the practical usefulness of inhalation-/ perfusion SPET of the lung applying Multimodality three- dimensional (3-D-) data analysis. Lung perfusion scintigraphy (LP) is a common method for detecting sites of decreased perfusion. Lung inhalation scintigraphy (LI) is routinely performed when perfusion defects are visualized by LP. Visual analysis of studies showing abnormalities both in LP as well as in LI, can sometimes be difficult to carry out. The comparison of the images can be difficult in cases with inhalation and perfusion defects. Combined LI/LP in planar and SPET 3-D-technique was investigated in 33 patients having known or suspected lung disorders. Our data demonstrate an equal sensitivity of the 3-D-SPET in patients with pure pulmonary embolism (PE) and a better sensitivity in patients with chronic obstructive pulmonary disease (COPD) and PE compared with planar scans. Both methods require similar acquisition time, the time needed for 3-D-processing generally depends on the performance of the computer equipment.