Background-Patients with Brugada syndrome present with characteristic ECG abnormalities (atypical right bundlebranch block and ST-segment elevation) and life-threatening ventricular tachyarrhythmias despite structurally normal hearts. Involvement of the autonomic nervous system is suggested by the occurrence of ventricular tachyarrhythmias and sudden death at rest or during sleep and by changes of typical ECG signs under pharmacological modulation of the myocardial autonomic tone. Methods and Results-This study investigated the presynaptic cardiac neuronal reuptake of norepinephrine (uptake 1) in 17 patients with Brugada syndrome and 10 age-matched control subjects with the use of the norepinephrine analogue
The aim of this study was to evaluate the clinical use of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in medullary thyroid cancer (MTC) on the basis of comparison with findings obtained using indium-111 pentetreotide (SMS), pentavalent technetium-99m dimercaptosuccinic acid (DMSA), technetium-99m sestamibi (MIBI), computed tomography (CT) and magnetic resonance imaging (MRI). One hundred FDG-PET examinations in 85 patients (40 males, 45 females) with elevated tumour marker levels and/or pathological findings on other imaging methods were evaluated retrospectively. Eighty-two patients were examined after total thyroidectomy, and the remaining three patients prior to surgery. Overall, 181 lesions could be identified with at least one of the imaging techniques. Fifty-five lesions were confirmed histologically. FDG-PET detected 123 of 181 sites, which is a lesion detection probability of 68%. In the 55 cases with histological confirmation, we found 32 true positive, 3 false positive, 11 true negative and 9 false negative lesions using FDG-PET, resulting in a sensitivity of 78% and a specificity of 79%. Sensitivity and specificity were, respectively, 25% and 92% for SMS, 33% and 78% for DMSA, 25% and 100% for MIBI, 50% and 20% for CT and 82% and 67% for MRI. Compared with morphological techniques and functional imaging methods with single-photon emitters, FDG-PET showed the highest lesion detection probability for MTC tissue, with a high sensitivity and specificity. It is concluded that FDG-PET is a useful method in the staging and follow-up of MTC.
Introduction: In patients with differentiated thyroid carcinoma, elevated serum levels of thyroglobulin (hTg) may occur in spite of otherwise negative diagnostic procedures and in particular in spite of a negative iodine-131 scan. Positron emission tomography with F-18-deoxyglucose (FDG-PET) is a potentially useful method for the detection of metastatic lesions or the recurrence of thyroid cancer. We aimed to investigate whether FDG-PET is capable of detecting metastastic lesions or recurrence in patients with differentiated thyroid carcinoma, elevated serum levels of thyroglobulin, and otherwise negative diagnostic procedures, including the iodine-131 scan. Methods: From a group of 500 patients with differentiated thyroid carcinoma, a subgroup of 32 patients had elevated serum hTg-levels, negative iodine-131 scans, negative cervical and abdominal ultrasound, and negative X-ray of the chest. In 12 of these patients (hTg 77.8±94.3 ng/ml, range 1.5 -277 ng/ml, median 20 ng/ml), FDG-PET was performed. All but one FDG-PET study was performed in a state of hypothyroidism (TSH 75.8±32.2 µIU/ml, range 31 -116 µIU/ml, median 74.6 µIU/ml). Results: In 6 of the 12 patients investigated, the FDG-PET was positive. In three of the patients, the diagnosis was confirmed by computed tomography or magnetic resonance imaging. In patients with a positive FDG-PET finding, the hTg level was 146.7±90.1 ng/ml (23 -277 ng/ml, median 144.5 ng/ml). In contrast, in patients with a negative finding the hTg level was only 9.0±7.6 ng/ml (range 1.5 -17 ng/ml, median 8.1 ng/ml), P = 0.01. Conclusion: These preliminary results show that in patients with differentiated thyroid carcinoma, elevated hTg levels, and otherwise negative "conventional" diagnostic procedures, FDG-PET is helpful in detecting metastatic lesions.A total of 500 patients treated for differentiated thyroid carcinoma were investigated retrospectively. Of these patients, 301 (60.2%) suffered from papillary carcinoma (48.0% pure papillary, 12.2% follicular variant), 199 (39.8%) from follicular carcinoma. The mean age of the 380 female (76.0%) and 120 male (24.0%) patients was 46.8±16.4 years at time of presentation.
Using single-photon emission tomography (SPET), the radiopharmaceutical l-3-iodine-123-alpha-methyl tyrosine (IMT) has been applied to the imaging of amino acid transport into brain tumours. It was the aim of this study to investigate whether IMT SPET is capable of differentiating between high-grade gliomas, low-grade gliomas and non-neoplastic brain lesions. To this end, IMT uptake was determined in 53 patients using the triple-headed SPET camera MULTISPECT 3. Twenty-eight of these subjects suffered from high-grade gliomas (WHO grade III or IV), 12 from low-grade gliomas (WHO grade II), and 13 from non-neoplastic brain lesions, including lesions after effective therapy of a glioma (five cases), infarctions (four cases), inflammatory lesions (three cases) and traumatic haematoma (one case). IMT uptake was significantly higher in high-grade gliomas than in low-grade gliomas and non-neoplastic lesions. IMT uptake by low-grade gliomas was not significantly different from that by non-neoplastic lesions. Diagnostic sensitivity and specificity were 71% and 83% for differentiating high-grade from low-grade gliomas, 82% and 100% for distinguishing high-grade gliomas from non-neoplastic lesions, and 50% and 100% for discriminating low-grade gliomas from non-neoplastic lesions. Analogously to positron emission tomography with radioactively labelled amino acids and fluorine-18 deoxyglucose, IMT SPET may aid in differentiating high-grade gliomas from histologically benign brain tumours and non-neoplastic brain lesions; it is of only limited value in differentiating between non-neoplastic lesions and histologically benign brain tumours.
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