99-mTc-HMPAO single photon emission computed tomography examinations in genetically determined neurometabolic disorders.

UNLABELLED: The aim of our study was to determine regional cerebral blood flow (rCBF) abnormalities in different types of enzymopathies. PATIENTS AND METHODS: Among the patients with genetically determined enzymopathies 3 patients had aminoacidopathies, and 11 had different types of encephalopathies, from which 10 had mitochondrial encephalomyopathy (MEMP), and 1 patient had hyperuricaemic encephalopathy. Besides the mentioned 14 patients, 1 had ceroid lipofuscinosis and another patient had tuberous sclerosis. The further distribution of the MEMP patients' group was the following--5 patients had MEMP with lactic acidosis, 5 had Leigh's disease (subacute necrotizing encephalopathy), from which 1 had cytochrome-c-oxidase deficiency (COX). Additionally in all patients were performed cerebral MRI and SPECT examination 10 min. after intravenous administration of 20 Mbq/kg 99 mTc-HMPAO. RESULTS: Fourteen out of 16 SPECT findings were pathologic, showing decreased focal frontal/temporal/temporoparietal cerebral blood perfusion. Aminoacidopathic group--all the 3 patients revealed pathologic signs from the aminoacidopathic patients' group. Among them the ornithine transcarbamylase (OTC) heterozygous female patient with left-sided hemiparesis caused by hyperammonemic stroke at 10 month-age, showed right sided temporoparietal, occipital and left frontal hypoperfusion, nearly 6 years after the cerebral vascular attack. This finding might be resulted because of diaschisis. Mitochondrial encephalo-myopathic (MEMP) group--all the four patients with MEMP and lactic acidosis showed focal hypoperfusion in the temporal region, while the perfusion was normal in the COX deficient patient and in 2 Leigh's disease (subacute necrotizing encephalopathy) patients. In the remaining 1 Leigh's patient frontotemporal hypoperfusion was found. In all patients there were non specific structural abnormalities detected by MRI: cortical and subcortical atrophy, and scattered demyelination foci. In the case of ceroid lipofuscinosis the MRI showed cerebral atrophy and cerebellar hypoplasia, and the SPECT showed right frontal and occipital hypoperfusion, bilateral parietal physiological riping process. The patient with tuberous sclerosis showed bilateral temporo-occipital hypoperfusion. CONCLUSION: (1) SPECT images demonstrated hypoperfusion rCBF changes in 14 out of all 16 patients. (2) Regional cerebral/cerebellar hypoperfusion was detected by SPECT in mitochondrial encephalomyopathies, with lactate acidosis and aminoacidopathies giving high informative value about the cerebral perfusion.

The prognostic value of dopamine receptor occupancy by [123I]IBZM-SPECT in schizophrenic patients treated with quetiapine.

BACKGROUND: In the present study D2 receptor occupancy was investigated in quetiapine treated schizophrenic patients for the detection of a relationship between the scintigraphic pattern and clinical signs and symptoms. MATERIAL AND METHODS: In 10 schizophrenic patients [123I]IBZM-SPECTs were performed during the introduction of quetiapine therapy (600-800 mg/day) and during a lower maintenance dose (200-400 mg/day). The patients' clinical follow-up was continued for 1 year. For the evaluation of SPECT images, visual interpretation was performed and striatum/occipital lobe (S/O) activity ratio was calculated. RESULTS: The initial striatum/occipital ratio was significantly higher in patients with relapse compared to the others (1.86 +/- 0.17, 1.53 +/- 0.15, p < 0.01). The decreasing striatum/occipital ratio (increasing D2 receptor occupancy) on the 2nd SPECT was a predictive factor for the relapse. CONCLUSIONS: D2 receptor occupancy and its changes during quetiapine therapy were related to the prognosis of the treatment efficacy.

[The role of FDG-PET scan in the diagnosis of pancreatic carcinoma]. / Az FDG-PET-vizsgálat értéke a pancreascarcinoma diagnosztikájában.

In 22 patients with focal pancreatic lesions, the values of different diagnostic modalities were analysed for the evaluation of malignancy. The CA 19-9 level was elevated in 4/5 malignant cases (sensitivity: 80%) and in 4/15 of benign cases (specificity: 73%). Hypodensity/hypoechogeneity was considered to be the characteristic sign of malignancy during CT/ultrasound (sensitivity: 100%, specificity: 50%/47%). ERCP was found to be specific but not sensitive enough and the rate of unsuccessful investigations was relatively high (4/22). The diagnostic value of FDG-PET was found to be superior to other diagnostic modalities (sensitivity 100%, specificity 88%). In cases with focal pancreatic hypoechogenic/hypodense lesions detected by CT or US in suspicion of malignancy, the FDG-PET should be the next step in the diagnostic strategy.

The possible role of F-18 FDG positron emission tomography in the differential diagnosis of focal pancreatic lesions.

PURPOSE: To compare the diagnostic values of different methods for the differentiation of malignant from benign pancreatic lesions. METHODS: In 22 patients with focal pancreatic lesions, the carbohydrate antigen (CA) 19-9 level was measured; abdominal ultrasound (US), computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), and F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) were performed; and the value of these methods were analyzed for their use in cancer diagnosis. RESULTS: Malignant lesions were identified in six patients and verified by surgery or clinical follow-up. The CA 19-9 level was elevated in four of the five patients examined (sensitivity, 80%). In all six cases, US and CT revealed hypoechogenic and hypodense areas (sensitivity, 100%). In one patient, ERCP was unsuccessful but yielded true-positive results in three others (sensitivity, 60%). The sensitivity of FDG PET was 100%. Sixteen focal cases of pancreatic disease proved to be benign. The CA 19-9 level was elevated in four of them (specificity, 73%). Hypoechogenic and hypodense areas were evident on US and CT in eight patients. The specificity of CT was 50% (8 of 16 cases). The specificity of US was 47% (7 of 15 cases). The specificity of successful ERCP was 92%. Fourteen negative FDG-PET results were truly negative. In two patients, however, the PET findings proved to be falsely positive (specificity, 88%). CONCLUSIONS: FDG-PET is an effective tool to differentiate malignant from benign focal pancreatic lesions. In persons with focal pancreatic hypoechogenic or hypodense lesions detected by CT or US and an elevated CA 19-9 level, FDG PET should be the next step in the diagnostic strategy.