SPECT and PET imaging of brain tumors.

The unique capacity of measuring or visualizing intracellular biochemical processes allows nuclear medicine techniques to determine functional and metabolic activities of various disorders. This article describes the critical role of single-photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging of brain tumors beyond what can be achieved by anatomic methods.     

PET and SPECT functional imaging in Parkinson's disease

Neuroimaging studies of the dopaminergic system with positron emission tomography and single photon emission computed tomography radioligands are useful in the assessment of neuronal degeneration in Parkinson's disease. Abnormalities can be identified early in the disease process and used to monitor progression as well as the effect of treatment. Studies of dopamine receptors and brain metabolism can help identify those patients who have other Parkinsonian syndromes, such as multiple system atrophy, progressive sopranuclear palsy or diffuse Lewy body dementia. The current available diagnostic criteria for these disorders rely solely on the presence of signs and symptoms that may require months or years to become fully clinically manifest. Conversely, the use of neuroimaging techniques can significantly shorten the diagnostic process and prove a useful means to the neurologist in those cases presenting with uncertain clinical diagnosis.     

Structural and functional magnetic resonance imaging in psychiatric disorders.

OBJECTIVE: To report on recent advances in both structural and functional brain imaging studies in psychiatry and to highlight their importance for the field. METHOD: We reviewed recently published articles dealing with such advances and abstracted them into a selective review of the field. RESULTS: Some of the more important trends include integration of genetic information into research studies, use of novel quantitative image measurement techniques, studies of new subject populations, the use of pharmacologic probes in functional magnetic resonance imaging (fMRI) studies, the incorporation of elements of virtual reality into fMRI task stimuli, and the methodological innovation of hyperscanning. CONCLUSIONS: A whole series of new approaches and techniques are resulting in rapid advances in neuroimaging in psychiatry. Several of these show the potential for clinical translation.     

SPECT and PET imaging of the dopaminergic system in Parkinson's disease

Journal of Neurology - This paper gives an overview of the clinical importance of SPECT and PET imaging of the dopaminergic system in the differential diagnosis and for the determination of the...     

SPECT and PET imaging of the dopaminergic system in Parkinson's disease

This paper gives an overview of the clinical importance of SPECT and PET imaging of the dopaminergic system in the differential diagnosis and for the determination of the progression rate of Parkinson's disease (PD). D2 receptor imaging can help to differentiate multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) from PD. In patients treated with neuroleptics it is possible to determine the rate of striatal D2 receptor blockade using this technique. This occupancy rate parallels the occurrence of parkinsonian side effects. Its measurement helps in the selection of newer atypical neuroleptics, which can be used to treat drug-induced psychosis in PD because they do not aggravate parkinsonian symptoms. Imaging of dopaminergic neurons with [123I]beta-CIT SPECT or [18F]DOPA PET is a way to visualize and quantify the nigrostriatal dopaminergic lesion in PD. Findings correlate with clinical rating scales and demonstrate the feasibility of detecting the preclinical lesion in patients with hemiparkinson or familial PD. [123I]beta-CIT SPECT can easily distinguish patients with essential tremor and patients with "lower body parkinsonism" due to a subcortical vascular encephalopathy. MSA and PSP cannot be separated from PD with this method alone. Longitudinal studies with [123I]beta-CIT SPECT and [18F]DOPA PET can quantify the progression rate in PD. SPECT results from our own group show a low rate of progression in patients with a long duration of disease and a more marked progression rate in patients with shorter disease duration. In the former group regions in the striatum with higher beta-CIT binding at the time of the first SPECT scan decline faster than regions with lower binding. These findings suggest a curvilinear course of progression which starts at different time points in different striatal regions and which levels off after several years of disease duration. These findings are in line with data from PET studies and underline the importance of an early start of neuroprotective strategies. Preliminary data from PET and SPECT studies in early PD suggest that dopamine agonists might have a slight neuroprotective effect and might slow down the rate of progression of the disease.     

癫痫患者脑SPECT和PET成像研究

SPECT（单光子发射型计算机断层扫描仪）、PET（正电子发射断层与计算机断层成像）是癫痫患者进行术前评估的重要的成像工具。但由于癫痫患者在发作期SPECT时间分辨率差，因此在区分发作起始区和发作扩散区方面不够准确。发作间期FDG--PET低代谢和发作期SPECT灌流变化能较好的弥补这一缺陷。     

SPECT and PET in neurology

Both single photon emission computed tomography (SPECT) and positron emission tomography (PET) are helpful in the practice of neurology. Ictal SPECT is useful to determine the origin of focal seizures in the pre-surgical evaluation. In some centers, it is used to predict the likelihood of massive cerebral swelling after stroke and of cerebral infarction after a subarachnoid hemorrhage. It has also been used to study dopaminergic function in parkinsonian syndromes and in the evaluation of dementia. Given its higher resolution and some other factors, PET is more useful in the evaluation of brain tumors, dementia and the parkinsonian syndromes. It is also useful in the presurgical evaluation of epilepsy.     

PET und SPECT

Clinical Epileptology - Nuklearmedizinische Untersuchungen wie PET und SPECT werden v. a. bei nichtläsionellen Epilepsien in der prächirurgischen Epilepsiediagnostik eingesetzt....     

Clinical contribution of PET neurotransmission imaging in neurological disorders

Imaging neurotransmission in vivo using positron emission tomography (PET) is a rapidly expanding clinical science. The present review summarizes the actual contribution of PET imaging to clinical problems in movement and seizure disorders and dementia.     

Dopamine D2 receptor imaging with SPECT: studies in different neuropsychiatric disorders.

The purpose of the present study is to visualize and quantify dopamine D2 receptors in the living human brain using an 123I-labeled ligand and the single photon emission computerized tomography (SPECT) technique. S-(-)-Iodobenzamide [S-(-)-IBZM] has been shown to be a highly selective ligand with high affinity for D2 receptors in experimental studies. Five millicuries (185 MBq) of 123I-labeled S-(-)-IBZM was administered intravenously to 12 control subjects, 22 parkinsonian patients under L-Dopa therapy, 12 parkinsonian patients without L-Dopa, 10 unmedicated patients with Huntington's disease, and 12 patients under different neuroleptics. Data collection with a rotating double-head scintillation camera started 1 h after injection and lasted for 50 min. In a semiquantitative approach, a ratio was calculated between mean counts per pixel in the striatum and a region in the lateral frontal cortex, which was 1.74 +/- 0.10 in the control group. A marked reduction of this ratio was found in patients with Huntington's disease (1.38 +/- 0.12; p = 0.0001), no significant changes in untreated parkinsonian patients (1.67 +/- 0.14), but a reduction in L-Dopa-treated cases (1.59 +/- 0.13; p = 0.0014). A curvilinear relationship was found between total daily dose of neuroleptics and the reduction of this ratio. Estimated receptor blockade under full neuroleptic treatment was 75-80%. S-(-)-IBZM binding was reduced with increasing age (p less than 0.01). Specific binding was reduced markedly when the racemic mixture of IBZM was used, and no specific binding was seen with the R-(+)-isomer, demonstrating the stereoselectivity of IBZM binding.(ABSTRACT TRUNCATED AT 250 WORDS)     

SPECT and PET in nonlesional epilepsy

Clinical Epileptology - Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are applied in epilepsy mostly during presurgical assessment. Nonlesional focal...     

Functional imaging in Parkinson's disease: activation studies with PET,fMRI and SPECT

Activation studies with positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) represent a powerful tool to study the functional anatomy of Parkinson's disease (PD). Activation studies offer the opportunity to study regional cerebral function in man in vivo under different conditions with the analysis of task specific changes in regional cerebral blood flow (rCBF) with PET or in the blood oxygenation level dependent (BOLD) effect with fMRI. The combination of PET and deep brain stimulation is particularly attractive to study the effects of discrete perturbations at different target structures throughout the basal ganglia-thalamocortical circuitries. The use of rCBF PET and fMRI to study the pathophysiology of PD in the motor and sensory system and mechanisms of dopaminergic therapy as well as surgical interventions will be reviewed.

     

Functional imaging in Parkinson's disease: activation studies with PET,fMRI and SPECT

Activation studies with positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) represent a powerful tool to study the functional anatomy of Parkinson's disease (PD). Activation studies offer the opportunity to study regional cerebral function in man in vivo under different conditions with the analysis of task specific changes in regional cerebral blood flow (rCBF) with PET or in the blood oxygenation level dependent (BOLD) effect with fMRI. The combination of PET and deep brain stimulation is particularly attractive to study the effects of discrete perturbations at different target structures throughout the basal ganglia-thalamocortical circuitries. The use of rCBF PET and fMRI to study the pathophysiology of PD in the motor and sensory system and mechanisms of dopaminergic therapy as well as surgical interventions will be reviewed.     

Viral infection and psychiatric disorders.

A psychiatric population of 94 inpatients and 12 outpatients was investigated on referral to a psychiatric unit in a general hospital for serum antibody titres to several viruses by a complement fixation technique. Of the total population studied, only eight were considered to have antibody titres of possible significance. This result would appear to indicate that viral infection does not play a major part in the causation or precipitation of psychiatric disorders.     

阿尔茨海默病PET/SPECT受体显像的临床研究进展

本综述以阿尔茨海默病(Alzheimer's disease ,AD)为代表的痴呆疾病的中枢神绎系统乙酰胆碱、苯二氮卓类、5-羟色胺、多巴胺及组胺等递质的受体及受体亚型水平的PET／SPECT显像的临床研究进展，揭示PET／SPECT受体显像在AD的病因、病理机制、早期诊断以及药物评价等研究方面的作用，并且对该领域的研究方向提供一些建议。     

SPECT imaging in psychiatry. A review.

In the last two decades, brain imaging has become an integral part of clinical and research psychiatry. Single photon computed emission tomography (SPECT) is rapidly gaining acceptance as one of the major imaging techniques available, along with computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). Each of these techniques has its assets and drawbacks. This review concerns SPECT, a highly prevalent imaging technique whose potential value in brain imaging has not been appreciated until recently. Its purpose is to expose practicing clinicians and research psychiatrists alike to the attributes of this instrument, which is available in most nuclear medicine departments today. An effort is made to provide a comprehensive account of this technique, including a brief summary of the basic principles, the various methods of its application, and recent findings in most psychiatric disorders. Analogies to its "aristocratic cousin," PET, are presented to emphasize similarities and differences. Finally, directions for future development and implementation of SPECT are suggested.