Conectividad funcional a partir de la perfusión cerebral en pacientes epilépticos y con enfermedad de Parkinson / Functional connectivity from cerebral perfusion in patients with epilepsy and Parkinson's disease

Introducción: La epilepsia y la enfermedad de Parkinson han sido descritos como trastornos de redes neurales. El estudio de la conectividad por modalidades moleculares puede ser más relevante fisiológicamente que los basados en señales hemodinámicas. Objetivo: Proponer una metodología para la descripción de patrones de conectividad funcional a partir de la perfusión cerebral por tomografía por emisión de fotón único. Métodos: La metodología incluye cuatro pasos principales: preprocesamiento espacial, corrección del volumen parcial, cálculo del índice de perfusión y obtención de la matriz de conectividad funcional mediante el coeficiente de correlación de Pearson. Se implementó en 25 pacientes con distintos trastornos neurológicos: 15 con epilepsia farmacorresistente y 10 con enfermedad de Parkinson. Resultados: Se encontraron diferencias significativas entre los índice de perfusión de varias regiones de los hemisferios ipsilateral y contralateral tanto en pacientes con epilepsia del lóbulo frontal como en pacientes con epilepsia del lóbulo temporal. Igual resultado se obtuvo en los pacientes con enfermedad de Parkinson con distintos estadios de la enfermedad. Para cada grupo se identificaron patrones de conectividad funcional que involucran a regiones relacionadas con la patología en estudio. Conclusiones: Con el desarrollo de esta metodología se ha demostrado que la tomografía por emisión de fotón único aporta información valiosa para estudiar la organización de las redes funcionales del cerebro. Futuras investigaciones con mayor número de pacientes contribuirían a hacer inferencias sobre los correlatos neurales de los distintos trastornos cerebrales(AU)

Introduction: Epilepsy and Parkinson's disease have been described as disorders of neural networks. The study of connectivity by molecular modalities may be more physiologically relevant than those based on hemodynamic signals. Aim: The aim of the present work is to propose a methodology for the description of functional connectivity patterns from brain perfusion by single photon emission tomography. Methods: The methodology includes four main steps: spatial preprocessing, partial volume correction, calculation of the perfusion index and obtaining the functional connectivity matrix using Pearson's correlation coefficient. It was implemented in 25 patients with different neurological disorders: 15 with drug-resistant epilepsy and 10 suffering Parkinson's disease. Results: Significant differences were found between the perfusion indexes of various regions of the ipsilateral and contralateral hemispheres in both patients with frontal lobe epilepsy and patients with temporal lobe epilepsy. The same result was obtained in Parkinson's disease patients with different stages of the disease. For each group, functional connectivity patterns involving regions related to the pathology under study were identified. Conclusions: With the development of this methodology, it has been demonstrated that single photon emission tomography provides valuable information to study the organization of functional brain networks. Future research with a larger number of patients would contribute to make inferences about the neural correlates of the different brain disorders(AU)

Clinical value of 99mTc-MDP SPECT/CT whole body bone imaging in diagnosis of bone metastasis of pros-tate cancer / 实用医学杂志

Objective To investigate the clinical value of 99mTc-MDP SPECT/CT whole body bone imaging in the diagnosis of bone metastasis of prostate cancer. Methods A total of 107 cases with prostate cancer were di-agnosed by SPECT whole body bone imaging from January 2013 to November 2016. SPECT/CT imaging of some ab-normal density collective focus found in whole body bone imaging were further carried out. Six months later ,whole body bone imaging and SPECT/CT were made again for review. In all diagnosis above ,99mTc-MDP were selected as bone imaging agent. According to the results of follow-up visit clinical and imaging diagnosis ,diagnostic perfor-mance indicators of whole body bone imaging and SPECT/CT were calculated. Results The different part of whole body bone imaging and SPECT/CT in the diagnosis of bone metastases was statistically significant(x2 = 23.000, P < 0.001). The diagnosis specificity and coincidence rate of SPECT/CT for bone metastasis were 100.0% and 98.1% respectively and they were significantly higher than those of whole body bone imaging(65.0% and 80.4%respectively). The differences were statistically significant(P < 0.05). After SPECT/CT diagnosis,a total of 193 undetermined lesions were found and 83 lesions of these were final diagnosed of bone metastases. Pelvic lesions were most in bone metastases ,accounting for 50.6%. Conclusion Whole body bone imaging can effectively determine the undetermined lesions , further SPECT/CT can significantly improve the diagnostic accuracy of prostate cancer bone metastasis.

New molecular targets for PET and SPECT imaging in neurodegenerative diseases / Novos alvos moleculares para tomografia por emissão de pósitrons (PET) e tomografia computadorizada por emissão de fóton único (SPECT) em doenças neurodegenerativas

The pathophysiology of neurodegenerative diseases (ND) such as Alzheimer's disease (AD) and Parkinson's disease (PD) has not yet been completely elucidated. However, in the past few years, there have been great knowledge advances about intra-and extracellular proteins that may display impaired function or expression in AD, PD and other ND, such as amyloid beta (Aβ), α-synuclein, tau protein and neuroinflammatory markers. Recent developments in the imaging techniques of positron emission tomography (PET) and single photon emission computed tomography (SPECT) now allow the non-invasive tracking of such molecular targets of known relevance to ND in vivo. This article summarizes recent findings of PET and SPECT studies using these novel methods, and discusses their potential role in the field of drug development for ND as well as future clinical applications in regard to differential diagnosis of ND and monitoring of disease progression.

A fisiopatologia das doenças neurodegenerativas (DN), tais como a doença de Alzheimer (DA) e a doença de Parkinson (DP), ainda não é completamente compreendida. No entanto, nos últimos anos, houve grandes avanços em termos do conhecimento sobre proteínas intra e extracelulares, tais como beta-amiloide (Aβ), α-sinucleína, proteína tau e marcadores neuroinflamatórios, que podem ter sua função ou expressão prejudicada na DA, DP ou em outras DN. Progressos recentes nas técnicas de tomografia por emissão de pósitrons (PET) e tomografia computadorizada por emissão de fóton único (SPECT) permitem hoje em dia a identificação não invasiva de tais alvos moleculares in vivo. Este artigo resume descobertas recentes de estudos de PET e SPECT cerebral usando esses alvos moleculares inovadores e discute o papel potencial dessas técnicas no campo do desenvolvimento de novos medicamentos para as DN, bem como futuras aplicações clínicas em relação ao diagnóstico diferencial e monitoramento da progressão dessas doenças.

Clinical Significance of Reverse Redistribution Phenomenon on Delayed Tc-99m Tetrofosmin Myocardial Perfusion Imaging in Patients with Acute Myocardial Infarction / 핵의학분자영상

PURPOSE: This study was performed to investigate the clinical significance of reverse redistribution (RR) phenomenon detected on delayed Tc-99m tetrofosmin myocardial single photon emission computed tomography (SPECT) in patients with acute myocardial infarction after revascularization. MATERIALS AND METHODS: A Tc-99m tetrofrosmin myocardial SPECT was performed in 67 consecutive patients after revascularization for acute myocardial infarction. Myocardial SPECT imaging was performed for early imaging at 40 min and for delayed imaging at 180 min after reinjection at myocardial stress. Regional myocardial uptakes were scored by 4-point scoring in the left ventricular wall divided into 17 segments. Reverse redistribution was defined as an increase of more than 2 point in the activity score on the delayed image. Follow-up myocardial SPECT and coronary angiography (CAG) were performed 9 months later. RESULTS: On myocardial SPECT performed following revascularization, RR was observed in 100 of all 319 segments (31%) and in 43 patients (64%). The abnormalities of perfusion and regional wall motion were more severe in the patients with RR compared to those without RR (p<0.05). On follow-up myocardial SPECT, the myocardial perfusion, regional wall motion, and myocardial thickness were significantly improved in the patients with RR (p<0.05) however, these changes were not significant in those without RR. There was no significant difference between the patients with RR and those without RR in the occurrence of restenosis on CAG. CONCLUSIONS: In patients with acute myocardial infarction, the regions showing the RR phenomenon on delayed Tc-99m tetrofosmin SPECT may reflect viable myocardium and indicate recovery of salvaged myocardium.

Crossed Cerebellar Hyperperfusion on Ictal Tc-99m HMPAO Brain SPECT: Clinical Significance for Differentiation of Mesial or Lateral Temporal Lobe Epilepsy and Related Factors for Development / 대한핵의학회잡지

PURPOSE: The aim of this study was to determine whether crossed cerebellar hyperperfusion (CCH) was helpful in discriminating mesial from lateral temporal lobe epilepsy (TLE) and what other factors were related in the development of CCH on ictal brain SPECT. MATERALS AND METHODS: We conducted retrospective analysis in 59 patients with TLE (M:41, F:18; 27.4+/-7.8 years old; mesial TLE: 51, lateral TLE: 8), which was confirmed by invasive EEG and surgical outcome (Engel class I , II). All the patients underwent ictal Tc-99m HMPAO brain SPECT and their injection time from ictal EEG onset on video EEG monitoring ranged from 11 sec to 75 sec (32.6+/-19.5 sec) in 39 patients. Multiple factors including age, TLE subtype (mesial TLE or lateral TLE), propagation pattern (hyperperfusion localized to temporal lobes, spread to adjacent lobes or contralateral hemisphere) and injection time were evaluated for their relationship with CCH using multiple logistic regression analysis RESULTS: CCH was observed in 18 among 59 patients. CCH developed in 29% (15/51) of mesial TLE patients and 38% (3/8) of lateral TLE patients. CCH was associated with propagation pattern; no CCH (0/13) in patients with hyperperfusion localized to temporal lobe, 30% (7/23) in patients with propagation to adjacent lobes, 48% (11/23) to contralateral hemisphere. Multiple logistic regression analysis revealed that propagation pattern (p=0.01) and age (p=0.02) were related to the development of CCH. CONCLUSION: Crossed cerebellar hyperperfusio ictal brain SPECT did not help differentiate mesial from lateral temporal lobe epilepsy. Crossed cerebellar hyperperfusion was associated with propagation pattern of temporal lobe epilepsy and age.

A Case of Neuro-Behcet's Disease: Comparison of Neurological Symptoms with PET, SPECT, and MRI Findings / 대한핵의학회잡지

We describe a 27-year-old man who developed gait disturbance and dysarthria 2 years after the onset of cardinal symptoms of Behcet's disease. Positron emission tomography with 18F-fluorodeoxyglucose revealed severe hypometabolism in the cerebellum, in accordance wih cerebellar symptoms and sign of the patient. However, single-photon emission tomography with Tc-99m-HMPAO and Tc-99m-ECD did not disclose significant perfusion abnormalities in the brain. Routine brain magnetic resonance imaging did not show signal abnormalities. The findings of imaging studies compared with neurological manifestations of the patient are discussed.