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)

Comparison of continuous bed motion and step-and-shoot acquisition modes in 18F-FDG PET/CT imaging / 中华核医学与分子影像杂志

Objective To investigate the differences of acquisition protocols from continuous bed motion (CBM) and step-and-shoot (SS) modes and to observe their effects on image quality and standard uptake value (SUV) in 18 F-fluorodeoxyglucose (FDG) PET/CT.Methods A total of 30 patients (13 males,17 females;40-71 years) who underwent 18F-FDG PET/CT from June 2017 to September 2017 were selected.Simulated acquisition protocols for a specific range (upper margin of the skull to the lower edge of sciatic bone) were established with CBM and SS modes.The differences between 2 modes for actual length requiring for a specific acquisition range and the differences in CT radiation dose were compared.Real PET/ CT scans were performed using CBM and SS modes consecutively,and the differences in image quality and SUV were compared.Paired t test andx2 test were used to analyze the data.Results For the specific acquisition range,the average acquisition length of CBM was reduced by 6.65％ ((87.11 ± 3.78) vs (93.32 ±6.02) cm;t=-7.737,P＜0.001) and the CT radiation dose was reduced by 6.88％ ((812±170) vs (872±192) mGy · cm;t=-6.432,P＜0.001) for each patient compared with the results of SS.There were no significant differences in maximum SUV (SUVmax) and mean SUV (SUVmean) between SS and CBM in normal tissues including liver,bone and waist muscles (t values:from-1.895 to 0.132,all P＞0.05).The SUVmax of leg muscles at the end of the image was significantly higher in SS than that in CBM (1.24±0.53 vs 1.06±0.42;t=3.450,P＜0.01).There were no statistically significant differences in SUVmax and SUV between SS and CBM in 40 FDG high uptake lesions (t values:0.420 and-0.260,both P＞0.05).There were 73.33％ (22/30) patients had images with overall high quality during SS and the percentage was 80.00％ (24/30) during CBM (x2 =0.373,P＞0.05).The percentage of patients with images of high quality at the end was 16.67％(5/30) during SS,which was significantly less than that during CBM (63.33％,19/30;x2 =13.611,P＜0.001).Conclusions For the specific acquisition range,CBM can reduce unnecessary CT scan range and radiation dose compared with SS.There is no significant difference in image quality and SUV from normal tissue and lesion except for the end of the image.

Relationship between image quality of PET/CT in automatic tube current modulation and effective dose / 中华核医学与分子影像杂志

Objective To investigate the relationship between image quality of PET/CT in automatic tube current modulation and effective dose(ED) of patients and to determine the optimal acquisition scheme.Methods Scanning was performed on anthropomorphic phantom RS-550 using GE Discovery ST-16 or Discovery Elite PET/CT.The same CT acquisition conditions was used:tube voltage 120 kV,pitch 1.375,rotation speed 0.8 s,noise index ranged from 8 to 30,interval 2,automatic tube current low limit 30 mA,high limit ranged from 200 to 350 mA,interval 50 mA.The images were analyzed,and the noise,signal to noise ratio (SNR) and figure of merit (FOM) of main organs in the abdomen were calculated.The relationship between image quality and ED was analyzed.Two-sample t test was used for data analysis.Results The noise of each organ decreased significantly along with the increase of ED until the ED of ST-16 increased to 15 mSv or Elite increased to 12 mSv,then the image noise decreased gently.SNR of each organ image increased along with the increase of ED.The FOM of liver decreased along with the increase of ED,while the FOM of other organs did not change significantly with ED.All image indicators of Elite PET/CT were better than ST-16 PET/CT at the same ED (5-20 mSv),though there was no significant difference (t:0.133-4.701,all P＞0.05).When ED was 5 mSy,the noise of liver with ST-16 was 12.0％ (28.9 vs 25.8)higher than that with Elite,and the SNR and FOM of liver with Elite was 13.9％ (4.1 vs 3.6) and 66.7％ (0.50 vs 0.30) higher than that with ST-16,respectively.Conclusion When the ED caused by the 2 PET/CT systems was between 5-20 mSy,the image quality is improved along with the ED increasing in a certain range.

68Ga-NOTA-NFB PET/CT imaging in breast cancer: clinical study of a new targeted agent for chemokine receptor 4 / 中华核医学与分子影像杂志

Objective To investigate the clinical application of chemokine receptor 4 (CXCR4)-targeted PET/CT imaging in breast cancer using 68Ga-1,4,7-triazacyclononane-1,4,7-triacetic acid-TN14003 (NOTA-NFB) and the correlation between 68Ga-NOTA-NFB uptake and pathology.Methods From June 2014 to December 2014,11 female patients (age range:38-68 years) with non-specific invasive breast cancer were recruited in this study.All patients underwent neoadjuvant chemotherapy before surgery.68GaNOTA-NFB and 18F-fluorodeoxyglucose (FDG) PET/CT imaging were performed before the chemotherapy.Three patients also underwent 68Ga-NOTA-NFB PET/CT imaging after the fourth cycle of chemotherapy.The region of interest (ROI) method was used to measure the maximum standardized value (SUVmax) and tumor/non-tumor (T/NT) ratio was calculated.Paired t test and Spearman correlation analysis were used for statistical analysis.Results The SUVmax values of primary lesions were 3.78±2.03 and 8.11±5.14 (t=-3.01,P＜0.05) respectively in 68Ga-NOTA-NFB imaging and 18F-FDG imaging.The T/NT ratios for primary lesions were not significantly different between the two imaging methods (9.36±7.81 vs 15.62±14.51;t=-1.63,P＞0.05).In the metastatic lymph nodes,SUVmax values were not significantly different between 68Ga-NOTA-NFB imaging and 18F-FDG imaging (t=-2.02,P＞0.05),but T/NT ratios were significantly different (t=-2.43,P＜0.05).After neoadjuvant chemotherapy,T/NT ratios were decreased in the 3 patients.Correlation was not found between T/NT in 68Ga-NOTA-NFB imaging and Ki-67,but the P value was close to 0.05 (rs =0.600,P=0.051).Conclusion 68Ga-NOTA-NFB PET/CT can be used as a new CXCR4-targered imaging in diagnosis of breast cancer,and it may be beneficial to evaluate the effect of neoadjuvant chemotherapy.

A model of malignant risk prediction for solitary pulmonary nodules on 18F-FDG PET/CT: building and estimating / 中华核医学与分子影像杂志

Objective To develop a model of malignant risk prediction of solitary pulmonary nodules(SPN) with the metabolic characteristics of the lesion.Methods A total of 362 patients (291 malignant cases and 71 benign cases;194 males,168 females;median age:61 years) who underwent PET/CT imaging from January 2013 to July 2017 were analyzed.The diagnosis of malignant SPN was based on pathological results,and that of benign SPN was based on pathological or follow-up results.Differences of clinical/imaging characteristics in patients with benign and those with malignant SPN were analyzed.Risk factors were screened by multivariate non-conditional logistic regression analysis.The self-verification of the model was done by the receiver operating characteristic (ROC) curve analysis,out-of-group verification was performed by k-fold cross-validation.Results There were statistically significant differences in age,maximum standardized uptake value (SUVmax),size,lobulation,spiculation,pleural traction,vessel connection,calcification,vacuole,and emphysema between patients with benign and malignant nodules (all P＜0.05).The risk factors for malignant nodules included age,SUVmax,size,lobulation,calcification and vacuole.The odds ratio (OR) values (95％ CI) were 1.040(1.007-1.075),1.612(1.287-2.017),1.149(1.074-1.230),4.650(2.138-10.115),0.216(0.085-0.548),and 3.043(1.302-7.111),respectively.The logistic regression model was as follows:P=1/(1+e-x),x=-5.583+0.039×age+0.477×SUVmaxx+0.139×size+1.537×lobulation-1.532×calcification+ 1.1 13×vacuole.The estimated area under the curve (AUC) for the model was 0.915(95％ CI:0.883-0.947),sensitivity was 89.7％,specificity was 78.9％.K-fold cross-validation showed that the training accuracy was 0.899±0.011,the predictive accuracy was 0.873±0.053.Conclusions The risk factors for malignant nodules included age,SUVmax,size,lobulation,calcification and vacuole.After verification,the model has a satisfactory accuracy.It may help clinics make accurate decisions.

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.