El dilema clínico frente a los pacientes con ergometría positiva y prueba de perfusión miocárdica con SPECT normal / The clinical dilemma facing patients with positive stress test and normal SPECT myocardial perfusion imaging

La evaluación de la perfusión miocárdica con SPECT combina una prueba de esfuerzo (ergometría o estrés farmacológico) junto a imágenes de perfusión con radioisótopos. Este estudio es útil para establecer el diagnóstico de enfermedad arterial coronaria, estratificar el riesgo de infarto y tomar decisiones terapéuticas. Un resultado normal aporta un alto valor predictivo negativo, es decir, una muy baja probabilidad de que el paciente presente eventos cardiovasculares. El hallazgo de signos de isquemia en la ergometría podría poner en jaque el valor predictivo negativo de una perfusión normal. En presencia de este resultado, el paso siguiente es evaluar los predictores de riesgo en la ergometría, el riesgo propio del paciente en función de los antecedentes clínicos y el puntaje cálcico coronario, cuando este se encuentra disponible. Ante la presencia concomitante de otros marcadores de riesgo se sugiere completar la evaluación con un estudio anatómico.El uso de nuevas tecnologías podría mejorar la precisión en la predicción de eventos. (AU)

Assessment of myocardial perfusion with SPECT combines a stress test (ergometry or pharmacological stress) with radioisotope perfusion imaging. This test is helpful to diagnose coronary artery disease, stratify the risk of heart attack, and make therapeutic decisions. A normal result provides a high negative predictive value; therefore, the probability of cardiovascular events is very low. Signs of ischemia on an ergometry could jeopardize the negative predictive value of normal perfusion. In this clinical setting, the next step is to evaluate the risk predictors in the stress test, the individual risk based on the clinical history, and the coronary calcium score when available. Given the simultaneous presence of other risk markers,completing the evaluation with an anatomical study is suggested. The use of new technologies could improve the accuracy of event prediction. (AU)

Dual x-ray absorptiometry monitoring in pediatric short bowel syndrome: an integrative review / Monitorização por absortometria com duplo raio X na síndrome do intestino curto pediátrica: uma revisão integrativa

ABSTRACT Objective: To analyze the bone health of pediatric patients with short bowel syndrome intestinal failure (SBS-IF). Data source: An integrative literature review was performed using the data published in the MEDLINE-PubMed and Scientific Electronic Library Online (SciELO) databases between January 2010 and April 2021, and through a manual search of the reference lists of relevant studies. Studies were included if they assessed bone mineral density by the Dual X-Ray Absorptiometry (DXA) technique, incorporated pediatric patients (up to 20 years of age) with SBS under parenteral nutrition (PN) and were written in English. Eleven primary sources met the inclusion criteria for this study. Data synthesis: Pediatric patients with SBS-IF under long-term parenteral nutrition experienced frequent changes in bone metabolism, leading to osteoporotic fractures and growth failure. These patients have deficiencies in multiple nutrients, such as calcium, magnesium, phosphorus, and vitamin D. Consequently, there are variations in the secretion and regulation of the parathyroid hormone. In addition, the pharmacotechnical limitations related to calcium and phosphorus in the PN solution, use of glucocorticoids, and difficulty performing physical activity are risk factors for the development of metabolic bone disease in pediatric patients with SBS-IF. Conclusions: Low bone mineral density was associated with a high risk of developing osteoporosis, fractures, and growth deficiency in pediatric patients with SBS-IF on PN therapy in the long term.

Objetivo: Analisar a saúde óssea de pacientes pediátricos com síndrome do intestino curto — falência intestinal (SIC-FI). Fontes de dados: Revisão integrativa da literatura usando os dados publicados nas bases de dados Medical Literature Analysis and Retrieval System Online/ United States National Library of Medicine (MEDLINE/PubMed) e Scientific Electronic Library Online (SciELO) entre janeiro de 2010 e abril de 2021 e por meio de busca manual nas listas de referências de estudos relevantes. Foram incluídos estudos em inglês que avaliaram a densidade mineral óssea pela técnica de absorciometria de raio X duplo (DXA), incluíram pacientes pediátricos (até 20 anos de idade) com SIC sob terpia nutricional parenteral. Onze fontes primárias preencheram os critérios de inclusão para este estudo. Síntese dos dados: A pesquisa revelou que pacientes pediátricos com SIC-FI sob nutrição parenteral (NP) de longo prazo tiveram alterações frequentes no metabolismo ósseo, levando a fraturas osteoporóticas e falha de crescimento. Esses pacientes apresentam deficiências de múltiplos nutrientes, como cálcio, magnésio, fósforo e vitamina D. Consequentemente, houve variações na secreção e regulação do hormônio da paratireoide. Além disso, as limitações farmacotécnicas relacionadas ao cálcio e fósforo na solução de NP, o uso de glicocorticoides e dificuldade para realizar atividade física são fatores de risco para o desenvolvimento de doença óssea metabólica em pacientes pediátricos com SIC-FI. Conclusões: A baixa densidade mineral óssea foi associada a um alto risco de desenvolver osteoporose, fraturas e deficiência de crescimento em pacientes pediátricos com SIC-FI sob terapia nutricional parenteral em longo prazo.

Validation of automated image co-registration integrated into in-house software for voxel-based internal dosimetry on single-photon emission computed tomography images / Validação do corregistro automático de imagem integrado a software de análise de dosimetria interna baseada em voxel para tomografia computadorizada de emissão de fóton único

Abstract Objective: To develop an automated co-registration system and test its performance, with and without a fiducial marker, on single-photon emission computed tomography (SPECT) images. Materials and Methods: Three SPECT/CT scans were acquired for each rotation of a Jaszczak phantom (to 0°, 5°, and 10° in relation to the bed axis), with and without a fiducial marker. Two rigid co-registration software packages-SPM12 and NMDose-coreg-were employed, and the percent root mean square error (%RMSE) was calculated in order to assess the quality of the co-registrations. Uniformity, contrast, and resolution were measured before and after co-registration. The NMDose-coreg software was employed to calculate the renal doses in 12 patients treated with 177Lu-DOTATATE, and we compared those with the values obtained with the Organ Level INternal Dose Assessment for EXponential Modeling (OLINDA/EXM) software. Results: The use of a fiducial marker had no significant effect on the quality of co-registration on SPECT images, as measured by %RMSE (p = 0.40). After co-registration, uniformity, contrast, and resolution did not differ between the images acquired with fiducial markers and those acquired without. Preliminary clinical application showed mean total processing times of 9 ± 3 min/patient for NMDose-coreg and 64 ± 10 min/patient for OLINDA/EXM, with a strong correlation between the two, despite the lower renal doses obtained with NMDose-coreg. Conclusion: The use of NMDose-coreg allows fast co-registration of SPECT images, with no loss of uniformity, contrast, or resolution. The use of a fiducial marker does not appear to increase the accuracy of co-registration on phantoms.

Resumo Objetivo: Desenvolver corregistro automático e testar seu desempenho com ou sem marcador fiducial em imagens de tomografia computadorizada de emissão de fóton único (SPECT). Materiais e Métodos: Três SPECT/CTs foram adquiridas para cada rotação de um simulador de Jaszczak em relação ao eixo da maca (0°, 5° e 10°), com e sem fiducial. Dois métodos de corregistro inelástico foram aplicados - SPM12 e NMDose-coreg -, e a porcentagem do erro quadrático médio (%RMSE) foi usada para analisar a qualidade do corregistro. Uniformidade, contraste e resolução foram medidos antes e após o corregistro. NMDose com corregistro automático foi usado para calcular a dose renal de 12 pacientes tratados com 177Lu-DOTATATE e comparado com OLINDA/EXM. Resultados: A marcação fiducial não modificou a qualidade do corregistro das imagens SPECT, medida pela %RMSE (p = 0,40). Não houve impacto na uniformidade, contraste e resolução após o corregistro de imagens adquiridas com ou sem fiduciais. Aplicação clínica preliminar mostrou tempo total de processamento de 9 ± 3 min/paciente para NMDose e 64 ± 10 min/paciente para OLINDA/EXM, com alta correlação entre ambos, apesar de menor dose renal em NMDose. Conclusão: NMDose-coreg permite o corregistro rápido de imagens SPECT, sem perda de uniformidade, contraste ou resolução. O uso da marcação fiducial não aumentou a precisão do corregistro em fantomas.

Research progress of intravital microscopy of the pulmonary immune environment / 中国胸心血管外科临床杂志

@#The development of intravital microscopy (IVM) has enabled researchers to perform in-situ, real-time observations of pulmonary micro-circulation at the cellular level, and has become instrumental for researching the immune micro-environment of pulmonary diseases. This article introduces the developments in constructing the pulmonary imaging window and summarizes the current light microscopy techniques used for lung IVM with regard to its relevant functional and application features, which includes wide field fluorescence microscopy, confocal microscopy, as well as two-photon microscopy. It then provides examples of IVM of pulmonary immune response in inflammation and infection in murine models, and finally specifies the technological limitations to provide reference for researchers to systematically learn and understand the technology.

Application of 99Tc m-MIBI SPECT/CT imaging in patients with primary cervical dystonia / 中华核医学与分子影像杂志

Objective:To evaluate the value of 99Tc m-methoxyisobutylisonitrile(MIBI) SPECT/CT imaging for the identification of dystonic muscles in patients with primary cervical dystonia (PCD). Methods:A total of 10 patients with PCD (3 males, 7 females, age (47.3±9.9) years) and 10 healthy subjects (4 males, 6 females, age (43.5±9.4) years; control group) between August 2019 and October 2021 in China-Japan Friendship Hospital were enrolled prospectively. All subjects underwent 99Tc m-MIBI SPECT/CT scan. The SUV max of 8 bilateral representative muscles, including rectus capitis posterior major, obliquus capitis inferior, splenius capitis, semispinalis, sternocleidomastoid, trapezius, musculus scalenus muscle and levator scapulae were evaluated in control group. In PCD group, muscles with abnormal uptake were determined. ROI was drawn and SUV max was measured. Independent-sample t test was used to analyze the differences of SUV max between normal and abnormal muscles. The detecting rates of neck MRI and SPECT/CT for abnormal muscles were analyzed by χ2 test. Results:Normal muscles of healthy subjects showed mild symmetrical radioactivity distribution, with the SUV max of 1.10±0.19. A total of 60 muscles with abnormal uptake in 10 patients were found, including 7 rectus capitis posterior major, 10 obliquus capitis inferior, 8 splenius capitis, 8 semispinalis, 10 sternocleidomastoid, 5 trapezius, 3 musculus scalenus muscle and 9 levator scapulae. The SUV max of muscles with abnormal uptake was 1.81±0.43, which was higher than that of normal muscles ( t=17.05, P<0.001). Only 30 pieces abnormal hypertrophy muscle were found by neck MRI, and the detecting rate was much lower than that of SPECT/CT (18.75%(30/160) vs 37.50%(60/160); χ2=28.03, P<0.001). Conclusion:99Tc m-MIBI SPECT/CT may be a useful method for identifying dystonic muscles and a guide to precision therapy in patients with PCD.

Value of SPECT myocardial perfusion imaging and coronary flow reserve combined with coronary artery calcium score in the diagnosis of obstructive coronary artery disease / 中华核医学与分子影像杂志

Objective:To study the value of myocardial perfusion imaging (MPI) and coronary flow reserve (CFR) combined with coronary artery calcium score (CACS) in the diagnosis of obstructive coronary artery disease (CAD).Methods:From January 2019 to December 2020, 96 confirmed or suspective CAD patients (65 males, 31 females; age: 30-81 years) who completed rest/stress MPI, CFR and CACS defection in Fuwai Central China Cardiovascular Hospital were retrospectively analyzed. Coronary angiography (CAG) was used as the diagnostic standard to calculate the sensitivity and accuracy of MPI, CFR and MPI/CFR combined with CACS in the diagnosis of CAD. The χ2 test was used to compare the diagnostic efficiency of different methods. Results:The diagnostic sensitivity of MPI was 76.06%(54/71), and the accuracy was 75.00%(72/96), while the sensitivity increased to 97.18%(69/71; χ2=13.67, P<0.001) and the accuracy increased to 87.50%(84/96; χ2=4.92, P=0.020) with significant differences after combined with CACS. The sensitivity and accuracy of CFR were 91.55%(65/71)and 87.50%(84/96), which increased to 97.18%(69/71; χ2=2.12, P=0.137) and 89.58%(86/96; χ2=0.21, P=0.411) with no significant differences after combined with CACS. The sensitivity of MPI in the diagnosis of three-vessel CAD was 70.00%(21/30), which increased to 100%(30/30; χ2=7.75, P=0.004) after combined with CACS; while the sensitivity of MPI combined with CACS in the diagnosis of single-vessel and double-vessel CAD were not significantly improved ( χ2 values: 3.29, 1.51, P values: 0.114, 0.416). Conclusion:The combination of MPI and CACS can significantly improve the diagnostic efficiency of CAD, contributed by the improvement of the diagnostic sensitivity in three-vessel disease; whereas the diagnostic efficiency of CFR for CAD is not significantly improved after combined with CACS.

Establishment of the normal reference values of left ventricular function parameters evaluated by CZT SPECT stress gated myocardial perfusion imaging in low-likelihood of stable coronary artery disease / 中华核医学与分子影像杂志

Objective:To establish the normal reference value of left ventricular function parameters by cadmium-zinc-tellurium (CZT) SPECT stress gated myocardial perfusion imaging (G-MPI) in low-likelihood of stable coronary artery disease (SCAD).Methods:From March 2022 to August 2022, 348 consecutive SCAD patients (146 males, 202 females, age (58±10) years) who underwent exercise or pharmacological stress G-MPI (CZT SPECT) in Beijing Anzhen Hospital, Capital Medical University were retrospectively recruited. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), and left ventricular ejection fraction (LVEF) were acquired using quantitative gated SPECT (QGS) analysis. EDV and ESV were corrected by body surface area (BSA) to obtain EDV index (EDVI) and ESV index (ESVI), respectively. Independent-sample t test, one-way analysis of variance and Mann-Whitney U test were used for data analysis. The influences of EDV, ESV, EDVI, ESVI and LVEF were analyzed by multiple regressions for linear models. Results:There were 314 patients with low-likelihood of SCAD (128 males, 186 females, age (58±10) years) and 34 normal controls (18 males, 16 females, age (55±10) years). There were no significant differences of basic clinical characteristics and left ventricular function parameters in different genders between 2 groups ( z values: from -1.74 to -0.02, t values: from -1.16 to 1.17, all P>0.05). Using the 95% CI as the cut-off value for left ventricular function parameters in patients with a low-likelihood of SCAD, the upper limits of EDV, ESV, EDVI and ESVI in females and males were 84 and 111 ml, 30 and 44 ml, 47 and 54 ml/m 2, 17 and 21 ml/m 2, respectively, and the lower limit of LVEF in females and males were 58% and 55%, respectively. In the low-likelihood of SCAD group, the EDV ((58±13) vs (77±17) ml) and ESV ((16±7) vs (26±9) ml) of females were smaller than those of males ( t values: 10.65, 10.35, both P<0.001), while LVEF of females was higher than that of males ((72±7)% vs (67±6)%; t=-6.23, P<0.001). However, there were no significant differences in left ventricular function parameters among different age groups with the same gender ( F values: 0.12-2.19, all P>0.05). Based on multiple regression for linear models, the primary predictors of EDV, ESV and LVEF were gender and weight ( β values: from -0.380 to 0.358, all P<0.05). Conclusions:Normal reference values of left ventricular function parameters are established by CZT SPECT stress G-MPI in low-likelihood of SCAD patients. Left ventricular EDV and ESV of females are smaller than those of males, while LVEF of females is higher than that of males. The influence of gender on left ventricular function parameters should be considered in clinical practice.

Relationship between coronary flow reserve by CZT SPECT and invasive coronary fractional flow reserve and its potential clinical value / 中华核医学与分子影像杂志

Objective:To evaluate the relationship between regional coronary flow reserve (CFR) obtained from cadmium-zinc-telluride SPECT(CZT SPECT) myocardial functional perfusion imaging (MFPI) and invasive fractional flow reserve (FFR) measured during coronary angiography (CAG) and its clinical value in guiding coronary interventions.Methods:Forty-two patients (30 males, 12 females, age (63.3±9.8) years) who completed CZT SPECT MFPI in the First Affiliated Hospital of Nanjing Medical University from June 2022 to September 2022 and underwent CAG within 3 months were included retrospectively. The concordance of CFR and FFR for diagnosing myocardial ischemia (CFR<2.0 and FFR<0.8) was calculated at the vascular level. The diagnostic efficacy of coronary stenosis≥70% for decreased myocardial blood flow (CFR<2.0) was calculated. Kappa test was used to analyze the data. Results:A total of 126 major coronary arteries were identified in 42 patients, of which 30(23.8%) had a CFR<2.0 by CZT SPECT and 33(26.2%) had stenosis≥70% in CAG. A total of 32 coronary vessels were performed with MFPI CFR and FFR measurements, of which 6 were both decreased and 21 were both normal, so the concordance rate was 84.4%(27/32)( Kappa=0.612, P<0.001). Among 33 coronary vessels with stenosis≥70%, 13 were with CFR≥2.0. Among 30 coronary vessels with CFR<2.0, 10 were with stenosis<70%. When using stenosis≥70% to diagnose CFR decreasing, the sensitivity was 66.7%(20/30), specificity was 86.5%(83/96), positive predictive value was 60.6%(20/33), negative predictive value was 89.2%(83/93), and accuracy was 81.7%(103/126). Conclusions:The concordance between CFR and FFR for the diagnosis of myocardial ischemia is good. Nearly 1/3 of the coronary arteries with decreased CFR have stenosis<70%, whereas nearly 40% of the coronary arteries with stenosis≥70% are not result in myocardial ischemia. Regional CFR determined by CZT SPECT may have potentially significant clinical value in the diagnosis of coronary artery disease and decision-making of coronary intervention.

Evaluation of the efficacy of balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension using pulmonary perfusion tomography imaging / 中华核医学与分子影像杂志

Objective:To evaluate the efficacy of balloon pulmonary angioplasty (BPA) in chronic thromboembolic pulmonary hypertension (CTEPH) using 99Tc m-macroaggregated albumin (MAA) pulmonary perfusion tomography imaging. Methods:Twenty-five patients (4 males, 21 females; age (56.5±12.3) years) with CTEPH who underwent BPA from January 2017 to April 2020 in Beijing Chaoyang Hospital, Capital Medical University were enrolled retrospectively. Effect of BPA on the improvement of pulmonary lobe/pulmonary segment perfusion was analyzed, and the proportions of improved and unimproved pulmonary lobe/pulmonary segment perfusion by BPA were calculated. The percentages of perfusion defect scores (PPDs%) of lung perfusion tomography imaging before BPA and after 4-6 times BPA were compared and analyzed (paired t test). The correlations between PPDs% and mean pulmonary artery pressure (mPAP) before BPA and after BPA were analyzed respectively, and the correlation between decreased percentage of PPDs% and decreased percentage of mPAP after BPA were also analyzed (Pearson correlation analysis). Results:Among 150 lobes of 25 patients, 96.00%(144/150) lobes showed perfusion abnormalities before BPA. After BPA, 11.11%(16/144) showed complete improvement, 57.64%(83/144) showed partial improvement, and 31.25%(45/144) showed no improvement. Among 450 pulmonary segments of 25 patients, 62.44%(281/450) showed perfusion abnormalities before BPA. After BPA, 30.60%(86/281), 37.37%(105/281), 32.03%(90/281) showed complete, partial and no improvement, respectively. The post-BPA PPDs% was significantly lower than that of pre-BPA ((39.08±10.88)% vs (57.88±10.46)%; t=10.40, P<0.001). The post-BPA mPAP was significantly lower than that of pre-BPA ((32.36±10.57) vs (49.08±10.23) mmHg; 1 mmHg=0.133 kPa; t=10.25, P<0.001). There was no significant correlation between PPDs% and mPAP either before BPA ( r=0.01, P=0.953) or after BPA ( r=0.27, P=0.199), but there was a positive correlation between the changes of PPDs% and mPAP ( r=0.40, P=0.045). Conclusions:BPA can significantly improve the pulmonary perfusion and reduce mPAP in CTEPH patients. Pulmonary perfusion tomography imaging can be used to evaluate the efficacy of BPA in CTEPH.

Deterministic method of photon radiotherapy dose calculation / 中华放射肿瘤学杂志

Deterministic method is a numerical calculation method based on photon-electron coupled transport with high computational accuracy and speed, which has been widely applied in photon radiotherapy dose calculation in recent years. However, this method has been introduced into radiotherapy for only a short period of time, which has been rarely studied in China, and systematic understanding of its characteristics is still lacking. In this article, the principles of deterministic method, current development state and clinical application were reviewed, aiming to provide reference for carrying out relevant research.

Correlation of BUA, SOS, T-score and SI with bone mineral density in elderly women with knee osteoarthritis and their diagnostic efficacy in osteoporosis / 中国医师杂志

Objective:To analyze the broadband ultrasound attenuation (BUA), speed of sound (SOS), standard deviation of bone density (T-Score) and stiffness index (SI) with bone mineral density (BMD) in elderly female patients with knee osteoarthritis and their diagnostic efficacy of osteoporosis.Methods:Fifty elderly female patients with knee osteoarthritis admitted o Tangshan People′s Hospital from January 2021 to January 2022 were selected as the observation group, and 40 healthy female patients during the same period were selected as the control group. The results of BUA, SI, T-score and SOS in observation group and control group were analyzed and compared. The BUA, SI, T-score and SOS in elderly women with knee osteoarthritis at different ages and with different bone densities were compared, and the diagnostic value of BUA, SI, T-score and SOS in osteoporosis was analyzed by receiver operating characteristic (ROC) curve.Results:The BUA, SI and T-score of observation group were lower than that in the control group, while SOS was higher than that in the control group (all P<0.05). Among elderly female patients with knee osteoarthritis of different ages, the older the age, the lower the BUA, SI and T-score (all P<0.05), while there was no statistical significance in SOS of elderly female patients with knee osteoarthritis of different ages ( P>0.05). In elderly women with knee osteoarthritis with different BMD grades, the BUA, SI, and T-score in the osteoporosis group were lower than those in the osteopenia group and the normal bone group, and the BUA, SI, and T-score in the osteopenia group were lower than those in the normal bone group; the SOS in the osteoporosis group was higher than those in the osteopenia group and the normal bone group, and the SOS in the osteopenia group was higher than those in the normal bone group (all P<0.05). BUA, SOS, T-score and SI had high sensitivity and specificity in the diagnosis of osteoporosis in elderly women with knee osteoarthritis (all P<0.05). Conclusions:BMD in elderly women with knee osteoarthritis is associated with BUA, SI, T-score, and SOS, and has high diagnostic value for osteoporosis.

Ambient dose equivalent in 99mTcO4- single photon emission computed tomography of the thyroid among patients with hyperthyroidism / 预防医学

Objective@#To investigate the changes of ambient dose equivalent rate in 99mTcO4- single photon emission computed tomography (SPECT) of the thyroid among patients with hyperthyroidism, so as to provide insights into radiation protection guidance.@*Methods@#Patients with hyperthyroidism who underwent 99mTcO4- SPECT of the thyroid in a tertiary hospital were enrolled. The ambient dose equivalent rate was measured at different time points following 99mTcO4- infection and at sites with different distances from patients' neck, and the effects of time post-injection, distance from patients' neck, 24-hour thyroidal radioiodine uptake and thyroid weight on the ambient dose equivalent rate were examined using a generalized linear mixed model.@*Results@#Totally 100 patients with hyperthyroidism were enrolled, including 24 men and 76 women and with a mean age of (38.5±14.0) years. The generalized linear mixed model was statistically significant (F=6 610.165, P<0.001), and patients' thyroid weight, time post-injection and distance from patients' neck significantly affected the ambient dose equivalent rate (F=57.967, 15 988.574, 11 200.645, all P<0.001), and the ambient dose equivalent rate positively correlated with patients' thyroid weight and negatively correlated with time post-injection and distance from patients' neck.@*Conclusions@#The ambient dose equivalent rate is affected by patients' thyroid weight, time post-injection and distance from patients' neck among patients with hyperthyroidism undergoing 99mTcO4- SPECT of the thyroid. Delay in contact with patients or keeping distance from patients may be effective for radiation protection.

Efficacy of the photon-induced photoacoustic streaming combined with nano-silver solution on Enterococcus faecalis in root canals / 口腔医学

Objective@#o explore the antibacterial effect of combined use of photon-induced photoacoustic streaming (PIPS) and silver nanoparticles (AgNPs) on Enterococcus faecalis biofilm in root canals.@*Methods@#A total of 36 isolated teeth with single root canal were collected to establish an experimental root canal model of Enterococcus faecalis infection. Samples were randomly divided into six groups and 0.9% NaCl, 2% NaClO, 0.1% AgNPs solutions were used with conventional needle irrigation (CNI) or PIPS for root canals. Colony count method was used to measure the number of Enterococcus faecalis biofilm in root canals before and after treatment, and the percentage of colony count reduction was calculated.@*Results@#The inhibitory effect of Enterococcus faecalis biofilm in all experimental groups was stronger than that in the control group (P<0.05). The decrease amplitude of 0.9% NaCl, 2% NaClO, 0.1% AgNPs assisted with PIPS was greater than that of 0.9% NaCl, 2% NaClO, 0.1% AgNPs assisted with CNI (P<0.05). The decrease in the 0.1% AgNPs assisted with PIPS group was significantly greater than that in the 2% NaClO assisted with PIPS group (P<0.05).@*Conclusion@#PIPS-assisted AgNPs solution washing can significantly improve the effect of clearing Enterococcus faecalis biofilm in root canals.

Direction Selectivity of TmY Neurites in Drosophila / 神经科学通报·英文版

The perception of motion is an important function of vision. Neural wiring diagrams for extracting directional information have been obtained by connectome reconstruction. Direction selectivity in Drosophila is thought to originate in T4/T5 neurons through integrating inputs with different temporal filtering properties. Through genetic screening based on synaptic distribution, we isolated a new type of TmY neuron, termed TmY-ds, that form reciprocal synaptic connections with T4/T5 neurons. Its neurites responded to grating motion along the four cardinal directions and showed a variety of direction selectivity. Intriguingly, its direction selectivity originated from temporal filtering neurons rather than T4/T5. Genetic silencing and activation experiments showed that TmY-ds neurons are functionally upstream of T4/T5. Our results suggest that direction selectivity is generated in a tripartite circuit formed among these three neurons-temporal filtering, TmY-ds, and T4/T5 neurons, in which TmY-ds plays a role in the enhancement of direction selectivity in T4/T5 neurons.

A comprehensive review on photon-counting computed tomography: Principles, technical hurdles and analysis of clinical applications / 生物医学工程学杂志

In recent years, photon-counting computed tomography (PCD-CT) based on photon-counting detectors (PCDs) has become increasingly utilized in clinical practice. Compared with conventional CT, PCD-CT has the potential to achieve micron-level spatial resolution, lower radiation dose, negligible electronic noise, multi-energy imaging, and material identification, etc. This advancement facilitates the promotion of ultra-low dose scans in clinical scenarios, potentially detecting minimal and hidden lesions, thus significantly improving image quality. However, the current state of the art is limited and issues such as charge sharing, pulse pileup, K-escape and count rate drift remain unresolved. These issues could lead to a decrease in image resolution and energy resolution, while an increasing in image noise and ring artifact and so on. This article systematically reviewed the physical principles of PCD-CT, and outlined the structural differences between PCDs and energy integration detectors (EIDs), and the current challenges in the development of PCD-CT. In addition, the advantages and disadvantages of three detector materials were analysed. Then, the clinical benefits of PCD-CT were presented through the clinical application of PCD-CT in the three diseases with the highest mortality rate in China (cardiovascular disease, tumour and respiratory disease). The overall aim of the article is to comprehensively assist medical professionals in understanding the technological innovations and current technical limitations of PCD-CT, while highlighting the urgent problems that PCD-CT needs to address in the coming years.

Current status and prospect of preoperative assessment of heart disease risk in liver transplant recipients / 器官移植

With the changes of the disease spectrum of liver transplantation and organ allocation system, more and more patients complicated with cardiovascular complications have entered the waiting list for liver transplantation. However, surgical stress, severe infection and adverse reactions of immunosuppressive drugs will significantly increase the risk of postoperative cardiac complications and affect the short-and long-term survival of the recipients. Therefore, comprehensive evaluation of cardiac structure and function of the recipients before liver transplantation is of significance for improving clinical prognosis of the recipients. In this article, the main causes for the increased risk of heart disease during the perioperative period of liver transplantation, the time and methods of heart disease risk assessment for liver transplant recipients were reviewed, and existing assessment approaches for common heart diseases before liver transplantation were illustrated, aiming to provide reference for further reducing the incidence of heart complications after liver transplantation, improving the survival rates of grafts and recipients and enhancing clinical prognosis.

Progress in application of single-photon emission computed tomography/computed tomography (SPECT/CT) imaging in clinical practice / 中国辐射卫生

@#The combination of conventional single-photon emission computed tomography (SPECT) and computed tomography (CT) may display the morphological changes of lesions and distribution of imaging agents, which is effective to improve the imaging sensitivity and specificity of tumors and non-tumor diseases. SPECT/CT is feasible to analyze the anatomical structure and metabolic status through displaying multi-site lesions with single imaging, thereby improving differential diagnosis and diagnostic accuracy of diseases. In addition, the novel mixed SPECT/CT device shortens the duration of image acquisition and provides precise attenuation correction and fusion imaging, which provides a scientific basis for rational selection of treatment regimens in clinical practice. This review describes the advances in clinical application of SPECT/CT.

Parotid duct anastomosis with an epidural catheter as a stent and evaluation of postoperative gland function / 口腔疾病防治

Objective @#To investigate the feasibility of epidural catheters in parotid gland duct anastomosis and the function of the affected side gland after parotid gland duct anastomosis. @* Methods@# Thirteen patients who were treated in the Department of Oral and Maxillofacial Surgery of Xuzhou Central Hospital using an epidural catheter as the scaffold for parotid gland catheter anastomosis were enrolled from Jan. 2019 to June 2021. The swelling, salivary fistula and catheter patency in the parotid gland area were evaluated two weeks after the operation. 99mTcO4- single photon emission computed tomography (SPECT) was used for quantitative detection of salivary gland secretion function@*Results@# Thirteen patients had no swelling or salivary fistula in the parotid gland area of the affected side two weeks after the operation, and the catheter secretion was unobstructed. There was no significant difference in the uptake rate between the parotid gland on the affected side and the parotid gland on the healthy side (t = -0.859, P = 0.399), and there was no significant difference in the excretion rate between the parotid gland on the affected side and the parotid gland on the healthy side (t = 0.693, P = 0.495). The parotid gland excretion function of the affected side was excellent three months after the operation.@*Conclusion @#Parotid duct anastomosis with an epidural catheter as the stent has good feasibility, and parotid gland secretion function recovers well after the operation, which is worthy of clinical application.

Frontiers and development in live-cell super-resolution fluorescence microscopy / 生物医学工程学杂志

This paper reviews the research progress on live-cell super-resolution fluorescence microscopy, discusses the current research status and hotspots in this field, and summarizes the technological application of super-resolution fluorescence microscopy for live-cell imaging. To date, this field has gained progress in numerous aspects. Specifically, the structured illumination microscopy, stimulated emission depletion microscopy, and the recently introduced minimal photon fluxes microscopy are the current research hotspots. According to the current progress in this field, future development trend is likely to be largely driven by artificial intelligence as well as advances in fluorescent probes and relevant labelling methods.

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)