This study provides a comprehensive review of single-photon emission computed tomography/computed tomography (SPECT/CT) imaging, encompassing its fundamental principles, clinical applications, contemporary research, and future prospects for clinical translation. The section on foundational theory discusses the underlying physical mechanisms, the use of radiopharmaceuticals, and the technological evolution of imaging systems. Clinical applications are thoroughly examined across the three primary domains: cardiovascular, neurological, and oncological pathologies. Despite considerable advancements, persistent challenges remain in optimizing radiation doses, improving diagnostic accuracy, and achieving cost-effective implementation. Additionally, this review highlights the emerging potential of novel radiotracers for SPECT/CT imaging and explores its transformative role in radioligand-based theranostics and personalized medicine. By synthesizing current research, this review aims to serve as a comprehensive reference to guide future technological innovations and clinical applications of SPECT/CT imaging.

Viral pathogens pose a persistent and devastating threat to global health, as starkly demonstrated by recent pandemics. The cornerstone of an effective response is rapid and reliable viral detection. Yet, conventional methods like viral culture, immunoassays, and nucleic acid amplification tests are hampered by limitations in speed, cost, sensitivity, and portability. Aptamers, single-stranded DNA or RNA oligonucleotides selected in vitro, have emerged as powerful molecular recognition elements that rival antibody affinity while offering superior thermal stability, manufacturability, and design flexibility. These attributes make them ideal for integration into next-generation biosensors. This review systematically summarizes recent advancements in aptamer-based biosensors for viral detection. It provides a comprehensive analysis of key methodologies for selecting virus-specific aptamers and a detailed examination of the various signal transduction mechanisms employed, including electrochemical, fluorescent, colorimetric, Surface Plasmon Resonance (SPR), and Surface-Enhanced Raman Scattering (SERS) biosensors. By critically evaluating the integration of high-affinity aptamers with diverse biosensing architectures, this work aims to establish a clear framework for understanding current progress and future directions. The review underscores the potential of these biosensors to deliver the rapid, sensitive, and field-deployable devices urgently needed for pandemic preparedness and effective viral outbreak management.

We report the synthesis and biological evaluation of 131I‐labeled antihuman tumor‐derived immunoglobulin G (IgG) light chain monoclonal antibody (4E9) ([131I]I‐4E9) as a promising probe for tumor imaging. [131I]I‐4E9 was synthesized in radiochemical yield of 89.9 ± 4.7% with radiochemical purity of more than 99%. [131I]I‐4E9 showed high stability in normal saline and human serum. In cell uptake studies, [131I]I‐4E9 exhibited favorable binding affinity and high specificity in HeLa MR cells. In biodistribution studies, [131I]I‐4E9 showed high tumor uptake, high tumor/non‐tumor ratios, and specific binding in BALB/c nu/nu mice bearing human HeLa MR xenografts. Single‐photon emission computerized tomography (SPECT) imaging of [131I]I‐4E9 in the HeLa MR xenograft model demonstrated clear visualization of tumor after 48 h and confirmed specific binding in tumor. These findings suggest that [131I]I‐4E9 possesses favorable biological characteristics and warrants further investigation as a prospective probe for imaging and treatment of cancers.

Purpose To explore valuable predictors for mediastinal lymph node metastasis in non-small cell lung cancer (NSCLC) patients, we analyzed the potential roles of standardized uptake value (SUV)-derived parameters from preoperative 18 F-FDG PET/CT combined with clinical characteristics. Methods Data from 224 NSCLC patients who underwent preoperative 18 F-FDG PET/CT scans in our hospital were collected. Then, a series of clinical parameters including SUV-derived features [SUVmax of mediastinal lymph node and primary-tumor SUVmax, SUVpeak, SUVmean, metabolic tumor volume (MTV) and total lesion glycolysis (TLG)] were evaluated. The best possible cutoff points for all measuring parameters were calculated using receiver operating characteristic curve (ROC) analysis. Predictive analyses were performed using a Logistic regression model to determine the predictive factors for mediastinal lymph node metastasis in NSCLC and lung adenocarcinoma patients. After multivariate model construction, data of another 100 NSCLC patients were recorded. Then, 224 patients and 100 patients were enrolled to validate the predictive model by the area under the receiver operating characteristic curve (AUC). Results The mediastinal lymph node metastasis rates in 224 patients for model construction and 100 patients for model validation were 24.1% (54/224) and 25% (25/100), respectively. It was found that SUVmax of mediastinal lymph node ≥ 2.49, primary-tumor SUVmax ≥ 4.11, primary-tumor SUVpeak ≥ 2.92, primary-tumor SUVmean ≥ 2.39, primary-tumor MTV ≥ 30.88 cm 3 , and primary-tumor TLG ≥ 83.53 were more prone to mediastinal lymph node metastasis through univariate logistic regression analyses. The multivariate logistic regression analyses showed that the SUVmax of mediastinal lymph nodes (≥ 2.49: OR 7.215, 95% CI 3.326–15.649), primary-tumor SUVpeak (≥ 2.92: OR 5.717, 95% CI 2.094–15.605), CEA (≥ 3.94 ng/ml: OR 2.467, 95% CI 1.182–5.149), and SCC (< 1.15 ng/ml: OR 4.795, 95% CI 2.019–11.388) were independent predictive factors for lymph node metastasis in the mediastinum. It was found that SUVmax of the mediastinal lymph node (≥ 2.49: OR 8.067, 95% CI 3.193–20.383), primary-tumor SUVpeak (≥ 2.92: OR 9.219, 95% CI 3.096–27.452), and CA19-9 (≥ 16.6 U/ml: OR 3.750, 95% CI 1.485–9.470) were significant predictive factors for mediastinal lymph node metastasis in lung adenocarcinoma patients. The AUCs for the predictive value of the NSCLC multivariate model through internal and external validation were 0.833 (95% CI 0.769- 0.896) and 0.811 (95% CI 0.712–0.911), respectively. Conclusion High SUV-derived parameters (SUVmax of mediastinal lymph node and primary-tumor SUVmax, SUVpeak, SUVmean, MTV and TLG) might provide varying degrees of predictive value for mediastinal lymph node metastasis in NSCLC patients. In particular, the SUVmax of mediastinal lymph nodes and primary-tumor SUVpeak could be independently and significantly associated with mediastinal lymph node metastasis in NSCLC and lung adenocarcinoma patients. Internal and external validation confirmed that the pretherapeutic SUVmax of the mediastinal lymph node and primary-tumor SUVpeak combined with serum CEA and SCC can effectively predict mediastinal lymph node metastasis of NSCLC patients.

Breast cancer is a high incidence and mortality cancer with high heterogeneity. Early accurate diagnosis and individualized treatment are effective means to improve the survival rate of patients. Molecular nuclear medicine imaging combines molecular biology technology with nuclear medicine, qualitative and quantitative studying the biological behavior of cancer in molecules, cells and living levels. It is a highly repeatable, safe and non-invasive imaging, which is widely used in the diagnosis, staging, prognosis prediction and efficacy evaluation of various malignant tumors. This article reviewed the molecular nuclear medicine of breast cancer, including metabolic, receptor, gene and immunoPET imaging.

目的 分析18F-FDG PET/CT动态观察单纯125I粒子植入术及联合化学治疗(化疗)对兔VX2肺癌的干预效果的价值.方法 将VX2肿瘤组织接种于3～4月龄新西兰大耳白兔右肺下叶,制成兔VX2肺癌模型.将30只模型兔随机分为3组,每组10只.对A组通过治疗计划系统(TPS)植入25.9 MBq(0.7 mCi)125I粒子,B组经耳缘静脉注射顺铂7 mg/kg体质量,C组予以上2种干预.分别于治疗前及治疗后第3、7、14天对实验兔行全身PET/CT扫描,于右肺肿瘤部位及肝右叶勾画ROI,检测其最大标准摄取值(SUVmax),计算肿瘤SUVmax/肝脏SUVmax(SUVT/L);于治疗前及治疗后第3、7天完成PET/CT检查后分别处死2只,治疗后第14天PET/CT检查后处死4只动物,取肿瘤组织进行病理学检查.结果 3组间及A、B组内治疗前及治疗后不同时间点肿瘤最大径差异均无统计学意义(P均>0.05).C组治疗后第14天肿瘤最大径较治疗前缩小(P<0.05).治疗后第7、14天,C组SUVT/L值较A、B组均降低(P均<0.05);A、B组治疗后第7、14天SUVT/L值均较治疗前降低,C组治疗后第3、7、14天SUVT/L值均较治疗前降低(P均<0.05).病理学检查发现3组治疗后肿瘤细胞均逐渐减少,A、C组炎症细胞及肿瘤坏死区较B组更多;C组治疗后第14天仅见少量肿瘤细胞,炎症细胞及纤维组织增多.结论 18F-FDG PET/CT可动态监测并早期评价单纯125 I粒子植入术及联合化疗对兔VX2肺癌的干预效果.

Bone metastasis has a significant influence on the prognosis of prostate cancer(PCa) patients. In this review, we discussed the current application of PCa bone metastasis diagnosis with single-photon emission computed tomography (SPECT) and positron emission tomography/computed tomography (PET/CT) computer-aided diagnosis(CAD) systems. A literature search identified articles concentrated on PCa bone metastasis and PET/CT or SPECT CAD systems using the PubMed database. We summarized the previous studies focused on CAD systems and manual quantitative markers calculation, and the coincidence rate was acceptable. We also analyzed the quantification methods, advantages, and disadvantages of CAD systems. CAD systems can detect abnormal lesions of PCa patients’ 99mTc-MDP-SPECT, 18F-FDG-PET/CT, 18F-NaF-PET/CT, and 68 Ga-PSMA PET/CT images automated or semi-automated. CAD systems can also calculate the quantitative markers, which can quantify PCa patients’ whole-body bone metastasis tumor burden accurately and quickly and give a standardized and objective result. SPECT and PET/CT CAD systems are potential tools to monitor and quantify bone metastasis lesions of PCa patients simply and accurately, the future clinical application of CAD systems in diagnosing PCa bone metastasis lesions is necessary and feasible.

Chemotherapy is an important method for the treatment of lung cancer, but multidrug resistance (MDR) greatly reduces the efficacy. The superfamily of ATP-binding cassette (ABC) transport proteins is related to MDR. As a subfamily of ABC proteins, ABCG2/BCRP (breast cancer resistance protein, BCRP) is considered a major player in the development of cancer MDR. For the stratification of chemotherapeutic choices, we constructed Cy5.5- or 89Zr-labeled ABCG2-targeted monoclonal antibody (mAb) ABCG2-PKU1 for noninvasive evaluation of ABCG2 expression in lung cancer xenograft models. ABCG2 expression was screened in H460/MX (mitoxantrone resistant), H460, and H1299 human lung cancer cell lines using Western blotting. ELISA, flow cytometry, and cell immunofluorescent staining were used to evaluate the binding ability of ABCG2-PKU1 to ABCG2 antigen. Lung cancer murine xenograft models were built for in vivo experiments. ABCG2-PKU1 was labeled with Cy5.5 (Cy5.5-ABCG2) for fluorescent imaging and radiolabeled with 89Zr (89Zr-DFO-ABCG2) for immunoPET imaging following the conjugation with p-SCN-deferoxamine (DFO). In vivo imaging was performed in lung cancer models at 2, 24, 48, 72, 96, 120, 144, and 168 h postinjection. Ex vivo biodistribution was conducted after the terminal time point of imaging. Finally, tissue immunohistochemical staining was used to evaluate the tumor expression of ABCG2. Western blotting showed that the H460/MX cells had a high ABCG2 expression level whereas H460 and H1299 had moderate and low levels. ELISA, flow cytometry, and cell immunofluorescent staining results validated the good binding affinity between ABCG2-PKU1 and ABCG2. The H460/MX and H460 cells were used to build positive lung cancer models, and H1299 cells were used to build negative models. The fluorescent imaging showed that the tumor average radiant efficiency of Cy5.5-ABCG2 reached the maximum at 72 and 120 h in H460/MX and H460 respectively (n = 3, P < 0.01). The tumor uptake of Cy5.5-ABCG2 in H1299 (n = 3) was significantly lower than H460/MX and H460 (P < 0.01). ImmunoPET imaging showed that the tumor uptake of 89Zr-DFO-ABCG2 in H460/MX was significantly higher than H460, with a maximum of 4.15 ± 0.41 %ID/g and 2.81 ± 0.24 %ID/g at 168 and 144 h, respectively (n = 5, P < 0.01). The H1299 tumors showed significantly lower uptake than H460/MX and H460 (n = 5, P < 0.01). The radioactive uptake of 89Zr-DFO-ABCG2 among three groups in the heart, liver, and kidney gradually decreased over time. Ex vivo biodistribution verified the differential tumor uptake among the three groups (P < 0.01). Immunohistochemical staining revealed that the H460/MX tumor had the highest expression of ABCG2, whereas H460 and H1299 had the moderate and lowest expression, respectively. Therefore, in this study, fluorescent and immunoPET imaging of lung cancer MDR models using Cy5.5-ABCG2 and 89Zr-DFO-ABCG2 noninvasively evaluated the differential expression of ABCG2, which are expected to be used for the diagnosis and the selection for clinical treatment options for lung cancer MDR patients in future applications.

Mesoporous carbon nanotubes (mCNTs) hold great promise interests, owing to their superior nano-platform properties for biomedicine. To fully utilize this potential, the toxicity and biodistribution of pristine and surface-modified mCNTs (-OH/-COOH) should preferentially be addressed. The results of cell viability suggested that pristine mCNTs induced cell death in a concentration-dependent manner. As evidence of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD), pristine mCNTs induced noticeable redox imbalance. 99mTc tracing data suggested that the cellular uptake of pristine mCNTs posed a concentrate-dependent and energy-dependent manner via macropinocytotic and clathrin-dependent pathways, and the main accumulated organs were lung, liver and spleen. With OH modification, the ROS generation, MDA deposition and SOD consumption were evidently reduced compared with the pristine mCNTs at 24/48 h high-dose exposure. With COOH modification, the modified mCNTs only showed a significant difference in SOD consumption at 24/48 h exposure, but there was no significant difference in the measurement of ROS and MDA. The internalization mechanism and organ distribution of modified mCNTs were basically invariant. Together, our study provides evidence that mCNTs and the modified mCNTs all could induce oxidative damage and thereby impair cells. 99mTc-mCNTs can effectively trace the distribution of nanotubes in vivo.

Objective T cell lymphomas are associated with an aggressive worse prognosis. This study is designed to assess T cell lymphomas using F-18-FDG PET/CT. Methods Sixty-four patients with newly diagnosed T cell lymphomas underwent PET/computed tomography (PET/CT) scans, 47 cases who were fully followed up were retrospectively reviewed and analyzed. Overall survival (OS) and progression-free survival (PFS) were recorded for prognosis. We measured the maximum standardized uptake value (SUVmax) in all cases, analyzed the correlation between SUVmax and survival and other clinicopathologic parameters. Kaplan-Meier log-rank tests were then used to compare the survival of high and low PET/CT parameter groups, and multivariate Cox proportional hazards regression analysis was carried out to identify predictors of OS and PFS. Results With a median follow-up of 26.5 (range 0.7-117.5) months, the 1-, 2- and 3-year OS were 75.6, 61.7 and 49.2%, and PFS were 49.3, 39.9 and 29.9%, respectively in 47 patients. Among them, 33 cases progressed with a median time of 9.5 (0.7-115.0) months, and 26 patients died with a median survival time of 26.5 (0.7-117.5) months. Multivariate analysis showed the following independent prognostic factors for OS: age >60 years (P = 0.002), SUVmax >9.7 (P = 0.009) and extranodal involvement of more than one site (P = 0.018). In addition, lactate dehydrogenase level (P = 0.003) and B symptoms (P = 0.018) were independent risk factors for PFS. Conclusion Pretherapy SUVmax may serve as an independent predictor of outcome in patients with newly diagnosed T cell lymphomas.

Multiple myeloma (MM) is a malignant tumor of the blood system that is more common in the elderly with abnormal proliferation of bone marrow plasma cells. The current diagnostic methods mainly rely on the detection of M protein and invasive bone marrow aspiration biopsy. The sensitivity and specificity of conventional imaging tests are low. Molecular imaging technology provides new options and methods for the noninvasive diagnosis of MM. Whole-body MRI (WB-MRI) has good soft tissue contrast and spatial resolution, which can show bone marrow infiltration and vascular conditions. Metabolic imaging such as 18F-FDG, acetate, choline, and methionine are highly sensitive. ImmunoPET imaging screens specific targets for targeted therapy or immunotherapy and evaluates the efficacy. This article reviews the progress of molecular imaging in MM, especially immunoPET imaging.

Pep-1 (CGEMGWVRC) can potently bind to interleukin 13 receptor α 2 (IL-13Rα2), a tumor-restricted receptor found to be expressed in various malignancies. In this study, we intended to prepare a 99mTc-labeled probe and evaluate its in vivo tumor accumulation properties in a cervical cancer xenograft model. The Pep-1 was designed and radiolabeled with 99mTc by conjugation with mercaptoacetyl-triglycine (MAG3). The labeling yield, radiochemical purity and stability were characterized in vitro. Cell uptake assays and fluorescence imaging were conducted for qualitative and quantitative evaluation of the specificity and affinity of Pep-1. Flow cytometry and tissue immunofluorescence were used to confirm the IL-13Rα2 expression in cervical cancer. Biodistribution and in vivo imaging were performed periodically to evaluate the imaging value of 99mTc-MAG3-Pep-1 in cervical cancer xenograft model. 99mTc-MAG3-Pep-1 was successfully prepared with a high labeling yield and radiochemical purity (> 95%). Specific cell uptake was demonstrated by scramble control and unlabeled MAG3-Pep-1 blockade. Flow cytometry and tissue immunofluorescence also confirmed the mild IL-13Rα2 expression of HeLa. In the gamma imaging study and biodistribution, the tumors were imaged clearly at 2–6 h after injection of 99mTc-MAG3-Pep-1 and the accumulation of 99mTc-MAG3-Pep-1 in tumor was significantly higher than that in the blocking and scramble controls, demonstrating ligand–receptor binding specificity. This work demonstrated that 99mTc-MAG3-Pep-1 can bind to cervical cancer with high affinity and specificity. MAG3-Pep-1 may be a prospective precursor for IL-13Rα2-expressing cancer therapy.

18F-FDG uptake rate constant Ki is the main physiology parameter measured in dynamic PET studies. A model-independent graphical analysis using Patlak plot with plasma input function (PIF) is a standard approach used to estimate Ki . The PIF is the 18F-FDG time activity curve (TAC) in plasma that is obtained by serial arterial blood sampling. The purpose of the study is to evaluate a Patlak plot-based optimization approach with reduced blood samples for noninvasive quantification of dynamic 18F-FDG PET imaging. Eight 60 min rhesus monkey brain dynamic 18F-FDG PET scans with arterial blood samples were collected. The measured PIF (mPIF) was determined by arterial blood samples. TACs of seven cerebral regions of interest were generated from each study. With a given number of blood samples, the population-based PIF (pPIF) was determined by either interpolation or extrapolation method using scale calibrated population mean of normalized PIF. The optimal sampling scheme with given blood sample size was determined by maximizing the correlations between the Ki estimated from pPIF and those obtained by mPIF. A leave-two-out cross-validation method was used for evaluation. The linear correlations between the Ki estimates from pPIF with optimal sampling schemes and those from mPIF were: Ki (pPIF 1 sample at 40 min) = 1.015 Ki (mPIF) − 0.000, R 2 = 0.974; Ki (pPIF 2 samples at 35 and 50 min) = 1.052 Ki (mPIF) − 0.001, R 2 = 0.976; Ki (pPIF 3 samples at 12, 40, and 50 min) = 1.030 Ki (mPIF) − 0.000, R 2 = 0.985; and Ki (pPIF 4 samples at 10, 20, 40, and 50 min) = 1.016 Ki (mPIF)- 0.000, R 2 = 0.993. As the sample size became greater or equal to 4, the Ki estimates from pPIF with the optimal protocol were almost identical to those from mPIF. The Patlak plot-based optimization approach is a reliable method to estimate PIF for noninvasive quantification of non-human primate dynamic 18F-FDG PET imaging and is potentially extendable to further translational human studies.

目的 对131I-c(RGD)2在原位荷脑胶质瘤动物模型中的靶向定位作用进行研究,以探讨其应用于脑胶质瘤诊断与治疗的可能性.方法 采用U87-MG人脑胶质瘤细胞接种在裸鼠右脑尾状核内,建立了原位荷脑胶质瘤动物模型;采用氯氨T法将131I标记c(RGD)2,于原位荷脑胶质瘤裸鼠中进行生物分布研究,计算131I-c(RGD)2在脑胶质瘤中的摄取率及肿瘤与正常脑组织摄取率的比值(T/NT).结果 给药后3 h及6 h,肾的摄取均为所有器官中最高;给药后3 h肿瘤未累及的脑组织的摄取率为(0.16±0.10)％ID/g,胶质瘤组织的摄取率为(0.41±0.26)％ID/g,脑胶质瘤中的摄取率显著高于正常脑组织摄取率(P值为0.025);给药后6 h肿瘤未累及的脑组织的摄取率为(0.08±0.04)％ID/g,胶质瘤组织的摄取率为(0.44±0.23)％ID/g,脑胶质瘤中的摄取率亦显著高于正常脑组织摄取率(P值为0.011);给药后3 h T/NT比值为3.36±1.86,给药后6 h T/NT比值增高至5.55±1.75.结论 c(RGD)2具有靶向颅内胶质瘤的能力,在胶质瘤的靶向诊断与治疗中具有潜力,但其在脑胶质瘤中的摄取率相对较低,有待于进一步提高.

合成了一种可特异性结合纤维蛋白-纤维连接蛋白的早期血栓显像剂131 I-YSSCREKA肽(酪氨酸-(D)丝氨酸-(D)丝氨酸-半胱氨酸-精氨酸-谷氨酸-赖氨酸-丙氨酸),对其标记、SPECT显像及初步生物学性能进行研究.结果表明:YSSCREKA八肽在室温下通过氯胺-T法反应5 min的标记率为(77.2±1.1)％(n=3),放射化学纯度为(90.0±3.1)％(n=3),体外稳定性较好.新西兰家兔SPECT显像显示在131 I-YSSCREKA肽注射后20 h血栓能较清晰地显像,血栓/血放射性比值为1.36.SD大鼠生物分布实验显示:20 h 131 I-YSSCREKA肽在血栓中的摄取率为(0.19±0.06)ID％/g(n=5),血栓/肌肉及血栓/血放射性比值分别为3.80和1.90.131 I-YSSCREKA肽有可能作为早期血栓的显像剂,但其在血栓中的摄取率有待于进一步提高.

放射性药物是核科学技术在医学应用上的重要基石之一.我国放射性药物临床转化应用研究较国外发展较为滞后,且自身存在一定问题,研发具有我国自主知识产权并具有临床应用前景的新型放射性药物势在必行.本文回顾了我国放射性药物的应用现状,通过横向比较和纵向分析我国放射性药物发展的潜在共性问题,结合当前小分子多肽放射性药物应用研究呈不同程度持续推进的临床转化工作,针对存在问题深层次剖析,并提出了研发具有应用前景和临床转化的新型诊治放射性药物的重要性和必要性.

新型冠状病毒肺炎已在全世界多个国家暴发,如何提升早期筛查率成为疫情防控的重点.计算机断层扫描(CT)在中国新冠肺炎的早期筛查及疾病监测中发挥了重要作用,因此,提升广大影像医生对肺炎诊断的准确性尤其重要.本文旨在述评CT在新冠肺炎筛查中的应用价值、诊断及鉴别诊断要点,比较新冠肺炎与其他病毒性肺炎、细菌性肺炎等的CT表现差别,以期在今后的疫情防控中CT可以发挥更好的作用,帮助即早发现并隔离病患.