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Extracellular vesicles (EVs), nanosized lipid bilayer vesicles released by nearly all types of cells, play pivotal roles as intercellular signaling mediators with diverse biological activities. Their adaptability has attracted interest in exploring their role as disease biomarker theranostics. However, the in vivo biodistribution and pharmacokinetic profiles of EVs, particularly following administration into living subjects, remain unclear. Thus, in vivo imaging is vital to enhance our understanding of the homing and retention patterns, blood and tissue half-life, and excretion pathways of exogenous EVs, thereby advancing real-time monitoring within biological systems and their therapeutic applications. This review examines state-of-the-art methods including EV labeling with various agents, including optical imaging, magnetic resonance imaging, and nuclear imaging. The strengths and weaknesses of each technique are comprehensively explored, emphasizing their clinical translation. Despite the potential of EVs as cancer theranostics, achieving a thorough understanding of their in vivo behavior is challenging. This review highlights the urgency of addressing current questions in the biology and therapeutic applications of EVs. It underscores the need for continued research to unravel the complexities surrounding EVs and their potential clinical implications. By identifying these challenges, this review contributes to ongoing efforts to optimize EV imaging techniques for clinical use. Ultimately, bridging the gap between research advancements and clinical applications will facilitate the integration of EV-based theranostics, marking a crucial step toward harnessing the full potential of EVs in medical practice.

Purpose: While immunotherapy has revolutionized the oncology field, variations in therapy responsiveness limit the broad applicability of these therapies. Diagnostic imaging of immune cell, and specifically CD8+ T cell, dynamics could allow early patient stratification and result in improved therapy efficacy and safety. In this study, we report the development of a nanobody-based immunotracer for non-invasive SPECT and PET imaging of human CD8+ T-cell dynamics. Methods: Nanobodies targeting human CD8β were generated by llama immunizations and subsequent biopanning. The lead anti-human CD8β nanobody was characterized on binding, specificity, stability and toxicity. The lead nanobody was labeled with technetium-99m, gallium-68 and copper-64 for non-invasive imaging of human T-cell lymphomas and CD8+ T cells in human CD8 transgenic mice and non-human primates by SPECT/CT or PET/CT. Repeated imaging of CD8+ T cells in MC38 tumor-bearing mice allowed visualization of CD8+ T-cell dynamics. Results: The nanobody-based immunotracer showed high affinity and specific binding to human CD8 without unwanted immune activation. CD8+ T cells were non-invasively visualized by SPECT and PET imaging in naïve and tumor-bearing mice and in naïve non-human primates with high sensitivity. The nanobody-based immunotracer showed enhanced specificity for CD8+ T cells and/or faster in vivo pharmacokinetics compared to previous human CD8-targeting immunotracers, allowing us to follow human CD8+ T-cell dynamics already at early timepoints. Conclusion: This study describes the development of a more specific human CD8+ T-cell-targeting immunotracer, allowing follow-up of immunotherapy responses by non-invasive imaging of human CD8+ T-cell dynamics. [ABSTRACT FROM AUTHOR]

Aim: Tumor markers often remain elevated after intended curative resection of medullary thyroid carcinoma (MTC). The aim of this study was to determine the expression of αvβ3, a promising theranostics target, in MTC and its metastases. Materials & methods: Avβ3 expression was analyzed in 104 patients using a tissue microarray and correlated with clinicopathological variables and survival. Results: Cytoplasmic αvβ3 positivity was seen in 70 patients and was associated with lymph node metastases at time of initial surgery. Membranous positivity was considered positive in 30 patients and was associated with sporadic MTC. Conclusion: Avβ3 was expressed in the cytoplasm of 67% of MTC patients. Membranous expression, which is presumably most relevant for the theranostic use of αvβ3, was seen in 29%. Article highlights After intended curative resection of medullary thyroid carcinoma (MTC), calcitonin levels often remain elevated indicating remnant disease or metastasis. There is a demand for new imaging and therapeutic options for patients with MTC. Avβ3, an integrin expressed in many tumors, is a promising target for nuclear imaging and treatment using radiolabeled arginine-glycine-aspartic acid (RGD). Cytoplasmic and membranous αvβ3 expression was analyzed using a tissue microarray including primary tumors and lymph node metastases of 104 and 27 patients, respectively. Cytoplasmic expression was considered positive in 67% of patients and was associated with lymph node metastases at the time of initial surgery. Membranous expression, which is thought to be most relevant for the theranostic use of αvβ, was seen in 29% of patients and was associated with sporadic MTC. Survival analysis showed no prognostic value of αvβ3. The correlation of immunohistochemical αvβ3 expression and uptake of radiolabeled RGD should be further assessed in patients with membranous αvβ3 expression. [ABSTRACT FROM AUTHOR]

Background Infective endocarditis (IE) is a serious and fatal condition, with prosthetic valve endocarditis representing the worst prognosis. The recommended nuclear imaging modality 2-deoxy-2-[18F]fluoro- D- glucose positron emission tomography/computed tomography ([18F]FDG PET/CT) has limitations. In this case series, we present two patients with IE scanned with a novel PET tracer [64Cu]Cu-DOTATATE ([64Cu]Cu-[1,4,7,10-tetraazacyclododecane- N , N ′, N ″, N ‴-tetra acetic acid]-d-Phe1, Tyr3-octreotate). Case summary An 84-year-old female patient (Patient 1) with a biological mitral valve prosthesis (MVP) was admitted acutely from the outpatient clinic. Transoesophageal echocardiography showed vegetations on the MVP. The patient underwent [64Cu]Cu-DOTATATE PET/CT, which showed uptake at the site of infection. The patient underwent surgical valve replacement. The post-operative period was without significant complications, and the patient was discharged home. In another case, a 72-year-old male patient (Patient 2) with a medical history of mild mitral valve stenosis, aortic valve stenosis, and gastrointestinal stromal tumour was admitted to the hospital for back and abdominal pain and subfebrile episodes. Transoesophageal echocardiography showed large vegetations in the native aortic valve. The patient underwent [64Cu]Cu-DOTATATE PET/CT, which showed no uptake at the site of the suspected infection. The patient underwent surgical valve replacement. The post-operative period was characterized by Candida albicans sternitis, and after prolonged hospitalization, the patient died of respiratory failure as a complication of sepsis. Discussion In conclusion, this is the first case series presenting two patients with definite IE (modified Duke criteria), who were scanned with the novel [64Cu]Cu-DOTATATE PET/CT. Patient 1, with endocarditis in the MVP, showed an uptake of the tracer, while Patient 2, with native aortic valve endocarditis, did not show any uptake. [ABSTRACT FROM AUTHOR]

In recent years, the application of radionuclides‐containing nanomaterials in cancer treatment has garnered widespread attention. The diversity of nanomaterials allows researchers to selectively combine them with appropriate radionuclides for biomedical purposes, addressing challenges faced by peptides, small molecules, or antibodies used for radionuclide labeling. However, with advantages come challenges, and nanoradionuclides still encounter significant issues during clinical translation. This review summarized the recent progress of nanosized radionuclides for cancer treatment or diagnosis. The discussion began with representative radionuclides and the methods of incorporating them into nanomaterial structures. Subsequently, new combinations of nanomaterials and radionuclides, along with their applications, were introduced to demonstrate their future trends. The benefits of nanoradionuclides included optimized pharmacokinetic properties, enhanced disease‐targeting efficacy, and synergistic application with other treatment techniques. Besides, the basic rule of this section was to summarize how these nanoradionuclides can truly impact the diagnosis and therapy of various cancer types. In the last part, the focus was devoted to the nanoradionuclides currently applicable in clinics and how to address the existing issues and problems based on our knowledge. [ABSTRACT FROM AUTHOR]

Labeling and tracking existing and emerging cell-based immunotherapies using nuclear imaging is widely used to guide the preclinical phases of development and testing of existing and new emerging off-the-shelf cell-based immunotherapies. In fact, advancing our knowledge about their mechanism of action and limitations could provide preclinical support and justification for moving towards clinical experimentation of newly generated products and expedite their approval by the Food and Drug Administration (FDA). Here we provide the reader with a ready to use protocol describing the labeling methodologies and practical procedures to render different candidate cell therapies in vivo traceable by nuclear-based imaging. The protocol includes sufficient practical details to aid researchers at all career stages and from different fields in familiarizing with the described concepts and incorporating them into their work. [ABSTRACT FROM AUTHOR]

Endocarditis, a serious infectious disease, remains a diagnostic challenge in contemporary clinical practice. The advent of advanced imaging modalities has contributed significantly to the improved understanding and management of this complex disease. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) imaging has shown remarkable potential in improving the diagnostic accuracy of endocarditis. In the update of the Modified Duke Criteria, in 2023, The International Society for Cardiovascular Infectious Diseases (ISCVID) Working Group recognized specific 18F-FDG PET/CT findings as a major diagnostic criterion, particularly in patient with prosthetic valve endocarditis. The ability of PET to visualize metabolic activity allows for the identification of infective foci and could differentiate between infective and non-infective processes. This review examines the clinical utility of PET in differentiating infective endocarditis from other cardiovascular pathologies, highlighting its sensitivity and specificity in detecting native and prosthetic valve infections, including patients with transcatheter aortic valve implantation (TAVI), cardiac implantable devices (CIEDs), and left ventricular assistance devices (LVAD). Also, practical aspects and indications are illustrated to optimize the quality of imaging and reduce potential false positive results. In conclusion, the current use of PET in endocarditis has become a valuable diagnostic tool; as technological advances continue, PET will play an increasingly important role in the multidisciplinary approach to the management of endocarditis. [ABSTRACT FROM AUTHOR]

Bradykinin B1 receptor (B1R) has garnered attention as a cancer therapeutic and diagnostic target. Several reports on radiolabelled derivatives of B1R antagonists have shown favourable properties as imaging agents in cells highly expressing hB1R following transfection. In the present study, we assessed whether radiolabelled probes can detect B1R endogenously expressed in cancer cells. To this end, we evaluated 111In-labelled derivatives of a B1R antagonist ([111In]In-DOTA-Ahx-R954) using glioblastoma cell lines (U87MG and U251MG) with different B1R expression levels. Cellular uptake studies showed that the specific accumulation of [111In]In-DOTA-Ahx-R954 in U87MG was higher than that in U251MG, which correlated with B1R expression levels. Tissue distribution in U87MG-bearing mice revealed approximately 2-fold higher radioactivity in tumours than in the muscle in the contralateral leg. The specific accumulation of [111In]In-DOTA-Ahx-R954 in the tumour was demonstrated by the reduction in the tumour-to-plasma ratios in nonlabelled R954-treated mice. Moreover, ex vivo autoradiographic images revealed that the intratumoural distribution of [111In]In-DOTA-Ahx-R954 correlated with the localisation of B1R-expressing glioblastoma cells. In conclusion, we demonstrated that [111In]In-DOTA-Ahx-R954 radioactivity correlated with B1R expression in glioblastoma cells, indicating that radiolabelled derivatives of the B1R antagonist could serve as promising tools for elucidating the involvement of B1R in cancer. [ABSTRACT FROM AUTHOR]

Purpose: This systematic review aims to investigate the role of nuclear imaging techniques in detecting incidentalomas and their impact on patient management. Methods: Following PRISMA guidelines, a comprehensive literature search was conducted from February to May 2022. Studies in English involving patients undergoing nuclear medicine studies with incidental tumor findings were included. Data on imaging modalities, incidentaloma characteristics, management changes, and follow-up were extracted and analyzed. Results: Ninety-two studies involving 64.884 patients were included. Incidentalomas were detected in 611 cases (0.9%), with thyroid being the most common site. PET/CT with FDG and choline tracers showed the highest incidentaloma detection rates. Detection of incidentalomas led to a change in therapeutic strategy in 59% of cases. Various radiotracers demonstrated high sensitivity for incidentaloma detection, particularly in neuroendocrine tumors and prostate cancer. Conclusion: Nuclear imaging techniques play a crucial role in detecting incidentalomas, leading to significant changes in patient management. The high sensitivity of these modalities highlights their potential in routine oncology follow-up protocols. Future directions may include enhancing spatial resolution and promoting theranostic approaches for improved patient care. [ABSTRACT FROM AUTHOR]

Purpose of Review: There has been increasing use of multimodality imaging in the evaluation of cardiomyopathies. Recent Findings: Echocardiography, cardiac magnetic resonance (CMR), cardiac nuclear imaging, and cardiac computed tomography (CCT) play an important role in the diagnosis, risk stratification, and management of patients with cardiomyopathies. Summary: Echocardiography is essential in the initial assessment of suspected cardiomyopathy, but a multimodality approach can improve diagnostics and management. CMR allows for accurate measurement of volumes and function, and can easily detect unique pathologic structures. In addition, contrast imaging and parametric mapping enable the characterization of tissue features such as scar, edema, infiltration, and deposition. In non-ischemic cardiomyopathies, metabolic and molecular nuclear imaging is used to diagnose rare but life-threatening conditions such amyloidosis and sarcoidosis. There is an expanding use of CCT for planning electrophysiology procedures such as cardioversion, ablations, and device placement. Furthermore, CCT can evaluate for complications associated with advanced heart failure therapies such as cardiac transplant and mechanical support devices. Innovations in multimodality cardiac imaging should lead to increased volumes and better outcomes. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to highlight presentations, acute findings and imaging phenotypes of patients presenting to the emergency department (ED) within 30 days of a transcatheter aortic valve replacement (TAVR). Methods: A retrospective review of patients diagnosed with aortic valve disease who underwent a TAVR between Jan 2015 and Nov 2021 at a large academic medical center was completed. From an initial 1271 patients, 146 were included based on their presentation to the ED within 30 days post-TAVR procedure. Patient data, including ED presentation details and imaging results, were recorded and de-identified. Results: Of the 146 post-TAVR patients, there were 168 ED visits within 30 days. The median time to ED after TAVR was 12 days. Respiratory symptoms were the most common complaint (27%). Neurological (23%) and cardiovascular symptoms (18%) followed. Cross-sectional imaging was conducted 250 times across visits, with an average of 1.7 scans per patient. CTs were most frequently used, followed by ultrasounds, especially echocardiograms and duplex extremity vasculature ultrasounds. 30.1% of patients had acute findings from imaging. Specific findings included heart failure (5.5%), access site complications (5.5%), pneumonia (5.5%), intracranial pathologies (3.4% for strokes and 0.7% for hematoma), and pleural effusion (3.4%). Echocardiograms and CTA chest were most associated with significant acute findings. Conclusion: Our study highlights the vital role of early and accurate imaging in post-TAVR patients within 30 days post-procedure. As transcatheter approaches rise in popularity, emergency radiologists become instrumental in diagnosing common post-procedural presentations. Continued research is essential to devise post-discharge strategies to curtail readmissions and related costs. Proper imaging ensures prompt, effective care, enhancing overall patient outcomes. [ABSTRACT FROM AUTHOR]

Leaves of soursop (Annona muricata) is a potential anti-cancer agent. However, there is no report on the effect of soursop leaf phytochemicals against osteosarcoma, a musculoskeletal cancer commonly affecting children and adults. The current study identified 28 metabolites from ethyl acetate leaf (EAL) extract through GC–MS chemoprofiling and subjected to in silico analysis against the potential protein target, platelet-derived growth factor receptor α (PDGFRA) of osteosarcoma, including absorption, distribution, metabolism, and excretion and toxicity (ADMET) analysis to identify the possible hit compounds. This resulted in three hit leaf bioactives, namely 2'-hydroxy-5'-methyl chalcone, linoleic acid and annonacin showing good binding affinity with a docking score of − 7.4, − 7.0 and − 6.9 kcal/mol, respectively. With ADMET analysis, 2'-hydroxy-5'-methyl chalcone and linoleic acid obeyed Lipinski's rule of five, whereas annonacin showed a slight violation. Among the three docked complexes, annonacin shows good stability during molecular dynamic simulation performed with PDGFRA. The concentration of the key marker compound, annonacin in EAL concentrate is found to be 5.032 ± 0.13 mg/g of leaf sample and is used for cytotoxicity assessment. Further, EAL concentrate exhibits cytotoxicity (IC50 value) on MG-63 osteosarcoma cells in vitro for concentrations ranging from 10 to 25 µg/mL. Nuclear imaging of osteoblast cells treated with EAL concentrate at 25 µg/mL concentration shows typical symptoms of apoptosis. In vitro cytotoxicity along with nuclear imaging confirmed EAL concentrate from soursop to be a potential drug candidate in developing new anti-cancer agent against osteosarcoma. [ABSTRACT FROM AUTHOR]

Introduction and the purpose of work Infective endocarditis (IE) is a disease diagnosed more and more often in recent years. Its treatment and diagnostics require a team of qualified specialists and are based on microbiological and imaging diagnostics. The purpose of this work is a summary and comparison of individual IE diagnostic methods, including their advantages and disadvantages. State of knowledge: Diagnosis of infective endocarditis relies on positive blood cultures to identify the microorganism and its drug sensitivity. Advanced methods like MALDI-TOF MS and MIC are used for identification. The first-line imaging diagnostic method for IE is echocardiography, which assesses structural and functional heart damage. Variants include transthoracic (TTE), transesophageal (TOE), three-dimensional TOE, and intracardiac echocardiography. Echocardiography should be performed immediately when IE is suspected. Computed tomography (CT) is crucial for diagnosing infective endocarditis (IE), particularly perivalvular and periprosthetic complications. Whole-body CT, including the brain, detects distant lesions and sources of bacteremia. CT is more accessible in emergencies and effective in spotting ischemic and hemorrhagic complications. CT angiography identifies mycotic aneurysms in the vascular system. It also detects extracardiac sources of bacteremia, aiding treatment and pre-surgery planning. Nuclear imaging is also important in diagnosing IE, especially prosthetic valve endocarditis (PVE) when echocardiography is inconclusive. 18F-fluorodeoxyglucose-PET/CT and SPECT/CT with labeled leukocytes are recommended. Conclusions: In addition to basic methods such as positive blood culture and echocardiography, there are more specialized methods that also allow for the assessment of treatment progress and prognosis.

Abstract Background Transthyretin amyloid cardiomyopathy (ATTR-CM), characterized by the extracellular deposition of an insoluble amyloid protein in the heart, is one of the main causes of heart failure in elderly patients. In this study, our primary objective was to explore the diverse applications and temporal significance of 1-h and 3-h imaging using 99mTc-PYP in the context of ATTR-CM. Additionally, we compared tracer kinetics in the heart and bone to comprehensively assess the diagnostic advantages and time-related considerations associated with these two incubation periods. Methods Twenty-seven patients at Nagasaki University Hospital who underwent 99mTc-PYP planar, and SPECT cardiac imaging were classified into two groups (ATTR-CM-positive and -negative groups) based on the American Heart Association statement. Cardiac retention was assessed with both a semiquantitative visual score and a quantitative analysis. To assess bone accumulation, a ROI with an equal volume was drawn on the sternum and calculated as the bone-to-contralateral ratio (B/CL). We also evaluated correlation between heart-to-contralateral lung (H/CL) ratio and left ventricular wall thickness. Results Among patients who underwent 99mTc-PYP imaging, the H/CL ratio was significantly higher at 1 h than at 3 h regardless of the group (from 2.20 ± 0.36 to 1.99 ± 0.35, p

Hypertrophic cardiomyopathy (HCM) is characterized by abnormal growth of the myocardium with myofilament disarray and myocardial hyper-contractility, leading to left ventricular hypertrophy and fibrosis. Where culprit genes are identified, they typically relate to cardiomyocyte sarcomere structure and function. Multi-modality imaging plays a crucial role in the diagnosis, monitoring, and risk stratification of HCM, as well as in screening those at risk. Following the recent publication of the first European Society of Cardiology (ESC) cardiomyopathy guidelines, we build on previous reviews and explore the roles of electrocardiography, echocardiography, cardiac magnetic resonance (CMR), cardiac computed tomography (CT), and nuclear imaging. We examine each modality's strengths along with their limitations in turn, and discuss how they can be used in isolation, or in combination, to facilitate a personalized approach to patient care, as well as providing key information and robust safety and efficacy evidence within new areas of research. [ABSTRACT FROM AUTHOR]

Cardiac amyloidosis is a disease in which proteins misfold and deposit as amyloid fibrils infiltrating the extracellular space within the myocardium. Sarcoidosis has been a well-recognized multisystem disease entity for several decades; however, the exact pathophysiological mechanism is still unknown. Over the years, significant advances in multimodality cardiac imaging are leading to increased diagnosis of both of these infiltrative cardiomyopathy disease states. This case-based state-of-the-art review encompasses the practically applicable diagnostic algorithms while highlighting the pros and cons of utilizing each of the advanced cardiac imaging modalities, and their application in real world medical practice via clinical teaching case vignettes. [ABSTRACT FROM AUTHOR]

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a complex and serious form of heart failure caused by the accumulation of transthyretin amyloid protein in the heart muscle. Variable symptoms of ATTR-CM can lead to a delayed diagnosis. Recognizing the diagnostic indicators is crucial to promptly detect this condition. A targeted literature review was conducted to examine the latest international consensus recommendations on a comprehensive diagnosis of ATTR-CM. Additionally, a panel consisting of nuclear medicine expert consultants (n = 10) and nuclear imaging technicians (n = 2) convened virtually from the Kingdom of Saudi Arabia (KSA) to formulate best practices for ATTR-CM diagnosis. The panel reached a consensus on a standard diagnostic pathway for ATTR-CM, which commences by evaluating the presence of clinical red flags and initiating a cardiac workup to assess the patient's echocardiogram. Cardiac magnetic resonance imaging may be needed, in uncertain cases. When there is a high suspicion of ATTR-CM, patients undergo nuclear scintigraphy and hematologic tests to rule out primary or light-chain amyloidosis. The expert panel emphasized that implementing best practices will support healthcare professionals in KSA to improve their ability to detect and diagnose ATTR-CM more accurately and promptly. Diagnosing ATTR-CM accurately and early can reduce morbidity and mortality rates through appropriate treatment. [ABSTRACT FROM AUTHOR]

Background: Transthyretin amyloid cardiomyopathy (ATTR-CM), characterized by the extracellular deposition of an insoluble amyloid protein in the heart, is one of the main causes of heart failure in elderly patients. In this study, our primary objective was to explore the diverse applications and temporal significance of 1-h and 3-h imaging using 99mTc-PYP in the context of ATTR-CM. Additionally, we compared tracer kinetics in the heart and bone to comprehensively assess the diagnostic advantages and time-related considerations associated with these two incubation periods. Methods: Twenty-seven patients at Nagasaki University Hospital who underwent 99mTc-PYP planar, and SPECT cardiac imaging were classified into two groups (ATTR-CM-positive and -negative groups) based on the American Heart Association statement. Cardiac retention was assessed with both a semiquantitative visual score and a quantitative analysis. To assess bone accumulation, a ROI with an equal volume was drawn on the sternum and calculated as the bone-to-contralateral ratio (B/CL). We also evaluated correlation between heart-to-contralateral lung (H/CL) ratio and left ventricular wall thickness. Results: Among patients who underwent 99mTc-PYP imaging, the H/CL ratio was significantly higher at 1 h than at 3 h regardless of the group (from 2.20 ± 0.36 to 1.99 ± 0.35, p < 0.01 in the positive group and from 1.35 ± 0.12 to 1.19 ± 0.21, p = 0.01 in the negative group). The gap of H/CL between highest H/CL of negative case and lowest H/CL of positive case was narrower in 3 h. On the other hand, correlation between H/CL and left ventricular posterior wall thickness tends to be clearer in 3 h (p = 0.12, r = 0.30 for 1 h, p = 0.04, r = 0.39 at 3 h). Conclusion: Our study suggests that both 1-h and 3-h incubation times for 99mTc-PYP imaging have different benefits for ATTR cardiac amyloidosis. A one-hour incubation may be preferable for differential diagnostic purposes, while a three-hour incubation may provide greater utility in evaluating disease severity. [ABSTRACT FROM AUTHOR]

I-123 is preferential over I-131 for diagnostic SPECT imaging after a thyroidectomy to determine the presence and size of residual thyroid tissue for radioiodine ablation. Scattering degrades the quality of I-123 SPECT images, primarily due to the penetration of high-energy photons into the main photopeak. The objective of this study was to quantitatively and qualitatively investigate the impact of two widely used window-based scatter correction techniques, the dual energy window (DEW) and triple energy window (TEW) techniques, in I-123 postsurgical SPECT/CT thyroid imaging using an anthropomorphic phantom with small sizes of remnants and anatomically correct surrounding structures. For this purpose, non-scatter-corrected, DEW and TEW scatter-corrected SPECT/CT acquisitions were performed for 0.5–10 mL remnants within a phantom, with 0.5–12.6 MBq administered activities within the remnants, and without and with background-to-remnant activity ratios of 5% and 10%. The decrease in photons, the noise and non-uniformity in the background region due to scatter correction were measured, as well as the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) from small remnants. The images were also visually evaluated by two experienced nuclear medicine physicians. Scatter correction decreased photons to a higher extent in larger regions than smaller regions. Larger remnants yielded higher SNR and CNR values, particularly at lower background activities. It was found from the quantitative analysis and the qualitative evaluation that TEW scatter correction performed better than DEW scatter correction, particularly at higher background activities, while no significant differences were reported at lower background activities. Scatter correction should be applied in I-123 postsurgical SPECT/CT imaging to improve the image contrast and detectability of small remnants within the background. [ABSTRACT FROM AUTHOR]

Bradykinin B1 receptor (B1R) has garnered attention as a cancer therapeutic and diagnostic target. Several reports on radiolabelled derivatives of B1R antagonists have shown favourable properties as imaging agents in cells highly expressing hB1R following transfection. In the present study, we assessed whether radiolabelled probes can detect B1R endogenously expressed in cancer cells. To this end, we evaluated 111In-labelled derivatives of a B1R antagonist ([111In]In-DOTA-Ahx-R954) using glioblastoma cell lines (U87MG and U251MG) with different B1R expression levels. Cellular uptake studies showed that the specific accumulation of [111In]In-DOTA-Ahx-R954 in U87MG was higher than that in U251MG, which correlated with B1R expression levels. Tissue distribution in U87MG-bearing mice revealed approximately 2-fold higher radioactivity in tumours than in the muscle in the contralateral leg. The specific accumulation of [111In]In-DOTA-Ahx-R954 in the tumour was demonstrated by the reduction in the tumour-to-plasma ratios in nonlabelled R954-treated mice. Moreover, ex vivo autoradiographic images revealed that the intratumoural distribution of [111In]In-DOTA-Ahx-R954 correlated with the localisation of B1R-expressing glioblastoma cells. In conclusion, we demonstrated that [111In]In-DOTA-Ahx-R954 radioactivity correlated with B1R expression in glioblastoma cells, indicating that radiolabelled derivatives of the B1R antagonist could serve as promising tools for elucidating the involvement of B1R in cancer.

Background: Human papilloma virus (HPV) infection is an important risk factor in oropharyngeal cancer. Several studies have analyzed the association of tumoral HPV status and different imaging parameters in FDG-PET/CT and magnetic resonance (MR) diffusion-weighted imaging (DWI), with contradictory findings. In this retrospective study, the influence of HPV-status on different parameters in FDG-imaging and MR DWI is investigated. Methods: In this retrospective, single-center study we analyzed patients diagnosed with oropharyngeal cancer between January 2018 and December 2020 at a tertiary center in Switzerland. HPV status was assessed via p16 immunohistochemistry and/or PCR. Standardized uptake value (SUV), total lesion glycolysis (TLG) and apparent diffusion coefficient (ADC) were measured in pretreatment imaging (FDG-PET/CT, FDG-PET/MR, DWI MR). Statistical analysis was performed using Mann-Whitney-U tests. All p values reported are two-sided, and p values

The article discusses the results of the COLD-MI trial, which aimed to explore the impact of colchicine on myocardial denervation in patients who had experienced an acute myocardial infarction (AMI). The study found that colchicine reduced myocardial denervation in both the infarcted and non-infarcted zones of the heart. However, there were no significant effects on other parameters such as necrosis size or left ventricular ejection fraction. The study also noted an increase in gastrointestinal side effects with colchicine use. Overall, the findings suggest that colchicine may have a positive effect on reducing cardiac denervation in patients after AMI. [Extracted from the article]

Cardiac allograft vasculopathy (CAV) is a distinct form of coronary artery disease that represents a major cause of death beyond the first year after heart transplantation. The pathophysiology of CAV is still not completely elucidated; it involves progressive circumferential wall thickening of both the epicardial and intramyocardial coronary arteries. Coronary angiography is still considered the gold-standard test for the diagnosis of CAV, and intravascular ultrasound (IVUS) can detect early intimal thickening with improved sensitivity. However, these tests are invasive and are unable to visualize and evaluate coronary microcirculation. Increasing evidence for non-invasive surveillance techniques assessing both epicardial and microvascular components of CAV may help improve early detection. These include computed tomography coronary angiography (CTCA), single-photon emission computed tomography (SPECT), positron emission tomography (PET), and vasodilator stress myocardial contrast echocardiography perfusion imaging. This review summarizes the current state of diagnostic modalities and their utility and prognostic value for CAV and also evaluates emerging tools that may improve the early detection of this complex disease.

I-123 is preferential over I-131 for diagnostic SPECT imaging after a thyroidectomy to determine the presence and size of residual thyroid tissue for radioiodine ablation. Scattering degrades the quality of I-123 SPECT images, primarily due to the penetration of high-energy photons into the main photopeak. The objective of this study was to quantitatively and qualitatively investigate the impact of two widely used window-based scatter correction techniques, the dual energy window (DEW) and triple energy window (TEW) techniques, in I-123 postsurgical SPECT/CT thyroid imaging using an anthropomorphic phantom with small sizes of remnants and anatomically correct surrounding structures. For this purpose, non-scatter-corrected, DEW and TEW scatter-corrected SPECT/CT acquisitions were performed for 0.5–10 mL remnants within a phantom, with 0.5–12.6 MBq administered activities within the remnants, and without and with background-to-remnant activity ratios of 5% and 10%. The decrease in photons, the noise and non-uniformity in the background region due to scatter correction were measured, as well as the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) from small remnants. The images were also visually evaluated by two experienced nuclear medicine physicians. Scatter correction decreased photons to a higher extent in larger regions than smaller regions. Larger remnants yielded higher SNR and CNR values, particularly at lower background activities. It was found from the quantitative analysis and the qualitative evaluation that TEW scatter correction performed better than DEW scatter correction, particularly at higher background activities, while no significant differences were reported at lower background activities. Scatter correction should be applied in I-123 postsurgical SPECT/CT imaging to improve the image contrast and detectability of small remnants within the background.

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a complex and serious form of heart failure caused by the accumulation of transthyretin amyloid protein in the heart muscle. Variable symptoms of ATTR-CM can lead to a delayed diagnosis. Recognizing the diagnostic indicators is crucial to promptly detect this condition. A targeted literature review was conducted to examine the latest international consensus recommendations on a comprehensive diagnosis of ATTR-CM. Additionally, a panel consisting of nuclear medicine expert consultants (n = 10) and nuclear imaging technicians (n = 2) convened virtually from the Kingdom of Saudi Arabia (KSA) to formulate best practices for ATTR-CM diagnosis. The panel reached a consensus on a standard diagnostic pathway for ATTR-CM, which commences by evaluating the presence of clinical red flags and initiating a cardiac workup to assess the patient’s echocardiogram. Cardiac magnetic resonance imaging may be needed, in uncertain cases. When there is a high suspicion of ATTR-CM, patients undergo nuclear scintigraphy and hematologic tests to rule out primary or light-chain amyloidosis. The expert panel emphasized that implementing best practices will support healthcare professionals in KSA to improve their ability to detect and diagnose ATTR-CM more accurately and promptly. Diagnosing ATTR-CM accurately and early can reduce morbidity and mortality rates through appropriate treatment.

Infective endocarditis (IE) represents a significant concern among hospital-acquired infections, frequently caused by the Gram-positive bacterium Staphylococcus aureus . Nuclear imaging is emerging as a noninvasive and precise diagnostic tool. However, the gold standard radiotracer [ 18 F]-FDG cannot distinguish between infection and inflammation, resulting in false positives. Based on the presence of collagen-binding proteins in the cell wall of S. aureus , we propose the radiolabeling of collagen for its evaluation in IE animal models by single-photon emission computed tomography (SPECT) imaging. We radiolabeled rat tail collagen I using DTPA chelator and [ 99m Tc]NaTcO 4 . Selectivity was evaluated in vitro using 3 Gram-positive bacteria, 1 Gram-negative bacteria and 1 yeast. In vivo SPECT/computed tomography (CT) imaging was conducted on 8 SD rat models of IE and 8 sterile sham model as controls. Ex vivo biodistribution and autoradiography were performed following imaging. Diagnosis of IE was confirmed through microbiological studies and H&E histopathology. [ 99m Tc]-DTPA-Collagen was synthesized successfully with a yield of 42.86 ± 6.35%, a purity of 95.84 ± 1.85% and a stability higher than 90% after 50 h postincubation. In vitro uptake demonstrated the selectivity for Gram-positive bacteria (63.85 ± 15.15%). Ex vivo analysis confirmed hepato-splenic excretion. In vivo SPECT/CT imaging revealed highly localized uptake within the aortic valve with a sensitivity of 62.5% and specificity of 87.5%. We successfully synthesized and characterized a new SPECT radiotracer based on [ 99m Tc]Tc-radiolabeled collagen. In vitro studies demonstrated the selectivity of the radiotracer for Gram-positive bacteria. In vivo SPECT/CT-based assessment in an IE model confirmed the potential of this approach to detect active IE.

Immunotherapy has significantly improved cancer patient survival, while its efficacy remains limited due to the reliance on a single marker like PD-L1 as well as its spatiotemporal heterogeneity. To address this issue, combining lymphocyte activation gene-3 (LAG-3) with PD-L1 is proposed for identifying immunotypes and monitoring immunotherapy through nuclear imaging. In short, 99m Tc-HYNIC-αLAG-3 and 99m Tc-HYNIC-αPD-L1 probes are synthesized using anti-human LAG-3 and PD-L1 antibodies, respectively. With high radiochemical purity and in vitro stability, these probes are confirmed to specifically bind to LAG-3 or PD-L1 in LAG3 + A549, LAG3 - A549, and H1975 cells. SPECT/CT imaging of both probes showed specific in vivo tumor uptake in multiple lung cancer models, with significant linear correlation with ex vivo tumor uptake and immunohistochemical expression levels of LAG-3/PD-L1. Based on this, dual-index imaging was performed to simultaneously quantify LAG-3 and PD-L1. SPECT/CT imaging of 99m Tc-HYNIC-αLAG-3 and 125 I-αPD-L1 successfully distinguished four immunotypes. In addition, SPECT/CT imaging revealed LAG-3 upregulation in LLC-bearing LAG-3 humanized mice resistant to immunotherapy. In conclusion, this study demonstrates the feasibility of nuclear imaging of LAG-3 and PD-L1 for both noninvasive immunotyping and immunotherapy monitoring, thus offering novel perspectives on forecasting immunotherapy response, uncovering resistance mechanism, and optimizing combination treatment regimens., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Neuroendocrine tumors (NETs) as compared to its octreotide (NOC) counterpart when labeled with In-111 and Tc-99m. This study was aimed to develop easy to use, cost effective, and commercially available diagnostic kit of [99mTc][Tc-HYNIC-TATE] (Tyr3-Octreotate) indigenously to diagnose neuroendocrine tumors in Pakistan. HYNIC-TATE cold kit was optimized at 20µg of peptide (Octreotate), following co-ligand exchange labeling approach using EDDA/TRICINE (3:6 mg) while heating at 90 °C for 20 min. Radiochemical purity of [99mTc][Tc-HYNIC-TATE] was > 98 ± 0.14% when labeled with 550–850 MBq of Tc-99m and stable upto 12 h. Preclinical & clinical investigations validated the higher sensitivity and specificity of the developed kits for spot-on detection of neuroendocrine tumours (NETs).Graphical Abstract: Neuroendocrine tumors (NETs) as compared to its octreotide (NOC) counterpart when labeled with In-111 and Tc-99m. This study was aimed to develop easy to use, cost effective, and commercially available diagnostic kit of [99mTc][Tc-HYNIC-TATE] (Tyr3-Octreotate) indigenously to diagnose neuroendocrine tumors in Pakistan. HYNIC-TATE cold kit was optimized at 20µg of peptide (Octreotate), following co-ligand exchange labeling approach using EDDA/TRICINE (3:6 mg) while heating at 90 °C for 20 min. Radiochemical purity of [99mTc][Tc-HYNIC-TATE] was > 98 ± 0.14% when labeled with 550–850 MBq of Tc-99m and stable upto 12 h. Preclinical & clinical investigations validated the higher sensitivity and specificity of the developed kits for spot-on detection of neuroendocrine tumours (NETs). [ABSTRACT FROM AUTHOR]

Lymphangiogenesis at primary tumor and draining lymph nodes plays a pivotal role in tumor metastasis, which has been demonstrated to be regulated by the vascular endothelial growth factor receptor 3 (VEGFR-3) pathway. However, the effect of molecular imaging peptides, which specifically bind VEGFR-3, in tracing tumors remains unclear. We prepared a novel peptide, TMVP1448, with high-affinity to VEGFR-3. The dissociation constant (KD) of TMVP1448 with VEGFR-3 was 7.07 ×10‐7 M. In vitro cellular assay showed that TMVP1448 could bind specifically with VEGFR-3. Near infrared imaging results showed that Cy7-TMVP1448 was able to accurately trace primary and metastatic cancers, and PET/CT results showed that [68Ga]Ga-DOTA-TMVP1448 was superior to commonly used radiotracers 18F-FDG. Additionally, no significant negative effect of TMVP1448 was found in mice. Our results suggested that TMVP1448 had great potential for future clinical applications in fluorescence imaging and nuclear imaging of tumors. [ABSTRACT FROM AUTHOR]

In recent years, the application of radionuclides-containing nanomaterials in cancer treatment has garnered widespread attention. The diversity of nanomaterials allows researchers to selectively combine them with appropriate radionuclides for biomedical purposes, addressing challenges faced by peptides, small molecules, or antibodies used for radionuclide labeling. However, with advantages come challenges, and nanoradionuclides still encounter significant issues during clinical translation. This review summarized the recent progress of nanosized radionuclides for cancer treatment or diagnosis. The discussion began with representative radionuclides and the methods of incorporating them into nanomaterial structures. Subsequently, new combinations of nanomaterials and radionuclides, along with their applications, were introduced to demonstrate their future trends. The benefits of nanoradionuclides included optimized pharmacokinetic properties, enhanced disease-targeting efficacy, and synergistic application with other treatment techniques. Besides, the basic rule of this section was to summarize how these nanoradionuclides can truly impact the diagnosis and therapy of various cancer types. In the last part, the focus was devoted to the nanoradionuclides currently applicable in clinics and how to address the existing issues and problems based on our knowledge., (© 2024 The Author(s). WIREs Nanomedicine and Nanobiotechnology published by Wiley Periodicals LLC.)

The evolving landscape of cancer immunotherapy has revolutionized cancer treatment. However, the dynamic tumor microenvironment has led to variable clinical outcomes, indicating a need for predictive biomarkers. Noninvasive nuclear imaging, using radiolabeled modalities, has aided in patient selection and monitoring of their treatment response. This approach holds promise for improving diagnostic accuracy, providing a more personalized treatment regimen, and enhancing the clinical response. Nanobodies or single-domain antibodies, derived from camelid heavy-chain antibodies, allow early timepoint detection of targets with high target-to-background ratios. To date, a plethora of nanobodies have been developed for nuclear imaging of tumor-specific antigens, immune checkpoints, and immune cells, both at a preclinical and clinical level. This review comprehensively outlines the recent advancements in nanobody-based nuclear imaging, both on preclinical and clinical levels. Additionally, the impact and expected future advancements on the use of nanobody-based radiopharmaceuticals in supporting cancer diagnosis and treatment follow-up are discussed., Competing Interests: Nick Devoogdt is co-founder of the companies Precirix and Abscint., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Immunology.)

Background: Infective endocarditis (IE) is a serious and fatal condition, with prosthetic valve endocarditis representing the worst prognosis. The recommended nuclear imaging modality 2-deoxy-2-[ 18 F]fluoro-D-glucose positron emission tomography/computed tomography ([ 18 F]FDG PET/CT) has limitations. In this case series, we present two patients with IE scanned with a novel PET tracer [ 64 Cu]Cu-DOTATATE ([ 64 Cu]Cu-[1,4,7,10-tetraazacyclododecane- N , N ', N ″, N ‴-tetra acetic acid]-d-Phe1, Tyr3-octreotate)., Case Summary: An 84-year-old female patient (Patient 1) with a biological mitral valve prosthesis (MVP) was admitted acutely from the outpatient clinic. Transoesophageal echocardiography showed vegetations on the MVP. The patient underwent [ 64 Cu]Cu-DOTATATE PET/CT, which showed uptake at the site of infection. The patient underwent surgical valve replacement. The post-operative period was without significant complications, and the patient was discharged home. In another case, a 72-year-old male patient (Patient 2) with a medical history of mild mitral valve stenosis, aortic valve stenosis, and gastrointestinal stromal tumour was admitted to the hospital for back and abdominal pain and subfebrile episodes. Transoesophageal echocardiography showed large vegetations in the native aortic valve. The patient underwent [ 64 Cu]Cu-DOTATATE PET/CT, which showed no uptake at the site of the suspected infection. The patient underwent surgical valve replacement. The post-operative period was characterized by Candida albicans sternitis, and after prolonged hospitalization, the patient died of respiratory failure as a complication of sepsis., Discussion: In conclusion, this is the first case series presenting two patients with definite IE (modified Duke criteria), who were scanned with the novel [ 64 Cu]Cu-DOTATATE PET/CT. Patient 1, with endocarditis in the MVP, showed an uptake of the tracer, while Patient 2, with native aortic valve endocarditis, did not show any uptake., Competing Interests: Conflict of interest: K.H.-T., M.Ø.F., P.H., and R.S.R.: none declared. A.K.: inventor/holds IPR on a patent covering [64Cu]Cu-DOTATATE for use in neuroendocrine tumours. L.K. has received lecture fees from Astra Zeneca, Bayer, Boehringer, Novartis, and Novo, unrelated to this manuscript. E.F. has received independent research grant related to valvular heart disease and endocarditis from the Novo Nordisk Foundation and the Danish Heart Association, unrelated to this manuscript., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Human brain morphology undergoes complex changes over the lifespan. Despite recent progress in tracking brain development via normative models, current knowledge of underlying biological mechanisms is highly limited. We demonstrate that human cortical thickness development and aging trajectories unfold along patterns of molecular and cellular brain organization, traceable from population-level to individual developmental trajectories. During childhood and adolescence, cortex-wide spatial distributions of dopaminergic receptors, inhibitory neurons, glial cell populations, and brain-metabolic features explain up to 50% of variance associated with a lifespan model of regional cortical thickness trajectories. In contrast, modeled cortical thickness change patterns during adulthood are best explained by cholinergic and glutamatergic neurotransmitter receptor and transporter distributions. These relationships are supported by developmental gene expression trajectories and translate to individual longitudinal data from over 8,000 adolescents, explaining up to 59% of developmental change at cohort- and 18% at single-subject level. Integrating neurobiological brain atlases with normative modeling and population neuroimaging provides a biologically meaningful path to understand brain development and aging in living humans., Competing Interests: 10.Competing interest All other authors report no biomedical financial interest or other potential conflicts of interest.

Background: Coronary artery disease (CAD) can masquerade as other illnesses due to its varied presentations, the co-existence of other chest pain etiologies, and the limitations of diagnostic modalities., Case Report: We present a case of ambiguous chest pain due to multiple possible etiologies, including acute coronary syndrome (ACS), where initial cardiological testing yielded negative results. This led to a delay of 112 days in establishing the diagnosis and initiating appropriate treatment., Conclusion: This case emphasizes the crucial role of clinical context and risk stratification in chest pain evaluation. It is imperative to interpret cardiovascular test results carefully, taking into account the sensitivities, specificities, scope, and limitations of the utilized modalities., Competing Interests: Conflict of interest: The authors declare no conflict of interest., (© 2024 Greater Baltimore Medical Center.)

Rationale: AXL expression has been identified as a prognostic factor in acute myeloid leukemia (AML) and is detectable in approximately 50% of AML patients. In this study, we developed AXL-specific single domain antibodies (sdAbs), cross-reactive for both mouse and human AXL protein, to non-invasively image and treat AXL-expressing cancer cells. Methods: AXL-specific sdAbs were induced by immunizing an alpaca with mouse and human AXL proteins. SdAbs were characterized using ELISA, flow cytometry, surface plasmon resonance and the AlphaFold2 software. A lead compound was selected and labeled with 99m Tc for evaluation as a diagnostic tool in mouse models of human (THP-1 cells) or mouse (C1498 cells) AML using SPECT/CT imaging. For therapeutic purposes, the lead compound was fused to a mouse IgG2a-Fc tail and in vitro functionality tests were performed including viability, apoptosis and proliferation assays in human AML cell lines and primary patient samples. Using these in vitro models, its anti-tumor effect was evaluated as a single agent, and in combination with standard of care agents venetoclax or cytarabine. Results: Based on its cell binding potential, cross-reactivity, nanomolar affinity and GAS6/AXL blocking capacity, we selected sdAb20 for further evaluation. Using SPECT/CT imaging, we observed tumor uptake of 99m Tc-sdAb20 in mice with AXL-positive THP-1 or C1498 tumors. In THP-1 xenografts, an optimized protocol using pre-injection of cold sdAb20-Fc was required to maximize the tumor-to-background signal. Besides its diagnostic value, we observed a significant reduction in tumor cell proliferation and viability using sdAb20-Fc in vitro . Moreover, combining sdAb20-Fc and cytarabine synergistically induced apoptosis in human AML cell lines, while these effects were less clear when combined with venetoclax. Conclusions: Because of their diagnostic potential, sdAbs could be used to screen patients eligible for AXL-targeted therapy and to follow-up AXL expression during treatment and disease progression. When fused to an Fc-domain, sdAbs acquire additional therapeutic properties that can lead to a multidrug approach for the treatment of AXL-positive cancer patients., Competing Interests: Competing Interests: N.D. is co-founder and scientific consultant at Precirix NV and ABSCINT NV. All other authors declare no conflict of interest., (© The author(s).)

Parkinson's disease (PD) is a widespread progressive neurodegenerative disease. Clinical diagnosis approaches are insufficient to provide an early and accurate diagnosis before a substantial of loss of dopaminergic neurons. PET and SPECT can be used for accurate and early diagnosis of PD by using target-specific radiotracers. Additionally, the importance of BBB penetrating targeted nanosystems has increased in recent years. This article reviews targeted radiopharmaceuticals used in clinics and novel nanocarriers for research purposes of PD imaging. [Display omitted] • An extensive review of radiotracers used for Parkinson's disease imaging and recent developments are focused. • Molecular imaging techniques and limitations of conventional diagnostic methods in Parkinson's disease are mentioned. • Challenges in imaging of PD and BBB penetration are explained. • Nanocarriers as novel radiopharmaceuticals are mentioned in place of Parkinson's disease imaging that is presented. [ABSTRACT FROM AUTHOR]

Cardiac allograft vasculopathy (CAV) is a distinct form of coronary artery disease that represents a major cause of death beyond the first year after heart transplantation. The pathophysiology of CAV is still not completely elucidated; it involves progressive circumferential wall thickening of both the epicardial and intramyocardial coronary arteries. Coronary angiography is still considered the gold-standard test for the diagnosis of CAV, and intravascular ultrasound (IVUS) can detect early intimal thickening with improved sensitivity. However, these tests are invasive and are unable to visualize and evaluate coronary microcirculation. Increasing evidence for non-invasive surveillance techniques assessing both epicardial and microvascular components of CAV may help improve early detection. These include computed tomography coronary angiography (CTCA), single-photon emission computed tomography (SPECT), positron emission tomography (PET), and vasodilator stress myocardial contrast echocardiography perfusion imaging. This review summarizes the current state of diagnostic modalities and their utility and prognostic value for CAV and also evaluates emerging tools that may improve the early detection of this complex disease.

Objective . This paper addresses performing inverse radon transform (IRT) with artificial neural network (ANN) or deep learning, simultaneously with cardiac motion correction (MC). The suggested application domain is cardiac image reconstruction in emission or transmission tomography where IRT is relevant. Our main contribution is in proposing an ANN architecture that is particularly suitable for this purpose. Approach . We validate our approach with two types of datasets. First, we use an abstract object that looks like a heart to simulate motion-blurred radon transform. With the known ground truth in hand, we then train our proposed ANN architecture and validate its effectiveness in MC. Second, we used human cardiac gated datasets for training and validation of our approach. The gating mechanism bins data over time using the electro-cardiogram (ECG) signals for cardiac motion correction. Main results . We have shown that trained ANNs can perform motion-corrected image reconstruction directly from a motion-corrupted sinogram. We have compared our model against two other known ANN-based approaches. Significance . Our method paves the way for eliminating any need for hardware gating in medical imaging., (© 2024 Institute of Physics and Engineering in Medicine.)

Infective endocarditis (IE) is an increasingly recognized condition with high morbidity. Patients with atypical symptoms, culture-negative infections, and prosthetic cardiac devices and implants represent challenging populations to evaluate and manage. Recent major society guidelines have recommended the appropriate incorporation of multimodality imaging in the evaluation of these more complex IE cases. This article draws on the available literature regarding the different cardiac imaging modalities and discusses the role of multimodality imaging in IE.

COVID-19 pandemic has heightened the interest toward diagnosis and treatment of infectious diseases. Nuclear medicine, with its powerful scintigraphic, single photon emission computer tomography (SPECT), and positron emission tomography (PET) imaging modalities, has always played an important role in diagnosis of infections and distinguishing them from the sterile inflammation. In addition to the clinically available radiopharmaceuticals, there has been a decades-long effort to develop more specific imaging agents with some examples being radiolabeled antibiotics and antimicrobial peptides for bacterial imaging, radiolabeled antifungals for fungal infections imaging, radiolabeled pathogen-specific antibodies, and molecular engineered constructs. In this chapter, we discuss some examples of the work published in the last decade on developing nuclear imaging agents for bacterial, fungal, and viral infections to generate more interest among nuclear medicine community toward conducting clinical trials of these novel probes, as well as toward developing novel radiotracers for imaging infections., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

In this review we have brought forward various nuclear imaging modalities used in the diagnosis, staging, and management of thyroid cancer. Thyroid cancer is the most common endocrine malignancy, accounting for approximately 3% of all new cancer diagnoses. Nuclear imaging plays an important role in the evaluation of thyroid cancer, and the use of radioiodine imaging, FDG imaging, and somatostatin receptor imaging are all valuable tools in the management of this disease. Radioiodine imaging involves the use of Iodine-123 [I-123] or Iodine-131 [I-131] to evaluate thyroid function and detect thyroid cancer. I-123 is a gamma-emitting isotope that is used in thyroid imaging to evaluate thyroid function and detect thyroid nodules. I-131 is a beta-emitting isotope that is used for the treatment of thyroid cancer. Radioiodine imaging is used to detect the presence of thyroid nodules and evaluate thyroid function. FDG imaging is a PET imaging modality that is used to evaluate the metabolic activity of thyroid cancer cells. FDG is a glucose analogue that is taken up by cells that are metabolically active, such as cancer cells. FDG PET/CT can detect primary thyroid cancer and metastatic disease, including lymph nodes and distant metastases. FDG PET/CT is also used to monitor treatment response and detect the recurrence of thyroid cancer. Somatostatin receptor imaging involves the use of radiolabeled somatostatin analogues to detect neuroendocrine tumors, including thyroid cancer. Radiolabeled somatostatin analogues, such as Indium-111 octreotide or Gallium-68 DOTATATE, are administered to the patient, and a gamma camera is used to detect areas of uptake. Somatostatin receptor imaging is highly sensitive and specific for the detection of metastatic thyroid cancer. A comprehensive search of relevant literature was done using online databases of PubMed, Embase, and Cochrane Library using the keywords "thyroid cancer," "nuclear imaging," "radioiodine imaging," "FDG PET/CT," and "somatostatin receptor imaging" to identify relevant studies to be included in this review. Nuclear imaging plays an important role in the diagnosis, staging, and management of thyroid cancer. The use of radioiodine imaging, thyroglobulin imaging, FDG imaging, and somatostatin receptor imaging are all valuable tools in the evaluation of thyroid cancer. With further research and development, nuclear imaging techniques have the potential to improve the diagnosis and management of thyroid cancer and other endocrine malignancies., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Aim: Tumor markers often remain elevated after intended curative resection of medullary thyroid carcinoma (MTC). The aim of this study was to determine the expression of α v β 3 , a promising theranostics target, in MTC and its metastases. Materials & methods: A v β 3 expression was analyzed in 104 patients using a tissue microarray and correlated with clinicopathological variables and survival. Results: Cytoplasmic α v β 3 positivity was seen in 70 patients and was associated with lymph node metastases at time of initial surgery. Membranous positivity was considered positive in 30 patients and was associated with sporadic MTC. Conclusion: A v β 3 was expressed in the cytoplasm of 67% of MTC patients. Membranous expression, which is presumably most relevant for the theranostic use of α v β 3 , was seen in 29%.

Parkinsonian disorders are a heterogeneous group of incurable neurodegenerative diseases that significantly reduce quality of life and constitute a substantial economic burden. Nuclear imaging (NI) and magnetic resonance imaging (MRI) have played and continue to play a key role in research aimed at understanding and monitoring these disorders. MRI is cheaper, more accessible, nonirradiating, and better at measuring biological structures and hemodynamics than NI. NI, on the other hand, can track molecular processes, which may be crucial for the development of efficient diseasemodifying therapies. Given the strengths and weaknesses of NI and MRI, how can they best be applied to Parkinsonism research going forward? This review aims to examine the effectiveness of NI and MRI in three areas of Parkinsonism research (differential diagnosis, prodromal disease identification, and disease monitoring) to highlight where they can be most impactful. Based on the available literature, MRI can assist with differential diagnosis, prodromal disease identification, and disease monitoring as well as NI. However, more work is needed, to confirm the value of MRI for monitoring prodromal disease and predicting phenoconversion. Although NI can complement or be a substitute for MRI in all the areas covered in this review, we believe that its most meaningful impact will emerge once reliable Parkinsonian proteinopathy tracers become available. Future work in tracer development and high-field imaging will continue to influence the landscape for NI and MRI., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)