Single Photon Emission Research Articles

A Review on Cancer Diagnostic and Therapeutic Considerations in Dogs

Cancer presents a significant health concern in dogs, similar to its impact on humans, and stands as a primary contributor to canine mortality. The elevated incidence of cancer in dogs, relative to other domesticated animals, may be attributed to their intimate companionship with humans, advanced medical diagnostics, and elevated healthcare standards that have extended their lifespans beyond typical expectations, although accompanied by a heightened susceptibility to cancer. Effective diagnosis and treatment of canine cancer hinge upon a comprehensive understanding of tumor varieties, their underlying pathophysiology, and molecular alterations affecting genes and proteins. A range of diagnostic tools is employed for detecting cancer in dogs, encompassing blood profiles, cytological evaluations, histopathology, immunohistochemistry, and various imaging methods such as computed tomography, magnetic resonance imaging, positron emission tomography, and single-photon emission computed tomography. Additionally, molecular techniques play a crucial role. Therapeutic options for addressing canine cancer encompass chemotherapy, surgical procedures, and radiation therapy. Furthermore, promising developments including cancer vaccines and novel anti-cancer medications are currently undergoing clinical trials, aiming to enhance the management of cancer in dogs. This article provides an overview of both current and emerging diagnostic and treatment approaches, whether currently available or in the experimental stage, for effectively managing cancer in dogs.

Advancements in molecular imaging probes for precision diagnosis and treatment of prostate cancer.

Prostate cancer is the second most common cancer in men, accounting for 14.1% of new cancer cases in 2020. The aggressiveness of prostate cancer is highly variable, depending on its grade and stage at the time of diagnosis. Despite recent advances in prostate cancer treatment, some patients still experience recurrence or even progression after undergoing radical treatment. Accurate initial staging and monitoring for recurrence determine patient management, which in turn affect patient prognosis and survival. Classical imaging has limitations in the diagnosis and treatment of prostate cancer, but the use of novel molecular probes has improved the detection rate, specificity, and accuracy of prostate cancer detection. Molecular probe-based imaging modalities allow the visualization and quantitative measurement of biological processes at the molecular and cellular levels in living systems. An increased understanding of tumor biology of prostate cancer and the discovery of new tumor biomarkers have allowed the exploration of additional molecular probe targets. The development of novel ligands and advances in nano-based delivery technologies have accelerated the research and development of molecular probes. Here, we summarize the use of molecular probes in positron emission tomography (PET), single-photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), optical imaging, and ultrasound imaging, and provide a brief overview of important target molecules in prostate cancer.

Multi-Modality Imaging in Cardio-Rheumatology.

Our purpose was to discuss the advantages and disadvantages of various noninvasive imaging modalities in the evaluation of cardiovascular disease (CVD) in patients with autoimmune rheumatic diseases (ARDs). The detailed knowledge of imaging modalities will facilitate the diagnosis and follow up of CVD in ARDs. Autoimmune Rheumatic Diseases (ARDs) are characterized by alterations in immunoregulatory system of the body. Although there is great progress in anti-rheumatic treatment, ARD patients are still at a higher risk for reduced life expectancy, compared with the general population, which is mainly due to the high incidence of CVD. Cardiovascular imaging holds the promise of early, noninvasive diagnosis and follow up of these patients. Echocardiography (echo), a cost effective, widely available imaging modality, can provide valuable early information about CVD in ARDs and motivate the use of more sophisticated investigations, if needed. Single Photon Emission tomography (SPECT) gives information about myocardial perfusion, while positron emission tomography (PET) gives information about both myocardial perfusion and inflammation with better spatial resolution and less radiation but at a higher financial cost, compared to SPECT. Computed Tomography Coronary Angiography (CTCA) is a reliable tool to rule out the presence of coronary artery disease, which has high incidence in ARD population. Lastly, Cardiovascular Magnetic Resonance (CMR) can perform function and tissue characterization evaluation in the same scan without using radiation and represents the ideal tool for serial evaluation of ARD patients. Lastly, molecular imaging holds the promise for individualized treatment in various ARDs. Cardiovascular imaging is the modern "stethoscope" of the clinicians and therefore they should be familiar with pro and contra of these modalities in order to achieve the best diagnostic and therapeutic target in ARD patients.

Room Temperature Quantum Emitters in van der Waals α-MoO3.

Quantum emitters in solid-state materials are highly promising building blocks for quantum information processing and communication science. Recently, single-photon emission from van der Waals materials has been reported in transition metal dichalcogenides and hexagonal boron nitride, exhibiting the potential to realize photonic quantum technologies in two-dimensional materials. Here, we report the generation of room temperature single-photon emission from exfoliated and thermally annealed single crystals of van der Waals α-MoO3. The second-order correlation function measurement displays clear photon antibunching, while the luminescence intensity exceeds 0.4 Mcts/s and remains stable under laser excitation. The theoretical calculation suggests that an oxygen vacancy defect is a possible candidate for the observed emitters. Together with photostability and brightness, quantum emitters in α-MoO3 provide a new avenue to realize photon-based quantum information science in van der Waals materials.

Computationally efficient collimator-detector response compensation in high energy SPECT using 1D convolutions and rotations

Objective. Modeling of the collimator-detector response (CDR) in single photon emission computed tomography (SPECT) reconstruction enables improved resolution and accuracy, and is thus important for quantitative imaging applications such as dosimetry. The implementation of CDR modeling, however, can become a computational bottleneck when there are substantial components of septal penetration and scatter in the acquired data, since a direct convolution-based approach requires large 2D kernels. This work proposes a 1D convolution and rotation-based CDR model that reduces reconstruction times but maintains consistency with models that employ 2D convolutions. To enable open-source development and use of these models in image reconstruction, we release a SPECTPSFToolbox repository for the PyTomography project on GitHub.Approach. A 1D/rotation-based CDR model was formulated and subsequently fit to Monte Carlo (MC) point source data representative of177Lu,131I, and225Ac imaging. Computation times of (i) the proposed 1D/rotation-based model and (ii) a traditional model that uses 2D convolutions were compared for typical SPECT matrix sizes. Both CDR models were then used in the reconstruction of MC, physical phantom, and patient data; the models were compared by quantifying total counts in hot regions of interest (ROIs) and activity contrast between hot ROIs and background regions.Results. For typical matrix sizes in SPECT reconstruction, application of the 1D/rotation-based model provides a two-fold computational speed-up over the 2D model when running on GPU. Only small differences between the 1D/rotation-based and 2D models (order of 1%) were obtained for count and contrast quantification in select ROIs.Significance. A technique for CDR modeling in SPECT was proposed that (i) significantly speeds up reconstruction times, and (ii) yields nearly identical reconstructions to traditional 2D convolution based CDR techniques. The released toolbox will permit open-source development of similar models for different isotopes and collimators.

The potential role of machine learning and deep learning in differential diagnosis of Alzheimer's disease and FTD using imaging biomarkers: A review.

The prevalence of neurodegenerative diseases has significantly increased, necessitating a deeper understanding of their symptoms, diagnostic processes, and prevention strategies. Frontotemporal dementia (FTD) and Alzheimer's disease (AD) are two prominent neurodegenerative conditions that present diagnostic challenges due to overlapping symptoms. To address these challenges, experts utilize a range of imaging techniques, including magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), functional MRI (fMRI), positron emission tomography (PET), and single-photon emission computed tomography (SPECT). These techniques facilitate a detailed examination of the manifestations of these diseases. Recent research has demonstrated the potential of artificial intelligence (AI) in automating the diagnostic process, generating significant interest in this field. This narrative review aims to compile and analyze articles related to the AI-assisted diagnosis of FTD and AD. We reviewed 31 articles published between 2012 and 2024, with 23 focusing on machine learning techniques and 8 on deep learning techniques. The studies utilized features extracted from both single imaging modalities and multi-modal approaches, and evaluated the performance of various classification models. Among the machine learning studies, Support Vector Machines (SVM) exhibited the most favorable performance in classifying FTD and AD. In deep learning studies, the ResNet convolutional neural network outperformed other networks. This review highlights the utility of different imaging modalities as diagnostic aids in distinguishing between FTD and AD. However, it emphasizes the importance of incorporating clinical examinations and patient symptom evaluations to ensure comprehensive and accurate diagnoses.

How to Use Imaging: Complex Cases of Atherosclerosis, Myocardial Inflammation, and Cardiomyopathy in Cardio-Oncology.

It is well understood that cancer therapies including chemotherapy, tyrosine kinase inhibitors, immune checkpoint inhibitors, and radiation can increase the risk of cardiovascular disease in patients with cancer. This can manifest as a multitude of pathologies including left ventricular dysfunction, myocarditis, cardiomyopathy, accelerated atherosclerosis, and coronary vasospasm. Multimodal cardiac imaging plays a critical role in diagnosing such pathologies by relying on noninvasive tools including echocardiograms, cardiac magnetic resonance imaging, positron emission tomography, single-photon emission computed tomography, and coronary computed tomography angiography. These methods have unique considerations and in recent years have made significant progress in their diagnostic capabilities in this patient population. As the field of cardio-oncology continues to expand rapidly, guidance on the management of such toxicities and the development of imaging technologies is crucial. In this review, we present 2 complex cases of atherosclerosis and myocarditis in patients with cancer, highlighting our rationale for management and discussing the nuances of various cardiac imaging modalities.

Combined single-photon emission computed tomography-myocardial perfusion imaging with coronary calcium score for assessing coronary disease.

Coronary artery disease (CAD) underestimation represents a major pitfall of single-photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI). Coronary artery calcium score (CACS) has emerged as a sensitive tool for the assessment of suspect CAD; however, the integration of SPECT-MPI with CACS has been seldom evaluated, so far, and was therefore the aim of the present study. Patients undergoing SPECT-MPI with CACS and subsequent coronary angiography were included. ROC curves were used to identify the CACS values best predictive for CAD. In SPECT-MPI negative patients, the formula: defined the optimal CACS cut-points. The Systematic Coronary Risk Evaluation 2 was applied for 10-year cardiovascular risk estimation. Significant CAD was defined for an epicardial coronary stenosis >70 or 50% for the left main. Among 124 patients, 61 (49.19%) displayed positive SPECT-MPI, whereas 69 (56%) had significant CAD at angiography. Sensitivity, specificity, and positive predictive value (PPV) for SPECT-MPI were, respectively, 74, 82, and 84%. Considering 63 SPECT-MPI negative cases, the index values for CACS at the optimal cutoff value of 1949 were: sensitivity 28%, specificity 89%, and PPV 50%, allowing to further detect five (8%) of the patients with significant CAD. The increased discriminative power of the combined SPECT-MPI with CACS was not conditioned by the pretest cardiovascular risk. Among patients with suspect CAD undergoing SPECT-MPI, the addition of CACS in negative cases allows to detect a consistent further 8% of patients with significant CAD, thus limiting the risk of disease underestimation and offering potential prognostic benefits.

Development of 99mTc-Labeled Complexes with a Niraparib HYNIC Derivative for PARP-Positive Tumor Imaging.

As an enzyme that plays an important role in DNA repair, poly(ADP-ribose) polymerase-1 (PARP-1) has become a popular target for cancer therapy. Nuclear medicine molecular imaging technology, supplemented by radiolabeled PARP-1 inhibitors, can accurately determine the expression level of PARP-1 at lesion sites to help patients choose an appropriate treatment plan. In this work, niraparib was modified with a hydrazinonicotinamide (HYNIC) group to generate the ligand NPBHYNIC, which has an in vitro affinity (IC50) of 450.90 nM for PARP-1. The ligand NPBHYNIC was labeled with technetium-99m and six different coligands to yield [99mTc]Tc-(X/tricine)-NPBHYNIC (X = TPPTS, TPPMS, PSA, PDA, NIC and ISONIC). These complexes were hydrophilic and exhibited good stability in vitro, and low levels of these complexes were taken up by nontarget organs and tissues in Kunming mice. Among these complexes, [99mTc]Tc-(TPPTS/tricine)-NPBHYNIC and [99mTc]Tc-(NIC/tricine)-NPBHYNIC were selected for biodistribution in HeLa tumor-bearing BALB/c nude mice at 2 h post injection. The results revealed that the tumor uptake of [99mTc]Tc-(TPPTS/tricine)-NPBHYNIC (1.02 ± 0.07% ID/g) was greater than that of [99mTc]Tc-(NIC/tricine)-NPBHYNIC (0.36 ± 0.05% ID/g). Additionally, in biodistribution, single-photon emission computed tomography/computed tomography (SPECT/CT) and radioautography experiments, the tumor uptake of [99mTc]Tc-(TPPTS/tricine)-NPBHYNIC was significantly reduced in the blocked group, indicating PARP-1 specificity. Therefore, it has potential for use as a niraparib-based tumor imaging agent that targets PARP-1.

The complex role of cardiovascular imaging in viability testing.

Myocardial viability assessment is used to determine if chronically dysfunctional myocardium may benefit from coronary revascularization. Cardiac magnetic resonance with late gadolinium enhancement is the current gold standard for visualizing myocardial scar and provides valuable insight into myocardial viability. Viability assessments can also be made with Cardiac Positron Emission Tomography, Echocardiography, Single Photon Emission Tomography, and Cardiac Computed Tomography with each having advantages and disadvantages. Despite the classical interpretation that viability predicts segmental functional improvement, more recent studies have found that revascularization of viable myocardium has conflicting roles in predicting benefits for patients, especially as it relates to major adverse cardiovascular events, development of heart failure symptoms, and all-cause mortality. This review covers these conflicts along with an in-depth review of the pathophysiologic processes that are fundamental to myocardial viability and the various methods used for determining viability.

2025 Update Consensus of 99mTc-Pyrophosphate Scintigraphy in the Transthyretin Cardiac Amyloidosis from the Taiwan Society of Cardiology and the Society of Nuclear Medicine of the Republic of China.

This 2025 updated consensus outlines the diagnostic strategy for transthyretin amyloid cardiomyopathy (ATTR-CM). Given that ATTR-CM is a significant contributor to heart failure, this article emphasizes the importance of making an early and precise diagnosis, particularly as new therapeutic options become available. Highlighting the critical importance of an early and accurate diagnosis, particularly in light of emerging therapeutic modalities, this consensus underscores the central role of 99mTc-pyrophosphate (PYP) scintigraphy as a non-invasive diagnostic tool. The consensus calls for the adoption of standardized imaging protocols and interpretation criteria to ensure consistency and reliability across diverse clinical settings. The integration of qualitative and quantitative imaging techniques within a structured diagnostic framework places particular focus on the use of single-photon emission computed tomography/computed tomography (SPECT/CT) imaging to enhance diagnostic precision by minimizing blood pool activity and eliminating overlapping interference. Three-hour imaging is considered to be critical for accurate evaluations and to reduce false-positive findings, and it is recommended for its superior diagnostic accuracy. Moreover, quantitative assessments are also considered to be essential for evaluating myocardial amyloid deposition. This updated consensus provides comprehensive guidelines for clinicians, with the aim of optimizing patient outcomes through precise diagnosis and effective management of ATTR-CM. The consensus concludes by advocating for continued research and refinement of imaging methodologies, particularly to enhance the clinical applicability of 99mTc-PYP scintigraphy and other future developments in nuclear molecular imaging.

New type of lacunar stroke presenting in brain perfusion images: A case report

BACKGROUND A stroke is a significant brain event that impinges on individual motor or cognitive functions. In the lacunar stroke subtype of ischemic stroke, which results from blocked blood flow in certain brain areas, cases of dysarthria due to impaired blood flow are not uncommon. However, limited literature and research on the relevant pathophysiology and neural pathways exist. CASE SUMMARY We focus on a 60-year-old female with subacute stroke presenting symptoms including tongue deviation to the right, speech difficulty, choking on water, and biting the oral mucosa. She did not exhibit abnormalities in limb movement or sensation except for numbness in the tongue. We use single-photon emission computed tomography to reveal reduced blood flow in the left parietal lobe and bilateral temporal lobes. This report presents an atypical case of dysarthria, who exhibits abnormal articulation along with abnormal sensation and numbness in the tongue, prompting further investigation into the association between lacunar stroke subtypes, altered blood perfusion in affected brain regions, and neurological clinical status. CONCLUSION Dysarthria-plus syndrome in lacunar stroke isn’t solely related to motor function but also affects sensory function such as oral numbness.

Electrically Pumped h-BN Single-Photon Emission in van der Waals Heterostructure.

Atomic defects in solids offer a versatile basis to study and realize quantum phenomena and information science in various integrated systems. All-electrical pumping of single defects to create quantum light emission has been realized in several platforms including color centers in diamond and silicon carbide, which could lead to the circuit network of electrically triggered single-photon sources. However, a wide conduction channel which reduces the carrier injection per defect site has been a major obstacle. Here, we realize a device concept to construct electrically pumped single-photon emission using a van der Waals stacked structure with atomic plane precision. Defect-induced tunneling currents across graphene and NbSe2 electrodes sandwiching an atomically thin h-BN layer allow robust and persistent generation of nonclassical light from h-BN. The collected emission photon energies range between 1.4 and 2.9 eV, revealing the electrical excitation of a variety of atomic defects. By analyzing the dipole axis of observed emitters, we further confirm that emitters are crystallographic defect structures of h-BN crystal. Our work facilitates implementing efficient and miniaturized single-photon devices in van der Waals platforms toward applications in quantum optoelectronics.

Evaluation of long axial field-of-view (LAFOV) PET/CT for post-treatment dosimetry in Yttrium-90 radioembolization of liver tumors: a comparative study with conventional SPECT imaging.

Long axial field-of-view (LAFOV) positron emission tomography/computed tomography (PET/CT) scanners enable high sensitivity and wide anatomical coverage. Therefore, they seem ideal to perform post-selective internal radiation therapy (SIRT) 90Y scans, which are needed, to confirm that the dose is delivered to the tumors and that healthy organs are spared. However, it is unclear to what extent the use of LAFOV PET is feasible and which dosimetry approaches results in accurate measurements. In this retrospective analysis, a total number of 32 patients was included (median age 71, IQR 14), which had hepatocellular carcinoma, cholangiocarcinoma, or liver metastases. All patients underwent SIRT, and the post-therapy scan was acquired on a single photon emission computed tomography/computed tomography (SPECT/CT) and a LAFOV Biograph Quadra PET/CT with a 20-minute acquisition time. Post-treatment dosimetry, regarding the tumor, whole-liver and lung (LMD) absorbed dose was done using an organ-wise (Simplicit90Y) and a voxel-wise approach (HERMIA Dosimetry) which used a semi-Monte Carlo algorithm. The lung shunt fraction (LSF) was also measured using the voxel-wise approach and compared to the planned. The planning, post-treatment SPECT and PET (SPECTpre, SPECTpost, PETpost) median tumor doses based on the organ-wise dosimetry were 276.0Gy (200.0-330.0Gy), 232.0Gy (158.5-303.5Gy) and 267.5Gy (182.5-370.8Gy). In contrast, the median voxel-wise PETpost dose was significantly smaller than the planned SPECTpre (152.5Gy (94.8-223.8Gy); p < 0.00001). Moreover, the median tumor absorbed dose at 90% (D90) of the tumor volume was significantly higher in SPECTpost compared with PETpost (123.5Gy; 81.5-180.0 vs. 30.5Gy; 11.3-106.3; p < 0.00001). The PETpost measured LSF was significantly lower compared to the planned SPECTpre (0.89%; 0.4-1.3% vs. 2.3%; 1.5-3.6%; p < 0.0001). Similarly, the measured PETpost median LMD was considerably lower to the planned SPECTpre (1.2Gy; 0.6-2.3 vs. 2.5Gy; 1.4-4.7; p < 0.0001). LAFOV PET enabled the direct measurement of post therapy lung dose and tumor doses that correlated well with the planned treatment doses. However, current voxel-wise-based tumor dosimetry seems to be inaccurate for LAFOV PET. In addition, dose volume histogram-based metrics also significantly underestimate the delivered dose. Therefore, improved dosimetry tools are needed for reliable voxel-wise 90Y dosimetry to leverage the sensitivity and spatial resolution of LAFOV PET scanners.

Favorable seizure and developmental outcomes without preoperative intracranial electroencephalography in pediatric patients following epilepsy surgery: A single epilepsy center retrospective study.

At our institute, most pediatric patients undergo epilepsy surgery following a thorough presurgical evaluation without intracranial electroencephalography (EEG). We conducted an initial validation of our noninvasive presurgical strategy by assessing the seizure and developmental outcomes of 135 children. All 135 pediatric patients were <15 years old, had undergone curative surgery, and were followed for at least 2 years postoperatively. Presurgical evaluations and postoperative seizure and developmental outcomes were investigated. Thorough noninvasive evaluation included 3-T magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography (FDG-PET) in all patients. Intracranial EEG was mainly indicated for patients whose MRIs were negative or subtle. We defined Engel class I as favorable and Engel classes II-IV as unfavorable seizure outcomes. Intelligence quotient (IQ) and developmental quotient (DQ) before and 2 years after surgery were used to assess developmental/neuropsychological outcomes. MRI was positive in 130 of 135 patients (96.3%), including 39 of 40 with focal cortical dysplasia (FCD) type II and 30 of 33 with FCD type I. FDG-PET revealed concordant localizing findings in 119 of 132 patients (90.2%). Ictal single photon emission computed tomography provided concordant localizing information in 85 of 91 patients (93.4%). Intracranial EEG was performed in only 10 of 135 patients (7.4%). Ninety-seven of 135 patients (71.9%) were seizure-free 2 years after surgery. The final seizure-free rate was 99 of 135 (73.3%). Temporal lobe surgery predicted a favorable seizure outcome by multivariate analysis, whereas FCD type I and preoperative IQ/DQ < 70 predicted an unfavorable outcome. The mean IQ change was +1.3 points, and the mean DQ change was +1.0 points. Mean DQ significantly improved following extratemporal surgery (multivariate regression, p < .05), and mean DQ significantly decreased in patients with epileptic spasms (multivariate regression, p < .01). Thorough noninvasive presurgical evaluation enables detection of subtle MRI lesions and curative epilepsy surgery without intracranial EEG in most patients, including those with FCD type II and type I, and leads to favorable seizure and developmental/neuropsychological outcomes.

Exploring the Potential Imaging Biomarkers for Parkinson’s Disease Using Machine Learning Approach

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by motor and neuropsychiatric symptoms resulting from the loss of dopamine-producing neurons in the substantia nigra pars compacta (SNc). Dopamine transporter scan (DATSCAN), based on single-photon emission computed tomography (SPECT), is commonly used to evaluate the loss of dopaminergic neurons in the striatum. This study aims to identify a biomarker from DATSCAN images and develop a machine learning (ML) algorithm for PD diagnosis. Using 13 DATSCAN-derived parameters and patient handedness from 1309 individuals in the Parkinson’s Progression Markers Initiative (PPMI) database, we trained an AdaBoost classifier, achieving an accuracy of 98.88% and an area under the receiver operating characteristic (ROC) curve of 99.81%. To ensure interpretability, we applied the local interpretable model-agnostic explainer (LIME), identifying contralateral putamen SBR as the most predictive feature for distinguishing PD from healthy controls. By focusing on a single biomarker, our approach simplifies PD diagnosis, integrates seamlessly into clinical workflows, and provides interpretable, actionable insights. Although DATSCAN has limitations in detecting early-stage PD, our study demonstrates the potential of ML to enhance diagnostic precision, contributing to improved clinical decision-making and patient outcomes.

Diagnostic Efficacy of 123Iodo-Metaiodobenzylguanidine SPECT/CT in Cardiac vs. Neurological Diseases: A Comparative Study of Arrhythmogenic Right Ventricular Cardiomyopathy and α-Synucleinopathies.

Background/Objectives: 123Iodo-metaiodobenzylguanidine single photon emission computed tomography/computed tomography (123I-MIBG SPECT/CT) is used to evaluate the cardiac sympathetic nervous system in cardiac diseases such as arrhythmogenic right ventricular cardiomyopathy (ARVC) and α-synucleinopathies such as Parkinson's diseases. A common feature of these diseases is denervation. We aimed to compare quantitative and semi-quantitative cardiac sympathetic innervation using 123I-MIBG imaging of ARVC and α-synucleinopathies. Methods: Cardiac innervation was assessed using 123I-MIBG SPECT/CT in 20 patients diagnosed with definite ARVC and 8 patients with clinically diagnosed α-synucleinopathies. Heart-to-mediastinum-ratio (H/M-ratio), as semi-quantitative, was evaluated. Additionally, standardized uptake value (SUV), as quantitative, was measured as SUVmedian, SUVmax, and SUVpeak in the left ventricle (LV), the right ventricle (RV), and in the global heart, based on a CT scan following quantitative image reconstruction. Results: The quantification of 123I-MIBG uptake in the LV, the RV, and the global heart was feasible in patients suffering from α-synucleinopathies. SUVmedian, and SUVpeak demonstrated a significant difference between ARVC and α-synucleinopathies across all regions, with the α-synucleinopathy group showing a lower uptake. In addition, the H/M ratio showed significantly lower uptake in patients with α-synucleinopathies than in patients with ARVC. Conclusions: Patients with α-synucleinopathies demonstrate significantly lower cardiac innervation in semi-quantitative and quantitative examinations than ARVC patients. The comparison of semi-quantitative and quantitative examinations suggests that quantitative examination offers an advantage. Quantitative analysis can be performed separately for the LV, RV, and global heart. However, analyzing the LV or RV does not provide additional benefit over analyzing the global heart in distinguishing between α-synucleinopathies and ARVC. Considering the different clinical manifestations of these two diseases, the absolute SUV values should not be generalized across different pathologies, and disease-specific ranges should be used instead.

A new perspective on drug-resistant epilepsy in children with focal cortical dysplasia type 1: From challenge to favorable outcome.

We comprehensively characterized a large pediatric cohort with focal cortical dysplasia (FCD) type 1 to expand the phenotypic spectrum and to identify predictors of postsurgical outcomes. We included pediatric patients with histopathological diagnosis of isolated FCD type 1 and at least 1 year of postsurgical follow-up. We systematically reanalyzed clinical, electrophysiological, and radiological features. The results of this reanalysis served as independent variables for subsequent statistical analyses of outcome predictors. All children (N = 31) had drug-resistant epilepsy with varying impacts on neurodevelopment and cognition (presurgical intelligence quotient [IQ]/developmental quotient scores = 32-106). Low presurgical IQ was associated with abnormal slow background electroencephalographic (EEG) activity and disrupted sleep architecture. Scalp EEG showed predominantly multiregional and often bilateral epileptiform activity. Advanced epilepsy magnetic resonance imaging (MRI) protocols identified FCD-specific features in 74.2% of patients (23/31), 17 of whom were initially evaluated as MRI-negative. In six of eight MRI-negative cases, fluorodeoxyglucose-positron emission tomography (PET) and subtraction ictal single photon emission computed tomography coregistered to MRI helped localize the dysplastic cortex. Sixteen patients (51.6%) underwent invasive EEG. By the last follow-up (median = 5 years, interquartile range = 3.3-9 years), seizure freedom was achieved in 71% of patients (22/31), including seven of eight MRI-negative patients. Antiseizure medications were reduced in 21 patients, with complete withdrawal in six. Seizure outcome was predicted by a combination of the following descriptors: age at epilepsy onset, epilepsy duration, long-term invasive EEG, and specific MRI and PET findings. This study highlights the broad phenotypic spectrum of FCD type 1, which spans far beyond the narrow descriptions of previous studies. The applied multilayered presurgical approach helped localize the epileptogenic zone in many previously nonlesional cases, resulting in improved postsurgical seizure outcomes, which are more favorable than previously reported for FCD type 1 patients.

Development of 111In-Labeled Monoclonal Antibodies Targeting SFTSV Structural Proteins for Molecular Imaging of SFTS Infectious Diseases by SPECT.

No effective vaccines or treatments are currently available for severe fever with thrombocytopenia syndrome (SFTS), a fatal tick-borne infectious disease caused by the SFTS virus (SFTSV). This study evaluated the potential of 111In-labeled anti-SFTSV antibodies targeting SFTSV structural proteins as single-photon emission computed tomography (SPECT) imaging agents for the selective visualization of SFTSV-infected sites. This study used nuclear medicine imaging to elucidate the pathology of SFTS and assess its therapeutic efficacy. Immunostaining experiments confirmed that the anti-SFTSV antibody (N-mAb), which targets the N protein, specifically accumulated in SFTSV-infected Vero E6 cells. 111In-labeled N-mAb was successfully prepared using a diethylenetriaminepentaacetic acid (DTPA) chelator, resulting in [111In]In-DTPA-N-mAb with high radiochemical purity exceeding 95% and a radiochemical yield of 55%. Cell-binding assays using SFTSV-infected Vero E6 cells demonstrated that [111In]In-DTPA-N-mAb binding was detectable even without membrane permeabilization, with the binding intensity correlating with infection levels. In vivo studies using SFTSV-infected A129 mice showed high spleen accumulation of [111In]In-DTPA-N-mAb (87.5% ID/g), consistent with SFTSV tropism, compared to 12.3% ID/g in mock-infected mice. SPECT/CT imaging clearly revealed high radioactivity in these regions. Although nonspecific accumulation was noted in the liver and spleen, this issue may be mitigated through antibody modifications such as fragmentation or PEGylation. Overall, [111In]In-DTPA-N-mAb is a promising imaging agent for non-invasive visualization of SFTSV-infected sites and may aid in elucidating SFTS pathology and assessing therapeutic efficacy.

The value of semiquantitative analysis of [99mTc]MDP SPECT/CT in localizing responsible lesions for suspected fresh osteoporotic vertebral compression fractures in patients with contraindications to MRI.

The aim of this study was to evaluate the effectiveness of single-photon emission computed tomography/computed tomography (SPECT/CT) in detecting and localizing the causative vertebra in cases of suspected fresh osteoporotic vertebral compression fractures (OVCFs) in patients with contraindications to MRI. A total of 21 patients with severe back pain with 31 suspected OVCF segments and contraindications to MRI were initially identified through radiographs and the back pain-inducing test (BPIT). The responsible vertebral bodies were determined using [99mTc]MDP SPECT/CT before percutaneous vertebroplasty (PVP). Clinical outcomes and radiographic parameters, including basic demographics, injury duration, focal kyphosis (FK), loss of vertebral height (LVH), and relative intensity values (RIVs) for target and nontarget segments in the SPECT/CT were measured. SPECT/CT identified 14 old and 26 fresh OVCFs. Of these, 18 patients with 26 fresh OVCF segments underwent PVP, and achieved satisfactory outcomes. Significant differences were observed in the RIV, FK, and LVH values between the fresh and old OCVF groups (all p < 0.05). RIVs showed a significant negative correlation with injury duration (r = -0.57, p < 0.05), and a positive correlation with LVH (r = 0.43, p < 0.05). Multiple linear regression analysis confirmed that injury duration was an independent predictor of RIVs (p < 0.05). SPECT/CT is useful for detecting and differentiating fresh fractures from old fractures in patients having OVCF who cannot undergo MRI after BPIT validation, allowing these patients to achieve excellent clinical outcomes following PVP. The RIV serves as a valuable parameter for assessing the duration of fresh versus old OVCFs. ChiCTR, ChiCTR 2300077570. Retrospectively registered, http://www.chictr.org.cn/showproj.html?proj=206192.