Intraosseous hemangiomas are benign vascular lesions within osseous structures, often found incidentally in the spine. Their imaging appearance consists of a variable mixture of fat, vascular channels, and remodeled trabecular bone. Fat-rich lesions typically have characteristic findings, including but not limited to vertically-oriented trabeculae on radiographs, a "polka-dot" pattern on axial computed tomography (CT), a "corduroy" pattern on sagittal or coronal CT, and hyperintensities on both T1- and T2-weighted magnetic resonance imaging (MRI). Conversely, atypical lesions are lipid-poor and may be T1 hypointense and less conspicuous on CT. Imaging appearance may overlap with metastatic disease and other marrow-replacing processes. Aggressive hemangiomas represent an important clinical subset often characterized by osseous expansion, cortical disruption, and epidural or paravertebral extension, pathologic fracture, or neurologic compromise. In current practice, the evaluation of vertebral hemangiomas with nuclear medicine can be challenging due to highly variable and often non-specific radiotracer uptake. On technetium-99m (99mTc) bone scintigraphy, lesions are often inconspicuous, although decreased or increased uptake may occur. On fluorine-18 fluorodeoxyglucose (FDG) PET/CT, hemangiomas are usually non-avid or mildly avid, but occasional marked uptake should not be interpreted in isolation. Uptake on prostate-specific membrane antigen (PSMA)- and somatostatin receptor (SSTR)-targeted PET is similarly inconsistent. Regardless of the radiotracer used, correlation with prior imaging, particularly on CT and MRI, is more reliable than assessing radiotracer avidity alone. This review presents a practical multimodal framework for recognizing typical, atypical, and aggressive intraosseous hemangiomas in adult and pediatric presentations with common nuclear medicine interpretation pitfalls.
Acute medical conditions represent a significant and heterogeneous clinical burden, often requiring rapid and accurate diagnosis to guide timely management. Positron emission tomography/computed tomography (PET/CT), which integrates functional PET imaging with CT's anatomical detail, has expanded beyond its traditional oncologic applications and is being increasingly explored in acute or emergency settings. PET/CT, particularly with but not limited to 18F-fluorodeoxyglucose, represents a promising adjunct, offering unique pathophysiological insights that can complement conventional imaging, supporting diagnostic decision-making and patient management in select non-oncologic contexts. This review examines the evolving role of PET/CT in acute clinical scenarios, highlighting its ability to detect early metabolic or inflammatory changes that may precede structural abnormalities on conventional imaging modalities such as CT or MRI. It also highlights how further evidence is, nonetheless, still required to better define optimal clinical integration.
Positron Emission Tomography (PET) and Single-Photon Emission Computerized tomography (SPECT), pose unique challenges when considering pediatric patient populations. Because both modalities require prolonged acquisition times, often ranging from 20 min to over an hour, minimizing patient motion is critical to prevent motion-related image quality degradation and ensuring diagnostic accuracy. While pharmacological sedation may avoid both problems, it carries inherent clinical risks, operational bottlenecks and comes with increased healthcare costs to society. In this paper, we assess the role of evidence-based, non-pharmacological strategies chronologically across the pediatric patient’s journey in the nuclear medicine department. By combining pre-visit psychological preparation, camera familiarization, optimized intravenous (IV) cannulation protocols, tailored physical and modality-specific positioning, and positive aftercare reinforcement, the nuclear medicine staff can optimize diagnostic image quality while prioritizing pediatric patient comfort and safety.
“Death by neurologic criteria” (DNC), a condition previously described as “brain death”, accounts for approximately 21% of deaths in the pediatric intensive care unit (PICU). DNC is primarily a clinical assessment, defined by the irreversible cessation of all functions of the entire brain including the brainstem. When physical examination and apnea testing, the standard components of DNC assessment, cannot be completed in full, ancillary investigations are required to complement and complete the process. Amongst accepted ancillary tests, radionuclide perfusion studies exhibit some of the highest levels of accuracy in adult and pediatric populations and have been favored in recent clinical and imaging guidelines. The goal of this review is to discuss radionuclide perfusion studies performed as ancillary studies in the determination of DNC in children, highlighting recent research, physiologic differences in pediatric brain and skull development, and differences in performing and interpreting radionuclide ancillary studies in this population.
Fluorine-18 fluorodeoxyglucose ([18F] FDG) PET/CT has become central to the management of paediatric lymphoma, providing critical information for staging, response assessment, and treatment adaptation. Its integration into international clinical trials and treatment protocols has enabled response-adapted strategies that improve outcomes while reducing long-term toxicity, particularly through the selective omission of radiotherapy in early responders.Beyond its established clinical role, recent advances are expanding the capabilities of PET/CT. Quantitative biomarkers such as metabolic tumour volume (MTV) and total lesion glycolysis (TLG) offer more comprehensive assessment of disease burden than conventional metrics like SUVmax. Emerging applications in immunotherapy, including checkpoint inhibitors and CAR-T cell therapy, highlight the evolving role of PET in response prediction and treatment monitoring, although paediatric-specific data remain limited.Artificial intelligence and radiomics are introducing novel approaches for automated image analysis and risk stratification, while dose reduction strategies and hybrid imaging modalities such as PET/MRI aim to minimize radiation exposure in children. Additionally, the development of novel radiotracers, including proliferation and immune-targeted agents, may further refine disease characterization in the future.Despite these advances, significant challenges remain, particularly regarding standardization, validation, and translation into paediatric clinical practice. Continued collaborative research and harmonization efforts will be essential to ensure that technological innovations translate into meaningful improvements in outcomes for children with lymphoma.
Occult differentiated thyroid carcinoma may become clinically evident years after thyroidectomy performed for presumed benign multinodular goiter, presenting an important diagnostic challenge. Following CT-guided biopsy confirmation of metastatic differentiated thyroid carcinoma of thyroid follicular-cell origin, post-therapy ¹³¹I scintigraphy and SPECT/CT demonstrated multifocal iodine-avid pulmonary metastases and defined the functional extent of disease. These images illustrate the complementary value of post-therapy radioiodine imaging in characterizing iodine avidity and metastatic disease distribution.
Neuroblastoma is the most common extracranial solid malignancy of childhood and accounts for approximately 15% of pediatric cancer-related mortality. Originating from neural crest-derived sympathetic nervous system cells, neuroblastoma demonstrates remarkable biological heterogeneity, ranging from spontaneous regression to highly aggressive metastatic disease. Accurate imaging is fundamental to diagnosis, staging, risk stratification, treatment planning, response assessment, and surveillance. Over the past four decades, molecular imaging of neuroblastoma has evolved substantially, progressing from conventional metaiodobenzylguanidine (MIBG) scintigraphy to advanced positron emission tomography/computed tomography (PET/CT) tracers that provide complementary biological and molecular information. This review explores the evolution of neuroblastoma imaging, highlighting the strengths, limitations, and emerging roles of established and novel radiopharmaceuticals. 131/123I-MIBG scintigraphy remains the cornerstone of functional imaging in neuroblastoma because of its high specificity for tumors expressing the norepinephrine transporter. MIBG imaging has become integral to the International Neuroblastoma Risk Group (INRG) staging system and is widely utilized for evaluating primary tumors, metastatic disease, and therapeutic response. Furthermore, MIBG serves as a theranostic agent, enabling targeted radionuclide therapy with 131I-MIBG in patients with relapsed or refractory disease. However, approximately 5-10% of neuroblastomas demonstrate absent or low MIBG avidity, limiting its diagnostic utility. Additionally, MIBG imaging is constrained by lower spatial resolution, prolonged imaging protocols, and reduced sensitivity for small lesions compared with modern PET techniques. The increasing availability of PET/CT has led to the development of several promising tracers that address these limitations. 18F-fluorodeoxyglucose (18F-FDG) PET/CT has emerged as an important alternative, particularly in MIBG-negative tumors, dedifferentiated disease, and high-risk neuroblastoma. FDG uptake often correlates with tumor aggressiveness and adverse biological features, providing valuable prognostic information. Beyond FDG, tracers targeting specific aspects of neuroblastoma biology have demonstrated significant potential. 18F-fluorodihydroxyphenylalanine (18F FDOPA) PET/CT exploits catecholamine biosynthesis pathways and has shown superior sensitivity for detecting both primary and metastatic lesions. Somatostatin receptor imaging with 68Ga-DOTA-peptides offers opportunities for patient selection for peptide receptor radionuclide therapy.As novel theranostic paradigms emerge, molecular imaging is increasingly serving not only as a diagnostic tool but also as a means of guiding targeted therapies and monitoring treatment efficacy. This review provides a comprehensive overview of contemporary neuroblastoma imaging, tracing the transition from MIBG-based scintigraphy to advanced PET tracers and emerging theranostic approaches. Understanding the complementary roles of these imaging modalities is essential for optimizing patient management and improving outcomes in children with this complex and heterogeneous malignancy.
BACKGROUND:Single Photon Emission Computed Tomography (SPECT) is a cornerstone of functional nuclear medicine imaging, traditionally providing static three-dimensional representations of radiotracer distribution. The emergence of 4D SPECT has introduced the temporal dimension to SPECT, enabling the quantification of physiological parameters such as perfusion, uptake, and clearance rates. This systematic review aims to synthesize current evidence on dynamic SPECT principles, clinical applications and perspectives across major organ systems. METHODS:A systematic literature review was conducted according to the PRISMA guidelines. The PubMed database was searched over a 30-year period up to 2026 using "dynamic" and "SPECT," supplemented by specific searches in cardiac imaging including "SPECT" and "myocardial blood flow." All references were imported into the Rayyan web platform for duplicate removal and structured screening. Of the 1,029 studies initially identified, 807 were excluded. The remaining 222 studies were assessed in full text to identify relevant works addressing dynamic SPECT acquisition, reconstruction methods, and clinical applications. RESULTS:Dynamic SPECT has been explored in several domains, primarily cardiology and nephrology. Cardiac dynamic SPECT enables absolute myocardial blood flow quantification comparable to PET, while renal applications allow the assessment of cortical function and excretory dynamics. Advances in cadmium-zinc-telluride (CZT) detector technology, reconstruction algorithms, and motion-compensated acquisitions have been key to improving temporal and spatial resolution. CONCLUSIONS:Dynamic SPECT/CT represents a major evolution toward quantitative nuclear imaging, bridging the gap between traditional static SPECT and PET kinetics. Continued technological refinement and standardization are essential to establish its role in routine clinical practice.
FDG-PET/CT in a 73-year-old man revealed incidental FDG accumulation in the left testicle which was eventually diagnosed as an inflammatory myofibroblastic tumor (IMT): a rare localization of a rare tumor. Previous reports describe moderate to high FDG uptake in IMT but a localization in the testis on FDG-PET has not been described before. Although IMTs are often benign, they can affect nearby tissues and, in rare cases, spread to distant organs. FDG-PET can be used to guide therapy, with surgery being the preferred treatment, and to detect recurrent disease or to evaluate response to systemic treatment.
Pediatric nuclear medicine plays an essential role in the diagnosis and treatment of a wide range of oncologic and non-oncologic diseases while requiring particular attention to radiation safety because of children's greater radiosensitivity, ongoing growth, and longer life expectancy. Over the past decade, substantial advances in quantitative imaging, detector technology, hybrid imaging, computational dosimetry, and theranostics have transformed radiation management from standardized activity administration toward increasingly individualized approaches. This review summarizes the biological basis of radiation risk in children, fundamental principles of internal dosimetry, and the unique anatomical and physiological factors influencing radiation dose estimation in pediatric patients. Current international recommendations for pediatric administered activities are discussed alongside practical strategies for radiation dose optimization across common nuclear medicine procedures and hybrid PET/CT and SPECT/CT imaging. The review further examines the growing role of quantitative PET and SPECT, patient-specific dosimetry, voxel-based dose calculation, Monte Carlo simulation, and advanced computational phantoms in improving absorbed-dose estimation and supporting personalized imaging and radionuclide therapy. Emerging applications of artificial intelligence, including image reconstruction, automated organ segmentation, predictive dosimetry, and low-count imaging, are also highlighted. Finally, current challenges, radiation protection principles, and future directions are discussed, emphasizing the transition toward precision pediatric nuclear medicine. Continued technological innovation, standardized quantitative methodologies, and prospective pediatric validation studies will be essential to optimize radiation safety while maximizing the diagnostic and therapeutic benefits of molecular imaging and theranostics in children.
Pediatric gastrointestinal scintigraphy provides physiologic, quantitative, and clinically useful information for children with suspected motility disorders, feeding intolerance, reflux or aspiration, refractory constipation, and complex postsurgical anatomy. This review summarizes the role of esophageal transit scintigraphy, gastric emptying and gastroesophageal reflux scintigraphy, and small-bowel and colonic transit scintigraphy in children. These studies complement anatomic imaging, endoscopy, pH-impedance testing, and manometry by directly evaluating the movement of radiolabeled meals or boluses under relatively physiologic conditions.For each application, the review emphasizes practical patient preparation, meal and radiopharmaceutical selection, acquisition methods, quantitative analysis, interpretation patterns, reporting elements, and common pitfalls. Suggested pediatric protocols are provided in three tables, and representative examples are illustrated as figures. Because pediatric normative data are limited for several gastrointestinal transit applications, results should be interpreted in the context of patient age, symptoms, meal type, position, medication status, prior surgery, and institutional methodology. A structured and clinically oriented approach can improve the diagnostic value of pediatric gastrointestinal scintigraphy and help guide multidisciplinary management.
Background: Equine nuclear medicine provides functional information on bone turnover, perfusion, inflammation and tracer biodistribution. Its role has evolved from planar scintigraphy toward SPECT, PET and quantitative imaging. This review synthesised the historical foundations and contemporary state of equine nuclear medicine, with emphasis on racehorse and performance-horse applications.Methods: A PRISMA-aligned systematic narrative review and evidence map were undertaken. MEDLINE via PubMed, Web of Science Core Collection and SciQuest were searched, supplemented by reference-list screening, forward citation searching and snowballing. Eligible records addressed nuclear medicine imaging, radiopharmaceutical use, technical methods, diagnostic or therapeutic applications, dosimetry, radiation safety or facility/workflow considerations in horses. Heterogeneity in populations, indications, modalities and outcomes precluded meta-analysis; records were therefore mapped descriptively and synthesised narratively.Results: After consolidation and deduplication, 181 records were retained. Historical and foundational approaches accounted for 138 records, spanning non-skeletal applications, technical factors, musculoskeletal interpretation, lameness localisation and stress injury in performance / racehorses. This literature established scintigraphy as a tool for detecting altered skeletal turnover, localising occult or complex lameness and identifying stress remodelling or prodromal injury, while emphasising clinical correlation, normal-pattern recognition and technical standardisation. Contemporary approaches accounted for 43 records and included scintigraphic optimisation, quantitation, AI/radiomics, contemporary scintigraphy, SPECT and PET. These studies demonstrated refinement of planar scintigraphy, emerging standing SPECT for complex axial regions, and growth of standing 18F-NaF and 18F-FDG PET for distal-limb imaging, lesion monitoring and multimodality assessment.Conclusions: Equine nuclear medicine has progressed from planar localisation toward a complementary functional imaging discipline. Scintigraphy remains useful for broad screening, SPECT is under-developed but promising for pelvis, vertebral column and head applications, and PET is the leading contemporary advance for high-resolution distal-limb imaging, quantitation and performance-horse injury prevention.
Worldwide, Nuclear Medicine is seeing a phenomenal growth in terms of an increasing number of PET-CT scanners being installed, incorporation of routine nuclear medicine procedures in more internationally accepted guidelines as well as advances in the development of more specific radiopharmaceuticals to enable precision guided individualised therapies. In this review, we focus on the increasing role for Nuclear Medicine in the management of paediatric cancers. Since traditional nuclear medicine specialists may have limited awareness and knowledge of paediatric cancers, we have covered this complex topic in the order of frequency of incidence and have provided brief salient points about each cancer and existing management pathways before focusing on the role of Nuclear Medicine. In the final section, we briefly cover some Theranostics related developments on the horizon.
Artificial intelligence (AI) has emerged as a potential enabling technology for lower-dose paediatric PET/CT, but its value depends on whether dose reduction can be achieved without compromising diagnostic accuracy, lesion detectability, quantitative reliability or clinical confidence. This review examines AI-enabled pathways for paediatric PET/CT dose optimisation, including low-count PET denoising, image enhancement, full-count synthesis, reconstruction-integrated AI, low-dose CT reconstruction, synthetic CT, CT-free attenuation/scatter correction, motion correction, automated quality control, patient-specific protocol selection and reduction of unnecessary or repeat imaging. The strongest direct opportunities are low-count PET enhancement and AI-supported CT dose reduction, while synthetic CT and CT-free correction may reduce or eliminate attenuation-correction CT in selected settings where diagnostic CT is not required. Indirect AI approaches, including motion-risk reduction, quality-control systems and agentic workflow support, may reduce dose by improving first-time-right imaging, avoiding repeat acquisition and matching protocols to the clinical question. It is important to differentiate between visually aesthetic images and diagnostic images, in other words, visual image improvement is an inadequate endpoint. AI-enhanced lower-dose PET/CT must be validated for small-lesion detection, quantitative accuracy, response-classification stability, scanner and tracer generalisability, failure modes and prospective clinical safety. Social, ethical and legal considerations are also central, because AI tools have the potential to widen disparities. AI may make paediatric PET/CT lower dose, but only when it preserves clinical value within a governed, paediatric-specific optimisation framework.
18F- Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) has become an indispensable imaging modality in the evaluation of paediatric malignancies as well selected infectious and inflammatory disorders. However, the interpretation of paediatric PET/CT is often challenging because of age-dependent physiological tracer distribution, developmental changes, therapy-related alterations and technical artifacts that can mimic disease. Familiarity with normal variants and potential pitfalls specifically seen in paediatric imaging, together with careful corelation of PET findings with CT morphology and clinical history, is essential for accurate image interpretation. This review summarizes the spectrum of physiological FDG uptake patterns, common interpretative pitfalls and practical strategies to improve diagnostic confidence and avoid unnecessary repeat investigations in paediatric PET/CT imaging.
Accurate gross tumor volume (GTV) delineation remains a critical yet error-prone step in radiotherapy (RT) planning. Conventional imaging and [¹⁸F]FDG PET/CT are limited by poor tumor-to-background contrast and non-specific inflammatory uptake. 18F/68Ga-labeled fibroblast activation protein inhibitor (FAPI) PET, which targets cancer-associated fibroblasts (CAFs) within the tumor microenvironment, offers a biologically distinct and potentially superior alternative. This review summarizes the current evidence across multiple solid tumors, highlighting its potential to improve gross tumor volume delineation, refine staging, and reduce interobserver variability compared with conventional imaging and [¹⁸F]FDG PET. Although FAPI PET frequently altered target volumes and RT planning, the available evidence is limited by small, predominantly retrospective studies and the absence of histopathological validation or long-term clinical outcomes. At present, FAPI PET should be considered a complementary imaging tool with particular value in selected clinical settings. Prospective multicenter studies are needed to establish standardized segmentation methods and determine whether improved target delineation translates into better patient outcomes.
Cardiovascular diseases (CVDs) remain among the leading causes of both health and economic burdens worldwide. Myocardial Perfusion Imaging (MPI) performed using Single Photon Emission Computed Tomography (SPECT) or, more recently, Positron Emission Tomography (PET), has long served as a cornerstone in the diagnosis and management of coronary heart disease (CHD). However, rising healthcare costs and rapidly advancing imaging technologies have prompted re-evaluation of nuclear cardiology’s cost-effectiveness, making careful selection of imaging modalities essential. In this review, an economic evaluation of imaging in CHD has been undertaken, summarizing the most relevant studies on the cost-effectiveness of various imaging modalities. The heterogeneity in data - largely related to institutional resources, operator expertise, clinical setting (inpatient vs. outpatient), healthcare system, and reimbursement structure - does not yet allow definitive conclusions on the cost-effectiveness of each individual modality. Therefore, a well-structured multimodality imaging approach appears to provide greater diagnostic and economic value, offering both improved clinical outcomes and more efficient resource utilization.
PURPOSE:This systematic review and meta-analysis aims to evaluate the diagnostic accuracy of FDG PET/CT for diagnosing pleural mesothelioma in treatment-naïve patients using histopathology as reference standard. Secondary aims include evaluation of FDG PET/CT or FDG PET/MRI's diagnostic accuracy of lymph node and distant metastases, their impact on TNM-staging, and PET uptake and volumetric parameters in pleural mesothelioma. METHODS:We conducted a systematic review and meta-analysis adhering to 'Preferred Reporting Guidelines for Systematic reviews and Meta-Analyses' (PRISMA) with a predefined literature search. It consisted of the terms: "pleura" or "pleural" or "mesothelioma", "PET" or "positron emission tomography", and "FDG" or "fluorodeoxyglucose". Two independent reviewers systematically screened the literature based on eligibility criteria, extracted data, and evaluated quality of evidence. The meta-analysis was performed using a hierarchical model to estimate pooled diagnostic accuracy parameters. Publication bias was assessed with Deeks' regression test. RESULTS:Forty-one studies were included; the primary aim was evaluated by a meta-analysis which included 10 studies. Thirty-eight studies were included for evaluating secondary aims. The estimated pooled sensitivity and specificity for FDG PET/CT in differentiating pleural mesothelioma from benign pleural lesions were 0.94 (95%CI: 0.87-0.97) and 0.84 (95%CI: 0.73-0.91), respectively. There was substantial study heterogeneity, but no publication bias was detected. CONCLUSION:This study shows high sensitivity and specificity of FDG PET/CT for diagnosing pleural mesothelioma. The results are compatible with previous findings and give an updated evidence base to compare diagnostic performance of FDG PET/CT to other imaging modalities e.g. contrast-enhanced CT or PET with novel tracers.
Purpose: To review clinical evidence on somatostatin receptor (SSTR) targeted imaging and SSTR directed radioligand therapy in neuroendocrine prostate cancer (NEPC).Methods: A PRISMA guided search of PubMed, Scopus, and Web of Science was performed on September 14, 2025. Two reviewers screened studies and extracted data. Risk of bias was appraised using Joanna Briggs Institute tools. Synthesis was descriptive.Results: Of 1937 records, 41 studies were included (4 prospective cohorts and 37 case reports or series). Case reports or series reported 80 patients with SSTR imaging. Cohort studies used 111In based SSTR scintigraphy (three cohorts) or 68Ga-DOTATATE PET/CT (one cohort) and reported SSTR uptake in a minority of patients with heterogeneity across metastatic sites. In patient level reports, SSTR imaging was positive in 61/80 cases (76.3%). Common tracers were 68Ga-DOTATATE (27/80), 68Ga-DOTANOC (17/80), 111In-octreotide or 111In-pentetreotide (14/80), and 18F-AlF-NOTA-octreotide (10/80). PSMA imaging was available in 27 cases; SSTR uptake was present in 11/14 PSMA negative cases. Ten patients in nine reports received SSTR directed PRRT, most often 177Lu-DOTATATE, with symptom benefit and imaging and/or biomarker improvement frequently described; toxicity reporting was limited.Conclusion: SSTR expression in NEPC is heterogeneous. SSTR imaging can support phenotyping and selection for SSTR directed therapy in selected patients, including PSMA low disease, but prospective validation with standardized reporting is needed.
