Search

Background: Granulomatosis with polyangiitis (GPA) is characterised by granulomatous inflammation and small-to-medium vessel necrotising vasculitis, mainly affecting respiratory tract and kidneys. Renal involvement presenting as tumour-like lesions poses diagnostic and treatment challenges. Methods: Following the observation of a GPA patient presenting with multiple renal tumour-like lesions, we conducted a systematic literature review on MEDLINE/PubMed, EMBASE, and Cochrane databases. Data gathered from the literature were analysed to summarise the diagnostic approach, management, and outcome of renal GPA-related tumour-like lesions. Results: a 49-year-old female presented with persistent constitutional symptoms and multiple bilateral renal lesions. Renal biopsy showed chronic interstitial inflammation with necrotising granulomas. Laboratory tests disclosed positive anti-proteinase 3 (PR3) anti-neutrophil cytoplasmic antibody (ANCA) leading to a final diagnosis of GPA. She was effectively treated with high-dose glucocorticoids and rituximab. Literature search yielded 41 articles, concerning 42 GPA patients with renal masses, presenting bilaterally in 23.8% of the cases. Positive PR3-ANCA was observed in 86.5% of the cases. Half of 42 patients showed kidney abnormalities. Treatment with glucocorticoids (83.3%) and immunosuppressive agents (80.9%) resulted in an overall good remission rate and favourable prognosis. Conclusions: GPA should be considered in the differential diagnoses of kidney tumour-like lesions. The diagnosis is challenging, and histological examination greatly contributes to the diagnostic work-up. [ABSTRACT FROM AUTHOR]

Unruptured brain arteriovenous malformations (AVMs) represent a complex disease in young healthy adults. Most often AVMs are clinically silent but also can display a neurologic syndrome due to hypoperfusion/hypometabolism in perilesional brain tissue called steal phenomenon. A 34-year-old woman was admitted to a secondary neurologic center complaining of a right hemiparesis and secondarily generalized seizures. Computed tomography scan and magnetic resonance imaging of the brain showed a left prerolandic AVM without signs of acute or previous bleedings. Digital subtraction angiography confirmed a left juxta-central AVM, with a diffuse pattern, fed by hypertrophic rolandic branches from the left middle cerebral artery. An 18F-fluorodeoxyglucose positron emission tomography-magnetic resonance imaging scan was performed 3 days after the critical episode. A significant hypometabolism in parenchymal regions ipsilaterally to the AVM was detected. Two embolization sessions were performed by means of N-butyl cyanoacrylate glue. At the end of the second procedure, a decrease of the shunt-flow and AVM size was observed. Six months later, 18F-fluorodeoxyglucose positron emission tomography-magnetic resonance imaging scan showed persistent hypometabolism located in the AVM area, with a significant improvement of the cortical hemispheric hypometabolism. The patient was asymptomatic and was sent to stereotactic radiosurgery to complete the treatment. In clinical practice, irritative symptoms in patients with unruptured AVMs could lead to erroneous evaluations. In case of fluctuating clinical syndromes, like our case, establishing that symptoms are related to a steal phenomenon is usually difficult. [ABSTRACT FROM AUTHOR]

Owing to the frequent observation of poverty of movements, facial hypomimia and balance impairment, amyotrophic lateral sclerosis (ALS) variant with predominance of upper motor neuron involvement (UMN-ALS) is prone to be diagnosed with Parkinsonism. A clinical assessment, including the velocity-dependent stretch response test to differentiate between pyramidal and extrapyramidal stiffness; the Unified Parkinson's Disease Rating Scale and the Berg Balance Scale to assess degree of bradykinesia and postural instability; and 123I-FP-CIT scintigraphy evaluation to investigate the nigrostriatal circuit involvement, were carried out to characterize Parkinson-like features in UMN-ALS patients. Sixteen UMN-ALS patients were included in the study. The velocity-dependent stretch response indicated spasticity in all the muscles tested. The degree of stiffness was found to be related to bradykinesia and postural instability. Eleven patients (70%) showed a reduction in striatal 123I-FP-CIT uptake found to be related to disease duration and patients' ages but not to scores of the functional scales. Slowness of movements and postural instability noted in our patients could be mostly attributed to spasticity. The lack of any correlation between UPDRS or BBS scores and the degree of nigrostriatal impairment on DaTSCAN seems to disprove nigrostriatal circuit involvement in these extrapyramidal-like features. [ABSTRACT FROM AUTHOR]

Background: Hemiplegic migraine (HM) is a rare variety of migraine with aura, characterized by motor deficits during the aura, often beginning in childhood. The hemiplegic attacks can be severe and prolonged but the prognosis is usually good. Data on neuroimaging, including diffusion-weighted imaging (DWI) and spectroscopy, during prolonged attacks of HM are quite limited, particularly in children.Case: An eight-year-old female had a prolonged attack of sporadic HM characterized by right-sided hemiplegia, global aphasia, fever and impairment of consciousness. MRI nine hours after hemiplegia onset was negative, while the following MRI scans (days 4 and 11) documented a progressive increase in cortical swelling in the left hemisphere with mild hyperintensity on DWI and mild reduction of apparent diffusion coefficient values. Proton MRI spectroscopy (MRS) (day 15) showed a decrease in the N-acetylaspartate/creatine ratio in the left hemisphere. 99mTc-ECD single-photon emission tomography (SPET) (day 27) showed marked left hemispheric hypoperfusion. The patient recovered completely after 40 days and neuroimaging follow-up (MRI and SPET) after six months was normal. The patient carried a missense mutation of the ATP1A2 gene.Conclusion: Multimodal neuroimaging (MRI, DWI, MRS, SPET) in a prolonged HM attack supports evidence for a primary neuronal dysfunction. [ABSTRACT FROM PUBLISHER]

To analyze multimodal three-dimensional medical images, interpolation is required for resampling which—unavoidably—introduces an interpolation error. In this work we describe the interpolation method used for imaging and neuroimaging and we characterize the Gibbs effect occurring when using such methods. In the experimental section we consider three segmented three-dimensional images resampled with three different neuroimaging software tools for comparing undersampling and oversampling strategies and to identify where the oversampling error lies. The experimental results indicate that undersampling to the lowest image size is advantageous in terms of mean value per segment errors and that the oversampling error is larger where the gradient is steeper, showing a Gibbs effect. [ABSTRACT FROM AUTHOR]

The article discusses the use of positron emission tomography (PET) in the diagnosis and management of functional pituitary neuroendocrine tumors (PitNETs). PitNETs are common intracranial tumors that can cause significant health issues. While magnetic resonance imaging (MRI) is the primary diagnostic method, it has limitations in detecting certain types of PitNETs. PET imaging with radiolabeled amino acids, such as [11C]MET and [18F]FET, shows promise in accurately detecting and localizing functional PitNETs. However, further research and larger studies are needed to determine the accuracy and clinical indications of PET imaging in this context. [Extracted from the article]

Epilepsy is one of the most frequent neurological conditions with an estimated prevalence of more than 50 million people worldwide and an annual incidence of two million. Although pharmacotherapy with anti-seizure medication (ASM) is the treatment of choice, ~30% of patients with epilepsy do not respond to ASM and become drug resistant. Focal epilepsy is the most frequent form of epilepsy. In patients with drug-resistant focal epilepsy, epilepsy surgery is a treatment option depending on the localisation of the seizure focus for seizure relief or seizure freedom with consecutive improvement in quality of life. Beside examinations such as scalp video/electroencephalography (EEG) telemetry, structural, and functional magnetic resonance imaging (MRI), which are primary standard tools for the diagnostic work-up and therapy management of epilepsy patients, molecular neuroimaging using different radiopharmaceuticals with single-photon emission computed tomography (SPECT) and positron emission tomography (PET) influences and impacts on therapy decisions. To date, there are no literature-based praxis recommendations for the use of Nuclear Medicine (NM) imaging procedures in epilepsy. The aims of these guidelines are to assist in understanding the role and challenges of radiotracer imaging for epilepsy; to provide practical information for performing different molecular imaging procedures for epilepsy; and to provide an algorithm for selecting the most appropriate imaging procedures in specific clinical situations based on current literature. These guidelines are written and authorized by the European Association of Nuclear Medicine (EANM) to promote optimal epilepsy imaging, especially in the presurgical setting in children, adolescents, and adults with focal epilepsy. They will assist NM healthcare professionals and also specialists such as Neurologists, Neurophysiologists, Neurosurgeons, Psychiatrists, Psychologists, and others involved in epilepsy management in the detection and interpretation of epileptic seizure onset zone (SOZ) for further treatment decision. The information provided should be applied according to local laws and regulations as well as the availability of various radiopharmaceuticals and imaging modalities. [ABSTRACT FROM AUTHOR]

Late-onset primary psychiatric disease (PPD) and behavioral frontotemporal dementia (bvFTD) present with a similar frontal lobe syndrome. We compare brain glucose metabolism in bvFTD and late-onset PPD and investigate the metabolic correlates of cognitive and behavioral disturbances through FDG-PET/MRI. We studied 37 bvFTD and 20 late-onset PPD with a mean clinical follow-up of three years. At baseline evaluation, metabolism of the dorsolateral, ventrolateral, orbitofrontal regions and caudate could classify the patients with a diagnostic accuracy of 91% (95% CI: 0.81–0.98%). 45% of PPD showed low-grade hypometabolism in the anterior cingulate and/or parietal regions. Frontal lobe metabolism was normal in 32% of genetic bvFTD and bvFTD with motor neuron signs. Hypometabolism of the frontal and caudate regions could help in distinguishing bvFTD from PPD, except in cases with motor neuron signs and/or genetic bvFTD for which brain metabolism may be less informative. • Frontal lobe syndrome is shared by late-onset primary psychiatric disease and bvFTD. • Brain glucose metabolism may be mostly useful in the differential diagnosis. • Frontal cortex/caudate metabolism guided a correct classification in 91% of cases. • Sparing of frontal metabolism may be present in bvFTD with MND or genetic bvFTD. • Hypometabolism of parietal cortex may be present in psychiatric diseases. [ABSTRACT FROM AUTHOR]

The article discusses the perspectives of the European Association of Nuclear Medicine on the role of artificial intelligence (AI) in molecular brain imaging. The authors highlight the potential of AI in advancing research and clinical practice in the field of molecular brain imaging. They emphasize the need for standardization of clinical brain image recording and imaging protocols, as well as the importance of annotated images and additional data for feeding AI algorithms. The article also explores the applications of AI in image acquisition, segmentation and registration, interpretability analysis, and specific clinical areas such as epilepsy, neurodegenerative and movement disorders, neuro-oncology, and psychiatric disorders. The authors acknowledge the challenges and limitations in implementing AI in these areas, including the need for large datasets, validation studies, and harmonization of AI algorithms. Overall, the article provides a comprehensive overview of the current state and future potential of AI in molecular brain imaging. [Extracted from the article]

Background: Molecular imaging is pivotal in staging and response assessment of children with neuroblastoma (NB). [123I]-metaiodobenzylguanidine (mIBG) is the standard imaging method; however, it is characterised by low spatial resolution, time-consuming acquisition procedures and difficult interpretation. Many PET catecholaminergic radiotracers have been proposed as a replacement for [123I]-mIBG, however they have not yet made it into clinical practice. We aimed to review the available literature comparing head-to-head [123I]-mIBG with the most common PET catecholaminergic radiopharmaceuticals. Methods: We searched the PubMed database for studies performing a head-to-head comparison between [123I]-mIBG and PET radiopharmaceuticals including meta-hydroxyephedrine ([11C]C-HED), 18F-18F-3,4-dihydroxyphenylalanine ([18F]DOPA) [124I]mIBG and Meta-[18F]fluorobenzylguanidine ([18F]mFBG). Review articles, preclinical studies, small case series (< 5 subjects), case reports, and articles not in English were excluded. From each study, the following characteristics were extracted: bibliographic information, technical parameters, and the sensitivity of the procedure according to a patient-based analysis (PBA) and a lesion-based analysis (LBA). Results: Ten studies were selected: two regarding [11C]C-HED, four [18F]DOPA, one [124I]mIBG, and three [18F]mFBG. These studies included 181 patients (range 5–46). For the PBA, the superiority of the PET method was reported in two out of ten studies (both using [18F]DOPA). For LBA, PET detected significantly more lesions than scintigraphy in seven out of ten studies. Conclusions: PET/CT using catecholaminergic tracers shows superior diagnostic performance than mIBG scintigraphy. However, it is still unknown if such superiority can influence clinical decision-making. Nonetheless, the PET examination appears promising for clinical practice as it offers faster image acquisition, less need for sedation, and a single-day examination. [ABSTRACT FROM AUTHOR]

The European Journal of Nuclear Medicine & Molecular Imaging has published a position paper on the use of theranostics in brain tumors. Theranostics, which involves using diagnostic imaging to identify specific molecular targets and then delivering targeted therapy, has shown promise in thyroid diseases, neuroendocrine tumors, and prostate cancer. The paper discusses the potential of theranostics in treating brain tumors, including meningiomas, gliomas, brain metastases, and pediatric brain tumors. It highlights the challenges in delivering therapeutics to the brain due to the blood-brain barrier and calls for further research and clinical trials to evaluate the efficacy of theranostic approaches in neuro-oncology. [Extracted from the article]

A nuclear emergency is a type of accident that can expose a highly variable number of people to isotopes and radiation [[1]]. It can take time to identify radionuclides deposited in the environment and to measure the dose adsorbed by a given individual (which decides the need for specific treatments), but treatments must be started promptly to avoid target organ contamination and deposition. The radionuclides absorbed by the thyroid could lead to thyroid dysfunction and thyroid cancer. [Extracted from the article]

Background: The myocardial uptake of bone-seeking tracers suspicious for transthyretin cardiac amyloidosis (ATTR-CA) can be incidentally detected in patients undergoing bone scintigraphy for noncardiac reasons. We conducted a systematic review and meta-analysis to assess the prevalence of these scintigraphic findings. Methods: A comprehensive literature search was performed using two bibliographic databases (PubMed/MEDLINE and Cochrane Library), searching for articles related to the review question. Eligible articles were selected, and relevant data were extracted by two authors. The pooled prevalence of incidental findings suspicious for ATTR-CA among patients undergoing bone scintigraphy was calculated on a per-patient-based analysis using a random-effects model. The pooled measure was provided with 95% confidence interval (95% CI) values. Results: Among 219 records, 11 articles were selected for the systematic review and 10 for the meta-analysis. The pooled prevalence of incidental findings suspicious for ATTR-CA was 1.1% (95% CI: 0.7–1.4%) with heterogeneity due to the characteristics of the included studies, patients, and index tests. These findings are more prevalent in older men. Conclusions: The prevalence of incidental findings of ATTR-CA among patients undergoing bone scintigraphy is low but not negligible. Nuclear medicine physicians should suggest, in the scintigraphic report, further clinical investigations when these findings are detected. Prospective studies are warranted. [ABSTRACT FROM AUTHOR]

Background: The pathological processes underlying cognitive impairment in Parkinson's disease (PD) are heterogeneous and the contribution of cerebral amyloid deposits is poorly defined, particularly in the early stages of the disease.Objective: To investigate regional [18F]florbetaben binding to amyloid-β (Aβ) and its contribution to cognitive dysfunction in early stage PD.Methods: A multicenter cohort of 48 PD patients from the Parkinson's Progression Marker Initiative (PPMI) underwent [18F]florbetaben positron emission tomography (PET) scanning. Clinical features, including demographic characteristics, motor severity, cerebrospinal fluid (CSF), and cognitive testing were systematically assessed according to the PPMI study protocol. For the purpose of this study, we analyzed various neuropsychological tests assessing all cognitive functions.Results: There were 10/48 (21%) amyloid positive PD patients (PDAβ+). Increased [18F]florbetaben uptake in widespread cortical and subcortical regions was associated with poorer performance on global cognition, as assessed by Montreal Cognitive Assessment (MoCA), and impaired performance on Symbol Digit Modality test (SDMT). Further, we found that PDAβ+ patients had higher CSF total-tau/Aβ1 - 42 (p = 0.001) and phosphorylated-tau/Aβ1 - 42 in (p = 0.002) compared to amyloid-negative PD.Conclusion: These findings suggest that multiple disease processes are associated with PD cognitive impairment and amyloid deposits may be observed already in early stages. However, prevalence of amyloid positivity is in the range of literature age-matched control population. Increased cortical and subcortical amyloid is associated with poor performance in attentive-executive domains while cognitive deficits at MoCA and SDMT may identify amyloid-related dysfunction in early PD. [ABSTRACT FROM AUTHOR]

Colorectal cancer is the third most common malignancy worldwide, and rectal cancer (RC) accounts for 29% of all cases. Local staging of RC is crucial for the purposes of addressing patients appropriately to surgery alone or to preoperative chemoradiotherapy (pCRT) followed by total mesorectal excision (TME). Combined pCRT and TME may negatively affect rectal function, so rectum-sparing approaches such as transanal local excision have been proposed as an alternative to TME for patients showing a major or complete clinical response on restaging after pCRT. Magnetic resonance imaging (MRI) has a fundamental role in the local staging and restaging of RC, with or without positron emission tomography (PET). PET/MRI enables a multiplanar high-resolution morphological study of the pelvis, providing important information on cell density and metabolic activity with diffusion-weighted imaging (DWI) and 18 F fluorodeoxyglucose uptake respectively. This article offers a pictorial review of the MRI anatomy of the ano-rectal region and an update on local RC staging with a hybrid 18 F-FDG PET/MRI scan. [ABSTRACT FROM AUTHOR]

The ankle and foot have numerous bones and complex joints that can be affected by several types of inflammatory arthritis with different patterns and various radiologic signs, depending on the phase of the disease. Involvement of these joints is most frequently seen in peripheral spondyloarthritis and rheumatoid arthritis in adults and juvenile idiopathic arthritis in children. Although radiographs are a mainstay in the diagnostic process, ultrasonography and especially magnetic resonance imaging allow early diagnosis and are crucial diagnostic tools. Some diseases have typical features based on target populations (e.g., adults versus children, men versus women), but others may have overlapping imaging characteristics. We highlight key diagnostic features and describe appropriate investigations to guide clinicians toward the correct diagnosis and provide support during disease monitoring. [ABSTRACT FROM AUTHOR]

Resting state fMRI has been used in many studies to investigate the impact of brain tumours on functional connectivity (FC). However, these studies have so far assumed that FC is stationary, disregarding the fact that the brain fluctuates over dynamic states. Here we utilised resting state fMRI data from 33 patients with high-grade gliomas and 33 healthy controls to examine the dynamic interplay between resting-state networks and to gain insights into the impact of brain tumours on functional dynamics. By employing Hidden Markov Models, we demonstrated that functional dynamics persist even in the presence of a high-grade glioma, and that patients exhibited a global decrease of connections strength, as well as of network segregation. Furthermore, through a multivariate analysis, we demonstrated that patients' cognitive scores are highly predictive of pathological dynamics, thus supporting our hypothesis that functional dynamics could serve as valuable biomarkers for better understanding the traits of high-grade gliomas. [ABSTRACT FROM AUTHOR]

Although brain amyloidosis was detected with CSF biomarker, a diagnosis of co-morbid Alzheimer disease was excluded due to negative biomarkers of amyloid-related neurodegeneration. In fact, the diagnosis of probable bvFTD requires functional imaging in cases where brain CT/MRI does not reveal atrophic changes in frontal and/or temporal lobes [[7]]. 1[ 18 F]FDG-PET/MRI of the brain of the patient detailing mild hypometabolism in the bilateral fronto-mesial cortex and involvement of the caudate nucleus bilaterally, which appears hypometabolic compared to the putamen. [Extracted from the article]

Hodgkin's lymphoma (HL) is one of the neoplasms with the best prognosis in children, adolescents and young adults, but sufferers are burdened by the possibility of developing adverse effects such as Bone Ischemic Lesions (BILs) which are lesions of the bone caused by the loss of/reduction in blood flow. The main goal of this retrospective study was to evaluate the role of [18F]FDG-PET-MR in the early detection of BILs in a single-center cohort of uniformly treated pediatric HL patients. BILs were assessed through PET-MR images as the appearance of medullary lesion surrounded by a serpiginous, tortuous border. From 2017 to 2022, 10/53 (18.9%) HL patients developed BILs which were mostly (8/10 patients) multifocal. Overall, 30 lesions were identified in the 10 asymptomatic patients, all with the above-mentioned features at MR and with very low [18F]FDG uptake. BILs were incidentally detected during HL therapy (n = 6) and follow-up (n = 4), especially in the long bones (66.7%). No factors correlated with the occurrence of BIL were identified. No patients developed complications. PET-MR is a sensitive combined-imaging technique for detecting BILs that are asymptomatic and self-limiting micro-ischemic lesions. BILs can be monitored by clinical follow-up alone both during and after therapy. [ABSTRACT FROM AUTHOR]

Certainly, availability of PET/MRI device is limited to few centers, in addition, this imaging technique is burdened by longer imaging acquisition time and higher costs with respect to PET/CT or WB-DWI-MRI. Therefore, patients achieving both PET/CT and WB-DWI-MRI negativity after treatment showed improved PFS as compared to patients with residual disease by PET or MRI [[9]]. Regarding baseline PET/MRI evaluation, FLs were detected in 23 patients, with mean SUVmax of 4.4 ± 2.78 and mean ADC of 963 ± 264.6 mm SP 2 sp /s. At the end of treatment PET/MRI showed a PET negativity (DS <= 3) in 23/27 (85.2%) patients, a MRI negativity (RAC = 1) in 18/27 (66.7%) cases and a concomitant PET and MRI negativity (DS <= 3 and RAC = 1) in 18/27 (66.7%) cases. [Extracted from the article]

Gliomas are amongst the most common primary brain tumours in adults and are often associated with poor prognosis. Understanding the extent of white matter (WM) which is affected outside the tumoral lesion may be of paramount importance to explain cognitive deficits and the clinical progression of the disease. To this end, we explored both direct (i.e., tractography based) and indirect (i.e., atlas-based) approaches to quantifying WM structural disconnections in a cohort of 44 high- and low-grade glioma patients. While these methodologies have recently gained popularity in the context of stroke and other pathologies, to our knowledge, this is the first time they are applied in patients with brain tumours. More specifically, in this work, we present a quantitative comparison of the disconnection maps provided by the two methodologies by applying well-known metrics of spatial similarity, extension, and correlation. Given the important role the oedematous tissue plays in the physiopathology of tumours, we performed these analyses both by including and excluding it in the definition of the tumoral lesion. This was done to investigate possible differences determined by this choice. We found that direct and indirect approaches offer two distinct pictures of structural disconnections in patients affected by brain gliomas, presenting key differences in several regions of the brain. Following the outcomes of our analysis, we eventually discuss the strengths and pitfalls of these two approaches when applied in this critical field. [ABSTRACT FROM AUTHOR]

The article focuses on the Food and Drug Administration approval of lecanemab an anti-Aβ drug for the treatment of Alzheimer's disease. Topics include the efficacy and consistent evidence of lecanemab in reducing amyloid burden and slowing cognitive decline, as well as the implications of its approval for the use of amyloid Positron emission tomography in Europe.

Purpose: To date, there is no consensus on how to semi-quantitatively assess brain amyloid PET. Some approaches use late acquisition alone (e.g., ELBA, based on radiomic features), others integrate the early scan (e.g., TDr, which targets the area of maximum perfusion) and structural imaging (e.g., WMR, that compares kinetic behaviour of white and grey matter, or SI based on the kinetic characteristics of the grey matter alone). In this study SUVr, ELBA, TDr, WMR, and SI were compared. The latter — the most complete one — provided the reference measure for amyloid burden allowing to assess the efficacy and feasibility in clinical setting of the other approaches. Methods: We used data from 85 patients (aged 44–87) who underwent dual time-point PET/MRI acquisitions. The correlations with SI were computed and the methods compared with the visual assessment. Assuming SUVr, ELBA, TDr, and WMR to be independent measures, we linearly combined them to obtain more robust indices. Finally, we investigated possible associations between each quantifier and age in amyloid-negative patients. Results: Each quantifier exhibited excellent agreement with visual assessment and strong correlation with SI (average AUC = 0.99, ρ = 0.91). Exceptions to this were observed for subcortical regions with ELBA and WMR (ρELBA = 0.44, ρWMR = 0.70). The linear combinations showed better performances than the individual methods. Significant associations were observed between TDr, WMR, SI, and age in amyloid-negative patients (p < 0.05). Conclusion: Among the other methods, TDr came closest to the reference with less implementation complexity. Moreover, this study suggests that combining independent approaches gives better results than the individual procedure, so efforts should focus on multi-classifier systems for amyloid PET. Finally, the ability of techniques integrating blood perfusion to depict age-related variations in amyloid load in amyloid-negative subjects demonstrates the goodness of the estimate. [ABSTRACT FROM AUTHOR]

The purpose of this narrative review was to assess the use of nanoparticles (NPs) to deliver radionuclides to targets, focusing on systems that have been tested in pre-clinical and, when available, clinical settings. A literature search was conducted in PubMed and Web of Science databases using the following terms: "radionuclides" AND "liposomes" or "PLGA nanoparticles" or "gold nanoparticles" or "iron oxide nanoparticles" or "silica nanoparticles" or "micelles" or "dendrimers". No filters were applied, apart from a minimum limit of 10 patients enrolled for clinical studies. Data from some significant studies from pre-clinical and clinical settings were retrieved, and we briefly describe the information available. All the selected seven classes of nanoparticles were highly tested in clinical trials, but they all present many drawbacks. Liposomes are the only ones that have been tested for clinical applications, though they have never been commercialized. In conclusion, the application of NPs for imaging has been the object of much interest over the years, albeit mainly in pre-clinical settings. Thus, we think that, based on the current state, radiolabeled NPs must be investigated longer before finding their place in nuclear medicine. [ABSTRACT FROM AUTHOR]

Aim. The present study aimed to assess the existing data about Primary Adrenal Lymphoma (PAL) evaluated with FDG PET and to describe a small monocentric series of cases. A systematic analysis (from 2010 to 2022) was made by using PubMed and Web of Science databases reporting data about the role of FDG PET/CT in patients with suspicious or known adrenal lymphoma. The quality of the papers was assessed by using QUADAS-2 criteria. Moreover, from a single institutional collection between 2010 and 2021, data from patients affected by adrenal lymphoma and undergoing contrast-enhanced compute tomography (ceCT)/magnetic resonance (MR) and FDG PET/CT or PET/MR were retrieved and singularly described. Seventy-eight papers were available from PubMed and 25 from Web of Science. Forty-seven (Nr. 47) Patients were studied, most of them in the initial staging of disease (n = 42; 90%). Only in one paper, the scan was made before and after therapy. The selected clinical cases were relative to the initial staging of disease, the restaging, and the evaluation of response to therapy. PET/CT and PET/MR always showed a high FDG uptake in the primary adrenal lesions and in metastatic sites. Moreover, PET metrics, such as maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV), were elevated in all primary adrenal lesions. In conclusions, FDG PET either coupled with CT or MRI can be useful in staging, restaging, and for the evaluation of treatment response in patients affected by PAL [ABSTRACT FROM AUTHOR]

Although the hypometabolic long COVID brain profile described above seems consistent with hypotheses and findings obtained for other viruses before the COVID-19 outbreak, with symptoms reported by patients with long COVID, and with results obtained from other diagnostic approaches assessing long COVID, the significance of these metabolic abnormalities in the individual patients remains to be determined. 2 Axial slices of a brain FDG PET scan of a patient with a hypometabolic long COVID pattern (A) and in a patient with a normal brain scan (B). Here, in 143 patients diagnosed in accordance with the current WHO definition of post-COVID syndrome, a hypometabolic long COVID pattern was observed in 47% of patients presenting persistent symptoms at an average of 10.9 months after COVID-19 [[28]]. [Extracted from the article]

The article focuses on advancing the biological definitions of Parkinson's disease (PD) and dementia with Lewy bodies (DLB) through novel biomarker-driven frameworks like SyNeurGe and NSD-ISS, analogous to the ATN system in Alzheimer's disease. Topics include the integration of α-synucleinopathy detection using seed amplification assays in cerebrospinal fluid and skin, alongside neurodegeneration and dopaminergic deficit assessments via imaging biomarkers.

Secondly, although the radiotracer activity used by Soinio et al. was presumably similar to that used by O'Shea et al. and Burton et al., the PET images acquisition protocol differed markedly. Published by Bioscientifica Ltd. Printed in Great Britain © 2021 European Society of Endocrinology https://eje.bioscientifica.com https://doi.org/10.1530/EJE-20-1402 European Journal of Endocrinology 184:3 L9-L10 F Crimì and others Imaging by 11 C-metomidate PET Functional imaging by 11 C-metomidate PET: a really useless technique for primary aldosteronism subtyping?. [Extracted from the article]

Pelvic-ureteric junction obstruction (PUJO) is rare in adults and may be seen when the diagnosis has been missed in childhood. Hypertension may be a feature of PUJO but limited data are currently available in literature to support its association. We report a case of a 29-year-old woman who presented with severe hypertension. Work-up to exclude secondary hypertension showed high plasma renin activity, and imaging by ultrasound and computerized tomography a hydronephrosis and PUJO with impairment of kidney drainage at the renal scintigraphy. After double-J ureteric stenting, blood pressure decreased, antihypertensive medication tapered and the patients was normotensive with no antihypertensive medications after 6 months. We provide an update of the pathophysiology of hypertension in PUJO and a review of the available literature in order better to define the available treatments for these patients. [ABSTRACT FROM AUTHOR]

The present procedural guidelines summarize the current views of the EANM Neuro-Imaging Committee (NIC). The purpose of these guidelines is to assist nuclear medicine practitioners in making recommendations, performing, interpreting, and reporting results of [18F]FDG-PET imaging of the brain. The aim is to help achieve a high-quality standard of [18F]FDG brain imaging and to further increase the diagnostic impact of this technique in neurological, neurosurgical, and psychiatric practice. The present document replaces a former version of the guidelines that have been published in 2009. These new guidelines include an update in the light of advances in PET technology such as the introduction of digital PET and hybrid PET/MR systems, advances in individual PET semiquantitative analysis, and current broadening clinical indications (e.g., for encephalitis and brain lymphoma). Further insight has also become available about hyperglycemia effects in patients who undergo brain [18F]FDG-PET. Accordingly, the patient preparation procedure has been updated. Finally, most typical brain patterns of metabolic changes are summarized for neurodegenerative diseases. The present guidelines are specifically intended to present information related to the European practice. The information provided should be taken in the context of local conditions and regulations. [ABSTRACT FROM AUTHOR]

The use of regorafenib in recurrent glioblastoma patients has been recently approved by the Italian Medicines Agency (AIFA) and added to the National Comprehensive Cancer Network (NCCN) 2020 guidelines as a preferred regimen. Given its complex effects at the molecular level, the most appropriate imaging tools to assess early response to treatment is still a matter of debate. Diffusion-weighted imaging and O-(2-18F-fluoroethyl)-L-tyrosine positron emission tomography ([18F]FET PET) are promising methodologies providing additional information to the currently used RANO criteria. The aim of this study was to evaluate the variations in diffusion-weighted imaging/apparent diffusion coefficient (ADC) and [18F]FET PET-derived parameters in patients who underwent PET/MR at both baseline and after starting regorafenib. We retrospectively reviewed 16 consecutive GBM patients who underwent [18F]FET PET/MR before and after two cycles of regorafenib. Patients were sorted into stable (SD) or progressive disease (PD) categories in accordance with RANO criteria. We were also able to analyze four SD patients who underwent a third PET/MR after another four cycles of regorafenib. [18F]FET uptake greater than 1.6 times the mean background activity was used to define an area to be superimposed on an ADC map at baseline and after treatment. Several metrics were then derived and compared. Log-rank test was applied for overall survival analysis. Percentage difference in FET volumes correlates with the corresponding percentage difference in ADC (R = 0.54). Patients with a twofold increase in FET after regorafenib showed a significantly higher increase in ADC pathological volume than the remaining subjects (p = 0.0023). Kaplan–Meier analysis, performed to compare the performance in overall survival prediction, revealed that the percentage variations of FET- and ADC-derived metrics performed at least as well as RANO criteria (p = 0.02, p = 0.024 and p = 0.04 respectively) and in some cases even better. TBR Max and TBR mean are not able to accurately predict overall survival. In recurrent glioblastoma patients treated with regorafenib, [18F]FET and ADC metrics, are able to predict overall survival and being obtained from completely different measures as compared to RANO, could serve as semi-quantitative independent biomarkers of response to treatment. Simultaneous evaluation of [18F]FET and ADC metrics using PET/MR allows an early and reliable identification of response to treatment and predict overall survival. [ABSTRACT FROM AUTHOR]

The use of amyloid PET imaging as surrogate outcome measure of the effect of anti-AD drugs is a more complex matter and has been less explored. This article is part of the Topical Collection on Neurology On June 7th, 2021, for the first time since 2003, a novel drug against Alzheimer's disease (AD), aducanumab (Aduhelm™), has been approved in the USA by the Food and Drug Administration (FDA). We will focus here on two main aspects directly concerning our clinical and research practice: (1) using amyloid PET imaging as eligibility criterion and anticipating the associated needs, and (2) evaluating amyloid PET readout changes as surrogate outcome measures in clinical trials. SUVr is a biased measure for assessment of reduction of amyloid load after a pharmacotherapeutic intervention, as it shows a "reduction" in amyloid load over time in AD patients that in fact is an artefact linked with the perfusion reduction in cortical areas that occurs in AD patients over time [[24]]. [Extracted from the article]

Objectives: The aims of the study were (i) to examine the PCa detection rate of 18F-choline (FCH) PET/MRI and (ii) to assess the impact of PET/MRI findings in patients with PCa who develop OMD using PSA response as a biomarker. Methods: We retrospectively analyzed a cohort of 103 patients undergoing FCH PET/MRI for biochemical recurrence of PCa. The inclusion criteria were (1) previous radical prostatectomy (RP) with or without adjuvant radiotherapy (RT); (2) PSA levels available at the time of PET; (3) OMD, defined as a maximum of 5 lesions on PET/MRI; and (4) follow-up data available for at least 6 months after PET. All images were reviewed by two nuclear medicine physicians and interpreted with the support of two radiologists. Results: Seventy patients were eligible for the study: 52 patients had a positive FCH PET/MRI and 18 had a negative scan. The overall PCa detection rates for MRI, PET, and PET/MRI were 65.7%, 37.1%, and 74.3%, respectively. Thirty-five patients were treated with radiotherapy (RT), 16 received hormonal therapy (HT), 3 had a combined therapy (RT + HT), and 16 (23%) underwent PSA surveillance. At follow-up, PSA levels decreased in 51 patients (73%), most of whom had been treated with RT or RT + HT. Therapeutic management was guided by PET/MRI in 74% of patients, which performed better than MRI alone (68% of patients). Conclusion: FCH PET/MRI has a higher detection rate than MRI or PET alone for PCa patients with OMD and PSA levels > 0.5 ng/mL, prompting a better choice of treatment. [ABSTRACT FROM AUTHOR]

Objectives: To test the performance of a 3D convolutional neural network (CNN) in analysing brain [18F]DOPA PET/CT in order to identify patients with nigro-striatal neurodegeneration. We evaluated the robustness of the 3D CNN by testing it against a manual regional analysis of the striata by using a striatal-to-occipital ratio (SOR). Methods: We analyzed patients who had undergone [18F]DOPA PET/CT from 2016 to 2018. Two examiners interpreted PET/CT images as positive or negative. Only patients with at least 2 years of follow-up and an ascertained neurological diagnosis were included. A 3D CNN was developed to evaluate [18F]DOPA PET/CT and refine the diagnosis of movement disorder. This system required training and testing, which were carried out on 2/3 and 1/3 of patients, respectively. A regional analysis was also conducted by drawing region of interest on T1-weighted 3D MRI scans, on which the [18F]DOPA PET images were first co-registered. Results: Ninety-eight patients were enrolled: 43 presented nigro-striatal degeneration and 55 negative cases used as controls. After training on 69 patients, the diagnostic performance of the 3D CNN was then calculated in 29 patients. Sensitivity, specificity, negative predictive value, positive predictive value and accuracy were 100%, 89%, 100%, 85% and 93%, respectively. When we compared the 3D CNN results with the SOR analysis, we found that the two patients falsely classified as positive by the 3D CNN procedure showed SOR values ≤ 5th percentile of the negative cases' distribution. Conclusions: 3D CNNs are able to interpret [18F]DOPA PET/CT properly, revealing patients affected by Parkinson's disease. Key Points: •[18F]DOPA PET/CT is a sensitive diagnostic tool to identify patients with nigro-striatal neurodegeneration. • A semiquantitative evaluation of the images allows a more confident interpretation of the PET findings. • 3D convolutional neural network allows an accurate interpretation of 18F-DOPA PET/CT images, revealing patients affected by Parkinson's disease. [ABSTRACT FROM AUTHOR]

28680132 5 Gonzalez-Gay MA, Vazquez-Rodriguez TR, Gomez-Acebo I. Strokes at time of disease diagnosis in a series of 287 patients with biopsy-proven giant cell arteritis. References 1 González-Gay MA, García-Porrúa C, Llorca J. Visual manifestations of giant cell arteritis: trends and clinical spectrum in 161 patients. [Extracted from the article]

Purposes: We present the first in-human brain PET imaging data of the new α4β2 nicotinic acetylcholine receptor (nAChR)–targeting radioligand (+)-[18F]Flubatine. Aims were to develop a kinetic modeling-based approach to quantify (+)-[18F]Flubatine and compare the data of healthy controls (HCs) and patients with Alzheimer's disease (AD); to investigate the partial volume effect (PVE) on regional (+)-[18F]Flubatine binding; and whether (+)-[18F]Flubatine binding and cognitive test data respective β-amyloid radiotracer accumulation were correlated. Methods: We examined 11 HCs and 9 mild AD patients. All subjects underwent neuropsychological testing and [11C]PiB PET/MRI examination. (+)-[18F]Flubatine PET data were evaluated using full kinetic modeling and regional as well as voxel-based analyses. Results: With 270-min p.i., the unchanged parent compound amounted to 97 ± 2%. Adequate fits of the time-activity curves were obtained with the 1 tissue compartment model (1TCM). (+)-[18F]Flubatine distribution volume (binding) was significantly reduced in bilateral mesial temporal cortex in AD patients compared with HCs (right 10.6 ± 1.1 vs 11.6 ± 1.4, p = 0.049; left 11.0 ± 1.1 vs 12.2 ± 1.8, p = 0.046; one-sided t tests each). PVE correction increased not only (+)-[18F]Flubatine binding of approximately 15% but also standard deviation of 0.4–70%. Cognitive test data and (+)-[18F]Flubatine binding were significantly correlated in the left anterior cingulate, right posterior cingulate, and right parietal cortex (r > 0.5, p < 0.05 each). In AD patients, (+)-[18F]Flubatine binding and [11C]PiB standardized uptake value ratios were negatively correlated in several regions; whereas in HCs, a positive correlation between cortical (+)-[18F]Flubatine binding and [11C]PiB accumulation in the white matter was found. No adverse event related to (+)-[18F]Flubatine occurred. Conclusion: (+)-[18F]Flubatine is a safe and stable PET ligand. Full kinetic modeling can be realized by 1TCM without metabolite correction. (+)-[18F]Flubatine binding affinity was high enough to detect group differences. Of interest, correlation between white matter β-amyloid PET uptake and (+)-[18F]Flubatine binding indicated an association between white matter integrity and availability of α4β2 nAChRs. Overall, (+)-[18F]Flubatine showed favorable characteristics and has therefore the potential to serve as α4β2 nAChR–targeting PET ligand in further clinical trials. [ABSTRACT FROM AUTHOR]

Aim: In recent years, the clinical availability of scanners for integrated positron emission tomography (PET) and magnetic resonance imaging (MRI) has enabled the practical potential of multimodal, combined metabolic-receptor, anatomical, and functional imaging to be explored. The present systematic review and meta-analysis summarize the diagnostic information provided by PET/MRI in patients with prostate cancer (PCa). Materials and methods: A literature search was conducted in three different databases. The terms used were "choline" or "prostate-specific membrane antigen - PSMA" AND "prostate cancer" or "prostate" AND "PET/MRI" or "PET MRI" or "PET-MRI" or "positron emission tomography/magnetic resonance imaging." All relevant records identified were combined, and the full texts were retrieved. Reports were excluded if (1) they did not consider hybrid PET/MRI; or (2) the sample size was < 10 patients; or (3) the raw data were not enough to enable the completion of a 2 × 2 contingency table. Results: Fifty articles were eligible for systematic review, and 23 for meta-analysis. The pooled data concerned 2104 patients. Initial disease staging was the main indication for PET/MRI in 24 studies. Radiolabeled PSMA was the tracer most frequently used. In primary tumors, the pooled sensitivity for the patient-based analysis was 94.9%. At restaging, the pooled detection rate was 80.9% and was higher for radiolabeled PSMA than for choline (81.8% and 77.3%, respectively). Conclusions: PET/MRI proved highly sensitive in detecting primary PCa, with a high detection rate for recurrent disease, particularly when radiolabeled PSMA was used. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Cognitive improvement after cranioplasty: A possible volume transmission-related effect," published in previous issue.

The aim of the present review was to assess the role of combined 18F-Fluorodeoxyglucose (F-18 FDG) and Ga-68 DOTA-peptides positron emission tomography (PET)-computed tomography (CT) in neuroendocrine tumors (NETs). We have searched MEDLINE databases, including PubMed and Scopus, for studies about the combined FDG and Ga-68 DOTA-peptides PET-CT or PET/Magnetic Resonance Imaging (MRI) in NETs in the last 15 years (from 2004 to November 2019). No limits were applied to the search strategy. Abstracts, reviews, letters to editors, and editorials were excluded. Seven studies met the inclusion criteria. In total 236 patients received both 68Ga-DOTA-peptides and F-18 FDG PET-CT for the characterization of NETs. In particular, 84 patients had a neuroendocrine lung tumor while the others mainly a gastroenteropancreatic NET. The combined use of F-18 FDG and Ga-68 DOTA-peptides (mainly TOC) PET studies provides complementary information regarding different biological characteristics of the lesions, thus enabling a more accurate selection of patients for targeted radionuclide therapy and a better stratification of the prognosis. Ga-68 DOTA-peptides and F-18 FDG PET should be considered complementary in patients with NETs. They should be both performed in the initial staging and during follow-up, with a specific selection of patients and in a multidisciplinary vision. • Ga-68 DOTA-peptides and F-18 FDG PET-CT should be both performed in patients with neuroendocrine tumors. • Ga-68 DOTA-peptides uptake is higher in low-grade NETs, while F-18 FDG PET-CT uptake is high in G2 and G3 NETs. • F-18 FDG should be performed in case of negative or slightly positive Ga-68 DOTA-peptides PET-CT for identification of dedifferentiation status. [ABSTRACT FROM AUTHOR]

We here report on a case of CD with epileptic seizures and progressive hyperkinetic movement disorder and discuss neuroimaging findings with brain [ SP 18 sp F]FDG-PET/MRI study. Neurological manifestations of CD include epileptic seizures, cerebellar ataxia, and movement disorders such as myoclonus, dystonia, chorea, and parkinsonism [[2]]. The findings from this case report suggest that etiology of the progressive complex hyperkinetic syndrome characterized by stimulus-sensitive myoclonus associated with dystonia and gait ataxia might be sustained by a CD-related autoimmune process. [Extracted from the article]

The authors propose to abandon amyloid imaging and they base this statement primarily on the fact that amyloid imaging is not able to provide the full histopathological picture of AD (amyloid plaques & tau aggregates & neurodegeneration). This presence (regardless of whether amyloid aggregates cause the disease) is what is visualized by amyloid imaging in vivo to support the clinical AD diagnosis, no more, no less. The presence of amyloid pathology clearly is diagnostic, as it is required for the current gold standard neuropathological diagnosis of AD, and amyloid imaging verifiably provides this information in vivo. For amyloid imaging, the development level for the respective recommendations which can be found in the joint publication by the Society of Nuclear Medicine and Molecular Imaging and the Alzheimer's Association on the Appropriate Use Criteria for Amyloid PET [[13]] is relatively high (in relation to that of other imaging procedures). [Extracted from the article]

Aim Of the Study: Skeletal muscle metastases (SMM) are a rare entity, mainly detected at autopsy. Nevertheless, radiological and nuclear medicine imaging can contribute to the diagnosis with a significant impact on the treatment and prognosis of neoplastic patients. This study aimed to systematically review the features of SMM at imaging considering the primary tumors and the sites of occurrence.Materials and Methods: We conducted a systematic search of three electronic database (i.e., PubMed, Science Direct, and Web of Science) up to May 2019, without any language or time interval restriction. Two reviewers performed the search and selection process, data extraction, and synthesis. We resolved disagreements by consensus and/or involving a third reviewer. The included studies have been classified according to the Oxford Centre for Evidence Based Medicine (CEBM) grading system.Results: Out of 8598 and 1077 articles respectively for radiological and hybrid imaging, 29 papers were included. According to CEBM, twelve were level 4. Computed tomography (CT) is mainly applied and, despite the existence of CT and magnetic resonance-based classifications, these are rarely used. Positron emission tomography/CT allowed the detection of small and subtle lesion also in the extremities. Muscles of the trunk were mostly affected and mainly respiratory tumors are associated with this type of metastatic spread.Conclusion: Radiological and hybrid imaging allow a precise characterization of SMM. However, a more systematic approach, including also the application of available classification systems, may increase the diagnostic accuracy for this rare type of metastases.Key Points: • Skeletal muscle metastases have heterogeneous characteristics at imaging but mostly abscess-like features and high metabolic activity are described. • Skeletal muscle metastases mainly affect the muscles of the trunk. • Pulmonary, urological, and gastrointestinal cancers are the most frequent cause of skeletal muscle metastases. [ABSTRACT FROM AUTHOR]

Behavioral and cognitive variables predicting behavioral frontotemporal dementia (bvFTD) versus primary psychiatric disorders mimicking bvFTD (phenocopy syndrome: bvFTD-PS) were studied. Forty-one probable/definite bvFTD and 16 bvFTD-PS patients were evaluated with cognitive battery, Neuropsychiatric Inventory, and Stereotypic and Ritualistic Behavior-revised questionnaires. Twenty-seven healthy subjects served as control. Severity of cognitive impairment/behavioral symptoms and profile of cognitive deficits were similar, with bvFTD-PS showing impaired executive abilities and memory. However, phonemic fluency was impaired only in bvFTD (p < 0.001). Depression was worse in bvFTD-PS, while apathy, disinhibition, and dietary changes characterized bvFTD. Phonemic fluency and depression accounted for the best predictive diagnostic model. A structured psychiatric screening of bvFTD mimickers may often yield a psychiatric diagnosis with predominant depressive symptoms and therefore a potentially treatable condition. [ABSTRACT FROM AUTHOR]

Chest pain is experienced by patients with cardiac amyloidosis (CA), but a systematic investigation of its frequency, underlying etiologies and clinical significance is lacking. Clinical, echocardiographic, laboratory characteristics, available coronary arteries imaging and endomyocardial biopsy (EMB) findings of 174 patients with CA (n = 104 with transthyretin, ATTR; n = 70 with light chains, AL) were analyzed. Chest pain was reported in 66 (38%) CA patients. Compared to those without, patients with chest pain had more frequently a history of coronary artery disease (CAD) (27% vs 15%, p = 0.048) and heart failure (HF) symptoms (62% vs 43%, p = 0.015), higher high sensitivity troponin I (hs-cTnI, 101 vs 65 ng/L, p = 0.032) and higher brain natriuretic peptide (597 vs 407 ng/L, p = 0.024). Among CA patients with chest pain undergoing coronary arteries imaging (n = 37), obstructive CAD was detected in 14 (38%), 13 of whom with ATTR-CA. Of these 37 patients, EMB was available in 10 and vascular/perivascular amyloid deposition was detected in 4/5 (80%) of AL-CA patients and 1/5 ATTR-CA. Among patients with suspected acute coronary syndrome (n = 22), obstructive CAD was detected in 9/17 (53%) ATTR-CA and 0/5 AL-CA; hs-cTnI levels were similar between those with and without obstructive CAD. During a follow-up of 17 (8–34) months, chest pain was a significant predictor of HF hospitalization (HR1.86, 95% CI 1.02–3.39, p = 0.042), even after adjustment for CA subtype and CAD. Chest pain is a common symptom in patients with CA, reflects a more advanced cardiac impairment and predicts future HF hospitalization. The etiology of chest pain seems to differ, with obstructive CAD more frequent in ATTR-CA whilst amyloid vascular/perivascular involvement more common in AL-CA. • Chest pain is a frequent symptom in patients with cardiac amyloidosis (CA) and is associated with a more advanced cardiac impairment. • The etiology of chest pain seems to vary based on CA subtype, with coronary artery disease being more frequent in transthyretin CA and vascular/perivascular amyloid involvement in light chains-related CA. • Regardless, patients with chest pain are at higher risk of heart failure hospitalization. [ABSTRACT FROM AUTHOR]