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Background: Postsurgical spinal infections are a severe complication and a challenge to the neurosurgeon due to their complex management. Revision surgeries and the removal of hardware are usually necessary. Recently, advances in nuclear medicine have made it possible to employ radiotracers to identify infections. The radiolabeled antimicrobial peptide technetium-99m-ubiquicidin (99mTc-UBI) (29-41) has been demonstrated to detect bacterial infections. UBI 29-41 is a peptide sequence with selective binding to the anionic cell membrane of bacteria, which has recently been used to differentiate between infection and inflammation. Here, we describe the clinical utility of 99mTc-UBI 29-41 single-photon emission computed tomography-computed tomography (SPECT-CT) in a patient suspected of a postoperative infection. Case description: A 54-year-old male who presented with conus medullaris syndrome secondary to T12 spondylodiscitis and multiple abscess collections was initially managed with debridement, corpectomy, and minimally invasive lateral instrumentation. The patient developed postsurgical empyema near the surgical site. The image study avoided the need for a second surgery and hardware removal. Conclusion: The use of 99mTc-UBI 29-41 SPECT-CT served as a tool to avoid a second invasive procedure; instead, conservative management with antibiotics was performed with an effective outcome after two weeks. This radiotracer has utility in cases in which infection is suspected, but the location is not entirely clear, and information is needed to guide the therapeutic approach.

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The anomalous origin of the coronary arteries (AOCA) has several patterns. Most are functional and asymptomatic. However, some are associated with persistent chest pain and sudden cardiac death. Multiple imaging techniques are available for the assessment of AOCA. We present a report of 4 cases with AOCA, including the anomalous aortic origin of a coronary artery (AAOCA) of the right coronary artery, AAOCA of the circumflex artery, AAOCA of the left anterior descending artery, and AAOCA of the circumflex artery with retroaortic trajectory, in which the clinical manifestations throughout the cases are discussed, highlighting the similarity among patients despite having different patterns. Multiple imaging techniques are indispensable for assessing AOCA, where transthoracic echocardiogram is the first-line study, and cardiac computed tomography provides detailed cardiac and coronary anatomy.

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Non-invasive brain stimulation (NIBS) interventions are promising for the treatment of psychiatric disorders. Notwithstanding, the NIBS mechanisms of action over the dorsolateral prefrontal cortex (DLPFC), a hub that modulates affective and cognitive processes, have not been completely mapped. We aimed to investigate regional cerebral blood flow (rCBF) changes over the DLPFC and the subgenual anterior cingulate cortex (sgACC) of different NIBS protocols using Single-Photon Emission Computed Tomography (SPECT). A factorial, within-subjects, double-blinded study was performed. Twenty-three healthy subjects randomly underwent four sessions of NIBS applied once a week: transcranial direct current stimulation (tDCS), intermittent theta-burst stimulation (iTBS), combined tDCS + iTBS and placebo. The radiotracer 99m-Technetium-ethylene-cysteine-dimer was injected intravenously during the NIBS session, and SPECT neuroimages were acquired after the session. Results revealed that the combination of tDCS + iTBS increased right sgACC rCBF. Cathodal and anodal tDCS increased and decreased DLPFC rCBF, respectively, while iTBS showed no significant changes compared to the placebo. Our findings suggest that the combined protocol might optimize the activity in the right sgACC and encourage future trials with neuropsychiatric populations. Moreover, mechanistic studies to investigate the effects of tDCS and iTBS over the DLPFC are required.

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To explore the role of the interictal and ictal SPECT to identity functional neuroimaging biomarkers for SUDEP risk stratification in patients with drug-resistant focal epilepsy (DRFE). Twenty-nine interictal-ictal Single photon emission computed tomography (SPECT) scans were obtained from nine DRFE patients. A methodology for the relative quantification of cerebral blood flow of 74 cortical and sub-cortical structures was employed. The optimal number of clusters (K) was estimated using a modified v-fold cross-validation for the use of K means algorithm. The two regions of interest (ROIs) that represent the hypoperfused and hyperperfused areas were identified. To select the structures related to the SUDEP-7 inventory score, a data mining method that computes an automatic feature selection was used. During the interictal and ictal state, the hyperperfused ROIs in the largest part of patients were the bilateral rectus gyrus, putamen as well as globus pallidus ipsilateral to the seizure onset zone. The hypoperfused ROIs included the red nucleus, substantia nigra, medulla, and entorhinal area. The findings indicated that the nearly invariability in the perfusion pattern during the interictal to ictal transition observed in the ipsi-lateral putamen F = 12.60, p = 0.03, entorhinal area F = 25.80, p = 0.01, and temporal middle gyrus F = 12.60, p = 0.03 is a potential biomarker of SUDEP risk. The results presented in this paper allowed identifying hypo- and hyperperfused brain regions during the ictal and interictal state potentially related to SUDEP risk stratification.

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BACKGROUND: Focal epilepsies have been described as a network disease. Noninvasive investigative techniques have been used to characterize epileptogenic networks. OBJECTIVE: This study aimed to describe ictal and interictal cortical and subcortical perfusion patterns using single- photon emission computed tomography (SPECT) in patients with drug-resistant epilepsy (DRE). METHODS: Thirty-five interictal-ictal SPECT scans were obtained from 15 patients with DRE. A methodology was developed to get a relative perfusion index (PI) of 74 cortical and sub-cortical brain structures. K-means algorithm, together with modified v-fold cross-validation, was used to identify the two regions of interest (ROIs) that represent hypoperfused and hyperperfused areas. RESULTS: In common with the individual analysis, the statistical analysis evidenced that the hyperperfusion ROIs resulting from group analysis during interictal and ictal involved mainly the cingulate gyrus, cuneus, lingual gyrus, and gyrus rectus as well as the putamen. ROIs hypoperfused included the red nucleus, the substantia nigra, and the medulla. The medians of the group analysis of the hypoperfusion and hyperperfusion ROIs were 0.601-0.565 and 1.133-1.119 for the ictal and interictal states, correspondingly. A group of mostly cortical structures involved in the hyperperfused ROIs in both interictal and ictal states showed no change or negative change in the transition from interictal to ictal state (mean change of -0.002). On the other hand, the brain stem, basal ganglia, red nucleus, and thalamus revealed a mean global change of 0.19, indicating a mild increase in the PI. However, some of these structures (red nucleus, substantia nigra, and medulla oblongata) remained hypoperfused during the interictal to ictal transition. CONCLUSION: The methodology employed made it possible to identify common cortical and subcortical perfusion patterns not directly linked to epileptogenicity, for a better epileptogenic network and sudden unexpected death (SUDEP) mechanism in DRE.

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PURPOSE: Budget cuts among other factors undermine the use of state-of-the-art equipment by many research groups. This doesn't mean that their scientific data are not reliable or top-notch. Resort to adaptations is a recurrent need in their reality. The aim of this study was to assess whether scintigraphy with 99mTcO4 is effective in evaluating the functionality of thyroid grafts after cryopreservation in rats. MATERIAL AND METHODS: 24 rats were randomly distributed into 3 groups: Control Group (CG), without surgical procedure, Hypothyroidism Group (HTG), submitted to total thyroidectomy, and Transplanted Group (TG), with total thyroidectomy and cryopreservation of the thyroid gland for 7 days followed by grafting of a thyroid lobe. A protocol using a gamma camera imaging was conducted fourteen weeks after transplantation, and the whole body 99mTc, focusing on the topic of heterotopic thyroid uptake was evaluated. RESULTS: The images acquired had good quality with no noise and artifacts that could jeopardize its analysis. On the 14th day, HTG displayed no thyroid uptake, and the TG had a clear uptake of the thyroid graft in the topography of the biceps femoris muscle. Presented data also showed that both equipment spatial resolution and alignment (4.375 mm) did not interfere with the physiological uptake of 99mTc by the thyroid graft. CONCLUSION: The viability and functionality of cryopreserved thyroid autotransplantation in rats who underwent total thyroidectomy were successfully accessed by the scintigraphy protocol developed.

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ABSTRACT Background: the diagnosis of Parkinson's disease (PD) can be challenging, especially in the early stages, albeit its updated and validated clinical criteria. Recent developments on neuroimaging in PD, altogether with its consolidated role of excluding secondary and other neurodegenerative causes of parkinsonism, provide more confidence in the diagnosis across the different stages of the disease. This review highlights current knowledge and major recent advances in magnetic resonance and dopamine transporter imaging in aiding PD diagnosis. Objective: This study aims to review current knowledge about the role of magnetic resonance imaging and neuroimaging of the dopamine transporter in diagnosing Parkinson's disease. Methods: We performed a non-systematic literature review through the PubMed database, using the keywords "Parkinson", "magnetic resonance imaging", "diffusion tensor", "diffusion-weighted", "neuromelanin", "nigrosome-1", "single-photon emission computed tomography", "dopamine transporter imaging". The search was restricted to articles written in English, published between January 2010 and February 2022. Results: The diagnosis of Parkinson's disease remains a clinical diagnosis. However, new neuroimaging biomarkers hold promise for increased diagnostic accuracy, especially in earlier stages of the disease. Conclusion: Future validation of new imaging biomarkers bring the expectation of an increased neuroimaging role in the diagnosis of PD in the following years.

RESUMO Antecedentes: O diagnóstico da doença de Parkinson (DP) pode ser desafiador, principalmente nas fases iniciais da doença, embora tenha critérios clínicos atualizados e validados. Os avanços recentes em neuroimagem na DP, além do seu papel já consolidado de excluir causas secundárias e outras causas neurodegenerativas de parkinsonismo, tem contribuído para uma maior confiabilidade no diagnóstico em diferentes estágios da doença. Nesta revisão, nós destacamos os principais avanços de ressonância magnética e imagem do transportador de dopamina em auxiliar o diagnóstico de DP. Objetivo: realizar uma revisão acerca do conhecimento atual sobre o papel da ressonância magnética e imagem do transportador de dopamina no diagnóstico de doença de Parkinson. Método: Realizamos uma revisão não sistemática da literatura através da base de dados PubMed, utilizando as palavras-chave "Parkinson", "magnetic resonance imaging", "diffusion tensor", "diffusion-weighted", "neuromelanin", "nigrosome-1", "single-photon emission computed tomography", "dopamine transporter imaging". A busca foi restrita a artigos escritos em inglês, publicados entre janeiro de 2010 e fevereiro de 2022. Resultados: O diagnóstico de doença de Parkinson continua sendo um diagnóstico clínico, contudo, novos biomarcadores de neuroimagem são promissores para o aumento da acurácia diagnóstica, especialmente em fases mais precoces da doença. Conclusão: A validação futura de novos biomarcadores de imagem traz a expectativa de um maior papel da neuroimagem no diagnóstico de doença de Parkinson nos próximos anos.

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Background: The aim of this study was to determine the advantages of preoperative sentinel lymph node mapping (SLNM) by single photon emission computed tomography/computed tomography (SPECT / CT) in patients with early-stage cutaneous head-and-neck malignancies. Materials and Methods: We conduct a 7-year and 6 months retrospective, cross-sectional study. Patients with early-stage malignant head-and-neck skin tumors and cutaneous adnexa who underwent SLNM by SPECT/CT from March 2012 and December 2019, were included in the study. Results: We retrospectively analyzed 28 patients: Melanoma was the most frequent tumor (64.2%), followed by squamous cell carcinoma (25%). The anterior cheek was the most common functional subsite (25%). Twenty-seven patients (96.4%) had a successful SLN detection with SPECT/CT. Neck lymph node dissection was performed in 23 patients (82.1%). According to the pathological specimen, lymph nodes were found in all of them; hence, the efficacy of the SPECT/CT for SLNM was 100%. At 7-year follow-up, systemic recurrence was found in one patient (3.6%), another had locoregional recurrence (3.6%), and the mortality rate was 3.6%. Conclusions: In early-stage malignant head-and-neck skin tumors, there is a high concordance between SLN found by SPECT/CT and the histopathological results. Preoperative SPECT/CT accurately detects the SLN, assesses unexpected lymph nodes and their drainage pathways, and facilitates their location by reliably showing the relationships between sentinel nodes and important anatomic structures. This allows to perform a clear preoperative evaluation, an accurate staging for all patients and to avoid excessive dissections that could result in cosmetic and functional deformities.

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Abstract Purpose: Budget cuts among other factors undermine the use of state-of-the-art equipment by many research groups. This doesn't mean that their scientific data are not reliable or top-notch. Resort to adaptations is a recurrent need in their reality. The aim of this study was to assess whether scintigraphy with 99mTcO4 is effective in evaluating the functionality of thyroid grafts after cryopreservation in rats. Material and methods: 24 rats were randomly distributed into 3 groups: Control Group (CG), without surgical procedure, Hypothyroidism Group (HTG), submitted to total thyroidectomy, and Transplanted Group (TG), with total thyroidectomy and cryopreservation of the thyroid gland for 7 days followed by grafting of a thyroid lobe. A protocol using a gamma camera imaging was conducted fourteen weeks after transplantation, and the whole body 99mTc, focusing on the topic of heterotopic thyroid uptake was evaluated. Results: The images acquired had good quality with no noise and artifacts that could jeopardize its analysis. On the 14th day, HTG displayed no thyroid uptake, and the TG had a clear uptake of the thyroid graft in the topography of the biceps femoris muscle. Presented data also showed that both equipment spatial resolution and alignment (4.375 mm) did not interfere with the physiological uptake of 99mTc by the thyroid graft. Conclusion: The viability and functionality of cryopreserved thyroid autotransplantation in rats who underwent total thyroidectomy were successfully accessed by the scintigraphy protocol developed. HIGHLIGHTS Adaptations in validated methods are a recurrent trend due to limited budgets which does not diminish their functionality. Scintigraphy with 99mTcO4 is effective in evaluating the functionality of thyroid grafts after cryopreservation in rats. It is possible to adapt human SPECT for other animals for clinical and research purposes.