Laterization of epileptiform discharges in patients with epilepsy and precocious destructive brain insults

Unilateral destructive brain lesions of early development can result in compensatory thickening of the ipsilateral cranial vault. The aim of this study was to determine the frequency of these bone changes among patients with epilepsy and precocious destructive lesions, and whether a relationship exists between these changes and epileptiform discharges lateralization. Fifty-one patients had their ictal / interictal scalp EEG and skull thickness symmetry on MRI analyzed. Patients were divided into three main groups according to the topographic distribution of the lesion on the MRI: hemispheric (H) (n=9); main arterial territory (AT) (n=25); arterial borderzone (Bdz) (n=17). The EEG background activity was abnormal in 26 patients and were more frequent among patients of group H (p= 0.044). Thickening of the skull was more frequent among patients of group H (p= 0.004). Five patients (9.8%) showed discordant lateralization between epileptiform discharges and structural lesion (four of them with an abnormal background, and only two of them with skull changes). In one of these patients, ictal SPECT provided strong evidence for scalp EEG false lateralization. The findings suggest that compensatory skull thickening in patients with precocious destructive brain insults are more frequent among patients with unilateral and large lesions. However, EEG lateralization discordance among these patients seems to be more related to EEG background abnormalities and extent of cerebral damage than to skull changes

Understanding visual saliency in mobile user interfaces

| openaire: EC/H2020/637991/EU//COMPUTEDFor graphical user interface (UI) design, it is important to understand what attracts visual attention. While previous work on saliency has focused on desktop and web-based UIs, mobile app UIs differ from these in several respects. We present findings from a controlled study with 30 participants and 193 mobile UIs. The results speak to a role of expectations in guiding where users look at. Strong bias toward the top-left corner of the display, text, and images was evident, while bottom-up features such as color or size affected saliency less. Classic, parameter-free saliency models showed a weak fit with the data, and data-driven models improved significantly when trained specifically on this dataset (e.g., NSS rose from 0.66 to 0.84). We also release the first annotated dataset for investigating visual saliency in mobile UIs.Peer reviewe

18F-FLUORIDE PET/CT vs 18F-PSMA-1007 TO DETECT BONE METASTASES IN PROSTATE CANCER – A HEAD-TO-HEAD PROSPECTIVE COMPARISON

Introduction/Justification: There have been no head-to-head prospective studies comparing the ability of 18F-Fluoride PET/CT and 18F-PSMA-1007 PET/CT to detect bone metastases due to prostate cancer. So, this study aims to investigate the capacity of 18F-PSMA-1007 to detect bone metastases compared to the reference standard (18F-Fluoride PET/CT) in PCa patients, considering mainly the presence or absence, number and biodistribution of lesions. Objectives: This prospective study aimed to compare the ability of 18F-PSMA-1007 PET/CT and 18F-Fluoride PET/CT to detect bone metastases. Materials and Methods: Twenty-eight patients with prostate cancer biochemical recurrence were submitted to both 18F-PSMA-1007 PET/CT and 18F-fluoride PET/CT studies. These two radiotracers evaluated the presence or absence, number of lesions, body and bone localization, lesion pattern, and probability of malignancy. Results: Twenty-eight patients with prostate cancer biochemical recurrence, mean age of 70.8 ± 8.7 years; Gleason score = 7.72 ± 1.23 and the mean total PSA = 50.2 ± 183.9 ng/mL were included. On a per-patient basis, considering that 18F-Fluoride PET/CT is the gold standard, the 18F-PSMA-1007 PET/CT presented a concordance rate of 96.43%, sensitivity (S) of 92.3%, specificity (E) of 100%, predictive positive value (PPV) of 100% and predictive negative value (PNV) of 93.80% on lesion detection. Evaluating the number of lesions, 18F-PSMA-1007 PET/CT determined a PPV of 91.8% and sensitivity of 86.5%. Bone localization in 18F- Fluoride and 18F-PSMA-1007 were predominant in the dorsal spine (34.62%/62.65%), ribs (32.69%/32.65%)and pelvis (9.62%/12.24%), respectively. Both studies had a concordant rate of 80.76% on rib evaluation, the most conflicting site of uptake between the methods in actual literature. Conclusion: 18F-PSMA-1007 has the same ability as 18F-Fluoride to detect PCa bone metastasis in biochemical recurrence, with concordance of 96,43% and 80,00% on a per-patient and per-lesion evaluation, respectively. Both studies demonstrated predominancy of sclerotic and medullar lesions, located preferentially on dorsal spine and ribs, being the last one concordant in 80,76% of studies

DUAL-TRACER PET/CT IN MYELOFIBROSIS: A CASE SERIES ANALYSIS USING 18F-FDG AND 18F-PSMA PET/CT

Introduction/Justification: Myelofibrosis, a clonal disorder of hematopoietic stem cells, is characterized by chronic bone marrow inflammation and progressive fibrosis, resulting in hypocellularity and the displacement of neoplastic cells to extramedullary organs such as the spleen and liver, leading to splenomegaly and hepatomegaly. Hematopoietic stem cell transplantation is currently the only curative treatment, with five-year survival rates ranging between 51% and 61%, underscoring the need for novel diagnostic and therapeutic strategies. In recent years, positron emission tomography combined with computed tomography (PET/CT) using 18F-fluorodeoxyglucose (18F-FDG) has emerged as a valuable tool for assessing the glycolytic activity of various neoplasms, although there are limited reports on its utility in myelofibrosis. Concurrently, interest has grown in using the prostate-specific membrane antigen (PSMA) tracer to evaluate the neoangiogenic activity of diverse neoplasms. This study aims to compare glycolytic activity and neoangiogenic activity, assessed through 18F-FDG and 18F-PSMA PET/CT imaging, respectively, in patients with myelofibrosis. Report: Three patients diagnosed with myelofibrosis, aged 69, 71, and 74 years, underwent PET/CT scans on consecutive days, acquired 60 minutes after intravenous administration of 0.1 mCi/kg of 18F-FDG and 90 minutes after intravenous injection of 0.1 mCi/kg of 18F-PSMA. The images were analyzed by two nuclear medicine physicians and a radiologist. The maximum standardized uptake value (SUV) of the bone marrow, as well as the SUV and dimensions of the liver and spleen, were measured. Two patients exhibited mild to moderate diffuse increased uptake of both 18F-FDG and 18F-PSMA in the bone marrow (SUV-FDG: 6.4 and 3.5; SUV-PSMA: 3.5 and 1.7). One of them displayed mild hepatomegaly (18.7 cm), and both had marked splenomegaly (21.5 and 30.3 cm). Liver and spleen uptake of 18F-FDG was close to normal in both patients (SUV-FDG: 2.4 to 3.1), while moderate uptake of 18F-PSMA was observed in these organs (SUV-PSMA: 5.6 to 8.4), at least partially physiological and expected for this radiopharmaceutical. The third patient, who had undergone splenectomy, did not exhibit significant uptake of either tracer in the bone marrow but displayed marked uptake of 18F-PSMA in the liver (SUV-PSMA = 14.8), possibly physiological, with normal 18F-FDG uptake (SUV-FDG = 3.9). Conclusion: Patients with myelofibrosis appear to exhibit variable degrees of glycolytic activity and neoangiogenesis in the bone marrow, as detected by PET/CT imaging with 18F-FDG and 18F-PSMA. The moderate to marked uptake of 18F-PSMA in the liver and spleen, at least partly physiological, along with the uptake in the bone marrow in some cases, may suggest a theranostic potential of this radiopharmaceutical in myelofibrosis

Proposal for a quantitative F-18-FDG PET/CT metabolic parameter to assess the intensity of bone involvement in multiple myeloma

Many efforts have been made to standardize the interpretation of F-18-FDG PET/CT in multiple myeloma (MM) with qualitative visual analysis or with quantitative metabolic parameters using various methods for lesion segmentation of PET images. The aim of this study was to propose a quantitative method for bone and bone marrow evaluation of F-18-FDG PET/CT considering the extent and intensity of bone F-18-FDG uptake: Intensity of Bone Involvement (IBI). Whole body F-18-FDG PET/CT of 59 consecutive MM patients were evaluated. Compact bone tissue was segmented in PET images using a global threshold for HU of the registered CT image. A whole skeleton mask was created and the percentage of its volume with F-18-FDG uptake above hepatic uptake was calculated (Percentage of Bone Involvement - PBI). IBI was defined by multiplying PBI by mean SUV above hepatic uptake. IBI was compared with visual analysis performed by two experienced nuclear medicine physicians. IBI calculation was feasible in all images (range:0.00-1.35). Visual analysis categorized PET exams into three groups (negative/mild, moderate and marked bone involvement), that had different ranges of IBI (multi comparison analysis, p < 0.0001). There was an inverse correlation between the patients' hemoglobin values and IBI (r = -0.248;p = 0.02). IBI score is an objective measure of bone and bone marrow involvement in MM, allowing the categorization of patients in different degrees of aggressiveness of the bone disease. The next step is to validate IBI in a larger group of patients, before and after treatment and in a multicentre setting.9CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informação305110/2018-7; 311841/2018-02009/54065-0; 2018/00654-