Browsing by Author "Silva, Claudio"
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Publication A real-time fMRI neurofeedback system for the clinical alleviation of depression with a subject-independent classification of brain states: A proof of principle study(2022) Pereira, Jaime A.; Ray, Andreas; Rana, Mohit; Silva, Claudio; Salinas, César; Zamorano, Francisco; Irani, Martín; Opazo, Patricia; Sitaram, Ranganatha; Ruíz, SergioMost clinical neurofeedback studies based on functional magnetic resonance imaging use the patient's own neural activity as feedback. The objective of this study was to create a subject-independent brain state classifier as part of a real-time fMRI neurofeedback (rt-fMRI NF) system that can guide patients with depression in achieving a healthy brain state, and then to examine subsequent clinical changes. In a first step, a brain classifier based on a support vector machine (SVM) was trained from the neural information of happy autobiographical imagery and motor imagery blocks received from a healthy female participant during an MRI session. In the second step, 7 right-handed female patients with mild or moderate depressive symptoms were trained to match their own neural activity with the neural activity corresponding to the “happiness emotional brain state” of the healthy participant. The training (4 training sessions over 2 weeks) was carried out using the rt-fMRI NF system guided by the brain-state classifier we had created. Thus, the informative voxels previously obtained in the first step, using SVM classification and Effect Mapping, were used to classify the Blood-Oxygen-Level Dependent (BOLD) activity of the patients and converted into real-time visual feedback during the neurofeedback training runs. Improvements in the classifier accuracy toward the end of the training were observed in all the patients [Session 4–1 Median = 6.563%; Range = 4.10–27.34; Wilcoxon Test (0), 2-tailed p = 0.031]. Clinical improvement also was observed in a blind standardized clinical evaluation [HDRS CE2-1 Median = 7; Range 2 to 15; Wilcoxon Test (0), 2-tailed p = 0.016], and in self-report assessments [BDI-II CE2-1 Median = 8; Range 1–15; Wilcoxon Test (0), 2-tailed p = 0.031]. In addition, the clinical improvement was still present 10 days after the intervention [BDI-II CE3-2_Median = 0; Range −1 to 2; Wilcoxon Test (0), 2-tailed p = 0.50/ HDRS CE3-2 Median = 0; Range −1 to 2; Wilcoxon Test (0), 2-tailed p = 0.625]. Although the number of participants needs to be increased and a control group included to confirm these findings, the results suggest a novel option for neural modulation and clinical alleviation in depression using noninvasive stimulation technologies.Item Central obesity and not age increases skeletal muscle lipids, without influencing lean body mass and strength(Grupo Arán, 2015) de la Maza, María; Hirsch, Sandra; Jara, Natalia; Leiva, Laura; Barrera, Gladys; Silva, Claudio; Pañella, Loreto; Henríquez, Sandra; Bunout, DanielBACKGROUND/AIMS: To measure skeletal muscle lipid infiltration, its association with insulin resistance (IR) lean mass and function, in Chilean men differing in age and body composition. Our hypothesis was that muscle lipid accumulation would be higher among older and heavier individuals and this would deteriorate insulin sensitivity (IS) and decrease muscle mass and function, both features of the ageing process. METHODS: Healthy men (38 < 55 and 18 > 65 years), underwent anthropometric measurements, body composition assessment through radiologic densitometry, Nuclear Magnetic Resonance spectroscopy at the tibialis anterioris muscle to measure intra (IMCL) and extramyocellular lipids (EMCL), quadriceps and handgrip strength, 12 minute walking distance and serum biochemistry (haemoglobin, lipoproteins, creatinine, ultrasensitive C Reactive Protein, fasting and post glucose insulin and glucose concentrations, to assess IS). Physical activity was estimated by actigraphy. RESULTS: 23 men were eutrophic, 26 were overweight and 7 were obese and mostly sedentary, independent of age. Both IMCL and EMCL were higher in overweight/ obese men. Abdominal fat was negatively associated with IS and positively correlated with muscle lipid accretion (both IMCL and EMCL), but not with age. As expected, older individuals had lower muscle mass and strength, but not more adipose tissue nor intramyocellular lipids, yet were more glucose intolerant. CONCLUSIONS: central obesity was associated with IMCL and EMCL infiltration and IR. This type of lipid accretion was not related with ageing nor age-related sarcopenia. Older individuals were more glucose intolerant, which was explained by a decrease of insulin secretion more than adiposity-related IR.Item Computed tomography imaging of complications of acute cholecystitis(2018) Schiappacasse, Giancarlo; Soffia, Pablo; Silva, Claudio; Villacrés, FabianAcute cholecystitis (AC) is a frequent complication of biliary cholelithiasis. Although ultrasound is the first diagnostic imaging procedure, frequently the initial imaging modality is computed tomography (CT). Therefore, familiarization of CT findings in AC and potential related complications are extremely important. This pictorial essay reviews a broad spectrum of complications related to AC and its key findings in CT.Item Concordancia Interobservador para la Validación del PI-RADS v2(2019) Labra, Andrés; Silva, Claudio; Schiappacasse, Giancarlo; Barahona, Daniela; Skoknic, VelimirObjetivo: Evaluar la variabilidad interobservador en el uso de la versión 2.0 del PIRADS (PI-RADS v2), en lectores experimentados y no experimentados. Materiales y Métodos: Estudio retrospectivo de análisis de concordancia de lectores. Entre enero de 2015 y diciembre de 2016, 1.656 sujetos fueron estudiados mediante resonancia magnética multiparamétrica (RMmp) de próstata en nuestra institución. Se estimó la distribución porcentual del reporte en categoría PI-RADS v2, y con esa información, se realizó una selección de 150 casos con esquema de aleatorización estratificada a las distribuciones porcentuales de cada categoría. Dichos casos fueron anonimizados, presentados a tres lectores con cinco, cuatro y dos años de experiencia en lectura de RMmp además de tener más de un año de experiencia en el uso del PIRADS v2 siendo leídos en forma individual. Los datos resultantes fueron analizados en forma independiente por un cuarto investigador. Resultados: El valor de kappa ponderado para los observadores fue de 0,69 (IC 95: 0,64 a 0,75). La mayor concordancia correspondió a los lectores de mayor experiencia, donde alcanza un valor de 0,72 (IC 95%: 0,69 a 0,76). La concordancia entre los valores PI-RADS que determinan seguimiento o bien una intervención de acuerdo a elementos clínicos (1–2–3) y conducta activa (4–5) correspondió a 0,70 (IC 95%: 0,59 a 0,78). Discusión: Se logró demostrar un acuerdo sustancial entre radiólogos utilizando el PIRADS v2 para la detección en RMmp de lesiones sospechosas, mayor entre los dos lectores más experimentados. Sin embargo, la comparación del lector de menor experiencia con los de mayor experiencia también presentó una importante concordancia. Los valores de concordancia entre observadores para PI-RADS 4 fueron similares a los reportados en la literatura.Item Densidad de APE en pacientes PI-RADS 3. Un parámetro clínico útil para su manejo(2019) Tapia, María Fernanda; Labra, Andrés; Adlerstein, Isabel; Olivares, Juan Pablo; Schultz, Marcela; Silva, Claudio; Pinochet, Rodrigo; Orvieto, MarceloAnalizar las biopsias realizadas en paciente categorizados PIRADS 3 en nuestra institución desde el segundo semestre del año 2016 al primer semestre del año 2018 y describir la correlación de la densidad de PSA con la incidencia de cáncer de próstata. Evaluar el rol de la densidadnde PSA en la indicación de estudio histológico en pacientes PIRADS 3. Método: Trabajo autorizado por el comité de ética de nuestra institución. Se realizó búsqueda en el PACs, de todos los informes de RM multiparamétricas de próstata que incluyeran la categoría ¨PIRADS 3¨ en el periodo señalado. De ellos se calculó la densidad de PSA, con el último valor de PSA registrado en la ficha clínica previo a RM y volumen prostático en RM. Se procedió a buscar los pacientes con estudio histológico. Se correlacionó los resultados de biopsias con el valor de densidad de PSA. Realizamos análisis uni y multivariados, análisis estadísticos con sensibilidad, especificidad y uso de curva ROC. Resultados: De las 2416 RMmp de próstata realizadas en nuestra institución en las fechas ya descritas, se encontraron 424 informes catalogados con score PIRADS 3, y 267 de esos pacientes tenían estudio y seguimiento institucional, de los cuales 134 contaban con biopsia. La muestra tenía un promedio de edad de 60 años, y una mediana de densidad de PSA de 0,10 (RIC 0,07-0,14). Se encontraron 36 biopsias con cáncer clínicamente significativo (Gleason > 6), lo que corresponde a 26,8% de la muestra, valor similar al encontrado en la literuatua. En estos pacientes se obtuvo un punto de corte óptimo de densidad de PSA de 0,11, con una sensibilidad y especificidad de 67% y un AUC de 0,68. Una densidad de PSA de 0,11 presenta un OR de 4,1, con una probabilidad de 4 veces más de encontrar un cáncer de próstata por sobre este valor (IC 95% 1,3-9,8), lo cuál es estadísticamente significativo con un p igual a 0,01. Conclusión: La DAPE sobre 0,11 ng/ml/cc puede considerarse como una herramienta adicional para indicar biopsia en pacientes con RMmp PI-RADS3, aumentando la precisión para la detección de cáncer de próstata clínicamente significativos ayudando a disminuir estudios histológicos innecesarios.Item Docosahexaenoic acid levels in erythrocytes and their association with the University Selection Test Outcomes in Chile(2018) Valenzuela, Rodrigo; Barrera, Cynthia; Orellana, Yasna; Almagià, Atilio; Arancibia, Violeta; Larraín, Cristian; Silva, Claudio; Billeke, Pablo; Zamorano, Francisco; Martínez, Víctor; Valenzuela, Alfonso; Ivanovic, DanizaThe aim of this study was to quantitate the relative impact of DHA and AA levels in erythrocytes, anthropometric parameters and socio-economic status of school-age children, of both genders, graduated from high school in Chile, on the scholastic achievement in the University Selection Test (Prueba de Selección Universitaria, PSU) both language scholastic achievement (LSA) and mathematics scholastic achievement (MSA). A representative sample of 671 school-age young graduated from high school in 2013, 550 and 548 of them took the PSU for LSA and MSA, respectively. Only school-age young with high (n=91) and low (n=69) SA in both tests were considered. A total of 122 school-age children agreed to participate in the study and were divided as follows: Group 1: high PSU outcome (n=70; males n=48) and Group 2: low PSU outcome (n=52; males n=23). Data were analyzed by means of SAS software. Independently of gender, DHA, socio-economic status and head circumference-for-age Z-score were the most relevant parameters explaining both LSA (R2=0.650; p<0.0001) and MSA outcomes (R2=0.700; p<0.0001). These results can be useful for nutrition, health and education planning, in order to protect children starting from an early age and thus increase their school outcomes.Item Finger chondroid syringoma as a hypoechoic subcutaneous nodule in ultrasound(Lippincott Williams & Wilkins, 2013) Whittle, Carolina; Mackinnon, John; Cabrera, Roberto; Silva, Claudio; Pires, Yumay; González, RobinsonChondroid syringoma (CS) is an uncommon, benign epithelial skin mixed tumor. It is often located in the head and neck and is unusual in other parts of the body. It may be seen as a skin or soft tissue tumor. We present findings on high-resolution ultrasound and histology in a case of benign CS located on the right index finger. High-resolution ultrasound showed a solid hypoechoic, well-defined subcutaneous mass, adjacent to the tendon. Complete surgical excision was performed, and histopathology demonstrated an apocrine mixed tumor (CS). Although CS histological findings are well described, radiological features have been reported only in few cases and mainly in magnetic resonance. Chondroid syringoma should be suspected by high-resolution ultrasound as a differential diagnosis for a solid slow-growing soft tissue nodule in a finger, especially if the lesion has no contact with the underlying tendon.Item Impact of anthropometric nutritional parameters on the university selection test in Chile: A multifactorial approach(Elsevier Inc., 2019-01) Ivanovic, Daniza; Valenzuela, Rodrigo; Almagia, Atilio; Barrera, Cynthia; Arancibia, Violeta; Larraín, Cristian; Silva, Claudio; Billeke, Pablo; Zamorano, Francisco; Villagrán, Francisca; Orellana, Yasna; Martínez, VíctorObjectives Scholastic achievement (SA) is a multifactorial problem that depends on factors related to the child, the child's family, and the educational system. The aim of this study was to quantify the relative impact of significant variables at the beginning of high school during 2010 (first grade of high school [1 HSG]) on 2013 university selection test (Prueba de Seleccion Universitaria [PSU]) outcomes, both in language scholastic achievement (LSA) and mathematics scholastic achievement (MSA), when students graduated from high school (4 HSG). This was done at the time of university admission with a multicausal approach. The purpose was to confirm the hypothesis that the level of educational establishment SA, intellectual ability, sex, parental schooling levels, and head circumference for age Z-score at the onset of high school are the most relevant parameters associated with 2013 PSU outcomes, both in LSA and MSA. Methods A representative, proportional, and stratified sample of 671 children of both sexes who enrolled in 1 HSG in 2010 (mean age: 14.8 ± 0.6 y) participated in the study. Nutritional, intellectual, brain developmental, cardiovascular risk, socio-to-economic, demographic, and educational variables were quantitated. SA was assessed at 4 HSG with the 2013 PSU tests. Data were analyzed with SAS software. Results Educational establishment SA, intellectual ability, maternal schooling, and age Z-score were the most relevant parameters to explain LSA (R2 = 0.493; P < 0.0001) and MSA variance in addition to sex (male), but only in MSA (R2 = 0.600; P < 0.0001). Conclusions These findings confirm the hypothesis and can be useful to support nutritional, health, and educational planning.Item Likelihood ratio (razón de verosimilitud): definición y aplicación en Radiología(Sociedad Argentina de Radiologia, 2017) Silva, Claudio; Molina, MThe properties of a diagnostic test such as sensitivity, specificity and predictive values (positive and negative) are well known. Likelihood ratios are an alternative for summarising diagnostic accuracy, yet providing a more powerful approach to clinical interpretation and decision-making.Item Metastatic pulmonary calcification: High-resolution computed tomography findings in 23 cases(Colegio Brasileiro De Radiologia, 2017) Belém, Luciana; Souza, Carolina; Souza, Arthur; Escuissato, Dante; Hochhegger, Bruno; Nobre, Luiz; Rodrigues, Rosana; Gomes, Antônio; Silva, Claudio; Guimarães, Marcos; Zanetti, Gláucia; Marchiori, EdsonOBJECTIVE: The aim of this study was to evaluate the high-resolution computed tomography (HRCT) findings in patients diagnosed with metastatic pulmonary calcification (MPC). MATERIALS AND METHODS: We retrospectively reviewed the HRCT findings from 23 cases of MPC [14 men, 9 women; mean age, 54.3 (range, 26-89) years]. The patients were examined between 2000 and 2014 in nine tertiary hospitals in Brazil, Chile, and Canada. Diagnoses were established by histopathologic study in 18 patients and clinical-radiological correlation in 5 patients. Two chest radiologists analyzed the images and reached decisions by consensus. RESULTS: The predominant HRCT findings were centrilobular ground-glass nodules (n = 14; 60.9%), consolidation with high attenuation (n = 10; 43.5%), small dense nodules (n = 9; 39.1%), peripheral reticular opacities associated with small calcified nodules (n = 5; 21.7%), and ground-glass opacities without centrilobular ground-glass nodular opacity (n = 5; 21.7%). Vascular calcification within the chest wall was found in four cases and pleural effusion was observed in five cases. The abnormalities were bilateral in 21 cases. CONCLUSION: MPC manifested with three main patterns on HRCT, most commonly centrilobular ground-glass nodules, often containing calcifications, followed by dense consolidation and small solid nodules, most of which were calcified. We also described another pattern of peripheral reticular opacities associated with small calcified nodules. These findings should suggest the diagnosis of MPC in the setting of hypercalcemia.Item MRI/TRUS fusion vs. systematic biopsy: intra-patient comparison of diagnostic accuracy for prostate cancer using PI-RADS v2(2020) Labra, Andrés; González, Fernando; Silva, Claudio; Franz, Gerhard; Pinochet, Rodrigo; Gupta, Rajan TObjective: To evaluate the efficacy of multiparametric magnetic resonance/transrectal ultrasound fusion (MRI/TRUS fusion) biopsy versus systematic biopsy and its association with PI-RADS v2 categories in patients with suspected prostate cancer. Materials and methods: 122 patients undergoing both MRI/TRUS fusion and systematic biopsy, with suspicion of prostate cancer, with suspicious findings on MRI based on PI-RADS v2, were included between April 2016 and March 2017. Comparison of tumor detection rates using each technique and combined techniques was performed for all lesions as well as those that are traditionally difficult to access (i.e., anterior lesions). Results: Prostate cancer was detected in 83/122 patients (68%) with 74.6% clinically significant lesions (Gleason 3 + 4 or greater). There was a statistically significant difference in presence of clinically significant prostate cancer in PI-RADS v2 categories of 3, 4, and 5 (20%, 52% and 77%, respectively, p < 0.001). Fusion biopsy was positive in a significantly higher percentage of patients versus systematic biopsy (56% versus 48%, respectively, p < 0.05). The fusion biopsy alone was positive in 20%. Of 34 patients with anterior lesions on MRI, 44% were detected only by fusion biopsy, with a joint yield of 71%. In patients with previous negative systematic biopsies, 48.7% lesions were found by fusion biopsy with 20.5% being exclusively positive by this method. The percentage of positive cores for fusion biopsies was significantly higher than for systematic biopsies (26% vs. 12.3%, p < 0.001). Conclusion: The incorporation of MRI/TRUS fusion biopsy significantly improves the detection rate of prostate cancer versus systematic biopsy, particularly for anterior lesions.Item Nutritional assessment by subjective methods versus computed tomography to predict survival in oncology patients(2021) Geldern, Paula Von; Salas, Claudio; Alvayay, Pablo; Silva, Claudio; Maza, Maria Pía de laObjectives The aim of this study was to analyze the association between survival and two validated methods of nutritional assessment: body composition through computed tomography (CT) scans and Patient-Generated Subjective Global Assessment (PG-SGA). Methods Cancer-bearing patients (n = 103) hospitalized in the Oncology Ward of Clínica Alemana in Santiago, Chile, for palliative or curative treatment were assessed by both methods. Images from abdominal CT scans at the L3 level were analyzed by SliceOmatic (version 5.0), to measure muscle and fat areas and densities. Skeletal muscle mass index (MMI) was calculated using total abdominal mass area (psoas + rest of muscles)/ height2. These were compared with those obtained for assessment of trauma of 130 healthy young adults (18–40 y of age), as reference control values. Sarcopenia was established as MMI<1 SD compared with control participants. Results Patients with cancer had less muscle and higher abdominal fat areas compared with controls (P < 0.05). According to the PG-SGA, ~50% were classified as malnourished. Patients were followed for 38 mo, when 53% had died. Survival time was significantly and negatively correlated with PG-SGA score, cancer stage, and sarcopenia, independent of age and sex. Multivariate analysis included both cancer stage and nutritional assessment variables. Conclusions Together with cancer stage, both CT measurements and subjective assessment of nutritional status through PG-SGA can adequately identify cancer patients with a higher mortality risk, independent of age and sex. However, the latter is less costly and simple to use; it should be included as a valuable tool during management of patients with cancer.Item Parallel Artery and Vein: Sign of Benign Nature of Breast Masses(American Roentgen Ray Society, 2012) Horvath, Eleonora; Silva, Claudio; Fasce, Gerardo; Ferrari, Camilo; Pinochet, Miguel; Galleguillos, Cecilia; Soto, EduardoOBJECTIVE: The purpose of this study was to assess the parallel artery and vein sign at color Doppler breast ultrasound as a predictor of the benign nature of breast masses. SUBJECTS AND METHODS: A prospective study was performed to identify evidence of a parallel artery and vein in breast lesions consecutively biopsied with a 14-gauge needle under ultrasound guidance. Sensitivity, specificity, positive and negative predictive values, likelihood ratios, and 95% CIs for the parallel artery and vein sign were calculated. RESULTS: The parallel artery and vein sign was identified in 142 of the 1074 masses (13.2%). The specificity for benignity was 99.3% (CI 95%, 98.3-100.0%); sensitivity, 17.6% (CI 95%, 15.0-20.3%); positive predictive value, 99.0% (CI 95%, 96.7-100); negative predictive value, 30.0% (CI 95%, 27.0-32.9); positive likelihood ratio, 24.7 (CI 95%, 21.2-28.7); and negative likelihood ratio, 0.83 (CI 95%, 0.80-0.86). Among masses found to have the parallel artery and vein sign, all BI-RADS ultrasound category 3 and 95.1% of BI-RADS 4 lesions were determined to be benign. CONCLUSION: Although the parallel artery and vein sign is an uncommon finding, it has a significant association with benign pathologic results (96.5%) with a positive likelihood ratio of 24.7. The presence of this color Doppler ultrasound finding in breast masses in BI-RADS ultrasound categories 3 and 4 reinforces the benign nature and may allow follow-up rather than biopsy in the care of some patients.Publication Patients recovering from COVID-19 who presented with anosmia during their acute episode have behavioral, functional, and structural brain alterations(2024) Kausel, Leonie; Figueroa-Vargas, Alejandra; Zamorano, Francisco; Stecher, Ximena; Aspé-Sánchez, Mauricio; Carvajal-Paredes, Patricio; Márquez-Rodríguez, Víctor; Martínez-Molina, María Paz; Román, Claudio; Soto-Fernández, Patricio; Valdebenito-Oyarzo, Gabriela; Manterola, Carla; Uribe-San-Martín, Reinaldo; Silva, Claudio; Henríquez-Ch, Rodrigo; Aboitiz, Francisco; Polania, Rafael; Guevara, Pamela; Muñoz-Venturelli, Paula; Soto-Icaza, Patricia; Billeke, PabloPatients recovering from COVID-19 commonly exhibit cognitive and brain alterations, yet the specific neuropathological mechanisms and risk factors underlying these alterations remain elusive. Given the significant global incidence of COVID-19, identifying factors that can distinguish individuals at risk of developing brain alterations is crucial for prioritizing follow-up care. Here, we report findings from a sample of patients consisting of 73 adults with a mild to moderate SARS-CoV-2 infection without signs of respiratory failure and 27 with infections attributed to other agents and no history of COVID-19. The participants underwent cognitive screening, a decision-making task, and MRI evaluations. We assessed for the presence of anosmia and the requirement for hospitalization. Groups did not differ in age or cognitive performance. Patients who presented with anosmia exhibited more impulsive alternative changes after a shift in probabilities (r = − 0.26, p = 0.001), while patients who required hospitalization showed more perseverative choices (r = 0.25, p = 0.003). Anosmia correlated with brain measures, including decreased functional activity during the decision-making task, thinning of cortical thickness in parietal regions, and loss of white matter integrity. Hence, anosmia could be a factor to be considered when identifying at-risk populations for follow-upItem Prospective validation of the ultrasound based TIRADS (Thyroid Imaging Reporting And Data System) classification: results in surgically resected thyroid nodules(Springer, 2017) Horvath, Eleonora; Silva, Claudio; Majlis, Sergio; Rodriguez, Ignacio; Skoknic, Velimir; Castro, Alex; Rojas, Hugo; Niedmann, Juan Pablo; Madrid, Arturo; Capdeville, Felipe; Whittle, Carolina; Rossi, Ricardo; Dominguez, Miguel; Tala, HernánOBJECTIVE: To assess performance of TIRADS classification on a prospective surgical cohort, demonstrating its clinical usefulness. METHODS: Between June 2009 and October 2012, patients assessed with pre-operative ultrasound (US) were included in this IRB-approved study. Nodules were categorised according to our previously described TIRADS classification. Final pathological diagnosis was obtained from the thyroidectomy specimen. Sensitivity, specificity, positive/negative predictive values and likelihood ratios were calculated. RESULTS: The study included 210 patients with 502 nodules (average: 2.39 (±1.64) nodules/patient). Median size was 7 mm (3-60 mm). Malignancy was 0 % (0/116) in TIRADS 2, 1.79 % (1/56) in TIRADS 3, 76.13 % (185/243) in TIRADS 4 [subgroups: TIRADS 4A 5.88 % (1/17), TIRADS 4B 62.82 % (49/78), TIRADS 4C 91.22 % (135/148)], and 98.85 % (86/87) in TIRADS 5. With a cut-off point at TIRADS 4-5 to perform FNAB, we obtained: sensitivity 99.6 % (95 % CI: 98.9-100.0), specificity 74.35 % (95 % CI: 68.7-80.0), PPV 82.1 % (95 % CI: 78.0-86.3), NPV 99.4 % (95 % CI: 98.3-100.0), PLR 3.9 (95 % CI: 3.6-4.2) and an NLR 0.005 (95 % CI: 0.003-0.04) for malignancy. CONCLUSION: US-based TIRADS classification allows selection of nodules requiring FNAB and recognition of those with a low malignancy risk. KEY POINTS: • TIRADS classification allows accurate selection of thyroid nodules requiring biopsy (TIRADS 4-5). • The recognition of benign/possibly benign patterns can avoid unnecessary procedures. • This classification and its sonographic patterns are validated using surgical specimens.Publication RadioGraphics International Team Initiatives(2022) Luna, Antonio; Silva, Claudio; Rossi, Santiago; Celso, HyginoItem Radioiodine-Induced Salivary Gland Damage Detected by Ultrasonography in Patients Treated for Papillary Thyroid Cancer: RAI activity and risk(2020) Horvath, Eleonora; Skoknic, Velimir; Majlis, Sergio; Tala, Hernán; Silva, Claudio; Castillo, Eliette; Whittle, Carolina; Niedmann, Juan Pablo; González, PaulinaAn important side effect of radioactive iodine (RAI) therapy in patients treated for papillary thyroid cancer (PTC) is chronic sialadenitis. Neck ultrasonography (US) easily recognizes radioiodine-induced salivary gland abnormalities. The objectives of this study were to determine the prevalence of US-detected sialadenitis caused by RAI and to identify the risk factors associated with this damage. Methods: This nonconcurrent cohort study includes all PTC-operated patients who were treated with RAI between 2007 and 2017 and were systematically evaluated with preoperative and follow-up neck US that included targeted exploration of the major salivary glands. Patients with pre-existing salivary gland diseases were excluded. The anatomical damage (diminished glandular volume, wavy contours, hypoechogenicity, and heterogeneity) was qualitatively assessed and compared with the preoperative study. RAI activity, sex, age, and preparation method were evaluated as risk factors using univariate and multivariate analyses with logistic regression. Results: Enrolled in this study were 570 patients who received a median RAI activity of 3700 MBq (100 mCi). On US, we found 143 patients (25.1%) with damage in at least one of their salivary glands: all had parotid damage (77 bilaterally) and 14 (9.8%) also had submandibular gland damage (7 of them bilaterally). The multivariate analysis indicated that the risk of sialadenitis was significantly (p < 0.01) correlated with both RAI activity and sex (14.1% of males vs. 28.5% of females). However, the main risk factor was RAI activity; no injury was detected in 156 patients who received 1110 MBq (30 mCi) and 1850 MBq (50 mCi) of RAI. In the groups of patients receiving 3700 MBq (100 mCi), 5550 MBq (150 mCi) and ≥7400 MBq (≥200 mCi), atrophy was found in 21%, 46.9%, and 77.7% of patients, respectively. Age and preparation method were not related to an increased risk of atrophy in this study. Conclusions: Chronic sialadenitis is common and affects approximately one fourth of patients who receive 3700 MBq (100 mCi) or higher RAI activity. The main risk factor for this injury is the total RAI activity administered. By using the lowest effective activity possible, irreversible anatomical damage in salivary glands can be minimized. US is an excellent tool to diagnose post-RAI atrophy.Item Resonancia magnética mamaria preoperatoria – la gran polémica(2011) Horvath, Eleonora; Galleguillos, María; Malodonado, Paulina; Fernández, Montserrat; Sañudo, Mercedes; Tiscornia, Paula; Bazán, Juan; Silva, Claudio; Pinochet, Miguel; Gálvez, Joceliyn; Soza, Iván; Uchida, Marcela; Wenzel, Heriberto; Soto, Eduardo; González, Paulina; Ríos, Chyla; Durán, María PazEl estudio preoperatorio en búsqueda de multifocalidad, multicentricidad y bilateralidad –antes considerada la indicación más sólida de la resonancia magnética (RM) mamaria– hoy se encuentra fuertemente cuestionada en la literatura. En este trabajo nos propusimos evaluar la capacidad de la RM mamaria en nuestro centro para mejorar la etapificación radiológica preoperatoria realizada por métodos convencionales y determinar la proporción de las pacientes en que genera cambio en el enfoque quirúrgico. Hemos revisado retrospectivamente las RM preoperatorias entre enero de 2009 y junio de 2010. Clasificación: Grupo1: la RM no aportó información nueva. Grupo 2: al detectar lesiones adicionales, mejoró la etapificación radiológica, sin cambiar el tipo de la cirugía planificada. Grupo3: demostró nuevas lesiones no malignas y causó cirugía inútil. Grupo 4: cambió correctamente el tipo de cirugía planeada en base a los estudios convencionales. En los 18 meses se realizaron 419 RM mamarias, el 39% de ellas en preoperatorio. Para el análisis se han reclutado 128 pacientes con la siguiente distribución en los grupos predeterminados: Grupo 1 (66%), Grupo 2 (20%), Grupo 3 (2%) y Grupo 4 (12%). En el 95,3% de las pacientes se logró realizar una sola cirugía con márgenes libres. Este trabajo demostró la utilidad de la RM preoperatoria en nuestra práctica: permite una mejor etapificación radiológica en el tercio de las pacientes e incluso cambia correctamente el enfoque quirúrgico en el 12% de los casos.Item Revisiting a Forgotten Organ: Thymus Evaluation by PET-CT(2020) Hasson, Daniel; Schiappacasse, Giancarlo; Alegría, Julia; Silva, ClaudioIncidental thymic lesion findings have increased. An adequate characterization of these lesions in positron emission tomography/computed tomography (PET-CT) is essential, since it is used as part of many oncological planning procedures. Representative cases have been selected regarding the most important aspects of thymus imaging in PET-CT and how this technique can contribute to an accurate diagnosis or treatment planning. Specifically, we present a general description of common thymic lesions and and simulated thymic disease, with an emphasis on PET-CT findings, also incorporating examples of magnetic resonance imaging (MRI).Item RSNA Committee on International Radiology Education: 25 Years of Global Education Outreach(2020-11) Silva, Claudio; Elizondo-Rojas, Guillermo; Atalabi, Omolola; Karçaaltincaba, ltincaba; Morana, Giovanni; Mahmood, UmarThe Radiological Society of North America (RSNA) Committee on International Radiology Education (CIRE) has worked for the past 25 years to create academic programs oriented to the needs of international radiologists. The CIRE develops organized and structured approaches to help build one’s capabilities and increase one’s capacity for professional growth, which then facilitates better patient care. The authors describe the four programs that CIRE is responsible for and introduces its newest initiative, Global Learning Centers, which is planned to start in 2021. RSNA involvement in global radiology education provides opportunities for early, mid-, and late-career radiologists to participate in these programs as students or teachers. The authors describe some of the programs’ success stories and invite readers to become a part of and contribute to the growth of radiologic academic endeavors globally.