The 2021 SIIM-FISABIO-RSNA Machine Learning COVID-19 Challenge: Annotation and Standard Exam Classification of COVID-19 Chest Radiographs.

We describe the curation, annotation methodology, and characteristics of the dataset used in an artificial intelligence challenge for detection and localization of COVID-19 on chest radiographs. The chest radiographs were annotated by an international group of radiologists into four mutually exclusive categories, including "typical," "indeterminate," and "atypical appearance" for COVID-19, or "negative for pneumonia," adapted from previously published guidelines, and bounding boxes were placed on airspace opacities. This dataset and respective annotations are available to researchers for academic and noncommercial use.

Complementary role of magnetic resonance imaging in the study of the fetal urinary system.

Urinary system birth defects represent the abnormality most often detected in prenatal studies, accounting for 30% to 50% of all structural anomalies present at birth. The most common disorders are urinary tract dilation, developmental variants, cystic kidney diseases, kidney tumors, and bladder defects. These anomalies can present in isolation or in association with various syndromes. They are normally evaluated with sonography, and the use of magnetic resonance imaging (MRI) is considered only in inconclusive cases. In this article, we show the potential of fetal MRI as a technique to complement sonography in the study of fetal urinary system anomalies. We show the additional information that MRI can provide in each entity, especially in the evaluation of kidney function through diffusion-weighted sequences.

[Whole-body magnetic resonance imaging in a patient with an occult abdominal neuroblastoma and opsoclonus-myoclonus syndrome]. / Resonancia magnética de cuerpo entero en un caso de neuroblastoma abdominal oculto con síndrome opsoclonus-myoclonus.

Opsoclonus-myoclonus syndrome is a rare neurological disorder. In children, the etiology varies, although it is a paraneoplastic manifestation (mainly of neuroblastoma) in 40% to 80% of cases. Whole-body MRI promises to be a powerful tool in the search for a possible primary tumor in this condition for which the diagnostic algorithm is yet to be established. We present the case of a two-year-old boy with signs of opsoclonus-myoclonus syndrome in whom a retroperitoneal neuroblastoma was detected by whole-body MRI.

[Primary mesenteric extraskeletal osteosarcoma: imaging findings]. / Osteosarcoma extraesquelético mesentérico primario: hallazgos en imagen.

We present a case of extraskeletal osteosarcoma arising from the root of the mesentery. This location is extremely rare; to our knowledge only three other cases have been reported. We describe the findings at computed tomography, positron emission tomography, and bone scintigraphy. We emphasize the radiologic differential diagnosis in this case, which was complicated by the presence of other malignant abdominal disease.

Surgical clips vs. iodine-125 (125I) seeds for marking the location of nonpalpable malignant breast lesions: preliminary results. / Arpón quirúrgico vs. semilla de iodo (125I) en la localización de lesiones no palpables malignas de mama. Resultados preliminares.

OBJECTIVES: To assess the usefulness of iodine-125 (125I) seeds as an alternative to surgical clips for marking the location of nonpalpable malignant breast lesions for surgery. MATERIAL AND METHODS: We included patients with histologically confirmed nonpalpable malignant lesions treated by surgery in 2015 or 2016. Patients were randomly assigned to presurgical marking with metallic clips (Group A) or with 125I seeds (Group B). In both groups, marking was guided by ultrasound and/or mammography depending on the radiologic characteristics of the lesion. During surgery, a gamma probe was used and afterward the presence of seeds in the surgical specimen was checked radiologically. In the histological analysis, the absence of tumor in the stain was considered free margins. We analyzed the following variables: age, lesion characteristics (laterality, mean size on MRI and in the surgical specimen, radiological type), and presence/absence of free margins. RESULTS: In Group A (n=53), the most common histologic subtypes were infiltrating ductal carcinoma (IDC, 84.9%) and luminal A (LA, 49.1%); the mean size of the lesions was 1.8cm. In Group B (n=45), the most common histologic subtypes were IDC (82.2%) and LA (46.5%); the mean size of the lesions was 1.5cm. In Group A, 13.2% had involved margins and 13.2% underwent a second surgical intervention. In Group, B 11.4% had involved margins and 7.5% underwent a second surgical intervention. The differences between groups were not significant (p=0.7 for involved margins and p=0.5 for reintervention). The volume of the surgical specimens was significantly lower in Group B than in Group A (128.68cm3 vs. 189.37cm3; p<0.05). CONCLUSIONS: Using 125I seeds was feasible and enabled significantly smaller surgical specimens than using metallic clips.

Combined procedure of marking axillary positive node with iodine-125 seed and sentinel lymph node biopsy in breast cancer patients treated with neoadjuvant chemotherapy. / Procedimiento combinado de marcaje del ganglio axilar positivo biopsiado con semilla de yodo-125 y biopsia del ganglio centinela en pacientes con cáncer de mama tratadas con quimioterapia neoadyuvante.

OBJECTIVE: To present our initial experience in the combined procedure of intraoperative detection of axillary positive node marked with 125I seed (ML) and sentinel node biopsy (SLN) after neoadjuvant chemotherapy (NACT), in breast cancer patients. MATERIAL AND METHODS: Prospective study, January 2017 - March 2019, 16 breast cancer patients T1-3N1. TNM stage: IIA: 3, IIB: 10, IIIA: 3. Histological type ductal invasive: 14. Molecular subtype: luminal A: 3, luminal B: 9, HER2: 3, basal like: 1. The ML was marked 227±36 days before neoadjuvant chemotherapy (n: 10), or 1-6 days before surgery, on previously identified node by ultrasound visibility marker, hydrogel (n: 3) or three dimensional-3D (n: 3). Axillary lymphadenectomy was undertaken in 10 patients. RESULTS: ML and SLN were identified in the surgery in 93.7% (15/16) of the cases, in 33.3% (5/15) ML was not among SLN, and in only one patient (1/5) was there a discrepancy between the result of ML and SLN (macrometastases vs. negative 0/2). Median number of lymph nodes SLN: 2.2±0.9 (range 1-3) and AD: 13.5±5.2 (range 7-23). In all cases, histopathological analysis of ML, 125I seed and/or marker within, correctly predicted axillary status after neoadjuvant chemotherapy. In all patients the 125I radioactive seed was recovered. CONCLUSIONS: Placing of 125I seeds is a feasible technique for intraoperative location of axillary positive node combined with SLN. The histopathological result of ML allows the axillary status to be determined after neoadjuvant chemotherapy.

Siliconoma mediastínico como complicación de implantes mamarios / Mediastinal siliconoma as a complication of breast implants

No disponible

Localización del ganglio axilar positivo biopsiado mediante semilla 125I tras linfadenectomía en paciente con cáncer de mama / Positive axillary lymph node localization by 125I seed after lymphadenectomy in breast cancer patient

No disponible

Arpón quirúrgico vs. semilla de iodo (125I) en la localización de lesiones no palpables malignas de mama. Resultados preliminares / Surgical clips vs. iodine-125 (125I) seeds for marking the location of nonpalpable malignant breast lesions: preliminary results

OBJETIVOS: Evaluar los resultados de la cirugía radioguiada mediante semillas de 125I como alternativa al arpón quirúrgico en pacientes con lesiones no palpables malignas de mama. MATERIAL Y MÉTODOS: Se incluyeron pacientes con diagnóstico anatomopatológico de cáncer de mama, con lesiones no palpables, candidatas a tratamiento quirúrgico durante 2015-2016. Las pacientes fueron asignadas de manera aleatoria al marcaje prequirúrgico con arpón metálico (grupo A) o con semilla (grupo B). En ambos grupos, el procedimiento fue guiado mediante ecografía y/o mamografía en función de las características de la lesión radiológica. Durante la cirugía se utilizó una sonda gammadetectora y, posteriormente, se comprobó mediante radiología la presencia de las semillas en las piezas quirúrgicas. Se realizó el análisis histológico de las piezas, considerando márgenes libres la ausencia de tumor en la tinta. Las variables analizadas fueron la edad de las pacientes y varias características de la lesión (lateralidad, tamaño medido por resonancia magnética y en la pieza quirúrgica, tipo radiológico y presencia de márgenes quirúrgicos libres). RESULTADOS: En el grupo A (n=53), los subtipos histológicos más frecuentes fueron el carcinoma ductal infiltrante (CDI, 84,9%) y el luminal A (LA, 49,1%); el tamaño medio lesional (TML=1,8cm). En el grupo B (n=45), los resultados fueron CDI=82,2%, LA=46,5%, TML=1,5 cm. En el grupo A, la tasa de márgenes afectados fue del 13,2% y la tasa de reintervenciones, de un 13,2% (p = 0,7), y en el grupo B, la tasa de márgenes afectados fue 11,4% y la tasa de reintervenciones, del 7,5% (p = 0,5). Los volúmenes de las piezas quirúrgicas fueron significativamente menores en el grupo B (V=128,68 cm3) que en el grupo A (V=189,37 cm3) (p <0,05). CONCLUSIONES: La utilización de semillas de 125I se ha mostrado como una técnica factible en la localización de lesiones no palpables de mama, mostrando diferencias significativas en el tamaño de las piezas quirúrgicas respecto al arpón

OBJECTIVES: To assess the usefulness of iodine-125 (125I) seeds as an alternative to surgical clips for marking the location of nonpalpable malignant breast lesions for surgery. MATERIAL AND METHODS: We included patients with histologically confirmed nonpalpable malignant lesions treated by surgery in 2015 or 2016. Patients were randomly assigned to presurgical marking with metallic clips (Group A) or with 125I seeds (Group B). In both groups, marking was guided by ultrasound and/or mammography depending on the radiologic characteristics of the lesion. During surgery, a gamma probe was used and afterward the presence of seeds in the surgical specimen was checked radiologically. In the histological analysis, the absence of tumor in the stain was considered free margins. We analyzed the following variables: age, lesion characteristics (laterality, mean size on MRI and in the surgical specimen, radiological type), and presence/absence of free margins. RESULTS: In Group A (n=53), the most common histologic subtypes were infiltrating ductal carcinoma (IDC, 84.9%) and luminal A (LA, 49.1%); the mean size of the lesions was 1.8cm. In Group B (n=45), the most common histologic subtypes were IDC (82.2%) and LA (46.5%); the mean size of the lesions was 1.5cm. In Group A, 13.2% had involved margins and 13.2% underwent a second surgical intervention. In Group, B 11.4% had involved margins and 7.5% underwent a second surgical intervention. The differences between groups were not significant (p = 0.7 for involved margins and p = 0.5 for reintervention). The volume of the surgical specimens was significantly lower in Group B than in Group A (128.68cm3 vs. 189.37cm3; p < 0.05). CONCLUSIONS: Using 125I seeds was feasible and enabled significantly smaller surgical specimens than using metallic clips

Procedimiento combinado de marcaje del ganglio axilar positivo biopsiado con semilla de yodo-125 y biopsia del ganglio centinela en pacientes con cáncer de mama tratadas con quimioterapia neoadyuvante / Combined procedure of marking axillary positive node with iodine-125 seed and sentinel lymph node biopsy in breast cancer patients treated with neoadjuvant chemotherapy

OBJETIVO: Presentar nuestra experiencia inicial en el procedimiento combinado de detección intraoperatoria del ganglio axilar positivo biopsiado marcado con semilla de 125I (GM) y biopsia del ganglio centinela (GC) después de quimioterapia neoadyuvante, en pacientes con cáncer de mama. MATERIAL Y MÉTODOS: Estudio prospectivo, enero de 2017 - marzo de 2019, 16 pacientes con cáncer de mama T1-3N1. Estadio TNM: II-A: 3, II-B: 10, III-A: 3. Tipo histológico ductal infiltrante: 14. Subtipos moleculares: luminal-A: 3, luminal-B: 9, HER2: 3, triple negativo: 1. El GM se marcó 227+/-36 días antes de iniciar la quimioterapia neoadyuvante (n: 10), o 1-6 días antes de la cirugía, sobre el ganglio previamente identificado con un marcador ecovisible tipo hidrogel (n: 3) o tridimensional-3D (n: 3). En 10 pacientes se realizó linfadenectomía axilar. RESULTADOS: GM y GC se identificaron en la cirugía en el 93,7% (15/16) de los casos, en 33,3% (5/15) GM no se encontraba entre los GC, y solo en una enferma (1/5) existió discrepancia entre el resultado de GM y GC (macrometástasis y negativo 0/2). Número medio ganglios GC: 2,2+/-0,9 (rango 1-3) y linfadenectomía axilar: 13,5+/-5,2 (rango 7-23). En todos los casos, el análisis anatomopatológico del GM, con semilla de 125I y/o marcador, predijo correctamente el estatus axilar posneoadyuvancia. En todas las pacientes se recuperó la semilla radiactiva de 125I. CONCLUSIONES: La colocación de semillas de 125I es una técnica factible para la localización intraoperatoria del ganglio positivo biopsiado en combinación con la biopsia del ganglio centinela. El resultado anatomopatológico del GM permite determinar el estatus axilar posneoadyuvancia

OBJECTIVE: To present our initial experience in the combined procedure of intraoperative detection of axillary positive node marked with 125I seed (ML) and sentinel node biopsy (SLN) after neoadjuvant chemotherapy (NACT), in breast cancer patients. MATERIAL AND METHODS: Prospective study, January 2017 - March 2019, 16 breast cancer patients T1-3N1. TNM stage: IIA: 3, IIB: 10, IIIA: 3. Histological type ductal invasive: 14. Molecular subtype: luminal A: 3, luminal B: 9, HER2: 3, basal like: 1. The ML was marked 227+/-36 days before neoadjuvant chemotherapy (n: 10), or 1-6 days before surgery, on previously identified node by ultrasound visibility marker, hydrogel (n: 3) or three dimensional-3D (n: 3). Axillary lymphadenectomy was undertaken in 10 patients. RESULTS: ML and SLN were identified in the surgery in 93.7% (15/16) of the cases, in 33.3% (5/15) ML was not among SLN, and in only one patient (1/5) was there a discrepancy between the result of ML and SLN (macrometastases vs. negative 0/2). Median number of lymph nodes SLN: 2.2+/-0.9 (range 1-3) and AD: 13.5+/-5.2 (range 7-23). In all cases, histopathological analysis of ML, 125I seed and/or marker within, correctly predicted axillary status after neoadjuvant chemotherapy. In all patients the 125I radioactive seed was recovered. CONCLUSIONS: Placing of 125I seeds is a feasible technique for intraoperative location of axillary positive node combined with SLN. The histopathological result of ML allows the axillary status to be determined after neoadjuvant chemotherapy

Hallazgos radiológicos en ecografía y tomografía computada multidetector de 64 canales de una invaginación colo-cólica secundaria a lipoma / Radiological findings on ultrasonography and multidetector computed tomography of 64 channels of a colo-colonic intussusception secondary to lipoma

Si bien la mayoría de los lipomas intestinales son asintomáticos y se diagnostican de manera casual, en algunas ocasiones pueden tener síntomas, como sangrado, diarrea o, con menor frecuencia, obstrucción o invaginación intestinal. Esta última en el adulto es una patología poco común y por lo general tiene una presentación subaguda crónica, cuyo diagnóstico es complicado. La principal técnica de imagen para el diagnóstico de la invaginación intestinal en adultos es la tomografía computada (TC). Solamente un 20% de las invaginaciones son colo-cólicas y en su mayoría son secundarias a un carcinoma. No obstante, en algunas pocas oportunidades pueden ser secundarias a una causa benigna, siendo el lipoma la más usual.

Even though most of the intestinal lipomas are asymptomatic and are diagnosed by chance, sometimes may have symptoms such as bleeding or diarrhea, and less frequently obstruction or intussusception. Intussusception in adults is a rare condition, and usually has a chronic-subacute presentation, and diagnosis is difficult. CT is the main radiological imaging test for diagnosis. Only 20% of the colonic invaginations are colo-colic, and in most cases are secondary to carcinoma. Rarely are secondary to a benign cause, being the intussusception secondary to a lipoma the most frecuent.

Hallazgos radiológicos en ecografía y tomografía computada multidetector de 64 canales de una invaginación colo-cólica secundaria a lipoma

Si bien la mayoría de los lipomas intestinales son asintomáticos y se diagnostican de manera casual, en algunas ocasiones pueden tener síntomas, como sangrado, diarrea o, con menor frecuencia, obstrucción o invaginación intestinal. Esta última en el adulto es una patología poco común y por lo general tiene una presentación subaguda crónica, cuyo diagnóstico es complicado. La principal técnica de imagen para el diagnóstico de la invaginación intestinal en adultos es la tomografía computada (TC). Solamente un 20% de las invaginaciones son colo-cólicas y en su mayoría son secundarias a un carcinoma. No obstante, en algunas pocas oportunidades pueden ser secundarias a una causa benigna, siendo el lipoma la más usual.(AU)

Even though most of the intestinal lipomas are asymptomatic and are diagnosed by chance, sometimes may have symptoms such as bleeding or diarrhea, and less frequently obstruction or intussusception. Intussusception in adults is a rare condition, and usually has a chronic-subacute presentation, and diagnosis is difficult. CT is the main radiological imaging test for diagnosis. Only 20% of the colonic invaginations are colo-colic, and in most cases are secondary to carcinoma. Rarely are secondary to a benign cause, being the intussusception secondary to a lipoma the most frecuent.(AU)

Papel complementario de la resonancia magnética en el estudio del sistema urinario fetal / Complementary role of magnetic resonance imaging in the study of the fetal urinary system

La patología urinaria es la anomalía que se detecta con mayor frecuencia en el estudio prenatal y representa del 30 al 50% del total de las anomalías estructurales en el nacimiento. Los trastornos más frecuentes son la dilatación del tracto urinario, las variantes del desarrollo, las enfermedades quísticas renales, la patología neoplásica renal y anomalías de la vejiga. Estas entidades pueden presentarse aisladas o asociadas a síndromes. Su evaluación se realiza con ecografía de forma rutinaria, y solo en aquellos casos en los que no sea concluyente se considera el estudio adicional con resonancia magnética (RM) fetal. Nuestro objetivo es exponer el potencial de la RM fetal como complemento a la ecografía en las enfermedades del sistema urinario fetal, analizando sus principales indicaciones y la información adicional que aporta en cada entidad, especialmente en la valoración de la funcionalidad renal mediante las secuencias de difusión (AU)

Urinary system birth defects represent the abnormality most often detected in prenatal studies, accounting for 30% to 50% of all structural anomalies present at birth. The most common disorders are urinary tract dilation, developmental variants, cystic kidney diseases, kidney tumors, and bladder defects. These anomalies can present in isolation or in association with various syndromes. They are normally evaluated with sonography, and the use of magnetic resonance imaging (MRI) is considered only in inconclusive cases. In this article, we show the potential of fetal MRI as a technique to complement sonography in the study of fetal urinary system anomalies. We show the additional information that MRI can provide in each entity, especially in the evaluation of kidney function through diffusion-weighted sequences (AU)

Resonancia magnética de cuerpo entero en un caso de neuroblastoma abdominal oculto con síndrome opsoclonus-myoclonus / Whole-body magnetic resonance imaging in a patient with an occult abdominal neuroblastoma and opsoclonus-myoclonus syndrome

El síndrome opsoclonus-myoclonus es un trastorno neurológico raro. En la infancia su etiología es variable, aunque en un 40-80% de los casos se trata de una manifestación paraneoplásica, principalmente del neuroblastoma. Con un algoritmo diagnóstico controvertido en la búsqueda de un posible tumor primario, la resonancia magnética de cuerpo entero se vislumbra como una poderosa herramienta. Presentamos el caso de un varón de 2 años con manifestaciones de un síndrome opsoclonus-myoclonus al que se detectó un neuroblastoma retroperitoneal mediante esta técnica de imagen (AU)

Opsoclonus-myoclonus syndrome is a rare neurological disorder. In children, the etiology varies, although it is a paraneoplastic manifestation (mainly of neuroblastoma) in 40% to 80% of cases. Whole-body MRI promises to be a powerful tool in the search for a possible primary tumor in this condition for which the diagnostic algorithm is yet to be established. We present the case of a two-year-old boy with signs of opsoclonus-myoclonus syndrome in whom a retroperitoneal neuroblastoma was detected by whole-body MRI (AU)

Osteosarcoma extraesquelético mesentérico primario: hallazgos en imagen / Primary mesenteric extraskeletal osteosarcoma: imaging findings

Presentamos un caso de osteosarcoma extraesquelético originado en la raíz del mesenterio. Esta localización es extremadamente rara; en nuestro conocimiento, se han comunicado en la literatura únicamente otros 3 casos. Describimos los hallazgos en la tomografía computarizada, la tomografía por emisión de positrones y la gammagrafía ósea, haciendo hincapié en el diagnóstico diferencial radiológico en este caso, cuya resolución fue complicada por la concomitancia de otra enfermedad maligna abdominal (AU)

We present a case of extraskeletal osteosarcoma arising from the root of the mesentery. This location is extremely rare; to our knowledge only three other cases have been reported. We describe the findings at computed tomography, positron emission tomography, and bone scintigraphy. We emphasize the radiologic differential diagnosis in this case, which was complicated by the presence of other malignant abdominal disease (AU)