Cuantificación de la concentración del iodo con TC de doble energía en pacientes con pancreatitis aguda / Quantification of iodine concentration by dual-energy CT in patients with acute pancreatitis

OBJETIVO: Determinar si existen diferencias en la concentración de iodo cuantificada con TC de doble energía en el páncreas de pacientes con pancreatitis aguda y pacientes sin signos analíticos ni en imagen de patología pancreática. MATERIAL Y MÉTODOS: Se estudian 27 casos de pancreatitis aguda a los que se realizó una TC con energía dual a las 48-72 horas del inicio de los síntomas, realizada con contraste intravenoso y una sola fase con un retraso de 55 segundos. Se compara con un grupo control de 11 pacientes con una TC realizada con el mismo protocolo, pero sin datos radiológicos de pancreatitis y amilasa y lipasa normales. Mediante posprocesado se obtienen reconstrucciones con mapa de iodo y se realizan tres regiones de interés en cabeza, cuerpo y cola pancreática para obtener los valores de concentración de iodo (mg/ml) y se comparan entre ambos grupos. Se hace un segundo cálculo normalizando la densidad de iodo con la aorta. RESULTADOS:En las pancreatitis, el valor medio de densidad de iodo es 2,5mg/ml. En el grupo de los controles es de 3,65mg/ml (p = 0,02). Hay tres casos con necrosis glandular en los que la densidad de iodo es 1,53mg/ml. CONCLUSIONES: Existen diferencias significativas en la concentración de iodo del páncreas medida en TC con energía dual entre pacientes con pancreatitis aguda en fases iniciales y pacientes sin signos analíticos ni en imagen de patología pancreática

OBJECTIVE: To determine whether pancreatic iodine concentrations quantified by dual-energy CT differ between patients with acute pancreatitis and those without imaging or laboratory findings indicative of pancreatic disease. MATERIAL AND METHODS: We compared findings on single-phase dual-energy CT images acquired 55seconds after the intravenous administration of contrast material in 27 patients with acute pancreatitis who underwent the examination 48 to 72hours after the onset of symptoms versus in 11 patients (controls) with no imaging findings suggestive of pancreatic disease and normal amylase and lipase who underwent the examination with the same protocol for other purposes. Imaging postprocessing included the generation of iodine maps. Three regions of interest were selected (pancreatic head, body, and tail) to obtain iodine concentrations (mg/ml) to compare between groups. Iodine concentrations were also calculated a second time by normalizing the density of iodine with the aorta. RESULTS: The mean density of iodine was 2.5mg/ml in patients with pancreatitis vs. 3.65mg/ml in controls (p = 0.02). In three patients with glandular necrosis, the density of iodine was 1.53mg/ml. CONCLUSIONS: The concentration of iodine in the pancreas measured with dual-energy CT differs significantly between patients with initial-stage acute pancreatitis and those without imaging or laboratory findings indicative of pancreatic disease

Resonancia magnética de conducto auditivo interno: ¿es siempre útil administrar contraste intravenoso? / Inner ear MRI: is it always useful to manage intravenous contrast?

OBJETIVO: Evaluar el valor añadido que aporta administrar contraste intravenoso (CIV) rutinariamente en las resonancias magnéticas (RM) de pacientes con síntomas audiovestibulares en la lectura de un neurorradiólogo y un residente. MATERIAL Y MÉTODOS: Estudio retrospectivo que incluía pacientes que durante 2 meses se realizaron una RM de oídos. Dos radiólogos revisaron las imágenes de forma independiente y cegada. Se realizó una lectura analizando las secuencias adquiridas sin contraste, y posteriormente una segunda lectura analizando todas las secuencias, incluidas las secuencias T1-poscontraste. Se calculó la correlación interobservador y la correlación entre los hallazgos en RM y el motivo de solicitud. RESULTADOS: Se incluyeron 40 pacientes. El rango de edad fue de 36-80 años. El motivo de solicitud más frecuente fue hipoacusia (52,5%). El neurorradiólogo sin CIV encontró un 82,5% de patología extraótica y un 17,5% de patología ótica, entre las que destacaba un neurinoma del VIII par (7,5%); también laberintitis osificante, otosclerosis retrofenestrada y colesteatoma. Tras la administración de CIV, los hallazgos fueron similares. El residente identificó patología ótica en el 5% en las secuencias basales y un 20% usando CIV. La correlación interobservador usando CIV fue excelente (0,97), pero débil sin CIV (0,52). Existió correlación entre los motivos de solicitud y los hallazgos en los oídos, tanto en los protocolos sin CIV (p = 0,004) como en los protocolos con CIV (p = 0,002). CONCLUSIONES: La RM de oídos sin contraste da información relevante para valorar síntomas audiovestibulares. El uso de CIV aumenta el grado de confianza en un radiólogo novel, mientras que en el experto su uso es menos relevante. Se debería plantear un protocolo en el que se use gadolinio en pacientes seleccionados

OBJECTIVE: To evaluate the added value of administering intravenous contrast (IVC) routinely to the MRI of patients with audiovestibular symptoms in the assessment of a neuroradiologist and a resident. MATERIALS AND METHODS: Retrospective study including patients who had an inner ear MRI for two months. Two radiologists reviewed independently and blinded the images. A first assessment was made analyzing just the sequences acquired without contrast and then a second evaluation of all the sequences, including post-contrast T1 sequences. The interobserver correlation and the correlation between MRI findings and the reason for requesting the study were calculated. RESULTS: 40 patients were included. The range age was 36-80 years. The most frequent reason for request the MRI was hearing loss (52.5%). Neuroradiologist without IVC found 82.5% of extraotic pathology and 17.5% of otic pathology, highlighting the neurinoma of the VIII pair (7.5%); ossifying labyrinthitis, retrofenestrated otosclerosis and cholesteatoma. After IVC administration, findings were similar. The resident identified otic pathology in 5% in baseline sequences and 20% using CIV. The interobserver correlation using IVC was excellent (0.97), but weak without IVC (0.52). There was a correlation between the reasons for request the MRI and the findings in the ears, both in protocols without IVC (p = 0.004) and in protocols with IVC (p = 0.002). CONCLUSION: Inner ear MRI without contrast gives relevant information to assess audiovestibular symptoms. The use of IVC increases the degree of confidence in a novel radiologist, while in the expert its use is less relevant. A protocol should be proposed in which gadolinium is used in selected patients

Perforación gastrointestinal por espina de pescado. Hallazgos radiológicos en tomografía computarizada en 58 pacientes / Gastrointestinal perforation caused by ingested fish bone. Computed tomography findings in 58 patients

CONTEXTO Y OBJETIVO: Las espinas de pescado son los cuerpos extraños que con más frecuencia se ingieren accidentalmente y a su vez los que más a menudo causan perforación. El diagnóstico clínico-radiológico es difícil dado que los síntomas son inespecíficos y el paciente no recuerda dicho antecedente. Por ello, en la mayoría de los casos suele ser un diagnóstico laparoscópico o quirúrgico. Nuestro objetivo es describir los signos radiológicos de alarma en tomografía computarizada (TC) para sospechar perforación por espina de pescado y así buscarla y diagnosticarla. MATERIAL Y MÉTODOS: Estudio retrospectivo en el que se examinan 58 pacientes con diagnóstico radiológico de perforación gastrointestinal por espina de pescado. Se seleccionan aquellos pacientes con una TC de abdomen con espina localizada más allá del esófago, todas confirmadas mediante cirugía, estudio endoscópico o control radiológico, desde el año 2007 hasta 2017. Se realiza un análisis descriptivo y se analiza la localización de la perforación y los signos radiológicos sospechosos, como la presencia de un cuerpo extraño lineal hiperdenso, desdibujamiento de la grasa, burbujas de aire extraluminal y complicaciones. Se compara con los hallazgos descritos en la literatura científica. RESULTADOS: De los 58 pacientes, 39 eran hombres y 19 mujeres, con una media de edad de 70 años. La localización más frecuente fue el íleon (20 pacientes). En el 100% existía desdibujamiento de la grasa, el 98% presentaba imagen de cuerpo extraño, el 45% tenía engrosamiento mural y solo el 20% mostraba pequeñas burbujas de aire extraluminal. Quince pacientes presentaban abscesos (tres hepáticos) y sólo cinco tenían neumoperitoneo franco. CONCLUSIONES: La afectación de la grasa alrededor del segmento intestinal perforado por espina de pescado es el hallazgo más frecuente. Por ello, ante un estudio abdominal con afectación aislada de la grasa, es importante que el radiólogo busque la presencia de un cuerpo extraño

CONTEXT AND OBJETIVE: Fish bones (FB) are the most commonly ingested objects and the most common cause of foreign body perforation of the GI tract. Patients present with varied and nonspecific clinical presentations. The inability to obtain a history of FB ingestion and its wide spectrum of nonspecific clinical presentations makes dietary FB perforation extremely difficult to diagnose, being a laparoscopic or surgical diagnosis. The aim of our study is to describe radiological features in CT that will alert you to look for the FB and then make an accurate presurgical diagnosis. MATERIALS AND METHODS: All patients (n=58) with radiological diagnosis of gastrointestinal perforation caused by fish bone detected by CT between 2007 to 2017 were retrospectively reviewed. Inclusion criteria were: fish bone located beyond the esophagus, radiological diagnosis by CT and confirmation by surgery, endoscopy or radiological control. Descriptive analysis was made. Radiological features were studied including radioopaque foreign body, mural thickness, fatty infiltration or extraluminal air bubbles. Also potential complications were assessed. RESULTS: There were 58 patients, 39 men and 19 women, with an average age of 70. Ileon was the most frequent site of perforation (20 patients). 100% showed regional fatty infiltration, 98% included foreign body, 45% had mural thickening and 20% localized extraluminal air bubbles. 15 abscess were found (3 in the liver) and just 5 showed pneumoperitoneum. CONCLUSION: Fatty infiltration is the feature more common. Therefore, if fatty infiltration is seen in isolation radiologist should look for foreign body

¿Se debe incluir la secuencia de susceptibilidad magnética en el protocolo de resonancia magnética cerebral básico? / Should susceptibility-weighted imaging be included in the basic protocol for magnetic resonance imaging of the brain?

OBJETIVO: Analizar el impacto clínico de adquirir la secuencia de susceptibilidad magnética (SWI) de forma rutinaria en los estudios de resonancia magnética (RM) cerebral. MATERIAL Y MÉTODOS: Se lleva a cabo un estudio prospectivo observacional unicéntrico durante 6 meses a pacientes a los que se le realizó una RM cerebral. Los grupos de estudio se establecieron basándose en la información clínica remitida: el grupo 1 de estudio está formado por aquellos pacientes a los que el radiólogo protocolizó la adquisición de la secuencia SWI, y el grupo 2, por aquellos a los que se les realizó la secuencia SWI sin haber sido protocolizada. Se recogen la edad, sexo y factores de riesgo (hipertensión arterial, historia de traumatismo craneal o de malformaciones vasculares intracraneales). Se analizaron los hallazgos en la secuencia de SWI, si estos eran visibles en el resto de las secuencias y si su identificación suponía cambios sustanciales en el informe radiológico del paciente. RESULTADOS: El grupo 1 estaba formado por 62 pacientes y el grupo 2, por 79. No hubo diferencias al comparar la edad y los factores de riesgo entre los dos grupos. En el grupo 1, los hallazgos de la SWI supusieron un cambio en el informe radiológico en el 34% de los pacientes, y en el grupo 2, en un 14%: las diferencias fueron estadísticamente significativas. CONCLUSIÓN: La secuencia SWI puede ayudar al radiólogo a detectar hallazgos adicionales a las secuencias convencionales en la RM cerebral, que en algunos casos suponen un cambio en el informe radiológico

OBJECTIVE: To analyze the clinical impact of routine acquisition of susceptibility-weighted imaging (SWI) in magnetic resonance imaging (MRI) studies of the brain. MATERIAL AND METHODS: This prospective observational study included all patients undergoing brain MRI including SWI during a 6-month period. Patients were divided into two groups based on the clinical information provided: Group 1 comprised patients in whom SWI acquisition formed part of the brain MRI protocol, and Group comprised patients who underwent SWI without these sequences being included in the protocol. We recorded patients' age, sex, and risk factors (hypertension, history of brain trauma or intracranial vascular malformations). We analyzed the SWI findings, whether these findings were visible on the other sequences, and whether identifying these findings resulted in substantial changes to the radiological report. RESULTS: There were 62 patients in Group 1 and 79 in Group 2. The groups were similar in age and risk factors. SWI findings resulted in substantial changes to the radiological report in 34% of the patients in Group 1 and in 14% of those in Group 2; this difference was statistically significant. CONCLUSION: SWI can help radiologists detect findings not seen on conventional brain MRI that sometimes result in substantial changes to the radiological report

Gastrointestinal perforation caused by ingested fish bone. Computed tomography findings in 58 patients. / Perforación gastrointestinal por espina de pescado. Hallazgos radiológicos en tomografía computarizada en 58 pacientes.

CONTEXT AND OBJETIVE: Fish bones (FB) are the most commonly ingested objects and the most common cause of foreign body perforation of the GI tract. Patients present with varied and nonspecific clinical presentations. The inability to obtain a history of FB ingestion and its wide spectrum of nonspecific clinical presentations makes dietary FB perforation extremely difficult to diagnose, being a laparoscopic or surgical diagnosis. The aim of our study is to describe radiological features in CT that will alert you to look for the FB and then make an accurate presurgical diagnosis. MATERIALS AND METHODS: All patients (n=58) with radiological diagnosis of gastrointestinal perforation caused by fish bone detected by CT between 2007 to 2017 were retrospectively reviewed. Inclusion criteria were: fish bone located beyond the esophagus, radiological diagnosis by CT and confirmation by surgery, endoscopy or radiological control. Descriptive analysis was made. Radiological features were studied including radioopaque foreign body, mural thickness, fatty infiltration or extraluminal air bubbles. Also potential complications were assessed. RESULTS: There were 58 patients, 39 men and 19 women, with an average age of 70. Ileon was the most frequent site of perforation (20 patients). 100% showed regional fatty infiltration, 98% included foreign body, 45% had mural thickening and 20% localized extraluminal air bubbles. 15 abscess were found (3 in the liver) and just 5 showed pneumoperitoneum. CONCLUSION: Fatty infiltration is the feature more common. Therefore, if fatty infiltration is seen in isolation radiologist should look for foreign body.

Inner ear MRI: is it always useful to manage intravenous contrast? / Resonancia magnética de conducto auditivo interno: ¿es siempre útil administrar contraste intravenoso?

OBJECTIVE: To evaluate the added value of administering intravenous contrast (IVC) routinely to the MRI of patients with audiovestibular symptoms in the assessment of a neuroradiologist and a resident. MATERIALS AND METHODS: Retrospective study including patients who had an inner ear MRI for two months. Two radiologists reviewed independently and blinded the images. A first assessment was made analyzing just the sequences acquired without contrast and then a second evaluation of all the sequences, including post-contrast T1 sequences. The interobserver correlation and the correlation between MRI findings and the reason for requesting the study were calculated. RESULTS: 40 patients were included. The range age was 36-80 years. The most frequent reason for request the MRI was hearing loss (52.5%). Neuroradiologist without IVC found 82.5% of extraotic pathology and 17.5% of otic pathology, highlighting the neurinoma of the VIII pair (7.5%); ossifying labyrinthitis, retrofenestrated otosclerosis and cholesteatoma. After IVC administration, findings were similar. The resident identified otic pathology in 5% in baseline sequences and 20% using CIV. The interobserver correlation using IVC was excellent (0.97), but weak without IVC (0.52). There was a correlation between the reasons for request the MRI and the findings in the ears, both in protocols without IVC (p = 0.004) and in protocols with IVC (p = 0.002). CONCLUSION: Inner ear MRI without contrast gives relevant information to assess audiovestibular symptoms. The use of IVC increases the degree of confidence in a novel radiologist, while in the expert its use is less relevant. A protocol should be proposed in which gadolinium is used in selected patients.

Quantification of iodine concentration by dual-energy CT in patients with acute pancreatitis. / Cuantificación de la concentración del iodo con TC de doble energía en pacientes con pancreatitis aguda.

OBJECTIVE: To determine whether pancreatic iodine concentrations quantified by dual-energy CT differ between patients with acute pancreatitis and those without imaging or laboratory findings indicative of pancreatic disease. MATERIAL AND METHODS: We compared findings on single-phase dual-energy CT images acquired 55seconds after the intravenous administration of contrast material in 27 patients with acute pancreatitis who underwent the examination 48 to 72hours after the onset of symptoms versus in 11 patients (controls) with no imaging findings suggestive of pancreatic disease and normal amylase and lipase who underwent the examination with the same protocol for other purposes. Imaging postprocessing included the generation of iodine maps. Three regions of interest were selected (pancreatic head, body, and tail) to obtain iodine concentrations (mg/ml) to compare between groups. Iodine concentrations were also calculated a second time by normalizing the density of iodine with the aorta. RESULTS: The mean density of iodine was 2.5mg/ml in patients with pancreatitis vs. 3.65mg/ml in controls (p = 0.02). In three patients with glandular necrosis, the density of iodine was 1.53mg/ml. CONCLUSIONS: The concentration of iodine in the pancreas measured with dual-energy CT differs significantly between patients with initial-stage acute pancreatitis and those without imaging or laboratory findings indicative of pancreatic disease.

Should susceptibility-weighted imaging be included in the basic protocol for magnetic resonance imaging of the brain? / ¿Se debe incluir la secuencia de susceptibilidad magnética en el protocolo de resonancia magnética cerebral básico?

OBJECTIVE: To analyze the clinical impact of routine acquisition of susceptibility-weighted imaging (SWI) in magnetic resonance imaging (MRI) studies of the brain. MATERIAL AND METHODS: This prospective observational study included all patients undergoing brain MRI including SWI during a 6-month period. Patients were divided into two groups based on the clinical information provided: Group 1 comprised patients in whom SWI acquisition formed part of the brain MRI protocol, and Group comprised patients who underwent SWI without these sequences being included in the protocol. We recorded patients' age, sex, and risk factors (hypertension, history of brain trauma or intracranial vascular malformations). We analyzed the SWI findings, whether these findings were visible on the other sequences, and whether identifying these findings resulted in substantial changes to the radiological report. RESULTS: There were 62 patients in Group 1 and 79 in Group 2. The groups were similar in age and risk factors. SWI findings resulted in substantial changes to the radiological report in 34% of the patients in Group 1 and in 14% of those in Group 2; this difference was statistically significant. CONCLUSION: SWI can help radiologists detect findings not seen on conventional brain MRI that sometimes result in substantial changes to the radiological report.

Nódulo pulmonar incidental: caracterización y manejo / Incidental pulmonary nodules: characterization and management

En esta actualización se aborda el manejo de los nódulos pulmonares, solitarios o múltiples, detectados incidentalmente en estudios radiológicos que se realizan por otros motivos. Se describe la técnica de tomografía computarizada más adecuada para su evaluación, y cómo se clasifican y se miden los diferentes tipos de nódulos. También se revisan los criterios que permiten establecer el riesgo de malignidad, tanto asociados al paciente como a las características del nódulo, y, por último, las recomendaciones de manejo y seguimiento para cada tipo de nódulo en función del tamaño y el riesgo de malignidad, siguiendo fundamentalmente las guías recientemente publicadas por la Sociedad Fleischner

This update covers the management of solitary or multiple pulmonary nodules detected incidentally in imaging studies done for other reasons. It describes the most appropriate computed tomography technique for the evaluation of these nodules, how they are classified, and how the different types of nodules are measured. It also reviews the patient-related and nodule-related criteria for determining the risk of malignancy. It discusses the recommendations in the guidelines recently published by the Fleischner Society for the management and follow-up of each type of nodules according to its size and risk of malignancy

Seudocavitación en las neoplasias de pulmón. ¿Permite predecir el diagnóstico de adenocarcinoma con crecimiento lepídico? / Can pseudocavitation in lung tumors predict the diagnosis of adenocarcinoma with lepidic growth?

OBJETIVO: Evaluar la prevalencia de seudocavitación en las neoplasias de pulmón y si permite predecir el diagnóstico del adenocarcinoma con crecimiento lepídico. MATERIAL Y MÉTODOS: Revisión retrospectiva de las tomografías computarizadas (TC) de tórax de 212 neoplasias de pulmón consecutivas incluidas en una base de datos de perfusión por TC y de 351 adenocarcinomas consecutivos diagnosticados entre julio de 2007 y septiembre de 2017. Dos radiólogos recogieron la presencia o ausencia de quistes aéreos en el tumor sin conocer los resultados de anatomía patológica, excluyendo las lesiones con necrosis, rodeadas de bullas o enfisema. Se analizó si la presencia de seudocavitación tenía relación con el tipo histológico, el tamaño de la lesión y la positividad para el receptor del factor de crecimiento epidérmico (EGFR) del tumor, la edad y el sexo del paciente. También se valoró la relación con el subtipo histológico del adenocarcinoma en aquellos pacientes sometidos a cirugía. Se utilizó la prueba de la χ2 para variables cualitativas y el modelo de regresión logística para variables cuantitativas. RESULTADOS: El 15% de las neoplasias presentaron seudocavitación, que fue significativamente más frecuente en los adenocarcinomas (24,1%), p = 0,003, si bien también se observó en el 9,8% de los carcinomas epidermoides y en el 3% de los carcinomas microcíticos. Presentó una especificidad del 92,4% para predecir el diagnóstico del adenocarcinoma, con una sensibilidad del 24%, un valor predictivo positivo (VPP) del 73,3%, un valor predictivo negativo del 58,4% y una precisión del 37,6%. En los adenocarcinomas resecados, el 65% de los tumores con seudocavitación presentaron crecimiento lepídico con una prevalencia del 40,6% en lepídicos, 31,5% en acinares y 33% en papilares. Fue significativamente más frecuente en mujeres (29%) y no se encontraron diferencias en función de la edad, tamaño y positividad para EGFR. CONCLUSIONES: La seudocavitación es más frecuente en los adenocarcinomas con crecimiento lepídico y en mujeres

OBJECTIVE: To determine the prevalence of pseudocavitation in lung tumors and whether its presence makes it possible to predict the diagnosis of adenocarcinoma with lepidic growth. MATERIAL AND METHODS: We retrospectively reviewed chest CT studies for 212 consecutive lung tumors included in a CT perfusion database and for 351 consecutive adenocarcinomas diagnosed between July 2007 and September 2017. Two radiologists blinded to the pathology report determined whether air cysts were present in the tumors, excluding lesions with necrosis and those surrounded by bullae or emphysema. We analyzed whether the presence of pseudocavitation was associated with the histologic type, size, or EGFR positivity of the tumor as well as with the age or sex of the patient. We also evaluated the relationship with the histologic subtype of the tumor in patients who underwent surgery. We used the chi-square test for categorical variables and logistic regression for continuous variables. RESULTS: Pseudocavitation was present in 15% of the tumors and was significantly more common in adenocarcinomas (24.1%), p = 0.003, although it was also observed in 9.8% of the epidermoid carcinomas and in 3% of the microcytic carcinomas. For the diagnosis of adenocarcinoma, the presence of pseudocavitation yielded 92.4% specificity, 24% sensitivity, 73.3% PPV, 58.4% NPV, and 37.6% accuracy. In the resected adenocarcinomas, 65% of the tumors with pseudocavitation had lepidic growth; the prevalence of pseudocavitation was 40.6% in tumors with lepidic growth, 31.5% in those with acinar growth, and 33% in those with papillary growth. Pseudocavitation was significantly more common in women (29%); no differences were found with respect to age, size, or EGFR positivity. CONCLUSIONS: Pseudocavitation is more common in adenocarcinomas with lepidic growth and in women

Incidental pulmonary nodules: characterization and management. / Nódulo pulmonar incidental: caracterización y manejo.

This update covers the management of solitary or multiple pulmonary nodules detected incidentally in imaging studies done for other reasons. It describes the most appropriate computed tomography technique for the evaluation of these nodules, how they are classified, and how the different types of nodules are measured. It also reviews the patient-related and nodule-related criteria for determining the risk of malignancy. It discusses the recommendations in the guidelines recently published by the Fleischner Society for the management and follow-up of each type of nodules according to its size and risk of malignancy.

Can pseudocavitation in lung tumors predict the diagnosis of adenocarcinoma with lepidic growth? / Seudocavitación en las neoplasias de pulmón. ¿Permite predecir el diagnóstico de adenocarcinoma con crecimiento lepídico?

OBJECTIVE: To determine the prevalence of pseudocavitation in lung tumors and whether its presence makes it possible to predict the diagnosis of adenocarcinoma with lepidic growth. MATERIAL AND METHODS: We retrospectively reviewed chest CT studies for 212 consecutive lung tumors included in a CT perfusion database and for 351 consecutive adenocarcinomas diagnosed between July 2007 and September 2017. Two radiologists blinded to the pathology report determined whether air cysts were present in the tumors, excluding lesions with necrosis and those surrounded by bullae or emphysema. We analyzed whether the presence of pseudocavitation was associated with the histologic type, size, or EGFR positivity of the tumor as well as with the age or sex of the patient. We also evaluated the relationship with the histologic subtype of the tumor in patients who underwent surgery. We used the chi-square test for categorical variables and logistic regression for continuous variables. RESULTS: Pseudocavitation was present in 15% of the tumors and was significantly more common in adenocarcinomas (24.1%), p=0.003, although it was also observed in 9.8% of the epidermoid carcinomas and in 3% of the microcytic carcinomas. For the diagnosis of adenocarcinoma, the presence of pseudocavitation yielded 92.4% specificity, 24% sensitivity, 73.3% PPV, 58.4% NPV, and 37.6% accuracy. In the resected adenocarcinomas, 65% of the tumors with pseudocavitation had lepidic growth; the prevalence of pseudocavitation was 40.6% in tumors with lepidic growth, 31.5% in those with acinar growth, and 33% in those with papillary growth. Pseudocavitation was significantly more common in women (29%); no differences were found with respect to age, size, or EGFR positivity. CONCLUSIONS: Pseudocavitation is more common in adenocarcinomas with lepidic growth and in women.

Utilidad de la tomografía computarizada de energía dual en la reducción del artefacto metálico generado por clips y coils intracraneales / The utility of dual-energy CT for metal artifact reduction from intracranial clipping and coiling

Objetivo: Evaluar la capacidad de la TC de energía dual (TCED) para reducir el artefacto metálico en pacientes con clips y coils intracraneales en estudios de angio-TC cerebral, y analizar el diferente impacto que dicha reducción tiene en función del tipo de dispositivo estudiado. Material y métodos: Se analizaron retrospectivamente 13 pacientes (6 clips, 7 coils). Se obtuvieron imágenes virtuales monoenergéticas (IVM) en un rango de 40 a 150 keV. Se midió el ruido dentro del área de máximo artefacto. La evaluación subjetiva del ruido fue realizada independientemente por dos radiólogos. Las diferencias encontradas se evaluaron mediante el test ANOVA. El test Mann-Whitney se utilizó para comparar las diferencias entre clips y coils. Se determinó el grado de concordancia interobservador (coeficiente κ). Resultados: El ruido fue más bajo en los niveles energéticos más altos (p < 0,05). El ruido fue mayor en pacientes con coils (p < 0,001). La correlación interobservador fue buena (κ = 0,72). Conclusiones: El uso de TCED con reconstrucciones virtuales monoenergéticas ayuda a minimizar el artefacto producido por clips y coils intracraneales en estudios de angio-TC cerebral. La reduccción del artefacto conseguida es mayor en el grupo de pacientes con clips que en el grupo de pacientes con coils

Objective: To assess the ability of dual-energy CT (DECT) to reduce metal-related artifacts in patients with clips and coils in head CT angiography, and to analyze the differences in this reduction between both type of devices. Materials and methods: Thirteen patients (6 clips, 7 coils) were selected and retrospectively analized. Virtual monoenergetic images (MEI) with photon energies from 40 to 150 keV were obtained. Noise was measured at the area of maximum artifact. Subjective evaluation of streak artifact was performed by two radiologists independently. Differences between noise values in all groups were tested by using the ANOVA test. Mann-Whitney U test was used to compare the differences between clips and coils. Cohen??s κ statistic was used to determine interobserver agreement. Results: The lowest noise value was observed at high energy levels (p<0,05). Noise was higher in the coil group than in the clip group (p<0.001). Interobserver agreement was good (κ=0.72). Conclusions: TCED with MEI helps to minimize the artifact from clips ands coils in patients who undergo head CT angiography. The reduction of the artifact is greater in patients with surgical clipping than in patients with endovascular coiling

Valor de la enterografía por tomografía computarizada con doble energía en el análisis de segmentos intestinales patológicos en pacientes con enfermedad de Crohn / Value of dual-energy CT enterography in the analysis of pathological bowel segments in patients with Crohn's disease

Objetivo: Analizar si existen diferencias significativas en los parámetros cuantitativos obtenidos en el posprocesado de estudios con enterografía por tomografía computarizada (entero-TC) de doble energía entre segmentos intestinales con signos radiológicos de enfermedad de Crohn (EC) y segmentos radiológicamente normales. Material y métodos: Estudio retrospectivo en el que se analizan 33 pacientes con EC conocida (16 hombres y 17 mujeres), con una media de edad de 54 años. Se seleccionan aquellos con una entero-TC con protocolo de doble energía. Todas las exploraciones están realizadas con una solución de sorbitol oral y contraste intravenoso en fase portal. Mediante técnicas de posprocesado de las imágenes adquiridas con doble energía se obtienen mapas de color (mapas de yodo). Sobre estos mapas de color, mediante la realización de regiones de interés se cuantifican en cada paciente la densidad de yodo (mg/ml) y la fracción de grasa (%) de la pared de un segmento intestinal patológico con signos radiológicos de EC y de un segmento sano, y se analiza si existen diferencias entre ambos. Resultados: La cuantificación de yodo en los segmentos sanos es 1,8 (± 0,4) mg/ml, y en los segmentos enfermos es 3,7 (± 0,9) mg/ml (p <0,05). La fracción de grasa presente en la pared de los segmentos sanos es del 32,42% (± 6,5), y en los segmentos afectados es del 22,23% (± 9,4) (p <0,05). Conclusión: Existen diferencias significativas en la cuantificación de la densidad de yodo y la fracción de grasa entre segmentos intestinales con signos radiológicos de EC y segmentos radiológicamente normales

Objective: To analyze whether there are significant differences in the objective quantitative parameters obtained in the postprocessing of dual-energy CT enterography studies between bowel segments with radiologic signs of Crohn's disease and radiologically normal segments. Material and methods: This retrospective study analyzed 33 patients (16 men and 17 women; mean age 54 years) with known Crohn's disease who underwent CT enterography on a dual-energy scanner with oral sorbitol and intravenous contrast material in the portal phase. Images obtained with dual energy were postprocessed to obtain color maps (iodine maps). For each patient, regions of interest were traced on these color maps and the density of iodine (mg/ml) and the fat fraction (%) were calculated for the wall of a pathologic bowel segment with radiologic signs of Crohn's disease and for the wall of a healthy bowel segment; the differences in these parameters between the two segments were analyzed. Results: The density of iodine was lower in the radiologically normal segments than in the pathologic segments [1.8 ± 0.4mg/ml vs. 3.7 ± 0.9mg/ml; p<0.05].The fat fraction was higher in the radiologically normal segments than in the pathologic segments [32.42% ± 6.5 vs. 22.23% ± 9.4; p<0.05]. Conclusion: There are significant differences in the iodine density and fat fraction between bowel segments with radiologic signs of Crohn's disease and radiologically normal segments

The utility of dual-energy CT for metal artifact reduction from intracranial clipping and coiling. / Utilidad de la tomografía computarizada de energía dual en la reducción del artefacto metálico generado por clips y coils intracraneales.

OBJECTIVE: To assess the ability of dual-energy CT (DECT) to reduce metal-related artifacts in patients with clips and coils in head CT angiography, and to analyze the differences in this reduction between both type of devices. MATERIALS AND METHODS: Thirteen patients (6 clips, 7 coils) were selected and retrospectively analized. Virtual monoenergetic images (MEI) with photon energies from 40 to 150 keV were obtained. Noise was measured at the area of maximum artifact. Subjective evaluation of streak artifact was performed by two radiologists independently. Differences between noise values in all groups were tested by using the ANOVA test. Mann-Whitney U test was used to compare the differences between clips and coils. Cohens κ statistic was used to determine interobserver agreement. RESULTS: The lowest noise value was observed at high energy levels (p<0,05). Noise was higher in the coil group than in the clip group (p<0.001). Interobserver agreement was good (κ=0.72). CONCLUSIONS: TCED with MEI helps to minimize the artifact from clips ands coils in patients who undergo head CT angiography. The reduction of the artifact is greater in patients with surgical clipping than in patients with endovascular coiling.

Value of dual-energy CT enterography in the analysis of pathological bowel segments in patients with Crohn's disease. / Valor de la enterografía por tomografía computarizada con doble energía en el análisis de segmentos intestinales patológicos en pacientes con enfermedad de Crohn.

OBJECTIVE: To analyze whether there are significant differences in the objective quantitative parameters obtained in the postprocessing of dual-energy CT enterography studies between bowel segments with radiologic signs of Crohn's disease and radiologically normal segments. MATERIAL AND METHODS: This retrospective study analyzed 33 patients (16 men and 17 women; mean age 54 years) with known Crohn's disease who underwent CT enterography on a dual-energy scanner with oral sorbitol and intravenous contrast material in the portal phase. Images obtained with dual energy were postprocessed to obtain color maps (iodine maps). For each patient, regions of interest were traced on these color maps and the density of iodine (mg/ml) and the fat fraction (%) were calculated for the wall of a pathologic bowel segment with radiologic signs of Crohn's disease and for the wall of a healthy bowel segment; the differences in these parameters between the two segments were analyzed. RESULTS: The density of iodine was lower in the radiologically normal segments than in the pathologic segments [1.8 ± 0.4mg/ml vs. 3.7 ± 0.9mg/ml; p<0.05]. The fat fraction was higher in the radiologically normal segments than in the pathologic segments [32.42% ± 6.5 vs. 22.23% ± 9.4; p<0.05]. CONCLUSION: There are significant differences in the iodine density and fat fraction between bowel segments with radiologic signs of Crohn's disease and radiologically normal segments.