Brain CT requests from emergency department: Reality.

OBJECTIVES: To evaluate the most common reasons for requesting brain CT studies from the emergency department and to calculate the prevalence of urgent acute pathology on this population group. MATERIAL AND METHODS: We reviewed brain CT studies requested from the emergency department during October and November 2018. We recorded the following variables: age, sex, reason for requesting the study, CT findings, use of contrast agents and reasons for using them, and, in patients who had undergone previous head CT studies, whether the findings had changed. SPSS was used for statistical analyses. RESULTS: A total of 507 urgent brain CT studies were done (41.4% in men, 58.6% in women; mean age, 65.4±20 years). The most common reason for requesting the study was head trauma (40.5%); only 15.6% of these studies showed acute posttraumatic intracranial lesions. The second most common reason was focal neurologic symptoms (16%); only 16% of these studies showed recent ischemic infarcts or acute bleeding. No pathological findings were reported in 43.2% of the studies. The most common abnormal finding was ischemic lesions in small vessels (20%). Space-occupying lesions (both benign and malignant) were found in 3.9% of all patients. CONCLUSIONS: Most brain CT studies requested from the emergency department showed no findings that would modify the management of the patient. Overuse of urgent brain CT increases the radiology department's workload and exposes patients to radiation unnecessarily.

Tomografía computarizada cerebral solicitada desde Urgencias: la realidad / Brain CT requests from emergency department: reality

Objetivos: Evaluar los motivos más frecuentes por los que se solicitan estudios de imagen craneales desde el Servicio de Urgencias y calcular la prevalencia de la patología aguda urgente en este grupo de población. Material y métodos: Se recogieron las tomografías computarizadas (TC) cerebrales solicitadas por el Servicio de Urgencias en los meses de octubre y noviembre de 2018. Se recogieron los siguientes datos: edad, sexo, motivo de solicitud del estudio, hallazgos encontrados en la prueba de imagen, administración de medios de contraste y motivo, y en caso de que el paciente tuviera estudios de imagen craneales previos, reseñar la existencia de cambios. Se utilizó el programa SPSS para hacer el análisis estadístico. Resultados: Se realizaron 507 TC de cerebro urgentes, 41,4% en hombres y 58,6% en mujeres, con una edad media de 65,4±20 años. El motivo de solicitud más frecuente fue el traumatismo craneal (40,5%), y de ellos únicamente el 15,6% presentó patología intracraneal postraumática aguda. El segundo motivo fue sintomatología neurológica focal (16%), de los cuales el 16% presentó infarto isquémico reciente o hemorragia aguda. En cuanto a los hallazgos, el 43,2% de los estudios fueron informados como normales. El hallazgo más frecuentemente encontrado fue lesiones isquémicas de pequeño vaso, en un 20%. En un 3,9% de todos los pacientes se encontraron lesiones ocupantes de espacio, incluyendo lesiones tanto benignas como malignas. Conclusiones: La mayoría de los estudios cerebrales solicitados desde urgencias no muestran patología que modifique el manejo del paciente. La sobreutilización de la TC cerebral urgente sobrecarga los servicios de radiología y somete a la población a radiación innecesaria.(AU)

Objectives: To evaluate the most common reasons for requesting brain CT studies from the emergency department and to calculate the prevalence of urgent acute pathology on this population group. Material and methods: We reviewed brain CT studies requested from the emergency department during October and November 2018. We recorded the following variables: age, sex, reason for requesting the study, CT findings, use of contrast agents and reasons for using them, and, in patients who had undergone previous head CT studies, whether the findings had changed. SPSS was used for statistical analyses. Results: A total of 507 urgent brain CT studies were done (41.4% in men, 58.6% in women; mean age, 65.4±20 years). The most common reason for requesting the study was head trauma (40.5%); only 15.6% of these studies showed acute posttraumatic intracranial lesions. The second most common reason was focal neurologic symptoms (16%); only 16% of these studies showed recent ischemic infarcts or acute bleeding. No pathological findings were reported in 43.2% of the studies. The most common abnormal finding was small vessel disease (20%). Space-occupying lesions (both benign and malignant) were found in 3.9% of all patients. Conclusions: Most brain CT studies requested from the emergency department showed no findings that would modify the management of the patient. Overuse of urgent brain CT increases the radiology department's workload and exposes patients to radiation unnecessarily.(AU)

Ultralow-dose CT of the petrous bone using iterative reconstruction technique, tin filter and high resolution detectors allows an adequate assessment of the petrous bone structures.

OBJECTIVES: To assess image quality and radiation dose in computed tomography (CT) studies of the petrous bone done with a scanner using a tin filter, high-resolution detectors, and iterative reconstruction, and to compare versus in studies done with another scanner without a tin filter using filtered back projection reconstruction. MATERIAL AND METHODS: Thirty two patients (group 1) were acquired with an ultra-low dose CT (32-MDCT, 130kV, tin filter and iterative reconstruction). Images and radiation doses were compared to 36 patients (group 2) acquired in a 16-MDCT (120kV and filtered back-projection). Muscle density, bone density, and background noise were measured. Signal-to-noise ratio (SNR) was calculated. To assess image quality, two independent radiologists subjectively evaluated the visualization of the different structures of the middle and inner ear (0=not visualized, 3=perfectly identified and delimited). Interobserver agreement was calculated. Effective dose at different anatomical levels with the dose-length product was recorded. RESULTS: In the quantitative analysis, there were no significant differences in image noise between the two groups. In the qualitative analysis, a similar or slightly lower subjective score was obtained in the delimitation of different structures of the ossicular chain and cochlea in the 32-MDCT, compared to 16-MDCT, with statistically significant differences. Mean effective dose (±standard deviation) was 0.16±0.04mSv for the 32-MDCT and 1.25±0.30mSv for the 16-MDCT. CONCLUSIONS: The use of scanners with tin filters, high-resolution detectors, and iterative reconstruction allows to obtain images with adequate quality for the evaluation of the petrous bone structures with ultralow doses of radiation (0.16±0.04mSv).

La tomografía computarizada de peñascos con dosis ultrabaja, utilizando filtro de estaño, detectores de alta resolución y reconstrucción iterativa, permite una adecuada valoración de las estructuras del peñasco / Evaluation of the petrous part of the temporal bone using ultralow-dose computed tomography with a tin filter, high-resolution detectors, and iterative reconstruction

Objetivos: Valorar la calidad de imagen y la dosis de radiación en tomografía computarizada (TC) de peñascos adquiridos con una TC multidetector (TCMD) con filtro de estaño, detectores de alta resolución y reconstrucción iterativa, comparándola con otro equipo sin filtro de estaño y con reconstrucción por retroproyección filtrada. Material y métodos: Se incluyeron retrospectivamente 32 pacientes con TC de peñascos, realizadas con dosis ultrabaja en una 32-TCMD (130 kV con filtro de estaño y reconstrucción iterativa). Se compararon con 36 estudios realizados en una 16-TCMD (120 kV y retroproyección filtrada). Se cuantificó la densidad muscular, ósea y el ruido de fondo, y se calculó la relación señal/ruido. Para valorar la calidad de imagen, dos radiólogos evaluaron de forma subjetiva e independiente la visualización de las diferentes estructuras del oído (0=no se visualiza; 3=se identifica y delimita perfectamente). Se calculó el coeficiente de concordancia interobservador kappa. Utilizando un software comercial, se cuantificó a diferentes niveles anatómicos la dosis efectiva con el producto dosis-longitud. Resultados: En el análisis cuantitativo de las imágenes no se observaron diferencias significativas en el ruido de fondo. En el análisis cualitativo se obtuvo una puntuación subjetiva similar o ligeramente menor en la delimitación de las diferentes estructuras de la cadena osicular y cóclea en la 32-TCMD, con diferencias estadísticamente significativas. La dosis media efectiva fue de 0,16±0,04 mSv para la 32-TCMD frente a 1,25±0,30 mSv para la 16-TCMD. Conclusiones: La utilización de equipos con filtro de estaño, detectores de alta resolución y reconstrucción iterativa permiten obtener TC con dosis de radiación ultrabaja (0,16±0,04 mSv) con una calidad de imagen adecuada para valorar las estructuras de los peñascos.(AU)

Objectives: To compare image quality and radiation dose in computed tomography (CT) studies of the petrous part of the temporal bone done with a scanner using a tin filter, high-resolution detectors, and iterative reconstruction versus in studies done with another scanner without a tin filter using filtered back projection. Material and methods: This retrospective study compared CT studies in 32 patients who underwent ultralow-dose CT of the petrous part of the temporal bone in a 32-detector CT scanner (130 kV with a tin filter and iterative reconstruction) and in 36 patients who underwent the studies in a 16-detector CT scanner (120 kV and filtered back projection). We quantified the densities of muscle and bone tissues and background noise, and we calculated the signal-to-noise ratio. To evaluate image quality, two radiologists working independently subjectively evaluated the visualization of the different structures of the ear on a four-point scale (0=not visible; 3=perfectly identifiable and delimited), and we calculated the coefficient of interobserver concordance (k). Using commercial software, we quantified the effective dose of radiation at different anatomic levels with the dose-length product. Results: In the quantitative analysis, no significant differences were observed in background noise. In the qualitative analysis, the score on the subjective evaluation was similar or slightly lower for the delimitation of the different structures in the ossicular chain and cochlea in the studies done with the 32-detector scanner, with statistically significant differences. The mean effective dose of radiation was 0.16±0.04 mSv for the 32-detector scanner versus 1.25±0.30 mSv for the 16-detector scanner.(AU)

Brain CT requests from emergency department: reality. / Tomografía computarizada cerebral solicitada desde Urgencias: la realidad.

OBJECTIVES: To evaluate the most common reasons for requesting brain CT studies from the emergency department and to calculate the prevalence of urgent acute pathology on this population group. MATERIAL AND METHODS: We reviewed brain CT studies requested from the emergency department during October and November 2018. We recorded the following variables: age, sex, reason for requesting the study, CT findings, use of contrast agents and reasons for using them, and, in patients who had undergone previous head CT studies, whether the findings had changed. SPSS was used for statistical analyses. RESULTS: A total of 507 urgent brain CT studies were done (41.4% in men, 58.6% in women; mean age, 65.4±20 years). The most common reason for requesting the study was head trauma (40.5%); only 15.6% of these studies showed acute posttraumatic intracranial lesions. The second most common reason was focal neurologic symptoms (16%); only 16% of these studies showed recent ischemic infarcts or acute bleeding. No pathological findings were reported in 43.2% of the studies. The most common abnormal finding was small vessel disease (20%). Space-occupying lesions (both benign and malignant) were found in 3.9% of all patients. CONCLUSIONS: Most brain CT studies requested from the emergency department showed no findings that would modify the management of the patient. Overuse of urgent brain CT increases the radiology department's workload and exposes patients to radiation unnecessarily.

Ultralow-dose CT of the petrous bone using iterative reconstruction technique, tin filter and high resolution detectors allows an adequate assessment of the petrous bone structures. / La tomografía computarizada de peñascos con dosis ultrabaja, utilizando filtro de estaño, detectores de alta resolución y reconstrucción iterativa, permite una adecuada valoración de las estructuras del peñasco.

OBJECTIVES: To assess image quality and radiation dose in computed tomography (CT) studies of the petrous bone done with a scanner using a tin filter, high-resolution detectors, and iterative reconstruction, and to compare versus in studies done with another scanner without a tin filter using filtered back projection reconstruction. MATERIAL AND METHODS: Thirty two patients (group 1) were acquired with an ultra-low dose CT (32-MDCT, 130 kV, tin filter and iterative reconstruction). Images and radiation doses were compared to 36 patients (group 2) acquired in a 16-MDCT (120 kV and filtered back-projection). Muscle density, bone density, and background noise were measured. Signal-to-noise ratio (SNR) was calculated. To assess image quality, two independent radiologists subjectively evaluated the visualization of the different structures of the middle and inner ear (0 = not visualized, 3 = perfectly identified and delimited). Interobserver agreement was calculated. Effective dose at different anatomical levels with the dose-length product was recorded. RESULTS: In the quantitative analysis, there were no significant differences in image noise between the two groups. In the qualitative analysis, a similar or slightly lower subjective score was obtained in the delimitation of different structures of the ossicular chain and cochlea in the 32-MDCT, compared to 16-MDCT, with statistically significant differences. Mean effective dose (± standard deviation) was 0.16 ± 0.04 mSv for the 32-MDCT and 1.25 ± 0.30 mSv for the 16-MDCT. CONCLUSIONS: The use of scanners with tin filters, high-resolution detectors, and iterative reconstruction allows to obtain images with adequate quality for the evaluation of the petrous bone structures with ultralow doses of radiation (0.16±0.04 mSv).

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.

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.