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)

Strengths, weaknesses, opportunities, and threat analysis of dual-energy CT in head and neck imaging.

Technological development of dual-energy computed tomography (DECT) can play an important role in head and neck area. Multiple innovative applications have evolved, optimizing images, achieving metallic artifact reduction, differentiating materials with better primary tumor delineation, thyroid cartilage and bone invasion. Furthermore, quantification algorithms allow measuring iodine concentration, reflecting the blood supply of a lesion indirectly. DECT enables acquiring images with lower radiation doses and iodine intravenous contrast load to obtain the same CT values.. However, DECT uses ionizing radiation, which does not occur with MRI, and requires long post-processing times. Artifacts on iodine maps may be a potential source of pseudolesions. Besides, photon-counting CT scanners are a promising technique that may displace some DECT advantages. A review analyzing the current status of DECT applied to head and neck imaging from the scope of strengths, weaknesses, opportunities, and threatsanalysis would be very interesting to facilitate a realistic, fact-based, data-driven look of this technique.

Análisis de las fortalezas, oportunidades, debilidades y amenazas de la tomografía computarizada de doble energía en el diagnóstico por la imagen de la cabeza y el cuello / Strengths, weaknesses, opportunities, and threat analysis of dual-energy CT in head and neck imaging

El desarrollo tecnológico de la tomografía computarizada de energía dual (TCED) en el área de la cabeza y el cuello ha supuesto un avance importante, ya que se han desarrollado múltiples aplicaciones para optimizar las imágenes y reducir los artefactos metálicos, así como para diferenciar los materiales, permitiendo una mejor delineación del tumor primario, del cartílago tiroideo y la invasión ósea. Además, los algoritmos de cuantificación permiten medir la concentración de yodo, lo que refleja el flujo de sangre que llega a una lesión de forma indirecta. Permite adquirir imágenes con menores dosis de radiación y menor cantidad de contraste yodado para obtener los mismos valores de TC. Sin embargo, utiliza radiaciones ionizantes y el posprocesamiento de las imágenes consume tiempo, y los artefactos en los mapas de yodo pueden suponer una fuente potencial de pseudolesiones. Además, los escáneres de TC con tecnología de recuento de fotones son una técnica prometedora que puede desplazar algunas de las ventajas de la TCED.Esta revisión hace un análisis de la TCED aplicada a las imágenes de cabeza y cuello desde el ámbito del análisis de las fortalezas, oportunidades, debilidades y amenazas para facilitar una visión realista, basada en datos, de esta técnica.(AU)

Technological development of dual-energy computed tomography (DECT) can play an important role in head and neck area. Multiple innovative applications have evolved, optimizing images, achieving metallic artifact reduction, differentiating materials with better primary tumor delineation, thyroid cartilage and bone invasion. Furthermore, quantification algorithms allow measuring iodine concentration, reflecting the blood supply of a lesion indirectly.DECT enables acquiring images with lower radiation doses and iodine intravenous contrast load to obtain the same CT values. However, DECT uses ionizing radiation, which does not occur with MRI, and requires long post-processing times. Artifacts on iodine maps may be a potential source of pseudolesions. Besides, photon-counting CT scanners are a promising technique that may displace some DECT advantages.A review analyzing the current status of DECT applied to head and neck imaging from the scope of strengths, weaknesses, opportunities, and threatsanalysis would be very interesting to facilitate a realistic, fact-based, data-driven look of this technique.(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).

¿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

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.

La columna poscirugía / The postsurgical spine

El síndrome de la columna operada fallida es la persistencia o la reaparición de dolor tras el tratamiento quirúrgico de la columna. Bajo este término se engloban diversas causas tanto mecánicas como no mecánicas. Las técnicas de imagen son herramientas imprescindibles para el control postquirúrgico y para la valoración de las potenciales complicaciones responsables del fracaso de la cirugía. El objetivo de esta revisión es por una parte que el radiólogo se familiarice con los cambios postquirúrgicos normales y por otra parte que pueda identificar los hallazgos radiológicos patológicos que están traduciendo un síndrome de la columna operada fallida. Para eso es necesario conocer el tipo de cirugía que se ha realizado en cada caso y el tiempo transcurrido desde la intervención. En las técnicas de fusión de la columna vertebral se debe evaluar el grado de fusión ósea, el material de instrumentación (tanto su posición como su integridad), el hueso sobre el que asienta, la interfase entre el implante y el hueso y los segmentos vertebrales que se encuentran adyacentes a la columna instrumentada. En las técnicas descompresivas es importante reconocer qué cambios son los esperables en un paciente operado y saber distinguirlos de la fibrosis peridural y de la recidiva herniaria. También se deben conocer los datos radiológicos de infección postquirúrgica. Se revisarán otras complicaciones, como la aracnoiditis, las colecciones líquidas postquirúrgicas y las alteraciones de los tejidos blandos adyacentes al lecho quirúrgico (AU9

Failed back surgery syndrome is the persistence or reappearance of pain after surgery on the spine. This term encompasses both mechanical and nonmechanical causes. Imaging techniques are essential in postoperative follow-up and in the evaluation of potential complications responsible for failed back surgery syndrome. This review aims to familiarize radiologists with normal postoperative changes and to help them identify the pathological imaging findings that reflect failed back surgery syndrome. To interpret the imaging findings, it is necessary to know the type of surgery performed in each case and the time elapsed since the intervention. In techniques used to fuse the vertebrae, it is essential to evaluate the degree of bone fusion, the material used (both its position and its integrity), the bone over which it lies, the interface between the implant and bone, and the vertebral segments that are adjacent to metal implants. In decompressive techniques it is important to know what changes can be expected after the intervention and to be able to distinguish them from peridural fibrosis and the recurrence of a hernia. It is also crucial to know the imaging findings for postoperative infections. Other complications are also reviewed, including arachnoiditis, postoperative fluid collections, and changes in the soft tissues adjacent to the surgical site (AU)

The postsurgical spine. / La columna poscirugía.

Failed back surgery syndrome is the persistence or reappearance of pain after surgery on the spine. This term encompasses both mechanical and nonmechanical causes. Imaging techniques are essential in postoperative follow-up and in the evaluation of potential complications responsible for failed back surgery syndrome. This review aims to familiarize radiologists with normal postoperative changes and to help them identify the pathological imaging findings that reflect failed back surgery syndrome. To interpret the imaging findings, it is necessary to know the type of surgery performed in each case and the time elapsed since the intervention. In techniques used to fuse the vertebrae, it is essential to evaluate the degree of bone fusion, the material used (both its position and its integrity), the bone over which it lies, the interface between the implant and bone, and the vertebral segments that are adjacent to metal implants. In decompressive techniques it is important to know what changes can be expected after the intervention and to be able to distinguish them from peridural fibrosis and the recurrence of a hernia. It is also crucial to know the imaging findings for postoperative infections. Other complications are also reviewed, including arachnoiditis, postoperative fluid collections, and changes in the soft tissues adjacent to the surgical site.

Comparación de la calidad de imagen y dosis de radiación en angio-tomografía computarizada de arterias periféricas con 80 y 100 kV / Comparison of image quality and radiation dose in computed tomography angiography of the peripheral arteries using tube voltage of 80 kV versus 100 kV

Objetivo. Comparar la calidad de imagen y la dosis de radiación en 2 grupos de pacientes a los que se realiza angio-TC de extremidades inferiores con 80 y 100 kV. Material y métodos. Se realizó angio-TC de miembros inferiores a 60 pacientes con sospecha de enfermedad arterial periférica aleatorizados en 2 grupos, en uno la TC se realizó con 80 kV y en el otro con 100 kV. Los demás parámetros de adquisición se mantuvieron constantes. Se analizaron las imágenes cuantificando la densidad vascular (DV) y el ruido (R), y se calcularon los cocientes densidad vascular/ruido (CDVR) y contraste/ruido (CCR). Dos radiólogos evaluaron independientemente la calidad subjetiva de las imágenes. Se calculó la dosis efectiva estimada (DEE) basada en el producto dosis-longitud (DLP). Resultados. El grupo de 80 kV presentó valores significativamente más elevados de la DV (462,5 UH ± 95,6 vs. 372 UH ± 100,9; p < 0,001) y del CDVR (241,9 ± 48,1 vs. 194,3 ± 49,6; p < 0,001) y diferencias no significativas del R (21,3 UH ± 13 vs. 16,3 UH ± 3,5; p = 0,098) y el CCR (21,4 ± 12,1 vs. 22,9 ± 9,1; p = 0,15). No hubo diferencias significativas en la calidad subjetiva de la imagen y la dosis efectiva fue significativamente menor en el grupo de 80 kV (4,73 mSv ± 1,1 vs. 9,6 mSv ± 2,2; p < 0,001). Conclusión. La utilización de 80 kV en el estudio de angio-TC de miembros inferiores disminuye la dosis de radiación sin afectar a la eficacia diagnóstica del estudio respecto a la utilización de 100 kV (AU)

Objective. To compare the image quality and dose of radiation in two groups of patients undergoing CT angiography of the lower limbs, one with tube voltage of 80 kV and the other with tube voltage of 100 kV. Material and methods. We performed CT angiography of the lower limbs in 60 patients with suspected peripheral arterial disease. Patients were randomly assigned to one of two groups; in one group, CT angiography was performed using a tube voltage of 80 kV, whereas in the other it was performed using 100 kV. The remaining acquisition parameters were the same in both groups. The images were analyzed by quantifying vascular density (VD) and noise (N) and by calculating the quotients density/noise (QVDN) and contrast/noise (QCN). Two radiologists working independently evaluated the subjective quality of the images. We calculated the estimated effective dose (EED) based on the dose-length product (DLP). Results. In the group studied at 80 kV, VD was significantly higher (462.5 UH ± 95.6 vs. 372 UH ± 100.9; P <. 001), QVDN was significantly higher (241.9 ± 48.1 vs. 194.3 ± 49.6; P < .001), and there were trends toward higher N (21.3 UH ± 13 vs. 16.3 UH ± 3.5; P = .098) and toward higher QCN (21.4 ± 12.1 vs. 22.9 ± 9.1; P = .15). No significant differences were found in the subjective quality of the images. The EED was significantly lower in the group studied at 80 kV (4.73 mSv ± 1.1 vs. 9.6 mSv ± 2.2; P <. 001). Conclusion. Using 80 kV instead of 100 kV for CT angiography of the lower limbs reduces the dose of radiation without affecting the diagnostic efficacy of the study (AU)

Comparison of image quality and radiation dose in computed tomography angiography of the peripheral arteries using tube voltage of 80 kV versus 100 kV.

OBJECTIVE: To compare the image quality and dose of radiation in two groups of patients undergoing CT angiography of the lower limbs, one with tube voltage of 80 kV and the other with tube voltage of 100 kV. MATERIAL AND METHODS: We performed CT angiography of the lower limbs in 60 patients with suspected peripheral arterial disease. Patients were randomly assigned to one of two groups; in one group, CT angiography was performed using a tube voltage of 80kV, whereas in the other it was performed using 100 kV. The remaining acquisition parameters were the same in both groups. The images were analyzed by quantifying vascular density (VD) and noise (N) and by calculating the quotients density/noise (QVDN) and contrast/noise (QCN). Two radiologists working independently evaluated the subjective quality of the images. We calculated the estimated effective dose (EED) based on the dose-length product (DLP). RESULTS: In the group studied at 80 kV, VD was significantly higher (462.5 UH ± 95.6 vs. 372 UH ± 100.9; P<.001), QVDN was significantly higher (241.9 ± 48.1 vs. 194.3 ± 49.6; P<.001), and there were trends toward higher N (21.3 UH ± 13 vs. 16.3 UH ± 3.5; P=.098) and toward higher QCN (21.4 ± 12.1 vs. 22.9 ± 9.1; P=.15). No significant differences were found in the subjective quality of the images. The EED was significantly lower in the group studied at 80 kV (4.73 mSv ± 1.1 vs. 9.6 mSv ± 2.2; P<.001). CONCLUSION: Using 80 kV instead of 100 kV for CT angiography of the lower limbs reduces the dose of radiation without affecting the diagnostic efficacy of the study.