Tomografía computarizada de doble energía: nueva tecnología para la reducción de artefactos de metal / Dual-energy computed tomography: new technology for metal artifacts reduction

Introducción: El objetivo fue explorar la utilidad de la tomografía computarizada de doble energía mediante tecnología de imágenes espectrales gemstone y de un programa destinado a la reducción de artefactos de metal (MARS), para evaluar tejidos periprotésicos, y la interpretabilidad diagnóstica de patologías relacionadas con implantes. Materiales y Métodos: Se comparó la densidad ósea, de partes blandas y de grasa en el tejido periprotésico y en tejido de control sin implante, utilizando un escáner de alta definición de tomografía computarizada de doble energía tanto en imágenes policromáticas convencionales, como en monocromáticas virtuales con MARS, en 80 pacientes con prótesis metálicas en diversas regiones musculoesqueléticas. Se valoró la calidad de imagen y la interpretabilidad diagnóstica mediante la escala de Likert. Resultados: Con imágenes policromáticas hubo diferencias significativas entre el área periprotésica en los tres tejidos respecto a los controles (p <0,0001); sin diferencias significativas utilizando imágenes espectrales monocromáticas virtuales-MARS (hueso p = 0,053, partes blandas p = 0,32 y grasa p = 0,13), con más similitud con el tejido normal. Los niveles de ruido fueron significativamente mayores con imágenes policromáticas (p <0,0001) que con imágenes espectrales monocromáticas virtuales-MARS. Se consideraron no interpretables todas las regiones periprotésicas en las imágenes policromáticas y 11 (9%) en las imágenes espectrales monocromáticas virtuales-MARS. No hubo diferencias significativas en la dosis de radiación comparada con la del grupo control (p = 0,21). Conclusiones: La tomografía computarizada de doble energía puede reducir los artefactos periprotésicos, logrando un significativo incremento en la capacidad de identificar tejidos y la interpretabilidad diagnóstica de posibles patologías relacionadas con implantes. Nivel de Evidencia: II

Introduction: To explore the usefulness of dual energy imaging using gemstone spectral imaging technology and a dedicated software for metal artifact reduction (MARS) for the evaluation of periprosthetic tissues, and to assess image interpretability of implant-related complications. Methods: Signal density measurements were performed in periprosthetic and remote (control) areas in bone, soft tissue, and fat among 80 patients using a high definition scanner. Polychromatic images and virtual monochromatic spectral images with MARS were obtained, and image quality and diagnostic interpretability were evaluated using a Likert scale. Results: Using polychromatic images, the periprosthetic area showed significant differences compared to the remote areas among the three tissue explored (p<0.0001 for all); with no significant differences using virtual monochromatic spectral images-MARS (bone p=0.053, soft tissue p=0.32, fat p=0.13), suggesting similar signal density compared to normal (remote) tissue. Furthermore, periprosthetic polychromatic image noise levels were significantly higher than with virtual monochromatic spectral images-MARS (p<0.0001). All periprosthetic areas were deemed non-interpretable using polychromatic images, compared to 11 (9%) using virtual monochromatic spectral images-MARS. There were no differences in radiation dose compared to control group (p=0.21). Conclusions: Virtual monochromatic spectral images-MARS technology has the ability to reduce periprosthetic artifacts, achieving a significant increase to identify tissues and diagnostic interpretability of complications related to the implants. Level of Evidence: II

Periprosthetic Artifact Reduction Using Virtual Monochromatic Imaging Derived From Gemstone Dual-Energy Computed Tomography and Dedicated Software.

OBJECTIVE: The aim of this study was to explore the usefulness of combined virtual monochromatic imaging and metal artifact reduction software (MARS) for the evaluation of musculoskeletal periprosthetic tissue. METHODS: Measurements were performed in periprosthetic and remote regions in 80 patients using a high-definition scanner. Polychromatic images with and without MARS and virtual monochromatic images were obtained. RESULTS: Periprosthetic polychromatic imaging (PI) showed significant differences compared with remote areas among the 3 tissues explored (P < 0.0001). No significant differences were observed between periprosthetic and remote tissues using monochromatic imaging with MARS (P = 0.053 bone, P = 0.32 soft tissue, and P = 0.13 fat). However, such differences were significant using PI with MARS among bone (P = 0.005) and fat (P = 0.02) tissues. All periprosthetic areas were noninterpretable using PI, compared with 11 (9%) using monochromatic imaging. CONCLUSIONS: The combined use of virtual monochromatic imaging and MARS reduced periprosthetic artifacts, achieving attenuation levels comparable to implant-free tissue.