RESUMEN
PURPOSE: The use of MRI for radiotherapy planning purposes is growing but image acquisition using radiotherapy set-ups has impaired image quality. Whether differences in image acquisition set-up could modify organ contouring has not been evaluated. Therefore, we aimed to evaluate differences in contouring between paired of image sets that were acquired in the same scanning session using different parameters. MATERIAL AND METHODS: Ten patients underwent RT treatment planning with MRI co-registration. MRI was carried out using two different set-ups during the same session, MRI radiotherapy set-ups and MRI diagnostic set-ups. Prostates and rectums were retrospectively contoured in both image sets by 5 radiation oncologists and 4 radiologists. Intra-observer analysis was carried out comparing organ volumes, the Dice coefficient and hausdorff distance values between two contouring rounds. Inter-observer analysis was carried out by comparing individual contours to a generated STAPLE consensus contour, which is considered the gold standard reference. RESULTS: No significant differences were observed between MRI acquisition set-ups. Significant differences were observed for the dice and hausdorff parameters, comparing individual contours to the STAPLE consensus contour, when analysing diagnostic images between rounds, although raw values were similar. CONCLUSION: Prostate and rectum contours did not differ significantly when using diagnostic or radiotherapy MRI acquisition set-ups.
Asunto(s)
Imagen por Resonancia Magnética/métodos , Próstata/diagnóstico por imagen , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/radioterapia , Recto/diagnóstico por imagen , Algoritmos , Humanos , Masculino , Variaciones Dependientes del Observador , Órganos en Riesgo/diagnóstico por imagen , Oncólogos de Radiación , Radiólogos , Estudios Retrospectivos , Estadísticas no Paramétricas , Flujo de TrabajoRESUMEN
PURPOSE: To quantitatively and qualitatively evaluate and compare MR images acquired from the usual diagnostic set-up with images acquired in a radiotherapy set-up. MATERIALS AND METHODS: MR images of a phantom and 18 prostate cancer patients imaging using the usual diagnostic set-up with a curved tabletop (DX-set-up) and using a radiotherapy set-up (RT-set-up) with a flat tabletop, were analysed retrospectively. Quantitative assessments were made by measuring signal-to-noise ratio (SNR) and contrast to noise ratio (CNR). Non-parametric tests were used. Qualitative assessments were made independently by three radiologists. Inter-rater reliability was measured as the percentage of agreement and Gwet's AC2 test. RESULTS: The use of the RT-set-up was linked to 19.3% SNR drop on the phantom image. Up to 24% SNR prostate drop was observed in patients' images. Up to 34% CNR drop was observed in patients' images. Although image quality of the RT-set-up was acceptable, all measured domains were worse than the corresponding DX-set-up. Additionally diagnostic images were linked to a better percentage of agreement among raters. CONCLUSIONS: SNR, CNR and image quality were significantly worse when using the RT-set-up than with the DX-set-up although Image quality in the RT-set-up was acceptable.
Asunto(s)
Imagen por Resonancia Magnética/métodos , Neoplasias de la Próstata/diagnóstico por imagen , Fibra de Carbono , Equipos y Suministros de Hospitales , Humanos , Masculino , Fantasmas de Imagen , Estudios Retrospectivos , Relación Señal-RuidoAsunto(s)
Músculo Esquelético/lesiones , Músculo Esquelético/inervación , Radiculopatía/etiología , Toxinas Botulínicas Tipo A/uso terapéutico , Electromiografía , Fenómenos Electrofisiológicos , Humanos , Hipertrofia/etiología , Hipertrofia/patología , Pierna/patología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Desnervación Muscular , Músculo Esquelético/patología , Examen Neurológico , Fármacos Neuromusculares/uso terapéutico , Radiculopatía/tratamiento farmacológico , Radiculopatía/patologíaAsunto(s)
Tronco Encefálico , Enfermedades en Gemelos/complicaciones , Leucoencefalopatías/complicaciones , Enfermedades de la Médula Espinal/etiología , Enfermedades en Gemelos/sangre , Femenino , Humanos , Lactante , Lactatos/sangre , Leucoencefalopatías/sangre , Enfermedades de la Médula Espinal/sangreRESUMEN
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