RESUMEN
OBJECTIVES: To evaluate the feasibility of coronary computed tomography angiography (CCTA) in patients with free-breathing using 16-cm z-coverage CT with motion correction algorithm. METHODS: 616 patients underwent CCTA without heart rate control. 325 examinations were performed during breath-holding (group A), and the remaining 291 were performed during free-breathing (group B). The image quality scores were defined as 1 (excellent), 2 (good), 3 (adequate), and 4 (poor). 22 patients in group A and 24 in group B underwent invasive coronary angiography (ICA) after CCTA within two weeks. The image quality score, diagnostic accuracy using ICA as reference, signal-to-noise ratio (SNR), and effective dose (ED) were compared between the two groups. RESULTS: Mean heart rate during scanning was 70.8⯱â¯13.8 bpm in group A and 70.7⯱â¯13.2 bpm in group B (Pâ¯=â¯.950). No significant differences were observed in SNR and image quality score (1.49⯱â¯0.62 vs. 1.53⯱â¯0.67; Pâ¯=â¯.647) between the breath-holding and free-breathing groups. ED (1.99⯱â¯0.83 â¯mSv vs. 2.01⯱â¯0.88 â¯mSv) was not significantly different between the two groups (Pâ¯=â¯.975). In a segment-based analysis, the sensitivity, specificity and diagnostic accuracy in the detection of coronary stenosis of more than 50% were 82.1%, 96.8% and 92.2%, respectively in the breath-holding group and 82.2%, 96.6% and 92.2%, respectively in the free-breathing group with no significant differences for these parameters between the two groups. CONCLUSIONS: CCTA for patients without heart rate control and during free-breathing using 16-cm z-coverage CT with motion correction algorithm showed no significant difference in image quality and diagnostic performance compared with CCTA during breath-holding.
Asunto(s)
Algoritmos , Angiografía por Tomografía Computarizada/métodos , Angiografía Coronaria/métodos , Enfermedad Coronaria/diagnóstico por imagen , Frecuencia Cardíaca , Tomografía Computarizada Multidetector/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Respiración , Anciano , Contencion de la Respiración , Enfermedad Coronaria/fisiopatología , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Movimientos de los Órganos , Valor Predictivo de las Pruebas , Estudios ProspectivosRESUMEN
To evaluate the clinical value of virtual monochromatic spectral (VMS) images with metal artifact reduction (MAR) algorithm in dual-energy computed tomography (DECT)-guided microcoil localization of pulmonary nodules.Fifty-one patients underwent DECT after placement of microcoils on small pulmonary nodules before video-assisted thoracoscopic surgery (VATS). Optimal energy level (in keV) was defined as the level at which CT values of nodules were equivalent to those of 120 kVp images and with no serious metal artifacts. VMS images at optimal keV and at 50, 90,110, and 140âkeV with and without MAR were reconstructed. Image quality was scored using a 3-point scale: 1â=âexcellent, minimal artifacts; 2â=âgood, mild artifacts; and 3â=âpoor, extensive artifacts. Image quality scores between the VMS-only and VMS + MAR groups were compared;74 keV was found to be the optimal level for VMS images. The image quality of the VMS + MAR images at 74âkeV were significantly better than VMS-only images (1.35â±â0.59 vs 2.11â±â0.87, Pâ=â.005). There was no difference in image quality score among VMS + MAR images at 74 keV and higher energy levels.VMS images from DECT at 74 keV with MAR can reduce artifacts from microcoils and improve image quality for microcoil localization of pulmonary nodules.
Asunto(s)
Pulmón/patología , Nódulos Pulmonares Múltiples/diagnóstico por imagen , Imagen Radiográfica por Emisión de Doble Fotón/métodos , Tomografía Computarizada por Rayos X/métodos , Algoritmos , Artefactos , Humanos , Pulmón/diagnóstico por imagen , Metales , Estudios Prospectivos , Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodosRESUMEN
Usually, coronary computed tomography angiography (CCTA) is performed during breath-holding to reduce artifact caused by respiration. The objective of this study was to evaluate the feasibility of free-breathing CCTA compared to breath-holding using CT scanner with wide detector. To evaluate the feasibility of CCTA during free-breathing using a 256-MDCT. In 80 patients who underwent CCTA, 40 were performed during breath-holding (group A), and the remaining 40 during free-breathing (group B). The quality scores for coronary arteries were analyzed and defined as: 3 (excellent), 2 (good), and 1 (poor). The image noise, signal-to-noise ratio and effective radiation dose as well as the heart rate variation were compared. The noise, signal-to-noise ratio, and effective radiation dose were not significantly different between the 2 groups. The mean heart rate variation between planning and scanning for group A was 7â±â7.6âbpm, and larger than 3â±â2.6âbpm for group B (P = 0.012). Quality scores of the free-breathing group were better than those of the breath-holding group (group A: 2.55â±â0.64, group B: 2.85â±â0.36, P = 0.018). Free-breathing CCTA is feasible on wide detector CT scanner to provide acceptable image quality with reduced heart rate variation and better images for certain patients.