Influence of the antiscatter grid on dose and image quality in pediatric interventional cardiology X‐ray systems

Abstract

Objective: To present a methodology and experimental results to assess the influence, in terms of dose and image quality, of the antiscatter grid (AG) in a pediatric cardiology X-ray system. Method: Entrance surface air kerma and image quality, using a test object and different added thicknesses of polymethyl methacrylate (PMMA), for three different acquisition protocols, were measured with and without the AG, for fluoroscopy and cine modes. The image quality parameters, signal-to-noise ratio (SNR), highcontrast spatial resolution (HCSR) and two figures of merit (FOM) were evaluated. Results: The average bucky factor values measured during this experiment were 1.99, 2.49, 2.85, and 3.30, respectively for 4, 8, 12, and 16 cm of PMMA. SNR variations do not appear to be relevant when removing the AG. However, the use of AG improves HCSR significantly. Imaging the test object with 4 cm of PMMA seems appropriate without the AG, but for 8 cm (equivalent to chest thicknesses of 12 cm) and greater thicknesses, a good image quality would require the use of AG. Conclusions: The AG should not be used for neonates and very young children with chest thicknesses equal to or less than 6 cm and weight less that 6 kg.V C 2013 Wiley Periodicals, Inc.

Measures to Reduce Radiation in a Modern Cardiac Catheterization Laboratory

“…One of these radiation reduction measures includes the low-dose acquisition technology that reduces the amount of x-ray delivered per frame, without any appreciable loss of diagnostic quality. 15,16 Despite a conspicuous paucity of studies describing the image quality on use of low-dose acquisition modalities in a cardiac catheterization laboratory, ample data from the computed tomographic literature have indicated that there is little to no loss of image quality with the use of Background-X-ray use in the catheterization laboratory is guided by the principle of as low as reasonably achievable. In accordance with this principle, we reduced the default fluoroscopic frame rate from 10 to 7.5 frames/s and increased the emphasis on the use of low-dose acquisition starting January 1, 2013.…”

Comparison of pediatric radiation dose and vessel visibility on angiographic systems using piglets as a surrogate: antiscatter grid removal vs. lower detector air kerma settings with a grid — a preclinical investigation

“…Conventionally, pediatric imaging has been viewed as an opportunity to reduce patient dose by removing the antiscatter grid. The reduction of pediatric patient dose has been quantified numerous times, 7 , 13 , 16 , 17 , 18 , 19 but the loss of image quality, due to the increase in scatter (increased scatter/primary) when evaluated, was quantified with phantoms as opposed to live animal models 7 , 9 , 14 , 16 , 17 , 20 . This manuscript suggests the alternative of leaving the grid in place to preserve contrast, but lowering detector ${\mathrm{K}}_{\text{air}}$ setting to reduce piglet ${\mathrm{K}}_{\text{air}}/\text{fr}$ which reduces the piglet's dose.…”

“…Three different studies performed with phantoms simulating patients 17 , 19 , 20 were performed in interventional cardiology labs; the authors of those studies recommended the removal of the grid for small patients. Ubeda et al (20) evaluated the difference in dose and image quality with and without the grid in place for four simulated patient thicknesses of 8, 12, 18, and 24 cm. They suggested that, for a patient thickness of 8 cm, the grid could potentially be removed without noticeable loss of image quality, but it should remain in place for patient thicknesses of 12 cm and above.…”

“…To this end, numerous authors over a number of years have recommended removing the antiscatter grid from the X‐ray beam during fluoroscopic examinations of small children 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 . While some authors have quantified the reduction in patient dose to these pediatric patients, 7 , 13 , 16 , 17 , 18 , 19 the loss of image quality associated with this reduction in patient dose has been measured only on a limited basis 7 , 9 , 14 , 16 , 17 , 20 with phantoms as opposed to live models. In addition, the studies that do exist 7 , 20 , 21 tend to address the pediatric interventional cardiology laboratory application as opposed to the pediatric interventional radiology laboratory.…”

Removal of the Antiscatter Grid During Routine Biliary Interventional Procedures Performed in a Flat-Panel Interventional Suite: Preliminary Data on Image Quality and Patient Radiation Exposure

“…Research performed on film-screen systems in the 1980s showed that grid removal in pediatric patients undergoing fluoroscopy results in a dose reduction of up to one-third to one half with little or no compromise of the CNR [5]. The role of grid-removal on patient radiation protection has also been recently investigated in fullfield mammography [6] and interventional pediatric cardiology [7,8].…”