Background Spinal digital subtraction angiography (DSA) exposes patients and operators to substantial amounts of radiation. Antiscatter grid (ASG) removal is used to decrease radiation exposure but may reduce image quality. Purpose To determine whether ASG removal during spinal DSA in adults reduces radiation dose while maintaining diagnostic image quality and whether dose reduction is related to body mass index (BMI). Materials and Methods This Health Insurance Portability and Accountability Act-compliant prospective study included adults undergoing spinal DSA between January and December 2016. Each procedure included an additional angiographic acquisition performed twice, once with and once without ASG, either documenting the artery of Adamkiewicz (no pathology group) or the condition leading to the procedure (pathology group). Dose differences between study acquisitions and the influence of BMI were evaluated via paired t test. Two neurointerventionalists blinded to acquisition protocols were asked to independently evaluate a sample of 40 study acquisitions (20 with ASG, 20 without ASG) from 20 randomly selected participants to (a) rate image quality, (b) categorize findings, and (c) determine whether images had been obtained with or without ASG. Percentage agreement on image quality, findings categorization, and ability to correctly identify the acquisition protocol was calculated for both readers. Results Fifty-three participants (mean age ± standard deviation, 51 years ± 15.2; 32 men) were evaluated. ASG removal reduced the mean dose per acquisition by approximately 33% (mean dose-area product and air kerma decreased from 202 to 135.6 µGy/m2 and from 35.3 to 24 mGy, respectively; P < .001) independently of BMI (P = .3). Both readers evaluated all images (40 of 40) as being of diagnostic quality and correctly categorized findings in 19 of 20 (95%) cases. Overall percentage agreement for correct protocol identification was 60% (12 of 20) for grid-in and 45% (nine of 20) for grid-out images. Conclusion Antiscatter grid removal during spinal digital subtraction angiography decreased participants' radiation exposure while preserving diagnostic image quality. © RSNA, 2020.

https://pubs.rsna.org/doi/pdf/10.1148/radiol.2020191786

Removal of Antiscatter Grids for Spinal Digital Subtraction Angiography: Dose Reduction without Loss of Diagnostic Value

Aim: Radiation reduction is essential. In cardiac electrophysiology imaging without the anti-scatter grid has been proven as a means of achieving further radiation reduction. We evaluate the application of this gridless imaging technique to deliver further reductions in radiation risk to both patients and personnel during coronary angiography(C/C) and percutaneous coronary interventions (PCI). Methods and Results: We compared 6 consecutive coronary angiograms and 4 consecutive PCIs with and without the antiscatter grid in our new Toshiba Infinix-I angiography suite (Toshiba Medical Systems, Japan) in patients with a Body Mass Index (BMI) under 30. We chose this number as we felt it was a threshold BMI above which image quality may be compromised. For all cases all radiation and clinical data were recorded. All procedures were performed without complication. An appreciable difference in image quality without the grid was noted only during fluoroscopy with movement. However during still fluoroscopy and cine acquisition there was no notable difference. One possible future approach may also be selected use of the gridless technique with re-introduction of the grid in larger patients or during aspects of the procedure where image quality is important. The most marked difference in radiation reduction was seen during PCI.

M. Sader

Papers

Removing the Antiscatter Grid: A simple way to lower radiation during both Angiography and PCI