Removal of the antiscatter grid during routine biliary interventional procedures performed in a flat-panel...

To determine whether grid removal during routine biliary interventional procedures performed in a flat-panel interventional suite results in adequate image quality and a significant decrease of patient radiation exposure.

Routine biliary interventional procedures were defined as those in which absence of fine image detail during fluoroscopy carries no procedural impact, including substitution of internal-external biliary drains (n = 25) or bilioplasty of benign biliary anastomotic strictures (n = 5). All patients had undergone a previous procedure in which the grid was used. Constant object-to-detector and source-to-image distance were maintained in each patient during the grid/no-grid procedures. The same fluoroscopy protocol was used for all examinations. The dose area product (DAP [cGy.cm(2)]) and procedure fluoroscopy time (seconds) were recorded for each procedure. DAP was normalized per unit of fluoroscopy time (nDAP [cGy.cm(2)/s]).

In all procedures, image quality was considered adequate by two different interventional radiologists, and all procedures were successfully completed without significant changes in fluoroscopy time between the two groups (p = 0.13). In every procedure without the grid, nDAP was inferior compared with nDAP in procedures performed using the grid. The mean decrease in dose was 39.2 ± 23.5 % (p = 0.000001).

Our preliminary data show that removal of the grid during routine biliary procedures is feasible and results in a significant decrease of patient radiation exposure. This seems of particular relevance because most of these patients require frequent reintervention. Larger studies with more procedures are warranted to confirm these data.