Evaluation of patient dose and image quality in barium enema with fluoroscopic imaging systems

The purpose of this study is to evaluate the patient dose and image quality with optimum number of fluoroscopic images in lower gastrointestinal tract (double contrast barium enema) imaging.The parameters that affect both patient dose and image quality were determined and fixed on fluoroscopic imaging device. Dose measurements were made with and without filtration in lower gastrointestinal tract imaging according to these parameters. Entrance surface dose was measured 82, 5 mGy with filtration and 128, 5 mGy without filtration. The mean fluoroscopy time was recorded as 5, 3 minutes. The organ doses within the imaging volume were assessed using the PCXMC 1.5.1 software. The organ doses during imaging with and without filtration were 4,94 mGy and 5.03mGy for small intestine, 4,83 mGy and 4,87 mGy for upper large intestine, 8,75mGy and 9,10 mGy for lower large intestine, 11,03mGy and 11,10 mGy for ovaries, 10,15mGy and 11,67 mGy for testicles, 13,81mGy and 14,49 mGy for urinary bladder, 7,39 mGy and 9,51 mGy for uterus, respectively.For evaluating imaging quality with fixed parameters phantom imaging was performed using 90, 100 and 110 kVp. SNR and FOM values were calculated using the density and standard deviation measurements from phantom images that were in DICOM format. The SNR and FOM values ROI 1 and ROI 2 were 27 /1934, 38 / 3830 with 90 kVp, 29 / 1732 , 33 / 2243 with 100 kVp and 26 / 1233 , 29 / 1534 with 110 kVp, respectively.As a result, while measured total entrance surface dose without filtration was 128, 9 mGy, it was 82, 5 mGy with filtration. It was showed that using filtration significantly reduced patient total entrance surface dose (p < 0.05). However values of the organ doses were similar (p > 0.05). In addition, calculated SNR and FOM values using filtration for a given radiation dose showed better imaging quality.