ABSTRACT
BACKGROUND: C-arm fluoroscope has been widely used to promote more effective pain management; however, unwanted radiation exposure for operators is inevitable. We prospectively investigated the differences in radiation exposure related to collimation in Medial Branch Block (MBB). METHODS: This study was a randomized controlled trial of 62 MBBs at L3, 4 and 5. After the patient was laid in the prone position on the operating table, MBB was conducted and only AP projections of the fluoroscope were used. Based on a concealed random number table, MBB was performed with (collimation group) and without (control group) collimation. The data on the patient's age, height, gender, laterality (right/left), radiation absorbed dose (RAD), exposure time, distance from the center of the field to the operator, and effective dose (ED) at the side of the table and at the operator's chest were collected. The brightness of the fluoroscopic image was evaluated with histogram in Photoshop. RESULTS: There were no significant differences in age, height, weight, male to female ratio, laterality, time, distance and brightness of fluoroscopic image. The area of the fluoroscopic image with collimation was 67% of the conventional image. The RAD (29.9 +/- 13.0, P = 0.001) and the ED at the left chest of the operators (0.53 +/- 0.71, P = 0.042) and beside the table (5.69 +/- 4.6, P = 0.025) in collimation group were lower than that of the control group (44.6 +/- 19.0, 0.97 +/- 0.92, and 9.53 +/- 8.16), resepectively. CONCLUSIONS: Collimation reduced radiation exposure and maintained the image quality. Therefore, the proper use of collimation will be beneficial to both patients and operators.
Subject(s)
Female , Humans , Male , Operating Tables , Prone Position , Prospective Studies , ThoraxABSTRACT
Objective: To set up a new measurement method for radiation absorbed dose by using chrominance technology. Methods: The changes of trichromatic values were measured using color analysis technique after different concentrations of alphaurine A aqueous solutions (500 mg/L, 250 mg/L, and 150 mg/L) were irradiated with 1.5-13.5 kGy doses of γ-rays at room temperature. Immediately after irradiation, the trichromatic color testing device was used to determine the trichromatic color changes of the samples for further statistical processing, analysis, and mapping. Repeated measurements were obtained with the test samples. The samples was stored at room temperature of summer for two weeks and the above protocol was repeated. Paired t-test was used for statistical analysis. Results: The trichromatic red-green-blue color underwent evident changes with the changes of reagent concentrations and absorbed doses. There was a gradual increment of absorption value (80-360) of the red color with the increment of absorbed dose in 500 mg/L group; meanwhile, there was a decrement of absorption value (580-250) of blue color with the increment of absorbed dose, which showed that the changing trend of the red color and blue color was on contrary. Compared with the red and blue, the absorption value of green color underwent a slighter change(270-320) with the increment of absorbed doses. Despite a similar color change trend in all the experimental groups, the solution concentration and the radiation dose were the main factor for ideal trichromatic data. The change of color in the solution of lower concentration was greater within a smaller range of absorption dose. Temperature had little influence on the measuring results after the irradiated samples were kept for two weeks at the room temperature in the summer (P>0.05). Conclusion: Ionizing radiation-induced color change combined with chrominance technique may provide a new convenient method for studying radiation absorbed dose.
ABSTRACT
0.05).Conclusion:Ionizing radiation-induced color change combined with chrominance technique may provide a new convenient method for studying radiation absorbed dose.