ABSTRACT
Objective To investigate the effect of different additional filtration thickness of DSA on image quality and radiation dose with cerebral angiography. Methods Prospective collected 90 patients with DSA examination of the whole cerebral artery, patients were divided into A, B and C group according to the time of the examination, each group included 30 cases. Patients underwent conventional DSA, the additional filtration of group A, B and C were (1.0 mmAl+0.1 mmCu), (1.0 mmAl+0.4 mmCu) and (1.0 mmAl+0.9 mmCu), respectively. Dose area product (DAP), air kerma (AK), tube current and tube voltage of anteroposterior and lateral radiography of the whole brain were recorded, and scored the image quality. Eye lens organ dose values were obtained by using simulation phantom and LiF dosemeter under A, B and C groups with three different additional filtrations for cerebral angiography. The image quality scores and the radiation dosewere analyzed by one-way ANOVA tests or Kruskal-Wallis tests. Results The image quality comprehensive score of three groups showed significant difference (F=40.07,P<0. 01), which were (3.8±0.4), (3.6 ± 0.5) and (3.0 ± 0.6), respectively. The DAP and AK value of anteroposterior and lateral radiography of three groups also showed significant difference (P<0.05), B and C group were lower than the A group. Left and right eye lens organ dose were decreased along with the increase of the additional filtration thickness, and the difference between the 3 groups also had significant difference (P<0.01). Conclusion Both the image quality and radiation dose can acquire when conducted the whole brain DSA with 1.0 mmAl+0.4 mmCu additional filtration.
ABSTRACT
Objective To investigate the lens and pituitary dose impacted by additional filtration and collection field in head and neck DSA examinations. Methods All images were acquired by a Philips ALLura Xper FD 20 DSA machine. The combination of the different collection fields (48 cm, 42 cm, 31 cm, 22 cm) and additional filtrations (0.9 mmCu+1.0 mmAl, 0.4 mmCu+1.0 mmAl, 0.1 mmCu+1.0 mmAl) were adjusted when the anthropomorphic phantom filled with dosimeter was scanned in anterioposterior and lateral positions with 2D?DSA and 3D?DSA. The dose area product (DAP), air kerma (AK) and the radiation dose values of bilateral lens and pituitary were measured and recorded. The 2D and 3D?DSA regional absorption dose on lens and pituitary were analyzed using t' test, the correlations between DAP and AK parameters and different regional absorption doses were evaluated by Pearson rank correlation coefficient. Results Absorption doses of left lens, right lens and pituitary with 2D?DSA (n=12) were as following:(2.77 ± 0.68), (6.23 ± 3.54), (8.65 ± 2.62) mGy, while the parameters with 3D?DSA (n=12) were (1.78 ± 0.82), (2.18±1.15), (3.32±0.64) mGy, respectively;the results revealed a significant difference (t'=3.20, 3.76 and 6.85, P<0.01). DAP [(8 739±5 731) mGy·cm2] had a relationship with absorption dose of pituitary, left lens and right lens [(5.988 ± 3.299),( 2.258 ± 0.872),( 4.207 ± 3.303) mGy, r values were 0.766, 0.684, 0.727; P<0.01]. AK values was (31 ± 23) mGy and it had a relationship with pituitary absorption dose (r value was 0.894, P<0.01). The lens dose was reduced when the additional filtration was increased and the collection field was decreased, the radiation dose of the pituitary was reduced when both the additional filtration and the collection field were increased. Conclusions In the head and neck DSA examinations, the radiation dose of the lens and the pituitary had different changes with the different additional filters and collecting fields. The organ dose with 3D?DSA was significantly less than that with 2D?DSA.