Résumé
Objective@#To explore the clinical value of 3D-DSA technology in the diagnosis and treatment guidance of hepatic artery chemoembolization.@*Methods@#Liver cancer patients in the treatment groups were collected to receive 3D-DSA imaging guidance at the Affiliated Hospital of Xuzhou Medical University between March and May 2017. In addition, routine 2D-DSA imaging was selected for treatment-received group. Intra-operative blood vessels and tumor-like lesions were observed. The total exposure dose (CAK, unit mGy), cumulative irradiation intensity per unit area (DAP, unit mGy.cm2) and dosage of contrast agent (ml) were calculated separately for two groups of patients. The same senior physicians and technicians operated both groups of patients. Comparisons of measurement were analyzed by t-test and chi-square test was used for count data.@*Results@#Data of twenty patients were collected from the two groups. Tumor location, target vessels structure and shape of development were clear in all patients in the treatment group. The control group had 17 cases of tumor development and the target vascular structure was clear in 16 cases. CAK mean treatment group was lower than control group (554.11 + 38.87) mGy and (644.53 + 26.70) mGy, and DAP mean treatment group was lower than the control group (125.25 + 7.54) mGy·cm2 and (143.49 + 6.18) mGy·cm2. The two groups were compared (P value < 0.05), and the differences were statistically significant. The mean dose of contrast agent in the two groups were lower than control group (64.42 + 3.92) ml, (70.79 + 4.47) ml, and the differences between the two groups were statistically significant (P < 0.05).@*Conclusion@#3D-DSA imaging technology can provide effective diagnosis and guidance in the treatment of hepatic artery chemoembolization. It can effectively reduce the radiation exposure dose and radiation intensity, and it is of high clinical value for interventional embolization of liver cancer.
Résumé
Objective To evaluate the effect of different tube voltages on the radiation dose and image quality of a full field digital mammography system.Methods Both experiments were performed under manual exposure mode.In one experiment,the tube voltages were kept constant at 25,28 and 31 kVp,and the CIRS 015 phantom was exposed at three target/filter combinations molybdenum/molybdenum (Mo/Mo),molybdenum/rhodium (Mo/Rh),and rhodium/rhodium (Rh/Rh) and at tube current-exposure time products of 32-140mAs.The entrance skin exposure (ESE) and average glandular dose (AGD) were recorded,the signal-to-noise ratio(SNR) and contrast-to-noise ratio (CNR) and figure of merit (FOM) were measured to evaluate the influences of different tube voltages on dose and image quality at same target/filter combination.The univariate of randomized completed block-design was used for statistics.In second experiment,the phantom were exposed using Mo/Rh combination when the tube current-exposure time product was kept constant at 56 mAs,and the tube voltage varied between 23 and 33 kVp in 1-kVp increments.The ESE and AGD were recorded,the SNR,CNR and FOM were measured for plotting the curves against tube voltages.Results At Mo/Mo combination,the AGD,ESE,SNR,CNR and FOM of 25,28 and31 kVp were(1.25 ±0.56) mGy,(6.46±2.86) mGy,71.52±8.37,1.91 ±0.26,3.21 ± 0.68; (1.94 ±0.85) mGy,(9.18±4.07) mGy,144.46 ± 11.31,2.41 ±0.28,3.37 ±0.96 and (3.01 ±1.38) mGy,(12.60±5.59) mGy,128.89 ±15.29,2.47 ±0.31,2.31 ±0.76 respectively; at Mo/Rh combination were (1.23 ±0.55) mGy,(5.26 ±2.33) mGy,67.31 ±4.11,1.82 ±0.19,3.01 ± 0.82; (1.86 ±0.84) mGy,(7.57 ±3.34) mGy,139.54 ± 12.16,2.30 ±0.25,3.23 ±0.92 and (2.81 ±1.24) mGy,(10.48 ±4.62) mGy,127.77 ±15.14,2.59 ±0.31,2.67 ±0.68; and at Rh/Rh were(1.09 ±0.48) mGy,(4.89 ±2.16) mGy,67.46 ±2.23,1.48 ±0.72,3.08 ± 1.69; (1.75 ± 0.78) mGy,(6.88 ±3.03) mGy,137.74 ± 14.65,2.37 ±0.26,3.62 ± 1.07 and (2.59 ± 1.13) mGy,(9.32 ± 4.12) mGy,117.91 ± 19.05,2.51 ± 0.31,2.74 ± 0.84.Both experiments indicated that,for a given target/filter combination,the AGD,ESE and CNR increased,but the ESE/AGD decreased with the tube voltage increasing; The first experiment indicated both SNR and FOM of 28 kVp were higher than that of 25 kVp and 31 kVp; the second experiment showed both SNR and FOM decreased with tube voltages increasing.The differences of AGD、ESE、ESE/AGD、SNR、CNR and FOM among the three tube voltages were significant (F =4.391-528.848,P ＜ 0.05) ; but the difference of CNR between 28 and 31 kVp at Mo/Mo and Rh/Rh had no statistical significance (P ＞ 0.05) ; and the differences of FOM between 25 and 28 kVp at the three target/filter combinations were not statistically significant (P ＞ 0.05).Conclusion For a breast with 4.2 cm thickness and 50％ adipose 50％ glandular composition,different tube voltages have significant effects on the radiation dose and image quality.