| Part IApplication of dual energy scan technique with selective photon shield in CTA diagnosis of intracranial aneurysmsObjectiveTo investigate the clinical value of dual energy scan technique with selective photon shield (SPS) in application of dual energy Computed tomography angiography diagnosis of intracranial aneurysms.Materials and MethodsSeventy cases with clinically suspected intracranial aneurysms were examined with CT angiography and then were examined with3D-DSA one week later. in particular, the dual energy SPS was used for CT scanning, tube voltages are respectively80kV and sn140kV, the quality reference milliampere (mAs) was set up as300mAs and150mAs. Subsequently,the image quality of SPS-DECTA subjective ratings and we compared and analyzed the two diagnostic methods as regard to aneurysm location, aneurysm numbers, morphology, aneurysmal neck display degree, aneurysmal neck size, and long or short diameter.ResultsThe image quality of SPS-DECTA were all above4scores, which could satisfy the diagnostic demands. The3D-DSA was referred to as the diagnostic standard and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of SPS-DECTA detecting aneurysms that are all100%.These are63aneurysm was examined with SPS-DECTA, in which the mean long diameter, mean short diameter and aneurysmal neck being4.89±1.52mm,3.89±1.56mm,3.02±0.75mm, respectively. These are63aneurysms were also examined with3D-DSA, in which the mean long diameter, mean short diameter and aneurysmal neck were4.96±1.47mm,4.01±1.59mm, and2.91±0.73mm, respectively. The3D-DSA was referred to as the diagnostic standard. There was no significant difference between two diagnostic methods regarding aneurysm location, number, and measurement of the aneurysms (P>0.05), and there were a good correlation between both two methods (r=0.963,0.968,0.856; P=0.000).ConclusionThe SPS-DECTA possesses a high accuracy in diagnosis of intracranial aneurysms and can be used as a routine non-invasive screening method. Part ⅡDual energy scan technique with selective photon shield in CTA diagnosis of intracranial aneurysms image quality evaluationObjectiveTo investigate image quality evaluation of dual energy scan technique with selective photon shield (SPS) in application of dual energy CTA diagnosis of intracranial aneurysms.Materials and Methods80cases with clinically suspected intracranial aneurysms were examined with CT angiography, and equally divided into two groups:selective photon shield dual energy CTA (SPS-DECTA) and dual energy CTA (DECTA), CTDIvoi of two groups was set to20.0before scanning, scan protocol of SPS-DECTA (the same with the first part):tube voltages are respectively80kV, sn140kV, tube currents are300mAs,150mAs, respectively; tube voltages of DECTA group are140mV and80kV, tube currents are50mAs and213mAs. The rest protocol are the same. The3D-DSA and the surgery verification are the gold criteria. Subjective score and objective scores of the two groups were measured and compared, aneurysm location, aneurysm numbers,morphology, aneurysmal neck display degree, aneurysmal neck size and long or short diameter of the two groups were compared and studied.ResultsThe CT value of OL, ACA, MCA, and PCA of the SPS-DECTA were (32.32±3.29),(126.78±23.27),(150.73±39.09),(84.47±9.63), the noise were (5.34±1.22),(39.94±15.96),(49.26±18.93),(22.17±5.51), CT value of DECTA group were (31.05±5.13)、(124.96±19.92)、(156.50±29.37)、(86.83±14.16), the noise were (5.28±1.66)、(40.94±12.38)、(54.79±14.65)、(26.74±8.45), the difference was not statistics significant (p>0.05). SNR of SPS-DECTA was (7.37±1.56),(4.48±0.92),(5.32±0.91),(5.02±0.99),the CNR was (21.59±6.46),(25.26±9.41),(13.28±3.25); SNR of DECTA was (5.21±1.35),(2.99±1.00),(3.95±0.53),(3.42±0.71), the CNR was (16.43±7.29)、(21.29±7.40)、(10.53±4.62), the difference was not statistics significant (p>0.05). Differences between the two groups of intracranial vascular subjective scoring were not statistically significant (p>0.05) and differences between the group of petrosal and syphon segment of skull base vascular subjective scoring were statistically significant (p<0.05).30out of40cases in SPS-DECTA group detect as aneurysm without misdiagnosis and missed diagnosis. The mean long and short diameter and neck size of aneurysm detected by3D-DSA were (5.78±3.34) mm;(4.62±3.25) mm;(3.19±1.47)mm; aneurysm location, aneurysm numbers and measurements of the two methods were close related without significant statistical differences (R values were0.953、0.982、0.974, P=0.000).26out of40cases in DECTA group detected as aneurysm with misuse of1cases, the detection rate was96%(27/28). The mean long and short diameter and neck size of aneurysm were (5.76±3.19) mm;(4.59±3.27) mm. Mean long and short diameter and neck size by3D-DSA were(5.82±3.27)mm;(4.67±3.31)mm;(3.29±1.38)mm. Aneurysm locations, numbers and neck size by the two methods were closed related without significant differences in statistic (R values were0.964、0.968、0.856, P=0.000)ConclusionThe SPS-DE possesses high accuracy in diagnosis of intracranial aneurysms via CTA technology, and could be used as a routine non-invasive screening methods. Part ⅢImage quality evaluation of selective photon shield combined with SAFIRE in application of dual-energy CTA diagnosis of intracranial aneurysms.ObjectiveTo investigate image quality evaluation of SPS combined with SAFIRE in application of dual energy CTA diagnosis of intracranial aneurysms.Materials and MethodsSome80patients suspected with intracranial aneurysms were underwent CT angiography randomly divided into two groups. The tube voltages of two groups are like. Experimental group(SPS with SAFIRE):the tube voltages were respectively80kV, sn140kV, tube currents were200mAs,100mAs, SAFIRE (value=3) reconstruction; control group(SPS only): It is same as the SPS group of the second part, tube voltages were80kV and sn140kV, tube currents were300mAs and150mAs. The rest protocol was the same. Subjective score, objective scores and Radiation dosage of the two groups were measured and compared, aneurysm location, aneurysm numbers, morphology, aneurysmal neck display degree, aneurysmal neck size and long or short diameter of the two groups were compared and studied.ResultsMean CT value was not statistically different in two groups (P>0.05). The noise was statistically significant in two groups (all P<0.05). SNR of two groups were statistically significant in two groups (P>0.05). The CNR was not statistics different in two groups (p>0.05). Intracranial vascular objective scoring of two groups were not statistically different (p>0.05). CTDIvol was (13.59±1.27) mGy in experimental group, while (20.61±1.07) mGy in control group. DLP was (259.41±27.48) mGy·cm in experiental group, while (378.37±19.25) mGycm was in control group. ED was (0.54±0.06) mSv in experimental group, while (0.79±0.04)mSv in control group (all P<0.05).CTDIvol, DLP and ED of the experimental group that were reduced about7.02mGy,118.96mGy.cm and0.25mSv respectively, about 34.06%,31.44%,31.65%.29out of40cases in experimental group detected as aneurysm without misdiagnosis or missed diagnosis. The mean long and short diameter and neck size of aneurysm were (5.86±3.19) mm;(4.64±3.14) mm;(3.21±1.17) mm. Mean long and short diameter and neck size by3D-DSA were(5.79±3.37)mm;(4.58±3.15)mm;(3.18±1.46)mm; Aneurysm locations, numbers and neck size by the two methods were closed related without significant differences in statistic (Rvalues were0.964、0.968、0.856, P=0.000).25out of40cases in control group detected as aneurysm with misuse of2cases, the detection rate was96%(25/26). The mean long and short diameter and neck size of aneurysm were (5.73±3.21) mm;(4.59±3.27) mm;(3.34±1.17)mm. Mean long and short diameter and neck size by3D-DSA were (5.71±3.26) mm;(4.71±3.28) mm;(3.26±1.37)mm. Aneurysm locations, numbers and neck size by the two methods were closed related without significant differences in statistic (R values were0.964.0.968、0.856, P=0.000)ConclusionSPS combined with SAFIRE in application of dual energy CTA diagnosis of intracranial aneurysms could reduce the radiation dosage, improve CT Image quality and high accuracy diagnosis synchronously which has a potential clinical value as a routine screening method. |
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