| Objectives:the optimal single image energy of energy spectrum CT and conventional CT on the subjective and objective evaluation to the lesions cured by iodine oil sclerosis after TACE; energy spectrum CT and conventional CT in the diagnosis of residual or recurrent disease after transcatheter arterial chemoembolization(TACE) are compared to analyze their value.Methods: 31 cases of primary liver cancer after clinical diagnosis and a total of53 t lesions are analyzed and sorted. They have respectively received one or more TACE operation, and are conducted with gem spectrum CT liver dual phase enhanced scanning in 1-3 months, with an interval of 3-5 days to do digital subtraction angiography(DSA) examination. After gem energy spectrum CT scanning, the hybrid energy image(QC) and energy spectrum image with energy spectrum information are obtained. In this study, the hybrid energy images in place of the conventional CT images are compared for analysis.1. The contrast noise ratio(CNR) curve function of energy spectrum post-processing software is used to obtain the optimal single energy value corresponding to TACE postoperative lesions and normal liver tissue maximum CNR. Through the subjective visual grading and calculation the contrast noise ratio(CNR) is compared with the optimal single imageof hybrid energy QC image so as to display iodine oil deposition and CNR value. The statistical method use paired t-test, when P<0.05, it is thought that the difference is statistically significant.2. The residual or recurrence of the lesions after TACE operation is determined by liver dual phase enhanced scanning.DSA angiography results are taken as the gold standard to calculate the diagnostic sensitivity, specificity, positive predictive value and negative predictive value of conventional CT and energy spectrum CT(the optimal single energy image, iodine- graph, spectral curve).The statistical method use ?~2-test, when P<0.05, it is thought that the difference is statistically significant.Results:1.It is found after observing the CNR curve of multiple lesions and liver tissue that was the optimal single energy of lesions is mostly between 62-68 ke V energy level, the average value of optimal single energy is(64.92 + 3.12) ke V.The image smaller than optimal single energy level has a larger artifact with clear contrast of the image edge and larger lesions contrast; the image larger than the optimal single energy level has a reduced artifacts with a narrow iodine oil range and the smaller iodine oil depositis filtered, so that the edge becomes short-tempered, lesions contrastis small.2. the subjective ratingif hybrid energy image QC and optimal single energy image is respectively(0.94±0.48)and(1.33±0.55). The CNR valueof QC image is plain scan(1.52±1.48), arterial phase(3.47±1.79),portal vein phase(2.4±1.62); The CNR value of optimal single energy image is plain scan(1.69±1.08), arterial phase(4.33±1.8), portal vein phase(3±1.78).Compared with the QC image, the best single energy image has a higher subjective score,a larger image contrast noise ratio(CNR), and the subjective score ?arterial-phase CNR and portal-phase CNR difference are statistically significant(P < 0.05).3. DSA angiography results are taken as the gold standard to compare conventional QC hybrid energy image with hepatocellular carcinoma after TACE operation. The diagnosis sensitivity is 60.00%, the specificity is 86.96%,Accuracy is 71.70%, the positive predictive value is 85.71%, and the negative predictive value is 62.50%.The energy spectrum CT(best single energy spectrum, iodine base figure and energy spectral curves) of the diagnosis sensitivity is 90.00%, the specificity is 91.30%, Accuracy is 94.34%, positive predictive value is 90.56%, and negative predictive value is 87.50%. The energy spectral CT were higher than those of conventional CT, P<0.05, and the difference was statistically significant.Conclusions:1. the average value of optimal single energy corresponding to TACE postoperative lesions and normal liver tissue maximum CNR is(64.92 + 3.12)ke V.2.Compared with the QC image, the best single energy image of energy spectrum has a clear deposition of iodine oil; the contrast of the lesion is higher,which can effectively reduce iodine oil hardening artifacts.3. Compared with the conventional CT, the energy spectrum CT can clearly show the lesion enhancement of the liver after TACE operation, so that we can analyze the nature of the lesion, which has a greater clinical value for evaluating the curative effect after TACE operation. |
PDF Full Text Request