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Computed tomography (CT) is often performed as the initial imaging study for the workup of patients with known or suspected liver disease. Our article reviews liver CT techniques and protocols in clinical practice along with updates on relevant CT advances, including wide-detector CT, radiation dose optimization, and multienergy scanning, that have already shown clinical impact. Particular emphasis is placed on optimizing the late arterial phase of enhancement, which is critical to evaluation of hepatocellular carcinoma. We also discuss emerging techniques that may soon influence clinical care.
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Carcinoma, Hepatocellular , Liver Neoplasms , Carcinoma, Hepatocellular/diagnostic imaging , Contrast Media , Humans , Liver Neoplasms/diagnostic imaging , Magnetic Resonance Imaging , Tomography, X-Ray ComputedABSTRACT
Objective To investigate the application value of multiple?arterial?phase imaging technique with differential sub?sampling with cartesian ordering (DISCO) in the gadoxetate acid disodium enhanced liver MRI. Methods From September 2017 to March 2018, 56 patients with suspected malignant focal liver disease diagnosed with ultrasound or CT in West China Hospital of Sichuan University were enrolled prospectively, and underwent preoperative enhanced MRI with gadoxetate acid disodium. Patients were divided into 2 groups by random?number table method. Twenty nine patients in group A underwent liver multiple?arterial?phase imaging with DISCO. Twenty seven patients in group B underwent single?arterial?phase imaging with liver acquisition with volume acceleration?flex (LAVA?Flex). The display rate of late?arterial?phase and respiratory motion artifacts of dynamic enhancement images were evaluated. The categorical variables was compared by Chi?square test. The respiratory motion artifacts between the single?arterial?phase and multiple?arterial?phases were compared by Mann?Whitney U test. The artifact scores among the various phases of the multi?arterial phase were compared by Kruskal?Wallis H. Results Compared to LAVA?Flex [74.1%(20/27)], a higher display rate of late?arterial phase [96.6%(28/29)] was found in DISCO (Group A), and the difference was statistically significant (χ2=5.770, P=0.016). In the evaluation of respiratory motion artifacts, the motion artifacts of the late?arterial images obtained by LAVA?Flex [3(3,4)] were more severe than the DISCO [2(2,3)], and the difference was statistically significant (Z=-3.250, P<0.01). Among the scores of motion artifacts in the 6 phases of DISCO, the artifact scores of phase 1, 2, 3, 4, 5, 6 were [3(3,4)], [2(2,3)], [2(2,3)], [3(2,3)], [3(3,4)] and [3(3,4)], respectively. The motion artifacts of phase 2, 3, 4 were better than phase 1, 5, 6, the differences were statistically significant (P<0.05), but there was no statistical differences among phase 2, 3 and 4 (P>0.05). Conclusion Compared with single?arterial?phase imaging, multiple?arterial?phases with DISCO using gadoxetate acid disodium can improve the capture rate of late arterial phase and reduce motion artifacts.
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Objective@#To investigate the application value of multiple-arterial-phase imaging technique with differential sub-sampling with cartesian ordering (DISCO) in the gadoxetate acid disodium enhanced liver MRI.@*Methods@#From September 2017 to March 2018, 56 patients with suspected malignant focal liver disease diagnosed with ultrasound or CT in West China Hospital of Sichuan University were enrolled prospectively, and underwent preoperative enhanced MRI with gadoxetate acid disodium. Patients were divided into 2 groups by random-number table method. Twenty nine patients in group A underwent liver multiple-arterial-phase imaging with DISCO. Twenty seven patients in group B underwent single-arterial-phase imaging with liver acquisition with volume acceleration-flex (LAVA-Flex). The display rate of late-arterial-phase and respiratory motion artifacts of dynamic enhancement images were evaluated. The categorical variables was compared by Chi-square test. The respiratory motion artifacts between the single-arterial-phase and multiple-arterial-phases were compared by Mann-Whitney U test. The artifact scores among the various phases of the multi-arterial phase were compared by Kruskal-Wallis H.@*Results@#Compared to LAVA-Flex [74.1%(20/27)], a higher display rate of late-arterial phase [96.6%(28/29)] was found in DISCO (Group A), and the difference was statistically significant (χ2=5.770, P=0.016). In the evaluation of respiratory motion artifacts, the motion artifacts of the late-arterial images obtained by LAVA-Flex [3(3,4)] were more severe than the DISCO [2(2,3)], and the difference was statistically significant (Z=-3.250, P<0.01). Among the scores of motion artifacts in the 6 phases of DISCO, the artifact scores of phase 1, 2, 3, 4, 5, 6 were [3(3,4)], [2(2,3)], [2(2,3)], [3(2,3)], [3(3,4)] and [3(3,4)], respectively. The motion artifacts of phase 2, 3, 4 were better than phase 1, 5, 6, the differences were statistically significant (P<0.05), but there was no statistical differences among phase 2, 3 and 4 (P>0.05).@*Conclusion@#Compared with single-arterial-phase imaging, multiple-arterial-phases with DISCO using gadoxetate acid disodium can improve the capture rate of late arterial phase and reduce motion artifacts.
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PURPOSE: To evaluate the visualization of the right adrenal vein (RAV) on dynamic contrast-enhanced computed tomography (CT) images in patients with primary aldosteronism. MATERIALS AND METHODS: We evaluated 27 consecutive patients with primary aldosteronism who underwent contrast-enhanced dynamic CT and subsequent adrenal venous sampling. Scan delays were 10-, 20- and 60-s after a bolus-tracking program detected that the threshold of a 100 Hounsfield units (HU) increase in the abdominal aorta had been achieved. RAV visualization for each phase was evaluated by two readers using a four-point scale. The Friedman and McNemar tests were employed to compare the confidence ratings and the RAV visualization rates between the three phase images. RESULTS: The RAV visualization rates were 20.4%, 83.3%, and 63.0%, for the first, second, and third phase, respectively. The RAV visualization rates were 92.6%, 83.3%, 63.0%, and 92.6% for all three phases combined, the first and second phase image combined, the first and third phase image combined, and second and third phase image combined. The combined second and third phase images had the highest RAV visualization rates compared with all other image combinations (P<0.0001). CONCLUSION: RAV visualization was significantly improved by combining the second and third phase images.
