Spectral CT: preliminary studies in the liver cirrhosis.

Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Henan Province 450052, China.
Korean journal of radiology: official journal of the Korean Radiological Society (Impact Factor: 1.32). 07/2012; 13(4):434-42. DOI: 10.3348/kjr.2012.13.4.434
Source: PubMed

ABSTRACT To investigate the value of spectral CT imaging in the diagnosis and classification of liver cirrhosis during the arterial phase (AP) and portal venous phase (PVP).
Thirty-eight patients with liver cirrhosis (Child-Pugh class A/B/C: n = 10/14/14), and 43 patients with healthy livers, participated in this study. The researchers used abdominal spectral CT imaging during AP and PVP. Iodine concentration, derived from the iodine-based material-decomposition image and the iodine concentration ratio (IC(ratio)) between AP and PVP, were obtained. Statistical analyses {two-sample t test, One-factor analysis of variance, and area under the receiver operating characteristic curve (A [z])} were performed.
The mean normalized iodine concentration (NIC) (0.5 ± 0.12) during PVP in the control group was significantly higher than that in the study group (0.4 ± 0.10 on average, 0.4 ± 0.08 for Class A, 0.4 ± 0.15 for Class B, and 0.4 ± 0.06 for Class C) (All p < 0.05). Within the cirrhotic liver group, the mean NIC for Class C during the AP (0.1 ± 0.05) was significantly higher than NICs for Classes A (0.1 ± 0.06) and B (0.1 ± 0.03) (Both p < 0.05). The IC(ratio) in the study group (0.4 ± 0.15), especially for Class C (0.5 ± 0.14), was higher than that in the control group (0.3 ± 0.15) (p < 0.05).The combination of NIC and IC(ratio) showed high sensitivity and specificity for differentiating healthy liver from cirrhotic liver, especially in Class C cirrhotic liver.
Spectral CT Provides a quantitative method with which to analyze the cirrhotic liver, and shows the potential value in the classification of liver cirrhosis.

  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the image quality of dual-energy abdominal computed tomography (DECT) angiography (CTA) with a non-linear image blending technique as compared with the linear image blending technique and standard single-energy CT (SECT; 120 kVp SECT) imaging. Thirty-two patients underwent dual-source, dual-energy abdominal CTA (80 kVp/140 kVp mode) in the arterial phase to generate non-linear image blending and 0.5 linear image blending images. Abdominal vessel enhancement, image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were evaluated and compared to the conventional 120 kVp SECT image sets (n = 29) using repeated-measures analysis of variance (ANOVA) with Bonferroni adjustment. Two radiologists assessed subjective vessel enhancement in consensus. The effective dose was calculated and compared using Student's t-test. The non-linear image blending images were ranked highest (over 0.5 linear image blending and 120 kVp SECT images) regarding mean vascular attenuation, CNR, SNR, and subjective image quality evaluation (p-values ranging from <0.001-0.021). However, there was no significant difference in renal artery branch visualization among the three sets of images (p = 0.405). Linear image blending images showed improved vascular attenuation (p = 0.011) as compared with 120 kVp SECT images, but displayed similar results regarding CNRs (p = 0.045) and SNRs (p = 0.053). The effective radiation dose for the DECT protocol was much lower than the SECT protocol (p = 0.004). The non-linear image blending technique of 80 kVp/140 kVp DECT improved vascular visualization by improving contrast enhancement in abdominal CTA during the arterial phase.
    Clinical Radiology 11/2013; · 1.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVE. The purpose of this study was to evaluate the effect of use of dual-energy CT monochromatic imaging in the late hepatic arterial phase on hyperenhancing focal lesion detection and lesion conspicuity. SUBJECTS AND METHODS. This prospective study included 72 patients imaged with a single-source dual-energy CT scanner. Late arterial phase imaging was performed with dual energies of 140 and 80 kVp, and the portal venous and delayed phases were performed with a single energy of 120 kVp. Two deidentified image sets were created: set A consisted of 77-keV images only, and set B consisted of 40-, 50-, 70-, and 77-keV images and iodine-based contrast material decomposition images. Two independent reviewers identified hypervascular lesions and subjectively scored lesion conspicuity. Contrast-to-noise ratios were calculated, and radiation dose (volume CT dose index) was recorded. RESULTS. The 128 lesions identified had a mean size of 1.7 ± 1.4 cm. There was no difference in lesion detection between the two reviewers or the two image sets. The contrast-to-noise ratio at 50 keV was 72% greater than that at 77 keV (p < 0.0001). Subjective conspicuity was statistically greatest at 50 keV (p < 0.0001). There was no statistical difference in mean volume CT dose index between the dual-energy (12.8 mGy) and the two single-energy (14.4 and 14.2 mGy) phases. CONCLUSION. Viewing dual-energy CT images may result in the greatest subjective lesion conspicuity and measured contrast-to-noise ratio at 50 keV with equal detection of hyperenhancing liver lesions compared with viewing 77-keV images alone. In addition, the radiation doses of dual-energy CT may be similar to those of single-energy CT.
    American Journal of Roentgenology 09/2014; 203(3):601-6. · 2.74 Impact Factor


Available from