Korean J Radiol.  2014 Aug;15(4):430-438. 10.3348/kjr.2014.15.4.430.

Effects of Dual-Energy CT with Non-Linear Blending on Abdominal CT Angiography

• Li S
• Wang C
• Jiang X
• Xu G

• KMID: 1731045
• DOI: http://doi.org/10.3348/kjr.2014.15.4.430

Abstract

OBJECTIVE
To determine whether non-linear blending technique for arterial-phase dual-energy abdominal CT angiography (CTA) could improve image quality compared to the linear blending technique and conventional 120 kVp imaging.
MATERIALS AND METHODS
This study included 118 patients who had accepted dual-energy abdominal CTA in the arterial phase. They were assigned to Sn140/80 kVp protocol (protocol A, n = 40) if body mass index (BMI) < 25 or Sn140/100 kVp protocol (protocol B, n = 41) if BMI > or = 25. Non-linear blending images and linear blending images with a weighting factor of 0.5 in each protocol were generated and compared with the conventional 120 kVp images (protocol C, n = 37). The abdominal vascular enhancements, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and radiation dose were assessed. Statistical analysis was performed using one-way analysis of variance test, independent t test, Mann-Whitney U test, and Kruskal-Wallis test.
RESULTS
Mean vascular attenuation, CNR, SNR and subjective image quality score for the non-linear blending images in each protocol were all higher compared to the corresponding linear blending images and 120 kVp images (p values ranging from < 0.001 to 0.007) except for when compared to non-linear blending images for protocol B and 120 kVp images in CNR and SNR. No significant differences were found in image noise among the three kinds of images and the same kind of images in different protocols, but the lowest radiation dose was shown in protocol A.
CONCLUSION
Non-linear blending technique of dual-energy CT can improve the image quality of arterial-phase abdominal CTA, especially with the Sn140/80 kVp scanning.

Keyword

Non-linear blending; Linear blending; Dual-energy CT; Abdominal CT angiography

MeSH Terms

Adult
Aged
Angiography/*methods
Body Mass Index
Female
Humans
Male
Middle Aged
Observer Variation
Radiation Dosage
Radiographic Image Enhancement/methods
Radiographic Image Interpretation, Computer-Assisted/*methods
Radiography, Abdominal/*methods
Signal-To-Noise Ratio
Statistics, Nonparametric
Tomography, X-Ray Computed/*methods

Figure

• 

  Fig. 1 Blending images and 120 kVp images. Better vascular visualization at non-linear blending images in protocol A (A) and protocol B (C) were showed compared to corresponding linear blending images [protocol A (B) and protocol B (D)] and 120 kVp images (E) (Protocol A, 80 kVp/Sn140 kVp; Protocol B, 100 kVp/Sn140 kVp).

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