Dual-energy CT angiography-derived virtual non-contrast images for follow-up of patients with surgically clipped aneurysms: a retrospective study
- 29 Downloads
To evaluate the diagnostic performance, image quality, artifacts, and radiation doses of virtual non-contrast (VNC) images, relative to true non-contrast (TNC) images, in patients with surgically clipped aneurysms.
Seventy-six patients who underwent unenhanced computed tomography (CT) and dual-energy (DE)-CT angiography after surgical clipping of 85 intracranial aneurysms were included in the study. Diagnostic performances of VNC and TNC images were compared with respect to sensitivity, specificity, and positive and negative predictive values. The results of quantitative and qualitative analyses were compared between VNC and TNC images. Radiation doses were also compared between VNC and TNC images.
Diagnostic performance of VNC images was lower than that of TNC images; however, addition of contrast-enhanced images improved diagnostic performance. Image noise and mean attenuation of VNC images were significantly higher than those of TNC images in the centrum semiovale, cerebellum, and pons. The quality of VNC images was excellent or sufficient (85.5% for observer 1, 85.5% for observer 2), and complete acceptance of VNC images was achieved in 64.5% for observer 1 and in 71.0% for observer 2; however, the addition of contrast-enhanced images increased the level of acceptance (92.0% for observer 1, 90.9% for observer 2). Clip artifacts were significantly lower in VNC images than in TNC images. CT dose index, dose-length product, and effective dose were significantly lower without TNC images.
VNC images showed lower diagnostic performance and image quality, and higher image noise than TNC images; however, VNC images could reduce clip artifacts and radiation doses.
KeywordsDual-energy CT angiography Virtual non-contrast Surgical clipping Brain
Compliance with ethical standards
This study was funded by the DongKook Life Science. Co., Ltd., Republic of Korea.
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures were performed in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study formal consent is not required.
For this type of retrospective study formal consent is not required.
- 4.Jiang L, He Z-H, Zhang X-D, Lin B, Yin X-H, Sun X-C (2011) Value of noninvasive imaging in follow-up of intracranial aneurysm. Acta Neurochir Suppl 110:227–232Google Scholar
- 6.De Cecco CN, Darnell A, Macías N, Ayuso JR, Rodríguez S, Rimola J, Pagés M, García-Criado Á, Rengo M, Laghi A (2013) Virtual unenhanced images of the abdomen with second-generation dual-source dual-energy computed tomography: image quality and liver lesion detection. Investig Radiol 48:1–9CrossRefGoogle Scholar
- 21.Zhang L-J, Wu S-Y, Niu J-B, Zhang Z-L, Wang HZ, Zhao Y-E, Chai X, Zhou C-S, Lu G-M (2010) Dual-energy CT angiography in the evaluation of intracranial aneurysms: image quality, radiation dose, and comparison with 3D rotational digital subtraction angiography. Am J Roentgenol 194:23–30CrossRefGoogle Scholar
- 23.Winklhofer S, Hinzpeter R, Stocker D, Baltsavias G, Michels L, Burkhardt J-K, Regli L, Valavanis A, Alkadhi H (2018) Combining monoenergetic extrapolations from dual-energy CT with iterative reconstructions: reduction of coil and clip artifacts from intracranial aneurysm therapy. Neuroradiology 60:1–11CrossRefGoogle Scholar
- 27.Tawfik AM, Kerl JM, Bauer RW, Nour-Eldin N-E, Naguib NN, Vogl TJ, Mack MG (2012) Dual-energy CT of head and neck cancer: average weighting of low-and high-voltage acquisitions to improve lesion delineation and image quality—initial clinical experience. Investig Radiol 47:306–311CrossRefGoogle Scholar
- 29.Christner JA, Kofler JM, McCollough CH (2010) Estimating effective dose for CT using dose–length product compared with using organ doses: consequences of adopting international commission on radiological protection publication 103 or dual-energy scanning. Am J Roentgenol 194:881–889CrossRefGoogle Scholar
- 37.Chen GZ, Zhang LJ, Schoepf UJ, Wichmann JL, Milliken CM, Zhou CS, Qi L, Luo S, Lu GM (2015) Radiation dose and image quality of 70 kVp cerebral CT angiography with optimized sinogram-affirmed iterative reconstruction: comparison with 120 kVp cerebral CT angiography. Eur Radiol 25:1453–1463CrossRefGoogle Scholar