Virtual monochromatic imaging in dual‐source dual‐energy CT: Radiation dose and image quality

Yu, Lifeng; Christner, Jodie A.; Leng, Shuai; Wang, Jia; Fletcher, Joel G.

doi:10.1118/1.3658568

Cited by 301 publications

(217 citation statements)

References 33 publications

(40 reference statements)

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“…In conclusion, MEI+ is a very promising algorithm for monoenergetic extrapolation, which is able to overcome noise limitations associated with traditional monoenergetic techniques at low virtual keV levels [5, 13,15]. This algorithm allows an improvement of IHV depiction in the presence of poor contrast.…”

mentioning

confidence: 99%

Assessment of the Hepatic Veins in Poor Contrast Conditions using Dual Energy CT: Evaluation of a Novel Monoenergetic Extrapolation Software Algorithm

Schabel

Bongers

Sedlmair

et al. 2014

Fortschr Röntgenstr

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Purpose: To evaluate a novel monoenergetic post-processing algorithm (MEI+) in patients with poor intrahepatic contrast enhancement. Materials and Methods: 25 patients were retrospectively included in this study. Late-phase imaging of the upper abdomen, which was acquired in dual-energy mode (100/140?kV), was used as a model for poor intrahepatic contrast enhancement. Traditional monoenergetic images (MEI), linearly weighted mixed images with different mixing ratios (MI), sole 100 and 140?kV and MEI+ images were calculated. MEI+ is a novel technique which applies frequency-based mixing of the low keV images and an image of optimal keV from a noise perspective to combine the benefits of both image stacks. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the intrahepatic vasculature (IHV) and liver parenchyma (LP) were objectively measured and depiction of IHV was subjectively rated and correlated with portal venous imaging by two readers in consensus. Results: MEI+ was able to increase the SNR of the IHV (5.7???0.4?at 40keV) and LP (4.9???1.0?at 90keV) and CNR (2.1???0.6?at 40keV) greatly compared to MEI (5.1???1.1?at 80keV, 4.7???1.0?at 80keV, 1.0???0.4?at 70keV), MI (5.2???1.1 M5:5, 4.8???1.0 M5:5, 1.0???3.5 M9:1), sole 100?kV images (4.4???1.0, 3.7???0.8, 1.0???0.3) and 140?kV images (2.8???0.5, 3.1???0.6, 0.1???0.2). Subjective assessment rated MEI+ of virtual 40 keV superior to all other images. Conclusion: MEI+ is a very promising algorithm for monoenergetic extrapolation which is able to overcome noise limitations associated with traditional monoenergetic techniques at low virtual keV levels and consequently does not suffer from a decline of SNR and CNR at low keV values. This algorithm allows an improvement of IHV depiction in the presence of poor contrast. Key points: ??The evaluated new image-based algorithm for virtual monoenergetic imaging allows calculating low virtual keV images from dual energy datasets with significantly improved contrast-to-noise ratios. ??The image based novel monoenergetic extrapolation algorithm applies frequency-based mixing of the low keV images and an image of optimal keV from a noise perspective to combine the benefits of both image stacks. ??When compared to traditional monoenergetic images, the novel monoenergetic algorithm has improved contrast-to-noise ratios for both low and high virtual keV images. ??Contrast-enhanced dual energy images with poor contrast conditions can be significantly improved, e.g. late phase imaging of the liver. Citation Format: ??Schabel C, Bongers M, Sedlmair M et?al. Assessment of the Hepatic Veins in Poor Contrast Conditions using Dual Energy CT: Evaluation of a Novel Monoenergetic Extrapolation Software Algorithm. Fortschr R?ntgenstr 2014; 186: 591???597

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mentioning

confidence: 99%

Assessment of the Hepatic Veins in Poor Contrast Conditions using Dual Energy CT: Evaluation of a Novel Monoenergetic Extrapolation Software Algorithm

Schabel

Bongers

Sedlmair

et al. 2014

Fortschr Röntgenstr

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“…However, there is currently no consensus regarding the optimal kVp for dual-energy metal artifact reduction protocols [20]. In addition, several factors, such as the patient size, prosthesis composition, and dual-energy acquisition method (e.g., dual-source system, rapid kV switching, 2-volume scans with different kV), could influence the effectiveness of dual-energy metal artifact reduction.…”

Section: Discussionmentioning

confidence: 99%

Added value of a single-energy projection-based metal-artifact reduction algorithm for the computed tomography evaluation of oral cavity cancers

et al. 2015

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“…For dual source systems, image-domain basis material decomposition is typically used since the low-and high-energy scans collected in helical mode are not coincident with each other [52].…”

Section: Discussionmentioning

confidence: 99%

Theoretical Comparison of a Dual Energy System and Photon Counting Silicon Detector Used for Material Quantification in Spectral CT

Yveborg

Danielsson

Bornefalk

2015

IEEE Trans. Med. Imaging

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Any method using dual energy computed tomography (CT) has to make prior assumptions in order to quantify k-edge contrast agents. This work estimates the mean square error (MSE) in contrast agent quantification employing a method based on assigning each reconstructed voxel a ratio of soft tissue and fat using dual energy CT. The results are compared to the MSE using a photon counting silicon detector with multiple bins. The square root of the MSEs of the quantifications of iodine and gadolinium for an object consisting of soft tissue and fat using the silicon detector and dual energy CT range from below 2% and 1% of the contrast agent content for 100 mg/cm(3) of iodine and gadolinium, up to approximately 10% and 13%, and 6% and 4%, for 5 mg/cm(3) of iodine and gadolinium, respectively. When adding bone with a voxel volume fraction of 2.2%, the square root of the MSEs of the quantifications of iodine and gadolinium using dual energy CT increases to 25% and 6%, respectively, for 5 mg/cm(3) of contrast agent. In conclusion, results indicate that the noise levels of the material quantification using the silicon detector are higher than the noise levels using a dual energy CT when the composition of the object is known. However, using a dual energy CT increases the risk of model specification error and subsequently a large bias in contrast agent quantification, a problem which does not exist when using a multi-bin CT where the number of energy bins is larger than two.

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Virtual monochromatic imaging in dual‐source dual‐energy CT: Radiation dose and image quality

Cited by 301 publications

References 33 publications

Assessment of the Hepatic Veins in Poor Contrast Conditions using Dual Energy CT: Evaluation of a Novel Monoenergetic Extrapolation Software Algorithm

Assessment of the Hepatic Veins in Poor Contrast Conditions using Dual Energy CT: Evaluation of a Novel Monoenergetic Extrapolation Software Algorithm

Added value of a single-energy projection-based metal-artifact reduction algorithm for the computed tomography evaluation of oral cavity cancers

Theoretical Comparison of a Dual Energy System and Photon Counting Silicon Detector Used for Material Quantification in Spectral CT

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