Can dual-energy computed tomography improve visualization of hypoenhancing liver lesions in portal venous phase? Assessment of advanced image-based virtual monoenergetic images

Caruso, Damiano; Cecco, Carlo N. De; Schoepf, U. Joseph; Schaefer, Amanda R.; Leland, Parker W.; Johnson, Dustin; Laghi, Andréa; Hardie, Andrew D.

doi:10.1016/j.clinimag.2016.10.015

Cited by 49 publications

(34 citation statements)

References 17 publications

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“…In addition, the lesion conspicuity of hypo- or hyper-attenuating FLLs in large phantoms were improved in VMI compared with polychromatic images, especially in low-contrast FLLs. Our study results were also well matched with the results of recent studies which demonstrated improved visualization of hypoattenuating liver lesions [35, 43, 44] or hyperattenuating liver lesions [36] using advanced image-based virtual monochromatic images with a recent dual source DECT system compared with SECT scan. In addition, the lesion conspicuity of low-contrast FLLs was significantly improved in VMI compared to polychromatic images (DRI 16, P = 0.01; DRI 19, P = 0.02; DRI 22, P = 0.05), although there was no significant difference among high-contrast FLL images.…”

Section: Discussionsupporting

confidence: 89%

Value of virtual monochromatic spectral image of dual-layer spectral detector CT with noise reduction algorithm for image quality improvement in obese simulated body phantom

Kang

Lee

et al. 2019

BMC Med Imaging

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Background Dual-layer spectral detector CT (SDCT) may provide several theoretical advantages over pre-existing DECT approaches in terms of adjustment-free sampling number and dose modulation, beam hardening correction, and production spectral images by post-processing. In addition, by adopting noise reduction algorithm, high contrast resolution was expected even in low keV level. We surmised that this improvement would be beneficial to obese people. Therefore, our aim of study is to compare image quality of virtual monochromatic spectral images (VMI) and polychromatic images reconstructed from SDCT with different body size and radiation dose using anthropomorphic liver phantom. Methods One small and one large size of body phantoms, each containing eight (four high- and four low-contrast) simulated focal liver lesions (FLLs) were scanned by SDCT (at 120 kVp) using different Dose Right Indexes (DRIs). VMI were reconstructed from spectral base images from 40 keV to 200 keV. Hybrid iterative reconstruction (iDose 4 ) was used for polychromatic image reconstruction. Image noise and contrast to noise ratio (CNR) were compared. Five radiologists independently rated lesion conspicuity, diagnostic acceptability and subjective noise level in every image sets, and determined optimal keV level in VMI. Results Compare with conventional polychromatic images, VMI showed superior CNR at low keV level regardless of phantom size at every examined DRIs (Ps < 0.05). As body size increased, VMI had more gradual CNR decrease and noise increase than conventional polychromatic images. For low contrast FLLs in large phantom, lesion conspicuities at low radiation dose levels (DRI 16 and 19) were significantly increased in VMI (Ps < 0.05). Subjective image noise and diagnostic acceptabilities were significantly improved at VMI in both phantom size. Conclusions VMI of dual-layer spectral detector CT with noise reduction algorithm provides improved CNR, noise reduction, and better subjective image quality in imaging of obese simulated liver phantom compared with polychromatic images. This may hold promise for improving detection of liver lesions and improved imaging of obese patients.

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Section: Discussionsupporting

confidence: 89%

Value of virtual monochromatic spectral image of dual-layer spectral detector CT with noise reduction algorithm for image quality improvement in obese simulated body phantom

Kang

Lee

et al. 2019

BMC Med Imaging

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“…7-9). [24][25][26] Iodine quantification images often displayed as colorcoded iodine maps, are useful for assessing treatment response after therapy. [27][28][29] Assessing for residual disease after locoregional therapy is often difficult on conventional CT due to the presence of hyperdense hemorrhagic necrosis that is often present within the treatment bed.…”

Section: Mectmentioning

confidence: 99%

Imaging of Liver Metastases

2017

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“…Dual-energy CT is especially useful for providing accurate iodine quantifications, a vital contrast agent in many CT examinations, and in improving the detectability of iodine enhancing structures due to higher iodine contrast and reduced beam-hardening artifacts through virtual mono-energetic imaging. 20,21 The importance of quantitative PET imaging as a biomarker for assessing response to therapy in oncological patients as new therapeutic options emerge is already a consensus. 2 At the same time, since the introduction of DECT, the importance of CT in oncological diagnostics and treatment assessment continues to steadily increase.…”

Section: Introductionmentioning

confidence: 99%

Quantitative positron emission tomography imaging in the presence of iodinated contrast media using electron density quantifications from dual‐energy computed tomography

et al. 2020

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Purpose As preparation for future positron emission tomography (PET)/dual‐energy computed tomography (DECT)T imaging modality and new possible clinical applications, the study aimed to evaluate the utility of clinically available spectral results from a DECT system for improving attenuation corrections of PET acquisitions in the presence of iodinated contrast media. The dependence of the accuracy of PET quantification values, reconstructed with conventional and spectral‐based attenuation corrections, was examined as a function of the amount of iodine content and x‐ray radiation exposure. Methods Measurements were performed on commercial PET/CT and DECT systems, using a semi‐anthropomorphic phantom with seven centrifuge tubes in its bore. Five different configurations of tube contents were scanned by both PET/CT and DECT. With the aim of mimicking clinically observed concentrations, in all phantom configurations the center tube contained a high concentration of radionuclide while the peripheral tubes contained a lower concentration of radionuclide. Iodine content was incrementally increased between phantom configurations by replacing iodine‐free tubes with tubes that contained the original radionuclide concentration within a 10 mg/ml iodine dilution. DECT‐based attenuation correction maps were generated by scaling electron density spectral results into corresponding 511 keV photon linear attenuation coefficients. Results Mean SUV values obtained from the nominal PET reconstruction, using conventional CT images as input for the attenuation correction, demonstrate a monotonic increase of 8.6% when the water and radionuclide mixtures were replaced by iodine, water, and radionuclide (same level of activity) mixture. Mean SUV values obtained from the DECT‐based reconstruction, in which the attenuation correction utilizes electron density values as input, demonstrate different, more stable behavior across all iodine insert configurations, with a standard deviation to mean ratio of less than 1%. This observed behavior was independent of the area size used for measurement. A minor radiation dose dependency of the electron density values (below 0.5%) was observed. This resulted in consistent (iodine independent) PET quantification behavior, which persisted even at the lowest radiation dose levels tested in our experiment, that is, 25% of the radiation dose utilized for CT acquisition in the clinical PET/CT protocol. Conclusions Utilization of DECT‐generated electron density estimations for attenuation correction benefit PET quantification consistency in the presence of iodine and at nominal and low DECT radiation exposure levels. The ability to correctly account for iodinated contrast media in PET acquisitions will allow the development of new clinical applications that rely on the quantitative capabilities of spectral CT technologies and modern PET systems.

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Can dual-energy computed tomography improve visualization of hypoenhancing liver lesions in portal venous phase? Assessment of advanced image-based virtual monoenergetic images

Cited by 49 publications

References 17 publications

Value of virtual monochromatic spectral image of dual-layer spectral detector CT with noise reduction algorithm for image quality improvement in obese simulated body phantom

Value of virtual monochromatic spectral image of dual-layer spectral detector CT with noise reduction algorithm for image quality improvement in obese simulated body phantom

Imaging of Liver Metastases

Quantitative positron emission tomography imaging in the presence of iodinated contrast media using electron density quantifications from dual‐energy computed tomography

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