Quantum noise properties of CT images with anatomical textured backgrounds across reconstruction algorithms: FBP and SAFIRE

Solomon, Justin; Samei, Ehsan

doi:10.1118/1.4893497

Cited by 97 publications

(147 citation statements)

References 52 publications

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“…Two dimensional autocovariance was estimated from the ROI, and the Fourier transform was performed to obtain a 2D NPS map. Assuming in-plane isotropy, the 1D NPS was computed by radially averaging the 2D NPS [11] .…”

Section: Image Analysismentioning

confidence: 99%

“…Individually, each has been studied intensively before leading to the clinical application [3][4][5][6][7][8][9][10] . Lower tube voltage can provide better contrast because iodine preferentially absorbs much more photons at low tube voltage, but at lower tube voltage, images can be undesirably noisy [8][9][10][11] . Iterative reconstructions have been proven to reduce radiation dose notably, but can also alter the noise texture and obscure potential lesions of interest against a "waxy appearance" [5,7,11,12] .…”

Section: Introductionmentioning

confidence: 99%

“…Lower tube voltage can provide better contrast because iodine preferentially absorbs much more photons at low tube voltage, but at lower tube voltage, images can be undesirably noisy [8][9][10][11] . Iterative reconstructions have been proven to reduce radiation dose notably, but can also alter the noise texture and obscure potential lesions of interest against a "waxy appearance" [5,7,11,12] . To optimize protocols, these tradeoffs should be carefully and conjunctively considered.…”

Section: Introductionmentioning

confidence: 99%

“…Inspired by this, our study focused on how size affects image quality with different imaging parameters using a second generation dual source CT scanner (SOMATOM Definition Flash, Siemens Healthcare). Some studies have reported the image quality from this new CT [5,11,13] . However, these studies focused on one particular technique, such as varying tube voltage, varying mAs, or comparing reconstruction methods.…”

Section: Introductionmentioning

confidence: 99%

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Size dependence of inherent image quality of a 2nd generation dual source CT scanner

Zhang

Solomon

Samei

2015

IJDI

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The fast developing CT technologies have complicated the protocol optimization process. Since there are increasing numbers of free parameters that can be adjusted, it is imperative to know exactly how these parameters affect the image quality. This paper examines the effect of varying dose level, tube voltage, reconstruction methods and the AEC function on the CT image quality across different sizes. A size varying phantom, consisting of five cylindrical tiers, was used. To assess the image quality, task transfer function (TTF), noise power spectra (NPS), contrast, and detectability index was computed and compared across sizes. It was found that from small to large size, detectability increased more as the dose increased. When the CTDIvol increased from 0.7 to 22.6 mGy, the detectability for the smallest size section increased by four fold but increased by eight fold for the largest section. Low tube voltage exhibited superior detectability and contrast for all sections, especially for the small size sections, where detectability doubled for the smallest section when tube voltage decreased from 120 kV to 80 kV. TTF curves showed considerable dependence on size, but more pronounced dependence on reconstruction techniques. In conclusion, small size phantoms were affected very differently from large size phantoms by dose levels, reconstruction methods, and tube voltage selection. Low tube voltage and iterative reconstruction technique can deliver superior image quality for small patients. Due to beam hardening and substantially increased noise at low tube voltage for large patients, high tube voltage is still recommended for large patients to retain image quality.

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Section: Image Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Size dependence of inherent image quality of a 2nd generation dual source CT scanner

Zhang

Solomon

Samei

2015

IJDI

Self Cite

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“…The large gap between the performance of the proposed technique and the performances of other techniques is because the proposed technique is developed specially for CT images. CT images were used during the development of the technique to accommodate the inherent properties of images captured using CT machines such as high resolution and quantum noise properties [22]. The performance of any estimation technique depends on the properties of the image considered.…”

mentioning

confidence: 99%

Mean of Median Absolute Derivation Technique for Speckle Noise Variance Estimation in Computerised Tomography Images

2015

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Effect of obesity on ability to lower exposure for detection of low‐attenuation liver lesions

Herts

Schreiner

Dong

et al. 2020

J Applied Clin Med Phys

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Purpose The purpose of this study was to assess the effect of obesity and iterative reconstruction on the ability to reduce exposure by studying the accuracy for detection of low‐contrast low‐attenuation (LCLA) liver lesions on computed tomography (CT) using a phantom model. Methods A phantom with four unique LCLA liver lesions (5‐ to 15‐mm spheres, –24 to –6 HU relative to 90‐HU background) was scanned without (“thin” phantom) and with (“obese” phantom) a 5‐cm thick fat‐attenuation ring at 150 mAs (thin phantom) and 450 mAs (obese phantom) standard exposures and at 33% and 67% exposure reductions. Images were reconstructed using standard filtered back projection (FBP) and with iterative reconstruction (Adaptive Model‐Based Iterative Reconstruction strength 3, ADMIRE). A noninferiority analysis of lesion detection was performed. Results Mean area under the curve (AUC) values for lesion detection were significantly higher for the thin phantom than for the obese phantom regardless of exposure level (P < 0.05) for both FBP and ADMIRE. At 33% exposure reduction, AUC was noninferior for both FBP and ADMIRE strength 3 (P < 0.0001). At 67% exposure reduction, AUC remained noninferior for the thin phantom (P < 0.0035), but was no longer noninferior for the obese phantom (P ≥ 0.7353). There were no statistically significant differences in AUC between FBP and ADMIRE at any exposure level for either phantom. Conclusions Accuracy for lesion detection was not only significantly lower in the obese phantom at all relative exposures, but detection accuracy decreased sooner while reducing the exposure in the obese phantom. There was no significant difference in lesion detection between FBP and ADMIRE at equivalent exposure levels for either phantom.

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Quantum noise properties of CT images with anatomical textured backgrounds across reconstruction algorithms: FBP and SAFIRE

Abstract: Quantum noise properties observed in uniform phantoms may not be representative of those in actual patients for nonlinear reconstruction algorithms. Anatomical texture should be considered when evaluating the performance of CT systems that use such nonlinear algorithms.

Cited by 97 publications

References 52 publications

Size dependence of inherent image quality of a 2nd generation dual source CT scanner

Size dependence of inherent image quality of a 2nd generation dual source CT scanner

Mean of Median Absolute Derivation Technique for Speckle Noise Variance Estimation in Computerised Tomography Images

Effect of obesity on ability to lower exposure for detection of low‐attenuation liver lesions

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