Single-energy versus dual-energy imaging during CT-guided biopsy using dedicated metal artifact reduction algorithm in an in vivo pig model

Purpose To evaluate dual-energy CT (DE) and dedicated metal artifact reduction algorithms (iMAR) during CT-guided biopsy in comparison to single-energy CT (SE). Methods A trocar was placed in the liver of six pigs. CT acquisitions were performed with SE and dose equivalent DE at four dose levels(1.7–13.5mGy). Iterative reconstructions were performed with and without iMAR. ROIs were placed in four positions e.g. at the trocar tip(TROCAR) and liver parenchyma adjacent to the trocar tip(LIVER-1) by two independent observers for quantitative analysis using CT numbers, noise, SNR and CNR. Qualitative image analysis was performed regarding overall image quality and artifacts generated by iMAR. Results There were no significant differences in CT numbers between DE and SE at TROCAR and LIVER-1 irrespective of iMAR. iMAR significantly reduced metal artifacts at LIVER-1 for all exposure settings for DE and SE(p = 0.02-0.04), but not at TROCAR. SNR, CNR and noise were comparable for DE and SE. SNR was best for high dose levels of 6.7/13.5mGy. Mean difference in the Blant-Altman analysis was -8.43 to 0.36. Cohen’s kappa for qualitative interreader-agreement was 0.901. Conclusions iMAR independently reduced metal artifacts more effectively and efficiently than CT acquisition in DE at any dose setting and its application is feasible during CT-guided liver biopsy.

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Reduction of metal artifacts from unilateral hip arthroplasty on dual-energy CT with metal artifact reduction software

Acta Radiologica ◽

10.1177/0284185117731475 ◽

2017 ◽

Vol 59 (7) ◽

pp. 853-860 ◽

Cited By ~ 11

Author(s):

Dong Yue ◽

Cheng Fan Rong ◽

Cai Ning ◽

Hu Liang ◽

Liu Ai Lian ◽

...

Keyword(s):

Image Quality ◽

Hip Arthroplasty ◽

Dual Energy ◽

Observer Agreement ◽

Dual Energy Ct ◽

Artifact Reduction ◽

Metal Artifact ◽

Metal Artifact Reduction ◽

Metal Artifacts ◽

Pelvic Organs

Background The evaluation of hip arthroplasty is a challenge in computed tomography (CT). The virtual monochromatic spectral (VMS) images with metal artifact reduction software (MARs) in spectral CT can reduce the artifacts and improve the image quality. Purpose To evaluate the effects of VMS images and MARs for metal artifact reduction in patients with unilateral hip arthroplasty. Material and Methods Thirty-five patients underwent dual-energy CT. Four sets of VMS images without MARs and four sets of VMS images with MARs were obtained. Artifact index (AI), CT number, and SD value were assessed at the periprosthetic region and the pelvic organs. The scores of two observers for different images and the inter-observer agreement were evaluated. Results The AIs in 120 and 140 keV images were significantly lower than those in 80 and 100 keV images. The AIs of the periprosthetic region in VMS images with MARs were significantly lower than those in VMS images without MARs, while the AIs of pelvic organs were not significantly different. VMS images with MARs improved the accuracy of CT numbers for the periprosthetic region. The inter-observer agreements were good for all the images. VMS images with MARs at 120 and 140 keV had higher subjective scores and could improve the image quality, leading to reliable diagnosis of prosthesis-related problems. Conclusion VMS images with MARs at 120 and 140 keV could significantly reduce the artifacts from hip arthroplasty and improve the image quality at the periprosthetic region but had no obvious advantage for pelvic organs.

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Impact of metal artifact reduction software on image quality of gemstone spectral imaging dual-energy cerebral CT angiography after intracranial aneurysm clipping

Neuroradiology ◽

10.1007/s00234-017-1871-6 ◽

2017 ◽

Vol 59 (9) ◽

pp. 845-852 ◽

Cited By ~ 14

Author(s):

Vincent Dunet ◽

Martine Bernasconi ◽

Steven David Hajdu ◽

Reto Antoine Meuli ◽

Roy Thomas Daniel ◽

...

Keyword(s):

Image Quality ◽

Intracranial Aneurysm ◽

Dual Energy ◽

Artifact Reduction ◽

Metal Artifact ◽

Metal Artifact Reduction ◽

Aneurysm Clipping ◽

Gemstone Spectral Imaging ◽

Cerebral Ct Angiography

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Evaluation of prosthetic complications and tumor recurrence with the single energy metal artifact reduction algorithm in patients with hip tumor prostheses

10.21203/rs.3.rs-121132/v1 ◽

2020 ◽

Author(s):

Fangling Zhang ◽

Xiaoling Zhang ◽

Ling Ma ◽

Ruocheng Li ◽

Zhaohui Zhang ◽

...

Keyword(s):

Tumor Recurrence ◽

Ordinal Scale ◽

Rank Test ◽

Artifact Reduction ◽

Metal Artifact ◽

Metal Artifact Reduction ◽

Metal Artifacts ◽

Signed Rank Test ◽

Ct Attenuation Value ◽

Prosthetic Complications

Abstract Background: To evaluate the effectiveness of the single energy metal artifact reduction (SEMAR) algorithm with a second-generation 320-row multi-detector computed tomography (MDCT) on complications and tumor recurrence detection in patients with hip tumor prostheses.Methods: From February 2016 to June 2019, 31consecutive patients with tumor prostheses of the hip joint underwent CT scans. Lesions were confirmed by histology or clinical and imaging follow-up. Images were reconstructed using 2 methods: iterative (IR) algorithm alone and SEMAR algorithm (IR+ SEMAR). Two radiologists graded the image quality visually by a 6-point (from 0 to 5) ordinal scale. Standard deviations (SD) of CT attenuation value defined as the artifact index (AI) were compared between the two reconstructed methods. Paired sample t-test was adopted to compare the AI values on IR and SEMAR images. Wilcoxon matched-pairs signed rank test was performed to compare the visual scores on IR and SEMAR images. A p- value less than 0.05 was considered statistically significant. Results: The artifacts of the SEMAR images were reduced compared to the Non-SEMAR images (113.94 ±128.54 vs 35.98 ± 53.75HU，t=2.867, P < 0.05). 20 and 16 more lesions were detected by observer 1 and observer 2 with SEMAR algorithm respectively. The mean scores of lesions without SEMAR were 1.39 ± 1.45 (observer 1) and 1.55± 1.34 (observer 2); with SEMAR, the scores were significantly higher, 4.42±0.56 (z=-4.752, p < 0.001) and 4.54± 0.72 (z=-4.837, p < 0.001) respectively. Conclusion: The SEMAR algorithm can effectively reduce metal artifacts in patients with hip tumor prostheses and increase the diagnostic accuracy of prosthetic complications and tumor recurrence.

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