Dual-energy CT with virtual monochromatic images and metal artifact reduction software for reducing metallic dental artifacts

Background Metallic dental prostheses may degrade image quality on head and neck computed tomography (CT). However, there is little information available on the use of dual-energy CT (DECT) and metal artifact reduction software (MARS) in the head and neck regions to reduce metallic dental artifacts. Purpose To assess the usefulness of DECT with virtual monochromatic imaging and MARS to reduce metallic dental artifacts. Material and Methods DECT was performed using fast kilovoltage (kV)-switching between 80-kV and 140-kV in 20 patients with metallic dental prostheses. CT data were reconstructed with and without MARS, and with synthesized monochromatic energy in the range of 40–140-kiloelectron volt (keV). For quantitative analysis, the artifact index of the tongue, buccal, and parotid areas was calculated for each scan. For qualitative analysis, two radiologists evaluated 70-keV and 100-keV images with and without MARS for tongue, buccal, parotid areas, and metallic denture. The locations and characteristics of the MARS-related artifacts, if any, were also recorded. Results DECT with MARS markedly reduced metallic dental artifacts and improved image quality in the buccal area ( P < 0.001) and the tongue ( P < 0.001), but not in the parotid area. The margin and internal architecture of the metallic dentures were more clearly delineated with MARS ( P < 0.001) and in the higher-energy images than in the lower-energy images ( P = 0.042). MARS-related artifacts most commonly occurred in the deep center of the neck. Conclusion DECT with MARS can reduce metallic dental artifacts and improve delineation of the metallic prosthesis and periprosthetic region.

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Combination of Iterative Metal Artifact Reduction and Virtual Monoenergetic Reconstruction Using Split-Filter Dual-Energy CT in Patients With Dental Artifact on Head and Neck CT

American Journal of Roentgenology ◽

10.2214/ajr.21.26772 ◽

2021 ◽

Author(s):

Alexander Marcel Alfred Schmidt ◽

Jan-Peter Grunz ◽

Bernhard Petritsch ◽

Philipp Gruschwitz ◽

Jonas Knarr ◽

...

Keyword(s):

Head And Neck ◽

Dual Energy ◽

Dual Energy Ct ◽

Artifact Reduction ◽

Metal Artifact ◽

Metal Artifact Reduction

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Metal About the Hip and Artifact Reduction Techniques: From Basic Concepts to Advanced Imaging

Seminars in Musculoskeletal Radiology ◽

10.1055/s-0039-1687898 ◽

2019 ◽

Vol 23 (03) ◽

pp. e68-e81 ◽

Cited By ~ 6

Author(s):

Iman Khodarahmi ◽

Amanda Isaac ◽

Elliot K. Fishman ◽

Danoob Dalili ◽

Jan Fritz

Keyword(s):

Image Quality ◽

Pulse Sequences ◽

Dual Energy Ct ◽

Artifact Reduction ◽

Metal Artifact ◽

Metal Artifact Reduction ◽

Reconstruction Algorithms ◽

Radiographic Findings ◽

Reduction Techniques ◽

Ct Data

AbstractPromising outcomes of hip replacement interventions in this era of aging populations have led to higher demands for hip arthroplasty procedures. These require effective methods and techniques for the detection of postoperative outcomes and complications. Based on the presence or absence of radiographic findings, magnetic resonance imaging (MRI) and computed tomography (CT) may be required to detect and further characterize different causes of failing implants. Yet metal-related artifacts degrade image quality and pose significant challenges for adequate image quality. To mitigate such artifacts in MRI, a set of techniques, collectively known as metal artifact reduction sequence (MARS) MRI, were developed that optimize the framework of the conventional pulse sequences and exploit novel multispectral and multispatial imaging methods such as Slice Encoding for Metal Artifact Correction (SEMAC) and Multi-Acquisition Variable-Resonance Image Combination (MAVRIC). Metal-induced artifacts on CT can be effectively reduced with virtual monochromatic reconstruction of dual-energy CT data sets, metal artifact reduction reconstruction algorithms, and postprocessing image visualization techniques.

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CT venography after knee replacement surgery: comparison of dual-energy CT-based monochromatic imaging and single-energy metal artifact reduction techniques on a 320-row CT scanner

Acta Radiologica Open ◽

10.1177/2058460117693463 ◽

2017 ◽

Vol 6 (2) ◽

pp. 205846011769346 ◽

Cited By ~ 6

Author(s):

Masafumi Kidoh ◽

Daisuke Utsunomiya ◽

Seitaro Oda ◽

Takeshi Nakaura ◽

Yoshinori Funama ◽

...

Keyword(s):

Knee Replacement ◽

Dual Energy ◽

Dual Energy Ct ◽

Artifact Reduction ◽

Metal Artifact ◽

Metal Artifact Reduction ◽

Knee Replacement Surgery ◽

Monochromatic Imaging ◽

Replacement Surgery ◽

The Mean

Background An optimal metal artifact reduction (MAR) technique is needed for a reliable and accurate image-based diagnosis. Purpose Using a 320-row scanner, we compared the dual-energy computed tomography (CT)-based monochromatic and the single-energy metal artifact reduction (SEMAR) techniques for CT venography (CTV) to identify the better imaging method for diagnosing deep vein thrombosis (DVT) in patients who had undergone knee replacement surgery. Material and Methods Twenty-three consecutive patients with suspected DVT after unilateral knee replacement surgery underwent dual-energy CT (135/80 kVp). Monochromatic images of 35–135 keV were generated; the monochromatic image with the best signal-to-noise ratio (SNR) of the popliteal vein near the metal prosthesis were selected. The projection data of 80 kVp were reconstructed using MAR algorithm. The mean SNR ON MAR and the best SNR ON monochromatic images were compared. Two radiologists evaluated visualization of the metal artifacts on a four-point scale where 1 = extensive artifacts, 2 = strong artifacts, 3 = mild artifacts, and 4 = minimal artifacts. Results The mean SNR was significantly higher on the MAR than the monochromatic images (12.8 ± 4.7 versus 7.7 ± 5.1, P < 0.01) and the visual scores were significantly higher for MAR than monochromatic images (2.6 ± 0.8 versus 1.3 ± 0.4, P < 0.01). Conclusion For CTV after knee replacement surgery, the MAR technique is superior to the monochromatic imaging technique.

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Metal Artifact Reduction Software Used With Abdominopelvic Dual-Energy CT of Patients With Metal Hip Prostheses: Assessment of Image Quality and Clinical Feasibility

American Journal of Roentgenology ◽

10.2214/ajr.13.10980 ◽

2014 ◽

Vol 203 (4) ◽

pp. 788-795 ◽

Cited By ~ 54

Author(s):

Seung Chol Han ◽

Yong Eun Chung ◽

Young Han Lee ◽

Kwan Kyu Park ◽

Myeong Jin Kim ◽

...

Keyword(s):

Image Quality ◽

Dual Energy ◽

Dual Energy Ct ◽

Artifact Reduction ◽

Metal Artifact ◽

Metal Artifact Reduction ◽

Hip Prostheses

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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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