Reducing artifacts from total hip replacements in dual layer detector CT: Combination of virtual monoenergetic images and orthopedic metal artifact reduction

Neuhaus, Victor; Hokamp, Nils Große; Zopfs, David; Laukamp, Kai Roman; Lennartz, Simon; Abdullayev, Nuran; Maintz, David; Borggrefe, Jan

doi:10.1016/j.ejrad.2018.12.008

Cited by 29 publications

(41 citation statements)

References 25 publications

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“…This might suggest that ARA could also be applicable for other highly attenuating material, i.e., contrast media (20). Further, recent studies showed that the combination of ARA and VMI is often the most effective approach for artifact reduction (21,23). However, the effectiveness of this combined approach has not been investigated for reduction of artifacts resulting from contrast media injection.…”

Section: Introductionmentioning

confidence: 99%

CT artifacts after contrast media injection in chest imaging: evaluation of post-processing algorithms, virtual monoenergetic images and their combination for artifact reduction

Gupta¹,

Obmann²,

Jordan³

et al. 2021

Quant Imaging Med Surg

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Background: After injection into a brachial vein, high contrast media concentration in axillary and subclavian veins can cause artifacts that impair diagnostic utility. This study assessed artifact reduction by artifact-reduction-algorithms (ARA) and virtual-monoenergetic-images (VMI), as well as their combination (VMI ARA ) compared to conventional CT-images (CI).Methods: Forty-six spectral-detector-CT (SDCT) examinations of patients that received ARAreconstructions due to perivenous-artifacts were included in this retrospective study. CI, ARA, VMI, and VMI ARA (range: 70-200 keV) were reconstructed. Objective analysis was performed with ROI-based assessment of mean and standard deviation of attenuation (HU) in hypo-and hyperdense artifacts and impaired muscle and arteries as well as artifact-free reference-tissue. Extent of artifact reduction, assessment of surrounding soft tissue and vessels, and appearance of new artifacts were rated visually by two radiologists.Results: Hypo-and hyperdense artifacts showed significant improvement as evidenced by decreasing attenuation differences between artifact impaired and artifact-free reference tissue in ARA, VMI ≥80 keV, and VMI ARA between 70-200 keV (e.g., CI/ARA/VMI 100keV /VMI ARA100keV : hypodense artifacts, (−)264.8±150.9/ (−)87.1±78.9/(−)48.6±64.6/9.9±63.9 HU; P<0.001); hyperdense artifacts, 164.2±51.1/82.1±73.2/7.9±34.7/ (−)17.3±50.7 HU; P<0.001). Artifacts impairing surrounding muscle and arteries were also reduced by all three approaches. In visual assessment, ARA, VMI ≥100 keV, and VMI ARA between 70-200 keV also showed significant artifact reduction and improved assessment; however, for assessment of arteries improvement was not significant using ARA alone. New artifacts were reported, particularly at higher keV-values. Conclusions:In presence of perivenous-artifacts, ARA, VMI and their combination allow for significant artifact reduction; however, their combination and VMI as a standalone approach yielded best results and should therefore be used, if available.

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Section: Introductionmentioning

confidence: 99%

CT artifacts after contrast media injection in chest imaging: evaluation of post-processing algorithms, virtual monoenergetic images and their combination for artifact reduction

Gupta¹,

Obmann²,

Jordan³

et al. 2021

Quant Imaging Med Surg

Self Cite

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“…Although several approaches were suggested to reduce the artifacts caused by prostheses, including the optimization of single-energy CT scanning (14), iterative reconstructions, and specific software for iterative metal artifact reduction (18,19), these techniques can generate new artifacts, such as blurring and shape distortion (20-26). Moreover, in the study by Bamberg et al ( 23), image quality with DECT was superior to that with single-energy CT in 29 of 31 cases.…”

Section: Discussionmentioning

confidence: 99%

“…Dual-energy CT (DECT) allows virtual monoenergetic imaging (MEI) reconstructions at a high kilovoltage peak. Several studies have demonstrated that these reconstructions, both alone and in combination with iterative metal artifact reconstruction, or IMAR, can improve image quality by reducing metal artifacts in the periprosthetic bone and soft tissues (12)(13)(14)(15)(16)(17). However, there are tube voltages of 80/150 kV, with tin filter, and predefined tube current-time product of 1.6:1 (tube A, 220 mAs; tube B, 138 quality reference mAs) with detector collimation at 32 3 0.6 mm and pitch at 0.6.…”

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confidence: 99%

Diagnostic Performance of Dual-Energy CT for Detecting Painful Hip Prosthesis Loosening

et al. 2021

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Background: Revisions of hip prostheses are increasing, and conventional radiography (CR) is a primary tool for managing complications. However, dual-energy CT (DECT) with virtual monoenergetic imaging is capable of reducing periprosthetic metal artifacts compared with standard CT.Purpose: To compare the diagnostic performance of DECT and CR in detecting hip prosthesis loosening, using surgery as a reference for diagnosis. Materials and Methods:This retrospective single-center study conducted between January 2018 and October 2020 included consecutive patients with unilateral painful hip prostheses. Two independent readers (with 15 years and 4 years of experience) who were blinded to clinical findings evaluated CR and DECT images. At imaging, diagnosis of loosening prosthesis was made for periprosthetic radiolucency greater than or equal to 2 mm wide or the presence of two or more secondary findings, including periprosthetic osteolysis, angulation of the implant, fracture, or abnormal periosteal reaction. For each reader and for each imaging parameter, sensitivity and specificity were calculated. The diagnostic performance of each imaging tool was compared by using the McNemar test. Interobserver agreements were calculated with Cohen κ statistics. Statistical software was used.Results: Overall, 178 patients (mean age ± standard deviation, 74 years ± 20; 96 men) were included (121 undergoing surgery, 57 follow-up). Overall, 87 of 178 patients (49%) were diagnosed with a loosened prosthesis. DECT had higher sensitivity and specificity than CR for both reader 1

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“…To date, few studies have been evaluated the usefulness of MAR and virtual monochromatic images [ 9 10 11 12 13 ]. Most of these studies concluded that the combination yielded optimal artifact reduction, compared to each method alone [ 9 11 12 13 ].…”

Section: Discussionmentioning

confidence: 99%

“…Currently, several vendors offer their own versions of MAR: iterative MAR (iMAR, Siemens Healthineers), MAR for orthopedic implants (O-MAR, Philips Healthcare), single-energy MAR (SEMAR, Canon Medical Systems), and smart MAR (SmartMAR, GE Healthcare) [ 5 6 7 8 ]. A few recent studies have dealt with the combination of virtual monochromatic images and MAR [ 9 10 11 12 13 ]. Bongers et al [ 9 ] and Long et al [ 12 ] showed that combining these two methods showed the best metal artifact reduction.…”

Section: Introductionmentioning

confidence: 99%

Comparison of the Quality of Various Polychromatic and Monochromatic Dual-Energy CT Images with or without a Metal Artifact Reduction Algorithm to Evaluate Total Knee Arthroplasty

et al. 2021

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Objective To compare the quality of various polychromatic and monochromatic images with or without using an iterative metal artifact reduction algorithm (iMAR) obtained from a dual-energy computed tomography (CT) to evaluate total knee arthroplasty. Materials and Methods We included 58 patients (28 male and 30 female; mean age [range], 71.4 [61–83] years) who underwent 74 knee examinations after total knee arthroplasty using dual-energy CT. CT image sets consisted of polychromatic image sets that linearly blended 80 kVp and tin-filtered 140 kVp using weighting factors of 0.4, 0, and −0.3, and monochromatic images at 130, 150, 170, and 190 keV. These image sets were obtained with and without applying iMAR, creating a total of 14 image sets. Two readers qualitatively ranked the image quality (1 [lowest quality] through 14 [highest quality]). Volumes of high- and low-density artifacts and contrast-to-noise ratios (CNRs) between the bone and fat tissue were quantitatively measured in a subset of 25 knees unaffected by metal artifacts. Results iMAR-applied, polychromatic images using weighting factors of −0.3 and 0.0 (P −0.3i and P 0.0i , respectively) showed the highest image-quality rank scores (median of 14 for both by one reader and 13 and 14, respectively, by the other reader; p < 0.001). All iMAR-applied image series showed higher rank scores than the iMAR-unapplied ones. The smallest volumes of low-density artifacts were found in P −0.3i , P 0.0i , and iMAR-applied monochromatic images at 130 keV. The smallest volumes of high-density artifacts were noted in P −0.3i . The CNRs were best in polychromatic images using a weighting factor of 0.4 with or without iMAR application, followed by polychromatic images using a weighting factor of 0.0 with or without iMAR application. Conclusion Polychromatic images combined with iMAR application, P −0.3i and P 0.0i , provided better image qualities and substantial metal artifact reduction compared with other image sets.

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Reducing artifacts from total hip replacements in dual layer detector CT: Combination of virtual monoenergetic images and orthopedic metal artifact reduction

Cited by 29 publications

References 25 publications

CT artifacts after contrast media injection in chest imaging: evaluation of post-processing algorithms, virtual monoenergetic images and their combination for artifact reduction

CT artifacts after contrast media injection in chest imaging: evaluation of post-processing algorithms, virtual monoenergetic images and their combination for artifact reduction

Diagnostic Performance of Dual-Energy CT for Detecting Painful Hip Prosthesis Loosening

Comparison of the Quality of Various Polychromatic and Monochromatic Dual-Energy CT Images with or without a Metal Artifact Reduction Algorithm to Evaluate Total Knee Arthroplasty

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