Table 2.

Overview of representative CT studies. Major results are presented. AUC value was not mentioned unless described. Computed tomography; CT, virtual monoenergetic images; VMI, metal artifact reduction algorithm; MAR, SNR; signal to noise ratio, total knee arthroplasty; TKA, total hip arthroplasty; THA, interclass correlation coefficient; ICC.

	Compared Modalities	Subjects	Results
Lee et al. [55]	Conventional CT VMI (70 and 150 kV)	40 patients with metallic implants	VMI at high kV reduced metal artifacts, increased SNR, and improved image quality.
Donders et al. [56]	VMI Low (70) kV versus high (130–150) kV	41 patients with a clinical suspected non-union with hardware in place. Likert scores were used.	Image quality 1.83 (high kV) > 0.88 (low kV) Number of false-negative non-unions; 5% reduced by high kV. Diagnostic confidence 2.37 (high kV) > 1.43 (low kV)
Barreto et al. [44]	Conventional CT, MAR, VMI	Cadavers with hip bipolar hemiarthroplasty, TKA, and an implant for anterior cervical disc fusion.	Rank of the original 5 points scale Hip; MAR > CT > VMI TKA; MAR > CT > VMI Spine; VMI > MAR > CT
Neuhaus et al. [42]	Conventional CT, MAR, VMI, VMI + MAR	24 patients after THA	VMI + MAR reduced artifacts the most. VMI + MAR improved the assessment of adjacent structures the most.
Andersson et al. [57]	Conventional CT, MAR, VMI, VMI + MAR	Bilateral hip prosthesis phantom	Artifact reduction rate MAR 52–75% VMI 12–52% (in a certain region artifact increased up to 32%) VMI + MAR 75–77%
Bongers et al. [58]	Conventional CT, MAR, VMI, VMI + MAR	Hip prosthesis and dental implants. Qualitative and quantitative evaluation.	Artifact reduction rate (Hip, dental implant, respectively) VMI 33%, 8% MAR 56%, 71% VMI + MAR 76%, 76%
Long et al. [59]	MAR VMI VMI + MAR	20 patients with instrumented spines. Artifact score (1 to 5) Image quality score (1 to 4)	VMI + MAR showed the best artifact and image quality scores. ICC 0.779
Yue et al. [60]	VMI VMI + MAR (80, 100, 120 and 140 kV)	35 patients with THA. Artifact index (AI) CT number Subjective scores	AI in VMI + MAR at 120 and 140 kV were significantly lower than others. Accuracy of CT numbers for the peroprosthetic region improved with VMI + MAR. VMI + MAR at 120 and 140 kV had higher subjective scores.
Chae et al. [61]	Conventional CT MAR VMI VMI + MAR	57 patients with TKA Area of the artifacts Mean attenuation Artifact index (AI) Contrast-to-noise ratio (CNR)	VMI + MAR showed the best performance in artifact reduction and soft tissue depiction. MAR depicted bony structures the best.