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Mobile C-Arm with a CMOS Detector: Technical Assessment of Fluoroscopy and Cone-Beam CT Imaging Performance.

A new interesting article has been published in Med Phys. 2018 Oct 19. doi: 10.1002/mp.13244. [Epub ahead of print] and titled:

Mobile C-Arm with a CMOS Detector: Technical Assessment of Fluoroscopy and Cone-Beam CT Imaging Performance.

Authors of this article are:

Sheth NM, Zbijewski W, Jacobson MW, Abiola G, Kleinszig G, Vogt S, Soellradl S, Bialkowski J, Anderson WS, Weiss CR, Osgood GM, Siewerdsen JH.

A summary of the article is shown below:

PURPOSE: Indirect-detection CMOS flat-panel detectors (FPDs) offer fine pixel pitch, fast readout, and low electronic noise in comparison to current a-Si:H FPDs. This work investigates the extent to which these potential advantages affect imaging performance in mobile C-arm fluoroscopy and cone-beam CT (CBCT).METHODS: FPDs based on CMOS (Xineos 3030HS, 0.151 mm pixel pitch) or a-Si:H (PaxScan 3030X, 0.194 mm pixel pitch) sensors were outfitted on equivalent mobile C-arms for fluoroscopy and CBCT. Technical assessment of 2D and 3D imaging performance included measurement of electronic noise, gain, lag, modulation transfer function (MTF), noise-power spectrum (NPS), detective quantum efficiency (DQE), and noise-equivalent quanta (NEQ) in fluoroscopy (with entrance air kerma ranging 5 – 800 nGy per frame) and cone-beam CT (with weighted CT dose index, CTDIw , ranging 0.08 – 1 mGy). Image quality was evaluated by clinicians in vascular, orthopaedic, and neurological surgery in realistic interventional scenarios with cadaver subjects emulating a variety of 2D and 3D imaging tasks.RESULTS: The CMOS FPD exhibited ~2-3x lower electronic noise and ~7x lower image lag than the a-Si:H FPD. The 2D (projection) DQE was superior for CMOS at ≤50 nGy per frame, especially at high spatial frequencies (~2% improvement at 0.5 mm-1 and ≥50% improvement at 2.3 mm-1 ) and was somewhat inferior at moderate-high doses (up to 18% lower DQE for CMOS at 0.5 mm-1 ). For smooth CBCT reconstructions (low-frequency imaging tasks), CMOS exhibited ~10-20% higher NEQ (at 0.1-0.5 mm-1 ) at the lowest dose levels (CTDIw ≤0.1 mGy), while the a-Si:H system yielded slightly (~5%) improved NEQ (at 0.1-0.5 lp/mm) at higher dose levels (CTDIw ≥ 0.6 mGy). For sharp CBCT reconstructions (high-frequency imaging tasks), NEQ was ~32% higher above 1 mm-1 for the CMOS system at mid-high dose levels and ≥75% higher at the lowest dose levels (CTDIw ≤0.1 mGy). Observer assessment of 2D and 3D cadaver images corroborated the objective metrics with respect to a variety of pertinent interventional imaging tasks.CONCLUSION: Measurements of image noise, spatial resolution, DQE, and NEQ indicate improved low-dose performance for the CMOS-based system, particularly at lower doses and higher spatial frequencies. Assessment in realistic imaging scenarios confirmed improved visibility of fine details in low-dose fluoroscopy and CBCT. The results quantify the extent to which CMOS detectors improve mobile C-arm imaging performance, especially in 2D and 3D imaging scenarios involving high-resolution tasks and low-dose conditions. This article is protected by copyright. All rights reserved.This article is protected by copyright. All rights reserved.

Check out the article’s website on Pubmed for more information:

This article is a good source of information and a good way to become familiar with topics such as:

CMOS ; DQE ; NEQ ; NPS ;C-arm;amorphous silicon;cone-beam CT;flat-panel detector;fluoroscopy;image-guided procedures;spatial resolution;technical assessment


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