Low-radiation dose scan protocol for preoperative imaging for dental implant surgery using deep learning-based reconstruction in multidetector CT

Purpose Maxillofacial trauma predominantly affects young adults between 20 and 40 years of age. Although radioprotection is a legal requirement, the significant potential of dose reduction in computed tomography (CT) is still underused in the clinical routine. The objective of this study was to evaluate whether maxillofacial fractures can be reliably detected and classified using ultra-low-dose CT. Materials and Methods CT images of 123 clinical cases with maxillofacial fractures were classified by two readers using the AOCOIAC software and compared with the corresponding results from post-treatment images. In group 1, consisting of 97 patients with isolated facial trauma, pre-treatment CT images at different dose levels (volumetric computed tomography dose index: ultra-low dose, 2.6 mGy; low dose, <10 mGy; and regular dose, <20 mGy) were compared with post-treatment cone-beam computed tomography (CBCT). In group 2, consisting of 31 patients with complex midface fractures, pre-treatment shock room CT images were compared with post-treatment CT at different dose levels or CBCT. All images were presented in random order and classified by 2 readers blinded to the clinical results. All cases with an unequal classification were re-evaluated. Results In both groups, ultra-low-dose CT had no clinically relevant effect on fracture classification. Fourteen cases in group 2 showed minor differences in the classification code, which were no longer obvious after comparing the images directly to each other. Conclusion Ultra-low-dose CT images allowed the correct diagnosis and classification of maxillofacial fractures. These results might lead to a substantial reconsideration of current reference dose levels.

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“… 16 The most recent deep-learning-based reconstructions could enable further optimization of ultra-low-dose image quality. 17 …”

Section: Discussionmentioning

confidence: 99%

Can ultra-low-dose computed tomography reliably diagnose and classify maxillofacial fractures in the clinical routine?

et al. 2023

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Improvement of image quality of dentomaxillofacial region in ultra-high-resolution CT: a phantom study

Sakai,

Okamura,

Kitamoto

et al. 2024

Dentomaxillofacial Radiology

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Objectives The purpose of this study was to compare the image quality of ultra-high-resolution computed tomography (U-HRCT) with that of conventional multi-detector row CT (convCT) and demonstrate its usefulness in the dentomaxillofacial region. Methods Phantoms were helically scanned with U-HRCT and convCT scanners using clinical protocols. In U-HRCT, phantoms were scanned in super-high-resolution (SHR) mode, and hybrid iterative reconstruction (HIR) and filtered-back projection (FBP) techniques were performed using a bone kernel (FC81). The FBP technique was performed using the same kernel as in convCT (reference). Two observers independently evaluated the 54 resulting images using a 5-point scale (5: excellent diagnostic image quality; 4: above average; 3: average; 2: subdiagnostic; and 1: unacceptable). The system performance function (SPF) was calculated for a comprehensive evaluation of the image quality using the task transfer function and noise power spectrum. Statistical analysis using the Kruskal-Wallis test was performed to compare the image quality among the three protocols. Results The observers assigned higher scores to images acquired with the SHRHIR and SHRFBP protocols than to those acquired with the reference (p < 0.0001 and p < 0.0001, respectively). The relative SPF value at 1.0 cycles/mm in SHRHIR and SHRFBP compared to the reference protocol were 151.5 and 45.6%, respectively. Conclusions Through phantom experiments, this study demonstrated that U-HRCT can provide superior-quality images compared to conventional CT in the dentomaxillofacial region. The development of a better image reconstruction method is required to improve image quality and optimise the radiation dose.

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Regional ventilation dynamics of electrical impedance tomography validated with four-dimensional computed tomography: single-center, prospective, observational study

Katayama,

Tonai,

Nakamura

et al. 2024

Crit Care

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Background The dynamic regional accuracy of electrical impedance tomography has not yet been validated. We aimed to compare the regional accuracy of electrical impedance tomography with that of four-dimensional computed tomography during dynamic ventilation. Methods This single-center, prospective, observational study conducted in a general intensive care unit included adult patients receiving mechanical ventilation from July 2021 to February 2024. The patients were mechanically ventilated passively and underwent electrical impedance tomography and four-dimensional computed tomography on the same day. Results Overall, 45 patients were analyzed. The correlation coefficients in regional dynamic ventilation between four-dimensional computed tomography and electrical impedance tomography in each region were 0.963, 0.963, 0.835 (ventral, central, and dorsal, respectively) in the right lung and 0.947, 0.927, 0.823 (ventral, central, and dorsal, respectively) in the left lung. The correlation coefficient was low when the regional ventilation distribution detected by the electrical impedance tomography was < 2%. After excluding nine patients with a regional ventilation distribution of < 2%, the ventral, central, and dorsal correlation coefficients were 0.963, 0.963, and 0.946 in the right lung and 0.942, 0.924, and 0.951, respectively, in the left lung. Conclusions Regional ventilation using electrical impedance tomography during dynamic ventilation was highly accurate and consistent with the time phase compared to four-dimensional computed tomography. Given the high correlation between these modalities, they can contribute significantly to further studies on regional ventilation dynamics. Trial registration number ClinicalTrials.gov (No. UMIN00044386). Supplementary Information The online version contains supplementary material available at 10.1186/s13054-024-05130-8.

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Low-radiation dose scan protocol for preoperative imaging for dental implant surgery using deep learning-based reconstruction in multidetector CT

Cited by 4 publications

References 20 publications

Can ultra-low-dose computed tomography reliably diagnose and classify maxillofacial fractures in the clinical routine?

Can ultra-low-dose computed tomography reliably diagnose and classify maxillofacial fractures in the clinical routine?

Improvement of image quality of dentomaxillofacial region in ultra-high-resolution CT: a phantom study

Regional ventilation dynamics of electrical impedance tomography validated with four-dimensional computed tomography: single-center, prospective, observational study

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