MRI should be considered in any case with posterior placenta previa and suspicion of accreta, in any case with clinical suspicion for accreta and discordant US findings, and in any case in which percreta is suspected.

Magnetic resonance imaging systems rely on signal detection via radiofrequency coil arrays which, ideally, need to provide both bendability and form-fitting stretchability to conform to the imaging volume. However, most commercial coils are rigid and of fixed size with a substantial mean offset distance of the coil from the anatomy, which compromises the spatial resolution and diagnostic image quality as well as patient comfort. Here, we propose a soft and stretchable receive coil concept based on liquid metal and ultra-stretchable polymer that conforms closely to a desired anatomy. Moreover, its smart geometry provides a self-tuning mechanism to maintain a stable resonance frequency over a wide range of elongation levels. Theoretical analysis and numerical simulations were experimentally confirmed and demonstrated that the proposed coil withstood the unwanted frequency detuning typically observed with other stretchable coils (0.4% for the proposed coil as compared to 4% for a comparable control coil). Moreover, the signal-to-noise ratio of the proposed coil increased by more than 60% as compared to a typical, rigid, commercial coil.

Clinical applications of 3D printing are increasingly commonplace, likewise the frequency of inclusion of 3D printed objects on imaging studies. Although there is a general familiarity with the imaging appearance of traditional materials comprising common surgical hardware and medical devices, comparatively less is known regarding the appearance of available 3D printing materials in the consumer market. This work detailing the CT appearance of a selected number of common filament polymer classes is an initial effort to catalog these data, to provide for accurate interpretation of imaging studies incidentally or intentionally including fabricated objects. Furthermore, this information can inform the design of image-realistic tissue-mimicking phantoms for a variety of applications, with clear candidate material analogs for bone, soft tissue, water, and fat attenuation.

Objectives/Hypothesis A limited number of three‐dimensionally (3D)‐printed laryngeal simulators have been described in the literature, only one of which is specifically designed for percutaneous injection laryngoplasty (PIL) training and is currently of limited availability. This study describes the development and evaluation of a high‐fidelity, open‐source, low‐cost 3D‐printed simulator for PIL training, improving on existing models. Study Design Simulator design and survey evaluation. Methods Computed tomography scans of the upper airways were processed with 3D Slicer to generate a computer model of the endolarynx. Blender and Fusion 360 were used to refine the mucosal model and develop casts for silicone injection molding. The casted endolaryngeal structures were inserted into a modified version of a publicly available laryngeal cartilage model. The final models were evaluated by 10 expert laryngologists using a customized version of the Michigan Standard Simulation Experience Scale. Internal consistency and interrater reliability of the survey were evaluated using Cronbach's α and intraclass correlation, respectively. Results Expert laryngologists highly rated the model for measures of fidelity, educational value, and overall quality (mean = 4.8, standard deviation = 0.5; 1 = strongly disagree, 5 = strongly agree). All reviewers rated the model as ready for use as is or with slight modifications. The filament needed for one cartilage model costs $0.96, whereas the silicone needed for one soft‐tissue model costs $1.89. Conclusions Using 3D‐printing technology, we successfully created the first open‐source, low‐cost, and anatomically accurate laryngeal model for injection laryngoplasty training. Our simulator is made freely available for download on Wikifactory with step‐by‐step tutorials for 3D printing, silicone molding, assembly, and use. Level of Evidence NA Laryngoscope, 131:E890–E895, 2021

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