The latest extremity CT machines are designed to provide high quality 3D CT images without the need for a large CT room. This can reduce the need for space, and reduce the time spent using the full size CT, freeing it up and easing the strain on the larger CT rooms, with more expensive technology.
Modern extremity scanners have an open bore to allow easier patient access. This allows weight-bearing studies not possible with traditional CT. Plus, site and install requirements are low to enable a fast, affordable, convenient imaging process for timely diagnosis and commencement of treatment.
These devices have the ability to perform upper and lower extremity 3D exams, including weight bearing. Some devices have step-in patient access for weight-bearing exams. These relatively small CT scanners provide high-resolution 3D images that can help to reveal subtle or occult fractures. They also use a reduced dose when compared to large conventional CT systems. The small footprint of these devices, and simplified design, cut the time and cost of system installation, compared to conventional CT systems.
The latest machines provide high resolution 3D images, partly due to the advanced metal and scatter correction algorithms. They also have reduced noise via algorithmic iterative reconstruction techniques, and the ability to perform both high-resolution 2D and 3D exams.
Simplified user interfaces guide the technologist through the examinations, and they can be pre-programmed with fast equipment setup with auto-positions.
In related academic studies, knee images have been rated as “excellent” or “good” (median scores 5 and 4) for “bone” and “soft tissue” visualization tasks. Hand CT images were rated “excellent” or “adequate” (median scores 5 and 3) for “bone” and “soft tissue” visualization tasks.
Scanner designs now incorporate a host of clinical requirements (e.g., ability to scan the weight‐bearing knee in a natural stance) and have been guided by theoretical and experimental analysis of image quality and dose. The use of these smaller machines may allow hospitals and clinics to keeps the imaging service and potential revenue streams in-house. These devices have the ability to share comprehensive 3D images to facilitate agreement on treatment. Dual operator controls are available for fine positioning.
These smaller CT scanners allow for two scanning orientations, standing, and using the capability for side entry, such as a sitting configuration for imaging of tensioned upper extremity and unloaded lower extremity.
3D image quality is very good, and comparative to conventional CT. Results from recent studies indicate that these system can deliver CT images of the extremities with soft‐tissue contrast resolution comparable to diagnostic CT and improved spatial resolution at potentially reduced dose.
Conclusions
These systems need less space for installation, cost less than conventional CT, can image load‐bearing extremities, and combine volumetric imaging with real‐time fluoroscopy and digital radiography. Extremity CT machines can provide excellent image quality for bone visualization and adequate image quality for soft tissue visualization tasks. These systems complements conventional CT and MR and offers a variety of potential clinical and logistical advantages that are likely to be of benefit to diagnosis, treatment planning, and assessment of therapy response in radiology, orthopaedic surgery, and rheumatology.
Sources:
https://www.carestream.com/en/us/medical/products/carestream-onsight-3d-extremity-system
https://aapm.onlinelibrary.wiley.com/doi/full/10.1118/1.3611039
https://link.springer.com/article/10.1007/s00330-014-3546-6
