Extremity CT Imaging System

The Extremity CT Imaging System is a computed tomography x-ray scanner designed to image the upper limbs (hand and wrist) of adult patients. It uses photon-counting detector technology with helical rotation of a single x-ray source while the patient remains stationary, producing volumetric spectral CT images for diagnosis and treatment planning in professional healthcare facilities.

Key differences from the predicate include: photon-counting detector technology (vs. flat panel with amorphous silicon), continuous x-ray exposure (vs. pulsed), smaller focal spot (0.07 mm vs. 0.50 mm), lower tube current range (0.01-0.35 mA vs. 2-10 mA), single x-ray source (vs. three sources), and helical rotation with z-axis translation (vs. single rotation). Most differences are marked as not raising new safety or effectiveness questions.

FDA Guidance on Medical X-Ray Imaging Devices Conformance with IEC Standards; ISO 10993-1:2018 for biocompatibility; IEC standards applicable to CT systems (Registration 892.1750). Performance testing included water phantom QA, wire phantom QA, contrast resolution, dose measurements (CTDIair, CTDI100), beam quality, and stray radiation assessments.

The device has the same intended use as the predicate (upper extremity CT imaging of adults), uses similar technological principles, and non-clinical performance testing demonstrated comparable image quality and safety characteristics. Clinical testing with board-certified radiologists confirmed diagnostic image quality. The device does not raise new safety or effectiveness issues despite photon-counting detector technology differences.