Development of a photon-count spectral (Computed Tomography) CT for human imaging; evaluation of the first human trials of the MARS Spectral CT

The MARS Human CT in similar in design and operation at a conventional CT. The MARS CT scanner consists of an x-ray source and detector rotating around the participant. The only noticeable difference compared to conventional CT is a longer scan duration. Typical MARS scans will be approximately twenty minutes in duration. The MARS Human CT scanner will be used to scan the extremities of up to 200 study participants. One group of up to 100 normal participants will have CT scans of part of the upper and lower extremities on the MARS CT and commercial GE CT scanner . Normal participants may have up to four total scans. Initially participants will be invited to one scan on the MARS scanner and one scan on the GE (or equivalent) scanner. The participant may be invited to have up to two additional scans using revised or newly developed scan protocols as part of a continuous design improvement process. The other group of up to 100 invited participants will be referred by Consultants in rheumatology, orthopeadics, and vascular surgery to have MARS CT of affected limbs in conjunction with standard radiologic imaging. These participants will have a variable number of scans based on consult recommendations. MARS CT scanning will be performed by the MARS Bioimaging Ltd staff at the University of Canterbury, Christchurch, New Zealand, under direction of MCNZ registered physicians and/or registered technologist. Scans on the GE scanner will be performed at Lincoln University, Lincoln, New Zealand. Images of participants will be compared by radiologists and consultants using the technique of Visual Grading Analysis (VGA) to determine if there are differences between scanners or modalities.