Abstract
This thesis investigates the potential of the high-resolution MARS spectral photon-counting CT (MARS SPCCT) for musculoskeletal pathologies using phantoms, preclinical and clinical trial studies.
Conventional CT systems, based on the energy-integrating detector, cannot provide information related to individual photon interaction and are limited in many instances due to the design of detectors. As a result, patients with various orthopaedic conditions may need to be imaged with other imaging modalities, such as MRI for bone marrow and soft tissue related pathologies and cone-beam CT or high-resolution peripheral quantitative CT for bone detail and bone health assessment. Therefore, this thesis proposes and validates appropriate image acquisition and processing methodologies and clinical applications of the novel MARS SPCCT system.
Firstly, the system’s stability, reliability, and reproducibility were tested, and image acquisition and processing methods were standardised. Then, contrast mixture and bone marrow simulated phantoms were developed to test the different versions of the material decomposition algorithm and calibrate the material image signal. Next, the system’s potential to identify bone pathologies and to measure bone mineral density was determined in human images from clinical trials. Finally, imaging results from the system were compared with images obtained from existing imaging modalities. The phantom studies showed accuracy and reliability in measuring contrast agents and bone marrow components. Preclinical studies with cartilage samples demonstrated contrast distribution within cartilage for molecular assessment of cartilage health. Imaging results from clinical trials produced acceptable image quality, demonstrated bone pathologies similar to other existing modalities, and enabled opportunistic bone health assessment. Furthermore, high-resolution images produced from the system allowed detailed assessment of bone morphological and pathological features.
In conclusion, this thesis has standardised and developed the MARS SPCCT for human imaging applications as a point-of-care system. Furthermore, it has shown that the system has the potential to diagnose bone and cartilage pathologies and assess bone morphological and pathological features.