Abstract
BackgroundDual-energy computed tomography has shown a great interest for musculoskeletal pathologies. Photon-counting spectral computed tomography (PCSCT) can acquire data in multiple energy bins with the potential to increase contrast, especially for soft tissues. Our objectives were to assess the value of PCSST to characterise cartilage and to extract quantitative measures of subchondral bone integrity.MethodsSeven excised human knees (3 males and 4 females; 4 normal and 3 with osteoarthritis; age 80.6 ± 14 years, mean ± standard deviation) were scanned using a clinical PCSCT prototype scanner. Tomographic image reconstruction was performed after Compton/photoelectric decomposition. Virtual monoenergetic images were generated from 40 keV to 110 keV every 10 keV (cubic voxel size 250 × 250 × 250 μm3). After selecting an optimal virtual monoenergetic image, we analysed the grey level histograms of different tissues and extracted quantitative measurements on bone cysts.ResultsThe optimal monoenergetic images were obtained for 60 keV and 70 keV. Visual inspection revealed that these images provide sufficient spatial resolution and soft-tissue contrast to characterise surfaces, disruption, calcification of cartilage, bone osteophytes, and bone cysts. Analysis of attenuation versus energy revealed different energy fingerprint according to tissues. The volumes and numbers of bone cyst were quantified.ConclusionsVirtual monoenergetic images may provide direct visualisation of both cartilage and bone details. Thus, unenhanced PCSCT appears to be a new modality for characterising the knee joint with the potential to increase the diagnostic capability of computed tomography for joint diseases and osteoarthritis.
Highlights
Dual-energy computed tomography has shown a great interest for musculoskeletal pathologies
Osteoarthritis (OA) is a chronic inflammatory joint disorder characterised by cartilage loss, abnormal subchondral bone, osteophyte formation, degeneration of ligaments, meniscus, and hypertrophy of the capsule [1]
Image analysis First, we investigated the multienergy feature of Photon-counting spectral computed tomography (PCSCT)
Summary
Dual-energy computed tomography has shown a great interest for musculoskeletal pathologies. Photon-counting spectral computed tomography (PCSCT) can acquire data in multiple energy bins with the potential to increase contrast, especially for soft tissues. Osteoarthritis (OA) is a chronic inflammatory joint disorder characterised by cartilage loss, abnormal subchondral bone, osteophyte formation, degeneration of ligaments, meniscus, and hypertrophy of the capsule [1]. Imaging methods used for diagnosis of OA are usually conventional radiography and magnetic resonance imaging, the latter being classically used in clinical routine to visualise joint effusion, cartilage, ligaments, tendons, meniscus, osteophytes, and bone marrow oedema. Computed tomography (CT) is not ideally suited to the observation of soft tissue like cartilage, when combined with intra-articular application of a contrast agent, it can be used to investigate the cartilage surface. CT has been proposed for chondrocalcinosis diagnosis [4], and for quantification of both volume and number of subchondral bone cysts [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
