==> Conventional CT (CCT)
CT is characterized by excellent resolution and high contrast, hence it is the best technique for the assessment and characterization of crystal arthropathies . CCT is not helpful in the diagnosis of acute gout as it can’t detect inflammation, synovitis, tenosynovitis and osteitis. This handicap is however, more than counterbalanced by its role in chronic gout. It is able to detect erosions better than Magnetic Resonance Imag¬ing (MRI) or CR . These are described as well defined, punched out lytic bone lesions, with sclerotic overhanging edges .
The specificity of CCT for the assessment of tophi exceeds that of US or MRI. CT of tophi has been confirmed microscopically by identifying MSU crystals . Its measurement of tophi has also been compared to physical exam using Vernier calipers [81,82]. Tophi, soft tissue, intra-articular as well as intra-osseous ones appear as soft tissue masses with well described attenuation, making it easier to distinguish them from other soft tissue lesions CCT can help to monitor disease burden and response to therapy , but has the disadvantage of radiation exposure.
Dual-Energy CT (DECT) : The introduction of this new imaging technique opened a new horizon. It allows the differentiation of deposits based on their dif¬ferent X-ray spectra. It applies the concept that the attenuation of tissues depends on their density, atomic number as well as the ate), depending on the degree of its hydration and classification]. MRI role is limited because of expense and limited availability. It is, however, useful for evaluation of gout at unusual sites. The literature abounds with case reports in the axial skeleton , or presentation as spondyloarthritis, carpal tunnel syndrome , crown dens syndrome , paraspinal abscess, or intra-abdominal mass . The diagnosis in these reports was made by MRI, which was occasionally combined with other modalities. (NEXT: Natural Way to Get Rid of Gout – Success Story)