Can Dual‐Energy Computed Tomography Be Used to Identify Early Calcium Crystal Deposition in the Knees of Patients With Calcium Pyrophosphate Deposition?

Abstract

Objective. To assess the ability of dual-energy computed tomography (DECT) in identifying early calcium crystal deposition in menisci and articular cartilage of the knee, depending on the presence/absence of chondrocalcinosis seen on conventional CT. Methods. One hundred thirty-two knee DECT scans from patients with suspected crystal-associated arthropathy were reviewed and assigned to a calcium pyrophosphate deposition (CPPD) group (n = 50) or a control group (n = 82). Five DECT attenuation parameters were measured in preset regions of interest (ROIs) in menisci and articular cartilage and compared between groups using linear mixed models with adjustment for confounders. Subgroup analysis, excluding ROIs with chondrocalcinosis seen on conventional CT, was performed. Results. In both menisci and articular cartilage, and for all 5 DECT attenuation parameters, calcified ROIs in CPPD patients showed significantly higher values than ROIs in controls (P ≤ 0.036). Conversely, noncalcified ROIs in CPPD patients were comparable with those in controls (P ≥ 0.09). While specific DECT parameters yielded good accuracy (area under the curve [AUC] 0.87-0.88) in differentiating calcified ROIs in CPPD patients from ROIs in controls, DECT failed to distinguish between noncalcified ROIs in CPPD patients and controls (AUC 0.58-0.59). Conclusion. While DECT has the potential to characterize knee intraarticular mineralization, this technique cannot yet accurately identify early calcium crystal deposition that is not visible as chondrocalcinosis on conventional CT.

The role of dual energy computed tomography in the differentiation of acute gout flares and acute calcium pyrophosphate crystal arthritis

“…Current reconstruction protocols only allow colour coding of one variable, perhaps future protocols will allow coding for two variables with independent settings. All CPP crystal arthritis patients who demonstrated CPP typical depositions on radiographs also displayed CPP positive findings on DECT, in line with a previous study by Budzik et al, which also showed that DECT was not able to reliably identify CPP deposits in patients unless chondrocalcinosis was already visible on conventional X-rays [34]. Ultrasound sensitivity and specificity were 92% and 83% respectively for gout.…”

High prevalence of chondrocalcinosis and frequent comorbidity with calcium pyrophosphate deposition disease in patients with seronegative rheumatoid arthritis

“…Furthermore, one can ask whether we have used the best imaging method to detect crystals, since promising studies about the use of ultrasound37 in the identification of CPPD have been published while the significance of DECT seems less clear 38 39. In this study we have not systematically used ultrasound to detect crystals in hand or feet due to lack of standardisation.…”

Accuracy of synovial fluid analysis compared to histology for the identification of calcium pyrophosphate crystals: an ancillary study of the OMERACT US Working Group - CPPD subgroup

“…ability and criterion validity with good results (13,18,19); while DECT has proven helpful in the diagnosis of gout, and emerging data suggest that it may be promising in calcium crystal recognition and differentiation as well (20,21). Nonetheless, SFA via compensated polarized light microscopy is still considered the gold standard for the identification and diagnosis of CPPD-related arthropathies (1).…”