Ultra-low-dose CT detects synovitis in patients with suspected rheumatoid arthritis

Abstract

PurposeTo prove the feasibility and measure the diagnostic accuracy of contrast-enhanced ultra-low-dose CT (ULD-CT) for the depiction of inflammatory soft-tissue changes (synovitis, tenosynovitis and peritendonitis) in patients with arthritis of the hand.Materials and methodsIn this institutional review board–approved study, 36 consecutive patients over the age of 50 with suspected rheumatoid arthritis underwent ULD-CT (estimated radiation exposure <0.01 mSv) and MRI of the hand with weight-adapted intravenous contrast administration. ULD-CT subtraction and MR images were assessed for synovitis, tenosynovitis and peritendonitis by three readers using a modified Rheumatoid Arthritis MRI Score (RAMRIS). Patients were asked which modality they would prefer for future examinations. Sensitivity and specificity of ULD-CT for detection of inflammatory changes were calculated using MRI as standard of reference. The sum scores were correlated using Pearson’s r.ResultsAll 36 patients showed synovitis in MRI. ULD-CT had 69% sensitivity on the patient level and 65% on the joint level with 87% specificity. Sensitivity was higher in patients with more severe inflammation (80% for MRI RAMRIS >1). There was almost perfect correlation between the modified RAMRIS sum scores of ULD-CT and MRI (Pearson’s r=0.94). Regarding preferences for future examinations, 85% preferred ULD-CT over MRI. ULD-CT detected more differential diagnoses than MRI (8 vs 2/12).Conclusion Contrast-enhanced ULD-CT of the hand allows for depiction of soft-tissue inflammation at the hand and can be achieved using very low radiation exposure (<0.01 mSv). ULD-CT may evolve to a fast and comfortable alternative to MRI, although it is not as sensitive as MRI for detecting mild disease.

Ultra-low-dose computed tomography and its utility in wrist trauma in the emergency department

“…However, many studies used low dose for lower than standard or conventional CT dose (13,14). Furthermore, several studies used "ultra-low-dose" for lower than low-dose CT (10,15,16). In the present study, the dose results were the lowest in the literature.…”

Perfusion in hand arthritis on dynamic contrast-enhanced computed tomography: a randomized prospective study using MRI as a standard of reference

“…Additionally, CT is faster and more readily available. In our previous study, we showed that patients prefer CT than MRI and feel more comfortable in a CT scanner [ 13 ]. For comparability with MRI, CT examinations in our study were performed in the superman position as well.…”

“…Ultrasonography can be offered as an alternative imaging test [10], but the results are often dependent on the experience of the examiner and difficult to quantify [11]. The first studies investigated the capability of computed tomography (CT) in the detection of active inflammation [12,13]. Dynamic contrast-enhanced computed tomography (DCE-CT) has the potential to provide a differentiated estimation of inflammatory joint lesions through the assessment of perfusion parameters.…”

Fractal analysis of perfusion imaging in synovitis: a novel imaging biomarker for grading inflammatory activity based on assessing angiogenesis

“…Our study population constituted a convenience series and included patients, who were referred to the inpatient or outpatient clinic of rheumatology in our institution with suspected or known rheumatoid arthritis, the latter fulfilling the classification criteria of the American College of Rheumatology (ACR) 31. We analysed data from prospectively recruited patients during a previous study at our institution from September 2016 to October 2017 5 32. Diagnosis was established by board-certified rheumatologists by clinical findings (history, swollen and tender joints), laboratory findings (C reactive protein, rheumatoid factors, anticitrullinated protein antibodies) and imaging findings.…”

“…No exclusion criteria applied other than age >50 years (due to a requirement of our local ethics committee) and absent contraindications to the MRI procedure. Patients were involved by systematically surveying their concerns and comfort with the MRI examination as previously detailed 5 32…”