Indian Journal of Rheumatology

LETTER TO EDITOR
Year
: 2017  |  Volume : 12  |  Issue : 2  |  Page : 120-

Comment on “Ultrasonographic evaluation of joint involvement in rheumatoid arthritis: Comparison with conventional radiography and correlation with disease activity parameters”


Iftikhar Ahmad 
 Center for Nuclear Medicine and Radiotherapy (CENAR), Quetta, Pakistan

Correspondence Address:
Iftikhar Ahmad
Center for Nuclear Medicine and Radiotherapy (CENAR), Quetta
Pakistan




How to cite this article:
Ahmad I. Comment on “Ultrasonographic evaluation of joint involvement in rheumatoid arthritis: Comparison with conventional radiography and correlation with disease activity parameters”.Indian J Rheumatol 2017;12:120-120


How to cite this URL:
Ahmad I. Comment on “Ultrasonographic evaluation of joint involvement in rheumatoid arthritis: Comparison with conventional radiography and correlation with disease activity parameters”. Indian J Rheumatol [serial online] 2017 [cited 2020 Oct 30 ];12:120-120
Available from: https://www.indianjrheumatol.com/text.asp?2017/12/2/120/206095


Full Text



Dear Editor,

Recently, I read the article by Saigal et al. with great interest.[1] The authors have done valuable work in assessing joint involvement in rheumatoid arthritis (RA) based on power Doppler ultrasound (PDUS) and its comparison with conventional radiography (CR). Specifically, cumulative flow signal - an indicator of inflammation in RA patients - was shown to vary significantly (P < 0.01) among patients in remission and having low, moderate, and high disease activity. It was concluded that PDUS detects erosions of bone more sensitively than CR.[1] Although PDUS provides advantage over CR in evaluating RA, the overall comparison of magnetic resonance imaging (MRI) and PDUS needs more emphases for the common readers, which I would like to elaborate.

Both PDUS and MRI have been used as surrogate tools for assessment of structural damage and disease activity in RA. PDUS has emerged as a promising tool for RA assessment due to its noninvasive nature, better sensitivity, high resolution, and cost effectiveness. PDUS can sensitively detect fluid in joints, bursae and tendon sheaths and evaluated tendons and ligaments.[2] However, PDUS is less validated in clinical settings, perhaps due to the lack of standardized practice, inability for bone marrow edema detection, operator subjectiveness, extreme sensitivity to tissue movement, feasibility issues (i.e., optimum number of joints to scan for RA diagnosis/monitoring, treatment/remission assessment), poor repeatability, difficulty in visualizing deeper structures, etc.[3],[4]

Alternatively, MRI offers superior sensitivity for the detection of inflammation and bone erosion. Specifically, assuming T1-weighed MRI as the reference standard, PDUS had a sensitivity and specificity of 0.70 and 0.78 for inflammation detection in the small joints of the hands, respectively.[5] MRI also permits detail global assessment of all the structures (e.g., synovial membrane, fluid collections, cartilage, ligaments, bone, tendons and tendon sheaths) involved in RA. MRI is also capable to assess the joint space narrowing, as opposed to PDUS.[2],[3],[4] However, the MRI-associated setbacks include motion artifact, prolonged examination time, relatively low resolution and clinical availability.

Collectively, MRI appears a superior tool for assessment of RA; nevertheless, PDUS has also shown clinical promise. Both PDUS and MRI at times can provide complementary information.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Saigal R, Goyal L, Maharia H, Sharma M, Agrawal A. Ultrasonographic evaluation of joint involvement in rheumatoid arthritis: Comparison with conventional radiography and correlation with disease activity parameters. Indian J Rheumatol 2017;12:6-11.
2Bhasin S, Cheung PP. The role of power Doppler ultrasonography as disease activity marker in rheumatoid arthritis. Dis Markers 2015;2015:325909.
3Ostergaard M, Szkudlarek M. Imaging in rheumatoid arthritis – Why MRI and ultrasonography can no longer be ignored. Scand J Rheumatol 2003;32:63-73.
4Baillet A, Gaujoux-Viala C, Mouterde G, Pham T, Tebib J, Saraux A, et al. Comparison of the efficacy of sonography, magnetic resonance imaging and conventional radiography for the detection of bone erosions in rheumatoid arthritis patients: A systematic review and meta-analysis. Rheumatology (Oxford) 2011;50:1137-47.
5Szkudlarek M, Klarlund M, Narvestad E, Court-Payen M, Strandberg C, Jensen KE, et al. Ultrasonography of the metacarpophalangeal and proximal interphalangeal joints in rheumatoid arthritis: A comparison with magnetic resonance imaging, conventional radiography and clinical examination. Arthritis Res Ther 2006;8:R52.