Feasibility study of semi-automated measurements of finger joint space widths

Abstract

The purpose of this study is to evaluate technical feasibility based on image capturing conditions (film-focus distance (FFD), film sensitivity, film brand, exposure level and tube voltage) that potentially alter radiographs and consequently may influence the semi-automated measurement of joint space distance (JSD) by computer-aided joint space analysis (CAJSA) in rheumatoid arthritis and osteoarthritis. The radiographs of a left hand (deceased man) were acquired under systematically changing image capturing conditions (exposure level: 4-8 mAs; FFD: 90-130 cm; film sensitivity: 200/400 and tube voltage: 40-52 kV with different image modalities: conventional radiographs, original digital radiographs, digital print-outs). All JSD-measurements were performed with the CAJSA-technology (Radiogrammetry Kit, Version 1.3.6; Sectra; Sweden) at the metacarpal-phalangeal articulation. JSD-analysis was not influenced by changes of FFD, exposure level, film sensitivity or film brand. JSD showed significant variation caused by tube voltage (conventional: CV = 1.913% for Agfa and CV = 2.448% for Kodak; digital: CV = 0.741% for Philips print-outs and CV = 0.620% with original digital images versus CV = 2.185% for Siemens print-outs and 0.951% with original digital images). Computer-aided joint space analysis for JSD-measurements is unaffected by the following image capturing parameters: film-focus distance, film sensitivity, film brand and exposure level. An influence of tube voltage was detected in a lesser extent for original digital images compared to the printed digital as well as conventional versions. Consequently, a standardized tube voltage is essential for accurate reproductions of CAJSA-measurements in rheumatoid arthritis and osteoarthritis.

Joint damage in rheumatoid arthritis: assessment of a new scoring method

“…A previous study showed that technical parameters, such as exposure level, film brand, film sensitivity, and film focus distance, do not affect the reproducibility of CAJSA measurements during the image-acquisition process [13]. Recently published data presented no influence of hand rotation on CAJSA measurements with the exception of a hand rotation of more than 15° during X-ray imaging, which is complementary to an oblique acquired hand radiograph and should be not used for CAJSA measurements [11].…”

Radiographic remission in rheumatoid arthritis quantified by computer-aided joint space analysis (CASJA): a post hoc analysis of the RAPID 1 trial

“…As a potential limitation of our study, the influence of X-ray imaging parameters as well as joint gap width detection should be discussed. In this context, an experimental study revealed no significant influence of the image acquisition protocol on measurement JSD [29]. Additionally, the CAJSA-system checked the image quality and stopped the measurements if the image quality was poor and if there was a misalignment of the joints.…”

Computer-Based Radiographic Quantification of Joint Space Narrowing Progression Using Sequential Hand Radiographs: Validation Study in Rheumatoid Arthritis Patients from Multiple Institutions

“…Until now, many of the presented methods have been tested on datasets from one institute, in which hand radiographs were acquired via the same radiographic protocol [7,28]. Pfeil et al reported that computer-aided analysis for joint space measurements is affected by alternation of tube voltage to a lesser extent [29]. Therefore, we used datasets from two institutions with different digital image acquisition systems to demonstrate that our computer-based method can allow shared use by several users in different locations.…”