Screen-film versus digital radiography of sacroiliac joints: evaluation of image quality and dose to patients.

The purpose of this paper is to evaluate the image quality and dose to patients in the radiography of sacroiliac joints and to perform a clinical comparative study of digital and conventional screen-film radiography. Routine radiography of sacroiliac joint was performed in 60 patients using digital and screen-film radiography. The visibility of five anatomical regions and the overall image quality were rated by experienced radiologists. Patient dose assessment in terms of entrance surface air kerma (ESAK) was performed. The digital system showed slightly improved visualisation of specific anatomical structures. Overall image quality was significantly better in the digital when compared with the screen-film imaging system. The average ESAK was 2.4 mGy in screen-film and 3.6 mGy in digital radiography. The digital radiography provided equal or better visibility of anatomical details and overall image quality, but on higher dose levels. Therefore, the practice on digital systems must be optimised.

Construct validity and reliability of ultrasound disease activity score in assessing joint inflammation in RA: comparison with DAS-28.

OBJECTIVE: To investigate the construct validity and reliability of US DAS compared with 28-joint DAS (DAS-28) in assessing joint inflammation and in prediction of structural damage in patients with RA. METHODS: Ninety patients with active RA were prospectively recruited and followed up during the 6 months of treatment. The patients underwent clinical, laboratory and X-ray assessment, along with blinded power Doppler US (PDUS) and grey-scale (GS) US (GSUS) examination at baseline and 6 months. A subgroup of 25/90 randomly assigned patients underwent MRI examination of their hands at baseline. A PDUS examination of 22 joints and GSUS examination for effusion/hypertrophy (E/H) of 28 joints were performed by two independent examiners, blinded to clinical findings. E/H was qualitatively assessed as absent or present, and PD signal was semi-quantitatively graded from 0 to 3. PDUS score for synovitis in 22 joints and GS score for E/H in 28 joints were included in US DAS calculation. Clinical scoring, PDUS and GSUS inter-observer reliability were evaluated. RESULTS: Strong correlation was found between US DAS and standard assessment of disease activity such as the DAS-28, ESR and CRP levels. Correlation between US DAS and patients' and physicians' visual analogue scale of activity was moderate, whereas correlations of US DAS with Health Assessment Questionnaire - Disability Index (HAQ-DI) and Short Form 36 Health Survey (SF-36) were weak to moderate. US DAS correlated with X-ray, MRI and US parameters and rates of joint damage. CONCLUSION: US DAS better anticipated future joint damage than standard DAS-28.