The Daily Resistive Index measurement useful tool in the estimation of the optimal time interval between two Shock Wave Lithotripsy sessions

Nephrolithiasis in ankylosing spondylitis and its relationship with disease assessment scales

OBJECTIVE:

The aim of this study was to investigate the frequency of renal calculi in patients with ankylosing spondylitis (AS) and to determine its relationship with disease assessment variables.

METHODS:

The study was designed retrospectively, and it included a cohort of 320 patients with AS diagnosed using the Modified New York Criteria. A total of 119 patients who underwent renal ultrasonography (USG), in who the erythrocyte sedimentation rate, C-reactive protein, blood calcium, phosphorus, Vitamin D, parathormone, and urinary calcium excretion were measured, and who also had lateral cervical and lumbar radiography in the same time period were extracted from the cohort. All patients’ demographic characteristics and the results of blood and urine tests were recorded. The Ankylosing Spondylitis Disease Activity Index (BASDAI), Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Mobility Index (BASMI), and Modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) were evaluated in all patients.

RESULTS:

Thirteen of the 119 patients had renal calculi confirmed by USG data. The frequency of nephrolithiasis detected by USG was 10.9% in patients with AS. The disease lasted significantly longer in patients with renal calculi ([nephrolithiasis (+): 18.39±8.72 years; nephrolithiasis (−): 12.02±8.43 years, p=0.01]). The BASMI total score was significantly higher in the group of patients with renal calculi. There was not any significant difference in terms of blood samples, HLA-B27, BASDAI, BASFI, and mSASSS between groups.

CONCLUSION:

The frequency of renal stones is increased in patients with AS compared to healthy population. Especially patients who had AS for a long time and higher BASMI values are more susceptible to renal calculi. It is important to point out that the results of this type of studies would be more reliable if the study is conducted on large patient groups and population-based prevalence.

Role of Diffusion-weighted and Contrast-enhanced Magnetic Resonance Imaging in Differentiating Activity of Ankylosing Spondylitis

Background:

Previous studies showed that combining apparent diffusion coefficient (ADC) value with the Spondyloarthritis Research Consortium of Canada (SPARCC) index value might provide a reliable evaluation of the activity of ankylosing spondylitis (AS), and that contrast-enhanced (CE) magnetic resonance imaging (MRI) is unnecessary. However, the results were based on confirming only a small random sample. This study aimed to assess the role of CE-MRI in differentiating the disease activity of AS by comparing ADC value with a large sample.

Methods:

A total of 115 patients with AS were enrolled in accordance with Bath AS Disease Activity Index and laboratory indices, and 115 patients were divided into two groups, including active group (n = 69) and inactive group (n = 46). SPARCC, ΔSI, and ADC values were obtained from the short tau inversion recovery (STIR), diffusion-weighted imaging (DWI), and CE-MRI, respectively. One-way analysis of variance and receiver operating characteristic analysis were performed for all parameters.

Results:

The optimal cutoff values (with sensitivity, specificity, respective area under the curve, positive likelihood ratio, and negative likelihood ratio) for the differentiation between active and inactive groups are as follows: SPARCC = 6 (72.06%, 82.61%, 0.836, 4.14, 0.34); ΔSI (%) = 153 (80.6%, 84.78%, 0.819, 5.3, 0.23); ADC value = 1.15 × 10⁻³ mm²/s (72.73%, 81.82%, 0.786, 4, 0.33). No statistical differences were found among the predictive values of SPARCC, ΔSI, and ADC. Multivariate analysis showed no significant difference between the combination of SPARCC and ADC values with and without ΔSI.

Conclusions:

Using large sample, we concluded that the combination of STIR and DWI would play significant roles in assessing the disease activity, and CE-MRI sequence is not routinely used in imaging of AS to avoid renal fibrosis and aggravation of kidney disease.