The evaluation of sacroiliitis using 99mTc-nanocolloid and 99mTc-MDP scintigraphy

Abstract

The role of imaging studies in the evaluation of patients with sacroiliitis is controversial. We aimed to evaluate the role of nanocolloid and bone scintigraphy in patients with sacroiliitis and to investigate the clinical relevance of imaging findings. Thirty-two patients with clinically sacroiliac disease (nine females, 23 males, aged 22-47 years) underwent scintigraphic and radiographic examinations and all imaging studies were performed within 2 weeks. Twenty-five subjects were also included as a control group (10 females, 15 males, aged 20-51 years) for quantitative analysis of the bone scan. The quantitative analysis was done by using regions of interest drawn over the right and left sacroiliac (SI) joint and sacrum (S) and SI/S ratios were calculated. Abnormal uptake was defined as an uptake higher than the mean +/- 2 SD of the control SI/S values. Bone scintigraphy was performed using a three-phase technique and single photon emission computed tomography (SPECT). Nanocolloid scintigraphy (NS) was performed 1 h later, after administration of 370 MBq 99mTc-nanocolloid, and evaluated visually. Each of the scintigraphic examinations was performed on separate days within the same week. Sensitivity values were 25%, 47%, 69% and 97%, and specificity values were 80%, 90%, 95% and 90% in quantitative bone scanning (QBS), 99mTc-NS, planar and SPECT bone imaging, respectively, when the clinical findings were considered as the 'gold standard'. Our results showed that bone SPECT scanning was more sensitive than planar imaging, but planar imaging was the most specific method. SPECT was also the most associated technique with clinical findings. 99mTc-NS was neither specific nor sensitive enough in the detection of sacroiliitis although it could be helpful for the confirmation of inflammation.

Limited Diagnostic Value of Unilateral Sacroiliitis in Scintigraphy in Assessing Axial Spondyloarthritis

“…Our findings are in concordance with the few scintigraphy studies that have so far reported on unilateral sacroiliitis (6, including 104 patients with axial SpA and 36 controls) [7][8][9][10][11][12] . Sensitivities of unilateral sacroiliitis in these studies were low, ranging from 6.3% 10 to 33.3% 12 , while specificities were high, ranging between 89.5% 8 and 94.1% 7 , resulting in a pooled LR of 2.1.…”

The diagnostic value of scintigraphy in assessing sacroiliitis in ankylosing spondylitis: a systematic literature research

“…Sensitivity could be further calculated for those patients with AS with x -ray grade 2 or 3 findings (excluding grade 4) for 244 patients with AS from 11 studies23 28 35 – 37 39 – 41 46 – 48), 160 of these had positive findings by scintigraphy resulting in a sensitivity of 65.57%.…”

“…Sensitivity could also be calculated for 71 patients with AS with x -ray grade 4 findings (complete ankylosis of the SIJs) from 10 studies23 24 28 36 37 39 – 41 47 48). Only five of these 71 patients with AS had positive findings by scintigraphy, which translates into a sensitivity of 7.04%.…”

Imaging in rheumatology: reconciling radiology and rheumatology

“…5). It has been suggested that bone scintigraphy be combined with bone marrow scintigraphy but doubts regarding the usefulness of this technique remain [56]. …”