Whole body MR imaging in ankylosing spondylitis: a descriptive pilot study in patients with suspected early and active confirmed ankylosing spondylitis

BACKGROUND: Ankylosing spondylitis is a chronic inflammatory rheumatic disorder which usually begins in early adulthood. The diagnosis is often delayed by many years. MR imaging has become the preferred imaging method for detection of early inflammation of the axial skeleton in ankylosing spondylitis. The goal of this study was to assess the frequency and distribution of abnormalities on whole body MR imaging in patients with suspected early ankylosing spondylitis and with active confirmed ankylosing spondylitis. METHODS: Ten patients with suspected early ankylosing spondylitis and ten patients with confirmed ankylosing spondylitis were enrolled. On an 18-channel MR system, coronal and sagittal T1 weighted and STIR sequences were acquired covering the entire spine, sacrum, anterior chest wall, shoulder girdle, and pelvis. The total examination time was 30 minutes. RESULTS: In both groups inflammatory lesions of the lower thoracic spine were frequent (number of patients with suspected early/confirmed ankylosing spondylitis: 7/9). In confirmed ankylosing spondylitis the upper thoracic spine (3/6) and the lumbar spine (4/8) were more commonly involved. The inferior iliac quadrant of the sacroiliac joints was frequently altered in both groups (8/8). The superior iliac (2/5), inferior sacral (6/10) and superior sacral (3/6) quadrants were more frequently affected in confirmed ankylosing spondylitis. Abnormalities of the manubriosternal joint (2/4), the sternoclavicular joints (1/2) and hip joint effusion (4/3) were also seen. CONCLUSION: In both suspected early ankylosing spondylitis and confirmed ankylosing spondylitis, whole body MR examinations frequently demonstrate inflammatory lesions outside the sacroiliac joints. These lesions are similarly distributed but occur less frequently in suspected early compared to confirmed ankylosing spondylitis. Due to the small sample size in this pilot study these results need to be confirmed in larger studies with this emerging technique

MR imaging of therapy-induced changes of bone marrow

MR imaging of bone marrow infiltration by hematologic malignancies provides non-invasive assays of bone marrow cellularity and vascularity to supplement the information provided by bone marrow biopsies. This article will review the MR imaging findings of bone marrow infiltration by hematologic malignancies with special focus on treatment effects. MR imaging findings of the bone marrow after radiation therapy and chemotherapy will be described. In addition, changes in bone marrow microcirculation and metabolism after anti-angiogenesis treatment will be reviewed. Finally, new specific imaging techniques for the depiction of regulatory events that control blood vessel growth and cell proliferation will be discussed. Future developments are directed to yield comprehensive information about bone marrow structure, function and microenvironment

Quantitative analyses of sacroiliac biopsies in spondyloarthropathies: T cells and macrophages predominate in early and active sacroiliitis— cellularity correlates with the degree of enhancement detected by magnetic resonance imaging

OBJECTIVE—Sacroiliitis is a hallmark of the spondyloarthropathies (SpA). The degree of inflammation can be quantified by magnetic resonance imaging (MRI). The aim of this study was to further elucidate the pathogenesis of SpA by quantitative cellular analysis of immunostained sacroiliac biopsy specimens and to compare these findings with the degree of enhancement in the sacroiliac joints (SJ) as detected by dynamic MRI.
METHODS—The degree of acute sacroiliitis detected by MRI after intravenous administration of gadolinium-DTPA was quantitatively assessed by calculating the enhancement observed in the SJ and chronic changes were graded as described in 32 patients with ankylosing spondylitis (n=18), undifferentiated SpA (n=12) and psoriatic arthritis (n=2). Back pain was graded on a visual analogue scale (VAS, 0-10) and disease duration (DD) was assessed. Shortly after MRI, SJ of patients with VAS > 5 were biopsied guided by computed tomography. Immunohistological examination was performed using the APAAP technique; only whole sections > 3 mm were counted.
RESULTS—By MRI, chronic changes ⩽ grade II were detected in nine patients (group I, DD 2.5 (SD 2.9) years) and > II in 13 patients (group II, DD 7.3 (SD 4.8) years), while enhancement < 70% was found in eight (group A, DD 5.6 (SD 3.3) years) and > 70% in 12( )patients (group B, DD 4.7 (SD 5.8) years). The relative percentage of cartilage (78-93%), bone (7-18%) and proliferating connective tissue (1-4%) was comparable between the groups (range). There were more inflammatory cells in group I compared with group II (mean (SD) 26.7(20.1) versus 5.3 (5.2), p=0.04) and group A compared with B (21.8 (17.3) versus 6.0 (5.6), p=0.05) cells/10 mm(2)), T cells (10.9 (8.5)) being slightly more frequent than macrophages (9.6 (16.8/10 mm(2))). Clusters of proliferating fibroblasts were seen in three and new vessel formation in seven cases.
CONCLUSION—This study shows that T cells and macrophages are the most frequent cells in early and active sacroiliitis in SpA. The correlation of cellularity and MRI enhancement provides further evidence for the role of dynamic MRI to detect early sacroiliitis.


Six-week treatment of axial spondyloarthritis patients with an optimal dose of nonsteroidal antiinflammatory drugs : early response to treatment in signal intensity on magnetic resonance imaging of the sacroiliac joints

Objective. To evaluate the early effect of full-dose nonsteroidal antiinflammatory drugs (NSAIDs) on the extent and intensity of bone marrow edema of the sacroiliac (SI) joints on magnetic resonance imaging (MRI) in axial spondyloarthritis (SpA). Methods. A single-center, 6-week study of a cohort of consecutive patients with clinically suspected axial SpA was conducted. A total of 117 patients were screened. Forty patients who were diagnosed as having axial SpA and had presented with a positive MRI of the SI joints as defined by the Assessment of SpondyloArthritis international Society (ASAS) criteria were considered for a followup MRI after 6 weeks of an optimal dose of NSAIDs. Twenty patients completed the study. Disease activity was monitored by determining the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score every 2 weeks and the Bath Ankylosing Spondylitis Functional Index score at baseline and week 6. NSAID intake was assessed by the ASAS NSAID index. Primary end points were improvement in bone marrow edema of the SI joints on MRI and BASDAI response at week 6. Results. Approximately one-third of eligible patients newly diagnosed as having axial SpA were unable to continue the full-dose NSAID schedule. The median NSAID index was 97% in patients who completed the study. There was a reduction of 1.1 units (10.5%) in mean Spondyloarthritis Research Consortium of Canada (SPARCC) scores at week 6 in comparison to baseline (P=0.032). Overall, only 30% of the patients (6 of 20) had a minimal clinically important difference of 2.5 in SPARCC score. However, 80% of the patients displayed high-intensity lesions on STIR images at baseline, which decreased significantly at week 6 (P=0.011). There was a significant decrease in the relative intensity of the region of interest (P=0.007) and a mean decrease of 0.6 in the BASDAI score per 2 weeks of therapy (P=0.001). Only 29.4% of the patients met the BASDAI criteria for 50% improvement (BASDAI50) at week 6. Conclusion. Our findings indicate a high level of dropout among patients receiving full-dose NSAID therapy in daily practice. In those who tolerated NSAID therapy, there was no clinically relevant decrease in SPARCC scores and low BASDAI50 response. However, we found a decrease in signal intensity of bone marrow edema of the SI joints as an early response to 6 weeks of optimal NSAID therapy in patients newly presenting with axial SpA