Comparative Study of Imaging of Sacroiliitis by CT and MRI-Scan with Power Doppler Ultrasound in Spondyloarthritis

INTRODUCTION Spondyloarthritides are the group of inflammatory disorders of unknown cause and these are often associated with human leukocyte antigen (HLA) -B27. In all these cases, the presence of sacroiliitis is considered as the hallmark of AxSpA and ankylosing spondylitis, but it take longer time to appreciate the radiological features of either sacroiliac or spinal inflammation. As everyone aware, early diagnosis and prompt initiation of non- biological or biological DMARD can arrest or prevent or delay the expected non remediable complications of SpA/AS. Mostly, clinicians are dependent on either MRI or CT scan for the diagnosis of spondyloarthritis, but it has its own merits and demerits. Thus, in our study, we have used low cost, everywhere and easily available power doppler ultrasound in early diagnosis of spondyloarthritis and systematically compared with MRI and CT- pelvis with an age matched healthy controls. AIM OF THE STUDY To diagnose Spondyloarthritis before radiological erosions. To compare Power Doppler imaging of sacroiliitis with conventional CT and MRI scan of Pelvis. OBJECTIVES OF THE STUDY Across the world, SpA/ AS is a significant burdens to young, reproductive and the potential earning population. If undiagnosed or inadequately treated, it not only causes continuous pain, stiffness and fatigue and it can lead to erosions, narrowing of joint space and complete ankylosis of spine and pelvic joints with resultant loss of nobilities and functions. To accept the truth that, approximately from the onset of symptoms to diagnosis of SpA/ AS is about 8 to 11 years. Added to that, SI joint is not easily palpated or manipulated and investigations like X-Rays, MRI, CAT Scans, Bone Scans are reported as normal if the observers are not having adequate knowledge in where and what to look for. Thus, miserably, patients may miss early diagnosis and appropriate initiation of treatment for SpA. Conventional x-ray pelvis are not suitable for picking up early synovial inflammation and erosions, hence we depends on the MRI and CT-SCAN, which are not easily available to everyone and expensive and risk of ionizing radiations, respectively. For a decade, power colour Doppler ultrasound is considered as extended hand of Rheumatologists and declared as the poor mans MRI and it remarkably help us in early diagnosis of synovitis, enthesitis, tenosynovitis, synovial effusions and proliferation, erosions of cartilage, bone joint margin, enchondral bone erosion, cyst, osteopenia and in crystal deposition diseases. MATERIALS AND METHODS In this prospective case control study from January 2007 to February 2009, one hundred and eight patients (84 males, 24 females) were included from those who have presented with signs and symptoms and clinical features suggestive of spondyloarthritis to the Department of Rheumatology, Madras Medical College and Rajiv Gandhi Government General Hospital, Chennai.3. Thirty five age and sex matched asymptomatic controls were selected from patients attenders who were not a first or second degree relatives. All patients were asked for a detailed history which includes the age of onset of disease, symptoms of disease, duration of the disease and relevant symptoms of secondary AS. A detailed general examination, height and weight assessment was done and usual laboratory tests and all disease activity index scores were calculated. RESULTS One hundred and eight patients were recruited in this study. Among these, 84 were males and 24 were females (3.51). The mean age of patients was 30 11.10 years (range from 16 to 59 years). The average disease duration was 3.46 5.23 years (range from one month to 23 years). There were 35 age and sex matched controls (27 males, 8 females, mean age 30 11). CONCLUSION Both MRI and power Doppler ultrasound are 100 % sensitive in identifying sacroiliitis. CT-scan is a useful modality of imaging in sacroiliitis but it is not suitable for identifying the early synovial inflammation and erosions and it also has the risk of ionizing radiation. The poor man MRI, the Power Doppler ultrasound becomes the potent choice of tool for the early diagnosis of spondyloarthritis.