COMPARATIVE STUDY OF DUAL ENERGY X-RAY ABSORPTIOMETRY SCAN AND CONVENTIONAL RADIOGRAPHY IN EARLY DETECTION OF RENAL OSTEODYSTROPHY

Abstract

Archana Singh1, Mithun Chaudhuri2, Rajendra Pandey3, Pradip Kumar Deb4

BACKGROUND
Renal osteodystrophy is a part of broad spectrum of disturbances in mineral and bone metabolism, which are prevalent in Chronic Kidney Disease (CKD) and lead to serious and debilitating complications unless these abnormalities are addressed and treated at an early stage. Therefore, by this study, we try to compare Dual X-ray Absorptiometry (DXA) scan and conventional radiography in their ability to detect such lesions early and characterise them.
MATERIALS AND METHODS
Our study was a comparative study conducted over a period of one year. The subjects in our study were the newly diagnosed CKD patients of stage III, stage IV and stage V without any renal replacement therapy (renal transplant/dialysis) or any recent or intercurrent illness. 52 such patients were selected and they were evaluated by doing conventional radiographs and DXA scan of specific sites (lumbosacral spine, pelvis including femur and hands including radius).
RESULTS
At the lumbosacral spine, DXA revealed reduced bone density in 50% of which 40% had osteopenia and 10% had osteoporosis. At the pelvis, DXA was positive in 52% cases at femur of which 42% had osteopenia and 10% had osteoporosis. At forearm in the radius, DXA was positive in 62% cases of which 45% had osteopenia and 17% had osteoporosis. Conventional radiography revealed abnormality in 21% of the subjects at LS spine, 19% in pelvis and 26.9% in hands.
CONCLUSIONS
1. DXA studies of the radius are most appropriate for evaluation of bone mineral density in predialysis CKD patients.
2. In conventional radiography studies, the most sensitive site for radiographic abnormality is hand in predialysis CKD patients. Reduced bone density is the most common abnormal finding on conventional radiographs.
3. Though DXA has overall higher sensitivity than conventional radiography in identifying reduced bone mineral density in CKD, the specific features of renal osteodystrophy is better done by conventional radiography.

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