Abstract
Pediatric osteoporosis is a rare but increasingly recognized entity that differs from adult forms in its etiology, diagnostic criteria, and long-term skeletal implications. Unlike age-related osteoporosis in adults, bone fragility in children is categorized into primary forms, such as osteogenesis imperfecta and the monogenic causes of early-onset osteoporosis, and the more prevalent secondary forms arising from chronic systemic disease, endocrine and nutritional disorders, malignancy and its treatment, prolonged medication use, and immobilization. Early and accurate diagnosis is critical, as failure to achieve optimal peak bone mass during growth can lead to lifelong morbidity. Imaging is central to this process, but interpreting pediatric bone health requires specialized knowledge: results are expressed as Z-scores rather than T-scores, they must be adjusted for body size, and they cannot be inferred from radiographs. While dual-energy X-ray absorptiometry (DXA) remains the reference standard in clinical practice, it measures areal rather than volumetric bone mineral density and is therefore confounded by bone size; quantitative CT and high-resolution peripheral QCT provide volumetric density and microarchitectural information. This review is centered on the practical questions faced by radiologists: how pediatric DXA should be performed, interpreted, and reported; which conditions mimic or overlap with osteoporosis in the diffusely under-mineralized pediatric skeleton; the spectrum of primary and secondary causes; and what radiologists should know about treatment monitoring and follow-up.