Imaging in non-bacterial osteomyelitis in children and adolescents: diagnosis, differential diagnosis and follow-up—an educational review based on a literature survey and own clinical experiences

Abstract

Background Chronic non-bacterial osteomyelitis (CNO) is an autoinflammatory bone disorder affecting children and adolescents. Previously classified as a rare disease, recent studies suggest a higher incidence of the disease. CNO may develop into the clinical presentation of chronic recurrent osteomyelitis (CRMO) with high relapse rate and multifocality. Main body Diagnosis of CNO/CRMO is often delayed, with implications for disease severity and relapse rate. This can be significantly improved by knowledge of the disease entity and its characteristics. Imaging plays a key role in diagnosis, differential diagnosis and therapy monitoring. Magnetic resonance imaging (MRI) has several advantages compared to other imaging methods and is increasingly applied in clinical studies. Recent studies show that a whole-body (WB) coverage (WB-MRI) without contrast agent administration is a rational approach. This educational review is based on a systematic analysis of international peer-reviewed articles and presents our own clinical experiences. It provides an overview of disease entity, incidence and clinical diagnosis. The role of imaging, especially of whole-body MRI, is discussed in detail. Finally, practical advice for imaging, including flowcharts explaining when and how to apply imaging, is provided. Conclusion Knowing the specifics of CNO/CRMO and the importance of MRI/whole-body MRI allows rapid and efficient diagnosis as well as therapy support and helps to avoid irreversible secondary damage.

Whole-body magnetic resonance imaging findings and patterns of chronic nonbacterial osteomyelitis in a series of Greek pediatric patients

“…8,13 Most recently, whole-body magnetic resonance imaging (WBMRI) has emerged as the imaging modality of choice, often obviating bone biopsy providing scanning of the whole skeleton within an acceptable examination time and revealing multiple bone lesions [14][15][16][17] many of them being asymptomatic. 5,18 During our clinical practice, we noticed some variations in WBMR imaging patterns of our patients with CNO, all of them being of Greek origin, compared with previous studies, such as paucity of spinal lesions except for the sacrum and involvement of the bones of ankles and feet in even higher frequency than previously described. In this retrospective study, we attempted to evaluate the imaging findings and patterns of CNO on WBMRI in a series of Greek pediatric patients.…”

“…[1][2][3] The term autoinflammatory bone disease includes a spectrum of spontaneous activation of the immune system, leading to non-specific inflammatory processes in bones. This disorder is gaining medical momentum in recent years [3][4][5] and is considered the clinical and pathophysiologic counterpart of SA-PHO syndrome in adults, 6 while associated with seronegative arthritides. [7][8][9] CNO can affect almost any bone type, most commonly tibial and femoral metaphyses, followed by pelvic bones, spine, and clavicle, 8,[10][11][12][13] and is characterized by spontaneous remissions and exacerbations.…”

“…8,13 Most recently, whole-body magnetic resonance imaging (WBMRI) has emerged as the imaging modality of choice, often obviating bone biopsy providing scanning of the whole skeleton within an acceptable examination time and revealing multiple bone lesions 14–17 many of them being asymptomatic. 5,18…”

Defining the imaging diagnostic criteria for adult chronic non-bacterial osteitis

“…MRI is also inferior compared to CT in accurately evaluating some of the characteristic structural morphological changes of CNO such as sclerosis (particularly when subtle), hyperostosis, ligamentous calcifications, erosions and ankylosis in the ACW, which are key to establishing the diagnosis. 23 , 45-47 …”

A Successful Bisphosphonates Monotherapy in Spinal Form of Paediatric Chronic Recurrent Multifocal Osteomyelitis (CRMO)—Case Report

“…Though this disorder is considered rare, its actual prevalence might be higher than reported. It is thought to be underdiagnosed due to false identification as one of the numerous differential diagnoses of CRMO [ 19 , 20 ]. Though the genetic background of CRMO has not yet been precisely elucidated [ 21 ], the results of recent genetic studies showed significant differences in gene expression between patients with CRMO and otherwise healthy study participants [ 22 ].…”