Whole-body MRI in the diagnosis of paediatric CNO/CRMO

Diagnostic Role of FDG PET/CT in Pediatric Patients With Chronic Recurrent Multifocal Osteomyelitis

PURPOSE

Chronic recurrent multifocal osteomyelitis (CRMO), or chronic nonbacterial osteomyelitis, is difficult to diagnose. The accurate diagnosis of CRMO relies on comprehensive imaging examinations because of its multifocal nature. In this regard, 18 F-FDG PET/CT has demonstrated significant utility in inflammatory diseases. This study tries to determine the value of FDG PET/CT in the evaluation of CRMO.

PATIENTS AND METHODS

We retrospectively collected imaging data from pediatric CRMO patients who underwent FDG PET/CT scans. Lesions exhibiting abnormal metabolism with/without structural abnormalities on FDG PET/CT were identified as CRMO lesions, and their location and SUV max were recorded.

RESULTS

A total of 21 pediatric patients with CRMO were included in this study. The median age at diagnosis was 9.4 years. Total 131 foci of abnormal activity were identified using FDG PET/CT imaging. The distribution pattern showed a higher prevalence of lower limbs and pelvis involvement. Among all identified lesions, abnormalities were detected on both PET and CT images of 93 lesions, whereas exclusively positive findings on 18 F-FDG PET alone were observed for 38 of them.

CONCLUSIONS

Our study findings suggest a higher prevalence of lesions in the bones of the lower limbs and pelvis among children with CRMO. Compared with CT scans, FDG PET exhibits superior sensitivity in detecting these lesions.

Chronic non-bacterial osteomyelitis (CNO) in childhood and adolescence - a disease with many faces

BACKGROUND

 Chronic non-bacterial osteomyelitis (CNO) is a chronic inflammatory skeletal disease that affects particularly children and adolescents and is often diagnosed with a delay. With whole-body MRI, early diagnosis of this disease is possible in many cases. Since children and adolescents frequently present with non-specific complaints for outpatient radiological diagnosis, every radiologist should have basic knowledge of this complex clinical picture.

MATERIALS

 In this review the basics and current findings regarding the disease are discussed. Unusual courses are also presented.

RESULTS AND CONCLUSION

 With knowledge of the radiographic and MR tomographic characteristics of the mostly multifocal bone lesions, the diagnosis of CNO can be reliably made in many cases. In particular, the early use of whole-body MRI plays an important role. Thus, therapeutic delays and resulting complications and the number of unnecessary biopsies for diagnosis can be reduced.

Whole-Body MRI at Initial Presentation of Chronic Recurrent Multifocal Osteomyelitis, Juvenile Idiopathic Arthritis, Their Overlapping Syndrome, and Non-Specific Arthropathy

(1) Background: Whole-body magnetic resonance imaging (WB-MRI) is central to defining total inflammatory burden in juveniles with arthritis. Our aim was to determine and compare the initial distribution of lesions in the WB-MRI in patients with chronic recurrent multifocal osteomyelitis (CRMO), juvenile idiopathic arthritis (JIA), their overlapping syndrome (OS), and with Non-specific Arthropathy (NA). (2) Methods: This retrospective single center study was performed on an Avanto 1.5-T MRI scanner with a dedicated multichannel surface coil system. A total of 173 pediatric patients were included with the following final diagnoses: CRMO (15.0%), JIA (29.5%), OS (4.6%), and NA (50.9%). (3) Results: Bone marrow edema (BME) was the most common abnormality, being seen in 100% patients with CRMO, 88% with OS, 55% with JIA, and 11% with NA. The bones of the lower extremities were the most affected in all compared entities. Effusion was seen in 62.5% children with OS, and in 52.9% with JIA, and in CRMO and NA, the exudate was sporadic. Enthesitis was found in 7.8% of patients with JIA and 3.8% with CRMO, and myositis was seen in 12.5% of patients with OS and in 3.9% with JIA. (4) Conclusions: The most frequent indication for WB-MRI in our center was JIA. The most common pathology in all rheumatic entities was BME, followed by effusion mainly seen in in OS and JIA. Enthesitis and myositis were less common; no case was observed in NA.

MRI features of spinal chronic recurrent multifocal osteomyelitis/chronic non-bacterial osteomyelitis in children

BACKGROUND

Spinal lesions in pediatric chronic recurrent multifocal osteomyelitis/chronic non-bacterial osteomyelitis (CRMO/CNO) can cause permanent sequelae; thus, early recognition of these is vital for management.

OBJECTIVE

To characterize the MR imaging features and patterns of pediatric spinal CRMO/CNO.

MATERIALS AND METHODS

This cross-section study received IRB approval. The first available MRI with documented spine involvement in children with CRMO/CNO was reviewed by a pediatric radiologist. Descriptive statistics were used to describe the characteristics of vertebral lesions, disc involvement, and soft tissue abnormality.

RESULTS

Forty-two patients were included (F:M, 30:12); median age was 10 years (range 4-17). At diagnosis, 34/42 (81%) had spine involvement. Kyphosis in 9/42 (21%) and scoliosis in 4/42 (9.5%) patients were present at the time of spinal disease recognition. Vertebral involvement was multifocal in 25/42 (59.5%). Disc involvement was found in 11/42 (26%) patients, commonly in the thoracic spine and often with adjacent vertebrae height loss. Posterior element abnormalities were present in 18/42 patients (43%) and soft tissue involvement in 7/42 (17%). One hundred nineteen vertebrae were affected, commonly the thoracic vertebrae (69/119; 58%). Vertebral body edema was focal in 77/119 (65%) and frequently superior (42/77; 54%). Sclerosis and endplate abnormality were present in 15/119 (13%) and 31/119 (26%) vertebrae, respectively. Height loss was present in 41/119 (34%).

CONCLUSION

Chronic non-bacterial osteomyelitis of spine is usually thoracic. Vertebral body edema is often focal at the superior vertebral body. Kyphosis and scoliosis occur in a quarter and vertebral height loss in a third of children at spinal disease recognition.

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

Chronic recurrent multifocal osteomyelitis (CRMO) is a non-infectious inflammatory disorder resulting from the multifocal bone and bone marrow lesions with periodic relapses and remissions and with an uncertain prognosis. Treatment options in CRMO are based on expert opinion and relatively small groups of patients. A nine-year-old female patient with no significant past medical history presented with compression fractures and multifocal bone lesions in the thoracic and lumbar spine, as shown in imaging (CT, MRI). Densitometry revealed a diffuse decrease in bone density. Based on the patient’s clinical image and above examinations, the other possible aetiologies—infectious (including tuberculosis), neoplasms, Langerhans cell histiocytosis—were ruled out, which led to eventual final diagnosis—CRMO. The patient was successfully treated with pamidronate infusion initiated in cycles over three consecutive days every 3 months. In addition to clinical improvement, there was a significant remission of inflammation and bone structure healing assessed by MRI after four treatment cycles. Intravenous bisphosphonates usage seems to be a good therapeutic option in CRMO paediatric patients with spinal localization of the lesions complicated by compressive fractures. However, more data, based on larger patient populations, are needed to provide a detailed paediatric CRMO treatment algorithm.

Advances in Bone Marrow Imaging: Strengths and Limitations from a Clinical Perspective

Conventional magnetic resonance imaging (MRI) remains the modality of choice to image bone marrow. However, the last few decades have witnessed the emergence and development of novel MRI techniques, such as chemical shift imaging, diffusion-weighted imaging, dynamic contrast-enhanced MRI, and whole-body MRI, as well as spectral computed tomography and nuclear medicine techniques. We summarize the technical bases behind these methods, in relation to the common physiologic and pathologic processes involving the bone marrow. We present the strengths and limitations of these imaging methods and consider their added value compared with conventional imaging in assessing non-neoplastic disorders like septic, rheumatologic, traumatic, and metabolic conditions. The potential usefulness of these methods to differentiate between benign and malignant bone marrow lesions is discussed. Finally, we consider the limitations hampering a more widespread use of these techniques in clinical practice.

Two phenotypes of chronic recurrent multifocal osteomyelitis with different patterns of bone involvement

INTRODUCTION

Chronic Recurrent Multifocal Osteomyelitis (CRMO) is an autoinflammatory bone disorder with predominantly paediatric onset. Children present with multifocal osteolytic lesions accompanied by bone pain and soft tissue swelling. Patients often exhibit extraosseous co-morbidities such as psoriasis, inflammatory bowel disease, and arthritis.

OBJECTIVES

Comparison of children with two different phenotypes of CRMO defined by presence or absence of extraosseous co-morbidities.

METHODS

Children diagnosed with CRMO at the Motol University Hospital between 2010 and 2020 were retrospectively reviewed, and according to the absence or presence of extraosseous manifestations divided into two cohorts - bone limited CRMO and complex CRMO. The two groups were compared in terms of demographic data, age at disease onset, number and site of bone lesions, laboratory biomarker values, and need of escalation to a second-line therapy.

RESULTS

Thirty-seven children (30 female, 7 male) with confirmed CRMO were included in the analysis. The mean age at disease onset was 10 years. All but 3 patients presented with multifocal disease. Twenty-three children (62%) had at least one extraosseous manifestation (13 sacroiliitis, 8 inflammatory bowel disease, 6 skin disease [acne, pustulosis, or psoriasis], 7 arthritis). Complex CRMO was associated with a significantly higher ESR rate (p = 0.0064) and CRP level (p = 0.018). The groups did not differ in number of foci or in age at disease onset. Bone lesion distribution differed between the two groups with significantly more frequent involvement of clavicle (p = 0.011) and pelvis (p = 0.038) in patients with complex CRMO. Children with complex CRMO more often needed escalation of therapy to DMARDs and biologic agents.

CONCLUSION

Our data suggest that CRMO affecting solely the skeleton has milder course compared to complex CRMO with extraskeletal features. Further studies are needed to explore the clinical as well as the patient reported outcomes and promote individually tailored therapeutic strategies in both CRMO phenotypes.

Whole-body MRI at initial presentation of pediatric chronic recurrent multifocal osteomyelitis and correlation with clinical assessment

BACKGROUND

Chronic recurrent multifocal osteomyelitis (CRMO) is a diagnosis of exclusion, relying heavily on whole-body magnetic resonance imaging (WB-MRI) for diagnosing and evaluating response to therapy. Information with respect to disease distribution and imaging correlation with clinical disease severity at initial presentation is lacking.

OBJECTIVE

To retrospectively characterize distribution of disease on WB-MRI and to correlate imaging findings with disease severity at initial rheumatology presentation.

MATERIALS AND METHODS

Using a modified version of a recently devised imaging-based scoring system, we evaluated disease distribution and correlation between findings on WB-MRI and clinical disease severity in 54 patients presenting for initial evaluation of CRMO. Symptomatic lesion sites were extracted from chart review and physician global assessment was determined by the consensus of two rheumatologists.

RESULTS

Sites of CRMO involvement evident on imaging at initial presentation had a strong predilection for the pelvis and lower extremities. There was significant correlation between the number of lesions detected on WB-MRI and total clinical severity score at initial rheumatology presentation (P<0.01). However, no other imaging parameter correlated with disease severity.

CONCLUSION

While the overall number of lesions identified on MRI correlates with clinical severity scores at initial imaging, other MR parameters of CRMO lesions may not be reliable indicators of disease severity at initial presentation. Further research is needed to assess whether these parameters are implicated in longitudinal disease severity or overall response to therapy.

Chronic nonbacterial osteomyelitis: the role of whole-body MRI

Background

Chronic nonbacterial osteomyelitis (CNO), also known as chronic recurrent multifocal osteomyelitis, is a noninfectious autoinflammatory disorder that occurs primarily in children and adolescents and is characterized by episodic musculoskeletal pain with a protracted course.

Main body

Traditionally, the diagnosis of CNO is made by exclusion and commonly requires bone biopsy to rule out infection and malignancy. However, bone biopsy may be avoided when imaging and clinical characteristic features are present, such as multifocal bone lesions at typical sites, no constitutional symptoms and no signs of infection in laboratory test results. Whole-body magnetic resonance imaging (WB-MRI) can assess signs of acute and chronic inflammation and enables the detection of CNO typical patterns of lesion location and distribution, thereby helping to exclude differential diagnosis. The goal of the present study paper is to review the main clinical and imaging aspects of the disease with emphasis on the role of WB-MRI in the diagnosis, assessment of disease burden and follow-up monitoring.

Conclusion

Radiologists need to be familiar with the imaging features to suggest the diagnosis as the early therapy may help to avoid irreversible secondary damage of skeletal system.

Chronic recurrent multifocal osteomyelitis. A narrative and pictorial review

Chronic recurrent and multifocal osteomyelitis (CRMO) is a nonsporadic autoinflammatory disorder. Currently, it is diagnosed based on clinical, radiologic, pathological, and longitudinal data. Numerous aspects should be highlighted due to increased knowledge in imaging and immunology. We emphasize the use of whole-body MRI, which is a non-invasive diagnostic strategy. A literature review was carried out on longitudinal studies. Commonly, the mean age at diagnosis is 11 years, ranging between 3 and 17. The most common sites are the long bone metaphysis, particularly femoral and tibial metaphysis. In addition, the pelvis, spine, clavicle, and mandible may be involved. In long bones, the radiologic appearance can show typical structure, mixed lytic and sclerotic, sclerotic or lytic. It is frequently metaphyseal or juxta-physeal, with hyperostosis or periosteal thickening. The involvement of the vertebral skeleton is often multifocal. Therefore, whole-body MRI is essential in identifying subclinical lesions. CRMO is a polymorphic disorder in which whole-body MRI is beneficial to demonstrate subclinical edema. Vertebral collapse requires long-term monitoring.

Improving protocols for whole-body magnetic resonance imaging: oncological and inflammatory applications

Whole-body MRI is increasingly used in the evaluation of a range of oncological and non-oncological diseases in infants, children and adolescents. Technical innovation in MRI scanners, coils and sequences have enabled whole-body MRI to be performed more rapidly, offering large field-of-view imaging suitable for multifocal and multisystem disease processes in a clinically useful timeframe. Together with a lack of ionizing radiation, this makes whole-body MRI especially attractive in the pediatric population. Indications include lesion detection in cancer predisposition syndrome surveillance and in the workup of children with known malignancies, and diagnosis and monitoring of a host of infectious and non-infectious inflammatory conditions. Choosing which patients are most likely to benefit from this technology is crucial, but so is adjusting protocols to the patient and disease to optimize lesion detection. The focus of this review is on protocols and the elements impacting image acquisition in pediatric whole-body MRI. We consider the practical aspects, from scanner and coil selection to patient positioning, single-center generic and indication-specific protocols with technical parameters, motion reduction strategies and post-processing. When optimized, collectively these lead to better standardization of whole-body MRI, and when married to systematic analysis and interpretation, they can improve diagnostic accuracy.

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

Background:

Chronic nonbacterial osteomyelitis (CNO) is a pediatric autoinflammatory disorder presenting with sterile inflammatory bone lesions. Whole-body MRI (WBMRI) has most recently emerged for disease assessment, but data are limited.

Purpose:

The purpose is to evaluate the imaging findings and patterns of CNO on WBMRI in a series of Greek pediatric patients.

Material and Methods:

Whole-body magnetic resonance imaging studies of all children with documented CNO, performed in a single tertiary center, were retrospectively reviewed. WBMRI included coronal T1 and short-tau inversion recovery (STIR), whole spine sagittal STIR, and ankle/foot sagittal STIR images. High signal intensity lesions on STIR images corresponding to bone marrow edema were recorded. The SPSS v.20 statistical package was used for descriptive statistics.

Results:

Twenty children were included (mean age: 12, range: 6–16 years) with 1–31 lesions (mean: 11.8) on WBMRI. Two children had unifocal disease localized at the clavicle, three paucifocal (1–4 lesions), and 15 multifocal bone involvement. All but two children presented with ankle pain and exhibited lesions at the bones of the ankle joint (90%) followed by the knee (50%) and pelvis (10%). The tibia was the most frequently affected bone (70%) followed by calcaneus (60%), fibula (50%), femur (45%), talus, and metatarsals (45%). No lesions in the cervical, thoracic, lumbar spine, and mandible were documented. Only small sacral lesions were seen in 25% of patients with the extensive peripheral disease. Bilateral metaphyseal and epiphyseal involvement with transphyseal extension were common, but the periosteal reaction and well-defined lesion margins were rare.

Conclusion:

Frequent involvement of the foot and ankle and paucity of substantial spinal involvement were seen in Greek pediatric patients with CNO.

Spectrum of anatomical variants, normal findings and pathology in and around the paediatric sternum

Abnormalities of the sternum and adjacent structures are an uncommon presentation in the paediatric population and can have a variety of benign and malignant causes, including normal and developmental variants of the chest wall. Although there is overlap with adults, many sternal abnormalities are unique to the paediatric population. Following clinical examination, radiography is usually the first type of imaging used; however, it is limited and often ultrasound and cross-sectional imaging are needed for further assessment. An understanding of the normal anatomy is important; however, this can be challenging due to the varied appearances of age-related changes of the sternum. The purpose of this article is to familiarize the general paediatric radiologist with the expected anatomy and imaging findings of the developing sternum, anatomical variants and pathology of the sternum and adjacent structures encountered in this group of patients.

MRI in the Diagnosis and Treatment Response Assessment of Chronic Nonbacterial Osteomyelitis in Children and Adolescents

PURPOSE OF REVIEW

To explain the central role of magnetic resonance imaging (MRI) in the diagnosis and follow-up of chronic nonbacterial osteomyelitis (CNO) in children and adolescents, centering on practical technical aspects and salient diagnostic features.

RECENT FINDINGS

In the absence of conclusive clinical features and widely accepted laboratory tests, including validated disease biomarkers, MRI (whether targeted or covering the entire body) currently plays an indispensable role in the diagnosis and therapy response assessment of CNO. Whole-body MRI, which is the reference imaging standard for CNO, can be limited to a short tau inversion recovery (STIR) coronal image set covering the entire body and a STIR sagittal set covering the spine, an approximately 30-min examination with no need for intravenous contrast or diffusion-weighted imaging. The hallmark of CNO is periphyseal (metaphyseal and/or epi-/apophyseal) osteitis, identified as bright foci on STIR, with or without inflammation of the adjacent periosteum and surrounding soft tissue. Response to bisphosphonate treatment for CNO has some unique MRI findings that should not be mistaken for residual or relapsing disease. Diagnostic features and treatment response characteristics of MRI in pediatric CNO are discussed, also describing the techniques used, pitfalls encountered, and differential diagnostic possibilities considered during daily practice.

Ultrasound evaluation of inflammation in patients with chronic recurrent multifocal osteomyelitis involving the mandible: report of three cases

Chronic recurrent multifocal osteomyelitis (CRMO) is aseptic and can be diagnosed by excluding other diseases, such as bacterial osteomyelitis, scurvy, metabolic disorders, and malignant diseases; therefore, bone biopsy is usually performed to confirm the diagnosis. To prevent misdiagnosis, the appropriate timing and location for biopsy should be determined from an active phase of inflammation. We presented 3 cases of CRMO involving the mandible: Case 1: A 2-year-old girl diagnosed with CRMO in the chronic phase. A sonogram showed a slightly low echoic area adjacent to the bone cortex. Pathological examination revealed a slight accumulation of leukocytes and plasma cells, as well as predominant fibrous stroma. Case 2: A 9-year-old girl diagnosed with CRMO with massive new osteoid formation. A sonogram showed a massive inhomogeneous low echoic area adjacent to the bone cortex. Pathological examination revealed massive osteoid formation and scattered inflammatory cells infiltration. Case 3: A 3-year-old girl diagnosed with CRMO in the active phase. A sonogram showed a massive hypoechoic area adjacent to the bone cortex and hyperechogenicity associated with a muscular and subcutaneous edema. Pathological examination revealed massive bone destruction and neutrophils infiltration within damaged osteoid. Ultrasound was able to visualize the degree of inflammation in the mandible corresponding to that of the surrounding soft tissue in all 3 cases. Therefore, ultrasound would be useful in determining the appropriate timing and location for bone biopsy.

Bone and Joint Infections: The Role of Imaging in Tailoring Diagnosis to Improve Patients' Care

Imaging is needed for the diagnosis of bone and joint infections, determining the severity and extent of disease, planning biopsy, and monitoring the response to treatment. Some radiological features are pathognomonic of bone and joint infections for each modality used. However, imaging diagnosis of these infections is challenging because of several overlaps with non-infectious etiologies. Interventional radiology is generally needed to verify the diagnosis and to identify the microorganism involved in the infectious process through imaging-guided biopsy. This narrative review aims to summarize the radiological features of the commonest orthopedic infections, the indications and the limits of different modalities in the diagnostic strategy as well as to outline recent findings that may facilitate diagnosis.

Review of spinal involvement in Chronic recurrent multifocal osteomyelitis (CRMO): What radiologists need to know about CRMO and its imitators

Chronic recurrent multifocal osteomyelitis (CRMO) is a distinct disease entity of unknown etiology primarily affecting children and adolescents. It is an autoinflammatory process that typically affects multiple bones with a waxing and waning course. About one third of the patients diagnosed with CRMO have spinal involvement which can lead to long term morbidity. The clinical presentation and imaging features of CRMO involving the spine are nonspecific and can mimic other disease processes like infection or malignancy. Since imaging plays a very important role in the diagnosis and management of CRMO, we intend to highlight various imaging patterns of spinal CRMO alongside its clinical features and briefly discuss its imitators, management and outcomes.

Imaging update in inflammatory arthritis

Ultrasonography and magnetic resonance imaging have become important imaging modalities in rheumatological disorders next to standard radiography. Due to their ability to assess both morphological and functional changes they play a significant role in early diagnosis and treatment monitoring. This review presents the latest advancements in imaging of inflammatory arthritis with a focus on two main groups of rheumatic diseases: connective tissue diseases and spondyloarthritis. New developments related to peripheral and sacroiliac joints imaging are discussed, including Superb Micro Flow Imaging and Shear Wave Elastography in ultrasonography, as well as Whole Body MRI, quantitative MRI, and the recent advances in cartilage imaging in MRI, including T2-and T1p-mapping, and dGEMRIC. The role of emerging imaging techniques in the early diagnosis of inflammatory arthritis is discussed, including DECT, VIBE, BoneMRI, and pQCT.

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

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.

Imaging of Joints and Bones in Autoinflammation

Autoinflammatory disorders are commonly characterized by seemingly unprovoked systemic inflammation mainly driven by cells and cytokines of the innate immune system. In many disorders on this spectrum, joint and bone involvement may be observed and imaging of these manifestations can provide essential diagnostic information. This review aimed to provide a comprehensive overview of the imaging characteristics for major diseases and disease groups on the autoinflammatory spectrum, including familial Mediterranean fever (FMF), Behçet disease (BD), crystal deposition diseases (including gout), adult-onset Still's disease (AoSD), and syndromatic synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO)/chronic recurrent multifocal osteomyelitis (CRMO). Herein, we discuss common and distinguishing imaging characteristics, phenotypical overlaps with related diseases, and promising fields of future research.