Imaging Approach to Acute Hematogenous Osteomyelitis in Children: An Update

Imaging Osteomyelitis: An Update

BACKGROUND

 Hematogenous osteomyelitis has increased over the past quarter century in frequency, virulence, and degree of soft-tissue involvement, bringing about changes in clinical manifestations and management of the disease especially in children that should be reflected in the current imaging approach. Likewise, the global disease burden of diabetes has increased greatly in the same period, compounding the problem of ascertaining osteomyelitis in diabetic foot.

METHOD

 This article provides an updated overview of imaging findings in hematogenous and contiguous osteomyelitis based on the literature and our institutional experience, along with salient features of recent recommendations from expert groups on the diagnostic algorithms and reporting terminology.

RESULTS AND CONCLUSION

 Findings on radiography and especially magnetic resonance imaging (MRI) closely reflect pathophysiology in osteomyelitis, whereby the characteristic involvement of the metaphysis or metaphyseal-equivalents, the formation and subperiosteal extension of intramedullary pus collection, and the development of cloaca, sequestrum, and involucrum are all diagnostic clues. Non-enhancing foci within the medullary bone, the penumbra sign, intra- or extramedullary fat globules, and surrounding soft tissue inflammation or abscesses are among key MRI findings. Diabetic foot is a special condition with characteristic pathophysiologic and imaging features that suggest the likelihood of osteomyelitis and the main differential diagnostic consideration of acute on chronic neuropathic osteoarthropathy with or without osteomyelitis.

KEY POINTS

  · Imaging closely reflects pathophysiology in hematogenous osteomyelitis.. · Acute hematogenous osteomyelitis predominantly involves metaphyses and metaphyseal equivalent sites.. · MRI clues for hematogenous osteomyelitis include central marrow non-enhancement, intra- or extramedullary fat globules, and the "penumbra" sign.. · An increased fluid-sensitive MRI bone signal abutting a soft tissue ulcer, abscess, or sinus tract suggests a high probability of contact osteomyelitis..

CITATION FORMAT

· Aydingoz U, Imaging Osteomyelitis: An Update. Fortschr Röntgenstr 2023; DOI: 10.1055/a-1949-7641.

ACR Appropriateness Criteria® Osteomyelitis or Septic Arthritis-Child (Excluding Axial Skeleton)

Imaging plays an integral role in the evaluation of suspected musculoskeletal infections in children, not only in the accurate identification of infection such as osteomyelitis or septic arthritis, but also in guiding management. Various diagnostic modalities serve different purposes in the assessment of suspected pediatric musculoskeletal infections. The purpose of this document is to provide imaging guidance in the most frequently encountered clinical scenarios in which osteomyelitis and/or septic arthritis are suspected, outside of the axial skeleton. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion.

Pediatric Musculoskeletal Infections: Imaging Guidelines and Recommendations

Pediatric musculoskeletal infections often pose a diagnostic challenge due to their frequently vague and nonspecific clinical presentation. Imaging evaluation is a crucial component to diagnostic workup of these entities. Changed epidemiology of these infections over the past 2 decades has resulted in increases in both disease incidence and severity in the pediatric population. Prompt and accurate diagnosis is essential in order to reduce the risk of morbid sequelae, and to optimize patient management. In this article, the unique pathophysiology of musculoskeletal infections and characteristic imaging findings in children compared with adults are reviewed.

Clinical Practice Guideline by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America: 2021 Guideline on Diagnosis and Management of Acute Hematogenous Osteomyelitis in Pediatrics

This clinical practice guideline for the diagnosis and treatment of acute hematogenous osteomyelitis (AHO) in children was developed by a multidisciplinary panel representing Pediatric Infectious Diseases Society (PIDS) and the Infectious Diseases Society of America (IDSA). This guideline is intended for use by healthcare professionals who care for children with AHO, including specialists in pediatric infectious diseases, orthopedics, emergency care physicians, hospitalists, and any clinicians and healthcare providers caring for these patients. The panel's recommendations for the diagnosis and treatment of AHO are based upon evidence derived from topic-specific systematic literature reviews. Summarized below are the recommendations for the diagnosis and treatment of AHO in children. The panel followed a systematic process used in the development of other IDSA and PIDS clinical practice guidelines, which included a standardized methodology for rating the certainty of the evidence and strength of recommendation using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. A detailed description of background, methods, evidence summary and rationale that support each recommendation, and knowledge gaps can be found online in the full text.

Imaging tests for the detection of osteomyelitis: a systematic review

BACKGROUND

Osteomyelitis is an infection of the bone. Medical imaging tests, such as radiography, ultrasound, magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT) and positron emission tomography (PET), are often used to diagnose osteomyelitis.

OBJECTIVES

To systematically review the evidence on the diagnostic accuracy, inter-rater reliability and implementation of imaging tests to diagnose osteomyelitis.

DATA SOURCES

We conducted a systematic review of imaging tests to diagnose osteomyelitis. We searched MEDLINE and other databases from inception to July 2018.

REVIEW METHODS

Risk of bias was assessed with QUADAS-2 [quality assessment of diagnostic accuracy studies (version 2)]. Diagnostic accuracy was assessed using bivariate regression models. Imaging tests were compared. Subgroup analyses were performed based on the location and nature of the suspected osteomyelitis. Studies of children, inter-rater reliability and implementation outcomes were synthesised narratively.

RESULTS

Eighty-one studies were included (diagnostic accuracy: 77 studies; inter-rater reliability: 11 studies; implementation: one study; some studies were included in two reviews). One-quarter of diagnostic accuracy studies were rated as being at a high risk of bias. In adults, MRI had high diagnostic accuracy [95.6% sensitivity, 95% confidence interval (CI) 92.4% to 97.5%; 80.7% specificity, 95% CI 70.8% to 87.8%]. PET also had high accuracy (85.1% sensitivity, 95% CI 71.5% to 92.9%; 92.8% specificity, 95% CI 83.0% to 97.1%), as did SPECT (95.1% sensitivity, 95% CI 87.8% to 98.1%; 82.0% specificity, 95% CI 61.5% to 92.8%). There was similar diagnostic performance with MRI, PET and SPECT. Scintigraphy (83.6% sensitivity, 95% CI 71.8% to 91.1%; 70.6% specificity, 57.7% to 80.8%), computed tomography (69.7% sensitivity, 95% CI 40.1% to 88.7%; 90.2% specificity, 95% CI 57.6% to 98.4%) and radiography (70.4% sensitivity, 95% CI 61.6% to 77.8%; 81.5% specificity, 95% CI 69.6% to 89.5%) all had generally inferior diagnostic accuracy. Technetium-99m hexamethylpropyleneamine oxime white blood cell scintigraphy (87.3% sensitivity, 95% CI 75.1% to 94.0%; 94.7% specificity, 95% CI 84.9% to 98.3%) had higher diagnostic accuracy, similar to that of PET or MRI. There was no evidence that diagnostic accuracy varied by scan location or cause of osteomyelitis, although data on many scan locations were limited. Diagnostic accuracy in diabetic foot patients was similar to the overall results. Only three studies in children were identified; results were too limited to draw any conclusions. Eleven studies evaluated inter-rater reliability. MRI had acceptable inter-rater reliability. We found only one study on test implementation and no evidence on patient preferences or cost-effectiveness of imaging tests for osteomyelitis.

LIMITATIONS

Most studies included < 50 participants and were poorly reported. There was limited evidence for children, ultrasonography and on clinical factors other than diagnostic accuracy.

CONCLUSIONS

Osteomyelitis is reliably diagnosed by MRI, PET and SPECT. No clear reason to prefer one test over the other in terms of diagnostic accuracy was identified. The wider availability of MRI machines, and the fact that MRI does not expose patients to harmful ionising radiation, may mean that MRI is preferable in most cases. Diagnostic accuracy does not appear to vary with the potential cause of osteomyelitis or with the body part scanned. Considerable uncertainty remains over the diagnostic accuracy of imaging tests in children. Studies of diagnostic accuracy in children, particularly using MRI and ultrasound, are needed.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017068511.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 61. See the NIHR Journals Library website for further project information.

Imaging for detection of osteomyelitis in people with diabetic foot ulcers: A systematic review and meta-analysis

BACKGROUND

Osteomyelitis is an infection of the bone which can occur in people with diabetic foot ulcers. It can be diagnosed using X-rays, ultrasound, scintigraphy, magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT) and positron emission tomography (PET).

OBJECTIVES

To review the evidence on the diagnostic accuracy of imaging tests to diagnose osteomyelitis in people with diabetic foot ulcers.

METHODS

We conducted a systematic review and meta-analysis. MEDLINE, EMBASE and other databases were searched to July 2018. Risk of bias was evaluated. Diagnostic accuracy was estimated using bivariate meta-analyses.

RESULTS

Thirty-six studies were included in the meta-analysis. Eight studies were at high risk of bias MRI had high diagnostic accuracy (22 studies: 96.4 % sensitivity (95 % CI 90.7-98.7); 83.8 % specificity (76.0-89.5)). PET scans also had high accuracy (6 studies: 84.3 % sensitivity (52.8-96.3); 92.8 % specificity (75.7-98.2)), and possibly also SPECT, but with few studies (3 studies: 95.6 % sensitivity (76.0-99.3); 55.1 % specificity (19.3-86.3)). Scintigraphy (17 studies: 84.2 % sensitivity (76.8-89.6); 67.7 % specificity (56.2-77.4)), and X-rays (16 studies: 61.9 % sensitivity (50.5-72.1); 78.3 % specificity (62.9-88.5)) had generally inferior diagnostic accuracy.

CONCLUSIONS

MRI and PET both reliably diagnose osteomyelitis in diabetic foot ulcer patients. SPECT may also have good diagnostic accuracy, although evidence is limited. This review confirms most current guidelines, showing that MRI may be the preferable test in most cases, given its wider availability and the lack of potentially harmful ionising radiation.

Sonography of musculoskeletal infection in children

Musculoskeletal infection, especially in young children, often presents with non-specific clinical signs and symptoms necessitating early imaging to identify the source of infection. While MRI is the investigation of choice to demonstrate bone infection, it is expensive and often requires a general anaesthetic in the young child. Ultrasound can be a useful tool in the initial assessment due to its easy availability and portable equipment. It does not involve ionising radiation and is used to guide aspiration and drainage procedures. This review explains sonographic features of septic arthritis, osteomyelitis, pyomyositis and soft tissue infection in children and highlights advantages and limitations of sonography when assessing the child with suspected musculoskeletal infection.

Quality Improvement of Magnetic Resonance Imaging for Musculoskeletal Infection in Children Results in Decreased Scan Duration and Decreased Contrast Use

BACKGROUND

Magnetic resonance imaging (MRI) is a heavily utilized resource to evaluate children suspected to have a musculoskeletal infection. Complex interdisciplinary workflows are involved with decision-making with regard to indications, anesthesia, contrast use, and procedural timing relative to the scan. This study assesses the impact of a quality improvement endeavor on MRI workflows at a tertiary pediatric medical center.

METHODS

A registry of consecutively enrolled children for a multidisciplinary musculoskeletal infection program identified those evaluated with MRI from 2012 to 2018. Annual MRI process improvement feedback was provided to the key stakeholders. Demographic characteristics, laboratory parameters, MRI indications, anesthesia use, MRI findings, final diagnoses, scan duration, imaging protocol, surgical intervention following MRI, and length of stay were retrospectively compared between the 3 cohorts (initial, middle, and final) representing 2-year increments to assess the impact of the initiative.

RESULTS

There were 526 original MRI scans performed to evaluate 1,845 children with suspected musculoskeletal infection. Anesthesia was used in 401 children (76.2%). When comparing the initial, middle, and final study period cohorts, significant improvement was demonstrated for the number of sequences per scan (7.5 sequences for the initial cohort, 5.8 sequences for the middle cohort, and 4.6 sequences for the final cohort; p < 0.00001), scan duration (73.6 minutes for the initial cohort, 52.1 minutes for the middle cohort, and 34.9 minutes for the final cohort; p < 0.00001), anesthesia duration (94.1 minutes for the initial cohort, 68.9 minutes for the middle cohort, and 53.2 minutes for the final cohort; p < 0.00001), and the rate of contrast use (87.6% for the initial cohort, 67.7% for the middle cohort, and 26.3% for the final cohort; p < 0.00001). There was also a trend toward a higher rate of procedures under continued anesthesia immediately following the MRI (70.2% in the initial cohort, 77.8% in the middle cohort, and 84.6% in the final cohort). During the final 6-month period, the mean scan duration was 24.4 minutes, anesthesia duration was 40.9 minutes, and the rate of contrast administration was 8.5%.

CONCLUSIONS

Progressive quality improvement through collaborative interdisciplinary communication and workflow redesign led to improved utilization of MRI and minimized contrast use for suspected musculoskeletal infection. There was a high rate of procedural intervention under continued anesthesia for children with confirmed musculoskeletal infection.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

ACR Appropriateness Criteria® Acutely Limping Child Up To Age 5

Imaging plays in important role in the evaluation of the acutely limping child. The decision-making process about initial imaging must consider the level of suspicion for infection and whether symptoms can be localized. The appropriateness of specific imaging examinations in the acutely limping child to age 5 years is discussed with attention in each clinical scenario to the role of radiography, ultrasound, nuclear medicine, computed tomography, and magnetic resonance imaging. Common causes of limping such as toddler's fracture, septic arthritis, transient synovitis, and osteomyelitis are discussed. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Sonography of pediatric superficial lumps and bumps: illustrative examples from head to toe

Superficial lumps and bumps are extremely common in children, and the vast majority ultimately prove to be benign. Duplex/color Doppler ultrasound (US) has emerged as the first-line imaging modality for the evaluation of these superficial pediatric masses because it provides a means for rapid acquisition of information including size, shape, location, internal content and vascularity. More important, it does so without utilizing radiation, iodinated contrast material or sedation/anesthesia. In this review, we present the sonographic findings of a variety of cases ranging from head to toe that are either uncommonly seen or were diagnosed in an atypical fashion (i.e. ultrasound). In situations where the lesion is too deep, hyperechoic or large to be fully assessed within the field of view or if malignancy is suspected, then additional cross-sectional imaging is warranted for further evaluation.

Paediatric bone and joint infection

Despite advances in understanding and management, paediatric osteoarticular infections continue to pose diagnostic difficulties for clinicians. Delays in diagnosis can lead to potentially devastating morbidity.No single investigation, including joint aspiration, is sufficiently reliable to diagnose conclusively paediatric bone and joint infection. Diagnosis should be based on a combination of clinical signs, imaging and laboratory investigations. Algorithms should supplement, and not replace, clinical decision making in all cases.The roles of aspiration, arthrotomy and arthroscopy in the treatment of septic arthritis are not clearly defined. There is a very limited role for surgery in the management of acute haematogenous osteomyelitis.The ideal duration and mode of administration of antibiotic therapy for osteoarticular paediatric infection is not yet fully defined but there is increasing evidence that shorter courses (three weeks) and early conversion (day four) to oral administration is safe and effective in appropriate cases. Clear and concise antibiotic guidelines should be available based on local population characteristics, pathogens and their sensitivities.Kingella kingae is increasingly identified through polymerase chain reaction and is now recognised as the commonest pathogen in children aged under four years. Methicillin-resistant Staphylococcus aureus and Panton-Valentine leukocidin-producing strains of Staph. aureus are being increasingly reported.A multidisciplinary integrated evidence-based approach is required to optimise outcomes.Further large-scale, multicentre studies are needed to delineate the optimal management of paediatric osteoarticular infection. Cite this article: EFORT Open Rev 2017;1:7-12. DOI: 10.1302/2058-5241.2.160027.

Blood perfusion in osteomyelitis studied with [15O]water PET in a juvenile porcine model

Background

Osteomyelitis is a serious disease which can be difficult to treat despite properly instituted antibiotic therapy. This appears to be related at least partly to degraded vascularisation in the osteomyelitic (OM) lesions. Studies of perfusion in OM bones are, however, few and not quantitative. Quantitative assessment of perfusion could aid in the selection of therapy. A non-invasive, quantitative way to study perfusion is dynamic [¹⁵O]water positron emission tomography (PET). We aim to demonstrate that the method can be used for measuring perfusion in OM lesions and hypothesize that perfusion will be less elevated in OM lesions than in soft tissue (ST) infection. The study comprised 11 juvenile pigs with haematogenous osteomyelitis induced by injection of Staphylococcus aureus into the right femoral artery 1 week before scanning (in one pig, 2 weeks). The pigs were dynamically PET scanned with [¹⁵O]water to quantify blood perfusion. OM lesions (N = 17) in long bones were studied, using the left limb as reference. ST lesions (N = 8) were studied similarly.

Results

Perfusion was quantitatively determined. Perfusion was elevated by a factor 1.5 in OM lesions and by a factor 6 in ST lesions.

Conclusions

Blood perfusion was successfully determined in pathological subacute OM lesions; average perfusion was increased compared to that in a healthy bone, but as hypothesized, the increase was less than in ST lesions, indicating that the infected bone has less perfusion reserve than the infected soft tissue.

Electronic supplementary material

The online version of this article (doi:10.1186/s13550-016-0251-2) contains supplementary material, which is available to authorized users.

Epidemiology and Management of Acute, Uncomplicated Septic Arthritis and Osteomyelitis: Spanish Multicenter Study

BACKGROUND

Acute osteoarticular infection (OAI) is a potentially severe disease. The aim of this study was to evaluate the etiology, clinical characteristics and therapeutic approach of OAI in children in Spain.

METHODS

Medical records from children <14 years with OAI from 25 hospitals between 2008 and 2012 were reviewed. Confirmed osteomyelitis (OM) and septic arthritis (SA) required a positive bacterial isolate; otherwise, they were considered probable. Probable SA with <40,000 cells/mm in joint fluid was not included.

RESULTS

A total of 641 children were evaluated. Two hundred and ninety-nine cases (46%) were OM, 232 (36%) SA, 77 (12%) osteoarthritis and 33 (5%) spondylodiscitis. Children with OM were older (63 vs. 43 months for SA; P < 0.001). Magnetic resonance imaging and bone scintigraphy had the highest yield for OM diagnosis (94%). Arthrocentesis was performed in 96% of SA. A microorganism was isolated in 246 patients (38%: 33% OM vs. 55% SA; P < 0.001): Staphylococcus aureus was the most common (63%), followed by Kingella kingae (15%) and Streptococcus pyogenes (9%). Ninety-five percent of children initially received IV antibiotics, mostly cefotaxime + cloxacillin (60%) or cloxacillin (40%). Total treatment duration was 38 (±31) days for OM and 28 (±16) days for SA (P < 0.0001). Twenty percent of children with OM (46% because of complications) and 53% with SA (95% initial arthrotomy) underwent surgery. Patients with SA were compared according to initial arthrotomy (n = 123) versus arthrocentesis (n = 109), and no clinical differences were observed, except for higher rate of hip SA in the former (50% vs. 9%; P < 0.001). Children with arthrocentesis had less sequelae [6.6% vs. 1%; P = 0.03, odds ratio = 0.58 (95% confidence interval: 0.45-0.76)], but not in the multivariate analysis.

CONCLUSIONS

This is the largest pediatric cohort of OAI in Spain. S. aureus was the most common isolate, although K. kingae was recovered in a high proportion of cases. Conservative management was applied in half of the patients. There was a low rate of sequelae, even with nonsurgical approaches.

Bone and Joint Infections in Children: Acute Hematogenous Osteomyelitis

Acute hematogenous osteomyelitis (AHO) is one of the commonest bone infection in childhood. Staphylococcus aureus is the commonest organism causing AHO. With use of advanced diagnostic methods, fastidious Kingella kingae is increasingly becoming an important organism in etiology of osteoarticular infections in children under the age of 3 y. The diagnosis of AHO is primarily clinical. The main clinical symptom and sign in AHO is pain and tenderness over the affected bone especially in the metaphyseal region. However, in a neonate the clinical presentation may be subtle and misleading. Laboratory and radiological investigations supplement the clinical findings. The acute phase reactants such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are frequently elevated. Ultrasonography and MRI are key imaging modalities for early detection of AHO. Determination of infecting organism in AHO is the key to the correct antibiotic choice, treatment duration and overall management and therefore, organism isolation using blood cultures and site aspiration should be attempted. Several effective antibiotics regimes are available for managing AHO in children. The choice of antibiotic and its duration and mode of delivery requires individualization depending upon severity of infection, causative organism, regional sensitivity patterns, time elapsed between onset of symptoms and child's presentation and the clinical and laboratory response to the treatment. If pus has been evidenced in the soft tissues or bone region, surgical decompression of abscess is mandatory.

Improved Magnetic Resonance Imaging Utilization for Children with Musculoskeletal Infection

BACKGROUND

Magnetic resonance imaging (MRI) with sedation is an important resource used to evaluate children with musculoskeletal infection. This study assesses the impact of multidisciplinary guidelines and continuous process improvement on MRI utilization at a tertiary pediatric medical center.

METHODS

A multidisciplinary team developed a guideline for MRI with sedation, and it was implemented at our institution. Scan duration, anatomic regions imaged, sequences performed, timing of surgical intervention, length of hospital stay, and readmissions for these children were compared with these measures among a cohort of similar children who had been treated prior to guideline implementation. Comparative data were gathered for the subsequent cohort to determine any impact of the continued process improvement program on MRI utilization. Statistical comparison was performed to determine significant differences between groups.

RESULTS

Children evaluated prior to the guideline implementation had 9.0 MRI sequences per scan, an MRI scan duration of 111.6 minutes, and a hospital stay of 7.5 days. In comparison, children in the initial MRI guideline cohort had 7.5 sequences per scan, a scan duration of 76.1 minutes, and a hospital stay of 5.4 days. Children in the subsequent guideline cohort had 6.5 sequences per scan, a scan duration of 56.3 minutes, and a hospital stay of 5.0 days. The rate of immediate surgical procedure under continued anesthesia was 16.7% prior to the guideline, 50.5% among children in the initial guideline cohort, and 64% among children in the subsequent guideline cohort. Differences between cohorts were significant (p < 0.0001). In aggregate, 264 hours of MRI scan time and 809 hospital bed-days were conserved for more than thirty months.

CONCLUSIONS

This initiative promoted improvement in diagnostic efficiency, therapeutic consistency, and patient safety for children with musculoskeletal infection.

CLINICAL RELEVANCE

The findings of this study illustrate the beneficial impact of interdisciplinary coordination of care on clinical outcomes for children with musculoskeletal infection. Tangible improvements occurred for both length of stay and resource utilization.

MRI of suspected lower extremity musculoskeletal infection in the pediatric patient: how useful is bilateral imaging?

OBJECTIVE

The purpose of this study was to determine the frequency of bilateral abnormalities in children with suspected lower extremity musculoskeletal infection and the impact of detection of contralateral abnormalities by MRI on patient management.

MATERIALS AND METHODS

A retrospective review of 165 consecutive bilateral lower extremity MRI examinations performed for suspected musculoskeletal infection in pediatric patients (64% boys and 36% girls; mean age, 7.5 years; age range, 0-18 years) in 2010 at a children's hospital was performed. Imaging findings were compared with the final clinical diagnosis and management.

RESULTS

The MRI examination was normal in 2% (4/165). Osteomyelitis was diagnosed in 33% (54/165) of the MRI examinations; among these examinations 20% (11/54) had both ipsilateral septic arthritis and osteomyelitis, 2% (1/54) had bilateral osteomyelitis, and 67% (111/165) of the examinations were negative for osteomyelitis. Bilateral abnormalities were detected in 20% (22/111) of patients without osteomyelitis, with 18% (4/22) presenting with bilateral signs or symptoms. Abnormalities in the contralateral extremity included myositis (18%, 4/22), stress reaction (18%, 4/22), subcutaneous edema (18%, 4/22), leukemia (14%, 3/22), reactive joint effusion (14%, 3/22), Baker cyst (5%, 1/22), and osteonecrosis (5%, 1/22). Identification of clinically unsuspected abnormalities of the contralateral extremity by MRI was not associated with alterations in medical or surgical management in children with or without osteomyelitis.

CONCLUSION

Clinically unsuspected abnormalities of the asymptomatic contralateral lower extremity are common in children referred for MRI of suspected musculoskeletal infection. However, detection of these abnormalities is not associated with alterations in patient management.

Childhood osteomyelitis: imaging characteristics

Background

The purpose of this review is to illustrate the imaging findings of childhood osteomyelitis. The diagnosis of childhood osteomyelitis can be challenging. Clinical presentation and laboratory results can differ and are relatively unreliable. To date, its role in the assessment of treatment efficacy is not yet clear.

Methods

This review article provides an overview of the different imaging modalities and imaging characteristics of childhood osteomyelitis. Levels of evidence for different modalities are presented.

Results

Paediatric radiology plays a pivotal role in the diagnosis of childhood osteomyelitis and can also be used to guide therapy and intervention.

Conclusion

Although imaging is essential in the diagnostic process, cooperation between the physician and radiologist remains the cornerstone in accurately diagnosing childhood osteomyelitis.

Main Messages

• Imaging plays a pivotal role in the diagnosis of childhood osteomyelitis.

• Cooperation between the clinician and radiologist is a very important aspect of making the diagnosis.

• The initial imaging modality in childhood osteomyelitis is conventional imaging.

• Normal conventional imaging does not exclude osteomyelitis.