Osteomyelitis in children

Prospects and challenges for the application of tissue engineering technologies in the treatment of bone infections

Osteomyelitis is a devastating disease caused by microbial infection in deep bone tissue. Its high recurrence rate and impaired restoration of bone deficiencies are major challenges in treatment. Microbes have evolved numerous mechanisms to effectively evade host intrinsic and adaptive immune attacks to persistently localize in the host, such as drug-resistant bacteria, biofilms, persister cells, intracellular bacteria, and small colony variants (SCVs). Moreover, microbial-mediated dysregulation of the bone immune microenvironment impedes the bone regeneration process, leading to impaired bone defect repair. Despite advances in surgical strategies and drug applications for the treatment of bone infections within the last decade, challenges remain in clinical management. The development and application of tissue engineering materials have provided new strategies for the treatment of bone infections, but a comprehensive review of their research progress is lacking. This review discusses the critical pathogenic mechanisms of microbes in the skeletal system and their immunomodulatory effects on bone regeneration, and highlights the prospects and challenges for the application of tissue engineering technologies in the treatment of bone infections. It will inform the development and translation of antimicrobial and bone repair tissue engineering materials for the management of bone infections.

Unremitting Pain and Fever in a 15-Year-Old Boy With Osteomyelitis

A previously healthy 15-year-old boy from a rural county in the southeastern United States was evaluated in the emergency department with fever and worsening toe pain in the absence of trauma. He initially presented to his primary care physician 4 weeks before with upper respiratory symptoms and was treated with corticosteroids for presumed reactive airway disease. His respiratory symptoms resolved. One week after this presentation, he developed fever and right great toe pain and presented to an outside hospital. Inflammatory markers were elevated. MRI confirmed a diagnosis of osteomyelitis with associated periosteal abscess. He was treated with intravenous antibiotics and drainage of the abscess. Ten days after his discharge from the outside hospital, he developed fever and had increasing drainage of the toe and pain refractory to oral pain medications. He presented to our facility for further evaluation. Repeat MRI and inflammatory markers corroborated his worsening disease, and he was admitted to the hospital for intravenous antibiotics and underwent serial surgical debridement. He developed painful subcutaneous nodules on his lower extremities and was found to have lung abnormalities on chest radiograph. A multispecialty team collaborated in the management of this patient and unveiled a surprising diagnosis.

Clinical experience of debridement combined with resorbable bone graft substitute mixed with antibiotic in the treatment for infants with osteomyelitis

BACKGROUND

Osteomyelitis (OM) is an uncommon disease that originates from many different mechanisms in children. Treatment often involves a combination of surgical debridement combined and antibiotic therapy. The purpose of this article is to evaluate the effect of debridement combined with a new resorbable bone graft substitute (RBGS) mixed with antibiotics in the treatment of infants with OM.

METHODS

Twenty-two patients diagnosed with OM at our institution underwent debridement combined with implantation of RBGS mixed with vancomycin within 48 h after admission. Clinical and epidemiological factors, preoperative and postoperative radiographs, and laboratory parameters, including white blood cell (WBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and neutrophil percentage (NEU%), were documented. The function of the involved extremity was evaluated at the final follow-up.

RESULTS

The mean age was 6.3 ± 4.8 months (range, 0.5 to 12 months). The mean duration of the symptoms was 14.5 ± 8.4 days (range, 2 to 30 days). The average length of hospitalization was 13.7 ± 6.2 days (range, 6 to 28 days). 13.64% (3/22) had positive results of purulent material obtained at the time of open biopsy and 18.18% (4/22) had positive blood cultures. The most common sites were located in the proximal femur (12), the distal femur (3), and the proximal humerus (3). Ten patients presented with concurrent pyogenic arthritis, while another 12 infants suffered from simple isolated hematogenous OM. The mean follow-up time was 3.0 ± 1.6 years (range, 1.0 to 6.0 years). Seven of 22 patients (31.82%) had complications such as limb length deformity (LLD), avascular necrosis (AVN), and pathologic subluxation of the hip. Fifteen out of 22 (68.18%) patients achieved good results. Additionally, patients who had concomitant pyogenic arthritis were more likely to develop complications than those with isolated OM (p = 0.02).

CONCLUSIONS

Early debridement combined with implantation of RBGS mixed with vancomycin in the treatment of infants with OM achieved acceptable results in this series. Compared to those with simple isolated OM, patients with secondary pyogenic arthritis had a more virulent course.

Calcium Phosphate as a Key Material for Socially Responsible Tissue Engineering

Socially responsible technologies are designed while taking into consideration the socioeconomic, geopolitical and environmental limitations of regions in which they will be implemented. In the medical context, this involves making therapeutic platforms more accessible and affordable to patients in poor regions of the world wherein a given disease is endemic. This often necessitates going against the reigning trend of making therapeutic nanoparticles ever more structurally complex and expensive. However, studies aimed at simplifying materials and formulations while maintaining the functionality and therapeutic response of their more complex counterparts seldom provoke a significant interest in the scientific community. In this review we demonstrate that such compositional simplifications are meaningful when it comes to the design of a solution for osteomyelitis, a disease that is in its natural, non-postoperative form particularly prevalent in the underdeveloped parts of the world wherein poverty, poor sanitary conditions, and chronically compromised defense lines of the immune system are the norm. We show that calcium phosphate nanoparticles, which are inexpensive to make, could be chemically designed to possess the same functionality as a hypothetic mixture additionally composed of: (a) a bone growth factor; (b) an antibiotic for prophylactic or anti-infective purposes; (c) a bisphosphonate as an antiresorptive compound; (d) a viral vector to enable the intracellular delivery of therapeutics; (e) a luminescent dye; (f) a radiographic component; (g) an imaging contrast agent; (h) a magnetic domain; and (i) polymers as viscous components enabling the injectability of the material and acting as carriers for the sustained release of a drug. In particular, calcium phosphates could: (a) produce tunable drug release profiles; (b) take the form of viscous and injectable, self-setting pastes; (c) be naturally osteo-inductive and inhibitory for osteoclastogenesis; (d) intracellularly deliver bioactive compounds; (e) accommodate an array of functional ions; (f) be processed into macroporous constructs for tissue engineering; and (g) be naturally antimicrobial. All in all, we see in calcium phosphates the presence of a protean nature whose therapeutic potentials have been barely tapped into.

Pediatric Humeral Osteomyelitis

BACKGROUND

Osteomyelitis is a common problem among the pediatric population. The humerus is the most commonly affected bone in the upper limb; however, there are relatively few series in the literature. This article retrospectively reviews a large number of cases of pediatric humeral osteomyelitis. We aim to further define the disease and its clinical course to aid in improved treatment.

METHODS

A 10-year retrospective review was performed of clinical records of pediatric humeral osteomyelitis at the 2 children's orthopaedic departments in the Auckland region. The Osteomyelitis Database was used to identify all cases between 1997 and 2007 at Starship Children's Hospital, and 1998 and 2008 at Middlemore's Kidz First Hospital.

RESULTS

Forty-nine patients were identified. Sixty-one percent were male with an average age of 4.2 years. Maori and Pacific Islanders were overrepresented. Seventy-eight percent were not using the limb, 70% complained of pain. Only 55% were febrile. White cell count, erythrocyte sedimentation rate, and C-reactive protein raised in 73%, 74%, and 79% of cases, respectively. X-ray, bone scintigraphy, and particularly magnetic resonance imaging were useful in radiologic diagnosis. Blood and tissue cultures revealed Staphylococcus aureus as the most common organism; there were 2 cases of community-acquired methicillin-resistant S. aureus. The distal humerus was more commonly affected. Fifty-three percent required surgery. Antibiotic therapy averaged 2.7 weeks intravenous and 2.6 weeks of oral therapy. There were 7 cases with adjacent septic arthritis, which had higher inflammatory markers. Major complications included 2 multiorgan failure and 1 growth disturbance.

CONCLUSIONS

Humeral osteomyelitis can be diagnosed with an appropriate history, clinical examination, and investigations. One should be aware of concurrent septic arthritis and be prepared to treat this urgently. Those children with septic arthritis were not using the limb and had higher inflammatory markers. Treatment with intravenous and oral antibiotics and surgical debridement/washout if indicated can lead to good clinical outcomes with minimal complications.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Oral antibiotics at discharge for children with acute osteomyelitis: a rapid cycle improvement project

BACKGROUND

Substantial evidence demonstrates comparable cure rates for oral versus intravenous therapy for routine osteomyelitis. Evidence adoption is often slow and in our centre virtually all patients with osteomyelitis were discharged on intravenous therapy.

OBJECTIVE

For patients with acute osteomyelitis admitted to the hospital medicine service, we aimed to increase the proportion of cases discharged on oral antibiotics to at least 70%.

METHODS

The setting for our observational time series study was a large academic children's hospital. The model for improvement and plan-do-study-act cycles were used to test, refine and implement interventions identified through our key driver diagram. Our multifaceted intervention included a shared decision-making tool, an order set in our electronic health record, and education to faculty and trainees. We also included an identify and mitigate intervention to target providers caring for children with osteomyelitis in near-real time and reinforce the evidence-based recommendations. Data were analysed on an annotated g-chart of osteomyelitis cases between patients discharged on intravenous antibiotics. Structured chart review was used to identify treatment failures as well as length of stay and hospital charges in preintervention and postintervention groups.

RESULTS

The osteomyelitis cases between patients discharged on intravenous antibiotics increased from a median of 0 preintervention to a maximum of 9 cases following our identify and mitigate intervention. The direction and magnitude of successive improvements observed satisfied criteria for special cause variation. Improvement has been sustained for 1 year. Treatment failure and complications were uncommon in preintervention and postintervention phases. No significant differences in length of stay or charges were detected.

CONCLUSIONS

Even for uncommon conditions, rapid and sustained evidence adoption is possible using quality improvement methods.

MR imaging of the paediatric foot and ankle

Radiography is the mainstay for initial evaluation of paediatric foot and ankle pathology. MRI is the preferred exam for further characterisation of the majority of these conditions. The modality features high sensitivity and specificity for this purpose with few exceptions. Findings on MRI will often dictate patient referral and further management, and are frequently required for surgical planning. This article will provide an overview of a variety of pathologies that afflict the foot and ankle in children. These include tarsal coalition, osteochondral lesions, osteonecrosis, osteochondroses, stress fractures, osteomyelitis, inflammatory arthritis, neoplasms of bone and soft tissue, and foreign bodies. Their respective imaging manifestations on MRI are the focus of the paper. Technical parameters and marrow signal variation are also discussed.

Diagnosis and triage of a patient with an extra-osseous fat fluid level

Extra-osseous fat fluid level is rarely seen in osteomyelitis, with only three magnetic resonance imaging (MRI) cases previously reported in the literature. The rarity of this finding is probably secondary to the extensive necrosis of bone marrow that needs to occur at a rapid phase for the fat to accumulate. However, an extra-osseous fat fluid level is a specific diagnostic sign of osteomyelitis in cases with otherwise equivocal imaging findings and should be reported as such, especially when associated with medullary bone destruction and in the absence of trauma.

Diagnosis and treatment of pediatric chronic osteomyelitis in developing countries: prospective study of 96 patients treated in Kenya

The authors carried out a prospective study on 96 patients they treated in Kenya for chronic osteomyelitis from 2000 to 2009. All the patients received orthopedic surgery and antibiotic therapy, when possible based on the antibiotic sensitivity test. Among the 90 patients with at least 12 months' follow-up, 11 had osteomyelitis relapse (12.2%) and recovery rate was therefore 87.8% with no resulting disability. Risk factors for osteomyelitis relapse were investigated and previous treatment with beta-lactamines, predisposing to onset of methycillin-resistant Staphylococcus aureus (MRSA) infections (P = 0.03, OR = 5.74), and onset of osteomyelitis in the metaepiphyseal region (P < 0.0001) resulted statistically significant. Aim of the study was to evaluate the validity of our treatment of chronic osteomyelitis in Kenya on the basis of outcome.

Gram-negative neonatal osteomyelitis: two case reports

Neonatal osteomyelitis is a rare and challenging diagnosis, particularly in the early onset period. Neonatal osteomyelitis is predominantly caused by Staphylococcus aureus with single bone involvement. Here, we report two cases of neonatal osteomyelitis in premature infants caused by Klebsiella pneumoniae with multiple bone lesions. Both cases presented with sepsis and meningitis and were initially diagnosed by incidental findings on plain films, with follow-up bone scan imaging. In both cases, diagnosis was timely and treatment was successful. These cases highlight the need to include neonatal osteomyelitis in the differential diagnosis when late-onset or prolonged neonatal sepsis is present, particularly because long-term outcome is dependent on rapid diagnosis and initiation of treatment.

Cortical bone fenestrations with continuous antibiotic irrigation to mediate hematogenous tibial osteomyelitis in children

The objective of this study was to evaluate the results of drainage and continuous antibiotic irrigation of the medullary canal to mediate hematogenous osteomyelitis of the tibia in children. Data were analyzed from 376 patients (388 tibiae) treated from January 1982 to December 2004. The average age at the time of surgery was 5 years and 9 months. The diagnosis of mediate hematogenous osteomyelitis was based on clinical examination, plain radiographs, scintigraphy, ultrasound, and bacterial cultures. Treatment included two groups: (i) group I [from January 1981 to September 1984 in 108 patients (112 tibiae)] who were operated on according to traditional surgical procedure (pus drainage), (ii) group II [from October 1984 to December 2004 in 268 patients (276 tibiae)] who were operated on according to cortical bone fenestrations with continuous antibiotic irrigation. Postoperative antibiotic(s) with the intravenous antibiotic therapy were administered for 2 weeks and oral antibiotic therapy for 4 weeks. The total time of antibiotic therapy was 6 weeks. There were 152 (40.4%) female and 224 (59.6%) male patients. Unilateral involvement was the most common, with the left tibia affected in 119 (31.6%) patients, and the right in 245 (65.2%). Both tibiae were involved in 12 (3.2%) patients. The average age at the time of operation was 5 years 9 months (range: 22 days-13 years, 7 months). All patients were classified as having a mediate stage of osteomyelitis. We attained good results in 50.9% of the patients in the group I, fair results in 7.1%, and poor results in 42% with pathologic fracture in eight tibiae. In group II, there were good results in 77.9%, fair results in 21.4%, and poor results in 0.7% tibiae with the development of chronic osteomyelitis and without pathologic fracture. In conclusion, this technique is generally safe and effective. We suggest that similar management might also be applied for hematogenous osteomyelitis of femur and humerus.

Diagnosis of osteomyelitis in children: utility of fat-suppressed contrast-enhanced MRI

OBJECTIVE

The purpose of this study was to determine whether the use of fat-suppressed contrast-enhanced MRI, compared with unenhanced MRI alone, increases reader confidence in the diagnosis of osteomyelitis and its complications in children.

MATERIALS AND METHODS

MRI studies of 78 skeletally immature children and adolescents (median age, 3.6 years) with suspected nonspinal osteomyelitis were reviewed in consensus by two readers. Unenhanced images were evaluated first and then contrast-enhanced MR images. Images were scored for the presence or absence of osteomyelitis, abscess, septic arthritis, and physeal involvement on a 5-point scale ranging from definitely absent to definitely present. Forty-two additional studies were evaluated to test interobserver agreement.

RESULTS

Osteomyelitis was clinically diagnosed in 40 cases (51%). There was no significant difference between the sensitivity and specificity of unenhanced MRI (p = 1.0) and those of contrast-enhanced MRI (p = 0.77) for the diagnosis of osteomyelitis. Nonetheless, there was a significant (p < 0.001) increase in confidence in the diagnosis of osteomyelitis and its complications. This increase in confidence was most pronounced for the diagnosis of abscess (46%). The addition of contrast enhancement was least useful in findings deemed definitely absent on unenhanced MR images.

CONCLUSION

Although it does not increase the sensitivity or specificity of the diagnosis, use of contrast-enhanced MRI does increase reader confidence in the diagnosis of osteomyelitis and its complications in cases in which bone or soft-tissue edema is found on unenhanced images. In the clear absence of edema on unenhanced images, however, contrast enhancement is not needed.

Prolonged intravenous therapy versus early transition to oral antimicrobial therapy for acute osteomyelitis in children

OBJECTIVES

Early transition from intravenous to oral antimicrobial therapy for acute osteomyelitis in children has been suggested as a safe and effective alternative to traditional prolonged intravenous therapy via central venous catheter, but no studies have directly compared these 2 treatment modalities. We sought to compare the effectiveness of early transition from intravenous to oral antimicrobial therapy versus prolonged intravenous antimicrobial therapy for the treatment of children with acute osteomyelitis.

METHODS

We conducted a retrospective cohort study of children aged 2 months to 17 years diagnosed with acute osteomyelitis between 2000 and 2005 at 29 freestanding children's hospitals in the United States to confirm the extent of variation in the use of early transition to oral therapy. We used propensity scores to adjust for potential differences between children treated with prolonged intravenous therapy and logistic regression to model the association of outcome (treatment failure rates within 6 months of diagnosis) and difference in the mode of therapy within hospitals and across hospitals.

RESULTS

Of the 1969 children who met inclusion criteria, 1021 received prolonged intravenous therapy and 948 received oral therapy. The use of prolonged intravenous therapy varied significantly across hospitals (10%-95%). The treatment failure rate was 5% (54 of 1021) in the prolonged intravenous therapy group and 4% (38 of 948) in the oral therapy group. There was no significant association between treatment failure and the mode of antimicrobial therapy. Thirty-five (3.4%) children in the prolonged intravenous therapy group were readmitted for a catheter-associated complication.

CONCLUSIONS

Treatment of acute osteomyelitis with early transition to oral therapy is not associated with a higher risk of treatment failures and avoids the risks of prolonged intravenous therapy through central venous catheters.

Undiagnosed Brodie abscess in a gymnast after surgical fixation of a tibial fracture

OBJECTIVE

This study presents a case of a posttraumatic subacute osteomyelitis in a child with leg pain.

CLINICAL FEATURES

A 10-year-old female gymnast with leg pain presented to a chiropractic clinic after having been treated over the previous year for a leg fracture. The patient had leg pain associated with prolonged use of her right leg, restlessness at night, and tenderness over the right tibia. The history did not suggest a mechanical cause of the patient's pain. All available radiographs were reviewed by the chiropractor; a diffuse lytic lesion with bone thickening and sclerosis was clearly visible in the area of the patient's chief complaint, representing a Brodie abscess.

INTERVENTION AND OUTCOME

The doctor of chiropractic sent the patient back to the hospital. She was treated first with oral antibiotics, which were not successful. She underwent surgery and recovered well.

CONCLUSION

Subacute osteomyelitis may have a diagnostic delay; thus, it is possible for a chiropractor to see this condition in the office. A good case history, examination, and radiographs are important for the diagnosis and to make a proper referral.

Complications of central venous catheters used for the treatment of acute hematogenous osteomyelitis

OBJECTIVE

To determine the complications and risk factors for complications associated with using central venous catheters (CVCs) for the treatment of acute hematogenous osteomyelitis (AHO).

METHODS

We conducted a retrospective cohort study of all patients admitted to the Children's Hospital of Philadelphia between January 1, 2000, and December 31, 2003, with a diagnosis of AHO.

RESULTS

Eighty patients with AHO met inclusion criteria. The median age was 5 years, and 66% of the patients were male. The most commonly affected bones were the femur (25%), tibia (20%), and pelvis (16%). Staphylococcus aureus was the most common organism identified from cultures of bone (67%) and blood (30%). Seventy-five patients (94%) received >2 weeks of intravenous (IV) antibiotic therapy via a CVC and 5 (6%) received <2 weeks of IV antibiotic therapy before conversion to oral therapy for a median of 25 days. None of the patients who switched to oral therapy within 2 weeks was rehospitalized or returned to the emergency department. Of the 75 patients who received >2 weeks of IV therapy, 41% had > or =1 CVC-associated complication. Seventeen patients (23%) had a CVC malfunction or displacement, 8 (11%) had a catheter-associated bloodstream infection, 8 (11%) had fever with negative blood culture results, and 4 (5%) had a local skin infection at the site of catheter insertion. Older age was protective against the development of a CVC-associated complication, whereas the lowest median household income was associated with development of a CVC-associated complication.

CONCLUSIONS

Interventions to reduce CVC-associated complications should be developed and evaluated, particularly for young children and those from families with low household incomes. Clinical trials are needed to evaluate the safety and efficacy of oral antibiotic therapy after a short course of IV therapy as an alternative to prolonged IV therapy.

Musculoskeletal infections in children

Serious musculoskeletal infections in children include osteomyelitis, septic arthritis, pyomyositis, and necrotizing fasciitis. The epidemiology, pathophysiology, and microbiology of each of these infections are reviewed. Specific diagnostic studies and management strategies are discussed. Prompt recognition and treatment is emphasized to prevent potential long-term sequelae.

In vitro tobramycin elution analysis from a novel ?-tricalcium phosphate-silicate-xerogel biodegradable drug-delivery system

This in vitro research analyzed local tobramycin elution characteristics from a novel, biodegradable drug delivery system, consisting of a beta-TCP bone substitute, VITOSS trade mark, encapsulated with silicate xerogel prepared by the sol-gel process. Tobramycin elution from silicate-xerogel-encapsulated VITOSS was compared directly with non-silicate-xerogel-encapsulated VITOSS to assess whether xerogels are effective in delivering greater tobramycin quantities in a controllable, sustained manner crucial for microbial inhibition. Tobramycin elution characteristics indicate an initial release maximum during the first 24 h that diminishes gradually several days after impregnation. The copious tobramycin quantity eluted from the VITOSS/silicate-xerogel systems is attributed to various factors: the intrinsic ultraporosity and hydrophilicity of VITOSS, the ability of tobramycin to completely dissolve in aqueous media, tobramycin complexation with highly polar SO(4) (2-) salts that further assist dissolution, and ionic exchanges between VITOSS and the environment. Silicate-xerogel-encapsulated VITOSS eluted 60.65 and 61.31% of impregnated tobramycin, whereas non-silicate-xerogel-encapsulated VITOSS eluted approximately one-third less impregnated tobramycin, at 21.53 and 23.60%. These results suggest that silicate xerogel optimizes tobramycin elution because of its apparent biodegradability. This mechanism occurs through xerogel superficial acidic sites undergoing exchanges with various ions present in the leaching buffer. Tobramycin elution kinetics were evaluated, and demonstrate that first-order elution rate constants are considerably less when silicate xerogels are employed, following a more uniform exponential decay-type mechanism, thus bolstering controlled release. Overall, tobramycin elution rates adhere to linear-type Higuchi release profiles. Elution rate constants are initially first order, and taper into zero-order elution kinetics in the latter stages of release. Because VITOSS and silicate xerogel are completely biodegradable, essentially all impregnated tobramycin will be delivered to the surgical site after implantation.

Fosfomycin for the initial treatment of acute haematogenous osteomyelitis

BACKGROUND AND AIMS

At our institution there has been a dichotomous antimicrobial treatment behaviour for acute haematogenous osteomyelitis (AHOM) since 1984. The surgical department favoured fosfomycin as initial choice and the medical department beta lactams. We aimed to compare the performance of both strategies.

METHODS

Data from patients discharged with the diagnosis of AHOM between January 1984 and January 1998 were gathered from the charts by means of a questionnaire. Patients receiving fosfomycin treatment (FT) were compared with those receiving fosfomycin plus other antimicrobials (FT+) and those receiving no fosfomycin treatment (NFT).

RESULTS

A total of 103 patients aged 0.1-15.5 years (mean 6.5, median 6.9) with AHOM received no surgical treatment initially. In 23 (22.3%) FT was instilled initially, in 47 (45.6%) FT+, and in 33 (32.0%) NFT. The pathogen was established in 30%, 36%, and 42% of FT, FT+, and NFT patients, respectively, Staphylococcus aureus being the predominant isolate. Mean C reactive protein levels and erythrocyte sedimentation rates normalised in all treatment groups after two and four weeks, respectively. The mean duration of intravenous antimicrobial treatment in FT patients was 2.5 weeks, in FT+ patients 3.1 weeks, and in NFT patients 3.8 weeks (p < 0.05), whereas the mean duration of intravenous plus oral treatment was comparable (7.1 v 6.8 v 6.5 weeks).

CONCLUSIONS

The leucocyte penetrating fosfomycin performed similarly to extracellular beta lactams in the treatment of AHOM. Intravenous treatment for longer than 2.5 weeks offered no advantage.

Use of imaging in the differential diagnosis of rheumatic diseases in children

Imaging studies are important adjuncts in the evaluation of children with suspected rheumatic diseases. They are best used as follow-up investigations to exclude specific differential diagnoses, based upon a careful history and physical examination. Often, repeated examination over a period of time, sometimes months, is necessary before a diagnosis can be made. The addition of selected imaging studies can be important in the common circumstance where no diagnosis is made, but the physician must assure the child and family that all appropriate efforts have been made to exclude important illnesses.