Whole-body MRI in the pediatric patient

Physeal Abnormalities in Children With High-risk Neuroblastoma Intensively Treated With/Without 13-Cis-Retinoic Acid

BACKGROUND

This study aimed to investigate the presence of physeal abnormality and its effect on growth in children with high-risk neuroblastoma treated by intensive multimodal treatment with/without 13-cis-retinoic acid (13-CRA).

METHODS

Fifteen patients diagnosed with high-risk neuroblastomas at the age of 1 to 10 years, who received treatment such as high-dose chemotherapy and autologous stem cell transplantation with/without 13-CRA, and with complete data during their >2-year follow-up were retrospectively reviewed. The physeal abnormalities were investigated by whole-body magnetic resonance imaging, serially performed every 3 to 6 months. The patients' height growth was also investigated and compared with that of age-and-sex-matched patients with brain tumors who also underwent high-dose chemotherapy and autologous stem cell transplantation.

RESULTS

Six of 15 patients presented multifocal physeal abnormalities during follow-up, and all lesions occurred in patients with 13-CRA use. The lesions in 3 patients completely resolved spontaneously without any adverse effect on growth, but some lesions in the other 3 patients progressed to disturb the bony growth. Height growth of matched patients with brain tumors were not significantly different, and none of the matched controls showed definite bony deformity during the follow-up.

CONCLUSIONS

Some children who were treated for high-risk neuroblastomas experienced multifocal physeal insults, probably due to the use of 13-CRA. Most lesions resolved spontaneously, but some led to bony deformity. If the lesions are not followed by premature physeal closure, there seems to be no further adverse effect of 13-CRA on leg length growth. Routine periodic screening for physeal status is needed for the patients with high-risk neuroblastomas using 13-CRA.

LEVEL OF EVIDENCE

Level IV-prognostic study.

Panton-valentine leukocidin Staphylococcus aureus severe infection in an infant: a case report and a review of the literature

Background

Panton-Valentine leukocidin (PVL) is one of the major virulence factor of Staphylococcus aureus (SA) that might be associated with invasive life-threating infections. A prompt diagnosis and adequate treatment are essential in achieving the best outcome and avoiding serious sequelae. We describe a case of severe invasive PVL-SA infection in an infant. A literature review starting from 2010 was also performed in order to discuss clinical presentations, radiological findings, treatment and outcome.

Case presentation

This is a case of a 6-month-old boy who rapidly developed high fever and poor general condition. He was diagnosed as having multiple muscular abscesses, multiple foci of osteomyelitis and bloodstream infections caused by Panton-Valentine leukocidin Methicillin-resistant Staphylococcus aureus. He received intravenous antibiotics and surgical drainage of the abscess with progressive recovery.

Conclusion

Our report highlights the importance of improving awareness of this severe infection, as a prompt diagnosis and adequate manage is essential in order to save life and to prevent serious complications.

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

Chronic recurrent multifocal osteomyelitis (CRMO) is an auto-inflammatory disorder affecting the skeleton of children and adolescents. Whole-body MRI (WBMRI) is key in the diagnosis and follow-up of CRMO. Imaging protocols should include sagittal short Tau inversion recovery of the spine, imaging of the hands and feet, and T1 images for distinguishing normal bone marrow. CRMO lesions can be metaphyseal, epiphyseal and physeal-potentially causing growth disturbance and deformity. Spinal lesions are common, important and can cause vertebral collapse. Lesion patterns include multifocal tibial and pauci-focal patterns that follow a predictable presentation and course of disease. Common pitfalls of WBMRI include haematopoietic marrow signal, metaphyseal signal early on in bisphosphonate therapy and normal high T2 signal in the hands and feet. Pictorial reporting assists in recording lesions and follow-up over time. The purpose of this paper is to review the different WBMRI protocols, imaging findings, lesion patterns and common pitfalls in children with CRMO.

Findings in whole body MRI and conventional imaging in patients with fever of unknown origin-a retrospective study

Background

To analyse the influence of whole body (wb)-MRI on patient management compared to routine diagnostic tests in patients with fever of unknown origin (FUO).

Methods

Twenty-four patients with FUO, defined as illness of more than three weeks with fever greater than 38.3 °C, underwent wb-MRI at a 1.5 T MR-system. The MR-protocol consisted of the following sequences: axial T1 VIBE, coronal T2-TIRM and a coronal echoplanar diffusion weighted sequence (overall acquisition time 29:39 min:s). Furthermore, laboratory findings, chest-x-ray, abdominal ultrasound, CT-scans and/or PET-CT scans were evaluated and compared to the wb-MRI findings in regard to treatment changes.

Results

Wb-MRI yielded a correct diagnosis in 70% of the patients. In 46% the inflammatory focus was exclusively detected by wb-MRI. Focus detection by wb-MRI led to a subsequent change of the clinical management in 92% of the patients. In 6 patients both a wb-MRI and a PET-CT were performed yielding the correct diagnosis in the same 4 of 6 patients for both imaging modalities.

Conclusions

Wb-MRI appears to be of value in the evaluation of FUO patients, allowing for optimized treatment by increasing diagnostic certainty. Due to its lack of nephrotoxicity and ionizing radiation it may be preferred over standard imaging techniques and PET-CT in the future. However, given the low number of patients in our trial, further prospective studies have to be performed to confirm our results.

Whole-body magnetic resonance imaging in pediatric oncology - recommendations by the Oncology Task Force of the ESPR

The purpose of this recommendation of the Oncology Task Force of the European Society of Paediatric Radiology (ESPR) is to indicate reasonable applications of whole-body MRI in children with cancer and to address useful protocols to optimize workflow and diagnostic performance. Whole-body MRI as a radiation-free modality has been increasingly performed over the last two decades, and newer applications, as in screening of children with germ-line mutation cancer-related gene defects, are now widely accepted. We aim to provide a comprehensive outline of the diagnostic value for use in daily practice. Based on the results of our task force session in 2018 and the revision in 2019 during the ESPR meeting, we summarized our group's experiences in whole-body MRI. The lack of large evidence by clinical studies is challenging when focusing on a balanced view regarding the impact of whole-body MRI in pediatric oncology. Therefore, the final version of this recommendation was supported by the members of Oncology Task Force.

Whole-body magnetic resonance imaging: techniques and non-oncologic indications

Whole-body MRI is increasingly utilized for assessing oncologic and non-oncologic diseases in infants, children and adolescents. Focusing on the non-oncologic indications, this review covers technical elements required to perform whole-body MRI, the advantages and limitations of the technique, and protocol modifications tailored to specific indications. Rheumatologic diseases account for the majority of non-oncologic whole-body MRI performed in pediatric patients at the author's institution. Whole-body MRI helps in establishing the diagnosis, documenting disease extent and severity, and monitoring treatment response in enthesitis-related arthritis (ERA) and chronic recurrent multifocal osteomyelitis (CRMO). Other non-oncologic indications for whole-body MRI include osteomyelitis (usually pyogenic), pyrexia of unknown origin, neuromuscular disorders, inherited and inflammatory myopathies such as juvenile dermatomyositis and polymyositis, avascular necrosis, and fat/storage disorders. Use of whole-body MRI in postmortem imaging is rising, while whole-body MRI in non-accidental injury is considered to be of limited value. Imaging findings for a range of these indications are reviewed with whole-body MRI examples.

From imaging to reimbursement: what the pediatric radiologist needs to know about health care payers, documentation, coding and billing

Medical coding and billing processes in the United States are complex, cumbersome and poorly understood by radiologists. Despite the direct implications of radiology documentation on reimbursement, trainees and practicing radiologists typically receive limited relevant training. This article summarizes the payer structure including the state-based Children's Health Insurance Programs, discusses the essential processes by which radiologists request and receive reimbursement, details the mechanisms of coding diagnoses using International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes and imaging services using Current Procedural Terminology (CPT) and Healthcare Common Procedure Coding System (HCPCS) codes, and explores reimbursement and coding-related issues specific to pediatric radiology. Appropriate documentation, informed by knowledge of coding, billing and reimbursement fundamentals, facilitates appropriate payment for clinically relevant services provided by pediatric radiologists.

Pediatric Cancer Predisposition Imaging: Focus on Whole-Body MRI

The American Association for Cancer Research convened a meeting of international pediatric oncologists, geneticists, genetic counselors, and radiologists expert in childhood cancer predisposition syndromes (CPS) in October 2016 to propose consensus surveillance guidelines. Imaging plays a central role in surveillance for most, though not all, syndromes discussed. While encompassing the full gamut of modalities, there is increasing emphasis on use of nonionizing radiation imaging options such as magnetic resonance imaging (MRI) in children and adolescents, especially in the pediatric CPS population. In view of rapid evolution and widespread adoption of whole-body MRI (WBMRI), the purpose of our review is to address WBMRI in detail. We discuss its place in the surveillance of a range of pediatric CPS, the technical and logistical aspects of acquiring and interpreting these studies, and the inherent limitations of WBMRI. We also address issues associated with sedation and use of gadolinium-based contrast agents in MRI in children. Clin Cancer Res; 23(11); e6-e13. ©2017 AACRSee all articles in the online-only CCR Pediatric Oncology Series.

[Simultaneous whole-body PET-MRI in pediatric oncology : More than just reducing radiation?]

Diagnostic imaging plays an essential role in pediatric oncology with regard to diagnosis, therapy-planning, and the follow-up of solid tumors. The current imaging standard in pediatric oncology includes a variety of radiological and nuclear medicine imaging modalities depending on the specific tumor entity. The introduction of combined simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) has opened up new diagnostic options in pediatric oncology. This novel modality combines the excellent anatomical accuracy of MRI with the metabolic information of PET. In initial clinical studies, the technical feasibility and possible diagnostic advantages of combined PET-MRI have been in comparison with alternative imaging techniques. It was shown that a reduction in radiation exposure of up to 70 % is achievable compared with PET-CT. Furthermore, it has been shown that the number of imaging studies necessary can be markedly reduced using combined PET-MRI. Owing to its limited availability, combined PET-MRI is currently not used as a routine procedure. However, this new modality has the potential to become the imaging reference standard in pediatric oncology in the future. This review article summarizes the central aspects of pediatric oncological PET-MRI based on existing literature. Typical pediatric oncological PET-MRI cases are also presented.

An efficacy analysis of whole-body magnetic resonance imaging in the diagnosis and follow-up of polymyositis and dermatomyositis

OBJECTIVES

To evaluate the value of whole-body magnetic resonance imaging (WBMRI) in diagnosing muscular and extra muscular lesions in patients with polymyositis (PM) and dermatomyositis (DM).

METHODS

A retrospective analysis of WBMRI data from PM/DM patients who met the Bohan and Peter diagnostic criteria was performed. X2 test was used to compare the rate of positive diagnosis of newly diagnosed patients using WBMRI, serum creatine kinase test, and EMG. McNemar test was used to compare the performance of WBMRI and chest CT in detecting interstitial lung disease (ILD).

RESULTS

The study included 129 patients (30 PM cases and 99 DM cases). Of them, 81.4% (105/129) showed a visible inflammatory muscular edema on their WBMRI; 29.5% (38/129) had varying degrees of fatty infiltration (9 cases with clear muscular atrophy). Of the 66 newly diagnosed patients, the positive rates of WBMRI, muscle biopsy, serum creatine kinase test and EMG were 86.4% (57/66), 92.4% (61/66), 71.2% (47/66) and 71.1% (32/45), respectively. There was no significant difference in the positive rates between WBMRI and muscle biopsy (X2 = 1.28, P = 0.258). The WBMRI had a higher positive rate than both serum creatine kinase test (X2 = 4.53, P = 0.033) and EMG (X2 = 3.92, P = 0.047). In addition to muscular changes, WBMRI also detected interstitial lung disease (ILD) in 38 cases (29.5%), osteonecrosis in 15 cases (11.6%), and neoplastic lesions (5 malignant; 7 benign) in 12 cases (9.3%). Of the 61 patients who underwent routine chest CT examinations, the WBMRI and CT revealed ILD in 29 cases and 35 cases respectively. There was no significant difference in the sensitivity between WBMRI and CT (p = 0.146).

CONCLUSIONS

WBMRI is a sensitive, non-invasive and efficient imaging method. It comprehensively displays the extent of muscular involvement in PM/DM patients, and it has the ability to diagnose other associated extra muscular diseases, such as ILD and systemic malignancy. WBMRI can also help screen steroid-induced osteonecrosis.

Value of whole-body magnetic resonance imaging for screening multifocal osteonecrosis in patients with polymyositis/dermatomyositis

OBJECTIVE

To assess the value of coronal short-tau inversion recovery whole-body MRI (STIR-WBMRI) for screening osteonecrosis in patients with polymyositis (PM)/dermatomyositis (DM).

METHODS

The imaging and medical records of 129 patients with PM/DM who met the Bohan and Peter diagnostic criteria were retrospectively analyzed. STIR-WBMRI was performed in all patients. 18 patients had follow-up STIR-WBMRI. 12 patients underwent regional knee and/or hip MRI while 25 patients underwent radiography of the lower extremities.

RESULTS

STIR-WBMRI detected osteonecrosis in 15 (11.6%) patients. 38 joints were affected (mean, 2.5 per patient; range, 1-5 joints). Of the 38 joints affected by osteonecrosis, 33 had no clinical symptoms. Among the 12 patients who underwent regional MRI, STIR-WBMRI detected all 10 osteonecrotic sites seen on the regional MRI. The location, shape and size of the osteonecrotic lesions revealed on regional MRI were in accordance with those displayed on STIR-WBMRI. Of the 15 patients with osteonecrosis, 6 performed routine radiography of the affected joints and revealed no osteonecrotic lesions. Follow-up WBMRI detected new osteonecrosis in two patients whose first WBMRI revealed that there was no osteonecrosis in any skeleton.

CONCLUSION

In addition to displaying muscle inflammation, STIR-WBMRI can efficiently detect early multifocal osteonecrosis in the whole bodies of patients with PM/DM. Advances in knowledge: In patients with PM/DM, WBMRI which takes 12-15 min can display muscular involvement and detect early multisite osteonecrosis in the whole body at the same time. Osteonecrotic lesions revealed by WBMRI are in accordance with those displayed on regional WBMRI.

Whole-body MRI in pediatric patients with cancer

Cancer is the leading cause of natural death in the pediatric populations of developed countries, yet cure rates are greater than 70% when a cancer is diagnosed in its early stages. Recent advances in magnetic resonance imaging methods have markedly improved diagnostic and therapeutic approaches, while avoiding the risks of ionizing radiation that are associated with most conventional radiological methods, such as computed tomography and positron emission tomography/computed tomography. The advent of whole-body magnetic resonance imaging in association with the development of metabolic- and function-based techniques has led to the use of whole-body magnetic resonance imaging for the screening, diagnosis, staging, response assessment, and post-therapeutic follow-up of children with solid sporadic tumours or those with related genetic syndromes. Here, the advantages, techniques, indications, and limitations of whole-body magnetic resonance imaging in the management of pediatric oncology patients are presented.

Pediatric whole-body MRI: A review of current imaging techniques and clinical applications

There are many congenital, neoplastic, inflammatory, and infectious processes in the pediatric patient for which whole-body imaging may be of benefit diagnostically and prognostically. With recent improvements in magnetic resonance imaging (MRI) hardware and software and resultant dramatically reduced scan times, imaging of the whole body with MRI has become a much more practicable technique in children. Whole-body MRI can provide a high level of soft tissue and skeletal detail while avoiding the exposure to ionizing radiation inherent to computed tomography and nuclear medicine imaging techniques. This article reviews the more common current whole-body MRI techniques in children and the primary pathologies for which this imaging modality may be most useful to the radiologists and referring clinicians. J. MAGN. RESON. IMAGING 2016;44:783-793.

Whole-body MRI: non-oncological applications in paediatrics

Whole-body magnetic resonance imaging (WBMRI) is a fast and accurate method for detecting and monitoring of diseases throughout the entire body without exposure to ionizing radiation. Among emerging non-oncological potential applications of WBMRI, rheumatological diseases play an important role. Rheumatological WBMRI applications include the evaluation of chronic multifocal recurrent osteomyelitis, dermatomyositis, fever of unknown origin, arthritis, and connective tissue diseases. Aim of this review is to give an overview of the use of WBMRI in rheumatological field.

Whole-body MRI in paediatric oncology

Imaging plays a crucial role in the diagnosis and follow-up of paediatric malignancies. Until recently, computed tomography (CT) has been the imaging technique of choice in children with cancer, but nowadays there is an increasing interest in the use of functional imaging techniques like positron emission tomography and single-photon emission tomography. These later techniques are often combined with CT allowing for simultaneous acquisition of image data on the biological behaviour of tumour, as well as the anatomical localisation and extent of tumour spread. Because of the small but not negligible risk of radiation induced secondary cancers and the significantly improved overall survival rates of children with cancer, there is an increasing interest in the use of alternative imaging techniques that do not use ionising radiation. Magnetic resonance imaging (MRI) is a radiation-free imaging tool that allows for acquiring images with a high spatial resolution and excellent soft tissue contrast throughout the body. Moreover, recent technological advances have resulted in fast diagnostic sequences for whole-body MR imaging (WB-MRI), including functional techniques such as diffusion weighted imaging. In this review, the current status of the technique and major clinical applications of WB-MRI in children with cancer will be discussed.

A semiflexible 64-channel receive-only phased array for pediatric body MRI at 3T

PURPOSE

To design, construct, and validate a semiflexible 64-channel receive-only phased array for pediatric body MRI at 3T.

METHODS

A 64-channel receive-only phased array was developed and constructed. The designed flexible coil can easily conform to different patient sizes with nonoverlapping coil elements in the transverse plane. It can cover a field of view of up to 44 × 28 cm(2) and removes the need for coil repositioning for body MRI patients with multiple clinical concerns. The 64-channel coil was compared with a 32-channel standard coil for signal-to-noise ratio and parallel imaging performances on different phantoms. With IRB approval and informed consent/assent, the designed coil was validated on 21 consecutive pediatric patients.

RESULTS

The pediatric coil provided higher signal-to-noise ratio than the standard coil on different phantoms, with the averaged signal-to-noise ratio gain at least 23% over a depth of 7 cm along the cross-section of phantoms. It also achieved better parallel imaging performance under moderate acceleration factors. Good image quality (average score 4.6 out of 5) was achieved using the developed pediatric coil in the clinical studies.

CONCLUSION

A 64-channel semiflexible receive-only phased array has been developed and validated to facilitate high quality pediatric body MRI at 3T. Magn Reson Med 76:1015-1021, 2016. © 2015 Wiley Periodicals, Inc.

Whole-body magnetic resonance imaging in children: state of the art

Whole-body imaging in children was classically performed with radiography, positron-emission tomography, either combined or not with computed tomography, the latter with the disadvantage of exposure to ionizing radiation. Whole-body magnetic resonance imaging (MRI), in association with the recently developed metabolic and functional techniques such as diffusion-weighted imaging, has brought the advantage of a comprehensive evaluation of pediatric patients without the risks inherent to ionizing radiation usually present in other conventional imaging methods. It is a rapid and sensitive method, particularly in pediatrics, for detecting and monitoring multifocal lesions in the body as a whole. In pediatrics, it is utilized for both oncologic and non-oncologic indications such as screening and diagnosis of tumors in patients with genetic syndromes, evaluation of disease extent and staging, evaluation of therapeutic response and post-therapy follow-up, evaluation of non neoplastic diseases such as multifocal osteomyelitis, vascular malformations and syndromes affecting multiple regions of the body. The present review was aimed at describing the major indications of whole-body MRI in pediatrics added of technical considerations.

Whole-body MRI as an unconventional diagnostic tool in a pediatric patient with systemic infection

Anaplasma phagocytophilum, an obligate intracellular bacterium, is the causative agent of human granulocytic anaplasmosis (HGA), a tickborne infection usually manifesting as fever, malaise, cytopenia, spleen enlargement, and hepatitis. Herein, we report a case of a 14-year-old girl with HGA whose whole-body magnetic resonance imaging (MRI) disclosed an unusual picture characterized by small, widespread punctuate millimetric nodules, hypointense on T1-weighted and hyperintense on STIR sequences. This firstly reported finding may represent an alternative tool for identifying atypical infectious diseases.

Non-contrast-enhanced whole-body magnetic resonance imaging in the general population: the incidence of abnormal findings in patients 50 years old and younger compared to older subjects

Purpose

To assess and compare the incidence of abnormal findings detected during non-contrast-enhanced whole-body magnetic resonance imaging (WB-MRI) in the general population in two age groups: (1) 50 years old and younger; and (2) over 50 years old.

Materials and Methods

The analysis included 666 non-contrast-enhanced WB-MRIs performed on a 1.5-T scanner between December 2009 and June 2013 in a private hospital in 451 patients 50 years old and younger and 215 patients over 50 years old. The following images were obtained: T2-STIR (whole body-coronal plane), T2-STIR (whole spine-sagittal), T2-TSE with fat-saturation (neck and trunk-axial), T2-FLAIR (head-axial), 3D T1-GRE (thorax-coronal, axial), T2-TSE (abdomen-axial), chemical shift (abdomen-axial). Detected abnormalities were classified as: insignificant (type I), potentially significant, requiring medical attention (type II), significant, requiring treatment (type III).

Results

There were 3375 incidental findings depicted in 659 (98.9%) subjects: 2997 type I lesions (88.8%), 363 type II lesions (10.8%) and 15 type III lesions (0.4%), including malignant or possibly malignant lesions in seven subjects. The most differences in the prevalence of abnormalities on WB-MRI between patients 50 years old and younger and over 50 years old concerned: brain infarction (22.2%, 45.0% respectively), thyroid cysts/nodules (8.7%, 18.8%), pulmonary nodules (5.0%, 16.2%), significant degenerative disease of the spine (23.3%, 44.5%), extra-spinal degenerative disease (22.4%, 61.1%), hepatic steatosis (15.8%, 24.9%), liver cysts/hemangiomas (24%, 34.5%), renal cysts (16.9%, 40.6%), prostate enlargement (5.1% of males, 34.2% of males), uterine fibroids (16.3% of females, 37.9% of females).

Conclusions

Incidental findings were detected in almost all of the subjects. WB-MRI demonstrated that the prevalence of the vast majority of abnormalities increases with age.

Simultaneous whole-body PET/MR imaging in comparison to PET/CT in pediatric oncology: initial results

PURPOSE

To compare positron emission tomography (PET)/magnetic resonance (MR) imaging and PET/computed tomography (CT) for lesion detection and interpretation, quantification of fluorine 18 ((18)F) fluorodeoxyglucose (FDG) uptake, and accuracy of MR-based PET attenuation correction in pediatric patients with solid tumors. Materials and Methods This prospective study had local ethics committee and German Federal Institute for Drugs and Medical Devices approval. Written informed consent was obtained from all patients and legal guardians. Twenty whole-body (18)F-FDG PET/CT and (18)F-FDG PET/MR examinations were performed in 18 pediatric patients (median age, 14 years; range, 11-17 years). (18)F-FDG PET/CT and (18)F-FDG PET/MR data were acquired sequentially on the same day for all patients. PET standardized uptake values (SUVs) were quantified with volume of interest measurements in lesions and healthy tissues. MR-based PET attenuation correction was compared with CT-derived attenuation maps (µ-maps). Lesion detection was assessed with separate reading of PET/CT and PET/MR data. Estimates of radiation dose were derived from the applied doses of (18)F-FDG and CT protocol parameters. Descriptive statistical analyses were performed to report correlation coefficients and relative deviations for comparison of SUVs, rates of lesion detection, and percentage reductions in radiation dose.

RESULTS

PET SUVs showed strong correlations between PET of PET/CT (PETCT) and PET of PET/MR (PETMR) (r > 0.85 for most tissues). Apart from drawbacks of MR-based PET attenuation correction in osseous structures and lungs, similar SUVs were found on PET images corrected with CT-based µ-maps (13.1% deviation of SUVs for bone marrow and <5% deviation for other tissues). Lesion detection rate with PET/MR imaging was equivalent to that with PET/CT (61 areas of focal uptake on PETMR images vs 62 areas on PETCT images). Advantages of PET/MR were observed especially in soft-tissue regions. Furthermore, PET/MR offered significant dose reduction (73%) compared with PET/CT.

CONCLUSION

Pediatric oncologic PET/MR is technically feasible, showing satisfactory performance for PET quantification with SUVs similar to those of PET/CT. Compared with PET/CT, PET/MR demonstrates equivalent lesion detection rates while offering markedly reduced radiation exposure. Thus, PET/MR is a promising modality for the clinical work-up of pediatric malignancies. Online supplemental material is available for this article.

Widespread osteonecrosis in children with leukemia revealed by whole-body MRI

BACKGROUND

Confirmation of early long-bone epiphyseal osteonecrosis in pediatric patients with leukemia allows for medical and surgical intervention before articular surface collapse. MRI detects early osteonecrosis, but multiple focused MR images are required to capture all lesions.

QUESTIONS/PURPOSES

We determined whether whole-body MRI (WB-MRI) could (1) assist in diagnosing long-bone epiphyseal and other osteonecroses, (2) characterize articular surface involvement, and (3) detect preferential sites for osteonecrosis.

PATIENTS AND METHODS

We retrospectively reviewed prospectively collected data on all 11 pediatric patients newly diagnosed with leukemia who had musculoskeletal pain develop that persisted 4 weeks or more during leukemia treatment. All were screened for osteonecrosis by WB-MRI, which consisted of a one-time scan of the entire body. Osteonecrosis was defined as circumscribed lesions with a distinct rim of low signal intensity in the normally high-intensity marrow on T1-weighted images and high signal intensity in the normally low-intensity marrow on short-tau inversion recovery images.

RESULTS

WB-MRI confirmed osteonecrosis in nine of 11 patients. All patients had multisite lesions; eight had long-bone epiphyseal lesions, which comprised 66 of 129 (51%) of all lesions. Osteonecrosis involving greater than 50% of the epiphyseal surface was present in 57% of distal femoral and proximal tibial lesions. All humeral and femoral head lesions involved more than 1/3 of the medial surface volume but were asymptomatic. No articular collapse was present. All osteonecrotic lesions were more common in the lower extremities.

CONCLUSIONS

WB-MRI confirmed early epiphyseal osteonecrosis, with quantification of articular surface involvement. Lower limbs were preferentially affected, but asymptomatic humeral head osteonecrosis was present in five of nine patients.

LEVEL OF EVIDENCE

Level IV, diagnostic study. See Instructions for Authors for a complete description of levels of evidence.

Oncological imaging: tumor surveillance in children

As the need for accurate diagnostic imaging often continues throughout a cancer survivor's life, imaging methods with the least toxicity must be used so as to provide needed information without contributing to long-term sequelae that might compound toxicities inherent with the primary disease and its treatment. In this regard, the costs, benefits and potential risks of post-therapy monitoring for disease recurrence warrant periodic review. Unfortunately, few analyses are available regarding the impact of surveillance imaging on the detection of disease recurrence, salvage rates of relapse disease and long-term survival outcomes for pediatric cancer survivors. This review will examine the role and limitations of surveillance imaging in pediatric oncology.

The future of pediatric US

Despite advances in other modalities, US remains an essential technology in pediatric imaging. Improvements in technology provide increasingly detailed anatomical images, and new techniques show promise in providing novel anatomical as well as physiological and structural information. Other specialties are recognizing the value of US to their patients and are increasingly performing their own examinations. Economic and social factors are also influencing the development and use of US. This review will evaluate many of these issues and demonstrate that the future of pediatric US is bright and that pediatric radiologists can and should continue to be leaders in its use and development.

Detection of multifocal osteonecrosis in an adolescent with dermatomyositis using whole-body MRI

Osteonecrosis is a well-recognized complication of corticosteroid use resulting in significant morbidity, often requiring surgical intervention. Whole-body MRI is a promising method that allows imaging of the whole patient in a reasonable time without the use of ionizing radiation. This technique has the potential for evaluating nonmalignant multifocal skeletal disease like osteonecrosis. This case highlights the value of whole-body MR in an adolescent with dermatomyositis who developed multifocal osteonecrosis.