Applying machine learning classifiers to automate quality assessment of paediatric dynamic susceptibility contrast (DSC-) MRI data

OBJECTIVE

Investigate the performance of qualitative review (QR) for assessing dynamic susceptibility contrast (DSC-) MRI data quality in paediatric normal brain and develop an automated alternative to QR.

METHODS

1027 signal-time courses were assessed by Reviewer 1 using QR. 243 were additionally assessed by Reviewer 2 and % disagreements and Cohen's κ (κ) were calculated. The signal drop-to-noise ratio (SDNR), root mean square error (RMSE), full width half maximum (FWHM) and percentage signal recovery (PSR) were calculated for the 1027 signal-time courses. Data quality thresholds for each measure were determined using QR results. The measures and QR results trained machine learning classifiers. Sensitivity, specificity, precision, classification error and area under the curve from a receiver operating characteristic curve were calculated for each threshold and classifier.

RESULTS

Comparing reviewers gave 7% disagreements and κ = 0.83. Data quality thresholds of: 7.6 for SDNR; 0.019 for RMSE; 3 s and 19 s for FWHM; and 42.9 and 130.4% for PSR were produced. SDNR gave the best sensitivity, specificity, precision, classification error and area under the curve values of 0.86, 0.86, 0.93, 14.2% and 0.83. Random forest was the best machine learning classifier, giving sensitivity, specificity, precision, classification error and area under the curve of 0.94, 0.83, 0.93, 9.3% and 0.89.

CONCLUSION

The reviewers showed good agreement. Machine learning classifiers trained on signal-time course measures and QR can assess quality. Combining multiple measures reduces misclassification.

ADVANCES IN KNOWLEDGE

A new automated quality control method was developed, which trained machine learning classifiers using QR results.

Dynamic susceptibility-contrast magnetic resonance imaging with contrast agent leakage correction aids in predicting grade in pediatric brain tumours: a multicenter study

BACKGROUND

Relative cerebral blood volume (rCBV) measured using dynamic susceptibility-contrast MRI can differentiate between low- and high-grade pediatric brain tumors. Multicenter studies are required for translation into clinical practice.

OBJECTIVE

We compared leakage-corrected dynamic susceptibility-contrast MRI perfusion parameters acquired at multiple centers in low- and high-grade pediatric brain tumors.

MATERIALS AND METHODS

Eighty-five pediatric patients underwent pre-treatment dynamic susceptibility-contrast MRI scans at four centers. MRI protocols were variable. We analyzed data using the Boxerman leakage-correction method producing pixel-by-pixel estimates of leakage-uncorrected (rCBVuncorr) and corrected (rCBVcorr) relative cerebral blood volume, and the leakage parameter, K2. Histological diagnoses were obtained. Tumors were classified by high-grade tumor. We compared whole-tumor median perfusion parameters between low- and high-grade tumors and across tumor types.

RESULTS

Forty tumors were classified as low grade, 45 as high grade. Mean whole-tumor median rCBVuncorr was higher in high-grade tumors than low-grade tumors (mean ± standard deviation [SD] = 2.37±2.61 vs. -0.14±5.55; P<0.01). Average median rCBV increased following leakage correction (2.54±1.63 vs. 1.68±1.36; P=0.010), remaining higher in high-grade tumors than low grade-tumors. Low-grade tumors, particularly pilocytic astrocytomas, showed T1-dominant leakage effects; high-grade tumors showed T2*-dominance (mean K2=0.017±0.049 vs. 0.002±0.017). Parameters varied with tumor type but not center. Median rCBVuncorr was higher (mean = 1.49 vs. 0.49; P=0.015) and K2 lower (mean = 0.005 vs. 0.016; P=0.013) in children who received a pre-bolus of contrast agent compared to those who did not. Leakage correction removed the difference.

CONCLUSION

Dynamic susceptibility-contrast MRI acquired at multiple centers helped distinguish between children's brain tumors. Relative cerebral blood volume was significantly higher in high-grade compared to low-grade tumors and differed among common tumor types. Vessel leakage correction is required to provide accurate rCBV, particularly in low-grade enhancing tumors.

Combining multi-site magnetic resonance imaging with machine learning predicts survival in pediatric brain tumors

Brain tumors represent the highest cause of mortality in the pediatric oncological population. Diagnosis is commonly performed with magnetic resonance imaging. Survival biomarkers are challenging to identify due to the relatively low numbers of individual tumor types. 69 children with biopsy-confirmed brain tumors were recruited into this study. All participants had perfusion and diffusion weighted imaging performed at diagnosis. Imaging data were processed using conventional methods, and a Bayesian survival analysis performed. Unsupervised and supervised machine learning were performed with the survival features, to determine novel sub-groups related to survival. Sub-group analysis was undertaken to understand differences in imaging features. Survival analysis showed that a combination of diffusion and perfusion imaging were able to determine two novel sub-groups of brain tumors with different survival characteristics (p < 0.01), which were subsequently classified with high accuracy (98%) by a neural network. Analysis of high-grade tumors showed a marked difference in survival (p = 0.029) between the two clusters with high risk and low risk imaging features. This study has developed a novel model of survival for pediatric brain tumors. Tumor perfusion plays a key role in determining survival and should be considered as a high priority for future imaging protocols.

Classification of paediatric brain tumours by diffusion weighted imaging and machine learning

To determine if apparent diffusion coefficients (ADC) can discriminate between posterior fossa brain tumours on a multicentre basis. A total of 124 paediatric patients with posterior fossa tumours (including 55 Medulloblastomas, 36 Pilocytic Astrocytomas and 26 Ependymomas) were scanned using diffusion weighted imaging across 12 different hospitals using a total of 18 different scanners. Apparent diffusion coefficient maps were produced and histogram data was extracted from tumour regions of interest. Total histograms and histogram metrics (mean, variance, skew, kurtosis and 10th, 20th and 50th quantiles) were used as data input for classifiers with accuracy determined by tenfold cross validation. Mean ADC values from the tumour regions of interest differed between tumour types, (ANOVA P < 0.001). A cut off value for mean ADC between Ependymomas and Medulloblastomas was found to be of 0.984 × 10⁻³ mm² s⁻¹ with sensitivity 80.8% and specificity 80.0%. Overall classification for the ADC histogram metrics were 85% using Naïve Bayes and 84% for Random Forest classifiers. The most commonly occurring posterior fossa paediatric brain tumours can be classified using Apparent Diffusion Coefficient histogram values to a high accuracy on a multicentre basis.

IMG-06. PREDICTING SURVIVAL FROM PERFUSION AND DIFFUSION MRI BY MACHINE LEARNING

INTRODUCTION

Magnetic Resonance Imaging (MRI) is routinely used in the assessment of children’s brain tumours. Reduced diffusion and increased perfusion on MRI are commonly associated with higher grade but there is a lack of quantitative data linking these parameters to survival. Machine learning is increasingly being used to develop diagnostic tools but its use in survival analysis is rare. In this study we combine quantitative parameters from diffusion and perfusion MRI with machine learning to develop a model of survival for paediatric brain tumours. METHOD: 69 children from 4 centres (Birmingham, Liverpool, Nottingham, Newcastle) underwent MRI with diffusion and perfusion (dynamic susceptibility contrast) at diagnosis. Images were processed to form ADC, cerebral blood volume (CBV) and vessel leakage correction (K2) parameter maps. Parameter mean, standard deviation and heterogeneity measures (skewness and kurtosis) were calculated from tumour and whole brain and used in iterative Bayesian survival analysis. The features selected were used for k-means clustering and differences in survival between clusters assessed by Kaplan-Meier and Cox-regression.

RESULTS

Bayesian analysis revealed the 5 top features determining survival to be tumour volume, ADC kurtosis, CBV mean, K2 mean and whole brain CBV mean. K-means clustering using these features showed two distinct clusters (high- and low-risk) which bore significantly different survival characteristics (Hazard Ratio = 5.6).

DISCUSSION AND CONCLUSION

Diffusion and perfusion MRI can be used to aid the prediction of survival in children’s brain tumours. Tumour perfusion played a particularly important role in predicting survival despite being less routinely measured than diffusion.

Utilising functional imaging to predict survival in paediatric brain tumours

Introduction

Brain tumours are a common cause of death in the paediatric population. We have previously shown that MR imaging and spectroscopy can be used to non-invasively differentiate between tumour types. Here, we demonstrate that functional imaging can be highly predictive of survival and grade in a paediatric cohort.

Methods

Perfusion (PWI) and diffusion weighted imaging (DWI) were performed in a multi-site (Birmingham Children’s Hospital, Royal Victoria Infirmary, Alder Hey, Nottingham) cohort ([grade, 5-year survival alive:dead number] = [I,15:1],[II, 5:1],[III,2:3],[IV,8:11]). ROIs were drawn on T2 imaging and functional imaging features (mean, standard deviation, skewness, and kurtosis) were derived. Supervised machine learning was used to predict 5-year survival and tumour grade from features. ANOVA and post-hoc tests were used to assess differences in features between grade and 5-year survival status.

Results

5-year survival was predicted with 89%, 85%, and 87% accuracy with all imaging, perfusion, or diffusion features, respectively.

A significant difference in perfusion was found between surviving and diseased participants (1.71 ± 0.82 vs 2.62 ± 1 mL/100g/min, respectively, p < 0.05). A significant difference in ADC (mm2 s-1) between tumour grades was found (1 vs 4 (1533 ± 458 vs 857 ± 239), 4 vs 3 (857 ± 239 vs 1197 ± 137), 4 vs 2 (857 ± 239 vs 1440 ± 557), corrected p < 0.05).

Conclusion

We have shown that perfusion and diffusion imaging features can be used to non-invasively assess tumour grade and estimate 5-year survival status in a cohort of paediatric brain tumours.

Multicentre study of perfusion magnetic resonance imaging in paediatric brain tumours

Studies in adults have shown that brain tumour perfusion correlates with grade. These studies are dominated by gliomas grade II to IV which are rare in children. The standard method, Dynamic Susceptibility Contrast MRI, provides estimates of relative cerebral blood volume (rCBV) but contrast agent leakage affects rCBV accuracy. The majority of perfusion studies have been conducted at single centres and variation in acquisition protocols makes the generalizability of results questionable. The aim of this study was to compare leakage-corrected rCBV with grade in paediatric brain tumours at multiple centres. Scans were analysed from 85 patients at 4 centres on 6 scanners prior to treatment. MRI protocols varied between centres. Histological diagnoses including grade were obtained. Whole-tumour median rCBV was significantly higher in the 45 high grade than the 40 low grade tumours (2.54 ± 1.63 ml/100ml vs 1.68 ± 1.36 ml/100ml, p=0.010). Low grade tumours, particularly pilocytic astrocytomas (grade I), displayed more contrast agent leakage consistent with their appearance on contrast enhanced images and required more leakage correction than high grade tumours. This finding differs from that in adults where contrast agent uptake is usually associated with higher grade. A cut-off of 1.70 ml/100ml for rCBV gave sensitivity and specificity of 76% and 65% respectively for discriminating grade. In summary, perfusion MRI can be used to help distinguish between low and high grade paediatric brain tumours. This finding is robust across multiple centres and acquisition protocols but correction should be made for leakage of contrast agent from the vessels.

The impact of intraoperative magnetic resonance in routine pediatric neurosurgical practice-a 6-year appraisal

BACKGROUND

The intraoperative magnetic resonance scanner (ioMR) was introduced in our unit in 2009, and has been used routinely since then.

OBJECTIVE

This study aims to describe indications, radiological features, and clinical outcomes of the patients operated on with ioMRI and analyze our experience.

METHODS

A retrospective analysis of a prospective surgical database has been performed, including surgical procedure, intent, radiological reports, need for second-look surgery, and complications, supplemented by further review of the clinical notes and the scans.

RESULTS

From 2009 to 2015, 255 surgical procedures with ioMR were performed: 175 were craniotomies for tumor excision, 65 were epilepsy related, and 15 were biopsies or cyst drainages. The mean age was 9.4 years. One ioMR was performed in 79.5% patients; the mean duration of the MR was 41 min. In 172 cases (67.4%), no actions followed the ioMR. When the aim of the surgery was debulking of the tumor, the percentage of patients in which the ioMR was followed by resection was higher than when complete resection was the aim (56 vs 27.5%). The complication rate was not increased when compared with our previous results (infection 1%, neurological deficits 12%).

CONCLUSION

This is the largest published series of ioMRI-aided pediatric neurosurgery to date. We have demonstrated that it can be used safely and routinely in pediatric neurosurgical procedures at any age, assisting the surgeon in achieving the best extent of resection and aiding in intra-operative decision-making for tumor- and non-tumor-related intracranial pathology.

Management of paediatric high-grade blunt renal trauma: a 10-year single-centre UK experience

OBJECTIVE

To report the management and outcome of paediatric patients sustaining high-grade blunt renal trauma.

PATIENTS AND METHODS

Medical records were examined for all American Association for the Surgery of Trauma (AAST) grade III-V blunt renal trauma cases admitted to a paediatric trauma centre from 2005 to 2015. Data collected and analysed included: demographics, imaging modalities, management, length of hospital stay (LOS), complications, and follow-up outcomes.

RESULTS

In all, 18 children (12 boys, six girls) with mean (range) age 11 (4-15) years were included. According to the AAST grading criteria, 39% (seven of 18) of the patients had grade III, 50% (nine of 18) grade IV, and 11% (two of 18) grade V injuries; 44% (eight of 18) had concomitant injuries. Most of the patients were managed conservatively (89%, 16 of 18), although two of the 16 subsequently needed JJ-stent insertion during inpatient stay for symptomatic urinoma(s). In all, 11% (two of 18) of the patients required interventional radiology service(s), involving selective embolisation for life-threatening renal tract haemorrhage. Blood transfusion for renal injury exclusively was required in 11% (two of 18) of the patients. In all, 89% (16 of 18) of the patients had at least one follow-up imaging study before hospital discharge; most (13 of 16) had ultrasonography and three required computed tomography. The median (range) LOS was 11 (4-31) days. In all, 17% (three of 18) of the patients required hospital re-admission within 30 days for complications and all required interventional procedures: JJ stent for urinoma (one), embolisation of renal arterio-venous fistula (one), and embolisation for a post-traumatic pseudoaneurysm (one). Overall, the median (range) follow-up was 6 (2-60) months. In all, 78% (14 of 18) of the patients had dimercaptosuccinic acid studies, with 11 showing reductions in renal function (range 3-44%).

CONCLUSIONS

This study supports a care pathway strategy advocating conservative management of high-grade renal injuries in children. However, patients may experience a relative decline in renal function with higher grade injuries indicating the need for monitoring and follow-up.

Quantitative measurement of blood flow in paediatric brain tumours-a comparative study of dynamic susceptibility contrast and multi time-point arterial spin labelled MRI

Objective:

Arterial spin-labelling (ASL) MRI uses intrinsic blood water to quantify the cerebral blood flow (CBF), removing the need for the injection of a gadolinium-based contrast agent used for conventional perfusion imaging such as dynamic susceptibility contrast (DSC). Owing to the non-invasive nature of the technique, ASL is an attractive option for use in paediatric patients. This work compared DSC and multi-timepoint ASL measures of CBF in paediatric brain tumours.

Methods:

Patients (n = 23; 20 low-grade tumours and 3 high-grade tumours) had DSC and multi-timepoint ASL with and without vascular crushers (VC). VC removes the contribution from larger vessel blood flow. Mean perfusion metrics were extracted from control and T₁-enhanced tumour regions of interest (ROIs): arterial arrival time (AAT) and CBF from the ASL images with and without VC, relative cerebral blood flow (rCBF), relative cerebral blood volume, delay time (DT) and mean transit time (MTT) from the DSC images.

Results:

Significant correlations existed for: AAT and DT (r = 0.77, p = 0.0002) and CBF and rCBF (r = 0.56, p = 0.02) in control ROIs for ASL-noVC. No significant correlations existed between DSC and ASL measures in the tumour region. Significant differences between control and tumour ROI were found for MTT (p < 0.001) and rCBF (p < 0.005) measures.

Conclusion:

Significant correlations between ASL-noVC and DSC measures in the normal brain suggest that DSC is most sensitive to macrovascular blood flow. The absence of significant correlations within the tumour ROI suggests that ASL is sensitive to different physiological mechanisms compared with DSC measures.

Advances in knowledge:

ASL provides information which is comparable with that of DSC in healthy tissues, but appears to reflect a different physiology in tumour tissues.

Radiation doses from fluoroscopically guided cardiac catheterization procedures in children and young adults in the United Kingdom: a multicentre study

OBJECTIVE

To gather data on radiation doses from fluoroscopically guided cardiac catheterization procedures in patients aged under 22 years at multiple centres and over a prolonged period in the UK. To evaluate and explain variation in doses. To estimate patient-specific organ doses and allow for possible future epidemiological analysis of associated cancer risks.

METHODS

Patient-specific data including kerma area product and screening times from 10,257 procedures carried out on 7726 patients at 3 UK hospitals from 1994 until 2013 were collected. Organ doses were estimated from these data using a dedicated dosimetry system based on Monte Carlo computer simulations.

RESULTS

Radiation doses from these procedures have fallen significantly over the past two decades. The organs receiving the highest doses per procedure were the lungs (median across whole cohort, 20.5 mSv), heart (19.7 mSv) and breasts (13.1 mSv). Median cumulative doses, taking into account multiple procedures, were 23.2, 22.2 and 16.7 mSv for these organs, respectively. Bone marrow doses were relatively low (median per procedure, 3.2 mSv; cumulative, 3.6 mSv).

CONCLUSION

Most modern cardiac catheterizations in children are moderately low-dose procedures. Technological advances appear to be the single most important factor in the fall in doses. Patients undergoing heart transplants undergo the most procedures. An epidemiological assessment of cancer risks following these procedures may be possible, especially using older data when doses were higher.

ADVANCES IN KNOWLEDGE

This is the first large-scale, patient-specific assessment of organ doses from these procedures in a young population.

Diffusion abnormalities on intraoperative magnetic resonance imaging as an early predictor for the risk of posterior fossa syndrome

BACKGROUND

Posterior fossa syndrome (PFS) is an important complication of posterior fossa surgery in children. The pathophysiology of this condition remains unclear, but there is evidence implicating surgical injury of the proximal efferent cerebellar pathway (pECP) and the cerebellar vermis to PFS. We aimed to evaluate if diffusion abnormalities involving these structures on the final intraoperative MRI can predict the development of PFS.

METHODS

Diffusion-weighted imaging from 31 posterior fossa resections were anonymized and evaluated for abnormalities involving the dentate nucleus, superior cerebellar peduncle, and the mesencephalic tegmentum forming the pECP, vermis, and middle cerebellar peduncle. The case notes were independently evaluated for evidence of PFS.

RESULTS

The diffusion imaging in 28 cases was of optimal quality for evaluation. Diffusion abnormalities were identified in 10 cases, 7 of which involved the pECP. Retrospective evaluation revealed evidence of PFS in 6 cases. There was a significant association between abnormalities involving pECP structures (P = .001) and development of PFS. Bilateral involvement of pECP (P = .006) was a highly specific risk factor for predicting the development of PFS. Diffusion abnormality of the inferior vermis was significantly associated with PFS (P = .001) but may not represent a risk factor in isolation.

CONCLUSION

This study demonstrates the feasibility of identifying children at risk for developing PFS at the earliest stage post tumor resection and thus adds to the growing evidence base on its pathophysiology.

Spontaneous spinal epidural haematoma mimicking meningitis in a 2-year-old child--a case report and literature review

INTRODUCTION

We report the case of a 2-year-old boy with suspected meningitis who presented with acute onset neck pain and stiffness associated with right-sided weakness and ataxia.

MANAGEMENT

Despite intravenous antibiotics and antiviral treatment, his condition deteriorated. Magnetic resonance imaging demonstrated spontaneous cervical epidural haematoma (C4-C7) extending down to thoracic (T7) level with associated compression of the spinal cord. He was treated successfully by neurosurgical decompression and made a complete recovery.

DISCUSSION

Spinal epidural haematoma is a neurosurgical emergency characterised by extravasation of blood in the spinal epidural space. The clinical presentation particularly in young children can masquerade other conditions such as meningitis. In this article, we discuss our case and review the literature on spontaneous spinal epidural hematoma with an aim to improve awareness of this condition which if not recognised and treated early can lead to significant lifelong morbidity.

High field strength magnetic resonance imaging in paediatric brain tumour surgery--its role in prevention of early repeat resections

PURPOSE

The purpose of this study is to compare the surgical and imaging outcome in children who underwent brain tumour surgery with intention of complete tumour resection, prior to and following the start of intra-operative MRI (ioMRI) service.

METHODS

ioMRI service for brain tumour resection commenced in October 2009. A cohort of patients operated between June 2007 and September 2009 with a pre-surgical intention of complete tumour resection were selected (Group A). A similar number of consecutive cases were selected from a prospective database of patients undergoing ioMRI (Group B). The demographics, imaging, pathology and surgical outcome of both groups were compared.

RESULTS

Thirty-six of 47 cases from Group A met the inclusion criterion and 36 cases were selected from Group B; 7 of the 36 cases in Group A had unequivocal evidence of residual tumour on the post-operative scan; 5 (14%) of them underwent repeat resection within 6 months post-surgery. In Group B, ioMRI revealed unequivocal evidence of residual tumour in 11 of the 36 cases following initial resection. In 10 of these 11 cases, repeat resections were performed during the same surgical episode and none of these 11 cases required repeat surgery in the following 6 months. Early repeat resection rate was significantly different between both groups (p = 0.003).

CONCLUSION

Following the advent of ioMRI at our institution, the need for repeat resection within 6 months has been prevented in cases where ioMRI revealed unequivocal evidence of residual tumour.

Anaplastic ependymoma with sclerotic bone metastases

Ependymomas are glial central nervous system (CNS) tumors that arise from the ependymal layer of brain and spinal cord. These are heterogeneous group of tumors with varied histopathological features and prognosis. They frequently relapse at the primary site and may disseminate to other CNS sites. Extraneural metastases are, however, extremely rare. We present a case of ependymoma in a child with widespread metastasis to her bones, a previously unreported event.

Improving head growth in preterm infants--a randomised controlled trial II: MRI and developmental outcomes in the first year

BACKGROUND

Very preterm infants are at risk of poor growth and neurodevelopmental outcome. Illness and difficulties overcoming the challenges of feeding these infants often lead to undernutrition in the first few weeks.

OBJECTIVE

To explore the relationships between early nutrition, post-natal head growth, quantitative magnetic resonance imaging (MRI) and developmental outcome in the first year among infants born before 29 weeks' gestation.

DESIGN

Infants born before 29 weeks' gestation were randomised to receive hyperalimented or standard feeding regimen from birth to 34 weeks' postmenstrual age (PMA). The primary outcome was occipitofrontal circumference (OFC) at 36 weeks' OFC. Quantitative MRI was performed at 40 weeks' PMA. Developmental assessment using Bayley Scales of Infant Development II (BSID II) was carried out at 3 and 9 months post-term.

RESULTS

109 infants survived to the end of the first year PMA. 65 infants underwent MRI scan. 81 and 71 infants were seen at 3 and 9 months post-term. Quantitative MRI findings, mental development index (MDI) and psychomotor development index (PDI) were not statistically different between the two groups. Total brain volume (TBV) at 40 weeks' PMA, MDI and PDI at 3 months post-term correlated significantly with energy deficit at 28 days of age

CONCLUSIONS

Improving early energy deficit in very preterm infants may promote brain growth. Quantitative MRI may have a role to play in predicting developmental outcome. Post-natal growth at 36 weeks' PMA and quantitative MRI finding at 40 weeks' PMA appear to be closely related to mental outcomes in the first year.

TRIAL REGISTRATION NUMBER

ISRCTN 19509258.

Hemimyelomeningocele: a rare and complex spinal dysraphism

We report a case of hemimyelomeningocele. This is a rare spinal dysraphism, consisting of the association of a split cord malformation with myelomeningocele. MRI demonstrates division of the spinal cord into two hemicords which are separated by a bony spur. The left hemicord forms a myelomeningocele, thus resulting in a hemimyelomeningocele. Accurate and early diagnosis of spinal dysraphisms is essential for optimal, individualised neurosurgical treatment.

TIPIT: a randomised controlled trial of thyroxine in preterm infants under 28 weeks gestation: magnetic resonance imaging and magnetic resonance angiography protocol

Background

Infants born at extreme prematurity are at high risk of developmental disability. A major risk factor for disability is having a low level of thyroid hormone described as hypothyroxinaemia, which is recognised to be a frequent phenomenon in these infants. Derangements of critical thyroid function during the sensitive window in prematurity when early development occurs, may have a range of long term effects for brain development. Further research in preterm infants using neuroimaging techniques will increase our understanding of the specificity of the effects of hypothyroxinaemia on the developing foetal brain. This is an explanatory double blinded randomised controlled trial which is aimed to assess the effect of thyroid hormone supplementation on brain size, key brain structures, extent of myelination, white matter integrity and vessel morphology, somatic growth and the hypothalamic-pituitary-adrenal axis.

Methods

The study is a multi-centred double blinded randomised controlled trial of thyroid hormone supplementation in babies born below 28 weeks' gestation. All infants will receive either levothyroxine or placebo until 32 weeks corrected gestational age. The primary outcomes will be width of the sub-arachnoid space measured using cranial ultrasound and head circumference at 36 weeks corrected gestational age. The secondary outcomes will be thyroid hormone concentrations, the hypothalamic pituitary axis status and auxological data between birth and expected date of delivery; thyroid gland volume, brain size, volumes of key brain structures, extent of myelination and brain vessel morphology at expected date of delivery and markers of morbidity which include duration of mechanical ventilation and/or oxygen requirement and chronic lung disease.

Trial registration

Current Controlled Trials ISRCTN89493983

Unsuspected periventricular leukomalacia in children with strabismus: a case series

PURPOSE

We report a case series of seven patients who presented with strabismus and no apparent known neurological deficit.

METHODS

A retrospective review of notes was performed on all patients presenting at the Royal Liverpool Children's Hospital (Alder Hey) with strabismus, in whom subsequent investigation revealed the presence of periventricular leukomalacia (PVL).

RESULTS

All seven patients presented with esotropia. One patient also had dissociated vertical deviation. A history of premature birth was elicited in six cases; however, one patient had been born at 42 weeks. Apparently uncomplicated routine surgery produced unexpectedly poor results.

CONCLUSIONS

Patients with undiagnosed PVL may present to the ophthalmologist with strabismus and no other apparent neurological abnormality. Where it is suspected that the patient may have suffered a significant hypoxic-ischaemic event, the ophthalmologist should have a low threshold for investigating with magnetic resonance imaging, particularly if the patient shows unexpected outcomes following appropriate treatment. Patients and parents should be counselled on possible suboptimal results prior to the offer of surgical correction of strabismus.

Immediate care of school sport injury

School sport is a major cause of injury in the post-primary age group. The importance of primary prevention in sport has been identified; however secondary prevention of school related sport injury has not been described in Ireland. A random sample of 450 schools in Northern Ireland and the Republic of Ireland was studied using a postal questionnaire. Current management of sport injury, with particular interest in the expertise and training of teachers and coaches, was explored. Replies were received from 333 (74%) schools. There was no physical education teacher with up to date first aid training in 37% schools. Immediate care in terms of mechanisms and equipment to deal with injury was available in 35%-81% of schools responding. Correct response ranged from 65%-90% to four scenarios: commonly presenting yet potentially serious management problems. This study demonstrated deficiencies in sport injury care. In addition to concern about current training, a need for basic life support training is highlighted. These findings have implications for the prevention of school sports injuries.

Impact of school sports injury

BACKGROUND

Most injuries in school occur during sport.

OBJECTIVES

To explore the impact of sports injury in supervised school sport.

METHOD

A prospective study of sports injury in children of secondary school age presenting to the accident and emergency department. Each patient was identified on registration, matched with medical records after discharge, and contacted later by telephone to complete a structured interview. Patients were only included if their injury was sustained during supervised school sport.

RESULTS

During the study period, 194 patients aged 11-18 attended the accident and emergency department with an injury, 51% of which occurred during school sport. Injuries occurred most commonly in rugby (43%), followed by physical education and games together (17.5%). Most injuries were x rayed (72%). Just over 12% of pupils lost no time from sport, most (71%) were back to sport within three weeks, and 2.7% were injured for more than eight weeks. Almost a third of parents needed to take time off from work to deal with the injured child.

CONCLUSION

School sports injuries are important. They account for just over half of all injuries in secondary school children. They cause significant disruption to school and sport and have important implications for the wider family.

Sports medicine and the accident and emergency medicine specialist

BACKGROUND

Sport and exercise related injuries are responsible for about 5% of the workload in the accident and emergency (A&E) department, yet training in sports medicine is not a compulsory part of the curriculum for Higher Specialist Training.

AIM

To determine how A&E medicine consultants and specialist trainees view their role and skill requirements in relation to sports medicine.

METHOD

A modified Delphi study, consisting of two rounds of a postal questionnaire. Participants were invited to rate the importance of statements relating to the role and training of the A&E specialist in relation to sports injuries (six statements) and the need for knowledge and understanding of defined skills of importance in sports medicine (16 statements). VALUE OF RESEARCH: This provides a consensus of opinion on issues in sport and exercise medicine that have educational implications for A&E specialists, and should be considered in the curriculum for Higher Specialist Training. There is also the potential for improving the health care provision of A&E departments, to the exercising and sporting population.

Validation of electrode placement in neonatal electrogastrography

Electrogastrography (EGG) is the transcutaneous measurement of gastric electrical activity. The aims of this study were to validate the electrode placement position in neonatal electrogastrography using ultrasonography to localise the stomach, and to describe the observed EGG frequency characteristics. Fifteen neonates with no known abdominal disorder were studied. Two bipolar EGG recordings were obtained from each subject, the first from electrodes placed at sites localized by ultrasound and the second from electrodes placed at the currently recommended sites. Paired sample t tests were used to compare electrode positioning and electrogastrographic data. There were 15 subjects with a mean age of 36 days (range 1-95). While there was a significant difference in the position of electrodes at each site, the EGG recordings did not differ. The 3-cycle/minute (2.6-3.7cpm) activity ranged from 30% to 84% of recorded time (mean at sites localized with ultrasound was 53%, and at currently recommended sites it was 50%; difference not significant, P = 0.155). Bradygastria (<2.6 cpm) was observed in the range of 2-29% of recorded time (mean at sites localised with ultrasound was 12.9%, and at currently recommended sites it was 11.7%; difference not significant, P = 0.40). Tachygastria (3.2-10 cpm) was shown to be in the range of 10-58% of recorded time (mean at sites localized with ultrasound was 33.3%, and at currently recommended sites it was 38.7%; difference not significant; P = 0.044). In conclusion, there was no significant difference between EGG recordings taken from electrode sites localized by ultrasound and those recommended by manufacturers of the electrogastrogram, thus confirming the validity of the manufacturer's recommended electrode positioning. The pattern of electrical control activity in the normal neonatal stomach appears to be different from that demonstrated in adults. Bradygastria and tachygastria are seen more frequently, with fewer periods of 3 cpm activity.

Torsion of an ovarian cyst mimicking enteric duplication cyst on transabdominal ultrasound: two cases

We describe two girls with abdominal cysts which demonstrated the "double wall" or "muscular rim" sign. On the basis of this, the diagnosis of duplication cyst was made in each case. At surgery, both were found to have ovarian cysts, and histology revealed prominent haemorrhage within the cyst wall. To our knowledge, there has been no previous report of a false-positive "double wall sign".

Myositis ossificans complicating severe Guillain-Barré syndrome

We report myositis ossificans occurring in a 13-year-old boy with severe and rapidly progressive Guillain-Barré syndrome. This complication should be considered when severe musculoskeletal pain is experienced by such patients. Disodium etidronate may be of benefit in this condition.

Downgaze paresis following severe head trauma in a child

A 4 1/2-year-old girl developed a downgaze paresis following severe head trauma. Magnetic resonance imaging showed evidence of peri-aqueductal lesions in the rostral midbrain in the region of the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF). Twenty five weeks following the injury, the downgaze paresis remained unchanged but she developed convergence retraction nystagmus on attempted upgaze. Repeat imaging did not show any change in the lesions in the rostral midbrain. This report provides further evidence for the riMLF in the control of downgaze, and a synkinesis is postulated for the development of the convergence retraction nystagmus.