Review of standard paediatric neuroradiology MRI protocols from 12 UK tertiary paediatric hospitals: is there much variation between centres?

AIM

To investigate how magnetic resonance imaging (MRI) examinations are protocolled in tertiary paediatric neuroradiology centres around the UK for some of the more common presentations encountered in paediatric neuroradiology, and to identify any variations of note.

MATERIALS AND METHODS

All 19 UK tertiary paediatric neuroradiology centres registered with the British Society of Neuroradiologists-Paediatric Group were contacted and asked if they could provide a copy of their standard MRI protocols. Twelve responded (63%) and 10 of the more common presentations were selected and the standard acquired sequences obtained at each participating centre were compared. Where available the collated protocols were also compared against current published guidance.

RESULTS

The basic sequences carried out by centres around the UK are similar; however, there are lots of variations overall. The only standardised protocol currently being implemented nationally in paediatric imaging is that for brain tumours. Otherwise, chosen protocols are generally dependent on the preferences and technical capabilities of individual centres. Suggested published protocols also exist for non-accidental injury (NAI), multiple sclerosis, epilepsy, and head and neck imaging.

CONCLUSIONS

The differences in MRI protocolling depend in part on technical capabilities and in part on the experience and preferences of the paediatric neuroradiologists at each centre. For most presentations, there is no consensus as to what constitutes the perfect protocol. The present results will be useful for specialist centres who may wish to review their current protocols, and for more generalist centres to use as a reference to guide their MRI protocolling.

Electron beam evaporation of superconductor-ferromagnet heterostructures

We report on the electronic and magnetic properties of superconductor-ferromagnet heterostructures fabricated by electron beam evaporation on to unheated thermally oxidised Si substrates. Polycrystalline Nb thin films (5 to 50 nm thick) were shown to possess reliably high superconducting critical temperatures (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_{c}$$\end{document}Tc), which correlate well with the residual resistivity ratio (RRR) of the film. These properties improved during ex-situ annealing, resulting in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\Delta }T_{c}$$\end{document}ΔTc and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\Delta }$$\end{document}ΔRRR increases of up 2.2 K (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim$$\end{document}∼ 40% of the pre-annealed \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_{c}$$\end{document}Tc) and 0.8 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim$$\end{document}∼ 60% of the pre-annealed RRR) respectively. Nb/Pt/Co/Pt heterostructures showed substantial perpendicular anisotropy in the ultrathin limit (≤ 2.5 nm), even in the extreme limit of Pt(0.8 nm)/Co(1 nm)/Pt(0.6 nm). These results point to the use of electron beam evaporation as route to line-of-sight deposited, low-thickness, high quality Nb-based superspintronic multilayers.

T2 prolongation in the cerebellar vermis on prenatal MRI of fetuses with Chiari 2 malformations

AIM

To describe a new finding in fetuses with Chiari 2 malformations recognised at in utero (iu) magnetic resonance imaging (MRI), specifically T2 prolongation (high signal) in the cerebellar vermis.

MATERIALS AND METHODS

This was a prospective observational study of iuMRI studies performed at two time points on 20 fetuses with Chiari 2 malformations and 10 control fetuses at the same time points. High T2 signal in the cerebellar vermis was noted and correlated with posterior fossa dimensions was assessed.

RESULTS

High T2 signal in the cerebellar vermis was found in over half of the fetuses with a Chiari 2 malformation, but was not correlated with the degree of reduction in size of the bony posterior fossa.

CONCLUSION

The present findings suggest that abnormal high T2 signal in the cerebellum is common in fetuses with Chiari 2 malformations and although the cause of the signal change is not known at present it may represent vasogenic oedema as a result of restricted venous drainage.

A pictorial review of imaging in paediatric stroke

Stroke is recognised as an important disease in adults. Paediatric stroke is less understood, yet still an important cause of morbidity and mortality, with an incidence of 5 per 100 000 children and is one of the top 10 leading causes of death in children. In adults the vast majority of strokes are ischaemic, whereas in children haemorrhage makes up half the cases. The incidence of neonatal stroke is much higher, at up to 45 per 100 000 population; however, the underlying causes are less understood. This paper acts as a guide to the different causes of stroke with the key differences on imaging discussed.

Paediatric post-septal and pre-septal cellulitis: 10 years' experience at a tertiary-level children's hospital

OBJECTIVE

To assess the incidence and complications of pre-septal (pre-SC) and post-septal (post-SC) cellulitis over 10 years. Pre-SC and post-SC are also known as periorbital and orbital cellulitis, respectively.

METHODS

Retrospective analysis of CT scans. Data included the presence of pre-SC and post-SC, paranasal sinus disease (PNS) and complications.

RESULTS

Among 125 patients scanned for these suspected diagnoses, 67 had both pre-SC and post-SC, 37 had pre-SC and 4 had post-SC; there were 17 normal scans. 110 patients had PNS. 68/71 (96%) patients with post-SC had PNS. Post-SC complications included orbital and/or subperiosteal abscess (50/71: 30 medial orbital, 10 superomedial, 3 lateral, 2 anteromedial, 2 inferomedial, 1 superior, 1 anterosuperior and 1 not specified), cavernous sinus thrombosis (CST) (1), superior ophthalmic vein (SOV) thrombosis (4) and subdural frontal empyema (2); 1 patient had SOV and CST and subdural empyema.

CONCLUSION

71/125 (57%) patients had post-SC. 50/125 (40%) patients imaged for pre-SC/post-SC had orbital abscess; 44/50 (88%) of these involved the medial orbit. Patients can develop solely superior or inferior abscesses that are difficult to identify by axial imaging alone, hence coronal reformatted imaging is essential. 5/125 (4%) patients developed major complications (SOV/CST/empyema), hence imaging review of the head and cavernous sinus region is essential. A diagnosis of post-SC on CT should alert the radiologist because this diagnosis can be associated with an increased incidence (5/71, 7%) of complications.

ADVANCES IN KNOWLEDGE

We recommend that all patients with a suspected diagnosis of post-SC should undergo CT scan (post-contrast orbits and post-contrast head, with multiplanar reformats and a careful review of the SOV and the cavernous sinus). Particular attention should be paid to exclude intracranial complications including subdural empyema and cerebral abscess. As soon as a diagnosis of post-SC is made, in addition to informing the referring clinical team, urgent opinion should be sought from ear, nose and throat (ENT), neurology and ophthalmology with a view to urgently drain of the paranasal sinuses`.

CT of the neonatal head

Computed tomography (CT) is used less often than other techniques on neonatal units. However, in the acute setting, CT can be invaluable in diagnosing or excluding potentially life-threatening conditions and guiding initial management in neonates. Common indications for scanning include trauma, suspected non-accidental injury, infection, or an acute hypoxic or metabolic event. The aim of this review is to provide an overview of the normal neonatal head at CT and compare this to the common pathological abnormalities. Several key features of each condition will be highlighted. It is important to note that some pathological conditions can have overlapping features at CT and, therefore, the clinical history and additional investigations are also of key importance in determining the diagnosis.

Neuro-ophthalmological Complications of Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) can lead to prominent nerve hypertrophy, which can mimic other forms of neuropathy radiologically. Neuro-ophthalmological complications can also occur in CIDP, either at presentation or chronically in the disorder. This can also cause diagnostic difficulties. We report three cases of neuro-ophthalmological complications of CIDP: two cases of papilloedema and one case of proptosis. In all three cases cranial nerve hypertrophy was present. CIDP should be considered in neuro-ophthalmological presentations associated with cranial/spinal nerve root hypertrophy.

Management of isolated syringomyelia in the paediatric population--a review of imaging and follow-up in a single centre

OBJECTIVE

To assess the natural history of isolated syringomyelia in children.

METHODS

MRI reports from February 2007 to August 2011 mentioning syrinx were identified on Sheffield Children's PACS database. Scans with syringes having an AP diameter of > 1 mm and extending over at least two vertebral bodies were reviewed. Patients with an identifiable cause such as a Chiari malformation were then excluded.

RESULTS

Thirty-nine patients were included with a mean age at diagnosis of 10.6 years. The average syrinx AP diameter was 3.30 mm. The rostrocaudal length of the syringes varied between 2 and 19 vertebral bodies. Twenty-seven out of 39 syringes were thoracic in origin. There were 3 and 6 syringes involving the cervicothoracic and thoracolumbar regions, respectively, with 3 involving the cervical area only. Eleven out of 39 (Group I) patients were found "incidentally" during work-up for adolescent idiopathic scoliosis and these were considered as a separate group. These patients did not have any significant symptoms and were discharged following their scoliosis correction surgery. Syrinx was incidental in 14 further patients (Group II). Of the 14 patients, 11 remained asymptomatic with no change in syrinx morphology throughout follow up. Of the 14 patients, 3 were lost to follow-up. Of the 39 patients, 14 (Group III) presented with progressive back pain without any obvious clinical cause. Of the 14, 10 either improved or remained the same. Of the 14 patients, 3 underwent lumbar puncture, 1/14 having myelography. All 4/14 patients reported significant pain reduction on follow up following intervention.

CONCLUSION

Idiopathic syrinx is a benign pathology, which can be managed expectantly. Most cases remain stable or improve over time. In a small minority who have progressive back pain, we have found that lumbar puncture may be helpful in reducing symptoms.

3.0 T MRI of 2000 consecutive patients with localisation-related epilepsy

OBJECTIVES

Clinical guidelines suggest that all patients diagnosed with localised seizures should be investigated with MRI to identify any epileptogenic structural lesions, as these patients may benefit from surgical resection. There is growing impetus to use higher field strength scanners to image such patients, as some evidence suggests that they improve detection rates. We set out to review the detection rate of radiological abnormalities found by imaging patients with localised seizures using a high-resolution 3.0 T epilepsy protocol.

METHODS

Data were reviewed from 2000 consecutive adult patients with localisation-related epilepsy referred between January 2005 and February 2011, and imaged at 3.0 T using a standard epilepsy protocol.

RESULTS

An abnormality likely to be related to seizure activity was identified in 403/2000 (20.2%) patients, with mesial temporal sclerosis diagnosed in 211 patients. 313/2000 (15.6%) had lesions potentially amenable to surgery. Abnormalities thought unrelated to seizure activity were found in 324/2000 (16.1%), with 8.9% having evidence of ischaemic disease.

CONCLUSIONS

Since the introduction of the then National Institute for Clinical Excellence guidelines in 2004, the detection rate of significant pathology using a dedicated 3.0 T epilepsy protocol has not fallen, despite the increased numbers of patients being imaged. This is the largest study of epilepsy imaging at 3.0 T to date and highlights the detection rates of significant pathology in a clinical setting using a high-strength magnet. The prevalence of ischaemic disease in this population is significantly higher than first thought, and may not be incidental, as is often reported.

The encephalopathic child

Encephalopathy is a common paediatric emergency associated with a high risk of morbidity, mortality and long term neurodevelopmental delay in survivors. Prompt diagnosis of the cause of encephalopathy enables the paediatrician to deliver specific medical or surgical treatment that will facilitate a better short and long term outcome. Diagnostic imaging plays a pivotal role in diagnosis. Encephalopathy has many causes. The differential diagnosis includes non accidental injury, trauma, metabolic syndromes, meningo-encephalitis, toxins, hypoxia, demyelination, stroke, haemorrhage and tumours. We describe an approach that helps us formulate an imaging strategy using US, CT and MRI that facilitates patient care.

Implementation of a patient-orientated pharmacy service

In 1994, the clinical pharmacy service at Harefield hospital was reorganised: the inpatient population was divided into five groups based on the directorate system and each group allocated to a pharmacist. Each pharmacist became responsible for the provision of a clinical pharmacy service to their group of patients, irrespective of the ward on which the patients were resident. This was a major change from the previous system where pharmacists visited a number of wards and saw all the patients on those wards. The effect of the reorganisation on pharmacists' activities, customers' satisfaction, pharmacists' job satisfaction and the supply of inpatient medication was measured. The change had minimal impact on the majority of parameters measured but significantly increased the time taken by pharmacists to carry out their rounds. The extra time commitment may be justified by the opportunities this method of organisation offers for the development of total pharmaceutical care.

Junior doctors' satisfaction with the ward pharmacy service in the Hammersmith and Queen Charlotte's special health authority

A questionnaire was drawn up to ascertain junior doctors' satisfaction with the ward pharmacy service in the Hammersmith and Queen Charlotte's special health authority, London. The questionnaire was designed for face to face interviews lasting not more than 10 minutes. The interviews were taped and the interviewer was not known to the doctors. The survey took place in January, 1992. Forty three out of 135 senior house officers, registrars and senior registrars employed by the special health authority were randomly selected for interview and 26 (60 per cent) of these were seen. Eighty five per cent of doctors thought the service was better than average and most doctors were satisfied with aspects of the service such as prescription monitoring, advice received from and friendliness of ward pharmacists. Only one doctor rated the service as worse than that in other hospitals in which he had worked. Fifteen doctors suggested increased liaison or contact between ward pharmacists and doctors would make the service better. A number of issues have been raised concerning the service which have been addressed and we intend to repeat the survey in the future.

Does a high workload decrease ward pharmacists' clinical monitoring?

In Britain prescriptions are written on proforma charts kept by the patient's bed. Pharmacists generally visit wards daily to initiate supply of drugs and monitor prescription charts. We wished to compare this service across all acute hospitals in a British regional health authority.

Pharmacists (n=210) at 31 hospitals monitored 10,337 beds in 489 wards. The median beds/pharmacist ratio was 57 (first quartile 33, third quartile 68). The median time to check 100 prescription charts was 2 hours 49 minutes (first quartile 2 hours 21 minutes, third quartile 3 hours 27 minutes) and related to the ward specialty (Spearman's rs=0.78, P=0.013). Analysis of the 19 district general hospitals showed a positive correlation between time to monitor 100 beds and prescription monitoring incidents (PMIs)/100 beds/week (P=0.002) and a negative correlation between beds/pharmacist and PMIs/100 beds/week (P=0.003). Increasing a ward pharmacist's workload may lead to a decrease in their monitoring of appropriate prescribing. It is suggested that these measures may have some value as indicators of workload, clinical effectiveness and efficiency.

Low Grade Gliomas. Can We Predict Tumour Behaviour from Imaging Features?

Low grade gliomas (WHO grade II) are diffuse, infiltrative glial tumours of the brain. The low grade glioma group includes a number of entities, namely diffuse astrocytoma, oligodendroglioma and oligoastrocytoma. This group of the low-grade gliomas share certain common issues of behaviour, clinical assessment and management. Even though these tumours are termed low grade they are not to be considered “benign”: untreated they are invariably fatal. They may remain “stable” for many years and hence a “watch and wait” treatment policy is often adopted. Unfortunately some tumours progress more rapidly than others with dedifferentiation into high grade tumours which become rapidly fatal. Based on standard imaging criteria it has been difficult to predict which of these low grade gliomas will progress more rapidly. Treatment decisions would benefit from some prediction as to which tumours are likely to progress more rapidly than others. This review will discuss some of the imaging features that may help to predict which low grade gliomas will progress more rapidly than others. Such imaging features include the rate of growth on serial imaging; the morphological features that parallel genetic markers; the assessment and change of tumour vascular status as assessed by MR perfusion imaging and tumour characteristics on PET and MR spectroscopy.

Predicting the rate of physician-accepted interventions by hospital pharmacists in the United Kingdom

Pharmacists' clinical interventions in a group of British hospitals were counted, and a model to determine factors that affected the intervention rate was developed. All pharmacists who visited patient wards in 27 acute care hospitals recorded their daily ward visits and their clinical interventions during five consecutive days (Monday through Friday) in June 1993. An intervention was defined as any recommendation made with the intent of changing drug treatment. Mixed-model Poisson regression was used to try to explain variations in the intervention rate, defined as the number of physician-accepted interventions divided by the number of occupied-bed days. Possible predictors of intervention rate considered were characteristics of the hospitals, the wards, and the pharmacists. During the study period, 248 pharmacists visited 10,478 beds and proposed 3,501 interventions. Of these interventions, 3371 were accepted, 56 were rejected, and 74 were unresolved. The most frequent reasons for the interventions involved the dose (29%), the need for therapy (21%), the choice of drug (14%), and the route (12%). Ward type, pharmacist grade, and the total time the pharmacist spent on the wards were significant predictors of the intervention rate. To validate the model, data were collected during the same period in 1994; the model predicted the number of interventions within 1 of the actual number in 82% of cases. In a model explaining the factors that affected the rate of physician-accepted pharmacist interventions in acute care hospitals in the United Kingdom, ward type, pharmacist grade, and total time spent on the ward by the pharmacist were significant predictors of the intervention rate.

What a drag it is getting cold: partitioning the physical and physiological effects of temperature on fish swimming

The influence of temperature-induced changes in water viscosity on the swimming performance and kinematics of larval Atlantic herring (Clupea harengus) was examined using high-speed video recording. The physical effects of viscosity were measured separately from the physiological (Q10) effects of temperature by increasing the viscosity using methyl cellulose. Voluntary swimming speeds of large larvae (18.2 mm total length) were characterized by Reynolds numbers based on length (ReL) between 100 and 500 and varied with temperature and viscosity. Speeds of small larvae (9.6 mm) at ReL between 25 and 125 were strongly affected by viscosity, but virtually unaffected by temperature at equal viscosities. Speeds of large larvae were modulated by transverse tail speed. Small (viscosity-dominated) larvae altered both transverse tail speed and tail amplitude to vary their swimming speed. Stride lengths for both sizes of larvae followed predictions for viscous-regime swimming until ReL>450. The combined data suggest that the viscous hydrodynamic regime for larval herring extends to at least ReL=300 and that viscosity could be important up to ReL of approximately 450. Because the physical effects of viscosity supplement the physiological effects of temperature on locomotor performance (when ReL is below approximately 300), indices such as Q10 can greatly overestimate the dependence of physiological processes on temperature, as demonstrated by an example.

Ward pharmacy: a foundation for prescribing audit?

OBJECTIVES

To determine the extent and nature of prescription monitoring incidents by hospital pharmacists and to derive a performance indicator to allow prescription monitoring to be compared among hospitals in North West Thames region.

DESIGN

Survey of all self recorded prescription monitoring incidents for one week in June 1990.

SETTING

All (31) acute hospitals in the region with pharmacy departments on site, covering 10,337 beds.

SUBJECTS

210 pharmacists.

MAIN MEASURES

Number of prescription monitoring incidents recorded, their nature, and outcome; a performance indicator of prescription monitoring (incidents/100 beds/week) and its variation according to specialty and site.

RESULTS

3273 prescription monitoring incidents were recorded (median 89 per hospital, range 3-301), the most common being related to the dose and frequency of administration of the drug (933 incidents, 29%). These incidents led to alterations of prescriptions on 1611 occasions; the pharmacist's advice was rejected on 81. The greatest number of prescription monitoring incidents/100 beds/week by specialty was recorded for intensive therapy units (median 75); the medians for medicine and surgery were 32 and 21 respectively. This performance indicator varied 20-fold when analysed by site, values ranging from 3.6 to 82.1 (median 29.8).

CONCLUSIONS

Hospital pharmacists play a large part in monitoring and improving prescribing, and most of their interventions are related to the basics of prescribing. They therefore have a role in medical audit, working with clinicians to identify prescribing problems, and to set standards and monitor practice. A performance indicator of prescription monitoring incidents/100 beds/week allows comparison of pharmacists' activities among sites and may be a valuable tool in auditing them.