BSPR 2006 Abstracts
THE BRITISH SOCIETY OF PAEDIATRIC RADIOLOGY
ANNUAL SCIENTIFIC MEETING 2006
Right Upper Quadrant Cysts in Children – A diagnostic Dilemma
S. Avula, Y. Jones, L. Abernehty, D. Pilling. Royal Liverpool Children’s NHS Trust
Cystic Lesions in the right upper quadrant of the abdomen in infants can cause diagnostic difficulties, especially those that are located close to the hepatic hilum and the duodenum. In particular, the differentiation of duplication cysts and choledochal cysts may be problematic. We present the imaging findings of cases which illustrate the features of duplication cysts and choledochal cysts which are the main differential diagnoses for this clinical scenario. Ultrasound is the primary modality of imaging. Radio-isotope HIDA and MRI scans may be helpful in difficult areas.
Pre-operative Imaging Assessment for Suitability for Rex Shunt – An Initial Experience.
E. Hoey, T. Humphrey, D. Kessel, M.D. Stringer*, H. Woodley, Department of Radiology and Children’s Liver and GI Unit. St James’s Univerity Hospital, Leeds.
Background: Extrahepatic portal vein obstruction typically causes severe portal hypertension. The meso-portal bypass (Rex shunt) is a relatively new surgical technique that restores hepatopetal blood flow and corrects portal hypertension. We review our experience of imaging in the preoperative assessment of children who are potential candidates for this procedure.
Method: A Combination of ultrasound, gadolinium enhanced MRI of the liver and retrograde hepatic venography have been used in the pre-operative work up. Two key imaging features are essential criteria for surgery: a patent splenic/superior mesenteric vein (portal) confluence and a patent intrahepatic left portal vein. The radiology of each patient was reviewed to assess which imaging modalities were correctly able to identify the patency of these vessels.
Results: Since 2001, 16 children have been referred for assessment of these 11 had formal USS, 25 MRI and 7 hepatic venography. Five children were rejected for Rex shunt on the bvasis of unfavourable vascular anatomy on imaging (4) or after surgical exploration (1). Eleven Rex shunts were carried out successful. In these children 7 were assessed by USS which identified a patent portal confluence in 5 and patent left intrahepatic portal vein in 6; 10 children were assessed by MRI which identified a patent portal confluence in 10 and a patent left intrahepatic portal vein in 9; and 4 were assessed by hepatic venography which demonstrated a patent left intrahepatic portal vein in 4 but did not show the portal confluence.
Conclusion: Retrograde hepatic venography is the investigation of choice to define the left intrahepatic portal vein and its umbilical segment in the Rex recess of the liver. Our imaging styrategy has evolved with progressive experience and currently we assess all patients with USS and MRI, proceeding to hepatic venographt only when the vascular anatomy is uncertain.
Solitary Liver Cysts in Children: Are they Always so Simple?
H.E. Woodley*, T.N. Rogers, W.G. Ramsden*, J.I. Wyatt**, M.D. Stringer Children’s Liver and GI Unit, Departments of Radiology’ and Histopathology** St. James’s University Hospital, Leeds.
Aim: Liver cysts in children are uncommon. Many are simple and solitary and do not require intervention. However, this study demonstrates the broad range of potential pathologies, some of which are life-threatening.
Method: All children referred to our unit during an 8 year period (1998-2005) and found to have a liver cyst were prospectively recorded. Clinical, radiological and pathologic features were analyzed. Children with an isolated extrahepatic choledochal cyst were excluded.
Results: Twenty-one children with a liver cyst were identified. Two of these had undergone unsuccessful surgical intervention prior to referral. There were 11 prenatally detected cysts. Median gestational age at detection was 22 (19-35) weeks; only one was specifically characterised as a liver cyst prenatally, Six of these required major surgery: 2 large simple cysts, 2 intrahepatic choledochal cysts, 1 giant complex biliary cyst causing respiratory distress and 1 ciliated hepatic foregut cyst. Four of the 5 cysts remaining under ultrasound surveillance have decreased in size or resolved.
In 10 children presenting between birth and 15.8 years, a liver cyst was diagnosied postnatally: 3 huge cystic mesenchymal hamatomas, 1 type V choledochal cyst, 1 hydatid cyst and 5 simple cysts. Four of these required surgical resection.
Simple cysts tended to be small and could be distinguished from other pathologies using a combination of imaging techniques (ultrasound, MRI/MRCP, radionuclide scan). Only 2 of the 12 children with ‘simple’ cysts in this series required surgery for symptoms. However, a wide range of other cyst pathologies were found in 9 children and although none was malignant some were life-threatening and most required resection.
Conclusions: ‘Simple’ liver cysts rarely cause symptoms or require surgey but the radiologist should be aware of the range of other types of liver cysts some of which require referral to a paediatric surgeon with hepatobiliary expertise for appropriate treatment.
When Calomine Lotion Fails
S. Mackenzie, R. Shuklar, M Zagurova, D. Grier. Bristol Children’s Hospital
Chicken pox is a common usually mild childhood ailment. This is a presentation of the investigations and findings in 13 out of the 46 patients admitted to Bristol Children’s Hospital with the diagnosis of chickenpox over a two year span (June 2004-June 2006).
The presentation will highlight the protean manifestations of rare complications especially of the musculoskeletal system and the benefits of investigation by MRI.
Comparison of Differential Renal Functions using 99 mtc-DMSA and 99mtc-MAG3 Isotope Renography in a Paediatric Population
G. Ritchie, A.G. Wilkiunson, C. Graham. Royal Hospital for Sick Children, Edinburgh
Aim: To determine if there is a difference in differential renal function (DRF) using 99mTc-DMSA and 999mTc-MAG3 isotope studies.
Method: We retrospectively identified 100 consecutive patients who had undergone both DMSA and MAG3 scans. The imaging and patient data were reviewed to obtain information as to age, diagnosis, previous evidence of reflux or scarring, renal pelvis diameter on ultrasound, time to half counts on MAG3 scan and diuretic administration. The DRF obtained from DMSA and MAG 3 was compared statistically.
Results: Paired t test: there is no statistically significant difference in the results of the two tests. DMSA-MAG3 difference is 0.61 (%) with a 95% C1 of (-0.22, 1.45), p-value=148
Analysis of variance: renal pelvis diameter was broken into 4 groups, <10, 10-20, 20-40 and >40 with 65%, 15%, 15% and 5% respectively. There is no evidence of a statistically significant difference in groups (p=0.46).
Conclusion: There is no evidence of a statistically significant difference in the estimation of DRF using DMSA and MAG3 scans. If a MAG3 scan has been performed to assess drainage or reflux, a DMSA scan to assess differential function is unnecessary. Change of our practice will result in considerable savings in time, cost and radiation burden.
Long-Term Sequelae of Radiation Exposure due to CT in Childhood – A Proposed Study
M.S. Pearce. Newcastle University
While computed tomography (CT) plays an important role in the diagnosis and management of disease and injury, the long-term risks of CT are unknown. Children represent a susceptible group for radiation-related cancer. The proposed study provides a unique opportunity to assess the safety of CT scans in children and to gain more information on a potentially important risk factor for cancer in children and young adults.
We will collect detailed electronic information on 200,000 patients (<18 years) scanned using CT prior to 1998. This information, including radiological, clinical and demographic details, will be downloaded from the information systems in radiology units across the UK and linked with the National Health Service Central Registry so that cancer and morality information can be obtained Patient Information Advisory Group approval will be sought to negate the need for individual consent.
A cohort analysis of all 200,000 patients will assess cancer risk in relation to a radiation dose estimated by an expert dosimetrist. A nested case-control study will involve the abstraction of more detailed information from film records, including scan parameters, to allow estimation of doses.
The study will also spearhead a planned international study of the long-term risks associated with CT.
Comparison of Dose of Common Paediatric Fluoroscopic Investigations on New Fluoroscopy Unit Compared to Old
C.A. Corry, A.G. Wilkinson. Royal Hospital for Sick Children, Edinburgh
Background: This year the RHSC replaced its old fluoroscopic unit (Philips DIAGNOST 96, installed in 1992) with a state of the art unit (Siemens AXION ICONOS R200)
Aim: To compare the dose to the patient before and after installation of the new equipment.
Method: Fluoroscopy time and Dose Area Product (DAP) for all barium swallows, micturating cystourethrograms and barium follow-throughs carried out in the five months immediately prior to decommissioning the old machine were compared with a similar number of investigations on the new fluoroscopy unit.
Results: For all 3 different investigations studied the average fluoroscopy time is comparable on both machines. The average DAP and DAP/fluoroscopy time (DF) are considerably lower in those investigations carried out on the new unit. The DF, which eliminates the effect of slight differences in average fluoroscopy time between the 2 groups, is 4.39-5.10 times lower on the new unit compared to the old.
Conclusion: A five-fold dose reduction has been achieved by the replacement of the old fluoroscopy unit. Given the risks that the use of radiation poses in the paediatric population, this audit confirms the imperative of replacing old fluoroscopy systems in paediatric radiology departments.
Radiological or Surgical Drainage of Paediatric Empyeme? – The Edinburgh Experience.
P. Guntur, A.G. Wilkinson. Royal Hospital for Sick Children, Edinburgh
Purpose: To assess the efficacy of video assisted thoracoscopic debridement and drainage (VATS) and pigtail catheter drainage (PTC), used in the management of paediatric empyema and parapneumonic effusions (PPE).
Methods and Materials: 57 children underwent 73 procedures for drainage of empyema or PPE, between 1998 and 2006. A retrospective analysis was done 24 patients underwent PTC and 21 underwent VATS, 12 patients had both. All patients had urokinase via the drains, Radiological resolution of CXR findings, duration of chest drains and length of hospital stay were analysed. A scoring system based on obliteration of mediastinal, diaphragmatic and chest wall outlines was used to assess CXR features.
Results: Mean duration of chest drains in VATS and PTC was 3.23 and 5.79 days respectively (p=0.0003) Minimal or no radiological residue was seen in 5.8 weeks in VATS and 5.1 weeks in PTC. PTC failed in 14 pts (39%), who were subsequently treated with VATS (12 pts) or further PTC (2), 2 (6%) VATS failures were noted.
Conclusion: VATS resulted in high procedural success; short hospital stay and short chest drain duration. No difference was observed in the time taken for radiological resolution.
Posterior Reversible Encephalopathy Syndrome; A Clinico-radiological Review
C. Miller, D. Peake, L.K.R. MacPherson, H.J. Williams
Introduction: Posterior Reversible Encephalopathy Syndrome (PRES) classically present with headaches, altered mental status, visual disturbance and seizures, but symptoms may vary. Aetiological factors include hypertension, organ transplantation and immunosuppressive drug. The diagnosis is made on identification of typical MR imaging findings. Abnormal signal is seen predominantly in the posterior cerebral artery territory bilaterally. Diffusion weighted imaging helps to determine prognosis by distinguishing cytotoxic oedema (permanent injury) from vasogenic oedema (likely reversible injury). CT images show corresponding areas of reduced attenuation.
Method: Retrospective review of 9 cases of PRES diagnosed at Birmingham Children’s Hospital, between January 2004 and March 2006, with analysis of clinical presentation, aetiology and CT and MR imaging findings.
Results: Clinical presentation varied from altered level of consciousness, with visual disturbance to seizures requiring ventilation. The typical imaging patterns were recognised in all patients and unrestricted diffusion correlated positively with favourable outcome.
Conclusion: Clinical awareness of PRES and the early diagnosis using imaging is essential to limit potential morbidity, by directing appropriate clinical management, such as control of blood pressure.
An Audit of Peripherally Inserted Central Catheters (PICCs) in Children with Difficult Intravenous Access using Image Guidance (IG)
Royal Hospital for Sick Children, Glasgow
Purpose: An audit of IG PICC insertion against the thresholds in the guidelines for central venous access published by the Society of Interventional Radiology.
Methods and Materials: Patient data for PICC insertion from May 2005 – September 2006 was obtained from our paediatric interventional radiology database. The following were assessed: demographics, ASA class, indications, insertions site, line type inserted, initial (< 24 hours), early (<30 days) and late (>30 days) complications.
Results: 41 PICC lines were placed in 37 patients (M-F 27:10), age range 5 weeks – 17 years, under IG, 4 patients had multiple PICC insertion episodes. Procedural failure occurred in two. The commonest indication was difficult6 IV access, the commonest insertion site was basilica (72%) vein, and the commonest line type the silicone single lumen cuffed 4F (72%),. Initial complications included supraventricular tachycardia, arterial puncture and failure of line sampling (total *%). Early complications (26%) included line infection (4.8%), fracture (2.4%), tip migration (7.3%), dislodgement (4.8%), leakage (2.4%), occlusion (7.3%) and deep venous thrombosis (2.4%). One major complication required unplanned increase in the level of care, prolonged hospitalisation and permanent adverse events (2.4%).
Conclusions: The major and the initial complication rate concurred with the thresholds but the early complication rate was above the threshold. Reasons for this will be discussed.
Observational Study of Skeletal Surveys for Suspected Non-Accidental Injury following the BSPR Guidelines
S. Swinson, M Tapp, R Brindley, S Chapman, K Johnson. Birmingham Children’s Hospital
Aim: To review the standard of skeletal surveys performed in the UK, following the publication of the 2004 BSPR guidelines for non-accidental injury.
Materials and Methods: Fifty consecutive skeletal surveys received for second opinion at Birmingham Children’s Hospital between November 2005 and March 2006 were reviewed. The views obtained were audited against the gold standard 21 views recommended in the BSPR guidelines. Additionally, each view was assessed for technical quality out of a maximum score of 11. The results were compared to those of the 2003 study by Offiah and Hall. Additional information obtained included whether images were hard or soft copy and whether a CT head was performed.
Results: A mean of 17.9 (range 10-21) of the 21 recommended views were covered per survey and ten skeletal surveys (20%) included all 21 recommended views (previously 0%) The mean technical score per film was 9.8 (89%). Thirty-three skeletal surveys were sent for review on CD (66%) and 33 patients had documented CT head (66%).
Conclusion: There is still considerable variation in skeletal surveys performed but significant improvement in all areas has been observed in the light of BSPR guidelines. Room for improvement remains and further publicity of the guidelines is recommended.
The Rate of Skeletal Maturation in the Scottish Population – aA Comparison Across 25 years (1980-2005)
S.L. Waller, J. S. Huntley, D.E. Porter, L. Williams, A .G. Wilkinson
Royal Hospital for Sick Children, Edinburgh
Background: Bone age assessment is commonly performed in children with generalised growth abnormalities and limb length discrepancies.
Objective: A retrospective cross-sectional study was performed to compare the rates of skeletal maturation in Scottish populations 25 years apart (1980-2005).
Patients and methods: A cohort of sequentially archived hand-wrist radiographs was identified from the patients at a Scottish paediatric hospital from 1980 and from 2005. All radiographs were performed following trauma. The bone age was measured according to the carpal scoring system of the Tanner-Whitehouse 2 method.
Results: 104 and 103 radiographs were included from 1980-2005 respectively. The radiographs from 2005 showed the children to have achieved older bone ages for given chronological ages than in 1980 (p < 0.0001).
Discussion: It is likely that the aetiology of the increased rate of skeletal maturation we have demonstrated is multi factorial, and that in utero and childhood nutritional factors are important.
Conclusion: The findings have an important implication for the management of children with limb-length discrepancy. Children may not have the growth potential anticipated by chronological age; this will affect the timing of surgery and medical treatment of abnormalities of puberty and stature.
Update on Screening for Developmental Dysplasia of the Hips (DDH)
R. Arthur. The General Infirmary at Leeds.
The National standards for the newborn physical examination are currently being revised by the Child Health Screening Subgroup of the National screening committee. These include a new approach to the screening for developmental dysplasia of the hip.
It is proposed that an ultrasound examination will be recommended for all infants with clinically detectable hip instability by 4 weeks of age and in addition all those identified as having risk factors for DDH by 6 weeks of age i.e. the introduction of selective screening using ultrasound. Currently the feasibility and costs of introducing this programme are being considered.
During this short presentation I will outline the proposal for screening for DDH and the steps being taken to assess the feasibility of the programme. There are many problems to overcome including the standardisation and accreditation of any hip screening programme. Discussion of these issues will be encouraged.