Clinical application of ultrashort echo-time MRI for lung pathologies in children.

Lung magnetic resonance imaging (MRI) is considered to be challenging, because the low proton density of the tissue, fast signal decay, and respiratory artefacts hamper adequate image quality. MRI of the lungs and thorax is increasingly used in the paediatric population, because it is a radiation-free alternative to chest CT. Recently, ultrashort echo-time (UTE) sequences have been introduced into clinical MRI protocols, in order to improve the contrast-to-noise ratio due to reduced susceptibility artefacts and to depict structural alterations comparable to CT. The purpose of this review is to provide an overview of various clinical conditions and pathologies in the paediatric chest depicted by an UTE sequence, the so-called three-dimensional (3D) Cones sequence, in comparison with conventional MRI sequences. Besides describing typical features of cystic fibrosis, we present UTE application in other more or less common paediatric lung pathologies, for instance, interstitial pneumopathies, pulmonary infections, and congenital pulmonary malformations.

Multicentre reference values for cardiac magnetic resonance imaging derived ventricular size and function for children aged 0-18 years.

AIMS: Cardiovascular magnetic resonance (CMR) imaging is an important tool in the assessment of paediatric cardiac disease. Reported reference values of ventricular volumes and masses in the paediatric population are based on small cohorts and several methodologic differences between studies exist. We sought to create steady-state free precession (SSFP) CMR reference values for biventricular volumes and mass by combining data of previously published studies and re-analysing these data in a standardized manner. METHODS AND RESULTS: A total of 141 healthy children (68 boys) from three European centres underwent cine-SSFP CMR imaging. Cardiac structures were manually contoured for end-diastolic and end-systolic phases in the short-axis orientation according to current standardized CMR post-processing guidelines. Volumes and masses were derived from these contours. Age-related reference curves were constructed using the lambda mu sigma method. Median age was 12.7 years (range 0.6-18.5). We report biventricular volumes and masses, unindexed and indexed for body surface area, stratified by age groups. In general, boys had approximately 15% higher biventricular volumes and masses compared with girls. Only in children aged <6 years old no gender differences could be observed. Left ventricle ejection fraction was slightly higher in boys in this study population (median 67% vs. 65%, P = 0.016). Age-related reference curves showed non-linear relations between age and cardiac parameters. CONCLUSION: We report volumetric SSFP CMR imaging reference values for children aged 0-18 years old in a relatively large multi-centre cohort. These references can be used in the follow-up of paediatric cardiac disease and for research purposes.

Cardiac function after repair of tetralogy of fallot: how are the atria performing? pilot study by cardiac magnetic resonance imaging.

The atria of the heart function as reservoir, conduit, and active pump and are critical for ventricular filling and cardiac output. We sought to evaluate right (RA) and left atrial (LA) function in patients after tetralogy of Fallot (TOF) repair by using cardiovascular magnetic resonance. Twelve TOF patients, age 16.7 ± 6.1 years, weight 50.9 ± 14.9 kg, were compared to 10 healthy volunteers, age 18.8 ± 6.8 years, weight 52.3 ± 20.8 kg. Both atria and both ventricles were imaged in short-axis planes by Steady State Free Precession. Volume changes and all derived atrial functional parameters were calculated from the volume/time curves obtained after segmentation on the cine images. Blood flow across the AV valves was used to define ventricular diastolic dysfunction. TOF patients showed similar maximal RA volume compared to controls, but increased volumes at mid-diastole (p < 0.05), resulting in a decreased cyclic volume change and atrial filling fraction (p < 0.01), and a decreased passive emptying volume and fraction (p < 0.01). In patients with diastolic dysfunction, conduit volume was increased (p < 0.05), and active emptying volume and fraction tended to be increased, respectively. No significant changes were found in LA, except for a decreased passive emptying fraction (p < 0.05). RA function and particularly reservoir function are impaired in TOF patients. The RA conduit/reservoir ratio is increased and reflects the lost of the ability of the atrium to fill the ventricle by pulsatile flow.

A 12-year-old girl with absent radial pulse: arterial thoracic outlet syndrome with subclavian artery aneurysm and thrombosis of the brachial artery.

Brachial arterial occlusion is rare in children and adolescents. Once a traumatic cause is excluded, the differential diagnosis consists of a variety of rare conditions. We report the case of a 12-year-old girl whose presenting symptoms--an absent radial pulse and Raynaud's phenomenon of the right hand--could be easily mistaken for a vasculitis. She was found to have arterial thoracic outlet syndrome with right subclavian artery compression and aneurysm formation caused by an anomalous first rib and consecutive thromboembolic occlusion of the brachial artery. The diagnosis and differential diagnosis of this condition are reviewed.

Accuracy of linear intraoral measurements using cone beam CT and multidetector CT: a tale of two CTs.

OBJECTIVES: The aim was to compare the accuracy of linear bone measurements of cone beam CT (CBCT) with multidetector CT (MDCT) and validate intraoral soft-tissue measurements in CBCT. METHODS: Comparable views of CBCT and MDCT were obtained from eight intact cadaveric heads. The anatomical positions of the gingival margin and the buccal alveolar bone ridge were determined. Image measurements (CBCT/MDCT) were performed upon multiplanar reformatted data sets and compared with the anatomical measurements; the number of non-assessable sites (NASs) was evaluated. RESULTS: Radiological measurements were accurate with a mean difference from anatomical measurements of 0.14 mm (CBCT) and 0.23 mm (MDCT). These differences were statistically not significant, but the limits of agreement for bone measurements were broader in MDCT (-1.35 mm; 1.82 mm) than in CBCT (-0.93 mm; 1.21 mm). The limits of agreement for soft-tissue measurements in CBCT were smaller (-0.77 mm; 1.07 mm), indicating a slightly higher accuracy. More NASs occurred in MDCT (14.5%) than in CBCT (8.3%). CONCLUSIONS: CBCT is slightly more reliable for linear measurements than MDCT and less affected by metal artefacts. CBCT accuracy of linear intraoral soft-tissue measurements is similar to the accuracy of bone measurements.

Effect of different quantities of a sugared clear fluid on gastric emptying and residual volume in children: a crossover study using magnetic resonance imaging.

BACKGROUND: Gastric emptying in the first 2 h after 7 ml kg(-1) of sugared clear fluid has recently been investigated in healthy children using magnetic resonance imaging (MRI). This study aims to compare gastric volume and emptying half-life during 1 h after 3 or 7 ml kg(-1) sugared clear fluid intake. METHODS: Fourteen healthy volunteer children aged 11.1 (8.2-12.5) yr were investigated prospectively after administration of 3 and 7 ml kg(-1) diluted raspberry syrup in a randomized order, after overnight fasting (baseline). Gastric content volume (GCV(w)) was assessed with a 1.5 Tesla MRI scanner in a blinded fashion. Data are presented as median (range) and compared using the Wilcoxon test. RESULTS: Baseline GCV(w) was 0.39 (0.04-1.00) and 0.34 (0.07-0.75) before intake of 3 and 7 ml kg(-1) syrup, respectively (P=0.93). GCV(w) was 0.45 (0.04-1.55)/1.33 (0.30-2.60) ml kg(-1) 60 min after ingestion of 3/7 ml kg(-1) syrup (P=0.002). Thus GCV(w) had declined to baseline after 3 ml kg(-1) (P=0.39) but not after 7 ml kg(-1) (P=0.001) within 60 min. T(1/2) was 20 (10-62)/27 (13-43) min (P=0.73) after 3/7 ml kg(-1). CONCLUSION: In healthy volunteer children, residual GCV(w) 1 h after intake of 3 ml kg(-1) syrup is significantly smaller than that after 7 ml kg(-1) and within the range of baseline.

Residual gastric contents volume does not differ following 4 or 6 h fasting after a light breakfast - a magnetic resonance imaging investigation in healthy non-anaesthetised school-age children.

BACKGROUND: While American Society of Anesthesiologists and European Society of Anaesthesiology guidelines recommend 6 h pre-anaesthetic fasting for food and non-clear fluids in children, some institutions allow shorter fasting times of 4 h. Aim of this pilot study was to compare weight-indexed residual gastric contents volumes (GCV(w)) after 4 vs. 6 h after a light breakfast, using magnetic resonance imaging (MRI) in healthy volunteer children not scheduled for anaesthesia. METHODS: Four vs. 6 h (F(4) /F(6)) of food fasting were simulated in a crossover study. After overnight fasting (baseline), each child ingested a light breakfast (cereal flakes, milk products) on two separate days. Additional clear fluid (7 ml/kg raspberry syrup) was given either after 2 (F(4) ) or 4 h (F(6) ), followed by half-hourly MRI acquisition for 2 h. MRI was obtained on a 1.5 Tesla scanner as 5 mm axial images (FIESTA) and volumes were traced manually by one blinded observer. Data are given as median (range) or mean ± standard deviation. RESULTS: Eighteen healthy volunteers aged 9.0 (6.8-12.2) years participated. GCV(w) for F(4) and F(6) at baseline was 0.50 ± 0.27 and 0.76 ± 0.48 ml/kg (P = 0.07), respectively, GCV(w) after 4 and 6 h was 0.72 ± 0.85 and 0.47 ± 0.25 ml/kg (P = 0.88). T(1/2) after syrup intake was 30.8 ± 12.2 and 28.3 ± 5.7 min (P = 0.47) for F(4) and F(6) , respectively. CONCLUSION: Residual gastric contents volumes at a hypothetical anaesthesia start were similar for 4 and 6 h food fasting in healthy volunteer school-age children.

Gastric emptying after overnight fasting and clear fluid intake: a prospective investigation using serial magnetic resonance imaging in healthy children.

BACKGROUND: Current guidelines recommend preoperative fasting of 2 h for clear fluids, which is often exceeded in routine clinical practice. Existing data on residual gastric volumes in children do not consider fluid intake within <2 h and rely on the aspiration of gastric contents via a gastric tube. This study evaluated the emptying of clear fluids from the stomach using magnetic resonance imaging (MRI). METHODS: Healthy volunteers aged 6-14 years were asked to fast overnight. MRI scans to assess gastric volumes were obtained before and immediately after drinking 7 ml kg(-1) of diluted raspberry syrup and then every 30 min up to 120 min. Volumes were determined by a blinded investigator and indexed gastric fluid/air volumes (GFV(w)/GAV(w)) and half-life (t(1/2)) of GFV(w) course after clear fluid intake were calculated. RESULTS: Sixteen children, median age 9.2 (range 6.4-12.8) years, were investigated. Median (range) GFV(w) was 0.62 (0.15-0.97) ml kg(-1) before and 6.68 (4.77-7.78) ml kg(-1) immediately after fluid intake, and 2.92 (0.43-5.04), 1.27 (0.28-3.62), 0.42 (0.07-2.49), and 0.32 (0.04-1.13) ml kg(-1) 30, 60, 90, and 120 min thereafter. Median GFV(w) declined exponentially (t(1/2)=26.1 min). Median individual t(1/2) was 23.6 (range 17.9-47.8) min. GAV(w) showed considerable intra- and inter-individual variation. CONCLUSIONS: In healthy school children, gastric emptying after ingestion of clear fluid occurs with a median half-life time of <30 min but with considerable inter-individual variation.

[Periorbital ecchymosis--trauma or tumor?]. / Säugling mit Brillenhämatom - Trauma oder Tumor?

We report about an 11 month old patient, who presented with progressive supraorbital swelling, periorbital ecchymosis, hepatosplenomegalia and B-symptoms. Neuroblastoma was subsequently diagnosed based on the clinical history, physical examination, laboratory tests and imaging findings. Neuroblastoma is the second most frequent solid tumor in infancy. Clinical symptoms are not specific. The so called "raccoon eyes", as seen in our patient, result from osseous metastasis to the orbits and skull. Periorbital swelling may initially be misinterpreted as child abuse. Prognosis of neuroblastoma depends on various factors including initial tumor staging, tumor biology and the child's age.

Ingested pins causing perforation.

We report two children who underwent endoscopic removal of ingested foreign bodies which had perforated the stomach, one of which had migrated into the thorax.