[Imaging of acute abdomen in childhood and adolescence]. / Bildgebung beim akuten Abdomen im Kindes- und Jugendalter.

Acute abdominal pain in childhood is a frequent reason for a medical consultation. The main diseases that lead to the clinical situation of acute abdomen show a significant age dependency. It is reasonable to group such ailments into three age categories: (1) the neonatal and infant period, (2) toddlerhood to kindergarten and (3) school age children. The task of the pediatric radiological examination is the differential diagnostic correlation of symptoms to the respective diseases. In children ultrasound is the appropriate method of choice.

[Ultrasound imaging of the testes in children and adolescents]. / Hodensonographie im Kindes- und Jugendalter.

BACKGROUND: Ultrasound, the imaging method of choice to evaluate abnormalities of the testes and the scrotum, provides accurate anatomic details and allows the assessment of perfusion using color Doppler and power Doppler. Ultrasound represents a rapid and reliable procedure which in most cases leads to a conclusive diagnosis. DIFFERENTIAL DIAGNOSIS: The three most common conditions in the clinical picture of acute scrotum are testicular torsion, torsion of the testicular appendages and inflammatory changes of the testis and the epididymis (epididymo-orchitis). Especially in the case of testicular torsion, rapid diagnosis is essential since time is an important factor to initiate organ-preserving therapy. EQUIPMENT TECHNOLOGY: High-frequency linear array transducer (at least 10 MHz), which allows detection of slow flow rates, is recommended.

Tradeoff between micropollutant abatement and bromate formation during ozonation of concentrates from nanofiltration and reverse osmosis processes.

Water treatment with nanofiltration (NF) or reverse osmosis (RO) membranes results in a purified permeate and a retentate, where solutes are concentrated and have to be properly managed and discharged. To date, little is known on how the selection of a semi-permeable dense membrane impacts the dissolved organic matter in the concentrate and what the consequences are for micropollutant (MP) abatement and bromate formation during concentrate treatment with ozone. Laboratory ozonation experiments were performed with standardized concentrates produced by three membranes (two NFs and one low-pressure reverse osmosis (LPRO) membrane) from three water sources (two river waters and one lake water). The concentrates were standardized by adjustment of pH and concentrations of dissolved organic carbon, total inorganic carbon, selected micropollutants (MP) with a low to high ozone reactivity and bromide to exclude factors which are known to impact ozonation. NF membranes had a lower retention of bromide and MPs than the LPRO membrane, and if the permeate quality of the NF membrane meets the requirements, the selection of this membrane type is beneficial due to the lower bromate formation risks upon concentrate ozonation. The bromate formation was typically higher in standardized concentrates of LPRO than of NF membranes, but the tradeoff between MP abatement and bromate formation upon ozonation of the standardized concentrates was not affected by the membrane type. Furthermore, there was no difference for the different source waters. Overall, ozonation of concentrates is only feasible for abatement of MPs with a high to moderate ozone reactivity with limited bromate formation. Differences in the DOM composition between NF and LPRO membrane concentrates are less relevant than retention of MPs and bromide by the membrane and the required ozone dose to meet a treatment target.

[Comparative ultrasound visualization of clinically relevant structures for evaluating the infant hip joint utilizing trapezoidal vs. parallel transducers]. / Vergleichende Darstellung beurteilungsrelevanter Strukturen der kindlichen Hüfte mittels paralleler und trapezförmiger Ultraschallabbildung.

PURPOSE: Sonographic evaluation of the infant hip joint according to the method of Graf has proven to be an important pediatric investigative instrument. Our goal was to investigate quantitatively whether (and in what ways) the clinically relevant infant hip joint structures visualize differently when utilizing trapezoidal as opposed to linear transducers. Our approach was both theoretical via a mathematical model and practical with in-vivo measurements in neonates. MATERIALS AND METHODS: In a prospective study: 1. theoretical and computed analyses were performed for both linear and trapezoidal transducers regarding their respective accuracy for demonstrating the anatomic geometry of the infant hip, assuming not only correctly centered transducer positioning but also cases with off-centered displacement in the cranial or caudal direction; 2. both hip joints in 97 infants were examined by experienced investigators with comparison of the results for parallel vs. trapezoidal transducers. RESULTS: Theoretical mathematical error analysis reveals no intrinsic systemic deviations between trapezoidal vs. parallel transducers in US scanning of the infant hip and furthermore no inherent disadvantages in the trapezoidal technique. Even when off-center transducer alignments of 1.5 cm are employed in the mathematical models, there is no significant relative distortion of the required anatomic structures when comparing the characteristics of both transducers. The practical in-vivo data from our 97 neonates confirmed the theoretical considerations. CONCLUSION: No loss of accuracy or other negative factors are evident when trapezoidal transducers are used to visualize the infant hip joint in comparison with the customary parallel technique. There are no significantly measurable differences between the two approaches.

Lifestyle intervention "Obeldicks Mini" for obese children aged 4 to 7 years.

Interventions for obese preschool children are missing in Germany. However, an effective and long-lasting improvement of the health behaviour seems plausible especially in this age, since the health behaviour is impressed in this age span. Therefore, we developed the outpatient one-year lifestyle intervention "Obeldicks Mini" for obese children aged 4 to <8 years and their parents based on nutrition, education, physical activity, and behaviour therapy. This intervention addressed primarily the parents. The training program was evaluated in 84 patients. In the three months before intervention, the degree of overweight significantly increased in the participants (in mean+0.12 SDS-BMI; p=0.002). Based on an intention-to-treat approach, 69% of the participants reduced their overweight, while 24% dropped out of the intervention. The mean SDS-BMI reduction was 0.46 (p<0.001) and was associated with a significant improvement of cardiovascular risk factors such as hypertension, dyslipidemia and insulin resistance. Intima-media thickness as predictive factor for later atherosclerosis decreased significantly. Even 3 years after end of intervention, the achieved weight loss sustained.

[Prospective comparison of different ultrasound modalities to measure thicknesses less than 1 mm]. / Prospektiver Vergleich verschiedener Ultraschallverfahren zur Dickenmessung im Grenzbereich von Dicken unter 1 Millimeter.

PURPOSE: New ultrasound techniques with improved visualization and better transducers constantly expand the methods of measurement. In the border area in the case of thickness measurements of less than 1 millimeter, e. g. the measurement of the "Intima-Media Thickness" (IMT), it is not clear if better visualization comes at the price of incorrect measurement values. We checked different modalities for accuracy and visualization quality. MATERIALS AND METHODS: We prospectively examined the IMT of obese children using different ultrasound modalities. The image quality was evaluated by two independent pediatric radiologists. A phantom with an exact thickness of 0.3 mm (value of the thinnest measured IMT thickness) was subsequently created by precision engineers. Measurements were carried out and analyzed using fundamental ultrasound, tissue harmonic imaging, speckle reduction imaging and cross beam (real-time compound) imaging. RESULTS: The best image quality was reached using speckle reduction imaging. This technique and fundamental ultrasound produced the most exact data. However, the recognizability was worse in fundamental ultrasound than in speckle reduction imaging. CONCLUSION: Speckle reduction imaging appears to be the best technique for measuring thicknesses less than 1 mm.

The interventional therapy of varicoceles amongst children, adolescents and young men.

The retrograde sclerotherapy of the internal spermatic vein is a simple and safe method for the treatment of a varicocele. Approximately 5500 patients had so far undergone the interventional therapy in our departments. The methods of retrograde sclerotherapy will be described and alternative methods of treatment will be given in detail. The minor trauma, the low gonad dose and fast implementation coupled with a high success rate show that this method is very safe and efficient. We have, therefore, chosen it as the primary therapy.

[3D-visualization by MRI for surgical planning of Wilms tumors]. / 3-D-Visualisierung in der MRT zur Operationsplanung von Wilms-Tumoren.

PURPOSE: To improve surgical planning of kidney tumors in childhood (Wilms tumor, mesoblastic nephroma) after radiologic verification of the presumptive diagnosis with interactive colored 3D-animation in MRI. MATERIALS AND METHODS: In 7 children (1 boy, 6 girls) with a mean age of 3 years (1 month to 11 years), the MRI database (DICOM) was processed with a raycasting-based 3D-volume-rendering software (VG Studio Max 1.1/Volume Graphics). The abdominal MRI-sequences (coronal STIR, coronal T1 TSE, transverse T1/T2 TSE, sagittal T2 TSE, transverse and coronal T1 TSE post contrast) were obtained with a 0.5T unit in 4 - 6 mm slices. Additionally, a phase-contrast-MR-angiography was applied to delineate the large abdominal and retroperitoneal vessels. A notebook was used to demonstrate the 3D-visualization for surgical planning before surgery and during the surgical procedure. RESULTS: In all 7 cases, the surgical approach was influenced by interactive 3D-animation and the information found useful for surgical planning. Above all, the 3D-visualization demonstrates the mass effect of the Wilms tumor and its anatomical relationship to the renal hilum and to the rest of the kidney as well as the topographic relationship of the tumor to the critical vessels. One rupture of the tumor capsule occurred as a surgical complication. For the surgeon, the transformation of the anatomical situation from MRI to the surgical situs has become much easier. CONCLUSION: For surgical planning of Wilms tumors, the 3D-visualization with 3D-animation of the situs helps to transfer important information from the pediatric radiologist to the pediatric surgeon and optimizes the surgical preparation. A reduction of complications is to be expected.

Abdominal tumours in children: 3-D visualisation and surgical planning.

INTRODUCTION: Solid abdominal tumours are of special importance in the field of paediatric surgery. Because of the dangers of cumulative irradiation and improved delineation of soft parts MRI is usually employed in children for diagnostic assessment. Compiling the radiologic information for surgical planning is often difficult by conventional methods. Newly improved and efficient 3-D volume rendering software is now available for visual reconstruction of tumour anatomy utilising segmentation and other special techniques. Because the intraoperative complication rate is close to 20 % as described in the literature, optimal preoperative visualisation and planning would seem imperative. MATERIALS AND METHODS: All children with solid abdominal tumours at Heidelberg University in the year 2002 were included in this study. MR examinations were performed with a 0.5 Tesla magnet using a standard protocol. All MR data were processed with VG Studio Max 1.1, converting the two-dimensional data into three-dimensional data. RESULTS: This report presents 15 cases using this special technique: 7 with abdominal neuroblastoma, 6 with nephroblastoma, 1 ganglioneuroma, and 1 ovarian teratoma. CONCLUSIONS: Our experience shows that a better understanding of the surgical anatomy, particularly regarding the surrounding organs and vasculature, can be helpful in decreasing the incidence of inadvertent intraoperative injuries to these structures.

Small part ultrasound in childhood and adolescence.

Small-part sonography refers to the display of small, near-surface structures using high-frequency linear array transducers. Traditional applications for small part ultrasound imaging include visualization and differential diagnostic evaluation in unclear superficial bodily structures with solid, liquid and mixed texture, as well as similar structures in nearly superficial organs such as the thyroid glands and the testes. Furthermore indications in the head and neck regions are the assessment of the outer CSF spaces in infants, the sonography of the orbit, the sonography of the walls of the large neck vessels, the visualization of superficially situated lymph nodes and neoplasms. Clinical evidence concludes that sonography, having of all imaging modalities the highest spatial resolution in the millimeter- and micrometer range (100-1000µm), can be considered the best suited technique for examining superficial pathological formations and near-surface organs. In addition, it delivers important information about characteristic, often pathognomonic tissue architecture in pathological processes.

Terahertz-range free-electron laser electron spin resonance spectroscopy: techniques and applications in high magnetic fields.

The successful use of picosecond-pulse free-electron-laser (FEL) radiation for the continuous-wave terahertz-range electron spin resonance (ESR) spectroscopy has been demonstrated. The combination of two linac-based FELs (covering the wavelength range of 4-250 microm) with pulsed magnetic fields up to 70 T allows for multifrequency ESR spectroscopy in a frequency range of 1.2-75 THz with a spectral resolution better than 1%. The performance of the spectrometer is illustrated with ESR spectra obtained in the 2,2-diphenyl-1-picrylhydrazyl and the low-dimensional organic material (C6H9N2)CuCl3.

[Headache and diplopia in an extremely obese adolescent]. / Kopfschmerzen und Doppelbilder bei einem Jugendlichen mit extremer Adipositas.

BACKGROUND: The prevalence of idiopathic intracranial hypertension is increased in overweight children and adolescents. CASE REPORT: In a fifteen-year old, extremely obese adolescent with a history of headache and diplopia treatment with acetazolamide resulted in relief of the neurological symptoms.

Acute testicular torsion in children: the role of sonography in the diagnostic workup.

Acute testicular torsion in children is an emergency and has to be diagnosed urgently. Doppler sonography is increasingly used in imaging the acute scrotum. Nevertheless, in uncertain cases, surgical exploration is required. In this study, we attempted to define the role of Doppler sonography in the diagnostic workup of the acutely painful scrotum. All patients admitted between 1999 and 2005 with acute scrotal pain were included. After clinical assessment, patients were imaged by Doppler sonography with a ''high-end'' instrument. In cases of absent arterial perfusion of the testis in Doppler sonography, surgical exploration was carried out. Patients with unaffected perfusion were followed clinically by ultrasound for up to 2 years. Sixty-one infants and children aged 1 day to 17 years (median: 7.9 years) were included. In 14 cases, sonography demonstrated absent central perfusion, with abnormal parenchymal echogenicity in six. Absence of venous blood flow together with reduction of central arterial perfusion was found in one infant. In these 15 patients, surgical exploration confirmed testicular torsion. Among the other 46 patients, we found four cases with increased testicular perfusion and 27 with increased perfusion of the epididymis. In one infant, a testicular tumour was found sonographically, and orchiectomy confirmed diagnosis of a teratoma. Follow-up examinations of the conservatively treated patients showed good clinical outcome with physiologic central perfusion as well as normal echogenic pattern of both testes. No case of testicular torsion was missed. By means of Doppler sonography, an unequivocal statement regarding testicular perfusion was possible in all cases. The initial Doppler diagnosis was confirmed by operative evaluation and follow-up ultrasound. Testicular torsion can therefore be excluded by correctly performed ultrasound with modern equipment.

[Thoracic findings in pediatric patients with cystic fibrosis]. / Thorakale Veränderungen bei zystischer Fibrose im Kindesalter.

Cystic fibrosis is the most common autosomal recessive metabolic disease in Europe with an incidence of 1:2500. The severity of the lung disease is the most important factor of morbidity and mortality in CF-patients. Because of the better diagnostic and therapeutic modalities life expectancy has increased significantly. The underlying pathology is a defect of chromosome 7, which encodes the regulation of the fluid balance across the cell membrane which effects chloride as well as sodium. The exocrine glands produce a viscous mucus which obstructs the airways and promotes infections. The result is the destruction of lung parenchyma. In daily routine, chest x-ray is still the most important radiological tool, although computed tomography depicts changes in morphology earlier and more exactly. Recent research studies show that MRI has-because of its additional functional options-interesting aspects for the future.

[Foreign body aspiration]. / Fremdkörperaspiration.

Aspiration of foreign bodies is a common cause of respiratory distress in children between the age of 6 months and 3 years. The diagnosis of radiopaque foreign bodies is easy when the whole respiratory tract is depicted. Nonopaque foreign bodies need a more differentiated diagnostic approach. The first step should be plain films in inspiration and expiration. The performance of additional chest radiographs, fluoroscopy and if need be CT or nuclear scans depends on the result of the plain films. The chest radiograph may reveal a variety of findings, the commonest of which is unilateral air trapping. Rarely, atelectasis, recurrent pneumonia at the same localisation and inspiratory obstruction are found. Combinations of the above-mentioned findings are possible. Moreover, the absence of positive radiological findings does not exclude the diagnosis of foreign body aspiration.

Ultrasound findings in follow-up investigations in a case of aspartoacylase deficiency (canavan disease).

Aspartoacylase deficiency is a neurodegenerative disease which typically starts in the first months of life with muscular hypotonia and developmental standstill. One of the first diagnostic procedures in this situation is an ultrasound of the brain. There is little information available about sonographic changes in Canavan disease. We present for the first time an ultrasound follow-up in a proven case of aspartoacylase deficiency from 3 weeks to 22 months. High echogenicity of the white matter was present in the neonatal period. Additional sonographic phenomena resulting in a characteristic pattern were shown in further investigations. The distinctive sonomorphology is compared to a few other cases in the literature. The correlation to the neuropathological course of the white matter changes is discussed. Recognition of the sonographic features in addition to the clinical presentation may contribute to an effective biochemical work-up.

[Foreign body ingestion]. / Fremdkörperingestion.

Foreign body ingestion is not infrequent in infants and children. The diagnosis of radiopaque foreign body ingestion does not pose a major problem. It is crucial to take an X-ray from the pharynx to the level of the pylorus. If a foreign body that might get stuck at the ileocoecal valve is ingested, it is necessary to perform a radiograph of the whole abdomen. Foreign bodies that do not pass the cardia must be extracted endoscopically. In the case of foreign bodies with a smooth contour that have passed the pylorus, parents are advised to check the child's stool or collect it and bring it for X-raying. If after a week there is no definite evidence that the foreign body has been excreted a follow-up radiograph is carried out. If the foreign body is still in the stomach or duodenum, endoscopy is necessary. The detection of nonopaque foreign bodies can be facilitated by giving oral contrast medium, making the depiction of the foreign body as a filling defect possible. As a complication, perforation can occur, the diagnosis of which may entail the use of sonography, conventional radiography and, to a lesser extent, CT.

Metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) by hamster, mouse and rat intestine: relevance of species differences.

We recently demonstrated the metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in rat intestinal segments, as well as the inducibility of intestinal NNK metabolism by starvation or acetone treatment. To improve our understanding of intestinal NNK turnover we have additionally investigated NNK metabolism in isolated perfused jejunal segments from NMRI mice and Syrian golden hamsters. [14C]NNK (1 micromol/l) was metabolized extensively by jejunal segments from female NMRI mice (88.5%) and female Syrian hamsters (86.4%), whereas in male NMRI mouse segments a slightly lower metabolism (68.8%) was observed. Alpha-Hydroxylation was the predominant metabolic pathway in mice (58% of total metabolism), whereas in female Syrian hamsters N-oxidation accounted for >50% of the metabolites [4-(methylnitrosamino)-1-(3-pyridyl-N-oxide)-1-butanol 27%, 4-(methylnitrosamino)-1-(3-pyridyl-N-oxide)-1-butanone 22% of total radioactivity]. Formation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) was low in both species. Total NNK metabolism in male NMRI mice was increased by starvation to 84.4% and by acetone treatment to 90.0% of the absorbed radioactivity. This increase was due to an increase in N-oxidation, whereas the amounts of alpha-hydroxides and NNAL remained unchanged. In female Syrian hamsters acetone treatment had only minimal effects upon the metabolite composition. Acetone-treated NMRI mice and Syrian hamsters were additionally gavaged with the chemopreventive agent phenethylisothiocyanate (PEITC). In mice this treatment slightly decreased keto acid formation (0.6-fold, P<0.05), whereas in hamsters PEITC had no effect. In summary, intestinal metabolism of NNK in rats, mice and hamsters differs in both the extent of total metabolism (hamsters > or = mice > rats) and the metabolite composition, indicating major species differences.

[Quality of ambulatory thoracic radiography in the child--a pilot study]. / Qualität der ambulanten Röntgenthoraxuntersuchung des Kindes--eine Pilotstudie.

A quality control of outpatient paediatric chest X-rays was conducted in a sample of patients of one paediatric practice. During a period of eight months the technical image quality was analysed considering both diagnostic aspects and radiation protection. The quality of the 139 examined chest X-rays was inadequate concerning the collimation and focussing of the X-rays and the positioning of the patients. Exposure was estimated as average, sharpness was rated as good. In total 14% of the X-rays were not suitable for medical diagnosis. Image quality of the X-rays of infants (children younger than 6 years) was significantly lower compared to the total sample. Radiation protection standards were not fulfilled. As a conclusion from our results, improvements in outpatient paediatric radiography are urgently necessary. Quality control committees should pay particular attention in radiographs of infants.