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R Wunsch

Publications and source records attributed to R Wunsch.

17 recordsLinked to original sources
PubMed2007

[Prospective comparison of different ultrasound modalities to measure thicknesses less than 1 mm].

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.

Age Factors↗
PubMed2006

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.

Acute Disease↗
PubMed2005

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.

Adolescent↗
PubMed2004

[3D-visualization by MRI for surgical planning of Wilms tumors].

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.

Age Factors↗
PubMed2004

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.

Abdominal Neoplasms↗
PubMed2003

[Thoracic findings in pediatric patients with cystic fibrosis].

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.

Adolescent↗
PubMed2003

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.

Canavan Disease↗
PubMed2001

[Static-dynamic MR urography. Comparison with excretory urography and scintigraphy in experimentally-induced urinary tract obstruction].

PURPOSE: To assess the diagnostic value of combined static-dynamic MR urography (MRU) for the functional-morphological evaluation of experimentally induced urinary tract obstruction. METHODS: Static-dynamic MRU--combination study with a respiratory-triggered 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA and furosemide--was obtained in comparison with 99mTc-MAG3 diuretic renal scintigraphy (DRS), excretory urography (EU) and ultrasound (US) in 29 healthy piglets and in 20 piglets with surgically induced ureteric stenosis (total of 50 postoperative examination blocks). RESULTS: MRU allowed complete depiction of the urinary tract in all controls, in operated piglets the stenosis was always correctly identified. Quality of MRU was superior to EU in 36 of 43 comparative studies. Calculation of single kidney function from parenchymal renograms, and assessment of urinary excretion from whole-kidney renograms resulted in a highly significant agreement of MRU with DRS. CONCLUSION: Static-dynamic MR urography allows excellent depiction of experimentally induced urinary tract obstruction, and reliable assessment of individual renal function and urinary excretion. Two advantages of the method stand out, it does not require radiation and it permits a functional-morphological correlation.

Animals↗
PubMed2001

[Acute hematogenous osteomyelitis--exclusion with Turbo-STIR sequence?].

The timely diagnosis and early initiation of antibiotic therapy determine the clinical course of an acute hematogenous osteomyelitis. Consequently, a fast and efficient MRI examination protocol is crucial. We retrospectively evaluated various MR sequences used in the examination of 8 children having osteomyelitis. The examinations were conducted using a 0.5 T MR machine. All patients had a high signal intensity of the lesion in the IR sequence with fat suppression (turbo-STIR). An acute osteomyelitis can be excluded in the absence of signal intensity increase in the turbo-STIR sequence without the necessity of having to perform additional sequences.

Acute Disease↗
PubMed2001

[Quality of ambulatory thoracic radiography in the child--a pilot study].

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.

Adolescent↗
PubMed2001

Internal jugular venous valves in children: high-resolution US findings.

The aim of this study was to determine in children the prevalence rate and to describe the sonographic morphology of the valves in the internal jugular veins. One hundred twenty children (60 boys and 60 girls; mean age +/- SD 10 +/- 4 years, age range 3-20 years) were recruited for the study. They underwent sonographic examination of both internal jugular veins. The number of valvular cusps, the length of the cusps and exact site of origin were recorded. In 96% of the children a valve was found in one or both internal jugular veins. Within this group a valve was detected unilaterally in 26% and bilaterally in 74% of the cases. Ultrasound morphological and morphometric analysis was carried out in a total of 239 internal jugular veins; 200 (84%) veins were found to have valves. The origin of the cusps was located at a mean distance of 9 mm (0-26 mm) proximal to the confluence of the subclavian and internal jugular veins into the brachiocephalic vein. A valve in the distal part of the internal jugular vein is a very common finding with characteristic features on US.

Adolescent↗
PubMed2001

Contrast-enhanced harmonic imaging for the diagnosis of vesicoureteral reflux in pediatric patients.

OBJECTIVE: Harmonic imaging using phase or pulse inversion technology is a new sonographic diagnostic modality that has the potential to produce images of a higher quality than can be obtained with the conventional method. The aim of this study was to compare both types of harmonic modalities--tissue and contrast harmonic imaging--with the fundamental imaging mode in contrast-enhanced B-mode sonographic diagnosis of vesicoureteral reflux. SUBJECTS AND METHODS: Fifty-four children presenting for diagnostic examination of vesicoureteral reflux underwent standard sonography of the urinary tract in the fundamental mode, followed by intravesical administration of a galactose-based contrast medium containing microbubbles. The contrast-enhanced sonography was conducted by scanning the bladder and each kidney in transverse and longitudinal planes, from ventral and dorsal views, consecutively in B-mode using fundamental, contrast harmonic, and tissue harmonic imaging modalities. Soft-touch buttons on the console screen were used to alternate between the three imaging options, so that switching from one modality to the other could be done almost instantaneously. For comparison, in each patient, we selected one set of contrast-enhanced images of the bladder and two sets, one ventral and one dorsal, of the kidney. In a series, the images were compared and ranked from 1 to 3, with 1 being the best, with regard to sonomorphology (demarcation of the retrovesical space and renal pelvis as the potential sites to look for vesicoureteral reflux) and reflux detection and conspicuity, if present. RESULTS: In all, 248 sets of images were available for comparison. The delineation of both the retrovesical space and the renal pelvis was found to be best with tissue harmonic imaging in 84% and 96% of the image sets, respectively (p < 0.01). Forty-one sets of images were compared from 27 kidney-ureter image units of 22 children (41%) with reflux. The refluxing microbubbles were much more conspicuous in the harmonic imaging mode (tissue harmonic, 100%; contrast harmonic, 93%) than in the fundamental mode (p < 0.01). In eight kidney-ureter units, the reflux was detected only by using the harmonic imaging modalities. CONCLUSION: Visualization of the urinary tract and detection of ultrasound contrast media is significantly improved by the use of the harmonic imaging modalities. When both fundamental and harmonic imaging options are available, we recommend harmonic imaging for contrast-enhanced sonographic diagnosis of vesicoureteral reflux.

Adolescent↗
PubMed1999

[Foreign body aspiration].

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.

Bronchography↗
PubMed1999

[Foreign body ingestion].

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.

Child↗
PubMed1997

[Lymphoma in childhood].

Manifestation of childhood Hodgkin's disease and Non-Hodgkin's lymphoma differ, especially in the latter, from those in adults. Extranodal involvement is seen even more frequently in childhood Non-Hodgkin's lymphomas than in adults. This article reviews the radiological findings in malignant lymphomas in children, explains the differences in the manifestation of Hodgkin's lymphomas, of different subtypes and of the malignant lymphomas in adults. The problems in diagnosis of organ manifestation and special problems of diagnostic imaging procedures in children are discussed.

Adolescent↗