Biomedical subjects

K Darge

Publications and source records attributed to K Darge.

At least 19 recordsLinked to original sources

PubMed2007

[Ectopic ureter with urinary dribbling in childhood -- a diagnostic challenge: our own experience and review of the literature].

Based on the observations in four girls suffering from constant urinary dribbling we analyzed the special features and difficulties in making the diagnosis of an ectopic ureter. In all patients there was marked diagnostic delay. In one symptomatic case the abnormality was not detected before the age of 18 years. Failure to recognize the characteristic signs and symptoms played a crucial role in delaying the diagnosis. Moreover, imaging of ureteral ectopia represents a diagnostic challenge. The ectopic ureters were associated with dysplastic, poorly functioning renal moieties. Common diagnostic imaging procedures, such as ultrasound, intravenous pyelography, or voiding cystourethrography yielded incomplete diagnostic information and often failed to provide a definitive diagnosis. The latter could only be obtained with MR urography. We assessed the diagnostic value of the different examinations and compared our findings with those reported in the literature.

Adolescent↗

PubMed2005

[Modern ultrasound technologies and their application in pediatric urinary tract imaging].

In children ultrasound plays a central role in the diagnostic imaging of the urinary tract. It is used most frequently and as a primary diagnostic option. Consequently, innovations in ultrasound technology and ultrasound contrast media have major impact on pediatric urosonography. Harmonic imaging is a modality that produces artifact-free images with high resolution. It has been shown that harmonic imaging is superior to fundamental mode in many urosonographic indications. Color Doppler is an established imaging modality, but its application for diagnosis of stones in the urinary tract, especially in children, is relatively new. The so-called twinkling sign, a color Doppler artifact at the site where one normally expects the acoustic shadow to be, enhances the conspicuity of the stone. A further development is three-dimensional (3D) ultrasound. It offers better volume measurement of the bladder and kidneys than 2D ultrasound. Contrast-enhanced voiding urosonography has already proven to be a valuable alternative in the diagnosis of vesicoureteral reflux. Thus, a significant decrease of radiation exposure has become possible as it replaces the radiological methods. With the introduction of contrast-specific ultrasound imaging modalities, further improvements in voiding urosonography are emerging.

Adult↗

PubMed2004

[Aseptic meningitis after intrathecal infusion of a parenteral nutrition solution: examples of rare malpositions of central venous catheters in preterm neonates].

BACKGROUND: Central venous catheters are an indispensable part of intensive care. In the management of preterm neonates, these are introduced after puncture of a peripheral subcutaneous vein. The catheters are supposed to be pushed forward with the venous flow. A chest X-ray is usually performed for verification of the position of the catheter. Localization of the tip of the catheter is often very difficult because of its extremely small diameter. METHODS: A malposition of a central venous catheter resulting in intrathecal infusion of parenteral nutrition and subsequent aseptic meningitis in a preterm neonate is presented. Further cases of catheter malpositions leading to arthrography, arteriography and incorrect position in various parts of the venous system are discussed. DISCUSSION AND CONCLUSION: The case reports demonstrate that wire-guided central venous catheters are not only advanced by the forward blood flow but can also inadvertently end up in undesired sites and may thus induce serious side effects.

Catheterization, Peripheral↗

PubMed2004

Progressively enlarging pericardial lipoma in a child.

Mediastinal lipomas are slowly growing tumours. Only very few cases have been reported in children. None of these included a rapidly enlarging lipoma. We present an 8-year-old severely adipose girl with an incidentally diagnosed mediastinal lipoma that showed rapid enlargement within 7 weeks.

Child↗

PubMed2003

[Advances in pediatric sonography].

Advances in the field of ultrasound technology and ultrasound contrast media over the past few years have also brought major improvements to pediatric sonography. Accordingly, contrast-enhanced voiding urosonography has become a valuable alternative in the diagnosis of vesicoureteral reflux. It is possible to achieve significant reduction in radiation exposure replacing the conventional radiologic methods used for reflux diagnosis with contrast-enhanced ultrasound. Through the introduction of harmonic imaging, an ultrasound scanning modality with high spatial and contrast resolution has become available. The modality was initially propagated as one to be applied in difficult-to-scan adults. However, initial experiences in pediatric applications are demonstrating the significant improvement it can bring in the ultrasound image quality, for example, in intestinal ultrasound. A further development is three-dimensional [3D] imaging using ultrasound. 3D-ultrasound not only offers an improvement in diagnosis but also in the acceptance of ultrasound in interdisciplinary work and teaching. The first applications of 3D-ultrasound in pediatrics are focusing on brain ultrasound and volume measurement of the kidneys.

Child↗

PubMed2003

Simultaneous voiding cystourethrography and voiding urosonography.

PURPOSE: To compare the diagnostic accuracy of contrast-enhanced voiding urosonography (VUS) and voiding cystourethrography (VCUG) during simultaneous performance of both examinations. MATERIAL AND METHODS: A total of 24 children, 16 girls and 8 boys, with a mean age of 3.5 years referred for reflux examination were recruited for the study. After transurethral bladder catheterization, radiographic contrast medium, followed directly by the US contrast medium, were administered. Fluoroscopic VCUG and VUS were carried out concurrently in the same patient. When 1 kidney was scanned by ultrasound, fluoroscopy was performed on the contralateral side. RESULTS: In 19 of the 47 kidney-ureter-units (KUU) vesicoureteral reflux (VUR) was detected. In 16 units the reflux was detected by both VCUG and VUS. In 3 KUUs the reflux was detected only at VCUG. All 3 cases were grade 1. Taking the VCUG as the reference standard, VUS had 84% sensitivity, 100% specificity, 100% and 90% positive and negative predictive values, respectively. CONCLUSION: A dependable comparison could be achieved by performing VCUG and VUS at the same time and under the same conditions. It reconfirmed that VUS is reliable in the exclusion or verification of reflux.

Child, Preschool↗

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

Reduction in voiding cystourethrographies after the introduction of contrast enhanced sonographic reflux diagnosis.

BACKGROUND: Voiding urosonography (VUS) using the intravesical application of an US contrast medium (Levovist) has been shown to have very high sensitivity and specificity in the diagnosis of vesicoureteric reflux (VUR) compared to voiding cystourethrography (VCUG). OBJECTIVE: To determine the extent of reduction of VCUGs after adding VUS to the diagnostic algorithm of VUR. MATERIALS AND METHODS: Over 2 years, 449 children (162 boys, 287 girls) were referred for diagnosis of possible VUR. The selection of a particular reflux examination was based on pre-defined criteria. VUS was performed primarily in girls and follow-up cases. The indications for VCUG were as follows: (a) boys - first examination for VUR, (b) specific request for urethra or bladder imaging, (c) girls - when VUR was diagnosed in the VUS and no VCUG had been done previously, and (d) inadequate VUS. RESULTS: VCUGs were primarily carried out in 141 cases. VUSs were performed in 308 patients. In 69 of these patients a VCUG followed during the same examination session. Thus 239 of 449 patients underwent only VUS, resulting in reduction of the VCUGs by 53 %. CONCLUSIONS: The number of VCUGs was significantly reduced as a result of the implementation of VUS as part of the routine diagnostic imaging modality for VUR. Consequently, the number of children that would have been exposed to ionising radiation was reduced by over half.

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↗

PubMed2001

The knee joint in early juvenile idiopathic arthritis. An ROC study for evaluating the diagnostic accuracy of contrast-enhanced MR imaging.

PURPOSE: Diagnosis of juvenile idiopathic arthritis (JIA) remains difficult due to unspecific clinical and laboratory findings, especially in early stages of the disease. The purpose of our study was to determine the sensitivity and specificity of MR imaging in diagnosing JIA of the knee joints. MATERIAL AND METHODS: Forty children (3-17 years old) clinically diagnosed with JIA (follow-up > 1 year) of a knee joint and a control group of 40 children with painful knee joints (MR diagnosis: bone bruise of the knee (n = 7), normal knee joint (n = 12), osteomyelitis (n = 6), septic arthritis (n = 2), bone tumor (n = 7) and miscellaneous bone lesions (n = 6)) were examined using a 1.5 T MR unit. T1-weighted spin-echo (SE), T2-weighted fast SE, contrast-enhanced T1-weighted SE and 2D gradient echo sequences were performed. The receiver operating characteristic (ROC) curves evaluation was conducted by 5 independent radiologists. RESULTS: The positive criteria for diagnosing JIA were joint effusions (n = 40), contrast-enhancing synovitis (n = 39), cartilage lesions (n = 15), subchondral erosions and bony destruction (n = 1). Sensitivity and specificity were 93.5% and 92.5%, respectively. Both cases of septic arthritis were misdiagnosed as JIA by all radiologists. CONCLUSION: Contrast-enhanced MR imaging seems to be a highly sensitive tool in establishing the diagnosis of JIA.

Adolescent↗

PubMed2000

Combined static-dynamic MR urography for the simultaneous evaluation of morphology and function in urinary tract obstruction. I. Evaluation of the normal status in an animal model.

OBJECTIVE: A new approach, combined static-dynamic MR urography is evaluated to determine its potential utility for the functional-morphological diagnosis of paediatric urinary tract obstruction. In this initial investigation we sought to evaluate the procedure by imaging the urinary tract of piglets. MATERIALS AND METHODS: Twenty-nine healthy piglets were studied with MR urography (MRU), 99mTc-MAG3 diuretic renal scintigraphy (DRS), ultrasound (US) and excretory urography (EU). The functional and morphological findings were compared. For MRU we combined a respiration-triggered 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA injection. RESULTS: MRU depicted the complete urinary tract with superior image quality compared to EU. Calculation of time-intensity curves from the dynamic sequence permitted determination of single kidney function from parenchymal ROIs and urinary excretion using the whole kidney ROI. MRU and DRS showed significant agreement in the assessment of both single kidney function and urinary excretion. Disturbances of urinary drainage were generally caused by an overfilled bladder. CONCLUSIONS: Combined static-dynamic MRU is well suited for the depiction of the complete urinary tract and for the determination of individual kidney function and urinary excretion in the piglet.

Animals↗

PubMed2000

Combined static-dynamic MR urography for the simultaneous evaluation of morphology and function in urinary tract obstruction. II. Findings in experimentally induced ureteric stenosis.

PURPOSE: To assess the diagnostic value of combined static-dynamic MR urography (MRU) for the functional-morphological evaluation of experimentally induced urinary tract obstruction in the piglet. MATERIALS AND METHODS: In 20 piglets unilateral ureteric stenosis was created operatively. Post-surgery repeated comparative examinations were obtained with MRU, diuretic renal scintigraphy (DRS), excretory urography (EU) and ultrasound (US). MRU was performed as a combination study with a static 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA with frusemide administration. RESULTS: MRU allowed complete depiction of the prestenotic urinary tract and of the stenosis in all cases. In 43 comparative studies MRU was superior to EU in 36, EU to MRU in 2. When single kidney function was calculated with both MRU and DRS, results were highly correlated (r = 0.92). When urinary excretion was compared, significant agreement was achieved with concordant findings in 86% and slightly discordant results in 12%. CONCLUSIONS: Static-dynamic MR urography permits excellent depiction of experimentally induced urinary tract obstruction in piglets 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 functional-morphological correlation.

Animals↗

PubMed2000

Differentiation of vascular birthmarks by MR imaging. An investigation of hemangiomas, venous and lymphatic malformations.

PURPOSE: To evaluate the use of MR imaging using standard sequences in the differentiation of common vascular birthmarks of soft tissues in childhood. MATERIAL AND METHODS: Forty-three lesions in 37 children (median age 33 months) with hemangiomas (n=25), venous (n=8) and lymphatic (n=10) malformations were retrospectively studied. Images were obtained with a 0.2 T and a 1.5 T MR unit, using T1-weighted spin-echo, T2-weighted turbo spin-echo and turbo STIR sequences. In addition, 19 contrast studies were evaluated. Signal intensities and morphological characteristics were analyzed. RESULTS: All hemangiomas were hyperintense in T2-weighted, and mostly (22/25) isointense compared to the surrounding skeletal muscle in T1-weighted images. The lesions were homogeneous or mildly inhomogeneous and well defined. Venous and lymphatic malformations showed similar patterns. Contrary to other lesions, no vessels or lobular architecture were detectable and contrast enhancement was absent in lymphatic malformations. CONCLUSION: A reliable differentiation between hemangiomas, venous and lymphatic malformations in childhood is not possible by standard MR sequences alone. Contrast media may be helpful as lymphatic malformations show no contrast enhancement. The main role of MR imaging is to determine the local extent or infiltration of deeper tissue layers and narrow the differential diagnosis of other soft tissue tumors.

Adolescent↗

PubMed2000

[Violence in the school--an analysis and prevention].

The "Forschungsgruppe Schulevaluation" (Research Group for School Evaluation, Technical University of Dresden) conducted several empirical investigations which led to rich knowledge concerning the amount of violence in schools, the different forms of violence, roles that actors of and sufferers from violent action play and the causes for violence. Besides the wellknown socialisatory influence of families, media consumption and peers for the formation of violent behaviour of pupils and of behaviour that has an affinity to violence a causal influence of schools was detected. Questions concerning the prevention of violence, the conducting of pilot studies on the latter point in one single school as well as the evaluation of the preventory measures taken were important points in our work. In the present study we will present the most important empirical results and our experience with the prevention of violence.

Adolescent↗

PubMed1999

[Diagnostic imaging of the kidneys and the urinary tract in children].

Imaging flow charts differ in pediatric and general radiology. The reasons are: different illnesses, different consequences arising out of imaging results and different sequence of imaging methods. Ultrasound is always the first imaging method of the urinary tract in infancy and childhood starts with ultrasound with the exception of severe abdominal trauma which is investigated by computer-tomography. The decision "normal or abnormal" is possible using ultrasound in the most pediatric cases. The diagnostic value and significance of ultrasound in infancy and childhood is far better than in general radiology because of the higher resolution of the high-frequency units taken. The result of the ultrasound examination should be the basis for the following imaging procedures. We will describe diagnostic flow charts starting with three important clinical symptoms: Prenatal pathology, urinary tract obstruction and urinary tract infection.

Age Factors↗

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↗