[Diagnostic value of a plain radiograph of the chest in suspected tracheobronchial foreign body aspiration in children]. / Diagnostische Wertigkeit der Röntgenthoraxaufnahme bei tracheobronchialen Fremdkörpern im Kindesalter.

BACKGROUND: It is not well known how specific experience in paediatric radiology and the radiological technique influence the diagnostic yield of a plain radiograph of the chest when a paediatric foreign body aspiration (FB) is suspected. METHODS AND PATIENTS: 319 radiographs were retrospectively evaluated by a paediatric radiologist, a radiologist in paediatric radiology training and an experienced paediatrician with respect to the probability of a tracheobronchial FB (216 children with proven FB, 103 children without FB but with symptoms compatible with FB). RESULTS: 1) Sensitivity was highest for the radiologist compared to the two other subspecialists (70.8 vs. 59.5 % paediatric radiologist; 56.8 % paediatrician). The specifity was highest for the paediatrician and the paediatric radiologist (77.7 and 73.8 %; 62.2 % radiologist). Correctness as well as positive and negative predictive value were not significantly different. 2) The impact of technical quality correlated with the degree of radiological experience, but use of the expiratory phase in general did not increase the sensitivity. CONCLUSIONS: Even profound experience in paediatric radiology does not improve the limited diagnostic value of a plain radiograph of the chest in case of a suspected FB. Radiological training compensates for incorrect patient alignment. An expiratory phase image is not necessary.

Contralateral cerebral blood flow velocity changes after intracarotid amobarbital injection.

BACKGROUND AND PURPOSE: The intracarotid amobarbital procedure (IAP) leads to a prompt decrease in ipsilateral middle cerebral artery (MCA) mean blood flow velocity (MFV). Little is known about contralateral MFV changes. METHODS: The authors investigated bilateral MCA MFV using transcranial Doppler sonography (TCD) in 8 patients with epilepsy undergoing IAP. Measurements were excluded from analysis if angiography revealed any signs of interhemispheric cross-flow. RESULTS: With in 64 seconds after amobarbital injection, ipsilateral MFV decreased to a mean of 44.4% +/- 7.5% of baseline value (P < .01). In the absence of interhemispheric cross-flow and within 68 seconds, contralateral MFV decreased to 83.1% +/- 7.9% (P < .01). CONCLUSIONS: The observed decrease of contralateral MFV was not caused by amobarbital cross-perfusion. A possible underlying mechanism may be interhemispheric deafferentation.

Identification of interaction domains of the prion protein with its 37-kDa/67-kDa laminin receptor.

Cell-binding and internalization studies on neuronal and non-neuronal cells have demonstrated that the 37-kDa/67-kDa laminin receptor (LRP/LR) acts as the receptor for the cellular prion protein (PrP). Here we identify direct and heparan sulfate proteoglycan (HSPG)-dependent interaction sites mediating the binding of the cellular PrP to its receptor, which we demonstrated in vitro on recombinant proteins. Mapping analyses in the yeast two-hybrid system and cell-binding assays identified PrPLRPbd1 [amino acids (aa) 144-179] as a direct and PrPLRPbd2 (aa 53-93) as an indirect HSPG-dependent laminin receptor precursor (LRP)-binding site on PrP. The yeast two-hybrid system localized the direct PrP-binding domain on LRP between aa 161 and 179. Expression of an LRP mutant lacking the direct PrP-binding domain in wild-type and mutant HSPG-deficient Chinese hamster ovary cells by the Semliki Forest virus system demonstrates a second HSPG-dependent PrP-binding site on LRP. Considering the absence of LRP homodimerization and the direct and indirect LRP-PrP interaction sites, we propose a comprehensive model for the LRP-PrP-HSPG complex.

The 37-kDa/67-kDa laminin receptor acts as the cell-surface receptor for the cellular prion protein.

Recently, we identified the 37-kDa laminin receptor precursor (LRP) as an interactor for the prion protein (PrP). Here, we show the presence of the 37-kDa LRP and its mature 67-kDa form termed high-affinity laminin receptor (LR) in plasma membrane fractions of N2a cells, whereas only the 37-kDa LRP was detected in baby hamster kidney (BHK) cells. PrP co-localizes with LRP/LR on the surface of N2a cells and Semliki Forest virus (SFV) RNA transfected BHK cells. Cell-binding assays reveal the LRP/LR-dependent binding of cellular PrP by neuronal and non-neuronal cells. Hyperexpression of LRP on the surface of BHK cells results in the binding of exogenous PrP. Cell binding is similar in PrP(+/+) and PrP(0/0) primary neurons, demonstrating that PrP does not act as a co-receptor of LRP/LR. LRP/LR-dependent internalization of PrP is blocked at 4 degrees C. Secretion of an LRP mutant lacking the transmembrane domain (aa 86-101) from BHK cells abolishes PrP binding and internalization. Our results show that LRP/LR acts as the receptor for cellular PrP on the surface of mammalian cells.

Three-dimensional reconstructed rotational digital subtraction angiography in planning treatment of intracranial aneurysms.

We evaluated three-dimensional (3D) reconstructions of 200 degrees rotational digital subtraction angiography (DSA) images for their contributions to improving the safety of endovascular embolization of intracranial aneurysms. Standard DSA and 200 degrees rotational DSA were performed in 40 adult patients (aged 21-77 years) with 45 intracranial aneurysms. Information obtainable from standard DSA and 3D-DSA images about aneurysm shape and size was compared. In 40 (89%) of the 45 aneurysms 3D-DSA gave additional information about the anatomy of the aneurysm. In 17 (43 %) of these cases aneurysm anatomy could be visualized better on 3D-DSA than on standard DSA images. In three cases only 3D-DSA images showed blood vessels originating from the aneurysm. Reconstructed 3D images were also helpful in visualizing partially clipped aneurysms. On maximum-intensity projection images it was even possible to depict previously embolized aneurysms. Blood vessels originating from the aneurysm are visible on 3D-DSA images, and even previously clipped aneurysms can be visualized well. Rotational DSA with 3D reconstruction is a helpful tool in the assessment of intracranial aneurysms.

[Epidemiologic and serologic studies of pneumococcal infections with reference to the new STIKO recommendations]. / Epidemiologische und serologische Untersuchungen von Pneumokokken-Infektionen im Hinblick auf die neuen STIKO-Empfehlungen.

Pneumococcal diseases play an important role especially for babies and toddlers (otitis media) and for older persons (pneumonia). 28% of the 481 reported cases of bacterial meningitides (without meningococcus) in Mecklenburg-Vorpommern were caused by pneumoniae streptococcus. A pneumococcus antibody study by the land register confirms the high contamination in older people. Therefore STIKO recommends since March 1998 to effect pneumococcal vaccination with every person from the age of 60 and dove as well as for children, adolescents and adults with higher risk due to a primary disease.

MR angiography versus color Doppler sonography in the evaluation of renal vessels and the inferior vena cava in abdominal masses of pediatric patients.

OBJECTIVE: Involvement of renal vessels and the inferior vena cava (IVC) plays a decisive role during operative planning for removal of abdominal masses in pediatric patients. Advantages and limitations of MR angiography and color Doppler sonography for determining these factors were evaluated. MATERIALS AND METHODS: MR angiography and color Doppler sonography were performed preoperatively in 42 neonates, infants, and children with abdominal masses and were compared with spin-echo MR imaging and with surgical findings. Variables evaluated were anatomic variants, vessel displacement, patency of vessels, collateral circulation, and intravascular tumor extension. Quality of vessel visualization was assessed in vessels not affected by tumor. RESULTS: In 88% of unaffected renal vessels, the entire vessel course could be visualized on MR angiography compared with 58% on color Doppler sonography and 43% on spin-echo MR imaging. In four of nine cases, color Doppler sonography revealed an accessory renal artery, whereas MR angiography revealed these variants in seven of nine cases. MR angiography showed 79% and color Doppler sonography 66% of displaced vessels. Unlike MR angiography, color Doppler sonography did not reveal five stenotic renal veins because they could not be completely imaged. In two cases, however, MR angiography falsely indicated an occlusion of the IVC, whereas color Doppler sonography showed residual flow. CONCLUSION: Anatomic variants, vessel displacement, collateral circulation, and neoplastic vessel infiltration were revealed more accurately by MR angiography than by color Doppler sonography. In cases in which patency of the IVC is unclear on MR angiography, color Doppler sonography should also be performed.

A computer-based reporting system in radiology of the chest.

The aim of this study was to compare our computer-aided report writing system to standard techniques. A computer-aided reporting system for reporting on chest X-rays was developed and linked with a UNIX-based radiology information system. The reporting system consists of different text modules which can be composed to a complete radiological report. The quality of the report, the system's efficiency, flexibility and availability at the radiology information system (RIS), as well as its acceptance by the users, were criteria we took as a basis of evaluation. Acceptance and flexibility of the system were tested by assessing necessary changes and additions performed to text modules and by subjective evaluation. The time spent on working with the reporting system was evaluated by performing a time-analysis study comparing the new system to the two conventional methods, the tape system and handwriting. On average, the readers needed 22.6 text modules for each report. For the users the most important advantages of the new system are that primarily fewer changes to or additions to the text are necessary, and when they cannot be avoided they can be performed more easily. In comparison with the tape system and handwritten reports, it took on average two and a half to three times longer to report on a chest X-ray. The printed report had left the department within 6.4 h using the tape system within 0.4 h when handwritten and within 1.4 h when recorded by the reporting system. The completeness of the set of modules and the logical order were positively assessed by the users. The demand of time for reporting increases, but the final report is available sooner.

Brain hemangiomas of infancy. Sonographic detection and follow-up.

Vascular birthmarks of the skin can be associated with hemangiomas or arteriovenous malformations of different organs. Computed tomography and magnetic resonance imaging (MRI) combined with angiography are the diagnostic tools used in children, adolescents, and adults to depict vascular malformation or bleeding. In infants, ultrasound examination through the anterior fontanelle is possible. This report describes 2 mature infants with brain hemangiomas primarily detected by real-time sonography: In both the brain lesions were associated with cutaneous and other vascular birthmarks. MRI was used to verify the brain hemangiomas. Subsequent follow-up evaluations during therapy were easily performed by ultrasonography.

[The diagnostic value of digital and conventional imaging in intravenous urography]. / Diagnostische Wertigkeit digitaler und konventioneller Bildgebung bei intravenöser Urographie.

PURPOSE: To compare image quality of digital luminescence radiography with conventional film-screen techniques during excretion urography. Four field tests and ROC analysis for determining diagnostic value. MATERIAL AND METHOD: 135 patients were included in a prospective study. Three independent observers judged the five minute (59 cases) or ten minute (76 cases) films after contrast injection using digital images as well as corresponding conventional images (five minutes-76 cases, ten minutes-59 cases). RESULTS: The digital technique provided better information concerning the renal parenchyma, the soft tissues and bone structures. Contrast enhanced detail was demonstrated equally well by both systems. The two systems had similar sensitivity but digital radiography showed higher specificity.