Outcome groups and a practical tool to predict success of shock wave lithotripsy in daily clinical routine.

PURPOSE: To improve outcome prediction of extracorporeal shock wave lithotripsy (SWL) by development of a model based on easily available clinical and radiographical predictors and suitable for daily clinical use. MATERIALS AND METHODS: We evaluated predictive factors for SWL success in 517 consecutive patients suffering from urinary calculi who underwent SWL between 2010 and 2018. Analyses included descriptive statistics, receiver operating characteristic statistics and logistic regression. Predictive value was improved by combining parameters using model selection and recursive partitioning. RESULTS: Of the 517 patients, 310 (60.0%) had a successful SWL. Best individual predictor of SWL success was mean attenuation (MAV), with an area under the curve (AUC) of 0.668, and an optimal cutpoint (OC) of 987.5 HU. The best multivariable model, including MAV, stone size, skin to stone distance (SSD), presence of an indwelling stent, and four interaction effects, yielded an AUC of 0.736. Recursive partitioning would categorize patients into three outcome groups with high (76.9%), intermediate (41%) and low (10%) success probability. High probability of SWL success (76.9%) was found for patients with a stone with MAV ≤ 987 HU or with MAV > 987 HU but stone size ≤ 11 mm and SSD (45°) ≤ 88 mm. CONCLUSION: A model based on four established predictors, and provided as an Excel®-Tool, can clearly improve prediction of SWL success. In addition, patients can be classified into three defined outcome groups based on simple cutpoint combinations. Both tools improve informed decision-making in daily clinical practice and might reduce failure rates.

Prevalence of nosocomial pathogens in German ambulances: the SEKURE study.

OBJECTIVE: The increasing prevalence of multidrug resistant bacteria is a problem in the inpatient care setting, and in the emergency care system. The aim of this observational, cross-sectional study was to evaluate the prevalence of pathogens on well-defined surfaces in German ambulances that have been designated as 'ready for service'. METHODS: After informed consent was obtained, ambulance surfaces were sampled with agar plates for microbiological examination during an unannounced visit. A standardised questionnaire was used to obtain information regarding the disinfection protocols used at each rescue station. RESULTS: Methicillin resistant staphylococcus aureus contamination was present in 18 sampling surfaces from 11 out of 150 ambulance vehicles (7%) that were designated as ready for service. Contact surfaces directly surrounding patients or staff were most frequently contaminated with pathogens. However, bacterial contamination was not related to annual missions, methods or frequency of disinfection. CONCLUSIONS: In accordance with previous studies, disinfection and cleaning of areas with direct contact to patients or staff seem to be the most challenging. This should also be reflected in disinfection guidelines and the related continuing education.

[Computed tomography for imaging of pediatric congenital heart disease]. / Die Computertomographie bei der Bildgebung von Kindern mit kongenitalen Herzvitien.

Congenital heart diseases are the most common congenital abnormalities of development. In general, echocardiography and cardiac catheter angiography are considered the gold standard for the evaluation of congenital heart disease. Cardiac magnetic resonance imaging has become an important supplementary imaging modality because of its ability to provide an accurate morphological and functional evaluation. The role of cardiac computed tomography in the imaging of patients with congenital heart disease is becoming increasingly more important due to the development of low radiation dose protocols and improvements in the spatial and temporal resolution. In the preoperative depiction and follow-up after surgical repair of congenital heart diseases, cardiac computed tomography provides detailed information of the heart, the venous and arterial pulmonary circulation as well as systemic arteries. This article reviews the technical aspects of cardiac CT and the modification of examination protocols according to the expected pathology and patient age. The potentials and limitations of the various radiation dose reduction strategies are outlined.

Densitometry for assessment of effect of lung volume reduction surgery for emphysema.

To explore if change in the extent of emphysema correlated with change in lung function, the effect of resection of emphysematous tissue was studied by computed tomography (CT) densitometry. In addition, the current authors studied how surgery-induced change in emphysema related to lung density in control subjects. In total, 30 patients (14 females; mean+/-sd age 59+/-10 yrs) with severe emphysema before and 3 months after lung volume reduction surgery (LVRS), 48 patients with moderate emphysema and 76 control subjects were investigated. Lung density (15th percentile point) of both lungs and heterogeneity of lung density between 12 isovolumetric partitions in each lung were calculated from chest CT images. The 15th percentile point and its heterogeneity could distinguish controls from subjects with moderate emphysema with a sensitivity and specificity of >95%. LVRS significantly increased lung density by 5.0+/-10.9 g.L(-1) (n=30). Improvement in the diffusing capacity of the lung for carbon monoxide and in residual volume significantly correlated with an increase in lung density (n=20 and 28, respectively). Change in forced expiratory volume in one second did not correlate with change in lung density. In conclusion, lung density 15th percentile point is a valuable surrogate marker for detection of both the extent of and reduction in emphysema.

Downstaging colorectal liver metastases by concomitant unilateral portal vein ligation and selective intra-arterial chemotherapy.

BACKGROUND: Although selective intrahepatic arterial chemotherapy successfully downstaged irresectable colorectal liver metastases in a previous study, curative resection was rarely possible, as the remnant healthy liver volume was inadequate. This pilot study evaluated the efficacy of concomitant unilateral portal vein ligation and selective intrahepatic arterial chemotherapy in downstaging such tumours. METHODS: The study included 11 patients with irresectable colorectal liver metastases. Selective intrahepatic arterial chemotherapy was delivered using a subcutaneous pump, and each patient underwent concomitant unilateral portal vein ligation of the hemiliver judged to have the higher tumour load. Chemotherapy involved serial administration of floxuridine for 2 weeks every 4 weeks. RESULTS: All patients developed significant atrophy of the hemiliver subjected to portal vein ligation and contralateral hypertrophy. There was no increase in tumour load within 6 months of therapy, and the load decreased by 60 per cent in the hemiliver ipsilateral to the ligated vein. At 3 months, six of 11 patients showed a significant response to chemotherapy. In four patients, downstaging allowed curative resection after only three cycles of chemotherapy. These patients survived at least 20 months afterwards. CONCLUSION: Combined unilateral portal vein ligation and selective intrahepatic arterial chemotherapy produced substantial atrophy of the ipsilateral hemiliver along with contralateral hypertrophy, without increased tumour growth in the regenerating hemiliver.

Coronal ultra-thick multiplanar CT reconstructions (MPR) of the pelvis in the multiple trauma patient: an alternative for the initial conventional radiograph.

PURPOSE: Multiple trauma patients with clinically suspected pelvic fractures often directly undergo a CT scan. However, the initial portable pelvis film (PPF) for further follow-up is then not available. This study examines whether coronal ultra-thick multiplanar reconstructions from CT data are similar when compared with the initial PPF, thus having the potential to serve as an alternative baseline image. MATERIALS AND METHODS: Initial PPF and coronal ultra-thick multiplanar CT reconstructions of 33 multiple trauma patients with pelvic fractures were retrospectively analyzed by two independent radiologists with regard to image quality, visualization of anatomical landmarks, and diagnostic accuracy. The primary diagnosis of pelvic fractures was made by using thin axial CT images and thin slice coronal and sagittal reconstructions and served as the standard of reference. RESULTS: Coronal ultra-thick multiplanar CT reconstructions were superior to PPF regarding image adjustment (p < 0.02), absence of overlaying structures (p < 0.05), and overall image quality (p < 0.01). Visualization of most anatomical landmarks was similar with both modalities, except of the iliosacral joint and acetabular lines which were more accurately depicted on ultra-thick multiplanar CT reconstructions (p < 0.05). Diagnostic accuracy of coronal ultra-thick CT reconstructions was similar to PPF regarding most fracture types, except of a higher accuracy of coronal ultra-thick CT reconstructions for iliosacral joint and acetabular column fractures (p < 0.05). CONCLUSION: Coronal ultra-thick multiplanar CT reconstructions of the pelvis provide similar image quality and diagnostic accuracy compared to PPF and are therefore suited as alternative baseline image in multiple trauma patients who directly undergo CT.

[Diagnostic assessment of painless microhematuria: prospective study comparing image quality, assessibility and diagnostic certainty of multidetector-row CT and intravenous pyelography within a single examination]. / Diagnostische Abklärung der schmerzlosen Mikrohämaturie: Prospektive Studie zum Vergleich von Bildqualität, Beurteilbarkeit und diagnostischer Sicherheit von MDCT und IVU in einem Untersuchungsgang.

PURPOSE: The purpose of this study is to prospectively compare intravenous pyelography (IVP) and combined unenhanced and excretory phase multidetector-row CT (MDCT) with respect to image quality, diagnostic certainty and diagnostic concordance with the final clinical diagnosis in patients with painless microhematuria. MATERIALS AND METHODS: Unenhanced MDCT, IVP and excretory phase MDCT were performed in 59 consecutive patients (21 women, 38 men, mean age 56 +/- 19 years, range 23 - 83 years) with painless microhematuria of unknown origin during a single examination with a single contrast media application (100 ml, non-ionic iodinated contrast media). Images were assessed by two experienced urogenital radiologists in consensus for image quality, diagnostic certainty of stone detection, obstruction, parenchymal lesions and morphological distinctive features. Imaging diagnoses of MDCT and IVP were compared with the final clinical diagnoses. In case of failure to detect an relevant pathology, the final clinical diagnosis was established after a mean follow-up period of 18 +/- 6 months (10 months to 2 years). Costs and radiation exposure of IVP and MDCT were compared. RESULTS: MDCT scan performed better than IVP in terms of image quality for all regarded variables. Image quality of MDCT was rated in all parameters as very good or good; the image quality of IVP differed in a wide range. MDCT and IVP reached a sensitivity of 100 % and 50 % for stone detection (n = 14, p = 0.008), respectively. Two bladder stones were not detected by IVU but correctly seen with MDCT. MDCT and IVP were unsatisfactory for detecting transitional cell carcinomas (n = 4, 2 of 4 detected with MDCT, 0 of 4 detected with IVU). One false positive transitional cell carcinoma was detected with IVP, none with MDCT. Additional relevant pathological changes (one teratoma, one abdominal aortic aneurysma and one abscess) were detected using MDCT but missed with IVP. In 38 of 59 patients (64 %) imaging and clinical follow-up over up to 24 months did not reveal any pathology to explain the microhematuria. The costs of the IVP (283 Euro) were lower compared with non-enhanced MDCT (380 Euro) or combined non-enhanced and contrast-enhanced MDCT (560 Euro). The radiation exposure was 23 - 27 mSv for MDCT and 2.3 mSv for IVP. CONCLUSION: MDCT performed better regarding image quality, subjective diagnostic certainty and diagnostic results with respect to stone detection. Since urolithiasis is a frequent cause of painless microhematuria MDCT is recommended as the initial imaging modality rather than IVU.

[Application of multislice spiral CT (MSCT) in multiple injured patients and its effect on diagnostic and therapeutic algorithms]. / Einsatz der Mehrschicht-Spiral-CT beim traumatologischen Notfall und ihre Auswirkungen auf den Untersuchungs- und Behandlungsalgorithmus.

The initial diagnostic work-up of trauma victims with multiple injuries is currently a combination of conventional radiography (CR), ultrasound (US), and computed tomography (CT). This article reviews the diagnostic quality of the different imaging modalities regarding detection and classification of injuries. CT performs better than US in detecting traumatic lesions of abdominal parenchymal organs. Furthermore, CT is better than CR in detecting therapeutically relevant chest and bone injuries. MSCT may replace CR and US under the condition that it is faster than or at least as fast as the conventional approach to diagnose life threatening injuries. This can be achieved only by changing the work-flow for the entire trauma team including radiologist. Furthermore, certain prerequisites must be fulfilled including integration of a MSCT scanner into the emergency room. An optimized whole body CT protocol for the assessment of trauma victims using MSCT as well as a two-step algorithm for reporting the imaging findings depending on their clinical significance is presented.

Atom fiber for omnidirectional guiding of cold neutral atoms.

We present an omnidirectional matter waveguide on an atom chip. The guide is based on a combination of two current-carrying wires and a bias field pointing perpendicular to the chip surface. Thermal atoms are guided for more than two complete turns along a 25-mm-long spiral path (with curve radii as short as 200 microm) at various atom-surface distances (35-450 microm). An extension of the scheme for the guiding of Bose-Einstein condensates is outlined.

Thrombosis of a superior mesenteric vein aneurysm: transarterial thrombolysis and transhepatic aspiration thrombectomy.

We report the case of a 31-year-old woman presenting with abdominal pain due to acute thrombosis of a superior and inferior mesenteric vein aneurysm, which was treated by a combination of arterial thrombolysis and transhepatic thrombus aspiration. At the last follow-up CT, 21 months following this procedure, there was no evidence of rethrombosis, and the patient continues to do well under oral anticoagulation. The literature regarding these uncommon mesenteric vein aneurysms without portal vein involvement, as well as their treatment options, is reviewed.

Retrospectively ECG-gated multi-detector row CT of the chest: does ECG-gating improve three-dimensional visualization of the bronchial tree?

PURPOSE: To determine the impact of retrospectively ECG-gated multi-detector row CT (MDCT) on three-dimensional (3D) visualization of the bronchial tree and virtual bronchoscopy (VB) as compared to non-ECG-gated data acquisition. MATERIALS AND METHODS: Contrast-enhanced retrospectively ECG-gated and non-ECG-gated MDCT of the chest was performed in 25 consecutive patients referred for assessment of coronary artery bypass grafts and pathology of the ascending aorta. ECG-gated MDCT data were reconstructed in diastole using an absolute reverse delay of - 400 msec in all patients. In 10 patients additional reconstructions at - 200 msec, - 300 msec, and - 500 msec prior to the R-wave were performed. Shaded surface display (SSD) and virtual bronchoscopy (VB) for visualization of the bronchial segments was performed with ECG-gated and non-ECG-gated MDCT data. The visualization of the bronchial tree underwent blinded scoring. Effective radiation dose and signal-to-noise ratio (SNR) for both techniques were compared. RESULTS: There was no significant difference in visualizing single bronchial segments using ECG-gated compared to non-ECG-gated MDCT data. However, the total sum of scores for all bronchial segments visualized with non-ECG-gated MDCT was significantly higher compared to ECG-gated MDCT (P < 0.05). The summary scores for visualization of bronchial segments for different diastolic reconstructions did not differ significantly. The effective radiation dose and the SNR were significantly higher with the ECG-gated acquisition technique (P < 0.05). CONCLUSION: The bronchial tree is significantly better visualized when using non-ECG-gated MDCT compared to ECG-gated MDCT. Additionally, non-ECG-gated techniques require less radiation exposure. Thus, the current retrospective ECG-gating technique does not provide any additional benefit for 3D visualization of the bronchial tree and VB.

Time-effectiveness, observer-dependence, and accuracy of measurements of left ventricular ejection fraction using 4-channel MDCT.

PURPOSE: To evaluate the time-effectiveness, inter-observer variance, and accuracy of left ventricular ejection fraction (EF) measurements using retrospectively ECG-gated four-channel multi-detector row CT (MDCT) angiography in comparison with biplane cine-ventriculography. MATERIALS AND METHODS: Twenty consecutive patients underwent retrospectively ECG-gated MDCT angiography and conventional coronary angiography with biplane ventriculography. Raw MDCT data were reconstructed at 0 % - 90 % of the cardiac cycle in increments of 10 %. Ten geometrically identical multiplanar reformations parallel to the short axis of the heart were reconstructed in each patient. Three blinded readers segmented the left ventricle in the end-systolic and end-diastolic phase using standardized window settings in order to determine the EF. The EF was measured with biplane cine-ventriculography by two blinded readers and was compared with MDCT. The time needed for post-processing was recorded and the inter-observer agreement for both imaging techniques was assessed. RESULTS: Mean post-processing time was 63 +/- 3 min per patient for MDCT and 5.5 +/- 1.2 min for ventriculography. MDCT and ventriculography showed a good correlation (r = 0.83, p < 0.0001) for measurement of the EF. Mean errors of EF measurements for the three MDCT readers compared with the mean of the ventriculography were - 6.3 +/- 6.6 %, - 4.7 +/- 7.1 % and - 4.6 +/- 5.7 %, respectively. The mean differences between the three readers assessing MDCT were - 1.6 +/- 3.2 % (reader 1 versus 2, r = 0.96), - 1.6 +/- 5.6 % (1 versus 3, r = 0.95) and - 0.011 +/- 2.9 % (2 versus 3, r = 0.97, p < 0.0001). The mean differences between the two readers assessing ventriculography was 0.32 +/- 5.1 % (r = 0.88, p < 0.0001). CONCLUSIONS: MDCT correlates well with biplane cine-ventriculography but has the tendency to underestimate the left ventricular EF. Measurements using MDCT have a high inter-observer agreement, however, the time needed for additional MDCT data post-processing is still unacceptably long.

Multi-detector row CT: effect of iodine dose reduction on hepatic and vascular enhancement.

PURPOSE: To evaluate the impact of different iodine concentrations of intravenous contrast agent on hepatic and vascular enhancement during arterial and porto-venous phase imaging using a 4-channel multi-detector row CT (MDCT). MATERIAL AND METHODS: One hundred consecutive patients referred for triphasic abdominal MDCT were randomly assigned into four groups receiving different iodine concentration (200, 250, 300 or 350 mg/ml). Non-contrast, arterial, and porto-venous phase 4-channel MDCT imaging was performed (VolumeZoom, Siemens, Germany). A fixed volume of 150 ml intravenous contrast agent at a rate of 3 ml/s was injected using an automatic bolus-tracking system (Care Bolus, Siemens, Erlangen). Hepatic and vascular enhancement values were measured over time and non-contrast values were subtracted in order to compute arterial and porto-venous mean hepatic (MHE) and mean aortic (MAE) enhancement for each group. Mean change of enhancement > 80 HU for the aorta and > 40 HU for the liver during porto-venous phase imaging was considered as sufficient enhancement. RESULTS: All groups achieved sufficient vascular enhancement during arterial phase imaging; MAE with 350 mg/ml (222 HU) and 300 mg/ml (213HU) was significantly better than with 250 mg (196HU) and 200 mg/ml (169 HU), whereas MHE showed no statistically significant difference between the groups (range 16 - 25 HU). Porto-venous MHE showed increased enhancement with larger concentrations, with significant differences among the groups. Only the higher concentration groups (350 mg/ml und 300 mg/ml) fulfilled in every individual the guidelines for sufficient porto-venous MHE. In the lower concentration groups, 8 patients with 200 mg/ml and 3 patients with 250 mg/ml showed enhancement values below the required minimum. CONCLUSION: A decrease in iodine contrast agent down to 200 mg/ml concentration is only tenable for propose of vascular aortic and hepatic arterial enhancement, whereas hepatic porto-venous phase imaging still requires concentrations at or above the level of 300 mg/ml.

Trapping and manipulating neutral atoms with electrostatic fields.

We report on experiments with cold thermal (7)Li atoms confined in combined magnetic and electric potentials. A novel type of three-dimensional trap was formed by modulating a magnetic guide using electrostatic fields. We observed atoms trapped in a string of up to six individual such traps, a controlled transport of an atomic cloud over a distance of 400 microm, and a dynamic splitting of a single trap into a double well potential. Applications for quantum information processing are discussed.

[Embolization of the splenic artery after splenic gunshot wound]. / Embolisation der Milzarterie nach Schussverletzung der Milz.

Computed tomography (CT) of the abdomen is a reliable method for evaluation of spleen injuries and has the potential to exclude further abdominal injuries. Blunt and penetrating injuries of the spleen have to be managed immediately due to a high mortality rate. Two therapeutical options, conservative or operative, are currently available. In general, a hemodynamic stable patient, no further injuries of the abdominal organs or the skull as well as no history of abdominal surgery of the abdomen are prerequisites for a non-surgical therapy. Catheter-based angiography gives the possibility to diagnose and to treat injuries of blood vessels of the spleen, which were seen on the CT scans. Gunshots are relatively rare in Europe, but the mortality of such traumas is high. The present case demonstrates a patient with a penetrating gunshot trauma of the left hemiabdomen with a bleeding injury of the spleen. Due to the stable hemodynamic conditions, absence of further injuries of the abdomen or the skull and, because of previous pancreas surgery a non-surgical therapy was chosen, consisting of proximal embolisation of the splenic artery.

Feasibility and potential of MR-Colonography for evaluating colorectal cancer.

BACKGROUND: MR-Colonography (MRC) based on MR-imaging is a relatively new diagnostic modality for diagnosing colorectal polyps. The aim of this experimental study was to evaluate its performance in detecting and staging colorectal cancer. METHOD: 23 patients with proven colorectal cancer underwent MR-Colonography one day prior to operation after standard bowel preparation. The colon was filled with a diluted gadolinium enema. Coronal sections were acquired in prone and supine. Virtual colonoscopy (VC) was processed from the acquired 3D data sets and MRC was interactively analysed together with VC. The findings were correlated with colonoscopic and pathology results. RESULTS: A complete MRC was achieved in 21 patients (92%), two patients (8%) could not be conclusively evaluated due to insufficient bowel preparation or technical problems. No complications were observed. Compared to colonoscopy all 23 carcinomas were detected. No lesion > or = 8 mm was missed. In one patient a synchronous carcinoma was newly diagnosed. This lesion was missed by colonoscopy since the distal tumour was endoscopically unpassable. In total eight (33%) colonoscopies were incomplete. CONCLUSION: MRC offers a new and promising diagnostic tool for colorectal cancer. It is particularly valuable when colonoscopy is incomplete. It improves preoperative planning and it holds the potential as an all-in-one investigation including local and liver staging in combination with conventional MRI.

Juvenile granulosa cell tumor.

We present three-dimensional computed tomographic findings of a juvenile granulosa cell tumor of the ovary at FIGO stage IA in a 17-year-old woman. Juvenile granulosa cell tumor is one of the rare sex cord stromal tumors of the ovary. Most tumors at FIGO stage IA have a favorable prognosis, whereas those at higher stages have a less favorable outcome.