Perkutane Entfernung eines intraperitonealen Fremdkörpers

1993

MR-Angiographie peripherer Gefäße mit automatischer Verschiebetisch-Technik bei 1.0 T im Vergleich zur i. a. DSA

1999

PURPOSE Contrast-enhanced (CE) 3D-MR angiography of peripheral arteries was performed in 8 patients with peripheral arterial occlusive disease by applying a new tracking technique on a 1.0 T system (Magnetom Harmony, Siemens). The studies were compared with intra-arterial digital angiography as gold standard. MATERIALS AND METHODS Imaging of the distal aorta, pelvis, upper and lower limb arteries was accomplished with a Flash-3D-sequence (TR/TE = 6.2/3.2 ms) within 26 s acquisition time of each region after a single bolus of 30 ml contrast agent. Individual circulation time was determined by a test bolus before each examination. RESULTS 112 vessel segments were evaluated. MR angiography ach…

Was heißt wie? Ansatz und Glossar zu Befundung und Verständnis in der HRCT der Lunge

1996

In HRCT reports multiple different, often synonymous, German and English terms are used. The variety of terms impede understanding and acceptance of HRCT. Purpose of this paper is to present a scheme, which is based on the anatomic landmarks (secondary lobule), and the density of pathologic changes, as well as a glossary from the German HRCT-literature, including suitable terms, definitions, synonyms and English terms. Low attenuation changes include emphysemas, air-filled cavities (bullae, cysts, cavitations, honeycombing) and bronchial dilatation, changes with increased density consist of diffuse (ground glass opacity, consolidation) and focal processes (reticular and nodular densities). …

Correction: Validation of Semantic Analyses of Unstructured Medical Data for Research Purposes.

2020

Retrograde Venenokklusion - Zur Therapie der verlogenen Impotenz

1993

Retrograde occlusion of penile drainage veins can produce improvement in patients with impotence due to venous leaks. We performed 50 transfemoral and three transjugular procedures; 46 (86%) were technically successful. Clinical improvement was found in 24 out of the 46 procedures (52%). In 20 patients spontaneous intercourse became possible, in four this occurred after intracavernous injection of vaso-active substances. In eleven patients there was deterioration after one to twenty months; in seven this was treated by repeated venous occlusion. In 13 patients improvement has been maintained over a period of one to thirty months (average 10.5 months). There were no complications.

Erfassung der relativen Häufigkeiten und Strahlendosen von Röntgenanwendungen in der pädiatrischen Radiologie

2018

CT-Angiographie bei arterieller Verschlußkrankheit: Vergleich von 3 Rekonstruktionsverfahren

1997

Purpose To evaluate different rendering techniques of CT data for the assessment of long vessel segments in peripheral vascular occlusive disease. Material and methods 40 CT angiograms (aortoiliac: n = 20, leg arteries: n = 20) were viewed using three different rendering techniques: 1, maximum intensity projection (MIP); 2, volume rendering (VR); 3, shaded surface display (SSD). CT angiograms were obtained in 6 or 8 projections. Axial cross-section images were analysed using an interactive cine mode. Intraarterial DSA was the standard in all cases. Results The sensitivities for the diagnosis of occlusive disease were 100% (cross-section images), 94% (MIP), 91% (VR) and 93% (SSD). The specif…

Validation of Semantic Analyses of Unstructured Medical Data for Research Purposes

2019

BACKGROUND: In secondary data there are often unstructured free texts. The aim of this study was to validate a text mining system to extract unstructured medical data for research purposes. METHODS: From a radiological department, 1,000 out of 7,102 CT findings were randomly selected. These were manually divided into defined groups by 2 physicians. For automated tagging and reporting, the text analysis software Averbis Extraction Platform (AEP) was used. Special features of the system are a morphological analysis for the decomposition of compound words as well as the recognition of noun phrases, abbreviations and negated statements. Based on the extracted standardized keywords, findings rep…

Phantomuntersuchung zur Optimierung der Spiral-CT und 3 D-Rekonstruktion des Tracheobronchialsystems

1996

PURPOSE To optimise three-dimensional spiral CT of the tracheobronchial tree using adequate acquisition and reconstruction parameters for spiral CT of the chest. MATERIAL AND METHODS Qualitative and quantitative assessment of different 3 D reconstructions of two test objects of the tracheobronchial tree depending on section thickness, reconstruction interval, pitch, and reconstruction algorithm used in spiral CT (Siemens, Somatom plus S) of the chest. The frequency of volume and stairstep artifacts was evaluated. The 3 D reconstructions were generated using a seeded VOI-technique (Allegro, ISG). RESULTS Reduction of artifacts was achieved by decreasing section thickness. Increasing overlap …

„Stent-in-Stent”

1993

Effectiveness of platinum wire microcoils for venous occlusion: A study on patients treated for venogenic impotence

1994

The purpose of this study was to determine the effectiveness of venous occlusions achieved by embolization with platinum microwire coils. Follow-up venographies in 19 patients, 1-20 months (average 8 months) after coil embolizations, were evaluated. Twenty-eight of 126 (22.2%) coil embolizations were found to be patent. Coils which had not formed or partially formed upon embolization had a patency/recanalization rate of 37.5% (12/32). Among coils which had formed nearly completely or completely only 16 of 95 (17%) showed venous patency. As coil embolization had been augmented by sclerotherapy in all patients, the effectiveness of long-term venous occlusion by platinum wire coils alone is pr…

The impact of irreversible image data compression on post-processing algorithms in computed tomography

2020

PURPOSE: We aimed to evaluate the influence of irreversible image compression at varying levels on image post-processing algorithms (3D volume rendering of angiographs, computer-assisted detection of lung nodules, segmentation and volumetry of liver lesions, and automated evaluation of functional cardiac imaging) in computed tomography (CT). METHODS: Uncompressed CT image data (30 angiographs of the lower limbs, 38 lung exams, 20 liver exams and 30 cardiac exams) were anonymized and subsequently compressed using the JPEG2000 algorithm with compression ratios of 8:1, 10:1, and 15:1. Volume renderings of CT angiographies obtained from compressed and uncompressed data were compared using objec…

CT-Angiographie an einem 16-Schicht-CT zur perioperativen Evaluation der Leberarterien im Vergleich zur MR-Angiographie

2004

Purpose: To evaluate the efficiency of CT angiography (CTA) with 16-row MSCT compared with MR angiography (MRA) in analyzing the arterial anatomy in patients undergoing liver surgery. Materials and Methods: In 30 patients, MRA and CTA studies of the abdominal vessels were reviewed. CT parameters: slice thickness 3 mm; collimation 1.5; reconstruction interval 2 mm (Philips MX 8000 IDT); 120 ml contrast media (400 mg/ml) at a rate of 4 ml/ sec; acquisition of arterial-phase scans. The anatomy of the hepatic artery was evaluated from axial and reconstructed maximum-intensity-projection (MIP) images ("Slab-Viewer", Philips). MR parameters: contrast-enhanced coronal FLASH-3D sequences; slice thi…

Bronchiektasen und Infekthäufigkeit bei Alpha-1-Antitrypsin-Mangel

1995

UNLABELLED PURPOSE of this study was to determine the prevalence of bronchiectasis in patients suffering from alpha-1-antitrypsin deficiency and to compare its extent with the frequency of infections. MATERIAL AND METHODS High-resolution CT examinations (HRCT) of 23 patients with alpha-1-antitrypsin deficiency were retrospectively assessed for extent, severity and localisation of bronchiectasis, bronchial wall thickening and extent of emphysema. Chest radiographs and clinical records were available for correlation. RESULTS HRCT scans showed bronchiectasis in 14 of 23 patients, bronchial wall thickening in 3/14, and panlobular emphysema in 23/23. Chest radiographs showed bronchiectasis in 4/…

Achalasie oder Pseudoachalasie? Fallstricke der Diagnostik und Therapieentscheidung

2007

History Patient 1 (female, aged 55 years) had for some time complained of morning nausea. She reported symptoms of reflux with regurgitation of food for two-and-a-half years and also dysphagia with retrosternal bolus obstruction for the last eighteen months. Patient 2 (male, aged 84 years) complained of restrosternal dysphagia with each intake of food for one year, weight loss of 12 kg and occasional regurgitation of food. Investigations The general condition of patient 1 was only slightly impaired but that of patient 2 markedly reduced. Routine laboratory tests were unremarkable in both. Barium meal in patient 1 revealed fixed narrowing in the region of the esophageal hiatus. The inferior …

Radiologisch assistierte perkutane Gastro-/Enterostomie - Retrospektive Analyse von 90 Eingriffen

1996

PURPOSE To analyse retrospectively the indications, technique and results of radiologically induced gastrostomies or enterostomies. PATIENTS AND METHOD Radiologically assisted gastrostomies or enterostomies were induced in 90 patients, mostly with high grade obstructions due to head and neck tumours or oesophageal tumours. 19/90 patients had had previous resection of the oesophagus or gastric operations. RESULTS A catheter was successfully introduced in all patients. In 11/90 patients this was followed by a two-stage procedure. In 16/90 patients puncture was performed under CT control because of some anatomical peculiarity. Serious complication occurred in 9/90 patients but in only one was …

Gadolinium-DTPA (Magnevist®) als Kontrastmittel für die arterielle DSA

1994

16 DSA investigations using intra-arterial Gd-DTPA were performed on 12 patients. The contrast medium was administered either as a 0.5 molar gadolinium solution (commercially available) or diluted with distilled water to a 0.2-0.4 molar gadolinium solution. The injection was made either by pressure injector or by hand. The aortic arch, abdominal aorta and pelvic and lower limb arteries were examined. 14 of the 16 procedures were diagnostically adequate, but compared with iodinated contrast materials, contrast was less marked. There were no cardiovascular, neurological or allergic side effects. Three patients suffered a feeling of heat and one patient had mild pain during the injection. Even…

The Public-Key-Infrastructure of the Radiological Society of Germany.

2005

Pretty Good Privacy (PGP) encoding is based on the Public-Key-Procedure and permits the safe transmission of medical data. Furthermore it allows the use of an electronic signature provided that keys used belong to the key owner and that the key owner's identity is guaranteed by a trusted third party. Under the auspices of the Radiological Society of Germany (Deutsche Rontgengesellschaft, DRG) its IT-Working Group (Arbeitsgemeinschaft fur Informationstechnik, @GIT) built up an appropriate Certification Authority including the required Public-Key-Infrastructure. These @GIT certified PGP keys allow the legal use of telemedicine in Germany. Digital signatures based to those certified keys corre…

Guidelines Regarding §16 of the German Transplantation Act - Initial Experiences with Structured Reporting.

2017

ZIEL:  Übertragung des Befundungsbogens aus den Richtlinien zum Transplantationsgesetz (TPG) in ein standardkonformes Befundtemplate und Evaluation in der klinischen Routine. Das Template wurde mit der frei verfügbaren Software brackets.io erstellt. Die Implementierung des Templates in die klinische Routine erfolgte mithilfe einer in Eigenentwicklung programmierten Befundungsplattform. Schnittstellen zu RIS und PACS erlaubten eine Integration in den gewohnten Befundungsworkflow. Die Evaluationsperiode erstreckte sich über 70 Tage. Die Erstellung des Templates für die Umsetzung der Richtlinien war ohne Schwierigkeiten möglich. Der vorgegebene Befundungsbogen wurde hierbei inhaltlich eins zu …

CT-Arthrographie der Schulter nach operativer Versorgung ventraler Instabilitäten

1991

25 patients who had undergone a modified Lange repair were examined postoperatively after about four years, both clinically and by CT arthrography. Ventral redislocation was no longer seen postoperatively. As regards residual ventral instability, there was agreement between CT arthrography and the clinical findings in 20/25 patients (90%). Newly developed or residual dorsal instability could be accurately demonstrated by the presence of pathological changes of the dorsal labrum and by the observation of a wide dorsal joint recess. CT arthrography did not provide reliable evidence concerning loss of function and mobility of the treated shoulder. However, the presence of marked capsular foldi…

International perspectives on radiology practice metrics: Australia, France, Germany, Japan, New Zealand, Spain, the UK and USA.

2014

INTRODUCTION The delivery of health care around the world is remarkably diverse in 2015. A comparison of the approximately 200 national entities on the planet reveals marked differences in national measures, both on the input side, such as health care spending, and in outcomes, such as life span. Using the percentage of gross domestic product as a metric for comparing health care spending, the current variation among nations is almost an order of magnitude, from the Marshall Islands and the United States at close to 20% to Myanmar at about 2% [1]. Outcomes are also highly variable, with an almost 2-fold difference in life span between the best and worst nations [2]. Within the nations repre…

Japanese Radiation Research Society

2017

Computed tomography (CT) is an essential tool in modern medicine and is frequently used to diagnose a wide range of conditions, particularly in industrial countries, such as Japan and Germany. However, markedly higher doses of ionizing radiation are delivered during CT imaging than during conventional X-ray examinations. To assess pediatric CT practice patterns, data from three university hospital databases (two in Japan and one in Germany) were analyzed. Anonymized data for patients aged 0 to 14 years who had undergone CT examinations between 2008 and 2010 were extracted. To assess CT practice, an interdisciplinary classification scheme for CT indications, which incorporated the most commo…

Unterscheiden sich die Erwartungen und Einstellungen zu Anwendungen der Künstlichen Intelligenz zwischen Radiologen und IT-Experten?

2020

Segmentierung von Hepatozellulären Karzinomen mit Fuzzy-Connectedness

2003

Die Segmentierung von hepatozellularen Karzinomen nach Chemoembolisation stellt eine grose Herausforderung an die Bildverarbeitung dar. CT-Aufnahmen sechs Wochen nach dieser Therapie sind die Grundlage fur die angestrebte Volumetrie der Raumforderungen. In diesen Bildern stellen sich die mit Lipiodol und Mitomycin behandelten Tumore als inhomogene, kraftig kontrastierte Herde dar, wahrend gleichzeitig neue Metastasen mit nur geringer Kontrastierung entstanden sein konnen. Ein neuer, auf Basis der Fuzzy-Connectedness beruhender Algorithmus zeigt in einer ersten Studie durch seine Fahigkeit, Grauwertinformationen mit Kriterien zu lokalen Zusammenhangen zu kombinieren, gute Ergebnisse. Verglei…

Duplexsonographie der normalen Pfortader

2008

In 50 normal subjects flow velocity and direction on the portal vein was measured by ultrasonic duplex system. The measurements revealed at a mean diameter of 9.7 mm, a mean flow velocity of 15.2 +/- 2.6 cm/s, corresponding to a volume flow of 693 +/- 235 ml/min. Postprandially this increased to 880 +/- 269 ml/min. Inter-observer and day to day measurements demonstrated good reproducibility. Thus, this simple non-invasive method is well suited for quantitative assessment of the portal vein system in portal hypertension, thrombosis or after shunt operations.

Multimodal Deep Learning for Prognosis Prediction in Renal Cancer

2021

BackgroundClear-cell renal cell carcinoma (ccRCC) is common and associated with substantial mortality. TNM stage and histopathological grading have been the sole determinants of a patient’s prognosis for decades and there are few prognostic biomarkers used in clinical routine. Management of ccRCC involves multiple disciplines such as urology, radiology, oncology, and pathology and each of these specialties generates highly complex medical data. Here, artificial intelligence (AI) could prove extremely powerful to extract meaningful information to benefit patients.ObjectiveIn the study, we developed and evaluated a multimodal deep learning model (MMDLM) for prognosis prediction in ccRCC.Desig…

Selektive Blutentnahme aus dem Sinus petrosus inferior: Vergleich von CRF- und TRH-Stimulation

1993

In 10 patients with hypophyseal Cushing microadenomas, selective bilateral sampling from the inferior petrosal sinuses was performed and the effect of stimulation by iv TRH and CRF was compared. On the side of the microadenoma. ACTH concentration rose from 650 +/- 242 pg/ml to 2712 +/- 843 pg/ml following injection of CRF and 2025 +/- 242 pg/ml after TRH. Contralateral values were 165 +/- 79 pg/ml, 490 +/- 200 pg/ml and 165 +/- 72 pg/ml respectively. Prolactin concentration on the side of the adenoma was 98 +/- 49 ng/ml before stimulation, 236 +/- 62 ng/ml after CRF and 747 +/- 168 ng/ml after TRH. Contralateral concentration was 22 +/- 10 ng/ml, 64 +/- 19 ng/ml respectively. Sampling local…

PACS infrastructure supporting e-learning

2011

Digital imaging is becoming predominant in radiology. This has implications for teaching support, because conventional film-based concepts are now obsolete. The IHE Teaching File and Clinical Study Export (TCE) profile provides an excellent platform to enhance PACS infrastructure with educational functionality. This can be supplemented with dedicated e-learning tools.

Stellenwert der Spirometertriggerung für die hochauflösende Computertomographie der Lunge in Inspiration und Exspiration

1998

PURPOSE To compare mean lung density (MLD) of paired inspiratory and expiratory thin-section CT scans acquired after patient instruction or using spirometric gating. MATERIALS AND METHODS 21 patients (13 m, 8 f. median age 59 years, two with normal lung function, 15 with obstructive, 4 with restrictive impairment) underwent thin-section CT. Paired inspiratory and expiratory scans were performed in the upper, middle and lower lung fields. They were acquired after automatic patient instruction with constant intervals between instruction and scan. Spirometrically gated scans were acquired within 4 days at 80% and 20% of vital capacity (VC) which has been determined on the CT scanner in supine …

Helical computed tomographyangiography: Technical considerations and clinical applications

1997

Abstract A combination of volume acquisition techniques (helical CT), dedicated protocolsfor bolus injections of contrast medium, and postprocessing modalities have paved the way for computed tomography (CT) angiography. To obtain optimum results the collimation must be adapted to the vascular territory of interest, and the reconstruction of overlapping source images from the volume data set is advantageous for further postprocessing. Strong intravascular opacification is indispensable for the evaluation of vascular abnormalities and pathology and is also helpful for image postprocessing, where different modalities can be applied: multiplanar reconstruction, maximum intensity projection, se…

Koronare Bypassdiagnostik mit CT und MRT - eine Bestandsaufnahme

2004

The limited lifetime and the correlation between graft occlusion and recurring symptoms underline the need for repeated imaging of coronary artery bypass grafts. CT and MRI allow for non-invasive imaging of coronary bypasses with high accuracies concerning the patency of these vessels. Multidetector CT seems to be the CT technique of choice, especially after the introduction of 16 slice CT scanners for morphologic assessment of coronary artery bypass grafts. Compared with MRI, CT is a robust technique for assessment of cardiac anastomoses, native coronary arteries, and for the detection of graft stenoses. MRI, however, is able to deliver functional information about the grafts and the recip…

Assessment of tumor microcirculation with dynamic contrast-enhanced MRI in patients with esophageal cancer: initial experience.

2008

PURPOSE: To investigate the feasibility and impact of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) on tumor characterization and response to radiochemotherapy (RCT) in patients with esophageal cancer. MATERIALS AND METHODS: A total of 48 patients underwent DCE-MRI to assess tumor microcirculation based on a two-compartment model function. Effects of RCT on kinetic parameters were studied in 12 patients with squamous cell carcinoma. RESULTS: Tumor microcirculation differs with respect to histological subtype: squamous cell carcinomas showed lower values of amplitude A (leakage space, P = 0.015) and higher contrast agent exchange rates (k(21), P = 0.225) compared with adenoc…

Leber-CT mit portal-venöser Kontrastmittelgabe

1987

Contrast administration through the superior mesenteric or splenic arteries provided additional information in 22 out of 31 patients, when compared with intravenous contrast bolus for CT of the liver. In 11 patients, the demonstration of a tumour lead to a change in treatment. False positive findings occurred in four of the 31 patients. In 2 patients intrahepatic lesions were overlooked, but were found during angiography carried out at the same examination. The diagnosis of intrahepatic space-occupying lesions is discussed as well as the CT appearances of portal-venous liver perfusion.

Duplexsonographie abdomineller Gefäße

1987

Duplex sonography is a non-invasive procedure which permits the determination of flow velocity and direction in visceral vessels. Results in 50 normals have shown that small arteries can be evaluated in about 50% of cases. The portal venous system can be demonstrated in all cases; average flow velocity and volume is 15.2 +/- 2.8 cm/s and 694 +/- 230 ml/min, corresponding with the values obtained by invasive methods. Clinical application for duplex examinations can be found in portal hypertension, varices, thromboses, aneurysms and transplant kidneys.

Multidetector Computed Tomography Angiography (MD-CTA) of Coronary Artery Bypass Grafts – Update 2017

2017

Coronary artery bypass grafting (CABG) is still an important therapeutic approach in the treatment especially of advanced coronary artery disease. In this study, we elucidate the current role of multidetector computed tomography angiography (MD-CTA) in imaging patients after CABG surgery.This study is based on recent reports in the literature (2007 - 2016) on imaging of CABG using 64-slice MD-CT scanners and beyond. We included 13 reports that compared ECG-gated MD-CTA with conventional invasive coronary angiography (ICA) as the reference standard for the assessment of graft patency and for the detection of 50 % stenoses. These studies had to provide absolute values for true-positive, true-…

Multi-Slice CT (MSCT) in Cardiac Function Imaging: Threshold-Value-Supported 3D Volume Reconstructions to Determine the Left Ventricular Ejection Fra…

2002

Evaluation eines neuen Softwareassistenten zur automatischen Volumenbestimmung von intrahepatischen Tumoren

2004

Purpose: Computed tomography has become the preferred method in detecting liver carcinomas. The introduction of spiral CT added volumetric assessment of intrahepatic tumors, which was unattainable in the clinical routine with incremental CT due to complex planimetric revisions and excessive computing time. In an ongoing clinical study, a new software tool was tested for the automatic detection of tumor volume and the time needed for this procedure. Materials and Methods: We analyzed patients suffering from hepatocellular carcinoma (HCC). All patients underwent treatment with repeated transcatheter chemoembolization of the hepatic arteria. The volumes of the HCC lesions detected in CT were m…

Diagnostik der primär sklerosierenden Cholangitis: prospektiver Vergleich von MR-Cholangiographie mit endoskopisch retrograder Cholangiographie

1998

PURPOSE To assess the accuracy of MR cholangiography (MRC) in the diagnosis of primary sclerosing cholangitis (PSC) in comparison to endoscopic retrograde cholangiography (ERC). METHOD 20 patients with PSC were examined by ERC and MRC (1.0 T, HASTE sequence). Visualization and pathologic changes of the extra- and intrahepatic bile ducts were evaluated with both methods. RESULTS Mural irregularities of the common bile duct were seen with MRC in 6/7 cases, stenoses and dilatation of the common bile duct were detected correctly in all patients. Diffuse, multifocal strictures of the intrahepatic bile ducts were the most common intrahepatic findings and correctly diagnosed in almost all patients…

Hochauflösende Computertomographie der Lunge bei neutropenischen Patienten mit Fieber

1996

Purpose To determine the sensitivity and clinical impact of high-resolution CT (HRCT) of the lung in febrile neutropenic patients under antibiotic therapy. Material and methods Chest X-ray and HRCT were prospectively performed to exclude pneumonia in 34 patients (53 examinations) suffering from febrile neutropenia following antitumor therapy. Diagnosis was confirmed by bronchoalveolar lavage or sputum cultures. Results Chest X-ray showed pneumonia in 13/53 examinations, in 12/13 a micro-organism was found. HRCT demonstrated pneumonia in 39/53, in 31/39 a micro-organism was found. All cases with positive cultures showed suspicious HRCT findings. Changes in antibiotic treatment resulted in fi…

An International Survey of Quality and Safety Programs in Radiology

2021

Purpose: The aim of this study was to determine the status of radiology quality improvement programs in a variety of selected nations worldwide. Methods: A survey was developed by select members of the International Economics Committee of the American College of Radiology on quality programs and was distributed to committee members. Members responded on behalf of their country. The 51-question survey asked about 12 different quality initiatives which were grouped into 4 themes: departments, users, equipment, and outcomes. Respondents reported whether a designated type of quality initiative was used in their country and answered subsequent questions further characterizing it. Results: The re…

Comparison of contrast-enhanced MR angiography to intraarterial digital subtraction angiography for evaluation of peripheral arterial occlusive disea…

2010

Purpose To evaluate the efficacy and safety of 0.1 mmol/kg gadodiamide administration for contrast-enhanced magnetic resonance angiography (CE-MRA) in detecting hemodynamically relevant main stenosis (ie, ≥50% or occlusion) of aortoiliac arteries. Materials and Methods In a multicenter, phase 3, controlled study, patients with suspected or proven peripheral arterial occlusive disease (PAOD) underwent CE-MRA with administration of gadodiamide. Intraarterial digital subtraction angiography (IA-DSA) was used as the reference. The study was approved by all Institutional Review Boards or Institutional Ethic Committees prior to commencement of patient recruitment and written informed consent was …

Magnetresonanztomographie (MRT) der Leber und des Gehirns bei hämatologisch-onkologischen Patienten mit Fieber unbekannter Ursache

1998

PURPOSE To examine the advantage of liver and brain MRI in clinically anomalous haematological patients with fever of unknown origin. MATERIAL AND METHODS Twenty liver MRI (T2-TSE, T2-HASTE, T1-FLASH +/- Gd dynamic) and 16 brain MRI (T2-TSE, FLAIR, T1-TSE +/- Gd) were performed searching for a focus of fever with a suspected organ system. Comparison with clinical follow-up. RESULTS A focus was detected in 11/20 liver MRI. Candidiasis (n = 3), mycobacteriosis (n = 2), relapse of haematological disease (n = 3), graft versus host disease (n = 1), non-clarified (n02). The remaining 9 cases with normal MRI were not suspicious of infectious hepatic disease during follow-up. In brain MRI, 3/16 sho…

Möglichkeiten der 16-Schicht-CT bei der linksventrikulären Funktionsbestimmung: Beurteilung zweier unterschiedlicher Software-Tools zur quantitativen…

2004

PURPOSE To determine global and regional left ventricular (LV) function from retrospectively gated multidetector row computed tomography (CT) by using two different semiautomated analysis tools and to correlate the results with those of magnetic resonance imaging (MRI). MATERIALS AND METHODS Nineteen patients (5 females, 14 males, mean age 69 years) underwent 16-slice spiral-CT (MS-CT) with standard technique without administration of beta-blockers for a decrease in the cardiac rate. Ten series of images were reconstructed at every 10 % of the RR-interval. With commercially available software capable of semiautomated contour detection, end-diastolic and end-systolic LV volumes (EDV and ESV)…

3D-CT von Frakturen: Vergleich von Volumen- und Oberflächen-Rekonstruktionen

1998

Purpose The comparison of volume rendering (VR) and surface rendering (SSD) for demonstrating fractures from spiral-CT data. Materials and methods Standardized VR and SSD projections were produced from 50 spiral CT scans of 50 consecutive patients with fractures. Appropriate multiplanar reformattings (MPR) were used as the standard. Results SSD provided sufficient information in 31/50 cases. Results of VR were not significantly different (33/50). VR was superior in demonstrating 6/7 craniofacial fractures and 3/3 calcaneal fractures. SSD was superior for visualizing 2/3 shoulder fractures and 2/2 elbow fractures. Conclusion VR is a flexible technique for the depiction of fractures and the a…

Fatal venous air embolism: proof and volumetry by helical CT

1995

Spiral-CT und 3 D-Rekonstruktion des Tracheobronchialbaumes zur Auswahl geeigneter Doppellumentuben vor Einzellungenbeatmung

1997

Purpose To assess the potential of 3-D spiral CT in the selection of adequate double-lumen tubes (DLT) for one-lung-ventilation. Materials and methods 3-D spiral CT of eight different DLTs was performed with standardized acquisition parameters: section thickness 4 mm, table speed 6 mm/s, increment 3 mm and standardised thresholds, window settings and magnification zoom. The accuracy was confirmed by measuring 3-D objects on screen and original DLTs by vernier caliper. 3-D spiral CT was performed in 20 patients preoperatively with slice thickness 4-8 mm, pitch 1-1.5, increment 4-8 mm. To select the adequate DLT size the 3-D reconstructions of the patient's tracheobronchial tree and of the DL…

Verwendung des DICOM- Standards in heterogener Umgebung

1999

Purpose The DICOM standard, introduced in 1993, is now established in many of today's image modalities. Experiences with DICOM implementations and requirements for future developments are described. Methods First a brief summary of the development of the DICOM standard is given. Based on general observations, different problems with installation, programming and maintenance are outlined. Results The standard consists of mandatory and optional information models and functionalities to enable the use and development of a broad spectrum of applications. But the available options lead to specific applications not compatible with the basic idea of the standard. Discussion For functional communic…

Endoscopic Ultrasonography in the Diagnosis of Regional Lymph Nodes in Esophageal and Gastric Cancer - Results of Studies in Vitro

1993

A total of 90 regional lymph nodes (43 benign/47 metastatic) from 16 surgical resection specimens of patients with esophageal and gastric carcinoma were examined in vitro by endosonography. The validity of endosonographic criteria of lymph node dignity (size, echogenicity, internal echo pattern and margin structure) was assessed using computer-supported B-mode analysis and compared to histopathological results. Of 26 lymph nodes with a diameter of more than 10 mm, 19 were metastatic (72%). The subjective assessment of the internal echo pattern (homogeneity) and the node margins by an experienced observer allowed the diagnosis of metastatic lymph nodes, but there was a high proportion of fal…

Experimentelle In-vitro-Studie zur Evaluierung eines elektronischen Detektors für die digitale Radiographie

2004

Purpose: To evaluate the contrast-detail performance of a flat-panel detector system, we performed a comparative study of this flat-panel system versus storage phosphor and conventional screen-film systems. Materials and Methods: Bone models made of human humeri were prepared with foreign bodies, fracture lines and drilled holes to create artificial fractures, osteolyses or metastases. Immersed in a water bath, hard copy images of these models were acquired with the same exposure dose (55 kV; 3.2 mAs) on the flat-panel detector, two state-of-the-art storage phosphor systems (PCR®, ADC®) and two conventional screen-film systems (Insight®, T-Mat®). Using a standardized protocol with a 4-point…

Effect of Kernels Used for the Reconstruction of MDCT Datasets on the Semi-Automated Segmentation and Volumetry of Liver Lesions

2014

Purpose: To evaluate the effect of different reconstruction kernels on the semi-automated segmentation of liver lesions in MDCT. Materials and Methods: A total 62 liver lesions were measured by three independent radiologists with the semi-automated segmentation software Oncology-Prototype (Fraunhofer MEVIS, Siemens Healthcare, Germany) using MDCT datasets (3-mm slice thickness, 2-mm increment) reconstructed with standard, soft and detailed kernels (Philips B, A and D). To ensure objective measurements, only lesions with satisfactory initial segmentation were included, and manual correction was not used. The effective diameter and volume were recorded for each lesion. Segmentation in the sof…

Attitudes Toward Artificial Intelligence Among Radiologists, IT Specialists, and Industry

2020

Objectives We investigated the attitudes of radiologists, information technology (IT) specialists, and industry representatives on artificial intelligence (AI) and its future impact on radiological work. Materials and Methods During a national meeting for AI, eHealth, and IT infrastructure in 2019, we conducted a survey to obtain participants’ attitudes. A total of 123 participants completed 28 items exploring AI usage in medicine. The Kruskal-Wallis test was used to identify differences between radiologists, IT specialists, and industry representatives. Results The strongest agreement between all respondents occurred with the following: plausibility checks are important to understand the d…

Drei-Phasen-Spiral-CT in der Diagnostik von Lebererkrankungen: Vergleich mit CT-Arteriographie und -Arterioportographie

1996

PURPOSE Assessment of the diagnostic efficacy of triphasic spiral-CT scanning (TPS-CT) for liver disease evaluation. CT arteriography (CTA) and CT arterio-portography (CTAP) were used as reference, methods which together have the highest sensitivity for detecting tumours and the perfusion conditions of the liver. MATERIAL AND METHODS 50 TPS-CT and CTA/CTPA were performed in 49 patients. After an initial examination without enhancement the first scan was initiated 15-25s after the peripheral bolus injection of contrast medium, the second after an interscan delay of 20-25s. By this means the liver was imaged in different phases of perfusion. In the course of the CTA/CTPA-exam the imaging was …

Hemangiopericytoma of the Lung - a Rare Differential Diagnosis of Lung Tumors

1988

The authors report of a 50 year old woman who was operated on because of a rectum carcinoma 5 years ago. At a follow-up examination a 2 x 2 x 1 cm sized tumor was found in the lower lobe of the right lung. Under the diagnosis of lung metastasis after rectum carcinoma resection, operation (wedge resection) was carried out. The histological examination revealed the rare tumor hemangiopericytoma. Based on this case, frequency of the tumor, clinical symptoms, surgical treatment, prognosis as well as recurrence rate and formation of metastases are discussed.

Rationelle bildgebende Diagnostik von Becken- und Azetabulum- verletzungen

2000

In spite of the widespread availability of CT scanners, conventional X-ray radiographs remain the basic imaging modality in patients with pelvic and/or acetabular trauma. However, the extent of their use will depend on local utilities (e.g., availability of CT scanners) and on the patient's clinical condition. Regarding the inaccuracy of conventional radiography in the diagnosis of injuries of the dorsal pelvic ring and of the acetabulum, computed tomography represents the most important imaging modality in the clinically stable patient. CT provides an exact staging of the extent of trauma and allows for differentiation of pelvic instabilities. CT clearly demonstrates the severity of acetab…

Teleradiologie nach Röntgenverordnung - beispielhafte Anwendung der Open-Source-Software SecTelMed

2005

Purpose: Establishing a teleradiology connection according to the Rontgenverordnung (RoV) between a peripheral hospital and a university clinic will contribute to improve the radiological emergency treatment on weekends, holidays and at night. It will also better the medical care for patients and help to lower the costs. Materials and Methods: By using the open source software SecTelMed, the radiological picture is transferred via an internet-linked SSH communication server. The integration of the teleradiological data transfer into the actual workflow is attained by using the already existing PACS infrastructure. While its installation is still under construction, it is actually employed f…

Detection of lymph node metastases in esophageal cancer.

2011

Lymph node status is the most important single prognostic factor in esophageal cancer. The detection of involved lymph nodes is therefore the key to cure. This article will provide a meta-analysis and metaregression analysis on the diagnostic performances of current lymph node-detection devices; discuss the recent status of the sentinel lymph node concept in esophageal cancer by the two sentinel node-mapping procedures (the radio-guided and the blue dye techniques) and the developing computed tomography (CT) lymphography; discuss the detection of micrometastases; and the potential clinical application of molecular-based patients' profiles. Combined use of endoscopic ultrasonography fine-nee…

Frequency and Characterization of Benign Lesions in Patients Undergoing Surgery for the Suspicion of Solid Pancreatic Neoplasm

2013

A diagnosis of benign lesions (BLs) is reported in 5% to 21% of pancreatoduodenectomies performed for neoplasms; no data for body-tail resections are available. The aims were to investigate the frequency and characterize the BLs mimicking cancer in the head and the body-tail of the pancreas.This study is a retrospective review of pancreatic specimenscollected from 2005 to 2011 in the pathology database of Mainz (Germany). Patients with final diagnosis excluding malignancy were analyzed by histology, imaging, and clinical aspects.Among 373 patients, 33 patients (8.8%) were diagnosed with a benign disease: 25 (8.4%) of 298 in the pancreatic head and 8 (10.7%) of 75 in the body-tail resections…

Structured reporting of CT scans of patients with trauma leads to faster, more detailed diagnoses: An experimental study.

2021

This study aimed to determine whether structured reports (SRs) reduce reporting time and/or increase the level of detail for trauma CT scans compared to free-text reports (FTRs).Eight radiology residents used SRs and FTRs to describe 14 whole-body CT scans of patients with polytrauma in a simulated emergency room setting. Each resident created both a brief report and a detailed report for each case using one of the two formats. We measured the time to complete the detailed reports and established a scoring system to objectively measure report completeness and the level of detail. Scoring sheets divided the CT findings into main and secondary criteria. Finally, the radiological residents com…

Gegenwärtiger Stellenwert der perkutanentranshepatischen Cholangiodrainage

2002

Percutaneous transhepatic biliary drainage (PTBD) is a well established method in the treatment of obstructive jaundice. Major indications are malignant diseases. PTBD may be necessary preoperatively in cases with severe jaundice or cholangitis or as part of palliative treatment concepts. In the past, it has been proposed that a period of preoperative PTBD may improve the morbidity rates of surgery. Various studies could not prove this theory. The significance of preoperative PTBD has changed, as observed during a 15 years period in our own institution, the indications for preoperative PTBD have decreased by half. At present, the majority of treatments with PTBD are palliative (almost 70 % …

[CT-angiography in carotid stenosis].

1997

Purpose: Prospective evaluation of the accuracy of CT angiography (CTA) with different postprocessing for extracranial carotid artery in comparison with DSA. Method: one hundred patients were studied with standarized CTA. For postprocessing, MPR, MIP, and 3D reconstruction based on segmentation with upper and lower threshold were used. Intravascular density profiles were considered. All CTA studies were correlated with intra-arterial angiography. The degree and classification of stenoses was determined using the guidelines established by the NASCET collaborators. Results: Measurement of stenosis was possible by MPR in 82.5 %, by MIP in 85 %, and 3D in 100 %. Correct classification was found…

Farbkodierte Volumen-Rekonstruktionen zur dreidimensionalen Darstellung von CT-Daten

2008

PURPOSE To evaluate a technique of colored three-dimensional reconstructions without segmentation. MATERIAL AND METHODS Color-coded volume rendered images were reconstructed from the volume data of 25 thoracic, abdominal, musculoskeletal, and vascular helical CT scans using commercial software. The CT volume rendered voxels were encoded with color in the following manner. Opacity, hue, lightness, and chroma were assigned to each of four classes defined by CT number. Color-coded reconstructions were compared to the corresponding grey-scale coded reconstructions. RESULTS Color coded volume rendering enabled realistic visualisation of pathologic findings when there was sufficient difference in…

Interdisziplin�res Polytraumamanagement

2004

Die fruhe klinische Behandlungsphase mehrfachverletzter Patienten ist durch das interdisziplinare Zusammenwirken von Unfallchirurgie, Anasthesie und Radiologie gekennzeichnet. Gemeinsames Ziel dabei ist, lebensbedrohliche Verletzungsmuster umgehend zu diagnostizieren, um adaquate therapeutische Masnahmen einleiten zu konnen. Um diese Anforderungen zu erfullen, bedarf die Radiologie ihrerseits eines standardisierten apparativen, personellen und logistischen Konzeptes zur Durchfuhrung der bildgebenden Diagnostik polytraumatisierter Patienten bei gleichbleibender Qualitat im 24-Stunden-Betrieb. Seit ihrer Einfuhrung entwickelt sich die Mehrschicht-Spiral-CT zum zentralen bildgebenden Verfahren…

Pneumonia in Febrile Neutropenic Patients and in Bone Marrow and Blood Stem-Cell Transplant Recipients: Use of High-Resolution Computed Tomography

1999

PURPOSE: To obtain statistical data on the use of high-resolution computed tomography (HRCT) for early detection of pneumonia in febrile neutropenic patients with unknown focus of infection. MATERIALS AND METHODS: One hundred eighty-eight HRCT studies were performed prospectively in 112 neutropenic patients with fever of unknown origin persisting for more than 48 hours despite empiric antibiotic treatment. Fifty-four of these studies were performed in transplant recipients. All patients had normal chest roentgenograms. If pneumonia was detected by HRCT, guided bronchoalveolar lavage was recommended. Evidence of pneumonia on chest roentgenograms during follow-up and micro-organisms detected…

Towards data-driven medical imaging using natural language processing in patients with suspected urolithiasis.

2020

Abstract Objective The majority of radiological reports are still written as free text and lack structure. Further evaluation of free-text reports is difficult to achieve without a great deal of manual effort, and is not possible in everyday clinical practice. This study aims to automatically capture clinical information and positive hit rates from narrative radiological reports of suspected urolithiasis using natural language processing (NLP). Methods Narrative reports of low dose computed tomography (CT) of the retroperitoneum from April 2016 to July 2018 (n = 1714) were analyzed using NLP. These free-text reports were automatically structured based on RadLex concepts. Manual feedback was…

Workflow-centred open-source fully automated lung volumetry in chest CT

2019

Aim To develop a robust open-source method for fully automated extraction of total lung capacity (TLC) from computed tomography (CT) images and to demonstrate its integration into the clinical workflow. Materials and methods Using only open-source software, an algorithm was developed based on a region-growing method that does not require manual interaction. Lung volumes calculated from reconstructions with different kernels (TLCCT) were assessed. To validate the algorithm calculations, the results were correlated to TLC measured by pulmonary function testing (TLCPFT) in a subgroup of patients for which this information was available within 3 days of the CT examination. Results A total of 28…

Administration of Second-Generation Extracorporeal Shock Waves without Waterbath for Fragmentation of Extra- and Intrahepatic Bile Duct Stones

1990

First-generation extracorporeal shock-wave sources disintegrate 97% of kidney stones [1, 2]. Recently, in selected patients gallbladder and common bile duct stones were also treated. The technique available so far, however, requires immersion of the patient’s body in a tank of degassed water. The procedure is therefore inconvenient, time consuming, and relatively expensive. The high pressure of shocks (up to 1000 bar) generated by underwater spark discharge causes pain, and general anesthesia is necessary in most patients [3, 4].

Segmentanatomie der Leber in der Computertomographie: Lokalisieren wir die Läsionen richtig?*

2000

Purpose: To evaluate if Couinaud's model using the planes of the major veins is an adequate tool for the presurgical localization of focal liver lesions. Methods: Biphasic helical CT scans were performed on patients evaluated for liver resection using an increased IV bolus of contrast medium (180 ml lopamidol) and 2 mm image reconstruction increments. During the first evaluation, all liver lesions were localized in the conventional way using the planes of the 3 major hepatic veins and the portal trunks as segmental boundaries. In a second review, all lesions were attributed to the nearest peripheral portal branches. The path and the segmental attribution of the portal branches were analysed…

DICOM E-mail: Germany's minimum standard for teleradiology

2005

Abstract Due to the lack of a standard for teleradiology, the IT Working Group (Arbeitsgemeinschaft fur Informationstechnik, @GIT) of the German Radiological Society (Deutsche Rontgengesellschaft, DRG) has set up an initiative for standardizing telemedicine. E-mail has been selected as the ideal basis for ad hoc connections in teleradiology since it is both easy to implement and use. The DICOM standard offers the option of appending DICOM data types as MIME attachments to any e-mail, thus enabling the transmission of the original DICOM data. Nevertheless, there are additional requirements (e.g., data privacy) that must be obeyed and implemented. The first recommendation was introduced at th…

Focal airtrapping at expiratory high-resolution CT: comparison with pulmonary function tests

2000

This study was undertaken to determine prevalence, extent, and severity of focal airtrapping at expiratory high-resolution CT, and to compare focal airtrapping with age, gender, pulmonary function tests, and blood gas analysis. Two-hundred seventeen patients with and without pulmonary disease underwent paired inspiratory/expiratory high-resolution CT. Six scan pairs with corresponding scan levels were visually assessed for focal – not diffuse – airtrapping using a four-point scale. Pulmonary function tests and blood gas analysis were available for correlation in all patients (mean interval 5 days). Focal airtrapping with lower lung predominance was observed in 80 % of patients. Twenty-six o…

CT-Angiographie der Bronchialarterien

1994

Frequency and Characterization of Benign Lesions in Pancreatic Specimens of Patients Operated for the Suspicion of Pancreatic Cancer

2012

Context A final diagnosis of benign lesions is reported in up to 21% of patients who underwent duodenocephalopancreatectomy for neoplasia, whereas no data have yet been published for resection of the body-tail. Objective To investigate the frequency and to characterize the benign lesions mimicking a neoplasia in the head and in the body-tail of the pancreas. Methods We retrospectively reviewed all the pancreatic specimens collected from 2005 to 2011 in the database of the Institute of Pathology of Mainz. Patients with a final diagnosis excluding malignancy were analyzed by histological, clinical and imaging findings. Results Three-hundreds and 73 patients were identified. A final diagnosis …

Teleradiologie mit DICOM E-mail: Empfehlungen der @GIT

2005

E-mail is ideal for ad-hoc connections in teleradiology. The DICOM standard offers the possibility to append DICOM data types as a MIME attachment to any e-mail, thus ensuring the transmission of the original DICOM data. Nevertheless, there are additional requirements (e.g. protection of data privacy) which must be obeyed. Because of the lack of given standards which would grant interoperability as well as manufacturer independence, teleradiology has not been established in Germany until today. Therefore, the IT-Team (Arbeitsgemeinschaft fur Informationstechnologie, @GIT) of the Radiological Society of Germany (Deutsche Rontgengesellschaft, DRG) set up an initiative to standardise telemedic…

Structured Reporting in Clinical Routine.

2018

 The radiology report is the key component in the communication between radiologists and referring clinicians. Traditionally, reports are written as free text. Several studies have shown that structured reporting using dedicated report templates has a number of advantages compared to conventional reports. Therefore, many radiological societies have recommended the implementation of structured reporting in clinical routine. In the meantime, collections of freely available templates have been presented and software solutions for structured reporting have been made commercially available. These allow for quality improvements in the written radiology report as they ensure that all relevant clin…

Supplemental_material - An International Survey of Quality and Safety Programs in Radiology

2020

Supplemental_material for An International Survey of Quality and Safety Programs in Radiology by Jeremy Dick, Kathryn E. Darras, Frank J. Lexa, Erika Denton, Shigeru Ehara, Howard Galloway, Bhavin Jankharia, Pam Kassing, Kanako Kunishima Kumamaru, Peter Mildenberger, Sergey Morozov, Nadya Pyatigorskaya, Bin Song, Jacob Sosna, Marcus van Buchem and Bruce B. Forster in Canadian Association of Radiologists Journal