Search

Endovascular embolization using liquid embolic agents is a safe and effective treatment option for AVMs and fistulas. Because reliable visibility of these liquid embolic agents is essential for intraprocedural visual control to prevent complications, novel angiographic systems are equipped with material-specific roadmap modes. The aim of this study was the systematic in vitro comparison of conventional and material-specific roadmap modes regarding the visibility of the most used liquid embolic agents.A recently introduced in vitro model, resembling cerebral vessels, was embolized with Onyx 18, Squid 18, PHIL 25%, andSignificant differences between conventional and material-specific roadmap modes regarding the visibility of the liquid embolic agents were observed for all study groups. All liquid embolic agents were better visible in the material-specific roadmap modes compared with the conventional mode in qualitative and quantitative analyses (eg, Onyx in conventional-versus-material-specific modes along the 1.0-mm sector: mean contrast-to-noise ratio, 5.69 [SD, 0.85] versus 47.18 [SD, 5.72];In this in vitro study, we demonstrated a better visibility of all investigated liquid embolic agents by using material-specific roadmap modes compared with the conventional roadmap technique. Especially in complex anatomic situations, these novel roadmap modes could improve the visual control and thus the safety and efficacy of embolization procedures in clinical practice.

Mit der Computertomographie (CT) konnen Thromben im linken Vorhofohr (LAA) dargestellt werden. Es wurde untersucht, ob sich die diagnostische Genauigkeit durch die Dual-Energy-Technik im Vergleich zur transosophagealen Echokardiographie (TEE) verbessert. Weiterhin wurde der Einfluss von Protokollparametern auf die Strahlendosis quantifiziert. Die TEE-Patienten wurden den verschiedenen CT-Protokollen zugeordnet. Alle CTs wurden auf das Vorhandensein von LAA-Thromben und Dual-Energy-CT-Scans sowie zusatzlich quantitativ auf die Jodkonzentration analysiert. Die TEE wurde qualitativ auf das Vorhandensein von Thromben untersucht. Von Insgesamt 32 eingeschlossenen Patienten hatten 6 einen mittels TTE diagnostizierten Thrombus. Die qualitative CT-Beurteilung ergab eine Sensitivitat von 83 % und eine Spezifitat von 88 % fur die LAA-Thrombus-Detektion. Bei 26 Patienten wurde eine Dual-Energy-CT durchgefuhrt. Die mittlere Jodkonzentration betrug 8,6 mg/cm3 und war bei Patienten mit LAA-Thromben signifikant niedriger als bei Patienten ohne LAA-Thromben. Ferner ergab sich ein inkrementeller Wert fur die Erkennung von LAA-Thromben (AUC: 0,950 vs. 0,867 bei kombinierter vs. nur qualitativer Beurteilung; p = 0,04). Die mediane Strahlendosis betrug 1,83 mSv. Unabhangig voneinander war die Dosis bei Beschrankung des Scanabschnitts auf den LAA und beim prospektiven Gating niedriger, wahrend Arrhythmie und Dual-Energy-Technik die Strahlendosis nicht beeinflussten. Die CT bietet eine gute diagnostische Genauigkeit fur den Nachweis von LAA-Thromben, die durch Joddichtemessung mittels Dual-Energy-CT noch weiter verbessert werden kann. Mit einem optimierten Protokoll kann eine angemessen niedrige Strahlendosis erreicht werden.

Background To demonstrate the efficacy of percutaneous computed tomography (CT)-guided afferent lymphatic vessel sclerotherapy (ALVS) in the treatment of postoperative lymphatic leakage (LL) after ineffective therapeutic transpedal lymphangiography (TL). Methods A retrospective review in this institute involving 201 patients was conducted from May 2011 to September 2018. Patients diagnosed with postoperative LL undergoing ineffective therapeutical TL before the performance of percutaneous CT-guided ALVS were involved. Technical success and clinical success of TL and ALVS were established. The technical success and efficacy of ALVS in the treatment of postoperative LL after ineffective therapeutic TL were assessed. The clinical success rate of ALVS is also assessed, and the complications are reviewed. Results In total, nine patients were involved including three patients (33.3%) presented with chylothorax, three patients (33.3%) presented with inguinal lymphatic fistula/lymphocele, and three patients (33.3%) presented with lymphatic fistula in the thigh; 27 ± 18 days (mean ± standard deviation) after surgery, therapeutic TL was successfully performed and showed definite afferent lymphatic vessel and leakage site in all the patients. Due to clinical failure after TLs, the following ALVS was performed with a mean interval of 12 ± 8 days after TL. The technical success rate was 9/9 (100.0%, 95% confidence interval [CI] 63.1–100.0%). An average of 2.7 ± 1.3 mL 95% ethanol as sclerosant agent was injected during the procedure. The clinical success was observed in 8 of the 9 patients (88.9%, 95% CI 51.8–99.7%) with a time between ALVS and the LL cure of 8 ± 6 days. No complications were reported. Conclusions Our results showed the role of percutaneous CT-guided ALVS as a safe, feasible, and effective salvage treatment for postoperative LL after ineffective TL.

Hintergrund Klinisch ist COVID-19 (Corona Virus Disease 2019) mit einem breiten Spektrum an Symptomen verbunden, das von milden Beschwerden eines oberen Atemwegsinfekts bis zur lebensbedrohlichen hypoxischen respiratorischen Insuffizienz und Multiorganversagen reichen kann. Fragestellung Zu den initial identifizierten pulmonalen Schädigungsmustern, wie dem diffusen Alveolarschaden bei akutem Lungenversagen, gesellen sich neue Erkenntnisse, die ein komplexeres Szenario zeichnen. Hierzu gehören Mikrogefäßbeteiligungen und ein breites Spektrum assoziierter Pathologien multipler Organsysteme. Eine Rückskalierung mikrostruktureller Gefäßveränderungen ist durch gezielte Korrelation pathologischer Obduktionsergebnisse mit radiologischer Bildgebung möglich. Material und Methoden Radiologisch-pathologische Korrelation und mikroradiologische Bildgebung zur Untersuchung der Mikrogefäßbeteiligung bei letaler COVID-19. Ergebnisse Die Fälle zweier COVID-19-Patienten werden präsentiert. Patient 1 zeigte eine relative Minderperfusion in Lungenarealen, die radiologisch keine COVID-19-typischen Infiltrate aufwiesen; die gezielte autoptische Korrelation ergab auch in diesen Lungenabschnitten bereits subtile Zeichen eines Mikrogefäßschadens. Patient 2 zeigte radiologisch und pathologisch eine fortgeschrittene COVID-19-typische Lungenstrukturdestruktion; der Fall illustriert die Schädigungsmuster der Blut-Luft-Schranke. Die CT-morphologisch perfusionsgestörte Darmwand von Patient 2 konnte letztendlich mikroskopisch nicht eindeutig auf einen intestinalen Mikrogefäßschäden zurückgeführt werden. Schlussfolgerung Die Ergebnisse weisen neben der Mikrogefäßthrombosierung auf eine funktionelle pulmonale Vasodysregulation im Rahmen der vaskulären Phase von COVID-19 hin. Hervorzuheben sind die klinische Relevanz von Obduktionen und eine enge Verzahnung von radiologischen Bildbefunden mit histopathologischen Schädigungsmustern zum besseren Verständnis von COVID-19.

Die Schwere des Verlaufs und die Sterblichkeit der Mukoviszidose (zystische Fibrose, CF) ist wesentlich durch die pulmonale Manifestation gepragt. Eine fruhe Diagnose und rasch einsetzende Therapie sind entscheidend fur einen langfristigen Erhalt der Lungenfunktion. Rontgen-Thorax und Computertomographie (CT) stehen bei der Diagnostik im Vordergrund, um den Krankheitsverlauf und das Verteilungsmuster erkennen zu konnen. Zur Vermeidung von Folgeschaden aufgrund ionisierender Strahlung durch Rontgen und CT ist das Interesse an der Magnetresonanztomographie (MRT) in der vergangenen Dekade gewachsen. Wesentliche Befunde sind Bronchialwandveranderungen, Bronchiektasen und „mucus plugging“, welche bis zu 60 % bei Kindern im Vorschulalter gefunden werden. Pleuraveranderungen und Konsolidierungen treten gehauft bei pulmonalen Exazerbationen auf. An funktionellen Veranderungen zeigen junge CF-Patienten haufig ein Mosaikmuster, und bereits ab Geburt konnen Perfusionsstorungen unterschiedlicher und im Verlauf wechselnder Schwere in 50 % der Falle (Erwachsene: bis zu 90 %) mittels kontrastmittelverstarkter Bildgebung identifiziert werden. Dilatierte Bronchialarterien zeigen ein erhohtes Risiko fur Hamoptysen an. Die Protonen-MRT ist das einzige Verfahren, welches strukturelle und funktionelle Veranderungen in einem Untersuchungsgang zeigt. Bei der Erfassung des Schweregrads aller Veranderungen hilft die strukturierte Befundung anhand eines Scoringsystems. Die MRT der Lunge bei Mukoviszidose kann heute als etabliertes Standardverfahren an erfahrenen Zentren routinemasig durchgefuhrt werden. Seit Neuestem wird sie auch im Rahmen von klinischen Studien als Endpunkt verwendet.

Die Computertomographie (CT) bietet durch ihre hohe Detailauflosung und die Moglichkeit der multidimensionalen Rekonstruktion eine zuverlassige Moglichkeit der Diagnostik und Verlaufskontrolle morphologischer Zeichen der Mukoviszidose (zystische Fibrose, CF) der Lunge. Standardisierte Leitlinien zur technischen Durchfuhrung bestehen aktuell noch nicht, werden aber fur verschiedene Altersgruppen diskutiert. Zentral bleibt die Applikation ionisierender Strahlung, die stets – jedoch auch besonders in Hinblick auf uberwiegend junge CF-Patienten – einer strengen rechtfertigenden Indikation bedarf. Der Einsatz von CT-Kontrastmitteln ist meist fur Notfallindikationen erforderlich. In der CT finden sich bereits fruhzeitig typische Lungenveranderungen der CF wie Bronchiektasien, Schleimretentionen („mucus plugging“) oder Zeichen der Uberblahung (Air Trapping). Mit der Zeit wurden verschiedene Bewertungsrichtlinien fur eine systematische Schweregradeinteilung etabliert. Diese dienen nicht nur zur individuellen Krankheitseinschatzung, sondern auch im Rahmen von Studien zur Verlaufsbeurteilung und Therapiekontrolle. Unter der technischen Entwicklung der CT kommen auch zunehmend computerbasierte Nachverarbeitungsprogramme zur halbautomatischen Auswertung und Quantifizierung zum Einsatz. Diese sollen nicht nur den klinischen Alltag erleichtern, sondern auch dazu beitragen, standardisierte und quantitative Protokolle und Auswertungen, z. B. im Rahmen von Studien, zu ermoglichen. Parallel wird nach Alternativen der Bildgebung gesucht. Zunehmende Bedeutung gewinnt die Magnetresonanztomographie (MRT), die durch verbesserte Bildqualitat sowie spezialisierte Protokolle an Bedeutung gewinnt und die CT fur Langzeitverlaufe an zahlreichen spezialisierten Zentren bereits haufig ablost.

Fokale Knorpelschaden sind haufige Pathologien der gewichtstragenden Gelenke. Die klinische Prasentation reicht von symptomlosen Patienten bis hin zu starksten, schmerzbedingten Einschrankungen der Mobilitat. Sie sind ein bedeutender Risikofaktor fur die Entwicklung degenerativer Gelenkerkrankungen. Fur die Behandlung fokaler Knorpellasionen stehen dem Orthopaden multiple chirurgische Verfahren zur Verfugung. Muskuloskeletale Radiologen sollen die Grundzuge der operativen Verfahren wie auch die typische postoperative Bildgebung kennen, um zuverlassig Abweichungen von einem normalen postoperativen Verlauf zu erkennen. Ziel dieses Ubersichtsartikels ist die Erlauterung der verschiedenen Methoden zur operativen Behandlung fokaler Knorpelschaden und deren typische MR-morphologische Darstellung. Es wurde eine PubMed-Literaturrecherche durchgefuhrt zu den Stichworten „focal articular cartilage lesions“, „chondral lesions“, „MOCART“, „Microfracture“, „Osteochondral Autograft Transfer“, „mosaicplasty“, „Osteochondral Allograft Transplantation“, „OATS“, „OCT“, „Autologous Chondrocyte Implantation“, „ACI“, „Matrix-Assisted Chondrocyte Implantation“, „Autologous Matrix-induced Chondrogenesis“. Die operativen Methoden zur Behandlung fokaler Knorpellasionen werden erklart, und die postoperative Bildgebung wird dargestellt.

The European Society of Radiology (ESR) and European Respiratory Society (ERS) published their joint statement paper on lung cancer screening (LCS), on 12 February 2020. This document joins and completes previous recommendations on LCS with specific emphasis on the analysis of issues encountered in the practical implementation of LCS in the community. Major milestones to enable the most efficient and equal dissemination of LCS are recognised as engagement of all stakeholders (e.g. candidate/participant, general practitioners, up to the specialised LCS facility), quality assurance, and primary prevention in the form of provision of counselling for smoking cessation.

BACKGROUND AND PURPOSE: The type and composition of an embolic agent have a relevant influence on the performance of endovascular embolization. The aim of this study was to investigate a new version of the liquid embolic agent precipitating hydrophobic injectable liquid (PHIL) with extra-low-viscosity in an in vivo embolization model. MATERIALS AND METHODS: Twenty-four embolization procedures were performed in the porcine rete mirabile. Eight embolizations were performed with PHIL 25% low viscosity, Squid 12, and standard PHIL 25%, respectively. Procedure time, required volume of embolic agent, visibility of the embolic agent, embolization control, embolization extent (ie, penetration of the rete mirabile), amount of reflux, and degree of embolization distal to the rete mirabile were assessed. RESULTS: All embolic agents were adequately visible. The embolization extent was not significantly different among the 3 investigated agents; however, there was a tendency toward a higher embolization extent for PHIL 25% low viscosity (median embolization extent: 88% [PHIL 25% low viscosity]; 65% [Squid 12]; 60% [PHIL 25%]; P = .146). The amount of reflux was significantly lower for the extra-low-viscosity agents PHIL 25% low viscosity and Squid 12 compared with the standard PHIL 25% (median reflux distance: 8 mm [PHIL 25% low viscosity]; 6 mm [Squid 12]; 17 mm [PHIL 25%]; P = .011). All other embolization features did not differ among agents. CONCLUSIONS: PHIL 25% low viscosity is a promising liquid embolic agent for endovascular embolization, featuring effective distal penetration, adequate visibility, a low amount of reflux, and good flow control.

To investigate radiopacity, size and size calibration, morphology, and vascular distribution of inherently radiopaque microspheres in vitro and in a pig embolization model. We compared three types of microspheres: DCBead™ (size 100–300 µm) and Embozene™ (250 µm) as clinically established microspheres, and the prototype Visible (250 µm) that contains additional radiopaque material. Size and size calibration of microspheres were examined by laser diffraction. Pulmonary artery embolization was performed in 12 pigs, and radiopacity was examined by in vitro micro-computed tomography (CT), in vivo cone-beam CT, and ex vivo micro-CT after killing. Morphology and vascular distribution of microspheres were microscopically examined. In in vitro and ex vivo micro-CT, radiopacity of Visible was higher than that of Embozene™, whereas DCBead™ showed no radiopacity. In in vivo cone-beam CT, radiopacity was observed with Visible but not with Embozene™ and DCBead™. Laser diffraction revealed that 7.0% (Visible), 6.5% (Embozene™), and 22.5% (DCBead™) of microspheres were smaller than 223.5 μm. Visible and Embozene™ microspheres were very often located in bronchiolus-associated arteries, but rarely in subsegmental and capillary arteries, whereas DCBead™ were very often and often detected in bronchiolus-associated arteries and capillary arteries, respectively (and rarely in subsegmental arteries). After pulmonary artery embolization, Visible but not Embozene™ or DCBead™ provide in vivo radiopacity in cone-beam CT. In contrast to non-narrow-size-calibrated DCBead™, pulmonary artery embolization with narrow-size-calibrated Visible and Embozene™ result in a predictable arterial distribution without embolization-related hemorrhagic lung infarction.

In dieser Studie wurden Methoden der Tumorlastquantifizierung in der Ganzkorper-Magnetresonanztomographie (GK-MRT) beim Multiplen Myelom untersucht und mit krankheitstypischen Parametern in Serum und Knochenmark korreliert. Die GK-MRT von 52 Patienten mit fokalem Befallsmuster wurden retrospektiv ausgewertet. 700 fokale Lasionen (im Folgenden Lasionen genannt) wurden in kugelig und nicht-kugelig eingeteilt, manuell segmentiert und der langste Durchmesser (LD) bestimmt. Gesamtanzahl und -volumen der Lasionen wurden mit klinischen Parametern und Prognose sowie der LD mit dem segmentierten Volumen (SV) der Lasionen korreliert. SV und per Kugelformel anhand dem LD berechnetes Volumen (BV) wurden auf Ubereinstimmung analysiert. Es zeigten sich keine signifikanten Korrelationen von Gesamtanzahl/-volumen der Lasionen mit den uberwiegend normwertigen Parametern oder der Prognose. 10 % der Lasionen waren kugelig. SV und LD korrelierten signifikant fur die einzelnen Lasionen und auf Patientenebene. Das SV war bei Lasionen

Aim To define practical limitations of diagnostic image quality for recently introduced turbo high-pitch scan mode (THP) in third-generation dual-source computed tomography (CT). Materials and Methods Two hundred and twenty-nine consecutive patients undergoing CT coronary angiography were included in this retrospective single-centre analysis. A contrast-enhanced volume dataset was acquired in THP. Image quality of coronary segments was classified as diagnostic or non-diagnostic by three blinded readers. Segments were stated as non-diagnostic if at least one of three readers could neither exclude nor confirm significant stenoses. Multivariable logistic regression was used to assess relationships between number of non-diagnostic segments and common influencing factors. Results Median effective radiation dose was 0.6 (interquartile range [IQR], 0.4–0.8) mSv overall and 0.3 (IQR, 0.3–0.4) mSv in the 70 kV subgroup of this middle aged, predominantly pre-obese cohort (age: 61 [IQR, 52–67] years; body mass index [BMI]: 26 [IQR, 23–29] kg/m2) with a low–moderate median Agatston score (AS) 0 (IQR, 0–70). Diagnostic image quality was found in 98.1% of 3,678 coronary segments. AS was independently associated with diagnostic image quality (B=0.34; p=0.02), whereas heart rate, BMI, and presence of arrhythmia were not. The portion of diagnostic coronary segments decreased slightly in obese patients with heart rates >65 beats/min and dropped significantly in patients with an AS >600 (p=0.003). Conclusion THP enables CT coronary angiography with minimal radiation exposure and is most appropriate in non-obese patients with stable sinus rhythm ≤65 beats/min and a calcium score ≤600.

Purpose This study aimed to evaluate contrast-enhanced computed tomography (CE-CT) features for prediction of arterial tumor invasion in pancreatic cancer (PDAC) patients in the event of arterial encasement >180° after neoadjuvant (radio-)chemotherapy (NAT). Methods Seventy PDAC patients with seventy-five arteries showing encasement >180° after completion of NAT were analyzed. All patients underwent surgical exploration with either tumor resection including arterial resection, periadventitial dissection (arterial divestment) or confirmation of locally irresectable disease. CE-CT scans were assessed regarding tumor extent and artery-specific imaging features. The results were analyzed on a per-artery basis. Based on the intraoperative and histopathological findings, encased arteries were classified as either invaded or non-invaded. Results Eighteen radiologically encased arteries were resected; of these, nine had pathologic evidence for tumor invasion. In 42 encased arteries, the tumor could be removed by arterial divestment. In 13 patients with 15 encased arteries, the tumor was deemed technically irresectable. Median tumor size, length of solid soft tissue contact, and degree of circumferential contiguity by solid soft tissue along the artery in CE-CT were significantly lower in the non-invaded than in the invaded artery group (p ≤ 0.017). Imaging features showed moderate accuracies for prediction of arterial invasion (≤72.0 %). The thresholds ≤26 mm for post-NAT solid soft tissue contact and ≤270° for circumferential contiguity by solid soft tissue had high negative predictive values (≥87.5 %). Conclusion Although post-NAT prediction of arterial invasion remains difficult, arteries with ≤270° contiguity by soft tissue and arteries with ≤26 mm length of solid soft tissue contact are unlikely to be invaded, with possible implications for surgical planning.

Bei der Behandlung des lokalisierten Nierenzellkarzinoms stellt das fehlende Randomisieren in den kontrollierten Studien zur Thermoablation eine wesentliche Limitation dar. Letztgenanntes fuhrt zu wesentlichen Studienverzerrungen und es bleibt letztendlich unklar, ob das verbesserte Gesamtuberleben zugunsten der partiellen Nephrektomie tatsachlich auf die Behandlungsmethode selbst zuruckzufuhren ist. Fur T1a (≤4 cm)-Nierenzellkarzinome ohne Lymphknoten- und Fernmetastasen sind exzellente technische und klinische Ergebnisse nach bildgefuhrter Radiofrequenz- und Kryoablation beschrieben. Niedrige Majorkomplikationsraten, die Erhaltung der Nierenfunktion sowie die dreidimensionale Bestatigung negativer Ablationsrander (A0-Ablation) sind die Vorteile der CT-gesteuerten Thermoablation. Entsprechend kontrollierten (nichtrandomisierten) klinischer Studien zum T1a Nierenzellkarzinom sind die krebsspezifischen Uberlebensraten zwischen ablativen und chirurgischen Techniken vergleichbar. Es ist hochste Zeit fur prospektive randomisierte kontrollierte Studien, um den tatsachlichen Stellenwert der perkutanen Thermoablation und der partiellen Nephrektomie bei der Behandlung des T1a-Nierenzellkarzinoms zu bestimmen. Neben dem lokalisierten Nierenzellkarzinom eignen sich Angiomyolipome und Onkozytome fur die Thermoablation. Die transarterielle Embolisation erweitert das radiologische Spektrum bei der Behandlung von Nierentumoren, entweder als erganzende Embolisation (z. B. vor Thermoablation von T1a- und T1b-Nierenzellkarzinomen), als prophylaktische Embolisation (z. B. Angiomyolipome >6 cm), als praoperative Embolisation (z. B. vor laparoskopischer partieller Nephrektomie) oder als palliative Embolisation (z. B. bei inoperablen Patienten mit symptomatischer Makrohamaturie bei Nierenzellkarzinom).

Pulmonale Komplikationen sind bei Patienten mit Kollagenosen keine Seltenheit. Haufig sind eine direkte Manifestation der Grunderkrankung, eine Nebenwirkung der medikamentosen Therapie oder eine Lungeninfektion die Ursachen. Das radiologische Standardverfahren zur Klarung pulmonaler Pathologien bei Patienten mit Kollagenosen ist die Multidetektorcomputertomographie mit dunnschichtigen Rekonstruktionen (Dunnschicht-MDCT). Die Treffsicherheit der Dunnschicht-MDCT ist fur die Identifikation eines Erkrankungsmusters sehr hoch. So kann beispielsweise das Muster einer gewohnlichen interstitiellen Pneumonie (UIP) als direkte Lungenmanifestation einer rheumatoiden Arthritis mit einer Sensitivitat von 45 % und einer Spezifitat von 96 % identifiziert werden. Sowohl die direkte Lungenmanifestation als auch die Medikamententoxizitat sowie manche Infektionen konnen bei verschiedenen Kollagenosen auf der Dunnschicht-MDCT ein ahnliches Bild abgeben. Die Kenntnis von Mustern und Ursachen tragt zur diagnostischen Sicherheit bei. Bei Erstdiagnose einer Erkrankung aus dem rheumatischen Formenkreis und pulmonalen Symptomen empfiehlt sich eine Dunnschicht-MDCT. Zusatzlich wird je nach CT-Befund alle 6 bis 12 Monate eine klinische, lungenfunktionelle und bildgebende Verlaufskontrolle empfohlen. In jedem Fall mussen die einzelnen CT-morphologischen Muster der Lungenbeteiligung identifiziert werden. Die Kombination von Informationen zur Anamnese, zu klinischen Befunden und Bildgebung ist Voraussetzung fur ein adaquates Krankheitsmanagement.

Granulome als Zeichen der spezifischen Entzundung im Lungengewebe treten bei zahlreichen Erkrankungen mit pulmonaler Manifestation auf und stellen einen wichtigen Befund in der Bildgebung dar. Das radiologische Standardverfahren bei pulmonalen Granulomatosen ist meistens die Dunnschichtcomputertomographie, in wenigen Fallen, wie z. B. bei Tuberkulose, Sarkoidose und Silikose, spielt die Rontgenthoraxubersicht immer noch eine wichtige Rolle. Bei der Standardabklarung der meisten Granulomatosen ist die Hinzunahme weiterer Verfahren nicht notwendig. Bei speziellen Fragestellungen spielen MRT und Positronenemissionstomographie (PET) eine Rolle, z. B. die Kardio-MRT bei Verdacht auf kardiale Beteiligung bei Sarkoidose oder die Cholin-PET-CT bei V. a. ein Narbenkarzinom bei Tuberkulose. Die Sensitivitat der Dunnschicht-CT ist bei den Granulomatosen sehr hoch. Insbesondere bei chronifizierten Verlaufen mit Ausbildung fibrotischer Veranderungen bzw. einer interstitiellen Lungenerkrankung ist eine Dunnschicht-CT zur Differenzierung des Erkrankungsmusters wichtig. Ebenso spielt die Dunnschicht-CT eine wichtige Rolle bei der Diagnostik von Komplikationen und Begleiterkrankungen, z. B. Malignomen. Die Methode gehort inzwischen zur alltaglichen klinischen Praxis. Bei klinischem Verdacht auf eine pulmonale Granulomatose und entsprechenden Hinweisen in der Thoraxubersicht sind eine Dunnschicht-CT und die interdisziplinare Diskussion der Befunde zu empfehlen.

Klinisches/methodisches Problem Bestrebungen zur Fruherkennung von Lungenkrebs mit bildgebenden Methoden gibt es schon lange.

Klinisches/methodisches Problem Die vorliegende Ubersichtsarbeit soll uber den gegenwartigen Stellenwert der sog. subintimalen Rekanalisation in der unteren Extremitat informieren.

On February 26th, 2013 the patient law became effective in Germany. Goal of the lawmakers was a most authoritative case law for liability of malpractice and to improve enforcement of the rights of the patients. The following article contains several examples detailing legal situation. By no means should these discourage those persons who treat patients. Rather should they be sensitized to to various aspects of this increasingly important field of law. To identify relevant sources according to judicial standard research was conducted including first- and second selection. Goal was the identification of jurisdiction, literature and other various analyses that all deal with liability of malpractice and patient law within the field of Interventional Radiology – with particular focus on transarterial chemoembolization of the liver and related procedures. In summary, 89 different sources were included and analyzed. The individual who treats a patient is liable for an error in treatment if it causes injury to life, the body or the patient’s health. Independent of the error in treatment the individual providing medical care is liable for mistakes made in the context of obtaining informed consent. Prerequisite is the presence of an error made when obtaining informed consent and its causality for the patient’s consent for the treatment. Without an effective consent the treatment is considered illegal whether it was free of treatment error or not. The new patient law does not cause material change of the German liablity of malpractice law. Key points: • On February 26th, 2013 the new patient law came into effect. Materially, there was no fundamental remodeling of the German liability for medical malpractice. • Regarding a physician‘s liability for medical malpractice two different elements of an offence come into consideration: for one the liability for malpractice and, in turn, liability for errors made during medical consultation in the process of obtaining informed consent. • Forensic practice shows that patients frequently enforce both offences concurrently. Citation Format: • Sommer SA, Geissler R, Stampfl U et al. Medical Liability and Patient Law in Germany: Main Features with Particular Focus on Treatments in the Field of Interventional Radiology. Fortschr Rontgenstr 2016; 188: 353 – 358

Purpose To survey integrative teaching in radiology at German universities. Materials and methods A questionnaire about radiological education was sent electronically to all 37 chairpersons of university radiology departments in Germany. The questions included the course type, teaching methods, concept, perception, and advantages and disadvantages of integrative teaching. Statistical analysis was performed with nonparametric statistics and chi-square test. Results The survey was considered representative with a return rate of 68 %. Integrative teaching is established at 4/5 of all departments. Integrative teaching is well accepted with an acceptance rate that is significantly higher in so-called "Modellstudiengangen" [model courses of study] (100 %) compared to conventional courses of study (72 %). The advantages of integrative teaching include linking of content (92 %) and preparation for interdisciplinary work (76 %). The disadvantages include high effort (75 %) and time (67 %) for organization. Furthermore, there is a risk that basic radiological facts and knowledge cannot be conveyed and that the visibility of radiology as an independent discipline is lost. Conventional radiological teaching has a similarly high acceptance (84 %) compared to integrative courses (76 %). Conclusion Integrative teaching has a high acceptance among chairpersons in radiology in Germany despite the greater effort. A good interdisciplinary collaboration is essential for integrative teaching and at the same time this can be conveyed to the students. However, the visibility of radiology as a discipline and the possibility to cover basic radiological content must be ensured. Therefore, both conventional courses and integrative teaching seems reasonable, especially in cross-disciplinary subjects such as radiology. Key points Both integrative teaching and conventional radiological teaching are highly accepted. The advantages include the linking of multidisciplinary content and the preparation for interdisciplinary cooperation. The disadvantages include more time and effort for organization and reduced visibility of cross-disciplinary subjects.

Trotz eines im Durchschnitt erhohten kardiovaskularen Risikos sind Diabetiker eine heterogene Population mit hochst unterschiedlichen individuellen Krankheitsverlaufen, sodass eine fundierte Risikostratifizierung von Noten ist. Die klinische Untersuchung und die Bestimmung von Blutwerten dienen bei Diabetikern typischerweise zur Risikostratifizierung bzgl. kardio(zerebro)vaskularer Ereignisse in der Zukunft. Sowohl die Kardio- als auch die Ganzkorper-MRT stellen standardisierte Verfahren in der klinischen Diagnostik dar. Deren Stellenwert bei der Vorhersage von Ereignissen mit entsprechender Risikostratifizierung bei Diabetikern gewinnt basierend auf aktuellen Studienergebnissen zunehmend an Bedeutung. Late Gadolinium Enhancement (LGE) im Kardio-MRT detektiert bei bis zu 30 % der Diabetiker stumme Myokardischamien, die mit einer Hazard Ratio von 3–6 mit kardiovaskularen Ereignissen assoziiert sind. Ebenfalls zeigen linksventrikulare Wandbewegungsstorungen sowie eine erniedrigte Ejektionsfraktion einen prognostischen Wert. Im Ganzkorper-MRT sind der Vessel-Score und Karotisstenosen zusatzliche Pradiktoren fur kardio(zerebro)vaskulare Ereignisse. Die MRT-basierte Vorhersage kardio(zerebro)vaskularer Ereignisse bietet einen signifikanten Mehrwert zur klassischen Risikostratifizierung bei Diabetikern. Jedoch erlaubt nur die umfassende Ganzkorper-MRT-Untersuchung Patienten zu identifizieren, die uber einen Zeitraum von 6 Jahren komplett frei von kardio(zerebro)vaskularen Ereignissen bleiben. Die Kardio-MRT, insbesondere die Erfassung von LGE, empfiehlt sich fur die Vorhersage von Ereignissen. Die Ganzkorper-MRT stellt einen prognostischen Mehrwert dar, deren klinische Relevanz in weiteren Studien geklart werden muss.

Bei den antineoplastischen Chemotherapien werden klassische Zytostatika zunehmend durch Antikorper und sog. zielgerichtete Therapien erganzt. Neben der antineoplastischen Wirkung und allgemeinen Unvertraglichkeiten finden sich haufig recht charakteristische Veranderungen, die der Radiologe kennen sollte. Hier ist die Abgrenzung des dargestellten Befunds zwischen Nebenwirkung und Tumorprogress bzw. infektioser Genese essenziell. Klassische antineoplastische Chemotherapien interagieren mit Desoxyribonukleinsaure(DNA)- und (Ribonukleinsaure)RNA-Synthese, DNA-Reparatur oder dem Mitoseapparat. Moderne zielgerichtete antineoplastische Therapien wirken auf der Ebene von Signaltransduktionspfaden. Lokalisierte, organbezogene Veranderungen folgen metabolischen Eigenschaften der Organe oder anatomischen Eigenheiten wie der Beschaffenheit der lokalen Blut-Gewebe-Schranke. Toxizitatsassoziierte Befunde ahneln haufig fulminantem Tumorprogress. Neue zielgerichtete antineoplastische Therapien weisen Toxizitaten mit nichtkumulativem Charakter auf. Deshalb sind morphologische Veranderungen haufig Vorlaufer der klinischen Toxizitat. Die onkologische Radiologie erfordert zunehmend den aktiven, interdisziplinaren Dialog, um morphologische Korrelate der Organtoxizitat in der Differenzialdiagnose richtig zu deuten, gegen Tumorprogress abzugrenzen und richtige therapeutische Masnahmen einzuleiten.

Percutaneous radiofrequency ablation (RFA) for the treatment of stage I renal cell carcinoma has recently gained significant attention as the now available long-term and controlled data demonstrate that RFA can result in disease-free and cancer-specific survival comparable with partial and/or radical nephrectomy. In the non-controlled single center trials, however, the rates of treatment failure vary. Operator experience and ablation technique may explain some of the different outcomes. In the controlled trials, a major limitation is the lack of adequate randomization. In case reports, original series and overview articles, transarterial embolization (TAE) before percutaneous RFA was promising to increase tumor control and to reduce complications. The purpose of this study was to systematically review the literature on TAE as add-on to percutaneous RFA for renal tumors. Specific data regarding technique, tumor and patient characteristics as well as technical, clinical and oncologic outcomes have been analyzed. Additionally, an overview of state-of-the-art embolization materials and the radiological perspective of advanced image guided tumor ablation (TA) will be discussed. In conclusion, TAE as add-on to percutaneous RFA is feasible and very effective and safe for the treatment of Tl a tumors in difficult locations and Tl b tumors. Advanced radiological techniques and technologies such as microwave ablation, innovative embolization materials and software-based solutions are now available, or will be available in the near future, to reduce the limitations of bland RFA. Clinical implementation is extremely important for performing image-guided TA as a highly standardized effective procedure even in the most challenging cases of localized renal tumors.

To evaluate the current guidelines as a model to predict malignancy and to determine further radiological predictors of malignancy in intraductal papillary mucinous neoplasms (IPMNs).384 patients who had undergone a pancreatic operation with the pathological diagnosis of IPMN as well as applicable pre-operative imaging (CT/MRI) were included in the study. Images were evaluated retrospectively in consensus by two radiologists, using a standardized checklist. Descriptive statistics, binary logistic regression and receiver operator curve analysis were performed to assess the International Consensus Guidelines and other radiological predictors of clinical malignancy (defined as carcinoma in situ and invasive carcinoma).The best independent predictors of malignancy (n = 191) were solid components [odds ratio (OR) 3.98], parenchymal atrophy with main pancreatic duct dilation 5-9 mm (OR: 5.1) and common bile duct (CBD) dilation (OR: 31.26).96% of all cases with CBD dilation were malignant IPMNs (positive-predictive value 96.4%; negative-predictive value 63.1%). Analysis of the current guidelines showed a diagnostic improvement with the addition of CBD dilation on determining the malignancy of IPMNs (sensitivity 82.2%/86.9%; specificity 72.7%/74.6%). Subanalysis of branch duct intraductal papillary mucinous neoplasms (BD-IPMNs; n = 168) also resulted in a diagnostic improvement with the addition of CBD dilation (sensitivity 28.6%/45.2%; specificity 92.9%/92.1%). The best independent predictors of malignancy for BD-IPMNs were parenchymal atrophy (OR: 4.00) and CBD dilation (OR: 29.3). Frequency analysis revealed that even small BD-IPMNs had already undergone malignant transformation (≤1 cm: 15%; 1-2 cm: 26%; 2-3 cm: 20%) with about 10% of those having a dilated bile duct.CBD dilation was a significant positive predictor of malignancy in IPMNs regardless of their size.Introduction of CBD dilation as a radiological predictor for malignancy might increase the diagnostic accuracy of current imaging-based guidelines.

Hepatic alveolar echinococcosis (AE) resembles intrahepatic cholangiocarcinoma (ICC) on radiological imaging. The purpose of this study was to identify criteria to discriminate AE from ICC with CT and MR Imaging.One hundred and sixteen imaging studies of 94 patients (CT n = 65; MRI n = 51) diagnosed with AE (n = 55) or ICC (n = 39) were retrospectively reviewed by two blinded radiologists for lesion features including enhancement pattern and matrix composition. A consensus read was conducted in cases of disagreement. Uni- and multivariate logistic regression with bootstrapping were used for analysis.Using CT, no or septal enhancement and calcification yielded the highest values of sensitivity/specificity (90.9%/90.6% and 81.8%/96.9%) for AE. Using MRI, no or septal enhancement and cystic components achieved the highest sensitivity/specificity (90.9%/100.0% and 84.8%/66.7%) for AE. Multivariate logistic regression identified the following strong independent predictors for AE: for MRI, no or septal enhancement (odds ratio [OR] 322.4; p0.001); for CT, no or septal enhancement and calcification (OR 35.9 and 42.5; p0.001 and p0.01, respectively). No or septal enhancement and calcification demonstrated the highest interreader agreement (90%).Enhancement characteristics and matrix calcifications offer the strongest discriminating potential between AE and ICC with a high sensitivity, specificity, and interreader agreement.

To prospectively evaluate whether intravenous morphine co-medication improves bile duct visualization of dual-energy CT-cholangiography.Forty potential donors for living-related liver transplantation underwent CT-cholangiography with infusion of a hepatobiliary contrast agent over 40 min. Twenty minutes after the beginning of the contrast agent infusion, either normal saline (n=20 patients; control group [CG]) or morphine sulfate (n=20 patients; morphine group [MG]) was injected. Forty-five minutes after initiation of the contrast agent, a dual-energy CT acquisition of the liver was performed. Applying dual-energy post-processing, pure iodine images were generated. Primary study goals were determination of bile duct diameters and visualization scores (on a scale of 0 to 3: 0--not visualized; 3--excellent visualization).Bile duct visualization scores for second-order and third-order branch ducts were significantly higher in the MG compared to the CG (2.9±0.1 versus 2.6±0.2 [P0.001] and 2.7±0.3 versus 2.1±0.6 [P0.01], respectively). Bile duct diameters for the common duct and main ducts were significantly higher in the MG compared to the CG (5.9±1.3 mm versus 4.9±1.3 mm [P0.05] and 3.7±1.3 mm versus 2.6±0.5 mm [P0.01], respectively).Intravenous morphine co-medication significantly improved biliary visualization on dual-energy CT-cholangiography in potential donors for living-related liver transplantation.

Quantitative image quality assessment in terms of image noise (IN), contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) in relation to required radiation dose (RD) for dual-energy (DE), standard and low-kVp contrast-enhanced computed-tomography (CT) cholangiography.For each of 22 DECT-cholangiography examinations, 3 image datasets were analyzed as independent single-source CT-acquisitions at different tube potential, i.e. 80 kVp, 120 kVp-equivalent (linear blended dataset M0.3: 30% 80 kVp, 70% 140 kVp), and 140 kVp. Analysis comprised determination of IN, CNR and SNR in regions of interest (ROI) placed in liver parenchyma and contrasted bile ducts. IN was evaluated as mean standard deviation of 3 ROI placed within liver parenchyma (segments 6/7, 5/8, 2/3); CNR was assessed as bile duct-to-liver parenchyma ratio, and SNR as bile duct-to-image noise ratio. RD in terms of CT dose index (CTDI(vol)), dose-length product (DLP) and effective dose (ED) has been determined for each of the datasets, and compared to console prediction and scan summary values. Using phantom measurements of CTDI(vol), a method for separating comprehensive RD values of DE-acquisitions into the original RD contribution of each tube (80 kVp/140 kVp) has been developed, enabling comparison of all 3 datasets as if independently acquired using single-source "single-energy" technique.Highest IN was detected for 80 kVp- (38.6 ± 5.1HU), lowest for 120 kVp-equivalent linear blended M0.3-datasets (23.1 ± 3.4HU) with significant differences between all datasets (P0.001). Highest SNR and CNR were measured for M0.3- (SNR: 14.8 ± 4.1; CNR: 11.6 ± 3.8) and 80 kVp-datasets (SNR: 13.8 ± 4.8; CNR: 11.2 ± 4.5); lowest for 140 kVp-datasets (SNR: 9.5 ± 2.5; CNR: 7.1 ± 2.3) with significant differences between M0.3- and 140 kVp-datasets as well as between 80 kVp- and 140 kVp-datasets (both P0.001 for both CNR, SNR). CTDI(vol), DLP and ED were reduced by 50% for low-kilovoltage acquisitions (CTDI(vol): 5.5 ± 1.4 mGy; DLP: 127.8 ± 40.1 mGy cm; ED: 1.9 ± 0.6 mSv) compared to comprehensive DE-acquisitions (CTDI(vol): 11.0 ± 2.3 mGy; DLP: 253.8 ± 67.5 mGy cm; ED: 3.8 ± 1.0 mSv, tube contribution: 80 kVp: 44.5%; 140 kVp: 55.5%), and by 20% compared to conventional acquisitions at 120 kVp (CTDI(vol): 6.71 mGy; DLP: 153.5 ± 16.9 mGy cm; ED: 2.3 ± 0.3 mSv).Despite higher IN, low-kilovoltage CT-cholangiography reveals no significant difference with respect to CNR and SNR when compared to linear blended images yielded by DECT. Compared to DECT or conventional CT at 120 kVp, contrast-enhanced low-kVp CT cholangiography potentially allows reduction of patient dose by up to 50% or 20%, respectively. Therefore, CT-cholangiography at 80 kVp should be considered as an alternative to DECT-cholangiography whenever DECT is unavailable, or if increased image quality of DECT regarding quantitative bile duct evaluation is not needed for diagnosis.

The new German S3 guideline regarding stomach cancer includes a variety of innovations with respect to the diagnosis and treatment of adenocarcinoma of the stomach and the esophagogastric junction. The guideline has been strongly supported by the "oncology" guidelines program consisting of the "Deutsche Krebshilfe" and the German Cancer Society and the AWMF (Dr. M. Follmann). This guideline contains evidence-based treatment recommendations and quality indicators for guideline implementation and evaluation in order to improve broad medical care and to facilitate development and subsequent adjustment. The purpose of this article is to introduce the innovations with regard to radiological diagnosis and to discuss the latest literature on the subject.

Das hepatozellulare Karzinom (HCC) ist weltweit betrachtet das funfthaufigste Malignom und die Haupttodesursache bei Patienten mit Leberzirrhose in Europa. Wahrend kurative Therapieansatze (Resektion, Lebertransplantation sowie perkutane Ablation) bei nur 30–40% der Patienten mit einem HCC moglich sind, erfordern die meisten Patienten lokoregionare bzw. palliative Therapieansatze.

Aim To report our experience of combined CT- and fluoroscopy-guided nephrostomy in patients with non-obstructive uropathy due to urine leaks in cases of failed ultrasound-guided procedures. Patients and methods Eighteen patients (23 kidneys) with non-obstructive uropathy due to urine leaks underwent combined CT- and fluoroscopy-guided nephrostomy. All procedures were indicated as second-line interventions after failed ultrasound-guided nephrostomy. Thirteen males and five females with an age of 62.3±8.7 (40–84) years were treated. Urine leaks developed in majority after open surgery, e.g. postoperative insufficiency of ureteroneocystostomy (5 kidneys). The main reasons for failed ultrasound-guided nephrostomy included anatomic obstacles in the puncture tract (7 kidneys), and inability to identify pelvic structures (7 kidneys). CT-guided guidewire placement into the collecting system was followed by fluoroscopy-guided nephrostomy tube positioning. Procedural success rate, major and minor complication rates, CT-views and needle passes, duration of the procedure and radiation dose were analyzed. Results Procedural success was 91%. Major and minor complication rates were 9% (one septic shock and one perirenal abscess) and 9% (one perirenal haematoma and one urinoma), respectively. 30-day mortality rate was 6%. Number of CT-views and needle passes were 9.3±6.1 and 3.6±2.6, respectively. Duration of the complete procedure was 87±32min. Dose-length product and dose-area product were 1.8±1.4Gycm and 3.9±4.3Gycm 2 , respectively. Conclusions Combined CT- and fluoroscopy-guided nephrostomy in patients with non-obstructive uropathy due to urine leaks in cases of failed ultrasound-guided procedures was feasible with high technical success and a tolerable complication rate.

This study was designed to investigate the benefit of percutaneous interventional management of patients with postoperative bile leak on clinical outcome. Primary study endpoints were closure of the bile leak and duration of percutaneous transhepatic biliary drainage (PTBD) treatment. Secondary study endpoints were necessity of additional CT-guided drainage catheter placement, course of serum CRP level as parameter for inflammation, and patients' survival.Between January 2004 and April 2008, all patients who underwent PTBD placement after upper gastrointestinal surgery were analyzed regarding site of bile leak and previous attempt of operative bile leak repair, interval between initial surgery and PTBD placement, procedural interventional management, course of inflammation parameters, duration of PTBD therapy, PTBD-related complications, and patients' survival.Thirty patients underwent PTBD placement for treatment of postoperative bile leaks. In 12 patients (40%), PTBD was performed secondary to a surgical attempt of bile leak repair. Additional percutaneous drainage of bilomas was performed in 14 patients (47%). CRP serum level decreased from 138.1 ± 73.4 mg/l before PTBD placement to 43.5 ± 33.4 mg/l 30 days after PTBD placement. The mean duration of PTBD treatment was 55.2 ± 32.5 days in the surviving patients. In one patient, a delayed stenosis of the bile duct required balloon dilation. Two PTBD-related complications (portobiliary fistula, hepatic artery aneurysm) occurred, which were successfully treated by embolization. Overall survival was 73% (22 patients).PTBD treatment is an effective therapy. PTBD treatment and additional CT-guided drainage of bilomas helped to reduce intraabdominal inflammation, as shown by reduction of inflammation parameters.

The purpose of this study was to evaluate the technical and clinical success of superselective embolization in patients with life-threatening arterial renal hemorrhage undergoing preinterventional CT angiography. Forty-three patients with clinical signs of life-threatening arterial renal hemorrhage underwent CT angiography and catheter angiography. Superselective embolization was indicated in the case of a positive catheter angiography. Primary study goals were technical and clinical success of superselective embolization. Secondary study goals were CT angiographic and catheter angiographic image findings and clinical follow-up. The mean time interval between CT angiography and catheter angiography was 8.3 ± 10.3 h (range, 0.2–34.1 h). Arterial renal hemorrhage was identified with CT angiography in 42 of 43 patients (98%) and catheter angiography in 39 of 43 patients (91%) (overview angiography in 4 of 43 patients [9%], selective angiography in 16 of 43 patients [37%], and superselective angiography in 39 of 43 patients [91%]). Superselective embolization was performed in 39 of 43 patients (91%) and technically successful in 37 of 39 patients (95%). Therefore, coil embolization was performed in 13 of 37 patients (35%), liquid embolization in 9 of 37 patients (24%), particulate embolization in 1 of 37 patients (3%), and a combination in 14 of 37 patients (38%). Clinical failure occurred in 8 of 39 patients (21%) and procedure-related complications in 2 of 39 patients (5%). The 30-day mortality rate was 3%. Hemoglobin decreased significantly prior to intervention (P < 0.001) and increased significantly after intervention (P < 0.005). In conclusion, superselective embolization is effective, reliable, and safe in patients with life-threatening arterial renal hemorrhage. In contrast to overview and selective angiography, only superselective angiography allows reliable detection of arterial renal hemorrhage. Preinterventional CT angiography is excellent for detection and localization of arterial renal hemorrhage and appropriate for guidance of the embolization procedure.

The purpose of this study was to evaluate the impact of stent design on in-stent stenosis in rabbit iliac arteries. Four different types of stent were implanted in rabbit iliac arteries, being different in stent design (crown or wave) and strut thickness (50 or 100 microm). Ten stents of each type were implanted. Each animal received one crown and one wave stent with the same strut thickness. Follow-up was either 12 weeks (n = 10 rabbits) or 24 weeks (n = 10 rabbits). Primary study end points were angiographic and microscopic in-stent stenosis. Secondary study end points were vessel injury, vascular inflammation, and stent endothelialization. Average stent diameter, relative stent overdilation, average and minimal luminal diameter, and relative average and maximum luminal loss were not significantly different. However, a trend to higher relative stent overdilation was recognized in crown stents compared to wave stents. A trend toward higher average and minimal luminal diameter and lower relative average and maximum luminal loss was recognized in crown stents compared to wave stents with a strut thickness of 100 microm. Neointimal height, relative luminal area stenosis, injury score, inflammation score, and endothelialization score were not significantly different. However, a trend toward higher neointimal height was recognized in crown stents compared to wave stents with a strut thickness of 50 microm and a follow-up of 24 weeks. In conclusion, in this study, crown stents seem to trigger neointima. However, the optimized radial force might equalize the theoretically higher tendency for restenosis in crown stents. In this context, also more favorable positive remodeling in crown stents could be important.

PURPOSE: High-resolution MR imaging of the layers of the gastrointestinal wall to provide a foundation for tumor staging based on morphological criteria. MATERIALS AND METHODS: Over a period of 12 months, miscellaneous parts of the gastrointestinal tract of 15 human specimens and 30 porcine specimens were scanned using a 1.5 Tesla clinical MRI scanner combined with an endoluminal receiver coil. The sequences used were T 1-weighted opposed-phase, T 2-weighted turbo spin echo with fat saturation and fast T 2-weighted inversion recovery. The number of differentiable layers, their width and the signal intensity were documented. Then, the results were compared with histological specimens in order to link the imaged wall layers to the anatomical layers. Spearman’s Rank Correlation was used to determine the soundness of the link between the images and their related histology. RESULTS: For both human and animal specimens, the MRI scanning produced 3 to 5, maximum 6 (pig), differentiable layers. The mucosa, submucosa and muscularis could be differentiated with a hyperintense, hypointense and intermediary signal, respectively. The subserosal layer displayed a hypointense signal. CONCLUSION: High-resolution MRI is able to produce differentiable images of the anatomical layers of the gastrointestinal wall in both humans and pigs. Accordingly, it is possible to use MR imaging to diagnose the extent of local tumor infiltration of the gastrointestinal wall.

Summary Magnetic Resonance Imaging (MRI) of the chest and especially the lung is more and more accepted as a valuable additional imaging modality for several pulmonary diseases. Magnetic Resonance Imaging allows for combined morphological and functional imaging and therefore elucidates perfectly the effect of parenchymal changes and destruction onto pulmonary perfusion and ventilation. This overview presents the current status for the application of pulmonary MRI in chronic obstructive pulmonary disease as well as infectious and neoplastic diseases.

Insulinome sind der haufigste Grund fur Hypoglykamien mit endogenem Hyperinsulinismus. Zehn Prozent aller Insulinome – der haufigste endokrine Pankreastumor – kommen im Pankreas als multiple Tumoren vor (z. B. multiple endokrine Neoplasien Typ I) oder erweisen sich selten als Inselzellhyperplasie. Weitere 10–15% sind bei Diagnosestellung maligne. Bildgebende, nichtinvasive Verfahren wie die Computertomographie (CT), die Magnetresonanztomographie (MRT), der Ultraschall (US) und v. a. die Oktreotidszintigraphie sind wegen der geringen Grose der Insulinome vielfach unzureichend zu deren Lokalisation. Invasive praoperative diagnostische funktionelle Verfahren wie die transhepatische peripankreatische venose Blutentnahme (TPVB) und der intraarterielle Kalziumstimulationstest (ASVS) sind, verglichen mit CT, MRT und US, deutlich zeitaufwendigere Methoden, protokollbedingt mit bis zu 2–3 h Untersuchungsdauer, erzielen aber eine exaktere praoperative Lokalisation mit meistens 95%iger Treffsicherheit und hoher und werden daher als Diagnostikum der Wahl zur Abklarung eines Insulinoms angesehen.

The MRI study within the German National Cohort, a large-scale, population-based, longitudinal study in Germany, comprises comprehensive characterization and phenotyping of a total of 30 000 participants using 3-Tesla whole-body MR imaging. A multi-centric study design was established together with dedicated core facilities for e. g. managing incidental findings or providing quality assurance. As such, the study represents a unique opportunity to substantially impact imaging-based risk stratification leading to personalized and precision medicine. Supported by the developments in the field of computational science, the newly developing scientific field of radiomics has large potential for the future. In the present article we provide an overview on population-based imaging and Radiomics and conceptualize the rationale and design of the MRI study within the German National Cohort. Key Points: • Population-based imaging and Radiomics constitute two emerging fields with great oppertunities and challenges for Radiology. • As part of the MRI-study of the NAKO approximately 30 000 subjects will undergo 3 Tesla whole-body MRI. • MR Imaging data is publicly accessable and will provide important insights into the natural history of disease processes and personalized risk profiles of the general population. Citation Format: • Schlett CL, Hendel T, Weckbach S et al. Population-Based Imaging and Radiomics: Rationale and Perspective of the German National Cohort MRI Study. Fortschr Rontgenstr 2016; 188: 652 – 661

Multiplanar reformation (MPR) is the most relevant tool for patient selection and precise procedural planning and also for analyzing postinterventional complications. Curved MPR is used primarily for semiautomated or completely automated calculation of the centerline of the vascular lumen and to estimate the orthogonal vessel diameter and longitudinal extent. Reproducible and accurate measurement of complex pathologies and courses of vessels extends the range of diagnostic radiology. Contemporary scanner consoles allow automated processing of maximum intensity projections (MIP) and standard MPR and their storage in PACS. To improve patient selection, procedural planning, root-cause analysis postoperatively for assessment of treatment effects and to make better communication of findings to nonradiologists possible, volume rendering techniques (VRT) are a beneficial adjunct to source images. With current algorithms semiautomated segmentation is satisfactory for vessels and bones, but not for low-contrast structures (soft tissues), which still need to be segmented manually. In general, isotropic CT source data are preferable to MR images, which are often anisotropic. In many European countries image postprocessing is still not adequately reimbursed although the doctors making referrals often specifically and emphatically demand 3D visualization and measurements in daily practice.

This review presents the basic principles of functional imaging of the central nervous system utilizing magnetic resonance imaging. The focus is set on visualization of different functional aspects of the brain and related pathologies. Additionally, clinical cases are presented to illustrate the applications of functional imaging techniques in the clinical setting. The relevant physics and physiology of contrast-enhanced and non-contrast-enhanced methods are discussed. The two main functional MR techniques requiring contrast-enhancement are dynamic T1- and T2*-MRI to image perfusion. Based on different pharmacokinetic models of contrast enhancement diagnostic applications for neurology and radio-oncology are discussed. The functional non-contrast enhanced imaging techniques are based on "blood oxygenation level dependent (BOLD)-fMRI and arterial spin labeling (ASL) technique. They have gained clinical impact particularly in the fields of psychiatry and neurosurgery.