G W Kauffmann

Heidelberg University, Heidelburg, Baden-Württemberg, Germany

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Publications (366)554.44 Total impact

  • B. Schneider · G. M. Richter · T. Roeren · G. W. Kauffmann
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    ABSTRACT: Introduction: Both thoracic and lumbar sympathectomy and celiac ganglion block could be established as effective methods; side effects are rarely reported. Only the high accuracy of CT-guided positioning can make this possible. Severe side effects are merely sporadic if the proper technique is applied. Material and methods: We used 21G or 22G fine needles. All CT-guided percutaneous neurolysis methods require a proper blood coagulation. Most common CT scanners are suitable for neurolysis if there is enough room for maintaining sterile conditions. All neurolysis methods involve sterile puncture of the ganglia under local anesthesia, a test block with anesthetic and contrast agent to assess the clinical effect and the definitive block with a mixture of 96 % ethanol and local anesthetic. This allows us to correct the position of the needle if we see improper distribution of the test block or unwanted side effects. Though inflammatory complications of the peritoneum due to puncture are rarely seen, we prefer the dorsal approach whenever possible. Results: Seven of 20 legs showed at least transient clinical improvement after CT-guided lumbar sympathectomies; 13 legs had to be amputated. Results of the methods in the literature differ. For lumbar sympathectomy, improved perfusion is reported in 39–89 %, depending on the pre-selection of the patient group. Discussion: It was recently proved that sympathectomy not only improves perfusion of the skin but also of the muscle. The hypothesis of a steal effect after sympathectomy towards skin perfusion was disproved. Modern aggressive surgical and interventional treatment often leaves patients to sympathectomy whose reserves of collateralization are nearly exhausted. We presume this is the reason for the different results we found in our patient group. For thoracic sympathectomy the clinical treatment depends very much on the indications. Whereas palmar hyperhidrosis offers nearly 100 % success, only 60–70 % of patients with disturbance of perfusion have benefited. Results in celiac ganglia block also differ. Patients with carcinoma of the pancreas and other organs of the upper abdomen benefit in 80–100 % of all cases, patients with chronic pancreatitis in 60–80 %. Thorakale und lumbale Sympathikolyse sowie die Zöliakusblockade konnten sich im letzten Jahrzehnt als CT-gesteuerte Neurolyseverfahren aufgrund hoher Zielgenauigkeit in der klinischen Routine etablieren. Irreversible Komplikationen werden bei Einhalten der korrekten Technik und Verwendung dünner 21- oder 22-gg.-Nadeln nur sporadisch beschrieben. Wir beobachteten bei 20 durchgeführten lumbalen Sympathikolysen 7 klinische Verbesserungen und 13 Amputationen. Die Literaturergebnisse der Methode schwanken demgegenüber bei der lumbalen Sympathikolyse von 39–89 % klinischer Erfolgsrate, bei der thorakalen Sympathikolyse von 70–100 % und bei der Zöeliakusblockade von 0–100 %. Die Hypothese, eine Extremitätenerwärmung nach Sympathikolyse sei nur durch Stealeffekte zugunsten der Hautdurchblutung bedingt, konnte durch Flußmessungen widerlegt werden. Während bei der lumbalen Sympathikolyse vor allem die Vorselektion des Patientenguts die unterschiedlichen Erfolgsraten erklärt, spielen bei den anderen Verfahren vor allem die Indikationsstellungen eine herausragende Rolle. Patienten mit palmarer Hyperhidrose profitieren mehr von der perkutanen Neurolyse als Patienten mit Raynaudsymptomatik, Patienten mit Pankreaskarzinom mehr als solche mit Pankreatitis.
    Der Radiologe 09/2014; 36(9):692-699. DOI:10.1007/s001170050129 · 0.41 Impact Factor
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    ABSTRACT: Ziel: Beurteilung eines neuen Bildgebungsverfahrens basierend auf medikamentöser Darmparalyse und maximaler transoraler Wasserdistension von Magen und Duodenum zur Darstellung von Pankreastumoren einschließlich der Tumordetektionsrate, Differentialdiagnostik und Genauigkeit der Resektabilitätsbeurteilung Material und Methode: Von Mai 1994 bis Oktober 1995 wurden 151 konsekutive Patienten mit Verdacht auf Pankreastumor untersucht. Hydro-CT-Technik: Patientenlagerung in 30 ° RAO, Darmparalyse durch 40 mg Buscopan, Magen- und Duodenaldistension mittels 1,5 l Wasser oral, individualisierte Boluskinetik Spiral-CT mit 3 mm Inkrement, 6 mm Tischvorschub und 3 mm Rekonstruktion, 130 ml nichtionisches KM (5 ml/s). Folgende Punkte wurden festgehalten und bewertet: 1. Tumordetektion ja/nein; 2. Differenzierung eines festgestellten Tumors in maligne oder benigne an Hand festgelegter Kriterien; 3. Computertomographische Differentialdiagnostik der Tumoren; 4. Beurteilung der Resektabilität. Bei positivem Tumornachweis wurde als Goldstandard die intraoperative und histologische Bewertung und bei negativem Tumornachweis eine 6 monatige tumorfreie Nachsorgeperiode festgelegt. Ergebnisse: Die Prävalenz einer Raumforderung des Pankreas betrug etwa 38 % in der Gesamtgruppe. Dabei erreichte die Hydro-CT eine Gesamtgenauigkeit in der Tumordetektion von 97,4 % bei einer Sensitivität von 100 % und einer Spezifität von 95,9 %. Bei der Differenzierung eines malignen versus eines benignen Tumors ergab sich eine Gesamtgenauigkeit von 89,7 % bei einer Sensitivität von 92,5 % und einer Spezifität von 83,3 %. 58 Patienten wurden operiert. Die Gesamtgenauigkeit der Resektabilitätsbeurteilung erreichte 95 % bei einer Sensitivität von 90,5 % und einer Spezifität von 100 %. Schlußfolgerungen: Die Hydro-CT des Pankreas in Dünnschicht- und Spiraltechnik mit individueller Anpassung der Kontrastmittelboluskinetik ermöglicht eine hohe Tumordetektionsrate bei einer Steigerung von Sensitivität und Spezifität in der Differentialdiagnostik und Resektabilitsbeurteilung von Pankreastumoren.
    Der Radiologe 05/2013; 36(5):397-405. DOI:10.1007/s001170050088 · 0.41 Impact Factor
  • U. C. Leutloff · S. Eislod · J. P. Schenk · G. Nöldge · J. Schmidt · G. W. Kauffmann
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    ABSTRACT: Klinische Untersuchung: stark reduzierter AZ und EZ, Gewichtsabnahme von mehr als 10 kg während der letzten 3 Wochen (Größe 164 cm, Gewicht 48 kg). Abdomen wirkt eingefallen, epigastrisch sind hochgestellte Darmgeräusche mit stenosetypischer Peristaltik auskultierbar. Bei klinischem Verdacht auf eine adhäsionsbedingte Symptomatik im oberen Dünndarm wird der orale Kostaufbau gestoppt und eine weiterführende Diagnostik eingeleitet. In der Abdomenübersichtsaufnahme Luft in Projektion auf das Duodenum, im übrigen Abdomen nur wenig Luft nachweisbar. Zur weiteren Abklärung Magen-Darm-Passage nach oraler Gabe von wasserlöslichem jodhaltigem Kontrastmittel (Abb. 1). Zusätzlich wurde eine Abdomen-CT durchgeführt. Eine den Darm komprimierende Raumforderung läßt sich nicht nachweisen (Abb. 2).
    Der Radiologe 04/2012; 40(1):83-85. DOI:10.1007/s001170050013 · 0.41 Impact Factor
  • Markus Holtmann · Markus Düx · Günter Kauffmann
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    ABSTRACT: Radiologic evaluation and pathologic finding of colon diseases are main aspects of this article. The radiological examinations of the colon are described including basic technical considerations as well as the significance and restrictions of the diagnostic tests. Following tests are listed: Endoscopy, plain film of the abdomen, sonography, barium study of the colo, Gastrografin® radiography, computertomography, virtual coloscopy, MRI, angiography, endosonography, szintigraphy and FDG-PET. Radiologic tests for polyposis, colorectal cancer, mesenteric ischemia, Crohn's disease, ulcerative colitis, diverticulosis and diverticulitis are described in detail, followed by specific findings with exemplary images.
    DoctorConsult - The Journal. Wissen fur Klinik und Praxis 08/2011; 2(2). DOI:10.1016/j.dcjwkp.2011.03.005
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    ABSTRACT: Paclitaxel is an antiproliferative agent in drug-eluting stents with largely unknown tissue interaction. Toxicity might result from overdosage and/or accumulation. Part 1 of this two-step study investigated how paclitaxel uptake depends on dose density, coronary drug transfer kinetics, and elution efficacy. With cobalt chromium stents and Polyzene-F nanoscale coating, low, intermediate, and high paclitaxel dose densities (25 microg, 50 microg, and 150 microg per stent) were investigated in porcine right coronary arteries (RCAs). Coronary and myocardial tissue concentration measurements and determination of on-stent paclitaxel and plasma concentrations were performed at 2, 8, 24, and 72 hours. For all stents, uptake was similar at all time intervals (paclitaxel RCA concentration range, 1,610-33,300 ng). Low- and intermediate-dose stents showed similar RCA concentrations, but those for high-dose stents were three times greater. Residual on-stent paclitaxel concentration was not time-dependent, at 33.3% on low-, 30.6% on intermediate-, and 17.4% on high-dose stents. Paclitaxel was measurable in only the plasma immediately after stent placement, with a linear dose relationship and a timely regression: measurements in high-dose stents were 0.0454-0.656 ng/mL at 1 minute and 0.0329-0.0879 ng/mL at 5 minutes. Untreated control samples of the left coronary artery showed a linear dose-dependent concentration (12.6 ng/g, 21.2 ng/g, and 85.2 ng/g). Overall coronary paclitaxel uptake is fairly independent from the baseline overall dose density and, hence, depends on immediate binding mechanisms of the arterial wall. This is supported by the fact that, regardless of the applied dose density, the kinetics of paclitaxel uptake did not follow an exposure time pattern.
    Journal of vascular and interventional radiology: JVIR 08/2010; 21(8):1262-70. DOI:10.1016/j.jvir.2010.02.020 · 2.15 Impact Factor
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    ABSTRACT: A prospective study to determine the value of multidetector CT (MD-CT) in assessing the course of nonresectable pancreatic carcinoma during therapy. 26 patients with nonresectable pancreatic carcinoma underwent MD-CT before and after therapy. The examinations were evaluated with regard to tumor size and vascular invasion using an invasion score (IS) by 2 radiologists independently (kappa analysis). Diagnosis was confirmed surgically, by biopsy or clinical course. Sensitivity for the assessment of irresectability was 100%. Following therapy, 54% of all the tumors were smaller (14/26), 42% had increased in volume (11/26), and one tumor remained stable (1/26). The IS (veins) during follow-up changed in 26 patients (portal vein: 5 higher (mean score 10.4/16.2), 4 lower (mean score 17.5/11.5); superior mesenteric vein: 12 higher (11/14.4), 5 lower (16.2/14.6); p = 0.026). The IS (arteries) changed in 13 patients (celiac trunk: 3 higher (3.3/10); hepatic artery: 4 higher (5.7/10.2), 3 lower (11.6/10.3); superior mesenteric artery: 2 higher (4.5/9.5), 1 lower (12/11)). The kappa values were calculated between 0.56 and 0.87. MD-CT is suitable for evaluating tumor spread during therapy for nonresectable pancreatic carcinoma. The IS is useful for assessing the degree of change in vessel invasion.
    Pancreatology 09/2009; 9(5):621-30. DOI:10.1159/000212096 · 2.50 Impact Factor
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    ABSTRACT: High-frequency volumetric Power Doppler ultrasound (HF-VPDU) captures flow-dependent signals in blood vessels and can be used to assess antiangiogenic therapy effects in rodent tumors. However, the sensitivity is limited to vessels larger than capillaries. Contrast-enhanced HF-VPDU reveals all perfused vessels by assessing stimulated acoustic emissions from disintegrating microbubbles. Thus, we investigated whether flow-sensitive and contrast-enhanced HF-VPDU can depict different vessel fractions and assess their early response to antiangiogenic therapy. Mice with A431 tumors were scanned before and after administration of polybutylcyanoacrylate microbubbles by HF-VPDU. Animals received either antiangiogenic treatment (SU11248) or a control substance and were imaged repeatedly over 9 days. At each time point, tumors were removed for immunohistochemical analysis. During growth of untreated tumors, vascularization decreased correspondingly on flow-sensitive and contrast-enhanced scans. Treated tumors showed a significantly (P < 0.05) stronger decline in vascularization than controls, which was more pronounced in contrast-enhanced scans. Surprisingly, whereas vascularization remained low in contrast-enhanced scans, flow-sensitive ultrasound indicated a reincrease after day 6 with a higher vascularization than the controls at day 9. Histologic evaluation indicated that immature vessels degraded markedly on therapy, whereas large mature vessels on the tumor periphery were more therapy resistant and drew closer due to tumor shrinkage. In conclusion, contrast-enhanced HF-VPDU and flow-sensitive HF-VPDU are both capable of assessing the effects of antiangiogenic therapy. Because contrast-sensitive ultrasound is more sensitive for small immature vessels and flow-sensitive ultrasound mostly captures large vessels at the tumor periphery, the combination of both methods can provide evidence of vascular maturity in tumors.
    Cancer Research 10/2008; 68(17):7042-9. DOI:10.1158/0008-5472.CAN-08-0285 · 9.28 Impact Factor
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    ABSTRACT: Cystic echinococcosis is a worldwide disease caused by larval stages of the parasite Echinococcus granulosus (canine tapeworm). In clinical practice, staging of cyst development by ultrasonography (US) has allowed treatment options to be tailored to individual patient needs. However, the empirical correlation between cyst morphology and parasite viability is not always dependable and has, until now, required confirmation by invasive assessment of cyst content by light microscopy (LM), for example. Alternatively, high-field 1H MRS may be used to examine cyst fluid ex vivo and prepare detailed quantitative metabolite profiles, enabling a multivariate metabolomics approach to cyst staging. One-dimensional and two-dimensional 1H and 1H/13C MRS at 600 MHz (14.1 T) was used to analyze 50 cyst aspirates of various US and LM classes. MR parameters and concentrations relative to internal valine were determined for 44 metabolites and four substance classes. The high concentrations of succinate, fumarate, malate, acetate, alanine, and lactate found in earlier studies of viable cysts were confirmed, and additional metabolites such as myo-inositol, sorbitol, 1,5-anhydro-D-glucitol, betaine, and 2-hydroxyisovalerate were identified. Data analysis and cyst classification were performed using univariate (succinate), bivariate (succinate vs fumarate), and multivariate partial least squares discriminant analysis (PSL-DA) methods (with up to 48 metabolite variables). Metabolic classification of 23 viable and 18 nonviable cysts on the basis of succinate alone agreed with LM results. However, for seven samples, LM and MRS gave opposing results. Reclassification of these samples and two unclassified samples by PLS-DA prediction techniques led to a set of 50 samples that could be completely separated into viable and nonviable MRS classes with no overlap, using as few as nine variables: succinate, formate, malate, 2-hydroxyisovalerate, acetate, total protein content, 1,5-anhydro-D-glucitol, alanine, and betaine. Thus, future noninvasive in vivo applications of MRS would appear promising.
    NMR in Biomedicine 08/2008; 21(7):734-54. DOI:10.1002/nbm.1252 · 3.56 Impact Factor
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    ABSTRACT: To evaluate whether dynamic computed tomography (CT)-imaging can provide functional vessel information in patients with chronic aortic dissection type Stanford-B (ADB). In 32 patients, ECG-gated CT-angiography images were obtained. Cross-sectional area change and wall distensibility were investigated by semiautomatic vessel area segmentation at the end of aortic arch. Significance of distensibility differences was tested with regard to the aortic diameter, and the oscillation of the intimal flap was analyzed. The aorta could be segmented successfully in all patients. These were separated into three subgroups: (A) 6 patients with an aortic diameter <4 cm and without a visible intimal flap, (B) 9 patients with an aortic diameter <4 cm, and (C) 17 individuals with an aortic diameter > or = 4 cm; (B) and (C) having a visible intimal flap. Differences in distensibility between the subgroups were not significant. Overall mean distensibility was D(tot)=(1.3+/-0.6) x 10(-5) Pa(-1). Analysis of intimal flap oscillation showed a pulsatile short axis diameter decrease of the true lumen of up to 29%. Dynamic, ECG-gated CT-angiography can demonstrate pulsatile changes in aortic area and a highly variable motion of the intimal flap. Aortic distensibility appears independent of diameter or presence of a intimal flap. Follow-up studies may show correlation with possible complications.
    European journal of radiology 08/2008; 72(1):146-53. DOI:10.1016/j.ejrad.2008.06.024 · 2.16 Impact Factor
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    ABSTRACT: Since limited data is available using MR imaging in cardiac amyloidosis, the purpose of our study was to evaluate morphological and functional differences of the heart using cardiac MRI. 19 consecutive patients (14 males, 5 females, mean age 59 +/- 6 years) with histologically proven cardiac amyloidosis were evaluated with MRI at 1.5 T. Results were compared with data of 10 healthy, age-matched control subjects (5 males, 5 females, mean age 60 +/- 6 years). Functional and morphological data including late enhancement (LE) was acquired. Compared to the control group, patients with cardiac amyloidosis had thickened atrial walls and dilated atriums. Both ventricles and the interventricular septum were thickened. The LV hypertrophy was focal in 11 / 19 (58 %) and global in 4 / 19 (21 %) of patients. A myocardial edema occurred in 2 / 19 patients with cardiac amyloidosis (11 %). An edema of the myocardium was visible in 2 / 19 (11 %) of patients. The LV ejection fraction was statistically significantly decreased. The prevalence of LE was 74 % (14 / 19 of patients). LE was detected predominantly in the LV anterior wall and in the interventricular septum. Within the segments LE was located predominantly in a subendocardial location. Between patients with and without LE no statistically significant differences of functional and morphological results were able to be established. There are three major outcomes of our assessment: 1. The LV hypertrophy is focal in the majority of patients with cardiac amyloidosis. 2. No statistically significant differences can be established in regard to the functional and morphological features between patients with and without LE. 3. Myocardial edema is a possible feature in cardiac amyloidosis.
    RöFo - Fortschritte auf dem Gebiet der R 08/2008; 180(7):639-45. DOI:10.1055/s-2008-1027337 · 1.96 Impact Factor
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    ABSTRACT: Early HAT is the most frequent and severe vascular complication following liver transplantation. It is one of the major causes of graft failure and mortality. Endovascular thrombolytic treatment in patients with thrombotic complications after liver transplantation is an attractive alternative to open surgery as lower morbidity and mortality rates are reported for it. PTA following transcatheter thrombolysis has been successfully used to treat HAT in adults. To the best of our knowledge, there have not been any reports of a successful transcatheter thrombolysis using interventional radiological techniques in a patient only four months old. The present report describes the successful endovascular emergency treatment of a HAT three days after DD split liver transplantation.
    Pediatric Transplantation 08/2008; 12(5):606-10. DOI:10.1111/j.1399-3046.2008.00925.x · 1.63 Impact Factor
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    ABSTRACT: To evaluate the sensitivity and specificity of magnetic resonance imaging (MR imaging) including MR cholangiography for the identification of cysto-biliary fistulas in patients with hepatic hydatid disease. Retrospective analysis of 3 groups of patients (20 patients with 51 echinococcal cysts) in a cohort of 103 patients with cystic echinococcosis with different pretest probabilities for cysto-biliary fistulas. Patients who had MR imaging/MR cholangiography with symptoms and signs of biliary obstruction (5 patients with 16 cysts, group I), before surgery for other reasons than biliary obstruction (9 patients with 14 cysts, group II) and for cyst staging (6 patients with 21 cysts, group III). All MR images were evaluated before surgery for the presence of cyst wall defects and hydatid debris in bile ducts. In groups I and II MR results were compared with surgical, parasitological, and biochemical findings of each individual cyst. Based on direct (i.e. defects in the cyst wall and continuity of dilated biliary ducts into adjacent cysts), and indirect MR imaging/MR cholangiography imaging signs (i.e. intraluminal debris) our best estimate of sensitivity and specificity (stage-specific, WHO type CE3 and CE4) for cysto-biliary fistulas was 75% and 95%, respectively. MR imaging with MR cholangiography is a valuable non-invasive imaging technique to assess the risk of cysto-biliary fistula-related complications and for planning of surgery.
    European Journal of Radiology 06/2008; 66(2):262-7. DOI:10.1016/j.ejrad.2007.08.002 · 2.16 Impact Factor
  • T Heye · P Kurz · M Eiers · G W Kauffmann · A Schipp
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    ABSTRACT: Evaluation of an interactive, multimedia case-based learning platform for the radiological education of medical students. An interactive electronic learning platform for the education of medical students was built in HTML format independent of the operating system in the context of the Heidelberg Curriculum Medicinale (HeiCuMed). A case collection of 30 common and authentic clinical cases is used as the central theme and clinical background. The user has to work on each case by making decisions regarding a selection of diagnostic modalities and by analyzing the chosen studies. After a reasonable selection and sequence of diagnostic radiological modalities and their interpretation, a diagnosis has to be made. An extensive collection of normal findings for any modality is available for the user as a reference in correlation with the pathology at anytime within each case. The case collection consists of 2053 files with 1109 Internet pages (HTML) and 869 image files (.jpeg) with approximately 10 000 crosslinks (links). The case collection was evaluated by a questionnaire (scale 1 - 5) at the end of the radiological student course. The development of the results of the radiological course exam was analyzed to investigate any effect on the learning performance after the case collection was introduced. 97.6 % of the course participants would use the case collection beyond the radiological student course to learn radiology in their medical studies. The handling of the case collection was rated excellent in 36.9 %, good in 54.6 %, satisfactory in 8 % and unsatisfactory in 0.4 %. 41 % felt that the case collection was overall excellent, 49.2 % good, 7.8 % satisfactory, 1.6 % unsatisfactory and 0.4 % poor. A positive trend in the development of the results in the radiological course exam with less variance after the introduction of the case collection was found but failed statistical significance. A platform-independent, interactive, multimedia learning platform with authentic clinical cases and multiple choice elements for the user is the ideal method for supporting and expanding medical education in radiology. The usefulness and the reasonable exertion of diagnostic modalities are conveyed in a practical context as teaching goals. The high acceptance among students is based on the interactivity and use of multimedia.
    RöFo - Fortschritte auf dem Gebiet der R 05/2008; 180(4):337-44. DOI:10.1055/s-2008-1027217 · 1.96 Impact Factor
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    ABSTRACT: To detect distensibility changes that might be an indicator for an increased risk of rupture, cross-sectional area changes of abdominal aortic aneurysms (AAA) have been determined using ECG-gated CT. Distensibility measurements of the aorta were performed in 67 patients with AAA. Time-resolved images were acquired with a four detector-row CT system using a modified CT-angiography protocol. Pulsatility-related cross-sectional area changes were calculated above and at AAA level by semiautomatic segmentation; distensibility values were obtained using additional systemic blood pressure measurements. Values were compared for small Ø<5 cm (n=44) and large Ø>5 cm (n=23) aneurysms. The aorta could be segmented successfully in all patients. Upstream AAA distensibility D was significantly higher than at AAA level for both groups: means above AAA (at AAA) D(above)=(1.3+/-0.8) x 10(-5) Pa(-1) (D(AAA )=(0.6+/-0.5) x 10(-5) Pa(-1)) t-test p(D)<0.0001. Differences of the distensibility between smaller and larger aneurysms were not found to be significant. Distensibility can be measured non-invasively with ECG-gated CT. The reduction of distensibility within aneurysms compared to normal proximal aorta is subtle; the lack of difference between both small and large aneurysms suggests that this reduction occurs early in the aneurysm's development. Hence, reduced distensibility might be a predictive parameter in patients with high risk of aortic disease.
    European Radiology 05/2008; 18(5):966-73. DOI:10.1007/s00330-007-0833-5 · 4.34 Impact Factor
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    ABSTRACT: To prospectively compare diagnostic parameters of a newly developed endoluminal MRI (endo-MRI) concept with endoscopic ultrasound (EUS) and hydro-computer tomography (Hydro-CT) in T-staging of gastric carcinoma on one patient collective. 28 consecutive patients (11 females, 17 males, age range 46-87 years, median 67 years) referred for surgery due to a gastric malignancy were included. Preoperative staging by EUS was performed in 14 cases and by Hydro-CT in 14 cases within a time frame of 2 weeks. Ex vivo endo-MRI examination of gastric specimens was performed directly after gastrectomy within a time interval of 2-3h. EUS data were acquired from the clinical setting whereas Hydro-CT and endo-MRI data were evaluated in blinded fashion by two experienced radiologists and one surgeon well experienced in EUS on gastric carcinomas. Histopathology resulted in 4 pT1, 17 pT2, 3 pT3 and 2 pT4 carcinomas with 2 gastric lymphomas which were excluded. Overall accuracy for endo-MRI was 75% for T-Staging of the 26 carcinomas. EUS achieved 42.9% accuracy; endo-MRI in this subgroup was accurate in 71.4%. Hydro-CT was correct in 28.6%, accuracy for endo-MRI in this subgroup was 71.4%. The direct comparison of all three modalities on one patient collective shows that endo-MRI is able to achieve adequate staging results in comparison with clinically accepted methods like EUS and Hydro-CT in classifying the extent of tumor invasion into the gastric wall. However the comparison is limited as we compared in vivo routine clinical data with experimental ex vivo data. Future investigations need to show if the potential of endo-MRI can be transferred into a clinical in vivo setting.
    European journal of radiology 04/2008; 70(2):336-41. DOI:10.1016/j.ejrad.2008.01.037 · 2.16 Impact Factor
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    ABSTRACT: To assess the pharmacodynamic behavior of cyanoacrylate, streptavidin-coated microbubbles (MBs) and to investigate their suitability for molecular ultrasound imaging. Biodistribution of MBs was analyzed in tumor-bearing mice using gamma-counting, immunohistochemistry, flow cytometry, and ultrasound. Further, vascular endothelial growth factor receptor 2-antibody coupled MBs were used to image tumor neovasculature. After 1 minute >90% of MBs were cleared from the blood and pooled in the lungs, liver, and spleen. Subsequently, within 1 hour a decent reincrease of MB-concentration was observed in the blood. The remaining MBs were removed by liver and spleen macrophages. About 30% of the phagocytosed MBs were intact after 48 hours. Shell fragments were found in the kidneys only. No relevant MB-accumulation was observed in tumors. In contrast, vascular endothelial growth factor receptor 2-specific MBs accumulated significantly within the tumor vasculature (P < 0.05). The pharmacokinetic behavior of streptavidin-coated cyanoacrylate MBs has been studied. In this context, the low amount of MBs in tumors after >5 minutes is beneficial for specific targeting of angiogenesis.
    Investigative Radiology 04/2008; 43(3):162-9. DOI:10.1097/RLI.0b013e31815a251b · 4.45 Impact Factor
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    ABSTRACT: The objective of this study was to evaluate inflammatory response and recanalization after embolization with a new spherical embolic agent based on a core and shell design with a hydrogel core of polymethylmethacrylate (PMMA) and a Polyzene-F nanoscale coating in a porcine kidney model. Thirty-six minipigs were enrolled for superselective renal embolization. Polyzene-F-coated PMMA particles and uncoated PMMA particles with a diameter of 300-600 mum were used. Either 4 or 12 weeks post-embolization, arteriography of the embolized kidneys was performed and then compared with pre- and immediate post-embolization arteriograms using a specific recanalization score to determine the extent of recanalization. Using a microscopic inflammation score (Banff classification), the embolized organs were examined for local inflammatory effects which occurred in response to the embolic agent. In Polyzene-F-coated particles, the Banff classification showed an average inflammation score of 0.26 +/- 0.58 at 4 weeks and of 0.08 +/- 0.28 at 12 weeks. In uncoated particles, the Banff score measured 0.37 +/- 0.6 at 4 weeks, which was higher, but without a statistically significant difference. According to the recanalization score used in this study, mild angiographic recanalization was evident in all groups, without statistically significant differences (3.0 +/- 0.71 in coated particles, 3.09 +/- 0.81 in uncoated particles; p = 0.74). We conclude that both uncoated hydrogel particles and Polyzene-F-coated embolic agents triggered virtually no inflammatory response and effectively occluded target arteries. This study demonstrates good biocompatibility of the new embolic material. As in other spherical embolic agents, recanalization can occur to some degree.
    CardioVascular and Interventional Radiology 02/2008; 31(4):799-806. DOI:10.1007/s00270-007-9268-2 · 1.97 Impact Factor
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    ABSTRACT: It was the aim of this study to evaluate a new infiltration score to determine the resectability of pancreatic carcinomas in preoperative planning. Eighty patients with suspected pancreatic tumor were examined prospectively using 16-row spiral CT. The scans were evaluated for the presence of pancreatic carcinoma, peripancreatic tumor extension and vascular invasion using a standardized questionnaire. Invasion of the surgically relevant vessels was evaluated using a new invasion score. The operative and histological findings and the clinical follow-up served as the gold standard. Forty patients had a pancreatic carcinoma, 5 had metastasis of a different primary tumor, and in 35 patients, there was no malignant pancreatic disease. The sensitivity for tumor detection was 100%, with a specificity of 88% for differentiating between malignant and benign pancreatic tumors. Invasion of the surrounding vessels was evaluated correctly using the invasion score, with a sensitivity of 89% and a specificity of 99%. In evaluation of resectability, a sensitivity of 94% and a specificity of 89% were achieved. Using 16-row spiral CT, the invasion score is a valid tool for correctly assessing invasion in relevant vessels in cases of pancreatic carcinoma and for determining resectability.
    Pancreatology 02/2008; 8(2):204-10. DOI:10.1159/000128557 · 2.50 Impact Factor
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    ABSTRACT: Molecular ultrasound is capable of elucidating the expression of angiogenic markers in vivo. However, the capability of the method for volumetric "multitarget quantification" and for the assessment of antiangiogenic therapy response has rather been investigated. Therefore, we generated cyanoacrylate microbubbles linked to vascular endothelial growth factor receptor 2 (VEGFR2) and alphavbeta3 integrin binding ligands and quantified their accumulation in squamous cell carcinoma xenografts (HaCaT-ras-A-5RT3) in mice with the quantitative volumetric ultrasound scanning technique, sensitive particle acoustic quantification. Specificity of VEGFR2 and alphavbeta3 integrin binding microbubbles was shown, and changes in marker expression during matrix metalloproteinase inhibitor treatment were investigated. In tumors, accumulation of targeted microbubbles was significantly higher compared with nonspecific ones and could be inhibited competitively by addition of the free ligand in excess. Also, multimarker imaging could successfully be done during the same imaging session. Molecular ultrasound further indicated a significant increase of VEGFR2 and alphavbeta3 integrin expression during tumor growth and a considerable decrease in both marker densities after matrix metalloproteinase inhibitor treatment. Histologic data suggested that the increasing VEGFR2 and alphavbeta3 integrin concentrations in tumors during growth are related to an up-regulation of its expression by the endothelial cells, whereas its decrease under therapy is more related to the decreasing relative vessel density. In conclusion, targeted ultrasound appears feasible for the longitudinal molecular profiling of tumor angiogenesis and for the sensitive assessment of therapy effects in vivo.
    Molecular Cancer Therapeutics 02/2008; 7(1):101-9. DOI:10.1158/1535-7163.MCT-07-0409 · 6.11 Impact Factor
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    ABSTRACT: The purpose of this study was to evaluate the safety and efficacy of percutaneous transhepatic portal vein embolization of the right portal vein with an Ethibloc/Lipiodol mixture to induce hypertrophy of the left liver lobe in patients with primarily unresectable liver tumor. 15 patients (8 primary liver tumors, 7 liver metastases) underwent portal vein embolization. Liver volumetry, duration of hospitalization, complication rates, relevant laboratory values were documented. In 13/15 patients (84.6%) embolization could be performed with a median of 8.8 ml (range 1.5-28 ml) Ethibloc/Lipiodol. One minor procedure-related complication (subcapsular hematoma) occurred, which did not affect the two-step liver resection. No patient developed acute liver failure after embolization or liver resection. The volume of the left liver lobe increased significantly (p = 0.0015) by 25% from a median of 750 ml (587-1,114 ml) to 967 ml (597-1,249 ml). 11/13 (81.8%) of the embolized patients underwent liver resection at a median of 49 days after embolization. Median hospitalization time was 4 days after embolization and 7 days after liver resection. Median overall survival of the 11 operated patients was 376 days. Percutaneous transhepatic portal vein embolization using an Ethibloc/Lipiodol mixture is a safe, feasible, and efficient interventional procedure.
    Digestive surgery 02/2008; 25(1):52-9. DOI:10.1159/000118795 · 1.74 Impact Factor

Publication Stats

2k Citations
554.44 Total Impact Points

Institutions

  • 1991–2010
    • Heidelberg University
      • • University Hospital of Radiology
      • • Department of Diagnostic and Interventional Radiology
      • • Surgical Clinic
      Heidelburg, Baden-Württemberg, Germany
    • University of Tuebingen
      Tübingen, Baden-Württemberg, Germany
  • 2005
    • University of Washington Seattle
      Seattle, Washington, United States
  • 1988
    • Clinic for Tumor Biology Freiburg
      Freiburg, Baden-Württemberg, Germany
  • 1984–1985
    • University of Freiburg
      • Institute of Psychology
      Freiburg, Baden-Württemberg, Germany