Peter Seidensticker

Bayer HealthCare, Leverkusen, North Rhine-Westphalia, Germany

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Publications (34)94.7 Total impact

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    ABSTRACT: To assess the effect of low-osmolar, monomeric contrast media with different iodine concentrations on bolus shape in aortic CT angiography. Repeated sequential computed tomography scanning of the descending aorta of eight beagle dogs (5 male, 12.7±3.1kg) was performed without table movement with a standardized CT scan protocol. Iopromide 300 (300mgI/mL), iopromide 370 (370mgI/mL) and iomeprol 400 (400mgI/mL) were administered via a foreleg vein with an identical iodine delivery rate of 1.2gI/s and a total iodine dose of 300mgI/kg body weight. Time-enhancement curves were computed and analyzed. Iopromide 300 showed the highest peak enhancement (445.2±89.1 HU), steepest up-slope (104.2±17.5 HU/s) and smallest full width at half maximum (FWHM; 5.8±1.0s). Peak enhancement, duration of FWHM, enhancement at FWHM and up-slope differed significantly between iopromide 300 and iomeprol 400 (p<0.05). Except for enhancement at FWHM there were no significant differences between iopromide 300 and iopromide 370 and iopromide 370 and iomeprol 400 (p>0.05). Low viscous iopromide 300 results in a better defined bolus with a significantly higher peak enhancement, steeper up-slope and smaller FWHM when compared to iomeprol 400. These characteristics potentially affect contrast timing.
    European journal of radiology 01/2012; 81(4):e629-32. DOI:10.1016/j.ejrad.2011.12.038 · 2.65 Impact Factor
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    ABSTRACT: Computed tomography angiography source imaging (CTA-SI) in acute ischemic stroke improves detection rate and estimation of extent of cerebral infarction. This study compared the new components color-coded perfusion weighted map (PWM) and color-coded perfused blood volume (PBV) derived from CTA data with CTA-SI for the visualization of cerebral infarction. Fifty patients (women = 30; mean age = 74.9 ± 13.3 years) underwent nonenhanced computed tomography and CTA for suspected acute ischemic stroke. PWM, PBV, and CTA-SI were reconstructed with identical slice thickness of 1.0 mm with commercial software. Extent of infarction was measured using the Alberta Stroke Program Early Computed Tomography Score (ASPECTS). For statistical analysis, Spearman's R correlation and paired-samples t-test was used. P < .05 was considered significant. PBV had superior sensitivity for detection of cerebral infarction with 0.88 compared to PWM and CTA-SI with 0.79 and 0.76, respectively. The accuracy of correct diagnosis was superior for PBV with 0.82 compared to PWM and CTA-SI with 0.76, respectively. ASPECTS of PWM and PBV showed strong correlation with CTA-SI with r = 0.903 (P < .001) and r = 0.866 (P < .001), respectively. Mean ASPECTS of CTA-SI (6.24 ± 3.62) revealed no significant difference with PWM (6.26 ± 3.45), but a significant difference with PBV (5.62 ± 3.41; P < .02). PWM was equal to CTA-SI in detection of cerebral infarction and estimation of extent of cerebral ischemia. Although PBV was superior to CTA-SI in detection of cerebral infarction, PBV seems to overestimate the extent of critical cerebral ischemia. Therefore, CTA-SI information is not identical to PBV and further clinical evaluation is mandatory.
    Academic radiology 03/2011; 18(3):347-52. DOI:10.1016/j.acra.2010.10.013 · 2.09 Impact Factor
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    ABSTRACT: The purpose of this article is to prospectively assess the frequency and type of IV injection site complications associated with high-flow power injection of nonionic contrast medium in MDCT. Contrast-enhanced (300-370 mg iodine/mL) MDCT examinations with high flow rates (up to 8 mL/s) using automatic CT injectors were performed according to standardized MDCT protocols. The location, type, and size (16-24 gauge) of IV catheters and volumes, iodine concentration, and flow rates of contrast medium were documented. Patients were questioned about associated discomfort, IV catheter sites were checked, and adverse effects were recorded. Prospectively, 4,457 patients were studied. The injection rate ranged from 1-2.9 mL/s (group 1; n = 1,140) to 3-4.9 mL/s (group 2; n = 2,536) to 5-8 mL/s (group 3; n = 781); 1.2% of the patients experienced extravasations (n = 52). Contrast medium iodine concentration, flow rates, and volumes were not related to the frequency of extravasation. The extravasation rate was highest with 22-gauge IV catheters (2.2%; p < 0.05) independently of the anatomic location. For 20-gauge IV catheters, extravasation rates were significantly higher in the dorsum of the hand than in the antecubital fossa (1.8% vs 0.8%; p = 0.018). Extravasation rates were higher in older patients (≥ 50 vs < 50 years, 0.6% vs 1.4%; p = 0.019). Different iodine concentrations did not trigger significant differences in contrast material reactions (p = 0.782). Automated IV contrast injection applying high flow rates (i.e., up to 8 mL/s) is performed without increased risk of extravasation. The overall extravasation rate was 1.2% and showed no correlation with iodine concentration, flow rates, or contrast material reactions. Performing high flow rates with low-diameter IV catheters (e.g., 22-gauge catheters) and a location of IV catheter in the hand is associated with a higher extravasation rate.
    American Journal of Roentgenology 10/2010; 195(4):825-9. DOI:10.2214/AJR.09.3739 · 2.74 Impact Factor
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    ABSTRACT: To evaluate the impact of bone subtraction computed tomography angiography (BS-CTA) for the assessment of transcranial arteries in comparison with standard CTA (S-CTA) without bone removal and time-of-flight magnetic resonance angiography (TOF-MRA). Cranial unenhanced CT and S-CTA were performed in 53 patients with suspected cerebrovascular disease. BS-CTA datasets were reconstructed from the S-CTA and unenhanced CT source images. TOF-MRA was performed within 24h after CTA on a 1.5 T MRI system. Two radiologists, in consensus, evaluated the segments of the internal carotid artery (C2-C7), the vertebral artery (V4), and the basilar artery for the degree of stenosis. A five-step scale (0-49, 50-69, 70-89, 90-99% and occlusion) for the degree of stenosis was applied for all segments. Wilcoxon's signed rank test was used for statistical analysis. Seven hundred and fifty vessel segments (ICA:636, VA:106, BA:53) were analysed. The degree of stenosis on S-CTA was consistent with TOF-MRA in all segments. BS-CTA showed a trend towards higher stenosis scores in cases of calcified plaques compared to S-CTA (p=0.11) and TOF-MRA (p=0.09), which was not statistically significant. In transcranial segments, BS-CTA revealed equivalent scores compared to S-CTA and TOF-MRA (p=0.25; p=0.20). BS-CTA produced similar results to TOF-MRA and S-CTA and can be applied as a non-invasive imaging method for the transcranial arteries. However, BS-CTA shows a trend towards overestimation of the degree of stenosis.
    Clinical Radiology 06/2010; 65(6):440-6. DOI:10.1016/j.crad.2010.03.002 · 1.66 Impact Factor
  • Hubertus Pietsch, Ute Hübner‐Steiner, Peter Seidensticker
    Ullmann's Encyclopedia of Industrial Chemistry, 04/2010; , ISBN: 9783527306732
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    ABSTRACT: This study determines the value of whole brain color-coded three-dimensional perfused blood volume (PBV) computed tomography (CT) for the visualization of the infarcted tissue in acute stroke patients. Nonenhanced CT (NECT), perfusion CT (PCT), and CT angiography (CTA) in 48 patients with acute ischemic stroke were performed. Whole brain PBV was calculated from NECT and CTA data sets using commercial software. PBV slices in identical orientation to the PCT slices were reconstructed and the area of visual perfusion abnormality on PBV maps was measured. The infarct core in the corresponding PCT slices (CBV <2.0 mL/100 g) was measured automatically with commercial software. The ischemic area on PBV and the infarct core on quantitative PCT were compared using the Pearsons-R correlation coefficient. Significance was considered for P < .05. The quantitative PCT demonstrated a mean infarct core volume of 35.48 +/- 32.17 cm(3), whereas the volume of visual perfusion abnormality of the corresponding PBV slices was 37.16 +/- 37.59 cm(3). The perfusion abnormality in PBV was highly correlated with the infarct core of quantitative PCT for area per slice (r = 0.933, P < .01) as well as volume (r = 0.922, P < .01). PBV can serve as surrogate marker corresponding to the infarct core in acute stroke with whole brain coverage.
    Academic radiology 04/2010; 17(4):427-32. DOI:10.1016/j.acra.2009.11.005 · 2.09 Impact Factor
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    ABSTRACT: To prospectively investigate the influence of contrast material concentration on enhancement in cardiac CT by using a biphasic single-injection protocol. Sixty-four-row multidetector cardiac CT angiography was performed in 159 patients randomised to a moderate or high contrast medium concentration. Contrast material injection included a first phase for enhancement of the coronary arteries and a second phase, at half the iodine flux, targeted at enhancement of the right ventricle. Contrast medium injection was followed by a saline flush. For both concentrations, injection duration (and thus total iodine dose) was adapted to the duration of the CT data acquisition and iodine flux was adjusted to patient weight. Attenuation was measured at various levels in the heart and vessels and the two concentrations compared, overall and per weight group. Enhancement of the aorta and left ventricle was significantly greater with the moderate than with the high concentration contrast medium. This remained true for the two higher weight groups. No difference was found in the lowest weight group or in the right ventricle and pulmonary outflow tract. With a biphasic injection protocol, enhancement of the aorta and left ventricle was weaker with the higher concentration of contrast material.
    European Radiology 03/2010; 20(8):1917-25. DOI:10.1007/s00330-010-1752-4 · 4.34 Impact Factor
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    ABSTRACT: To compare intra-individual contrast enhancement in multi-detector-row computed tomography (MDCT) using contrast media (CM) containing 300, 370 and 400 mg iodine per ml (mgI/ml). Six pigs underwent repeated chest MDCT using three different CM (iopromide 300, iopromide 370, iomeprol 400). An identical iodine delivery (IDR) rate of 1.5 gI/s and a constant total iodine dose of 300 mg/kg body weight were used. Dynamic CT were acquired at the level of the pulmonary artery, and the ascending and descending aorta. After the time enhancement curves were computed, the pulmonary and aortic peak enhancement, time to peak and plateau time above 300 HU were calculated. Intra-individual peak contrast enhancement was significantly higher for the 300 mgI/ml contrast medium compared with the 370 and 400 mgI/ml media: pulmonary trunk 595 HU vs 516 HU (p = 0.0093) vs 472 HU (p = 0.0005), and aorta 505 HU vs 454 HU (p = 0.0008) vs 439 HU (p = 0.0001), respectively. Comparison of time to peaks showed no significant difference. Plateau times were significantly longer for the 300 mgI/ml than for the 370 and 400 mgI/ml CM at all anatomical sites. Given normalised IDR and total iodine burden, the use of CM with a standard concentration with 300 mg iodine/ml provides improved contrast enhancement compared with highly concentrated CM in the chest.
    European Radiology 02/2010; 20(7):1644-50. DOI:10.1007/s00330-010-1717-7 · 4.34 Impact Factor
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    ABSTRACT: Computed tomography angiography (CTA) is a well-accepted imaging modality to evaluate the supraaortic vessels. Initial reports have suggested that dual energy CTA (DE-CTA) can enhance diagnosis by creating bone-free data sets, which can be visualized in 3D, but a number of limitations of this technique have also been addressed. We sought to describe the performance of DE-CTA of the supraaortic vessels with a novel dual source CT system with special emphasis on image quality and post-processing related artifacts. Thirty-three patients underwent carotid CT angiography on a second generation dual source CT system. Simultaneous acquisitions of 100 and 140kV data sets in arterial phase were performed. Two examiners evaluated overall bone suppression with a 3-point scale (1=poor; 3=excellent) and image quality regarding integrity of the vessel lumen of different vessel segments (n=26) with a 5-point scale (1=poor; 5=excellent), CTA source data served as the reference. Excellent bone suppression could be achieved in the head and neck. Only minor bone remnants occurred, mean score for bone removal was 2.9. Mean score for vessel integrity was 4.3. Eight hundred fifty-seven vessel segments could be evaluated. Six hundred thirty-five segments (74%) showed no lumen alteration, 65 segments (7.6%) lumen alterations <10%, 27 segments (3.1%) lumen alterations >10% resulting in a total luminal reduction <50%, 17 segments (2%) lumen alterations of more than 10% resulting in a total luminal reduction >50%, and 113 segments (13.2%) showed a gap in the vessel course (100% total lumen reduction). Artificial gaps of the vessel lumen occurred in 28 vessel segments due to artifacts caused by dental hardware and in all but one (65) ophthalmic arteries. Excellent bone suppression could be achieved, DE imaging with 100 and 140kV lead to improved image quality and vessel integrity in the shoulder region than previously reported. The ophthalmic artery still cannot be adequately visualized.
    European journal of radiology 10/2009; 76(2):e6-12. DOI:10.1016/j.ejrad.2009.09.022 · 2.65 Impact Factor
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    ABSTRACT: Noninvasive imaging is increasingly accepted for the evaluation of atherosclerotic disease of the carotid arteries. We sought to evaluate the feasibility of a low-contrast media volume protocol for carotid computed tomography angiography (CTA) using a 128-slice-spiral-computed tomography scanner with a gantry rotation time of 300 milliseconds. Thirty consecutive patients underwent CTA for the evaluation of the carotid vessels, with a 128-section scanner. Fifteen patients were examined with a standard volume contrast injection protocol (group A): 80 mL of contrast material (CM) were injected at 5 mL/s using the test bolus method to assess individual transit time. Another 15 patients were examined with a low-volume contrast media protocol (group B): 30 mL CM were injected at 4 mL/s using bolus tracking to trigger the CTA acquisition. In both groups, contrast administration was followed by a saline flush. Image quality and segmental vascular enhancement as well as the presence and degree of arterial stenosis were independently evaluated by 2 radiologists. Venous enhancement and streak artifacts at the thoracic inlet because of highly concentrated CM in the subclavian veins were evaluated in both groups. Kappa statistic and Pearson correlation coefficient were used to quantify interobserver variability. Qualitative data were compared using the Wilcoxon signed rank test and student t test was used to investigate differences in segmental vessel attenuation. All studies were of diagnostic quality in both groups. Interobserver agreement was high (kappa = 0.82, group A; kappa = 0.78, group B). Attenuation measurement showed excellent interobserver correlation in both groups (r > 0.9). Mean enhancement values were slightly higher in group A, but without statistical significance when averaged for all segments (P = 0.06). Streak artifacts impaired evaluation of 13 adjacent arterial segments in 8 patients at the level of the thoracic inlet in group A. In group B, only 1 segment was rated insufficient by both radiologists. Venous enhancement was significantly lower in group B (P = 0.04). The low-contrast protocol proved to be the more robust method with constant high arterial enhancement, less streak artifacts at the thoracic inlet, and less venous overlay. Using the latest CT technology, optimal depiction of the craniocervical arteries can be archived with a low-volume (30 mL) CM protocol.
    Investigative radiology 05/2009; 44(5):257-64. DOI:10.1097/RLI.0b013e31819b08a0 · 4.85 Impact Factor
  • RöFo - Fortschritte auf dem Gebiet der R 04/2009; 181. DOI:10.1055/s-0029-1221391 · 1.96 Impact Factor
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    ABSTRACT: We sought to intraindividually compare intravascular contrast enhancement in multidector computed tomography (MDCT) of the chest using contrast media (CM) containing 300 and 400 mg iodine/ml. Seventy-one patients underwent repeated MDCT scanning of the chest at baseline and follow-up. CM with standard iodine (protocol A: 300 mg iodine/ml; Iopromide 300) and high iodine concentration (protocol B: 400 mg iodine/ml; Iomeprol 400) were used. The iodine delivery rate (1.29 g iodine/s) and total iodine load (37 g iodine) were identical for the two protocols. Contrast enhancement was measured in the right and left ventricles, pulmonary trunk, right and left pulmonary arteries, and ascending and descending aortas. Results were compared using paired t-tests; P values were adjusted using Bonferroni correction (P <or= .005). Contrast enhancement values showed no statistically significant differences between the two protocols at all anatomic sites (all P > .005). In the right ventricle, pulmonary trunk, and right and left pulmonary arteries, higher attenuation values for protocol A were detected compared to protocol B (379.0 +/- 110.5 vs. 349.8 +/- 117.6, 354.5 +/- 112.2 vs 330.9 +/- 118.3, 348.6 +/- 106.0 vs. 321.8 +/- 109.9, and 347.9 +/- 102.4 vs. 321.0 +/- 104.9 HU, respectively). After the lung circulation (left ventricle, ascending aorta, and descending aorta), attenuation values were marginally higher for protocol B. Using both protocols resulted in suitable contrast enhancement with a mean pulmonary attenuation higher than 300 HU. Using an adapted injection protocol, the administration of 300 and 400 mg iodine CM resulted in a suitable intravascular contrast enhancement in the chest. The use of 400 mg iodine CM does not lead to a statistically significant improvement in contrast enhancement compared to the 300 mg iodine CM.
    Academic radiology 02/2009; 16(2):144-9. DOI:10.1016/j.acra.2008.05.008 · 2.09 Impact Factor
  • Christiane Pering, Philipp Lengsfeld, Peter Seidensticker
    Radiology 02/2009; 250(1):298-9; author reply 299. DOI:10.1148/radiol.2501081329 · 6.21 Impact Factor
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    ABSTRACT: Commercially available iodinated contrast media (CM) show significantly different physico-chemical properties. The relevance of the viscosity of CM may be underestimated as a contributing factor for clinically relevant renal failure as suggested by a large registry data analysis (Swedish registry study). The objective of this preclinical study is to assess differences of a low and high-viscous CM regarding their retention time in the kidney. Furthermore, we investigated the expression of marker genes for renal damage and hypoxia to evaluate a potential renal damage and hypoxia after application of iodinated CM. After application of Iopromide 300 and Iodixanol 320 CM, the iodine concentration over time was determined using computed tomography and x-ray fluorescence analysis in healthy Han Wistar and renally impaired ZSF1 rats. The latter served as a model for age and diabetes-related renal impairment. X-ray attenuation (Hounsfield units) in the renal cortex was analyzed by 2 independent blinded readers. Furthermore, the expression of kidney injury molecule 1 (Kim-1/Havcr1) and heme oxygenase I (HO-1/HMOX1) was measured by quantitative reverse transcription-polymerase chain-reaction. Computed tomography and x-ray fluorescence analysis in the kidneys of animals treated with Iodixanol revealed significantly prolonged retention of iodine in the kidney as compared with animals treated with Iopromide. This difference was even more pronounced in renally impaired rats. Twenty-four hours after Iodixanol treatment, significantly increased levels of Kim-1/Havcr1 and HO-1/HMOX1 transcript levels were observed compared with the saline and Iopromide treatment. A prolonged retention of contrast media in the kidney was observed after administration of dimeric CM (Iodixanol 320). One possible explanation for this effect could be the high viscosity of the dimeric CM (Iodixanol 320) and the lack of dilution by osmotic diuresis. This prolonged exposure is possibly associated with higher renal toxicity as indicated by the elevated expression of biomarkers for hypoxia and renal injury.
    Investigative radiology 01/2009; 44(2):114-23. DOI:10.1097/RLI.0b013e318190fbd2 · 4.85 Impact Factor
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    ABSTRACT: Previous experiences of whole body MR angiography are predominantly available in linear 0.5 M gadolinium-containing contrast agents. The aim of this study was to compare image quality on a four-point scale (range 1-4) and diagnostic accuracy of a 1.0 M macrocyclic contrast agent (gadobutrol, n = 80 patients) with a 0.5 M linear contrast agent (gadopentetate dimeglumine, n = 85 patients) on a 1.5 T whole body MR system. Digital subtraction angiography served as standard of reference. All examinations yielded diagnostic image quality. There was no significant difference in image quality (3.76 +/- 0.3 versus 3.78 +/- 0.3, p = n.s.) and diagnostic accuracy observed. Sensitivity and specificity of the detection of hemodynamically relevant stenoses was 93%/95% in the gadopentetate dimeglumine group and 94%/94% in the gadobutrol group, respectively. The high diagnostic accuracy of gadobutrol in the clinical routine setting is of high interest as medical authorities (e.g. the European Agency for the Evaluation of Medicinal Products) recommend macrocyclic contrast agents especially to be used in patients with renal failure or dialysis.
    Journal of Cardiovascular Magnetic Resonance 01/2009; 10(1):63. DOI:10.1186/1532-429X-10-63 · 4.44 Impact Factor
    This article is viewable in ResearchGate's enriched format
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    ABSTRACT: In computed tomography (CT) several contrast media with different iodine concentrations are available. The aim of this study is to prospectively compare contrast media with iodine concentrations of 300, 370 and 400 mg iodine/ml for chest- CT. 300 consecutive patients were prospectively enrolled, under a waiver of the local ethics committee. The first (second, third) 100 patients, received contrast medium with 300 (370, 400) mg iodine/ml. Injection protocols were adapted for an identical iodine delivery rate (1.3 mg/s) and total iodine load (33 g) for all three groups. Standardized MDCT of the chest (16 x 0.75 mm, 120 kVp, 100 mAseff.) was performed. Intravascular attenuation values were measured in the pulmonary trunk and the ascending aorta; subjective image quality was rated on a 3-point-scale. Discomfort during and after injection was evaluated. There were no statistically significant differences in contrast enhancement comparing the three contrast media at the pulmonary trunk (p = 0.3198) and at the ascending aorta (p = 0.0840). Image quality (p = 0.0176) and discomfort during injection (p = 0.7034) were comparable for all groups. General discomfort after injection of contrast media with 300 mg iodine/ml was statistically significant higher compared to 370 mg iodine/ml (p = 0.00019). Given identical iodine delivery rates of 1.3 g/s and iodine loads of 33 g, contrast media with concentrations of 300, 370 and 400 mg iodine/ml do not result in different intravascular enhancement in chest-CT.
    European Radiology 12/2008; 18(12):2826-32. DOI:10.1007/s00330-008-1080-0 · 4.34 Impact Factor
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    ABSTRACT: PURPOSE The exploitation of radiation for medical benefits has increased significantly in the last years, especially with the use of X-Rays in Computed Tomography (CT). The potential effects of exposure to low doses of radiation are still poorly understood. The aim of the study was to evaluate the biological effects induced by radiation based on CT scans and a potential radiation dose enhancement caused by iodinated contrast media (CM) due to the photoelectric effect. METHOD AND MATERIALS Human blood was collected and immediately irradiated using a 64-slice-scanner (CT Siemens Sensation 64, Erlangen) after adding 0 (control) 5 and 50 mg Iodine/ ml blood Iotrolan 300 (ISOVIST® Bayer Schering Pharma, Berlin), respectively. CT Tube settings were 120 kV and 150 mAs using a rotation time of 1s. Radiation-doses were determined using a UNIDOS-dosimeter and a ionizationchamber. Blood-samples were placed in a tissue equivalent body phantom to achieve realistic scattering conditions. To allow γ-H2AX foci formation, samples were incubated for 45 min. Lymphocytes were isolated, stained for γ-H2AX and analyzed by confocal microscopy and flow cytometry. RESULTS For a clinical relevant Iodine concentration (5mg Iodine/ml blood) and a clinical relevant radiation dose (25, 50 and 100 mGy) contrast media did not cause an increase in γ- H2AX foci number compared to the control. An increase in γ-H2AX foci number, caused by contrast media could be detected by confocal microscopy at 100 mGy for 50 mg Iodine/ml and at 1000 mGy for 5 mg Iodine/ml blood. FACS analysis could only detect this dose enhancement at 1000 mGy and 50 mg Iodine/ml blood. CONCLUSION No relevant biological dose effects caused by contrast medium enhancement could be detected for CT at clinically relevant radiation doses and iodine concentrations. CLINICAL RELEVANCE/APPLICATION Ionizing radiation can lead to a variety of deleterious effects in humans, most importantly to the induction of cancer.
    Radiological Society of North America 2008 Scientific Assembly and Annual Meeting; 11/2008
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    ABSTRACT: To evaluate the influence of different types of iodinated contrast media on the assessment of myocardial viability, acute myocardial infarction (MI) was surgically induced in six rabbits. Over a period of 45 min, contrast-enhanced cardiac MDCT (64 x 0.6 mm, 80 kV, 680 mAs(eff.)) was repeatedly performed using a contrast medium dose of 600 mg iodine/kg body weight. Animals received randomized iopromide 300 and iodixanol 320, respectively. Attenuation values of healthy and infarcted myocardium were measured. The size of MI was computed and compared with nitroblue tetrazolium (NBT)-stained specimen. The highest attenuation differences between infarcted and healthy myocardium occurred during the arterial phase with 140.0+/-3.5 HU and 141.0+/-2.2 HU for iopromide and iodixanol, respectively. For iodixanol the highest attenuation difference on delayed contrast-enhanced images was achieved 3 min post injection (73.5 HU). A slightly higher attenuation difference was observed for iopromide 6 min after contrast medium injection (82.2 HU), although not statistically significant (p=0.6437). Mean infarct volume as measured by NBT staining was 33.5%+/-13.6%. There was an excellent agreement of infarct sizes among NBT-, iopromide- and iodixanol-enhanced MDCT with concordance-correlation coefficients ranging from rho(c)=0.9928-0.9982. Iopromide and iodixanol both allow a reliable assessment of MI with delayed contrast-enhanced MDCT.
    European Radiology 09/2008; 19(2):290-7. DOI:10.1007/s00330-008-1150-3 · 4.34 Impact Factor
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    ABSTRACT: To compare the impact of iodine concentration using two different contrast materials (CM) at standardized iodine delivery rate (IDR) and overall iodine load in 16-multidetector-row-CT-angiography (MDCTA) of the pulmonary arteries of 192 patients with known or suspected pulmonary embolism. One hundred three patients (group A) received 148 ml of a CM containing 300 mg iodine/ml (Ultravist 300, BayerScheringPharma) at a flow rate of 4.9 ml/s. Eighty-nine patients (group B) received 120 ml of a CM with a concentration of 370 mg iodine/ml (Ultravist 370) at a flow rate of 4.0 ml/s, resulting in a standardized IDR (approximately 1.5 gI/s) and the same overall amount of iodine (44.4 g). Both CM injections were followed by a saline chaser. Mean density values were determined in the pulmonary trunk, the ascending and the descending aorta, respectively. Applying repeated-measures ANOVA, no statistically significant differences between both MDCTA protocols were found (p = 0.5790): the mean density in the pulmonary trunk was 355 +/- 116 Hounsfield Units (group A) and 358 +/- 115 (group B). The corresponding values for the ascending and descending aorta were 295 +/- 79 (group A) and 284 +/- 65 (group B) as well as 272 +/- 71 and 262 +/- 70. In conclusion, the use of standardized IDR and overall iodine load provides comparable intravascular CM density in pulmonary 16-MDCTA for delivering contrast materials with different iodine concentrations.
    European Radiology 09/2008; 18(8):1690-5. DOI:10.1007/s00330-008-0942-9 · 4.34 Impact Factor
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    ABSTRACT: The purpose of this study was an intraindividual comparison of the degrees of MDCT contrast enhancement achieved with agents containing 300 and 370 mg I/mL. Seventy-five patients underwent baseline and follow-up MDCT of the chest and abdomen with contrast media containing a high concentration of iodine (iopromide 370 mg I/mL) and standard iodine concentration (iopromide 300 mg I/mL). The total iodine load (37 g) and the iodine delivery rate (1.29 g/s) were identical for the two protocols. Contrast enhancement in the chest (right and left ventricles, pulmonary trunk, descending aorta) and the abdomen (aorta, inferior vena cava, portal vein, and liver) was determined. Results were compared by use of paired Student's t tests, and p was adjusted with Bonferroni correction for multiple comparisons (p <or= 0.0056). Contrast enhancement was significantly higher for the 300 mg I/mL protocol than for the 370 mg I/mL protocol at all anatomic sites in the chest except the left ventricle (right ventricle, 359 +/- 100 H vs 320 +/- 102 H, p = 0.003; pulmonary trunk, 334 +/- 96 H vs 303 +/- 89 H, p = 0.003; left ventricle, 310 +/- 54 H vs 300 +/- 51 H, p = 0.036; descending aorta, 300 +/- 63 H vs 277 +/- 57 H, p = 0.0002). No statistically significant differences were found in the abdomen (all p > 0.0056). Given equivalent iodine load and delivery rate, the use of 300 mg I/mL contrast medium results in better contrast enhancement than use of 370 mg I/mL contrast medium in CT of the chest. For the portal venous phase of CT of the abdomen, there was no significant difference in contrast enhancement for the two concentrations of iodine.
    American Journal of Roentgenology 07/2008; 191(1):145-50. DOI:10.2214/AJR.07.3176 · 2.74 Impact Factor

Publication Stats

296 Citations
94.70 Total Impact Points


  • 2007–2012
    • Bayer HealthCare
      Leverkusen, North Rhine-Westphalia, Germany
  • 2010
    • RWTH Aachen University
      • Department of Diagnostic and Interventional Radiology
      Aachen, North Rhine-Westphalia, Germany
  • 2009
    • University Hospital RWTH Aachen
      • Department of Neurology
      Aachen, North Rhine-Westphalia, Germany