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ABSTRACT: Manganese is one of the most abundant metals on earth and is found as a component of more than 100 different minerals. Besides being an essential trace element in relation to the metabolic processes in the body, manganese is also a paramagnetic metal that possesses similar characteristics to gadolinium with regards to T1-weighted (T1-w) magnetic resonance imaging (MRI). Manganese, in the form of manganese (II) chloride tetrahydrate, is the active substance in a new targeted oral contrast agent, currently known as CMC-001, indicated for hepatobiliary MRI. Under physiological circumstances manganese is poorly absorbed from the intestine after oral intake, but by the use of specific absorption promoters, L-alanine and vitamin D(3), it is possible to obtain a sufficiently high concentration in the liver in order to achieve a significant signal enhancing effect. In the liver manganese is exposed to a very high first-pass effect, up to 98%, which prevents the metal from reaching the systemic circulation, thereby reducing the number of systemic side-effects. Manganese is one of the least toxic trace elements, and due to its favorable safety profile it may be an attractive alternative to gadolinium-based contrast agents for patients undergoing an MRI evaluation for liver metastases in the future. In this review the basic pharmacological and pharmaceutical aspects of this new targeted oral hepatobiliary specific contrast agent will be discussed.
Acta Radiologica 07/2012; 53(7):707-13. · 1.37 Impact Factor
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ABSTRACT: OBJECTIVES: To compare 0.15 mmol/kg gadobutrol for late gadolinium enhancement (LGE) imaging of chronic myocardial infarction with a relaxivity-adjusted dose of gadoterate meglumine (Gd-DOTA). METHODS: Seventeen patients with suspected chronic myocardial infarction underwent LGE imaging at 1.5 T, acquiring an inversion-recovery-prepared gradient echo sequence 15 min after contrast agent administration. Each patient underwent LGE imaging twice, once after administration of 0.15 mmol/kg gadobutrol (r1 = 5.2 l mmol(-1) s(-1)) and after 0.22 mmol/kg Gd-DOTA (r1 = 3.6 l mmol(-1) s(-1)). Two readers independently determined infarct size and contrast-to-noise ratios of infarcted myocardium to remote myocardium (CNR(remote)) and to the left ventricular lumen (CNR(lumen)). RESULTS: LGE was present in 14 patients. Infarct sizes determined after administration of gadobutrol [23.4 ml; 95 % CI (14.4; 32.5)] and Gd-DOTA [22.1 ml; 95 % CI (13.0; 31.1)] were not statistically different (P = 0.22). The CNR(remote) of LGE in infarcted myocardium on gadobutrol- and Gd-DOTA-enhanced images was 44.1 [95 % CI (31.0; 57.1)] and 45.2 [95 % CI (32.2; 58.3)], respectively (P = 0.73). CNR(lumen) was significantly higher on gadobutrol-enhanced LGE images [12.7; 95 % CI (2.5; 23.0) versus 6.8; 95 % CI (-3.5; 17.0); P = 0.02]. CONCLUSION: At relaxivity-adjusted doses, gadobutrol and Gd-DOTA yielded similar infarct sizes with superior contrast between infarcted myocardium and left ventricular lumen on gadobutrol-enhanced images. KEY POINTS: • Contrast-enhanced magnetic resonance imaging is increasingly used to assess the myocardium • Macrocyclic Gd-based contrast agents are considered to be safer than linear agents • Myocardial infarction MRI can be performed using either gadobutrol or gadoterate meglumine • Contrast between infarcted myocardium and the left ventricular lumen was greater using gadobutrol • The minimum macrocyclic dose needed for reliable LGE imaging requires further evaluation.
European Radiology 07/2012; · 3.22 Impact Factor
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Sebastian Schattke, Moritz Wagner,
Robert Hättasch,
Sabrina Schroeckh,
Tahir Durmus,
Ingolf Schimke,
Wasiem Sanad,
Sebastian Spethmann,
Jürgen Scharhag,
Alexander Huppertz,
Gert Baumann,
Adrian C Borges,
Fabian Knebel
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ABSTRACT: Our study compares new single beat 3D echocardiography (sb3DE) to cardiovascular magnetic resonance imaging (CMR) for the measurement of right ventricular (RV) dimension and function immediately after a 30 km run. This is to validate sb3DE against the "gold standard" CMR and to bring new insights into acute changes of RV dimension and function after endurance exercise.
21 non-elite male marathon runners were examined by sb3DE (Siemens ACUSON SC2000, matrix transducer 4Z1c, volume rates 10-29/s), CMR (Siemens Magnetom Avanto, 1,5 Tesla) and blood tests before and immediately after each athlete ran 30 km. The runners were not allowed to rehydrate after the race. The order of sb3DE and CMR examination was randomized.
Sb3DE for the acquisition of RV dimension and function was feasible in all subjects. The decrease in mean body weight and the significant increase in hematocrit indicated dehydration. RV dimensions measured by CMR were consistently larger than measured by sb3DE.Neither sb3DE nor CMR showed a significant difference in the RV ejection fraction before and after exercise. CMR demonstrated a significant decrease in RV dimensions. Measured by sb3DE, this decrease of RV volumes was not significant.
First, both methods agree well in the acquisition of systolic RV function. The dimensions of the RV measured by CMR are larger than measured by sb3DE. After exercise, the RV volumes decrease significantly when measured by CMR compared to baseline.Second, endurance exercise seems not to induce acute RV dysfunction in athletes without rehydration.
Cardiovascular Ultrasound 02/2012; 10:6. · 1.26 Impact Factor
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ABSTRACT: To compare 0.15 mmol/kg gadobutrol with 0.20 mmol/kg gadopentetate dimeglumine with regard to late gadolinium enhancement (LGE) of infarcted myocardium at magnetic resonance (MR) imaging.
Twenty patients with history of chronic myocardial infarction underwent 2 cardiac MR examinations at 1.5 Tesla. For the evaluation of myocardial infarction, late gadolinium enhancement (LGE) imaging was performed with an inversion recovery-prepared gradient-echo sequence 15 minutes after administration of either gadobutrol (r1 = 5.2 mmol(-1)s(-1)) or gadopentetate dimeglumine (r1 = 4.1 mmol(-1)s(-1)). The dose of the contrast agents was adjusted based on the relaxivity of both contrast agents. Hence, gadobutrol and gadopentetate dimeglumine were administered at 0.15 mmol/kg and 0.20 mmol/kg, respectively. Contrast-to-noise ratios (CNR) between infarcted myocardium and remote myocardium (CNR remote) and between infarcted myocardium and left ventricular lumen (CNR lumen) were assessed by 2 independent readers. Additionally, infarct size was assessed semiautomatically by using a threshold of 5 standard deviations above the mean signal intensity of remote myocardium.
Subendocardial or transmural LGE was present in 16 of 20 (80%) patients. The optimal inversion time for LGE imaging did not differ significantly between gadobutrol and gadopentetate dimeglumine (275 ± 21 milliseconds [range, 240-320 milliseconds] and 282 ± 23 milliseconds [range, 240-330 milliseconds], respectively; P = 0.32). The CNR remote after administration of gadobutrol (40.0 ± 4.6; 95% confidence interval [CI]: 30.3; 49.7) and gadopentetate dimeglumine (40.6 ± 4.6; 95% CI: 30.9; 50.3) did not show significant differences (P = 0.90), whereas gadobutrol yielded a significantly higher CNR lumen (6.2 ± 3.6; 95% CI: -1.5; 13.9) compared with gadopentetate dimeglumine (0.8 ± 3.6; 95% CI: -6.9; 8.5). Infarct size after administration of gadobutrol (23.7 ± 4.7 mL; 95% CI: 13.6; 33.7) and gadopentetate dimeglumine (23.7 ± 4.7 mL;95% CI: 13.7; 33.8) was not statistically different (P = 0.94). There was an excellent correlation between gadobutrol- and gadopentetate dimeglumine-enhanced assessment of infarct size (Spearman r = 0.99 and r = 0.97 for reader 1 and 2, respectively).
This pilot study shows that 0.15 mmol/kg gadobutrol is an effective contrast agent for LGE imaging with better delineation of infarcted myocardium from left ventricular lumen than 0.20 mmol/kg gadopentetate dimeglumine.
Investigative radiology 12/2011; 47(3):183-8. · 4.85 Impact Factor
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ABSTRACT: To evaluate very small superparamagnetic iron oxide particles (VSOP-C184) as blood-pool contrast agent for coronary MR angiography (CMRA) in humans.
Six healthy volunteers and 14 patients with suspected coronary artery disease underwent CMRA after administration of VSOP-C184 at the following doses: 20 μmol Fe/kg (4 patients), 40 μmol Fe/kg (5 patients), 45 μmol Fe/kg (6 healthy volunteers), and 60 μmol Fe/kg (5 patients). In healthy volunteers, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and vessel edge definition (VED) of contrast-enhanced CMRA were compared with non-contrast-enhanced CMRA. In patients, a per-segment intention-to-diagnose evaluation of contrast-enhanced CMRA for detection of significant coronary stenosis (≥50%) was performed.
Three healthy volunteers (45 μmol Fe/kg VSOP-C184) and two patients (60 μmol Fe/kg VSOP-C184) had adverse events of mild or moderate intensity. VSOP-C184 significantly increased CNR (15.1 ± 4.6 versus 6.9 ± 1.9; P = 0.010), SNR (21.7 ± 5.3 versus 15.4 ± 1.6; P = 0.048), and VED (2.3 ± 0.6 versus 1.2 ± 0.2; P < 0.001) compared with non-contrast-enhanced CMRA. In patients, contrast-enhanced CMRA yielded sensitivity, specificity, and diagnostic accuracy for detection of significant coronary stenosis of 86.7%, 71.0%, 73.1%, respectively.
CMRA using VSOP-C184 was feasible and yielded moderate diagnostic accuracy for detection of significant coronary stenosis within this proof-of-concept setting.
Journal of Magnetic Resonance Imaging 07/2011; 34(4):816-23. · 2.70 Impact Factor
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ABSTRACT: To review the tolerability and diagnostic effectiveness of gadoteric acid under daily practice conditions in the general population and at-risk patients.
A total of 84,621 patients (45.4% men, 54.6% women, mean age 52.0 ± 16.9 years) were studied in 129 German centers. Patients underwent contrast-enhanced magnetic resonance imaging (MRI) using gadoteric acid (Gd-DOTA, Dotarem(®), Guerbet, Roissy CdG, France) as IV contrast medium (mean volume, 16.4 ml). 22.9% of the patients had at least one risk factor (e.g., allergies, previous allergic reaction to a contrast medium, and renal impairment). 554 patients received pretreatment before contrast medium administration (0.7%). Adverse events were documented and image quality was assessed.
A diagnosis was possible in 99.7% of all cases. Image quality was rated good or excellent in 97.1%. Adverse events (e.g., nausea, vomiting, and urticaria) were observed in 0.34% of the examinations and were mostly rated as minor. There were 8 patients with serious adverse events. The adverse event rate was significantly higher in patients with a history of allergies (0.62%; p<0.001) and in patients with a previous allergic reaction to contrast medium (1.23%; p<0.001). There was no elevated incidence of adverse events in patients with renal impairment.
Gadoteric acid is a well-tolerated MRI contrast medium in patients with and without risk factors that is associated with a low rate of adverse events and good or excellent image quality in most patients.
European journal of radiology 05/2011; 81(5):885-90. · 2.65 Impact Factor
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Moritz Wagner,
Roberta Rösler,
Alexander Lembcke,
Craig Butler,
Marc Dewey,
Michael Laule,
Alexander Huppertz,
Carsten Schwenke,
Carsten Warmuth,
Matthias Rief,
Bernd Hamm,
Matthias Taupitz
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ABSTRACT: To evaluate the impact of the blood-pool contrast agent gadofosveset trisodium on diagnostic accuracy of whole-heart coronary magnetic resonance angiography (CMRA) at 1.5 Tesla.
Thirty consecutive patients with suspected coronary artery disease underwent free-breathing whole-heart CMRA at 1.5 Tesla. CMRA was performed with a T2-prepared steady-state free precession sequence (unenhanced CMRA) and an inversion-recovery-prepared steady-state free precession sequence after administration of gadofosveset trisodium (contrast-enhanced CMRA). Two readers independently performed a per-segment evaluation of CMRA (8 proximal and mid coronary segments) for detection of significant stenosis (≥50%) using invasive coronary angiography as reference. Disagreement was settled by consensus reading and interobserver variability was assessed using an unweighted kappa statistic.
Whole-heart CMRA was successfully performed in 27 patients. The percentage of assessable segments was significantly lower on unenhanced CMRA compared with contrast-enhanced CMRA (Reader 1: 79% [170/216] vs. 89% [192/216], respectively; Reader 2: 73% [157/216] vs. 87% [188/216], respectively; P < 0.001). Intention-to-diagnose analysis of the consensus reading yielded sensitivity, specificity, and diagnostic accuracy of unenhanced versus contrast-enhanced CMRA as follows: 73.1% versus 73.1% (P = 1.0), 68.3% versus 80.2% (P = 0.002), and 68.9% versus 79.3% (P = 0.004), respectively. The kappa value for interobserver agreement was 0.61 (95% confidence interval = 0.50-0.72) for unenhanced CMRA and 0.72 (95% confidence interval = 0.62-0.82) for contrast-enhanced CMRA.
The blood-pool contrast agent gadofosveset trisodium increased the number of assessable coronary segments on whole-heart CMRA in comparison to unenhanced whole-heart CMRA. The impact of gadofosveset trisodium on diagnostic accuracy, however, was only minor.
Investigative radiology 03/2011; 46(3):152-9. · 4.85 Impact Factor
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ABSTRACT: To evaluate if erythromycin compromises liver-specific enhancement of gadoxetic acid; both compounds competing in organic anion transporting peptides (OATP) -mediated hepatocytic uptake.
The study was approved by institutional review board. Twelve healthy subjects (nine men, three woman; mean age, 38.7 years) were examined twice by MR imaging with prior administration of NaCl solution (placebo) or 1000 mg of erythromycin following a randomized sequence. Gadoxetic acid (0.025 mmol/kg body weight) was administered 15 min after the end of infusions. Pre- and 20 min postcontrast two-dimensional gradient-recalled-echo sequences were acquired. Relative enhancements of liver parenchyma and ratio of means were calculated from signal intensity measurements. Plasma levels of gadoxetic acid and erythromycin were determined and given in geometric means and coefficients of variation (CV).
Concentration of erythromycin directly after end of infusion was 13.9 mg/L (CV 14.9%). Gadolinium plasma concentrations 5 min after gadoxetic acid administration were 138.7 μmol/L (CV 20.4%) after erythromycin infusion and 129.6 μmol/L (CV 22.8%) after placebo. Mean relative enhancements of liver parenchyma were 88.1 (SD 24.9%) after erythromycin infusion and 92.6 (SD 17.9%) after placebo. Ratio of relative enhancements was 0.951 (95% confidence interval, 0.833; 1.061; statistically not significant).
Coadministration of erythromycin has no effect on gadoxetic acid enhanced liver MR imaging.
Journal of Magnetic Resonance Imaging 02/2011; 33(2):409-16. · 2.70 Impact Factor
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Alexander Huppertz MD,
Josy Breuer MD,
Lueder M. Fels PhD,
Marcus Schultze-Mosgau PhD,
Gabriele Sutter PhD,
Stefan Klein PhD,
Bernd Frericks MD,
Bernd Hamm MD,
Moritz Wagner MD,
Alexander Huppertz,
Josy Breuer,
Lueder M. Fels,
Marcus Schultze‐Mosgau,
Gabriele Sutter,
Stefan Klein,
Bernd Frericks,
Bernd Hamm, Moritz Wagner
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ABSTRACT: PurposeTo evaluate if erythromycin compromises liver-specific enhancement of gadoxetic acid; both compounds competing in organic anion transporting peptides (OATP) -mediated hepatocytic uptake.Materials and Methods
The study was approved by institutional review board. Twelve healthy subjects (nine men, three woman; mean age, 38.7 years) were examined twice by MR imaging with prior administration of NaCl solution (placebo) or 1000 mg of erythromycin following a randomized sequence. Gadoxetic acid (0.025 mmol/kg body weight) was administered 15 min after the end of infusions. Pre- and 20 min postcontrast two-dimensional gradient-recalled-echo sequences were acquired. Relative enhancements of liver parenchyma and ratio of means were calculated from signal intensity measurements. Plasma levels of gadoxetic acid and erythromycin were determined and given in geometric means and coefficients of variation (CV).ResultsConcentration of erythromycin directly after end of infusion was 13.9 mg/L (CV 14.9%). Gadolinium plasma concentrations 5 min after gadoxetic acid administration were 138.7 μmol/L (CV 20.4%) after erythromycin infusion and 129.6 μmol/L (CV 22.8%) after placebo. Mean relative enhancements of liver parenchyma were 88.1 (SD 24.9%) after erythromycin infusion and 92.6 (SD 17.9%) after placebo. Ratio of relative enhancements was 0.951 (95% confidence interval, 0.833; 1.061; statistically not significant).Conclusion
Coadministration of erythromycin has no effect on gadoxetic acid enhanced liver MR imaging. J. Magn. Reson. Imaging 2011;33:409–416. © 2011 Wiley-Liss, Inc.
Journal of Magnetic Resonance Imaging 01/2011; 33(2):409 - 416. · 2.70 Impact Factor
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Judith Enders,
Elke Zimmermann,
Matthias Rief,
Peter Martus,
Randolf Klingebiel,
Patrick Asbach,
Christian Klessen,
Gerd Diederichs, Moritz Wagner,
Ulf Teichgräber,
Thomas Bengner,
Bernd Hamm,
Marc Dewey
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ABSTRACT: Claustrophobia is a common problem precluding MR imaging. The purpose of the present study was to assess whether a short-bore or an open magnetic resonance (MR) scanner is superior in alleviating claustrophobia.
Institutional review board approval and patient informed consent were obtained to compare short-bore versus open MR. From June 2008 to August 2009, 174 patients (139 women; mean age = 53.1 [SD 12.8]) with an overall mean score of 2.4 (SD 0.7, range 0 to 4) on the Claustrophobia Questionnaire (CLQ) and a clinical indication for imaging, were randomly assigned to receive evaluation by open or by short-bore MR. The primary outcomes were incomplete MR examinations due to a claustrophobic event. Follow-up was conducted 7 months after MR imaging. The primary analysis was performed according to the intention-to-treat strategy.
With 33 claustrophobic events in the short-bore group (39% [95% confidence interval [CI] 28% to 50%) versus 23 in the open scanner group (26% [95% CI 18% to 37%]; P = 0.08) the difference was not significant. Patients with an event were in the examination room for 3.8 min (SD 4.4) in the short-bore and for 8.5 min (SD 7) in the open group (P = 0.004). This was due to an earlier occurrence of events in the short-bore group. The CLQ suffocation subscale was significantly associated with the occurrence of claustrophobic events (P = 0.003). New findings that explained symptoms were found in 69% of MR examinations and led to changes in medical treatment in 47% and surgery in 10% of patients. After 7 months, perceived claustrophobia increased in 32% of patients with events versus in only 11% of patients without events (P = 0.004).
Even recent MR cannot prevent claustrophobia suggesting that further developments to create a more patient-centered MR scanner environment are needed.
ClinicalTrials.gov NCT00715806.
PLoS ONE 01/2011; 6(8):e23494. · 4.09 Impact Factor
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ABSTRACT: In TNM staging of rectal cancer by MRI, unspecific extracellular contrast agent Gd-DTPA is established for extrahepatic and vascular enhancement whereas liver-specific gadoxetic acid has proven high accurate detection of liver metastasis.
To compare intraindividually the qualification and quantification of enhancement in liver parenchyma, abdominal, pulmonary, and pelvic vessels between gadoxetic acid and Gd-DTPA.
Sixteen patients with histologically proven rectal carcinoma (mean age 62.9 years) were imaged twice by MRI. For pretherapeutic staging 10 mL gadoxetic acid (mean dose 0.032 mmol Gd/kg body weight) and for restaging after neoadjuvant therapy Gd-DTPA (0.1 mmol Gd/kg body weight) were administered. The liver was acquired in arterial-dominant and portal venous phases, the thorax and pelvis were depicted in venous phases using three-dimensional T1-weighted sequences. Contrast enhancement was rated by two independent readers and compared by means of multinomial regression analysis using generalized estimating equations. Signal-to-noise ratios were compared by two-sided paired t-tests.
Overall contrast enhancement was rated sufficient for diagnosis in all examinations and both contrast agents. Vascular enhancement was rated comparable with exception of the aorta, the peripheral intrahepatic veins, and the central lung vessels (p = 0.0182, p = 0.0053, p = 0.0083, in favor of Gd-DTPA). Quantitative evaluation revealed no statistically significant differences in parenchymal and vascular signal-to-noise ratios with exception of the aorta, and the central pulmonary artery (67.4 vs. 89.3; p = 0.0421, 44.5 vs. 59.5; p = 0.0446 respectively, in favor of Gd-DTPA).
The contrast enhancement after gadoxetic acid is comparable to Gd-DTPA and appears suitable for comprehensive TNM-staging by combining high accurate liver-specific phases with efficacious vascular enhancement in the different anatomic regions.
Acta Radiologica 10/2010; 51(8):842-50. · 1.37 Impact Factor
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Antje Voigt,
Thomas Elgeti,
Tahir Durmus,
Merve Ece Idiz,
Craig Butler,
Mark Beling,
Rene Schilling,
Karin Klingel,
Reinhard Kandolf,
Karl Stangl,
Matthias Taupitz,
Dietmar Kivelitz, Moritz Wagner
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ABSTRACT: To assess active myocardial inflammation by cardiovascular magnetic resonance (CMR) and endomyocardial biopsy (EMB) amongst adult patients with dilated cardiomyopathy (DCM).
We evaluated 23 adults with chronic DCM, who had successfully undergone both CMR and EMB within 3.5 ± 2.6 days. EMB was considered the gold standard. CMR assessment of myocardial inflammation used the following parameters as recommended by the recently published "Lake Louise Criteria": global myocardial oedema, global relative enhancement (RE), and late gadolinium enhancement (LGE). According to "Lake Louise Criteria", myocardial inflammation was diagnosed if two or more of the three above-mentioned parameters were positive.
Myocardial inflammation was confirmed by immunohistology in 12 patients (52.2%). Sensitivity, specificity, and diagnostic accuracy of CMR to detect immunohistologically confirmed myocardial inflammation were 75.0%, 72.7%, and 73.9%, respectively. Sensitivity, specificity, and diagnostic accuracy of the individual CMR parameters to detect myocardial inflammation were as follows: global myocardial oedema, 91.7%, 81.8%, and 87.0%, respectively; global RE, 58.3%, 63.6%, and 60.9%, respectively; LGE, 58.3%, 45.4%, and 52.2%, respectively.
Global myocardial oedema was identified as a promising CMR parameter for assessment of myocardial inflammation in patients with DCM. In these patients, global myocardial oedema yielded superior diagnostic performance compared to "Lake Louise Criteria".
European Radiology 10/2010; 21(5):925-35. · 3.22 Impact Factor
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ABSTRACT: To document immediate and short-term changes in uterine perfusion after uterine artery embolization (UAE).
Fifteen patients (median age, 42 years) underwent UAE with tris-acryl gelatin microspheres and a limited embolization protocol. Contrast-enhanced magnetic resonance imaging was performed before therapy and 1 hour (immediate), 48-72 hours (subacute), and a median of 5 months (short-term follow-up) after UAE to determine uterine and leiomyoma perfusion. Leiomyomas with a minimum diameter of 10 mm were included. Changes in regional (ie, fundus/body/cervix), zonal (ie, endometrium/inner/middle and outer myometrial layer), and leiomyoma perfusion were documented.
UAE was technically successful in all patients. Immediate contrast-enhanced MR imaging revealed ischemia of the uterine body and fundus. The endometrium and inner myometrial layer was involved in all 15 patients; the middle layer was also involved in 13. Ischemic defects were seen in the outer layer in one patient but never in the cervix. Subacute follow-up showed reperfusion of the myometrium in 73% of patients. Ischemic defects occurred in the endometrial and junctional zone in four patients and in the middle zone in one. Five-month follow-up showed perfusion of all uterine layers in all patients. Ten patients had complete infarction of all leiomyomas; five presented with 11 partially perfused leiomyomas.
Limited bilateral UAE leads to transient uterine ischemia, particularly involving the endometrium and inner and middle zone of the myometrium of the uterine body and fundus. The cervix and subserosal layer are spared. Complete reperfusion of myometrial tissue is observed within 48-72 hours in most cases, whereas ischemic leiomyomas undergo irreversible infarction.
Journal of vascular and interventional radiology: JVIR 09/2010; 21(9):1347-53. · 1.81 Impact Factor
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ABSTRACT: Recently, an oral contrast agent (CMC-001, CMC Contrast, Lund, Sweden) containing manganese chloride tetrahydrate (MnCl2) as active substance has been introduced for liver magnetic resonance imaging (MRI). The aim of this study was to evaluate the time course and dose response of liver signal intensity (SI) enhancement and liver-lesion contrast (LLC) after administration of 2 doses of CMC-001 corresponding to 0.8 g MnCl2 and 1.6 g MnCl2.
A total of 20 patients with liver metastases diagnosed by computed tomography were included in this prospective study. Patients were randomly assigned to receive either 0.8 g MnCl2 (n = 11) or 1.6 g MnCl2 (n = 9). MRI was performed precontrast (0 hour) and at 1, 2, 3, and 6 hours after contrast agent administration using a breath-hold T1-weighted gradient echo sequence (GRE). For quantitative analysis, SI was measured in regions of interest in the liver and in representative liver metastases. Liver SI enhancement and LLC were calculated. Area under the curve analysis was performed for liver SI enhancement and LLC in both dose groups. The dose groups were compared with a Wilcoxon rank-sum test for independent samples. Tests for pairwise differences between the time points were performed with paired Wilcoxon signed-rank tests.
Area under the curve analysis revealed no statistical significant differences for liver SI enhancement and LLC between the 0.8 and 1.6 g MnCl2 dose group (P = 1.00 and P = 0.94, respectively). Liver parenchyma showed significant SI enhancement until 3 hours after contrast agent administration (median of pooled data from both dose groups: 1 hour, 24.7%; 2 hours, 37.2%; 3 hours, 54.9%; 6 hours, 47.3%). LLC significantly increased until 2 hours after contrast agent administration (median of pooled data from both dose groups: 0 hour, 0.19; 1 hour, 0.29; 2 hours, 0.36; 3 hours, 0.37; 6 hours, 0.36). Liver SI enhancement and LLC showed no significant differences between 3 hours and 6 hours after contrast agent administration (P = 0.75 and P = 0.25, respectively). Mild adverse events occurred in 6 patients (30%) after contrast agent administration.
CMC-001 at doses corresponding to 0.8 and 1.6 g MnCl2 offers robust liver SI enhancement with a diagnostic time window for liver MRI between 2 and 6 hours after oral administration.
Investigative radiology 09/2010; 45(9):565-71. · 4.85 Impact Factor
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Moritz Wagner,
Craig Butler,
Matthias Rief,
Mark Beling,
Tahir Durmus,
Alexander Huppertz,
Antje Voigt,
Gert Baumann,
Bernd Hamm,
Alexander Lembcke,
Thomas Vogtmann
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ABSTRACT: To compare non-gated vs. electrocardiogram (ECG)-gated 64-detector-row computed tomography (MDCT) of the left atrium (LA) for integrated electroanatomic mapping (EAM) in patients with paroxysmal atrial fibrillation (AF).
Twenty-nine consecutive patients with paroxysmal AF underwent MDCT prior to pulmonary vein isolation (PVI). All patients were in sinus rhythm both during CT imaging and PVI. Multi-detector-row computed tomography was performed in 15 patients without ECG-gating (non-gated MDCT) and in 14 patients with retrospective ECG-gating (ECG-gated MDCT). Image quality of LA reconstructions from MDCT was rated on a five-point scale (from 1 = excellent to 5 = segmentation failed). Registration error between LA geometry obtained from EAM and MDCT was calculated as the mean distance between EAM points and MDCT surface. In all patients, LA was successfully segmented from MDCT data. The segmentation process took 2:31 +/- 0:54 min for non-gated MDCT and 2:36 +/- 0:47 min for ECG-gated MDCT (P = 0.8). Image quality scores of LA reconstructions from non-gated and ECG-gated MDCT were 1.3 +/- 0.6 and 1.4 +/- 0.7, respectively (P = 0.76). There was no significant difference in the registration error between non-gated and ECG-gated MDCT (1.8 +/- 0.2 vs. 1.9 +/- 0.3 mm, respectively; P = 0.6). The radiation dose of non-gated MDCT was significantly lower compared with ECG-gated MDCT (4.6 +/- 1.4 vs. 13.4 +/- 3.6 mSv, respectively; P < 0.001).
Non-gated MDCT depicts LA with appropriate image quality for integrated EAM, while exposing patients to substantially lower radiation dose compared with ECG-gated MDCT.
Europace 08/2010; 12(8):1090-7. · 1.98 Impact Factor
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ABSTRACT: We sought to determine the comparability of multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) for measuring the aortic valve orifice area (AVA) and grading aortic valve stenosis.
Twenty-seven individuals, among them 18 patients with valvular stenosis, underwent AVA planimetry by both MSCT and MRI. In the subset of patients with valvular stenosis, AVA was also calculated from transthoracic Doppler echocardiography (TTE) using the continuity equation.
There was excellent correlation between MSCT and MRI (r = 0.99) and limits of agreement were in an acceptable range (± 0.42 cm(2)) although MSCT yielded a slightly smaller mean AVA than MRI (1.57 ± 0.83 cm(2) vs. 1.67 ± 0.98 cm(2), p < 0.05). However, in the subset of patients with valvular stenosis, the mean AVA was not different between MSCT and MRI (1.05 ± 0.30 cm(2) vs. 1.04 ± 0.39 cm(2); p > 0.05). The mean AVAs on both MSCT and MRI were systematically larger than on TTE (0.88 ± 0.28 cm(2), p < 0.001 each). Using an AVA of 1.0 cm(2) on TTE as reference, the best threshold for detecting severe-to-critical stenosis on MSCT and MRI was an AVA of 1.25 cm(2) and 1.30 cm(2), respectively, resulting in an accuracy of 96% each.
Our study specifies recent reports on the suitability of MSCT for quantifying AVA. The data presented here suggest that certain methodical discrepancies of AVA measurements exist between MSCT, MRI and TTE. However, MSCT and MRI have shown excellent correlation in AVA planimetry and similar accuracy in grading aortic valve stenosis.
European journal of radiology 09/2009; 77(3):426-35. · 2.65 Impact Factor
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Alexander Huppertz,
Hannes Kroll,
Christian Klessen,
Matthias Taupitz,
Ralph I Rückert,
Ralf-Juergen Schröder,
Thomas Albrecht,
Bernd Frericks,
Matthias Voth, Moritz Wagner,
Bernd Hamm,
Patrick Asbach
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ABSTRACT: To prospectively evaluate diagnostic accuracy of first pass and combined first pass and steady state high-spatial-resolution whole-body magnetic resonance (MR) angiography with a blood pool contrast agent for quantification of arterial stenosis in different vascular territories.
After Institutional Review Board approval and informed consent, 50 patients with known 50% or greater stenosis in at least one vascular territory; as shown by the standard-of-reference (14 digital subtraction angiographies, 4 computed tomographies, 32 ultrasound examinations), were included. The patients underwent MR angiography at 1.5 Tesla, using a standardized nonbody-weight-adapted i.v. bolus injection of 11 mL gadofosveset trisodium. First pass imaging with 4 different table positions in a whole-body MR scanner (MAGNETOM Avanto, Siemens Healthcare), using individual circulation time determined by a test bolus, was performed. Steady state imaging was performed using an isometric spatial resolution of 1.0 mm. Image quality was rated. Each vascular segment in MR angiography was evaluated by 2 independent and blinded reviewers and the stenosis degree was compared with the preferred standard-of-reference, using a 5-point scale. Differences between first pass and combined MR angiography were assessed with a 95% confidence interval (CI) by applying the adjusted modified chi(2) test. Changes in therapy based on the whole-body examination strategy were evaluated.
The number of nondiagnostic territories was 24 of 197 (12.2%) for first pass MR angiography and decreased to 3 of 197 (1.5%) after addition of steady state MR angiography. The diagnostic accuracy for quantification of arterial stenosis in combined MR angiography (94.7%; 95% CI: 92.4-97.1) was superior to first pass MR angiography (81.7%; 95% CI: 73.7-89.8; statistically significant). Patient management was changed in 12 of 49 patients, in 7 of 12 patients the change was applied to an additional lesion detected by the whole-body examination strategy.
The quantification and detection of arterial stenosis is improved by the steady state high-resolution gadofosveset trisodium-enhanced MR angiography. Additional lesions detected by whole-body examination strategy or differences in stenosis quantification may lead to changes in therapy.
Investigative radiology 06/2009; 44(7):422-32. · 4.85 Impact Factor
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ABSTRACT: To investigate the image quality and detection rate of focal liver lesions by comparing a T2-weighted breath-hold single-shot sequence and a T2-weighted high spatial resolution fast spin-echo sequence with respiratory triggering via unenhanced and superparamagnetic iron oxide (SPIO)-enhanced liver imaging.
The study was approved by the local ethical review board; informed consent was waived. Liver-lesion contrast was measured and a qualitative consensus evaluation of image quality and lesion detection was performed in 42 consecutive patients using a 1.5-T MR system.
The liver-lesion contrast was significantly higher (P<.05) for the respiratory-triggered sequence compared to the breath-hold sequence regarding unenhanced and SPIO-enhanced imaging. The respiratory-triggered sequences revealed significantly higher image quality scores as well as higher numbers of detected liver lesions compared to the breath-hold sequence on unenhanced and SPIO-enhanced imaging. The SPIO contrast did not significantly improve the number of detected lesions on the respective sequences (P>.05).
We find that respiratory-triggered fast spin-echo sequences produce a higher image quality and a more precise liver-lesion detection rate thereby justifying the increased acquisition time necessary for this method.
Magnetic Resonance Imaging 06/2009; 27(9):1223-9. · 1.99 Impact Factor
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Moritz Wagner,
Matthias Rief,
Patrick Asbach,
Thomas Vogtmann,
Alexander Huppertz,
Mark Beling,
Craig Butler,
Michael Laule,
Carsten Warmuth,
Matthias Taupitz,
Bernd Hamm,
Alexander Lembcke
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ABSTRACT: Imaging of the left atrium is regularly performed prior to pulmonary vein isolation. The aim of the study was to evaluate the feasibility of contrast-enhanced high-resolution magnetic resonance angiography (MRA) of the left atrium using the blood-pool contrast agent gadofosveset trisodium in comparison to noncontrast MRA.
Twenty consecutive patients were examined by free-breathing electrocardiogram-gated whole-heart MRA (reconstructed spatial resolution, 0.7mm x 0.6mm x 0.8mm) with a noncontrast T2-prepared steady state free precession sequence (T2-prep SSFP) and a gadofosveset trisodium-enhanced inversion-recovery SSFP sequence (CE IR-SSFP). Contrast-to-noise ratio (CNR) of blood in the left atrium was determined. Depiction of the left atrium was rated by two radiologists in consensus. A cardiologist segmented the MR data sets and rated depiction of the left atrium.
Five of 20 patients had irregular breathing patterns with navigator efficiency less than 35% and were excluded from evaluation. CNR was significantly higher for CE IR-SSFP compared with T2-prep SSFP (18.4+/-5.3 vs. 11.7+/-3.5, p<0.01). Depiction of the left atrium by T2-prep SSFP was rated as good in four patients, moderate in ten patients, and poor in one patient, whereas depiction of the left atrium by CE IR-SSFP was rated as excellent in nine patients, good in four patients, and moderate in two patients. CE IR-SSFP allowed for semiautomated segmentation of the left atrium in 15 patients, whereas T2-prep SSFP allowed for segmentation only in ten patients.
Gadofosveset trisodium-enhanced MRA of the left atrium is feasible with significantly improved image quality compared to noncontrast MRA.
European journal of radiology 05/2009; 75(2):166-72. · 2.65 Impact Factor
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ABSTRACT: The authors report study protocols and initial clinical experience in assessing patients with acute and chronic cerebrovascular disorders using the recently introduced technique of volume computed tomography (VCT).
Thirteen patients with presumptive cerebrovascular insufficiency underwent VCT using a 320-slice scanner (detector width, 160 mm), including time-resolved whole-brain perfusion and cerebral angiography (four-dimensional computed tomographic angiography [CTA] and computed tomographic perfusion [CTP]). Unenhanced cranial CT (cCT) and helical cervicocranial CT (three-dimensional CTA) were added according to clinical requirements. Study protocols are presented, and image quality, data management, and radiation exposure issues are discussed.
In 12 of 13 patients, the procedure was performed successfully on admission; in the other patient, the study was aborted for clinical reasons and repeated. Total scan time amounted to about 5 minutes, and data reconstruction times were up to 10 minutes. About 9000 primary images were generated, partially in the enhanced Digital Imaging and Communications in Medicine format, thus requiring new data postprocessing and management strategies. Image artifacts restricted the use of single-rotation cCT and incremental VCT (three-dimensional CTA). Overall exposure figures (computed tomographic dose index and dose-length product) were increased by 65% on average when three-dimensional CTA was added to volume cCT and four-dimensional CTA and CTP (5.0 mSv and 2178 mGy . cm, respectively).
Preliminary clinical experience indicates that whole-brain four-dimensional CTA and CTP is a robust technique that provides relevant clinical information with respect to whole-brain perfusion as well as cerebral hemodynamics. The exposure benefit of deriving time-resolved perfusion and vessel images from one source data set is compromised when adding three-dimensional CTA to the protocol. Other acquisition techniques specific to VCT, such as single-rotation cCT and incremental three-dimensional CTA, suffer from restrictions in terms of image quality at present.
Academic radiology 03/2009; 16(2):123-9. · 2.09 Impact Factor
