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Biomedical subjects

Jörg Barkhausen

Publications and source records attributed to Jörg Barkhausen.

At least 19 recordsLinked to original sources
PubMed2007

Clinical safety and diagnostic value of the gadolinium chelate gadoterate meglumine (Gd-DOTA).

OBJECTIVE: The purpose of this study was to assess the diagnostic value and safety of the contrast agent gadoterate meglumine (Gd-DOTA, DOTAREM, Guerbet, Roissy CdG Cedex, France) in the setting of a postmarketing surveillance study. MATERIALS AND METHODS: Between January 2004 and October 2005, radiologists in 61 radiologic institutions were asked to document the routine use of Gd-DOTA in a questionnaire. In addition to assessing the image quality and diagnostic value of the contrast-enhanced magnetic resonance imaging scans, we statistically evaluated and analyzed demographic and safety data. RESULTS: A total of 24,308 patients were intravenously injected with Gd-DOTA for various diagnostic examinations. The examination allowed for establishing a diagnosis in >99% of cases and image quality was rated as "excellent" or "good" in 97.5% of all cases. Adverse events were noted in only 0.4% of the examinations and were mostly rated as minor, such as feeling of warmth or taste alteration. There was one serious adverse event, albeit with complete recovery. CONCLUSION: This postmarketing surveillance study suggests diagnostic efficacy and a favorable clinical safety profile of Gd-DOTA in clinical practice.

Adverse Drug Reaction Reporting Systems↗
PubMed2006

Quantification of aortic valve stenosis in MRI-comparison of steady-state free precession and fast low-angle shot sequences.

We compared two different magnetic resonance (MR) sequences [steady-state free precession (SSFP) and gradient echo fast low-angle shot (FLASH)] for the assessment of aortic valve areas in aortic stenosis using transesophageal echocardiography (TEE) as the standard of reference. Thirty-two patients with known aortic stenosis underwent MR (1.5 T) using a cine SSFP sequence and a cine FLASH sequence. Planimetry was performed in cross-sectional images and compared to the results of the TEE. In seven patients the grade of stenosis was additionally assessed by invasive cardiac catheterization (ICC). The mean aortic valve area measured by TEE was 0.97+/-0.19 mm(2), 1.00+/-0.25 mm(2) for SSFP and 1.25+/-0.23 mm(2) based on FLASH images. The mean difference between the valve areas assessed based on SSFP and TEE images was 0.15+/-0.13 cm(2) (FLASH vs TEE: 0.29+/-0.17 cm(2)). Bland-Altman analysis demonstrated that measurements using FLASH images overestimated the aortic valve area compared to TEE. Comparing ICC with MRI and TEE, only a weak to moderate correlation was found (ICC vs TEE: R=0.52, p=0.22; ICC vs SSFP: R=0.20, p=0.65; ICC vs FLASH: R=0.16, p=0.70). Measurements of the aortic valve area based on SSFP images correlate better with TEE compared to FLASH images.

Aged↗
PubMed2006

Time-resolved contrast-enhanced magnetic resonance angiography of the hand with parallel imaging and view sharing: initial experience.

We sought to compare a three-dimensional, contrast-enhanced, magnetic resonance angiogram (3D CE MRA) sequence combining parallel-imaging (generalised autocalibrating partially parallel acquisitions (GRAPPA)) with a time-resolved echo-shared angiographic technique (TREAT) in an intraindividual comparison to a standard 3D MRA sequence. Four healthy volunteers (27-32 years), and 11 patients (11-82 years) with vascular pathologies of the hand were examined on a 1.5-Tesla (T) MR system (Magnetom Avanto, Siemens, Erlangen, Germany) using two multichannel receiver coils. Following automatic injection (flow rate 2.5 cc/s) of 0.1 mmol/kg gadoterate (Dotarem, Guerbet, Roissy, France), 32 consecutive 3D data sets were collected with the TREAT sequence (TR/TE: 4.02/1.31 ms, FA: 10 degrees, GRAPPA acceleration factor: R=2, TREAT factor: 5, voxel size: 1.0 x 0.7 x 1.3 mm(3)) and a T1-wwighted 3D gradient-echo sequence (TR/TE: 5.3/1.57 ms, FA: 30 degrees, GRAPPA acceleration factor: 2, voxel size: 0.71 x 0.71 x 0.71 mm(3,)). MR data sets were evaluated and compared for image quality and visualisation of vascular details. In the volunteer group, all MR imaging was successful while technical problems prevented acquisition of the standard protocol in two patients. For the corresponding segments, the number of visible segments was equal on both sequences. Overall image quality was significantly better on the standard protocol than on the TREAT protocol. TREAT MRA provided functional information in lesions with rapid blood flow, e.g. detection of feeding and draining vessels in an haemangioma. TREAT-MRA is a robust technique that combines morphological and functional information of the hand vasculature and deals with the very special physiological demands of vascular lesions, such as quick arteriovenous transit time.

Adolescent↗
PubMed2006

Magnetic resonance cardiac perfusion imaging-a clinical perspective.

Coronary artery disease (CAD) with its clinical appearance of stable or unstable angina and acute myocardial infarction is the leading cause of death in developed countries. In view of increasing costs and the rising number of CAD patients, there has been a major interest in reliable non-invasive imaging techniques to identify CAD in an early (i.e. asymptomatic) stage. Since myocardial perfusion deficits appear very early in the "ischemic cascade", a major breakthrough would be the non-invasive quantification of myocardial perfusion before functional impairment might be detected. Therefore, there is growing interest in other, target-organ-specific parameters, such as relative and absolute myocardial perfusion imaging. Magnetic resonance (MR) imaging has been proven to offer attractive concepts in this respect. However, some important difficulties have not been resolved so far, which still causes uncertainty and prevents the broad application of MR perfusion imaging in a clinical setting. This review explores recent technical developments in MR hardware, software and contrast agents, as well as their impact on the current and future clinical status of MR imaging of first-pass myocardial perfusion imaging.

Contrast Media↗
PubMed2006

Successful nitinol stent implantation in a large coronary aneurysm: post-interventional patency assessment by magnetic resonance imaging.

Nitinol stents are thought to exhibit reduced occurrence of artifacts and may be suitable for magnetic resonance imaging (MRI) evaluation of stent localization and in-stent patency even in coronary-sized stent grafts. A 54-year-old male patient presented with a large coronary post-stenotic aneurysm of the right coronary artery (RCA) beside significant stenoses of the left circumflex coronary artery (LCX) and the left anterior descending coronary artery (LAD) with aneurysm formation. After implantation of stent grafts to the LAD and LCX, two polymermembrane-covered nitinol stent grafts were placed into the RCA. A control MR examination 7 days following the RCA intervention showed successful occlusion of the former aneurysm, no post-interventional endoleak, and bright signal within the stent indicating stent patency. Thus, coronary MRI after nitinol stent implantation in coronary aneurysms is feasible for post-interventional early imaging control at least as far as the exclusion of possible endoleaks is concerned.

Alloys↗
PubMed2006

Coronary atherosclerosis and cardiovascular risk in masters male marathon runners. Rationale and design of the "marathon study".

BACKGROUND: Regular physical exercise is recommended to reduce cardiovascular mortality. And yet, atherosclerosis is the main cause of exercise-associated death in persons beyond age 35. The need for risk stratification in marathon runners is under discussion. The predictive value of modern imaging- and non-imaging-based markers of risk that can be used for risk stratification in masters endurance athletes still deserves exploration. METHODS: Male runners > 50 years who have completed at least five marathon races during the preceding 3 years and do not suffer from coronary artery disease, angina nor diabetes mellitus are studied to assess the predictive value of established and modern imaging- based and biochemical cardiovascular risk factors. Laboratory parameters including clinical chemistry, hematology and hormone measurements are determined. Lifestyle-related risk factors, psychosocial and socioeconomic variables are explored using standardized questionnaires. Coronary, carotid, femoral and aortic atherosclerosis is measured using electronbeam computed tomography and ultrasound. In addition, a resting ECG, a bicycle stress test and heart rate variability are performed. Myocardial morphology and function are assessed using echocardiography and magnetic resonance imaging. Participants are invited to compete in a marathon race to quantify the association of coronary atherosclerosis with marathon-related changes of cardiac troponin levels and the extent of marathon-induced inflammation. At the cellular level, the effect on the amount of circulating progenitor cells (EPCs) is determined by FACS analysis. Changes in laboratory parameters and hormone levels are also studied. Annual long-term follow-up including hospital records and death certificates is performed. Data are compared with those from a general unselected cohort from the Heinz Nixdorf Recall Study. CONCLUSION: This study should contribute to cardiovascular risk assessment in the growing number of masters marathon runners with a focus on assessing the predictive value of modern imaging techniques and biochemical markers for comprehensive risk stratification.

Adult↗
PubMed2005

Myocardial infarct: depiction with contrast-enhanced MR imaging--comparison of gadopentetate and gadobenate.

Institutional review board approval and patient written informed consent were obtained. On two separate occasions, 24 hours apart, contrast-enhanced cardiac magnetic resonance (MR) imaging was performed prospectively at 1, 3, 5, 10, and 20 minutes after injection of gadopentetate dimeglumine and gadobenate dimeglumine in 15 patients (11 men, four women) with history of myocardial infarction. Both agents allowed detection of infarcted myocardium. T1 values at all times were significantly (P < .05) lower for gadobenate, compared with values for gadopentetate, in both infarcted and noninfarcted myocardium. At 1 minute after administration of both agents, T1 values in left ventricular cavity (LVC) were not different; at 3-20 minutes after injection, values were significantly (P < .05) lower for gadobenate. Differences between contrast-to-noise ratio (CNR) values of infarcted and noninfarcted myocardium were significantly higher on gadobenate-enhanced images (P < .05). CNR values between infarcted myocardium and LVC were significantly higher on gadopentetate-enhanced images (P < .05). Gadopentetate might permit better delineation of infarcts, especially subendocardial infarcts.

Aged↗
PubMed2005

[Diagnosis of cardiac disorders by noninvasive techniques in HIV-infected patients].

HIV infection is frequently associated with cardiovascular involvement. Particularly new treatment concepts, including the highly active antiretroviral therapy, are suspected to increase the rate of cardiac and cardiovascular complications in this patient population. Hence, noninvasive techniques such as transthoracic echocardiography and magnetic resonance imaging will become more important in the routine screening as well as in specific diagnostics of cardiovascular involvement of HIV infection. The present article describes the options of these noninvasive techniques for the detection of HIV-associated cardiac manifestations.

Echocardiography↗
PubMed2005

Late enhancement: a new feature in MRI of arrhythmogenic right ventricular cardiomyopathy?

Aim of the study was to evaluate whether late enhancement (LE) in contrast-enhanced MRI can be used to characterize fibrofatty myocardial replacement in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC). Fifteen patients with suspected ARVC underwent CE-MRI using a 1.5 T scanner. Long and short axis SSFP cine images and T1-weighted fast spin echo images were collected in all patients. After injection of 0.2 mmol/kg Gd-DTPA (Magnevist, Schering, Berlin, Germany), inversion recovery gradient echo images were acquired in long and contiguous short axes to detect myocardial LE indicating areas of fibrous tissue within the myocardium. For definition of ARVC, the ESC Task force criteria were used. In 7 (47%) of 15 patients, ARVC was diagnosed based on the ESC criteria. In all of these 7 patients, MRI showed morphologic or functional criteria of ARVC according to the ESC. LE of the right ventricular myocardium was detected in 5 (71%) of the 7 ARVC patients, additional LE of the left ventricular myocardium in 2 of these patients. None of the 7 patients meeting the ARVC diagnostic criteria had fatty RV infiltration demonstrable by conventional T1-weighted imaging. Eight patients neither showed morphologic criteria of ARVC nor LE. In conclusion, late enhancement can be detected in the right and left ventricular myocardium in some ARVC patients. LE might represent intramyocardial areas of fibrous tissue.

Adult↗
PubMed2005

Rapid progression of discrete type A intramural hematoma: prevention of a "procedure-related" complication by intraoperative transesophageal echocardiography.

PURPOSE: To report a case illustrating the utility of transesophageal echocardiography (TEE) before planned stent-graft placement for chronic type B aortic dissection. CASE REPORT: A 64-year-old man with acute aortic syndrome and an 8-year-old interposition graft in the distal aortic arch for acute type B dissection was referred for dissection of the descending thoracic aorta down to the aortic bifurcation; the false lumen was dilated to 65 mm and was partially thrombosed. The ascending aorta showed discrete, eccentric, 4-mm wall thickening that was not considered clinically significant. Stent-graft closure of the entry tear in the proximal descending thoracic aorta was elected. However, as the endovascular procedure was about to commence, TEE showed striking eccentric thickening of the aortic wall of up to 18 mm. The endovascular procedure was stopped, as it was decided to urgently replace the ascending aorta. The next day, the patient underwent successful ascending aortic replacement and simultaneous antegrade stent-graft implantation over the descending thoracic aortic entry tear via the open aortic arch. The postoperative course was uncomplicated, and the patient was discharged 19 days after surgery. He remains well at 6 months after the procedure. CONCLUSIONS: Our case demonstrates that dissection of the ascending aorta may occur not only due to endograft-induced intimal injury, but may also occur due to underlying but undiagnosed or underestimated disease of the ascending aorta or arch. Besides procedural guidance, intraoperative TEE is a useful tool to detect such disease to avoid subsequent "procedure-related" complications.

Aortic Dissection↗
PubMed2005

Detection of pulmonary nodules using a 2D HASTE MR sequence: comparison with MDCT.

OBJECTIVE: The objective of our study was to determine the diagnostic performance of MRI based on a HASTE sequence for the detection of pulmonary nodules in comparison with MDCT. MATERIALS AND METHODS: Thirty patients with known pulmonary nodules underwent both MRI and CT. CT of the lung served as the standard of reference and was performed on a 4-MDCT scanner using a routine protocol. MRI was performed with axial and coronal HASTE sequences using a high-performance 1.5-T MR scanner. Image data were analyzed in three steps after completion of all data acquisition. Step 1 was the analysis of all the CT image data. Step 2 was the analysis of all the MR image data while blinded to the results of the CT findings. Step 3 closed with a simultaneous review of all corresponding CT and MRI data, including a one-to-one correlation of the size and location of all the nodules that were detected. RESULTS: Compared with the sensitivity of CT, the sensitivity values for the HASTE MR sequence were as follows: 73% for lesions less than 3 mm, 86.3% for lesions between 3 and 5 mm, 95.7% for lesions between 6 and 10 mm, and 100% for lesions larger than 10 mm. The overall sensitivity of the HASTE sequence for the detection of all pulmonary lesions was 85.4%. CONCLUSION: An MRI examination that consists of a HASTE sequence allows one to detect, exclude, or monitor pulmonary lesions that are 5 mm and bigger. Suspicious lesions smaller than 5 mm still need to be validated using CT.

Adult↗
PubMed2005

Assessment of left ventricular parameters using 16-MDCT and new software for endocardial and epicardial border delineation.

OBJECTIVE: The purpose of our study was to quantify left ventricular function and mass derived from retrospectively ECG-gated 16-MDCT coronary angiography data sets using a new analysis software based on automatic contour detection in comparison to corresponding standard of reference measurements acquired with MRI. SUBJECTS AND METHODS: Multiplanar reformations in the short-axis orientation were calculated from axial contrast-enhanced CT images in 18 patients (men, 15; women, three; age range, 38-70 years; mean, 57.4 +/- 10.2 [SD] years) who were referred for CT coronary angiography. End-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), and left ventricular mass (LVM) were analyzed with a recently developed imaging software using an automated contour detection algorithm of left ventricular endo- and epicardial contours and by manual tracing. The data were compared with similar measurements on MRI as the standard of reference. RESULTS: EDV, ESV, EF, and LVM derived from an automated contour detection algorithm were not statistically significantly different from manual tracing (CT(auto) vs CT(manual): EDV = 137.1 +/- 45.7 mL vs 134.2 +/- 39.9 mL, ESV = 58.8 +/- 34.2 mL vs 58.1 +/-30.1 mL, EF = 59.2% +/- 13.7% vs 58.1% +/- 12.0%, LVM = 130.9 +/- 29.1 g vs 133.7 +/- 33.2 g; p > 0.05). However, EDV (118.7 +/- 43.6 mL), ESV (50.1 +/- 33.5 mL), and LVM (142.8 +/-38.4 g) as calculated on MR data sets were statistically significantly different from those calculated on CT (p < 0.05), whereas MRI-based EF (59.9% +/- 14.4%) did not differ statistically significantly from those based on both CT algorithms (p > 0.05). CONCLUSION: Automatic and manual analysis of data acquired during CT coronary angiography using a 16-MDCT scanner allows a reliable assessment of left ventricular ejection fraction and a rough estimation of left ventricular volumes and mass.

Adult↗
PubMed2005

Myocardial late enhancement in contrast-enhanced cardiac MRI: distinction between infarction scar and non-infarction-related disease.

OBJECTIVE: Our objective was to assess and compare the patterns of late enhancement (LE) in contrast-enhanced cardiac MRI caused by myocardial infarction and different myocardial diseases that are not related to ischemic infarction. MATERIALS AND METHODS: A total of 811 consecutive contrast-enhanced cardiac MRI studies performed for different indications were reviewed for left ventricular myocardial LE after gadopentetate dimeglumine administration. MRI studies were performed on a 1.5-T scanner using an inversion recovery turbo FLASH sequence (TR/TE, 8/4 msec; flip angle, 25 degrees). The LE pattern of ischemic infarction scar was compared with that in nonischemic myocardial disease. RESULTS: LE was found in 421 (52%) patients. In all patients with myocardial infarction, LE included the subendocardial layer. Nineteen patients without history of myocardial infarction and angiographically excluded coronary artery disease showed different patterns of LE caused by myocarditis, sarcoidosis, arrhythmogenic right ventricular dysplasia, cardiomyopathy, endomyocardial fibrosis, and iatrogenic scars after biopsy, ablation of septal hypertrophy, and myocardial laser revascularization. CONCLUSION: LE in contrast-enhanced cardiac MRI is not specific for ischemic infarction. LE in ischemic infarction always involves the subendocardial layer, whereas it does not necessarily do so in other myocardial diseases. Therefore, if LE omit the subendocardial layer, different nonischemic myocardial diseases have to be considered. The pattern of LE might be helpful for the differential diagnosis of myocardial disease and in distinguishing it from ischemic disease.

Adult↗
PubMed2004

Coronary artery calcium score: influence of reconstruction interval at 16-detector row CT with retrospective electrocardiographic gating.

In 30 patients, Agatston and volumetric scores were assessed by using retrospectively gated multi-detector row computed tomography (CT). For each patient, 10 data sets were created at different times and were evenly spaced throughout the cardiac cycle. For each reconstruction, patients were assigned a percentile that described the level of cardiovascular risk. Nineteen (63%) of 30 patients could be assigned to more than one risk group depending on the reconstruction interval used. Agatston and volumetric scores both proved highly dependent on the reconstruction interval used (coefficient of variation, < or =63.1%) even with the most advanced CT scanners. Accurate and reproducible quantification of coronary calcium seems to require analysis of multiple reconstructions.

Adult↗