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U Helber

Publications and source records attributed to U Helber.

25 records · Page 2Linked to original sources
PubMed1996

Evaluation of K-space segmented cine sequences for fast functional cardiac imaging.

RATIONALE AND OBJECTIVES: In functional cardiac magnetic resonance imaging, reduction of measuring time is very important for many patients who are not able to rest motionless for long-lasting examinations. In this study, the image quality of sequences with k-space segmented data recording was compared with conventional gradient-echo sequences for cine imaging with flow compensation in applications on patients with normal and reduced ejection fractions. METHODS: Thirty-one subjects (4 volunteers and 27 patients with cardiac diseases) were examined using different techniques for cine imaging of the left and right ventricles. The ejection fraction in the patients was calculated based on images of a conventional two-dimensional gradient-echo technique using a biplane ellipsoid model. The results from k-space segmented methods (3 to 9 Fourier lines per cardiac cycle for each phase image) were compared with the conventional images of the same short-axis view separately for groups of subjects with normal and reduced ejection fraction. The contrast between blood and myocardium at several sites of the heart and the homogeneity of the blood signal in the ventricle were evaluated for several phases of the heart cycle. RESULTS: The segmentation in the acquisition of raw data allows reduction of measuring time to approximately 20% to 40% of the time required for conventional sequences in cine imaging of the heart. In patients with normal or only slightly reduced heart function (ejection fraction > or = 60%) the image quality of k-space segmented sequences was not significantly different from the conventionally recorded images. In contrast, patients with markedly lowered ejection fraction (< 60%) showed degraded results of the k-space segmented sequences compared with the conventional sequence (P < 0.001). The anterolateral border and the right ventricle especially were not sufficiently delineated by the k-space segmented sequences in these patients. CONCLUSION: The k-space segmentation for the reduction of examination time is suitable for measuring heart volumes and functional parameters of patients expected to have a nearly normal ejection fraction, whereas for patients with markedly reduced cardiac function further technical improvements of segmented techniques are necessary.

Adult↗
PubMed1996

Tricuspid valve endocarditis due to a jet lesion detected by echocardiography in a 27-year old man with congenital ventricular septal defect.

The case of an non-addict young caucasian with isolated tricuspid valve endocarditis in congenital ventricular septal defect (VSD) is presented. Despite antibiotic treatment the patient suffered from recurrent right sided pneumonias. A computed tomography of the chest revealed an abscess localized in the right lower lung with signs of cavitation. Echocardiography identified a vegetation located at the anterior tricuspid leaflet due to a jet lesion through the VSD. ECG-gated MRI revealed normal left ventricular function and localized the septal defect and a jet against the anterior tricuspid valve leaflet. The patient underwent open heart surgery and the VSD was closed. Now, two years later, the patient is free from any symptoms or complications. This case illustrates that noninvasive techniques like echocardiography and ECG-gated MRI can not only accurately image cardiac anatomy in patients with ventricular septal defect but additionally provide information about the pathomechanism of the development of jet lesions resulting in valvular vegetations. Operative correction of underlying cardiac disease in nonaddicts with complicating tricuspid valve endocarditis might be a favourable treatment especially when antibiotic treatment fails to cure the infection.

Adult↗
PubMed1994

Primary systemic amyloidosis leading to advanced renal and cardiac involvement in a 30-year old man.

The case of a 30-year-old man with primary systemic amyloidosis is reported. Three months prior to admission the patient developed fever, night sweats, dyspnea, and bilateral ankle swelling. Recurrent left-sided pleural effusion led to further investigation when massive proteinuria with free monoclonal lambda chains in the urine became evident. Abdominal subcutaneous fat aspiration and renal biopsy confirmed the diagnosis of amyloidosis. Bone marrow biopsy and bone scan did not reveal multiple myeloma. Echocardiography showed a sparkling texture of the interventricular septum. Pulsed-wave Doppler recording of the left ventricular inflow profile showed the pattern of advanced cardiac amyloidosis consistent with markedly impaired diastolic heart function. Electrocardiogram-gated magnetic resonance imaging was carried out for noninvasive evaluation of cardiac function. The patient was started on repeated courses of melphalan, prednisone, and colchicine therapy. Despite increasing deterioration of renal function the therapy was tolerated quite well, and the patient is still alive 10 months after initial diagnosis. Although very rare in this age, primary systemic amyloidosis should be considered as a cause of pleural effusion, proteinuria, and congestive heart failure and should lead to further investigation.

Adult↗
PubMed1994

[Perfusion of the left ventricular myocardium in patients with aortic valve diseases using single photon emission computerized tomography].

To determine resting myocardial perfusion in 30 patients with aortic valve disease (AVD) TI-201 emission computer tomography (ECT) studies and heart catheterization were performed. 16 patients had a predominant aortic regurgitation (AR); an aortic stenosis (AS) was found in 14 patients at catheterization. Perfusion defects were documented in 10 of 16 patients with AR, and in 5 of 14 patients with AS. Regional determination demonstrated in 10 of these 15 abnormal cases at least one of the perfusion defects in the postero-basal segment. In patients with aortic valve disease and normal myocardial perfusion scintigraphy, the ejection fraction (EF) was significantly higher (p < 0.05) as compared to the patients with abnormal TI-201 ECT (EF 65.2 +/- 15.0% vs. 58.9 +/- 15.1%). Additionally, in the 15 patients with abnormal TI-201 ECT, the left ventricular end-diastolic volume index (LVEDVI) and the left ventricular end-systolic volume index (LVESVI) were both increased (LVEDVI in AVD: 130.3 +/- 15.3 ml/m2 vs. 107.4 +/- 13.6 ml/m2, LVESVI in AVD: 61.9 +/- 14.6 ml/m2 vs. 48.0 +/- 9.8 ml/m2). In conclusion, left ventricular perfusion defects at rest can be detected by TI-201 ECT in many patients with aortic valve disease. Such myocardial perfusion defects indicate left ventricular enlargement and impaired left ventricular function, especially in patients with aortic regurgitation.

Adult↗
PubMed1993

Cortical DC-potentials in identification of the language-dominant hemisphere: linguistical and clinical aspects.

In order to find a non-invasive method for determining the hemispheric dominance for language, we studied cortical activation patterns during language processing by means of electrophysiological techniques: DC-potentials were recorded from frontal, central, temporal and parietal electrode positions in 28 right-handed normal subjects and in 16 patients with a history of transient loss of speech and known hemispheric dominance. Subjects were asked to find as many synonyms as possible within 6 seconds to either a concrete or an abstract noun. This task caused a highly significant left-hemispheric lateralization over frontal and central, but not over temporal and parietal cortical areas. Search for synonyms to abstract nouns yielded frontal left-hemispheric dominance in 93% of all normal subjects, search for synonyms to concrete nouns in 85%. Inter-electrode correlation coefficients were higher during processing of abstract word categories than during processing of concrete categories. In all patients, frontal and central lateralization corresponded to their hemispheric dominance as determined from clinical data. Advantages as well as inconveniences of this technique are discussed and compared to other invasive and noninvasive tools of assessing speech lateralization.

Adolescent↗
PubMed1992

Comparison of pulsed laser-assisted angioplasty and balloon angioplasty in femoropopliteal artery occlusions.

The authors performed a prospective, comparative study of 96 patients (age, 41-87 years) with femoropopliteal artery occlusions. Laser-assisted angioplasty was performed in 64 patients with 9- and 7-F over-the-wire multifiber catheters. Supplemental balloon dilation was performed after laser angioplasty. Thirty-two patients underwent excimer laser angioplasty (ELA), and 32 underwent pulsed dye laser angioplasty (DLA). The remaining 32 patients underwent conventional balloon angioplasty (BA). The length of occlusions was 3-10 cm (mean, 6.3 cm). Lesion characteristics in the three patient groups were similar. Technical success rates were 84% for ELA, 78% for pulsed DLA, and 81% for conventional BA. The 1-year clinical success rate was 69% (22 of 32 patients) in the ELA group, 63% (20 of 32 patients) in the pulsed DLA group, and 66% (21 of 32 patients) in the BA group (differences were not significant). Laser-assisted angioplasty with multifiber catheters in femoropopliteal artery occlusions did not help improve the technical success rate and 1-year clinical success rate when compared with those of conventional BA.

Adult↗