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Biomedical subjects

L Lauterjung

Publications and source records attributed to L Lauterjung.

31 records · Page 2Linked to original sources
PubMed1989

The value of cw-Doppler ultrasonography and DSA in the diagnosis of extra- and intracranial stenosis--a comparison with intraoperative findings.

The use of cw-Doppler sonography and digital subtraction angiography (DSA) for diagnosis of cerebro-vascular insufficiency (CVI) was evaluated in a retrospective study. 113 findings obtained by DSA and 315 findings obtained by cw-Doppler sonography were compared to the corresponding intraoperative finding. Furthermore, we examined the incidence of accompanying intracranial stenoses of the carotid artery. The impact of these stenoses on the CVI stage was analyzed by means of 200 transcranial Doppler sonographic studies. Cw-Doppler sonography (sensitivity: 95%) was clearly superior to DSA (sensitivity: 70%) for diagnosis of high grade and subtotal stenoses of the internal carotid artery (ICA). Sensitivity of both methods was insufficient for diagnosis of low grade stenoses (cw-Doppler: 50%, DSA 25%). Analysis of 200 transcranial Doppler sonographic studies did not reveal pathologic changes of intracranial vessels in 67% of all cases. This finding did not depend on the condition of the extracranial vessels and did also not depend on the CVI stage. Additionally, there was no correlation between the incidence and degree of intracranial stenoses and the CVI stage or the degree of stenosis of the ICA. These results support the view that Doppler sonography is the method of choice for diagnosis of high grade stenoses of the carotid artery. The use of DSA is limited to cases in which kinking or occlusion is suspected. Additional intracranial changes did not correlate with the CVI stage.

Angiography↗
PubMed1988

Percutaneous removal of atheromatous plaques in peripheral arteries.

The peripheral Simpson "atherectomy" catheter was used to treat 21 patients with a total of 41 stenotic lesions (5 iliac, 35 superficial femoral, and 1 popliteal). 4 lesions were totally occluded and 16 (39%) were calcified. The mean (SD) degree of obstruction was reduced from 82.7 (14) to 21 (16)% (p less than 0.0001). Mean (SD) standardised walking distance increased from 79.9 (71.9) to 152.6 (89.7) m (p less than 0.0001); doppler index improved from 0.58 (SD 0.17) to 0.81 (0.16) (p less than 0.0001); performance on bicycle stress test rose from 276.3 (range 1-1100) to 584.8 (2-2250) watt-min; and index for 201Tl-scintigraphy of the lower leg increased from 0.68 (0.28) to 0.91 (0.36) (p less than 0.02). The improvement has been maintained for 6 months, the degree of stenosis on repeat angiography at 2-6 months (n = 14 lesions) being 20.7 (SD 13.7)% (unchanged from early post-treatment values). The only restenosis has been corrected by a repeat of the percutaneous procedure.

Aged↗
PubMed1988

[Aneurysm of the arteria lusoria. Case report and review of the literature].

Aneurysms arising from an aberrant subclavian artery represent a seldom but dangerous condition, which can be treated successfully when appropriately diagnosed. From 37 patients described in the literature most presented a mediastinal mass and had symptoms like dysphagia, dyspnoe or chest pain. Diagnosis is today possible by contrast-enhanced computed tomography. The aneurysm should be resected to prevent lethal rupture. Left thoracotomy seems to be the appropriate approach in most cases. Reestablishment of blood flow to the right subclavian artery seems not necessary and may be done if ischemia develops in a second procedure by subclavian transposition to the common carotid artery. The case of a 74-year-old women who had resection of an aneurysm in an aberrant subclavian artery is described together with a review of the literature and discussion of the surgical management.

Aged↗
PubMed1988

[High resolution MR angiography with rephasing and dephasing sequences for selective vascular imaging of arteries and veins].

With rephasing and dephasing sequences the vascular system is imaged with high or low signal intensity whereas stationary tissue is imaged with identical signal intensity. With images recorded in systole and diastole followed by image subtraction separate imaging of arteries or veins without background superposition is possible. 13 patients with vascular lesions of the lower extremities and 7 volunteers were examined. Vascular stenosis, aneurysm, dilatation, occlusion and collateral vessels could be imaged similar to digital subtraction angiography. Vessels with a diameter down to 1 mm could be imaged. The large slice thickness up to 80 mm results in projection type images where the vascular tree is imaged over the whole field of view and without partial volume effects.

Arteries↗
PubMed1987

[Personal catheter technic for intra-arterial chemotherapy in cancers of the head and neck].

Regional intraarterial chemotherapy can display its advantages as augmented concentrations of effective substances within the tumour tissue and lower systemic side effects, only if tumour perfusion can be carried out superselectively. For different reasons, the present techniques have not been accepted for extensive clinical use. A new catheter technique is, therefore, presented that is appropriate for both clinical routine and superselective tumour perfusion.

Antineoplastic Agents↗
PubMedDate not supplied

Analysis of laser Doppler flux motion in man: comparison of autoregressive modelling and fast Fourier transformation.

In order to investigate laser Doppler (LD) flux motion in healthy subjects and patients with peripheral arterial occlusive disease (PAOD), spectrum analysis of LD signals is needed. Autoregressive analysis (AR) is presented as an alternative method of power spectrum estimation. This procedure is compared to the commonly used fast Fourier transform algorithm (FFT) by describing the analytical power of both spectra in the analysis of flux motion waves. LD signals were recorded from the forefoot of 8 healthy volunteers and 11 patients with different degrees of PAOD. The flux, concentration of moving blood cells and velocity signal was digitized and stored for off-line analysis. Special software was designed to calculate AR and FFT spectra of the LD signals and to compare the suitability of both methods for the spectral analysis of LD recordings. Additionally, three-dimensional spectrum diagrams were calculated to demonstrate time-dependent flux changes during standardized provocation maneuvers. AR facilitates the determination of frequency and amplitude of flux motion waves as compared to the FFT. Low frequency-large amplitude waves (LF waves) were detected in both groups. High frequency-small amplitude waves (HF waves), which predominantly appear in severe ischemia, were observed in 7 of the 11 patients and in 2 of the 8 controls. The spectra revealed pulsatile waves in all healthy controls, but only in 1 of the 11 patients. AR modelling allows a reliable description of important flux motion components and has considerable advantages in spectral estimation of LD signals as compared to the FFT.

Algorithms↗
PubMedDate not supplied

Color-flow Doppler sonography in the identification of ulcerative plaques in patients with high-grade carotid artery stenosis.

PURPOSE: To assess the ability of color-flow Doppler sonography (CFDS) to detect plaque ulcerations in patients who had high-grade to thread-like carotid artery stenosis and who underwent carotid endarterectomy. METHODS: CFDS is a noninvasive diagnostic technique that allows, in addition to spatial visualization of blood flow, the identification of abnormal blood flow patterns such as vortex formation. There is evidence that pathologic anatomic changes in the vascular wall (such as ulcerations) may result in characteristic hemodynamic alterations. Therefore, solely hemodynamic criteria (detection of vortices) were used to diagnose ulceration. The results of preoperative examinations were compared to the intraoperative findings in 89 patients in a prospective and blinded way. RESULTS: CFDS proved highly sensitive (95.3%), specific (93.5%), and accurate (94.0%) for demonstrating ulcerative plaques. CONCLUSION: CFDS may be of significant advantage for examining plaque morphology in patients who have high-grade internal carotid artery stenosis, and in whom accurate, noninvasive diagnosis of plaque ulceration was previously difficult, if not impossible.

Aged↗