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Biomedical subjects

K Lackner

Publications and source records attributed to K Lackner.

At least 127 records · Page 7Linked to original sources
PubMed1990

Collateral pathways in portal hypertension.

In a retrospective study angiographic image material of percutaneous direct portographies carried out in 43 patients was evaluated according to anatomic and radiologic criteria. These examinations were performed for therapeutic purposes (embolisation of vessels supplying varices). All the hepatofugally perfused veins were analyzed according to their localisation and course. Apart from the known portocaval collateral pathways a number of other collaterals not yet described could be documented by means of angiography.

Aged↗
PubMed1990

[Gadolinium-DTPA as an oral contrast medium for MR tomography of the abdomen].

150 MR examinations of the upper abdomen were carried out after the oral administration of 5 ml/kg body weight of a gadolinium DTPA formulation (1.0 mmol/l, 15 g/l mannitol), with reference to the delineation of the pancrease, the liver and intra-abdominal fat. For comparison, 100 MR examinations without oral opacification of the G.I. tract were evaluated. Contrast administration resulted in a signal-intensive demonstration of the G.I. tract for all measurement sequences. The intraluminal contrast improved the distinction between normal and abnormal structures. T1 and T2 sequences and the demonstration of fat on T2-weighted series. T1-weighted series showed the best diagnostic results. In 25% there was meteorism and diarrhoea within 24 hours of the administration of the oral contrast.

Abdomen↗
PubMed1990

[The value of color-coded duplex sonography of a dialysis shunt].

Two hundred and sixty-four shunt segments in 43 patients with 66 dialysis shunts were examined by colour-coded duplex sonography and the results compared with DSA. Sonography demonstrated shunt stenoses with an accuracy of 93.9% (sensitivity 90.6%, specificity 95.8%). Only central venous stenoses were shown better by DSA than by sonography. Sonography showed occlusions with a sensitivity of 83.3% and a specificity of 100%. All aneurysms demonstrated by DSA were correctly identified by sonography. In 18 patients PTA of the shunt was performed. The result of treatment could be quantified by measuring flow by means of sonography. The study confirmed the value of duplex sonography as a noninvasive diagnostic method for investigating insufficient dialysis shunts.

Adult↗
PubMed1990

[Dilatation and balloon-expandable stents for the treatment of central venous stenosis in dialysis patients].

On 10 dialysis patients we performed 12 balloon dilatations, 2 catheter lyses, 6 stent implants (Palmaz stent) and one atherectomy of central venous stenoses or occlusions (v. subclavia, v. brachiocephalica) at the shunt arm of the patient. The primary success rate was, in balloon PTA and lysis, 12/14 interventions, and in stent placement and atherectomy 7/7. The angiographical and clinical primary result after stent implantation was significantly better than after conventional dilatation. After 66% of the balloon dilatations recidivation occurred within the first year; this can be treated by means of repeated PTA. Whether long-term exclusion of recurrence can be achieved by stent implantation, must be established by means of follow-up studies that are at present in progress.

Adult↗
PubMed1990

[Color-coded duplex sonography before and after PTA of the arteries of the lower extremities].

The value of color-coded duplex sonography in the pelvic and lower limb arteries was studied prospectively in 52 patients and the findings were compared with intra-arterial DSA. There was high diagnostic accuracy (sensitivity 91.7%, specificity 98.9%) for the demonstration of vascular abnormalities. In 84.3% of cases a correct diagnosis could be obtained based entirely, or largely, on the color-coded signal. Both before and after PTA color-coded duplex sonography is a non-invasive method that is superior to conventional duplex sonography.

Angiography, Digital Subtraction↗
PubMed1990

[Magnetic resonance tomography (MRT) of the hand in chronic polyarthritis].

Forty hands of 39 patients with rheumatic joint disease were examined by MRT. The method differentiates between inflammatory exudative and proliferative processes in soft tissues and bone. T2-weighted images provided criteria for judging the activity of the disease. MRT provided better demonstration of the soft tissues than just conventional radiography. The methods were of equal value for showing bone lesions. MRT is suitable as a means of diagnosing rheumatoid changes in the hand.

Adult↗
PubMed1990

[Indications for cardio-MRT].

Cardio-MRT provides complex diagnostic information (morphology, function, biochemistry) with little stress for the patient and is therefore used increasingly for clinical diagnosis. There is great need for interdisciplinary studies concerning function, the use of contrast media and spectroscopy.

Animals↗
PubMed1989

[Imaging properties of digital image-intensifier radiography compared to the conventional x-ray technic for chest pictures].

Projection properties of a digital fluorographic system for chest examinations are examined using varying test phantoms. A maximal geometric distortion of +14% between the centre and the periphery of the image intensifier and a maximal spatial resolution of 2.6 LP/mm is found. Contrast detail diagrams are used to show the combination of spatial and contrast resolution of the system. Compared with diagrams for conventional radiographic systems there is a significant loss of resolution.

Adolescent↗
PubMed1989

[In vitro measurement of intravascular blood flow with color Doppler sonography].

The accuracy of colour Doppler sonography for measuring various aspects of intravascular flow (volume and velocity), under varying conditions, was studied experimentally. The effect of variable Doppler angles, different flow paths, frequency and vessel diameter on flow profiles was examined. At all levels of measurement (range 14 ml/min to 566 ml/min) there was a very close correlation between the actual and measured values (r greater than 0.99) and high accuracy. In the detection of very slow flow rates, the use of a specific high pass filter technique was able to quantify blood flow velocities of just under 1 cm./second. Multigated colour Doppler sonography is better for measuring flow volumes than a single channel duplex system.

Blood Flow Velocity↗
PubMed1989

[Computed tomographic volumetry of the orbit in endocrine orbitopathy].

The volumes of the four recti muscles and the orbital fat was measured by CT in 40 normal persons and in 60 patients with clinically confirmed Graves' disease. Compared with normal persons, 42 patients (70%) showed an increase in muscle volume and 28 patients (46.7%) an increase in the amount of fat. In nine patients (15%) muscle volume was normal, but the fat was increased. By using volumetric measurements, the amount of fat in the orbits in patients with Graves' disease could be determined.

Adipose Tissue↗
PubMed1989

[Angiography in intensive care medicine].

Angiography is rarely performed in the intensive-care ward. Indications are: pulmonary embolism, unstable angina pectoris or myocardial infarction, gastrointestinal haemorrhage, acute arterial occlusion, traumatic vascular lesions, aneurysms and if a foreign body has to be extracted. It will always be necessary to weigh the pros and cons, that is to say the risks and danger involved in transporting the patient and in performing an invasive diagnostic procedure on the one hand, and the possible therapeutic gain on the other.

Angiography↗
PubMed1989

[Percutaneous drainage of recurrent peripancreatic fluid collections in acute pancreatitis. A case report].

The case of a 36 year old patient with acute pancreatitis is presented whose clinical course was dominated by extensive peripancreatic fluid exsudation and formation of cysts. Risky surgery in the acute phase of the disease could be avoided by ultrasonic guided percutaneous punction and placing of several, partly transhepatic, catheters. The fluid collections could be drained completely and showed no recurrence.

Acute Disease↗
PubMed1988

Conventional computerized tomography of the heart.

Ungated cardio-CT provides good morphologic information in the case of congenital heart disease, volume or pressure loading, left ventricular aneurysm, tumours, thrombi, cardiac calcifications and pericardial diseases. It allows qualitative assessments of myocardial thickness and perfusion of coronary bypass grafts. ECG-gated cardio-CT allows a quantitative assessment of systolic and diastolic myocardial thickness, volume calculation of cardiac cavities and evaluation of functional parameters. The correlation of the calculated left ventricular ejection fraction comparing laevocardiography and ECG-gated cardio-CT was poor (r = 0.7) mainly due to the comparable poor time resolution on the side of cardio-CT (approximately 0.1s). The quantitative analysis of regional wall motion based on cardio-CT showed for the diagnosis of pathologic wall motion a specificity of 80.5%, sensitivity of 73.9% and accuracy of 75.7%. Side effects must be taken into account following the injection of 200-250 ml hyperosmolar contrast medium during 5-10 minutes which causes intravascular fluid retention and cardiac volume loading. Patients prone to cardiac decompensation should be excluded from cardio-CT examinations.

Cardiomyopathy, Dilated↗
PubMed1988

[Color Doppler sonography: non-invasive potential for morphologic and functional vascular diagnosis].

A linear array colour Doppler sonographic method was used experimentally on a vessel phantom in order to determine flow velocity, and the results were compared with DSA. Both the Doppler and the DSA method showed very good agreement with true velocities (r greater than 0.97). The Doppler method underestimated flow velocity. Early clinical results indicate that colour Doppler sonography is able, at the same time, to demonstrate morphology and function (direction flow and flow velocity) of significant vascular abnormalities by a non-invasive method.

Blood Flow Velocity↗