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Biomedical subjects

H Leitner

Publications and source records attributed to H Leitner.

At least 55 records · Page 3Linked to original sources
PubMed1989

[Three-dimensional irradiation planing].

A software for three-dimensional display of dose distributions in irradiation planning was developed which is based on the computed tomography (CT) data and dose matrices of the commercial irradiation planning system Mevaplan (Siemens). Isodoses with CT background can be reproduced in all planes lying in a normal position with respect to the CT plane and displayed perspectively in any combination. In order to achieve a better quantitative assessment of the dose distribution, an algorithm was introduced into Mevaplan allowing the calculation and display of dose-volume histograms and of the dose gradient.

Algorithms↗
PubMed1987

[Duplex sonography of the splenoportal axis].

48 patients with partial or complete portal vein thrombosis or tumor stenosis were examined by pulsed Doppler duplex scanning. In addition to the analysis of morphological changes, the pulsed Doppler duplex system yields functional data on the acceleration of blood flow in stenosis, flow in partial thrombosis and in differentiation between tubular cystic structures like arterial vessels, venous collaterals and dilated bile ducts. Qualitative and quantitative measurements of portal blood flow were performed in 55 cirrhotics and 15 healthy volunteers. Portal venous velocity and portal venous blood flow were significantly reduced in patients with cirrhosis. In 46 cases a hepatopetal blood flow was shown. In five cases a hepatofugal flow and in four cases a stagnant flow was found in the portal vein. Spontaneous portal systemic collaterals with hepatofugal flow were shown in 41% of cases. 11 patients with surgical portacaval shunts were examined. Patency was demonstrated in five patients where the anastomotic site was visible. Pulsed Doppler duplex sonography proved a valuable tool in the assessment of morphologic changes and revealed qualitative and quantitative data of portal venous hemodynamics.

Collateral Circulation↗
PubMed1987

[Occult and clinically suspected testicular tumor. Assessment using real-time sonography].

The diagnostic value of real-time-sonography was evaluated in 62 patients with suspected and occult testicular tumors. In 28 patients intratesticular tumors were identified on real-time-sonograms. In addition 7 clinically occult tumors were diagnosed by real-time-sonography. It was not possible to differentiate between orchitis and tumors on sonograms (3 cases). There was correlation only between the morphologic appearance of tumors on sonograms and the corresponding histology. Using high frequency transducers sonography proved to be an useful diagnostic modality to identify or to rule out occult intratesticular tumors.

Diagnosis, Differential↗
PubMed1987

[Standardized setup and dosimetry in total body irradiation using 3-dimensional compensators].

In order to obtain a homogenous dose distribution in total body irradiation, a compensator is inserted into the ray path. The different thickness and density of the patient is so compensated near the focus by a water equivalent metal layer. The faults arising in the calculation of the compensator are investigated. Furthermore a regulation technique is presented which allows a simple, rapid, and exact adjustment of patient, compensator, and measuring probes for dosimetry.

Humans↗
PubMed1987

[Sonography of the scrotal contents].

In 394 patients with various urological symptoms, the content of the scrotum was examined sonographically. 71 testicular lesions were found, 194 extratesticular pathologies were diagnosed. In 69% the enlargement of the testicle was due to a tumor, in 4 patients due to acute orchitis and in 3 patients due to acute torsion. An unilateral smaller sized testicle was found in chronic inflammation [5], cryptorchism [9], hypoplastic testicle [2] and after corticoid medication [1] and radiation therapy [1]. In normal sized testicles 8 tumors, 19 fibromas of the tunica albuginea, 2 scars after trauma and 1 haematoma were found sonographically. In 91% of patients with epididymitis the epididymis was enlarged. The echo structure was altered in 74%, in 13% abscesses were found. Sonography was useful in evaluation of scrotal herniation, especially when combined with hydroceles. Varicoceles were better detected and graduated by sonography than by clinical examination.

Genital Diseases, Male↗
PubMed1987

[Reaction of the tympanic tensor muscle--elicited by nasally applied trigeminal stimulants].

Computerised evaluation of tensor muscle reaction was carried out by using a biosignal analysing unit triggered by nasal inhalation. The trigeminus nerve was stimulated by application of 3-molar acetylacetic acid into the nasal respiratory air, inducing a contraction of the tympanic muscle, followed by a change in impedance. This change in impedance of the tympanic membrane ossicle system was recorded and printed out on a display. In this manner evidence was obtained of a tensor muscle reaction induced by the third branch of the trigeminal nerve as efference, and demonstrated for the first time. This reflex arc had long been considered as being of negligible clinical importance before its stimulation and measurement had become possible. It is a generally accepted theory that the reflex arc of the m. tensor tympani is linked to the formatio reticularis which assesses the sensory afferences. For this reason, the reflex arc habituates rapidly, and continuous stimulation is no longer possible.

Acetates↗
PubMed1986

[High-resolution realtime sonography of varicoceles].

An attempt has been made to classify varicoceles by means of real time sonography in accordance with the findings on palpation. The maximal diameter of the pampiniform plexus and of individual veins was determined sonographically and compared with the results of palpation in 74 patients with varicoceles. The sonographic findings are more accurate than is palpation. Fifteen subclinical varicoceles were discovered by sonography which could not be detected by palpation. It has been found convenient to classify the lesions in four sonographic stages. Maximal transverse diameter of the pampiniform plexus up to one centimetre is regarded as normal. A diameter of one to two centimetres corresponds to grade I, two to three centimetres corresponds to grade II and greater than three centimetres to grade III.

Humans↗
PubMed1986

[Real-time sonography in extranodal lymphoma].

Sonography is the primary imaging method for staging malignant lymphomas. The accuracy of sonography in diagnosing hepatic and splenic involvement was examined in 132 histologically proven cases. Focal involvement was differentiated from diffuse lymphoma. The value of sonography is discussed with reference to cases showing involvement of the gastro-intestinal tract, kidneys, suprarenals, pancreas, testes, breast, thyroid, parotid and muscle.

Breast Neoplasms↗
PubMed1986

[Pulsed duplex sonographic follow-up of varicoceles following sclerotherapy].

Forty-one patients were examined by pulsed duplex sonography immediately before and then one, four and twelve weeks following sclerotherapy of a varicocele. The severity of the varicocele was determined by sonography before treatment and confirmed by phlebography. Sonographic follow-up showed reduction, or disappearance, of the varicocele in 78% of cases. Doppler examination confirmed successful treatment in 85% of patients. Pulsed duplex sonography, combining a non-invasive imaging method and a functional technique, is well suited for the follow-up of varicoceles after treatment.

Follow-Up Studies↗
PubMed1985

[Bedside chest x-rays and extravascular lung water determination in intensive care patients].

Radiological staging of pulmonary oedema was compared with the determination of extra-vascular lung water by means of a double indicator dilution technique. One hundred and forty-six ward chest radiographs were evaluated and compared with the results of simultaneous measurements of lung water. Seventy-seven cases could be evaluated statistically. Chest x-rays regarded as normal corresponded to extra-vascular lung water of 5 to 9 ml./kg. body weight. Interstitial oedema (radiological stage I and II) corresponded to extravascular lung water levels of 8 to 12 ml./kg. Differentiation of stages I and II was not possible. During stage III, extra-vascular lung water was 15 to 21 ml./kg. A comparative analyses of these findings revealed a discrepancy of 34%. The reasons for this are discussed.

Adult↗
PubMed1985

[Sonography of the thyroid gland with high-resolution real-time equipment].

The results of sonography of thyroid glands in 131 patients were compared with the findings on palpation and from scintigrams. High resolution sonography is the most accurate method of examination for demonstrating changes in the thyroid. In 40% cases sonography demonstrated lesions additional to the single abnormality found clinically. In 10% cases a suspected thyroid abnormality on palpation proved to be due to extra thyroid disease. Evaluation of the number, size and localisation of space-occupying lesions by means of sonography is superior to all other kinds of investigation. It is, however, not possible to determine whether a lesion is benign. An attempt has been made to define the usefulness of thyroid sonography and its place during routine diagnosis.

Female↗
PubMed1985

[Occlusion or stenosis of the splenoportal axis. Supplementary information with duplex sonography?].

In 21 patients with sonographic signs of occlusions or stenoses of the splenoportal axis additionally pulsed Doppler measurements in the region of the splenic and portal veins were conducted with a Duplex system. Examinations using the pulsed Doppler Duplex system yield functional data in respect of blood flow in addition to the analysis of morphological changes. It is possible to differentiate between cystic structures and collaterals as well as to assess residual perfusions or cavernous transformations in vascular occlusions. Besides qualitative information on blood flow in a vessel and determination of the direction of blood flow, quantitative data on the acceleration of blood flow in stenosis are also possible.

Humans↗
PubMed1985

[Nonvisualization of the gallbladder lumen by sonography].

Out of 12 000 sonographic examinations of the abdomen in 211 cases the gallbladder was not visualized. The retrospective analysis of 41 patients revealed in 75% gallstones, in 15% space occupying lesions (4 carcinomas, 1 abscess, 1 sludge). In 10% the sonography gave a false positive result. The reasons are discussed.

Abscess↗
PubMed1984

[Sonography and scintigraphy in the differential diagnosis of diffuse liver parenchymal diseases].

70 patients with established diffuse liver disease (steatosis, fibrosis, cirrhosis) were investigated by sonography and scintigraphy. Sonographic parenchymal morphology and scintigraphic activity pattern were correlated with the histological diagnosis. Scintigraphy as a functional diagnostic technique revealed early fibrotic changes of the liver not seen by ultrasound. Cirrhosis could be demonstrated equally by both methods. The two major advances of ultrasound were: high accuracy in steatosis and ability of simultaneous analysis of the other abdominal organs.

Celiac Disease↗