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Biomedical subjects

R Rienmüller

Publications and source records attributed to R Rienmüller.

At least 37 records · Page 2Linked to original sources
PubMed1990

The influence of rejection episodes on the development of coronary artery disease after heart transplantation.

Since 1981, 77 of 116 patients undergoing heart transplantation (HTx) have survived from 6 months to 8 years. Graft control involved a total of 871 endomyocardial biopsies (EMB) and 141 angiographies. Sixteen patients developed coronary artery disease (CAD) manifesting itself 7-60 months after HTx (20.7%). These patients (15 male, 1 female) experienced multiple rejection episodes (RE) and more than half suffered from hypercholesterolaemia and hypertension (n = 10). A mean rejection score (Billingham grading) of greater than 1 (mean = 1.6 +/- 1.1) was calculated in all patients with CAD at the time of angiography or autopsy. By contrast, the mean rejection score ranked less than 1 in patients with undetectable or resolved CAD (means = 0.4 +/- 0.38). This rate is not remarkably different from the rejection score in patients (n = 61) without CAD (mean = 0.2 +/- 0.4). The 8 patients alive (56 +/- 18 months) showed a low number of RE/year (mean = 1.1 +/- 0.4) compared with means = 1 +/- 0.9 in patients without CAD. Eight patients expired within a short period (mean = 31 +/- 26.9) and had a significantly higher number of RE/year (mean = 4.3 +/- 2.9; P less than 0.01 vs. no CAD, CAD alive). Autopsy (n = 6) and angiographic studies (n = 46) demonstrated diffuse, concentric, obliterative arterial disease in all vessels (type A) in 6 patients (RE/yr: mean = +/- 5.5 +/- 2.3), single stenoses in major coronary vessels (type B) in 7 patients and ordinary atherosclerosis (3-vessel disease) comparable to ischaemic heart disease (type C) in 3 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
PubMed1990

MR and CT for detection of cardiac tumors.

Although echocardiography is mostly applied for the diagnosis of heart tumors there are restrictions concerning the representation of the mediastinal and cardial topography in spite of the usage of transoesophageal echocardiography. Computed tomography (CT) and magnetic resonance imaging (MR) are able to give a full representation of the heart and also the thorax with mediastinum, pleura, and lungs. Not only for the diagnosis of various kinds of heart tumors but also for decisions concerning the therapy, the detection of postoperative complications and development are CT and MR very valuable procedures. The ability to deliver a complete cross-section of all cardial, mediastinal, pulmonal and thoracic structures--in contrast to angiocardiography--and without any anatomic restrictions in contrast to echocardiography--is another advantage of CT and MR. Because of the fullness of information CT and MR supply these procedures are especially used for the detailed planning of operative procedures. They are also a big help in determining whether surgery might have to be excluded because a complete tumor resection is not possible anymore.

Female↗
PubMed1990

Measurement of pulmonary parenchymal attenuation: use of spirometric gating with quantitative CT.

A new approach to reproducible measurement of lung attenuation and structure by means of respiratory-gated computed tomography (CT) was developed. The patient breathes through a microcomputer-controlled pocket spirometer during the complete CT examination, starting with a measurement of the vital capacity. At a user-selected respiratory level, the CT scan is triggered and air flow is inhibited mechanically. To exclude operator-related reproducibility errors, evaluation is based on semiautomated algorithms that isolate lung parenchyma by fast contour tracing. In a study on one volunteer, measurement of lung attenuation changed by a factor of about 2.6 (-895 to -730 HU) as a function of inspirational status. Reproducibility on the order of 5% or better can be achieved only with tight spirometric control of respiration.

Humans↗
PubMed1989

[The chambers of the bovine uterus during early pregnancy. A comparative morphologic, sonographic and nuclear spin tomographic findings].

In the bovine, the uterus shows prominent circular folds during early pregnancy. These folds protrude into the lumen nearly at right angles to the uterine wall and, reaching a height of about 2-3 cm in some cases, often reach the center of the uterine lumen. Thus the uterus becomes apparently divided into a number of pocket-like chambers. Endometrial folds are usually found in the pregnant as well as the contralateral uterine horn. Intra-uterine features can be well demonstrated on exenterated bovine uteri without injuring the organ by means of nuclear magnetic resonance imaging with a high resolution performance. This technique was used to examine the uteri of 4 heifers on day 26, 28, 32 and 55 of pregnancy, respectively. The 3-dimensional imaging of these uteri demonstrated the presence of crescent-shaped folds usually at right angles to the long axis of the uterine horn. These endometrial folds explain why the allantochorionic vesicle cannot be demonstrated in toto by transrectal sonography during early pregnancy, apparently being subdivided by the protrusions from the uterine wall. It has been found that the uterus is characterized by 2-3 echo-weak compartments around day 25 of pregnancy and by about 4-6 by day 30. The number may yet increase with progressing pregnancy. Histological sections out of the wall of the pregnant and the contralateral uterine horn have revealed that the folds are composed mainly of the endometrium (Tunica mucosa) and the circular muscle (Stratum circulare).

Animals↗
PubMed1988

Non-cardiogenic pulmonary edema complicating intermediate and high-dose Ara C treatment for relapsed acute leukemia.

Infection, hemorrhage and adult respiratory distress syndrome (ARDS) are pulmonary complications occurring after remission induction therapy for acute leukemia. The aim of this study was to analyze the incidence of these causes by serial roentgenogram, clinical, microbiological and laboratory tests in 21 patients (pts) with relapsed acute leukemia (18 X myeloid, 3 X lymphoblastic), an AML-pt (acute myeloid leukemia) suffering from secondary leukemia, and three pts with primary refractory leukemia following treatment with intermediate (IM) and high-dose cytosine arabinoside (HD-Ara C), in combination with amsacrine (AMSA)(n = 19), etoposide (VP 16) (n = 5) or Mitoxantrone (n = 1). Eleven out of 25 pts developed pulmonary complications, one of them with massive hemoptysis and roentgenographic signs of pulmonary bleeding, one suffering from protracted shock after a tumor lysis syndrome, two pts showing symptoms of a cardiogenic pulmonary edema complicating severe Candida pneumonia in one case and legionnaires' disease in the other. Seven of the eleven pts had a non-cardiogenic pulmonary edema with respiratory failure 1-14 days after cessation of induction or consolidation therapy. In six of the seven, there were no signs of cardiogenic, infectious or metabolic reasons, including fluid overload, for the pulmonary edema, one had as a contributing factor a Candida infection of the lung. Three of the seven patients recovered, four died (two following IM and two after HD-Ara C). Other adverse side effects, clearly attributable to HD-Ara C, included delirious state (n = 3), generalized erythema (n = 3), acute pancreatitis (n = 2), acute abdomen (n = 1) and conjunctivitis in almost all patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1988

[Quantitative CT studies of the lung in an animal experiment model of silicosis].

High resolution, narrow section CT examinations of the lungs were carried out on 21 Javanese macaques (five controls) shortly before the conclusion of 27 months exposure to quartz and/or high pressure. The aim was to establish morphometric CT data for differentiating and quantifying normal and abnormal findings. The results show that the technique has a high sensitivity for demonstrating the pathological lung changes. Final validation depends upon the use of respiratory physiology and biochemical, cytological, and histomorphometric data.

Animals↗
PubMed1988

[DS-1000--a new digital image intensifier film-screen system in thoracic diagnosis].

The characteristics of the DS-1000, a new digital imaging equipment, using an image-intensifier-video-system are described. The digital images are displayed on a monitor with 1024 x 1024 matrix, are stored on a hard disc and can be postprocessed with regard to gray-scale-level and recognition of details. The spatial resolution ist 1,1 Lp/mm, using the 47-cm-image-intensifier. The DS 1000 was employed for chest-examinations. The diagnostic accuracy of 70 selected cases with a great variety of pathologic conditions was verified in comparison to conventional chest films. There was no significant difference in the recognition of normal anatomic structures between the two imaging systems. Pathologic states with low contrast to the surrounding structures (mediastinal and hilar masses, airspace disease, pulmonary nodules) were displayed at least equivalent with the digital technique. The accuracy in recognizing pathologic states with the digital equipment as compared to the conventional technique was inferior for conditions requiring high spatial resolution (subtle interstitial infiltrations, septal lines, scars, subtle calcifications).

Diagnosis, Differential↗
PubMed1986

[Gd-DTPA in magnetic resonance diagnosis of chronic myocardial infarct].

30 patients with myocardial infarction older than three weeks were examined by MRI prior and following intravenous injection of 0.1-0.2 mmol/kg Gd-DTPA, 201TL-SPECT and cineventriculography. Gd-DTPA did not cause any significant change (p less than 0.05) of T2-values for infarcted or non-infarcted myocardium. Compared with this, signal intensity for T1-weighted images increased after the application of the contrast agent both for normal (26 +/- 14%) and infarcted myocardium (33 +/- 16%). The intraindividual signal intensity ratio for infarcted and normal myocardium increased from 1.06 +/- 0.07 to 1.12 +/- 0.09 after the injection of Gd-DTPA. The diagnosis of myocardial infarction by visual analysis of signal intensity was not possible in individual cases. Myocardial infarction could only be visualized indirectly by morphological changes such as wall thinning and aneurysm.

Adult↗
PubMed1985

Constrictive pericardial disease: prognostic significance of a nonvisualized left ventricular wall.

Twenty-six patients with pericardial constriction confirmed by catheterization were studied by dynamic computed tomography (CT). The posterolateral wall of the left ventricular myocardium was not detected in five patients (19.2%). None had evidence of previous myocardial infarction on electrocardiogram or levocardiogram. In 16 patients, a pericardiectomy was performed to remove pericardial constriction. All five patients with nondetectable posterolateral walls of the left ventricle died at or immediately following surgery because of acute myocardial failure. Nonvisualization of the posterolateral wall of the left ventricle in patients with constrictive pericarditis suggests the presence of myocardial fibrosis or atrophy. Surgery is an extremely high risk in these patients.

Adult↗
PubMed1985

[Digital radiography--methods and clinical application].

The term "Digital Radiography" covers all x-ray techniques which produce a projected image with the help of digital imaging techniques, which are very similar to a conventional x-ray film image. The advantage of "Digital Radiography" is the possibility of digital image processing, like the subtraction technique, the selective material filtering technique and the quantitative image plotting technique. With the equipments now in use, the digital projected image is produced by the line or on an even level. One example of the in-line projected image is the so-called "topogram", produced via computed tomography equipment. With the help of an x-ray video chain, it is possible to produce digital images on an even level. This technique is used, for example, for "digital video subtraction angiography" (DVSA). Today, digital radiography is clinically used only in the "DVSA" and the "topogram" systems. A survey of the clinical use and the improved future possibilities of digital radiography is given, and the special features of the method are discussed.

Analog-Digital Conversion↗