PubMed HealthSearch

Biomedical subjects

R Rienmüller

Publications and source records attributed to R Rienmüller.

At least 19 recordsLinked to original sources

[Functional studies of swallowing with electron beam computerized tomography].

Functional evaluation of swallowing disorders requires rapid imaging modalities. Videofluorography and cinematography are the gold standard, but they have their limitations: no transverse plane imaging is achieved and structural resolution for exact topographic analysis is limited. Three cases preselected by videofluorography were studied to evaluate whether electron beam tomography (EBT) permits more detailed dynamic imaging of swallowing disorders focusing on the mesonasopharyngeal segment, the hypopharynx and the upper esophageal sphincter (UES). Immediately after videofluorographic examination of the oropharyngeal deglutition, EBT is performed. The patient is in a supine position and while the patient swallows a 20 ml bolus of water or diluted iodine containing contrast agent, a sequence of 20 images per level is scanned. The levels, which are determined by using the scout view, are oriented parallel to the hard palate either at the level of the hard palate to image the mesonasopharyngeal segment or just above the hyoid bone to focus on the hypopharynx or at the location of the UES. The scan technique is a single-slice cinemode with a slice thickness of 3 mm (exposure time 100 ms, interscan delay 16 ms, 130 kV, 620 mA). The following structural interactions that we have so far been unable to image can be clearly demonstrated with EBT: (1) during normal swallowing, the mesonasopharyngeal segment is completely and symmetrically closed by the soft palate and Passavant's cushion; (2) lateral hypopharyngeal pouches can be located more precisely; and (3) disorders of the UES can be differentiated into functional or morphologically caused disorders (e.g., goiter or cervical osetophytes). Videofluorography and cinematography are still the gold standard in functional evaluation of swallowing disorders. However, EBT permits dynamic imaging of pharyngeal deglutition in a preselected transverse plane and can give useful additional information concerning functional anatomical changes in the pharynx during swallowing. Further clinical evaluation is needed.

Adult

Short-term and long-term effects of serial bronchoalveolar lavages in a nonhuman primate model.

Bronchoalveolar lavage (BAL) has gained widespread use as a tool for investigating human lung diseases. In certain cases, it can be useful to obtain BAL material in a serial manner. There is convincing evidence from experimental and clinical studies that BAL can cause influx of neutrophils into the bronchoalveolar space. However, conflicting data have been reported on whether this side effect of BAL also affects previously nonlavaged lung areas. In addition, there is little information available on whether multiple repetitive BAL procedures cause damage to lung tissue. To reexamine the short-term effects of serial BAL procedures, the left lung of 10 cynomolgus monkeys was lavaged with five 20-ml aliquots of saline four times at 24-h intervals (Group A). 72 h after the initial BAL, the right lung was lavaged as a control. The percentage of neutrophils increased significantly (p < 0.05), with the greatest effect seen at 48 h (30.7 +/- 5.8 versus 0.8 +/- 0.3%, mean +/- SEM). No significant changes were observed in the control BAL of the right lung at 72 h. A multidisciplinary approach was used to assess the long-term effects of multiple BAL procedures. BAL was performed 14 times over 26 mo at 2-mo intervals (Group B, n = 5). The right lung was lavaged as a control 25 mo after the initial BAL. In addition to standard cellular BAL parameters, the concentrations of fibronectin, procollagen III amino-terminal peptide-related antigen, total phospholipids, and lactate dehydrogenase activity were measured.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

[Successful treatment of atrial fibrillation by resection of a congenital aneurysm of the left heart atrium].

Atrial fibrillation occurred in a 27-year-old patient with a history of globular cardiac enlargement since childhood. Because of the probable causal relationship between the preexisting heart disease-which was supposed to be an enlargement of the left atrium-and the rhythm disturbance, we recommended a surgical intervention. Cardiac surgery revealed a congenital aneurysm of the left atrial appendage which could be resected without any complication. Postoperatively, atrial fibrillation had returned to regular sinus rhythm. The bad prognosis with a high risk of systemic embolism is the reason why early cardiac surgery should be performed after diagnosis of this rare anomaly (20 reported cases) of the left atrium.

Adult

[The present status of MR cardiac diagnosis].

The spectrum of diagnostic procedures in cardiology has been decisively extended by magnetic resonance (and also by ultrafast computed tomography) because of its superior visualization of morphological (myocardium, pericardium) and functional (LVMM/EDV) parameters. The continuous development of faster echo sequences makes it possible to perform heart studies over a shorter time and to reduce the frequency of movement and ECG-induced image artefacts. This means that magnetic resonance studies will be simplified, the image quality will be improved, and therefore the numbers of heart studies can be expected to increase. With respect to the range of diagnostic procedures available, magnetic resonance can be seen between echocardiography and heart catheter studies. Coronary angiography cannot be replaced at this time. The true potential of magnetic resonance (and also of ultrafast computed tomography), however, cannot be exploited without evaluation of the prognostic parameters that determine the form and the optimal timing for a conservative and/or surgical treatment of defined cardiac diseases. Therefore, systematic interdisciplinary studies are necessary.

Echocardiography

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

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

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

[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

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

[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