Biomedical subjects

B Wein

Publications and source records attributed to B Wein.

48 records · Page 3Linked to original sources

PubMed1989

[Digital radiography: a new approach in roentgen diagnosis].

Digital electronics now play a role in every branch of diagnostic imaging. One of the most recent methods, digital radiography (DR) makes it possible to store and view radiographs in the form of a matrix of discrete values. The present review describes the components needed for DR imaging and archiving as well as the advantages and disadvantages of the system. The use of storage phosphor is hereby of special interest. By enableing the viewer to process the images, it is hoped that DR will open up new possibilities for projection radiography and strengthen its position as a routine method in comparison to other digital imaging systems, e.g. CT. It remains to be seen whether or not DR, as an isolated system, will be widely used. But in any case it represents the missing link in the chain of digital imaging methods and opens new ways of imaging archiving and administration.

Bone Diseases↗

PubMed1989

[Ultrasound sonography of active and passive tongue motility].

Applying both B- and M-mode sonography, we examined tongue movements during swallowing, during repetitions of identical and changing syllables and during continuous articulation of voiced apical /r/. A pseudo-three-dimensional reconstruction was developed for tongue movements registered in B-mode. Our approach can be easily applied for the evaluation of impaired tongue motility in speech pathology.

Adult↗

PubMed1988

[Computerized sonographic imaging of tongue motility using pseudo-3 dimensional reconstruction].

A new method for analysis and documentation of tongue movements was used in 24 healthy volunteers. This method enables direct digitalization of the information obtained from sequences of B-Mode pictures. Besides of allowing to further digital evaluation of the findings, it offers the facility of "pseudo 3D"-reconstruction of the tongue movements occurring on swallowing. The method appears to be of particular value for therapy control in neurological and phoniatric patients.

Deglutition↗

PubMed1988

[Ultrasonic diagnosis of the pseudoglottis in laryngectomized patients].

The validity of ultrasonic imaging as a tool for the investigation of pseudoglottal movements was studied in five good to excellent esophageal speakers. The length of pseudoglottis and vibration rate during phonation of vowels was evaluated by means of B-mode and M-mode sonography respectively. The pseudoglottal vibration rate as seen in M-mode sonography was in high agreement with the fundamental frequency of the simultaneously recorded sound as assessed by speech analysis. Ultrasound imaging is a promising diagnostic and therapeutic tool for the control and development of esophageal speech.

Aged↗

PubMed1988

[Ultrasound study of disorders of coordination in tongue movement in swallowing].

Ultrasound imaging of tongue movements permits real-time observation of swallowing and articulation without risk for the patient. The ultrasound images of the tongue motions were recorded on video-tape and then analyzed frame by frame. We were able to detect regular phases of tongue motion during normal swallowing. Clear deviations from normal motion patterns were found in a patient with anarthria, despite absence of swallowing difficulties in every day life.

Adult↗

PubMed1985

Characteristics of lactate transfer in isolated cardiac myocytes.

L-lactate uptake of isolated cardiac myocytes was investigated, since due to different lactate concentrations in the interstitial fluid and vascular space, lactate uptake cannot be studied satisfactorily in whole hearts. Lactate uptake exhibits sigmoidal saturation kinetics. Pyruvate (2.3 mM) inhibits L-lactate uptake at lower lactate concentrations (less than 15 mM) and enhances L-lactate uptake at higher (greater than 25 mM) lactate concentration. L-lactate uptake is increased at lowered pH (7.1) to an extent not explainable by non-ionic diffusion. The results are discussed in terms of a complex L-lactate carrier system which might involve cooperative mechanisms and H+-co- or OH- -countertransport.

Animals↗

PubMed1985

Barriers in cardiac substrate supply.

The capillary wall, due to its diffusional resistance, causes concentration differences between the vascular space and the interstitial space for substances which are released or taken up by the heart. Estimation of capillary transfer and interstitial concentration in isolated hearts, however, indicates a variable diffusional resistance, which in the case of glucose results from an insulin dependent transfer mechanism and in the case of lactate from a dependence of lactate transfer on lactate concentration or direction of transfer. Due to the unpredictable interstitial concentration investigation of sarcolemmal transfer appears to be possible at present only with isolated cardiac myocytes. Sarcolemmal transfer was studied for glucose and lactate. Recent investigations of lactate transfer revealed saturation kinetics, dependence on pyruvate (inhibition at low lactate concentration and enhancement at high lactate concentration) and dependence on pH (linear increase with lowered pH [8.0 to 6.7]).

Animals↗

PubMedDate not supplied

Gadolinium-enhanced T1-weighted versus T2-weighted imaging of scrotal disorders: is there an indication for MR imaging?

To evaluate the use of gadopentetate dimeglumine in magnetic resonance (MR) imaging of scrotal disorders, the clinical, ultrasound, and MR imaging data of 29 patients (age range, 19-75 years) with various intra- and extratesticular disorders were retrospectively analyzed. T1- and T2-weighted spin-echo images (T1-T2 group) were compared with T1-weighted spin-echo images before and after intravenous administration of gadopentetate dimeglumine (T1-Gd group). A receiver operating characteristic (ROC) analysis of the findings was undertaken. Better contrast between tumor and parenchyma and a clearer demonstration of the tunica albuginea were noted in the T1-T2 group (although not of diagnostic relevance). ROC analysis revealed no differences between the two imaging groups in the diagnosis of tumor, trauma, hydrocele, or hemorrhage; however, epididymitis was diagnosed more easily with contrast enhancement (0.8834 vs 0.7759, P = .04) and the diagnosis of orchitis was expressed more strongly (0.8221 vs 0.7184, P = .17). Four of the five observers were more confident in making the diagnosis with contrast enhancement. With MR imaging, the diagnosis was correctly suggested in three patients in whom clinical and ultrasound data were inconclusive. Gadolinium-enhanced MR imaging gives additional information in scrotal disorders and facilitates diagnosis. It may be helpful when findings at physical examination and ultrasound differ and when plain T1- and T2-weighted images are equivocal.

Adult↗

PubMedDate not supplied

[Tongue ultrasound and pressure measurement in infantile sucking. Initial results].

The sucking procedure was examined in 10 healthy, term infants and in one newborn with disturbed sucking actions suffering from recurrent aspiration pneumonia. We applied ultrasonography of the tongue and simultaneous intraoral pressure measurements in the examinations. Observations were made with a bottle feeding system (NUK). Sonography and intraoral measurements both gave reliable informations. Parallel recordings of tongue dorsum movements by pseudo-3-dimensional imaging and simultaneously obtained pressure curves show, that increasing suction is maintained by withdrawing the tongue dorso-cranially. Computer-aided evaluation of ultrasound images and pressure data demonstrate the possibility to distinguish between coordinated and uncoordinated sucking movements. Simultaneous use of both examination techniques can be helpful in diagnosis and documentation of disturbed sucking actions.

Female↗

PubMedDate not supplied

Circular spirit level guidance system for CT- and MR-guided punctures.

A circular spirit level guidance system was tested for control of CT- and MR-guided punctures. The device consists of a needle holder fixed to a ground plate and two protractors. This allows adjustment of the fixed needle according to the angulation of the supposed puncture path as measured on tomographic images. A circular spirit level is fixed to the needle and leveled. Now the needle can be removed from the needle holder; by leveling the circular spirit level during the puncture, the formerly adjusted angulation is achieved. The system was tested in vitro and in vivo (22 patients) under CT and MR guidance. The average needle deviation was measured to be 1.96 degrees in vitro and 2.51 degrees in vivo. This simple device allows accurate puncture under CT and MR guidance.

Humans↗

PubMedDate not supplied

PACER: a software tool for PACS decision makers.

This paper describes the development of the software package PACER as it evolved from a cost model to a software package for PACS decision making. PACER was developed as part of the TEASS topic from the EurIPACS project. EurIPACS is an EU subsidized project covering a wide area of PACS related research. The TEASS topic concerns the evaluation of prototype PACSystems in three European hospitals. PACER allows the user to evaluate costs of various PACS implementation scenarios and compare them to the costs of the current film based situation. Its cost calculation is based on a straight forward description of costs of a film based radiology department and of PACS. The PACER cost analysis can consider stepwise introduction of PACS and a corresponding stepwise disappearance of the film environment. This analysis includes effects of price developments. PACER calculates costs and expenses for a number of years in succession. The calculated results can be analysed using graphs, tables and sensitivity analysis tools. Preliminary tests in three hospitals indicate that PACER can indeed be a useful tool in the decision process concerning PACS.

Costs and Cost Analysis↗

PubMedDate not supplied

Mobile radiography CQI: an inter-national study.

Mobile or bedside radiography has been and is a staple diagnostic and follow-up tool used readily by the many medical disciplines, such as cardiology, surgery, orthopedics, pediatrics, neonatology, etc. Ironically, in the past a student or the least qualified technologist was sent to perform the bedside exam. Moreover, it was almost expected that poor but acceptable film quality would result or that repeat films were almost always to be taken. Inefficiency with respect to quality of exam, the time the exam takes, or film repeats can be costly. The price of inefficiency is the cost involved in doing things incorrectly or not in the most efficient manner, i.e., incurring inefficiencies instead of operating in an ideal manner. The purpose of this study was to compare the total cost of inefficiently organized, scheduled and performed mobile radiography at three large teaching hospitals in various locations and of diverse patient loads, as a means of determining how best to increase utilization and performance. The study was performed at the 489-bed New England Deaconess Hospital (NEDH), the 644-bed Sentara Norfolk General Hospital (SNGH), and the 1500-bed Rheinische Westfalische Technische Hochschule (RWTH) in Aachen, Germany. Similar standardized study methods were utilized at all three institutions where extended observation of mobile utilization, areas of inefficiency, time wasted per episode and number of episodes per time period were determined. Data were loggedin at three standardized time periods, summated, and then multiplied by technologist hourly pay rate. This sum was extrapolated over 52 weeks to give the total annual cost of inefficiently organized mobile radiography. For NEDH the cost of total inefficiency was $75,453, for SNGH $49,586, while for RWTH it was $9,519. Eighteen areas of inefficiency were identified and grouped, such as lack of spatial cohesiveness and lack of communication leading to film duplication, etc. While inefficiencies in the delivery of hospital based health care are well known, this study attempts to quantify and determine a dollar value for each process found as inefficient. Key inefficiencies were found to be common at large hospitals no matter whether in the United States or Europe. These impairments are responsible for a disproportionate share of overall inefficiency, and their elimination (achievable by simple solutions) would result in drastic cost reductions (ranging from 40-75% at the institutions studied). Thus this study is important in view of spiralling costs, as it is a key component of total quality management (TQM) in radiology and a continuous quality improvement (CQI) tool for mobile radiology specifically.

Efficiency, Organizational↗