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Biomedical subjects

A Kiuru

Publications and source records attributed to A Kiuru.

10 recordsLinked to original sources

Diagnosis of Duchenne and Becker muscular dystrophies by polymerase chain reaction. A multicenter study.

OBJECTIVE--To assess the efficiency, reliability, and ease of use of DNA diagnosis for Duchenne and Becker muscular dystrophies (DMD/BMD) using the polymerase chain reaction (PCR). DESIGN--DNA from the patients was screened for deletion mutations using multiplex PCR, and the results were compared with those obtained by Southern blot analysis. The PCR multiplex reaction detects nine specific "hot-spot" exons in the dystrophin gene while the Southern analysis detects 66 specific dystrophin gene restriction fragments. The multiplex reaction requires 50-fold less DNA than Southern analysis and thus is considerably more sensitive. SETTING--Fourteen university-affiliated and private genetic disease diagnostic laboratories. PATIENTS--Male patients with clinical signs of DMD/BMD. Cases were selected for analysis randomly, without knowledge of whether a deletion was present within the dystrophin gene. MAIN OUTCOME MEASURES--The percentage of cases that were detectable by multiplex PCR in comparison with Southern analysis, the frequency, extent, and location of the detected deletion mutations. In some cases, duplication mutations were monitored. RESULTS--The accuracy of a single PCR multiplex amplification (nine exons) was compared with Southern analysis with 10 cDNA probes that cover the full length of the gene. The multiplex PCR analytic method detected 82% of those deletions detected by Southern analysis methods. In one of 745 analyses, the multiplex method suggested a single exon deletion, which was not confirmed by Southern analysis, representing a false-positive rate of 0.013%. CONCLUSIONS--Multiplex PCR represents a sensitive and accurate method for deletion detection of 46% of all cases of DMD/BMD. The method requires 1 day for analysis, is easy to perform, and does not use radioactive tracers. As such, multiplex PCR represents an efficient and rapid method for prenatal or postnatal diagnosis of DMD/BMD.

Blotting, Southern

User requirements and standards for PACS. 2nd Japan-Nordic PACS Symposium.

PACS has been regarded as a system which will bring a new era to image handling, radiology departments and its services to other departments of the hospital. However, many recently held international conferences indicate that a worldwide consensus on 'what is PACS, why is PACS needed and who is PACS for' has not been established. Although the actual PACS implementation will vary among the countries and according to each situation, a worldwide consensus of PACS should be possible. This would help those involved to speed up the implementation of PACS. It is suggested that this consensus needs to be developed by convergence of three points of view; the availability, maturity and cost of the technologies on which PACS is built, the user requirements for PACS and standardization in PACS. These themes were the topics of the 2nd Japan-Nordic PACS Symposium which was arranged in Tampere, Finland, June 9-11th 1991. A summary of the papers and discussions of the symposium is produced in this paper.

Cost-Benefit Analysis

Information compression in dynamic radiological studies.

The large volumes of digital image data from radiological examinations demand further research and practical solutions in image compression before PACS solutions in large radiological departments are plausible. But another type of compression of image information is also possible, which has, in fact, been somewhat utilized already in analog form, but which has far better possibilities in the digital world. The number of essential images in dynamic X-ray, nuclear medicine, examinations etc. can be greatly reduced. These examinations producing image series are reviewed in terms of compression of information. 3-D displays are very useful in slice imaging, because they provide a means to see easier inside the human body than a number of slice images side by side. We also provide a new method, dynamic pulmonary imaging with digital fluoroscopy, as an example of the digital possibilities to compress a number of images into parametric images, numbers, histograms and curves. These processes also have other positive consequences information is transformed into a more easily perceptible form.

Diagnostic Imaging

Dynamic imaging of pulmonary ventilation. Description of a novel digital fluoroscopic system.

A new fluoroscopic imaging device consisting of an AT-microcomputer and a digital image memory unit has been used in experimental and clinical ventilation studies during a 2-year period. Digital images with 256 shades of gray were collected during one to 3 ventilation cycles at the rate of 6 to 25 images/s and stored on an optical laser disc. Both subtracted time interval difference (TID-) images and images relative, for example, to the mean image of the cycle (REL-images) were produced. The series of images could also be evaluated dynamically using animation sequences or analyzed using region of interest calculations. The method gave dynamic information with adequate spatial resolution and was easy to use in clinical practice. The radiation dose was kept low due to the high kilovoltage and heavy beam filtration technique. In experimental studies the software enabled flexible measurements of physiological pulmonary parameters.

Animals

Dynamic imaging of pulmonary ventilation in children using digital subtraction radiography.

Digital subtraction radiography is a sensitive method for imaging changes in pulmonary aeration during the respiratory cycle. The findings of 75 consecutive dynamic pulmonary examinations performed on 49 pediatric patients using this technique were reviewed together with the findings at chest radiography and, in 18 cases, with bronchoscopy. Symmetric diaphragmatic movement and synchronous, homogeneous variation in the attenuation of lung parenchyma indicated normal conditions in 9 (18%) patients. The most common abnormal finding (36 patients) was an asynchronous variation in the attenuation of the lung parenchyma. A greatly diminished or absent variation in attenuation was diagnostic for a serious air passage obstruction in 7 children. Other abnormal findings were a lowered amplitude of diaphragmatic movement, asynchronous diaphragmatic movement and mediastinal shift. In 10 patients (20%) the dynamic study showed parenchymal abnormalities when chest radiography was normal. Bronchoscopy was performed in 4 of these 10 patients and showed abnormalities in each case.

Adolescent

Use of a generalized modular data handling system in nuclear medicine.

Addition of a CAMAC modular data handling system to a small computer used for gamma-camera work has allowed the acquisition and processing of a broad variety of nuclear medicine data. Significant contributions have been made ranging from clinical renal evaluation to radiopharmaceutical development. Digital rectilinear scanning and computer acquisition of physiological signals such as the electrocardiogram are other applications. The system provides an inexpensive means of matching present-day nuclear computers to the diversity of data.

Computers

Finnish PACS project.

A Finnish PACS project has been set up with the participation and financing of 13 university and central hospitals, the Medical Board of Finland, the Hospital League of Finland, the Post and Teleoffice of Finland and the Helsinki Telephone Company with the Medical Engineering Laboratory of the Technical Research Centre of Finland as the principal investigator. The project started in December 1988 and ended in December 1990. The project focused on the functional needs for PACS. The image production, archive sizes, network capacity and workstation requirements have been studied in a big university hospital. The results show that without compression the image archive size needs to be at least 10 TB. The network capacity requirement depends very much on the interactivity requirements. In normal situations less than 1 Mbit/s is needed, if the network is configured in an efficient way. In some cases, however, the speed requirement can be of the order of 100 Mbit/s. A proposal for a hospital-wide PACS network was made. Simple calculation rules to estimate the needed capacities were also developed.

Computer Systems

Dynamic pulmonary imaging: performance properties of a digital fluoroscopy system.

The physical characteristics of dynamic pulmonary imaging with digital fluoroscopy, which differ from those in DSA equipment, have been determined. The spectral distributions and mean energies were calculated and corresponding exposures with varying high voltage and copper filtration (60-100 kVp, 0-2.83 mm Cu) were measured. The utilization of 90-100 kVp with a filter consisting of 1.39 mm Cu and 3 mm Al minimized disturbing skeletal artifacts and reduced the radiation exposure by a factor of approximately 5 in comparison with imaging at 60 kVp without copper filtration. Simultaneously, the measured signal decreased by about 25%. The mean energy of this spectrum exceeded that of 140 kVp chest imaging. The dynamic pulmonary imaging method produces logarithmically transformed x-ray transmittance values linearly related (r = -0.999) to water thickness between 7-10.5 cm, which is equivalent to the normal range of the chest in pediatric patients. A good linear correlation (r = 0.933,N = 92) was obtained when the change in transmitted radiation was compared with tidal volume measured in a rabbit model using a pneumotachometer. The results indicate that the method is applicable for quantitative measurements of pulmonary ventilation. Changes in tidal ventilation can be measured with this noninvasive x-ray imaging technique.

Animals

PACS in Japan and the Nordic Countries. First Japan-Nordic PACS symposium.

The ingredients seem to exist for switching from film-based radiology to digital radiology utilizing the concept Picture Archiving and Communication System (PACS). Why has this not happened? What are the barriers limiting the diffusion of PACS into health care? This was the theme of the 1st Japan-Nordic Symposium in PACS, which was held in Tokyo, March 29-30, 1990. Over 40 radiologists and technical specialists in PACS participated. The topics discussed ranged from the present status of PACS in Japan and the Nordic Countries, to functional specifications and user requirements for PACS, to organizational and other changes brought about by PACS and to teleradiology as a solution for communication of images over wide distances. The symposium was quite successful and will be followed by a 2nd symposium in Finland in the summer of 1991.

Humans