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Biomedical subjects

S M Giacomuzzi

Publications and source records attributed to S M Giacomuzzi.

13 recordsLinked to original sources
PubMed1998

[ACOnet (Austrian Academic Computer Network) as data carrier for teleradiologic consultations].

PURPOSE: To assess the feasibility of image transfer for teleradiologic consultations using the Austrian Academic Computer Network (ACOnet). The ACOnet corresponds between the main universities to a MAN (Metropolitan Area Network) with a transfer rate of 4 Mbps. Its use is free of charge for university institutions. MATERIALS AND METHODS: 1740 test image data sets and 620 image data sets for teleradiological consultations were exchanged without annotations between the Departments of Diagnostic Radiology of the universities of Innsbruck and Graz, using the ACOnet. RESULTS: Data transmission was reliable and fast with an average transfer capacity of 170.2 kBytes/s (94-341 kBytes/s). There were no major problems with image transfer during the test phase. CONCLUSION: Due to its high transfer capacity, the ACOnet is considered a reasonable alternative to the ISDN service.

Austria↗
PubMed1998

The Austrian Academic Computer Network and its usefulness for teleradiology.

To study the value of the Austrian Academic Computer Network (ACOnet) for teleradiology, 1740 test image data-sets and 620 image data-sets were exchanged between the departments of diagnostic radiology of the Universities of Innsbruck and Graz using the ACOnet service. Data transmission was reliable and fast with an average transfer capacity of 170 kByte/s (range 94-341). During the test phase, no major problems with image transfer occurred. Assuming that problems like security of patient data-sets, data compression and data verification can be solved, the ACOnet service would be a useful additional tool for telemedicine applications throughout Austria and eastern Europe.

Austria↗
PubMed1997

Virtual computed tomography gastroscopy: a new technique.

BACKGROUND AND STUDY AIMS: The aim of the present study was to establish a suitable method for virtual computed tomography (CT) gastroscopy. PATIENTS AND METHODS: Three-millimeter helical CT scans of a pig stomach were obtained after air insufflation and instillation of diluted diatrizoic acid (Gastrografin), and with double contrast. In addition, three patients with gastric tumors were studied after ingestion of an effervescent agent (Duplotrast, 6 g) and intravenous injection of hyoscine butylbromide (Buscopan, 1 ml). Virtual endoscopy images were computed on a Sun Sparc 20 workstation (128 megabytes of random access memory, four gigabytes of hard disk space), using dedicated software (Navigator, General Electric Medical System Company). The endoscopy sequences were compared with real endoscopic examinations and with anatomical specimens. RESULTS: In the cadaver studies, the best results were obtained with plain air insufflation, whereas virtual CT gastroscopy with diluted contrast and with double contrast showed artifacts simulating polyps, erosions, and flat ulcers. Patient studies showed good correlation with the fiberoptic endoscopy findings, although large amounts of retained gastric fluid substantially reduced the quality of the surface reconstruction. CONCLUSION: These preliminary results show that virtual CT gastroscopy is able to provide insights into the upper gastrointestinal tract similar to those of fiberoptic endoscopy. However, due to the limited spatial resolution of the CT protocol used, as well as inherent image artifacts associated with the Navigator program's reconstruction algorithm, the form of virtual CT gastroscopy studied was not capable of competing with the imaging quality provided by fiberoptic gastroscopy.

Animals↗
PubMed1997

A cost analysis of an emergency computerized tomography teleradiology system.

We carried out a cost analysis of a teleradiology system for emergency computerized tomography (CT) examinations. Teleradiology was implemented by connecting two spiral CT scanners in the University Hospital in Innsbruck and the Regional Hospital in Zwettl. It enabled the remote hospital in Zwettl to get fast and competent reports of emergency CT examinations when there was no specialist radiologist available. In 13 months' use for routine night and weekend service, the system proved fast and reliable. During the study period 121 emergency examinations of 116 patients were transmitted from Zwettl to Innsbruck. The fixed costs of teleradiology were for the ISDN connection and amounted to DM230 plus DM696/year rental. The average cost of one emergency CT examination by teleradiology was DM372 (range 308-453). One possible alternative, transporting the films by taxi for reporting elsewhere, was cheaper (estimated cost DM156), but would have been much slower. Another alternative, transporting the patient to the nearest central hospital for scanning, was much more expensive: DM524 by road or DM4667 by helicopter ambulance.

Austria↗
PubMed1997

[Virtual endoscopy with post-processing helical CT data sets].

PURPOSE: The purpose of this work was to test a newly developed, post-processing software for virtual CT endoscopic methods. Virtual endoscopic images were generated from helical CT data sets in the region of the shoulder joint (n = 2), the tracheobronchial system (n = 3), the nasal sinuses (n = 2), the colon (n = 2), and the common carotid artery n = 1). Software developed specifically for virtual endoscopy ("Navigator") was used which, after a previous threshold value selection, makes the reconstruction of internal body surfaces possible by an automatic segmentation process. We have evaluated the usage of the software, the reconstruction time for individual images and sequences of images as well as the quality of the reconstruction. All pathological findings of the virtual endoscopy were confirmed by surgery. RESULTS: The post-processing program is easy to use and provides virtual endoscopic images within 50 seconds. Depending of the extent of the data set, virtual tracheobronchoscopy as a cine loop sequence required about 15 minutes. Through use of the threshold value-dependent surface reconstruction the demands on the computer configuration are limited; however, this also created quality problems in image calculation as a consequence of the accompanying loss of data. CONCLUSIONS: The Navigator software enables the calculation of virtual endoscopic models with only moderate demands on the hardware.

Artifacts↗
PubMed1997

[Open questions on the topic of teleradiology from the current viewpoint].

A review on the theoretical challenges and potential risks of teleradiology is given. Based on the authors two years clinical experience and the current literature unsolved problems are discussed, which are to a smaller extent the technical implementation but much more the still missing regulation of various concomitant circumstances.

Computer Security↗
PubMed1997

[Virtual CT colonoscopy. Examination technique, limitations and perspectives].

Virtual CT-colonoscopy is a post-processing method which allows for reconstruction of inner bowel surface structures from helical CT datasets. The reconstructed images simulate the views which are known from fiberoptic endoscopy. Since colorectal cancer is the second main cause of death in USA and Europe today and since recent screening recommendations are often ignored by the public, a non-invasive or minimal-invasive procedure for colonic evaluation would offer some benefits. Virtual CT-colonoscopy generally involves three essential steps: patient preparation with cleansing of the bowel and administration of an air enema, helical CT-examination by using appropriate scan parameters, and interactive 3D rendering of the volume data-set. Although recent studies have demonstrated that polypoid lesions of about 5 mm size are well detectable and although virtual colonoscopy offers many advantages over fiberoptic endoscopy, some technical and clinical limitations must still be noted. Thus, the current inability of virtual colonoscopy to provide texture and color leads to problems in identifying flat lesions; the presence of retained or adherent fecal matter may result to false positive diagnosis and collapsed segments of bowel may cause problems as they cannot subsequently be evaluated during image reconstruction. Virtual endoscopy is still in its infancy and further technical and clinical developments are necessary. Virtual CT-colonoscopy may then prove to be equal or superior to colonoscopy in sensitivity and specificity for polyp detection and be able to reduce the number of unnecessary colonoscopic procedures.

Colonoscopes↗
PubMed1996

[The smart-scan procedure of spiral computed tomography. A new method for dose reduction].

PURPOSE: In this article a new method - the Smart-Scan-Technique - for dose reduction during spiral computed tomography is described. This technique allows a dynamical adaptation of the tube current according to the measured local density structure form and absorption values of the object of interest. Its clinical applicability for dose reduction is investigated. In addition, changes in image quality are evaluated. METHODS: Specially designed, water filled plexiglas-phantoms, an Alderson-Rando phantom, and 20 patients were used to simulate possible measures of patients within the thoracic and abdominal region. For those two regions the dose reduction, the modulation transfer function, and the pixel noise were measured. RESULTS: Depending on patient geometry dose reduction up to 20% could be achieved with the Smart-Scan-Technique. This technique also enabled a decrease of the modulation transfer function and an increase of the pixel noise by 8%. CONCLUSION: Relevant dose reductions can be achieved by applying the Smart-Scan-Technique in spiral computed tomography.

Absorption↗
PubMed1996

[Establishment of an emergency CT service by means of teleradiology].

UNLABELLED: The teleradiological connection between the University Hospital in Innsbruck, Tyrol, and the Regional Hospital in Zwettl, Lower Austria, is presented as an example of a routine online connection of two helical CT systems. PURPOSE: To establish a practicable and cost-efficient emergency CT service in a remote hospital during night time and on weekends. MATERIAL AND METHODS: Online connection of a GE HiSpeed Advantage-Spiral-CT and a GE Prospeed-Spiral-CT via two Sun SPARC 10 work stations and ISDN. RESULTS: The transmission of 121 CT data sets from 116 patients revealed a sufficiently fast average transmission time of 15 (6-53) minutes and average transmission costs of DM 9.00 per examination. The system was technically reliable, cost-efficient and practicable in clinical routine application. CONCLUSIONS: Teleradiology enables remote hospitals to provide an emergency CT service even if there is no radiological specialist available outside office hours. Thus time-consuming and cost-intensive patient transfers and delay of therapy can be reduced.

Austria↗
PubMed1996

[Dose reduction in computerized tomography with a new scan procedure].

A new investigation technique in computed tomography--the Smart Scan process--and the associated reduction in tube current are discussed. In addition, the reduced dosage values resulting from the reduced current values are compared with those of a standard measurement and image characteristics such as picture unit noise are evaluated. By means of three special water phantoms with dimensions corresponding to those of actual patient geometries and a pool of 183 patients, the Smart Scan process was tested by the control algorithm implemented on a spiral computer tomograph. The dosage values with and without the Smart Scan being activated were determined. Dosage reductions of up to 18% can be realized with this new examination technique. In particular, patients with transverse oval head profiles will benefit from this modality.

Adolescent↗
PubMed1996

[PC-assisted network for quality control in film development].

Measuring of the daily performance of the film processing system by sensitometry is an important part of quality assurance in radiologic imaging. Computer-assisted evaluation of the measurements may be useful, especially in large hospitals with numerous image processors to be tested. We present a PC-based quality assurance network which was implemented at the University Hospital in Innsbruck in 1994. Direct data transfer from the evaluation stations to the technical service center of the hospital facilitated problem solving and resulted in a significant decrease of loss of time due to technical failures. An expansion of the network to outside institutions is planned for the future.

Computer Communication Networks↗