The performance of different pressure pulse generators for extracorporeal lithotripsy: a comparison based on commercial lithotripters for kidney stones.

By using needle hydrophones and a PC-controlled experimental set-up, the acoustic output of 10 commercial extracorporeal shock-wave lithotripters has been measured. The pressure field was measured in the focus, along the beam axis, in the focal plane and "at the skin level" (a plane orthogonal to the beam axis, 5 cm backward from the focus, assumed as the entrance site of the pressure pulse into the patient's body). The set of tested instruments included the three technologies nowadays in use to generate the pressure pulse, namely electrohydraulic, electromagnetic and piezoelectric. Notwithstanding large intratechnology variability, the results indicate that electrohydraulic and electromagnetic generators can provide comparable performances. Piezoelectric generators produced pressure pulses with less energy than the others. Possible implications of the experimental results on treatment safety and effectiveness of kidney stone destruction are discussed.

[A PACS system in clinical reality: the Trieste project]. / Un sistema PACS nella realtà clinica: il progetto di Trieste.

The authors report on their experience gained during 5 years' use of a PACS Comm View (AT & T and Philips) in daily clinical practice. The system proved to be very effective in the preparation phase (retrieval of previous investigations), with major advantages over the conventional retrieval modality. The rate of unretrieved images is < 2% and their retrieval times are 10-210 seconds according to different archiving systems. The retrieval of previous images at the two workstations of our department took actually place 20 times a day--that is, much more than in past years. The reporting function was not implemented at the workstation due to its inherent limitations. Communicating the diagnoses (images and reports) to the hospital wards with PACS and RIS was highly appreciated by the referring physicians and a questionnaire distributed among them demonstrated that rapid data access: 1) avoids exam repetitions or unnecessary investigations (81.3% of answers); 2) avoids the request of previous medical records (80% of answers); 3) markedly shortens (two or more days) hospitalization time (100% of answers); 4) has a major impact on treatment choices (100% of answers) and 5) improves the efficiency of referring physicians (93.8% of answers). All the images acquired by the 5 connected modalities were entered in a juke-box with optical disks. Therefore, archive size is likely to reduce in the future. Slightly fewer films (about 14,000 USD/year) are now used.

PACS experiences in Trieste.

The installation of a commercial PACS in the Hospitals of Trieste has been the start-point for a project of technology assessment, aimed at the evaluation of technical, clinical and economic aspects related to the introduction of this new and expensive technology in the health care system. During more than two years of use of this system in the clinical environment, several research activities have been carried out concerning the analysis of the organization of radiology departments in Italy, the analysis of work and data volumes, the evaluation of technical and clinical performances of PACS versus conventional film-based radiology, the integration between PACS and RIS, the experimentation of teleradiology applications. An overview of the most important activities and related results is given in this paper as well as some indications about future developments of the Trieste Project.

[Modular project of the Picture Archiving and Communication System (PACS). Preliminary clinical experience. II]. / Sistema PACS a progetto modulare. Esperienza clinica preliminare. II Parte.

In the previous paper in this volume the PAC System installed in the Radiology Department of the University of Trieste has been described and its advantages and limitations have been analyzed, mainly from an operational point of view. This paper deals with the clinical evaluation of the system in ordinary operative conditions. A series of cases with specific characteristics was monitored in order to reveal different performances in both diagnostic process and conclusions using the PACS viewing console (DW) vs. conventional CRT film images on alternators. In a first test, 100 routine (not pre-selected) brain CT cases were independently analyzed by 4 radiologists, each of them giving 2 interpretations of the same case, one based on film and the other on PACS. The data were analyzed by conventional statistical methods, showing a substantial agreement of the results obtained with the 2 modalities. A second test concerned the evaluation of 100 lumbar intervertebral disks by CT, with the same procedure as above. Four radiologists were again asked to decide on film and PACS images about normality, protusion, or herniation of the disks. The results demonstrate the possibility of adequately reporting on the PACS monitor and stress the need of an adequate training period and the efficacy of the image processing capabilities of the system.

[Modular project of the Picture Archiving and Communication System (PACS). Preliminary operational experience. I]. / Sistema PACS a progetto modulare. Esperienza operativa preliminare. I Parte.

Since september 1988 a PAC System (Comm View by AT & T and Philips) has been operating in the Radiology Department of the University Hospital, Trieste. A research project is presently in progress aiming at providing factual evidence for the evaluation of this kind of systems as far as operational, technical, clinical and economic aspects are concerned. The general approach to this research consists in implementing and monitoring a PACS in a stepwise way, starting with a small system connected to some digital modalities only, in order to test the feasibility and effectiveness of the system within a Radiology Department, and to test the possibility of matching the PACS to the Radiological System. The present paper describes in detail the present configuration of this entry-level system and its technical features. The planned development (october 1989) is also depicted. Further developments devise at managing in an integrated way all the radiological images of the four hospitals of Trieste. At present, the PACS is currently used to manage and store on optical disks all the images acquired from the connected modalities plus the related reports, and to perform the reporting sessions for CT examinations (brain and abdomen). The present research effort is devoted to two main areas: clinical evaluation and operational analysis. The object of the operational analysis was the assessment of the impact of PACS on the operations of a Radiology Department. The general approach followed for this research consists in analysing the procedures as they are performed in the conventional way (manual operations), and comparing them to the way they are, or could be, performed using a PACS System (automatic operations). This stage of the project is divided into three phases, concerning respectively the analysis of the organization and operations before PACS, the analysis of the impact of PACS in its initial configuration and the forecast of the influence of PACS in its future setting. A first evaluation concerned the activities carried out from the moment the images are generated to the moment they are ready to be achieved. They include image acquisition, reporting, delivering and returning of images from the departments. The time required to carry out each of the activities involved was recorded, both in the manual and in the automatic version; furthermore, a more detailed analysis was performed on the reporting procedure. The conclusions reached through this analysis are that this kind of operation is mostly affected by the way the Radiology Department is managed, rather than by the tools employed.(ABSTRACT TRUNCATED AT 400 WORDS)

Trieste PACS project: a functional assessment.

A picture archiving and communication (PAC) system (CommView by AT&T and Philips) has recently been installed in the Radiology Department of the University of Trieste, Italy, and is currently under experimental evaluation. The current status of the system and the planned developments are reported. A major project at present is the evaluation of the impact of the PAC system on the radiology system on a functional basis, by applying in the medical field a modelling methodology developed to analyse manufacturing systems. Other research in progress is devoted to technical, clinical and ergonomic aspects, on the basis of a comprehensive assessment project.

[Evaluation of the performance of 8 computerized tomographs in clinical use in Italy]. / Valutazione delle prestazioni di 8 tomografi computerizzati in uso clinico in Italia.

In the past few years the use of CT scanners has widely spread in Italian health care institutions. This methodology has thus become an important part of our national health service--which creates the need for an accurate study of the various aspects of the phenomenon, e.g. technological, diagnostic and economic. In order to evaluate the quality of the CT scanners used in our country, we asked the majors suppliers of the Italian market to provide us with a unit from their production. Six out of 7 companies complied with our request. A standard protocol was used to evaluate the performance of 8 CT scanners, currently used in Italy. The following parameters were evaluated: spatial resolution, contrast resolution, noise, slice thickness, uniformity, linearity and radiation dose. Five currently-used operating modalities were employed. The results allow an overall assessment of the performance of the 8 CT scanners.