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Biomedical subjects

F Stacul

Publications and source records attributed to F Stacul.

At least 19 recordsLinked to original sources
PubMed1998

Effects of a dimeric vs a monomeric nonionic contrast medium on renal function in patients with mild to moderate renal insufficiency: a double-blind, randomized clinical trial.

The efficacy and safety of nonionic dimeric contrast media in subjects with impaired renal function is largely unknown. The present study was aimed at determining the risk of tubular nephrotoxicity in patients with mild to moderate renal insufficiency who underwent intravenous urography (IVU) with the nonionic dimeric contrast agent iodixanol (Visipaque, Nycomed Imaging, Oslo, Norway). In a double-blind protocol 64 patients (55 males; mean age 68.3 years) with serum creatinine between 135 and 265 micromol/l who were to undergo IVU were randomized to receive iodixanol (a nonionic dimer) or iopromide (a nonionic monomer), 600 mg I/kg b. w. Renal function was evaluated before and 1 h, 6 h, 24 h, 48 h and 7 days after IVU with analysis of serum creatinine, urinary enzymes alanylaminopeptidase and N-acetyl-beta-glucosaminidase, and urinary microproteins alpha-1-microglobulin and albumin. Renal function remained stable in both contrast medium groups during the follow-up period. No statistically significant differences were observed between the monomer and the dimer in terms of urinary enzyme and microprotein excretion or serum creatinine. Transient radiocontrast-induced nephropathy developed in 1 patient who had received iodixanol. The administration of the nonionic dimeric contrast medium iodixanol, or of the nonionic monomer iopromide, entailed a low nephrotoxic potential in patients with mild to moderate renal insufficiency undergoing excretory urography.

Acetylglucosaminidase↗
PubMed1998

Ultrasonography and PACS.

Expectations and problems related to picture archiving and communication systems handling of ultrasound images are discussed. Sonography has peculiarities that must be considered when its integration with picture archiving and communication systems is planned, namely: (1) data volume is about 3 Mb per ultrasound examination and is usually lower than that of other imaging modalities; this makes many requirements less strict; (2) color images represent further problems which can however be solved with systems capable of performing the analog-to-digital conversion in more than 8 bits; (3) the available equipment comes with/without digital ports; the interfaces between the ultrasound unit picture archiving and communication systems are usually based on frame grabbing which might be sufficient for sonography; (4) equipment may be located in different departments or in private offices. Therefore solutions (mini-PACS limited to ultrasound, sub-PACS with a modular development, global PACS) are closely related to the environment. Our personal experience began with the installation of a commercial system 10 years ago. With respect to sonography, picture archiving and communication systems allowed a more reliable and quicker retrieval of previous examinations, the immediate availability of images in different sites throughout the hospital and to avoid filming. About 70000 ultrasound examinations have been archived on optical disks, with a mean of ten images per investigation. Since November 1991, the picture archiving and communication system has been the only archive where such images can be found. The location of workstations in the wards allows the almost real-time availability of images and the immediate availability of reports right after typing. A questionnaire was given to all the hospital's clinicians and the following advantages were pointed out: no examination repetition, no unnecessary investigations, shortening of hospitalization time, impact on treatment choices. Our experience is going on with a new project, DPACS, providing all the services of the former system and offering a full integration with RIS both in the hospital and in the city areas and allowing communication between DICOM and non-DICOM compliant devices.

Humans↗
PubMed1997

[A comparison between an ionic paramagnetic contrast agent (Gd-DTPA) and a nonionic one (Gd-DTPA-BMA) in functional kidney evaluation with magnetic resonance].

INTRODUCTION: The combination of TGE sequences with bolus injection of paramagnetic contrast agents permits to study renal function and perfusion. We studied renal function with both an ionic (Gd-DTPA) and a nonionic paramagnetic contrast agent (Gd-DTPA-BMA) to compare their kinetics in normal kidneys. MATERIAL AND METHODS: Twenty MR examinations were performed on 20 subjects with normal renal function. Ten subjects were examined after i.v. injection of Gd-DTPA and the other ten subjects after i.v. injection of Gd-DTPA-BMA. MR examinations were performed on a Philips ACS II unit (1.5 T). Two sequences were acquired in all cases; an SE coronal T1-weighted sequence (TR/TE = 600/19 ms) and a TGE coronal T1-weighted sequence (TR/TE = 12/5 ms, flip angle = 25 degrees) performed after bolus injection of the contrast agent at 0.1 mmol/kg. Signal intensity time curves were obtained in all the cases. The signal intensity of the cortex, corticomedullary junction, medulla and the pyelocaliceal system of each kidney was measured using a region of interest (ROI). Signal intensity curves were analyzed considering some quantitative parameters such as the area under the curve (AUC), the peak (P) and the time to peak (T-P). RESULTS: In the subjects with normal renal function, four phases were demonstrated after the i.v. injection of either Gd-DTPA or Gd-DTPA-BMA, namely the cortical phase, the cortico-medullary junction phase, the medullary phase and the pyelocaliceal system phase. No statistically significant differences between the two agents were demonstrated in signal intensity time curves and quantitative parameters. CONCLUSIONS: Gd-DTPA and Gd-DTPA-BMA showed the same efficacy in renal function studies.

Analysis of Variance↗
PubMed1996

Nonionic monomers and dimers.

The 10-year-long debate regarding high-os-molar ionic vs low-osmolar nonionic contrast media has ceased. Now we are confronted with at least eight nonionic monomers and two nonionic dimers. Do these ten contrast agents differ from each other? The manufacturers say yes, but in clinical practice differences have, with a few exceptions, turned out to be very marginal and by no means to the extent which was found between high- and low-osmolar contrast media. Only time will tell whether there are any major differences of clinical importance between the "old" and the new nonionic agents.

Angiography↗
PubMed1996

Safety profile of new non-ionic contrast media: renal tolerance.

The possible nephrotoxic potential of X-ray contrast media is one of the main concerns when testing new compounds. Iomeprol is a new nonionic monomeric contrast medium which has been tested during preclinical studies and clinical trials. Preclinical studies showed that the product has a renal tolerance comparable to that of other nonionic contrast media (iopamidol and iohexol) and less effects on renal histology than dimers like iodixanol and iotrolan. The clinical safety of the product has been evaluated during diagnostic procedures in more than 8000 patients and in particular renal function was studied in 988 patients. Results showed that iomeprol did not cause any alterations of clinical laboratory indices for renal function nor any cases of acute renal insufficiency.

Animals↗
PubMed1996

Dose effect of nitrendipine on urinary enzymes and microproteins following non-ionic radiocontrast administration.

BACKGROUND: Although calcium-channel antagonists have been proposed as prophylaxis to prevent radiocontrast-induced nephropathy, the dose and dose interval to achieve a protective effect have not been quantified in humans. METHODS: In a randomized, double-blind protocol we studied urinary enzyme and microprotein excretion in 121 outpatients (mean age 65.3 +/- 9.3 years, 62% male) with normal renal function who were to undergo digital subtraction arteriography with iohexol or iopentol. The subjects were treated with a single dose of placebo (group 1) or nitrendipine 10 mg (group 2) or 20 mg (group 3) p.o. 1 h before the procedure. Blood and urine samples were collected 1 h before, 1 h after, and 24 h after contrast administration. Study variables included contrast volume and serum creatinine, and urinary creatinine, osmolality, albumin, alanylamino-peptidase (AAP, a brush border enzyme), N-acetyl-beta-glucosaminidase (NAG, a lysosomal enzyme), and alpha-1-microglobulin (alpha-1-micro, a filtered microprotein). RESULTS: Serum values of creatinine remained unchanged during the study period. Albuminuria was not affected by contrast administration, whereas AAP, NAG, and alpha-1-micro increased significantly, all except AAP returning to baseline at 24 h. Pretreatment with nitrendipine did not reduce enzyme excretion, although AAP levels were lower in general in the group assigned to the 20-mg dose. Acute renal failure, defined as a 50% increase of serum creatinine 24 h after radiocontrast administration, was found in eight patients: four from group 1 (8.3%), three from group 2 (6.5%), and one from group 3 (3.7%). CONCLUSIONS: Neither the course of enzyme excretion nor the incidence of acute renal failure following radiocontrast administration were affected by single doses of calcium antagonists. AAP levels were lower in general in subjects taking the 20-mg dose of nitrendipine. This study also indicates that a single low or normal dose of nitrendipine per os is not effective prophylaxis before radiocontrast administration. The designs of future studies investigating the "nephroprotective' effect of calcium-channel antagonists per os should incorporate (1) the use of repeated doses to saturate hepatic metabolic pathways, and (2) the control of confounding variables in the measurement of urinary enzymes.

Acetylglucosaminidase↗
PubMed1994

[A PACS system in clinical reality: the Trieste project].

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.

Attitude to Computers↗
PubMed1993

Ultrasonography and plain film versus intravenous urography in ureteric colic.

Urography (IVU) is considered the best first investigation in patients with suspected ureteric colic, but recently ultrasonography (US), combined with a plain film of the abdomen (KUB), has been suggested as an alternative. We have undertaken a prospective study to see if this approach can be used in an Emergency Department by radiologists with different amounts of ultrasound experience. Some 180 patients with suspected ureteric colic presenting to the Emergency Department over an 8-month period were studied. They had a plain abdominal film (KUB) and US examination of the kidneys, ureters and bladder following hydration. Some 120 patients subsequently underwent IVU at a mean interval of 3.5 days after the ultrasound examination. Of these, 15 patients passed a stone before their IVU. Of the remaining 105 patients, 44 had an IVU positive for stone and 61 had a negative IVU. Fifty of the 60 patients who did not have an IVU had clinical follow-up and 31 had ultrasound. Our findings in this prospective study suggest that in the hydrated patient the combination of KUB plus US is a sensitive but not very specific screening test (sensitivity 95%, specificity 67%). Because of the high negative predictive value of KUB plus US (95%), urography is not likely to be helpful when KUB plus US are negative. Urography is indicated only if KUB plus US findings are equivocal or if intervention is necessary. If we had used KUB plus US alone as the first test in our patients, urography would have been unnecessary in approximately 60%. Twenty per cent of our patients passed a stone in the first 48 h.

Colic↗
PubMed1992

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.

Computer Communication Networks↗
PubMed1990

[Simplified urographic technique using non-ionic contrast media].

Urography is not to be performed following a standard procedure. However, some key-films can be defined which are to be routinely employed. If needed, additional radiographs can be performed. We tried to optimize the urographic technique combining low X-ray exposure and adequate diagnostic assessment with the injection of 17.5 gI of a non-ionic agent. Two groups of 50 patients each were investigated. In the former, the technique we currently employ in our Institute was used: plain film, 2 nephrotomograms (1'), full-length view (7'), kidney view with ureteral compression (15'), and full-length or bladder view (20'). In the latter group, a more simplified technique was used: plain film, 2 nephrotomograms (1'), kidney view (7'), and full-length view (15'). A compression device was positioned immediately before contrast medium injection and released immediately before the 15-minute exposure. Both urographic techniques allowed high scores to be reached (after the Kelsey Fry method), with no significant differences among the evaluated parameters. Thus, the technique employed on the second group is to be preferred, because it shortens examination time and reduces X-ray exposure. However, a simplified technique increases the radiologist's responsibility: it is thus essential for an experienced uroradiologist to accurately supervise the procedure and immediately decide what to do next.

Adult↗