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The number of scientific papers on iodinated contrast media is declining. Indeed, comparative trials between high-osmolality and low-osmolality agents largely showed the higher safety and tolerability of the latter, and this is no longer a matter of discussion. Only financial constraints could prevent a total conversion to low-osmolality agents. Research comparing low-osmolality (nonionic monomers, ionic dimer) and iso-osmolality contrast media (nonionic dimers) are still ongoing. Both classes of nonionic compounds proved safer than the ionic dimer. The relative merits of nonionic monomers and nonionic dimers are a matter for debate, and criteria for a selective use of different agents for different procedures could be discussed.

Il ruolo dell’imaging nel follow-up delle pazienti curate per neoplasia dell’apparato genitale (cervice uterina, endometrio, ovaio o vulva) ha come scopo principale, oltre alla valutazione dell’efficacia della terapia stessa, il tempestivo riconoscimento dell’insorgenza di un’eventuale recidiva: circa il 30% delle pazienti con neoplasia della portio muore per persistenza o recidiva della malattia entro i primi 2 anni dal trattamento; nel carcinoma dell’endometrio, una percentuale variabile tra il 3% ed il 15% delle pazienti a basso rischio (stadio Ia e Ib) e tra il 20% ed il 45% di quelle ad alto rischio (stadio Ic o superiore) sviluppa una recidiva dopo il trattamento; in circa i 2/3 delle neoplasie ovariche sono presenti localizzazioni extrapelviche al momento della stadiazione con conseguente elevato rischio di recidiva.

Study design: Case report of an unusual use of AMS 800 (American Medical Systems, Inc., Minnetonka, Minnesota) artificial urinary sphincter cuff in a female patient affected by neurogenic urinary incontinence. Objective: To describe this rare surgical solution. Setting: Department of Urology in Italy. Methods: A 43-year-old woman affected by flaccid paraplegia, acontractile bladder and incompetent bladder neck, underwent an implantation of an artificial urinary sphincter AMS 800. After 7 years, a mechanical failure of the device occurred and pubovaginal sling (PVS) utilizing the cuff of the sphincter was employed due to the poor quality of rectus fascia and the development of previous allergy for some heterologous materials. Results: At 17 months follow-up, the patient is contnent and able to empty the bladder by clean intermittent self-catheterization (CIC). Conclusion: The risk of developing an allergy reaction due to the employment of heterologous materials and the impossibility to use the rectus fascia obliged us to adopt the pre-existent cuff of the artificial urinary sphincter AMS 800.

Extravasation of contrast material is a well-recognized complication of contrast-enhanced imaging studies. The management of this complication is contentious; therefore, the Contrast Media Safety Committee of The European Society of Urogenital Radiology decided to review the literature and issue guidelines. A comprehensive literature search was carried out. The resulting report was discussed at the 8th European Symposium on Urogenital Radiology in Genoa, Italy. Automated power injection may result in extravasation of large volumes and may or can lead to severe tissue damage. Infants, young children and unconscious and debilitated patients are particularly at risk of extravasation during contrast media injection. Fortunately, most extravasations result in minimal swelling or erythema, with no long-term sequelae; however, severe skin necrosis and ulceration may occur. Large volumes of high osmolar contrast media are known to induce significant tissue damage. Compartment syndrome may be seen associated with extravasation of large volumes. Conservative management is often adequate, but in serious cases the advice of a plastic surgeon is recommended. Based on the review simple guidelines for prophylaxis and management of contrast medium extravasation injuries are proposed.

The authors analyze whether the imaging approach consisting of ultrasonography and plain film in patients with renal colic is still of value when urography is replaced by unenhanced helical CT (UHCT) in unsolved cases.Eight hundred and three consecutive patients were investigated with US following hydration and KUB, 164 of whom (20.4%) subsequently underwent UHCT (42 with the aim of mapping the excretory pathway and 122 (15.2%) because US and KUB were not considered as fully diagnostic).The 42 patients with detectable ureteral stone (plus possible hydronephrosis) on KUB + US and subsequently examined by UHCT to plan interventional treatment all had a positive UHCT examination. In 62 patients the diagnosis following KUB + US was uncertain (possible stone or possible hydronephrosis) and UHCT depicted the stone and/or the hydronephrosis in 34. In 60 patients the combination of KUB + US was negative but colic recurred and UHCT was positive in 17 patients.The comparison of the present results with a previous study in which KUB and US were followed by IVU in unsolved cases underscores the value of the first approach with KUB and US. The need for further diagnostic investigations when KUB + US are either not conclusive or negative and colic recurs is also confirmed. On the basis of our present data and in agreement with the literature IVU can be safely replaced by UHCT.It is authors' opinion that in settings where KUB, US and UHCT are available throughout the 24 hr the approach consisting of KUB plus US and UHCT in unsolved cases can be preferred in view of its on lower cost and above all lower X-ray dose to patients as compared to UHCT as the sole investigation.

A large majority of the papers to appear in scientific journals in recent years on the subject of contrast media have focused on agents for magnetic resonance imaging (MRI) and ultrasonography (US). Iodinated contrast media have received relatively little attention in spite of their widespread use, which far exceeds that of agents for US and MRI. Possibly, scientific arguments concerning iodinated contrast media came to an end because current agents are so good that it seems unlikely that anything more than modest incremental improvements are possible (DAWSON 1995). Available contrast agents are so efficacious and safe that it is becoming more and more difficult to identify significant differences among them. Possibly our methodological approach to clinical trials needs to change if such small differences are to be detected. Clinical studies could be better focused on populations that are more susceptible to contrast media toxicity, and other scientific branches, such as pharmacoepidemiology, could help us to improve the methodological approach to clinical trials (STACUL and SPINAZZI 1997).

We studied renal function and perfusion after the i.v. injection of Gd-DTPA-BMA, a nonionic paramagnetic contrast agent, to assess renal morphology and function in normal subjects, in renal insufficiency patients and in patients with hepatic failure and normal renal function. The latter were chosen because some patients with advanced hepatic failure may suffer from the hepatorenal syndrome, characterized by severe vasoconstriction in the renal cortical vessels. We investigated if dynamic MRI can detect early renal perfusion abnormalities in the patients who will eventually develop this syndrome.Thirty MR examinations were carried out on 30 subjects after the i.v. injection of Gd-DTPA-BMA. Our series consisted of: 10 normal subjects; 10 renal insufficiency patients; 10 patients with hepatic failure and normal renal function. MR examinations were performed on a Philips ACS II scanner operating at 1.5 T. Two sequences were carried out in all cases: T1-weighted SE and T1-weighted TGE sequences after the bolus injection of .1 mmol/kg contrast agent. Renal longitudinal diameter and parenchymal thickness were measured in all cases and signal intensity time curves were always made. The signal intensity of the cortex, corticomedullary junction, medulla and pyelocaliceal system of each kidney was measured using a region of interest (ROI). The signal intensity curves were made considering quantitative parameters, including the area below the curve (ASC), the peak (P) and the time to peak (T-P).Longitudinal diameter and parenchymal thickness values were significantly lower in renal insufficiency patients than in normal subjects. Four phases were demonstrated after i.v. contrast agent injection in normal subjects, namely A) the cortical phase, B) the corticomedullary junction phase, C) the medullary phase, D) the pyelocaliceal phase. No signal intensity decrease in the medullary and pyelocaliceal curves was observed in renal insufficiency patients. Signal intensity curves values were lower in hepatic failure patients than in those with normal renal function. Hepatic failure patients could be divided into two groups: 5 patients had low P and ASC values and 4 had normal P and ASC values. The patients with lower P and ASC values developed the hepatorenal syndrome within a few months of the MR examination.Signal intensity decreased in the pyelocaliceal system phase in normal subjects because of the high paramagnetic contrast agent concentration. The lack of signal intensity decrease in renal insufficiency patients was caused by the reduced capability of concentrating Gd-DTPA-BMA. Lower signal intensity values in hepatic failure patients may be considered an early sign of the hepatorenal syndrome.

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.

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.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).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%).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.

More than 70 years of research on contrast media (CM) had led to the synthesis of effective and extremely well-tolerated compounds. Moreover, we have achieved a deep knowledge of the design principles of CM molecule. We have learned that: - Nonionic contrast agents display lower toxicity than ionic agents. - Putting an iodine atom on a carrier molecule renders it more toxic. - More hydrophilic molecules are less toxic. - The nature of the carrier molecule substituents, other than iodines, may profoundly affect the overall toxicity. - Metrizamide has the lowest osmolality of any nonionic monomer commercially produced, but it is far from being the least toxic agent. - Being nonionic and having the lowest osmolality are still not enough to guarantee the lowest possible toxicity. - Iso-osmolal formulations of contrast agents still have measurable toxic effects [1].

The authors report on their experience gained during 5 years' use of a PACS Comm View (ATT 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 is2% 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.

Data concerning patients who underwent mammography and breast ultrasonography and then breast surgery were collected and analyzed with a computer archive system. In previous papers the authors reported both design and implementation of the computer archive and analyzed the results concerning uncontrolled collected data; in the present paper data concerning controlled cases are evaluated, distinguishing between symptomatic and asymptomatic cases. Asymptomatic patients represented 92% of the whole evaluated population. However only one third of the patients who underwent surgery for breast cancer was included in this group. Breast cancer was discovered in 65% of the patients who underwent diagnostic procedures and then surgery because of a palpable nodule. This percentage was lower (52%) in asymptomatic patients. Mammographic accuracy was about 90% in symptomatic patients and 81% in asymptomatic patients. Breast ultrasonography was performed as a subsequent step and always detected the lesion when palpable. Its sensitivity was 86% in asymptomatic patients. In patients who underwent surgery the false positive rate for cancer was higher with ultrasonography (59%) than with mammography (45%). Focal dysplasis were responsible for the majority of false positive diagnoses with both procedures. However, the false positive rate is low referring to the whole investigated population and is reshuffled by guided bioptic procedures. Ultrasonography was a useful tool when mammography had limitations: in fact ultrasonography detected a focal lesion in all patients with a surgically proven cancer and a previous negative mammography. The sets of data available from the continuous updating of the computer archive immediately clarified the differences between symptomatic and asymptomatic patients and stressed the diagnostic capabilities of the different procedures.

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.

The general requirements are analyzed of a system designed to acquire and manage radiological data of scientific interest. These requirements consist in: easy implementation, to develop the system in the same environment where it is going to be used; easy use, to avoid excessive needs and resources for the system to be managed in practice; reduced implementation cost, in terms of resources required for its implementation; user-oriented approach, in the sense of meeting the radiologists' requirements, and flexibility, for the system to be an effective tool for the widest range of possible applications. Two actual applications of this general approach are then discussed, one relative to breast investigations data, and the other to digital procedures (US, CT, DSA, MR) data. For each application the software tools employed are analyzed, together with the archive structures and the used codes, the collecting data procedures and the programs. For the breast investigations archive the possibility of obtaining standard periodic reports is pointed out. These reports summarize the global department activity in this area during selected periods (six months-one year). They allow interesting clinical conclusions to be drawn. As for the digital procedures archive, the possibility is stressed of searching different combinations of scientific data out of tens of thousands of cases in just a few minutes.

Up to now three-dimensional reconstructions in computed tomography have been applied mainly to the skeleton. This limitation is due to technical difficulties when dealing with images of the soft tissues. In order to overcome these limitations three new softwares were developed, thus enabling the operator to pre-elaborate and modify the axial CT images. The first program allows the operator to isolate the lesion and/or the anatomical structures of interest from the surrounding areas. The second program eliminates the areas of isodensity with the lesion it is obtained by means of a trackball. The third program enables the operator to write the modified axial images on the original file. The lesion and/or the structures of interest can thus be processed more easily by the 3D reconstructive program. The new softwares have been applied to 3D reconstructions of brain lesions, and two significant cases are presented. Furthermore, since the new softwares can enhance the quality of 3D images of the skeleton, the programs were also tested in cases of acetabular traumas.

Six patients with diskitis following lumbar disk surgery were investigated by Computed Tomography (CT). Four patients underwent CT in a rather early phase of the disease (5-37 days after the onset of the symptoms): a posterior paravertebral fluid collection was always recognized, while the plain film was normal. Later on (2-4 months), the classical signs of diskitis were evident, with both CT and the plain film. The collection was always present at CT. A reintervention, performed on 3 patients, revealed the purulent content of the collections. It seems reasonable to suggest a relationship between the collection and the subsequent diskitis; the collection is probably an early sign of the disease. Its detection is of great value, because it could allow an immediate and adequate therapy. The authors stress the usefulness of performing CT in an early phase on this kind of symptomatic patients.

Percutaneous puncture with echographic guide was performed in 37 patients with suspected abdominal abscesses. The abscess has been confirmed in 31 cases and it has been related to previous surgery in 21. In 3 cases the 3 small cavities were evacuated by a single-stage aspiration; in the other cases different drainage catheters, in relation to the size and the content of the cavities have been employed. Benefits of proteolytic agents, irrigation with saline solution and permanent aspiration are stressed. Successful drainage avoiding surgery was achieved in 23/31 patients (74%), and positive results have been obtained in multiple abscesses, multilocular abscesses and infected haematomas as well. A partial success was achieved in 3 cases (10%): the patients were submitted to surgery after a clinical improvement. Two complications occurred (bowel perforation and small liver laceration). The percutaneous drainage turned out to be a technique of choice in the great majority of abdominal abscesses, and should be considered a good alternative to surgery, particularly in high risk patients.

Iohexol has a slightly higher osmolarity in comparison with iopamidol; therefore it might induce a more pronounced diuretic effect and then a better distension of the excretory pathway. A trial was carried out in two groups of 50 patients with normal renal function who underwent urography, namely with 50 ml (15 gI) of iopamidol and of iohexol. No significant differences in the evaluated parameters (nephrography, calyces, pelvis, ureters and bladder) have been found. Both contrast media allowed to perform good quality urographies.

The review of 1405 digital intravenous subtraction angiographies carried out in the period may 1982-february 1985 showed in about 2% of the cases cardiac symptoms, which arose during or after the examination. In the great majority of the cases the symptomatology was characterized by angina pectoris. In order to better understand these data and analysing the results of the literature, a trial has been performed in 100 patients who underwent DSA. They have been divided into two groups in which two different contrast media, ionic (sodium meglumine diatrizoate) and non ionic (iopamidol) have been randomly injected. A detailed cardiologic anamnesis has been collected and EKG has been performed before and after each injection with pre-established gaps. The results showed that the incidence of cardiac symptoms and EKG variations is lesser with the non ionic contrast medium: therefore this agent is to be preferred at least in patients at risk from cardiologic point of view.

The authors refer the results of angiography in 46 patients with proven pancreatic carcinoma. Based on the prospective report there were 40 correct diagnoses, giving an overall accuracy of 86.95%. The incidence of the angiographic features has been investigated; basing on these findings the possibility of a radical surgery was suggested. 24 of these patients have undergone echotomography. The authors compare the results of the two investigations, concluding that these are complementary in diagnosis and prediction of resectability (invasion of great vessels, secondary deposits to the liver). Echotomography allows to recognize a large number of small dimension carcinomas, suggesting its use in the screening of those patients with suspected pancreatic neoplasm. Angiography is still essential to perform radical surgery.

The authors report the preliminary results of the intraarterial digital angiography of the liver. A series of 30 patients were examined comparing conventional and digital technique following the injection of the coeliac, splenic, hepatic and mesenteric arteries. The results obtained with the digital technique have been of good quality and sometimes even better in spite of significant dilution of the contrast medium. It is concluded that intraarterial digital angiography of the liver gives some advantages compared with the conventional technique, that is the use of a much lower concentrated contrast medium, the better visualization of the portal branches and its collaterals and the very low cost of the film material.

Intravenous Digital Subtraction Angiography (i.v. D.S.A.) was performed at the carotid bifurcation level in 259 patients with clinical or physical findings of a Cerebrovascular Insufficiency (C.V.I.). The angiographic examinations have been performed during two different periods, basically differing for the technology of the digital equipment and for the technique used. The personal experience showed how these two factors are important in determining the quality of the image and therefore the accuracy of the i.v. studies. Images of good quality of the common and internal carotid arteries have been obtained in 73% and 54% of the cases of the first period and in 93% and 82% of the cases of the second period. The role of the i.v. D.S.A. in the management of the C.V.I. depends not only upon the quality of the images, but also upon the surgical policy and from the availability of ultrasounds.

The authors have evaluated 22 patients with renal pelvis tumour (RPT) by means of excretory urography and ultrasonography. Six patients also underwent arteriography. The value of the three investigations in the diagnosis of the lesion, the nature, the pyelic origin and the extension are presented. It is concluded that urography remains the method of choice for the evaluation of RPT while ultrasonography may be considered complementary to urography in cases of non-functioning kidney, when the urographic filling device defect is uncertain and in the differentiation between the pyelic or parenchymal origin of the tumour.

The authors report the experience achieved at the Stanford University (USA) with a digital radiography system which allows the digitization of the film and of the images collected with photostimulable phosphors. The phosphor is essentially an intensifying screen where a latent image is stored after exposure to X-rays and is extracted by a laser scanning. The images collected with the digitized film and with the phosphor (chest, breast, bone) have been analyzed. The digitized film offers potential diagnostic advantages over the conventional film, because of the contrast manipulation and many other processing options. The possibility to recover the information of overexposed films appears very attractive. The photostimulable phosphors allow to get good quality images, with a consistent reduction of dose and costs. These plates offer the possibility, in the next future, to replace the conventional screen-film systems.

Intravenous digital subtraction angiography (DSA) was performed in 119 patients with lower extremity ischemia using a 14" amplifier. Four injections of contrast medium were usually necessary for a complete evaluation of this vascular region. Images of good quality were obtained in most cases; movement artifacts and a faint opacification accounted for any poor results, which occurred mainly under the knee. The technique of pixel shifting turned out to be very useful to remove movement artifacts. The "measuring field" allowed us to minimize the problem of the inhomo geneous saturation of the amplifier. In 8% of the cases an intra-arterial DSA has been performed after an unsatisfactory intravenous examination. Conventional angiography appears to be no longer necessary.

The authors evaluated the results of 24 percutaneous nephrostomies. Pelvic neoplasms involving ureters were the most frequent indications to the procedure (71% of the cases). In all patients the placement of a catheter was possible. The authors describe the techniques performed and evaluate their advantages and limits. The problems related to the use of nephrostomy in patients with widespread neoplasms and severely ill are discussed. The most frequent drawback was catheter dislodgement (25% of the cases). No serious complications occur. Percutaneous nephrostomy is a temporary or permanent form of urinary diversion in obstructive nephropathies, alternative to surgical nephrostomy.

Computed tomography allows today to reconstruct three-dimensional (3D) images from axial scans. The authors report their experience in cranio-facial pathology achieved in two Departments of Radiology (University of Trieste, Italy and University of Stanford, California). 3D images have been realized using two different softwares, one of which allows to reconstruct both soft tissue and bone structures. The applications in maxillo-facial traumas, cranio-facial malformations and head tumours are discussed. 3D images turned out to be very useful for the optimal visualization and for the spatial demonstration of the lesion and have potential applications in cranio-facial surgery and radiotherapy.

The authors judged the quality of the films in two groups of patients who underwent fast injection nephro-urography with iopamidol and meglumine sodium diatrizoate. The scores ascribed to the urograms obtained with the two contrast media have been compared. The ionic contrast medium got a higher score, at it allowed a better evaluation of ureters and bladder. Tolerability of the two contrast media has been evaluated.

The authors investigated the optimal characteristics of contrast media for use in intra-arterial DSA. 209 injections in 108 patients were evaluated, most of them in the abdominal and peripheral regions. In order to decrease contrast media osmolarity and obtain an adequate mixing with blood, contrast media with low iodine concentration were injected using the same volumes and flow rates of conventional arteriography. Good results were obtained with ionic contrast media, 100 and 150 mgI/ml. depending on the area investigated. The low concentrations allowed the use of ionic agents with an osmolarity very close to that of the non ionic contrast media: the pain has been eliminated and the heat sensation reduced. Furthermore the comparison with the cost of nonionic agents shows a great saving.

Nonionic contrast media (cm) are more and more widely employed in vascular radiology. These cm are the choice in some conventional arteriographies owing to their better tolerability. In intravenous digital subtraction angiography (DSA) the analysis of the personal material and of the literature allows to state that: the image quality with ionic and non ionic cm is similar; the tolerability of nonionic cm is slightly superior; the cardiac and renal toxicity of nonionic cm is slightly lower; reactions to nonionic cm take place with a lower frequency; the price of nonionic cm is considerably higher. Therefore nonionic cm seem to be slightly superior to ionic agents on the basis of these data and they should be theoretically preferred. The only doubt to their routine use in intravenous DSA is the high cost. Therefore we prefer to employ them in risk patients only, as ionic cm in current use are safe and cheap.

The results obtained in four successive trials based on the analysis of urography performed on patients with normal kidney function are reported. The scores obtained with a non-ionic contrast (iopamidol) were compared with those produced after injecting the same contrast medium with the addition of various diuretics (furosemide, various quantities of 5% glucose solution, 20% mannitol). The results obtained by injecting the diuretic together with the iopamidol were usually unsatisfactory. Injection of diuretic 15 ms after the iopamidol gave better results in the lower urinary tract, particularly the bladder. The best results were obtained by injecting 250 ml, 20% mannitol, after 15 ms. However this technique is not applicable to patients requiring a voiding cystourethrogram due to the inadequate opacification of the urethra it provides.

A trial was carried out with the aim to overcome the limits of the non ionic contrast medium (cm) in the urographic evaluation of ureters and bladder (poor distention and high density). 200 urographies have been performed in patients with normal renal function (group 1: sodium iodamide; group 2: iopamidol; group 3: iopamidol with glucose solution; group 4: iopamidol and injection of glucose solution after 15'). The scores ascribed to the four groups have been compared: in the comparison between ionic and non ionic cm a slight advantage of iodamide is evident, particularly in the evaluation of calyces and ureters. By adding glucose solution to iopamidol after 15', an improvement in the quality of the urogram has been obtained, but not statistically significant.

The clinical utility was evaluated of a computed radiographic system in urography. The system (FCR 101, Philips Medical Systems, Inc., Shelton, CT) is based on a photo-stimulatable phosphor screen (imaging plate) for X-ray image detection and storage. The X-ray information recorded on the imaging plate is converted into digital from and processed by means of a computer. After processing is completed, the digitized image is reversed back to analogic signals, which modulate the intensity of a laser beam scanning the image on a single-emulsion film (Fuji CR 633). Two hundred IVP's were obtained in four groups, of 50 patients each, with normal azotemic values by rapid infusion of a low osmolality contrast medium (iopamidol 150 mgI/ml). While conventional radiographs were performed on the first group of patients with the injection of 0.6 gI/kg body weight of contrast medium, digital examinations were carried out, in the remaining three groups, with the injection of 0.6, 0.3 and 0.12 gI/kg, respectively. The digital images were processed with the "Abdomen-routine" program. A specific algorithm was implemented in order to reduce the excessive contrast resolution of the bladder, which is due to the characteristics of the nonionic contrast medium and enhanced by the reading program. The image details were evaluated by two observers and then statistically analyzed with nonparametric tests. Statistical analysis did not show any difference in the quality of digital and screen-film images. Image processing improved some inadequate images, by reducing the contrast resolution of the bladder, and allowed a better detection of some details. Low doses (0.3 gI/kg) of a low osmolality (150 mgI/kg) contrast medium were enough to obtain good images. Another biological advantage was obtained by a consistent radiation dose reduction (about 40%).