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This paper reports the results of the evaluation of an automatic system developed to analyze radiographic densities. This system, called RADEN, has been implemented at the Institute for Information Processing of the Italian National Research Council in Pisa. Forty-three pairs of abdominal X-ray films were obtained before and after the administration of ionic iodate contrast medium (i.i.c.m.) during urographic examinations. The 86 X-ray films were acquired and digitized using a computer-controlled optoelectronic device with a sampling step ranging 125 microns to 250 microns. The resulting images were arrays of 512 x 512 pixels, each one quantified on a byte (256 gray levels). The computing system included a high-performance personal computer equipped with a video RAM board having built-in facilities for image processing and with an optical disk to archive the images. Automatic and semi-automatic procedures were developed to segment, recognize and classify the images and to characterize three homogeneous regions--i.e., bone, water and air. The output data were compared with the area values of the air densities computed directly on the X-ray films by a radiologist. Furthermore, both data sets were compared with the scores given in a blind study by four observers. The subsequent statistic analysis showed the increase in air density areas after i.i.c.m. administration and the applicability of the implemented system to the automatic examination of abdominal radiographic densities. The results encourage to believe that the proposed approach could be employed as a first step for the development of quite a more complex system oriented to X-ray image understanding and to assisted diagnosis.

The 2nd generation lithotripter LITHOSTAR plus was used for extracorporeal shock wave lithotripsy of 9 kidney stones, 2 ureteral calculi and 2 bladder stones in 10 children 15 months to 17 years old. Ultrasonic stone localization was used in 2 children, x-ray guided stone localization in 8 children. General anesthesia was necessary in 6 children. A stone free rate of 60% was achieved after 1 treatment. Except for one 14-year old boy no adjuvant procedures like percutaneous nephrostomy or ureteral stents were applied. No major complications were encountered.

A modification of a previously described method for visualizing the urethrovesical junction is described. This modification is easier to perform, less messy, and obtains superior images to the method now used. A new method for outlining urethral strictures is also described. Both methods use an 8-F feeding tube.

A new small caliber single-lumen balloon catheter has been devised specifically for retrograde ureterography. It is simple to use, does not traumatize the intramural ureter and provides excellent ureteral visualization.

Twenty high risk patients with benign prostatic hyperplasia and urinary retention were treated by insertion of an intraprostatic spiral. The device was positioned under fluoroscopic guidance using a technique developed by us. The procedure required only local anaesthesia and successfully relieved the obstruction in all patients. At the six-month follow-up full continence had been achieved in 15 patients (75%). Three patients (15%) complained of mild stress incontinence but this was not severe enough to require removal and repositioning of the spiral. A 92-year-old patient reported severe incontinence despite correct positioning of the spiral. Removal of the spiral was necessary in one of the continent patients who was receiving anti-coagulant drugs because of sudden, severe macrohaematuria with subsequent acute urinary retention. The spiral became displaced and required repositioning in one patient. Median residual urine volume was constantly lower than 50 ml and the median maximal flow rate at six-month follow-up was 13.2 ml/s. Our long term follow-up study shows the effectiveness and safety of the prostatic spiral as an alternative treatment for selected patients with urinary retention caused by benign prostatic hyperplasia.

A method for ultrasonically guided fine needle pyelography is described. The procedure involves puncture of the renal pelvis with a long (150-200 mm) 0.8 mm needle which is subsequently bent and fixed to the skin. Puncture of the calyceal system can be performed even in cases of very mild dilatation and contrast medium for detailed radiologic investigation injected. The procedure is simple, safe and inexpensive and it has been performed on 49 patients without complications.

Retrograde intrarenal surgery (RIRS) utilizing flexible, actively deflectable instruments has become a valuable asset in the diagnosis of upper urinary tract pathology and the treatment of stone disease. Flexible endoscopic surgery of the proximal ureter and in the intrarenal collecting system constitutes the natural extension of rigid instrumentation in the upper urinary tract. At our institution retrograde ureteral and intrarenal surgery has become an +integral part of our diagnostic and therapeutic armamentarium. This is documented by almost 300 treatments and diagnostic procedures performed in the upper urinary tract over the past 3 years.

Within 26 months a total of 4,126 procedures were performed on the ESWL multipurpose table. Forty percent of the procedures were comprised of endourology, 25% functional urinary tract radiology, and 37% ESWL therapy. Biplane fluoroscopy is an extraordinary help for percutaneous interventions. A further advantage is the possibility to perform endourology and ESWL in one session without having to transport the patient. This has facilitated pre- and post-operative ancillary measures in a total of 35.3%. Seventy-six percent of stones greater than 15 mm were managed via indwelling stents. In situ ESWL for ureteral stones has become the therapy of choice in more than 80% of patients due to the availability of radiological localization systems and a complication and failure rate of 20% for the push-and-smash procedure. The multipurpose table is equally successful as the piezoelectric system for ESWL therapy. Drawbacks include operational inconvenience with percutaneous interventions and the necessity to change patient position during ureterorenoscopy and retrograde pyelography. The multipurpose unit used is a valid compromise for ESWL and percutaneous endourology. For purely diagnostic interventions, a standard x-ray table is preferred.

A computed radiographic system for generating and archiving digital radiographic images was employed in ivp. The system produces 2 digital images per exposure: the first one simulates a conventional radiograph, while the second enhances some spatial frequencies and emphasizes the structure borders. The conventional radiographs and the digital images of 50 patients submitted to ivp were reviewed by four experienced radiologists to evaluate their comparative quality, and the results were statistically analyzed. Digital images proved to be better than conventional radiographs for some of the selected parameters, especially in the evaluation of renal edges and sometimes for calyceal opacification. As for the other parameters, no statistically significant difference was observed between conventional radiographs and digital images.

A total of 78 females whose complaints failed to fit the scope of known urological and gynecological disorders were under study. Beside the routine patterns, the multiple modality diagnostic technique included radionuclide investigation of the kidneys, determination of the hormonal profile, thermographic examination of inner genital organs, echo scanning of the kidneys and genital organs, hysterosalpingography, simultaneous performance of excretory urography and transuterine pelvic phlebography. X-ray anatomical examinations revealed that the lower part of the ureter was entangled by vaginouterine veins. The side of urodynamic disorders corresponded to that of more manifest varicosis. In those with bilateral disorders more manifest dilatation of the upper urinary tract was noted on the side where varicosis was more pronounced. Based on the data analysis, the authors concluded that simultaneous uro- and phlebographic examinations not only revealed the status of the upper urinary tract, intra- and extraorganic venous systems but promoted a reliable detection of the reasons for urodynamic disorders: the compression due to the enlarged disposed organ or dilated venous vessels. The data on the agreement between of the varicosis-affected side and that of the urine passage through the upper tract was impaired in all patterns of "pelvic varicocele" enables one to reveal some pathogenetic urodynamic failures in females. It can be concluded that simultaneous excretory urography and transuterine pelvic phlebography provide an extensive information on the upper urinary tract, internal genital organs and the pelvic venous system. The method is easily performed in the outpatient settings, avoids serious complications and can be regarded as a prospective additional technique for the examination of females with a gynecological history during urological care.

The endoscopy has come a long way since the first works by BOZZINI in 1806 and considering that the eye guides all the other senses and confirms their impressions, with the introduction of the transurethral ureterorenoscopy, the urologist can now see the entire ureter, the renal pelvis, the infundibuli and calices, thus enabling him to confirm or rule out the pathology in a non-aggressive way in cases in which only a surgical operation would have done this.

A computed radiographic system for generating digital film images was evaluated in the performance of excretory urography. Three experienced radiologists reviewed digital and conventional screen-film urograms for 100 patients in a prospective study to evaluate the clinical utility of the digital system. Results indicate no difference between digital and screen-film urograms in diagnostic sensitivity, specificity, or receiver-operating-characteristic curves for differentiating normal from abnormal studies. Readers' performances in making specific diagnoses were also the same with both techniques.

A new intraoperative renal radiography technique using Polaroid film is presented. The quality of the Polaroid radiograph is satisfactory enough to visualize radiopaque calculi and provides good information on the localization of intrarenal calculi in a short time. The time required for photographic development is 15 seconds and a dark room is not necessary.

The male urethra can be demonstrated following intravenous urography by having the patient void against the partial obstruction produced by a penile clamp. The clamp is useful for both the normal or stenosed male urethra.

The described urological table with 14" (36 cm) image intensifier represents a new concept. Instead of the conventional technique, i.e. fluoroscopy with a 9" (23 cm) image intensifier and radiography with film-screen combinations in a cassette, all X-ray diagnostic work is done with a 14" (36 cm) image intensifier and a 100 mm spot film camera. Field size of the X-ray image intensifier as well as spot film image quality are satisfactory to replace the conventional radiographic technique. The radiation exposure of patient and examiner is reduced significantly by the spot film technique. Omission of conventional radiographic technique allows reduction of table length to 100 cm instead of the conventional 140 cm. Furthermore, the new urological table facilities the anaesthesist's access to the patient.

The imaging performance of new high-strip-density (HSD) grids having 57 lines/cm was compared with that of conventional low-strip-density (LSD) grids having 33 or 40 lines/cm. The unique advantage of HSD grids is that, under most standard radiographic conditions, the grid lines are not noticeable on the final image, even if the grid is stationary. This is due to the combined effect of the high fundamental spatial frequency of HSD grids, the modulation transfer function of screen-film systems and of the human visual system, and scattered radiation. Monte Carlo simulation studies, phantom images, and clinical evaluation indicate that HSD grids can provide contrast improvement factors and Bucky factors that are comparable to or slightly better than those obtained with LSD grids. Therefore, it may now be possible to eliminate moving Bucky trays from radiographic tables and fluoroscopic devices.

Evidence is presented to support the use of a nongrid table-top procedure for pediatric IVPs. The patient dose and image quality is compared in grid and nongrid techniques using identical film-screen systems. All projections are KUBs of children with abdominal thicknesses less than 13 cm who are involved in IVP examinations. Image quality is shown to be affected adversely beyond 13 cm. The use of the table-top method is helpful to the radiologist and technologist and beneficial to the patient.

The paper describes a method of shuttering mixed cystourethrography in patients with low volumetric rate of urination that permits one to stop urination for the period of time necessary to fill the urethra but avoiding its overload and the development of venous refluxes. The aforementioned method was tested in 29 patients with stenosis of urethra and urocyst neck and proved the possibility to obtain the clear picture of urethra below its stricture, to measure its length and diameter.

32 patients have been examined with sequential angiourography (AUS) and image subtraction, utilizing a spot-camera instead of a rapid seriograph, for the visualization of the vascular phase of the renal artery. Satisfactory results have been obtained since in 96.9% of the cases (31/32) it has been possible to obtain representation of those structures sufficient for a clinical evaluation. This technique for its low cost and simplicity of execution can therefore be proposed as a routine examination in the suspect of vascular renal pathology. This method and the more diffuse AUS with rapid seriograph offer, with respect to digital subtraction angiography (DSA), the advantage of a better nephrographic and urographic phase due to the higher quantity of contrast medium injected.

Radiation exposure to the surgeon was determined during 50 percutaneous renal stone removals. Above-table X-ray equipment with the X-ray tube in a vertical position was used. The beam was always collimated to 15 cm X 15 cm. A vertical lead screen between surgeon and X-ray tube offered protection against scatter radiation. Radiation exposure to the left hand ranged from 0.1 mSv to 4.7 mSv (average: 0.92 mSv); to the right hand from 0.1 mSv to 1 mSv for one operation (average: 0.26 mSv). Chest dose (under and outside the lead apron) was in 50 cases lower than 0.01 mSv. Radiation exposure at collar level was in 45 cases lower than 0.01 mSv and averaged 0.08 mSv in 5 cases (range: 0.05 to 0.13 mSv).

Mild caliectasis in patients with occult ureteropelvic obstruction can cause difficulties in the decision on operative or non-operative measures. In such situations diuresis renography, diuretic radionuclide urography and perfusion pressure flow studies (Whitaker test) can be very useful. Furosemide-sonography is a new, non-invasive method demonstrating functional subpelvic obstruction. Standardised conditions before and after application of furosemide are necessary. This new diagnostic method is demonstrated based on a evaluation in 22 patients presenting radiological evidence of minor ureteropelvic obstruction.

In these times of rapid advances in radiographic imaging, intravenous urography should be performed in an optimal way. The urographic examination should involve consultation between the referring physician and the radiologist. Necessary patient information should be accessible. McClennan said "patient selection for urographic studies should be efficacious with the radiologist exerting appropriate control so that the urogram is truly a consultative imaging service integrated into the total patient management." We share this view, and it is an extension of the philosophy of practice emphasized by other leaders in uroradiology. Cost containment, new imaging technologies, risk/benefit considerations, and evolving patterns of patient care have had a significant influence on genitourinary tract imaging. In addition, current debate about contrast media, digital radiography, efficacy, and utilization will undoubtedly have an influence on imaging during the next decade. Utilization of intravenous urography has decreased significantly in the past 15 years. Our volume of examinations has declined approximately 50% since 1970. This decline in our practice is attributed to several complex factors such as previous overutilization of screening urography for hypertension; the impact of US and CT for evaluation of obstruction, retroperitoneal disease (adenopathy and fibrosis), renal failure, and renal masses; concern about contrast medium-induced renal failure; and fewer repeat studies because of improved quality of intravenous urography in general radiology practice. In addition, overutilization of urography in patients with hematuria, prostatism, history of urinary tract infection, etc, continues to be debated in the medical community. In our integrated group practice, we have also observed overutilization of "high-tech" procedures in lieu of urography for evaluation of suspected urinary tract disease. Swings of the pendulum are inevitable in diagnostic imaging because of evolving technology and the art of medical practice. Although some differences of opinion about the details of urographic technique and indications for urography may exist, most would agree on the philosophy of producing a high-quality urographic examination. That philosophy focuses on producing the highest quality examination in each patient so that a diagnosis of normal or abnormal can be made accurately and confidently. Failure to demonstrate the entire urinary tract is a common cause of diagnostic error and one that can largely be eliminated by careful attention to the technical details of the examination.

Our experiences indicate that the 'urograph', in combination with the 100-mm sheet-film camera, represents an x-ray apparatus that is just about optimally suited to the needs of urologic x-ray diagnoses. Only in extreme situations is the range of movement of the tabletop in the direction of the head and feet insufficient. A major advantage of the camera, and the one which, above all, plays a decisive role in the urologic x-ray diagnosis of children, is that the amount of radiation can be reduced by about 1/2 to 1/3 that necessary with conventional photo techniques. Through optimal use of the apparatus, considerable time and personnel can be saved. In view of the additional fact that kidney angiographs can be performed with this apparatus, in combination with the 100-mm camera, with minimal problems, minimal time, and minimal stress for the patient, x-ray-video amplifier photography represents an important addition to urologic x-ray examination possibilities that today we can no longer afford to do without.

The use of intraoperative radiography for localization of small renal calculi has been a valuable adjunct to surgery. Unfortunately, because of the considerable time required for mobilization of the kidney, the development of x-ray films and the not infrequent need for repeat exposures, considerable time can be added to the operation. We have found that the use of Polaroid film can give high-quality intraoperative radiographs. The main advantage of Polaroid film over the standard Kodak kidney film is that the film is developed in the operative suite and, in most cases, requires less than one minute.

In this perspective study the authors examined 57 patients to evaluate diagnostic accuracy of sequential angiourography (AUS) using spot-camera and image subtraction for the visualization of the vascular phase of the renal arteries. All the subjects underwent surgery or follow-up with other clinical and radiological methods. The results obtained with this technique, of low cost and simple execution, were satisfactory: accuracy 98%, sensitivity 100%, specificity 98%.

With the patient supine the long axis of the kidney has an average 16 deg. (SD 5,8 deg.) distal ventral inclination to the horizontal table top plane. A 100 cm long wedge shaped pad with a 16 deg. angle to be placed under the patient's shoulders and back during urography to bring the long axis of the kidney parallel to the horizontal plane is described. This method gives simultaneous good visualization of both the upper and lower outlines of the kidneys on a single tomographic cut.

The size of a kidney, as measured on a urogram, is a sensitive indicator of renal damage in a child with urinary tract infection and renal surface area correlates well with glomerular filtration rate. Sequential measurements can be invaluable in evaluating the efficacy of a regimen of treatment. A system utilizing a personal microcomputer has been developed to facilitate the measuring procedure and the handling and analysis of data.

T-grain film is claimed to give significantly improved image quality, allowing the use of faster screens without loss of quality and thus reducing radiation dose. We tested this claim for two systems. In each case comparison was made with our usual screen-film combination, Agfa Curix RP1 film with Kodak Xomatic Regular screens (a nominally 200 speed system). The systems tested were Kodak TMatG in Kodak Lanex Medium screens (300 speed) and Agfa STG in Kodak Lanex Regular screens (400 speed). The Agfa STG-Lanex Regular system performed less well than the standard system for intravenous pyelograms (IVPs), bones and soft-tissue detail. Its speed advantage was not apparent below 70 kV. The Kodak TMatG-Lanex Medium system was better than the standard system for IVPs but not as good for bones. It gave virtually no speed advantage below 90 kV. Kodak T-grain film in a medium-speed, rare-earth screen was found to be better than the standard system for IVPs. Agfa T-grain film in a fast rare-earth screen was unsatisfactory for IVPs. Neither combination was as good as the standard system for bones.

The Leech-Wilkinson Intra-Uterine Cannula used in hysterosalpingography has proved useful in ascending urethrography in the adult male patients. Lesions of the urethra, e.g., strictures, calculi, sinuses, diverticula and urethral tear are best demonstrated by ascending urethrography. This method does not replace voiding cysto-urethrography under physiological conditions.