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Differences in effective dose estimation from dose-area product and entrance surface dose measurements in intravenous urography.

In this study, measurements of dose-area product (DAP) and entrance surface dose (ESD) were carried out in a sample of 25 adult patients who underwent intravenous urography (IVU). These measured quantities were used to estimate the effective dose E from the IVU examination, a quantity closely correlated to radiation risk. Estimating E involves the use of conversion coefficients that have been determined for specific X-ray views in a mathematical phantom. These are obtained under conditions which are not usually met in clinical practice. As a result, the E estimates using the two different measurable quantities can be quite different. Analysis of the calculation procedure suggests that the E estimate using the DAP measurements, in addition to being more practical, could be more accurate than using ESD measurements, as DAP is sensitive to the X-ray field size settings. Furthermore, it is shown that in the absence of the appropriate equipment, a reliable E estimate can be obtained from the ESD calculated using the exposure data for each X-ray view.

Adult↗

Medullary rays. Visualization during excretory urography.

The medullary rays are well-defined anatomic structures consisting of bundles of renal tubules which form in the renal cortex and continue through the renal medulla as the medullary striations. These structures are occasionally visualized during excretory urography in abnormal physiologic states characterized by tubular stasis and hyperconcentration of contrast material. Under these conditions, fine striations are visualized which correspond in position and orientation to these structures. The work of others has shown that in tubular stasis, contrast material is hyperconcentrated in the tubules. On microradiography in normal and obstructed kidneys, the highest concentrations of contrast material are seen in the lumen of collecting ducts. Lastly, retrograde injection of contrast material into the medullary rays produces a roentgen image similar to our illustrated cases.

Humans↗

The application of fast screen-film systems to excretory urography.

Rare earth and barium fluorochloride screen-film combinations of different relative speeds were compared to conventional calcium tungstate systems in patients undergoing excretory urography under controlled conditions. Radiographs were ranked by subjective impressions of detail, contrast, mottle, motion unsharpness, overall quality, and acceptablility. Compared to a medium speed calcium tungstate screen/film combination (assigned a speed of 1), screen-film systems in the 2-5 speed range offered improvement in overall quality due to diminished respiratory motion unsharpness at the cost of some loss of detail and increase in mottle. Other advantages and disadvantages of fast screen-film systems are discussed.

Humans↗

Visualization of the medullary rays on excretory urography in experimental ureteric obstruction.

Excretory urography occasionally delineates striations of alternating density in the renal parenchyma. Experimental observations on a dog model of ureteric obstruction show that the dense striations have the same dynamic alterations as the obstructive nephrogram. They become progressively more dense to a plateau and then fade with relief of obstruction. Previous obstruction is shown to facilitate visualization of the striations presumably by having dilated the tubules. Previous obstructive episode, previous symptoms, or chronic obstruction were present in each of the clinical cases collected which show a similar striation pattern. We conclude that the dense striations represent shadows produced by hyperconcentrated contrast material which has accumulated in dilated collecting ducts or groups of ducts within the medullary rays.

Acute Disease↗

Nonutility of routine prone filming in adult urography.

The relative value of prone and supine filming in excretory urography was prospectively evaluated in 100 unselected, adult, high-dose urograms. The supine radiographs were superior or equal to prone radiographs in all cases. Significant findings were limited to the supine radiographs in six cases. Findings were seen on both supine and prone radiographs, but the supine radiograph was clearly better in nine cases. Major urinary structures were shown to better advantage on supine films, and the prone film was subject to radiographer error in a higher number of cases.

Adult↗

Mortality during excretory urography: Mayo Clinic experience.

In a series of 300,000 consecutive patients who underwent excretory urography between January 1, 1964 and January 5, 1982, four deaths were recorded (a mortality rate of 1.3:100,000). All four patients who died were 50 years of age or older, all had a history of some type of hypersensitivity, all had a respiratory component to the reaction, all received a 1 ml test dose and had no reaction, and none had received a prior injection of contrast medium. The mortality rate in this series (1:75,000) is significantly lower than recently reported rates from multiinstitutional studies and is similar to the mortality rate resulting from the parenteral administration of penicillin. Differences in reported series may relate to methods of data collection, variations in patient population, and therapeutic management.

Aged↗

Visualization of the renal fascia: a normal finding in urography.

A previous study indicated that visualization of renal fascia adjacent to radiographically normal kidneys may suggest undetected renal disease. To determine the clinical significance of visualized renal fascia during excretory urography of radiographically normal kidneys, 110 normal excretory urograms were analyzed prospectively. Renal fascia was seen in 23 cases (21%). It was usually identified in short segments; average thickness of visualized fascia was 1.5 mm. The renal fascia was identified with anteroposterior nephrotomography in 17 (74%) of 23 cases. It is known that retroperitoneal inflammation or neoplasia may thicken the renal fascia but the visibility of this structure in patients without renal or retroperitoneal abnormalities has not been emphasized. Visualization of renal fascia adjacent to kidneys judged radiographically normal should not imply unrecognized renal pathology.

Adolescent↗

Iohexol for excretory urography: a comparative study.

A new iodinated nonionic contrast agent (Iohexol) was compared to an ionic contrast agent (renografin 60) in a double-blind study. Fifty-five patients with normal renal function were studied for incidence of undesirable side-effects and quality of the resultant excretory urogram. No major adverse reactions occurred. Minor side-effects due to the contrast occurred more than two times as often with Renografin than when Iohexol was used. The quality of visualization of the collecting system on urography was considered excellent in 44% of the patients receiving Iohexol as compared to a 17% frequency when Renografin was used.

Adolescent↗

Iopamidol: new, nonionic contrast agent for excretory urography.

Iopamidol, a new, nonionic contrast agent, was evaluated in 18 patients undergoing excretory urography. None of the 18 patients experienced any side effects or adverse reactions. No abnormalities were noted in serum chemistries, complete blood cell counts, urinalyses, or electrocardiograms. The half-life of iopamidol in 17 patients with normal renal function was 2.5 hr. The urograms were judged to be of good or excellent quality in 15 of 16 patients using doses of 200 and 250 mg l/kg of iopamidol. Two patients who were studied using a dose of only 120 mg l/kg had urograms rated poor. Fifteen iopamidol urograms (mean iodine dose, 17.4 g) were compared in a blind fashion with 15 meglumine diatrizoate studies (iodine dose, 29 g). No qualitative difference could be detected between the two groups of urograms. Iopamidol may provide equal-quality diagnostic studies with a lower iodine dose and perhaps greater safety than the currently used ionic agents.

Adult↗

Renografin-60 for urography: effect on serum electrolytes and proteins in adults.

A prospective study was done on 27 adults to assess the changes in serum electrolytes and proteins induced by bolus administration of 100 ml of the ionic contrast medium diatrizoate meglumine and sodium (Renografin-60) for IV urography. Statistically significant changes in serum sodium, chloride, potassium, calcium, bicarbonate, phosphate, total proteins, and albumin were shown at 5 min postinjection. The mean percentage decreases were sodium 2%, chloride 2%, potassium 9%, calcium 13%, bicarbonate 9%, phosphate 10%, and proteins 15%. A mean 3% increase in serum osmolality was observed. By 30 min, sodium and chloride levels had returned to baseline; potassium, calcium, and albumin values were incompletely recovered; bicarbonate was not significantly changed from 5 min; and phosphate values continued to decrease. An in vitro dialysis experiment in which different volumes of Renografin-60 were dialysed against an electrolyte solution (pseudoserum) produced a dilutional factor of 5 to render a given volume of the contrast isoosmotic with plasma. The observed changes from the baseline values of the electrolytes and proteins up to 10% are therefore assumed to be due to hemodilution resulting from movement of fluid from the extravascular to the intravascular compartment. This study confirms alterations in serum levels of several electrolytes after the use of ionic contrast media beyond simple hemodilution. Although these changes appear not to be clinically significant in this investigation, the alterations in potassium and calcium may contribute to arrhythmias, particularly when hypokalemia or hypocalcemia preexists.

Adolescent↗

Ectopic ureterocele without ureteral and calyceal dilatation (ureterocele disproportion): findings on urography and sonography.

Eight infants and children (six girls) were seen over a 13-year period with duplex collecting systems and ectopic ureteroceles. In each, there was striking dissimilarity in size between the large ureterocele and its diminutive ureter and calyces. The upper moiety did not function and, except for the ureterocele, the indirect urographic and direct sonographic signs of duplication were absent or subtle. We call this entity ureterocele disproportion. Seven patients presented with urinary infection and one was found to have hydronephrosis of a dilated lower moiety in utero. Five had ipsilateral lower-pole reflux, which ranged in degree from 3 to 5 (on a scale of 1-5). Two had bilateral duplication; one of these had a typical contralateral ectopic ureterocele. The diagnosis of ureterocele disproportion was strongly suggested by urography and sonography and was confirmed at cystoscopy by direct puncture of the ureterocele and opacification of the upper moiety. All had surgery. The approach varied and depended on the status of the lower moiety and the contralateral kidney. One had incision of the ureterocele only. Five with lower-pole reflux had excision of the ureterocele and ipsilateral common-sheath reimplantation.

Child, Preschool↗

Reducing the radiation dose during excretory urography: flat-panel silicon x-ray detector versus computed radiography.

OBJECTIVE: The purpose of the study was to examine the possibilities for reducing radiation exposure in uroradiology using digital flat-panel silicon X-ray detector radiography. We compared the subjectively determined image quality of abdominal radiographs and urograms obtained on a digital flat-panel detector radiography system with those obtained on a computed radiography system. SUBJECTS AND METHODS. Fifty patients who had a clinical indication for urography underwent unenhanced abdominal imaging that was alternately performed using flat-panel silicon X-ray detector radiography or computed radiography. For patients who required a second radiograph with contrast medium, the examination modality was changed to avoid exposing the patients to excess radiation. The images obtained on flat-panel X-ray detector radiography were obtained at half the radiation dose of the images obtained on computed radiography (800 speed vs 400 speed). The resulting 50 pairs of images were interpreted by four independent observers who rated the detectability of structures of bone and the efferent urinary tract relevant to diagnosis and compared the image quality. RESULTS: At half the radiation dose, digital flat-panel X-ray detector radiography provided equivalent image quality of the liver and spleen, lumbar vertebrae 2 and 5, pelvis, and psoas margin on abdominal radiographs. The image quality obtained with digital flat-panel X-ray detector radiography of the kidneys, the hollow cavities of the upper efferent urinary tract, and the urinary bladder was judged to be statistically better than those obtained with computed radiography. CONCLUSION: With half the exposure dose of computed radiography, the flat-panel X-ray detector produced urograms with an image quality equivalent to or better than computed radiography.

Diagnosis, Computer-Assisted↗

CT urography of urinary diversions with enhanced CT digital radiography: preliminary experience.

OBJECTIVE: The purpose of this study was to determine if 3D-rendered CT urography (CTU) depicts both normal and abnormal findings in patients with urinary diversions and if the addition of contrast-enhanced CT digital radiography (CTDR) improves opacification of the urinary collecting system. MATERIALS AND METHODS: Thirty CTU and contrast-enhanced CTDR examinations were performed in 24 patients who underwent cystectomy for bladder cancer. Indications for evaluation included hematuria, tumor surveillance, or suspected diversion malfunction. All examinations were evaluated without knowledge of the stage or grade of a patient's tumor and were compared with the clinical records. Opacification of the urinary collecting system was evaluated with 3D CTU alone, contrast-enhanced CTDR alone, and combined CTU and CTDR. RESULTS: Nine abnormalities were identified including distal ureteral strictures (n = 4), vascular compression of the mid left ureter (n = 1), scarring of the mid right pole infundibulum (n = 1), bilateral hydronephrosis and hydroureter (n = 1), urinary reservoir calculus (n = 1), and tumor recurrence invading the afferent limb of the neobladder (n = 1). Eight of the nine detected abnormalities were surgically or pathologically confirmed. All abnormalities were identified on all three imaging techniques but were best seen on 3D CTU and enhanced CTDR images. Incomplete opacification of the urinary collecting system occurred in 17 patients with CTU alone, 12 patients with contrast-enhanced CTDR alone, and nine patients with combined CTU and contrast-enhanced CTDR. Compared with CTU alone, the combined technique of 3D CTU and contrast-enhanced CTDR improved opacification by a statistically significant difference (p = 0.037). CONCLUSION: CTU with 3D rendering can accurately depict both normal and abnormal postoperative findings in patients with urinary diversions. Adding enhanced CTDR can improve visualization of the urinary collecting system.

Adult↗

[Diagnosis of ureteral calculi using ultrasonography, intravenous urography and unenhanced helical computed tomography].

INTRODUCTION: The pain in the loins is usually the consequence of renal colic caused by small ureteral calculi. ULTRASONOGRAPHY: Ultrasonography is an efficient tool in the detection of calculi in the pyelocalyx system, but it may not be sufficient for the area of renal pelvis and ureter, as wll as for the ureter and the ureterovesical junction. INTRAVENOUS UROGRAPHY: Radiolucent stones, dilatation of the ureter and of the pyelocalyx system were identified on the urogram, which are common signs of ureter calculosis. Defects in the contrast can be caused by blood clots and papillary or malignant tumors of the ureter, thus causing a differential diagnosis problem. UNENHANCED HELICAL COMPUTED TOMOGRAPHY: Noncontrast spiral CT is useful for detection fo calculi as small as 3mm. It can identify their localization and size without enlargements. The primary and secondary CT signs also confirm the established diagnosis. CONCLUSION: The noncontrast spiral CT is a highly precise method for assessment of kidney pain. It is a realiable and rapid diagnostic modality for the detection of urinary stones which differentiates them from blood clots, tumors, air and other factors which create a differential diagnosis problem.

Humans↗

Kidney split function in children. A comparative study between renography and planimetry from urography.

The suitability of the background-subtracted renogram as a method for separate kidney function in children was evaluated by comparison with planimetry of the individual renal parenchymal area measured from urography. In different groups of renal disorders the total kidney function as reflected by the glomerular filtration rate has been compared with the sum of right and left renal parenchymal areas. The percentage side distribution of kidney function estimated from the renogram combined with measurements of total glomerular filtration rate has been correlated to individual renal parenchymal area. A good correlation was found for both total and separate measurements. A moderate scatter around the regression lines has to be taken into consideration when kidney function is judged from planimetry. A highly significant correlation was observed between renography and planimetry for the percentage distribution of kidney function, indicating that both methods are well suited for determining the side distribution of kidney function. For calculation of individual kidney function, combination of renography and 51Cr-EDTA-clearance offers a reliable method with a modest dose of irradiation.

Adolescent↗

Abdominal ultrasound versus intravenous urography in the evaluation of infravesically obstructed males.

In a prospective study intravenous urography (IVP) and abdominal ultrasonography (US) were compared in 100 consecutively admitted male patients with symptoms of infravesical obstruction. No pathology was found in 67 patients on IVP and in 61 patients on US. Both modalities disclosed 5 bilateral, 4 unilateral hydronephroses and one patient with contracted kidneys. IVP found 7 renal masses: one solid tumour, 2 "possibly solid" tumours and 4 "possibly cysts", whereas US found one solid tumour and 16 cysts. Both modalities detected 3 kidney stones, 5 bladder stones and 3 bladder tumours. It is concluded that "imaging" of the urinary tract is only indicated in cases of haematuria, elevated creatinine, history of renal calculous disease and other clinical suspicion of upper urinary tract disease. It is further concluded that US is preferable to IVP in this patient category due to (1) better characterization of renal masses, (2) the possibility of investigating the liver and the retroperitoneum in the same setting, (3) better evaluation of the prostate with respect to size, (4) better evaluation of the bladder, and (5) last but not least for economical reasons. However, bone metastases will be missed.

Humans↗

Unenhanced spiral CT in acute ureteral colic: a replacement for excretory urography?

OBJECTIVE: To compare the usefulness of unenhanced spiral CT (UCT) with that of excretory urography (EU) in patients with acute flank pain. MATERIALS AND METHODS: Thirty patients presenting with acute flank pain underwent both UCT and EU. Both techniques were used to determine the presence, size, and location of urinary stone, and the presence or absence of secondary signs was also evaluated. The existence of ureteral stone was confirmed by its removal or spontaneous passage during follow-up. The absence of a stone was determined on the basis of the clinical and radiological evidence. RESULTS: Twenty-one of the 30 patients had one or more ureteral stones and nine had no stone. CT depicted 22 of 23 calculi in the 21 patients with a stone, and no calculus in all nine without a stone. The sensitivity and specificity of UCT were 96% and 100%, respectively. EU disclosed 14 calculi in the 21 patients with a stone and no calculus in eight of the nine without a stone. UCT and EU demonstrated secondary signs of ureterolithiasis in 15 and 17 patients, respectively. CONCLUSION: For the evaluation of patients with acute flank pain, UCT is an excellent modality with high sensitivity and specificity. In near future it may replace EU.

Adult↗