Radiographic findings and hypotensive reactions in excretory urography

The radiographic findings and the hypotension patterns were reviewed in 19 patients having hypotensive reactions in routine excretory urography using ionic contrast medium. The lowest systolic blood pressure was above 80 mmHg in 10 patients while below 80 mmHg in remaining 9 patients. The urogram was unremarkable as long as the systolic blood pressure was preserved above 80 mmHg. In 2 patients, whose systolic blood pressure decreased quickly beyond 80 mmHg immediately after injection of contrast medium, the pyelogram was faint or non-visualized. On the other hand, in 4 patients, whose systolic blood pressure decreased beyond 80 mmHg in several minutes after injection of contrast medium and remained under 80 mmHg for more than 20 minutes, the nephrogram was dense and the pyelogram was faint or non-visualized. Although systolic blood pressure decreased beyond 80 mmHg, the urogram was unremarkable in 3 patients. This was due to the delayed hypotension or the short duration of hypotension.     

Radiologic investigation of renal colic: unenhanced helical CT compared with excretory urography.

OBJECTIVE: Our aim was to compare unenhanced helical CT and excretory urography in the assessment of patients with renal colic. SUBJECTS AND METHODS: Fifty-three of 70 consecutive patients with acute signs of renal colic were prospectively examined with unenhanced helical CT, which was followed immediately by excretory urography. Two radiologists who were unaware of the findings independently interpreted these examinations to determine the presence or absence of ureteral obstruction. On all CT scans that had positive findings for ureteral stones or obstruction, we looked for secondary signs of obstruction (perinephric or periureteral fat stranding, ureteral wall edema, ureteral dilatation, and blurring of renal sinus fat). RESULTS: A stone was recovered in 45 of the 53 patients, nine before and 36 after imaging. The latter 36 patients had their stones identified on CT, whereas only 24 patients had their stones identified on excretory urography. Eight patients without stone disease had normal ureters on both CT and excretory urography. Of the 45 patients who had stone disease, 26 had ureteral dilatation on both CT and excretory urography, and 36 patients who recovered a stone after CT had secondary signs of obstruction. Of the nine patients who recovered a stone before CT, three had secondary signs of obstruction. Two patients had periureteral fat stranding, ureteral wall edema, and renal sinus fat blurring. One patient had only ureteral wall edema. CONCLUSION: Compared with excretory urography, unenhanced helical CT is better for identifying ureteral stones in patients with acute ureterolithiasis. Secondary CT signs of obstruction, including renal sinus fat blurring, were frequently present even when the stone was eliminated before imaging.     

Low-dose CT urography using deep learning image reconstruction: a prospective study for comparison with conventional CT urography

Objectives:To compare the image quality of low-dose CT urography (LD-CTU) using deep learning image reconstruction (DLIR) with conventional CTU (C-CTU) using adaptive statistical iterative reconstruction (ASIR-V).Methods:This was a prospective, single-institutional study using the excretory phase CTU images for analysis. Patients were assigned to the LD-DLIR group (100kV and automatic mA modulation for noise index (NI) of 23) and C-ASIR-V group (100kV and NI of 10) according to the scan protocols in the excretory phase. Two radiologists independently assessed the overall image quality, artifacts, noise and sharpness of urinary tracts. Additionally, the mean CT attenuation, signal-to-noise ratio (SNR) and contrast-to-noise (CNR) in the urinary tracts were evaluated.Results:26 patients each were included in the LD-DLIR group (10 males and 16 females; mean age: 57.23 years, range: 33–76 years) and C-ASIR-V group (14 males and 12 females; mean age: 60 years, range: 33–77 years). LD-DLIR group used a significantly lower effective radiation dose compared with the C-ASIR-V group (2.01 ± 0.44 mSv vs 6.9 ± 1.46 mSv, p < 0.001). LD-DLIR group showed good overall image quality with average score >4 and was similar to that of the C-ASIR-V group. Both groups had adequate and similar attenuation value, SNR and CNR in most segments of urinary tracts.Conclusion:It is feasibility to provide comparable image quality while reducing 71% radiation dose in low-dose CTU with a deep learning image reconstruction algorithm compared to the conventional CTU with ASIR-V.Advances in knowledge:(1) CT urography with deep learning reconstruction algorithm can reduce the radiation dose by 71% while still maintaining image quality.     

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.     

Significance of paravertebral venous collaterals on excretory urography

The visualization of paravertebral venous collateral vessels during excretory urography may be normal when a foot vein has been injected. This finding reflects the abundant intercommunications between the caval, vertebral, and azygos venous systems and should not be mistaken for vena caval occlusion unless strong clinical suspicion of deep venous thrombosis exists.     

CT urography and MR urography

CT urography and MR urography are an evolving concept and developing technique. As the technology matures, CT urography will combine the ultimate diagnostic capabilities of intravenous urography and CT. In the near future, many intravenous urograms will be replaced by CT urography to evaluate patients with hematuria and other genitourinary conditions. MR urography currently serves as an alternative imaging technique to intravenous urography and CT urography for children and pregnant women and for patients with contraindications to iodinated contrast media.     

Significance of paravertebral venous collaterals on excretory urography

The visualization of paravertebral venous collateral vessels during excretory urography may be normal when a foot vein has been injected. This finding reflects the abundant intercommunications between the caval, vertebral, and azygos venous systems and should not be mistaken for vena caval occlusion unless strong clinical suspicion of deep venous thrombosis exists.     

Ultrasonography versus excretory urography: value in urological disease

Considerable savings in cost and some reduction in gonad dose and contrast medium allergy can be expected if excretory urography can be replaced by real-time ultrasonography as the first examination in upper urinary tract disease. For one year, all patients referred for excretory urography (UG) are first examined with real-time ultrasonography (US) to establish whether UG can be completely replaced by US, or the indications for which US should be the first examination of choice. The results in 200 consecutive patients indicate that both methods sometimes fail, but not in the same patients. A combination of the two may be unbeatable, but uneconomical. The results obtained over one year may give the answer. Hopefully studies at other centres will be initiated to increase the size of the case material.     

Detection of renal masses: sensitivities and specificities of excretory urography/linear tomography, US, and CT

A prospective blinded study of 201 patients was performed to determine the relative sensitivities and specificities of excretory urography/linear tomography (EU/LT) and ultrasound (US) for the diagnosis of renal parenchymal masses. Computed tomography (CT) was used as a standard. EU/LT permitted detection of 10% of CT-confirmed masses (cystic or solid) less than 1 cm, 21% of lesions greater than or equal to 1 cm but less than 2 cm, 52% of lesions greater than or equal to 2 cm but less than 3 cm, and 85% of lesions 3 cm or more in diameter. US permitted detection of 26% of CT-confirmed lesions less than 1 cm, 60% of lesions greater than or equal to 1 cm but less than 2 cm, 82% of lesions greater than or equal to 2 cm but less than 3 cm, and 85% of lesions 3 cm or more in size. The results confirm the relative insensitivity of EU/LT for masses less than 3 cm in diameter and of US for masses less than 2 cm. Further, they suggest that CT may have a role not only in evaluation of cases in which the urographic or sonographic results are questionable or positive, but also in confirmation of apparently negative urographic findings when clinical suspicion of a lesion is high.     

Medullary sponge kidney on axial computed tomography: comparison with excretory urography

To evaluate features of medullary sponge kidney (MSK) on computed tomography (CT), 4-mm-thick axial slices without intravenous contrast material were first made in 13 patients through 24 kidneys which showed images of MSK on excretory urograms. On CT, papillary calcifications were found in eleven kidneys. In five of these kidneys, the calcifications were not detectable on plain films. Some hyperdense papillae (attenuation value 55-70 Hounsfield units) without calcification were found in four other kidneys. Nine kidneys appeared normal. Ten of these 24 kidneys were reexamined by a second series of 4-mm-thick axial slices, 5 min after intravenous injections of 50 ml of Urografin. Images suggesting possible ectasia of precaliceal tubules were found in only four kidneys. These images appear much less obvious and characteristic on CT than on excretory urogram and do nothing more than suggest the possibility of MSK. In conclusion, the sensitivity of CT in the detection of MSK is markedly lower than that of excretory urography. In the most florid cases of the disease, CT can only show images suggesting the possibility of MSK. On the other hand, CT appears much more sensitive than plain films and tomograms of excretory urography in the detection of papillary calcifications, the most frequent complication of MSK.     

Cytogenic effects of diatrizoate and ioxaglate on patients undergoing excretory urography

Possible cytogenic alterations due to radiologic contrast medium in patients undergoing a common radiologic examination is studied. Two groups of 20 patients each were used. Group I consisted of patients undergoing excretory urography, using sodium and meglumine diatrizoate as contrast. A different agent, sodium and meglumine ioxaglate, was used with group II. Three blood samples were taken from each patient before urography, immediately after urography, and 1 week later. The frequency of sister chromatid exchanges (SCE) and chromosomal aberrations (CA) were found to increase significantly in the B samples from both groups, that of group I being higher (P less than .01 compared with P less than .05). Furthermore, these alterations were found to persist in the C samples from group I. No modification of the Proliferating Rate Index (PRI) was found. The osmolarity or other components of the contrast media studied could be involved in the process. The results indicate that ioxaglate produces less cytogenic damage than diatrizoate.     

Pediatric excretory MR urography: comparative study of enhanced and non-enhanced techniques

Our purpose was to compare the quality of ureteral imaging in pediatric patients using two different MR sequences: the non-enhanced heavily T2-weighted (W) turbo spin-echo sequence (TSE) and the gadolinium-enhanced T1W fast-field-echo sequence (T1 FFE). An experimental study on three pigs was first performed. The TSE, before and after furosemide injection, was followed by the T1 FFE sequence. The clinical study included 11 infants and 10 children. With some modifications the same MR parameters and techniques were used as in the animal study. The TSE with TR 8000 ms and TE 650 ms implied 6 radial stacks each of 40 mm thickness. The T1 FFE included TR 18 ms, TE 2.9 ms, flip angle 60 , and 50 slices with thickness 0.7 mm. After post-processing, image reconstructions qualitative and quantitative analysis were performed. Complete visualization of the ureters was achieved in 35 of 42 (83%) cases. Seventy-four percent of the ureters were completely visualized with T1 FFE compared with only 19% with TSE. Sixty-nine percent of the ureters were better imaged with T1 FFE than TSE and 21% equally well imaged. Four ureters (10%), either obstructed or due to poor renal function, were better imaged with TSE. The two sequences are complementary. Visualization of non-obstructed ureters is excellent with T1 FFE and the sequence is superior to TSE. The TSE, however, may be equal to or even better than T1 FFE in visualizing obstructed ureters or ureters draining malfunctioning kidneys. Electronic Publication     

多层螺旋CT曲面重建尿路成像技术的应用

目的 :探讨多层螺旋CT(MSCT)任意角度曲面重建 (CPR)尿路成像技术在泌尿系病变诊断中的临床应用价值。方法 :3 1例泌尿系病变患者中 ,肾盂癌 4例 ,肾盂结石 1例 ,输尿管结石 5例 ,输尿管单纯狭窄 3例 ,输尿管癌 2例 ,迷走血管压迫输尿管 2例 ,膀胱癌 2例 ,前列腺癌侵犯膀胱 1例 ,腹腔脓肿压迫输尿管 1例 ,膀胱炎 3例 ,输尿管炎 7例。 3 1例均采用 10mm层厚、层距行腹盆部MSCT容积扫描 ,获得原始横断面图像 ,采用 2 .5mm层厚、1.2 5mm层间距重叠 5 0 %重建轴面源像 ,传输至AW 4.0图像工作站 ,利用reformat软件进行尿路多平面重建 (MPR) ,获得冠状面、矢状面及任意斜面尿路图像 ,再沿尿路走行划曲线进行CPR尿路成像。采用双盲法 ,对泌尿系病变作出定位、定性诊断。结果 :3 1例CPR尿路成像成功率为 10 0 % ,图像清晰 ,均清楚地显示尿路全程及其周围组织结构。结论 :任意角度CPR技术可获得良好的尿路成像 ,CPR尿路成像可全面、直观地跟踪显示尿路全程 ,在泌尿系病变诊断方面具有独特的优势。