Renal Digital Subtraction Angiography Research Articles

Diagnostic accuracy of computed tomography angiography in detection of post traumatic renal vascular injury

ObjectivesTo evaluate accuracy of computed tomography angiography (CTA) in evaluation of post traumatic renal vascular injury. Patients and methods38 patients were presented with post traumatic intermittent or persistent hematuria. Renal CTA and digital subtraction angiography (DSA) were done for all patients. ResultsCTA demonstrated pseudoaneurysm (PA) in 30 patients (78.9%) and no vascular lesions in 8 patient (21.1%). CTA had 86.11% sensitivity and 50% specificity in detection of post traumatic renal pseudoaneurysms, CTA missed diagnosis of renal arteriovenous fistula (RAVF) in 10 patients which discovered later by DSA. ConclusionCTA with MIP as non invasive technique widely replaced renal DSA in detection of posttraumatic renal pseudoaneurysm. Renal DSA is still best modality in detection of RAVF and also has the upper hand in planning of selective renal artery embolization for the management of persistent or delayed hemorrhage from renal vessels.

Abstract No. 356 - Vascular urologic emergencies: image-guided interventions

Modern imaging studies such as computerized topography (CT) and ultrasound (US) provide an advantage for the detection of vascular urological injuries because of their speed, while digital subtraction angiography (DSA) allows for the precision needed for effective intervention. Minimally invasive techniques offer potentially lower complication rates and faster recovery times than traditional methods. This study demonstrates the role of image-guided percutaneous angiography (PCA) in such emergencies through five cases that cover the scope of neoplastic, iatrogenic, post-operative, and traumatic hemorrhages as well as priapism. PCA has revolutionized vascular interventions. DSA provides both a detailed diagnosis and an avenue for precise interventions. Embolization of pathologic vessels or hemorrhage sites can be achieved using embospheres, microcoils or gel foam. These techniques are easily extrapolated in the context of vascular urologic emergencies. One such case was a 57 year-old woman with an acute hemorrhage following surgical resectioning for renal cellular carcinoma (RCC). The postoperative period was complicated by a difficult extubation followed by acute hemorrhagic shock. The patient’s hemoglobin dropped to 6.5 as her surgical drain emptied serosanguineous fluid. After requiring 6 units of PRBC, 4 units FFP and 1 unit of platelets, IR was consulted and emergent renal DSA was performed of the left main renal artery. Subselective left inferior renal segmental branch angiography showed two small pseudoaneurysms peripheral to the site of resectioning. Microcoil embolization of the left inferior segmental branch was performed, successfully occluding perfusion to the pseudoaneurysms. The patient’s hemodynamic status soon stabilized and she was transferred out of the ICU in the following days. The case above demonstrates the application of interventional radiologic techniques in just one urologic vascular emergency. Furthermore, the methods used in the above case are not dissimilar to those used in the following case reviews, which illustrate the unique treatment options image-guided interventions can offer in the urologic setting.

Preloaded guidewires to facilitate endovascular repair of thoracoabdominal aortic aneurysm using a physician-modified branched stent graft

Branched stent grafts have been widely applied to treat complex aortic aneurysms. The technique often requires brachial or axillary approach to provide antegrade access to directional branches, which are bridged to target visceral arteries by self-expandable stent grafts. Preloaded guidewire catheterization may facilitate access into directional branches, decreasing or eliminating catheter manipulations required during this step of the procedure. We describe the use of a physician-modified branched stent graft using preloaded guidewire catheterization to treat a patient with recurrent, type III thoracoabdominal aortic aneurysm. The procedure was performed with no complications, and total operative time was 300 minutes, fluoroscopy time was 81 minutes, and iodinated contrast dose was 210 mL. Computed tomographic angiography revealed no endoleak and widely patent branches at 2 months.

Accurate geometric calibration in stepping-table digital subtraction angiography

Accurate measurements of vessel dimensions are desirable in many clinical applications. This work uses the known relative motion between X-ray source and the patient in stepping-table digital subtraction angiography (DSA) to provide an accurate geometric calibration for quantitative measurements. The method results in a calibration factor that converts the size of the object measured in pixels on the image to its size in millimetres. The main sources of error relate to: (i) the assessment of relative displacement of a structure in a series of images; (ii) patient motion throughout data acquisition; and (iii) image distortion. Error was evaluated both with a test object consisting of a large grid of ball bearings (2x2 cm spaced) and, in vivo, in five renal DSA examinations performed with identical catheters of known diameter. The calibration factor was calculated with 0.1% accuracy for the test object and at least 2% accuracy in vivo, even with breath holding and pulsatile motion. This demonstrates that the calculation of the calibration factor can be very accurate, and that the method we propose is capable of the submillimetre accuracy required for clinical studies if used in conjunction with an accurate measurement of the vessel size in pixels. In conclusion, accurate geometric measurements can be performed in stepping-table DSA, without the need for external reference objects.

Subtle renal dysfunction after radiocontrast administration in prospective renal donors: Does N-acetylcysteine have a role in its prevention?

<b>Background: </b> Radiographic contrast media (RCM) can cause a reduction in the renal function by multiple mechanisms; reactive oxygen species is one of them. Whether the reduction can be prevented by the administration of antioxidants is still debatable. <i> N</i> -acetylcysteine (NAC) has shown some benefit in patients with renal dysfunction in the prevention of radiocontrast-induced nephropathy (RCIN). <b> Materials and</b> <b> Methods</b> : We prospectively studied 95 healthy kidney donors, who were undergoing intravenous urography (IVU) followed by digital subtraction renal angiography (DSRA) with ionic, high-osmolar contrast agent for pretransplant evaluation. Patients were randomly assigned either to receive the <i> N</i> -acetylcysteine 600 mg orally twice daily (acetylcysteine group) or placebo (control group) on the day before and that of RCM administration in addition to the intravenous 0.45% saline (1 ml/kg body weight per hour) on the day and following day of the procedure. Serum creatinine, urinary enzymes <i> N</i>-acetyl β glucosaminidase (NAG), γ glutamyl-1-transferase (GGT), alanine amino peptidase (AAP), fractional excretion of sodium (FeNa) and 24-h urinary creatinine clearance were performed before and 48 h after the procedure. The levels of urinary enzymes measured after 96 h of DSRA were available in only 57 donors. Radiocontrast-induced nephropathy was defined as an increase in the baseline serum creatinine of at least 0.5 mg/dl within 48 h after injection of radiocontrast media (RCM). <b> Results: </b> Increase in the urinary enzymes (NAG, GGT and AAP) and reduction in creatinine clearance was observed in both groups after receiving the contrast media. However, the number of patients with significant increase in enzymuria (at least >50% increase above the baseline value) and mean drop in creatinine clearance was statistically not different between the acetylcysteine and control groups. <b> Conclusion:</b> Renal damage in the form of reduction in creatinine clearance and increase in urinary enzymes has been observed after administration of radiocontrast. However, clinically significant RCM-induced acute kidney injury is uncommon in patients with normal renal function. Prophylactic oral administration of the antioxidant <i> N</i> -acetylcysteine at a dose of 600 mg twice daily before and on the day of contrast administration is probably not required in patients with normal renal function.

Fibromuscular Dysplasia: An Uncommon Cause of Secondary Hypertension

Fibromuscular dysplasia is a noninflammatory vascular disease that commonly affects the distal two thirds of the renal artery and branch vessels, but occasionally involves other arteries. Progression of stenosis occurs in 16%-38% of renal arteries. Although the etiology is unknown, genetic studies suggest a relationship to the angiotensin-converting enzyme I allele. Thin, young Caucasian women without a family history of hypertension are most commonly affected. An abdominal or flank systolic-diastolic bruit is an important clue for the diagnosis. Most noninvasive screening tests are not sensitive or reproducible to be used to rule out renal artery stenosis, but digital subtraction renal angiography usually confirms the diagnosis. Percutaneous renal artery angioplasty is the treatment of choice, but may not result in normalization of blood pressure if diagnosis is delayed. Since restenosis occurs, continued follow-up is necessary.

Interobserver variability in the interpretation of renal digital subtraction angiography.

Our purpose was to analyze interobserver variability in the interpretation of renal digital subtraction angiography and to describe the main factors associated with observer discrepancies. Forty-nine cases of unilateral atheromatous renal artery stenosis of more than 60% were quantified first by local investigators in a multicenter study and then by five other radiologists. Differences between radiologists for the minimum diameter (Dmin), the reference diameter (Dref), and the percentage of stenosis of the renal arteries were analyzed. Interpretations by the local investigators were then compared with the gold standard, defined as the mean for the five radiologists. The average SD for estimation of all renal artery stenoses by all radiologists was 7% for stenosis percentage, 0.5 mm for Dmin, and 0.7 mm for Dref. Main discrepancies occurred more frequently in cases of weakly opacified renal artery stenosis and poststenotic dilatation. The observations of local investigators disagreed by more than two SDs (14%) with the gold standard for 11 of 49 cases (22%). The accuracy of digital subtraction angiography in renal artery interpretations is poor because of variations in evaluating both Dmin and Dref. Precise and reproducible methods for quantification of renal artery stenosis are required.

Nephrotoxic Risks of Renal Angiography: Contrast MediaAssociated Nephrotoxicity and Atheroembolism—A Critical Review

Renal angiography remains the “gold standard” procedure for the detection of renal artery stenosis. However, clinicians often avoid renal angiography because of fears of contrast media-associated nephrotoxicity (CM-AN) and atheroembolism. This review focuses on these potential angiographic complications, with particular emphasis, in the case of CM-AN, on clinical features, incidence, risk factors with an emphasis on pre-existing renal insufficiency and diabetes mellitus, volume of contrast media, low osmolar versus high osmolar contrast media, and prophylaxis. For atheroembolism, areas emphasized are pathology, clinical features, precipitating features, and incidence in various settings. Although the literature contains an abundance of information about CM-AN and atheroembolism, this review identified multiple areas of uncertainty regarding features of both of these complications. For example, additional studies are needed to determine the incidence of CM-AN, both asymptomatic and clinically severe, in patients with a wide range of pre-existing renal insufficiency with and without diabetes mellitus, following low volume digital subtraction renal angiography with low osmolar contrast media. In a similar manner, studies are needed with adequate postcontrast observation periods to determine the true incidence of clinically significant atheroembolism following diagnostic renal angiography and angioplasty and techniques that may modify this complication. Until further knowledge in both of these areas is available, it is difficult to precisely determine the risks of renal angiography and/or angioplasty in the azotemic patient suspected of or having renal ischemic disease using modern radiologic techniques.

Renal revascularization: indications and results.

Although the prevalence of renovascular hypertension is low, clinical criteria can select a population in which renovascular hypertension is significantly more common (prevalence of 15%). In these selected patients, it is appropriate to proceed to a screening modality to look for a significant renal artery stenosis. Choices of the noninvasive methods include captopril-enhanced renal scintigraphy, magnetic resonance (MR) angiography, and intravenous digital subtraction renal angiography (DSRA). Intraarterial DSRA or conventional arteriography may also be used to reliably detect renal artery stenosis, with the advantage that both the diagnostic and the interventional procedure can be performed at the same setting. A high percentage of a group of patients who are selected by means of clinical and arteriographic studies will benefit from revascularization. Thus, the renal artery angioplasty may be performed during the arteriogram in which the stenosis is confirmed.

Prospective analysis of strategies for diagnosing renovascular hypertension.

Renovascular hypertension is a potentially curable form of high blood pressure. However, it is unclear how best to select patients who are likely to have renovascular hypertension, what diagnostic strategy to use in these selected patients, and how to predict the hemodynamic significance of a renal artery stenosis. We determined the prevalence of renovascular hypertension in adults who exhibited suggestive clinical features. In these clinically selected patients, we then determined the test characteristics of various diagnostic and potential screening tests. Renovascular hypertension was diagnosed if correction of renal artery stenosis resulted in decreased blood pressure. Of the 66 hypertensive adults evaluated, 11 (16.7%) had renovascular hypertension. Captopril-stimulated peripheral renin activity detected renovascular hypertension with 73% sensitivity, 72% specificity, 38% positive predictive value, and 92% negative predictive value. Less optimal combinations of sensitivity and specificity were found for differential glomerular filtration rate renography, differential effective renal plasma flow renography, and selective renal vein renin ratios, each performed after a single dose of captopril. Intravenous digital subtraction renal angiography detected all patients with renovascular hypertension and was normal in 71% of patients with essential hypertension. To evaluate potential screening tests for renovascular hypertension, we calculated predictive values applied to a low prevalence population. If the observed sensitivities and specificities apply to a population with 5% prevalence of renovascular hypertension, captopril-stimulated peripheral renin would have a positive predictive value of 12% and a negative predictive value of 98%. In 16 patients with known renal artery stenosis, neither the captopril-stimulated renal vein renin ratio nor captopril-stimulated differential renography accurately predicted blood pressure response to correction of the stenosis. We conclude that clinical criteria can identify a subgroup with 16.7% prevalence of renovascular hypertension. In this high prevalence group, intravenous digital subtraction renal angiography will identify virtually all patients with renovascular hypertension, and a normal study will be sufficient to exclude renovascular hypertension. In unselected hypertensive patients, screening with captopril-stimulated peripheral renin activity may be the most useful and efficient procedure for identification of patients with renovascular hypertension. Functional tests do not accurately predict the hemodynamic significance of a renal artery stenosis.

Parametric imaging applied to renal digital subtraction angiography: Establishment of normal ranges

Parametric imaging applied to renal digital subtraction angiography: Establishment of normal ranges

A prospective analysis of the accuracy and cost-effectiveness of digital subtraction angiography for living-related renal donor evaluation.

From 1982 to 1984, we conducted a prospective study to evaluate the usefulness of i.v. renal digital subtraction angiography (DSA) for living-related donor (LRD) evaluation. Twenty-eight LRDs were evaluated with the traditional approach of intravenous pyelography (IVP) and standard catheter arteriography (SCA) (group 1). During the same period, 33 LRDs underwent renal DSA and IVP from a single i.v. contrast injection (group 2). If renal arterial imaging with DSA was considered satisfactory, no further radiographic studies were done (group 2-A, n = 23). If renal arterial imaging with DSA was not satisfactory, SCA was then obtained (group 2-B, n = 10). DSA alone accurately defined the number and location of renal arteries in 21 of 23 patients from group 2-A, and in 5 of 10 patients from group 2-B. The major limitation of DSA was in patients with multiple renal arteries; accurate imaging was obtained in only 7 of these 13 patients (54%). In group 2 overall, preoperative renal imaging was not accurate in 2 of 33 patients (6%); in both cases, an unsuspected polar artery was found at nephrectomy. The mean cost per patient of all radiographic renal imaging studies was $953.00 for group 2 and $1721.00 for group 1. These data suggest that the approach of preferentially evaluating LRDs with DSA-IVP, and obtaining SCA only if DSA yields poor visualization, is more cost-effective but not as accurate as the traditional policy of obtaining SCA and IVP in all cases.

Screening for Renovascular Hypertension

<h3>To the Editor.—</h3> The article by Dr Havey et al, entitled "Screening for Renovascular Hypertension," is a most interesting review of this subject.¹The authors have done extensive research in hopes of elucidating the role of the hypertensive intravenous pyelogram (IVP) and digital-subtraction angiography (DSA) in detecting renal artery stenosis. Their summary (Tables 2 and 3) concerning the sensitivities and specificities of the rapidsequence IVP and renal DSA finds that these numbers are similar. Moreover, the predictive values of the tests (Table 4) are essentially equal. Because of the high cost of DSA and its false-negative rate due to technical factors, the authors conclude that a well-performed, rapid-sequence IVP is the best test for detecting renal artery stenosis. Unfortunately, the authors barely address one significant problem with using the hypertensive urogram to screen for renal artery stenosis: the prevalence of bilateral lesions (p 390). As they mention, bilateral lesions

Evaluation of the prone position in digital subtraction angiography of the kidneys.

In visualizing the kidneys and renal arteries, the digital subtraction angiography (DSA) image is degraded by peristalsis and overlying bowel gas. In 25 patients we evaluated the efficacy of the prone position to counter these technical difficulties and found that the prone position offers visualization superior to the supine, especially in obese and uncooperative patients and those with abundant bowel gas. We advocate that prone imaging be included routinely in renal DSA.

Renal digital subtraction angiography--a nephrologist's view. A sensitive but imperfect screening procedure for renovascular hypertension.

Renal digital subtraction angiography--a nephrologist's view. A sensitive but imperfect screening procedure for renovascular hypertension.

Digital nephropyelography following intravenous renal digital subtraction angiography.

A 14-inch image intensifier designed for digital radiography has made feasible adjunctive evaluation of the renal parenchyma and collecting structures following intravenous digital subtraction angiography (DSA). Initial experiments with rabbits showed digital nephrography to be superior to film-based nephrotomography in terms of renal conspicuity and imaging flexibility. Preliminary experience with 30 patients undergoing DSA reaffirms the suitability of this method for the evaluation of renal anatomy and function. Only about half the amount of contrast material needed for conventional excretory urography is required.

Renal digital subtraction angiography: 100 cases.

HomeRadiologyVol. 145, No. 3 PreviousNext Renal digital subtraction angiography: 100 cases.B J Hillman, T W Ovitt, M P Capp, H D Fisher, 3rd, M M Frost, S NudelmanB J Hillman, T W Ovitt, M P Capp, H D Fisher, 3rd, M M Frost, S NudelmanB J HillmanT W OvittM P CappH D Fisher, 3rdM M FrostS NudelmanPublished Online:Dec 1 1982https://doi.org/10.1148/radiology.145.3.6755545MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Article HistoryPublished in print: 1982 FiguresReferencesRelatedDetailsCited ByJournal of Vascular and Interventional Radiology, Vol. 10, No. 4Journal of Magnetic Resonance Imaging, Vol. 8, No. 4Abdominal Imaging, Vol. 20, No. 5Radiologic Clinics of North America, Vol. 29, No. 3British Journal of Urology, Vol. 62, No. 3Urology, Vol. 30, No. 3Journal of Vascular Surgery, Vol. 2, No. 2Urologic Clinics of North America, Vol. 12, No. 4Radiologic Clinics of North America, Vol. 23, No. 2Radiologic Clinics of North America, Vol. 23, No. 2Intravenous digital subtraction angiography (IVDSA) in childrenPediatric Radiology, Vol. 14, No. 6Current Problems in Diagnostic Radiology, Vol. 13, No. 6Surgical Clinics of North America, Vol. 64, No. 1Acta Radiologica. Diagnosis, Vol. 25, No. 2Radiologic Clinics of North America, Vol. 22, No. 2Cardiovascular and Interventional Radiology, Vol. 6, No. 4-6Cardiovascular and Interventional Radiology, Vol. 6, No. 4-6Cardiovascular and Interventional Radiology, Vol. 6, No. 4-6Recommended Articles RSNA Education Exhibits RSNA Case Collection Vol. 145, No. 3 Metrics Altmetric Score PDF download