Gadolinium as an alternative contrast agent for diagnostic and interventional angiographic procedures in patients with impaired renal function.

BACKGROUND: The study was designed to investigate the safety and feasibility of gadopentetate dimeglumine, a gadolinium-based contrast medium, as an alternative angiographic contrast agent in patients with impaired renal function and high risk for iodinated contrast-induced nephropathy. METHODS: Gadopentetate dimeglumine was used as the radiographic contrast agent in 32 diagnostic or interventional angiographic procedures in 29 patients (59% diabetics) with severe renal insufficiency (average serum creatinine of 3.6+/-1.4 mg/dl). The average dose of gadopentetate dimeglumine was 0.34+/-0.06 mmol/kg body weight. Gadopentetate dimeglumine was used either alone (n=20) or in conjunction with carbon dioxide (n=12). RESULTS: Thirty-two angiographic procedures (24 diagnostic angiographies and 8 interventional procedures) were performed in 29 patients. For diagnostic purposes, eleven selective renal arteriographies, six angiographies of the iliac arteries and lower extremities, and seven venous angiographies of the upper extremity and central veins were performed. Interventional procedures consisted of two percutaneous transluminal renal angioplasties with stenting, four percutaneous peripheral vascular interventions, and two balloon angioplasties of a dialysis fistula. None of the patients, except one, had evidence of post-procedure contrast material-induced renal failure (increase in serum creatinine >0.5 mg/dl within 72 h) or other complications. This patient had a clinically important increase in serum creatinine level after percutaneous transluminal renal angioplasty and stenting, probably due to cholesterol embolism. Gadopentetate dimeglumine had sufficient radiographic density to allow adequate diagnostic visualization with digital subtraction equipment in all cases. CONCLUSIONS: Gadopentetate dimeglumine is an alternative and safe radiographic contrast agent for angiography and interventional procedures in patients with severe pre-existing renal impairment. In this population with high risk for contrast-induced acute renal failure, it is obviously less nephrotoxic than iodinated contrast media.     

Gadolinium-based contrast media compared with iodinated media for digital subtraction angiography in azotaemic patients.

BACKGROUND: To determine whether gadolinium-based contrast media (CM) could be used safely for angiographies in patients with renal dysfunction we investigated renal function after gadobutrol exposure and compared the results with standard iodinated CM (iohexol) in a randomized clinical study. METHODS: Twenty-one patients (aged 67+/-11 years, nine female and 12 male) with severely impaired renal function [mean serum creatinine 3.2+/-1.3 mg/dl, mean glomerular filtration rate (GFR) 31+/-16 ml/min/1.73 m(2)] who needed to have angiography because of severe peripheral vascular disease, renal artery stenosis or aortic aneurysms were randomized to receive in a blinded manner either gadobutrol (Gadovist 1.0 mmol/ml) or iohexol (Omnipaque 350) as contrast agents. GFR was measured by CM clearance (Renalyzer) at baseline and 48 h after CM administration. The primary end point was the mean change of GFR from baseline at 48 h, the secondary one the incidence of CM-induced acute renal failure, defined as a decrease in GFR of >50% from baseline within 48 h of CM administration. RESULTS: In the gadobutrol group (n = 10) we observed a statistically significant decrease in GFR of 10.6+/-13.8 ml/min/1.73 m(2) within 48 h after CM administration (P<0.05, paired t test). The incidence of CM-induced ARF amounted to 50%. In comparison, the iohexol group (n = 11) also showed a statistically significant GFR reduction of 8.7+/-8.8 ml/min/1.73 m(2) (P<0.05, paired t test), and of ARF by 45%. The percentile of differences of GFR decreases between the two groups was not significant (P = 0.70). No patient demonstrated other adverse effects of gadobutrol or iohexol administration, apart from GFR reduction. Despite the decline in GFR, no patient required haemodialysis in the 10 following days. CONCLUSIONS: In our study, gadolinium-based angiography showed no benefit over iohexol angiography with respect to preventing GFR reduction in patients with severely impaired renal function.     

Evaluation of renal intra-arterial digital subtraction angiography

A total of 68 patients with renal abnormalities and potential donors were examined by intra-arterial digital subtraction angiography (IA-DSA). Compared with the conventional angiography, the advantages of IA-DSA are reduction of volume of contrast material and rate of injection. The image quality is superior to intravenous DSA. For the potential donors, IA-DSA has the same diagnostic value as conventional angiography to depict the number and position of renal arteries. IA-DSA is an effective method for screening hypertensive patients for renovascular disease. However, conventional angiography is necessary when evaluation of smaller intra-renal branch is desired. IA-DSA would be valuable for renal recipients because of good visibility by a smaller volume of contrast material. Another advantage of IA-DSA is the reduction of examination time. Embolization can also be done in a shorter time. Renal vein is easily detected by IA-DSA. Renal vein anomalies and obstruction are diagnosed in the left side without conventional venography. Renal IA-DSA can be replaced by conventional arteriography except when the delineation of tiny arterial change is desired.     

Gadolinium as a nonnephrotoxic contrast agent for catheter-based arteriographic evaluation of renal arteries in patients with azotemia

OBJECTIVE: This study was undertaken to determine the effect of gadolinium arteriography on renal function and its diagnostic accuracy in patients with azotemia with suspected renovascular disease. METHODS: Catheter-based digital subtraction arteriographic studies with gadolinium as the contrast agent were performed on 25 occasions in 21 consecutive patients with azotemia to evaluate renal arterial circulation. Gadolinium (gadodiamide, 287 mg/mL) was the only contrast used in these studies. Quantities of gadolinium administered ranged from 40 to 264 mL (mean +/- standard deviation, 124 +/- 74 mL). Serial determinations of renal function were performed in all patients. Arteriography was undertaken 20 times after prior renal revascularizations: seven times as a routine postoperative follow-up study, nine for increasing azotemia, three for worsening hypertension, and once for evaluation of a known renal artery stenosis in patient with an abdominal aortic aneurysm. Three additional arteriograms were performed as part of an evaluation for suspected renovascular hypertension. The two remaining arteriograms were performed in patients with known aortic aneurysms in whom renal artery stenosis was suspected. RESULTS: No adverse changes in renal function followed gadolinium arteriography. Prearteriography serum creatinine values ranged from 1.6 to 9.1 mg/dL (3.0 +/- 1.4 mg/dL), compared with postangiography values that ranged from 1.2 to 8.4 mg/dL (2.9 +/- 1.3 mg/dL). Comparable blood urea nitrogen values ranged from 23 to 71 mg/dL (40.1 +/- 13.5 mg/dL) before arteriography and from 21 to 68 mg/dL (36.5 +/- 13.3 mg/dL) after arteriography. All 38 renal arteries evaluated were adequately imaged. First-order and second-order branchings were well visualized on selective renal studies. Twenty-one renal arteries showed no abnormalities, including six of seven reconstructed arteries subjected to early postoperative evaluation. Twelve renal arteries manifested significant disease, including seven with stenoses and five that had become occluded. Among five additional renal arteries studied, two exhibited obstructing thrombus, two had dissections, and one had a kinked aortorenal bypass graft. CONCLUSION: Catheter-based arteriography in patients with azotemia with gadolinium as a contrast agent is a safe and effective means to evaluate the renal arterial circulation. The preferential use of gadolinium in lieu of nephrotoxic iodinated contrast agents for catheter-based arteriography in patients with azotemia is supported by this experience.     

Digital subtraction angiography for evaluating patients with renal carcinoma

Intravenous digital subtraction angiography has been performed on 39 patients with renal carcinoma. In 19 patients (group 1) imaging of the renal arteries was done following injection of 40 cc intravenous contrast medium through an antecubital vein. In 20 patients (group 2) 40 cc intravenous contrast medium were injected through a femoral vein and digital subtraction imaging of the inferior vena cava was obtained. In 12 of these patients the renal arteries also were visualized from the same injection of contrast medium. Intra-arterial digital subtraction angiography of the renal arteries also was done in 5 patients in group 2. Intravenous digital subtraction angiography satisfactorily demonstrated main renal arterial anatomy in 29 of 35 patients (83 per cent) over-all but failed to delineate the renal mass in most cases. Excellent visualization of the inferior vena cava was obtained in all 20 patients in group 2. Intraarterial digital subtraction angiography yielded an accurate diagnosis of renal carcinoma in all 5 patients with minimal doses of contrast medium. We conclude that intravenous digital subtraction imaging combined with computerized tomography scanning or ultrasonography yields satisfactory diagnostic and anatomical information for most patients with renal carcinoma.     

Usefulness of digital subtraction angiography for diagnosis of renal tumours

DSA (digital subtraction angiography) is a new, highly effective method for visualization of kidney vascular system. By means of a digital subtraction angiography unit the image of bones and soft tissues is blotted out, and a subtractive picture of contrasted vessels alone emerges. Intra-arterial DSA is a less invasive and more comfortable method when compared to conventional angiography. Only 2–4 ml of contrast medium is administered, thinner catheters being employed at the same time. The examination can also be performed through intravenous administration of contrast medium. The DSA unit Angiotron CMP was installed at the Department of Radiology, Military Medical Academy of Łódź, in 1984. In the present material a diagnostic DSA investigation was performed in 22 patients with renal tumours. In 21 of them the tumour was correctly diagnosed on grounds of pathological vascularization and the result was dubious in only 1 patient with benign tumour.     

代谢综合征患者肾动脉狭窄的SCTA与DSA对比研究

目的探讨代谢综合征(MS)患者中肾动脉狭窄的发生率及无创性筛检的必要性与可靠性。方法45例MS患者预行肾动脉螺旋CT血管造影(SCTA),对所检出的14例肾动脉狭窄者行肾动脉数字减影血管造影(DSA)对照,并对SCTA及DSA结果进行对比分析。结果45例MS患者中SCTA显示肾动脉正常31例,其余14例患者存在单侧或双侧肾动脉狭窄,DSA对照显示肾动脉正常6条,肾动脉狭窄22条,与SCTA显示的情况基本符合。结论MS患者中肾动脉狭窄的发生率约31.1%,对可疑患者应常规予以肾动脉SCTA检查。     

Use of digital subtraction fluorography in screening for coronary artery disease in patients with chronic renal failure

The diagnosis of coronary artery disease remains a major problem in patients with end-stage renal disease. Screening with conventional noninvasive techniques is limited by the poor exercise capacity of these patients. This study evaluated the accuracy of digital subtraction fluorography in detecting coronary calcification as a noninvasive, nonexercise screening test for coronary artery disease. Eighty-six patients under evaluation for renal transplantation and considered at increased risk of coronary artery disease were studied by coronary arteriography and digital subtraction fluorography for coronary calcification. Significant coronary disease (greater than or equal to 50% obstruction in at least one vessel) was present in 36 (42%) patients. The detection of coronary calcification by digital subtraction fluorography had a sensitivity of 78% and a specificity of 66%. The probability of disease being present in the absence of coronary calcification in this group was 18%. The detection of coronary calcification by digital subtraction fluorography appears to be a satisfactory and inexpensive screening test in this setting.     

Intra-arterial digital subtraction angiography for children with idiopathic renal bleeding: a diagnosis of nutcracker phenomenon

Among children with asymptomatic hematuria, 28 cases of nonglomerular idiopathic renal bleeding were subjected to this series of study. Intra-arterial digital subtraction angiography (DSA) and/or renal venography were performed to investigate the hematuria of unknown etiology. DSA clearly demonstrated the entrapment of the left renal vein (LRV), or nutcracker phenomenon in the majority of our patients (22 out of 28 cases): obstruction of the LRV with well-developed collaterals were found in 8 cases, and in the remaining 14 cases, various degrees of LRV compression were demonstrated. A characteristic real-time DSA image was the congestion of LRV associated with collaterals and/or intermittent venous flow at the compressed segment of LRV. The pullback pressures from LRV to the inferior vena cava (IVC) that were obtained from 5 of these patients demonstrated gradients of 2 mmHg (3 cases), 3 mmHg (1 case), and 5 mmHg (1 case), respectively. The parallel application of ultrasonography has given positive signs for LRV entrapment, although they have not necessarily coincided with the existing criteria of nutcracker phenomenon. Considering the high incidence of LRV entrapment among children with nonglomerular hematuria, most nutcracker phenomenon should be diagnosed on ultrasonography. However, intra-arterial DSA is an important tool to establish the disease entity and ultrasonic criteria.     

低注射速率、低剂量对比剂3D-DSA脑血管造影

目的探讨低注射速率、低剂量对比剂3D-DSA脑血管造影的的可行性。方法连续收集疑似动脉瘤患者51例行3D-DSA脑血管造影,选择DynaCT 5sDSA成像,均采用非离子型对比剂碘普罗胺注射液(370mgI/100ml),导管尖端均位于平枢椎水平,按对比剂注射速率随机分为A组(1.5ml/s,n=18)、B组(2.0ml/s,n=18)、C组(3.0ml/s,n=15)。计算C臂锥形束CT轴位图像颈内动脉岩段(C2段)和眼段(C6段)、大脑中动脉水平段(M1段)、大脑前动脉水平段(A1段)的噪声、SNR及CNR,由2名医师对连续减影图像、VR及MIP重组图像的图像质量进行评分后行统计学分析。结果 B、C组与A组噪声的差异均无统计学意义(P均0.05)。A组与B组比较,M1、A1段的SNR、CNR差异均有统计学意义(P均0.05),C2、C6段SNR、CNR差异均无统计学意义(P均0.05);A组与C组比较,C2、C6、M1及A1段的SNR、CNR差异均有统计学意义(P均0.05)。3组间大脑中动脉、大脑前动脉连续减影图像及VR、MIP图像的图像质量主观评分差异均无统计学意义(P均0.05),均可充分显示颅内动脉瘤情况。结论 3D-DSA脑血管造影中实施个性化低注射速率、低剂量对比剂注射方案可行,能够降低患者碘摄入量及血管破裂出血风险。     

Intravenous digital subtraction angiography in the evaluation of potential renal donors

Of 65 surgically removed donor kidneys intravenous digital subtraction angiography demonstrated accurately the number of renal arteries in 58 (89 per cent). All accessory vessels missed at digital subtraction angiography were small and their presence did not interfere with successful transplantation in those donated. Of 50 surgically removed donor kidneys examined with conventional aortography only before the routine use of intravenous digital subtraction angiography the number of renal arteries was demonstrated accurately in 46 (92 per cent). Intravenous digital subtraction angiography offers advantages over conventional aortography, including most importantly the routine performance on an outpatient basis, and decreased film cost and examination time. Although the accuracy of conventional aortography (92 per cent) in detecting the number of renal arteries is slightly greater than that for intravenous digital subtraction angiography (89 per cent), the advantages of the digital examination justify its use as the initial examination for the potential renal donor. Conventional aortography can be reserved for use in patients with equivocal or technically inadequate digital examinations.     

Screening for transplant renal artery stenosis in hypertensive recipients using digital subtraction angiography

Digital subtraction angiography was used in 10 renal allograft recipients with sustained hypertension after transplantation to detect transplant renal artery stenosis. Recipients with end-to-end vascular anastomoses were visualized adequately in the anteroposterior projection. Two cases of transplant renal artery stenosis were identified by digital subtraction angiography and then verified by catheter angiography. Patients with end-to-side vascular anastomoses may require additional oblique projections. Digital subtraction angiography is a safe, noninvasive and cost-effective screening procedure to diagnose transplant renal artery stenosis in most recipients. Catheter angiography can be applied more selectively to those recipients with stenosis observed by digital subtraction angiography or when more detailed imaging is required.     

Use of gadolinium as an intraarterial contrast agent in digital subtraction angiography of the cervical carotid arteries and intracranial circulation. Technical note

Patients with renal insufficiency or other contraindications to iodine-based contrast agents present a significant management dilemma when conventional arteriography is required. The authors describe the use of gadolinium as an alternative contrast agent for arterial digital subtraction (DS) angiography of the cervical carotid arteries (CAs) and intracranial circulation. Three patients with renal insufficiency presented with symptoms of ischemic cerebrovascular disease and inconclusive noninvasive imaging studies, which necessitated conventional angiography. Traditional transfemoral catheterization of the cervical CAs was performed and DS angiographic studies were obtained using gadolinium as an intraarterial contrast agent. In one case, selective arteriographic examination of the internal carotid arteries and vertebrobasilar system was performed as well. High-quality, diagnostic images essentially indistinguishable from routine angiographic studies were obtained in all cases. No patient suffered a complication related to the use of gadolinium, and no patient demonstrated worsened renal function after the procedure. In the setting of a contraindication to iodine-based contrast agents, gadolinium represents an important alternative contrast material that allows for excellent visualization of the cervical CAs and intracranial circulation.     

Duplex ultrasound imaging with an ultrasound contrast agent: the economic alternative to CT angiography for aortic stent graft surveillance

The use of endovascular stent graft repair for aortic aneurysmal disease has become increasingly common, with the added requirement for close postoperative surveillance to detect the presence of endoleaks or graft migration. The most commonly used technique for surveillance is computed tomography (CT) angiography, with the need for intravenous contrast posing 1 limitation in those patients with renal dysfunction and the cost of this testing presenting an economic limitation. Early results of duplex imaging in the authors' Vascular Laboratory using an intravenous ultrasound contrast agent have shown sensitivity and specificity equivalent to those of CT angiography, with no evidence of any related morbidity. They have evaluated the cost effectiveness of using duplex ultrasound imaging as the primary surveillance technique for postoperative follow-up in aortic stent graft patients. Surveillance protocols now require that 8 follow-up examinations be performed in the first 3 years after stent graft placement. The charges for CT angiography in their institution average 2,779 dollars per study, for a 3-year total of 22,232 dollars per patient. The charges for aortic duplex ultrasound average 525 dollars per study, with a 3-year total of 4,200 dollars per patient. Adding the cost of routine abdominal radiographs to confirm stent graft position (147 dollars per study) would bring this 3-year total to 5,376 dollars, a savings of 16,856 dollars per patient. For every 100 patients who are followed up after stent graft placement, this represents a 3-year savings of more than 1.6M dollars. Promising early results of duplex ultrasound imaging with an intravenous contrast agent show sensitivity and specificity equivalent to those of CT angiography in detecting aneurysm size and graft endoleaks or other hemodynamic abnormalities. If these results can be demonstrated in larger patient series, this technique should become the method of choice for stent graft surveillance, for it offers very significant economic advantages and avoids the complications of intravenous contrast-induced renal dysfunction.     

The use of gadolinium chelates as an alternative radiographic contrast agent for use with flat panel detector angiography

Gadolinium chelates can be utilized as a fluoroscopic contrast agent when iodinated contrast is contraindicated. However, the nephrotoxicity of gadolinium at radiographic doses limits its role as fluoroscopic contrast. Gadolinium chelate-enhanced digital subtraction angiography (DSA) is particularly limited by the kV of DSA, where gadolinium chelates are relatively more radiolucent. Flat panel detectors improve conspicuity of gadolinium chelates during DSA and should be employed where possible.     

Intravenous digital subtraction angiography in the assessment of patients for carotid endarterectomy

Preoperative intravenous digital subtraction angiography (IV DSA) was compared with the operative findings in 54 patients who underwent a total of 57 carotid endarterectomies, to evaluate the accuracy of preoperative IV DSA in predicting the lesion found at surgery. Four studies early in the series were technically unsatisfactory, leaving 50 patients with 53 procedures for evaluation. Severe carotid artery stenosis was accurately predicted in all cases. Deep ulceration in the absence of severe carotid stenosis was reliably shown by IV DSA, although it was not reliably demonstrated by either IV DSA or carotid angiography if severe stenosis was also present. As severe carotid stenosis or deep ulceration are the major radiological indications for carotid endarterectomy, the authors have found that technically satisfactory IV DSA is an adequate preoperative imaging technique.