Evaluation of the vascular anatomy in potential living kidney donors with gadolinium‐enhanced magnetic resonance angiography: comparison with digital subtraction angiography and intraoperative findings

Asgari MA, Dadkhah F, Ghadian AR, Razzaghi MR, Noorbala MH, Amini E. Evaluation of the vascular anatomy in potential living kidney donors with gadolinium‐enhanced magnetic resonance angiography: comparison with digital subtraction angiography and intraoperative findings.
Clin Transplant 2011: 25: 481–485. © 2010 John Wiley & Sons A/S. Abstract: Background: X‐ray contrast arteriography has traditionally been used for pre‐operative evaluation in living kidney donors. However, magnetic resonance angiography (MRA) offers a non‐invasive alternative, which has been considered to be less accurate. This study was performed to determine whether MRA in the pre‐operative investigation of living kidney donors provides sufficient information. Methods: From December 2005 to December 2007, 173 potential live donors were evaluated in this study. Donors performed digital subtraction angiography (DSA) and those with one or more accessory arteries at least on one side recruited for further evaluation with three‐dimensional gadolinium‐enhanced MRA. Results: A total of 30 donors constituted the study population. When compared with DSA as the reference method, MRA detected 20 of 36 renal accessory arteries which indicates a sensitivity of 55.6%. The difference between MRA and DSA in identifying accessory renal arteries was significant (p‐value <0.001). Considering intraoperative findings as the standard of reference, MRA depicted correctly four of six (66.7%) accessory arteries on the transplanted kidneys. Conclusions: MRA has the advantage of avoiding exposure to ionizing radiation and is non‐invasive. These are important considerations in pre‐operative evaluation of a generally healthy donor population. However, MRA provides suboptimal accuracy in detecting small accessory arteries.     

Digital subtraction angiography for renal donor evaluation

A consecutive series of 52 living related renal donors were evaluated preoperatively by angiography. The preoperative angiographic interpretation was compared with the anatomy found at donor nephrectomy. Standard selective renal arteriography was found to be 100 per cent accurate in defining single (25) or multiple (1) renal arteries. Digital subtraction angiography (DSA) alone performed with an intra-arterial injection of contrast material was found to be 82 per cent accurate in determining the number of renal arteries. In five kidneys with multiple renal arteries, only two had the correct number of vessels identified. The errors are inherent in the DSA technology. DSA at the present time is not accurate enough to replace the standard arteriogram in the evaluation of the donor nephrectomy patient.     

Preoperative evaluation of hilar vessel anatomy with 3-D computerized tomography in living kidney donors

OBJECTIVES: Digital subtract angiography is the gold standard for anatomic assessment of renal vasculature for living renal donors. However, multidetector-row computerized tomography (MDCT) is less invasive than digital subtract angiography and provides information of kidney stones and other intra-abdominal organs. In this study, preoperative MDCT angiography results were compared with the peroperative findings to evaluate the accuracy of MDCT for the evaluation of renal anatomy. METHODS: From December 2002 to May 2007, all 60 consecutive living kidney donors were evaluated with MDCT angiography preoperatively. We reported the number and origin of renal arteries, presence of early branching arteries, and any intrinsic renal artery disease. Renal venous anatomy was evaluated for the presence of accessory, retroaortic, and circumaortic veins using venous phase axial images. The calyces and ureters were assessed with delayed topograms. The results of the MDCT angiography were compared with the peroperative findings. RESULTS: A total of 67 renal arteries were seen peroperatively in 60 renal units. Preoperative MDCT angiography detected 64 of them. The two arteries not detected by MDCT had diameters less than 3 mm. Anatomic variations were present in nine veins, five of which were detected by CT angiography. Sensitivity of MDCT angiography for arteries and veins was 95% and 93%, respectively. Positive predictive values were 100% for both arteries and veins. CONCLUSION: MDCT angiography offers a less invasive, rapid, and accurate preoperative investigation modality for vascular anatomy in living kidney donors. It also provides sufficient information about extrarenal anatomy important for donor surgery.     

Imaging modalities for renal artery stenosis in suspected renovascular hypertension: prospective intraindividual comparison of color Doppler US, CT angiography, GD-enhanced MR angiography, and digital substraction angiography

The aim of the study was to evaluate the diagnostic accuracy of Color Doppler US, CT Angiography (CTA), and GD-enhanced MR Angiography (MRA) compared with digital subtraction angiography (DSA) for the detection of renal artery stenosis in patients with clinically suspected renovascular hypertension. Fifty-eight patients with suspected renovascular hypertension were enrolled in the study. All patients underwent Color Doppler US, CTA and GD-enhanced MRA. DSA was the gold standard method for the number of renal arteries, existence and degree of stenosis, or evidence of fibromuscular dysplasia. DSA depicted 132 renal arteries, 16 stenoses, and 4 arteries with fibromuscular dysplasia. Color Doppler US failed to detect 1 main and 14 polar arteries. CTA depicted all main renal arteries and 7/16 polar arteries, but failed to detect stenosis in two accessory vessels. Likewise, MRA did not detect stenotic accessory renal arteries, depicted 9/16 polar renal arteries, but missed two main renal arteries. All methods depicted the four main renal arteries with fibromuscular dysplasia. The overall sensitivity, specificity, and positive and negative predictive accuracy were 75%, 89.6%, 60% and 94.6%, respectively, for color Doppler US; 94%, 93%, 71%, and 99%, respectively, for CTA; and 90%, 94.1%, 75%, and 98%, respectively, for GD-enhanced MRA. CTA and GD-enhanced MRA have comparable and satisfactory results with respect to the negative predictive accuracy of the suspected renal artery stenosis. The concept of an imaging algorithm including US as screening test when appropriate and CTA or MRA as the second step-procedure is suggested. Therefore, DSA may be reserved for cases with major discrepancies or therapeutic interventions.     

Imaging Modalities for Renal Artery Stenosis in Suspected Renovascular Hypertension: Prospective Intraindividual Comparison of Color Doppler US,CT Angiography,GD-Enhanced MR Angiography,and Digital Substraction Angiography

The aim of the study was to evaluate the diagnostic accuracy of Color Doppler US, CT Angiography (CTA), and GD-enhanced MR Angiography (MRA) compared with digital subtraction angiography (DSA) for the detection of renal artery stenosis in patients with clinically suspected renovascular hypertension. Fifty-eight patients with suspected renovascular hypertension were enrolled in the study. All patients underwent Color Doppler US, CTA and GD-enhanced MRA. DSA was the gold standard method for the number of renal arteries, existence and degree of stenosis, or evidence of fibromuscular dysplasia. DSA depicted 132 renal arteries, 16 stenoses, and 4 arteries with fibromuscular dysplasia. Color Doppler US failed to detect 1 main and 14 polar arteries. CTA depicted all main renal arteries and 7/16 polar arteries, but failed to detect stenosis in two accessory vessels. Likewise, MRA did not detect stenotic accessory renal arteries, depicted 9/16 polar renal arteries, but missed two main renal arteries. All methods depicted the four main renal arteries with fibromuscular dysplasia. The overall sensitivity, specificity, and positive and negative predictive accuracy were 75%, 89.6%, 60% and 94.6%, respectively, for color Doppler US; 94%, 93%, 71%, and 99%, respectively, for CTA; and 90%, 94.1%, 75%, and 98%, respectively, for GD-enhanced MRA. CTA and GD-enhanced MRA have comparable and satisfactory results with respect to the negative predictive accuracy of the suspected renal artery stenosis. The concept of an imaging algorithm including US as screening test when appropriate and CTA or MRA as the second step-procedure is suggested. Therefore, DSA may be reserved for cases with major discrepancies or therapeutic interventions.     

Can magnetic resonance angiogram be a reliable alternative for donor evaluation for laparoscopic nephrectomy?

BACKGROUND: While hand-assisted laparoscopic donor nephrectomy (HLDN) is less invasive, which can encourage kidney donation, it requires more exact information about the renal vascular anatomy because of its limited visual field during nephrectomy. MRA is also an attractive choice because of its minimal invasiveness; further, it is an outpatient-based procedure, it uses non-nephrotoxic contrast material and it has no radiation. The aim of our study was to evaluate the effectiveness of gadolinium enhanced three-dimensional MRA (GdE-3D MRA) in a group of potential live donors who were candidates for HLDN. METHODS: From September 2002 to December 2004, 40 potential live renal donors were evaluated prospectively with GdE-3D MRA, and this imaging modality was performed before the gold standard, the intra-arterial digital subtraction angiogram (IA-DSA), was carried out. All the images were reviewed in a blinded manner by the attending vascular radiologist. The MRA findings were compared with the DSA findings and the surgical findings as the reference methods. We evaluated the accuracy of MRA for imaging the renal architectures, and especially for imaging the renal accessory arteries and the early branching arteries that are important determinants for selection of the donor kidney. RESULTS: Both the MRA and DSA images showed consistent findings with the surgical findings in 92.5% of the 40 donors. There were no discrepant cases in depicting the main renal artery. MRA showed 100% specificity for imaging both the renal accessory arteries and the early branching arteries, when compared with the surgical findings. The kappa values for the MRA and DSA for the accessory arteries were all 0.66 compared with the intraoperative findings. MRA also depicted one huge renal cyst in one donor and many small renal cysts in the other donors that could not be imaged by DSA. There were no adverse events during the MRA procedure. None of the findings missed by MRA resulted in deleterious consequences at laparoscopic nephrectomy for the donor and graft. CONCLUSIONS: Our limited experience with GdE-3D MRA for imaging the renal structures in kidney donor evaluation for HLDN has been quite satisfactory.     

Doppler Ultrasonography in Evaluation of Potential Live Kidney Donors: A Prospective Study

Purpose

We compared the accuracy of Doppler ultrasonography and intra-arterial digital subtraction angiography for preoperative visualization of the number of renal arteries in potential live kidney donors.

Materials and Methods

Intra-arterial digital subtraction angiography and Doppler ultrasonography were used to study the renal anatomy of 64 consecutive kidney donors. Doppler studies were performed without knowledge of the angiographic findings. All donors underwent nephrectomy, and the number of renal arteries at nephrectomy was compared with that predicted by intra-arterial digital subtraction angiography and Doppler ultrasonography.

Results

One renal artery was found in 53 harvested kidneys, 2 in 10 and 3 in only 1. Analysis of the data revealed sensitivity 96.2 percent and specificity 100 percent for intra-arterial digital subtraction angiography versus sensitivity 100 percent and specificity 60 percent for Doppler ultrasound. Overall accuracy was 96.8 percent for angiography versus 93.7 percent for Doppler ultrasound, compared to 96.2 and 100 percent, respectively, for single, and 100 percent and 60 percent, respectively, for double renal arteries (p less than 0.03). Both tests were interpreted as showing double vessels in the case with triple renal arteries.

Conclusions

Although Doppler ultrasonography is accurate in delineation of single renal arteries, its limited ability to identify multiple arteries should make one cautiously optimistic regarding its current use.     

Magnetic resonance angiography for preoperative evaluation of potential kidney donors

BACKGROUND: Careful evaluation of the renovascular anatomy for living kidney donors is essential to optimize donor and recipient outcomes. Arteriography has been the standard for delineating the renovascular anatomy. However, this procedure is invasive. Magnetic resonance angiography (MRA) is an attractive, noninvasive alternative. The aim of this study was to evaluate the accuracy of MRA in potential living kidney donors. METHODS: A retrospective comparison of the preoperative MRA results with the intraoperative anatomy was performed in 189 living kidney donors. RESULTS: MRA interpretations correctly identified the vascular anatomy of the donor kidneys in 173 donors (91.5%). In the remaining 16 patients (8.5%), the MRA interpretation was inaccurate. In 10 patients, the MRA reported fewer arteries than the number encountered during the donor operation, whereas in six patients MRA reported more arteries than what found during operation. In seven patients, MRA supplied additional important anatomical information, including kidney size disparity, the presence of nephrolithiasis, the presence of a renal cyst, and renal artery stenosis. All kidneys were successfully transplanted. The misinterpretation of the MRA did not adversely affect the recipient outcome. CONCLUSION: The noninvasive MRA evaluation of donor renovascular anatomy is an acceptable substitute for traditional angiography.     

Multidetector CT angiography in live donor renal transplantation: experience from 156 consecutive cases at a single centre

The performance of multidetector computed tomography (CT) angiography was assessed in the pre-operative evaluation of live renal donors. Between July 1998 and March 2006, 156 consecutive patients underwent open donor nephrectomy following pre-operative multidetector CT angiography (MDCTA). Operative notes were compared with radiological reports and discrepancies identified. MDCTA missed five of 28 accessory arteries (four visible with hindsight), accuracy of 96%. Of 30 early-branching renal arteries, eight were missed (all visible with hindsight), accuracy 95%. MDCTA missed only one of 13 venous anomalies (accuracy 97%) and also missed the only duplicated collecting system: both were undetectable with hindsight. Following modifications to image acquisition and interpretation sensitivity, negative-predictive value and accuracy were significantly increased. The results were compared with pooled data from published studies of live donor imaging. This study and previous studies of MDCTA had improved sensitivity for arterial and venous anomalies over single detector CT angiography and MR angiography. We conclude that multidetector CT angiography is an accurate modality in the pre-operative evaluation of live renal donors. Regular communication between the transplant surgeon and the radiologist is paramount to improve reporting of surgically relevant anatomy. Mechanisms should exist for auditing and improving pre-operative imaging in any live donor programme.     

Prospective study comparing three-dimensional computed tomography and magnetic resonance imaging for evaluating the renal vascular anatomy in potential living renal donors

OBJECTIVE: To prospectively compare the accuracy of multislice spiral computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) in evaluating the renal vascular anatomy in potential living renal donors. SUBJECTS AND METHODS: Thirty-one donors underwent multislice spiral CTA and gadolinium-enhanced MRA. In addition to axial images, multiplanar reconstruction and maximum intensity projections were used to display the renal vascular anatomy. Twenty-four donors had a left laparoscopic donor nephrectomy (LDN), whereas seven had right open donor nephrectomy (ODN); LDN was only considered if the renal vascular anatomy was favourable on the left. CTA and MRA images were analysed by two radiologists independently. The radiological and surgical findings were correlated after the surgery. RESULTS: CTA showed 33 arteries and 32 veins (100% sensitivity) whereas MRA showed 32 arteries and 31 veins (97% sensitivity). CTA detected all five accessory renal arteries whereas MRA only detected one. CTA also identified all three accessory renal veins whereas MRA identified two. CTA had a sensitivity of 97% and 47% for left lumbar and left gonadal veins, whereas MRA had a sensitivity of 74% and 46%, respectively. CONCLUSION: Multislice spiral CTA with three-dimensional reconstruction was more accurate than MRA for both renal arterial and venous anatomy.     

Morphologic and functional magnetic resonance imaging of renal artery stenosis: a multireader tricenter study.

The effect of combined morphologic and functional magnetic resonance (MR) imaging on the interobserver and intermodality variability for the grading of renal artery stenosis is assessed. In a randomized, blinded tricenter analysis, seven readers evaluated 43 renal arteries on x-ray digital subtraction angiography (DSA), 3D-Gadolinium MR angiography (3D-Gd-MRA), cine phase-contrast flow measurement (PC-flow), and a combined analysis of the last two. Interobserver variability was assessed for the grading of renal artery stenosis as well as regional vessel visibility. Intermodality variability for stenosis grading was analyzed in cases in which the readers agreed on the degree of stenosis in DSA. DSA had a substantial interobserver variability for the grading of stenosis (mean kappa kappa 0.64). 3D-Gd-MRA revealed a slightly improved interobserver variability but incorrectly graded 6 of 34 stenoses on a two-point scale (<50%, > or =50%). The combined approach of 3D-Gd-MRA and PC-flow revealed the best (P = 0.0003) interobserver variability (median kappa = 0.75) and almost perfect intermodality agreement with DSA (97% of cases). These findings were confirmed in a prospective analysis of 97 renal arteries. The vessel visibility of the renal artery ostium was significantly better in 3D-Gd-MRA than in DSA, whereas the visibility of the hilar and intrarenal vessels was significantly worse (P = 0.0001). A combined morphologic and functional MR examination significantly reduces interobserver variability and offers reliable and reproducible grading of renal artery stenosis based on stenosis morphology and hemodynamic changes. It can be considered a safe and noninvasive alternative for diagnostic DSA in cases that do not require assessment of intrarenal vessels.     

Multi-detector row CT scanner angiography in the evaluation of living kidney donors

Renal vascular anomalies are frequent and are not usually problematic, especially when they have been identified and localised with preoperative imaging; computed tomography angiography is a fast and minimally invasive procedure that may afford accurate visualisation of arterial and venous anatomy. We report on our experience with the utilisation of multi-detector row angiography in the preoperative evaluation of living kidney donors. Nineteen living kidney donors underwent multidetector row scan angiography with 3D post-processing. The subjects were 12 male and 7 female donors with a mean age of 60 years. Renal vascular anomalies were identified in 52.6% of donors. A total of 10 supernumerary arteries were identified. Surgical correlation was available for 19 kidneys (17 left and 2 right). The donated kidneys were selected on the basis of CT scan and renal function. CT scan identified all 29 arteries including 10 double right or left arteries (100% specificity and sensitivity). Dual multi-phase multi-detector row CT angiography is a minimally invasive and highly accurate method for preoperative evaluation of renal donors. It affords comprehensive depiction of the arterial and venous anatomy of the kidney, which is particularly critical for planning and performing the donor nephrectomy, especially via a laparoscopic approach.     

Preoperative evaluation of living kidney donors using multirow detector computed tomography: comparison with digital subtraction angiography and intraoperative findings

To assess the accuracy of multirow detector computed tomography (MDCT) for the evaluation of renal anatomy for preoperative donor assessment in living related kidney transplantation. MDCT-scans (4- and 16-slice-CT) of 51 consecutive living kidney donors (age, 51.6 +/- 9.7 years; range, 28-68 years) were analysed by three blinded observers and compared with digital subtraction angiography (DSA) and surgery. Contrast-enhanced MDCT was performed with 1 mm slice thickness reconstruction interval during arterial and venous phases. Supernumerary renal arteries, veins, early branching of vessels and abnormalities of the ureters were documented. The overall accuracy of computed tomography angiography (CTA) for detection and classification of surgically relevant arterial variants was 97% (99/102). The interpretation of 16-channel MDCT images was correct in all cases (accuracy, 100%), while the four-channel CTA had three incorrect results regarding the differentiation of early branching vessels from double renal arteries (accuracy, 93%). The overall accuracy of DSA was 91%. Renal vein abnormalities were correctly diagnosed with MDCT in 100% compared with 89% correct findings with DSA. There were three kidneys with incomplete ureter duplication, detected both with MDCT and DSA. MDCT demonstrated superior accuracy compared with non-selective DSA for the preoperative assessment of renal anatomy in living kidney donors; and for the distinction of supernumerary arteries versus early branching patterns, 16-channel CTA data were better than those of the four-channel system.     

Diagnostic accuracy of 64-MDCT angiography in the preoperative evaluation of renal vessels and compared with laparotomy findings in living donor kidney

Introduction: Multidetector-row computed tomography (MDCT) angiography is a reliable technique in preoperative renal anatomy evaluation in live renal donors. Objectives: To investigate the accuracy of early arterial phase findings and compares them with intraoperative findings. Methods: In this prospective study, 100 potential live donors undergoing preoperative MDCT and nephrectomy during 2010–2013 were included. The examination was performed with a 64-detector scanner including early arterial and venous phase. MDCT angiography started by bolus tracking and venous phase was acquired 9?s after arterial phase. Anatomical findings and vein and artery attenuation values were recorded and arterial phase findings were compared with intraoperative findings. Results: All anatomical findings reported by MDCT in early arterial phase were confirmed by intraoperative findings with sensitivity of 100%. Right renal vein was supernumerary in 17 cases and left renal vein was circumaortic in 3 and retroaortic in 5 cases. Renal arteries had early branching in 13, two arteries in 12 and accessory in 8 cases. Vein and artery attenuation values had significant difference between early arterial and venous phase (p?0.001). Conclusion: Early arterial phase has similar results to venous phase in preoperative evaluation and intraoperative findings and could be used alone to reduce radiation dose.     

USE OF SPIRAL COMPUTERIZED TOMOGRAPHY IN LIEU OF ANGIOGRAPHY FOR PREOPERATIVE ASSESSMENT OF LIVING RENAL DONORS

PURPOSE: We evaluate whether spiral computerized tomography (CT) can be used in lieu of renal angiography for preoperative assessment of living renal donors, with special attention to multiplicity of renal vasculature. MATERIALS AND METHODS: A total of 47 living renal donor candidates were evaluated with spiral CT and all but 2 underwent donor nephrectomy. Patients were divided into early and late groups because there was a learning curve with spiral CT. In the early group 18 donors underwent renal angiography as well as spiral CT and 10 underwent nephrectomy after spiral CT only. In the late group 5 had dual radiographic evaluation for ambiguities in spiral CT interpretation and 12 underwent nephrectomy after spiral CT only. Spiral CT was performed and interpreted blind to angiographic results, and vice versa. RESULTS: Spiral CT identified 50 of 52 renal arteries (96%) found at surgery overall and 23 of 25 (92%) found at surgery after spiral CT only. Two accessory arteries were missed in the 10 early group donors evaluated with spiral CT only, yielding an early negative predictive value of 80%. Renal angiography identified another accessory artery missed by spiral CT in the early group. All 3 missed vessels were identified retrospectively. No arteries found at surgery were missed in the late group (negative predictive value 100%), although there were 2 false-positive results detected by spiral CT relative to renal angiography in 1 candidate renal unit. Overall accuracy to predict early renal artery division relative to surgical findings was 93% for spiral CT and 91% for renal angiography. However, early renal artery division was clinically significant for only 1 of 11 vessels found at surgery. Spiral CT demonstrated 4 anomalous venous returns and renal angiography identified none. However, spiral CT missed 2 accessory veins and identified only 1 of 2 fibromuscular dysplasia cases. Total cost for spiral CT and renal angiography was $886 and $2,905, respectively. CONCLUSIONS: Spiral CT is a reasonably good alternative to renal angiography for living renal donor assessment but there is a profound learning curve for performance and interpretation. Renal angiography is still the gold standard with respect to the identification of arterial multiplicity and fibromuscular dysplasia, and it should be used adjunctively in cases with spiral CT ambiguity. Neither spiral CT nor renal angiography is ideal for the assessment of early renal artery division which is seldom an issue. The benefits of spiral CT over renal angiography are potentially lower morbidity, improved donor convenience and reduced cost.     

螺旋CT血管造影术前评估颈动脉狭窄程度的作用

探讨螺旋CT血管造影(SCTA)检查颈动脉狭窄的准确性,以及用SCTA代替减数血管造影(DSA)的可能性。方法:本组研究采用NASCET标准对照比较SCTA与DSA的颈动脉血管造影结果,并参考部分病例手术所见,以评估SCTA检查颈动脉狭窄的准确性。结果:本组29例颈动脉狭窄中,SCTA对照DSA的诊断总符合率为86.2％。其中严重狭窄组的相符率为100％。结论:SCTA不仅对颈动脉狭窄程度的诊断有很高的准确性和直观性,而且能够显示DSA难以发现的附壁钙化以及血栓,故有望取代DSA在颈动脉狭窄诊断中的地位。     

活体供肾术前评估中16层螺旋CT的价值

目的：评价16层螺旋CT三维重建在活体供肾血管、肾实质、泌尿系统评估中的实际应用价值.方法：回顾2004年以来41例活体肾移植供体临床资料,术前均行16层螺旋CT扫描,采集肾动脉期、静脉期以及排泄期的影像数据,采用MIP、VR、MPR和CRP等三维图像后处理技术,评估供体肾动脉、肾静脉、泌尿集合系统和肾实质情况,与术中所见相对照.结果：41例供肾动脉显示,34例双肾单支动脉供血,其中2例左肾动脉、3例右肾动脉分支较早;4例右肾见一支副肾动脉,3例左肾见一支副肾动脉;术中证实有1例右副肾动脉,1例左肾动脉早期分支未能在影像中显示清楚,准确率95.1%.41例供肾静脉显示,37例双肾静脉为单支,4例右侧双支肾静脉;术中证实5例右侧双支肾静脉未能在影像中显示,准确率87.8%;泌尿集合系统显影满意,1例左侧双肾盂双输尿管畸形.结论：16层螺旋CT三维重建能准确显示供体肾脏血管、泌尿集合系统、肾实质解剖及可能的病理情况,给临床肾移植术前评估提供有价值的帮助,可作为供体术前检查的首选方法.     

Comparison of digital subtraction angiography, CT angiography, and ultrasonic Doppler examination in the evaluation of penile arterial lesions]

BACKGROUND: CT angiography reconstructed by a multidetector-row helical CT scanner is a newly developed form of imaging. We compared CT angiography and ultrasonic Doppler examination with digital subtraction angiography (DSA) in the diagnosis of arterial lesion. METHOD: Eighteen patients with arteriogenic erectile dysfunction (ED) underwent color Doppler study, DSA, and CT angiography after providing informed consent. The CT angiography images were obtained by a multidetector-row helical CT scanner, Asteion TSX021A (TOSHIBA). We injected prostaglandin E1 into the penile cavernous body, and then rapidly infused nonionic contrast medium into the antecubital vein. DSA and CT angiography images of the bilateral internal pudendal arteries and cavernous arteries were examined for stenotic lesions or occlusion. We also compared the peak systolic blood flow velocity in the cavernous artery measured by color Doppler ultrasound with CT angiography and DSA. RESULTS: The CT angiography and color Doppler studies were performed on an outpatient basis, but DSA required hospitalization. In the 36 internal pudendal arteries, DSA represented 22 normal arteries and 14 stenosis or occlusions. CT angiography showed 15 normal arteries and 21 occlusions. For the diagnosis of stenosis or occlusion in the internal pudendal artery, the CT angiography image had a good agreement, with a sensitivity of 1.00, specificity of 0.68, and accuracy of 0.81. For diagnosis in the cavernous artery, CT angiography image also showed a good agreement with DSA; however, the quality of the images of fine arteries was better in the DSA images. The inferior view and internal view of the pelvis in CT angiography were helpful for visualizing the internal pudendal artery, especially at the pubic bone. There was insufficient correlation between peak systolic blood flow velocity and DSA findings. There were no serious complications involved in either examination. CONCLUSIONS: CT angiography has not yet reached the same level as DSA in the evaluation of fine arteries. However, CT angiography can produced images sufficient for the diagnosis of arteriogenic ED with some advantages. We believe that with improvement, CT angiography will become an adequate replacement for DSA in the diagnosis of penile arterisl lesion.     

Assessment of live kidney donors by magnetic resonance angiography: reliability and impact on outcomes

Abstract: Background:  Kidney allograft retrieval from live donors requires accurate determination of kidney anatomy prior to surgery, particularly the arterial supply. Traditionally, conventional angiography has been used to obtain this information. Magnetic resonance angiography (MRA) offers a non-invasive, cost-effective alternative, but has been considered to be less accurate. Despite this criticism, many centers have moved to MRA screening of potential kidney donors. The objective of this study is to evaluate our experience of the reliability of MRA in determining the arterial anatomy of living kidney donors as compared to the intra-operative findings.
Methods:  We performed a retrospective review of gadolinium-enhanced, ultra-fast, three-dimensional, spoiled gradient-echo MRA in live kidney donors in the Southern Alberta Transplant Program and compared these results with the intra-operative findings during nephrectomy, as the gold standard.
Results:  Of the 66 patients, an accessory renal artery was found intra-operatively in eight cases; two of which were erroneously diagnosed as normal by MRA. The negative predictive value for MRA was 0.97, false-negative rate was 0.25, and sensitivity was 0.75. No patient experienced side-effects from the MRA procedure. No donor needed conversion to open nephrectomy because of an undetected accessory renal artery. One allograft with an accessory renal artery developed thrombosis of the lower pole of the kidney despite arterial reconstruction. Kidney function in the recipient of this allograft was excellent and there was no urinary leak.
Conclusion:  In our hands, MRA determined the vascular anatomy of potential kidney donors with an acceptable negative predictive value of 97%.