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.     

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.     

Utility of 16-multidetector CT angiography in the preoperative evaluation of vascular and ureteral anatomy of donor nephrectomy

ObjectiveTo evaluate the accuracy of 16-section multi-detector row computed tomography (MDCT) angiography in the preoperative evaluation of renal transplant donors in comparison with intra-operative findings.Patients and methodsIn this prospective study 89 consecutive renal donors (69 men and 20 women) underwent 16-MDCT angiography followed by open surgical donor nephrectomy from January 2008 to March 2010. We reported the number and origin of renal arteries and the presence of early branching arteries. Renal venous anatomy was evaluated for the presence of major and minor venous anomalies. The renal calyces and ureters were assessed with delayed excretory phase images. On a 3D workstation, images were evaluated by the radiologist and the urologist. These CT angiography results were compared with surgical findings.ResultsThe mean age of the donors was 31 years. Open donor nephrectomy was performed on the left in 52 and on the right in 37 subjects. At surgery, accessory renal arteries were found in 14 kidneys (double arteries to 13 kidneys and triple arteries to one kidney). CT and surgical findings agreed in 92% of subjects. Seven small accessory renal arteries in seven donors were missed by radiology reviewers. Early branching of the renal arteries was shown in 5 arteries, and CT matched surgical findings in 88 cases (99%). Renal vein anomalies were present in six subjects, three of them were missed with the preoperative CT. The major shortcoming of MDCT angiography was noted in identifying minor venous anatomy. The presence of discrepancies between pre-operative MDCT and the findings at surgery did not affect the clinical outcome of transplantation, except in one case where intra-operative surgical distress was noted due to failure in identifying multiple major renal veins.Conclusions16-MDCT angiography is a good modality in the pre-operative evaluation of live renal donors. However, it provides suboptimal information on renal vascular anatomy, particularly complex venous patterns. Surgeons should not rely fully on pre-operative CT angiography while performing donor nephrectomy.     

The use of spiral computed tomographic angiography for the assessment of living kidney donors

BACKGROUND: Recent reports suggest that spiral computed tomographic (CT) angiography can replace conventional angiography and intravenous urography for the assessment of potential kidney donors. The purpose of this study is to assess the accuracy of spiral CT in potential kidney donor workup. METHODS: Over a period of 1 year, from December 1995 to December 1996, 16 consecutive potential renal donors had intravenous pyelography, percutaneous transfemoral angiography with selective renal angiography and spiral CT angiography. The spiral CT and renal angiograms were assessed independently by two radiologists. The number of renal arteries, presence or absence of renal artery stenoses and associated parenchymal abnormalities were assessed. RESULTS: A total of 39 renal arteries were detected. Conventional transverse scans viewed in a cine loop format detected all 39 vessels, while the maximum intensity projection and shaded surface display demonstrated only 37. All 39 vessels were detected by the catheter angiography. With the exception of one potential donor with fibromuscular dysplasia, 15 donors were accepted. There was 100% accuracy between the two methods of visualization for the renal arteries. A simple renal cyst was noted in both spiral CT and conventional angiogram, while another had gallstones in spiral CT. CONCLUSIONS: Spiral CT angiography performed as an outpatient procedure is less invasive, less expensive, and provides good images of the arterial and venous anatomy. It has the potential to replace conventional catheter angiography and intravenous pyelogram in the assessment of potential renal donors.     

Magnetic resonance renal angiography and venography: an analysis of 111 consecutive scans before donor nephrectomy

OBJECTIVE: To determine the accuracy of magnetic resonance imaging (MRI) renal angiography in predicting vascular anatomy before donor nephrectomy, to determine the significance of missed vessels and to ascertain whether vessels are missed because of technical limitations or errors in interpretation. PATIENTS AND METHODS: In all, 111 consecutive living donations were assessed; the anatomy on MRI before donation was compared with that at nephrectomy. The significance of additional arteries and veins was recorded at the time of donation, with extra vessels either anastomosed or sacrificed. Finally, the scans in which extra vessels had not been identified were re-examined to establish whether these could be identified retrospectively. RESULTS: In all, 93 kidneys had a single renal artery and 18 had two. All lower pole arteries were anastomosed and all upper pole arteries were sacrificed. Nine arteries were identified before surgery (five were to the lower pole), and nine were missed (four to the lower pole). There were 13 kidneys with more than one vein. Four of these were seen on MRI. However, an extra vein was anastomosed in only one case. On review of the imaging, three arteries were missed because of human error and six due to technical limitations. Of the nine missed veins, only three were easily identified retrospectively. Overall, using MRI as a preoperative investigation for the 111 consecutive cases, the surgeon encountered a previously unidentified accessory artery in nine (8%), and this required anastomosis in four (4%). CONCLUSION: MR angiography has the advantage over computed tomography (CT) of having virtually no side-effects, and if the small possibility is accepted of missing extra vessels because of technical limitation or interpretation, it is a good investigation. However, in light of the failure to visualize all arteries transplanted, we have started to use multi-slice (16-channel) CT to see if its improved spatial resolution alters the results.     

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.     

螺旋CT肾动脉成像在腹腔镜肾部分切除术中的应用

目的：探讨术前肾血管CT血管成像（CTA）在指导腹腔镜下肾部分切除术中血管处理的作用。方法：15例患者中肾癌9例,肾错构瘤6例。术前均行。肾血管CTA。经腹膜后入路施行腹腔镜肾部分切除术,术中根据CTA提示寻找并阻断肾动脉。结果：CTA示肾门前肾动脉分支3例,占总病例数20％。副肾动脉1例,占总病例数6．7％。术中探查均发现CTA所提示的异常血管,探查未发现其他异常动脉。本组15例全部手术成功。结论：CTA能清楚显示血管的解剖及变异,为术中处理肾动脉提供有效的指导。     

Intravenous digital subtraction angiography and helical computed tomography in evaluation of living renal donors

OBJECTIVES: The present study was carried out to evaluate the accuracy of helical computed tomography (CT) and intravenous digital subtraction angiography (IV-DSA) on anatomical assessment of renal vasculature for living renal donors. METHODS: Forty-two healthy potential renal donors were prospectively evaluated and 35 subsequently underwent donor nephrectomy after helical CT and IV-DSA evaluation. The vascular and non-vascular findings were compared between the findings on helical CT, IV-DSA and surgery. RESULTS: Ten prehilar branches and five accessory renal arteries were found at nephrectomy. Overall, operative findings agreed with the findings by IV-DSA in 89% and by helical CT in 83%. In delineating accessory arteries, IV-DSA had a sensitivity of 60% and specificity of 97%, whereas helical CT had a sensitivity of 40% and specificity of 100%. In delineating prehilar branches, IV-DSA had a sensitivity of 90% and specificity of 100%, whereas helical CT had a sensitivity of 70% and specificity of 100%. Accessory arteries and prehilar branches that were not detected by helical CT or IV-DSA, were less than 2 mm in diameter and did not require vascular reconstruction. Renal veins were delineated in 63% by IV-DSA, whereas they were clearly imaged by helical CT in all cases, including a case with a circumaortic renal vein. Non-vascular findings were obtained in 64% by helical CT, including two renal tumors. None of these findings were obtained by IV-DSA. CONCLUSION: Helical CT and IV-DSA provide comparably sufficient information on renal artery vasculature. However, helical CT provides significantly more information on venous and non-vascular findings as a single-imaging modality.     

多层螺旋CT血管成像在后腹腔镜肾脏切除手术中的应用价值

目的：探讨术前多层螺旋CT血管成像技术在后腹腔镜下。肾脏切除手术中的指导意义。方法：45例患者术前行64排螺旋CT血管成像检查,明确肾血管与病肾及病灶的三维解剖关系,并在其指导下,行根治性肾切除术14例,’肾部分切除术7例,其中肾段动脉阻断的肾部分切术2例;肾输尿管膀胱袖状切除7例,单纯性肾切除16例,上肾单位切除1例。结果：多层螺旋CT血管成像提示动脉解剖异常占26．7％,动脉病变占6．7％。静脉解剖异常占22．4％,所提示的血管解剖异常及病变与术中所见吻合率100％,但术中发现异常的肾肿瘤静脉血管,在螺旋CT血管成像中未能清晰显示占6．7％。在多层螺旋CT血管成像的提示下,术中病肾血管的处理快速准确,手术顺利。术中平均出血80ml,手术平均时间170min,无中转开放手术。结论：术前行多层螺旋CT血管成像检查,可直观准确地评估血管。特别是动脉血管与病肾及病灶的三维解剖关系,了解可能存在的动静脉解剖变异或血管病变,拟定手术方案,指导术者快速准确地处理血管,避免盲目操作,减少出血和并发症。在后腹腔镜的肾脏切除手术中．有较重要的价值。     

Evaluation of live renal donors with three-dimensional contrast-enhanced magnetic resonance angiography in comparison to catheter angiography

BACKGROUND: Catheter angiography is traditionally used to determine renal arterial anatomy in live renal donors. Three-dimensional (3D) contrast-enhanced magnetic resonance imaging (MRA) has been suggested as a noninvasive replacement. We assessed the possibility of using MRA in live renal donors in Malaysia. METHODS: Twenty-six consecutive live renal donors were recruited from 2000 to 2002. All potential donors underwent evaluation of the renal arteries using both techniques. Angiographic findings from both modalities were subsequently compared with surgical findings at the time of donor nephrectomy. The total number and diameter of the arteries and the presence of early branching and renal abnormalities were noted. RESULTS: Both angiographic modalities were able to detect multiple renal arteries with catheter angiography having a sensitivity of 100% and MRA a sensitivity of 97%. MRA missed one 1-mm artery due to a low index of suspicion. Renal artery caliber measurements were not significantly different between the two methods. However, both techniques tended to overestimate the caliber of the renal arteries when compared with measurements taken at surgery. Early branching was found in two arteries at the time of surgery, but only one was detected by both techniques. Renal cysts seen on MR were not detected by catheter angiography. CONCLUSIONS: Our findings suggest that noninvasive MRA is a promising substitute for catheter angiography to evaluate the renal arteries of live donors.     

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.     

Comparison of spiral CT scan and arteriography for evaluation of renal and visceral arteries

Renal and visceral artery images obtained concurrently with spiral CT and conventional arteriography were compared for 32 patients. Indications for imaging were occlusive disease (n=12), aneurysmal disease (n=9), and renal or visceral artery disease (n=11). Conventional arteriography enabled visualization of 64 renal arteries and 15 accessory renal arteries. Lateral aortograms obtained in 15 patients enabled visualization of 14 superior mesenteric (SMA) and 14 celiac arteries. Spiral CT enabled visualization of 60 renal arteries, 12 accessory renal arteries, 27 SMAs, and 22 celiac arteries. Calcification or a disparity in timing of contrast material injection and scanning prevented visualization of the celiac artery in 10 patients and the SMA in four patients. With conventional arteriography as the standard for comparison, spiral CT had a sensitivity of 67% and a specificity of 95% for depiction of at least 75% stenosis in the main renal artery. By means of the Pearson correlation coefficient, significant correlation (p < 0.001) was confirmed between spiral CT and arteriography for evaluation of stenosis of the main renal artery, SMA, and celiac artery. This early experience suggests that spiral CT may be useful in evaluation of renal and visceral arteries and their relationship to aortic disease.Presented at the Twentieth Annual Meeting of the Peripheral Vascular Surgery Society, New Orleans, La., June 10, 1995.     

Prospective comparison of 3-dimensional volume rendered computerized tomography and conventional renal arteriography for surgical planning in patients undergoing laparoscopic donor nephrectomy

PURPOSE: We prospectively assessed the accuracy of 3-dimensional (3-D) volume rendered computerized tomography (CT) and conventional renal arteriography to visualize renovascular anatomy in patients undergoing laparoscopic donor nephrectomy. MATERIALS AND METHODS: A total of 60 consecutive patients undergoing laparoscopic donor nephrectomy (left side in 46 and right side in 14) prospectively underwent 3-D CT and renal angiography. A short videotape of 3-D CT was prepared using volume rendering software that demonstrated the anatomical location, number, anomalies and spatial interrelationships of the renal arteries and veins. These 3-D videotapes and arteriogram findings were directly correlated with intraoperative surgical findings at laparoscopy and during ex vivo bench preparation of the harvested kidney. The perceived intraoperative value of 3D-CT to delineate renovascular anatomical detail was scored subjectively by the laparoscopic surgeon for each case on a 10-point scale of 0--completely inaccurate to 10--completely accurate. RESULTS: There were no complications related to the 3-D CT protocol and volume rendering was successful in all patients. Three-D CT accurately identified the number of renal arteries in 59 patients (98%). In 1 patient with 3 renal arteries 3-D CT and arteriogram each identified only 2. In the 46 patients undergoing left donor nephrectomy 3-D CT accurately identified the number of veins and venous anomalies in 45 (98%), including 2 with a circumaortic left renal vein. Another case of circumaortic vein was misdiagnosed as 2 renal veins. On the right side in 14 patients 3-D CT accurately identified the renal veins in 13 (94%) and missed 1 vein in a patient with 2 renal veins. Angiography correctly identified the number of renal veins in only 52 cases (87%). Furthermore, it misdiagnosed all 3 cases of circumaortic left renal vein. The laparoscopic surgeon believed that 3-D CT accurately identified the location and anatomical interrelationship of the renal vessels with precision. Mean subjective score +/- SEM was 8.5 +/- 1 for the arterial system, 8.6 +/- 1.1 for the venous system and 9.2 +/- 0.5 for any vascular anomalies. CONCLUSIONS: Three-D CT accurately identifies renal vascular anatomy in a manner that may facilitate renal hilar dissection during laparoscopic donor nephrectomy, especially during the initial surgeon experience. This imaging modality integrates essential information from angiography, venography and excretory urography into a single study, and it can obviate the need for more invasive vascular imaging in most cases.     

Pre-operative evaluation of living kidney donors using computerized tomographic angiography (CTA) and conventional angiography: comparison with intraoperative findings

This study was undertaken to assess the accuracy of computerized tomographic angiography (CTA) for the evaluation of renal vascular anatomy for pre-operative donor assessment in living kidney transplantation and to compare it with conventional angiography. CTA of 70 living donor kidney donors were analyzed by two blinded observers and compared with the intraoperative findings. Similarly, findings of formal angiography of 30 living donor kidney donors were compared with the intraoperative observations. In the CTA group, there were two patients each with two main renal veins discovered during surgery that had not been recorded on CTA. In the second group, there was one patient with unrevealed two main renal veins before surgery. In both groups, accessory renal arteries were diagnosed. Overall, the accuracy for renal main artery anatomy was 100% for both CTA and conventional angiography. Accuracy for renal main vein anatomy was 97.1% and 96.6% for CTA and conventional angiography, respectively. Hence, these two modalities had comparable results for assessment of main renal vasculature anatomy.     

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.     

Contrast enhanced spiral computerized tomography in live kidney donors: a single session for anatomical and functional assessment

PURPOSE: We evaluated contrast enhanced spiral computerized tomography (CT) as a single session for anatomical and functional assessment of potential live kidney donors. MATERIALS AND METHODS: The study included 80 consecutive kidney donors. In addition to routine donor evaluation, radiological imaging of the kidneys was performed with spiral CT, which was also used for selective determination of the glomerular filtration rate (GFR) of each kidney. All donors underwent 99mTc-mercaptoacetyltriglycine renal scan as a gold standard for GFR determination. Anatomical results of spiral CT were compared to operative findings at donor nephrectomy. Moreover, the results of CT GFR were compared with those of standard 99mTc-mercaptoacetyltriglycine GFR. RESULTS: Spiral CT detected major renal abnormalities that might be potentially significant for safe renal donation in 4 of the 80 donors (5%). Spiral CT had 100% sensitivity, 85.7% specificity and 97.2% overall accuracy for detecting the number of renal arteries. To identify the number of renal veins spiral CT had 100% sensitivity, 92.3% specificity and 98.6% overall accuracy. A comparison between the isotope GFR of each kidney with the corresponding CT GFR showed a perfect correlation (r = 0.54, p <0.001). For the right and left kidneys mean isotope clearance was not significantly different from that of mean CT clearance. CONCLUSIONS: Multidetector row spiral CT with contrast medium can provide accurate information regarding the anatomy of the urinary tract and vasculature of the kidney. Moreover, it can detect renal and vascular abnormalities that might be potentially significant for safe renal donation. In addition, it can accurately demonstrate selective GFR of each kidney. Therefore, we recommend spiral CT with contrast material as a single radiological diagnostic modality for the assessment of potential live kidney donors.     

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.     

Accuracy of three-dimensional CT angiography for preoperative vascular evaluation of laparoscopic living renal donors

PURPOSE: A retrospective review of preoperative three-dimensional (3D) CT and the operative findings during laparoscopic donor nephrectomy. PATIENTS AND METHODS: Fifty-four consecutive patients underwent laparoscopic donor nephrectomy. Of these patients, 51 had preoperative 3D reconstructed CT scans. Each radiologic report was compared with the operative report. RESULTS: The 3D CT correctly identified the arteries in 98% of the patients and the veins in 96%. CONCLUSIONS: Preoperative CT angiography can accurately identify the renal vasculature.     

Preoperative evaluation of living renal donors with gadolinium-enhanced magnetic resonance angiography

BACKGROUND: Preoperative evaluation of living renal donors includes an intra-arterial digital subtraction angiography (DSA). Inasmuch as this technique is invasive, uses radiation and an iodine-containing contrast medium, an alternative technique would be preferable. The purpose of this study was to determine the accuracy of gadolinium-enhanced magnetic resonance (MR) angiography in the visualization of renovascular anatomy for the preoperative evaluation of renal donors. METHODS: Twenty-four consecutive potential renal donors underwent gadolinium-enhanced MR angiography before the standard of reference, intra-arterial DSA. Both modalities were evaluated in a blinded manner. The results were correlated with the surgical findings. RESULTS: Three MR angiograms were technically unacceptable because of inadequate breath-hold. The remaining 21 donors had 47 renal arteries, including 5 accessory renal arteries, which were all visualized by MR angiography. MR angiography failed to visualize one case of subtle fibromuscular dysplasia in the distal part of a renal artery. In one donor, a small accessory renal artery, which had not been visualized on DSA, was encountered during nephrectomy. CONCLUSION: Gadolinium-enhanced MR angiography is an accurate minimally invasive method for the detection of accessory renal arteries in the preoperative evaluation of potential renal donors. The accuracy for excluding stenosis in general is high; however, the depiction of stenosis that are located far distally, or in the branch vessels, is less accurate. Advantages of gadolinium-enhanced MR angiography over the currently used method, intra-arterial DSA, are the minimal invasive nature, lower costs, and superiority in detecting venous anomalies, renal cysts, and tumors.