MR angiography with three-dimensional MR digital subtraction angiography

We have developed a time-resolved, contrast-enhanced, volume-imaging technique for magnetic resonance (MR) angiography, known as three-dimensional (3D) MR digital subtraction angiography (DSA). This technique greatly improves MR angiogram quality because it combines the injection of a contrast agent with the ability to image the temporal passage of this agent and, thereby, obviates the need for timing scans or other complicated synchronization schemes. Three-dimensional MR DSA also represents a potential improvement in the sense that, relative to DSA and computed tomography (CT) angiography, the contrast agent is less toxic. Additionally, unlike CT angiography, images may be acquired during the passage of the contrast agent. Therefore, 3D MR DSA shows the sequential passage of contrast through the arterial and venous system, followed by uptake in various organs. Unlike conventional DSA, 3D MR DSA imaging acquires full volume datasets, which allows subsequent reprojection and reformatting. Because images are obtained at approximately 2-6 s time intervals using a temporal aperture on the order of several seconds, motion (such as respiration) causes only a temporary disruption of image quality, similar to that observed in MR fluoroscopy. These temporal characteristics also make the proposed sequence insensitive to variations in the shape and timing of the contrast-pass curve. Although the individual time-resolved images will have somewhat decreased signal-to-noise ratio (SNR) relative to nontime-resolved scans collected in the same acquisition time, the SNR improvement due to the gadolinium appears to accommodate this trade-off. Additionally, if motion between successive images is small, then the full suite of temporal processing schemes, previously investigated in connection with DSA and time-resolved two-dimensional (2D) MR, such as mask mode subtraction, simple matched filtering and Eigen filtering, can be used to obtain composite images. These derived images generally have an increased SNR or negligible venous signal if an arterial-phase image is not obtained in the early time-resolved images. In summary, 3D MR DSA will significantly advance MR angiography because of the following intrinsic advantages: (1) improved signal-to-noise, (2) scan orientation may be chosen independently of the direction of blood flow, (3) uniform vascular signal, even from regions of complex flow, (4) minimization of motion artifacts, (5) greatly reduced sensitivity to variation in the shape and timing of the contrast bolus, (6) ability to be reformatted or reprojected, and (7) ability to apply a variety of temporal postprocessing techniques.     

Digital subtraction indocyanine green angiography of occult choroidal neovascularization

OBJECTIVE: This study aimed to use a new technique for ocular imaging, digital subtraction indocyanine green angiography (DS-ICGA), to evaluate patients with occult choroidal neovascularization (CNV). DESIGN: The design was a cross-sectional study of patients with occult CNV. PARTICIPANTS: A total of 31 eyes of 31 patients were studied. INTERVENTION: Digital subtraction of sequentially acquired indocyanine green angiographic frames was used to image the progression of the dye front in eyes with occult CNV. A method of pseudocolor imaging of the choroid was developed that allows differentiation and identification of underlying choroidal arteries and veins. RESULTS: The DS-ICGA of occult CNV showed consistent findings. Occult CNV was imaged with greater detail and in a shorter period of time than with conventional indocyanine green angiography. The fundus landmarks were retained with DS-ICGA much better than with conventional indocyanine green angiography. CONCLUSIONS: The DS-ICGA uses time to dissect the choroidal circulation. With DS-ICGA, occult CNV could be imaged more quickly and in greater detail than with conventional imaging techniques. The DS-ICGA may improve the authors ability to image, and subsequently treat, occult CNV.     

Comparison of two-dimensional MR digital subtraction angiography of the lower extremity with x-ray angiography

PURPOSE: To perform a preliminary evaluation of the diagnostic accuracy of contrast-enhanced, two-dimensional (2D) magnetic resonance (MR) digital subtraction angiography (DSA) of the lower extremity by comparison with x-ray angiography (XRA). MATERIALS AND METHODS: Forty lower extremities in 22 patients were imaged at multiple levels with both XRA and 2D MR DSA. Images were retrospectively analyzed by three radiologists in a randomized blinded manner. Seventeen vascular segments were graded as an insignificant lesion, a significant lesion, or as an occlusion. With the use of segments well depicted with XRA as the gold standard, the sensitivity, specificity, and accuracy of 2D MR DSA, as compared with XRA, were evaluated. The McNemar-Stuart-Maxwell test was performed to determine the significance of any differences found. RESULTS: Three hundred eighty-three arterial segments were evaluated with both techniques. Three hundred one segments were well depicted with XRA. There was no significant difference between 2D MR DSA and XRA for assessing the degree of occlusive disease in these 301 segments (.25 < P < .5). The sensitivity, specificity, and diagnostic accuracy of 2D MR DSA were found to be 90%, 98%, and 93%, respectively. CONCLUSION: Two-dimensional MR DSA is an accurate method for assessing arterial lesions in the lower extremity.     

The role of magnetic resonance angiography in the assessment of intracranial vascular disease

Magnetic resonance techniques have a significant role in the evaluation of intracranial vascular diseases; however, to achieve an appropriate diagnosis, a combination of both magnetic resonance imaging and angiography are needed. It is extremely important for the interpreting physician to be aware of the potential limitations of the techniques being used. With this knowledge, magnetic resonance techniques can eliminate the need for more invasive procedures. An overview of the current methods and their applications and limitations is provided.     

CT angiography versus intraarterial digital subtraction angiography for assessment of aortoiliac occlusive disease

OBJECTIVE: The purpose of this study was to evaluate the accuracy of CT angiography (CTA) with a single helical acquisition for assessment of stenoses and occlusions of the iliac arteries. SUBJECTS AND METHODS: In our prospective study, intraarterial digital subtraction angiography and IV CTA were performed from the suprarenal aorta to below the femoral bifurcation in 30 patients with vascular occlusive disease. Maximum-intensity-projection images in multiple views were also obtained. The accuracy of CTA with and without analysis of axial images was determined. RESULTS: Sensitivity and specificity of CTA were 100% for iliac artery occlusions with a confidence interval 85-100% and 97-100%, respectively. When axial scans were interpreted, 14 of 15 high-grade (> 75%) stenoses were recognized. Sensitivity and specificity of CTA were 93% (range, 68-100%) and 99% (range, 97-100%), respectively. When maximum intensity projections alone were analyzed, sensitivity for the diagnosis of 15 high-grade stenoses was only 53% (range, 27-79%) because calcified plaques obscured six stenoses. CONCLUSIONS: CTA accurately reveals iliac artery occlusions. Observers of CT angiograms may overlook short stenoses in rare instances. Calcified plaques limit the use of maximum-intensity-projection images.     

Renovascular arterial hypertension. Importance of subtraction digital angiography in its diagnosis

The objective of this study is to contribute to the positioning of the intravenous digital subtraction angiography (IVDSA) in the detection of morphologic abnormalities of renal arteries (RAs), susceptible to originate renovascular hypertension (RVH). The authors focus on the prevalence of RVH in the broad spectrum of systemic arterial hypertension. The definition of RVH is given and its diagnostic criteria are revisited. The angiography methods used in the evaluation of RAs morphologic abnormalities are described.     

Diagnostic value of spiral-CT angiography in comparison with digital subtraction angiography before and after peripheral vascular intervention

To evaluate spiral-computed tomography (CT) angiography in primary diagnosis and/or in noninvasive follow-up after vascular intervention, we compared spiral-CT angiography and conventional angiography before and after vascular intervention. Helical-CT examinations before and after percutaneous transluminal angioplasty (PTA) or stent implantation were performed in 10 patients (mean age 63 years) with symptomatic peripheral arteriosclerotic disease. Stenoses were located in the iliac, femoral, or popliteal artery. CT examinations were done with a spiral-CT in double detector technique (CT Twin, Elscint). The parameters were as follows: slice thickness: 5.5 mm, increment: 2.7 mm, pitch: 1.5, contrast medium: 150 mL, flow rate: 2.5 mL/second, delay: 30 seconds. For evaluation, transverse planes as well as maximum intensity projections and 3-D reconstructions were used. The possible scan length reached from the aortic bifurcation down to about 10 cm below the ankle trifurcation. Preinterventional digital subtraction angiography (DSA) was superior to CT angiography (CTA: 94%, maximum intensity projection [MIP] alone: 65%), although high-grade stenoses were detected by both methods. After intervention, a resolved stenosis and improved peripheral flow could be detected by helical-CT as well as by intraarterial angiography in every patient (100%). In the primary diagnosis of vascular changes, intraarterial DSA remains the method of choice. Nevertheless, spiral-CT angiography shows comparable results after percutaneous intervention and becomes a noninvasive alternative in the postinterventional follow-up.     

Spiral CT angiography

Spiral CT angiography is a new, minimally invasive technique for vascular imaging that is made possible by combining two recently developed techniques: slip-ring CT scanning and computerized three-dimensional (3D) reconstruction. The purpose of this essay is to illustrate the appearances of various normal and diseased vessels using this technique.     

Value of image subtraction in 3D gadolinium-enhanced MR angiography of the renal arteries

The objective of this study was to evaluate quantitatively and qualitatively the effect of image subtraction on the image quality of three-dimensional (3D) gadolinium-enhanced MR angiograms of the renal arteries. Breath-hold 3D gadolinium MR angiography (MRA) as well as conventional contrast angiography of the renal arteries was performed on 20 patients with suspected renovascular hypertension. MR angiograms were acquired before and during dynamic infusion of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). Contrast-enhanced images were compared with images that had undergone voxel-by-voxel signal intensity subtraction of contrast-enhanced data from precontrast data. One false positive finding for significant renal artery stenosis was recorded with MRA using conventional angiography as the gold standard. Image subtraction did not alter the diagnosis at MRA in any case. The mean contrast-to-noise ratio (CNR) was significantly higher (P < .05) on the subtraction MR angiograms compared to the nonsubtracted MR angiograms. There was no significant difference in the signal-to-noise ratio (SNR). Qualitative analysis revealed a significant improvement in image quality after image subtraction with respect to visualization of the distal renal arteries. In conclusion, image subtraction improves the quality of renal MRA in terms of both CNR and visualization of the distal renal arteries.     

Three-dimensional respiratory-gated MR angiography of coronary arteries: comparison with conventional coronary angiography

OBJECTIVE: MR coronary angiography is most often performed using two-dimensional techniques. Although three-dimensional (3D) acquisitions do have important advantages, they take too long for a single breath-hold and are thus susceptible to respiratory motion artifacts. The purpose of this study was to investigate the accuracy of a unique respiratory-gated 3D MR angiographic technique in identifying the proximal coronary arteries in patients suspected of having coronary artery disease. In addition, we investigated the capability of this technique to detect proximal stenoses. SUBJECTS AND METHODS: We performed a prospective blinded study in 20 patients who were referred for conventional coronary angiography. A cardiac-gated 3D gradient-echo sequence with fat suppression was used. Retrospective respiratory gating was performed using navigator echoes of the diaphragm position. Using multiplanar reformatting, two independent readers blindly analyzed the data sets for visualization of major coronary arteries, lengths of imaged segments, and detection of significant stenoses (> 50% occlusion of the luminal diameter by conventional angiography). RESULTS: Seventy-seven of 80 (96%) coronary arteries were positively identified. In one patient, an anomalous coronary anatomy was readily identified and confirmed by conventional angiography. The average lengths of the imaged segments of the right, left main, left anterior descending, and left circumflex coronary arteries were 58 +/- 13 mm, 9 +/- 5 mm, 59 +/- 16 mm, and 24 +/- 10 mm, respectively. Overall sensitivity for the detection of stenoses was low (38%), with a specificity of 95%. Interobserver agreement was 0.92, with a kappa value of 0.65. CONCLUSION: Respiratory-gated 3D MR angiography allows accurate identification of proximal coronary arteries and may be valuable for 3D imaging of coronary anomalies. Further technical improvements are required to enhance the value of the technique in detecting stenoses.     

Digital subtraction rotational angiography for aneurysms of the intracranial anterior circulation: injection method and optimization

PURPOSE: To optimize parameters of rotational angiography for examination of the internal carotid circulation; to compare rotational angiography with standard digital subtraction angiography (DSA) in the evaluation of aneurysms of the intracranial internal carotid circulation; and to determine tolerance and safety limits of prolonged internal carotid injection angiography. METHODS: Rotational angiograms were obtained during injection of the internal carotid circulation as part of the clinical angiographic evaluation of aneurysms in 41 patients. Injection rates, X-ray delays, and fields of view were studied retrospectively. Findings at rotational angiography and standard DSA were compared. Nonionic contrast material was injected over 6 seconds, and patients were studied before and after prolonged injection angiography by physical and laboratory examination, including measurement of blood pressure, pulse, and intracranial pressure. RESULTS: Vascular conspicuity was equivalent at carotid injection rates of 4 and 5 mL/s delivered over 6 seconds. At 3 mL/s, more image manipulation was required to see small vascular structures. One-second X-ray delay combined with 6-second injection duration provided the best arterial depiction of intracranial vessels from start to end of rotational angiography. Maximal rotational resolution was with a 17-cm field of view. Identification of aneurysms and small vessels was equivalent at all injection rates. Aneurysm detection was equivalent with rotational angiography and DSA. In 9 of 31 aneurysms, the neck was defined more clearly with rotational angiography than with DSA, compared with 2 of 31 that were seen better with DSA. Aneurysms of the intracranial internal carotid circulation were seen with rotational angiography and not DSA in 12 of 41 cases. No change was noted in clinical or laboratory findings. CONCLUSION: Rotational angiography provided better definition of the aneurysmal neck and greater clarity of aneurysms than did DSA; it also improved the level of confidence in predicting the presence or absence of aneurysms, especially in the anterior communicating artery; however, in our small series it did not significantly increase the detection of aneurysms. Prolonged injection angiography was well tolerated in all patients.     

Rotational digital subtraction carotid angiography: technique and comparison with static digital subtraction angiography

To compare the efficiency of sperm preparation between the two-layer Percoll gradient and mini-Percoll methods, 50 normal and 33 abnormal semen samples from male partners of infertile couples were studied. The number of recovered spermatozoa, percentage of motility, percentage of normal morphology, and their survival at 24 and 48 hours were assessed. Both Percoll gradient techniques resulted in a significantly higher percentage of motility and percentage of normal morphology compared with the original semen samples (p < 0.0001). The two-layer Percoll gradient showed a higher sperm recovery than the mini-Percoll method (p < 0.001), but the latter resulted in a higher percentage of motility (p > 0.001) and a higher sperm survival rate at 24 hours (p < 0.05) than the former, regarding normal semen samples. These differences did not appear with abnormal semen samples when analyzed as a group. Considering each of the abnormal parameters separately, sperm recovery was significantly higher after the two-layer Percoll gradient in the case of astheno- and teratozoospermia (p < 0.05), but sperm survival at 48 hours was higher after the mini-Percoll gradient in the case of teratozoospermia (p < 0.05). It is concluded that both the two-layer Percoll gradient and mini-Percoll method can be used effectively for sperm preparation. The former yields a higher sperm recovery, but the latter should be considered regarding teratozoospermic samples and semen samples of very low volume.     

Digital subtraction angiography with carbon dioxide in severe arterial ischemia and allergy to iodinated compounds

When in some selected patients, a direct arterial surgery (DAS) procedure or an endoluminal surgery (ES) are required for a chronic arterial ischemia (III or IV degrees), and an arteriography with contrast is absolutely contraindicated (because of severe renal failure without hemodialysis program or a severe congestive heart failure or a hyperthyroidism or a seriously demonstrated hypersensibility against the contrast agents); an angiography by digital subtraction with carbon dioxide (DIVAS-CO2) is indicated. This technique provides good quality images with minimal risks for the patient and an adequate study for ulterior treatment. We report a case of a 67-years-old woman, with diabetes-II, ischemic cardiopathy, arterial hypertension and a demonstrated hypersensibility against the iodide compounds. The patient was admitted because of a chronic ischemia (IV degree) with ischemic ulcerations on some fingers from the left foot. High doses of analgesic drugs were needed. Because the hypersensibility against the iodide compounds, an angiography with CO2 was carried out. The good quality images provided by this technique showed the factibility of a revascularization.     

MR angiography of the head and neck

A review of the basic physics and techniques for acquiring and evaluating magnetic resonance angiograms is provided, including time-of-flight and phase contrast techniques. Magnetic resonance (MR) angiography is becoming a routine method of evaluating carotid bifurcation atherosclerotic disease in both a screening and diagnostic capacity. The expanding clinical utility of MR angiography in the detection of intracranial aneurysms, characterization of arteriovenous malformations, and evaluation of intracranial atherosclerotic disease are also reviewed. Furthermore, MR angiography allows for the noninvasive diagnosis of arterial dissection. Magnetic resonance venography also allows the confirmation of the previously elusive and likely underdiagnosed entity of cerebral venous thrombosis.     

Lower extremity angiography: improved image quality and outflow vessel detection with bilaterally antegrade selective digital subtraction angiography. A blinded prospective intraindividual comparison with aortic flush digital subtraction angiography

RATIONALE AND OBJECTIVES: To introduce routine bilaterally antegrade selective stationary digital subtraction angiography (DSA), and prospectively compare it with unselective stationary DSA in the detection of calf arteries and assess additional time and complication rate. METHODS: Twenty-five patients received one unselective and two separate antegrade selective studies of each calf. Images were evaluated for image quality, number of depicted run-off vessels, and potential crural bypass recipient arteries. RESULTS: Bilaterally antegrade selective DSA was significantly superior in image quality and motion artifacts (P < 0.01). The number of adequately depicted run-off arteries per calf increased from 79% (2.37 of 3) to 96% (2.89 of 3) for legs with advanced peripheral vascular disease (PVD). Seventy-nine instead of 62 potential bypass recipients were identified (P = 0.002). Mean procedure time needed for selective catheterizations was 7 minutes. No adverse events were seen. CONCLUSIONS: Bilaterally antegrade selective DSA clearly is superior to aortic run-off DSA depicting tibial arteries. It requires comparatively small additional effort. Outflow vessel detection essentially is independent of advanced PVD.     

Three-dimensional high-resolution dynamic contrast-enhanced MR angiography of the pelvis and lower extremities with use of a phased array coil and subtraction: diagnostic accuracy

In this study, our purpose was to compare the high-resolution contrast-material-enhanced three-dimensional subtraction MR angiography with conventional angiography for occlusive disease in the pelvic and lower extremity arteries. A three-dimensional fast-imaging with steady precession (FISP) sequence with a 256 x 512 matrix was obtained on 1.5T MR unit using a phased array coil. Twenty patients with arteriosclerotic obstructive disease underwent subtraction dynamic contrast-enhanced MR angiography. In 15 patients, three regions (pelvis, upper knee, and lower knee) were sequentially obtained after repeated injection of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). In the other five patients, one region was imaged (total of 50 examinations); a maximum-intensity projection (MIP) algorithm was used for subtracted images. All patients also underwent conventional angiography. Angiographic images were divided into several anatomical segments. Three blinded radiologists independently graded a total of 50 anatomic segments with stenotic or obstructive diseases and 90 segments without disease. Subtracted images allowed resolution of small branch vessels in all examinations, although misregistration was seen in eight examinations of five patients. All arteries larger than 1 mm in diameter were visualized on subtracted images. For detection of significant stenosis (>50%), MR angiography had 96% sensitivity and 83% specificity. The correlation coefficient of degree of agreement between MR angiography and conventional angiography was .92. Stenotic vessels tended to be overestimated. We conclude that high-resolution dynamic contrast-enhanced three-dimensional MR angiography is capable of depicting small vessel anatomy of the pelvis and lower extremities. Sequential MR angiography of different regions was feasible by repeated injection of Gd-DTPA and subtraction. This technique is highly sensitive in detecting lesions, but stenosis tended to be overestimated.     

Second-generation three-dimensional reconstruction for rotational three-dimensional angiography

RATIONALE AND OBJECTIVES: The purpose of this study was to assess the feasibility and accuracy of three-dimensional (3D) reconstruction techniques for digital subtraction angiography (DSA) in planning and evaluation of minimally invasive image-controlled therapy. MATERIALS AND METHODS: Using a standard, commercially available system, the authors acquired DSA images and corrected them for inherent distortions. They designed and implemented parallel and multiresolution versions of cone-beam reconstruction techniques to reconstruct high-resolution targeted volumes in a short period of time. Testing was performed on anatomically correct, calibrated in vitro models of a cerebral aneurysm. These models were used with a pulsatile circulation circuit to allow for blood flow simulation during DSA, computed tomographic (CT) angiography, and magnetic resonance (MR) angiography image acquisitions. RESULTS: The multiresolution DSA-based reconstruction protocol and its implementation allowed the authors to achieve reconstruction times and levels of accuracy for the volume measurement of the aneurysmal cavities that were considered compatible with actual clinical practice. Comparison with data obtained from other imaging modalities shows that, besides vascular tree depiction, the DSA-based true 3D technique provides volume estimates at least as good as those obtained from CT and MR angiography. CONCLUSION: The authors demonstrated the feasibility and potential of true 3D reconstruction for angiographic imaging with DSA. On the basis of the model testing, this work addresses both the timing and quantification required to support minimally invasive image-controlled therapy.     

Diagnostic impact of four postprocessing techniques in evaluating contrast-enhanced three-dimensional MR angiography

OBJECTIVE: The purpose of this study was to determine the added diagnostic value of various three-dimensional (3D) data viewing techniques when analyzing contrast-enhanced 3D MR angiography. MATERIALS AND METHODS: Twenty patients (mean age, 62 years) with symptomatic peripheral vascular disease were assessed with breath-hold, contrast-enhanced 3D MR angiography and catheter angiography, which served as the standard of reference. After an initial interpretation of the 3D MR angiographic data sets based only on standardized maximum intensity projections (MIP), the diagnostic gain of the stepwise addition of interactive multiplanar reformations, shaded-surface displays (SSD), and virtual intraarterial endoscopy (VIE) images was calculated. Time required for each step of postprocessing was measured. RESULTS: Pathologic changes were revealed by catheter angiography in 60 vascular segments (50 severe stenoses, seven aneurysms, and three occlusions). The average postprocessing times were MIP, 8 min (range, 5-12 min); multiplanar reformations, 9 min (range, 3-11 min); SSD, 15 min (range, 8-25 min); and VIE, 40 min (range, 18-63 min). Addition of multiplanar reformations to MIPs resulted in the greatest gain of diagnostic accuracy, from 92% to 96%, and diagnostic confidence. When analysis was based on all four techniques, receiver operating characteristic curve analysis revealed only minimal improvements in diagnostic confidence, whereas diagnostic accuracy remained unchanged at 96%. CONCLUSION: Accurate and time-effective analysis of contrast-enhanced 3D MR angiography should be based on MIP algorithms and multiplanar reformations. Additional evaluation with VIE or SSD techniques is time-consuming and provides little diagnostic gain.     

Gadolinium-enhanced magnetic resonance angiography of abdominal blood vessels

Contrast enhanced (CE) magnetic resonance angiography (MRA) provides high resolution angiograms within 20-40 sec. The technique is based on the acquisition of heavily T1-weighted three-dimensional (3D) gradient-echo data sets (FISP) with ultrashort echo-(< 2ms) and repetition times (< 5 ms) during arterial phase of an intravenously injected bolus of a T1-shortening agent such as Gd-DTPA. For MR-angiography of abdominal vessels CE-MRA is better suited than "time-of flight" (TOF) and phase-contrast (PC) MRA because motional artifacts can be obviated with breath-held acquisitions. We have optimised the technique and evaluated its potential for angiography of the abdominal aorta and its branches as well as the portal vein and its tributaries. Whilst CE-MRA provides reliable diagnostic accuracy in the aorta and the proximal sections of its branches, small peripheral arteries cannot be assessed accurately. The portal vein and its tributaries can often be depicted better with CE-MRA than with conventional angiography but, like conventional angiography, CE-MRA is hampered by slow and reversed flow, conditions under which TOF or "true FISP" MRA may perform bst. We have also investigated FLASH-echo-planar imaging (EPI) hybrid techniques, a further technical development which due to shorter acquisition times of 12-15 sec. allows semi-dynamic imaging of the arterial and venous phase and provide better vessel contrast due to the use of fat-suppression.     

Role of CT angiography in the preoperative evaluation for laparoscopic nephrectomy

Laparoscopic nephrectomy (LN) was recently introduced as a minimally invasive alternative to open nephrectomy in living related renal donation. Because of the limited field of view available with laparoscopic techniques, the role of preoperative radiologic evaluation in LN has expanded to include anatomic definition of the renal arteries, collecting system, renal parenchyma, and renal venous anatomy. Computed tomographic (CT) angiography has proved to be a minimally invasive alternative to conventional angiography in the preoperative evaluation of living related renal donors. CT angiography has been shown to have an accuracy comparable to that of conventional angiography in predicting renal arterial anatomy. In addition, CT angiography provides comprehensive definition of the renal vascular anatomy including the location, size, and length of the renal, adrenal, gonadal, and lumbar veins. Dual-phase spiral CT combined with three-dimensional CT angiography constitute a single, minimally invasive procedure that can provide a complete preoperative evaluation of potential living related renal donors prior to LN. Comprehensive anatomic depiction of the renal arterial and venous supplies aids in surgical planning and helps avoid potential complications.