Stent Graft Sizing Research Articles

Importance of dynamic aortic evaluation in planning TEVAR.

Dynamic aortic evaluation in planning thoracic endovascular aortic repair (TEVAR) is important to provide optimal stent graft sizing. Static imaging protocols do not consider normal aortic dynamics and may lead to stent graft to aorta mismatch, causing stent graft related complications, such as type I endoleak and stent graft migration. Dynamic imaging can assist in accurate stent graft selection and sizing preoperatively, and evaluate stent graft performance during follow-up. To create new imaging technologies, integration of knowledge between diverse scientific fields is essential (i.e., engineering, informatics and medicine). Different dynamic imaging modalities, such as electrocardiographic-gated computed tomography angiography (ECG-gated CTA) and four-dimensional phase-contrast MRI (4D PC-MRI), are progressively investigated and implemented into clinical practice as important instruments in preoperative planning for TEVAR. In time, further application of dynamic imaging tools for preoperative screening and follow-up after TEVAR might lead to better outcomes for patients. The advances in dynamic imaging for evaluation of the thoracic aorta using new imaging modalities and their future perspectives are addressed in this manuscript.

Stent graft visualization and planning tool for endovascular surgery using finite element analysis

A new approach to optimize stent graft selection for endovascular aortic repair is the use of finite element analysis. Once the finite element model is created and solved, a software module is needed to view the simulation results in the clinical work environment. A new tool for interpretation of simulation results, named Medical Postprocessor, that enables comparison of different stent graft configurations and products was designed, implemented and tested. Aortic endovascular stent graft ring forces and sealing states in the vessel landing zone of three different configurations were provided in a surgical planning software using the Medical Imaging Interaction Tool Kit (MITK) software system. For data interpretation, software modules for 2D and 3D presentations were implemented. Ten surgeons evaluated the software features of the Medical Postprocessor. These surgeons performed usability tests and answered questionnaires based on their experience with the system. The Medical Postprocessor visualization system enabled vascular surgeons to determine the configuration with the highest overall fixation force in 16+/-6 s, best proximal sealing in 56+/-24s and highest proximal fixation force in 38+/- s. The majority considered the multiformat data provided helpful and found the Medical Postprocessor to be an efficient decision support system for stent graft selection. The evaluation of the user interface results in an ISONORM-conform user interface (113.5 points). The Medical Postprocessor visualization software tool for analyzing stent graft properties was evaluated by vascular surgeons. The results show that the software can assist the interpretation of simulation results to optimize stent graft configuration and sizing.

Delayed Intimal Blowout after Endovascular Repair of Aortic Dissection

The authors have seen four cases of asymptomatic delayed intimal injury adjacent to a stent graft diagnosed 7 to 16 months after thoracic endovascular aortic repair. Endovascular repeat intervention was successfully performed in three of the four cases as described in the present report. A second consecutive “intimal blowout” in one patient remains under close radiologic surveillance. Possible causes for the intimal blowouts, including stent-graft size, landing zone anatomy, and intrinsically weak aortic tissue, are discussed.

Contemporary Role of Computational Analysis in Endovascular Treatment for Thoracic Aortic Disease.

In the past decade, thoracic endovascular aortic repair (TEVAR) has become the primary treatment option in descending aneurysm and dissection. The clinical outcome of this minimally invasive technique is strictly related to an appropriate patient/stent graft selection, hemodynamic interactions, and operator skills. In this context, a quantitative assessment of the biomechanical stress induced in the aortic wall due to the stent graft may support the planning of the procedure. Different techniques of medical imaging, like computed tomography or magnetic resonance imaging, can be used to evaluate dynamics in the thoracic aorta. Such information can also be combined with dedicated patient-specific computer-based simulations, to provide a further insight into the biomechanical aspects. In clinical practice, computational analysis might show the development of aortic disease, such as the aortic wall segments which experience higher stress in places where rupture and dissection may occur. In aortic dissections, the intimal tear is usually located at the level of the sino-tubular junction and/or at the origin of the left subclavian artery. Besides, computational models may potentially be used preoperatively to predict stent graft behavior, virtually testing the optimal stent graft sizing, deployment, and conformability, in order to provide the best endovascular treatment. The present study reviews the current literature regarding the use of computational tools for TEVAR biomechanics, highlighting their potential clinical applications.

Factors predictive of distal stent graft-induced new entry after hybrid arch elephant trunk repair with stainless steel–based device in aortic dissection

Stent graft-induced new entry (SINE) has been increasingly observed after thoracic endovascular aortic repair of aortic dissection. We illustrate the possible mechanism by exploring predictive factors of late distal SINE after hybrid arch elephant trunk repair for aortic dissection. From November 2006, to May 2011, 20 of 99 patients underwent hybrid arch repair using the elephant trunk graft as the proximal landing zone. After a mean follow-up period of 27.9 ± 12.0 months, 12 patients had late distal SINE events and the others were free of events. False lumen remodeling level was observed and maximal longitudinal diameter, average of longitudinal and transverse maximal diameter, circumference, and area of true lumen were analyzed for precise size selection of stent graft before and after the procedure. Taper ratio, true lumen:aorta ratio, prestent grafting oversizing ratio, poststent grafting oversizing ratio, and expansion mismatch ratio of distal true lumen were proposed and calculated for further evaluation of the mechanism of late distal SINE. Only the area oversizing ratio between true lumen and the distal selected stent graft at the presumed distal end of stent grafting was found as a significant predictive factor of SINE before procedure (4.00 ± 2.96 vs 1.98 ± 0.66 for SINE vs non-SINE, respectively; P = .031). The significant difference of the expansion mismatch ratio of true lumen between the 2 groups was found not only in the size measurement of mean diameter (1.48 ± 0.29 vs 1.22 ± 0.15; P = .039), but also in the area (2.39 ± 0.85 vs 1.58 ± 0.42; P = .031) and circumference (1.43 ± 0.27 vs 1.18 ± 0.14; P = .016) after stent grafting. We found that taper ratio is not an optimal criteria for stent graft size selection and distal oversizing calculated by true-lumen area is a significant factor causing delayed distal SINE. Use of the prestenting area oversizing ratio should be limited.

Thoracic stent graft sizing for frozen elephant trunk repair in acute type A dissection

Although stenting of the descending aorta simultaneously with proximal aortic repair has become an accepted part of the therapy for acute type A dissection, no general recommendations have been accepted regarding the choice of diameter and length of the stent grafts. The present study explored the safety and effectiveness of sizing the stent graft of the hybrid prosthesis in relation to the total aortic diameter and extending the landing zone to the level of the T10-T12 vertebrae. The frozen elephant trunk procedure was performed on 32 patients with acute type A aortic dissection. The stent graft size was chosen according to the total aortic diameter measured on contrast-enhanced computed tomography scans. The stent graft was inserted with the distal landing zone at the level of vertebrae T10-T12. All patients underwent computed tomography or magnetic resonance angiography before discharge; 8 patients underwent subsequent endovascular stent extension. The 30-day survival was 100%, with 3.1% (1/32) overall mortality at 17 ± 4 months (range, 1-33) of follow-up. The postoperative complications included pneumonia in 5, pulmonary embolism in 3, sepsis in 1, and permanent recurrent laryngeal nerve damage in 1 patient. No ischemic brain or spinal cord injury occurred. During follow-up, no endoleaks or false lumen patency developed. Sizing the stent graft of the hybrid prosthesis according to the total aortic diameter and choosing a distal landing zone between vertebrae T10 and T12 is safe, with low midterm mortality and morbidity. It allows an extensive repair of the dissected aorta with early definite occlusion of the false lumen and prepares for potential endovascular extension of the graft.

A morphologic study of chronic type B aortic dissections and aneurysms after thoracic endovascular stent grafting

The long-term results of treating chronic aortic dissections and aneurysms in association with dissections with thoracic endovascular aortic repair (TEVAR) are unknown, and the timing for intervention is uncertain. We evaluated the morphology of stent graft and aorta remodeling and the volumetric changes in these patients after successful TEVAR. Serial computed tomography scans of 32 patients who underwent TEVAR for uncomplicated chronic dissections (group A, n = 17) and chronic dissections with aneurysms (group B, n = 15) were analyzed at 1, 6, 12, and 36 months. Stent graft diameter changes and positional migration were assessed three-dimensionally using Mimics 14.0 (Materialize, Leuven, Belgium). Volumetric data for true lumen, false lumen, thrombus load, and aortic size were measured by Aquarius iNtuition 4.4 software (TeraRecon, San Mateo, Calif). Results were compared between the two groups and with stent graft diameter, length, and oversizing. Aortic stent grafts remodeled progressively, with inlet area increasing 4.4%, 10.1%, and 14.2% and outlet area increasing 42.6%, 67.2%, and 72.3%, respectively, at 6, 12, and 36 months. True lumen volume increased progressively in group A (114 to 174 mL) and group B (124 to 190 mL) from baseline to 36 months. False lumen volume decreased in group A (150 to 88 mL) and group B (351 to 250 mL), whereas thrombus load in the false lumen increased from 73% to 80% in group A and 84% to 87% in group B in 3 years. Eight patients (4 in each group) showed an increase in total aortic volume of >10%, 12 showed a static volume, and 12 showed shrinkage. Aortic volume change had no relationship to pathology, stent graft sizing, and thrombus load but was positively associated with the placement of a longer graft. A small but progressive distal migration of stent grafts was noted in all patients (3.1, 4.5, and 5.1 mm at 6, 12, and 36 months) but was more prominent in shorter stent grafts (≤ 162 mm). No deaths, rupture, or secondary interventions occurred during follow-up. Aortic remodeling after TEVAR in chronic dissection is a continuous process. There were no significant differences between chronic dissections and aneurysms in all volumetric parameters. Treating chronic dissections early, before aneurysm formation, did not appear to have a morphologic advantage.

A Morphologic Study of Chronic Type B Aortic Dissections and Aneurysms after Thoracic Endovascular Stent Grafting

The long-term results of treating chronic aortic dissections and dissecting aneurysms with thoracic endovascular aortic repair (TEVAR) are unknown, and the timing for intervention uncertain. We aim to evaluate the morphology of stent graft and aorta remodeling, and the volumetric changes in these patients after successful TEVAR. Serial computed tomography (CT) scans of 32 patients who had TEVAR for uncomplicated chronic dissections (group A, n = 17) and dissecting aneurysms (group B, n = 15) were analyzed at 1, 6, 12, and 36 months. Stent graft diameter changes and positional migration were assessed 3-dimensionally using Mimics 14.0 (Materialize, Leuven, Belgium). Volumetric data for true lumen, false lumen, thrombus load, and aortic size were measured by Aquarius Nutrition 4.4 (TeraRecon, San Mateo, Calif). Results were compared between the two groups and with stent graft diameter, length, and oversizing. Aortic stent graft remodeled progressively with inlet area increased 4.4%, 10.1%, and 14.2% and outlet area increased 42.6%, 67.2%, and 72.3% at 6, 12, and 36 months. True lumen volume increased progressively in both group A (114 mL to 174 mL), and group B (124 mL to 190 mL) from baseline to 36 months. False lumen volume decreased in group A (150 mL to 88 mL) and group B (351 mL to 250 mL), respectively; while total thrombus load in the false lumen increased from 73% to 80% for group A and 84% to 87% in group B in 3 years. Eight patients (4 in each group) showed an increase in total aortic volume of >10%. Twelve patients showed a static volume and 12 patients showed a shrinkage. Aortic volume change had no relationship to pathology, stent graft sizing, and thrombus load, but was positively associated with the placement of a longer graft. There was a small but progressive distal migration of stent grafts in all patients (3.1, 4.5, and 4.6 mm at 6, 12, and 36 months), more prominent in shorter stent grafts (<160 mm). No mortality, rupture, or secondary interventions occurred during follow-up. Aortic remodeling after TEVAR in chronic dissection is a continuous process. There were no significant differences between chronic dissections and aneurysms in all volumetric parameters. Treating chronic dissections early before aneurysm formation did not seem to have a morphologic advantage.

Thoracic Aortic Pulsatility Decreases During Hypovolemic Shock:Implications for Stent-Graft Sizing

To investigate the thoracic aortic pulsatility during hypovolemic shock in an experimental porcine model. The circulating blood volume of 7 healthy Yorkshire pigs was gradually lowered until the subjects had lost 40% of their normal blood volume. Intravascular ultrasound was used to assess the aortic pulsatility in normovolemic and hypovolemic state at the level of the ascending and descending thoracic aorta. The mean aortic pulsatility at the level of the ascending aorta decreased from 15.9% ± 7.2% (range 6.3%-25.7%) in normovolemia to 6.2% ± 2.8% (range 2.9%-10.7%, p = 0.018) in hypovolemia. At the level of the descending thoracic aorta, the mean aortic pulsatility decreased from 8.7% ± 2.8% (range 4.4%-12.2%) at baseline to 5.6% ± 2.5% (range 1.5%-9.5%, p = 0.028) in hypovolemia. The maximum mean aortic diameter, obtained in cardiac systole, was significantly smaller as well at both evaluated levels during hypovolemic shock compared with the mean diameter in normovolemia. The thoracic aortic diameter and pulsatility decreased significantly during hypovolemic shock in this porcine model, most impressively at the level of the ascending aorta. Electrocardiographically-gated imaging may not be necessary for hypovolemic patients with acute aortic disease requiring endovascular repair because of the minimal aortic pulsatility.

CT Angiography in Stent-Graft Sizing: Impact of Using Inner vs. Outer Wall Measurements of Aortic Neck Diameters

To assess the impact of using inner wall vs. outer wall measurements on stent-graft sizing for endovascular repair of abdominal aortic aneurysm (AAA). Preoperative static and electrocardiographically-gated 64-slice computed tomographic angiography (CTA) datasets were acquired on 40 consecutive AAA patients (29 men; mean age 78.9 ± 6 years, range 75-89). On static images, the aortic neck diameters were manually measured twice by 2 readers at 3 clinically relevant levels (supra-, juxta-, and infrarenal). The measurements were obtained from intima-to-intima (inner wall) and from adventitia-to-adventitia (outer wall). Dynamically reconstructed scans were also reviewed in each phase of the cardiac cycle to identify inner and outer minimum/maximum diameters. Using inner and outer wall measurements performed on static images, readers selected the size of a stent-graft that required inner neck diameter measurements and then one that required outer wall diameters. To calculate the relative oversizing, each selected stent-graft size was compared to that obtained using dynamic measurements. Oversizing <4% or >30% was considered inadequate. Mean variations for the inner and outer wall diameters of 9.75% ± 4.01% and 8.66% ± 3.71%, respectively, were recorded on static CTAs; the absolute changes in diameters were 1.82 ± 0.63 mm and 1.91 ± 0.64 mm, respectively. No statistically significant differences were found relative to aortic pulsatility at the 3 levels in the neck for the inner or outer wall diameters. Significant variability was seen between inner (mean 20.8 ± 3.4 mm) vs. outer (mean 23.7 ± 4.3 mm; p < 0.05) wall diameters. Stent-graft sizes significantly changed on the basis of the measurement method and device; for example, using the outer diameter to size a stent-graft that requires an inner diameter reference changed 36% of the selected stent-graft sizes, with ~20% being excessively oversized. Conversely, using the inner diameter to size an outer-diameter-based stent-graft resulted in nearly 40% of the sizes being altered. Based on dynamic measurements, the changes were more dramatic: the oversizing was considered excessive in up to 90% of patients if the measurement method did not match the stent-graft's stipulated reference. These data suggest that stent-graft sizing should follow the manufacturer's recommendations for using inner or outer diameter references based on dynamic patterns (mean value between diastolic and systolic diameters suggested).

Double-Barreled Cannon Stent Grafts: Possible Solution for Extremely Dilated Landing Zone of Aorta

Anatomical limitations have been identified as barriers to the more widespread application of thoracic endovascular aortic repair. Here, we report a case in which a novel technique was used as a solution for an extremely dilated aortic landing zone. An elderly gentleman in profound shock was diagnosed with a ruptured distal aortic arch aneurysm. Open repair was considered, but owing to the presence of multiple comorbidities and an extremely dilated aorta in the landing zone (45 mm) which made thoracic endovascular aortic repair infeasible, it appeared to entail a high risk for perioperative morbidity and mortality. Therefore, to save the patient's life, we designed a novel double-barreled cannon thoracic endovascular aortic repair method, and further developed a formula for choosing appropriate stent graft sizes. The patient gradually recovered to baseline physical status after the operation.

Invited commentary

Invited commentary

Pulsatility in the Iliac Artery Is Significant at Several Levels: Implications for EVAR

To evaluate the pulsatility of the iliac arteries and compare their distension at several levels that might influence preoperative stent-graft sizing and the long-term durability of stent-graft sealing and fixation. Preoperative dynamic computed tomographic angiography (CTA) scans of 30 patients (24 men; median age 75 years, range 60-85) with an abdominal aortic aneurysm and patent iliac arteries were included. The CTAs consisted of 8 images per heartbeat. Bilateral diameter and area changes per heartbeat were measured semi-automatically in the common iliac artery (CIA) at 3 levels: (A) 0.5 cm after the aortic bifurcation, (B) in the middle of the CIA, and (C) 0.5 cm proximal to the iliac bifurcation. Pulsatility was defined as the largest difference in area and average diameter change over 180 axes per heartbeat. Pulsatility at the 3 levels was compared, and the intraobserver variability of the method was calculated according to Bland and Altman. The mean area increases in the CIAs at levels A, B, and C were 12.5% (16.3 mm²), 11.2% (13.6 mm²), and 9.6% (12.6 mm²), respectively, and the mean iliac diameter increases were 9.2% (1.1 mm), 8.5% (1.0 mm), and 8.1% (1.0 mm). The iliac distension was statistically significant at all levels. The iliac distension at level A was statistically significantly larger than the distension at level C. The intraobserver variability was 13.3 mm² for area and 0.6 mm for diameter measurements. The pulsatility in the iliac arteries is statistically significant at several levels relevant to endovascular aneurysm repair. The distension of the iliac artery possibly decreases more distally, which might encourage the extension of stent-grafts to the internal iliac artery.

Endovascular aneurysm repair for ruptured abdominal aortic aneurysm: The Albany Vascular Group approach

Improvements in endovascular technology and techniques have allowed us to treat patients in ways we never thought possible. Today, endovascular treatment of ruptured abdominal aortic aneurysms is associated with markedly decreased morbidity and mortality compared with the open surgical approach, yet there are several fundamental obstacles in our ability to offer these endovascular techniques to most patients with ruptured aneurysms. This article will focus on the technical aspects of endovascular aneurysm repair for rupture, with particular attention to developing a standardized multidisciplinary approach that will help vascular surgeons deal with not just the technical aspects of these procedures but also address some of the challenges, including the availability of preoperative computed tomography, the choice of anesthesia, the percutaneous vs femoral cutdown approach, use of aortic occlusion balloons, need for bifurcated vs aortouniiliac stent grafts, need for adjunctive procedures, diagnosis and treatment of abdominal compartment syndrome, and conversion to open surgical repair.

Commentary: Dynamics of the Aorta and the Influence on Stent-Graft Sizing

Commentary: Dynamics of the Aorta and the Influence on Stent-Graft Sizing

Intravascular ultrasound with a vector phased-array probe (acunav) is feasible in endovascular abdominal aortic aneurysm repair

The ideal imaging method for endovascular aneurysm repair (EVAR) should provide all data regarding diagnosis, measurements, and guiding of stent-graft deployment. Contrast-enhanced computed tomography (CT) is used for preoperative EVAR planning, together with intraoperative angiography. However, the administered contrast volume might result in contrast-induced nephropathy (CIN). To develop a technique for aortic measurements, vessel wall evaluation, and stent-graft positioning by using a vector phased-array intravascular ultrasound probe with color Doppler function (AcuNav) in elective EVAR. Thirteen elective EVAR patients were included. AcuNav was compared to pre- and postoperative CT examinations, perioperative angiography, and postoperative duplex. Measurements for stent-graft sizing were easily obtained and facilitated by the color Doppler function and corresponded well with CT and angiography. The combined information from AcuNav and fluoroscopy provided exact positioning of the stent graft. An aortic placement of the probe provided superior imaging results compared to an inferior vena cava approach. Detection of endoleak was found to be difficult. No complications were registered. The use of AcuNav combined with fluoroscopy in EVAR was found to be safe, effective, and feasible in planning and guiding EVAR procedures. Best results were seen with the probe placed in the artery. AcuNav might be used to replace contrast-enhanced CT and angiography, hence reducing the risk of CIN, especially in high-risk patients.

Endovascular Thoracic Aortic Aneurysm Repair:Evaluating the Utility of Intravascular Ultrasound Measurements

To compare intravascular ultrasound (IVUS) and computed tomography (CT) measurements of aortic diameter for the determination of stent-graft sizes used in thoracic endovascular aneurysm repair (TEVAR). A retrospective review was conducted of 71 IVUS measurements performed in 33 patients (17 men; mean age 69 years) undergoing endovascular repair for thoracic aortic aneurysm (TAA). For comparison, an inanimate model of the aortic arch and the great vessels was created; 5 independent operators took multiple blinded IVUS measurements. Measurement accuracy is presented as the mean and coefficient of variance in percent. In 47 (66%) of the 71 clinical measurements, IVUS yielded a value that was larger than the CT scan measurement; in 8 (11%), the difference was at least 5 mm. In the model, CT centerline measurements were accurate within a mean 0.3 mm (0.6%) of the actual diameter; IVUS measurements were accurate within a mean 1.4 mm (2.8%). Centerline IVUS measurements increased the accuracy to within 0.8 mm (1.8%) of the actual diameter. IVUS measurements of the thoracic aorta were larger than CT measurements 66% of the time. However, there are 2 concerns with IVUS: off-center measurements distort the image and tangential measurements on a curve do not reflect a true centerline diameter. Thus, off-center IVUS measurements or those taken in the tortuous portion of the aorta may not be as accurate as centerline CT measurements.

Analysis of biomechanical factors affecting stent-graft migration in an abdominal aortic aneurysm model

Focusing on a representative abdominal aortic aneurysm (AAA) with a bifurcating stent-graft (SG), a fluid–structure interaction (FSI) solver with user-supplied programs has been employed to solve for blood flow, AAA/SG deformation, sac pressure and wall stresses, as well as the downward forces acting on the SG. Simulation results indicate that implanting a SG can significantly reduce sac pressure, mechanical stress, pulsatile wall motion, and maximum diameter change in AAAs; hence, it may restore normal blood flow and prevent AAA rupture effectively. The transient SG drag force is similar in trend as the cardiac pressure. Its magnitude depends on multi-factors including blood flow conditions, as well as SG and aneurysm geometries. Specifically, AAA neck angle, iliac bifurcation angle, neck aorta-to-iliac diameter ratio, SG size, and blood waveform play important roles in generating a fluid flow force potentially leading to SG migration. It was found that the drag force can exceed 5 N for an AAA with a large neck or iliac angle, wide aortic neck and narrow iliac arteries, large SG size, and/or abnormal blood waveform. Thus, the fixation of self-expandable or balloon-expandable SG contact may be inadequate to withstand the forces of blood flowing through the implant and hence means of extra fixation should be considered. A comprehensive FSI analysis of the coupled SG–AAA dynamics provides physical insight for evaluating the luminal hemodynamics, and maximum AAA-stresses as well as biomechanical factors leading potentially to SG migration.

Intravascular ultrasound aids in the performance of endovascular repair of abdominal aortic aneurysm.

The purpose of this retrospective review was to assess the accuracy of aortic measurements with intravascular ultrasound scan (IVUS) compared with computed tomographic (CT) scan and to assess the role of IVUS in the performance of endovascular repair of abdominal aortic aneurysms (AAAs). Seventy-eight patients undergoing repair of AAA with the AneuRx stent graft (Medtronic AVE, Inc, Santa Rosa, Calif) underwent measurement with CT scan and IVUS. The initial selection of stent graft size was made on the basis of the CT scan measurements, but the final decision for size was made on the basis of the IVUS measurements. Standard measurements of a phantom tube obtained with IVUS, CT scan, and digital caliper were also compared. IVUS measurements of the phantom standard agreed closely with CT scan measurements. However, stent graft size initially selected with CT measurement was altered in 28% of cases on the basis of intraoperative IVUS measurements. No type I endoleaks were encountered in our series, and no aortic cuffs were necessary for endoleak repair. IVUS accurately measures the aorta for selection of stent grafts for endovascular repair of AAA and may prevent type I endoleaks and remedial procedures for their repair.

Measurements Before Endovascular Repair Of Abdominal Aortic Aneurysms. MR imaging with MRA vs. angiography and CT

1) To compare measurements obtained with MR imaging (MRI)/contrast-enhanced MR angiography (CE MRA) with measurements obtained with angiography (DSA) and CT, for stent-graft sizing of abdominal aortic aneurysms (AAA). 2) To compare MRA measurements obtained with the two post processing techniques MIP (maximum intensity projection) and VRT (3D volume rendering technique). The prospective study included 20 consecutive patients with AAA identified by DSA and CT as suitable for endovascular repair. For the study, MRI/CE MRA was performed. Five measurement variables for stent-graft sizing were chosen. Comparisons were made between MRI/CE MRA, DSA and CT, and between observers. Comparisons were also made between MIP and VRT. Significantly shorter lengths were obtained with MRA-MIP than with DSA. Three out of six diameter measurements were significantly smaller on MRI/CE MRA than on DSA and CT. No significant differences were found between the observers. One diameter measurement was significantly smaller on MIP than on VRT, while the other measurements showed no significant differences. The length measurements obtained with MRA-MIP were probably more correct than those with DSA. For more reliable diameter measurements with CE MRA, improvements of the technique, including VRT reconstructions and a standardized determination of the vessel boundaries, are needed.