High Intravascular Signal Arterial Transit Time Artifacts Have Negligible Effects on Cerebral Blood Flow and Cerebrovascular Reserve Capacity Measurement Using Single Postlabel Delay Arterial Spin-Labeling in Patients with Moyamoya Disease.

BACKGROUND AND PURPOSE: Arterial spin-labeling-derived CBF values may be affected by arterial transit time artefacts. Thus, our aim was to assess to what extent arterial spin-labeling-derived CBF and cerebrovascular reserve capacity values in major vascular regions are overestimated due to the arterial transit time artifacts in patients with Moyamoya disease. MATERIALS AND METHODS: Eight patients with Moyamoya disease were included before or after revascularization surgery. CBF maps were acquired using a 3D pseudocontinuous arterial spin-labeling sequence, before and 5, 15, and 25 minutes after an IV acetazolamide injection and were registered to each patient's 3D-T1-weighted images. Vascular regions were defined by spatial normalization to a Montreal Neurological Institute-based vascular regional template. The arterial transit time artifacts were defined as voxels with high signal intensity corresponding to the right tail of the histogram for a given vascular region, with the cutoff selected by visual inspection. Arterial transit time artifact maps were created and applied as masks to exclude arterial transit time artifacts on CBF maps, to create corrected CBF maps. The cerebrovascular reserve capacity was calculated as CBF after acetazolamide injection relative to CBF at baseline for corrected and uncorrected CBF values, respectively. RESULTS: A total of 16 examinations were analyzed. Arterial transit time artifacts were present mostly in the MCA, whereas the posterior cerebral artery was generally unaffected. The largest differences between corrected and uncorrected CBF and cerebrovascular reserve capacity values, reported as patient group average ratio and percentage point difference, respectively, were 0.978 (95% CI, 0.968-0.988) and 1.8 percentage points (95% CI, 0.3-3.2 percentage points). Both were found in the left MCA, 15 and 5 minutes post-acetazolamide injection, respectively. CONCLUSIONS: Arterial transit time artifacts have negligible overestimation effects on calculated vascular region-based CBF and cerebrovascular reserve capacity values derived from single-delay 3D pseudocontinuous arterial spin-labeling.

Evaluation of the INTERPRET decision-support system: can it improve the diagnostic value of magnetic resonance spectroscopy of the brain?

PURPOSE: We evaluated in a clinical setting the INTERPRET decision-support system (DSS), a software generated to aid in MRS analysis to achieve a specific diagnosis for brain lesions. METHODS: The material consisted of 100 examinations of focal intracranial lesions with confirmed diagnoses. MRS was obtained at 1.5 T using TE 20-30 ms. Data were processed with the LCModel for conventional analysis. The INTERPRET DSS 3.1. was used to obtain specific diagnoses. MRI and MRS were reviewed by one interpreter. DSS analysis was made by another interpreter, in 80 cases by two interpreters. The diagnoses were compared with the definitive diagnoses. For comparisons between DSS, conventional MRS analysis, and MRI, the diagnoses were categorised: high-grade tumour, low-grade tumour, non-neoplastic lesion. RESULTS: Interobserver agreement in choosing the diagnosis from the INTERPRET database was 75%. The diagnosis was correct in 38/100 cases, incorrect in 57 cases. No good match was found in 5/100 cases. The diagnostic category was correct with DSS/conventional MRS/MRI in 67/58/52 cases, indeterminate in 5/8/20 cases, incorrect in 28/34/28 cases. Results with DSS were not significantly better than with conventional MRS analysis. All definitive diagnoses did not exist in the INTERPRET database. In the 61 adult patients with the diagnosis included in the database, DSS/conventional MRS/MRI yielded a correct diagnosis category in 48/32/29 cases (DSS vs conventional MRS: p = 0.002, DSS vs MRI: p = 0.0004). CONCLUSION: Use of the INTERPRET DSS did not improve MRS categorisation of the lesions in the unselected clinical cases. In adult patients with lesions existing in the INTERPRET database, DSS improved the results, which indicates the potential of this software with an extended database.

Guidelines for the use of magnetic resonance imaging in diagnosing and monitoring the treatment of multiple sclerosis: recommendations of the Swedish Multiple Sclerosis Association and the Swedish Neuroradiological Society.

Multiple sclerosis (MS) is associated with inflammatory lesions in the brain and spinal cord. The detection of such inflammatory lesions using magnetic resonance imaging (MRI) is important in the consideration of the diagnosis and differential diagnoses of MS, as well as in the monitoring of disease activity and predicting treatment efficacy. Although there is strong evidence supporting the use of MRI for both the diagnosis and monitoring of disease activity, there is a lack of evidence regarding which MRI protocols to use, the frequency of examinations, and in what clinical situations to consider MRI examination. A national workshop to discuss these issues was held in Stockholm, Sweden, in August 2015, which resulted in a Swedish consensus statement regarding the use of MRI in the care of individuals with MS. The aim of this consensus statement is to provide practical advice for the use of MRI in this setting. The recommendations are based on a review of relevant literature and the clinical experience of workshop attendees. It is our hope that these recommendations will benefit individuals with MS and guide healthcare professionals responsible for their care.

Pregnancy hypertensive disease and risk of dementia and cardiovascular disease in women aged 65 years or older: a cohort study.

OBJECTIVE: The primary aim was to study pregnancy hypertensive disease and subsequent risk of dementia. The second aim was to study if the increased risks of cardiovascular disease (CVD) and stroke after pregnancy hypertensive disease persist in an elderly population. DESIGN: Cohort study. SETTING: Sweden. POPULATION OR SAMPLE: 3232 women 65 years or older (mean 71 years) at inclusion. METHODS: Cox proportional hazards regression analyses were used to calculate risks of dementia, CVD and/or stroke for women exposed to pregnancy hypertensive disease. Exposure data were collected from an interview at inclusion during the years 1998-2002. Outcome data were collected from the National Patient Register and Cause of Death Register from the year of inclusion until the end of 2010. Age at inclusion was set as a time-dependent variable, and adjustments were made for body mass index, education and smoking. MAIN OUTCOME MEASURES: Dementia, CVD, stroke. RESULTS: During the years of follow-up, 7.6% of the women exposed to pregnancy hypertensive disease received a diagnosis of dementia, compared with 7.4% among unexposed women (HR 1.19; 95% CI 0.79 to 1.73). The corresponding rates for CVD were 22.9% for exposed women and 19.0% for unexposed women (HR 1.29; 95% CI 1.02 to 1.61), and for stroke 13.4% for exposed women and 10.7% for unexposed women (HR 1.36; 95% CI 1.00 to 1.81). CONCLUSIONS: There was no increased risk of dementia after self-reported pregnancy hypertensive disease in our cohort. We found that the previously reported increased risk of CVD and stroke after pregnancy hypertensive disease persists in an older population.

Magnetic resonance imaging-estimated placental perfusion in fetal growth assessment.

OBJECTIVE: To evaluate in-vivo placental perfusion fraction, estimated by magnetic resonance imaging (MRI), as a marker of placental function. METHODS: A study population of 35 pregnant women, of whom 13 had pre-eclampsia (PE), were examined at 22-40 weeks' gestation. Within a 24-h period, each woman underwent an MRI diffusion-weighted sequence (from which we calculated the placental perfusion fraction), venous blood sampling and an ultrasound examination including estimation of fetal weight, amniotic fluid index and Doppler velocity measurements. The perfusion fractions in pregnancies with and without fetal growth restriction were compared and correlations between the perfusion fraction and ultrasound estimates and plasma markers were estimated using linear regression. The associations between the placental perfusion fraction and ultrasound estimates were modified by the presence of PE (P < 0.05) and therefore we included an interaction term between PE and covariates in the models. RESULTS: The median placental perfusion fractions in pregnancies with and without fetal growth restriction were 21% and 32%, respectively (P = 0.005). The correlations between placental perfusion fraction and ultrasound estimates and plasma markers were highly significant (P = 0.002 and P = 0.0001, respectively). The highest coefficient of determination (R(2) = 0.56) for placental perfusion fraction was found for a model that included pulsatility index in the ductus venosus, plasma level of soluble fms-like tyrosine kinase-1, estimated fetal weight and presence of PE. CONCLUSION: The placental perfusion fraction has the potential to contribute to the clinical assessment of cases with placental insufficiency.

In vivo ³¹P-MR spectroscopy in normal pregnancy, early and late preeclampsia: a study of placental metabolism.

INTRODUCTION: Preeclampsia affects about 3% of pregnancies and the placenta is believed to play a major role in its pathophysiology. Lately, the role of the placenta has been hypothesised to be more pronounced in preeclampsia of early (<34 weeks) rather than late (≥ 34 weeks) onset. (31)P Magnetic Resonance Spectroscopy (MRS) enables non-invasive, in vivo studies of placental metabolism. Our aim was to study placental energy and membrane metabolism in women with normal pregnancies and those with early and late onset preeclampsia. METHODS: The study population included fourteen women with preeclampsia (five with early onset and nine with late onset preeclampsia) and sixteen women with normal pregnancy (seven with early and nine with late pregnancy). All women underwent a (31)P-MRS examination of the placenta. RESULTS: The phosphodiester (PDE) spectral intensity fraction of the total (31)P signal and the phosphodiester/phosphomonoester (PDE/PME) spectral intensity ratio was higher in early onset preeclampsia than in early normal pregnancy (p = 0.03 and p = 0.02). In normal pregnancy the PDE spectral intensity fraction and the PDE/PME spectral intensity ratio increased with increasing gestational age (p = 0.006 and p = 0.001). DISCUSSION: Since PDE and PME are related to cell membrane degradation and formation, respectively, our findings indicate increased cell degradation and maybe also decreased cell proliferation in early onset preeclampsia compared to early normal pregnancy, and with increasing gestational age in normal pregnancy. CONCLUSIONS: Our findings could be explained by increased apoptosis due to ischaemia in early onset preeclampsia and also increased apoptosis with increasing gestational age in normal pregnancy.

Placental perfusion in normal pregnancy and early and late preeclampsia: a magnetic resonance imaging study.

OBJECTIVE: Our primary aim was to investigate if women with early or late preeclampsia have different placental perfusion compared with normal pregnancies. A secondary aim was to investigate if placental perfusion changes with increasing gestational age in normal pregnancy. METHODS: The study population included thirteen women with preeclampsia (five with early and eight with late preeclampsia) and nineteen women with normal pregnancy (ten with early and nine with late pregnancy). Early was defined as <34 weeks and late as ≥ 34 weeks gestation. All women underwent a magnetic resonance imaging (MRI) examination including a diffusion weighted sequence at 1.5 T. The perfusion fraction was calculated. RESULTS: Women with early preeclampsia had a smaller placental perfusion fraction (p = 0.001) and women with late preeclampsia had a larger placental perfusion fraction (p = 0.011), compared to women with normal pregnancies at the corresponding gestational age. The placental perfusion fraction decreased with increasing gestational age in normal pregnancies (p = 0.001). CONCLUSION: Both early and late preeclampsia differ in placental perfusion from normal pregnant women. Observed differences are however in the opposite direction, suggesting differences in pathophysiology. Placental perfusion decreases with increasing gestational age in normal pregnancy.

The relationship between carotid intima-media thickness and global atherosclerosis.

BACKGROUND: The aim of this study was to investigate the relationship between (i) carotid intima-media thickness (CIMT) at baseline as well as (ii) change in CIMT over 5 years (ΔCIMT) and atherosclerotically induced luminal narrowing in non-coronary arterial territories assessed by whole-body magnetic resonance angiography (WBMRA). METHODS AND RESULTS: In subgroups of the Prospective Investigation of Vasculature in Uppsala Seniors (PIVUS) study, US measurements of CIMT in the common carotid arteries were analysed at 70 and 75 years and ΔCIMT was calculated (n = 272). WBMRA, assessing arterial stenosis in five different territories by which also a total atherosclerotic score (TAS) was calculated, was performed at 70 years (n = 306). RESULTS: Carotid intima-media thickness in the carotid artery at baseline was correlated with TAS (P = 0.0001) when adjusted to a set of traditional risk factors for atherosclerosis, as well as to stenosis in two of the different investigated territories (aorta and lower leg, P = 0.013 and P = 0.004), but there was no significant correlation between ΔCIMT and TAS (P = 0.41). CONCLUSIONS: In the present study, CIMT, but not ΔCIMT over 5 years, in the carotid artery was related to overall stenoses in the body, as assessed by WBMRA. These findings support CIMT as a general marker for atherosclerosis.

Asymmetric development of the hippocampal region is common: a fetal MR imaging study.

BACKGROUND AND PURPOSE: Hippocampal development is poorly understood. This study evaluated the normal development of the hippocampal region during the fetal period by using MR imaging. MATERIALS AND METHODS: MR images of 63 fetuses without intracranial pathology were reviewed independently by 2 radiologists with no knowledge of the fetal GA. Three MR images were performed postmortem and 60 in vivo. The progress of hippocampal inversion was analyzed in coronal sections, and the left and right sides of the hippocampal region were compared in every case. RESULTS: The fetuses in the postmortem examinations were at GWs 17-18 and in the in vivo examinations, at GWs 19-36. The hippocampal sulcus was open, bi- or unilaterally, in 39 fetuses. The oldest was at GW 32. The sulcus was closed at GW 21 at the earliest, unilaterally. In 26/63 fetuses (41%), the deepening or closure of the hippocampal sulcus or hippocampal inversion was asymmetric; in 23 fetuses, the right side developed faster. A shallow collateral sulcus was found earliest at GW 17. A deep collateral sulcus was visible earliest at GW 26 unilaterally, but in all fetuses from GW 31 onward, it was seen bilaterally. The orientation of the collateral sulcus was not related to the GA. CONCLUSIONS: There are wide individual temporal variations in the development and the inversion process of the hippocampal sulcus as well as in the formation of the collateral sulcus. Asymmetric development is common, and in most of the asymmetric cases, the right hippocampus develops faster.

Development of the hippocampal region demonstrated by fetal MRI. A preliminary report.

Coronal slices of three fetal MRIs performed post mortem and 37 performed in utero, all without intracranial pathology, was assessed. Progress of the hippocampal inversion was analyzed, the left and right sides were compared and occurrence of the collateral sulcus was revealed. The fetuses in the post mortem examinations were at gestation weeks (GW) 17-18 and in the in utero examinations at GW 19-35. The symmetric development of the hippocampal sulcus was revealed in 26 subjects and asymmetric in 14. The non-ovoid hippocampal formation could be evaluated at GW 24 at earliest and an ovoid hippocampus at GW 29. The collateral sulcus could be recognized at GW 17 in post mortem and at GW 22 in in utero examinations. From GW 29 onwards it was seen in all fetuses and it was symmetric in all but one case. Evaluation of the hippocampi is difficult on fetal MRI, especially in in utero examinations. The hippocampal development is not fulfilled at GW 21 as presumed. There is a wide temporal variation in the development of the hippocampal region, and the developmental process does not progress simultaneously in the right and left side of the same individual.

Visceral adipose tissue, adiponectin levels and insulin resistance are related to atherosclerosis as assessed by whole-body magnetic resonance angiography in an elderly population.

OBJECTIVE: The principal aim of this study was to determine whether the amount of visceral adipose tissue (VAT) is more related than subcutaneous adipose tissue (SAT) to atherosclerosis assessed by whole-body MRA (WBMRA). A further objective was to investigate whether traditional risk factors, inflammation, or adipokines could explain the hypothesized relationship between VAT and atherosclerosis. METHODS: Men and women aged 70 were recruited from the general population into the Prospective Investigation of The Vasculature in Uppsala Seniors (PIVUS) and 306 of them underwent WBMRA in a clinical 1.5-T scanner. The arterial tree was assessed for degree of stenosis or occlusion and a total atherosclerotic score (TAS) was established. Information on risk factors and BMI and on SAT and VAT, segmented on an axial MR scan was collected. Adiponectin, leptin, and high sensitive C-reactive protein (hsCRP) were measured in serum. HOMA index was used as a marker of insulin resistance. RESULTS: VAT was related to TAS independently of gender, total obesity (BMI), amount of SAT, hsCRP and also to the traditional risk factors included in the Framingham risk score (FRS) in an elderly population. Adiponectin or the HOMA insulin resistance, but not leptin or VAT, together with FRS was significantly related to TAS in a multiple censored regression model. CONCLUSION: Adiponectin attenuated the relationship between VAT and TAS, suggesting that adiponectin and insulin resistance is an important link between visceral adiposity and atherosclerosis.

Venous saturation slab causes overestimation of stenosis length in two-dimensional time-of-flight magnetic resonance angiography.

BACKGROUND: The use of downstream saturation slabs in two-dimensional time-of-flight magnetic resonance angiography (2D TOF MRA) of the arterial system eliminates signal from regions with countercurrent flow, as seen in veins, but possibly also beyond arterial stenoses because of flow turbulence. PURPOSE: To investigate the contribution of a downstream saturation slab to signal intensity (SI) loss beyond stenoses at 2D TOF MRA. MATERIAL AND METHODS: 2D TOF MRA was performed on a bifurcation phantom with a tight stenosis at 1.5T during pulsatile flow. Qualitative and quantitative evaluations of stenosis delineation were performed with different echo times (TE) (3.7 or 7.0 ms), spatial resolution (1 x 1 x 1 or 1 x 1 x 5 mm(3)), and with or without a downstream saturation slab. For reference, a high-resolution contrast-enhanced sequence without flow was obtained. RESULTS: The downstream saturation slab caused severe signal loss immediately distal to the stenosis, causing overestimation of stenosis length. This region corresponded with a region of poststenotic flow jet, where turbulence is expected. With increase in TE, there was some increased SI loss at the level of maximum stenosis. A lower spatial resolution resulted in overall poorer delineation of the stenosis. CONCLUSION: Using clinically relevant sequence parameters, the use of a downstream saturation slab at 2D TOF MRA was found to be a major contributor to signal loss in stenotic regions, which can result in an overestimation of stenosis length.

Effects of rosuvastatin on cardiovascular morphology and function in an ApoE-knockout mouse model of atherosclerosis.

This study investigated the effects of rosuvastatin on plaque progression and in vivo coronary artery function in apolipoprotein E-knockout (ApoE-KO) mice, using noninvasive high-resolution ultrasound techniques. Eight-week-old male ApoE-KO mice (n = 20) were fed a high-fat diet with or without rosuvastatin (10 micromol.kg(-1).day(-1)) for 16 wk. When compared with control, rosuvastatin reduced total cholesterol levels (P < 0.05) and caused significant retardation of lesion progression in the brachiocephalic artery, as visualized in vivo using an ultrasound biomicroscope (P < 0.05). Histological analysis confirmed the reduction of brachiocephalic atherosclerosis and also revealed an increase in collagen content in the statin-treated group (P < 0.05). Coronary volumetric flow was measured by simultaneous recording of Doppler velocity signals and left coronary artery morphology before and during adenosine infusion. The hyperemic flow in response to adenosine was significantly greater in left coronary artery following 16 wk of rosuvastatin treatment (P < 0.001), whereas the baseline flow was similar in both groups. In conclusion, rosuvastatin reduced brachiocephalic artery atherosclerotic plaques in ApoE-KO mice. Coronary artery function assessed using recently developed in vivo ultrasound-based protocols, also improved.

A total atherosclerotic score for whole-body MRA and its relation to traditional cardiovascular risk factors.

The aim of this study was to create a scoring system for whole-body magnetic resonance angiography (WBMRA) that allows estimation of atherosclerotic induced luminal narrowing, and determine whether the traditional cardiovascular (CV) risk factors included in the Framingham risk score (FRS) were related to this total atherosclerotic score (TAS) in an elderly population. A group of 306 subjects, aged 70, were recruited from the general population and underwent WBMRA in a 1.5-T scanner. Three-dimensional sequences were acquired after administration of one i.v. injection of 40 ml gadodiamide. The arterial tree was divided into five territories (carotid, aorta, renal, upper and lower leg) comprising 26 vessel segments, and assessed according to its degree of stenosis or occlusion. FRS correlated to TAS (r = 0.30, P < 0.0001), as well as to the atherosclerotic score for the five individual territories. Of the parameters included in the FRS, male gender (P < 0.0001), systolic blood pressure (P = 0.0002), cigarette pack-years (P = 0.0008) and HDL cholesterol (P = 0.008) contributed to the significance. A scoring system for WBMRA was created. The significant relation towards traditional CV risk factors indicates that the proposed scoring system could be of value for assessing atherosclerotically induced luminal narrowing.

Kinetic simulation model of protein secretion and accumulation in the cell microcapsules.

BACKGROUND: In cell therapy, microencapsulated cells secrete therapeutic protein, which is further released from the microcapsules. In principle, some secreted, but unreleased, protein may accumulate in the microcapsules. The kinetic simulation model was built to simulate the potential accumulation of the protein in the microcapsules. METHODS: The alginate microcapsules were cross-linked with divalent cations to encapsulate either flourescein isothiocyanate (FITC)-dextrans (molecular weights = 4.3, 10.5, 43 kDa) or retinal pigment epithelial cells (ARPE-19). The cells were genetically engineered to produce secreted alkaline phosphatase (SEAP). SEAP production from the cells was quantified with and without microcapsulation and, finally, the cells were killed with toxin to quantify the secreted but yet unreleased SEAP from the microcapsules. The empirical three-compartment kinetic model was constructed based on the release of FITC-dextrans of different molecular weights from the alginate microcapsules with different pore sizes. Protein secretion from the cells into the microcapsules was added to the model. The impact of the microcapsule wall permeability on the steady-state amounts of secreted protein in the microcapsules and in the hypothetical target compartment in the body was simulated. The simulations were compared to the experimental data from the microencapsulated SEAP secreting ARPE-19 cells. RESULTS: The model and the data show that substantial amounts (10-15 daily doses) of protein may accumulate in the microcapsules with poor wall permeability. At high permeability, the accumulation was insignificant. The pharmacokinetic simulations show that even a 1.5-fold increase in the wall permeability may result in a substantial peak in the drug amount in the target compartment, especially if the elimination rate of the protein is high. CONCLUSIONS: The kinetic simulation model for protein secretion from microcapsulated cells is a useful tool for the early kinetic prediction and risk assessment of cell therapy.

Ankle brachial index <0.9 underestimates the prevalence of peripheral artery occlusive disease assessed with whole-body magnetic resonance angiography in the elderly.

BACKGROUND: Whole-body magnetic resonance angiography (WBMRA) permits noninvasive vascular assessment, which can be utilized in epidemiological studies. PURPOSE: To assess the relation between a low ankle brachial index (ABI) and high-grade stenoses in the pelvic and leg arteries in the elderly. MATERIAL AND METHODS: WBMRA was performed in a population sample of 306 subjects aged 70 years. The arteries below the aortic bifurcation were graded after the most severe stenosis according to one of three grades: 0-49% stenosis, 50-99% stenosis, or occlusion. ABI was calculated for each side. RESULTS: There were assessable WBMRA and ABI examinations in 268 (right side), 265 (left side), and 258 cases (both sides). At least one > or =50% stenosis was found in 19% (right side), 23% (left side), and 28% (on at least one side) of the cases. The corresponding prevalences for ABI <0.9 were 4.5%, 4.2%, and 6.6%. An ABI cut-off value of 0.9 resulted in a sensitivity, specificity, and positive and negative predictive value of 20%, 99%, 83%, and 84% on the right side, and 15%, 99%, 82%, and 80% on the left side, respectively, for the presence of a > or =50% stenosis in the pelvic or leg arteries. CONCLUSION: An ABI <0.9 underestimates the prevalence of peripheral arterial occlusive disease in the general elderly population.

Three-dimensional time-of-flight (3D TOF) magnetic resonance angiography (MRA) and contrast-enhanced MRA of intracranial aneurysms treated with platinum coils.

BACKGROUND: Contrast-enhanced magnetic resonance angiography (CE-MRA) is less prone to flow-related signal intensity loss than three-dimensional time-of-flight (3D TOF) MRA and may therefore be more sensitive for detection of residual patency in platinum coil-treated intracranial aneurysms. PURPOSE: To compare MRA and CE-MRA in the follow-up of intracranial aneurysms treated with platinum coils. MATERIAL AND METHODS: CE-MRA and 3D TOF MRA (pre- and postcontrast injection) of the intracranial vasculature was performed at 1.5T in 38 patients (47 aneurysms) referred for DSA in the follow-up of coiled intracranial aneurysms. RESULTS: DSA showed aneurysm patency in 22/47 investigations. Patent aneurysm components were observed with CE-MRA in 18/22 cases, and with 3D TOF MRA in 21/22 cases. There was no significant difference in patent aneurysm component size between CE-MRA and 3D TOF MRA. In addition, CE-MRA showed six, 3D TOF MRA before contrast injection showed seven, and 3D TOF MRA after contrast injection showed eight cases with patent aneurysm components not observed on DSA. CONCLUSION: 3D TOF MRA was highly sensitive for detection of patent aneurysm components, and at least as sensitive as CE-MRA. Residual aneurysm patency seems to be better visualized with MRA than with DSA in some cases.