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Results for “Angiography”

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PubMed1994

MR imaging (including MR angiography) of abdominal aortic aneurysms: comparison with conventional angiography.

OBJECTIVE: The purpose of this report is to compare the results of MR imaging, including MR angiography, with the results of conventional angiography in the imaging of abdominal aortic aneurysms (AAA). SUBJECTS AND METHODS: Twenty seven nonconsecutive patients with known AAA underwent both MR imaging (including MR angiography) and conventional angiography preoperatively. MR imaging was done before angiography according to the following protocol in all patients: sagittal and coronal T1-weighted images of the abdomen, followed by axial MR angiograms obtained with a multiple overlapping thin-slab acquisition (MOTSA) three-dimensional time-of-flight (3D TOF) volume centered on the renal arteries. Last, coronal MR angiograms were obtained with a dynamic contrast-enhanced 3D TOF volume centered on the aorta. Conventional angiography was subsequently performed in all patients. Data from each study were collected prospectively and analyzed in a blinded manner. For the MR studies, all sequences were used to determine the extent of the AAA and the presence of iliac aneurysms; stenotic disease of the celiac, superior mesenteric, renal, and iliac arteries and the number and location of renal arteries were determined from the MR angiograms. For evaluation of the extent of the aneurysm, results from both techniques were compared with surgical results; otherwise MR angiography was compared with conventional angiography. Confidence intervals for sensitivity and specificity were calculated at the 95% level. The McNemar test was used for comparison of proportions. RESULTS: MR angiography had a sensitivity of 100% (4/4) and a specificity of 91% (21/23) for the four stenoses of the celiac artery that were greater than 50%. For detection of renal artery stenoses of greater than 50%, present in nine arteries, the sensitivity was 89% (8/9) and specificity was 98% (49/50). MR angiography showed 100% (54/54) of all main renal arteries and 78% (7/9) of all accessory renal arteries seen on conventional angiograms. The proximal extent of the aneurysm was correctly predicted on the basis of MR findings in 100% (26/26) of patients with surgical correlation, compared with 92% (24/26) when conventional angiograms were used. This difference was not statistically significant (p > .1). MR imaging had a sensitivity of 100% (19/19) for detection of isolated aneurysms of the common iliac artery, and MR angiography had a 100% sensitivity (5/5) and specificity (103/103) for detection of stenosis greater than 50% in the common and external iliac arteries. One circumaortic left renal vein was visualized on MR images. CONCLUSION: These results suggest that MR angiography may be a useful noninvasive method for determining the presence of coexistent celiac, superior mesenteric, renal, and iliac atherosclerotic disease in patients with AAA.

Aged↗

PubMed1991

Evaluation of the extracranial carotid arteries: correlation of magnetic resonance angiography, duplex ultrasonography, and conventional angiography.

We compared duplex scanning, "bright blood" and "black blood" magnetic resonance angiography, and conventional angiography for evaluation of the extracranial carotid arteries. All three methods were applied to 39 vessels in 20 patients. Duplex scanning was inaccurate when compared to conventional angiography in six instances. In three instances the degree of stenosis was overgraded by the scanner, and in three cases the stenosis was undergraded. Magnetic resonance angiography was inaccurate when compared to conventional angiography in three instances. In all cases magnetic resonance angiography overgraded the degree of stenosis. By use of a greater than 70% stenosis as a positive study, the sensitivity of magnetic resonance angiography was 100% and the specificity 92%. With use of the same criteria, the sensitivity of duplex scanning was 86%, and specificity was 84%. In those evaluations where the results of the magnetic resonance angiography and duplex scanning were in agreement, the correlation with conventional angiography was 100%. We conclude that magnetic resonance angiography is an alternative means to duplex scanning for noninvasive carotid imaging. A combination of bright and black blood magnetic resonance angiography is precise in delineating lesions of the extracranial carotid artery and may ultimately eliminate the need for conventional angiography in the evaluation of carotid stenosis.

Angiography, Digital Subtraction↗

PubMed2003

[Surgical management of posterior communicating artery aneurysms based on computed tomographic angiography with three-dimensional reconstruction and without preoperative angiography].

OBJECTIVE: To demonstrate the usefulness of three-dimensional computed tomographic angiography (CT-3D-angiography) in the microsurgical management of aneurysms of the posterior communicating artery (PComA). MATERIALS AND METHODS: A series of 27 patients with aneurysms of the PComA diagnosed by means of CT-3D-angiography and without preoperative angiography (group A) were compared with a series of 34 cases diagnosed by cerebral angiography. The findings of the CT-3D-angiography, angiography, microsurgical exploration and clinical data were evaluated. RESULTS: A total of 75 aneurysms were diagnosed preoperatively in 66 patients and 3 additional lesions were found postoperatively in group A. The sensitivity of the CT-3D-angiography was 91.7% for diagnosis of any aneurysm with an specifity of 100%, being the snsibility of angiography a 100% and its specifity 94.9%. Mortality rate was 4.5% without differences between groups regarding clinical results or complications. Both the preoperative timing and hospitalization time were shorter in group A. CONCLUSION: The study of patients with acute subarachnoid hemorrhage with CT-3D-angiography allows a reliable diagnosis of PComA aneurysms. Moreover, provides usefull information for the microsurgical clipping. When compared with angiography in the diagnosis of PComA aneurysms, CT-3D-angiography allows to improve some health indicators with similar clinical results and complications.

Humans↗

PubMed2002

Coarctation of the aorta: comparison of aortic dimensions between conventional MR imaging, 3D MR angiography, and conventional angiography.

Magnetic resonance angiography is increasingly used as a non-invasive method in the evaluation of coarctation of the aorta. The aim of this study was to compare aortic dimensions calculated by MR angiography and those obtained by more conventional MR sequences and conventional angiography. Twenty-six consecutive patients with coarctation underwent three-dimensional MR angiography. Two independent observers retrospectively evaluated three aortic segments, site of coarctation, presence of aneurysm and existence of collateral circulation. Three aortic segments were also compared with those obtained on classical MR sequences and conventional angiography. The MR angiography was successfully performed in all showing 1 aneurysm and collateral circulation in 8 patients. Almost perfect intraobserver ( r(2)>0.91) and excellent interobserver ( r(2)>0.80) reliabilities were obtained for each aortic segment no matter which MR sequence was employed. Similarly, mainly excellent ( r(2)>0.80) concordance analysis was observed between MR angiography measurements and those calculated by either spin-echo/gradient-echo sequences or conventional angiography. This study demonstrates that MR angiography is a fast, accurate and reproducible method in the evaluation of coarctation of the aorta. It provides excellent anatomic information and reliably detects collateral vessels. Magnetic resonance angiography could probably replace the conventional angiography and will provide an additional diagnostic value in combination with turbo spin-echo sequence.

Adolescent↗

PubMed2004

[Grading of carotid artery stenosis using high resolution dynamic magnetic resonance angiography in comparison to intraarterial digital subtraction angiography. Are stenoses over 70% reliably detectable?].

PURPOSES: Evaluation of high resolution dynamic magnetic resonance angiography (ceMRA) in detection and graduation of carotid artery stenosis in comparison to intraarterial digital subtraction angiography. MATERIALS AND METHODS: Magnetic resonance angiography and intraarterial digital subtraction angiography was performed in 65 patients with suspected carotid artery stenosis by ultrasound examination. Detection and graduation of carotid artery stenosis by magnetic resonance angiography were compared to those of intraarterial digital subtraction angiography after stenosis grading according to NASCET criteria. RESULTS: All magnetic resonance angiographies were of excellent quality, with 46 stenoses type I and II and 12 stenoses type III NASCET correctly identified and classified by magnetic resonance angiography. Overestimation was found in 4 cases and underestimation in 2 cases. Both modalities detected 13 occlusions. Sensitivity and specificity of ceMRA were 92%. The positive predictive value was 86% and the negative predictive value 96%. CONCLUSION: High resolution dynamic magnetic resonance angiography is suitable in detecting and classifying carotid artery stenoses over 70% with high sensitivity and specificity in comparison to intraarterial digital subtraction angiography. Intraarterial digital subtraction angiography should only be performed in critical cases.

Aged↗

PubMed1997

Preliminary results on the management of unruptured intracranial aneurysms with magnetic resonance angiography and computed tomographic angiography.

OBJECTIVE: The goal was to assess the capability of magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) to replace catheter angiography in the evaluation of unruptured intracranial aneurysms. METHODS: A prospective evaluation of a 1-year period included all patients suspected of harboring unruptured intracranial aneurysms at a single institution. All patients underwent magnetic resonance imaging, MRA, and CTA, for comparison with intraoperative findings or results from catheter angiography. Both MRA and CTA now provide submillimeter resolution of vascular structures, with accurate detection of intracranial aneurysms of a diameter greater than or equal to 3 mm. This resolution calls into question the universal need for catheter angiography in the care of patients with suspected intracranial aneurysms. When the catheter angiography can be avoided, radiological costs can be reduced by as much as two-thirds while eliminating the risk of arterial injury and stroke. RESULTS: Excellent visualization of the intracranial vasculature was provided by both MRA and CTA. No vascular lesion was detected at surgery or by formal angiography that was not visualized by noninvasive angiographic techniques. The three-dimensional anatomy of the aneurysm complex (unavailable with catheter angiography) was well depicted by both MRA and CTA. CTA was unique in its capacity to display the relationship of vascular structures to bone, information that is invaluable for planning operative strategies for lesions such as carotidophthalmic artery aneurysms. Additionally, acquisition of CTA images was very rapid, with a scanning time of less than 1 minute. Both MRA and CTA allowed for retrospective manipulation of data into an infinite number of views, including views that paralleled those encountered through the operative microscope. Additionally, both MRA and CTA can depict the internal anatomy of aneurysms, an ability not possessed by intra-arterial angiography. This ability alerts the surgeon to possible intraoperative risks, such as plaque in the lumen of an aneurysm or calcium within the walls of the arteries. CONCLUSION: Both MRA and CTA provide several advantages over digital subtraction angiography, in addition to reduced costs and avoidance of arterial injury and stroke. These include retrospective manipulation of data in a 360-degree format, visualization of the internal anatomy of arteries and aneurysms, three-dimensional depiction of anatomy, and rapid data acquisition. Preliminary data and a review of the literature suggest that MRA, when used in concert with CTA, can replace catheter angiography in the assessment of select patients harboring unruptured intracranial aneurysms. Although no firm conclusions or generalizations can be drawn from this small cohort of patients, it is hoped that this report will stimulate interest and further study at other institutions.

Aged↗

PubMed2006

Comparison of intraarterial MR angiography at 3.0 T with X-ray digital subtraction angiography for detection of renal artery stenosis in swine.

PURPOSE: To compare the accuracy of catheter-directed intraarterial (IA) magnetic resonance (MR) angiography at 3.0 T with that of x-ray digital subtraction angiography (DSA) for the measurement of renal artery stenosis (RAS) in swine. MATERIALS AND METHODS: Unilateral hemodynamically significant RAS (>50%) was induced surgically in six pigs with use of reverse cable ties. One to two weeks after surgery, each pig underwent x-ray DSA and MR angiography before and after percutaneous transluminal balloon angioplasty (PTA). X-ray DSA was performed before and after PTA of RAS by injection of iodinated contrast agent through a 5-F multiple-side hole angiographic catheter placed in the abdominal aorta under fluoroscopic guidance. MR angiography of RAS was performed before and after PTA of RAS on a 3.0-T clinical MR imager with use of gadolinium-based contrast agent. MR angiography and DSA images were analyzed with the full width at half maximum method. Percent stenosis measurements between x-ray DSA and MR angiography were compared with a paired t test and were correlated with linear regression and Bland Altman analysis (alpha = 0.05). RESULTS: Six cases of RAS were induced and imaged successfully with DSA and MR angiography techniques before and after PTA. On x-ray DSA, median stenoses was 64% (95% CI 57%-80%) before PTA and 20% (95% CI 5%-32%) after PTA. Corresponding MR angiography median stenosis measurement was 69% (95% CI 58%-80%) before PTA and 26% (95% CI 16%-36%) after PTA. A paired t test comparison did not show a difference between DSA and MR angiography (P = .16). RAS measurements on MR angiography correlated closely (P < .01) with DSA measurements (r(2) = 0.92). CONCLUSION: In swine, the accuracy of catheter-directed IA MR angiography with use of a clinical 3.0-T MR imaging unit for the measurement of RAS was similar to that of conventional x-ray DSA.

Angiography, Digital Subtraction↗

PubMed1999

Renal artery stenosis: evaluation with conventional angiography versus gadolinium-enhanced MR angiography.

PURPOSE: To evaluate the interobserver and intermodality variability of conventional angiography and gadolinium-enhanced magnetic resonance (MR) angiography in the assessment of renal artery stenosis. MATERIALS AND METHODS: Fifty-four patients underwent conventional angiography and gadolinium-enhanced three-dimensional gradient-echo MR angiography. Three angiographers blinded to each other's interpretations and the MR angiographic findings assessed the conventional angiograms for renal artery stenosis. Similarly, three blinded MR imagers evaluated the MR angiograms. RESULTS: Interobserver variability for the degree of renal artery stenosis in the 107 kidneys evaluated was not significantly different between the two modalities. The mean SD of the degree of stenosis was 6.9% at MR angiography versus 7.5% at conventional angiography (alpha < or = .05, P > .05). In 70 kidneys (65%), the average degree of stenosis reported by the readers for the two modalities differed by 10% or less. In 22 cases (21%), the degree of stenosis was overestimated with MR angiography by more than 10% relative to the results of conventional angiography. In 15 cases (14%), the degree of stenosis was underestimated with MR angiography by more than 10%. CONCLUSION: Gadolinium-enhanced MR angiography permits evaluation of renal artery stenosis with an interobserver variability comparable with that of conventional angiography.

Angiography↗

PubMed1996

Preoperative staging of cancer of the pancreas: value of MR angiography versus conventional angiography in detecting portal venous invasion.

OBJECTIVE: The purpose of this study was to compare contrast-enhanced MR angiography with conventional catheter angiography for detecting portal venous invasion in the preoperative staging of pancreatic cancer, using the surgical confirmation of vascular involvement as the standard of truth. SUBJECTS AND METHODS: MR and conventional angiography were performed in 20 patients with pancreatic carcinoma, with surgical confirmation in all cases. MR angiography was performed at 1.5 T, with coronal (2.9 mm) and axial (6.0 mm) contrast-enhanced breath-hold two-dimensional time-of-flight imaging. Data from each imaging technique were collected prospectively and analyzed in a blinded fashion by expert vascular radiologists. Vascular involvement in each patient and in each vessel (main portal vein, confluence, splenic vein, and superior mesenteric vein) determined whether the tumor was resectable (normal, abutment) or nonresectable (encased, occluded). Surgical confirmation of the vascular involvement of the portal venous structures was used as the standard of truth in all patients. RESULTS: Among the 20 patients, 11 tumors were surgically resectable and seven were nonresectable with performance of a palliative bypass. MR angiography and conventional angiography had an overall concordance in 65% of patients (13/20; seven resectable, four nonresectable, two false-negatives) on the basis of the vascular status in each patient of the portal venous structures and in 84% (47/56) of the individual vessels surgically confirmed. MR angiography correctly identified 11 of 11 resectable patients and five of nine nonresectable patients, with four false-negative cases. Conventional angiography correctly identified seven of 11 resectable patients and six of nine nonresectable patients, with three false-negative cases and four false-positive cases. CONCLUSION: The lack of false-positives by MR angiography suggests that MR imaging may provide a noninvasive screen for nonresectability on the basis of vascular involvement, with no patients with potentially resectable tumors being denied surgery by MR angiography in this cohort. However, the presence of false-negatives using MR angiography indicates the procedure would still not fully eliminate unnecessary laparotomies.

Aged↗

PubMed2002

Peripheral vascular occlusive disease: evaluation with contrast-enhanced moving-bed MR angiography versus digital subtraction angiography in 106 patients.

OBJECTIVE: The purpose of our study was to compare contrast-enhanced moving-bed MR angiography and digital subtraction angiography in the evaluation of peripheral vascular occlusive disease. MATERIALS AND METHODS: This retrospective report includes 106 patients (45 women, 61 men) with known or suspected peripheral vascular occlusive disease who underwent MR angiography and intraarterial digital subtraction angiography of the peripheral arteries. MR angiography was performed on a 1.0-T unit using a moving-bed technique. Every leg was divided into 14 vascular segments, and severity of disease was scored in four categories. Digital subtraction angiography was the standard of reference. RESULTS: In the 106 patients, 2378 vessel segments were evaluated with both imaging modalities. In 2156 segments, MR angiography and digital subtraction angiography were concordant for stenosis classification, in 188 segments the two modalities differed in one category, and in 24 segments they differed in two categories. MR angiography achieved sensitivity and specificity of 96.7% and 95.8%, respectively, for differentiating nonsignificant from hemodynamically significant stenosis (kappa = 0.91). CONCLUSION: This study indicates that MR angiography is an accurate imaging modality in clinical practice. Our data support the concept that MR angiography can modify the diagnosis of suspected peripheral vascular occlusive disease.

Adult↗

PubMed2004

Intracranial dural arteriovenous fistulas: evaluation with combined 3D time-of-flight MR angiography and MR digital subtraction angiography.

OBJECTIVE: The purpose of this study was to compare the diagnostic utility of 3D time-of-flight (TOF) MR angiography and MR digital subtraction angiography in patients with angiographically proven moderate- to high-flow intracranial dural arteriovenous fistula. MATERIALS AND METHODS: Two neuroradiologists, unaware of patients' histories and angiographic findings, retrospectively reviewed 17 MR angiograms with 3D TOF MR angiography and MR digital subtraction angiography in 15 patients with dural arteriovenous fistula and also reviewed 35 MR angiograms in control patients without findings of dural arteriovenous fistula on angiography. Disagreements were resolved by consensus. RESULTS: In patients with dural arteriovenous fistula, source images of 3D TOF MR angiography showed two abnormal findings: multiple high-intensity curvilinear or nodular structures adjacent to the sinus wall and high-intensity areas in the venous sinus. Findings of multiple high-intensity structures adjacent to the sinus wall were observed in all cases of dural arteriovenous fistula. Findings of high-intensity areas in the venous sinus were observed in 13 of 17 cases of dural arteriovenous fistula. Findings of multiple high-intensity structures adjacent to the sinus wall were not observed in any control subjects. Findings of high-intensity areas within the venous sinus were observed in five of 35 control subjects. Findings of MR digital subtraction angiography showed early filling of the venous sinus, suggestive of dural arteriovenous fistula, in 13 of 15 patients with dural arteriovenous fistula. Sensitivity and specificity of multiple high-intensity structures adjacent to the sinus wall, high-intensity areas in the venous sinus, and early filling of the venous sinus were 100% and 100%, 76% and 86%, and 87% and 100%, respectively. Although 3D TOF MR angiography failed to show the findings of retrograde cortical venous drainage and venous sinus occlusion, MR digital subtraction angiography clearly showed both findings in all five subjects. CONCLUSION: A protocol including both 3D TOF MR angiography (source images) and MR digital subtraction angiography allowed the diagnosis of moderate- to high-flow dural arteriovenous fistula. In addition, cortical venous drainage was reliably noted in a small subset of patients.

Adult↗

PubMedDate not supplied

3D-CT angiography of cerebral aneurysms with spiral scanning: comparison with 3D-time-of-flight MR angiography.

To compare the clinical value of three-dimensional (3D)-CT angiography using spiral scanning and 3D-time-of-flight (TOF) MR angiography in the diagnosis of cerebral aneurysms, the results of these studies were compared in 12 patients with a total of 17 aneurysms. In seven of the 17 aneurysms, anatomic details were visualized better by 3D-CT angiography than by MR angiography. Both studies demonstrated five aneurysms equally well. MR angiography delineated three aneurysms better than 3D-CT angiography. Both studies failed to demonstrate two very small aneurysms. In 3D-CT angiography, aneurysms were viewed from many view angles, allowing the assessment of the spatial relationship between an aneurysm and the surrounding vascular and bone structures. Considering the use of contrast material and irradiation, 3D-CT angiography is of value in delineating aneurysms which are equivocal on MR angiography. In addition, 3D-CT angiography is a potential preoperative adjunct to conventional angiography.

Aged↗

PubMed2006

Multi-section CT angiography compared with digital subtraction angiography in diagnosing major arterial hemorrhage in inflammatory pancreatic disease.

PURPOSE: Major arterial hemorrhage is an uncommon but serious complication of pancreatitis with high morbidity and mortality. Digital subtraction angiography (DSA) has long been the gold standard for the detection of a visceral artery pseudoaneurysm or for the site of active bleeding in patients with pancreatitis. Multi-section CT angiography is a minimally invasive technique which can provide high-resolution and high-contrast images of the arterial lumen and wall, with a much lower risk of complication and morbidity compared to DSA. The aim of this study was to determine the accuracy of multi-section CT angiography for the diagnosis of arterial complications of inflammatory pancreatitic disease. MATERIALS AND METHODS: A retrospective analysis of all patients undergoing visceral angiography for major bleeding as a complication of pancreatitis between 1998 and 2004 was performed. Twenty-nine studies in 25 patients (20 males, 5 females) with a mean age of 50.9 years (range 11-67 years) were identified where multi-section CT angiography was performed in the 24 h preceding the digital subtraction angiogram. RESULTS: Digital subtraction angiography detected a pseudoaneurysm or contrast extravasation in 19 studies and no bleeding was demonstrated in 9 studies. CT angiography correctly identified the site and type of bleeding in 18 of the 19 positive studies. CT angiography detected extravasation of contrast in one study that was not demonstrated on digital subtraction angiography. The sensitivity and specificity for multi-section CT angiography for the detection of major arterial bleeding on a background of pancreatitis were 0.947 and 0.900, respectively. CONCLUSION: Multi-section CT angiography is a sensitive and accurate technique for the detection of major arterial hemorrhage in inflammatory pancreatic disease and should be considered as the first investigation in the management of these patients.

Adolescent↗

PubMedDate not supplied

Can multi-detector computed tomographic angiography replace conventional angiography prior to lower extremity arterial reconstruction?

UNLABELLED: Computed tomographic (CT) angiography has become a valuable diagnostic technique prior to lower extremity arterial reconstruction. The purpose of this study is to evaluate its accuracy, compared to conventional angiography for planning lower limb revascularization procedures. PATIENTS AND METHODS: A prospective study was performed on all patients who underwent lower extremity arterial reconstruction procedures and had both CT angiography and conventional angiography between October 2003 and November 2005. We compared both modalities of angiography to intra-operative findings and whether a change in operative procedure would have resulted. The time for performance of both techniques and their complications were also reported. RESULTS: Sixty nine patients were included in this study. Discrepancies between intra-operative findings and CT angiography were noted in four (6%) cases while there was none with conventional angiography (p = 0.127). Disagreements between intra-operative findings and CT angiography have lead to a different procedure in three (4.5%) cases and all were infra-inguinal. The time for performance of CT angiography was significantly shorter than that for conventional angiography (2.5 +/- 0.3 minutes vs 37.5 +/- 5.2, p = 0.006). CONCLUSION: For arterial reconstructive procedures CT angiography provides a less invasive and accurate imaging with short examination time. It can be used as a primary imaging modality in evaluation of lower limb ischemia.

Angiography↗

PubMed1992

Comparison of magnetic resonance angiography, conventional angiography, and duplex scanning.

BACKGROUND AND PURPOSE: To determine the accuracy of magnetic resonance angiography in assessing patients with cerebrovascular disease, we performed a study comparing the results of conventional cerebral angiography, duplex scanning, and magnetic resonance angiography. METHODS: From 42 patients, a total of 25 carotid arteries were evaluated by all three techniques. The studies were independently read and sorted into five categories according to the degree of stenosis: 0-15%, normal; 16-49%, mild; 50-79%, moderate; 80-99%, severe; and totally occluded. RESULTS: Magnetic resonance angiography correlated exactly with conventional angiography in 39 arteries (52%); duplex scanning correlated with conventional angiography in 49 cases (65%). Compared with conventional angiography, both magnetic resonance angiography and duplex scanning tended to overread the degree of stenosis. The most critical errors associated with magnetic resonance angiography were three readings of total occlusion in vessels found to be patent on conventional angiograms. CONCLUSIONS: Although magnetic resonance angiography offers great hope of providing high-quality imaging of the carotid artery with no risk and at less cost, data from this study suggest that misreading the degree of stenosis, or misinterpreting a stenosis for an occlusion, could lead to errors in clinical decisions. Guidelines for use of magnetic resonance angiography in a clinical setting are offered.

Adult↗

PubMed1994

Prospective evaluation of extracranial carotid stenosis: MR angiography with maximum-intensity projections and multiplanar reformation compared with conventional angiography.

OBJECTIVE: The purpose of this prospective study was to compare MR angiography of the carotid artery from the aortic arch through the circle of Willis using maximum-intensity projection (MIP) and multiplanar reformation (MPR) images with intraarterial angiography in the depiction of extracranial carotid atherosclerosis. SUBJECTS AND METHODS: The carotid arteries in 20 patients were studied with MR and intraarterial angiography. MR angiography included two-dimensional (2D) time-of-flight (TOF) sequences from the aortic arch through the skull base and three-dimensional (3D) TOF sequences centered at the carotid bifurcation and multiple overlapping thin slab acquisition (MOTSA) from the skull base to above the circle of Willis. Targeted MIP images of the 2D and 3D TOF MR angiograms through each carotid bifurcation were obtained. Last, MPR images of the 3D TOF MR angiograms at the obliquity that showed the greatest stenosis were obtained. All studies were reviewed in a double-blinded fashion by two neuroradiologists. Caliper measurements of MR angiograms and intraarterial angiograms were made by using North American Symptomatic Carotid Endarterectomy Trial criteria. Global MIPs of the aortic arch and common carotid arteries from the 2D TOF MR angiograms and targeted MIPs of the intracranial carotid arteries from the MOTSA MR angiograms were compared with the intraarterial angiogram and graded as normal, mild, moderate, severely stenotic, or occluded. RESULTS: MPR of the 3D TOF MR angiograms was highly correlated with intraarterial angiograms for both observers 1 and 2 (0.94/p < .001, 0.96/p < .001 [Pearson correlation/p value]). No statistically significant difference between 3D TOF MPR and intraarterial angiography was seen with a paired t-test. With an alpha = 0.05 (5% probability of type 1 error), the power to detect a difference as small as +/- 5% stenosis between 3D TOF MPR and intraarterial angiogram was 80% for observer 1 and 90% for observer 2. Although both MIPs of the 2D and 3D TOF MR angiograms showed high Pearson correlation coefficients (0.83, 0.90) with intraarterial angiography, the paired t-test revealed a statistically significant difference in the estimation of carotid stenosis. Both observers thought the global MIPs of the 2D TOF MR angiogram allowed good to excellent visualization of the common carotid arteries. The aortic arch was seen in 70% of patients; most of the missed cases occurred early in our experience, when the 2D axial images were not placed sufficiently inferior to include the arch. No stenosis of the great vessel origins was seen in this study. All four stenoses of the intracranial internal carotid artery identified with intraarterial angiography were seen with the MOTSA MR angiogram but with a tendency to overestimate stenosis. Only one carotid siphon was thought to show severe stenosis on the MR angiogram. Intraarterial angiography showed a 50% stenosis. CONCLUSION: It is possible to image the entire carotid artery from the aortic arch through the circle of Willis with MR angiography in a clinically acceptable time. MPR of the 3D TOF MR angiogram reliably shows the percentage of carotid stenosis with no statistically significant difference compared with intraarterial angiography. The role of MR angiography in showing lesions in the circle of Willis or the aortic arch is promising, but the limited number of tandem lesions in this study makes it difficult to draw any conclusions.

Aged↗

PubMed2003

Multidetector CT angiography of the aortoiliac system and lower extremities: a prospective comparison with digital subtraction angiography.

OBJECTIVE: Our objective was to determine whether multidetector CT (MDCT) angiography is an accurate and reliable method of revealing atheroocclusive disease of the aortoiliac system and the lower extremities compared with digital subtraction angiography (DSA). SUBJECTS AND METHODS: Forty-one patients with ischemic legs underwent both MDCT angiography and DSA of the aortoiliac system and the legs. The arterial supply of the legs was divided into 35 segments. Three independent observers rated each segment according to the maximal degree of arterial stenosis. Consensus interpretation was used to calculate the sensitivity and specificity of MDCT angiography in showing arterial occlusions and stenoses of at least 75%. Intertechnique agreement was measured for each anatomic segment, and interobserver agreement was calculated for both techniques. Agreement was quantified using the kappa statistic. RESULTS: The sensitivity and specificity of MDCT angiography for depicting arterial occlusions and stenoses of at least 75% were 88.6% and 97.7%, and 92.2% and 96.8%, respectively. Substantial intertechnique agreement (kappa > 0.4) was present in 102 (97.1%) of 105 arterial segments. Substantial interobserver agreement was present in 104 (99.0%) of 105 comparisons for both MDCT angiography and DSA with an average kappa value of 0.84 for CT and 0.78 for DSA. MDCT angiography showed more patent segments than DSA (1192 vs 1091). All nine segments seen on DSA and not seen on MDCT angiography were in the calves. Of 110 segments seen on MDCT angiography and not seen on DSA, 100 (90.9%) were in the calves. CONCLUSION: MDCT angiography was accurate in showing arterial atheroocclusive disease with reliability similar to DSA. MDCT angiography showed more vascular segments than DSA, particularly within calf vessels.

Adult↗

PubMed2003

Aortoiliac and renal arteries: prospective intraindividual comparison of contrast-enhanced three-dimensional MR angiography and multi-detector row CT angiography.

PURPOSE: To compare contrast material-enhanced three-dimensional (3D) magnetic resonance (MR) angiography and multi-detector row computed tomographic (CT) angiography in the same patients for assessment of the aortoiliac and renal arteries, with digital subtraction angiography (DSA) as the standard of reference. MATERIALS AND METHODS: DSA, 3D MR angiography, and multi-detector row CT angiography were performed in 46 consecutive patients. A total of 769 arterial segments were analyzed for arterial stenosis by using a four-point grading system. Aneurysmal changes were noted. The time required for performing 3D reconstructions and image analysis of both MR and CT data sets was measured. Patient acceptance for each modality was assessed with a visual analogue scale. Statistical analysis of data was performed. RESULTS: Sensitivity of MR angiography for detection of hemodynamically significant arterial stenosis was 92% for reader 1 and 93% for reader 2, and specificity was 100% and 99%, respectively. Sensitivity of CT angiography was 91% for reader 1 and 92% for reader 2, and specificity was 99% and 99%, respectively. Differences between the two modalities were not significant. Interobserver and intermodality agreement was excellent (kappa = 0.88-0.90). The time for performance of 3D reconstruction and image analysis of CT data sets was significantly longer than that for MR data sets (P <.001). Patient acceptance was best for CT angiography (P =.016). CONCLUSION: There is no statistically significant difference between 3D MR angiography and multi-detector row CT angiography in the detection of hemodynamically significant arterial stenosis of the aortoiliac and renal arteries.

Aged↗