Magnetic Resonance Angiography For Detection Research Articles

Magnetic resonance angiography in assessment of anomalies of anterior cerebral artery in adults.

Anomalies of anterior cerebral artery (ACA) include aplasia, hypoplasia and variations in number. Magnetic resonance angiography (MRA) is a non-invasive diagnostic technique for assessment of anomalies of cerebral arteries. The aim of the study was to determine the role of MRA in detection of variants of ACA in adults. This study is an observational retrospective study. This study included forty-nine adult cases (28 males and 21 females), mean age 48±12.9 SD with anomalies of ACA in MRA. Magnetic resonance imaging of the brain and MRA were done to all patients. Cerebral MRA and magnetic resonance images were evaluated for frequency and distribution of variants of anterior cerebral arteries, associated aneurysms and infarctions. Odds ratios (ORs) and relative risk were calculated to determine risk of occurrence of cerebral infarctions in patients with anomalies of ACA. Hypoplasia of ACA was the commonest anomaly of ACA (51% of cases). Risk of occurrence of cerebral infarctions was higher in cases with azygos variant (OR, 3.3; P=0.35) than in those with hypoplastic ACA (OR, 2; P=0.58). MRA was highly reliable in identification of different variants of ACA and concomitant vascular changes.

Time-of-flight magnetic resonance angiography for detection of postoperative recurrence in patients with chronic subdural hematoma.

Chronic subdural hematoma (CSDH) is associated with postoperative recurrence. Although various factors are involved in postoperative recurrence of CSDH, blood flow, especially in the middle meningeal artery (MMA), is considered to play an important role. We investigated whether the degree of signal intensity (SI) of the MMA on time-of-flight magnetic resonance angiography (TOF MRA) and various clinical factors are involved in recurrence of CSDH. The maximum SI of both MMAs was measured on TOF MRA images within 1month before or after the initial surgery. In total, 185 patients (20 with and 165 without recurrence of CSDH) were included in the analysis. The SI ratio and dementia were significant predictors of recurrence of CSDH (SI ratio: odds ratio [95% confidence interval (CI)] = 1.71 [1.32, 2.22], p < 0.0001; dementia: odds ratio [95% CI] = 7.41 [1.83, 30.1], p = 0.005). The estimated regression coefficients in the final model were 6.14 for the SI ratio and 1.28 for dementia. The risk score was derived according to these regression coefficients as follows: score = 5 × SI ratio + 1 (dementia: yes). With a score of 5, the predicted probability of recurrence was 2% [95% CI 0.7, 5.7], whereas with scores of 8 and 10, the probability was 43.3% [27.0, 61.1] and 89.5% [65.7, 97.5], respectively, which increased the risk of recurrence. Patients with an increased SI ratio of the affected MMA on TOF MRA who underwent surgery for CSDH were significantly more likely to experience recurrence.

Comparison of compressed sensing and conventional coronary magnetic resonance angiography for detection of coronary artery stenosis

PurposeThis study aimed to compare the efficacy of compressed sensing (CS) and conventional coronary magnetic resonance angiography (CMRA) in detecting coronary artery stenosis. MethodTwenty-eight patients underwent 3 T contrast-enhanced CS and conventional CMRA; for late gadolinium enhancement (LGE) imaging, 0.1 mmol/kg gadolinium medium was infused. CS CMRA was scanned within the LGE waiting time. After the LGE image acquisition, conventional CMRA was performed. The diagnostic performance of both CMRA for the detection of significant stenosis was evaluated using coronary angiography as a reference. The analysis was conducted to examine the three main coronary artery vessels: left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA). These arteries were subdivided into 8 segments (LAD; main, proximal, and middle, LCX; proximal and distal, RCA; proximal, middle, and distal). Of these, hypoplastic segments and vessels after coronary stent implantation were excluded. The acquisition time of CS CMRA was compared with that of conventional CMRA. ResultsThe coronary arteries were evaluated in 197 segments. The sensitivity, specificity, and accuracy of CS CMRA in detecting significant stenosis were 85.2 %, 82.5 %, and 83.2 %, respectively, on a per-segment basis. Those of conventional CMRA were 85.2 %, 86.7 %, and 86.3 %, respectively. The acquisition time was 207 s (range, 144–258 s) for CS and 975 s (range, 787–1226s) for conventional CMRA (p < 0.001). ConclusionsSimilar to conventional CMRA, CS CMRA has shown potential for the detection of significant coronary artery stenosis.

The usefulness of Time-of-Flight MR angiography in detection of intraplaque hemorrhage in patients with acute ischemic stroke with symptomatic carotid stenosis.

ObjectiveCarotid intraplaque hemorrhage (IPH) is a well-known risk indicator of thromboembolism, but it is not easy to rapidly detect IPH in acute symptomatic carotid disease. The aim of this study was to assess the utility of time-of-flight (TOF) magnetic resonance angiography (MRA) in the detection of IPH and evaluate the degree of stenosis and stroke patterns in patients with acute symptomatic carotid disease.MethodsWe retrospectively identified consecutive patients with acute symptomatic carotid disease who were admitted within 12 h after stroke onset. Fifty-nine patients underwent TOF MRA at admission and were categorized according to the presence or absence of intraplaque high signal intensity (HSI). The severity of carotid stenosis and diffusion-weighted magnetic resonance imaging lesion patterns were evaluated.ResultsIntraplaque HSI was detected in 28.8% of the enrolled patients (17/59). Mild-to-moderate symptomatic carotid stenosis was more frequent in the intraplaque HSI-positive group (70.6%) than in the intraplaque HSI-negative group (42.8%) (p = 0.015). The patients with intraplaque HSI more frequently exhibited a disseminated small infarction pattern (76.5% in the intraplaque HSI-positive group, 47.6% in the -negative group), and did not exhibit a border-zone infarction pattern (0% in the positive group, 16.7% in the negative group).ConclusionsTOF MRA may be a useful noninvasive and rapid tool to detect IPH in patients with acute symptomatic carotid disease. IPH was common in those with a lower degree of carotid stenosis and manifested as a disseminated small infarction pattern. Intraplaque HSI on TOF MRA in acute symptomatic carotid disease may help to determine the mechanism of stroke and establish early treatment plans.

Color-coded duplex sonography vs. 3.0 Tesla magnetic resonance angiography for detection of intracranial stenosis of the internal carotid artery: A prospective cohort study.

Hemodynamic changes may provide important information for clinical decision-making in internal carotid artery (ICA) stenosis. The degree of stenosis is responsible for the hemodynamic changes. For detection of intracranial stenosis, each diagnostic method has its own advantages and disadvantages. The goal of the present study was to compare the sensitivity and accuracy of color-coded duplex sonography with that of magnetic resonance angiography (MRA) for the detection of intracranial stenosis. Patients with 3 vessels and/or left stem coronary artery disease were subjected to transcranial and extracranial color-coded duplex sonography (n=998), MRA (n=998) and invasive catheter angiography (n=939). The degree of stenosis was defined according to the Warfarin-Aspirin Symptomatic Intracranial Disease methodology. A ≥50% reduction in artery diameter was considered as a positive obstructive lesion. The benefits of each imaging method were assessed by clinical decision-making analysis. Color-coded duplex sonography and MRA, had sensitivities of 0.935 and 0.957 and accuracies of 0.92 and 0.974, respectively, when using invasive catheter angiography as a gold standard. The number of false-positive obstructive lesions detected by MRA was significantly higher than that for color-coded duplex sonography (53 vs. 13, P<0.0001). Color-coded duplex sonography was able to detect an obstructive lesion in one single image for ICAs with ≥57% stenosis, while MRA was only capable of detecting an obstructive lesion in one single image for ICAs with ≥80% stenosis. In conclusion, color-coded duplex sonography is a reliable method for the detection of intracranial stenosis in patients with coronary artery disease.

Subarachnoid Hemorrhage in Patients with Good Clinical Grade: Accuracy of 3.0-T MR Angiography for Detection and Characterization.

Purpose To evaluate the diagnostic accuracy of aneurysm detection and the fidelity of morphologic characterization of three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography at 3.0 T in patients with a Glasgow coma score of 15 and noncontrast material-enhanced computed tomography (CT) findings that showed acute nontraumatic subarachnoid hemorrhage. Materials and Methods The institutional review board approved this prospective study, and patients provided informed consent. A total of 277 patients who had not experienced trauma but in whom nonenhanced CT showed subarachnoid hemorrhage, who had a Glasgow coma score of 15, and who underwent both 3D TOF MR angiography and digital subtraction angiography (DSA) (the reference standard) were included. Three observers who were blinded to clinical and DSA results independently analyzed all 3D TOF MR angiographic data sets. The receiver operating characteristic curve was applied to analysis of the detection of aneurysms with 3D TOF MR angiography by using patient- and aneurysm-based evaluations. Multivariate logistic regression analysis was performed to identify aneurysm-specific variables, including size, shape (daughter sac/lobulation/margin), neck width (wide if > 4 mm or if fundus-to-neck ratio was < 2), and relation to adjacent artery, that significantly affected morphologic assessment with 3D TOF MR angiography. Results Aneurysms were depicted with DSA in 225 patients. In patient- and aneurysm-based evaluations, respectively, 3D TOF MR angiography yielded accuracies of 96.8% (268 of 277) and 96.6% (309 of 320), sensitivities of 98.2% (219 of 223) and 98.1% (260 of 265), specificities of 91% (49 of 54) and 89% (49 of 55), positive predictive values of 97.8% (219 of 224) and 97.7% (260 of 266), and negative predictive values of 92% (49 of 53) and 91% (49 of 54). Accuracy of display of morphologic features was 92.5% (236 of 255) for size, 86.3% (220 of 255) for neck width, 94.5% for shape (241 of 255), and 96.9% (247 of 255) for relationship to adjacent vessel. Width of aneurysm neck was the only variable that significantly affected the morphologic assessment of 3D TOF MR angiography (odds ratio, 0.378; 95% confidence interval: 0.337, 8.347; P = .004). Conclusion Three-dimensional TOF MR angiography can accurately depict cerebral aneurysms and accurately display their morphologic features in stable patients with subarachnoid hemorrhage and a Glasgow coma score of 15. © RSNA, 2017.

Diagnostic accuracy of magnetic resonance angiography for detection of coronary artery disease: a systematic review and meta-analysis.

To review the diagnostic performance of MR coronary angiography (MRCA) for coronary artery disease (CAD). Two independent reviewers searched on MEDLINE/EMBASE with the following inclusion criteria: 01/01/2000-03/23/2015 publication date; per-patient sensitivity/specificity for >50% stenosis confirmed by conventional coronary angiography with raw data provided or retrievable; sample size >10. Quality was appraised using QUADAS2. Nine hundred eighteen studies were retrieved, 24 of them, including 1,638 patients, were selected. Using a bivariate model, the pooled sensitivity was 89% (95% confidence interval 86-92%), the pooled specificity 72% (63-79%). Meta-regression did not show a significant impact on sensitivity/specificity for both year of publication and disease prevalence (p ≥ 0.114). Sensitivity of contrast-enhanced examinations (95%, 90-97%) was higher (p = 0.005) than that of unenhanced examinations (87%, 83-90%). Specificity of whole-heart acquisition mode (78%, 72-84%) was higher (p = 0.006) than that of targeted mode (57%, 45-69%). Specificity at 3T (83%, 69-92%) was higher (p = 0.067) than that at 1.5T (68%, 60-76%). Risk of bias and concerns regarding applicability were low. Sensitivity and specificity of MRCA for CAD were 89% and 72%, respectively. A specificity higher than 80% may be obtained at 3T. Whole-heart contrast-enhanced protocols should be preferred for a higher diagnostic performance. • MRCA sensitivity and specificity for CAD are below those of CTA. • Contrast administration increased sensitivity to 95 % (90-97 %), comparable with that of CTA. • Whole-heart mode increased specificity to 78 % (72-84 %), comparable with that of CTA. • Specificity at 3T was borderline-significantly higher (p = 0.067) than at 1.5T. • Whole-heart contrast-enhanced protocols are the best approach for MRCA.

Computed Tomographic Angiography or Magnetic Resonance Angiography for Detection of Intracranial Vascular Malformations in Patients With Intracerebral Hemorrhage

Early identification of an intracranial vascular malformation (IVM; brain or pial/dural arteriovenous malformations/fistulae, and aneurysms) after intracerebral hemorrhage (ICH) may improve outcome if treatment can prevent recurrence. Intra-arterial digital subtraction angiography (IADSA) is the reference standard for detection of IVMs as the cause of ICH. Computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) are less invasive than IADSA and may be as accurate. We performed a systematic review of the diagnostic test accuracy of CTA and MRA compared with IADSA for the detection of IVMs as a cause of ICH. We searched MEDLINE (1948 to August 2013), EMBASE (1980 to August 2013), MEDION (August 2013), the Database of Abstracts of Reviews of Effects (August 2013), …

Computed tomography angiography or magnetic resonance angiography for detection of intracranial vascular malformations in patients with intracerebral haemorrhage.

Intracranial vascular malformations (brain or pial/dural arteriovenous malformations/fistulae, and aneurysms) are the leading cause of intracerebral haemorrhage (ICH) in young adults. Early identification of the intracranial vascular malformation may improve outcome if treatment can prevent ICH recurrence. Catheter intra-arterial digital subtraction angiography (IADSA) is considered the reference standard for the detection an intracranial vascular malformation as the cause of ICH. Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are less invasive than IADSA and may be as accurate for identifying some causes of ICH. To evaluate the diagnostic test accuracy of CTA and MRA versus IADSA for the detection of intracranial vascular malformations as a cause of ICH. We searched MEDLINE (1948 to August 2013), EMBASE (1980 to August 2013), MEDION (August 2013), the Database of Abstracts of Reviews of Effects (DARE; August 2013), the Health Technology Assessment Database (HTA; August 2013), ClinicalTrials.gov (August 2013), and WHO ICTRP (International Clinical Trials Register Portfolio; August 2013). We also performed a cited reference search for forward tracking of relevant articles on Google Scholar (http://scholar.google.com/), screened bibliographies, and contacted authors to identify additional studies. We selected studies reporting data that could be used to construct contingency tables that compared CTA or MRA, or both, with IADSA in the same patients for the detection of intracranial vascular malformations following ICH. Two authors (CBJ and RA-SS) independently extracted data on study characteristics and measures of test accuracy. Two authors (CBJ and PMW) independently extracted data on test characteristics. We obtained data restricted to the subgroup undergoing IADSA in studies using multiple reference standards. We combined data using the bivariate model. We generated forest plots of the sensitivity and specificity of CTA and MRA and created a summary receiver operating characteristic plot. Eleven studies (n = 927 participants) met our inclusion criteria. Eight studies compared CTA with IADSA (n = 526) and three studies compared MRA with IADSA (n = 401). Methodological quality varied considerably among studies, with partial verification bias in 7/11 (64%) and retrospective designs in 5/10 (50%). In studies of CTA, the pooled estimate of sensitivity was 0.95 (95% confidence interval (CI) 0.90 to 0.97) and specificity was 0.99 (95% CI 0.95 to 1.00). The results remained robust in a sensitivity analysis in which only studies evaluating adult patients (≥ 16 years of age) were included. In studies of MRA, the pooled estimate of sensitivity was 0.98 (95% CI 0.80 to 1.00) and specificity was 0.99 (95% CI 0.97 to 1.00). An indirect comparison of CTA and MRA using a bivariate model incorporating test type as one of the parameters failed to reveal a statistically significant difference in sensitivity or specificity between the two imaging modalities (P value = 0.6). CTA and MRA appear to have good sensitivity and specificity following ICH for the detection of intracranial vascular malformations, although several of the included studies had methodological shortcomings (retrospective designs and partial verification bias in particular) that may have increased apparent test accuracy.

Diagnostic Accuracy of Computer Tomography Angiography and Magnetic Resonance Angiography in the Stenosis Detection of Autologuous Hemodialysis Access: A Meta-Analysis

PurposeTo compare the diagnostic performances of computer tomography angiography (CTA) and magnetic resonance angiography (MRA) for detection and assessment of stenosis in patients with autologuous hemodialysis access.Materials and MethodsSearch of PubMed, MEDLINE, EMBASE and Cochrane Library database from January 1984 to May 2013 for studies comparing CTA or MRA with DSA or surgery for autologuous hemodialysis access. Eligible studies were in English language, aimed to detect more than 50% stenosis or occlusion of autologuous vascular access in hemodialysis patients with CTA and MRA technology and provided sufficient data about diagnosis performance. Methodological quality was assessed by the Quality Assessment of Diagnostic Studies (QUADAS) instrument. Sensitivities (SEN), specificities (SPE), positive likelihood ratio (PLR), negative likelihood values (NLR), diagnostic odds ratio (DOR) and areas under the receiver operator characteristic curve (AUC) were pooled statistically. Potential threshold effect, heterogeneity and publication bias was evaluated. The clinical utility of CTA and MRA in detection of stenosis was also investigated.ResultSixteen eligible studies were included, with a total of 500 patients. Both CTA and MRA were accurate modality (sensitivity, 96.2% and 95.4%, respectively; specificity, 97.1 and 96.1%, respectively; DOR [diagnostic odds ratio], 393.69 and 211.47, respectively) for hemodialysis vascular access. No significant difference was detected between the diagnostic performance of CTA (AUC, 0.988) and MRA (AUC, 0.982). Meta-regression analyses and subgroup analyses revealed no statistical difference. The Deek’s funnel plots suggested a publication bias.ConclusionDiagnostic performance of CTA and MRA for detecting stenosis of hemodialysis vascular access had no statistical difference. Both techniques may function as an alternative or an important complement to conventional digital subtraction angiography (DSA) and may be able to help guide medical management.

Analysis of the difference of three imaging methods of the MRA in detection of cerebral infarction

Objective To compare the clinical value of fluid attenuated inversion recovery imaging (FLAIR),magnetic resonance diffusion-weighted imaging(DWI) and magnetic resonance angiography(MRA) in diagnosis of early cerebral infarction.Methods 70 cerebral infarction patients were chosen.They underwent FLAIR,DWI and MRA examination.Results 70 patients with early cerebral infarction mostly were multiple lessions accouting for 60％.Supper actue period had 22 cases and acute period had 48 cases.DWI had the highest detection rate of cerebral infarction,particularly in the hyperacute period the detection rate reached 100％,which was significantly higher than the FLAIR and MRA(x2 =12.4,P ＜ 0.05).Conclusion Especially in the early diagnosis of hyperacute cerebral infarction,DWI is superior to FLAIR and MRA.FLAIR showed better on the cortex and periventricular lesions,MRA can check out the blood vessel lesions in the infarction area. Key words: Inversion recovery imaging; Magnetic resonance diffusion-weighted imaging; Magnetic resonance angiography; Cerebral infarction

MR Angiography for Detection of Pulmonary Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia

MR Angiography for Detection of Pulmonary Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia

Clinical feasibility of free-breathing, gadolinium-enhanced magnetic resonance angiography for assessing extracardiac thoracic vascular abnormalities in young children with congenital heart diseases

Congenital heart diseases in pediatric patients are associated with a wide variety of extracardiac thoracic vascular abnormalities. This study analyzed the value of gadolinium-enhanced magnetic resonance angiography during quiet free breathing for assessing extracardiac thoracic vascular abnormalities in young children with congenital heart diseases. Fifty-three children with congenital heart diseases (age range, 1 day-40 months; mean, 10.9 months) associated with extracardiac thoracic vascular abnormalities who had undergone both free-breathing, gadolinium-enhanced magnetic resonance angiography and cardiac catheterization, surgical intervention, or both within 2 weeks were reviewed. Diagnostic findings on gadolinium-enhanced magnetic resonance angiography among patients grouped according to 3 major conditions of conotruncal abnormalities (n = 33), aortic or venous abnormalities (n = 11), and pulmonary vascular abnormalities (n = 9), as well as associated extracardiac thoracic vascular abnormality findings, were compared with findings made by using cardiac catheterization, surgical intervention, or both. Extracardiac thoracic vascular abnormality findings on gadolinium-enhanced magnetic resonance angiography were similar to those on catheterization, surgical intervention, or both in patients with conotruncal abnormalities (124 vs 127, P = .083), aortic or venous abnormalities (36 vs 33, P = .083), and pulmonary vascular abnormalities (24 vs 25, P = .317). The overall sensitivity of gadolinium-enhanced magnetic resonance angiography for detection of these lesions identified by means of catheterization, surgical intervention, or both was 97.9%. However, gadolinium-enhanced magnetic resonance angiography revealed 11 additional extracardiac thoracic vascular abnormalities that were not found on cardiac catheterization. The kappa coefficient for the correlation of image quality and diagnostic value of gadolinium-enhanced magnetic resonance angiography by using a 4-point-scale (1 = nondiagnostic to 4 = excellent) assessed by 2 independent reviewers was excellent (mean score = 3.66), with superb interobserver agreement (kappa = 0.727-0.874). Free-breathing, gadolinium-enhanced magnetic resonance angiography is clinically feasible for detailed anatomic delineation and treatment planning of various extracardiac thoracic vascular abnormalities in young children with congenital heart diseases.

Combination of free‐breathing and breathhold steady‐state free precession magnetic resonance angiography for detection of coronary artery stenoses

To analyze the incremental diagnostic value of a combination of two approaches (free-breathing and breathhold) vs. the sole free-breathing approach to coronary magnetic resonance angiography (CMRA) for detection of significant stenoses. Thirty patients were consecutively included in this prospective trial. CMRA was performed on a 1.5-T MR scanner (Magnetom Sonata, Siemens) using a balanced steady-state free precession (SSFP) sequence during free-breathing (2.4 x 0.9 x 0.7 mm3). Breathholding acquisitions (3.0 x 1.5 x 0.7 mm3) were only performed in cases in which the quality of free-breathing CMRA precluded assessment. Patients with contraindications to CMRA, claustrophobia, or nonassessable images were not excluded from the assessment of diagnostic accuracy (intention-to-diagnose design). In 60% of all free-breathing coronary acquisitions the image quality was adequate for diagnostic assessment. For the remaining 40% of the cases, breathhold acquisitions were obtained. The sensitivity, specificity, nonassessable rate, and accuracy in identifying main coronary branches with significant stenoses using the combination of both breathing approaches and the free-breathing approach alone were 65% vs. 32%, 73% vs. 53%, 24% vs. 52%, and 71% vs. 46%, respectively (P < 0.001). In this consecutive cohort of patients, the combination of free-breathing and breathhold CMRA significantly improved diagnostic accuracy. Nevertheless, even this combination did not reach accuracies sufficient for routine clinical application.

Angiographie par résonance magnétique dans les anévrismes et pseudoanévrismes des artères splanchniques

Purpose To correlate Magnetic resonance angiography (MRA) with computed tomography for the diagnosis of splanchnic artery aneurysms. Materials-methods We retrospectively reviewed the MRA findings of splanchnic arteries performed in 16 patients with known splanchnic aneurysms. Sixteen patients underwent computed tomography (CT), and MRA. Conventional angiogram was performed to confirm the diagnosis in six cases. This study was conducted on a 1.5T MR Symphony system (Siemens, Erlangen, Germany). CE-MRA was performed by using a 3D RF-spoiled FLASH sequence. Acquisition of source images was performed in the coronal plane and reconstructed by means of maximum-intensity projection (MIP) post-processing. Results Patient population included 7 men and 9 women aged from 31 to 85 years old (mean age 59.5 years old). Splanchnic aneurysms were located as follows: splenic (n=5), hepatic (n=6), celiac trunk (n=4) and gastroduodenal (n=1). In 9 cases, MRA provided results similar to CT. In 3 cases, MRA provided more accurate information on the location of the aneurysm or detected additional aneurysms. In 4 patients, a diagnosis of aneurysm was made first or only made on MRA. Conclusion This small series showed a good correlation between CT and MRA for detection and characterization of splanchnic aneurysms.

Accuracy of Semiautomated Analysis of 3D Contrast-Enhanced Magnetic Resonance Angiography for Detection and Quantification of Aortoiliac Stenoses

We sought to compare reproducibility and accuracy of semiautomated stenosis detection and quantification in 3D contrast-enhanced magnetic resonance angiography (CE-MRA) images with conventional evaluation of 3D CE-MRA in patients with peripheral arterial disease (PAD) by using intra-arterial digital subtraction angiography (IA-DSA) as standard of reference. Twenty-five patients with PAD underwent CE-MRA and IA-DSA. Three blinded observers independently evaluated CE-MRA datasets for stenoses in the aortoiliac region using semiautomated computer analysis. Semiautomated measurements were compared with conventional measurements of stenosis on CE-MRA datasets, as measured by 3 other independent observers blinded to all other measurements. Interobserver agreement was quantified using kappa (kappa) and intraclass correlation coefficients (ICCs). Sensitivity and specificity were determined for both semiautomated and conventional measurements. Semiautomated measurements were successful in 124 of the 125 arterial segments. The sensitivity of semiautomated measurements was 89% for all observers; specificity varied between 87% and 89%. For conventional measurements of CE-MRA, sensitivity varied between 79% and 86%; specificity was between 86% and 96%. There was good interobserver agreement between all readers for semiautomated measurements (combined kappa for all 3 observers together = 0.78; ICC = 0.82), as well as for conventional measurements (combined kappa = 0.70; and ICC = 0.83). Differences between ICCs, combined kappa values, and accuracy of both measurements were not significant (all P > 0.05). Semiautomated analysis of aortoiliac 3D CE-MRA has the same high accuracy for detection and quantification of stenoses as conventional readings of CE-MRA.

Magnetic resonance angiographic localization of the artery of Adamkiewicz for spinal cord blood supply

Background The purpose of this study was to determine whether the artery of Adamkiewicz (ARM) can be detected by magnetic resonance angiography and to determine the usefulness of preoperative magnetic resonance angiography evaluation of the ARM. Methods Between April 2000 and December 2003, 120 patients underwent magnetic resonance angiography for detection of the ARM. The morphology of the anterior spinal artery at the ARM junction, as revealed by magnetic resonance angiography, in 99 patients in whom ARM was preoperatively detected was classified into the following three types: noncontinuation of the anterior spinal artery above the ARM junction (type A), continuation of the anterior spinal artery above and below the ARM junction (type B), and noncontinuation of the anterior spinal artery below the ARM junction (type C). Results The ARMs were detected in 99 (83%) of 120 patients, and from a total of 110 ARMs 105 (95%) originated from intercostal arteries branching from the left side and 94 (86%) originated between Th9 and Th11. Two ARMs were found in 11 (11%) of 99 patients in whom ARMs were detected. In 107 patients, who underwent magnetic resonance angiography to reveal the morphology of the anterior spinal artery at the ARM junction, the patterns of the anterior spinal artery were type A in 59 patients (55%), type B in 21 patients (20%), type C in 3 patients (3%) and not classified in 24 patients (22%). No spinal cord injury occurred in patients in whom the ARM had been preoperatively detected. Conclusions Preoperative detection of the ARM is possible by magnetic resonance angiography and is very useful for reducing the incidence of ischemic injury of the spinal cord.

Rapid magnetic resonance angiography for detection of atherosclerosis

Choice of treatment for atherosclerosis depends on various clinical factors and radiological techniques. We aimed to assess the diagnostic accuracy of a new three-dimensional magnetic resonance angiography (3D MRA) strategy for the display of arterial vasculature from supra-aortic arteries to distal runoff vessels in 72 s. We examined five healthy volunteers and six patients over 6 weeks. Conventional digital subtraction angiography (DSA) was available as reference standard in all six patients. Magnetic resonance imaging was done on a commercially available 1.5 Tesla scanner. The imaging technique was based on the acquisition of five 3D data sets in rapid succession with an optimum single injection protocol. Compared with conventional catheter angiography, according to the findings of two independent and masked readers, whole-body MRA had overall sensitivities of 91% (95% CI 0.76-0.98) and 94% (0.8-0.99), and specificities of 93% (0.85-0.97) and 90% (0.82-0.96) for the detection of substantial vascular disease (luminal narrowing >50%), interobserver agreement for assessment of whole-body magnetic angiograms was very good (kappa=0.94; 95% CI 0.9-0.98). The technique provides a comprehensive non-invasive approach for morphological screening assessment of the arterial vasculature from supra-aortic arteries to the distal runoff arteries.

Magnetic resonance angiography for detection of occlusive neck and proximal vascular diseases

We reviewed magnetic resonance (MR) aortographies of the thoraco-cervical region of 422 patients. Two hundred sixty patients had ischemic cerebrovascular disease, 86 vertigo or dizziness, 22 syncope, 4 ischemic disease of the retina, 3 cervical bruit, and 47 had other intracranial diseases. MR aortography was performed on a 1.5 Tesla MRI using a special head-and-neck coil. Images were obtained using an overlapping multi-slab and three-dimensional time-of-flight technique. Of the 422 patients, 59 underwent conventional angiography, and the findings from their conventional arteriogram were compared with those of MR aortography. As a result, steno-occlusive lesions were found in the carotid system in 21.1% of the patients, in the vertebral system in 18.5%, and in the subclavian and innominate arteries in 2.1%. The diagnoses made based on the MR aortography were in accord with the diagnoses made with conventional arteriography in 49 patients (83.1%). In 8 patients (13.6%), however, the diagnosis based on the MR aortography was found to be overestimated compared with the definitive diagnosis with conventional angiography. In only 2 patients (3.3%), the MR aortography diagnosis was insufficient. Especially, subclavian steal was not diagnosed with the MR aortography, whereas the findings from the MR aortography helped to lead to the diagnosis of this abnormality. In conclusion, we found that MR aortography is a useful tool as a screening test for patients with occlusive extracranial cerebrovascular disease.

Usefulness of MR angiography in detection of persistent trigeminal arteries.

To examine the usefulness of magnetic resonance angiography (MRA) in detection of persistent trigeminal arteries (PTA). 3D-time-of-flight (TOF)-MRA images obtained from 1100 patients (798 males and 302 females aged 6-75 years with a mean of 55 years) at our and related institutions were examined retrospectively for PTA. The course of the PTA was classified into the posteromedial type and posterolateral type. Charts of the patients were also examined retrospectively for clinical symptoms related to PTA. PTA was observed in 5 (0.45%) of the 1100 patients, and no aneurysm or arteriovenous malformation was noted in any of these 5 patients. PTA was the posteromedial type in 2 and posterolateral type in 3. PTA was possibly related with clinical symptoms in only 1 patient with oculomotor paresis. MRA is useful for non-invasive screening for PTA.