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Koktzoglou I, Huang R, Ong AL, Aouad PJ, Walker MT, Edelman RR. High spatial resolution whole-neck MR angiography using thin-slab stack-of-stars quiescent interval slice-selective acquisition. Magn Reson Med 2020; 84:3316-3324. [PMID: 32521094 DOI: 10.1002/mrm.28339] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/01/2020] [Accepted: 05/03/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE To report a 3D multi-echo thin-slab stack-of-stars (tsSOS) quiescent-interval slice-selective (QISS) strategy for high-resolution magnetic resonance angiography (MRA) of the entire neck in under seven minutes. METHODS The neck arteries of eight subjects were imaged at 3 Tesla. Multi-echo 3D tsSOS QISS using a FLASH readout was compared with 3D tsSOS FLASH, 2D QISS, 2D TOF, and 3D TOF. A root-mean-square (RMS) combination of echo time images was tested. Evaluation metrics included arterial signal-to-noise ratio (SNR), arterial-to-muscle contrast-to-noise ratio (CNR), and image quality. RESULTS 3D multi-echo tsSOS QISS using a RMS combination of echo time images increased SNR and CNR by 60% and 63% with respect to the reconstruction obtained with the shortest echo time. 3D tsSOS QISS showed superior CNR with respect to 3D tsSOS FLASH imaging, and more than 3-fold higher SNR and CNR with respect to 2D radial QISS when normalized for voxel size. 3D tsSOS QISS provided good to excellent image quality that exceeded the image quality of 2D QISS, 2D TOF, and 3D TOF (P < .05). CONCLUSION Whole-neck high-resolution nonenhanced MRA is feasible using 3D tsSOS QISS, and produced image quality that exceeded those of competing nonenhanced MRA protocols at 3 Tesla.
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Affiliation(s)
- Ioannis Koktzoglou
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL, USA.,Pritzker School of Medicine, University of Chicago, Chicago, IL, USA
| | - Rong Huang
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL, USA
| | - Archie L Ong
- Pritzker School of Medicine, University of Chicago, Chicago, IL, USA.,Department of Neurology, NorthShore University HealthSystem, Evanston, IL, USA
| | - Pascale J Aouad
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL, USA.,Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Matthew T Walker
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL, USA.,Pritzker School of Medicine, University of Chicago, Chicago, IL, USA
| | - Robert R Edelman
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL, USA.,Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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Koktzoglou I, Aherne EA, Walker MT, Meyer JR, Edelman RR. Ungated nonenhanced radial quiescent interval slice-selective (QISS) magnetic resonance angiography of the neck: Evaluation of image quality. J Magn Reson Imaging 2019; 50:1798-1807. [PMID: 31077477 DOI: 10.1002/jmri.26781] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/24/2019] [Accepted: 04/25/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Standard-of-care time-of-flight (TOF) techniques for nonenhanced magnetic resonance angiography (NEMRA) of the carotid bifurcation and other cervical arteries often provide nondiagnostic image quality due to motion and flow artifacts. PURPOSE To perform an initial evaluation of an ungated radial quiescent-interval slice-selective (QISS) technique for NEMRA of the neck, in comparison with 2D TOF and contrast-enhanced magnetic resonance angiography (CEMRA). STUDY TYPE Retrospective. POPULATION Sixty patients referred for neck MR angiography. FIELD STRENGTH/SEQUENCE Ungated radial QISS at 3T. ASSESSMENT Three radiologists scored image quality of 18 arterial segments using a 4-point scale (1, nondiagnostic; 2, fair; 3, good; 4, excellent), and two radiologists graded proximal internal carotid stenosis using five categories (<50%, 50-69%, 70-99%, occlusion, nondiagnostic). STATISTICAL TESTS Friedman tests with post-hoc Wilcoxon signed-rank tests; unweighted Gwet's AC1 statistic; tests for equality of proportions. RESULTS Ungated radial QISS provided image quality that significantly exceeded 2D TOF (mean scores of 2.7 vs. 2.0, 2.7 vs. 2.2, and 2.9 vs. 2.3; P < 0.001, all comparisons), while CEMRA provided the best image quality (mean scores of 3.6, 3.7, and 3.5 for the three reviewers). Interrater agreement of image quality scores was substantial for CEMRA (AC1 = 0.70, P < 0.001), and moderate for QISS (AC1 = 0.43, P < 0.001) and TOF (AC1 = 0.41, P < 0.001). Compared with TOF, QISS NEMRA provided a significantly higher percentage of diagnostic segments for all three reviewers (91.0% vs. 71.7%, 93.5% vs. 72.9%, 95.5% vs. 85.2%; P < 0.0001) and demonstrated better agreement with CEMRA for grading of proximal internal carotid stenosis (AC1 = 0.94 vs. 0.73 for reviewer 1, P < 0.05; AC1 = 0.89 vs. 0.68 for reviewer 2, P < 0.05). DATA CONCLUSION In this initial study, ungated radial QISS significantly outperformed 2D TOF for the evaluation of the neck arteries, with overall better image quality and more diagnostic arterial segments, and improved agreement with CEMRA for grading stenosis of the proximal internal carotid artery. LEVEL OF EVIDENCE 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:1798-1807.
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Affiliation(s)
- Ioannis Koktzoglou
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA
| | - Emily A Aherne
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Matthew T Walker
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA
| | - Joel R Meyer
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA
| | - Robert R Edelman
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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Imasaka KI, Tayama E, Morita S, Tomita Y. Neurological outcome and efficacy of intensive craniocervical screening for elective cardiac surgery. Interact Cardiovasc Thorac Surg 2019; 26:216-223. [PMID: 29049799 DOI: 10.1093/icvts/ivx307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Accepted: 08/13/2017] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES To evaluate the efficacy of intensive craniocervical screening before elective cardiovascular surgery. METHODS A retrospective analysis of 1134 consecutive patients who underwent routine screening before cardiovascular surgery between November 2004 and December 2014 was conducted. The study was divided into 2 distinct cohorts of patients undergoing surgery: before (n = 500) and after (n = 634) the introduction of intensive screening in January 2009. In 2009, preoperative screening underwent a transition from the evaluation of carotid atherosclerosis alone to that of craniocervical atherosclerosis. Additionally, patients with moderate or greater stenosis on intensive screening underwent single-photon emission computed tomography with acetazolamide. Craniocervical atherosclerosis was classified as no or mild [0-49%: n = 836 (before/after: 370/466)], moderate [50-69%: n = 118 (56/62)] or severe [70-100%: n = 141 (36/105)]. One of 166 (0.6%) patients with moderate or greater stenosis undergoing single-photon emission computed tomography with acetazolamide after the introduction of intensive screening was diagnosed as having impaired cerebral autoregulation. RESULTS The occurrences of perioperative stroke were 2.8% before the introduction of intensive screening and 0.9% after that (P = 0.033). Notably, intraoperative stroke significantly decreased from 1.4% to 0.2% (P = 0.034). Specifically, the occurrence of perioperative stroke in patients with no or mild stenosis decreased significantly after the introduction of intensive screening, from 2.7% to 0.4% (P = 0.007). CONCLUSIONS The incidence of perioperative stroke decreased following the introduction of intensive screening. Intensive screening may be able to detect patients with a greater risk of perioperative stroke.
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Affiliation(s)
- Ken-Ichi Imasaka
- Department of Cardiovascular Surgery, Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan
| | - Eiki Tayama
- Department of Cardiovascular Surgery, Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan
| | - Shigeki Morita
- Department of Cardiovascular Surgery, Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan
| | - Yukihiro Tomita
- Department of Cardiovascular Surgery, Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan
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Imura H, Maruyama Y, Amitani R, Maeda M, Shirakawa M, Nitta T. Long-term impact of critical silent cerebrovascular disease in patients undergoing coronary artery bypass surgery: a propensity score and multivariate analyses. Perfusion 2018; 34:147-153. [PMID: 30444180 DOI: 10.1177/0267659118813042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Cerebrovascular disease (CVD) with brain hypoperfusion is a strong risk factor for stroke. However, how this pathology influences long-term outcomes after coronary artery bypass graft (CABG) surgery is not known. METHODS Magnetic resonance imaging/angiography (MRI/A) of the neck and brain was performed in 318 out of 575 consecutive CABG patients between May 2005 and April 2018. Critical CVD with chronic hypoperfusion was defined as multiple severe stenoses (⩾70%) and/or occlusion in the carotid and/or vertebral systems associated with reduced collateral flow due to severe contralateral and/or circle of Willis lesion. Fifty patients were identified to have this pathology (early results were previously reported). The entire cohort was followed up for 83.6 ± 53.7 months. Carotid endarterectomy was considered for symptomatic patients. Propensity matching was performed to compare long-term outcomes between patients with and without critical CVD. RESULTS Patients with critical CVD at follow-up displayed significantly higher incidences of stroke than those without critical CVD (p=0.007), with an extremely high final incidence (approximately 40% at 8 years). However, survival (p=0.623) and incidences of major adverse cardiac events (MACE: myocardial infarction, coronary revascularization and all causes of death) (p=0.881) were similar. The Cox hazard model revealed that critical CVD was the strongest risk factor for stroke (p=0.000; hazard ratio 6.572; 95% confidence interval 2.657-16.258) while not affecting survival and MACE. CONCLUSION Critical CVD was the strongest risk factor for long-term stroke after CABG. However, survival and MACE-free rates were equivalent in patients with critical CVD and those without critical CVD.
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Affiliation(s)
- Hajime Imura
- 1 Department of Cardiovascular Surgery, Nippon Medical School Musashikosugi Hospital, Kawasaki, Kanagawa, Japan
| | - Yuji Maruyama
- 1 Department of Cardiovascular Surgery, Nippon Medical School Musashikosugi Hospital, Kawasaki, Kanagawa, Japan
| | - Ryosuke Amitani
- 1 Department of Cardiovascular Surgery, Nippon Medical School Musashikosugi Hospital, Kawasaki, Kanagawa, Japan
| | - Motohiro Maeda
- 1 Department of Cardiovascular Surgery, Nippon Medical School Musashikosugi Hospital, Kawasaki, Kanagawa, Japan
| | - Makoto Shirakawa
- 1 Department of Cardiovascular Surgery, Nippon Medical School Musashikosugi Hospital, Kawasaki, Kanagawa, Japan
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Imasaka KI, Tayama E, Tomita Y. The impact of carotid or intracranial atherosclerosis on perioperative stroke in patients undergoing open aortic arch surgery. J Thorac Cardiovasc Surg 2017; 153:1045-1053. [PMID: 28411747 DOI: 10.1016/j.jtcvs.2016.12.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 12/09/2016] [Accepted: 12/22/2016] [Indexed: 11/16/2022]
Abstract
OBJECTIVES This study aimed to clarify the impact of carotid or intracranial atherosclerosis on perioperative stroke in patients undergoing open aortic arch surgery. METHODS Between 2008 and 2015, 200 consecutive patients underwent elective aortic arch surgery with selective antegrade cerebral perfusion and moderate hypothermic circulatory arrest. Nonselective screening for carotid or intracranial atherosclerosis was performed using carotid ultrasonography or magnetic resonance angiography. Carotid or intracranial atherosclerosis was classified as below moderate (0%-49% stenosis), moderate (50%-69%), or severe (70%-100%). In patients with moderate or severe stenosis, cerebral hemodynamics were evaluated using single-photon emission computed tomography with acetazolamide. RESULTS None of the 37 patients undergoing preoperative single-photon emission computed tomography with acetazolamide had impaired cerebral hemodynamics. In-hospital mortality rate was 3.5% (7/200). Postoperative neurologic morbidity included permanent stroke in 8 patients (4.0%) and transient neurologic deficits in 27 patients (14%). Permanent stroke occurred in 3 of 159 patients (1.9%) with below moderate stenosis and 5 of 41 patients (12.2%) with moderate or severe stenosis (P = .008). Seven of 8 patients (87.5%) with stroke experienced multiple atherothrombotic embolizations, and 1 patient experienced a stroke of unknown cause. In multivariate analysis, previous cerebrovascular accident (odds ratio, 5.0; 95% confidence interval, 2.07-12.42; P = .0004) and shaggy aorta (odds ratio, 4.2; 95% confidence interval, 1.58-10.98; P = .0045) were significant determinants of neurologic morbidity. CONCLUSIONS Embolism was the major cause of permanent stroke in our patient population. Preoperative craniocervical and aortic screening may aid in modifying the operative strategy to reduce the occurrence of stroke.
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Affiliation(s)
- Ken-Ichi Imasaka
- Department of Cardiovascular Surgery, Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan
| | - Eiki Tayama
- Department of Cardiovascular Surgery, Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan
| | - Yukihiro Tomita
- Department of Cardiovascular Surgery, Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan.
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Koktzoglou I, Walker MT, Meyer JR, Murphy IG, Edelman RR. Nonenhanced hybridized arterial spin labeled magnetic resonance angiography of the extracranial carotid arteries using a fast low angle shot readout at 3 Tesla. J Cardiovasc Magn Reson 2016; 18:18. [PMID: 27067840 PMCID: PMC4828773 DOI: 10.1186/s12968-016-0238-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 03/24/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To evaluate ungated nonenhanced hybridized arterial spin labeling (hASL) magnetic resonance angiography (MRA) of the extracranial carotid arteries using a fast low angle shot (FLASH) readout at 3 Tesla. METHODS In this retrospective, institutional review board-approved and HIPAA-compliant study, we evaluated the image quality (4-point scale) of nonenhanced hASL MRA using a FLASH readout with respect to contrast-enhanced MRA (CEMRA) in 37 patients presenting with neurologic symptoms. Two certified neuroradiologists independently evaluated 407 arterial segments (11 per patient) for image quality. The presence of vascular pathology was determined by consensus reading. Gwet's AC1 was used to assess inter-rater agreement in image quality scores, and image quality scores were correlated with age and body mass index. Objective measurements of arterial lumen area and sharpness in the carotid arteries were compared to values obtained with CEMRA. Comparisons were also made with conventional nonenhanced 2D time-of-flight (TOF) MRA. RESULTS CEMRA provided the best image quality, while nonenhanced hASL FLASH MRA provided image quality that exceeded 2D TOF at the carotid bifurcation and in the internal and external carotid arteries. All nine vascular abnormalities of the carotid and intracranial arteries detected by CEMRA were depicted with hASL MRA, with no false positives. Inter-rater agreement of image quality scores was highest for CEMRA (AC1 = 0.87), followed by hASL (AC1 = 0.61) and TOF (AC1 = 0.43) (P < 0.001, all comparisons). With respect to CEMRA, agreement in cross-sectional lumen area was significantly better with hASL than TOF in the common carotid artery (intraclass correlation (ICC) = 0.90 versus 0.66; P < 0.05) and at the carotid bifurcation (ICC = 0.87 versus 0.54; P < 0.05). Nonenhanced hASL MRA provided superior arterial sharpness with respect to CEMRA and 2D TOF (P < 0.001). CONCLUSION Although inferior to CEMRA in terms of image quality and inter-rater agreement, hASL FLASH MRA offers an alternative to 2D TOF for the nonenhanced evaluation of the extracranial carotid arteries at 3 Tesla. Compared with 2D TOF, nonenhanced hASL FLASH MRA provides improved quantification of arterial cross-sectional area, vessel sharpness, inter-rater agreement and image quality.
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Affiliation(s)
- Ioannis Koktzoglou
- />Department of Radiology, NorthShore University HealthSystem, Evanston, USA
- />University of Chicago Pritzker School of Medicine, Chicago, USA
| | - Matthew T. Walker
- />Department of Radiology, NorthShore University HealthSystem, Evanston, USA
- />University of Chicago Pritzker School of Medicine, Chicago, USA
| | - Joel R. Meyer
- />Department of Radiology, NorthShore University HealthSystem, Evanston, USA
- />University of Chicago Pritzker School of Medicine, Chicago, USA
| | - Ian G. Murphy
- />Department of Radiology, NorthShore University HealthSystem, Evanston, USA
- />Northwestern University Feinberg School of Medicine, Chicago, USA
| | - Robert R. Edelman
- />Department of Radiology, NorthShore University HealthSystem, Evanston, USA
- />Northwestern University Feinberg School of Medicine, Chicago, USA
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van der Pol CB, McInnes MDF, Petrcich W, Tunis AS, Hanna R. Is quality and completeness of reporting of systematic reviews and meta-analyses published in high impact radiology journals associated with citation rates? PLoS One 2015; 10:e0119892. [PMID: 25775455 PMCID: PMC4361663 DOI: 10.1371/journal.pone.0119892] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 01/20/2015] [Indexed: 01/01/2023] Open
Abstract
Purpose The purpose of this study is to determine whether study quality and completeness of reporting of systematic reviews (SR) and meta-analyses (MA) published in high impact factor (IF) radiology journals is associated with citation rates. Methods All SR and MA published in English between Jan 2007–Dec 2011, in radiology journals with an IF >2.75, were identified on Ovid MEDLINE. The Assessing the Methodologic Quality of Systematic Reviews (AMSTAR) checklist for study quality, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist for study completeness, was applied to each SR & MA. Each SR & MA was then searched in Google Scholar to yield a citation rate. Spearman correlation coefficients were used to assess the relationship between AMSTAR and PRISMA results with citation rate. Multivariate analyses were performed to account for the effect of journal IF and journal 5-year IF on correlation with citation rate. Values were reported as medians with interquartile range (IQR) provided. Results 129 studies from 11 journals were included (50 SR and 79 MA). Median AMSTAR result was 8.0/11 (IQR: 5–9) and median PRISMA result was 23.0/27 (IQR: 21–25). The median citation rate for SR & MA was 0.73 citations/month post-publication (IQR: 0.40–1.17). There was a positive correlation between both AMSTAR and PRISMA results and SR & MA citation rate; ρ=0.323 (P=0.0002) and ρ=0.327 (P=0.0002) respectively. Positive correlation persisted for AMSTAR and PRISMA results after journal IF was partialed out; ρ=0.243 (P=0.006) and ρ=0.256 (P=0.004), and after journal 5-year IF was partialed out; ρ=0.235 (P=0.008) and ρ=0.243 (P=0.006) respectively. Conclusion There is a positive correlation between the quality and the completeness of a reported SR or MA with citation rate which persists when adjusted for journal IF and journal 5-year IF.
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Affiliation(s)
| | - Matthew D. F. McInnes
- Department of Radiology, University of Ottawa, Ottawa, Ontario, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- * E-mail:
| | - William Petrcich
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Adam S. Tunis
- Department of Radiology, University of Ottawa, Ottawa, Ontario, Canada
| | - Ramez Hanna
- Department of Radiology, University of Ottawa, Ottawa, Ontario, Canada
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8
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Koktzoglou I, Giri S, Piccini D, Grodzki DM, Flanagan O, Murphy IG, Gupta N, Collins JD, Edelman RR. Arterial spin labeled carotid MR angiography: A phantom study examining the impact of technical and hemodynamic factors. Magn Reson Med 2015; 75:295-301. [PMID: 25684192 DOI: 10.1002/mrm.25611] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 12/17/2014] [Accepted: 12/18/2014] [Indexed: 11/07/2022]
Abstract
PURPOSE To quantify the accuracy of three-dimensional (3D) radial arterial spin labeled (ASL) magnetic resonance angiography (MRA) using vascular models of carotid stenosis. METHODS Eight vascular models were imaged at 1.5 Tesla using pulsatile flow waveforms at rates found in the internal carotid arteries (100-400 mL/min). The impacts of the 3D ASL imaging readout (fast low angle shot (FLASH) versus balanced steady-state free precession (bSSFP)), ultrashort echo time imaging using a pointwise encoding time reduction with radial acquisition (PETRA), and model stenosis severity on the accuracy of vascular model display at the location of stenosis were quantified. Accuracy was computed vis-à-vis a reference bSSFP volume acquired under no flow. Comparisons were made with standard-of-care contrast-enhanced MRA (CEMRA) and Cartesian time-of-flight (TOF) MRA protocols. RESULTS For 50% and 70% stenoses, CEMRA was most accurate (respective accuracies of 81.7% and 78.6%), followed by ASL FLASH (75.7% and 71.8%), ASL PETRA (69.6% and 70.6%), 3D TOF (66.6% and 57.1%), ASL bSSFP (68.7% and 51.2%), and 2D TOF (65.1% and 50.6%). CONCLUSION Flow phantom imaging studies show that ASL MRA can improve the display of hemodynamically significant carotid arterial stenosis compared with TOF MRA, with FLASH and ultrashort echo time readouts being most accurate.
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Affiliation(s)
- Ioannis Koktzoglou
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,The University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA
| | | | - Davide Piccini
- Advanced Clinical Imaging Technology, Siemens Healthcare IM BM PI, Lausanne, Switzerland.,Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | | | - Oisin Flanagan
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Ian G Murphy
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - NavYash Gupta
- The University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA.,Department of Surgery, Division of Vascular Surgery, NorthShore University HealthSystem, Evanston, Illinois, USA
| | - Jeremy D Collins
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Robert R Edelman
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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9
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Imasaka KI, Yasaka M, Tayama E, Tomita Y. Obstructive carotid and/or intracranial artery disease rarely affects the incidence of haemodynamic ischaemic stroke during cardiac surgery: a study on brain perfusion single-photon emission computed tomography with acetazolamide. Eur J Cardiothorac Surg 2014; 48:739-46. [DOI: 10.1093/ejcts/ezu502] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Accepted: 11/26/2014] [Indexed: 11/14/2022] Open
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Menke J. Bayesian bivariate meta-analysis of sensitivity and specificity: summary of quantitative findings in 50 meta-analyses. J Eval Clin Pract 2014; 20:844-52. [PMID: 24828853 DOI: 10.1111/jep.12173] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/09/2014] [Indexed: 11/28/2022]
Abstract
RATIONALE, AIMS AND OBJECTIVES Meta-analyses of diagnostic test accuracy are important elements in evidence-based medicine. However, currently there is no overview of related quantitative findings that were obtained in a large number of real meta-analyses. This study aimed at providing such empirical summary. METHODS From the literature 50 meta-analyses were randomly selected that had reported their 2 × 2 count data of sensitivity and specificity. Descriptive statistics, assessment of between-study heterogeneity and bivariate random-effects meta-analysis of sensitivity and specificity were performed with a novel Bayesian program code. The bivariate model parameters were also converted to the parameters of the closely related hierarchical summary receiver operating characteristic (HSROC) model. RESULTS Among the 50 meta-analyses, the studies per meta-analysis ranged from 5 to 45 and the disease prevalence from 2.3 to 71%. Significant between-study heterogeneity was found in 43 of 50 meta-analyses, favouring a random-effects model over a fixed-effects model. Empirical distributions of sensitivity and specificity, positive and negative likelihood ratios, and other model results are presented in the full text numerically and graphically. CONCLUSIONS Studies of diagnostic test accuracy can be well meta-analysed within a Bayesian framework, and the presented quantitative findings provide an orientation when interpreting the results of the standard bivariate/HSROC model.
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Affiliation(s)
- Jan Menke
- Radiology Center, University Hospital Goettingen, Goettingen, Germany
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Menke J, Möller G. Cerebral near-infrared spectroscopy correlates to vital parameters during cardiopulmonary bypass surgery in children. Pediatr Cardiol 2014; 35:155-63. [PMID: 23852460 DOI: 10.1007/s00246-013-0754-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 06/19/2013] [Indexed: 10/26/2022]
Abstract
Near-infrared spectroscopy (NIRS) can monitor changes in cerebral regional oxygen saturation (rSO2) and tissue hemoglobin content (HbT). The relation between cerebral NIRS readings and vital parameters has not been analyzed before at a fine temporal scale. This study analyzed this relation during cardiopulmonary bypass (CPB) surgery in 10 children (0-9 years, 1,770 min of data records) by using a novel random-coefficient model. The analysis indicated that a small number of patients is sufficient for obtaining significant results with this model. Changes of vital parameters explained 84.7 % of rSO2 changes and 90.7 % of HbT changes. Cerebral rSO2 correlated positively with perfusion pressure and inversely with body temperature (P < 0.05). Cerebral HbT correlated positively with perfusion pressure, central venous pressure, and temperature and inversely with arterial oxygen saturation (P < 0.05). During hypothermic circulatory arrest, the half-life of the exponential rSO2 decay correlated to the rSO2 reserve (P = 0.016). In conclusion, NIRS readings of cerebral hemoglobin content and tissue oxygen saturation correlate well to vital parameters during CPB surgery in children. NIRS may therefore become a monitoring device for the neuroprotective optimization of those vital parameters.
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Affiliation(s)
- Jan Menke
- Department of Pediatrics, University Hospital Goettingen, Robert-Koch-Strasse 40, 37075, Goettingen, Germany,
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12
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Ferré JC, Raoult H, Breil S, Carsin-Nicol B, Ronzière T, Gauvrit JY. Supra-aortic arteries: three-dimensional time-resolved k-t BLAST contrast-enhanced MRA using a nondedicated body coil at 3 tesla in acute ischemic stroke. J Magn Reson Imaging 2013; 40:1056-63. [PMID: 24222649 DOI: 10.1002/jmri.24466] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 09/14/2013] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To assess the image quality and diagnostic performance achieved by using supra-aortic 3D-TR-CE-k-t BLAST MRA and a nondedicated body coil as compared with conventional CE-MRA in patients with acute ischemic stroke. MATERIALS AND METHODS In this prospective study, 36 consecutive patients with a suspected acute ischemic stroke underwent both k-t BLAST MRA and conventional CE-MRA. Image quality was assessed using visual and quantitative criteria and the techniques were compared. Both techniques were compared for degree of visual and quantitative measurement of carotid stenosis. RESULTS Delineation of vessel lumen and overall diagnostic confidence were significantly better with CE-MRA, respectively 3.4 ± 0.5 and 3.3 ± 0.6 (mean score ± SD), than with k-t BLAST MRA, respectively 2.8 ± 0.4 and 2.9 ± 0.5 (P < 0.02). SNR and CNR were significantly higher for k-t BLAST MRA, respectively 33.5 ± 19.3 and 27.9 ± 19.3, than for CE-MRA, respectively 25.7 ± 10 and 20.4 ± 8.4 (P < 0.03). Intertechnique agreement was good for carotid stenosis characterization (κ = .763). For the 14 relevant stenosis, stenosis measurements were highly correlated between techniques (0.96; P < 0.0001). The Bland-Altman plot showed a low bias in assessment of the degree of stenosis (mean bias 2.1% ± 7.7). CONCLUSION k-t BLAST MRA using a nondedicated coil offering and dynamic information was a effective diagnostic tool for detection and characterization of carotid stenosis.
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Affiliation(s)
- Jean-Christophe Ferré
- CHU Rennes, Department of Neuroradiology, University Hospital of Rennes, Rennes, France
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Tunis AS, McInnes MDF, Hanna R, Esmail K. Association of Study Quality with Completeness of Reporting: Have Completeness of Reporting and Quality of Systematic Reviews and Meta-Analyses in Major Radiology Journals Changed Since Publication of the PRISMA Statement? Radiology 2013; 269:413-26. [DOI: 10.1148/radiol.13130273] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Menke J, Schramm P, Sohns JM, Kallenberg K, Staab W. Diagnosing flow residuals in coiled cerebral aneurysms by MR angiography: meta-analysis. J Neurol 2013; 261:655-62. [PMID: 23893001 PMCID: PMC3973941 DOI: 10.1007/s00415-013-7053-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Revised: 07/14/2013] [Accepted: 07/15/2013] [Indexed: 11/03/2022]
Abstract
This meta-analysis summarizes the accuracy of magnetic resonance angiography (MRA) for diagnosing residuals in coiled cerebral aneurysms by using the threefold Roy classification (residuals: none, neck, or sac). Four databases were searched from 2000 to June 2013 for eligible studies that compared MRA to digital subtraction angiography (DSA) and reported 3 × 3 count data of threefold Roy classification, or a reduced scheme of 2 × 2 count data. Bivariate and trivariate Bayesian random-effects models were used for meta-analysis. Among 27 included studies (2,119 coiled aneurysms in 1,809 patients) the average prevalence of DSA-confirmed sac residuals was 18.2 % (range 0-43 %). The pooled sensitivity was 88.0 % (95 % CI 81.4-94.0) and specificity was 97.2 % (94.6-99.0 %) for assessing sac residuals by MRA. In the trivariate meta-analysis, a "sac residual" finding at MRA had a high positive likelihood ratio of 28.2 (14.0-79.0). A "neck residual" finding had a moderate negative likelihood ratio of 0.246 (0.111-0.426), and the MRA finding of "no residual" had a good negative likelihood ratio of 0.044 (0.013-0.096). Subgroup analyses identified no significant influence of covariates on diagnostic accuracy (P > 0.05). In conclusion, in coiled cerebral aneurysms MRA with application of the threefold Roy classification is well suited for detecting or excluding sac residuals that might require retreatment.
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Affiliation(s)
- Jan Menke
- Department of Diagnostic Radiology, University Hospital, Robert-Koch-Strasse 40, 37075, Goettingen, Germany,
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15
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Menke J. Bivariate random-effects meta-analysis of sensitivity and specificity with the Bayesian SAS PROC MCMC: methodology and empirical evaluation in 50 meta-analyses. Med Decis Making 2013; 33:692-701. [PMID: 23475941 DOI: 10.1177/0272989x13475719] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND OBJECTIVE Meta-analysis allows for summarizing the sensitivities and specificities from several primary diagnostic test accuracy studies quantitatively. This article presents and evaluates a full Bayesian method for bivariate random-effects meta-analysis of sensitivity and specificity with SAS PROC MCMC. METHODS First, the formula of the bivariate random-effects model is presented. Then its implementation with the Bayesian SAS PROC MCMC is empirically evaluated, using the published 2 × 2 count data of 50 meta-analyses. The convergence of the Markov chains is analyzed visually and qualitatively. The results are compared with a Bayesian WinBUGS approach, using the Bland-Altman analysis for assessing agreement between 2 methods. RESULTS The 50 meta-analyses covered broad ranges of pooled sensitivity (17.4% to 98.8%) and specificity (60.0% to 99.7%), and the between-study heterogeneity varied as well. In all meta-analyses, the Markov chains converged well. The meta-analytic results from the SAS PROC MCMC and the WinBUGS random-effects approaches were nearly similar, showing close 95% limits of agreement for the pooled sensitivity (-0.06% to 0.05%) and specificity (-0.05% to 0.05%) without significant differences (P > 0.05). This indicates that the bivariate model is well implemented with both different statistical programs, without systematic differences arising from program attributes. CONCLUSIONS As alternative to a WinBUGS approach, the Bayesian SAS PROC MCMC is well suited for bivariate random-effects meta-analysis of sensitivity and specificity.
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Affiliation(s)
- Jan Menke
- Gesellschaft fu¨ r wissenschaftliche Datenverarbeitung Goettingen (GWDG), Goettingen, Germany; and Diagnostic Radiology, University Hospital, Goettingen, Germany (JM)
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Gitsioudis G, Stuber M, Arend I, Thomas M, Yu J, Hilbel T, Giannitsis E, Katus HA, Korosoglou G. Steady-state equilibrium phase inversion recovery ON-resonant water suppression (IRON) MR angiography in conjunction with superparamagnetic nanoparticles. A robust technique for imaging within a wide range of contrast agent dosages. J Magn Reson Imaging 2013; 38:836-44. [PMID: 23418107 DOI: 10.1002/jmri.24043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Accepted: 12/13/2012] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To investigate the ability of inversion recovery ON-resonant water suppression (IRON) in conjunction with P904 (superparamagnetic nanoparticles which consisting of a maghemite core coated with a low-molecular-weight amino-alcohol derivative of glucose) to perform steady-state equilibrium phase MR angiography (MRA) over a wide dose range. MATERIALS AND METHODS Experiments were approved by the institutional animal care committee. Rabbits (n = 12) were imaged at baseline and serially after the administration of 10 incremental dosages of 0.57-5.7 mgFe/Kg P904. Conventional T1-weighted and IRON MRA were obtained on a clinical 1.5 Tesla (T) scanner to image the thoracic and abdominal aorta, and peripheral vessels. Contrast-to-noise ratios (CNR) and vessel sharpness were quantified. RESULTS Using IRON MRA, CNR and vessel sharpness progressively increased with incremental dosages of the contrast agent P904, exhibiting constantly higher contrast values than T1 -weighted MRA over a very wide range of contrast agent doses (CNR of 18.8 ± 5.6 for IRON versus 11.1 ± 2.8 for T1 -weighted MRA at 1.71 mgFe/kg, P = 0.02 and 19.8 ± 5.9 for IRON versus -0.8 ± 1.4 for T1-weighted MRA at 3.99 mgFe/kg, P = 0.0002). Similar results were obtained for vessel sharpness in peripheral vessels, (Vessel sharpness of 46.76 ± 6.48% for IRON versus 33.20 ± 3.53% for T1-weighted MRA at 1.71 mgFe/Kg, P = 0.002, and of 48.66 ± 5.50% for IRON versus 19.00 ± 7.41% for T1-weighted MRA at 3.99 mgFe/Kg, P = 0.003). CONCLUSION Our study suggests that quantitative CNR and vessel sharpness after the injection of P904 are consistently higher for IRON MRA when compared with conventional T1-weighted MRA. These findings apply for a wide range of contrast agent dosages.
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Harloff A, Zech T, Wegent F, Strecker C, Weiller C, Markl M. Comparison of blood flow velocity quantification by 4D flow MR imaging with ultrasound at the carotid bifurcation. AJNR Am J Neuroradiol 2013; 34:1407-13. [PMID: 23413247 DOI: 10.3174/ajnr.a3419] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE 4D flow MR imaging is an emerging technique that allows visualization and quantification of 3D blood flow in vivo. However, representative studies evaluating its accuracy are lacking. Therefore, we compared blood flow quantification by using 4D flow MR imaging with US within the carotid bifurcation. MATERIALS AND METHODS Thirty-two healthy volunteers (age 25.3 ± 3.4 years) and 20 patients with ≥50% ICA stenosis (age 67.7 ± 7.4 years) were examined preoperatively and postoperatively by use of 4D flow MR imaging, with complete coverage of the left and right carotid bifurcation. Blood flow velocities were assessed with standardized 2D analysis planes distributed along the CCA and the ICA and were compared with US at baseline and postoperatively in patients. In addition, we tested reproducibility and interobserver agreement of 4D MR imaging in 10 volunteers. RESULTS Overall, 101 CCAs and 79 ICAs were available for comparison. MR imaging underestimated (P < .05) systolic CCA and ICA blood flow velocity by 26% (0.79 ± 0.29 m/s vs 1.06 ± 0.31 m/s) and 19% (0.72 ± 0.21 m/s vs 0.89 ± 0.27 m/s) compared with US. Diastolic blood flow velocities were similar for MR imaging and US (differences, 9% and 3%, respectively; not significant). Reproducibility and interobserver agreement of 4D flow MR imaging was excellent. CONCLUSIONS 4D flow MR imaging allowed for an accurate measurement of blood flow velocities in the carotid bifurcation of both volunteers and patients with only moderate underestimation compared with US. Thus, 4D flow MR imaging seems promising for a future combination with MRA to comprehensively assess ICA stenosis and related hemodynamic changes.
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Affiliation(s)
- A Harloff
- Department of Neurology, University Hospital, Freiburg, Germany.
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Menke J, Unterberg-Buchwald C, Staab W, Sohns JM, Seif Amir Hosseini A, Schwarz A. Head-to-head comparison of prospectively triggered vs retrospectively gated coronary computed tomography angiography: Meta-analysis of diagnostic accuracy, image quality, and radiation dose. Am Heart J 2013; 165:154-63.e3. [PMID: 23351817 DOI: 10.1016/j.ahj.2012.10.026] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 10/03/2012] [Indexed: 01/12/2023]
Abstract
BACKGROUND In coronary computed tomography (CT) angiography (CTA) prospective electrocardiography triggering requires less radiation dose than retrospective electrocardiography gating but provides less cardiac phases for interpretation. This meta-analysis presents a concise and comprehensive head-to-head comparison of image quality, diagnostic accuracy, and radiation dose of prospectively triggered coronary CTA vs retrospectively gated CTA in patients with suspected or known coronary artery disease (CAD). METHODS In patients with CAD and without tachyarrhythmia, eligible studies (selected from 4 databases) compared prospectively triggered vs retrospectively gated CTA (performed with ≥64-slice CT or dual-source CT) in 2 groups having approximately similar patient characteristics, scored CTA image quality, and/or assessed how accurately CTA diagnoses ≥50% coronary stenoses compared with catheter angiography and reported the radiation dose. The data were meta-analyzed by random-effects models, with CIs provided in the text. RESULTS Among 3,330 patients from 20 included studies, 91.3% of CTAs (segments: 97.8%) had diagnostic quality with prospective triggering and 93.3% of CTAs (segments: 98.4%) with retrospective gating (P > .05). Among 664 patients from 5 studies, the pooled sensitivity/specificity of diagnostic CTAs was 98.7%/91.3% (segment level: 91.3%/97.7%) with prospective triggering and 96.9%/95.8% (segment level: 93.1%/97.6%) with retrospective gating (P > .05). The pooled effective dose was 3.5 mSv with prospective triggering and thus, by a factor of 3.5, lower than the pooled effective dose of retrospective gating, which was 12.3 mSv (P < .01). CONCLUSIONS In patients with CAD and without tachyarrhythmia, prospectively triggered coronary CTA provides image quality and diagnostic accuracy comparable with retrospectively gated CTA, but at a much lower radiation dose.
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Affiliation(s)
- Jan Menke
- Department of Diagnostic Radiology, University Hospital, Goettingen, Germany.
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Li Y, Li X, Li D, Lu J, Xing X, Yan F, Li Y, Wang X, Iezzi R, De Cobelli F. Multicenter, intraindividual comparison of single-dose gadobenate dimeglumine and double-dose gadopentetate dimeglumine for MR angiography of the supra-aortic arteries (the Supra-Aortic VALUE study). AJNR Am J Neuroradiol 2012; 34:847-54. [PMID: 23042922 DOI: 10.3174/ajnr.a3298] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Gadobenate dimeglumine has markedly higher R1 relaxivity compared to gadopentetate dimeglumine meaning that lower doses can be used to achieve similar contrast enhancement. Our aim was to prospectively compare single-dose gadobenate dimeglumine with double-dose gadopentetate dimeglumine for contrast-enhanced MRA of the supra-aortic vasculature. MATERIALS AND METHODS Forty-six patients (37 men, 9 women; mean age, 63.5±10.1 years) with known or suspected steno-occlusive disease of the supra-aortic vessels underwent 2 identical CE-MRA examinations at 1.5T. Contrast agents were administered in randomized order, with the 2-fold greater volume of gadopentetate dimeglumine injected at a 2 times faster rate. Image assessment was performed by 3 independent blinded readers for vessel anatomic delineation, detection/exclusion of pathology, and global preference. Diagnostic performance (sensitivity, specificity, accuracy, PPV, and NPV) for detection of ≥60% stenosis was determined for 39/46 patients who underwent preinterventional DSA. Data were analyzed by using the Wilcoxon signed-rank, McNemar, and Wald tests in terms of the noninferiority of single-dose gadobenate dimeglumine compared with double-dose gadopentetate dimeglumine. Quantitative enhancement (signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)) was also compared. RESULTS All images were technically adequate. No differences (P=1.0) were noted by any reader for any qualitative parameter. All readers considered single-dose gadobenate dimeglumine and double-dose gadopentetate dimeglumine equivalent in at least 42/46 patients (91.3% three-reader agreement) for all parameters. Nonsignificant superiority for gadobenate dimeglumine was reported for all diagnostic performance indicators (sensitivity: 82.7%-88.5% versus 75.0%-80.8%; specificity: 96.4%-98.6% versus 94.6%-98.6%; accuracy: 94.6%-96.1% versus 92.4%-94.9%; PPV: 81.5%-91.5% versus 73.7%-90.7%; NPV: 96.8%-97.8% versus 95.4%-96.4%). No differences (P>.05) in quantitative enhancement were noted. CONCLUSIONS The image quality and diagnostic performance achieved with 0.1-mmol/kg gadobenate dimeglumine is at least equivalent to that achieved with 0.2-mmol/kg gadopentetate dimeglumine.
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Affiliation(s)
- Yanjun Li
- Department of Radiology, Shanghai Changhai Hospital, and Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Menke J, Larsen J, Kallenberg K. Diagnosing cerebral aneurysms by computed tomographic angiography: Meta-analysis. Ann Neurol 2011; 69:646-54. [DOI: 10.1002/ana.22270] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 09/16/2010] [Accepted: 09/17/2010] [Indexed: 12/13/2022]
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Sallustio F, Di Legge S, Marziali S, Ippoliti A, Stanzione P. Floating carotid thrombus treated by intravenous heparin and endarterectomy. J Vasc Surg 2011; 53:489-91. [DOI: 10.1016/j.jvs.2010.08.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2010] [Revised: 08/03/2010] [Accepted: 08/04/2010] [Indexed: 10/19/2022]
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Highly undersampled supraaortic MRA at 3.0 T: initial results with parallel imaging in two directions using a 16-channel neurovascular coil and parallel imaging factors up to 16. Magn Reson Imaging 2010; 28:1311-8. [PMID: 20692783 DOI: 10.1016/j.mri.2010.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 03/10/2010] [Accepted: 06/10/2010] [Indexed: 11/22/2022]
Abstract
PURPOSE To present the feasibility of highly undersampled contrast-enhanced MRA (CE-MRA) of the supraaortic arteries with a 16-channel neurovascular coil at 3.0 T using parallel imaging in two directions with parallel imaging factors (PIF) up to 16. MATERIALS AND METHODS Institutional review board approval and informed consent were obtained. In a prospective study, MRA protocols including PIF of 1, 2, 4, 9 and 16 yielding a spatial resolution from 0.81×0.81×1.0 mm(3) to 0.46×.46×0.98 mm(3) were acquired. In 32 examinations, image quality and vascular segments were rated independently by two radiologists. SNR estimations were performed for all MRA protocols. RESULTS The use of high PIF allowed to shorten acquisition time from 2:09 min down to 1:13 min and to increase the anatomic coverage while maintaining or even increasing spatial resolution down to 0.46×0.46×0.98 mm(3). The larger anatomic coverage that was achieved with the use of high PIF allowed for visualization of vascular structures that were not covered by the standard protocols. Despite the resulting lower SNR using high PIF, image quality was constantly rated to be adequate for diagnosis or better in all cases. CONCLUSION The use of high PIF yielded diagnostic image quality and allowed to increase the anatomic coverage while maintaining or even improving spatial resolution and shortening the acquisition time.
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