High Resolution Contrast-Enhanced MR Angiography in the Evaluation of Rabbit Carotid Artery

2005 ◽  
Vol 18 (5-6) ◽  
pp. 529-536
Author(s):  
R.-H. Wu ◽  
D.F. Kallmes

This study compared a high resolution contrast-enhanced MR angiography (MRA) sequence to conventional contrast-enhanced MRA sequence for imaging of rabbit carotid artery. Fifteen rabbits underwent an evaluation using both high resolution contrast-enhanced MRA sequence and conventional contrast-enhanced MRA sequence. Siemens 1.5 Tesla Magnetom Vision system was utilized. The parameters of high resolution sequence were: TR/TE= 6.2/2.0 msec, flip angle 25°, matrix 130×512, pixel size 0.96×0.49 mm, partition thickness 1.58 mm, acquisition time 24 sec. The parameters of conventional sequence were: TR/TE=3.8/1.4 msec, flip angle 35°, matrix 110×256, pixel size 1.48×1.02 mm, partition thickness 2mm, acquisition time 10 sec. Maximum intensity projection (MIP) images were created. Both original single slices and MIP images were used for image quality evaluation. Contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), distinctness of artery edge, and venous contamination were analyzed for both techniques. Higher average CNR and SNR were obtained with high resolution contrast-enhanced MRA, compared to average CNR and SNR with conventional contrast-enhanced MRA. The differences were statistically significant (P<0.01). The artery edge with high resolution method was more distinct than conventional method. Jugular venous contamination was found in five of 15 cases with high resolution contrast-enhanced MRA and in four of 15 cases with conventional contrast-enhanced MRA. High resolution contrast-enhanced MRA has significant potential for high quality noninvasive vascular imaging. The image quality with high resolution contrast-enhanced MRA sequence is better than conventional contrast-enhanced MRA sequence.

2006 ◽  
Vol 24 (4) ◽  
pp. 873-879 ◽  
Author(s):  
Gregory J. Wilson ◽  
William B. Eubank ◽  
G. Boudewijn C. Vasbinder ◽  
Alfons G.H. Kessels ◽  
Romhild M. Hoogeveen ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Carolin Reimann ◽  
Julia Brangsch ◽  
Jan Ole Kaufmann ◽  
Lisa C. Adams ◽  
David C. Onthank ◽  
...  

Objectives. The aim of this study was to test the potential of a new elastin-specific molecular agent for the performance of contrast-enhanced first-pass and 3D magnetic resonance angiography (MRA), compared to a clinically used extravascular contrast agent (gadobutrol) and based on clinical MR sequences. Materials and Methods. Eight C57BL/6J mice (BL6, male, aged 10 weeks) underwent a contrast-enhanced first-pass and 3D MR angiography (MRA) of the aorta and its main branches. All examinations were on a clinical 3 Tesla MR system (Siemens Healthcare, Erlangen, Germany). The clinical dose of 0.1 mmol/kg was administered in both probes. First, a time-resolved MRA (TWIST) was acquired during the first-pass to assess the arrival and washout of the contrast agent bolus. Subsequently, a high-resolution 3D MRA sequence (3D T1 FLASH) was acquired. Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were calculated for all sequences. Results. The elastin-specific MR probe and the extravascular imaging agent (gadobutrol) enable high-quality MR angiograms in all animals. During the first-pass, the probes demonstrated a comparable peak enhancement (300.6 ± 32.9 vs. 288.5 ± 33.1, p>0.05). Following the bolus phase, both agents showed a comparable intravascular enhancement (SNR: 106.7 ± 11 vs. 102.3 ± 5.3; CNR 64.5 ± 7.4 vs. 61.1 ± 7.2, p>0.05). Both agents resulted in a high image quality with no statistical difference (p>0.05). Conclusion. The novel elastin-specific molecular probe enables the performance of first-pass and late 3D MR angiography with an intravascular contrast enhancement and image quality comparable to a clinically used extravascular contrast agent.


2018 ◽  
Vol 42 (3) ◽  
pp. 109-115 ◽  
Author(s):  
Paige L. Rowland ◽  
Michelle Colpitts ◽  
Angela Malone ◽  
Munis Raza ◽  
Lenora L. Eberhart ◽  
...  

Ultrasound stratification for the degree of carotid artery disease based solely on lumen reduction has poorly predicted patient outcomes. This pilot study focused on patients with moderate carotid artery stenosis. Our purpose was to use contrast imaging with ultrasound to improve carotid field. A total of 10 patients diagnosed with moderate carotid artery stenosis were rescanned with an administration of a contrast imaging agent. Two-dimensional (2D) imaging, color, and Doppler were utilized to scan the patients. The 20 carotid arteries were blindly read by 2 experienced physicians. Visualization of far field, quality of Doppler envelope, plaque morphology, and overall image quality were semi-quantifiably assessed. With the use of a contrast imaging agent, there was a reduction in interphysician interpretation variability. The Kappa coefficient yielded an increase in agreement for postcontrast imaging in the majority of variables. The Doppler envelope showed improvement from precontrast (0.06) to postcontrast (0.63). The visualization of the far fields demonstrated a significant increase in agreement (0.77, 0.71, and 0.67) postcontrast. Plaque morphology demonstrated enhancement in characterization with contrast (–0.09 to 0.66). In this study, contrast-enhanced ultrasound (CEUS) was found to increase overall image quality. Improved interpretation can enhance risk stratification and with further exploration could be used to guide treatment plans for patients with asymptomatic moderate carotid artery disease.


2007 ◽  
Vol 25 (4) ◽  
pp. 832-840 ◽  
Author(s):  
Katja A. Mende ◽  
Johannes M. Froehlich ◽  
Constantin von Weymarn ◽  
Romhild Hoogeveen ◽  
Thomas Kistler ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Ivan Platzek ◽  
Dominik Sieron ◽  
Philipp Wiggermann ◽  
Michael Laniado

Purpose. The aim of this study was to assess the correlation of 3D time-of-flight MR angiography (TOF MRA) and contrast-enhanced MR angiography (CEMRA) for carotid artery stenosis evaluation at 3T.Material and Methods. Twenty-three patients (5 f, 18 m; mean age 61 y, age range 45–78 y) with internal carotid artery stenosis detected with ultrasonography were examined on a 3.0T MR system. The MR examination included both 3D TOF MRA and CEMRA of the carotid arteries. MR images were evaluated independently by two board-certified radiologists. Stenosis evaluation was based on a five-point scale. Stenosis grades determined by TOF and CEMRA were compared using Spearman’s rank correlation coefficient and the Wilcoxon test. Cohen’s Kappa was used to evaluate interrater reliability.Results. CEMRA detected stenosis in 24 (52%) of 46 carotids evaluated, while TOF detected stenosis in 27 (59%) of 46 carotids. TOF MRA yielded significantly higher results for stenosis grade in comparison to CEMRA (P=0.014). Interrater agreement was very good for both TOF MRA (κ=0.93) and CEMRA (κ=0.93).Conclusion. At 3T, 3D TOF MRA should not be used as replacement for contrast-enhanced MRA of the carotid arteries, as it results in significantly higher stenosis grades.


2010 ◽  
Vol 195 (6) ◽  
pp. 1423-1428 ◽  
Author(s):  
Oliver K. Mohrs ◽  
Steffen E. Petersen ◽  
Thomas Schulze ◽  
Michael Zieschang ◽  
Harald Küx ◽  
...  

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