(Circulation. 1999;99:3139-3148.)
© 1999 American Heart Association, Inc.
Clinical Investigation and Reports |
Improved Coronary Artery Definition With T2-Weighted, Free-Breathing, Three-Dimensional Coronary MRA
From the Department of Medicine, Cardiovascular Division (R.M.B., M.S., P.G.D., K.V.K., W.J.M.) and Department of Radiology (W.J.M.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Mass; and Philips Medical Systems (R.M.B., M.S.), Best, Netherlands.
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Abstract |
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 Top Abstract IntroductionMethodsResultsDiscussionAppendix 1References |
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Background—Three-dimensional (3D) navigator-gated and prospectively corrected free-breathing coronary magnetic resonance angiography (MRA) allows for submillimeter image resolution but suffers from poor contrast between coronary blood and myocardium. Data collected over >100 ms/heart beat are also susceptible to bulk cardiac and respiratory motion. To address these problems, we examined the effect of a T2 preparation prepulse (T2prep) for myocardial suppression and a shortened acquisition window on coronary definition.
Methods and Results—Eight healthy adult subjects and 5 patients with confirmed coronary artery disease (CAD) underwent free-breathing 3D MRA with and without T2prep and with 120- and 60-ms data-acquisition windows. The T2prep resulted in a 123% (P<0.001) increase in contrast-to-noise ratio (CNR). Coronary edge definition was improved by 33% (P<0.001). Acquisition window shortening from 120 to 60 ms resulted in better vessel definition (11%; P<0.001). Among patients with CAD, there was a good correspondence with disease.
Conclusions—Free-breathing, T2prep, 3D coronary MRA with a shorter acquisition window resulted in improved CNR and better coronary artery definition, allowing the assessment of coronary disease. This approach offers the potential for free-breathing, noninvasive assessment of the major coronary arteries.
Key Words: imaging • angiography • contrast media • vessels
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Introduction |
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TopAbstractIntroductionMethodsResultsDiscussionAppendix 1References |
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Coronary MR angiography (MRA) is able to depict the major coronary arteries.1 2 3 4 5 6 Several impediments, however, limit its clinical utility. These obstacles include compensation for cardiac and respiratory motion, need for submillimeter spatial resolution, and suppression of signal from adjacent epicardial fat and myocardium.
Initial approaches used 2-dimensional (2D) gradient-echo strategies1 2 3 5 7 8 to take advantage of unsaturated blood inflow and breath holding to minimize respiratory motion. In contrast to breath holding, respiratory bellows9 or MR navigator echoes that assess diaphragmatic or cardiac position can be used for respiratory gating with or without slice correction to allow for free-breathing coronary MRA.9 10 11 12 13 14 15 16 By eliminating the time constraint of the breath hold, navigators allow for submillimeter spatial resolution and minimize registration errors. Three-dimensional (3D) MRA techniques offer favorable signal-to-noise ratios (SNR) and are also well suited for navigator approaches.13 17 A disadvantage of 3D versus 2D MRA is lower contrast between coronary blood and myocardium. To overcome this problem, contrast agents18 or prepulses4 may be useful.
We chose to examine the impact of a T2 preparation prepulse (T2prep), which has been demonstrated to enhance contrast in 2D MRA applications.7 Because image quality may also be affected by respiratory motion during the data-acquisition window, we also varied the acquisition window between 60 and 120 ms. To avoid bias in image assessment, we developed an objective tool to determine vessel border sharpness. We hypothesized that the combination of 3D MRA with T2prep and a shorter acquisition window would allow for both improved contrast-to-noise ratio (CNR) and coronary edge definition.
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Methods |
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TopAbstractIntroductionMethodsResultsDiscussionAppendix 1References |
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Subjects
Eight healthy adults (mean age, 24 years; range, 18 to 37; 5 men) without a history of cardiovascular disease and 5 patients (mean age, 58 years; range, 42 to 71; 4 men) with radiographically confirmed coronary disease (CAD) were studied. No breath holds or respiratory coaching were performed. Written informed consent was obtained from all participants, and the protocol was approved by the hospital's Committee on Clinical Investigations.
Imaging Procedure
All subjects were examined supine with a commercial, 1.5-T
Gyroscan ACS-NT (Philips Medical Systems) scanner with PowerTrak 3000
gradients (15 mT/m, 50 mT · m-1 ·
ms-1 slew rate), a cardiac software patch, and a
5-element phased-array research cardiac coil.
Localizer Scans
Two scout scans were performed to localize the left main
(LM) coronary artery and to position the cardiac navigator. An
ECG-triggered multislice, multishot 2D turbo field echo scan with
thoracic transverse, sagittal, and coronal images was used to identify
the heart, followed by a coronal scout with left
ventricular (LV) navigator gating and prospective slice
correction.14 The coronal scout images were used to
localize the LM and position the LV navigator (Figure 1
).
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3D Coronary MRA With T2prep
The coronal scout position of the LM (Figure 1
) was used
as the "center slice" position of the 3D MRA scan. The MR pulse
sequence consisted of 4 blocks (Figure 2)
repeated with every heart cycle, with a temporal relationship chosen to
minimize the time interval between the navigator and the imaging
sequence.
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T2prep
Flow-independent coronary MRA with T2prep was first
described by Brittain et al.7 It uses a 90°
radiofrequency (RF) pulse to flip the Mz
magnetization vector into the Mxy plane and
is most beneficial in sequences with low inflow contrast. T2prep allows
suppression of tissues with short T2 relaxation times, eg, cardiac
muscle (T2=50 ms),19 cardiac veins with
deoxygenated blood (20% O2
saturation, T2=35 ms),20 and epicardial fat. Tissues with
long T2 relaxation times, eg, arterial blood (T2=250 ms),
are minimally influenced. The CNR between arterial blood
and myocardium can be adjusted by varying the time between
the 90° and the tip-up pulse.
Flow sensitivity of T2prep can be minimized by nonselective RF pulses and use of an even number of 180° refocusing pulses. We applied 4 refocusing pulses7 and used an MLEV (Malcom-Levitt)–weighted T2prep as well as composite 180° RF pulses (90x180y90x) to correct for pulse imperfections due to B0 and B1 field inhomogeneities.
CNR Optimization
A Bloch equation21 simulation, taking into account
arterial blood and myocardium T1 and T2 (at 1.5
T) of 1200 and 250 ms and 850 and 50 ms,19 22
respectively, was used. This demonstrated maximal CNR with 90-ms
T90–90 spacing. However, SNR drops as
T90–90 increases (Figure 3). On the basis of in vivo experiments,
the threshold for SNR of arterial blood was set to 8,
corresponding to a T90–90 of 50 ms, a reasonable
compromise between SNR and CNR (Figure 3).
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Navigator-Guided Prospective Slice Correction
A cranial-caudal–oriented 2D selective navigator through the
basal LV was used to compensate for respiratory
motion.16 23 Navigator gating with prospective slice
correction was used with a 3-mm gating window and slice correction in
the craniocaudal direction (principal respiratory motion). For motion
correction in slice-selection direction, the measured displacement was
translated in a frequency offset of the RF excitation pulse of the
imaging sequence. No scaling of the measured displacement was
performed. Scan efficiency was defined as accepted shots/total heart
beats.
Imaging Sequence
A frequency-selective fat-suppression pulse to suppress signal
from epicardial fat preceded the imaging acquisition. The field-of-view
was 360x305 mm with an image matrix of 512x304 (in-plane
resolution, 0.7x1.0 mm). The 3D slab had 10 slices with a 3
mm slice thickness, interpolated to 20 slices with a 1.5 mm
thickness. Each 3D volume slice was acquired in 38 shots by use of a
centric k-space ordering scheme with a 7.4-ms repetition time and
2.5-ms time echo. To examine the impact of the data-acquisition window,
imaging was performed with 120-ms (16 echoes/shot) and 60-ms (8
echoes/shot) acquisition windows. All data were acquired at mid
diastole.
Study Protocol
Three coronary scans were performed in all healthy
subjects. To investigate the impact of the T2prep on image quality,
scans with and without T2prep were performed in random order. In all
other aspects, imaging parameters were maintained,
including an acquisition window of 60 ms. The third scan used T2prep
with a 120-ms acquisition window.
SNR and CNR Evaluation
SNR of coronary blood was determined from a
region-of-interest in the ascending aorta at the level of the LM
origin. Mean blood signal (Sblood) and SD
(Nblood) were calculated, with SNR defined as
Sblood/Nblood. Contrast
between coronary blood and cardiac muscle was calculated as
 | (1) |
Mean muscle signal (Smuscle) was determined at the anterobasal LV. CNR was also calculated between proximal left anterior descending coronary artery (LAD; arterial) and great cardiac vein (venous) blood.
Curved-Plane Vessel Reconstruction
All data were analyzed on an EasyVision workstation
(Philips Medical Systems). The user navigates through the 3D data set
and interactively marks the vessel of interest. The course of the LAD
and left circumflex artery (LCx) are then reconstructed (Figure 4) and displayed in a single image
plane, from which the contiguous length of the LAD and LCx was then
determined.
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Vessel Edge Detection
Vessel tracing and edge detection were performed on gray-scale
images of the raw 3D data sets with the LAD and LCx slices closest to
the LM bifurcation. Edge detection included a centerline and
edge-detection procedure (Figure 5;
Appendix). Vessel sharpness was defined as the average edge value along
the calculated vessel border. Higher edge values correspond to better
vessel delineation.
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Patient Protocol
All patients with radiographically confirmed CAD
underwent T2prep 3D MRA with the short (60 ms) acquisition window. The
3D MRA data sets were reformatted along the coronary vessel
path and compared with the corresponding x-ray angiogram.
Statistics
All data are expressed as mean±SD. Continuous variables
were compared with a 2-tailed paired Student's t test, with
significance as P
0.05.
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Results |
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TopAbstractIntroductionMethodsResultsDiscussionAppendix 1References |
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Scanning was completed without incident in all subjects. Total imaging time for each acquisition varied from 10 to 20 minutes depending on heart rate and navigator efficiency.
T2prep: Healthy Subjects
In Figure 6, the CNR impact of
T2prep is demonstrated between the ventricular cavity blood
and the myocardium. In the absence of T2prep (Figure 6A),
there is little contrast between the myocardium
and blood pool. With T2prep (Figure 6B), there is suppression of
myocardium, with improved LAD visualization.
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In Figure 7, a similar comparison is
shown for the LAD and the LCx. In addition to myocardial suppression,
T2prep also suppressed signal from the great cardiac vein (Figure 7B),
and fewer respiratory artifacts were observed (Figure 6B and Figure 7B and D). Overall, T2prep improved CNR
123% (P<0.001) between coronary blood and
myocardium (Table 1).
There was a trend toward improved CNR between arterial and
venous blood and a trend toward reduced SNR (Table 1).
Application of the T2prep did not adversely affect navigator
performance (Table 1).
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The use of T2prep allowed for a 33% improvement in LAD and LCx
vessel definition (P<0.001; Table 2). The objectively measured proximal
vessel diameter was not T2prep dependent. The high image quality of all
coronary scans allowed visualization of the entire LM and the
proximal and mid LAD (Figures 4 and 8, top) in all subjects. The visible
length of the LCx (Figure 8, bottom) was longer (121%;
P<0.003) with T2prep (Table 2), and there was a
trend toward longer visualization of the LAD (Table 2).
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Acquisition Window
Reduction of the acquisition window resulted in a smaller
improvement (11%; P<0.001) in LAD and LCx definition
(Table 2). Most notably, the LCx was longer (48%;
P<0.05) with the shorter (60 ms) acquisition window (Table 2).
There was also a trend (P<0.07) toward a longer
visible length of the LAD (Table 2) and a better CNR between
arterial and venous blood (Table 1). There was no
significant difference in CNR, SNR, or measured vessel diameter (Tables 1 and 2).
Patient Study
Good agreement between x-ray angiography and coronary 3D
MRA regarding vessel anatomy can be observed in a
representative sample shown in Figure 9. This case shows the potential of
coronary MRA to assess the more distal parts of the
coronary system. Muscle and fat suppression were sufficient for
good delineation of the mid LAD from myocardium and
epicardial fat. An example from a patient with diffuse coronary
disease is shown in Figure 10.
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Discussion |
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TopAbstractIntroductionMethodsResultsDiscussionAppendix 1References |
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A noninvasive method to evaluate the native coronary arteries would be a major clinical advance. In this objective study comparing free-breathing 3D coronary MRA with and without T2prep, we demonstrated that T2prep improved CNR and definition of the LAD and LCx but made no significant difference in visible LAD length. The latter was primarily influenced by imaging volume. In contrast, visualization of the LCx appeared to be related to its anatomic location. The improved visualization of the LCx with T2prep is likely due to improved suppression of myocardium and veins. As previously discussed by Brittain et al,7 T2prep should suppress deoxygenated venous blood (Figure 7B
) owing to its shorter T2. We observed a trend toward an
improved CNR between arterial and venous blood. This may be
particularly important, because the paths of the great cardiac vein and
LCx are quite close. This suppression might also be helpful for
individuals in whom the vein crosses the LAD (Figure 7A and 7B).
Coronary diameters were T2prep independent. T2prep also reduced
respiratory motion artifacts, likely owing to suppression of chest wall
muscle signal. Reduction of the acquisition window from 120 to 60 ms led to an improvement in LAD delineation. However, compared with T2prep, the absolute magnitude was small and came at the expense of a doubled scan time. This time might be better used to increase the volume coverage or use of averaging.
T2prep in combination with free-breathing coronary MRA resulted in quantitatively better definition of the LAD and LCx. Compared with previous studies,3 4 5 our findings are based on objective quantitative analyses of vessel-wall sharpness. Application of automated vessel-edge algorithms with a standardized vessel sharpness score might allow for more objective comparisons of different imaging strategies.
Clinical Considerations
T2prep 3D coronary MRA showed good agreement with
x-ray angiography for assessment of vessel anatomy as well as
CAD. Application of T2prep suppressed the signal from the
myocardium and therefore allowed for improved
blood-to-myocardium contrast. Both diffuse and focal
coronary disease could be visualized. The accuracy of the
methodology remains to be examined in large, multicenter studies.
With the introduction of intravascular contrast agents,24 25 the question arises whether T2prep would offer a synergistic effect. According to our preliminary experiences, such intravascular contrast agents reduce the differ-ential in T2 between blood and myocardium, thus decreasing the beneficial effect of the T2prep.
Technical Considerations
Navigator correction was used to compensate for respiratory
motion in the foot-to-head direction. The navigator was applied in the
vicinity of the LM with a constant correction factor. This study was
not intended to examine the impact of the correction factor. It is
likely that the correction factor for the more distal coronary
segments would be closer to 1.67.26
Conclusions
The combined approach of free-breathing navigator-gated and
slice-tracked 3D coronary MRA together with a T2prep and a
shorter acquisition window resulted in an improved CNR between
coronary blood and myocardium and thereby allowed
for better definition of the coronary vessels. The technique
has been successfully applied to healthy volunteers and a small patient
group. Visually assessed vessel anatomy as well as diffuse and
focal coronary artery disease correlated well with x-ray
angiographic findings. This approach offers the potential for
noninvasive assessment of the major coronary arteries.
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Footnotes |
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Reprint requests to René Botnar, PhD, Beth Israel Deaconess Medical Center, Cardiovascular Division, Cardiac MR, 330 Brookline Ave, Boston, MA 02215.
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Appendix 1 |
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TopAbstractIntroductionMethodsResultsDiscussionAppendix 1References |
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Vessel tracing and edge detection were performed on gray-scale images of the 3D raw data sets. The user defines the vessel of interest by drawing points
[k] along the vessel path, whereby k is the
index of each point. Each of these points is a vector, with a unity
direction 
[k] and a unity normal 
[k] vector defined
by Equation 2:
 | (2) |
The position of these points is then updated with the center of gravity
c[k], representing the vessel
centerline. The center of gravity was calculated along the intensity
profile I[k, 
], defined by the normal vector [k] and
a predefined window, w (Equation 3).
 | (3) |
 | (4) |
 |
The centerline point c[k] is then regridded with
cubic spline interpolation and equidistant spacing between adjacent
points 
cs[i] and cs[i+1]. The
index of the regridded centerline points cs is i.
The direction cs[i], the normal
cs[i] vectors, and the intensity profiles
Ics[i, ] are updated (Equations 2, and 4). After the centerline of the vessel has been defined, vessel
border detection is performed. The vessel border location is roughly
estimated with full-width half-maximum (FWHM) criteria (Equation 5).
 | (5) |
 | (6) |
The search window 
is increased until the criterion of
Equation 5 is fulfilled. The orientation of the vessel border
points FWHM±1[i] with respect to the
centerline is determined by the cross product (Equation 6).
The final vessel-border detection is done with the Deriche
edge-detection filter,27 a combination of a low-pass
filter for noise reduction and a high-pass filter for edge detection.
The filter parameter 
was empirically set to 2.5.
Applied on a step function, the Deriche filter returns the step size of
the function at the position of the step (edge). The vessel border is
identified as the maximum value of the edge profile in the interval
[0, pFWHM-1[i]] and [0,
pFWHM+1[i]]. The edge points are denoted
Deriche±1[i].
Vessel delineation (sharpness) is defined as the average edge value
along the entire vessel border (Equation 7).
 | (7) |
Deriche-1[i] and
Deriche+1[i] is defined as the vessel
diameter. Received December 27, 1998; revision received March 24, 1999; accepted April 9, 1999.
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T. Sommer, M. Hackenbroch, U. Hofer, A. Schmiedel, W. A. Willinek, S. Flacke, J. Gieseke, F. Traber, R. Fimmers, H. Litt, et al. Coronary MR Angiography at 3.0 T versus That at 1.5 T: Initial Results in Patients Suspected of Having Coronary Artery Disease Radiology, March 1, 2005; 234(3): 718 - 725. [Abstract] [Full Text] [PDF]
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A. M. Taylor, S. Dymarkowski, P. Hamaekers, R. Razavi, M. Gewillig, L. Mertens, and J. Bogaert MR Coronary Angiography and Late-Enhancement Myocardial MR in Children Who Underwent Arterial Switch Surgery for Transposition of Great Arteries Radiology, February 1, 2005; 234(2): 542 - 547. [Abstract] [Full Text] [PDF]
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D. J. Pennell, U. P. Sechtem, C. B. Higgins, W. J. Manning, G. M. Pohost, F. E. Rademakers, A. C. van Rossum, L. J. Shaw, and E. K. Yucel Clinical indications for cardiovascular magnetic resonance (CMR): Consensus Panel report Eur. Heart J., November 1, 2004; 25(21): 1940 - 1965. [Full Text] [PDF]
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 S. L. Gaynor, Y. Ishii, M. D. Diodato, S. M. Prasad, K. M. Barnett, N. R. Damiano, G. D. Byrd, S. A. Wickline, R. B. Schuessler, and R. J. Damiano Jr Successful Performance of Cox-Maze Procedure on Beating Heart Using Bipolar Radiofrequency Ablation: A Feasibility Study in Animals Ann. Thorac. Surg., November 1, 2004; 78(5): 1671 - 1677. [Abstract] [Full Text] [PDF]
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C. U. Herborn, M. Schmidt, O. Bruder, E. Nagel, K. Shamsi, and J. Barkhausen MR Coronary Angiography with SH L 643 A: Initial Experience in Patients with Coronary Artery Disease Radiology, November 1, 2004; 233(2): 567 - 573. [Abstract] [Full Text] [PDF]
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C. Jahnke, I. Paetsch, B. Schnackenburg, A. Bornstedt, R. Gebker, E. Fleck, and E. Nagel Coronary MR Angiography with Steady-State Free Precession: Individually Adapted Breath-hold Technique versus Free-breathing Technique Radiology, September 1, 2004; 232(3): 669 - 676. [Abstract] [Full Text] [PDF]
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E. Spuentrup, M. Katoh, A. Buecker, W. J. Manning, T. Schaeffter, T.-H. Nguyen, H. P. Kuhl, M. Stuber, R. M. Botnar, and R. W. Gunther Free-breathing 3D Steady-State Free Precession Coronary MR Angiography with Radial k-Space Sampling: Comparison with Cartesian k-Space Sampling and Cartesian Gradient-Echo Coronary MR Angiography--Pilot Study Radiology, May 1, 2004; 231(2): 581 - 586. [Abstract] [Full Text] [PDF]
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S. Mavrogeni, G. Papadopoulos, M. Douskou, S. Kaklis, I. Seimenis, P. Baras, P. Nikolaidou, C. Bakoula, E. Karanasios, A. Manginas, et al. Magnetic resonance angiography isequivalent to X-Ray coronary angiography for the evaluation of coronary arteries in kawasaki disease J. Am. Coll. Cardiol., February 18, 2004; 43(4): 649 - 652. [Abstract] [Full Text] [PDF]
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D. Maintz, F. C. Aepfelbacher, K. V. Kissinger, R. M. Botnar, P. G. Danias, W. Heindel, W. J. Manning, and M. Stuber Coronary MR Angiography: Comparison of Quantitative and Qualitative Data from Four Techniques Am. J. Roentgenol., February 1, 2004; 182(2): 515 - 521. [Abstract] [Full Text] [PDF]
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C. U. Herborn, J. Barkhausen, I. Paetsch, P. Hunold, M. Mahler, K. Shamsi, and E. Nagel Coronary Arteries: Contrast-enhanced MR Imaging with SH L 643A--Experience in 12 Volunteers Radiology, October 1, 2003; 229(1): 217 - 223. [Abstract] [Full Text] [PDF]
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M. S. Dirksen, H. J. Lamb, P. Kunz, P. Robert, C. Corot, and A. de Roos Improved MR Coronary Angiography with Use of a New Rapid Clearance Blood Pool Contrast Agent in Pigs Radiology, June 1, 2003; 227(3): 802 - 808. [Abstract] [Full Text] [PDF]
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S. Plein, S. Bulugahapitiya, T. R. Jones, G. J. Bainbridge, J. P. Ridgway, and M. U. Sivananthan Cardiac MR Imaging with External Respirator: Synchronizing Cardiac and Respiratory Motion—Feasibility Study Radiology, June 1, 2003; 227(3): 877 - 882. [Abstract] [Full Text] [PDF]
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R. M. McCarthy, S. M. Shea, V. S. Deshpande, J. D. Green, F. S. Pereles, J. C. Carr, J. P. Finn, and D. Li Coronary MR Angiography: True FISP Imaging Improved by Prolonging Breath Holds with Preoxygenation in Healthy Volunteers Radiology, April 1, 2003; 227(1): 283 - 288. [Abstract] [Full Text] [PDF]
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J. Bogaert, R. Kuzo, S. Dymarkowski, R. Beckers, J. Piessens, and F. E. Rademakers Coronary Artery Imaging with Real-time Navigator Three-dimensional Turbo-Field-Echo MR Coronary Angiography: Initial Experience Radiology, March 1, 2003; 226(3): 707 - 716. [Abstract] [Full Text] [PDF]
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S. Plein, T. R. Jones, J. P. Ridgway, and M. U. Sivananthan Three-Dimensional Coronary MR Angiography Performed with Subject-Specific Cardiac Acquisition Windows and Motion-Adapted Respiratory Gating Am. J. Roentgenol., February 1, 2003; 180(2): 505 - 512. [Abstract] [Full Text] [PDF]
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B. Giorgi, S. Dymarkowski, F. Maes, M. Kouwenhoven, and J. Bogaert Improved Visualization of Coronary Arteries Using a New Three-Dimensional Submillimeter MR Coronary Angiography Sequence with Balanced Gradients Am. J. Roentgenol., October 1, 2002; 179(4): 901 - 910. [Abstract] [Full Text] [PDF]
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W. Y. Kim, M. Stuber, P. Bornert, K. V. Kissinger, W. J. Manning, and R. M. Botnar Three-Dimensional Black-Blood Cardiac Magnetic Resonance Coronary Vessel Wall Imaging Detects Positive Arterial Remodeling in Patients With Nonsignificant Coronary Artery Disease Circulation, July 16, 2002; 106(3): 296 - 299. [Abstract] [Full Text] [PDF]
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 R. P. Choudhury, V. Fuster, J. J. Badimon, E. A. Fisher, and Z. A. Fayad MRI and Characterization of Atherosclerotic Plaque: Emerging Applications and Molecular Imaging Arterioscler Thromb Vasc Biol, July 1, 2002; 22(7): 1065 - 1074. [Abstract] [Full Text] [PDF]
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G. F. Greil, M. Stuber, R. M. Botnar, K. V. Kissinger, T. Geva, J. W. Newburger, W. J. Manning, and A. J. Powell Coronary Magnetic Resonance Angiography in Adolescents and Young Adults With Kawasaki Disease Circulation, February 26, 2002; 105(8): 908 - 911. [Abstract] [Full Text] [PDF]
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S. E. Langerak, H. W. Vliegen, A. de Roos, A. H. Zwinderman, J. W. Jukema, P. Kunz, H. J. Lamb, and E. E. van der Wall Detection of Vein Graft Disease Using High-Resolution Magnetic Resonance Angiography Circulation, January 22, 2002; 105(3): 328 - 333. [Abstract] [Full Text] [PDF]
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 W. Y. Kim, P. G. Danias, M. Stuber, S. D. Flamm, S. Plein, E. Nagel, S. E. Langerak, O. M. Weber, E. M. Pedersen, M. Schmidt, et al. Coronary Magnetic Resonance Angiography for the Detection of Coronary Stenoses N. Engl. J. Med., December 27, 2001; 345(26): 1863 - 1869. [Abstract] [Full Text] [PDF]
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 D. Pennell IMAGING TECHNIQUES: Cardiovascular magnetic resonance Heart, May 1, 2001; 85(5): 581 - 589. [Full Text]
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D. Li, J. C. Carr, S. M. Shea, J. Zheng, V. S. Deshpande, P. A. Wielopolski, and J. P. Finn Coronary Arteries: Magnetization-prepared Contrast-enhanced Three-dimensional Volume-targeted Breath-hold MR Angiography Radiology, April 1, 2001; 219(1): 270 - 277. [Abstract] [Full Text]
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M. Stuber, R. M. Botnar, K. V. Kissinger, and W. J. Manning Free-Breathing Black-Blood Coronary MR Angiography: Initial Results Radiology, April 1, 2001; 219(1): 278 - 283. [Abstract] [Full Text]
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D. Li, J. Zheng, and H.-J. Weinmann Contrast-enhanced MR Imaging of Coronary Arteries: Comparison of Intra- and Extravascular Contrast Agents in Swine Radiology, March 1, 2001; 218(3): 670 - 678. [Abstract] [Full Text]
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R. M. Botnar, M. Stuber, K. V. Kissinger, W. Y. Kim, E. Spuentrup, and W. J. Manning Noninvasive Coronary Vessel Wall and Plaque Imaging With Magnetic Resonance Imaging Circulation, November 21, 2000; 102(21): 2582 - 2587. [Abstract] [Full Text] [PDF]
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D. K. Sodickson, C. A. McKenzie, W. Li, S. Wolff, W. J. Manning, and R. R. Edelman Contrast-enhanced 3D MR Angiography with Simultaneous Acquisition of Spatial Harmonics: A Pilot Study Radiology, October 1, 2000; 217(1): 284 - 289. [Abstract] [Full Text]
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 K. Rajappan, N. G. Bellenger, L. Anderson, and D. J. Pennell The role of cardiovascular magnetic resonance in heart failure Eur J Heart Fail, September 1, 2000; 2(3): 241 - 252. [Abstract] [Full Text] [PDF]
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Z. A. Fayad, V. Fuster, J. T. Fallon, T. Jayasundera, S. G. Worthley, G. Helft, J. G. Aguinaldo, J. J. Badimon, and S. K. Sharma Noninvasive In Vivo Human Coronary Artery Lumen and Wall Imaging Using Black-Blood Magnetic Resonance Imaging Circulation, August 1, 2000; 102(5): 506 - 510. [Abstract] [Full Text] [PDF]
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 A. C. Fox and R. I. Levin Ruptured Plaques and Leaking Cells: Cost-Effectiveness in the Diagnosis of Acute Coronary Syndromes Ann Intern Med, December 21, 1999; 131(12): 968 - 970. [Full Text] [PDF]
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M. Stuber, R. M. Botnar, P. G. Danias, D. K. Sodickson, K. V. Kissinger, M. Van Cauteren, J. De Becker, and W. J. Manning Double-oblique free-breathing high resolution three-dimensional coronary magnetic resonance angiography J. Am. Coll. Cardiol., August 1, 1999; 34(2): 524 - 531. [Abstract] [Full Text] [PDF]
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E. Spuentrup, A. Ruebben, T. Schaeffter, W. J. Manning, R. W. Gunther, and A. Buecker Magnetic Resonance-Guided Coronary Artery Stent Placement in a Swine Model Circulation, February 19, 2002; 105(7): 874 - 879. [Abstract] [Full Text] [PDF]
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