SHAPE Society

1. Editorial Slides
VP Watch, February 20, 2002, Volume 2, Issue 7
MRI Guided Angioplasty and Stenting; How Far
Away Are We?

2.  Currently, x-ray coronary angiography is used both
for the detection of the coronary artery disease and
for guidance of treatment (angioplasty and stent
deployment).
 Cardiac MRI and coronary MRA are very close to
become the standard of care for diagnosis of
ischemic heart disease. However the role of MRI in
guidance of treatment and interventional
cardiology has not received much attention.

3.  In 1997, Buecker and others successfully placed a
catheter into the left or right sacral artery in pigs with use
of an open 1.5-T magnetic resonance (MR) imager and
a tracking catheter. 1
 Manke, and colleagues showed that MR imaging–guided
stent placement in iliac arteries is feasible in select
patients. 2
 In another study Buecker and his colleagues determined
that real-time radial MR scanning is able to show correct
position of the stent in iliac arteries of pigs.3

4.  As highlighted in VP Watch of this week,
Spuentrup, Manning, Buecker, and colleagues
presented the first MR-guided coronary artery stent
placement in pigs. 4
 They showed that real-time MR imaging allows for
high-quality coronary MR fluoroscopy without
motion artifacts. 4

5.  Spuentrup and his colleagues performed MR-
guided stent placement using a newly-developed
interactive real-time radial steady-state free
precession (rSSFP) imaging sequence during free
breathing and without cardiac triggering. 4
 Using guidewire in 3D SSFP coronary MRA images
displayed a small artifact whereas, the mounted
stent resulted in a larger artifact allowing for stent
localization. 4

6.  In this study, Spuentrup and colleagues placed 10
of 11 coronary stents correctly in pigs under MR
guidance. 4
 They could detect one case of stent dislocation
during real-time MR imaging. 4
 SSFP MR fluoroscopy shows a high contrast of the
coronary artery lumen without injection of an
exogenous contrast agent. 4

7.  MR-guided coronary stent imaging has following
advantages against x-ray angiography:
 Can measure myocardial viability 5
 Shows coronary artery vessel wall/plaque
morphology 6,7
 Does not need ionizing radiation
 No heavy metal contrast agent needed
 Superior 3D anatomical image
 Allows continuous visualization of coronary
artery and surrounding tissues without
additional guiding catheters.
 …

8.  Technical challenges of MR-guided coronary
stent are as following:
a. Substantial motion artifacts originating from
respiratory and cardiac cycles. 8
b. Small size and the tortuous anatomy of
coronary arteries. 9

9. Conclusion:
I. Real-time MR-guided stent placement is now feasible
in coronary artery of pigs.
II. The presented real-time MR imaging sequence
reliably allows for high-quality coronary MR
fluoroscopy without cardiac motion artifacts.
III. Passive visualization of the guidewire and stent
suffices for real-time monitoring of the procedure.

10. Questions:
I. What are the major barriers in the way of MRI to
replace X-ray angiography for interventional
cardiologists?
II. If MR can be of grade added value to the current cat
labs, would marriage of X-ray and MR (X-MR) be
meaningful? Can this marriage survive through cost
effectiveness challenge?

11. Suggestion:
VP.org Editorial Suggestion:
- Please email your thoughts to:
Discussion-Group@VP.org or DG@VP.org

12. 1) Bakker CJ, Smits HF, Bos C et al. MR-guided balloon angioplasty: in vitro demonstration of the potential
of MRI for guiding, monitoring, and evaluating endovascular interventions. J Magn Reson Imaging 1998;
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2) Manke C, Nitz WR, Djavidani B, et al. MR imaging-guided stent placement in iliac arterial stenoses: a
feasibility study. Radiology. 2001; 219: 527–534.
3) Buecker A, Neuerburg JM, Adam GB, et al. Real-time MR fluoroscopy for MR-guided iliac artery stent
placement. J Magn Reson Imaging. 2000; 12: 616–622. Elmar
4) Spuentrup, Alexander Ruebben, Tobias Schaeffter, Warren J. Manning, Rolf W. Günther, and Arno
Buecker ; Magnetic Resonance–Guided Coronary Artery Stent Placement in a Swine Model;Circulation
2002 105: 874 - 879; published online before print January 14 2002, 10.1161/hc0702.104165.
5) Kim RJ, Wu E, Rafael A, et al. The use of contrast-enhanced magnetic resonance imaging to identify
reversible myocardial dysfunction. N Engl J Med. 2000; 343: 1445–1453
6) a Fayad ZA, Fuster V, Fallon JT, et al. Noninvasive in vivo human coronary artery lumen and wall
imaging using black-blood magnetic resonance imaging. Circulation. 2000; 102: 506–510
7) aBotnar RM, Stuber M, Kissinger KV, et al. Noninvasive coronary vessel wall and plaque imaging with
magnetic resonance imaging. Circulation. 2000; 102: 2582–2587
8) Lardo AC, McVeigh ER, Jumrussirikul P, et al. Visualization and temporal/spatial characterization of
cardiac radiofrequency ablation lesions using magnetic resonance imaging. Circulation. 2000; 102: 698–
705
9) Dodge JT Jr, Brown BG, Bolson EL, et al. Lumen diameter of normal human coronary arteries: influence
of age, sex, anatomic variation, and left ventricular hypertrophy or dilation. Circulation. 1992; 86: 232–
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References