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Throm bosis, and Vascular Biology. 1997;17:3626-3632
(Arteriosclerosis, Thrombosis, and Vascular Biology. 1997;17:3626-3632.)
© 1997 American Heart Association, Inc.
This Art icle
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A le r t m e w he n e Le t t e r s a r e post e d
A le r t m e if a cor r e ct ion is post e d
Intravascular Magnetic Resonance
Imaging of Aortic Atherosclerotic Plaque
Composition
Luis C. L. Correia; Ergin Atalar; Mark D. Kelemen; Ogan Ocali;
Grover M. Hutchins; Jerome L. Fleg; Gary Gerstenblith;
Elias A. Zerhouni; ; Joao A. C. Lima
Correspondence to Joao A.C. Lima, MD, Cardiology Division, Blalock 569, The
Johns Hopkins Hospital, 600 N Wolfe St, Baltimore, MD 21287-6568. E-mail
lucorrei@welchlink.welch.jhu.edu.
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PubMed
P ubMe d Cit a t ion
A r t icle s by Cor r e ia , L. C. L.
A r t icle s by Lim a , J. A . C.
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Me dline P lus He a lt h I nf or m a t ion
MRI Sca n s
Abstract
Top
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Abstract
Abstract Magnetic resonance imaging (MRI) may be an excellent tool to define atherosclerotic
Introduction
plaque composition, but surface MRI (SMRI) suffers from a low signal-to-noise ratio and low
Methods
Results
resolution of arterial images. Intravascular MRI (IVMRI) represents a potential solution for
Discussion
acquiring high-quality in vivo images of atherosclerotic plaques. Isolated segments of 11
References
thoracic human aortas obtained at autopsy were imaged by IVMRI using an intravascular
receiver catheter coil designed and built at our institution. Images obtained by IVMRI were compared with
corresponding images obtained by SMRI and with histopathological aortic cross sections. The intensity of intimal
thickness and plaque components was graded by IVMRI and histopathology using a score of 1 for mild, 2 for
moderate, and 3 for severe intensity. IVMRI had an agreement of 75% with histopathology in fibrous cap
grading (37.5% expected, =0.60, P<0.001) and of 74% in necrotic core grading (39% expected, =0.57,
P<0.001). Intraplaque calcification was correctly graded by IVMRI in six of the eight plaques in which
histopathology recognized calcium. The analysis of intimal thickness showed 80% agreement between IVMRI
and histopathology (52% expected, =0.59, P<0.001). IVMRI image features were similar to those of SMRI.
In addition, IVMRI accurately determined atherosclerotic plaque size in comparison with histopathology and
SMRI (slope=1.25 cm2, r=0.99, P<0.001 for luminal area by IVMRI vs histopathology; slope=0.97 cm2,
r=0.996, P<0.001 for luminal area by IVMRI vs SMRI). IVMRI has the potential to provide important
prognostic information in patients with atherosclerosis because of its ability to accurately assess both plaque
composition and size.
Key Words: intravascular magnetic resonance imaging • atherosclerotic plaque • human aorta
Introduction
Top
Abstract
The assessment of atherosclerotic plaque composition has significant prognostic implications
Introduction
for patients with atherosclerosis, because it is one determinant of the susceptibility to plaque
Methods
disruption and resultant clinical outcomes in patients with atherosclerotic disease. The amount
Results
Discussion
of intraplaque lipid content and the thickness of the fibrous cap are closely related to the
References
vulnerability of a given plaque to rupture,1 2 with resultant untoward clinical outcomes including
unstable angina, myocardial infarction, and stroke. Other intraplaque elements may also contribute to plaque
disruption. The extent and location of intraplaque calcification are also related to atherosclerotic plaque
vulnerability.3 4 5 Hemorrhage resulting from rupture of vasa vasorum within the plaque, causing increased
intraplaque pressure, may also be a responsible trigger.6
Current clinical magnetic resonance techniques do not provide a sufficient signal-to-noise ratio to achieve highresolution arterial images in vivo because of the distance between the imaging coil and the vessel imaged. MRI
has been shown to demonstrate plaque structure in detail using image contrast from different intraplaque
components.7 8 9 10 However, these studies applied a surface coil directly to the vessel, which is not feasible in
vivo. A practical solution for this problem is to acquire the image from inside the vessel using an intravascular
catheter. The first successful attempt at using intravascular magnetic resonance was performed by Kantor et al11
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to obtain nuclear magnetic resonance spectroscopy from the right and left ventricles of canine hearts. The same
principle was later used as an imaging technique in the study of atherosclerotic plaques from inside large vessels,
both ex vivo12 13 14 and in vivo15 16 with animal models, demonstrating that the signal-to-noise ratio can be
improved and that high-resolution images of arteries and veins can be obtained by using an intravascular catheter
coil. It should also be noted that IVMRI of small arteries in vivo is feasible, as illustrated by our experimental
studies in the rabbit model.17
Although the ability of IVMRI to provide good-quality images has been demonstrated, detailed determination of
plaque composition and size by IVMRI has not been attempted. In the present study, an intravascular coil was
used to determine plaque composition and size in isolated human aortae.
Methods
Experimental Protocol
Aortic arterial segments were removed from 11 individuals aged 44 to 85 years (mean±SD,
65±15 years) at the time of autopsy. Approximately 10 cm of thoracic aorta was excised, and
both ends of the vessel were occluded with a large cork. The caudal cork had an orifice to
allow introduction of the IVMRI catheter. The aorta was taped inside a plastic container filled
with water at room temperature.
Top
Abstract
Introduction
Methods
Results
Discussion
References
MRI Protocol
The experiments were performed on a GE Signa 1.5 T scanner. The receiver catheter coil, designed and built at
our institution, was long, narrow, and flexible. The coil was a segment of standard wire with conductors
(diameter=3 mm or 9F) shorted at one end and with the other end used as the coil terminal. It was tuned with
small, fixed ceramic chip capacitors (1.5x1.5x1.4 mm) sealed with plastic dip. A 50- coaxial cable was used to
transmit the magnetic resonance signal to the preamplifier. For decoupling the transmitter (body) coil and the
receiver (catheter) coil, a PIN diode at the end of the coaxial cable turned the coil off during radiofrequency
transmission via a DC pulse supplied by the scanner. The catheter coil was described in detail in a previous
article.14
The MRI standard protocol lasted 30 minutes and consisted of IVMRI and SMRI axial images of the artery.
The plastic container with aorta and the coil inside was placed in the scanner and aligned with the main magnetic
field. After coronal scout images, axial images were obtained using the following spin-echo imaging protocol:
image matrix, 256x256; pixel dimensions, 0.27x0.27 mm; slice thickness, 3 mm; TR, 1500milliseconds; two
echoes; TE, 17 and 80 milliseconds; acquisition time, 12 minutes, 51 seconds; 2 NEX; and 14 slices. Proton
density (TR=1500 milliseconds/TE=17 milliseconds) and T2-weighted (TR=1500 milliseconds/TE=80
milliseconds) were the two types of images used. Intravascular images were acquired from the catheter coil
placed inside the vessel along its length and without moving it. After IVMRI, the catheter coil was then removed
and the surface coil placed under the plastic container for SMRI. SMRI images were obtained by placing a 75mm-diameter surface coil directly under the plastic container, using exactly the same parameters as used to
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acquire the intravascular images.
Histopathological Methods
After MRI acquisition, the aorta was placed in 4% formaldehyde solution for at least 48 hours. The fixed aorta
was cut into cross-sectional slices that matched the location (every 5 mm) of the images acquired by IVMRI.
The aortic cross-sectional slices were stained with Oil Red O, embedded in paraffin, and cut into sections 5 µm
thick, which were processed for hematoxylin-eosin, Verhoeff-van Gieson, and Masson staining.
Histopathology was used for two specific purposes: plaque composition analysis and plaque size measurements.
Photomicrographs of the hematoxylin-eosin—stained sections of were digitized onto compact discs and
analyzed using National Institutes of Health Image software to determine the degree of aortic atherosclerotic
stenosis. Verhoeff-van Gieson and Masson stains were performed using standard methods to enable recognition
of elastic components and to better differentiate the aortic wall layers in the plaque composition analysis.
Image Data Analysis
Arterial images were acquired by IVMRI and SMRI every 5 mm from the caudal to the cranial end of the aortic
segment. Histopathological sections were also obtained every 5 mm of the aorta. In this manner, the sites imaged
by the MRI methods corresponded to the location of histopathological cross sections. Anatomic landmarks were
also used to carefully fine-tune the match between IVMRI and histopathology cross sections in the
atherosclerotic plaque composition analysis.
The plaque composition analysis consisted of two parts. In the first, IVMRI images were compared with
histopathology slides, and image features of individual plaque components and arterial wall layers by IVMRI
were determined. Image characteristics were also expressed in terms of T2 relaxation times for each component.
In the second part, the ability of IVMRI to estimate intimal thickening, fibrous cap thickness, necrotic core size,
and the extent of intraplaque calcification was evaluated by grading these structures (1=mild, 2=moderate,
3=severe) and comparing these scores with those obtained from histopathological slides carefully matched to the
MRI images. One investigator graded the severity of the various components of the atherosclerotic plaque by
histopathology and another investigator by IVMRI. Each was blinded to the results of the other modality.
In the plaque size analysis, MRI and histopathology measurements were compared by careful registration of
corresponding images as described above. CSA was defined as the total area circumscribed by the intima/media
or plaque/media interface, and ILA was defined as the total area circumscribed by the intima/lumen interface.
The degree of atherosclerotic stenosis was calculated as (CSA-ILA)/CSA. The measurements were performed
by two different investigators. The arithmetic mean of the two measurements of ILA or CSA performed by
different investigators at each aortic site was taken as the final value. Interobserver variation was also calculated.
Statistical Analysis
The test was used to assess agreement between the IVMRI and histopathology scores utilized to evaluate
plaque composition and intimal thickening. One-way analysis of variance with Bonferroni correction was used to
compare T2 measurements from different plaque and arterial wall components, which were expressed as the
mean±SE. In the atherosclerotic plaque size analysis, agreement among the methods was assessed by limits of
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agreement as illustrated on Bland-Altman plots, and simple linear regression was used to correlate quantitative
measurements obtained by IVMRI, SMRI, and histopathology. The linear regression equation was forced
through the origin (0,0) to identify differences in measurements based on the slope value. Limits of agreement
were also used to assess interobserver variation of IVMRI and SMRI. For all analyses a value of P<0.05 was
required for statistical significance.
Results
Top
Aortic Arterial Wall
Abstract
Introduction
The best contrast between arterial layers was achieved by T2-weighted images. IVMRI
Methods
identified the aortic intima as a very thin, dark membrane, better recognized when thickened
Results
Discussion
and identified as a low signal inner layer on the T2-weighted images (Fig 1 ). The arterial
References
media could be systematically recognized by IVMRI and appeared on T2-weighted images as
a high-signal (bright) layer. The arterial adventitia corresponded to a low-signal (dark) outer layer and was also
easily recognized because of its contrast with the medium.
Figure 1. T2-weighted IVMRI axial image of aorta showing a site in
which intimal thickening involving a segment of the arterial wall
circumference (A, arrow) correlates with intimal thickening by
histopathology (B). Panel C corresponds to the region without
significant intimal changes by histopathology.
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The intima and adventitia had low T2 values (mean±SE) (intima=46.7±2 milliseconds, n=33; adventitia=52.2±9
milliseconds, n=20), while the media had high T2 values (mean=91.2±10 milliseconds, n=60) (Fig 2 ). T2
values from the arterial media were statistically different (P<0.05) from the intima and adventitia values.
Figure 2. Means±SEs of T2 measurements from atherosclerotic
plaque and arterial wall components. Thickened intima, fibrous cap
(FC), and aortic adventitia have low T2 values, while the necrotic
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core (NC) and aortic media appear bright in T2-weighted images
because of their high T2 relaxation times. The P value refers to the
overall difference obtained by one-way analysis of variance.
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Atherosclerotic Plaque Components
The fibrous cap was recognized as a dark structure covering the atherosclerotic plaque, while the necrotic core
appeared as a bright nucleus under the fibrous cap (Fig 3 ). The fibrous cap had a low T2 value (mean
±SE=49.2±4 milliseconds, n=16), while the highest T2 values were obtained from the necrotic core and the
medial elastic layer (75.6±9 milliseconds, n=29, and 91.2±10 milliseconds, n=60, respectively). Both T2 values
from necrotic core and media were significantly greater (P<0.05) than the ones from the adventitia, fibrous cap,
and intima reported above (Fig 2 ). There was no statistical difference between media and necrotic core T2
values.
Figure 3. Axial T2-weighted IVMRI image of aortic cross section with
atherosclerotic plaque (A, arrow). The IVMRI image shows a dark region on
top of the plaque, which corresponds to the fibrous cap shown by
histopathology (B, Masson stain). The region inside the plaque, the necrotic
core, is bright by IVMRI.
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Intraplaque calcification appeared as a signal void on IVMRI, because calcified regions have low proton
densities (Fig 4 , A). All intraplaque features obtained by MRI performed with a surface coil applied to the
vessel (Fig 4 , B) were similar to the IVMRI features described above.
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Figure 4. These proton-density–weighted images exhibit a large
dark region (arrow) that correlates with a zone of significant
intraplaque calcification shown by histopathology (C, Masson
stain). A, IVMRI. B, The same cross section imaged by SMRI.
This figure also illustrates the similarity between the IVMRI and
SMRI images obtained with identical parameters.
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The ability of IVMRI to estimate the magnitude of individual atherosclerotic plaque components and arterial
intimal thickness was also compared with that of histopathology using a score of 1 to 3 (1=mild, 2=moderate,
3=severe). Sixty IVMRI-histopathology–matched cross-sectional images were analyzed. The analysis of these
images revealed 24 atherosclerotic plaques whose composition was compared by IVMRI and histopathology.
IVMRI recognized a fibrous cap in 20 of the 24 plaques in which this structure was identified by histopathology.
The 20 fibrous caps were graded by both methods, and the agreement between the two was 75% (37.5%
expected, =0.60, P<0.001).
A necrotic core was recognized by histopathology in 23 of the 24 plaques evaluated. IVMRI detected this
finding in all 23 plaques but incorrectly recognized a necrotic core in one in which this feature was not recognized
by histopathology. In grading the extent of intraplaque lipid accumulation, histopathology and IVMRI had an
agreement of 74% (39% expected, =0.57, P<0.001).
Intraplaque calcification was recognized by histopathology in 8 of the 24 plaques analyzed. IVMRI correctly
identified such calcifications in 7 of them. In addition, IVMRI correctly graded calcification in all cases compared
with histopathology: 6 as severe and 1 as moderate calcification.
Histopathology showed intimal thickening in 46 of the 48 sections analyzed for this purpose. IVMRI correctly
recognized thickening in all 46 and incorrectly recognized it as present in one of the two cases where it was not
recognized by histopathology. analysis showed 80% agreement between IVMRI and histopathology grades of
thickness (52% expected, =0.59, P<0.001).
Atherosclerotic Plaque Size Determination
Interobserver variations in SMRI and IVMRI measurements were assessed by limits of agreement. The means
of the differences between the two observers' measurements of CSA and ILA by IVMRI were -0.14 cm2 and 0.03 cm2, while the SDs of the differences were 0.15 cm2 and 0.08 cm2, respectively. The means of the
differences between the two observers' measurements of CSA and ILA by SMRI were -0.12 cm2 and -0.02
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Intravascular Magnetic Resonance Im…
while the SDs of the differences were 0.13 cm2 and 0.09 cm2, respectively.
Aortic atherosclerotic plaque size measured by IVMRI was compared with measurements derived from SMRI
images and histopathology. Table 1 summarizes limits of agreement analysis of the comparison between
IVMRI and SMRI, showing a high level of agreement. The SDs of the differences between IVMRI and SMRI
measurements of CSA and ILA were 0.22 cm2 and 0.25 cm2, respectively. Linear regression analysis was
performed between SMRI and IVMRI for CSA (slope=0.97, r=0.998, P<0.001), ILA (slope=0.97, r=0.996,
P<0.001, Fig 5 , A), and percent stenosis (slope=0.98, r=0.94, P<0.001).
View this table: Table 1. Agreement of IVMRI and SMRI in the Measurement of CSA and ILA
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Figure 5. A, Scatter plot of luminal measures by IVMRI and
SMRI. Linear regression analysis demonstrates a strong
correlation between these methods. B, Scatter plot of luminal
measures by IVMRI and histopathology. Simple linear regression
also demonstrated a strong correlation between these two
methods.
Table 2 summarizes limits of agreement analysis of the comparison between IVMRI and histopathology,
showing that absolute values of CSA and ILA were systematically lower by histopathology than by IVMRI. The
SDs of the differences between IVMRI and histopathology measurements of CSA and ILA were 0.40 cm2 and
0.36 cm2, respectively, higher than in the comparison with SMRI. This discrepancy was caused by the staining
process required for histopathological examination, which causes systematic shape changes and shrinkage of
aortic tissue.10 Slope values obtained by linear regression forcing the analysis through zero indicates that IVMRI
measures of CSA (slope=1.26, r=0.99, P<0.001) and ILA (slope=1.25, r=0.99, P<0.001, Fig 5 , B) were
26% and 25% greater than the histopathology measures, respectively. Percent stenosis analysis showed that the
slope=0.94, r=0.90, and P<0.001.
View this table: Table 2. Agreement of IVMRI and Histopathology in the Measurement of CSA and
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Discussion
Our study demonstrates the ability of IVMRI to characterize atherosclerotic plaque
composition, revealing a significant advantage of this method over currently used arterial
imaging techniques. We also found that atherosclerotic burden in terms of plaque size can be
accurately quantified by IVMRI.
Top
Abstract
Introduction
Methods
Results
Discussion
References
Although prior studies7 8 9 10 have indicated that MRI obtained with a surface coil directly
applied to the vessel provides detailed characterization of atherosclerotic plaques, the distance between coil and
vessel with this technique is too large, except for superficial arteries,18 to achieve high-resolution images in vivo.
In the present study, we used an intravascular catheter receiver coil,12 13 14 15 16 17 which represents a practical
solution for achieving detailed arterial imaging in vivo, to differentiate fibrous cap from lipid core within an
atherosclerotic plaque. By using a scoring system to estimate the extent of abnormality, we graded intimal
thickness and intraplaque components by IVMRI and demonstrated a high level of agreement with
histopathology.
We observed that the fibrous cap appears as a short T2 plaque component and the necrotic core as a long T2
plaque component, in agreement with the findings of Yuan et al.7 Conversely, Martin et al9 reported the fibrous
cap to have a long T2 and the necrotic core a short T2 plaque component. As discussed by Berr et al,19 the
appearance of intraplaque lipids in MRI images depends on their physical state, which can vary with factors such
as temperature, age of the plaque, and time of storage. Also, the composition of the fibrous cap, particularly the
amount of collagen, influences the characteristics of the images. In addition, differences in pulse sequences, field
strength, and other image parameters may explain differences in image contrast.
The potential limitations of this data also merit consideration. The fixation process should ideally have been
performed under systemic pressure applied to the vessel to avoid changes in dimensions. To assess the effect of
our fixation process on vessel dimensions, we imaged, after fixation, 7 of the 11 aortae (a total of 56 segments)
by surface MRI and compared these dimensions with the ones from surface MRI before fixation and
histopathology. We concluded that, in our experiments, the changes in vessel dimensions by the histological
process occurred mainly after the fixation phase, because measurements obtained by SRMI before fixation were
not different than the ones obtained after fixation. However, there was a clear difference between measurements
obtained by SMRI after fixation and histopathology. Therefore, the fact that fixation was performed without
pressurization does not significantly decrease the precision of our measurements.
The matching between MRI images and histopathology sections based on metric criteria is limited, because final
histopathology paraffin sections were 5 µm thick, while MRI slices were 3 mm thick. To obtain more precise
matching for the qualitative analysis, the images were visually compared, and anatomic landmarks were used to
check the matches.
The 15-minute acquisition time reported in our methods is relatively long, because we used spin-echo as a pulse
sequence. Fast pulse sequences, such as fast spin-echo, GRASS, and echo-planar could have beenused, which
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would have optimized acquisition time without decreasing image quality. For example, our group used spoiled
GRASS to acquire IVMRI of rabbit aortae in vivo.17
Because fibrous cap thickness and lipid core size represent the main factors that determine plaque vulnerability
to rupture,1 2 it may be possible to use the IVMRI technique to image coronary arteries in patients with ischemic
heart disease, thus providing prognostic information that may be of more value than merely the number of lesions
and degree of luminal obstruction, as currently detected by angiography. In addition, the extent of intraplaque
calcification3 4 5 and hemorrhage6 may also determine the evolution of atherosclerotic plaques, and IVMRI may
also be able to recognize and characterize both of these plaque alterations.
The current most commonly used method to evaluate atherosclerotic plaques, x-ray angiography, has the ability
to demonstrate plaque site and degree of stenosis but is not able to accurately assess the predisposition of a
given plaque to rupture. The reason is the limited capability to determine plaque composition, because this
method does not provide direct visualization of the arterial wall. Angiography also has limitations in quantifying
plaque size, because it provides images only of the arterial lumen. Thus, plaque stenosis is commonly
underestimated if adjacent arterial segments are also involved with disease or when compensatory dilatation of
an involved arterial segment is present.20 21 Percutaneous transluminal angioscopy, which provides direct visual
access to the arterial endothelial surface, appears to be more sensitive than x-ray angiography in detecting the
degree of luminal stenosis but can examine only the surface of the lesion, therefore providing limited information
on plaque composition.22 Intravascular ultrasound has been extensively used in clinical practice and clinical
investigation to characterize atherosclerosis. It is more precise than x-ray angiography in quantifying
atherosclerotic plaque size but is limited in the evaluation of plaque composition because of poor contrast
resolution between different intraplaque components.23 24
MRI was originally developed to study the brain and static body organs because it relied upon averaging signals
from a large number of radiofrequency excitations over time. Recently, however, the development of fast imaging
technology25 26 to study the cardiovascular system has made MRI a powerful tool for clinical investigation.27 28
29 30 31 The potential of integrating recent MRI developments with open magnets, which are designed to allow
invasive procedures guided by MRI, creates the possibility of using IVMRI in humans to study atherosclerotic
disease. In this regard, a loopless catheter antenna less than 2.5F in diameter has been developed17 that might be
used to image coronary arteries. This catheter antenna has been tested in vivo to acquire images of rabbit aortae,
which are slightly larger in diameter than human coronary arteries (Fig 6 ).
Figure 6. In vivo intravascular cross-sectional image of normal
rabbit aorta. The vessel on the bottom, arrow, corresponds to the
abdominal aorta, and the vessel on the top is the inferior vena
cava. Pulse sequence was a fast spoiled GRASS, utilizing a TR of
9.1 milliseconds; TE, 2.8 ms; image matrix, 256x96; slice
thickness, 3 mm; field of view, 4 cm; and NEX, 8. Acquisition time
with a heart rate of 178 beats/min was 2:09 minutes.
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In conclusion, IVMRI provides detailed characterization of intraplaque components, including the extent of
intraplaque lipid accumulation and fibrous cap thickness. We believe this new IVMRI technique has the potential
to provide prognostic information as well as to assess the response to different therapeutic interventions in
patients with atherosclerotic disease.
Selected Abbreviations and Acronyms
CSA
= cross-sectional area
ILA
= intraluminal area
IVMRI = intravascular magnetic resonance imaging
MRI
= magnetic resonance imaging
NEX
= number of excitations
SMRI = surface magnetic resonance imaging
TE
= echo time
TR
= repetition time
Acknowledgments
This work was supported by a Whitaker Foundation biomedical research grant, Grant-in-Aid 92–10-26–01
from the American Heart Association, and Grant RO1-HL-43722 from the National Heart, Lung, and Blood
Institute, National Institutes of Health. Special thanks to Mary McAllister for her help in manuscript preparation,
to Bradley D. Bolster, Jr, for providing the animal in vivo image, and to Dr James Tonascia for his crucial help
with the statistical analysis.
Received February 14, 1997; accepted September 18, 1997.
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References
1. Fuster V, Badimon L, Badimon JJ, Chesebro JH. The pathogenesis of coronary artery
disease and the acute coronary syndromes (first of two parts). N Engl J Med..
1992;326:242–250.[Medline] [Order article via Infotrieve]
2. Falk E, Shah PK, Fuster V. Coronary plaque disruption. Circulation.. 1995;92:657–
671.[Free Full Text]
Top
Abstract
Introduction
Methods
Results
Discussion
References
3. Demer L. Effect of calcification on in vivo mechanical response of rabbit arteries to balloon dilatation.
Circulation.. 1991;83:2083–2093.[Abstract/Free Full Text]
4. Margolis J, Chen J, Kong Y, Peter R, Behar V, Kisslo J. The diagnostic and prognostic significance of
coronary artery calcification. Radiology.. 1980;137:609–616.[Abstract/Free Full Text]
5. Detrano R, Hsiai T, Wang S, et al. Prognostic value of coronary calcification and angiographic stenoses in
patients undergoing coronary angiography. J Am Coll Cardiol.. 1996;27:285–290.[Abstract]
6. Barger AC, Beeuwkes R III. Rupture of coronary vasa vasorum as a trigger of acute myocardial infarction.
Am J Cardiol.. 1990;66:41G–43G.[Medline] [Order article via Infotrieve]
7. Yuan C, Tsuruda JS, Beach KN, et al. Techniques for high-resolution MR imaging of atherosclerotic plaque.
J Magn Reson Imaging.. 1994;4:43–49.[Medline] [Order article via Infotrieve]
8. Merickel MB, Berr S, Spetz K, et al. Non-invasive evaluation of atherosclerosis utilizing MRI and image
analysis. Arterioscler Thromb.. 1993;13:1180–1186.[Abstract/Free Full Text]
9. Martin AJ, Gotlieb AI, Henkelman RM. High-resolution MR imaging of human arteries. J Magn Reson
Imaging.. 1995;5:93–100.[Medline] [Order article via Infotrieve]
10. Pearlman JD, Southern JF, Ackerman JL. Nuclear magnetic resonance microscopy of atheroma in human
coronary arteries. Angiology.. 1991;42:726–733.
11. Kantor HL, Briggs RW, Balaban RS. In vivo 31 P nuclear magnetic resonance measurements in canine heart
using a catheter-coil. Circ Res.. 1984;55:261–266.[Abstract/Free Full Text]
12. Martin AJ, Plewes DB, Henkelman RM. MR imaging of blood vessel with an intravascular coil. J Magn
Reson Imaging.. 1992;2:421–429.[Medline] [Order article via Infotrieve]
13. Kandarpa K, Jakab P, Patz S, Schoen FJ, Jolesz FA. Prototype miniature endoluminal MR imaging
catheter. J Vasc Interv Radiol.. 1993;4:419–427.[Medline] [Order article via Infotrieve]
14. Atalar E, Bottomley PA, Ocali O, et al. High resolution intravascular MRI and MRS using a catheter
receiver coil. Magn Reson Med.. 1996;36:596–605.[Medline] [Order article via Infotrieve]
15. Martin AJ, Henkelman RM. Intravascular MR imaging in a porcine animal model. Magn Reson Med..
1994;32:224–229.[Medline] [Order article via Infotrieve]
atvb.ahajournals.org/ cgi/ …/ 3626
12/ 18
2/ 23/ 2011
Intravascular Magnetic Resonance Im…
16. Hurst GC, Hua J, Duerk JL, Cohen AM. Intravascular (catheter) NMR receiver probe: preliminary design
analysis and application to canine iliofemoral imaging. Magn Reson Med.. 1992;24:343–357.[Medline] [Order
article via Infotrieve]
17. Ocali O, Atalar E. Intravascular magnetic resonance imaging using a loopless catheter antenna. Magn Reson
Med.. 1997;37:112–118.[Medline] [Order article via Infotrieve]
18. Toussaint JF, LaMuraglia GM, Southern JF, Fuster V, Kantor HL. Magnetic resonance images lipid,
fibrous, calcified, hemorrhagic, and thrombotic components of human atherosclerosis in vivo. Circulation..
1996;94:932–938.[Abstract/Free Full Text]
19. Berr SS, Brookeman, JR. On MR imaging of atheromatous lipids in human arteries. J Magn Reson
Imaging.. 1995;5:373–374.[Medline] [Order article via Infotrieve]
20. Thomas AC, Davies MJ, Dilly S, Dilly N, Franc F. Potential errors in the estimation of coronary arterial
stenosis from clinical arteriography with reference to the shape of the coronary arterial lumen. Br Heart J..
1986;55:129–139.[Abstract/Free Full Text]
21. Glagov S, Weisenberg E, Zarins CK, Stankunavicius R, Kolettis GJ. Compensatory enlargement of human
atherosclerotic coronary arteries. N Engl J Med.. 1987;316:1371–1375.[Medline] [Order article via Infotrieve]
22. Siegel R, Chae J, Forrester J, Ruiz CE. Angiography, angioscopy and ultrasound imaging before and after
percutaneous balloon angioplasty. Am Heart J.. 1990;120:1086–1090.[Medline] [Order article via Infotrieve]
23. Nissen SE, Gurley JC, Grines CL, et al. Intravascular ultrasound assessment of lumen size and wall
morphology in normal subjects and patients with coronary artery disease. Circulation.. 1991;84:1087–
1099.[Abstract/Free Full Text]
24. Hodgson JM, Reddy KG, Suneja R, Nair RN, Lesnefsky EJ, Sheehan HM. Intracoronary ultrasound
imaging: correlation of plaque morphology with angiography, clinical syndrome and procedural results in patients
undergoing coronary angioplasty. J Am Coll Cardiol.. 1993;21:35–44.[Abstract]
25. Frahm J, Merboldt KD, Bruhn H, Gyngell ML, Hanicke W, Chien D. A 0.3-second FLASH MRI of the
human heart. Magn Reson Med.. 1990;13:150–157.[Medline] [Order article via Infotrieve]
26. Wendland MF, Saeed M, Higgins CB. Strategies for differential enhancement of myocardial ischemia using
echoplanar imaging. Invest Radiol. 1991; 26:S236–S238.
27. Manning WJ, Li W, Edelman RR. A preliminary report comparing magnetic resonance coronary
angiography with conventional angiography. N Engl J Med.. 1993;328:828–832.[Medline] [Order article via
Infotrieve]
28. Lima JAC, Judd RM, Bazille A, Schulman SP, Atalar E, Zerhouni EA. Regional heterogeneity of human
myocardial infarcts demonstrated by contrast-enhanced MRI: potential mechanisms. Circulation..
1995;92:1117–1125.[Abstract/Free Full Text]
29. Zerhouni EA, Parish DM, Rogers WJ, Yang A, Shapiro EP. Human heart: tagging with MR imaging—a
method for noninvasive assessment of myocardial motion. Radiology.. 1988;169:59–
atvb.ahajournals.org/ cgi/ …/ 3626
13/ 18
2/ 23/ 2011
Intravascular Magnetic Resonance Im…
63.[Abstract/Free Full Text]
30. Poncelet B, Weisskoff RW, Wedeen VJ, Brady TJ, Kantor HK. Time of flight quantification of coronary
flow with echo-planar MRI. Magn Reson Med.. 1993;30:447–457.[Medline] [Order article via Infotrieve]
31. Clarke GD, Eckels R, Chaney C. Measurement of absolute epicardial coronary artery flow and flow
reserve with breath-hold cine phase-contrast magnetic resonance imaging. Circulation.. 1995;91:2627–
2634.[Abstract/Free Full Text]
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