Three-Dimensional Coronary MR Angiography Performed with Subject-Specific Cardiac Acquisition Windows and Motion-Adapted Respiratory Gating
Sven Plein1,
Tim R. Jones1,
John P. Ridgway2 and
Mohan U. Sivananthan1
1 British Heart Foundation—Cardiac MRI Unit, Rm. 170, D Fl., Jubilee
Bldg., Leeds General Infirmary, Great George St., Leeds LS1 3EX, United
Kingdom.
2 Department of Medical Physics, Leeds General Infirmary, Leeds, LS1 3EX, United
Kingdom.
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Fig. 1A. —Coronary motion assessment in 56-year-old man with history of
lateral wall myocardial infarction. First phase from 30-phase horizontal
long-axis cine MR image acquired with steady-state free precession pulse
sequence shows right coronary artery (white arrow) and circumflex
artery in cross section (black arrow).
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Fig. 1B. —Coronary motion assessment in 56-year-old man with history of
lateral wall myocardial infarction. Every third phase shown from same cine MR
image as in A, with delay times after R-wave of 43-763 msec. Right
coronary artery and circumflex artery can be seen in all phases. White circle
represents position of right coronary artery at end-diastole to illustrate
in-plane coronary motion in subsequent phases of cardiac cycle. There is no
perceptible motion of coronary arteries between last three images (delay
times, 603-764 msec). Subject-specific trigger delay for coronary MR
angiography was therefore set to 603 msec, and acquisition window was set to
161 msec in this patient.
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Fig. 2. —Scatterplot shows subject-specific trigger delays determined
from coronary motion scan versus R-R interval. Dotted line represents trigger
delay as suggested by Stuber et al.
[10]. Solid line represents
trigger delays calculated with empirically modified formula.
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Fig. 3. —Bar chart shows means and standard deviations (error bars) of
subject-specific trigger delays as function of mean heart rate (rounded to
nearest multiple of 5 beats per minute [bpm]). Large error bars reflect wide
variation of subject-specific trigger delays at similar heart rates.
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Fig. 4. —Scatterplot shows duration of subject-specific data
acquisition window versus mean R-R interval. Dotted line represents
acquisition window used for conventional acquisition. Subject-specific
acquisition windows are longer in all subjects compared with conventional
acquisition windows.
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Fig. 5A. —68-year-old man with history of inferior myocardial
infarction. Reformatted three-dimensional (3D) coronary MR angiogram of right
coronary artery acquired with conventional 3D navigator-gated technique
reveals midvessel occlusion (arrow).
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Fig. 5B. —68-year-old man with history of inferior myocardial
infarction. Reformatted 3D coronary MR angiogram of right coronary artery at
same level as A but acquired with subject-specific acquisition window
and motion-adapted gating shows similar image quality as in A and also
reveals occlusion (arrow) at mid vessel.
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Fig. 5C. —68-year-old man with history of inferior myocardial
infarction. Coronary radiographic angiogram that corresponds to A and
B confirms occlusion (arrow) of right coronary artery.
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Fig. 6A. —63-year-old man with suspected coronary artery disease.
Reformatted three-dimensional (3D) coronary MR angiogram of left coronary
system acquired with conventional 3D navigator-gated technique shows normal
anatomy of left anterior descending artery (white arrow) and first
diagonal branch (black arrow).
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Fig. 6B. —63-year-old man with suspected coronary artery disease.
Reformatted 3D coronary MR angiogram of left coronary system at same level as
A but acquired with subject-specific acquisition window and
motion-adapted gating reveals similar image quality as in A and shows
normal anatomy of left anterior descending artery (white arrow) and
first diagonal branch (black arrow).
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Fig. 6C. —63-year-old man with suspected coronary artery disease.
Coronary radiographic angiogram that corresponds to A and B
shows normal anatomy of left anterior descending artery (white arrow)
and first diagonal branch (black arrow).
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Fig. 7. —Reformatted MR images of right coronary arteries from all
five volunteers in comparison group. MR images in top row were acquired with
conventional three-dimensional navigator-gated MR angiography technique.
Corresponding MR images in bottom row were acquired with subject-specific
acquisition windows and motion-adapted gating. Heart rate in beats per minute
(bpm) and length of subject-specific acquisition windows were (from left to
right) 52 bpm/154 msec, 80 bpm/85 msec, 85 bpm/112 msec, 65 bpm/145 msec, and
50 bpm/169 msec.
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Copyright © 2003 by the American Roentgen Ray Society.
