J Korean Soc Radiol.  2010 Oct;63(4):329-337.

The Effect of the Degree of Luminal Contrast-Enhancement on CT Measurement of Plaque Size: A Comparison with T1-weighted Magnetic Resonance Imaging

• Choi BW
• Hur J
• Lee HJ
• Kim YJ
• Kim TH
• Choe KO

Abstract

PURPOSE
We studied early and delayed contrast-enhanced CT to determine the effects of the degree of luminal enhancement on the measurement of plaque size compared to T1-weighted MRI.
MATERIALS AND METHODS
T1-weighted MRI and a two-phase contrast-enhanced CT was performed in 5 New Zealand white rabbits with atherosclerosis. Early-phase images were acquired during an expected peak enhancement period of the lumen; delayed-phase images were acquired 240 sec after administration of the contrast media. Anteroposterior and lateral luminal diameters (APD, LD), luminal area (LA), total vessel area (TVA), and plaque area (PA) of the aorta were measured on MRI and CT, respectively and compared to each other.
RESULTS
A total of 78 slices of the aorta were analyzed. PA, measured on T1-weighted MR images, was significantly greater than PA for both early-phase and delayed-phase CT (p < 0.001). The mean difference in PA was 12.13 +/- 5.52 mm2 (p < 0.001), 11.51 +/- 4.37 mm2 (p < 0.001), -0.62 +/- 3.87 mm2 (p = 0.159) for MRI vs. early-phase CT, MRI vs. delayed-phase CT, and early-phase CT vs. delayed-phase CT, respectively.
CONCLUSION
Different luminal densities by contrast enhancement do not affect the CT measurement of plaque area for the detection of obstructive coronary artery disease.

MeSH Terms

Aorta
Atherosclerosis
Contrast Media
Coronary Artery Disease
Glycosaminoglycans
Magnetic Resonance Imaging
Magnetic Resonance Spectroscopy
Magnetics
Magnets
Phenobarbital
Rabbits
Tomography, X-Ray Computed
Contrast Media
Glycosaminoglycans
Phenobarbital

Figure

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  Fig. 1 Measurements. A tracing of the anterior posterior luminal diameter (vertical lines), lateral luminal diameter (horizontal lines), luminal area (inner circles), and total vessel area (outer circles) on T1-weighted MRI (A), early-phase CT (B), and delayed-phase CT (C).

• 

  Fig. 2 Bland-Altman plots representing the bias and limits of agreement between MRI, and early-phase CT for the anteroposterior luminal diameter (A), lateral luminal diameter (B), luminal area (C), total vessel area (D), and plaque area (E). APD = anteroposterior luminal diameter, LD = lateral luminal diameter, LA = luminal area, TVA = total vessel area, PA = plaque area, MRI = magnetic resonance imaging, eCT = earlyphase CT, dCT = delayed-phase CT

• 

  Fig. 3 Bland-Altman plots representing the bias and limits of agreement between MRI, and delayed-phase CT for the anteroposterior luminal diameter (A), lateral luminal diameter (B), luminal area (C), total vessel area (D), and plaque area (E). APD = anteroposterior luminal diameter, LD = lateral luminal diameter, LA = luminal area, TVA = total vessel area, PA = plaque area, MRI = magnetic resonance imaging, eCT = earlyphase CT, dCT = delayed-phase CT

• 

  Fig. 4 Bland-Altman plots representing the bias and limits of agreement between early-phase CT and delayed-phase CT for the anteroposterior luminal diameter (A), lateral luminal diameter (B), luminal area (C), total vessel area (D), and plaque area (E). APD = anteroposterior luminal diameter, LD = lateral luminal diameter, LA = luminal area, TVA = total vessel area, PA = plaque area, MRI = magnetic resonance imaging, eCT = earlyphase CT, dCT = delayed-phase CT

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