Fluctuant tonus of the coronary arteries possibly documented by repeated multidetector row computed tomography

Abstract

Objective:

Recent advances in multidetector row computed tomography (MDCT) have made it possible to diagnose coronary stenosis with high sensitivity. However, coronary arterial tonus has not been considered when reading MDCT. We hypothesized that MDCT can document fluctuant tonus of the coronary arteries.

Methods:

The study population consisted of 39 consecutive patients who underwent MDCT twice in our institution with 64-row dual-source MDCT. Measurements were performed with stretched multiplanar reconstruction images using the full width at half maximum method. The coronary arteries were measured at each segment, and the same measurement was performed in the ascending aorta and the left internal thoracic artery (ITA). The percent diameter changes between the first and second measurements were examined in each segment of the coronary arteries and compared with those in the aorta or the ITA.

Results:

The average percent diameter changes were statistically equivalent between the coronary arteries and the aorta or the ITA. On the other hand, the percent diameter changes in distribution were significantly larger in the coronary arteries than those in the aorta or the ITA. This suggests that the diameter of the coronary arteries is liable to show variation compared to that of other arteries.

Conclusion:

This study confirmed for the first time that coronary arteries can fluctuate substantially and that these changes can be documented by MDCT. Changes in coronary arterial tonus should therefore be considered when reading MDCT.

Keywords::

• coronary spastic angina
• coronary arterial tonus
• false positive study

Supplementary materials

Table S1 Medications administered to each patient at the time of the first and second MDCT examinations

Table S2 Changes in the diameters of the aorta, ITA, and coronary arteries with the same medication between the first and second MDCT examinations

Table S3 Changes in the diameters of the aorta, ITA, and coronary arteries between the first and second MDCT examinations using nitroglycerin inhalation

Figure S1 The changes in the diameters of the aorta, left ITA, and coronary arteries in the individual patients.

Notes: The changes in diameter in the aorta, ITA, and coronary arteries (#1, 3, 5, 6, 7, 8, 9, 11, and 13) in all patients. The dotted lines show the null point of the diameter changes.
Abbreviation: ITA, internal thoracic artery.