High-pitch coronary CT angiography in dual-source CT during free breathing vs. breath holding in patients with low heart rates.
BACKGROUND
Coronary CT angiography (CCTA) is usually performed during breath holding to reduce motion artifacts caused by respiration. However, some patients are not able to follow the breathing commands adequately due to deafness, hearing impairment, agitation or pulmonary diseases. The aim of this study was to evaluate the potential of high-pitch CCTA in free breathing patients when compared to breath holding patients.


METHODS
In this study we evaluated 40 patients (20 free breathing and 20 breath holding patients) with a heart rate of 60 bpm or below referred for CCTA who were examined on a 2nd generation dual-source CT system. Image quality of each coronary artery segment was rated using a 4-point grading scale (1: non diagnostic-4: excellent).


RESULTS
Mean heart rate during image acquisition was 52 ± 5 bpm in both groups. There was no significant difference in mean image quality, slightly favoring image acquisition during breath holding (mean image quality score 3.76 ± 0.32 in breath holding patients vs. 3.61 ± 0.45 in free breathing patients; p = 0.411). Due to a smaller amount of injected contrast medium, there was a trend for signal intensity to be slightly lower in free breathing patients, but this was not statistically significant (435 ± 123 HU vs. 473 ± 117 HU; p=0.648).


CONCLUSIONS
In patients with a low heart rate who are not able to hold their breath adequately, CCTA can also be acquired during free breathing without substantial loss of image quality when using a high pitch scan mode in 2nd generation dual-source CT.
Institute for Clinical Radiology; Ludwig-Maximilians-University Hospital Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany. Electronic address: bernhard.bischoff@med.uni-muenchen.de.
Bernhard
B
Bischoff
Felix G
FG
Meinel
Alessandra
A
Del Prete
Maximilian F
MF
Reiser
Hans-Christoph
HC
Becker
D062485:Breath Holding; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
Breath holding; CCTA; Dual-source CT; Free breathing; High-pitch mode