Keywords:
Chronic obstructive airways disease, Venous access, Contrast agent-intravenous, CT-Angiography, CT, Vascular, Pulmonary vessels, Breast
Authors:
T. Kitai; Maiduru. kyoto pref/JP
DOI:
10.1594/ecr2012/C-0087
Methods and Materials
Patients
78 consecutive patients (39 men,
age 61±12 years ) with known paroxysmal atrial
fibrillation underwent
Equipment
64-slice multi detector computed tomography (MDCT) in the caudocranial direction between Jan 2010 and Jun 2011 was included.
The data were performed using MDCT ( Aquilion 64,
Toshiba Medical Systems,Japan).
This CT system contains one X-ray tube with a 64 channel detector,
collimation of 0.5mm.
CTDI and Hounsfield units (HU) were recorded from monitor display of Aquilion 64.
Protocol
Current protocol: Non ECG-triggering,
120kV,
175mAs/rot,
Helical Pitch (HP) 41.0
CM (370mg/ml) injection speed at 4.0ml/sec,
injection time 15sec.
New protocol: ECG Dose Modulation(30-R),
80kV,175mAs/rot,
HP12.6.
Analysis
Correlation between electrocardiogram and diameter of four main pulmonary veins (PV) was calculated.
Difference between a current protocol and a new protocol was considered.
Computed tomography dose index (CTDI),
standard deviation of image noise,
contrast ratio of left atrium and right atrium in Hounsfield (HU),
and visual evaluation was assessed by two independent readers using a 5point grade scale.
Transit time of contrast medium from right ventricle to left ventricle,
and examination time were investigated
Injection delay was also examined with blood circulation.