Application Of100kVp Coronary Computed Tomography Angiography With Low Concentration Iodinated Contrast Media By320-row CT

PartⅠApplication of100kVp coronary computed tomographyangiography with low concentration iodinated contrast media innon-obese patientsObjective The article is to explore the clinical value of100kVp withIodixanol(270mgI/ml) scan protocol by using320-MDCT(multi-detecter CT)scanner.Methods101patients (56men and45women; body mass index,21-26kg/m2) withsuspected or known coronary heart disease underwent coronary CTA (CCTA) with a320-MDCT scanner, were divided into two groups randomized. Fifty-twopatients(group A) received100kVp with iodixanol(270mgI/ml), and the remainingforty-nine patients(group B) received120kVp with Iopamidol(370mgI/ml). Imagequality was assessed, using a five-point grading scale by two independentreaders(Deputy director of Physicians or above). The scoring results were comparedbetween the two groups. The mean intraluminal attenuation, image noise,signal-to-noise ratio(SNR), contrast-to-noise ratio(CNR), radiation dose, and iodinedose were also compared between the two groups.Results Statistically significant difference of effective dose(ED) and iodine dosewere found between group A and B(P＜0.05), both of them in group A were lessthan group B. The mean intraluminal attenuation, image noise, SNR, and CNR were statistically significant difference between them(P＜0.05). Except image noise, theother results of group B were higher than group A. A total of653coronary arterysegments were evaluated in group A and598segments in group B. The image qualitywas good with both scan protocols, with no statistically significant difference betweenthem(P＞0.05).Conclusions The scanning protocol(100kVp+iodixanol,270mgI/ml) of320-MDCT scanner can achieve the image quality as the high concentration contrastmedia with120kVp in CCTA, also reduce the radiation dose and iodine dosesignificantly. PartⅡ Application of low tube voltage coronary computedtomography angiography with low dose iodine contrast agent inoverweight patientsPurpose: To evaluate CT image quality in overweight, coronary heart disease (CHD)patients using reduced radiation dose and reduced iodine intake i.e.,“double low”(low tube voltage/low iodine dose contrast agent) scanning protocol and AdaptiveIterative Dose Reduction (AIDR) reconstruction algorithm.Methods: A total of179consecutive CHD patients with body mass index>26kg/m2but <30kg/m2were randomly assigned to two groups (group A:53males,39females,average age:61.52y±11.23y, and group B:40males,47females, average age:61.32y±12.40y) based on tube voltage, contrast agent and algorithm used. Group Areceived “double low” scanning protocol (iodixanol at270mg/ml,100kVp tubevoltage and AIDR). Group B received the conventional protocol [iopamidol (370mgI/ml),120kVp tube voltage, and filtered back projection (FBP)].Results: The CTDIvol, DLP, ED, and iodine intake of patients in double low”group Awere significantly lower than conventional”group B (P＜0.05). The intraluminal CTvalue and contrast enhancement in group A were also significantly less than group B (P＜0.05), while the image noise using AIDR in group A was significantly lowerthan group B using FBP (P＜0.05). However, the SNR, CNR, and image qualityscores between the two groups were comparable.Conclusions: Use of320-row CT with a “double low” scanning protocol for CCTA inoverweight patients not only provided images of diagnostic quality but also reducedboth radiation dose and iodine intake during scanning.