Image quality evaluation of iterative model reconstruction on low tube voltage (80 kVp) coronary CT angiography in an animal study. (February 2016)

• Record Type: Journal Article
• Authors: Hu, Mao-Qing; Li, Meng; Liu, Zai-Yi; Huang, Mei-Ping; Liu, Hui; Liang, Chang-Hong
• Is Part Of: Acta radiologica. Volume 57:Number 2(2016:Feb.)
• Page Start: 170
• Page End: 177
• Publication Date: 2016-02
• Subjects: Computed tomography (CT) -- CT angiography -- CT spiral -- image manipulation/reconstruction -- thorax -- heart -- technology assessment; Radiology, Medical -- Periodicals; Radiography, Medical -- Periodicals; Radiotherapy -- Periodicals; 616.0757
• DOI: 10.1177/0284185114568909
• Languages: English
• ISSNs: 0284-1851

Abstract

Background: Iterative model reconstruction (IMR) is a newer generation iterative reconstruction method, but its value on coronary computed tomography (CT) angiography requires investigation. Purpose: To evaluate coronary image quality using IMR at a low-tube voltage of 80 kVp on coronary CT angiography in miniature pigs. Material and Methods: Five healthy miniature pigs underwent prospective electrocardiogram-gated coronary 256-slice CT angiography at 120 kVp and 80 kVp tube voltages, respectively. Filtered back projection (FBP) was used to reconstruct the 120 kVp standard-dose (SD) image sets (SD-FBP group), while iDose 4 and IMR were used to reconstruct the 80 kVp low-dose (LD) image sets (LD-iDose 4 and LD-IMR groups). Objective and subjective image qualities were compared among three groups. Results: There were no significant differences in mean CT values of the ascending aorta, left main coronary artery, and right coronary artery between the LD-IMR and LD-iDose 4 groups ( P > 0.05), but the values were significantly lower in the SD-FBP group than in those two groups ( P < 0.05). The image noise in the LD-IMR group (21.5 ± 3.9 HU) was significantly lower than in the LD-iDose 4 (63.7 ± 9.8 HU) and SD-FBP (50.6 ± 4.6 HU) groups ( P < 0.05). The signal-to-noise and contrast-to-noise ratios were significantly higher in the LD-IMR group than in the LD-iDose 4 and SD-FBP groups, respectively ( P < 0.05). Subjective scoring of image noise, streak artifacts, and overall image quality indicated that the LD-IMR group was consistently superior to the LD-iDose 4 and SD-FBP groups ( P < 0.05). Conclusion: IMR can significantly improve image quality at a low-tube voltage (80 kVp) with a 66% radiation dose reduction on coronary 256-slice CT angiography in miniature pigs.