Automatic vs manual coronary CT angiography reconstruction for whole-heart coverage CT scanner: a comparison study in general patient population.

BACKGROUND: Due to the limited temporal resolution and cardiac motion, coronary computed tomography angiography (CCTA) exam is one of the most challenging CT protocols which may require operating radiologist to apply additional phase adjustment or motion correction for image reconstruction. OBJECTIVE: To evaluate image quality between automatic and manual CCTA reconstruction in a 0.25 second rotation time, 16 cm coverage, single-beat, CT scanner with automated phase selection and AI-assisted motion correction. METHODS: CCTA exams of 535 consecutive patients were included. All exams were first reconstructed with an automatically selected phase. If there was an unacceptable motion artifact, a manual reconstruction process was performed by radiologists. Additionally, automatic image series which consist of auto-phase selection and a follow-up motion correction were reconstructed. For these two manual and automatic image series, a four-point Likert scale rating system was used to evaluate image quality of the coronary artery segment by two experienced radiologists, according to the 18-segment model. RESULTS: Fifty-one patients (9.5%) did not have satisfactory image quality after auto-phase selection. In these patients, the heart rate during scanning was higher (78.3±18.4 bpm) than in the remaining 484 patients (68.9±13.1 bpm). Overall, 734 out of the 918 vessel segments were identified for quality evaluation among 51 patients. Automatic and manual image series were rated as having average Likert scores of 3.48±0.62 and 3.32±0.67 (P < 0.001), respectively. CONCLUSIONS: Using a 0.25 second rotation speed, 16 cm z-coverage, CT scanner installed with an AI-assisted motion correction algorithm, the automatic image reconstruction with scanner equipped auto-phase-selection and motion correction algorithm outperforms manually controlled image reconstruction by radiologists. This suggests that the traditional CCTA exam reconstruction workflow could be altered allowing less radiologist involvement and becoming more efficient.

Image quality of automatic coronary CT angiography reconstruction for patients with HR ≥ 75 bpm using an AI-assisted 16-cm z-coverage CT scanner.

BACKGROUND: Coronary CT angiography (CCTA) is a complicated CT exam in comparison to other CT protocols. Exam success highly depends on image assessment of experienced radiologist and the procedure is often time-consuming. This study aims to evaluate feasibility of automatic CCTA reconstruction in 0.25 s rotation time, 16 cm coverage CT scanner with best phase selection and AI-assisted motion correction. METHODS: CCTA exams of 90 patients with heart rates higher than 75 bpm were included in this study. Two image series were reconstructed-one at automatically selected phase and another with additional motion correction. All reconstructions were performed without manual interaction of radiologist. A four-point Likert scale rating system was used to evaluate the image quality of coronary artery segment by two experienced radiologists, according to the 18-segment model. Analysis was done on per-segment basis. RESULTS: Total 1194 out of the 1620 segments were identified for quality evaluation in 90 patients. After automatic best phase selection, 1172 segments (98.3%) were rated as having diagnostic image quality (scores 2-4) and the average score is 3.64 ± 0.55. When motion corrections were applied, diagnostic segment number increases to 1192 (99.8%) and the average score is 3.85 ± 0.37. CONCLUSIONS: With the help of 0.25 s rotation speed, 16-cm z-coverage and AI-assisted motion correction algorithm, CCTA exam reconstruction could be performed with minimum radiologist involvement and still meet image quality requirement.

Correlation of coronary atherosclerosis and subclinical plaque phenotype of carotid artery: a 320-row multidetector computed tomographic angiography study.

OBJECTIVE: This study aimed to evaluate the correlation between coronary atherosclerosis and the phenotype of subclinical carotid artery plaque using 320-row computed tomography via an original single-injection protocol. METHODS: A total of 122 patients with suspected coronary artery disease but free of transient ischemic attack and stroke underwent computed tomographic angiography of carotid and coronary artery simultaneously. The mean attenuation was measured at each artery. The plaques in either carotid or coronary were classified into noncalcified, calcified, and mixed. Coronary plaque was evaluated with plaque score. Logistic regression analysis was used to determine the predictive value of coronary plaque score to the phenotype of carotid plaque. The prevalence of each phenotype of carotid plaque in different coronary stenosis groups was also analyzed. RESULTS: The mean (SD) attenuation of carotid and coronary artery was 456.3 (81.7) Hounsfield units (HU), 466.0 (85.5) HU, 446.5 (84.1) HU, and 476.4 (90.0) HU, respectively. There was a significant correlation between the noncalcified coronary plaque score and noncalcified plaque in carotid artery (odds ratio [OR], 2.9; P < 0.05). The coronary calcified plaque scores were significantly correlated with carotid mixed (OR, 1.8; P < 0.05) and calcified plaque (OR, 2.0; P < 0.05). The noncalcified plaque of carotid artery was more frequent (72.5% vs 67%) in the nonsignificant coronary stenosis group. CONCLUSIONS: The subclinical carotid plaque phenotypes are significantly associated with coronary plaque score and defined grade of stenosis in patients with suspected coronary artery disease. Our tailored computed tomographic angiography protocol may have a positive impact on secondary prevention.

The effect of combined application of Streptomyces rubrogriseus HDZ-9-47 with soil biofumigation on soil microbial and nematode communities.

Meloidogyne incognita causes significant damage to many different crops. Previous studies showed that Streptomyces rubrogriseus HDZ-9-47 is a promising biocontrol agent. Combining it with biofumigation improved its efficacy against M. incognita. In the present study, the reason for the improved efficacy of the combination was investigated by analyzing its impact on both the soil microbial and the nematode communities in the field. The results showed that the combined application reduced root galls by 41% and its control efficacy was greater than each treatment alone. Cultivation-based analyses showed that the combination treatment affected the soil microbial community. Actinomycetes and bacterial densities were negatively correlated with the root knot score. In contrast, the fungal densities were positively correlated with the root knot score. Denaturing gradient gel electrophoresis (DGGE) results showed that the combination of S. rubrogriseus HDZ-9-47 and biofumigation enriched beneficial microbes and reduced certain soil-borne fungal phytopathogens, thereby enhancing the efficacies of both S. rubrogriseus HDZ-9-47 and biofumigation against M. incognita. And HDZ-9-47 could colonize in soil. The total abundance of nematode and plant parasites, the ratio of soil fungivore nematode to fungivore plus bacterivore nematode, and the nematode diversity indices all decreased with the combination treatment. Overall, the results of this study demonstrate that combined application of HDZ-9-47 with biofumigation was a useful and effective approach to suppress M. incognita by manipulating soil microbial communities in field.