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Objective:To investigate impacts of a deep learning image reconstruction (DLIR) algorithm on image quality of lower extremity CTA with low kVp and reverse flow direction scanning.Methods:From January 2021 to March 2021, fifty patients with suspected lower extremities diseases and received lower extremity CTA with low kVp and reverse flow direction scanning in Union Hospital affiliated to Fujian Medical University were retrospectively collected in this study. Six groups of CT images were reconstructed at the thickness of 0.625 mm using two algorithms including ASIR-V of three blending ratios (ASIR-V 20%, ASIR-V 50% and ASIR-V 80%) and DLIR of three strengths (DLIR-H, DLIR-M and DLIR-L). Regions of interest (ROIs) were placed on proximal abdominal aorta (AA), distal AA, left and right common iliac arteries, left and right femoral arteries (upper segment), left and right superficial femoral arteries (middle segment), left and right popliteal arteries. The CT value and SD value were measured for each group; the signal-noise ratio (SNR) and contrast-noise ratio (CNR) were calculated. The lower extremity CTA was divided into four segments, and the subjective evaluation was independently performed on noise and sharpness using 4 points scales by two radiologists. One-way analysis of variance was utilized to evaluate the differences in subjective scoring and objective parameters among the six groups.Results:For all arteries segments, with the increase of blending ratios for ASIR-V and reconstruction strength of DLIR, the SD values were reduced while SNR and CNR were increased (all P<0.05). Among the six groups, DLIR-H and ASIR-V80% images had lowest SD as well as highest SNR and CNR (all P<0.05). In comparison to ASIR-V20% and ASIR-V50% images, DLIR-H images showed lower SD, higher SNR and CNR values (all P<0.05). There were no statistical differences between ASIR-V80% and DLIR-H images in SD, SNR and CNR values (all P>0.05). Subjective scoring results showed that the DLIR-H images displayed the best noise performance for the entire lower extremity arteries from AA to the foot artery, and the sharpness scores of DLIR-H images were also significantly higher than ASIR-V80% (all P<0.05). Conclusion:DLIR can significantly reduce the image noise and improve the image quality in CTA for abdominal aorta to lower extremity arteries. DLIR-H showed the greatest noise reduction ability and the best effect balancing noise and sharpness, providing highest image quality.
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Objective To investigate the value of wide-detector Revolution CTA with 70 kV tube voltage and prospective ECG-gated technique in diagnosis of congenital heart disease (CHD) in infants and children.Methods Forty-five infants and children with complicated CHD underwent echocardiography and wide-detector Revolution CTA.According to the sur gical findings,the diagnostic efficiency of Revolution CTA and echocardiography were calculated and compared.The radiation effective dose (ED) and iodine dose were calculated.The quality of CT images was also evaluated.Results There were 25 separate cardiovascular anomalies including 6 congenital cardiac structure anomalies and 19 congenital extracardiac vascular anomalies.For congenital extracardiac vascular anomalies,there was significant difference of diagnostic accuracy and the detectable rate between CTA (99.77％ [853/855],97.73％ [86/88]) and echocardiography (98.71％ [844/855],88.64％ [78/88];x2 =6.28,5.72,both P＜0.05).The average of ED was (0.20±0.05)mSv and the mean iodine dose was (2.06± 1.09)g.All CT images were qualified for diagnosis.Conclusion The wide-detector Revolution CTA,with the prospective ECG-gated technique and 70 kV tube voltage,can provide high accuracy for assessment of CHD in infants and children,which can keep good image quality,with the low radiation dose.
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Objective To investigate the clinical value of gemstone spectral imaging (GSI) associated with patient-based low dose of contrast medium protocol in carotid CTA. Methods One hundred and twenty patients who were suspected with stenotic carotid artery or carotid plaque were prospectively enrolled in the study. All of them were divide into two groups by random number table. Group A (routine group): 60 were scanned with 120 kVp after the administration of moderate-concentration CM(320 mg/ml) with 5 ml/s injection velocity, Group B (low dose group):60 were scanned with GSI which was reconstructed using 50%ASiR after the administration of the same CM with 3 ml/s injection velocity. The contrast dose [(test bolus peak time +2 s – 5 s) × injection velocity] was calculated. Images of the two groups were compared in terms of arterial attenuation, signal-noise-ratio (SNR), contrast-to-noise ratio (CNR), and subjective image quality (IQ) score. The value of CT dose index volume (CTDIvol), dose length product (DLP) and effective dose (ED) was recorded, respectively. Data were analyzed by using independent samples t test or Mann-Whitney U test. Results The mean attenuation, noise, SNR, CNR, subjective image quality score, contrast dose, CTDIvol, DLP and ED of routine group was (363 ± 56)HU, (13 ± 4)HU, 30 ± 10, 38±13, 3.0 score, (69 ± 13) ml, 13.61 mGy,527 mGy · cm and 3.11 mSv, respectively. The above variables of low-dose-group was (378 ± 69) HU, (9 ± 4)HU, 48 ± 19, 62 ± 24, 2.0 score,(49 ± 7)ml, 12.72 mGy, 478 mGy · cm and 2.82 mSv, respectively. The mean attenuation and subjective IQ score of carotid artery had no significant differences statistically between two groups (P>0.05), respectively. The noise, SNR, CNR, contrast dose, CTDIvol, DLP and ED had significant differences statistically between two groups (P<0.05), respectively. Conclusion Compared with 120 kVp protocol, the use of GSI associated with patient-based low dose of contrast medium protocol in carotid CTA could provide equivalent image quality and higher SNR and CNR of carotid artery with a smaller amount of iodine and a lower radiation dose.
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OBJECTIVE: To investigate the effects of Gypsum Fibrosum and Gypsum Fibrosum Preparatum in promoting granulation. METHODS: The wounds of muscle layer were produced in rats by using surgical operation. Two round wounds, with diameter about 1.5 cm, were cut at the depilatory area of two sides of the back of each rat, with an interval of 2 cm, deep to muscle layer, and the thickness of the knife wound of muscle layer was about 0.15 cm. Forty SD rats with the wounds were randomly divided into 4 groups: untreated group, beifuji-treated group, Gypsum Fibrosum-treated group and Gypsum Fibrosum Preparatum-treated group, with 10 rats in each group. Then the wounds were sprinkled with powders of Gypsum Fibrosum and Gypsum Fibrosum Preparatum, or sprayed with beifuji solution, respectively. The healing state of granulation tissues of the wounds was observed at the eighth and fourteenth day respectively. RESULTS: The number of fibroblasts, the number of capillary tubes and the area of capillary tubes in granulation tissue of wounds in the Gypsum Fibrosum Preparatum-treated group were significantly higher than those in the untreated group and Gypsum Fibrosum-treated group (P0.05). CONCLUSIONS: Gypsum Fibrosum Preparatum can accelerate the formation of collagenoblast and micrangium in wounds, and the proliferation of granulation tissues, thus promoting the skin wounds to healing. The effect of Gypsum Fibrosum is changed after being calcined, and Gypsum Fibrosum Preparatum has obvious effect in promoting granulation.