Objective To investigate the feasibility of low-c oncentration iso_osmolar contrast agent together with low tube voltage and iterative reconstruction algorithm in rabbit liver computed tonography (CT) perfusion imaging.Methods A total of 15 bealthy New Zealand rabbits were scanned twice of liver CT perfusion scans each with 24 hours interval.The first scan (routine group) was acquired at 100 kV and 100 mAs with ultravist (370 mg/ml),while the second (double low group) was acquired at 80 kV and 100 mAs with iodixanol (270 mg/ml) at 24 hours after the first scan.The obtained images were reconstructed with filtered back projection (FBP) and adaptive iterative dose reduction (AIDR-3D)algorithms in the controlled and experimental groups,respectively.The perfusion parameters including hepatic artery perfusion(HAP),portal vein perfasion(PVP),hepatic perfusion index(HPI),and total liver perfusion(TLP) and image quality as image quality score,average CT value of abdomen aorta,signalto-noise ratio(SNR),carrier-to-noise ratio(CNR),and figure of merit(FOM) were compared used pair ttest or Mann-Whitney U-test between the two groups wherever appropriate.The effective radiation dose and iodine intake were also recorded and compared.Results The image quality and perfusion parameters had no significantly different between the two groups except for FOM.The effective radiation dose and iodine intake were 38.79％ and 27.03％ lower in the double low group.Conclusions Low concentration iso _osmolar contrast agent (iodixanol,270 mg/ml) together with low tube voltage (80 kV) helps to reduce radiation dose and iodine intake without compromising perfusion parameters and image quality in liver CT perfusion imaging.

Objective:To summarize the clinical experience of extracorporeal membrane oxygenation (ECMO) for neonatal refractory respiratory failure in a single medical center of Southwest China.Methods:From June 2020 to November 2021, the clinical data of neonates with refractory respiratory failure who received ECMO in the neonatal department of our hospital were retrospectively reviewed. The neonates were assigned into the survival group and the deceased group.Their general profile, clinical diagnosis, laboratory tests, ECMO operation, complications and prognosis were compared.Results:Eight neonates were included with five successfully withdrawal of ECMO and survived (5/8). For the three deceased neonates, two discontinued treatment because of intraventricular hemorrhage (grade Ⅲ~Ⅳ) and one confirmed congenital adrenal hyperplasia. No significant differences existed between the survival and the deceased groups in oxygenation index (OI), ECMO preparation and operation duration, usage of heparin, red blood cell suspension, platelet and sedative/analgesic drugs, therapeutic hypothermia and ECMO-associated complications. However, the deceased group had high OI values ( P=0.001), low lactate clearance ( P=0.005), more urine output during the first 24 h after ECMO ( P=0.046) and more fresh frozen plasma usage ( P=0.038). None of the five surviving children had significant developmental delay and neurological abnormalities during the 1-year follow-up. Conclusions:ECMO is effective treating neonatal refractory respiratory failure. Reducing the risk of intraventricular hemorrhage during ECMO may improve the survival rate.

Objective:To compare the therapeutic effects of modified plantar skin grafting and thigh skin grafting on the deep burn wounds of the back and buttocks.Methods:A retrospective cohort study was conducted to analyze the clinical data of 30 patients with deep burn wounds on their back and buttocks who were admitted to the 910th Hospital of Joint Logistic Support Force of PLA from January 2021 to April 2023, including 26 males and 4 females, aged 21-72 years [(49.9±14.0)years]. The total burn size was 50%-97% of the total body surface area (TBSA), with the third-degree burn on the back and buttocks 6%-16% TBSA. The burn wounds on the back and buttocks were repaired using plantar skin grafts alone, thigh skin grafts alone or plantar skin grafts combined with the grafts from other body parts. The patients were grouped according to the skin graft donor sites and the times of harvesting skin grafts: there were 20 patients undergone plantar skin grafting including 10 patient with plantar skin graft harvested once (group of plantar skin graft harvested once) and 10 patients with plantar skin graft harvested twice or three times (group of plantar skin graft harvested more than once), and 10 patients undergone thigh skin grafting harvested once (group of thigh skin graft harvested once). The areas of plantar skin grafts harvested at the last time and the wound areas on the back and butts that could be repaired each time were calculated. After the last harvest, the thickness of the stratum corneum, 7-day survival rate of the skin grafts, proportion of 3-month residual wound area in the skin graft area, healing time of the donor sites, and 6-month Vancouver Scar Scale (VSS) scores of the donor sites in the group of plantar skin graft harvested once were compared with those in the group of thigh skin graft harvested once and the group of plantar skin graft harvested more than once. The appearance and texture of the skin graft, patients′ walking patterns and complications were observed at 6 months after the last skin harvest.Results:All the patients were followed up for 6-18 months [(7.8±1.6)months]. In the 20 patients with plantar skin grafts harvested, the areas of skin grafts harvested at the last time were 2.5%-4.5% TBSA [(3.4±0.6)% TBSA] and the wound areas that could be repaired each time were 3%-8% TBSA [(5.5±1.5)% TBSA]. After the last harvest, the thickness of the stratum corneum in the group of plantar skin graft harvested once was (190.4±8.9)μm, which was significantly thicker than that in the group of thigh skin graft harvested once [(50.0±6.6)μm] and that in the group of plantar skin graft harvested more than once [(166.8±21.9)μm] ( P<0.01); the 7-day survival rate of the skin grafts, proportion of 3-month residual wound area in the skin graft area, healing time of the donor sites, and 6-month VSS scores of the donor sites were (93.6±2.3)%, 2.0 (0.1, 3.5)%, (9.9±1.8)days and (1.7±0.7)points in the group of plantar skin graft harvested once, (78.0±6.6)%, 5.3 (4.0, 5.8)%, (14.0±1.4)days and (4.9±2.3)points in the group of thigh skin graft harvested once, and (93.4±2.6) %, 2.0 (0.1, 3.8)%, (10.0±1.2)days and (1.8±0.8)points in the group of plantar skin graft harvested more than once. The group of plantar skin graft harvested once showed a significant increase in the 7-day survival rate and a significant decrease in the proportion of 3-month residual wound area in the skin graft area, healing time of the donor sites, and 6-month VSS scores of the donor sites in comparison with the group of thigh skin graft harvested once ( P<0.05 or 0.01), while there were no significant differences in above mentioned indices between the group of plantar skin graft harvested once and the group of plantar skin graft harvested more than once ( P>0.05). At 6 months after the last skin harvest, the skin graft areas on the back and buttocks were flat, hard and firm and all the patients in the three groups could walk normally, with no complications such as severe itching, pain or folliculitis in the skin graft area. Conclusions:In the treatment of burn wounds on the back and buttocks, compared with thigh skin grafting, modified plantar skin grafting has advantages of thicker stratum corneum, better wear resistance and pressure resistance in the skin graft areas, a higher survival rate of skin grafts, rapid healing, mild scar, and undisturbed walking pattern after surgery and no common complications. Moreover, skin grafts can be harvested repeatedly from the donor sites, with no impact on the therapeutic effects.