Objective To investigate the optimal window level and center level settings in the diagnosis of costal cartilage fracture with 256-slice spiral CT through ROC analysis. Methods Thirty patients with suspected costal cartilage fractures underwent 256-slices chest spirals CT scaning. CT value of costal cartilage was measured by three experienced radiologists. The soft copy images of three kinds of window level and window width (-100 HU/1120 HU, 100 HU/1120 HU, 300 HU/1120 HU) were analyzed independently in PACS with dual-blind method, and the diagnosis results were taken ROC analysis with SPSS 16.0 software. The diagnostic accuracy of three physicians were evaluated and compared according to the area under the ROC curve (Az). Results A total of 8 patients of costal cartilage fractures were confirmed by CT diagnosis combined with clinical follow-up. The mean CT value of 30 patients was (98.78±32.86) HU. The area under the ROC curve with the window level and center level settings of (100 HU/1120 HU) were bigger than that of other window level and window width (P=0.045,P=0.002). Kappa identity test showed that there was a powerful conformability between the diagnostic results of three physicians. Conclusion 256-slice spiral CT is a good way for the diagnosis of costal cartilage fractures with suitable window level and center level settings.

Objective:To investigate the perinatal prognosis and its impact factors for premature infants with twin-twin transfusion syndrome (TTTS) who were born at ≤34 weeks of gestation.Methods:A retrospective study was conducted on 68 pregnancies of TTTS with gestational age ≤34 weeks at delivery, among them 106 preterm infants (TTTS group) were admitted to the neonatal intensive care unit of the First Affiliated Hospital, Sun Yat-sen University from January 2003 to February 2019. During the same period, another 178 twins without TTTS, congenital malformation, and intrauterine intervention who matched the TTTS group in maternal age (differences within two years) and gestational age (differences within one week) were assigned as non-TTTS group. Perinatal prognosis of TTTS infants born at ≤34 weeks was analyzed by comparing the differences in postnatal early complications and perinatal outcomes (survival time morn than 28 days or not) between the TTTS and non-TTTS groups, recipient and donor twins, mild and severe TTTS infants, and among TTTS infants with different intrauterine interventions. The risk factors for perinatal survival in TTTS infants with gestational age ≤34 weeks were analyzed. Two independent samples t-test, one-way analysis of variance, rank-sum test, Chi-square test, and ordered logistic regression were used for statistical analysis. Results:(1) Among the 68 pregnancies, the overall perinatal survival rate of the neonates was 72.1% (98/136), the double-twin survival rate was 48.5% (33/68), and the rate of at least one survivor was 95.6% (65/68). (2) In the TTTS group, 62 were recipients and 44 were donors. Stage Ⅰ-Ⅱ TTTS was found in 41 cases (mild TTTS group) and stage Ⅲ-Ⅴ in 65 cases (severe TTTS group). (3) The rate of severe brain injury was higher in the severe-TTTS group than those in the mild-TTTS group [9.2% (6/65) vs. 0.0% (0/41), χ 2=4.01, P=0.045]. (4) Gestational age ≤28 weeks ( OR=101.90, 95% CI: 5.07-2 048.37), stage Ⅳ ( OR=14.04, 95% CI: 1.56-126.32) and stage Ⅴ TTTS ( OR=51.09, 95% CI: 3.58-728.81) were independent risk factors for death within 28 days (all P<0.05). (5) Compared with the non-TTTS group, the TTTS group had higher rates of neonatal anemia [51.9% (55/106) vs. 33.1% (59/178), χ 2=9.71], polycythemia [5.7% (6/106) vs. 0.6% (1/178), χ 2=7.18], neonatal persistent pulmonary hypertension [3.8% (4/106) vs. 0.0% (0/178), χ 2=6.81], sepsis [15.1% (16/106) vs. 7.3% (13/178), χ 2=4.40], state Ⅲ or higher retinopathy of prematurity [3.8% (4/106) vs. 0.0% (0/178), χ 2=6.81], congenital cardiac structural abnormality [19.8% (21/106) vs. 0.6% (1/178), χ 2=33.45], heart failure [8.5% (9/106) vs. 0.6% (1/178), χ 2=12.29], and renal insufficiency [14.2% (15/106) vs. 1.1% (2/178), χ 2=20.04] (all P<0.05). Conclusions:Compared with the twin premature infants without TTTS, those with TTTS and ≤34 gestational age were more likely to have cardiac, cerebral, and renal complications. The more severe the TTTS, the higher the incidence of severe brain injury. TTTS preterm infants with gestational age ≤28 weeks and stage Ⅳ or above have high risk of death.