Objective:To investigate the feasibility of the ultrasound "triangular method" in evaluating the morphology of the aortic arch in normal mid-to-late trimester fetuses，establish the gestational age-specific reference ranges for its morphological parameters，and to analyze their correlations with gestational age（GA）and cardiac valve annulus diameters.Methods:A prospective study was conducted on 317 normal singleton fetuses at 20-38 +6 weeks of gestation from the Second Xiangya Hospital of Central South University. Morphological parameters including arch length（a+b），arch width（w），arch height（h）and arch angle（θ）were measured using the "triangular method" in the aortic arch long-axis view. Arch tortuosity（a+b/w）and height-to-width ratio（h/w）were calculated. Linear regression was used to analyze correlations between arch length，width，height and GA，the reference intervals were established. Pearson correlation was applied to assess relationships between angle，tortuosity，height-to-width ratio and GA，cardiac valve annulus diameters（aortic，pulmonary，mitral，tricuspid）. Results:Aortic arch length，width and height showed strong positive correlations with GA（ r = 0.88，0.88，0.85；all P < 0.001）. The arch angle，tortuosity，and height-to-width ratio were independent of GA（all P > 0.05），with reference values of（69.2 ± 6.1）°，1.7 ± 0.1，and 0.7 ± 0.1，respectively. These parameters also showed no significant correlations with cardiac valve annulus diameters（all P > 0.05）. Conclusions:The ultrasound "triangular method" systematically quantifies fetal aortic arch morphology. The stability of arch angle，tortuosity and height-to-width ratio during mid-to-late gestation may provide a morphological benchmark for prenatal screening of aortic arch anomalies.

Objective:To investigate the feasibility of the ultrasound "triangular method" in evaluating the morphology of the aortic arch in normal mid-to-late trimester fetuses，establish the gestational age-specific reference ranges for its morphological parameters，and to analyze their correlations with gestational age（GA）and cardiac valve annulus diameters.Methods:A prospective study was conducted on 317 normal singleton fetuses at 20-38 +6 weeks of gestation from the Second Xiangya Hospital of Central South University. Morphological parameters including arch length（a+b），arch width（w），arch height（h）and arch angle（θ）were measured using the "triangular method" in the aortic arch long-axis view. Arch tortuosity（a+b/w）and height-to-width ratio（h/w）were calculated. Linear regression was used to analyze correlations between arch length，width，height and GA，the reference intervals were established. Pearson correlation was applied to assess relationships between angle，tortuosity，height-to-width ratio and GA，cardiac valve annulus diameters（aortic，pulmonary，mitral，tricuspid）. Results:Aortic arch length，width and height showed strong positive correlations with GA（ r = 0.88，0.88，0.85；all P < 0.001）. The arch angle，tortuosity，and height-to-width ratio were independent of GA（all P > 0.05），with reference values of（69.2 ± 6.1）°，1.7 ± 0.1，and 0.7 ± 0.1，respectively. These parameters also showed no significant correlations with cardiac valve annulus diameters（all P > 0.05）. Conclusions:The ultrasound "triangular method" systematically quantifies fetal aortic arch morphology. The stability of arch angle，tortuosity and height-to-width ratio during mid-to-late gestation may provide a morphological benchmark for prenatal screening of aortic arch anomalies.

Objective To explore the clinical effect of lacrimal endoscope assisted minimally invasive lacrimal duct recanalization combined with silicone tube intubation in the treatment of lacrimal duct obstruction. Methods 3 cases(4 eyes)of the superior canaliculus obstruction,5 cases(6 eyes)of the inferior canaliculus,20 cases (29 eyes) of common canaliculus and 25 cases (36 eyes) of nasolacrimal duct were enrolled. They were randomly divided into two groups:Group A(40 eyes)treated with lacrimal endoscope assisted laser lacrimal forming combined with silicone tube implantation and Group B(36 eyes)with lacrimal endoscope assisted laser lacrimal forming combined with silicone tube implantation. The cases were all followed up for 3-6 months after treatment. Results Except the intraoperative bleeding,there were no significant differences in the incidence of various complications. All the eyes could be recanalized under the aid of lacrimal endoscope. The total effective rates were 87.50% and 91.43% in Group A and B,respectively. The difference was not statistically significant. Conclusion Lacrimal endoscope assisted minimally invasive lacrimal duct recanalization combined with silicone tube intubation is a safe,effective,and minimally invasive method to recanalize the lacrimal obstruction.

Objective To discuss the clinic and imaging features of solitary enchondroma.Methods Radiography,CT and MRI were performed in 11 cases of solitary enchondroma confirmed by pathology.The imaging findings were retrospectively analysed.Results The tumors in 11 cases localized in metacarpal bone in 3, in bones of fingers in 4, in shaft of humerus in one,in metaphysis of femur in 2 and in metaphysis of tibia in one.Plain radiography showed typical radiographic features including a well defined central lucency in the diaphysis of the metacarpal bones and bones of fingers with calcifications inside the lesions and lobulated contour,the cortex was thinned and cortical expansion also might occur.The lesions appeared as soft tissue density with stippling calcification on CT,low signal intensity on T1WI and mixed mainly high signal intensity on T2WI.A low signal zone around the lesion could be seen on T2WI in one case.Conclusion The qualitative and differential diagnosis of solitary enchondroma can be made mostly by imaging examination.