ObjectiveTo discuss the 3D high resolution Magnetic resonance imaging (MRI) features of focal cortical dysplasia (FCD) in children.MethodsMRI data of 42 children with FCD confirmed by pathology, from April 2015 to June 2018, which were admitted to Qilu Children’s Hospital of Shandong University, were retrospectively analyzed. The following MRI signs were observed, blurring of junction of the gray matter-white matter, abnormality of structure with focal cortex (thick or thin), gray matter and white matter signal, white matter signal increased with T2WI/FLAIR, with or without transmantle sign (abnormal signal of white matter extending in the direction of ventricle), gray matter signal increased with T2WI/FLAIR, the abnormal sulci or gyri morphology and segmental and/or hypoplasia/atrophy of the lobes.ResultsAmong the 42 cases, 37 cases (88.1%) showed MRI positive signs, FCD typeⅠ accounted for 13 cases (35.1%), the main MRI features are focal blurring of junction in the gray matter-white matter, abnormality of structure with focal cortex in the corresponding part,and white matter signal increased with T2WI/FLAIR. FCD TypeⅡ accounted for 17 cases (45.9%), the MRI features are focal blurring of junction in the gray matter-white matter, abnormality of structure with focal cortex, white matter signal increased with T2WI/FLAIR, and transmantle sign. FCD TypeⅢ accounted for 7 cases (18.9%), among which hippocampal atrophy 2 cases (28.6%), dysembryoplastic neuroepithelial tumor (DNET) 2 cases (28.6%), section cell tumor 1 case (14.3%), softening lesion with gliosis 2 cases (28.6%).ConclusionThe 3D high-resolution MRI features of FCD in children are specific and could improve the detection rate of FCD lesions.
In order to understand how the biomechanical properties of rabbit cornea change over time after corneal ablation, 21 healthy adult rabbits were used in this study, with the left eye as experimental side and the right eye as the control side. Firstly, a lamellar knife was used to remove a portion of the anterior corneal surface tissue (30%~50% of the original corneal thickness) from the left eye of each rabbit, as an animal model simulating corneal refractive surgery. Secondly, postoperative experimental rabbits were kept for one, three, or six months until being euthanized. Strip specimens were produced using their corneas in vitro to perform a uniaxial tensile test with an average loading-unloading rate of approximately 0.16 mm/s. Finally, the visco-hyperelastic material constitutive model was used to fit the data. The results showed that there was a significant difference in the viscoelastic parameters of the corneas between the experimental and the control eyes at the first and third postoperative months. There was a difference in tangential modulus between the experimental and the control eyes at strain levels of 0.02 and 0.05 at the third postoperative month. There was no significant difference in biomechanical parameters between the experimental and the control eyes at the sixth postoperative month. These results indicate that compared with the control eyes, the biomechanical properties of the experimental eyes vary over postoperative time. At the third postoperative month, the ratio of corneal tangential modulus between the experimental and the control eyes significantly increased, and then decreased. This work lays a preliminary foundation for understanding the biomechanical properties of the cornea after corneal refractive surgery based on rapid testing data obtained clinically.
The aim of this study is to analyze the concordance between EDV, ESV and LVEF values derived from 18F-FDG PET, GSPECT and ECHO in patients with myocardial infarction. Sixty-four patients with coronary artery disease (CAD) and myocardial infarction were enrolled in the study.. Each patient underwent at least two of the above mentioned studies within 2 weeks. LVEF、 EDV and ESV values were analyzed with dedicated software. Statistical evaluation of correlation and agreement was carried out EDV was overestimated by 18F-FDG PET compared with GSPECT [(137.98±61.71) mL and (125.35±59.34) mL]; ESV was overestimated by 18F-FDG PET (85.89±55.21) mL and GSPECT (82.39±55.56) mL compared with ECHO (68.22±41.37) mL; EF was overestimated by 18F-FDG PET (41.96%±15.08%) and ECHO (52.18%±13.87%) compared with GSPECT (39.75%±15.64%), and EF was also overestimated by 18F-FDG PET compared with GSPECT. The results of linear regression analysis showed good correlation between EDV, ESV and LVEF values derived from 18F-FDG PET, GSPECT and ECHO (r=0.643-0.873, P=0.000). Bland-Altman analysis indicated that 18F-FDG PET correlated well with ECHO in the Left ventricular function parameters. While GSPECT correlated well with 18F-FDG PET in ESV, GSPECT had good correlation with Echo in respect of EDV and EF; whereas GSPECT had poor correlation with PET/ECHO in the remaining left ventricular function parameters. Therefore, the clinical physicians should decide whether they would use the method according to the patients' situation and diagnostic requirements.