[Diagnostic value of magnetic resonance imaging in special-site ectopic pregnancy].

OBJECTIVE: To explore the magnetic resonance imaging (MRI) features and diagnostic value of special-site ectopic pregnancy. METHODS: The MRI features of special-site ectopic pregnancy on 39 pathologically confirmed cases were retrospectively analyzed. All cases received ultrasonic inspection, MRI plain scan and 11 cases underwent enhanced scan. RESULTS: In 39 cases, there were 3 cases of interstitial tubal pregnancy (n = 3), cornual pregnancy (n = 8) and uterine scar pregnancy (n = 28). The accuracy rates of location and diagnosis were 94.9% and 82.1% respectively. And they were both higher than the rates of ultrasound. They were classified into two groups by clinical outcomes:pregnancy and miscarriage. In 22 cases of pregnancy, there were sac in sac (n = 9) and complete fertilized egg (n = 13). In 17 cases of miscarriage, there were irregular honeycomb (n = 7), ring (n = 6) and mass (n = 4). Among 11 enhanced cases, there were significant enhancement (n = 4), flake or cord-like enhancement (n = 5), a little strengthen on edge (n = 1) and no enhancement (n = 1). The group had intrauterine decidual tissue hyperplasia (n = 22), ovarian cyst (n = 8), pelvic fluid (n = 6), adenomyosis (n = 3), fibroid (n = 2), endometriosis in pelvic and abdominal wall scar area (n = 1) and mild hydrops in right kidney and ureter (n = 1). CONCLUSION: The MRI features of special-site ectopic pregnancy are characteristic and important for clinical treatment.

[Clinical application of multi-slice computed tomography angiography low-dose scan in pulmonary veins and left atrium].

OBJECTIVE: To investigate the clinical application of multi-slice computed tomography angiography (MSCTA) low-dose scan in pulmonary veins and left atrium and to reduce the radiation dose. METHOD: 100 middle-sized patients underwent pulmonary veins and left atrium MSCTA were collected and randomly divided into five groups averaged. The tube current were 250 mAs (conventional dose), 200, 150, 100, and 80 mAs (low dose), respectively. The CT scan length (L), volume CT dose index (CTDIvol) and dose length product (DLP) of five groups were recorded automatically, and the effective dose(ED) was measured. The signal to noise ratio (SNR) and the contrast to noise (CNR) of thoracic aorta at the middle level of left atrium were measured to evaluate the image quality objectively. The image quality of pulmonary veins and left atrium MSCTA was evaluated by two experienced radiologists using double-blind method. The results were analyzed by statistics. RESULT: (1) The CTDIvol(mGy), DLP(mGy*cm) and ED decreased evidently with the scan dose reduced, and the difference had statistical significance. (2) The image quality was mainly excellent and good in 100 mAs and the above, and it was mainly good in 80 mAs group. The image quality decreased with mAs reduced. The difference of SNR and CNR within five groups had statistical significance. The satisfaction degree of subjective evaluation on image quality of the five groups was up to 100%. CONCLUSION: On the premise that the image quality confirmed to the clinical diagnosis, the low dose scan in pulmonary veins and left atrium SCTA can obviously reduce radiation dose, and it had important clinical significance.

[The diagnostic value of MSCT multi-dimensional reconstructions for congenital vascular ring with tracheal stenosis].

OBJECTIVE: To evaluate the diagnostic value of multi-slice CT (MSCT) reconstructions for congenital vascular rings together with tracheal stenosis. METHODS: 9 cases of children with congenital vascular ring and tracheal stenosis confirmed by surgery were collected in the study, all cases had undergone thin slice CT contrast enhancement, the MSCT data were transmitted to the workstation for multiplanar reconstruction (MPR), volume rendering technique (VRT) and VR transparency reconstruction. With the surgical results as the gold standard, the imaging characteristics of echocardiography (UCG) and MSCT were comparatively analyzed. RESULTS: In 9 cases, there were 4 cases of pulmonary artery sling, 3 cases of right aortic arch combination with left aberrant subclavian artery, 1 case of double aortic arch, 1 case of innominate artery compression syndrome. In this group, 5 cases were accompanied with other cardiac malformations (tetralogy of Fallot in 2 cases, double outlet right ventricle with patent ductus arteriosus and ventricular septal defect in 1 case, ventricular septal defect in 1 case, double superior vena cava in 1 case), 1 case of tetralogy of Fallot demonstrated many tortuous collateral arteries around aorta. All malformations were well displayed by VRT, MPR. VR transparency reconstruction can stereoscopically display trachea and bronchial compression condition, the main trachea was compressed in 6 cases, the main trachea and left main bronchus was compressed in 2 cases, the main trachea and left main bronchus was compressed in 1 cases, UCG detected all intracardiac malformations, 1 case of pulmonary artery sling was misdiagnosed as patent ductus arteriosus, 8 cases of vascular rings, tracheal and bronchial stenosis were missed. CONCLUSION: MSCT reconstruction technology is a noninvasive, rapid diagnostic method, it can clearly show the congenital vascular rings abnormalities and the degree of tracheal stenosis, it has important significance for clinic treatment.