Purpose To evaluate the diagnostic value of two-dimensional multiple-echo recalled gradient echo (2D MERGE) with flexural position in the hirayama disease. Materials and Methods Conventional MRI and axial MERGE images (7 cases) were analyzed and the anteroposterior diameter was measured at C6 vertebral body, and the structure of spinal, extramedullary and subdural space and extradural space were compared. Results The anteroposterior diameter was (5.7±0.6) cm and (4.7±0.5) cm in the neutral position and flexural position (t=-2.95, P<0.05). The“butterfly”shape of spinal grey matter could not be detected in the 4 cases on MERGE with flexural position, which could not demonstrated on the conventional MR images. 2D MERGE was not sensitive for the CSF flow artefacts and the contrast between spinal and surrounding structures was improved. However, the vascular images could not displayed on 2D MERGE images. Conclusion 2D MERGE sequence is better than T1WI and T2WI on sagittal view and T2WI on axial view in the pathological changes of hirayama disease except flow-empty vein sign, thus it has an important role in diagnosing hirayama disease.

Purpose To investigate the MRI characteristics and differential diagnosis of intraventricular meningioma. Materials and Methods The clinical manifestation and MRI characteristics was retrospectively analyzed in the 11 patients with confirmed intraventricular meningioma by pathology. Results The intraventricular fibrocellular meningioma (7 cases) showed iso- and slightly short T1 signal and short and heterogeneously iso-T2 signal. The syncytial (1 case) and mixed (1 case) miningioma in the fourth ventricle, the syncytial meningioma in the third ventricle, and endothelial meningioma in the septum pellucidum (1 case) all showed slightly long T1 and slightly long T2 signal. Pathology results showed that 7 cases of fibrocellular meningioma in lateral ventricle, 1 case of syncytial meningioma and mixed type in the fourth ventricle, 1 case of syncytial meningioma in the third ventricle, 1 case of endothelial meningioma in septum pellucidum Conclusion The fibrocellular type was commonly encountered for the lateral ventricle meningioma, and hypointensity on T2WI could be regarded as its typical MRI characteristics, and it is diffcult for the differential diagnosis for the other intraventrical meningiomas.

Purpose To explore the methods of selectively visualizing hepatic portal vein by using three-dimensional fast imaging employing steady state acquisition combined with in-flow inversion recovery labeling pulse at 3.0 Tesla. Materials and Methods Ten healthy volunteers were examined under different TI (1200, 1400, 1600, 1800 ms), and the vessel-to-liver contrast ratio of the main portal vein, right portal vein, and left portal vein were measured. Results Non-contrast-enhanced MRA images of portal vein were obtained successfully in all ten volunteers. The signal intensity of peripheral portal branches gradually increased when TI increased from 1200 ms to 1600 ms, and the highest vessel-to-liver contrast ratio occurred when TI was 1400 ms. Conclusion Non-contrast enhanced magnetic resonance angiography of the hepatic portal vein can be successfully achieved at 3.0T high field MRI. A fixed TI of 1400 ms is preferable.

Purpose To explore the value of low tube voltage, original data iterative reconstruction (SAFIRE) and intelligent optimum tube voltage scanning (CARE kV) technology in reducing radiation dose of high resolution CT (HRCT) temporal bone scanning and its impact on image quality. Materials and Methods Ninety patients with ear problem underwent clinical HRCT scan. All the patients were randomly divided into group A (conventional scanning), group B (CARE kV) and group C (low tube voltage) according to chronological order, with 30 cases in each group. Image quality was double-blind scored by two qualified radiologists. CT value, noise, contrast to noise ratio (CNR), signal to noise ratio (SNR), CT dose index volume (CTDIvol), dose-length product (DLP) and effective dose (ED) were compared among three groups. Results Image quality and the average CT value had no statistical difference among three groups (F=3.70, 3.61;P>0.05);noise, CNR, SNR, CTDIvol, DLP and ED had statistical difference among three groups (F=1.23, 1.42, 2.05, 2.13, 1.79, 1.32; P<0.05). Compared with group B, noise reduced about 14.1%in group C, while CNR and SNR increased about 32.1%and 26.3%, respectively (q=3.64, 3.45, 4.36; P<0.05). CTDIvol, DLP and ED were significantly different between group B and group C (q=3.13, 4.24, 4.24; P<0.05). Conclusion Scanning with low tube voltage, SAFIRE and CARE kV technology not only effectively reduce radiation dose, but also obtain satisfactory image quality. It should be widely utilized.

Purpose To study the exposure extent of internal carotid artery siphon (ICAS) before and after removing anterior clinoid process (ACP) using multislice spiral CT (MSCT) simulation, and to improve the tumor resection rate and ensure the operation effect. Materials and Methods MSCT three-dimensional images reconstruction simulating supraorbital keyhole approach of 100 patients (200 sides) were observed, the distance between the crotch of anterior cerebral artery and middle cerebral artery and ICAS before and after removing ACP (exposure extent) was measured. Results In 100 patients (200 sides ACP), the exposure extent before and after removing ACP were (14.3±3.9) mm and (30.5±4.2) mm, respectively on the left side with statistical difference (t=45.278, P<0.001), and were (15.9±3.8) mm and (31.8±3.9) mm, respectively on the right side with statistical difference (t=40.513, P<0.001). The exposure extent increased (16.3±3.6) mm and (15.8±3.9) mm, respectively on the left and right side with no statistical difference (t=0.251, P>0.05). Conclusion MSCT simulating supraorbital keyhole approach in removing ACP can effectively increase the exposure length of ICA, and enlarge the exposure extent of sella region, thus provide reliable imaging information for removing tumor and selecting surgical project in this region.

Purpose To explore the value of three vessels and trachea view in rapid screening of aortic arch malformations. Materials and Methods 51 fetal subjects who were prenatally diagnosed with aortic arch abnormalities were enrolled, and their diagnoses were confirmed by postnatal echocardiography or autopsy results after induction. Targeted fetal cardiac examinations were conducted under obstetric ultrasound examination conditions, ultrasound images were restored and compared with sonographic features of normal aorta. Results Among the 51 fetus cases with aortic arch anomalies, right-oriented aortic arch with left subclavian artery vagus was shown in 17 cases, left-oriented aortic arch with right subclavian artery vagus in 2 cases, double aortic arch in 2 cases, aortic arch disarticulation in 6 cases, and aortic arch coarctation in 24 cases. Diagnostic accuracy of ultrasound was 94.1%. Sonographic changes were displayed in three-vessel or three vessels and trachea view in all cases. Conclusion Three vessels and trachea view plays an important prompt role in ultrasound diagnosis for fetal aortic arch abnormalities. But when it is manifested as the“1oo”sign, it will be rather difficult for the differential diagnosis of aortic arch disarticulation and severe aortic arch coarctation.

Purpose To investigate the value of bedside ultrasonography for emergent patients in the diagnosis of vasa previa and umbilical cord prolapse. Materials and Methods The bedside ultrasonography data of 12 emergent cases of vasa previa and 18 emergent cases of umbilical cord prolapse were retrospectively analyzed for detection rate. Results Nine out of 12 emergent patients with vasa previa were detected by bedside ultrasonography;2 were misdiagnosed as umbilical cord prolapsed;and 1 patient who had missed diagnosis suffered fetal demise during vaginal labour. Fifteen out of 18 emergent patients with umbilical cord prolapse were detected by bedside ultrasonography;2 were misdiagnosed as vasa previa; and 1 missed diagnosis (no death case was reported). The detection rates for both groups of patients had no significant difference (P>0.05). Conclusion Bedside ultrasonography for emergent patients can visualize the traveling of vasa previa and umbilical cord prolapse so as to promptly provide evidence for clinical diagnosis and reduce perinatal mortality.

Purpose To analyze the ultrasound manifestation of ovarian malignant teratoma, and to evaluate its diagnostic value and explore reasons for its misdiagnosis. Materials and Methods A retrospective study was conducted on the ultrasound findings of 25 patients with ovarian malignant teratoma confirmed surgically and pathologically (22 with immature teratoma, 3 with teratoma with malignant transformation). Their ultrasound imaging features were summarized and the reasons for misdiagnosis were further analyzed. Results The ultrasound imaging of 22 immature teratoma cases were divided into three types, namely, predominant solid components, predominant fluid components and mixed components of fluid and solid. All displayed calcification-like strong echo scattering in the low echo;color Doppler showed rich blood signal, little signal or no blood flow signal. Preoperative ultrasound presented1 case of immature teratoma (4.5%), 8 cases of ovarian tumors (malignant) (36.4%) and 13 cases of other diagnosis (59.1%). As to the 3 cases of teratoma with malignant transformation, the ultrasound imaging showed 2 cases were composed by fluid and solid components and that 1 case was mature cystic teratoma;typical hypoecho suggested malignant transformation. Preoperative ultrasound did not present teratoma with malignant transformation. Conclusion The ultrasound findings of ovarian malignant teratoma seem to be complicated and variable;thus the preoperative diagnosis rate is low though it still shows certain characteristics.

Purpose To analyze the high-frequency sonographic images of lymph nodes in mesenteric lymphadenitis of different ages. Materials and Methods 139 children with mesenteric lymphadenitis (study group) and 60 normal children (control group) were divided into 1 to 5 years, 6 to 10 years and 11 to 15 years group, the characteristics of high-frequency ultrasound sonographic images were analyzed, accuracy of longitudinal diameter (L), transverse diameter (S), aspect ratio (L/S) and color Doppler blood flow signal classification for the prediction of mesenteric lymph nodes swelling were evaluated using receiver operating characteristic (ROC) curve. Results Mesenteric lymph nodes in the control group appeared as spindle shape with sparse blood flow signals, L, and L/S increased with age increasing (F=4.047, 9.586;P<0.05). Mesenteric lymph nodes in the study group displayed as oval or teardrop-shaped with rich blood flow signals, L, S and L/S did not change significantly with age increasing (F=0.184, 1.084, 2.083; P>0.05). Compared with the control group, blood flow signals were more abundant in all age groups of the study group, L and S were also significantly higher (L:t=-13.798,-12.813,-8.089;S:t= -8.212,-13.172,-9.606, P<0.01), only in the 1 to 5 years group statistically significant difference (t=-3.208, P<0.05) was showed between the two groups. From 1 to 5 years, the sensitivity and specificity for the judgment of lymph node swelling were 95.56%and 100.00%, respectively when using L=9.85 mm as a standard;from 6 to 10 years, the sensitivity and specificity for the judgment of lymph node swelling were 95.59%and 100.00%, respectively when using L=10.25 mm as a standard;from 11 to 15 years, the sensitivity and specificity for the judgment of lymph node swelling were 92.31%and 100.00%, respectively when using S=4.40 mm as a standard. Conclusion High-frequency ultrasound is able to display the location distribution and morphological characteristics of the mesenteric lymph nodes in children, and also to accurately measure the diameters and flow signal distribution of the lymph nodes, thus will provide valuable evidence for the diagnosis of pediatric mesenteric lymphadenitis.

Purpose To explore the diagnostic value of dynamic contrast-enhanced CT (DCE-CT) in the differential diagnosis of chromophobic renal cell carcinoma (CRCC) and renal oncocytoma (RO). Materials and Methods A retrospective study was carried out on the DCE-CT findings of 24 patients with pathologically-proved CRCCs and 17 patients with pathologically-confirmed ROs. The enhancement percentage (EP) and the enhancement index (EI) of both types of lesions were compared on corticomedullary phase and nephrographic phase. Results CRCCs on corticomedullary phase and nephrographic phase:EP (132.8±39.8)%and (99.2±32.5)%, respectively;EI 0.31±0.11 and 0.30±0.12, respectively. ROs on corticomedullary phase and nephrographic phase:EP (234.1±129.1)%and (195.4±87.1)%, respectively;EI 0.66±0.33 and 0.68±0.28, respectively. Both EP and EI of CRCCs and ROs showed statistical difference (P<0.05). As the threshold value of EI on nephrograhic phase was 0.44, the sensitivity was 82.4%, specificity was 91.7% and Youden index was 0.74. Conclusion Imaging features of DCE-CT, especially EI on nephrographic phase, are helpful in the differential diagnosis of CRCC and RO.