[en] To analyse diffusion-weighted MRI of acute spinal cord trauma and evaluate its diagnostic value. Conventional MRI and multishot, navigator-corrected DWI were performed in 20 patients with acute spinal cord trauma using 1.5-T MR within 72 h after the onset of trauma. Twenty cases were classified into four categories according to the characteristics of DWI: (1) Oedema type: ten cases presented with variable hyperintense areas within the spinal cord. There were significant differences in the apparent diffusion coefficients (ADCs) between lesions and unaffected regions (t = -7.621, P < 0.01). ADC values of lesions were markedly lower than those of normal areas. (2) Mixed type: six cases showed heterogeneously hyperintense areas due to a mixture of haemorrhage and oedema. (3) Haemorrhage type: two cases showed lesions as marked hypointensity due to intramedullary haemorrhage. (4) Compressed type (by epidural haemorrhage): one of the two cases showed an area of mild hyperintensity in the markedly compressed cord due to epidural haematoma. Muti-shot DWI of the spinal cord can help visualise and evaluate the injured spinal cord in the early stage, especially in distinguishing the cytotoxic oedema from vasogenic oedema. It can assist in detecting intramedullary haemorrhage and may have a potential role in the evaluation of compressed spinal cord. (orig.)

[en] The Prostate Imaging-Reporting and Data System (PI-RADS) Steering Committee modified the PI-RADS v 2.0 in 2019. The updated version is termed PI-RADS v 2.1. This article summarized and compared the two version in the following aspects: announcements and technical specifications of multi parametric MRI, assessment categories of transition zone, evaluation of lesions in the central zone and anterior fibromuscular stroma and commentary on bi-parametric MRI. (authors)

[en] Objective: To study the prostate volume of normal children and adolescents and to evaluate the development of prostate central zone and peripheral zone. To provide the preliminary MRI standards of prostate growth and development for normal Chinese children and adolescents. Methods: Five hundred and fifty eight healthy male volunteers, aged from 2 to 25 years were retrospectively analysed. They were divided into 5 groups by the ages (group A: 2 to 5 years, group B: 6 to 10 years, group C: 11 to 15 years, group D: 16 to 20 years and group E: 21 to 25 years). All the volunteers underwent conventional MRI examinations at our institution (T_2WI axial and coronal image acquisition). The prostate volume of different age groups were measured, the development of the central zone and peripheral zone were scored by two radiologists, and the data were treated by Nonparametric test. Results: Group A children's prostate nearly not development, only individual MRI measurable its size; Group B most not development, only 6 children visible prostate form, but can't distinguish the anatomical division; Group C prostate gland development better, MRI can measure the size, but distinguish its central and peripheral area is difficult ; Group D prostate gland development rapidly, differences are obvious, but only a few central and peripheral area boundary clear; Group E the central and peripheral area boundary clear, form full, T_2WI signal contrast clear. The median prostate volumes of 5 groups were 0.000, 0.000, 2.450, 7.990 and 10.600 cm"3, respectively (χ"2 = 215.452, P < 0.01). The median prostate scores of 5 groups were 0.04, 0.31, 1.34, 2.23 and 2.60, the prostate volumes were significant difference among these 5 groups except group A and group B (χ"2 = 127.460, P < 0.01), there were significant difference among the volumes and the scores of these five groups (P < 0.01). Conclusions: MRI provided the basis of objective and truth for the the measurements of volume and the observations of prostate development in this study, that offers preliminary reference range for normal Chinese children and adolescents prostate development status. (authors)

[en] Objective: To analyze the MR findings of vagal paraganglioma. Methods: Six cases of vagal paraganglioma (4 benign and 2 malignant) were retrospectively analyzed with the emphasis on the location, MR signal intensity, dislocation of the carotid vessels, and the metastasis of the tumor. Results: The tumors located in the superior (4 cases), middle (1 case) and infer/or (1 case) neck, respectively, with right-sided in 4 eases and left-sided in 2 cases. The signal intensities of the six tumors were heterogeneous, combined with salt and pepper appearance in 4 cases in which the pepper appearance was more marked. On MR angiography performed in 4 cases, carotid arteries were found dislocated anteriomedially. Two eases were diagnosed as malignancies by the manifestations of destruction of surrounding bone, metastasis of bilateral lungs and/or the lymph nodes. Conclusion: Vagal paragangliomas could be correctly diagnosed before surgery according to their locations and signal intensities. (authors)

[en] Pancreatic cancer is a tumor originated from the pancreatic exocrine tissue, mostly ductal adenocarcinoma. It shows characteristics of early concealment, high invasiveness, easy metastasis, and low survival rate. Its early diagnosis and treatment is still a challenge. In recent years, with the rapid development of MRI techniques, the MRI, especially the magnetic resonance diffusion weighted imaging, dynamic contrast enhanced MRI and spectrum, could provide a tool for us to further understand pancreatic cancer, and could significantly improve the sensitivity of lesion detection. It helpful in evaluating the pancreatic microcirculation perfusion and cell metabolism, can assess the response to the antiangiogenic therapy, and has become an important tool in clinical practice. (authors)

[en] Objective: To analyze the diffusion-weighted MR imaging findings in ischemic spinal cord lesions and discuss the value of diffusion-weighted MR imaging in differentiating diagnosis with inflammatory diseases and tumors. Methods: Six patients (2 male, 4 female) with typical sudden onset of neurological deficits caused by spinal cord ischemia were evaluated. There were no definite etiologies in all patients. DW imaging was performed within 1 to 30 days after the initial neurological symptoms using a Philips Gyroscan 1.5 TMR system. Four patients had other scans including contrast-enhanced MR imaging (CE-MRI) and/or FLAIR scans. Two of them followed up with MR images in three months. All six patients were imaged using a multi-shot, navigator-corrected, echo-planar pulse sequence, and ADC values were calculated in sagittal-oriented plane. Results: MR abnormalities were demonstrated on sagittal T₂-weighted images with 'patch-like' or 'strip-like' hyperintensities (6/6) and cord enlargement (5/6). Axial T₂-weighted images showed bilateral (6/6) hyperintensities. In one patient only the posterior spinal artery (PSA) territory was involved. Spinal cord was mainly affected at the cervical (2/6) and thoracolumbar (4/6) region, two of them included the conus medullaris (T10-L1). DW images showed high signals in all infarct lesions, degree of intensity depended on scanning time from ill-onset and progress of illness and whether companied with hemorrhage. In this group, except one case with closely normal ADC value due to one month course of illness, the five others ADC values of lesions calculated from ADC maps arranged from 0.23 x 10^-3 mm²/s to 0.47 x 10^-3 mm²/s [average value (0.37 ± 0.10) x 10^-3 mm²/s], markedly lower than normal parts [ average value (0.89 ± 0.08) x 10^-3 mm²/s]. There were marked difference between lesions and normal regions (t=4.71, P<0.01). Five cases had better contrast of signals in DW images than in T₂W images. Meanwhile, lesions could be displayed much better in DW images than in T₂W images because of CSF presenting low signals in DW images. Dynamic or repeated DWI examinations would be helpful for analyzing the degree of injury and recovery. Most lesions showed non-enhanced effects in CE-MRI except one lesion showed irregular slight enhancement. Conclusion: MR imaging is useful in detecting spinal cord infarction. DW imaging of the spinal cord may provide additional information for assessment of ischemic changes and help improve ability in differentiating diagnosis. (authors)

[en] Preoperative portal vein embolization (PVE) has become an important tool in the management of selected patients with hepatic cancer before the major hepatic resection is carried out. PVE can redirect the portal flow to the intended future remnant liver tissue in order to induce the hypertrophy of the non-diseased portion of the liver and thereby may reduce the occurrence of complications and shorten the hospitalization days after surgery. This article aims to review the technical and clinical considerations in performing PVE and to discuss the PVE-related practical points, including the relevant anatomy, the access approach,the choosing of embolic agents and the pathophysiology of PVE. In addition, the indications and contraindications for performing PVE, the use of combination therapies and the concern for tumor growth after PVE are also discussed. (authors)

[en] Objective: To evaluate the effect of intramyocardial administration of basic fibroblast growth factor on angiogenesis of infarcted myocardium in dogs. Methods: Twenty-four mongrel dogs were randomized into control group and therapeutic group. Acute myocardial infarction was made by ligation of the left anterior descending coronary artery distal to its first diagonal branch. As soon as coronary artery was occluded, 50 mg of basic fibroblast growth factor in 15 ml of saline was injected into the infarcted and border zone in therapeutic group, whereas 15 ml saline alone was used in the same way in control dogs. Every 3 dogs in each group was studied on the 1^st day, the 3^rd day, the 10^th day, and the 17^th day, respectively. Electron microscope was used to observe the growth of capillaries. Angiogenesis was evaluated by immunohistochemical studies with VIII factor. With sensitivity encoded technique, cine MR and MR perfusion imaging were performed on each dog within 3 hours after surgery and before euthanasia to evaluate cardiac function and the characteristics of myocardial perfusion. Results: In therapeutic group, LVEF improved markedly since the 10^th day (on the 10^th day: control group 24.09 ± 3.32, therapeutic group 45.71 ± 6.27; on the 17^th day: control group 31.46 ± 4.60, therapeutic group 53.46 ± 5.24). Hypoenhancement on first pass and hyperenhancement on delayed phase appeared in infarcted myocardium. There were significant differences for the time of upslope, peak time of signal intensity, upslope curves ratio, and contrast enhancement ratio between infarcted and normal myocardium. The size of infarcted myocardium was markedly decreased on the 17^th day [control group (9.04 ± 1.59)%, therapeutic group (4.07 ± 1.20)%]. The capillaries grew actively in therapeutic group and microvessel density was higher in therapeutic group than in control group except the first day (control group and therapeutic group respectively on the 3^rd day: 92.3 ± 11.6, 147.3 ± 11.6; on the 10^th day: 125.0 ± 12.1, 182.7 ± 14.0; on the 17^th day: 124.7 ± 14.5, 223.7 ± 19.9). Conclusion: Intramyocardial administration of basic fibroblast growth factor is useful in increasing the growth of microvessels, decreasing the size of the infarcted myocardium, and improving left ventricular function in acute myocardial infarction

[en] Objective: To evaluate the feasibility of transcatheter arterial chemoembolization (TACE) for advanced hepatocellular carcinoma (HCC) complicated by tumor thrombus in inferior vena cava and right atrium. Methods: The clinical data of 16 HCC patients complicated by tumor thrombus in inferior vena cava (n = 16) and right atrium (n = 4) who were treated with TACE were retrospectively analyzed. Hepatic arterial infusion of chemotherapeutic agents, including fluorouracil, mitomycin and pirarubicin, was carried out in all patients, which was followed by tumor-feeding artery chemoembolization with the mixture of pirarubicin, lipiodol and polyvinyl alcohol (PVA, 300 μm). The clinical results were analyzed. Results: The overall response rate of tumor thrombus was 68.7% (11/16). The median survival time of the entire group was 12 months (ranged from 2.6 to 26 months). The median survival time of the 11 patients who responded to the treatment (group A) was 13.5 months (ranged from 7.5 to 26 months), and the median survival time of the 5 patients who didn't respond to the treatment (group B) was 3.3 months (ranged from 2.6 to 12.5 months). The difference in the median survival time between the two groups was statistically significant (P < 0.01). No severe post-embolization complications occurred. Conclusion: For the treatment of advanced HCC complicated by tumor thrombus in inferior vena cava and right atrium, TACE is safe and effective. (authors)

[en] Objective: To compare the mechanical characteristics of blood clot models used for the evaluation of interventional thrombectomy devices for acute stroke, and to provide more scientific blood clot models for the manufacture of interventional thrombectomy devices. Methods: The Kan's and Gralla's radioparent tube clots model was duplicated. The spontaneous radioparent tube red clots (SNTR) and spontaneous radioparent tube of white clots (SNTW) were prepared. By bending testing and elongation testing the mechanical properties of clot models were evaluated. By using HE staining the organizational structure of the clot models was assessed. Software SAS9.3 was used to analyze the data. Results: SNSW (Kan model), TNTR (Gralla model), SNTR and SNTW were successfully prepared. The bending testing of the four radioparent clot models that carried quite different mechanical properties was separately performed at 24 hours, one and two weeks later. The results showed that the elasticity of SNSW was (5.00 ± 4.47), (4.16 ± 3.76) and (5.83 ± 6.64) degree respectively; the elasticity of TNTR was (19.33 ± 6.05), (16.66 ± 4.08) and (19.16 ± 9.70) degree respectively; the elasticity of SNTR was (10.00 ± 7.07), (7.50 ± 6.89) and (13.33 ± 4.08) degree respectively; and the elasticity of SNTW was (87.5 ± 2.73), (81.66 ± 6.83) and (88.33 ± 4.08) degree respectively. The elongation testing of the four radioparent clot models that carried quite different mechanical properties was separately performed at 24 hours, one and two weeks later. The results showed that the stretch limit of SNSW was (4.43 ± 0.38), (4.67 ± 0.29) and (4.60 ± 0.31) cm respectively; the stretch limit of TNTR was (3.79 ± 0.13), (3.91 ± 0.11) and (3.91 ± 0.16) cm respectively; the stretch limit of SNTR was (3.25 ± 0.15), (3.46 ± 0.10) and (3.33 ± 0.27) cm respectively; the stretch limit of SNTW was (4.22 ± 0.18), (4.40 ± 0.32) and (4.11 ± 0.15) cm respectively. Conclusion: SNSW, TNTR SNTR and SNTW are four clot models with different mechanical properties. It is reasonable that the use of one proper clot model or some of these clot models should be based on the purpose of the study. (authors)