2016年 · 第50卷第07期

With the rapid development of clinical medicine and the renewal of disease diagnosis and treatment methods, medical imaging plays an increasingly important role in health examination, disease diagnosis and differential diagnosis, formulating treatment plan and judging prognosis. Image-guided clinical practice is gradually realized. As the era of precision medicine and medical big data approaches^[1]Medical imaging technology has also ushered in a new era of rapid development. "Internet plus Medical" is advancing rapidly, imaging consultation centers are gradually established, and remote network reporting and consultation of difficult cases will become the norm. Medical diagnosis and treatment are accurate, and imaging medicine takes precedence; Medical images are accurate, and examination technology takes precedence; Technical inspection is accurate, and inspection specifications are first. This medical quality assurance system has been widely recognized by clinical medicine and imaging medicine workers, and standardizing imaging examination technology is the key to ensuring accurate diagnosis and treatment.

Digital X-ray examination technology is the process of digital imaging and digital image processing on the basis of analog X-ray examination technology. Digital X-ray photography is faster than analog X-ray photography, the photographic parameters adopt automatic exposure technology, the width is large, the radiation dose is low, the image density resolution is high and the layers are rich, the imaging medium is a detector which can carry out digital photoelectric conversion, and can carry out many kinds of post-processing on the image, the digital image is helpful for transmission and consultation^[1]。 digital X-ray examination mainly includes computed radiography (CR) and digital radiography (DR). It is one of the commonly used imaging examination methods in hospitals^[2]And has spread to community and township medical institutions. In order to standardize the digital X-ray examination technology and ensure the image quality, relevant domestic experts referred to the latest guidelines and literatures of digital X-ray examination technology at home and abroad, and drafted this edition of the consensus on digital X-ray examination technology of commonly used parts of human body in combination with clinical practice.

Malignant biliary obstruction is mostly caused by malignant tumors of bile duct, gallbladder, pancreas and duodenal ampulla. Currently, self-expandable metallic stent (SEMS) implantation is the standard treatment for patients with unsurgically resectable malignant biliary obstruction with a life expectancy of more than 3 months. However, more than 50% of patients will reblock the stent within 6 to 8 months after surgery due to tumor progression, excessive biliary epithelial hyperplasia, and the formation of biliary mud in the stent^[1]。 In recent years, Habib^TMIntrabiliary radiofrequency ablation by EndoHPB catheter, as an important local treatment for tumor, has been gradually applied in clinic. However, there are relatively few clinical data, and there are some controversies about safe and effective radiofrequency parameter setting. Through animal experiments, the author evaluated the damage to biliary tract and adjacent organs caused by two kinds of radiofrequency ablation generators commonly used in clinic, namely RITA 1500X and ERBE VIO50C radiofrequency generators, under different radiofrequency parameter settings, which provided a reference for clinical treatment.

Male, 30 years old. Due to the physical examination, the left lung occupied the location, and the doctor was seen on March 16, 2015. Past health, no history of tumor, no abnormalities in routine physical examination and laboratory examination.

DWI can detect the diffusion movement of water molecules inside and outside living tissue cells, and its ADC has been used in the diagnosis and differential diagnosis of human tumors. With the deepening of the research on DWI theory, scholars believe that the traditional DWI sequence ADC value calculation model has certain limitations. First of all, the morphology of human tissue is complex, not single and uniform, the tumor tissue has obvious cellular and tissue atypia, and the b value does not show a single exponential model (linear) relationship with the attenuation of tissue signal intensity; Secondly, small b-value DWI imaging, tissue signal attenuation is correlated with tissue blood perfusion^[1,2]。 1986 Le Bihan et al.^[3]DWI imaging based on intravoxel incoherent motion (IVIM) is proposed for the first time. This technique uses multi-B-value scanning to calculate parameters reflecting tissue diffusion and microcirculatory blood perfusion through a bi-exponential model without the use of exogenous contrast agents. At present, the clinical application of IVIM in tumor diseases has become a hot research topic. The author reviews the application progress of IVIM in human tumor imaging diagnosis.

Cerebral collateral circulation refers to the bypass artery or arterial anastomosis network generated by the inability to meet the perfusion requirements of brain tissue when the intracranial blood supply artery is narrowed or occluded. Collateral circulation has important clinical significance as a compensatory route to maintain intracranial hemodynamic stability. Studies have shown that the excellent collateral circulation is significantly correlated with the outcome of cerebrovascular events. Good collateral circulation can improve the success rate of vascular recanalization, improve the reperfusion of ischemic area, reduce the volume of infarct area, reduce the risk of hemorrhagic transformation, and effectively improve the clinical prognosis^[1]And can reduce the recurrence rate of long-term stroke events in patients with chronic stenosis or occlusion^[2]。 Collateral circulation is divided into three grades, the first grade is Willis ring, the second grade is transophthalmic reflux and pial artery anastomosis, and the third grade is neovascular. When acute or chronic stenosis and occlusion of the intracranial supply artery occurs, the primary collateral circulation is opened first. If the primary collateral circulation cannot provide sufficient blood perfusion, secondary and tertiary collateral vessels will be established^[3,4]。