Optimization of Exposure Conditions for Computed Radiology Exams in Neonatal Intensive Care

This paper performs a review of existing literature about neonatal imaging in intensive care;we notice that the multiplicity of approaches results in different and sometimes conflicting solutions to optimize acquisition technique of X-ray images. European Guidelines still refer to screen-film combinations used in past decades, current usage of digital technology requires an additional effort to reduce dose to infants and to optimize the sensor’s response exploiting their properties. In this work we investigate response changes of digital medium (computed radiography plates), due to alterations of the beam through incubators components. All combinations in use in our Hospital were tested for evaluating dosimetry and image quality and new exposure solutions were devised to optimize radiology exams, taking into account solutions suggested by the equipments makers. Dose measured was compared with dose levels suggested by European Guidelines, evaluating radiation-induced risk too. Image quality was evaluated in a double-blind comparison by radiologists. An easily repeatable optimization procedure is proposed intended to reduce delivered dose well below European guidelines. The proposed study allowed us to instruct the technologists on the most appropriate methodology for performing the radiology exam, by standardizing the approach to Neonatal Intensive Care Units. We have demonstrated also to radiologic technologists reluctant to use the X-ray tray, as it may optimize imaging in the incubator. We were also able to reduce dose—and radiation-induced risk too—of 37% - 67% depending on the previously used operating mode.

Recent advances in computerized imaging and its vital roles in liverdisease diagnosis, preoperative planning, and interventional liversurgery: A review

The earliest and most accurate detection of the pathological manifestations of hepatic diseases ensures effective treatments and thus positive prognostic outcomes.In clinical settings,screening and determining the extent of a pathology are prominent factors in preparing remedial agents and administering approp-riate therapeutic procedures.Moreover,in a patient undergoing liver resection,a realistic preoperative simulation of the subject-specific anatomy and physiology also plays a vital part in conducting initial assessments,making surgical decisions during the procedure,and anticipating postoperative results.Conventionally,various medical imaging modalities,e.g.,computed tomography,magnetic resonance imaging,and positron emission tomography,have been employed to assist in these tasks.In fact,several standardized procedures,such as lesion detection and liver segmentation,are also incorporated into prominent commercial software packages.Thus far,most integrated software as a medical device typically involves tedious interactions from the physician,such as manual delineation and empirical adjustments,as per a given patient.With the rapid progress in digital health approaches,especially medical image analysis,a wide range of computer algorithms have been proposed to facilitate those procedures.They include pattern recognition of a liver,its periphery,and lesion,as well as pre-and postoperative simulations.Prior to clinical adoption,however,software must conform to regulatory requirements set by the governing agency,for instance,valid clinical association and analytical and clinical validation.Therefore,this paper provides a detailed account and discussion of the state-of-the-art methods for liver image analyses,visualization,and simulation in the literature.Emphasis is placed upon their concepts,algorithmic classifications,merits,limitations,clinical considerations,and future research trends.

胶原涂层上化学偶联抗DNA抗体的可行性

目的研究抗DNA抗体化学偶联到冠脉支架胶原涂层膜上的可行性及连接的稳定性。方法采用氯胺-T法对抗DNAIgM进行125I标记,将胶原膜随机分为化学偶联组(n=3)和对照组(n=3)J化学偶联组胶原膜用N-琥珀酰亚胺基-3-(2-吡啶基二硫)代丙酸酯(SPDP)通过化学键结合标记IgM,对照组胶原膜通过吸附的方式携带标记的IgM,测定125I的放射活性,评价IgM与胶原膜化学偶联的可行性及稳定性。结果化学偶联组胶原膜上携带的抗体量约为对照组的15倍,与对照组相比差异具有显著性(P<0.01);胶原膜通过化学偶联的方式携带抗体的稳定性明显优于对照组,在37℃60r/min摇动条件下洗脱,对照组胶原膜上携带的抗体仅5d即随胶原膜完全溶解而全部释放,而化学偶联组胶原膜携带的抗体在第16天时仍有25%保留在膜上。结论通过同位素标记定量显示了在蛋白涂层上通过化学偶联的方法连接抗DNA抗体的可行性和稳定性,为下一步冠状动脉血管支架上携带质粒DNA提供了实验依据。

肾小嗜酸细胞腺瘤多层螺旋CT双期扫描节段性增强反转的特异性表现

目的 回顾性研究多层螺旋CT双期扫描肾皮髓质期（CMP）与分泌早期（EEP）肾脏节段性增强反转对鉴别肾小嗜酸细胞腺瘤与肾细胞癌（RCC）的意义。材料与方法此项研究经学术委员会批准，免除知情同意通知。自2004年1月-2006年12月，共98例病理证实小于4cm的肾肿瘤（10例肾嗜酸细胞腺瘤与88例RCC）纳入研究。

Imaging and radiological interventions in extra-hepatic portal vein obstruction

Extrahepatic portal vein obstruction(EHPVO) is a primary vascular condition characterized by chronic long standing blockage and cavernous transformation of portal vein with or without additional involvement of intrahepatic branches, splenic or superior mesenteric vein. Patients generally present in childhood with multiple episodes of variceal bleed and EHPVO is the predominant cause of paediatric portal hypertension(PHT) in developing countries. It is a pre-hepatic type of PHT in which liver functions and morphology are preserved till late. Characteristic imaging findings include multiple parabiliary venous collaterals which form to bypass the obstructed portal vein with resultant changes in biliary tree termed portal biliopathy or portal cavernoma cholangiopathy. Ultrasound with Doppler, computed tomography, magnetic resonance cholangiography and magnetic resonance portovenography are non-invasive techniques which can provide a comprehensive analysis of degree and extent of EHPVO, collaterals and bile duct abnormalities. These can also be used to assess in surgical planning as well screening for shunt patency in post-operative patients. The multitude of changes and complications seen in EHPVO can be addressed by various radiological interventional procedures. The myriad of symptoms arising secondary to vascular, biliary, visceral and neurocognitive changes in EHPVO can be managed by various radiological interventions like transjugular intra-hepatic portosystemic shunt, percutaneous transhepatic biliary drainage, partial splenic embolization, balloon occluded retrograde obliteration of portosystemic shunt(PSS) and revision of PSS.

Xanthogranulomatous cholecystitis: What every radiologist should know

Xanthogranulomatous cholecystitis(XGC) is an uncommon variant of chronic cholecystitis characterized by xanthogranulomatous inflammation of the gallbladder. Intramural accumulation of lipid-laden macrophages and acute and chronic inflammatory cells is the hallmark of the disease. The xanthogranulomatous inflammation of the gallbladder can be very severe and can spill over to the neighbouring structures like liver, bowel and stomach resulting in dense adhesions, perforation, abscess formation, fistulous communication with adjacent bowel. Striking gallbladder wall thickening and dense local adhesions can be easily mistaken for carcinoma of the gallbladder, both intraoperatively as well as on preoperative imaging. Besides, cases of concomitant gallbladder carcinoma complicating XGC have also been reported in literature. So, we have done a review of the imaging features of XGC in order to better understand the entity as well as to increase the diagnostic yield of the disease summarizing the characteristic imaging findings and associations of XGC. Among other findings, presence of intramural hypodense nodules is considered diagnostic of this entity. However, in some cases, an imaging diagnosis of XGC is virtually impossible. Fine needle aspiration cytology might be handy in such patients. A preoperative counselling should include possibility of differential diagnosis of gallbladder cancer in not so characteristic cases.

CT灌注成像作为预测胰腺癌联合放化疗疗效的无创替代指标

目的 前瞻性研究CT灌注成像参数，如血浆与细胞外血管外间（EES）的容积转换常数（Ktrans）以及根据动态CT数据计算出的血容量，能否用于预测胰腺癌联合放化疗（CCRT）的疗效。方法 本研究经过审查委员会批准，并获知情同意。30例胰腺癌病人在接受以吉西他宾为基础的放化疗前行64层螺旋CT灌注扫描，分别于第3、6个月行CT随访，

Imaging and interventions in Budd-Chiari syndrome

Budd-Chiari syndrome(BCS) consists of a group of disorders with obstruction of hepatic venous outflow leading to increased hepatic sinusoidal pressure and portal hypertension.Clinically,two forms of disease(acute and chronic) are recognized.Mostly the patients present with ascites,hepatomegaly,and portal hypertension.In acute disease the liver is enlarged with thrombosed hepatic veins(HV) and ascites,whereas in the chronic form of the disease there may be membranous occlusion of HV and/or the inferior vena cava(IVC),or there may be short or long segment fibrotic constriction of HV or the suprahepatic IVC.Due to advances in radiological interventional techniques and hardware,there have been changes in the management protocol of BCS with surgery being offered to patients not suitable for radiological interventions or having acute liver failure requiring liver transplantation.The present article gives an insight into various imaging findings and interventional techniques employed in the management of BCS.

Effect of Gengnianchun Recipe (更年春方) on Bone Mineral Density, Bone Biomechanical Parameters and Serum Lipid Level in Ovariectomized Rats

Objective： To observe the effect of Gengnianchun Recipe （更年春方, GNC） on bone mineral density （BMD）, bone biomechanical parameters and serum lipid level in the bilaterally ovariectomized （OVX） rats and to explore the prophylactic and therapeutic action of GNC on ovariectomy induced osteoporosis and hyperlipidemia. Methods： OVX SD rats, 10- 12 months old, were divided into different groups and fed with GNC 2 g/d, GNC 1 g/d and Nilestriol 0. 125 mg/week, respectively for 4 months to observe the change of BMD and bone biomechanical parameters of the lumbar vertebrae, and the serum levels of total cholesterol （TO）, triglyceride（TG）, high-density lipoprotein cholesterol （HDL-C） and low-density lipoprotein cholesterol （LDL-C）, and to compare the effect of the two drugs on the morphology of the uterus. Results： There was marked reduction in BMD and biomechanical parameters in lumbar vertebrae （ P〈0. 01 ） and increase of serum TO and LDL-C levels （ P〈0. 01 ） in rats after OVX. GNC or Nilestriol significantly improved the decreased BMD and biomechanical parameters of the lumbar vertebrae （ P〈0.05 or P〈0. 01 ）, and reduced the serum TO and LDL-C levels （ P〈0. 01 ）. In the Nilestriol group, the wet weight of uterus got increased obviously （ P〈0.01 ）, the number of uterine glands increased, uterine columnar epithelium thickened, and the mitotic figures in the epithelial stroma and myointimal cells augmented. But no such effect in wet weight and morphology of uterus was found in the GNC group. Conclusion： GNC could increase the BMD and biomechanical parameters of the lumbar vertebrae, reduce the serum TO and LDL-C levels, yet produce no adverse reaction in stimulating proliferation and hypertrophy of uterus.

肝脏动脉增强分数的定量CT彩图检出肝细胞癌

目的 探讨肝脏动脉增强分数（AEF）的定量测定和三维彩图在检出肝细胞癌中的诊断价值。方法 本回顾性研究获机构审查委员会批准，免除知情同意书。82例病人[平均年龄：（56．2±10．0）岁]因肝癌或肝硬化行多期多层螺旋CT扫描随访，其中男69例[平均年龄：（57．1±10.0）岁]，女13例[平均年龄：（51．6±13．6）岁]。

Selective embolization for bleeding visceral artery pseudoaneurysms in patients with pancreatitis

BACKGROUND:Pancreatitis is associated with arterial complications in 4%-10%of patients,with untreated mortality approaching 90%.Timely intervention at a specialist center can reduce the mortality to 15%.We present a single institution experience of selective embolization as first line management of bleeding pseudoaneurysms in pancreatitis. METHODS:Sixteen patients with pancreatitis and visceral artery pseudoaneurysms were identified from searches of the records of interventional angiography from January 2000 to June 2007.True visceral artery aneurysms and pseudoaneurysms arising as a result of post-operative pancreatic or biliary leak were excluded from the study. RESULTS:In 50%of the patients,bleeding complicated the initial presentation of pancreatitis.Alcohol was the offending agent in 10 patients,gallstones in 3,trauma,drug-induced and idiopathic pancreatitis in one each.All 16 patients had a contrast CT scan and 15 underwent coeliac axis angiography. The pseudoaneurysms ranging from 0.9 to 9.0 cm affected the splenic artery in 7 patients:hepatic in 3,gastroduodenal and right gastric in 2 each,and left gastric and pancreatico-duodenal in 1 each.One patient developed spontaneous thrombosis of the pseudoaneurysm.Fourteen patients had effective coil embolization of the pseudoaneurysm.One patient needed surgical exclusion of the pseudoaneurysm following difficulty in accessing the coeliac axis radiologically.There were no episodes of re-bleeding and no in-hospital mortality. CONCLUSIONS:Pseudoaneurysms are unrelated to the severity of pancreatitis and major hemorrhage can occur irrespective of their size.Co-existent portal hypertension and sepsis increase the risk of surgery.Angiography and selective coil embolization is a safe and effective way to arrest the hemorrhage.

State-of-the-art preoperative staging of gastric cancer by MDCT and magnetic resonance imaging

Gastric cancer is one of the most common and fatal cancers. The importance of accurate staging for gastric cancer has become more critical due to the recent introduction of less invasive treatment options, such as endoscopic mucosal resection or laparoscopic surgery. The tumor-node-metastasis staging system is the generally accepted staging system for predicting the prognosis of patients with gastric cancer. Multidetector row computed tomography (MDCT) is a widely accepted imaging modality for the preoperative staging of gastric cancer that can simultaneously assess locoregional staging, including the gastric mass, regional lymph nodes, and distant metastasis. The diagnostic performance of MDCT for T- and N-staging has been improved by the technical development of isotropic imaging and 3D reformation. Although magnetic resonance imaging (MRI) was not previously used to evaluate gastric cancer due to the modality&#x02019;s limitations, the development of high-speed sequences has made MRI a feasible tool for the staging of gastric cancer.

Role of diffusion-weighted magnetic resonance imaging in the differential diagnosis of focal hepatic lesions

AIM： To evaluate the utility of diffusion-weighted imaging （DWl） in screening and differential diagnosis of benign and malignant focal hepatic lesions. METHODS： Magnetic resonance imaging （MRI） examinations were performed using the Signa Excite Xl Twin Speed 1.5T system （GE Healthcare, Milwaukee, Wl, USA）. Seventy patients who had undergone MRI of the liver [29 hepatocellular carcinomas （HCC）, four cholangiocarcinomas, 34 metastatic liver cancers, 10 hemangiomas, and eight cysts] between April 2004 and August 2008 were retrospectively evaluated. Visualization of lesions, relative contrast ratio （RCR）, and apparent diffusion coefficient （ADC） were compared between benign and malignant lesions on DWl. Su- perparamagnetic iron oxide （SPIO） was administered to 59 patients, and RCR was compared pre- and postadministration.RESULTS： DWI showed higher contrast between malignant lesions （especially in multiple small metastatic cancers） and surrounding liver parenchyma than did contrast-enhanced computed tomography. ADCs （mean±SD × 10^-3 mm2/s） were significantly lower （P 〈 0.05） in malignant lesions （HCC： 1.31 ± 0.28 and liver metastasis： 1.11 ± 0.22） and were significantly higher in benign lesions （hemangioma： 1.84 ± 0.37 and cyst： 2.61 ± 0.45） than in the surrounding hepatic tissues. RCR between malignant lesions and surrounding he- patic tissues significantly improved after SPIO administration, but RCRs in benign lesions were not improved.CONCLUSION： DWI is a simple and sensitive method for screening focal hepatic lesions and is useful for differential diagnosis.

Intraoperative perfusion magnetic resonance imaging: Cutting-edge improvement in neurosurgical procedures

The goal in brain tumor surgery is to remove the maxi-mum achievable amount of the tumor, preventing damage to "eloquent" brain regions as the amount of brain tumor resection is one of the prognostic factors for time to tumor progression and median survival. To achieve this goal, a variety of technical advances have been in-troduced, including an operating microscope in the late 1950 s, computer-assisted devices for surgical navigation and more recently, intraoperative imaging to incorporate and correct for brain shift during the resection of the lesion. However, surgically induced contrast enhancement along the rim of the resection cavity hampers interpretation of these intraoperatively acquired magnetic resonance images. To overcome this uncertainty, perfusion techniques [dynamic contrast enhanced magnetic resonance imaging(DCE-MRI), dynamic susceptibility contrast magnetic resonance imaging(DSC-MRI)] have been introduced that can differentiate residual tumor from surgically induced changes at the rim of the resec-tion cavity and thus overcome this remaining uncer-tainty of intraoperative MRI in high grade brain tumor resection.

经皮射频消融术联合经皮肝静脉或门静脉阻断术治疗肝脏恶性肿瘤

目的前瞻性评价经皮射频消融术(radiofrequen-cy,RF)联合经皮暂时性球囊肝静脉或门静脉大分支阻断术治疗肝脏恶性肿瘤的可行性、有效性及并发症。

Comparison of CT and MRI for presurgical characterization of paraaortic lymph nodes in patients with pancreatico-biliary carcinoma

AIM:To determine the accuracy of computed tomography (CT) and magnetic resonance (MR) for presurgical characterization of paraaortic lymph nodes in patients with pancreatico-biliary carcinoma. METHODS:Two radiologists independently evaluated CT and MR imaging of 31 patients who had undergone lymphadenectomy (9 metastatic and 22 non-metastatic paraaortic nodes). Receiver operating characteristic (ROC) curve analysis was performed using a five point scale to compare CT with MRI. To re-define the morphologic features of metastatic nodes, we evaluated CT scans from 70 patients with 23 metastatic paraaortic nodes and 47 non-metastatic ones. The short axis diameter, ratio of the short to long axis, shape, and presence of necrosis were compared between metastatic and non-metastatic nodes by independent samples t-test and Fisher's exact test. P < 0.05 was considered statistically significant. RESULTS:The mean area under the ROC curve for CT (0.732 and 0.646, respectively) was slightly higher than that for MRI (0.725 and 0.598, respectively) without statistical significance (P = 0.940 and 0.716,respectively). The short axis diameter of the metastatic lymph nodes (mean = 9.2 mm) was significantly larger than that of non-metastatic ones (mean = 5.17 mm, P < 0.05). Metastatic nodes had more irregular margins (44.4%) and central necrosis (22.2%) than non-metastatic ones (9% and 0%, respectively), with statistical significance (P < 0.05). CONCLUSION:The accuracy of CT scan for the characterization of paraaortic nodes is not different from that of MRI. A short axis-diameter (> 5.3 mm), irregular margin, and presence of central necrosis are the suggestive morphologic features of metastatic paraaortic nodes.

肝脏射频消融治疗:根据MRI铁羧葡胺廓清能力受损检测射频消融缘的可行性研究

本研究经过机构审查委员会批准，病人知情同意。目的是在肝脏射频消融术后，根据铁羧葡胺廓清能力受损情况，通过MRI显示肿瘤周围被烧蚀肝实质（消融缘）的可行性。21例肝癌病人在铁羧葡胺增强MRI后2～7h进行射频消融术。3～5d后的平扫T2＊WI上，消融缘表现为低信号环。消融缘的表现与肿瘤残余率或复发率具有相关性。本技术在肝脏射频消融术后是可行的，能够显示消融缘，并可预测肿瘤残余或复发。

Choledochocele with pancreas divisum:A rare cooccurrence diagnosed on magnetic resonance cholangiopancreatography

We report a case of a 42-year-old male with symptomatic choledochocele and incidental pancreas divisum diagnosed with magnetic resonance cholangiopancreatography (MRCP). Small choledochocele is rare congenital malformation associated with non-specific symptoms and a delay in diagnosis. The coexistence of choledochocele and pancreas divisum is extremely rare with only two case reports published in literature. In both cases MRCP failed to diagnose any biliary or pancreatic abnormality. This case suggests that the patients with recurrent abdominal pain and pancreas divisum should not be presumed to be suffering from pancreatitis. Careful evaluated for additional anomalies in the biliary tree should be sought for refractory symptoms. MRCP is a useful one-stop-shop for diagnosing pancreatic and biliary ductal anomalies.

Generation of functional hepatocyte-like cells from human bone marrow mesenchymal stem cells by overexpression of transcription factor HNF4α and FOXA2

Background: Our previous study showed that overexpression of hepatocyte nuclear factor 4α(HNF4α) could directly promote mesenchymal stem cells(MSCs) to differentiate into hepatocyte-like cells. However, the efficiency of hepatic differentiation remains low. The purpose of our study was to establish an MSC cell line that overexpressed HNF4α and FOXA2 genes to obtain an increased hepatic differentiation efficiency and hepatocyte-like cells with more mature hepatocyte functions. Methods: Successful establishment of high-level HNF4α and FOXA2 co-overexpression in human induced hepatocyte-like cells(hi Hep cells) was verified by flow cytometry, immunofluorescence and RT-PCR. Measurements of albumin(ALB), urea, glucose, indocyanine green(ICG) uptake and release, cytochrome P450(CYP) activity and gene expression were used to analyze mature hepatic functions of hi Hep cells. Results: hi Hep cells efficiently express HNF4α and FOXA2 genes and proteins, exhibit typical epithelial morphology and acquire mature hepatocyte-like cell functions, including ALB secretion, urea production, ICG uptake and release, and glycogen storage. hi Hep cells can be activated by CYP inducers. The percentage of both ALB and α-1-antitrypsin(AAT)-positive cells was approximately 72.6%. The expression levels of hepatocyte-specific genes( ALB, AAT, and CYP1A1) and liver drug transport-related genes( ABCB1, ABCG2, and SLC22A18) in hi Hep cells were significantly higher than those in MSCs-Vector cells. The hi Hep cells did not form tumors after subcutaneous xenograft in BALB/c nude mice after 2 months. Conclusion: This study provides an accessible, feasible and efficient strategy to generate hi Hep cells from MSCs.

单侧小肾细胞癌射频消融术与保肾手术的效价比分析

目的评价经皮射频消融术（RF）与保留肾单位手术（NSS）治疗小的（直径≤4cm）肾细胞癌的相对成本效益，制定出社会希望支付，普遍可接受的费用水平。方法建立马尔可夫（Markov）决策分析模型，评估接受射频消融或保肾手术的65岁组小肾细胞癌病人的预期寿命及相关花费。模型的建立考虑到了肾癌的状况、治疗效果、费用及近期和远期疗效等综合因素。在假定每个质量校正生存年（QALY）费用为75000美元的前提下，分析判定优选治疗方案如何能提高性价比。在预期范围内引导完善的新式医疗保健干预措施。用敏感性来反映主要参数的变化结果。结果通过运用案例假设，NSS后有质量的生活时间略长于RF（2．5d），