3.0T磁共振弥散张量成像技术对轻度脊髓型颈椎病的诊断价值

目的:评价3.0T磁共振弥散张量成像技术(diffusion tensor imaging,DTI)对轻度脊髓型颈椎病的诊断价值及可行性。方法:应用3.0T高场强磁共振DTI成像序列,观察22例健康志愿者88个节段(A组)和69例轻度脊髓型颈椎病患者(依据颈髓MRI平扫结果分B、C两组,B组39例患者,硬膜囊98个节段受压、颈髓信号正常;C组30例患者,颈髓65个节段受压、颈髓信号正常)颈髓的表观扩散系数(apparentdiffusioncoefficient,ADC)及分数各向异性值(fractional anisotropy,FA),分析3组颈髓ADC值、FA值之间差异。结果:A组(C3/C4、C4/C5、C5/C6、C6/C7)共88个节段之间ADC值及FA值差异无显著性(P>0.05),故合并88个椎体数据;A、B及C组ADC值分别为0.91±0.34、1.17±0.35及1.32±0.36,组间比较,ADC值A组最低,B组次之,C组最高(P值均<0.05);三组平均FA值分别为0.71±0.16、0.62±0.15及0.54±0.14,A组最高,B组次之,C组最低(P值均<0.05)。结论:颈髓DTI较常规MRI能够早期、准确地量化轻度脊髓型颈椎病的颈髓微结构改变,可以为临床医生更早诊断治疗轻度脊髓型颈椎病提供有利的影像学依据。     

基于Web3.0的图书馆服务创新

介绍了Web3.0及其对图书馆的影响,并从智能化搜索服务、个性化图书馆门户等方面论述了Web3.0下图书馆的服务创新.     

我院PACS系统的应用

本文介绍了我院影像科PACS系统架构、功能、特点,总结了对PACS系统的应用管理方法和日常维护经验,并在此基础上进一步扩展PACS系统的使用功能.     

致密型乳腺良恶性结节MRI表现与CK5／6等的相关性研究

目的探讨致密型乳腺良恶性结节的MRI图像,并分析其与CK5／6、P63、Ki67等指标的相关性。方法应用3．0T MRI检查的36例致密型乳腺患者的41个结节,在ABVS（自动全容积成像）超声引导下穹剌,做常规病理与免疫组化检查。结果（1）乳腺良性结节多为圆形或粪圆形,边缘光滑,边界清楚,T1WI等或低信号,T2WI等或稍高信号,内部信号多均匀：恶性结节多呈不规则形,边缘不清,多可见毛刺征,大部病灶在T1WI呈略低信号,在T2WI呈不均匀高信号,内部信号多不均匀。（2）结节的数目、大小与CK5／6、P63、Ki67均未见相关性：结节的形状、边缘、信号均匀性与CK5／6、P63呈负相关,与Ki67呈正相关性。结论乳腺结节的MRI表现与CK5／6、P63、Ki67的表达具有相关性,可做为对其生物学行为及评估预后、指导临床治疗方案的依据。     

Effect of water on exenatide acylation in poly(lactide-co-glycolide) microspheres

Peptide or protein degradation often occurs when water flows into the dosage form. The aim of this study was to investigate the effect of water on exenatide acylation in poly(lactide-co-glycolide) (PLGA) microspheres. Exenatide-loaded PLGA microspheres were incubated at different relative humidities (RH) as well as in solutions of different pH for 20 days. The stability of exenatide was monitored using HPLC and HPLC–MS analysis. The alteration of exenatide conformation caused by water was investigated by FT-IR spectroscopy. Exenatide and glycolide were incubated in DMSO–water solutions to verify the effect of exenatide conformation state on the peptide acylation. Exenatide was relatively stable in microspheres at lower RH, and the absorbed water could act as a plasticizer and thus promote the peptide acylation by PLGA. However, when the microspheres were incubated at 100% RH, the excessively absorbed water could cause conformation recovery of exenatide and play an inhibitory effect on acylation. The formation of acylated exenatide incubated in acetate buffer saline of pH 6.0 was more than that of pH 4.5 and 3.0. Stability studies of exenatide in glycolide solutions showed that exenatide in nonnative monomer state was easier to be acylated by eletrophiles than that in aggregation state.     

Impact of field strength and RF excitation on abdominal diffusion-weighted magnetic resonance imaging

AIM:To retrospectively and prospectively compare diffusion-weighted(DW)images in the abdomen in a1.5T system and 3.0T systems with and without twochannel functionality for B1shimming.METHODS:DW images of the abdomen were obtained on 1.5T and 3.0T(with and without two-channel functionality for B1shimming)scanners on 150 patients(retrospective study population)and 10 volunteers(prospective study population).Eight regions were selected for clinical significance or artifact susceptibility(at higher field strengths).Objective grading quantified signal-to-noise ratio(SNR),and subjective evaluation qualified image quality,ghosting artifacts,anddiagnostic value.Statistical significance was calculated usingχ2tests(categorical variables)and independent two-sided t tests or Mann-Whitney U tests(continuous variables).RESULTS:The 3.0T using dual-source parallel transmit(dpTX 3.0T)provided the significantly highest SNRs in nearly all regions.In regions susceptible to artifacts at higher field strengths(left lobe of liver,head of pancreas),the SNR was better or similar to the 1.5T system.Subjectively,both dpTX 3.0T and 1.5T systems provided higher image quality,diagnostic value,and less ghosting artifact(P<0.01,most values)compared to the 3.0T system without dual-source parallel transmit(non-dpTX 3.0T).CONCLUSION:The dpTX 3.0T scanner provided the highest SNR.Its image quality,lack of ghosting,and diagnostic value were equal to or outperformed most currently used systems.     

我院PACS系统的应用

本文介绍了我院影像科PACS系统架构、功能、特点,总结了对PACS系统的应用管理方法和日常维护经验,并在此基础上进一步扩展PACS系统的使用功能。     

Imaging artifacts at 3.0T

Clinical MRI at a field strength of 3.0T is finding increasing use. However, along with the advantages of 3.0T, such as increased SNR, there can be drawbacks, including increased levels of imaging artifacts. Although every imaging artifact observed at 3.0T can also be present at 1.5T, the intensity level is often higher at 3.0T and thus the artifact is more objectionable. This review describes some of the imaging artifacts that are commonly observed with 3.0T imaging, and their root causes. When possible, countermeasures that reduce the artifact level are described.     

3D-T1rho quantitation of patellar cartilage at 3.0T

PURPOSE: To demonstrate the feasibility of three-dimensional (3D) T(1rho)-weighted imaging of human knee joint at 3.0T without exceeding the specific absorption rate (SAR) limits and the measurement of the baseline T(1rho) values of patellar cartilage and several muscles at the knee joint. MATERIALS AND METHODS: 3D gradient-echo sequence with a self-compensating spin-lock pulse cluster of 250 Hz power was used to acquire 3D-T(1rho)-weighted images of the knee joint of five healthy subjects. Global and regional analysis of patellar cartilage T(1rho) were performed. Furthermore, T(1rho) of several periarticular muscles were analyzed. RESULTS: The global average T(1rho) value of the patellar cartilage varied from 39 to 43 msec. The regional average T(1rho) values varied from 38 to 42 msec, and from 42 to 44 msec for medial and lateral facets, respectively. In vivo reproducibility of average T(1rho) of patellar cartilage was found to be 5% (coefficient of variation). Similarly, the global average T(1rho) values for biceps femoris, lateral gastrocnemius, medial gastrocnemius, and sartorius varied between 31-46, 29-49, 35-48, and 32-50 msec, respectively. CONCLUSION: We demonstrated the feasibility of 3D-T(1rho)-weighted imaging of the knee joint at 3.0T without exceeding SAR limits.