磁共振扩散张量成像诊断曲棍球运动员髌软骨早期损伤

目的 探讨应用磁共振扩散张量成像(DTI)诊断曲棍球运动员髌软骨早期损伤的可行性。方法 对40名非运动员(正常组)和17例专业曲棍球运动员(运动组)的双膝关节行质子密度加权成像(PDWI)和DTI扫描,生成DTI伪彩图,于连续两个髌软骨最大层面上选择5个ROI(内侧、偏内侧、中间、偏外侧、外侧),测量各ROI的各向异性分数(FA)和平均弥散系数(MD),并进行比较。结果 与正常组比较,运动组右侧髌软骨各部位的FA值减小,MD值增加,差异均有统计学意义(P均<0.001);左侧髌软骨上层偏外侧、外侧及下层偏外侧MD值增加,差异有统计学意义(P均<0.005)。运动组左、右髌软骨各部位的FA和MD值差异有统计学意义(P均<0.05)。运动组右侧髌软骨的上层内侧与外侧MD值的差异有统计学意义(F=7.02, P=0.012)。结论 FA值和MD值能够体现髌软骨水分子弥散能力的变化,量化髌软骨早期损伤的生化改变。DTI技术可以对曲棍球运动员髌软骨不同程度早期损伤的诊断提供影像学依据。     

男性痛风合并轻度认知功能障碍患者海马MR扩散张量成像的定量分析

目的 探讨海马区DTI在男性痛风合并轻度认知功能障碍(MCI)患者中的应用价值。方法 病例组纳入男性痛风患者35例,其中痛风合并MCI(gout-MCI)亚组15例,痛风合并认知功能正常(gout-CN)亚组20例,记录病例组患者最高血尿酸水平及近5年平均血尿酸水平。另选取15名健康志愿者作为正常对照组。对所有受检者行简明精神状态检查量表(MMSE)及蒙特利尔认知评估量表(MoCA)评分后,行常规颅脑MR和DTI检查,测量并记录FA、ADC值,并进行统计学分析。结果 gout-MCI亚组患者近5年平均血尿酸水平低于gout-CN组患者(P<0.05)。gout-MCI亚组患者海马FA值低于gout-CN亚组及正常对照组(P<0.05),gout-MCI亚组患者海马ADC值高于gout-CN组及正常对照组(P<0.05)。gout-CN亚组患者海马FA值、ADC值与正常对照组差异无统计学意义(P>0.05)。gout-MCI亚组患者海马FA值与MoCA评分呈正相关(P<0.05),与MMSE评分无相关性,右侧海马ADC值与MoCA评分呈负相关(P=0.04)。结论 颅脑DTI技术可早期检测痛风合并MCI患者双侧海马的损伤。     

MR扩散张量成像评估高尿酸血症患者肾损伤

目的 探讨MR扩散张量成像评价高尿酸血症早期肾功能损伤的可行性。方法 收集23例男性无症状高尿酸血症（AH组）、30例痛风（GA组）患者及23名健康志愿者（HC组）。检测血清尿酸浓度（SUA），估算肾小球滤过率（eGFR）。行常规MRI及DTI，比较3组间肾皮、髓质表观扩散系数（ADC）值及各向异性（FA）值、SUA、eGFR差异，并分别分析其与SUA及eGFR的相关性；同时分析SUA与eGFR间的关系。结果 HC组SUA值低于AH组及GA组（P均<0.05），GA组eGFR低于HC组（P<0.05）。AH组与GA组肾皮质和髓质的FA值均低于HC组（P均<0.05）；AH组、GA组肾皮质ADC值和GA组肾髓质ADC值均低于HC组（P均<0.05）。肾皮、髓质FA值（r=-0.41、-0.40）及肾皮、髓质ADC值（r=-0.34、-0.28）与SUA均呈负相关（P均<0.05），而肾皮、髓质DTI各参数与eGFR无明显相关性；SUA与eGFR呈负相关（r=-0.43，P<0.05）。结论 DTI可用于评估高尿酸血症早期肾功能损伤；高尿酸血症肾皮质ADC值及肾皮、髓质FA值均低于正常人；肾皮、髓质ADC值及FA值与SUA均呈负相关，SUA与肾功能损伤程度呈正相关。     

MR T1ρ成像技术早期诊断膝骨性关节炎早期软骨损伤

目的 探讨MR T1ρ技术诊断早期骨性关节炎(OA)软骨损伤的临床应用价值。方法 纳入经临床和MRI确诊的OA患者75例及健康志愿者23名(对照组),进行常规MR及MR T1ρ成像。根据常规MRI表现,按Noyes分级将OA患者分为轻度OA组和重度OA组,比较不同OA组与对照组患者T1ρ值差异,分析年龄与T1ρ值的相关性。结果 膝关节T1ρ伪彩图对照组呈均一蓝色,轻度OA组呈斑片状绿色增高影,重度OA组色阶信号混杂。对照组、轻度OA组和重度OA组膝关节软骨平均T1ρ值为(39.18±2.05)ms、(44.00±3.33)ms和(47.57±3.57)ms,两两比较差异均有统计学意义(P均<0.05)。T1ρ值与年龄呈正相关(r=0.62,P<0.05)。结论 T1ρ成像可显示膝关节OA患者早期软骨损伤,有助于早期诊断OA。     

T1ρ技术定量评估踝关节距骨骨软骨损伤

目的 探讨采用T1ρ技术评估踝关节距骨骨软骨损伤（OLT）的可行性。方法 对40例踝关节损伤患者行常规MRI和T1ρ成像，之后1周内行关节镜检查。根据常规MRI、关节镜及T1ρ成像，依照Hepple改良分型标准将踝关节OLT分为Ⅰ~Ⅳ型（分别为Ⅰ~Ⅳ型组）。随机选取20例患者正常软骨区域为正常对照组，测量各组软骨T1ρ值，并分析其差异；比较常规MRI评估OLT分型与关节镜结果的一致性。结果 T1ρ成像可清晰显示踝关节距骨软骨，且不同损伤程度呈现不同色阶。随损伤程度加重，软骨T1ρ值逐渐延长。Ⅰ型组软骨T1ρ值[（43.07±2.05）ms）与Ⅱ型组[（45.24±2.19）ms]之间差异无统计学意义（P=0.12），其余各组间软骨T1ρ值差异均具有统计学意义（P<0.05）。常规MRI评估OLT分型与关节镜结果的一致性良好（Kappa=0.80，P<0.01）。结论 T1ρ技术可清晰显示踝关节距骨软骨，定量评估OLT，尤其适用于早期OLT患者。     

基于动脉自旋标记及DTI评价脑小血管病患者脑灌注及白质微结构变化

目的 应用动脉自旋标记（ASL）及DTI技术探讨脑小血管病（cSVD）患者常规扫描表现正常白质（NAWM）区脑灌注及白质微结构变化。方法 对23例cSVD患者（cSVD组）及13名年龄、性别匹配的健康志愿者（对照组）行常规MR、ASL及DTI检查,测量双侧额叶、顶叶、半卵圆中心、胼胝体膝部及压部常规扫描NAWM区的各向异性分数（FA）值、表观扩散系数（ADC）值、脑血流量（CBF）值,比较cSVD组与对照组间的差异,并进一步分析cSVD组FA值及ADC值与CBF值的相关性。结果 cSVD组双侧额叶、顶叶FA值较对照组减低,ADC值升高（P均<0.05）;双侧半卵圆中心FA值及右侧半卵圆中心CBF值均较对照组减低（P均<0.05）。双侧额叶、顶叶白质及右侧半卵圆中心的FA值与CBF呈正相关（r=0.51、0.46、0.22、0.27、0.33,P均<0.05）,双侧额叶ADC与CBF值呈负相关（r=-0.50、-0.38,P均<0.05）。结论 DTI能反映cSVD患者早期隐匿性脑白质损伤,以双侧额叶FA值改变最为明显。     

MR多角度屈曲观察髌股关节软骨损伤

目的 通过膝关节多角度屈曲MR扫描,观察膝关节炎髌股关节软骨损伤的位置,判断最容易引起髌股关节软骨损伤的运动角度,探讨膝关节的安全运动方式。方法 对22例骨关节炎患者的膝关节分别在伸直位和被动屈曲0°、10°、20°、30°、40°、50°、60°的状态下进行快速自旋回波质子加权像加脂肪抑制序列（PD-TSE-FS）扫描,矢状位图像上观察髌股关节软骨损伤的位置。结果 髌股关节软骨内T2WI信号异常4处,局限性软骨变薄20处,关节软骨局限性缺损12处。膝关节被动屈曲时,软骨损伤在30°~60°内均有对合情况,对合最多的角度为40°,在<30°屈曲角度扫描中仅发现1例软骨损伤对合的病例。结论 膝关节屈曲30°~60°时髌骨软骨与股骨滑车软骨损伤在对应面出现的频率最高。屈曲<30°时髌骨软骨与股骨滑车软骨损伤在对应面出现的频率较低。     

DTI检测正常人皮质脊髓束发育规律

目的 采用DTI检测正常人皮质脊髓束(CST)在大脑脚、内囊后肢及半卵圆中心发育的规律。方法 采集120名头部MRI无异常的门诊患者及健康志愿者颅脑DTI数据, 按年龄分为10组, 每组12名(男、女各6名), 测量大脑脚、内囊后肢及半卵圆中心CST的FA值及ADC值, 比较不同年龄组间FA值及ADC值差异, 分析FA值和ADC值与年龄的相关性。结果 不同年龄组间大脑脚、内囊后肢、半卵圆中心CST的FA和ADC值差异有统计学意义(P均 <0.05), FA值随年龄增长先升高后降低, ADC值先降低后升高。≤18岁受检者FA值与年龄呈正相关, ADC值与年龄呈负相关, >18岁受检者FA值与年龄呈负相关, ADC值与年龄呈正相关(P均 <0.05)。结论 DTI可反映CST微结构变化, 未成年阶段随年龄增长FA值升高、ADC值下降, 成年阶段随年龄增长FA值下降、ADC值升高。     

不同翻转角双回波稳态序列MRI评价膝关节骨性关节炎软骨损伤

目的 评估不同翻转角（FA）三维双回波稳态（3D-DESS）序列MRI对评价膝关节骨性关节炎软骨损伤的价值。方法 收集25例单侧膝关节疼痛患者，以FA 30°、60°及90° 3D-DESS序列采集膝关节MRI，评估每例患者髌骨（Pat）、股骨滑车（Tro）、股骨外侧髁（LFC）、股骨内侧髁（MFC）、胫骨外侧平台（LTP）及胫骨内侧平台（MTP）6个软骨情况，根据结果分为软骨损伤阳性（Ⅱ~Ⅳ级）和阴性（0、Ⅰ），对图像评价软骨损伤的诊断信心进行评分。以关节镜检查结果为标准，分析MRI结果与其的一致性。比较不同FA图像的诊断信心评分。结果 对于Pat、Tro、MFC、LFC、MTP、LTP，FA 90° 3D-DESS图像的结果与关节镜结果一致性较好（Kappa＝1.00、0.84、1.00、0.81、0.97、0.91，P均<0.01），但显示正常软骨结构欠佳；FA 60° 3D-DESS图像一致性较好或一般（Kappa＝0.87、0.61、0.81、0.74、0.73、0.68，P均<0.01），周围骨质及软组织显示较好；FA 30° 3D-DESS图像一致性一般或差（Kappa＝0.47、0.38、0.50、0.30、0.32、0.23，P均<0.01），但可清晰显示软骨结构。FA 30°图像诊断信心评分低于FA 60°（P均<0.05）及FA 90°图像（P均<0.01），FA 60°图像诊断信心评分低于FA 90°图像（P均<0.05）。结论 FA 90° 3D-DESS图像显示软骨损伤最佳，FA 30°清晰显示软骨形态及结构，而FA 60°能兼顾周围骨质及软组织，临床中应根据检查目的选择合适的FA。     

合成MRI及弥散张量成像评估成人胶质瘤级别与异柠檬酸脱氢酶-1状态

目的 观察合成MRI(SynMRI)及弥散张量成像(DTI)评估成人胶质瘤级别与异柠檬酸脱氢酶-1(IDH-1)状态的价值。方法 回顾性分析115例成人胶质瘤患者,根据WHO分类将其分为成人低级别胶质瘤(aLGG)组(n=44)及成人高级别胶质瘤(aHGG)组(n=71);aLGG组含30例IDH-1突变型、2例野生型及12例无法确定,aHGG组依次为26例、24例及21例。比较组间SynMRI及DTI参数,包括T1值、T2值、质子密度(PD)、表观弥散系数(ADC)及各向异性分数(FA),分析其鉴别aLGG与aHGG、IDH-1突变型与野生型的效能。结果 组间及aHGG组内IDH-1突变型与野生型的T1值、T2值、ADC及FA差异均有统计学意义(P均＜0.05);以上述参数鉴别aLGG与aHGG的曲线下面积(AUC)分别为0.731、0.686、0.930及0.710,鉴别aHGG组内IDH-1突变型与野生型的AUC分别为0.775、0.729、0.817及0.705,均以ADC的AUC最高(P均＜0.05)。结论 T1值、T2值、ADC及FA等SynMRI和DTI参数均有助于鉴别aLGG与aHGG、IDH-1突变型与野生型,尤以ADC效能最高。     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.