对比观察髓内室管膜瘤及星形细胞瘤的MRI特征

目的 对比观察髓内室管膜瘤及星形细胞瘤的MRI特征,以提高诊断准确率。 方法 回顾性分析经手术病理证实的28例髓内室管膜瘤及12例星形细胞瘤的MRI及相关临床资料,对比分析二者MRI表现的差异。 结果 髓内室管膜瘤及星形细胞瘤的平扫MRI信号类似,T1WI呈等或低信号,T2WI以不均匀高信号为主。28例髓内室管膜瘤中,中心性膨胀性生长26例,边界清楚18例,21例可见瘤内及瘤周囊变,明显强化21例,均匀强化19例,4例出现"帽征"; 12例星形细胞瘤中,偏心性生长9例,边界不清9例,出现囊变5例,轻度强化8例,以斑片状及结节状强化为主。二者生长方式、肿瘤边界、强化程度及方式差异存在统计学意义(P<0.05)。 结论 MRI有助于鉴别诊断髓内室管膜瘤和星形细胞瘤。     

颅内原发性胶质肉瘤MRI表现及误诊分析

目的 分析颅内原发性胶质肉瘤的MRI表现特征,分析误诊原因。方法 回顾性分析经手术病理证实的12例颅内原发性胶质肉瘤的MRI、病理及临床表现。结果 12例肿瘤均位于幕上,大小不等,边界较清晰;10例T1WI肿瘤实质表现为低信号、T2WI高信号,2例T1WI、T2WI均呈等信号;FLAIR均呈高信号;肿瘤实质区DWI为高信号;增强扫描11例呈明显不均匀强化,1例为轻中度不均匀强化。本组 3例误诊为脑膜瘤,1例误诊为室管膜瘤,1例误诊为淋巴瘤,1例误诊为毛细胞星形细胞瘤。结论 胶质肉瘤的MRI表现具有一定特征。MRI能清楚显示病灶实质及周围水肿范围,有助于鉴别诊断及预后评估。     

硬膜外脊膜瘤的影像学表现

目的 观察扁平形硬膜外脊膜瘤的影像学表现。方法 回顾性分析8例经手术病理证实的扁平形硬膜外脊膜瘤的影像学表现表现,并进行文献复习。结果 7例硬膜外脊膜瘤位于颈椎管,1例位于胸椎管,累及2~4个椎体节段;8例病灶均呈扁平形、以增厚的硬膜为基底,伴硬膜外肿块形成;5例肿瘤经椎间孔向硬膜外延伸、相应水平椎间孔扩大;椎管均均匀变窄,1例伴脊髓水肿,1例伴脊髓变性。CT显示病灶呈等密度,6例硬膜可见条片状钙化。MRI显示病灶于轴位图像上均呈半环形,包绕脊髓,T1WI上呈等（n=5）或低（n=3）信号,T2WI上呈等（n=3）或低信号（n=5）;增强后呈中等（n=2）或明显（n=6）强化,其中7例强化均匀,1例不均匀。结论 扁平形硬膜外脊膜瘤好发于颈椎管,可累及多个椎体节段,以硬膜增厚、钙化并硬膜外肿块形成为其特征。     

颅内肿瘤磁共振波谱谷氨酸/谷氨酰胺复合物定量研究

目的 评价氢质子磁共振频谱(¹H-MRS)定量检测谷氨酸复合物(Glx)浓度在颅内肿瘤定性诊断和分级诊断中的应用价值。 方法 采用GE 1.5T MRI系统,对38例颅内肿瘤患者(包括脑膜瘤、星形细胞瘤、脑转移瘤)及9名正常志愿者进行单体素¹H-MRS扫描,用LCModel软件定量Glx浓度。38例颅内肿瘤患者均经病理及临床证实。 结果 脑膜瘤Glx峰的出现率高于星形细胞瘤和脑转移瘤。脑膜瘤Glx浓度较正常脑组织、星形细胞瘤、脑转移瘤明显升高(P<0.05)。脑转移瘤与星形细胞瘤间Glx浓度的差异无统计学意义(P>0.05);脑转移瘤与高级星形细胞瘤间Glx浓度的差异也无统计学意义(P>0.05)。低级星形细胞瘤Glx浓度较高级星形细胞瘤高(P<0.05)。 结论 ¹H-MRS定量检测Glx浓度对脑膜瘤的定性诊断有重要的提示意义,对星形细胞瘤的分级诊断可能具有一定的意义,瘤体Glx定量无法鉴别脑原发肿瘤和脑转移瘤,瘤周水肿区Glx定量价值仍有待探索。     

黏液性脂肪肉瘤的CT、MRI表现

目的 探讨黏液性脂肪肉瘤的CT、MRI表现特征。 方法 回顾性分析经手术病理证实的24例黏液性脂肪肉瘤的CT、MRI表现特点。18例术前接受CT平扫,其中9例同时接受增强扫描;6例接受MR平扫,其中5例同时接受增强检查。 结果 24例黏液性脂肪肉瘤均表现为单发结节或肿块;发生于下肢(n=12)尤其大腿(n=9)最为多见,其次是腹膜后(n=7);发生于四肢的14例患者中,病变位于肌间隙10例(n=10),肌肉内2例(n=2),皮下脂肪层内2例(n=2);15例肿瘤形态规则,边界尚清,9例形态不规则,边界不光整,可见分叶等征象;病灶最大径2.0~38.0 cm,平均(12.5±8.0)cm。18例CT平扫CT值11.0~30.0 HU,平均(19.4±6.8)HU;6例MR平扫T1WI病变与肌肉相比以等或稍低信号为主,2例内见云絮状高信号;4例T2WI病变与皮下脂肪相比以明显高信号为主,内有稍高信号区和(或)线样低信号分隔,2例呈均匀显著高信号;14例CT和MR增强后病变均表现为明显不均匀强化;CT强化最显著区CT值35.0~112.0 HU,平均(62.7±27.0)HU。 结论 黏液性脂肪肉瘤的CT、MRI表现有一定特征,CT平扫多为囊样低密度影,MRI以T1WI低信号、T2WI显著高信号为主,T2WI可伴稍高信号区和(或)线样低信号分隔,增强后多呈显著不均匀强化。     

MRI诊断侧脑室神经上皮肿瘤

目的 分析侧脑室神经上皮肿瘤的MRI特征,提高对不同组织类型侧脑室神经上皮肿瘤的诊断水平.方法 回顾分析经手术病理证实的25例侧脑室神经上皮肿瘤的影像学资料,结合手术及病理结果进行分析.结果 侧脑室神经上皮肿瘤以星形细胞瘤(14例)为主,其次为室管膜瘤(4例).星形细胞瘤、室管膜瘤、室管膜下瘤、脉络丛乳头状瘤T1WI均呈稍低信号,中枢神经细胞瘤呈等信号,少突-星形细胞瘤、毛细胞星形细胞瘤呈等及稍低信号;星形细胞瘤、中枢神经细胞瘤、室管膜瘤、少突-星形细胞瘤、室管膜下瘤、脉络丛乳头状瘤T2WI均呈稍高信号,毛细胞星形细胞瘤呈稍高及高信号;增强扫描室管膜瘤、毛细胞星形细胞瘤及脉络丛乳头状瘤实性部分明显强化,星形细胞瘤中度至明显强化,少突-星形细胞瘤中度强化,中枢神经细胞瘤轻至中度强化,室管膜下瘤轻度强化.结论 不同组织类型侧脑室神经上皮肿瘤的MRI表现有一定的特征性,MRI在侧脑室神经上皮肿瘤的诊断和鉴别诊断方面有重要的意义.     

磁共振弥散加权成像诊断不同病理类型脑膜瘤

目的 探讨DWI及ADC值鉴别诊断良恶性脑膜瘤以及对脑膜瘤病理分型的价值。方法 回顾性分析经手术病理证实的109例脑膜瘤患者,于Functool图像后处理工作站上测量肿瘤实质区、瘤周水肿区及对侧正常脑白质ADC值,计算相对ADC值（rADC）;比较不同病理亚型及良恶性脑膜瘤的DWI信号特征及ADC值的差异。结果 良恶性脑膜瘤DWI信号差异无统计学意义（χ²=4.95,P=0.29）,不同病理亚型脑膜瘤DWI信号差异亦无统计学意义（χ²=17.86,P=0.12）。良恶性脑膜瘤肿瘤实质强化区rADC值（rADCt）差异有统计学意义（t=2.57,P=0.01）,而二者肿瘤实质强化区ADC值（ADCt）、瘤周水肿区ADC值（ADCe）及瘤周水肿区rADC值（rADCe）差异均无统计学意义（P均>0.05）。血管瘤型脑膜瘤ADCt及rADCt值高于其他各病理亚型（P均<0.05）;间变型脑膜瘤ADCt及rADCt低于纤维型及脑膜皮细胞型（P均<0.05）。结论 rADCt可用于鉴别良恶性脑膜瘤;ADCt及rADCt值对鉴别诊断脑膜瘤病理亚型具有一定的临床价值。     

原发性胆汁性肝硬化的MRI表现

目的 总结原发性胆汁性肝硬化(PBC)的MRI征象,探讨MRI对PBC的诊断价值及其对肝纤维化程度的评估价值。方法 回顾性分析临床确诊为PBC的45例患者(其中33例接受肝穿刺活检)的MRI征象,并与病理结果进行相关性分析。结果 45例PBC的MRI征象:弥漫性肝大17例(17/45,37.78%);门静脉周围T2WI高信号影35例(35/45,77.78%);T2WI肝脏信号不均匀34例(34/45,75.56%);门静脉周围晕征34例(34/45,75.56%);腹部淋巴结增大39例(39/45,86.67%)。接受肝穿刺活检的33例PBC中,肝脏信号不均匀性分级与组织学分期存在明显正相关(r=0.703,P<0.001);晕征在组织学各期出现频率差异有统计学意义(P=0.034),晕征分级与组织学分期呈正相关(r=0.687,P<0.001),其中Ⅰ期与Ⅱ期比较,晕征分级无统计学意义(P=0.841),Ⅱ期与Ⅲ期、Ⅲ期和Ⅳ期比较差异有统计学意义(P均<0.05);增大淋巴结在组织学各期出现频率、大小差异均无统计学意义(P均>0.05)。结论 MRI诊断PBC有重要价值,晕征及肝脏信号不均匀性有助于肝纤维化程度的评估。     

常规MRI在子宫肌瘤超声消融疗效评价及随访中的价值

目的 探讨常规MRI在评价超声消融治疗子宫肌瘤疗效及随访中的价值。方法 回顾性分析158例经超声消融治疗后6个月内接受MR检查的子宫肌瘤患者。所有患者均接受FS TSE T2W序列及增强前后T1W VIBE FS序列成像。分析超声消融后肌瘤的MR平扫图像信号改变,并与增强图像进行比较,观察信号变化规律,计算信号变化区域的体积及其相关性。结果 超声消融治疗后, VIBE FS T1WI上子宫肌瘤高信号区域与增强后所测坏死区域一致,二者间体积差异无统计学意义。单变量分析发现平扫VIBE FS T1WI上高信号区域的体积与增强图像上坏死区域的体积呈高度相关(r=0.99,P<0.001)。FS TSE T2WI可以确定子宫肌瘤的边界、大小。结论 常规MR平扫可准确评价超声消融治疗子宫肌瘤的疗效,T2WI可确定子宫肌瘤的边界、大小,T1WI可准确测量肌瘤坏死区域的体积。     

3.0TMR相位对比法测量正常人肺、体循环血流

目的 观察3.0T MR相位对比法成像(PC-MRI)在体测量血流的准确性。方法 采用PC-MRI对15名健康志愿者的肺动脉主干、左、右肺动脉、主动脉、上、下腔静脉进行血流测量,计算各血管一个心动周期的平均血流量(AF)和反流分数(RF)。采用配对样本t检验分析肺、体循环血流差异。结果 肺动脉主干与主动脉的AF和RF差异无统计学意义,右肺动脉AF显著大于左肺动脉(t=3.092,P=0.004),左肺动脉RF明显大于右肺动脉(t=－5.502,P=0.001)。上腔静脉AF明显低于下腔静脉(t=－6.866,P＜0.001),下腔静脉RF明显大于上腔静脉(t=4.250,P＜0.001)。肺动脉主干、主动脉及腔静脉AF比为1∶1.009∶0.974(r=0.939~0.991,P＜0.05)。结论 PC-MRI 能够准确测量肺、体循环大血管血流量。     

Guns and Knives in New Mexico: Patterns of Penetrating Trauma, 1978–1993

Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.     

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.     

Interprofessional approaches to creating safe,high quality health care

Three supplementary perspectives are presented arguing that interprofessional collaboration is both necessary and desirable. Nonetheless, there are often too many serious intra-professional barriers and obstacles to interprofessional collaboration to make it successful. Some of these barriers, it is argued and illustrated, are found in the multiple ways in which professional identity is tacitly acquired and embodied in the practitioners' habitual, everyday practice. The paper then explores ways in which reflection, especially Second order reflection, can help to elucidate and overcome these obstacles, as well as increasing professional adaptability and competence.     

Systematic Reviews Published in the January 2011 Issue of The Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly as a DVD and monthly online. The January 2011 issue (first quarterly DVD for 2011) contains 4515 complete reviews, 1985 protocols for reviews in production, and 13,521 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 641,000 randomized controlled trials, and 14,018 cited papers in the Cochrane methodology register. The health technology assessment database contains over 9300 citations. One hundred and seven new reviews have been published in the last 3 months, of which five have potential relevance for practitioners in pain and palliative medicine.     

Modified micro-superior percutaneously-assisted total hip: early experiences & case reports

Because of the extensile nature and familiarity of the standard posterior-lateral approach to the hip, a family of "micro-posterior" approaches has been developed. This family includes the Percutaneously-Assisted Total Hip (PATH) approach, the Supercapsular (SuperCap) approach and a newer hybrid approach, the Supercapsular Percutaneously-Assisted Total Hip (SuperPATH) approach. Such approaches should ideally provide a continuum for the surgeon: from a "micro" (external rotator sparing) posterior approach, to a "mini" (external rotator sacrificing) posterior approach, to a standard posterior approach. This could keep a surgeon within his comfort zone during the learning curve of the procedure, while leaving options for complicated reconstructions for the more practiced micro-posterior surgeons. This paper details one author's experiences utilizing this combined approach, as well as permutations of this entire micro-posterior family of approaches as applied to more complex hip reconstructions.     

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.     

Structure and function of "metalloantibiotics"

Although most antibiotics do not need metal ions for their biological activities, there are a number of antibiotics that require metal ions to function properly, such as bleomycin (BLM), streptonigrin (SN), and bacitracin. The coordinated metal ions in these antibiotics play an important role in maintaining proper structure and/or function of these antibiotics. Removal of the metal ions from these antibiotics can cause changes in structure and/or function of these antibiotics. Similar to the case of "metalloproteins," these antibiotics are dubbed "metalloantibiotics" which are the title subjects of this review. Metalloantibiotics can interact with several different kinds of biomolecules, including DNA, RNA, proteins, receptors, and lipids, rendering their unique and specific bioactivities. In addition to the microbial-originated metalloantibiotics, many metalloantibiotic derivatives and metal complexes of synthetic ligands also show antibacterial, antiviral, and anti-neoplastic activities which are also briefly discussed to provide a broad sense of the term "metalloantibiotics."