131I-RC-160对转染SSTR2基因的A549肺腺癌移植瘤的抗肿瘤效应

目的 研究131I-RC-160(伐普肽)对转染人生长抑素受体二型(SSTR2)的A549(A549-SSTR2)肺腺癌移植瘤的抑制作用.方法 建立A549-SSTR2肺腺癌裸鼠皮下移植瘤模型,同时建立pcDNA3质粒转染组的A549(A549-pc3)肺腺癌移植瘤模型作对照,观察131I-RC-160、RC-160、Na131I对移植瘤的抑制作用,等量的生理盐水作空白对照.治疗结束后,计算抑瘤率,随后处死裸鼠,取肿瘤组织作HE染色和免疫荧光染色,观察瘤组织的病理变化.采用SPSS 11.0软件对数据进行统计学处理.结果 A549-SSTR2细胞致瘤组中,131I-RC.160组和RC-160组的移植瘤生长明显受抑[抑瘤率分别为(75.1±4.2)%和(45.2±3.7)%],且131I-RC-160的抗肿瘤增殖效应较RC-160明显提高,差异有统计学意义(t=-6.165,P＜0.01);HE染色显示131I-RC-160组的肿瘤组织大部分片状坏死,残留少量瘤细胞,RC-160组肿瘤组织也可见片状坏死,但不如131I-RC-160组明显;免疫荧光染色显示131I-RC-160组和RC-160组的坏死区域荧光强度明显减弱,未坏死区域与生理盐水对照组无明显差异,可见明亮的绿色荧光.A549-pc3细胞致瘤组中,131I-RC-160和RC-160对瘤体有较弱的抑制效应[抑瘤率分别为(18.4 ±3.9)%和(15.2±3.4)%],与生理盐水组差异均无统计学意义(t值分别为-0.261和-0.302,P＞0.1);HE染色显示可见点状坏死,未见明显片状坏死;免疫荧光染色各组均未见明显的绿色荧光.Na131I组对转染或未转染SSTR2的移植瘤抑制作用与生理盐水组差异无统计学意义.结论 将SSTR2转染至不表达SSTR2的肿瘤后,可以介导放射性核素对肿瘤进行靶向杀伤效应,提高对这类肿瘤的治疗效果,为外源性受体基因介导放射性核素靶向性内照射治疗肿瘤提供依据.     

125I标记三链形成寡核苷酸对肝癌细胞生长的抑制作用

目的探讨^125I标记的三链形成寡核苷酸（TFO）对肝癌细胞的抑制作用，为HBV相关肝细胞癌（HCC）的基因治疗提供实验依据。方法合成能与HBV前S基因特异结合的TFO，并以^125 I标记（^125 I-TFO）；分^125I—TFO、等量TFO、相同活度^125 I和空白对照4组与HepG2．2．15细胞共同培养，通过ELISA法检测培养前后各组细胞上清中乙型肝炎e抗原（HBeAg）和乙型肝炎表面抗原（HBsAg）含量的变化，以四甲基偶氮唑蓝（M1Tr）比色法检测各组细胞存活率。结果^125 I-TFO标记率〉93％，稳定性较好，37℃放置12h放化纯90．8％，48h81．1％，72h73．2％；^125I-TFO组在转染48h对HepG2．2．15细胞合成HBeAg及HBsAg的抑制作用最强，对HBeAg和HBsAg表达的抑制率（74．5％和45．2％）及细胞杀伤率[72h细胞增殖抑制率为（31．64-2．5）％]高于其他实验组（P〈0．01）。结论^125 I-TFO可以抑制HBV抗原表达，杀伤肝癌细胞，为制备抗HBV、抗HCC的放射性基因治疗药物提供依据。     

131I-17-丙烯胺基-17-去甲氧基格尔德霉素对人乳腺癌细胞生长的抑制作用

目的 探讨^131I-17-丙烯胺基-17-去甲氧基格尔德霉素（17-AAG）对人乳腺癌细胞生长的影响及其相关机制。方法 采用过氧化氢标记法制备^131I-17-AAG。细胞杀伤实验分为5组：二甲基亚砜（DMSO）对照（A）组，Na^131I370kBq（B）组，17-AAG2．5mg／L（C）组，^131I-17-AAG370kBq（D）组，^131I-17-AAG370kBq＋17-AAG2．5mg／L（E）组。用四甲基偶氮唑蓝（MTT）法检测各种药物对人乳腺癌细胞MCF-7的生长抑制作用，流式细胞术分析细胞凋亡及细胞周期变化，RT—PCR检测药物处理前后MCF-7细胞中Akt2基因的mRNA表达情况。结果 ^131I-17-AAG的标记率为83％，放化纯为96．6％，比活度为1．48×10^5MBq／μmol。各组药物对细胞的杀伤呈时间效应，随着时间的延长，细胞的抑制率都呈明显上升趋势，尤以E组趋势明显。A～E组药物作用48h后，通过亚G1峰检测MCF-7细胞凋亡率分别为（1．54±0．13）％，（5．72±1．05）％，（12．97±1．44）％，（20．65±1．36）％，（35．39±4．15）％，各组细胞凋亡率差异有统计学意义（P均〈0．05）。C组，D组及E组Akt2基因的mRNA表达均比A组降低，其中E组降低尤为明显。结论 ^131I-17AAG能够抑制MCF-7细胞的生长并促进其凋亡，且能有效抑制Akt2基因的mRNA表达，和17-AAG联合应用能够增强肿瘤细胞对放疗的敏感性。     

32P与顺铂联合应用对肺癌细胞凋亡的影响

目的观察^32P照射对肺腺癌细胞株A549细胞凋亡的影响及其机理。方法用^32P溶液对A549细胞进行内照射，用顺铂进行化疗。通过四唑盐(MTT)比色法计数、流式细胞术、透射电镜及免疫组织化学检测等方法，观察A549细胞的细胞存活率、细胞凋亡率、细胞超微结构改变及相关基因表达。结果随^32P放射性浓度和顺铂剂量增加，A549细胞存活率明显下降，且两者间存在协同作用；联合应用低剂量顺铂(2．5μg/ml)和低放射性浓度(555kSq／ml)^32P时，A549细胞存活率明显下降。细胞凋亡率上升，细胞超微结构改变，且在诱导细胞凋亡过程中，P53、bax基因表达上调，bcl-2／bax比值下调。结论低放射性浓度^32P溶液与顺铂联合应用，既能有效促进A549细胞凋亡，又能明显降低两者剂量．减少毒副作用．     

125I-血管抑素内化及杀伤ECV304细胞的研究

目的 探讨人脐静脉内皮细胞系ECV304细胞内化血管抑素(As)的能力及125I-AS杀伤ECV304细胞的效应.方法 采用放射配基结合分析法,37~C条件下AS受体阳性细胞ECV304与125I-AS共同保温0.25,0.5,1,4,8,16,20和24 h后,分别检测细胞的内化率;采用四甲基偶氮唑蓝(MTT)法测不同剂量125I-AS、Na125I及AS对ECV304细胞作用24,48,72,96 h的杀伤作用.采用SPSS 11.0软件对数据进行统计分析.结果 37℃条件下保温,125I-AS迅速与AS受体结合并使受体发生内化.0.5 h内,ECV304细胞受体内化率、膜结合率及细胞结合率均随时间的延长而增加.0.5 h时受体内化率为(12.6±1.1)%,膜结合率为(19.1±2.2)%,细胞结合率为(31.7±1.6)%,受体内化率与膜结合率呈正相关(r=0.814,P<0.05).0.5 h后ECV304细胞受体内化率随时间延长继续增加,膜结合率随时间延长逐渐减少;至24 h时受体内化率达(28.0±3.0)%,膜结合率为(10.8±1.4)%,细胞结合率为(38.8±2.3)%,受体内化率与膜结合率呈负相关(r=-0.681,P<0.05).125I-As对ECV304细胞杀伤作用呈剂量.效应、时间.效应关系,以370 kBq/ml 125I-AS作用96 h的杀伤作用最大,细胞抑制率达(79.4±3.7)%,明显强于Na125I或AS(F=312.9013,P<0.01).结论 125I-AS可在AS受体介导下内化进入并杀伤ECV304细胞,呈剂量一效应、时间一效应关系.     

125I-抑制素在大鼠垂体和下丘脑的放射自显影研究

目的研究抑制素（INH）在体条件下能否通过大鼠的血脑屏障及在垂体或下丘脑的分布。方法采用颈静脉灌流和放射自显影技术，将20只SD大鼠分为4组，每组5只，第1～3组（实验组）颈静脉注射^125 I-INH50μl，第4（对照）组注射等量的生理盐水。第1，2，3组分别于注射后30，60和120min断头处死，取出垂体、下丘脑，以生理盐水洗涤，测量放射性计数，取放射性最大组的垂体与下丘脑组织行放射自显影分析。结果第1组垂体的放射性最高[（1008．00±5．78）Bq]，而第2和3组分别为（723．00±4．95）和（491．00±4．90）Bq；1～3组的下丘脑放射性分别为（20．00±1．01），（22．00±0．95）与（19．00±0．73）Bq。第4组垂体与下丘脑的放射性分别为（16．00±1．40），（15．00±0．98）Bq。各实验组大鼠垂体的放射性与对照组差异有统计学意义（P〈0．01），且在注射后30min放射性最大（第1组），60和120min后逐渐降低；而实验组与对照组大鼠的下丘脑放射性差异无统计学意义（P〉0．05）；放射自显影结果示，实验组大鼠的垂体组织上有明显的银颗粒，而对照组没有；实验组和对照组大鼠的下丘脑组织上均未见明显的银颗粒。结论^125I-INH能通过大鼠血脑屏障，垂体在注射后30min放射性最大，在大鼠垂体上有INH结合位点或受体，而在其下丘脑没有。     

抗ProGRP（31-98）单克隆抗体E-B5的^131I标记及体内生物分布研究

目的研究抗胃泌素释放肽前体（ProGRP）片段ProGRP（31-98）单克隆抗体E—B5的^131I标记方法以及标记抗体在正常小鼠体内的生物分布特点。方法利用流式细胞仪检测人小细胞肺癌NCI—H446细胞株和肺腺癌A549细胞株（对照）ProGRP表达,对人小细胞肺癌组织切片进行免疫组织化学染色分析。采用氯胺T法进行^131I-E—B5标记,利用纸层析法测定其标记率、放化纯和稳定性,细胞结合分析法测定标记抗体的免疫活性。将^131I—E—B5注入正常昆明小鼠体内,对药物体内分布及药物代谢动力学进行研究。对荷小细胞肺癌裸鼠模型进行^131I—E—B5放射免疫显像,观察移植瘤的显影情况。采用SPSS13．0软件处理数据。结果流式细胞仪测得处于对数生长期的NCI—H446、A549细胞ProGRP表达率分别为89％和12％,人小细胞肺癌组织切片免疫组织化学染色见明显的E—B5阳性细胞分布,并显示ProGRP表达在肿瘤细胞的细胞质内。^131I—E—B5标记率为90．8％,放化纯为99．28％,在37℃水浴箱中放置24h后放化纯仍〉70％,和健康人血清充分混合后放置24h放化纯为68．1％,对NCI-H446和A549的免疫结合率分别为71．6％和33．2％。^131I—E—B5在小鼠体内过程符合一级血药动力学二室模型,t1/2α=0．2h,t1／2β=8．35h,在体内主要通过肝和肾代谢。注射^131I—E—B5后72和96h小细胞肺癌裸鼠移植瘤体显影最清晰。结论NCI—H446细胞株及人小细胞肺癌组织高表达ProGRP,E-B5对小细胞肺癌有较好的靶向作用。^131I—E—B5标记率及放化纯高,在体内外有很好的稳定性,标记后的E—B5仍然保持着良好的免疫活性,对小细胞肺癌放免显像和治疗有潜在的应用前景。     

11C-PD153035摄取与肿瘤EGFR表达水平相关性的研究

目的研究^11C4-（3-溴苯氨基）-6，7-双甲氧喹唑啉（PD153035）摄取与表皮生长因子受体（EGFR）表达水平之间的关系。方法在体外测定人乳腺癌细胞MDA—MB-468、MDA—MB-231和人肺腺癌细胞A549的EGFR表达水平以及对^11C—PD153035的摄取。分别建立裸鼠种植瘤模型，通过尾静脉注射^11C—PD153035后即刻行PET显像，用感兴趣区（ROI）法在注射后即刻及10，20，30，40，50和60min测定病灶／健侧前肢正常组织放射性计数（T／NT）比值。显像结束后立即处死动物，切除肿瘤，测量肿瘤内摄取的放射性。结果在体外肿瘤细胞对^11C—PD153035的摄取与肿瘤细胞EGFR表达水平明显相关（r^2=0．78，P=0．001）。在动物体内，TINT与肿瘤细胞的EGFR表达水平明显相关（r^2=0．65，P=0．004）。离体肿瘤组织对^11C—PD153035的摄取与肿瘤细胞的EGFR表达水平明显相关（r^2=0．64，P=0．005）。结论^11C-PD153035的摄取与肿瘤细胞的EGFR表达水平明显相关，EGFR的^11C—PD153035 PET显像有可能为肿瘤的诊断与治疗提供依据。     

分化型甲状腺癌患者^131I治疗后体内残留放射性活度的评估

目的 评估分化型甲状腺癌（DTC）患者^131I治疗后体内残留放射性活度.方法 本研究共纳入了35例DTC患者,分为“清甲”（20例）与“清灶”（15例）组,分别于服^13I后2、6、24、48、72 h进行^131I全身显像及1m处当量剂量率的测定,以2h时显像计数和活度作为总计数和总活度.根据各时间点显像计数与2h的显像计数比值间接估算体内残留放射性活度,并估算患者体内残留放射性活度达到400 MBq时的1m处当量剂量率.统计学分析采用直线相关与回归分析.结果 “清甲”组服^131I后2、6、24、48、72 h体内残留^131I活度占服^131I总活度的百分比分别为99％±4％、86％±6％、35％±10％、12％±8％、7％±8％, “清灶”组分别为99％±1％、91％±7％、47％±17％、11％±9％、4％±6％. “清甲”组服^131I后2、6、24、48、72 h的1m处当量剂量率分别为（157±37）、（120±36）、（35±13）、（11±9）、（9±11）μSv/h,“清灶”组分别为（234±43）、（186±51）、（49±20）、（12±11）、（4±6）μSv/h.体内残留的放射性活度与1m处当量剂量率呈正相关（r=0.87,P＜0.001）.“清甲”与“清灶”组服^131I后48、72 h体内残留放射性活度分别为（432±292）、（265±281） MBq及（731±701）、（277±470） MBq,对应的1m处当量剂量率为8～ 11 μSv/h.结论 DTC患者服^131I后48～72 h体内残留放射性活度达到国家标准规定的400 MBq时,即DTC患者1m处当量剂量率达到8～11 μSv/h时方可出院.     

BMSC对内毒素诱导的肺泡上皮细胞氧化应激的影响

目的 探讨骨髓间充质干细胞（(bone marrow stromal cell,BMSCs）对内毒素（lipopolysaccharide, LPS）诱导的Ⅱ型肺泡上皮细胞（alveolar epithelial cellⅡ,AECⅡ）氧化应激的影响。方法 选用A549细胞代替AECⅡ,将实验分为A549组、A549+LPS组、A549-BMSC+LPS组及A549-BMSC+PBS组,即单独培养A549细胞或将BMSC与A549细胞共培养于Transwell体系,培养过夜后予LPS或等体积的PBS刺激。收集各组A549细胞样本,通过流式细胞仪检测活性氧（reactive oxygen species,ROS）的表达水平,并利用化学检测试剂盒,通过分光光度计检测脂过氧化物（lipid peroxides,LPO）、丙二醛（malondialdehyde,MDA）、超氧化物歧化酶（superoxide dismutase, SOD）及谷胱甘肽过氧化物酶（glutathione peroxidase,GSH）表达水平。结果 A549细胞在LPS的干预下,细胞内ROS表达水平（658.40±27.89）及其代谢产物LPO（1.46±0.15）、MDA（36.85±2.75）的水平明显升高（P<0.001）,抗氧化因子SOD（13.44±3.32）、GSH（346.56±44.33）的活性明显降低（P<0.001）;与A549+LPS组比较,A549-BMSC+LPS组ROS（544.61±41.30）、LPO（1.05±0.09）、MDA（10.63±0.95）的水平明显降低（P=0.001、P=0.006、P<0.001）,SOD（33.41±3.59）、GSH（447.18±45.56）的活性明显升高（P=0.001、P=0.028）;而与A549组比较,A549-BMSC+PBS组ROS（108.97±17.49）、LPO（0.12±0.03）、MDA（1.23±0.36）的表达水平呈下降趋势（P=0.033、P=0.004、P=0.012）,SOD（68.33±8.01）、GSH（793.89±62.33）的活性进一步升高（P=0.001、P=0.002）。结论 BMSC能显著减轻LPS诱导的AECⅡ细胞的ROS生成,同时能正向调节其抗氧化的能力,可以一定程度上抑制LPS诱导的AECⅡ细胞的氧化应激反应。抑制肺泡上皮细胞氧化应激状态下ROS的产生、增强肺泡上皮细胞抗氧化的能力,或许可以成为治疗急性肺损伤/急性呼吸窘迫综合征的新策略之一。     

Stress MR imaging for evaluation of popliteal artery entrapment

The popliteal artery entrapment (PAE) syndrome has been recognized as a cause of arterial occlusion in young people. It is the result of an anomaly of the relationship between the popliteal artery and the gastrocnemius muscle. Eight young healthy volunteers (16 legs) and six patients (10 legs) with suspected PAE underwent magnetic resonance (MR) imaging. Gradient-echo images were obtained in axial planes with the leg at rest and during active plantar flexion against resistance. Imaging at rest allowed identification of PAE signs in only one leg, which had an anomalous medial course of the popliteal artery. In the other cases, only the stress technique was able to show signal loss in the popliteal artery due to muscular compression (two legs) or the presence of accessory muscle slip around the vessel (two legs), as confirmed at surgery. MR imaging is therefore a useful technique for the diagnosis of PAE because of its capability of combining information obtainable with other modalities.     

MR imaging of muscle and tender points in fibromyalgia

Fibromyalgia is a syndrome manifested by chronic, diffuse muscu-loskeletal aching and soreness, palpable muscle tender points, and other symptoms. Standardized clinical diagnostic criteria have recently been developed. Skeletal muscle has been postulated as the end organ in this disease. Biochemical, histologic, electromyographic, and conventional radiographic studies have demonstrated no definitive abnormality. This study sought to establish whether magnetic resonance (MR) imaging could demonstrate any abnormality in these patients. Eighteen patients were entered in the study, 14 of whom were able to complete their examinations. T1 -weighted, T2-weighted, gradient-echo, and STIR (short-tau inversion-recovery) sequences were performed in all patients, with selected patients examined with T1weighted, gadopentetate dimeglu-mine-enhanced sequences. The trapezius and suboccipital regions were imaged in patients who, clinically, had active fibro-myalgia. No abnormalities could be detected. The authors conclude that the conventional MR imaging used in this study was unable to depict any primary skeletal muscle abnormality in fibromyalgia.     

Controversies in cervical spine imaging in trauma patients

No area of emergency radiology has generated as much discussion in recent years as the subject of cervical spine imaging for trauma patients. This review will be in three parts. The first will examine the indications for cervical imaging and will focus on those factors that make patients at high risk or low risk for cervical injury. The second part will discuss the merits of radiography and computed tomography as the main screening diagnostic examination. In addition to the roles of each modality in the evaluation process, such factors as efficacy of diagnosis, time (duration) of study, and cost will be discussed. Finally, the third part will explore the methods currently employed to clear the cervical spine in comatose patients.Presented at the Annual Meeting of the American Society of Emergency Radiology, Las Vegas, Nevada, 22–25 October, 2003     

Uterine contractions: Possible diagnostic pitfall at MR imaging

A total of 206 nongravid patients with various gynecologic problems underwent pelvic magnetic resonance (MR) examinations that included both sagittal T2-weighted and contrast agent–enhanced T1-weighted images. MR images were retrospectively reviewed to identify changes in endometrial configuration on serial images obtained during the same MR examination. In 20 MR examinations (all in women of reproductive age), endometrial distortion due to myometrial bulging was noted on T2-weighted or contrast-enhanced T1-weighted images. It was absent on other MR images obtained at different times. Myometrial bulging exhibited low signal intensity in 18 examinations. The finding resembled adenomyosis or leiomyoma on T2-weighted or contrast-enhanced T1-weighted images. These results evidence the presence of transient myometrial bulging and transient low-intensity myometrium in the nongravid uterus. This phenomenon is thought to represent uterine contraction. Clinicians should be aware of the potential presence of transient low-signal-intensity myometrial bulging that could present diagnostic problems in the normal uterus.     

Brodie Abscess: MR imaging appearance in 10 patients

The magnetic resonance (MR) imaging features of Brodie abscess have not yet been fully evaluated. Ten patients with Brodie abscess, eight of long bone and two of vertebra, were studied with MR imaging. Long bone abscess had a characteristic “target” appearance with four layers: (a) a center with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR (short-inversion-time inversion recovery) images, (b) an inner ring isointense to muscle on T1-weighted images and with high signal intensity on T2-weighted and STIR images, (c) an outer ring hypoin-tense on all images, and (d) a peripheral halo hypointense on T1-weighted images. In six of eight cases, a soft-tissue mass was found. The two vertebral abscesses had a less specific appearance, with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR images. Only the peripheral halo was clearly identified in both cases.     

Adrenal tissue characterization with 0.5-T MR imaging: Value of T2*-weighted images

The authors investigated the value of magnetic resonance (MR) imaging at 0.5 T for distinguishing adrenal adenomas from adrenal metastases. The series included 23 adrenal adenomas (18 nonhyperfunctioning, five hyperfunctioning) and 23 adrenal metastases from various organs. Adrenal tumor–liver signal intensity ratios on T1-, T2-, and T2*-weighted images were calculated for adrenal tissue characterization. Adrenal adenomas were more precisely distinguished from adrenal metastases on T2*-weighted images (21 of 23, 91%) than on T2-weighted images (15 of 23, 65%). T1-weighted images were not useful for this distinction. In conclusion, T2*-weighted images were better than routine T2-weighted images for distinguishing adrenal adenomas from adrenal metastases. It can be postulated that the total signal intensity of adrenal adenomas, which contain some fat components, decreased on T2*-weighted images because of an out-of-phase effect.     

Dynamic contrast-enhanced MR imaging assessment of vascularized free fibular grafts

Magnetic resonance (MR) imaging may be a noninvasive method for assessing perfusion of vascularized bone grafts placed for treatment of avascular necrosis. One proximal femur of seven beagles was devascularized, with insertion of a vascularized fibular graft. MR imaging at 1 week (seven dogs) and 6 weeks (five dogs) after surgery included pre- and postcontrast spin-echo sequences, unenhanced twodimensional time-of-flight (TOF) vascular imaging, and dynamic gradient-echo imaging during infusion of gadolinium. Relative signal intensity values of selected regions obtained from the dynamic gradientecho images were plotted as percent enhancement versus time. In the operated hip, MR imaging did not show enhancement in six of seven femoral heads and greater trochanters at 1 week after surgery, with similar results after 6 weeks. MR imaging of fibular grafts 6 weeks after surgery showed an initial rapid increase in enhancement and a subsequent slower increase in five of five dogs, although no enhancement was seen in six of seven dogs at 1 week. These findings contrasted with a rapid initial increase in enhancement followed by slow decline in non-operated hips. Two-dimensional TOP imaging did not show the vascular pedicle of the graft in any dog. Findings of radionuclide bone scanning performed 1 week after surgery were consistent with devascularization of the operated femur and fibular graft. However, tetracycline distribution and histologic findings confirmed the viability of five of five grafts within the devascularized femurs 6 weeks after surgery. Thus, dynamic contrast-enhanced MR imaging at 6 weeks after surgery is valuable for assessing vascular bone graft perfusion, while similar imaging at 1 week may suggest otherwise.     

Pericerebellar fluid collections in infancy,sequelae of birth injury? A retrospective CT study

Summary Retrospective analysis of axial CT scans from 600 consecutive pediatric patients revealed 37 patients (6%) with abnormal low density pericerebellar spaces. Fourteen of these 37 patients (38%) were diagnosed as cerebellar atrophy, whereas 23 of the 37 patients (62%) were diagnosed as mass-like pericerebellar fluid collections. Detailed analysis of the morphology of these spaces suggests that the CT criteria proposed in this paper distinguish between (a) those low attenuation pericerebellar spaces that represent cisternal dilatation caused by cerebellar atrophy (Group I — Atrophy) and (b) those low attenuation pericerebellar spaces that represent low density mass-like collections of fluid which distort a relatively normal cerebellum (Group II — Collections). Analysis of the medical records of the patients in Group II — Collections reveal a high incidence of prematurity, developmental delay, difficult birth and head trauma, possibly indicating that such collections represent sequelae of birth.     

Localized proton MR spectroscopy of the brain in children

Small-voxel (3.0–8.0 cm³), magnetic resonance (MR) imaging–guided proton MR spectroscopy was performed in 54 patients (aged 6 days to 19 years) with intracranial masses (n = 16), neurodegenerative disorders (n = 34), and other neurologic diseases (n = 4) and in 23 age-matched control subjects without brain disease. A combined short TE (18 msec) stimulatedecho acquisition mode (STEAM) and long TE (135 and/or 270 msec) spin-echo point-resolved spatially localized spectroscopy (PRESS) protocol, using designed radio-frequency pulses, was performed at 1.5 T. STEAM spectra revealed short T2 and/or strongly coupled metabolites; prominent resonances were obtained from N-acetyl aspartate (NAA), choline-containing compounds (Cho), and total creatine (tCr). Lactate was well resolved with the long TE PRESS sequence. Intracranial tumors were readily differentiated from cerebrospinal fluid (CSF) collections. All tumors showed low NAA, high Cho, and reduced tCr levels. Neurodegenerative disorders showed low or absent NAA levels and enhanced mobile lipid, glutamate and glutamine, and inositol levels, consistent with neuronal loss, gliosis, demyelination, and amino acid neuro-toxicity. Preliminary experience indicates that proton MR spectroscopy can contribute in the evaluation of central nervous system abnormalities of infants and children.