实验性大鼠脑血肿周围脑组织血流变化的CT灌注成像研究

目的 探讨建立大鼠脑血肿周围脑组织血流变化的CT灌注成像方法，并对其可行性进行研究。方法 雄性大鼠70只，采用随机数字抽样法将其分为注血组和对照组。分别将40μl新鲜自体血或生理盐水通过微量注射泵注入大鼠右侧尾状核制备脑出血模型。利用CT灌注成像对各组动物模型血肿周围脑组织血流变化进行观察，并与HE染色和红四氮唑(TTC)染色标本对照。通过计算机辅助CT脑灌注成像软件制作灌注CT参数图，并对血肿周围脑组织局部脑血流量(regional cerebral blood flow，rCBF)、局部脑血容量(regional cerebral blood volume，rCBV)和平均通过时间(mean transit time，MTT)进行相对值(病侧／健侧)测量。结果 注血组血肿周围脑组织存在不同程度低灌注梯度，血肿周围脑组织局部脑血流量(rCBF)呈波动性改变，在注血后1h rCBF降至最低，随后逐渐回升、下降，分别于注血后6h和24h2次回升至峰值。TTC染色血肿呈黑褐色，血肿周围未见白色梗死区。病理学检查显示在出血灶与正常脑组织间存在过渡带即血肿周围区，周围区内组织疏松，细胞不同程度水肿，星形细胞肿胀，神经细胞变性，出血灶周边可见毛细血管增生及炎细胞浸润。对照组CT灌注成像、TTC染色和病理学检查均未见明显异常。结论 大鼠脑血肿周围脑组织血流变化的CT灌注成像方法稳定可靠，能准确反映脑出血周围脑组织异常的血液动力学变化，是活体研究脑出血周围脑组织损伤较为理想的实验方法。     

实验性脑出血周围组织脑血流变化与脑水肿形成的相关研究

目的 探讨血肿周围组织脑水肿形成机制及其与局部脑血流变化间的关系，为脑出血临床救治提供实验基础。方法 雄性大鼠70只，随机数字抽样法分为注血组和对照组，分别将40山新鲜自体血或生理盐水通过微量注射泵注入大鼠脑右侧尾状核制备脑出血模型，利用CT灌注成像对大鼠脑出血模型进行动态增强扫描，通过计算机辅助脑灌注成像软件制作大鼠脑CT灌注参数图，对血肿周围局部脑血流量（regional cerebral blood flow，rCBF）、局部脑血容量（regional cerebral blood volume，rCBV）和对比剂平均通过时间（mean transit time，MTT）脑灌注参数进行相对值（病侧／健侧）测量，并与血肿周围脑组织水含量进行相关性分析。结果 大鼠脑注血后血肿周围组织存在低灌注梯度，血肿周围rCBF呈波动性改变，注血后1h rCBF降至最低，以后逐渐回升，分别于注血后6h和24h2次回升至峰值，并随后再度下降；血肿周围rCBV在注血后1h降至最低，随后逐渐增加，并于注血后24h增加至峰值；血肿周围脑组织水含量在注血后24h最高，并延续至72h；血肿周围脑组织水含量与血肿边缘区rCBV具有明显相关性，r=0．372（单侧），P〈0．05。结论 血肿周围组织脑水肿的形成是血脑屏障破坏、细胞毒性水肿及渗透性活性物质共同作用的结果，脑出血早期rCBF下降以及rCBV代偿性增加在脑出血血管源性脑水肿形成中发挥着重要作用，CT灌注成像是活体下研究血肿周围脑血流变化与脑水肿形成机制较为理想的方法。     

脑出血亚急性及慢性期血肿周围组织低灌注损伤的CT灌注成像研究

目的 探讨脑出血亚急性及慢性期血肿周围组织脑血液动力学变化及其相关影响因素。方法 对12例基底节区脑出血患者做了CT常规及灌注成像检查，对其中11例患者血肿体积及血肿周围局部脑血流量（regional cerebral blood flow，rCBF）、局部脑血容量（regional cerebral blood volume，rCBV）、对比剂平均通过时间（mean transit time，MTT）和最大峰值时间（time-to-peak，TTP）的比值（病侧／健侧）进行测量。结果 11例脑出血患者血肿体积最大为72．21ml，最小为13．68ml，血肿平均体积为26．83ml。rCBF参数图显示血肿周围低灌注梯度11例，表现为血肿周围rCBF减低区；rCBV参数图显示血肿周围低灌注梯度10例，表现为血肿周围rCBV减低区；血肿周围高灌注1例，表现为血肿周围rCBV增高区；同侧半球低灌注2例，表现为血肿侧脑组织rCBF、rCBV大面积减低区；时间参数图显示血肿周围TTP延长11例，MTT延长10例；血肿边缘区rCBF显著低于外层区rCBF；边缘区MTT、TTP明显长于外层区MTT、TTP；血肿外层区rCBF、rCBV与血肿边缘区rCBF、rCBV呈线性依从性改变。血肿周围（边缘区和外层区）rCBV与血肿体积有明显的相关性，r边缘区=0．764，r外层区=0．703（双侧），P值均〈0．05。血肿周围rCBF、rCBV、MTT和TTP与症状出现至行CT灌注扫描间期无明显相关性。结论 脑出血亚急性和慢性期，血肿周围脑组织依然存在低灌注梯度，低灌注区脑血流变化与血肿体积密切相关。CT灌注成像可清晰地显示出血肿周围异常的脑血液动力学变化，可为脑出血个体化救治及预后评估提供有价值的信息。     

CT灌注成像对脑膜瘤血流灌注的定量研究

目的　探讨CT灌注成像对脑膜瘤定量诊断的价值。方法　应用SomatomPlus 4螺旋CT扫描机 ,对 13例手术病理证实的脑膜瘤患者 (其中脑膜瘤复发 2例 )进行CT灌注成像扫描。经灌注软件处理 ,使用 2 5 6彩色直观地显示脑组织中血流灌注图 ,并计算出局部脑血流量 (rCBF)、局部脑血容量 (rCBV)、对比剂平均通过时间 (MTT) ,并与对侧脑组织灌注参数和肿瘤病理类型进行统计分析比较。结果　脑膜瘤的rCBV、rCBF值明显高于对侧脑组织 [rCBV分别为 (16 12 5± 12 135 )ml/ 10 0g与 (2 15 8± 1 345 )ml/ 10 0g ;rCBF分别为 (89 6 2 7± 6 3 193)ml-1·10 0g-1·min-1与 (2 5 5 99± 9 2 6 6 )ml-1·10 0g-1·min-1,P值均 <0 0 0 2 ]。脑膜瘤的MTT值也明显高于对侧脑组织 [分别为 (9 2 0 3±4 4 34)s与 (3 85 7± 2 2 90 )s,P值均 <0 0 0 1]。 7例不典型脑膜瘤的rCBV、rCBF和MTT值明显高于 4例典型脑膜瘤 [rCBV值分别为 (2 0 94 8± 9 4 2 4 )ml/ 10 0g与 (4 0 15± 2 4 5 4 )ml/ 10 0g ,P <0 0 1;rCBF值分别为 (115 76 6± 6 8 0 92 )ml-1·10 0g-1·min-1与 (32 113± 4 90 4 )ml-1·10 0g-1·min-1,P <0 0 5 ;MTT值分别为 (10 35 2± 3 74 4 )s与 (4 6 85± 0 912 )s,P <0 0 1]。 2例复发脑膜瘤     

实验性脑血肿周围组织脑血流变化的CT灌注成像与病理学研究

目的探讨血肿周围组织病理发展进程及其与血肿周围局部脑血流变化的关系。方法采用自体血注射法制备大鼠脑出血模型,对70只大鼠于术后1h、3h、6h、12h、24h、48h和72h7个时间点,利用GELightspeed螺旋CT扫描机灌注成像及计算机辅助系统制作大鼠脑CT灌注参数图,对血肿周围局部脑血流量(rCBF)、局部脑血容量(rCBV)和对比剂平均通过时间(MTT)脑血液动力学参数进行定量测量,并与大鼠脑TTC染色、HE-染色以及超微结构改变进行比较。结果大鼠脑血肿周围可见明显的低灌注梯度,血肿周围rCBF和rCBV显著降低,MTT延长。TTC染色血肿周围未见白色梗死区。HE-染色可见血肿周围区星形细胞肿胀,神经细胞变性、坏死,出血灶周边毛细血管增生伴炎细胞浸润。电镜观察显示,注血早期血肿周围组织星形细胞肿胀,神经细胞改变不明显,髓鞘板层松散;随着注血后时间延长,血肿周围组织损伤呈渐进性加重,星形细胞肿胀明显,神经细胞出现变性,髓鞘板层发生局部断裂、崩解。结论大鼠脑注血早期血肿周围局部脑血流的显著降低引发了血肿周围及远隔区脑组织的缺血性损伤,注血后急性期血肿周围组织细胞损伤呈进行性加重,血肿周围存在涉及多种细胞损伤机制的半暗带。     

帕金森病动物模型的99Tcm-TRODAT-1显像研究

目的　研究帕金森病 (PD)模型猴99Tcm 2 β [N ,N’ 双 (2 巯乙基 )乙撑二胺基 ]甲基 ,3β (4 氯苯基 )托烷 (TRODAT 1)显像与局部脑血流量 (rCBF)及结构改变间的关系 ,探讨99Tcm TRODAT 1显像早期诊断PD的价值。方法　对 5只猴在制成单侧PD模型前后分别进行99Tcm TRODAT 1和rCBF显像 ,并对 2只PD模型猴进行MRI。结果　99Tcm TRODAT 1显像示 ,正常猴 3h纹状体 小脑的放射性比值为 1.48,PD模型猴健侧纹状体 小脑放射性比值为 1 42 ,损毁侧为 0 .96。PD模型猴双侧纹状体血流灌注与正常猴比较无差别 ,MRI未发现形态及结构改变。结论　99Tcm TRODAT 1能特异性地与多巴胺转运体 (DAT)结合 ,可望用于PD的早期诊断     

精神分裂症SPECT脑显像的影像特征及其应用价值

目的:探讨精神分裂症(SC)患者99mTcECDSPECT脑血流灌注显像的影像特征及临床应用价值。材料和方法:对10例正常对照组和24例SC组进行SPECT局部脑血流灌注(rCBF)断层显像。结果:10例正常对照组rCBF均未见异常。SC组rCBF异常者10例,阳性率为41.7%(10/24)。异常主要表现为脑灰质小范围的局限性放射性分布轻度减低,累及16处脑叶,包括颞叶、额叶、顶叶、基底节、枕叶和小脑。结论:SC患者rCBF可出现异常,SPECT对该病的诊断及脑功能异常的定位研究均有重要价值。     

神经节苷脂GM1对大鼠脑损伤后局部血流量的调节作用

目的：探讨GM1对脑损伤后局部血流量（rCBF)的调节作用及对脑水肿的治疗作用。方法：采用大鼠左顶部中型液压脑损伤,模型用干湿比重法和氢清除法检测同侧皮质正常及伤后不同时相点的脑组织含水量和rCBF。结果：（1）脑组织含水量：损伤组伤后0．5小时即上升，48小时达到高峰，明显高于假伤对照组。GM1组伤后水含量对照组比较无显著性差异，但明显低于损伤组，两者间有显著性差异。（2）rCBF：损伤组伤后急剧下降，1小时达最低点，其后缓慢回升，24小时恢复到假伤对照组比较水平，48例时则明显高于假伤对照组，表现为伤后早期的低灌注和后期的过度灌。GM1组无上述变化，与假伤对照组比较无显著性差异。结论：GM1可通过改善伤后rCBF而减轻创伤性脑水肿。     

CT灌注观察脑出血后血肿周围组织血流灌注变化

目的:探讨脑出血患者血肿周围组织血流的动态变化规律。方法:脑出血患者59例,分别在入组时、入组后7d、14d、28d应用CT灌注测量血肿周围组织的局部脑血流量(rCBF)、局部脑血容量(rCBV)、对比剂平均通过时间(MTT)、对比剂峰值时间(TTP)参数数值,计算脑岀血侧(患侧)与其健侧镜像部位各参数的比值,并进行对比分析。结果:脑出血后rCBF、rCBV 7d时最低,随后逐渐升高,其患侧与健侧比值各时相点均<1。MTT与TTP 7d时达高峰,随后逐渐缩短,其患侧与健侧比值各时相点均>1。结论:脑出血后血肿周围组织存在持续的低灌注状态,且这种低灌注状态随时间改变呈波动性的变化规律。     

无症状脑梗死患者的乙酰唑胺脑负荷显像

目的探讨乙酰唑胺介入一日法脑负荷显像在无症状脑梗死(SCI)中的应用价值.方法对照组7例,无症状脑梗死(SCI)患者18例,进行一日法乙酰唑胺负荷和静息99Tcm-双半胱乙酯脑血流显像.所有受检者均有CT或MRI结果.对负荷和静息显像进行半定量分析,在大脑皮质设置350个方型感兴趣区(ROI),结合负荷和静息显像分4种类型A型静息与负荷显像局部脑血流量(rCBF)都正常;B型静息时rCBF正常,负荷时出现血流灌注减低;C1型静息时rCBF减低,负荷后无改变;C2型静息时即出现rCBF减少,负荷后rCBF降低更明显;D型静息时rCBF减低,负荷后rCBF有改善.结果对照组98个ROI中,A型96个,B型2个;SCI组252个ROI中,A型198个,B型9个,C1型5个,C2型6个,D型34个.对照组负荷后脑血流平均增加(32.50±3.56)%,SCI组病变半球负荷后血流平均增加(24.18±4.85)%(t=12.39,P<0.01).结论乙酰唑胺负荷脑血流显像可评价SCI患者脑血管储备功能,一日法脑负荷显像简便、安全.     

Delayed epidural hematoma after evacuation of a subdural hematoma

CT easily diagnoses epidural hematomas. The appearance of an epidural hematoma may be delayed by compression from a contralateral lesion. The possibility of a delayed epidural hematoma should be kept in mind in the presence of additional findings such as a skull fracture contralateral to the original lesion or decompression of the epidural hematoma into either the subgaleal or the subarachnoid space. We present a case in which an epidural hematoma declared itself after the evacuation of a contralateral subdural hematoma.     

胸腰椎内固定术后脊髓硬膜外血肿原因分析及其诊治

目的 探讨胸腰椎内同定术后脊髓硬膜外血肿的原因及其诊治。方法 对我院9年来行胸腰椎内固定术的924例患者进行回顾性分析，其中5例患者术后并发脊髓硬膜外血肿，并通过再次行血肿清除减压术得到证实。针对初次手术、术后阶段、再次血肿清除术以及继发的神经症状等方面的情况进行回顾性分析。结果 4例患者初次手术后出现的首发症状均是神经症状的加重，只有1例表现为术后的剧烈疼痛。术后神经症状加重至行血肿清除术的时间平均28．8h。从最初的临床表现异常到血肿清除术的时间为2～14h，平均6h。5例患者血肿清除术后神经症状均有明显改善。结论 尽管胸腰椎内固定术后脊髓硬膜外血肿相对少见，但其后果严重。一旦发现神经症状较术后加再，应及早手术。凝血功能障碍、多节段手术、脊柱翻修术后局部瘢痕化严重是产生血肿的重要危险因素，术者应在手术中彻底止血，并详尽了解所用的止血材料。     

冷冻伤性脑水肿的发生机制及尼莫地平治疗作用的实验研究

目的研究大鼠冷冻伤性脑水肿不同时间脑组织伊文思兰（ＥＢ）、突触体内［Ｃａ２＋］ｉ及Ｃａ２＋－ＡＴＰ酶活性变化与脑含水量变化之间的规律，以探讨冷冻伤性脑水肿的发生机制和类型。方法干湿法测定脑组织水分含量，甲酰胺法测定ＥＢ含量，Ｆｕｒａ－２／ＡＭ荧光标记法测定突触体内［Ｃａ２＋］ｉ，微量定磷法测定线粒体Ｃａ２＋－ＡＴＰ酶活性。采用尼莫地平进行治疗，研究其对ＥＢ含量、［Ｃａ２＋］ｉ、Ｃａ２＋－ＡＴＰ酶活性和脑水肿的影响。结果冷冻伤后３０分钟即已发生Ｃａ２＋超载，伴随Ｃａ２＋－ＡＴＰ酶活性下降及脑组织水分含量及ＥＢ含量增加。尼莫地平治疗后ＥＢ含量和［Ｃａ２＋］ｉ明显下降，而Ｃａ２＋－ＡＴＰ酶活性明显恢复，脑水肿明显减轻。结论ＢＢＢ的通透性增加和细胞内钙通道开放，钙离子浓度超载在脑水肿的发生与发展过程中起了重要作用。冷冻伤性脑水肿在早期既有细胞毒性脑水肿，又有血管源性脑水肿，即混合性脑水肿。     

Human brain hemorrhage: quantification of perihematoma edema by use of diffusion-weighted MR imaging

BACKGROUND AND PURPOSE: Animal models have clearly shown a critical role for extravascular blood in the initiation of the vasogenic edema associated with intracerebral hemorrhage (ICH). Nevertheless, the relevance of these observations to the human disease process has not been evaluated. With a prospectively collected cohort of nine patients, we report the relation between intraparenchymal blood clot volume and elevation of perihematoma brain tissue (and homologous contralateral brain tissue) apparent diffusion coefficient (ADC). METHODS: Patients with acute and subacute supratentorial ICH were prospectively evaluated by using diffusion-weighted imaging. ADC was measured in perihematoma tissue and in homologous contralateral regions. The relationship between ADC and volume of hematoma was determined by using linear regression analysis. RESULTS: Nine patients were enrolled in the study. The mean hematoma volume was 30.8 cc (range, 2.6-74 cc). The ADC in the perihematoma regions was 172.5 x 10(-5) mm(2)/s (range, 120.1-302.5 x 10(-5) mm(2)/s) and in the contralateral corresponding regions of interest was 87.6 x 10(-5) mm(2)/s (range, 76.5-102.1 x 10(-5) mm(2)/s) (P=.02). The Pearson correlation coefficient for the ADC in surrounding edema and hematoma volume was 0.7 (P=.04). The correlation coefficient between hematoma volume and contralateral hemisphere ADC was 0.8 (P=.02). CONCLUSION: We report a significant direct correlation between ICH volume and degree of ADC elevation in perihematoma and ADC values in contralateral corresponding brain tissue. These findings suggest a dose-effect interaction between volume and concentration of blood products and intensity of response that brain tissue exhibits in blood-mediated edema. Prospective natural history and interventional studies are required to confirm this biologically meaningful correlation in patients with ICH.     

Imaging serotonin transporters with 123I-ADAM brain SPECT in healthy non-human primates

BACKGROUND: Serotonin transporters (SERTs) play a major role in modulating serotonergic neuronal function and are the target of many antidepressant drugs used in neuro-psychiatric disorders. To gain more information on the temporal distribution of SERTs, 2-([2-([dimethylamino]methyl)phenoxyl]thio)-5-[I]iodophenylamine (I-ADAM) single photon emission computed tomography (SPECT) was utilized in an in vivo imaging study using non-human primates. METHODS: Two female monkeys (Macaca cyclopis) were studied. Eight brain SPECT imaging examinations, each 30 min in duration, were obtained after injection of 185 MBq of I-ADAM. Images were obtained using a dual-head gamma camera equipped with ultra-high resolution fan-beam collimators. In addition to visual inspection, the radio-uptake and specific uptake ratios (SURs) of midbrain (MB), thalamus (TH), striatum (ST), temporal and frontal cortices and the whole brain in reference to the corresponding magnetic resonance image at the eight time points were measured. The SUR of MB, using cerebellum (CB) as the reference tissue, was calculated as (MB - CB)/CB, in mean counts/pixel. The SURs of the other brain regions were similarly measured. RESULTS: There was relatively high uptake of I-ADAM in the MB and TH, moderate uptake in ST, lower uptake in the cerebral cortex, and almost no uptake in the CB. The image of MB could be easily identified at the first 30 min time point. It appeared that the SURs of MB, TH and ST reached equilibrium around 210 min after injection. No adverse reactions of the primates were found during and after imaging. Brain distribution of I-ADAM in the primate appeared consistent with the known distribution of SERTs. CONCLUSION: In conjunction with a high SUR in MB, TH and ST, we speculate that I-ADAM may be a potential radioligand for SPECT studies of serotonin transporters in humans.     

创伤性后颅窝血肿

目的：总结创伤性后颅窝血肿（THPF）的临床特点。方法：对我科1999年3月-2001年10月间收治并接受手术治疗的9例THPF的病例资料进行回顾性分析。结果：（1）9例均有枕部着力的致伤机制，其中跌倒和低高度坠落伤7例；硬膜外血肿8例，小脑挫裂伤伴小脑血肿1例；（2）就诊时GCS13-15分6例，7例头部外伤后有短暂的昏迷史或创伤后遗忘，4例有头痛或呕吐主诉；（3）8例接受硬膜外血肿清除后颅减压术，1例行小脑血肿清除后颅减压加侧脑室外引流术；其中7例恢复良好，1例中残，1例死亡。结论：THPF有着不同于幕上创伤性颅内血肿的临床特点，及时准确地诊断和积极地治疗是改善预后的关键。     

SPECT studies of brain tumors with L-3-[123I] iodo-alpha-methyl tyrosine: comparison with PET, 124IMT and first clinical results

L-3-[123I]iodo-alpha-methyltyrosine (123IMT) like tyrosine has been reported previously to have a high affinity for a transport system in the blood-brain-barrier (BBB). We examined the kinetic behavior of 124IMT in brain and plasma in two patients with glioblastoma using dynamic positron emission tomography (PET). 124IMT accumulated in brain and tumor tissue, reaching a maximum after 15 min, with a washout of 20% to 35% at 60 min postinjection. Animal experiments confirmed the accumulation of the intact tracer in murine brain, but there was no incorporation into proteins. SPECT studies with 123IMT in patients with different types of brain tumors showed increased uptake in 26 of 32 tumors. Although nonspecific uptake in tumors must be considered, the accumulation of IMT in normal brain and in some tumors with intact BBB suggests a specific uptake of IMT. As transport is the main determinant of initial amino acid uptake, 123IMT appears to be a suitable SPECT tracer of amino acid uptake although it is not incorporated into protein.     

Quantifying brain tumor blood flow by the microsphere model with N-isopropyl-p-[123I]iodoamphetamine super-early SPECT

Regional cerebral blood flow was quantitatively measured in 6 patients with brain tumor by the microsphere model with N-isopropyl-p-[¹²³I]iodoamphetamine (IMP) “super-early” single photon emission computed tomography (SPECT) images obtained 4–6 min after IMP injection with a three-head rotating gamma camera. The ratio of radioactivities (counts/pixel/min) in the “early” SPECT images (taken 25–55 min after IMP injection) to the “super-early” images of the brain tumors was 1.47 ± 0.13 (mean ± SD, n = 6), which was significantly lower than the ratio in the normal cerebral cortices (1.93 ± 0.25) (p < 0.01). This indicates faster clearance of IMP from the tumor tissue than that from the normal brain tissue. Blood flow values for the brain tumors obtained by the microsphere model based on the “super-early” SPECT images were 39.3 ± 12.4 ml/100 g/ min, which was similar to the blood flow values for normal gray matter and in agreement with previous studies with positron emission tomography.     

Synthesis and evaluation of [18F]1-amino-3-fluorocyclobutane-1-carboxylic acid to image brain tumors.

We have developed a new tumor-avid amino acid, 1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC), labeled with 18F for nuclear medicine imaging. METHODS: [18F]FACBC was prepared with high specific activity (no carrier added [NCA]) and was evaluated for its potential in tumor localization. A comparative study was performed for [18F]FACBC and [18F]2-fluorodeoxyglucose (FDG) in which the uptake of each agent in 9L gliosarcoma (implanted intracerebrally in Fisher 344 rats) was measured. In addition, the first human PET study of [18F]FACBC was performed on a patient with residual glioblastoma multiforme. Quantitative brain images of the patient were obtained by using a Siemens 921 47-slice PET imaging system. RESULTS: In the rat brain, the initial level of radioactivity accumulation after injection of [18F]FACBC was low (0.11 percentage injected dose per gram [%ID/g]) at 5 min and increased slightly to 0.26 %ID/g at 60 min. The tumor uptake exhibited a maximum at 60 min (1.72 %ID/g), resulting in a tumor-to-brain ratio increase of 5.58 at 5 min to 6.61 at 60 min. In the patient, the uptake of [18F]FACBC in the tumor exhibited a maximum concentration of 146 nCi/mL at 35 min after injection. The uptake of radioactivity in the normal brain tissue was low, 21 nCi/mL at 15 min after injection, and gradually increased to 29 nCi/mL at 60 min after injection. The ratio of tumor to normal tissue was 6 at 20 min after injection. The [18F]FACBC PET scan showed intense uptake in the left frontal region of the brain. CONCLUSION: The amino acid FACBC can be radiofluorinated for clinical use. [18F]FACBC is a potential PET tracer for tumor imaging.     

Simple quantification of brain perfusion SPECT with IMP using a large field gamma camera

We have developed a simple method to quantitate brain perfusion SPECT with N-isopropyl-p-[123I]iodoamphetamine (IMP). After an intravenous bolus injection of IMP, serial dynamic images of the brain and the lung were obtained every 5 sec for 2 min, followed by a SPECT scan at 20 min. Based on the assumption of IMP as chemical microspheres, fractional uptake (FU) of IMP in the brain was calculated from the time-activity curves of the total brain and the total lungs. FU showed a strong positive correlation with inverse of the body surface area which was calculated from the height and weight of the individual subject, suggesting that FU is influenced by cardiac output. Quantification of IMP brain perfusion SPECT was attempted with FU and estimated cardiac output in each subject, providing an index of regional cerebral blood flow. Compared with PET measurement of regional cerebral blood flow, the present method tended to overestimate the flow values. This method has a great advantage that it can be applied in many institutions having large field gamma cameras. However, the accuracy of the measurement may be limited in the tall subjects and in the cases with cardiopulmonary diseases, and further investigation is required to clarify the usefulness and limitation of this approach.