SPECT肺灌注/低剂量CT融合显像技术在肺栓塞中的诊断价值

目的 探讨SPECT肺灌注与低剂量螺旋CT融合显像(SPECT/CT)技术在肺栓塞(pulmonary embolism,PE)诊断中的临床应用价值.方法 对42例疑似PE患者进行检查,其D-二聚体升高＞0.5mmol/mL或者临床Wells评分＞2,行肺灌注平面显像,采集8个体位.再进行SPECT肺灌注显像与同机低剂量螺旋CT检查,并进行后处理融合,由2位有经验的核医学科医师共同完成图像分析.结果 SPECT/CT的灵敏度、特异性,阳性预测值,阴性预测值及准确性分别为96.43％、92.86％、96.43％、92.86％ 、95.24％,无不确定性结果.结论 SPECT/CT融合显像优于传统的核医学显像方法,灵敏度高,特异性强,有效、简便、准确、无创,可作为诊断PE的一种新的常规影像检查方法.     

SPECT显像在NPC放疗后所致脑损伤中的初步应用

目的评价单光子发射型电子计算机断层(SPECT)脑血流灌注显像在鼻咽癌(NPC)放射治疗后放射性脑损伤中的临床价值. 方法采用SPECT脑血流灌注显像检查,对16例鼻咽癌放射治疗后有放射性脑损伤症状的患者和8例未经放疗的鼻咽癌患者作半定量分析并对测量结果作统计学分析.16例放射性脑损伤患者同期做电子计算机体层检查(CT)对比.结果 16例有放射性脑损伤症状的鼻咽癌患者双侧颞叶局部脑血流灌注(rCBF)在横断面层面-放射性曲线相应部位上可见局部放射性下降峰或曲线变窄小,峰值降低,其曲线局部下降峰值与鼻咽癌放疗剂量的生物效应剂量(BED)值呈正相关(r=0.8976,p<0 .01).8例未经放疗的鼻咽癌患者,在横断面图像上其双侧颞叶局部脑血流灌注的层面-放射性曲线大致呈正态分布曲线,未见异常的局部下降峰或曲线变窄小,峰值未见降低.SPECT显像检查发现鼻咽癌放射治疗后放射性脑损伤的阳性率高于同期CT检查. 结论 SPECT脑血流灌注显像可以早期发现鼻咽癌放疗后所致的放射性脑损伤,并可以作出定性诊断;鼻咽癌患者放疗所致的放射性脑损伤程度与NPC放射治疗的生物效应剂量成正相关.     

核素影像设备的进展

γ相机和单光子发射计算机断层显像术(SPECT)只能进行常规单光子显像,正电子发射断层显像术(PET)和双探头SPECT既能进行单光子显像,又能进行正电子符合显像.PET/CT系统的出现不仅提供高质量的衰减校正图像,保证了正电子显像校正的可靠性,而且能进行同机图像融合,提高了影像定位诊断的准确性.该文简要介绍了核医学影像设备发展历程,PET和PET/CT的原理以及在临床的应用.     

核素脑脊液间隙显像在脑脊液漏中的临床价值

目的 探讨核素脑脊液间隙显像(radionuclide cisternography,RNC)在脑脊液漏(cerebrospinal fluid leak,CSFL)中的诊断价值.方法 回顾分析23例临床可疑CSFL患者RNC的SPECT与SPECT/CT断层融合影像资料,对SPECT与SPECT/CT断层融合影像资料进行对比分析.结果 SPECT、SPECT/CT断层融合显像对CSFL定性诊断灵敏度分别为95.7％、91.3％,两者之间差异无统计学意义;对CSFL定位诊断灵敏度分别为52.2％、87.0％,两者之间差异有统计学意义.结论 RNC的SPECT/CT断层融合显像既可定性CSFL、又可明确CSFL漏口定位,是CSFL诊断的理想影像学检查方法.     

氟[18F]化钠PET/CT临床应用进展

氟[18F]化钠(18F-NaF)是一种正电子发射计算机断层显像(PET)药物,主要用于诊断成骨性反应活跃的骨疾病,尤其是恶性肿瘤骨转移的诊断.由于药物本身的特性以及PET/CT相对于单光子发射计算机断层显像(SPECT)/CT的优势,18F-NaF PET/CT显像相比于99Tc-m亚甲基二膦酸盐(99Tcm-MDP...     

SPECT/CT同机融合显像检测鼻咽癌侵犯颅底骨的临床价值

目的:探讨SPECT/CT同机融合显像对鼻咽癌颅底骨侵犯早期检测的临床价值.方法:对60例鼻咽癌初诊患者,进行全身前后位SPECT骨显像、CT扫描和SPECT/CT同机融合显像,由两位核医学科医生共同做出诊断,对结果进行对比分析.结果:鼻咽癌颅底骨侵犯SPECT阳性检出率46.7%(28/60),CT阳性检出率28.3%(17/60),SPECT/CT同机融合显像阳性检出率55.0%(33/60).SPECT/CT同机融合显像对颅底骨侵犯的阳性检出率与SPECT相比,差异无统计学意义(P＞0.05);颅底骨侵犯SPECT/CT同机融合显像的阳性检出率高于CT,差异有统计学意义(P＜0.05).结论:SPECT/CT同机融合显像对鼻咽癌颅底骨侵犯检测敏感性与单纯SPECT检查相比无明显差异,但明显高于CT,对鼻咽癌颅底骨侵犯早期检测有一定临床价值.     

13N-NH3 PET脑血流灌注显像早期诊断缺血性脑梗死的研究

目的探讨氮-13-氨水(13N-NH3)脑血流灌注显像在早期缺血性脑梗死的诊断价值.方法对5例缺血性脑梗死、10例对照组(无脑血管病史的成年人),在首次CT检查后1小时内静脉注射13NH3* 740～925MBq,3分钟后,行T+E三维方式脑血流灌注显像.图象分析采用视图分析及镜像比值法测量左/右侧相应脑区SUV比值(SUVr).结果对照组左/右脑区SUVr为1.0±0.1.脑梗死组SUVr均<0.7(比值介于0.33～0.69,平均0.51).5例缺血性脑梗死患者共发现病灶12个,明显多于其他影像手段所检出病灶数.结论 13N-NH3PET显像作为一种灵敏度高、定位准确且安全的功能影像学检查手段值得在临床中进行推广,对缺血性脑梗死的早期诊断具有重要临床价值.     

SPECT对发作期小儿癫痫诊断价值分析

目的评价单光子发射型计算机断层扫描脑血流灌注显像对发作期小儿癫痫的诊断价值。方法对38例发作期癫痫患儿行单光子发射型计算机断层扫描检查,并同时行CT检查,把二者结果进行比较。结果单光子发射型计算机断层扫描阳性率为84.2%(32/38),CT阳性率为36.8%(14/38)。两者比较有显著性差异。结论发作期单光子发射型计算机断层扫描显像是诊断小儿癫痫灵敏而有效的方法,对小儿癫痫诊断有重要价值。     

^13N-NH3 PET脑血流灌注显像早期诊断缺血性脑梗死的研究

目的　探讨氮 - 13-氨水 ( 13 N -NH3 )脑血流灌注显像在早期缺血性脑梗死的诊断价值 .方法　对 5例缺血性脑梗死、10例对照组 (无脑血管病史的成年人 ) ,在首次CT检查后 1小时内静脉注射13 NH3 · 74 0～ 92 5MBq ,3分钟后 ,行T E三维方式脑血流灌注显像 .图象分析采用视图分析及镜像比值法测量左 /右侧相应脑区SUV比值 (SU Vr) .结果　对照组左 /右脑区SUVr为 1.0± 0 .1.脑梗死组SUVr均 <0 .7(比值介于 0 .33～ 0 .6 9,平均 0 .5 1) . 5例缺血性脑梗死患者共发现病灶 12个 ,明显多于其他影像手段所检出病灶数 .结论　13 N -NH3 PET显像作为一种灵敏度高、定位准确且安全的功能影像学检查手段值得在临床中进行推广 ,对缺血性脑梗死的早期诊断具有重要临床价值 .     

SPECT/CT在骨显像骨外放射性分布异常诊断中的增益价值

目的 评价⁹⁹Tc^m-MDP SPECT/CT在骨显像中骨外放射性分布异常诊断中的增益价值。方法 回顾性分析2016年1月至2023年2月在我院行全身骨显像检查并同时行SPECT/CT检查的35例骨外放射性分布异常患者的临床资料，以病理、影像或临床随访为依据，分析⁹⁹Tc^m-MDP平面显像及SPECT/CT断层融合显像对骨外放射性分布异常的定位、定性诊断能力。结果 本文35例患者共41处骨外放射性分布异常病灶，其中全身平面骨显像定位准确14处(34.1%,14/41),SPECT/CT定位准确41处(100%,41/41),两者比较差异有统计学意义(χ²=40.26,P<0.05);SPECT/CT确定诊断35处(85.4%,35/41),全身平面骨显像确定诊断仅8处(19.5%,8/41),两者诊断准确率比较差异有统计学意义(χ²=35.65,P<0.05)。结论 与全身平面骨显像比较，SPECT/CT显像在骨显像骨外放射性分布异常诊断中能够...     

SPECT显像在NPC放疗后所致脑损伤中的初步应用

目的 评价单光子发射型电子计算机断层（ＳＰＥＣＴ）脑血流灌注显像在鼻咽癌（ＮＰＣ）放射治疗后放射性脑损伤中的临床价值。方法 采用ＳＰＥＣＴ脑血流灌注显像检查,对１６例鼻咽癌放射治疗后有放射性脑损伤症状的患者和８例示经放疗的鼻咽癌患者作半定时分析对测量结果作统计学分析。１６例放射性脑损伤患者同期做电子计算机体层检查（ＣＴ）对比。结果 １６例有放射性脑损伤症状的鼻咽癌患者双侧颞叶局部脑血流灌注（ｒＣＢＦ）在横断面层面－放射性曲线相应部位上可见局部放射性下降峰或曲线变窄小,峰值降低,其曲线局部下降峰值与鼻咽癌放疗效量的生物效应剂量（ＢＥＤ）值呈正相关（ｒ＝０．８９７６,Ｐ〈０．０１）。８例未经放疗的鼻咽癌患者,在横断面图像上其双侧颞叶局部脑血流灌注的层面－放射性曲线大致呈正态分布曲线,未见异常的局部下降峰或曲线变窄小     

阻塞性睡眠呼吸暂停的脑血流灌注成像研究进展

阻塞性睡眠呼吸暂停（OSA）是一种常见的睡眠呼吸障碍,可致局部脑血流量改变,脑血流灌注成像对于评估OSA严重程度及预后进展具有重要意义。目前应用于评估OSA患者脑血流灌注的成像技术主要包括单光子发射计算机断层显像、磁共振脑血流灌注成像等。本研究旨在对脑血流灌注成像技术在OSA的研究进展进行综述,客观分析各脑血流灌注技术的优势和局限,以期提高各技术在OSA的早期筛查、评价疾病严重程度以及预后进展的临床适用性,并展望未来研究方向和提出目前潜在的挑战。     

Rodent brain imaging with SPECT/CT

We evaluated methods of imaging rat models of stroke in vivo using a single photon emission computed tomography (SPECT) system dedicated to small animal imaging (X-SPECT, Gamma Medica-Ideas, Northridge, CA). An animal model of ischemic stroke was developed for in vivo SPECT/CT imaging using the middle cerebral artery occlusion (MCAO) technique. The presence of cerebral ischemia was verified in ex vivo studies using triphenyltetrazolium chloride (TTC) staining. In vivo radionuclide imaging of cerebral blood flow was performed in rats following MCAO using dynamic planar imaging of 99mTc-exametazime with parallel hole collimation. This was followed immediately by in vivo radionuclide imaging of cerebral blood flow with 99mTc-exametazime in the same animals using 1-mm pinhole SPECT. Correlated computed tomography imaging was performed to localize radiopharmaceutical uptake. The animals were allowed to recover and ex vivo autoradiography was performed with separate administration of 99mTc-exametazime. Time activity curve of 99mTc-exametazime showed that the radiopharmaceutical uptake could be maintained for over 9 min. The activity would be expected to be relatively stable for a much longer period, although the data were only obtained for 9 min. TTC staining revealed sizable infarcts by visual observation of inexistence of TTC stain in infracted tissues of MCAO rat brains. In vivo SPECT imaging showed cerebral blood flow deficit in the MCAO model, and the in vivo imaging result was confirmed with ex vivo autoradiography. We have demonstrated a capability of imaging regions of cerebral blood flow deficit in MCAO rat brains in vivo using a pinhole SPECT dedicated to small animal imaging.     

Assessment of regional cerebral blood flow (rCBF) in ischemic stroke using Tc-99m HMPAO SPECT--comparison with CT and MR findings

To assess the regional cerebral blood flow (rCBF) in ischemic stroke, we analyzed the findings of single photon emission computed tomography (SPECT) using technetium-99m hexamethyl propyleneamine oxime (Tc-99m HMPAO). The SPECT images revealed abnormal areas of decreased perfusion in 29 out of 31 subjects (93.5%), which represented a higher detection rate than those for CT and MR (89.5%, respectively). Also, the areas of decreased perfusion were frequently larger than the lesions on CT and MR. Areas of decreased perfusion remote from the CT/MR lesions were found in 10 patients, including 8 with crossed cerebellar diaschisis (CCD). Thus, studies of rCBF by Tc-99m HMPAO SPECT can be useful in the assessment of ischemic stroke.     

CT灌注成像评价颅骨缺损修复前后 脑血流量变化的临床研究

目的 通过CT灌注成像（CTP）观察颅骨成形术患者脑血流量的变化。方法 对20例颅骨缺损修复的患者进行脑CT灌注成像,在颅骨修复术前和术后2周进行CTP。记录大脑皮层、基底节区脑血流容量（CBV）、脑血流流量（CBF）、造影剂平均通过时间（MMT）和对比剂达到峰值的时间（TTP）等所有参数,分析脑皮层和基底节区血流灌注数据的变化。结果 颅骨修复术前患侧脑皮层区的CBV和CBF值均低于健侧,TTP和MTT值均高于健侧,差异均具有统计学意义（P＜0.05）。修复术后患侧脑皮层的CBF、CBV值均有提高,患侧脑皮层的MTT、TTP值较术前降低,差异均具有统计学意义（P＜0.05）。患侧术后脑皮层的CBV、CBF、MTT、TTP值与健侧比较无统计学意义（P＞0.05）。结论 CT灌注成像能及时发现脑血流变化情况,颅骨修复可以增加脑皮层区脑血流量,促进神经功能恢复。     

CT脑肿瘤灌注特征参数定量分析与研究

目的：在研究CT脑肿瘤灌注成像过程中,肿瘤相关特征参数的定量分析为临床诊断提供重要依据。方法：介绍了CT脑灌注的相关参数,包括脑血流量（CBF）、脑血容量（CBV）、平均通过时间（MTT）和表面通透性等（PS）,根据CT扫描所获得的一系列时间影像序列,利用VisualC＋＋编程实现了脑肿瘤区域的时间密度曲线的显示,在基于去卷积方法基础之上,提出改进的算法,结合CT灌注图像上肿瘤区域的长度,角度,面积等参数的测量方法,计算出更精确地血流动力学参数。结论：脑肿瘤CT灌注图像相关特征参数的定量分析可用于脑瘤的及时诊断和治疗。     

Imaging methods for evaluating brain function in man

Imaging of brain function and neurotransmission is an important bridge between basic and clinical research. Regional cerebral energy metabolism and blood flow are normally coupled to regional cerebral function. Positron tomography (PET) studies of cerebral glucose metabolism and blood flow, single photon tomography (SPECT) and MRI studies of cerebral perfusion, have been used to image cerebral development and aging in man. The sensitivity, temporal resolution, spatial resolution and lack of radiation have led to the widespread utilization of blood oxygen level dependent (BOLD) and MRI perfusion techniques. PET and SPECT methods for studying cerebral neurotransmission include studies of dopaminergic, serotonergic, cholinergic, opiate and GABAergic neurotransmission in man. Studies of cerebral neurotransmission in man have helped to delineate the mechanisms of action of antipsychotic and antidepressant drugs, the diagnosis and progression of Parkinson's disease, and to evaluate neuroprotective drugs. The strengths, limitations, and application of these modalities are reviewed. The application of these methods to cerebral development and aging are briefly discussed.     

Investigation of dynamic SPECT measurements of the arterial input function in human subjects using simulation, phantom and human studies

Computer simulations, a phantom study and a human study were performed to determine whether a slowly rotating single-photon computed emission tomography (SPECT) system could provide accurate arterial input functions for quantification of myocardial perfusion imaging using kinetic models. The errors induced by data inconsistency associated with imaging with slow camera rotation during tracer injection were evaluated with an approach called SPECT/P (dynamic SPECT from positron emission tomography (PET)) and SPECT/D (dynamic SPECT from database of SPECT phantom projections). SPECT/P simulated SPECT-like dynamic projections using reprojections of reconstructed dynamic (94)Tc-methoxyisobutylisonitrile ((94)Tc-MIBI) PET images acquired in three human subjects (1 min infusion). This approach was used to evaluate the accuracy of estimating myocardial wash-in rate parameters K(1) for rotation speeds providing 180° of projection data every 27 or 54 s. Blood input and myocardium tissue time-activity curves (TACs) were estimated using spatiotemporal splines. These were fit to a one-compartment perfusion model to obtain wash-in rate parameters K(1). For the second method (SPECT/D), an anthropomorphic cardiac torso phantom was used to create real SPECT dynamic projection data of a tracer distribution derived from (94)Tc-MIBI PET scans in the blood pool, myocardium, liver and background. This method introduced attenuation, collimation and scatter into the modeling of dynamic SPECT projections. Both approaches were used to evaluate the accuracy of estimating myocardial wash-in parameters for rotation speeds providing 180° of projection data every 27 and 54 s. Dynamic cardiac SPECT was also performed in a human subject at rest using a hybrid SPECT/CT scanner. Dynamic measurements of (99m)Tc-tetrofosmin in the myocardium were obtained using an infusion time of 2 min. Blood input, myocardium tissue and liver TACs were estimated using the same spatiotemporal splines. The spatiotemporal maximum-likelihood expectation-maximization (4D ML-EM) reconstructions gave more accurate reconstructions than did standard frame-by-frame static 3D ML-EM reconstructions. The SPECT/P results showed that 4D ML-EM reconstruction gave higher and more accurate estimates of K(1) than did 3D ML-EM, yielding anywhere from a 44% underestimation to 24% overestimation for the three patients. The SPECT/D results showed that 4D ML-EM reconstruction gave an overestimation of 28% and 3D ML-EM gave an underestimation of 1% for K(1). For the patient study the 4D ML-EM reconstruction provided continuous images as a function of time of the concentration in both ventricular cavities and myocardium during the 2 min infusion. It is demonstrated that a 2 min infusion with a two-headed SPECT system rotating 180° every 54 s can produce measurements of blood pool and myocardial TACs, though the SPECT simulation studies showed that one must sample at least every 30 s to capture a 1 min infusion input function.     

SPECT changes and their correlation with EEG changes in tuberculous meningitis

OBJECTIVE: In tuberculous meningitis (TBM) blood flow may be altered due to associated vasculitis, hydrocephalus and raised intracranial pressure. Electroencephalography (EEG) and single photon emission computed tomography (SPECT) provide information about electrical activity and regional cerebral blood flow respectively. This study aims at the correlation of EEG and SPECT changes in patients with TBM. METHOD: Sixteen patients with TBM whose age ranged between 5 and 62 years and 3 of whom were females were subjected to clinical, radiological (CT and/or MRI), EEG and SPECT studies using 99mTc ethylene cystine dimer (ECD). Ten patients were in stage III and 3 each in stage II and stage I meningitis. Cranial CT scan was carried out in 15 and MRI in 4 patients. Hydrocephalus was present in 9, infarction in 7 and tuberculoma in 5 patients. RESULTS: SPECT studies were abnormal in all except 2 patients revealing basal ganglionic hypoperfusion in 14 and focal cortical hypoperfusion in 9 patients. The EEG was abnormal in 11 patients which included delta slowing in 5, theta slowing in 6, frontal intermittent rhythmic delta activity (FIRDA) in 3 and epileptiform discharges in 2 patients. All the patients with abnormal EEG had abnormal SPECT study except 1. In 4 patients, EEG was normal although there was subcortical hypoperfusion on SPECT. In spite of high frequency of focal cortical hypoperfusion (9 patients), EEG revealed focal abnormality in 3 patients only. CONCLUSION: It can be concluded that the SPECT reveals more frequent abnormalities compared to EEG and CT scan. Cortical hypoperfusion with or without basal ganglia hypoperfusion is associated with FIRDA and diffuse delta slowing on EEG.