Complementarity of magnetic resonance spectroscopy, positron emission tomography and single photon emission tomography for the in vivo investigation of human cardiac metabolism and neurotransmission.

The three techniques allowing the noninvasive study of cardiac metabolism, namely magnetic resonance spectroscopy (MRS), positron emission tomography (PET) and single photon emission computed tomography (SPET), all use external detection with stable or radioactive isotopes. These techniques yield different information. PET is quantitative and very sensitive, and therefore only tracer amounts of molecules need to be injected. It allows neurotransmitters and receptors to be studied and a global view of metabolism (oxygen consumption, glucose and fatty acid utilization) to be obtained. SPET also has good sensitivity, but uses gamma-emitting isotopes of heteroatoms. Their longer half-lives allow follow-up for hours or days. MRS is based on stable elements with high (hydrogen 1, phosphorus 31, fluorine 19...) or low (carbon 13, Deuterium) natural abundance. It has very low sensitivity and only millimolar concentrations of substrates can be detected, but various parts of metabolism can be studied. The in vivo measurement of myocardial concentration of substances has many problems that are common to all three techniques (measurement of the volume, measurement of the quantity of each molecule, resolution, partial volume effect, improvement of the signal-to-noise ratio, movement of the organ). The complementarity of the techniques is illustrated by their applications to the study of cardiac metabolism. For instance, the energy metabolism can be studied by 31P-MRS, which detects the high-energy compounds ATP and phosphocreatine, and 13C-MRS yields information on the tricarboxylic acid cycle activity. PET and SPET allow the utilization of fatty acids, the normal fuels of the heart, to be studied. During ischaemia, PET with 18F-fluorodeoxyglucose (18FDG) can determine the glucose consumption and 1H-MRS shows the increase in lactic acid, reflecting anaerobic glycolysis. Comparison of the use of acetate labelled with 11C for PET or 13C for MRS shows the potentials and limitations of each technique. Myocardial perfusion can be evaluated directly with various PET tracers or indirectly with thallium 201 or various technetium-99m-labelled tracers by SPET. No MRS marker of perfusion is so far clinically available. Mainly SPET and PET are used clinically for the investigation of ischaemic heart disease as well as cardiomyopathies, but some initial results using 31P-MRS are being obtained.     

PET/MRI在肺癌中的潜在临床应用价值

PET/MRI作为新出现的融合影像技术,其临床应用价值尚未得到充分证实。与CT相比,MRI具有软组织对比分辨力高、无辐射、多参数成像、能够提供更多功能信息的优势,PET与MRI的融合对于肺癌的潜在应用价值可能要优于PET/CT。简述不同的PET/MRI系统的设计,并从肺结节的检出、鉴别诊断、TNM分期、预后/早期疗效评价/肿瘤复发4个方面介绍PET/MRI在肺癌中的潜在临床价值。     

Remote metabolic effects of cerebrovascular lesions: magnetic resonance and positron tomography imaging

Summary Combined Positron Emission Tomography (PET) and Proton Magnetic Resonance Imaging (MRI) study were performed in six patients with chronic supratentorial stroke to investigate whether remote hypometabolic regions revealed by PET showed any abnormality on MRI. Either regional oxygen consumption (n=4) or glucose utilization (n=2) were measured using PET and the ¹⁵O steady state ¹⁸FGD technique, respectively. Four patients, with deeply located brain lesions, showed a significant metabolic reduction in the overlying cerebral cortex. In the remaining two patients, affected by a large cortical infarct, there was a significant crossed cerebellar hypometabolism. The MRI weighted by the parameters spin density (), spin lattice (T₁) and spin-spin (T₂) relaxation times were obtained employing various sequences in the same subjects. In no patient did the MRI show any contrast modification in these hypometabolic remote regions, suggesting that subtle loss of tissue and/or biochemical change do not underlie the reduction in metabolic rate.     

In vivo neurochemistry with emission tomography and magnetic resonance spectroscopy: clinical applications

The assessment of neurochemical processes in vivo has received much attention in the past decade as techniques such as positron or single photon emission tomography (PET and SPET), and magnetic resonance spectroscopy (MRS) have become more available. With PET and SPET, basic processes, such as blood flow and oxygen or glucose metabolism, can be regionally assessed, along with more specific functions such as the production, release, and reuptake of neurotransmitters and their occupancy of specific receptors. At the same time, MRS can reveal changes in concentration of several hydrogenate compounds in the brain. All these methods have been extensively applied for research in neurology, and some applications have reached the clinical level, namely for the study of degenerative diseases, motor-neuron diseases, movement disorders, cerebrovascular diseases, and epilepsy. This article focuses on the most relevant information that can be obtained with these complementary techniques to help clinicians in the assessment of neurological diseases.     

Recurrent ovarian endodermal sinus tumor: demonstration by computed tomography,magnetic resonance imaging,and positron emission tomography

We report a case of recurrent endodermal sinus tumor.of the ovary that was identified and/or clearly depicted by computed tomography, magnetic resonance imaging, and positron emission tomography. The potential roles of various imaging modalities in the detection of recurrent endodermal sinus tumor are discussed.     

Computer tomography, magnetic resonance imaging, and positron emission tomography or positron emission tomography/computer tomography for detection of metastatic lymph nodes in patients with ovarian cancer: a meta-analysis

Objectives

To compare the diagnostic performances of computed tomography (CT), magnetic resonance (MR) imaging, and positron emission tomography (PET or PET/CT) for detection of metastatic lymph nodes in patients with ovarian cancer.

Methods

Relevant studies were identified with MEDLINE and EMBASE from January 1990 to July 2010. We estimated the weighted summary sensitivities, specificities, OR (odds ratio), and summary receiver operating characteristic (sROC) curves of each imaging technique and conducted pair-wise comparisons using the two-sample Z-test. Meta-regression, subgroup analysis, and funnel plots were also performed to explain the between-study heterogeneity.

Results

Eighteen eligible studies were included, with a total of 882 patients. PET or PET/CT was a more accurate modality (sensitivity, 73.2%; specificity, 96.7%; OR [odds ratio], 90.32). No significant difference was detected between CT (sensitivity, 42.6%; specificity, 95.0%; OR, 19.87) and MR imaging (sensitivity, 54.7%; specificity, 88.3%; OR, 12.38). Meta-regression analyses and subgroup analyses revealed no statistical difference. Funnel plots with marked asymmetry suggested a publication bias.

Conclusion

FDG-PET or FDG-PET/CT is more accurate than CT and MR imaging in the detection of lymph node metastasis in patients with ovarian cancer.     

Assessment of malignancy of glioma by positron emission tomography with 18F-fluorodeoxyglucose and single photon emission computed tomography with thallium-201 chloride

The histological diagnosis and proliferative potential measured by bromodeoxyuridine (BrdU) labelling index (LI) were corelated with preoperative CT and contrast-enhanced, MRI, ¹⁸F-flurodeoxyglucose positron emission tomography (PET) and ²⁰¹T1 single photon emission computed tomography (SPECT) in 43 patients with various grades of glioma. ²⁰¹T1 SPECT had slightly higher sensitivity to tumours with BrdU LI N 5 % (showing 10/10) than ¹⁸F-FDG PET (7/8 tumours). ¹⁸F-FDG PET was better for identifying tumours of BrdU LI < 1 % (13/15) than ²⁰¹T1 SPECT (13/22). Accumulation of ²⁰¹T1 in the tumour was slightly different from contrast enhancement on CT and/or MRI, and gave “false-postive” results in some low-grade gliomas. However, ²⁰¹T1 SPECT, which is available in many hospitals and may cost less, provided useful information to supplement that from CT and MRI. Received: 25 November 1996 Accepted: 8 September 1997     

Simultaneous whole body 18F-fluorodeoxyglucose positron emission tomography magnetic resonance imaging for evaluation of pediatric cancer: Preliminary experience and comparison with 18F-fluorodeoxyglucose positron emission tomography computed tomography

AIM: To describe our preliminary experience with simultaneous whole body ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography and magnetic resonance imaging (PET-MRI) in the evaluation of pediatric oncology patients.METHODS: This prospective, observational, single-center study was Health Insurance Portability and Accountability Act-compliant, and institutional review board approved. To be eligible, a patient was required to: (1) have a known or suspected cancer diagnosis; (2) be under the care of a pediatric hematologist/oncologist; and (3) be scheduled for clinically indicated ¹⁸F-FDG positron emission tomography-computed tomography (PET-CT) examination at our institution. Patients underwent PET-CT followed by PET-MRI on the same day. PET-CT examinations were performed using standard department protocols. PET-MRI studies were acquired with an integrated 3 Tesla PET-MRI scanner using whole body T1 Dixon, T2 HASTE, EPI diffusion-weighted imaging (DWI) and STIR sequences. No additional radiotracer was given for the PET-MRI examination. Both PET-CT and PET-MRI examinations were reviewed by consensus by two study personnel. Test performance characteristics of PET-MRI, for the detection of malignant lesions, including FDG maximum standardized uptake value (SUVmax) and minimum apparent diffusion coefficient (ADCmin), were calculated on a per lesion basis using PET-CT as a reference standard.RESULTS: A total of 10 whole body PET-MRI exams were performed in 7 pediatric oncology patients. The mean patient age was 16.1 years (range 12-19 years) including 6 males and 1 female. A total of 20 malignant and 21 benign lesions were identified on PET-CT. PET-MRI SUVmax had excellent correlation with PET-CT SUVmax for both benign and malignant lesions (R = 0.93). PET-MRI SUVmax > 2.5 had 100% accuracy for discriminating benign from malignant lesions using PET-CT reference. Whole body DWI was also evaluated: the mean ADCmin of malignant lesions (780.2 + 326.6) was significantly lower than that of benign lesions (1246.2 + 417.3; P = 0.0003; Student’s t test). A range of ADCmin thresholds for malignancy were evaluated, from 0.5-1.5 × 10^-3 mm²/s. The 1.0 × 10^-3 ADCmin threshold performed best compared with PET-CT reference (68.3% accuracy). However, the accuracy of PET-MRI SUVmax was significantly better than ADCmin for detecting malignant lesions compared with PET-CT reference (P < 0.0001; two-tailed McNemar’s test).CONCLUSION: These results suggest a clinical role for simultaneous whole body PET-MRI in evaluating pediatric cancer patients.     

MRI and 18F-fluorodeoxyglucose positron emission tomography in hemimegalencephaly

We report hemimegalencephaly in a 44-year-old woman with mental retardation, epilepsy and a mild hemiparesis. In addition to typical findings on MRI, 2-deoxy-2[¹⁸F]fluorodeoxyglucose positron-emission tomography (PET) demonstrated glucose hypometabolism of the affected hemisphere. The results of PET have been coregistered with morphological information from the MRI studies by image fusion. Received: 14 December 1999/Accepted: 15 February 2000     

A comparison of rest sestamibi and rest-redistribution thallium single photon emission tomography: Possible implications for myocardial viability detection in infarcted patients

Thirty patients (26 men, 4 women, mean age 61 ± 8 years) who had suffered myocardial infarction 15 ± 6 months previously, were submitted to (1) standard stress-redistribution thallium-201 single photon emission tomography (SPET), (2) rest-redistribution²⁰¹Tl SPET and (3) stress-rest technetium-99m sestamibi SPET. Uptake modifications in relation to exercise-induced defects were evaluated in a total of 390 myocardial segments. Tracer uptake was scored as normal (=0), mildly reduced (=1), apparently reduced (=2), severely reduced (=3) or absent (=4). Comparison of stress studies failed to show any statistical difference (58% segmental abnormalities with sestamibi vs 61% with thallium). Uptake abnormalities (score 1–4) were detected in 55% of the segments wiliest sestamibi, 55% with standard thallium redistribution, 55% with early imaging after thallium injection at rest and 54% with 3-h delayed rest imaging (P = NS). Absence of tracer uptake (score = 4) under resting conditions was recorded in 75 (19%) segments with standard²⁰¹Tl redistribution, 75 (19%) with rest sestamibi, 70 (18%) with rest²⁰¹Tl imaging and 62 (16%) with rst-rdistruion²⁰¹Tl (P<0.05 vs other imaging modalities). Thus, 3-h delayed rest thallium imaging detected reversibility of uptake defects in a significantly higher number of myocardial segments. This finding might have important implications for both tracer and technique selection when myocardial viability is the main clinical issue.     

Presurgical identification of hibernating myocardium by combined use of technetium-99m hexakis 2-methoxyisobutylisonitrile single photon emission tomography and fluorine-18 fluoro-2-deoxy-d-glucose positron emission tomography in patients with coronary artery disease

We tested the possibility of identifying areas of hibernating myocardium by the combined assessment of perfusion and metabolism using single photon emission tomography (SPET) with technetium-99m hexakis 2-methoxyisobutylisonitrile (^99mTc-MIBI) and positron emission tomography (PET) with fluorine-18 fluoro-2-deoxy-d-glucose (¹⁸F-FDG). Segmental wall motion, perfusion and ¹⁸F-FDG uptake were scored in 5 segments in 14 patients with coronary artery disease (CAD), for a total number of 70 segments. Each subject underwent the following studies prior to and following coronary arterybypass grafting (CABG): first-pass radionuclide angiography, electrocardiography gated planar perfusion scintigraphy and SPET perfusion scintigraphy with ^99mTc-MIBI and, after 16 h fasting, ¹⁸F-FDG/PET metabolic scintigraphy. Wall motion impairment was either decreased or completely reversed by CABG in 95% of the asynergic segments which exhibited ¹⁸F-FDG uptake, whereas it was unmodified in 80% of the asynergic segments with no ¹⁸-FDG uptake. A stepwise multiple logistic analysis was carried out on the asynergic segments to estimate the postoperative probability of wall motion improvement on the basis of the preoperative regional perfusion and metabolic scores. The segments with the highest probability (96%) of functional recovery from preoperative asynergy after revascularization were those with a marked ¹⁸F-FDG uptake prior to CABG. High probabilities of functional recovery were also estimated for the segments presenting with moderate and low ¹⁸F-FDG uptake (92% and 79%, respectively). A low probability of functional recovery (13 %) was estimated in the segments with no ¹⁸F-FDG uptake. Despite the potential limitations due to the semiquantitative analysis of the images, the method appears to provide reliable information for the diagnostic and prognostic evaluation of patients with CAD undergoing CABG and confirms that the identification of hibernating myocardium with ¹⁸F-FDG is of paramount importance in the diagnosis of patients undergoing CABG.Correspondence to: G. Lucignani     

The significance of a dipyridamole induced 99mTc-MIBI perfusion abnormality on single photon emission tomography: a quantitative validation with labelled water and positron emission tomography

To relate technetium-99m 2-methoxy-isobutylisonitrile (^99mTc-MIBI) uptake to regional myocardial blood flow (rMBF), ^99mTc-MIBI single photon emission tomography (SPET) and H₂ ¹⁵O positron emission tomography (PET) scans were obtained at rest and after dipyridamole infusion in six patients with single vessel coronary artery disease. ^99mTc-MIBI and H₂ ¹⁵O data sets were created for each segment perfused by the stenotic vessel and for a normal reference area, assigning regions on the SPET tomograms to comparable regions on the PET by similar transaxial image reconstructions. All patients demonstrated post-dipyridamole ^99mTc-MIBI perfusion defects in the territories supplied by the stenotic arteries. Resting rMBF in these regions was slightly lower than that in the normal areas (0.82±0.05 vs 0.90±0.09 ml/g/min, P=NS). A 43%±14% reduction in ^99mTc-MIBI activity in the area at risk was coupled with on average a 60%±9% reduction in post-dipyridamole rMBF compared with control regions (0.98±0.08 vs 2.52±0.51 ml/g/min, P<0.001). Thus, SPET assessment of ^99mTc-MIBI uptake tends to underestimate the perfusion contrast between areas with normal and areas with low coronary vasodilatory reserve when compared to PET. However, these findings may still not affect the clinical usefulness of ^99mTc-MIBI and more extensive studies are required to confirm these results in the clinical environment.     

Comparison of thallium-201 single-photon emission tomography after rest injection and fluorodeoxyglucose positron emission tomography for assessment of myocardial viability in patients with chronic coronary artery disease

This prospective study in 42 patients with chronic coronary artery disease and severe wall motion abnormalities (sWMA) on cineventriculography (24 patients with previous myocardial infarction; ejection fraction, 45%±13%) was designed to compare myocardial thallium-201 uptake after rest injection and normalized fluorodeoxyglucose (¹⁸FDG) uptake (after oral glucose load) for assessment of a rest ²⁰¹Tl protocol to evaluate myocardial viability. The left ventricle was divided into the supply territory of the left anterior descending coronary artery (LAD) and the lateral wall and posterior territory (inferior, posterior and posteroseptal segments) because of the high variability of left circumflex and right coronary artery supply territories. Segmental ²⁰¹Tl uptake in single-photon emission tomography (SPET) and segmental normalized ¹⁸FDG uptake (13 segments per patient) showed a close linear relationship in the LAD territory (r=0.79) and in the lateral wall (r=0.77), while the correlation in the posterior territory was considerably lower (r=0.52). ²⁰¹Tl/¹⁸FDG concordance was defined as an ¹⁸FDG uptake exceeding ²⁰¹Tl uptake by < 20%. Discordance was assumed if ¹⁸FDG exceeded ²⁰¹Tl uptake by at least 20%. Concordant results were shown by 81% (439/541) of segments. In segments with severe ²⁰¹Tl reduction ( 50% of peak, n=78) discordance was observed in 10% of segments in the LAD territory and lateral wall (n=62) and in 44% of segments in the posterior territory (n=16). In segments with moderate ²⁰¹Tl reduction (51%–75%, n=205) discordance occured in 12% (LAD and lateral wall, n=126) or 46% (posterior territory, n=79) of segments, respectively. Severe defects were defined as the entire area with ²⁰¹Tl uptake 50% within a defined territory. Discordance was observed in 6/43 (14%) of these. Of 90 areas with sWMA on cineventriculography, 12 showed discordant results. Ten of these 12 discordant areas affected septum or posterior wall. In areas with normal wall motion or only mild hypokinesis, discordance occured in the septum or posterior wall in 22% whereas the figure for the anterior or lateral wall was only 2%. These results point to a significant role of photon attenuation in ²⁰¹Tl SPET imaging in the septum and posterior wall. It is concluded that ²⁰¹Tl SPET using a rest protocol identifies viable myocardium in the supply area of the LAD and in the lateral wall with high accuracy compared to ¹⁸FDG positron emission tomography while disordance in the posterior territory may be governed by photon attenuation in the SPET study rather than by a pathophysiological difference. Correspondence to: C. Aftehoefer     

Imaging diabetes mellitus with coronary computed tomography angiography, cardiovascular magnetic resonance, and positron emission tomography

The prevalence and medical expense associated with diabetes mellitus continue to increase. Using the diagnostic imaging techniques of coronary computed tomography angiography, cardiovascular magnetic resonance, and positron emission tomography, it may be possible to make earlier, non-invasive diagnoses of the type and extent of disease, thereby preventing or delaying some morbidity and mortality.     

Utility of positron emission tomography-magnetic resonance imaging in musculoskeletal imaging

Differentiation between neoplastic and nonneoplastic conditions magnetic resonance imaging (MRI) has established itself as one of the key clinical tools in evaluation of musculoskeletal pathology. However, MRI still has several key limitations which require supplemental information from additional modalities to complete evaluation of various disorders. This has led to the development hybrid positron emission tomography (PET)-MRI which is rapidly evolving to address key clinical questions by using the morphological strengths of MRI and functional information of PET imaging. In this article, we aim to review physical principles and techniques of PET-MRI and discuss clinical utility of functional information obtained from PET imaging and structural information obtained from MRI imaging for the evaluation of musculoskeletal pathology. More specifically, this review highlights the role of PET-MRI in musculoskeletal oncology including initial diagnosis and staging, treatment planning and post-treatment follow-up. Also we will review utility of PET-MRI in evaluating musculoskeletal infections (especially in the immunocompromised and diabetics) and inflammatory condition. Additionally, common pitfalls of PET-MRI will be addressed.     

Comparison of thallium-201 and technetium-99m teboroxime myocardial single photon emission tomography with coronary arteriography

Myocardial single photon emission tomography (SPET) using technetium-99m teboroxime (teboroxime) was studied and the results compared with those of thallium-201(thallium) SPET and coronary arteriography in 19 patients. Resting teboroxime SPET was performed initially. Two hours later, exercise teboroxime SPET was performed. Exercise ergometer tests for both teboroxime and thallium were carried out in a supine position. The levels of exercise achieved for both tests were similar. Agreement for the identification of myocardial segments between thallium SPET and teboroxime SPET was 147/171(86%) (NS). When a significant stenosis was defined as 75% or 50%, agreement between two radiopharmaceuticals for the detection of diseased vessels was 89% (NS, = 0.601) or 88% (NS, = 0.713), respectively. In only 2/19 cases were inferior and posterior segments (3/171) difficult to interpret in teboroxime SPET due to hepatic activity. Thus, teboroxime SPET with a short data acquisition time resulted in a rapid completion for each study and had a good correlation with thallium SPET. Offprint requests to: M. Oshima, M.D., Ph.D. Department of Radiology Nagoya First Red Cross Hospital     

SPECT在冠心病危险度分层方面的应用

应用门控心肌灌注SPECT测得的心肌灌注缺损和负荷后左室射血分数(left ventricular ejection fraction,LVEF)相结合进行危险度分层,对非致死性心肌梗死和心脏性死亡的风险进行评估以指导临床选择最佳治疗方案。对于射血分数(ejection fraction, EF) ≥ 30%,总差值分(即总负荷评分与总静息评分的差值,summed difference score, SDS)>7的中高危患者,宜进行血流重建术(revascularization);SDS为2~7的患者,若EF>50%则为低危,可给予药物治疗,而EF为30%~50%者则予药物治疗及血流重建术;若为未见心肌缺血的极低危患者,则宜药物治疗。     

Improving the quantitation accuracy in noninvasive small animal single photon emission computed tomography imaging

Introduction

Noninvasive imaging of small animals to measure biodistributions and pharmacokinetics of radiolabeled agents is increasingly seen as an effective alternative to external counting of tissues obtained by sacrifice and dissection. However, we have observed important disagreements in measuring the accumulation of ¹¹¹In-labeled antibodies in organs such as liver and kidneys when comparing imaging to ex vivo counting in the same animals. This study was conducted to establish whether this discrepancy could be minimized by selecting the region of interest (ROI) in images at the appropriate color threshold and by correcting for the estimated radioactivity within the blood pool of these organs during imaging.

Methods

Vials with known concentrations of ¹¹¹In as phantoms were imaged on a Bioscan NanoSPECT/CT. Thereafter, an ¹¹¹In-DTPA-IgG antibody as the test agent was administered intravenously to normal rats, and whole body acquisitions were obtained at 2, 24 or 48 h. Immediately following imaging, the animals were sacrificed, the tissues were removed for ex vivo counting and the radioactivity accumulations were then compared.

Results

The phantom measurements showed that accuracy depended upon setting the correct ROI and that, in turn, depended upon setting the appropriate threshold of the color scale. Under the most unfavorable conditions, this error did not exceed 60%. Compared to the results of ex vivo counting, quantitation by imaging provided high values in liver and kidneys at all three time points by as much as 140%. However, by using the blood radioactivity at the time of sacrifice and the known blood volume in these organs, the disagreement was reduced in all cases to below 25%.

Conclusion

In this study, the discrepancy in quantitating organ radioactivity accumulations between noninvasive imaging and necropsy was primarily due to blood pool radioactivity contributing to the in vivo images. The discrepancy may be minimized by subtracting an estimate of this contribution.     

肺癌的MR全身DWI与PET成像的对照研究

目的：探讨MR DWI及PET成像在肺癌诊断及鉴别诊断中的应用价值。方法：26例临床高度怀疑为肺癌且接受了PET检查的患者行MR DWI检查,通过三维图像重组及黑白翻转技术,得到＂类PET＂图像,观察病变的形态、大小和分布,并与PET影像进行比较,在工作站上测量肺部病变的ADC值及SUV值,进行相关性分析。最终的诊断结果依据影像学检查、病理诊断和随访复查共同确定,其中肺癌19例,肺部炎性假瘤1例,慢性炎症4例,淋巴结反应性增生2例。结果：以病理结果为金标准,PET检出肺癌的敏感度为100%,特异度为57.1%;MR DWI的敏感度为94.7%,特异度为71.2%。肺癌与炎性病变的ADC值及SUV值差异均有统计学意义（P〈0.01）,肺癌病灶的ADC值与SUV值没有明显线性相关关系（r=-0.293,P〉0.05）。结论：MR DWI及PET成像对肺癌的诊断有较高的敏感度及特异度,两种方法互为补充,可为肺癌的诊断及鉴别诊断提供更多的信息。     

发作间期SPECT对难治性颞叶癫痫的诊断价值

目的:探讨难治性颞叶癫痫(TLE)单光子发射计算机断层(SPECT)的影像特征及定位诊断价值.方法:选择35例经临床手术证实的难治性TLE,术前均行发作间期SPECT脑血流灌注显像和常规MRI扫描.以临床定位结果做对照,观察难治性TLE的SPECT影像改变,分析发作间期脑血流灌注显像定位诊断颞叶致痫灶的临床应用价值.结果:难治性颞叶癫痫SPECT的影像特征为致痫灶侧前颞叶内侧和/或外侧皮质的血流灌注减低,对侧前颞叶的内侧皮质可出现轻度的灌注减低.常合并与患侧同侧的一处或以上脑区的灌注减低.SPECT致痫灶定位诊断的阳性率达77.14％00(27/35),尤其能检出52.94％ (9/17) MRI阴性TLE的致痫灶.结论:发作间期SPECT脑血流灌注显像能丰富难治性TLE的定位诊断信息,提高定位MRI阴性TLE患者致痫灶的比例.