IQ·SPECT、碲锌镉探测器SPECT和传统SPECT在心肌灌注显像中的应用分析

IQ·SPECT与碲锌镉（CZT）探测器SPECT是心肌灌注显像新技术,与传统SPECT相比,具有灵敏度和空间分辨率高、采集时间短、注射显像剂剂量少及辐射剂量低等优点。与传统SPECT不同（低能高分辨率平行孔准直器）,IQ·SPECT使用SMART-ROOM准直器及心脏为焦点的采集模式,提高了灵敏度;CZT探测器SPECT的探测器为半导体,取代了传统NaI晶体探测器,提高了能量分辨率、空间分辨率、灵敏度及信噪比等,并可定量分析心肌血流储备。笔者主要对三者的成像原理、性能参数及临床应用进行综述。     

SPECT定量心肌血流及冠状动脉血流储备的研究进展

应用SPECT、单光子显像剂及示踪动力学技术能方便地定量心肌血流量（MBF）及冠状动脉血流储备（CFR）。特别是碲锌镉心脏专用SPECT的使用,能更快速、准确地获得定量结果。MBF、CFR的获得对冠心病诊断准确性的提高、患者的再分层及进一步预后评估具有重要意义,并且为冠状动脉微血管疾病的诊断提供客观依据。但是使用SPECT定量MBF及CFR仍存在一些不足之处尚待解决。笔者旨在对SPECT定量MBF及CFR的不同方法、初步应用结果及临床意义作一综述。     

心脏专用碲化镉锌相机的相关临床应用新进展

在评估缺血性心脏病的无创性方法中,SPECT心肌灌注显像（MPI）是大家公认的显像方法,但MPI受到一些因素的影响,如组织不均一性导致的衰减、扫描时间长、辐射等。近年来出现的心脏专用碲化镉锌（CZT）相机越来越受到人们的广泛关注,该设备有先进的CZT探测器、采集方法及重建算法。心脏专用CZT相机的计数率、空间分辨率和能量分辨率较传统SPECT显著提高。该文就心脏专用CZT相机的相关临床应用进展进行综述。     

利用CZT SPECT进行心脏 99Tc m-MIBI/ 123I-MIBG双核素显像的可行性研究

目的:探讨利用碲-锌-镉(CZT)SPECT行 99Tc m-甲氧基异丁基异腈(MIBI)/ 123I-间碘苄胍(MIBG)双核素显像的可行性。 方法:利用A、B、C 3种心脏模型分别模拟正常心肌模型、 99Tc m/ 123I匹配心肌、...     

移动校正对CZT SPECT心肌血流定量显像影响的初步研究

目的:探讨移动校正(MC)对碲锌镉SPECT(CZT SPECT)心肌血流(MBF)和心肌血流储备(MFR)计算值的影响。方法:回顾性收集2019年6月至2019年8月于泰达国际心血管病医院行动态CZT SPECT心肌灌注显像(MPI)的可疑或确诊冠状动脉粥样硬化性心脏病(简称冠心病)患者28例[男10例,女18例,年...     

影像融合技术在冠心病中的临床应用进展

冠心病的诊断越来越倚重于多种影像学手段的联合。解剖与功能的融合影像实现了便捷的“一站式”检查，完善了现有的影像学诊察流程。影像融合技术如SPECT／冠状动脉造影、SPECT／CT，尤其是PET／CT的飞速发展，在冠心病的诊断、危险度分层、治疗方案的制定及预后评估等方面具有明显优于单一影像学检查的医学价值，更加完善的影像学资料及定量分析数据为临床提供了更多有用的信息。     

心脏CT和MRI如何选择

近年来CTA、CMR临床应用日趋广泛，但对其应用价值的认识及检查适应症的把握仍然有待提高。本文通过对这两种方法的横向比较以及纵向应用进行了全方位的解读。简言之，现阶段CTA 的重要临床价值主要体现在基于胸痛三联征的判断，包括冠状动脉、肺动脉和主动脉疾病等。CMR则更多的用于对心脏结构、功能和组织特性的评估，因此在重症或复杂疾病的诊断和鉴别诊断，以及在疾病的预后判断和危险分层中发挥重要作用。在临床实际应用中应该重视两种方法的优势互补。     

99Tcm-MDP SPECT/CT骨显像诊断恶性肿瘤骨转移的价值

目的探讨^99Tc^m-亚甲基二膦酸盐（MDP）SPECT／CT骨显像诊断恶性肿瘤骨转移的临床价值。方法73例恶性肿瘤或不明原因骨痛患者行^99Tc^m-MDP SPECT／CT全身骨平面和局部显像。获得全身骨平面、SPECT断层和CT图像及SPECT与CT融合图像后，结合病史、临床表现进行回顾性分析。结果SPECT／CT骨显像可提供精确的解剖定位，发现脊柱（31处）、肋骨（11处）、胸骨（4处）、锁骨（3处）、肩胛骨（1处）、骶骨（1处）、坐骨（3处）、骶髂关节（1处）和骨外（20处）有异常放射性浓聚灶。骨骼病变的性质与病灶部位有关，如病变累及椎体和（或）椎弓根，常提示肿瘤骨转移；累及椎小关节或椎体，呈“唇样”放射性浓聚，可考虑为良性病变。若平面显像呈“热区”，CT图像表现正常者，可考虑肿瘤骨转移。结论SPECT／CT骨显像诊断骨转移灶有较高临床价值。     

SPECT/CT骨显像对SAPHO综合征的诊断价值

目的探讨SPECT/CT骨显像在滑膜炎、痤疮、脓疱病、骨肥厚、骨髓炎（SAPHO）综合征诊断中的临床价值。方法回顾性分析临床怀疑SAPHO综合征的11例患者的临床资料及SPECT/CT骨显像结果,所有患者均行99Tcm-MDP全身骨显像+局部断层显像及同机或异机CT扫描,获得SPECT全身骨显像和局部SPECT骨显像、CT显像、SPECT/CT融合显像图像。分析比较SPECT骨显像和SPECT/CT融合显像对SAPHO综合征诊断的准确率、灵敏度和特异度,组间准确率的比较采用χ2检验。结果11例临床怀疑SAPHO综合征患者中,9例经穿刺组织病理或随访病情最终转归而确诊,另外2例为转移瘤。其中,SPECT诊断6例,共发现41个病灶出现放射性浓聚;SPECT/CT诊断9例,共发现44个病灶。SPECT骨显像的灵敏度、特异度和准确率分别为66.7%（6/9）、50.0%（1/2）和63.6%（7/11）;SPECT/CT融合显像的灵敏度、特异度和准确率分别为100%（9/9）、50.0%（1/2）和90.9%（10/11）,SPECT/CT融合显像对SAPHO综合症诊断的准确率明显高于单纯的SPECT显像,且差异具有统计学意义（χ2=11.82,P < 0.05）。结论SPECT/CT的联合应用提高了对病灶解剖定位的准确率及骨显像特异度,可用于SAPHO综合征患者的病灶精准定位、早期诊断与鉴别诊断、更多隐匿病灶检出以及病灶代谢活性评价等,对SAPHO综合征的诊断有较高的临床价值。     

用运动负荷99Tcm-MIBI SPECT心肌显像预测急性心肌梗死预后

目的：探讨运动负荷99Tcm-甲氧基异丁基异腈（MIBI）SPECT心肌断层显像判断急性心肌梗死（AMI）患者预后的价值。方法：对101例AMI患者出院前行运动负荷99Tcm-MIBI SPECT检查，随访心脏良性与不良事件的发生，分析心脏事件发生的相关因素及评估对心脏事件的预测价值。结果：多因素相关分析表明，AMI后心脏不良事件的独立预测因素是既往有心肌梗死病史，低运动积分和左室射血分数（LVEF）＜40％，。结论：AMI患者出院前行99Tcm-MIBI SPECT检查或获取运动能力，左室功能和心肌缺血状况等资料，从而鉴别高危患者，评估不良预后，有助于对高危患者及早进行介入治疗。     

Comparison of biventricular ejection fractions using cadmium-zinc-telluride SPECT and planar equilibrium radionuclide angiography

Background

We compared biventricular ejection fractions (EFs) from gated blood-pool single-photon emission computed tomography (SPECT) using a cadmium-zinc-telluride camera (CZT-SPECT) with planar equilibrium radionuclide angiography (ERNA) using a NaI gamma camera (NaI-planar). We also evaluated whether imaging time can be reduced without compromising image quality using the CZT camera.

Methods

Forty-eight patients underwent NaI-planar and CZT-SPECT on the same day. CZT-SPECT datasets were re-projected at an LAO orientation similar to ERNA acquisition, forming CZT-repro planar datasets. The resulting biventricular volumetric measurements and EFs were compared.

Results

LVEF calculated from CZT-SPECT and CZT-repro correlated better with NaI-planar (r = 0.93 and 0.99, respectively) than RVEF (r = 0.76 and 0.82, respectively). Excellent intra-class correlation and low bias in intra-observer comparisons were observed for the biventricular EFs derived from three datasets. A wider limit of agreement in CZT-SPECT-derived LVEFs, lower correlation and significant bias for NaI-planar, and CZT-repro-derived RVEFs was found in the inter-observer analyses. Nonetheless, the imaging time can be reduced to 4 minutes without increasing variability in EFs using the CZT camera (P = NS).

Conclusions

LVEFs calculated from CZT-SPECT and CZT-repro correlated well with NaI-planar. CZT camera may reduce imaging time while preserving image quality in the assessment of biventricular EFs.

     

201Tl定量门控心肌灌注体层显像与99mTc-红细胞门控心血池显像测定左心室射血分数的对比研究

目的 探讨201Tl定量门控心肌灌注体层显像与99mTc-红细胞门控心血池显像测量左心室射血分数(LVEF)的相关性.方法 72例受检者接受201Tl静息门控心肌灌注体层显像,用AUTOQUANT 4.21软件测量LVEF,并与24 h内的静息99mTc-红细胞平衡法门控心血池显像结果进行比较.结果 ①门控心肌灌注体层显像与门控心血池显像测量LVEF值的结果呈明显正相关(r=0.554,P=-0.000),两种方法无统计学差别(t=1.194,P＞0.05).②不同疾病组之间两种测量方法无统计学差异(P值均大于0.05).③门控心肌灌注体层显像及门控心血池显像测量的LVEF值分别为(64.68±10.77)%和(62.46±8.99)%,门控心肌灌注体层显像测量的LVEF值要比门控心血池显像高出3.55%.结论 201Tl门控心肌灌注体层显像与99mTc-红细胞门控心血池显像测量LVEF值的相关性好且结果准确,但门控心肌灌注体层显像的LVEF测量值要稍高于门控心血池显像.     

Value of automatic patient motion detection and correction in myocardial perfusion imaging using a CZT-based SPECT camera

Background

Correction of motion has become feasible on cadmium-zinc-telluride (CZT)-based SPECT cameras during myocardial perfusion imaging (MPI). Our aim was to quantify the motion and to determine the value of automatic correction using commercially available software.

Methods and Results

We retrospectively included 83 consecutive patients who underwent stress-rest MPI CZT-SPECT and invasive fractional flow reserve (FFR) measurement. Eight-minute stress acquisitions were reformatted into 1.0- and 20-second bins to detect respiratory motion (RM) and patient motion (PM), respectively. RM and PM were quantified and scans were automatically corrected. Total perfusion deficit (TPD) and SPECT interpretation—normal, equivocal, or abnormal—were compared between the noncorrected and corrected scans. Scans with a changed SPECT interpretation were compared with FFR, the reference standard. Average RM was 2.5 ± 0.4 mm and maximal PM was 4.5 ± 1.3 mm. RM correction influenced the diagnostic outcomes in two patients based on TPD changes ≥7% and in nine patients based on changed visual interpretation. In only four of these patients, the changed SPECT interpretation corresponded with FFR measurements. Correction for PM did not influence the diagnostic outcomes.

Conclusion

Respiratory motion and patient motion were small. Motion correction did not appear to improve the diagnostic outcome and, hence, the added value seems limited in MPI using CZT-based SPECT cameras.

     

Brain perfusion imaging in asymptomatic patients receiving cyclosporin.

BACKGROUND AND PURPOSE: Cyclosporin has neurotoxic effects in a significant number of transplant patients that are associated with characteristic findings on MR images. Focal abnormalities in cerebral perfusion have been implicated in the pathophysiology of cyclosporin neurotoxicity. In the clinically asymptomatic patient, however, it is not known whether any imaging evidence of cyclosporin's effect on the brain is demonstrable. Our hypothesis was that conventional MR imaging, perfusion MR imaging, and single-photon emission CT (SPECT) could enable detection of subclinical lesions in asymptomatic patients. The ability to detect such lesions might aid in the identification of persons most at risk for clinical neurotoxicity. METHODS: Ten posttransplant patients being treated with cyclosporin were recruited prospectively. Imaging studies were performed within 3 weeks of transplantation. Patients were examined with MR imaging, using standard spin-echo and dynamic contrast-enhanced perfusion techniques, and SPECT scanning. Postprocessing of MR perfusion data was performed to obtain pixel-by-pixel maps of regional cerebral blood volume, peak height, and time-to-peak parameters. RESULTS: The mean age of the patients was 45 +/- 11 years. At the time of imaging, three patients had minor neurologic manifestations commonly associated with cyclosporin (ie, mild tremor, headache), but no patient had clinical neurotoxicity. Findings on conventional MR images, MR perfusion maps, and SPECT perfusion scans were normal in all patients. CONCLUSION: Conventional MR imaging, dynamic perfusion MR imaging, and SPECT do not depict any lesions in asymptomatic patients on cyclosporin. Therefore, it may not be possible for imaging methods to aid in the identification of patients at risk for neurotoxicity. Our findings support previously published conclusions that the lesions visible in patients with clinical neurotoxicity are due to cyclosporin effects and not to preexisting coincidental abnormalities.     

Single photon emission computed tomography (SPECT). Part II: Clinical applications

The clinical applications of SPECT are just beginning to be defined since complete systems have only recently become available. SPECT studies are more difficult to perform than planar imaging studies, and close attention to quality control is important to obtain optimal studies. SPECT has higher lesion contrast and is able to detect smaller lesions than planar imaging in Tc-99m sulfur colloid liver studies. Preliminary results of SPECT T1-201 studies are encouraging, but further work comparing SPECT and planar imaging of T1-201 is needed. SPECT does give more information than planar imaging in certain bone imaging cases such as suspected avascular necrosis of the hip. Although interesting results have been published using SPECT in brain and lung perfusion studies, the clinical utility of this work has not been determined. The development of certain radiopharmaceuticals would enhance the future of SPECT. Technetium-99m labeled brain and myocardial perfusion agents would be ideally suited for SPECT studies. The ability to quantitate lesion volume (eg, in liver metastases) has not been studied and could be useful in following patents on chemotherapy. SPECT could give additional information if monoclonal antibodies labeled with I-123 or Tc-99m can be demonstrated to have appropriate sensitivity. The advantages of SPECT over planar imaging will be greater as new agents are developed.     

Preoperative risk stratification using stress myocardial perfusion scintigraphy with electrocardiographic gating.

This study was designed to assess the prognostic value of stress myocardial perfusion SPECT with electrocardiographic (ECG) gating in patients undergoing noncardiac surgical treatment. METHODS: The study included 481 consecutive patients who underwent noncardiac surgery and had been referred for preoperative myocardial perfusion scintigraphy. Myocardial scintigraphy used (99m)Tc-labeled perfusion agents and dipyridamole stress with ECG gating, permitting qualitative and quantitative analyses of both myocardial perfusion and cardiac function. Reconstructed perfusion images were analyzed qualitatively and semiquantitatively. The Quantitative Gated SPECT (QGS) program was used for gated SPECT analysis to calculate global left ventricular ejection fraction and estimate regional wall motion. We assessed the relationships between perioperative cardiac events and various predictors, including clinical risk factors, radionuclide perfusion, and functional variables. RESULTS: Univariate analysis indicated that age (P < 0.001), diabetes mellitus (P < 0.01), history of heart failure (P < 0.05) or perfusion imaging (P < 0.0001), and QGS analysis (P < 0.0001) yielded significant risk stratification. According to multivariate analysis, age, diabetes mellitus, perfusion imaging, and QGS analysis were independent predictors of perioperative cardiac events. The event rate was correlated with quantitative scintigraphic indices of perfusion images (rest perfusion and ischemic scores) and QGS analysis (global ejection fraction and the number of hypokinetic segments). Although QGS functional data offered no significant incremental prognostic value in patients with abnormal perfusion, it classified patients with normal perfusion into 2 risk groups (P < 0.0001). A combination of clinical risk factors, scintigraphic perfusion results, and functional data allowed further detailed risk stratification. CONCLUSION: Stress myocardial perfusion SPECT with ECG gating has an incremental prognostic value over conventional nongated stress perfusion imaging in predicting perioperative cardiac events.     

The clinical utility of 99<Superscript>m</Superscript>Tc-HMPAO SPECT in Fahr’s disease

Fahr's disease is a rare neurodegenerative syndrome, characterized by massive symmetrical intracerebral calcifications of the basal ganglia, dentate nuclei of the cerebellum, and the adjacent parenchyma. Computerized tomography (CT) is considerably more sensitive to detect these intracranial calcifications than other imaging modalities. The clinical, CT scan, and 99(m)Tc-D,L-hexamethylpropylene amine oxime (99(m)Tc-HMPAO) brain perfusion single-photon emission computerized tomography (SPECT) findings in a 42-year-old woman with Fahr's disease are reported, and the clinical utility of 99(m)Tc-HMPAO SPECT findings in Fahr's disease is discussed in this article. In conclusion, 99(m)Tc-HMPAO brain perfusion SPECT seems to be useful in the clinical approach to Fahr's disease, and may provide more specific and clinically relevant information when compared with anatomical imaging.     

The expanding role of left ventricular functional assessment using gated myocardial perfusion SPECT: the supporting actor is stealing the scene

Background Gating of single-photon emission computed tomography (SPECT) has significantly improved the reliability and diagnostic accuracy of myocardial perfusion imaging. The functional parameters derived from this technique, mainly left ventricular volumes and ejection fraction, have been demonstrated to be accurate and reproducible. They are able to increase the detection of severe and extensive coronary artery disease and show a significant incremental prognostic power over perfusion abnormalities. Therefore, the importance given to gated SPECT functional data has progressively grown. Discussion This circumstance has further expanded the indications for myocardial perfusion imaging and strengthened its position among the different imaging modalities. Moreover, several studies show that the evaluation of ventricular function may have a leading part in justifying the execution of perfusion scintigraphy in various clinical conditions. Aim Aim of this review is to describe this evolution of gated SPECT functional assessment from a supporting rank with respect to perfusion, to a main actor position in the field of cardiac imaging.     

Advances in quantitative perfusion SPECT imaging

Quantitative software for myocardial perfusion single photon emission computed tomography (SPECT) has advanced significantly over the last 25 years. The strength and availability of quantitative tools for perfusion SPECT have in many ways provided a competitive advantage to nuclear cardiology compared with other higher-resolution noninvasive imaging modalities for the detection of coronary artery disease. The purpose of this report is to review the advances in quantitative diagnostic software for cardiac SPECT over the past 25 years. The time period ending with the 1980s ("the past") saw the origins of nuclear cardiology with the development of planar thallium 201 imaging and perfusion SPECT imaging without electrocardiographic gating. The period from 1990 to the present saw the development of gated SPECT imaging providing both perfusion and functional information and attenuation correction SPECT with improved perfusion information. The report concludes with a look into the future, where hybrid multimodality imaging systems may provide a comprehensive noninvasive evaluation with previously unmatched accuracy in a single imaging session.     

Examination of three-detector high-speed-rotation SPECT acquisition under breathhold in body: clinical application of 99mTc-MAA

In traditional pulmonary perfusion single photon emission computed tomography (SPECT), respiratory lung motion and cyclically varying changes in lung volume during image acquisition inherently degrade the image sharpness of ill-defined perfusion defects. However, because of the lack of an adequate fast imaging technique, perfusion SPECT has never been acquired under breathhold conditions, whereas breathhold images are commonly used for pulmonary magnetic resonance (MR) and computed tomographic (CT) images. Although a high-speed imaging technique combined with a multidetector SPECT system may enable SPECT images to be obtained during a short period of breathholding, image quality would be degraded owing to decreased radioactivity counts and increased statistical noise. To resolve this problem, we developed an innovative SPECT imaging technique using a triple-head SPECT system and the high-speed-detector rotation-multiplied projection (HSRMP) technique, where a single SPECT image was reconstructed from multiple respiratory dimensional breathhold projection data obtained at the same angle. HSRMP provided noiseless high-quality perfusion SPECT images by compensating for decreased radioactivity counts caused by high-speed imaging, and significantly improved image quality and perfusion defect clarity compared with traditional non-breathhold SPECT images.