SPECT-CT的临床应用进展

SPECT-CT能有效显示解剖与功能关系,更好帮助疾病诊断和病理生理的理解。SPECT通过与同机定位CT图像融合可有效地对病变进行定性定位,提高了传统SPECT定位、定性的准确性。SPECT-CT在肿瘤与非肿瘤疾病诊断、治疗方面发挥了重要的作用。     

甲状腺肿瘤SPECT-CT融合显像的应用近况

甲状腺肿瘤SPECT-CT融合显像将解剖成像与功能成像的优势相结合,克服了以往SPECT、CT单一成像的各自缺陷,可同时提供病变的解剖结构与功能代谢信息,能在术前对甲状腺肿瘤进行精确定位,在鉴别肿瘤良恶性、探测复发或转移、评价治疗效果等方面具有独特优势。与PET-CT相比,其价格低廉,具有较高的临床应用价值。     

SPECT-CT在临床肿瘤学中的应用

鉴于PET-CT应用的巨大成功,人们对与其类似的SPECT-CT的兴趣越来越大。SPECT-CT实现了SPECT功能信息与CT解剖信息的同机融合,大大提高了诊断的敏感性和特异性。该文综述SPECT-CT的一些特点及目前在内分泌肿瘤、前哨淋巴结、肿瘤骨转移、淋巴瘤等方面的应用价值。     

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。     

内分泌肿瘤SPECT/CT临床应用进展

内分泌肿瘤的诊治依靠多种常规影像学技术，CT、MRI、US的优势在于分辨力高，解剖结构显示清楚，而核医学侧重于功能成像，图像分辨力低，其影像模式各有优缺点。近年来整合了功能信息影像和解剖结构影像的SPECT／CT逐步应用于临床，为临床提供更加全面和准确的资料。     

内分泌肿瘤SPECT/CT临床应用进展

内分泌肿瘤的诊治依靠多种常规影像学技术,CT、MRI、US的优势在于分辨力高,解剖结构显示清楚,而核医学侧重于功能成像,图像分辨力低,其影像模式各有优缺点。近年来整合了功能信息影像和解剖结构影像的SPECT/CT逐步应用于临床,为临床提供更加全面和准确的资料。     

99Tcm-MIBI显像在甲状旁腺功能亢进症中的应用及进展

99Tcm-MIBI SPECT对甲状旁腺功能亢进症的术前诊断有较高的灵敏度,联合超声或CT能提高诊断和定位的准确率,尤其是对异位的甲状旁腺腺瘤。随着微创甲状旁腺切除术的发展,99Tcm-MIBI SPECT/CT在术前准确定位上的价值日益凸显。甲状旁腺病灶的大小、生化指标等因素会影响99Tcm-MIBI显像的灵敏度和定位准确率。对于部分难以准确诊断和定位的甲状旁腺功能亢进症患者,11C-蛋氨酸PET/CT、四维CT、术中放射导航等是目前的研究热点和发展方向。     

治疗活度131I SPECT/CT显像对分化型甲状腺癌患者诊断增益价值的研究

目的 探讨治疗活度131I SPECT/CT显像对分化型甲状腺癌（DTC）患者的诊断增益价值和其对临床诊疗决策的影响。 方法 回顾性分析2017年1月至2020年5月于四川大学华西医院接受131I治疗的404例DTC患者的临床资料,其中男性89例、女性315例,年龄21~69（46.3 ± 5.9）岁。所有患者均首次行131I治疗,剂量为1.11~9.25 GBq,治疗后第5天行全身前、后位131I平面显像,同时对其探测到的摄碘灶加做SPECT/CT显像,单独依据131I平面显像和SPECT/CT显像将摄碘灶定性为残甲、颈部淋巴结转移、远处转移和不确定性病灶。依据CT的解剖定位信息,计算SPECT/CT显像对131I平面显像显示的摄碘灶的原始诊断的修正比例,从而评估SPECT/CT显像对DTC患者临床诊疗决策的影响。131I平面显像与SPECT/CT显像之间的分布差异采用McNemar和McNemar-Bowker检验进行评估。 结果 404例DTC患者的131I平面显像共检测出927个摄碘灶。SPECT/CT显像对131I平面显像显示的927个摄碘灶中的179个摄碘灶具有诊断增益价值,准确解释了131I平面显像不能定性的118个摄碘灶。SPECT/CT显像对11.9%（48/404）的DTC患者具有诊断增益价值,1.7%（7/404）患者的诊疗决策发生了改变。131I平面显像与SPECT/CT显像结果在摄碘灶定性诊断中的差异有统计学意义（χ2=101.69,P<0.001）,SPECT/CT显像对颈部淋巴结转移灶的显示明显优于131I平面显像（McNemar检验,P<0.05）。 结论 治疗活度131I SPECT/CT显像对DTC患者具有诊断增益价值,并对其临床诊疗决策具有积极意义。      

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。     

碲锌镉心脏专用SPECT的临床应用进展

心肌灌注显像在已知或可疑冠状动脉疾病患者的诊疗过程中发挥着重要作用，应用碲锌镉探测器的心脏专用SPECT的分辨率和灵敏度均得到提高，达到了降低显像剂剂量、缩短采集时间、改善图像质量和扩展临床应用范围等目的。笔者对碲锌镉心脏专用SPECT的临床应用进展进行综述。     

The role of hybrid SPECT-CT in oncology: current and emerging clinical applications

Single photon emission computed tomography - computed tomography (SPECT-CT) is an emerging dual-modality imaging technique with many established and potential clinical applications in the field of oncology. To date, there has been a considerable emphasis on the benefits of integrated positron emission tomography - computed tomography (PET-CT) in oncology, but relatively little focus on the clinical utility of SPECT-CT. As with PET-CT, accurate co-registration of anatomical and functional data from a combined SPECT-CT camera often provides complementary diagnostic information. Both sensitivity (superior disease localization) and specificity (exclusion of false-positives due to physiological tracer uptake) are improved, and the functional significance of indeterminate lesions detected on cross-sectional imaging can be defined. This article will review the scope of hybrid SPECT-CT in oncology and illustrate both current and emerging clinical applications.     

SPECT-CT: applications in musculoskeletal radiology

This article reviews the technique, basic science principles and applications of integrated single photon emission CT (SPECT)-CT in musculoskeletal radiology. A review of the current evidence on the topic was undertaken, and selected clinical cases from the authors'' institution have been used for illustration. SPECT-CT is a technology with emerging applications that offers technical advantages to image fusion of separately acquired SPECT and CT studies. The prevailing evidence indicates that there may be benefit in adding SPECT-CT to conventional imaging algorithms during the evaluation of some malignant and benign musculoskeletal conditions. SPECT-CT can improve both sensitivity and specificity by reducing equivocal interpretation in comparison to planar scintigraphy or SPECT alone. The evidence base for SPECT-CT in musculoskeletal radiology is still evolving. There is a lack of evidence comparing SPECT-CT with MRI in many key indications, and further research is required in these areas.A wide range of pathological conditions may affect the musculoskeletal system, including infection, trauma and malignant disease. Advances in MRI, multidetector CT (MDCT) and high-frequency ultrasound have provided considerable improvements in imaging musculoskeletal disease over the past decade. There are, however, limitations associated with each of these techniques. MRI image acquisition remains relatively time consuming and, particularly in musculoskeletal radiology, image quality can be degraded significantly by metal artefact from internal fixation and prostheses. MDCT offers exquisite characterisation of bone and can rapidly generate high-quality three-dimensional reconstructions; however, the contrast resolution for soft tissues is limited and the modality can also suffer metal-related artefact, although like MRI, imaging parameters can be adjusted to reduce this artefact. High-frequency ultrasound, although operator dependent, provides excellent spatial and contrast resolution for superficial structures but is suboptimal for deeper structures and is unable to penetrate cortical bone.Bone scintigraphy remains an important and highly sensitive tool to the musculoskeletal radiologist but this is frequently criticized for its lack of specificity. Radionuclide imaging, however, may be the only modality to demonstrate pathology before it becomes evident on anatomical imaging. Developments in gamma camera technology now allow high-resolution imaging with shortened scan times, and single photon emission CT (SPECT) imaging has become commonplace in the UK. SPECT is able to increase sensitivity further and improves lesion localisation, but the paucity of anatomical markers on radionuclide imaging remains a constant challenge. Thus, the importance of correlating anatomical and functional imaging has become increasingly recognised [1].Use of a combined SPECT/CT system allows for sequential acquisition of both anatomical and functional information with a high degree of image fusion accuracy.In this article, we briefly review the technique, basic science principles and technical challenges of SPECT-CT, and discuss the applications of this hybrid modality in musculoskeletal radiology.     

Less commonly used and emerging clinical applications of SPECT-CT in benign and malignant disease

The emergence of hybrid imaging, combining anatomical computed tomography (CT) and functional single-photon emission computed tomography (SPECT), has greatly expanded the armoury available to image disease. Integrated SPECT-CT is a dual-modality technique, which improves the sensitivity and specificity of existing radionuclide studies and enables characterization of equivocal findings detected by conventional imaging. There is a wide range of established and emerging clinical applications for SPECT-CT, which were reviewed in detail at a symposium organized by the British Institute of Radiology in March 2012. A series of articles were commissioned as an adjunct to the symposium and to raise awareness of the clinical utility of this technique. The focus of this article is on less commonly used and emerging clinical applications of hybrid SPECT-CT in a spectrum of benign and malignant conditions. The article will illustrate the incremental value of the technique in a variety of clinical applications.     

Infection scintigraphy: added value of single-photon emission computed tomography/computed tomography fusion compared with traditional analysis

PURPOSE: Positron emission tomography (PET)/computed tomography (CT) imaging is a powerful dual-modality integrating physiology and anatomy. Analogously, fusing separate single-photon emission computed tomography (SPECT) and CT images can overcome interpretive challenges in characterizing and localizing abnormalities. This study explores the value of SPECT/CT image fusion compared with traditional "side-by-side" SPECT-CT image review for infectious /inflammatory processes. METHODS AND MATERIALS: We identified 17 abnormal infection/inflammation SPECT scans in 16 patients (11 indium 111 WBC and 6 gallium citrate Ga 67) with a contemporary CT scan. The SPECT and CT images were uploaded onto "side-by-side" workstations, one with fusion software. Two nuclear radiologists reviewed "side-by-side" SPECT and CT images and fused SPECT/CT images. They scored 2 parameters (anatomical localization and diagnostic confidence) using a 4-point scale (1 "not helpful" to 4 "very helpful"). Score differences more than 1 indicated "added value" and less than 0, "no added value". RESULTS: Compared with "side-by-side" SPECT-CT, fused SPECT/CT images yielded "added value" for anatomical localization in 65%, diagnostic confidence in 71%, and altered interpretations in 47% of cases. Greater confidence was achieved in 75% of cases with altered interpretations and 55% of unaltered cases. CONCLUSIONS: The SPECT/CT image fusion outperformed "side-by-side" SPECT/CT review for anatomical localization and diagnostic confidence of infectious/inflammatory abnormalities. Therefore, SPECT/CT fusion potentially influences clinical decisions and treatment options.     

Preoperative 99mTc-sestamibi scintigraphy in patients with primary hyperparathyroidism and concomitant nodular goiter: comparison of SPECT-CT, SPECT, and planar imaging

BACKGROUND: Investigations using a hybrid single photon emission computed tomography/computed tomography (SPECT-CT) scanning technique have been carried out in limited studies and have shown mixed results. However, the assessment of this technique for the detection of parathyroid adenoma in patients with a nodular goiter was performed in only one study with a small sample size. The aim of this prospective study was to assess the role of Tc-sestamibi parathyroid SPECT-CT scans for localization of parathyroid adenomas with a concomitant nodular goiter using Tc-methoxyisobutyl isonitrile (MIBI) scintigraphy and to compare it with SPECT and planar imaging. METHODS: This study was conducted on 48 patients with primary hyperparathyroidism and nodular goiter, who were candidates for parathyroid surgery and had been referred for parathyroid scintigraphy. The patients underwent an early set of planar Tc-MIBI scanning procedures first, followed by SPECT and CT scannings, and finally a delayed set of planar Tc-MIBI scannings. Sensitivity, specificity, negative and positive predictive values, and accuracy were determined on a per-parathyroid-gland basis for each scanning method, as defined by histology and follow-up. RESULTS: The surgery was successful in 48 out of 50 patients with primary hyperparathyroidism concomitant with thyroid nodularity, and data were completed for 80 sites in 48 patients. The accuracy of SPECT-CT in correctly identifying a parathyroid adenoma was 85.00, versus 75.00% for SPECT (P=0.01, significant). The sensitivity and specificity for SPECT-CT were 77.55 and 96.77%, respectively, versus 67.34 and 87.09%, respectively, for SPECT (P=0.12 and 0.12, not significant). There were nine sites that showed better localization on SPECT-CT scans relative to SPECT images, of which five sites were located in the ectopic regions. CONCLUSION: The results of our study indicate that SPECT-CT is more accurate than sestamibi planar imaging and SPECT for the preoperative identification of parathyroid lesions in patients with primary hyperparathyroidism concomitant with thyroid nodularity. Also, we would recommend the use of SPECT-CT for a workup of all patients with ectopic glands who are scheduled for minimally invasive parathyroid surgery.     

Initial application of respiratory-gated 201Tl SPECT in pulmonary malignant tumours

AIM: Respiratory-gated thallium-201 chloride (201Tl) single photon emission computed tomography (SPECT) was used in preliminary investigations to reduce the adverse respiratory motion effects observed on standard ungated SPECT images and to obtain reliable fusion images with computed tomography (CT) in patients with malignant lung tumours. METHODS: Fifteen patients with primary lung cancer (n=10) or metastatic lung tumours (n=5) underwent gated SPECT 20 min after intravenous injection of 148 MBq 201Tl, using triple-headed SPECT and laser light respiratory tracking units. Projection data were acquired by a step and shoot mode, with 20 stops over 120 degrees for each detector and a preset time of 30 s for each 6 degrees stop. Gated end-inspiratory and ungated images were obtained from 1/8 data centred at peak inspiration for each regular respiratory cycle and for the full respiratory cycle data, respectively. The degree and size of tumour 201Tl uptake were compared between these images by regions of interest (ROI) analysis. Gated SPECT images were registered with rest inspiratory CT images using an automated three-dimensional (3D) image registration tool. Registration mismatch was assessed by measuring the 3D distance of the centroid of 14 201Tl-avid peripheral tumours. Attenuation correction of gated SPECT images was performed using CT attenuation values of these fusion images. RESULTS: Gated SPECT images improved image clarity and contrast of tumour 201Tl uptakes compared with ungated images, regardless of the decreased count density due to the use of gated images. The lesion-to-normal (L/N) lung count ratios and ROI size in 18 well-circumscribed 201Tl-avid tumours were significantly higher and smaller on gated images (both P<0.0001). Gated images showed positive 201Tl uptakes in two small peripheral tumours, although negative on ungated images, and demarcated 201Tl-avid tumours from adjacent 201Tl-avid lymph node or surrounding focal 201Tl uptakes caused by other pathology, although these were not clearly demarcated on ungated images. On fusion images, gated images yielded a significantly better SPECT-CT matching compared with ungated images (P<0.0001). Fusion images accurately localized 201Tl uptakes of tumour/lymph node and other focal pathological/physiological conditions. Attenuation-corrected gated SPECT images further facilitated the detection of 201Tl uptake in small or deeply located lesions, with significantly increased L/N ratios. CONCLUSION: Gated SPECT images facilitate the detection of tumour 201Tl uptake and provide reliable SPECT-CT fusion images, which contribute to accurate interpretation and attenuation correction of Tl SPECT images.     

Clinical utility of hybrid SPECT-CT in endocrine neoplasia

OBJECTIVE: Imaging of endocrine neoplasms often involves a combination of anatomic and functional techniques including sonography, CT, MRI, and scintigraphy. Recent technologic advances have enabled hybrid imaging using SPECT-CT, which combines anatomic and functional techniques to allow accurate localization of tumors, increased detection of recurrent and metastatic disease, and exclusion of physiologic uptake. CONCLUSION: SPECT-CT provides improved specificity and diagnostic confidence helping to guide conventional management and assess suitability for targeted radionuclide therapy.