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.     

冠心病患者201Tl和99Tcm-MIBI双核素心肌灌注显像

目的探讨静息201Tl/负荷99Tcm-甲氧基异丁基异腈(MIBI)双核素心肌SPECT显像在冠心病诊断中的价值.方法对36例冠心病患者行201Tl负荷-延迟再分布心肌SPECT显像;常规潘生丁药物负荷高峰时,静脉注射201Tl 111～148 MBq,15 min后进行心肌显像.对23例冠心病患者和9例正常人行静息201Tl负荷、99Tcm-MIBI双核素心肌SPECT显像,静息状态注射201Tl 111～148 MBq,注射后5 min给予潘生丁药物负荷,高峰时注射99Tcm-MIBI 925 MBq.1 h后行双核素显像.结果 36例冠心病患者201Tl负荷-延迟再分布心肌显像的阳性率为83.33%,23例冠心病患者双核素心肌显像的阳性率为100%,两组阳性率比较差异有显著性(χ2=4.267,P=0.043).9例正常受检者均为阴性.结论双核素心肌显像对冠心病的检出率较高,省时、安全并可获得高质量图像,对冠心病诊断有较高临床价值.     

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。     

双核素心肌显像预测PCI术后心功能改善的评价

目的:探讨多巴酚丁胺201Tl负荷-再分布/硝酸甘油介入99Tcm-MIBI门控心肌灌注显像预测PCI术后心功能改善的作用.方法:69例临床怀疑有冠心病拟行经皮冠状动脉介入治疗(PCI)的病人进行多巴酚丁胺201 Tl负荷-再分布显像,显像结束后行硝酸甘油介入99Tcm-MIBI门控心肌灌注显像.心肌显像后2周内69例病人全部进行了经皮冠状动脉介入治疗.PCI术前及术后3个月心脏超声测定左室射血分数(LVEF).结果:①69例病人PCI术后左心室功能较术前有改善(△LVEF=4.78±2.4,t=2.02,P值<0.05).②左心室功能降低组术后心功能提高值明显高于左心室功能正常组(△LVEF=5.3±2.0对LVEF=3.1±2.9,t=2.83,P<0.05).③可逆性灌注缺损心肌节段数>3组术后心功能提高值明显高于可逆性灌注缺损心肌节段数≤3组(△LVEF=5.8±1.6对△LVEF=4.4±1.4,t=2.45,P<0.05).结论:多巴酚丁胺201Tl负荷-再分布/硝酸甘油介入99Tcm-MIBI门控心肌灌注显像能准确检出缺血且存活心肌,对PCI术后心功能改善有很好的预测价值.     

静息门控心肌灌注显像总积分在冠心病诊断中的临床价值研究

目的探讨静息门控心肌灌注显像总积分在冠心病诊断中的临床价值。方法回顾性分析43例冠心病患者,所有患者均行门控心肌灌注显像(GMPI),应用ECTbox软件计算左室舒张末期容积(EDV)、收缩末期容积(ESV)、左室射血分数(LVEF)、每搏输出量(SV),利用半定量分析法得出静息灌注总积分SRS,与上述各指标进行相关性分析,根据SRS的结果将患者分为两组(SRS 10分组、SRS≥10分组),比较两组间左心功能参数差异(均为P 0. 05),并比较各指标在男女之间的差异,最后探讨GMPI在冠心病中的诊断价值。结果 SRS 10与SRS≥10两组间左心功能参数具有明显差异,P 0. 01; SRS及IVEF呈显著负相关,r=-0. 710,SRS与EDV、ESV呈显著正相关,相关系数分别为0. 703、0. 764,与SV呈负相关,r=-0. 415,均为P 0. 01;男性受检者EDV,ESV明显高于女性受检者,而LVEF明显低于女性,男女间差异具有显著性(P 0. 01)。结论门控心肌灌注显像SRS与左室功能呈显著负相关。静息门控心肌灌注显像在冠心病(CAD)的诊断及疗效评估有重要价值。     

双核素心肌显像检测存活心肌的对比研究

目的 对比多巴酚丁胺负荷201Tl/静息99Tcm-甲氧基异丁基异腈(MIBI)双核素同步心肌断层显像及多巴酚丁胺负荷-再分布/再注射201Tl心肌断层显像法检测存活心肌的作用.方法 对160例临床怀疑有冠心病的患者予静息状态下静脉注射740 MBq99Tcm-MIBI,休息15 min后进行多巴酚丁胺负荷试验,在达到终止指标时静脉注射111 MSq201TICI.注射后观察5-lO min,分别行早期(10 min)、延迟(3 h)99Tcm-MIBI和201Tl双核素同步心肌断层显像.对早期负荷201Tl图像发现放射性缺损,延迟再分布201Tl和静息99Tcm-MIBI图像未见放射性填充的患者再注射37 MBq201TICI,30min后行再注射心肌灌注显像.负荷枷201Tl图像示放射性缺损,静息99Tcm-MIBI、再分布201Tl及再注射201Tl图像中发现任何一种放射性填充者均为存活心肌.断层显像后2周内全部患者进行了冠状动脉造影.采用SAS 6.12软件进行x2检验.结果 (1) 160例患者冠状动脉造影均发现冠状动脉狭窄.其中单支病变76例、双支病变5l例、三支病变33例.(2)152例多巴酚丁胺负荷201Tl图像发现放射性缺损的患者中,63例201Tl再分布和静息99Tcm-MIBI图像均发现放射性填充,5例201Tl再分布发现放射性填充而静息99Tcm-MIBI图像未见放射性填充,9例静息99Tcm-MIBI图像发现放射性填充而2001Tl再分布未见放射性填允,75例201Tl再分布和静息99Tcm-MIBI图像均未发现放射性填充,负荷201Tl-延迟再分布显像(66.0%,68/103)和负荷201Tl/静息99Tcm-MIBI显像(69.9%,72/103)鉴别存活心肌的灵敏度差异无统计学意义(x2=O.36,P>0.05).(3)75例201Tl再分布和静息99Tcm-MIBI图像均未发现放射性填充患者中,再注射201Tl显像后有26例放射性填充,再注射201Tl显像较单纯201Tl再分布或静息99Tcm-MIBI显像多检测出34.7%(26/75)患者有存活心肌.(4)8例多巴酚丁胺负荷201Tl、201Tl再分布图像和静息99Tcm-MIBI图像均未发现放射性稀疏,为假阴性,其中3例为三支冠状动脉病变,1例为双支冠状动脉病变(狭窄分别为90%及60%),3例为单支冠状动脉病变(狭窄<75%2例,85%1例),1例冠状动脉闭塞后有充分的侧枝循环.结论 多巴酚丁胺负荷-再分布/再注射201Tl心肌断层显像鉴别存活心肌优于多巴酚丁胺负荷201Tl/静息99Tcm-MIBI双核素同步心肌断层显像,是一种有效、无创的鉴别存活心肌的方法.     

门控心肌灌注断层显像与超声心动图评价左室功能和左室容积的比较

门控心肌灌注断层(GSPECT)显像可同步评价左室心肌血流灌注和左室功能状况,此技术所测的左室射血分数(LVEF)、舒张末期容积(EDV)和收缩末期容积(ESV)的准确性报道尚少。因此,使用不同的显像剂和显像方案行GSPECT显像,将其测定的结果与超声心动图(ECG)进行比较。方法:109例冠心病患者(男53例,女56例)于15d内分别行GSPECT显像和ECG检查。其中42例采用201　Tl负荷-再分布显像方案,55例行一天法99Tcm-甲氧基异丁基异腈(99Tcm-MIBI)或99Tcm-tetrofosmin负荷-静息显像方案,余12例行静息201　Tl-负荷99Tcm-MIBI显像方案。每个…     

腺苷试验与运动试验201Tl心肌灌注显像对冠心病诊断价值的比较

目的比较腺苷试验与运动试验^201Tl心肌灌注显像对冠心病的诊断价值。方法将41例临床疑诊冠心病患者随机分为两组,一组进行腺苷试验^201Tl心肌灌注显像,一组进行运动试验^201Tl心肌灌注显像。两组试验对象均同期（2周内）行冠状动脉造影术。以冠状动脉狭窄≥50%作为冠心病诊断的“金标准”,比较两种负荷方法对冠心病的诊断价值。结果腺苷试验^201Tl心肌灌注显像对冠心病诊断的灵敏度、特异度、阳性预测率、阴性预测率、准确率分别为92.86%、57.14%、81.25%、80.0%、80.95%,运动试验^201Tl心肌灌注显像分别为100%、60.0%、71.43%、100%、80.0%,两种负荷方法对病变冠状动脉的检出率分别为66.67%和72.22%。结论两种负荷方法诊断冠心病的总体效能无显著差异。     

99 Tcm-MIBI SPECT心肌显像对冠状动脉介入治疗术后预后判断的价值

目的评估99Tcm-甲氧基异丁基异腈(MIBI)运动-静息SPECT心肌显像对冠状动脉介入治疗 (PCI) 后患者长期预后判断的价值.方法对接受PCI并于1992年1月～2001年12月行99Tcm-MIBI运动-静息心肌灌注显像的冠心病患者进行回顾性随访.图像分析采用20节段,4分打分法,获得运动总积分(SSS)、静息总积分(SRS)和心肌缺血分(SDS).结果根据心肌显像结果将患者分为正常组(SSS=0,153例)、固定缺损组 (SDS<3,SRS>1,100例) 和可逆性缺损组(SDS≥3,65例).急性心肌梗死(AMI)和死亡为恶性心脏事件,再次血运重建术(心肌显像后≥3个月)为良性心脏事件.318例入选患者,随访时间(38±27)个月.随访期间,51例(16.0%)患者发生心脏事件,其中1例死亡,13例AMI,9例冠状动脉搭桥术,28例2次PCI.可逆性缺损组的年恶性心脏事件发生率为3.9%,与正常组(0.2%)相比差异有显著性(χ2=7.71,P=0.005).可逆性缺损组的年良性心脏事件发生率为10.7%,与固定缺损组 (2.5%,χ2=17.69, P<0.000 1)和正常组(1.5%,χ2=33.89,P<0.000 1)相比差异均有显著性.心肌显像正常或为可逆性缺损则恶性和良性心脏事件发生率在有心绞痛和无心绞痛患者间差异无显著性(P>0.05).而心肌显像为固定性缺损区,则有心绞痛症状的良性心脏事件发生率明显高于无心绞痛者(15.9%和1.8%,χ2=6.11,P=0.013).Cox多元线性回归分析示SSS(χ2=12.70,P<0.000 1)和SDS(χ2=5.80,P<0.05)为预测恶性心脏事件的独立危险因子;而SDS(χ2=11.72,P<0.000 1)为预测良性心脏事件的独立危险因子.结论 PCI后患者,如99Tcm-MIBI心肌SPECT显像正常,则预后良好;如心肌显像呈可逆性缺损,心脏事件发生率明显增加,心脏事件的发生与有无心绞痛无明显关系;如心肌显像为固定性缺损,则有心绞痛症状患者接受再次血运重建术的可能性明显高于无心绞痛症状患者.因此,该方法对于PCI后患者的预后估测和进一步治疗方案的制定有较为重要的临床价值.     

~(18)F-FDG与~(201)Tl静息-再分布SPECT显像在识别存活心肌及预测再血管化术后心功能恢复中的价值比较

目的:比较18F-FDG和201　Tl静息-再分布的SPECT显像在预测再血管化术后左室局部功能改善中的价值。方法:对拟行再血管化手术并经超声心动检查确有局部室壁运动异常的24例冠心病患者在同一天内进行201　Tl静息-再分布及18F-FDGSPECT显像。用201　Tl静息-再分布SPECT显像的早期影像作为心肌灌注显像与18F-FDGSPECT显像比较;用极坐标靶心图对201　Tl静息-再分布显像资料进行半定量分析;采用13节段模型分析比较超声心动图与心肌断层影像。将18F-FDGSPECT显像示室壁运动异常节段中灌注影像正常或不匹配(灌注降低而18F-FDG摄…     

Stress MR imaging for evaluation of popliteal artery entrapment

The popliteal artery entrapment (PAE) syndrome has been recognized as a cause of arterial occlusion in young people. It is the result of an anomaly of the relationship between the popliteal artery and the gastrocnemius muscle. Eight young healthy volunteers (16 legs) and six patients (10 legs) with suspected PAE underwent magnetic resonance (MR) imaging. Gradient-echo images were obtained in axial planes with the leg at rest and during active plantar flexion against resistance. Imaging at rest allowed identification of PAE signs in only one leg, which had an anomalous medial course of the popliteal artery. In the other cases, only the stress technique was able to show signal loss in the popliteal artery due to muscular compression (two legs) or the presence of accessory muscle slip around the vessel (two legs), as confirmed at surgery. MR imaging is therefore a useful technique for the diagnosis of PAE because of its capability of combining information obtainable with other modalities.     

MR imaging of muscle and tender points in fibromyalgia

Fibromyalgia is a syndrome manifested by chronic, diffuse muscu-loskeletal aching and soreness, palpable muscle tender points, and other symptoms. Standardized clinical diagnostic criteria have recently been developed. Skeletal muscle has been postulated as the end organ in this disease. Biochemical, histologic, electromyographic, and conventional radiographic studies have demonstrated no definitive abnormality. This study sought to establish whether magnetic resonance (MR) imaging could demonstrate any abnormality in these patients. Eighteen patients were entered in the study, 14 of whom were able to complete their examinations. T1 -weighted, T2-weighted, gradient-echo, and STIR (short-tau inversion-recovery) sequences were performed in all patients, with selected patients examined with T1weighted, gadopentetate dimeglu-mine-enhanced sequences. The trapezius and suboccipital regions were imaged in patients who, clinically, had active fibro-myalgia. No abnormalities could be detected. The authors conclude that the conventional MR imaging used in this study was unable to depict any primary skeletal muscle abnormality in fibromyalgia.     

Uterine contractions: Possible diagnostic pitfall at MR imaging

A total of 206 nongravid patients with various gynecologic problems underwent pelvic magnetic resonance (MR) examinations that included both sagittal T2-weighted and contrast agent–enhanced T1-weighted images. MR images were retrospectively reviewed to identify changes in endometrial configuration on serial images obtained during the same MR examination. In 20 MR examinations (all in women of reproductive age), endometrial distortion due to myometrial bulging was noted on T2-weighted or contrast-enhanced T1-weighted images. It was absent on other MR images obtained at different times. Myometrial bulging exhibited low signal intensity in 18 examinations. The finding resembled adenomyosis or leiomyoma on T2-weighted or contrast-enhanced T1-weighted images. These results evidence the presence of transient myometrial bulging and transient low-intensity myometrium in the nongravid uterus. This phenomenon is thought to represent uterine contraction. Clinicians should be aware of the potential presence of transient low-signal-intensity myometrial bulging that could present diagnostic problems in the normal uterus.     

Controversies in cervical spine imaging in trauma patients

No area of emergency radiology has generated as much discussion in recent years as the subject of cervical spine imaging for trauma patients. This review will be in three parts. The first will examine the indications for cervical imaging and will focus on those factors that make patients at high risk or low risk for cervical injury. The second part will discuss the merits of radiography and computed tomography as the main screening diagnostic examination. In addition to the roles of each modality in the evaluation process, such factors as efficacy of diagnosis, time (duration) of study, and cost will be discussed. Finally, the third part will explore the methods currently employed to clear the cervical spine in comatose patients.Presented at the Annual Meeting of the American Society of Emergency Radiology, Las Vegas, Nevada, 22–25 October, 2003     

Brodie Abscess: MR imaging appearance in 10 patients

The magnetic resonance (MR) imaging features of Brodie abscess have not yet been fully evaluated. Ten patients with Brodie abscess, eight of long bone and two of vertebra, were studied with MR imaging. Long bone abscess had a characteristic “target” appearance with four layers: (a) a center with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR (short-inversion-time inversion recovery) images, (b) an inner ring isointense to muscle on T1-weighted images and with high signal intensity on T2-weighted and STIR images, (c) an outer ring hypoin-tense on all images, and (d) a peripheral halo hypointense on T1-weighted images. In six of eight cases, a soft-tissue mass was found. The two vertebral abscesses had a less specific appearance, with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR images. Only the peripheral halo was clearly identified in both cases.     

Right-side aortic arch with aneurysm of aberrant left subclavian artery: MR imaging appearance.

Reports of aneurysms of the subclavian artery in both normal and anomalous aortic arches have been rare. The authors describe a patient with a right-side aortic arch and an aneurysm of the aberrant left subclavian artery, which, to the authors' knowledge, is a previously unreported association. At presentation, the aneurysm appeared as a calcified left superior mediastinal mass. Magnetic resonance imaging enabled preoperative diagnosis and guided surgical planning.     

MR angiography of congenital heart disease: Value of segmented two-dimensional inflow technique and maximum-intensity-projection display

Magnetic resonance (MR) angiography of the cardiovascular system was evaluated in 41 patients with congenital heart disease by using a two-dimensional (2D) inflow technique based on a magnetization-prepared gradient-echo pulse sequence with segmented k-space data acquisition and electrocardiographic gating at 0.5 T. Inversion and saturation prepulses were used to suppress stationary tissue and enhance intravascular signal. Presaturation slabs were applied where certain vascular structures had to be suppressed. Sequence parameters were optimized by evaluating signal intensity and contrast characteristics for various flip angles and inversion and saturation delay times. The heart and intrathoracic vasculature were encompassed with 40–50 overlapping sections. Both 2D angiograms and maximum-intensity-projection images were evaluated. Combining data sets acquired in the sagittal and transverse orientations provided the most satisfactory information about the pulmonary arteries. The highest signal-to-noise ratios were obtained with a flip angle of 65° and short prepulse delay times. Two-dimensional MR angiography can provide useful diagnostic information but requires a thorough understanding of in-plane and hemodynamically induced signal intensity changes.     

Adrenal tissue characterization with 0.5-T MR imaging: Value of T2*-weighted images

The authors investigated the value of magnetic resonance (MR) imaging at 0.5 T for distinguishing adrenal adenomas from adrenal metastases. The series included 23 adrenal adenomas (18 nonhyperfunctioning, five hyperfunctioning) and 23 adrenal metastases from various organs. Adrenal tumor–liver signal intensity ratios on T1-, T2-, and T2*-weighted images were calculated for adrenal tissue characterization. Adrenal adenomas were more precisely distinguished from adrenal metastases on T2*-weighted images (21 of 23, 91%) than on T2-weighted images (15 of 23, 65%). T1-weighted images were not useful for this distinction. In conclusion, T2*-weighted images were better than routine T2-weighted images for distinguishing adrenal adenomas from adrenal metastases. It can be postulated that the total signal intensity of adrenal adenomas, which contain some fat components, decreased on T2*-weighted images because of an out-of-phase effect.     

Dynamic contrast-enhanced MR imaging assessment of vascularized free fibular grafts

Magnetic resonance (MR) imaging may be a noninvasive method for assessing perfusion of vascularized bone grafts placed for treatment of avascular necrosis. One proximal femur of seven beagles was devascularized, with insertion of a vascularized fibular graft. MR imaging at 1 week (seven dogs) and 6 weeks (five dogs) after surgery included pre- and postcontrast spin-echo sequences, unenhanced twodimensional time-of-flight (TOF) vascular imaging, and dynamic gradient-echo imaging during infusion of gadolinium. Relative signal intensity values of selected regions obtained from the dynamic gradientecho images were plotted as percent enhancement versus time. In the operated hip, MR imaging did not show enhancement in six of seven femoral heads and greater trochanters at 1 week after surgery, with similar results after 6 weeks. MR imaging of fibular grafts 6 weeks after surgery showed an initial rapid increase in enhancement and a subsequent slower increase in five of five dogs, although no enhancement was seen in six of seven dogs at 1 week. These findings contrasted with a rapid initial increase in enhancement followed by slow decline in non-operated hips. Two-dimensional TOP imaging did not show the vascular pedicle of the graft in any dog. Findings of radionuclide bone scanning performed 1 week after surgery were consistent with devascularization of the operated femur and fibular graft. However, tetracycline distribution and histologic findings confirmed the viability of five of five grafts within the devascularized femurs 6 weeks after surgery. Thus, dynamic contrast-enhanced MR imaging at 6 weeks after surgery is valuable for assessing vascular bone graft perfusion, while similar imaging at 1 week may suggest otherwise.