Assessment of SPECT ventilation-perfusion imaging in patients with lung cancer

Ventilation and perfusion SPECT images during tidal breathing were studied in 15 cases of lung cancer using ^81mKr gas and ^99mTc-microspheres. Furthermore, functional images of V/Q ratio and Q/V ratio were prepared, and their clinical significance is descussed with reference to general lung function. There was a decreas in %VC and %FEV _1.0in 7 of 15 cases, and an increase of AaDo₂ in the blood gas analysis in 12 of 15 cases. Both planar and SPECT images showed ventilation and perfusion abnormalities in all 15 cases. Of these, 12 patients showed matched ventilation and perfusion defects, 2 patients a dead-space effect and 1 patient a shunt effect. In comparing planar and SPECT images, depiction of ventilation and perfusion impairments were equally clear in 11 cases, but in 3, showing a lobar or segmental defect with a shunt effect, the SPECT images were superior. In a patient with markedly impaired function of the affected lung, the remaining function could not be depicted by SPECT. From the above, it seems that better information can be obtained for understanding the ventilation and perfusion states of lung cancer by adding the SPECT images to the planar image.     

A technique for lung ventilation-perfusion SPECT in neonates and infants

BACKGROUND: Single photon emission tomography (SPECT) of the lung is a well-established non-invasive technique for quantitative assessment of regional lung ventilation and perfusion distribution in children and in adults. However, its application in neonates as well as infants has been scarce because of several practical limitations, such as the trade off between image quality and restricted effective radiation doses and the lack of suitable inhalations agents and administration techniques. METHODS: In this paper, a new technique for quantitative regional lung SPECT based on a passive Technegas administration procedure is described and clinically applied. The first clinical findings in neonates are reported. RESULTS: This technique overcomes some of the limitations of commercial ventilation systems by making patient compliance unnecessary, avoiding difficult breathing manoeuvres and by minimizing both facemask dead space and inspiratory-expiratory resistance. CONCLUSION: This technique satisfies requirements for routine applications in neonates, infants and even older patients and has a potential use also for mechanically ventilated patients. It has the potential to allow a more precise functionally oriented diagnosis, which is of importance for treatment and follow-up in patients with severe lung diseases.     

Pulmonary ventilation-perfusion MR imaging in clinical patients

The purpose of this study was to evaluate the feasibility of comprehensive magnetic resonance (MR) assessment of pulmonary perfusion and ventilation in patients. Both oxygen-enhanced ventilation MR images and first-pass contrast-enhanced perfusion MR images were obtained in 16 patients with lung diseases, including pulmonary embolism, lung malignancy, and bulla. Inversion recovery single-shot fast spin-echo images were acquired before and after inhalation of 100% oxygen. The overall success rate of perfusion MR imaging and oxygen-enhanced MR imaging was 94% and 80%, respectively. All patients with pulmonary embolism showed regional perfusion deficits without ventilation abnormality on ventilation-perfusion MR imaging. The results of the current study indicate that ventilation-perfusion MR imaging using oxygen inhalation and bolus injection of MR contrast medium is feasible for comprehensive assessment of pulmonary ventilation-perfusion abnormalities in patients with lung diseases.     

肺SPECT显像在肺癌放疗中保护肺功能的应用

目的 研究肺癌放疗计划制定中结合肺单光子发射型计算机断层摄影术(SPECT)图像有效保护放疗中功能肺的可行性。方法 选取11例肺癌患者先行CT模拟定位,后在相同体位下行肺SPECT显像检查。利用治疗计划系统将CT图像与SPECT图像融合,通过融合图像在CT图像上勾画出功能肺。分别设置优化参数制定两种计划(T1和T2)进行比较。T1不考虑肺功能分布,T2充分考虑肺功能分布并尽可能降低功能肺受照剂量。脊髓、心脏等器官分别设置限制参数。肺癌病灶放疗2 Gy/次,总剂量66 Gy。结果 在保证计划靶体积达处方剂量且无差别及脊髓最大剂量小于45 Gy前提下,T1计划的功能肺受照体积V₅、V₁₀、V₂₀分别为(63.45±4.20)%、(48.45±3.87)%、(22.66±2.01)%,T2计划的分别为(61.51±4.05)%、(40.93±3.23)%、(19.45±1.74)%,与T1相比较明显下降(P<0.05)。T1计划的功能肺V₃₀、V₄₀、V₅₀分别为(13.34±1.67)%、(7.83±1.18)%、(4.14±0.68)%,T2计划的分别为(12.69±1.54)%、(8.10±1.30)%、(4.53±0.82)%,与T1相比较无明显下降(P>0.05)。结论 结合肺SPECT图像制定肺癌放疗计划能降低功能肺受照剂量,由此可减少并发症、改善患者生活质量。     

99Tcm-甲氧基异丁基异腈SPECT评价非小细胞肺癌化疗疗效

目的探讨99Tcm-甲氧基异丁基异腈（99Tcm-MIBI）SPECT评估非小细胞肺癌（NSCLC）化疗疗效的价值。方法71例NSCLC患者根据胸部CT分为化疗有效组（完全缓解＋部分缓解）和无效组（病情稳定＋疾病进展）,于化疗前行99Tcm-MIBISPECT,静脉注射99Tcm-MIBI740MBq后10～30min及2—3h分别行早期及延迟显像,在99Tcm-MIBI显像图上用感兴趣区（ROI）的方法勾画出病灶,然后选取镜像ROI于健侧肺的相应部位,由此分别获得早期相肿瘤／正常肺组织摄取比值（ER）和延迟相肿瘤／正常肺摄取比值（DR）,并计算滞留指数（RI）。采用t检验及秩和检验分析化疗有效组与化疗无效组ER、DR和RI之间的差别。结果99Tcm-MIBI显像结果中,化疗有效组的ER、DR分别为2．39±0．21、2．50±0．19,均显著高于化疗无效组的1．89±0．19、2．05±0．21,统计学差异有意义（t=8．311、8．480,P〈0．05）。化疗有效组的RI中位值为6．63％,高于化疗无效组的5．13％,统计学差异有意义（Z=2．416,P〈0．05）。结论99Tcm-MIBI显像在评估NSCLC化疗疗效方面具有重要的临床价值。     

Assessment of myocardial viability with SPECT and PET imaging

The use of thrombolytic therapy for the treatment of acute myocardial infarction has increased the number of patients presenting for assessment of myocardial viability. Stress SPECT 201Tl perfusion imaging performed in the conventional manner with delayed imaging at 4 hr can identify a large percentage of patients with ischemic but viable areas of myocardium. In some patients, delayed imaging up to as long as 24-48 hr after exercise may be required to show 201Tl redistribution indicative of viability. Thus, in most patients, stress 201Tl scintigraphy will correctly identify the presence of viable myocardium. PET imaging, with its ability to assess blood flow and metabolism separately, offers the ability to identify myocardial areas with diminished blood flow but preserved metabolism. Areas with such a blood flow-metabolism mismatch may benefit from revascularization, even in the absence of 201Tl redistribution. The exact role PET will play in the initial evaluation of patients presenting for assessment of myocardial viability remains to be established as more clinical data are accumulated.     

Quantitative assessment of ventilation-perfusion mismatch by radioxenon imaging of the lung

By the use of xenon-133 and a scintillation camera with digital data storage and processing system, a topographic relationship between ventilation distribution (V) and perfusion distribution (Q) was examined quantitatively in two groups of normal nonsmokers and one of older smokers, all healthy. In addition, subjects with a variety of cardiopulmonary disease were tested. The fractional regional ventilation (VR) and regional perfusion (QR) were plotted against the V/Q ratio on a logarithmic abscissa for the normal subjects; both were distributed log-normally with a narrow standard deviation, and were dissociated slightly from each other. However, with smoking and with increasing age, the s.d. and the dissociation became wider, suggesting an impairment of gas exchange as estimated by alveolar-atrial gas-pressure differences (A-aD), which were calculated by putting these topographic relationships into a gas-exchange program in a computer. In various cardiopulmonary diseases a good correlation was found between the estimated A-aDO2 thus obtained and the actual A-aDO2 derived from analysis of the blood gases.     

Oxygen-enhanced MR imaging: correlation with postsurgical lung function in patients with lung cancer

PURPOSE: To prospectively determine if lung function as assessed with oxygen-enhanced magnetic resonance (MR) imaging correlates with postsurgical lung function in patients with lung cancer, as compared with quantitative and qualitative findings of computed tomography (CT) and scintigraphy. MATERIALS AND METHODS: Study received institutional review board approval, and informed patient consent was obtained. Thirty consecutive patients (16 men and 14 women, aged 44-81 years; mean age, 65 years) considered candidates for lung resection underwent oxygen-enhanced MR imaging, CT, perfusion scintigraphy, and measurement of forced expiratory volume in 1 second (FEV1). A respiratory-synchronized inversion-recovery half-Fourier single-shot turbo spin-echo MR sequence was used for data acquisition. Correlation of postsurgical lung function (postsurgical FEV1) as determined with oxygen-enhanced MR imaging (FEV1MR), quantitative assessment with CT (FEV1Quant), qualitative assessment with CT (FEV1Qual), and perfusion scintigraphy (FEV1PS) was conducted with actual postsurgical FEV1, and the limits of agreement of each were determined with Bland-Altman analysis. RESULTS: Correlation between postsurgical FEV1MR and actual postsurgical FEV1 values was excellent (r2= 0.81, P < .001); it was better than that of FEV1Qual (r2= 0.76) and FEV1PS (r2= 0.77) and similar to that of FEV1Quant (r2= 0.81) values. The limits of agreement of FEV1MR were between -9.9% and 10.9%. CONCLUSION: Oxygen-enhanced MR imaging can be used to predict posturgical lung function in patients with lung cancer, similar to quantitative CT.     

非小细胞肺癌放疗中99Tcm-HL91 SPECT乏氧显像研究

目的通过99Tcm-4,9-二氮-3,3,10,10-四甲基十二烷-2,11-二酮肟(HL91)系列乏氧显像研究非小细胞肺癌放疗前、中和后乏氧的变化.方法拟接受三维适形放疗的非小细胞肺癌患者20例,放疗前1～2 d、放疗过程中(接受30～40 Gy照射)和放疗后1～2 d分别行99Tcm-HL91 SPECT显像.利用感兴趣区(ROI)技术计算肿瘤/对侧相应部位放射性计数比值(T/N),分析放疗不同时期肿瘤乏氧的变化.结果放疗前、中和后显像的T/N(4 h)分别为1.56±0.19,1.40±0.12和1.29±0.13,差异有显著性(P=0.01).结论该实验为研究人体肿瘤再氧合提供了有价值的信息.     

冠状动脉肌桥患者核素心肌灌注显像研究

目的 探讨用负荷心肌灌注显像检测冠状动脉(简称冠脉)肌桥心肌缺血的临床价值.方法 96例经冠脉造影证实为左前降支肌桥,不合并冠脉粥样硬化病变,且无心肌梗死病史的住院患者,接受运动或药物负荷心肌灌注显像,并进行1年的随访观察.结果 全部96例肌桥患者,收缩期压迫血管的平均狭窄程度为(65±19)%.负荷心肌灌注显像共发现20例心肌缺血,阳性率为20.8%(20/96),明显高于负荷试验心电图(2.1%).对于肌桥压迫血管呈重度狭窄(≥75%)者,负荷心肌灌注显像发现心肌缺血的比例(50%)明显高于轻中度狭窄组(6.3%,χ2=24.758,P＜0.001);静息心电图表现为ST-T改变的肌桥患者,负荷心肌灌注显像的阳性率明显高于心电图正常组(54.2%和9.7%,χ2=21.558,P＜0.001).随诊期间,负荷心肌灌注显像阳性组中,有1例发生心绞痛;而显像阴性组中,无一例发生心脏事件.结论 压迫血管狭窄严重以及静息心电图异常的肌桥患者,负荷心肌灌注显像发现心肌缺血的比例较高.负荷心肌灌注显像对于检测肌桥所致心肌缺血以及预后判断具有一定的临床应用价值.     

Myocardial perfusion SPECT imaging in patients with myocardial bridging

BACKGROUND: Although myocardial perfusion single photon emission computed tomography (SPECT) imaging is widely used to assess myocardial ischemia in patients with known or suspected coronary artery disease, only a few patients with myocardial bridging have been evaluated with nuclear techniques. Furthermore, it has been suggested that dipyridamole stress images might underestimate perfusion defects compared with exercise stress images. This study was done to determine the concordance of exercise stress SPECT images with that obtained by dipyridamole stress SPECT images as a means of detecting ischemia in patients with myocardial bridging. METHODS AND RESULTS: Sixteen consecutive patients with angina and normal arteries but myocardial bridging of the left anterior descending artery underwent rest-exercise stress SPECT imaging. Within 2 weeks after angiograms were obtained, only dipyridamole stress images were repeated. The mean angiographic systolic occlusion within the myocardial bridges was 73% +/- 10%. Overall, the prevalence of an abnormal scan was no different in patients who underwent exercise stress myocardial perfusion imaging (MPI) as compared with patients who underwent dipyridamole stress MPI (14/16 [88%] vs 13/16 [81%], respectively; P = .953). Exercise stress MPI showed a higher stress score than dipyridamole stress MPI, but the difference did not reach statistical significance (7.5 +/- 3.3 vs 6 +/- 2.7, P = .147). The strength of agreement among exercise stress MPI and dipyridamole stress MPI studies was good (kappa = 0.765; 95% CI, 0.318 to 1.211; P < .05). CONCLUSIONS: Cardiac SPECT studies can be used effectively for assessing ischemia in patients with angina and myocardial bridging. The evaluation of myocardial perfusion with dipyridamole stress SPECT imaging showed a good agreement with exercise stress SPECT imaging for the detection of ischemia in this group of patients.     

Tc-99m MIBI SPECT in prediction of prognosis in patients with small cell lung cancer

PURPOSE: The purpose of this study was to evaluate whether the degree of technetium-99m methoxyisobutylisonitrile (MIBI) uptake and its retention in delayed imaging in small cell lung cancer (SCLC) was correlated with the response to multiagent chemotherapy and to investigate if there was a relationship between the survival time of patients with SCLC and Tc-99m MIBI SPECT tumor uptake parameters at the time of diagnosis. METHODS: Between 1998 and by December 2004, 40 patients with SCLC were studied with Tc-99m MIBI SPECT at the time of diagnosis. The patients were classified by a follow-up CT as good responders (complete or partial remission) and poor responders (stable disease or progressive disease). Following i.v. administration of 740 MBq Tc-99m MIBI, SPECT imaging at 30 minutes (early) and 2 hours (delayed) was performed. Regions of interests were placed over the tumors and contralateral normal lung tissue on one transverse section. The uptake ratio of the lesion to that in the contralateral normal lung was obtained from early images (early ratio; ER) as well as delayed images (delayed ratio; DR). The retention index (RI%) was measured as: RI% = [(DR-ER)/ER] x 100. Tc-99m MIBI tumor uptake parameters were compared with chemotherapeutic response and survival time. RESULTS: Of 40 patients, 29 patients were good responders (72.5%) and 11 patients were poor responders (27.5%). RI% of Tc-99m MIBI SPECT in the group of good response was significantly higher than in that with poor response (p < 0.05). On the other hand, there was no significant difference between the two groups with respect to ER or DR values. Four of 40 patients were still alive with disease (10%). The patient survival time varied from 1 to 70 months (mean survival time = 12.9 +/- 13.4 months). There was no significant difference between the survival time of patients with respect to ER or DR of Tc-99m MIBI SPECT imaging. When median RI% was accepted as a cut-off value (-3.85%), patients with higher RI% values had a longer survival time (12 months) when compared with those with low RI% (8 months), p < 0.05. CONCLUSION: Our results suggest that Tc-99m MIBI SPECT could accurately predict the chemotherapy response in patients with SCLC. RI% of Tc-99m MIBI SPECT is recommended to differentiate patients with a poor response to chemotherapy and good responders, and RI% of Tc-99m MIBI SPECT appears as the only parameter that may be useful in predicting the survival of patients with SCLC.