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1.
目的 通过对冠状动脉(简称冠脉)支架植入前后进行99Tcm-甲氧基异丁基异腈(MIBI)心肌断层显像,以了解心肌灌注缺损程度,范围,判断,SPECT在术前筛选,术后疗效评价,后期随访中的价值。方法,对51例冠心病患者冠脉支架植入前后和21例植入后半年,分别做静态和潘生丁负荷SPECT检查,定量分析心肌灌注缺损的部位,程度及范围。结果 术前50例中,心肌血流灌注程度>80%(灌注缺损程度<20%),灌注缺损范围<20%(比值越大,灌注缺损面积越大)者为0例,术后1周有7例灌注缺损程度,8例灌注缺损面积已完全正常(14%和16%),术前严重灌注缺损<49%的34例(68%),术后1周16例(32%)有改善,术前严重灌注缺损面积>70%的35例,术后1周10例有改善,19.35%,术前和术后1周静态SPECT心肌灌注缺损面积为70.75%和55.91%,改善14.74%,在术后1周及半年心肌灌注缺损程度,灌注缺损面积均有明显改善(P<0.001),而术前,术后1周及术后半年潘生丁负荷SPECT心肌灌注缺损程度,灌注缺损面积与术前,术后1周及术后半年静息SPECT肌灌注缺损程度,灌注缺损面积差异无显著性(<3%,P>0.05),结论 定量分析术后1周和半年SPECT心肌灌注缺损程度,灌注缺损面积较大前有明显改善,SPECT对冠心病诊断,介入治疗前病例筛选,术后疗效评价及后期随访有临床应用价值。  相似文献   

2.
目的: 通过对冠状动脉(简称冠脉)支架植入前后进行静息和潘生丁负荷99mTc-MIBI断层显像(R-MPTI、P-MPTI),以了解SPECT在支架置入术前筛选、术后再狭窄评价中的价值.材料和方法: 95例冠心病患者在冠状动脉介入治疗前、术后3~6个月行R-MPTI和P-MPTI.潘生丁最大剂量时注射740MBq99mTc-MIBI,1h后行心肌断层显象;24h后重复静态心肌显象.与术后复查冠脉造影(CAG)对比,分析心肌灌注显像对支架术后再狭窄的诊断效果.结果: 95例冠心病患者共有855个心肌血流灌注节段,术前R-MPTI发现196个心肌血流灌注缺损,P-MPTI发现351个.支架置入后R-MPTI检查发现62个心肌血流灌注缺损病变节段,P-MPTI检查发现145个心肌血流灌注缺损病变节段.术后CAG随访92例,18例(18/92,19.6%)共29支血管发生再狭窄.按再狭窄冠脉支数计算,R-MPTI、P-MPTI对再狭窄的诊断准确性、阳性预测值和阴性预测值分别为84.5%、92.6%; 59.5%、75.7%;95.7%、98.9%,所有指标均有显著差异(χ~2=15.54)(P<0.01).结论: P-MPTI可以早期发现冠状动脉内支架术后再狭窄,诊断效率高于R-MPTI,有利于准确判断病情和指导治疗.  相似文献   

3.
目的 :研究潘生丁负荷后门控单光子发射计算机断层显像 (SPECT)是否能反映静息室壁运动 ,以及由潘生丁负荷所诱发的心肌顿抑。方法 :6 2例患者 (冠心病 5 7例 ,胸痛 5例 )首日进行潘生丁负荷门控 99Tcm -甲氧基异丁基异腈 (99Tcm - MIBI) SPECT和静息 2 0 1  Tl SPECT;次日行 2 4h延迟 2 0 1  Tl SPECT和静息门控 99Tcm- MIBI SPECT。负荷和静息门控 99Tcm- MIBI SPECT在注射显像剂 1h后进行。心肌被分为 17个节段 ,灌注分 4个标准 (0示正常、1示轻度减低、2示严重减低、3示缺损 ) ;室壁运动采用另外 4个标准 (0示正…  相似文献   

4.
目的 :异舒吉99mTc MIBI心肌断层显像比较直接经皮冠状动脉腔内成形术 (PTCA)与溶栓治疗急性心肌梗死的效果。材料与方法 :对 47例经直接PTCA治疗 (A组 )、溶栓再灌注成功 (B组 )和失败 (C组 )的急性心肌梗死患者行异舒吉和静态99mTc MIBI心肌显像。 2 0例经介入性治疗患者 ,术后 3个月复查静态心肌显像。结果 :不论是静态 ,还是异舒吉99mTc MIBI心肌显像 ,A组心肌缺损面积小于B组 ,B组小于C组 ,三组之间差异有显著性。与静态心肌显像比较 ,A组和B组异舒吉心肌显像提示心肌灌注明显改善 ,在C组改善不明显 ,其中A组异舒吉心肌显像灌注改善大于B组 C组。 15例介入治疗异舒吉显像有心肌存活者 ,术后心肌缺损面积缩小 ,由术前 36 3%± 2 2 6 %降至 2 2 0 %± 19 3%。 5例无心肌存活者 ,术后心肌缺损面积与术前比较无差异。结论 :异舒吉99mTc MIBI心肌断层显像定量分析显示直接PTCA术可减少心肌缺损面积 ,挽救更多的濒死心肌 ,同时可准确识别心肌梗死后存活心肌。  相似文献   

5.
目的异舒吉99mTc-MIBI心肌断层显像比较直接经皮冠状动脉腔内成形术(PTCA)与溶栓治疗急性心肌梗死的效果.材料与方法对47例经直接PTCA治疗(A组)、溶栓再灌注成功(B组)和失败(C组)的急性心肌梗死患者行异舒吉和静态99mTc-MIBI心肌显像.20例经介入性治疗患者,术后3个月复查静态心肌显像.结果不论是静态,还是异舒吉99mTc-MIBI心肌显像,A组心肌缺损面积小于B组,B组小于C组,三组之间差异有显著性.与静态心肌显像比较,A组和B组异舒吉心肌显像提示心肌灌注明显改善,在C组改善不明显,其中A组异舒吉心肌显像灌注改善大于B组+C组.15例介入治疗异舒吉显像有心肌存活者,术后心肌缺损面积缩小,由术前36.3%±22.6%降至22.0%±19.3%.5例无心肌存活者,术后心肌缺损面积与术前比较无差异.结论异舒吉99mTc-MIBI心肌断层显像定量分析显示直接PTCA术可减少心肌缺损面积,挽救更多的濒死心肌,同时可准确识别心肌梗死后存活心肌.  相似文献   

6.
目的 评价2 0 1 TlSPECT心肌显像在激光心肌再血管化 (TMLR)治疗缺血性心脏病中的价值。方法  19例心肌梗死病人均行TMLR治疗 ,经左第 5肋间 ,前外侧切口 ,显露心脏 ,使用高能量 (80 0W)CO2 心脏激光治疗仪于心脏跳动中作心肌打孔 ,经食管超声监测打孔情况 ,打孔部位在左心室游离壁 ,平均打孔前壁 (8 3± 2 9)个 ,侧壁 (6 9± 2 5 )个 ,下壁 (5 4± 2 0 )个 ,心尖 (5 3± 4 4)个。在TMLR治疗前 ,均行潘生丁负荷试验 (ST) “再分布”(RD) 硝酸甘油 (NTG)介入 再注射 (NTG RI) 2 0 1 TlSPECT心肌显像。潘生丁剂量按体重 0 7mg kg ,4min内慢速静脉推注 ,注射完 2min后 ,静脉注射2 0 1 Tl 111MBq ,10min后行SPECT心肌显像 ,“再分布”显像于 3~ 4h后进行。继而舌下含服硝酸甘油 0 6mg ,静脉再注射2 0 1 Tl37MBq,10min后行第 3次SPECT显像。TMLR治疗后随访 3个月显像17例 ,6个月显像 11例 ,1a显像 5例。结果  19例病人共有 5 6个心肌灌注异常节段 ,随机选取 45个节段行TMLR治疗。其中术后 18个节段心肌血流灌注有改善 ,治疗有效率为 40 %。术前RD NTG RI2 0 1 TlSPECT心肌显像有显著再分布的 18个节段 ,术后 77 8% (14个 )节段心肌灌注改善。术前2 0 1 TlSPECTRD心肌显像图上有显著再分布的  相似文献   

7.
目的 评价硝酸甘油 (NTG)介入99Tcm 甲氧基异丁基异腈 (MIBI)SPECT心肌显像对心肌梗死患者行经皮冠状动脉腔内成形术 (PTCA)决策的影响。方法  5 1例心肌梗死患者PTCA前 1周内行99Tcm MIBI静息和NTG介入心肌显像 ,术后 2~ 3个月内复查静息心肌显像 ,并进行对比分析。结果  5 1例患者共 14 1个心肌灌注异常节段 ,其中术后 74个节段心肌血流灌注改善 ,治疗有效率为5 2 4 8%。术前NTG介入显像表现为可逆性缺损 79个节段 ,术后 84 81% (6 7个 )节段心肌灌注改善 ,其中有明显填充的 5 8个节段 ,术后全部灌注改善。NTG介入显像表现为不可逆性缺损的 6 2个节段 ,有 11 2 9% (7个 )节段术后心肌灌注改善。NTG介入显像检测心肌存活的准确性为 86 5 2 %。结论NTG介入99Tcm MIBISPECT心肌显像对患者行PTCA起重要的决策作用。  相似文献   

8.
心肌灌注显像在PTCA支架术疗效判定和预后评估中的价值   总被引:2,自引:1,他引:2  
目的 探讨心肌灌注显像对经皮冠状动脉腔内成形术 (PTCA)支架术疗效判定和预后评估的价值。方法  75例行PTCA支架术患者 ,术后 3~ 1 2个月内行运动或药物负荷心肌灌注断层显像 ,其中 4 1例有术前显像对照。术后随访 1 3~ 98个月。结果  4 1例患者术后心肌灌注改善率为73 1 7%;75例术后显像为正常、可逆性缺损或固定性缺损患者间 ,心脏事件发生率整体差异有极显著性 (P <0. 0 0 1 ) ,其中可逆性缺损与正常和固定性缺损患者间发生率差异均有显著性 (P <0. 0 1 7) ;生存分析依术后显像结果不同 ,无心脏事件概率曲线整体分布差异有显著性 (P <0 . 0 5 ) ,其中可逆性缺损与正常和固定性缺损患者间曲线分布差异均有显著性 (P <0 .0 5 )。结论 心肌灌注显像在PTCA支架术后疗效判定和预后评估中有应用价值。  相似文献   

9.
硝酸甘油介入99Tcm-MIBI SPECT心肌显像对PTCA决策的影响   总被引:5,自引:0,他引:5  
《中华核医学杂志》2003,23(Z1):23-24
目的评价硝酸甘油(NTG)介入99Tcm-甲氧基异丁基异腈(MIBI) SPECT心肌显像对心肌梗死患者行经皮冠状动脉腔内成形术(PTCA)决策的影响.方法 51例心肌梗死患者PTCA前1周内行99Tcm-MIBI静息和NTG介入心肌显像,术后2~3个月内复查静息心肌显像,并进行对比分析.结果 51例患者共141个心肌灌注异常节段,其中术后74个节段心肌血流灌注改善,治疗有效率为52.48%.术前NTG介入显像表现为可逆性缺损79个节段,术后84.81%(67个)节段心肌灌注改善,其中有明显填充的58个节段,术后全部灌注改善.NTG介入显像表现为不可逆性缺损的62个节段,有11.29 %(7个)节段术后心肌灌注改善.NTG介入显像检测心肌存活的准确性为86.52%.结论 NTG介入99Tcm-MIBI SPECT心肌显像对患者行PTCA起重要的决策作用.  相似文献   

10.
目的:异舒吉^99mTc-MIBI心肌断层比较直接经皮冠状动脉内成形术(PTCA)与溶栓治疗急性心肌梗死的效果。材料与方法:对47例经直接PTCA治疗(A组)、溶栓再灌注成功(B组)和失败(C组)的急性心肌梗死患者异舒吉和静态^9mmTc-MIBI心肌显像。20例经介入性治疗患者,术后3个月复查静态心肌显像。结果:不论是静态,还是异舒吉^99mTc-MIBI心肌显像,A组心肌缺损面积小于B组,B组小于C组,三组之间差异有显著性。与静态心肌显像比较,A组和B组异舒吉心肌显像提示心肌灌注明显改善,在C组改善不明显,其中A组异舒吉心肌显像灌注改善大于B组+C组。15例介入治疗异舒吉显像有心肌存活者,术后心肌缺损面积缩小,由术前36.3%&#177;22.6%降至22.0%&#177;19.3%。5例无心肌存活者,术后心肌缺损面积与术前比较无差异。结论:异舒吉^99mmTc-MIBI心肌断层显像定量分析显示直接PTCA术可减少心肌缺损面积,挽救更多的濒死心肌,同时可准确识别心肌梗死后存活心肌。  相似文献   

11.
目的 研究潘生丁负荷试验脑血流灌注显像在缺血性脑血管病中的应用。方法 24例缺血性脑血管病患者和8例健康对照者均进行了静息和潘生丁负荷SPECT脑血流灌注显像,间隔时间1周内。显像剂为^99Tc^m-双半胱乙酯(ECD),仪器为Elscint Apex Sp-6 SPECT仪,潘生丁剂量按体重0.56mg/kg。结果采用半定量方法进行分析,比较静息及负荷显像探测脑缺血性病变的灵敏度及不对称指数。结果 潘生丁负荷试验脑血流灌注显像缺血性脑血管病判断病变的灵敏度可由静息时的58.3%提高至83.3%。对于椎基底动脉供血不足和短暂性脑缺血发作,负荷试验可将静息时的灵敏度从46.7%提高至73.3%,对照组负荷前后不对称指数差异无显著性,患者组不对称指数差异有显著性。患者组负荷后脑血管呈不同的反应类型。结论 潘生丁负荷脑血流灌注显像有助于脑血管病变的检出,有望用于探测脑血管储备力。  相似文献   

12.
BACKGROUND AND AIM: The angiotensin II type 1 (AT1) receptor antagonist irbesartan is used for the treatment of hypertension, but its anti-ischaemic effect is not yet known. Our aim was to assess the effect of irbesartan administration on the diagnostic yield of 99mTc sestamibi single photon emission computed tomography (SPECT) in patients with coronary artery disease (CAD) after dipyridamole stress. METHODS: Our study group consisted of 13 patients (11 men and two women; mean age, 53.3 +/- 10.6 years; body mass index, 26.9 +/- 3.3 kg x m(-2)) with angiographically documented CAD. All patients underwent SmTc sestamibi SPECT studies at rest, before (STRESS-1) and 2 weeks after irbesartan (150 mg daily) administration (STRESS-2) at dipyridamole stress. The extent and severity of defects were analysed by using visual and quantitative 99mTc sestamibi SPECT. RESULTS: The mean summed stress score was significantly higher during the STRESS-1 study than the STRESS-2 study (13.2 +/- 7.4 vs. 11 +/- 7.4, P=0.003). The mean size of perfusion defects at stress was significantly larger for the STRESS-1 group than the STRESS-2 group (17.8% +/- 2.85% vs. 15.3% +/- 2.95%, P=0.01). CONCLUSION: Our study showed that the AT1 receptor blocker irbesartan reduces the extent and severity of 99mTc sestamibi perfusion defects after dipyridamole stress in patients with CAD. Irbesartan may alter coronary blood flow reserve. The continued use of irbesartan before stress myocardial perfusion SPECT has a masking effect on stress induced myocardial perfusion defects. For this reason AT1 receptor blockers must be stopped before stress myocardial perfusion scintigraphic examinations.  相似文献   

13.
To determine the effect of cranial irradiation on hypothalamic blood flow, we performed 44 regional cerebral blood flow studies with 99mTc hexamethyl propyleneamine oxime (HMPAO) single-photon emission CT (SPECT) on four normal volunteers and 34 patients with pathologically proved nasopharyngeal cancer. Twenty-three men and 15 women, 30-65 years old, were divided into four study groups: group 1 served as a control and consisted of four normal volunteers and six patients studied prior to cranial irradiation; group 2 patients had cranial irradiation half a year before the SPECT study (n = 12, one from group 1); group 3 patients were irradiated 1 year before the study (n = 13, three from group 1 and two from group 2); and group 4 patients were irradiated at least 5 years before SPECT imaging (n = 9). Six patients were studied twice. Quantification of the 99mTc-HMPAO brain SPECT studies was done separately by three radiologists to obtain the hypothalamus/occipital (H/O) and hypothalamus/parasagittal (H/P) ratios. Endocrinologic studies were performed in all cases and the hypothalamus-thyrotroph-thyroid, hypothalamus-gonadotroph-testis (ovary), hypothalamus-lactotroph, hypothalamus-somatotroph, and hypothalamus-corticotroph-adrenal axes were evaluated separately. We determined that regional hypothalamic blood flow was reduced after cranial irradiation in patients with nasopharyngeal cancer. The H/O ratio of groups 3 and 4 did not differ from that of group 2 (one-half year after cranial irradiation). The H/O ratio was significantly reduced 6 months and 1 year after cranial irradiation; mean +/- SD = 0.5801 +/- 0.0829 (p less than .025), 0.5725 +/- 0.0791 (p less than .01) versus 0.6477 +/- 0.0458 before cranial irradiation, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

14.
潘生丁与乙酰唑胺负荷脑血流灌注显像的对比研究   总被引:1,自引:0,他引:1  
目的 探讨潘生丁负荷脑血流灌注显像的可行性。方法 8例健康志愿者和23例患者于1周内先后进行静息、乙酰唑胺及潘生丁负荷脑血流灌注显像。自身比较静息,负荷状态下的脑血流灌注情况。结果健康志愿者的脑血流灌注双侧对称。患者组中8例正常;1例患者静息态脑局部血流灌注低下,潘生丁和乙酰唑胺负荷态正常;余14例静息态局部脑血流灌注低下或正常,应用潘生丁,乙酰唑胺后局部脑血流量更低或出现低灌注区。两药显示低血流储备区的能力无明显差异。结论 潘生丁可以替代乙酰唑胺实施负荷脑血流灌注显像。  相似文献   

15.
BACKGROUND: Changes induced by dipyridamole infusion on left ventricular function in healthy individuals have not been investigated by gated myocardial perfusion single photon emission computed tomographic (SPECT) imaging. METHODS AND RESULTS: This study examined the amplitude and duration of changes induced by dipyridamole infusion on left ventricular function as assessed by technetium 99m sestamibi gated SPECT in 18 subjects with a low likelihood of coronary artery disease. Twenty mCi (740 MBq) of Tc-99m sestamibi were injected at rest. Three different consecutive gated SPECT images were performed 60 minutes later: baseline at rest, during the infusion of 0.76 mg/kg of dipyridamole, and 1 hour later. No patient received aminophylline. Left ventricular ejection fraction (LVEF), end-diastolic volume, and end-systolic volume were automically computed. Heart rate (HR) and blood pressure were regularly monitored. Mean LVEF was 63.2% +/- 8.0% baseline at rest, increased to 73.8% +/- 8.2% (P = .0001) during dipyridamole infusion, and returned to baseline values (63.0% +/- 7.5%) 1 hour later. End-diastolic volume did not vary significantly, and end-systolic volume decreased (from 32.2 +/- 19.5 to 26.6 +/- 17.9 u, P = .002) and returned to baseline values (32.7 +/- 15.6 u) 1 hour later. Dipyridamole induced moderate HR acceleration (from 80.2 +/- 15.0 to 96.5 +/- 9.6 beats/min, P < .001) and a slight decrease in diastolic blood pressure (from 80.6 +/- 8.1 to 70.1 +/- 9.0 mm Hg, P < .001). However, 1 hour later, HR and blood pressure had returned to baseline values. CONCLUSIONS: Dipyridamole increases LVEF and HR and decreases diastolic blood pressure slightly in healthy individuals. Because dipyridamole gated SPECT imaging acquisition is usually started 60 minutes after dipyridamole infusion, LVEF is in fact estimated at rest.  相似文献   

16.
目的 探讨冠状动脉痉挛患者核素心肌灌注显像反向再分布(RR)的机制.方法 选择双嘧达莫负荷201TI心肌灌注显像表现为RR且诊断为冠状动脉痉挛的患者26例(RR组)、无冠状动脉狭窄及RR者16例(对照组),在冠状动脉造影术中重复双嘧达莫试验,测量并比较注射双嘧达莫前后RR相关、非RR相关血管和对照组相应血管的校正心肌梗死溶栓疗法(TIMI)血流帧计数(CTFC)和心肌血流灌注积分(TMPG).统计学处理采用t检验、χ2检验及相关分析.结果 冠状动脉造影见RR相关血管僵硬,血流速度和心肌灌注明显低于非RR相关血管,且RR区域静态心肌灌注缺损与冠状动脉造影血流速度缓慢高度相关(r=0.79,t=10.18,P<0.001) 而对照组的各支冠状动脉血流速度和心肌灌注无明显差异.RR相关血管注射双嘧达莫前后CTFC分别为(36±6)帧及(26±7)帧(t=4.15,P<0.01) TMPG分别为(2.02±0.39)级和(2.92±0.12)级(t=2.25,P<0.05) 非RR相关血管注射前后CTFC分别为(29±7)帧及(25±5)帧(t=2.31,P<0.05) TMPG分别为(2.56±0.31)级和(2.96±0.06)级(t=2.17,P<0.05) 而对照组注射双嘧达莫前后TCFC及TMPG均无明显变化(t=0.932及0.867,P均>0.05).结论 冠状动脉痉挛患者静息状态下RR相关血管及微血管处于轻度痉挛状态,导致血流速度及心肌灌注缓慢 而负荷状态下血管扩张,使血流速度和心肌灌注加快,因而呈现RR.  相似文献   

17.
We investigated whether poststress gated SPECT, which was believed to show resting wall motion, revealed stunning induced by dipyridamole stress. METHODS: In 62 patients with coronary artery disease (n = 57) or chest pain (n = 5), dipyridamole stress gated 99mTc-hexakis-2-methoxyisobutyl isonitrile (MIBI) SPECT and rest 201Tl SPECT were performed on the first day; 24-h delayed 201Tl SPECT and rest gated 99mTc-MIBI SPECT were performed on the second day. Stress and rest gated 99mTc-MIBI SPECT was performed 1 h after injection. The myocardium was divided into 17 segments, and perfusion was scored on a 4-point scoring system (scores, 0-3 for normal to defect); wall motion during first-day poststress gated and second-day rest gated SPECT was also scored on another 4-point scale (scores, 0-3 for normal to dyskinesia). RESULTS: Thirty-one of 62 patients showed wall motion abnormality that was worse after stress than during resting. Three hundred eight (29%) of the total 1054 segments showed wall motion abnormality on poststress gated SPECT. In 198 of these segments, wall motion abnormality was the same on poststress and rest gated SPECT, and 106 segments showed wall motion that was worse on 1-h poststress than on rest gated SPECT. Perfusion was normal either during rest (n = 113) or after a 24-h delay (n = 18) in 131 segments with the poststress wall motion abnormality. Of these 131 segments, 69 showed the same wall motion abnormality between poststress and resting periods (persistent stunning). However, in 40 segments, abnormal wall motion on 1-h poststress gated SPECT normalized on rest gated SPECT (transient prolonged stunning). The other 20 segments showed improvement of wall motion during rest compared with the poststress period but still showed abnormal wall motion during the resting period (between transient prolonged stunning and persistent stunning). Stress perfusion decrease was more severe in transient prolonged stunning than in persistent stunning. Poststress wall motion abnormality was more severe in persistent stunning. CONCLUSION: Using gated 99mTc-MIBI SPECT, stunned myocardium was found on 1-h poststress SPECT compared with normal resting wall motion found on rest gated SPECT on the next day. We conclude that some myocardial walls did not show true resting wall motion on 1-h poststress gated SPECT; hence, caution is necessary when using wall motion on 1-h poststress gated SPECT to assess resting wall motion.  相似文献   

18.
This study was done to determine whether the rapidly clearing myocardial perfusion agent 99mTc-teboroxime (SQ 30217, Cardiotec) could be combined with tomographic imaging to accurately quantify regional myocardial blood flow distribution in anesthetized dogs. Following stenosis of the anterior descending (LAD, n = 10) or circumflex (LCX, n = 5) coronary arteries, teboroxime was administered simultaneously with radioactive microspheres, at rest and following infusion of dipyridamole (0.15 mg/kg/min x 4 min). Tomographic imaging began 1 min after each teboroxime injection and continued for 12 min. For LAD stenosis, when the dipyridamole study was performed first, teboroxime activity in the center of the ischemic region was closely correlated with tissue microsphere content. However, the severity of the dipyridamole-induced flow deficit was underestimated by teboroxime when the rest study was performed first. Our results show that despite rapid myocardial clearance, tomographic imaging of 99mTc-teboroxime provides reasonably accurate quantitation of dipyridamole-induced anterior wall perfusion defects, but that the flow deficit is underestimated when a rest study is performed first or when the defect is located in the inferior wall.  相似文献   

19.
Background. The purpose of this study was to investigate the quantitative properties of ordered-subset expectation maximization (OSEM) on kinetic modeling with nitrogen 13 ammonia compared with filtered backprojection (FBP) in healthy subjects. Methods and Results. Cardiac N-13 ammonia positron emission tomography (PET) studies from 20 normal volunteers at rest and during dipyridamole stimulation were analyzed. Image data were reconstructed with either FBP or OSEM. FBP- and OSEM-derived input functions and tissue curves were compared together with the myocardial blood flow and spillover values. The late area under the OSEM input functions during dipyridamole is overestimated by 30% (P<.0001) relative to FBP. Conversely, the area under the late part of the OSEM tissue curves is underestimated by 20% (P<.0001) compared with FBP during both rest and dipyridamole. These differences in tissue and input functions cause the resting myocardial blood flow to be underestimated by 15% (P<.0001). During dipyridamole, the OSEM flow is underestimated by 25% (P<.0001) relative to FBP, causing the myocardial flow reserve to be underestimated by 10% (P<.0001). Large inter-regional differences in FBP and OSEM flow values were observed with a flow underestimation of 45% (rest/dipyridamole) in the septum and of 5% (rest) and 15% (dipyridamole) in the lateral myocardial wall. Conclusions. OSEM reconstruction of myocardial perfusion images with N-13 ammonia and PET produces high-quality images for visual interpretation. However, compared with FBP, OSEM is associated with substantial underestimation of perfusion on quantitative imaging. Our findings indicate that OSEM should be used with precaution in clinical PET studies. An abstract of this article was presented at the 6th International Conference of Nuclear Medicine, Florence 2003, April 29–May 1, 2003.  相似文献   

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