18F-FDG符合线路SPECT/CT显像半定量分析对肺部病变的诊断价值

_目的：探讨18 F-FDG 符合线路 SPECT/CT 显像对肺部病变的诊断价值。方法：回顾性分析经病理或随访证实的144例肺部病变患者的18 F-FDG 符合线路 SPECT/CT 检查图像,采用半定量法测量肺部病灶放射性计数（T）与胸壁软组织放射性计数（NT）,并计算其放射性摄取比值 R（T/NT）,应用受试者工作特征（ROC）曲线确定肺部良恶性病变的最佳临界值 R（cutoff）,即 R≥R（cutoff）诊断为恶性病变,R＜R（cutoff）诊断为良性病变。结果：R（cutoff）取3．58,即病灶R≥3．58作为恶性的判定标准,诊断敏感度、特异度、准确率、阳性预测值和阴性预测值分别为89．5％、89．7％、89．6％、95．9％和76．1％,且与病理诊断的一致性良好（Kappa＝0．750,P＜0．05）。结论：18 F-FDG 符合线路 SPECT/CT 显像对肺部病变的诊断、鉴别诊断及预后评估具有重要的临床应用价值。     

孤立性肺结节18F-FDG SPECT显像的半定量研究

目的用半定量方式探讨不同病理类型孤立性肺结节在SPECT摄取18F-FDG的差异。资料与方法回顾性分析69例孤立性肺结节SPECT显像结果,半定量法(T/N)研究不同病理类型肺结节摄取18F-FDG的差异。结果恶性病变摄取18F-FDG比值明显高于良性病变,鳞癌摄取18F-FDG比值高于腺癌,差异均有统计学意义;良性病变之间差异无统计学意义。结论 18F-FDG摄取值半定量分析对孤立性肺结节良、恶性鉴别有重要意义,对恶性病变病理类型有一定预测价值。     

11C-胆碱与18F-FDG双时相PET显像在孤立性肺结节鉴别诊断中的应用

目的 比较^11C-胆碱、18F-脱氧葡萄糖（FDG）和^18F-FDG双时相PET显像对鉴别肺部孤立性结节良恶性的价值。方法16例临床疑为肺肿瘤的患者进行^18F-FDGPET显像（注药后1h显像，2h后行延迟显像）、^11C-胆碱PET显像（3d内，于注药后10min进行）。图像判断以标准摄取值（SUV）作为半定量指标，异常放射性浓聚灶以SUV〉2．5为葡萄糖代谢增高，^18F-FDG延迟显像SUV上升≥10％为恶性病变（阳性），如下降或升高〈10％为良性病变（阴性）；^11C-胆碱异常摄取灶以SUV〉2．0为阳性。所有病例进行随访，以显像诊断是否符合病理检查结果作为判断标准。结果病理检查结果证实12例肺癌，3例结核，1例结节病。^11C-胆碱PET显像确诊了12例肿瘤中的ll例，而^18F-FDG PET显像确诊10例（10／12例），双时相^18F-FDG PET显像确诊11例。4例良性病变者，^11C-胆碱PET显像能较好鉴别；而^18F-FDG PET显像2例假阳性，结合延迟显像仅1例假阳性。结论 ^11C-胆碱和^18F-FDG PET显像均能较好地鉴别肺部良恶性肿瘤。但^11C-胆碱和双时相^18F-FDGPET显像优于常规^18F-FDGPET显像，三者联合能提高对肺部病变的诊断效率。     

SPECT/CT符合线路显像对肺腺癌摄取^18F-FDG影响因素的研究

目的：应用SPECT/CT符合线路显像半定量分析,探讨肺腺癌摄取^18F-FDG的影响因素。方法：31例肺腺癌患者行SPECT/CT检查,计算肿瘤组织与周围正常软组织（T/N）的摄取比值,分析性别、病灶大小、肿瘤细胞分化程度等因素与肺腺癌摄取^18F-FDG的相关性。结果：肿瘤病灶大小、癌细胞的分化程度对肺腺癌摄取18F-FDG的影响有显著性意义（P〈0.05）;性别对肺腺癌摄取^18F-FDG的影响无显著性意义。结论：肺腺癌对18F-FDG摄取与肿瘤病灶大小、癌细胞的分化程度有关,与性别无关,^18F-FDG摄取值高提示病灶的恶性程度高。     

肺部病变18F-FDGSPECT符合线路显像

目的:探讨18F-FDG SPECT符合线路显像对肺部病变的定性诊断价值。材料和方法:用双探头SPECT符合线路对肺部病变患者进行18F-FDG肿瘤代谢显像,分析检查结果并与CT进行比较。结果:48例肺部病变患者18F-FDG显像诊断结果为真阳性37例,真阴性7例,假阳性3例和假阴性1例。其诊断的准确率、灵敏度和特异性分别为91.7％,97.4％和70％。诊断准确率显著高于CT检查。结论:18F-FDG SPECT符合线路显像对肺部病变具有较高的定性诊断价值。     

18F-FDG PET/CT显像诊断心包恶性病变的价值

目的 评价18F-脱氧葡萄糖（FDG）PET/CT对心包恶性病变的诊断价值.方法 对23例心包积液患者进行18F-FDG PET/CT显像,并采用两独立样本非参数检验分析良恶性病灶最大标准摄取值（SUVmax）差异有无统计学意义.结果 经病理检查证实恶性心包积液14例,良性心包积液9例.1例PET/CT假阴性,2例PET/CT假阳性.18F-FDG PET/CT鉴别诊断良恶性心包积液的灵敏度、特异性、准确性、阳性预测值、阴性预测值分别为92.9%（13/14）、7/9、87.0%（20/23）、86.7%（13/15）和7/8.良、恶性病变的SUVmax中位值分别为2.2和6.0,两者间比较差异有统计学意义（z=-3.279,P=0.001）.结论 18F-FDG PET/CT是评价心包恶性病变较好的无创性手段,对良恶性心包积液的诊断与鉴别诊断有一定临床价值.     

18F-FDG符合线路显像在食管癌术前分期中的价值

目的 探讨^18F-FDG符合线路显像在食管癌术前分期中的价值。方法 35例食管癌患者术前行^18F—FDG符合线路显像及CT检查，其中30例行手术治疗，以术后病理检查结果作为“金标准”，比较^18F—FDG符合线路显像及CT检查对原发肿瘤、淋巴结及远处转移（TNM）分期的价值；另5例发现远处转移，放弃手术治疗。结果 ^18F-FDG符合线路显像T分期与病理T分期比较符合率为63％（19／30）；^18F-FDG与CT探测淋巴结病变的灵敏度为60．00％和54．28％，特异性为94．44％和77．77％，准确性为84．80％和71．20％，阴性预测值为85．86％和81．39％，阳性预测值为80．77％和48．72％，其中特异性、准确性及阳性预测值差异有统计学意义。^18F—FDG符合线路显像发现5例远处转移，改变了其治疗方案。结论 ^18F-FDG符合线路显像对食管癌的术前分期、治疗方案的制定有临床应用价值。     

18F-FDG符合线路显像对食管癌术后复发转移的诊断价值

目的 探讨^18F-脱氧葡萄糖（FDG）符合线路显像对食管癌术后复发转移的诊断价值。方法 对29例临床怀疑复发转移的食管鳞状细胞癌术后患者行^18F-FDG符合线路显像，计算其诊断复发转移灶的灵敏度、特异性和准确性，并与CT诊断结果比较。结果 29例患者中符合线路显像真阳性19例，真阴性6例，假阳性、假阴性各2例，其诊断食管癌术后复发转移的灵敏度、特异性和准确性分别为90．5％（19／21例）、75．0％（6／8例）和86．2％（25／29例）；而CT诊断的灵敏度、特异性和准确性分别为71．4％（15／21例）、87．5％（7／8例）和75．9％（22／29例）。在符合线路显像与CT检查均阳性的13例患者中，CT检出病灶20个；而符合线路显像检出27个，比CT多检出的病灶包括食管癌复发，锁骨上、纵隔和肺门淋巴结及骨转移。结论 ^18F-FDG符合线路显像对食管癌术后复发转移的诊断具有较高的临床价值，尤其在临床疑有复发转移而常规影像学检查阴性时有重要意义。     

肺部病变18F-FDG符合线路显像不同参照点半定量值的对比研究

目的 探讨18 F-FDG符合线路显像诊断肺部病变良恶性的最佳半定量阈值.方法 对137例肺部病变患者(男89例,女48例,年龄33 ～ 78岁)行18F-FDG符合线路显像,测量肺部病变(T)、正常胸壁软组织(NT1)及对侧相应肺组织(NT2)的最大放射性.以正常胸壁软组织和对侧相对应肺组织为参照点,分别计算肺部病变半定量摄取比值R1(T/NT1)及R2(T/NT2),应用ROC曲线确定肺部病变良恶性的最佳临界值R1(cutoff)、R2(cutoff),并计算其对应的灵敏度、特异性、准确性.结果 R1(cutoff)取3.58,R2(cutoff)取4.40;按此2个最佳临界值,18F-FDG符合线路显像诊断肺部病变的灵敏度、特异性、准确性分别为90.0％ (90/100)、89.2％ (33/37)、89.8％ (123/137)和90.0％ (90/100)、78.4％(29/37)、86.9％ (119/137).结论 以胸壁软组织为参照点,半定量摄取比值取3.58作为18F-FDG符合线路显像诊断肺部病变良恶性的阈值更可靠.     

孤立性肺病变18F-FDG PET/CT显像诊断价值及误诊原因分析

目的 探讨18F-FDG PET/CT显像对孤立性肺病变的诊断价值及误诊原因.方法 回顾分析32例孤立性肺部病变患者18F-FDG PET/CT显像结果.将PET/CT结果与病理检查结果进行对比,评价18F-FDG PET/CT显像在孤立性肺部病变诊断中的价值,并分析其误诊原因.应用SPSS 16.0软件行统计学分析,SUVmax及SUVmax变化率(△SUVmax)与病灶直径大小关系采用Pearson相关分析.结果 32例孤立性肺部病变中,恶性病变22例,良性病变10例.18F-FDG PET/CT对68.75％( 22/32)患者进行了准确定性诊断.18F-FDG PET/CT显像假阴性5例,假阳性5例.22例肺部恶性病变中,6例恶性病变早期SUVmax ＜2.5,5例恶性病变△SUVmax＜15％.10例肺部良性病变中,2例良性病变早期SUVmax≥2.5,4例良性病变△SUVmax≥15％.良恶性病变SUVmax及△SUVmax有交叉.32例肺部病变中,孤立性肺部病变最大直径≤3 cm共26例,最大直径＞3 cm共6例,平均(1.98±1.08) cm.SUV max与病变直径大小呈正相关(r=0.690,P＜0.01),△SUVmax与病灶直径大小无相关性(r=-0.081,P＞0.05).结论 18F-FDG PET/CT在肺部孤立性病变定性诊断中有重要临床价值,但单纯依靠SUV max存在不足,应将PET与CT综合分析.     

孤立性肺结核球的~(18)F-FDGPET/CT影像学表现

目的：探讨孤立性肺结核球（PTM）的18F-脱氧葡萄糖（FDG）PET/CT影像学表现。方法：回顾性分析23例经病理或临床证实为孤立性PTM患者的18F-FDG PET/CT影像学资料,所有患者均经注射18F-FDG 60min后行螺旋CT平扫和PET显像,分别对PTM进行形态学分析和标准摄取值（SUV）半定量分析。结果：23例病例中,CT平扫显示孤立性PTM直径为1.11~5.10 cm,平均2.48 cm;结节边缘光滑者16例,结节内有空洞者4例、钙化者3例;同时合并纵隔、肺门或腋窝淋巴结增大者6例。本组患者中17例发生18F-FDG摄取,其中11例表现为肺内结节局限性18F-FDG浓聚,6例表现为肺内结节和增大淋巴结18F-FDG浓聚,平均SUVmax为4.01±1.89;12例18F-FDG摄取阳性的患者经抗结核治疗后病灶缩小;6例未发生18F-FDG摄取的患者,经CT随访12个月病灶无明显变化。结论：18F-FDG PET/CT对孤立性PTM的诊断具有重要价值,确诊有赖于穿刺活检或手术病理。     

原发性肺弥漫大B细胞淋巴瘤18F-FDG PET/CT显像一例

笔者报道了一例原发性肺弥漫大B细胞淋巴瘤的18F-FDG PET/CT显像病例,从临床症状、实验室检查、18F-FDG PET/CT影像学等方面分析该病特点,并通过文献回顾了原发性肺弥漫大B细胞淋巴瘤鉴别诊断要点。研究结果显示,本例原发性肺弥漫大B细胞淋巴瘤18F-FDG PET/CT影像学表现为巨大软组织团块影、边缘光滑、内见多发点状钙化灶,18F-FDG代谢团块状增高,SUV_max为26.2。18F-FDG PET/CT显像能够为原发性肺弥漫大B细胞淋巴瘤的诊断提供参考依据。     

18F-FDG PET/CT显像联合HRCT对孤立性原发肺浸润性黏液腺癌的诊断价值

目的探讨孤立性原发肺浸润性黏液腺癌18F-FDG PET/CT显像和HRCT征象及两者联合对该病的诊断价值。方法回顾性分析经病理证实为浸润性黏液腺癌、有18F-FDG PET/CT双时相显像及病灶层面同机HRCT扫描资料的9例患者,对PET/CT早期、延迟显像及滞留指数、HRCT征象进行综合分析。结果HRCT图像上表现为2例呈实性结节、病灶周围无类似卫星灶样影,6例实性结节周围伴小点片及磨玻璃样影,1例为单纯磨玻璃样结节;分叶征(6例)、血管集束征(6例)、支气管充气征(4例)、空泡征(2例)、毛刺征(1例);18F-FDG PET/CT融合图像上8例病灶表现为不均匀FDG代谢增高,早期显像平均SUVmax为3.2±2.5,延迟现象SUVmax增高6例、降低2例,平均SUVmax为3.5±2.4,平均滞留指数为(10.4±29.3)%,9例均未见纵隔、双侧肺门淋巴结及其他部位转移征象,其18F-FDG PET/CT融合图像上18F-FDG摄取与HRCT相匹配,18F-FDG摄取相对集中于结节的实性区域,病灶磨玻璃区18F-FDG摄取不明显;综合手术病理结果等临床资料证实,9例均为T1N0M0期,与PET/CT分期一致。结论对于影像学检查发现肺孤立性占位患者,在单一影像学检查难以明确诊断的情况下,18F-FDG PET/CT双时相显像上病灶不均匀18F-FDG摄取相对集中于其实性区域的代谢方式与HRCT相联合,可辅助孤立性原发性肺浸润性黏液腺癌的诊断。     

Clinical significance of small pulmonary nodules with little or no 18F-FDG uptake on PET/CT images of patients with nonthoracic malignancies.

Small pulmonary nodules with little or no perceptible (18)F-FDG uptake are relatively common findings on combined PET/CT images of patients with nonthoracic malignancies. Interpreting such nodules is often a diagnostic challenge, and this study aimed to evaluate the clinical significance of the nodules. METHODS: Patients with pulmonary nodules < or =1 cm in diameter showing no (18)F-FDG uptake or uptake less than the mediastinal background were included. Nodules with clearly benign or metastatic findings on CT were excluded. One hundred twenty-one patients had either tissue confirmation or clinical follow-up with additional chest images. The subjects were studied by 3 variables: (i) solitary versus multiple nodules, (ii) presence of accompanying benign lung lesion versus absence, and (iii) imperceptible (18)F-FDG uptake versus faint (18)F-FDG uptake. The malignancy rates were calculated for each variable. RESULTS: Of the 121 patients, 24 had malignancy, with a strong possibility of pulmonary metastasis (19.8%). Six of the 44 patients with solitary nodules (13.6%) and 18 of the 77 patients with multiple nodules (23.4%) had malignancies, though there was no statistically significant difference in the incidences of malignancy between the solitary and multiple groups. On the other hand, there was a statistically significant difference (P = 0.040) between the accompanying lung lesion present (8.3%) and absent (24.7%) groups. No statistically significant difference was noted between the (18)F-FDG uptake imperceptible group and faint (18)F-FDG uptake group (20.7% vs. 17.2%). CONCLUSION: For patients with incidental lung nodules of indeterminate nature with no (18)F-FDG uptake or uptake less than that of the mediastinum on PET/CT images, >19% of the cases turned out to be malignant. The nodule was more likely to be malignant when no other benign pulmonary lesions could be identified elsewhere in the lung field. Thus, regardless of the number of nodules and (18)F-FDG uptake, tissue confirmation or close imaging follow-up is necessary when small nodules with imperceptible or faint (18)F-FDG activity are present on the PET/CT images, especially in the absence of accompanying benign lung lesions.     

<Superscript>18</Superscript>p-FDG PET is superior to<Superscript>67</Superscript>Ga SPECT in the staging of non-Hodgkin’s lymphoma

OBJECTIVE: Our study aims to compare diagnostic accuracy between 18F-FDG PET and 67Ga SPECT in the staging of non-Hodgkin's lymphoma. METHODS: Twenty-eight patients with non-Hodgkin's lymphoma, underwent 18F-FDG PET, 67Ga SPECT and CT for the pretreatment staging of malignant lymphoma between August 1999 and March 2002. 18F-FDG PET imaging was obtained 60 minutes after the intravenous administration of 185 MBq of 18F-FDG. 67Ga SPECT imaging was obtained 2 days after the intravenous administration of 148 MBq of 67Ga. 18F-FDG PET and 67Ga SPECT were performed within one month. Both imagings were performed on the area from the neck to the pelvis. The 18F-FDG PET and 67Ga SPECT findings were compared with the CT findings and the clinical course. RESULTS: Sixty-six nodal lesions were clinically confirmed. Of these, 32 were identified by both 18F-FDG PET and 67Ga SPECT. The remaining 34 lesions were identified only by 18F-FDG PET. The mean (+/- SD) sizes' of the nodes were 34.7 +/- 32.4 mm for 18F-FDG-positive and 67Ga-positive lesions and 15.7 +/- 8.3 mm for 18F-FDG-positive and 67Ga-negative lesions (p < 0.001). Of the 23 extranodal lesions, 12 were identified by both 18F-FDG PET and 67Ga SPECT, whereas 6 lesions were identified by only 18F-FDG PET. Five lesions were not identified by either technique. No 18F-FDG-negative but 67Ga-positive nodal or extranodal lesions were observed. The difference in findings between the two studies is related to the difference in the size but not in the histology or site of the lesions. CONCLUSION: 18F-FDG PET detected significantly more lesions particularly small lesions than 67Ga SPECT. Thus, 18F-FDG PET is considered to be superior to 67Ga SPECT in the staging of non-Hodgkin' s lymphoma.     

Nuclear medicine imaging in tuberculosis using commercially available radiopharmaceuticals

In this paper, data available on nuclear medicine imaging using commercially available radiopharmaceuticals for the differentiation, staging, and prediction or assessment of the response to treatment in tuberculosis (TB) are reviewed. Limited available studies suggest that single photon emission computed tomography (SPECT) using either 201Tl, 99mTc-sestamibi, or 99mTc-tetrofosmin is accurate (≥85%) and has a high negative predictive value (≥90%) for the differentiation of TB from carcinoma in patients presenting with a solitary pulmonary nodule (SPN). The criteria for detection of TB on 201Tl SPECT are nondepiction of the suspicious lesion in the delayed image or a negative retention index [washout on the delayed images (3–4 h postinjection) vs. the early image (5–15 min postinjection)] and a comparable-to-background uptake on 99mTc-sestamibi or 99mTc-tetrofosmin SPECT. Another SPECT tracer of potential interest for the differentiation of TB from malignant SPN that warrants further exploration, is N-isopropyl-p-[123I]iodoamphetamine (123I-IMP). In contrast, 18F-fluorodeoxyglucose (18F-FDG) PET is unable to differentiate malignancy from TB and thus cannot be used as a tool to reduce futile biopsy/thoracotomy in these patients. A limited number of studies have reported on the potential of nuclear medicine imaging in assessment of the extent of disease in patients with extrapulmonary TB using 67Ga-citrate SPECT and 18F-FDG PET, respectively. 67Ga-citrate SPECT was shown to be as sensitive as bone scintigraphy for the detection of bone infection and was found to be complementary to computed tomography (CT) imaging. 18F-FDG PET was found to be significantly more efficient when compared with CT, respectively, in over half of patients for the identification of sites of lymph node involvement that were missed by CT and often the only sites of extrapulmonary TB identified. Unfortunately, 18F-FDG PET findings did not lead to alterations in treatment planning in any of the patients under study. Additional studies confirming these findings are urgently required. Similar to the setting of SPN, 18F-FDG PET cannot differentiate malignant lymph node involvement from lymph node involvement by TB. These results and the recent findings of Demura and colleagues using 18F-FDG PET further suggest that nuclear medicine imaging techniques could be used for the evaluation of therapeutic response. Prospective studies, focusing on specific subgroups of patients in whom such an imaging approach might be clinically relevant, for example in multidrug-resistant TB patients, are warranted. In acquired immunodeficiency syndrome patients, 67Ga scintigraphy proved to be a reliable and sensitive method for the primary detection and follow-up of opportunistic pneumonias, including TB. Combining 201Tl scintigraphy with 67Ga scintigraphy was shown to increase the specificity for both pulmonary and extrapulmonary TB, which is a 67Ga(+) and 201Tl(-) mismatch pattern in acquired immunodeficiency syndrome patients that is specific for mycobacterial infections. Finally, the results obtained using both SPECT and PET indicate that nuclear medicine could be an important noninvasive method for the determination of disease activity, detection of extrapulmonary TB, and determination of response to therapy.     

11C-胆碱与18F-FDG双时相PET/CT显像结合高分辨率CT在孤立性肺结节鉴别诊断中的应用

目的比较11C-胆碱（11C-CHO）PET/CT、18F-FDG双时相PET/CT、常规18F-FDG PET/CT、11C-CHO+18F-FDG双时相PET/CT显像结合高分辨率CT（HRCT）4种方法对鉴别诊断孤立性肺结节（SPN）良恶性的价值。方法对28例SPN患者进行18F-FDG PET/CT显像（注药后l h显像,2 h行延迟显像）和11C-CHO PET/CT显像（于注药10 min后进行）。PET图像判断以SPN最大截面勾画ROI,计算SUV_max作为半定量指标,SUV_max ≥ 2.5为阳性,18F-FDG PET/CT延迟显像SUV_max上升10%为恶性病变（阳性）,下降或升高 < 10%为良性病变（阴性）。HRCT以是否有分叶征、短细毛刺、胸膜尾征、支气管充气征、血管集束征、空泡征为分析良恶性的指征。所有病例进行临床综合分析及随访,以影像诊断是否符合临床随访及病理结果作为判断标准。组间SUV_max的比较采用t检验;计数资料的比较采用χ2检验。结果 28例SPN患者中,病理或临床随访诊断发现肺癌17例,结核7例,结节病4例。常规18F-FDG PET/CT显像确诊21例,18F-FDG双时相PET/CT显像确诊24例,11C-CHO PET/CT显像确诊23例,11C-CHO +18F-FDG双时相PET/CT+HRCT确诊27例。28例患者良恶性结节的18F-FDG及11C-CHO PET/CT的SUV_max比较,差异有统计学意义（t=10.57和13.19,均P < 0.05）。良恶性结节分叶、毛刺、胸膜尾征、血管集束征之间的差异有统计学意义（χ2=9.27、10.36、14.31和17.52,均P < 0.05）。11C-CHO+18F-FDG双时相PET/CT+HRCT联合显像的灵敏度为81.8%,特异度为94.1%,准确率为96.4%,明显高于非联合显像。结论 11C-CHO+18F-FDG双时相PET/CT+HRCT能较好地鉴别SPN的良恶性,三者联合能提高对SPN的诊断率。     

Coincidence imaging using 2 dual-head gamma-camera systems, with and without attenuation correction

OBJECTIVE: Coincidence imaging enhances the potential for imaging a greater number of patients with 18F-FDG in centers that do not have dedicated PET systems. The purpose of this study was to compare, in a clinical setting, coincidence imaging for tumor detection using 2 dual-head gamma-camera systems, one equipped with a 5/8-in. (16 mm) detector (CoDe5) and the other equipped with a newly designed 1-in. (25.4 mm) detector (CoDe8) with an x-ray tube installed in its gantry. METHODS: Thirty consecutive patients were studied by both systems during the same visit and had 4 image sets for comparison: CoDe5 without attenuation correction (CoDe5NC), CoDe8 with (CoDe8AC) and without (CoDe8NC) attenuation correction, and fused coincidence-CT images. The target-to-background ratio (T/Bg ratio) and target-to-nontarget ratio (T/NT ratio) were calculated for each tumor site. RESULTS: On visual assessment, 61 tumor sites were detected on CoDe8AC images. Of these, 59 (97%) were detected on CoDe8NC and 54 (88%) were detected on CoDe5NC images. Fused images improved image interpretation in 10 patients (33%) compared with coincidence images alone. Data added by fusion were of clinical relevance in 6 patients (20%). On quantitative assessment, the number of accepted events by the CoDe8 was significantly higher than that by CoDe5 (5.21 +/- 1.46 million vs. 1.27 +/- 0.36 million, P <0.001). When comparing CoDe5 with CoDe8 images without attenuation correction, the T/Bg and T/NT ratios were significantly higher on the CoDe8 images (P <0.0005 and P <0.0005, respectively). When comparing CoDe8 images with and without attenuation correction, the T/Bg ratio was better on the attenuation-corrected images (P <0.0005). CONCLUSION: Coincidence imaging with 1-in. detectors and attenuation correction improve image quality and, to a lesser extent, the tumor detection rate compared with the 5/8-in. detectors and noncorrected images. The data added by fusion of coincidence images to CT findings were clinically relevant in 20% of the patients.