Presurgical identification of epileptic foci with iodine-123 iomazenil SPET: Comparison with brain perfusion SPET and FDG PET

Iodine-123 iomazenil (IMZ) has excellent characteristics for the quantification of central benzodiazepine receptor (BZR) binding with single-photon emission tomography (SPET). In order to evaluate the clinical value of IMZ SPET for presurgical identification of epileptic foci in patients with medically intractable seizures, we measured the binding potential (BP) of BZR using two IMZ SPET scans and compared the results with brain perfusion SPET and fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET). A total of ten patients with intractable partial epilepsy were examined by electroencephalography, magnetic resonance imaging, FDG PET, brain perfusion SPET and IMZ SPET. After neuroimaging examinations, five patients underwent selective surgery, and all of them have since been free of seizures. Two SPET scans were performed at 15 min (early) and 3 h (late) after intravenous injection of¹²³I-IMZ (167 MBq). Parametric images of the ligand transport (K ₁) and binding potential (BP) were calculated by the table look-up method, which is based on a three-compartment two-parameter model, using the standard arterial input function obtained by averaging of six normal volunteers' input functions. BP images delineated the epileptic foci more precisely than either FDG PET or ictal perfusion SPET. FDG PET showed widespread reduction, including the area surrounding the focus, and ictal increase in the cerebral blood flow was seen in possibly activated areas spread from the focus. In four epilepsy cases which originated from the mesial temporal lobe without lateral temporal abnormality, there was no significant decrease in the BP images in the lateral temporal structures, which showed decreased uptake of FDG. It is concluded that parametric images of BP with IMZ are valuable for precise presurgical localization of epileptic foci.     

Presurgical identification of epileptic foci with iodine-123 iomazenil SPET: comparison with brain perfusion SPET and FDG PET

. Iodine-123 iomazenil (IMZ) has excellent characteristics for the quantification of central benzodiazepine receptor (BZR) binding with single-photon emission tomography (SPET). In order to evaluate the clinical value of IMZ SPET for presurgical identification of epileptic foci in patients with medically intractable seizures, we measured the binding potential (BP) of BZR using two IMZ SPET scans and compared the results with brain perfusion SPET and fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET). A total of ten patients with intractable partial epilepsy were examined by electroencephalography, magnetic resonance imaging, FDG PET, brain perfusion SPET and IMZ SPET. After neuroimaging examinations, five patients underwent selective surgery, and all of them have since been free of seizures. Two SPET scans were performed at 15rmin (early) and 3rh (late) after intravenous injection of ¹²³I-IMZ (167rMBq). Parametric images of the ligand transport (K1) and binding potential (BP) were calculated by the table look-up method, which is based on a three-compartment two-parameter model, using the standard arterial input function obtained by averaging of six normal volunteers’ input functions. BP images delineated the epileptic foci more precisely than either FDG PET or ictal perfusion SPET. FDG PET showed widespread reduction, including the area surrounding the focus, and ictal increase in the cerebral blood flow was seen in possibly activated areas spread from the focus. In four epilepsy cases which originated from the mesial temporal lobe without lateral temporal abnormality, there was no significant decrease in the BP images in the lateral temporal structures, which showed decreased uptake of FDG. It is concluded that parametric images of BP with IMZ are valuable for precise presurgical localization of epileptic foci.     

The utility of a 3-dimensional, large-field-of-view, sodium iodide crystal--based PET scanner in the presurgical evaluation of partial epilepsy.

(18)F-FDG PET is an accurate and reliable technique for localizing medically refractory temporal lobe epilepsy, but widespread use has been hindered by limited reimbursement in many countries because of the high cost of traditional PET equipment and radioisotopes. Additionally, the place of FDG PET as a cost-effective tool for presurgical evaluation of epilepsy has been questioned because of limited data showing that FDG PET provides localization information incremental to that provided by more established techniques, particularly MRI and ictal electroencephalography (EEG). Three-dimensional (3D), large-field-of-view, sodium iodide crystal-based scanners have lower equipment and running costs and better multiplanar resolution than traditional 2-dimensional bismuth germinate (BGO) systems but have not yet been validated for evaluation of epilepsy. Our purpose was to investigate the localization rate, accuracy, and prognostic value of FDG PET images acquired on a 3D, large-field-of-view, sodium iodide crystal-based PET scanner in the presurgical evaluation of intractable partial epilepsy. We also wanted to establish the incremental value of FDG PET over established MRI and ictal EEG techniques. METHODS: Fifty-five patients who were surgical candidates because of medically refractory partial epilepsy were examined. For most of these patients, the lesions had not been clearly localized on conventional assessment. The FDG PET scans were reviewed independently by 2 reviewers who were unaware of the patients' clinical details, ictal EEG findings, and volumetric MRI results, and the FDG PET results were correlated with those of MRI and EEG and with postsurgical outcome. RESULTS: Forty-two patients (76%) had localizing FDG PET images (37 temporal, 5 extratemporal). The ictal EEG recordings were localizing in 66%, and the MRI findings were localizing in 27% (which increased to 35% after the MRI findings were reviewed again after PET). Concordance between the site of the PET localizations and the site of the MRI or EEG localizations was 100%. The PET images were localizing in 63% and 69% of patients with nonlocalizing ictal EEG and MRI findings, respectively. Twenty-one of 24 patients who subsequently underwent epilepsy surgery had localizing FDG PET images; of these 21 patients, 18 (86%) had a class I outcome. Multiple regression analysis showed the FDG PET results to be predictive of postsurgical outcome independently of the MRI findings. CONCLUSION: For intractable partial epilepsy, FDG PET using a 3D, large-field-of-view, sodium iodide crystal-based scanner provided clinically useful localizing information that was at least as accurate as the results reported for traditional BGO-based scanners. The PET images provided prognostically significant localization information incremental to that provided by volumetric MRI and ictal EEG, particularly if 1 of these studies was nonlocalizing.     

发作间期PET显像与发作期SPECT显像在癫痫灶定位中的应用

目的：探讨发作间期PET显像与发作期SPECT显像在癫痫灶定位中的特点和相关性。方法：对54例癫痫患者行发作间期PET和发作期SPECT2次检查,对结果进行对比分析。结果：54例发作间期PET显像示低代谢者中33例（61．1％）表现为单叶局限性低代谢,21例（38．9％）表现为多个病灶或弥漫性改变。发作期SPECT显像50例可见高灌注灶,高灌注中37例（74％）为单叶局限性高灌注,13例（26％）为多个病灶,未见弥漫性高灌注。2项检查比较,46例（85．2％）2项检查结果相符合,其中32例（69．6％）显示为颞叶病灶。发作间期PET示多病灶及弥漫性改变者于发作期SPECT为像时为9例（42．9％）转化为单叶局限性病灶,7例（33．3％）排除了部分低代谢病灶。结论：癫痫灶灌注与代谢改变具有明显的相关性。发作间期PET显像定位癫痫灶解剖结构显示较为清晰,发作期SPECT显像替代发作期PET检查可提高定位特异。2项检查联合应用可排除非致痫性病变和发作过程中痫性电活动的泛化,具有较好的互补性。     

癫痫发作期与发作间期脑血流灌注显像减影法定位致痫灶的价值

目的:研究癫痫发作期与发作间期脑血流灌注显像减影法定位致癫灶的价值.材料和方法:14例癫痫患者在癫痫发作期和发作间期分别进行脑血流灌注显像,两次所得图像进行空间匹配后相减得到减影像,并与EEG、MRI、手术结果及临床表现比较.结果:与发作间期相比,13/14例发作期局部脑血流有不同程度的增高,减影像可显示血流改变的具体部位及形态;1例发作期血流低于发作间期,但病灶区表现明显.手术后病灶病理诊断包括胶质细胞增生、疤痕组织及胶质细胞瘤.术后13例患者发作次数明显减少,1例效果不显著.结论:发作期与发作间期显像减影法定位致痫灶有较高的准确性,有助于术前制定合理的手术方案.     

美解眠介入脑血流显像对癫痫病灶的定位研究

目的：研究美解眠介入SPECT脑血流显像对癫痫病灶的定位。材料和方法：将药物诱发脑电图技术与^99mTc—ECD SPECT脑血流显像相结合建立美解眠介入亚临床发作脑血流显像并对14例局限性癫痫患者(8例经外科手术切除癫痫病灶)进行了发作间期和亚临床发作期脑血流显像比较研究．结果：亚临床发作期癫痫病灶脑血流平均较间期增加12．65%．10／14例增加超过5%，8／14例增加超过10%．最多增加超过31%．图像比较以亚临床发作期病灶血流出现反转和填充较有意义．结论：本方法可克服发作期显像不易及时注入显像剂的缺陷。     

F-18 fluoro deoxyglucose SPECT for assessment of myocardial viability

Identification of myocardial viability in hypokinetic segments is important in patients with ischemic cardiomyopathy because systolic dysfunction improves with revascularization. Positron emission tomography (PET) F-18 fluoro deoxyglucose (FDG) uptake has been demonstrated as an accurate indicator of metabolically active and thus viable myocardium. F-18 FDG single photon emission computed tomography (SPECT) has recently been introduced and offers a technically easier and less costly alternative to PET imaging for determination of myocardial viability. A body of literature demonstrates that F-18 FDG SPECT can reliably be performed with SPECT hardware equipped with 511-keV collimators, which provides an accurate assessment of myocardial viability. F-18 FDG SPECT offers data similar to those offered by F-18 FDG PET and compares favorably with other imaging modalities, including rest-redistribution and stress-reinjection thallium-201 myocardial perfusion imaging, gated technetium 99m SPECT, and low-dose dobutamine echocardiography.     

脑灌注显像定位致痫灶与皮层脑电图、术中和病理所见比较

目的：探讨SPECT脑灌注显像定位致痫灶的价值。方法：选择拟手术治疗的药物难治性部分性癫痫和其他癫痫患者23例，在发作间期和发作期分别进行SPECT脑灌注显像，用皮层脑电图（EcoG)手术和术后病理检查进行验证。结果：用EcoG探查SPECT显示病灶区，23例皆存在典型的尖慢波和棘尖波发放，发作期的局灶性放射性增高区和EcoG所示的异常电话动范围更匹配。痫波起源于相应区域的大脑皮层，而不是增厚和粘连蛛网膜或肿瘤本身，结论：SPECT脑灌注显像有助于识别致痫灶的位置，大小，血运和功能状态，对术前制定治疗方案有一定的指导作用。     

发作间期SPECT对难治性颞叶癫痫的诊断价值

目的:探讨难治性颞叶癫痫(TLE)单光子发射计算机断层(SPECT)的影像特征及定位诊断价值.方法:选择35例经临床手术证实的难治性TLE,术前均行发作间期SPECT脑血流灌注显像和常规MRI扫描.以临床定位结果做对照,观察难治性TLE的SPECT影像改变,分析发作间期脑血流灌注显像定位诊断颞叶致痫灶的临床应用价值.结果:难治性颞叶癫痫SPECT的影像特征为致痫灶侧前颞叶内侧和/或外侧皮质的血流灌注减低,对侧前颞叶的内侧皮质可出现轻度的灌注减低.常合并与患侧同侧的一处或以上脑区的灌注减低.SPECT致痫灶定位诊断的阳性率达77.14％00(27/35),尤其能检出52.94％ (9/17) MRI阴性TLE的致痫灶.结论:发作间期SPECT脑血流灌注显像能丰富难治性TLE的定位诊断信息,提高定位MRI阴性TLE患者致痫灶的比例.     

46例癫痫患者发作间期~(18)F-FDG PET显像结果分析

目的　探讨18F 脱氧葡萄糖 (FDG)PET对发作间期癫痫灶的诊断价值。方法　 4 6例癫痫患者于发作间期进行CT和 (或 )MRI、头皮EEG及18F FDGPET检查。结果　 4 6例患者中 86 95 %(40例 )PET显像有异常代谢灶 ,其中低代谢灶 3 1例 ,高代谢灶 9例。而CT和 (或 )MRI仅 5 6 5 2 % (2 6例 )异常 ,EEG 82 60 % (3 8例 )异常。 9例示局限性高代谢区患者 1周后在确认检查前后 12h均未发作的前提下再次行PET检查 ,结果发现其中 7例同一部位出现低代谢区 ,另 2例代谢也有所降低。结论　18F FDGPET对发作间期癫痫灶的诊断价值明显优于CT和 (或 )MRI和头皮EEG ,尤其在发作间期和发作期各检查 1次 ,或延长发作后检查时间 ,可提高灵敏度和特异性及诊断准确性。     

顽固性癫痫发作间期PET/CT的显像研究

目的探讨顽固性癫痫患者在发作间期PET／CT显像对癫痫灶定位的诊断价值,以指导手术治疗。资料与方法对28例顽固性癫痫患者,行发作间期的^18F—FDG PET／CT显像。对其中的21例癫痫灶较局限的患者行癫痫灶或颞前叶切除,术中行皮层脑电图（ECoG）或深部脑电图（DEEG）描记,以检测其特异性,术后进行随访。结果28例顽固性癫痫患者中,经PET／CT显像有25例显示出低代谢灶,敏感性为89．3％（25／28）。21例手术患者经随访1年以上,癫痫发作消失者18例。结论PET／CT脑显像对癫痫患者的术前定位具有重要价值。     

18F-FDGPET/CT脑显像在癫发作期及发作间期致灶定位中的应用价值

 目的探讨¹⁸F-FDGPET/CT脑3D显像在癫发作期和发作间期致灶定位中的应用价值。方法癫患者60例均行24h头皮脑电图、MRI、¹⁸F-FDGPET/CT脑显像。25例行皮质脑电图(ECoG)或深部脑电图(DEEG)。PET/CT图像经过目测和半定量的方法进行分析。结果(1)60例中,¹⁸F-FDGPET/CT脑显像阳性者57例,检出率95%,其中患者处于发作间期56例,PET/CT表现为低代谢灶者53例,发作期4例,PET/CT上均表现为高代谢灶。(2)PET/CT显示80%为单发灶(48/60),15%为2个以上病灶(9/60)。单发灶中,66.7%位于颞叶(32/48),另33.3%位于颞叶外皮质(顶叶6例,额叶10例)。(3)PET/CT与皮质脑电图(ECoG)或深部脑电图(DEEG)符合率为96%(24/25)。(4)32例颞叶癫行前颞叶切除术,术后随访结果EngelⅠ～Ⅱ级者30例。非颞叶癫16例,行致灶皮质切除术,12例达EngelⅠ～Ⅱ级。3例未检出致灶,9例DEEG定位双侧致灶未行手术治疗。结论对于颅内有病灶癫及明确的颞叶癫患者,PET/CT与EEG以及MRI检查结果具有高度一致性;对于没有病灶及非颞叶癫患者,PET/CT是一种无创、敏感、有效的定位癫源灶的方法。     

Pre-surgical identification of epileptogenic areas in temporal lobe epilepsy by 123I-iomazenil SPECT: a comparison with IMP SPECT and FDG PET

OBJECTIVES: The aim of this study was to evaluate the usefulness of (123)I-iomazenil (IMZ) single photon emission computed tomography (SPECT) for the pre-surgical identification of epileptogenic areas in patients with temporal lobe epilepsy and to compare the results with those of (123)I-IMP SPECT and (18)Fluorodeoxyglucose positron emission tomography (FDG PET). METHODS: We examined seven patients with medically refractory temporal lobe epilepsy (five men and two women; mean age, 28 years) with no remarkable findings on magnetic resonance imaging. Before surgery, IMZ SPECT, IMP SPECT and FDG PET were all performed in the interictal state. Then, visual assessment and region-of-interest (ROI) analysis were performed on each image. Final definitions of the epileptogenic areas were made by electrocorticography and histopathology. RESULTS: By IMZ SPECT, a decreased IMZ uptake in the ipsilateral temporal lobe was found in all patients, while a similar decrease in the contralateral temporal lobe was also found in one patient. In comparison to IMP SPECT, the extent of the abnormal area on IMZ SPECT was equal to that on IMP SPECT in one patient while it was more restricted to the epileptogenic area in five patients. In comparison to FDG PET, the extent of the abnormal area on IMZ SPECT was equal to that on FDG PET in three patients while it was more restricted in the epileptogenic area in four patients. In ROI analysis, decreases of IMZ, IMP and FDG uptake were observed in the epileptogenic area, although they were not statistically significant. CONCLUSIONS: IMZ SPECT was considered to be useful for pre-surgical determination of the epileptogenic areas in temporal lobe epilepsy with no remarkable MRI findings, and it was also found to be superior to IMP SPECT and FDG PET for this purpose.     

18F-FDGPET定位致痫灶在癫痫外科治疗中的价值

目的：评价^18F-脱氧葡萄糖（FDG）PET定位致痫灶在癫痫外科治疗中的作用。方法：对30例难治性癫痫患者行EEG,MRI,PET检查,根据PET检查结果并参考EEG,MRI选择外科治疗方法（开颅手术,X刀治疗,立体定向手术）。开颅手术者,术中行皮层脑电图（ECoG）检查,术后送病理检查。所有患者均观察术后疗效。结果：致痫灶位于颞叶22例,颞叶外6例,额颞区2例,30例患者中16例。30例患者中16例行开颅手术,10例X刀治疗,4例立体定向手术。术后除2例癫痫发作无明显改善外,余28例发作明显减少或消失。结论：^18F-FDG PET检查术前定位致痫灶有助于选择手术方式,提高手术治疗效果。     

Tc-99m ethyl cysteinate dimer SPECT and 2-[F-18]fluoro-2-deoxy-D-glucose PET in Alzheimer's disease. Comparison of perfusion and metabolic patterns.

PURPOSE: This study compared Tc-99m ethyl cysteinate dimer (ECD) SPECT images with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG) PET images in the same patients with Alzheimer's disease and determined whether ECD SPECT is as useful as FDG PET clinically. METHODS: Ten patients with probable Alzheimer's disease (mean +/- SD: age, 71 +/- 5.2 years; 6 women and 4 men; Mini-Mental State Examination score, 19.2 +/- 5.3) were evaluated in this study. Both ECD SPECT and FDG PET were performed within 1.5 months in each patient. RESULTS: ECD SPECT showed a reduction in parieto-temporal perfusion in 8 of the 10 patients, whereas FDG PET showed a reduction in temporoparietal metabolism in 9. The ECD images showed greater radiotracer uptake in the cerebellum and occipital lobe than did FDG images. The contrast between the radiotracer uptake in the sensorimotor area and that in the parietotemporal region was not as great in the ECD images as it was in the FDG images. CONCLUSION: Although ECD SPECT may not be superior to FDG PET, it is useful for the clinical evaluation of patients with Alzheimer's disease.     

MRI-based correction for partial-volume effect improves detectability of intractable epileptogenic foci on 123I-iomazenil brain SPECT images.

(123)I-Iomazenil brain SPECT has been used for the detection of epileptogenic foci, especially when surgical intervention is considered. Although epileptogenic foci exhibit a decrease in (123)I-iomazenil accumulation, normal cerebral cortices often exhibit similar findings because of thin cortical ribbons, gray matter atrophy, or pathologic brain structures. In the present study, we created (123)I-iomazenil SPECT images corrected for gray matter volume using MRI and tested whether the detectability of the epileptogenic foci improved. METHODS: Seven patients (1 male patient and 6 female patients; mean age +/- SD, 34 +/- 17 y) with intractable epilepsy were surgically treated by resecting the cerebral cortex after surface electroencephalography. Histopathologic examination of the resected specimens and a good outcome after surgery indicated that the resected lesions were epileptogenic foci. These patients underwent (123)I-iomazenil SPECT and 3-dimensional T1-weighted MRI examinations before their operations. Each SPECT image was coregistered to the corresponding MR image, and its partial-volume effect (PVE) was corrected on a voxel-by-voxel basis with a smoothed gray matter distribution image. Four nuclear medicine physicians visually evaluated the (123)I-iomazenil SPECT images with and without the PVE correction. The SPECT count ratio of the suspected focus to the contralateral cerebral cortex was evaluated as an asymmetry index (%) based on the volume of interest. RESULTS: The sensitivity, specificity, and accuracy of focus detection by visual assessment were higher after PVE correction (88%, 99%, and 98%, respectively) than before correction (50%, 92%, and 87%, respectively). The mean asymmetry index for the surgically resected lesions was significantly higher on the PVE-corrected SPECT images (22%) than on the PVE-uncorrected ones (16%) (P = 0.006). CONCLUSION: MRI-based PVE correction for (123)I-iomazenil brain SPECT improves the sensitivity and specificity of the detection of cortical epileptogenic foci in patients with intractable epilepsy.     

F-18 Fluorodeoxyglucose PET/CT and Post Hoc PET/MRI in a Case of Primary Meningeal Melanomatosis

Primary meningeal melanomatosis is a rare, aggressive variant of primary malignant melanoma of the central nervous system, which arises from melanocytes within the leptomeninges and carries a poor prognosis. We report a case of primary meningeal melanomatosis in a 17-year-old man, which was diagnosed with ¹⁸F-fluorodeoxyglucose (F-18 FDG) PET/CT, and post hoc F-18 FDG PET/MRI fusion images. Whole-body F-18 FDG PET/CT was helpful in ruling out the extracranial origin of melanoma lesions, and in assessing the therapeutic response. Post hoc PET/MRI fusion images facilitated the correlation between PET and MRI images and demonstrated the hypermetabolic lesions more accurately than the unenhanced PET/CT images. Whole body F-18 FDG PET/CT and post hoc PET/MRI images might help clinicians determine the best therapeutic strategy for patients with primary meningeal melanomatosis.     

Combined C-11 methionine and F-18 FDG PET imaging in a case of neurosarcoidosis

PURPOSE: PET scanning of the brain with F-18 FDG and C-11 methionine (MET) is useful for characterizing brain lesions discovered at MRI or CT. Most positive PET scans indicate malignancy. However, this case report demonstrates positive F-18 FDG and C-11 MET PET scans in a patient with a nonmalignant condition, neurosarcoidosis. MATERIALS AND METHODS: We detail the history and evaluation of a 59-year-old woman who presented with ataxia. The patient's evaluation included a contrast-enhanced MRI followed by PET scanning of the brain with C-11 MET and of the brain and trunk with F-18 FDG. The patient subsequently underwent biopsy of a lesion as directed by MRI and PET. RESULTS: The MRI demonstrated multiple enhancing leptomeningeal lesions consistent with metastatic disease. PET with F-18 FDG and C-11 MET demonstrated lesions in both cerebellar hemispheres with F-18 FDG accumulation in the mediastinum and left hilum. Biopsy of a brain lesion directed by MRI and PET revealed sarcoidosis. CONCLUSIONS: In evaluating brain lesions, PET with F-18 FDG and C-11 MET can help localize the lesion best suited for biopsy. However, not all lesions that have increased uptake on C-11 MET or F-18 FDG PET are malignant. Granulomatous inflammatory diseases such as neurosarcoidosis should also be considered in the differential diagnosis.     

符合线路SPECT在消化系统肿瘤术后复发转移中的应用研究

探讨18F-FDG符合线路SPECT在消化系统肿瘤术后复发转移中的临床应用价值.材料和方法:对35例临床怀疑复发转移的消化系统肿瘤术后患者行18F-FDG符合线路SPECT显像,对其显像结果进行分析,计算其诊断的准确率、灵敏度、特异性、阳性预测值、阴性预测值及其95%可信区间,并与B超、CT、MRI的诊断结果相比较.结果:在35例消化系统肿瘤术后患者中,其诊断的准确率、灵敏度、特异性、阳性预测值、阴性预测值分别为91.4%、88.9%、100%、100%、72.7%;其95%可信区间分别为77%～98%、71%～98%、63%～100%、86%～100%、39%～94%.符合线路SPECT的诊断准确率、灵敏度明显高于B超,与CT和MRI的比较尚无显著性差异;95%可信区间分析,结果显示符合线路SPECT高于B超、CT和MRI;18F-FDG符合线路SPECT和B超、CT、MRI联合应用在某些病例的诊断中具有互补性.结论:18F-FDG SPECT/PET显像在消化系统肿瘤术后复发转移的诊断中具有较高的临床应用价值.     

Fusion images of Tl-201 SPECT and FDG PET with CT in detection of cervical carcinoma with bladder invasion

Thallium-201 single-photon emission computed tomography (Tl-201 SPECT) and F-18 fluorodeoxyglucose positron emission tomography (FDG PET) are accurate and excellent methods for detecting malignant tumors and related metabolic abnormalities. However, there are still some limitations in clinical application. The major limitation of SPECT is poor image resolution. PET is less sensitive for detecting lesions of the urinary system adjacent to the bladder because of bladder radioactivity. Both T1-201 and F-18 FDG PET often provide less information than x-ray computed tomography (CT) about the anatomic landmarks needed to precisely locate lesions. Recent development of multimodality image registration and fusion has been shown to be an excellent tool to resolve these drawbacks. The authors present a rare case of residual cervical carcinoma with bladder invasion, which was detected by fusion imaging of Tl-201 SPECT and FDG PET with CT. This noninvasive image technique may become a valuable alternative to identify bladder invasion in cervical cancer.