99Tcm-HL91 SPECT肺癌显像研究

目的研究99Tcm-HL91 SPECT肺癌显像与病理类型及病灶大小的关系.方法经病理证实的非小细胞肺癌患者共30例,利用SPECT仪采集注射740MBq99Tcm-HL91后2 h、4 h及6 h的前位、后位及侧位平面图像,利用感兴趣区(ROI)技术分别勾画各时相肿瘤(T)和对侧相应部位(N)ROI,计算T/N比值.患者于HL91 SPECT检查1周内行CT检查,测量CT图像上病灶大小.结果HL91选择性地浓集于肿瘤组织,浓集区域与CT显示肿瘤区域一致.显像清晰,以4 h效果为最佳,2 h、4 h和6 h T/N比值有统计学差异(P=0.041).鳞癌组及腺癌组4 h T/N差异无显著性(P=0.365),病灶大小与T/N无相关关系(P=0.702).结论99Tcm-HL91显像是一项有价值的肺癌检查手段,而与病理类型及病灶大小无相关性.     

Anatomically derived attenuation coefficients for use in quantitative single photon emission tomography studies of the thorax.

Elimination of errors due to poor attenuation correction is an essential part of any quantitative single photon emission tomography (SPET) technique. Attenuation coefficients (mu Tc) for use in attenuation correction of SPET data were determined using technetium 99m and cobalt 57 flood sources and using topographical information obtained from computed tomography (CT) scans and magnetic resonance (MR) images. In patients with carcinoma of the bronchus, the mean attenuation coefficient for 99mTc was 0.096 cm-1 when determined across a transverse section of the thorax at the level of the tumour by means of a 57Co flood source (13 patients) and 0.093 and 0.074 cm-1 as determined from CT scans for points in the centre of the tumour and contralateral normal lung, respectively (21 patients). In 18 patients with breast tumours, the mean attenuation coefficient for 99mTc was 0.110 and 0.076 cm-1 when determined from MRI cross-sections for points in the centre of the tumour and normal contralateral lung, respectively. This indicates significant overcorrection for attenuation when the conventional value of 0.12 cm-1 is used. A value in the range 0.08-0.09 cm-1 would be more appropriate for SPET studies of the thorax. An alternative approach to quantitative region of interest (ROI) analysis is to perform attenuation correction appropriate to the centre of each ROI (using topographical information derived from CT or MRI) on non-attenuation-corrected reconstructions.     

Investigation of the relationship between linear attenuation coefficients and CT Hounsfield units using radionuclides for SPECT

This study has investigated the relationship between linear attenuation coefficients (mu) and Hounsfield units (HUs) for six materials covering the range of values found clinically. Narrow-beam mu values were measured by performing radionuclide transmission scans using (99m)Tc, (123)I, (131)I, (201)Tl and (111)In. The mu values were compared to published data. The relationships between mu and HU were determined. These relationships can be used to convert computed tomography (CT) images to mu-maps for single photon emission computed tomography (SPECT) attenuation correction.     

[<Superscript>99m</Superscript>Tc]Demobesin 1, a novel potent bombesin analogue for GRP receptor-targeted tumour imaging

Demobesin 1 is a potent new GRP-R-selective bombesin (BN) analogue containing an open chain tetraamine chelator for stable technetium-99m binding. Following a convenient labelling protocol, the radiopeptide, [(99m)Tc]Demobesin 1, formed in nearly quantitative yields and with high specific activities. Both unlabelled and labelled peptide demonstrated high-affinity binding in membrane preparations of the human androgen-independent prostate adenocarcinoma PC-3 cell line. The IC(50) values determined for Demobesin 1 and [Tyr(4)]BN were 0.70+/-0.08 n M and 1.5+/-0.20 n M, respectively, while the K(d) defined for [(99m)Tc/(99g)Tc]Demobesin 1 was 0.67+/-0.10 n M. [(99m)Tc]Demobesin 1 was rather stable in murine plasma, whereas it degraded rapidly in kidney and liver homogenates. After injection in healthy Swiss albino mice, [(99m)Tc]Demobesin 1 accumulated very efficiently in the target organs (pancreas, intestinal tract) via a GRP-R-mediated process, as shown by in vivo receptor blocking experiments. An equally high and GRP-R-mediated uptake was exhibited by [(99m)Tc]Demobesin 1 after injection in PC-3 tumour-bearing athymic mice. The initial high radioligand uptake of 16.2+/-3.1%ID/g in the PC-3 xenografts at 1 h p.i. remained at a similar level (15.61+/-1.19%ID/g) at 4 h p.i. Even after 24 h p.i., when the radioactivity had cleared from all other tissues, a value of 5.24+/-0.67%ID/g was still observed in the tumour. The high and prolonged localization of [(99m)Tc]Demobesin 1 at the tumour site and its rapid background clearance are very promising qualities for GRP-R-targeted tumour imaging in man.     

Various imaging modalities for the detection of salivary gland lesions: the advantages of 201Tl SPET

The aim of this study was to compare dual-isotope (99Tc(m) and 201Tl) SPET imaging with computed tomography (CT) and magnetic resonance imaging (MRI) in the differentiation of various lesions of the major salivary glands. Twenty-two patients underwent dual-isotope SPET imaging, of whom 12 also had CT and 15 also had an MRI study. The uptake ratio and retention index for 99Tc(m) and 201Tl were calculated by drawing regions of interest on the involved and normal glands. Both CT and MRI were interpreted by two radiologists. All malignant tumours were detected by all three modalities. Warthin's tumours were detected by dual-isotope SPET imaging; however, MRI failed to differentiate Warthin's tumour from pleomorphic adenoma. Of 13 other benign tumours, dual-isotope SPET correctly diagnosed 12. Of 16 tumours showing a cold defect on the 99Tc(m) images, parametric analysis with 201Tl gave an accuracy of 94%, whereas CT gave an accuracy of 70-90%. MRI was 73-91% accurate in differentiating between benign (Warthin's) and malignant tumours. We believe that dual-isotope SPET imaging (99Tc(m) and 201Tl), together with semi-quantitative analysis, is the method of choice for differentiating between various lesions of the major salivary glands.     

Imaging of HER2/neu expression in BT-474 human breast cancer xenografts in athymic mice using [(99m)Tc]-HYNIC-trastuzumab (Herceptin) Fab fragments

OBJECTIVE: To evaluate the ability of trastuzumab (Herceptin) Fab, labelled with (99m)Tc through introduced hydrazinenicotinamide (HYNIC) functionalities, to image HER2/neu-overexpressing human breast cancer xenografts in athymic mice. METHODS: Fab fragments were produced by immobilized papain digestion of trastuzumab immunoglobulin G (IgG), followed by purification by ultrafiltration. The immunoreactivity of trastuzumab Fab was evaluated by receptor-binding assays against HER2/neu-positive SK-BR-3 human breast cancer cells. Trastuzumab Fab fragments were labelled with (99m)Tc following modification with HYNIC N-hydroxysuccinimide ester. Biodistribution and tumour imaging studies were performed in athymic mice bearing subcutaneous HER2/neu-overexpressing BT-474 human breast cancer xenografts following intravenous injection of 1.1 or 25 MBq of [(99m)Tc]-trastuzumab Fab (30 microg), respectively. The specificity of tumour uptake was assessed by comparison with that of [(99m)Tc]-labelled irrelevant anti-CD33 HuM195 Fab. RESULTS: Trastuzumab Fab was pure and exhibited preserved immunoreactivity towards SK-BR-3 cells (K(d) = 1.6 x 10(-8) M). Modification with HYNIC diminished its receptor-binding affinity fourfold. [(99m)Tc]-trastuzumab Fab localized avidly and specifically in BT-474 xenografts, achieving a tumour uptake of 10.7% of the injected dose (ID) per gram and a tumour to blood (T/B) ratio of 3 : 1 at 24 h. The tumour uptake and T/B ratio for [(99m)Tc]-trastuzumab Fab were significantly higher than those for control [(99m)Tc]-HuM195 Fab (2.6% ID x g(-1) and 0.9 : 1, respectively; P<0.05). Tumours were imaged as early as 2 h post-injection of [(99m)Tc]-trastuzumab Fab, but were more clearly visualized at 6 and 24 h post-injection. CONCLUSIONS: [(99m)Tc]-HYNIC-trastuzumab Fab localized specifically in HER2/neu-overexpressing human breast cancer xenografts in athymic mice, allowing imaging of the tumours within the useful lifetime of the radionuclide.     

Phase 1 study to identify tumour hypoxia in patients with head and neck cancer using technetium-99m BRU 59-21

The aim of this study was to assess the safety and biodistribution of technetium-99m BRU 59-21, a novel radioactively labelled 2-nitro-imidazole hypoxic marker, in head and neck cancer patients and to correlate uptake with pimonidazole staining. (99m)Tc-BRU 59-21 was administered intravenously (mean dose 824 MBq, range 780-857 MBq) to ten head and neck cancer patients scheduled for primary surgery, and whole-body images and SPET scans were then obtained. Uptake of radioactivity in the regions of interest was determined and tumour to normal tissue ratios were calculated after correlative evaluation with MRI/CT. Twelve to 16 h before surgery (up to 2 weeks after the scan), patients received pimonidazole intravenously. Tumour sections were stained immunohistochemically for pimonidazole binding. No serious adverse events were reported. In five patients there were ten adverse events, which were mild in intensity and resolved completely without intervention. Uptake of (99m)Tc-BRU 59-21 was observed in eight of the ten primary tumours. Tumour to normal tissue ratios on the SPET scans for primary tumour and lymph nodes increased from 1.8 (range 0.9-2.7) to 2.1 (range 0.8-3.7) between 30 min and 3 h post injection. Tumour to normal tissue ratios in the primary tumour were significantly correlated with pimonidazole staining for SPET scans performed 30 min and 3 h post injection ( P=0.016 and P=0.037, respectively). When primary tumour and involved lymph nodes were considered in conjunction, correlation between the tumour to normal tissue ratio and pimonidazole staining was observed for early ( P<0.001) but not for late SPET scans ( P=0.076). However, late scans showed better tumour delineation than early scans. Administration of (99m)Tc-BRU 59-21 in head and neck cancer patients appears to be safe and feasible. Uptake and retention in tumour tissue was observed, suggestive of tumour hypoxia, and this was supported by correlations with staining for the hypoxic marker pimonidazole.     

Synthesis,radiochemistry and biological evaluation of a new somatostatin analogue (SDZ 219–387) labelled with technetium-99m

A new derivative of octreotide SDZ 219-387 [PnAO-(D)Phe¹-octreotide] was synthesized, which binds specifically and with high affinity to somatostatin receptors in vitro (pK= 9.79±0.16). This new somatostatin analogue chelates technetium-99m under mild labelling conditions in good yields. The resulting [^99mTc]SDZ 219–387 was stable up to 6 h after labelling and could be isolated in a pure radiochemical and chemical form by high-performance liquid chromatographic purification. The intravenous administration of purified [^99mTc]SDZ 219–387 revealed that the radioligand was rapidly cleared from circulation, and tumour uptake of 0.38% ID/g was observed at 1.5 h post injection. [^99mTc]SDZ 219–387 specifically interacted with somatostatin binding sites on the tumour. However, the radioligand is highly lipophilic and excreted mainly through the hepatobiliary system. As a consequence, [^99mTc]SDZ 219–387 exhibits increased background activity and therefore is not appropriate for the in vivo visualization of somatostatin receptor-positive tumours and/or their metastases in the abdomen. Correspondence to: T. Maina     

Clinical and diagnostic imaging of bisphosphonate-associated osteonecrosis of the jaws

OBJECTIVES: It is important to recognize osteonecrosis of the jaws in patients treated with bisphosphonates because an early diagnosis can make a significant difference to the outcome of the disease. The aim of this study is to describe the radiological features of bisphosphonate osteonecrosis (BON) in order to aid its prompt recognition. METHODS: A conventional radiograph, a computed tomograph (CT), a magnetic resonance image (MRI) and a 99Tc(m)-MDP 3-phase bone scan were carried out for 11 patients with BON. The main imaging findings of osteonecrosis are described. RESULTS: Conventional radiography and CT displayed osteolytic lesions with the involvement of cortical bone. MRI demonstrated the characteristic features of osteonecrosis and the oedema of soft tissues. Both CT and MRI were very useful in defining the extent of the lesions. 99Tc(m)-MDP three-phase bone scan was the most sensitive tool to detect the osteonecrosis at an early stage. CONCLUSIONS: 99Tc(m)-MDP three-phase bone scans who could be used as a screening test to detect subclinical osteonecrosis in patients who have received bisphosphonates. CT scans and MRI are useful in defining the features and extent of osteolytic lesions.     

螺旋CT引导下自动切割针系统在肺活检中的应用价值

目的 研究螺旋CT引导下，采用自动可分离切割针系统经皮穿刺活检的诊断价值。方法 螺旋CT引导，使用自动弹射活检枪、16G～21G可调式同轴切割针，对287例肺内结节性病灶行经皮穿刺肺活检。结果 262例获定性诊断，其中恶性病变195例，良性病变67例，定性诊断率为91.3％，气胸、咯血等轻微并发症为21.3％。结论 螺旋CT引导下自动可分离切割针系统是一种安全、准确、有效的肺球形病灶检查方法，值得临床推广。     

99mTc(V)DMSA quantitatively predicts 188Re(V)DMSA distribution in patients with prostate cancer metastatic to bone

Rhenium-188 dimercaptosuccinic acid complex [¹⁸⁸Re(V)DMSA], a potential therapeutic analogue of the tumour imaging agent ^99mTc(V)DMSA, is selectively taken up in bone metastases in patients with prostate cancer. It would be helpful in planning palliative radionuclide therapy if ^99mTc(V)DMSA could be used to predict tumour and kidney retention of ¹⁸⁸Re(V)DMSA. The aim of this study was to determine the correlation between tumour-to-normal tissue ratios and kidney-to-soft tissue ratios of ^99mTc(V)DMSA and ¹⁸⁸Re(V)DMSA. This would determine whether a scan with ^99mTc(V)DMSA could be used to identify patients for whom ¹⁸⁸Re(V)DMSA treatment would be contra-indicated, and enable prediction of relative kidney and tumour radiation absorbed dose in ¹⁸⁸Re(V)DMSA treatment. Ten patients with prostate carcinoma were recruited following observation of disseminated bone metastases on a recent ^99mTc-hydroxydiphosphonate bone scan. Whole-body planar scans were obtained at ca. 4 h and 24 h after hydration and injection of 600 MBq ^99mTc(V)DMSA, and a week later, at similar times after hydration and injection of 370 MBq ¹⁸⁸Re(V)DMSA. A triple-energy window (TEW) scatter correction was applied to the ¹⁸⁸Re scans. Counts per pixel were determined in regions of interest drawn over metastatic sites, kidneys and normal soft tissue. Tumour-to-soft tissue ratios were significantly lower (by a factor of approximately 0.8 after the TEW was applied) on ¹⁸⁸Re scans than on ^99mTc scans, but the two were highly linearly correlated both in all individual patients and in tumours pooled from all patients together both at 4 h and at 24 h. Kidney-to-soft tissue ratios were similarly correlated and were lower for ¹⁸⁸Re than for ^99mTc by a similar factor. Both tumour- and kidney-to-soft tissue ratios increased between 4 and 24 h but the latter increased more. In conclusion, only minor differences were seen between ^99mTc and ¹⁸⁸Re scans, and kidney-to-background ratios on ¹⁸⁸Re scans were not higher than on ^99mTc scans. These differences are insufficient to infer that they are due to a real difference in biodistribution, and they may be due only to different physical imaging characteristics. Thus ^99mTc(V)DMSA scans are predictive of ¹⁸⁸Re(V)DMSA biodistribution and could be used to estimate tumour and renal dosimetry and assess suitability of patients for ¹⁸⁸Re(V)DMSA treatment.     

Expression of permeability-glycoprotein (P-gp) and uptake of technetium-99m-hexakis-2-methoxy-isobutyl-isonitrile (99Tcm-MIBI) in malignant tumour of the head and neck

OBJECTIVES: The purpose of this study is to estimate the role of permeability-glycoprotein (P-gp) in the technetium-99m-hexakis-2-methoxy-isobutyl-isonitrile (99Tc(m)-MIBI) scintigraphy. METHODS: 71 patients with squamous cell carcinoma (39 patients with well differentiated, 19 with moderately differentiated and 13 with poorly differentiated tumour) were examined. Eighteen of these patients underwent 99Tc(m)-MIBI scintigraphy (early and delayed scans). The tumour retention index, obtained from the ratio of the accumulation of the delayed scan to that of the early scan, was divided into three groups. The immunohistochemical evaluation of P-gp expression was performed in all 71 patients. Levels of the P-gp expression were classified into three grades (score 0, 1 and 2). Correlations among the tumour retention index, the P-gp expression and the tumour tissue differentiation were evaluated. RESULTS: 17 of 18 patients showed a decreasing of the tumour retention index ranging from 0.70 to 0.93 (mean+/-SD=0.850+/-0.071). The tumour retention index showed a statistical correlation with the P-gp expression and the tumour tissue differentiation (chi-squared=7.802>7.779, P=0.10 and 16.835>14.860, P=0.005, respectively). Moreover, there was a statistical correlation between the P-gp expression and the tumour tissue differentiation (chi-squared=14.863>14.860, P=0.005). CONCLUSION: There is a possibility that the P-gp expression is high in the high-grade malignant tumours and P-gp causes the decrease of tumour retention index.     

99Tc(m)(V)DMSA scintigraphy in skeletal metastases and superscans arising from various malignancies: diagnosis, treatment monitoring and therapeutic implications

Skeletal metastases arising from a wide variety of malignancies including a few cases with superscan appearance were evaluated using (99)Tc(m) MDP bone scanning and (99)Tc(m)(V)DMSA scintigraphy. Whole body planar scans were obtained at 3 h and 24 h after injection of 740 MBq (99)Tc(m) MDP and 5 days later at similar times after injection of 555 MBq of (99)Tc(m)(V)DMSA. A qualitative as well as quantitative comparison was made between the (99)Tc(m) MDP bone scan and the (99)Tc(m)(V)DMSA scan in detection of osseous metastases. The reference methods used for discordant or equivocal lesions were correlative morphological imaging modalities, for example additional conventional radiography, CT or MRI. The present pictorial review deals with the results of qualitative analysis of the study. A total of 75 cases have been evaluated. The vignettes illustrated in the present article demonstrate avid (99)Tc(m)(V)DMSA concentration in skeletal metastases from a wide variety of malignancies and thus expand the potential therapeutic indications for 188/186 Re(V)DMSA. The study also demonstrates the valuable supporting role a (99)Tc(m)(V)DMSA scan can play in the confirmation as well as evaluation of the extent of malignant infiltration in a suspected superscan in routine skeletal scintigraphy. In addition, a (99)Tc(m)(V)DMSA scan detected a number of metastatic lesions in and around joints and regions with previous surgical intervention that were inconclusive in the bone scan. The results in a few patients who were available for repeat scintigraphy following treatment, support the convincing evidence that (99)Tc(m)(V)DMSA accumulation may be a sensitive indicator of patient response to therapy. This might have an important bearing in the context of increasing "cold" bisphosphonate usage in the treatment of skeletal metastases, where skeletal scintigraphy with a radiolabelled bisphosphonate derivative can often be fallacious because of competitive inhibition by the non-labelled form.     

99Tcm-HL91显像、CT和血清肿瘤标志物测定联合应用诊断肺癌

目的探讨Tc^m-4，9-二氮．3，3，10，10-四甲基十二烷-2，11-二酮肟(HL91)显像、CT、血清肿瘤标志物[癌胚抗原(CEA)、细胞角蛋白19片断(CYFRA21-1)、神经元特异性烯醇酶(NSE)]测定联合应用对肺癌的诊断价值。方法46例疑为肺癌患者在1周内进行^99Tc^m-HL91 SPECT显像、CT检查和血清肿瘤标志物测定。计算每种方法及三法联合应用诊断肺癌的灵敏度、特异性及准确性。结果最终经病理检查或细胞学诊断证实肺癌26例，经病理检查或治疗后影像学随访确诊肺部良性病变20例。^99Tc^m-HL91 SPECT显像、CT及血清肿瘤标志物测定诊断肺癌的灵敏度、特异性及准确性分别为77％、80％、78％，96％、60％、80％及50％、60％、54％。三法联合应用诊断肺癌的灵敏度、特异性及准确性分别为100％、90％、96％，其综合诊断效能明显优于其中任何一种检查方法。结论^99Tc^m-HL91显像、CT、血清肿瘤标志物测定联合应用在肺部肿瘤良恶性鉴别诊断中有较大价值。     

Scintigraphy for interpretation of malignant tumours of the head and neck: comparison of technetium-99m-hexakis-2-methoxyisobutylisonitrile (Tc-MIBI) and thallium-201-chloride (Tl-201)

OBJECTIVES: The purpose of this study was to compare the usefulness of technetium-99m-hexakis-2-methoxyisobutylisonitrile (99Tc(m)-MIBI) and thallium-201-chloride (Tl-201) as scintigraphic agents. METHODS: Dynamic and static scintigraphic imaging with 99Tc(m)-MIBI and Tl-201 were performed on patients with a variety of malignant and benign tumours. Factors of the grade of the static scan, the blood flow index, the early and delayed retention indexes, and the tumour retention index were obtained from the scintigraphy. In addition to these factors, the grade of tissue differentiation and tumour size were evaluated to clarify the difference between 99Tc(m)-MIBI and Tl-201 for the diagnosis of malignant tumours of the head and neck. RESULTS: 99Tc(m)-MIBI accumulation depended upon the blood flow index in the early static scan, but this accumulation did not correlate with tumour size. The accumulation in most subjects decreased in the delayed static scan, and the tumour retention index had a tendency to decrease with the grade of tissue differentiation. Tl-201 accumulation depended upon the blood flow index in the early static scan similar to 99Tc(m)-MIBI, and the accumulation correlated with tumour size, unlike 99Tc(m)-MIBI. The tumour retention index had a tendency to increase with the grade of tissue differentiation. Thus, the tumour retention indexes showed opposite behaviours between 99Tc(m)-MIBI and Tl-201, but they both accurately determined tumour malignancy. CONCLUSIONS: There was no major difference between 99Tc(m)-MIBI and Tl-201scintigraphy with respect to accuracy of diagnosis of malignant tumours of the head and neck. However, 99Tc(m)-MIBI was superior to Tl-201 for small-size tumours and Tl-201 was useful for large-size tumours.     

Protein-losing enteropathy: diagnosis with (99m)Tc-labeled human serum albumin scintigraphy

PURPOSE: To investigate the diagnostic value of technetium 99m-labeled human serum albumin (HSA) scintigraphy in a group of patients suspected of having protein-losing enteropathy (PLE). MATERIALS AND METHODS: After intravenous injection of 740 MBq of freshly prepared (99m)Tc HSA, serial images of the abdomen were obtained from 10 minutes until 24 hours after injection. A (99m)Tc HSA scan was considered positive for PLE if there was visible tracer exudation in the gut. The diagnosis was established on the basis of standard clinical and biopsy findings. RESULTS: Thirty-nine scans were obtained: 27 scans in 26 suspected cases of PLE and 12 scans in control subjects with no known gastrointestinal disease. Twenty-five of the 26 studies in patients suspected of having PLE showed (99m)Tc HSA activity in the bowel. Among the 25 studies with positive findings, seven demonstrated PLE only on images obtained 24 hours after injection. In the control subjects, no activity was seen in the bowel. CONCLUSION: (99m)Tc HSA with serial scanning for up to 24 hours is reliable and useful for imaging PLE. Sites of protein loss may also be demonstrated. This imaging method is convenient, easy to perform, and yields results within 24 hours.     

Clinically suspected pulmonary embolism: utility of spiral CT

PURPOSE: To prospectively determine the utility of contrast material-enhanced spiral computed tomography (CT) in the examination of patients clinically suspected of having pulmonary embolism (PE). MATERIALS AND METHODS: One hundred ten patients clinically suspected of having PE were examined with contrast-enhanced spinal CT and at least one other imaging modality: ventilation-perfusion scintigraphy, Doppler ultrasonography of deep leg veins, or pulmonary angiography. Chart review or telephone contact with the referring clinician was used to evaluate the contribution of spiral CT to the final clinical diagnosis. RESULTS: Spiral CT helped correctly identify 23 of 25 patients with PE (sensitivity, 92%). In 57 (67%) of the 85 patients without PE, spiral CT provided additional information that suggested or confirmed the alternate clinical diagnosis: pneumonia (n = 14), cardiovascular disease (n = 10), pulmonary fibrosis (n = 7), trauma (n = 6), malignancy (n = 5), pleural disease (n = 4), postoperative changes (n = 4), and other (n = 7). In the remaining 28 patients, spiral CT scans were normal (n = 12), failed to produce findings supportive of the final clinical diagnosis (n = 13), or were false-positive for PE (n = 3; specificity, 96%). CONCLUSION: Spiral CT has good sensitivity and specificity for the diagnosis of PE. In the majority of patients who do not have PE, it also provides important ancillary information for the final diagnosis.     

Multiplanar spiral CT enterography in patients with Crohn's disease using a negative oral contrast material: initial results of a noninvasive imaging approach

The aim of this study was to prospectively define the role of multiplanar spiral CT enterography with a new negative oral contrast material for noninvasive assessment of the small bowel in patients with Crohn's disease. Thirty patients with established Crohn's disease prospectively underwent spiral CT enterography at 45-60 min after distension of the small bowel with 1400 ml of a negative oral contrast material (Mucofalk water enema). Spiral CT scans were obtained 50 s after administration of intravenous contrast material with the following parameters: 5-mm collimation; 7.5-mm/s table feed; and 3-mm reconstruction interval. The adequacy of bowel opacification, luminal distension, and the contribution of two-dimensional multiplanar reformatted imaging were assessed by two observers. Spiral CT imaging findings were compared with results of enteroclysis as well as endoscopic and histological findings in all patients. Spiral CT enterography with Mucofalk water enema was well tolerated in 29 of 30 patients. Findings on spiral CT enterography were comparable with those of barium studies in 25 of 30 patients, superior to those on barium studies in 4 patients, and inferior in 1 patient ( p<0.05). The addition of multiplanar reformatted images to axial spiral CT scans significantly improved observers' confidence in image interpretation ( p<0.05) but did not reveal additional abnormalities. Multiplanar spiral CT enterography with Mucofalk excellently provides information in patients with Crohn's disease. This technique accurately depicts the level of small bowel obstruction and the extent of inflammatory small bowel disease and its extraluminal complications.     

Detection of head and neck cancer with 99Tc(m) glutathione: a correlative study with tissue glutathione and glutathione S-transferase levels

In this study glutathione (GSH), a natural tripeptide which plays an important role in detoxification reactions, protecting cells against damage from xenobiotics, has been labelled with 99Tc(m) for the demonstration of head and neck cancer. Twenty-eight patients (10 females and 18 males) with various malignancies of the head and neck were given 740 MBq of 99Tc(m)-GSH intravenously and single-photon emission computed tomography (SPECT) images were obtained at 3 h. Semiquantification was performed by drawing regions of interest on three consecutive transaxial slices and tumour to background ratios were calculated. In addition, GSH and glutathione S-transferase (GST) levels were measured in the tumour samples and in normal tissue which were obtained during surgery. Scintigraphic images showed that there was increased uptake in the tumour compared to the normal contralateral side (tumour/normal tissue (mean +/- SD) = 1.94 +/- 0.76). The tissue analyses revealed increased levels of GST in tumour tissues, but both GST and GSH levels in tumour were not statistically different from those in the normal tissue. We conclude that scintigraphic visualization of head and neck tumours can be attributed to increased demand for GSH in cancer. Protein binding might account for the prolonged retention of 99Tc(m)-GSH in the malignant tissue. Like other peptides, it is accumulated and excreted by the kidneys, which allows clear visualization of the abdomen without interference from gastrointestinal system activity.     

99Tcm-tetrofosmin在乳腺癌及其转移灶显像中的应用

99Tcm-tetrofosmin作为亲肿瘤显像剂,对乳腺癌原发病灶和腋窝淋巴结转移的诊断有良好的灵敏度、特异性和准确率,可应用于乳腺癌全身骨转移和术后复发的诊断,其应用于乳腺癌前哨淋巴结转移的诊断、作为P-糖蛋白功能显像剂和三维立体定位引导孔针型活检等领域有着良好的发展前景.99Tcm-tetrofosmin乳腺癌及转移灶显像可与其他乳腺癌检查方法相结合提高乳腺癌诊断的准确率.