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Objective:To explore whether the specific synaptic vesicle glycoprotein 2A (SV2A) targeted imaging agent ( R)-4-(3-fluoro-5-(fluoro- 18F)phenyl)-1-((3-methylpyridin-4-yl)methyl)pyrrolidin-2-one ( 18F-SDM-8) can be used to detect epileptic foci. Methods:Twenty male Sprague-Dawley (SD) rats (8-9 weeks) were injected with 1.2 μl of kainic acid (16 rats in the epilepsy group) or saline (4 rats in the control group) into the right hippocampus. 18F-SDM-8 and 18F-FDG mircoPET/CT imaging were respectively performed at 1-2 d (acute phase), 6-7 d (incubation period) and 45-60 d (chronic phase) after the seizure. Asymmetric index (AI) was used to evaluate the epileptic foci identify ability of 18F-SDM-8. Paired t test, Mann-Whitney U test and Pearson correlation analysis were used to analyze data. Results:In the three periods of 18F-SDM-8 imaging, the differences of AI of hippocampus between the epilepsy group and control group were statistically significant ( z values: from -2.64 to 2.67, all P<0.05). Both imaging agents had asymmetric uptake in the epilepsy group (right was lower than left), and the decrease in the medial right temporal lobe was the most significant. The pathological staining results were consistent with the imaging results. In the chronic phase of the epilepsy group, the differences of 18F-SDM-8 SUV mean (right versus left) in each brain area of interest were statistically significant ( t value: from -33.40 to -5.60, all P<0.05). The asymmetric uptake of the two imaging agents in the hippocampus had a better correlation ( r=0.97, P=0.001), and the AI of 18F-SDM-8 ((34.2±8.4)%) in this area was 1.4 times higher than that of 18F-FDG ((24.6±4.7)%). Conclusions:18F-SDM-8 PET is a promising method to test the level of SV2A. It can reflect the changes of SV2A in the rat epilepsy model induced by intrahippocampal injection of kainic acid, and improve the sensitivity of molecular imaging for epileptic foci.
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Objective:To explore the added value of time-activity curve (TAC) and target-to-background ratio (TBR) obtained by 18F-FDG total-body PET/CT dynamic imaging in the diagnosis of liver malignant tumors. Methods:From December 2019 to October 2021, 109 patients (65 males, 44 females; age (59.3±9.3) years) with hepatocellular carcinoma (HCC; n=27), intrahepatic cholangiocarcinoma (ICC; n=61) and colorectal cancer with liver metastasis (CRLM; n=21) who underwent 60 min 18F-FDG total-body PET/CT dynamic imaging in Zhongshan Hospital, Fudan University were retrospectively enrolled. Dynamic PET/CT images were divided into perfusion-weighted (PW) phase and metabolism-weighted (MW) phase. The arterial phase was defined as the 15 s after the abdominal aorta peak frame at PW. TACs at MW were divided into three types as Graph A, Graph B and Graph C. One-way analysis of variance was used to compare difference of TBR 30/60 among groups. ROC curve analysis was used to evaluate diagnostic effectiveness. Results:With hypervascularity as the diagnostic standard of HCC, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 66.7%(18/27), 75.6%(59/78), 48.6%(18/37) and 86.8%(59/68), respectively. With Graph B as the diagnostic standard of HCC, the sensitivity, specificity, PPV and NPV were 44.4%(12/27), 85.4%(70/82), 50.0%(12/24) and 82.4%(70/85), respectively. The TBR 30/60 of HCC, ICC and CRLM was 0.38±0.19, 0.49±0.18 and 0.64±0.20 respectively ( F=10.89, P<0.001). When the cut-off value of TBR 30/60 was 0.43, the AUC of distinguishing HCC from ICC and CRLM was 0.72, with the sensitivity and specificity of 70.5%(55/78) and 65.2%(15/23). When the cut-off value of TBR 30/60 was 0.64, the AUC of distinguishing ICC from CRLM was 0.71, with the sensitivity and specificity of 61.9%(13/21) and 82.5%(47/57). Conclusion:TAC graph types and TBR 30/60 obtained by total-body PET/CT dynamic imaging display potential value for differentiation between hepatic tumor types.
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Objective:To explore the effect of dietary intake before fasting on the physiological distribution of 18F-FDG PET/CT, and to improve the 18F-FDG PET/CT image quality. Methods:From August 2019 to May 2020, questionnaire of dietary intake before fasting of 118 patients (73 males, 45 females; age (58.4±13.4) years) who performed PET/CT imaging in Zhongshan Hospital, Fudan University were retrospectively analyzed. The total dietary energy intake, the nutrient intake and energy supply ratio of the three energy source nutrients, the type of raw materials and the texture of diet were included. The SUV max and SUV mean of the liver, mediastinal blood pool and hip muscles were measured. Single-factor and multi-factors linear regression analyses were used to analyze data. Results:The fasting blood glucose of 118 subjects was (5.36±1.01) mmol/L. The texture of diet before fasting were general diet, semiliquid diet and liquid diet, which were 42 (35.59%), 72 (61.02%) and 4 (3.39%) subjects, respectively. The energy supply ratios of carbohydrate, protein and fat were (55.46±18.27)%, (16.70±7.38)% and (27.72±14.53)%, respectively. The results of multi-factors regression analysis indicted that protein energy ratio was an independent factor influencing SUV max ( β=0.005, P=0.031) and SUV mean ( β=0.003, P=0.042) of the hip muscles, and the texture of diet was an independent factor influencing SUV max ( β=0.126, P=0.030) and SUV mean ( β=0.197, P=0.002) of mediastinal blood pool. Conclusions:The dietary intake before fasting has significant effect on the imaging quality of 18F-FDG. The protein energy ratio is an independent factor influencing SUV max and SUV mean of the hip muscles. The texture of diet is an independent factor influencing SUV max and SUV mean of mediastinal blood pool.
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Objective:To investigate the value of total-body PET/CT 2 h imaging with half-dose 18F-FDG in the detection of active lesions of Takayasu arteritis (TA). Methods:Fifty-five patients with TA(13 males, 42 females, age: (34.3±13.9) years), who accepted 2 h total-body 18F-FDG PET/CT scan with half-dose activity in Zhongshan Hospital, Fudan University between January 2020 and June 2021, were retrospectively enrolled. TA was diagnosed according to the American College of Rheumatology (ACR) criteria. Patients were categorized into active TA group and inactive TA group based on the National Institutes of Health (NIH) criteria. Lesions with SUV max≥(liver SUV max- 0.1) were defined as active lesions. If multiple lesions occurred in one artery segment, only the lesion with the highest SUV max was chosen. Lesion-to-blood SUV max ratio was calculated. The independent-sample t test or Mann-Whitney U test was used to analyze the liver SUV max, blood pool SUV max and lesion-to-blood ratio between those 2 groups. Results:A total of 363 active lesions were found in 39 patients with active TA and 137 lesions were found in 16 patients with inactive TA. The liver SUV max (1.93±0.45 vs 1.95±0.35; t=0.20, P=0.846) and blood pool SUV max (0.75(0.63, 0.98) vs 0.90(0.77, 1.01); z=-1.45, P=0.148) of patients with active and those with inactive TA were not significantly different. The lesion-to-blood ratio in active TA group was higher than that in inactive TA group (3.09(2.36, 4.24) vs 2.57(2.24, 3.25); z=4.05, P<0.001). Conclusions:Total-body PET/CT 2 h imaging has qualified lesion-to-blood ratio in TA imaging. Inflammatory lesions of vascular wall can be detected sensitively in both patients with active TA and those with inactive TA.
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Comparing to the conventional PET/CT, the advantage of total-body PET/CT lies in the long axial field-of-view (LAFOV) which improves the system sensitivity by 40 times, allowing rapid scan, low-dosing imaging and total-body dynamic imaging. Total-body PET/CT can increase the throughput of patients, reduce the radiation dose, and observe the drug metabolism in vivo both real-time and dynamically. Its high sensitivity makes long-time delay scan possible in clinic research. Besides, it also has potential advantages in drugs development and in the field of pharmacokinetic researches.
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18F-fluorodeoxyglucose(FDG) PET/MR has been more and more widely used in non-small cell lung cancer (NSCLC). Compared with PET/CT, PET/MR has more advantages, such as higher contrast resolution of soft tissues, less radiation dose and providing physicians with more functional parameters. This article summarizes the application status of 18F-FDG PET/MR in NSCLC in terms of diagnosis, staging, restaging, and prognosis.
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Objective:To screen 89Zr-labeled anti-epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) monoclonal antibody molecular probes suitable for monitoring the gastric mucinous adenocarcinoma bearing mouse models with low glucose metabolism. Methods:The expression of EGFR and HER2 in the MGC803 gastric cancer cell line was verified by analyzing cell slides and xenograft tumor sections. 89Zr-Deferoxamine (DFO)-Cetuximab and 89Zr-DFO-Pertuzumab were prepared and the radiochemical purity was detected. Cell binding experiments and blocking experiments were performed to verify the binding ability and specificity of the probes. Twelve gastric mucinous adenocarcinoma bearing mouse models were divided into 3 groups ( n=4 in each group): 89Zr-DFO-Cetuximab group (7.4 MBq/mouse, 74 μg/mouse), 89Zr-DFO-Pertuzumab group (7.4 MBq/mouse, 70 μg/mouse) and 18F-fluorodeoxyglucose (FDG) group (7.4 MBq/mouse). MicroPET imaging was performed at 4, 24 and 48 h ( 18F-FDG group underwent imaging at 1 h only) post-injection. The biodistribution study of 89Zr-DFO-Cetuximab and 89Zr-DFO-Pertuzumab was conducted in 2 groups ( n=4 in each group) 48 h after the injection. The independent sample t test was used for data analysis. Results:The immunofluorescent staining demonstrated EGFR expression was significantly higher than HER2 expression in MGC803 gastric cancer cell line. The radiochemical purity of 89Zr-DFO-Cetuximab and 89Zr-DFO-Pertuzumab were both more than 95%, and the specific activities were 100 and 95 MBq/mg, respectively. The two probes had good stability in normal saline and fetal bovine serum, with the radiochemical purity higher than 80% at 72 h. MicroPET imaging showed that the uptake of 89Zr-DFO-Cetuximab in the MGC803 tumor was significantly higher than that of 18F-FDG and 89Zr-DFO-Pertuzumab. The biodistribution study demonstrated the 89Zr-DFO-Cetuximab uptake (percentage activity of injection dose per gram of tissue, %ID/g) of tumors at 48 h was significantly higher than that of 89Zr-DFO-Pertuzumab (56.3±12.0 vs 22.0±3.6; t=4.31, P<0.05). Conclusion:Compared with 89Zr-DFO-Pertuzumab, 89Zr-DFO-Cetuximab has a better potential for non-invasive monitoring of gastric mucinous adenocarcinoma with low glucose metabolism.
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Objective:To explore the advantage of three-phase bone scintigraphy combined with SPECT/CT over three-phase bone scintigraphy in the differential diagnosis of periprosthetic infection from prosthesis loosening in patients after prosthesis replacement.Methods:Seventy patients (27 males, 43 females, age (69.5±10.5) years) who were suspected with prosthesis loosening or periprosthetic infection underwent 99Tc m-methylene diphosphonate (MDP) three-phase bone scintigraphy and SPECT/CT from October 2008 to November 2019 in Zhongshan Hospital, Fudan University were retrospectively reviewed. All patients had pathological diagnoses based on surgical resection or lesion biopsy. The diagnostic efficiency of three-phase bone scintigraphy images and three-phase bone scintigraphy combined with SPECT/CT were evaluated. χ2 test was used for data analysis. Results:Among 70 patients, 34(48.6%, 34/70) were diagnosed as periprosthetic infection and 36(51.4%, 36/70) were diagnosed as prosthesis loosening. Using three-phase bone scintigraphy for the differential diagnosis of bone lesions, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 94.1%(32/34), 77.8%(28/36), 85.7%(60/70), 80.0%(32/40) and 93.3%(28/30), when combined with SPECT/CT, the corresponding results were 94.1%(32/34), 94.4%(34/36), 94.3%(66/70), 94.1%(32/34), 94.4%(34/36), respectively. The specificity and accuracy were increased ( χ2 values: 4.167, 4.167, both P=0.031). Conclusion:Combination of three-phase bone scintigraphy with SPECT/CT can provide added value over three-phase bone scintigraphy for differential diagnosis in patients with periprosthetic loosening or periprosthetic infection.
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Objective:To explore the imaging features of 18F-fluorodeoxyglucose (FDG) PET/CT (high-resolution CT, HRCT) imaging in focal organizing pneumonia (FOP). Methods:Patients with solid nodular FOP ( n=45; 33 males, 12 females, age (58±9) years) and early peripheral non-mucinous solid lung adenocarcinoma ( n=47; 21 males, 26 females, age (63±10) years) confirmed by postsurgical pathology between May 2012 and December 2018 in Zhongshan Hospital, Fudan University were retrospectively analyzed. All patients underwent 18F-FDG PET/CT (HRCT) imaging followed by surgery within 3 weeks. The imaging findings and characteristics of the lesions were recorded. Differences of the maximum standardized uptake value (SUV max) and maximum diameter between FOP and adenocarcinoma were analyzed by Mann-Whitney U test or t′ test. Spearman correlation or Pearson correlation analysis was performed to analyze the relation between SUV max and maximum diameter. Binary logistic regression analysis was performed to identify the predictive factors for FOP. Finally, the receiver operating characteristic (ROC) curve analysis was used for evaluation of diagnostic efficiency. Results:The SUV max of FOP was lower than that of lung adenocarcinoma (3.1(1.7, 4.9) vs 6.5(3.8, 9.3); z=-4.598, P<0.01), and the maximum diameter of FOP was smaller than that of lung adenocarcinoma ((18.0±6.3) mm vs (21.8±4.3) mm; t′=-3.424, P<0.01). The SUV max was positively correlated with the maximum diameter in FOP group ( r s=0.509, P<0.01), while the SUV max of lung adenocarcinoma was not correlated with the lesion size ( r=0.076, P>0.05). HRCT of the PET/CT system showed the fusiform shape were more common in FOP ( χ2=9.549, P<0.05). Multivariate regression analysis identified that SUV max≤7.1, diameter≤18.3 mm, and fusiform shape were independent factors to predict FOP, with odds ratio ( OR) of 10.585, 4.674, 9.073, respectively (all P<0.05). ROC curve analysis showed that the area under the curve (AUC) of SUV max≤7.1 combined with diameter≤18.3 mm and fusiform nodule was 0.860, and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 97.8%(44/45), 70.2%(33/47), 75.9%(44/58), 97.1%(33/34), and 83.7%(77/92), respectively. Conclusion:SUV max≤ 7.1 combined with maximum diameter≤ 18.3 mm and fusiform shape may predict solid nodular FOP.
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Objective@#To investigate the incremental value of coronary flow reserve (CFR) assessed by cadmium zinc telluride(CZT)-SPECT as an adjunct to myocardial perfusion imaging (MPI) in the diagnosis of coronary artery disease (CAD).@*Methods@#Data of 132 patients (89 males, 43 females; 40-81 years) with or suspected with CAD who successfully underwent rest and stress MPI and CFR from November 2017 to October 2018 in Zhongshan Hospital Affiliated to Fudan University were retrospectively analyzed. Based on coronary angiography (CAG) as the " gold standard" , the value of MPI and MPI+ CFR in the diagnosis of CAD was evaluated and compared. χ2 test or Fisher exact probability test was used for data analysis.@*Results@#Of 132 patients, 61 (46.2%) were CAD with stenosis of at least 75% in one vessel (47.5%, 29/61), two vessels (34.4%, 21/61), or three vessels (18.0%, 11/61). A total of 104 (26.3%) vessels with stenosis of at least 75%, 25 (6.3%) vessels with stenosis of 65%-74%, and 30 (7.6%) vessels with stenosis of 50%-64% were found in 396 vessels. For detecting coronary stenosis of at least 75%, the sensitivity and accuracy of MPI on per-patient analysis were 86.89%(53/61) and 68.94%(91/132), which increased to 96.72%(59/61; χ2=3.921, P<0.05) and 87.88%(116/132; χ2=13.984, P<0.01) by MPI+ CFR. On per-vessel analysis, the sensitivity and accuracy of MPI were 72.12%(75/104) and 77.53%(307/396) and increased to 96.15%(100/104; χ2=22.511, P<0.01) and 85.10%(337/396; χ2=7.479, P<0.05) by MPI+ CFR. The sensitivity of MPI for predicting one, two, and three vessels disease were 72.41%(21/29), 42.86%(9/21), and 5/11 and were improved to 93.10%(27/29; χ2=4.350, P=0.037), 90.48%(19/21; χ2=10.714, P=0.001), and 11/11 (P=0.012) by MPI+ CFR. For coronary with stenosis of 65%-74%, the sensitivity of MPI was 24.00%(6/25) and was improved to 64.00%(16/25; χ2=8.117, P=0.004) by MPI+ CFR. For coronary with stenosis of 50%-64%, the sensitivity of MPI was 40.00%(12/30) and was improved to 76.67%(23/30; χ2=8.297, P=0.004) by MPI+ CFR.@*Conclusion@#As an adjunct to MPI, CFR can significantly improve the sensitivity and accuracy in the diagnosis of CAD, particularly for patients with mild stenosis and multivessel CAD.
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Atherosclerotic vulnerable plaques may cause acute cardiovascular events.Matrix metalloproteinase (MMP) plays an important role in the pathological process of high-risk plaques.It degrades the extracellular matrix of atherosclerotic plaque,thus making the fibrous cap thinner and the plaque more vulnerable,which lead to rupture.MMP inhibitors (MMPI) can specially bind MMP and inhibit its activity.Taking MMP as the target,nuclear medical imaging can identify and evaluate the unstable plaque in molecular level,and can also be used to explore the biological characteristics of plaque,as well as to monitor drug efficiency.This review summarizes the development of nuclide targeted MMPI in atherosclerotic plaque imaging.
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18F-fluorodeoxyglucose (FDG) PET/CT offers excellent diagnostic performance on colorectal cancer liver metastases(CRCLM) in terms of sensitivity and specificity, and can comprehensively identify the presence of extrahepatic metastases and provide valuable information for the treatment decision making. 18F-FDG PET/CT can also be used in the early assessment of response to CRCLM therapy and survival prediction. However, the diagnostic value of PET/CT is limited for lesions with diameter within 10 mm or with activity inhibited strongly by chemotherapy. PET combined with contrast enhanced CT may have potential value in improving diagnostic sensitivity for CRCLM.
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18F-fluorodeoxyglucose (FDG) PET/CT offers excellent diagnostic performance on color-ectal cancer liver metastases( CRCLM) in terms of sensitivity and specificity, and can comprehensively identi-fy the presence of extrahepatic metastases and provide valuable information for the treatment decision making. 18 F-FDG PET/CT can also be used in the early assessment of response to CRCLM therapy and survival pre-diction. However, the diagnostic value of PET/CT is limited for lesions with diameter within 10 mm or with activity inhibited strongly by chemotherapy. PET combined with contrast enhanced CT may have potential value in improving diagnostic sensitivity for CRCLM.
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Objective To investigate the incremental value of coronary flow reserve ( CFR) as-sessed by cadmium zinc telluride(CZT)-SPECT as an adjunct to myocardial perfusion imaging (MPI) in the diagnosis of coronary artery disease (CAD). Methods Data of 132 patients (89 males, 43 females; 40-81 years) with or suspected with CAD who successfully underwent rest and stress MPI and CFR from November 2017 to October 2018 in Zhongshan Hospital Affiliated to Fudan University were retrospectively analyzed. Based on coronary angiography (CAG) as the " gold standard" , the value of MPI and MPI+CFR in the di-agnosis of CAD was evaluated and compared. χ2 test or Fisher exact probability test was used for data analy-sis. Results Of 132 patients, 61 (46.2％) were CAD with stenosis of at least 75％ in one vessel (47.5％, 29/ 61), two vessels (34.4％, 21/ 61), or three vessels (18.0％, 11/ 61). A total of 104 (26.3％) vessels with stenosis of at least 75％, 25 (6.3％) vessels with stenosis of 65％-74％, and 30 (7.6％) vessels with stenosis of 50％-64％ were found in 396 vessels. For detecting coronary stenosis of at least 75％, the sensi-tivity and accuracy of MPI on per-patient analysis were 86.89％(53/ 61) and 68.94％(91/ 132), which in-creased to 96.72％(59/ 61; χ2 = 3.921, P<0.05) and 87.88％(116/ 132; χ2 = 13.984, P<0.01) by MPI+CFR. On per-vessel analysis, the sensitivity and accuracy of MPI were 72.12％ (75/ 104) and 77. 53％(307/ 396) and increased to 96.15％(100/ 104; χ2 = 22. 511, P<0.01) and 85.10％(337/ 396; χ2 = 7.479, P<0.05) by MPI+CFR. The sensitivity of MPI for predicting one, two, and three vessels disease were 72. 41％(21/ 29), 42.86％ (9/ 21), and 5/ 11 and were improved to 93.10％ (27/ 29; χ2 = 4.350, P =0. 037), 90.48％(19/ 21; χ2 = 10.714, P = 0.001), and 11/ 11 (P = 0.012) by MPI+CFR. For coronary with stenosis of 65％-74％, the sensitivity of MPI was 24. 00％(6/ 25) and was improved to 64.00％(16/25; χ2 = 8.117, P= 0.004) by MPI+CFR. For coronary with stenosis of 50％-64％, the sensitivity of MPI was 40.00％(12/ 30) and was improved to 76.67％(23/ 30; χ2 = 8.297, P= 0.004) by MPI+CFR. Conclu-sion As an adjunct to MPI, CFR can significantly improve the sensitivity and accuracy in the diagnosis of CAD, particularly for patients with mild stenosis and multivessel CAD.
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Due to untypical clinical manifestations, difficulty of diagnosis and treatment, and poor prognosis, the early and accurate diagnosis of cardiovascular infection is very important. 18F-fluorodeoxyglucose (FDG) PET/ CT has been widely applied in the diagnosis of infection. This article reviews the role of 18F-FDG PET/ CT in the diagnosis and treatment of cardiovascular infection, such as infectious endocarditis, cardiac implantable electronic device infection, and vascular prosthetic graft infection.
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Objective To evaluate the combined impacts of blood glucose and its related metabolic factors on 18F-FDG uptake by liver.Methods A total of 544 subjects (384 males and 160 females, age range 24-73 years) undergoing 18F-FDG PET/CT were recruited in this retrospective study.SUVmean of the right lobe of liver was calculated.Two-sample t test and one-way analysis of variance were performed to compare SUVmean between patients with different genders and BMI levels.Linear correlation analysis, partial correlation analysis and multiple linear regression analysis were conducted to evaluate the relationship between age, injected 18F-FDG dose, blood glucose, serum T3, T4, FT3, FT4, BMR, BMI and liver SUVmean.Results The SUVmean of the liver in males and females were 1.89±0.42 and 1.92±0.38 (t=0.693, P>0.05), but it was significantly different among BMI groups (F=3.056, P<0.05).Age, blood glucose and FT3 were significantly associated with liver SUVmean (r′ values: 0.108, 0.140 and 0.105, all P<0.05) and were independent factors that indicated variation of liver SUVmean (β values: 0.006, 0.070 and 0.088, all P<0.05).Blood glucose was the strongest powerful predicting variable of liver SUVmean (β′=0.154, P<0.001).Conclusions Blood glucose and its related metabolic factors can affect the liver 18F-FDG uptake.Age, FT3, blood glucose are independent factors predicting variation of liver SUVmean.The impact of glucose metabolism status should be considered when assessing liver 18F-FDG uptake.
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Objective To explore the imaging characteristics and diagnostic value of 18 F-FDG PET/CT in patients with hepatic epithelioid hemangioendothelioma ( HEH) . Methods From January 2014 to December 2015, 5 HEH patients (2 males, 3 females; average age (49.2±13.7) years) confirmed by pathology and underwent 18 F-FDG PET/CT imaging were enrolled in this retrospective study. The character-istics of PET/CT images were analyzed. Two-sample t test and Pearson linear correlation analysis were used for data analysis. Results A total of 26 lesions were detected in 4 patients with multiple lesions, of which 88.5%( 23/26) distributed at the liver edge, and 42. 3%( 11/26) had hepatic capsule retraction sign. SUVmax of the 26 lesions was 5.1±2.6 and it was not correlated with tumor size (r=0.054, P>0.05). Lesion FDG uptake in patients with distant metastases was higher than that in patients without distant metastases (6.08±1.80 vs 3.84±1.14;t=4.15, P<0.05). Two patients underwent the delayed imaging, and FDG up-take in 11/14 lesions was higher compared with that of early imaging, and 3/14 lesions were newly detected by the delayed imaging. One patient had diffuse low-density lesions with diameters between 6.1 and 35.5 mm and SUVmax between 2.6 and 8.1. Conclusion Liver lesions of HEH patients show some features on 18F-FDG PET/CT images which can find distant metastases, and the delayed imaging can improve the detection rate of lesions.
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Objective To investigate the capability of 99 Tcm?tricine?EDDA/HYNIC?SFSIIHTPILPL ( SP94) as a specific probe for HCC imaging. Methods HYNIC?SP94 peptide was prepared by solid phase synthesis, followed by 99 Tcm labeling with tricine?EDDA as the coligand. After determination of radiochemical purity and stability, cell binding study was carried out by incubating Huh?7 cells with 99 Tcm?tricine?EDDA/HYNIC?SP94 at different specific activities (2.5, 4.0 and 30.0 GBq/μmol). The biodistribution studies and microSPECT/CT imaging were performed in Huh?7 tumor?bearing mice ( study group) and Hela tumor?bear?ing mice ( control group ) . Statistical analysis was by two?sample t test. Results 99 Tcm?tricine?EDDA/HYNIC?SP94 was synthesized with over 95% of labeling yield, which remained stable in saline and FBS up to 12 h. With increasing concentrations of 99 Tcm?tricine?EDDA/HYNIC?SP94, Huh?7 cell binding increased but became gradually saturated. In biodistribution studies, (1.02±0.26) %ID/g of tracer was accumulated in Huh?7 tumors at 0.5 h after injection of 99 Tcm?tricine?EDDA/HYNIC?SP94, higher than that in the HYNIC?SP94 blocking group ((0.34±0.09) %ID/g;t=3.537, P<0.05). Compared to Hela tumors, Huh?7 tumors were clearly visualized by microSPECT/CT, with which better imaging quality could be achieved with higher specific radioactivity. Conclusion 99 Tcm?tricine?EDDA/HYNIC?SP94 could achieve a high labeling effi?ciency and good in vitro stability as a potential diagnostic tracer specifically targeted for HCC.
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Objective To investigate the added value of CTAC for improving image quality and diagnostic efficiency of bone imaging in SPECT/CT.Methods Seventy-five patients (47 males,28 females,(56.6± 12.8) years) with abnormal uptake in planar whole-body bone scintigraphy underwent SPECT/CTfor differentiation of malignant from benign spinal lesions.NAC and CTAC SPECT images were classified based on 5-point scale (5:excellent,4:good,3:adequate,2:suboptimal,1:inadequate).The diagnostic confidence for both NAC and CTAC SPECT images were classified based on 4-point scale (4:definite,3:certain,2:equivocal,1:uninterpretable).The pathological results after surgery were used as gold standard to evaluate the added diagnostic value of CTAC for spinal lesions.Wilcoxon-signed rank sum test was used for data analysis.Results CTAC improved the image quality in 37.3％ (28/75) of patients,and downgraded in 2.7％ (2/75) of patients.The remaining 45 patients were unchanged (60.0％,45/75).SPECT with CTAC could significantly improve the image quality (z=-4.747,P＜0.001),but the overall diagnostic confidence was not increased (z=-1.000,P＞0.05).Conclusion CTAC can improve the image quality of spinal SPECT,especially useful in imaging with poorer quality,but it has no significant incremental value in diagnostic confidence.
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Atherosclerosis is a vascular inflammatory disease.Vulnerable atherosclerotic plaques mainly lead to severe cardiovascular and cerebrovascular diseases,such as myocardial infarction and stroke.The research on the early diagnosis of vulnerable plaques becomes currently urgent.As a noninvasive molecular modality,the nuclear medicine imaging (with specific radiolabeled probes) has been used for the detection of unstable plaques,and for the evaluation of therapeutic effect of anti-atherosclerotic drugs.Nuclear imaging techniques for detecting metabolic activity,inflammation,hypoxia,angiogenesis,apoptosis,and microcalcification in unstable plaques are summarized in this review.