Primary Hepatic Gastrointestinal Stromal Tumor on 18 F-FDG PET/CT Images.

ABSTRACT: Primary hepatic gastrointestinal stromal tumor is an extremely rare type of liver tumor with an unknown origin and poor prognosis and usually lacking specific symptoms. This makes it difficult to make an accurate diagnosis. We report the case of a 56-year-old man with primary hepatic gastrointestinal stromal tumor demonstrating multiple heterogeneous lesions with intense FDG uptake in the liver on PET/CT mimicking hepatocellular carcinoma or sarcoma. Primary hepatic gastrointestinal stromal tumor should be considered among the differential diagnoses when multiple FDG-avid primary liver neoplasms are found in patients with malignant characteristic on PET/CT imaging.

Giant Cell Tumor of Lumbar Vertebrae on MR and 18F- FDG PET/CT: A Case Report and Literature Review.

Teaching Point: Giant cell tumor of bone may show a moderate to high FDG uptake, and attention should be paid to differentiate from malignant tumors.

Hepatic epithelioid angiomyolipoma mimicking hepatocellular carcinoma on MR and 18F-FDG PET/CT imaging: A case report and literature review.

Hepatic epithelioid angiomyolipoma (HEAML) is a rare hepatic mesenchymal tumor with malignant potential. Unlike hepatic angiomyolipoma, HEAML is devoid of adipocytes. Thus, it is easy to be misdiagnosed as other tumors of liver, especially hepatocellular carcinoma (HCC) on preoperative imaging examinations. Herein, we present a case of HEAML mimicking HCC on magnetic resonance (MR) and fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in a 50-year-old female. After the primary diagnosis of HCC, the patient underwent a laparoscopic resection. The histopathology and immunohistochemical staining helped to reach the final diagnosis of HEAML. The important sign of central vessel can be seen on MRI in this case. The average apparent diffusion coefficient (ADC) value of the HEAML is 0.86±0.13x10-3mm2/s, which is lower than that of 0.97±0.02?10-3mm2/s of the normal liver. Previous literature on 18F-FDG PET/CT imaging of HEAML is limited to only 2 cases. The 18F-FDG PET/CT images of HEAML with high 18F-FDG accumulation with a maximum standardized uptake value (SUVmax) of 8.88 and extensive necrosis are presented, indicating its malignant potential. This case aims to improve the ability of differential diagnosis from HCC on multimodal imaging, and provides values for further 18F-FDG PET/CT related studies.

Construction of a lncRNA-associated competing endogenous RNA regulatory network after traumatic brain injury in mouse.

Traumatic brain injury (TBI) is a major public health problem worldwide which causes high mortality and disability. Functioning as microRNA (miRNA) sponges, long non-coding RNA (lncRNA) regulates the expression of protein-coding genes in a competing endogenous RNA (ceRNA) network. However, the lncRNA-associated ceRNA in TBI remains unclear. In this study, we processed the raw SRR files of mice cortex samples of sham injury (n = 3) and TBI groups (n = 3) to count files. Then, the expression profiles of lncRNAs and mRNAs were identified, and 86 differentially expressed (DE) lncRNAs and 1201 DEmRNAs between sham and TBI groups were identified. The DEmRNAs were used to perform enrichment analyses. Next, a lncRNA-miRNA-mRNA regulatory ceRNA network was constructed. The network consisted of 23 mRNAs, 5 miRNAs and 2 lncRNAs. The expression alternations of the 5 miRNAs were validated via qRT-PCR. The subnetwork of hub lncRNA Neat1 was extracted. We identified a potential inflammatory associated regulatory axis: Neat1/miR-31-5p/Myd88 axis. The PPI network based on DEmRNA involved in ceRNA network was constructed PPI networks to identify the hub genes. Finally, DElncRNAs and DEmRNAs were selected randomly and validated by qRT-PCR. In conclusion, with the lncRNA-miRNA-mRNA ceRNA network provided above, we can improve our understanding of the regulatory mechanisms and interaction among lncRNAs, miRNAs and mRNAs in TBI process.

A case of pancreatic carcinosarcoma detected on PET/CT.

Primary pancreatic carcinosarcoma is a rare and malignant neoplasm composed of a mixture of sarcomatous and carcinomatous elements. With fewer than forty cases ever reported, the recognition of this rare phenomenon can be difficult. In the present case, a 73-year-old woman with pancreatitis underwent computed tomography which revealed wall-off pancreatic necrosis. Following initial and delayed fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) revealed high uptake of tracer in pancreatic mass, endoscopic biopsy revealed carcinosarcoma. The patient underwent laparoscopic pancreato-caudal resection and was confirmed to have pancreatic carcinosarcoma on microscopic evaluation. The case shows the importance of PET/CT on the early diagnosis in pancreatic mass, and suggests pancreatic carcinosarcoma should be considered as a possible differential diagnosis, which can hasten treatment and improve patient outcomes.

Changes of [18F]FDG-PET/CT quantitative parameters in tumor lesions by the Bayesian penalized-likelihood PET reconstruction algorithm and its influencing factors.

BACKGROUND: To compare the changes in quantitative parameters and the size and degree of 18F-fluorodeoxyglucose ([18F]FDG) uptake of malignant tumor lesions between Bayesian penalized-likelihood (BPL) and non-BPL reconstruction algorithms. METHODS: Positron emission tomography/computed tomography images of 86 malignant tumor lesions were reconstructed using the algorithms of ordered subset expectation maximization (OSEM), OSEM + time of flight (TOF), OSEM + TOF + point spread function (PSF), and BPL. [18F]FDG parameters of maximum standardized uptake value (SUVmax), SUVmean, metabolic tumor volume (MTV), total lesion glycolysis (TLG), and signal-to-background ratio (SBR) of these lesions were measured. Quantitative parameters between the different reconstruction algorithms were compared, and correlations between parameter variation and lesion size or the degree of [18F]FDG uptake were analyzed. RESULTS: After BPL reconstruction, SUVmax, SUVmean, and SBR were significantly increased, MTV was significantly decreased. The difference values of %ΔSUVmax, %ΔSUVmean, %ΔSBR, and the absolute value of %ΔMTV between BPL and OSEM + TOF were 40.00%, 38.50%, 33.60%, and 33.20%, respectively, which were significantly higher than those between BPL and OSEM + TOF + PSF. Similar results were observed in the comparison of OSEM and OSEM + TOF + PSF with BPL. The %ΔSUVmax, %ΔSUVmean, and %ΔSBR were all significantly negatively correlated with the size and degree of [18F]FDG uptake in the lesions, whereas significant positive correlations were observed for %ΔMTV and %ΔTLG. CONCLUSION: The BPL reconstruction algorithm significantly increased SUVmax, SUVmean, and SBR and decreased MTV of tumor lesions, especially in small or relatively hypometabolic lesions.

Clinical significance of extra-thyroid 99mTc-pertechnetate uptake before initial radioiodine therapy for differentiated thyroid carcinoma.

OBJECTIVE: To analyse the clinical characteristics of extra-thyroid 99mTc-pertechnetate uptake in order to explore the effect of the phenomenon on radioactive iodine (RAI) therapy for differentiated thyroid carcinoma (DTC) and its clinical significance. METHODS: This study retrospectively selected patients with DTC and extra-thyroid 99mTc-pertechnetate uptake. The clinical features, location, location count and extra-thyroid 99mTc-pertechnetate uptake distribution were analysed, combined with the uptake rate, stimulated thyroglobulin (sTg) level, post-therapy whole-body scan and curative effect. RESULTS: A total of 38 patients were enrolled in the study and 65 extra-thyroid 99mTc-pertechnetate foci were detected. Thirty-four patients showed abnormal 99mTc-pertechnetate uptake in the lymph nodes (26 of 38; 68.4%), lungs (four of 38; 10.5%) and bones (four of 38; 10.5%). The corresponding uptake rates were 0.2%, 0.2% and 0.8%, respectively. The uptake rate and sTg were significantly positively correlated (r = 0.36). 131I uptake was found in 36 patients at the 99mTc-pertechnetate uptake site. The number of iodine uptake foci was significantly higher than that of 99mTc-pertechnetate uptake foci. The sTg value and pathological staging significantly differed between the excellent and nonexcellent response groups (Z = -2.947 and Z = -2.348, respectively). CONCLUSION: Extra-thyroid 99mTc-pertechnetate uptake mostly indicated metastases with specific clinical features, which may have prognostic value for the judgment of iodine uptake function and the RAI therapy plan.

Blood prognostic predictors of treatment response for patients with papillary thyroid cancer.

BACKGROUND: Papillary thyroid cancer (PTC) is a very common malignant disease with high morbidity. We needed some pretreatment indicators to help us predict prognosis and guide treatment. We conducted a study about some pretreatment prognostic indicators. METHODS: This clinical study recruited 705 postoperative PTC patients (211 males, 494 females). Clinical data before radioactive iodine (RAI) treatment were collected. Patients' response to therapy were classified into two categories: 'Good Prognosis Group' (GPG) and 'Poor Prognosis Group' (PPG), according to '2015 American Thyroid Association Guidelines'. Differences of indicators between different prognosis groups were compared. Odds ratios (ORs) were calculated by univariate/multiple binary logistic regression models. Difference of body mass index (BMI) changes before and after RAI treatment between different prognosis groups was also compared. RESULTS: A total of 546 (77.45%) belonged to GPG, and 159 (22.55%) belonged to PPG. Platelet (PLT), neutrophil (NEUT), PLT subgroups, and combination of red blood cell distribution width (RDW) and BMI (COR-BMI) were different between two prognosis groups. The significance of the difference between the two groups of BMI disappeared after the Bonferroni correction. PLT and PLT subgroups had detrimental effects on the risk of PPG; T stage had a positive effect on the risk of PPG. PLT subgroup showed a detrimental effect on the risk of PPG when we included additional covariates. CONCLUSIONS: We found that lower pretreatment PLT levels may indicate a poor prognosis for PTC. The relationship between platelet-derived growth factor (PDGF) and radiation sensitivity may be the key to this association.

Knockdown of LINC02471 Inhibits Papillary Thyroid Carcinoma Cell Invasion and Metastasis by Targeting miR-375.

BACKGROUND: LncRNAs play important roles in papillary thyroid carcinoma (PTC). LINC02471 has been reported to be related to PTC prognosis. The current study aimed to investigate the effects of LINC02471 on human PTC cells. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to examine LINC02471 expression in PTC tissues and cells and miR-375 expression in PTC cells. SiLINC02471, miR-375 mimic and miR-375 inhibitor were used for cell transfection. Cell proliferation, apoptosis, migration, and invasion were detected by performing Cell Counting Kit-8 (CCK-8), clone formation assay, flow cytometry, scratch assay, and transwell assay. Western blot was carried out to detect protein levels of E-cadherin, N-cadherin and Snail. The target gene for LINC02471 was verified by dual-luciferase reporter assay. RESULTS: LINC02471 was highly expressed in PTC tissues and cells. After silencing LINC02471, cell proliferation, migration and invasion were reduced, but cell apoptosis was increased. SiLINC02471 increased the expressions of E-cadherin and miR-375, and inhibited the expressions of N-Cadherin and Snail. LINC02471 directly targeted miR-375 in PTC cells. Overexpression of miR-375 inhibited the proliferation, migration, invasion of PTC cells and reduced the expressions of N-Cadherin and Snail but promoted the cell apoptosis and increased E-cadherin expression, while miR-375 inhibitor produced opposite effects to overexpressed miR-375. After inhibiting miR-375 expression, siLINC02471 reversed the effect of miR-375 inhibitor. CONCLUSION: LINC02471 could promote the development of PTC. Knocking down LINC02471 could inhibit invasion and metastasis and promote PTC cell apoptosis through directly targeting miR-375.

Diagnostic value of clinical parameters and parathyroid scintigraphy for asymptomatic primary hyperparathyroidism.

OBJECTIVE: The purpose of this study was to evaluate the diagnostic value of clinical parameters and parathyroid scintigraphy for asymptomatic primary hyperparathyroidism (aPHPT), including quantitative parameter of laboratory and semiquantitative parameters derived from technetium-99m- metoxyisobutylisonitrile (99mTc-MIBI) single photon emission computed tomography/computed tomography (SPECT/CT). SUBJECTS AND METHODS: Two hundred and fourteen patients who had been diagnosed as PHPT and underwent surgical treatment were enrolled in this study. All patients were divided into two groups: aPHPT and symptomatic PHPT (sPHPT). Dual tracer 99mTc pertechnetate/99mTc-MIBI, dual time point and tomography scintigraphy with 99mTc-MIBI SPECT/CT were performed. Clinical parameters included basic information, serum calcium (Ca), phosphorus (P), parathyroid hormone (PTH) and alkaline phosphatase (ALP) levels. Semiquantitative parameters of parathyroid scintigraphy included the average counts of early parathyroid (PT1), late parathyroid (PT2), early thyroid (T1) and late thyroid (T2), the ratio of PT1/ T1 (R1), the ratio of PT2/ T2 (R2), parathyroid washout (PTW=(PT1-PT2)/PT1) and retention index (RI=(R2-R1)/R1). P<0.05 was considered as statistically significant. RESULTS: A total of 167 aPHPT patients (46 males, 121 females) were studied. One hundred and seventy four One hundred and seventy four174 parathyroid glands were removed after operation: 146 (87.4%) lesions were adenoma, 12 (7.2%) lesions were hyperplasia and 1 (0.6%) lesion was adenocarcinoma. There were significant differences in previous history (P=0.000), echo of parathyroid (P=0.004), thyroid function (P=0.029), clinical course (Z=-3.422, P=0.001), 99mTc-pertechnetat thyroid uptake (TcTU) (Z=-2.126, P=0.033), serum Ca level (t=-2.926, P=0.004) and serum PTH level (Z=-3.028, P=0.002) between aPHPT and sPHPT. For patients with aPHPT, there were significant differences for serum Ca level (t=2.832, P=0.005), R2 (Z=-2.597, P= 0.009) and RI (Z=-2.100, P=0.036) between adenoma and hyperplasia, and serum Ca level in aPHPT patients with adenoma was significantly higher compared with patients with hyperplasia. The areas under the curve (AUC) of clinical course, TcTU, serum Ca and PTH levels were 0.662, 0.399, 0.642 and 0.645 respectively for differential diagnosis of aPHPT and sPHPT. The AUC of R2 and RI were 0.737 and 0.692 respectively for differential diagnosis of adenoma and hyperplasia in patients with aPHPT. The sensitivity, negative predictive value (NPV) and accuracy for diagnosing aPHPT combined 99mTc-MIBI SPECT/CT with ultrasound (US) were significantly higher than dual tracer, dual time point, 99mTc-MIBI SPECT/CT and US, which were 97.5%, 95.2% and 55.6% respectively. CONCLUSION: Laboratory inspection and semi-quantitative parameters of parathyroid scintigraphy had higher value for differential diagnoses of aPHPT and sPHPT, the same for adenoma and hyperplasia in patients with aPHPT. When combined 99mTc-MIBI SPECT/CT with US, the diagnostic efficiency would be significantly improved.

Focally Increased Iodine Activity in a Small Thymic Cyst.

A 40-year-old man with biopsy-proven papillary thyroid cancer received I radiotherapy. Posttherapy scan showed not only multiple foci of intense activity in the neck but also a small focal activity in the region of right upper mediastinum, confirmed by SPECT/CT images. This activity was suspected as mediastinal lymph node metastasis. However, pathology examination after the resection showed thymic cyst.

99mTcO4-/99mTc-MIBI dual-tracer scintigraphy for preoperative localization of parathyroid adenomas.

OBJECTIVE: To investigate the accuracy of dual-tracer scintigraphy for locating parathyroid adenomas in patients with primary hyperparathyroidism (PHPT). METHODS: We reviewed 268 patients with PHPT. All patients underwent technetium-99m pertechnetate (99mTcO4-) scintigraphy and technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) dual-tracer scintigraphy of the thyroid and parathyroid glands, respectively. 99mTcO4- planar scintigraphy was carried out initially followed by dual-phase 99mTc-MIBI single-photon emission computed tomography (SPECT)/CT the next day. The findings were combined and interpreted. Individual 99mTc-MIBI and dual-tracer scintigraphy were both analyzed. The sensitivity, specificity, and accuracy were determined in relation to surgical findings. The average interval between scan and surgery was 13 days. RESULTS: The positive and negative predictive values of 99mTc-MIBI SPECT/CT were 92.0% and 71.3%, respectively, and the sensitivity, specificity, and accuracy were 88.3%, 79.2%, and 85.8%, respectively. The positive and negative predictive values of dual-tracer scintigraphy were 96.3% and 82.3%, respectively, and the sensitivity, specificity, and accuracy were 92.9%, 90.3%, and 92.2%, respectively. Youden's index for dual-tracer scintigraphy and 99mTc-MIBI SPECT/CT were 0.83 and 0.63, respectively. CONCLUSIONS: These finding suggest that 99mTcO4- and 99mTc-MIBI dual-tracer scintigraphy is more accurate than other scintigraphy methods for detecting parathyroid adenoma, and may thus be the most suitable imaging technique in patients with PHPT.

Application of the alteration uptake ratio of 99mTc-MIBI scintigraphy for evaluating the efficacy of neoadjuvant chemotherapy in osteosarcoma patients.

BACKGROUND: We aimed to semi-quantitatively evaluate using technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) scintigraphy the efficacy of neoadjuvant chemotherapy in osteosarcoma (OS) patients. SUBJECTS AND METHODS: A hundred and two patients with OS were retrospectively included in this study. All of them underwent 99mTc-MIBI scintigraphy before and after neoadjuvant chemotherapy. Semi-quantitative parameters including the uptake ratio (UR) and alteration of uptake ratio (AUR) were calculated for each patient. According to tumor necrosis rate (TNR), patients were classified into three group: a) Poor response group (grade I, TNR: less than 50%), b) Partial response group (grade II, TNR: 50%-89%) and c) Good response group (grade III, TNR: greater than 90%). The linear regression analysis of the AUR versus TNR was carried out. RESULTS: Poor response, partial response and good response were found in 30, 52 and 20 patients, respectively. In the poor-response group the URpre and URpost were 1.68±0.44 and 1.83±0.71, respectively and the AUR was -0.02±0.33. In the partial-response group the URpre and URpost were 2.42±1.42 and 1.59±0.71, respectively and the AUR was 0.28±0.18. In the good-response group the URpre and URpost were 2.58±0.61 and 1.21±0.16, respectively and the AUR was 0.46±0.10. There was a statistically significant difference of the AUR between poor-response and partial-response groups (P<0.01) and also between the poor-response and good-response groups (P<0.01). The linear regression analysis of the AUR versus TNR which showed a significantly positive correlation (r=0.76). CONCLUSION: The AUR was significant after neoadjuvant chemotherapy in the partial-response group and in the good-response group. Furthermore, it exhibited a positive correlation with TNR. All results indicated that 99mTc-MIBI scintigraphy can be used to evaluate neoadjuvant chemotherapy for OS patients.

Comparison of the efficacy of strontium-89 chloride in treating bone metastasis of lung, breast, and prostate cancers.

OBJECTIVE: The aim of this study was to comparatively evaluate the efficacy of strontium-89 chloride (89 SrCl2) in treating bone metastasis-associated pain in patients with lung, breast, or prostate cancer. MATERIALS AND METHODS: The 126 patients with lung cancer included 88, 16, 15, 4, and 3 patients with adenocarcinoma, squamous cell carcinoma, nonsmall cell carcinoma, mixed carcinoma, and small cell carcinoma, respectively, and the control group consisted of patients with breast (71 patients) or prostate cancer (49 patients) who underwent 89 SrCl2 treatment during the same period. The treatment dose of 89 SrCl2 was 2.22 MBq/kg. RESULTS: The efficacy rate of treatment in the lung cancer group was 75.4%, compared to 95.0% in the control group. Approximately 67% of patients with lung cancer and bone metastases and 47% of control patients exhibited mild-to-moderate reductions of leukocyte and platelet counts 4 weeks after 89 SrCl2 treatment. CONCLUSIONS: 89 SrCl2 can safely and effectively relieve bone pain caused by bone metastasis from lung cancer. However, its efficacy was lower in patients with lung cancer with bone metastasis than in those with breast or prostate cancer with bone metastasis, and its effects on the peripheral hemogram were also significantly stronger in the lung cancer group.

Comprehensive characterization of differentially expressed genes in thyroid cancer.

AIM: To explore the patterns of gene expression and functionally characterize the differentially expressed genes (DEGs) in thyroid cancer. METHODS: DEGs were determined between 57 paired thyroid cancer and noncancerous tissues using DESeq2. Subsequently, the main functions of the DEGs were studied by a variety of analyses. RESULTS: We identified a cohort of 752 upregulated and 309 downregulated DEGs in thyroid cancer. Several hub DEGs were found in the protein-protein interaction networks. We also revealed a set of DEGs that were dysmethylated, involved in copy number variations and associated with clinical features in thyroid cancer. CONCLUSION: These results provide some novel findings on DEGs in thyroid cancer, which will be useful to guide further investigation and target therapy for this disease. [Formula: see text].

Clinical value of radionuclide small intestine transit time measurement combined with lactulose hydrogen breath test for the diagnosis of bacterial overgrowth in irritable bowel syndrome.

OBJECTIVE: Small intestine bacterial overgrowth (SIBO) may be a pathogenetic factor for irritable bowel syndrome (IBS). This syndrome cannot be explained by structural abnormalities and has no specific diagnostic laboratory tests or biomarkers. We studied quantitatively and semi-quantitatively, using lactulose hydrogen breath test (LHBT), small intestinal transit time (SITT) (99m)technetium-diethylene triamine pentaacetic acid ((99m)Tc-DTPA) in order to examine the mobility of small intestine as an indication of bacterial overgrowth in patients. METHODS: Eighty nine consecutive patients who met Rome criteria for IBS were retrospectively studied. According to the diagnostic criteria, all patients were divided into two groups: the SIBO group and the non-SIBO group. The tracer was a mixture of 10g lactulose, 37MBq (99m)Tc-DTPA and 100mL water. The patient drank the whole mixture during 1min and the SITT study started immediately. The SITT and the LHBT followed every 15min for up to 3h after emptying the urine bladder. Spearman's rank correlation was applied to assess the correlation of oro-cecum transit time (OCTT) between imaging and LHBT. The semi-quantitative index between the SIBO group and the non-SIBO group was analyzed with Wilcoxon's rank sum test. If there was significant group difference, the receiver operating characteristic (ROC) curve was used. P<0.05 was considered significant. RESULTS: The median and inter-quartile range for OCTT for the LHBT (OCTT-L) for all patients was 90min and 60min, respectively, and 75min and 45min for OCTT for the SITT study (OCTT-i). There was positive correlation between OCTT-L and OCTT-i at the 0.05 level (R=0.290, P=0.000). There were no differences in OCTT-i and in the rate of radioactivity (counts of regions of interest ROI) over the abdomen between the SIBO group and the non-SIBO group (P=0.116 and 0.290). There were significant differences in the temporal association of the hydrogen (H2) value with OCTT-i (H2-i) and OCTT-L between the two groups (P=0.000 and 0.000). The areas under the curve (AUC) of H2-i and OCTT-L were 0.749 and 0.138 respectively. CONCLUSION: Small intestinal transit time study using a lactose hydrogen breath test and (99m)Tc-DTPA is a real-time test for small intestine bacteria overgrowth in IBS patients and can be used as an indicator of the disease.

A combined simple bubbling method with high performance liquid chromatography purification strategy, higher radiochemical yield and purity and faster preparation of carbon-11-raclopride.

OBJECTIVE: Carbon-11-raclopride (¹¹C-R) is a positron-emitting radiotracer successfully used for the study of cognitive control and widely applied in PET imaging. A simple automated preparation of ¹¹C-R by using the reaction of carbon-(11)-methyl triflate (¹¹C-MeOTF) or ¹¹C-methyl iodide (¹¹C-MeI) with demethylraclopride is described. METHODS: Specifically we used a simple setup applied an additional "U" reaction vessel for ¹¹C-MeOTf compared with ¹¹C-MeI and assessed the influence of several solvents and of the amount of the percussor for ¹¹C-methylation of demethylraclopride by the bubbling method. The reversal of retention order between product and its precursor has been achieved for ¹¹C-R, enabling collection of the purified ¹¹C-R by using the HPLC column after shorter retention time. RESULTS: By the improved radiosynthesis and purification strategy, ¹¹C-R could be prepared with higher radiochemical yield than that of the previous studies. The yield for ¹¹C-MeOTf was 76% and for ¹¹C-CH3I >26% and with better radiochemical purity (>99% based on both ¹¹C-MeOTf and ¹¹C-MeI) as compared to the previously obtained purity of ¹¹C-R using HPLC method with acetonitrile as a part of mobile phase. Furthermore, by using ethanol as the organic modifier, residual solvent analysis prior to human injection could be avoided and ¹¹C-R could be injected directly following simple dilution and sterile filtration. CONCLUSION: Improved radiosynthesis and HPLC purification in combination with ethanol containing eluent, extremely shortened the time for preparation of ¹¹C-R, gave a higher radiochemical yield and purity for ¹¹C-R and can be used for multiple and faster synthesis of ¹¹C-R and probably for other ¹¹C-labeled radiopharmaceuticals.

Study on the executive function of attention in depression patients based on SPECT technology.

OBJECTIVE: To investigate event-related potential in executive function of attention and characteristics of cerebral perfusion by 99mTc-ECD single-photon emission computed tomography (SPECT) in depression patients receiving the Oddball task. METHODS: A total of 30 depression patients and 30 normal control subjects were selected to carry out the Oddball task. Event-related potential (ERP) technology combined with SPECT imaging technology was used to compare the reaction time, ERP-P300 latency and amplitude, and cerebral perfusion characteristics on sites of brain. RESULTS: Compared with normal control group, when the Oddball task was performed, the reaction time or ERP-P300 latency was not significantly different in depression patients (P > 0.05), but P300 amplitude on F3 and F7 sites increased significantly (t = 2.241, 2.245, respectively; each P < 0.05). SPECT showed cerebral hypoperfusion in the right basal ganglia, left frontal lobe and temporal lobe of depression patients. CONCLUSION: During the Oddball task, the P300 amplitude on F3 and F7 sites increased significantly in depression patients, who also showed cerebral hypoperfusion in the right basal ganglia, left frontal lobe and temporal lobe. The result suggests that depression patients have brain region functional abnormalities involving attention execution and implicit memory processing during auditory channel information processing.