Gliomas are the most common primary intracranial tumors in adults, among which high-grade glioma patients are characterized by short survival and poor prognosis. The diagnosis, treatment, evaluation of effective treatments, and prognosis prediction of high-grade gliomas are of great significance for improving patient survival. Conventional enhanced magnetic resonance imaging has deficiencies in delineating tumor extent, identifying tumor progression and treatment-related changes. Therefore, there is a broad consensus to incorporate amino acid PET, and ¹⁸F-FET PET inparticular, into the diagnostic and therapeutic process of high-grade gliomas. In this article, we review the new research progress of ¹⁸F-FET PET in the diagnosis and treatment of adult high-grade glioma in recent years.

ObjectiveTo investigate a suspected outbreak of carbapenem-resistant Acinetobacter baumannii （CRAB） nosocomial infection in an intensive care unit （ICU） and provide scientific evidence for prevention and control of multi-drug resistant nosocomial infection. MethodsClinical and epidemiological data of 4 patients with CRAB infection were retrospectively investigated in the ICU of Renji Hospital in November 2021. Environmental hygiene monitoring and multilocus sequence typing （MLST） were conducted and intervention measures were taken. ResultsA total of 4 cases with CRAB infection were identified， among which 1 case was determined to be community-acquired and3 cases were hospital-acquired. The isolated strains shared the same drug resistance， and were all classified into ST368 type. In the surface and hand samples （n=40）， 2 CRAB strains were detected in the air filter beside the bed of the first case， with a detection rate of 5%. After adopting comprehensive prevention and control strategies， including environmental cleaning and disinfection， hand hygiene， staff management and training， and supervision， no similar case with CRAB infection was found. ConclusionThis suspected outbreak of CRAB nosocomial infection may be induced by inadequate environmental cleaning and disinfection， and inadequate implementation of hand hygiene. Timely identification， investigation， and targeted measures remain crucial to effective control of possible nosocomial infection.

Objective:To explore the diagnosis and clinical characteristics of multi-slice spiral computed tomography angiography(MSCTA)on acute aortic syndrome(AAS).Methods:A total of 185 patients with suspected AAS who were treated in Fuyang People's Hospital from June 2020 to July 2022 were selected,and the diagnostic results of digital vascular subtraction(DSA)were taken as the"gold standard".Before confirmation,MSCT plain scan and MSCTA examination were conducted,and the positively and negatively predictive values of MSCT plain scan and MSCTA were calculated by using four-cell table method.The area under curve(AUC)values,sensitivities and specificities of MSCT plain scan and MSCTA in diagnosing AAS were analyzed by using receiver operating characteristic(ROC)curve model.Results:As the gold standard of DSA diagnostic results,82 cases of 185 patients with suspected AAS were confirmed as AAS.The positively and negatively predictive values of MSCT plain scan were 68.35%and 73.58%,respectively.The positively and negatively predictive value of MSCTA examination were 96.30%and 96.15%,respectively.The diagnostic accuracy of MSCTA was significantly higher than that of MSCT plain scan(x2=42.092,P<0.05).The detection rates of laceration locations(ascending aorta,aortic arch and descending aorta)in MSCTA were significantly higher than that in MSCT plain scan(x2=6.788,4.000,12.974,P<0.05),respectively.ROC curve analysis showed that the AUC values of MSCT plain scan and MSCTA were respectively 0.698 and 0.946 in diagnosing AAS.Conclusion:MSCTA has a higher efficiency in diagnosing AAS,and AAS mostly includes the aortic dissection separation and aortic intramural hematoma.

Objective:To investigate the radiation dosimetry and biodistribution of 68Ga-FAPI-04 PET/CT in patients with hepatobiliary tumor. Methods:A total of six patients with hepatic lesions who underwent PET/CT examination in Peking Union Medical College Hospital were enrolled. After intravenous injection of radiotracer 68Ga-FAPI-04 at (170.57 ± 14.43) MBq, whole-body imaging were performed at the time points of 3, 10, 15, 20, 30 and 60 min, respectively. Biodistribution pattern was observed. Regions of interest were manually delineated. Radiation dosimetry of all target organs were calculated by Olinda/EXM software. Results:The radioactive uptake dissipated gradually in liver whereas it was relatively stable in tumor lesions. The average SUV max of tumor lesions reached the maximum value (13.87± 2.55) at 20 min after injection. The target-to-background ratio increased with time, reaching the maximum value (10.09 ± 8.17) at 30 min after injection. The average effective dose in total body was (0.020 ± 0.002) mSv/MBq and organ with the highest effective dose was bladder wall at (0.146 ± 0.035) mSv/MBq. Conclusions:The effective dose in total body of 68Ga-FAPI-04 was similar to that of 18F-FDG. 68Ga-FAPI-04 is expected to be a PET/CT radiotracer for hepatobiliary tumors in consideration of rapid tumor uptake, low accumulation of liver background, and no influence of blood sugar levels.

Objective:To investigate the segmentation methods of pancreatic ductal adenocarcinoma (PDAC) tumor regions in 18F-fluorodeoxyglucose (FDG) PET/CT images, as well as their impact on radiomic features-based pathological grade prediction. Methods:A total of 72 patients (46 males, 26 females, age range: 25-87 years) with pathologically confirmed PDAC and a preoperative 18F-FDG PET/CT scan in Peking Union Medical College Hospital between September 2010 and January 2016 were enrolled retrospectively. The cohort of patients was classified as well differentiated group and non-well differentiated group based on the pathological grade of PDAC, and patients were divided into training set and validation set in the ratio of 3∶1 randomly. Two physicians performed manual contours in the tumor region (referred as region of interest (ROI)_M1 and ROI_M2) and semi-automatic ROIs based on standardized uptake value (SUV) gradient edge search (referred as ROI_G) and 40% threshold applied to the maximum SUV (SUV max; referred as ROI_S) were drawn. The four types of segmentation results were compared in terms of volume and Dice similarity coefficient (DSC). Shape, first-order, and texture features were extracted from PET/CT original and preprocessed images, and the interclass correlation coefficient (ICC) was used to assess each feature′s consistency across all segmentations. Kruskal-Wallis rank sum test, independent-sample t test or z test were used to analyze the data. The area under the receiver operating characteristic curve was used to assess model accuracy, and cross validation was used to assess generalization ability. Results:There were 55 patients in the training set (14 well differentiated cases and 41 non-well differentiated cases) and 17 patients in the validation set (4 well differentiated cases and 13 non-well differentiated cases). A total of 44 selected features were predictive of the pathological grade of PDAC among 20 feature groups. There was significant difference among the volumes of ROI_M1, ROI_M2, ROI_G and ROI_S (10.29(4.01, 19.43), 9.34(4.26, 17.27), 11.86(5.52, 19.74) and 15.08(9.62, 27.44) cm 3; H=18.641, P<0.05). The degree of contour coincidence and feature consistency between ROI_M1 and ROI_M2 were both higher (DSC=0.86 (0.76, 0.90), ICC=0.86 (0.74, 0.94)). Compared to manual contours, the degree of contour coincidence and feature consistency of ROI_G (DSC: 0.86(0.75, 0.91), 0.91(0.85, 0.96); ICC: 0.87(0.72, 0.94), 0.94(0.88, 0.98)) were better. There was no statistically significant difference in model accuracy or generalization ability between ROI_M1 and ROI_G ( z=1.052, t=0.712, both P>0.05). The accuracy of ROI_M2 was better than ROI_G ( z=3.031, P=0.002), but the generalization ability of ROI_M2 was insufficient ( t=3.086, P=0.012). Conclusions:Although the manual contour prediction models are highly accurate, their performance are unstable. Semi-automatic contouring based on gradient can achieve comparable accuracy to manual contouring, and the model′s generalization ability is stronger.

Objective:To prepare 68Ga-fibroblast activation protein inhibitor (FAPI)-04, and evaluate its biodistribution and imaging characteristics in animals and healthy volunteers, in order to investigate the clinical translation potential. Methods:68Ga-FAPI-04 was synthesized by a manual method and its radiolabeling yield, radiochemical purity, and stability ( in vivo and in vitro) were analyzed. ICR mice ( n=16) were scarified at 5, 30, 60 and 120 min postinjection of 68Ga-FAPI-04 (1.11 MBq) to measure radioactive counts in main organs. The dynamic mircoPET imaging was acquired for 60 min on 3 ICR mice, and tumor imaging capabilities were examined with nude mice bearing HepG2 tumors. Furthermore, 2 healthy volunteers (1 male with age of 64 years, 1 female with age of 56 years) were recruited for the investigation of probe biodistribution in humans. A serial whole-body dynamic PET/CT scan was performed immediately following injection. Results:68Ga-FAPI-04 was synthesized within 20 min with the radiochemical yield of (68.7±4.0)% (decay corrected). The radiochemical purities of 68Ga-FAPI-04 were over 99% and the products were stable for 180 min in vitro and for 90 min in blood. 68Ga-FAPI-04 was mainly cleared through urinary tracts, while other organs only showed mild tracer accumulation. MicroPET imaging showed high uptake of 68Ga-FAPI-04 in the tumor tissue of mice, and the ratio of tumor/liver was 2.14±0.01 (35 min). The PET/CT imaging results of healthy volunteers revealed 68Ga-FAPI-04 could be quickly cleared. Conclusion:68Ga-FAPI-04 has many advantages for PET imaging, such as easy labeling, good stability, quick clearance and low background signals in the liver, which can be used as an attractive PET tracer for detection hepatocellular carcinoma.

Objective: To assess the interobserver variations in delineating the planning target volume (PTV) and organs at risk (OAR) using different contouring methods during intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC), aiming to provide references for the quality control of multi-center clinical trials. Methods: The PTV and OAR of CT image of 1 NPC patient manually delineated by 10 physicians from 8 different radiation centers were defined as the " manual contour group" , and the OAR auto-contoured using the ABAS software and modified by the physicians were defined as the " auto+ manual contour group" . The maximum/minimum ratio (MMR) of the PTV and OAR volumes, and the coefficient of variation (CV) for different delineated contours were comparatively evaluated. Results: Large variation was observed in the PTV and OAR volumes in the manual contour group. The MMR and CV of the PTV were 1.72-3.41 and 0.16-0.39, with the most significant variation in the PTV_nd (MMR=3.41 and CV=0.39 for the PTV_nd-L). The MMR and CV of the manually contoured OAR were 1.30-7.89 and 0.07-0.67. The MMR of the temporal lobe, spinal cord, temporomandibular joint, optic nerve and pituitary gland exceeded 2.0. Compared with the manual contour group, the average contouring time in the auto+ manual group was shortened by 68% and the interobserver variation of the OAR volume was reduced with an MMR of 1.04-2.44 and CV of 0.01-0.37. Conclusions Large variation may occur in the PTV and OAR contours during IMRT plans for NPC delineated by different clinicians from multiple medical centers. Auto-contouring+ manually modification can reduce the interobserver variation of OAR delineation, whereas the variation in the delineation of small organs remains above 1.5 times. The consistency of the PTV and OAR delineation and the possible impact upon clinical outcomes should be reviewed and evaluated in multi-center clinical trials.

Objective To study the effect of age-related white matter changes (ARWMC) on first symptomatic ischemic stroke events in the oldsters. Methods For the prospective study, a total of 368 eligible oldsters were enrolled in the study from January 2010 to August 2012. The degrees of ARWMC were assessed by ARWMC scale;according to the scores, they were divided into non ARWMC group, mild-moderate ARWMC group and severe ARWMC group. The patients were followed up once every 3 months. The clinical endpoint events and time (first symptomatic ischemic stroke, myocardial infarction and all-cause death) were recorded. Analyses of variance and Chi-square test were used to compare the differences of clinical data among the 3 groups. COX regression was used to assess the risk differences of first symptomatic ischemic stroke in the oldsters of three groups. Results After an average of follow-up for 48.7 months, 50 participants (13.6％) had first symptomatic ischemic stroke;25 (25.8％) were categorized as the severe ARWMC group, 22 (10.9％) were as the mild-medium group, and 3 (4.4％) were as the non ARWMC group. Among the three groups, the differences in age, history of hypertension, systolic blood pressure, incidence of clinical endpoint events and first symptomatic ischemic stroke, and follow-up time of endpoint events were statistically significant (P<0.05); patients from the severe ARWMC group were the oldest, and had the longest history of hypertension, the highest systolic blood pressure, the highest incidence of clinical end events and first symptomatic ischemic stroke, and the shortest follow-up period for clinical end events. COX regression analysis showed that the risk of first symptomatic ischemic stroke in the severe ARWMC group was about 8 times higher than that in the non ARWMC group (hazard ratio=9.012, 95％CI: 2.310-35.154, P=0.002). Conclusion In oldsters, severe ARWMC often accompany hypertension history and poor blood pressure controll, and it is an independent and serious risk factor for long-term first symptomatic ischemic stroke.

Objective To investigate the characteristics of NEN metastasis with SSTR PET/CT and to correlate the results with FDG-PET and pathology.Methods From November 2011 to August 2016,a total of 43 patients with NEN (18 males,25 females;age range:26-74 years) were recruited into this retrospective study;they underwent 68Ga-DOTA-TATE PET/CT (TATE-PET) imaging 40-60 min after 44.4-229.4 MBq 68Ga-DOTA-TATE administration.Metastases in 31 patients were confirmed by histopathology and in 12 patients by follow-up and other imaging modalities.Twenty-eight of 43 patients finished routine FDG-PET in a week after TATE-PET.PET/CT results were considered positive when the metastatic lesions were tracer-avid.ROI was drawn over each lesion for size and SUV measurement.x2 test and Pearson correlation analysis were used for statistical analysis.Results (1) Of 43 patients,TATE-PET detection rates of metastasis in the liver,lymph nodes,bones.and lungs were 85.7％(30/35),12/13,7/7,2/3,respectively,with their corresponding SUVmax of 18.1(11.3-23.3),10.8(5.4-15.6),7.7(4.2-9.9) and 1.8(1.3-2.3),respectively.Statistical correlation between size and SUVmax was found in metastatic bone lesions(r=0.233,P＜0.05).(2) In 31 patients with histopathologically proven metastasis,TATE-PET detected 23/24 (95.8％) G2,1/2 G1 and 5/5 G3 metastases.G1 metastases were only found in the liver.(3)Among 28 patients underwent both TATE-PET and FDG-PET,there was no significant difference between the detecting rate of metastasis:89.2％ (25/28) vs 71.4％ (20/28);x2 =2.389,P＞0.05.Compared with FDG-PET,TATE-PET was superior in demonstrating metastasis in the liver and bones (70.0％ (14/20) vs 65.0％ (13/20),3/3 vs 2/3),equal in detecting lung metastasis (both 2/3) but inferior in demonstrating metastasis in lymph nodes (9/10vs 10/10).Conclusions The capability of TATE-PET in revealing NEN metastasis varies depending on lesion localization and histologic grade.TATE-PET and FDG-PET are complementary to each other in detection of NEN metastasis,but without obvious relationship to histologic grade.

Objective To evaluate the application of imaging analysis system based on three-dimension computed tomography (3D-CT)for the diagnosis of femoral trochlear dysplasia.Methods Between May 2013 and January 2014,30 patients were diagnosed as recurrent patella dislocation and received surgical treatment.All the patients received 3D-CT diagnosis of the knee joints preoperatively,and the data of 3D-CT were transferred to imaging analysis system with MIMICS software that would be used to get the trochlear dysplasia index.The patients were also received knee fluoroscopic detection.A true lateral view was also used for evaluation of the trochlear dysplasia as the classic method.The difference between the two methods was compared.And the sensitivity,specificity,positive and negative predictive value of the imaging analysis system were analyzed.Results The mean trochlear dysplasia index was 5.3 ± 1.8 mm (3.2 to 8.4 mm)using the classic fluoroscopic method,showing no significant difference from the result according to the imaging analysis system,5.2 ± 1.5 mm (3.5 to 8.1 mm).When the fluoroscopic method was set as the golden standard,the sensitivity,specificity,positive and negative predictive value of the imaging analysis system were 89.5％,81.8％,89.4％ and 82.0％ respectively.Conclusion The imaging analysis system based on 3D-CT of knee joints could provide acceptable results without good sensitivity and specificity,without significant differences from the classic fluoroscopic method.So it is a more safer and easier approach worthy of clinical implication.