To evaluate the features of mediastinal tuberculous lymphadenopathy in adults on CT, especially on enhanced CT scan. Methods Seventeen patients with adult mediastinal tuberculous lymphadenopathy proved by operation, biopsy, and (or) anti tuberculous therapy were evaluated on chest film and CT scan, and 6 patients were performed with enhanced CT scan. Results The chest film finding was intrathoracic mass and (or) hilar mass only in 6 patients, but CT detected 37 enlarged nodes in all patients. Most of the enlarged nodes were located in 2R and (or) 4R (59.4%). 30 nodes (81 1%) presented as low density in the center of nodes, and there were marked enhancement at the periphery areas of the nodes after enhancement in all 6 patients (100 0%). Conclusion CT scan, especially the enhanced CT scan, is the first method of choice to diagnose the mediastinal tuberculous lymphadenopathy in adults.

Objective To investigate the image characteristics and clinical application of 18F-FDG PET/CT in autoimmune pancreatitis (ALP).Methods The PET/CT images from six male patients (age ranging from 51 to 78(average 69) years) with AIP from 2005 to 2012 were studied retrospectively.Of the six patients,two had follow-up PET/CT images after steroid therapy.The morphologic abnormality was visually analyzed and SUV was calculated.Scores were obtained according to the SUV of pancreas compared with that of the liver (3 =SUV higher than liver,2=SUV similar to liver,1 =SUV lower than liver).The difference between the regular and delayed SUV was compared by paired t test using SPSS 17.0.Results All of the 6 patients showed diffuse FDG uptake in the entire pancreas with SUVmax of 3.2-6.0(5.2± 1.1).Five patients had score 3 and one had score 2.Five patients had delayed scan,of which 4 had increased uptake (SUVmax5.3-7.2),but the SUVmax was not significantly different compared to that before delay scan (4.8-6.0,t =-2.424,P＞0.05).Five patients showed extrapancreatic uptake,especially in the salivary glands.After the steroid therapy,the enlarged pancreas reduced and the intense uptake of the pancreas disappeared.The extrapancreatic uptake showed coinstantaneous remission.Conclusions Increasing FDG uptake at entire pancreas was observed in patients with AIP.18F-FDG PET/CT may be useful for detecting AIP and the associated extrapancreatic uptake,and monitoring the change after therapy,yet it needs further evaluation.

Objective To assess the val ue of 18-fluorodeoxy glucose (~18F-FDG) positron emission tomography( PE T)-CT in the detection of malignant bone metastases. Methods Thirty-five out of 332 patients, 89 lesions were detected on ~18 F-FDG PET-CT and were interpreted separately on PET, combined CT, and fused PE T-CT images. Results Of the 89 lesions detected on PET- CT images, 68 were malignant and 21 were benign lesions. PET alone identified 62 malignant lesions and 17 benign lesions. The diagnostic sensitivity, specificit y, and accuracy of PET alone for diagnosis of bone metastases were 91.2% (62/68) , 81.0% (17/21), and 88.8% (79/89), respectively. The combined CT alone identifi ed 55 malignant lesions and 16 benign lesions. The diagnostic sensitivity, s pecificity, and accuracy of combined CT alone were 80.9% (55/68), 76.2% (16/21), and 79.8% (71/89), respectively. The fused PET-CT images identified 64 maligna nt and 19 benign lesions. The diagnostic sensitivity, specificity, and accuracy of the fused PET-CT were 94.1% (64/68), 90.5% (19/21), and 93.2% (83/89), respe ctively. Conclusion In the diagnosis of bone metastases, ~18F-FDG PET-CT imaging reduces the false positive rate and increases the specificity. ~18F-FDG PET-CT imaging is helpful in the differentiation o f bone metastases from benign lesions.

Objective To evaluate the role of CT or Chest radiograph in diagnosis of chest wall tuberculosis.Methods The study population included 21 patients with chest wall tuberculosis confirmed by operation or biopsy. Chest radiograph and plain CT were performed in all cases, while enhanced CT in 9 cases , and all images were reviewed by 2 radiologists.Results Single soft tissue mass of the chest wall was detected in all cases on CT, but not on chest radiograph(?2=42.000,P

Objective To determine the value of 18F-FDG PET/CT in the detection of subsolid pulmonary nodules.Methods The 18F-FDG PET/CT imaging data of 44 patients (35 males,9 females,mean age (68.05±9.89) years) with 49 subsolid pulmonary nodules were retrospectively analyzed.There were 28 pure ground-glass nodules (pGGN) and 21 part-solid nodules (PSN),which were all confirmed by postsurgical pathology or imaging results during follow-up.The lesion size (dmax),ground-glass opacity (GGO) percentage,SUV retention index (RI),and the positive rates on PET images were accessed.The correlation between SUVmax and lesion size and GGO percentage was analyzed by Pearson correlation analysis.The SUVmax between benign and malignant pGGN,and that between malignant pGGN and PSN,were compared using two-sample t test.The diagnostic accuracy was compared using x2 test.Results (1) Six pGGN were benign while 43 nodules (including 22 pGGN and 21 PSN) were malignant among the 49 nodules.(2) SUVmax was positively correlated with lesion size (r=0.500,P＜0.05) and was negatively correlated with GGO percentage (r=-0.605,P＜0.05) for PSN,while SUVmax was positively correlated with lesion size (r=0.375,P＜0.05) for pGGN.(3) SUVmax was not significantly different (t =-0.813,P＞0.05) between 6 benign pGGN (0.78±0.25,range:0.50-1.20) and 22 malignant pGGN (0.91±0.34,range:0.40-1.70);SUVmax of 21 malignant PSN (2.10±1.16,range:0.60-5.60) was higher than that of 22 malignant pGGN (t=-4.645,P＜0.05).(4) When a nodule's activity being equal to or greater than that of mediastinal blood-pool was defined as malignancy,the accuracy rate of PSN (66.7％,14/21) was significantly higher than that of pGGN (9.1％,2/22; x2 =15.244,P ＜0.05).Based on the criteria for malignancy of RI＞10％,the accuracy rates for PSN and pGGN were 65.0％ (13/20) and 45.8％ (11/24),respectively (x2 =1.616,P＞0.05).Conclusion 18F-FDG PET/CT shows no clear advantage for diagnosis of pGGN,but is helpful for PSN.

Objective To analyze the characteristics of breast cancer blood supply before and after chemotherapy with low-dose CT perfnsion. Methods Fifteen patients with breast cancer underwent CT breast perfusion examination, which was performed before and after chemotherapy within 1 week on Siemens Sensation 4 scanner with 120 kV and 50 mAs, 50 ml of nonionic contrast agent (320 mg I/ml) was injected at a flow rate of 4 ml/s with a power injector, Scan started after 8 seconds delay and data acquisition duration was 50 seconds. The blood flow ( BF), blood volume (BV) and mean transfer time (MTT) of lesion and contralateral normal breast gland were calculated using Basama perfusion 3 software package before and after chemotherapy. At the same time, the tumor size before and after chemotherapy were measured and correlated with the BF values. The t test and non-parametric test were used for the statistics. Results ( 1 ) The mean BF、BV and MTT of breast cancer were (33.20±4. 17) ml · min-1 · 100 ml-1 , (8. 31±2.43) ml · 100 ml-1 and ( 15. 31 ± 4. 31 ) s respectively before chemotherapy, and ( 13.65 ± 6. 04) ml · min-1 100 ml-1, (5.04±2. 33) ml · 100 ml-1 and (25. 97±9. 07) s respectively after chemotherapy and there were statistically significant (P =0. 000). The mean BF、BV and MTT of normal breast were (4. 31 ± 2.23) ml · min-1 · 100 ml-1, (1.38±0.75) ml · 100 ml-1 and (19.25±3.94) s respectively before chemotherapy, and (4.03±2.35) ml · min-1 · 100 ml-1、(1.44±0.84) ml · 100 ml-1、(22.56 ± 7.71 ) s respectively after chemotherapy and there were not statistically significant (P >0. 05). (2)The BF of breast cancer was higher than the normal breast before chemotherapy ( P < 0. 01 ). (3) There was a positive correlation between the BF values and tumor size before and after chemotherapy ( r = 0. 902, P = 0. 000). Conclusion The BF value has a positive correlation with tumor size after chemotherapy, CT perfusion is more sensitive for the evaluation of chemotherapy response than morphologic assessment.

Objective:To investigate the value of 18F-PSMA PET/CT-derived prostate specific membrane antigen(PSMA)expression parameters, including maximum standardize uptake value(SUV max), PSMA receptor expressing tumor volume(PSMA-TV), and total lesion PSMA receptor expression(TL-PSMA), in predicting the risk of metastasis in elderly prostate cancer patients aged 60 years and older. Methods:Clinical data of 39 patients with prostate cancer diagnosed in our hospital from January 2019 to May 2021 and imaging data of 18F-PSMA PET/CT before treatment were analyzed retrospectively.PSMA-TV and TL-PSMA of primary tumor tissue were calculated from PET/CT images with 40% of the SUV max as the threshold value.The influence of 18F-PSMA PET/CT on clinical TNM staging was evaluated.The Mann-Whitney U test was used to compare the differences in values of various indicators between the groups with or without metastasis, including the total prostate-specific antigen(tPSA)level, Gleason score and PSMA expression parameters.The correlation of PSMA expression parameters with tPSA and Gleason score was analyzed.The area under the receiver operating characteristic(ROC)curve(AUC)was used to determine the predictive ability of different indicators for the risk of prostate cancer metastasis, and multivariate logistic regression analysis was used to screen for independent predictors of prostate cancer metastasis. Results:The Gleason score of 39 prostate cancer patients(median age: 67 years, age range: 60-83 years)was 7.0(7.0, 8.0), and the median prostate specific antigen(PSA)level was 14.83(7.37, 30.93)μg/L.There were 11 cases(28.2%)with metastasis(the metastasis group), and 28 cases(71.8%)without metastasis(the non-metastasis group). Based on PET/CT, the clinical N and M stages of five patients(12.8%)were changed, but two cases(5.1%)with pelvic lymph node metastasis were missed.The median ages of the metastasis group and the non-metastasis group were 63(60-79)years and 69(60-83)years, respectively, and the difference was not statistically significant( P=0.115). The metastasis group and the non-metastasis group had tPSA levels at 54.0(9.9, 75.8)μg/L and 10.2(6.8, 22.8)μg/L, the SUV max at 29.1(16.8, 35.3)and 7.7(6.0, 13.6), the PSMA-TV at 41.5(22.4, 90.9)cm 3 and 6.8(3.6, 9.3)cm 3, TL-PSMA at 279(139.7, 996.4)and 25.5(15.9, 37.0), Gleason scores at 8.0(7.0, 8.0)and 7.0(7.0, 8.0), respectively.There were statistically significant differences in tPSA( Z=-2.528, P=0.011), SUV max( Z=-4.151, P<0.001), PSMA-TV( Z=-3.995, P<0.001)and TL-PSMA( Z=-4.213, P<0.001)between the two groups.SUV max( r=0.537, P<0.01), PSMA-TV( r=0.496, P<0.01)and TL-PSMA( r=0.508, P<0.01)were all positively correlated with tPSA.Furthermore, SUV max( r=0.547, P<0.01), PSMA-TV( r=0.412, P<0.01)and TL-PSMA( r=0.433, P<0.01)were also positively correlated with Gleason score.ROC curve analysis showed that the AUCs of SUV max, PSMA-TV, TL-PSMA and tPSA in predicting prostate cancer metastasis were 0.932, 0.916, 0.938 and 0.763, respectively.Multivariate Logistic regression analysis showed that SUV max( OR=1.203, 95% CI: 1.001-1.445, P=0.049)was an independent predictor of prostate cancer metastasis. Conclusions:These PSMA expression parameters of 18F-PSMA PET/CT have a good value in predicting the risk of metastasis in elderly prostate cancer patients, and SUV maxmay serve as a potential molecular imaging indicator to independently predict prostate cancer metastasis.

Objective:To investigate the relationships between severe, diffuse decrease in global brain 18F-fluorodeoxxglucose(FDG)uptake, whole-body total lesion glycolysis(TLG)and short-term death in elderly patients with newly diagnosed stage Ⅳ cancer. Methods:Clinical and 18FFDG PET/CT data of 24 elderly patients newly diagnosed stage Ⅳ cancer showing marked diffuse decrease in global brain FDG uptake(the decreased brain uptake group)were retrospectively enrolled.Sixteen elderly patients with newly diagnosed stage Ⅳ cancer but without decreased global brain FDG uptake(the no decreased brain uptake group)and 25 healthy subjects were enrolled as the control groups.Correlations between brain FDG uptake and whole-body TLG were analyzed.We followed up the final outcomes of all patients and analyzed the short-term prognostic value of these manifestations. Results:The decreased brain uptake group included 17 patients with stage Ⅳ lymphoma and 7 patients with stage Ⅳ malignant tumor of other types[15 males, age: (73±9)years], while the no decreased brain uptake group included 8 patients with stage Ⅳ lymphoma and 8 patients with stage Ⅳ malignant tumor of other types[12 males, age: (65±5)years]and the healthy control group included 25 subjects[13 males, age: (65±6)years]. Patients were older in the decreased brain uptake group than in the no decreased brain uptake group( t=3.8, P=0.001). The global brain SUV means of the decreased brain uptake group and the no decreased brain uptake group were 4.9±1.8 and 10.9±2.0, respectively( t=-9.8, P=0.000). The global brain total glycolysis(TG)values of the two groups were 1786.5±1162.5 and 2868.4±1424.5, respectively( t=-2.6, P=0.012). The whole-body TLG values of the two groups were 6825.5±4776.9 and 2919.5±2031.7, respectively( t=3.6, P=0.001). Pearson correlation analysis showed that brain FDG uptake was adversely correlated with whole-body TLG.We followed up the survival outcomes of the two groups.The median follow-up lengths of the two groups were 6 months and 10 months, respectively( χ2=3.7, P=0.054). Fourteen(14/24)patients died in the decreased brain uptake group while 9(9/16)died in the no decreased brain uptake group( χ2=0.017, P=0.896). However, 8 cases died within 1 month post PET/CT scan in the decreased brain uptake group while none died in the no decreased brain uptake group( χ2=4.7, P=0.029). Conclusions:Severe, diffuse decrease in 18F-FDG PET/CT uptake in the whole cerebral cortex is more common in elderly patients with newly diagnosed stage Ⅳ cancer, whose total tumor load is significantly higher than that of cancer patients without decrease in whole cerebral cortex FDG uptake.This uptake reduction may indicate poor short-term outcome and the probability of short-term death may be high.

Objective:To study the value of ventilation/perfusion single-photon emission computed tomography(SPECT)in combination with a low-dose CT scan(SPECT/CT)in diagnosing pulmonary embolism(PE)in elderly patients.Methods:In this retrospective study, data were collected from 279 patients with suspected PE and undergone SPECT/CT between January 2015 and December 2019 at Beijing Hospital, with 163 aged ≥65(the elderly group)and 116 aged <65(the control group). Based on diagnosis confirmed during follow-up as the final diagnosis, the diagnostic efficacy of ventilation/perfusion SPECT/CT in the two age groups was examined.The diagnostic efficacy of ventilation/perfusion SPECT/CT and age-adjusted D-dimer in the elderly group was also compared.The diagnostic efficacy of ventilation/perfusion SPECT/CT and CT pulmonary angiography(CTPA)was compared in 43 elderly patients who had undergone both ventilation/perfusion SPECT/CT and CTPA.Results:The sensitivity, specificity and accuracy of ventilation/perfusion SPECT/CT in the elderly group were 96.10%(74/77), 91.86%(79/86)and 93.87%(153/163)in the elderly group and 96.43%(27/28), 94.31%(83/88)and 94.83%(110/116)in the control group, respectively, with no statistically significant difference between the two groups( χ2=0.000, 0.409, 0.116, P=1.000, 0.522, 0.733). The sensitivity, specificity and accuracy of age-adjusted D-dimer were 84.42%(65/77), 63.95%(55/86)and 73.62%(120/163), and were significantly different from those of ventilation/perfusion SPECT/CT(all P<0.05). Among 43 elderly patients undergone ventilation/perfusion SPECT/CT and CTPA, 1 was excluded because the diagnosis based on CTPA was uncertain.The diagnostic sensitivity, specificity and accuracy of ventilation/perfusion SPECT/CT were 96.55%(28/29), 92.31%(12/13)and 95.24%(40/42)and those of CTPA were 65.52%(19/29), 92.31%(12/13)and 73.81%(31/42). They had the same specificity, but there were significant differences in sensitivity and accuracy( P=0.012, 0.022). Conclusions:Ventilation/perfusion SPECT/CT has higher accuracy in the diagnosis of PE in elderly patients, compared with CTPA and age-adjusted D-dimer.

¹⁷⁷Lu- prostate specific membrane antigen (PSMA) radio-ligand therapy has been approved abroad for advanced prostate cancer and has been in several clinical trials in China. Based on domestic clinical practice and experimental data and referred to international experience and viewpoints, the expert group forms a consensus on the clinical application of ¹⁷⁷Lu-PSMA radio-ligand therapy in prostate cancer to guide clinical practice.