[en] Objective: To summarize the clinical and CT features of liver abscess, and to evaluate the clinical effect of percutaneous catheter drainage in treating liver abscess. Methods: A total of 578 patients with liver abscess, who were admitted to authors' hospital during the period from Jan. 2000 to May 2012, were enrolled in this study. The clinical data and the CT findings were retrospectively analyzed. CT features used for analysis included the number of lesion, unilocular or multilocular appearance, cystic or solid in nature, gas in cavity, etc. The factors which might influence the therapeutic effect were analyzed. And the factors influencing the hospitalization days and drainage time were also explored. The results were statistically analyzed by using independent-sample t-test, χ² test and Fisher's exact test with the software of SPSS version 16.0. Results: The main clinical symptoms were fever and pain in the right upper quadrant of abdomen. Infective shock was seen in 52 cases (9.0%) and hematogenous infection was complicated in 80 cases (13.8%). Laboratory studies showed that the main abnormalities included increase of white blood cell and neutrophil percentage, decrease of albumin level, elevated liver enzymes, increased total bilirubin, increase of C-reaction protein, etc. Positive bacteria culture of blood or pus was found in 416 patients (71.9%), and the main pathogen was Klebsiella pneumoniae (69.7%). Technical success rate of percutaneous catheter drainage for liver abscess was 99.7%, while the clinical success rate was 97.4% with a mortality rate of 0.9%. Complications occurred in 5 patients (0.9%). The mean hospitalization day was (13.1 ± 7.4) days, and the average drainage time was (29.2 ± 9.3) days. The factors that influenced the hospitalization day were abscess containing gas, complications such as infective shock, infection at other sites, concomitant hepatobiliary and pancreatic malignant tumor, etc. The factors that influenced the drainage time included multilocular lesion, solid lesion, concomitant hepatobiliary and pancreatic malignant tumor, etc. Concomitant hepatobiliary and pancreatic malignant tumor was the only factor that influenced the clinical success rate. Conclusion: For the liver abscess, percutaneous drainage should be recommended as the treatment of first choice provided that there is no concomitant hepatobiliary or pancreatic malignant tumor. Factors such as multilocular, solid or gas-containing lesion, concomitant infection or infective shock will not affect the clinical success rate although they can elongate the hospitalization time and drainage time. (authors)

[en] Objective: To investigate the risk factors of upper digestive tract massive bleeding caused by esophageal stent placement for malignant diseases, and to analyze the correlation between the risk factors and the occurrence of bleeding. Methods: A total of 235 patients with malignant esophageal stenosis or fistula, who were encountered in authors' hospital during the period from Jan. 2005 to June 2011, were enrolled in this study. Esophageal stent placement was performed in all patients. After the treatment, the patients were divided into bleeding group and non-bleeding group based on the occurrence of lethal massive bleeding of upper digestive tract. The age, gender, location of tumor, stent type, stent position, simultaneous use of radiotherapy, presence of esophageal fistula, tracheal stent placement, etc. were documented. The data were compared between the two groups, and their correlations were analyzed. Results: Lethal hemorrhage occurred in 6.8% cases (16/235), which presented as profuse hematemesis, and the patient died in a short period. The difference in the presence of esophageal fistula was statistically significant between the two groups, while no significant difference in other factors (age, gender, location of tumor, stent type, stent position, simultaneous use of radiotherapy, tracheal stent placement) existed between the two groups. Multivariate regression analysis indicated that a significant correlation existed between the presence of esophageal fistula and the occurrence of massive postoperative bleeding. Conclusion: The presence of esophageal fistula is the most important risk factor causing upper digestive tract massive bleeding after esophageal stent placement. (authors)

[en] Objective: To explore the value of 70 keV virtual monoenergetic images (VMI) on dual-layer spectral detector CT in improving abdominal arterial phase images quality. Methods: The arterial phase images of patients who underwent abdominal enhanced scan on the Philips IQon dual-layer spectral detector CT in Shengjing Hospital of China Medical University from January to May 2019 were retrospectively analyzed. Fifty patients (12 males, 38 females) were included with age of 26-74 (53 ± 12) years. Objective and subjective evaluation was performed in 120 kVp polychromatic conventional images (group CI) which derived from iterative reconstruction algorithm and group 70 keV VMI which derived from spectral reconstruction algorithm. The attenuation, noise, signal to noise ratio and contrast to noise ratio of abdominal aorta, celiac trunk, superior mesenteric artery, left kidney artery, right kidney artery, liver, spleen, pancreas, left and right kidney were compared between group 70 keV VMI and CI by using paired;t test. Image quality of group 70 keV VMI and CI was evaluated by two radiologists independently with a 5-point scale and compared by Wilcoxon rank test. The inter-agreement of subjective scoring between the two radiologists was evaluated by Kappa test. Results: Except for pancreas, the attenuation of abdominal arteries and solid organs in group 70 keV VMI were higher than that of group CI and the difference was statistically significant (P all < 0.05). The attenuation of pancreas was lower than that of group CI (t = -3.097, P = 0.003). The noise of abdominal arteries and solid organs in group 70 keV VMI showed lower values compared to group CI and the difference was statistically significant (P all < 0.001). The signal to noise ratio as well as contrast to noise ratio of abdominal arteries and solid organs in group 70 keV VMI was higher than that of group CI and the difference was statistically significant (P all < 0.001). Subjective image quality scores in group 70 keV VMI were higher than that of group CI and scores of group 70 keV VMI and CI were 5 (4, 5) and 4 (4, 5), respectively. The difference was statistically significant (Z = -4.131, P < 0.001). There was a good consistency of subjective image quality scores between two radiologists, which Kappa values of group 70 keV VMI and CI were 0.79 and 0.69, respectively. Conclusions: Compared to CI, 70 keV VMI derived from dual-layer spectral detector CT can optimize abdominal arterial phase image quality by decreasing the noise, improving the signal to noise ratio and contrast to noise ratio. (authors)

[en] Objective: To systematically assess the diagnostic performance of CTA for lower extremity peripheral arterial disease (PAD) using a Meta analysis method. Methods: Studies were located through electronic searching of the PubMed, EBSCO, Springer, Ovid, CNKI, Cochrane library (from the date of establishment of the databases to October 2009). Bibliographies of the retrieved articles were also checked. All the studies concerning the diagnosis of PAD using CTA had been searched and reviewed, and the studies with the DSA as the gold standard were adopted as eligible. Subsequently, the characteristics of the included articles were appraised and extracted. Data on accuracy of included studies were extracted for further heterogeneity exploring, statistical pooling and SROC (summary receiver operating characteristics) analyzing using the Meta Disc 1.4 software. Results: Totally 24 studies met the inclusion criteria with a total of 1096 patients. The heterogeneity was found in these studies. The pooled accuracy indicators like sensitivity, specificity, and diagnostic odds ratio (DOR) were 0.95 (95% CI: 0.94-0.95), 0.96 (95% CI: 0.95-0.96), and 471.13 (95% CI: 242.92-913.71), respectively. The area under of SROC curve was 0.9888 and the Q index was 0.9555. Subgroup analysis demonstrated significant difference on diagnostic performance for various CT slices (P<0.05). Conclusion: CTA can be regarded as an effective and feasible method for PAD diagnosis and screening, based on the results of this systematic review. However, more rigorous evaluations of CTA in patients with critical limb ischemia are needed. (authors)

[en] Objective: To evaluate the application of early ¹⁸F-FDG PET-CT imaging after radiofrequency ablation (RFA) of hepatic malignancies. Methods: Fifteen patients with liver tumors (five hepatocellular carcinoma, ten colorectal cancer liver metastasis) underwent RFA as part of clinical management. The lesions were all hypermetabolic on PET-CT performed within 2 weeks prior to RFA. All subjects underwent ¹⁸F-FDG PET-CT (early PET-CT) within 24 hours after RFA. Total photopenia, focal uptake, and rim-shaped uptake were regarded as complete ablation, residual tumor, and inflammation, respectively. Follow-up PET-CT scans were performed as the reference standard. Results: Twelve patients showed total photopenia at the ablation site on the early PET-CT scan, and in all of these patients, total photopenia at the ablation sites was seen on the follow-up PET-CT scans. Two patients had focal uptake at the ablation sites on the early PET-CT scan, and both of these foci increased in size and intensity, which were compatible with residual tumors at the time of ablation. Only one patient had rim-shaped uptake on the early PET-CT scan. The rim-shaped uptake disappeared on PET-CT performed 3 months later, which indicated the nature of inflammation. Conclusions: There is infrequent inflammatory uptake at the RFA site of liver tumors on ¹⁸F-FDG PET-CT if scanning is performed within 24 hours after ablation. Thus, early PET- CT has the potential to evaluate the efficacy of an RFA procedure by indicating tumor-free as total photopenia and residual tumors as focal uptake. (authors)

[en] Objective: To evaluate the safety and effectiveness of interventional treatment for pelvic lymphocele associated with deep vein thrombosis (DVT) of lower extremity after the operation for gynecologic malignant tumor. Methods: During last five years, a total of 12 patients with pelvic lymphocele associated with DVT of lower extremity after the operation for gynecologic malignant tumor received interventional treatment. The clinical data were retrospectively analyzed. The interventional procedures included catheter drainage, injection of hardening agent, implantation and retrieval of inferior vena cava filter, lower extremity vein stenting, etc. After the treatment, the patients were kept under close observation for the occurrence of serious complications and the improvement of clinical symptoms. Color Doppler ultrasonography and CT scan were employed to check the therapeutic results. Results: Inferior vena cava filter placement was performed in 12 patients, which was followed by puncture drainage of pelvic lymphocele; a total of 18 times of puncture drainage were carried out, including bilateral procedures in 5 patients, unilateral procedure in 7 patients and two times of puncture drainage in one patient. Filter retrieval was performed in 7 patients. In one patient, puncture of femoral artery was employed, and puncture of femoral artery was repeated after oppression hemostasis for 24 hours. Occlusion of drainage tube occurred in one patient, the occlusion was improved after replacement of the drainage tube. Left iliac vein stenting was adopted in one patient. After the treatment, in all patients no severe complications such as hemorrhage or pulmonary embolism occurred, and the clinical symptoms disappeared or were obviously improved. The patients were followed up for 3-47 months with a median time of 16 months. No recurrence of pelvic lymphocele was observed in all patients. Conclusion: For the treatment of lymphocele associated with DVT of lower extremity, interventional therapy is safe and effective. (authors)

[en] Objective: To evaluate dynamic CT and PET-CT features of normal dog liver after radiofrequency ablation (RFA) correlated with the time-related histopathological changes. Methods: Fifteen hybrid adult dogs in good health condition were evenly divided into 5 groups (the immediate, 1 st, 2 nd, 4 th and 8 th week group) according to random digits table methods. Twice RFA was performed for each group. All dogs were executed through intravenous injection of klorvess liquid after scanning. Liver samples were histologically examined. All images were assessed to determine the ratios (r_p/p) which referred to the comparison of rimlike enhancement or tracer uptake in the periphery of the necrosis to that in normal liver parenchyma. Those imaging results were compared and correlated with histopathological findings. Results: For the immediate group after RFA procedure, central ablation lesions appeared coagulation necrosis and surrounding sinusoids engorged with blood. On the images of enhanced CT, marked rimlike enhancement was noticed in peripheral ablation lesions. While PET-CT showed decreased ¹⁸F-FDG uptake surrounded by homogeneous tracer distribution. For the 1 st-4 th week group, central necrosis was gradually getting more severe. Infiltration of the inflammatory cells, granulation tissue formation and fibrous tissue restoration were noticed in peripheral ablation lesions. Rimlike enhancement and increased glucose metabolism appeared surrounding the lesions on CT and PET-CT, especially in the 1 st to 2nd week groups. For the 8 th week group after RFA, the enhancement or hypermetabolism metioned above disappeared when perilesional tissue regeneration became more obvious. From the dynamic curve of changes on enhanced CT, marked enhancement occurred in the immediate group after ablation (r_p/p =1.34 ± 0.21), reached its peak at the 1 st week group (r_p/p =1.39 ± 0.20), and then declined gradually. The metabolic changes on PET-CT showed a typical single peak curve, with the peak at the 1 st week group (r_p/p =1.19 ± 0.09) and similar even metabolism at the immediate and 8 th week group. Conclusions: Both CT and PET-CT imaging can well correlate with the histopathological changes after RFA in the normal liver. To avoid the interference of inflammatory reaction when differentiating normal liver tissue from residual tumor, it is better to take radiology examination immediately and 8 weeks after RFA. PET-CT probably has advantages over CT immediately after RAF. After 1 week, PET-CT and CT may have similar diagnostic efficacy. (authors)

[en] Klebsiella pneumoniae liver abscess (KPLA) complicated with extrahepatic migratory infection (EMI) is defined as invasive KPLA. The current study aimed to develop and validate a risk prediction model for the invasiveness of KPLA. From 2010 to 2020, KPLA patients from four institutes were selected retrospectively. In the development cohort, risk factors from a logistic regression analysis were utilized to develop the prediction model. External validation was performed using an independent cohort. A total of 382 KPLA patients comprised two separate cohorts: development cohort (institute 1, n = 286) and validation cohort (institute 2-4, n = 86). The overall incidence of EMI was 19.1% (development cohort, n = 55; validation cohort, n = 18, p > 0.05). In the development cohort, four risk factors (age ≤ 40 years, fasting blood glucose (FBG) > 7 mmol/L, no rim enhancement, and thrombophlebitis on CT), significantly associated with EMI, were incorporated into the scoring system. The area under curve (AUC) of the receiver operating characteristic curve (ROC) in the development and validation cohorts was 0.931 (95% confidence interval [CI]: 0.93–0.95) and 0.831 (95% CI: 0.86–0.91), respectively. The calibration curves fitted well. The incidence of EMI was 3.3% and 56.5% for the low- (total scores ≤ 4) and high-risk (total scores > 4) groups in the development cohort, and 3.2% and 66.7% in the validation cohort (all p < 0.001), respectively. Age ≤ 40 years, FBG > 7 mmol/L, no rim enhancement, and thrombophlebitis were independent risk factors for EMI. This validated prediction model may aid clinicians in identifying KPLA patients at increased risk for invasiveness. Four risk factors are significantly associated with extrahepatic migratory infections (EMI): age ≤ 40 years, fasting blood glucose (FBG) > 7 mmol/L, no rim enhancement, and thrombophlebitis on CT. Based on these risk factors, the current study developed and validated a prediction model for the invasiveness of Klebsiella pneumoniae liver abscess (KPLA). This validated prediction model may in the help early identification of KPLA patients at increased risk for invasiveness.