OBJECTIVE: To explore the high-risk fault risk of CT simulator and the main causes of the risk, and to put forward effective risk management strategies. METHODS: The failure mode and effect analysis method was used to identify and control the operational fault risk of CT simulator. RESULTS: 5 major fault components, 8 fault failure models and 17 failure causes were analyzed. The top 5 failure causes are:anode target surface burn caused by direct scanning without warming up the tube (590.4), tube failure (518.2), burnout of joints caused by aging of high voltage cables (424.2), motor carbon brush wear (304.8) and belt break (296.4). CONCLUSIONS The failure mode and effect analysis method can effectively identify the risk of equipment failure, and thus specifically formulate risk management and control measures to ensure the normal operation of equipment and the safety of doctors and patients.
Equipment Failure ; statistics & numerical data ; Humans ; Risk Management ; methods ; Tomography, X-Ray Computed ; standards

Accidents, Traffic ; statistics & numerical data ; Adolescent ; Age Distribution ; Bicycling ; injuries ; Child ; Child, Preschool ; Cohort Studies ; Emergency Service, Hospital ; statistics & numerical data ; Female ; Follow-Up Studies ; Fracture Fixation ; methods ; statistics & numerical data ; Fractures, Bone ; diagnosis ; epidemiology ; surgery ; Humans ; Injury Severity Score ; Male ; Prevalence ; Radiography ; methods ; Registries ; Retrospective Studies ; Risk Assessment ; Sex Distribution ; Singapore ; epidemiology ; Tomography, X-Ray Computed ; methods ; Trauma Centers ; Treatment Outcome ; Wounds and Injuries ; diagnostic imaging ; epidemiology ; therapy

OBJECTIVETo evaluate the diagnostic value of preoperative CT enterography (CTE) on obstruction, fistula and abscess formation compared to intraoperative findings in patients undergoing surgery for Crohn's disease(CD), aiming to provide reference to clinical practice.

METHODSPreoperative CTE data of 176 CD patients confirmed by clinic, endoscopy, imaging, operation and pathology at the Department of General Surgery in Nanjing Jinling Hospital from January 2013 to December 2015 were enrolled in retrospective cohort study. All the patients underwent enhanced full abdominal CT scan using SIMENS SOMATOM Definition Flash 64 row dual-source CT machine. CTE scans were performed from the dome of diaphragm to the symphysis pubis. The CT images in arterial and venous phase were reconstructed with 1.0 mm thin layer, and then processed in MMWP 4.0 workstation including multi-planar recombination, surface recombination and maximum density projection. The sensitivity, specificity, positive and negative predictive value, false negative rate and accuracy of preoperative CTE on obstruction, fistula and abscess were compared with intraoperative findings.

RESULTSAmong 176 patients, 122 were males and 54 were females with median age of 29 (18 to 65) years, median disease duration of 48 (1 to 240) months, median time interval from CT scan to operation of 16(1 to 30) days, and median body mass index of 17.8 (10.8 to 34.7) kg/m. Twenty-six cases (14.8%) had nutritional risk (NRS2002≥3); 23 cases (13.1%) had lesions limited to ileum; 19 cases (10.8%) had lesions limited to colon; 126 cases (71.6%) had simultaneous lesions of ileum and colon, and 8 cases (4.5%) had lesion in upper gastrointestinal tract. A total of 199 lesions of small intestine were identified by preoperative CTE, including 131 of obstruction (65.8%), 42 of fistula (21.1%), and 26 of abscess (13.1%), while 235 lesions were confirmed by operation, including 133 of obstruction (56.6%), 74 of fistula (31.5%), 28 of abscess (11.9%). The modification of planned surgical procedure due to unexpected intraoperative findings were found in 29(16.5%) patients. The sensitivity, specificity, positive predictive value and negative predictive value of preoperative CTE were 86.4%, 78.8%, 86.9% and 76.0% for obstruction; 83.8%, 79.1%, 67.5% and 90.4% for fistula; and 96.2%, 98.0%, 90.1% and 99.3 for abscess, respectively.

CONCLUSIONPreoperative CTE can effectively evaluate the lesions of intestinal obstruction, fistula and abscess in CD patients, with the highest accuracy of abscess, and has quite good consistency with intraoperative findings, which may be used as the first choice of imaging diagnosis of CD.

Abscess ; diagnostic imaging ; Adult ; Aged ; Colon ; diagnostic imaging ; surgery ; Crohn Disease ; diagnostic imaging ; surgery ; Female ; Humans ; Ileum ; diagnostic imaging ; surgery ; Intestinal Fistula ; diagnostic imaging ; Intestinal Obstruction ; diagnostic imaging ; Intestine, Small ; diagnostic imaging ; surgery ; Male ; Middle Aged ; Radiography, Abdominal ; methods ; statistics & numerical data ; Retrospective Studies ; Sensitivity and Specificity ; Tomography, X-Ray Computed ; methods ; statistics & numerical data

BACKGROUND: Early stage osteonecrosis of the femoral head (ONFH) has many treatment options including core decompression with implantation of a tantalum rod. The purpose of this study was to evaluate clinical and radiological outcomes and potential complications during conversion total hip arthroplasty (THA) in such patients. METHODS: Six male patients (8 hips) underwent THA subsequent to removing a tantalum rod (group I) from April 2010 to November 2011. We retrospectively reviewed the medical records of these patients. We enrolled 12 age- and sex-matched patients (16 hips) during the same period, who had undergone primary THA without a previous operation as the control group (group II). All patients were followed for at least 3 years. We checked the Harris hip score (HHS), operative time, and volume of blood loss. Radiological results, including inclination, anteversion of the acetabular cup, presence of periprosthetic osteolysis, and subsidence of femoral stem were checked at the last follow-up. RESULTS: The mean preoperative HHS values were 56.5 (range, 50 to 62) and 59.1 (range, 42 to 70) in groups I and II, respectively. The HHS improved to 96.0 (range, 93 to 100) and 97.6 (range, 93 to 100), respectively, at the 3-year follow-up (p = 0.172). Mean operation time was 98.8 minutes (range, 70 to 120 minutes) in group I and 77.5 minutes (range, 60 to 115 minutes) in group II (p = 0.006). Total blood loss volumes were 1,193.8 mL (range, 960 to 1,360 mL) and 944.1 mL (range, 640 to 1,280 mL) in groups I and II, respectively (p = 0.004). No significant differences in inclination or anteversion of acetabular cup and no evidence of osteolysis or subsidence of the femoral stem were reported in either group in radiological follow-up results. However, one case of squeaking occurred in group I during the follow-up. CONCLUSIONS: The two groups showed no clinical or radiological differences except extended operative time and increased blood loss. However, the incidence of squeaking (1 of 8 hips) was higher, as compared to the control group or previously reported values.
Adult ; *Arthroplasty, Replacement, Hip/adverse effects/methods/statistics & numerical data ; Case-Control Studies ; *Decompression, Surgical/adverse effects/methods/statistics & numerical data ; Femur Head/diagnostic imaging/surgery ; Femur Head Necrosis/diagnostic imaging/*surgery ; Humans ; Male ; Postoperative Complications ; Reoperation ; Retrospective Studies ; Tantalum/*therapeutic use ; Tomography, X-Ray Computed ; Treatment Outcome

To investigate the correlations among total liver CT perfusion parameters, unpaired arteries (UAs) and microvessel area (MVA) in a rabbit liver VX2 tumor model, and to learn the tumoral angiogenesis condition and the mechanisms for perfusion imaging.
 Methods: Rabbits with or without the inoculated VX2 tumor in the liver underwent total liver CT perfusion imaging 2 weeks after the operation. Perfusion parameters included blood flow (BF), blood volume (BV), arterial liver perfusion (ALP), portal liver perfusion (PVP), hepatic perfusion index (HPI) for the tumor rim and the surrounding liver tissue. After the examination, the UAs and MVA of tumor tissues were obtained by immunohistochemical staining. The differences of perfusion parameters between the vital tumor rim and the surrounding liver tissue were compared. The correlations among perfusion parameters, UAs and MVA were analyzed.
 Results: There was significant difference between the CT perfusion parameters at the tumor rim and the surrounding liver tissue or liver tissue of the control group (P<0.05), but there was no significant difference between the perfusion parameters at the surrounding liver tissues of the experimental group and the control (P>0.05). There was positive correlation between UAs and MVA. UAs and MVA were positively correlated with BF, ALP and BV at the tumor rim. UAs and MVA were negatively correlated with PVP. HPI positively correlated with UAs, but it was not correlated with MVA.
 Conclusion: Total liver CT perfusion can provide quantitative information to evaluate the artery and portal vein perfusion of liver VX2 tumor, and to assess the degree of tumor angiogenesis.
Animals ; Arteries ; diagnostic imaging ; Blood Volume ; Carcinoma ; Immunohistochemistry ; Liver Circulation ; Liver Neoplasms ; blood supply ; diagnostic imaging ; Microvessels ; diagnostic imaging ; Neoplasm Transplantation ; Neoplasms, Squamous Cell ; Neovascularization, Pathologic ; diagnostic imaging ; Perfusion Imaging ; statistics & numerical data ; Portal System ; diagnostic imaging ; Rabbits ; Tomography, X-Ray Computed ; methods ; statistics & numerical data

A new CT-based diagnostic method of protrusio acetabuli (PA) was introduced. However, prevalence of PA by this method and correlation between PA and other manifestations of Marfan syndrome (MFS) is unknown in Korean MFS patients. This study aimed to investigate the prevalence of PA diagnosed by a CT-based method in Korean patients with MFS, the association of PA with other manifestations of MFS, and the contribution of PA to MFS diagnosis. We retrospectively reviewed the records of 146 MFS patients with the presence of a causative FBN1 mutation and 146 age- and sex-matched controls from a single tertiary care center. All MFS patients underwent a complete assessment of criteria based on the revised Ghent nosology. PA was assessed quantitatively using a CT-based circle-wall distance (CWD) method. PA was diagnosed in 77.4% of patients in the MFS group and in 11.0% of the control group. CWD was significantly different between the two groups (1.50 mm vs. -0.64 mm, P<0.001). The presence of PA did not correlate with the presence of ectopia lentis, aortic root diameter, or history of aortic dissection. The presence of PA did not have a significant impact on the final diagnosis of MFS. Even though the presence of PA does not related to the cardinal clinical features of MFS or influence MFS diagnosis, its presence may be helpful for the suspicion of MFS when aortic dissection or aneurysm is found on CT angiography of the aorta because of the high frequency of PA in MFS patients.
Acetabulum/*abnormalities/radiography ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Aortic Aneurysm/*epidemiology/radiography ; Comorbidity ; Female ; Humans ; Male ; Marfan Syndrome/*epidemiology/*radiography ; Middle Aged ; Prevalence ; Reproducibility of Results ; Republic of Korea/epidemiology ; Risk Factors ; Sensitivity and Specificity ; Tomography, X-Ray Computed/*methods/*statistics & numerical data ; Young Adult

PURPOSE: To investigate the usefulness of urine cytology in the detection of tumor recurrence in terms of practicality and cost-effectiveness. MATERIALS AND METHODS: We retrospectively analyzed 393 patients who underwent transurethral resection of bladder tumor (TURBT) for non-muscle-invasive bladder cancer (NMIBC) from January 2010 to June 2013. All patients underwent cystoscopy, urine cytology, urinalysis, and computed tomography (CT) at 3 and 6 months after TURBT. In 62 cases, abnormal bladder lesions were identified on cystoscopy within 6 months. Suspicious lesions were confirmed pathologically by TURBT or biopsy. Patients were grouped by modalities: group I, urine cytology; group II, CT; group III, urinalysis; group IV, urine cytology plus CT; group V, urine cytology plus urinalysis; group VI, CT plus urinalysis; group VII, combination of all three modalities. Each group was compared by cost per cancer detected. RESULTS: Forty-nine patients were confirmed to have tumor recurrence and 13 patients were confirmed to have inflammation by pathology. The overall tumor recurrence rate was 12.5% (49/393) and recurrent cases were revealed as NMIBC. Sensitivity in group I (24.5%) was lower than in group II (55.1%, p=0.001) and group III (57.1%, p<0.001). However, in group VII (77.6%), the sensitivity was statistically similar to that of group VI (75.5%, p=0.872). Under the Korean insurance system, total cost per cancer detected for group VII was almost double that of group VI (p=0.041). CONCLUSIONS: Routine urine cytology may not be useful for follow-up of bladder cancer in terms of practicality and cost-effectiveness. Application of urine cytology needs to be adjusted according to each patient.
Aged ; Aged, 80 and over ; Cost-Benefit Analysis ; Cystoscopy/economics ; Cytodiagnosis/economics/methods ; Female ; Health Care Costs/*statistics & numerical data ; Humans ; Male ; Middle Aged ; Neoplasm Recurrence, Local/*diagnosis/economics/pathology ; Neoplasm Staging ; Republic of Korea ; Retrospective Studies ; Sensitivity and Specificity ; Tomography, X-Ray Computed/economics ; Urinalysis/economics/methods ; Urinary Bladder Neoplasms/*diagnosis/economics/pathology/surgery ; Urine/*cytology

OBJECTIVE: To determine whether non-linear blending technique for arterial-phase dual-energy abdominal CT angiography (CTA) could improve image quality compared to the linear blending technique and conventional 120 kVp imaging. MATERIALS AND METHODS: This study included 118 patients who had accepted dual-energy abdominal CTA in the arterial phase. They were assigned to Sn140/80 kVp protocol (protocol A, n = 40) if body mass index (BMI) < 25 or Sn140/100 kVp protocol (protocol B, n = 41) if BMI > or = 25. Non-linear blending images and linear blending images with a weighting factor of 0.5 in each protocol were generated and compared with the conventional 120 kVp images (protocol C, n = 37). The abdominal vascular enhancements, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and radiation dose were assessed. Statistical analysis was performed using one-way analysis of variance test, independent t test, Mann-Whitney U test, and Kruskal-Wallis test. RESULTS: Mean vascular attenuation, CNR, SNR and subjective image quality score for the non-linear blending images in each protocol were all higher compared to the corresponding linear blending images and 120 kVp images (p values ranging from < 0.001 to 0.007) except for when compared to non-linear blending images for protocol B and 120 kVp images in CNR and SNR. No significant differences were found in image noise among the three kinds of images and the same kind of images in different protocols, but the lowest radiation dose was shown in protocol A. CONCLUSION: Non-linear blending technique of dual-energy CT can improve the image quality of arterial-phase abdominal CTA, especially with the Sn140/80 kVp scanning.
Adult ; Aged ; Angiography/*methods ; Body Mass Index ; Female ; Humans ; Male ; Middle Aged ; Observer Variation ; Radiation Dosage ; Radiographic Image Enhancement/methods ; Radiographic Image Interpretation, Computer-Assisted/*methods ; Radiography, Abdominal/*methods ; Signal-To-Noise Ratio ; Statistics, Nonparametric ; Tomography, X-Ray Computed/*methods

OBJECTIVE: To evaluate the therapeutic efficacy and safety of percutaneous ethanol injection (PEI) alone and combined with radiofrequency ablation (RFA) for hepatocellular carcinomas (HCCs) in high risk locations. MATERIALS AND METHODS: We performed PEI for HCCs in RFA-high risk locations, either alone or in combination with RFA. There were 20 HCCs (1.7 +/- 0.9 cm) in 20 patients (PEI group: n = 12; PEI + RFA group: n = 8). We evaluated technical success, local tumor progression and complications in both groups. RESULTS: Technical success was achieved in all HCCs in both groups. During follow-up, local tumor progression was found in 41.7% (5/12) in the PEI group, whereas 12.5% (1/8) for the PEI + RFA group (p = 0.32). Bile duct dilatation was the most common complication, especially when the tumors were in periportal locations; 55% (5/9) in the PEI group and 50% (2/4) in the PEI + RFA group (p = 1.00). One patient in the PEI group developed severe biliary stricture and upstream dilatation that resulted in atrophy of the left hepatic lobe. One patient treated with PEI + RFA developed cholangitis and an abscess. CONCLUSION: Combined PEI and RFA treatment has a tendency to be more effective than PEI alone for managing HCCs in high risk locations, although the difference is not statistically significant. Even though PEI is generally accepted as a safe procedure, it may cause major biliary complications for managing HCCs adjacent to the portal vein.
Aged ; Aged, 80 and over ; Carcinoma, Hepatocellular/*drug therapy/*surgery ; Catheter Ablation/*methods ; Chemoembolization, Therapeutic/*methods ; Disease Progression ; Ethanol/administration & dosage ; Female ; Humans ; Liver Neoplasms/*drug therapy/*surgery ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Postoperative Complications ; Retrospective Studies ; Statistics, Nonparametric ; Tomography, X-Ray Computed

OBJECTIVE: To determine in vivo efficacy of radiofrequency ablation (RFA) in porcine liver by using 15-gauge Octopus(R) (15-G Octopus(R)) electrodes to create a large coagulation. MATERIALS AND METHODS: A total of 18 coagulations were created by using a 180-W generator and 15-G Octopus(R) electrodes during laparotomy, performed in 14 pigs. Coagulation necrosis was created in the pig livers by the use of one of three RFA protocols: 1) group A, monopolar RFA using a 15-G Octopus(R) electrode with a 5-mm inter-electrode distance (n = 4); 2) group B, monopolar RFA using a 15-G Octopus(R) electrode with a 10-mm inter-electrode distance (n = 6); and 3) group C, switching monopolar RFA using two 15-G Octopus(R) electrodes (n = 8). The energy efficiency, shape, maximum and minimum diameters (Dmx and Dmi), and the volume of the coagulation volume were measured in each group. The Summary statistics were obtained and Mann-Whitney test was were performed. RESULTS: The mean ablated volume of each group was 49.23 cm3 in A, 64.11 cm3 in B, and 72.35 cm3 in C. The mean Dmx and Dmi values were 5.68 cm and 4.58 cm in A and 5.97 cm and 4.97 cm in B, respectively. In group C, the mean diameters of Dmx and Dmi were 6.80 cm and 5.11 cm, respectively. The mean ratios of Dmi/Dmx were 1.25, 1.20, and 1.35 in groups A, B, and C, respectively. There was one animal death during the RFA procedure, the cause of which could not be subsequently determined. However, there were no other significant, procedure-related complications during the seven-hour-delayed CT scans. CONCLUSION: RFA procedures using 15-G Octopus(R) electrodes are useful and safe for creating a large ablation in a single electrode model as well as in the multiple electrodes model.
Animals ; Catheter Ablation/*methods ; Electrocoagulation/*instrumentation ; *Electrodes ; Liver/radiography/*surgery ; Statistics, Nonparametric ; Swine ; Tomography, X-Ray Computed