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

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

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 identify CT and FDG-PET features associated with epidermal growth factor receptor (EGFR) protein overexpression, and to evaluate whether imaging features and EGFR-overexpression can help predict clinical outcome. MATERIALS AND METHODS: In 214 patients (M : F = 129 : 85; mean age, 63.2) who underwent curative resection of stage I non-small cell lung cancer, EGFR protein expression status was determined through immunohistochemical analysis. Imaging characteristics on CT and FDG-PET was assessed in relation to EGFR-overexpression. Imaging features and EGFR-overexpression were also evaluated for clinical outcome by using the Cox proportional hazards model. RESULTS: EGFR-overexpression was found in 51 patients (23.8%). It was significantly more frequent in tumors with an SUVmax > 5.0 (p < 0.0001), diameter > 2.43 cm (p < 0.0001), and with ground glass opacity < or = 50% (p = 0.0073). SUVmax > 5.0 (OR, 3.113; 95% CI, 1.375-7.049; p = 0.006) and diameter > 2.43 cm (OR, 2.799; 95% CI, 1.285-6.095; p = 0.010) were independent predictors of EGFR overexpression. Multivariate analysis showed that SUVmax > 4.0 (hazard ratio, 10.660; 95% CI, 1.370-82.966; p = 0.024), and the presence of cavitation within a tumor (hazard ratio, 3.122; 95% CI, 1.143-8.532; p = 0.026) were factors associated with poor prognosis. CONCLUSION: EGFR-overexpression is associated with high SUVmax, large tumor diameter, and small GGO proportion. CT and FDG-PET findings, which are closely related to EGFR overexpression, can be valuable in the prediction of clinical outcome.
Adult ; Aged ; Aged, 80 and over ; Carcinoma, Non-Small-Cell Lung/metabolism/mortality/*radiography/*radionuclide imaging ; Chi-Square Distribution ; Female ; Fluorodeoxyglucose F18/therapeutic use ; Humans ; Lung Neoplasms/metabolism/mortality/*radiography/*radionuclide imaging ; Male ; Middle Aged ; Neoplasm Staging ; Positron-Emission Tomography/*methods ; Proportional Hazards Models ; ROC Curve ; Radiopharmaceuticals/diagnostic use ; Receptor, Epidermal Growth Factor/*metabolism ; Statistics, Nonparametric ; Survival Rate ; Tomography, X-Ray Computed/*methods

OBJECTIVE: We aimed to evaluate the time efficiency and diagnostic accuracy of automated myocardial computed tomography perfusion (CTP) image analysis software. MATERIALS AND METHODS: 320-row CTP was performed in 30 patients, and analyses were conducted independently by three different blinded readers by the use of two recent software releases (version 4.6 and novel version 4.71GR001, Toshiba, Tokyo, Japan). Analysis times were compared, and automated epi- and endocardial contour detection was subjectively rated in five categories (excellent, good, fair, poor and very poor). As semi-quantitative perfusion parameters, myocardial attenuation and transmural perfusion ratio (TPR) were calculated for each myocardial segment and agreement was tested by using the intraclass correlation coefficient (ICC). Conventional coronary angiography served as reference standard. RESULTS: The analysis time was significantly reduced with the novel automated software version as compared with the former release (Reader 1: 43:08 +/- 11:39 min vs. 09:47 +/- 04:51 min, Reader 2: 42:07 +/- 06:44 min vs. 09:42 +/- 02:50 min and Reader 3: 21:38 +/- 3:44 min vs. 07:34 +/- 02:12 min; p < 0.001 for all). Epi- and endocardial contour detection for the novel software was rated to be significantly better (p < 0.001) than with the former software. ICCs demonstrated strong agreement (> or = 0.75) for myocardial attenuation in 93% and for TPR in 82%. Diagnostic accuracy for the two software versions was not significantly different (p = 0.169) as compared with conventional coronary angiography. CONCLUSION: The novel automated CTP analysis software offers enhanced time efficiency with an improvement by a factor of about four, while maintaining diagnostic accuracy.
Aged ; Analysis of Variance ; Body Mass Index ; Coronary Angiography ; Coronary Artery Disease/*radiography ; *Efficiency, Organizational ; Female ; Humans ; Male ; Middle Aged ; Myocardial Perfusion Imaging/*methods ; Pattern Recognition, Automated/*methods ; Prospective Studies ; Radiographic Image Interpretation, Computer-Assisted/*methods ; *Software ; Statistics, Nonparametric ; Time Factors ; Tomography, X-Ray Computed/*methods