Patient radiation risk reduction by controlling the tube start angle in single and dual source spiral CT scans: A simulation study.

BACKGROUND: Organ doses in spiral CT scans depend on the tube start angle. PURPOSE: To determine the effective dose in single source CT (SSCT) and dual source CT (DSCT) scans as a function of tube start angle and spiral pitch value to identify the dose reduction potential by selecting the optimal start angle. METHODS: Using Monte Carlo simulations, dose values for different tube positions with an angular increment of 10 ∘ $10^\circ$ and a longitudinal increment of 4.5 m m $4.5 \,\mathrm{m}\mathrm{m}$ were simulated over a range of 31.5 c m $31.5 \,\mathrm{c}\mathrm{m}$ with collimations of 40 mm $40\, \mathrm{mm}$ , 60 mm $60\, \mathrm{mm}$ , and 80 m m $80 \,\mathrm{m}\mathrm{m}$ . The simulations were performed for the thorax region of six adult patients based on clinical CT data. From the resulting dose distributions, organ doses and effective dose were determined as a function of tube angle and longitudinal position. Using these per-view dose data, the individual organ doses, as well as the total effective dose, were determined for spiral scans with and without tube current modulation (TCM) with pitch values ranging from 0.5 to 1.5 for SSCT and up to 3.0 for DSCT. The dose of the best and worst tube start angle in terms of dose was determined and compared to the mean dose over all tube start angles. RESULTS: With increasing pitch and collimation, the dose variations from the effective dose averaged over all start angles increase. While for a collimation of 40 m m $40 \,\mathrm{m}\mathrm{m}$ , the variations from the mean dose value stay below 5 % $5 \%$ for SSCT, we find that for a spiral scan with a pitch of 3.0 for DSCT with TCM and collimation of 80 m m $80 \,\mathrm{m}\mathrm{m}$ , the dose for the best starting angle is on average 16 % $16 \%$ lower than the mean value and 28 % $28 \%$ lower than the maximum value. CONCLUSIONS: Variation of the tube start angle in spiral scans exhibits substantial differences in radiation dose especially for high pitch values and for high collimations. Therefore, we suggest to control the tube start angle to minimize patient risk.

Clinical application of high-resolution spiral CT scanning in the diagnosis of auriculotemporal and ossicle.

Precision and intelligence in evaluating the complexities of middle ear structures are required to diagnose auriculotemporal and ossicle-related diseases within otolaryngology. Due to the complexity of the anatomical details and the varied etiologies of illnesses such as trauma, chronic otitis media, and congenital anomalies, traditional diagnostic procedures may not yield accurate diagnoses. This research intends to enhance the diagnosis of diseases of the auriculotemporal region and ossicles by combining High-Resolution Spiral Computed Tomography (HRSCT) scanning with Deep Learning Techniques (DLT). This study employs a deep learning method, Convolutional Neural Network-UNet (CNN-UNet), to extract sub-pixel information from medical photos. This method equips doctors and researchers with cutting-edge resources, leading to groundbreaking discoveries and better patient healthcare. The research effort is the interaction between the CNN-UNet model and high-resolution Computed Tomography (CT) scans, automating activities including ossicle segmentation, fracture detection, and disruption cause classification, accelerating the diagnostic process and increasing clinical decision-making. The suggested HRSCT-DLT model represents the integration of high-resolution spiral CT scans with the CNN-UNet model, which has been fine-tuned to address the nuances of auriculotemporal and ossicular diseases. This novel combination improves diagnostic efficiency and our overall understanding of these intricate diseases. The results of this study highlight the promise of combining high-resolution CT scanning with the CNN-UNet model in otolaryngology, paving the way for more accurate diagnosis and more individualized treatment plans for patients experiencing auriculotemporal and ossicle-related disruptions.

Machine Learning Model Based on Radiomics for Preoperative Differentiation of Jaw Cystic Lesions.

OBJECTIVE: This study aims to use machine learning techniques together with radiomics methods to build a preoperative predictive diagnostic model from spiral computed tomography (CT) images. The model is intended for the differential diagnosis of common jaw cystic lesions. STUDY DESIGN: Retrospective, case-control study. SETTING: This retrospective study was conducted at Sun Yat-sen Memorial Hospital of Sun Yat-sen University (Guangzhou, Guangdong, China). All the data used to build the predictive diagnostic model were collected from 160 patients, who were treated at the Department of Oral and Maxillofacial Surgery at Sun Yat-sen Memorial Hospital of Sun Yat-sen University between 2019 and 2023. METHODS: We included a total of 160 patients in this study. We extracted 107 radiomic features from each patient's CT scan images. After a feature selection process, we chose 15 of these radiomic features to construct the predictive diagnostic model. RESULTS: Among the preoperative predictive diagnostic models built using 3 different machine learning methods (support vector machine, random forest [RF], and multivariate logistic regression), the RF model showed the best predictive performance. It demonstrated a sensitivity of 0.923, a specificity of 0.643, an accuracy of 0.825, and an area under the receiver operating characteristic curve of 0.810. CONCLUSION: The preoperative predictive model, based on spiral CT radiomics and machine learning algorithms, shows promising differential diagnostic capabilities. For common jaw cystic lesions, this predictive model has potential clinical application value, providing a scientific reference for treatment decisions.

Prognosis of Methanol Poisoning in a Developing Setting.

BACKGROUND: Methanol-poisoning can be a challenging cause of mortality. Identifying the epidemiological, clinical, and para-clinical determinants of outcome in methanol-poisoning patients could be a step forward to its management. METHODS: In this hospital-based cohort study, 123 methanol-poisoning patients were included. Data on background variables, details of methanol consumption, and laboratory assessments were recorded for each patient. Patients underwent brain CT scans without contrast. We evaluated the association of all gathered clinical and para-clinical data with patients' outcome and length of hospital stay (LOS). Independent association of potential determinants of death, and LOS were modeled applying multivariable logistic, and Ordinary Least Square regressions, respectively. Odds ratio (OR), and regression coefficient (RC), and their 95% confidence intervals (CIs) were estimated. RESULTS: Most of the study population were male (n=107/123). The mean age of the participants was 30.3±9.1 years. Ninety patients (73.2%) were reported as being conscious on admission, and 34.3% of patients were identified with at least one abnormality in their CT scan. Level of consciousness (LOC) (OR: 42.2; 95% CI: 2.35-756.50), and blood pH (OR: 0.37; 95% CI: 0.22-0.65) were associated with death. Supratentorial edema (RC: 17.55; 95% CI: 16.95-18.16) were associated with LOS. CONCLUSION: Besides LOC, patients with any abnormality in their brain CT scan on admission were found to be at higher risk of death, and patients with supratentorial edema were at risk of longer LOS. Brain CT-scan on admission should be considered as a part of the routine procedure during the management of methanol-poisoning.

MSCTA imaging analysis of autologous arteriovenous fistula dysfunction in maintenance hemodialysis patients.

OBJECTIVE: To observe the multi-slice spiral CT angiography (MSCTA) imaging features of arteriovenous fistula dysfunction in patients undergoing maintenance hemodialysis and analyze the significance of the imaging examination. METHODS: Altogether 90 patients with end-stage renal disease treated by maintenance hemodialysis in General Hospital of China Resources & Wisco from June 2020 to February 2023 were divided into a normal function group (n=68) and a dysfunction group (n=22) according to the function of autogenous arteriovenous fistula. The clinical data of the two groups were recorded. The MSCTA was performed in each patient, and the manifestations of arteriovenous fistula dysfunction were analyzed. Additionally, the vascular access stenosis, vascular access lumen stenosis, arteriovenous diameter, blood flow, and hemodynamic indices were tested, and the value of MSCTA in predicting arteriovenous fistula function was analyzed by Logistic regression. RESULTS: The degree of vascular access stenosis and vascular access lumen stenosis in the normal group were less than those in the dysfunctional group (P<0.05). The arteriovenous diameter, blood flow, blood flow velocity at anastomotic vein end, dialysis adequacy (spKt/V), and von Willebrand factor (vWF) function in the normal group were larger than those in the dysfunction group, and the radial artery shear force was lower than in the dysfunction group, with statistical significance (P<0.05). Among the arteriovenous fistula dysfunction, there were 3 patients with anastomotic + outflow vein stenosis, 4 patients with outflow vein stenosis, 9 patients with inflow artery + anastomosis + outflow vein stenosis, and 6 patients with superior vena cava stenosis. Logistic regression analysis showed that slow blood flow velocity at the venous end of anastomosis and high shear force of radial artery were influencing factors of arteriovenous fistula dysfunction, and the area under ROC curve of blood flow velocity at the venous end of anastomosis plus shear force of radial artery was 0.93, with a sensitivity of 0.87 and a specificity of 0.85. CONCLUSION: MSCTA can be used to evaluate the dysfunction of autologous arteriovenous fistula in patients undergoing maintenance hemodialysis, and provide important reference information for the formulation of the next best clinical treatment plan.

[Diagnostic value of 3D fast spin-echo sequence scanning combined with multislice spiral CT in knee cruciate ligament injury].

OBJECTIVE: To explore the potential value of three-dimensional fast spin echo（3D-SPACE） combined with multilayer spiral CT （MSCT） in the diagnosis of knee cruciate ligament injury, to provide a new direction for the optimization of subsequent clinical diagnosis. METHODS: A total of 120 patients with knee cruciate ligament injury were treated from April 2020 to April 2021, aged from 21 to 68 with an average of（41.52±4.13） years old. For all patients, separate MSCT scanner scans, 3D-SPACE sequence scans alone and 3D-SPACE sequence combined with MSCT scans were used. The injury and classification of the anterior and posterior cruciate ligament of the knee were compared, the length of the anterior-medial bundle and posterolateral bundle and its angle of the knee with the horizontal plane were observed, the diagnostic value of 3 diagnostic methods in knee cruciate ligament injury were determined. RESULTS: There was no significant difference between the 3D-SPACE sequence scan alone and the MSCT test alone on the total diagnostic rate and grading total diagnostic rate（P>0.05）. The total diagnostic rate and grading total diagnostic rate of 3D-SPACE scan combined with MSCT were significantly higher than those of 3D-SPACE scan or MSCT alone（P<0.05）. The 3D-SPACE sequence scan alone and the MSCT detection alone had no significant difference in the measurement values related to the anterior and posterior cruciate ligaments of the knee joint（P>0.05）. 3D-SPACE sequence scanning combined with MSCT detection on the knee joint anterior and posterior cruciate ligament related measurements were significantly higher than the 3D-SPACE sequence scan or MSCT detection alone（P<0.05）. The area under the ROC curve estimated by 3D-SPACE sequence scanning combined with MSCT was 0.960, which was significantly higher than that of 3D-SPACE sequence scanning and MSCT alone evaluating the area under the ROC curve line of 0.756 and 0.795. The combined 3D-SPACE sequence scanning and 3D-SPACE sequence scanning MSCT analysis and prediction models were statistically different（Z=2.236, P<0.05）, and MSCT alone and 3D-SPACE sequence scanning combined with MSCT analysis and prediction models were statistically different（Z=2.653, P<0.05）. CONCLUSION: The application of 3D-SPACE sequence combined with MSCT scanning for knee cruciate ligament injury can improve the diagnosis rate of patients with knee cruciate ligament injury.It can be used as a diagnostic tool for patients with knee cruciate ligament injury and is worthy of clinical application.

Diagnostic value of multi-slice spiral computed tomography angiography for intracranial aneurysm.

OBJECTIVE: To investigate the clinical value of multi-slice spiral computed tomography angiography (MSCTA) in the diagnosis of intracranial aneurysms (ICA). METHODS: The imaging data of 68 patients suspected of having ICA who were examined in the Department of Radiology of the First Affiliated Hospital of Nanjing Medical University from March 2018 to March 2021 were retrospectively analyzed. MSCTA and digital subtraction angiography (DSA) were performed on each patient, and the MSCTA imaging analysis was compared with DSA. RESULTS: The accuracy of DSA in the diagnosis of ICA was 98.53% (67/68), while the accuracy of MSCTA in the diagnosis of ICA was 97.06% (66/68), with no significant difference in diagnostic accuracy (P > 0.05). There were no significant differences in the diameter of the aneurysm, the width of the aneurysm neck, or the location of the aneurysm in the comparison of the ICA image between DSA and MSCTA (P > 0.05). CONCLUSION: MSCTA offers high accuracy and has favorable clinical value in the diagnosis of ICA. It is worth popularizing as the recommended examination method in clinical practice.

The role of computed tomography angiography in assessing the correlation between properties of coronary atherosclerotic plaque and blood lipids.

BACKGROUND: Coronary atherosclerotic heart disease (CAHD) is the leading cause of death in developed countries. OBJECTIVE: This study aimed to explore the correlation between the properties of coronary atherosclerotic plaque and blood lipids using computed tomography angiography (CTA). METHODS: A total of 83 patients with coronary heart disease were included in this study (males: 50; females: 33; average age: [59 ± 8] years old). They were classified into the stable angina group and unstable angina group. Atherosclerotic plaques were classified as fatty plaques (soft plaques), fibrous plaques, and calcified plaques based on the computed tomography (CT) values. SPSS 17.0 statistical software was used to analyze the correlation between the properties of angina and the CT values of atherosclerotic plaques, blood lipids, and plaque properties, and then compared between the stable and unstable angina groups. RESULTS: There were statistically significant differences in plaque properties between the stable and unstable angina groups (P< 0.001). During CTA examination, we found statistically significant differences in the CT density values of atherosclerotic plaques between the stable and unstable angina groups (P< 0.001). There were statistically significant differences between the properties of angina and the level of blood lipids (P< 0.05). CONCLUSION: Anginal properties negatively correlated with calcified plaques and positively correlated with non-calcified plaques. Calcified plaques negatively correlated with total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG), and positively correlated with high-density lipoprotein cholesterol (HDL-C). Non-calcified plaques negatively correlated with HDL-C and positively correlated with TC, LDL-C, and TG.

LDCT screening results among eligible and ineligible screening candidates in preventive health check-ups population: a real world study in West China.

To compare the LDCT screening results between eligible and ineligible screening candidates in preventive health check-ups population. Using a real-world LDCT screening results among people who took yearly health check-up in health management center of West China Hospital between 2006 and 2017. Objects were classified according to the China National Lung Cancer Screening Guideline with Low-dose Computed Tomography (2018 version) eligibility criteria. Descriptive analysis were performed between eligible and ineligible screening candidates. The proportion of ineligible screening candidates was 64.13% (10,259), and among them there were 4005 (39.04%) subjects with positive screenings, 80 cases had a surgical lung biopsy. Pathology results from lung biopsy revealed 154 cancers (true-positive) and 26 benign results (false-positive), the surgical false-positive biopsy rate was 4.17%, and ineligible group (7.69%) was higher than eligible group (2.47%), P < 0.05. Further, in ineligible screening candidates, the proportion of current smokers was higher among males compared to females (53.85% vs. 4.88%, P < 0.05). Of the 69 lung cancer patients detected in ineligible screening candidates, lung adenocarcinoma accounts for a high proportion of lung cancers both in male (75.00%) and female (85.00%). The proportion of ineligible screening candidates and the surgical false-positive biopsy rate in ineligible candidates were both high in health check-ups population.

Analysis of screening outcomes and factors influencing compliance among community-based lung cancer high-risk population in Nanchang, China, 2018-2020.

Objective: To investigate the screening results and compliance of low-dose computed tomography (LDCT) screening among the high-risk lung cancer populations in Jiangxi Province from 2018 to 2020, and to explore the related influencing factors of compliance. Methods: From November 2018 to October 2020, permanent residents in Nanchang City were selected and their demographic data and lung cancer risk factor data were collected to screen high-risk groups, and LDCT screening was performed on high-risk groups with diagnostic reports by 2 chief physicians. Descriptive analysis method was used to analyze the basic information of screening, screening results and screening compliance. χ2 and logistic regression test were used to conduct single and multi-factor analysis of screening compliance. Results: A total of 26,588 people participated in this screening, of which 34.4% (n=9,139) were at high risk of lung cancer, 3,773 participants were completed LDCT screening, and the screening compliance rate was 41.3%. Screening results showed that 389 participants were positive for suspected pulmonary tumor or lung nodules, the screening positive rate of 10.3%. The logistic multivariable results of screening compliance showed that the compliance was better in males, those who quit smoking, those with chronic respiratory diseases and family history of cancer, and those who have primary education, those with a history of occupational harmful exposure had a poor compliance. Conclusion: Compliance with lung cancer screening in Jiangxi Province, China still needs to be improved, and gender, education level, harmful occupational exposure, smoking, chronic respiratory diseases, and family history of tumors cancer play an important role on screening compliance.

Reducing windmill artifacts in clinical spiral CT using a deep learning-based projection raw data upsampling: Method and robustness evaluation.

BACKGROUND: Multislice spiral computed tomography (MSCT) requires an interpolation between adjacent detector rows during backprojection. Not satisfying the Nyquist sampling condition along the z-axis results in aliasing effects, also known as windmill artifacts. These image distortions are characterized by bright streaks diverging from high contrast structures. PURPOSE: The z-flying focal spot (zFFS) is a well-established hardware-based solution that aims to double the sampling rate in longitudinal direction and therefore reduce aliasing artifacts. However, given the technical complexity of the zFFS, this work proposes a deep learning-based approach as an alternative solution. METHODS: We propose a supervised learning approach to perform a mapping between input projections and the corresponding rows required for double sampling in the z-direction. We present a comprehensive evaluation using both a clinical dataset obtained using raw data from 40 real patient scans acquired with zFFS and a synthetic dataset consisting of 100 simulated spiral scans using a phantom specifically designed for our problem. For the clinical dataset, we utilized 32 scans as training set and 8 scans as validation set, whereas for the synthetic dataset, we used 80 scans for training and 20 scans for validation purposes. Both qualitative and quantitative assessments are conducted on a test set consisting of nine real patient scans and six phantom measurements to validate the performance of our approach. A simulation study was performed to investigate the robustness against different scan configurations in terms of detector collimation and pitch value. RESULTS: In the quantitative comparison based on clinical patient scans from the test set, all network configurations show an improvement in the root mean square error (RMSE) of approximately 20% compared to neglecting the doubled longitudinal sampling by the zFFS. The results of the qualitative analysis indicate that both clinical and synthetic training data can reduce windmill artifacts through the application of a correspondingly trained network. Together with the qualitative results from the test set phantom measurements it is emphasized that a training of our method with synthetic data resulted in superior performance in windmill artifact reduction. CONCLUSIONS: Deep learning-based raw data interpolation has the potential to enhance the sampling in z-direction and thus minimize aliasing effects, as it is the case with the zFFS. Especially a training with synthetic data showed promising results. While it may not outperform zFFS, our method represents a beneficial solution for CT scanners lacking the necessary hardware components for zFFS.

Essential thrombocythemia associated with fibrosis involving bilateral renal sinuses: A case report.

Essential thrombocythemia (ET) is associated with an increased risk of thrombosis and autoimmune renal involvement. We report an extremely rare case of an acute kidney injury (AKI) in the presence of bilateral renal pelvises fibrosis in a patient with a proven diagnosis of ET. A 48-year-old male patient with a past medical history of mild chronic kidney disease and ET was admitted to our hospital with AKI. The patient discontinued his hydroxyurea treatment for the past 2 months and laboratory data showed increasing serum creatinine levels and platelet counts with increased renal sizes, severe hydrocalyx, and bilateral renal sinuses' fibrosis in imaging. The patient started again on hydroxyurea therapy and showed improvement in all laboratory scales. ET and increased levels of platelet-derived growth factors could cause renal sinuses fibrosis and glomerulopathy. In ET patients with renal sinuses' fibrosis and glomerulopathy, initiating cytoreductive therapy could improve the outcome.

Unveiling a rare case: Cardiac rupture secondary to acute occlusion of the distal left circumflex artery detected by contrast-enhanced spiral CT.

A 79-year-old female patient was admitted to the hospital due to intense chest pain. Emergency percutaneous coronary intervention (PCI) revealed an occlusion in the distal portion of the left circumflex artery (LCx). The patient suffered from cardiac rupture, an uncommon yet extremely perilous condition, within 30 minutes following the procedure. This was verified through a computed tomography angiography (CTA) scan and bedside echocardiography. The etiology of cardiac rupture remains elusive, yet potential factors such as the patient's age, gender, initial acute myocardial infarction (AMI), and single-vessel disease without collateral circulation may be linked to this occurrence. This case report emphasizes that occluded tiny distal coronary arteries can also induce cardiac rupture and that a sufficient level of suspicion for the diagnosis of cardiac rupture should be raised when adequate fluid resuscitation fails to alleviate hypotension. Additionally, contrast-enhanced spiral computed tomography (CESCT) is highly effective in revealing certain pathological features associated with cardiac rupture.

Imaging findings of hepatocellular carcinoma with portal vein tumor thrombosis secondary to hepatic portal vein collateral circulation: a cross-sectional study.

Background: Hepatic portal vein collateral circulation plays an important role in maintaining the perfusion of hepatic portal vein. However, at present, there is little research on collateral circulation of hepatic portal vein. Our study aims to analysis the imaging types and clinical value of hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) invading and completely blocking different branches of portal vein, secondary to hepatic portal vein collateral circulation. Methods: This study retrospectively analyzed Hepatocellular carcinoma (HCC) with PVTT diagnosed with enhanced CT examination of the upper abdomen in our hospital from May 2020 to October 2021.The inclusion criteria for patients were the following: (I) ultimately diagnosed with HCC, (II) accompanied by complete obstruction of the main portal vein or left/right branches, and (III) with collateral circulation of the hepatic portal vein established. All images were postprocessed by multiplanar reconstruction (MPR), maximum intensity projection (MIP), and other reconstruction techniques to obtain images of the abnormal portal vein system and the collateral vessels running toward the hepatic portal veins. Three physicians jointly judged the imaging anatomical classification of each collateral vessel. The qualitative variables were compared by chi-squared test. Results: A total of 125 hepatic portal vein collateral vessels were observed in MPR and MIP reconstruction images of 71 patients with portal vein cancer thrombosis with established hepatic portal vein collateral circulation. Common hepatic collateral branches in patients with PVTT mainly include the biliary collateral branch, gastric collateral branch, mesenteric collateral branch, accessory portal vein system and the splenic branch. The incidence rate was respectively 77.5%, 36.6%, 32.4%, 28.2%, 1.41%. Conclusions: The correct understanding of the imaging anatomical classification of the collateral vessels of the hepatic portal vein can provide clinicians with more information for diagnosis and treatment planning.

Clinical Diagnosis and Value Analysis of Multilayer Spiral CT scan in early Pancreatic Cancer in retired athletic patients

An intriguing result of esophageal malignant growth resection is pancreatic disease. This study aimed to explore the demonstrative worth of multi-facet twisting processed tomography (MSCT) in malignant pancreatic growth to work on clinical comprehension, assess a fruitful, helpful, and painless indicative methodology, and make the basis for treatment. Pancreatic disease (PC) is the deadliest harm on the planet, with a five-year endurance pace of just 5%. Although absolute careful resection is the main corrective treatment for pancreatic disease, just around 20% of recently analyzed athletic patients get their pancreas eliminated. Retired athletic patients with harmful pancreatic development at this point have advanced sickness when they are dissected, inferable from the shortfall of early aftereffects and the inclination of pancreatic adenocarcinoma to go after connecting structures or metastasize at a starting stage. In this way, there is a high demise rate. Early recognizable proof of PC is urgent for further developing retired athletic patient endurance rates. PC is breaking down using handled tomography (CT) as well as alluring resonation imaging (MRI) with appealing resonation cholangiopancreatography (MRCP), or endoscopic ultrasound for biopsy or fine-needle want (EUS). In spite of the fact that multi-identifier line registered tomography assumes a significant part in the determination of PC, MRI with MRCP takes into consideration a more thorough examination of the morphological adjustments in the pancreas parenchyma and pancreatic channel, taking into account prior recognition of malignancies. In specific situations where CT and EUS are not absolutely demonstrative, positron discharge tomography procedures could assist with the finding. (AU)

Application effect of low-dose spiral CT on pulmonary nodules and its diagnostic value for benign and malignant nodules.

OBJECTIVE: This study was designed to determine the application effect of low-dose computed tomography (LDCT) on detecting pulmonary nodules (PNs) and its diagnostic value for benign and malignant pulmonary nodules. METHODS: Data of 432 patients with PNs admitted to Julu County Hospital between March 2018 and June 2021 in were collected and analysed retrospectively. All patients underwent LDCT and conventional-dose spiral computed tomography (CT). The detection rate and image characteristics of the two methods were compared, and the image quality and radiation dose of the two diagnostic methods were also compared. RESULTS: No significant difference was found between LDCT and conventional-dose spiral CT in the detection rate of lung cancer (P>0.05). The area under the curve of conventional-dose CT was 0.932, with a specificity and sensitivity of 93.87% and 92.45%, and the area under the curve of LDCT was 0.902, with a specificity and sensitivity of 90.80% and 89.62%. The radiation dose consumed during LDCT was greatly less than that consumed by conventional-dose CT (P<0.05). Additionally, the two methods were not different in CT image quality and superior vena cava artifact (P>0.05). No notable difference was found between LDCT and conventional-dose CT in terms of the diagnosis rate of PNs in vascular aggregation sign, pleural indentation sign, lobulation sign and spiculation sign. CONCLUSION: LDCT can clearly show the typical images of early lung cancer, with less effective radiation dose, and can thus contribute to a high detection rate, so it is worth popularizing.

A comparative study of three-dimensional airway changes after fibula flap reconstruction for benign and malignant tumours in the anterior mandible.

Surgical treatment of tumours in the anterior mandible and surrounding tissues may result in defects which can be restored by a fibula free flap. The upper airway may change during this process. The purpose of this retrospective study was to evaluate upper airway changes after fibula free flap reconstruction. A total of 37 patients who underwent anterior mandibulectomy and fibula free flap reconstruction between 2012 and 2020 were recruited. Patients with benign and malignant tumours involving the anterior mandible were included. Spiral computed tomography was performed 1 week preoperatively, 1 week postoperatively, and at> 1 year (range 12-23 months) after surgery. Cross-sectional areas and volumes of the upper airway were measured. Data were analysed by two-way analysis of variance. The upper airway in the malignant tumour group showed an increasing trend, especially at the soft palate and tongue base levels (P < 0.01). In the benign tumour group, the upper airway showed no significant changes. The location of the minimum cross-sectional area moved downwards in both groups, and the area increased in the malignant tumour group during long-term follow-up. Upper airway obstruction is less likely to occur in the long term after surgical resection of anterior mandible malignancies and fibula free flap reconstruction.

Echocardiographic evaluation of supracardiac anomalous pulmonary venous connection in children: comparison with multilayer spiral CT.

Objective To explore the clinical value of transthoracic echocardiography (TTE) in the differentiation of Supracardiac Anomalous Pulmonary Venous Connection (SAPVC) in children. Materials and methods A total of 118 children with concurrent TTE and CT databases of cases diagnosed with SAPVCs were included. We analyzed the consistency between the two for the ability to diagnose the classification of SAPVC, drainage sites, ectopic pulmonary veins and the segments of superior vena cava (SVC). Results The consistency between TTE and CT in diagnosing the existence of SAPVC and the classification were 88.1% (95% CI: 80.9-93.4%) and 91.0% (95% CI: 84.1-95.6%), respectively. The error rate of partial type diagnosed by TTE was significantly higher than that of total and mixed type (20.5% vs. 2.8%, P = 0.003). The consistency between TTE and CT to determine drainage sites was 91.9% (95% CI: 85.2-96.2%). TTE had a significantly higher error rate in determining pulmonary vein drainage to the SVC than in those draining into the left innominate vein (17.5 vs. 2.5%, P = 0.007). The consistency of TTE and CT in judging the number of veins was 87.4% (95% CI: 79.7-92.9%). The error rate in determining the presence of 2 and 5 ectopic pulmonary veins was significantly higher than those of 1 and 4 veins (P < 0.05). Conclusion TTE for diagnosing partial SAPVC and identifying the drainage site of SVC has a high error rate of misdiagnosis and missed diagnosis. The extra attention should be given to these factors in clinical practice to improve the accuracy of TTE in diagnosing SAPVC.

Application progress of imaging examination in the diagnosis of urethral stricture / 现代泌尿外科杂志

Urethra stricture is one of the most common diseases of the urinary system. Accurate imaging diagnosis is key to the selection of surgical approach. At present, X-ray urethral imaging can show the form of urethra cavity, but not the tissues around the urethra. Sonourethrography (SUG) can dynamically identify the urethral cavity and the surrounding tissues without radiation exposure. Multi-layer spiral CT urethrography (CTU) has advantages of no need to adjust the position, quick scanning and reconstruction of the three-dimensional image, which can accurately show the location, length and degree of urethral stricture, and the spatial relationship with the surrounding tissues. Magnetic resonance urethrography (MRU) can provide useful information of the urethral stricture and soft tissues around the urethra, especially in urethral strictures caused by pelvic fractures and complex urethral stenosis. The choice of imaging method should be based on the etiology, anatomy, types of urethral injury and the general situation of patients. Appropriate imaging method can improve the diagnostic accuracy.