Analysis of The Value of Multi-Slice Spiral CT and Magnetic Resonance Imaging in The Diagnosis of Carpal Joint Injury

Objective:To analyze the value of multi-slice spiral computed tomography(CT)and magnetic resonance imaging(MRI)in the diagnosis of carpal joint injury.Methods:A total of 130 patients with suspected wrist injuries admitted to the Department of Orthopedics of our hospital from January 2023 to January 2024 were selected and randomly divided into a single group(n=65)and a joint group(n=65).The single group was diagnosed using multi-slice spiral CT,and the joint group was diagnosed using multi-slice spiral CT and magnetic resonance imaging,with pathological diagnosis as the gold standard.The diagnostic results of both groups were compared to the gold standard,and the diagnostic energy efficiency of both groups was compared.Results:The diagnostic results of the single group compared with the gold standard were significant(P<0.05).The diagnostic results of the joint group compared with the gold standard were not significant(P>0.05).The sensitivity and accuracy of diagnosis in the joint group were significantly higher than that in the single group(P<0.05).The specificity of diagnosis in the joint group was higher as compared to that in the single group(P>0.05).Conclusion:The combination of multi-slice spiral CT and MRI was highly accurate in diagnosing wrist injuries,and the misdiagnosis rate and leakage rate were relatively low.Hence,this diagnostic program is recommended to be popularized.

Efficacy of multi-slice spiral computed tomography in evaluating gastric cancer recurrence after endoscopic submucosal dissection

BACKGROUND Recurrence is the major challenge facing endoscopic submucosal dissection(ESD)-based treatment therapies for early gastric cancer(EGC).Urgent development of simple and easy surveillance approaches will enhance clinical treatment of the disease.AIM To explore the role of computed tomography(CT)recurrence in evaluating EGC after ESD treatment.METHODS We retrospectively recruited patients from our endoscopy department,between January 2002 and December 2015,and analyzed their basic characteristics,including symptoms,CT results,and results of endoscopy with biopsy,among others.RESULTS Among a total of 2150 patients EGC patients surveyed,1362 met our inclusion and exclusion criteria and were therefore enrolled in our study.The cohort’s sensitivity of CT for recurrent GC and specificity were 44.22%and 43.86%,respectively,with negative and positive predictive values of 40.15%(275/685)and 48.01%(325/677),respectively.The area under the curve of arterial and venous CT values for recurrent EGC were 0.545,and 0.604,respectively.Receiver operating characteristic curve revealed no statistically significant differences between arterial and venous CT values for recurrent EGC.CONCLUSION Enhanced CT has superior diagnostic efficacy,but less accuracy,compared to gold standard techniques in patients with recurrent EGC.

Multi-slice spiral CT angiography in evaluating donors of living-related liver transplantation

BACKGROUND: During the past years, the number of liver transplantation has increased greatly, but the number of available organs has not increased. In view of the critical shortage of organs, the indications for living-related liver transplantation (LRLT) have broadened since experience with the procedure has been achieved. This study was undertaken to assess the value of multi-slice spiral CT (MSCT) angiography in evaluating the hepatic arterial and veinous anatomy of potential donors for LRLT. METHODS: MSCT was performed after intravenous injection of contrast material at 3 ml/s. The total dose was calculated as 2 ml/kg. Twenty LRLT donors (2 men and 18 women) were subjected to MSCT angiography of hepatic blood vessels. These were generated by volume rendering and maximum intensity projection, while curved planar reformation was added in 5 patients. RESULTS: We identified 10 important hepatic vascular variants in 9 of the 20 donors (4 arterial, 4 venous, and 2 portal venous variants). In hepatic arterial variants, two had a replaced right hepatic artery arising from the superior mesenteric artery, an accessory right hepatic artery from the superior mesenteric artery and a replaced left hepatic artery arising from the left gastric artery. In hepatic venous variants, three had an accessory inferior right hepatic vein and one had two accessory inferior right hepatic veins. In hepatic portal venous variants, two had trifurcation of the main portal vein. CONCLUSIONS: As a non-invasive and reliable method, MSCT angiography is of value in the clinical evaluation of LRLT donors. MSCT angiography should be recommended as a routine preoperative examination for potential LRLT donors.

Multi-slice spiral computed tomography in differential diagnosis of gastric stromal tumors and benign gastric polyps,and gastric stromal tumor risk stratification assessment

BACKGROUND The biological characteristics of gastric stromal tumors are complex,and their incidence has increased in recent years.Gastric stromal tumors(GST)have potential malignant tendencies,and the probability of transformation into malignant tumors is as high as 20%-30%.AIM To investigate the value of multi-slice spiral computed tomography(MSCT)in the differential diagnosis of GST and benign gastric polyps,and GST risk stratification assessment.METHODS We included 64 patients with GST(GST group)and 60 with benign gastric polyps(control group),confirmed by pathological examination after surgery in PLA General Hospital,from January 2016 to June 2021.The differences in the MSCT imaging characteristic parameters and enhanced CT values between the two groups before surgery were compared.According to the National Institutes of Health’s standard,GST is divided into low-and high-risk groups for MSCT imaging characteristic parameters and enhanced CT values.RESULTS The incidences of extraluminal growth,blurred boundaries,and ulceration in the GST group were significantly higher than those in the control group(P<0.05).The CT values and enhanced peak CT values in the arterial phase in the CST group were higher than those in the control group(P<0.05).The MSCT differential diagnosis of GST and gastric polyp sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,and areas under the curve(AUCs)were 73.44%,83.33%,26.56%,16.67%,0.784,respectively.The receiver operating characteristic curves were plotted with the arterial CT value and enhanced peak CT value,with a statistical difference.The results showed that the sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,and AUC value of arterial CT in the differential diagnosis of GST and gastric polyps were 80.18%,62.20%,19.82%,37.80%,and 0.710,respectively.The sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,and AUC value of the enhanced peak CT value in the differential diagnosis of GST and gastric polyps were 67.63%,60.40%,32.37%,39.60%,and 0.710,respectively.The incidence of blurred lesion boundaries and ulceration in the high-risk group was significantly higher than that in the low-risk group(P<0.05).The arterial phase and enhanced peak CT values in the high-risk group were significantly higher than those in the low-risk group(P<0.05).CONCLUSION Presurgical MSCT examination has important value in the differential diagnosis of GST and gastric benign polyps and can effectively evaluate the risk grade of GST patients.

Multi-slice spiral computed tomography in diagnosing unstable pelvic fractures in elderly and effect of less invasive stabilization

BACKGROUND Older people are more likely to experience pelvic fractures than younger people.Multi-slice spiral computed tomography(CT)uses three-dimensional(3D)reconstruction technology to generate 3D images that can clearly demonstrate the 3D space of fractures and detect fractures at a higher rate.AIM To investigate the clinical value of multi-slice spiral CT 3D reconstruction in the diagnosis of unstable pelvic fractures in the elderly as well as the effect of less invasive stabilization.METHODS A total of 86 patients with unstable pelvic fractures treated between March 2016 and March 2019 underwent femoral supracondylar bone traction before surgery.Pelvic radiography and multi-row spiral CT were performed successively once the patient’s vital signs and hemodynamic indices were stable.Secondary processing of the original data was performed to obtain 3D reconstruction images and determine the vertical displacement of the pelvis.After basic or complete reduction,minimally invasive internal fixation using hollow lag screws was performed.The detection rates of fracture location and classification by X-ray and CT reconstruction were compared.Patients were divided into two groups according to the presence or absence of preoperative 3D reconstruction to compare postoperative reduction,wound healing time,fracture healing time,hospitalization time,visual analog scale(VAS)score,poor internal fixation,and functional recovery.RESULTS The diagnostic coincidence rates of X-rays for pubic symphysis,ilium wing,sacroiliac periarticular,and sacral fractures were lower than those of CT reconstruction.The coincidence rate of CT reconstruction in the clinical classification of pelvic fractures was 100%,whereas 11 cases were misdiagnosed by X-ray;the total coincidence rate was 87.21%.The total excellent and good rates of postoperative reduction were significantly higher in the study group than in the control group(P<0.05).The wound healing,fracture healing,and hospitalization times were significantly shorter in the study group than in the control group(P<0.05).The VAS scores decreased in both groups postoperatively and were lower in the study group than in the control group(P<0.05).The total incidence of poor postoperative internal fixation was significantly lower in the study group than in the control group(P<0.05).The overall rate of postoperative functional recovery was significantly higher in the study group than in the control group(P<0.05).CONCLUSION Multi-slice spiral CT has high guiding significance for the diagnosis,classification,and treatment of unstable pelvic fractures in the elderly.Preoperative 3D reconstruction can effectively shorten the operation time and promote fracture healing,while minimally invasive internal fixation can effectively reduce pain and promote functional recovery of fracture sites,making it worthy of clinical application.

Comparison of the Imaging Manifestations and Diagnostic Values of Multi-slice Spiral CT and Enhanced MRI Scans of Primary Liver Cancer(PLC)Intrahepatic Lesions

Objective:To compare and analyze the clinical diagnostic value of multi-slice spiral CT and enhanced MRI for primary liver cancer(PLC),and to summarize the imaging findings.Methods:The research subjects in this article were 50 patients with PLC who were admitted to our hospital from 2017 April to 2018 September.After the patients were admitted,they were examined by multi-slice spiral CT and enhanced MRI scanning,and the pathological diagnosis results were followed up.Relevant information was reviewed and analyzed.Results:The detection rate of multi-slice spiral CT was higher than that of MRI in the portal venous phase lesion detection.The difference was statistically significant(P<0.05).The detection rate of lesions in the arterial phase and delayed phase was not statistically significant(P>0.05);the diagnostic accuracy of multi-slice spiral CT was 85.96%,and the diagnostic accuracy of enhanced MRI scanning was 91.11%,which was not statistically significant(P>0.05).MRI scans showed the capsules of primary liver cancer better than CT,but the difference was not statistically significant(P>0.05).Conclusion:In conclusion,both multi-slice spiral CT and enhanced MRI can be used for the effective diagnosis of primary liver cancer intrahepatic lesions.The diagnostic value of the two is equivalent,but enhanced MRI has a slightly higher diagnostic accuracy and can be used as the preferred method.

Segmental radiofrequency ablation of pulmonary vein ostia for patients with refractory paroxysmal atrial fibrillation using multi-slice spiral computed tomography guidance

Objective: To evaluate the safety and clinical efficacy of segmental radiofrequency ablation of pulmonary vein (PV)ostia for patients with refractory paroxysmal atrial fibrillation (AF) under multi-slice spiral computed tomography (MSCT)guidance before the procedure. Methods: A series of 58 consecutive patients with refractory paroxysmal AF were enrolled to undergo segmental radiofrequency ablation ofPV ostia. The 36 male and 22 female patients with mean age of (57.4±9.5) (32～79)atrium (LA) and proximal PVs. Patients then underwent segmental radiofrequency ablation of PV ostia using PV circular mapping catheter manipulated several times to ensure complete isolation between PVs and LA. Results: No complications occurred during the procedure. One patient developed delayed cardiac tamponade, which was drained percutaneously. The mean follow-up time was (17.1±9.3) months. Forty-one patients (95%) experienced improved quality of life one month after the procedure. Thirty-six patients (83%) showed stable sinus rhythm, while 10 patients (23%) required additional anti-arrhythmic drugs. AF returned≥1time in 6 (14%) patients who underwent anti-arrhythmic drug therapy, but the number of episodes was less than that before the procedure. However, one patient experienced recurrent episodes of atrial flutter. Conclusion: It is safe and effective to perform segmental radiofrequency ablation of PV ostia for patients with refractory paroxysmal AF using MSCT guidance mappening.

Bezoar-induced small bowel obstruction: Clinical characteristics and diagnostic value of multi-slice spiral computed tomography

AIM: To determine the possible predisposing factors of bezoar-induced small bowel obstruction(b I-Sb O) and to discuss the diagnostic value of multi-slice spiral computed tomography,particularly contrast-enhanced scanning,in this condition.METHODS: A total of 35 b I-Sb O cases treated at our hospital from January 2007 to December 2013 were retrospectively analysed.Complete clinical and computed tomography(CT) data of the patients were available and confirmed by surgery.SbO was clinically diagnosed on the basis of clinical manifestations.Of the 35 patients,18 underwent abdominal and pelvic CT planar scanning with GE 64-slice spiral CT and 17 underwent abdominal and pelvic CT planar scanning with GE 64-slice spiral CT combined with contrastenhanced examination.Original images were processed using a GE ADW4.3 workstation to obtain MPR,CPR,MIP and CTA images.The images of all patients were evaluated by two abdominal imaging experts.The main analytical contents of planar scanning included intestinal bezoar conditions,changes in the intestinal wall and changes in peri-intestinal conditions.Vascular hyperaemia and arterial blood supply conditions at a specific obstruction site and the distal end of the obstruction site were evaluated through contrastenhanced examination.RESULTS: The proportion of males to females among the 35 cases was 1:1.69(13:22); median age was 63.3 years.The following cases were observed: 29(82.8%) cases occurred in autumn and winter and showed a history of consuming high amounts of persimmon and hawthorn; 19(54.3%) cases revealed a history of gastrointestinal surgery; 19 exhibited incomplete dentition,with missing partial or whole posterior teeth; 26 suffered from obstruction at the ileum.A total of 51 bezoars were found in these patients,of whom 16(45.7%) had multiple bezoars.CT planar scanning of bezoars showed lumps with mottled gas inside the intestinal cavity.Furthermore,9 cases of bezoars had envelopes and 11 cases were accompanied with thickening of the distal wall of the obstructed bowel.Scanning of 17 cases was enhanced; the results revealed that the mesenteric blood vessels at the obstruction site and the proximal site were dilated,and a total of 7 cases were accompanied with distal vascular dilation and intestinal wall thickening.CONCLUSION: b I-Sb O exhibits regional and seasonal characteristics.CT planar and contrast-enhanced scanning can be applied to diagnose and observe vascular conditions in obstructed zones.

Study on the combined value of multi-slice spiral CT in the diagnosis of elderly colorectal cancer colorectal cancer tumor markers

Objective:To investigate the value of tumor markers in colorectal cancer with multi-slice spiral CT in the diagnosis of elderly colorectal cancer.Methods:From January 2016 to September 2017 year period, 73 elderly patients with colorectal cancer treated in our hospital were selected as observation group;64 elderly patients with intestinal benign lesions were selected as control group during the same period. Serum samples were collected to detect contents of CEA, CA72-4, CA19-9 and CYFRA21-1 by Roche luminous immunoassay analyzer, and multi slice spiral CT was used.Results:Serum levels of CEA, CA72-4, CA19-9 and CYFRA21-1 levels of the observation group were significantly higher than that of the control group;the positive rate of CEA, CA72-4, CA19-9, CYFRA21-1 and their combined detection were all significantly higher than that of the control group;positive rate of MSCT in the observation group was higher than the control group;positive rates of tumor markers combining with MSCT examination of colorectal cancer were higher than that of combined detection of tumor markers and MSCT examination;but there was no significant difference in positive rate of combined detection of tumor markers and the positive rate of MSCT detection of colorectal cancer.Conclusion:Colorectal cancer tumor markers combined with multi-slice spiral CT in the diagnosis of colorectal cancer in elderly has important research value, can significantly improve the positive rate of diagnosis.

Value of Multi-slice Spiral CT in the Diagnosis and Resectability of Pancreatic Cancer

Objective:To analyze the value of multislice spiral CT in the diagnosis and resectability of pancreatic cancer.Method:56 patients with pancreatic cancer treated in our hospital from January 2018 to October 2019 were selected as the research subjects.All patients underwent multi-phase scanning by multislice spiral CT.According to the results of the images,observe whether the pancreatic cancer has affected the blood vessels surrounding the pancreas,evaluate the resectability based on the results of the examination,and analyze the final results of the operation which was taken as the standard.Results:all the 56 cases presented slightly low density or equal density,and 28 cases had complete outline.Multi-slice spiral assessment of patients’vascular invasion types found that 192 branches can be resected with 70 branches cannot;Multi-slice spiral assessment of the main arterial and venous invasion grades around the pancreas of the patients found that 212 branches can be resected with 50 branches cannot;Multi-slice spiral CT was used to evaluate the resectability of pancreatic cancer compared with surgical results.The accuracy of resectable types of vascular invasion was 72.52%;the accuracy of resectable vascular invasion grades was 79.39%.Conclusion:the application of multi-slice spiral CT in the diagnosis of pancreatic cancer can provide a clear understanding of the condition of vascular invasion and distant metastasis,and the accuracy of assessing resection can reach more than 70.00%,which provides a reference for clinical application.

Investigation on the optical scan condition for imaging of multi-slice spiral CT liver perfusion in rats

Background Multi-slice CT liver perfusion has been widely used in experimental studies of hemodynamic changes in liver lesions, and is usually performed as an adjunct to a conventional CT examination because of its high temporal and spatial resolution, simple protocol, good reproducibility, and ability to measure hemodynamic changes of liver tissues at the capillary level. Experimental rat models, especially those of induced liver cancer, are often used in studies of hemodynamic changes in liver cancer. Carcinogenesis in rats has a similar pathological progression and characteristics resembling those in human liver cancer; as a result, rat models are often used as ideal animal models in the study of human liver cancer. However, liver perfusion imaging in rats is difficult to perform, because rats＇ livers are so small that different concentrations, flow rates, and dose of contrast agents during the CT perfusion scanning can influence the quality of liver perfusion images in rats. The purpose of this study, therefore, was to investigate the optimal scan protocol for the imaging of hepatic perfusion using a deconvolution mathematical method in rats by comparing the results of rats in different injection conditions of the contrast agent, including concentration, rate and time. Methods Plain CT scan conditions in eighty 2-month-old male Wistar rats were 5.0 mm slice thickness, 5.0 mm interval, 1.0 pitch, 120 kV tube voltage, 60 mA tube current, 512x512 matrix, and FOV 9.6 cm. Perfusion scanning was carried out with different concentrations of diatrizoate （19%, 38%, 57%, and 76%）, different injection rates （0.3 and 0.5 ml/s）, and different injection times （1, 2-3, 4-5, and 6 seconds）. The above conditions were randomly matched and adjusted to determine the best perfusion scan protocol. Three-phase contrast-enhanced scanning was performed after CT perfusion. Histological examination of the liver tissues with hematoxylin and eosin stains was done after CT scanning. Results When the concentration of the contrast agent was 19% or 38%, no pseudo-color map was created. The viscosity increased when the concentration of the contrast agent was 76%; so it is difficult to inject the contrast agent at such a high concentration. Also no pseudo-color map was generated when the injection time was short （1, 2-3, and 4-5 seconds） or the injection rate was low （0.3 ml/s）. The best perfusion images and perfusion parameters were obtained during 50 seconds scanning. Each rat was given an injection of 57% diatrizoate at 0.5 mils via the tail vein using a high-pressure syringe for 6 seconds. The perfusion parameters included hepatic blood flow （HBF）, hepatic blood volume （HBV）, mean transit time （MTT） of the contrast agent, capillary permeability-surface area product （PS）, hepatic arterial index （HAl）, hepatic artery perfusion （HAP）, and hepatic portal perfusion （HPP）. All these parameters reflected the perfusion status of liver parenchyma in normal rats. Three phases of enhancement were modified according to the time-density curves （TDCs） of the perfusion imaging： hepatic arterial phase （7 seconds）, hepatic portal venous phase （15 seconds）, and a delayed phase （23-31 seconds）. On examination by microscopy, the liver tissues were pathologically normal. Conclusions The appropriate protocol with multi-slice spiral CT liver perfusion reflected normal liver hemodynamics in rats. This study laid a solid foundation for further investigation of the physiological characteristics of liver cancer in a rat model, and was an important supplement to and reference for conventional contrast-enhanced CT scans.

Diagnostic value of multi-slice spiral CT in aortic dissection

Background Aortic dissection occurs at a low incidence, but is associated with high mortality. It is generally acute onset, complicated and is often misdiagnosed; therefore is a macro vascular disease that poses major threat on patients’ lives. Timely diagnosis and management are essential, so we investigated the diagnostic value of multi-slice spiral CT in aortic dissection. Methods clinical data from 21 patients with confirmed aortic dissection were retrospectively analyzed. All patients had undergone plain and contrasted multi-slice spiral CT scans. Results true lumen and pseudo cavity were clearly revealed in all 21 patients, of which 17 showed intimal flap, four showed intimal calcification and inward displacement, while 2 had thrombosis in the pseudo cavity. As for classification among these 21 patients, 9 had type Ⅰ aortic dissection, including two patients with innominate artery involvement, 1 with celiac trunk involvement and 2 with left renal artery involvement; 2 had type Ⅱ aortic dissection, including 1 patient with innominate artery involvement; Another ten patients had type III aortic dissection, including 2 patients with left subclavian artery involvement and 1 with celiac trunk involvement. Nineteen out of 21 patients had clearly revealed initial rupture. Conclusion multi-slice spiral CT is characterized by rapidness, non-invasiveness and accuracy. It provides clear visualization of the location and scope of aortic dissection, location of the rupture as well as the valves, which makes it a first-choice imaging approach for the diagnosis of aortic dissection.

Multi-slice spiral CT 3-dimensional reconstruction tech-nique to treat multi-segmental degenerative spinal steno-sis with traumatic instability of lower cervical spine

Objective: To study the feasibility of multi-slice spiral computed tomography (MSCT) 3-dimensional reconstruc-tion technique in assisting cervical pedicle screw fixation (PSF) and double-door laminoplasty to treat multi-segmen-tal degenerative spinal stenosis with traumatic instability (MDSTI) of lower cervical spine.Methods: From September 2006 to August 2007, PSF combined with double-door laminoplasty was performed in 9 patients with MDSTI of lower cervical spine. MSCT 3-dimensional reconstruction techniques, including volume rendering (VR) and multi-planar reconstruction (MPR), were used to assist preoperative diagnosis and measurement to guide the procedure. MPR was performed after operation. In coronal view, the degree of screw perforation was mea-sured precisely and the different positions of pedicle screws were divided into three grades according to Richter's method. In axial view, the canal sagittal diameter and trans-verse area of every laminoplasty level were measured.Results: Nine patients with MDSTI of lower cervical spine underwent PSF (total 44 screws). According to the classification of Richter, 72.7% (32/44) was in Grade 1 and 27.3% (12/44) was in Grade 2. No screw perforation occurred in Grade 3 and no screw revision was done for misplacement.No iatrogenic damage was observed. Double-door laminoplasty was performed in total 42 volumes. The post-operative sagittal diameter and transverse area of cervical spinal canal were significantly increased (P<0.05). The confi-dence intervals of mean increased ratio were 23.43%-40.65% in sagittal diameter and 23.18%-42.07% in transverse area. Six months after laminoplasty, based on MSCT axial view, complete union between "open door" and allograft bone was obtained in 76.19% of volumes (32/42), and allograft bone was absorbed partly in 23.81% (10/42). A solid union in bilateral gutters was achieved in all cases. They were followed up from 6 months to 1 year (mean 7.8 months). Post-operative neural function recovery in two cases improved 2 ASIA grade, 5 cases improved 1 grade and 2 cases remained the same as preoperative grade. No cases had lower ASIA grade.Conclusion: Assisted with MSCT 3-dimensional re-construction technique, PSF combined with double-door laminoplasty can be performed more safely and effectively to treat patients with MDSTI of lower cervical spine.

Performance analysis of single-focus phase singularity based on elliptical reflective annulus quadrangle-element coded spiral zone plates

Optical vortices generated by the conventional vortex lens are usually disturbed by the undesired higher-order foci,which may lead to additional artifacts and thus degrade the contrast sensitivity. In this work, we propose an efficient methodology to combine the merit of elliptical reflective zone plates(ERZPs) and the advantage of spiral zone plates(SZPs) in establishing a specific single optical element, termed elliptical reflective annulus quadrangle-element coded spiral zone plates(ERAQSZPs) to generate single-focus phase singularity. Differing from the abrupt reflectance of the ERZPs, a series of randomly distributed nanometer apertures are adopted to realize the sinusoidal reflectance. Typically, according to our physical design, the ERAQSZPs are fabricated on a bulk substrate;therefore, the new idea can significantly reduce the difficulty in the fabrication process. Based on the Kirchhoff diffraction theory and convolution theorem, the focusing performance of ERAQSZPs is calculated. The results reveal that apart from the capability of generating optical vortices,ERAQSZPs can also integrate the function of focusing, energy selection, higher-order foci elimination, as well as high spectral resolution together. In addition, the focusing properties can be further improved by appropriately adjusting the parameters, such as zone number and the size of the consisted primitives. These findings are expected to direct a new direction toward improving the performance of optical capture, x-ray fluorescence spectra, and forbidden transition.

Terahertz quasi-perfect vortex beam with integer-order and fractional-order generated by spiral spherical harmonic axicon

We propose a new method to generate terahertz perfect vortex beam with integer-order and fractional-order. A new optical diffractive element composed of the phase combination of a spherical harmonic axicon and a spiral phase plate is designed and called spiral spherical harmonic axicon. A terahertz Gaussian beam passes through the spiral spherical harmonic axicon to generate a terahertz vortex beam. When only the topological charge number carried by spiral spherical harmonic axicon increases, the ring radius of terahertz vortex beam increases slightly, so the beam is shaped into a terahertz quasi-perfect vortex beam. Importantly, the terahertz quasi-perfect vortex beam can carry not only integer-order topological charge number but also fractional-order topological charge number. This is the first time that vortex beam and quasi-perfect vortex beam with fractional-order have been successfully realized in terahertz domain and experiment.

Device-assisted enteroscopy: Are we ready to dismiss the spiral?

Motorized spiral enteroscopy(MSE)is the latest advance in device-assisted enteroscopy.Adverse events related to MSE were discussed in a recent large systematic review and meta-analysis and were directly compared with those of balloon enteroscopy in a case-matched study and a randomized controlled trial.Following the real-life application of MSE,an unexpected safety issue emerged regarding esophageal injury and the technique has been withdrawn from the global market,despite encouraging results in terms of diagnostic and therapeutic yield.We conducted an Italian multicenter real-life prospective study,which was prematurely terminated after the withdrawal of MSE from the market.The primary goals were the evaluation of MSE performance(both diagnostic and therapeutic)and its safety in routine endoscopic practice,particularly in the early phase of introduction in the endoscopic unit.A subanalysis,which involved patients who underwent MSE after unsuccessful balloon enteroscopy,demonstrated,for the first time,the promising performance of MSE as a rescue procedure.Given its remarkable performance in clinical practice and its potential role as a backup technique following a previously failed enteroscopy,it may be more appropriate to refine and enhance MSE in the future rather than completely abandoning it.

Fusion of Spiral Convolution-LSTM for Intrusion Detection Modeling

Aiming at the problems of low accuracy and slow convergence speed of current intrusion detection models,SpiralConvolution is combined with Long Short-Term Memory Network to construct a new intrusion detection model.The dataset is first preprocessed using solo thermal encoding and normalization functions.Then the spiral convolution-Long Short-Term Memory Network model is constructed,which consists of spiral convolution,a two-layer long short-term memory network,and a classifier.It is shown through experiments that the model is characterized by high accuracy,small model computation,and fast convergence speed relative to previous deep learning models.The model uses a new neural network to achieve fast and accurate network traffic intrusion detection.The model in this paper achieves 0.9706 and 0.8432 accuracy rates on the NSL-KDD dataset and the UNSWNB-15 dataset under five classifications and ten classes,respectively.

Effectiveness of magnetic resonance imaging and spiral computed tomography in the staging and treatment prognosis of colorectal cancer

BACKGROUND Colorectal cancer(CRC)is a prevalent cancer type in clinical settings;its early signs can be difficult to detect,which often results in late-stage diagnoses in many patients.The early detection and diagnosis of CRC are crucial for improving treatment success and patient survival rates.Recently,imaging techniques have been hypothesized to be essential in managing CRC,with magnetic resonance imaging(MRI)and spiral computed tomography(SCT)playing a significant role in enhancing diagnostic and treatment approaches.AIM To explore the effectiveness of MRI and SCT in the preoperative staging of CRC and the prognosis of laparoscopic treatment.METHODS Ninety-five individuals admitted to Zhongshan Hospital Xiamen University underwent MRI and SCT and were diagnosed with CRC.The precision of MRI and SCT for the presurgical classification of CRC was assessed,and pathological staging was used as a reference.Receiver operating characteristic curves were used to evaluate the diagnostic efficacy of blood volume,blood flow,time to peak,permeability surface,blood reflux constant,volume transfer constant,and extracellular extravascular space volume fraction on the prognosis of patients with CRC.RESULTS Pathological biopsies confirmed the following CRC stages:23,23,32,and 17 at T1,T2,T3,and T4,respectively.There were 39 cases at the N0 stage,22 at N1,34 at N2,44 at M0 stage,and 51 at M1.Using pathological findings as the benchmark,the combined use of MRI and SCT for preoperative TNM staging in patients with CRC demonstrated superior sensitivity,specificity,and accuracy compared with either modality alone,with a statistically significant difference in accuracy(P<0.05).Receiver operating characteristic curve analysis revealed the predictive values for laparoscopic treatment prognosis,as indicated by the areas under the curve for blood volume,blood flow,time to peak,and permeability surface,blood reflux constant,volume transfer constant,and extracellular extravascular space volume fraction were 0.750,0.683,0.772,0.761,0.709,0.719,and 0.910,respectively.The corresponding sensitivity and specificity values were also obtained(P<0.05).CONCLUSION MRI with SCT is effective in the clinical diagnosis of patients with CRC and is worthy of clinical promotion.

水平多层spiral型地埋管数值模拟研究及换热特性分析

本文基于COMSOL软件建立了水平spiral型多层地埋管群传热三维数值模拟模型,并对其换热性能和温度场进行分析研究。结果表明:对比水平spiral多层并联管群来说,远离注入端的地埋管管内温度相对较低。地埋管群周围地层温度有所升高,远离注入端的地层温度变化相对较小。地埋管群的换热量随循环流体的流速增加而增加,但增幅降低。在进行换热器设计时,应合理控制循环水的流速。3层螺旋地埋管群的换热量略高,但层间干扰明显,建议选用2层并联螺旋管群。

Validation of a novel imaging approach using multi-slice CT and cone-beam CT to follow-up on condylar remodeling after bimaxillary surgery

The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography （MSCT） and postoperative cone-beam computed tomography （CBCT） images. Second, the reliability and accuracy of this condylar volume quantification method was assessed. The mandibles of 20 patients （11 female and 9 male） who underwent bimaxillary surgery were semi-automatically extracted from MSCT/CBCT scans and rendered in 3D. The resulting condyles were spatially matched by using an anatomical landmark-based registration procedure. A standardized sphere was created around each condyle, and the condylar bone volume within this selected region of interest was automatically calculated. To investigate the reproducibility of the method, inter- and intra-observer reliability was calculated for assessments made by two experienced radiologists twice five months apart in a set of ten randomly selected patients. To test the accuracy of the bone segmentation, the inner and outer bone structures of one dry mandible, scanned according to the clinical set-up, were compared with the gold standard, micro-CT. Thirty-eight condyles showed a significant （P〈O.05） mean bone volume decrease of 26.4%_ 11.4% （502.9 mm3＋ 268.1 mm3）. No significant effects of side, sex or age were found. Good to excellent （ICC〉 0.6） intra- and inter-observer reliability was observed for both MSCT and CBCT. Moreover, the bone segmentation accuracy was less than one voxel （0.4 mm） for MSCT （0.3 mm __. 0.2 mm） and CBCT （0.4 mm _ 0.3 mm）, thus indicating the clinical potential of this method for objective follow-up in pathological condylar resorption.