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.

Three-dimensional Imaging of Multi-slice Spiral CT in Bronchial Artery Correlative Study on Blood Supply of Central Lung Cancer and Its Clinical Significance

Objective: To evaluate three-dimensional bronchial artery imaging charactersin central lung cancer and applied values with multi-slice spiral CT (MSCT) to provide theoreticalevidence on blood supply and intervention therapy. Methods: Eighteen patients with central lungcancer underwent MSCT with real time helical thin-slice CT scanning. Three-dimensional bronchialartery reconstruction was done at the console work-station. The space anatomical characters ofbronchial artery were observed through different rotations. Results: For 6 cases, thethree-dimensional images of bronchial artery (33.33%) could exactly show the origins, the routes(lung inner segment and mediatism segment) and the diameters of bronchial arteries. Vision rate ofbronchial arteries was the highest in pulmonary artery stricture and truncation groups, and thevessels' diameter became larger apparently. These characters demonstrated blood supply of this kindof central lung cancer come from bronchial artery. Volume rendering images were the best ones amongthree-dimensional images. Conclusion: Three-dimensional imaging with MSCT in bronchial artery canreveal the anatomical characters of bronchial artery and provide theoretical evidence on bloodsupply and intervention therapy of central lung cancer.

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.

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） years and no obvious organic heart disease. Before ablation, patients received MSCT to generate 3-dimentional image of the left atrium （LA） and proximal PVs. Patients then underwent segmental radiofrequency ablation ofPV 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≥1 time 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.

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.

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.

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.

Application of Dual-Source CT TurboFlash Coarse Pitch Scanning in Coronary Artery Imaging

Objective: To compare and analyze the image quality and radiation dose of three scanning modes of dual-source CT coronary artery retrospectively, and to discuss the application value of TurboFlash coarse pitch scanning mode. Methods: The imaging data of 100 patients who underwent CT coronary angiography (CCTA) using Siemens force CT retrospective gated triggering spiral scan (RES-SPIRAL), adaptive prospective gated triggering sequence scan (SEQ) and prospective coarse pitch scan (TurboFlash) retrospectively was collected. The image quality was evaluated by objective and subjective methods. The effective radiation dose of patients was compared and analyzed, and the indications of the three scanning modes were analyzed. The application value of dual-source CT TurboFlash coarse pitch scanning in coronary artery imaging was evaluated. Results: The results showed that the left main coronary artery, the right coronary artery and their tertiary branches could be clearly displayed in the three groups of images: the left anterior descending branch, the left circumflex branch, and their three-level branches. There was no statistical difference in subjective image quality among the three groups of pictures (P > 0.05). There was no statistical difference in objective evaluation indexes, such as CT value, SNR, CNR and Noise among the three groups (P > 0.05). The patient radiation dose results showed that the effective radiation dose ED of RES-SPIRA scan was (9.22 ± 1.33) mSv. The dose of SEQ was (2.88 ± 2.47) mSv, and the dose of TurboFlash was (0.51 ± 0.16) mSv. There was significant difference in comparison of the three groups (P 0.05). RES-spiral scanning had the highest radiation dose and TurboFlash coarse pitch scanning (TurboFlash) had the lowest radiation dose. Conclusion: TurboFlash coarse pitch scanning is low in dosage, fast in speed and wide in adaptability. It is especially suitable for the elderly, children, coma and other patients who cannot cooperate with breath-holding examination, as well as for the screening and examination of coronary artery diseases in asymptomatic population. Undoubtedly, it is a worthy method of heart coronary artery examination.

Diameters and form of skull base foramen ovale measured by three-dimensional spiral CT thin-slice scan in healthy adults

BACKGROUND： The accurate measurements of various data of the bone diameters of foramen ovale of living person can change the methods of puncturing trigeminal gasserian ganglion via foramen ovale for treating trifacial neuralgia from the experience of puncture operator only to puncture by taking the objective data of measurement as the evidence, which is good for improving the accuracy of puncturing trigeminal ganglion and reducing side effects. OBJECTIVE ： To observe the forms of foramen ovales in healthy adults displayed by volume rendering and multi-planar reconstruction after three-dimensional spiral CT thin-slice scan of skull base, and measure the longitudinal diameter and transverse diameter. DESIGN ： A repetitive observation and measurement SETTINGS ： Department of Neurosurgery and Department of Medical Imaging, Foshan Hospital of Traditional Chinese Medicine. PARTICIPANTS： Fifty healthy adults （100 sides）, who were examined with three-dimensional spiral CT scan, were randomly selected from the Department of Medical Imaging, Foshan Hospital of Traditional Chinese Medicine from January 2005 to January 2006, including 26 males and 24 females, aged 25-68 years with an average of 48 years old. They were all informed and agreed with the examination. METHODS ： The subjects were examined with the Philips 16-slice spiral CT-Mx 8000 IDT CT apparatus （Philips Company, Holland）, the scanning ranged from 2 cm below the canthomeatal line to the level of suprasellar cistem. The width of collimator was 0.75 mm, pitch was 0.663; tube current was 350 mA, voltage was 120 kV, resolution was 512×512 matrix; slice thickness of reconstruction was 1 mm, and interval was 0.5 mm. After the three-dimensional spiral CT thin-slice scan of skull base, the image post-processing techniques including volume rendering and multi-planar reconstruction were applied to observe the forms of foramen ovales, and measure the size, longitudinal diameter and transverse diameter of the foramen ovales. The figures of the foramen ovales were drawn with mouse along the boundary of bone porous margin and soft tissue. According to the indications, the diameters were measured with computer to observe the forms of foramen ovales. MAIN OUTCOME MEASURES ： The longitudinal diameter, transverse diameter and form of foramen ovales were observed. RESULTS： All the 50 healthy adults （100 sides） were involved in the analysis of results. （1） It was observed in the volume rendering images that foramen ovales had four forms of oval shape （77 sides）, kidney shape （12 sides）, round shape （7 sides）, ribbon shape （4 sides）. （2） The longitudinal diameters of left and right foramen ovales were （7.67±1.32） and （7.98±1.45） mm, and the transverse diameters were （4.04±0.83）, （4.09±1.07） mm; There was no obvious difference between left and right longitudinal diameters （t = 1.63, P = 0.11 ）, and left and right transverse diameters were close （t = 0.45, P= 0.65）. CONCLUSION ： The non-invasive techniques of volume rendering and multi-planar reconstruction after three-dimensional spiral CT thin-slice scan can clearly display the formand size of foramen ovale in healthy adults.

Diagnostic Value of Spiral CT Chest Enhanced Scan in Adult with Active Pulmonary Tuberculosis

Aim:To explore the diagnostic value of spiral CT chest enhanced scan for adults with active pulmonary tuberculosis.Methods:The clinical data of 60 adult patients with active pulmonary tuberculosis who were treated in our hospital from January 2018 to November 2019 were retrospectively analyzed.All patients underwent conventional chest radiography and spiral CT chest enhanced scan.The number of tuberculosis diagnosis,the detection rate of special site lesions,and the detection rate of active pulmonary tuberculosis signs by the two methods were compared.Results:In 60 patients,the pathological results confirmed the existence of 75 tuberculosis lesions.The detection rate of spiral CT was 98.67%,which was not statistically significant compared with the detection rate of 92.00%(P>0.05)in the conventional chest X-ray.The detection rate of spiral CT enhanced scans for tuberculosis lesions in special sites was 100.00%,which was significantly higher than that of conventional chest X-ray of 7.69%,and the accuracy rate of active pulmonary tuberculosis signs was 98.85%higher than that of conventional chest X-ray of 79.31%.P<0.05).The difference was statistically significant(P<0.05).Conclusion:Spiral CT chest enhanced scan can not only find special tuberculosis lesions that cannot be detected by conventional chest radiography,but also accurately determine active pulmonary tuberculosis in adults,which is of high diagnostic value.

肺栓塞诊断中多层螺旋CT双期动态增强扫描技术的应用研究

目的 分析研究肺栓塞诊断中应用多层螺旋CT双期动态增强扫描技术的应用价值。方法 选取河南省胸科医院2020年2月至2022年6月收治的50例疑似肺栓塞患者,选择SOMATOM Definition Flash双源CT扫描机开展胸部平扫和肺动脉期、肺静脉期双期动态增强CT扫描,分析双期动态增强扫描图像;以综合评定结果为金标准,计算双期动态增强CT扫描检查结果。结果 分析多层螺旋CT双期动态增强扫描图像发现,41例患者诊断为肺栓塞,能精确发现145处栓子,其中13处为左右肺动脉主干,57处为叶动脉,55处为段动脉,18处为亚段动脉,2处为亚亚段动脉。50例患者经综合评估,结果为阳性48例,阴性2例,双期动态增强CT扫描检查结果为阳性46例,阴性4例。双期动态增强CT扫描检查敏感度为95.83%(46/48),特异度为100.00(2/2),准确度为96.00%(48/50)。结论 临床诊断肺栓塞时采用多层螺旋CT双期动态增强扫描技术具有显著的检测和诊断效果,准确性、特异性及敏感度均较高,值得应用。

IEEE 1149.10协议的多扫描通道同步测试数据包优化策略

为了提高IEEE 1149.10协议中多扫描通道同步测试数据包编码效率,提出一种基于多策略改进野狗算法(mMDOA)的多扫描通道数据包优化方法。首先,多策略改进野狗算法使用自适应追击步长与螺旋游走结合的迫害策略,并通过基于反向精英的食腐策略,帮助算法跳出局部最优,提升全局搜索的能力;其次,根据IEEE 1149.10多扫描通道同步测试数据包编码格式,提出新的扫描通道分组方法,通过扫描数据大小和数据交织大小计算组内扫描通道数目,以组内长度差为目标函数,使用mMDOA选择组内扫描通道。经实验验证,使用mMDOA算法能减少约30%数据包数量,并有效地缩短了数据包编码时间。

Using receiver operating characteristic curves to evaluate the diagnostic value of the combination of multislice spiral CT and alpha-fetoprotein levels for small hepatocellular carcinoma in cirrhotic patients

BACKGROUND： The various combination of multiphase enhancement multislice spiral CT （MSCT） makes the diagno- sis of a small hepatocellular carcinoma （sHCC） on the back- ground of liver cirrhosis possible. This study was to explore whether the combination of MSCT enhancement scan and alpha-fetoprotein （AFP） level ficiency for sHCC. could increase the diagnostic ef- METHODS： This study included 35 sHCC patients and 52 cir- rhotic patients without image evidence of HCC as a control group. The diagnoses were made by three radiologists em- ploying a 5-point rating scale, with postoperative pathologic results as the gold standard. Receiver operating characteristic （ROC） curve analysis was performed to evaluate the diag- nostic value of the three MSCT combination modes （arterial phase＋portal-venous phase, arterial phase＋delayed phase, arterial phase＋portal-venous phase＋delayed phase） and AFP levels for sHCC on the background of liver cirrhosis. RESULTS： The area under ROC curve （AUC）, sensitivity, and specificity of the combination of arterial phase＋portal- venous phase＋delayed phase were 0.93, 93%, and 82%, respectively. The average AUC of the arterial phase＋portal- venous phase＋delayed phase combination was significantly greater than that of the arterial phase＋portal-venous phase （AUC=0.84, P=0.01） and arterial phase＋delayed phase （AUC=0.85, P=0.03）. Arterial phase＋portal-venous phase had a smaller AUC （0.84） than arterial phase＋delayed phase （0.85）, but the difference was insignificant （P=0.15）. After combining MSCT enhancement scan with AFP, the AUC, sensitivity, and specificity were 0.95, 94%, and 83%, respectively, indicating a greatly increased diagnostic efficiency for sHCC. CONCLUSIONS： The combination of AFP and 3 phases MSCT enhancement scan could increase the diagnostic efficiency for sHCC on the background of liver cirrhosis. The application of ROC curve analysis has provided a new method and reference in HCC diagnosis.

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.

Spiral CT localization of pancreatic function-ing islet cell tumors

BACKGROUND: Surgeons are always concerned about the localization of pancreatic functioning islet cell tumor. If the tumor is accurately localized before operation, resection of the pancreatic body and tail without intention can be avoided. The purpose of this study was to evaluate spiral CT localization of pancreatic functioning islet cell tumors and CT techniques. METHODS: CT manifestations in 6 patients with clinically and pathologically proved pancreatic functioning islet cell tumors ware analyzed retrospectively. RESULTS: In 4 patients with insulinomas and 2 patients with glucagonomas, 5 were localized accurately by CT be- fore surgery and 1 was detected retrospectively. The en- hancement of tumors was greater than that of normal pan- creas in arterial phase and pancreatic parenchymal phase. Four patients showed mild high-density and 2, iso-density in the portal venous phase. CONCLUSION: Spiral CT multi-phase enhanced scan with 1.5 ml/kg contrast agent and 2-5 mm slice width can loca- lize functioning islet cell tumors accurately.

Spiral multi-phase CT in evaluating resectability of pancreatic carcinoma

Objectives: To evaluate the specific manifestations of pancreatic carcinoma on spiral multi-phase CT and its resectability before operation. Methods: Ninety-seven patients were confirmed oper- atively and pathologically. Enhanced CT scan was performed with intravenous injection bolus of ap- proximately 75-120 ml (1-1.5 ml/kg body weight) contrast medium at a rate of 2.5-3 ml/s. In 68 pa- tients receiving dual-phase scan, the delayed scan time of arterial and venous phases was 18-20 s and 60-70 s, respectively, and in 29 patients receiving three-phase scan, the delayed scan time of arterial, pancreatic and portal venous phases was 18 s, 40 s and 75 s, respectively, with a slice of 3-5 mm thick- ness, a pitch of 1-1.5, and a reconstruction interval of 2.5-4.8 mm. Results: Positive and negative predictive values of un- resectable tumors were 97.65% and 75.86%, respec- tively. The sensitivity and accuracy were 90.67% and 90. 72%, respectively. Positive predictive values of dual-phase and three-phase were 95.83% and 100%, respectively; negative predictive values were 75% and 77.78%, respectively. Conclusions: Spiral multi-phase CT is superior in re- vealing the involvement of peripancreatic vessels, the invasion of the neighboring organs, the size, shape and range of carcinoma, and the metastasis of liver and lymph node. The predictability of resection is obviously increased for patients with pancreatic car- cinoma.

Arterial phase of biphase enhancement spiral CT in diagnosis of small hepatocellular carcinoma

Objectives: To evaluate the value of the arterial phase(AP) of biphase enhanced spiral CT(SCT) in the di-agnosis of small HCC and to investigate the criteria,initial time, ending time and duration of AP.Methods: From May 1995 to March 1999, patients withsmall HCC proved surgically and pathologically in-cluding 49 patients (n=53) in group A, 148 (n=186) ingroup B and 52 (n=52) in group C were collected.Biphase dynamic enhanced SCT scans were performedin all patients of the three groups and additional sin-gle-level dynamic scans only done in the group C. Thedetectability, diagnostic accuracy of lesions and en-hancement of the lesions in AP were analyzed statisti-cally. In addition, the initial time, ending time andduration of AP were measured.Results: The results of the group A showed the de-tectability of small HCC was 88.68% in AP and90.57% in both phases, higher than those by ultra-sound. Markedly enhanced lesions in AP accounted for76% and 78% in the groups B and C respectively. Theinitial time, ending time and duration of AP measuredon single-level dynamic scans were 16.9s, 39.6s and22.7s on average respectively.Conclusions: The biphase dynamic SCT especially itsarterial phase appears to be very valuable in diagnosingsmall HCCs. In light of short duration of AP, under-standing and strict control of AP is obviously impera-tive.

维持性血液透析患者血清内脂素与冠状动脉钙化的相关性研究

目的探讨维持性血液透析(maintenance hemodialysis,MHD)患者血清内脂素与冠状动脉钙化(coronary artery calcification,CAC)的相关性。方法应用横断面研究法,收集2023年7月1日至2024年2月29日首都医科大学附属北京潞河医院的MHD患者的临床资料,检测血清内脂素水平,应用低剂量胸部多层螺旋电子计算机断层扫描(computed tomography,CT)评估患者CAC情况并分组比较,应用多因素Logistic回归法分析CAC的独立影响因素;应用受试者工作特征(receiver operating characteristic,ROC)曲线分析影响因素对MHD患者发生CAC的预测价值。结果本研究共纳入135例MHD患者,分为无CAC组(n=39)和CAC组(n=96);2组患者的年龄、合并糖尿病、血清内脂素、血糖、血钠、尿素清除指数(urea clearance index,Kt/V)差异均有统计学意义(P<0.05);多因素Logistic回归分析发现高龄、血清内脂素升高以及合并糖尿病是MHD患者发生CAC的独立危险因素。ROC曲线显示,血清内脂素单独预测CAC的曲线下面积(area under the curve,AUC)为0.751(P<0.01),具有较高的预测价值。结论血清内脂素升高是MHD患者发生CAC的独立危险因素,可能成为预测CAC的生物学指标。