WorldWideScience

Sample records for dynamic spiral ct

  1. Contrast enhancement characteristics of hepatocellular carcinoma on two-phase dynamic scan with spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Dae Young; Choi, Byung Ihn; Han, Joon Koo; Han, Man Chung [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

    1994-12-15

    The purpose of this study was to characterize the enhancing patterns of hepatocellular carcinoma (HCC) on two-phase dynamic incremental liver scan with spiral CT. Two-phase dynamic incremental liver scan using spiral CT was performed on 230 lesions in 107 patients with HCC. CT scanning was performed with a table speed of 13 mm/sec and a section thickness of 10 mm; 120 mL of contrast medium was injected intravenously with a automatic injector at the rate of 3 mL/sec. CT scans were started 35 sec(early phase) and 3 min(delayed phase) after beginning injection of contrast medium. The tumors were divided into 2 groups according to size({<=}3cm and > 3cm), the contrast enhancement patterns of HCCs and capsules in the early and delayed phases were analyzed in each group. Most of HCCs appeared as high-attenuating lesions in the early phase(75% in tumors smaller than 3cm and 61 % in tumors larger than 3cm), and as low-attenuating lesions in the delayed phase(68% in tumors smaller than 3cm and 90% in tumors larger than 3cm). Forty-eight percent of HCCs smaller than 3cm and 58% of HCCs larger than 3 cm were high-attenuating in the early phase and low-attenuating in the delayed phase. Thirty-two percent of capsules were low- or iso-attenuating in the early phase and high-attenuating in the delayed phase. Capsules were demonstrated in 22% in HCCs smaller than 3cm and 67% in HCCs larger than 3 cm (p <. 01). Two-phase dynamic scan with spiral CT is useful in the diagnosis of HCC because of a precise display of hemodynamic characteristics of HCCs.

  2. Correlation between Dynamic Spiral-CT Enhancement Parameters and Tumor Angiogenesis in Renal Cell Carcinomas

    Institute of Scientific and Technical Information of China (English)

    Jinhong Wang; Weixia Chen; Xiuhui Zhang; Pengqiu Min; Rongbo Liu; Hengxuan Yang

    2005-01-01

    OBJECTIVE To prospectively investigate the correlation between the enhancement parameters of a dynamic-CT (D-CT) scan for renal cell carcinomas (RCC) and the carcinoma tissue microvessel density (MVD) in renal cell carcinomas (RCC).METHODS Twenty-four cases of renal cell carcinoma verifyied by histopathology were scanned via dynamic-CT, followed by a whole kidney scan. Enhancement parameters were derived as follows .The slope of the contrast media uptake curve (S), area under the curve(AR), the density difference before and after tissue enhancement (△HU) and tissue blood ratio (TBR) were calculated for all lesions. Time-density curve types were ranked from the lowest to the highest of the slope of the contrast media uptake curve (S) as type A, B and C. Pathologic slides corresponding to the CT imagings were subjected to CD34 monoclonal antibodies, then were evaluated with an image analyzer to count hot spots of MVD. By using the Spearman rank correlation tests, statistical analysis was performed to determine the strength of the relationship between enhancement parameters and MVD determinations.RESULTS The carcinoma tissue MVD showed a direct correlation with the enhancement parameters of D-CT (r=0.54, r=0.62, r=0.55, r=0.64, r=0.44,P< 0.05). Moreover the S, △HU, TBR and type curves all demonstrated a strong correlation with the MVD. By analyzing the various enhancement parameters of the time-density curves, the relationship between the enhancement CT parameters corresponding to the tumor's MVD was identified.CONCLUSION A dynamic spiral-CT scan may be a helpful method as a measurement of tumor angiogenesis in vivo in RCC.

  3. A case of occult insulinoma localized by pancreatic dynamic enhanced spiral CT

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Insulinomas are the most common category of pancreatic endocrine tumors,with an annual incidence of 1-4 cases per million people.Most are intrapancreatic,benign and solitary.Therefore,they have an excellent prognosis after surgical resection.However,the localization diagnosis of insulinomas still poses a challenge to surgeons and radiologists.In this case,the tumor was occult and could not be found by either abdominal enhanced spiral computed tomography(CT)or ultrasonography.Therefore,we tried a new method ...

  4. Motion estimation and compensation in dynamic spiral CT reconstruction; Estimation et compensation de mouvement en reconstruction dynamique de tomodensitometrie helicoidale

    Energy Technology Data Exchange (ETDEWEB)

    Kimdon, J.; Grangeat, P.; Koenig, A.; Bonnet, St

    2004-07-01

    Respiratory and cardiac motion causes blurring in dynamic X-ray Computed Tomography (CT). Fast scans reduce this problem, but they require a higher radiation dose per time period to maintain the signal to noise ratio of the resulting images, thereby magnifying the health risk to the patient. As an alternative to increased radiation, our team has already developed a cone-beam reconstruction algorithm based on a dynamic particle model that estimates, predicts, and compensates for respiratory motion in circular X-ray CT. The current paper presents an extension of this method to spiral CT, applicable to modern multi-slice scanners that take advantage of the speed and dose benefits of helical trajectories. We adapted all three main areas of the algorithm: backprojection, prediction, and compensation/accumulation. In backprojection, we changed the longitudinal re-binning technique, filter direction, and the method of enforcing the data sufficiency requirements. For prediction, we had to be careful of objects appearing and disappearing as the scanner bed advanced. For compensation/accumulation, we controlled the reconstruction time and combined images to cover a greater longitudinal extent for each phase in the respiratory or cardiac cycle. Tests with moving numerical phantoms demonstrate that the algorithm successfully improves the temporal resolution of the images without increasing the dose or reducing the signal-to-noise ratio. (authors)

  5. Motion estimation and compensation in dynamic spiral CT reconstruction; Estimation et compensation de mouvement en reconstruction dynamique de tomodensitometrie helicoidale

    Energy Technology Data Exchange (ETDEWEB)

    Kimdon, J.; Grangeat, P.; Koenig, A.; Bonnet, St

    2004-07-01

    Respiratory and cardiac motion causes blurring in dynamic X-ray Computed Tomography (CT). Fast scans reduce this problem, but they require a higher radiation dose per time period to maintain the signal to noise ratio of the resulting images, thereby magnifying the health risk to the patient. As an alternative to increased radiation, our team has already developed a cone-beam reconstruction algorithm based on a dynamic particle model that estimates, predicts, and compensates for respiratory motion in circular X-ray CT. The current paper presents an extension of this method to spiral CT, applicable to modern multi-slice scanners that take advantage of the speed and dose benefits of helical trajectories. We adapted all three main areas of the algorithm: backprojection, prediction, and compensation/accumulation. In backprojection, we changed the longitudinal re-binning technique, filter direction, and the method of enforcing the data sufficiency requirements. For prediction, we had to be careful of objects appearing and disappearing as the scanner bed advanced. For compensation/accumulation, we controlled the reconstruction time and combined images to cover a greater longitudinal extent for each phase in the respiratory or cardiac cycle. Tests with moving numerical phantoms demonstrate that the algorithm successfully improves the temporal resolution of the images without increasing the dose or reducing the signal-to-noise ratio. (authors)

  6. Dynamic enhanced multi-slice spiral CT in evaluation of blood flow patterns of solitary pulmonary nodules with enhancement

    Institute of Scientific and Technical Information of China (English)

    LI Shenjiang; XIAO Xiangsheng; LIU Shiyuan; LI Huimin; LI Chengzhou; ZHANG Chenshi; TAO Zhiwei; YANG Chunshan

    2004-01-01

    Objective To investigate the methods of dynamic enhanced multi-slice spiral CT in evaluation of blood flow patterns of solitary pulmonary nodules (SPNs) with enhancement. Methods Seventy eight patients with SPNs (≤4 cm) with strong enhancement underwent dynamic multi-slice spiral CT (Marconi Mx8000) scan before and after contrast enhancement by injecting contrast material with a rate of 4 mL/s. For the 40 patients in protocol one, one scan was obtained every 2 seconds during 15-45 and 75- 105 seconds after injection, while for the 38 patients in protocol two, one scan was obtained every 2 seconds during 11-41 and 71-101 seconds. For all the patients, one scan was obtained every 30 seconds during 2 9 minutes. The section thickness was 2.5 mm for lesions ≤3 cm and 5 mm for lesions >3 cm. Standard algorithm was used in the image reconstruction. Precontrast and postcontrast attenuation on every scan was recorded. The perfusion,peak height, ratio of peak height of the SPN to that of the aorta and mean transit time were calculated. Results The peak height, perfusion, ratio of peak height of the SPN to that of the aorta and mean transit time in malignant SPNs were 34. 85 Hu±10.87 Hu, 30. 37 ml/(min· 100 g)±11. 14 ml/(min · 100 g), 13. 78%±3.96%, 14.19 s±6.19 s respectively in protocol one, while those in protocol two were 36.62 Hu±10.75 Hu,30.01 ml/(min · 100 g)±8.10 ml/(min · 100 g), 14.70 %±4.71%, 13.91 s±4.82 s respectively. No statistically significant differences were found between the peak height (t = 0. 673, P = 0. 503), perfusion (t =0.152, P=0.880), ratio of peak height of the SPN to that of the aorta (t 0.861, P 0.393) and mean transit time (t= 0. 199, P=0. 843) in malignant SPNs measured in protocol one and those measured in protocol two. All mean transit time in protocol two (36/36) were obtained, but only part of them (25/32) were ob tained in protocol one. Conclusion Dynamic enhanced multi-slice spiral CT is a non-invasive method for

  7. Development of phantoms for spiral CT.

    Science.gov (United States)

    Goodenough, D J; Levy, J R; Kasales, C

    1998-01-01

    This paper reports on the development of a new phantom for spiral CT. The phantom meets the increased demands on phantom z-axis uniformity in order that objects from the CT slice, immediately above and below the CT slice of interest, do not contribute perturbing information to the reconstructed CT slice. The phantom depends on formulation of tissue-like materials that can be cast and produced in both geometric and anthropomorphic shapes with sufficient z-axis length to enable unperturbed CT slices of test objects of interest. These materials are then used to produce a series of test objects of CT image quality including low contrast samples that do not require volume averaging or mixing of solutions, and that can reflect sub-slice thickness test objects and supra-slice thickness test objects. The overall phantom and its individual test objects provides meaningful tests of spiral CT image quality including slice sensitivity, CT number linearity and tests of high and low contrast resolution. Schematic designs and actual CT scans are shown. The new spiral phantom appears to meet the increased demands of spiral CT on phantom design, particularly z-axis length, and requirements for low contrast resolution test objects.

  8. Detection of liver metastases: usefulness of dynamic spiral CT during the portal phase with a higher IV injection rate of contrast material

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Youn Sin; Cho, June Sik; Youn, Wan Gyu; Ahn, Young Jun; Choi, Chang Lak; Lee, Young Hwan [Chungnam National Univ. College of Medicine, Taejon (Korea, Republic of)

    1996-07-01

    To evaluate the usefulness of dynamic spiral computed tomography(CT) during the portal phase with a higher IV injection rate of contrast material in detecting hepatic metastases. We reviewed two-phase dynamic spiral CT in 44 patients with hepatic metastases of pathologically proven primary malignancy. One hundred and fifty ml. of non-ionic contrast material was administered with a power injector at a rate of 5ml/sec., and two-phase images at 55-80 sec.(portal phase) and 2-5min. (equilibrium phase) were obtained after the start of bolus injection. Two phase images were compared for detectability of hepatic metastases according to size, number and enhancement pattern. In cases of metastases less than 1 cm, 113 lesions(100%) that showed clearly defined hypodense lesions were detected in the portal phase of dynamic CT. However, the equilibrium phase images showed hypodense lesions in 58 cases(51%) and isodense lesions in 55 cases(49%). In cases of metastases 1-2cm in size, the portal phase images detected 70 hypodense lesions(92%) and six hyperdense lesions(8%). In the equilibrium phase, however, the lesions were hypodense in 54 cases(71%), hyperdense in four(5%), and isodense in 18(24%). In cases of metastases larger than 2cm, portal phase images showed 29 hypodense lesions(97%) and one hyperdense lesion(3%). In the equilibrium phase, however, the lesions were hypodense in 25 cases(83%), hyperdense in two(7%), and mixed in three(10%). As compared with the portal phase, most metastatic lesions were detected as poorly defined hypodense or isodense lesions in the equilibrium phase and decrease in size due to peripheral enahncement. Dynamic spiral CT during the portal phase with a higher IV injection rate(5ml/sec) of contrast material is a useful method for detecting hepatic metastases, especially small lesions less than 1cm.

  9. Comparison of Image Registration Based Measures of Regional Lung Ventilation from Dynamic Spiral CT with Xe-CT

    CERN Document Server

    Ding, Kai; Fuld, Matthew K; Du, Kaifang; Christensen, Gary E; Hoffman, Eric A; Reinhardt, Joseph M

    2012-01-01

    Purpose: Regional lung volume change as a function of lung inflation serves as an index of parenchymal and airway status as well as an index of regional ventilation and can be used to detect pathologic changes over time. In this article, we propose a new regional measure of lung mechanics --- the specific air volume change by corrected Jacobian. Methods: 4DCT and Xe-CT data sets from four adult sheep are used in this study. Nonlinear, 3D image registration is applied to register an image acquired near end inspiration to an image acquired near end expiration. Approximately 200 annotated anatomical points are used as landmarks to evaluate registration accuracy. Three different registration-based measures of regional lung mechanics are derived and compared: the specific air volume change calculated from the Jacobian (SAJ); the specific air volume change calculated by the corrected Jacobian (SACJ); and the specific air volume change by intensity change (SAI). Results: After registration, the mean registration err...

  10. Spiral CT for evaluation of chest trauma; Spiral-CT beim Thoraxtrauma

    Energy Technology Data Exchange (ETDEWEB)

    Roehnert, W. [Universitaetsklinikum Dresden (Germany). Inst. und Poliklinik fuer Radiologische Diagnostik; Weise, R. [Universitaetsklinikum Dresden (Germany). Inst. und Poliklinik fuer Radiologische Diagnostik

    1997-07-01

    After implementation of spiral CT in our department, we carried out an analysis for determining anew the value of CT as a modality of chest trauma diagnosis in the emergency department. The retrospective study covers a period of 10 months and all emergency patients with chest trauma exmined by spiral CT. The major lesions of varying seriousness covered by this study are: pneumothorax, hematothorax, pulmonary contusion or laceration, mediastinal hematoma, rupture of a vessel, injury of the heart and pericardium. The various fractures are not included in this study. In many cases, spiral CT within relatively short time yields significant diagnostic findings, frequently saving additional angiography. A rigid diagnostic procedure cannot be formulated. Plain-film chest radiography still remains a diagnostic modality of high value. (Orig.) [Deutsch] Nach Einfuehrung der Spiral-CT in unserer Einrichtung versuchten wir, den Stellenwert der Computertomographie in der Notfalldiagnostik des Thoraxtraumas neu zu bestimmen. Dazu wurden retrospektiv ueber einen Zeitraum von 10 Monaten alle mittels Spiral-CT untersuchten Notfallpatienten mit Thoraxverletzungen ausgewertet. Im Vordergrund standen folgende Befunde unterschiedlichen Schweregrades: Pneumothorax, Haematothorax, Lungenkontusion/-lazeration, Mediastinalhaematom, Gefaessruptur, Herz- und Herzbeutelverletzung. Auf die unterschiedlichen Frakturen wird bewusst nicht naeher eingegangen. In vielen Faellen liefert die Spiral-CT mit relativ geringem Zeitaufwand wesentliche diagnostische Aussagen. Haeufig kann auf eine Angiographie verzichtet werden. Ein starres diagnostisches Stufenschema laesst sich nicht definieren. Die Thoraxuebersichtsaufnahme besitzt einen unveraendert hohen Stellenwert. (orig.)

  11. Assessment of spiral CT pneumocolon in preoperative colorectal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Can-Hui Sun; Zi-Ping Li; Quan-Fei Meng; Shen-Ping Yu; Da-Sheng Xu

    2005-01-01

    AIM: To investigate the value of spiral CT pneumocolon in preoperative colorectal carcinoma.METHODS: Spiral CT pneumocolon was performed prior to surgery in 64 patients with colorectal carcinoma. Spiral CT images were compared to specimens from the resected tumor.RESULTS: Spiral CT depicted the tumor in all patients.Comparison of spiral CT and histologic results showed that the sensitivity and specificity were 95.2%, 40.9% in detection of local invasion, and 75.0%, 90.9% in detection of lymph node metastasis. Compared to the Dukes classification,the disease was correctly staged as A in 6 of 18 patients,as B in 18 of 23, as C in 10 of 15, and as D in 7 of 8. Overall,spiral CT correctly staged 64.1% of patients.CONCLUSION: Spiral CT pneumocolon may be useful in the preoperative assessment of patients with colorectal carcinoma as a means for assisting surgical planning.

  12. Spiral CT venography in central venous obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jin Wook; Park, Jae Hyung; Im, Jung Gi; Han, Moon Hee; Kim, In One; Chang, Kee Hyun; Yeon, Kyung Mo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of); Song, Chi Sung [Boramae Hospital, Seoul (Korea, Republic of)

    1998-11-01

    To determine the clinical usefulness of spiral computed tomographic (CT) venography for the evaluation of central venous obstruction. The authors prospectively performed a total of 29 spiral CT venography procedures in 25 consecutive patients with suspected central venous obstrucion. Diluted contrast media were directly injected into the peripheral veins of the hand or the foot. Scan parameters were 3mm X-ray beam collimation, table speed of 4-6cm/sec, scan time of 32-40sec, and injection delay of 20 sec. Axial images were reconstructed at 2-mm intervals, and using shaded surface display(SSD), maximum intensity projection(MIP), and multiplanar reformation(MPR), 3-D reconstruction was performed. In all cases, ascending venograp-hy(n=3D13) and/or direct catheter venography (n=3D21) was performed within 2 days of CT venography. With regard to site, extent, extent, severity, and cause of obstruction and collateral circulation, we compared the results of CT and contrast venography. In 24 patients, a total of 56 sites of central venous obstruction or stenosis (>50%) were demonstrated. The causes of obstruction were venous thrombosis(n=3D6), malignant tumors(n=3D4), arteriovenous fistula for hemodialysis(n=3D5), extrinsic compression(n=3D2), coincidence of extrinsic compression and arteriovenous fistula(n=3D1), pacemaker(n=3D1), mediastinal inflammatory pseudotumor(n=3D1), spinal tuberculosis(n=3D1), membranous obstruction of the hepatic inferior vena cava(n=3D1), Behcet's disease(n=3D1), or unknown cause(n=3D1). When compared with ascending venography(n=3D13), CT venography was superior for evaluation of the extent and cause of obstruction and collateral circulation in two, four and one case(s), respectively. For the evaluation of site and severity of obstruction, CT venography was equal to ascending venography. In two cases, direct catheter venography (n=3D21) was superior to CT venography for evaluating the obstruction site, but in three, five and one case

  13. 螺旋 CT动态增强扫描在肺门肿瘤立体适形放射治疗中的价值%The value of spiral CT dynamically enhanced scanning in steric shape-fitting radiotherapy of hilar tumors

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To judge hilar tumors and their involvement range and improve the ability for the 3D plan of steric shape- fitting radiotherapy of pulmonary cancer dicide target area.Method Spiral CT dynamically enhanced scanning was used to localize the target area and distinguish pilar tumors,atelactasis,pilar blood vessels and enlarged lymphoid tissues,and define locus and involvement area.Result Local contour showed by spiral CT enhanced dynamically scanning was superior to that by common CT.Conclusion Spiral CT dynamically enhanced scanning is an ideal simulation for 3D conformal radiotherapy.

  14. Contrast enhanced two-phase spiral CT of urinary bladder

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeung Uk; Cha, Seong Sook; Ryu, Ji Hwa; Oh, Jeong Geun; Chang, Seung Kuk; Choi, Seok Jin; Eun, Choong Kie [Inje Univ. College of Medicine, Pusan (Korea, Republic of); Seo, Chang Hye [Daedong General Hospital, Pusan (Korea, Republic of)

    1997-10-01

    To determine optimal scan time for the early phase of two-phase spiral CT and to evaluate its usefulness in the detection and assessment of extension of urinary bladder lesions. In four normal adults, we performed dynamic scanning and obtained time-density curves for internal and external iliac arteries and veins, and the wall of the urinary bladder. Sixty patients with 68 lesions of the urinary bladder or prostate underwent precontrast and two-phase spiral CT scanning. After injection of 100ml of noninonic contrast material, images for the early and delayed phases were obtained at 60 seconds and 5 minutes, respectively. We measured CT H. U. of the wall, the lesion, and lumen of urinary bladder as seen on axial scanning, in each image in which the lesion was best shown. For the detection of bladder lesions and assessment of their extension, precontrast, early-, and delayed phsed images were compared. Dynamic study of normal adults showed maximum enhancement of bladder wall between 60 and 100 seconds. The difference of CT H. U. between bladder wall and the lesion was greatest in the early phase. The best detection rate(98.5%) was seen during this phase, and for the detection of bladder lesion, this same phase was superior or equal (66/68, 97.1%) to the delayed phase. The precontrast image was also superior or equal (31/68, 45.6%) to that of the delayed phase. For the assessment of extension of bladder lesion, the early phase was superior (36/68, 52.9%) to the delayed phase, and precontrast image was superiour (1/68, 1.5%) to that of the delayed phase. For determining the stage of bladder cancer, the early phase was most accurate if the stages was below B{sub 2} or D, while for stage C, the delayed phase was most accurate. In two-hpase spiral CT scanning, we consider the optimal time for the early phase to be between 60 and 100 seconds after injection of contrast material. For the detection and assessment of extension of urinary bladder lesion, the early phase was

  15. The role of multislice spiral CT in clinical cardiology

    Energy Technology Data Exchange (ETDEWEB)

    Haberl, R.; Boehme, E.; Richartz, B.; Czernik, A.; Buck, J.; Steinbigler, P. [Medical Hospital I and Department of Radiology, Klinik Muenchen-Pasing, Munich (Germany)

    2004-05-01

    Multislice spiral CT provides diagnostic-quality images of native coronary arteries and bypasses. Indications include prognosis in asymptomatic individuals, detection of significant coronary stenosis, and follow-up after interventions or surgery.

  16. Negative spiral CT in acute pulmonary embolism

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, T.; Olausson, A. [Karolinska Hospital, Stockholm (Sweden). Dept. of Thoracic Radiology; Johnsson, H. [Karolinska Hospital, Stockholm (Sweden). Dept. of Internal Medicine; Nyman, U. [County Hospital, Trelleborg (Sweden). Dept. of Radiology; Aspelin, P. [Huddinge Univ. Hospital (Sweden). Dept. of Radiology

    2002-09-01

    Purpose: To retrospectively evaluate the clinical outcome of non-anticoagulated patients with clinically suspected acute pulmonary embolism (PE) and no symptoms or signs of deep venous thrombosis (DVT) following a negative contrast medium-enhanced spiral CT of the pulmonary arteries (s-CTPA). Material and Methods: During a 24-month period, 739 of 751 patients underwent s-CTPA with acceptable diagnostic quality for clinically suspected acute PE. All patients who had a CT study not positive for PE were followed up with a questionnaire, a telephone interview and review of all medical reports, including autopsies and death certificates for any episodes of venous thromboembolism (VTE) during a 3-month period. Results: PE was diagnosed in 158 patients. Of the remaining 581 patients with a negative s-CTPA, 45 patients were lost to follow-up. 88 patients were excluded because of anticoagulation treatment (cardiac disorder n=32, chronic VTE or acute symptomatic DVT n=31, PE diagnosed at pulmonary angiography n=1, thrombus prophylaxis during diagnostic work-up or other reasons than VTE n=24) and 7 patients undergoing lower extremity venous studies because of symptoms of DVT (all negative). Thus, 441 patients with a negative s-CTPA and no DVT symptoms, venous studies or anticoagulant treatment constituted the follow-up cohort. Four of these patients had proven VTE (all PE) during the 3-month follow-up period. Two of the PE episodes contributed to the patient's death. Conclusion: Patients with clinically suspected acute PE, no symptoms or signs of DVT and a negative single slice s-CTPA using 3-5 mm collimation, may safely be left without anticoagulation treatment unless they are critically ill, have a limited cardiopulmonary reserve and/or if a high clinical suspicion remains.

  17. Pulmonary embolism findings on chest radiographs and multislice spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Coche, Emmanuel; Goncette, Louis [Department of Radiology, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Avenue Hippocrate 10, 1200, Brussels (Belgium); Verschuren, Franck [Department of Intensive Care and Emergency Medicine, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Avenue Hippocrate 10, 1200, Brussels (Belgium); Hainaut, Philippe [Department of Internal Medicine, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Avenue Hippocrate 10, 1200, Brussels (Belgium)

    2004-07-01

    Multislice spiral CT is becoming an increasingly important tool for diagnosing pulmonary embolism. However, in many instances, a chest radiograph is usually performed as a first-line examination. Many parenchymal, vascular, and other ancillary findings may be observed on both imaging modalities with a highly detailed depiction of abnormalities on multislice CT. A comprehensive review of chest radiograph findings is presented with side-by-side correlations of CT images reformatted mainly in the frontal plane. (orig.)

  18. Pulmonary embolism findings on chest radiographs and multislice spiral CT.

    Science.gov (United States)

    Coche, Emmanuel; Verschuren, Franck; Hainaut, Philippe; Goncette, Louis

    2004-07-01

    Multislice spiral CT is becoming an increasingly important tool for diagnosing pulmonary embolism. However, in many instances, a chest radiograph is usually performed as a first-line examination. Many parenchymal, vascular, and other ancillary findings may be observed on both imaging modalities with a highly detailed depiction of abnormalities on multislice CT. A comprehensive review of chest radiograph findings is presented with side-by-side correlations of CT images reformatted mainly in the frontal plane.

  19. Multislice spiral CT of the paranasal sinuses; Mehrschicht-Spiral-CT der Nasennebenhoehlen: Erste Erfahrungen unter besonderer Beruecksichtigung der Strahlenexposition

    Energy Technology Data Exchange (ETDEWEB)

    Dammann, F.; Bode, A.; Heuschmid, M.; Kopp, A.; Georg, C.; Pereira, P.L.; Claussen, C.D. [Tuebingen Univ. (Germany). Radiologische Universitaetsklinik

    2000-08-01

    Purpose: To evaluate the potential of multislice CT in the diagnosis of the paranasal sinuses. Methods: Dose measurements were performed exposing an Alderson Rando phantom in a four-slice spiral CT (MS-CT) while applying a variety of scan parameters. Additionally, 30 consecutive patients underwent a transversal examination by the MS-CT using 1/1/3.5/0.5 mm spiral parameters and an additional transversal or coronal scan on a conventional single slice spiral CT (SS-CT) with 2/3/1 mm. Coronal reformations of the MS-CT were compared with the primary coronal SS-CT, or coronal reformations of the transversal SS-CT, respectively, with regard to image quality and depiction of relevant anatomical details of the region. Results: Superficial exposure values at the level of the eye lenses as well as for the thyroid gland were superior for MS-CT (3.62 mGy, and 0.12 mGy, resp.) as compared to SS-CT (2.96 mGy, and 0.07 mGy). Image quality was equal or superior for MS-CT as compared to SS-CT in all but one case. Drawbacks of SS-CT, such as dental amalgam artifacts, stair step artifacts or partial volume artifacts did not notably affect the coronal reformations of MS-CT. Conclusions: MS-CT seems to have the potential to replace primary coronal CT of the paranasal sinuses without any loss of image quality, but may even improve the overall diagnostic value. Radiation doses may still have to be reduced. (orig.) [German] Ziel: Erprobung eines Multislice-CT (MS-CT) zur Diagnostik der Nasennebenhoehlen (NNH). Methode: An einem Alderson Rando Phantom wurden Dosismessungen bei der Spiral-CT der NNH mit einem Mehrschicht-CT (MS-CT) unter Verwendung unterschiedlicher Scanparameter durchgefuehrt. Anschliessend wurden 30 konsekutive Patienten an dem MS-CT mit den Spiralparametern 1/1/3,5/0,5 mm und einem konventionellen Einzeilen Spiral-CT (SS-CT; 2/3/1 mm) untersucht. Die koronaren Rekonstruktionen der transversalen MS-CT wurden mit den koronaren Rekonstruktionen bzw. den primaeren koronaren

  20. Design Consideration and Reconstruction Method for Double-source Double-multislice Spiral CT

    Institute of Scientific and Technical Information of China (English)

    LIU Zun-gang; ZHAO Jun; ZHUANG Tian-ge

    2007-01-01

    To accelerate the scan speed and improve the image quality, a new type of CT configuration, "doublesource double-multislice spiral CT" (DSDMS-CT), which is based on two sets of single-source multislice spiral CT was proposed with a special reconstruction algorithm.Simulation results using the fan-beam filtered backprojection algorithm with a special interpolation method were presented for both single-source multislice spiral CT and DSDMS-CT.The results of new CT model show that it scans faster than the traditional spiral CT and has a better slice sensitivity profile (SSP) with larger pitch value.

  1. Spiral CT colonography in inflammatory bowel disease

    Energy Technology Data Exchange (ETDEWEB)

    Tarjan, Zsolt E-mail: tarjan@radi.sote.hu; Zagoni, Tamas; Gyoerke, Tamas; Mester, Adam; Karlinger, Kinga; Mako, Erno K

    2000-09-01

    Objective: Most of the studies on virtual colonoscopy are dealing with the role of detecting colorectal polyps or neoplasms. We have undertaken this study to evaluate the value of CT colonography in patients with colonic Crohn's disease. Methods and material: Five patients (three males, two females, 23-51 years, mean age 42 years) with known (4) or suspected (1) Crohn's disease of the colon underwent fiberoptic colonoscopy and CT colonography in the same day or during a 1-week period. The images were evaluated with the so called zoomed axial slice movie technique and in some regions intra- and extraluminal surface shaded and volume rendered images were generated on a separate workstation. The results were compared to those of a colonoscopy. Results: The final diagnosis was Crohn's disease in four patients and colitis ulcerosa in one. Total examination was possible by colonoscopy in two cases, and with CT colonography in all five cases. The wall of those segments severely affected by the disease were depicted by the axial CT scans to be thickened. The thick walled, segments with narrow lumen seen on CT colonography corresponded to the regions where colonoscopy was failed to pass. Air filled sinus tracts, thickening of the wall of the terminal ileum, loss of haustration pseudopolyps and deep ulcers were seen in CT colonography. Three dimensional (3D) endoluminal views demonstrated pseudopolyps similar to endoscopic images None of the colonoscopically reported shallow ulcerations or aphtoid ulcerations or granular mucosal surface were observed on 2- or 3D CT colonographic images. Conclusion: CT colonography by depicting colonic wall thickening seems to be a useful tool in the diagnosis of Crohn's colitis, which could be a single examination depicting the intraluminal, and transmural extent of the disease.

  2. Spiral CT pneumocolon: applications, status and limitations.

    Science.gov (United States)

    Harvey, C J; Renfrew, I; Taylor, S; Gillams, A R; Lees, W R

    2001-01-01

    CT pneumocolon is a promising new technique in the diagnosis and management of colon pathology. CT pneumocolon can detect (sensitivity >95%) and stage (accuracy 79%) colorectal cancer and is very accurate in the differentiation of malignant from benign colonic pathologies. It has excellent detection rates for polyps >10 mm in diameter. Several studies using 3D virtual colonoscopy have already proven its high sensitivity and specificity in polyp detection making this technique robust as a screening tool. The combined results for virtual colonoscopy, from all centres, show a sensitivity of >85% in the detection of polyps 10 mm or greater in size, 70-80% for 5-9 mm polyps and an overall specificity of 90%. CT pneumocolon is a safe, non-invasive and cost-effective method for detecting colonic carcinomas and adenomas and correctly identifying which patients need further colonoscopy. The technique is quick, well tolerated and non-operator dependent. It can also image the proximal colon when distal stenoses prevent endoscopic and barium examination. CT pneumocolon is able to identify the features and complications of inflammatory bowel disease. Further research is warranted to fully assess its impact in terms of a screening tool, acceptability, availability and cost benefit.

  3. Spiral CT pneumocolon: applications, status and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, C.J. [Department of Academic Imaging, University College London (United Kingdom); Department of Imaging, Hammersmith Hospital, London (United Kingdom); Renfrew, I.; Taylor, S.; Gillams, A.R.; Lees, W.R. [Department of Academic Imaging, University College London (United Kingdom)

    2001-09-01

    CT pneumocolon is a promising new technique in the diagnosis and management of colon pathology. CT pneumocolon can detect (sensitivity >95%) and stage (accuracy 79%) colorectal cancer and is very accurate in the differentiation of malignant from benign colonic pathologies. It has excellent detection rates for polyps >10 mm in diameter. Several studies using 3D virtual colonoscopy have already proven its high sensitivity and specificity in polyp detection making this technique robust as a screening tool. The combined results for virtual colonoscopy, from all centres, show a sensitivity of >85% in the detection of polyps 10 mm or greater in size, 70-80% for 5-9 mm polyps and an overall specificity of 90%. CT pneumocolon is a safe, non-invasive and cost-effective method for detecting colonic carcinomas and adenomas and correctly identifying which patients need further colonoscopy. The technique is quick, well tolerated and non-operator dependent. It can also image the proximal colon when distal stenoses prevent endoscopic and barium examination. CT pneumocolon is able to identify the features and complications of inflammatory bowel disease. Further research is warranted to fully assess its impact in terms of a screening tool, acceptability, availability and cost benefit. (orig.)

  4. Anatomy of the bronchial arteries: imaging via spiral CT. Anatomie der Bronchialarterien - Darstellung mit der Spiral-CT

    Energy Technology Data Exchange (ETDEWEB)

    Schwickert, H.C. (Universitaetskliniken, Mainz (Germany). Klinik mit Poliklinik fuer Radiologie); Kauczor, H.U. (Universitaetskliniken, Mainz (Germany). Klinik mit Poliklinik fuer Radiologie); Schweden, F. (Universitaetskliniken, Mainz (Germany). Klinik mit Poliklinik fuer Radiologie); Schild, H.H. (Universitaetskliniken, Mainz (Germany). Klinik mit Poliklinik fuer Radiologie)

    1994-06-01

    The purpose of our study was to evaluate the capability of spiral CT in detecting bronchial arteries and in classifying their anatomic variations. Patients and Methods: In 43 patients with different diseases routine spiral CTs of the chest were performed and evaluated retrospectively. Spiral CT was started with a delay of 30 seconds after contrast material application. Results: In 43 patients a total of 67 bronchial arteries were detected: 31 right, 35 left and one common trunk. 26 right bronchial arteries originated medially, 5 anteriorly from the descending aorta, 7 of them together with an intercostal artery. 25 right bronchial arteries passed dorsally, 6 ventrally to the oesophagus. On the left, all 35 bronchial arteries originated from the anterior aorta: 12 led ventrally through the aorticopulmonary window to the ventral wall of the main bronchus, 14 were directed caudally to the cranial and 9 laterally to the posterior aspect of the main bronchus. The discernible length varied between 15 and 90 mm on the right, and between 10 and 37 mm on the left side. Only in two cases did the proximal diameter measure more than 2 mm. Conclusion: Spiral CT offers the possibility to classify the anatomic course and pathologic changes of the bronchial arteries. (orig.)

  5. Multidetector spiral CT arthrography of the shoulder

    Energy Technology Data Exchange (ETDEWEB)

    Lecouvet, Frederic E. [Departments of Radiology and Orthopaedic Surgery, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Hippocrate Avenue 10/2942, 1200 Brussels (Belgium)], E-mail: frederic.lecouvet@uclouvain.be; Simoni, Paolo; Koutaissoff, Sophie; Vande Berg, Bruno C.; Malghem, Jacques; Dubuc, Jean-Emile [Departments of Radiology and Orthopaedic Surgery, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Hippocrate Avenue 10/2942, 1200 Brussels (Belgium)

    2008-10-15

    Although MR imaging and MR arthrography are the first choice modalities for shoulder imaging, CT arthrography (CTA) may be used successfully to address many clinical questions. The advent of submillimeter multiple detector CT technology and subsequent excellent three-plane resolution has considerably increased the quality of CTA examinations and has propelled this technique to the forefront in a growing number of indications. The combined use of iodinated contrast material for fluoroscopic confirmation of the articular position of the needle before injection of gadolinium chelates for MR arthrography offers the unique opportunity to compare CTA and MRA findings in carefully selected cases. This paper illustrates capabilities and limits of CTA for the study of rotator cuff tears, shoulder instability, cartilage lesions, anatomical variants and abnormalities of the glenoid labrum, with correlations to MR arthrography and surgical findings.

  6. 3D Reconstruction in Spiral Multislice CT Scans

    Directory of Open Access Journals (Sweden)

    M. Ghafouri

    2005-08-01

    Full Text Available Introduction & Background: The rapid development of spiral (helical computed tomography (CT has resulted in exciting new applications for CT. One of these applications, three-dimensional (3D CT with volume ren-dering, is now a major area of clinical and academic interest. One of the greatest advantages of spiral CT with 3D volume rendering is that it provides all the necessary information in a single radiologic study (and there-fore at the lowest possible price in cases that previously required two or more studies. Three-dimensional vol-ume rendering generates clinically accurate and immediately available images from the full CT data set with-out extensive editing. It allows the radiologist and clinician to address specific questions concerning patient care by interactively exploring different aspects of the data set. Three-dimensional images integrate a series of axial CT sections into a form that is often easier to interpret than the sections themselves and can be made to appear similar to other more familiar images such as catheter angiograms. The data are organized into a 3D matrix of volume elements (voxels. The screen of the computer monitor is a 2D-surface composed of discrete picture elements (pixels. Presenting what is stored in memory (ie, floating within the monitor on a 2D-screen is a challenge, but it is the very problem that 3D reconstruc-tion software has creatively solved. Voxel selection is usually accomplished by projecting lines (rays through the data set that correspond to the pixel matrix of the desired 2D image. Differences in the images produced with various 3D rendering techniques are the result of variations in how voxels are selected and weighted. In this article, I compare 3D volume rendering of spiral CT data with other rendering techniques (shaded surface display, maximum intensity projection and present a brief history of 3D volume rendering and discuss the im-plementation of this promising technology in terms of

  7. Three-dimensional spiral CT for neurosurgical planning

    Energy Technology Data Exchange (ETDEWEB)

    Klein, H.M. (Dept. of Neurosurgery, Technical Univ., Aachen (Germany)); Bertalanffy, H. (Dept. of Neurosurgery, Technical Univ., Aachen (Germany)); Mayfrank, L. (Dept. of Neurosurgery, Technical Univ., Aachen (Germany)); Thron, A. (Dept. of Neuroradiology, Technical Univ., Aachen (Germany)); Guenther, R.W. (Dept. of Diagnostic Radiology, Technical Univ., Aachen (Germany)); Gilsbach, J.M. (Dept. of Neurosurgery, Technical Univ., Aachen (Germany))

    1994-08-01

    We carried out 22 examinations to determine the value of three-dimensional (3D) volumetric CT (spiral CT) for planning neurosurgical procedures. All examinations were carried out on a of the first generation spiral CT. A tube model was used to investigate the influence of different parameter settings. Bolus injection of nonionic contrast medium was used when vessels or strongly enhancing tumours were to be delineated. 3D reconstructions were carried out using the integrated 3D software of the scanner. We found a table feed of 3 mm/s with a slice thickness of 2 mm and an increment of 1 mm to be suitable for most purposes. For larger regions of interest a table feed of 5 mm was the maximum which could be used without blurring of the 3D images. Particular advantages of 3D reconstructed spiral scanning were seen in the planning of approaches to the lower clivus, acquired or congenital bony abnormalities and when the relationship between vessels, tumour and bone was important. (orig.)

  8. Demonstration of pulmonary embolism with gadolinium-enhanced spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Coche, E.E.; Hammer, F.D.; Goffette, P.P. [Dept. of Radiology, St. Luc University Hospital, Brussels (Belgium)

    2001-11-01

    The authors report a case of successful detection of pulmonary embolism using gadolinium-enhanced spiral CT (Gadodiamide, 0.4 mmol/kg, 2 ml/s, delay 18 s) in a 77-year-old woman, with previous allergy to iodinated contrast medium, and renal failure, who presented with pulmonary arterial hypertension. Doppler ultrasound of the lower limbs was first performed and revealed a deep venous thrombosis of the right lower limb. To establish if venous thrombosis was the cause of pulmonary hypertension and to confirm that pulmonary endarterectomy was not indicated in this situation, several imaging modalities were performed. Lung scintigraphy and MRI were non-diagnostic. Gadolinium-enhanced spiral CT demonstrated a large thrombus located proximally and in a segmental artery of the right lower lobe. This case illustrates the potential usefulness of gadolinium as alternative contrast agent with spiral CT to diagnose pulmonary embolism and elucidate the cause of pulmonary arterial hypertension in a patient with some contraindications for iodinated contrast medium injection. (orig.)

  9. Abdominal wall hernias: imaging with spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Stabile Ianora, A.A.; Midiri, M.; Vinci, R.; Rotondo, A.; Angelelli, G. [Department of Radiology, Bari University Hospital (Italy)

    2000-06-01

    Computed tomography is an accurate method of identifying the various types of abdominal wall hernias, especially if they are clinically occult, and of distinguishing them from other diseases such as hematomas, abscesses and neoplasia. In this study we examined the CT images of 94 patients affected by abdominal wall hernias observed over a period of 6 years. Computed tomography clearly demonstrates the anatomical site of the hernial sac, the content and any occlusive bowel complications due to incarceration or strangulation. Clinical diagnosis of external hernias is particularly difficult in obese patients or in those with laparotic scars. In these cases abdominal imaging is essential for a correct preoperative diagnosis and to determine the most effective treatment. (orig.)

  10. Acute cholecystitis: two-phase spiral CT finding

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Eung Young; Yoon, Myung Hwan; Yang, Dal Mo; Chun Seok; Bae, Jun Gi; Kim, Hak Soo; Kim, Hyung Sik [Chungang Ghil Hospital, Incheon (Korea, Republic of)

    1998-07-01

    To describe the two-phase spiral CT findings of acute cholecystitis. Materials and Methods : CT scans of nine patients with surgically-proven acute cholecystitis were retrospectively reviewed for wall thickening, enhancement pattern of the wall, attenuation of the liver adjacent to the gallbladder, gallstones,gallbladder distension, gas collection within the gallbladder, pericholecystic fluid and infiltration of pericholecystic fat. Results : In all cases, wall thickening of the gallbladder was seen, though this was more distinct on delayed images, Using high-low-high attenuation, one layer was seen in five cases, nd three layers in four. On arterial images, eight cases showed transient focal increased attenuation of the liver adjacent to the gall bladder;four of these showed curvilinear attenuation and four showed subsegmental attenuation. One case showed curvilinear decreased attenuation between increased attenuation of the liver and the gallbladder, and during surgery, severe adhesion between the liver and gallbladder was confirmed. Additional CT findings were infiltration of pericholecystic fat (n=9), gallstones (n=7), gallbladder distension (n=6), pericholecystic fluid(n=3), and gas collection within the gallbladder (n=2). Conclusion : In patients with acute cholecystitis,two-phase spiral CT revealed wall thickening in one or three layers ; on delayed images this was more distinct. In many cases, arterial images showed transient focal increased attenuation of the liver adjacent to the gallbladder.

  11. Three-dimensional spiral CT of craniofacial malformations in children

    Energy Technology Data Exchange (ETDEWEB)

    Binaghi, S. [Payerne Hopital, Lausanne (Switzerland). Dept. of Radiology; Service de Radiodiagnostic et Radiologie Interventionnelle, Lausanne (Switzerland); Gudinchet, F. [Payerne Hopital, Lausanne (Switzerland). Dept. of Radiology; Rilliet, B. [Dept. of Neurosurgery, University Hospital of Lausanne (Switzerland)

    2000-12-01

    Objective. To assess the value of three-dimensional CT (3D CT) in the diagnosis and management of suspected paediatric craniofacial malformations. Materials and methods. Twenty-eight children (12 girls, 16 boys) with a mean age of 4 years, suffering from craniofacial or cervical malformations, underwent craniofacial spiral CT. 3D reformatting was performed using an independent workstation. Results. 3D CT allowed the preoperative evaluation of 16 patients with craniosynostosis and the post-surgical management of 2 patients. 3D CT clearly depicted malformations of the skull base involving the petrous bone in seven patients (four cases of Goldenhar-Gorlin syndrome, one case of Treacher-Collins syndrome and two cases of Crouzon's disease). Four patients with craniofacial clefts were also evaluated. Radiological findings were confirmed by the clinical and intraoperative findings in all patients that underwent surgical treatment. Movement artefacts and ''Lego effect'' related to abrupt change of cranial vault border were encountered and are discussed. Conclusions. 3D CT of the skull can safely and reliably identify paediatric craniofacial malformations involving bone, and it should be used as morphological mapping to help the surgeon in planning surgical treatment. (orig.)

  12. Pulmonary embolism: spiral CT evaluation; Embolie pulmonaire: apport de la tomodensitometrie helicoidale

    Energy Technology Data Exchange (ETDEWEB)

    Senac, J.P.; Vernhet, H.; Bousquet, C.; Giron, J.; Pieuchot, P.; Durand, G.; Benezet, O.; Aubas, P. [Centre Hospitalier Universitaire, 34 - Montpellier (France)

    1995-06-01

    Purpose: Spiral computed tomography was compared retrospectively with digital substraction pulmonary angiography (PA) in 45 patients suspected of having acute or chronic pulmonary embolism. Materials and method : 45 patients in whom the presence of acute or chronic pulmonary embolism was suspected underwent examination by spiral CT and PA. Diagnosis of pulmonary embolism was based on the direct visualization of intraluminal clots. The study of the agreement between the two methods was based on the Kappa test. In 35 cases, pulmonary emboli were proved. Acute pulmonary emboli were present in 28 cases and chronic in 7 cases. Results: Spiral computed tomography represents an excellent way to detect acute pulmonary embolism. In the chronic form, spiral CT is better than PA to detect intraluminal clots. However, Spiral CT can fail to detect small emboli in the peripheral arterial bed. In the 10 patients without pulmonary embolism, the spiral CT proved diagnosis pulmonary oedema (n=3), lymphangi-carcinoma (n=4), pleural effusion (n=3). Conclusion: This study suggest that the spiral CT examination is accurate for diagnosis of pulmonary embolism specifically in case of suspected important embolism. The advantages of spiral CT are multiple (non invasive, wide diagnosis spectrum). However, may be a limitation to is use is insufficient distal thrombi detection. This eventuality (5 to 10% in the Pioped study) justify the practice of pulmonary angiography. Spiral CT improvements should reduce this insufficiency in the next future. (Authors). 16 refs., 4 figs., 3 tabs.

  13. Nodular hepatocellular carcinoma : contrast enhancement patterns on three - phase spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hak Jong; Choi, Byung Ihn; Han, Joon Koo; Kim, Seung Hyup; Kim, Woo Sun; Kim, Tae Kyung; Choi, Dae Seop [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-09-01

    To evaluate contrast enhancement patterns of nodular hepatocellular carcinomas (HCCs) on three-phase spiral CT. A retrospective analysis of contrast enhancement patterns was performed in 48 patients with HCC. Three-phase dynamic CT images of hepatic arterial dominant phase, portal dominant phase, and delayed phase were obtained at 30, 65 and 360 seconds after the initiation of injection of contrast material, respectively. Iodized-oil CT was performed two weeks after angiography and infusion of iodized-oil. Masses were divided into three groups, according to size ; 1-20mm (n=34), 21-40mm (n=26), and over 40mm (n=19). Contrast enhancement patterns of tumors compared with attenuation of surrounding liver parenchyma, were cheracterized as one of four types, as follows : high, iso, low and mixed attenuation. Seventy-three of 79 HCC nodules detected on iodized-oil CT (92%) were detected on three-phase spiral CT. In the 1-20mm group, masses showed high-attenuation in the arterial dominant phase(19/34, 55.9%), and iso-attenuation in the portal dominant phase(16/34, 47.1 %) and delayed phase(18/34, 52.9%). In the 21-40mm group, masses showed high-attenuation in the arterial dominant phase(21/26, 80.8 %), low-attenuation in the portal dominant phase(13/26, 50%) and delayed phase(21/26, 80.8 %). In the over 40m group, the masses showed mixed-attenuation in the arterial dominant phase(9/19, 47.4%), low-attenuation in the portal dominant phase(12/19, 63.2%), and delayed phase(16/19, 84.2 %). The most common enhancement pattern was high(arterial dominant)-iso(portal dominant)-iso(delayed) in the 1-20 mm group (8/34, 23.5 %), high-low-low in the group 21-40 mm (8/26, 30.8%), and mixed-low-low in the over 40mm group (5/19, 26.3%). Hepatocellular carcinomas showed variable enhancing patterns according to the size of the tumor on three-phase spiral CT. Understanding these enhancing characteristics of HCCs on three-phase spiral CT may be helpful in their diagnosis.

  14. Helical CT defecography; La defecografia con Tomografia Computerizzata spirale

    Energy Technology Data Exchange (ETDEWEB)

    Ferrando, R.; Fiorini, G.; Beghello, A.; Cicio, G.R.; Derchi, L.E.; Consigliere, M.; Resasco, M. [Genua Univ., Genua (Italy). Ist. di Radiologia, Cattedra R; Tornago, S. [Genua Univ. Genua (Italy). 2 Clinica Ortopedica

    1999-11-01

    The purpose of this work is to investigate the possible role of Helical CT defecography in pelvic floor disorders by comparing the results of the investigations with those of conventional defecography. The series analyzed consisted of 90 patients, namely 62 women and 28 men, ranging in age 24-82 years. They were all submitted to conventional defecography, and 18 questionable cases were also studied with Helical CT defecography. The conventional examination was performed during the 4 standard phases of resting, squeezing, Valsalva and straining; it is used a remote-control unit. The parameters for Helical CT defecography were: 5 mm beam collimation, pitch 2, 120 KV, 250 m As and 18-20 degrees gantry inclination to acquire coronal images of the pelvic floor. The rectal ampulla was distended with a bolus of 300 mL nonionic iodinated contrast agent (dilution: 3g/cc). The patient wore a napkin and was seated on the table, except for those who could not hold the position and were thus examined supine. Twenty-second helical scans were performed at rest and during evacuation; multiplanar reconstructions were obtained especially on the sagittal plane for comparison with conventional defecographic images. Coronal Helical CT defecography images permitted to map the perineal floor muscles, while sagittal reconstructions provided information on the ampulla and the levator ani. To conclude, Helical CT defecography performed well in study of pelvic floor disorders and can follow conventional defecography especially in questionable cases. [Italian] Scopo di questo lavoro e' ricercare un ruolo per la defeco-TC con apparecchiatura elicoidale nello studio delle malattie del pavimento pelvico confrontandola con i risultati consolidati della defecografia tradizionale. Si sono visionati 90 pazienti, 62 femmine e 28 maschi, con eta' compresa tra 24 e 82 anni, con defecografia tradizionale; di questi, 18 casi con diagnosi dubbia sono stati studiati anche con defeco-TC spirale

  15. Spiral orbits and oscillations in historical dynamics

    CERN Document Server

    Cheon, Taksu

    2015-01-01

    We introduce the concept of metaasabiya, the second non-material resource, to the asabiya theory of historical dynamics. We find that the resulting three variable dynamical system has peculiar features such as repelling or attracting axes and spiralling orbits in the phase space. Depending on the initial state, the system can go through series of oscillatory rises and falls, mimicking the geopolitical evolution of real-world polities. These distinctive features, absent in conventional Lotka-Volterra type biological systems, reveal the hidden richness inherent in the asabiya theory.

  16. Multi-slice spiral CT three-dimensional imaging and perfusion imaging in acute brain injury of dynamic application%多层螺旋CT三维图像重建和脑灌注成像在急性颅脑损伤动态变化中应用

    Institute of Scientific and Technical Information of China (English)

    杨小秦; 柳少光; 王治民; 王学斌; 张可; 魏晓东; 张冬志

    2012-01-01

    Objective Discussion of ultrathin multilayer spiral CT 3D image reconstruction,skull and brain perfusion imaging in acute brain injury to dynamic changes in the clinical value.Methods 2009December to 2011 October were collected in our hospital in 245 patients with acute traumatic brain injury patients check information,both in the 3-6 h after injury within conventional multislice spiral CT,thin multilayer spiral CT and three-dimensional image reconstruction of skull and brain CT perfusion imaging examination,all the cases in 2 to 7 days after injury dynamic review of conventional MSCT and ultrathin multilayer spiral CT,the data were retrospectively analyzed,using the chi-squared test evaluation.Results Super thin multilayer spiral CT in cerebral contusion and laceration,intracerebral hematoma in TBI with mixed diagnosis has statistics difference is better than the conventional MSCT.CTP in acute traumatic brain injury diagnosis was superior to conventional MSCT except diffuse axonal injury.CTP in cerebral contusion and laceration,subdural hematoma and intracerebral hematoma associated with intracerebral hematoma in the diagnosis with statistical difference,better than the ultrathin multilayer spiral CT (P < 0.05).The 3D image reconstruction of skull fracture demonstrated great advantages in the treatment of skull fracture,which include cranial suture separation and basal skull fracture.Conclusion combined Super thin multilayer spiral CT 3D image reconstruction skull and brain CT perfusion imaging for acute craniocerebral injury early diagnosis and minimal injury diagnosis is superior to conventional multislice spiral CT,The rate of misdiagnosis can be decreased.which provide Reliable basis for early diagnosis and Prognosis of TBI.%目的 探讨超薄多层螺旋CT、颅骨三维图像重建和脑灌注成像在急性颅脑外伤动态变化中的临床应用价值.方法 收集2009年12月至2011年10月我院收治的245例急性颅脑外

  17. Reconstruction of the portal vein with 64-slice spiral CT of bile duct obstruction

    OpenAIRE

    Xia, Yunbao; PAN, GONGMAO; Xue, Feng; Geng, Chengjun

    2013-01-01

    The aim of this study was to evaluate 64-slice spiral CT image reconstruction of the portal vein in biliary obstruction. A total of 34 clinical patients with biliary obstruction were confirmed by 64-slice spiral CT scanning with portal venous phase multi-planar reconstruction (MPR) of the biliary tract, curved planar reconstruction (CPR), thin-slab minimum-intensity projection (TS-MinIP) and maximum intensity projection (MIP). The reconstructed images were reviewed to further assess the posit...

  18. Spiral Wave Dynamics in a Response System Subjected to a Spiral Wave Forcing

    Institute of Scientific and Technical Information of China (English)

    LI Guang-Zhao; CHEN Yong-Qi; TANG Guo-Ning; LIU Jun-Xian

    2011-01-01

    @@ Unidirectional linear error feedback coupling of two excitable medium systems displaying spiral waves is considered.The spiral wave in the response system is thus subjected to a spiral wave forcing.We find that the unidirectional feedback coupling can lead to richer behaviour than the mutual coupling.The spiral wave dynamics in the response system depends on the coupling strength and frequency mismatch.When the coupling strength is small, the feedback coupling induces the drift or meander of the forced spiral wave.When the coupling strength is large enough, the feedback coupling may lead to the transition from spiral wave to anti-target or target-like wave.The generation of anti-target wave in coupled excitable media is observed for the first time.Furthermore, when the coupling strength is strong, the synchronization between two subsystems can be established.%Unidirectional linear error feedback coupling of two excitable medium systems displaying spiral waves is considered. The spiral wave in the response system is thus subjected to a spiral wave forcing. We find that the unidirectional feedback coupling can lead to richer behaviour than the mutual coupling. The spiral wave dynamics in the response system depends on the coupling strength and frequency mismatch. When the coupling strength is small, the feedback coupling induces the drift or meander of the forced spiral wave. When the coupling strength is large enough, the feedback coupling may lead to the transition from spiral wave to anti-target or target-like wave. The generation of anti-target wave in coupled excitable media is observed for the first time. Furthermore,when the coupling strength is strong, the synchronization between two subsystems can be established.

  19. Spiral CT angiography of renal arteries: comparison with angiography

    Energy Technology Data Exchange (ETDEWEB)

    Wittenberg, G.; Kenn, W.; Tschammler, A.; Sandstede, J.; Hahn, D. [Inst. fuer Roentgendiagnostik der Universitaet Wuerzburg (Germany)

    1999-04-01

    A prospective study was carried out to determine the accuracy of spiral CT angiography (CTA) in the detection of renal artery stenosis (RAS). Eighty-two patients with arterial hypertension underwent CTA and digital subtraction angiography (DSA) to exclude RAS. For CTA a contrast medium bolus of 100-150 ml (flow rate 3 ml/s) was injected. A 24 or 40 s CTA was started at the origin of the superior mesenteric artery after a delay time determined by test bolus injection (collimation = 2 mm, pitch = 1/1.5). For stenosis detection transverse images supported by maximum intensity projections (MIP) or multiplanar reconstruction projections were used. Of 197 renal arteries examined (including 33 accessory arteries), 34 RAS were visualized using DSA. With CTA, one hemodynamic RAS was missed and one additional hemodynamic RAS was found. Sensitivity/specificity was calculated to be 94 %/98 %. For hemodynamically relevant RAS (> 50 %) the sensitivity/specificity was 96 %/99 %. CTA additionally depicted five adrenal masses. The high accuracy rate of RAS detection thus allows the use of CTA as a screening method in patients with arterial hypertension to exclude a renovascular cause. (orig.) With 2 figs., 1 tab., 25 refs.

  20. Application of 64 slice spiral CT in evaluating the patency of coronary artery after stent implantation

    Institute of Scientific and Technical Information of China (English)

    Yong-Shu Gao; Xing-Can Ma

    2015-01-01

    Objective:To explore the feasibility and effectiveness of 64 slice spiral CT in evaluating the patency of coronary artery after stent implantation.Methods:The 64 slice spiral CT image data of 125 patients after coronary artery stent implantation were collected, meanwhile, the image data of 25 patients underwent coronary angiography were also collected. The feasibility and accuracy of 64 slice spiral CT coronary artery stent imaging were comparatively analyzed. Results: The 64 slice spiral CT imaging quality with a stent diameter greater than 3.00 mm was significantly superior to that with a diameter of 2.25-3.00 mm. The CT imaging quality in the left main coronary artery and anterior descending artery was significantly higher than that in the left circumflex coronary artery. The CT imaging quality in the left main coronary artery was significantly higher than that in the right coronary artery. The CT reconstruction imaging quality in the drug coating stent was significantly superior to that in the bare metal stent. The sensitivity of 64 slice spiral CT was 100.00%, and the accuracy was 100.00%. In detecting the coronary artery with occlusion and stenosis (stent stenosis greater than 50%), the sensitivity was 90.00%, the false negative rate was 10.00%, and the positive predicative value was 100.00%.Conclusions:The effect of 64 slice spiral CT coronary imaging in evaluating the patency of coronary artery after stent implantation is highly consistent with that by coronary angiography, with a simple operation, less risk, and low cost, and thus, it can be completely taken as the imaging method in evaluating the patency of coronary artery after stent implantation.

  1. Measurement of total lung capacity : a comparison of spiral CT and spirometry

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Kyung Il; Park, Kyung Ju; Lee, Eh Hyung; Yune, Heun Young; Suh, Jung Ho [Ajou Univ. School of Medicine, Suwon (Korea, Republic of); Choe, Kyu Ok; Lim, Tae Hwan [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of); Chung, In Hyuk [Ulsan Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-08-01

    To determine the potential of spiral CT as a functional imaging modality of the lung aside from its proven value in morphological depiction. Spiral CT scan was performed in ten normal female and nine normal male adults (mean age: 39, height: 163 cm, weight: 62 kg ) after single full breath-holding. Three dimensional lung images were reconstructed(minimal threshold value: -1,000HU, maximal threshold values: -150, 250, -350, -450 HU) to obtain total lung volume(TLV) on a histogram. Total lung volume measured by spiral CT was compared with TLV obtained by spirometry. Mean TLV measured by spirometry was 5.62L and TLV measured by CT at maximal threshold values of -150, -250, -350, and -450 HU was 5.53, 5.33, 5.15, and 4.98L, respectively. Mean absolute differences between the modalities of 0.17L(3%), 0.32L(5.6%), 0.48L(8.5%), 0.65L(11.5%) were statistically significant(p<0.001). Linear regression coefficients between the modalities were 0.99, 0.97, 095, and 0.94 and no statistically significant differences in accuracy of threshold levels in the estimation of lung volume(r=0.99, standard error=0.034L in all) were seen. TLV measured by spiral CT closely approximated that measured by spirometry. Spiral CT may be useful as a means of evaluating lung function.

  2. Diagnostic Value of 16 Slices Spiral-CT for Portal Vein Disorders

    Institute of Scientific and Technical Information of China (English)

    李震; 胡道予; 肖明

    2004-01-01

    Summary: The diagnostic value of 16-slices spiral computed tomography (CT) for portal vein disorders was evaluated. Forty-one patients were scanned by the 16-slices spiral-CT. The celiac trunk,portal vein and their branches were reconstructed by volume rendering (VR), multiplanar volume reconstruction (MPVR) and maximum intensity projection (MIP) technique, and the results were compared with digital subtraction angiography (DSA). VR, MPVR and MIP could display celiac trunk, portal vein, inferior vena cava and their branches and extent of portal vein-vena cava shunt,portal vein emboli and the fistula of hepatic artery-portal vein. The results from 16-slices CT were better than DSA and identical with pathologic ones. The vessel three-dimension reconstruction technique of 16-slices spiral CT is valuable for evaluating the portal systemic disorders.

  3. Hyaline cartilage thickness in radiographically normal cadaveric hips: comparison of spiral CT arthrographic and macroscopic measurements.

    Science.gov (United States)

    Wyler, Annabelle; Bousson, Valérie; Bergot, Catherine; Polivka, Marc; Leveque, Eric; Vicaut, Eric; Laredo, Jean-Denis

    2007-02-01

    To assess spiral multidetector computed tomographic (CT) arthrography for the depiction of cartilage thickness in hips without cartilage loss, with evaluation of anatomic slices as the reference standard. Permission to perform imaging studies in cadaveric specimens of individuals who had willed their bodies to science was obtained from the institutional review board. Two independent observers measured the femoral and acetabular hyaline cartilage thickness of 12 radiographically normal cadaveric hips (from six women and five men; age range at death, 52-98 years; mean, 76.5 years) on spiral multidetector CT arthrographic reformations and on coronal anatomic slices. Regions of cartilage loss at gross or histologic examination were excluded. CT arthrographic and anatomic measurements in the coronal plane were compared by using Bland-Altman representation and a paired t test. Differences between mean cartilage thicknesses at the points of measurement were tested by means of analysis of variance. Interobserver and intraobserver reproducibilities were determined. At CT arthrography, mean cartilage thickness ranged from 0.32 to 2.53 mm on the femoral head and from 0.95 to 3.13 mm on the acetabulum. Observers underestimated cartilage thickness in the coronal plane by 0.30 mm +/- 0.52 (mean +/- standard error) at CT arthrography (P cartilage thicknesses at the different measurement points was significant for coronal spiral multidetector CT arthrography and anatomic measurement of the femoral head and acetabulum and for sagittal and transverse CT arthrography of the femoral head (P cartilage thickness from the periphery to the center of the joint ("gradients") were found by means of spiral multidetector CT arthrography and anatomic measurement. Spiral multidetector CT arthrography depicts cartilage thickness gradients in radiographically normal cadaveric hips. (c) RSNA, 2007.

  4. Spiral CT of Non-Graft Post Cardiac Surgery Complications: A Pictorial Essay

    Directory of Open Access Journals (Sweden)

    S. Shirani

    2010-06-01

    Full Text Available Spiral CT is a rapidly growing method for noninvasive visualization of post-operative complications, including post-operative complications in CABG (coronary artery bypass graft. In the recent years, several different, yet more efficient types have been introduced with progressive improvement in the diagnostic accuracy in the detection of post-operative complications. The introduction of 64-slice technology, which allows high resolution as well as reconstructed images, has resulted in further progress in the diagnostic process. This kind of diagnostic equipment will spread rapidly in the world. Although studies with large numbers of patients regarding spiral CT as a routine diagnostic method have not been reported, there is great need for it all over the world. In this article, we intend to review the spiral CT findings of non-graft complications in patients after cardiac surgery.

  5. Dynamic CT myocardial perfusion imaging.

    Science.gov (United States)

    Caruso, Damiano; Eid, Marwen; Schoepf, U Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie; Spandorfer, Adam; Laghi, Andrea; De Cecco, Carlo N

    2016-10-01

    Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  6. Spiral CT arthrography of the knee: technique and value in the assessment of internal derangement of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Vande B.C.; Lecouvet, F.E.; Maldague, B.; Malghem, J. [Department of Radiology, Cliniques Universitaires St. Luc, Universite Catholique de Louvain, Brussels (Belgium); Poilvache, P. [Department of Orthopedic Surgery, Cliniques Universitaires St. Luc, Universite Catholique de Louvain, Brussels (Belgium)

    2002-07-01

    Computed tomography imaging has achieved excellent multiplanar capability and submillimeter spatial resolution due to the development of the spiral acquisition mode and multidetector row technology. Multidetector spiral CT arthrography (CTA) yields valuable information for the assessment of internal derangement of the joints. This article focuses on the value of spiral CTA of the knee in the assessment of the meniscus, anterior cruciate ligament, and hyaline cartilage lesions. Advantages and disadvantages of spiral CTA with respect to MR imaging are presented. (orig.)

  7. Correlation between contrast enhancement of portal vein and spleen size in dual-phase spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Seung Eon; Choi, Jong Cheol; Nam, Kyung Jin; Jung, Won Jung; Goo, Bong Sik; Park, Byung Ho; Lee, Young Ii; Chung, Duck Hwan [Donga Univ. College of Medicine, Pusan (Korea, Republic of)

    1996-10-01

    To evaluate using spiral CT the effect of spleen size on blood flow in the portal venous system and to know the usefulness of this evaluation. Fifty-one patients without evidence on spiral CT scan of abnormality thought to affect portal venous flow presented between December 1994 and June 1995. We measured spleen size and Hounsfield units of portal vein in dual-phase, and calculated the ratio of the unit in the portal phase to that in the arterial phase. Spleen size was measured, using the length of X-axis by that of Z-axis on spiral CT scan. We then measured the correlation between the two values. CT was performed with a Somatom Plus-S scanner(Siemens, Erlangen, Germany). A total dose of 120ml of non-ionic contrast material(Ultravist) was administered at a rate of 3 ml/sec. Arterial and portal phase were obtained after 30 seconds and 60 seconds from the begining of the contrast agent injection. The correlation between spleen size and contrast enhancement of the portal vein was relatively significant(Pearson's correlation coefficient(r)=0.41801). Spleen size significantly affects portal venous flow on spiral CT scan. The evaluation of spleen size and contrast enhancement of the portal vein could be useful in the differential diagnosis of diseases which affect portal venous flow.

  8. Acute ureteric calculus obstruction: unenhanced spiral CT versus HASTE MR urography and abdominal radiograph.

    Science.gov (United States)

    Regan, F; Kuszyk, B; Bohlman, M E; Jackman, S

    2005-06-01

    The aim of this study is to compare the performance of unenhanced spiral CT to the combination of HASTE MR urography (MRU) and plain abdominal radiography (KUB) in patients suspected of having acute calculus ureteric obstruction. 64 patients with suspected acute calculus ureteric obstruction were evaluated. The presence of perirenal fluid, presence and level of ureteric obstruction and calculi were assessed on both techniques. 44 of 64 (69%) patients had acute calculus ureteric obstruction based on clinical, radiographic or surgical findings. MRU showed perirenal fluid in acute ureteric obstruction (77%) with a greater sensitivity than CT showed stranding (45%). The combination of fluid and ureteric dilation on MRU showed a sensitivity of 93% (CT 80%), specificity of 95% (CT 85%), and accuracy of 94% (CT 81%). There were 61 findings of either fluid or ureteric dilatation on MRU in 44 acutely obstructed kidneys compared with 37 similar findings on CT (p0.75) in the finding of perirenal fluid on MRU, there was only fair interobserver agreement (KappaMRU/KUB showed ureteric calculi in 21/29 (72%) of patients with calculi seen by CT. Overall, MRU/KUB revealed 2.4 abnormalities per acutely obstructed ureter compared with 1.8 abnormalities detected by CT. MRU/KUB using HASTE sequences can diagnose the presence of acute calculus ureteric obstruction with similar accuracy to spiral CT. The technique has less observer variability and is more accurate than CT in detecting evidence of obstruction such as perirenal fluid.

  9. Clinical significance of multislice spiral CT scans in hepatic veins occlusion in Budd-Chiari syndrome

    Institute of Scientific and Technical Information of China (English)

    MENG Xiao-chun; ZHU Kang-shun; QIN Jie; ZHANG Jian-sheng; WANG Xiao-hong; ZOU Yan; ZHANG Ya-qin; SHAN Hong

    2007-01-01

    Background Budd-Chiari syndrome with hepatic vein occlusion (HVBCS) can induce severe portal hypertension and liver damage. We retrospectively analyzed hepatic CT features of HVBCS and evaluated the usefulness of triphasic enhancement of CT examinations and CT angiography (CTA) in its diagnosis.Methods Twenty-five cases with HVBCS, confirmed by digital subtraction angiography (DSA), received a triphasic enhancement CT scan within one week before DSA. The CTA images of the relevant blood vessels were reconstructed with maximum intensity projection, volume rendering and oblique reformat techniques.Results Compared with DSA, the detection rate of transverse CT and CTA images for abnormal hepatic vein were 81.7% (58/71) and 95.8% (68/71) (χ2=7.044, P=0.008), for membranous obstruction were 47.4% (9/19) and 84.2% (16/19) respectively (χ2 =5.729, P=0.017 ), for segmental obstruction were 88.0% (22/25) and 100% (25/25) respectively (χ2=1.418, P=0.234). The detection rates for hepatic vein stenosis were 100% with each method. Diffuse hepatomegaly was found in all 6 cases in acute phase and 3 of 19 cases in chronic phase who had severe obstruction of three hepatic veins without patent intrahepatic collaterals. The other 16 cases in chronic phase had hepatatrophia to different extents related to the obstructed hepatic vein. All in acute phase and 15 in chronic phase presented typical patchy enhancement initially in caudate lobe and perihilar areas and enlarged with time delay. In all cases, parenchyma areas with atrophy, necrosis and congestion demonstrated lower and later enhancement. In all the parts, which had normal enhancement at least one patent outflow hepatic vein, accessory hepatic vein or collateral vessel was detected. Conclusion Dynamic enhancement CT examination by multislice spiral CT not only could improve the diagnosis of HVBCS by CTA technique, but also could noninvasively provide anatomical information and reveal damage to the hepatic parenchyma.

  10. Epidurography: Comparison with CT-, helical-CT- and MR-Epidurography; Die Epidurographie: Vergleich mit CT-, Spiral-CT- und MR-Epidurographie

    Energy Technology Data Exchange (ETDEWEB)

    Tomczak, R. [Univ. Ulm, Klinik fuer Radiologie (Germany); Seeling, W. [Univ. Ulm, Klinik fuer Anaesthesiologie (Germany); Rieber, A. [Univ. Ulm, Klinik fuer Radiologie (Germany); Sokiranski, R. [Univ. Ulm, Klinik fuer Radiologie (Germany); Rilinger, N. [Univ. Ulm, Klinik fuer Radiologie (Germany); Brambs, H.J. [Univ. Ulm, Klinik fuer Radiologie (Germany)

    1996-08-01

    liegenden Epiduralkathetern (EK) und drei Probanden nach Anlage eines EK wurden nach Injektion von Gadolinium-DTPA einer MR-Epidurographie, die drei Probanden zusaetzlich einem Doppel-Helix-Spiral-CT nach Injektion von jodhaltigem Kontrastmittel unterzogen. Ergebnisse: 40% der Patienten zeigten ein Schienenstrangphaenomen bedingt durch eine unterschiedlich starke Fuellung des Epiduralraumes mit Kontrastmittel im Bereich der Wirbelboegen und des Zwischenwirbelbogenbereiches, 76% der Patienten zeigten keinen ventralen thorakalen Epiduralraum, 56% eine Aufhellungslinie im a.-p. Bild der Epidurographie, die als Plica mediana dorsalis im CT identifiziert wurde. Die vorbeschriebenen Phaenomene wurden auch bei allen in der Spiral-CT- und MR-Epidurographie untersuchten Personen nachgewiesen. Schlussfolgerung: Die CT-Epidurographie ist geeignet zur Erklaerung von Bildmustern der Epidurographie. (orig.)

  11. The effect of pitch and collimation on radiation dose in spiral CT

    Institute of Scientific and Technical Information of China (English)

    CHENG Qi-Jun; TSANG Cheung; FENG Ding-Hua

    2005-01-01

    Measurements of radiation dose to patients in spiral computed tomography (CT) were completed for various collimations, table speeds and pitch. A standard CT head dosimetry phantom and thermoluminescent dosimeters (TLD) were used for the measurement. The.effect of collimation and pitch on radiation dose was studied. The results indicated that the radiation dose at the given tube current, voltage and rotation speed was inversely proportional to pitch. And the increasing times of dose were as decreasing times of pitch. This regular pattern was tenable for radiation dose at both central holes and peripheral holes of the phantom at pitch = 1, >1 and <1. The collimation had no impact on the radiation dose. The results also indicated that radiation dose at central holes was nearly equal to that at peripheral holes. There was no significant difference between them statistically. The study demonstrates that the pitch in spiral CT scans is the primary parameter and has significant impact on radiation dose.

  12. Effects of semiclassical spiral fluctuations on hole dynamics

    Science.gov (United States)

    Hamad, I. J.; Manuel, L. O.; Trumper, A. E.

    2012-01-01

    We investigate the dynamics of a single hole coupled to the spiral fluctuations related to the magnetic ground states of the antiferromagnetic J1-J2-J3 Heisenberg model on a square lattice. Using exact diagonalization on finite size clusters and the self-consistent Born approximation in the thermodynamic limit, we find, as a general feature, a strong reduction of the quasiparticle weight along the spiral phases of the magnetic phase diagram. For an important region of the Brillouin zone the hole spectral functions are completely incoherent, whereas at low energies the spectral weight is redistributed on several irregular peaks. We find a characteristic value of the spiral pitch Q=(0.7,0.7)π, for which the available phase space for hole scattering is maximum. We argue that this behavior is due to the nontrivial interference of the magnon-assisted and the free-hopping mechanism for hole motion, characteristic of a hole coupled to semiclassical spiral fluctuations.

  13. Controlling Spiral Dynamics in Excitable Media by a Weakly Localized Pacing

    Institute of Scientific and Technical Information of China (English)

    LI Bing-Wei; SUN Li-Li; CHEN Bin; YING He-Ping

    2007-01-01

    @@ Spiral dynamics controlled by a weakly localized pacing around the spiral tip is investigated. Numerical simulations show two distinct characteristics when the pacing is applied with the weak amplitude for suitable frequencies:for a rigidly rotating spiral, a transition from rigid rotation to meandering motion is observed, and for unstable spiral waves, spiral breakup can be prevented. Successfully preventing spiral breakup is relevant to the modulation of the tip trajectory induced by a localized pacing.

  14. Spiral CT during pharmacoangiography with angiotensin II in patients with pancreatic disease. Technique and diagnostic efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, C.; Mihara, N.; Hosomi, N.; Inoue, E.; Fujita, M. [Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan). Dept. of Diagnostic Radiology; Ohigashi, H.; Ishikawa, O. [Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan). Dept. of Surgery; Nakaizumi, A. [Osaka Medical Center for Cancer and Cardiovascular Deseases (Japan). Dept. of Internal Medicine; Ishiguro, S. [Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan). Dept. of Pathology

    1998-03-01

    Purpose: To compare the diagnostic efficacy of pancreatic pharmacoangiographic CT using angiotensin II with conventional angiographic CT. Material and Methods: Eighteen patients with space-occupying pancreatic disease were examined in this study. Pharmacoangiographic CT was performed with a 1-3-{mu}/6-ml solution of angiotensin II injected through a catheter into the celiac artery during spiral CT. Results: In 17 of the 18 (94%) patients, the area of pancreatic parenchymal enhancement was the same or larger at pharmacoangiographic CT than at conventional angiographic CT. The attenuation value of the pancreatic parenchyma was significantly increased at pharmacoangiographic CT (p=0.0010). Although the attenuation value of tumors was also increased on images obtained after the injection of angiotensin II, the tumor-to-pancreas contrast was significantly greater at pharmacoangiographic CT (p=0.0479). The mean differences in attenuation between tumor and pancreas at angiographic CT with and without angiotensin II were respectively 182 HU and 115 HU. Conclusion: Pharmacoangiographic CT with angiotensin II proved superior to conventional angiographic CT in the diagnosis of pancreatic disease. We therefore recommend it as a supplementary technique at the angiographic examination of patients with suspected pancreatic tumor. (orig.).

  15. Spiral CT of acute pulmonary thromboembolism: evaluation of pleuroparenchymal abnormalities.

    Science.gov (United States)

    Johnson, P T; Wechsler, R J; Salazar, A M; Fisher, A M; Nazarian, L N; Steiner, R M

    1999-01-01

    The goal of this work was to identify and categorize the spectrum of pulmonary parenchymal and pleural abnormalities identified by CT in patients with acute pulmonary thromboembolism (PE). A review of interpretations from 4,715 consecutive contrast-enhanced thoracic CT studies identified 41 examinations in which the diagnosis of PE was reported. Thirty-four studies were available for review, and two radiologists confirmed intraluminal defects in 31 patients. The number of emboli were counted and localized using bronchopulmonary nomenclature. Associated parenchymal and pleural abnormalities were tabulated. Of the 31 patients, 13 underwent confirmatory or correlative studies including angiography, radionuclide study, or autopsy. In addition, deep venous thrombosis was confirmed by ultrasound or MRI in 13 patients. An average of 7.5 emboli per patient was detected. Pleuroparenchymal findings were as follows: Nine patients (29%) had no acute pulmonary parenchymal or pleural abnormality. In the remaining 22 patients, pleural effusion was the most common abnormality, found in 14 of 31 (45%). Ten patients (32%) had peripheral wedge-shaped parenchymal opacities suggestive of pulmonary infarction. Normally enhancing lobar atelectasis was seen in nine patients (29%). Six patients (19%) demonstrated heterogeneous parenchymal enhancement within nonaerated lung, two of whom had pathologically proven pulmonary infarct. Thirteen of 31 patients underwent high resolution CT; a typical mosaic perfusion pattern was seen in only 1 patient. Twenty-nine percent of patients with acute PE had no acute lung parenchymal abnormality on CT; thus, the absence of parenchymal abnormality on CT does not exclude PE. High resolution CT mosaic perfusion was not a common feature of acute pulmonary embolism. Regions of decreased enhancement within nonaerated lung, seen in 19%, may prove to be an indicator of pulmonary infarction; however, this is a nonspecific finding.

  16. Spiral-CT angiography after intraarterial iliac stent placement; Spiral-CT-Angiographie nach arterieller iliakaler Stentapplikation

    Energy Technology Data Exchange (ETDEWEB)

    Freund, M. [Kiel Univ. (Germany). Klinik fuer Radiologische Diagnostik; Palmie, S. [Kiel Univ. (Germany). Klinik fuer Radiologische Diagnostik; Wesner, F. [Kiel Univ. (Germany). Klinik fuer Radiologische Diagnostik; Heller, M. [Kiel Univ. (Germany). Klinik fuer Radiologische Diagnostik

    1995-10-01

    In a prospective study 32 patients underwent CT-A after stent placement in the iliac arteries. The vascular morphology was analyzed regarding neointimal hyperplasia and calcification pattern. The results were compared with those of clinical findings (walking distance), Doppler ultrasound (ankle-brachial index) and DSA. All 47 stents were visible and patent (100%). One misplacement was identified. A good correlation was found between an improved ankle-brachial index and CT-A (88.5%) and extension of the walking distance and CT-A (92.3%). Concerning location, number and grade of stenoses the results between CT-A and DSA matched in 42.1%. An exact mapping of calcified plaques was possible in all cases. (orig./MG) [Deutsch] Nach perkutaner transluminaler Angioplastie (PTA) und Stenteinlage wurden 32 Patienten prospektiv mittels CT-A untersucht. Es erfolgte eine Analyse der Gefaessmorphologie hinsichtlich neointimaler Hyperplasien und Verkalkungsmuster. Weiterhin wurden die Ergebnisse mit denen der intraarteriellen digitalen Subtraktionsangiographie (i.a. DSA), dem klinischen Befund (Gehstrecke) und der Doppler-Ultraschalluntersuchung (Arm-Knoechel-Index/AKI) verglichen. Alle 47 Stents konnten in der CT-A exakt lokalisiert und als offen identifiziert werden (100%). Eine Stentfehllage wurde diagnostiziert. Der Nachweis neointimaler Hyperplasie gelang aufgrund von Metallartefakten im Stentniveau nicht. Verkalkungen waren in allen Faellen nachweisbar. Eine Uebereinstimmung zwischen DSA und CT-A hinsichtlich des Schweregrades, der Anzahl und Lokalisation von Stenosen fand sich nur in 42,1%. In 88,5% der Faelle bestand eine Uebereinstimmung zwischen CT-morphologischem Befund und verbessertem AKI, in 92,3% mit verlaengerter Gehstrecke. (orig./MG)

  17. Stellenwert des Nativ-Spiral-CT in der Diagnostik von Ureterkonkrementen

    Directory of Open Access Journals (Sweden)

    Rau O

    2006-01-01

    Full Text Available Die differentialdiagnostische Vorgehensweise bei Pat. mit einer Urolithiasis, insbesondere bei Pat. mit nicht schattengebenden Konkrementen im konventionellen Röntgen, ist oftmals schwierig. Wir evaluierten den Einsatz des Nativ-Spiral-CT in dieser Patientengruppe. Die Sensitivität und Spezifität variiert in der Literatur zwischen 80 und 100 %. Zwischen 4/99 und 11/04 führten wir bei 103 Patienten (Pat. mit kolikartigen Flankenschmerzen, aber ohne Steinnachweis im konventionellen Röntgen, ein natives Spiral-CT durch. Zusätzlich verglichen wir mit dem korrespondierenden Ultraschall und der dazugehörigen Urinanalyse. Endpunkte unserer Untersuchung waren einerseits (A der makroskopische Steinnachweis, entweder als spontan abgegangenes Konkrement oder nach interventioneller Bergung des Konkrementes, bzw. (B kein Nachweis eines Konkrementes. Ein Steinnachweis ließ sich bei 55/103 Pat. führen. Bei 41/55 ließ sich mittels Spiral-CT das Konkrement bestätigen. Dies entspricht einer Spezifität von 75 %. 49 der 55 Pat. hatten zusätzlich eine Erythrozyturie und ebenfalls 49/55 zeigten im Ultraschall eine Dilatation des Nierenbeckenkelchsystems. Bei 48 Pat. von 103 wurden keine Konkremente gesichert. Bei 39 Pat. ließ sich in dieser Gruppe im Spiral-CT ebenfalls kein Konkrementnachweis führen, was einer Sensitivität von 82 % entspricht. Falsch positive Ergebnisse bei 9 Pat. ließen sich retrospektiv in der Auswertung der Spiral-CT’s auf Kalzifizierung benachbarter Strukturen zurückführen. Bei 34/48 wurde eine Erythrozyturie und bei 32/48 eine Dilatation des oberen Harntraktes diagnostiziert. Retrospektiv wurden diese Symptome auf eine infektiöse Mitbeteiligung des Retroperitonealraumes zurückgeführt. Zusätzlich ließ sich eine Raumforderung der Leber, eine Raumforderung im Bereich des proximalen Femur und drei Kolontumore sichern. Unsere Serie von Spiral-CT’s bei Pat. ohne Konkrementnachweis im konventionellen Röntgen zeigte eine

  18. The Analysis of Blood Flow Dynamics About 64-slice Spiral CT Perfusion Imaging for Primary Liver Cancer%原发性肝癌患者64层螺旋CT灌注成像血流动力学分析

    Institute of Scientific and Technical Information of China (English)

    孙建华

    2015-01-01

    目的:探讨原发性肝癌患者64层螺旋CT灌注成像血流动力学的表现。方法收集2012年8月~2013年7月来我院就诊的确诊为原发性肝癌的患者46例并将其作为观察组,选取2012年8月~2013年7月来我院进行健康体检的健康对象46例并将其作为对照组,血液流动力学表现采用64层螺旋CT灌注成像观察,检测并比较两组患者肝动脉灌注量、肝门静脉灌注量、总肝灌注量、肝动脉灌注指数。结果观察组肝动脉灌注量、肝动脉灌注指数高于对照组,肝门静脉灌注量、总肝灌注量低于对照组,两组差异有统计学意义(P<0.05)。结论原发性肝癌患者采用64层螺旋CT灌注成像诊断血液流动力学表现较为显著,具有较高的诊断价值。%Objective To Einvestigate the blood flow dynamics about 64-slice spiral CT perfusion imaging for primary liver cancer. Methods 46 patients with primary liver cancer diagnosed in our hospital were collected from August 2012 to July 2013 and taken as the observation group, 46 cases of health object for physical examination in our hospital were selected at the same time as the control group, observed the blood lfow dynamics performance used by 64-slice spiral CT perfusion imaging, the two groups were measured and compared about hepatic arterial perfusion, hepatic portal vein perfusion, total liver perfusion, hepatic perfusion index. Results Hepatic arterial perfusion, hepatic perfusion index of observation group were higher, the hepatic portal vein perfusion, total hepatic perfusion were lower than the control group, the difference was statistically significant (P<0.05). Conclusions Primary liver cancer patients use 64-slice spiral CT perfusion imaging in the diagnosis of blood lfow dynamics performance is more signiifcant, with high diagnostic value.

  19. Optimal scan time of dual-phase spiral CT in normal rabbit liver : effect of contrast injection rate

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Byung Kook; Kim, Sang Ho; Liu, Wei Chiang [Sungae General Hospital, Seoul (Korea, Republic of)] (and others)

    1999-06-01

    To determine the effect of contrast injection rate on rabbit liver enhancement and the optimal temporal window for dual-phase spiral CT of rabbit liver at each injection rate Using spiral CT, seven New Zealand White rabbits underwent dynamic scanning at one level of liver. Three protocols of contrast injection rates were employed, namely 0.3ml/sec(group 1), 1 ml/sec(group 2) and 2 ml/sec(group 3). During 120 seconds of total scan time, the scan interval was 3 seconds. Densities of the aorta, liver and portal vein were averaged in equivalent time. The different injection rate protocols were compared for peak enhancement/time on a time density curve. Mean peak enhancement (HU) in equivalent time(secs) was 310/18(group 1), 383/9(group 2) and 357/6(group 3) in the aorta ; 34/36, 40/36 and 41/30 in the liver ; and 135/36, 153/24 and 170/21 in the portal vein. The temporal window during the arterial phase was 12-21 sec(group 1), 6-12 sec(group 2), and 6-12 sec(group 3). The temporal window during the portal phase was from 30 sec(0.3ml/sec), 21 sec(1ml/sec) and 21sec(2ml/sec). During dual-phase spiral CT, the temporal window for liver scanning should be determined according to each contrast injection rate. A slow contrast injection rate prolongs the temporal window during the arterial phase.

  20. Hepatic tumors in children: Spiral CT findings and their significance for differential diagnosis; Lebertumoren bei Kindern: Spiral-CT-Befunde und ihre differentialdiagnostische Einordnung

    Energy Technology Data Exchange (ETDEWEB)

    Herzberg, C.; Maas, R.; Buecheler, E. [Universitaetsklinik Hamburg-Eppendorf (Germany). Abt. fuer Roentgendiagnostik

    1998-05-01

    Liver tumors in childhood are rare. They can be subdivided in benign or primary and secundary malignent liver tumors. The prognosis of malignant liver disease has improved due to extended therapy in the past few years. Thus, diagnosis of liver tumors in childhood gains in significance. After a suspect ultrasound diagnosis, usually computed tomography (CT) is used as a radiologic sectioning method. Guided by a retrospective analysis of 15 cases, the importance of the Helical-CT is presented. Helical-CT is a good diagnostic method for pediatric cases due to reduced scan times. By the basis of clinical data, distribution, and density, various differential diagnoses can be made. Benign liver tumors, especially cysts and frequently haemangioma, can easily be diagnosed and controlled because of their typical echogenicity and contrast visualisation. In cases of hamartoma, focal nodal hyperplasia, and adenoma computed tomography diagnosis is often necessary. Primary malignant liver tumors can prove to be unilocular hepatoblastomas or hepatocellular carcinomas, while disseminated liver invasions usually are considered as metastatic liver tumors of kidney or adrenal cancer. (orig.) [Deutsch] Lebertumoren bei Kindern sind sehr selten. Man unterscheidet gutartige, primaer und sekundaer maligne Lebertumoren. Die Prognose maligner Lebererkrankungen hat sich aufgrund erweiterter Therapiemoeglichkeiten in den letzten Jahren zunehmend gebessert. Dadurch gewinnt die Diagnostik kindlicher Leberturmoren wieder an Bedeutung. In der Regel wird nach einem Verdachtsbefund im Ultraschall die Computertomographie (CT) als radiologisches Schnittbildverfahren eingesetzt. Anhand von 15 retrospektiv analysierten Faellen soll die Bedeutung der Spiral-CT dargestellt werden. Die Spiral-CT ist aufgrund ihrer kurzen Scanzeit besonders gut fuer paediatrische Fragestellungen geeignet. Anhand von klinischen Daten, Verteilungsmustern und Dichteverhalten lassen sich verschiedene Differentialdiagnosen

  1. SPECT/spiral-CT hybrid imaging in unclear foci of increased bone metabolism: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Roemer, W.; Kuwert, T. [Nuklearmedizinische Klinik, Friedrich-Alexander-Univ. Erlangen/Nuernberg (Germany); Beckmann, M.W. [Frauenklinik, Friedrich-Alexander-Univ. Erlangen/Nuernberg (Germany); Forst, R. [Lehrstuhl fuer Orthopaedie mit Orthopaedischer Chirurgie, Friedrich-Alexander Univ. Erlangen/Nuernberg (Germany); Bautz, W. [Radiologisches Inst., Friedrich-Alexander-Univ. Erlangen/Nuernberg (Germany)

    2005-07-01

    In bone scintigraphy, the differentiation between degenerative processes and bone metastases is still difficult. Therefore, additional radiological studies are regularly needed after bone scintigraphy. The now introduced hybrid-cameras combining single-photon emission computed tomography (SPECT) and spiral-CT are unique in the sense that they offer the opportunity to correlate the functional information with morphology in one session. We herein present two patients in whom this technological setup allowed a definite diagnosis in scintigraphically unclear vertebral lesions. In a patient with breast cancer, hypermetabolic lesions were clearly correlated with osteolyses. In another patient with synovial carcinoma, spondylosis and spondylarthrosis caused focal tracer uptake in the lumbar spine. In addition to an improved diagnostic accuracy, SPECT/Spiral-CT will considerably abbreviate the diagnostic process. (orig.)

  2. Hepatic hemangioma: contrast enhancement patterns on two-phase spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Eun Joo; Choi, Byung Ihn; Han, Joon Koo; Jang, Hyun Jung; Kim, Tae Kyoung; Kim, Ah Young; Lee, Ki Yeol [Seoul National Univ., Seoul (Korea, Republic of). Coll. of Medicine

    1998-01-01

    To evaluate contrast enhancement patterns of hemangioma according to size, as seen during the arterial and portal venous phase of spiral CT. Overall, the most common enhancement pattern was peripheral high (44/82, 53.7%), during the arterial and portal venous phase. The second and third most common patterns were uniform high (11/82, 13.4%) and peripheral high-uniform high (9/82, 11.0%), also during the arterial and portal venous phase. In tumors smaller than 20 mm, low-low attenuation was seen in eight (9.8%), and iso-low attenuation in two (2.4%), during the arterial and portal venous phase, respectively. On two-phase spiral CT, the most common enhancement pattern of hemangioma was peripheral high, seen during the arterial and portal venous phase. However, a small hemangioma less than 2cm may show atypical patterns, including low and iso attenuation. (author). 23 refs., 1 tab., 4 figs.

  3. Peripheral pulmonary arteries: identification at multi-slice spiral CT with 3D reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Coche, Emmanuel; Pawlak, Sebastien; Dechambre, Stephane; Maldague, Baudouin [Department of Radiology, St. Luc Hospital, UCL, Avenue Hippocrate, 10, 1200 Brussels (Belgium)

    2003-04-01

    Our objective was to analyze the peripheral pulmonary arteries using thin-collimation multi-slice spiral CT. Twenty consecutive patients underwent enhanced-spiral multi-slice CT using 1-mm collimation. Two observers analyzed the pulmonary arteries by consensus on a workstation. Each artery was identified on axial and 3D shaded-surface display reconstruction images. Each subsegmental artery was measured at a mediastinal window setting and compared with anatomical classifications. The location and branching of every subsegmental artery was recorded. The number of well-visualized sub-subsegmental arteries at a mediastinal window setting was compared with those visualized at a lung window setting. Of 800 subsegmental arteries, 769 (96%) were correctly visualized and 123 accessory subsegmental arteries were identified using the mediastinal window setting. One thousand ninety-two of 2019 sub-subsegmental arteries (54%) identified using the lung window setting were correctly visualized using the mediastinal window setting. Enhanced multi-slice spiral CT with thin collimation can be used to analyze precisely the subsegmental pulmonary arteries and may identify even more distal pulmonary arteries. (orig.)

  4. Peripheral pulmonary arteries: identification at multi-slice spiral CT with 3D reconstruction.

    Science.gov (United States)

    Coche, Emmanuel; Pawlak, Sebastien; Dechambre, Stéphane; Maldague, Baudouin

    2003-04-01

    Our objective was to analyze the peripheral pulmonary arteries using thin-collimation multi-slice spiral CT. Twenty consecutive patients underwent enhanced-spiral multi-slice CT using 1-mm collimation. Two observers analyzed the pulmonary arteries by consensus on a workstation. Each artery was identified on axial and 3D shaded-surface display reconstruction images. Each subsegmental artery was measured at a mediastinal window setting and compared with anatomical classifications. The location and branching of every subsegmental artery was recorded. The number of well-visualized sub-subsegmental arteries at a mediastinal window setting was compared with those visualized at a lung window setting. Of 800 subsegmental arteries, 769 (96%) were correctly visualized and 123 accessory subsegmental arteries were identified using the mediastinal window setting. One thousand ninety-two of 2019 sub-subsegmental arteries (54%) identified using the lung window setting were correctly visualized using the mediastinal window setting. Enhanced multi-slice spiral CT with thin collimation can be used to analyze precisely the subsegmental pulmonary arteries and may identify even more distal pulmonary arteries.

  5. Power doppler ultrasound findings of renal infarct after experimental renal artery occlusion: comparison with spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seung Eun; Shinn, Kyung Sub; Kim, Hak Hee; Mun, Seok Hwan; Lee, Young Joon; Lee, Bae Young; Choi, Byung Gil; Lee, Jae Mun; Lee, Hee Jeong [The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of)

    1999-02-01

    To evaluate the efficacy of power Doppler ultrasonography (PDUS) in depicting renal infarction in rabbits during experimental renal segmental arterial occlusion, and to compare the results with those of CT scanning. In 28 rabbits weighing 2.5 4kg, the segmental renal artery was occluded through the left main renal artery by embolization with Ivalon (Nycomed, Paris, France). Power Doppler ultrasonography and spiral CT scanning were performed before and at 2, 5, 8, 15, and 24 hours, and 3 and 7 days after occlusion of the segmental renal artery. The location of infarcted areas and collaterals, as seen on PDUS and CT scans, was evaluated by two radiologists. In all cases, as seen on power Doppler ultrasonography, infarcted areas-when compared with normal parenchyma, clearly demonstrated wedge-shaped perfusion defects in the kidney. The location of the lesion closely corresponded to the location seen during CT scanning. After renal arterial occlusion, transiently congested capsular arteries, which were named 'capsular sign', were seen in 63% of rabbits in the two and five-hour groups. No significant cortical rim sign was demonstrated on power Doppler ultrasonography, though it was noted on spiral CT at 15 and 24 hours, and 3 and 7 days after renal arterial occlusion. Power Doppler ultrasonography was useful for the diagnosis of renal infarction. Congested capsular artery seen in the early stage of renal infarction might be a characteristic finding of this condition, as seen on power Doppler ultrasonography.

  6. Unstable Dynamical Properties of Spiral Cloud Bands in Tropical Cyclones

    Institute of Scientific and Technical Information of China (English)

    HUANG Hong; ZHANG Ming

    2009-01-01

    A nondivergent barotropic model (Model 1) and a barotropic primitive equation vortex model (Model 2) are linearized respectively in this paper. Then their perturbation wave spectrums are computed with a normal mode approach to study the instability problem on an appointed tropical cyclone (TC)-like vortex, thereby, the dynamic instability properties of spiral cloud bands of TCs are discussed. The results show that the unstable mode of both models exhibits a spiral band-like structure that propagates away from the vortex outside the radius of maximum winds. The discrete modal instability of the pure vortex Rossby wave can account for the generation of the eyewall and the inner spiral band. The unstable mode in Model 2 has three parts, i.e., eyewall, inner and outer spiral bands. This mode can be interpreted as a mixed vortex Rossby-inertia gravitational wave. The unbalanced property of the wave outside the stagnation radius of the vortex Rossby wave is one of the important reasons for the formation of the outer spiral band in TCs. Accordingly, the outer spiral band can be identified to possess properties of an inertial-gravitational wave.When the formation of unstable inner and outer spiral bands is studied, a barotropic vortex model shall be used. In this model, the most unstable perturbation bears the attributes of either the vortex Rossby wave or the inertial-gravitational wave, depending on the vortex radius. So such perturbations shall be viewed as an unbalanced and unstable mixed wave of these two kinds of waves.

  7. Nonfunctioning endocrine tumors of the pancreas: possibilities of spiral CT characterization

    Energy Technology Data Exchange (ETDEWEB)

    Procacci, C.; Carbognin, G.; Biasiutti, C.; Bicego, E.; Romano, L.; Guarise, A.; Minniti, S.; Pagnotta, N. [Dept. of Radiology, University of Verona Medical School (Italy); Accordini, S. [Div. of Medical Statistics, University of Verona Medical School (Italy); Falconi, M. [Dept. of Surgical Sciences, University of Verona Medical School (Italy)

    2001-07-01

    The aim of this study was to assess the ability of spiral CT to adequately characterize the nonfunctioning endocrine tumors (NFETs) of the pancreas, distinguishing this lesion from the other pancreatic tumors. The spiral CT examinations of 21 cases of histologically proven NFETs, along with those of 29 cases of other pancreatic tumors and tumor-like lesions, were retrospectively reviewed in a blinded fashion by two radiologists, in order to correctly classify the lesions, highlighting the typical signs reported in the literature. Discordant cases were further analyzed in the presence of a third radiologist. The final diagnosis was acquired by means of a majority or overall consensus. The histopathologic examination was considered the gold standard. The sensitivity, specificity, and positive and negative predictive values of CT were calculated. After the consensus evaluation, the correct diagnosis was reached in 72% of cases, with 10% of nonspecific diagnoses of solid pancreatic tumor and 18% of wrong diagnoses. The sensitivity and specificity of spiral CT in identifying NFETs were 66.6 and 82.7%, respectively. The positive and negative predictive values were 73.7 and 77.4%, respectively. In up to 70% of cases the NFET demonstrates a typical aspect of a mass hyperdense in the arterial contrastographic phase eventually associated with hyperdense hepatic metastases in more than half of the patients. This finding does allow the diagnosis of NFET but without certainty indeed, since other tumors can show a similar densitometric behavior and among them particularly the ductal adenocarcinoma. On the other hand, both the solid, hypovascularized NFETs, and the cystic form, cannot be differentiated from the other solid and cystic tumors of the pancreas. (orig.)

  8. Eventful Evolution of Giant Molecular Clouds in Dynamically Evolving Spiral Arms

    CERN Document Server

    Baba, Junichi; Saitoh, Takayuki R

    2016-01-01

    The formation and evolution of giant molecular clouds (GMCs) in spiral galaxies have been investigated in the traditional framework of the combined quasi-stationary density wave and galactic shock model. However, our understanding of the dynamics of spiral arms is changing from the traditional spiral model to a dynamically evolving spiral model. In this study, we investigate the structure and evolution of GMCs in a dynamically evolving spiral arm using a three-dimensional N-body/hydrodynamic simulation of a barred spiral galaxy at parsec-scale resolution. This simulation incorporated self-gravity, molecular hydrogen formation, radiative cooling, heating due to interstellar far-ultraviolet radiation, and stellar feedback by both HII regions and Type-II supernovae. In contrast to a simple expectation based on the traditional spiral model, the GMCs exhibited no systematic evolutionary sequence across the spiral arm. Our simulation showed that the GMCs behaved as highly dynamic objects with eventful lives involvi...

  9. Differential diagnosis of gallbladder wall thickening by two phase spiral CT : gallbladder carcinoma versus cholicystitis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun; Cho, Soon Gu; Kim, Mi Young; Woo, Je Hong; Shin, Seok Hwan; Lee, Kykung Hee; Suh, Chang Hae [Inha Univ. College of Medicine, Inchon (Korea, Republic of)

    2001-04-01

    To determine whether an analysis of two-phase CT features provides a sound basis for differential diagnosis between gallbladder carcinoma and cholecystitis. We reviewed a total of 89 cases of gallbladder carcinoma (n=35) or cholecystitis (n=54) in patients who had undergone two-phase spiral CT. For this, a GE Highspeed Advantage scanner (GE Medical Systems, Milwaukee, U . S . A .) was used. A total of 120ml of contrast material was injected at a rate of 2-3 ml/sec. Arterial and venous phase scans were obtained 35 and 65 seconds, respectively, after the initiation of contrast infusion. All cases of gallbladder carcinoma and 468 of cholecystitis (of a total of 482) were confirmed by histopathology. We reviewed the two phase spiral CT features, analyzing and assessing thickness of the lesion, the enhancement pattern seen during the arterial and the venous phase, invasion of liver, pericholecystic fat infiltration, dilatation of intrahepatic ducts, and other associated findings. Mean wall thickness was 12.6 mm in the gallbladder carcinoma group, and 7.2 mm in the cholecystitis group. The common enhancement patterns seen in gallbladder carcinoma were 1) a highly enhanced thick inner wall layer during the arterial phase which became iso attenuated with adjacent liver parenchyma during the venous phase (16/35; 45.7%) and 2) highly enhanced thick inner wall layer during both the arterial and venous phase (8/35; 22.9%). The most common enhancement pattern in cholecystitis cases was an iso attenuated thin inner wall layer during both the arterial and the venous phase (44/54; 81.5%). Findings of intrahepatic mass formation by direct invasion (9/35), lymph node enlargement (12/35), and metastasis to other organs (7/35) occurred only in cases of gallbladder carcinoma (18/35, 51.4%) than of cholecystitis (10/54, 18.5%). The incidence of pericholecystic fat infiltration and fluid collection was not significantly different between the gallbladder cancer and cholecystitis groups

  10. Dosimetry in dental radiology. Dentascan spiral CT versus panoramic radiography; Dosimetria nella radiologia odontostomatologica: confronto tra tomografia computerizzata spirale e ortopantomografia

    Energy Technology Data Exchange (ETDEWEB)

    Villari, N.; Stecco, A.; Zatelli, G. [Florence Univ., Florence (Italy). Dipt. di fisiopatologia clinica

    1999-05-01

    The study compares the doses absorbed by the dentomaxillary area in spiral CT and panoramic examinations. The dose measurements demonstrate that patients receive smaller doses with panoramic radiography than with spiral CT with Dentascan. After following for some variations from instrumental differences, they are in substantial agreement with literature data. Further investigations are needed considering the radiobiological risk related to the growing spread of Dentascan examinations. [Italian] Questo lavoro intende confrontare le dosi assorbite nel distretto dento-mascellare, con le due principali tecniche utilizzate in questo campo: TC spirale e ortopantomografia. Emerge come l'esame panoramico delle arcate dentarie eseguito con l'ortopantomografo comporti la'ssorbimento di dosi inferiori rispetto a quelle dell'esame TC spirale con programma Dentascan. Questi dati, pur essendo soggetti a variabilita' dovuta alla strumentazione utilizzata, sono paragonabili a quelli di altri studi e impongono ulteriori approfondimenti dato il crescente ricorso degli implantologi alla TC spirale con programma di ricostruzione Dentascan.

  11. Dose reduction in spiral CT angiography of thoracic outlet syndrome by anatomically adapted tube current modulation

    Energy Technology Data Exchange (ETDEWEB)

    Mastora, I.; Remy-Jardin, M.; Remy, J. [Dept. of Radiology, University Center Hospital Calmette, Lille (France); Medical Research Group, Lille (France); Suess, C.; Scherf, C. [Siemens Medical Systems, Forcheim (Germany); Guillot, J.P. [Dept. of Radiology, University Center Hospital Calmette, Lille (France)

    2001-04-01

    The aim of this study was to evaluate dose reduction in spiral CT angiography of the thoracic outlet by on-line tube-current control. Prospectively, 114 patients undergoing spiral CT angiography of the subclavian artery for thoracic outlet arterial syndromes were evaluated with and without tube-current modulation at the same session (scanning parameters for the two successive angiograms, one in the neutral position and one after the postural maneuver): 140 kV; 206 mA; scan time 0.75 s; collimation 3 mm; pitch = (1). The dose reduction system was applied in the neutral position in the first 92 consecutive patients and after postural maneuver in the remaining 22 consecutive patients. Dose reduction and image quality were analyzed in the overall study group (group 1; n = 114). The influence of the arm position was assessed in 44 of the 114 patients (group 2), matched by the transverse diameter of the upper thorax. The mean dose reduction was 33 % in group 1 (range 22-40 %) and 34 % in group 2 (range 26-40 %). In group 2 the only difference in image quality was a significantly higher frequency of graininess on low-dose scans compared with reference scans whatever the patient's arm position, graded as minimal in 38 of the 44 patients (86 %). When the low-dose technique was applied after postural maneuver in group 2: (a) the mean dose reduction was significantly higher (35 vs 32 % in the neutral position; p = 0.006); (b) graininess was less frequent (82 vs 91 % in the neutral position); and (c) the percentage of graininess graded as minimal was significantly higher (83 vs 70 % in the neutral position; p = 0.2027). On-line tube-current modulation enables dose reduction on high-quality, diagnostic spiral CT angiograms of the thoracic outlet and should be applied during data acquisition in the neutral position and after postural maneuver for optimal use. (orig.)

  12. Thromboembolic Complications Following Spine Surgery Assessed with Spiral CT Scans: DVT/PE Following Spine Surgery.

    Science.gov (United States)

    Kim, Han Jo; Walcott-Sapp, Sarah; Adler, Ronald S; Pavlov, Helene; Boachie-Adjei, Oheneba; Westrich, Geoffrey H

    2011-02-01

    Spine surgery is associated with a significant risk of postoperative pulmonary embolism (PE) and/or deep vein thrombosis (DVT). The goal of this study was to determine which symptoms and risk factors were associated with spiral CT scans positive for PE and/or DVT in the postoperative spine surgery patient. We conducted a retrospective review of all spine patients who underwent a postoperative CT to rule out PE during the period of March 2004-February 2006. The type of surgical procedure, risk factors, symptoms prompting scan ordering, anticoagulation, and treatment were recorded. Logistic regression models were used to determine significant predictors of a positive CT in this patient population. Of the 3,331 patients that had spine surgery during the study period, 130 (3.9%) had a spiral CT scan to rule out PE and/or proximal DVT. Thirty-three of the 130 (25.4%) CT scans were positive for PE only, five (3.8%) for PE and DVT, and three (2.3%) for DVT only. Only 24.5% (32) patients had risk factors for thromboembolic disease, and of these, a history of PE and/or DVT was the only significant risk factor for a positive scan (p = 0.03). No presenting symptoms or demographic variables were noted to have a significant association with PE and/or DVT. The type of surgical procedure (i.e., anterior, posterior, and percutaneous) was not associated with an increased risk for PE and/or DVT. Patients who are undergoing spine surgery with a history of thromboembolic disease should be carefully monitored postoperatively and may benefit from more aggressive prophylaxis.

  13. Spiral (helical) CT of tracheo-bronchial diseases; La tomodensitometrie spiralee (helicoidale) en pathologie tracheobronchique

    Energy Technology Data Exchange (ETDEWEB)

    Remy, J.; Remy-Jardin, M.; Bonnel, F.; Masson, P. [Hopital Calmette, Service de Radiologie, 59 - Lille (France)

    2000-03-01

    The acquisition techniques, including some important dosimetric considerations, and the reconstruction methods reviewing the tomographic, broncho-graphic and endoscopic techniques are first taken into consideration. They are applied to the most usual problems and diseases encountered in the daily activity: pitfalls of interpretation of the tracheobronchial tree; management of hemoptysis; preoperative of proximal bronchial carcinoma; aids and complements to diagnostic and interventional bronchoscopy. The main purpose of this review, which merges the modern technology of spiral (helical) CT with the multislice acquisition in the very near future, consists in delivering, whenever possible, an integrated diagnostic and therapeutic approach of imaging, endoscopy and surgery. (authors)

  14. Detection of colorectal liver metastases: a prospective multicenter trial comparing unenhanced MRI, MnDPDP-enhanced MRI, and spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Bartolozzi, Carlo; Donati, Francescamaria; Cioni, Dania; Lencioni, Riccardo [Department of Radiology, University of Pisa, Via Roma 67, 56100, Pisa (Italy); Procacci, Carlo; Morana, Giovanni [Department of Radiology, University of Verona, Piazzale L.A. Scuro 1, 37134, Verona (Italy); Chiesa, Antonio; Grazioli, Luigi [Department of Radiology, University of Brescia, Piazzale Spedali Civili 1, 25023, Brescia (Italy); Cittadini, Giorgio; Cittadini, Giuseppe [Department of Radiology, University of Genova, Largo R. Benzi 10, 16132, Genova (Italy); Giovagnoni, Andrea [Department of Radiology, University of Ancona, Concam, Torrette, 60020, Ancona (Italy); Gandini, Giovanni; Maass, Jochen [Department of Radiology, University of Torino, Genova 3, 10110, Torino (Italy)

    2004-01-01

    The aim of this study was to compare unenhanced MRI, MnDPDP-enhanced MRI, and spiral CT in the detection of hepatic colorectal metastases. Forty-four patients with hepatic colorectal metastases were examined with unenhanced and MnDPDP-enhanced MRI and with unenhanced and contrast-enhanced spiral CT. The MR examination protocol included baseline T1-weighted spin-echo (SE), T1-weighted gradient-recalled-echo (GRE), and T2-weighted fast-SE sequences; and T1-weighted SE and T1-weighted GRE sequences obtained 30-60 min after administration of 0.5 {mu}mol/kg (0.5 ml/kg) mangafodipir trisodium (MnDPDP). Images were interpreted by three blinded readers. Findings at CT and MRI were compared with those at intraoperative US, which were used as term of reference. Intraoperative US detected 128 metastases. In a lesion-by-lesion analysis, the overall detection rate was 71% (91 of 128) for spiral CT, 72% (92 of 128) for unenhanced MRI, and 90% (115 of 128) for MnDPDP-enhanced MRI. MnDPDP-enhanced MRI was more sensitive than either unenhanced MRI (p<0.0001) or spiral CT (p=0.0007). In a patient-by-patient analysis, agreement with gold standard was higher for MnDPDP-enhanced MRI (33 of 44 cases) than for spiral CT (22 of 44 cases, p=0.0023) and unenhanced MRI (21 of 44 cases, p=0.0013). MnDPDP-enhanced MRI is superior to unenhanced MRI and spiral CT in the detection of hepatic colorectal metastases. (orig.)

  15. Application of spiral CT image 3D reconstruction in severe talar neck fracture

    Institute of Scientific and Technical Information of China (English)

    HE Fei; HUANG He; DENG Ya-min; Wang Bing; ZHANG Chun-qiang; ZHAO Zhi; TANG Xi-zhang; ZHOU Zhao-wen; ZHAO Xue-ling

    2007-01-01

    Objective:To explore the application of the spiral computerized tomography (CT) image three-dimensional(3D ) reconstruction technique associated with the conventional radiography in the diagnosis and treatment of severe talar neck fracture. Methods:Using the multi-slice spiral CT image 3D reconstruction technique,we analysed 11 cases of talar neck fracture.The fractures were reduced and fixed through a minimal incision and internal fixation with titanium cannulated lag screws. Results:In the 11 cases,the results of CT image 3D reconstruction were in concordance with plain radiograph in 6 case of Hawkins type H.And the remaining 5 cases of Hawkins types Ⅲ and Ⅳ could not be classified exactly only by radiographs,one of whom was misdiagnosed.After using the CT image 3D reconstruction,the 5 cases were classified exactly before osteosynthesis.The classifications of these 11 cases were confirmed finally by surgical findings.The duration of operation were 45-140 min,averaging 81min (including the duration of C-arm fluoroscopy).X-ray exposure time was 6-58 seconds,averaging 22 seconds.The blood loss was less than 100 ml.The fracture union was achieved in 3 months. No nonunion, talus avascular necrosis or joint surface collapse occurred.Postoperative follow-up was from 1 to 25 months.According to Hawkins score,excellent result was found in 6 type Ⅱ cases and 1type Ⅲ case;good result in 1 type Ⅲ case with both medial and lateral malleolar fracture,1 type Ⅲ with medial malleolus fractures and 1 open type Ⅲ;fair result in 1 open type Ⅳ with lateral malleolus fracture. Conclusions:By using the multi-slice spiral CT image 3D reconstruction associated with radiography to diagnose and treat severe talar neck fractures,the accuracy of diagnosis can be improved obviously. Based on this technique,more consummate operational plan can be designed and performed so as to achieve a better therapeutic effect.

  16. Dynamics of the Spiral Tip in a Closed Belousov-Zhabotinsky Reaction

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui-Jie; WANG Peng-Ye; ZHAO Ying-Ying

    2005-01-01

    @@ Dynamics of spiral tip rotating in a closed system of the light sensitive Belousov-Zhabotinsky reaction is studied under a homogeneous and steady illumination. The time dependence of the kinematical parameters of meandering spiral is presented and the experimental evidence is obtained for self-synchronization of the spiral tip in a closed B-Z system without external feedback.

  17. Spiral CT features of abdomen after whipple's operation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T. H.; Lee, K. Y.; Shin, K. H.; Jung, M. H.; Park, C. M.; Cha, I. H. [Korea Univ. College of Medicine, Seoul (Korea, Republic of)

    1997-04-01

    To assess the CT features of postoperative anatomical changes, surgical complications, and patterns of tumor recurrence after Whipple's operation. 42 spiral CT scans of 31 patients who had undergone Whipple's operation were retrospectively reviewed. Postoperative diagnoses were distal CBD cancer in 13 patients, cancer of the ampulla of Vater in ten, cancer of the head of the pancreas in seven, and microcystic cystadenocarcinoma of the pancreas in one. Time intervals between surgery and CT ranged from 1 week to 5 years. CT features of postoperative anastomotic changes, surgical complications, and patterns of tumor recurrence were analyzed. Gastro- or duodeno-jejunal anastomosis was seen in 32 CT scans(74%), pancreaticojejunostomy in 27(64%), and choledochojejunostomy in 24(57%). Pneumobilia was seen in ten patients(34%). Abnormal fluid collections in the peripancreatic and perihepatic space were demonstrated in two patients who underwent CT scans within 3 weeks after operation. Other complications included wound abscess(n=2), and portal vein occlusion(n=1). The most common site of metastasis was the lymph node(n=8)(retroperitoneal:n=5; mesentery root:n=4; and celiac:n=2), followed by the liver(n=6), peritoneum(n=3), adrenal gland(n=2), and afferent loop(n=1). In three cases, there was local recurrence in the pancreatic bed. To reduce possible diagnostic errors during CT interpretation, a Knowledge of normal postoperative anatomy, common complications, and patterns of disease recurrence following Whipple's operation is important.

  18. The clinical application of multi-slice spiral CT angiography in abdominal aortic disease

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective: To evaluate the clinical application of multi-slice spiral CT angiography(MSCTA) in the assessment of abdominal aortic disease. Methods: Fifty-four patients underwent multi-slice spiral CT angiography of abdomen. Contrast agent (Omnipaque 300 I g/L) 1.5 ml/kg was injected and the injection rate was 3 ml/s. The delay time was determined by bolus tracking technique,Tll level abdominal aorta was set as the target vessel and the threshold was 180-200 Hu, slice width was 3 mm and with a pitch of 4-6.Original data were transferred to working-station to perform functional reconstruction. Results: Ten cases were normal, twenty-eight cases were abdominal aortic aneurysms, five abdominal aortic dissecting aneurysms (Debakay type Ⅲ ) and eleven aortic sclerosis. SSD showed the body of aneurysm and the relationship between aneurysm and adjacent blood vessel, MIP better displayed calcification of blood vessel wall and condition of the stent, MPR demonstrated true and false lumen, rupture site of abdominal aorta intima and mural thrombus. Conclusion: MSCTA axial and reconstruction image can show the extent of abdominal aortic disease and the relationship with adjacent blood vessels. It is a safe, simple and non-invasive examination method.

  19. Correlation between the Quantifiable Parameters of Whole Solitary Pulmonary Nodules Perfusion Imaging Derived with Dynamic CT and Nodules Size

    Directory of Open Access Journals (Sweden)

    Shiyuan LIU

    2009-05-01

    Full Text Available Background and objective The solitary pulmonary nodules (SPNs is one of the most common findings on chest radiographs. The blood flow patterns of the biggest single SPNs level has been studied. This assessment may be only a limited sample of the entire region of interest (ROI and is unrepresentative of the SPNs as a volume. Ideally, SPNs volume perfusion should be measured. The aim of this study is to evaluate the correlation between the quantifiableparameters of SPNs volume perfusion imaging derived with 16-slice spiral CT and 64-slice spiral CT and nodules size. Methods Sixty-five patients with SPNs (diameter≤3 cm; 42 malignant; 12 active inflammatory; 11 benign underwent multi-location dynamic contrast material-enhanced serial CT scanning mode with stable table were performed; The mean values of valid sections were calculated, as the quantifiable parameters of volume SPNs perfusion imaging derived with16-slice spiral CT and 64-slice spiral CT. The correlation between the quantifiable parameters of SPNs volume perfusion imaging derived with 16-slice spiral CT and 64-slice spiral CT and nodules size were assessed by means of linear regression analysis. Results No significant correlations were found between the nodules size and each of the peak height (PHSPN (32.15 Hu±14.55 Hu,ratio of peak height of the SPN to that of the aorta (SPN-to-A ratio(13.20±6.18%, perfusion(PSPN (29.79±19.12 mLmin-1100 g-1 and mean transit time (12.95±6.53 s (r =0.081, P =0.419; r =0.089, P =0.487; r =0.167, P =0.077; r =0.023, P =0.880. Conclusion No significant correlations were found between the quantifiable parameters of SPNs volume perfusion imaging derived with 16-slice spiral CT and 64-slice spiral CT and nodules size.

  20. Stellar Orbital Studies in Normal Spiral Galaxies II: Restrictions to Structural and Dynamical parameters on Spiral Arms

    CERN Document Server

    Pérez-Villegas, Angeles; Moreno, Edmundo

    2015-01-01

    Making use of a set of detailed potential models for normal spiral galaxies, we analyze the disk stellar orbital dynamics as the structural and dynamical parameters of the spiral arms (mass, pattern speed and pitch angle) are gradually modified. With this comprehensive study of ordered and chaotic behavior, we constructed an assemblage of orbitally supported galactic models and plausible parameters for orbitally self-consistent spiral arms models. We find that, to maintain orbital support for the spiral arms, the spiral arm mass, M$_{sp}$, must decrease with the increase of the pitch angle, $i$; if $i$ is smaller than $\\sim10\\deg$, M$_{sp}$ can be as large as $\\sim7\\%$, $\\sim6\\%$, $\\sim5\\%$ of the disk mass, for Sa, Sb, and Sc galaxies, respectively. If $i$ increases up to $\\sim25\\deg$, the maximum M$_{sp}$ is $\\sim1\\%$ of the disk mass independently in this case of morphological type. For values larger than these limits, spiral arms would likely act as transient features. Regarding the limits posed by extrem...

  1. Malignant focal hepatic lesions complicating underlying liver disease: dual-phase contrast-enhanced spiral CT sensitivity and specificity in orthotopic liver transplant patients

    Energy Technology Data Exchange (ETDEWEB)

    Mortele, K.J. [Dept. of Radiology, University Hospital Gent (Belgium); Department of Radiology, Brigham and Women' s Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115 (United States); De Keukeleire, K. [Dept. of Radiology, University Hospital Gent (Belgium); Praet, M. [Dept. of Pathology, University Hospital Gent, Gent (Belgium); Van Vlierberghe, H. [Dept. of Gastroenterology, University Hospital Gent, Gent (Belgium); Hemptinne, B. de [Dept. of Surgery, University Hospital Gent, Gent (Belgium); Ros, P.R. [Department of Radiology, Brigham and Women' s Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115 (United States)

    2001-09-01

    The aim of this study was to determine the accuracy of contrast-enhanced biphasic spiral CT as a screening tool in the preoperative evaluation of orthotopic liver transplant (OLT) patients. Spiral-CT examinations were performed before liver transplantation in 53 patients. Scans were retrospectively reviewed and compared with pathologic findings in fresh-sectioned livers. When findings between spiral CT and pathology were discordant, formalized livers were reexamined with lesion-by lesion evaluation. Fresh pathologic evaluation revealed 23 liver lesions (16 HCC, 7 macro-regenerative nodules). Malignancy was identified in 13 of 53 patients (24.5%). Pre-transplantation spiral CT depicted 27 liver lesions (23 HCC, 4 macro-regenerative nodules). Malignancy was suspected in 14 patients (26.4%). In 10 of 53 (18.9%), spiral CT and pathologic evaluation were discordant. Subsequent retrospective pathologic evaluation showed malignancy in 4 additional patients. Spiral CT compared with the retrospective pathologic findings revealed 36 real-negative, 14 real-positive, 0 false-positive, and 3 false-negative patients with malignancy. Sensitivity and specificity of spiral CT in detection of malignancy was 82 and 100%, respectively. Contrast-enhanced biphasic spiral CT is an accurate technique in the evaluation of patients preceding OLT. Routine fresh-sectioned liver pathologic findings are not as sensitive as previously estimated. (orig.)

  2. Frequency of benign hepatic lesions incidentally detected with contrast-enhanced thin-section portal venous phase spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Voelk, M.; Strotzer, M.; Lenhart, M.; Techert, J.; Seitz, J.; Feuerbach, S. [Univ. Hospital, Regensburg (Germany). Dept. of Diagnostic Radiology

    2001-03-01

    To evaluate the frequency of benign focal hepatic lesions incidentally detected at contrast-enhanced thin-section portal venous phase spiral CT. Material and methods: Between January 1998 and February 1999, contrast-enhanced hepatic spiral CT examinations were performed in 1,892 patients. Out of these, only 100 patients fulfilled the following inclusion criteria: No underlying malignant disease, no liver cirrhosis, no suspected or known focal liver lesions. Standardized spiral CT parameters were applied. All CT studies were reviewed retrospectively by one radiologist. Any focal lesion was recorded and classified. Lesion size and number were noted. Results: A total of 108 hepatic lesions were reported in 33 out of 100 patients (80 cysts; 18 hemangiomas; 3 focal fatty infiltrations; 2 focal non-tumorous perfusion defects; 1 calcification; and 4 non-classified lesions). The average lesion size was 9.4 mm (5 mm: n=40; 6-10 mm: n=30; 11-15 mm: n=28; >15 mm: n=10). Conclusion: Benign liver lesions are probably a frequent incidental finding at abdominal spiral CT.

  3. Spiral hydro-CT of the pancreas in the thin-slice method; Hydrospiral-CT des Pankreas in Duennschichttechnik

    Energy Technology Data Exchange (ETDEWEB)

    Richter, G.M. [Abt. fuer Radiodiagnostik, Radiologische Universitaetsklinik Heidelberg (Germany); Simon, C. [Abt. fuer Radiodiagnostik, Radiologische Universitaetsklinik Heidelberg (Germany)]|[Abt. Allgemeine Chirurgie, Chirurgische Universitaetsklinik Heidelberg (Germany); Hoffmann, V. [Abt. fuer Radiodiagnostik, Radiologische Universitaetsklinik Heidelberg (Germany); DeBernardinis, M. [Abt. fuer Radiodiagnostik, Radiologische Universitaetsklinik Heidelberg (Germany); Seelos, R. [Abt. Allgemeine Chirurgie, Chirurgische Universitaetsklinik Heidelberg (Germany); Senninger, N. [Abt. Allgemeine Chirurgie, Chirurgische Universitaetsklinik Heidelberg (Germany); Kauffmann, G.W. [Abt. fuer Radiodiagnostik, Radiologische Universitaetsklinik Heidelberg (Germany)

    1996-05-01

    In an open prospective study, 151 patients with a suspected pancreatic neoplasm based on clinical, laboratory or other imaging data were examined between May 94 and October 95. Our newly developed Hydro-CT methodology included intravenous injection of 40 mg N-butylscopolaminium bromide (Buscopan) for intestinal paralysis, gastric and duodenal wall distension by oral administration of an average of 1.5 l warm tap water, 30 RAO patient positioning, an individualized contrast injection technique as determined beforehand by time-to-peak measurement in the portal vein and thin-slice spiral CT (3 mm increment, 6 mm table feed and 3 mm secondary reconstruction). A detailed evaluation form was used to assess (1) tumor detection rate, (2) differentiation of malignant versus benign disease, (3) differential diagnosis, and (4) accuracy of assessment of resectability by identification of infiltration into adjacent organs and vessel structures relevant for resectability such as splenic, superior mesenteric, portal vein and celiac trunk, superior mesenteric, splenic and hepatic arteries. As the gold standard for positive tumor detection surgery and microscopic diagnosis were used, and for negative tumor detection an event-free survival of 6 months. Almost all examinations were well tolerated. In only 4% was on-site administration of a gastric tube required because of vomiting. In 2% of the patients a slight allergic reaction to be contrast medium was seen. The prevalence of a pancreatic neoplasm was 38%. In tumor detection Hydro-CT reached an overall accuracy of 97.4% with a sensitivity of 100% and a specificity of 95.9%. In the differentiation of benign versus malignant disease Hydro-CT reached an overall accuracy of 89.7% with a sensitivity of 92.5% and a specificity of 83.3%. The prevalence of a pancreatic carcinoma was 24%; 4% other malignant tumors were found (distal common bile duct carcinoma, cystadenocarcinoma). (orig./MG) [Deutsch] Von Mai 1994 bis Oktober 1995 wurden

  4. Spiral Dynamics of Consciousness. Possibilities of Use by Collective Managers

    Directory of Open Access Journals (Sweden)

    Doronin Andrii V.

    2014-03-01

    Full Text Available The goal of the article is showing a possibility of solution of the problem of reduction of human efficiency in the information society by means of growth of psychological load. Methodological grounds of the study are ideas of the American psychologist Clare William Graves, who, while developing the Abraham Maslow theory, created a system theory of evolution development of human consciousness, which determines human behaviour. Based of systemisation of conclusions of C. Graves and his followers the article formulates a hypothesis about expediency of use of spiral dynamics ideas for identifying reserves of strengthening of influence of the collective manager upon labour behaviour of subordinates. Test of hypothesis shows that, apart from diagnostics of the sources of activation of individual labour behaviour, the theory of spiral dynamics allows identification of reserves of formation of collective consciousness and solidary labour force of a creative collective. Their use creates a basis of intensification of processes of intellectualisation of the organisation capital. In order to ensure these changes it is necessary to find mechanisms of changing external environment, which sets principally new tasks and requires principally new strategies of their solution.

  5. Tumor angiogenesis and dynamic CT in colorectal carcinoma: Radiologic-pathologic correlation

    Institute of Scientific and Technical Information of China (English)

    Zi-Ping Li; Quan-Fei Meng; Can-Hui Sun; Da-Sheng Xu; Miao Fan; Xu-Feng Yang; Dong-Ying Chen

    2005-01-01

    AIM: To investigate the correlation between microvessel density and spiral CT perfusion imaging in colorectal carcinoma.METHODS: Thirty-seven patients, with histologically proven colorectal carcinoma, underwent water enema spiral CT scan. The largest axial surface of the primary tumor was searched on unenhanced spiral CT images. At this level, the enhanced dynamic scan series was acquired.Time-density curves (TDC) were created from the region of interest drawn over the tumor, target artery by Toshiba Xpress/SX spiral CT with perfusion functional software.Then the perfusion was calculated. Microvessel density(MVD) was evaluated using immunohistochemical staining of surgical specimens with anti-CD34, and then MVD was correlated with perfusion.RESULTS: MVD of colorectal carcinomas was 33.11-173.44,mean 87.28, and perfusion was 15.60-64.80 mL/min/100 g, mean 39.74 mL/min/100 g. MVD and perfusionwere not associated with invasive depth, metastasis and disease stage, and they all decreased with increasing Dukes' stage, but no significant correlation was found between them (r= 0.L8, P = 0.29).CONCLUSION: There is no significant correlation between MVD and perfusion. Neovascularizaton and perfusion are highly presented in early colorectal carcinoma.CT perfusion imaging may be more suited for assessing tumorigenesis in colorectal carcinoma than histological MVD technique.

  6. Solitons in spiraling systems: a continuum model for dynamical phyllotaxis

    Energy Technology Data Exchange (ETDEWEB)

    Nisoli, Cristiano [Los Alamos National Laboratory

    2009-01-01

    A novel, protean, topological soliton has been shown to emerge in systems of repulsive particles in cylindrical geometries, whose statics is described by the number-theoretical objects of Phyllotaxis. We present a minimal and local continuum model that can explain many of the features of the phyllotactic soliton, such as speed, screw shift, energy transport and, for Wigner crystal on a nanotube, charge. The treatment applies just as well in general to solitons in spiraling systems. Unlike e.g. Sine-Gornon-like solitons, our soliton can exist between non degenerate structure, implies a power flow through the system, dynamics of the domains it separates, and possesses pulses, both static and dynamic. Its applications include from charge transfer in Wigner Crystals on nanotubes or A to B-DNA transitions.

  7. Dynamic CT features of hepatic abscesses

    Institute of Scientific and Technical Information of China (English)

    ZOU Li-guang; CHEN Ken; LI Yan-yu; YI Xi-zhi

    2002-01-01

    Objective: To investigate the features of hepatic abscess by dynamic contrast-enhanced CT. Methods: CT films of 62 cases of hepatic abscesses were reviewed retrospectively. All the patients underwent both plain and enhanced CT scanning, and 23 of them received dynamic CT examination. Results: The dynamic phase (60~90 s), the enhancement patterns of the abscesses varied from the ring enhancement of the abscess diminished in which the hypodense ring enhanced and became isodense, or the abscess enhanced diffusely and became smaller, the colliquative necrosis area more obvious. Conclusion: Contrast enhanced CT should be used routinely in the evaluation of hepatic abscesses. The dynamic and delayed scan is necessary to diagnose atypical hepatic abscesses.

  8. Clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ximing [Tianjin Medical University, Tianjin City (China) and Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China)], E-mail: wxming369@163.com.cn; Wu Lebin [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Sun Cong [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Shandong University Medical College, Shandong Jinan 250012 (China); Liu Cheng [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Chao, Bao-Ting [Shandong University Medical College, Shandong Jinan 250012 (China); Han Bo [Shandong Provincial Hospital Pediatric Department, Shandong, Jinan 250021 (China); Zhang Yunting [Tianjin Medical University, General Hospital MR Department, Tianjin City (China); Chen Haisong [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Shandong University Medical College, Shandong Jinan 250012 (China); Li Zhenjia [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China)

    2007-11-15

    Objective: To explore the clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot. Methods: Eighteen patients with diagnosed Tetralogy of Fallot underwent cardiac CT angiography with 64-slice CT (CTA). Two- and three-dimensional images were used for diagnosing in all cases by means of MPR (coronal, sagital and oblique), cMPR, MIP and VRT. Results: All patients had ventricular septal defect, pulmonary stenosis and hypertrophy of right ventricle. The morphologic features of Tetralogy of Fallot were equal to echocardiography. Patent ductus arteriosus (PDA) were detected on eight patients. Main coronary artery branches and partial sub-branches were visualized in all patients. Abnormal coronary arteries were found in seven cases: both left and right main coronary artery arising from the right aortic sinus one case, right main coronary artery and circumflex (CX) arising from the right aortic sinus one case, left anterior descending (LAD) and CX arising from left aortic sinus directly one case, left and right coronary artery arising from back and front of the aortic sinus, respectively, three cases. Pulmonary artery branch stenosis was found in 12 cases and branch pulmonary artery dilation noticed in 1 case. Double superior vena cava was also found in one case. According to the surgery the diagnostic accuracy of CT and Echocardiography was 95.45 and 83.33%, respectively. Conclusion: Two- and three-dimensional 64-slice CTA not only show the overall anatomical structure of the heart, but also show coronary and pulmonary arteries. With these results, evaluation of coronary anomalies and pulmonary artery stenosis with 64-MSCT is extremely valuable for planning the operative procedure on the patients with Tetralogy of Fallot.

  9. Experimental Study of Multi-slice Spiral CT Perfusion Imaging in VX2 Soft-tissue Tumor of Rabbits

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jingfeng; WANG Renfa; WANG Min; LI Yonggang; YANG Haitao

    2006-01-01

    An experimental animal model of malignant soft-tissue tumor was established to investigate the applied value of multi-slice spiral CT perfusion imaging preliminarily. Ten New Zealand white rabbits which were implanted with VX2 tumor in either proximal thigh were subjected to CT plain scan and perfusion scan two weeks later respectively, then the original perfusion images were transmitted to AW4.0 Workstation. The functional maps and perfusion parameters including blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS) were computed and analyzed. All the values of BF, BV and PS in VX2 soft-tissue tumors were obviously higher while the MTT-values were lower than those in the normal muscular tissues significantly. It was suggested that multi-slice spiral CT perfusion imaging is an accurate, convenient and relatively safe functional imaging technique, and can give a quantitative assessment to angiogenesis and blood perfusion of soft-tissue tumors.

  10. Clinical values of CT and dynamic CT in brain infarction

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Soo Il; Jang, Do; Seo, Eun Joo; Sohn, Myung Hee; Choi, Ki Chul [Chonbuk National University College of Medicine, Jeonju (Korea, Republic of)

    1985-04-15

    With the advent of faster scan time and new computer program, a scanning technique called 'dynamic computed tomography' has become possible. Dynamic computed tomography consisted of performing multiple rapid sequence scans after injection of contrast material. The authors have evaluated the clinical usefulness of computed tomography and dynamic computed tomography of 93 patients with brain infarction and/or ischemia during the period of 17 months from April 1983 to August 1984 in Department of Radiology, Chonbuk National University Hospital. The results were as follows; 1. The age distribution ranged from 18 years to 78 years. Among them the most common age group was between 50 years and 59 years (40.9%). 2. The sites of brain infarction were cerebral lobes (63 cases,68), basal ganglia (15 cases, 16.1%) and multiple sites (6 cases, 6.4%). The common affected site was middle cerebral artery territories. 3. The contrast enhancement of acute infarction was noted in 14 cases (17.5%) which occurred commonly between 3 days and 2 weeks from ictus. 4. The patterns of time-density curve in brain infarction and/or ischemia were as follow: a. Depression of slow wash-in phase was 20 cases (59%). b. Lower peak concentration was 17 cases (50%). c. Lower and delayed peak concentration was 7 cases (21%). d. No definite peak concentration was 6 cases (18%). First three patterns of time-density curve were thought as relatively characteristic curve of brain infarction and/or ischemia. 5. Two cases that showed negative findings on precontrast CT scan appeared to be positive findings as hypodensity on postcontrast CT scan and were confirmed as brain infarction by dynamic CT. 6. The diagnostic entity of dynamic CT scan were as follows; a. large artery thrombotic infarction were 23 cases (58%). b. lacnar infarction were 6 cases (15%). c. ischemia were 5 cases (13%). d. normal were 5 cases (13%). In six cases of lacunar infarction which was double hypodensity on pre

  11. Staging of colorectal carcinoma by spiral CT with water enema : correlation with pathologic staging using new AJCC classification

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyoung Jung; Lee, Dong Ho; Ko, Young Tae [Kyunghee Univ. Hospital, Seoul (Korea, Republic of)

    1999-05-01

    In cases of colorectal cancer, to correlate the spiral CT staging with water enema with the pathologic staging according to the new AJCC classification. Ninety four patients with pathologically proven carcinoma of the colon who had undergone spiral CT with water enema were evaluated. CT scans were obtained after enema involving about 600-1,200mL of water. Scanning was performed from the diaphragmatic dome to the symphysis pubis using 10mm collimation thickness, 12mm table feed, and 10mm reconstruction interval. The TNM stage, as seen on spiral CT, was determined without reference to the pathologic results. Staging was performed according to the new AJCC cancer staging manual(1997). The pathologic T-stage was T1 in four cases(4.3%), T2 in 11(11.7%), T3 in 72(76.6%), and T4 in seven(7.4%). The pathologic N-stage was N0 in 57 cases(60.6%), N1 in 25 cases(26.6%), and N2 in 12(12.8%). The pathologic M-stage was M0 in 90 cases(95.7%) and M1 in four(4.3%). The detection rate of colon cancer using spiral CT with water enema was 97.9%. At the T-stage, pathologic correlation was good in 68.1% of cases(64/94). Nine patients(9.6%) were overstaged and 21(22.3%) were understaged. At the N-stage, pathologic correlation was good in 54.3% of cases(51/94), with 27 patients(28.7%) overstaged and sixteen(17.0%) understaged. At the M-stage, pathologic correlation was good in 95.7% of cases(90/94). Four patients(4.3%) were overstaged. The accuracy of staging of colorectal carcinoma by spiral hydro-CT was 68.1% at the T-stage, 54.3% at the N-stage, and 95.7% at the M-stage. As seen on spiral CT with water enema, the T-stage tended to wards understaging and the N-stage towards overstaging.

  12. The effect of pitch in multislice spiral/helical CT; L'effet du pas dans la tomodensitometrie spiralee/helicoidale multidetecteurs

    Energy Technology Data Exchange (ETDEWEB)

    Wang, G.; Vannier, M.W. [Iowa Univ., Dept. of Radiology, Iowa City, IA (United States)

    2000-07-01

    The purpose of this study is to understand the effect of pitch on raw data interpolation in multislice spiral/helical computed tomography (CT) and provide guidelines for scanner design and protocol optimization. Multislice spiral CT is mainly characterized by the three parameters: the number of detector arrays, the detector collimation, and the table increment per x-ray source rotation. The pitch in multislice spiral CT is defined as the ratio of the table increment over the detector collimation in this study. In parallel to the current framework for studying longitudinal image resolution, the central fan-beam rays of direct and opposite directions are considered, assuming a narrow cone-beam angle. Generally speaking, sampling in the Radon domain by the direct and opposite central rays is nonuniform along the longitudinal axis. Using a recently developed methodology for quantifying the sensibility of signal reconstruction from non-uniformly sampled finite points, the effect of pitch on raw data interpolation is analyzed in multislice spiral CT. Unlike single-slice spiral CT, in which image quality decreases monotonically as the pitch increases, the sensibility of raw data interpolation in multislice spiral CT increases, suggesting that image quality does not decrease monotonically in this case. The most favorable pitch can be found from the sensitivity-slice spiral CT is provided. The study on the effect of pitch using the sensitivity analysis approach reveals the fundamental characteristics of raw data interpolation in multislice spiral CT, and gives insights into interaction between pitch and image quality. These results may be valuable for design of multislice spiral CT scanners and imaging protocol optimization in clinical applications. (authors)

  13. [Diagnostic values of bronchoscopy and multi-slice spiral CT for congenital dysplasia of the respiratory system in infants: a comparative study].

    Science.gov (United States)

    Wang, Xing-Lu; Huang, Ying; Li, Qu-Bei; Dai, Ji-Hong

    2013-09-01

    To investigate and compare the diagnostic values of bronchoscopy and multi-slice spiral computed tomography (CT) for congenital dysplasia of the respiratory system in infants. Analysis was performed on the clinical data, bronchoscopic findings and multi-slice spiral CT findings of 319 infants (≤1 years old) who underwent bronchoscopy and/or multi-slice spiral CT and were diagnosed with congenital dysplasia of the respiratory system. A total of 476 cases of congenital dysplasia of the respiratory system were found in the 319 infants, including primary dysplasia of the respiratory system (392 cases) and compressive dysplasia of the respiratory system (84 cases). Of the 392 cases of primary dysplasia of the respiratory system, 225 (57.4%) were diagnosed by bronchoscopy versus 167 (42.6%) by multi-slice spiral CT. There were significant differences in etiological diagnosis between bronchoscopy and multi-slice spiral CT in infants with congenital dysplasia of the respiratory system (Pdysplasia of the respiratory system caused by tracheobronchomalacia were diagnosed by bronchoscopy and all 17 cases of primary dysplasia of the respiratory system caused by lung tissue dysplasia were diagnosed by multi-slice spiral CT. Of the 84 cases of compressive dysplasia of the respiratory system, 74 cases were diagnosed by multi-slice spiral CT and only 10 cases were diagnosed by bronchoscopy. Compared with multi-slice spiral CT, bronchoscopy can detect primary dysplasia of the respiratory system more directly. Bronchoscopy is valuable in the confirmed diagnosis of tracheobronchomalacia. Multi-slice spiral CT has a higher diagnostic value for lung tissue dysplasia than bronchoscopy.

  14. Diagnostic value of 64-slice spiral CT angiography in the diagnosis of multiple intracranial aneurysms: a report of 25 cases

    Directory of Open Access Journals (Sweden)

    Hong-sheng WANG

    2013-02-01

    Full Text Available Objective  To evaluate the diagnostic value of 64-slice spiral CT angiography (CTA in multiple intracranial aneurysms (MIA. Methods  Twenty-five patients (9 males and 16 females, aged from 17 to 68 years with suspected MIA underwent 64-slice spiral CTA with slice thickness of 0.625mm. The data of all patients were reconstructed with multiplanar reconstruction (MPR, 3-dimensional shade surface display (3-SSD, volume rendering (VR and maximum intensity projection (MIP. The clinical diagnostic value was evaluated with the results of surgery or interventional embolization therapy. Results  A total of 61 aneurysms were detected by 64-slice spiral CTA in 25 patients, among them 17 patients were with 2 aneurysms, 6 patients with 3 aneurysms, 1 patient with 4 aneurysms and 1 patient with 5 aneurysms. The 64-slice spiral CTA could not only clearly demonstrate MIA, but also the size, neck, axis point and parent artery of each aneurysm, and the spatial relationship between aneurysm and the adjacent vessels and bone structures. Twenty-one patients underwent microsurgery and four underwent embolization, the location, size and shape of aneurysm and its spatial relationship with adjacent structures were in accordance with the findings of 64-slice spiral CTA. Conclusion  The 64-slice spiral CTA could be used as the first choice in the diagnosis of MIA for its high accuracy, and may be an important adjunct to digital subtraction angiography (DSA in MIA treatment.

  15. Role of curved planar reformations using multidetector spiral CT in diagnosis of pancreatic and peripancreatic diseases

    Institute of Scientific and Technical Information of China (English)

    Jing-Shan Gong; Jian-Min Xu

    2004-01-01

    AIM: To investigate the role of curved planar reformations using multidetector spiral CT (MSCT) in diagnosis of pancreatic and peripancreatic diseases.METHODS: From October 2001 to September 2003, 47consecutive patients with pancreatic or peripancreatic diseases, which were confirmed by operation, endoscopic retrograde cholangiopancreatography and clinical follow-up,were enrolled in this study. CT scanning was performed at a MSCT with four rows of detector. A set of images with an effective thickness of 1.0-2.0 mm and a gap of 0.5-1.0 mm(50% overlap) were acquired in all patients for postprocessing. Curved planar reformations were carried out by drawing a curved line on transverse source images, coronal or sagittal multiplanar reformations according to certain anatomic structures (such as cholangiopancreatic ducts or peripancreatic vessels) and the position of lesion.RESULTS: With thin collimation, MSCT could acquire highquality curved planar reformations to display the profile of the whole pancreas, to trace the cholangiopancreatic ducts and peripancreatic vessels, and to show the relationship of lesions with pancreas and peripancreatic anatomic structures in one curved plane, which facilitates diagnosis and rapid communication of diagnostic information with referring physicians.CONCLUSION: MSCT with thin collimation could be used to create high-quality curved planar reformations in evaluating pancreatic and peripancreatic diseases with pertinent anatomic information and relative pathologic signs to facilitate the diagnosis and enhance communication with the referring physician. Curved planar reformations can serve as supplements for transverse images in diagnosis and management of pancreatic and peripancreatic diseases.

  16. TRIPLE PHASE SPIRAL C.T. IN THE EVALUATION OF HEPATIC MASSES

    Directory of Open Access Journals (Sweden)

    Prasad

    2015-10-01

    Full Text Available BACKGROUND AND OBJECTIVE : The goal of the study is to determine the value of various phases of Triple, Helical CT, Hepatic arterial Phase (HAP, Portal venous phase (PVP and Equilibrium Phase (EP, is the detection and characterization of Hepatic Lesions and to evaluate whether u nenhanced and hepatic arterial phases when used in conjunction with porto venous phase would lead to detection of greater number of lesions or better characterization of lesion. METHODOLOGY : The study population consists of 50 Patients aged between 30 Years and 80 Years were examined with multiphase (plain, hepatic arterial, portal venous and equilibrium phases. Spiral CT of liver. Patients were referred for CT scan when liver diseases were suspected clinically, if ultrasound and other previous investi gations revealed lesions which had to be further evaluated by spiral CT and to detect liver metastases in known cases of primary extra hepatic malignancy. CT TECHNIQUE: Helical scanning of liver with Toshiba astein s4, continuous spiral run and the images were reconstructed at 5mm intervals. Contrast material 100ml was injected through 18 or 20G catheter at the rate of 3ml per second using automatic medrad power injector. Non - ionic contrast [IOHEXOl – 300mg perml was used in all the patients]. After obtaine d unenhanced CT scan HAP scanning was initiated 25 seconds after initiation of contrast injection. Portal venous phase scanning was initiated 60 - 65 seconds after start of contrast injection. Equilibrium phase scanning was initiated after 180 seconds after the start of contrast injection. IMAGE EVALUATION: All the images of 4 phases were reviewed. First Step : The presence, appearance and enhancement of each Lesion were noted in all phases and lesion were described Isodense, Hypodense Hyperdense based on thei r attenuation relative to liver parenchyma during that phase of scanning. Based on enhancement pattern of the lesion during various phases they were

  17. 3D imaging with an isocentric mobile C-arm. Comparison of image quality with spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Kotsianos, Dorothea; Wirth, Stefan; Fischer, Tanja; Euler, Ekkehard; Rock, Clemens; Linsenmaier, Ulrich; Pfeifer, Klaus Juergen; Reiser, Maximilian [Departments of Radiology and Surgery, Klinikum der Universitaet Muenchen, Innenstadt, Nussbaumstrasse 20, 80336, Munchen (Germany)

    2004-09-01

    The purpose of this study was to evaluate the image quality of the new 3D imaging system (ISO-C-3D) for osteosyntheses of tibial condylar fractures in comparison with spiral CT (CT). Sixteen human cadaveric knees were examined with a C-arm 3D imaging system and spiral computed tomography. Various screws and plates of steel and titanium were used for osteosynthesis in these specimens. Image quality and clinical value of multiplanar (MP) reformatting of both methods were analyzed. In addition, five patients with tibial condylar fractures were examined for diagnosis and intra-operative control. The image quality of the C-arm 3D imaging system in the cadaveric study was rated as significantly worse than that of spiral CT with and without prostheses. After implantation of prostheses an increased incidence of artifacts was observed, but the diagnostic accuracy was not affected. Titanium implants caused the smallest number of artifacts. The image quality of ISO-C is inferior to CT, and metal artifacts were more prominent, but the clinical value was equal. ISO-C-3D can be useful in planning operative reconstructions and can verify the reconstruction of articular surfaces and the position of implants with diagnostic image quality. (orig.)

  18. 螺旋CT对胃癌的诊断价值%The diagnostic value of spiral CT in gastric cancer

    Institute of Scientific and Technical Information of China (English)

    徐江; 刘珍友

    2015-01-01

    目的:分析胃癌的螺旋CT表现,并评价螺旋CT对胃癌的诊断能力。方法收集19例经胃镜活检或手术病理证实的胃癌病例,分析其螺旋CT表现。结果螺旋CT能清楚地观察胃癌病变的全貌、病变与周围脏器的关系,但对胃癌的定性方面有一定的局限性。结论螺旋 CT检查可首先发现胃部病变,如结合钡餐、纤维胃镜,能为临床治疗提供可靠的价值。%Objective To analyze the CT findings of stomach cancer and to evaluate its diagnostic ability. Methods Collection of 19 cases by endoscopic biopsy or surgical pathology confirmed cases of gastric cancer. The spiral CT features of stomach cancer were analyzed retrospectively. Results Although the limitation in the diagnosis of GASTRIC cancer, spiral CT shows a clearly revealed outline of gastric cancer lesions and the relationship between the lesions and surrounding organs. Conclusion Spiral CT examination may first discovered gastric cancer and can provide reliable basis for clinical treatment by combining barium meal and fiberoptic endoscope.

  19. 3D imaging with an isocentric mobile C-arm comparison of image quality with spiral CT.

    Science.gov (United States)

    Kotsianos, Dorothea; Wirth, Stefan; Fischer, Tanja; Euler, Ekkehard; Rock, Clemens; Linsenmaier, Ulrich; Pfeifer, Klaus Jürgen; Reiser, Maximilian

    2004-09-01

    The purpose of this study was to evaluate the image quality of the new 3D imaging system (ISO-C-3D) for osteosyntheses of tibial condylar fractures in comparison with spiral CT (CT). Sixteen human cadaveric knees were examined with a C-arm 3D imaging system and spiral computed tomography. Various screws and plates of steel and titanium were used for osteosynthesis in these specimens. Image quality and clinical value of multiplanar (MP) reformatting of both methods were analyzed. In addition, five patients with tibial condylar fractures were examined for diagnosis and intra-operative control. The image quality of the C-arm 3D imaging system in the cadaveric study was rated as significantly worse than that of spiral CT with and without prostheses. After implantation of prostheses an increased incidence of artifacts was observed, but the diagnostic accuracy was not affected. Titanium implants caused the smallest number of artifacts. The image quality of ISO-C is inferior to CT, and metal artifacts were more prominent, but the clinical value was equal. ISO-C-3D can be useful in planning operative reconstructions and can verify the reconstruction of articular surfaces and the position of implants with diagnostic image quality.

  20. Multi-slice spiral CT of aortocoronary grafts and internal mammary artery bypasses: Assessment of bypasses and their anastomoses; Mehrzeilen-Spiral-CT von aortokoronaren Venenbypaessen und Mammaria-interna-Bypaessen: Beurteilung der Bypaesse und ihrer Anastomosen

    Energy Technology Data Exchange (ETDEWEB)

    Froehner, S.; Wagner, M.; Schmitt, R.; Christopoulos, G.; Coblenz, G. [Inst. fuer Diagnostische und Interventionelle Radiologie, Herz- und Gefaessklinik GmbH, Bad Neustadt an der Saale (Germany); Brunn, J.; Mueller, M.; Kerber, S. [Fachbereich Kardiologie, Herz- und Gefaessklinik GmbH, Bad Neustadt an der Saale (Germany); Urbanski, P. [Klinik fuer Herzchirurgie, Herz- und Gefaessklinik GmbH, Bad Neustadt an der Saale (Germany)

    2002-07-01

    Objective: To assess aortocoronary grafts and internal mammary artery bypasses by means of EKG-triggered contrast-enhanced multi-slice spiral CT, and to evaluate the diagnostic accuracy of this new imaging modality. Material and methods: 59 patients with up to 5 aortocoronary grafts and/or internal mammary artery bypasses per patient were examined with regard to bypass morphology, the free passage, and the proximal as well as the distal anastomoses using multi-slice computed tomography. Axial source images were calculated by means of retrospective triggering at different diastolic delay times, and were postprocessed in several planes with the multiplanar volume reconstruction (MPVR) software. Results: On the pre-condition that data sets were acquired at sinus rhythm and at a heart rate lower than 65/min, aortocoronary grafts and internal mammary artery bypasses could be depicted in adequate diagnostic quality in about 80% of all cases with contrast-enhanced multi-slice spiral CT. Both, the free passage of the bypasses as well as the morphology of the proximal anastomoses were sufficiently assessed with multiplanar volume reconstruction (MPVR), whereas the distal anastomoses couldn't be depicted sufficiently in 20% of all cases. Conclusion: As a non-invasive method, contrast-enhanced and ECG-triggered multi-slice spiral computed tomography has gained diagnostic potential for the accurate visualization of aortocoronary grafts and the internal mammary artery bypasses. (orig.) [German] Ziel: Die vorliegende Arbeit stellt die Moeglichkeiten der kontrastmittelverstaerkten, EKG-getriggerten Mehrzeilen-Computertomographie in der Beurteilung von aortokoronaren Venenbypaessen und Mammaria-interna-Bypaessen dar. Material und Methode: Bei 59 Patienten mit 1 bis 5 aortokoronaren Venen-Bypaessen bzw. Mammaria-interna-Bypaessen wurden deren Morphologie, Durchgaengigkeit, die proximalen Anastomosen und die distalen Insertionsstellen mittels Mehrzeilen-Spiral-CT untersucht

  1. A spiral galaxy's mass distribution uncovered through lensing and dynamics

    CERN Document Server

    Trick, Wilma H; Dutton, Aaron A

    2016-01-01

    We investigate the matter distribution of a spiral galaxy with a counter-rotating stellar core, SDSS J1331+3628 (J1331), independently with gravitational lensing and stellar dynamical modelling. By fitting a gravitational potential model to a quadruplet of lensing images around J1331's bulge, we tightly constrain the mass inside the Einstein radius R_ein = (0.91 +/- 0.02)'' (~= 1.83 +/- 0.04 kpc) to within 4%: M_ein = (7.8 +/- 0.3) x 10^10 M_Sun. We model observed long-slit major axis stellar kinematics in J1331's central regions by finding Multi-Gaussian Expansion (MGE) models for the stellar and dark matter distribution that solve the axisymmetric Jeans equations. The lens and dynamical model are independently derived, but in very good agreement with each other around ~R_ein. We find that J1331's center requires a steep total mass-to-light ratio gradient. A dynamical model including an NFW halo (with virial velocity v_200 ~= 240 +/- 40 km/s and concentration c_200 ~= 8 +/- 2) and moderate tangential velocit...

  2. Cine CT technique for dynamic airway studies

    Energy Technology Data Exchange (ETDEWEB)

    Ell, S.R.; Jolles, H.; Keyes, W.D.; Galvin, J.R.

    1985-07-01

    The advent of cine CT scanning with its 50-msec data acquisition time promises a much wider range of dynamic CT studies. The authors describe a method for dynamic evaluation of the extrathoracic airway, which they believe has considerable potential application in nonfixed upper-airway disease, such as sleep apnea and stridor of unknown cause. Conventional CT is limited in such studies by long data acquisition time and can be used to study only prolonged maneuvers such as phonation. Fluoroscopy and digital subtraction studies are limited by relatively high radiation dose and inability to image all wall motions simultaneously.

  3. Nonlinear dynamics of breathers in the spiral structures of magnets

    Energy Technology Data Exchange (ETDEWEB)

    Kiselev, V. V., E-mail: kiselev@imp.uran.ru; Raskovalov, A. A. [Russian Academy of Sciences, Mikheev Institute of Metal Physics, Ural Branch (Russian Federation)

    2016-06-15

    The structure and properties of pulsating solitons (breathers) in the spiral structures of magnets are analyzed within the sine-Gordon model. The breather core pulsations are shown to be accompanied by local shifts and oscillations of the spiral structure with the formation of “precursors” and “tails” in the moving soliton. The possibilities for the observation and excitation of breathers in the spiral structures of magnets and multiferroics are discussed.

  4. Transient inhomogeneous contrast enhancement of the spleen on arterial phase of spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taik Kun; Kang, Hyo Jun; Lee, Ki Yeol; Park, Cheol Min; Chung, Kyoo Byung [Korea Univ. College of Medicine, Seoul (Korea, Republic of)

    1997-02-01

    To assess the relationship between splenic transient inhomogeneous contrast enhancement(CE) on the arterial phase of spiral CT, and splenic volume, and to classify the CE pattern in liver cirrhosis. We measured the splenic volume of 120 patients, 60 showed inhomogeneous splenic CE on arterial phase, and 60 showed homogeneous splenic CE. CT scans with intrinsic splenic pathology were excluded. Sixteen patients with clinically confirmed liver cirrhosis were included. Splenic volumes of the inhomogeneous and homogeneous CE group were compared. The inhomogeneous group was divided into grades according to areas of non-enhanced portion (grade 1, focal geographic; grade 2, multifocal patchy; grade 3, extensive serpentine inhomogeneous CE), and these were correlated with splenic volume. Among the 60 inhomogeneous CE scans, 23 cases (38.3%) showed splenomegaly (spleen volume > 220cm{sup 3}); in contrast, this applied to only 8 cases (13.3%) of the 60 homogeneous CE scans. Mean splenic volume in the inhomogeneous CE group (226.74 {+-} 129.78cm{sup 3}) was greater than in the homogeneous CE group (184.56 {+-} 77.44cm{sup 3}) (p < 0.033). A larger splenic volume and extensive inhomogeneous CE (grade 3) were noted, and most liver cirrhosis patients(14/16) were grade 3. Three such patients who had shown inhomogeneous splenic CE on arterial phase showed inhomogeneous CE even on portal phase. Inhomogeneous splenic CE on arterial phase was more common in cases of an enlarged spleen, and more extensive in liver cirrhosis. These findings suggest hemodynamic change of the spleen may be a contributory factor.

  5. [Detection of coronary calcifications by electron beam tomography and multislice spiral CT: clinical relevance].

    Science.gov (United States)

    Achenbach, S; Schmermund, A; Erbel, R; Silber, S; Haberl, R; Moshage, W; Daniel, W G

    2003-11-01

    Coronary calcifications can be detected and quantified using electron beam tomography (EBT) or newer generation multi-slice spiral CT (MSCT) scanners. An abundance of data has been acquired by EBT. It could be shown that the amount of coronary calcium correlates to the coronary plaque burden. The detection of coronary calcium with CT imaging methods therefore provides a unique opportunity to detect and quantify coronary atherosclerosis in a subclinical stage. Consequently, the presence and amount of coronary calcium has been shown to be indicative for an increased coronary event risk in symptomatic and asymptomatic individuals. Several clinical studies found a predictive value that was superior to conventional risk factors. Clinically, the use of coronary calcification assessment may therefore be beneficial in patients who, based on traditional risk factors, seem to be at "intermediate risk" for coronary events (10-year event risk 10-20%) in order to decide on the aggressiveness of risk factor modification. The role of coronary calcium quantification to monitor the progression of disease has not been clarified yet. Large, ongoing trials will provide further data as to the relative merit of coronary calcium assessment for risk stratification and will help to more clearly define its clinical role. The relationship between coronary calcium and coronary stenoses is more complex. While the absence of coronary calcifications makes significant coronary stenoses unlikely, even large amounts of coronary calcium do not necessarily indicate the presence of coronary artery stenoses. Pronounced coronary calcifications as an isolated finding should therefore not be the motivation for invasive diagnostic procedures in the absence of other evidence of ischemic heart disease.

  6. Multiplanar spiral CT enterography in patients with Crohn's disease using a negative oral contrast material: initial results of a noninvasive imaging approach

    Energy Technology Data Exchange (ETDEWEB)

    Reittner, Pia; Goritschnig, Toria; Doerfler, Otto [Department of Radiology, Karl Franzens Medical School and University Hospital Graz, Auenbruggerplatz 9, 8036 Graz (Austria); Petritsch, Wolfgang; Hinterleitner, Thomas [Department of Internal Medicine, Karl Franzens Medical School and University Hospital Graz, Auenbruggerplatz 9, 8036 Graz (Austria); Preidler, Klaus W.; Szolar, Dieter H. [Diagnostikum Graz Sued West, Weblinger Guertel 25, 8054 Graz (Austria)

    2002-09-01

    The aim of this study was to prospectively define the role of multiplanar spiral CT enterography with a new negative oral contrast material for noninvasive assessment of the small bowel in patients with Crohn's disease. Thirty patients with established Crohn's disease prospectively underwent spiral CT enterography at 45-60 min after distension of the small bowel with 1400 ml of a negative oral contrast material (Mucofalk water enema). Spiral CT scans were obtained 50 s after administration of intravenous contrast material with the following parameters: 5-mm collimation; 7.5-mm/s table feed; and 3-mm reconstruction interval. The adequacy of bowel opacification, luminal distension, and the contribution of two-dimensional multiplanar reformatted imaging were assessed by two observers. Spiral CT imaging findings were compared with results of enteroclysis as well as endoscopic and histological findings in all patients. Spiral CT enterography with Mucofalk water enema was well tolerated in 29 of 30 patients. Findings on spiral CT enterography were comparable with those of barium studies in 25 of 30 patients, superior to those on barium studies in 4 patients, and inferior in 1 patient (p<0.05). The addition of multiplanar reformatted images to axial spiral CT scans significantly improved observers' confidence in image interpretation (p<0.05) but did not reveal additional abnormalities. Multiplanar spiral CT enterography with Mucofalk excellently provides information in patients with Crohn's disease. This technique accurately depicts the level of small bowel obstruction and the extent of inflammatory small bowel disease and its extraluminal complications. (orig.)

  7. Measurement of renal cortical thickness using spiral CT in early diabetic nephropathy

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Bong Sig; Chung, Won Jung; Park, Byeong Ho; Choi, Jong Cheol; Nam, Kyung Jin; Lee, Yung Il; Chung, Duk Hwan [Donga Univ. College of Medicine, Pusan (Korea, Republic of)

    1997-03-01

    To compare the ratio of renal cortical thickness to renal parenchymal thickness in early diabetic nephropathy and in normal control group. We performed spiral CT in 17 patients suffering from diabetic nephropathy without renal failure or renal atrophy. The normal control group consisted of 19 persons who were normal on renal function test and did not show any abnormality of the kidney. Renal cortical and parenchymal thicknesses were measured at renal hilum level perpendicular to the renal surface by electronic caliper on contrast-enhanced transverse scan demonstrating the cortical nephrogram phase. Using student's test, the difference in renal parenchymal and cortical thickness between the two groups was tested for statistical significance. There was no significant difference in renal parenchymal thickness between the two groups (p>0.05);the patient group had a thicker renal cortex than the normal control group however (p<0.05). The ratio of renal cortical thickness to parenchymal thickness in early diabetic nephropathy patients (Rt.:0.041{+-}0.051, Lt.:0.382{+-}0.053) was significantly higher than in the normal control group (Rt.:0.331{+-}0.067, Lt.:0.323{+-}0.064). The kidney of early diabetic nephropathy patients had a thicker renal cortex than normal kidney.

  8. Recurrent pyogenic cholangitis: clinico-pathologic correlation of focal attenuation differences on multi-phasic spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jun Yong; Han, Joon Koo; Kim, Tae Kyoung; Kim, Seog Joon; Kim, Hyun Bum; Choi, Byung Ihn [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2002-02-01

    To determine the clinical and the pathologic significance of the focal attenuation differences (FAD) and bile duct wall enhancement occurring in recurrent pyogenic cholangitis (RPC) and seen at multiphasic spiral CT. Among the multiphasic (non-contrast, arterial and portal or delayed phase) spiral CT findings of 60 consecutive patients, two types of FAD were noted during the non-contrast phase. These were Type A (iso) and Type B (low attenuation), and their distribution pattern (lobar versus patchy, multifocal) and the and the presence or absence of bile duct wall enhancement were recorded. The radiologic findings were correlated with the clinical and pathologic findings. Two types of FAD were noted in 40 of the 60 patients. Active in flammation was present in 19 of the 27 with Type-A and in ten of the 15 in whom the presence of RPC was pathologically proven. Ten of the 13 with Type-B FAD were in a subclinical state, and nine of the ten in whom RPC was pathologically proven had chronic inflammation. Among 20 patients who did not have FAD, RPC was subclinical in 18 and dormant in nine of the eleven in whom its presence was pathologically proven (p<0.001). Clinico-pathologic correlation with bile duct wall enhancement and the distribution pattern of FAD showed no statistical significance. The inflammatory activity of RPC can be predicted by analysis of the FAD seen at multiphasic spiral CT.

  9. Homoclinic (Heteroclinic) Orbit of Complex Dynamical System and Spiral Structure

    Institute of Scientific and Technical Information of China (English)

    FU Zun-Tao; LIU Shi-Da; LIU Shi-Kuo; LIANG Fu-Ming; XIN Guo-Jun

    2005-01-01

    Starting from iterated systems, it is shown that the homoclinic (heteroclinic) orbit is a kind of spiral structure. The emphasis is laid to show that there are homoclinic or heteroclinic orbits in complex discrete and continuous systems, and these homoclinic or heteroclinic orbits are some kind of spiral structure.

  10. 多排螺旋CT(MSCT)动态增强对孤立性肺结节血流模式的评价%Evaluation of Blood Flow Patterns of Solitary Pulmonary Nodules with Dynamic Multi-slice Spiral Computed Tomography

    Institute of Scientific and Technical Information of China (English)

    LI Shenjiang; 李慎江; XIAO Xiangsheng; 肖湘生; LI Huimin; 李惠民; LIU Shiyuan; LI Chengzhou; ZHANG Chenshi; TAO Zhiwei; YANG Chunshan

    2004-01-01

    Objective: To evaluate the efficacy of dynamic multi-slice spiral computed tomography (MSCT)for providing quantitative information about blood flow patterns of solitary pulmonary nodules (SPNs)and differentiating solitary pulmonary nodules (SPNs). Methods: 37 patients with SPNs (diameter≤4cm; 24 with maliagnant; 6 with benign; 7 with inflammatory) underwent multi-location dynamic contrast material-enhanced (90 mL, 4 mL/s) serial CT. Peak height and ratio of peak height of the SPN to that of the aorta were measured. Precontrast attenuation was recorded. Perfusion was calculated from the maximum gradient of the time-attenuation curve and the peak height of the aorta. Results: Peak heights of malignant (37.98 HU±17.97) and inflammatory (43.86 HU±14.20) SPNs were significantly higher than those of benign SPNs (5.65 HU±6.43) (P<0.001; P<0.001). No statistically significant difference in the peak height was found between malignant and inflammatory SPNs (P=0.647>0.01). SPN-to-aorta ratio in inflammatory SPNs (20.78%±4.14) was significantly higher than that in benign (2.00%±2.26) and malignant (14.63%±6.22) SPNs (P<0.001; P=0.021<0.05). SPN-to-aorta ratio in malignant SPNs was significantly higher than that in benign SPNs (P<0.001). Perfusion value in inflammatory SPNs [78.39 mL/(min.100g)±55.18] was significantly higher than that of benign [2.13 mL/(min.100g)±2.84] and malignant [33.91mL/(min.100g)±15.58] SPNs (P<0.001; P=0.001<0.01). Perfusion value in malignant SPNs was significantly higher than that in benign SPNs (P<0.001). Precontrast attenuations of inflammatory (39.36HU±9.57)and benign (37.73 HU±8.39) SPNs were lower than that of malignant SPNs (45.73 HU±4.21)(P=0.04<0.05; P=0.014<0.05). No statistically significant difference in the precontrast attenuation was found between benign and inflammatory SPNs (P=0.836>0.01). Conclusion: MSCT provides quantitative information about blood flow patterns of solitary pulmonary nodules

  11. Spiral-wave dynamics depend sensitively on inhomogeneities in mathematical models of ventricular tissue

    Science.gov (United States)

    Shajahan, T. K.; Sinha, Sitabhra; Pandit, Rahul

    2007-01-01

    Every sixth death in industrialized countries occurs because of cardiac arrhythmias such as ventricular tachycardia (VT) and ventricular fibrillation (VF). There is growing consensus that VT is associated with an unbroken spiral wave of electrical activation on cardiac tissue but VF with broken waves, spiral turbulence, spatiotemporal chaos and rapid, irregular activation. Thus spiral-wave activity in cardiac tissue has been studied extensively. Nevertheless, many aspects of such spiral dynamics remain elusive because of the intrinsically high-dimensional nature of the cardiac-dynamical system. In particular, the role of tissue heterogeneities in the stability of cardiac spiral waves is still being investigated. Experiments with conduction inhomogeneities in cardiac tissue yield a variety of results: some suggest that conduction inhomogeneities can eliminate VF partially or completely, leading to VT or quiescence, but others show that VF is unaffected by obstacles. We propose theoretically that this variety of results is a natural manifestation of a complex, fractal-like boundary that must separate the basins of the attractors associated, respectively, with spiral breakup and single spiral wave. We substantiate this with extensive numerical studies of Panfilov and Luo-Rudy I models, where we show that the suppression of spiral breakup depends sensitively on the position, size, and nature of the inhomogeneity.

  12. Noninvasive Detection of Coronary Artery Stenosis Using 16-slice Spiral CT: a Comparison with Selective X-ray Coronary Angiography

    Institute of Scientific and Technical Information of China (English)

    SHI Heshui; HAN Ping; KONG Xiangquan; FENG Gansheng; Martin HK Hoffmann

    2006-01-01

    The role of 16-slice spiral CT was evaluated in the diagnosis of coronary stenosis, with selective X-ray coronary angiography (SCA) serving as the reference standard. Sixty-five patients who were suspected of having coronary heart disease, without percutaneous transluminal coronary angioplasty or coronary bypass-grafting, were investigated using 16-slice CT. Eight patients with pre-scan heart rate of more than 80 beats/min were given β-blockers. After the retrospectively ECG-gated axial imaging reconstruction, volume redering (VR), multi-planar reconstruction (MPR), curved MPR and maximum intensity projection (MIP) were used to reconstruct. Every segment of coronary artery with a diameter ≥1.5 mm was assessed, and the presence on CT with a stenosis exceeding 50% diameter reduction was compared with that on SCA. The reasons which lead to some segments unevaluable were analysed. Compared with SCA, 93% coronary segments and 94 % main branches were evaluable. Residual cardiac motion artifacts, severe calcification and poor opacification made 58%, 28% and 14% of the remaining 60 segments unevaluable respectively. Without routine administration of β-blockers, good coronary imaging quality can be acquired using 16-slice spiral CT. It is a reliable noninvasive method for detection of obstructive coronary artery disease.

  13. Spiral CT Diagnosis of Pulmonary Laceration%肺撕裂伤的螺旋CT诊断

    Institute of Scientific and Technical Information of China (English)

    王之平; 许永明

    2011-01-01

    Objective To analyze the spiral CT features of lung laceration. Methods 29 patients with lung laceration were examined by spiral CT in 1-4 hours after injury. 16 cases of them were followed-up in 1-3 days,4 days-3 weeks and 3 weeks later respectively after injury. Results There were 38 focuses among 29 cases,including solitary lesions ( n=12) and multiple lesions ( n=3) in right lung, solitary lesions (n=l0) and multiple lesions (n=l) in left lung, and multiple lesions ( n= 3) in bilateral lungs.The first cmergency CT findings included 5 types: (1) single cavities (n=3) and cavity lesions with air-fluid levels (n=l0) ; (2)multiple cavity lesions with air-fluid levels (n=7) ; (3) single or multiple air cavities in patchy hemorrhage or wet lung (n=12) ;(4) simplex pulmonary hematomas (n=3) ; (5) hematomas with bubbles inside ( n= 3). There were patchy, cloudy or halo-like ground glass opacity (GGO) around all of the focuses. CT findings in 16 cases followed-up included: (1) in 1-3 days, the air cavity appeared air-fluid levels, the fluid in the cavity lesions with air-fluid levels increased, the cope of hemorrhage diminished and there became hematomas, with definite margins, the GGO around the lesions gradually absorbed; (2)in 4 days-3 weeks, 8 lesions be came hematomas, with definife margins(8/16) , 3 cavity with air-fluid levels lesions diminished, the air-fluid levels disappeared and became thick wall cavity( 3/16) , 5 lesions didn't changed much( 5/16) , the GGO around all the focuses became diminished or disappeared; (3) 3 weeks later, the cavity and the cavity with air-fluid levels diminished or disappcared, the cavity in hemorrhage entirely disappeared, pulmonary hemotomas diminished, small hematoma absorbed, leaving stripe-like shadows, 3 pulmonary hemotomas were not absorbed after half-year repeated CT examination, which appeared as masses. Conclusion cavity lesion,cavity with airfluid levels, pulmonary hematoma and GGO around of the focuses are the

  14. The Use of Multislice Spiral CT to Predict the Resectability of Central Lung Cancer: Correlation with Pathologic and Surgical Findings

    Institute of Scientific and Technical Information of China (English)

    Yang Liu; Yu'e Sun; Naikang Zhou; Qiming Xu

    2005-01-01

    OBJECTIVE To assess the accuracy of multi-slice spiral CT (MSCT) with imaging reconstruction in judging central pulmonary vascular involvement from central lung cancer, and to explore its ability to predict the resectability of lung cancer.METHODS MSCTs were conducted on 48 patients who were diagnosed preoperatively with central lung cancer. Images of pulmonary arteries and veins that might affect Iobectomy or pneumonectomy were reconstructed by means of imaging processing techniques. Then the relationship of the tumor to the vessels was assessed prospectively on both axial CT images and axial CT images plus reconstructed images(CT-RI) in comparison to subsequent pathologic and surgical findings.RESULTS MSCTs were obtained on all 48 patients whom 42 underwent thoracotomy, Iobectomy or pneumonectomy. Compared with the axial CT images,CT-RI was more accurate in judging the relationship of the central pulmonary vessels to the tumor based on subsequent pathologic 78 vessels studiedand surgical findings (186 vessels studied) (0.01 <P<0.05). The sensitivity and positive predictive value of unresectability of the vessels were all remarkably higher with CT-RI (P<0.01).CONCLUSION MSCT with imaging reconstruction can improve the recognition of neoplastic invasion of central pulmonary vessels. It can be used to predict preoperatively the resectability of central lung cancer and to plan surgery.

  15. Early clinical phase of patient's management after polytrauma using 1- and 4-slice helical CT; Fruehes klinisches Management nach Polytrauma mit 1- und 4-Schicht-Spiral-CT

    Energy Technology Data Exchange (ETDEWEB)

    Kloeppel, R.; Kahn, T. [Klinik und Poliklinik fuer Diagnostische Radiologie, Universitaetsklinikum Leipzig (Germany); Schreiter, D. [Chirurgische Intensivtherapieabteilung, Zentrum fuer Chirurgie, Universitaetsklinikum Leipzig (Germany); Dietrich, J. [Abt. Neuroradiologie der Klinik und Poliklinik fuer Diagnostische Radiologie, Universitaetsklinikum Leipzig (Germany); Josten, C. [Klinik und Poliklinik fuer Unfall- und Wiederherstellungschirurgie, Zentrum fuer Chirurgie, Universitaetsklinikum Leipzig (Germany)

    2002-07-01

    In the early clinical phase the comprehensive imaging of patients with multiple trauma using helical CT is already established. Aim of this study was to assess whether MSCT may improve the patient management and the diagnostic results.The procedure is designed as follows: after life-thretening treatment x-ray of chest and ultrasound are carried out in the emergency room. Then the patient is moved to CT. From 1998 to december 2000 241 patients were examined using a single slice helical CT (Somatom plus 4), in 2001 79 patients using a 4-slice helical CT (Somatom VZ, Siemens Med.Sol.). After CT selected radiograms of the extremities were taken.359 of 360 procedures were carried out successfully. Excluding 1 case (death during 1-sl. h CT) all relevant lesions of head, neck, and body were diagnosed. Although the patients had an injury severity score of {approx}30. The change from 1slice-helical CT to 4 slice-helical CT allowed us to reduce the stay in the CT room from 28 to 16 min. The total lethality decreased by {approx}4%.Advantages for the patient arose from the standardized examination protocol using multislice CT. If integrated in an interdisciplinary management concept, it is a good compromise between examination time, comprehensive diagnostic imaging, life-saving therapeutic procedures, and therapy planning. (orig.) [German] Die klinische Erstversorgung Polytraumatisierter schliesst inzwischen in vielen Unfallkliniken den fruehzeitigen Einsatz der Spiral-CT ein. Kann die neuerlich eingefuehrte Mehrschicht-Spiral-CT Ergebnisse und Patientenmanagement weiter verbessern?Nach lebensrettenden Sofortmassnahmen, Thoraxroentgen und Notsonographie im Schockraum erfolgte die CT: Von 1998-2000 wurden 241 Patienten mit einem 1-Schicht-Spiral-CT (Somatom plus 4) und in 2001 79 Patienten mit einem 4-Schicht-Spiral-CT (Somatom VZ, beide Siemens Med. Sol.) untersucht. Klinisch ausgewaehlte Extremitaetenaufnahmen wurden ergaenzt.359 von 360 Untersuchungen verliefen erfolgreich

  16. Computer-aided diagnosis: a 3D segmentation method for lung nodules in CT images by use of a spiral-scanning technique

    Science.gov (United States)

    Wang, Jiahui; Engelmann, Roger; Li, Qiang

    2008-03-01

    Lung nodule segmentation in computed tomography (CT) plays an important role in computer-aided detection, diagnosis, and quantification systems for lung cancer. In this study, we developed a simple but accurate nodule segmentation method in three-dimensional (3D) CT. First, a volume of interest (VOI) was determined at the location of a nodule. We then transformed the VOI into a two-dimensional (2D) image by use of a "spiral-scanning" technique, in which a radial line originating from the center of the VOI spirally scanned the VOI. The voxels scanned by the radial line were arranged sequentially to form a transformed 2D image. Because the surface of a nodule in 3D image became a curve in the transformed 2D image, the spiral-scanning technique considerably simplified our segmentation method and enabled us to obtain accurate segmentation results. We employed a dynamic programming technique to delineate the "optimal" outline of a nodule in the 2D image, which was transformed back into the 3D image space to provide the interior of the nodule. The proposed segmentation method was trained on the first and was tested on the second Lung Image Database Consortium (LIDC) datasets. An overlap between nodule regions provided by computer and by the radiologists was employed as a performance metric. The experimental results on the LIDC database demonstrated that our segmentation method provided relatively robust and accurate segmentation results with mean overlap values of 66% and 64% for the nodules in the first and second LIDC datasets, respectively, and would be useful for the quantification, detection, and diagnosis of lung cancer.

  17. Effects of abnormal excitation on the dynamics of spiral waves

    Science.gov (United States)

    Min-Yi, Deng; Xue-Liang, Zhang; Jing-Yu, Dai

    2016-01-01

    The effect of physiological and pathological abnormal excitation of a myocyte on the spiral waves is investigated based on the cellular automaton model. When the excitability of the medium is high enough, the physiological abnormal excitation causes the spiral wave to meander irregularly and slowly. When the excitability of the medium is low enough, the physiological abnormal excitation leads to a new stable spiral wave. On the other hand, the pathological abnormal excitation destroys the spiral wave and results in the spatiotemporal chaos, which agrees with the clinical conclusion that the early after depolarization is the pro-arrhythmic mechanism of some anti-arrhythmic drugs. The mechanisms underlying these phenomena are analyzed. Project supported by the National Natural Science Foundation of China (Grant Nos. 11365003 and 11165004).

  18. Dual source multidetector CT-angiography before transcatheter aortic valve implantation (TAVI) using a high-pitch spiral acquisition mode

    Energy Technology Data Exchange (ETDEWEB)

    Wuest, W.; Anders, K.; May, M.S.; Uder, M. [University of Erlangen, Department of Radiology, Erlangen (Germany); Schuhbaeck, A.; Gauss, S.; Marwan, M.; Arnold, M.; Muschiol, G.; Daniel, W.G.; Achenbach, S. [University of Erlangen, Department of Cardiology, Erlangen (Germany); Ensminger, S. [University of Erlangen, Department of Cardiac Surgery, Erlangen (Germany)

    2012-01-15

    Transcatheter Aortic Valve Implantation (TAVI) is an alternative to surgical valve replacement in high risk patients. Angiography of the aortic root, aorta and iliac arteries is required to select suitable candidates, but contrast agents can be harmful due to impaired renal function. We evaluated ECG-triggered high-pitch spiral dual source Computed Tomography (CT) with minimized volume of contrast agent to assess aortic root anatomy and vascular access. 42 patients (82 {+-} 6 years) scheduled for TAVI underwent dual source (DS) CT angiography (CTA) of the aorta using a prospectively ECG-triggered high-pitch spiral mode (pitch = 3.4) with 40 mL iodinated contrast agent. We analyzed aortic root/iliac dimensions, attenuation, contrast to noise ratio (CNR), image noise and radiation exposure. Aortic root/iliac dimensions and distance of coronary ostia from the annulus could be determined in all cases. Mean aortic and iliac artery attenuation was 320 {+-} 70 HU and 340 {+-} 77 HU. Aortic/iliac CNR was 21.7 {+-} 6.8 HU and 14.5 {+-} 5.4 HU using 100 kV (18.8 {+-} 4.1 HU and 8.7 {+-} 2.6 HU using 120 kV). Mean effective dose was 4.5 {+-} 1.2 mSv. High-pitch spiral DSCTA can be used to assess the entire aorta and iliac arteries in TAVI candidates with a low volume of contrast agent while preserving diagnostic image quality. (orig.)

  19. Multidetector spiral CT renal angiography in the diagnosis of renal artery fibromuscular dysplasia

    Energy Technology Data Exchange (ETDEWEB)

    Sabharwal, Rohan [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia)]. E-mail: rohan50000@yahoo.com; Vladica, Philip [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia); Coleman, Patrick [Department of Renal Medicine, Westmead Hospital, Sydney, NSW (Australia)

    2007-03-15

    Objective: The aim of this study was to evaluate the role and detection rate of multidetector spiral CT renal angiography (CTA) as compared with conventional angiography (CA), the commonly accepted gold standard, in the diagnosis of renal artery fibromuscular dysplasia (FMD). In addition, the role of CTA reconstructions (multiplanar reformatted images (MPR), maximum intensity projections (MIP) and shaded-surface display (SSD)) in the detection of FMD was also evaluated. Materials and methods: CTA results were retrospectively reviewed in 21 hypertensive patients with CA-proven FMD. Clinical indications for referral included resistant hypertension (requiring greater than three antihypertensive medications), labile hypertension, hypertension in combination with renal impairment and the presence of abdominal bruits in the context of systemic hypertension. In some cases, these clinical indications were supplemented by positive results in other tests, including plasma renin assay, captopril scintigraphy and/or Doppler ultrasound. The findings of CA in these 21 patients were compared to CTA. Results: Mean patient age was 62.33 + 14.32 years (range 24-85 years). CTA identified all 42 main renal arteries (100%) and all 10 accessory renal arteries (100%) visualized on CA. In the diagnosis of FMD, CTA detected all 40 (100%) lesions detected by CA. No single CTA reconstruction technique was able to detect all lesions noted on corresponding CA, however, upon review of all CTA reconstructions (MPR, MIP and SSD) in each case, every lesion was correctly identified by CTA. Conclusion: Our experience suggests that CTA is a non-invasive, reliable and accurate method for the diagnosis of renal artery fibromuscular dysplasia. Moreover, in our experience CTA has many advantages as a diagnostic screening tool over CA, including accessibility, speed, lower complication profile, versatility and cost-effectiveness. CTA shows great potential as a guiding tool for directing subsequent

  20. Peripheral pulmonary nodules: Relationship between multi-slice spiral CT perfusion imaging and tumor angiogenesis and VEGF expression

    Directory of Open Access Journals (Sweden)

    Cheng Xiao-Ling

    2008-06-01

    Full Text Available Abstract Background The aim of this study is to investigate the relationship between16-slice spiral CT perfusion imaging and tumor angiogenesis and VEGF (vascular endothelial growth factor expression in patients with benign and malignant pulmonary nodules, and differential diagnosis between benign and malignant pulmonary nodules. Methods Sixty-four patients with benign and malignant pulmonary nodules underwent 16-slice spiral CT perfusion imaging. The CT perfusion imaging was analyzed for TDC (time density curve, perfusion parametric maps, and the respective perfusion parameters. Immunohistochemical findings of MVD (microvessel density measurement and VEGF expression was evaluated. Results The shape of the TDC of peripheral lung cancer was similar to those of inflammatory nodule. PH (peak height, PHpm/PHa (peak height ratio of pulmonary nodule to aorta, BF (blood flow, BV (blood volume value of peripheral lung cancer and inflammatory nodule were not statistically significant (all P > 0.05. Both showed significantly higher PH, PHpm/PHa, BF, BV value than those of benign nodule (all P 0.05. In the case of adenocarcinoma, BV, BF, PS, PHpm/PHa, and MVD between poorly and well differentiation and between poorly and moderately differentiation were statistically significant (all P 0.05. PH, PHpm/PHa, BV, and PS of benign nodule were significantly lower than those of peripheral lung cancer (all P Conclusion Multi-slice spiral CT perfusion imaging closely correlated with tumor angiogenesis and reflected MVD measurement and VEGF expression. It provided not only a non-invasive method of quantitative assessment for blood flow patterns of peripheral pulmonary nodules but also an applicable diagnostic method for peripheral pulmonary nodules.

  1. Spiral CT arthrography of multiplanar reconstruction and virtual arthroscopy technique in diagnosis of knee with internal derangements

    Institute of Scientific and Technical Information of China (English)

    熊传芝; 郝敬明

    2004-01-01

    5Objective:To evaluate the values of spiral CT arthrography with multiplanar reconstruction and virtual arthroscopy technique in diagnosis of internal derangements of the knee. Methods:Ten bovine knees were used for experiment. The menisci, anterior and posterior cruciate ligaments and cartilage of these 10 bovine knees were injured with a hook. Each of the joints was injected with 100 mi air, then soon scanned with a PQ6000 spiral computed tomography scanner. The data obtained was input into the work station, and multiplanar reconstruction technique was used to illustrate lesions in the knees. The results of CT diagnosis were compared to those found by gross inspection of the specimens. Clinically, 10 knees of 9 patients diagnosed as internal derangement were evaluated with the same method after 50-70 ml air was injected into each of the joints. Nine months later, the data of 2 patients were used for CT endoscopy reconstruction. The results were compared with intraoperative findings. Results:Experimentally,the sensitivity and specificity were 88.9% and 93.9% by detection of meniscal abnormalities, 85.7% and 100% by detection of cruciate ligament lesions, and 72.7% and 100% by detection of cartilage damage, respectively. Clinically, the sensitivity and specificity were 90. 0% and 95.0% by detection of meulscal lesion. As to ligament, the figures were 85.7% and 100% respectively. Images of virtual arthroscopy simulated the images of real arthroscopy. Conclnsious:Spiral CT arthrography of multiplanar reconstruction technique offers fime images of internal structures of the knee, with clear border and internal structure. It is an accurate method for detecting meulscal, cruciate and collateral ligament and cartilaginous lesions that cause internal derangement of the knee.Virtual arthroscopy technique is a hopeful method for detecting reasons of derangement of the knee.

  2. 肝细胞癌螺旋CT同层动态扫描表现与肿瘤血管生成的相关性%Single-level dynamic spiral CT of hepatocellular carcinoma: correlation between imaging features and tumor angiogenesis

    Institute of Scientific and Technical Information of China (English)

    陈卫霞; 闵鹏秋; 宋彬; 肖邦良; 刘燕; 王文冬; 陈宪; 徐剑英

    2001-01-01

    目的探讨肝细胞癌螺旋CT同层动态扫描所获部分参数和形态学表现特征与肿瘤血管生成的相关性。方法经病理证实的肝细胞癌26例,全肝平扫后选择靶平面行同层动态扫描和门脉期全肝扫描,评价癌灶形态表现特征、时间-密度曲线(T-DC)走势,并计算癌灶强化峰值(PV)和强化比值(CER)。组织切片经Ⅷ因子相关抗原(F8RA)和血管内皮生长因子(VEGF)免疫组化染色,分析癌组织微血管数(MVC)和癌细胞VEGF表达阳性率。将CT形态表现和所获部分参数与组织病理学改变进行比较研究。结果癌灶PV 7.9~75.2 HU,CER 3.8%~36.0%;MVC 6~91,VEGF阳性率32%~78%。癌灶PV、CER与MVC呈显著正相关(r分别为0.508、0.423,P值分别0.05);肿瘤新生血管分布影响T-DC走势,肿瘤血管是否丰富及其组织结构特点影响肿瘤强化特征。结论根据肝细胞癌螺旋CT同层动态扫描部分参数及T-DC走势和增强大体形态表现,可推测癌组织MVC和肿瘤新生血管分布特征,并可反映肿瘤血管是否丰富及肿瘤组织结构特点。%Objective To investigate the correlation of the enhancement imaging features of hepatocellular carcinoma (HCC) and relevant parameters revealed by single-level dynamic spiral CT scanning with tumor microvessel counting (MVC). Methods The study included 26 histopathologically proven HCC patients. Target-slice dynamic scanning and portal venous phase scanning were performed for all patients. The time-density curves were generated with measurement of relevant parameters including: peak value (PV) and contrast enhancement ratio (CER), and the gross enhancement morphology analyzed. Histopathological slides were carefully prepared for the standard F8RA and VEGF immunohistochemical staining and tumor microvessel counting and calculation of VEGF expression percentage of tumor cells. The enhancement imaging features of HCC lesions were

  3. [Analysis and discussion on the facet of the spinal column, spiral CT lock multiplanar reconstruction and 
3D reconstruction].

    Science.gov (United States)

    Zheng, Zhifeng; Wang, Shuhang; Si, Donglei

    2015-10-01

    To investigate the imaging appearances and diagnostic value of axial CT scanning, spiral CT multiplanar reconstruction (MPR) and three-dimensional (3D) reconstruction in vertebral facet joints locking.
 A total of 31 cases of vertebral facet joints locking, with injuries in different parts, were recruited to explore their CT features, and to evaluate their advantages in diagnosis against each other.
 Among the CT images of 31 cases with "Hamburger" sign in axial view, there were 21 cases of cervical spine and 10 cases of thoracolumbar segment; in vertical plane of MPR, "top to top" form was formed below the inferior and the superior articular process, accompanied by I° spondylolisthesis and inferior articular process tip fracture; 5 cases were unilateral locked cervical spine; none case for thoracolumbar segment. The inferior articular process was crossed with the superior articular process below and moved forward, formed "back to back" form, accompanied by II°-III° spondylolisthesis. 9 or 6 cases were bilateral or unilateral locking cervical spine, 10 cases were thoracolumbar segment, accompanied by teardrop fracture in the vertebral body below cervical spine. In coronal plane of MPR, inferior articular process showed ingression in different extent, and relied on the superior articular process below or locked in the articular fossa (21 cases for cervical spine); inferior articular process displayed upward displacement or appeared with the superior articular process at the same time, which meant joint structure disappearing thoracolumbar segment (10 cases). In 3D reconstruction, 31 cases displayed clearly in the spatial form of vertebral facet joints locking and the degree of spondylolisthesis of vertebral body.
 MPR and 3D image were more clear and intuitive in vertebral facet joints locking comparing to axial CT scan image. Spiral CT MPR and 3D reconstruction contributed to the diagnosis of vertebral facet joints locking and the reduction of misdiagnoses

  4. Optimized Temporal Window for Detection and Characterization of Renal Cell Carcinomas with Dynamic CT Scanning

    Institute of Scientific and Technical Information of China (English)

    Jinhong Wang; Peijun Wang; Xiaohu Zhao; Xinqin Mao; Xiaolong Gao; Jun Liu

    2005-01-01

    OBJECTIVE To investigate the optimized time period for detection and characterization of renal cell carcinomas (RCC) when the specific CT features appear during spiral dynamic CT scanning, and to optimize an effective scanning protocol of spiral CT for evaluating RCC.METHODS Twenty-four patients with RCC verified by pathology had undergone a dynamic CT (D-CT) scan. A plain scan was employed to select the target slice. Single-level dynamic scanning started at 14-17 s after the intravenous contrast media had been administered, with a scan interval of 4.9 s acquiring a total number of 17~24 frames. A regular CT scan of the whole kidney followed by a delayed single slice acquisition through the target slice in the excretory phase was performed. Images were assessed in two ways: (1) A group of experienced radiologists reviewed the CT images to find when the specific signs appeared and when the CT features of RCC were optimally displayed; (2) Data measurement of the time-density curves (T-DC) of RCC. The exact time was obtained when the densities of the tumor, renal parenchyma, medulla and aorta reached their peak enhancement, thus also the time when the density difference between tumor and parenchyma was at maximum (Max T-M). Based on the slope of the contrast media uptake curve, T-DC types were ranked from the smallest to the biggest of slope as type A, B and C.RESULTS 1. The review of the CT images by the radiologists showed that the CT features of RCC were optimally demonstrated at 70.2 s. The earliest time at which RCC CT features were examined was at 23.9 s. 2. Image data analysis: the time that the density (or CT value) of the tumor mass reached peak enhancement was at 54 s and peak value was at 80.4 Hu for RCC. The time of the maximal difference of densities between tumor and renal parenchyma was at 102 s.CONCLUSION The following proposal is the scanning protocol for detecting RCC recommended by our research: After a plain scan to determine the target level, a

  5. Radiation dose for investigation of the chest and abdomen. Comparison of sequential, spiral and electron beam computed tomography; Strahlenexposition bei der CT-Untersuchung des Thorax und Abdomens. Vergleich von Einzelschicht-, Spiral- und Elektronenstrahlcomputertomographie

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.R.; Schaetzl, M.; Bruening, R.; Schoepf, U.J.; Reiser, M.F. [Klinikum Grosshadern, Muenchen (Germany). Inst. fuer Radiologische Diagnostik; Feist, H. [Muenchen Univ. (Germany). Radiologische Klinik und Poliklinik; Baeuml, A. [Bundesamt fuer Strahlenschutz, Oberschleissheim (Germany). Inst. fuer Strahlenhygiene

    1998-09-01

    Comparison of radiation exposure applied by different types of CT scanners for the investigation of the chest and abdomen. Determination of radiation exposure applied by multi-phase spiral CT. Estimation of the dose in air in the system axis of the scanner, the CT dose index (CTDI) and the effective dose for electron beam tomography (EBT) and two conventional CT scanners (sequence, SEQ; spiral, SCT). For EBT, dose in system axis for investigation of the abdomen was above 50 mGy. Effective dose for investigation of the chest and abdomen was higher with EBT (11 and 26 mSv, respectively), than with conventional CT (SEQ, 4 and 20 mSv; SCT, 2 and 7 mSv). The effective dose for a biphasic investigation (liver 5 mSv, kidney 4 mSv) was below, for a triphasic investigation of the abdomen (6 mSv). Investigation of the abdomen with the EBT should only be performed for certain indications. With spiral CT, effective dose is much lower than with EBT. (orig.) [Deutsch] Die Strahlenexposition bei der Untersuchung von Thorax und Abdomen mit verschiedenen CT-Scannertypen sollte verglichen werden. Zusaetzlich sollte die Exposition beim Mehrphasen-Spiral-CT ermittelt werden. Die Dosis in der Systemachse, gemessen in freier Luft, (Achsendosis), der Computertomographie-Dosis-Index (CTDI) und die effektive Dosis nach ICRP 60 wurden bei einem Elektronenstrahl-CT (EBT) und zwei konventionellen CT-Scannern (sequentiell=SEQ, spiral=SCT) bestimmt. Beim EBT liegt die Achsendosis bei der Untersuchung des Abdomens ueber 50 mGy. Die effektive Dosis fuer die Untersuchung von Thorax und Abdomen war bei der EBT (11 bzw. 26 mSv) hoeher als beim konventionellen CT (SEQ 4 bzw. 20 mSv; SCT 2 bzw. 7 Sv). Die effektive Dosis einer 2-Phasen-Untersuchung (Leber 5 mSv, Niere 4 mSv) liegt unter, die einer 3-Phasen-Untersuchung (Leber 7 mSv) ueber der effektiven Dosis einer Untersuchung des gesamten Abdomens (6 mSv). Die Untersuchung des Abdomens sollte mit dem EBT nur nach strenger Indikationsstellung

  6. Dynamics of Non-Steady Spiral Arms in Disk Galaxies

    CERN Document Server

    Baba, Junichi; Wada, Keiichi

    2012-01-01

    In order to understand the physical mechanisms underlying non-steady stellar spiral arms in disk galaxies, we analyzed the growing and damping phases of their spiral arms using three-dimensional $N$-body simulations. We confirmed that the spiral arms are formed due to a swing amplification mechanism that reinforces density enhancement as a seeded wake. In the damping phase, the Coriolis force exerted on a portion of the arm surpasses the gravitational force that acts to shrink the portion. Consequently, the stars in the portion escape from the arm, and subsequently they form a new arm at a different location. The time-dependent nature of the spiral arms are originated in the continual repetition of this non-linear phenomenon. Since a spiral arm does not rigidly rotate, but follows the galactic differential rotation, the stars in the arm rotate at almost the same rate as the arm. In other words, every single position in the arm can be regarded as the co-rotation point. Due to interaction with their host arms, ...

  7. Spiral CT angiography and surgical correlations in the evaluation of intracranial aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Preda, L.; Di Maggio, E.M.; La Fianza, A.; Dore, R.; Fulle, I.; Solcia, M.; Campani, R. [Istituto di Radiologia, IRCCS Policlinico S. Matteo, p.le C. Golgi, 2, I-27 100 Pavia (Italy); Gaetani, P.; Rodriguez y Baena, R. [Neurosurgery, Istituto Clinico ``Humanitas``, I-20089 Rozzano (Midway Islands) (Italy); Cecchini, A. [Servizio di Radiodiagnostica, IRCCS Policlinico S. Matteo, p.le C. Golgi, 2, I-27 100 Pavia (Italy); Infuso, L. [Neurochirurgia, Dipartimento di Chirurgia, IRCCS Policlinico S. Matteo, p.le C. Golgi, 2, I-27 100 Pavia (Italy)

    1998-06-02

    We investigated the accuracy of spiral computed tomography angiography (CTA) in the detection and study of intracranial aneurysms by comparing CTA with selective angiograms and surgical findings. Twenty-six patients (9 men and 17 women; mean age 53.1 {+-} 1.8 years) with suspected intracranial aneurysms were submitted to CTA (1- to 2-mm slices, pitch 1:1, 24 s, RI = 1) after a conventional CT examination showing subarachnoid hemorrhage (SAH) in 19 cases and during neuroradiological investigations performed for other reasons in 7 cases. One hundred twenty to 150 ml iodate contrast agent (0.3-0.4 gI/ml) were injected intravenously at 5 ml/s rate and with 12- to 25-s delay calculated with a preliminary test bolus. Three-dimensional shaded surface display (3D SSD) and maximum intensity projection (MIP) reconstructions were obtained from axial images. Then, within 48 h, all patients were submitted to digital subtraction angiography (DSA), with separate assessment of CTA and DSA findings. Twenty-two aneurysms shown by CTA were confirmed at DSA and surgery (true positives), whereas the vascular lesion was not confirmed at DSA in 2 cases (false positives). The presence of intracranial aneurysms was excluded at both CTA and subsequent DSA in 7 cases (true negatives) and there were no false negatives; sensitivity was 100 %, specificity 77.8 %, and diagnostic accuracy 93.5 %. Computed tomography angiography aneurysm location was confirmed at surgery in all cases, with very high accuracy in assessing the presence of an aneurysm neck (100 %). Computed tomography angiography accurately depicted the aneurysm shape in 20 of 22 cases, but failed to depict its multilobed nature in 2 cases. The mean aneurysm diameter calculated at CTA was 0.99 {+-} 0.12 cm vs 1.09 {+-} 0.11 cm at surgery (p < 0.01). The present results suggest that the high sensitivity of CTA, if confirmed by further studies, might help in avoiding having to resort to arteriography after negative CTA in SAH patients

  8. Assessment of bone segmentation quality of cone-beam CT versus multislice spiral CT: a pilot study.

    NARCIS (Netherlands)

    Loubele, M.; Maes, F.; Schutyser, F.A.C.; Marchal, G.; Jacobs, R.; Suetens, P.

    2006-01-01

    OBJECTIVES: The objective of this study was to quantitatively assess the quality of jawbone models generated from cone beam computed tomography (CBCT) by comparison with similar models obtained from multislice spiral computed tomography (MSCT). MATERIAL AND METHODS: Three case studies were performed

  9. Spiral CT angiography for demonstrating cerebral aneurysms before and after treatment with titanium clips; Spiral-CT-Angiographie zur Darstellung von zerebralen Aneurysmen vor und nach Versorgung mit Titan-Clips

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.; Volkmar, C.; Weber, J.; Fink, U.; Holzknecht, N.; Reiser, M. [Institut fuer Radiologische Diagnostik, Klinikum Grosshadern, Universitaet Muenchen (Germany); Yousry, T. [Abteilung fuer Neuroradiologie, Institut fuer Radiologische Diagnostik, Klinikum Grosshadern, Universitaet Muenchen (Germany); Steiger, H.J. [Klinik fuer Neurochirurgie, Klinikum Grosshadern, Universitaet Muenchen (Germany)

    1997-11-01

    Purpose: To determine the suitability of spiral CT angiography (SCTA) in patients with intracerebral titanium aneurysm clips. Material and Method: The section parameters were optimised using a phantom. 16 patients were examined preoperatively and 18 following treatment of aneurysms with clips. Results: The resolution, sensitivity and specificity for demonstrating cerebral aneurysms measuring{>=}3 mm was 91.3% and 75% respectively. In 15 patients with intracerebral clips there were no or only minor artefacts; three examinations were of no value because of major metal artefacts. Amongst six aneurysms demonstrated angiographically, two, which measured more than 3 mm, could be shown by SCTA. Conclusion: SCTA was able to demonstrate intracerebral aneurysms measuring{>=}3 mm. Titanium clips did not usually affect image quality significantly. (orig.) [Deutsch] Ziel: Unsere Untersuchungen sollten die Eignung der Spiral-CT-Angiographie (SCTA) fuer Patienten mit intrazerebralen Titan-Aneurysma-Clips pruefen. Material und Methode: An einem Phantom wurden die Schichtparameter optimiert. 16 Patienten wurden praeopertiv und 18 nach operativer Clippung eines Aneurysmas untersucht. Ergebnisse: Die untere Nachweisgrenze, Sensitivitaet und Spezifitaet fuer den Nachweis von zerebralen Aneurysmen lag bei{>=}3 mm, 91,3% und 75%. Bei Patienten mit intrazerebralen Clips wiesen 15 Untersuchungen keine oder geringe Artefakte auf, drei Untersuchungen konnten wegen ausgepraegter Metallartefakte nicht ausgewertet werden. Von den 6 angiographisch nachweisbaren Restaneurysmen konnten zwei mittels SCTA dargestellt werden, deren Durchmesser ueber 3 mm lag. Schlussfolgerung: Mit der SCTA koennen intrazerebrale Aneurysmen und Restaneurysmen{>=}3 mm nachgewiesen werden. Titanclips beeintraechtigen dabei die Bildqualitaet meist nicht nachhaltig. (orig.)

  10. Symbolic Dynamics and Spiral Structures due to the Saddle-Focus Bifurcations

    Science.gov (United States)

    Shilnikov, Andrey; Shilnikov, Leonid; Barrio, Roberto

    2013-01-01

    We examine spiral structures in bi-parametric diagrams of dissipative systems with strange attractors. We show that the organizing center for spiral structures in the Rössler model with the saddle-focus equilibria is related to the change of the structure of the attractor transitioning between the spiral and screw-like types. The structure skeleton is formed by saddlenode bifurcation curves originating from a codimension-two Belyakov point corresponding to the transition to the saddle-focus from a simple saddle. A new computational technique based on the symbolic kneading invariant description for examining dynamical chaos and parametric chaos in systems with Lorenz-like attractors is proposed and tested. This technique uncovers the stunning complexity and universality of spiral structures in the iconic Lorenz equations.

  11. Spiral Structure Dynamics in Pure Stellar Disk Models

    CERN Document Server

    Valencia-Enriquez, Diego

    2013-01-01

    In order to understand the physical mechanism underlying non-steady stellar spiral arms in disk galaxies we performed a series of N-body simulations with 1.2 and 8 million particles. The initial conditions were chosen to follow Kuijken-Dubinski models. In this work we present the results of a sub-sample of our simulations in which we experiment with different disk central radial velocity dispersion and the disk scale height.

  12. Dynamical effect of gas on spiral pattern speed in galaxies

    CERN Document Server

    Ghosh, Soumavo

    2016-01-01

    In the density wave theory of spiral structure, the grand-design two-armed spiral pattern is taken to rotate rigidly in a galactic disc with a constant, definite pattern speed. The observational measurement of the pattern speed of the spiral arms, though difficult, has been achieved in a few galaxies such as NGC 6946, NGC 2997, and M 51 which we consider here. We examine whether the theoretical dispersion relation permits a real solution for wavenumber corresponding to a stable wave, for the observed rotation curve and the pattern speed values. We find that the disc when treated to consist of stars alone, as is usually done in literature, does not generally support a stable density wave for the observed pattern speed. Instead the inclusion of the low velocity dispersion component, namely, gas, is essential to obtain a stable density wave. Further, we obtain a theoretical range of allowed pattern speeds that correspond to a stable density wave at a certain radius, and check that for the three galaxies consider...

  13. Gastric wall thickening on spiral CT after subtotal gastrectomy for gastric cancer: comparision between recurrent caner and benign thickening

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chang Sook; Choi, Jong Cheol; Yoon, Sung Kuk; Kim, Jae Ik; Oh, Jong Young; Kang, Myung Jin; Lee, Ki Nam; Nam, Kyuung Jin [Donga Univ. College of Medicine, Pusan (Korea, Republic of)

    2000-12-01

    To determine the features revealed by two-phase spiral CT scanning useful for differential diagnosis between recurrent cancer and benign wall thickening in patients who have undergone subtotal gastrectomy for stomach cancer. We retrospectively reviewed 25 cases in which wall thickening of more than 1cm in the remnant stomach after subtotal gastrectomy was revealed by two-phase spiral CT scanning. All cases were confirmed: 11 were recurrent cancer, and in 14, benign wall thickening was demonstrated. We analyzed the CT findings including maximal thickness of the gastric wall, patterns of wall thickening, degree of contrast enhancement seen during the arterial and portal phases, and the presence of perigastric strands. Maximal wall thickness was classified as either more or less than 15mm, and as either focal or diffuse. We also determined whether lymphadenopathy was present. Mean maximal gastric wall thickness was 18.4mm in the recurrent cancer group ({sup g}roup A{sup )} and 12.6mm in the benign group ({sup g}roup B{sup )}. The gastric wall was thicker than 15mm in 10 of 11 group A cases and in 3 of 14 in group B; wall thickening was focal (n=3) or diffuse (n=8) in group A, and focal (n=13) or diffuse (n=1) in group B, while the enhancement patterns seen during the arterial and portal phase, respectively, were high/high (n=8), low/high (n=1) and low/low (n=2) in group A, and low/low (n=7), low/high (n=4), high/low (n=1) and high/high (n=2) in group B. Perigastric strands were observed in nine cases in group A, but in none in group B, while lymphadenopathy was combined with wall thickening in seven group A cases but in none of those in group B. In patients who have undergone subtotal gastrectomy for gastric cancer, two-phase spiral CT findings including maximal thickness of the gastric wall, patterns of wall thickening, degree of contrast enhancement seen during the arterial and portal phase, the presence of perigastric strands, and lymphadenopathy are useful for

  14. Severity of acute pulmonary embolism: evaluation of a new spiral CT angiographic score in correlation with echocardiographic data

    Energy Technology Data Exchange (ETDEWEB)

    Mastora, Ioana; Remy-Jardin, Martine; Masson, Pascal; Remy, Jacques [Department of Radiology, University Center Hospital Calmette, Boulevard Jules Leclerc, 59037 Lille Cedex (France); Medical Research Group ' ' Equipe d' Accueil no. 2682' ' , Boulevard Jules Leclerc, 59037 Lille Cedex (France); Galland, Eric; Bauchart, Jean-Jacques [Department of Cardiology, University Center Cardiology Hospital; Boulevard Jules Leclerc, 59037 Lille Cedex (France); Delannoy, Valerie [Department of Medical Statistics, University of Lille, Place de Verdun, 59037 Lille Cedex (France)

    2003-01-01

    The purpose of this study was to investigate whether the severity of acute pulmonary embolism (PE) could be quantitatively assessed with spiral CT angiography (SCTA). Thirty-six consecutive patients without underlying cardiopulmonary disease and high clinical suspicion of PE underwent prospectively thin-collimation SCTA and echocardiography at the time of the initial diagnosis (T0) and after initial therapy (T1; mean interval of time T1-T2: 32 days). The CT severity score was based on the percentage of obstructed surface of each central and peripheral pulmonary arterial section using a 5-point scale (1: <25%; 2: 25-49%; 3: 50-74%; 4: 75-99%; 5: 100%). The sum of the detailed scores attributed to 5 mediastinal, 6 lobar and 20 segmental arteries per patient led to the determination of central, peripheral and global CT severity scores and subsequent determination of percentages of obstruction of the pulmonary circulation. Echocardiographic severity criteria included the presence of signs of acute cor pulmonale and/or systolic pulmonary hypertension (>40 mm Hg). The SCTA depicted acute PE in all patients at T0 with complete resolution of endovascular clots in 10 patients at T1. At T0, the mean percentage of obstruction of the pulmonary arterial bed was significantly higher in the 22 patients with echocardiographic signs of severity (56{+-}13 vs 28{+-}32%; p<0.001). A significant reduction in the mean percentage of pulmonary artery obstruction was observed in the 19 patients with resolution of echocardiographic criteria of severity between T0 and T1 T0: 57{+-}14%; T1: 7{+-}11%; p<0.001. The threshold value for severe PE on CT angiograms was 49% (sensitivity: 0.773; specificity: 0.214). The mean ({+-}SD) pulmonary artery pressure was significantly higher in the 26 patients with more than 50% obstruction of the pulmonary artery bed (45{+-}15 mm Hg) than in the 10 patients with less than 50% obstruction of pulmonary artery bed at T0 (31{+-}11 mm Hg; p<0.01). The CT

  15. 螺旋CT 在消化道穿孔中的诊断价值%Diagnostic value of spiral CT for gastrointestinal perforation

    Institute of Scientific and Technical Information of China (English)

    周晓秋; 王宝春; 操啸; 刘云峰

    2014-01-01

    目的:分析C T在消化道穿孔中的诊断价值。方法回顾性分析51例经手术证实的消化道穿孔病例,术前行立位腹部平片检查者41例,腹部C T扫描者51例,比较两种检查方法在消化道穿孔中的诊断价值。结果41例X线片检出游离气体26例,CT检出50例,CT检出率高于普通X线检查( P <0.05)。CT显示腹内游离气体呈新月状或小气泡影(50例),胃肠穿孔处周围局限性积液或蜂窝织炎(34例),阑尾周围脓肿(3例),肠梗阻(5例),胃肠壁增厚(25例),胃肠壁肿块(2例),胃肠壁缺损(4例),腹水(30例)。C T对穿孔病因的诊断符合率为68.6%(35/51),对穿孔部位的诊断符合率为88.2%(45/51)。结论螺旋C T诊断胃肠道穿孔是一种有效的检查方法,且对穿孔部位和病因的诊断也具有重要价值。%Objective To analyze the value of Spiral CT in the diagnosis of gastrointestinal (GI) tract perforation .Meth-ods 51 cases that had gastrointestinal tract perforation confirmed by surgery were retrospectively studied in this research . All these cases had CT examination and 41 cases had abdominal plain film examination on the same day .Moreover ,the di-agnostic value of the two methods in gastrointestinal (GI) tract perforation was compared .Results Free air was only shown in 26 cases out of 41 by X-ray examination ,but 50 cases out of 51 by Spiral CT examination .CT examination detec-tion rate was higher than ordinary X-ray examination ( P<0 .05) .The direct CT sign of gastrointestinal tract perforation was“crescent”or“bubble”sign formed by the air within peritoneal cavity ,which were detected in 50 cases .The other find-ings were showing the localized fluid or cellulites adjacent to the gastrointestinal tract perforation (n=34) and appendiceal abscess (n=3) .5 cases were associated with bowel obstruction ,25 cases with gastrointestinal wall thickening ,2 cases

  16. Prospectively ECG-triggered high-pitch spiral acquisition for coronary CT angiography using dual source CT: technique and initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Lell, Michael; Anders, Katharina [University of Erlangen, Diagnostic Radiology, Erlangen (Germany); Marwan, Mohamed; Schepis, Tiziano; Pflederer, Tobias; Kuettner, Axel; Ropers, Dieter; Daniel, Werner G.; Achenbach, Stephan [University of Erlangen, Department of Cardiology, Erlangen (Germany); Flohr, Thomas [CT Division, Siemens Healthcare, Forchheim (Germany); Eberhard-Karls-University, Institute of Diagnostic Radiology, Tuebingen (Germany); Allmendinger, Thomas; Thierfelder, Carsten [CT Division, Siemens Healthcare, Forchheim (Germany); Kalender, Willi; Ertel, Dirk [University of Erlangen, Institute of Medical Physics, Erlangen (Germany)

    2009-11-15

    We evaluated radiation exposure and image quality of a new coronary CT angiography protocol, high-pitch spiral acquisition, using dual source CT (DSCT). Coronary CTA was performed in 25 consecutive patients with a stable heart rate of 60 bpm or less after premedication, using 2 x 128 0.6-mm sections, 38.4-mm collimation width and 0.28-s rotation time. Tube settings were 100 kV/320 mAs and 120 kV/400 mAs for patients below and above 100-kg weight, respectively. Data acquisition was prospectively ECG-triggered at 60% of the R-R interval using a pitch of 3.2 (3.4 for the last 10 patients). Images were reconstructed with 75-ms temporal resolution, 0.6-mm slice thickness and 0.3-mm increment. Image quality was evaluated using a four-point scale (1 = excellent, 4 = unevaluable). Mean range of data acquisition was 113 {+-} 22 mm, mean duration was 268 {+-} 23 ms. Of 363 coronary artery segments, 327 had an image quality score of 1, and only 2 segments were rated as ''unevaluable''. Mean dose-length product (DLP) was 71 {+-} 23 mGy cm, mean effective dose was 1.0 {+-} 0.3 mSv (range 0.78-2.1 mSv). For 21 patients with a body weight below 100 kg, mean DLP was 63 {+-} 5 mGy cm (0.88 {+-} 0.07 mSv; range 0.78-0.97 mSv). Prospectively ECG-triggered high-pitch spiral CT acquisition provides high and stable image quality at very low radiation dose. (orig.)

  17. Detection of small hypervascular hepatocellular carcinomas in cirrhotic patients: comparison of superparamagnetic iron oxide-enhanced MR imaging with dual-phase spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Min [Seoul National University Hospital, Seoul (Korea, Republic of); Kim, In Hwan; Kwak, Hyo Sung; Youk, Ji Hyun; Han, Young Min; Kim, Chong Soo [Chonbuk National University, Chounju (Korea, Republic of)

    2003-03-01

    To compare the performance of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging at 1.5T and dual-phase spiral computed tomography (CT) for the depiction of small hypervascular hepatocellular carcinomas (HCCs). Forty-three patients with 70 small nodular HCCs (5- 20 mm; mean, 13.7 mm) were examined. Diagnosis was based on the results of surgical biopsy in 22 patients and by the combined assessment of MR imaging, lipiodol CT, alpha feto-protein levels, and angiographic findings in 21. MR imaging consisted of respiratory-triggered turbo spin-echo T2-weighted imaging, T1- weighted fast low-angle shot, and T2* -weighted fast imaging with steady-state precession imaging before and after SPIO enhancement. CT imaging was performed with 5-mm collimation and 1:1.4 pitch, and began 30 and 65 secs after the injection of 150 mL of contrast medium at a rate of 3 mL/sec. Two blinded observers reviewed all images independently on a segment-by-segment basis. Diagnostic accuracy was evaluated using receiver operating characteristics (ROC) analysis. The mean areas (Az) under the ROC curves were 0.85 for SPIOenhanced MR imaging and 0.79 for dual-phase spiral CT (p < .05). The mean sensitivity of SPIO-enhanced MR imaging was significantly higher than that of CT (p < .05), i.e. 70.6% for MR imaging and 58.1% for CT. MR imaging had higher false-positive rates than dual-phase spiral CT, but the difference was not statistically significant (3.7% vs 3.3%) (p > .05). SPIO-enhanced MR imaging is more sensitive than dual-phase spiral CT for the depiction of small hypervascular hepatocellular carcinomas.

  18. Comparison of Multislice Spiral CT Dual Phase and Somatosatatin Receptor Scintigraphy in the Diagnosis of Pancreas Neuroendocrine Tumors.

    Science.gov (United States)

    2016-06-10

    Objective To compare the sensitivity of multislice spiral CT dual phase and somatosatatin receptor scintigraphy (SRS) in the diagnosis of pancreas nuroendocrine tumors (pNET). Methods Totally 28 patients with pathologically confirmed pNET recieved both CT dual phase contrast and SRS and the results were compared. Results Of these 28 pNET patients,26 (92.8%) were accurately diagnosed by CT dual-phase scan and 20 (71.4%) by SRS (P=0.031).In the functioning pNET cases,the diagnosis sensitivity of CT dual phase scan and SRS was 94.1% (16/17)and 58.8% (10/17)(P=0.218). In the non-functioning pNET cases,the sensitivity was 90.9% (10/11) and 90.9% (10/11) (P=0.740).Diagnostic sensitivity of CT dual phase scan and SRS for pNET without metastasis was 90.4% (19/21) and 57.1% (12/21) (P=0.125).The sensitivity for pNET with metastasis was 100%(7/7)and 100% (7/7). Corresponding to the pathological grading,the diagnostic sensitivity of CT dual phase scanning and SRS was 84.6% (11/13) and 53.8% (7/13) for G1,100% (12/12) and 83.3% (10/12) for G2,and 100% (3/3) and 100% (3/3) for G3. The diagnostic sensitivity of CT dual phase scan and SRS for pNET with diameter less than or equal to 2.0 cm was 94.7% (18/19) and 52.6% (10/19) (P=0.008). For pNET with diameter more than 2.0 cm,the sensitivity was 92.8% (13/14) and 100% (14/14). Conclusions Compared with SRS,dual phase CT scan is more sensitive in diagnosing pNET,especially for those in lower pathological stages. For lesions sized less than or equal to 2.0 cm,SRS should be combined with other imaging examinations to minimize false negative results.

  19. Quantitative perfusion imaging by multi-slice CT in stroke patients; Quantitative Perfusionsbildgebung mittels Mehrschicht-Spiral-CT bei Patienten mit akuter zerebraler Ischaemie

    Energy Technology Data Exchange (ETDEWEB)

    Bohner, G.; Klingebiel, R. [Humboldt-Universitaet, Berlin (Germany). Universitaetsklinikum Charite, Abt. Neuroradiologie; Humboldt-Universitaet, Berlin (Germany). Universitaetsklinikum Charite, Inst. fuer Radiologie; Foerschler, A.; Lehmann, R. [Humboldt-Universitaet, Berlin (Germany). Universitaetsklinikum Charite, Abt. Neuroradiologie; Hamm, B. [Humboldt-Universitaet, Berlin (Germany). Universitaetsklinikum Charite, Inst. fuer Radiologie

    2003-06-01

    Objectives: Evaluation of a parametric deconvolution algorithm (DA) in the diagnostic assessment of stroke patients by multislice spiral computed tomography (MS-CT). Material and Methods: 52 patients (age range 34-89 years) with clinically suspected acute ischemia of one hemisphere and no infarct demarcation on plain cerebral CT underwent CT perfusion (CTP), performed on average 3.4 hours after the onset of symptoms by using MS-CT (4 x 8 mm scan volume). Using a DA-based software module, perfusion images of the cerebral blood perfusion (CBP), cerebral blood volume (CBV) and mean transit time (MTT) were calculated and assessed by two readers for visually apparent perfusion abnormalities. Amount and extension of perfusion disturbances were measured and correlated with the outcome. Results: Of 44 patients, in whom perfusion maps could be generated, territorial infarction was confirmed by follow-up in 22 subjects. With a sensitivity of 95% ischemia could be detected on MTT-maps (CBP 91%, CBV 77%). Specificity was highest (100%) for CBV-maps. Patients with infarction showed significant (p<0.001) reduction of CBP (10.7 vs. 38.3 ml/100 ml/min), CBV (1.3 vs. 2.3 ml/100 ml) and prolongation of MTT (12.3 vs. 4.3 s) compared to the contralateral hemisphere, whereas in patients without infarction no significant changes were found. Extension of CBV reduction showed the best correlation (r=0.82) with final infarct volume. Conclusion: The DA-based CTP protocol evaluated in this study is a suitable tool for the early identification and quantification of acute cerebral ischemia. (orig.) [German] Ziel: Evaluation des Einsatzes der Mehrschicht-Spiral-CT (MS-CT) in Kombination mit einem parametrischen Dekonvolutionsalgorithmus (DA) zur zerebralen Perfusionsbildgebung bei Patienten mit klinischen Zeichen einer akuten territorialen Ischaemie. Material und Methoden: 52 Patienten (Altersspanne 34-89 Jahre) mit klinischen Zeichen einer akuten territorialen Ischaemie sowie fehlender

  20. Characterization of liver lesions with mangafodipir trisodium-enhanced MR imaging: multicenter study comparing MR and dual-phase spiral CT

    NARCIS (Netherlands)

    M. Oudkerk (Matthijs); C.G. Torres; B. Song; M. Konig; J. Grimm; J. Fernandez-Cuadrado; B. op de Beeck; M. Marquardt; P. van Dijk (Pieter); J.C. de Groot (Jan Cees)

    2002-01-01

    textabstractPURPOSE: To evaluate whether mangafodipir trisodium (Mn-DPDP)-enhanced magnetic resonance (MR) imaging surpasses dual-phase spiral computed tomography (CT) in differentiating focal liver lesions. MATERIALS AND METHODS: One hundred forty-five patients who had or were sus

  1. Characterization of liver lesions with mangafodipir trisodium-enhanced MR imaging : Multicenter study comparing MR and dual-phase spiral CT

    NARCIS (Netherlands)

    Oudkerk, M; Torres, CG; Song, B; Konig, M; Fernandez-Cuadrado, J; de Beeck, BO; Marquardt, M; van Dijk, P.; de Groot, JC

    2002-01-01

    PURPOSE: To evaluate whether mangafodipir trisodium (Mn-DPDP)- enhanced magnetic resonance (MR) imaging surpasses dual-phase spiral computed tomography (CT) in differentiating focal liver lesions. MATERIALS AND METHODS: One hundred forty-five patients who had or were suspected of having focal liver

  2. Assessment of pulmonary function using pixel indexes of multiple-slice spiral CT low-dose two-phase scanning in chronic obstructive pulmonary disease

    Institute of Scientific and Technical Information of China (English)

    张利华

    2012-01-01

    Objective To explore the values of pixel indexes (PI) with multiple-slice spiral CT low-dose two-phase scanning for assessing the pulmonary function in chronic obstructive pulmonary disease(COPD) . Methods Thirty-six patients with COPD (COPD group) and 30 healthy people(control group) underwent pulmonary

  3. Characterization of liver lesions with mangafodipir trisodium-enhanced MR imaging: multicenter study comparing MR and dual-phase spiral CT

    NARCIS (Netherlands)

    M. Oudkerk (Matthijs); C.G. Torres; B. Song; M. Konig; J. Grimm; J. Fernandez-Cuadrado; B. op de Beeck; M. Marquardt; P. van Dijk (Pieter); J.C. de Groot (Jan Cees)

    2002-01-01

    textabstractPURPOSE: To evaluate whether mangafodipir trisodium (Mn-DPDP)-enhanced magnetic resonance (MR) imaging surpasses dual-phase spiral computed tomography (CT) in differentiating focal liver lesions. MATERIALS AND METHODS: One hundred forty-five patients who had or were sus

  4. Characterization of liver lesions with mangafodipir trisodium-enhanced MR imaging : Multicenter study comparing MR and dual-phase spiral CT

    NARCIS (Netherlands)

    Oudkerk, M; Torres, CG; Song, B; Konig, M; Fernandez-Cuadrado, J; de Beeck, BO; Marquardt, M; van Dijk, P.; de Groot, JC

    2002-01-01

    PURPOSE: To evaluate whether mangafodipir trisodium (Mn-DPDP)- enhanced magnetic resonance (MR) imaging surpasses dual-phase spiral computed tomography (CT) in differentiating focal liver lesions. MATERIALS AND METHODS: One hundred forty-five patients who had or were suspected of having focal liver

  5. Digital volume tomography (DVT) and multislice spiral CT (MSCT). An objective examination of dose and image quality; Digitale Volumentomografie (DVT) und Mehrschicht-Spiral-CT (MSCT). Eine objektive Untersuchung von Dosis und Bildqualitaet

    Energy Technology Data Exchange (ETDEWEB)

    Kyriakou, Y.; Kolditz, D.; Langner, O.; Krause, J.; Kalender, W. [Erlangen-Nuernberg Univ. (Germany). Inst. fuer Medizinische Physik

    2011-02-15

    Purpose: In the last five years digital volume tomographs (DVT) have found their way into the diagnostic imaging of the facial skull. In this study both the image quality and dose of DVT and multislice spiral CT (MSCT) in this field of application were investigated using established physical methods for CT. Materials and Methods: Measurements on DVT scanners of various manufacturers and on a modern MSCT scanner were performed. The investigation was based on equivalent dose levels for both modalities (CT dose index, CTDI). For this purpose, the dose was measured with an ionization chamber in a cylindrical PMMA phantom. For the evaluation of image quality, the spatial resolution, contrast and noise were investigated with phantoms established for CT. Results: MSCT exhibited spatial resolution values of 1.0 to 1.6 lp/mm, while DVT provided resolution between 0.6 and 1.0 lp/mm only. Thus, MSCT offered similar or better resolution at an equivalent dose. For soft tissue resolution, DVT showed significant image artifacts. MSCT yielded higher homogeneity and no significant artifacts, and the contrast steps of the phantom were more verifiable. The different DVT devices, from image intensifiers to modern flat-detector (FD) devices, showed significant differences in favor of the FD devices. Conclusion: For medium and high contrast applications (teeth/bones), DVT scanners can be an alternative to MSCT at comparable radiation exposure. However, MSCT offers advantages in terms of constantly good and controlled image quality with significantly more flexible scan parameters at a constant or lower dose and should therefore be given preference. (orig.)

  6. Dynamic perfusion CT in brain tumors.

    Science.gov (United States)

    Yeung, Timothy Pok Chi; Bauman, Glenn; Yartsev, Slav; Fainardi, Enrico; Macdonald, David; Lee, Ting-Yim

    2015-12-01

    Dynamic perfusion CT (PCT) is an imaging technique for assessing the vascular supply and hemodynamics of brain tumors by measuring blood flow, blood volume, and permeability-surface area product. These PCT parameters provide information complementary to histopathologic assessments and have been used for grading brain tumors, distinguishing high-grade gliomas from other brain lesions, differentiating true progression from post-treatment effects, and predicting prognosis after treatments. In this review, the basic principles of PCT are described, and applications of PCT of brain tumors are discussed. The advantages and current challenges, along with possible solutions, of PCT are presented.

  7. Jaws for a spiral-tooth whorl: CT images reveal novel adaptation and phylogeny in fossil Helicoprion.

    Science.gov (United States)

    Tapanila, Leif; Pruitt, Jesse; Pradel, Alan; Wilga, Cheryl D; Ramsay, Jason B; Schlader, Robert; Didier, Dominique A

    2013-04-23

    New CT scans of the spiral-tooth fossil, Helicoprion, resolve a longstanding mystery concerning the form and phylogeny of this ancient cartilaginous fish. We present the first three-dimensional images that show the tooth whorl occupying the entire mandibular arch, and which is supported along the midline of the lower jaw. Several characters of the upper jaw show that it articulated with the neurocranium in two places and that the hyomandibula was not part of the jaw suspension. These features identify Helicoprion as a member of the stem holocephalan group Euchondrocephali. Our reconstruction illustrates novel adaptations, such as lateral cartilage to buttress the tooth whorl, which accommodated the unusual trait of continuous addition and retention of teeth in a predatory chondrichthyan. Helicoprion exemplifies the climax of stem holocephalan diversification and body size in Late Palaeozoic seas, a role dominated today by sharks and rays.

  8. Dynamic Bowtie for Fan-beam CT

    CERN Document Server

    Liu, Fenglin; Cong, Wenxiang; Hsieh, Scott; Pelc, Norbert

    2013-01-01

    A bowtie is a filter used to shape an x-ray beam and equalize its flux reaching different detector channels. For development of spectral CT with energy-discriminative photon-counting (EDPC) detectors, here we propose and evaluate a dynamic bowtie for performance optimization based on a patient model or a scout scan. Our dynamic bowtie modifies an x-ray beam intensity profile by mechanical rotation and adaptive adjustment of the x-ray source flux. First, a mathematical model for dynamic bowtie filtering is established for an elliptical section in fan-beam geometry, and the contour of the optimal bowtie is derived. Then, numerical simulation is performed to compare the performance of the dynamic bowtie in the cases of an ideal phantom and a realistic cross-section relative to the counterparts without any bowtie and with a fixed bowtie respectively. Our dynamic bowtie can equalize the expected numbers of photons in the case of an ideal phantom. In practical cases, our dynamic bowtie can effectively reduce the dy...

  9. Difference of contrast enhancement characteristics of hepatic hemangiomas according to lesion size on two-phase spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Sung Hye; Yoon, Suk Kwon; Yang, Dal Mo; Yoon, Myung Hwan; Kim, Hak Soo; Kim, Hyung Sik; Chung, Jin Woo [Chungang Gil Hospital, Incheon (Korea, Republic of)

    1998-06-01

    The purpose of this study is to determine the different of enhancement patterns of hepatic hemangioma according to the lesion size, using dual-phase spiral CT. Fifty-nine lesions in 45 patients with hepatic hemangiomas were subjected to spiral CT. According to size, the lesions were divided into two groups (<2.5 cm : n=34;> {>=} 2.5 cm : n=25). The enhancement patterns of the lesions were classified as one of four types (homogeneous hyperdense, peripheral hyperdense, central hyperdense, peripheral hyperdense, central hyperdense, or hypodense) during the early phase, and as one of five types (homogeneous hyperdense, peripheral hyperdense, central hyperdense, hypodense of isodense) during the delayed phase. We evaluated differences in enhancement patterns during the early and delayed phase according to lesion size. During the early phase, the enhancement patterns of lesions large than 2.5 cm were peripheral hyperdense (96%) or homogeneous hyperdense (4%); those of less than 2.5 cm were peripheral hyperdense (53%), homogenous hyperdense (26%), hypodense (18%), or central hyperdense (3%). Thus, hemangiomas in these two groups usually showed a peripheral enhancement patterns were more common. During the delayed phase, the enhancement patterns of lesions larger than 2.5 cm were peripheral hyperdense (3%), or isodense (3%). Thus, the enhancement patterns of lesions larger than 2.5 cm showed a homogeneous enhancement pattern. The enhancement patterns of hepatic hemangiomas differ according to lesion size. A knowledge of these differences is helpful in the diagnosis of hepatic hemangioma. (author). 16 refs., 2 tabs., 3 figs.

  10. Contrast enhancement characteristics of hepatocellular carcinoma according to the tumor size on two-phase scan with spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jee Eun; Yang, Dai Mo; Yoon, Myung Hwan; Chun, Seok; Kim, Hyung Sik; Chung, Hyo Seon; Lee, Young Seok [Chungang Gil Hospital, Incheon (Korea, Republic of)

    1996-01-01

    To determine the enhancing patterns of hepatocellular carcinoma(HCC) and the difference of enhancing patterns according to the tumor size, using spiral CT. We reviewed 213 lesions in 76 patients who had been clinically or histopathologically diagnosed as HCC sufferer. The tumors were divided into three groups, according to size(<3 cm, 3-5 cm and >5 cm). The enhancing patterns of tumor and capsule in the early and delayed phase were analysed. The enhancing patterns of the tumor were divided into five types(high, peripheral high, mixed, iso and low attenuation) in the early phase and four types(contral high, mixed, iso, and low attenuation) in the delayed phase. The enhancing patterns of the capsule were divided into three types such as iso, low and high attenuation. High attenuating lesions in the early phase were as follows; below 3 cm, 72%:3-5 cm, 60%:above 5 cm, 49%. Mixed attenuating lesions in the early phase were as follows;below 3 cm, 1%;3-5 cm, 22%;above 5 cm, 36%. Thus, most Hx were high attenuation type in the early phase, but as the tumor became larger, less high attenuation and more mixed attenuation was demonstrated(p<0.01). There was no difference of enhancing patterns according to the tumor size in peripheral high, iso and low-attenuating lesions. In the delayed phase most of the hepatomas appeared as totally hypodense lesions. For capsules, the results were as follows; below 3 cm, 20%:3-5 cm, 58%: above 5 cm, 73%. As the tumors became larger, more capsules were demonstrated(p<0.01). The capsules were visualized as iso or low attenuating rum in the early phase and high attenuating rim in the delayed phase. To determine the enhancing patterns of HCC using spiral CT is considered to be helpful in the diagnosis of HCC.

  11. Galactic masers: kinematics, spiral structure and the disk dynamic state

    CERN Document Server

    Rastorguev, A S; Dambis, A K; Utkin, N D; Bajkova, A T; Bobylev, V V

    2016-01-01

    We investigate the kinematics of 131 Milky-Way masers associated with star-forming regions and with trigonometric parallaxes measured by Very Large Baseline Radio Interferometry. We developed a new algorithm for computing the structural and kinematic parameters of the Galactic disk, which implements the currently most comprehensive version of the statistical-parallax technique. To take into account the variation of the form and size of the ellipsoid of residual velocities as a function of Galactocentric distance, we assume that radial velocity dispersion is related to disk surface density and apply the Jeans hydrodynamic equations. We compute the Galactic rotation curve over the Galactocentric distance interval from 3 to 14 kpc and find the local circular rotation velocity to be 243 +/- 10 km/s, and we also determine a full set of kinematical parameters, including the parameters of the four-armed spiral pattern with the pitch angle i ~ -10.45 +/- 0.30 deg. The galactocentric distance is found to be R0 = 8.40 ...

  12. Detection of pulmonary metastases with pathological correlation: effect of breathing on the accuracy of spiral CT. Editor`s note

    Energy Technology Data Exchange (ETDEWEB)

    Coakley, F.V. [Abdominal Imaging Section, Department of Radiology, University of California, San Francisco, CA (United States); Cohen, M.D. [Department of Radiology, Riley Hospital for Children, Indianapolis, IN (United States); Waters, D.J. [Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN (United States); Davis, M.M. [Department of Pathology, Riley Hospital for Children, Indianapolis, IN (United States); Karmazyn, B. [Department of Radiology, Riley Hospital for Children, Indianapolis, IN (United States); Gonin, R. [Division of Biostatistics, Department of Medicine, Riley Hospital for Children, Indianapolis, IN (United States); Hanna, M.P. [Division of Biostatistics, Department of Medicine, Riley Hospital for Children, Indianapolis, IN (United States)

    1997-07-01

    Background. CT of the chest for suspected pulmonary metastases in adults is generally performed using a breath-hold technique. The results may not be applicable to young children in whom breath-holding may be impossible. Objective. Determine the effect of breathing on the accuracy of pulmonary metastasis detection by spiral CT (SCT). Materials and methods. Prior to euthanasia four anesthetized dogs with metastatic osteosarcoma underwent SCT with a collimation of 5 mm and a pitch of 2, during both induced breath-hold and normal quiet breathing. Images were reconstructed as contiguous 5-mm slices. Macroscopically evident metastases were noted at postmortem. Hard-copy SCT images were reviewed by ten radiologists, each of whom circled all suspected metastases. SCT images were compared with postmortem results to determine true and false positives. Results. The pathologist identified 132 macroscopically evident pulmonary metastases. For metastasis detection, there was no significant difference between breath-hold SCT and breathing SCT. Conclusion. In our animal model, SCT can be performed during normal resting breathing without significant loss of accuracy in the detection of pulmonary metastases. (orig.). With 3 tabs.

  13. The case of Serbia/Yugoslavia: an analysis through spiral dynamics.

    Science.gov (United States)

    Stambolovic, Vuk

    2002-01-01

    Yugoslavia and later Serbia have puzzled the world since the early 1990s. This article presents a study based on the principles of spiral dynamics that were used to analyze the transformation of South Africa. According to spiral dynamics, Yugoslavia under the joint influence of nationalists and retro-socialists regressed to the egocentric and exploitative level of psychosocial existence and, in spite of recent political changes, has maintained the same centre of gravity. Although its political structure has changed, nationalist and retro-socialist values remain dominant in the cultural domain and in the domain of self. Yugoslavia/Serbia desperately needs the new dynamic process of development. Priorities are the establishment of a hierarchy of authority, self-confrontation and development of widely based enthusiasm. These could lead Serbia to become responsible and mature.

  14. Eventful evolution of giant molecular clouds in dynamically evolving spiral arms

    Science.gov (United States)

    Baba, Junichi; Morokuma-Matsui, Kana; Saitoh, Takayuki R.

    2017-01-01

    The formation and evolution of giant molecular clouds (GMCs) in spiral galaxies have been investigated in the traditional framework of the combined quasi-stationary density wave and galactic shock model. In this study, we investigate the structure and evolution of GMCs in a dynamically evolving spiral arm using a three-dimensional N-body/hydrodynamic simulation of a barred spiral galaxy at parsec-scale resolution. This simulation incorporated self-gravity, molecular hydrogen formation, radiative cooling, heating due to interstellar far-ultraviolet radiation, and stellar feedback by both H II regions and Type II supernovae. In contrast to a simple expectation based on the traditional spiral model, the GMCs exhibited no systematic evolutionary sequence across the spiral arm. Our simulation showed that the GMCs behaved as highly dynamic objects with eventful lives involving collisional build-up, collision-induced star formation, and destruction via stellar feedback. The GMC lifetimes were predicted to be short, only a few tens of millions years. We also found that at least at the resolutions and with the feedback models used in this study, most of the GMCs without H II regions were collapsing, but half of the GMCs with H II regions were expanding owing to the H II-region feedback from stars within them. Our results support the dynamic and feedback-regulated GMC evolution scenario. Although the simulated GMCs were converging rather than virial equilibrium, they followed the observed scaling relationship well. We also analysed the effects of galactic tides and external pressure on GMC evolution and suggested that GMCs cannot be regarded as isolated systems since their evolution in disc galaxies is complicated because of these environmental effects.

  15. Eventful Evolution of Giant Molecular Clouds in Dynamically Evolving Spiral Arms

    Science.gov (United States)

    Baba, Junichi; Morokuma-Matsui, Kana; Saitoh, Takayuki R.

    2016-09-01

    The formation and evolution of giant molecular clouds (GMCs) in spiral galaxies have been investigated in the traditional framework of the combined quasi-stationary density wave and galactic shock model. In this study, we investigate the structure and evolution of GMCs in a dynamically evolving spiral arm using a three-dimensional N-body/hydrodynamic simulation of a barred spiral galaxy at parsec-scale resolution. This simulation incorporated self-gravity, molecular hydrogen formation, radiative cooling, heating due to interstellar far-ultraviolet radiation, and stellar feedback by both HII regions and Type-II supernovae. In contrast to a simple expectation based on the traditional spiral model, the GMCs exhibited no systematic evolutionary sequence across the spiral arm. Our simulation showed that the GMCs behaved as highly dynamic objects with eventful lives involving collisional build-up, collision-induced star formation, and destruction via stellar feedback. The GMC lifetimes were predicted to be short, only a few tens of millions years. We also found that, at least at the resolutions and with the feedback models used in this study, most of the GMCs without HII regions were collapsing, but half of the GMCs with HII regions were expanding owing to the HII-region feedback from stars within them. Our results support the dynamic and feedback-regulated GMC evolution scenario. Although the simulated GMCs were converging rather than virial equilibrium, they followed the observed scaling relationship well. We also analysed the effects of galactic tides and external pressure on GMC evolution and suggested that GMCs cannot be regarded as isolated systems since their evolution in disc galaxies is complicated because of these environmental effects.

  16. Aortic non communicating dissections. A study with helical CT; Studio dell'ematoma intramurale aortico. Aspetti con Tomografia Computerizzata spirale

    Energy Technology Data Exchange (ETDEWEB)

    Midiri, M.; Strada, A.; Stabile Ianora, A.A.; Rotondo, A.; Angelelli, G. [Bari Univ., Bari (Italy). Dipt. di Medicina Interna e Medicina Pubblica, Sez. di Diagnostica per Immagini; Scialpi, M. [Ospedale SS. Annunziata, Taranto (Italy); D' Agostino, D.; De Luca Tupputi Schinosa, L. [Bari Univ., Bari (Italy). Dipt. Emergenze Trapianto d' Organo, Sez. di Cardiochirurgia

    2000-09-01

    The evaluate the signs of aortic intramural hematoma with helical CT and the diagnostic role of this technique in patients with this condition. It was reviewed the CT findings of 396 patients submitted to emergency examinations for suspected aortic dissection from 1995 to 1999. Only 18 patients (6 women and 12 men) had CT signs of aortic intramural hematoma. Helical CT studies were carried out with the following parameters: slice thickness 10 mm, reconstruction index 10, feed 1.5 mm, conventional algorithm with minimum values of 130 kV and 125mA. All patients were examined with dynamic contrast-enhanced CT, before and after a power injection of 130 mL ionic contrast material. It was studied: hematoma localization and longitudinal extension; thickness and density of aortic wall; presence and location of intimal calcifications; integrity of intimal wall; hemo mediastinum and/or hemo thorax. Aortic wall thickening appeared as a high density crescent-shaped area at baseline CT and had low density on enhanced images in all patients. Thickening was eccentric in 14/18 patients and concentric in 4/18 only; it always exceeded 4 mm. It was found some intimal calcifications in 8 patients and hemo thorax and/or hemo mediastinum in 9 patients. A patient with type A hematoma died of cardiac tamponade a few hours after CT diagnosis. Six patients (5 type B and 1 type A) underwent anti-hypertensive treatment and radiological follow-up. Eleven patients (6 type A and 5 type B) underwent prosthesis replacement and 5 of them (3 type A and 2 type B) died of postoperative complications. In the 5 type B patients surgery was performed because of treatment-resistant pain and of the onset of ischemic complications to abdominal organs caused by involvement of the main collateral branches of the aorta. One patient with type A hematoma was submitted to drug treatment because it was judged unresectable. Intramural hematoma of the aorta is a distinct pathological entity, which should not be

  17. Departures From Axisymmetric Morphology and Dynamics in Spiral Galaxies

    CERN Document Server

    Kornreich, D A; Lovelace, R V E; Van Zee, L; Kornreich, David A.; Haynes, Martha P.; Zee, Liese van

    2000-01-01

    New HI synthesis data have been obtained for six face-on galaxies with the Very Large Array. These data and reanalyses of three additional data sets make up a sample of nine face-on galaxies analyzed for deviations from axisymmetry in morphology and dynamics. This sample represents a subsample of galaxies already analyzed for morphological symmetry properties in the R-band. Four quantitative measures of dynamical nonaxisymmetry are compared to one another and to the quantitative measures of morphological asymmetry in HI and R-band to investigate the relationships between nonaxisymmetric morphology and dynamics. We find no significant relationship between asymmetric morphology and most of the dynamical measures in our sample. A possible relationship is found, however, between morphology and dynamical position angle differences between approaching and receding sides of the galaxy.

  18. Virtual endoscopy of the upper, central and peripheral airways with multirow detector CT; Virtuelle Endoskopie der oberen, zentralen und peripheren Atemwege mit Mehrzeilen-Spiral-CT

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, H.; Dinkel, H.P.; Thoeny, H.; Vock, P. [Institut fuer Diagnostische Radiologie, Universitaetsspital Bern (Switzerland); Gugger, M. [Abteilung fuer Pneumologie, Universitaetsspital Bern (Switzerland)

    2002-09-01

    Virtual endoscopy of the upper, central and peripheral airways (virtual laryngoscopy or virtual bronchoscopy) produces endoluminal images similar to those of fiberoptic endoscopy. In particular, virtual endoscopy is useful for the assessment of endoluminal tumor extent and tracheobronchial stenosis. Especially since the introduction of multirow detector CT, high-resolution virtual-endoscopic images of the airways can be reconstructed. Either surface rendering or volume rendering can be used for realistic depiction of the airways. Semitransparent color-coded volume rendering is advantageous, because adjacent structures can be displayed in addition to endoluminal views. A major advantage of virtual endoscopy over fiberoptic endoscopy is its non-invasiveness. With virtual endoscopy, even a high-grade stenosis is passable, enabling evaluation of the distal airways. Disadvantages are its inability to depict mucosal color and to perform therapeutic maneuvers. In comparison to other CT display modes, virtual endoscopy allows a more realistic assessment of tracheobronchial stenosis than axial CT slices and multiplanar reformats. Virtual endoscopy of the airways can be used complementary to fiberoptic endoscopy before tracheotomy, stent implantation or lung resection and for post-operative follow-up. In the future, virtual airway endoscopy will be increasingly applied for interactive virtual reality guidance of airway procedures such as bronchoscopy and surgery. (orig.) [German] Die virtuelle Endoskopie der oberen, zentralen und peripheren Atemwege (virtuelle Laryngoskopie oder virtuelle Bronchoskopie) erzeugt eine der fiberoptischen Endoskopie vergleichbare Ansicht und kommt insbesondere zur Diagnostik von tracheobronchialen Stenosen und Tumoren mit endoluminaler Ausdehnung zur Anwendung. Vor allem seit Einfuehrung der Mehrzeilen-Spiral-CT lassen sich qualitativ hochwertige Rekonstruktionen der Atemwege erstellen. Das erfolgt entweder mittels Oberflaechenrekonstruktion

  19. The diagnosis and classification of inguinal and femoral hernia on multisection spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Cherian, P.T. [Good hope Hospital, Rectory road, Sutton Coldfield (United Kingdom)], E-mail: tomcherian@hotmail.co.uk; Parnell, A.P. [Good hope Hospital, Rectory road, Sutton Coldfield (United Kingdom)

    2008-02-15

    Aim: To assess the contribution of high-quality multiplanar reconstructions of the groin from multisection computed tomography (CT) to the accurate diagnosis of inguinal and femoral hernias. Materials and Methods: Twenty-eight patients who had undergone both a contrast-enhanced CT and a herniorrhaphy were identified from hospital records. Seventeen were excluded, as the images did not include the groin area. The remaining 11 images were re evaluated on a workstation without knowledge of the surgical findings and the hernias were identified and classified using the axial data and coronal and sagittal reconstructions. Anatomical structures and radiological details that hindered or aided this classification were recorded. Results: Hernias were identified in nine out of the 11 patients. Of the seven inguinal hernias, six were identified with the correct side recorded in each case. Of the four patients with surgical data that distinguished direct from indirect inguinal hernias, the correct diagnosis was provided in all cases using CT. Of the four patients with a femoral hernia CT was used to correctly classify three. Among the three available planes, the axial was particularly poor for the identification of the inguinal ligament compared with the other planes. In contrast, the coronal views were very useful in the evaluation of femoral hernias. Conclusions: The high-resolution coronal and sagittal images available from multisection CT now permit the accurate diagnosis of groin hernias. Using simple anatomical criteria, direct and indirect inguinal hernias and femoral hernias can be reliably distinguished, abolishing the need for surrogate markers, which was hitherto necessary.

  20. Contrast investigation of multi-slice spiral CT perfusion imaging and pathological findings in VX2 soft-tissue tumor of rabbits

    Institute of Scientific and Technical Information of China (English)

    Jingfeng Zhang; Renfa Wang; Min Wang; Jing Zhang; Jinmei Sang

    2005-01-01

    Objective: To perform a contrast investigation of multi-slice spiral CT (MSCT) perfusion imaging and pathological findings in VX2 soft-tissue tumor of rabbits, and discuss the applicative value of multi-slice spiral CT perfusion imaging in soft-tissue tumors. Methods: 8 Newzealand white rabbits were implanted with 0.1 ml VX2 tumor tissue suspension in bilateral proximal thighs. 14 days and 21 days later, CT plain scan and perfusion scan were performed on these rabbits respectively, then the images were transmitted to AW4.0 workstation, the functional maps and perfusion parameters including blood flow (BF), blood volume (BV), mean transit time(MTT) and permeability surface (PS) were computed and analyzed. Subsequently, the rabbits were sacrificed, the tumors of which were taken out for pathological examination. The correlation between MSCT functional parametric images and pathological findings was analyzed.Results: All the values of BF, BV and PS of VX2 soft-tissue tumors were obviously higher while the MTT-values were lower than those of the normal muscular tissues significantly ( P < 0.001). Conclusion: Multi-slice spiral CT perfusion imaging is an accurate, convenient and relatively safe functional imaging technique, which can give a quantitative assessment to blood perfusion and angiogenesis of soft-tissue tumors.

  1. Use of spiral CT and the contrast medium iohexol to determine in one session aortorenal morphology and the relative glomerular filtration rate of each kidney

    Energy Technology Data Exchange (ETDEWEB)

    Frennby, B.; Almen, T. [Malmoe Allmaenna Sjukhus (Sweden). Dept. of Radiology

    2001-11-01

    The aim of this study was to determine the relative glomerular filtration rate (GFR), i.e. the GFR of each kidney in percent of total GFR, by spiral CT. In 41 patients, who were part of a follow-up program after endoluminal stent grafting of aortic aneurysm, spiral CT with the contrast medium iohexol was used to evaluate the morphology of the aorta and kidneys. The opportunity was taken to utilize the already injected iohexol to determine the relative GFR with an extra CT sequence. In each patient two determinations were made, 6 or 12 months apart. The amount of a GFR marker accumulating in Bowman's space, tubuli, and renal pelvis within 2-3 min after i.v. injection, before any marker had left the kidney via the ureter, was defined as proportional to the GFR of that kidney. The renal accumulation of iohexol was obtained by spiral CT using 10-mm collimation and a table speed of 10 mm/s (pitch ratio 1:1) from the upper to the lower poles. The correlation coefficient between the relative GFR of each kidney determined at the first and second examination was excellent (r=0.99) with a median (range) difference of 1% (0-6%) of total GFR. The radiation dose calculated as the mean absorbed dose to the kidneys was 50 mGy and the effective dose 5 mSv. The morphology of aorta and kidneys and the relative GFR of each kidney can be determined in one session with spiral CT using iohexol as both angiographic contrast medium and as a GFR marker. It is also possible to take some plasma samples in the same session to determine iohexol concentration to calculate the body clearance of iohexol (or take plasma and urine samples to calculate the renal clearance of iohexol). (orig.)

  2. Dynamic changes in hair cell ribbon synapse induced by loss of spiral ganglion neurons in mice

    Institute of Scientific and Technical Information of China (English)

    Yuan Yasheng; Chi Fanglu

    2014-01-01

    Background Previous studies have suggested that primary degeneration of hair cells causes secondary degeneration of spiral ganglion neurons (SGNs),but the effect of SGN degeneration on hair cells has not been studied.In the adult mouse inner ear ouabain can selectively and permanently induce the degeneration of type 1 SGNs while leaving type 2 SGNs,efferent fibers,and sensory hair cells relatively intact.This study aimed to investigate the dynamic changes in hair cell ribbon synapse induced by loss of SGNs using ouabain application to the round window niche of adult mice.Methods In the analysis,24 CBA/CAJ mice aged 8-10 weeks,were used,of which 6 normal mice were used as the control group.After ouabain application in the round window niche 6 times in an hour,ABR threshold shifts at least 30 dB in the three experimental groups which had six mice for 1-week group,six for 1-month group,and six for 3-month group.All 24 animals underwent function test at 1 week and then immunostaining at 1 week,1 month,and 3 months.Results The loss of neurons was followed by degeneration of postsynaptic specializations at the afferent synapse with hair cells.One week after ouabain treatment,the nerve endings of type 1 SGNs and postsynaptic densities,as measured by Na/K ATPase and PSD-95,were affected but not entirely missing,but their partial loss had consequences for synaptic ribbons that form the presynaptic specialization at the synapse between hair cells and primary afferent neurons.Ribbon numbers in inner hair cells decreased (some of them broken and the ribbon number much decreased),and the arrangement of the synaptic ribbons had undergone a dynamic reorganization:ribbons with or without associated postsynaptic densities moved from their normal location in the basal membrane of the cell to a more apical location and the neural endings alone were also found at more apical locations without associated ribbons.After 1 month,when the neural postsynaptic densities had completed their

  3. Slow [Na+]i dynamics impacts arrhythmogenesis and spiral wave reentry in cardiac myocyte ionic model

    Science.gov (United States)

    Krogh-Madsen, Trine; Christini, David J.

    2017-09-01

    Accumulation of intracellular Na+ is gaining recognition as an important regulator of cardiac myocyte electrophysiology. The intracellular Na+ concentration can be an important determinant of the cardiac action potential duration, can modulate the tissue-level conduction of excitation waves, and can alter vulnerability to arrhythmias. Mathematical models of cardiac electrophysiology often incorporate a dynamic intracellular Na+ concentration, which changes much more slowly than the remaining variables. We investigated the dependence of several arrhythmogenesis-related factors on [Na+]i in a mathematical model of the human atrial action potential. In cell simulations, we found that [Na+]i accumulation stabilizes the action potential duration to variations in several conductances and that the slow dynamics of [Na+]i impacts bifurcations to pro-arrhythmic afterdepolarizations, causing intermittency between different rhythms. In long-lasting tissue simulations of spiral wave reentry, [Na+]i becomes spatially heterogeneous with a decreased area around the spiral wave rotation center. This heterogeneous region forms a functional anchor, resulting in diminished meandering of the spiral wave. Our findings suggest that slow, physiological, rate-dependent variations in [Na+]i may play complex roles in cellular and tissue-level cardiac dynamics.

  4. Pulmonary emphysema quantitation with Computed Tomography. Comparison between the visual score with high resolution CT, expiratory density mask with spiral CT and lung function studies; Valutazione quantitativa dell`enfisema polmonare mediante Tomografia Computerizzata. Confronto tra il punteggio visivo con alta risoluzione nell`inspirazione, maschera della densita` automatica con Tomografia Computerizzata spirale nell`espirazione ed esami funzionali respiratori

    Energy Technology Data Exchange (ETDEWEB)

    Zompatori, Maurizio; Battaglia, Milva; Rimondi, Maria Rita; Vivacqua, Donatella; Biscarini, Manuela [Policlinico S. Orsola-Malpighi, Bologna (Italy). Radiologia padiglione Pneumonefro; Fasano, Luca; Pacilli, Angela Maria Grazia; Guerrieri, Aldo; Fabbri, Mario [Policlinico S. Orsola-Malpighi, Bologna (Italy). Istituto di Fisiopatologia Respiratoria; Cavina, Mauro [Policlinico S. Orsola-Malpighi, Bologna (Italy). TSRM. Servizio di Tomografia Computerizzata

    1997-04-01

    CT is the most accurate method to detect pulmonary emphysema in vivo. They compared prospectively two different methods for emphysema quantitation in 5 normal volunteers and 20 consecutive patients with chronic obstructive pulmonary disease (COPD). All subjects were submitted to function tests and HRCT; three scans were acquired at preselected levels during inspiration. The type and extent of pulmonary emphysema were defined by two independent observers under blind conditions. Disagreements were subsequently settled by consent. All subjects were also examined with expiratory spiral CT using a density mask program, at two different cut-off levels (-850,-900 HU). Visual score and expiratory spiral density mask values (-850 HU) were significantly correlated (r = 0.86), but the visual extent of emphysema was always higher than shown by expiratory spiral CT. The emphysema extent assessed with both CT methods correlated with the function result of expiratory airflow obstruction and gas diffusion impairment (visual score versus forced expiratory volume in one second: r = -0.81, versus single breath carbon monoxide diffusion: r = -0.78. Spiral expiratory density mask -850 HU versus forced expiratory volume in one second: r = -0.85 versus single breath carbon monoxide diffusion: r = -0.77). When -900 HU was used as the cut-off value for the expiratory density mask, the correlation with single breath carbon monoxide diffusion worsened (r = -0.56). Visual score and expiratory density mask -850 HU gave similar results and permitted COPD patients to be clearly distinguished from normal controls (p < 0.01). They believe the true residual volume should lie somewhere in between the CT value and the function results with the helium dilution technique and conclude that the extent of pulmonary emphysema can be confidently assessed with CT methods. Finally, the simple visual score may be as reliable as such highly sophisticated new methods as the spiral expiratory density mask

  5. Clinical application of multi-slice spiral CT urography in traumatic urine leaka%外伤性尿漏多层螺旋CT诊断

    Institute of Scientific and Technical Information of China (English)

    俞国有

    2012-01-01

    Objective To explore the diagnostic value of multi-slice CT in the urine leakage. Methods 20 cases of urine leaks confirmed by clinical diagnosis underwent spiral CT plain scanning and triphasic dynamic enhancement scanning. The CT features on axial images and multiplanar reformation (MPR). maximum intensity projection (MIP) and volume rendering (VR) were reviewed. Results The breakage in renal parenchyma, subcapsular hematoma of kidney, prerenal fascia thickening appeared in 15 cases with pelvis leak affected by trauma. The excretory phase could detect 2 cases wfth ureteral leakage. 3 cases with bladder leak had the defect of posterior wall. Encapsulated effusion in rectal bladder space and eggshell-like calcification of the wall could be found, the contrast agent inpoured the urinary vesicle through the defect of the bladder wall. Conclusion Since the multi-slice CT urography (MSCT) examination clearly shows the leakage, the site of urine leakage. the scope of urinary vesicle. and other complications. it can be used as a preferred diagnostic method of urinary leakage.%目的 探讨多层螺旋CT对肾盂、输尿管及膀胱外伤性尿漏的诊断价值.方法 搜集20例经临床证实发生尿漏患者多层螺旋CT检查.全部行增强三期扫描.运用多种CT后处理技术(MPR、VR、MIP)综合分析其MSCT特点.结果 20例患者中,肾盂尿漏15例,输尿管尿漏2例,膀胱尿漏3例,排泄期表现为对比剂外渗,各种后处理技术可以清晰显示漏口的部位及范围,并可合并显示肝脾破裂、肾实质破裂、肾包膜下血肿、肾周间隙积液、骨盆多发骨折等.结论 MSCT延迟增强扫描能清晰显示尿漏的部位、漏口和并发症,对尿漏的诊断和选择治疗方案提供重要依据,可以作为尿漏诊断首选方法.

  6. Accuracy and reliability of thyroid volumetry using spiral CT and thyroid volume in a healthy, non-iodine-deficient Chinese adult population

    Energy Technology Data Exchange (ETDEWEB)

    Shu Jian, E-mail: shujiannc@163.com [Department of Radiology, Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010 (China); Zhao Jiannong, E-mail: zhaojiannong@tom.com [Department of Radiology, Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010 (China); Guo Dajing, E-mail: guodaj@163.com [Department of Radiology, Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010 (China); Luo Yindeng, E-mail: yindengluo_1019@163.com [Department of Radiology, Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010 (China); Zhong Weijia, E-mail: zhongweijia2003@eyou.com [Department of Radiology, Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010 (China); Xie Weibo, E-mail: radiologycq@163.com [Department of Radiology, Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010 (China)

    2011-02-15

    Objective: The purpose of this study was to assess the accuracy and reliability of thyroid volumetry using spiral CT and to investigate thyroid volumes for a healthy, non-iodine-deficient adult population in southwestern region of China. Materials and methods: Spiral CT was performed in phantoms and adult subjects with normal thyroid, and the volumes were measured by observers with 5 years or more of CT experience. The phantom volumes and the thyroid volumes of all subjects were noted. Results: For the thyroid phantoms, there was no significant difference between the true and CT calculated volumes (t = 0.862, P = 0.399), and the correlation was excellent (ICC = 0.9995, P = 0.000). In the subjects for reliability analysis, the intraobserver or interobserver differences for CT volumetric measurement of thyroid were not significant (P > 0.05). The intraobserver or interobserver correlations were very high (ICC > 0.99, P < 0.001). In the subjects for population analysis, the median of the thyroid volumes was 11.45 cm{sup 3}. The nonparametric Mann-Whitney U-test showed no significant difference for the thyroid volume between sexes (U = 4388.00, Z = -1.118, P = 0.264). The nonparametric Kruskall-Wallis test showed no significant difference in all age groups ({chi}{sup 2} = 13.466, P = 0.062). There was a slight negative correlation between the thyroid volume and age (r{sub s} = -0.166, P = 0.019). Conclusion: The accuracy and reliability of multi-slice spiral CT in measuring thyroid volume are very high. The thyroid volumes are not significantly difference between genders or among decades for the healthy, non-iodine-deficient adult population in southwestern region of China.

  7. 3D spiral CT imaging of bone anomalies in a case of diastematomyelia

    Energy Technology Data Exchange (ETDEWEB)

    Skalej, Martin [Department of Neuroradiology, University of Tuebingen, Hoppe-Seyler Str. 3, 72076 Tuebingen (Germany); Duffner, Frank [Department of Neurosurgery, University of Tuebingen, Tuebingen (Germany); Stefanou, Alexander [Department of Neuroradiology, University of Tuebingen, Hoppe-Seyler Str. 3, 72076 Tuebingen (Germany); Petersen, Dirk [Department of Neuroradiology, University of Tuebingen, Hoppe-Seyler Str. 3, 72076 Tuebingen (Germany)

    1999-03-01

    The case of a 48-year-old woman, suffering from a diastematomyelia, is presented. This case and the diagnostic findings are used to demonstrate the demands on imaging methods with respect to a new classification of split cord malformations (SCMs) recently published. Although MRI is the method of choice for imaging of the spinal cord generally, only X-ray methods and especially conventional computer tomography provide the information necessary for correct classification of SCMs. Additional 3D-reconstructions from suitable CT-data are helpful in visualizing complex anomalies of bony structures found in most cases of SCM.

  8. Multi-detector spiral CT study of the relationships between pulmonary ground-glass nodules and blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Feng; Li, Ming; Ge, Xiaojun; Ren, Qingguo; Hua, Yanqing [Huadong Hospital Fudan University, Department of Radiology, Shanghai (China); Zheng, Xiangpeng [Huadong Hospital Fudan University, Department of Radiation Oncology, Shanghai (China); Chen, Yan [Huadong Hospital Fudan University, Department of Pathology, Shanghai (China); Lv, Fangzhen [Huadong Hospital Fudan University, Department of Thoracic Surgery, Shanghai (China)

    2013-12-15

    To investigate the relationships between pulmonary ground-glass nodules (GGN) and blood vessels and their diagnostic values in differentiating GGNs. Multi-detector spiral CT imaging of 108 GGNs was retrospectively reviewed. The spatial relationships between GGNs and supplying blood vessels were categorized into four types: I, vessels passing by GGNs; II, intact vessels passing through GGNs; III, distorted, dilated or tortuous vessels seen within GGNs; IV, more complicated vasculature other than described above. Relationship types were correlated to pathologic and/or clinical findings of GGNs. Of 108 GGNs, 10 were benign, 24 preinvasive nodules and 74 adenocarcinomas that were pathologically proven. Types I, II, III and IV vascular relationships were observed in 9, 58, 21 and 20 GGNs, respectively. Type II relationship was the dominating relationship for each GGN group, but significant differences were shown among them. Correlation analysis showed strong correlation between invasive adenocarcinoma and type III and IV relationships. Subgroup analysis indicated that type III was more commonly seen in IAC with comparison to type IV more likely seen in MIA. Different GGNs have different relationships with vessels. Understanding and recognising characteristic GGN-vessel relationships may help identify which GGNs are more likely to be malignant. (orig.)

  9. Cartilage lesions of the glenohumeral joint: diagnostic effectiveness of multidetector spiral CT arthrography and comparison with arthroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lecouvet, Frederic E.; Dorzee, Benjamin; Berg, Bruno C. vande; Malghem, Jacques [Cliniques Universitaires St Luc, Universite Catholique de Louvain, Department of Radiology, Brussels (Belgium); Dubuc, Jean E. [Cliniques Universitaires St Luc, Universite Catholique de Louvain, Department of Orthopaedic Surgery, Brussels (Belgium); Jamart, Jacques [Mont Godinne University Hospital, Center of Biostatistics, Yvoir (Belgium)

    2007-07-15

    This study assessed the diagnostic effectiveness of multidetector spiral CT arthrography (MDCTa) in detecting hyaline cartilage abnormalities of the shoulder joint, with correlation to arthroscopy. Shoulder MDCTa images prospectively obtained in 22 consecutive patients (mean age, 50 years; age range, 23-74 years; 12 female, 10 male) were evaluated for glenohumeral cartilage lesions. Two musculoskeletal radiologists independently analysed the cartilage surfaces of the humeral head and of the glenoid fossa in nine anatomical surface areas. Observations of MDCTa were compared to arthroscopic findings. The sensitivity and specificity of MDCTa for grade 2 (substance loss <50%) or higher and grade 3 (substance loss {>=}50%) or higher cartilage lesions, the Spearman correlation coefficient between arthrographic and arthroscopic grading, and K statistics for assessing Intra and Interobserver reproducibility were determined. At MDCTa, sensitivities and specificities ranged between 80% and 94% for the detection of grade 2 or higher cartilage lesions, and between 88% and 98% for the detection of grade 3 or higher cartilage lesions. Spearman correlation coefficients between MDCTa and arthroscopic grading of articular surfaces ranged between 0.532 and 0.651. Interobserver agreement was moderate for grading all articular surfaces ({kappa} = 0.457), but substantial to almost perfect for detecting lesions with substance loss ({kappa}, 0.618-0.876). In conclusion, MDCTa is accurate for the study of cartilage surface in the entire shoulder joint. This technique may beneficially impact patient's management by means of selecting the proper treatment approach. (orig.)

  10. Dynamics and morphology of the Milky Way spiral arms from the metallicity distribution and radial mixing

    Science.gov (United States)

    Martinez-Medina, L. A.; Pichardo, B.; Peimbert, A.; Carigi, L.

    2017-07-01

    Albeit radial migration must be a ubiquitous process in disc galaxies, its significance in the evolution of stellar discs is not always reflected through global trends. However, there are other key observables, such as the metallicity distribution function (MDF), that may shed some light in this matter. We argue that the shape of the MDF not only tells us whether the stellar disc experienced radial migration but it also contains important clues on the structure that triggered it. Specifically, the MDF contains information about the dynamics and morphology of the spiral pattern. To constrain the spiral parameters, we have included a detailed chemical tagging in our simulations; this allows us to produce a restriction of the structural parameters of the spiral arms in the Milky Way as well as a method to constrain chemical evolution models towards the centre of the Galactic disc, where no chemical model provides information. We also found that it is unlikely that the Sun was formed near its current galactocentric position; therefore, it might be inaccurate to consider the Sun as representative of the chemical abundances in the solar neighbourhood. We also show that a stellar disc of the Milky Way, after evolving dynamically and chemically for 5 Gyr, preserves 80 per cent of its original global metallicity gradient despite having suffered important heating and radial migration; this means that the presence of a metallicity gradient in a given galaxy does not guarantee that radial mixing has not played a role in its evolution.

  11. Spiral-wave dynamics in excitable medium with excitability modulated by rectangle wave

    Institute of Scientific and Technical Information of China (English)

    Yuan Guo-Yong

    2011-01-01

    We numerically study the dynamics of spiral waves in the excitable system with the excitability modulated by a rectangle wave. The tip trajectories and their variations with the modulation period T are explained by the corresponding spectrum analysis. For a large T, the external modulation leads to the occurrence of more frequency peaks and these frequencies change with the modulation period according to their specific rules, respectively. Some of the frequencies and a primary frequency f1 determine the corresponding curvature periods, which are locked into rational multiplies of the modulation period. These frequency-locking behaviours and the limited life-span of the frequencies in their variations with the modulation period constitute many resonant entrainment bands in the T axis. In the main bands, which follow the relation T/T12=m/n,the size variable Rx of the tip trajectory is a monotonic increasing function of T. The rest of the frequencies are linear combinations of the two ones. Due to the complex dynamics, many unique tip trajectories appear at some certain T. We find also that spiral waves are eliminated when T is chosen from the end of the main resonant bands. This offers a useful method of controling the spiral wave.

  12. Dynamics of a spiral pair source and its interaction with plane waves.

    Science.gov (United States)

    Rabinovitch, A; Biton, Y; Gutman, M; Aviram, I

    2009-05-01

    Spiral pair creation and dynamics is a widely occurring phenomenon in nature. It can appear in the heart tissue, causing severe arrhythmia, known as a figure-eight reentry. We consider the appearance of a spiral pair source, its minimal strength for survival, and the possible results of its interaction with a plane wave. In particular, its ability to outlast such an encounter is of interest. We also consider the question of exposing the source to a train of pulses, in terms of the frequency and angle of encounter. Results show different regimes of behavior, e.g. source annihilation, motion of the source away from, or towards the origin of the plane waves, its breaking and multiplication. Relevance of these results to heart arrhythmia and their possible cancellation by external pacing are briefly discussed.

  13. Personal computer aided cerebral perfusion imaging with dynamic CT

    Institute of Scientific and Technical Information of China (English)

    林燕; 高培毅

    2004-01-01

    @@Reports on the clinical implementation of dynamic computerised tomography (CT) perfusion imaging and quantitative measurement have increased dramatically of late.1-8 The advantages of dynamic CT perfusion imaging and quantitative measurement for the diagnosis of acute cerebral infarction have been acknowledged. However, most overseas CT vendors set perfusion imaging software package as an option for graphic workstation at a too high price for domestic practitioners. To foster the domestic implementation and development of this new technology, we have extended the earlier work.1,2 Applying the theory of central volume principle to DICOM 3.0 standard forms of prime CT images, we developed dynamic CT perfusion imaging and quantitative measure-ment programmes for PCs using Visual C+ + in Windows 98 system.

  14. The value of spiral CT in diagnosis of small bowel Crohn disease%小肠Crohn病的螺旋CT诊断价值

    Institute of Scientific and Technical Information of China (English)

    王祖飞; 纪建松; 周利民; 苏金亮; 徐民

    2011-01-01

    目的:探讨螺旋CT对小肠Crohn病的诊断价值.方法:回顾性分析10例经病理证实的小肠Crohn病螺旋CT表现,将螺旋CT表现与小肠造影进行比较,分析其影像学特点.结果:10例患者中小肠造影发现6例异常,表现为肠腔节段性狭窄、肠粘膜破坏及瘘管形成.10例CT表现为多节段肠壁及肠系膜增厚,肠壁不同程度强化,3例出现肠瘘,2例出现腹腔脓肿及肠梗阻,肠系膜淋巴结肿大3例.结论:螺旋CT对小肠Crohn病的部位及性质诊断较小肠造影更具有优势,同时能更多观察肠内外病变,并能判断临床治疗效果,有可能成为小肠Crohn病的主要影像学诊断方法.%Objective:To investigate the value of spiral CT in the diagnosis of small-bowel Crohn disease. Methods:Spiral CT manifestation of 10 patients with small-bowel Crohn disease pathologically proved were analysed retrospectively, and compared with the small bowel radiography, the imaging feature of spiral CT in smali-bowel Crohn disease were analysed.Resujts: Of the 10 patients, there were abnormal manifestations in 6 patients on small bowel radiography, they were segmental luminal narrowing, mucosal destroy and fistula forming. On spiral CT, mural and mesenteric thickening and mucosal hyperenhancement in 10 patients, fistula in 3 patients, abdominal cavity abscess and small bowel obstruction in 2 patients, bowel mesenteric lymphadenectasis in 3 patients. Conclusion:Spiral CT can provide an advantage of not only showing the location and character of small bowel Crohn disease compared with small bowel radiography, but also changes out of and in the luminal of small bowel, the clinical therapeutic effect, and may be a main imaging method in diagnosis of small bowel Crohn disease.

  15. An evaluation of the feasibility of assessment of volume perfusion for the whole lung by 128-slice spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Haitao [Imaging Center of Taian Central Hospital, Taian, Shandong (China); Gao, Fei; Li, Ning; Liu, Cheng [Shandong Univ., Shandong Medical Imaging Research Inst., CT Room, Shandong (China)], e-mail: liucheng491025@sina.com

    2013-10-15

    Background: Lung perfusion based on dynamic scanning cannot provide a quantitative assessment of the whole lung because of the limited coverage of the current computed tomography (CT) detector designs. Purpose: To evaluate the feasibility of dynamic volume perfusion CT (VPCT) of the whole lung using a 128-slice CT for the quantitative assessment and visualization of pulmonary perfusion. Material and Methods: Imaging was performed in a control group of 17 subjects who had no signs of disturbance of pulmonary function or diffuse lung disease, and 15 patients (five patients with acute pulmonary embolism and 10 with emphysema) who constituted the abnormal lung group. Dynamic VPCT was performed in all subjects, and pulmonary blood flow (PBF), pulmonary blood volume (PBV), and mean transit time (MTT) were calculated from dynamic contrast images with a coverage of 20.7 cm. Regional and volumetric PBF, PBV, and MTT were statistically evaluated and comparisons were made between the normal and abnormal lung groups. Results: Regional PBF (94.2{+-}36.5, 161.8 {+-}29.6, 185.7 {+-}38.1 and 125.5 {+-}46.1, 161.9 {+-}31.4, 169.3 {+-}51.7), PBV (6.7 {+-}2.8, 10.9 {+-}3.0, 12.9 {+-}4.5 and 9.9 {+-}4.6, 10.3 {+-}2.9, 11.9 {+-}4.5), and MTT (5.8 {+-}2.4, 4.5 {+-}1.3, 4.7 {+-}2.1 and 5.6 {+-}2.3, 4.3 {+-}1.5, 4.9 {+-}1.5) demonstrated significant differences in the gravitational and isogravitational directions in the normal lung group (P < 0.05). The PBF (154.2 {+-}30.6 vs. 94.9 {+-}15.9) and PBV (11.1 {+-}4.0 vs. 6.6 {+-}1.7) by dynamic VPCT showed significant differences between normal and abnormal lungs (P < 0.05), notwithstanding the four large lungs that had coverage > 20.7 cm. Conclusion: Dynamic VPCT of the whole lung is feasible for the quantitative assessment of pulmonary perfusion by 128-slice CT, and may in future permit the evaluation of both morphological and functional features of the whole lung in a single examination.

  16. Turbulent Flow Characteristics and Dynamics Response of a Vertical-Axis Spiral Rotor

    Directory of Open Access Journals (Sweden)

    Yuli Wang

    2013-05-01

    Full Text Available The concept of a vertical-axis spiral wind rotor is proposed and implemented in the interest of adapting it to air flows from all directions and improving the rotor’s performance. A comparative study is performed between the proposed rotor and conventional Savonius rotor. Turbulent flow features near the rotor blades are simulated with Spalart-Allmaras turbulence model. The torque coefficient of the proposed rotor is satisfactory in terms of its magnitude and variation through the rotational cycle. Along the height of the rotor, distinct spatial turbulent flow patterns vary with the upstream air velocity. Subsequent experiments involving a disk generator gives an in-depth understanding of the dynamic response of the proposed rotor under different operation conditions. The optimal tip-speed ratio of the spiral rotor is 0.4–0.5, as is shown in both simulation and experiment. Under normal and relative-motion flow conditions, and within the range of upstream air velocity from 1 to 12 m/s, the output voltage of the generator was monitored and statistically analyzed. It was found that normal air velocity fluctuations lead to a non-synchronous correspondence between upstream air velocity and output voltage. In contrast, the spiral rotor’s performance when operating from the back of a moving truck was significantly different to its performance under the natural conditions.

  17. Solitary pulmonary granuloma with marked enhancement on dynamic CT scanning

    Energy Technology Data Exchange (ETDEWEB)

    Stark, P.; Wong, V.; Gold, P.

    1988-10-01

    A patient is described who presented with a vividly enhancing solitary pulmonary nodule during dynamic CT scanning. This mass proved to represent a granuloma due to coccidioidomycosis. The presumptive mechanism of enhancement as well as the differential diagnosis are discussed.

  18. Diagnostic value of multi-slice spiral CT in sternum fracture%多层螺旋CT对胸骨骨折诊断价值

    Institute of Scientific and Technical Information of China (English)

    黎健樟; 郭冬梅

    2014-01-01

    Objective:To explore the clinical value of multi-slice spiral CT expedition in the diagnosis of sternum fracture. Methods:28 cases with sternum fracture were selected from 2011 to 2013.They were as the research objects.At the same time,the multi-slice spiral CT diagnosis data were comprehensively reviewed and analyzed.Results:28 cases in this group were confirmed by multi-slice spiral CT and multiplanar reconstruction (MPR).The diagnose accordance rate was 100%.18 cases(64.29%) were diagnosed manubrium fracture.10 cases(35.71% ) were diagnosed mesosternum fracture.5 cases(17.86% ) were combined with substernal mediastinal emphesema.12 cases(42.86%) were combined with substernal mediastinal hematoma by CT scan and MPR reestablishment.Conclusion:The multi-slice spiral CT in the diagnosis of sternum fracture has ideal and reliable diagnosis effect.It is the key for clinical diagnosis of the disease as early as possible and formulating targeted treatment schedule in the future.It suggests strengthen the popularization in clinical.%目的:探讨在胸骨骨折的诊断中应用多层螺旋CT探查的临床价值。方法:2011-2013年收治胸骨骨折患者28例,作为本次研究对象,同时与其多层螺旋CT诊断资料相结合,进行综合性回顾与分析。结果:本组28例病例均经多层螺旋 CT 检查或多平面重建(MPR)后确诊,诊断符合率100%。包括18例(64.29%)诊断为胸骨柄骨折,10例(35.71%)诊断为胸骨体骨折。其中5例(17.86%)合并胸骨后纵隔气肿,12例(42.86%)经CT扫描、MPR重建后提示合并胸骨后纵隔血肿。结论:为胸部骨折患者提供多层螺旋CT诊断,能够起到理想、可靠的诊断效果,是今后临床尽早诊断本病并制定有针对性治疗方案的关键,建议临床加强普及。

  19. Pattern formation of coupled spiral waves in bilayer systems: rich dynamics and high-frequency dominance.

    Science.gov (United States)

    Nie, Haichun; Gao, Jihua; Zhan, Meng

    2011-11-01

    The interaction of two spiral waves with independent frequencies in a bilayer oscillatory medium (one spiral in each layer) and with a symmetric coupling e is studied. If the spirals have different frequencies, the faster spiral is unaffected by the slower one, and the slower can show a variety of behaviors, which depend on e and include, in order of increasing e, phase drifting, amplitude modulation, amplitude domination, and phase synchronization. This high-frequency dominance, the asymmetric driving-response effect under the condition of a symmetric coupling, is generic and independent of whether the coupled spiral waves are outwardly rotating or inwardly rotating spirals. If the spirals have identical frequencies, they may even show complete synchronization, parallel drift, or circular drift, depending on the relative rotation direction of the two spirals and their initial separation distance. Comparisons with coupled spirals in monolayer media, previous works on coupled spirals in bilayer systems, and coupled phase oscillators are made.

  20. Multislice helical CT (MSCT) for mid-facial trauma: optimization of parameters for scanning and reconstruction; Mehrschicht-Spiral-CT (MSCT) beim Mittelgesichtstrauma: Optimierung der Aufnahme- und Rekonstruktionsparameter

    Energy Technology Data Exchange (ETDEWEB)

    Dammert, S.; Funke, M.; Obernauer, S.; Grabbe, E. [Abt. Roentgendiagnostik I, Georg-August-Univ. Goettingen (Germany); Merten, H.A. [Abt. fuer Mund-, Kiefer- und Gesichtschirurgie, Georg-August-Univ. Goettingen (Germany)

    2002-07-01

    Purpose: To determine the optimal scan parameters in multislice helical CT (MSCT) of the facial bone complex for both axial scanning and multiplanar reconstructions. Material and Methods: An anthropomorphic skull phantom was examined with a MSCT. Axial scans were performed with continuously increasing collimations (4 x 1.25 - 4 x 2.5 mm), tube current (20 - 200 mA) and table speeds (3.75 mm/rot. and 7.5 mm/rot.). Multiplanar reconstructions in coronal and parasagittal planes with different reconstruction increment and slice thickness were evaluated in terms of image noise, contour artifacts and visualisation of anatomical structures. Results: The best image quality was obtained with a collimation of 4 x 1.25 mm and a - table speed of 3.75 mm/rot. A reconstruction increment of 0.6 mm achieved the best time to image quality relation. With these parameters the bone structures were depicted in an optimal way without artifacts. The tube current could be reduced to 50 mA without significant loss of image quality. The optimized protocol was used for regular routine examinations in patients with facial trauma (n = 66). Conclusions: Low-dose MSCT using thin collimation, low table speed and small reconstruction increments provides excellent data for both axial images and multiplanar reconstructions in patients with facial trauma. An additional examination in coronal orientation is therefore no longer necessary. (orig.) [German] Zielsetzung: Verbesserung der Aufnahme- und Rekonstruktionsparameter in der Mehrschicht Spiral-CT (MSCT) zur Untersuchung des knoechernen Mittelgesichtes in verschiedenen Ebenen. Material und Methode: Ein anthropomorphes Schaedel-Phantom wurde in axialer Schichtfuehrung mit einem MSCT untersucht, wobei die Kollimation (1,25 - 2,5 mm), der Tischvorschubfaktor (Pitch 3 - 6) und der Roehrenstrom (20 - 200 mA) systematisch variiert wurden. Aus den Volumendatensaetzen wurden jeweils koronare und parasagittale Sekundaerreformationen mit unterschiedlichen

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

    Institute of Scientific and Technical Information of China (English)

    BAI Rong-jie; WANG Jin-e; JIANG Hui-jie; HAO Xue-jia; DONG Xu-peng; HUANG Ya-hua; WEI Lai

    2013-01-01

    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 mi/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 mi/s 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 (HAI),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.

  2. Spiral CT in diagnosis of acute pancreatitis%螺旋CT对急性胰腺炎的诊断价值

    Institute of Scientific and Technical Information of China (English)

    刘辉

    2012-01-01

    Objective To explore the diagnostic value of spiral CT in acute pancreatitis. Methods 59 cases of patients suspected acute pancreatitis underwent spiral CT scanning with the thickness of 5mm layer from 5mmt intravenous injection of iohexol in the first plain line enhanced scan, the key observation pancreas size, shape, peripancreatic kidney next to the fascia,the gap,chest and abdominal cavity. Results 59 cases of pancreatitis were all accurate diagnosis and the accuracy of spiral CT was 100% (59/59), 42 cases of acute edematous pancreatitis, acute necrotizing pancreatitis in 17 cases, 5 cases of co-infection. CT signs appear that the rate of high and low as follows: pancreatic volume increases, the thickening of the perirenal fascia edema, pancreatic fluid, pancreatic necrosis. Conclusion Spiral CT diagnosis of acute pancreatitis is simple, effective way, especially the enhanced scan to identify acute pancreatitis lesion types with high sensitivity.%目的 探讨螺旋CT对急性胰腺炎的临床诊断价值.方法 对临床疑诊急性胰腺炎的59例患者行螺旋CT扫查,取层厚5mm,层距5mm;先行平扫后静脉注射碘海醇行增强扫描,重点观察胰腺大小、形态、胰周肾旁筋膜、间隙、胸腹腔情况.结果 59例急性胰腺炎患者经螺旋CT全部准确诊断,准确率100%(59/59).在59例病人中急性水肿型胰腺炎42例,急性坏死型胰腺炎17例;有5例合并感染.CT征象出现率高低依次为:胰腺体积增大、肾周筋膜水肿增厚、胰外积液、胰腺坏死.结论 螺旋CT是诊断急性胰腺炎的简便、有效的方法,特别是增强扫描对鉴别急性胰腺炎的病变类型具有很高的敏感性.

  3. Spiral-Wave Dynamics in Ionically Realistic MathematicalModels for Human Ventricular Tissue: The Effects of PeriodicDeformation

    Directory of Open Access Journals (Sweden)

    Alok Ranjan Nayak

    2014-06-01

    Full Text Available We carry out an extensive numerical study of the dynamics of spiral waves of electrical activation, in the presence of periodic deformation (PD in two-dimensional simulation domains, in the biophysically realistic mathematical models of human ventricular tissue due to (a ten-Tusscher and Panfilov (the TP06 model and (b ten-Tusscher, Noble, Noble, and Panfilov (theTNNP04 model. We first consider simulations in cable-type domains, in which we calculate the conduction velocity $CV$ andthe wavelength $lambda$ of a plane wave; we show that PD leads to a periodic, spatial modulation of $CV$ and a temporallyperiodic modulation of $lambda$; both these modulations depend on the amplitude and frequency of the PD. We then examine three types of initial conditions for both TP06 and TNNP04 models and show that the imposition of PD leads to a rich variety ofspatiotemporal patterns in the transmembrane potential including states with a single rotating spiral (RS wave, a spiral-turbulence (ST state with a single meandering spiral, an ST state with multiple broken spirals, and a state SA in which all spirals are absorbed at the boundaries of our simulation domain. We find, for both TP06 and TNNP04 models, that spiral-wave dynamics depends sensitively on the amplitude and frequency of PD and the initial condition. We examine how these different types of spiral-wave states can be eliminated in the presence of PD by the application of low-amplitude pulses on square and rectangular control meshes. We suggest specific experiments that can test the results of our simulations.

  4. Spiral-wave dynamics in ionically realistic mathematical models for human ventricular tissue: the effects of periodic deformation.

    Science.gov (United States)

    Nayak, Alok R; Pandit, Rahul

    2014-01-01

    We carry out an extensive numerical study of the dynamics of spiral waves of electrical activation, in the presence of periodic deformation (PD) in two-dimensional simulation domains, in the biophysically realistic mathematical models of human ventricular tissue due to (a) ten-Tusscher and Panfilov (the TP06 model) and (b) ten-Tusscher, Noble, Noble, and Panfilov (the TNNP04 model). We first consider simulations in cable-type domains, in which we calculate the conduction velocity θ and the wavelength λ of a plane wave; we show that PD leads to a periodic, spatial modulation of θ and a temporally periodic modulation of λ; both these modulations depend on the amplitude and frequency of the PD. We then examine three types of initial conditions for both TP06 and TNNP04 models and show that the imposition of PD leads to a rich variety of spatiotemporal patterns in the transmembrane potential including states with a single rotating spiral (RS) wave, a spiral-turbulence (ST) state with a single meandering spiral, an ST state with multiple broken spirals, and a state SA in which all spirals are absorbed at the boundaries of our simulation domain. We find, for both TP06 and TNNP04 models, that spiral-wave dynamics depends sensitively on the amplitude and frequency of PD and the initial condition. We examine how these different types of spiral-wave states can be eliminated in the presence of PD by the application of low-amplitude pulses by square- and rectangular-mesh suppression techniques. We suggest specific experiments that can test the results of our simulations.

  5. Colorectal carcinoma evaluated by incremental dynamic CT; Comparison of CT density, histology, and tumor size

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, Hiroyoshi; Hara, Tsuyoshi; Taniguchi, Tetsushi (Shimizu Kosei Hospital, Shizuoka (Japan))

    1992-06-01

    Evaluation of incremental dynamic CT scan and histologic findings were compared in order to clarify the cause of the differences in colorectal carcinoma as observed on CT after administration of contrast medium. In 48 cases demonstrated on postcontrast dynamic CT scan, the CT density of the tumor was homogeneous (Type 1) in 26 (54.2%) cases and heterogeneous (Type 2) in 22 (45.8%) cases. Well differentiated adenocarcinoma was seen as Type 1 in 11 of 13 (84.6%) cases while moderately differentiated adenocarcinoma was of Type 1 in 15 of 29 (51.7%) cases. Poorly differentiated and mucinous adenocarcinoma were detected as Type 2 in all cases. A comparison of CT types and tumor size showed that as tumor size increased, the number of Type 1 cases decreased while Type 2 cases increased. Histologically, high density areas consisted mainly of well-developed tubular, branching glands of adenocarcinoma, while low density areas were composed of fibrous or mucinous stroma or necrosis. Dynamic CT scans for colorectal cancer are useful not only for preoperative staging but also for tissue characterization. (author).

  6. the Clinical Value of Spiral CT Diagnosis of Abdominal Hernia Applied%螺旋CT诊断应用于腹部疝中的临床价值

    Institute of Scientific and Technical Information of China (English)

    蒋宏华

    2013-01-01

    Objective Study and analysis of spiral CT diagnosis applied in abdominal hernia in the important clinical value. Methods The study object of study mainly for our 34 cases were treated abdominal hernia patients, and to all the research object of the clinical data were retrospectively analyzed. Results All patients with spiral CT diagnosis are more accurate. 34 cases of abdominal hernia patients, according to its hernia of the specific position, spiral CT diagnosed inguinal region hernia patients for 15 cases, umbilical hernia (3 cases), intraperitoneal hernia 4 cases, 2 cases of obturator hernia and traumatic abdominal wall hernia patients, 4 cases of abdominal incisional hernia patients 6 patients. Patients with abdominal hernia content of small intestine, Spiral CT performance under for intestinal obstruction of the patients in 34 cases, spiral CT diagnosis and surgical results of the coincidence rate is 100%. Conclusion For abdominal hernia patients is concerned, using spiral CT to carry on the diagnosis is very effective, it has the safe, convenient wait for a characteristic, can for clinical diagnosis and treatment to provide more substantial and reality basis.%  目的研究并分析螺旋CT诊断应用于腹部疝中的重要临床价值。方法本组研究的研究对象主要为我院收治的34例腹部疝患者,并对所有研究对象的临床资料进行回顾性分析。结果所有患者的螺旋CT诊断均较为准确。34例腹部疝患者中,根据其疝的具体位置,螺旋CT诊断出腹股沟区疝患者为15例、脐疝3例、腹腔内疝4例、闭孔疝2例和外伤性腹壁疝患者4例、腹壁切口疝患者6例。患者的腹部疝内容物为小肠;螺旋CT下表现为肠梗阻的患者为34例,螺旋CT的诊断与手术结果的符合率为100%。结论对于腹部疝的患者而言,运用螺旋CT来对其进行诊断是十分有效的,其具有安全、方便等特点,可以为临床的诊断与治疗提供较为可观与真实的依据。

  7. Prospectively Electrocardiogram-Gated High-Pitch Spiral Acquisition Mode Dual-Source CT Coronary Angiography in Patients with High Heart Rates: Comparison with Retrospective Electrocardiogram-Gated Spiral Acquisition Mode

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Kai; Ma, Rui; Wang, Li Jun [Dept. of Radiology, Baotou Central Hospital, Baotou (China); Li, Li Gang; Chen, Jiu Hong [CT BM Clinic Marketing, Siemens Healthcare, Beijing (China)

    2012-11-15

    To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 {+-} 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 {+-} 0.306 [group A] vs. 1.084 {+-} 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 {+-} 0.16 mSv in group A and 7.1 {+-} 1.05 mSv in group B (p = 0.001). In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.

  8. Comparison of application value between spiral CT and DR plain film in diagnosis of acetabulum fracture%对比螺旋 CT 与 DR 平片在髋臼骨折诊断中的应用价值

    Institute of Scientific and Technical Information of China (English)

    刘金全; 海忠; 崔凌; 郭锐

    2015-01-01

    目的:对比螺旋 CT 与 DR 平片在髋臼骨折诊断中的应用价值。方法58例髋臼骨折患者作为研究对象。所有患者均经手术证实为髋臼骨折,术前行螺旋 CT 与 DR 摄影,其中螺旋 CT 采用多平面重建(MPR)、三维表面重建(SSD)、容积重建(VR)等三维重建技术进行图像后处理,对比两种检查方案的诊断结果。结果CT 确诊髋臼骨折55例,高疑骨折3例, DR 确诊骨折42例,高疑8例,无骨折8例,两组确诊结果比较,差异有统计学意义(P<0.05);CT 诊断准确率更高。结论螺旋 CT 三维重建技术具有扫描快速、成像清晰的特点,在髋臼骨折诊断中具有重要的应用价值,较常规 DR 平片具有更高的确诊率,同时可有效评估患者骨折病情,为手术治疗方案提供指导。%Objective To compare the application value between spiral CT and DR plain film in diagnosis of acetabulum fracture. Methods There were 58 patients with acetabulum fracture as study subjects, and they were all diagnosed by operation. They received spiral CT and DR filming before operation. 3D reconstruction by multiple planar reconstruction (MPR), surface shading display (SSD), and volume reconstruction (VR) were applied for image postprocessing in spiral CT. Diagnosis results of the two examination methods were compared. Results CT showed 55 diagnosed acetabulum fracture cases and 3 highly suspected fracture cases. DR showed 42 diagnosed fracture cases, 8 highly suspected cases, and 8 cases without fracture. The difference between diagnosis results of the two groups had statistical significance (P<0.05). CT provided more accuracy in diagnosis. Conclusion Spiral CT 3D reconstruction method has advantages of quick scanning and clear imaging, and it contains important application value in diagnosis of acetabulum fracture. It provides higher diagnosis rate than common DR plain film with effective assessment of fracture condition, and it can

  9. Application of large aperture spiral CT in radiotherapy simulation positioning%大孔径螺旋CT在放疗模拟定位中的应用研究

    Institute of Scientific and Technical Information of China (English)

    李雪南; 修霞; 李高峰

    2013-01-01

    目的:探讨大孔径16排螺旋CT在放疗模拟定位中的应用。方法:应用大孔径16排螺旋CT进行乳腺癌保乳术后根治性放疗乳腺切线野的CT模拟定位,并对CT模拟定位技术与传统X射线模拟定位技术进行比较,同时与单排螺旋CT的图像进行比较。结果:大孔径16排螺旋CT在放疗模拟定位中的应用避免了因患者体位受限而造成的误差;大孔径16排螺旋CT模拟机的定位验证误差均优于传统X射线模拟机;其图像质量优于单排螺旋CT。结论:大孔径16排螺旋CT模拟定位机的应用,使得放疗定位更加精确,计划和治疗更加准确。%Objective:To discuss application of large aperture 16 row spiral CT in radiotherapy simulation positioning. Methods: To apply CT simulation positioning with large aperture 16 row spiral CT for the breast tangential field by early breast cancer after breast conserving surgery and radical radiotherapy. Compare CT-simulation and X-ray conventional positioning technique and Compare large aperture 16 row spiral CT and single row spiral CT image. Results: The application of large aperture 16 row spiral CT avoided the error because of body limited. Large aperture 16 row spiral CT simulation position validation error is superior to X-ray positioning. Its image quality is better than that of single row spiral CT. Conclusion:The application of large aperture 16 row spiral CT make simulation positioning more accurate, planned and treatment more accurate, it can provide guarantee of accurate simulation positioning for accurate plan and treatment.

  10. Value of negative spiral CT angiography in patients with suspected acute PE: analysis of PE occurrence and outcome

    Energy Technology Data Exchange (ETDEWEB)

    Krestan, C.R.; Klein, N.; Fleischmann, D.; Kaneider, A.; Kreuzer, S.; Riedl, C.; Herold, C.J. [Department of Radiology, University Hospital of Vienna-AKH, Waehringer Guertel 18-20, 1090, Vienna (Austria); Novotny, C. [Department of Nuclear Medicine, University Hospital of Vienna-AKH, Waehringer Guertel 18-20, 1090, Vienna (Austria); Minar, E. [Division of Angiology, Department of Internal Medicine, University Hospital of Vienna-AKH, Waehringer Guertel 18-20, 1090, Vienna (Austria); Janata, K. [Department of Emergency Medicine, University Hospital of Vienna-AKH, Waehringer Guertel 18-20, 1090, Vienna (Austria)

    2004-01-01

    The aim of this study was to analyze pulmonary embolism (PE) occurrence and retrospective clinical outcome in patients with clinically suspected acute PE and a negative spiral CT angiography (SCTA) of the pulmonary arteries. Within a 35-month period, 485 consecutive patients with clinical symptoms of acute PE underwent SCTA of the pulmonary arteries. Patients with a negative SCTA and without anticoagulation treatment were followed-up and formed the study group. Patient outcome and recurrence of PE was evaluated retrospectively during a period of 6 months after the initial SCTA, and included a review of computerized patient records, and interviews with physicians and patients. Patients were asked to fill out a questionnaire concerning all relevant questions about their medical history and clinical course during the follow-up period. Special attention was focused on symptoms indicating recurrent PE, as well as later confirmation and therapy of PE. Of the 485 patients, 325 patients (67%) had a negative scan, 134 (27.6%) had radiological signs of PE, and 26 (5.4%) had an indeterminant result. Of 325 patients with a negative scan, 269 (83%) were available for follow-up. The main reasons for loss to follow-up were change of address, name, or phone number, or non-resident patients who left abroad. Of 269 patients available for follow-up, 49 patients (18.2% of 269) received anticoagulant treatment because of prior or recent deep venous thrombosis (32.6%) or a history of PE (34.7%), cardiovascular disease (18.4%), high clinical probability (8.2%), positive ventilation-perfusion scan (4.2%), and elevated D-dimer test (2%). The remaining 220 patients, who did not receive anticoagulant medication, formed the study group. Of this study group, 1 patient died from myocardial infarction 6 weeks after the initial SCTA, and the postmortem examination also detected multiple peripheral emboli in both lungs (p=0.45%; 0.01-2.5, 95% confidence interval). The PE did not occur in any other

  11. Spiral CT diagnosis of extrarenal pelvis (report of 47 cases)%多层螺旋CT诊断肾外肾盂(附47例报告)

    Institute of Scientific and Technical Information of China (English)

    苗新中; 段青松

    2012-01-01

    Objective To study of extrarenal pelvis CT manifestation and differential diagnosis of extrarenal pelvis, to enhance understanding, and to avoid misdiagnosis. Methods We retrospectively analysed of 47 cases of renal pelvis CT axial scan, scan and three-dimensional reconstruction performance. Results In the CT axial scan, scan and three-dimensional reconstruction in the performance of in renal sinus cystic water density, CT enhancement contrast agent uniformly filling, three-dimensional reconstruction showed a more intuitive. There were 29 cases in bilateral side, 18 cases in unilal-erne side. Conclusion Spiral CT diagnosis of extrarenal pelvis is more accurate and reliable.%目的 研究肾外肾盂的CT表现和鉴别诊断,加强对肾外肾盂的认识,避免误诊发生.方法 回顾分析47例肾外型肾盂的CT轴位平扫、增强扫描及三维重建表现.结果 在CT轴位平扫、增强扫描及三维重建中表现为在肾窦外囊样水密度影,CT增强时对比剂均匀充盈,三维重建显示更直观.其中双侧29例,单侧18例.结论 多层螺旋CT诊断肾外肾盂更为准确可靠.

  12. Dynamical Relaxation of Coronal Magnetic Fields. III. 3D Spiral Nulls

    CERN Document Server

    Fuentes-Fernandez, Jorge

    2012-01-01

    Context: The majority of studies on stressed 3D magnetic null points consider magnetic reconnection driven by an external perturbation, but the formation of a genuine current sheet equilibrium remains poorly understood. This problem has been considered more extensively in two-dimensions, but lacks a generalization into 3D fields. Aims: 3D magnetic nulls are more complex than 2D nulls and the field can take a greater range of magnetic geometries local to the null. Here, we focus on one type and consider the dynamical non-resistive relaxation of 3D spiral nulls with initial spine-aligned current. We aim to provide a valid magnetohydrostatic equilibrium, and describe the electric current accumulations in various cases, involving a finite plasma pressure. Methods: A full MHD code is used, with the resistivity set to zero so that reconnection is not allowed, to run a series of experiments in which a perturbed spiral 3D null point is allowed to relax towards an equilibrium, via real, viscous damping forces. Changes...

  13. Dynamic CT in patients with normal pressure hydrocephalus

    Energy Technology Data Exchange (ETDEWEB)

    Horibe, Kunio; Akagi, Katsuhito; Go, Junto; Kohmura, Eiji; Yamazaki, Mami

    1984-11-01

    In order to elucidate the cerebral circulation before and after shunt in patients with normal pressure hydrocephalus(NPH), a comparative study of 12 cases was performed using dynamic CT. In the effective shunt group, blood flow in the frontal gray matter and PVL was improved. The improvement in PVL was particularly marked. On the other hand, in the non-effective group, blood flow in the frontal gray matter was reduced compared with that before operation. In regard to predicting the effectiveness of the shunt from the features of preoperative dynamic CT study in NPH, it is suggested that blood flow in the frontal gray matter was lower in the effective shunt group than in the non-effective group. This cerebral circulation study using dynamic CT, which can be easily manipulated, is non-invasive, and is thought to be a useful method when highly reproducible parameters are chosen. (Author).

  14. Pharyngolaryngeal tumors: spiral CT with 3D reconstruction; Tumeurs du pharyngo-larynx: apport de la tomodensitometrie en acquisition volumique avec reconstructions tridimensionnelles

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, V.; Troufleau, P.; Stines, J. [Centre de Lutte Contre le Cancer, 54 - Nancy (France); Regent, D. [Centre Hospitalier Universitaire, 54 - Nancy (France)

    1995-04-01

    Spiral CT allows the exploration of the whole larynx and hypopharynx in 30 seconds. This is a good adjustment between the technique and the organ. Performed on 15 patients during a 30 seconds Valsalva maneuver, the exploration yields results from good to excellent. In two cases, conventional and helical CT are compared. The limitation of mA is not a drawback in such a thin region and there is no shift of organ or lesion between two scans, because the whole range is scanned in a single breathhold. 3D display of larynx and pharynx can performed with some advantage, especially easiness of presentation for surgeon. They help topographic analysis and make correlation between endoscopic views and axial scans. They could be useful for surgical simulation and 3D photon treatment plannings. (authors). 17 refs., 17 figs.

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

    Institute of Scientific and Technical Information of China (English)

    Xiaohua Chen; Fengxian Deng; Shuhang Wei; Tingsong Fang

    2006-01-01

    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.DESTGN: A repetitive observation and measurement.SETTINGS: Department of Neurosurgery and Department of Medical Imaging, Foshan Hospital of Traditional Chinese Medicine.PARTICTPANTS: 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 cistern. 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

  16. Spiral CT and optimization of the modalities of the iodinated intravenous contrast material: Experimental studies in human pathology; Tomodensitometrie spiralee et optimisation des protocoles d'injection du contraste iode intra-veineux: etudes experimentales en pathologie humaine

    Energy Technology Data Exchange (ETDEWEB)

    Bonaldi, V

    1998-06-19

    Spiral (or helical) CT represents the most recent improvement in the field of computed assisted tomography (CAT scan). The capabilities of this new imaging modality are much superior to these of conventional CT scanning; then result from the rapid acquisition and from the volumetric nature of the derived data set. The short time of data acquisition had made mandatory the revision of protocols for intravenous administration of iodinated contrast material. By the means of several studies, carried out on pathologic and healthy patients, we have attempted to improve knowledge in factors influencing CT attenuation values after injection of contrast material, in the aim of improving contrast administration performed during spiral CT scanning. Anatomical landmarks that we have studied till now have been liver, the pancreas, the kidney and the cervical spine. In addition, a paired based methodology has been used. The volumetric set of data derived from spiral CT scanning leads to optimal post-processing tasks, the most interesting being related to cine-display and multiplanar reformatting; both modalities have been evaluated, about the pancreas and the musculo-skeletal system respectively. Conversely, this new modality, as for other imaging modalities, is responsible for additional costs derived from restless increase in the number of images to be dealt with and from the occurrence of new tasks (in post-processing particularly). The place of spiral CT in diagnostic strategies among other modern imaging modalities should be assessed, especially with respect to Magnetic Resonance Imaging (MRI). (author)

  17. Detection of tibial condylar fractures using 3D imaging with a mobile image amplifier (Siemens ISO-C-3D): Comparison with plain films and spiral CT; Frakturdiagnostik am Kniegelenk mit einem neuen mobilen CT-System (ISO-C-3D): Vergleich mit konventionellem Roentgen und Spiral-CT

    Energy Technology Data Exchange (ETDEWEB)

    Kotsianos, D.; Rock, C.; Wirth, S.; Linsenmaier, U.; Brandl, R.; Fischer, T.; Pfeifer, K.J.; Reiser, M. [Klinikum der Universitaet Muenchen-Innenstadt, Muenchen (Germany). Inst. fuer Klinische Radiologie; Euler, E.; Mutschler, W. [Klinikum der Universitaet Muenchen-Innenstadt, Muenchen (Germany). Chirurgische Klinik und Poliklinik

    2002-01-01

    Purpose: To analyze a prototype mobile C-arm 3D image amplifier in the detection and classification of experimental tibial condylar fractures with multiplanar reconstructions (MPR). Method: Human knee specimens (n=22) with tibial condylar fractures were examined with a prototype C-arm (ISO-C-3D, Siemens AG), plain films (CR) and spiral CT (CT). The motorized C-arm provides fluoroscopic images during a 190 orbital rotation computing a 119 mm data cube. From these 3D data sets MP reconstructions were obtained. All images were evaluated by four independent readers for the detection and assessment of fracture lines. All fractures were classified according to the Mueller AO classification. To confirm the results, the specimens were finally surgically dissected. Results: 97% of the tibial condylar fractures were easily seen and correctly classified according to the Mueller AO classification on MP reconstruction of the ISO-C-3D. There is no significant difference between ISO-C and CT in detection and correct classification of fractures, but ISO-CD-3D is significant by better than CR. (orig.) [German] Zielsetzung: Ziel der vorliegenden Studie war es, die diagnostischen Moeglichkeiten und Grenzen der Erkennbarkeit und Klassifizierung von Frakturen mit multiplanaren Rekonstruktionen (MPR) aus 3D-Datensaetzen eines fahrbaren C-Bogengeraetes an Kniegelenken zu pruefen. Methodik: Kniegelenke von Verstorbenen (n=22) mit Tibiakopffrakturen wurden an einem Prototyp eines mobilen C-Bogen Schnittbild-/Durchleuchtungsgeraets (ISO-C-3D, Siemens AG Erlangen) untersucht. Das Geraet erzeugt waehrend einer einmaligen 190-Grad-Rotation 100 Projektionsaufnahmen, aus denen ein 3D-Volumendatensatz gewonnen wird. Aus diesem werden Hochkontrastschnittbilder als MP-Rekonstruktionen in allen drei Raumebenen errechnet und visualisiert. Die Kniegelenke wurden von 4 unabhaengigen Befundern hinsichtlich Frakturerkennbarkeit, Frakturart und -ausmass unter Verwendung der MP

  18. Value of spiral CT in the diagnosis of osteoid osteoma%螺旋CT对骨样骨瘤的诊断价值探讨

    Institute of Scientific and Technical Information of China (English)

    吴泽文; 吴信南; 陈焱君; 胡剑波

    2012-01-01

    Objective To analyze the value of the spiral CT in the diagnosis of osteoid osteoma. Methods 12 patients with osteoid osteoma proved by surgical pathology and the imaging of X-ray and spiral CT scan were retrospectively analyzed. Results Among the 12 cases, 6 cases of lesions in the femur and 2 cases in the tibia, 2 cases in the humerus and 2 cases in the other parts. CT showed the nidus and surrounding of the nidus with the different levels of hardening, and the nidus showed a round or oval translucent area with a diameter of 3~16mm. mean 9. 0mm, 7 cases wiht the center calcification. Conclusion Nidus is the key to diagnosis of osteoid osteoma, spiral CT scan shows nidus is the preferred method of examination in the diagnosis of osteoid osteoma.%目的 探讨螺旋CT在骨样骨瘤中的诊断价值.方法 对12例经病理证实且行X线和螺旋CT扫描检查的骨样骨瘤病人的影像学表现进行回顾性分析.结果 12例患者中,病灶位于股骨6例、胫骨2例、肱骨2例和其它部位2例.CT表现为瘤巢及其周围形成程度不同的反应性骨质硬化,瘤巢表现为一圆形或卵圆形的透亮区,直径为3~16mm,平均9.0mm,中心有钙化7例.结论 瘤巢是确诊骨样骨瘤的关键;螺旋CT扫描是显示瘤巢的首选检查方法,在骨样骨瘤诊断中具有重要的价值.

  19. Dynamic CT of tuberculous meningeal reactions

    Energy Technology Data Exchange (ETDEWEB)

    Jinkins, J.R.

    1987-07-01

    The technique of intravenous dynamic cranial computed tomography has been applied to the patient population at this location in Saudi Arabia with meningeal tuberculosis. The various manifestations and sequelae including meningitis, arteritis, infarct, and true meningeal tuberculomata all have characteristic if not specific appearances. The dynamic study enhances an otherwise static examination and reveals a great deal about the pathophysiology of tuberculosis involving the cerebral meningeal surfaces.

  20. Measurement of cardiac output from dynamic pulmonary circulation time CT

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Seonghwan, E-mail: Seonghwan.Yee@Beaumont.edu [Department of Radiation Oncology, Beaumont Health System, Royal Oak, Michigan 48073 (United States); Scalzetti, Ernest M. [Department of Radiology, SUNY Upstate Medical University, Syracuse, New York 13210 (United States)

    2014-06-15

    Purpose: To introduce a method of estimating cardiac output from the dynamic pulmonary circulation time CT that is primarily used to determine the optimal time window of CT pulmonary angiography (CTPA). Methods: Dynamic pulmonary circulation time CT series, acquired for eight patients, were retrospectively analyzed. The dynamic CT series was acquired, prior to the main CTPA, in cine mode (1 frame/s) for a single slice at the level of the main pulmonary artery covering the cross sections of ascending aorta (AA) and descending aorta (DA) during the infusion of iodinated contrast. The time series of contrast changes obtained for DA, which is the downstream of AA, was assumed to be related to the time series for AA by the convolution with a delay function. The delay time constant in the delay function, representing the average time interval between the cross sections of AA and DA, was determined by least square error fitting between the convoluted AA time series and the DA time series. The cardiac output was then calculated by dividing the volume of the aortic arch between the cross sections of AA and DA (estimated from the single slice CT image) by the average time interval, and multiplying the result by a correction factor. Results: The mean cardiac output value for the six patients was 5.11 (l/min) (with a standard deviation of 1.57 l/min), which is in good agreement with the literature value; the data for the other two patients were too noisy for processing. Conclusions: The dynamic single-slice pulmonary circulation time CT series also can be used to estimate cardiac output.

  1. Dynamic CT head phantom for perfusion and angiography studies

    Science.gov (United States)

    Russell, K.; Blazeski, A.; Dannecker, K.; Lee, Q. Y.; Holscher, C.; Donahue, C.; van Kampen, W.

    2010-03-01

    Contrast imaging is a compelling enhancement for the portable, flat panel-based brain CT scanner currently under development at Xoran. Due to the relative low temporal resolution of flat panel detectors, enabling tomographic imaging on such platform requires optimizing the imaging and injection protocols. A dynamic CT head phantom was designed to facilitate this task. The Dynamic Perfusion and Angiography Model (PAM), mimics tissue attenuation in CT images, provides physiological timing for angiography and perfusion studies, and moves fluid with properties similar to those of blood. The design consists of an arterial system, which contains bifurcating vessels that feed into perfusion chambers, mimicking blood flow through capillaries and smaller vessels, and a venous system, which is symmetrical to the arterial side and drains the perfusion chambers. The variation of geometry and flow rate in the phantom provides the physiological total time that fluid spends in the head, and the difference in material densities correlates to CT numbers for biological tissues. This paper discusses the design of Dynamic PAM and shows experimental results demonstrating its ability to realistically simulate blood flow. Results of dynamic imaging studies of the phantom are also presented.

  2. Elimination of spiral waves in a locally connected chaotic neural network by a dynamic phase space constraint.

    Science.gov (United States)

    Li, Yang; Oku, Makito; He, Guoguang; Aihara, Kazuyuki

    2017-01-16

    In this study, a method is proposed that eliminates spiral waves in a locally connected chaotic neural network (CNN) under some simplified conditions, using a dynamic phase space constraint (DPSC) as a control method. In this method, a control signal is constructed from the feedback internal states of the neurons to detect phase singularities based on their amplitude reduction, before modulating a threshold value to truncate the refractory internal states of the neurons and terminate the spirals. Simulations showed that with appropriate parameter settings, the network was directed from a spiral wave state into either a plane wave (PW) state or a synchronized oscillation (SO) state, where the control vanished automatically and left the original CNN model unaltered. Each type of state had a characteristic oscillation frequency, where spiral wave states had the highest, and the intra-control dynamics was dominated by low-frequency components, thereby indicating slow adjustments to the state variables. In addition, the PW-inducing and SO-inducing control processes were distinct, where the former generally had longer durations but smaller average proportions of affected neurons in the network. Furthermore, variations in the control parameter allowed partial selectivity of the control results, which were accompanied by modulation of the control processes. The results of this study broaden the applicability of DPSC to chaos control and they may also facilitate the utilization of locally connected CNNs in memory retrieval and the exploration of traveling wave dynamics in biological neural networks.

  3. Application of Spiral CT angiography for the diagnosis of Moyamoya disease%螺旋CT在Moyamoya病诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    张小安; 赵鑫; 曲金荣; 李树新; 程敬亮; 李瑞娟

    2002-01-01

    目的:探讨螺旋CT(spiral CT,SCT)和螺旋CT血管造影(spiral CT angiography,SCTA)对Moyamoya病的诊断价值.方法:回顾性分析10例Moyamoya病患者的SCTA表现.其中男4例女6例,年龄9岁~42岁,其中14岁以下者7例,应用Picker SeleSp螺旋CT扫描仪行常规SCT平扫,然后采用螺旋CT扫描方式进行SCTA原始图像数据采集,其中3例有DSA,6例有MRI,另外随机选择10例SCT和SCTA正常者作为对照组.结果:10例病人横断面均见丘脑基底节区扩张的脑血管,即烟雾血管.10例SCrA和3例DSA显示颈内动脉(ICA)上段或大脑中动脉(MCA),大脑前动脉(ACA)近端闭塞以及丘脑基底节区Moyamoya血管,这些病理血管分布与SE序列MRI一致,对照组均见不到丘脑基底节区正常细小的穿支血管.结论:SCTA有望成为诊断Moyamoya病的又一有效的非创伤性方法.

  4. The role of whole body spiral CT in the primary work-up of polytrauma patients - comparison with conventional radiography and abdominal sonography; Die Rolle der Ganzkoerper-Spiral-CT bei der Primaerdiagnostik polytraumatisierter Patienten - Vergleich mit konventioneller Radiographie und Abdomensonographie

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, T.; Schlippenbach, J. von; Wolf, K.J. [Klinik und Poliklinik fuer Radiologie und Nuklearmedizin, Charite - Campus Benjamin Franklin (Germany); Stahel, P.F.; Ertel, W. [Klinik fuer Unfall- und Wiederherstellungschirurgie, Charite - Campus Benjamin Franklin (Germany)

    2004-08-01

    Purpose: To evaluate the role of routine 'whole body spiral CT' in the primary work-up of polytrauma patients for injuries of the thorax, abdomen and spine, and to compare the results with those of conventional radiography of the chest and spine and abdominal ultrasound. Materials and Methods: Fifty consecutive polytrauma patients underwent contrast-enhanced single slice spiral CT (5 mm collimation) from the vertex to the floor of the pelvis as part of the primary work-up after emergency room admission. Overlapping high resolution sections and sagittal reformations of the spine were obtained. Reports of additional chest radiographs (n=43), abdominal ultrasound examinations (n=47) and spine radiographs (n=36) performed in the emergency room were available for retrospective comparison. The 'final diagnoses', which served as the standard of reference, were taken from the patients' records using all information that became available until discharge or death, such as findings from further imaging, surgery and autopsy. Results: CT showed 109 (97%) of 112 thoracic and abdominal soft-tissue injuries. Relevant injuries missed were an early splenic laceration and an early pelvic hematoma, both of which became clinically apparent several hours later. There were 4 false positive CT findings. Conventional chest radiography demonstrated only 20% of thoracic and sonography 22% of abdominal injuries. Chest radiography and sonography produced 2 false-positive findings each. CT showed 66 (87%) of 76 vertebral fractures including all 19 unstable ones. CT missed 5 anterior vertebral body and 5 spinous/transverse process fractures. Conventional radiography found 71% of vertebral fractures including only 50% of the unstable one. (orig.)

  5. Orbital Data Confirms Dynamic Fractal Firework Universe Having 3D-spiral Code

    CERN Document Server

    Savov, E P

    2005-01-01

    The understanding of the universe is confused by the unknown nature of about 95% of its matter, required to confine the motions of space objects in cosmic structures. The proposed self-similar transformations of one all-building basic matter suggest that the universe is dynamic fractal that has 3D-spiral code. Its dynamic fractal elements create unifying force described by equation of the unifying interaction, drawn in the new fundamental dynamic fractal framework. The equation of unifying interaction converges into the inverse square laws and the principle of uncertainty at laboratory scales. It is further confirmed with calculations based on the orbital data of bodies moving around the nucleus of the Milky Way Galaxy, the centers of the Earth and the Sun and also orbiting the 87 Sylvia asteroid. Some of the testable predictions say that 87 Sylvia will have density > 1.2 g/cm2 and variations in gravity force less or comparable to 5.4 x 10exp(-4) m/s2, having space scales less or comparable to 10exp(3) km, wi...

  6. Clinical applications for multiplanar- and three-dimensional-reconstructions by helical-CT for the diagnosis of acetabular fractures; Klinischer Einsatz multiplanarer und 3D-Rekonstruktionen der Spiral-CT in der Diagnostik der Azetabulumfrakturen

    Energy Technology Data Exchange (ETDEWEB)

    Stroszczynski, C. [Strahlenklinik und Poliklinik im Virchow-Klinikum, Medizinische Fakultaet der Humboldt-Universitaet, Berlin (Germany); Schedel, H. [Strahlenklinik und Poliklinik im Virchow-Klinikum, Medizinische Fakultaet der Humboldt-Universitaet, Berlin (Germany); Stoeckle, U. [Unfallchirurgische Klinik und Poliklinik im Virchow-Klinikum, Medizinische Fakultaet der Humboldt-Universitaet, Berlin (Germany); Wellmann, A. [Strahlenklinik und Poliklinik im Virchow-Klinikum, Medizinische Fakultaet der Humboldt-Universitaet, Berlin (Germany); Beier, J. [Deutsches Herzzentrum Berlin, Virchow-Klinikum, Abt. Innere Medizin und Kardiologie (Germany); Wicht, L. [Strahlenklinik und Poliklinik im Virchow-Klinikum, Medizinische Fakultaet der Humboldt-Universitaet, Berlin (Germany); Hoffmann, R. [Unfallchirurgische Klinik und Poliklinik im Virchow-Klinikum, Medizinische Fakultaet der Humboldt-Universitaet, Berlin (Germany); Felix, R. [Strahlenklinik und Poliklinik im Virchow-Klinikum, Medizinische Fakultaet der Humboldt-Universitaet, Berlin (Germany)

    1996-03-01

    This review describes recent visualizations of computed tomography for the diagnosis of acetabular fractures. The techniques of conventional and helical-CT for the imaging of the acetabulum are compared. Furthermore, the different methods of multiplaner and three-dimensional reconstructions e.g. shaded surface display, maximum intensity projection, and volume rendering are presented. Figures of multiplanar and three-dimensional imaging for fractures of the pelvis is discussed. (orig.) [Deutsch] Es wird eine Uebersicht moderner computertomographischer Darstellungsmethoden der Azetabulumfrakturen vorgestellt. Auf die einzelnen Charaktersitika der konventionellen und Spiral-CT-Technik wird eingegangen, weiterhin werden die multiplanaren und verschiedenen 3dimensionalen Rekonstruktionsverfahren Shaded-Surface-Display (SSD), Maximum-Intensitaetsprojektion (MIP) und Volume-Rendering (VR) beschrieben und jeweils anhand von Abbildungen erlaeutert. Darueber hinaus wird das diagnostische Potential der einzelnen Methoden diskutiert. (orig.)

  7. Value of multi-slice spiral CT in the diagnosis of small hepatocellular carcinoma%多排螺旋CT灌注成像对小肝癌诊断价值

    Institute of Scientific and Technical Information of China (English)

    王恩峰; 陈文军; 苏保民; 程明; 赵新宇; 张立彬; 王丽梅

    2012-01-01

    Objective To study the diagnostic value of multi-slice spiral CT (MSCT) dynamic contrast-enhanced perfusion imaging in small hepatocellular carcinoma (SHCC) and improve the diagnostic accuracy of SHCC. Methods Multi-slice spiral CT dynamic contrast-enhanced perfusion imaging was used in 23 patients with SHCC, and the time-density curve(T-DC) were gotten. Blood flow( BF) , blood volume ( BV ) , hepatic arterial fraction ( HAF) , mean transit time(MTT) , permeability surface (PS) and time of arrival of SHCC and liver parenchyma were measured, and the colored perfusion maps for each of the above-mentioned parameters were acquired. Also the receiver operating characteristic curves ( ROC) were analyzed. Results SHCC showed BF,BV and HAF higher than those of the liver parenchyma(P 0. 05). T-DC of SHCC was fast rise, and its peak was significantly earlier than the liver parenchyma. Especially in hepatic arterial fraction determination, when ROC critical value was set to 0. 31, the sensitivity and specificity can be achieved respectively 100% and 90%. Conclusion Hepatic CT perfusion imaging is important for the diagnosis of small hepatocellular carcinoma.%目的 研究多排螺旋CT(multi-slice spiral CT,MSCT)动态增强灌注成像对小肝癌(small hepatocellular carcinoma,SHCC)的诊断价值,提高SHCC的诊断准确率.方法 使用多排螺旋CT对23例小肝癌患者行动态增强灌注成像,生成时间-密度曲线(time-density curve,T-DC),测量肝癌病灶及肝实质的CT灌注值包括血流量(blood flow,BF)、血容量(blood volume,BV)、肝动脉分数(hepatic arterial fractin,HAF),平均通过时间(mean transit time,MTT)、血管表面通透性(permeability suface,PS)和对比剂到达时间,并获得相应的灌注伪彩图.分析接受者工作特征曲线(receiver operating characterisic curves,ROC).结果 小肝癌血流量、血容量及肝动脉分数值均明显高于肝实质(P<0.05),其它的灌注值在两者

  8. Magnetohydrodynamics dynamical relaxation of coronal magnetic fields. III. 3D spiral nulls

    Science.gov (United States)

    Fuentes-Fernández, J.; Parnell, C. E.

    2012-08-01

    Context. The majority of studies on stressed 3D magnetic null points consider magnetic reconnection driven by an external perturbation, but the formation of a genuine current sheet equilibrium remains poorly understood. This problem has been considered more extensively in two dimensions, but lacks a generalization into 3D fields. Aims: 3D magnetic nulls are more complex than 2D nulls and the field can take a greater range of magnetic geometries local to the null. Here, we focus on one type and consider the dynamical non-resistive relaxation of 3D spiral nulls with initial spine-aligned current. We aim to provide a valid magnetohydrostatic equilibrium, and describe the electric current accumulations in various cases, involving a finite plasma pressure. Methods: A full MHD code was used, with the resistivity set to zero so that reconnection is not allowed, to run a series of experiments in which a perturbed spiral 3D null point was allowed to relax towards an equilibrium via real, viscous damping forces. Changes to the initial plasma pressure and other magnetic parameters were systematically investigated. Results: For the axisymmetric case, the evolution of the field and the plasma is such that it concentrates the current density into two cone-shaped regions along the spine, thus concentrating the twist of the magnetic field around the spine, leaving a radial configuration in the fan plane. The plasma pressure redistributes to maintain the current density accumulations. However, it is found that changes in the initial plasma pressure do not significantly modify the final state. In the cases where the initial magnetic field is not axisymmetric, an infinite-time singularity of current perpendicular to the fan is found at the location of the null.

  9. Diagnostic image quality of a comprehensive high-pitch dual-spiral cardiothoracic CT protocol in patients with undifferentiated acute chest pain

    Energy Technology Data Exchange (ETDEWEB)

    Bamberg, Fabian, E-mail: fbamberg@med.lmu.de [Department of Clinical Radiology, Ludwig-Maximilians University, Klinikum Grosshadern, Munich (Germany); Marcus, Roy; Sommer, Wieland; Schwarz, Florian; Nikolaou, Konstantin; Becker, Christoph R.; Reiser, Maximilian F.; Johnson, Thorsten R.C. [Department of Clinical Radiology, Ludwig-Maximilians University, Klinikum Grosshadern, Munich (Germany)

    2012-12-15

    Objective: To evaluate diagnostic image quality of high-pitch dual source comprehensive cardiothoracic CT protocol in patients presenting with acute undifferentiated chest pain. Materials and methods: Consecutive symptomatic subjects (n = 51) with undifferentiated acute chest pain underwent ECG-synchronized high-pitch dual-spiral chest CT angiography (Definition Flash, Siemens Medical Solutions, 2 × 100 kVp or 2 × 120 kV if BMI > 30, collimation: 128 × 0.6 mm, pitch: 3.2). Independent investigators determined the image quality of each cardiac and pulmonary vessel segment, measured contrast-to-noise-ratio (CNR), and determined radiation exposure. In addition, the prevalence of CT findings (pulmonary embolism (PE), aortic dissection (AD) and significant coronary stenosis (≥50%)) was determined. Univariate and multivariate analysis were performed to determine the subpopulation with highest diagnostic quality. Results: Among 51 subjects (66% male, average age: 63 ± 15.8), the prevalence of positive CT findings was moderate (overall: 11.7%). Overall, image quality of the pulmonary, aortic and coronary vasculature was good (1.26 ± 0.43 and CNR: 2.52) with an average radiation dose of 3.82 mSv and 3.2% of segments rated non-evaluable. The image quality was lowest in the coronary arteries (p = 0.02), depending on the heart rate (r = 0.52, p < 0.001). In subjects with a heart rate of ≤65 bpm (n = 30) subjective image quality and CNR of the coronary arteries were higher (1.6 ± 0.5 vs. 2.1 ± 0.5, p = 0.03 and 1.21 ± 0.3 vs. 1.02 ± 0.3, p = 0.05) with only 1.5% segments classified as non-evaluable. Conclusion: High-pitch dual-spiral comprehensive cardiothoracic CT provides low radiation exposure with excellent image quality at heart rates ≤65 bpm. In subjects with higher heart rates, image quality of the aortic and pulmonary vasculature remains excellent, while the assessment of the coronary arteries degrades substantially.

  10. Dynamic CT perfusion measurement in a cardiac phantom.

    Science.gov (United States)

    Ziemer, Benjamin P; Hubbard, Logan; Lipinski, Jerry; Molloi, Sabee

    2015-10-01

    Widespread clinical implementation of dynamic CT myocardial perfusion has been hampered by its limited accuracy and high radiation dose. The purpose of this study was to evaluate the accuracy and radiation dose reduction of a dynamic CT myocardial perfusion technique based on first pass analysis (FPA). To test the FPA technique, a pulsatile pump was used to generate known perfusion rates in a range of 0.96-2.49 mL/min/g. All the known perfusion rates were determined using an ultrasonic flow probe and the known mass of the perfusion volume. FPA and maximum slope model (MSM) perfusion rates were measured using volume scans acquired from a 320-slice CT scanner, and then compared to the known perfusion rates. The measured perfusion using FPA (P(FPA)), with two volume scans, and the maximum slope model (P(MSM)) were related to known perfusion (P(K)) by P(FPA) = 0.91P(K) + 0.06 (r = 0.98) and P(MSM) = 0.25P(K) - 0.02 (r = 0.96), respectively. The standard error of estimate for the FPA technique, using two volume scans, and the MSM was 0.14 and 0.30 mL/min/g, respectively. The estimated radiation dose required for the FPA technique with two volume scans and the MSM was 2.6 and 11.7-17.5 mSv, respectively. Therefore, the FPA technique can yield accurate perfusion measurements using as few as two volume scans, corresponding to approximately a factor of four reductions in radiation dose as compared with the currently available MSM. In conclusion, the results of the study indicate that the FPA technique can make accurate dynamic CT perfusion measurements over a range of clinically relevant perfusion rates, while substantially reducing radiation dose, as compared to currently available dynamic CT perfusion techniques.

  11. Diagnostic efficacy of gadoxetic acid (Primovist)-enhanced MRI and spiral CT for a therapeutic strategy: comparison with intraoperative and histopathologic findings in focal liver lesions

    Energy Technology Data Exchange (ETDEWEB)

    Hammerstingl, Renate; Vogl, Thomas J. [Johann Wolfgang Goethe-Univ., Inst. of Diagnostic and Interventional Radiology, Frankfurt am Main (Germany); Huppertz, Alexander [Imaging Science Inst., Charite - Siemens, Berlin (Germany); Breuer, Josy; Balzer, Thomas [Gobal Clinical Development Diagnostics, Bayer Schering Pharma AG, Berlin (Germany); Blakeborough, Anthony [Royal Hallamshire Hospital, Dept. of Radiology, Sheffield (United Kingdom); Carter, Rick [Bayer Health Care Ltd., Burgess Hill, West Sussex (United Kingdom); Castells Fuste, Lluis [Hospital Vall d' Hebron, Liver Unit, Dept. of Internal Medicine, Barcelona (Spain); Heinz-Peer, Gertraud [Universitaetsklinik fuer Radiodiagnostik, Allg. Krankenhaus der Stadt Wien, Wien (Germany); Judmaier, Werner [Univ. Hospital Innsbruck, Dept. of Magnetic Resonance Imaging and Spectroscopy, Innsbruck (Austria); Laniado, Michael [Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden, Inst. for Diagnostic Radiology, Dresden (Germany); Manfredi, Riccardo M. [Univ. of Verona, Dept. of Radiology, Verona (Italy); Mathieu, Didier G. [Centre d' Imagerie, Aix en Provence (France); Mueller, Dieter [Georg-August Univ., Dept. of Radiology, Goettingen (Germany); Mortele, Koenraad [Brigham and Women' s Hospital, Dept. of Radiology (L1), Boston, MA (United States); Reimer, Peter [Klinikum Karlsruhe, Dept. of Radiology, Karlsruhe (Germany); Reiser, Maximilian F. [Ludwig-Maximilians-Univ. Munich - Klinikum Grosshadern, Inst. of Clinical Radiology, Munich (Germany); Robinson, Philip J. [St James' s Univ. Hospital, Dept. of Clinical Radiology, Leeds (United Kingdom); Shamsi, Kohkan [Berlex Labs. Inc., Montville, NJ (United States); Strotzer, Michael [Univ. Hospital, Dept. of Diagnostic Radiology, Regensburg (Germany); Taupitz, Matthias [Universitaetsklinikum Charite, Med. Fakultaet der Humboldt-Univ., Dept. of Radiology, Berlin (Germany); Tombach, Bernd; Valeri, Gianluca; Beers, Bernhard E. van [and others

    2008-03-15

    A multicenter study has been employed to evaluate the diagnostic efficacy of magnetic resonance imaging (MRI) using the new liver-specific contrast agent gadoxetic acid (Gd-EOB-DTPA, Primovist), as opposed to contrast-enhanced biphasic spiral computed tomography (CT), in the diagnosis of focal liver lesions, compared with a standard of reference (SOR). One hundred and sixty-nine patients with hepatic lesions eligible for surgery underwent Gd-EOB-DTPA-enhanced MRI as well as CT within 6 weeks. Pathologic evaluation of the liver specimen combined with intraoperative ultrasound established the SOR. Data sets were evaluated on-site (14 investigators) and off-site (three independent blinded readers). Gd-EOB-DTPA was well tolerated. Three hundred and two lesions were detected in 131 patients valid for analysis by SOR. The frequency of correctly detected lesions was significantly higher on Gd-EOB-DTPA-enhanced MRI compared with CT in the clinical evaluation [10.44%; 95% confidence interval (CI): 4.88, 16.0]. In the blinded reading there was a trend towards Gd-EOB-DTPA-enhanced MRI, not reaching statistical significance (2.14%; 95% CI: -4.32, 8.6). However, the highest rate of correctly detected lesions with a diameter below 1 cm was achieved by Gd-EOB-DTPA-enhanced MRI. Differential diagnosis was superior for Gd-EOB-DTPA-enhanced MRI (82.1%) versus CT (71.0%). A change in surgical therapy was documented in 19 of 131 patients (14.5%) post Gd-EOB-DTPA-enhanced MRI. Gd-EOB-DTPA-enhanced MRI was superior in the diagnosis and therapeutic management of focal liver lesions compared with CT. (orig.)

  12. Finite Element Analysis of the Misalignment Effects on the Dynamic Force Coefficients of Spiral Groove Gas Face Seals

    Science.gov (United States)

    Faria, Marco Tulio C.

    This paper presents a finite element procedure specially devised to analyze the misalignment effects on the behavior of spiral groove gas face seals operating at high speeds. In this study, the seal stationary face is slightly misaligned and the flexibly mounted face is perfectly aligned. Predictions of some steady-state and dynamic performance characteristics versus misalignment angle are presented for spirally grooved gas seals operating under stringent conditions. Curves of dynamic force coefficients versus the static misalignment angle of the seal face indicate that the seal misalignment affects considerably the dynamic response of gas lubricated face seals. At high speeds, the static seal misalignment not only results in increased stiffness coefficients but also leads to negative damping coefficients, which may be a sign of the seal susceptibility to excessive angular motions.

  13. Dynamic contrast-enhanced CT in patients with pancreatic cancer

    DEFF Research Database (Denmark)

    Lauridsen, Carsten Ammitzbøl; Eriksen, Rie Østbjerg; Strauch, Louise Søborg;

    2016-01-01

    tissue, compared with measurements in pancreatic tissue outside of tumor, or normal pancreatic tissue in control groups of healthy volunteers. The studies were heterogeneous in the number of patients enrolled and scan protocols. Perfusion parameters measured and analyzed by DCE-CT might be useful......The aim of this systematic review is to provide an overview of the use of Dynamic contrast-enhanced Computed Tomography (DCE-CT) in patients with pancreatic cancer. This study was composed according to the PRISMA guidelines 2009. The literature search was conducted in PubMed, Cochrane Library...... in the investigation of characteristic vascular patterns of pancreatic exocrine tumors. Further clinical studies are desired for investigating the potential of DCE-CT in pancreatic tumors. Keywords:...

  14. Circumnuclear star-forming regions in early type spiral galaxies: dynamical masses

    CERN Document Server

    Hagele, G F; Bosch, G L; Diaz, A I; Terlevich, E; Terlevich, R

    2012-01-01

    We present the measurements of gas and stellar velocity dispersions in 17 circumnuclear star-forming regions (CNSFRs) and the nuclei of three barred spiral galaxies: NGC2903, NGC3310 and NGC3351 from high dispersion spectra. The stellar dispersions have been obtained from the CaII triplet (CaT) lines at 8494, 8542, 8662A, while the gas velocity dispersions have been measured by Gaussian fits to the Hbeta and to the [OIII]5007A\\ lines. The CNSFRs, with sizes of about 100 to 150pc in diameter, are seen to be composed of several individual star clusters with sizes between 1.5 and 6.2pc on HST images. Using the stellar velocity dispersions, we have derived dynamical masses for the entire star-forming complexes and for the individual star clusters. Values of the stellar velocity dispersions are between 31 and 73 km/s. Dynamical masses for the whole CNSFRs are between 4.9x10^6 and 1.9x10^8 Mo and between 1.4x10^6 and 1.1x10^7 Mo for the individual star clusters. We have found indications for the presence of two dif...

  15. Dynamical behaviour of non newtonian spiral blood flow through arterial stenosis

    Science.gov (United States)

    Ali, Mohammad; Mahmudul Hasan, Md.; Alam Maruf, Mahbub

    2017-04-01

    The spiral component of blood flow has both beneficial and detrimental effects in human circulatory system. A numerical investigation is carried out to analyze the effects of spiral blood flow through an axisymmetric three dimensional artery having 75% stenosis at the center. Blood is assumed as a non-Newtonian fluid. Standard k-ω model is used for the simulation with the Reynolds number of 1000. A parabolic velocity profile with spiral flow is used as inlet boundary condition. The peak values of all velocity components are found just after stenosis. But total pressure gradually decreases at downstream. Spiral flow of blood has significant effects on tangential component of velocity. However, the effect is mild for radial and axial velocity components. The peak value of wall shear stress is at the stenosis zone and decreases rapidly in downstream. The effect of spiral flow is significant for turbulent kinetic energy. Detailed investigation and relevant pathological issues are delineated throughout the paper.

  16. The analysis of diagnostic value of 64-slice spiral CT in acute mesenteric vascular embolism%64层螺旋CT对急性肠系膜血管栓塞的诊断价值分析

    Institute of Scientific and Technical Information of China (English)

    张浩亮; 杜海; 武轶非; 张凤翔

    2012-01-01

    目的 探讨64层螺旋CT血管造影对急性肠系膜血管栓塞(AMI)的诊断价值.方法 回顾性分析经64层螺旋CT全腹平扫加多期动态增强扫描诊断的15例AMI.其中,肠系膜上动脉栓塞3例(完全栓塞1例,不完全栓塞2例),肠系膜上静脉栓塞12例.结果 15例AMI直接征象:动脉期显示肠系膜上动脉完全或部分充盈缺损,可诊断为肠系膜上动脉完全或部分栓塞(3例).静脉期显示肠系膜上静脉完全或部分充盈缺损,可诊断为肠系膜上静脉完全或部分栓塞(12例);间接征象“缆绳征”12例,肠系膜水肿10例,肠管壁增厚12例,肠管扩张、积液8例,肠壁强化减弱7例,其中2例可见节段性未强化区,腹水6例,肾前筋膜增厚4例,肠壁积气2例.平扫肠系膜上动脉或上静脉高密度征7例(静脉栓塞6例,动脉栓塞1例),肠系膜上静脉栓塞累及门静脉、脾静脉6例,其中4例在增强扫描时,可见肝脏异常低灌注区.结论 64层螺旋CT平扫加多期动态增强扫描对急性肠系膜血管栓塞的诊断及时准确,应作为临床怀疑肠系膜血管疾病首选检查方法,值得推广应用.%Objective To explore the diagnostic value of 64-slice spiral CT in acute mesenteric vascular embolism. Methods We retrospectively analyzed the images of 15 AMI by multiphase dynamic contrast-enhanced 64-slice spiral CT, 3 superior mesenteric artery embolization (1 completely embolization, 2 incompletely embolization), and 12 superior mesenteric vein embolization. Results The direct signs: superior mesenteric artery was full or partial filling defect in arterial phase, and superior mesenteric vein was full or partial filling defect in vein phase. Indirect sign: there were 12 cases of "stranding sign", 10 cases of mesenteric edema, 8 cases of bowel expansion and effusion, and 6 cases with ascites, 7 cases of high density for the blood vessel by CT plain scan (6 in superior mesenteric vein embolization, 1 in superior mesenteric

  17. Diagnosis of Acute Upper Gastrointestinal Perforation with Spiral CT%急性上消化道穿孔的螺旋CT诊断

    Institute of Scientific and Technical Information of China (English)

    林春; 张楚和; 吕怀志; 唐振国; 李亮平

    2014-01-01

    目的:探讨螺旋CT对急性上消化道穿孔的诊断价值。方法对49例经手术证实的急性上消化道穿孔患者的 CT 影像资料进行回顾性分析。结果49例患者中,十二指肠溃疡穿孔33例(67.35%);胃溃疡穿孔16例(32.65%),其中胃窦前壁穿孔9例(56.25%),胃小弯前壁穿孔7例(43.75%)。腹腔游离气体49例(100.00%),腹腔积液46例(93.88%),胃肠道壁不规则增厚或周围脂肪层模糊23例(46.94%)。结论通过螺旋CT诊断上消化道穿孔的患者,可以明确患者穿孔的病灶,能弥补X线平片的不足,为临床外科急腹症提供快速而可靠的诊断依据。%Objective To explore the diagnostic value of spiral CT in acute upper gastrointestinal perforation.Methods CT image data of 49 patients with acute upper gastrointestinal perforation confirmed by surgery were retrospectively analyzed. Results Among the 49 patients, duodenal ulcer perforation was observed in 33 (67.35%),gastric ulcer perforation in 16 (32.65%),intraperitoneal free gas in 49 (100.00%),ascites in 46 (93.88%),and irregular thickening of digestive wall and fuzzy fatty layer in 23(46.94%).Among the 16 patients with gastric ulcer perforation, perforation was located at anterior wall of the gastric antrum in 9 (56.25%) and at anterior wall of the lesser gastric curvature in 7 (43.75%). Conclusion Spiral CT can confirm perforated lesions, make up the deficiency of radiology and provide rapid and reliable diagnosis in patients with acute upper gastrointestinal perforation.

  18. Value of Spiral CT in Diagnosis of Causes of Acute Abdomen%螺旋CT在诊断急腹症病因中的价值

    Institute of Scientific and Technical Information of China (English)

    王波

    2016-01-01

    目的:探讨螺旋CT在诊断急腹症病因中的价值。方法整群选取回顾性分析2010年3月—2015年10月间共267例急腹症患者资料,226例行CT扫描,腹部平片检查191例,以临床治疗或手术结果作为诊断标准。结果在267例患者中,CT、腹部平片分别明确诊断急腹症病因213例、96例,正确诊断率分别为94.2%、50.2%,比较这两种方法差异有统计学意义(P<0.05)。结论螺旋CT可以作为诊断急腹症病因的首选检查方法,对临床治疗方法选择具有重要意义。%Objective To study the value of spiral CT in diagnosis of causes of acute abdomen. Methods The data of 267 cases of patients with acute abdomen from March 2010 to October 2015 were retrospectively analyzed, 226 cases underwent CT scanning, 191 cases underwent abdominal plain film examination, and the clinical treatment and operative results were used as the diagnostic standards. Results Of 267 cases of patients, the causes of acute abdomen of 213 cases were definite-ly diagnosed by CT, and the causes of acute abdomen of 96 cases were definitely diagnosed by abdominal plain film, the accurate diagnostic rates were respectively 94.2% and 50.2%, the difference had statistical significance by comparison(P<0.05). Conclusion Spiral CT can be used as the preferred examination method of diagnosis of causes of acute abdomen, which is of important significance to the choice of clinical treatment methods.

  19. Electromechanics of graphene spirals

    Directory of Open Access Journals (Sweden)

    Topi Korhonen

    2014-12-01

    Full Text Available Among the most fascinating nanostructure morphologies are spirals, hybrids of somewhat obscure topology and dimensionality with technologically attractive properties. Here, we investigate mechanical and electromechanical properties of graphene spirals upon elongation by using density-functional tight-binding, continuum elasticity theory, and classical force field molecular dynamics. It turns out that electronic properties are governed by interlayer interactions as opposed to strain effects. The structural behavior is governed by van der Waals interaction: in its absence spirals unfold with equidistant layer spacings, ripple formation at spiral perimeter, and steadily increasing axial force; in its presence, on the contrary, spirals unfold via smooth local peeling, complex geometries, and nearly constant axial force. These electromechanical trends ought to provide useful guidelines not only for additional theoretical investigations but also for forthcoming experiments on graphene spirals.

  20. Electromechanics of graphene spirals

    Energy Technology Data Exchange (ETDEWEB)

    Korhonen, Topi; Koskinen, Pekka, E-mail: pekka.koskinen@iki.fi [NanoScience Center, Department of Physics, University of Jyväskylä, 40014 Jyväskylä (Finland)

    2014-12-15

    Among the most fascinating nanostructure morphologies are spirals, hybrids of somewhat obscure topology and dimensionality with technologically attractive properties. Here, we investigate mechanical and electromechanical properties of graphene spirals upon elongation by using density-functional tight-binding, continuum elasticity theory, and classical force field molecular dynamics. It turns out that electronic properties are governed by interlayer interactions as opposed to strain effects. The structural behavior is governed by van der Waals interaction: in its absence spirals unfold with equidistant layer spacings, ripple formation at spiral perimeter, and steadily increasing axial force; in its presence, on the contrary, spirals unfold via smooth local peeling, complex geometries, and nearly constant axial force. These electromechanical trends ought to provide useful guidelines not only for additional theoretical investigations but also for forthcoming experiments on graphene spirals.

  1. Acute myocardial ischemia after aortic valve replacement: A comprehensive diagnostic evaluation using dynamic multislice spiral computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lembcke, Alexander [Department of Radiology, Charite-Universitaetsmedizin Berlin, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Berlin (Germany)]. E-mail: alexander.lembcke@gmx.de; Hein, Patrick A. [Department of Radiology, Charite-Universitaetsmedizin Berlin, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Berlin (Germany); Enzweiler, Christian N.H. [Department of Radiology, Charite-Universitaetsmedizin Berlin, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Berlin (Germany); Hoffmann, Udo [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Klessen, Christian [Department of Radiology, Charite-Universitaetsmedizin Berlin, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Berlin (Germany); Dohmen, Pascal M. [Department of Cardiovascular Surgery, Charite-Universitaetsmedizin Berlin, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Berlin (Germany)

    2006-03-15

    We describe the case of a 72-year-old man presenting with endocarditis and clinical signs of acute myocardial ischemia after biological aortic valve replacement. A comprehensive cardiac dynamic multislice spiral computed tomography demonstrated: (1) an endocarditic vegetation of the aortic valve; (2) a subvalvular leakage feeding a paravalvular pseudoaneurysm based on an aortic root abscess with subsequent compromise of the systolic blood flow in the left main coronary artery and the resulting myocardial perfusion deficit.

  2. Dynamics of the off axis intense beam propagation in a spiral inflector

    Science.gov (United States)

    Goswami, A.; Sing Babu, P.; Pandit, V. S.

    2017-01-01

    In this paper the dynamics of space charge dominated beam in a spiral inflector is discussed by developing equations of motion for centroid and beam envelope for the off axis beam propagation. Evolution of the beam centroid and beam envelope is studied as a function of the beam current for various input beam parameters. The transmission of beam through the inflector is also estimated as a function of the beam current for an on axis and off axis beam by tracking a large number of particles. Simulation studies show that shift of the centroid from the axis at the inflector entrance affects the centroid location at the exit of the inflector and causes reduction in the beam transmission. The centroid shift at the entrance in the horizontal plane (h plane) is more critical as it affects the centroid shift in the vertical plane (u plane) by a large amount near the inflector exit where the available aperture is small. The beam transmission is found to reduce with increase in the centroid shift as well as with the beam current.

  3. Estimation of absorbed dose of radiosensitive organs and effective sose in patients underwent abdominopelvic spiral CT scan using impact CT patient dosimetry

    Directory of Open Access Journals (Sweden)

    Ayoub Amirnia

    2017-05-01

    Full Text Available Background: Due to the presence of radiosensitive organs in the abdominopelvic region and increasing the number of requests for CT scan examinations, concerns about increasing radiation doses in patients has been greatly elevated. Therefore, the goal of this study was to determine the absorbed dose of radiosensitive organs and the effective dose in patients underwent abdominopelvic CT scan using ImPACT CT patient dosimetry Calculator (version 1.0.4, Imaging Performance Assessment on Computed Tomography, www.impactscan.org. Methods: This prospective cross-sectional study was conducted in Imam Reza Hospital from November to February 2015 February 2015 in the Imam Reza Hospital, in Urmia, Iran. The demographic and dosimetric information of 100 patients who underwent abdominopelvic CT scan in a 6-slice CT scanner were obtained through the data collection forms. The demographic data of the patients included age, weight, gender, and BMI. The dosimetric parameters included pitch value, CT dose volume index (CTDIvol, dose-length product (DLP, tube voltage, tube current, exposure time, collimation size, scan length, and scan time. To determine the absorbed dose of radiosensitive organs and also the effective dose in patients, ImPACT CT patient dosimetry calculator was used. Results: The results of this study demonstrated that the mean and standard deviation (SD of patients' effective dose in abdominopelvic CT scan was 4.927±0.164 mSv. The bladder in both genders had the greatest mean organ dose, which was 64.71±17.15 mGy for men and 77.56±18.48 mGy for women (P<0.001. Conclusion: The effective dose values of this examination are in the same range as previous studies, as well as International Commission on Radiological Protection (ICRP recommendations. However, the radiation dose from CT scan has the largest contribution to the medical imaging. According to the ALARA principle, it is recommended that the scan parameters, especially mAs, should be

  4. Coronary artery aneurysm and type-A aortic dissection demonstrated by retrospectively ECG-gated multislice spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Fallenberg, Eva Maria; Juergens, Kai Uwe; Fischbach, Roman [Department of Clinical Radiology, University Hospital Muenster (Germany); Wichter, Thomas [Department of Cardiology and Angiology, University Hospital Muenster (Germany); Scheld, Hans H. [Department of Thoracic and Cardiovascular Surgery, University Hospital Muenster (Germany)

    2002-01-01

    The case of a 40-year-old male patient with a coronary aneurysm of the proximal left descending artery (LAD) combined with circumferential type-A dissection of the ascending aorta is reported. Computed tomography angiography of the coronary arteries was performed using multislice spiral computed tomography (MSCT) with retrospective ECG gating. Anatomical relations of the LAD aneurysm as well as the origin of the left coronary artery from the false lumen of the dissection were well depicted for planning of the surgical intervention using this new noninvasive imaging modality. (orig.)

  5. 多层螺旋CT对颌骨放射性骨坏死的诊断价值%DIAGNOSTIC VALUE OF MULTI-SLICE SPIRAL CT FOR OSTERORADIONECROSIS OF JAW

    Institute of Scientific and Technical Information of China (English)

    林颖; 曹代荣; 游瑞雄; 江飞; 郑义浩

    2014-01-01

    Objective:To investigate the diagnostic value of multi-slice spiral CT for osteoradionecrosis of jaws (ORNJ). Methods:The CT ifndings of 27 cases ORNJ that were conifrmed by surgery and pathology were retrospectively analyzed. Results: The main CT ifndings of ORNJ were limited bone destruction and sequestration.Conclusions:Multi-slice spiral CT can clearly display location and appearance of lesions, sequestration, periosteal reaction and soft tissue mass formation. So multi-slice spiral CT has important value for diagnosis and differential diagnosis of ORNJ.%目的::探讨多层螺旋CT对颌骨放射性骨坏死(ORNJ)的诊断价值。方法:回顾性分析27例经手术、病理证实为ORNJ的CT表现。结果:ORNJ在多层螺旋CT上主要表现为局限性骨质破坏和死骨形成。结论:多层螺旋CT能清楚的显示ORNJ病灶的位置、形态、病灶内的死骨形成、有无骨膜反应及软组织肿块形成等,对ORNJ的诊断及鉴别诊断有重要的价值。

  6. Analysis of multi-slice spiral CT images in patients with esophageal cancer after surgery or radiotherapy%食管癌患者术后或放疗后多排螺旋 CT 影像分析

    Institute of Scientific and Technical Information of China (English)

    王锋

    2016-01-01

    Objective To explore the application value of multi-detector row spiral CT after the operation or radiotherapy in patients with esophageal carcinoma .Methods From August 2014 to March 2015,23 patients with esophageal cancer treated in our hospital received the examination of multi-detector row spiral CT after the operation or radiotherapy .Results After operation,CT re-sults showed that there were 4 cases with postoperative lymph node metastasis ,2 with lung metastasis and 3 with bone metastases ,2 with pericardial effusion ,1 with pleural effusion ,1 with esophageal mediastinum fistula and 1 with anastomotic recurrence .CT results also showed that after radiotherapy there were 12 with lymph node metastasis ,2 with liver metastasis ,3 with lung metastasis ,1 with radioac-tive pneumonia and 2 with pleural effusion .Conclusion The multi-slice helical CT can display a number of clinical manifestations such as complications ,recurrence and metastasis after operation and radiotherapy .It has an important clinical value .%目的:探讨多排螺旋CT在食管癌患者术后或放疗中的应用价值。方法2014年8月至2015年3月我院收治的23例食管癌患者,术后或放疗后均行多部位多排螺旋CT检查。结果 CT结果显示:术后患者出现淋巴结转移4例,肺部转移2例,骨转移3例,心包积液2例,胸腔积液1例,食管纵膈瘘1例,吻合口复发1例;而放疗后患者出现淋巴结转移12例,肝脏转移2例,肺部转移3例,放射性肺炎1例,胸腔积液2例。结论多排螺旋CT可显示出食管癌患者术后或放疗后的并发症、复发及转移等临床表现,具有重要的临床应用价值。

  7. 多排螺旋CT在胃肠道肿瘤及并发症的诊断价值%Multi-slice Spiral CT in the Diagnosis of Gastrointestinal Tumor and Complications

    Institute of Scientific and Technical Information of China (English)

    高云; 郑晓林; 尹昌媛

    2013-01-01

    目的 探讨多排螺旋CT在胃肠道肿瘤及并发症的诊断价值. 材料和方法 回顾性分析43例胃肠道肿瘤的多排螺旋CT表现,观察分析胃肠道肿瘤的直接CT征象及并发症征象.结果 CT可以直接发现胃肠道肿块的32例,肠管壁增厚11例,肠梗阻18例,肠套叠3例,肠扭转5例,消化道出血1例,肠系膜血管增粗26,肠系膜淋巴结肿大15例,肝脏转移7例,大网膜转移3例.结论 多排螺旋CT在消化道肿瘤的诊断方面有较高的临床实用价值,值得推广应用.%Objective To investigate diagnostic value of multi-slice spiral CT on the gastrointestinal tumor and complications.Materials and methods Multi-slice spiral CT performance of 43 patients with gastrointestinal tumors were retrospectively analyzed,to observe and analyze direct CT findings and complications CT findings of gastrointestinal tumors.Results 32 cases of the gastrointestinal masses could be directly found by multislice spiral CT; 11 cases of bowel wall thickening; 27 cases of intestinal obstruction; 3 cases of intussusception; 5 cases of volvulus; 1 case of gastrointestinal bleeding; 26 cases of mesenteric vascular thickening; 15 cases of mesenteric lymph nodes; 7 cases of liver metastases; 3 cases of omentum metastasis.Conclusion Multi-slice spiral CT in the diagnosis of gastrointestinal tumors had higher clinical value,should be widely applied.

  8. 颅内皮样囊肿螺旋CT诊断价值%Diagnosis of intracranial dermoid cyst with spiral CT

    Institute of Scientific and Technical Information of China (English)

    陈吉明; 宋海荣; 奚北龙; 柏国庆; 王双刚

    2015-01-01

    Objective To explore diagnosis value of spiral CT on intracranial dermoid cyst based on retrospective analysis.Methods 10 cases of intracranial dermoid cyst were enrolled in and confirmed by surgery and pathology.The retrospective analysis was based on the CT manifestations,causes,pathological and clinical features.Results Among the 10 cases,5 lesions were located in the posterior cranial fossa,3 in besides saddle,1 in up saddle and 1 in the temporal fossa.The morphology of nidus was round or round like with clear boundary.There was no edema around the nidus.Fat was found in 7 cases appeared hypodensity with insufficiency uniformity on CT,and the density was lower than that of cerebrospinal fluid with CT value ranged from-6 HU to 80 HU.There was a few calcification on the edge in 1 case.Hyperdensity irregular and lumpy hair-liked shadow was found in 2 hypodensity cases.1 lesion closed to the cranial plate was compressed thin and buckled.Conclusions Intracranial dermoid cyst has typical CT manifestations.It will be an accurate diagnosis based on clinical analysis and CT manifestations.%目的 探讨螺旋CT对颅内皮样囊肿的诊断价值.方法 收集10例经手术病理证实的颅内皮样囊肿患者资料,对其CT表现、病因、病理和临床特征进行回顾性分析.结果 病灶位于后颅窝5例,鞍旁3例,鞍上1例,颞窝1例;病灶形态呈圆形或类圆形,轮廓分界清晰,周围无水肿,7例呈欠均匀的低密度(密度低于脑脊液)脂肪影,CT值-6 ~ 80 HU,1例病灶边缘可见少量钙化,2例于低密度病灶内可见不规则团状毛发样高密度影,1例病灶临近颅板受压变薄、变形.结论 颅内皮样囊肿有典型的CT表现,结合临床综合分析可作出准确诊断.

  9. Photon counting spectroscopic CT with dynamic beam attenuator

    CERN Document Server

    Atak, Haluk

    2016-01-01

    Purpose: Photon counting (PC) computed tomography (CT) can provide material selective CT imaging at lowest patient dose but it suffers from suboptimal count rate. A dynamic beam attenuator (DBA) can help with count rate by modulating x-ray beam intensity such that the low attenuating areas of the patient receive lower exposure, and detector behind these areas is not overexposed. However, DBA may harden the beam and cause artifacts and errors. This work investigates positive and negative effects of using DBA in PCCT. Methods: A simple PCCT with single energy bin, spectroscopic PCCT with 2 and 5 energy bins, and conventional energy integrating CT with and without DBA were simulated and investigated using 120kVp tube voltage and 14mGy air dose. The DBAs were modeled as made from soft tissue (ST) equivalent material, iron (Fe), and holmium (Ho) K-edge material. A cylindrical CT phantom and chest phantom with iodine and CaCO3 contrast elements were used. Image artifacts and quantification errors in general and mat...

  10. Comprehensive Application of 64-slice Spiral CT Scan Techniques on Diagnosis Value of Nodular Goiter%64排CT的综合运用对诊断结节性甲状腺肿价值探讨

    Institute of Scientific and Technical Information of China (English)

    肖继伟; 王晓燕; 胡道予

    2014-01-01

    目的:探讨64排螺旋CT扫描技术的综合运用对结节性甲状腺肿的诊断及鉴别诊断方面的价值。方法:选择41例经过病理证实的结节性甲状腺肿,甲状腺肿瘤及其他结节性甲状腺疾病若干,全部行64排螺旋CT平扫及动态增强扫描加后续重建,观察病灶的大小、形态、密度、边缘、强化特点及有无侵犯和转移等,总结和归纳病灶的影像学表象及特征。结果:结节性甲状腺肿、甲状腺肿瘤及其他结节性甲状腺疾病在CT影像上的表现可能少部分有所重叠,但大多数趋于不同,且有一定规律可循。结论:基于64排CT扫描技术的综合运用可在很大程度上掌握结节性甲状腺肿及相似疾病的表象及特征,对结节性甲状腺肿诊断及鉴别诊断具有重要意义。%Objective:To discuss the comprehensive application of 64-slice spiral CT scan techniques on the diagnosis value of nodular goiter and its differential diagnostic value. Methods:41 cases of nodular goiter,thyroid tumors and other nodular thyroid diseases,which had been verified by pathology,were selected to conduct 64-slice spiral CT scan and dynamic contrast-enhanced scan plus follow-up reconstruction. With observing the size,shape,density,edge,enhancing char-acteristics of the lesion as well as its infringement and metastasis,imaging characteristics of the le-sion were concluded. Results:The imaging manifestations of nodular goiter,thyroid tumors and oth-er nodular thyroid diseases overlap only in small portion on CT,but mostly they are different. Con-clusion:The comprehensive application of 64-slice spiral CT scan techniques can considerably di-agnose the representations and characteristics of nodular goiter and similar diseases,which is signifi-cant to the diagnosis and differential diagnosis of nodular goiter.

  11. The spiral

    DEFF Research Database (Denmark)

    Bibace, Roger; Kharlamov, Nikita

    2013-01-01

    ’s work with Bernard Kaplan on symbol formation is a primer on this idea. This paper examines the idea of spirality and develops the notion of dynamic coexistence that can clarify the issue of directionality of development; that is, what is the general trajectory or ground plan that development assumes....... Directionality is discussed in terms of the organism-in-environment unfolding over time as the unit of developmental analysis. Thinking on this issue has proceeded from the nature–nurture debates, to recognition of the interaction of external and internal processes, to transactions between the organism...

  12. Improved dynamic CT angiography visualization by flow territory masking

    Directory of Open Access Journals (Sweden)

    Søren Christensen

    2015-01-01

    Full Text Available Backgound and Purpose: Computerized tomography (CT perfusion (or CTP source images from CT scanners with small detector widths can be used to create a dynamic CT angiogram (CTA similar to digital subtraction angiography (DSA. Because CTP studies use a single intravenous injection, all arterial territories enhance simultaneously, and individual arterial territories [i.e., anterior cerebral artery (ACA, middle cerebral artery (MCA, and posterior cerebral artery (PCA] cannot be delineated. This limits the ability to assess collateral flow patterns on dynamic CTAs. The aim of this study was to devise and test a postprocessing method to selectively color-label the major arterial territories on dynamic CTA. Materials and Methods: We identified 22 acute-stroke patients who underwent CTP on a 320-slice CT scanner within 6 h from symptom onset. For each case, two investigators independently generated an arterial territory map from CTP bolus arrival maps using a semiautomated method. The volumes of the arterial territories were calculated for each map and the average relative difference between these volumes was calculated for each case as a measure of interrater agreement. Arterial territory maps were superimposed on the dynamic CTA to create a vessel-selective dynamic CTA with color-coding of the main arterial territories. Two experts rated the arterial territory maps and the color-coded CTAs for consistency with expected arterial territories on a 3-point scale (excellent, moderate, poor. Results: Arterial territory maps were generated for all 22 patients. The median difference in arterial territory volumes between investigators was 2.2% [interquartile range (IQR 0.6-8.5%]. Based on expert review, the arterial territory maps and the vessel-selective dynamic CTAs showed excellent consistency with the expected arterial territories in 18 of 22 patients, moderate consistency in 2 patients, and poor consistency in another 2 patients. Conclusion: Using a

  13. Dynamics and Selection of Giant Spirals in Rayleigh-Benard Convection

    CERN Document Server

    Plapp, B B; Bodenschatz, E; Pesch, W; Plapp, Brendan B.; Egolf, David A.; Bodenschatz, Eberhard; Pesch, Werner

    1998-01-01

    For Rayleigh-Benard convection of a fluid with Prandtl number \\sigma \\approx 1, we report experimental and theoretical results on a pattern selection mechanism for cell-filling, giant, rotating spirals. We show that the pattern selection in a certain limit can be explained quantitatively by a phase-diffusion mechanism. This mechanism for pattern selection is very different from that for spirals in excitable media.

  14. 急性肺挫伤的螺旋CT诊断及临床价值%Acute pulmonary contusion of spiral CT diagnosis and its clinical value

    Institute of Scientific and Technical Information of China (English)

    范晓萌; 陈琪宝; 刘海俊; 邹玉红; 张东升

    2012-01-01

    目的 探讨急性肺挫伤的螺旋CT诊断及其临床应用价值.方法 回顾性分析38例急性肺挫伤的CT表现及临床资料.结果 实质型28例,表现为单侧或双侧肺实质内沿支气管走行分布的斑片状边缘模糊密度增高影.间质型5例,表现为肺纹理不均匀性增粗、边缘模糊.磨玻璃型5例,表现为一侧或双侧局部肺野透亮度减低、其内见正常走行肺纹理的磨玻璃样影.本组中合并肺撕裂伤伴肺内血肿3例.伴其他部位不同程度损伤16例.结论 胸部螺旋CT平扫对肺挫伤诊断准确率高,能实时明确创伤的部位、性质、程度和范围,并能对临床治疗、转归和预后判断起到很好的指导作用,应作为急诊危重及复合伤患者首选的影像检查方法.%Objective To investigate acute pulmonary contusion of spiral CT diagnosis and clinical application value. Methods a retrospective analysis of 38 cases of acute pulmonary contusion CT findings and clinical data. Results 28 cases with solid type, showed unilateral or bilateral lung parenchyma along the bronchial walking distribution of patch)' fuzzy edge density increased. Interstitial type in 5 cases , for the performance of lung texture inhomogeneity thickening, edge blur. Ground glass type in 5 cases, showed unilateral or bilateral partial lung field penetrating brightness, which reduce the normal running of lung texture of ground glass opacity. The group combined with pulmonary laceration with intrapulmonary hematoma in 3 cases. With other parts of the different degree of injury in 16 cases. Conclusion thoracic spiral CT scan in pulmonary contusion with high diagnostic accuracy, real -time definitive trauma site, nature, extent and range, and to the clinical treatment, outcome and prognostic play a very good role in guiding, should serve as a critical and complex trauma patients preferred imaging method.

  15. Application of imaging postprocessing of spiral CT in the staging of lung cancer%螺旋CT后处理技术在肺癌新分期中的临床价值

    Institute of Scientific and Technical Information of China (English)

    Zhiming Xiang; Fang Huang; Cuimei Liang; Xiangdong Xu; Lilian Tan

    2008-01-01

    Objective:To evaluate the role of spiral CT imaging postprocessing techniques in preoperative TNM staging of lung cancer.Methods:106 patients with pathologically confirmed lung cancer received spiral CT examinations with a new revised TNM staging method of lung cancer which was taken as criterion of diagnosis.The images were reconstructed by using different postprecessing techniques such as MPR,MIP,SSD,VR,and their TNM staging capabilities were assessed by using postprocessing imaging and the results with axial CT images were compared.Results:In T staging,the accurate rates of axial CT images in T1-T4 staging were 77.3%,60.6%,60.7%,and 60.3% respectively; for postprocessing images,the accurate rates were 86.4%,90.9%,89.3%,and 87.0% respectively.In N staging,the accurate rates of axial CT images were 84.6%,68.1%,63.6%,and 64.2% in NO-N3 staging,respectively; but they were 92.3%,90.9%,90.9%,and 85.7% in postprocessing images,respectively.The postprocessing images were superior to axial CT images in T1-T3 and N1-N3 staging of lung cancer but there were no significant differences in T1 and NO staging.For metastasis,the postprocessing images may be helpful for the TNM staging of lung cancer.Conclusion:The postprocessing techniques of the spiral CT could improve the accurate rates of TNM staging of lung cancer,and represent a useful complement to the axial CT.

  16. Screenings of lung cancer with low dose spiral CT: results of a three year pilot study and design of the randomised controlled trial Italung-CT; Screening della neoplasia polmonare con TC spirale a bassa dose: risultati di uno studio pilota triennale e disegno dello studio clinico randomizzato Italung-CT

    Energy Technology Data Exchange (ETDEWEB)

    Picozzi, Giulia [Firenze Univ., Firenze (Italy). Radiodiagnostica I-Dipartimento di Fisiopatologia Clinica; Paci, Enrico [Azienda Ospedaliera Universitaria di Careggi, Firenze (Italy). Unita' di Epidemiologia Clinica e Descrittiva Centro per lo Studio e la Prevenzione Oncologica; Lopes Pegna, Andrea [Azienda Ospedaliera Universitaria di Careggi, Firenze (Italy). U.O. Pneumologia] [and others

    2005-02-01

    Purpose: To report the results of a three-year observational pilot study of lung cancer screening with low dose computed tomography (CT) and to present the study design of a randomised clinical trial named as Italung CT. Materials and methods: Sixty (47 males and 13 females, mean age 64{+-}4.5 years) heavy smokers (at least 20 packs-year) underwent three low-dose spiral CT screening tests one year apart on a single slice or multislice CT scanner. Indeterminate nodules were managed according to the recommendations of the Early Lung Cancer Action Project. Results: Indeterminate nodules were observed in 33 (55%) of the subjects (60% at the baseline screening test, 24% at the first annual test and 16% at the second annual test). The size of the largest indeterminate nodule was <5mm in diameter in 20 subjects. 10 of whom showed the nodule at the baseline test. Forty-five subjects (75%) completed the first annual test and 42 (70%) the second annual test. One (1.6%) prevalent lung cancer (adenosquamous carcinoma) and one (2.2%) incident lung cancer (small cell cancer at the first annual examination) were observed, as well as pulmonary localisation of Hodgkin's lymphoma (at the second annual test). In addition, one subject underwent lung surgery for a chondromatous hamartoma. Conclusions: The results of the pilot study are substantially in line with those of other observational studies of greater sample size. This justifies optimism about the reliability of the results in the screened arm of the Italung Ct trial which hast just began. [Italian] Scopo: Riportare i risultati di uno studio pilota osservazionale di screening della neoplasia polmonare con TC a bassa dose della durata di tre anni e presentare il disegno dello studio clinico randomizzato Italung-CT. Materiale e metodi: Sessanta (47 uomini e 13 donne, eta' media 64{+-}4,5 anni) forti fumatori (almeno 20 pacchetti/anno) sono stati sottoposti ad un esame basale e a due controlli annuali con TC single o

  17. Evaluation of periventricular radiolucency in hydrocephalus by dynamic CT studies

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Hideki; Bandou, Kuniaki; Miyaoka, Makoto (Fujisawa City Hospital, Kanagawa (Japan))

    1994-06-01

    The association of periventricular radiolucency (PVL) in normal pressure hydrocephalus (NPH) on CT scan is a common finding. However, it is difficult to differentiate NPH from atrophy or infarctions in which shunt surgery does not reverse these conditions. To distinguish NPH from these, we examined PVL by means of dynamic CT (DCT) studies. We investigated 12 elderly patients presenting with gait disturbance, urinary incontinence and mental dysfunction who had both enlarged lateral ventricles and PVL. All patients had laboratory investigations, including radioisotope and CT cisternography and Xenon CBF studies. Nine patients were shunted because of abnormal CSF dynamics. Varying degrees of clinical improvement after surgery were observed in 6 cases. A difference of arrival time (AT) between PVL and thalamus obtained from time-density-curve was calculated in each patient. The AT difference was 6.2[+-]1.5 sec. in the shunt-effective group, and 1.4[+-]1.3 sec. in both, the shunt in effective and ineligible group, this was highly significant (p<0.01). We also measured peak time (PT) in PVL, of the thalamus and anterior cerebral artery, but no significant correlation was obtained. An AT difference between PVL and thalamus obtained from DCT studies is a clinically useful diagnostic tool for the evaluation of NPH. (author).

  18. Dynamic cone beam CT angiography of carotid and cerebral arteries using canine model

    OpenAIRE

    Cai, Weixing; zhao,binghui; Conover, David; Liu, Jiangkun; Ning, Ruola

    2012-01-01

    Purpose: This research is designed to develop and evaluate a flat-panel detector-based dynamic cone beam CT system for dynamic angiography imaging, which is able to provide both dynamic functional information and dynamic anatomic information from one multirevolution cone beam CT scan.

  19. Dynamic CT study of normal-pressure hydrocephalus

    Energy Technology Data Exchange (ETDEWEB)

    Tamaki, Norihiko; Kojima, Noriaki; Shirakuni, Takayuki; Matsumoto, Satoshi

    1984-08-01

    A dynamic CT study was performed in 14 patients with presumed normal-pressure hydrocephalus, of which diagnosis had been made by clinical symptomatology, CT findings, the results of the continuous monitoring of intracranial pressure, and CT cisternographic findings. It is demonstrated by serial CT scans that the cerebral arteries and arterioles were initially filled with contrast media, which were followed by the symmetrical and homogeneous staining of the cortical gray matter and basal ganglia, the diencephalia, and then the white matter. The venous system was stained in the late phase. The contrast media was finally cleared out from the intracranial space. Thus, the staining of the cerebral vessels and brain parenchym showed a uniform pattern in all cases. Functional CT images revealed that the patients with normal-pressure hydrocephalus who responded well to the shunt procedure had areas of prolonged mean circulation time scattered diffusely not only in the paraventricular structures, but also in the cortical gray matter of all the cerebral hemispheres. Following the shunt procedure, the hemodynamic conditions improved in almost all the areas mentioned above, but especially in the frontal and temporal gray matters and the paraventricular structures. In the patients who did not benefit from the shunt operation, however, there was no special abnormality of hemodynamic distribution. The analysis of the mean circulation time in the region of interest demonstrated that a significant improvement in cerebral hemodynamics was noted in the regions of the frontal and temporal gray matters, the periventricular white matter, and the caudate nucleus in patients who benefitted from the shunt operation. In patients who did not improve after the ventriculo-peritoneal shunt, however, there was no statistically significant difference between pre- and post-shunt mean circulation times. (J.P.N.).

  20. Faster dynamic imaging of speech with field inhomogeneity corrected spiral fast low angle shot (FLASH) at 3 T.

    Science.gov (United States)

    Sutton, Bradley P; Conway, Charles A; Bae, Youkyung; Seethamraju, Ravi; Kuehn, David P

    2010-11-01

    To evaluate the impact of magnetic field inhomogeneity correction on achievable imaging speeds for magnetic resonance imaging (MRI) of articulating oropharyngeal structures during speech and to determine if sufficient acquisition speed is available for visualizing speech structures with real-time MRI. We designed a spiral fast low angle shot (FLASH) sequence that combines several acquisition techniques with an advanced image reconstruction approach that includes magnetic field inhomogeneity correction. A simulation study was performed to examine the interaction between imaging speed, image quality, number of spiral shots, and field inhomogeneity correction. Six volunteer subjects were scanned to demonstrate adequate visualization of articulating structures during simple speech samples. The simulation study confirmed that magnetic field inhomogeneity correction improves the available tradeoff between image quality and speed. Our optimized sequence co-acquires magnetic field maps for image correction and achieves a dynamic imaging rate of 21.4 frames per second, significantly faster than previous studies. Improved visualization of anatomical structures, such as the soft palate, was also seen from the field-corrected reconstructions in data acquired on volunteer subjects producing simple speech samples. Adequate temporal resolution of articulating oropharyngeal structures during speech can be obtained by combining outer volume suppression, multishot spiral imaging, and magnetic field corrected image reconstruction. Correcting for the large, dynamic magnetic field variation in the oropharyngeal cavity improves image quality and allows for higher temporal resolution. © 2010 Wiley-Liss, Inc.

  1. Light-driven dynamic Archimedes spirals and periodic oscillatory patterns of topological solitons in anisotropic soft matter.

    Science.gov (United States)

    Martinez, Angel; Smalyukh, Ivan I

    2015-02-23

    Oscillatory and excitable systems commonly exhibit formation of dynamic non-equilibrium patterns. For example, rotating spiral patterns are observed in biological, chemical, and physical systems ranging from organization of slime mold cells to Belousov-Zhabotinsky reactions, and to crystal growth from nuclei with screw dislocations. Here we describe spontaneous formation of spiral waves and a large variety of other dynamic patterns in anisotropic soft matter driven by low-intensity light. The unstructured ambient or microscope light illumination of thin liquid crystal films in contact with a self-assembled azobenzene monolayer causes spontaneous formation, rich spatial organization, and dynamics of twisted domains and topological solitons accompanied by the dynamic patterning of azobenzene group orientations within the monolayer. Linearly polarized incident light interacts with the twisted liquid crystalline domains, mimicking their dynamics and yielding patterns in the polarization state of transmitted light, which can be transformed to similar dynamic patterns in its intensity and interference color. This shows that the delicate light-soft-matter interaction can yield complex self-patterning of both. We uncover underpinning physical mechanisms and discuss potential uses.

  2. 螺旋CT对寰枢椎损伤的诊断价值%Diagnostic Value of Spiral CT for Atlantoaxial Injury

    Institute of Scientific and Technical Information of China (English)

    沈明华; 叶进湖

    2012-01-01

    目的 探讨X线平片和螺旋CT及其后图像处理技术在寰枢椎损伤中的应用价值.方法 回顾性分析37例患者通过X线平片和多层螺旋CT证实寰枢关节脱位,齿状突骨拆,寰枢侧块及椎弓骨折的一般资料.利用三维重建、二维重建、容积再现和表面遮盖法后处理技术显示骨折、脱位,并进行比较.结果 37例患者中X线平片诊断正确25例,可疑和误诊2例.螺旋CT均明确诊断,其中C1爆裂性骨折7例,其中2例合并C1、C2脱位失稳.C2齿状突骨折17例,其中X线平片漏诊2例.C2椎弓骨折(Hangman 骨折)9例.单纯C1、C2椎间失稳2例,其中X线平片漏诊1例.枢椎椎体骨折,本组中2例为椎体纵行骨折,骨折无明显移位.在37例寰枢椎骨折病例中,螺旋CT全部正确,X线平片诊断正确25例,正确率67.5%,其中9例未能作出诊断,3例将寰枢椎骨折误诊为关节脱位.结论 应用X线平片诊断寰枢椎损伤有很大局限性,易发生漏检.螺旋CT轴位和多种重建技术各具特色,结合使用可提高寰枢椎损伤的诊断价值.%Objective To study the application value of X-ray radiography and spiral CT and digital image processing technology in the vertebral injury between atlas. Methods A retrospective analysis of 37 cases of atlantoaxial dislocation,odontoid bone removed, atlantoaxial lateral mass and pedicle fracture confirmed by X-ray and spiral CT was done. Three-dimensional reconstruction, two-dimensional reconstruction, volume rendering and surface shaded display post-processing techniques were used to display the fractures,dislocations,and comparison was done. Results Among 37 patients,X-ray diagnosis was correct in 25 cases,2 cases were suspicious and misdiagnosed. All were clearly diagnosed by spiral CT,of which the column C1 burst fracture in 7 cases,including 2 patients with C1, C2 dislocation instability. C2 dens fractures in 17 patients, including X-ray missed in 2 cases. C2 pedicle fracture( Hangman

  3. Diagnostic value of multi-slice spiral CT in occult fractures of proximal tibia%多层螺旋CT对胫骨近端隐匿性骨折的诊断价值

    Institute of Scientific and Technical Information of China (English)

    周俊; 陈庆; 许文渊; 姚雯雯

    2012-01-01

    目的 探讨多层螺旋CT对胫骨近端隐匿性骨折的诊断价值.方法 回顾性分析23例数字放射摄影诊断可疑胫骨近端骨折病例的16层螺旋CT的横轴位、多平面重建、容积再现、最大密度投影,观察多层螺旋CT对胫骨近端隐匿性骨折的诊断率.结果 所选病例数字放射摄影均未显示明确骨折线,16层螺旋CT诊断胫骨近端骨折17例,其中胫骨平台骨折13例、胫骨髁间棘骨折4例;排除骨折6例,阳性率达73.9%.结论 多层螺旋CT对临床怀疑胫骨近端骨折而数字放射摄影不能确诊为骨折的病例能准确地作出诊断,对治疗方案的选择及预后的估计有重要价值.%Objective To discuss the diagnostic value of multi-slice spiral CT for the occult fracture of proximal tibia. Methods 23 patients with suspected fracture of proximal tibia by digital radiography were studied, and their images of transverse, multiplanar reconstruction, and volume rendering and maximum intensity projection of 16-slice spiral CT were analyzed. The diagnostic rate for occult fracture of proximal tibia with multi-slice spiral CT was observed. Results Digital radiography showed no definite fracture signs in all patients. 16-slice spiral CT showed fractures in 17 cases, including fractures of tibia plateau in 13 cases and tibia eminence in 4 cases. The other 6 patients showed negative on 16-slice spiral CT images. Conclusion Multi-slice spiral CT can be used to diagnose definitely occult fractures of proximal tibia and plays an important role in selecting therapy project and evaluating prognosis of occult fractures.

  4. 16层螺旋CT多平面重组诊断卵巢癌的价值研究%A study on the 16-slice spiral CT of multi-planar reformation in the diagnosis of ovarian carcinoma

    Institute of Scientific and Technical Information of China (English)

    吴晓莉; 先世伟; 刘鲁

    2012-01-01

    目的 探讨16层螺旋CT薄层增强扫描后多平面重组(MPR)对卵巢癌的诊断价值.方法 回顾性分析65例临床怀疑卵巢癌患者的CT资料(薄层增强扫描),所有病例均经手术病理检查证实.结果 16层螺旋CT薄层增强扫描检查提示卵巢癌65例,经手术病理检查或穿刺活检证实53例,即真阳性53例,假阳性12例,卵巢癌的16层螺旋CT诊断准确性为81.5%.结论 16层螺旋CT薄层增强扫描后MPR对卵巢癌具有重要诊断价值.%Objective To investigate the diagnostic value of the 16-slice spiral CT with thin slices and enhancement scan after multi-planar reformation(MPR) in detection of ovarian carcinoma. Methods The CT data (thin slices and enhancement scan) of 65 cases suspected ovarian carcinoma were studied, all cases were confirmed by operation and pathology. Results Fifty-three of Six-five patients were diagnosed as ovarian carcinoma using the 16-slice spiral CT,in which there were Fifty-three patients with ovarian carcinoma proved by operation and pathology, Fifty-three patients with true-positive; twelve patients with false-positive; the diagnostic accuracy rate of the 16-slice spiral CT with thin slices and enhancement scan was 81. 5%. Conclusion The 16-slice spiral CT with thin slices and enhancement scan after multi-planar reformation(MPR) is valuable in diagnosis of ovarian carcinoma.

  5. Clinical application value of 64 slice spiral CT in the diagnosis of upper gastrointestinal bleeding%64层螺旋CT在上消化道出血诊断中的临床应用价值分析

    Institute of Scientific and Technical Information of China (English)

    王振栋; 马淑华; 黎叶芳; 袁珠

    2016-01-01

    Objective:To explore the clinical application value of 64 slice spiral CT in the diagnosis of upper gastrointestinal bleeding.Methods:70 patients with upper gastrointestinal bleeding were selected.They were given x-ray barium meal examination and 64 slice spiral CT examination.We compared the test results of two kinds.Results:The detection rate of 64 slice spiral CT was 100%,and the detection rate of X-ray was 95.71%(P<0.05).The consistent rate of CT diagnosis of bleeding was 100%,which was significantly better than 85.71% of X-ray(P<0.05).Conclusion:The clinical application value of 64 slice spiral CT in the diagnosis of upper gastrointestinal bleeding was significant.%目的:探讨64层螺旋CT在上消化道出血诊断中的临床应用价值。方法:收治上消化道出血患者70例,均接受 X 线钡餐检查和64层螺旋 CT检查,比较两种检查结果。结果:64层螺旋 CT检出率100%,X 线检出率95.71%(P<0.05)。CT诊断出血原因相符率100%,显著优于X线的85.71%(P<0.05)。结论:64层螺旋CT在上消化道出血诊断中的临床应用价值显著。

  6. 多层螺旋 CT在颌骨囊肿累及牙诊断中的作用研究%Diagnostic value of multislice spiral CT on cyst of jaw implicate tooth

    Institute of Scientific and Technical Information of China (English)

    钱江松; 刘小明; 区俊兴; 黎玉冰; 孟凡霞

    2015-01-01

    目的:探讨多层螺旋CT在颌骨囊肿累及牙诊断中的作用。方法对2010年3月至2013年5月东莞市厚街医院颌面外科收治的43例颌骨囊肿病例,术前行多层螺旋CT检查,了解可疑牙齿牙根与颌骨囊肿的关系并与术中情况对照。结果多层螺旋 CT 诊断颌骨囊肿可疑受累牙的准确率为97.01%。结论多层螺旋CT在颌骨囊肿受累牙诊断中有参考价值。%Objective To investigate the diagnostic value of multislice spiral CT on tooth involved in jaws cyst.Methods The study including 43 patients with jaws cyst, they received therapy at the oral maxillofacial surgery department in Houjie hospital of Dongguan city during March 2010 and May 2013.All of them took multislice spiral CT examination before operation to understand the relationship between the root of suspicious tooth and jaw cyst , and compared with intra -operative situation .Results The accuracy of multislice spiral CT in the diagnosis of suspected involvement of tooth in jaw cyst was 97.01%.Conclusions Multislice spiral CT has a reference value in the diagnosis of tooth involved in the jaws cyst .

  7. Imaging diagnosis of solitary pulmonary nodules on an open low-field MRI system - comparison of two MR sequences with spiral CT; Bildgebende Diagnostik solitaerer Lungenrundherde am offenen Niederfeld-MRT. Ein Vergleich zweier MR-Sequenzen mit der Spiral-CT

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, J.F.; Vollmar, J.; Seemann, M.D.; Mehnert, F.; Claussen, C.D. [Abt. fuer Radiologische Diagnostik, Universitaetsklinikum Tuebingen (Germany); Schick, F. [Abt. fuer Radiologische Diagnostik, Sektion Experimentelle Radiologie, Universitaetsklinikum Tuebingen (Germany); Vonthein, R. [Inst. fuer Medizinische Biometrie, Universitaetsklinikum Tuebingen (Germany); Aebert, H. [Abt. fuer Herz-, Thorax- und Gefaesschirurgie, Universitaetsklinikum Tuebingen (Germany)

    2002-09-01

    Objective: To evaluate and compare two fast gradient-echo sequences (GRE) concerning the visualization of solitary pulmonary nodules with an open low-field MRI system in comparison to computed tomography. Materials and Methods: Fourteen patients with solitary pulmonary nodules detected by spiral CT ranging in size from 6 mm to 42 mm (mean 20 mm) underwent MRI on an open 0.2 T scanner using a spoiled 2D GRE (2D FLASH; TR/ TE/Flip = 100 ms/7.5 ms/30 ) and a totally refocused 2D steady-state GRE (True-FISP; TR/TE/FA = 7.3 ms/3.5 ms/80 ). The image quality concerning artifacts (by flow, breathing and susceptibility) and the morphologic characteristics of the nodules were scored and compared with CT by two independent radiologists. The diameters of the nodules measured by MRI were compared with CT measurements. The sequences were also evaluated with regard to the signal-to-noise ratio (SNR) of the lesion. Results: All lesions were detected with the 2D FLASH sequence. True-FISP failed to find a granuloma with a size of 6 mm. The 2D FLASH was rated significantly superior to true FISP concerning image quality artifacts by susceptibility as well as concerning to CT the presentation of nodule characteristics. In MR images, the size of lesions was significantly smaller than in CT images for both sequences: for 2D FLASH the mean difference was 0.9 mm and for true FISP 2.6 mm. The SNR of the nodules was significantly higher for the 2D FLASH than for the true FISP. Conclusion: In low field MRI, the 2D FLASH sequence is superior to the 2D true FISP sequence in imaging of pulmonary nodules. With the 2D FLASH sequence nodules of 6 mm or larger in size can be visualized. (orig.) [German] Zielsetzung: Feststellen der Wertigkeit und Vergleich von zwei schnellen Gradientenechosequenzen (GRE) in der Darstellung solitaerer Lungenrundherde im Vergleich zur Computertomographie am offenen Niederfeld-MR-Tomographen. Material und Methode: 14 Patienten mit einem in der Spiral-CT detektierten

  8. Utility of bolus dynamic CT for the detection of hypervascular malignant hepatic tumors. Mainly referring to the comparison with delayed phase contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiromichi; Abe, Kimihiko [Tokyo Medical Coll. (Japan); Freeny, P.C.

    1996-03-01

    In order to analyze the usefulness of dynamic contrast-enhanced CT, 84 patients who had hepatocellular carcinoma or suspected hypervascular metastases were studied with conventional incremental dynamic CT (CID-CT) or double helical CT (DH-CT). Delayed phase contrast-enhanced CT studies were consecutively performed in all patients. Thirty-six of 84 patients had malignant hepatic neoplasms; six had hepatocellular carcinoma and 30 had metastatic tumors. At first, the detectability of hepatic lesions was evaluated with bolus dynamic CT and delayed phase CT. Dynamic CT has detected more lesions than delayed CT. Some hepatic lesions described as isodensity were missed on CID-CT. Therefore, delayed phase CT cannot be eliminated when CID-CT is performed. Secondly, hepatic lesion detectability with CID-CT was compared with that of DH-CT. DH-CT did not miss the hepatic lesions picked up by delayed phase CT and was expected to provide excellent detectability of hypervascular hepatic neoplasms. In addition, first helical CT showed most hepatic lesions as areas of obvious hyperdensity, while CID-CT did not show their correct vascularities. So-called hypervascular hepatic tumors, however, were not always hypervascular and were demonstrated as areas of iso-hypodensity even on initial helical scanning. Second helical CT was useful to detect these so-called hypervascular, but actually hypovascular lesions. In conclusion, dynamic CT was helpful in detecting hypervascular hepatic malignant neoplasms, and DH-CT was more accurate than-CID-CT for the detection of hepatic lesions and the evaluation of vascular lesion. (author).

  9. Multidetector spiral CT arthrography of the shoulder. Clinical applications and limits, with MR arthrography and arthroscopic correlations.

    Science.gov (United States)

    Lecouvet, Frédéric E; Simoni, Paolo; Koutaïssoff, Sophie; Vande Berg, Bruno C; Malghem, Jacques; Dubuc, Jean-Emile

    2008-10-01

    Although MR imaging and MR arthrography are the first choice modalities for shoulder imaging, CT arthrography (CTA) may be used successfully to address many clinical questions. The advent of submillimeter multiple detector CT technology and subsequent excellent three-plane resolution has considerably increased the quality of CTA examinations and has propelled this technique to the forefront in a growing number of indications. The combined use of iodinated contrast material for fluoroscopic confirmation of the articular position of the needle before injection of gadolinium chelates for MR arthrography offers the unique opportunity to compare CTA and MRA findings in carefully selected cases. This paper illustrates capabilities and limits of CTA for the study of rotator cuff tears, shoulder instability, cartilage lesions, anatomical variants and abnormalities of the glenoid labrum, with correlations to MR arthrography and surgical findings.

  10. Evaluation of Distal Femoral Rotational Alignment with Spiral CT Scan before Total Knee Arthroplasty (A Study in Iranian Population

    Directory of Open Access Journals (Sweden)

    Mahmoud Jabalameli

    2016-04-01

    Full Text Available Background: Evaluating the landmarks for rotation of the distal femur is a challenge for orthopedic surgeons. Although the posterior femoral condyle axis is a good landmark for surgeons, the surgical transepicondylar axis may be a better option with the help of preoperative CT scanning. The purpose of this study was to ascertain relationships among the axes’ guiding distal femur rotational alignment in preoperative CT scans of Iranian patients who were candidates for total knee arthroplasty and the effects of age, gender, and knee alignment on these relationships. Methods: One hundred and eight cases who were admitted to two university hospitals for total knee arthroplasty were included in this study. The rotation of the distal femur was evaluated using single axial CT images through the femoral epicondyle. Four lines were drawn digitally in this view: anatomical and surgical transepicondylar axes, posterior condylar axis and the Whiteside anteroposterior line. The alignment of the extremity was evaluated in the standing alignment view. Then the angles were measured along these lines and their relationship was evaluated. Results: The mean angle between the anatomical transepicondylar axis and posterior condylar axis and between the surgical transepicondylar axis and posterior condylar axis were 5.9 ± 1.6 degrees and 1.6±1.7 degrees respectively. The mean angle between the Whiteside’s anteroposterior line and the line perpendicular to the posterior condylar axis was 3.7±2.1 degrees. Significant differences existed between the two genders in these relationships. No significant correlation between the age of patients and angles of the distal femur was detected. The anatomical surgical transepicondylar axis was in 4.3 degrees external rotation in relation to the surgical transepicondylar axis. Conclusion: Preoperative CT scanning can help accurately determine rotational landmarks of the distal femur. If one of the reference axes cannot be

  11. Analysis of Double Spiral CT in Diagnosis of Central Lung Cancer%双排螺旋CT对中央型肺癌的诊断作用分析

    Institute of Scientific and Technical Information of China (English)

    汪红星

    2015-01-01

    目的:探究双排螺旋 CT 对中央型肺癌的诊断作用。方法对我院收治的84例中央型肺癌患者行双排螺旋 CT 扫描,观察其扫描结果及分期。结果双排螺旋 CT 征象显示管壁增厚、腔内外肿块、管腔改变、阻塞性改变、转移性改变分别占71.4%、53.6%、63.1%、67.9%、15.5%,CT 征象与手术病理诊断比较差异无统计学意义,P >0.05。CT 临床 T 分期总符合率为92.9%。结论双排螺旋 CT 诊断中央型肺癌的临床诊断率和临床分期准确率较高,可为手术治疗提供有价值的诊断信息。%Objective To explore the diagnostic effect of double spiral CT in central lung cancer. Methods Selected 84 cases of patients with central lung cancer with spiral CT scanning in our hospital as the research objects,and observed the results of the scanning stage. Results Double row helical CT display tube wal thickening,cavity tumors inside and outside,the lumen and obstructive changes,transfer changes accounted for 71.4%,53.6%,63.1%, 67.9%,15.5% respectively,the difference between the CT signs and pathologic diagnosis without statistical significance,P > 0.05. The total compliance rate of CT clinical T staging was 92.9%. Conclusion Double row spiral CT has higher clinical staging accuracy rate in the diagnosis of central type lung cancer,which can provide valuable diagnostic information for surgical treatment.

  12. Dynamic Contrast-Enhanced CT in Patients with Pancreatic Cancer

    Directory of Open Access Journals (Sweden)

    Rie Ø. Eriksen

    2016-09-01

    Full Text Available The aim of this systematic review is to provide an overview of the use of Dynamic Contrast-enhanced Computed Tomography (DCE-CT in patients with pancreatic cancer. This study was composed according to the PRISMA guidelines 2009. The literature search was conducted in PubMed, Cochrane Library, EMBASE, and Web of Science databases to identify all relevant publications. The QUADAS-2 tool was implemented to assess the risk of bias and applicability concerns of each included study. The initial literature search yielded 483 publications. Thirteen articles were included. Articles were categorized into three groups: nine articles concerning primary diagnosis or staging, one article about tumor response to treatment, and three articles regarding scan techniques. In exocrine pancreatic tumors, measurements of blood flow in eight studies and blood volume in seven studies were significantly lower in tumor tissue, compared with measurements in pancreatic tissue outside of tumor, or normal pancreatic tissue in control groups of healthy volunteers. The studies were heterogeneous in the number of patients enrolled and scan protocols. Perfusion parameters measured and analyzed by DCE-CT might be useful in the investigation of characteristic vascular patterns of exocrine pancreatic tumors. Further clinical studies are desired for investigating the potential of DCE-CT in pancreatic tumors.

  13. Cirrhosis:CT grading with 64-slice spiral CT perfusion imaging%肝硬化CT分级的64层螺旋CT灌注成像分析

    Institute of Scientific and Technical Information of China (English)

    陈勇; 郝凯; 尚英杰; 石俊英; 杨文魁

    2012-01-01

    目的 探讨肝硬化CT分级的临床价值.方法 对17例健康正常志愿者、54例肝硬化患者行CT灌注扫描,测量其血流量(BF)、血容量(BV)、肝动脉分数(HAF)、对比剂平均通过时间(MTT)、血管表面通透性(PS),对获得的相应灌注图进行肝硬化分级分析.结果 CT分级肝硬化程度越重,BF、BV越小,MTT、HAF、PS、肝动脉灌注量(HAP)越大.HAF、HAP在正常肝与轻、中、重度肝硬化之间有明显差异,HAF在中、重度肝硬化组明显增高.HAP在重度肝硬化组明显增高,PS、MTT在各组之间没有统计学意义.结论 通过肝脏的CT灌注研究,进一步证明了肝硬化CT分级确实与肝脏的灌注有一定关系,对临床肝硬化评估有一定价值.%Objective To evaluate the clinical value in grading of liver cirrhosis with 64-slice spiral CT perfusion imaging. Methods 17 healthy volunteers and 54 patients with liver cirrhosis underwent liver CT perfusion scanning. The blood flow(BF) , blood vol-ume(BV) , hepatic arterial fraction( HAF) , contrast agent mean transit time(MTT) and vascular permeability surface) PS) were measured on CT perfusion maps. Results CT perfusion imaging showed that the serious of cirrhosis,the lower of perfusion values of BF and BV,the higher of MTT,HAF,PS and hepatic arterial perfusionf HAP). There were significant differences between the normal liver and mild,moderate and severe cirrhosis in HAF and HAP,and HAF in moderate and severe cirrhosis of the liver was significantly increased. HAP in severe liver cirrhosis was significantly higher, PS, MTT between groups was not statistically significant. Conclusion By liver CT perfusion imaging study shows that the CT grading of cirrhosis is of certain relativity with liver perfusion, which is of significant value in evaluating cirrhosis clinically.

  14. Multimodality functional imaging of spontaneous canine tumors using 64CU-ATSM and 18FDG PET/CT and dynamic contrast enhanced perfusion CT

    DEFF Research Database (Denmark)

    Hansen, Anders E; Kristensen, Annemarie T; Law, Ian;

    2012-01-01

    To compare the distribution and uptake of the hypoxia tracer (64)Cu-diacetyl-bis(N(4)-methylthiosemicarbazone) ((64)Cu-ATSM) PET/CT, FDG PET/CT and dynamic contrast enhanced perfusion CT (DCE-pCT) in spontaneous canine tumors. In addition (64)Cu-ATSM distribution over time was evaluated....

  15. A temporal interpolation approach for dynamic reconstruction in perfusion CT.

    Science.gov (United States)

    Montes, Pau; Lauritsch, Günter

    2007-07-01

    This article presents a dynamic CT reconstruction algorithm for objects with time dependent attenuation coefficient. Projection data acquired over several rotations are interpreted as samples of a continuous signal. Based on this idea, a temporal interpolation approach is proposed which provides the maximum temporal resolution for a given rotational speed of the CT scanner. Interpolation is performed using polynomial splines. The algorithm can be adapted to slow signals, reducing the amount of data acquired and the computational cost. A theoretical analysis of the approximations made by the algorithm is provided. In simulation studies, the temporal interpolation approach is compared with three other dynamic reconstruction algorithms based on linear regression, linear interpolation, and generalized Parker weighting. The presented algorithm exhibits the highest temporal resolution for a given sampling interval. Hence, our approach needs less input data to achieve a certain quality in the reconstruction than the other algorithms discussed or, equivalently, less x-ray exposure and computational complexity. The proposed algorithm additionally allows the possibility of using slow rotating scanners for perfusion imaging purposes.

  16. Clinical application with 16-row spiral CT in diagnosis of esophageal hiatal hernia%16层螺旋CT在食管裂孔疝诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    黄婷

    2013-01-01

    目的:探讨16层螺旋CT在食管裂孔疝诊断中的应用价值.方法:回顾25例经胃镜、手术或上消化道造影证实的食管裂孔疝患者的16层螺旋CT资料并加以分析.结果:16层螺旋CT可以清晰显示食管裂孔疝的疝囊大小、部位、形态、密度、膈肌裂孔情况及病变与邻近结构的关系.结论:16层螺旋CT通过薄层断面和多平面重建技术(MPR)可以多角度显示疝囊及内容物,可为肿瘤性病变及其他不明原因膈肌膨隆的鉴别诊断提供有价值的诊断信息.%Objective: To investigate diagnostic value of 16 slice spiral CT in esophageal hiatal hernia. Methods: We reviewed 25 cases by gastroscope, operation or upper gastrointestinal radiography confirmed esophageal hiatal hernia in patients with 16 slice spiral CT data, and analyzed. Results: Image of 16 slice spiral CT could clearly show the esophageal hiatal hernia hernia sac size, position, shape, density, the diaphragmatic hiatus and pathological relationship with adjacent structures. Conclusion: 16 slice spiral CT through thin section and multiplanar reconstruction (MPR) can be multi-angle display hernia sac and contents, especially in the display of the diaphragmatic hiatus of broadening and lesions and their relation to the adjacent tissues have irreplaceable role.At the same time and neoplastic lesions and other unexplained diaphragm bulge in the differential diagnosis of provide valuable diagnostic information.

  17. 胸部DR与低剂量螺旋CT扫描在肺癌筛选中的应用观察%Application and Observation of Thoracic DR and Low Dose Spiral CT Scanning in Lung Cancer Screening

    Institute of Scientific and Technical Information of China (English)

    成洪桥

    2014-01-01

    目的:探讨分析胸部DR与低剂量螺旋CT扫描在肺癌筛选中的应用价值。方法选择来我院进行肺癌治疗的300例患者,对他们分别采用胸部DR以及低剂量螺旋CT扫描,统计两种方法的检出率。结果胸部DR检出结节性病变患者24例,占8%,其中肺癌患者3例;低剂量螺旋CT扫描检出结节性病变患者51例,占17%,其中肺癌患者6例,差异具有统计学意义(P<0.05)。结论采用低剂量螺旋CT扫描在肺癌筛选中的应用价值显著,能明显提高检出率。%Objective To investigate the application value of chest DR and low dose spiral CT scanning in lung cancer screening. Methods 300 patients came to our hospital for treatment of lung cancer, they were used on the chest DR and low dose spiral CT scanning, using statistical method for detection rate. Results Chest DR were detected in 24 cases, patients with nodular lesions accounted for 8%, of which 3 cases of lung cancer patients;low dose spiral CT scanning were detected in 51 cases, patients with nodular lesions accounted for 17%, of which 6 cases of lung cancer patients, with significant difference (P<0.05). Conclusion Using low dose spiral CT scanning in lung cancer screening has significant value, it can significantly improve the detection rate.

  18. Clinical relevance of multislice CT of the spine after osteosynthesis; Postoperative Kontrolle von osteosynthetischen Versorgungen der Wirbelsaeule mit der Mehrzeilen-Spiral-CT

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzen, M.; Wedegaertner; Weber, C.; Adam, G.; Lorenzen, J. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie; Petersen, J.P. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Klinik und Poliklinik fuer Orthopaedie

    2005-11-15

    Purpose: To examine the clinical relevance of multislice CT (MSCT) scans in postoperative checks of the spine after osteosynthesis. Material and Methods: The results of x-rays (apical lateral) in 30 patients having spinal surgery involving Xosteosynthesis (5 x metastasis, 20 x fractures, 3 x spondylolisthesis, 2 x scoliosis) were correlated to those of MSCT (140 kV, 200 mAs, collimation 4 x 1 mm, pitch 0.75; VolumeZoom, Siemens, Erlangen, Germany) with multiplanar reconstruction. Two radiologists independently checked the conventional X-ray and multislice CT scans for anatomical positioning, damage of osteosynthetic material, and intraspinal dislocation of bone fragments. Results: By correlating conventional spinal X-rays with MSCT, additional diagnostic information was gained. In 9 of 30 patients MSCT revealed the extraosseal location of a screw tip (X-ray, 5/30), in 8/30 patients a narrowing of the spinal canal by osteosynthetic material was detected in MSCT (X-ray, 4/30), in 2/30 patients osteal fragments were detected in the vertebral canal by MSCT (X-ray, 0/30). In MSCT and in conventional X-ray a fracture of the osteosynthesis was correctly diagnosed in 3 patients. One patient underwent corrective surgery for dislocated osteosynthetic material, which was solely diagnosed with MSCT. Conclusion: Due to the high degree of additional diagnostic information MSCT seems to be the method of choice for postoperative spinal surgery involving osteosynthesis. (orig.)

  19. 多层螺旋CT对胰腺癌的灌注成像研究%Multiple-slice spiral CT perfusion imaging of pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    程祝忠; 许国辉; 黄娟; 杨宇洁; 曹英; 何韧; 席晓秋

    2008-01-01

    目的 应用MSCT灌注成像技术测量和评价正常胰腺和胰腺癌的血流动力学表现,探讨其在胰腺癌诊断中的临床应用价值.方法 对44例无胰腺疾病患者(正常胰腺患者)、18例胰腺癌患者行MSCT胰腺灌注检查,采用Siemens Bodyperfusion软件测量正常胰腺患者及胰腺癌患者的CT灌注参数值,包括血流量(BF)、血容量(BV)、灌注起始时间(TTS)、峰值到达时间(TTP)、渗透性(permeability)、patlak血流容积(pBV)的平均值,并进行统计学分析.结果 正常胰腺组的BF、BV、TTS、TTP、permeability和pBV分别为:(90.60±29.25)ml·100 ml-1·min-1、(190.35±43.8)ml/L、(205.3±16022)s、(1403.5±334.0)s、(99.47±49.9)05 ml·100ml-1·min-1和(157.8±52.5)ml/L,胰腺癌组的BF、BV、TTS、TTP、permeability和pBV分别为:(22.9±10.63)ml·100 ml-1·min-1、(52.38±18.08)ml/L、(194.3±76.0)s、(1549.5±308.5)s、(115.25±33.55)0.5·100 ml-1·min-1和(83.16±41.45)ml/L.胰腺癌组BF、Bv、pBV明显低于正常组,渗透性高于正常胰腺组,其差异有统计学意义(P0.05).结论 正常胰腺和胰腺癌的CT灌注参数值存在差异,MSCT灌注成像对胰腺癌的诊断有一定的临床价值.%Objective To assess the diagnostic value of multiple-slice spiral CT (MSCT) perfusion imaging technique in pancreatic cancer by measuring and comparing the dynamical characteristics of blood flow between normal pancreas and pancreatic cancer. Methods The CT perfusion imaging were obtained using Siemens Somatoma MSCT scanner in 44 patients with normal pancreas tissue and 18 patients with pancreatic cancer. The mean blood flow (BF),blood volume (BV), time to start (Trs), time to peak (TIP), permeability and patlak blood volume (pBV) were measured and statistically analyzed by using Siemens Body peHusion software package. Results The mean BF, BV, Trs, TIP, permeability and pBV of normal pancreas were: (90.60±29.25) ml·100 ml-1·min-1, (190.35±43.8) ml/L, (205.3±160.2) s, (1403.5

  20. Application Research on Multi-slice Spiral CT Perfusion Imaging in Patients with Acute Cerebral Infarction%多层螺旋 CT 灌注成像在急性脑梗死患者的应用研究

    Institute of Scientific and Technical Information of China (English)

    罗友琛

    2014-01-01

    目的:探讨急性脑梗死患者多层螺旋 CT 灌注成像特点,及其与临床预后的关系。方法选择符合标准的患者40例,行 CT 灌注成像检查,计算脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)及峰值时间(TTP);分别在入院时和治疗后14d 采用美国国立卫生研究院卒中量表(NIHSS)评价临床神经功能缺损,计算缺血脑组织的可恢复比率(PRR)和神经功能恢复比率。结果脑梗死病灶中心 CBV 及 CBF 最低,健侧最高,而缺血半暗带居中,差异有统计学意义(P 0.05);PRR 与患者治疗14d 时 NIHSS 评分存在负相关性(r =-0.340, P 0. 05),negatively dependent of those at day 14 after treatment (r = - 0. 340,P < 0. 05) and positive-ly dependent of patient’s neural functional recovery ratio (r = 0. 467,P < 0. 05). Conclusion Multi-slice spiral CT perfusion im-aging can reflecthemodynamic changes in acute cerebral infarction lesions and their perihemodynamic changes. PRR is closely de-pendent of the neural functional recovery. It can serve as a reliable theoretical basis for clinical treatment.

  1. Comparative analysis of X-ray and spiral CT scan in spinal fractures%脊椎骨折X线平片与螺旋CT对比分析

    Institute of Scientific and Technical Information of China (English)

    刘悌; 李行胜

    2011-01-01

    Objective :To analyze the features of X-ray film and spiral CT scans in spinal fractures for assessment of the diagnostic value. Methods:The imaging data were retrospectively analyzed in 156 cases with vertebral fractures undergone X-ray examination and spiral CT scanning. Results:Of the total 156 cases of spinal fractures, cervical spine fracture was seen in 45, thoracic vertebral fracture in 22, fracture of lumbar vertebra fracture in 79, sacrococcygeal vertebrae fracture in 10, cervicothoracic fracture in 6 and thoracolumbar in 15. X-ray film exposed vertebral fracture in 152(97.44% ), accessory fractures in 35(22.44% ), bone chips in 31 ( 19.87% ), spondylolisthesis of small joints in 25 ( 16.03 ), spinal stenosis in 31 ( 19.87 % ), kyphotic angulation in 43 (27.56%) and vertebra translocation in 23 ( 14.74 ), and the corresponding results by CT scanning were 156 (100%), 53 (33. 97%),46 (29. 49%),40 (26.64%) ,40(26.64%),50(32.05%) and 42(26.92% ) ,respectively. Comparison by x2 test showed the difference between X-ray film and CT scans concerning fractures of vertebra body, bone chips and spinal stenosis and deformation( P > 0.05; P < 0. 05 ). Besides, CT could reveal burst fractures, spinal cord compression, hematoma and soft tissue changes. Conclusion: X-ray film can be primary approach to diagnosis of vertebral fractures, while spiral CT can keep from misdiagnosis due to its function of three dimensional and multiplanar reconstruction.%目的::分析脊椎骨折X线平片与螺旋CT表现,探讨它们对脊椎骨折的诊断价值.方法:回顾分析156例脊椎骨折的X线平片与螺旋CT影像学资料.结果:156例脊椎骨折中,颈椎骨折45例,胸椎骨折22例,腰椎骨折79例,骶尾椎10例;其中颈胸椎骨折6例,胸腰椎骨折15例.X线平片显示椎体骨折、附件骨折、骨碎片、小关节滑脱、椎管狭窄、脊柱后突成角及椎体移位检出率分别为97.44%(152例)、22.44%(35例)、19.87%(31

  2. The new advances of spiral CT diagnosis for intestinal tumors%小肠肿瘤螺旋CT诊断的进展

    Institute of Scientific and Technical Information of China (English)

    易文中; 李维金

    2008-01-01

    小肠是胃肠道最长的器官,因其走行弯曲,肠管常互相重叠,传统的胃肠道和内镜检查单纯地观察消化道腔内结构,尚不能很好显示肠壁和腔外结构.螺旋CT具有快速扫描和三维后处理能力,能清晰反应肠壁和肠腔外的病变.新的影像技术口服大剂量5%等渗甘露醇螺旋CT小肠造影(spiral CT enterography,SCTE)能使小肠充盈良好,对肿瘤的显示、衬托满意,与临床诊断符合率较传统CT高.SCTE是一种简便、安全、非侵袭性、有效评价小肠肿瘤的方法,能明显提高肿瘤的检出率.

  3. Evaluation of Blood Flow Patterns of Solitary Pulmonary Nodules with Dynamic Multi-slice Spiral Computed Tomography

    Institute of Scientific and Technical Information of China (English)

    LIShenjiang; XIAOXiangsheng; LIHuimin; LIUShiyuan; LIChengzhou; ZHANGChenshi; TAOZhiwei; YANGChunshan

    2004-01-01

    To evaluate the efficacy of dynamic multi-slice spiral computed tomography (MSCT) for providing quantitative information about blood flow patterns of solitary pulmonary nodules (SPNs) and differentiating solitary pulmonary nodules (SPNs). Methods: 37 patients with SPNs (diameter0.01). SFN-to-aorta ratio in inflammatory SPNs (20.78%±4.14) was significantly higher than that in benign (2.00%±2.26) and malig nant (14.63%±6.22) SPNs (P0.01). Conclusion: MSCT provides quantitative information about blood flow patterns of solitary pulmonary nodules (SPNs) and is applicable diagnostic method for differentiating SPNs.

  4. Comparison of the Detection Rate of Carotid Artery Therosclerosis Plaque by Means of 16-Director Spiral CT and 320-director Volume CT%16排螺旋CT与320排容积CT对颈动脉粥样硬化斑块检出率的比较研究

    Institute of Scientific and Technical Information of China (English)

    贾云生; 高明洋; 王焕君

    2016-01-01

    目的:比较16排螺旋CT与320排容积CT对于颈动脉粥样硬化斑块检出率的差异。方法选取缺血性脑血管病患者48例,男性22例,女性26例,平均年龄(56±8)岁。经16排螺旋CTA检出颈动脉粥样硬化斑块的患者,进一步行320排容积CTA扫描,并与16排螺旋CTA的粥样硬化斑块检出率进行比较。结果16排螺旋CT与320排容积CT对于颈动脉粥样硬化斑块的检出率无明显统计学差异。结论对于基层医院,建议使用16排螺旋CT检出颈动脉斑块,以利于临床诊断及治疗。%Objective To compare the detection rate of carotid artery therosclerosis plaque by means of 16-director spiral CT and 320- director volume CT.Methods 48 patients of ICVD, 22 males and 26 females, with average age of (56±8) years old, were chosen. The patients detected plaques by 16-director spiral CT scans were further performed 320-director volume CT scans, and we compared the detection rate between the two methods. Results The detection rate of carotid artery therosclerosis plaque between 16-director spiral CT scans and 320-director volume CT scans showed no significant difference. Conclusion We recommend utilizing 16-director spiral CT to detect carotid artery therosclerosis plaque for basic hospital, facilitating the clinical diagnosis and treatment.

  5. 腮腺腺淋巴瘤的多排螺旋CT表现特点%Characteristics of parotid gland lymphoma observed by multi-slice spiral CT

    Institute of Scientific and Technical Information of China (English)

    薛晶; 邹新农; 崔兴宇

    2012-01-01

    目的:探讨腮腺腺淋巴瘤的多排螺旋CT表现特点.方法:对我院经手术病理证实的18例腮腺腺淋巴瘤患者的临床和CT图像资料进行总结分析,所有病例均行CT平扫和增强.结果:男16例,女2例;平均年龄58.7岁,在50岁以上者14例.单侧发病15例,双侧发病3例,共23个病灶;位于腮腺后下象限16个,非后下象限7个;呈类圆形17个,圆形5个,有明显分叶状1个;平均最大径为2.4 cm;境界均清晰光整;密度均匀16个,密度不均伴囊变坏死区7个,CT值为16.2~43.5 Hu.增强扫描早期病灶明显强化18个,中度强化5个,CT值上升平均值为(50.3±15.8)Hu;均匀强化16个,不均匀强化7个;延迟期病灶密度迅速降低21个,缓慢降低2个.结论:腮腺腺淋巴瘤好发于50岁以上男性,多位于腮腺后下象限,CT平扫病灶边界清楚光整,呈均匀或者不均匀稍高密度,增强扫描多明显强化,呈"快进快出"特点.%Objective To evaluate the characteristics of parotid gland lymphoma observed by multi-slice spiral CT. Methods Clinical and CT image data of 18 patients with parotid gland lymphoma which were pathologically confirmed in our hospital were analyzed, all patients received CT scan and enhanced scan. Results Among the 18 patients, 16 were males, 2 were females; the average age was 58.7 years, and 14 patients over the age of 50. Fifteen patients with unilateral lymphoma, and 3 patients with bilateral lymphoma, all accounted to a total of 23 lesions. Among all the 23 lesions, 16 located in the following quadrant, 7 located in the following non-inferior quadrant; 17 were similarly round, 5 were round, and 1 was obviously lobulated; the average maximum diameter was 2.4 cm and the boundaries were clear finishing. The density of 16 lesions were uniform, 7 lesions were uneven with cystic necrosis, and the CT value was 16.2 ~ 43.5 Hu. Enhanced scan showed that 18 lesions were significantly enhanced early, 5 lesions were moderately enhanced, and the

  6. 不同临床分期肾细胞癌的多层螺旋 CT 灌注研究%Study on value of 64 slice spiral CT perfusion in different clinical stages of renal cell carcinoma

    Institute of Scientific and Technical Information of China (English)

    张颖颖; 董莹; 王义云

    2015-01-01

    Objective To evaluate the clinical value 64 slice spiral CT perfusion imaging in diagnosis for differ‐ent stages of renal cell carcinoma .Methods The clinical data of 41 patients with renal cell carcinoma from January 2011 to October 2013 were analyzed retrospectively .Using the pathological examination results as gold standard , blood flow perfusion after treatment ,blood volume(BV) ,peak enhancement (PEI) ,time to peak (TTP) ,mean transit time (MTT) and permeability surface (PS) were compared in differen stages ,evaluation index of CT in diagnosis for renal cell carcinoma staging were calculated .Results There were significant difference on perfusion ,BV ,PEI ,MTT , PS parameters between early and advanced renal cell carcinoma (P0 .05) .The sensitivity ,specificity ,misdiagnosis rate ,missed diagnosis rate and Youden index of renal CT perfusion imaging were 86 .36% ,89 .47% ,10 .53% ,13 .64% ,1 .758 and 0 .758 respetively .Conclusion There is high accuracy of 64 slice spiral CT perfusion imaging in diagnosis for different stages of renal cell carcinoma , which is worthy of application and promotion .%目的:探讨利用64排螺旋C T灌注成像技术对不同分期肾细胞癌进行诊断的临床价值及方法。方法回顾性分析莱芜市人民医院2011年1月至2013年10月收治的41例肾细胞癌患者的临床资料,以病理学检查结果作为临床分期的金标准,比较不同分期肾细胞癌的CT灌注成像经灌注软件包处理后的血流量(Perfusion),血容量(BV),峰值强化(PEI),达峰时间(TTP),平均通过时间(MTT),表面通透性(PS)指标的差异,同时计算CT诊断肾细胞癌分期的诊断学评价指标。结果早期肾细胞癌和晚期肾细胞癌的Perfusion、BV、PEI、M T T、PS参数比较,差异有统计学意义(P<0.05),而TTP参数比较差异无统计学意义(P>0.05)。采用CT 灌注成像技术诊断肾细胞癌分期的灵敏度为86.36

  7. Slice spiral CT diagnosis of intestinal lymphoma(8 reports were enclosed)%多层螺旋CT诊断肠道淋巴瘤8例

    Institute of Scientific and Technical Information of China (English)

    汪勇; 葛锋铭; 周作斌

    2014-01-01

    Objective To investigate the diagnostic value of multi-slice spiral CT(MSCT) for intestinal lymphoma. Methods Multi-slice CT performance of 8 patients with intestinal lymphoma confirmed by surgical pathology was analyzed retrospectively.All the patients received plain scan,enhanced dual-phase scan and multi-planar reconstruction aftertreatment. Results This group of cases included 1 case of duodenum,4 cases of small intestine and 3 cases of colon.The plain scan found uniform lesion density and the enhanced scan found mild to moderate enhancement.Five patients had different degrees of intestinal obstruction,but no complete intestinal tube obstruction occurred.The intestinal wall thickened obviously and the thickness was about 1.8-5cm.Multiple enlarged lymph nodes were observed in the 5 cases of thickened intestinal tubes. Conclusion The imaging performance of intestinal lymphoma has certain features,thickened intestinal walls, scarce direct periphery invasion,commonly seen enlarged lymph nodes around the intestinal walls,mild to moderate enhancement. Combining multi-planar reconstruction,spiral CT has important diagnosis value for locating and determining the nature of intestinal lymphoma.%目的:探讨多层螺旋CT(MSCT)诊断肠道淋巴瘤价值。方法回顾性分析经手术病理证实的8例肠道淋巴瘤的多层螺旋CT表现。全部病例均作平扫及增强双期扫描,并做多平面重建后处理。结果该组病例来源于十二指肠1例,小肠4例,结肠3例,平扫病灶密度较均匀,增强后出现轻至中度强化,5例出现不同程度肠梗阻征象,但未出现肠管完全梗阻,肠管壁增厚明显,厚度约1.8~5cm,5例增厚的肠管周围可见多发增大的淋巴结。结论肠道淋巴瘤的影像学表现有一定特征,肠壁增厚,很少向周围直接浸润,肠壁周围增大淋巴结常见,轻度至中度强化,结合多平面重建,螺旋CT肠道淋巴瘤定位定性有重要的诊断价值。

  8. Diagnostic Value of Brain Perfusion Imaging with 64 Multi-Detector Spiral CT in Early Cerebral Infarction%64排螺旋 CT 脑灌注成像对早期脑梗死的诊断价值

    Institute of Scientific and Technical Information of China (English)

    奚彬; 盛伟华; 唐建伟; 黄松; 宋黎涛

    2014-01-01

    目的:探讨64排螺旋 CT 脑灌注成像(CT perfusion imaging,CTP)对早期脑梗死的诊断价值。方法:临床拟诊早期脑梗死患者38例,均在症状出现24 h 内行头颅 CT 平扫及 CTP 检查。将脑梗死核心区、缺血半暗带(ischemic penumbra,IP)区与健侧对应区的情况做对比分析。结果:38例患者中,15例头颅 CT 平扫发现可疑脑梗死区,主要位于大脑半球,表现为密度轻度减低、局部脑沟稍变浅等;其余23例患者 CT 平扫未发现异常。38例患者的 CTP 检查均发现灌注异常区,表现为脑梗死区脑血流量(cerebral blood flow,CBF)与脑血容量(cerebral blood volume,CBV)均较健侧对应区明显下降,对比剂平均通过时间(mean transit time,MTT)较健侧对应区缩短,对比剂达峰时间(time to peak,TTP)较健侧对应区明显延长,差异均有统计学意义(P <0.01)。早期脑梗死患者 IP 区与梗死核心区比较,CBF、CBV、MTT 及 TTP 差异均有统计学意义(P <0.01);IP区与健侧对应区比较,CBF、MTT、TTP 差异均有统计学意义(P <0.05、0.01),CBV 差异无统计学意义(P >0.05)。获得随访的18例患者中,经积极溶栓等治疗后梗死区缩小6例,梗死区消失5例,仅表现为梗死区 TTP 和 MTT 延长、CBF 和 CBV 变化不大3例,梗死区无明显变化4例。结论:64排螺旋 CTP 检查可以准确地提示早期脑梗死。%Objective:To explore the diagnostic value of CT perfusion imaging(CTP)with 64 multi-detector spiral CT in early cerebral infarction.Methods:A total of 38 patients with suspected early cerebral infarction underwent plain CT and CTP within 24 h after the onset of related symptoms.The imaging results in infarction core area,ischemic penumbra (IP) and the contralateral normal region were comparatively analyzed.Results:Early cerebral infarction,mainly in cerebral hemispheres, were suspected

  9. 螺旋CT显示膝关节软组织损伤技术探讨%Spiral CT showed the knee joint of soft tissue injury technology discussed in this paper

    Institute of Scientific and Technical Information of China (English)

    秦妍滨; 于明

    2016-01-01

    目的:研究分析螺旋C T技术对于膝关节软组织损伤的诊断效果。方法:选取我院近年收治的36例膝关节软组织损伤患者作为研究对象,所有患者在入院后均通过了CT检查,收集所有患者的CT检查资料,以及CT检查结果,分析应螺旋CT对膝关节软组织损伤检查的操作方法以及诊断效果。结果:应用螺旋CT技术能清晰地显示患者膝关节各类骨折、关节腔、部分韧带以及软组织损伤,对膝关节软组织损伤具有较高的临床诊断价值。结论:螺旋CT联合多种重建技术对膝关节软组织损伤患者具有较高的临床诊断价值,值得在临床上广泛地推广应用。%Objective To study the analysis of the spiral CT technology to the diagnosis effect of knee joint of soft tissue injury. Methods Selection of 36 patients with knee joint soft tissue injury were admitted in our hospital in recent years as the research object, all of the patients in the hospital after all through the CT examination, all patients with CT examination information collection, and CT examination results, the analysis should be spiral CT examination to knee joint of soft tissue injury operation method and the effect of diagnosis.Results Spiral CT can clearly show that patients with knee joint fracture, articular cavity, part of the ligaments and soft tissue injury, the clinical diagnostic value of knee joint of soft tissue injury with high.Conclusion Spiral CT in combination with a variety of technical reconstruction in patients with knee joint soft tissue injury has high clinical diagnostic value, is worth popularizing widely in clinic application.

  10. Value Analysis of Spiral CT for the Diagnosis of Senile Psychosis Patient's Combined Obstruction%螺旋CT在老年精神病合并肠梗阻患者诊断中的价值分析

    Institute of Scientific and Technical Information of China (English)

    李华; 肖国强

    2015-01-01

    目的:分析螺旋CT在老年精神病合并肠梗阻患者诊断中的价值。方法:选取我院收治的老年精神病合并肠梗阻患者50例,首先进行X线腹部平片的检查,后给予螺旋CT检查,对不同检测手段对患者的诊断结果进行分析。结果:螺旋CT准确诊断比例、误诊比例、肠梗阻性质、部位、患者满意度等均明显优越于X线检查,差异具有统计学意义( P<0.05)。结论:螺旋CT扫描检查对老年精神病合并肠梗阻患者诊断准确性高,误诊比例低,在老年精神病合并肠梗阻患者的诊断和治疗中具有较高的临床意义。%Objective:To analyze the application value of spiral CT for the diagnosis of senile psychosis patient's combined obstruction. Methods:50 cases senile psychosis patient's combined obstruction in our hospital were diagnosed using abdominal X-ravplainfilm and spiral CT, the results of diagnosis after using different method were analyzed.Results:the accurate diagnosis ratio, misdiagnosis rate, the nature and position of the obstruction by using spiral CT were significantly better than abdominal X-ravplainfilm, the differences were sta-tistically significant.Conclusions:It showed a high accurate diagnosis ratio and low misdiagnosis rate by using spiral CT for the diagnosis of senile psychosis patient's combined obstruction and high clinical significance by using spiral CT for the diagnosis of senile psychosis patient's combined obstruction.

  11. Application of Spiral CT in the Diagnosis of Sacroiliac Joint Disease in Ankylosing Spondylitis%螺旋CT在强直性脊柱炎骶髂关节病变诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    任蓬程; 刘建宁; 池华玲; 李秉忠

    2014-01-01

    目的探讨螺旋CT在强直性脊柱炎骶髂关节病变诊断中的应用价值。方法收集强直性脊柱炎骶髂关节病变的患者117例,均行X线平片和螺旋CT检查,对比分析两者的诊断效果。结果螺旋CT诊断骶髂关节对各级病变准确数高于X线平片,差异有统计学意义(P<0.05)。螺旋CT对关节面侵蚀、软骨钙化、关节面下囊变和骨质增生、软组织肿胀等的检出率高于X线平片,差异有统计学意义(P<0.05)。结论螺旋CT可以清晰显示强直性脊柱炎骶髂关节病变的组织特征,客观准确地反应骶髂关节受累程度,为临床诊断和治疗提供重要的影像学依据。%Objective To investigate the value of spiral CT in diagnosis of sacroiliac joint disease in ankylosing spondylitis. Methods 117 ankylosing spondylitis patients who all underwent spiral CT and X-ray examinations were chosen, comparative analysis of the effect of both diagnoses was made. Results Spiral CT in the diagnosis of sacroiliac joint lesions was more accurate at all levels than X-ray plain film, and the difference was statistically significant (P<0.05). Rate of detection by spiral CT in articular surface e-rosion, calcified cartilage, subchondral cystic degeneration, hyperplasia of bone and soft tissue swelling was higher than that of X-ray plain film, with statistically significant difference (P<0.05). Conclusion Spiral CT could clearly show the organizational features of sacroiliac joint in ankylosing spondylitis, objective and accurate response of sacroiliac joint involvement, and provide important imaging evidence for clinical diagnosis and treatment.

  12. Clinical evaluation of dynamic CT scan of the pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Tokuda, Masamichi

    1984-09-01

    The clinical usefulness of dynamic CT scans (DCT) of the pancreas was evaluated in 62 normal cases, 9 cases of acute pancreatitis, 24 cases of chronic pancreatitis and 43 cases of carcinoma of the pancreas. The normal pancreas was intensely and homogeneously enhanced on DCT, and peripancreatic vessels were clearly demonstrated, especially the gastroduodenal artery (98.4%). DCT was useful to demonstrate vascular lesions, associated with pancreatitis such as pseudoaneurysm. Although the carcinoma of the pancreas showed poor contrast enhancement on conventional enhanced CT (CCT), 37.2% showed intense contrast enhancement on DCT. Visualization of the gastroduodenal artery by DCT is helpful to decide the extent of tumor. DCT is superior to CCT in demonstrating collateral veins caused by tumor invasion to the portal system in carcinoma. DCT was approximately as accurate as angiography (92.6%) in evaluating tumor invasion to the portal system. DCT is a useful and minimally invasive modality in assessing the resectability of pancreatic carcinoma. DCT may eliminate angiography and surgery in unresectable cases. (author).

  13. Characterization of multiple spiral wave dynamics as a stochastic predator-prey system

    Science.gov (United States)

    Otani, Niels F.; Mo, Alisa; Mannava, Sandeep; Fenton, Flavio H.; Cherry, Elizabeth M.; Luther, Stefan; Gilmour, Robert F., Jr.

    2008-08-01

    A perspective on systems containing many action potential waves that, individually, are prone to spiral wave breakup is proposed. The perspective is based on two quantities, “predator” and “prey,” which we define as the fraction of the system in the excited state and in the excitable but unexcited state, respectively. These quantities exhibited a number of properties in both simulations and fibrillating canine cardiac tissue that were found to be consistent with a proposed theory that assumes the existence of regions we call “domains of influence,” each of which is associated with the activity of one action potential wave. The properties include (i) a propensity to rotate in phase space in the same sense as would be predicted by the standard Volterra-Lotka predator-prey equations, (ii) temporal behavior ranging from near periodic oscillation at a frequency close to the spiral wave rotation frequency (“type-1” behavior) to more complex oscillatory behavior whose power spectrum is composed of a range of frequencies both above and, especially, below the spiral wave rotation frequency (“type-2” behavior), and (iii) a strong positive correlation between the periods and amplitudes of the oscillations of these quantities. In particular, a rapid measure of the amplitude was found to scale consistently as the square root of the period in data taken from both simulations and optical mapping experiments. Global quantities such as predator and prey thus appear to be useful in the study of multiple spiral wave systems, facilitating the posing of new questions, which in turn may help to provide greater understanding of clinically important phenomena such as ventricular fibrillation.

  14. 肺癌特异血管征象的64层CT首过期灌注增强表达%Expressing the specific vessels signs in lung cancer by 64-slice spiral CT in first phase perfusion imaging *

    Institute of Scientific and Technical Information of China (English)

    苏冠琴; 薄晓庆; 杨署; 孙国鹏; 柴军; 周苛; 高阿枚; 段呼兵; 董秀萍

    2013-01-01

    Objective To investigate the specific vessels signs in lung cancer by 64-slice spiral CT in first phase perfusion ima-ging so as to get more reasonable time about CT angiography .Methods Among the 47 cases ,there were 38 cases of central and 9 cases of peripheral primary lung cancer underwent 64-slice spiral CT in first phase perfusion imaging :one scan was obtained every 1 seconds during 8-38 seconds with 8 section × I without scanning interval after injection .Precontrast and postcontrast attenuation on every leisions was recorded ,to calculate the peak height(PH) and peak height time by time density curves TDC of pulmonary le-sions to aorta ,those reflect the the tumor feeding artery Imaging about lesions of lung cancer and inflammation .observed and calcu-lated the display rate and display time of lesions of lung cancer and inflammation .means of t test was used for statistics .Results a-bout the peak heights of in pulmonary artery and aorta phese ,statistically significant differences were found between inflammation and lung cancer(P0 .05) . about the peak heights time in aorta phase ,no statistically significant differences were found among three groups (P>0 .05) .The tumor vascularity were discoved in lesions in patients with lung cancer (44/47 cases ,93 .62% );The erosion narrow pulmonary ar-tery were discoved in central lung cancer (37/38 cases ,97 .37% ) ,in peripheral lung cancer(6/9 cases 66 .67% );no abnormal pulmo-nary artery were discoved only in 4 patients with lung cancer .Both tumor vascularity and abnormal pulmonary artery were most dis-plaied in 18-31s in CT angiography .Conclusion 64-slice spiral CT in first phase dynamic perfusion imaging can order completely show the specific vessels signs in lung cancer and reflect the tumor feeding artery Imaging of lung cancer .Analysising those benefi-ted to select reasonably the time of CT angiography and Improve the rate of lung cancer diagnosis .%目的分析64层C T首过期灌注增强对肺癌特

  15. Influence analysis of secondary O-ring seals in dynamic behavior of spiral groove gas face seals

    Science.gov (United States)

    Hu, Songtao; Huang, Weifeng; Liu, Xiangfeng; Wang, Yuming

    2016-05-01

    The current research on secondary O-ring seals used in mechanical seals has begun to focus on their dynamic properties. However, detailed analysis of the dynamic properties of O-ring seals in spiral groove gas face seals is lacking. In particular a transient study and a difference analysis of steady-state and transient performance are imperative. In this paper, a case study is performed to gauge the effect of secondary O-ring seals on the dynamic behavior (steady-state performance and transient performance) of face seals. A numerical finite element method (FEM) model is developed for the dynamic analysis of spiral groove gas face seals with a flexibly mounted stator in the axial and angular modes. The rotor tilt angle, static stator tilt angle and O-ring damping are selected to investigate the effect of O-ring seals on face seals during stable running operation. The results show that the angular factor can be ignored to save time in the simulation under small damping or undamped conditions. However, large O-ring damping has an enormous effect on the angular phase difference of mated rings, affecting the steady-state performance of face seals and largely increasing the possibility of face contact that reduces the service life of face seals. A pressure drop fluctuation is carried out to analyze the effect of O-ring seals on the transient performance of face seals. The results show that face seals could remain stable without support stiffness and O-ring damping during normal stable operation but may enter a large-leakage state when confronting instantaneous fluctuations. The oscillation-amplitude shortening effect of O-ring damping on the axial mode is much greater than that on the angular modes and O-ring damping prefers to cater for axial motion at the cost of angular motion. This research proposes a detailed dynamic-property study of O-ring seals in spiral groove gas face seals, to assist in the design of face seals.

  16. Cholestrol granuloma of the breast incidentally detected on dynamic abdominal CT: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Sun Hye; Lee, Eun Hye; Hong, Hyun Sook; Kwak, Jeong Ja [Soonchunhyang University College of Medicine, Bucheon Hospital, Bucheon (Korea, Republic of)

    2016-01-15

    A breast cholesterol granuloma is an uncommon nodular breast lesion. We incidentally detected a persistently enhancing breast mass on the dynamic abdominal computed tomography (CT) of a 78-year-old woman. The mass decreased in diameter over 50 days following a core needle biopsy. This report is the first to describe the dynamic-enhanced CT features of a breast cholesterol granuloma.

  17. Evaluation of spiral CT imaging in the diagnosis of the primary ureteral carcinoma%原发性输尿管癌的螺旋CT表现与病理对照分析

    Institute of Scientific and Technical Information of China (English)

    Xiuli Zhang; Dongmei Guo; Xiyou Zhang; Shen Lv

    2007-01-01

    Objective: To explore the characteristics of the primary ureteral carcinoma (PUC) and discuss the value of spiral CT (SCT) in the diagnosis of PUC. Methods: The SCT findings of the primary ureteral carcinoma in 16 cases were analyzed and compared with the histopathological diagnosis and staging. Results: The transverse diameters of the lesions were1.0-2.1 cm, and the longitudinal lengths were 1.5-15.2 cm. There were no statistically significant differences (P>0.1) in diameters and lengths among the low staging group (pT0-T2) and the high staging group (pT3-T4). The average CT value of the lesions was 43 HU on plain scanning, and 73 HU on CE scanning. The increment was 30 HU. The lesions were clearer on CE scanning. Curved planar reconstruction (CPR) could show the entire course of the urinary tract. Among 6 cases of pT3 stage,CT gave a correct diagnosis in 1 case. For 2 cases of pT4 stage, CT gave correct diagnoses in both cases. Conclusion: The carcinomatous lesions spread along the ureter. The longitudinal length of each lesion is longer than its transverse diameter.Tumor cannot be staged merely according to its diameter and length. CT is difficult to differentiate stage T0-T3, while for stage T4, CT diagnosis is accurate. Contrast enhancement CT scanning has the confirming and differentiating roles. CPR offers direct and easy observing images for clinical doctors.

  18. Spiral symmetry

    CERN Document Server

    Hargittai, Istvan

    1992-01-01

    From the tiny twisted biological molecules to the gargantuan curling arms of many galaxies, the physical world contains a startling repetition of spiral patterns. Today, researchers have a keen interest in identifying, measuring, and defining these patterns in scientific terms. Spirals play an important role in the growth processes of many biological forms and organisms. Also, through time, humans have imitated spiral motifs in their art forms, and invented new and unusual spirals which have no counterparts in the natural world. Therefore, one goal of this multiauthored book is to stress the c

  19. Application of 64-slice spiral CT and post-processing technique in evaluation of Crohn's disease%64层螺旋CT检查及后处理技术在Crohn病中的应用

    Institute of Scientific and Technical Information of China (English)

    沈永菊; 冷永新; 唐翠松; 汤光宇

    2012-01-01

    目的 探讨64层螺旋CT及各种后处理技术在Crohn病中的应用.方法 对32例Crohn病患者CT扫描图像进行回顾性分析,由两位资深放射科医师对原始图像进行VR、MIP、MPR后处理.结果 Crohn病的影像学表现为:(1)肠壁增厚;(2)肠壁强化;(3)肠系膜的异常改变;(4)并发症.结论 MSCT检查可清楚显示肠壁及肠腔外病变,可得到更多的解剖和血流灌注的信息,对Crohn病的诊断、判断疾病活动度及并发症有优越性.%Objective To assess the application of multiple post-processing technique of 64-slice spiral CT in diagnosis of Crohn's disease. Methods Thirty two patients with Crohn's disease confirmed by endoscopic and pathological examination underwent 64-slice spiral CT scan. The images were reconstructed with volume rendering, maximum intensity projection, multiplanar reconstruction by two senior radiologists. Results The CT features of Crohn's disease included intestinal wall thickening, enhancement of the intestinal wall, abnormal changes of the mesentery and the complicating disease. Conclusion The 64-Slice spiral CT scan provides more information of the anatomy and blood perfusion of the lesions, which has unique superiority in diagnosis of Crohn's disease and complications.

  20. Characteristic manifestations of disseminated peritoneal adenomucinosis on multislice spiral CT%播散性腹膜黏液腺病多层螺旋CT诊断分析

    Institute of Scientific and Technical Information of China (English)

    徐丽莹; 周云峰; 吴光耀; 廖美焱; 田志雄; 张在鹏; 黄雄

    2012-01-01

    回顾性分析11例播散性腹膜黏液腺病患者的CT资料,11例患者中有9例显示为弥漫性凝胶状腹水,2例显示为局限性囊性肿块.9例弥漫性病例中5例伴腹腔多发囊性结节或肿块影,5例伴大网膜或肠系膜网状浸润.11例患者中6例出现肝脏或脾脏扇形压迹,5例出现肝脏或脾脏实质浸润,5例于囊性结节或肿块内出现弧线状、结节状钙化.6例女性患者中3例有卵巢黏液性囊腺瘤.所有病例均未见腹腔及腹膜后淋巴结肿大,未见网膜饼征象.提示播散性腹膜黏液腺病具备特征性CT征象.%Clinical data and manifestations on muhi-slice spiral CT (MSCT) of 11 patients with disseminated peritoneal adenomucinosis (DPAM) were retrospectively reviewed.The CT manifestations were also compared with surgical and histopathological findings.MSCT findings showed a large amount of gel-like ascites in 9 cases and local cystic masses in 2 cases.Among 9 cases with a large amount ascites,abdominal multiple cystic masses were shown in 5 case,and infiltration of the greater omentum and mesentery in 5 cases.Hepatic scalloping was found in 6 cases ; parenchymal invasion of the liver or spleen were showed in 5 cases; calcification of the cystic masses in 5 cases.Ovary mueinous cystadenoma was presented in 3 female patients.Enlarged lymph nodes and omental cake were not found in all cases.The results indicate that the characteristic MSCT manifestations of DPAM include diffuse gel-like ascites,multiple cystic masses with or without calcification,hepatic scalloping and parenchyma invasion.

  1. Diagnosis of acute mesenteric ischemia with multi-slice spiral CT%急性肠系膜缺血的MSCT诊断

    Institute of Scientific and Technical Information of China (English)

    贾乾君; 梁长虹; 张水兴; 刘再毅

    2011-01-01

    目的:探讨MSCT对急性肠系膜缺血的诊断价值.方法:回顾性分析经手术或介入治疗证实的36例急性肠系膜缺血患者的CT表现.所有患者均行CT检查,包括平扫、增强扫描动脉期、增强扫描门脉期并进行血管重建.后处理采用容积显示技术(VRT)、多平面重组(MPR)和薄层最大密度投影(MIP)进行动脉和门脉成像.结果:肠系膜上动脉栓塞5例,肠系膜上动脉狭窄6例,肠系膜上静脉血栓形成25例.CT直接征象为血管内充盈缺损(30例)或狭窄(6例).间接征象包括:肠管扩张、肠腔内积液积气(22例),肠壁增厚(14例),肠壁薄纸样改变(3例),肠壁积气(3例).肠系膜脂肪水肿及渗出(4例).结论:MSCT与其三维重组技术相结合是诊断急性肠系膜缺血的一种有效且无创的影像检查方法,可以明确阻塞动脉的部位及范围,对手术有较高的指导价值.%Objective : To study the clinical value of multi-slice spiral CT(MSCT) in the diagnosis of acute mesenteric ischemia. Methods:The CT features of 36 patients with surgery/interventional therapy proved acute mesenteric ischemia were reviewed retrospectively. All patients underwent MSCT scanning,including plain scan, arterial phase and portal vein phase scanning after contrast administration. Post-processing techniques including volume rendering, multi-planar reformation and thin-section maximum intensity projection were performed to assess the mesenteric artery and vein, as well as the portal vein. Results:There were 5 cases of superior mesenteric artery embolism,6 cases of superior mesenteric artery stenosis and 25 cases of superior mesenteric vein thrombosis. The direct CT signs were filling defect (n=30) or stenosis (n=6)of mesenteric vessels. The indirect CT signs includcd: dilatation of bowel loops with air-fluid levels (n=22) , bowel wall thickening ( n= 14) , paper-like thin wall sign ( n= 3) , pneumatosis of bowel wall ( n= 3) , edema and exudation of mesenteric

  2. The study on multi-spiral CT perfusion for severe acute pancreatitis%重症急性胰腺炎多层螺旋CT灌注研究

    Institute of Scientific and Technical Information of China (English)

    邵娟; 卜平; 征锦; 孔桂美

    2008-01-01

    Objective To evaluate the characteristics of the CT perfusion for severe acute pancreatitis. Methods We performed CT perfusion scan on three groups of 9, 17and 41 cases with severe,mild and normal pancreatitis respectively, using 16 rows spiral CT, and got the perfusion data of the relevant groups including blood flow (BL), blood volume(BV), mean transit time( MTT), capillary permeability(PS)with perfusion package 3. We analize the data deviation between the groups mentioned above. Furthmore, we still adapt correlation test to compare the clinical biochemical indicators of MAP and SAP, with the variance BF. Results The mean values of BF, BV reduce significally in the groups of MAP, SAP compared to thenormal group(P<0.01 ), only PS goes higher than that of the normal group(P<0.05). At the same time,they are obviously higher in MAP group than in SAP group. In MAP group, the level of blood hemodiastase and BF are negatively correlated, on the contray, in SAP group, the level of the blood hemodiastase has no relation to BF. Conclusions CT perfusion techniques are of great significance in early diagnosis in SAP, and in guiding the clinical therapy.%目的 探讨SAP的CT灌注特点,评价其临床价值.方法 使用16排螺旋CT对9例SAP患者、17例MAP患者以及41例胰腺正常者进行CT灌注扫描.应用perfusion 3软件包进行数据处理,计算各组的血流量(BF)、血容量(BV)、平均通过时间(MTT)、毛细血管通透性(IS)等灌注参数,并行独立样本t检验.结果 MAP组的BF、BV平均值为(121.5±55.27)ml·100 mg-1·min-1、(11.7±5.26)ml/100 mg,SAP组平均值为(63.58±36.91)ml·100 mg-1·min-1、(7.13±2.11)ml/100 mg,差异显著(P<0.01);较正常组的(219.17 4.98.02)ml·100 mg-1·min-1和(18.60±14.75)ml/100 mg,均显著降低(P<0.01).MAP组和SAP组的PS分别为(25.14±10.7)ml·100 mg-1·min-1和(34.61±11.25)ml·100 mg-1·min-1,均高于正常组的(16.61 ±9.36)ml·100 mg-1·min-1(P<0.05).结论 CT灌注成像技术

  3. 多层螺旋CT肛缘定位的研究%The anal verge: localization with multi-slice spiral CT

    Institute of Scientific and Technical Information of China (English)

    汪伟; 唐光健

    2010-01-01

    Objective To determine and evaluate the method of localization of anal verge by mutislice spiral CT. To provide an imaging reference for operative guidance of low-rectal cancer. Methods Forty eight consecutive adult patients suspected of abnormalities other than rectal disease were evaluated with abdominal and pelvic CT scans since August, 2009. They were divided into two groups based on sex and age. There were 23 men and 25 women. The ages of young group were 28 to 50 years and the average age was 41 years. The ages of elderly group were 52 to 81 years and the average age was 64 years. A small cotton ball dipped with contrast media was put at the anal verge as a marker and CT scans were performed with 64-slice spiral CT scanner. The distances between the cotton balls and the lower margin of the pubis combination (La), the lower margin of the 5th sacral vertebra (Lb), the inferior aperture of minor pelvis(Lc) and the lower margin of the basement of external anal sphincter (Ld) were measured on the midsagittal images obtained by MPR. The averages, the standard deviations(s), the 95% and 80% confidence intervals of La, Lb, Lc and Ld were calculated. We took the intervals of ± 1.96 s or ± 1.28 s < 5 mm as the standard of meeting the clinical requirement. The distances meeting the clinical requirement between different sex groups or age groups were compared with t test. Results The Ld was (9.8 ± 1.2) mm, ofwhich intervals of ± 1.96 s and ± 1.28 s were 4. 8 mm and 3.0 mm respectively, meeting the clinical need.This distance was also measured conveniently. There were no significant differences ( P > 0.05 ) between two different sex groups [ male group, ( 10.0 ± 1.2) mm], female group, (9.6 ± 1.2) mm and between two age groups [ young group, (9.6 ± 1.2) mm, elderly group, ( 9.9 ± 1.3 ) mm ]. Conclusions The lower margin of the basement of external anal sphincter was a useful anatomic lanmark for localizing the anal verge,and could be definitely identified on

  4. Spiral-wave dynamics in a mathematical model of human ventricular tissue with myocytes and fibroblasts.

    Science.gov (United States)

    Nayak, Alok Ranjan; Shajahan, T K; Panfilov, A V; Pandit, Rahul

    2013-01-01

    Cardiac fibroblasts, when coupled functionally with myocytes, can modulate the electrophysiological properties of cardiac tissue. We present systematic numerical studies of such modulation of electrophysiological properties in mathematical models for (a) single myocyte-fibroblast (MF) units and (b) two-dimensional (2D) arrays of such units; our models build on earlier ones and allow for zero-, one-, and two-sided MF couplings. Our studies of MF units elucidate the dependence of the action-potential (AP) morphology on parameters such as [Formula: see text], the fibroblast resting-membrane potential, the fibroblast conductance [Formula: see text], and the MF gap-junctional coupling [Formula: see text]. Furthermore, we find that our MF composite can show autorhythmic and oscillatory behaviors in addition to an excitable response. Our 2D studies use (a) both homogeneous and inhomogeneous distributions of fibroblasts, (b) various ranges for parameters such as [Formula: see text], and [Formula: see text], and (c) intercellular couplings that can be zero-sided, one-sided, and two-sided connections of fibroblasts with myocytes. We show, in particular, that the plane-wave conduction velocity [Formula: see text] decreases as a function of [Formula: see text], for zero-sided and one-sided couplings; however, for two-sided coupling, [Formula: see text] decreases initially and then increases as a function of [Formula: see text], and, eventually, we observe that conduction failure occurs for low values of [Formula: see text]. In our homogeneous studies, we find that the rotation speed and stability of a spiral wave can be controlled either by controlling [Formula: see text] or [Formula: see text]. Our studies with fibroblast inhomogeneities show that a spiral wave can get anchored to a local fibroblast inhomogeneity. We also study the efficacy of a low-amplitude control scheme, which has been suggested for the control of spiral-wave turbulence in mathematical models for cardiac

  5. Low dose scanning of 64 slice spiral CT in the diagnosis of pneumothorax in neonates%64层螺旋CT低剂量扫描在新生儿气胸诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    武军; 李彦杰

    2015-01-01

    目的:探讨64层螺旋CT低剂量扫描在新生儿气胸诊断中的应用,分析新生儿气胸的CT表现特点,以提高对新生儿气胸的认识及CT的诊断水平。方法用64层螺旋CT对23例临床可疑新生儿气胸进行低电压、低电流和增大螺距进行扫描,并对图像进行分析。结果患儿有不同类型的CT表现,如外侧肺气胸、内侧纵隔旁气胸、膈面附近及胸前部气胸等。结论新生儿肺气胸有一定的临床CT特征,对及时发现新生儿气胸,对临床诊断并及时处理有重要意义。%Objective Application of low dose of 64 row spiral CT scanning in the diagnosis of pneumothorax in neonatal pneumothorax, analysis CT charac-teristics, in order to improve the diagnostic level of understanding and CT on neonatal pneumothorax. Methods Twenty-three patients with clinically suspected of pneumothorax in neonates of low voltage, low current and increasing pitch were scanned by 64 slice spiral CT. And the image analysis. Results Patients with CT showed different types, such as lateral lung chest,medial mediastinum side pneumothorax, diaphrag-matic surface and near the front of pneumothorax. Conclusion Neonatal lung chest clinic and CT features, the timely detection of pneumothorax in neonates, for clinical diagnosis and timely treatment is meaningful.

  6. Diagnosis of traumatic hemarthrosis lipemia by multi-slice spiral CT and magnetic resonance imaging features%创伤性关节积脂血症的多排螺旋CT及磁共振成像诊断

    Institute of Scientific and Technical Information of China (English)

    沈丽荣; 姜兆候; 张立云; 刘永明

    2014-01-01

    Objective To evaluated traumatic hemarthrosis lipemia multi-slice spiral CT and magnetic resonance imaging (MRI) features and diagnostic value. Methods A retrospective analysis of multi-slice spiral CT and MRI features in 23 cases patients with traumatic hemarthrosis hyperlipidemia. All patients were examinated after injury bet-ween one hour to one week by 16-slice spiral CT or MRI, of which 19 cases of knee, hip 4 cases, all patients under-went multi-slice spiral CT, images were transmitted to a workstation for multi-planar reconstruction (MPR), shaded surface display (SSD), volume rendering (VR) and other three-dimensional restructuring, 15 cases of parallel MRI. Results Twenty three patients were joint capsule appeared fat-blood interface sign, including one case of suspected fracture CT, MRI was clear. In 23 patients, a single liquid-liquid plane 17 cases, two liquid-liquid flat 6 cases, liquid-liquid flat top were fat. Conclusion There are characteristic imaging findings of traumatic hemarthrosis lipemia examined by multi-slice spiral CT and MRI , three-dimensional multi-slice spiral CT examination and restructuring can be used as the preferred; MRI is the best imaging method in diagnostic plot lipemia traumatic knee; Plot lipemia can be used as a indirect dia-gnostic signs of intraarticular fractures.%目的:探讨创伤性关节积脂血症的多排螺旋CT及磁共振成像(MRI)影像学特点及诊断价值。方法回顾性分析23例创伤性关节积脂血症患者的多排螺旋CT及MRI影像学特征。所有患者于受伤后1 h至1周内行16排螺旋CT和(或)MRI检查,其中,膝关节19例,髋关节4例,所有患者均行多排螺旋CT检查,图像均传递到工作站进行多平面重组、表面遮盖法、容积再现等三维重建,15例并行MRI检查。结果23例患者关节囊均出现脂肪-血液界面征,其中1例CT可疑骨折,行MRI检查明确诊断。23例患者中,单液-液平面的17

  7. Low dose dynamic myocardial CT perfusion using advanced iterative reconstruction

    Science.gov (United States)

    Eck, Brendan L.; Fahmi, Rachid; Fuqua, Christopher; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

    2015-03-01

    Dynamic myocardial CT perfusion (CTP) can provide quantitative functional information for the assessment of coronary artery disease. However, x-ray dose in dynamic CTP is high, typically from 10mSv to >20mSv. We compared the dose reduction potential of advanced iterative reconstruction, Iterative Model Reconstruction (IMR, Philips Healthcare, Cleveland, Ohio) to hybrid iterative reconstruction (iDose4) and filtered back projection (FBP). Dynamic CTP scans were obtained using a porcine model with balloon-induced ischemia in the left anterior descending coronary artery to prescribed fractional flow reserve values. High dose dynamic CTP scans were acquired at 100kVp/100mAs with effective dose of 23mSv. Low dose scans at 75mAs, 50mAs, and 25mAs were simulated by adding x-ray quantum noise and detector electronic noise to the projection space data. Images were reconstructed with FBP, iDose4, and IMR at each dose level. Image quality in static CTP images was assessed by SNR and CNR. Blood flow was obtained using a dynamic CTP analysis pipeline and blood flow image quality was assessed using flow-SNR and flow-CNR. IMR showed highest static image quality according to SNR and CNR. Blood flow in FBP was increasingly over-estimated at reduced dose. Flow was more consistent for iDose4 from 100mAs to 50mAs, but was over-estimated at 25mAs. IMR was most consistent from 100mAs to 25mAs. Static images and flow maps for 100mAs FBP, 50mAs iDose4, and 25mAs IMR showed comparable, clear ischemia, CNR, and flow-CNR values. These results suggest that IMR can enable dynamic CTP at significantly reduced dose, at 5.8mSv or 25% of the comparable 23mSv FBP protocol.

  8. Spiral tectonics

    Science.gov (United States)

    Hassan Asadiyan, Mohammad

    2014-05-01

    Spiral Tectonics (ST) is a new window to global tectonics introduced as alternative model for Plate Tectonics (PT). ST based upon Dahw(rolling) and Tahw(spreading) dynamics. Analogues to electric and magnetic components in the electromagnetic theory we could consider Dahw and Tahw as components of geodynamics, when one component increases the other decreases and vice versa. They are changed to each other during geological history. D-component represents continental crust and T-component represents oceanic crust. D and T are two arm of spiral-cell. T-arm 180 degree lags behind D-arm so named Retard-arm with respect to D or Forward-arm. It seems primary cell injected several billions years ago from Earth's center therefore the Earth's core was built up first then mantel and finally the crust was build up. Crust building initiate from Arabia (Mecca). As the universe extended gravitation wave swirled the earth fractaly along cycloid path from big to small scale. In global scale (order-0) ST collect continents in one side and abandoned Pacific Ocean in the other side. Recent researches also show two mantels upwelling in opposite side of the Earth: one under Africa (tectonic pose) and the other under Pacific Ocean (tectonic tail). In higher order (order-1) ST build up Africa in one side and S.America in the other side therefore left Atlantic Ocean meandered in between. In order-n e.g. Khoor Musa and Bandar-Deylam bay are seen meandered easterly in the Iranian part but Khoor Abdullah and Kuwait bay meandered westerly in the Arabian part, they are distributed symmetrically with respect to axis of Persian Gulf(PG), these two are fractal components of easterly Caspian-wing and westerly Black Sea-wing which split up from Anatoly. Caspian Sea and Black Sea make two legs of Y-like structure, this shape completely fitted with GPS-velocity map which start from PG and split up in the Catastrophic Point(Anatoly). We could consider PG as remnants of Ancient Ocean which spent up

  9. Application of low-dose 16-slice spiral CT scanning technology in adenoidal hypertrophy in children%16层螺旋CT低剂量扫描技术在儿童腺样体肥大中的应用

    Institute of Scientific and Technical Information of China (English)

    党保华; 曲金荣; 张建伟; 刘翠翠; 黎海亮

    2012-01-01

    目的:探讨16层螺旋CT低剂量扫描技术在儿童腺样体肥大的临床应用.方法:对46例临床疑似腺样体肥大儿童行16层螺旋CT低剂量和常规剂量扫描,将其随机分为两组,时比两种剂量扫描的图像质量与患者的辐射剂量.结果:16层螺旋CT低剂量扫描与常规剂量扫描对显示鼻咽部的解剖结构及病变差异无显著性意义(P=0.381).对低剂量组/常规剂量组两组腺样体CT值平均值之间无统计学差异(P=0.256).CT值标准偏差之间无统计学差异(P=0.313).低剂量CT扫描显示儿童鼻咽部扫描参数中CTDIvol为4.35 mGy、DLP为40.62 mGy·cm,常规剂量CTDIvol为8.65 mGy、DLP为81.23 mGy·cm.低剂量与常规剂量相比,其CTDIvol和DLP降低了约50%的辐射剂量.结论:16层螺旋CT低剂量扫描对腺样体肥大的诊断结果与常规剂量均相同,故16层螺旋CT低剂量扫描临床疑似腺样体肥大的患者,完全能替代常规剂量的16层螺旋CT扫描.%Objective:To investigate clinical application value of low-dose 16-slice spiral CT scanning technology in the adenoidal hypertrophy of children. MethodS:46 cases of children with adenoidal hypertrophy underwent low-dose (group A) and conventional-dose (group B) 16-slice spiral CT scanning. The image quality and radiation dose in two groups were compared. Results: The display of the anatomical structure of the nasopharynx and adenoidal hypertrophy showed no significant difference between low-dose CT scanning and conventional-dose CT scanning (P = 0. 381). It showed no significant difference in the mean of CT values (P=0. 256) and the standard deviation of CT values (P=0. 313) between low-dose and conventional-dose scanning. The CTDIvol of low-dose CT scanning was 4. 35mGy,and DLP was40. 62mGy ·cm,and the CTDIvol of conventional doses was 8. 65mGy,DLP was 81. 23mGy-cm. The CTDIvol and DLP of low-dose CT scanning decreased about 50% as compared with those of conventional dose scanning. Conclusion

  10. Whole-brain dynamic CT angiography and perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Orrison, W.W. [CHW Nevada Imaging Company, Nevada Imaging Centers, Spring Valley, Las Vegas, NV (United States); College of Osteopathic Medicine, Touro University Nevada, Henderson, NV (United States); Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Department of Medical Education, University of Nevada School of Medicine, Reno, NV (United States); Snyder, K.V.; Hopkins, L.N. [Department of Neurosurgery, Millard Fillmore Gates Circle Hospital, Buffalo, NY (United States); Roach, C.J. [School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States); Ringdahl, E.N. [Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV (United States); Nazir, R. [Shifa International Hospital, Islamabad (Pakistan); Hanson, E.H., E-mail: eric.hanson@amigenics.co [College of Osteopathic Medicine, Touro University Nevada, Henderson, NV (United States); Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States)

    2011-06-15

    The availability of whole brain computed tomography (CT) perfusion has expanded the opportunities for analysing the haemodynamic parameters associated with varied neurological conditions. Examples demonstrating the clinical utility of whole-brain CT perfusion imaging in selected acute and chronic ischaemic arterial neurovascular conditions are presented. Whole-brain CT perfusion enables the detection and focused haemodynamic analyses of acute and chronic arterial conditions in the central nervous system without the limitation of partial anatomical coverage of the brain.

  11. Image quality of ultra-low radiation exposure coronary CT angiography with an effective dose <0.1 mSv using high-pitch spiral acquisition and raw data-based iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Schuhbaeck, Annika; Achenbach, Stephan; Hecker, Franziska; Rixe, Johannes [University of Giessen, Department of Cardiology, Giessen (Germany); Layritz, Christian; Eisentopf, Jasmin; Pflederer, Tobias; Gauss, Soeren; Kalender, Willi; Daniel, Werner G.; Lell, Michael; Ropers, Dieter [University of Erlangen, Departments of Cardiology and Radiology, Erlangen (Germany)

    2013-03-15

    We evaluated the potential of prospectively ECG-triggered high-pitch spiral acquisition with low tube voltage and current in combination with iterative reconstruction to achieve coronary CT angiography with sufficient image quality at an effective dose below 0.1 mSv. Contrast-enhanced coronary dual source CT angiography (2 x 128 x 0.6 mm, 80 kV, 50 mAs) in prospectively ECG-triggered high-pitch spiral acquisition mode was performed in 21 consecutive individuals (body weight <100 kg, heart rate {<=}60/min). Images were reconstructed with raw data-based filtered back projection (FBP) and iterative reconstruction (IR). Image quality was assessed on a 4-point scale (1 = no artefacts, 4 = unevaluable). Mean effective dose was 0.06 {+-} 0.01 mSv. Image noise was significantly reduced in IR (128.9 {+-} 46.6 vs. 158.2 {+-} 44.7 HU). The mean image quality score was lower for IR (1.9 {+-} 1.1 vs. 2.2 {+-} 1.0, P < 0.0001). Of 292 coronary segments, 55 in FBP and 40 in IR (P = 0.12) were graded ''unevaluable''. In patients with a body weight {<=}75 kg, both in FBP and in IR, the rates of fully evaluable segments were significantly higher in comparison to patients >75 kg. Coronary CT angiography with an estimated effective dose <0.1 mSv may provide sufficient image quality in selected patients through the combination of high-pitch spiral acquisition and raw data-based iterative reconstruction. (orig.)

  12. 16层螺旋CT血管成像在腹主动脉瘤中的诊断价值%The Value of 16-slice Spiral CT Angiography in the Diagnosis of Abdominal Aortic Aneurysm

    Institute of Scientific and Technical Information of China (English)

    谭迎杰

    2014-01-01

    Objective To evaluate the diagnostic value of 16-slice spiral CT angiography for abdominal aortic aneurysm. Methods 28 patients with abdominal aortic aneurysm underwent 16-slice spiral CT angiography in our hospital from 2011 to 2013 were se-lected as the subjects, and the lesion detection was analyzed. Results Confirmed by operation or DSA, 28 patients with abdominal aortic aneurysm included 9 cases of abdominal aortic dissection aneurysm, 2 cases of pseudo abdominal aortic aneurysm, and 17 cases of true abdominal aortic aneurysm;3 cases of abdominal aortic aneurysm ruptured. Conclusion 16-slice spiral CT angiogra-phy has certain advantages in the diagnosis of abdominal aortic aneurysm, which is worthy of clinical promotion and application.%探讨16层螺旋CT血管成像在腹主动脉瘤中的诊断价值。方法研究对象为该院收治的28例腹主动脉瘤患者,均行16层多排螺旋CT血管成像,分析其病变检出情况。结果经过手术或DSA证实,28例腹主动脉瘤患者包括9例腹主动脉夹层动脉瘤、2例假性腹主动脉瘤及17例真性腹主动脉瘤,3例患者腹主动脉瘤出现破裂。结论16层螺旋CT血管成像对腹主动脉瘤的诊断具有一定优势,值得临床上推广应用。

  13. 16排螺旋CT在膀胱移行细胞癌中的应用%The Clinical Value of Spiral CT in the Diagnosis of Bladder Cancer

    Institute of Scientific and Technical Information of China (English)

    胡承雷; 刘玥

    2011-01-01

    Objective: To evaluate the clinical diagnostic value of bladder cancer with spiral CT.Methods:A retrospective analysis of 36 cases confirmed by operation and pathology for transitional cell carcinoma of bladder cancer in patients with CT and clinical data.Results: 36 patients with CT were detected in 33 cases, 3 cases showed no abnormalities. CT shows the limitations of bladder wall thickening in 7 cases, a cauliflower-like to intrapericardial hemiation in 23 cases, 6 cases of papillary protruding into the cavity .Conclusion: Spiral CT can clear the diagnosis and staging of bladder cancer, provide clinic more accurate noninvasive diagnosis and the prognosis can be assessed.Clinical application value is high in the clinical application.%目的:探讨16排螺旋CT对膀胱移行细胞癌的诊断价值.方法:回顾性分析36例经手术病理证实为膀胱移行细胞癌癌患者的CT及临床资料.结果:36例术前CT检出33例,3例未见异常.CT表现为局限性膀胱壁增厚7例,呈菜花状向腔内突出23例,乳头状突向腔内6例;增强扫描肿块均有不同程度强化.结论:16排螺旋CT对膀胱移行细胞癌的诊断有其独特的优越性,临床应用价值较高,可在临床推广应用.

  14. Study on Diagnostic value of X-ray and Spiral CT in Lumbar Vertebrae de-generation%X线片与螺旋CT对腰椎退变的诊断价值研究

    Institute of Scientific and Technical Information of China (English)

    张小凤

    2015-01-01

    目的:探讨腰椎退变采取X线片与螺旋CT的诊断价值。方法整群选取于2013年6月-2014年7月来院诊断的96例腰椎退变患者作为研究对象,所有患者均行X线片及螺旋CT诊断,比较两种诊断方法的影像学表现。结果在诊断腰椎骨质增生及椎间小关节退变方面,X线片的检出率优于CT,差异均有统计学意义;在许莫氏结节方面,CT的检出率(6.25%)优于X线片的(1.04%),差异有统计学意义(χ²=3.8643,P<0.05)。结论CT能直观显示X线片不能显示的某些退变征现象,X线片与螺旋CT诊断结合,对腰椎退变的诊断和治疗有重要作用。%Objective To explore the value of X-ray and spiral CT in the diagnosis of Lumbar Vertebrae degeneration. Methods 96 patients were taken as the research objects which suffered from the osteoarthritis of Lumbar Vertebrae and accepted treatments in our hospital from July, 2013 to July, 2014. these patients were treated by diagnostic X-ray and spiral CT, then, imaging mani-festations of two diagnostic methods were compared. Results In the showing signs of hyperostosis and degeneration of intervertebral small joints and intervertebral space narrowing, X-ray was superior to CT and the differences was statistical significance (P<0.05). In addition, in the showing Schmor's nodes, the detection rate of CT (6.25%) is superior to X-ray (1.04%) and the differences was statistical significance (χ²=3.8643,P<0.05). Conclusion CT can directly display the phenomenon of some degeneration, X-ray can-not. In combination with X-ray and spiral CT diagnosis, it is important for diagnosis and therapy of degenerative lumbar spine.

  15. High-Dynamic-Range CT Reconstruction Based on Varying Tube-Voltage Imaging

    Science.gov (United States)

    2015-01-01

    For complicated structural components characterized by wide X-ray attenuation ranges, the conventional computed tomography (CT) imaging using a single tube-voltage at each rotation angle cannot obtain all structural information. This limitation results in a shortage of CT information, because the effective thickness of the components along the direction of X-ray penetration exceeds the limitation of the dynamic range of the X-ray imaging system. To address this problem, high-dynamic-range CT (HDR-CT) reconstruction is proposed. For this new method, the tube’s voltage is adjusted several times to match the corresponding effective thickness about the local information from an object. Then, HDR fusion and HDR-CT are applied to obtain the full reconstruction information. An accompanying experiment demonstrates that this new technology can extend the dynamic range of X-ray imaging systems and provide the complete internal structures of complicated structural components. PMID:26544723

  16. High-Dynamic-Range CT Reconstruction Based on Varying Tube-Voltage Imaging.

    Directory of Open Access Journals (Sweden)

    Ping Chen

    Full Text Available For complicated structural components characterized by wide X-ray attenuation ranges, the conventional computed tomography (CT imaging using a single tube-voltage at each rotation angle cannot obtain all structural information. This limitation results in a shortage of CT information, because the effective thickness of the components along the direction of X-ray penetration exceeds the limitation of the dynamic range of the X-ray imaging system. To address this problem, high-dynamic-range CT (HDR-CT reconstruction is proposed. For this new method, the tube's voltage is adjusted several times to match the corresponding effective thickness about the local information from an object. Then, HDR fusion and HDR-CT are applied to obtain the full reconstruction information. An accompanying experiment demonstrates that this new technology can extend the dynamic range of X-ray imaging systems and provide the complete internal structures of complicated structural components.

  17. 128层螺旋CT扫描容积重建诊断肋骨骨折的临床价值%Value of volume vendering after 128-slice spiral CT in the diagnosis of rib fracture

    Institute of Scientific and Technical Information of China (English)

    董延鸣; 徐伟; 石渠

    2013-01-01

    目的 探讨128 层螺旋CT扫描容积重建诊断肋骨骨折的临床价值.方法 回顾性分析100 例378根肋骨及20 根肋软骨骨折病例,采用薄层(0.625 mm)重组、容积再现(VR)重建技术进行肋骨及肋软骨重建,并在工作站上进行多角度、全方位动态观察.结果 100 例肋骨发现320 根378 处骨折,其中多发骨折85 例305 根,单发性骨折15 例;单侧肋骨骨折78 例257 根,双侧骨折22 例共121 根;肋软骨骨折20 例,不全性骨折45 根.合并肺挫伤35 例,气胸26 例,血气胸18 例,脾挫裂伤8 例、肝挫裂伤3 例.结论 胸部外伤患者行128 层螺旋CT常规扫描后,薄层重组结合容积重建对肋骨骨折及其并发症的诊断有非常重要的价值.%Objective To investigate the value of volume vendering after 128-slice spiral CT in the diagnosis of rib fracture. Methods The clinical data of 100 patients (378 rib fractures and 20 costalcartilages fractures) were retrospectively analyzed. The thin-slice reconstruction (0.652 mm), volume vendering (VR) were applied for the reconstruction of rib and costalcartilages. Multi-angel, comprehensive, dynamic observation in the workstation was performed. Results A total of 378 rib fractures in 320 ribs were found, including multiple rib fracture in 305 ribs in 85 patients, comminuted rib fracture in 15 ribs in 15 patients, of which 257 fractured ribs were on the same side (in 78 patients) and 121 were on two sides (in 22 patients). A total of 20 patients with costalcartilages fractures were found, with 45 ribs of incomplete rib fracture. Thirty-five patients were found with lung contusion, 26 with pneumothorax, 18 with hemopnemothorax, 8 with dampened spleen and 3 with dampened liver. Conclusion Thin-slice reconstruction and volume vendering after 128-slice spiral CT scan has very important value in the diagnosis of ribs fracture and complications in patients with chest trauma.

  18. A differentiated approach to the diagnosis of pulmonary embolism and deep venous thrombosis using multi-slice CT; Abklaerung von Lungenembolie und venoeser Thromboembolie mittels Mehrschicht-Spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Wildberger, J.E.; Mahnken, A.H.; Stargardt, A.; Haage, P.; Guenther, R.W. [Klinik fuer Radiologische Diagnostik (Germany); Sinha, A.M. [Medizinische Klinik 1, Universitaetsklinikum der RWTH Aachen (Germany); Schaller, S. [Siemens Medical Solutions, Computertomographie, Forchheim (Germany)

    2002-03-01

    ] Zielsetzung: Entwicklung eines diagnostischen Algorithmus fuer Mehrschicht-Spiral CT (MSCT) Untersuchungen bei klinisch vermuteter Lungenembolie (LE) mittels CT-Angiographie (CTA) und indirekter CT-Phlebographie (CTP). Material und Methode: Bei 161 konsekutiven Patienten mit klinischem Verdacht einer LE wurde nach intravenoeser Applikation von 120 ml Kontrastmittel eine duennschichtige CTA durchgefuehrt (SOMATOM Volume Zoom; Siemens, Forchheim; 120 kV, 100 mAs, Kollimation: 4 x 1 mm). Eine indirekte CTP (120 kV, 170 mAs, Kollimation: 4 x 5 mm) wurde in den Faellen angeschlossen, in denen eine LE bestaetigt werden konnte. Bei negativer CTA wurde diese nur bei den Patienten durchgefuehrt, bei denen klinische Zeichen bzw. vorausgegangene Untersuchungen eine tiefe Beinvenenthrombose (TVT) wahrscheinlich machten oder dies zur weiteren Therapieplanung und Ausdehnungsbestimmung erforderlich war. Beginnend am Beckenkamm wurde die CTP drei Minuten nach KM-Applikation in der Kniekehle beendet. Ergebnisse der CTP konnten bei 73 Extremitaeten mit dopplersonographischen, phlebographischen oder autoptischen Ergebnissen verglichen werden. Die Untersuchungsbereiche wurden bei allen Patienten aufgezeichnet und resultierende effektive Strahlendosen fuer beide Geschlechter getrennt berechnet. Ergebnisse: Bei 62 Patienten konnte der Verdacht einer Lungenembolie in der CTA bestaetigt werden. 47 dieser Patienten hatten eine ursaechliche TVT. Bei 47/99 Patienten ohne LE-Nachweis wurde eine zusaetzliche CTP durchgefuehrt. Hierbei wurde die Diagnose einer TVT aus vorauslich bei 2 von 39 Patienten (5,1%) wurde eine okkulte TVT ohne Nachweis einer LE festgestellt. Bei den Vergleichsuntersuchungen lag die Sensitivitaet fuer den Nachweis einer TVT bei 94,3% bei einer Spezifitaet von 92,1%. Nach ICRP 60 wurden kumulative effektive Strahlendosen fuer die Thorax-CT von 3,3 mSv fuer maennliche und 4,2 mSv fuer weibliche Patienten berechnet, fuer die CTP ergaben sich 9,3 mSv. Schlussfolgerungen: Das

  19. Validation of CT brain perfusion methods using a realistic dynamic head phantom

    NARCIS (Netherlands)

    Riordan, A.J.; Prokop, M.; Viergever, M.A.; Dankbaar, J.W.; Smit, E.J.; Jong, H.W. de

    2011-01-01

    PURPOSE: Development and evaluation of a realistic hybrid head phantom for the validation of quantitative CT brain perfusion methods. METHODS: A combination, or hybrid, of CT images of an anthropomorphic head phantom together with clinically acquired MRI brain images was used to construct a dynamic

  20. Clinical significance of spiral CT and post-processing techniques in guiding orbital fracture repair%螺旋 CT 及后处理技术引导眼眶骨折修复的临床观察

    Institute of Scientific and Technical Information of China (English)

    马丽; 侯明杰; 杜灵艳

    2014-01-01

    Objective To evaluate the clinical significance of spiral CT and post-processing techniques in the diagnosis and prosthesis of orbital wall fracture caused by ocular trauma.Methods The clinical data of 86 patients ( 86 eyes ) with orbital wall fracture who received care in the Department of Ophthalmology,the People′s Hospital of Jiaozuo,Henan,China between October 2010 and November 2011 were retrospectively analyzed.All patients underwent surgical repair of orbital wall fracture with microporous high-density polyethylene implant ( MEDPOR ) filled with hydroxyapatite after 64-thin slice spiral CT scanning and the reconstructive diagnosis through the volume rendering technique and multi-planar reconstruction ( MPR) technique.Results The MPR image clearly revealed the soft tissue incarceration and the status of hernia on the orbital floor,and the volume rendering technique adequately showed the three-dimensional structure of the orbital fracture.During the postoperative follow-up ( range from 3 months to 2 years), 45 (86.5%) injured eyes were completely corrected and 7 (13.5%) were partly corrected.In the 62 patients with diplopia, 39 ( 62.9%) achieved an excellent outcome ( complete disappearance of diplopia) ,20 ( 32.2%) achieved a good outcome ( almost complete disappearance of diplopia ) , but 3 (4.9%)experienced a significant lesion aggravation,after operation.Conclusion Spiral CT and the various available post-processing techniques are very helpful to ophthalmologists in the preoperative investigations of the location and extent of orbital wall fracture and thereby may significantly impact the diagnosis and treatment of orbital wall fracture.%目的:探讨螺旋CT及多种后处理技术对眼眶壁骨折患者的诊断及骨折修复术中的指导价值。方法回顾性分析2010年10月至2013年11月河南省焦作市人民医院眼科收治的86例(86只眼)眶内壁骨折患者的临床资料。采用64层螺旋CT机对患者进行薄层扫描,

  1. Comparison of image quality between axial and spiral scan mode in routine head CT%常规头部CT螺旋扫描与轴扫描模式的影像质量对照

    Institute of Scientific and Technical Information of China (English)

    傅强; 刘晓菲; 于虹; 徐克

    2012-01-01

    目的 通过头部CT螺旋扫描和轴扫描两种不同扫描模式的影像质量对照,探讨常规头部CT采用螺旋扫描模式取代轴扫描模式的可行性.方法 40例患者,其中男性24例,女性16例;年龄18 ~ 74岁,平均年龄46岁.分别接受头部CT螺旋扫描和轴扫描两种不同模式扫描,轴扫描参数:140 kV、170 mA用于颅底部;120 kV、150 mA用于颅脑部,每周2s.螺旋扫描参数:120 kV,150 mA,每周0.6 s.扫描剂量直接取自设备剂量指示值(CTDI和DLP).影像质量分别由2位专家采用双盲法,对头部CT的颅底、脑灰-白质层面及全部影像逐层进行CT值测量评估.结果 常规头部CT螺旋扫描模式较轴扫描模式可有效去除颅底部伪影,并能减少扫描时间和扫描剂量(轴扫描模式与螺旋扫描模式对比,CTDI 55.43 mGy/37.80 mGy;DLP 662.10 mGy· cm/498.28 mGy· cm;扫描时间12.0 s/7.2 s)(P< 0.001).结论 常规头部CT螺旋扫描模式的影像质量完全可与轴扫描模式相媲美,并可取代轴扫描模式.同时常规头部CT螺旋扫描模式还具有可减少扫描时间和辐射剂量,并可进行影像的二维和三维后处理,有利于提高微小病灶正确诊断率的优越性.%Objective To assess the feasibility of replacing axial CT scan mode with spiral CT scan mode in routine head CT through comparing the image quality between spiral and routine axial (sequential) acquired head CT. Methods A total of 40 cases were enrolled, male 24, female 16; aged 18 - 74 years old, mean age 46 years old. They were performed spiral scan and axial scan, respectively. Scan parameter axial mode were 140 kV, 170 mA for petrou bone, and 120 kV, 150 mA for brain, scan time 2.0 s/rol; and spiral mode were 120 kV, 150 mA, scan time 0.6 s/rol. Radiation dose were measured directly from the CT scan indicated computed tomography dose index (CTDI) and dose-length product (DLP). The image quality at the level of the posterior fossa and grey -white matter

  2. Multi-slice Spiral CT Manifestation of Parotid Tumors%腮腺肿瘤的多层螺旋CT表现

    Institute of Scientific and Technical Information of China (English)

    侯学文; 张利中

    2016-01-01

    Objective To investigate the multi-slice spiral CT (MSCT) features of parotid tumors to provide clinical references. Methods Retrospective analysis was conducted on the MSCT manifestation of 23 patients whose diagnosis of parotid tumors were confirmed surgically and pathologically (including 3 cases of mucoepidermoid carcinoma, 11 cases of pleomorphic adenoma, 4 cases of adenolymphoma, 2 cases of lipoma, 2 cases of eosinophilic lymphocytes in the granuloma, 1 case of benign myoepithelial tumor). Through the CT manifestation tumor distribution, form, density, edge, cystic degeneration or necrosis, degree of enhancement, cervical lymph node enlargement of 23 cases were studied. Results Most pathological changes of the parotid gland were unilateral, of which 15 were left and 8 were right. Benign tumors usually located at the junction of the superficial lobe of parotid glands and the deep lobe of parotid glands. The shape of benign tumors was round or mass. The boundary was clear, and the density was uniform and higher than the normal parotid gland tissue. As shown by enhancing scanning, the calcification was found in the multiple adenomas and the cystic changes were found in the pleomorphic adenoma. Malignant tumors were usually located in deep lobes and were lobulated. The boundary was less clear. The density was uneven and more dense than normal parotid gland. Enhanced scan revealed inhomogeneous enhancement. Malignant parotid tumors were often accompanied by cervical lymph node enlargement. Conclusion Parotid gland tumors have certain imaging features. MSCT is helpful in the diagnosis and differential diagnosis and has important clinical diagnostic value.%目的:探讨腮腺肿瘤的多层螺旋CT表现,为临床提供参考。方法回顾性分析23例经手术病理证实的腮腺肿瘤患者(粘液表皮样癌3例,多形性腺瘤11例,腺淋巴瘤4例,脂肪瘤2例,嗜酸性淋巴细胞肉芽肿2例,肌上皮良性病变1例)的多层螺旋CT

  3. Vascular anatomy of the liver and porta hepatis with dynamic CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Hiramatsu, Yoshihiro; Wada, Mitsuyoshi; Nakajima, Teiichi; Tonooka, Reiko; Matsumoto, Kunihiko

    1983-01-01

    Vascular anatomy of the liver and porta heaptis demonstrated by dynamic CT scan was studied Identification of the individual vessels was sometimes difficult due to slight differencies in respiratory depths among the scans. Limitation in the number of slices also made the evalution of the vascular anatomy difficult. Angiography was therefore utilized for comparison in identifying the vessels. Dynamic CT scan was proved to be usefull in demonstrating the anteroposterior relationship of the vessels and surrounding structures, which is difficult with convetional angiography without multiple projections. Three dimensional understanding of the vessels was then possible with dynamic CT scan and angiography. When combined with recently advancing digital subtraction angiography, dynamic CT scan might reduce the necessity for conventional angiography with Seldinger's technique. (author).

  4. 64排螺旋CT仿真结肠镜在结肠癌诊断中的应用%Clinical application of 64-slice spiral CT virtual colonoscopy in diagnosis of colonic carcinoma

    Institute of Scientific and Technical Information of China (English)

    张明

    2012-01-01

    目的 探讨64排螺旋CT仿真结肠镜(CT virtual colonoscopy,CTVC)及其二维三维重建在结肠占位的CT表现及临床应用.方法 回顾分析52例行64排螺旋CT双体位结肠扫描的结肠癌病例,所有患者均进行结肠充气仰卧位及俯卧位增强扫描,其中20例增加了左或右侧位三期扫描,将MSCT扫描原始数据传送至ADW4.4工作站采用CT仿真结肠镜(CTVC)、多平面重建(MPR)、表面遮盖显示(SSD)、透明重建显示(Raysum)4种方法进行结肠重建处理,对病灶的形态、大小、密度、结肠壁受损的程度、范围以及结肠外情况、淋巴结转移情况进行综合分析,做出准确判断.结果 结肠、直肠癌52例,全部病例均经过手术及纤维结肠镜检查活检病理证实.结论 MSCT仿真结肠镜可显示结肠占位病变的形态、大小及肠壁、肠周侵犯情况,多体位扫描能使病变肠管扩张充分,更好地显示病灶的细节,提高病变检出的敏感性,为临床选择合理的治疗提供有价值的依据,是诊断结肠占位的一种有效检查方法.%Objective To investigate the CT manifestations and diagnostic value of 64 - slice spiral CT virtual colonoscopy (CTVC) and its 2D/3D - reslruction in colonic neoplasms. Methods 64 - slice spiral CT scan of colon was performed in 52 patients, Spiral CT enhancing scan was performed in both the supine and prone positions after appropriately distended by introduction of air and water, and triple - phase spiral CT enhanced scan were additionally performed in 20 of 52 cases, and the data of MSCT were transferred to ADW4.4 workstation for colon reconstruction image post processing including CT virtual colonoscopy (CTVC) , multiple planar reconstruction (MPR) , shaded surface display (SSD) and Raysum display. The MSCT findings of the shape, size and density of lesions, the injury extent and range of colonic wall and extracolon, and lymph node metastasis were analyzed and estimated. Results Totally 52

  5. 64排螺旋CT重建技术在急性阑尾炎诊断中的应用价值%application of 64-Slice Spiral CT Reconstruction Technique in diagnosis of acute appendicitis

    Institute of Scientific and Technical Information of China (English)

    任春慧; 冯华; 梁爽; 曲世巍

    2013-01-01

    Objective To investigate the effectiveness of 64-slice spiral CT reconstruction technique in diagnosis of acute appendicitis. Methods Retrospective analysis of 64-slice spiral CT scan images was performed on 60 patients who underwent abdominal 64-slice spiral CT scans and were confirmed through clinical pathology as acute appendicitis sufferers. After multi-planar and curve reconstruction of all the images in the workstation, observation and analysis of appendicitis were made on the size, morphology and surrounding changes. Results Among 60 patients with acute appendicitis, 21 cases were found acute simple appendicitis, 32 superlative appendicitis, 5 appendiceal abscess, 2 appendiceal perforation. Two kinds of features - direct and indirect features could be gained from 64-slice spiral CT findings. Direct features include thickened and enlarged appendicitis(diameter> 6 mm), thickened wall of the appendicitis, appendicitis calculus. Indirect features included inflammation, abscess or inflammatory mass around the appendicitis, free intraperitoneal gas and swelling local lymph nodes. Conclusion Acute appendicitis had typical features in its CT iamges. Application of 64-slice spiral CT reconstruction techniques could have a better reveal of appendicitis and its surrounding circumstances, which significantly improved the diagnosis of appendicitis and was of great application value.%  目的探讨64排螺旋CT重建技术在急性阑尾炎诊断中的应用价值。方法对60例经临床病理证实的急性阑尾炎患者的64排螺旋CT扫描资料进行回顾性分析,所有患者行全腹部64排螺旋平扫,所得图像在工作站进行多平面及曲面重建,对阑尾的大小、形态及周围改变进行观察分析。结果60例资料中,急性单纯性阑尾炎21例、化脓性阑尾炎32例、阑尾脓肿5例、阑尾穿孔2例。64排螺旋CT直接征象为阑尾增粗、增大(直径>6 mm),阑尾壁增厚,阑尾结石;间接征象

  6. 腰椎多层螺旋CT低剂量扫描参数优化的研究%Study of Multi-slice Spiral CT Low-dose Scanning Parameters Optimization in the Lumbar Spine

    Institute of Scientific and Technical Information of China (English)

    董艳军; 张磊磊; 唐晓; 白男男; 胡蓬勃; 郭兰田

    2014-01-01

    目的:评价不同扫描条件腰椎多层螺旋CT扫描对成像质量及辐射剂量的影响,探讨多层螺旋CT在腰椎软组织病变扫描中适宜的低剂量扫描参数。方法通过CT设备扫描患者腰椎,以240 mAs为起点,逐渐降低管电流量,记录CT主机上显示的辐射剂量;评价图像质量采用adw 4.3工作站,统计学处理采用SPSS18.0软件。结果管电流量80 mAs扫描所获得的图像评分均不低于3分,其产生的辐射剂量为6.81 mGy;而管电流量240 mAs扫描所获得的图像评分均为4分,其产生的辐射剂量为20.22 mGy。结论腰椎软组织多层螺旋CT低剂量扫描的适宜扫描参数为80 mAs。%Objective To evaluate the effect of lumbar spine multiple-slice spiral CT different scanning schemes on image quality and radiation dose and investigate the suitable low-dose scanning parameters of multiple-slice spiral CT in lumbar spine soft tis-sue lesions. Methods We scanned the patients' lumbar spine by CT equipment. We started with 240mAs and gradually reduced mAs. We also recorded the radiation dose showed by the CT host computer and evaluated image quality by the adw 4.3 worksta-tion. We analyzed data through SPSS 18.0. Results All image quality scores were no less than 3 points at 80mAs, and the radia-tion dose at 80mAs was 6.81mGy. All image quality scores were 4 points at 240mAs, and the radiation dose at 240mAs was 20.22mGy. Conclusion The suitable multiple-slice spiral CT low-dose scanning parameters in the lumbar spine soft tissue lesions is 80mAs.

  7. Spiral CT in congenital pectus excavatum%螺旋CT在先天性漏斗胸中的应用价值

    Institute of Scientific and Technical Information of China (English)

    徐龙春; 赵雷

    2011-01-01

    目的:利用螺旋CT研究Haller指数、胸骨凹陷深度和心脏旋转角在漏斗胸诊治中的价值.方法:70例漏斗胸患儿手术前后均行螺旋CT检查.Haller指数测定法:胸部最大内横径与同层面最小前后内径的比值.心脏旋转角:椎体前缘矢状线及其与心尖连线的夹角.在横轴面CT图像上测量胸骨凹陷深度(d).测量患者组和正常对照组手术前后Haller指数、心脏旋转角及胸骨凹陷深度,并进行统计学分析.结果:70例患者均显示有不同程度的胸骨凹陷.手术前测量的Haller指数为5 37±1.91,手术后为3.41±1.62,两者间差异有极显著性意义(t=6.32,P<0.01).手术前心脏旋转角为65.7°±9.81°,手术后为61.4°±8 67°,两者间差异有显著性意义(t=2.57,P<0.05).随着Haller指数增大,心脏旋转角也逐渐增大,两者间呈正相关(r=0.87,P<0.01).手术前测量的胸骨凹陷深度为(19.2±7.2)mm,手术后为(9 1±4.1) mm,两者间差异有极显著性意义(P<0,01).结论:Haller指数、胸骨凹陷深度和心脏旋转角是评价漏斗胸病情的重要CT指标.%Objective:To evaluate the value of Haller index,the sternal depression,and the cardiac rotation angle in petus excavatum on the basis of the pre-and postoperative spiral CT features. Methods;Chest CT images in 70 cases of pec tus excavatum performed from 2003-01 to 2010-07 were retrospectively analyzed. The Haller index was the ratio of the maximal internal transverse diameter of the chest and the minimal anteroposterior diameter of the chest at the same level. The depth of sternal depression was measured on axial CT images of the chest. The cardiac rotation angle was defined as the angle between the longitudinal prevertebral line and the line from the cardiac apex to the prevertebral line. Comparative a nalysis was carried out for the pre-and postoperative Haller index,cardiac rotation angles,and sternal depression with those of control group. AP value less than 0. 05

  8. Dynamic cone beam CT angiography of carotid and cerebral arteries using canine model

    Energy Technology Data Exchange (ETDEWEB)

    Cai Weixing; Zhao Binghui; Conover, David; Liu Jiangkun; Ning Ruola [Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States); Department of Radiology, Shanghai 6th People' s Hospital, 600 Yishan Road, Xuhui, Shanghai (China); Koning Corporation, Lennox Tech Enterprise Center, 150 Lucius Gordon Drive Suite 112, West Henrietta, New York 14586 (United States); Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States); Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States) and Koning Corporation, Lennox Tech Enterprise Center, 150 Lucius Gordon Drive Suite 112, West Henrietta, New York 14586 (United States)

    2012-01-15

    Purpose: This research is designed to develop and evaluate a flat-panel detector-based dynamic cone beam CT system for dynamic angiography imaging, which is able to provide both dynamic functional information and dynamic anatomic information from one multirevolution cone beam CT scan. Methods: A dynamic cone beam CT scan acquired projections over four revolutions within a time window of 40 s after contrast agent injection through a femoral vein to cover the entire wash-in and wash-out phases. A dynamic cone beam CT reconstruction algorithm was utilized and a novel recovery method was developed to correct the time-enhancement curve of contrast flow. From the same data set, both projection-based subtraction and reconstruction-based subtraction approaches were utilized and compared to remove the background tissues and visualize the 3D vascular structure to provide the dynamic anatomic information. Results: Through computer simulations, the new recovery algorithm for dynamic time-enhancement curves was optimized and showed excellent accuracy to recover the actual contrast flow. Canine model experiments also indicated that the recovered time-enhancement curves from dynamic cone beam CT imaging agreed well with that of an IV-digital subtraction angiography (DSA) study. The dynamic vascular structures reconstructed using both projection-based subtraction and reconstruction-based subtraction were almost identical as the differences between them were comparable to the background noise level. At the enhancement peak, all the major carotid and cerebral arteries and the Circle of Willis could be clearly observed. Conclusions: The proposed dynamic cone beam CT approach can accurately recover the actual contrast flow, and dynamic anatomic imaging can be obtained with high isotropic 3D resolution. This approach is promising for diagnosis and treatment planning of vascular diseases and strokes.

  9. Contrast-enhanced helical CT in sigmoid diverticulitis. Findings and impact on diagnosis and treatment; Ruolo della tomografia computerizzata spirale nella diverticolite del sigma e implicazioni diagnostico-terapeutiche

    Energy Technology Data Exchange (ETDEWEB)

    Scaglione, M.; Romano, L.; Pinto, A.; De Lutio di Castelguidone, E.; Giovine, S.; Pinto, F. [Azienda Ospedaliera di Rilievo Nazionale A. Cardarelli, Naples (Italy). Dipt. di Diagnostica per Immagini; Forner, A.L. [Azienda Ospedaliera di Rilievo Nazionale A. Cardarelli, Naples (Italy). Dipt. di Chirurgia d' Urgenza; Grassi, R. [Naples Univ. II, Naples (Italy). Ist. di Radiologia

    2000-03-01

    Aim of this retrospective study was to assess the capability of contrast-enhanced helical computerised tomography (CT) in sigmoid diverticulitis, especially relative to selection of the appropriate treatment. The findings of 41 patients were reviewed from 1998 to 1999 June. Contrast-enhanced helical CT is the imaging modality of choice in assessing mild or severe acute diverticulitis because it provides useful information for appropriate treatment planning in the emergency setting. This technique is most useful in questionable cases and in patients with suspected severe diverticulitis where a choice must be made between different treatment options. [Italian] Scopo di questo studio retrospettivo e' illustrare i molteplici aspetti radiologici della flogosi diverticolare sigmoidea con tomografia computerizzata (TC) spirale, con specifico riguardo alle implicazioni terapeutiche che scaturiscono dall'analisi e dal confronto dei reperti TC con i riscontri clinici e chirurgici. Sono analizzati e discussi i risultati dello studio di 41 pazienti consecutivi con diverticolite del sigma esaminati dal giugno del 1998 al giugno del 1999. La TC spirale ha fornito dettagli precisi sul danno anatomo-chirurgico dell'ansa e sulle strutture limitrofe coinvolte consentendo di differenziare la diverticolite lieve da quella grave. Il suo ruolo si configura nei pazienti critici difficilmente classificabili e nelle sospette diverticoliti gravi o complicate per la molteplicita' delle scelte terapeutiche.

  10. Correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in maliagnant solitary pulmonary nodules and tumor size

    Directory of Open Access Journals (Sweden)

    Chenshi ZHANG

    2008-02-01

    Full Text Available Background and Objective The solitary pulmonary nodules (SPNs is one of the most common findings on chest radiographs. It becomes possible to provide more accurately quantitative information about blood flow patterns of solitary pulmonary nodules (SPNs with multi-slice spiral computed tomography (MSCT. The aim of this study is to evaluate the correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in maliagnant solitary pulmonary nodules and tumor size. Methods 68 patients with maliagnant solitary pulmonary nodules (SPNs (diameter <=4 cmunderwent multi-location dynamic contrast material-enhanced (nonionic contrast material was administrated via the antecubital vein at a rate of 4mL/s by an autoinjector, 4*5mm or 4*2.5mm scanning mode with stable table were performed. serial CT. Precontrast and postcontrast attenuation on every scan was recorded. Perfusion (PSPN, peak height (PHSPNratio of peak height of the SPN to that of the aorta (SPN-to-A ratioand mean transit time(MTT were calculated. The correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in maliagnant solitary pulmonary nodules and tumor size were assessed by means of linear regression analysis. Results No significant correlations were found between the tumor size and each of the peak height (PHSPN ratio of peak height of the SPN to that of the aorta (SPN-to-A ratio perfusion(PSPNand mean transit time (r=0.18, P=0.14; r=0.20,P=0.09; r=0.01, P=0.95; r=0.01, P=0.93. Conclusion No significant correlation is found between the tumor size and each of the quantifiable parameters of blood flow pattern derived with dynamic CT in maliagnant solitary pulmonary nodules.

  11. 螺旋CT三维重建在上颈椎损伤的诊断中的作用分析%Clinical Observation of Spiral CT Three-dimensional Reconstruction in Diagnosis of Upper Cervical Spine Injury

    Institute of Scientific and Technical Information of China (English)

    莫增媚

    2014-01-01

    Objective:To investigate clinical application value of spiral CT three-dimensional reconstruction in diagnosis of upper cervical spine injury. Method:18 cases of patients with cervical spine injury on X-ray and spiral CT images in our hospital from January 2010 to April 2013 were reviewed.The value of spiral CT three-dimensional reconstruction in diagnosis of upper cervical spine injury were analysed.Result:18 patients,fracture spiral CT findings of 20 parts:2 cases of atlas burst fracture,12 cases of odontoid fractures,2 cases of atlantoaxial vertebral fractures,4 cases of atlantoaxial arch fracture;4 cases of found dislocation:1 case of atlanto-occipital dislocation,3 cases of atlantoaxial dislocation.X-ray examination revealed the fracture site of 12 parts:1 case of fracture of the atlas,7 cases of odontoid fracture,2 cases of atlantoaxial vertebral fractures,2 cases of atlantoaxial arch fracture,misdiagnosis rate of 40%;2 cases of found dislocation:2 cases of atlantoaxial dislocation,misdiagnosis rate of 50%;Including 4 cases of atlantoaxial fractures misdiagnosed as atlantoaxial dislocation. Conclusion:Anatomy of the upper cervical spine because of its complex and subtle,upper cervical spine injury combined with three-dimensional reconstruction of spiral CT scans,can be clearly demonstrated upper cervical spine fracture,dislocation and secondary spinal stenosis,etc.Contribute to the clinical development of treatment programs timely and accurate.%目的:探讨分析螺旋CT三维重建在上颈椎损伤诊断中的作用和应用价值。方法:回顾性分析2010年1月-2013年4月在笔者所在医院进行诊治的18例上颈椎损伤患者的X线平片及螺旋CT三维重建图像,评价螺旋CT三维重建在上颈椎损伤诊断中的作用。结果:本研究18例患者中,螺旋CT三维重建发现骨折共20个部位:寰椎爆裂性骨折2例,枢椎齿状突骨折12例,枢椎椎体骨折2例,枢椎椎弓骨折4例;发现脱位共4

  12. Diagnostic Significance of Lumbar Spine Bone Metastases by 64 Slice Spiral CT and Whole Body Bone Imaging%64层螺旋CT与全身骨显像对腰椎骨转移瘤的诊断意义

    Institute of Scientific and Technical Information of China (English)

    宋世祥

    2014-01-01

    目的:探讨64层螺旋CT与99Tcm-MDP全身骨显像对腰椎骨转移瘤的诊断意义。方法回顾性分析临床确诊腰椎骨转移瘤且资料完整的住院诊治27例患者49处腰椎骨转移瘤,总结分析27例患者的64层螺旋CT与99Tcm-MDP全身骨显像检查结果。比较两种检查结果的灵敏度及特异性。结果经64层螺旋CT检查示,27例患者有41处腰椎锥体破坏;经99Tcm-MDP全身骨显像检查示,23例患者有31处腰椎椎体放射性异常浓集,27例患者发现椎体外多发放射性异常浓集。64层螺旋CT检查的灵敏度为83.6%,特异性为98.6%;99Tcm-MDP全身骨显像检查的灵敏度为63.2%,特异性为96.7%。经64层螺旋CT检查示,有17例明确诊断为腰椎转移瘤,10例可疑为腰椎转移瘤;经99Tcm-MDP全身骨显像检查示,有20例明确诊断为腰椎转移瘤,7例可疑为腰椎转移瘤。结论64层螺旋CT对腰椎骨转移瘤的诊断较99Tcm-MDP全身骨显像具有更高的灵敏度,但多数患者经99Tcm-MDP全身骨显像可获得较为明确的诊断。%Objective To investigate the diagnostic significance of lumbar spine bone metastases by 64 slice spiral CT and 99Tcm-MDP whole body bone imaging. Methods 27 cases of lumbar spine bone metastases with 49 places by clinical diagnosis and with complete hospitalization data were retrospectively analyzed, and the examination results of 27 cases with 64 slice spiral CT and 99Tcm-MDP whole body bone imaging were summarized and analyzed. The sensitivity and specificity of two kinds of examination results were compared. Results The examination result of 64 slice spiral CT showed that 41 vertebrae were damaged in 27 patients, the sensitivity was 83.6%, 17 cases of lumbar spine bone metastases were confirmed by 64 slice spiral CT, 10 patients were suspected. The examination result of 99Tcm-MDP whole body bone imaging showed that 31 vertebrae had radioactive anomaly concentration in 27 patients, the

  13. Spiraling Down into Corruption: A Dynamic Analysis of the Social Identity Processes that Cause Corruption in Organizations to Grow

    NARCIS (Netherlands)

    N.A. den Nieuwenboer (Niki); S.P. Kaptein (Muel)

    2007-01-01

    textabstractTo date, theory and research on corruption in organizations have primarily focused on its static antecedents. This paper focuses on the spread and growth of corruption in organizations. For this purpose three downward organizational spirals are formulated: the spiral of divergent norms,

  14. Flow dynamics of a spiral-groove dry-gas seal

    Science.gov (United States)

    Wang, Bing; Zhang, Huiqiang; Cao, Hongjun

    2013-01-01

    The dry-gas seal has been widely used in different industries. With increased spin speed of the rotator shaft, turbulence occurs in the gas film between the stator and rotor seal faces. For the micro-scale flow in the gas film and grooves, turbulence can change the pressure distribution of the gas film. Hence, the seal performance is influenced. However, turbulence effects and methods for their evaluation are not considered in the existing industrial designs of dry-gas seal. The present paper numerically obtains the turbulent flow fields of a spiral-groove dry-gas seal to analyze turbulence effects on seal performance. The direct numerical simulation (DNS) and Reynolds-averaged Navier-Stokes (RANS) methods are utilized to predict the velocity field properties in the grooves and gas film. The key performance parameter, open force, is obtained by integrating the pressure distribution, and the obtained result is in good agreement with the experimental data of other researchers. Very large velocity gradients are found in the sealing gas film because of the geometrical effects of the grooves. Considering turbulence effects, the calculation results show that both the gas film pressure and open force decrease. The RANS method underestimates the performance, compared with the DNS. The solution of the conventional Reynolds lubrication equation without turbulence effects suffers from significant calculation errors and a small application scope. The present study helps elucidate the physical mechanism of the hydrodynamic effects of grooves for improving and optimizing the industrial design or seal face pattern of a dry-gas seal.

  15. Embracing the Spiral

    Directory of Open Access Journals (Sweden)

    Li Mao

    2016-12-01

    Full Text Available Critical research demands that we interrogate our own positionality and social location. Critical reflexivity is a form of researcher critical consciousness that is constant and dynamic in a complex spiral-like process starting within our own experiences as racialized, gendered, and classed beings embedded in particular sociopolitical contexts. Across diverse critical methodologies, a group of graduate students and their supervisor explored their own conceptualization of the reflexivity spiral by reflecting on how their research motivations and methodologies emerged from their racializing, colonizing, language-learning, parenting, and identity negotiating experiences. In this article, they present a spiral model of the critical reflexivity process, review the literature on reflexivity, and conclude with a description of critical reflexivity as a social practice within a supportive and collaborative graduate school experience.

  16. 螺旋CT及X线平片在腕骨隐匿性骨折诊断中的比较分析%Spiral CT and X-ray plain film in the diagnosis of carpal bone occult fracture

    Institute of Scientific and Technical Information of China (English)

    宋春华

    2015-01-01

    Objective To study the carpal bone occult fracture characteristics of spiral CT and X-ray plain film. Methods A retrospective analysis of 46 carpal bone occult fracture cases X-ray films, CT data. Including the review of the data. Results X-ray, suspicious 19 cases of fracture and CT examination all positive, typically characterized by bone cortex lifted, interruption of trabecular bone. Conclusion CT has important significance in avoiding misdiagnosis and carpal bone occult fracture.%目的 探讨螺旋CT及X线平片在腕骨隐匿性骨折检查中的特点.方法 回顾性分析46例腕骨隐匿性骨折的X线片、CT资料. 结果 X线检查阳性1例, 可疑骨折19例,CT阳性后复核X线阳性2例,CT检查44例阳性,典型表现为骨皮质掀起,骨小梁中断.结论 CT检查在避免腕骨隐匿性骨折漏诊中有重要作用,CT阴性应引起重视.

  17. 多层螺旋CT在胆石性肠梗阻诊断中的价值%The value of multi-slice spiral CT in the diagnosis of gallstoneileus.

    Institute of Scientific and Technical Information of China (English)

    王兴龙; 李春荣

    2014-01-01

    目的:探讨多层螺旋CT在胆石性肠梗阻诊断中的价值。方法随机选取经过临床证实患有胆石性肠梗阻的患者16例,并对其临床资料进行分析。所有患者均接受了腹部超声和X先腹部平片以及CT平扫检查。结果16例患者多层螺旋CT均表现出胆石性肠梗阻征象。多层螺旋CT有100%的临床诊断准确率。结论多层螺旋CT对胆石性肠梗阻诊断中有极其重要的价值。%Objective To explore the multislice CT value in the diagnosis of gallstone ileus. Methods Randomly selected through clinical confirmed 16 cases of patients with gallstone ileus, and their clinical data were analyzed. All patients were accepted ab-dominal ultrasound and X first abdominal plain film and CT scan. Results MDCT results of 16 patients showed signs of gallstone ileus. Conclusion Multislice CT clinical diagnostic accuracy rate of 100%. Multi slice spiral CT has very important value in the diagnosis of gallstone ileus.

  18. 64层螺旋CT血管成像在自发性蛛网膜下腔出血中的应用价值%Application value of 64 slice spiral CT angiography in spontaneous subarachnoid hemorrhage

    Institute of Scientific and Technical Information of China (English)

    白光宇

    2016-01-01

    目的:总结、探讨64层螺旋CT血管成像在自发性蛛网膜下腔出血诊断中的应用价值。方法:收治自发性蛛网膜下腔出血患者110例,给予64层螺旋CT扫描及数字减影血管造影,再以容积再现、曲面重组、最大密度投影、多平面重组等方法处理。结果:110例 ASH 患者均经过 DSA、手术证实。动脉瘤及脑血管畸形105例,检出率95.45%,CTA 诊断符合率达100.00%。结论:64层螺旋 CT 血管成像在自发性蛛网膜下腔出血诊断中应用价值极高,可为临床疾病诊断、治疗提供有效依据。%Objective:To summarize and discuss the value of 64 slice spiral CT angiography in the diagnosis of spontaneous subarachnoid hemorrhage.Methods:110 patients with spontaneous subarachnoid hemorrhage were selected.64 slice spiral CT scanning and digital subtraction angiography were given,and then the volume rendering,surface reconstruction,maximum density projection,multi planar reconstruction and other methods were given.Results:110 cases of ASH were confirmed by DSA and operation.aneurysm and cerebral vascular malformation were 105 cases,the detection rate was 95.45% ,and the rate of CTA diagnosis was 100%.Conclusion:64 slice spiral CT angiography in the diagnosis of spontaneous subarachnoid hemorrhage is very high value.It can provide an effective basis for clinical diagnosis and treatment.

  19. 基于螺旋CT扫描图像的人牙齿的计算机三维重建%Three-dimensional Rebuilding of Human Tooth Based on the Digital Images by Spiral CT

    Institute of Scientific and Technical Information of China (English)

    郭宁山; 冯晓刚; 王乐

    2011-01-01

    目的:研究基于螺旋CT扫描图像的人牙齿的计算机三维重建.方法:采用美国PQ6000型螺旋CT扫描机,自下颌颏部下缘开始至鼻骨底做连续横断超薄扫描,得到了人牙齿的二维CT图像.应用图像处理与识别合成软件,读取二维CT图像数据文件,通过灰度分割方法对二维图像进行边缘提取,再利用三维表面重建算法对所截取的二维CT图像进行三维重建,最终获得人牙齿的三维重建影像.结果:获得的人牙齿三维重建影像,细致逼真、可被任意旋转、剖开、透视、截取,从不同角度观察重建影像形态还原性良好、重建效果满意.结论:基于螺旋CT扫描图像的人牙齿的计算机三维重建,可为有限元实体建模提供快捷、方便的方法.%Objective: To study the rebuilding method of human tooth based on the digital images by spiral CT.Methods: By the PQ6000 spiral CT, successive cross-sectional scanning was made from the inferior edge of the mandibular chin to the bottom of the nasal bone to obtain the two-dimensional digital images.Using the image processing and recognition software,two-dimensional CT image data file was established.Two-dimensional gray image segmentation method was adopted for edge detection.Further, three-dimensional surface reconstruction algorithm was used for the three-dimensional reconstruction by intercepted two-dimensional image.Results: Three-dimensional image of human tooth was obtained, which was rather vivid in every detail, and could be rotated, dissected, perspeeted, and intercepted optionally.It made the observation of images from different angles as possible.The reconstruction showed satisfactory replicating effects.Conclusions: Three-dimensional reconstruction of the human tooth by digital scanning of spiral CT can provide us a convenient and fast method for finite element model establishment.

  20. 256层螺旋CT在诊断椎体骨折中的应用价值%The Application Value of 256 Slice Spiral CT in the Diagnosis of Vertebral Fracture

    Institute of Scientific and Technical Information of China (English)

    田春阁

    2015-01-01

    目的:探讨256层螺旋CT在椎体疾病诊断中的临床应用价值。方法对临床怀疑或X线平片诊断椎体外伤及肿瘤所致病理性椎体骨骨折患者进行256层螺旋CT扫描检查,所得图像进行三维及多平面重建技术分析,结果与X线平片比较。结果85例中总椎体骨折数为121个,其中颈椎椎体骨折12个,胸椎椎体骨折56个,腰椎椎体骨折59个,骶尾椎椎体骨折19个。通过对照比较与统计分析。结论是256层螺旋CT对椎体骨折的检出率、诊断符合率明显高于X线平片,是椎体外伤及病理性椎体骨折中疑难鉴别诊断的首选检查方法。%Vertebral fractures often occur in the trauma, the preferred check method for the common X-ray photography, because it has the advantages of fast, and cheap. But vertebral physiological form belongs to irregular complex bone and soft tissue, often increases the missed diagnosis of vertebral fractures. 256 layer of the application of spiral CT, with its extreme-ly fast scanning speed and advantages of post-processing function, improve the diagnosis accuracy of vertebral fractures. This paper summarizes the 85 exception injury and pathological vertebral fracture patients 256 layer spiral CT examination and contrast analyzing X-ray photography, is to investigate 256 layer value of spiral CT in the diagnosis of vertebral frac-tures.

  1. 经胃镜胃黏膜下注射64排螺旋CT胃周淋巴结造影初探%Lymphatic Drainage from Gastric Tract:Preliminary Investigating Feasibility of Endoscopic 64-row Spiral CT Lymphography

    Institute of Scientific and Technical Information of China (English)

    朱建兵; 陈光强; 李勇; 朱江涛; 张伟; 龚建平

    2012-01-01

    目的 初步探讨胃黏膜下注射64排螺旋CT胃周淋巴结造影的应用价值.方法 征集21例志愿患者,进行胃镜下胃黏膜下造影剂注射,然后进行64排螺旋CT扫描.结果 16例患者均在完成64排螺旋CT的扫描获得相应图像.CT图像显示5例患者可见肝脏及血管旁线性致密影呈现;14例非胃癌患者仅8例发现可辨别的淋巴结影,其中2例患者发现胃周淋巴结密度增高.结论 胃镜辅助下64排螺旋CT胃周淋巴结造影作为一种潜在的术前淋巴结造影的选择具有一定优越性,但是应用于临床需要进一步的研究.%Objective To investigate feasibility of endoscopic 64-row spiral CT lymphography of the gastric tract preliminarily.Methods With institutional committee approval,a total of 2mL of undiluted iopamidol was injected into the gastric submucosa by endoscope in 21 volunteer patients,then scanning with 64-row spiral CT. Result 16 patients completed CT scan and got the imaging needed;5 patients were found the line high attenuation nearby liver and vascular;8 of the 14 patients were found lymphatic nodes identified;2 patients were found high attenuation lymphatic nodes nearby stomach.Conclusion Endoscopic 64-row spiral CT lymphography of stomach as a potentially lymphography of the stomach,still needs more investigation for clinic application.

  2. Diagnostic Value of 16-slice spiral CT in Sigmoid colon Volvulus%16层螺旋CT在乙状结肠扭转中的诊断价值

    Institute of Scientific and Technical Information of China (English)

    钟晖; 秦旭惠; 王莹

    2012-01-01

      Objective ::To explore the diagnostic value of 16-slice spiral CT conventional scan and its multi-planar reformation(MPR) in sigmoid colon volvulus.. Methods:retrospectively analysed the outcome of 12 case of sigmoid colon Volvulus patients who were diagnosed by 16-slice spiral CT conventional scan and its MPR and proved by clinical operations . Results: Multi-slice CT(MSCT) features of 12 case. including:volvulus with intestinal expanded 、fluid and pneumotosis、 with shapes of U-shaped or capsule strips 12 cases. Whirl pool of intestine and mesenteric whirlpool sign 9 cases 、 Cross sign 7 cases 、Beak sign 12 cases. Abdominal fluid 6 cases. Conclusion:: MSCT conventional scan can quickly show the location degree lesion morphological characterstic of intestinal volvulus ,with or without hemody namic images impairment of bouel wal. 16-slice spiral CT conventional scan and its (MPR) have important value to diagnose sigmoid colon volvulus .%  目的探讨16层螺旋CT在乙状结肠扭转中的诊断价值。方法对经16层螺旋CT平扫及多平面重组(MPR)诊断的12例乙状结肠扭转患者,结合其临床和手术结果进行回顾性分析。结果 CT主要表现有:扭转的肠袢扩张积液积气,呈马蹄形或囊袋状形12例;肠管及系膜漩涡征9例;交叉征7例;鸟喙征12例;腹水6例。结论多层螺旋CT平扫结合MPR能快速显示乙状结肠扭转的部位、程度、形态特征、有无血运障碍等,是诊断乙状结肠扭转非常有价值的检查方法。

  3. Investigating the role of SPECT/CT in dynamic sentinel lymph node biopsy for penile cancers

    Energy Technology Data Exchange (ETDEWEB)

    Saad, Ziauddin Zia; Bomanji, Jamshed [University College Hospitals London, Department of Nuclear Medicine, London (United Kingdom); UCLH NHS Foundation Trust, Institute of Nuclear Medicine, 5th Floor, London (United Kingdom); Omorphos, Savvas; Malone, Peter; Nigam, Raj; Muneer, Asif [University College Hospitals London, Department of Urology, London (United Kingdom); Michopoulou, Sofia; Gacinovic, Svetislav [University College Hospitals London, Department of Nuclear Medicine, London (United Kingdom)

    2017-07-15

    Currently, most centres use 2-D planar lymphoscintigraphy when performing dynamic sentinel lymph node biopsy in penile cancer patients with clinically impalpable inguinal nodes. This study aimed to investigate the role of SPECT/CT following 2-D planar lymphoscintigraphy (dynamic and static) in the detection and localization of sentinel lymph nodes in the groin. A qualitative (visual) review was performed on planar followed by SPECT/CT lymphoscintigraphy in 115 consecutive patients (age 28-86 years) who underwent injection of {sup 99m}Tc-nanocolloid followed by immediate acquisition of dynamic (20 min) and early static scans (5 min) initially and further delayed static (5 min) images at 120 min followed by SPECT/CT imaging. The lymph nodes detected in each groin on planar lymphoscintigraphy and SPECT/CT were compared. A total of 440 and 467 nodes were identified on planar scintigraphy and SPECT/CT, respectively. Overall, SPECT/CT confirmed the findings of planar imaging in 28/115 cases (24%). In the remaining 87 cases (76%), gross discrepancies were observed between planar and SPECT/CT images. SPECT/CT identified 17 instances of skin contamination (16 patients, 13%) and 36 instances of in-transit lymphatic tract activity (24 patients, 20%) that had been interpreted as tracer-avid lymph nodes on planar imaging. In addition, SPECT/CT identified 53 tracer-avid nodes in 48 patients (42%) that were not visualized on planar imaging and led to reclassification of the drainage basins (pelvic/inguinal) of 27 tracer-avid nodes. The addition of SPECT/CT improved the rate of detection of true tracer-avid lymph nodes and delineated their precise (3-D) anatomic localization in drainage basins. (orig.)

  4. 16排螺旋 CT 扫描并 MPR 在孤立性肺结节影像诊断中的价值%The diagnostic value of using 16-slice spiral CT scan and MPR on solitary pulmonary nodules

    Institute of Scientific and Technical Information of China (English)

    李权灵

    2015-01-01

    Objective To evaluate the diagnostic value of using 16-slice spiral CT scan and Multi-planar re-construction(MPR) on solitary pulmonary nodules(SPN).Methods 21 patients with small peripheral lung cancer and 29 patients with benign SPN were confirmed by pathology and analyzed retrospectively using CT imaging data .All patients underwent 16-slice spiral CT volume scanning and MPR .Results MPR images could display more special features of lesions than conventional transverse scanning , such as pleural indentation , vascular bundle , small calcifi-cation, spicule sign, vacuole sign, spinous protuberance etc .Conclusion 16-slice spiral CT scan and MPR shows more signs of SPN than conventional transverse scanning .It is valuable to use this technique to scan SPN and distin-guish between benign and malignant lung tumors .%目的:探讨16排螺旋CT扫描并多平面重建( MPR )在孤立性肺结节( SPN )影像诊断中的价值。方法回顾性分析经病理证实的周围型小肺癌21例和良性SPN 29例的CT影像资料,所有患者均行16排螺旋CT容积扫描并MPR。结果 MPR图像比常规横断位扫描更能显示病灶的特殊征象,如胸膜凹陷、血管集束、小钙化、毛刺征、空泡征、棘状突起等。结论16排螺旋CT扫描并MPR发现SPN的特殊征象更多,对区分SPN的良恶性具有重要价值。

  5. Static and dynamic CT imaging of the cervical spine in patients with rheumatoid arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Soederman, Tomas; Shalabi, Adel; Sundin, Anders [Uppsala University Hospital, Department of Radiology, Uppsala (Sweden); Olerud, Claes; Alavi, Kamran [Uppsala University Hospital, Department of Orthopedic Surgery, Uppsala (Sweden)

    2014-09-18

    To compare CR with CT (static and dynamic) to evaluate upper spine instability and to determine if CT in flexion adds value compared to MR imaging in neutral position to assess compression of the subarachnoid space and of the spinal cord. Twenty-one consecutive patients with atlantoaxial subluxation due to rheumatoid arthritis planned for atlantoaxial fusion were included. CT and MRI were performed with the neck in the neutral position and CT also in flexion. CR in neutral position and flexion were obtained in all patients except for one subject who underwent examination in flexion and extension. CR and CT measurements of atlantoaxial subluxation correlated but were larger by CR than CT in flexion, however, the degree of vertical dislocation was similar with both techniques irrespective of the position of the neck. Cervical motion was larger at CR than at CT. The spinal cord compression was significantly worse at CT obtained in the flexed position as compared to MR imaging in the neutral position. Functional CR remains the primary imaging method but CT in the flexed position might be useful in the preoperative imaging work-up, as subarachnoid space involvement may be an indicator for the development of neurologic dysfunction. (orig.)

  6. 64排螺旋CT诊断成人门静脉海绵样变性的影像学表现及价值%Imaging Findings and Value of 64-slice Spiral CT in Diagnosis of Cavernous Transformation of Portal Vein

    Institute of Scientific and Technical Information of China (English)

    施健; 施小平; 王强; 王勤英

    2012-01-01

    目的 探讨利用64排螺旋CT动态增强扫描技术及多种血管重建方法诊断门静脉海绵样变性(Cavernous transformation of portal vein,CTPV)的价值和意义.方法 10例经手术、数字血管造影、超声诊断证实的门静脉海绵样变性病例,均行腹部平扫和动态增强扫描及血管后处理成像.结果 门静脉海绵样变性主要表现为门脉主干和(或)分支的阻塞,门脉走行区正常结构消失,出现大量向肝性及离肝性侧枝静脉.通过VR、MIP、MPR等血管成像技术能很好的显示门静脉栓塞、侧枝血管的重建与开放情况.结论 64排螺旋CT动态增强扫描及血管成像技术对诊断门静脉海绵样变性及侧枝血管的显示有较大优势和意义.%Objective To evaluate 64-slice spiral CT dynamic contrast-enhanced scanning combined with angiography reconstruction techniques in diagnosis of cavernous transformation of portal vein (CTPV). Methods 10 patients with CTPV conformed by surgery, digital angiography and ultrasound underwent plain and dynamic contrast enhanced CT. Multiple angiography reconstruction techniques were used to obtain vascular post-processing images. Results CTPV was primarily characteristic of the portal vein and (or) branch obstruction, loss of normal structure of portal vein region, presence of abundant venous collaterals through and out of liver. Volume rendering view (VR), maximum intensity projection (MIP) and multiplanar reconstruction (MPR) could distinctly display the portal vein embolization as well as reconstruction and opening situation of collateral vessels. Conclusion 64-slice spiral CT dynamic contrast-enhanced scanning combined with angiography reconstruction techniques is capable of making an accurate diagnosis of CTPV and providing more information for clinical therapy decisions.

  7. Diagnostic Value of Multi-slice Spiral CT Multi-phase Scanning in Early Sage Renal Pelvis Cancer%多层螺旋CT多期扫描对早期肾盂癌的诊断价值

    Institute of Scientific and Technical Information of China (English)

    葛芳清; 韩希年

    2013-01-01

    目的 探讨多层螺旋CT多期扫描对早期肾盂癌的诊断价值.方法 回顾性分析5 8例肾盂癌的CT表现并进行CT分期,与组织病理学结果对照.结果 CT图像分期A期(早期)1 8例、B期3 2例、C期8例;病理分期早期(A期)24例、B期26例、C期8例.24例A期肾盂癌中,CT分期正确的1 7例,7例A期误判为B期,1例B期误判为A期.CT评判早期肾盂癌的敏感性70.8%(17/24),特异性97%(32/33),阳性预测值94.4% (17/18)%.结论 多层螺旋CT多期扫描对早期肾盂癌的判断有很高的特异性,对临床手术方案的选择起到很好的指导作用.%Objective To investigate the diagnostic value of enhanced multi-phase spiral CT in the early renal pelvis cancer.Methods CT manifestations of 58 cases with renal pelvis cancer were retrospectively analyzed and CT staged,and compared to its pathological results.Results CT image stage showed A stage (early stage) in 18 cases,B stage in 32 cases,C stage in 8 cases; pathological stage showed A stage (early stage) in 24 cases,B stage in 26 cases,C stage in 8 cases.Of all 24 cases with A stage renal pelvis cancer,17 cases were diagnosed correctly,and 7 cases with A stage cancer were misdiagnosed as B stage,and 1 case with B stage cancer misdiagnosed as A stage.The sensitivity,specificity,positive predictive value of CT stage in evaluation of early renal pelvis cancer were 70.8%(17/24),97% (32/33),and 94.4% (17/18) %.Conclusion Enhanced multi-phase spiral CT has high specificity in diagnosis of early stage renal pelvis cancer.It plays an important role in clinical operation scheme selection.

  8. Application of spiral CT examination in neonatal hypoxic-ischemic encephalopathy%螺旋CT检查在新生儿缺血缺氧性脑病中的应用

    Institute of Scientific and Technical Information of China (English)

    刘学荣; 贺杰

    2013-01-01

    目的探讨新生儿缺血缺氧性脑病(hypoxie-ischemic enceph-alopathy,HIE)的螺旋CT表现特点及其应用价值。方法回顾性分析60例HIE的CT表现,依据病灶范围观察轻度至重度HIE的CT表现特征。结果60例临床诊断为HIE的患者中54例有异常CT表现,6例未见异常。51例病变CT值在10~18HU之间,3例病变CT值在18~21HU之间。脑实质出血1例,蛛网膜下腔出血者4例。复查外部性脑积水4例,脑软化5例、脑萎缩1例。结论螺旋CT检查对HIE的诊断具有较高的准确性,可对临床的治疗及预后提供真实而客观的依据%Objective To investigate the spiral CT performance features of neonatal hypoxic-ischemic encephalopathy (HIE) and its application value. Methods The CT performance of 60 patients with HIE was analyzed retrospectively and the CT performance features of mild to severe HIE were observed according to the lesion range. Results Of the 60 patients clinically diagnosed with HIE, 54 patients had abnormal CT performance and 6 patients did not. Fifty-one patients had a CT value ranging from 18-21HU. Brain parenchyma bleeding was found in 1 patient and subarachnoid hemorrhage was found in 4 patients. Reexamination found external hydrocephalus in 4 patients, encephalomalacia in 5 patients and cerebral atrophy in 1 patient. Conclusion Spiral CT examination is accurate in the diagnosis of HIE and can provide true and objective basis for clinical treatment and prognosis.

  9. Analysis of clinical application of 16 slice spiral CT in diagnosis and treatment of gastrointestinal diseases%16排螺旋CT在胃肠道疾病诊治中的临床应用分析

    Institute of Scientific and Technical Information of China (English)

    黄伟康; 唐西平; 吴志彬; 李志铭

    2016-01-01

    目的:探讨16排螺旋CT在胃肠道疾病诊断中的临床价值。方法采集本院2014年1月至2015年1月入院经手术治疗的118例包括胃肠道穿孔、肠梗阻、小肠间质瘤、肠扭转、腹内疝、肠系膜血栓、急性阑尾炎、胃癌及其病灶浸润等情况的胃肠道常见病变患者的临床资料进行回顾性分析,118例患者均采用16排螺旋CT在容积扫描后分别进行多平面重建、表面阴影成像、透亮显示图像及CT仿真内窥镜等后处理进行影像诊断设为实验组,并都经过胃肠内镜进行检查对比设为对照组,并将2组的检查结果与手术病理结果进行比较和分析。结果经手术确诊,CT与胃肠内镜在胃肠道疾病检出率上都比较高,在胃肠道穿孔、小肠间质瘤、肠扭转、肠系膜血栓、病灶浸润转移的检出率方面16排螺旋CT较胃肠镜有显著优势,两者差异具有统计学意义(P<0.05);在肠梗阻、腹内疝、急性阑尾炎及胃癌方面的检出率方面差异无统计学意义(P>0.05)。结论16排螺旋CT全腹部扫描对胃肠道疾病的定位和定性诊断具有重要的临床价值。%Objective To investigate the clinical value of 16 slice spiral CT (MSCT) in the diagnosis of gastrointestinal diseases. Methods One hundred and eigteen cases were collected in our hospital from January 2014 to January 2015 after admission in patients with clinical data including gastrointestinal perforation , intestinal obstruction, intestinal stromal tumor, abdominal hernia, volvulus, mesenteric thrombosis, acute appendicitis, gastric cancer and tumor invasion of the gastrointestinal diseases operation in treatment of 118 cases were analyzed retrospectively. All cases were treated by the 16 row spiral CT multiplanar reconstruction, respectively in the volume scanning surface after shadow imaging, bright display images and CT virtual endoscopy and postprocessing for the experimental group for imaging

  10. Multislice spiral CT oral isotonic mannitol enterography%口服等渗甘露醇多层螺旋CT小肠造影体会

    Institute of Scientific and Technical Information of China (English)

    钟冠新; 陈汉棠; 麦冠光

    2014-01-01

    Objective To evaluate the multislice spiral CT(MSCT) oral isotonic mannitol enterography and intestinal diseases.Methods 80 patients with suspected small bowel disease by clinical examination from October 2013 to February 2014 were selected and received MSCT enterography,taking 2 000mL oral isotonic mannitol solution in 4 times during one hour before the examination and receiving muscle injection of 20 mg anisodamine before scan beginning 20 minutes.Multiplanar reconstruction(MPR) of the data obtained, the maximum intensity projection(MIP) and some key parts surface reconstruction could display of intestinal vascular and intestinal characteristics, summarize the imaging characteristic of small bowel disease .Results 80 patients were successfully completed scan.Results were evaluated as excellent in 67 cases(83.8%), good in 11 cases(13.8%), common in 2 cases(2.4%), poor in 0 cases. No adverse reaction occurred in all patients. 11 cases of duodenal adenocarcinoma were found in 80 patients, 9 cases of lymphoma, 6 cases of stromal tumor, 15 cases of leiomyoma, 25 cases of Crohn 's disease, 8 cases of duodenal chronic inflammation,and 6 cases were negative.The clinical diagnostic accordance rate was 100%.Conclusion It has important clinical significance and application value of MSCT oral isotonic mannitol enterography examination in the diagnosis of small bowel diseases.%目的:评价口服等渗甘露醇MSCT小肠造影对小肠疾病的诊断价值。方法选取2013年10月~2014年2月经临床检查怀疑小肠疾病的80例患者,均进行MSCT小肠造影检查,检查前1 h内分4次口服等渗甘露醇溶液2000 mL,扫描前20 min肌肉注射20 mg山莨菪碱。对所获资料进行多平面重建(MPR)、最大密度投影(MIP)及重点部位曲面重建,显示小肠血管及肠壁特点,总结小肠疾病的影像学特征。结果80例患者均顺利完成扫描,结果评定为优者67例(83.8%),良11例(13.8%),一般2例(2

  11. 64层螺旋CT冠状动脉成像影响因素分析%Analysis of Influential Factors of 64-slice Spiral CT Coronary Angiography

    Institute of Scientific and Technical Information of China (English)

    刘伟宾

    2011-01-01

    目的 探讨64层螺旋CT冠状动脉成像的质量影响因素.方法 回顾性分析514例行64层螺旋CT冠状动脉成像的影像资料.结果 根据图像评价方法,本组优321例,占62.5%;良138例,26.8%;差55例,占10.7%,认定为检查失败.127例ECG前瞻式门控扫描检查失败21例,占16.5%;387例回顾式门控扫描检查失败34例,占8.8%.检查时心率波动≤5/min 313例,7例失败,占2.2%;6~10/min 175例,23例检查失败,占13.1%;10~20/min 26例,25例检查失败,占96.2%.检查过程中37例屏气不好,32例检查失败,占86.5%;3例扫描过程中未能控制呛咳、呃逆,检查失败;53例冠状动脉搭桥术后复查者,1例因扫描范围不足而检查失败;3例过于肥胖,1例扫描参数过低而导致检查失败.结论 充分认识64层螺旋CT冠状动脉成像检查中影响成像质量的因素,争取患者最佳配合状态,方能获得更好的图像质量,提高诊断准确性.%Objective To discuss the influential factors of image quality of 64-slice spiral CT coronary angiography (CTCA). Methods The imaging data of 514 patients with coronary artery disease were retrospectively analyzed. Results According to image evaluation method, the results were excellent in 321 patients(62.5% ), good in 138 ( 26. 8% ) , and poor and regarded as failures in 55( 10.7% ). 127 patients underwent prospective electrocardiographic (ECG) gating, but failed in 21 patients (16.5%) ; 387 patients underwent retrospective ECG gating, and failed in 34 patients (8.8%). 313 patients had heart rate fluctuation ≤5 beats per minute( BPM), among whom, 7 (2.2%) failed in examination; 175 patients had heart rate from 6 BPM to 10 BPM, among whom, 23 (13.1%) failed in examination; 26 patients had heart rate from 10 BPM to 20 BPM,among whom, 25 failed in examination; 37 patients had poor breathholding, among whom, 32(86.5% )failed in examination.3 failed in examination due to incontrollable bucking and hiccup during the

  12. 螺旋CT多期扫描在肝小血管瘤与小肝癌诊断的临床应用%Clinical Application of More-phase Spiral CT in Small Hepatocellular Carcinoma and Small Hepatic Hemangioma

    Institute of Scientific and Technical Information of China (English)

    王海

    2001-01-01

    目的:探讨小肝细胞癌和肝脏小血管瘤螺旋CT增强表现及其随时间延迟所致的CT征象的变化过程。材料与方法:50例患者(15例SHCC,35例SHHE),其中19例经手术病理标本证实,其余由临床表现和实验室检查诊断。采用Siemens Plus4C螺旋CT机,先作平扫,然后在肿瘤靶平面平衡期扫描。着重观察、分析不同CT扫描时相小肝细胞癌和肝脏小血管瘤CT表现特征的动态变化过程。结果,SHHE组发现病灶44个,30个病灶在动脉期边缘明显强化逐渐向中心填充,22个病灶在动脉期和门静脉期均为高密度,2个病灶在动脉期和门静脉期均为低密度,在平衡期42个病灶SHHE为高密度和等密度;SHCC组发现病灶18个,14个病灶SHCC显示动脉期呈高密度、门静脉期为低密度,3个病灶动脉期为高密度、门静脉期为等密度,1个病灶动脉期、门静脉期均为低密度,平衡期16个病灶的SHCC为低密度。结论:根据SHHE和SHCC在螺旋CT多期扫描的强化表现,大多数病例可明确两者诊断。%Objective: To investigate the enhanced spiral CT features of SHCC and SHHE,and the changing of these features with time. Materials and Methods: Of 50 cases with SHCC(15/50)and SHHE (35/50), 19 cases were surgically and pathologically proved, and the others were clinically diagnosed. Plain scanning, single-level dynamic scanning of the target section during hepatic arterial phase (delaying 25-30 sec.), portal venous phase scanning(delaying 60-70 sec.)of the whole liver, and equilibrium scanning of the target section here performed. The dynamic changes of CT features were observed and analyzed. Results: 35 cases with SHHE were found in 44 focuses. Peripheral enhancement significantly of the lesion were found 30(30/44) focuses on the arterial phase scan and to fill up by degrees from the periphery of the lesion to center. Hemogenous enhancement was seen in 22(22/44) focuses and 2

  13. Experimental Study on Spiral Patterns in Dielectric Barrier Discharge System

    Institute of Scientific and Technical Information of China (English)

    LIU Shu-Hua; DONG Li-Fang; LIU Fu-Cheng; LI Shu-Feng; LI Xue-Chen; WANG Hong-Fang

    2006-01-01

    Spiral patterns are obtained in a dielectric barrier discharge system with water electrodes. The dynamics of spiral formation and transition is investigated. Wavelength characteristic of spiral patterns is also studied. Correlation measurements indicate that the wavelength of spiral pattern increases with the increasing gas gap width and oscillates with the increasing drive frequency.

  14. The dynamic correction of collimation errors of CT slicing pictures

    Institute of Scientific and Technical Information of China (English)

    LIU Ya-xiong; Sekou Sing-are; LI Di-chen; LU Bing-heng

    2006-01-01

    To eliminate the motion artifacts of CT images caused by patient motions and other related errors,two kinds of correctors (A type and U type) are proposed to monitor the scanning process and correct the motion artifacts of the original images via reverse geometrical transformation such as reverse scaling,moving,rotating and offsetting.The results confirm that the correction method with any of the correctors can improve the accuracy and reliability of CT images,which facilitates in eliminating or decreasing the motion artifacts and correcting other static errors and image processing errors.This provides a foundation for the 3D reconstruction and accurate fabrication of the customized implants.

  15. 多层螺旋CT对气管憩室诊断的价值%The value of multi-silice spiral CT in the diagnosis of tracheal diverticulum

    Institute of Scientific and Technical Information of China (English)

    张培贵; 邱乾德

    2015-01-01

    目的:探讨多层螺旋C T 对气管憩室诊断应用价值。方法回顾性分析经临床证实的气管憩室92例C T 表现。结果憩室大小0.3~3.5cm ,平均约1.2cm ,其中2.0cm以上19例。憩室形态不规则53例,类圆形17例,椭圆形14例,小泡状8例;憩室囊腔内呈分房样或蜂窝状改变并见嵴状、皱襞样结构或分隔线改变28例,憩室并发感染并见液平1例。结论多层螺旋CT对气管憩室诊断具有实用价值。%Objective To explore the value of multi‐detector spiral CT in diagnosis of tracheal diverticulum .Methods We colleced 92 cases of the tracheal diverticula by clinically proven and retrospectively reviewed their features of CT .Re‐sults The size of tracheal diverticulum ranged from 0 .3 to 3 .5 cm diameter ,with an average of about 1 .2 cm ,of which 19 cases were more than 2 .0 cm .53 cases of diverticula were irregular ,17 cases were round ,14 cases were oval ,8 cases were vesicular ;within the diverticulum‐like or honeycomb cysts ,housing allocation changes were shown and the ridge‐like ,fold‐like structures or changes were seen in 28 cases ,diverticulitis complicated by infection and the fluid level was seen in 1 case .Conclusion Multislice spiral CT has practical value for the diagnosis of tracheal diverticulum .

  16. 64层螺旋CT在消化道穿孔的诊断价值%The Value of 64 Slice Spiral CT in the Diagnosis of Digestive Tract Perforation

    Institute of Scientific and Technical Information of China (English)

    孙晓霞; 郭强强; 兰国宾; 路凯; 李宝栋; 郭福庆

    2015-01-01

    Objective:To investigate the value of 64-slice spiral CT in the diagnosis of digestive tract perforation.Method:A retrospective analysis was conducted in imaging information of 76 cases confirmed by surgery in patients with digestive tract perforation.Result:In the 76 patients,the main CT signs were peritoneal effusion,free gas,surrounding cellulites or peritonitis change around the perforation and gastrointestinal wall thickening. Preoperative diagnostic accuracy was 92.0%. The correct localization rate was 81.2%.Conclusion:64 slice spiral CT in gastrointestinal perforation can timely,accurate diagnosis. It also has high value in judging the digestive tract perforation location.%目的:探讨64层螺旋CT在消化道穿孔诊断中的价值。方法:回顾性分析76例经手术证实的消化道穿孔患者的影像资料。结果:76例患者中,CT主要征象为腹腔积液、游离气体、穿孔处周围蜂窝组织炎或腹膜炎改变、胃肠壁增厚,术前正确诊断穿孔92.0%,定位正确诊断81.2%。结论:64层螺旋CT用于消化道穿孔中能够及时、准确地作出诊断,在判断消化道穿孔位置具有较高的价值。

  17. Comparison of Image Quality and Radiation Dose between High-Pitch Mode and Low-Pitch Mode Spiral Chest CT in Small Uncooperative Children: The Effect of Respiratory Rate.

    Science.gov (United States)

    Kim, Seong Ho; Choi, Young Hun; Cho, Hyun-Hae; Lee, So Mi; Shin, Su-Mi; Cheon, Jung-Eun; Kim, Woo Sun; Kim, In-One

    2016-04-01

    To compare image quality and radiation dose between high-pitch mode (HPM) and low-pitch mode (LPM) CT in young children. Forty-seven children (mean age 35.6 months; range, 0-126 months) underwent 49 CT examinations in HPM or LPM and were divided into high or low respiratory rate (RR) groups. A qualitative image quality was compared between the two modes. The volume CT dose index (CTDIvol) and dose-length product (DLP) were evaluated from the dose reports, and effective doses were assessed using a paediatric phantom. Image quality was generally better for HPM than LPM (diagnostic acceptance score, 4.00 vs. 3.46, P = 0.004); the difference was more prominent in the high RR group (4.00 vs. 3.22, P = 0.001). However, there was no significant difference in the low RR group. The mean DLP value was higher in HPM than LPM (29.48 mGy · cm vs. 23.46 mGy · cm, P = 0.022), while CTDIvol was not significantly different. The total effective radiation dose was 26 % higher in HPM than LPM (1.82 mSv vs. 1.44 mSv). LPM can be considered for paediatric lung evaluation in young children with low RRs to reduce radiation dose while maintaining favourable image quality. • Radiation exposure is higher on high-pitch "Flash spiral mode" than on low-pitch "X-CARE mode". • "Flash spiral mode" generally showed better image quality than "X-CARE mode". • Difference in image quality was more prominent in the high RR group. • There was no difference in image quality in the low RR group. • "X-CARE mode" should be considered in a limited population with low RRs.

  18. Study on Enhancement Scanning Technology of 16-slice Spiral CT in Upper Abdomen%16排螺旋CT在上腹部增强扫描中的技术探讨

    Institute of Scientific and Technical Information of China (English)

    石银龙

    2011-01-01

    Objective To evaluate the value of 16-slice spiral CT enhancement scanning technology in the upper abdomen. Methods 200 patients were examined by CT in the upper abdomen. Contrast agent was injected through the hand vein at 1.5mL/kg, with pressure of 300 pounds, flow rate 2.5mL/s. Before injection, we must complete the first scanning. Then, other 2 or 3 scanning were done. Results 188 cases can show abdominal aorta, hepatic artery, splenic artery, hilar vessel branches, portal vein, inferior vena cava very well. The others were not ideal because of portal hypertension. Conclusion 1'6 -slice spiral CT enhancement scanning technology in the upper abdomen can obtain good images to meet clinical needs.%目的 探讨16排螺旋CT在上腹部增强扫描技术.方法 对200例患者进行上腹部CT扫描,造影剂按照1.5mL/kg,经手背静脉用高压注射器注射,其压力为300磅,流速2.5mL/s,注药前扫描1次,注药后不同时相扫描2~3次.结果 188例能很好地显示出腹主动脉、肝动脉、脾动脉、肝门区血管分支、门静脉、下腔静脉;10例因门脉高压导致造影结果不理想;2例失败.结论 16排螺旋CT的上腹部增强扫描可获得满意的图像以满足临床需要.

  19. Experimental demonstration of a dynamic bowtie for region-based CT fluence optimization

    Science.gov (United States)

    Robinson, Vance; Smith, Walt; Rui, Xue; Yin, Zhye; Wu, Mingye; Fitzgerald, Paul; De Man, Bruno

    2016-03-01

    Technology development in Computed Tomography (CT) is driven by clinical needs, for example the need for image quality sufficient for the clinical task, and the need to obtain the required image quality using the lowest possible radiation dose to the patient. One approach to manage dose without compromising image quality is to spatially vary the X-ray flux such that regions of high interest receive more radiation while regions of low interest or regions sensitive to radiation receive less dose. If the region of interest (ROI) is centered at the CT system's axis of rotation, a simple stationary bowtie mounted between the X-ray tube and the patient is sufficient to reduce the X-ray flux outside the central region. If the ROI is off center, then a dynamic bowtie that can track the ROI as the gantry rotates is preferred. We experimentally demonstrated the dynamic bowtie using a design that is relatively simple, low cost, requires no auxiliary power supply, and can be retrofitted to an existing clinical CT scanner. We installed our prototype dynamic bowtie on a clinical CT scanner, and we scanned a phantom with a pre-selected off-center ROI. The dynamic bowtie reduced the X-ray intensity outside the targeted ROI tenfold. As a result, the reconstructed image shows significantly lower noise within the dynamic bowtie ROI compared to regions outside it. Our preliminary results suggest that a dynamic bowtie could be an effective solution for further reducing CT radiation dose.

  20. Tracheomalacia in adults with cystic fibrosis: determination of prevalence and severity with dynamic cine CT.

    LENUS (Irish Health Repository)

    McDermott, Shaunagh

    2012-02-01

    PURPOSE: To determine the prevalence and severity of tracheomalacia in adults with cystic fibrosis (CF) by using dynamic cine multidetector computed tomography (CT) and to correlate these findings with pulmonary function test (PFT) results and the severity of parenchymal lung disease. MATERIALS AND METHODS: In this institutional review board-approved HIPAA-compliant study, 40 patients with CF (22 men, 18 women; mean age, 28 years +\\/- 8 [standard deviation]; age range, 18-54 years) prospectively underwent PFTs, standard thin-section CT, and two dynamic cine multidetector CT acquisitions. Ten control subjects underwent dynamic cine multidetector CT. After standard thin-section CT was completed, dynamic cine multidetector CT was performed during a forced expiratory maneuver and during coughing. Dynamic cine multidetector CT images in nine patients were excluded. Maximal inspiratory, dynamic expiratory, and end-expiratory tracheal luminal areas were compared (Student t test) and correlated (Spearman rank) with PFT results and severity of parenchymal lung disease. RESULTS: Mean predicted forced expiratory volume in 1 second (FEV(1)) was 70.6% +\\/- 20.7, and mean Bhalla CT score was 41.8% +\\/- 13.6. In patients with CF, dynamic cine mean tracheal cross-sectional area reduction was 51.7% +\\/- 18.4 (range, 9%-89%) for forced expiratory maneuvers and 68.8% +\\/- 11.7 (range, 18%-88%) for coughing (P = .001). Tracheomalacia was demonstrated in 24 (69%) patients and no control subjects during forced expiratory maneuvers (P = .001) and in 10 (29%) patients and one (10%) control subject during coughing. For end-expiration images, mean tracheal luminal reduction was 16.1% +\\/- 14.0% (range, 0.0%-53.0%), with one patient demonstrating tracheal luminal reduction of more than 50%. There was no correlation between tracheal cross-sectional luminal reduction and either predicted FEV(1) or CT Bhalla score. CONCLUSION: Tracheomalacia depicted at dynamic cine multidetector CT is a

  1. Spiraling attractors and quantum dynamics for a class of long-range magnetic fields

    DEFF Research Database (Denmark)

    Cornean, Horia; Herbst, Ira; Skibsted, Erik

    2007-01-01

    We consider the long time behavior of a quantum particle in a 2D magnetic field which is homogeneous of degree -1. If the field never vanishes, above a certain energy the associated classical dynamical system has a globally attracting periodic orbit in a reduced phase space. For that energy regim...

  2. Spiraling attractors and quantum dynamics for a class of long-range magnetic fields

    DEFF Research Database (Denmark)

    Cornean, Horia Decebal; Herbst, Ira; Skibsted, Erik

    We consider the long time behavior of a quantum particle in a 2-D magnetic field which is homogeneous of degree -1. If the field never vanishes, above a certain energy the associated classical dynamical system has a globally attracting periodic orbit in a reduced phase space. For that energy regi...

  3. Contrastive Research on the Reliability of 128-Slice Spiral CT in the Measurement of Normal Occlusion Model%128层螺旋CT在正常模型测量中的可靠性研究

    Institute of Scientific and Technical Information of China (English)

    常捷; 李武; 滕永健; 赵晶帆

    2014-01-01

    Objective To verify the reliability, repeatability and accuracy of 128-slice spiral CT through comparing the measurement results of 128-slice spiral CT of 20 normal chin models with those of traditional manual measurement results.Methods The volume scanning with its data collection of normal chin models were conducted with 128-slice spiral CT. Then the images whose slice thicknesses were 0.6 mm were obtained through function reconstruction and then were transferred to various softwares including the 3D workstation, Dental and Inspace. The related indicators including the teeth width, dental arch length and dental arch width of maxillary and mandibular teeth were measured with axial images, MPR (Multiplanar Reconstruction), CPR (Curve Planar Reconstruction) and VR (Volume Reconstruction) while these indicators were also measured with vernier caliper manually. The measurement data collected from those two methods were analyzed and compared.Results The parallel validity of manual measurement was similar to CT measurement whose measurement error was-0.02~0.02 mm.Conclusion 128-slice spiral CT can meet the clinical orthodontic requirements.%目的:通过对20副正常模型的128层螺旋CT测量结果与传统手工测量结果进行比较,验证128层螺旋CT系统的可靠性、可重复性、精确性。方法应用128层螺旋CT机对正常模型进行容积扫描、数据采集,并进行函数重建得到0.6 mm层厚图像,传送至配套3D工作站、Dental(齿科软件)、Inspace(4D无间断实时互动三维成像技术)等软件,利用轴位图像、MPR(多平面重建)、CPR (曲面重建)、VR(容积重建)等方法测量正常模型的上、下颌牙的牙齿宽度,牙弓长度、宽度等相关指标;同时用游标卡尺手工测量上述指标,将两种测量方法所得数据进行比较。结果两种测量方法具有相似的平行效度。CT系统的测量误差为-0.02~0.02 mm,精确度较高。结论128层

  4. 64排容积CT扫描在严重多发伤快速评估中的应用%Clinical application of 64-slice spiral CT scanning in fast evaluation of severe multiple trauma

    Institute of Scientific and Technical Information of China (English)

    熊坤林; 龚水根; 李然; 曹红元; 张伟国

    2008-01-01

    Objective To discuss clinical value of 64-slice spiral CT scanning in fast evaluation of severe multiple trauma.Methods A retrospective study was carried out on data of 72 multiple trauma patients diagnosed with systemic 64-slice spiral CT scanning in our hospital from January 2006 to June 2008.Of all,28 patients with traffic injuries,24 with falling injuries,10 with blunt injuries,6 with stab injuries and 4 with explosive injuries.Results There were 72 multiple trauma patients with mean scanning time of 10.2 seconds.The CT scanning showed both craniocerebral and thoracic injuries in 30 patients,brain injuries in 16,thoracoabdominal injuries plus pelvic injuries in 10,extremity and brain injuries in 14 and systemic soft tissue injuries in 2.Isotropic characteristics and postprocessing function of 64-slice spiral CT scanning could accurately diagnose and evaluate injury severity of multiple trauma.Conclusions 64-slice spiral CT scanning is a fast and effective method for fast evaluating injury severity of multiple trauma,for it can not only shorten checking time,reduce movements of the patients and relieve the pain of the patients,but also can avoid defects induced by respiratory movement and provide fairly integrated imaging materials by its isotropic characteristics and pestprecessing function.%目的 探讨64排容积CT扫描在严重多发伤快速评估中的临床价值.方法 回顾性分析我院2006年1月-2008年6月收治的72例严重多发伤患者.致伤原因:交通伤28例,坠落伤24例,钝器伤10例,刀刺伤6例,爆炸伤4例.根据患者当时受伤情况及可疑损伤部位均及时行全身64排容积CT扫描.结果 本组72例严重多发伤患者中,头、胸部均有损伤30例,头部损伤16例,胸腹盆部均有损伤10例,四肢及头部损伤14例,全身软组织损伤2例.平均扫描耗时约10.2 s.64排容积CT各向同性特点和强大的后处理功能使其能准确地对组织器官的损伤情况及损伤程度进行

  5. The spiral

    DEFF Research Database (Denmark)

    Bibace, Roger; Kharlamov, Nikita

    2013-01-01

    At the core of Heinz Werner’s concept of development is what he called “the genetic principle of spirality:” over the course of ontogenetic development, lower levels, processes, and functions do not disappear, and can even resurface again under specific conditions, normal and pathological. Werner...

  6. Usefulness of dynamic CT in the evaluation of percutaneous microwave coagulation therapy for liver cancer

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Naoki [Tottori Univ., Yonago (Japan). Faculty of Medicine

    1999-07-01

    This paper is concerned with effects of percutaneous microwave coagulation therapy (PMCT) and evaluation of PMCT by dynamic computed tomography (CT). Between January 1996 and March 1998, 23 patients with liver cancer were selected for this study. In 5 patients in the series, the extent of heating with irradiation at 60 Watts for 60 seconds was measured. In remaining 18 patients, PMCT was repeated till the hyperechogenic areas extended the whole target area on ultrasonography (US). Dynamic CT obtained one week after PMCT was compared with histological findings of the resected specimen that had been obtained 8 days after PMCT. The temperature rose over 60degC within 7.5 mm-area from the electrode. Each area coagulated by PMCT was shown as low density one both in early and delayed phase of dynamic CT. Accurate diagnoses whether undestroyed cancerous tissue was left or not were obtained by dynamic CT in 6 of 8 patients whose tumor was incompletely destroyed, and in all of 10 patients whose tumor was completely destroyed after PMCT. PMCT as a local treatment for liver cancer was considered to be a highly effective technique, because a certain area around punctured electrode fell into necrosis without exception. And dynamic CT was revealed to be a useful method for the patients with liver cancer to evaluate the effect of PMCT. (author)

  7. 多层螺旋CT MPR、MIP及VRT剖切技术在腰椎峡部裂中的应用%Multi Slice Spiral CTMPR,MIP and VRT Cutting Technique in the Application of Iumbar Spondylolysis

    Institute of Scientific and Technical Information of China (English)

    公维云

    2013-01-01

    Objective:To investigate the multi-slice spiral CT post-processing method MPR,MIP and VRT combined cutting technique in lumbar spondylolysis application effect. Method:From October to 2012 in our hospital in 2010 August included 87 cases of lumbar spondylolysis with multi-slice spiral CT,and took MPR,MIP and VRT processing,to observe the effect of the clinical diagnosis. Result:Through the comparative analysis, of which,MPR and MIP display rate was 100%,while the VRT cutting front display rate was 94%,VRT after cutting display rate of 100%. Conclusion:Clinical application of lumbar spondylolysis patients taking spiral CT of the MPR,MIP and VRT cutting technology can effectively observed in patients with lesion site,MPR,MIP is the diagnosis of spondylolysis optimal method,three-dimensional sense of strong VRT.%  目的:探讨多层螺旋CT后处理方法MPR、MIP及VRT结合剖切技术在腰椎峡部裂中的应用效果。方法:选取本院2010年10月-2012年8月收治的87例腰椎峡部裂患者进行多层螺旋CT检查,并采取MPR、MIP及VRT进行处理,观察其临床诊断效果。结果:通过比较分析,其中,MPR和MIP的显示率均为100%,而VRT切割前显示率为94.0%,VRT切割后显示率为100%。结论:临床中腰椎峡部裂患者采取多层螺旋CT的MPR、MIP及VRT剖切技术能够有效的观察患者病变部位,MPR、MIP是诊断椎弓峡部裂的最佳方法,VRT的立体感较强。

  8. Effect of Multi Slice Spiral CT in the Diagnosis of Gastrointestinal Tract Perforation%多层螺旋CT在胃肠道穿孔诊断中的应用效果

    Institute of Scientific and Technical Information of China (English)

    高运英

    2014-01-01

    Objective To explore the clinical application of multislice spiral CT in the diagnosis of gastrointestinal tract perforation in effect. Methods In our hospital diagnosed as gastrointestinal perforation in 42 cases of the disease, to get the related information of their multi slice spiral CT scanning. Research on MSCT the image data, analyze the internal various features of abdominal and free gas ratio. Results In all 42 patients, diagnosed by MSCT were 39 cases, accounting for about 92.86%. In addition to, accurately determine the position of the 25 cases, about 59.52%. Also observe gastrointestinal tumor, abscess, and effusion lesions. Conclusion The clinical application of multi slice spiral CT in the diagnosis of gastrointestinal tract perforation has very good effect, can improve the diagnosis rate and hole position accuracy. This method is suitable for use in clinical practice.%目的:探讨多层螺旋CT在胃肠道穿孔中的诊断效果。方法回顾性分析经病理确诊为胃肠穿孔患者的多层螺旋CT扫描的相关资料共42例,探究MSCT所得影像资料,分析腹腔内部各种特征和游离气体比例等。结果在所有42例病患中,经MSCT确诊的有39例,约占92.86%。此外,准确确定穿孔位置的有25例,约占59.52%。同时观察到胃肠道有肿块、脓肿、积液等病变。结论多层螺旋CT应用于胃肠道穿孔诊断方面有很好的效果,有利于提高确诊率和孔道位置准确率,此方法适合在临床上推广使用。

  9. 多层螺旋CT后处理技术在诊断肺隔离症中的应用%Application of Multi-slice Spiral CT Post-processing Technique in the Diagnosis of Pulmonary Sequestration

    Institute of Scientific and Technical Information of China (English)

    杨珂

    2015-01-01

    目的:探讨多层螺旋CT(MSCT)增强簿层扫描及图像后处理技术在肺隔离症(PS)的诊断价值。方法分析经临床手术病理、主动脉造影证实的21例肺隔离症患者的胸部多层螺旋CT平扫及CTA检查,并进行多平面重建(MPR)、最大密度投影法重建(MIP)、容积重建(VR)。结果21例病例均为单发,肺隔离症(PS)位于左肺下叶14例,右肺下叶7例;表现为肺野内团片、实性肿块者15例,囊样病灶者6例;21例孕杂的供血动脉均来自自体动脉,其中18例来自胸主动脉分支,3例来自腹主动脉。结论多层螺旋CT(MSCT)后处理技术能较准确、直观显示肺隔离症的供血动脉,可以取代有创DSA检查。%Objective To evaluate the multi-slice spiral CT (MSCT) reinforced thin layer scanning and image processing technique in the diagnosis of pulmonary sequestration (PS) value. Methods Analysis the clinical operation pathology, aortic angiography confirmed 21 cases of chest multi-slice spiral CT plain scan and CTA of pulmonary sequestration were examined, multi planar reconstruction (MPR), and the reconstruction of maximum intensity projection (MIP), volume rendering (VR). Results 21 cases were solitary, pulmonary sequestration (PS) located in the left lower lobe in 14 cases, right pulmonary lower lobe in 7 cases;for the performance of lung field of tanacu, solid mass in 15 cases, 6 cases of cystic lesion; artery in 21 cases of PS were derived from autologous artery, including 18 cases from aortic branch, 3 cases from the abdominal aorta. Conclusion Multi slice spiral CT (MSCT) after treatment technology can accurately, visual display of pulmonary sequestration artery, can replace invasive DSA examination.

  10. Clinical Application of the 16-Slice Spiral CT Testing Scan Technique in Pulmonary Angiography%16层螺旋CT测试扫描技术在肺动脉成像中的临床应用

    Institute of Scientific and Technical Information of China (English)

    邓波红; 张任华; 侯海文; 龙江涛; 彭丹丹

    2014-01-01

    Objective: To explore the Application of the 16-slice spiral CT testing scan technique in pulmonary angiography, in order to improve the quality of CTPA. Methods:50 CTPA in testing scan group and conventional scan group respectively were examined with GE Light speed 16-slice spiral CT. The data of al patients were transmit ed to the workstation (ADW4.2) and reconstruction. The quality of al images were evaluated by three experienced doctors using double-blind method in charge in four grades (A,B,C and bad), and the mean peak time of main Artery of al grade A were also compared. Results:Testing scan:the rate of A,B,C and bad was 90%、6%、4% and 0% respectively. conventional scan: the rate of grade A,B,C and bad was 62%、12%、22% and 4% respectively. Conclusion: Testing scan technique is superior than conventional scan in image quality of 16-slice spiral CT pulmonary angiography . Testing scan technique is good for radiographic diagnosis and remedies.%目的:探讨16层螺旋C T测试扫描技术在肺动脉成像中的应用,以期提高肺动脉造影(CTPA)的图像质量。方法:应用GE Light Speed 16层螺旋CT扫描仪进行测试扫描和传统扫描各50例C T PA,所有扫描重建图像传送至AW4.2工作站进行后处理重组,并分别由3名经验丰富的CT诊断医师采用双盲法,对2种方法的图像质量进行评价,分别统计优、良、可、差。结果:测试扫描:优90%、良6%、可4%、差0%;传统扫描:优62%、良12%、可22%、差4%。结论:应用测试扫描技术进行16层螺旋C T肺动脉成像所得诊断图像质量明显优于传统扫描,有助于放射诊断及治疗。

  11. Clinical application of the tracking scan technique in 16-slice spiral CT angiography%跟踪扫描技术在16层螺旋CT动脉成像中的临床应用

    Institute of Scientific and Technical Information of China (English)

    张任华; 邓波红; 龙江涛; 李强; 杨友; 陈美英

    2009-01-01

    目的 探讨跟踪扫描技术在16层螺旋CT动脉成像中的应用.方法 应用GE LightSpeed 16层螺旋CT扫描仪进行跟踪扫描、测试扫描和估算扫描各100例CTA,所有扫描图像传送至AW4.2工作站进行后处理重建,并分别由3名经验丰富的CT诊断医师采用双盲法对3种方法的图像质量进行评价,分别统计优、良、可、差.结果 跟踪扫描图像质量优级率89.00%、良7.00%、可4.00%、差0;测试扫描优级率70.00%、良11.00%、可15.00%、差4.00%;估算扫描优级率61.00%、良13.00%、可21.00%、差5.00%.结论 应用跟踪扫描技术进行16层螺旋CT动脉成像所得图像质量明显优于测试扫描和估算扫描.%Objective To explore the application of the tracking scan technique in 16-slice spiral CT angiography, in order to improve the quality of CTA. Methods Three hundred patients who were divided into three groups randomly underwent CTA in tracking, testing and estimation scan respectively with GE LightSpeed 16-slice spiral CT. The data of all patients were transmitted to the workstation (AW4.2) and reconstructed. The quality of all images were evaluated by three experienced doctors with double-blind method and divided into four grades (A, B, C and D) from optimal to poor. Results The rate of grade A, B, C and D was 89.00%, 7.00%, 4.00% and 0 respectively for tracking scan, 70.00%, 11.00%, 15.00% and 4.00% respectively for testing scan, while 61.00%, 13.00%, 21.00% and 5.00% respectively for estimation scan. Conclusion Tracking scan technique is superior to testing and estimation scan in image quality of 16-slice spiral CT angiography.

  12. Dual source spiral CT three dimensional reconstruction in the interventional treatment of liver cancer%双源螺旋CT三维重建技术在肝癌介入治疗中的应用

    Institute of Scientific and Technical Information of China (English)

    王东林; 陈广礼

    2011-01-01

    目的 探讨双源螺旋CT三维重建技术在肝癌介入治疗中的应用价值.方法 对37例肝癌患者进行双源螺旋CT扫描诊断后,在后处理工作站进行容积再现(VR)、最大密度投影(MIP)血管重建.结果 肝动脉期VR图像和MIP多平面重建图像均能清晰显示腹腔干、脾动脉、肝总动脉左右动脉及其2~3级分支,还能清晰显示1~6级门静脉血管结构及1~3级肝静脉血管分支,具有较强的空间立体感.结论 双源螺旋CT门静脉三维重建成像是一种快捷而有效的无创性血管造影技术,有助于临床治疗方案的合理选择及疗效随访.%Objective To investigate the value of dual source spiral CT three dimensional reconstruction in the interventional treatment. Methods Totally 37 patients with liver cancer for dual source spiral CT scan diagnosis, in the post -processing workstation for volume rendering ( VR), maximum intensity projection (MIP) revascularization. Results The hepatic arterial phase MIP,VR images and multiplanar reconstruction images could clearly show the celiac trunk, splenic artery, hepatic artery about 2 ~ 3 artery and its branches, but also clearly show the 1 ~ 6 Class doors and 1 vein structure three branches of hepatic veins, with a strong spatial dimension. Conclusions The dual source spiral CT three dimensional reconstruction of portal vein imaging is a fast and effective non - invasive vascular imaging techniques, useful in clinical treatment choice and efficacy of a reasonable follow - up.

  13. Correlation Study between Spiral CT Perfusion Imaging and Angiogenesis in Esophageal Carcinoma%食管癌螺旋CT灌注成像与肿瘤血管生成的相关性研究

    Institute of Scientific and Technical Information of China (English)

    宋涛; 黎海亮; 窦新民; 吴越; 刘予东

    2011-01-01

    目的 探讨食管癌螺旋CT灌注成像与肿瘤血管生成的相关性.资料与方法 对50例食管癌患者行多排螺旋CT灌注扫描,分析食管癌CT灌注成像参数血容量(BV)、血流量(BF)、平均通过时间(MTT)、表面通透性(PS)与微血管密度(MVD)及血管内皮生长因子(VEGF)表达之间的关系.结果 50例食管癌中,VEGF阳性表达率为62%(31/50),阴性表达率为38%(19/50),MVD值在两组间的差异具有统计学意义(P<0.05);BF值与MVD呈正相关(P<0.05),BV及PS值与MVD呈显著性正相关(P<0.01),MTT值与MVD无相关性(P>0.05);PS值与VEGF表达呈正相关(P<0.05),BF、BV及MTT与VEGF表达无相关性(P>0.05).结论 食管癌CT灌注成像能够在一定程度上反映活体的肿瘤血管生成状况.%Objective To evaluate the correlation between spiral CT perfusion imaging and angiogenesis in esophageal carcinoma. Materials and Methods Multi-detector spiral CT perfusion scan was performed in 50 patients with esophageal carcinoma. The relationship of the CT perfusion imaging parameters, including blood volume ( BV) , blood flow( BF), mean transit time( MTT) ,and permeability surface( PS),with MVD and expressions of VEGF were analyzed. Results In 50 cases,the VEGF positive expression rate was 62% (31/50),and the negative expression rate was 38% ( 19/50). The mean MVD of VEGF-positive group were significantly higher than those of negative group ( P 0.05). The PS value and VEGF expression were positively correlated( P 0.05 ). Conclusion CT perfusion parameters can reflect not only the angiogenesis of esophageal carcinoma of the MVD,but also the expression of VEGF,indicating that CT perfusion parameters can be used as an assessment of tumor angiogenesis in vivo.

  14. 正常胰腺不同部位的多层螺旋CT灌注成像研究%A study on multi-slice spiral CT perfusion imaging in different parts of normal pancreas

    Institute of Scientific and Technical Information of China (English)

    张喜荣; 黄小华; 董国礼; 张小明; 敬宗林; 郭静

    2012-01-01

    目的 应用多层螺旋CT灌注成像技术,探讨正常胰腺头、体和尾部的血流灌注特点.方法 选择临床行中上腹增强CT检查并符合正常胰腺纳入标准的患者35例,采用Toshiba Aquilion 16层螺旋CT先行平扫,在胰腺头、体和尾部显示完整的中心层面进行胰腺同层动态增强扫描,将扫描后所得影像数据传输到Vitrea 2.0后处理工作站,采用Toshiba体部灌注软件对正常胰腺各部位灌注参数做三点测量,其每部三点测量的平均值视为各部灌注参数最后值,并对各部灌注参数行统计学分析.结果 正常胰腺头部、体部和尾部的血流量(BF)、血容量(BV)、表面通透性(PS)和平均通过时间(MTT)的测量值分别为:头部(128.34±29.23) mL·100 g-1·min-1,(43.19±13.77) mL/100 g,(218.39±99.21) mL·100 g-1·min-1,(299.26±81.99)0.1 s;体部 (136.20±23.00) mL·100 g-1·min-1,(44.63±13.74) mL/100 g,(223.20±73.82) mL·100 g-1·min-1,(310.99±59.00) 0.1 s;尾部(128.04±27.67) mL·100 g-1·min-1,(46.04±20.14) mL/100 g,(232.24±76.65) mL·100 g-1·min-1,(299.96±71.45) 0.1 s.3组参数间均无统计学意义(P>0.05).结论 正常胰腺头部、体部和尾部供血动脉有所差异,但各部组织血流灌注基本一致.%Objective To explore the blood flow perfusion characteristics of different parts of normal pancreas by means of multi-slices spiral CT perfusion imaging. Methods Thirty-five patients without pancreatic disease,received contrast-enhanced CT exami-nation for the venter superior abdomen by 16-slice spiral CT. The completely displayed center level in the head,body and tail of nor-mal pancreas were examined by dynamic enhancement scanning. These data were processed on a Start Vitrea 2. 0 workstation by using Toshiba body software package. The three-point measurement approach was used to examin the parameters of blood flow (BF) ,blood volume (BV) ,permeability surface (PS) and mean transit time (MTT) of pancreatic tissues in

  15. Multilayer spiral CT Scanning in Transitional cell Carcinoma of Bladder and Application Analysis%多层螺旋CT扫描在膀胱移行细胞癌中的应用分析

    Institute of Scientific and Technical Information of China (English)

    黄云开; 曾怡群

    2013-01-01

      目的探讨多层螺旋CT诊断膀胱移行细胞癌的应用价值。方法收集48例经手术病理证实的膀胱移行细胞癌患者的CT影像资料与临床资料,展开回顾性的研究。结果48例患者中,CT术前检测出45例,未检出3例;单发病灶25例,多发病灶20例;菜花状28例,乳头状8例,局限性膀胱壁增厚9例。结论多层螺旋CT能够准确地诊断出膀胱移行细胞癌,在病理诊断的基础上,充分结合CT影像资料,将极大提高分期诊断的准确率。%Objective Application of multislice helical CT in diagnosis of bladder transitional cel cancer value. Methods Col ection of 48cases confirmed by operation and pathology of bladder transitional cel cancer patients CT images and clinical data, launched a retrospective study. Results In 48 patients, CT preoperative detection of out of 45 cases, 3 cases of solitary lesions not detected; in 25 cases, multiple lesions in 20 cases; 28 cases of papil ary cauliflower-like, in 8 cases, limitations of the bladder wal thickening in 9 cases. Conclusion Multi slice spiral CT can accurately diagnose of bladder transitional cel carcinoma, the diagnosis based on pathology, ful y integrated CT imaging data, wil greatly improve staging accuracy rate of diagnosis.

  16. Dynamic CT findings of eosinophilic hepatic abscess and its clinical course

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Dae Hyoun; Chang, Jae Chun; Seong, Ki Ho [Yeungnam Univ. School of Medicine, Taegu (Korea, Republic of)

    1996-01-01

    To evaluate dynamic CT features and its clinical courses of eosinophilic hepatic abscess. Two-phase dynamic CT findings and the clinical courses of 13 pathologically proven cases of eosinophilic abscess were reviewed. All patients showed peripheral eosinophilia, and diagnoses were confirmed by ultrasound-guided biopsy(n=9) or operation(n=4). In two of the four patients who underwent segmental hepatectomy, worms of the species fasciola hepatica were detected. Follow-up CT scans after treatment with antibiotics or praziquantel were available in seven and eitht patients, respectively. All hepatic lesions were found in a subcapsular location or in contact with Glisson's capsule around the bile duct Arterial-dominant phase CT(n=11) demonstrated clusters of ill-defined low density masses without rim enhancement. Late-phase CT(n=13) more clearly depicted clustering lesions with enhancing rims and diminyution of the low-density area. Follow-up CT scans after treatment with antibiotics(n=7) showed no change in the lesions in three patients and slight shrinkage of the main mass with additional new lesions in four. On CT scans of nine patients performad after praziquantel therapy, hepatic masses were seen in all patients to be very slightly smaller after improvement of peripheral hypereosinophilia. Two-phase dynamic CT features appear to be helpful for the diagnosis of eosinophilic hepatic abscess in patients with peripheral eosinophilia. Parasitic infestation by Fasciola hepatica for example, is the presumed cause of such abscesses, though further studies are required.

  17. Abdominal 4D flow MR imaging in a breath hold: combination of spiral sampling and dynamic compressed sensing for highly accelerated acquisition.

    Science.gov (United States)

    Dyvorne, Hadrien; Knight-Greenfield, Ashley; Jajamovich, Guido; Besa, Cecilia; Cui, Yong; Stalder, Aurélien; Markl, Michael; Taouli, Bachir

    2015-04-01

    To develop a highly accelerated phase-contrast cardiac-gated volume flow measurement (four-dimensional [4D] flow) magnetic resonance (MR) imaging technique based on spiral sampling and dynamic compressed sensing and to compare this technique with established phase-contrast imaging techniques for the quantification of blood flow in abdominal vessels. This single-center prospective study was compliant with HIPAA and approved by the institutional review board. Ten subjects (nine men, one woman; mean age, 51 years; age range, 30-70 years) were enrolled. Seven patients had liver disease. Written informed consent was obtained from all participants. Two 4D flow acquisitions were performed in each subject, one with use of Cartesian sampling with respiratory tracking and the other with use of spiral sampling and a breath hold. Cartesian two-dimensional (2D) cine phase-contrast images were also acquired in the portal vein. Two observers independently assessed vessel conspicuity on phase-contrast three-dimensional angiograms. Quantitative flow parameters were measured by two independent observers in major abdominal vessels. Intertechnique concordance was quantified by using Bland-Altman and logistic regression analyses. There was moderate to substantial agreement in vessel conspicuity between 4D flow acquisitions in arteries and veins (κ = 0.71 and 0.61, respectively, for observer 1; κ = 0.71 and 0.44 for observer 2), whereas more artifacts were observed with spiral 4D flow (κ = 0.30 and 0.20). Quantitative measurements in abdominal vessels showed good equivalence between spiral and Cartesian 4D flow techniques (lower bound of the 95% confidence interval: 63%, 77%, 60%, and 64% for flow, area, average velocity, and peak velocity, respectively). For portal venous flow, spiral 4D flow was in better agreement with 2D cine phase-contrast flow (95% limits of agreement: -8.8 and 9.3 mL/sec, respectively) than was Cartesian 4D flow (95% limits of agreement: -10.6 and 14.6 m

  18. Performance comparison between static and dynamic cardiac CT on perfusion quantitation and patient classification tasks

    Science.gov (United States)

    Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R.; La Riviere, Patrick J.; Alessio, Adam M.

    2015-03-01

    Cardiac CT acquisitions for perfusion assessment can be performed in a dynamic or static mode. In this simulation study, we evaluate the relative classification and quantification performance of these modes for assessing myocardial blood flow (MBF). In the dynamic method, a series of low dose cardiac CT acquisitions yields data on contrast bolus dynamics over time; these data are fit with a model to give a quantitative MBF estimate. In the static method, a single CT acquisition is obtained, and the relative CT numbers in the myocardium are used to infer perfusion states. The static method does not directly yield a quantitative estimate of MBF, but these estimates can be roughly approximated by introducing assumed linear relationships between CT number and MBF, consistent with the ways such images are typically visually interpreted. Data obtained by either method may be used for a variety of clinical tasks, including 1) stratifying patients into differing categories of ischemia and 2) using the quantitative MBF estimate directly to evaluate ischemic disease severity. Through simulations, we evaluate the performance on each of these tasks. The dynamic method has very low bias in MBF estimates, making it particularly suitable for quantitative estimation. At matched radiation dose levels, ROC analysis demonstrated that the static method, with its high bias but generally lower variance, has superior performance in stratifying patients, especially for larger patients.

  19. 中央型小细胞肺癌和鳞癌的多层螺旋CT表现分析%Analysis of Multi Slice Spiral CT in Central Type Small Cell Lung Cancer and Squamous Cell Carcinoma

    Institute of Scientific and Technical Information of China (English)

    陈亮

    2016-01-01

    目的:对中央型小细胞肺癌和鳞癌的多层螺旋 CT 表现进行分析探讨,为今后的临床诊断工作,提供有价值的参考信息。方法选择2014年8月~2015年5月我院收治的获得明确诊断的,中央型小细胞肺癌与鳞癌患者共计48例作为研究对象,对其展开多层螺旋 CT 检查,并对检查资料展开回顾性分析。结果观察发现,中央型小细胞肺癌患者的胸膜腔存在积液、远处有转移、支气管狭窄无阻塞、心脏大血管受到侵害、肺叶发生实变、纵隔肺门淋巴结肿大、淋巴结融合发生率较鳞癌患者高(P <0.05);对比发现,两组患者心包腔积液、胸膜结节、支气管不全性阻塞、肺不张发生率比较,差异无统计学意义(P >0.05)。鳞癌患者肿瘤不均匀强化、坏死、支气管闭塞发生率较中央型小细胞肺癌高(P <0.05)。结论中央型小细胞肺癌、鳞癌患者的多层螺旋 CT 表现存在一定差异,综合分析,可做出准确鉴别。%Objective Purpose of center type smal cel lung cancer and squamous cel carcinoma of the multislice spiral CT findings were analyzed for future clinical work,providing valuable reference information. Methods From August 2014 to May 2015,our hospital access to diagnosis,central smal cel lung cancer in patients with squamous cel carcinoma of 48 cases studied,the multi-slice spiral CT examination and check the information retrospectively. Results Observed that patients with central type smal cel lung cancer pleural cavity effusion,distant have transfer,bronchial stenosis,non blocking, heart and great vessels have been infringed,lobar occur consolidation,mediastinal and hilar lymph nodes,lymph node fusion rate is high in patients with squamous cel carcinoma(P 0.05)in two groups of patients with pericardial effusion, pleural nodules,bronchial obstruction,and the incidence of lung failure. The incidence of non homogeneous enhancement

  20. 螺旋CT多平面重组在膈疝诊断中的价值%Value of Spiral CT Multi-planar Reconstruction in Diagnosing of Diaphragmatic Hernia

    Institute of Scientific and Technical Information of China (English)

    李杰; 杨光钊; 丁忠祥; 林毅; 李伟; 韩志江

    2011-01-01

    Objective To explore the value of spiral CT multi-planar reconstruction(MPR) in diagnosing diaphragmatic hernia. Materials and Methods Spiral CT MPR was performed in patients suspected with diaphragmatic hernia. The diameters of diaphragmic hiatus measured by different reconstruction methods were compared and statistic analyzed. Results Fifteen cases of esophageal hiatus hernia,3 cases of traumatic diaphragmatic hernia,2 cases of diaphragmatic eventration, 2 cases of triangle hernia between vertebral lumbar and rib and I case of diaphragmatic hernia occurred after operation were collected. CT axial and MPR imagings in revealing diaphragmatic hernia were compared. There was significant difference between CT axial and MPR imagings in displaying diaphragmatic hiatus. There was significant difference between CT axial and MPR imagings in measuring the diameter of diaphragmatic hiatus. Conclusion Spiral CT MPR can clearly show the diaphragmatic hiatus and also can precisely measure the diameter of diaphragnatic hernia. It plays an important role in diagnosing various types of diaphragmatic hernia and can guide to therapy.%目的 探讨膈的CT多平面重组(MPR)对膈疝诊断的价值及其临床意义.资料与方法 对临床有相关提示或胸、腹部CT轴面图像疑为膈疝的病例同时进行MPR,对膈肌裂孔显示情况和不同成像方式测得膈肌裂孔左右径数值进行统计学分析.结果 临床确诊食管裂孔疝15例、外伤性膈疝3例、膈膨升2例、腰肋三角疝2例、术后膈疝1例.比较CT轴面和MPR图像对膈疝的显示情况,并通过Wilcoxin秩和检验分析两者的差异,得出Wilcox-in为425.500,P<0.01,两者之间的差异有统计学意义.对于13例两种成像方式都能清楚显示膈疝的病例分别测量膈肌裂孔左右径,采用配对t检验分析CT轴位、MPR图像上测量膈肌裂孔左右径的差异,得出t=-6.307,P<0.001,两者之间的差异有统计学意义,MPR测量膈肌裂孔左右

  1. 螺旋CT血管造影诊断主动脉瘤的临床应用价值%Clinical application value of spiral CT angiography in diagnosis of aortic aneurysm

    Institute of Scientific and Technical Information of China (English)

    赖振辉; 李晚君; 崔东; 吴伟清

    2012-01-01

    目的 探讨多层螺旋CT血管造影在诊断腹主动脉瘤中的应用价值.方法 收集我院腹主动脉瘤患者44例,均行多层螺旋CT扫描检查后,采用不同重建方式进行图像后处理,观察病变部位影像学特征.结果 44例患者均能够显示清晰瘤体以及周围血管与瘤体的位置关系,且可观察附壁血栓并能准确测量动脉瘤的三维数据.本组44例腹主动脉瘤患者螺旋CT血管造影资料显示,均存在附壁血栓症状,其中,合并髂动脉瘤4例,有动脉瘤破裂迹象4例.多平面重建可清晰显示动脉瘤局限部位及其与周围组织、血管解剖关系,而最大密度投影法、容积再现技术能进一步对管腔各段较精确测量.结论 螺旋CT血管造影扫描检查腹主动脉瘤具有操作简便、快速、直观及诊断准确等特点,是一种腹主动脉瘤有效的检查方法.%Objective To explore the application value of multislice spiral CT angiography in the diagnosis of abdominal aortic aneurysm. Methods 44 patients with abdominal aortic aneurysm in our hospital were selected to receive multislice spiral CT scanning, after which different reconstruction methods were used for image post-processing and the imaging characteristics of lesions were observed. Results All the 44 patients showed clear aneurysm and the location relationship between surrounding vessels and aneurysm. The mural thrombus could be observed and the three-dimensional data of a-neurysm could be accurately measured. The spiral CT angiography data of 44 patients with abdominal aortic aneurysm showed that mural thrombus symptoms were found in all the patients. Among them, 4 patients had combined iliac a-neurysm and 4 patients had aneurysm rupture signs. Multi-planar reconstruction could clearly show the location of a-neurysm and its relationship with surrounding tissue and vessels. And the maximum intensity projection method and volume rendering technique could further measure the segments of

  2. Characterization of focal liver lesions with a new ultrasound contrast agent using continuous low acoustic power imaging: comparison with contrast enhanced spiral CT; Caratterizzazione delle lesioni focali epatiche con mezzo di contrasto ecografico e metodica di imaging continuo a basso indice meccanico: paragone con la TC spirale con contrasto

    Energy Technology Data Exchange (ETDEWEB)

    Passamonti, Matteo; Vercelli, Alessandro; Azzaretti, Andrea; Rodolico, Giuseppe; Calliada, Fabrizio [Ospedale Maggiore di Lodi, U. O. Radiologia, Lodi (Italy)

    2005-04-01

    Purpose: To evaluate the concordance of the enhancement patterns of a new ultrasound contrast agent (SonoVue) with those obtained with dual-phase contrast-enhanced spiral CT (CE-CT) in the characterization of focal liver lesions (FLLs). Materials and methods: Sitxty-two patients with focal liver lesions discovered at ultrasound and also studied with CECT underwent contrast-enhanced ultrasound using continuous low acoustic power imaging after receiving a 2.4 ml bolus of the new US contrast agent SonoVue, consisting of a dispersion of sulphur hexafluoride micro bubbles. The examinations were made using ATL HDI-5000, Acuson SEQUOIA and Aloka 5500 Prosound ultrasound systems with 5.2 MHz curved-array probes. The concordance between US and CE-CT images was evaluated on site by two radiologists blinded to CT results. The FLLs were assessed in the arterial (20 s after CM injection), portal (after 45-60 s) and late (after 120 s) phases for: 1) presence/absence of enhancement, 2) distribution of enhancement (homogenous or target distribution, centripetal or centrifugal flow, and other), 3) qualitative enhancement pattern (hyper-echoic, hypoechoic, or isoechoic) versus normal liver parenchyma. Results: The concordance between SonoVue-enhanced US and CE-CT was 85%. Moreover during portal venous phase with CEUS it was possible to differentiate between malignancy or benignity of 91% of lesions. Conclusions: The preliminary data obtained in this study suggest that continuous low acoustic power imaging and contrast-enhanced US show similar results to CT in contrast distribution and contrast enhancement patterns. [Italian] Scopo: Valutare la concordanza dei pattern di enhancement ottenuti con un nuovo ecocontrasto, SonoVue, con i noti pattern contrastografici della TC spirale multifasica nella caratterizzazione delle lesioni focali epatiche. Materiale e metodi: Sessantadue pazienti con lesioni focali epatiche diagnosticate ad un esame ecografico e con esame TC con contrasto, sono

  3. 用螺旋CT血管造影多轴向投照容积重建检查颅内动脉瘤%Detection of intracranial aneurysms with spiral CT angiography and MPVR

    Institute of Scientific and Technical Information of China (English)

    刘光彦; 潘功茂; 钱晓凌

    2001-01-01

    目的:探讨螺旋CT血管造影(SCTA)多轴向投照容积重建(MPVR)在颅内动脉瘤检查中的合理应用。 方法:11例临床拟诊颅内动脉瘤的患者行SCTA检查,每例均用MPVR法成像。 结果:MPVR正确检出前交通动脉瘤5例,右后交通动脉瘤1例,基底动脉瘤1例,4例阴性。 结论:针对颅内动脉瘤的好发部位,用MPVR法合理选择薄片厚度、中心线和旋转角度、窗中心,能完整地显示脑底动脉环(Willis环)和颈内、基底动脉主干及其主要分支,提高脑动脉瘤检出率。%Objectives:To explore the optimal method of spiral CT angiography and MPVR in the detection of intracranial aneurysms. Methods:Eleven patients with clinical suspicion of intracranial aneurysms underwent spiral CT angiography, then postprocessed with MPVR. Results:,Five anterior communicating aneurysms,1 posterior communicating aneurysm and 1 base aneurysm were found with MPVR. Conclusions: Lesions at the circle of Willis, the main trunk of the carotid and the vertebrobasilar arteries, including their branches could be visualized perfectly with MPVR by optimizing the thickness, center, angle of rotation and window level, by which more intracranial aneurysms could be found.

  4. Detection and classification of different liver lesions: Comparison of Gd-EOB-DTPA-enhanced MRI versus multiphasic spiral CT in a clinical single centre investigation

    Energy Technology Data Exchange (ETDEWEB)

    Böttcher, Joachim [Institute of Diagnostic and Interventional Radiology, SRH Clinic Gera, Str. des Friedens 122, 07548 Gera (Germany); Hansch, Andreas [Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University, Jena University Hospital, Erlanger Allee 101, 07740 Jena (Germany); Pfeil, Alexander [Department of Internal Medicine III, Friedrich-Schiller-University, Jena University Hospital, Erlanger Allee 101, 07740 Jena (Germany); Schmidt, Peter [Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University, Jena University Hospital, Erlanger Allee 101, 07740 Jena (Germany); Malich, Ansgar [Institute of Diagnostic Radiology, Suedharz Clinic Nordhausen, Dr. Robert-Koch-Str. 39, 99734 Nordhausen (Germany); Schneeweiss, Albrecht [Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University, Jena University Hospital, Erlanger Allee 101, 07740 Jena (Germany); Maurer, Martin H.; Streitparth, Florian [Department of Radiology, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin (Germany); Teichgräber, Ulf K. [Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University, Jena University Hospital, Erlanger Allee 101, 07740 Jena (Germany); Renz, Diane M., E-mail: diane.renz@charite.de [Department of Radiology, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin (Germany)

    2013-11-01

    Objective: To compare the diagnostic efficacy of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) vs. multidetector computed tomography (MDCT) for the detection and classification of focal liver lesions, differentiated also for lesion entity and size; a separate analysis of pre- and postcontrast images as well as T2-weighted MRI sequences of focal and exclusively solid lesions was integrated. Methods: Twenty-nine patients with 130 focal liver lesions underwent MDCT (64-detector-row; contrast medium iopromide; native, arterial, portalvenous, venous phase) and MRI (1.5-T; dynamic and tissue-specific phase 20 min after application of Gd-EOB-DTPA). Hepatic lesions were verified against a standard of reference (SOR). CT and MR images were independently analysed by four blinded radiologists on an ordinal 6-point-scale, determining lesion classification and diagnostic confidence. Results: Among 130 lesions, 68 were classified as malignant and 62 as benign by SOR. The detection of malignant and benign lesions differed significantly between combined and postcontrast MRI vs. MDCT; overall detection rate was 91.5% for combined MRI and 80.4% for combined MDCT (p < 0.05). Considering all four readers together, combined MDCT achieved sensitivity of 66.2%, specificity of 79.0%, and diagnostic accuracy of 72.3%; combined MRI reached superior diagnostic efficacy: sensitivity 86.8%, specificity 94.4%, accuracy 90.4% (p < 0.05). Differentiated for lesion size, in particular lesions <20 mm revealed diagnostic benefit by MRI. Postcontrast MRI also achieved higher overall sensitivity, specificity, and accuracy compared to postcontrast MDCT for focal and exclusively solid liver lesions (p < 0.05). Conclusion: Combined and postcontrast Gd-EOB-DTPA-enhanced MRI provided significantly higher overall detection rate and diagnostic accuracy, including low inter-observer variability, compared to MDCT in a single centre study.

  5. Spiral CT Diagnosis of Acute Pancreatitis Classification Method and its Clinical Significance%急性胰腺炎的螺旋CT诊断分级方法及临床意义

    Institute of Scientific and Technical Information of China (English)

    杨晓生; 陈勤; 陈惜峰

    2012-01-01

    目的:探讨急性胰腺炎的16层螺旋CT诊断分级方法及临床意义。方法:回顾性分析2009~2011年间急性胰腺炎住院患者41例,其中男23例,女18例。所有患者均作CT平扫和增强扫描。结果:按照CT严重指数分级评分:根据得分将结果依次分为3个等级:轻级(0~3分)23例,占56.1%,中级(4~6分)7例,占17.1%,重级(7~10分)11例,占26.8%。结论:螺旋CT为急性胰腺炎的诊断提供了直观的形态学依据,CTSI不仅能精确反映急性胰腺炎的病变程度,而且能较准确早期判断急性胰腺炎病情、预后,并对其临床治疗方案及预后具有重要意义。%Objective:Discussion of 16 slice spiral CT in the diagnosis of acute pancreatitis classification method and its clinical significance. Method:A retrospective analysis of 2009~2011 years of acute pancreatitis in 41 patients, male 23 cases, female 18 cases. All patients underwent CT plain scan and enhanced scan. Result:According to the CT severity index score, CTSI:According to the score will result in turn is divided into 3 grades:Light level (0~3) in 23 cases, accounting for 56.1%, intermediate (4~6) in 7 cases, accounting for 17.1%, heavy(7~10) in 11 cases, accounting for 26.8%. Conclusion:Spiral CT for the diagnosis of acute pancreatitis provides intuitive basis, CTSI not only can accurately reflect the severity of acute pancreatitis, and can accurately judge the severity of acute pancreatitis in early stage and prognosis of acute pancreatitis, clinical treatment and prognostic significance.

  6. A discrete electromechanical model for human cardiac tissue: effects of stretch-activated currents and stretch conditions on restitution properties and spiral wave dynamics.

    Directory of Open Access Journals (Sweden)

    Louis D Weise

    Full Text Available We introduce an electromechanical model for human cardiac tissue which couples a biophysical model of cardiac excitation (Tusscher, Noble, Noble, Panfilov, 2006 and tension development (adjusted Niederer, Hunter, Smith, 2006 model with a discrete elastic mass-lattice model. The equations for the excitation processes are solved with a finite difference approach, and the equations of the mass-lattice model are solved using Verlet integration. This allows the coupled problem to be solved with high numerical resolution. Passive mechanical properties of the mass-lattice model are described by a generalized Hooke's law for finite deformations (Seth material. Active mechanical contraction is initiated by changes of the intracellular calcium concentration, which is a variable of the electrical model. Mechanical deformation feeds back on the electrophysiology via stretch-activated ion channels whose conductivity is controlled by the local stretch of the medium. We apply the model to study how stretch-activated currents affect the action potential shape, restitution properties, and dynamics of spiral waves, under constant stretch, and dynamic stretch caused by active mechanical contraction. We find that stretch conditions substantially affect these properties via stretch-activated currents. In constantly stretched medium, we observe a substantial decrease in conduction velocity, and an increase of action potential duration; whereas, with dynamic stretch, action potential duration is increased only slightly, and the conduction velocity restitution curve becomes biphasic. Moreover, in constantly stretched medium, we find an increase of the core size and period of a spiral wave, but no change in rotation dynamics; in contrast, in the dynamically stretching medium, we observe spiral drift. Our results may be important to understand how altered stretch conditions affect the heart's functioning.

  7. Spiral inflation

    Directory of Open Access Journals (Sweden)

    Gabriela Barenboim

    2015-02-01

    Full Text Available We propose a novel scenario of primordial inflation in which the inflaton goes through a spiral motion starting from around the top of a symmetry breaking potential. We show that, even though inflation takes place for a field value much smaller than Planck scale, it is possible to obtain relatively large tensor-to-scalar ratio (r∼0.1 without fine tuning. The inflationary observables perfectly match Planck data.

  8. 多排螺旋CT与CR在肋骨骨折诊断中的比较%Comparison of Multi-slice Spiral CT and CR in Rib Fracture

    Institute of Scientific and Technical Information of China (English)

    高雷

    2016-01-01

    Objective Evaluation of row Multi-slice Spiral CT and CR use value in the diagnosis of rib fracture, and to discuss the advantages of two different methods in the diagnosis of rib fracture, so look for ways to improve the accuracy of diagnosis. Methods Retrospective analysis of 60 patients who check rib fracture from 2014 to 2015 in our hospital because of chest trauma. The patients were randomly divided into CT inspection group and CR inspection group, and each group of 30 cases. Among them CT inspection group: male 19, female 11; CR inspection group: male 17, female 13. Two radiologists doctor diagnosis with double-blind method. Results 1 ~ 3 ribs: The diagnostic accuracy of CT was 46.3% (25/54), and the diagnostic accuracy of CR was 74.4% (32/43);4~8 ribs:The diagnostic accuracy of CT was 88.5% (119/135), and the diagnostic accuracy of CR was 55.1% (81/147); 9~12 ribs: The diagnostic accuracy of CT was 91.7% (55/60), and the diagnostic accuracy of CR was 53.2% (33/62). False positive misdiagnosis rate of CT was 15.1% (71/471), and false positive misdiagnosis rate of CR was 7.1% (33/468). Conclusion Multi-slice spiral CT and CR each other and cooperate with the inspection can effectively improve the accuracy of diagnosis of rib fracture, meanwhile reduce missed diagnosis and misdiagnosis rate.%目的:评价多排螺旋CT与CR在肋骨骨折诊断中的运用价值,探讨两种检查方法各自诊断肋骨骨折的优势,寻找提高诊断准确性的检查方法。方法回顾性分析2014~2015年60例因胸部外伤后来我院行影像学检查诊断有无肋骨骨折的患者。将患者随机分为CT检查组和CR检查组,每组30例。其中CT检查组:男19例,女11例;CR检查组:男17例,女13例。由放射科两名主治医师采用双盲法进行诊断。结果第1~3肋骨:CT诊断准确率为46.3%(25/54),CR诊断准确率为74.4%(32/43);第4~8肋骨:CT诊断准确率为88.5%(119/135),CR诊断准确率为55.1%(81/147);第9~12

  9. Clinical Application of Multi-Planar Reconstruction with 64-slice Spiral CT on Protrusion of Spondylolisthesis%64层螺旋CTMPR重组对腰椎滑脱的临床应用

    Institute of Scientific and Technical Information of China (English)

    刘兆芹; 钱学江

    2011-01-01

    Objective To investigate the value of multi-planar reconstruction(MPR) with 64-slice spiral CT for disease of spondylolisthesis.Methods MPRimages of 100 cases with spondylolisthesis were compared at random.Results MPR images could show not the graduation of spondylolisthesis,and could demonstrate isthmicspondy lolisthesis(ISS) or degenerative lumbar spondylolisthesis,but also could show the changes of peripheral soft tissue,the facet degeneration,and soft tissue structure.Conclusion 64-slices CT MPR images has more advantages in demonstrating the reason of spondylolisthesis,and can supply the reliable information for clinical doctors,is helpful for clinical doctors to choose the appropriate therapeutic schedule.[Chinese Medical Equipment Journal,2011 ,32(4 ) : 75-76]%目的:探讨64层螺旋CT多平面重组(MPR)对腰椎滑脱的临床应用价值.方法:随机抽取100例腰椎滑脱患者的CT MPR重建图像资料.结果:MPR不仅能够显示腰椎滑脱的分度,辨别是峡部型(真性)或是退变型滑脱(假性),并且能够显示合并的腰椎间盘膨出、小关节退变及周围软组织结构改变.结论:64层螺旋CT MPR图像,有利于全面、直观地显示腰椎滑脱的原因,并且能够为临床医生提供可靠信息,有助于临床医生选择合适的治疗方案.

  10. Clinical Diagnostic Value of Spiral CT Ocular Trauma (Analysis of 30 Cases)%螺旋CT对眼外伤的临床诊断价值(附30例分析)

    Institute of Scientific and Technical Information of China (English)

    周道田

    2014-01-01

    Objective To explore the clinical diagnostic value of CT of ocular trauma. Methods A total of 30 patients with ocular trauma in the data to carry on the experiment and analysis. Results Ocular trauma mainly for orbital fracture, optic nerve damage and fracture, ocular trauma, intraocular foreign bodies, eye soft tissue injury and combined with head and facial injuries. Conclusion CT examination in the diagnosis of ocular trauma, simple operation, rapid and reliable diagnosis, has important significance in clinical prognosis and evaluation of treatment;compared with otherimaging examination, spiral CT scan in the diagnosis of ocular trauma has incomparable advantages, ocular trauma should be preferred CT scan examination.%目的:探讨CT对眼外伤的临床诊断价值。方法抽取30例眼外伤患者的资料进行实验并加以分析。结果眼外伤主要表现为眼眶骨折、视神经损伤及骨折、眼球损伤、眼球异物、眼部软组织损伤以及合并颅脑及颌面部损伤等。结论 CT检查诊断眼外伤,操作简便,诊断迅速可靠,对临床选择治疗方案及评估预后具有重要意义;与其他影像学检查相比较,螺旋CT检查诊断眼外伤具有无与伦比的优越性,眼外伤应首选CT扫描检查。

  11. {sup 18}F-FDG PET/CT imaging versus dynamic contrast-enhanced CT for staging and prognosis of inflammatory breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Champion, Laurence; Edeline, Veronique; Giraudet, Anne-Laure; Wartski, Myriam [Service de Medecine Nucleaire, Saint-Cloud (France); Lerebours, Florence [Service d' Oncologie Medicale, Saint-Cloud (France); Cherel, Pascal [Institut Curie, Hopital Rene Huguenin, Service de Radiologie, Saint-Cloud (France); Bellet, Dominique [Service de Medecine Nucleaire, Saint-Cloud (France); Universite Paris Descartes, Pharmacologie Chimique et Genetique and Imagerie, Inserm U1022 CNRS UMR 8151, Faculte des sciences pharmaceutiques et biologiques, Paris (France); Alberini, Jean-Louis [Service de Medecine Nucleaire, Saint-Cloud (France); Universite Versailles Saint-Quentin, Faculte de medecine, Saint-Quentin-en-Yvelines (France)

    2013-08-15

    Inflammatory breast cancer (IBC) is the most aggressive type of breast cancer with a poor prognosis. Locoregional staging is based on dynamic contrast-enhanced (DCE) CT or MRI. The aim of this study was to compare the performances of FDG PET/CT and DCE CT in locoregional staging of IBC and to assess their respective prognostic values. The study group comprised 50 women (median age: 51 {+-} 11 years) followed in our institution for IBC who underwent FDG PET/CT and DCE CT scans (median interval 5 {+-} 9 days). CT enhancement parameters were net maximal enhancement, net early enhancement and perfusion. The PET/CT scans showed intense FDG uptake in all primary tumours. Concordance rate between PET/CT and DCE CT for breast tumour localization was 92 %. No significant correlation was found between SUVmax and CT enhancement parameters in primary tumours (p > 0.6). PET/CT and DCE CT results were poorly correlated for skin infiltration (kappa = 0.19). Ipsilateral foci of increased axillary FDG uptake were found in 47 patients (median SUV: 7.9 {+-} 5.4), whereas enlarged axillary lymph nodes were observed on DCE CT in 43 patients. Results for axillary node involvement were fairly well correlated (kappa = 0.55). Nineteen patients (38 %) were found to be metastatic on PET/CT scan with a significant shorter progression-free survival than patients without distant lesions (p = 0.01). In the primary tumour, no statistically significant difference was observed between high and moderate tumour FDG uptake on survival, using an SUVmax cut-off of 5 (p = 0.7 and 0.9), or between high and low tumour enhancement on DCE CT (p > 0.8). FDG PET/CT imaging provided additional information concerning locoregional involvement to that provided by DCE CT on and allowed detection of distant metastases in the same whole-body procedure. Tumour FDG uptake or CT enhancement parameters were not correlated and were not found to have any prognostic value. (orig.)

  12. 门静脉系统血栓的64层螺旋CT诊断价值%The Diagnostic Value of Thrombus in Portal Vein on 64-slice Spiral CT

    Institute of Scientific and Technical Information of China (English)

    韩新巍; 周朋利; 郑颖; 丁鹏绪; 路慧彬; 司江涛

    2009-01-01

    Objective To study the 64-slice spiral CT feature of the thrombus in portal vein. Materials and Methoils Noocontrast-enhanced CT and contrast enhanced CT were performed in all 15 patients. MIP,VR and MPR were used for three dimensional reconstruction. The features of the throw.bus in portal vein were analyzed. Results In 15 cases, 13 cases(83%) occurred in trunk vein,6 cases in right branch,7 cases in left branch,3 cases in splenic vein,9 cases in superior mesenterie vein. Yerdel Grade:Grade Ⅰ1 case,Grade Ⅱ10 cases, Grade Ⅲ 3 cases,GradelV 1 case. 10 cases showed high-dense in thrombus ,3 cases appeared low-dense. 12 cases presented partial filling defect, which is described as stripe and bundles in contrasted vein. All the involved vein had smooth and successive wall and had no appeared nodes protrude out at portal vein period. All the cases with thrombus showed typical track sign or line augmentation sign in involved vein wall. 12 cases displayed collateral circulation in esophag-ogastricand splenic vein, and 4 cases displayed pericholecystic and pericholedochal collateral branches. No case visualized A-P shunt. Conclusion 64-slice spiral CT can display the location, feature and cumulative branch of the thrombus in portal vein distinctly and stereoscopically. 64-slice spiral CT is very important modality for the thrombus in portal vein.%目的 探讨门静脉系统血栓(portal vein thrombosis,PVT)的64层螺旋CT表现特征.资料与方法 15例PVT行64层螺旋CT平扫和双期增强扫描,采用最大密度投影(MIP)、容积再现(VR)及多平面重组(MPR)观察其影像学特征.结果 15例中,血栓发生于门静脉(PV)主干13例,右支6例,左支7例,脾静脉(SV)3例,肠系膜上静脉(SMV)9例,其中血栓同时累及PV主干和SMV 8例,同时累及PV左右支、主干和SMV 4例,累及PV主干和右支6例,累及PV主干和左支6例,累及SV和SMV 2例,PV主干、SV、SMV三岔口处血栓1例.Yerdel分级:Ⅰ级1例,Ⅱ级10例,Ⅲ级3

  13. The Features Multislice Spiral CT Results for Hepatic Angiomyolipoma and Their Pathological Basis%肝脏血管平滑肌脂肪瘤的多层螺旋CT表现特征及其病理学基础

    Institute of Scientific and Technical Information of China (English)

    胡雅君; 卢春燕; 刘荣波; 张薇薇

    2011-01-01

    目的 探讨肝脏血管平滑肌脂肪瘤(hepatic angiomyolipoma,HAML)的多层螺旋CT影像学表现特征及其与病理学基础的相关性,以进一步提高CT诊断的准确性.方法 收集2008年11月- 2010年12月经手术病理证实的16例HAML患者.所有患者均行螺旋CT平扫及动脉期、门脉期增强检查,重点观察HAML的分型及其相应CT表现及影像-病理的相关性.结果 16例患者共20个病灶,19个为稍低密度病灶,其中11个病灶内可见明显的脂肪密度影;1个为稍高密度病灶.动脉期所有病灶均有不同程度的强化表现,15个病灶内可见到较明显条状及扭曲的血管影.门脉期15个病灶有持续强化.结论 多层螺旋CT能准确反映HAML的分型及其病理特征,对临床表现不典型患者的诊断和鉴别诊断有较大诊断价值.%Objective To discuss the correlation between the features of multislice spiral CT results for hepatic angiomyolipoma (HAML) and their pathological basis, and to further improve the diagnostic accuracy through CT examination. Methods Sixteen HAML patients diagnosed pathologically between November 2008 and December 2010 in our hospital were enrolled in our study. All patients underwent multi-slice spiral CT scanning of pre-and post-contrast arterial phase, and portal venous phase. Focus was put on observation of HAML types and their corresponding manifestations, and the correlation between CT imaging and the pathologic basis. Results There were 20 lesions in the 16 patients. Among the 19 hypodense lesions, 11 were clearly seen with fat density shadow. One out of the 20 lesions showed as slightly hyperdense. On the arterial phase scanning, all lesions showed enhancement, and obvious vascular shadow could be seen inl5 lesions. On the portal venous phase, 15 lesions continued to strengthen. Conclusions Multi-slice spiral CT can accurately reflect the classification of HAML and its pathological features. It has a great value in the diagnosis

  14. The Value of Spiral CT Perfusion Imaging in Diagnosis of Adrenal Hyperplasia%螺旋CT灌注成像在肾上腺增生的诊断价值

    Institute of Scientific and Technical Information of China (English)

    袁庆城; 曲雅梅; 张年邱; 赖剑华

    2011-01-01

    Objective: To study the clinical application value of spiral CT perfusion imaging in diagnosis of adrenal hyperplasia. Methods: Spiral CT perfusion imaging was performed in 23 healthy volunteers and 18 patients with adrenal hyperplasia. CT perfusion parameters including relative blood flow (RBF), mean transmit time (MTT) and permeability surface (PS) were analyzed. The test was used in the statistical analysis for the CT perfusion parameters. Results: RBF, MTT and PS of normal adrenal gland were 0.63 ± 0.22 mL/100g/min, 70.65 ± 12.31 s, 0.72 ± 0.13 mL/100g/min respectively. RBF, MTT and PS of adrenal hyperplasia were 0.45 ± 0.19 mL/100g/min, 118.39 ± 19.98 s, 0.49 ±0.21 mL/100g/min respectively. RBV and PS in normal adrenal gland were higher than that of adrenal hyperplasia, while MTT in adrenal hyperplasia was higher than that of normal adrenal gland. There was significant difference of RBF, MTT and PS between normal adrenal gland and adrenal hyperplasia (t = 15.91,20.03, 9.96, respectively, P < 0.05). Conclusion: Spiral CT perfusion imaging is a feasible functional examination for adrenal gland. It reflects the microcirculatory blood flow of adrenal gland and provides useful information for differential diagnosis in adrenal hyperplasia.%目的:研究多层螺旋CT灌注成像在肾上腺增生的诊断价值.方法:对23例正常肾上腺和18例经临床证实的肾上腺增生进行16层螺旋CT灌注成像研究,利用CT灌注软件计算灌注参数,包括相对血流量(RBF)、平均通过时间(MTT)和表面通透性(PS),参数间比较采用t检验.结果:正常肾上腺的RBF、MTT和PS分别为0.63±0.22mL/100g/min、70.65±12.31 s和0.72±0.13mL/100g/min,肾上腺增生RBF、MTT和PS分别为0.45±0.19mL/100g/min、118.39±19.98 s和0.49±0.21mL/100g/min.正常肾上腺的RBF、PS均大于肾上腺增生,肾上腺增生的MTT大于正常肾上腺,其差异有统计学意义(t值分别为15.91、20.03和9.96,P<0.05).结论:肾上腺多层螺

  15. Dynamic CT perfusion image data compression for efficient parallel processing.

    Science.gov (United States)

    Barros, Renan Sales; Olabarriaga, Silvia Delgado; Borst, Jordi; van Walderveen, Marianne A A; Posthuma, Jorrit S; Streekstra, Geert J; van Herk, Marcel; Majoie, Charles B L M; Marquering, Henk A

    2016-03-01

    The increasing size of medical imaging data, in particular time series such as CT perfusion (CTP), requires new and fast approaches to deliver timely results for acute care. Cloud architectures based on graphics processing units (GPUs) can provide the processing capacity required for delivering fast results. However, the size of CTP datasets makes transfers to cloud infrastructures time-consuming and therefore not suitable in acute situations. To reduce this transfer time, this work proposes a fast and lossless compression algorithm for CTP data. The algorithm exploits redundancies in the temporal dimension and keeps random read-only access to the image elements directly from the compressed data on the GPU. To the best of our knowledge, this is the first work to present a GPU-ready method for medical image compression with random access to the image elements from the compressed data.

  16. 螺旋CT平扫及重建技术辅助上颌前牙种植15例%Case report of 15 dental implantation assisted with spiral CT in anterior region of maxilla

    Institute of Scientific and Technical Information of China (English)

    王仁欣; 张占利; 董鹏飞

    2013-01-01

    Objective: To evaluate the clinical efficiency of 64-slice spiral CT in the anterior maxilla. Methods:15 patients with delayed implantation in anterior region of maxilla was examed with CT scan and/or 3D reconstruction, and dental implantation doctors account for the complications and assisted surgery operation of implantation, and get the advantage of CT images VS X-Ray. Results: CT images can stereoscopically and directly reveal the height, width and density of the implantation zone,which helps dental implantation doctors to have a fluent communication with patients. Conclusion:CT images can provide reliable evidence for planning a precise surgery and benefit doctors communicating with their patients. CT scan should be suggested an necessary examine in implantation of anterior maxilla.%  目的:探讨采用64排CT平扫及重建技术在上颌前牙种植中应用的临床意义。方法:对我科近2年来上颌前牙延期种植患者术前进行64排CT平扫/(及)重建,根据CT结果,进行术前分析设计,与患者沟通解释种植手术所需要的其他辅助操作及手术并发症,总结CT图像对手术的指导意义及在医患沟通方面的优势。结果:CT扫描能清晰地显示出种植区骨密度、骨厚度及高度情况,有利手术方案的制定,增强了种植医师对手术解释的说服力和医患之间的信任程度,更有利医患沟通。结论:上颌前牙种植前的CT扫描检查对上颌前牙种植的术前指导及医患沟通具有重要的临床意义,建议CT扫描做为上颌前牙种植前的常规检查。

  17. Dynamic CT Features of a hemangioma originating from the parietal pleura: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won Kyung; Park, Jai Soung; Park, Sang Hyun; Cha, Jang Gyu; Shin, Hwa Kyoon; Koh, Eun Suk [Soonchunhyang Univ. Bucheon Hospital/Soonchunhyang Univ. College of Medicine, Bucheon (Korea, Republic of)

    2012-06-15

    A pleural hemangioma is an extremely rare disease. Few studies have reported on the radiologic appearance of chest wall hemangioma, especially originating from the parietal pleura. We describe a 45 year old female patient with a soft tissue mass in the parietal pleura showing centripetal enhancement on dynamic CT. The patient underwent surgery and the pathologic examination confirmed the presence of a capillary hemangioma.

  18. 64排螺旋CT功能成像技术在兔急性肾损伤诊断中的价值%Value of 64-slice spiral CT functional imaging techniques for diagnosis of acute kidney injury in rabbits

    Institute of Scientific and Technical Information of China (English)

    赵效新; 王新宇; 王文红; 李亚军; 孙浩然; 孟祥鹿; 顾程

    2016-01-01

    Objective To quantitatively assess renal hemodynamic changes in hypertensive acute kidney injury in rabbits induced by L-NAME using 64-slice spiral CT functional imaging techniques,and to explore the application of these techniques in evaluation of early kidney functional changes.Methods Fourteen female New Zealand white rabbits were randomly divided into normal control group (n=6)and L-NAME group (n=8).The control group was injected NaCl solution and the L-NAME group was injected the same amount of L-NAME solution to make hypertensive acute kidney injury model.64-slice spiral CT and SPECT were scanned af-ter injection.Blood samples were collected before and after injecting NaCl and L-NAME solution to detect serum creatinine (Cr).Cr level and CT perfusion parameters of the two groups were analyzed and compared with the pathology results.GFRCT detected by con-trast-enhanced CT and GFRSPECT detected by SPECT were analyzed by the rank correlation test.Results Renal blood volume,blood flow,permeability surface,time to peak,and peak value had statistically significant differences between the control and L-NAME group (P <0.05).GFRCT and GFRSPECT had obvious correlation.GFRCT of L-NAME group was obviously lower than that of the con-trol group.The kidneys of L-NAME group showed obviously injured under both light microscope and microscope.Conclusion 64-slice spiral CT functional imaging techniques can dynamically observe and quantitatively assess early hypertensive kidney dysfunc-tion,especially unilateral renal blood flow abnormalities.It is an effective examination in quantitatively assessing kidney function.%目的:利用64排螺旋 CT 功能成像技术定量分析 N-硝基-L-精氨酸甲酯(L-NAME)致兔高血压急性肾损伤后肾血流动力学变化,探讨该技术在评估早期肾功能损伤中的应用价值。方法将14只雌性新西兰大白兔随机分成正常对照组(n=6)和 L-NAME 组(n=8)。对照组注入氯化钠(NaCl)溶液,L-NAME

  19. Value of 64-slice spiral CT perfusion imaging in estimating the efficacy of transcatheter arterial chemoembolization for the treatment of hepatocellular carcinoma%64排螺旋CT灌注成像在肝细胞癌介入治疗前后的评估价值

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Objective To discuss the clinical value of 64-slice spiral CT perfusion imaging(CTPI) in estimating the efficacy of transcatheter arterial chemoembolization ( TACE ) for hepatocellular carcinoma (HCC).Methods Using 64-slice spiral CT(GE LightSpeed VCT XT),all CT plain scan and perfusion scan were performed in 30 patients with HCC 1-3 days before and 30-40 days after TACE .Using deconvolution through Infusion Software analysis , hepatic blood flow ( BF ) , blood volume ( BV ) , the mean transit time ( MTT) , hepatic arterial fraction ( HAF ) , permeability surface ( PS ) were caculated to evaluate HCC embolization hemodynamic status .Results After TACE,the tumor was totally filled with lipiodol in 12 cases and partially filled with lipiodol in 18 cases.BF,BV,MTT,HAF and PS perfusion maps showed that lack of blood perfusion was found in lipiodol-filling areas, but sparsely or insufficiently lipiodol-filled areas were hyperperfusion.BF,BV,HAF and PS of HCC after TACE were lower than those of HCC before TACE (P0.05 ) .Conclusions 64-slice spiral CT liver perfusion imaging can be used to monitor the blood supply changes in non -iodized oil deposits area non-invasively ,dynamically ,quantitatively ,which was very important in judging the tumor tissue survival and played an important role in response evaluation of HCC interventional therapy and guiding the follow -up treatment.%目的:探讨64排螺旋CT灌注成像(CTPI)在原发性肝细胞癌(HCC)肝动脉插管化疗栓塞( TACE )术前、后疗效的评估价值。方法选取30例HCC 患者,于TACE术前1~3 d、术后30~40 d应用GE LightSpeed VCT XT(64排128层螺旋CT)分别行全肝常规平扫及灌注扫描,运用灌注软件进行分析,计算肝血流量(BF)、血容量(BV)、平均通过时间(MTT)、肝动脉灌注指数(HAF)、毛细血管通透性( PS )等,统计分析相关参数,以评价 HCC 介入治疗前后的血流动力学状态。结果 TACE

  20. Beautiful math--aesthetic patterns based on logarithmic spirals.

    Science.gov (United States)

    Xinchang Wang; Peichang Ouyang

    2013-01-01

    A simple, fast method generates various visually appealing spiral patterns. The method is based on the concept that spiral patterns comprise a symmetry group of tilings. It employs invariant mappings and a dynamical system to create seamless colored patterns.

  1. 多层螺旋CT扫描及曲面重建在外伤性面瘫的应用价值%Applied Value of Multislice Spiral CT and Curved PlanarReformation for Traumatic Facial Nerve Paralysis

    Institute of Scientific and Technical Information of China (English)

    黄少鹏; 叶青; 林美福; 陈娟; 王一红; 李瑞玉

    2011-01-01

    目的 探讨多层螺旋CT(MSCT)扫描及面神经管曲面重建(CPR)在外伤性面瘫中的应用价值.方法 对15例外伤性面瘫患者的颞骨行MSCT高分辨率扫描,并通过工作站行CPR,观察面神经损伤平面,并选择相应的手术径路行面神经减压术.结果 术前MSCT扫描及CPR提示,3例面神经损伤主要在迷路段及膝状神经节的,采用颅中窝乳突联合径路;12例损伤主要位于膝状神经节以下,选择乳突径路.术中所见与术前CT提示均一致.术后随访6月~5年,15例患者Ⅰ级恢复7例、Ⅱ级恢复7例、Ⅲ级恢复1例.结论 MSCT扫描及CPR能清晰显示面神经管的全貌及其损伤部位,对外伤性面瘫的诊断及手术治疗具有重要意义.%Objective To investigate the applied value of multislice spiral CT(MSCT) and Curved planar reformation(CPR) for traumatic facial nerve paralysis and the guidance significance for surgery.Methods 15 cases of traumatic facial nerve paralysis were scanned by MSCT, Post processing images of facial nerve canal were completed by GE Advantage 4.2 work station. Different Surgical approaches of facial nerve decompression were selected according to the injured location described by MSCT and CPR.Results A combined middle fossa and transmastoid approach was chosen in 3 cases whose injured location above geniculate ganglion. A pure transmastoid route was performed in the other 12 cases whose injured location under geniculate ganglion. After 0.5-5 years' follow-up, 7 cases recovered to grade Ⅰ according to House-Brackmann facial nerve function scores, 7 cases recovered to grade Ⅱ and the other 1 case recovered to grade Ⅲ. Conclusion multislice spiral CT (MSCT) and Curved planar reformation (CPR)could help to study the facial nerve canal and describe precise localization for traumatic facial nerve paralysis, which provide reliable basis for clinical diagnosis and treatment.

  2. Spiralling upward.

    Science.gov (United States)

    Schulgasser, Kalman; Witztum, Allan

    2004-09-21

    Thin vertical leaves often manifest twist. Perhaps the most prominent example of this is in Typha sp., but such twist is also apparent in Narcissus, Pancratium and many other genera. Such a blade is often referred to as a "spiral leaf". We will indicate the mechanical advantage afforded to the leaf by this arrangement, i.e. that it permits the leaf to achieve a greater height without losing stability, that is bending over due to its own weight. We quantify this gain and show how by a simple experiment it can be shown that the advantage is indeed utilized in nature. Typha domingensis is offered as an example.

  3. Three-dimensional rebuilding of fixed bridge based on the digital images by spiral CT%基于计算机三维重建技术的固定桥有限元实体建模

    Institute of Scientific and Technical Information of China (English)

    林燕; 冯春霞

    2016-01-01

    目的:研究螺旋CT扫描图像的固定桥计算机三维重建的方法。方法:采用美国PQ6000型螺旋CT扫描机,自下颌颏部下缘开始至鼻骨底做连续横断超薄扫描,得到人牙齿的二维CT图像。应用图像处理与识别合成软件,读取二维CT图像数据文件,通过灰度分割方法对二维图像进行边缘提取,再利用三维表面重建算法对所截取的二维CT图像进行三维重建,最终获得固定桥的三维重建影像。结果:获得了包括牙齿、牙周膜、牙槽骨在内的下颌后牙三单位固定桥的三维有限元数学模型。模型可以根据要求任意进行旋转、缩放、透视、剖开等多种方式观察,并可以按照不同研究目的和要求对模型进行修改和调整。结论:基于螺旋CT扫描图像的固定桥计算机三维重建,可为有限元实体建模提供快捷、方便的方法。%Objective:To study the three dimensional rebuilding method of fixed bridge based on the digital images by spiral CT. Method:By the PQ6000 spiral CT,successive cross-sectional scanning was made from the inferior edge of the mandibular chin to the bottom of the nasal bone to obtain the two-dimensional digital images. Using the image processing and recognition software,two-dimensional CT image data file was established. Two-dimensional gray image segmentation method was adopted for edge detection. Further,three-dimensional surface reconstruction algorithm was used for the three-dimensional reconstruction of the fixed bridge by intercepted two-dimensional image. Result:Three-dimensional image of fixed bridge,including abutment teeth,periodontal membrane and alveolar bone,was obtained,which was rather vivid in every detail,and could be rotated,dissected,perspected,and intercepted optionally. It made the observation of images from different angles as possible. The reconstruction showed satisfactory replicating effects. Conclusion:Three-dimensional reconstruction

  4. 16层螺旋CT多期增强扫描对小肝癌的诊断研究%Contrast-enhanced 16 multi-slice spiral CT scans for the diagnosis of small hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    郭敬深; 夏广明; 罗剑云; 陈锦灿

    2011-01-01

    目的 研究小肝癌(SHCC)在16层螺旋CT( SCT)多期(动脉期、门脉期和延迟期)增强扫描的表现特征,提高小肝癌的诊断水平及评价其应用价值。方法 收集53例SHCC进行回顾性分析,所有病例均行16层螺旋CT多期增强扫描,扫描时间分别为动脉期34~40s、门脉期65~80s、延迟期4~6 min,用高压注射器经静脉注射,速率为2.5~3 ml/s,剂量为85~95 ml,观察SHCC在各期的强化方式。结果 共发现70个病灶,平扫、动脉期、门脉期和延迟期的检出率分别为70.0%、97.1%、82.9%和87.1%,动脉期的敏感性高于门脉期和延迟期。结论 16层螺旋CT多期增强扫描能充分反映SHCC在增强中的血供变化特点,提高了SHCC的检出率及定性诊断的准确性。%Objective To improve the diagnostic level for small hepatocellular carcinoma ( SHCC )by exploring the characteristic appearance of SHCC on constract-enhanced 16-slice spiral CT multi-phase ( arterial, portal venous phase, and delayed phase ) scans. Methods The data on 53 patients with SHCC were retrospectively analyzed. All the patients received 16-slice spiral CT multi-phase scans, with scanning time of 34-40s at arterial phase, 65-80s at portal venous phase, and 4-6min at delayed phase. The constract of 85-95ml was intravenously injected at a velocity of 2.5-3 ml/s with a high pressure syringe. The enhancement patterns of SHCC were observed at different phases. Results 75lesions were found. The detection rate was 70.0% for plain scan, 97.1% for arterial phase, 82.9% for portal phase, and 87.1% for delayed phase, with a sensitivity higher in arterial phase than in portal phase and delayed phase. Conclusions Contrast-enhanced 16-slice spiral CT scans can fully reflect the enhancing characteristics of blood supply in SHCC, improving the detection rate and the accuracy of diagnosis.

  5. The Diagnostic Value and Type of Multi-slice Spiral CT Reconstruction in Small Renal Carcinomas%多层螺旋CT三维重建对小肾癌的诊断及分型

    Institute of Scientific and Technical Information of China (English)

    宋强; 汪秀玲; 胡春峰

    2011-01-01

    Objective:According to the CT scan image and the performance of three-dimensional reconstruction,to study the diagnostic value and type of MSCT reconstruction in small renal carcinomas.Materials and Methods:A retrospective analysis was done for 43 cases of small renal carcinomas which received MSCT examination and confirmed by pathology in our hospital,analysis and type them with their performance in the CT examination.Results:There are 16 cases of small renal carcinoma of protruding type,their performance of CT examination are the tumors convex to the outline of the kidney or convex to the renal pelvis or calyx,when in enhancement CT scan,the contrast agent in the tumor are fast flowing in and fast flowing out which are the performance of malignant tumor;There are 6 cases of small renal carcinoma of inside renal parenchyma type,their performance of CT examination are the tumors limited in the renal parenchyma,when in enhancement CT scan,the performance of the tumor are f the typical performance of malignant tumor;There are 9 cases of small renal carcinoma of cystic type,their performance of CT examination are that when in enhancement CT scan,there are multiple enhanced uneven thickness stripes or small pitchy enhancement in the tumor;There are 5 cases of small renal carcinoma of multiple type,their performance of CT examination are that there are multiple small renal carcinomas in one kidney.Conclusion:Multi-slice spiral CT scan with 3D reconstruction image post-processing techniques can accurately and effectively diagnose various types of small renal carcinoma.%目的:根据CT扫描图像及三维重建表现,探讨多层螺旋CT扫描对小肾癌的诊断及鉴别诊断的价值,并对小肾癌进行分型。资料与方法:收集行多层螺旋CT扫描并经临床病理证实的43例小肾癌病例资料,就其CT表现进行分析并进行分型。结果:凸出型小肾癌23例,CT表现为肿瘤凸向肾轮廓之外或凸向肾盂、肾盏,增强

  6. Dynamic bowtie filter for cone-beam/multi-slice CT.

    Directory of Open Access Journals (Sweden)

    Fenglin Liu

    Full Text Available A pre-patient attenuator ("bowtie filter" or "bowtie" is used to modulate an incoming x-ray beam as a function of the angle of the x-ray with respect to a patient to balance the photon flux on a detector array. While the current dynamic bowtie design is focused on fan-beam geometry, in this study we propose a methodology for dynamic bowtie design in multi-slice/cone-beam geometry. The proposed 3D dynamic bowtie is an extension of the 2D prior art. The 3D bowtie consists of a highly attenuating bowtie (HB filled in with heavy liquid and a weakly attenuating bowtie (WB immersed in the liquid of the HB. The HB targets a balanced flux distribution on a detector array when no object is in the field of view (FOV. The WB compensates for an object in the FOV, and hence is a scaled-down version of the object. The WB is rotated and translated in synchrony with the source rotation and patient translation so that the overall flux balance is maintained on the detector array. First, the mathematical models of different scanning modes are established for an elliptical water phantom. Then, a numerical simulation study is performed to compare the performance of the scanning modes in the cases of the water phantom and a patient cross-section without any bowtie and with a dynamic bowtie. The dynamic bowtie can equalize the numbers of detected photons in the case of the water phantom. In practical cases, the dynamic bowtie can effectively reduce the dynamic range of detected signals inside the FOV. Furthermore, the WB can be individualized using a 3D printing technique as the gold standard. We have extended the dynamic bowtie concept from 2D to 3D by using highly attenuating liquid and moving a scale-reduced negative copy of an object being scanned. Our methodology can be applied to reduce radiation dose and facilitate photon-counting detection.

  7. On the Fully-Developed Heat Transfer Enhancing Flow Field in Sinusoidally, Spirally Corrugated Tubes Using Computational Fluid Dynamics

    DEFF Research Database (Denmark)

    Hærvig, Jakob; Sørensen, Kim; Condra, Thomas Joseph

    2017-01-01

    A numerical study has been carried out to investigate heat transfer enhancing flow field in 28 geometrically different sinusoidally, spirally corrugated tubes. To vary the corrugation, the height of corrugation e/De/D and the length between two successive corrugated sections p/Dp/D are varied in ...

  8. 64排螺旋CT多种后处理技术在肋骨骨折诊断中的应用%Application of Various Post Processing Techniques of 64 Slice Spiral CT in the Diagnosis of Rib Fractures

    Institute of Scientific and Technical Information of China (English)

    潘兴朋

    2016-01-01

    目的:探讨64排螺旋CT多种后处理技术对肋骨骨折的诊断价值。方法以本院2014年2月-2016年2月就诊的疑似肋骨骨折75例胸部外伤患者为研究对象,均行X线平片、多层螺旋CT轴位、容积再现(VR)、多平面重建(MPR)等后处理技术检查,比较不同影像学方法对肋骨骨折、骨折数量检出情况。结果临床、影像学检查及复查确诊肋骨骨折165处,CT轴位、CT后处理技术对肋骨骨折例数检出率分别为96.00%、98.67%,较X线平片的80.00%差异有统计学意义(P<0.05)。CT后处理技术对肋骨骨折数量检出率为99.39%,较X线平片、CT轴位的71.52%、78.79%差异有统计学意义(P<0.05)。漏诊情况:X线平片漏诊41处,其中以肋软骨附近漏诊最多,占58.54%;CT轴位漏诊24处,其中肋软骨附近、腋段肋骨漏诊各5处;CT后处理技术未漏诊,可疑骨折数1处。结论64排螺旋CT后处理技术对肋骨骨折、骨折数量检出率高,漏诊率低,能有效弥补X线平片、CT轴位不足。%Objective To investigate the value of various post processing techniques of 64 slice spiral CT in the diagnosis of rib fractures. Methods 75 cases of patients with thoracic trauma and suspected rib fractures who were treated in our hospital between February 2014 and February 2016 were selected as study subjects. All of them were examined by X-ray plain film, multi-slice spiral axial CT, volume rendering (VR), multi planar reconstruction (MPR) and other post-processing techniques. The situation of different imaging methods in the detection of rib fractures and number of fractures was compared. Results 165 rib fractures were diagnosed by clinical, imaging examination and reexamination. The detection rates of axial CT and CT post processing techniques in number of cases with rib fractures were 96.00%and 98.67%, respectively. Compared with X-ray plain film (80.00%), the difference was significant (P<0.05). The

  9. Dynamic Changes of the CT Perfusion Parameters in the Embolic Model of Cerebral Ischemia

    Institute of Scientific and Technical Information of China (English)

    陈唯唯; 漆剑频; 张进华; 黄文华; 宋金梅

    2004-01-01

    To study the dynamic changes of CT perfusion parameters during the first 12 h in the embolic cerebral ischemia models. Local cerebral ischemia model were established in 7 New Zealand white rabbits. All CT scans were performed with a GE Lightspeed 16 multislice CT. Following the baseline scan, further CT perfusion scans were performed at the same locations 20 min, 1-6 h and8, 10 and 12 h after the embolus delivery. Maps of all parameters were obtained by CT perfusion software at each time point. The brains, taken 12 h after the scan, were sliced corresponding to the positions of the CT slices and stained by 2,3,5-triphenyltetrazolium chloride (TTC). On the basis of the TTC results, the ischemicsides were divided into 3 regions: core, penumbra and the relatively normal region. The changes of all parameters were then divided into 3 stages. In the first two hours (the first stage), the CBV dropped more remarkably in the core than in the penumbra but rose slightly in the relatively normal region while the CBF decreased and MTT, TTP extended in all regions to varying degrees. In the 2nd-5th h (the second stage), all the parameters fluctuated slightly around a certain level. In the 5th-12th h (the third stage), the CBV and CBF dropped,and MTT and TTP were prolonged or shortened slightly in the core and penumbra though much notably in the former while the CBV, CBF roseand MTT, TTP were shortened remarkably in the relatively normal region. We experimentally demonstrated that the location and extent of cerebral ischemia could be accurately assessed by CT perfusion imaging. The pathophysiology of the ischemia could be reflected by the CT perfusion to varying degrees.

  10. 128排螺旋CT在头颈动脉应用效果的调查研究%Investigation of Application Effect of 128Multislice Spiral CT in the Head and Neck Artery

    Institute of Scientific and Technical Information of China (English)

    于晓娟; 于飞

    2016-01-01

    Objective To study the application effect of 128multislice spiral CT in the head and neck artery. Methods 120 cases of subjects with head and neck artery CT examination in our hospital from August 2015 to April 2016 were selected as the research objects, and 120 cases of patients with routine instrument CT examination at the same period were selected as the control group, and the subject case and CT examination results were retrospectively analyzed, and the imaging quality of CT image was scored according to the scoring criterion. Results In the observation group, 3 marks were in 88 cases, ac-counting for 73%, 2 marks were in 22 cases, accounting for 18%, 1 mark was in 9 cases, accounting for 8%, 0 mark was in 1 case, accounting for 1%. In the control group, 3 marks were in 34 cases, accounting for 28%, 2 marks were in 35 cases, accounting for 29%, 1 mark was in 40 cases, accounting for 33%, 0 mark was in 11 case, accounting for 9%, and there was an obvious difference in the imaging quality between the two groups (P<0.05). Conclusion The application of 128multislice spiral CT in the head and neck artery has the features of high accurate rate and high efficiency.%目的:探讨128排螺旋CT在头颈动脉应用效果。方法选取2015年8月-2016年4月于该院进行头颈动脉CT检查的120位受试者作为研究对象,另将同期采用常规仪器进行CT检查的120位患者作为对照组,回顾性分析受试者的病例及CT检查结果,根据评分标准对CT影像的图像质量进行评分。结果观察组:评分为3分的受试者为88例,占73%;评分为2分的受试者为22例,占18%;评分为1分的受试者为9例,占8%;评分为0分的受试者为1例,占1%。对照组:评分为3分的受试者为34例,占28%;评分为2分的受试者为35例,占29%;评分为1分的受试者为40例,占33%;评分为0分的受试者为11例,占9%。观察组与对照组的图像质量差异有统计学意义(P<0.05)

  11. The clinical value of multi-slice spiral CT perfusion imaging in diagnosis of thyroid diseases%多层螺旋CT灌注成像在甲状腺疾病诊断中的临床价值

    Institute of Scientific and Technical Information of China (English)

    龚礼春

    2015-01-01

    ObjectiveTo investigate the clinical application value of multi-slice spiral CT perfusion imaging in diagnosis of thyroid diseases.Methods 112 patients with thyroid diseases in our hospital from January 2011 to December 2014 were selected as the research object. All patients with thyroid disease preoperatively received thyroid spiral CT scan, perfusion imaging and color Doppler ultrasonography, diagnosis and comparison of CT and ultrasound results and comparison of application effect in the differential diagnosis of benign and malignant thyroid lesions and imaging characteristics of spiral CT perfusion imaging.ResultsThe operation findings and pathology results was the gold standard, CT group detected thyroid benign lesions in 58 cases, 49 cases of malignant lesions, diagnosis rate was 95.54%, the diagnosis rate was significantly higher than the ultrasound group, and no significant difference compared with pathology results(P>0.05), has no statistical significance; Comparison of benign and malignant thyroid lesions of CT perfusion parameters known, benign and malignant lesions of blood volume (BV) and blood flow (BF) showed no significant difference, but the perfusion time to peak (TTP) and capillary permeability surface (PS) index comparison had the remarkable difference(P<0.05), was statistically significant.Conclusion The sensitivity and specificity for the diagnosis of thyroid diseases with high multi-slice spiral CT perfusion imaging and blood vessels, according to the pathological perfusion parameters and image difference can be accurately distinguish benign and malignant thyroid disease form, has the clinical value of application and popularization.%目的:探讨多层螺旋CT灌注成像在甲状腺疾病诊断中的临床应用价值。方法选取2011年1月~2014年12月我院收治的甲状腺疾病患者112例,作为研究对象。所有患者均以甲状腺疾病拟手术治疗术前进行甲状腺螺旋CT平扫、血管灌注成像及彩色多

  12. 320排螺旋 CT 灌注成像对小肝癌患者诊断价值的初步研究%Diagnostic Value of 320-Slice Spiral CT Perfusion Imaging in Patients with Small Hepatocellular Carcinoma

    Institute of Scientific and Technical Information of China (English)

    柳勇; 陈万洪; 马军; 董浩; 钟井松

    2014-01-01

    目的:研究320排螺旋 CT 灌注成像对小肝癌患者的诊断价值。方法对10例经手术或活检证实的小肝癌患者的 CT 表现进行回顾性分析。应用最大斜率法计算小肝癌及肿瘤以外正常肝脏组织的肝动脉血流灌注量(HAF)、门静脉血流灌注量(HPF)及灌注指数(PI),并采用色阶赋值形成灌注影像,获取感兴趣区参数图。结果小肝癌的HAF、PI 明显高于同一患者肝肿瘤以外的正常肝脏组织,HPF 明显低于同一患者肝肿瘤以外的正常肝脏组织(均 P <0.05)。结论320排 CT 灌注成像扫描范围可以覆盖整个全肝,有效地显示小肝癌灌注参数值,对难以诊断的小肝癌提供了早期诊断的依据。%Objective To investigate the diagnostic value of 320-slice spiral CT perfusion ima-ging in patients with small hepatocellular carcinoma.Methods CT findings were analyzed retro-spectively in 10 patients with small hepatocellular carcinoma confirmed by surgery or biopsy.The maximum slope method was used to calculate the hepatic arterial flow (HAF),hepatic portal flow (HPF)and perfusion index (PI)in small hepatocellular carcinoma and normal liver tissue.Furthermore, color maps for each perfusion parameter were displayed.Results Compared with normal liver tissue,the HAF and PI increased but HPF decreased in small hepatocellular carcinoma (P<0.05).Conclusion The 320-slice spiral CT whole-liver perfusion imaging can effectively display the perfusion parameters and provide a basis for early diagnosis of small hepatocellular carcinoma.

  13. 多发性大动脉炎的多层螺旋CT诊断%Diagnosis of Takayasu's arteritis with multi-slice spiral CT

    Institute of Scientific and Technical Information of China (English)

    平学军; 孟淑萍; 汪芳

    2008-01-01

    目的 分析总结多发性大动脉炎(TA)的多层螺旋CT检查方法及CT 征象,提高TA的CT诊断水平.方法 回顾性分析20例TA的多层螺旋CT检查资料,总结CT 检查方法及CT 表现并结合文献进行分析讨论.结果 按照Lupi-Herrea分类法,包括Ⅰ型5例,Ⅱ型3例,Ⅲ型12例.受累血管48支. CT 表现包括:受累血管管壁增厚48支、管腔狭窄46支、闭塞2支,2例并有血管瘤样扩张.结论 正确选择多层螺旋CT检查方法, 能够为TA的正确诊断提供可靠信息.

  14. Dynamic CT perfusion imaging of the myocardium: a technical note on improvement of image quality.

    Directory of Open Access Journals (Sweden)

    Daniela Muenzel

    Full Text Available OBJECTIVE: To improve image and diagnostic quality in dynamic CT myocardial perfusion imaging (MPI by using motion compensation and a spatio-temporal filter. METHODS: Dynamic CT MPI was performed using a 256-slice multidetector computed tomography scanner (MDCT. Data from two different patients-with and without myocardial perfusion defects-were evaluated to illustrate potential improvements for MPI (institutional review board approved. Three datasets for each patient were generated: (i original data (ii motion compensated data and (iii motion compensated data with spatio-temporal filtering performed. In addition to the visual assessment of the tomographic slices, noise and contrast-to-noise-ratio (CNR were measured for all data. Perfusion analysis was performed using time-density curves with regions-of-interest (ROI placed in normal and hypoperfused myocardium. Precision in definition of normal and hypoperfused areas was determined in corresponding coloured perfusion maps. RESULTS: The use of motion compensation followed by spatio-temporal filtering resulted in better alignment of the cardiac volumes over time leading to a more consistent perfusion quantification and improved detection of the extend of perfusion defects. Additionally image noise was reduced by 78.5%, with CNR improvements by a factor of 4.7. The average effective radiation dose estimate was 7.1±1.1 mSv. CONCLUSION: The use of motion compensation and spatio-temporal smoothing will result in improved quantification of dynamic CT MPI using a latest generation CT scanner.

  15. 急性胰腺炎肝脏灌注异常现象的多层螺旋CT表现%Multislice spiral CT manifestations of hepatic perfusion disorders in acute pancreatitis

    Institute of Scientific and Technical Information of China (English)

    温大勇; 吴惠萍; 杨晔; 伍兴友

    2011-01-01

    Objective To approach multislice spiral CT(MSCT) manifestations and mechanism of hepatic perfusion disorder ( HPD) in the patients with acute pancreatitis. Methods MSCT dynamic contrast-enhanced findings of HPD in 20 cases of acute pancreatitis were analyzed retrospectively. Results The HPD occurred single liver lobe or segment in 6 cases, simultaneously in two lobes in 12 cases and in three lobes in 2 cases. The lesions appeared as fan-shaped,wedge-shaped or patch hyperintense shadows. In 20 patients with HPD, complicated by multiple portal vein thrombosis in 3 cases, splenic vein thrombosis in 2 cases. Inhepatic portal vein thrombosis occurred at the right two branches of the portal vein, the corresponding hepatic perfusion abnormal ties were presented. There were 24 HPD areas in 13 reviewed patients, of them,18 HPDs were disappeared,the density in 3 HPDs were decreased, and a new HPD was showed in 1 case, and 2 HPDs unchanged. In 5 patients with portal vein thrombosis, the thrombus were disappeared in 4 and obviously reduced in one when reviewed. There were effusion around the pancreas in 18 and fatty liver in 5 cases. Conclusion The etiology of HPD involves a number of physiological and pathological factors, of which the reduction of the portal blood flow and hepatic arterial flow increase are the main causes.%目的 探讨急性胰腺炎肝脏灌注异常现象(hepatic perfusion disorders,HPD)的CT表现及发生机制.方法 回顾性分析20例急性胰腺炎发生HPD的多层螺旋CT动态增强扫描各期图像,并对复查病例影像变化进行比较.结果 20例中HPD发生于单个肝叶(或段)者6例,同时发生于2个肝叶(或段)者12例,同时发生于3个肝叶(或段)者2例.CT表现为楔形、扇形或片状高密度影.20例中并发肝内、外多发门静脉系统血栓3例,脾静脉血栓2例,其中肝内门静脉血栓均位于肝右叶门静脉2级分支,相应肝段均发生HPD.13例复查病例中共24处HPD有18处消失,3

  16. Automatic extraction of forward stroke volume using dynamic PET/CT

    DEFF Research Database (Denmark)

    Harms, Hans; Tolbod, Lars Poulsen; Hansson, Nils Henrik;

    Background: Dynamic PET can be used to extract forward stroke volume (FSV) by the indicator dilution principle. The technique employed can be automated and is in theory independent on the tracer used and may therefore be added to any dynamic cardiac PET protocol. The aim of this study was to vali......Background: Dynamic PET can be used to extract forward stroke volume (FSV) by the indicator dilution principle. The technique employed can be automated and is in theory independent on the tracer used and may therefore be added to any dynamic cardiac PET protocol. The aim of this study...... was to validate automated methods for extracting FSV directly from dynamic PET studies for two different tracers and to examine potential scanner hardware bias. Methods: 21 subjects underwent a dynamic 27 min 11C-acetate PET scan on a Siemens Biograph TruePoint 64 PET/CT scanner (scanner I). In addition, 8...... subjects underwent a dynamic 6 min 15O-water PET scan followed by a 27 min 11C-acetate PET scan on a GE Discovery ST PET/CT scanner (scanner II). The LV-aortic time-activity curve (TAC) was extracted automatically from dynamic PET data using cluster analysis. The first-pass peak was isolated by automatic...

  17. Ventilation imaging of the paranasal sinuses using xenon-enhanced dynamic single-energy CT and dual-energy CT: a feasibility study in a nasal cast.

    Science.gov (United States)

    Thieme, Sven F; Möller, Winfried; Becker, Sven; Schuschnig, Uwe; Eickelberg, Oliver; Helck, Andreas D; Reiser, Maximilian F; Johnson, Thorsten R C

    2012-10-01

    To show the feasibility of dual-energy CT (DECT) and dynamic CT for ventilation imaging of the paranasal sinuses in a nasal cast. In a first trial, xenon gas was administered to a nasal cast with a laminar flow of 7 L/min. Dynamic CT acquisitions of the nasal cavity and the sinuses were performed. This procedure was repeated with pulsating xenon flow. Local xenon concentrations in the different compartments of the model were determined on the basis of the enhancement levels. In a second trial, DECT measurements were performed both during laminar and pulsating xenon administration and the xenon concentrations were quantified directly. Neither with dynamic CT nor DECT could xenon-related enhancement be detected in the sinuses during laminar airflow. Using pulsating flow, dynamic imaging showed a xenon wash-in and wash-out in the sinuses that followed a mono-exponential function with time constants of a few seconds. Accordingly, DECT revealed xenon enhancement in the sinuses only after pulsating xenon administration. The feasibility of xenon-enhanced DECT for ventilation imaging was proven in a nasal cast. The superiority of pulsating gas flow for the administration of gas or aerosolised drugs to the paranasal sinuses was demonstrated. • Ventilation of the paranasal sinuses is poorly understood. • Dual-energy CT ventilation imaging has been explored using phantom simulation. • Xenon can be seen in the paranasal sinuses using pulsating xenon flow. • Dual-energy CT uses a lower radiation dose compared with dynamic ventilation CT.

  18. Assessing Tumor Response to Treatment in Patients with Lung Cancer Using Dynamic Contrast-Enhanced CT

    DEFF Research Database (Denmark)

    Strauch, Louise S; Eriksen, Rie Ø; Sandgaard, Michael

    2016-01-01

    after treatment. Four out of five studies that measured blood flow post anti-angiogenic treatments found that blood flow was significantly decreased. DCE-CT may be a useful tool in assessing treatment response in patients with lung cancer. It seems that particularly permeability and blood flow......The aim of this study was to provide an overview of the literature available on dynamic contrast-enhanced computed tomography (DCE-CT) as a tool to evaluate treatment response in patients with lung cancer. This systematic review was compiled according to Preferred Reporting Items for Systematic...... Reviews and Meta-Analyses (PRISMA) guidelines. Only original research articles concerning treatment response in patients with lung cancer assessed with DCE-CT were included. To assess the validity of each study we implemented Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). The initial search...

  19. 64排螺旋CT灌注成像对前列腺癌的诊断价值研究%Study on Diagnostic Value of 64 - multidetector Spiral CT Perfusion Imaging in Prostate Carcinoma

    Institute of Scientific and Technical Information of China (English)

    殷少龙; 许庆森; 赵春龙; 武迎军; 冯庆韬

    2012-01-01

    目的 探讨64排螺旋CT灌注成像对前列腺癌(PCa)的诊断价值. 方法 选择2006年8月-2010年5月张家口市第一医院确诊的前列腺癌患者62例,另选择正常前列腺15例为对照组.两组均行64排螺旋CT灌注成像技术检查,对比两组灌注参数之间的差异. 结果 对照组正常前列腺中央带和周围带的CT灌注参数比较,中央带明显高于周围带(P<0.05).正常对照组(周围带)和PCa组的CT灌注参数比较,PCa组的BF、BV、PS明显高于对照组(周围带)(P<0.05),MTT、TTP值明显小于对照组(周围带)(P<0.05).对照组TDC曲线呈缓升-平台型,PCa组TDC曲线呈速升-缓降型. 结论 64排螺旋CT灌注成像对PCa具有重要的诊断价值,其中BF、PS、TTP对PCa的评价意义最大,能更准确反映肿瘤的血管生成,可以作为临床诊断PCa的有效普查方法.%Objective To explore the value of 54 - multidetector spiral CT perfusion imaging in diagnosis of prostate carcinoma (PCa). Methods Sixty- two patients with PCa confirmed by the First Hospital of Zhangjiakou City from August 2006 to May 2010 were selected as PCa group, and another 15 healthy individuals were served as the control group. 64 - multidetector spiral CT perfusion imaging was performed on all objects of the study. The differences in the perfusion parameters of the two groups, including mean blood flow (BF), blood volume (BV), time to peak (TTP), mean transit time (MTT), capillary permeability - surface (PS), time-density curve (TDC) were documented and compared. Results In the control group, the perfusion parameters of the central zone were significantly higher than those in the peripheral zone (P < 0.05). Compared with the perfusion parameters of the peripheral zone of the control group, BF, BV and PS of Pca group were significantly higher than those in the control group (P<0.05), while TTP and MTT were significantly less than those in the control group (P< 0.05). Time - density curve of the

  20. 64层螺旋CT对寰椎椎动脉沟环综合征的诊断价值%The diagnostic value of 64-slice spiral CT on atlas vertebral artery sulcus ring syndrome

    Institute of Scientific and Technical Information of China (English)

    路明; 陈穹; 汪茂文; 王钢; 陈小昕; 虞鲲

    2012-01-01

    目的 探讨64层螺旋CT对寰椎椎动脉沟环综合征的诊断价值.方法 收集因常规颈椎正侧位X线检查发现的寰椎椎动脉沟环患者48例,进行64层螺旋CT容积扫描后,进行容积重建和多平面重建,多方位显示寰椎结构形态及寰枢关节间隙,并探讨其与临床症状之间的关系.结果 48例寰椎椎动脉沟环患者中,右侧完整环型24例,孔径(6.59±0.50)mm,左侧完整环型36例,孔径(6.19±0.49)mm,右侧不完整环型24例,左侧不完整环型12例.30例诊断为寰椎椎动脉沟环综合征,均有寰枢关节不稳及不同程度头颈转动性眩晕症状.结论 64层螺旋CT能清晰显示寰椎后弓桥的解剖结构和测量寰椎椎动脉沟环的孔径,结合对枕颈失稳的判断,对寰椎椎动脉沟环综合征具有重要的诊断价值.%Objective To explore the diagnostic value of 64-slice spiral CT on atlas vertebral artery sulcus ring syndrome.Methods The 48 atlas vertebral artery sulcus ring patients who were found by conventional anterior posterior and lateral X-ray film were collected.The 64-slice spiral CT volume scan and following volume restitution(V R)and multiplanar reconstruction(MPR)were underwent,and multi-directional structural morphology was displayed.Their relationship with clinical features were analyzed.Results Among 48 cases of atlas vertebral artery sulcus ring,24 cases were shown with right complete bridge[pore size(6.59±0.50)mm],36 cases with left complete bridge[pore size(6.19±0.49)mm],24 cases with right incomplete bridge and 12 cases with left incomplete bridge.Thirty cases were diagnosed as atlas vertebral artery sulcus ring syndrome,and all had the atlantoaxial joint asymmetry and vertigo of different degree when head and neck rotated.Conclusions The 64-slice spiral CT can clearly display the anatomical features of posterior bridge of atlas and measure the pore size of atlas vertebral artery sulcus ring,and it has important diagnostic value for atlas

  1. 螺旋CT诊断和鉴别诊断急性腹痛的价值研究%Value Study on Spiral CT in Diagnosis and Identiifcation of Acute Abdominal Pain

    Institute of Scientific and Technical Information of China (English)

    令狐玲珍; 张磊; 薛育红; 李圣博

    2016-01-01

    目的:观察研究螺旋CT诊断和鉴别诊断急性腹痛的价值。方法选取2013年1月至2015年1月来我院就诊的急性腹痛患者共62例,作为研究对象,将所有患者随机分为观察组和对照组,31名对照组患者采用传统B超方法诊断鉴别,31名观察组患者予以螺旋CT诊断鉴别,比较两组患者的诊断效果。结果31例对照组患者中有11例为阑尾炎,4例为阑尾粘液囊肿,5例为盲肠憩室炎,5例为盲、升结肠癌,3例为卵巢平滑肌瘤,3例为卵巢纤维瘤,31例观察组患者13例为阑尾炎,3例为阑尾粘液囊肿,6例为盲肠憩室炎,6例为盲、升结肠癌,2例为卵巢平滑肌瘤,1例为卵巢纤维瘤。观察组患者的诊断准确率为100.0%,对照组患者的诊断准确率为87.1%,两组患者比较有统计学意义(P <0.05)。结论在急性腹痛诊断中应用螺旋CT进行诊断鉴别,可有效提升检查准确率,利于患者后期的治疗,值得在临床上大力推广。%Objective to observe and study spiral CT in diagnosis and identification of acute abdominal pain.Methods choose 62 cases acute abdominal pain patiens in our hospital from January 2013 to January 2015 as study objects, randomly divide them into observation and control group, 31 cases in control group were treated with traditional methods B-ultrasound diagnosis, and 31 cases in observation group with spiral CT differential diagnosis. Compare diagnosis effect of two groups.Results among 31 cases of control group, there were 11 cases appendicitis, 4 cases appendix mucus cyst, 5 cases caecal diverticulitis, 5 cases cecal ascending colon cancer, 3 cases ovarian leiomyoma, 3 cases ovarian fibroma. And among 31 cases in observation group, there were 13 cases appendicitis, 3 cases mucocele of the appendix, 6 cases diverticulitis of cecum, 6 cases cecal ascending colon cancer, 2 cases ovarian leiomyoma and 1 case ovarian fibroma. Diagnostic accuracy rate of

  2. The application value of 64-slice spiral CT in the diagnosis of occult rib fracture%64层螺旋CT在隐匿性肋骨骨折诊断中的应用价值

    Institute of Scientific and Technical Information of China (English)

    迟宝权; 刘亚静; 康洁

    2011-01-01

    Objective To evaluate the diagnostic value of 64-slice spiral CT and post-reconstruction technique in the diagnosis of occult rib fracture. Methods 42 patients with suspected chest trauma and occult rib fracture were examined by 64-slice spiral CT scan. All the original images were transferred to workstation to be post-processed to obtain volume rendering ( VR ) , maximum intensity projection ( MIP), multiplanar reformation (MPR) ,curved planar reformation(CPR) images in order to reveal occult rib fractures clearly. The abilities in displaying occult rib fractures were compared among VR, MIP, MPR, and CPR. Results The comprehensive application of various reconstruction techniques could show clearly the different parts and different types of occult rib fractures. The CPR reconstruction was the best one of them in displaying occult rib fractures,as compared with MPR and VR. A total of 59 parts of occult rib fracture were diagnosed in 42 patients with chest trauma. Conclusion The 64-slice spiral CT and post-reconstruction technique to treat the images can show clearly occult rib fracture, and can meet the positioning and qualitative analysis for occult fracture ribs,so which is the preferred method for detecting occult rib fracture.%目的 探讨64层螺旋CT及其后重建技术在隐匿性肋骨骨折诊断中的临床应用价值.方法 对42例胸部外伤考虑隐匿性肋骨骨折患者,进行64层螺旋CT平扫,将所得原始数据经工作站进行图像后处理,获得容积再现(VR),最大密度投影(MIP),多平面重组(MPR)、曲面重建(CPR)图像.并比较各种重建图像对隐匿性骨折的显示能力.结果 综合运用各种后重建技术,可清晰显示不同部位、不同类型肋骨隐匿性骨折.重建以CPR技术显示效果最佳,MPR、VR次之.42例胸部外伤患者共确诊59处肋骨隐匿性骨折.结论 64层螺旋CT及其后重建技术图像显示清晰,满足对肋骨隐匿性骨折进行定位、定性分析,是肋骨隐匿性骨折检查首选方法.

  3. Type of spiral wave with trapped ions.

    Science.gov (United States)

    Li, Yuting; Li, Haihong; Zhu, Yun; Zhang, Mei; Yang, Junzhong

    2011-12-01

    Pattern formation in ultracold quantum systems has recently received a great deal of attention. In this work, we investigate a two-dimensional model system simulating the dynamics of trapped ions. We find a spiral wave that is rigidly rotating, but with a peculiar core region in which adjacent ions oscillate in antiphase. The formation of this spiral wave is ascribed to the excitability previously reported by Lee and Cross. The breakup of the spiral wave is probed and, especially, an extraordinary scenario of the disappearance of the spiral wave, caused by spontaneous expansion of the antiphase core, is unveiled.

  4. Analysis of Value of Dual-sliceSpiralCT in Diagnosis of Liver Abscess%分析双排螺旋CT对肝脓肿的诊断价值

    Institute of Scientific and Technical Information of China (English)

    王海军

    2016-01-01

    目的:分析在肝脓肿的诊断中双排螺旋CT的应用价值,为提高肝脓肿的诊断正确率提供借鉴依据。方法择取32例肝脓肿患者的临床资料实施回顾性分析,对其CT平扫、增强扫描表现进行分析和总结,并对比CT检查结果和病理检查结果。结果32例肝脓肿患者的CT检查结果和病理检查结果不存在明显的统计学差异(P>0.05)。肝脓肿患者中单发者、肝右叶者居多,脓肿直径为1.42~15.6cm。32例肝脓肿患者均存在低密度区,且均比周围正常肝实质组织密度要低得多。CT值达到8~28Hu。29例边缘模糊,其余边缘清晰明了。3例能够观察到程度不同的气液平面。20例患者中央有坏死液化区存在,病灶呈“环靶征”,其中4例单环征,11例双环征,5例三环征。此外,9例患者的病灶呈花瓣征,3例患者腔内无强化。不同类型肝脓肿的征象有所不同。结论在肝脓肿的诊断中应用双排螺旋CT,可以获得比较高的诊断正确率,为临床诊治肝脓肿提供一定的借鉴依据,临床应用价值值得认可。%Objective To analyze the application value of dual-slice spiral CT in the diagnosis of liver abscess ,in order to provide a refer-ence for improving the correct accuracy the of dual-slice spiral CT in diagnosis of Liver abscess.MethodThe clinical data of 32 cases of liver abscess were retrospectively analyzed.TheirCT plain scan and enhanced scan findings were analyzed and summarized.The results of CT ex-amination and pathological examination were compared.Result There were no significant statistical differences in the results of CT examina-tion and pathological examination in 32 cases of liver abscess (P>0.05).In patients with liver abscess,single onset andlobi hepatis dexter were the most, and the diameter of the abscess is 1.42~ 15.6cm. 32 cases of liver abscess patients had low density areas, and were much lower than the normal liver parenchyma. CT

  5. The Comparison of Diagnostic Value of X-ray and Spiral CT for Sacroiliac Joint in Ankylosing Spondylitis%X线平片和螺旋CT对强直性脊柱炎骶髂关节病变的诊断价值比较

    Institute of Scientific and Technical Information of China (English)

    陈一明

    2014-01-01

    目的:研究X线平片和螺旋CT分别诊断强直性脊柱炎骶髂关节病变的效果。方法:选择2011年3月-2014年3月笔者所在医院收治的45例强直性脊柱炎骶髂关节病变的患者。分别对患者进行X线和螺旋CT两种影像学检查。检查后,记录分析两种检查手段对骶髂关节病变的诊断分级情况,并比较分析两种检查手段对骶髂关节病变各类征象的检出率。结果:螺旋CT对0~Ⅱ级骶髂关节病变(早期病变)的诊断效果明显优于X线,X线对Ⅲ~Ⅳ级患者的诊断与螺旋CT偏差较小。X线对关节面模糊的检出率(30.00%)明显高于螺旋CT(15.56%),两种检出率比较差异有统计学意义(χ2=7.6610,P=0.0056);螺旋CT对关节软骨及骨侵蚀的检出率(66.67%)明显高于X线(51.11%),两种检出率比较差异有统计学意义(χ2=4.4977,P=0.0339)。结论:螺旋CT对早期强直性脊柱炎骶髂关节病变的诊断效果优于X线,X线和螺旋CT对中晚期强直性脊柱炎骶髂关节病变诊断的敏感性相同。%Objective:To study the diagnosis effect of X-ray and spiral CT for sacroiliac joint in ankylosing spondylitis.Method:45 cases with sacroiliac joint in ankylosing spondylitis from March 2011 to March 2014 in our hospital were studied.All the patients were examined with X-ray and spiral CT.After checking,the diagnostic hierarchical situation of the two methods were recorded and analyzed and sacroiliac joint detection rate of all types of signs were compared. Result:The diagnostic effect of spiral CT 0-Ⅱgrade sacroiliac joint(early lesions ) was better than X-ray,the deviation of X-ray and spiral CT for patients with stageⅢ-Ⅳdiagnosis was small.X-ray of the articular surface of the fuzzy detection rate(30.00%) was significantly higher than that of spiral CT(15.56%),there was significant difference (χ2=7.6610,P=0.0056),spiral CT of articular cartilage and bone erosion detection rate(66.67%) was significantly

  6. Quantum spirals

    CERN Document Server

    Yoshida, Z

    2016-01-01

    Quantum systems often exhibit fundamental incapability to entertain vortex. The Meissner effect, a complete expulsion of the magnetic field (the electromagnetic vorticity), for instance, is taken to be the defining attribute of the superconducting state. Superfluidity is another, close-parallel example; fluid vorticity can reside only on topological defects with a limited (quantized) amount. Recent developments in the Bose-Einstein condensates produced by particle traps further emphasize this characteristic. We show that the challenge of imparting vorticity to a quantum fluid can be met through a nonlinear mechanism operating in a hot fluid corresponding to a thermally modified Pauli-Schroedinger spinor field. In a simple field-free model, we show that the thermal effect, represented by a nonlinear, non-Hermitian Hamiltonian, in conjunction with spin vorticity, leads to new interesting quantum states; a spiral solution is explicitly worked out.

  7. 高速弧齿锥齿轮动态啮合质量优化%OPTIMIZATION OF DYNAMIC MES