BACKGROUND Posterior malleolar fractures have been reported to occur in<40%of ankle fractures.AIM To reveal the recurrent patterns and characteristics of posterior malleolar fractures by creating fracture maps of t...BACKGROUND Posterior malleolar fractures have been reported to occur in<40%of ankle fractures.AIM To reveal the recurrent patterns and characteristics of posterior malleolar fractures by creating fracture maps of the posterior malleolar fractures through the use of computed tomography mapping.METHODS A consecutive series of posterior malleolar fractures was used to create threedimensional reconstruction images,which were oriented and superimposed to fit an ankle model template by both aligning specific biolandmarks and reducing reconstructed fracture fragments.Fracture lines were found and traced in order to generate an ankle fracture map.RESULTS This study involved 112 patients with a mean age of 49,comprising 32 pronationexternal rotation grade IV fractures and 80 supination-external rotation grade IV fractures according to the Lauge-Hansen classification system.Three-dimensional maps showed that the posterior ankle fracture fragments in the supinationexternal rotation grade IV group were relatively smaller than those in the pronation-external rotation grade IV group after posterior malleolus fracture.In addition,the distribution analyses on posterior malleolus fracture lines indicated that the supination-external rotation grade IV group tended to have higher linear density but more concentrated and orderly distribution fractures compared to the pronation-external rotation grade IV group.CONCLUSION Fracture maps revealed the fracture characteristics and recurrent patterns of posterior malleolar fractures,which might help to improve the understanding of ankle fracture as well as increase opportunities for follow-up research and aid clinical decision-making.展开更多
BACKGROUND Situs inversus totalis(SIT)is a rare congenital condition that is characterized by a complete mirror image of the typical arrangement of the thoracic and abdominal viscera.Performing thoracoscopic segmentec...BACKGROUND Situs inversus totalis(SIT)is a rare congenital condition that is characterized by a complete mirror image of the typical arrangement of the thoracic and abdominal viscera.Performing thoracoscopic segmentectomy for a patient with lung cancer and SIT is an extremely skilled and challenging surgical procedure.CASE SUMMARY A 41-year old woman with a medical history of dextrocardia since childhood was admitted to our hospital with a mixed ground-glass opacity(mGGO)in her left lung field,discovered by computed tomography during her health checkup.In order to facilitate surgical orientation,three-dimensional computed tomography bronchography and angiography(3D-CTBA)was preoperatively carried out.The result of 3D-CTBA was consistent with the diagnosis of SIT and an mGGO in the posterior segment of the left upper lobe(LS2).Surgery was conducted in accordance with preoperative 3D-CTBA and designed surgical procedure,combined with intraoperative navigation.Final pathological examination revealed in situ adenocarcinoma.The patient’s postoperative condition was uneventful and no complications were observed.CONCLUSION We present the first case of lung cancer in a patient with SIT who successfully underwent thoracoscopic segmentectomy assisted by 3D-CTBA.This is a new technique that covers precise confirmation and dissection of targeted structures and intersegmental demarcation,and can help achieve a meticulous anatomical segmentectomy.展开更多
The geometric and spatial characteristics of pore structures determine the permeability and water retention of soils, which have important effects on soil functional diversity and ecological restoration. Until recentl...The geometric and spatial characteristics of pore structures determine the permeability and water retention of soils, which have important effects on soil functional diversity and ecological restoration. Until recently, there have not been tools and methods to visually and quantitatively describe the characteristics of soil pores. To solve this problem, this research reconstructs the geometry and spatial distribution of soil pores by the marching cubes method, texture mapping method and the ray casting method widely used in literature. The objectives were to explore an optimal method for three-dimensional visualization of soil pore structure by comparing the robustness of the three methods on soil CT images with single pore structure and porosity ranging from low (2–5%) to high (12–18%), and to evaluate the reconstruction performance of the three methods with different geometric features. The results demonstrate that there are aliases (jagged edges) and deficiency at the boundaries of the model reconstructed by the marching cubes method and pore volumes are smaller than the ground truth, whereas the results of the texture mapping method lack the details of pore structures. For all the soil images, the ray casting method is preferable since it better preserves the pore characteristics of the ground truth. Furthermore, the ray casting method produced the best soil pore model with higher rendering speed and lower memory consumption. Therefore, the ray casting method provides a more advanced method for visualization of pore structures and provides an optional technique for the study of the transport of moisture and the exchange of air in soil.展开更多
To correct a lower limb deformity, orthopedic surgeons must have an exact understanding of the deformity. In general, preoperative planning is carried out using anterior-posterior (AP) and lateral radiographs. However...To correct a lower limb deformity, orthopedic surgeons must have an exact understanding of the deformity. In general, preoperative planning is carried out using anterior-posterior (AP) and lateral radiographs. However, for severe cases with a combination of angular and rotational deformities of the lower limb, obtaining true AP and lateral radiographs is difficult and accurate calculation of the rotational deformity from radiographs is impossible. In this report, we propose to focus on preoperative assessment using three-dimensional (3D) reconstruction images of computed tomography (CT) scans for severe lower limb deformity in a patient with bilateral fibular hemimelia type II according to the Achterman- Kalamchi classification. She underwent bifocal deformity corrections of the bilateral tibiae using Taylor spatial frames in combination with the Ilizarov external fixator. Complete bony union was achieved, without angular deformity or limb length discrepancy.展开更多
AIM To evaluate usefulness of single photon emission computed tomography(SPECT) with three-dimensional stereotactic surface projection(3D-SSP) in distinguishing between Alzheimer's disease(AD) and depression.METHO...AIM To evaluate usefulness of single photon emission computed tomography(SPECT) with three-dimensional stereotactic surface projection(3D-SSP) in distinguishing between Alzheimer's disease(AD) and depression.METHODS We studied 43 patients who presented with both depressive symptoms and memory disturbance. Each subject was evaluated using the following:(1) the Minimal Mental State Examination;(2) the Hamilton Rating Scale for Depression;(3) Clinical Global Impression-Severity scale(CGI-S); and(4) SPECT imaging with 3D-SSP.RESULTS The MMSE scores correlated significantly with the maximum Z-scores of AD-associated regions. CGI-S scores correlated significantly with the maximum Z-scores of depression-associated regions. Factor analysis identified three significant factors. Of these, Factor 1 could be interpreted as favouring a tendency for AD, Factor 2 as favouring a tendency for pseudo-dementia, and Factor 3 as favouring a depressive tendency.CONCLUSION We investigated whether these patients could be categorized as types: Type A(true AD), Type B(pseudodementia), Type C(occult AD), and Type D(true depression). The factor scores in factor analysis supported the validity of this classification. Our results suggest that SPECT with 3D-SSP is highly useful for distinguishing between depression and depressed mood in the early stage of AD.展开更多
AIM: To evaluate the usefulness of three-dimensional computed tomography (3DCT) in laparoscopic surgery for colorectal carcinoma.METHODS: Seventy-two patients with colorectal cancer who underwent curative operation at...AIM: To evaluate the usefulness of three-dimensional computed tomography (3DCT) in laparoscopic surgery for colorectal carcinoma.METHODS: Seventy-two patients with colorectal cancer who underwent curative operation at our hospital were enrolled in this study. They were classified into two groups by operative procedures. Sixteen patients underwent laparoscopic surgery, laparoscopic group (LG),while 56 patients underwent conventional open surgery,open group (OG). At our institution, contrast-enhanced CT is routinely performed as part of intra-abdominal screening and the 3D images of the major regional vessels are described. We have previously described about the preoperative visualization of the inferior mesenteric artery (IMA) by 3DCT. This time we newly acquired 3D images of the superior mesenteric artery (SMA)/superior mesenteric vein (SMV), ileocecal artery(ICA), middle colic artery (MCA), and inferior mesenteric vein (IMV). We have compared our two study groups with regard to five items, including clinical anastomotic leakage. We have discussed here the role of 3DCT in laparoscopic surgery for colorectal carcinoma.RESULTS: The mean length of the incision inLG was4.625±0.89 cm, which was significantly shorter than that in OG (P<0.001). The association between ICA and SMV and SMA was described in the right-sided colectomy. The preoperative imaging of IMA and IMV was created in the rectosigmoidectomy. There was no significant difference in anastomotic leakage between the two groups, but no patients in LG experienced anastomotic leakage.CONCLUSION: Most of the patients are satisfied with the shorter incisional length following laparoscopic surgery. Preoperative visualization of the major regional vessels may be helpful for the secure treatment of the anastomosis in laparoscopic surgery for colorectal carcinoma.展开更多
Aero-engine hollow turbine blades are work under prolonged high temperature,requiring high dimensional accuracy.Blade profile and wall thickness are important parameters to ensure the comprehensive performance of blad...Aero-engine hollow turbine blades are work under prolonged high temperature,requiring high dimensional accuracy.Blade profile and wall thickness are important parameters to ensure the comprehensive performance of blades,which need to be measured accurately during manufacturing process.In this study,a high accuracy industrial computed tomography(ICT)measuring method was developed based on standard cylindrical pin and ring workpieces of different sizes.Combining ICT with cubic spline interpolation,a sub-pixel accuracy was achieved in measuring the dimension of component.Compared with the traditional and whole-pixel level image measurement method,the cubic spline interpolation algorithm has the advantages of high accuracy in image edge detection and thus high accuracy of dimensional measurement.Further,the technique was employed to measure the profile and wall thickness of a typical aerospace engine turbine blade,and an accuracy higher than 0.015 mm was obtained.展开更多
Crohn's disease,a transmural inflammatory bowel disease,remains a difficult entity to diagnose clinically.Over the last decade,multidetector computed tomography(CT) has become the method of choice for noninvasive ...Crohn's disease,a transmural inflammatory bowel disease,remains a difficult entity to diagnose clinically.Over the last decade,multidetector computed tomography(CT) has become the method of choice for noninvasive evaluation of the small bowel,and has proved to be of significant value in the diagnosis of Crohn's disease.Advancements in CT enterography protocol design,three dimensional(3-D) post-processing software,and CT scanner technology have allowed increasing accuracy in diagnosis,and the acquisition of studies at a much lower radiation dose.The cases in this review will illustrate that the use of 3-D technique,proper enterography protocol design,and a detailed understanding of the different manifestations of Crohn's disease are all critical in properly diagnosing the full range of possible complications in Crohn's patients.In particular,CT enterography has proven to be effective in identifying involvement of the small and large bowel(including active inflammation,stigmata of chronic inflammation,and Crohn's-related bowel neoplasia) by Crohn's disease,as well as the extra-enteric manifestations of the disease,including fistulae,sinus tracts,abscesses,and urologic/hepatobiliary/osseous complications.Moreover,the proper use of 3-D technique(including volume rendering and maximum intensity projection) as a routine component of enterography interpretation can play a vital role in improving diagnostic accuracy.展开更多
Background: 4D-CT has been used to localize the parathyroid adenomas and hyperplasia since 2006 as a second line study after TC-99 m MIBI and ultrasonography. However, multiple studies have shown that 4D-CT is a robus...Background: 4D-CT has been used to localize the parathyroid adenomas and hyperplasia since 2006 as a second line study after TC-99 m MIBI and ultrasonography. However, multiple studies have shown that 4D-CT is a robust imaging method with high diagnostic accuracy, becoming increasingly popular among surgeons and radiologists. Purpose: To assess the diagnostic performance of 4D-CT scans to identify the pathologic gland(s), using pathology and intraoperative findings as gold standards. Methods: We analyzed patients with primary and secondary hyperparathyroidism who had intraoperative reports, pathology, parathyroid hormone levels, and preoperative 4D-CT. Histology, surgical findings, and decreased parathyroid hormone levels were used as gold standards. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy and 95% confidence interval were calculated. Fleiss’ kappa was used to assess the inter-observer agreement. Results: Sixty-seven patients were included. Sixty-two patients had a single adenoma, and five patients had a multiple gland disease (adenomas or hyperplasia). A total of 72 glands were proven to have parathyroid adenomas or hyperplasia. The sensitivity, specificity, PPV, NPV and accuracy are 85%, 97%, 96%, 87% and 91% for lateralization and 76%, 96%, 85%, 92% and 90% for quadrant localization, respectively in single-gland disease. The sensitivity, specificity, PPV, NPV and accuracy are 88%, 100%, 100%, 50% and 90% for lateralization and 71%, 100%, 100%, 60% and 80% for quadrant localization respectively in multiple-gland disease. Fleiss’ kappa value is 5.6 (moderate inter-observer agreement). Conclusion: 4D-CT is a robust method in the localization of hyperfunctioning parathyroid glands with high accuracy and at least moderate inter-observer agreement.展开更多
Objective:To investigate the feasibility of a 4D-CT reconstruction method based on the similarity principle of spatial adjacent images and mutual information measure. Methods:A motor driven sinusoidal motion platform ...Objective:To investigate the feasibility of a 4D-CT reconstruction method based on the similarity principle of spatial adjacent images and mutual information measure. Methods:A motor driven sinusoidal motion platform made in house was used to create one-dimensional periodical motion that was along the longitudinal axis of the CT couch. The amplitude of sinusoidal motion was set to an amplitude of ±1 cm. The period of the motion was adjustable and set to 3.5 s. Phantom objects of two eggs were placed in a Styrofoam block, which in turn were placed on the motion platform. These objects were used to simulate volumes of interest undergoing ideal periodic motion. CT data of static phantom were acquired using a multi-slice general electric (GE) LightSpeed 16-slice CT scanner in an axial mode. And the CT data of periodical motion phantom were acquired in an axial and cine-mode scan. A software program was developed by using VC++ and VTK software tools to resort the CT data and reconstruct the 4D-CT. Then all of the CT data with same phase were sorted by the program into the same series based on the similarity principle of spatial adjacent images and mutual information measure among them, and 3D reconstruction of different phase CT data were completed by using the software. Results:All of the CT data were sorted accurately into different series based on the similarity principle of spatial adjacent images and mutual information measures among them. Compared with the unsorted CT data, the motion artifacts in the 3D reconstruction of sorted CT data were reduced significantly, and all of the sorted CT series result in a 4D-CT that reflected the characteristic of the periodical motion phantom. Conclusion:Time-resolved 4D-CT reconstruction can be implemented with any general multi-slice CT scanners based on the similarity principle of spatial adjacent images and mutual information measure.The process of the 4D-CT data acquisition and reconstruction were not restricted to the hardware or software of the CT scanner and has the feasibility ,which extensive applicability.展开更多
To evaluate the feasibility and accuracy of a three-dimensional augmented reality system incorporating integral videography for imaging oral and maxillofacial regions, based on preoperative computed tomography data. T...To evaluate the feasibility and accuracy of a three-dimensional augmented reality system incorporating integral videography for imaging oral and maxillofacial regions, based on preoperative computed tomography data. Three-dimensional surface models of the jawbones, based on the computed tomography data, were used to create the integral videography images of a subject's maxillofacial area. The three-dimensional augmented reality system (integral videography display, computed tomography, a position tracker and a computer) was used to generate a three-dimensional overlay that was projected on the surgical site via a half-silvered mirror. Thereafter, a feasibility study was performed on a volunteer. The accuracy of this system was verified on a solid model while simulating bone resection. Positional registration was attained by identifying and tracking the patient/surgical instrument's position. Thus, integral videography images of jawbones, teeth and the surgical tool were superimposed in the correct position. Stereoscopic images viewed from various angles were accurately displayed. Change in the viewing angle did not negatively affect the surgeon's ability to simultaneously observe the three-dimensional images and the patient, without special glasses. The difference in three-dimensional position of each measuring point on the solid model and augmented reality navigation was almost negligible (〈1 mm); this indicates that the system was highly accurate. This augmented reality system was highly accurate and effective for surgical navigation and for overlaying a three-dimensional computed tomography image on a patient's surgical area, enabling the surgeon to understand the positional relationship between the preoperative image and the actual surgical site, with the naked eye.展开更多
Objective:To investigate the influences of motion artifacts on three-dimensional (3D) reconstruction volume and conformal radiotherapy planning. Methods:A phantom which can mimic the clip motion of lung tumor along th...Objective:To investigate the influences of motion artifacts on three-dimensional (3D) reconstruction volume and conformal radiotherapy planning. Methods:A phantom which can mimic the clip motion of lung tumor along the cranial-caudal direction is constructed by step motor, small ball of polyethylene and potato. Ten different scan protocols were set and CT data of the phantom were acquired by using a commercial GE LightSpeed16 CT scanner. The 3D reconstruction of the CT data was implemented by adopting volume-rendering technology of GE AdvantageSim 6.0 system. The reconstructed volumes of each target in different scan protocols were measured through 3D measuring tools. Thus, relative deviations of the reconstruction volumes between moving targets and static ones were determined. The three-dimensional conformal radiation therapy (3D-CRT) plans and conformal fields were created and compared for a static/moving target with the WiMRT treatment planning system (TPS). Results:For a static target, there was no obvious difference among the 3D reconstruction volumes when the CT data were acquired with different pitches and slices. The appearance of 3D reconstruction volume and 3D conformal field of a moving target was quite different from that of static one. The maximum relative deviation is nearly 90% for a moving target scanned with different scan protocols. The relative deviations are variable among the different targets, about from -39.8% to 89.5% for a smaller target and from -18.4% to 20.5% for a larger one. Conclusion:The motion artifacts have great effects on 3D-CRT planning and reconstruction volume, which will greatly induce distorted conformal radiation fields and false DVHs for a moving target.展开更多
Multi-detector row computed tomography urography (MDCTU) becomes the imaging modality of choice for evaluation of the kidneys and urinary tract. The aim of this study was to discuss and illustrate the role of MDCTU, o...Multi-detector row computed tomography urography (MDCTU) becomes the imaging modality of choice for evaluation of the kidneys and urinary tract. The aim of this study was to discuss and illustrate the role of MDCTU, on a 32-row CT scanner in the evaluation a variety of entities that were frequently associated with microscopic hematuria in adults. This prospective cohort study was performed in the period of August 2013 to October 2014. Fifty positive participants to microscopic hematuria were examined at the radiology department of Alnilin Diagnostic Medical Center and Antalya Medical Center. Computed tomography urography (CTU) scanning was performed using two powerful performances, high speed multi-detector row on 32-row CT scanners (Siemens Healthcare Global, Somatom Emotion Duo Eco). Statistical analysis was done through the standard Statistical Package for the Social Sciences (SPSS Inc., Chicago, IL, USA) version 15 for windows. MDCTU established the correct cause of microscopic hematuria in (44;88%) of participants. In (6;12%) of participants, no cause of hematuria was identified based on the standard of references. The causes of hematuria in (41;82%) participants were diseases in the upper urinary tract, while urinary bladder neoplasms (2;4%) and diverticulum (1;2%) were the causes of hematuria (3;6%) in the lower urinary tract. Thirty two-row MDCTU scanner demonstrated satisfactory results in the investigation of microscopic hematuria, being able to demonstrate a wide spectrum of diseases affecting the urinary tract is the main advantage of the technique.展开更多
As precise positioning of ankle radiography is not possible, quantitative measurement of all syndesmotic parameters on repeated ankle X-ray films may be of little value. The purpose of this study was to provide a set ...As precise positioning of ankle radiography is not possible, quantitative measurement of all syndesmotic parameters on repeated ankle X-ray films may be of little value. The purpose of this study was to provide a set of scientific and objective evaluation criteria for assessing the quality of ankle fracture reduction accurately and reliably by an intelligent combining three-dimensional (3-D) computed tomography (CT) measurement model. Methods From June 2008 to March 2011, all the thin-slice CT images of 100 cases (50 males and 50 females) with normal ankle joint scanned by 16-slice spiral CT were collected. Two-dimensional (2-D) and 3-D images of ankle joints were generated by using multiple planar reconstruction (MPR) and surface shaded display (SSD) respectively. The relevant parameters about bone structures and their relationship were measured and analyzed based on 3-D topological narrow division technique and 3-D measurement techniques combining essential elements of point, line and surface. Results In this study, the mean distance from lateral malleolus tip to talocrural articular surface, the tip of medial malleolus anterior colliculus to talocrural articular surface and lateral malleolus tip to the tip of medial malleolus anterior colliculus were (22.83±1.12) mm, (12.84±1.09) mm, and (61.18±2.03) mm respectively in male group, and (20.16±1.00) mm, (10.30±1.05) mm and (53.00±1.40) mm respectively in female group. The above three parameters were correlated with gender, height and weight (P 〈0.05). However, the mean perpendicular distance from lateral malleolus tip to the plane through the tip of medial malleolus anterior colliculus, the talocrural angle, later clear space, medial clear space, and the superior clear space were (9.93±0.29) mm, (10.01±0.38)°, (1.94±0.16) mm, (2.78±0.19) mm, and (3.14±0.15) mm respectively in 100 cases, were not significance correlated with gender, height and weight (P 〉0.05). Conclusions This study could provide a certain amount of relevant data for the standard of injured ankle anatomical reduction and the second surgery planning after malunion. The methods of measurement are reliable, reproducible, and easy to apply in practice.展开更多
This study examined the dynamic characteristics of upper airway collapse at soft palate level in patients with obstructive sleep apnea/hypopnea syndrome(OSAHS) by using dynamic 3-Dimensional(3-D) CT imaging.A tota...This study examined the dynamic characteristics of upper airway collapse at soft palate level in patients with obstructive sleep apnea/hypopnea syndrome(OSAHS) by using dynamic 3-Dimensional(3-D) CT imaging.A total of 41 male patients who presented with 2 of the following symptoms,i.e.,daytime sleepiness and fatigue,frequent snoring,and apnea with witness,were diagnosed as having OSAHS.They underwent full-night polysomnography and then dynamic 3-D CT imaging of the upper airway during quiet breathing and in Muller's maneuver.The soft palate length(SPL),the minimal cross-sectional area of the retropalatal region(mXSA-RP),and the vertical distance from the hard palate to the upper posterior part of the hyoid(hhL) were compared between the two breathing states.These parameters,together with hard palate length(HPL),were also compared between mild/moderate and severe OSAHS groups.Association of these parameters with the severity of OSAHS [as reflected by apnea hypopnea index(AHI) and the lowest saturation of blood oxygen(LSaO2)] was examined.The results showed that 31 patients had severe OSAHS,and 10 mild/moderate OSAHS.All the patients had airway obstruction at soft palate level.mXSA-RP was significantly decreased and SPL remarkably increased during Muller's maneuver as compared with the quiet breathing state.There were no significant differences in these airway parameters(except the position of the hyoid bone) between severe and mild/moderate OSAHS groups.And no significant correlation between these airway parameters and the severity of OSAHS was found.The position of hyoid was lower in the severe OSAHS group than in the mild/moderate OSAHS group.The patients in group with body mass index(BMI)≥26 had higher collapse ratio of mXSA-RP,greater neck circumference and smaller mXSA-RP in the Muller's maneuver than those in group with BMI26(P0.05 for all).It was concluded that dynamic 3-D CT imaging could dynamically show the upper airway changes at soft palate level in OSAHS patients.All the OSAHS patients had airway obstruction of various degrees at soft palate level.But no correlation was observed between the airway change at soft palate level and the severity of OSAHS.The patients in group with BMI≥26 were more likely to develop airway obstruction at soft palate level than those with BMI26.展开更多
Four cases of proximal femoral focal deficiency (PFFD) in an otherwise healthy infant are described. Antenatal diagnosis was made at 27, 23, 23 and 18 weeks of gestation by routine ultrasound (US) examination. Compute...Four cases of proximal femoral focal deficiency (PFFD) in an otherwise healthy infant are described. Antenatal diagnosis was made at 27, 23, 23 and 18 weeks of gestation by routine ultrasound (US) examination. Computer Tomography (CT) was performed after 30 weeks of gestation and confirmed the images obtained by US. The diagnosis was confirmed after delivery. These cases illustrate the importance of combining US and CT to improve accuracy of prenatal diagnosis of skeletal disorders.展开更多
基金Supported by Multicenter Clinical Trial of h UC-MSCs in the Treatment of Late Chronic Spinal Cord Injury,No.2017YFA0105404Key Discipline Construction Project of Pudong Health Bureau of Shanghai,No.PWZxk2017-08
文摘BACKGROUND Posterior malleolar fractures have been reported to occur in<40%of ankle fractures.AIM To reveal the recurrent patterns and characteristics of posterior malleolar fractures by creating fracture maps of the posterior malleolar fractures through the use of computed tomography mapping.METHODS A consecutive series of posterior malleolar fractures was used to create threedimensional reconstruction images,which were oriented and superimposed to fit an ankle model template by both aligning specific biolandmarks and reducing reconstructed fracture fragments.Fracture lines were found and traced in order to generate an ankle fracture map.RESULTS This study involved 112 patients with a mean age of 49,comprising 32 pronationexternal rotation grade IV fractures and 80 supination-external rotation grade IV fractures according to the Lauge-Hansen classification system.Three-dimensional maps showed that the posterior ankle fracture fragments in the supinationexternal rotation grade IV group were relatively smaller than those in the pronation-external rotation grade IV group after posterior malleolus fracture.In addition,the distribution analyses on posterior malleolus fracture lines indicated that the supination-external rotation grade IV group tended to have higher linear density but more concentrated and orderly distribution fractures compared to the pronation-external rotation grade IV group.CONCLUSION Fracture maps revealed the fracture characteristics and recurrent patterns of posterior malleolar fractures,which might help to improve the understanding of ankle fracture as well as increase opportunities for follow-up research and aid clinical decision-making.
基金Supported by The National Natural Science Foundation of China,No.81800050Natural Science Fund of Yangzhou City,No.YZ2017119Science and Technology Innovation Cultivation Program of Yangzhou University,No.2017CXJ122
文摘BACKGROUND Situs inversus totalis(SIT)is a rare congenital condition that is characterized by a complete mirror image of the typical arrangement of the thoracic and abdominal viscera.Performing thoracoscopic segmentectomy for a patient with lung cancer and SIT is an extremely skilled and challenging surgical procedure.CASE SUMMARY A 41-year old woman with a medical history of dextrocardia since childhood was admitted to our hospital with a mixed ground-glass opacity(mGGO)in her left lung field,discovered by computed tomography during her health checkup.In order to facilitate surgical orientation,three-dimensional computed tomography bronchography and angiography(3D-CTBA)was preoperatively carried out.The result of 3D-CTBA was consistent with the diagnosis of SIT and an mGGO in the posterior segment of the left upper lobe(LS2).Surgery was conducted in accordance with preoperative 3D-CTBA and designed surgical procedure,combined with intraoperative navigation.Final pathological examination revealed in situ adenocarcinoma.The patient’s postoperative condition was uneventful and no complications were observed.CONCLUSION We present the first case of lung cancer in a patient with SIT who successfully underwent thoracoscopic segmentectomy assisted by 3D-CTBA.This is a new technique that covers precise confirmation and dissection of targeted structures and intersegmental demarcation,and can help achieve a meticulous anatomical segmentectomy.
基金supported by the National Natural Science Foundation Project(41501283)Beijing Science and Technology Plan Project(Z161100000916012)+2 种基金the National Key Research and Development Program(2017YFD0600901)Special Fund for Beijing Common Construction Projectthe Fundamental Research Funds for the Central Universities(2015ZCQ-GX-04)
文摘The geometric and spatial characteristics of pore structures determine the permeability and water retention of soils, which have important effects on soil functional diversity and ecological restoration. Until recently, there have not been tools and methods to visually and quantitatively describe the characteristics of soil pores. To solve this problem, this research reconstructs the geometry and spatial distribution of soil pores by the marching cubes method, texture mapping method and the ray casting method widely used in literature. The objectives were to explore an optimal method for three-dimensional visualization of soil pore structure by comparing the robustness of the three methods on soil CT images with single pore structure and porosity ranging from low (2–5%) to high (12–18%), and to evaluate the reconstruction performance of the three methods with different geometric features. The results demonstrate that there are aliases (jagged edges) and deficiency at the boundaries of the model reconstructed by the marching cubes method and pore volumes are smaller than the ground truth, whereas the results of the texture mapping method lack the details of pore structures. For all the soil images, the ray casting method is preferable since it better preserves the pore characteristics of the ground truth. Furthermore, the ray casting method produced the best soil pore model with higher rendering speed and lower memory consumption. Therefore, the ray casting method provides a more advanced method for visualization of pore structures and provides an optional technique for the study of the transport of moisture and the exchange of air in soil.
文摘To correct a lower limb deformity, orthopedic surgeons must have an exact understanding of the deformity. In general, preoperative planning is carried out using anterior-posterior (AP) and lateral radiographs. However, for severe cases with a combination of angular and rotational deformities of the lower limb, obtaining true AP and lateral radiographs is difficult and accurate calculation of the rotational deformity from radiographs is impossible. In this report, we propose to focus on preoperative assessment using three-dimensional (3D) reconstruction images of computed tomography (CT) scans for severe lower limb deformity in a patient with bilateral fibular hemimelia type II according to the Achterman- Kalamchi classification. She underwent bifocal deformity corrections of the bilateral tibiae using Taylor spatial frames in combination with the Ilizarov external fixator. Complete bony union was achieved, without angular deformity or limb length discrepancy.
文摘AIM To evaluate usefulness of single photon emission computed tomography(SPECT) with three-dimensional stereotactic surface projection(3D-SSP) in distinguishing between Alzheimer's disease(AD) and depression.METHODS We studied 43 patients who presented with both depressive symptoms and memory disturbance. Each subject was evaluated using the following:(1) the Minimal Mental State Examination;(2) the Hamilton Rating Scale for Depression;(3) Clinical Global Impression-Severity scale(CGI-S); and(4) SPECT imaging with 3D-SSP.RESULTS The MMSE scores correlated significantly with the maximum Z-scores of AD-associated regions. CGI-S scores correlated significantly with the maximum Z-scores of depression-associated regions. Factor analysis identified three significant factors. Of these, Factor 1 could be interpreted as favouring a tendency for AD, Factor 2 as favouring a tendency for pseudo-dementia, and Factor 3 as favouring a depressive tendency.CONCLUSION We investigated whether these patients could be categorized as types: Type A(true AD), Type B(pseudodementia), Type C(occult AD), and Type D(true depression). The factor scores in factor analysis supported the validity of this classification. Our results suggest that SPECT with 3D-SSP is highly useful for distinguishing between depression and depressed mood in the early stage of AD.
文摘AIM: To evaluate the usefulness of three-dimensional computed tomography (3DCT) in laparoscopic surgery for colorectal carcinoma.METHODS: Seventy-two patients with colorectal cancer who underwent curative operation at our hospital were enrolled in this study. They were classified into two groups by operative procedures. Sixteen patients underwent laparoscopic surgery, laparoscopic group (LG),while 56 patients underwent conventional open surgery,open group (OG). At our institution, contrast-enhanced CT is routinely performed as part of intra-abdominal screening and the 3D images of the major regional vessels are described. We have previously described about the preoperative visualization of the inferior mesenteric artery (IMA) by 3DCT. This time we newly acquired 3D images of the superior mesenteric artery (SMA)/superior mesenteric vein (SMV), ileocecal artery(ICA), middle colic artery (MCA), and inferior mesenteric vein (IMV). We have compared our two study groups with regard to five items, including clinical anastomotic leakage. We have discussed here the role of 3DCT in laparoscopic surgery for colorectal carcinoma.RESULTS: The mean length of the incision inLG was4.625±0.89 cm, which was significantly shorter than that in OG (P<0.001). The association between ICA and SMV and SMA was described in the right-sided colectomy. The preoperative imaging of IMA and IMV was created in the rectosigmoidectomy. There was no significant difference in anastomotic leakage between the two groups, but no patients in LG experienced anastomotic leakage.CONCLUSION: Most of the patients are satisfied with the shorter incisional length following laparoscopic surgery. Preoperative visualization of the major regional vessels may be helpful for the secure treatment of the anastomosis in laparoscopic surgery for colorectal carcinoma.
基金financially supported by the National Science and Technology Major Project "Aero Engine and Gas Turbine"(No.2017-Ⅶ-0008-0102)National Nature Science Foundation of China (No.51701112 and No.51690162)+1 种基金Shanghai Rising-Star Program (No.20QA1403800 and No.21QC1401500)Shanghai Science and Technology Committee (No.21511103600)
文摘Aero-engine hollow turbine blades are work under prolonged high temperature,requiring high dimensional accuracy.Blade profile and wall thickness are important parameters to ensure the comprehensive performance of blades,which need to be measured accurately during manufacturing process.In this study,a high accuracy industrial computed tomography(ICT)measuring method was developed based on standard cylindrical pin and ring workpieces of different sizes.Combining ICT with cubic spline interpolation,a sub-pixel accuracy was achieved in measuring the dimension of component.Compared with the traditional and whole-pixel level image measurement method,the cubic spline interpolation algorithm has the advantages of high accuracy in image edge detection and thus high accuracy of dimensional measurement.Further,the technique was employed to measure the profile and wall thickness of a typical aerospace engine turbine blade,and an accuracy higher than 0.015 mm was obtained.
文摘Crohn's disease,a transmural inflammatory bowel disease,remains a difficult entity to diagnose clinically.Over the last decade,multidetector computed tomography(CT) has become the method of choice for noninvasive evaluation of the small bowel,and has proved to be of significant value in the diagnosis of Crohn's disease.Advancements in CT enterography protocol design,three dimensional(3-D) post-processing software,and CT scanner technology have allowed increasing accuracy in diagnosis,and the acquisition of studies at a much lower radiation dose.The cases in this review will illustrate that the use of 3-D technique,proper enterography protocol design,and a detailed understanding of the different manifestations of Crohn's disease are all critical in properly diagnosing the full range of possible complications in Crohn's patients.In particular,CT enterography has proven to be effective in identifying involvement of the small and large bowel(including active inflammation,stigmata of chronic inflammation,and Crohn's-related bowel neoplasia) by Crohn's disease,as well as the extra-enteric manifestations of the disease,including fistulae,sinus tracts,abscesses,and urologic/hepatobiliary/osseous complications.Moreover,the proper use of 3-D technique(including volume rendering and maximum intensity projection) as a routine component of enterography interpretation can play a vital role in improving diagnostic accuracy.
文摘Background: 4D-CT has been used to localize the parathyroid adenomas and hyperplasia since 2006 as a second line study after TC-99 m MIBI and ultrasonography. However, multiple studies have shown that 4D-CT is a robust imaging method with high diagnostic accuracy, becoming increasingly popular among surgeons and radiologists. Purpose: To assess the diagnostic performance of 4D-CT scans to identify the pathologic gland(s), using pathology and intraoperative findings as gold standards. Methods: We analyzed patients with primary and secondary hyperparathyroidism who had intraoperative reports, pathology, parathyroid hormone levels, and preoperative 4D-CT. Histology, surgical findings, and decreased parathyroid hormone levels were used as gold standards. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy and 95% confidence interval were calculated. Fleiss’ kappa was used to assess the inter-observer agreement. Results: Sixty-seven patients were included. Sixty-two patients had a single adenoma, and five patients had a multiple gland disease (adenomas or hyperplasia). A total of 72 glands were proven to have parathyroid adenomas or hyperplasia. The sensitivity, specificity, PPV, NPV and accuracy are 85%, 97%, 96%, 87% and 91% for lateralization and 76%, 96%, 85%, 92% and 90% for quadrant localization, respectively in single-gland disease. The sensitivity, specificity, PPV, NPV and accuracy are 88%, 100%, 100%, 50% and 90% for lateralization and 71%, 100%, 100%, 60% and 80% for quadrant localization respectively in multiple-gland disease. Fleiss’ kappa value is 5.6 (moderate inter-observer agreement). Conclusion: 4D-CT is a robust method in the localization of hyperfunctioning parathyroid glands with high accuracy and at least moderate inter-observer agreement.
基金Guangzhou Municipal Medicine &Health ProgramGrant number:2006-YB-177+1 种基金Guangdong Province Medicine Scientific Research ProgramGrant number:A2007290
文摘Objective:To investigate the feasibility of a 4D-CT reconstruction method based on the similarity principle of spatial adjacent images and mutual information measure. Methods:A motor driven sinusoidal motion platform made in house was used to create one-dimensional periodical motion that was along the longitudinal axis of the CT couch. The amplitude of sinusoidal motion was set to an amplitude of ±1 cm. The period of the motion was adjustable and set to 3.5 s. Phantom objects of two eggs were placed in a Styrofoam block, which in turn were placed on the motion platform. These objects were used to simulate volumes of interest undergoing ideal periodic motion. CT data of static phantom were acquired using a multi-slice general electric (GE) LightSpeed 16-slice CT scanner in an axial mode. And the CT data of periodical motion phantom were acquired in an axial and cine-mode scan. A software program was developed by using VC++ and VTK software tools to resort the CT data and reconstruct the 4D-CT. Then all of the CT data with same phase were sorted by the program into the same series based on the similarity principle of spatial adjacent images and mutual information measure among them, and 3D reconstruction of different phase CT data were completed by using the software. Results:All of the CT data were sorted accurately into different series based on the similarity principle of spatial adjacent images and mutual information measures among them. Compared with the unsorted CT data, the motion artifacts in the 3D reconstruction of sorted CT data were reduced significantly, and all of the sorted CT series result in a 4D-CT that reflected the characteristic of the periodical motion phantom. Conclusion:Time-resolved 4D-CT reconstruction can be implemented with any general multi-slice CT scanners based on the similarity principle of spatial adjacent images and mutual information measure.The process of the 4D-CT data acquisition and reconstruction were not restricted to the hardware or software of the CT scanner and has the feasibility ,which extensive applicability.
基金supported by a Grant-in-Aid for Scientific Research (22659366) from the Japan Society for the Promotion of Science
文摘To evaluate the feasibility and accuracy of a three-dimensional augmented reality system incorporating integral videography for imaging oral and maxillofacial regions, based on preoperative computed tomography data. Three-dimensional surface models of the jawbones, based on the computed tomography data, were used to create the integral videography images of a subject's maxillofacial area. The three-dimensional augmented reality system (integral videography display, computed tomography, a position tracker and a computer) was used to generate a three-dimensional overlay that was projected on the surgical site via a half-silvered mirror. Thereafter, a feasibility study was performed on a volunteer. The accuracy of this system was verified on a solid model while simulating bone resection. Positional registration was attained by identifying and tracking the patient/surgical instrument's position. Thus, integral videography images of jawbones, teeth and the surgical tool were superimposed in the correct position. Stereoscopic images viewed from various angles were accurately displayed. Change in the viewing angle did not negatively affect the surgeon's ability to simultaneously observe the three-dimensional images and the patient, without special glasses. The difference in three-dimensional position of each measuring point on the solid model and augmented reality navigation was almost negligible (〈1 mm); this indicates that the system was highly accurate. This augmented reality system was highly accurate and effective for surgical navigation and for overlaying a three-dimensional computed tomography image on a patient's surgical area, enabling the surgeon to understand the positional relationship between the preoperative image and the actual surgical site, with the naked eye.
基金Acknowledgements The authors gratefully acknowledge the financial support from the State Key Research Development Program of China (Grant No. 2016YFC0600705), the National Natural Science Foundation of China (Grant Nos. 51674251, 51727807, 51374213), the National Natural Science Foundation for Distinguished Young Scholars of China (Grant No. 51125017), the Fund for Creative Research and Development Group Program of Jiangsu Province (Grant No. 2014-27), and the Priority Academic Program Development of Jiangsu Higher Education Institutions (Grant No. PAPD2014), and an open project sponsored by the State Key Labo- ratory for Geomechanics and Deep Underground Engineering (Grant SKLGDUE K1318) for their financial support.
基金Grant sponsor:Guangzhou Municipal Medicin &Health ProgramGrant number:2006-YB-177
文摘Objective:To investigate the influences of motion artifacts on three-dimensional (3D) reconstruction volume and conformal radiotherapy planning. Methods:A phantom which can mimic the clip motion of lung tumor along the cranial-caudal direction is constructed by step motor, small ball of polyethylene and potato. Ten different scan protocols were set and CT data of the phantom were acquired by using a commercial GE LightSpeed16 CT scanner. The 3D reconstruction of the CT data was implemented by adopting volume-rendering technology of GE AdvantageSim 6.0 system. The reconstructed volumes of each target in different scan protocols were measured through 3D measuring tools. Thus, relative deviations of the reconstruction volumes between moving targets and static ones were determined. The three-dimensional conformal radiation therapy (3D-CRT) plans and conformal fields were created and compared for a static/moving target with the WiMRT treatment planning system (TPS). Results:For a static target, there was no obvious difference among the 3D reconstruction volumes when the CT data were acquired with different pitches and slices. The appearance of 3D reconstruction volume and 3D conformal field of a moving target was quite different from that of static one. The maximum relative deviation is nearly 90% for a moving target scanned with different scan protocols. The relative deviations are variable among the different targets, about from -39.8% to 89.5% for a smaller target and from -18.4% to 20.5% for a larger one. Conclusion:The motion artifacts have great effects on 3D-CRT planning and reconstruction volume, which will greatly induce distorted conformal radiation fields and false DVHs for a moving target.
文摘Multi-detector row computed tomography urography (MDCTU) becomes the imaging modality of choice for evaluation of the kidneys and urinary tract. The aim of this study was to discuss and illustrate the role of MDCTU, on a 32-row CT scanner in the evaluation a variety of entities that were frequently associated with microscopic hematuria in adults. This prospective cohort study was performed in the period of August 2013 to October 2014. Fifty positive participants to microscopic hematuria were examined at the radiology department of Alnilin Diagnostic Medical Center and Antalya Medical Center. Computed tomography urography (CTU) scanning was performed using two powerful performances, high speed multi-detector row on 32-row CT scanners (Siemens Healthcare Global, Somatom Emotion Duo Eco). Statistical analysis was done through the standard Statistical Package for the Social Sciences (SPSS Inc., Chicago, IL, USA) version 15 for windows. MDCTU established the correct cause of microscopic hematuria in (44;88%) of participants. In (6;12%) of participants, no cause of hematuria was identified based on the standard of references. The causes of hematuria in (41;82%) participants were diseases in the upper urinary tract, while urinary bladder neoplasms (2;4%) and diverticulum (1;2%) were the causes of hematuria (3;6%) in the lower urinary tract. Thirty two-row MDCTU scanner demonstrated satisfactory results in the investigation of microscopic hematuria, being able to demonstrate a wide spectrum of diseases affecting the urinary tract is the main advantage of the technique.
基金the National Natural Science Foundation of China
文摘As precise positioning of ankle radiography is not possible, quantitative measurement of all syndesmotic parameters on repeated ankle X-ray films may be of little value. The purpose of this study was to provide a set of scientific and objective evaluation criteria for assessing the quality of ankle fracture reduction accurately and reliably by an intelligent combining three-dimensional (3-D) computed tomography (CT) measurement model. Methods From June 2008 to March 2011, all the thin-slice CT images of 100 cases (50 males and 50 females) with normal ankle joint scanned by 16-slice spiral CT were collected. Two-dimensional (2-D) and 3-D images of ankle joints were generated by using multiple planar reconstruction (MPR) and surface shaded display (SSD) respectively. The relevant parameters about bone structures and their relationship were measured and analyzed based on 3-D topological narrow division technique and 3-D measurement techniques combining essential elements of point, line and surface. Results In this study, the mean distance from lateral malleolus tip to talocrural articular surface, the tip of medial malleolus anterior colliculus to talocrural articular surface and lateral malleolus tip to the tip of medial malleolus anterior colliculus were (22.83±1.12) mm, (12.84±1.09) mm, and (61.18±2.03) mm respectively in male group, and (20.16±1.00) mm, (10.30±1.05) mm and (53.00±1.40) mm respectively in female group. The above three parameters were correlated with gender, height and weight (P 〈0.05). However, the mean perpendicular distance from lateral malleolus tip to the plane through the tip of medial malleolus anterior colliculus, the talocrural angle, later clear space, medial clear space, and the superior clear space were (9.93±0.29) mm, (10.01±0.38)°, (1.94±0.16) mm, (2.78±0.19) mm, and (3.14±0.15) mm respectively in 100 cases, were not significance correlated with gender, height and weight (P 〉0.05). Conclusions This study could provide a certain amount of relevant data for the standard of injured ankle anatomical reduction and the second surgery planning after malunion. The methods of measurement are reliable, reproducible, and easy to apply in practice.
文摘This study examined the dynamic characteristics of upper airway collapse at soft palate level in patients with obstructive sleep apnea/hypopnea syndrome(OSAHS) by using dynamic 3-Dimensional(3-D) CT imaging.A total of 41 male patients who presented with 2 of the following symptoms,i.e.,daytime sleepiness and fatigue,frequent snoring,and apnea with witness,were diagnosed as having OSAHS.They underwent full-night polysomnography and then dynamic 3-D CT imaging of the upper airway during quiet breathing and in Muller's maneuver.The soft palate length(SPL),the minimal cross-sectional area of the retropalatal region(mXSA-RP),and the vertical distance from the hard palate to the upper posterior part of the hyoid(hhL) were compared between the two breathing states.These parameters,together with hard palate length(HPL),were also compared between mild/moderate and severe OSAHS groups.Association of these parameters with the severity of OSAHS [as reflected by apnea hypopnea index(AHI) and the lowest saturation of blood oxygen(LSaO2)] was examined.The results showed that 31 patients had severe OSAHS,and 10 mild/moderate OSAHS.All the patients had airway obstruction at soft palate level.mXSA-RP was significantly decreased and SPL remarkably increased during Muller's maneuver as compared with the quiet breathing state.There were no significant differences in these airway parameters(except the position of the hyoid bone) between severe and mild/moderate OSAHS groups.And no significant correlation between these airway parameters and the severity of OSAHS was found.The position of hyoid was lower in the severe OSAHS group than in the mild/moderate OSAHS group.The patients in group with body mass index(BMI)≥26 had higher collapse ratio of mXSA-RP,greater neck circumference and smaller mXSA-RP in the Muller's maneuver than those in group with BMI26(P0.05 for all).It was concluded that dynamic 3-D CT imaging could dynamically show the upper airway changes at soft palate level in OSAHS patients.All the OSAHS patients had airway obstruction of various degrees at soft palate level.But no correlation was observed between the airway change at soft palate level and the severity of OSAHS.The patients in group with BMI≥26 were more likely to develop airway obstruction at soft palate level than those with BMI26.
文摘Four cases of proximal femoral focal deficiency (PFFD) in an otherwise healthy infant are described. Antenatal diagnosis was made at 27, 23, 23 and 18 weeks of gestation by routine ultrasound (US) examination. Computer Tomography (CT) was performed after 30 weeks of gestation and confirmed the images obtained by US. The diagnosis was confirmed after delivery. These cases illustrate the importance of combining US and CT to improve accuracy of prenatal diagnosis of skeletal disorders.