AIM To determine the sensitivity and specificity of high resolution computed tomography(HRCT) in the diagnosis of otosclerosis.METHODS A systematic literature review was undertaken to include Level I-III studies(Oxfor...AIM To determine the sensitivity and specificity of high resolution computed tomography(HRCT) in the diagnosis of otosclerosis.METHODS A systematic literature review was undertaken to include Level I-III studies(Oxford Centre for Evidenced based Medicine) that utilised HRCT to detect histology confirmed otosclerosis.Quantitative synthesis was then performed.RESULTS Based on available level III literature,HRCT has a relatively low sensitivity of 58%(95%CI: 49.4-66.9),a high specificity,95%(95%CI: 89.9-98.0) and a positive predictive value of 92%(95%CI: 84.1-95.8).HRCT is better at diagnosing the more prevalent fenestral form of otosclerosis but remains vulnerable to inframillimetre,retrofenestral and dense sclerotic lesions,despite the advent of more advanced CT scanners with improved collimation.CONCLUSION Whilst the diagnosis of otosclerosis remains largely clinical,HRCT remains the gold standard imaging of choice for the middle ear and serves as a useful adjunct to the clinician,helping to delineate extent of disease and exclude other causes.展开更多
Mineral dissemination and pore space distribution in ore particles are important features that influence heap leaching performance. To quantify the mineral dissemination and pore space distribution of an ore particle,...Mineral dissemination and pore space distribution in ore particles are important features that influence heap leaching performance. To quantify the mineral dissemination and pore space distribution of an ore particle, a cylindrical copper oxide ore sample (I center dot 4.6 mm x 5.6 mm) was scanned using high-resolution X-ray computed tomography (HRXCT), a nondestructive imaging technology, at a spatial resolution of 4.85 mu m. Combined with three-dimensional (3D) image analysis techniques, the main mineral phases and pore space were segmented and the volume fraction of each phase was calculated. In addition, the mass fraction of each mineral phase was estimated and the result was validated with that obtained using traditional techniques. Furthermore, the pore phase features, including the pore size distribution, pore surface area, pore fractal dimension, pore centerline, and the pore connectivity, were investigated quantitatively. The pore space analysis results indicate that the pore size distribution closely fits a log-normal distribution and that the pore space morphology is complicated, with a large surface area and low connectivity. This study demonstrates that the combination of HRXCT and 3D image analysis is an effective tool for acquiring 3D mineralogical and pore structural data.展开更多
Objective. To study the difference of interstitial lung diseases (ILDs) in high-resolution computerized tomography and pulmonary function test among different connective tissue diseases (CTDs). Methods. 209 patients w...Objective. To study the difference of interstitial lung diseases (ILDs) in high-resolution computerized tomography and pulmonary function test among different connective tissue diseases (CTDs). Methods. 209 patients with different CTDs were recruited and underwent lung HRCT and PFT. Eerythrocyte sedimentation rate (ESR), C-reactive protein (CRP), serum ferritin (SF), anti-SSA, and so on were tested. Based on HRCT, a patient was classified into ILD group (CTD+ILD) or non-ILD group (CTD-ILD). HRCT, PFT, and laboratory markers were compared according to CTDs and CTD-associated ILDs. Results. The incidences of ILD were 79.6%, 82.0%, 89.7%, and 97.1% respectively for Rheumatoid arthritis (RA), primary Sjogren’s symptom (pSS), dermatomyositis/polymyositis (DM/PM), and systemic sclerosis (SSc) groups. RA and pSS patients exhibited more nodules, patching, ground-glass opacity, and cord shadow foci in HRCT, DM/PM and SSc patients exhibited more reticular opacity and honeycombing foci. RA and pSS patients exhibited more obstructive ventilatory disorder, small airway dysfunction and emphysema in PFT, and DM/PM and SSc patients exhibited more restrictive ventilatory disorder, mixed ventilatory disorder. ESR, CRP and SF were significantly higher in total CTD+ILD group than in total CTD-ILD group (P = 0.047, 0.006, 0.004, respectively), and higher in different CTD+ ILD groups than in comparable CTD-ILD groups (P = 0.049, 0.048, and 0.023, pSS+ILD, SSc+ILD and RA+ILD compared to pSS-ILD, SSc-ILD and RA-ILD, respectively for ESR, CRP, SF). The positive rate of anti-SSA was significantly higher in DM/PM+ILD group than in DM/PM-ILD group (P = 0.025). Conclusions. The manifestations and incidences of ILDs differ among different CTDs in HRCT and PFT, and inflammation and anti-SSA are positively correlated with ILDs in different CTDs, which provide important evidences for judging disease condition and prognosis.展开更多
COVID-19 which is caused by its new type called SARS-CoV-2 is a viral disease predominantly involving the lungs. <b>Objective:</b> To investigate HRCT features of pulmonary disease in COVID-19 in Lahore, P...COVID-19 which is caused by its new type called SARS-CoV-2 is a viral disease predominantly involving the lungs. <b>Objective:</b> To investigate HRCT features of pulmonary disease in COVID-19 in Lahore, Pakistan. <b>Methods:</b> This is a prospective study that involved 127 COVID-19 positive patients (age 18 - 80 years, both genders) through non-probability sampling was conducted at the Radiology Department, Sir Ganga Ram Hospital, Lahore, in 2021. All patients with RT-PCR positive underwent HRCT chest. All findings in HRCT chest were assessed. Confirmed patients had positive HRCT. Excluded situations are low quality of images irrespective of its reason, HRCT indications other than COVID-19 pneumonia, and patients who do not want to participate in the study <b>Results:</b> Considering the exclusion and inclusion criteria, totally 127 COVID-19 confirmed patients ranging age from 18 to 80 years with a mean age of 52 ± 18 years, took part in this study. The most important and common HRCT finding was the multilobar ground-glass pattern which was present in 95% of patients. Other findings including, crazy paving pattern, consolidation, air bronchogram, and bronchiectasis were present in 8.7%, 82%, 63%, and 37% of patients respectively. Pleural effusion seen in 21% patients. 16% of patients had mediastinal lymphadenopathy. <b>Conclusion:</b> In our study, the ground-glass pattern was found to be the most common and important HRCT finding in patients confirmed with COVID-19 pneumonia. This important HRCT pattern is mostly found to be in posterobasal and peripheral subpleural locations. Other than ground-glass pattern, bronchiectasis, and consolidation having the air bronchogram were also reported commonly.展开更多
The main challenge in bone ultrasound imaging is the large acoustic impedance contrast and sound velocity differences between the bone and surrounding soft tissue. It is difficult for conventional pulse-echo modalitie...The main challenge in bone ultrasound imaging is the large acoustic impedance contrast and sound velocity differences between the bone and surrounding soft tissue. It is difficult for conventional pulse-echo modalities to give accurate ultrasound images for irregular bone boundaries and microstructures using uniform sound velocity assumption rather than getting a prior knowledge of sound speed. To overcome these limitations, this paper proposed a frequency-domain fullwaveform inversion(FDFWI) algorithm for bone quantitative imaging utilizing ultrasonic computed tomography(USCT).The forward model was calculated in the frequency domain by solving the full-wave equation. The inverse problem was solved iteratively from low to high discrete frequency components via minimizing a cost function between the modeled and measured data. A quasi-Newton method called the limited-memory Broyden–Fletcher–Goldfarb–Shanno algorithm(L-BFGS) was utilized in the optimization process. Then, bone images were obtained based on the estimation of the velocity and density. The performance of the proposed method was verified by numerical examples, from tubular bone phantom to single distal fibula model, and finally with a distal tibia-fibula pair model. Compared with the high-resolution peripheral quantitative computed tomography(HR-p QCT), the proposed FDFWI can also clearly and accurately presented the wavelength scaled pores and trabeculae in bone images. The results proved that the FDFWI is capable of reconstructing high-resolution ultrasound bone images with sub-millimeter resolution. The parametric bone images may have the potential for the diagnosis of bone disease.展开更多
Background:?High resolution chest computed tomography (HRCT) is an established imaging modality that accurately assesses disease processes that are non-specific on conventional chest radiography. Chest Computed Tomogr...Background:?High resolution chest computed tomography (HRCT) is an established imaging modality that accurately assesses disease processes that are non-specific on conventional chest radiography. Chest Computed Tomography (CT) has proven invaluable in the evaluation of various diseases of the chest providing precise diagnosis that have great impact on the course of management. In this study, our aim is to evaluate the spectrum of radiological findings in all patients that had chest CTs at a tertiary health Institution in a developing Country. Method: This is a 6-year retrospective study of all patients that had Chest CT from 2009 till 2015. All patient data were retrieved and their Chest CT images reviewed and radiological findings and diagnosis documented. Results: Age range of patients was 1 - 84 years with a mean of 52.36 ± 22.9 years. Ten patients were children (12%). There were more males 53 (63.1%) than females 31 (36.9%) in the study. Referral for imaging was predominantly from internal medicine 33 (47.1%) and Surgery 27 (38.6%) departments. Most of the patients, 53 (63.1%) did not have previous chest radiographs. Consolidative changes were the most common parenchymal finding (77.4%). Few mediastinal masses were found in the study population. CT angiography constituted only 10.7% of all chest CTs done in adults. Conclusion: Few chest CT evaluations are performed compared to CTs of other parts of the body done in the same period. Chest CT is generally under-utilized even in a tertiary institution. There is a need to educate chest physicians on the role and advantages of CT use for the management of their patients.展开更多
Objective: High-dose chemotherapy(HDC) followed by autologous hematopoietic stem cell transplantation(auto-HSCT) plays an important role in improving outcomes of diffuse large B cell lymphoma(DLBCL) patients.18 F-fluo...Objective: High-dose chemotherapy(HDC) followed by autologous hematopoietic stem cell transplantation(auto-HSCT) plays an important role in improving outcomes of diffuse large B cell lymphoma(DLBCL) patients.18 F-fluorodeoxyglucose(18 F-FDG) positron emission tomography(PET)/computed tomography(CT) has been widely accepted in response assessment and prediction of prognosis in DLBCL. Here, we report the value of 18 FFDG PET/CT pre-and post-HSCT in predicting outcomes of patients with DLBCL.Methods: DLBCL patients who had PET/CT scan before and after HSCT were included. PET results were interpreted based upon Deauville criteria. The prognostic value of 18 F-FDG PET/CT in auto-HSCT was evaluated.Results: Eighty-four patients were enrolled. In univariate analysis, pre-and post-HSCT PET findings were correlated with 3-year progression-free survival(PFS) [hazard ratio(HR)=4.391, P=0.001; HR=7.607, P<0.001] and overall survival(OS)(HR=4.792, P=0.008; HR=26.138, P<0.001). Patients receiving upfront auto-HSCT after firstline treatment had better outcomes than relapsed/refractory DLBCL patients(3-year PFS, P<0.001; 3-year OS,P<0.001). In the relapsed/refractory patients, pre-and post-HSCT PET findings were also associated with 3-year PFS(P=0.003 vs. P<0.001) and OS(P=0.027 vs. P<0.001). A significant correlation was observed between clinical response to chemotherapy before auto-HSCT and outcomes of patients in the entire cohort(3-year PFS, P<0.001;3-year OS, P<0.001) and in the subgroup of 21 patients with positive pre-HSCT PET(3-year PFS, P=0.084; 3-year OS, P=0.240). A significant association between survival and post-HSCT PET findings was observed in multivariate analysis(HR=5.168, P<0.001).Conclusions: PET results before and after HSCT are useful prognostic factors for DLBCL patients receiving HSCT. Patients who responded to chemotherapy, even those with positive pre-HSCT PET, are appropriate candidates for auto-HSCT.展开更多
BACKGROUND Pulmonary alveolar microlithiasis(PAM)is a rare idiopathic lung disease characterized by the accumulation of innumerable microliths.Currently,effective therapeutics for PAM are not available,and the only tr...BACKGROUND Pulmonary alveolar microlithiasis(PAM)is a rare idiopathic lung disease characterized by the accumulation of innumerable microliths.Currently,effective therapeutics for PAM are not available,and the only treatment for end-stage lung disease is lung transplantation(LuTx).Further,there are few reports that focus on LuTx for the treatment of PAM,and the follow-up reports of postoperative imaging are even rarer.CASE SUMMARY A 52-year-old man presented to Shanghai Pulmonary Hospital in 2017 after experiencing shortness of breath and exacerbation.The patient was diagnosed with PAM and referred for single-LuTx(SLuTx)on March 14,2018.Preoperative imaging results from a chest X-ray demonstrated bilateral,diffuse,symmetrical,sandstorm-like radiopaque micronodules,and pneumothorax and a computed tomography scan revealed minute,calcified military nodules in both lungs.We performed a left SLuTx,and intraoperative pathology was consistent with PAM.One week after surgery,a chest X-ray revealed slight exudation of the left lung,and one month later,the left transplanted lung exhibited good dilation,mild pulmonary perfusion injury with local infection,and left pleural effusion.Fiberoptic bronchoscopy revealed left hyperplastic granulation at the left bronchial anastomosis.Multiple sputum cultures suggested the presence of Klebsiella pneumoniae and Acinetobacter baumannii.The last follow-up was conducted in April 2019;the patient recovered well.CONCLUSION This case presents the imaging findings of a patient with PAM before and after LuTx and confirms the effectiveness of LuTx for the treatment of this disease.展开更多
Modern computer techniques have been in use for several years to generate three-dimensional visualizations of human anatomy. Very good 3-D computer models of the human body are now available and used routinely in anat...Modern computer techniques have been in use for several years to generate three-dimensional visualizations of human anatomy. Very good 3-D computer models of the human body are now available and used routinely in anatomy instruction. These techniques are subsumed under the heading “virtual anatomy” to distinguish them from the conventional study of anatomy entailing cadavers and anatomy textbooks. Moreover, other imaging procedures (X-ray, angiography, CT and MR) are also used in virtual anatomy instruction. A recently introduced three-dimensional post-processing technique named Cinematic Rendering now makes it possible to use the output of routine CT and MR examinations as the basis for highly photo-realistic 3-D depictions of human anatomy. We have installed Cinematic Rendering (enabled for stereoscopy) in a high-definition 8K 3-D projection space that accommodates an audience of 150. The space’s projection surface measures 16 × 9 meters;images can be projected on both the front wall and the floor. A game controller can be used to operate Cinematic Rendering software so that it can generate interactive real-time depictions of human anatomy on the basis of CT and MR data sets. This prototype installation was implemented without technical problems;in day-to-day, real-world use over a period of 22 months, there were no impairments of service due to software crashes or other technical problems. We are already employing this installation routinely for educational offerings open to the public, courses for students in the health professions, and (continuing) professional education units for medical interns, residents and specialists—in, so to speak, the dissecting theater of the future.展开更多
Background The correct diagnosis of etiology of fungal infection after bone marrow transplantation is very important to the choice of antifungal drugs and a premise for improvement of therapeutic efficacy. This study ...Background The correct diagnosis of etiology of fungal infection after bone marrow transplantation is very important to the choice of antifungal drugs and a premise for improvement of therapeutic efficacy. This study aimed to compare high-resolution computed tomography （HRCT） findings of the pulmonary fungal infections to determine whether the etiology of various fungal infections could be diagnosed with HRCT. Methods Eighty-five cases were enrolled. According to the pathogens responsible for fungal infections, the patients were classified into three groups including invasive aspergillosis （n=52）, candidiasis （n=19） and cryptococcosis （n=14） groups. All the patients underwent HRCT scans. Two independent radiologists retrospectively analyzed the HRCT scans regarding CT patterns and distribution of lung abnormality. Results Most fungal infections in the three groups occurred in the neutropenic phase. There was no significant difference in the constituent ratio of fungal infections at different phases after bone marrow transplantation among the three groups. Agreement between the two observers for all the CT characteristics of fungal infections was excellent （k 〉0.75）. There was a significant difference in occurrence ratio of mass among the three groups （P=-0.02）. Occurrence ratio of mass （43.3%, 13/30） in the group with invasive aspergillosis was higher than in each of other two groups （20.0%, 2/10; 14.3%, 1/7）. There was no significant difference in other CT characteristics of nodules or masses; including number, margin, halo sign, cavitation and air-crescent sign. There was no significant difference in number, margin, air bronchogram and distribution of air-space consolidation. Conclusions The HRCT appearance of various pulmonary fungal infections has a great deal of overlap and is nonspecific. Mass is more common in invasive aspergillosis, which is helpful to the diagnosis of invasive aspergillosis after bone marrow transplantation.展开更多
目的探讨高分辨率CT评估免疫治疗相关性肺炎患者诊疗效果及预后。方法2021年5月至2023年5月于肇庆市第一人民医院进行免疫治疗的恶性肿瘤患者1205例,其中32例治疗后并发免疫相关性肺炎,将所有患者的临床资料进行回顾性分析,对所有患者...目的探讨高分辨率CT评估免疫治疗相关性肺炎患者诊疗效果及预后。方法2021年5月至2023年5月于肇庆市第一人民医院进行免疫治疗的恶性肿瘤患者1205例,其中32例治疗后并发免疫相关性肺炎,将所有患者的临床资料进行回顾性分析,对所有患者进行高分辨率计算机断层扫描(CT),分析患者免疫检查点抑制剂治疗情况,免疫相关性肺炎患者临床症状及影像学表现,免疫相关性肺炎出现的时间、诊疗效果及预后。结果14例非小细胞肺癌患者及6例肺部低分化肉瘤样癌均采用纳武力尤单抗注射液静脉滴注治疗,用药剂量为3 mg/kg,治疗频次为每半个月1次;12例非小细胞肺癌患者采用信迪利单抗静脉滴注治疗,剂量为200 mg/次,频次为每21 d 1次。32例免疫相关性肺炎患者的临床分级情况为:2级3例,3级20例,4级9例。12例为对称分布,而20例为非对称分布。患者分型情况如下:20例为磨玻璃型,6例为实变型,6例为网格型。其中有23例伴有胸膜变厚,23例纵隔淋巴结受累,12例伴有支气管扩张,9例伴有小叶间隔变厚,9例伴有多发小叶中心结节,3例伴有胸腔积液。出现免疫相关性肺炎后,32例患者均停止PD-1抑制剂治疗,而应用糖皮质激素连续治疗1~6周,13例出院。结论采用高分辨率CT可以对免疫性肺炎进行诊断,并且有助于对患者进行准确分级、分型,对于已经明确诊断的免疫相关性肺炎患者,应立即停止PD-1抑制剂治疗,之后采用糖皮质激素对患者进行治疗,必要时还可联合抗生素治疗。展开更多
文摘AIM To determine the sensitivity and specificity of high resolution computed tomography(HRCT) in the diagnosis of otosclerosis.METHODS A systematic literature review was undertaken to include Level I-III studies(Oxford Centre for Evidenced based Medicine) that utilised HRCT to detect histology confirmed otosclerosis.Quantitative synthesis was then performed.RESULTS Based on available level III literature,HRCT has a relatively low sensitivity of 58%(95%CI: 49.4-66.9),a high specificity,95%(95%CI: 89.9-98.0) and a positive predictive value of 92%(95%CI: 84.1-95.8).HRCT is better at diagnosing the more prevalent fenestral form of otosclerosis but remains vulnerable to inframillimetre,retrofenestral and dense sclerotic lesions,despite the advent of more advanced CT scanners with improved collimation.CONCLUSION Whilst the diagnosis of otosclerosis remains largely clinical,HRCT remains the gold standard imaging of choice for the middle ear and serves as a useful adjunct to the clinician,helping to delineate extent of disease and exclude other causes.
基金financially supported by the National Natural Science Foundation of China(No.51304076)the Natural Science Foundation of Hunan Province,China(No.14JJ4064)
文摘Mineral dissemination and pore space distribution in ore particles are important features that influence heap leaching performance. To quantify the mineral dissemination and pore space distribution of an ore particle, a cylindrical copper oxide ore sample (I center dot 4.6 mm x 5.6 mm) was scanned using high-resolution X-ray computed tomography (HRXCT), a nondestructive imaging technology, at a spatial resolution of 4.85 mu m. Combined with three-dimensional (3D) image analysis techniques, the main mineral phases and pore space were segmented and the volume fraction of each phase was calculated. In addition, the mass fraction of each mineral phase was estimated and the result was validated with that obtained using traditional techniques. Furthermore, the pore phase features, including the pore size distribution, pore surface area, pore fractal dimension, pore centerline, and the pore connectivity, were investigated quantitatively. The pore space analysis results indicate that the pore size distribution closely fits a log-normal distribution and that the pore space morphology is complicated, with a large surface area and low connectivity. This study demonstrates that the combination of HRXCT and 3D image analysis is an effective tool for acquiring 3D mineralogical and pore structural data.
文摘Objective. To study the difference of interstitial lung diseases (ILDs) in high-resolution computerized tomography and pulmonary function test among different connective tissue diseases (CTDs). Methods. 209 patients with different CTDs were recruited and underwent lung HRCT and PFT. Eerythrocyte sedimentation rate (ESR), C-reactive protein (CRP), serum ferritin (SF), anti-SSA, and so on were tested. Based on HRCT, a patient was classified into ILD group (CTD+ILD) or non-ILD group (CTD-ILD). HRCT, PFT, and laboratory markers were compared according to CTDs and CTD-associated ILDs. Results. The incidences of ILD were 79.6%, 82.0%, 89.7%, and 97.1% respectively for Rheumatoid arthritis (RA), primary Sjogren’s symptom (pSS), dermatomyositis/polymyositis (DM/PM), and systemic sclerosis (SSc) groups. RA and pSS patients exhibited more nodules, patching, ground-glass opacity, and cord shadow foci in HRCT, DM/PM and SSc patients exhibited more reticular opacity and honeycombing foci. RA and pSS patients exhibited more obstructive ventilatory disorder, small airway dysfunction and emphysema in PFT, and DM/PM and SSc patients exhibited more restrictive ventilatory disorder, mixed ventilatory disorder. ESR, CRP and SF were significantly higher in total CTD+ILD group than in total CTD-ILD group (P = 0.047, 0.006, 0.004, respectively), and higher in different CTD+ ILD groups than in comparable CTD-ILD groups (P = 0.049, 0.048, and 0.023, pSS+ILD, SSc+ILD and RA+ILD compared to pSS-ILD, SSc-ILD and RA-ILD, respectively for ESR, CRP, SF). The positive rate of anti-SSA was significantly higher in DM/PM+ILD group than in DM/PM-ILD group (P = 0.025). Conclusions. The manifestations and incidences of ILDs differ among different CTDs in HRCT and PFT, and inflammation and anti-SSA are positively correlated with ILDs in different CTDs, which provide important evidences for judging disease condition and prognosis.
文摘COVID-19 which is caused by its new type called SARS-CoV-2 is a viral disease predominantly involving the lungs. <b>Objective:</b> To investigate HRCT features of pulmonary disease in COVID-19 in Lahore, Pakistan. <b>Methods:</b> This is a prospective study that involved 127 COVID-19 positive patients (age 18 - 80 years, both genders) through non-probability sampling was conducted at the Radiology Department, Sir Ganga Ram Hospital, Lahore, in 2021. All patients with RT-PCR positive underwent HRCT chest. All findings in HRCT chest were assessed. Confirmed patients had positive HRCT. Excluded situations are low quality of images irrespective of its reason, HRCT indications other than COVID-19 pneumonia, and patients who do not want to participate in the study <b>Results:</b> Considering the exclusion and inclusion criteria, totally 127 COVID-19 confirmed patients ranging age from 18 to 80 years with a mean age of 52 ± 18 years, took part in this study. The most important and common HRCT finding was the multilobar ground-glass pattern which was present in 95% of patients. Other findings including, crazy paving pattern, consolidation, air bronchogram, and bronchiectasis were present in 8.7%, 82%, 63%, and 37% of patients respectively. Pleural effusion seen in 21% patients. 16% of patients had mediastinal lymphadenopathy. <b>Conclusion:</b> In our study, the ground-glass pattern was found to be the most common and important HRCT finding in patients confirmed with COVID-19 pneumonia. This important HRCT pattern is mostly found to be in posterobasal and peripheral subpleural locations. Other than ground-glass pattern, bronchiectasis, and consolidation having the air bronchogram were also reported commonly.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11827808,11874289,and 11804056)the National Science Fund for Distinguished Young Scholars of China(Grant No.11525416)+3 种基金Shanghai Municipal Science and Technology Major Project,China(Grant No.2017SHZDZX01)Shanghai Talent Development Fund(Grant No.2018112)State Key Laboratory of ASIC and System Project(Grant No.2018MS004)China Postdoctoral Science Foundation(Grant No.2019M661334)。
文摘The main challenge in bone ultrasound imaging is the large acoustic impedance contrast and sound velocity differences between the bone and surrounding soft tissue. It is difficult for conventional pulse-echo modalities to give accurate ultrasound images for irregular bone boundaries and microstructures using uniform sound velocity assumption rather than getting a prior knowledge of sound speed. To overcome these limitations, this paper proposed a frequency-domain fullwaveform inversion(FDFWI) algorithm for bone quantitative imaging utilizing ultrasonic computed tomography(USCT).The forward model was calculated in the frequency domain by solving the full-wave equation. The inverse problem was solved iteratively from low to high discrete frequency components via minimizing a cost function between the modeled and measured data. A quasi-Newton method called the limited-memory Broyden–Fletcher–Goldfarb–Shanno algorithm(L-BFGS) was utilized in the optimization process. Then, bone images were obtained based on the estimation of the velocity and density. The performance of the proposed method was verified by numerical examples, from tubular bone phantom to single distal fibula model, and finally with a distal tibia-fibula pair model. Compared with the high-resolution peripheral quantitative computed tomography(HR-p QCT), the proposed FDFWI can also clearly and accurately presented the wavelength scaled pores and trabeculae in bone images. The results proved that the FDFWI is capable of reconstructing high-resolution ultrasound bone images with sub-millimeter resolution. The parametric bone images may have the potential for the diagnosis of bone disease.
文摘Background:?High resolution chest computed tomography (HRCT) is an established imaging modality that accurately assesses disease processes that are non-specific on conventional chest radiography. Chest Computed Tomography (CT) has proven invaluable in the evaluation of various diseases of the chest providing precise diagnosis that have great impact on the course of management. In this study, our aim is to evaluate the spectrum of radiological findings in all patients that had chest CTs at a tertiary health Institution in a developing Country. Method: This is a 6-year retrospective study of all patients that had Chest CT from 2009 till 2015. All patient data were retrieved and their Chest CT images reviewed and radiological findings and diagnosis documented. Results: Age range of patients was 1 - 84 years with a mean of 52.36 ± 22.9 years. Ten patients were children (12%). There were more males 53 (63.1%) than females 31 (36.9%) in the study. Referral for imaging was predominantly from internal medicine 33 (47.1%) and Surgery 27 (38.6%) departments. Most of the patients, 53 (63.1%) did not have previous chest radiographs. Consolidative changes were the most common parenchymal finding (77.4%). Few mediastinal masses were found in the study population. CT angiography constituted only 10.7% of all chest CTs done in adults. Conclusion: Few chest CT evaluations are performed compared to CTs of other parts of the body done in the same period. Chest CT is generally under-utilized even in a tertiary institution. There is a need to educate chest physicians on the role and advantages of CT use for the management of their patients.
基金supported by the National Natural Science Foundation of China (No. 81600164)
文摘Objective: High-dose chemotherapy(HDC) followed by autologous hematopoietic stem cell transplantation(auto-HSCT) plays an important role in improving outcomes of diffuse large B cell lymphoma(DLBCL) patients.18 F-fluorodeoxyglucose(18 F-FDG) positron emission tomography(PET)/computed tomography(CT) has been widely accepted in response assessment and prediction of prognosis in DLBCL. Here, we report the value of 18 FFDG PET/CT pre-and post-HSCT in predicting outcomes of patients with DLBCL.Methods: DLBCL patients who had PET/CT scan before and after HSCT were included. PET results were interpreted based upon Deauville criteria. The prognostic value of 18 F-FDG PET/CT in auto-HSCT was evaluated.Results: Eighty-four patients were enrolled. In univariate analysis, pre-and post-HSCT PET findings were correlated with 3-year progression-free survival(PFS) [hazard ratio(HR)=4.391, P=0.001; HR=7.607, P<0.001] and overall survival(OS)(HR=4.792, P=0.008; HR=26.138, P<0.001). Patients receiving upfront auto-HSCT after firstline treatment had better outcomes than relapsed/refractory DLBCL patients(3-year PFS, P<0.001; 3-year OS,P<0.001). In the relapsed/refractory patients, pre-and post-HSCT PET findings were also associated with 3-year PFS(P=0.003 vs. P<0.001) and OS(P=0.027 vs. P<0.001). A significant correlation was observed between clinical response to chemotherapy before auto-HSCT and outcomes of patients in the entire cohort(3-year PFS, P<0.001;3-year OS, P<0.001) and in the subgroup of 21 patients with positive pre-HSCT PET(3-year PFS, P=0.084; 3-year OS, P=0.240). A significant association between survival and post-HSCT PET findings was observed in multivariate analysis(HR=5.168, P<0.001).Conclusions: PET results before and after HSCT are useful prognostic factors for DLBCL patients receiving HSCT. Patients who responded to chemotherapy, even those with positive pre-HSCT PET, are appropriate candidates for auto-HSCT.
文摘BACKGROUND Pulmonary alveolar microlithiasis(PAM)is a rare idiopathic lung disease characterized by the accumulation of innumerable microliths.Currently,effective therapeutics for PAM are not available,and the only treatment for end-stage lung disease is lung transplantation(LuTx).Further,there are few reports that focus on LuTx for the treatment of PAM,and the follow-up reports of postoperative imaging are even rarer.CASE SUMMARY A 52-year-old man presented to Shanghai Pulmonary Hospital in 2017 after experiencing shortness of breath and exacerbation.The patient was diagnosed with PAM and referred for single-LuTx(SLuTx)on March 14,2018.Preoperative imaging results from a chest X-ray demonstrated bilateral,diffuse,symmetrical,sandstorm-like radiopaque micronodules,and pneumothorax and a computed tomography scan revealed minute,calcified military nodules in both lungs.We performed a left SLuTx,and intraoperative pathology was consistent with PAM.One week after surgery,a chest X-ray revealed slight exudation of the left lung,and one month later,the left transplanted lung exhibited good dilation,mild pulmonary perfusion injury with local infection,and left pleural effusion.Fiberoptic bronchoscopy revealed left hyperplastic granulation at the left bronchial anastomosis.Multiple sputum cultures suggested the presence of Klebsiella pneumoniae and Acinetobacter baumannii.The last follow-up was conducted in April 2019;the patient recovered well.CONCLUSION This case presents the imaging findings of a patient with PAM before and after LuTx and confirms the effectiveness of LuTx for the treatment of this disease.
文摘Modern computer techniques have been in use for several years to generate three-dimensional visualizations of human anatomy. Very good 3-D computer models of the human body are now available and used routinely in anatomy instruction. These techniques are subsumed under the heading “virtual anatomy” to distinguish them from the conventional study of anatomy entailing cadavers and anatomy textbooks. Moreover, other imaging procedures (X-ray, angiography, CT and MR) are also used in virtual anatomy instruction. A recently introduced three-dimensional post-processing technique named Cinematic Rendering now makes it possible to use the output of routine CT and MR examinations as the basis for highly photo-realistic 3-D depictions of human anatomy. We have installed Cinematic Rendering (enabled for stereoscopy) in a high-definition 8K 3-D projection space that accommodates an audience of 150. The space’s projection surface measures 16 × 9 meters;images can be projected on both the front wall and the floor. A game controller can be used to operate Cinematic Rendering software so that it can generate interactive real-time depictions of human anatomy on the basis of CT and MR data sets. This prototype installation was implemented without technical problems;in day-to-day, real-world use over a period of 22 months, there were no impairments of service due to software crashes or other technical problems. We are already employing this installation routinely for educational offerings open to the public, courses for students in the health professions, and (continuing) professional education units for medical interns, residents and specialists—in, so to speak, the dissecting theater of the future.
文摘Background The correct diagnosis of etiology of fungal infection after bone marrow transplantation is very important to the choice of antifungal drugs and a premise for improvement of therapeutic efficacy. This study aimed to compare high-resolution computed tomography （HRCT） findings of the pulmonary fungal infections to determine whether the etiology of various fungal infections could be diagnosed with HRCT. Methods Eighty-five cases were enrolled. According to the pathogens responsible for fungal infections, the patients were classified into three groups including invasive aspergillosis （n=52）, candidiasis （n=19） and cryptococcosis （n=14） groups. All the patients underwent HRCT scans. Two independent radiologists retrospectively analyzed the HRCT scans regarding CT patterns and distribution of lung abnormality. Results Most fungal infections in the three groups occurred in the neutropenic phase. There was no significant difference in the constituent ratio of fungal infections at different phases after bone marrow transplantation among the three groups. Agreement between the two observers for all the CT characteristics of fungal infections was excellent （k 〉0.75）. There was a significant difference in occurrence ratio of mass among the three groups （P=-0.02）. Occurrence ratio of mass （43.3%, 13/30） in the group with invasive aspergillosis was higher than in each of other two groups （20.0%, 2/10; 14.3%, 1/7）. There was no significant difference in other CT characteristics of nodules or masses; including number, margin, halo sign, cavitation and air-crescent sign. There was no significant difference in number, margin, air bronchogram and distribution of air-space consolidation. Conclusions The HRCT appearance of various pulmonary fungal infections has a great deal of overlap and is nonspecific. Mass is more common in invasive aspergillosis, which is helpful to the diagnosis of invasive aspergillosis after bone marrow transplantation.
文摘目的探讨高分辨率CT评估免疫治疗相关性肺炎患者诊疗效果及预后。方法2021年5月至2023年5月于肇庆市第一人民医院进行免疫治疗的恶性肿瘤患者1205例,其中32例治疗后并发免疫相关性肺炎,将所有患者的临床资料进行回顾性分析,对所有患者进行高分辨率计算机断层扫描(CT),分析患者免疫检查点抑制剂治疗情况,免疫相关性肺炎患者临床症状及影像学表现,免疫相关性肺炎出现的时间、诊疗效果及预后。结果14例非小细胞肺癌患者及6例肺部低分化肉瘤样癌均采用纳武力尤单抗注射液静脉滴注治疗,用药剂量为3 mg/kg,治疗频次为每半个月1次;12例非小细胞肺癌患者采用信迪利单抗静脉滴注治疗,剂量为200 mg/次,频次为每21 d 1次。32例免疫相关性肺炎患者的临床分级情况为:2级3例,3级20例,4级9例。12例为对称分布,而20例为非对称分布。患者分型情况如下:20例为磨玻璃型,6例为实变型,6例为网格型。其中有23例伴有胸膜变厚,23例纵隔淋巴结受累,12例伴有支气管扩张,9例伴有小叶间隔变厚,9例伴有多发小叶中心结节,3例伴有胸腔积液。出现免疫相关性肺炎后,32例患者均停止PD-1抑制剂治疗,而应用糖皮质激素连续治疗1~6周,13例出院。结论采用高分辨率CT可以对免疫性肺炎进行诊断,并且有助于对患者进行准确分级、分型,对于已经明确诊断的免疫相关性肺炎患者,应立即停止PD-1抑制剂治疗,之后采用糖皮质激素对患者进行治疗,必要时还可联合抗生素治疗。
