Use of high-resolution X-ray computed tomography and 3D image analysis to quantify mineral dissemination and pore space in oxide copper ore particles

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.

Diagnostic performance of high resolution computed tomography in otosclerosis

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.

High Resolution Computed Tomography Features of Third Wave of COVID-19 Pneumonia in Confirmed Cases

COVID-19 which is caused by its new type called SARS-CoV-2 is a viral disease predominantly involving the lungs. Objective: To investigate HRCT features of pulmonary disease in COVID-19 in Lahore, Pakistan. Methods: 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 Results: 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. Conclusion: 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.

Imaging Findings in Chest Computed Tomography: Initial Experience in a Developing Country

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.

Pulmonary fungal infections after bone marrow transplantation： the value of high-resolution computed tomography in predicting their etiology

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.

Investigation of noise properties in grating-based x-ray phase tomography with reverse projection method

The relationship between noise variance and spatial resolution in grating-based x-ray phase computed tomography（PCT） imaging is investigated with reverse projection extraction method, and the noise variances of the reconstructed absorption coefficient and refractive index decrement are compared. For the differential phase contrast method, the noise variance in the differential projection images follows the same inverse-square law with spatial resolution as in conventional absorption-based x-ray imaging projections. However, both theoretical analysis and simulations demonstrate that in PCT the noise variance of the reconstructed refractive index decrement scales with spatial resolution follows an inverse linear relationship at fixed slice thickness, while the noise variance of the reconstructed absorption coefficient conforms with the inverse cubic law. The results indicate that, for the same noise variance level, PCT imaging may enable higher spatial resolution than conventional absorption computed tomography（ACT）, while ACT benefits more from degraded spatial resolution. This could be a useful guidance in imaging the inner structure of the sample in higher spatial resolution.

Chest radiographic and computed tomographic manifestations in allergic bronchopulmonary aspergillosis

AIM: To investigate the chest radiographic and high resolution computed tomography (HRCT) chest manifestations in glucocorticoid-na?ve allergic bronchopulmonary aspergillosis (ABPA) patients. METHODS: This is a prospective observational study and includes 60 consecutive glucocorticoid-na?ve patients with ABPA who underwent chest radiography and HRCT of the chest (1.25 mm every 10 mm) in the routine diagnostic workup for ABPA. RESULTS: Chest radiographs were normal in 50% of cases. Of the remainder, most patients demonstrated permanent findings in the form of parallel line and ring shadows suggesting bronchiectasis. Consolidation was detected in 17 cases but in the majority, the corresponding HRCT chest scan showed mucus-filled bronchiectatic cavities. Chest HRCT was normal in 22 patients, while central bronchiectasis (CB) was demonstrated in the remaining 38 patients. Bronchiectasis extended to the periphery in 33%-43% depending on the criteria used for defining CB. The other findings observed on HRCT were mucoid impaction, centrilobular nodules and high-attenuation mucus in decreasing order of frequency. CONCLUSION: Patients with ABPA can present with normal HRCT chest scans. Central bronchiectasis cannot be considered a characteristic feature of ABPA as peripheral bronchiectasis is commonly observed. Consolidation is an uncommon finding in ABPA.

High-resolution bone microstructure imaging based on ultrasonic frequency-domain full-waveform inversion

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.

Virtual Anatomy: The Dissecting Theatre of the Future—Implementation of Cinematic Rendering in a Large 8 K High-Resolution Projection Environment

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.

HkV和HRCT检查在职业性尘肺病诊断中的价值

目的探究高千伏胸片(HkV)和高分辨率计算机体层X线摄影术(HRCT)检查在职业性尘肺病诊断中的临床应用价值。方法回顾性分析133例进行职业病诊断的尘肺病患者资料,患者均接受HkV和HRCT检查,以临床病理检查为金标准,比较HkV和HRCT对尘肺患者肺部阴影的显示情况、图片质量、分期诊断符合率及尘肺合并症的检出情况。结果HRCT对肺部P影、小阴影检出率高于HkV(P<0.05),两组大阴影检出率比较,差异无统计学意义(P>0.05);HRCT检查图像质量有效率高于HkV检查(P<0.05);HRCT诊断总准确率高于HkV诊断(P<0.05);HRCT对肺部感染、肺气肿、胸膜增厚、气胸的检出率高于HkV(P<0.05),HRCT与HkV对肺结核、肺大泡检出率差异无统计学意义(P>0.05)。结论HRCT检查对职业性尘肺病患者肺部阴影、临床分期及合并症的诊断效果高于HkV,图片质量更高。

B超、双能CT、细针穿刺在甲状腺乳头状癌术前评估淋巴结转移中的优化选择

目的探寻高分辨率超声检查(B超)、双能计算机断层扫描(DECT)以及细针穿刺抽吸活检(FNAB)在甲状腺癌患者术前淋巴结转移(LNM)诊断时的最佳选择。方法回顾性分析了1174例在南京医科大学第一附属医院行手术治疗的甲状腺乳头状癌患者的资料,术前所有患者均行B超和DECT检查,其中167例患者加做侧区淋巴结FNAB和细针穿刺抽吸物洗脱液甲状腺球蛋白测定(FNA-TG)以评估LNM情况,手术后的常规病理结果作为诊断“金标准”,分析不同情况下甲状腺乳头状癌(PTC)LNM评估方法的最优选择。结果DECT对于中央区淋巴结转移(CLNM)和侧区PTC淋巴结转移(LLNM)预测的灵敏度较B超有显著提高(55.4%vs.44.8%,P<0.001)(90.9%vs.71.6%,P<0.001),B超在LLNM预测的特异性较DECT有优势(72.7%vs.42.7%,P<0.001);B超、DECT联合诊断对CLNM和LLNM的阳性预测准确率较高(91.6%,94.8%),当联合诊断结果不一致时其阳性预测值明显下降(74.3%,63.1%)。此时,增加可疑淋巴结FNAB及FNA-TG检测后其准确率增加至87.9%。结论B超、DECT联合评估是必要的;联合诊断均有转移时,不需要进行额外检查,联合诊断结果不一致时,需要进一步进行淋巴结的FNAB和FNA-TG检测以避免不必要的侧区清扫。

肺高分辨率CT测定支气管壁增厚与慢性阻塞性肺疾病病情严重程度及其疗效的关系

目的:探讨肺高分辨率CT(HRCT)支气管壁增厚与慢性阻塞性肺疾病(COPD)肺功能及其疗效的相关性。方法:回顾性选择2020年1月至2022年12月新疆医科大学附属中医医院收治的慢性阻塞性肺疾病患者154例作为观察组;根据第1秒用力呼气容积的百分比(FEV1%)指标,按照2023版COPD全球倡议(GOLD)分级,其中Ⅰ级51例、Ⅱ级45例、Ⅲ级35例及Ⅳ级23例;另选择同期健康体检者67名作为健康对照组。行胸部HRCT扫描,测定双侧肺尖支气管开口部位支气管壁厚度;采用肺功能测定仪测定第1秒用力呼气容量的百分比(FEV1%)、第1秒用力呼气容积(FEV1)与用力肺活量百分比的比值(FEV1/FVC%);采用Pearson相关性分析软件对支气管壁增厚与肺功能和疗效完成相关性分析。结果:观察组左肺支气管壁厚度(1.49±0.21)mm及右肺支气管壁厚度(1.52±0.24)mm均大于健康对照组,差异有统计学意义(t=18.041、15.504,P<0.05);观察组中不同GOLD分级下患者分级越高,左肺支气管壁厚度及右肺支气管壁厚度越厚,不同分级各亚组之间左、右双肺支气管壁厚度差异亦均有统计学意义(F=13.888、25.841,P<0.05);观察组不同GOLD分级患者慢阻肺患者FEV1(1.82±0.32)、FEV1/FVC%(63.09±5.26)及FEV1%(63.36±6.03)水平低于健康对照组,差异有统计学意义(t=6.693、15.392、7.944,P<0.05);观察组中GOLD分级下患者级别越高,FEV1、FEV1/FVC%及FEV1%水平下降越低,观察组不同GOLD分级患者肺功能水平比较差异有统计学意义(F=166.541、141.751、57.120,P<0.05);Pearson相关性分析结果表明:COPD患者肺HRCT左肺及右肺支气管壁增厚与肺功能FEV1、FEV1/FVC%及FEV1%水平呈正相关性(r=0.451、0.503、0.498、0.531、0.488、0.515,P<0.05)。结论:肺HRCT支气管壁厚度在COPD患者中呈高表达,其表达水平能反映患者病情严重程度,且与肺功能存在强相关性。

MR血管壁成像技术在脑动脉硬化患者中的应用及斑块特征分析

目的 探讨高分辨率血管壁成像技术(high-resolution vessel wall imaging,HR-VWI)在脑动脉硬化患者中的应用及斑块特征。方法 选取我院就诊的疑似脑动脉硬化患者120例,均行多层螺旋CT(multi slice spiral,MSCT)及HRVWI扫描,比较两种扫描技术对脑动脉硬化患者斑块的检出率,并比较轻、中、重度患者之间的差异。再将MRI检出患者分为无症状组56例和有症状组54例,利用MRI软件处理系统,比较两组患者血管和斑块量化指标,如斑块狭窄率、斑块负荷、重构指数、斑块稳定性等。结果 与MSCT相比,HR-VWI可准确检测出有症状组和无症状组患者斑块特征、血管重构率、狭窄率、斑块负荷、斑块稳定性,差异有统计学意义(P<0.05);HR-VWI对非钙化斑块的检出率较高,差异有统计学意义(P<0.05)。结论 MRI HR-VWI技术对脑动脉硬化的诊断效能较高,可准确检测出脑动脉硬化患者的硬化斑块,并能准确分析斑块特征。

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研究

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。

皮肌炎/多发性肌炎相关间质性肺病高分辨率CT特征

目的:探讨皮肌炎(DM)/多发性肌炎(PM)相关间质性肺病(ILD)的高分辨率CT(HRCT)特征。方法:回顾性分析2014年1月至2019年12月间141例合并ILD的DM/PM患者的胸部HRCT征象。结果:DM/PM-ILD的HRCT表现主要包括:磨玻璃影(87.2%,123/141)、小叶间隔增厚(78.0%,110/141)、小叶内间质增厚(63.8%,90/141)、实变(29.0%,41/141)、胸膜下线(26.2%,37/141)、牵拉性支气管扩张(19.9%,28/141)、蜂窝征(3.5%,5/141);其他合并表现还包括纵隔气肿(3例)、胸腔积液(15例)及心包积液(18例);主要的影像分型为非特异性间质性肺炎(NSIP),其次为机化性肺炎(OP)。结论:尽管DM/PM-ILD病变类型复杂,但其影像学表现仍具有一定的特征性,掌握其HRCT主要特征及影像分型有助于该病的早期识别和及时诊治。

结核性中耳炎的HRCT特征

目的 评估结核性中耳炎(TOM)的HRCT特征。方法 回顾性收集经病理证实的TOM病人22例(24耳),其中男8例(36.4%),女14例(63.6%)。分析其临床资料以及HRCT上颞骨气化程度、软组织分布及骨质特点。结果 24耳中,以气化型多见(21耳,87.5%)。中耳软组织表现以完全充满气房(19耳,82.6%)、鼓室(21耳,87.5%)、乳突窦(23耳,95.8%)多见;多数堵塞咽鼓管鼓室口(22耳,91.7%),并可见突入或延伸至外耳道(21耳,87.5%)。蜂房间隔增厚(20耳,86.9%)或模糊多见(17耳,73.9%);骨质破坏也不少见(11耳,45.8%),表现为蜂房间隔中断(7耳,30.4%)、乳突骨皮质破坏(2耳,8.3%)、听骨链破坏(3耳,12.5%)、盾板破坏(2耳,8.3%)、外耳道壁破坏(1耳,4.2%)以及死骨形成(1耳,4.2%)。结论 TOM病人颞骨气化程度好,中耳软组织分布广且易累及咽鼓管和外耳道,蜂房间隔增厚模糊,部分可见骨质破坏。

类风湿性关节炎相关肺间质病变的HRCT表现及危险因素研究

目的:探讨类风湿关节炎(RA)相关间质性肺疾病(ILD)的胸部高分辨率CT(HRCT)表现,并探讨发生RA-ILD的临床及实验室危险因素。方法:根据是否合并ILD将接受胸部HRCT检查的471例连续性RA患者分为RA-ILD(n=273)组和非RA-ILD组(n=198)。分析RA-ILD患者的HRCT表现及两组患者临床资料及实验室指标的差异,并探讨RA患者发生ILD及RA-ILD患者进展为普通间质性肺炎(UIP)的危险因素。结果:RA-ILD组患者年龄更大,男性比例更高(P<0.05),且高血压、糖尿病的发生率更高(P<0.05)。RA-ILD组患者血沉、C反应蛋白、类风湿因子IgM、IgA水平均高于非ILD组(P<0.05)。RA-ILD患者的HRCT以小叶间隔增厚最为常见,其次为胸膜下线、网格影、磨玻璃影及蜂窝影,且蜂窝影多见于男性患者。多因素二分类逻辑回归结果发现年龄增大(OR=1.12,95%CI:1.09~1.15,P<0.001)、男性患者(OR=1.74,95%CI:1.04~2.93,P=0.036)及C反应蛋白增高(OR=1.01,95%CI:1.00~1.01,P=0.022)是发生RA-ILD的独立危险因素。RA-ILD患者中,各临床因素及实验室指标与发生UIP型间质性肺疾病均未见明显相关性。结论:年龄增大、男性及C反应蛋白增高可能是RA患者发生ILD的危险因素,且男性患者发生UIP概率更高。

高分辨率MRI及CT灌注成像定量参数在烟雾病患者中的应用价值

目的探讨高分辨率磁共振成像(HR-MRI)及CT灌注成像(CTP)定量参数在烟雾病患者中的应用价值。方法回顾性分析2020年1月至2023年6月医院68例烟雾病患者、42例脑动脉粥样硬化患者的临床资料。比较2组患者HR-MRI检查定量参数(血管外径、血管外缘面积)、CTP检查定量参数(脑血流量、脑血容量、平均通过时间、达峰时间),绘制受试者工作特征(ROC)曲线分析HR-MRI、CTP定量参数对烟雾病的诊断价值。比较烟雾病患者行血管重建术术前、术后CTP定量参数变化。结果烟雾病患者血管外径、血管外缘面积均小于脑动脉粥样硬化患者(P<0.05)。烟雾病患者脑血流量低于脑动脉粥样硬化患者,平均通过时间、达峰时间均高于脑动脉粥样硬化患者(P<0.05)。绘制ROC曲线显示,血管外径、血管外缘面积、脑血流量、平均通过时间、达峰时间对烟雾病均有一定诊断价值(AUC>0.7,P<0.05),且以HR-MRI中血管外缘面积和CTP中脑血流量诊断价值最高。行血管重建术后,烟雾病患者脑血流量较术前显著升高,平均通过时间、达峰时间均较术前显著降低(P<0.05)。结论HR-MRI、CTP定量参数对于烟雾病的诊断具有一定特征性,能够提高烟雾病的鉴别准确性;此外,CTP定量参数还可用于临床疗效评估。

基于AI评估磨玻璃样肺腺癌浸润性及病理亚型的研究

目的 基于AI(人工智能)评估高分辨计算机断层扫描(HRCT)上表现为磨玻璃样肺腺癌的浸润性及病理亚型。方法 收集经病理证实为肺腺癌的GGN共205例,其中男79例,女126例,平均年龄59.87±11.49岁。根据病理浸润性可分为微浸润性腺癌(MIA)和浸润性腺癌(IA);IA又根据病理亚型分为低危组(含有乳头、贴壁或腺泡型为主且没有微乳头亚型和实体亚型的成分)和高危组(含有微乳头或实体亚型)。AI自动提取结节CT形态学特征并采用密度直方图自动计算结节CT定量指标以综合评估危险度。采用二元logistic回归分析并绘制风险指数的受试者工作特征(ROC)曲线进行评估。结果 经统计分析显示,GGN形态、垂直径、CT平均值是浸润性病变组的独立风险因素,其中GGN垂直径预测浸润性的诊断效能最大;GGN的CT最小值、实性占比、毛刺征是IA中高危组的独立风险因素,其中实性占比预测预后不良的诊断效能最大。结论 基于AI提取GGN的CT形态学特征及定量指标有助于磨玻璃样肺腺癌浸润程度及病理亚型的预测。

不同管电压对超高分辨光子计数探测器CT评估冠状动脉支架的影响:一项体模研究

目的 探讨不同管电压对超高分辨光子计数探测器CT(PCD-CT)评估冠状动脉支架的影响。方法 选取6枚直径约3 mm的不同材质的冠状动脉支架,置入人造模拟冠状动脉血管内,分别采用140 kV和120 kV管电压以相对于扫描设备z轴0°和90°方向对支架行超高分辨PCD-CT扫描。通过不同的扫描和重建参数组合完成144组影像数据的采集。对全部影像进行主观评分及客观影像质量评价。客观影像评价包括支架腔内衰减增加比率(SAIR)、支架的边缘上升距离(ERD)和支架内径。采用Cohen’s Kappa检验评估影像质量主观评分的观察者间一致性。采用配对t检验或Wilcoxon检验比较2种管电压下0°和90°方向支架的影像质量指标。采用多因素广义线性混合效应模型分析高管电压(140 kV)对冠状动脉支架影像定性定量评估的影响。结果 对于0°方向支架,120 kV和140 kV管电压下扫描获得的冠状动脉支架影像的影像质量主观评分、SAIR值、ERD值及支架内径差异均无统计学意义(均P>0.05)。对于90°方向支架,140 kV相比120 kV管电压下的支架影像具有更高的SAIR值、更低的ERD值及更大的支架内径(均P<0.05)。对于0°和90°方向支架,140 kV均可增加SAIR值(均P<0.05);而对于90°方向支架,140 kV还能提高支架内直径测量值,减小ERD值(均P<0.05)。结论 140 kV相较120 kV管电压可降低超高分辨PCD-CT上的冠状动脉支架硬化线束伪影。当冠状动脉支架相对于z轴的角度增加,高管电压可进一步增加支架锐利度及支架内径。但高管电压可增加辐射剂量,临床应用中仍需综合评估。