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Objective:To investigate whether the image quality of total-body PET/CT (TB PET/CT) with 1 min acquisition can meet the clinical diagnostic requirements.Methods:From May 2019 to September 2021, a total of 90 malignant tumor patients (60 males, 30 females, age 31-86 years) with primary lesions confirmed by pathological diagnosis in Zhongshan Hospital, Fudan University were respectively analyzed. All patients underwent conventional PET/CT (C PET/CT) scan with conventional clinical acquisition and TB PET/CT scan with 1 min acquisition after injecting 18F-FDG in random order. Paired t test or Wilcoxon signed rank test was used to analyze the image quality of these two scans. Results:SUV max of primary lesions in TB PET/CT group was significantly higher than that in C PET/CT group (15.9(7.9, 24.6) vs 12.5(5.8, 16.6); z=8.14, P<0.001), so were signal-to-noise ratio (SNR) of the blood pool, liver, muscles (9.3±3.0, 11.4(9.5, 14.2), 8.3(7.3, 10.1) vs 6.2±1.7, 9.4(7.7, 11.8), 6.0(4.9, 7.1)), tumor-to-blood pool ratio (TBR) (9.3(4.3, 14.8) vs 8.5(4.3, 11.1)), tumor-to-liver ratio (TLR) (6.7(3.0, 10.4) vs 6.1(2.9, 7.7)), tumor-to-muscle ratio (TMR) (23.2(11.5, 38.0) vs 18.3(9.6, 26.6); t=9.36, z values: 4.44-7.40, all P<0.001). Conclusion:The image quality of TB PET/CT scan with 1 min acquisition can meet the diagnostic requirements, and is better than the C PET/CT image quality with conventional clinical acquisition.
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Objective:To compare the imaging quality and metabolic quantitative parameters of pulmonary nodules between Q. Flex whole information five-dimensional (5D) and conventional three-dimensional (3D) PET/CT imaging for clinical evaluation.Methods:Fifty-four patients (30 males, 24 females, age: 60(42, 75) years; 78 solid pulmonary nodules (maximum diameter≤3 cm) with abnormal uptake of 18F-FDG) from Tianjin Cancer Hospital Airport Hospital between June 2022 and August 2022 were enrolled in this retrospective study. All patients underwent 5D scanning and 3D, 5D reconstruction. Image quality scores, signal-to-noise ratio (SNR), SUV max, SUV mean and metabolic tumor volume (MTV) of pulmonary nodules of 5D group and 3D group were evaluated and compared with χ2 test and Wilcoxon signed rank test. Correlation of quantitative parameters between 2 groups were analyzed by using Spearman rank correlation analysis. Results:Thirty-five of 78(45%) pulmonary nodules with image quality score≥4 were found in 5D group, which were more than those in 3D group (22/78(28%); χ2=4.67, P=0.031). Meanwhile, SNR, SUV max, SUV mean, and MTV were significantly positively correlated between the 2 groups ( rs values: 0.86, 0.86, 0.85, and 0.95, all P<0.001). SNR, SUV max and SUV mean of pulmonary nodules in 5D group were significantly higher than those in 3D group, which were 37.46(18.42, 62.00) vs 32.72(16.97, 54.76) ( z=-4.07, P<0.001), 9.71(5.48, 13.82) vs 8.96(4.82, 12.63) ( z=-3.05, P<0.001) and 6.30(3.39, 8.94) vs 5.61(2.99, 7.63)( z=-4.07, P<0.001) respectively. MTV of pulmonary nodules in 5D group was significantly lower than that in 3D group, which was 1.72(0.66, 2.74) cm 3vs 1.98(1.06, 4.63) cm 3 ( z=-7.13, P<0.001). Quantitative parameters of lower lung field and nodules with maximum diameters of >10 mm and ≤20 mm based on 5D scanning changed most significantly compared with those based on 3D scanning ( z values: from -5.23 to -2.48, all P<0.05). Conclusion:Q. Flex 5D PET significantly improves the quantitative accuracy of SUV and MTV of pulmonary nodules, and the improvement of image quality is substantial without increasing the radiation dose, which has clinical practical value.
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Dual-tracer PET imaging can provide more comprehensive clinical information for disease diagnosis. How to achieve dual-tracer imaging through single imaging session is one of the hot topics in the field of nuclear medicine. The key issues in achieving dual-tracer imaging with a single scan is the accurate separation of single-tracer information from the mixed tracer signal. In the last two decades, separation methods for different tracers have been proposed, and the injection interval between two tracers was reduced. This paper summarizes recent dual-tracer separation methods. The basic principles, features and advantages of separation methods are analyzed. Besides, the outlook on the future development of dual-tracer separation is also discussed in the present review.
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The incidence of malnutrition in surgical patients is high and affects the clinical outcome of patients. Through the extraction and analysis of image data, radiomics can assess changes in the composition of the body, such as skeletal muscle and fat, and it demonstrates tremendous potential in nutritional screening, assessment, diagnosis, and evaluation of treatment effects, emerging as a crucial evaluation tool in nutritional therapy for surgical patients. Furthermore, radiomics can predict patients' clinical outcomes, providing more precise treatment plans. Therefore, the application of radiomics should be fully emphasized in nutritional therapy for surgical patients to promote their enhanced recovery. With the continuous development and improvement of radiomics technology in the future, its application in nutritional therapy for surgical patients is expected to become more extensive and profound, bringing better treatment outcomes and quality of life to patients.
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Objective:To explore the application value of optical surface monitoring system (OSMS) volume rendering technique (VRT) body surface imaging in intensity-modulated radiotherapy for thoracic tumors.Methods:A retrospective case series study was performed. The clinical data of 65 patients with thoracic tumors treated with intensity-modulated radiotherapy at Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology from September 2021 to October 2022 were retrospectively analyzed. In the first treatment,after cone-beam computed tomography (CBCT) scan and correction, VRT body surface images were obtained by using OSMS. In subsequent treatment, the VRT image was used as the benchmark and the 6-dimensional bed was automatically positioned to record the 6-dimensional bed positioning value. The CBCT scan was performed to record the translation and rotation errors of left-right direction (X-axis), head-foot direction (Y-axis) and front-rear direction (Z-axis). After the calibration of the 6-dimensional automatic bed shifting, the new real-time deltas (RTD) value of digital imaging and communications in medicine (DICOM) body surface image was recorded, and the new VRT image was obtained. CBCT registration error value was defined as VRT image-guided setup error. The sum of CBCT registration error value and moving bed movement value was defined as the body surface marker line-guided setup error. The sum of CBCT registration error value and the recorded DICOM image RTD value was defined as the theoretical error of DICOM image-guided setup. The advantages and disadvantages of VRT image, body surface marker line and DICOM image-guided setup were compared and analyzed.Results:There were 42 males and 23 females in 65 patients with thoracic tumors, and the age [ M ( Q1, Q3)] was 58 years (51 years, 64 years). The linear errors [ M ( Q1, Q3)] of VRT image-guided setup in X, Y and Z axes were 0.6 mm (0.3 mm, 1.2 mm), 1.2 mm (0.5 mm, 2.4 mm) and 1.1 mm (0.5 mm, 1.9 mm); and the rotational errors were 0.4° (0.1°, 0.7°), 0.4° (0.1°, 0.6°) and 0.4° (0.2°, 0.6°). The linear errors of the marker line-guided setup were 1.6 mm (0.9 mm, 2.6 mm), 2.2 mm (1.1 mm, 3.8 mm) and 1.0 mm (0.4 mm, 1.8 mm); and the rotational errors were 0.7° (0.3°, 1.2°), 0.5° (0.2°, 0.8°) and 0.5° (0.2°, 0.8°). The linear errors of the DICOM image-guided positioning were 1.1 mm (0.6 mm, 1.9 mm), 2.1 mm (1.0 mm, 3.4 mm) and 1.3 mm (0.6 mm, 3.1 mm), and the rotational errors were 0.6° (0.2°, 1.1°), 0.7° (0.3°, 1.1°), 0.7° (0.2°, 1.1°). Compared with the marker line-guided setup, except for Z-axis linear error ( P = 0.218), the VRT-guided setup errors were low (all P < 0.001). Compared with the DICOM imaging-guided setup, the VRT image-guided setup linear error and rotational error in X-, Y- and Z-axis were low (all P < 0.01). Conclusions:VRT image-guided setup is superior to traditional body surface marker setup and DICOM imaging setup; OSMS VRT body surface imaging can effectively improve the setup accuracy and stability of intensity-modulated radiotherapy for thoracic tumors, and reduce the setup errors.
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Objective To observe the value of multi-slice spiral CT(MSCT)post-processing technologies for diagnosing otosclerosis.Methods Clinical data and original axial plain MSCT of 47 patients with otosclerosis(92 ears)and 65 patients with non-otosclerosis hearing impairment(79 ears)were retrospectively enrolled.MSCT post-processing images,including multi-planar reformation(MPR)of stapes and cochleas and curved planar reformation(CPR)of ossicular chains were obtained.The diagnostic value of original MSCT images alone and raw data of MSCT combing with post-processing images for diagnosing otosclerosis were compared.Results Otosclerosis was correctly diagnosed in 66 ears according to original MSCT images alone,but in 89 ears combined with MSCT post-processing images.The sensitivity of original MSCT images alone and combined with MSCT post-processing images was 71.74％and 96.74％,respectively,and the diagnostic accuracy was 81.29％and 96.49％,respectively,those of the latter were both higher than of the former(both P＜0.05),which had specificities being not significantly different(92.41％vs.96.20％,P＞0.05).Conclusion Combining with post-processing technologies could increase the sensitivity and accuracy of MSCT for diagnosing otosclerosis.
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Objective To observe the value of SimGrid(SG)and S-Enhance(SE)for improving image quality of low-dose X-ray films in children.Methods Data of 344 children in intensive care unit who underwent 410 times bedside X-ray examinations,including 290 times of chest X-ray,51 of abdominal X-ray and 69 of chest and abdominal combined X-ray were enrolled.SG and SE were respectively used for post-processing,and the quality of post-processed images were analyzed.Results Among 410 SG post-processing images,250 images were classified as 2-point,147 as 1-point and 13 as 0-point.SG could significantly improve image quality of children≥1 year and body mass≥10 kg(all P＜0.05),with better ability for displaying bones,trachea,peripheral blood vessels,foreign objects,psoas major muscle and intestinal gas(all P＜0.05).Among 410 SE post-processing images,250 images were classified as 2-point,58 as 1-point and 102 of 0-point.SE could significantly improve image quality of children≥0.5 years and with body mass＞4 kg(all P＜0.05),with better ability for displaying bones,trachea,large blood vessels,peripheral vessels,heart posterior blood vessels and foreign objects(all P＜0.05).Conclusion SG could significantly improve displaying of bones,trachea,peripheral blood vessels,foreign objects,psoas major muscle and intestinal gas in children≥1 year and body mass≥10 kg,while SE could improve displaying of bones,trachea,large blood vessels,peripheral blood vessels,heart posterior blood vessels and foreign objects in children aged≥0.5 years and body mass＞4 kg on low-dose X-ray films.
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Purpose To evaluate the feasibility of cardiac magnetic resonance fractal analysis in evaluating left ventricular trabecular complexity in hypertrophic cardiomyopathy(HCM),and to study the degree of left ventricular trabecular complexity in HCM and the relationship between excessive trabecular complexity and cardiac function.Materials and Methods From August 2020 to December 2022,a total of 80 patients with HCM from the Second Affiliated Hospital of Nanchang University were retrospectively analyzed.Additionally,80 healthy volunteers were recruited as the control group.Left ventricular functional parameters and fractal dimension(FD)of left ventricular trabecular myocardium were measured.The differences of mean global FD,max basal FD and max apical FD were compared between the HCM group and the control group,the correlation between FDs and cardiac function parameters was evaluated.The diagnostic efficiency of mean global FD,max apical FD and max basal FD was analyzed via receiver operating characteristic curve.Results The mean global FD of HCM group was significantly higher than that of normal group,and the difference was statistically significant(1.303±0.047 vs.1.229±0.026;t=-12.387,P<0.001).Mean global FD showed the best performance in differentiating HCM from normal control group.The optimal cut-off value for the diagnosis of HCM was 1.251,with the area under curve of 0.933(95%CI 0.896-0.969).Mean global FD was positively correlated with maximum wall thickness and left ventricular mass index(r=0.686,0.687,P<0.001),and max apical FD was positively correlated with left ventricular ejection fraction(r=0.520,P<0.001).Conclusion The FD obtained by cardiac magnetic resonance fractal analysis technique is reproducible and has definite value in the diagnosis of HCM,with association with the structure and function of left heart.
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Fundamento: A avaliação da área valvar mitral por meio da reconstrução multiplano na ecocardiografia tridimensional é restrita a softwares específicos e à experiência dos ecocardiografistas. Eles precisam selecionar manualmente o frame do vídeo que contenha a área de abertura máxima da valva mitral, dimensão fundamental para a identificação de estenose mitral. Objetivo: Automatizar o processo de determinação da área de abertura máxima da valva mitral, por meio da aplicação de Processamento Digital de Imagens (PDI) em exames de ecocardiograma, desenvolvendo um algoritmo aberto com leitura de vídeo no formato avi. Método: Este estudo piloto observacional transversal foi realizado com vinte e cinco exames diferentes de ecocardiograma, sendo quinze com abertura normal e dez com estenose mitral reumática. Todos os exames foram realizados e disponibilizados por dois especialistas, com autorização do Comitê de Ética em Pesquisa, que utilizaram dois modelos de aparelhos ecocardiográficos: Vivid E95 (GE Healthcare) e Epiq 7 (Philips), com sondas multiplanares transesofágicas. Todos os vídeos em formato avi foram submetidos ao PDI através da técnica de segmentação de imagens. Resultados: As medidas obtidas manualmente por ecocardiografistas experientes e os valores calculados pelo sistema desenvolvido foram comparados utilizando o diagrama de Bland-Altman. Observou-se maior concordância entre valores no intervalo de 0,4 a 2,7 cm². Conclusão: Foi possível determinar automaticamente a área de máxima abertura das valvas mitrais, tanto para os casos advindos da GE quanto da Philips, utilizando apenas um vídeo como dado de entrada. O algoritmo demonstrou economizar tempo nas medições quando comparado com a mensuração habitual. (AU)
Background: The evaluation of mitral valve area through multiplanar reconstruction in 3-dimensional echocardiography is restricted to specific software and to the experience of echocardiographers. They need to manually select the video frame that contains the maximum mitral valve opening area, as this dimension is fundamental to identification of mitral stenosis. Objective: To automate the process of determining the maximum mitral valve opening area, through the application of digital image processing (DIP) in echocardiography tests, developing an open algorithm with video reading in avi format. Method: This cross-sectional observational pilot study was conducted with 25 different echocardiography exams, 15 with normal aperture and 10 with rheumatic mitral stenosis. With the authorization of the Research Ethics Committee, all exams were performed and made available by 2 specialists who used 2 models of echocardiographic devices: Vivid E95 (GE Healthcare) and Epiq 7 (Philips), with multiplanar transesophageal probes. All videos in avi format were submitted to DIP using the image segmentation technique. Results: The measurements obtained manually by experienced echocardiographers and the values calculated by the developed system were compared using a Bland-Altman diagram. There was greater agreement between values in the range from 0.4 to 2.7 cm². Conclusion: It was possible to automatically determine the maximum mitral valve opening area, for cases from both GE and Philips, using only 1 video as input data. The algorithm has been demonstrated to save time on measurements when compared to the usual method. (AU)
Sujet(s)
Humains , Valvulopathies/mortalité , Valve atrioventriculaire gauche/physiopathologie , Valve atrioventriculaire gauche/imagerie diagnostique , Sténose mitrale/étiologie , Traitement d'image par ordinateur/méthodes , Doxorubicine/effets des radiations , Échocardiographie transoesophagienne/méthodes , Échocardiographie tridimensionnelle/méthodes , Remplacement valvulaire aortique par cathéter/méthodes , Isoprénaline/effets des radiations , Valve atrioventriculaire gauche/chirurgieRÉSUMÉ
Objective:To investigate the changes in gray matter volume (GMV) and abnormalities in structural covariant network (SCN) patterns in patients with chronic pontine infarction (PI).Methods:Patients with unilateral chronic PI (case group) with the first onset admitted to the First Affiliated Hospital of Zhengzhou University and Tianjin Medical University General Hospital from October 2014 to June 2021 were prospectively included. At the same time, healthy subjects matched with age, gender and education years (normal control group) were included. High-resolution three-dimensional T 1 structural MRI images and behavioral scores of the subjects were collected. The voxel-based morphometry and two-sample t test were used to explore the differences in GMV between the groups. Using GMV differential brain regions as seed points, SCN was constructed to explore the abnormality of structural covariant patterns in patients with PI. Spearman rank correlation analysis was used to analyze the correlation between GMV in differential brain regions and behavioral scores. Results:A total of 60 patients with PI were enrolled, including 33 left PI and 27 right PI, while 34 healthy controls were also enrolled. Compared with the normal control group, the GMV in bilateral posterior cerebellar lobe decreased significantly in the left PI group, and the GMV in left anterior and posterior cerebellar lobes and the right posterior cerebellar lobe decreased significantly in the right PI group (Gaussian random field correction with voxel level P<0.001 and cluster level P<0.05, cluster voxel >20), and there was a significant correlation between GMV values in the left anterior and posterior cerebellar lobes and the right posterior cerebellar lobe and the motor function score ( P<0.05). In addition, compared with the normal control group, the right PI group had broader covariate brain regions and a significant increase in the number of structural connections between covariate brain regions (family-wise error correction with voxel level P<0.05, cluster voxel >20). Conclusions:The GMV in bilateral posterior cerebellar lobe decreases significantly in patients with chronic PI, and were secondary to broader covariate brain regions and structural connections. This may be the neural mechanism of impaired behavioral function in patients with PI.
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Objective:To investigate the diagnostic value of thin-layer three-dimensional reconstruction technology combined with personalized scanning for benign and malignant solid solitary pulmonary nodules.Methods:The clinical data of 140 patients with solid solitary pulmonary nodules admitted to Jiangshan People's Hospital form January 2020 to July 2021 were retrospectively analyzed. These patients consisted of 40 patients with benign solid solitary pulmonary nodules (benign group) and 100 patients with malignant solid solitary pulmonary nodules (malignant group). All patients underwent thin-layer three-dimensional reconstruction combined with personalized scanning. The pulmonary nodule signs achieved by thin-layer three-dimensional reconstruction combined with personalized scanning and the diagnostic performance of the combined technology were compared between benign and malignant groups.Results:The proportions of patients with lung cavity sign, lobular sign, vascular convergence sign, vacuole sign, emphysema distribution sign, split pleura sign, and distal perforating vascular sign in the malignant group were 11.0%, 81.0%, 77.0%, 49.0%, 6.0%, 10.0% and 31.0%, respectively, and they were 42.5%, 62.5%, 55.0%, 27.5%, 20.0%, 32.5%, and 5.0%, respectively in the benign group ( χ2 = 15.80, 5.00, 5.66, 4.55, 4.76, 8.96, 9.33, all P < 0.05). The most sensitive sign was lobular sign, which had the highest efficiency, up to 82.0%, in differentiating benign and malignant pulmonary nodules. Conclusion:Lung cavity sign, lobular sign, vascular convergence sign, vacuole sign, emphysema distribution sign, split pleura sign, and distal perforating vascular sign differ greatly between patients with benign and malignant solid solitary pulmonary nodules. Lobular sign has the highest sensitivity in differentiating benign and malignant solid solitary pulmonary nodules. Thin-layer three-dimensional reconstruction combined with personalized scanning has a diagnostic value for benign and malignant solid solitary pulmonary nodules.
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Objective:To explore the impact of different segmentation methods on differential diagnostic efficiency of 18F-FDG PET/MR radiomics to distinguish Parkinson′s disease (PD) from multiple system atrophy (MSA). Methods:From December 2017 to June 2019, 90 patients (60 with PD and 30 with MSA; 37 males, 53 females; age (55.8±9.5) years) who underwent 18F-FDG PET/MR in Union Hospital, Tongji Medical College, Huazhong University of Science and Technology were retrospectively collected. Patients were randomized to training set and validation set in a ratio of 7∶3. The bilateral putamina and caudate nuclei, as the ROIs, were segmented by automatic segmentation of brain regions based on anatomical automatic labeling (AAL) template and manual segmentation using ITK-SNAP software. A total of 1 172 radiomics features were extracted from T 1 weighted imaging (WI) and 18F-FDG PET images. The minimal redundancy maximal relevance (mRMR) and least absolute shrinkage and selection operator (LASSO) algorithm were used for features selection and radiomics signatures (Radscore) construction, with 10-fold cross-validation for preventing overfitting. The diagnostic performance of the models was assessed by ROC curve analysis, and the differences between models were calculated by Delong test. Results:There were 63 cases in training set (42 PD, 21 MSA) and 27 cases in validation set (18 PD, 9 MSA). The Radscore values were significantly different between the PD group and the MSA group in all training set and validation set of radiomics models ( 18F-FDG_Radscore and T 1WI_Radscore) based on automatic or manual segmentation methods ( z values: from -5.15 to -2.83, all P<0.05). ROC curve analysis showed that AUCs of 18F-FDG_Radscore and T 1WI_Radscore based on automatic segmentation in training and validation sets were 0.848, 0.840 and 0.892, 0.877, while AUCs were 0.900, 0.883 and 0.895, 0.870 based on manual segmentation. There were no significant differences in training and validation sets between Radiomics models based on different segmentation methods ( z values: 0.04-0.77, all P>0.05). Conclusions:The 18F-FDG PET/MR radiomics models based on different segmentation methods achieve promising diagnostic efficacy for distinguishing PD from MSA. The radiomics analysis based on automatic segmentation shows greater potential and practical value in the differential diagnosis of PD and MSA in view of the advantages including time-saving, labor-saving, and high repeatability.
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Objective:To explore the added value of T 1-weighted stack-of-stars volumetric interpolated body examination (StarVIBE) sequence on PET/MR image quality. Methods:A retrospective analysis was performed on 60 patients (42 males, 18 females; age 11-86 (58±12) years) who underwent 18F-FDG PET/MR examination and with positive PET results in Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from April 2020 to April 2021. All patients completed StarVIBE sequence collection, and volumetric interpolated body examination (VIBE) sequence was used as control. StarVIBE and VIBE sequence images were evaluated independently using five-point method by two physicians. The evaluation was carried out from six aspects: lesion display, lesion boundary display, vascular around lesions display, fusion level with PET image, image artifact and overall image quality. Wilcoxon signed rank test was used to compare the image quality of the two sequences, and Kappa test was performed to assess the consistency of the image quality scores between the two physicians. Results:There were 26 cases with cervical lesions, 14 cases with chest lesions, 7 cases with abdomen lesions and 13 cases with pelvic lesions. The scores of lesion display (4.0(3.8, 4.5) vs 3.5(3.0, 4.0)), lesion boundary display (4.0(4.0, 4.0) vs 3.0(3.0, 3.5)), vascular around lesions display (5.0(4.0, 5.0) vs 4.0(3.5, 4.5)), fusion level with PET image (5.0(5.0, 5.0) vs 4.5(4.0, 5.0)), image artifact (4.5(4.0, 5.0) vs 4.5(4.0, 5.0)) and overall image quality (5.0(4.0, 5.0) vs 4.0(4.0, 4.0)) of StarVIBE sequences were better than those of VIBE sequences ( z values: 3.77-6.54, all P<0.001). On the vascular around the lesions display, the scores of StarVIBE were significantly better than those of VIBE sequence in the neck (5.0(4.5, 5.0) vs 3.0(2.7, 3.5); z=4.49, P<0.001) and chest (4.5(4.3, 4.7) vs 4.0(3.6, 4.3); z=3.10, P=0.002). As for image quality, the scores of StarVIBE were also significantly better than those of VIBE in neck (5.0(4.5, 5.0) vs 4.0(3.7, 4.5); z=4.36, P<0.001) and chest (5.0(5.0, 5.0) vs 4.0(4.0, 4.5); z=3.02, P=0.003). In abdominal lesions, the score of StarVIBE was higher than that of VIBE in blood vessels (4.5(3.5, 5.0) vs 4.0(3.5, 4.5); z=2.07, P=0.038), and there was no difference between score of overall image quality (4.0(3.7, 4.5) vs 4.0(3.5, 4.5); z=0.27, P=0.785). The score of overall image quality of pelvic StarVIBE sequence was better than that of VIBE sequence (5.0(4.5, 5.0) vs 4.0(4.0, 4.5); z=2.12, P=0.034). Kappa value of image quality score between two physicians was 0.554, indicating moderate consistency. Conclusion:In whole-body PET/MR imaging, StarVIBE sequence can significantly improve the image quality of cervical, thoracic and pelvic lesions when comparing with VIBE sequence.
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Objective:To establish standard spatial brain template and ROIs template of 11C-methyl- N-2β-carbomethoxy-3β-(4-fluorophenyl)tropane (CFT) PET images for automated quantitative analysis of dopamine transporter (DAT) distribution. Methods:From May 2014 to December 2015, 11C-CFT PET and MRI T 1 brain images of 16 healthy volunteers (3 males, 13 females; age (63.3±6.9) years) from Huashan Hospital, Fudan University were co-registered and smoothed using statistical parametric mapping(SPM)5 software based on MATLAB to create a standard spatial brain template. The ROIs template was established by ScAnVp procedures. These templates were clinically verified by using 11C-CFT PET images of 37 healthy volunteers (23 males, 14 females; age (61.7±7.1) years), 32 Parkinson′s disease (PD) patients (20 males, 12 females; age (61.1±5.4) years), 10 multiple system atrophy with predominant parkinsonism (MSA-P) patients (7 males, 3 females; age (60.8±7.1) years) and 10 progressive supranuclear palsy (PSP) patients (5 males, 5 females; age (58.4±6.1) years) from Huashan Hospital, Fudan University between January 2014 and March 2019. One-way analysis of variance was used to analyze data. Results:Based on the 11C-CFT PET images and MRI T 1 images of healthy volunteers, a standard spatial brain template for normalization of 11C-CFT PET images was created. The ROIs template was established including seven regions: bilateral caudate, anterior putamen, posterior putamen (along the long axis) and the occipital cortex. The ROIs template was accurately aligned in each verification group. The normal reference values of semi-quantitative DAT distribution in caudate, anterior putamen and posterior putamen were obtained (1.84±0.13, 2.18±0.16, 1.77±0.11). The semi-quantitative values of 11C-CFT uptake in each ROI in patients were significantly lower than those in healthy volunteers ( F values: 49.79-283.83, all P<0.05). Conclusion:The established brain templates with accurate spatial alignment for 11C-CFT image analysis can provide foundational tools for the application of 11C-CFT PET imaging in clinical practice and scientific research.
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Objective:To investigate the effects of silicon photomutipliers (SiPM) detector and Bayesian penalized likelihood (BPL) reconstruction algorithm on semiquantitative parameters of 18F-FDG PET/CT and diagnostic efficiency for solitary pulmonary nodules/masses compared with traditional photomultiplier tube (PMT) and ordered subsets expectation maximization (OSEM). Methods:From March 2020 to January 2022, 118 patients (76 males, 42 females, age (63.0±10.1) years) newly diagnosed with solitary pulmonary nodules/masses in First Hospital of Shanxi Medical University were prospectively enrolled and underwent 18F-FDG PET/CT imaging with two different PET/CT scanners successively. The images were divided into PMT+ OSEM, SiPM+ OSEM and SiPM+ BPL groups according to PET detector and reconstruction algorithms. The SUV max, SUV mean, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of pulmonary nodules/masses were measured, then signal-to-noise ratio (SNR) and signal-to-background ratio (SBR) were calculated. One-way analysis of variance and Kruskal-Wallis rank sum test were performed to compare differences of above parameters among groups. ROC curve analysis was used to analyze the optimal threshold of SUV max for the differential diagnosis of pulmonary nodules/masses and AUCs were obtained. Results:There were 83 malignant nodules and 35 benign nodules. The image quality of SiPM+ BPL group (4.23±0.64) was better than that of SiPM+ OSEM group (3.57±0.50) or PMT+ OSEM group (3.58±0.51; F=54.85, P<0.001). There were significant differences in SUV max (7.57(3.86, 15.61) vs 4.95(2.22, 10.48)), SUV mean (4.43(2.28, 9.12) vs 2.84(1.21, 5.71)), MTV (3.54(1.57, 7.67) vs 5.09(2.83, 11.79)), SNR (28.12(12.55, 54.38) vs 20.16(8.29, 41.45)) and SBR (4.03(1.83, 7.75) vs 2.32(0.96, 5.03)) between SiPM+ BPL and SiPM+ OSEM groups ( H values: 16.63-37.05, all P<0.001). The optimal threshold values of SUV max in SiPM+ BPL, SiPM+ OSEM and PMT+ OSEM were 3.31, 2.21, 2.05 with AUCs of 0.686, 0.689, 0.615 for nodules < 2 cm, and were 10.29, 6.49, 4.33 with AUCs of 0.775, 0.782, 0.774 for nodules/masses ≥2 cm. Conclusions:Image quality and parameters of pulmonary nodules/masses are mainly affected by the reconstruction algorithms. BPL can improve SUV max, SUV mean, SBR and SNR, but reduce MTV without significant effect on liver parameters. SiPM+ BPL has a higher diagnostic threshold of SUV max than SiPM+ OSEM and PMT+ OSEM.
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Objective:To explore values and differences of multi-modality image registration and normalization methods in 18F-AV45 PET quantitative analysis of Alzheimer′s disease (AD). Methods:Twenty AD patients (10 males, 10 females; age (77.0±5.8) years) and 20 normal controls (NC; 8 males, 12 females; age (75.2±4.8) years) from the AD neuroimaging initiative (ADNI) open database of the National Institute on Aging were analyzed. β-amyloid (Aβ) deposition (positive/negative) was assessed by visual analysis. The SUV ratio (SUVr) in each brain region and individual average SUVr were calculated using template normalization method (M1), normalization after registration with 18F-FDG PET or MRI image (M2 or M3) respectively with the cerebellum as the reference area. The intra-class correlation coefficient (ICC) was used to complete the reliability between methods, and independent-sample t test and one-way repeated measures analysis of variance were used to compare the differences of quantitative indexes between different groups and different methods. ROC curve analysis was used to compare the diagnostic efficacy in distinguishing AD and NC, Aβ positive and negative cases. Results:There were 15 and 6 patients with positive Aβ deposition in AD group and in NC group respectively by visual analysis. The SUVrs of three methods were with good consistency (ICC=0.82, P<0.001), and the differences among individual average SUVrs (1.29±0.17, 1.36±0.23, 1.45±0.24) were significant ( F=68.78, P<0.001). There were significant differences between AD group (1.39±0.17, 1.48±0.24, 1.58±0.25) and NC group (1.20±0.10, 1.24±0.15, 1.33±0.16; t values: 3.55-4.33, all P<0.05), Aβ positive group (1.39±0.16, 1.50±0.21, 1.59±0.23) and negative group (1.19±0.11, 1.21±0.14, 1.31±0.15; t values: 4.58, 5.11, 4.41, all P<0.001), and the individual average SUVr of M3 was higher (both P<0.001). The AUCs of distinguishing Aβ positive and negative deposition of M1-M3 were 0.86, 0.88, 0.84 and the thresholds of SUVrs were 1.29, 1.37, 1.52, respectively. Conclusion:The three multi-modality registration and normalization methods are reliable methods for quantitation of 18F-AV45 PET imaging with certain differences, and should be selected carefully based on data conditions in practice.
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Objective:To study the impact of different scattering correction algorithms in the reconstruction of PET/CT images on image artifacts and the precision of quantitative parameters.Methods:The phantom as described in the National Electrical Manufacturers Association (NEMA) NU2 standard was filled with 18F. The background activity was fixed, and the activity of the solution in the spheres was adjusted to obtain several configurations, including the normal ratio group (4.08∶1) and the extreme ratio group (200∶1). The surface contamination group with the same ratio as the extreme ratio group contained a small radioactive source with different doses of 18F (74, 37, 3.7 and 0.37 MBq) placed at the surface of the phantom. PET/CT images of 30 patients (21 males, 9 females, age: (44.5±10.2) years) from Peking University Cancer Hospital & Institute between July 2012 and December 2021 were retrospectively analyzed, including 10 with normal images ( 18F-FDG) and 20 with abnormal images (10 with dislocation during acquisition, 10 with surface contamination). The images were reconstructed with relative and absolute scattering correction. The phantom was evaluated using the target to background ratio (TBR) and the artifact classification. CV as well as the artifact classification were used to compare the clinical image quality. Mann-Whitney U test and χ2 test were used to analyze data. Results:In the normal ratio group and the extreme ratio group, the TBRs of phantom images reconstructed with relative correction were significantly higher than those with absolute correction (normal ratio group: 3.30(1.94, 4.53) vs 2.72(1.56, 3.56); z=-2.20, P=0.028; extreme ratio group: 105.47(45.62, 162.82) vs 101.36(43.96, 155.57); z=-1.99, P=0.046). In the surface contamination group, with the increase of the activity of the small source, the artifact became more obvious, and the artifact classification score of absolute correction was significantly better than that of relative correction (1.5(1.0, 2.0) vs 2.5(2.0, 3.0); z=-2.00, P=0.046). In the 10 normal 18F-FDG PET/CT patients, the CVliver of the relative correction (9.67%(8.00%, 11.00%)) was significantly lower than that of absolute correction (11.00%(9.00%, 12.00%); z=-2.57, P=0.010), indicating the higher image quality of images with relative correction. In abnormal images, the image quality of absolute correction was significantly higher than that of relative correction with fewer and less severe artifacts (dislocation cases: 9/10 vs 4/10; χ2=5.50, P=0.019; surface contamination cases: 9/10 vs 4/10; χ2=5.50, P=0.019). Conclusions:The relative scattering correction is suitable for normal situations in clinical PET acquisition. However, with dislocation or surface contamination, the absolute scattering correction helps to reduce the artifacts and improve the image quality.
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Objective:To study whether Bayesian penalized likelihood (BPL) and its optimized reconstruction algorithm can improve the reconstructed image quality of low count total-body PET.Methods:Eight patients (5 males, 3 females, age (67.2±6.3) years) who underwent hybrid 18F-FDG PET/MR total-body scans at Department of Nuclear Medicine in Union Hospital, Tongji Medical College, Huazhong University of Science and Technology were collected retrospectively from January to June in 2023. Total-body PET/MR images of them were included and list-mode data were reconstructed with four methods, namely 25% counts conventional reconstruction (group 1), 100% counts conventional reconstruction (group 2), 25% counts BPL reconstruction (group 3), and 25% counts optimized BPL reconstruction (group 4). At last, 32 total-body PET images were obtained. SUV max and SUV mean in different ROIs and tumor metabolic volume (MTV) were measured. Total lesion glycolysis (TLG) and parameters of image quality including the ratio of lesion to background (L/B) and image signal-to-noise ratio (SNR) were calculated. Then the differences in all the parameters among the four groups were analyzed by repeated measures analysis of variance and Friedman test. Quantitative differences between BPL reconstruction and optimized BPL with the 100% counts conventional reconstruction were compared respectively by using the Bland-Altman (BA) plot. Results:For the inter-group comparison, except for SUV mean in the muscle ( F=0.38, P=0.767), SUV max and SUV mean in other ROIs were statistically different ( F values: 8.15-36.08, χ2=18.15, all P<0.01), as well as MTV and L/B ( χ2 values: 10.65, 13.35, P values: 0.014, 0.004), but not for TLG ( χ2=4.95, P=0.175) or SNR ( F=2.64, P=0.076). For the pairwise comparison, the differences between group 2 and group 3 were the most significant (all P<0.05). Compared with group 2, there were no significant differences for SUV max and SUV mean of the cerebellar cortex and lesions in group 4 (all P>0.05), as well as MTV and L/B (both P>0.05). In addition, compared with group 1, SUV max of liver and muscle in group 2 were decreased (both P<0.05), while there were no significant differences in group 4 (all P>0.05). BA plots showed that the differences of SUV, MTV, and TLG between group 4 and group 2 were smaller obviously than those between group 3 and group 2. Conclusion:BPL reconstruction can improve low focus detection sensitivity induced by low counts, but it will cause significant changes for PET quantification, which can be solved by optimized BPL reconstruction.
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RESUMEN Fundamento: el procesamiento de imágenes es clave en la planificación de tratamientos de radioterapia con haces externos. En su ejecución pueden ocurrir errores humanos y fallos de equipos, que conllevan, entre otros efectos, a interpretaciones erróneas de imágenes diagnósticas, errores de contorneo de blancos, sobredosis a tejidos sanos o subdosis a tejidos tumorales, lo cual significa poner en riesgo a los pacientes sometidos a estas prácticas. Objetivo: caracterizar los riesgos asociados a los factores tecnológicos y humanos relacionados con el procesamiento de imágenes que pueden afectar a los pacientes sometidos a tratamientos de radioterapia con haces externos. Métodos: como base de estudio se empleó la práctica de radioterapia de intensidad modulada. Para caracterizar los iniciadores y las medidas de defensa relacionados con este procesamiento, se emplearon modelos de riesgo basados en análisis de modos y efectos de fallo y matriz de riesgo de la práctica de referencia, que fueron procesados con el software SECURE-MR-FMEA. Resultados: los análisis de sensibilidad sobre los modelos de radioterapia de intensidad modulada mostraron los efectos sobre el riesgo de los fallos asociados al procesamiento de imágenes. Conclusiones: se confirmó la importancia de aplicar el análisis de riesgo en el procesamiento de imágenes para elevar la seguridad de los pacientes durante los tratamientos de radioterapia con haces externos.
ABSTRACT Background: image processing is the key in planning external beam radiotherapy treatments. In its execution, human errors and equipment failures can occur, which lead, among other effects, to erroneous interpretations of diagnostic images, target contouring errors, overdose of healthy tissues or underdose of tumor tissues, which means putting patients at risk patients subjected to these practices. Objective: to characterize the risks associated with technological and human factors related to image processing that can affect patients undergoing radiotherapy treatments with external beams. Methods: intensity modulated radiotherapy was used as the basis of the study. To characterize the initiators and defense measures related to this processing, risk models were used based on analysis of failure modes and effects and the risk matrix of the reference practice, which were processed with the SECURE-MR-FMEA software. Results: the sensitivity analyzes on the intensity-modulated radiotherapy models showed the effects on the risk of failures associated with image processing. Conclusions: the importance of applying risk analysis in image processing to increase patient safety during external beam radiotherapy treatments was confirmed.
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RESUMEN Fundamento: en los laboratorios de microbiología, la identificación y conteo de microorganismos es un procedimiento habitual. Aunque existen en el mercado equipos que posibilitan su realización de manera automática o semiautomática, son muy costosos, por lo cual esta tarea, difícil e irritante para los ojos, la siguen realizando los expertos de manera tradicional mediante la observación de las muestras en los microscopios, con la consiguiente variabilidad entre ellos. Objetivo: proponer un nuevo método para el conteo de bacterias y levaduras en imágenes digitales, bajo diferentes magnificaciones, tomadas a bioproductos de origen microbiano obtenidos por fermentación. Métodos: el sensor empleado para la toma de imágenes de las muestras fue una cámara digital modelo HDCE-X, con un sensor CMOS de ½", con una resolución de 2592 píxeles por 1944 píxeles (5 Mp). Se emplearon dos tipos de magnificaciones: magnificación 40x (PL40, 0.65 apertura numérica and 0.17 de distancia de trabajo) y magnificación 100x (HI plan 100/1.25 con inmersión de aceite). El método propuesto se basa en técnicas de procesamiento digital de imágenes, utilizando herramientas como la detección de contornos, operaciones morfológicas y análisis estadístico, y fue desarrollado en lenguaje Python con empleo de la biblioteca OpenCV. Resultados: la detección y conteo de bacterias se logró con una exactitud y precisión aceptable, en ambos casos por encima de 0,95; no en el caso de las levaduras cuya exactitud y precisión fueron menores, alrededor de 0,78 y 0,86 respectivamente. Se proponen flujos de trabajo basados en técnicas de procesamiento digital de imágenes, fundamentalmente en detección de contornos, operaciones morfológicas y análisis estadístico. Conclusiones: el método posee una efectividad aceptable para el contexto y depende de las características que presenten las imágenes.
ABSTRACT Background: In microbiology laboratories, the identification and counting of microorganisms is a common procedure; and although there is a variety of equipment on the market that possibility to carry out these processes automatically or semi-automatically, it is usually expensive to many laboratories. These are some of the reasons why this arduous and difficult task is still performed in many laboratories by experts in the traditional way, through the observation of samples in microscope, consuming a great time and having variations in the results between experts. Objective: The present work aims to propose a new method for counting bacteria and yeasts in digital images, taken under different magnifications, of microbial bioproducts obtained by fermentation. Methods: The sensor used to take images of the samples was a digital camera model HDCE-X, with a ½" CMOS sensor, with a resolution of 2592 pixels by 1944 pixels (5 Mp). Two types of magnifications were used: 40x magnification (PL40, 0.65 numerical aperture and 0.17 working distance) and 100x magnification (HI plan 100/1.25 with oil immersion). The proposed method is based on digital image processing technics, using tools as contour detection, morphological operations and statistical analysis, and was developed in Python language using the OpenCV library. The work also presents a comparison with the results obtained using ImageJ software for the same purpose. Results: the detection and count of bacteria was achieved with an acceptable accuracy and precision, in both cases above 0.95; not in the case of yeasts whose accuracy and precision was lower, around 0.78 for accuracy and 0.86 for precision. Workflows based on digital image processing techniques are proposed, using tools as contour detection, morphological operations and statistical analysis. Conclusions: the method has an acceptable effectiveness for the context and depends on the characteristics presented by the images.