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Performance of machine learning implementation in cone beam computed tomography of oral and maxillofacial area

A scoping review will be conducted following the guidelines of the JBI manual. Additionally, to report the results, the PRISMA Statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) will be used, to identify the evidence on the level of diagnostic accuracy offered by ultrasound images compared to (CT) for the detection of peri-implant aesthetic complications in dentistry, through the PACO strategy: P= Patients with peri-implant complications; A= ultrasonography; C= Computed tomography; O= Diagnostic accuracy

This article is from BMC Cancer , volume 13 . Abstract Background: Human and feline head and neck squamous cell carcinoma (HNSCC) share histology, certain molecular features, as well as locally aggressive and highly recurrent clinical behavior. In human HNSCC, the presence of significant hypoxia within these tumors is considered an important factor in the development of a more aggressive phenotype and poor response to therapy. We hypothesized that feline head and neck tumors, particularly HNSCC, would exhibit hypoxia and that 64Cu-diacetyl-bis(N4-methylthiosemicarbazone) (Cu-ATSM) positron emission tomography/computed tomography (PET/CT) would permit detection of intratumoral hypoxia. Methods: 12 cats with measureable head and neck tumors were given 64Cu-ATSM and iodinated contrast for PET/CT scan. The presence or absence of hypoxia was also assessed using an intratumoral fluorescent life-time probe to quantitate pO2 and pimonidazole immunohistochemical staining in biopsy specimens. In two cats, intratumoral O2 and 64Cu-ATSM uptake was measured before and after treatment with anti-angiogenic agents to determine the effect of these agents on hypoxia. Results: Eleven of twelve feline tumors demonstrated significant 64Cu-ATSM uptake, regardless of malignant or benign etiology. The presence (and absence) of hypoxia was confirmed using the fluorescent O2 detection probe in nine tumors, and using pimonidazole staining in three tumors. Squamous cell carcinomas (HNSCC) demonstrated the highest degree of hypoxia, with Tmax/M ratios ranging from 4.3 to 21.8. Additional non-neoplastic tissues exhibited 64Cu-ATSM uptake suggestive of hypoxia including reactive draining lymph nodes, non-malignant thyroid pathology, a tooth root abscess, and otitis media. In two cats with HNSCC that received anti-vascular agents, the pattern of 64Cu-ATSM uptake was altered after treatment, demonstrating the potential of the feline model to study the modulation of tumor oxygenation. Conclusion: Feline HNSCC serves as a clinically relevant model for the investigation of intratumoral hypoxia including its measurement, modulation and targeting.

This article is from Indian Journal of Nuclear Medicine : IJNM : The Official Journal of the Society of Nuclear Medicine, India , volume 29 . Abstract Accessory navicular bone is one of the supernumerary ossicles in the foot. Radiography is non diagnostic in symptomatic cases. Accessory navicular has been reported as a cause of foot pain and is usually associated with flat foot. Increased radio tracer uptake on bone scan is found to be more sensitive. We report a case highlighting the significance of single photon emission tomography/computed tomography in methylene diphosphonate bone scan in the evaluation of symptomatic accessory navicular bone where three phase bone scan is equivocal.

This article is from PLoS ONE , volume 9 . Abstract Objectives: Left atrial appendage (LAA) dilatation and morphology may influence an individual's risk for intracardiac thrombi and ischemic stroke. LAA size and morphology can be evaluated using cardiac computed tomography (cCT). The present study evaluated the reproducibility of LAA volume and morphology assessments. Methods: A total of 149 patients (47 females; mean age 60.9±10.6 years) with suspected cardioembolic stroke/transient ischemic attack underwent cCT. Image quality was rated based on four categories. Ten patients were selected from each image quality category (N = 40) for volumetric reproducibility analysis by two individual readers. LAA and left atrium (LA) volume were measured in both two-chamber (2CV) and transversal view (TV) orientation. Intertechnique reproducibility was assessed between 2CV and TV (200 measurement pairs). LAA morphology (A = Cactus, B = ChickenWing, C = WindSock, D = CauliFlower), LAA opening height, number of LAA lobes, trabeculation, and orientation of the LAA tip was analysed in all study subjects by three individual readers (447 interobserver measurement pairs). The reproducibility of volume measurements was assessed by intra-class correlation (ICC) and the reproducibility of LAA morphology assessments by Cohen's kappa. Results: The intra-observer and interobserver reproducibility of LAA and LA volume measurements was excellent (ICCs>0.9). The LAA (ICC = 0.954) and LA (ICC = 0.945) volume measurements were comparable between 2CV and TV. Morphological classification (ĸ = 0.24) and assessments of LAA opening height (ĸ = 0.1), number of LAA lobes (ĸ = 0.16), trabeculation (ĸ = 0.15), and orientation of the LAA tip (ĸ = 0.37) was only slightly to fairly reproducible. Conclusions: LA and LAA volume measurements on cCT provide excellent reproducibility, whereas visual assessment of LAA morphological features is challenging and results in unsatisfactory agreement between readers.

Point-of-care ultrasonography (POCUS), a LUS tool widely used in emergency and critical care departments, is particularly practical as it can be used at the patient’s bedside, saving time and capacity. LUS and CT can both be used for diagnosis, assessment of disease severity, and evaluation of prognosis of COVID-19. In this systematic review, we aim to comprehensively identify the diagnostic agreement between LUS and CT in the diagnosis of COVID-19.

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This article is from Journal of Cardiovascular Ultrasound , volume 19 . Abstract Background: Three-dimensional (3D) echocardiography has been reported to be valuable for evaluating the geometry of cardiac chambers. We validated the accuracy of 3D transthoracic echocardiography for quantifying aortic root geometry in comparison with cardiac multi-detector computed tomography (MDCT). Methods: Twenty-three patients who underwent cardiac MDCT and showed normal left ventricular ejection fraction (> 55%), as assessed by 2-dimensional transthoracic echocardiography, were enrolled (12 male, mean 53 ± 9 years). We defined the aortic root volume as the volume from the aortic annulus to the sinotubular junction. The aortic root volume at end-diastole measured by both cardiac MDCT and 3D echocardiography was assessed. Results: The cross-sectional area of the aortic root was asymmetric. At the annulus level, the cross-sectional area showed asymmetric triangle. From the aortic annulus to the most dilated point of the sinus of Valsalva, the asymmetric triangular shape was maintained. From the most dilated point of the sinus of Valsalva to the sinotubular junction, the cross-sectional shape of the aortic root changed to oval. The average aortic root volumes measured by 3D echocardiography (ARV-3DE) were 13.6 ± 4.8 mL at end-diastole and 14.1 ± 5.3 mL at end-systole, respectively. The average aortic root volume measured by MDCT at end-diastole (ARV-CT) was 14.1 ± 5.7 mL. At end-diastole, the ARV-3DE correlated well with the ARV-CT (R2 = 0.926, difference = 0.5 ± 1.7 mL), and the two methods were in excellent agreement (the percent difference was 0%). Conclusion: Our results demonstrate both the feasibility and accuracy of 3D echocardiography for the clinical assessment of the geometry of the aortic root.

This article is from Journal of Cardiovascular Ultrasound , volume 19 . Abstract Background: Three-dimensional (3D) echocardiography has been reported to be valuable for evaluating the geometry of cardiac chambers. We validated the accuracy of 3D transthoracic echocardiography for quantifying aortic root geometry in comparison with cardiac multi-detector computed tomography (MDCT). Methods: Twenty-three patients who underwent cardiac MDCT and showed normal left ventricular ejection fraction (> 55%), as assessed by 2-dimensional transthoracic echocardiography, were enrolled (12 male, mean 53 ± 9 years). We defined the aortic root volume as the volume from the aortic annulus to the sinotubular junction. The aortic root volume at end-diastole measured by both cardiac MDCT and 3D echocardiography was assessed. Results: The cross-sectional area of the aortic root was asymmetric. At the annulus level, the cross-sectional area showed asymmetric triangle. From the aortic annulus to the most dilated point of the sinus of Valsalva, the asymmetric triangular shape was maintained. From the most dilated point of the sinus of Valsalva to the sinotubular junction, the cross-sectional shape of the aortic root changed to oval. The average aortic root volumes measured by 3D echocardiography (ARV-3DE) were 13.6 ± 4.8 mL at end-diastole and 14.1 ± 5.3 mL at end-systole, respectively. The average aortic root volume measured by MDCT at end-diastole (ARV-CT) was 14.1 ± 5.7 mL. At end-diastole, the ARV-3DE correlated well with the ARV-CT (R2 = 0.926, difference = 0.5 ± 1.7 mL), and the two methods were in excellent agreement (the percent difference was 0%). Conclusion: Our results demonstrate both the feasibility and accuracy of 3D echocardiography for the clinical assessment of the geometry of the aortic root.

Bibliografia na stronie 65. ; Streszczenie w języku polskim. ; artykuł w: Annales Universitatis Mariae Curie-Skłodowska. Sectio D, Medicina Vol. 58, nr 1, 12 (2003), strony 62-66

artykuł w: Annales Universitatis Mariae Curie-Skłodowska. Sectio D, Medicina. Vol. 58/2, 156 (2003), strony 394-401. ; Bibliografia na stronach 400-401.

This article is from Iranian Journal of Child Neurology , volume 6 . Abstract Objective: The advent of computed tomography (CT) scan revolutionized the diagnostic evaluation of neurologic patients. The aim of this study was to evaluate brain CT results of epileptic children. Materials & Methods: In a descriptive cross-sectional study, noncontrast brain CT scan of 150 consecutive 1-18 year old epileptic children whom were referred to pediatric neurology clinic of Shahid Sadoughi University of Medical Sciences, from May 2008 to October 2010 in Yazd-Iran, evaluated. Results: Sixty two girls and 88 boys with mean age of 6.6 ± 4.3 years were evaluated. In 38 (25.3 %) children, seizure onset age was under one year and 38 others had abnormal mental / developmental status. Fifty three children (35.3 %) and 97 (64.7%) had partial and generalized seizures, respectively. Partial seizures were more prevalent in children with seizure onset in < 1 year [41.5% (22/53) vs. 16.5% (16/97)] Result of CT was normal in 74 % (n=111). Among the patients with abnormal results, 18(46%) had brain atrophy, 10 (25.6%) structural CNS dysgenesia, six (15.4%) intracranial calcification, three (7.8%) hydrocephaly and two had (5.2%) brain tumor. Abnormal brain CT was more prevalent in patients with seizure onset in less than one year of age [60.5% (23 of 38) vs. 14.3% (16 of 112), p = 0.003], partial epilepsy [51% (27 of 53) vs. 12% (12/97)], and abnormal developmental status [ 81.5% (31 of 38) vs.7% (8 of 112]. Mean age of seizure onset in epileptic children with abnormal brain CT scan was less (M ± SD:1/17 ± 0.6 years versus 4.02±1.9 years). Conclusion: Brain CT scan might be considered in evaluation of epileptic children with partial seizures, seizure onset in less than one year of age or neurodevelopmental delay.

This article is from Indian Journal of Nuclear Medicine : IJNM : The Official Journal of the Society of Nuclear Medicine, India , volume 29 . Abstract None

Computed tomography imaging spectrometers ("CTISs") employing a single lens are provided. The CTISs may be either transmissive or reflective, and the single lens is either configured to transmit and receive uncollimated light (in transmissive systems), or is configured to reflect and receive uncollimated light (in reflective systems). An exemplary transmissive CTIS includes a focal plane array detector, a single lens configured to transmit and receive uncollimated light, a two-dimensional grating, and a field stop aperture. An exemplary reflective CTIS includes a focal plane array detector, a single mirror configured to reflect and receive uncollimated light, a two-dimensional grating, and a field stop aperture.

NASA has identified the need for advanced non-destructive evaluation (NDE) methods to characterize aging and durability in aircraft materials to improve the safety of the nation's airline fleet. 3D THz tomography can play a major role in detection and characterization of flaws and degradation in aircraft materials, including Kevlar-based composites and Kevlar and Zylon fabric covers for soft-shell fan containment where aging and durability issues are critical. A prototype computed tomography (CT) time-domain (TD) THz imaging system has been used to generate 3D images of several test objects including a TUFI tile (a thermal protection system tile used on the Space Shuttle and possibly the Orion or similar capsules). This TUFI tile had simulated impact damage that was located and the depth of damage determined. The CT motion control gan try was designed and constructed, and then integrated with a T-Ray 4000 control unit and motion controller to create a complete CT TD-THz imaging system prototype. A data collection software script was developed that takes multiple z-axis slices in sequence and saves the data for batch processing. The data collection software was integrated with the ability to batch process the slice data with the CT TD-THz image reconstruction software. The time required to take a single CT slice was decreased from six minutes to approximately one minute by replacing the 320 ps, 100-Hz waveform acquisition system with an 80 ps, 1,000-Hz waveform acquisition system. The TD-THZ computed tomography system was built from pre-existing commercial off-the-shelf subsystems. A CT motion control gantry was constructed from COTS components that can handle larger samples. The motion control gantry allows inspection of sample sizes of up to approximately one cubic foot (.0.03 cubic meters). The system reduced to practice a CT-TDTHz system incorporating a COTS 80- ps/l-kHz waveform scanner. The incorporation of this scanner in the system allows acquisition of 3D slice data with better signal-to-noise using a COTS scanner rather than the gchirped h scanner. The system also reduced to practice a prototype for commercial CT systems for insulating materials where safety concerns cannot accommodate x-ray. A software script was written to automate the COTS software to collect and process TD-THz CT data.

Computed tomography (CT) inspection was performed on test articles additively manufactured from metallic materials. Metallic AM and machined wrought alloy test articles with programmed flaws were inspected using a 2MeV linear accelerator based CT system. Performance of CT inspection on identically configured wrought and AM components and programmed flaws was assessed using standard image analysis techniques to determine the impact of additive manufacturing on inspectability of objects with complex geometries.

This article is from Dental Research Journal , volume 8 . Abstract Background:: Preoperative radiographic evaluation of impacted third molars is essential to determine the proximity to the mandibular canal to minimize the risk of nerve injury. Our study aim was to evaluate the relationship between the mandibular canal and impacted mandibular third molars using cone beam computed tomography (CBCT) and to compare findings therein with panoramic radiographic signs. Methods:: CBCT images were taken from 29 patients having 43 Class C impacted mandibular third molars whose panoramic radiographs showed a close relationship between the mandibular canal and mandibular third molars. We evaluated their tomographs to determine the course of the canal, its proximity to the root, any narrowing of the canal, the presence of root grooving or hooks and the proximity of the root to the cortex. A Chi-square test was used for data analysis. Results:: The lingual course of the canal was the most frequently detected course in all panoramic findings. Contact of the tooth with the canal was observed in all cases in which panoramic signs of deviation of the canal and darkening of the roots were found. The frequency of observing the narrowing of the canal in CBCT as compared to seeing the presence or the absence of canal narrowing in panoramic radiographs was significantly different (P=0.01). Conclusion:: CBCT provides more precise diagnostic information to determine the relationship of impacted third molars to the canal. Deviation of the canal and darkening of the roots in panoramic view can be highly valuable to predict the risk of nerve injury.

Urothelial cancer is the 4th most common malignant tumor after prostate (or breast), lung and colorectal cancer. Transitional cell carcinomas of the upper urinary tract (UTC) are less common than those of the bladder, but 60% are diagnosed as early as stage III. Risk factors include tobacco smoking and professional activities (employment in the paint and varnish, chemical, oil industries). In addition, the ureters are secondarily involved in the volumetric processes of the abdominal cavity and especially the small pelvis. All patients underwent a comprehensive X-ray examination: ES was initially performed in 64.8% (n = 92), ultrasound in 67.6% (n = 96). All patients then underwent CTU and/or MRU.

Background: Pulmonary embolism (PE) is an obstruction of the principal pulmonary artery, or one of its parts, by a material that has passed into the bloodstream from elsewhere in the body. 

Background: A computer-assisted bolus tracking system that initiates diagnostic scans prompted by contrast enhancement was recently developed. Using low-dose scans, this technology allows the scans to start, either manually or automatically, when the contrast enhancement rises to a predefined threshold (ROI).

In this paper certain type of biometric measurements has been used to identify the cone beam computed tomography (CBCT) radiograph of the subject in a fast and reliable way. Where the CBCT radiograph of a person is used as a data and stored in database for later use in a person’s recognition process. The aim of this research is to use various stages of the preprocessing operations of the CBCT radiograph to obtain the clearest possible image that will help us in the identification process more easily and precisely. The contourlet transformation was used for feature extraction of each particular CBCT image and the results were processed by a new hybrid particle swarm optimization (PSO) named "contourlet PSO" algorithm (CPSO), which is faster and produce more precise (due to apply contourlet algorithm) than traditional PSO. The proposed algorithm (CPSO) gave a detection ratio of 98% after its application on 100 CBCT radiographs.

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In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. (For more information: 12 Tables of Code ) Name of Standards Organization: Bureau of Indian Standards (BIS) Division Name: Medical Equipment and Hospital Planning Section Name: Hospital Planning (MHD 14) Designator of Legally Binding Document: IS 13450-2-44 Title of Legally Binding Document: Medical Electrical Equipment : Part 2 - Particular Requirements for the Safety, Section 44: X-Ray Equipment for Computed Tomography Number of Amendments: Equivalence: IEC 60601-2-44 Superceding: Superceded by: LEGALLY BINDING DOCUMENT Step Out From the Old to the New --Jawaharlal Nehru Invent a new India using knowledge. --Satyanarayan Gangaram Pitroda

The application of X-ray computed tomography (CT) for aircraft and aerospace structure and ancillary equipment has been investigated in the Advanced Development of X-Ray Computed Tomography Applications demonstration (CTAD) program sponsored by the NDE Branch of the Materials Directorate at the Air Force Wright Laboratory (WL). X-ray CT offers a new inspection capability for aircraft hardware that provides quantitative information on material density/constituents and dimensions. This capability has economic value as an engineering tool for improving the evaluation and control of materials and processes used in aircraft/aerospace structures. The CTAD effort has investigated a wide variety of application areas for CT. These include electronics, closed systems, castings, composites, and advanced materials and processes. Applications of CT in these areas include: configuration control, anomaly detection, dimensional measurements and material uniformity. By using the actual dimensional characteristics of features and anomalies in a component, and the material characteristics, such as density and elemental composition, that are derivable from the CT data, engineers can perform a variety of analyses to arrive at quantitative measurements that are of economical value to improving the overall product cycle from development to deployment. Until specifications requiring CT are implemented, CT will be employed primarily as a supplement to other NDE methodologies for engineering evaluations such as product development/ material characterization measurements, failure analysis and engineering problem solving, noninvasive micrography and geometry acquisition.

Purpose: In the National Lung Screening Trial (NLST), indeterminate pulmonary nodules were detected in 40% of high-risk individuals screened by low dose high-resolution computed tomography (HRCT). However, 96% of these nodules were benign, indicating that false positive findings represent a major challenge for the clinical adoption of CT-based lung cancer screening. While current clinical-radiological risk prediction models are very valuable, optimization of the clinicalmanagement strategies for larger ( 7 mm) screen-detected nodules is needed to avoid unnecessary diagnostic interventions including futile thoracotomies. In this project, we explore the utility of a novel radiomics-based approach for the classification of screen-detected indeterminate nodules. Material and methods: Independent quantitative variables assessing various radiologic nodule features such as sphericity, flatness, elongation, spiculation, lobulation and curvature were developed from the NLST dataset (using all 726 nodules 7 mm; benign, n=318 and malignant, n=408). Multivariate analysis was performed using least absolute shrinkage and selection operator (LASSO) method for variable selection and regularization in order to enhance the prediction accuracy and interpretability of the multivariate model. To increase the stability of the modeling, LASSO was run 1,000 times and the variables that were selected in at least 50% of the runs were included into the final multivariate model. The bootstrapping method was then applied for the internal validation and the optimism-corrected AUC was reported for the final model (model 1: radiologic model). Relevant clinical variables (patient age and smoking history in pack-years) were then added to the model in an attempt to improve its diagnostic test characteristics (model 2: clinical-radiologic model).

Введение. При исследовании композиционных материалов строительного назначения необходимо рассматривать механизмы формирования структуры и свойств современных бетонов в процессе набора прочности. В исследованиях современных композиционных материалов на основе цементного вяжущего отсутствуют сведения о развитии дефектов структуры и разрушении материала на начальных этапах набора прочности. Эти сведения можно получить с помощью рентгеновской компьютерной томографии — перспективного метода неразрушающего контроля состояния материала. Поэтому целью данной работы было изучение образования и распространения трещин в образцах мелкозернистого бетона с различным фракционным составом песка за счет естественных процессов усадки цемента, а также механики разрушения образцов модифицированного мелкозернистого бетона при приложении сжимающей нагрузки на ранних этапах набора прочности. Материалы и методы. В исследовании использовались мелкозернистые бетонные смеси трех составов с различной градацией песка. Образцы для томографии изготавливались путем помещения свежих смесей в полимерные цилиндрические емкости. Томографию образцов сразу после изготовления, а также через 8 и 51 сутки проводили на микрофокусном рентгеновском аппарате YXLON Cheetah. Модификацию состава с двухфракционным песком проводили путем механоактивации компонентов, изготавливали образцы-кубы 20×20×20 мм. Далее проводили компрессионные испытания на установке Instron через 3 и 7,5 часов, а затем — томографию разрушенных образцов. Результаты. Установлено, что разрушение контактных зон зависело от соотношения размеров фракций. При наличии в бетоне основной массы крупных зерен песка разрушение контактных зон было более выраженным и имело основной режим. При использовании мелкого или полифракционного песка контактные зоны разрушались локально и имели визуально меньшую площадь. На снимках разрушенного модифицированного образца, испытанного через 3 часа после изготовления, были видны четкие трещины и выбоины на кромках, что свидетельствовало об упругопластическом характере разрушения. Через 7,5 часов края образца при разрушении покрылись сеткой мелких трещин; Внутри образца также наблюдались многочисленные трещины и микротрещины, что свидетельствовало о хрупком разрушении. На основе полученных изображений деформированной структуры модифицированного бетона отчетливо просматривался механизм перехода от упругопластического разрушения материала к хрупкому. Обсуждение и заключение. Изученные зависимости влияния размера мелкого заполнителя на механизмы образования и распространения структурных дефектов вносят вклад в теорию процессов разрушения мелкозернистых бетонов. Полученные результаты доказывают перспективность использования рентгеновской компьютерной томографии как метода неразрушающего контроля внутренней структуры мелкозернистого бетона,в том числе на ранних этапах развития силы

Carbon fiber reinforced polymers (CFRPs) are well established as an important weight-reducing structural technology, particularly within the aerospace sector due to their high specific stiffness and strength. CFRPs are widely identified as being very fatigue resistant, but typically this advantage is not fully exploited in design. Understanding and predicting the durability of these materials is of great interest. The current work aimed to delineate the micro-mechanisms of fatigue damage in carbon fiber-epoxy laminated composites using in situ and ex situ synchrotron radiation computed tomography (SRCT). Several novel observations have been obtained for the micro-mechanisms of fatigue crack growth. Broadly similar micro-mechanisms of damage initiation have been identified in fatigue and quasi-static loading in a particle-toughened carbon fiber-epoxy composite system. Results showed that damage propagation is closely related to the local microstructure. Toughened systems exhibit different damage behavior in resin-rich regions and fiber-packed zones, which appears to exaggerate non-uniform crack growth. Zones of retarded crack growth correspond to resin rich regions, which contain bridging ligaments. There is evidence that the load cycling contributes to progressive failure of bridging ligaments in the crack wake, especially in the toughened particle system. The un-toughened system showed more uniform damage propagation across the crack front, due to the more uniform microstructure and showed a higher number of fiber breaks within the 0 plies with respect to the toughened systems, particularly within regions close to the 0 ply splits. It seems likely that a key mechanism of fatigue in the toughened-particle system on intralaminar loading is the degradation of bridging ligaments introduced by particles in the fatigue crack wake rather than due to processes at, or ahead of the crack tip.

Head trauma can lead to severe brain injuries, and computed tomography (CT) is an important tool for diagnosing and evaluating these injuries. CT is able to identify hemorrhages, edema, fractures and other abnormalities in the structure of the brain, allowing it to be possible to assess the severity of the trauma and plan the appropriate treatment. CT is usually performed quickly after an injury as it provides crucial information for immediate treatment decisions, its use has helped to significantly improve outcomes for patients with traumatic injuries. It is considered the exam of choice to assess the severity of head trauma and to monitor the progression of the injury over time, however, when compared to radiography, CT exposes patients to a much higher dose of radiation, we aim to reduce this dose radiation without losing quality and detection rate.

This article is from PLoS ONE , volume 9 . Abstract Objective: To quantitatively assess the imaging characteristics of sellar lesion in dual-energy computed tomography (CT) imaging for differentiation of sellar meningiomas and pituitary adenomas during the arterial phase (AP) and venous phase (VP). Materials and Methods: 51 patients with sellar/parasellar tumors (33 macroadenomas and 18 meningiomas) were examined with CT spectral imaging during the AP and the VP. Iodine concentrations were derived from iodine-based material-decomposition CT images and normalized to the iodine concentration in the aorta. The difference in Normalized iodine concentrations (NICs), HU curve slope (λHU), and mean CT values of lesions between the AP and VP were calculated. The two-sample t test was performed to compare quantitative parameters between sellar meningiomas and pituitary adenomas. Results: NICs, λHU, and mean CT values in patients with sellar meningiomas differed significantly from those in patients with pituitary adenomas: Mean NICs were 43.52 mg/mL±1.35 versus 9.23 mg/mL ±2.44, respectively, during the AP and 52.13 mg/mL ±1.04 versus 24.37 mg/mL ±2.23 respectively, during the VP. λHU were −3.03±3.42 versus −0.53±0.23, respectively, during the AP and −2.96±0.41 versus −0.47±0.25, respectively, during the VP. Mean CT values were 193.63±2.08 versus 63.98±2.85, respectively, during the AP and 203.98±0.18 versus 77.66±0.91, respectively, during the VP. The combination of NIC and Mean CT value during VP had highest sensitivity (90.9%) and specificity (100%) among all phases. Conclusion: Quantitative dual-energy CT imaging has promising potential for diagnostic differentiation of sellar meningiomas and pituitary adenomas.

ABSTRACT Objectives: There is not enough data on the effect of COVID-19 on spleen volume in patients with COVID-19. Our aim was to compare the spleen volume of the COVID-19 patients with the control group. Material and Method: 214 Patients (121 men, 93 women) who have a diagnosis of COVID-19 who have thorax CT were included in the study. In the patient group, there was evidence of viral pneumonia on thoracic CT or PCR was positive, all of them were patients who received treatment for Covid. The control group consisted of 185 patients (106 men, 79 women). Interobserver agreement was calculated. Analysis of the receiver operating characteristic (ROC) curve was used to identify a spleen volume cutoff value at which the accuracy for COVID-19 diagnosis was maximised. Results: The mean spleen volume of the patient group was found to be 260 (range, 96.3-565, SD: 82.5) which was statistically significantly higher than the control group which was 220 (range, 125.9-331.9, SD: 34.5) (p

This article is from JSLS : Journal of the Society of Laparoendoscopic Surgeons , volume 16 . Abstract The authors found that exploratory laparoscopy during splenectomy was more accurate than preoperative imaging with CT scan for detection of accessory spleens.

This article is from Clinical Medicine. Oncology , volume 2 . Abstract The purpose of this study is to evaluate the 3-dimensional target localization accuracy of cone-beam computed tomography (CBCT) using an on-board imager (OBI). An anthropomorphic pelvis phantom was used to simulate a range of offsets in the three translational directions and rotations around each of the three axes. After a translational or rotational offset was applied, a CBCT scan of the phantom was followed by image registration to detect the offsets in six degrees. The detected offsets were compared to the offset actually applied to give the detection error of the phantom position. Afterwards, the phantom was positioned by automatically moving the couch based on the detected offsets. A second CBCT scan followed by image registration was performed to give the residual error of the phantom positioning. On the average the detection errors and their standard deviations along the lateral, longitudinal and vertical axis are 0.3 ± 0.1, 0.3 ± 0.1 and 0.4 ± 0.1 mm respectively with respect to translational shifts ranging from 0 to 10 mm. The corresponding residual errors after positioning are 0.3 ± 0.1, 0.5 ± 0.1 and 0.3 ± 0.1 mm. For simulated rotational shifts ranging from 0 to 5 degrees, the average detection error and their standard deviation around lateral, longitudinal, and vertical axes are 0.1 ± 0.0, 0.2 ± 0.0, and 0.2 ± 0.0 degrees respectively. The residual errors after positioning are 0.4 ± 0.1, 0.6 ± 0.1, and 0.3 ± 0.1 mm along the lateral, longitudinal and vertical directions. These results indicate that target localization based on CBCT is capable of achieving sub-millimeter accuracy.

This article is from Clinical Medicine. Oncology , volume 2 . Abstract The purpose of this study is to evaluate the 3-dimensional target localization accuracy of cone-beam computed tomography (CBCT) using an on-board imager (OBI). An anthropomorphic pelvis phantom was used to simulate a range of offsets in the three translational directions and rotations around each of the three axes. After a translational or rotational offset was applied, a CBCT scan of the phantom was followed by image registration to detect the offsets in six degrees. The detected offsets were compared to the offset actually applied to give the detection error of the phantom position. Afterwards, the phantom was positioned by automatically moving the couch based on the detected offsets. A second CBCT scan followed by image registration was performed to give the residual error of the phantom positioning. On the average the detection errors and their standard deviations along the lateral, longitudinal and vertical axis are 0.3 ± 0.1, 0.3 ± 0.1 and 0.4 ± 0.1 mm respectively with respect to translational shifts ranging from 0 to 10 mm. The corresponding residual errors after positioning are 0.3 ± 0.1, 0.5 ± 0.1 and 0.3 ± 0.1 mm. For simulated rotational shifts ranging from 0 to 5 degrees, the average detection error and their standard deviation around lateral, longitudinal, and vertical axes are 0.1 ± 0.0, 0.2 ± 0.0, and 0.2 ± 0.0 degrees respectively. The residual errors after positioning are 0.4 ± 0.1, 0.6 ± 0.1, and 0.3 ± 0.1 mm along the lateral, longitudinal and vertical directions. These results indicate that target localization based on CBCT is capable of achieving sub-millimeter accuracy.

The review was made to answer the following focused question in Population, Exposure and Outcome (PEO) format : (P) Among dentulous or partially edentulous patients subjected to (E) CBCT evaluation, what relationship is there between odontogenic lesions and the appearance of (O) anatomical alterations of the sinus membrane, maxillary sinusitis and mucosal retention cysts.

This scoping review aims to explore current knowledge on terminology, appearance, and measurements used to assess maxillary sinusitis of odontogenic origin on cone beam computed tomography images.

This scoping review aims to explore current knowledge on terminology, appearance, and measurements used to assess maxillary sinusitis of odontogenic origin on cone beam computed tomography images.

This scoping review aims to explore current knowledge on terminology, appearance, and measurements used to assess maxillary sinusitis of odontogenic origin on cone beam computed tomography images.

artykuł w: Annales Universitatis Mariae Curie-Skłodowska. Sectio D, Medicina. Vol. 62, N1, 65 (2007), strony 358-366. ; Bibliografia na stronie 365.

Artykuł w: Annales Universitatis Mariae Curie-Skłodowska. Sectio D, Medicina. Vol. 61, N2, nr 188 (2006), strony 1039-1045

Recent years have seen growing interest in exploiting dual- and multi-energy measurements in computed tomography (CT) in order to characterize material properties as well as object shape. Material characterization is performed by decomposing the scene into constitutive basis functions, such as Compton scatter and photoelectric absorption functions. While well motivated physically, the joint recovery of the spatial distribution of photoelectric and Compton properties is severely complicated by the fact that the data are several orders of magnitude more sensitive to Compton scatter coefficients than to photoelectric absorption, so small errors in Compton estimates can create large artifacts in the photoelectric estimate. To address these issues, we propose a model-based iterative approach which uses patch-based regularization terms to stabilize inversion of photoelectric coefficients, and solve the resulting problem though use of computationally attractive Alternating Direction Method of Multipliers (ADMM) solution techniques. Using simulations and experimental data acquired on a commercial scanner, we demonstrate that the proposed processing can lead to more stable material property estimates which should aid materials characterization in future dual- and multi-energy CT systems.

Division of the liver from figured computed tomography (CT) images is fundamental for the greater part of the PC supported clinical applications, for instance, the arranging period of a liver transfer, liver volume assessment, and radiotherapy. In this paper, a programmed liver location model from clinical CT filters utilizing profound semantic division convolutional neural organization will be introduced, this model will actually want to subsequently isolate the liv er utilizing CT images. The proposed model presents simultaneously the liver ID and the probabilistic division utilizing a profound convolutional neural organization. The proposed approach was endorsed on 10 CT volumes taken from open data sets 3Dircadb1. The proposed model is totally programmed with no requirement for client mediation. Quantitative results show that proposed model is reliable and exact for hepatic volume assessment in a clinical course of action with testing exactness 98.8%.

Lung cancer (LC) is one of the most prevalent causes of cancer-related death worldwide. World Health Organization (WHO) classifies LC into two broad histological subtypes: non-small cell lung cancer (NSCLC) which is the cause of about 85% of cases and small cell lung cancer (SCLC) which makes up the remaining 15%. Several issues can influence LC detection including poor image quality, insufficient training data, low-quality image characteristics, and poor tumor localization. To overcome these challenges a novel TRI-level LC classification via deep learning-based GoogleNet with computed tomography (CT) images (TRI-LCNet) approach has been proposed for early-stage LC detection using CT images. Initially, the LC input images CT are collected from openly accessible datasets. The lung CT images have been preprocessed using a Gaussian star filter (GaSF) to decrease noise, followed by feature extraction using GoogleNet. The extracted LC features are then given into a support vector machine (SVM) which is utilized as a classification tool to distinguish between different classes of LC cases. The TRI-LCNet approach performance was assessed by several metrics: specificity, accuracy, F1 score, and recall. The outcomes show that the suggested method obtains a higher accuracy range of 96.93% for the early identification of LC.

Aim: The study aimed to compare the efficacy of endoscopic ultrasound (EUS) and computed tomography (CT) in detecting primary tumor and evaluating preoperative vascular and peripheral invasion in histopathologically proven malignant ampullar tumors. Material and Methods: Fifty-two patients who underwent surgery or endoscopic ampullectomy for the primary ampullary tumors between 2014 and 2016 were evaluated. The demographic data and EUS, CT, pathology results of all patients were recorded. The efficacy of EUS and CT in detecting tumor, peripheral tissue invasion, and vascular tissue invasion was evaluated and compared with pathology results. Results: Forty-nine patients had the Whipple procedure and 3 patients underwent endoscopic ampullectomy. In pathology results, all patients had adenocarcinoma histology, and the mean tumor diameter was 20.12 mm. The rate of peripheral tissue invasion and vascular invasion was 86.5%, 5.8% respectively. Ampullary mass was detected in 41 (78.8%) patients by EUS, in 35 (67.3%) by CT (p=0.002). Three patients had a vascular invasion in pathology. The sensitivity and specificity of EUS in detecting vascular invasion were 66% and 100%, respectively. CT failed to demonstrate vascular invasion in these 3 patients. Discussion: The results showed that EUS was superior to CT in detecting a mass, peripheral tissue invasion, and vascular invasion. Although EUS is superior to CT, CT plays an important role in the evaluation of distant metastases, and therefore CT and EUS are two important complementary radiological tests in the evaluation of these patients.

Aim: To present 27 cases with non-traumatic extraspinal sciatica by means of computerized tomography (CT) and magnetic resonance imaging (MRI) and to investigate the frequency and etiological distribution of non-traumatic extraspinal sciatica.  Material and Method: CT and MRI surveys of patients with sciatica complaints were evaluated retrospectively. Patients with pathology which might have caused sciatica were included in the study. Final diagnostic clinical findings were concluded with CT-MRI images and histopathological examination. Intraspinal (discogenic, facet arthropathy, etc.) and traumatic sciatica cases were excluded from the study.  Results: Pathology affecting the sciatic nerve was detected in 27 patients. 14 of the patients were female, 13 were male; average age was 53 (18 – 91). The most frequent pathology was sacroiliitis (n = 9). It was detected that 7 cases had malignant tumor, 5 cases had benign tumor, 3 cases had piriformis syndrome, 1 case had arteriovenous malformation, 1 case had gluteal abscess, and 1 case had obturator artery aneurysm.  Discussion: Sacroiliitis is the most frequent cause of extraspinal non-traumatic sciatica. In accordance with the clinical findings, primarily the sacroiliac joint should be assessed in patients without a spinal pathology. However, other rare extraspinal pathologies should also be kept in mind. 

Computed Tomography

Computed Tomography