83,611 results match your criteria tomography scans

Robotic-assisted total knee arthroplasty improves the outlier of rotational alignment of the tibial prosthesis using 3DCT measurements.

Knee 2021 Jun 9;31:64-76. Epub 2021 Jun 9.

Department of Orthopedic Surgery, Toho University School of Medicine, Japan. Electronic address:

Background: The aim of the present study was to compare the accuracy of prosthetic alignment with three-dimensional computed tomography (3DCT) measurements following total knee arthroplasty (TKA) performed using a robotic-assisted surgical technique versus a conventional TKA.

Methods: 41 TKAs were performed with a handheld robotic-assisted surgical procedure (Robot group) between 2019 and 2020. Another 41 patients underwent TKA with a conventional manual surgical procedure (Manual group) using the same prosthesis. Read More

View Article and Full-Text PDF

Changes in Scapular Bone Density Vary by Region and are Associated with Age and Sex.

J Shoulder Elbow Surg 2021 Jun 9. Epub 2021 Jun 9.

Department of Orthopaedics and Sports Medicine, University of Washington, Seattle WA, USA.

Background: Decreases in bone density of the scapula due to age and disease can make orthopedic procedures such as arthroplasty and fracture fixation challenging. There is limited information in the literature regarding the effect of age and sex on the patterns of these density changes across the bone. Characterizing these changes could assist the surgeon in planning optimal instrumentation placement. Read More

View Article and Full-Text PDF

COVID-19 Diagnosis on CT Scan Images Using a Generative Adversarial Network and Concatenated Feature Pyramid Network with an Attention Mechanism.

Med Phys 2021 Jun 12. Epub 2021 Jun 12.

School of Information Science and Engineering, Yunnan University, Kunming, Yunnan, 650500, China.

Objective: Coronavirus disease 2019 (COVID-19) has caused hundreds of thousands of infections and deaths. Efficient diagnostic methods could help curb its global spread. The purpose of this study was to develop and evaluate a method for accurately diagnosing COVID-19 based on computed tomography (CT) scans in real time. Read More

View Article and Full-Text PDF

Linear elastic and hyperelastic studies of equine hoof mechanical response at different hydration levels.

J Mech Behav Biomed Mater 2021 Jun 5;121:104622. Epub 2021 Jun 5.

Department of Veterinary Biosciences, The University of Melbourne, Melbourne, VIC, Australia.

Most simulation studies on equine hoof biomechanics employed linear elastic (LE) material models. However, the equine hoof wall's stress-strain relationship is nonlinear and varies with hydration level. Therefore, it is essential to investigate the accuracy of the LE model compared to more advanced material models, such as hyperelastic (HE) or viscoelastic models. Read More

View Article and Full-Text PDF

Shared Features in Retinal Disorders With Involvement of Retinal Pigment Epithelium.

Invest Ophthalmol Vis Sci 2021 Jun;62(7):15

Department of Ophthalmology, Harkness Eye Institute, Columbia University, New York, New York, United States.

When using spectral domain optical coherence tomography (SD-OCT) to inform the status of outer retina, we have noted discrete hyperreflective lesions extending through photoreceptor-attributable bands that have a similar presentation in multiple retinal diseases. These lesions present as either corrugated thickenings of interdigitation zone and ellipsoid zone bands or in later stages as rectangular or pyramidal shaped foci that extend radially through photoreceptor cell-attributable bands. In ABCA4-related and peripherin-2/RDS-disease (PRPH2/RDS), monogenic forms of retinopathy caused by mutations in proteins expressed in photoreceptor cells, these punctate lesions colocalize with fundus flecks in en face images. Read More

View Article and Full-Text PDF

Clinical and Radiographic Evaluation of Modified Transalveolar Two-Step Osteotome-Mediated Localized Maxillary Sinus Elevation: A Retrospective Computed Tomography Study with a 3-Year Follow-up.

Int J Oral Maxillofac Implants 2021 May-Jun;36(3):553-560

Purpose: This study aimed to report a practicable and noninvasive two-stage technique for sinus elevation and delayed implant insertion in the augmented site with residual bone height down to 3 mm or even lower.

Materials And Methods: The surgical technique employed a two-stage process for rehabilitation of posterior maxillary single-tooth edentulous areas, involving, in the first step, transcrestal maxillary sinus floor augmentation with a collagen sponge to fill the intrabony cavity resulting from the detachment of the sinus membrane; the second step consisted of another indirect sinus floor elevation using magnetoelectric surgery with immediate implant placement and no grafting material. Changes in bone height were evaluated by a comparison of the computed tomography scans acquired before treatment and after surgery (at 3 months and 5 years of the survey). Read More

View Article and Full-Text PDF

Prediction of Type II Diabetes Onset with Computed Tomography and Electronic Medical Records.

Multimodal Learn Clin Decis Support Clin Image Based Proc (2020) 2020 Oct 1;12445:13-23. Epub 2020 Oct 1.

Vanderbilt University, , Nashville, USA.

Type II diabetes mellitus (T2DM) is a significant public health concern with multiple known risk factors (, body mass index (BMI), body fat distribution, glucose levels). Improved prediction or prognosis would enable earlier intervention before possibly irreversible damage has occurred. Meanwhile, abdominal computed tomography (CT) is a relatively common imaging technique. Read More

View Article and Full-Text PDF
October 2020

Abdominal Aortic Aneurysm Segmentation Using Convolutional Neural Networks Trained with Images Generated with a Synthetic Shape Model.

Mach Learn Med Eng Cardiovasc Health Intravasc Imaging Comput Assist Stenting (2019) 2019 12;11794:167-174. Epub 2019 Oct 12.

Applied Chest Imaging Laboratory, Brigham and Women's Hospital, Harvard medical school, Boston, USA.

An abdominal aortic aneurysm (AAA) is a ballooning of the abdominal aorta, that if not treated tends to grow and rupture. Computed Tomography Angiography (CTA) is the main imaging modality for the management of AAAs, and segmenting them is essential for AAA rupture risk and disease progression assessment. Previous works have shown that Convolutional Neural Networks (CNNs) can accurately segment AAAs, but have the limitation of requiring large amounts of annotated data to train the networks. Read More

View Article and Full-Text PDF
October 2019

COVID-FACT: A Fully-Automated Capsule Network-Based Framework for Identification of COVID-19 Cases from Chest CT Scans.

Front Artif Intell 2021 25;4:598932. Epub 2021 May 25.

Concordia Institute for Information Systems Engineering (CIISE), Concordia University, Montreal, QC, Canada.

The newly discovered Coronavirus Disease 2019 (COVID-19) has been globally spreading and causing hundreds of thousands of deaths around the world as of its first emergence in late 2019. The rapid outbreak of this disease has overwhelmed health care infrastructures and arises the need to allocate medical equipment and resources more efficiently. The early diagnosis of this disease will lead to the rapid separation of COVID-19 and non-COVID cases, which will be helpful for health care authorities to optimize resource allocation plans and early prevention of the disease. Read More

View Article and Full-Text PDF

Consolidated lung on contrast-enhanced chest CT: the use of spectral-detector computed tomography parameters in differentiating atelectasis and pneumonia.

Heliyon 2021 May 26;7(5):e07066. Epub 2021 May 26.

Diagnostic and Interventional Radiology (DiR), Heidelberg University Hospital, Im Neuenheimer Feld 420, 69120 Heidelberg, Germany.

Objectives: To investigate the value of spectral-detector computed tomography (SDCT) parameters for the quantitative differentiation between atelectasis and pneumonia on contrast-enhanced chest CT.

Material And Methods: Sixty-three patients, 22 clinically diagnosed with pneumonia and 41 with atelectasis, underwent contrast-enhanced SDCT scans during the venous phase. CT numbers (Hounsfield Units [HU]) were measured on conventional reconstructions (CON) and the iodine concentration (C, [mg/ml]), and effective atomic number (Z) on spectral reconstructions, using region-of-interest (ROI) analysis. Read More

View Article and Full-Text PDF

Cardiac 18F-FDG Positron Emission Tomography: An Accurate Tool to Monitor Metabolic and Functional Alterations in Murine Myocardial Infarction.

Front Cardiovasc Med 2021 25;8:656742. Epub 2021 May 25.

Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany.

Cardiac monitoring after murine myocardial infarction, using serial non-invasive cardiac 18F-FDG positron emissions tomography (PET) represents a suitable and accurate tool for studies. Cardiac PET imaging enables tracking metabolic alterations, heart function parameters and provides correlations of the infarct size to histology. ECG-gated 18F-FDG PET scans using a dedicated small-animal PET scanner were performed in mice at baseline, 3, 14, and 30 days after myocardial infarct (MI) by permanent ligation of the left anterior descending (LAD) artery. Read More

View Article and Full-Text PDF

Clinical Impact of Reporting Coronary Artery Calcium Scores of Non-Gated Chest Computed Tomography on Statin Management.

Cureus 2021 May 5;13(5):e14856. Epub 2021 May 5.

Radiology, Brookwood Baptist Medical Center, Birmingham, USA.

Introduction Coronary artery calcium (CAC) scoring is used as a screening tool for patients with intermediate 10-year arteriosclerotic cardiovascular disease (ASCVD) risk. Results obtained on non-contrast non-gated chest CT (ngCCT) correlate well to those obtained on gated CTs. This paper aims to determine how the routine reporting of CAC scores on ngCCT scans with ASCVD risk of less than 12. Read More

View Article and Full-Text PDF

Changes of Neuroretinal Rim and Retinal Nerve Fiber Layer Thickness Assessed by Optical Coherence Tomography After Filtration Surgery in Glaucomatous Eyes.

Clin Ophthalmol 2021 3;15:2335-2344. Epub 2021 Jun 3.

Ludwig-Maximilians University, Eye Clinic, Campus Innenstadt, Munich, D-80336, Germany.

Purpose: Lowering the intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG) with filtration surgery can induce morphological changes to the bulbus and structures of the retina. In this study, we have evaluated changes of Bruch's membrane-based parameters and retinal nerve fiber layer (RNFL) derived by spectral-domain optical coherence tomography (SD-OCT) in eyes that have undergone glaucoma filtration surgery.

Patients And Methods: SD-OCT imaging of the optic nerve head (ONH) and of the RNFL was performed in 54 eyes of 54 patients with medically uncontrolled POAG before and after IOP-lowering surgery (trabeculectomy or deep sclerectomy). Read More

View Article and Full-Text PDF

Peripapillary Halo in Inflammatory Papillitis of Birdshot Chorioretinopathy.

Clin Ophthalmol 2021 3;15:2327-2333. Epub 2021 Jun 3.

Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.

Purpose: Peripapillary halos (PPH) are peripapillary changes observed surrounding the optic nerve head in normal eyes and eyes with different disorders. Recognizing the microstructure and mechanism of development of these halos will help clinicians understand the different associated retinal and optic nerve head pathologies. We describe the in vivo histological characteristics of PPH in birdshot chorioretinopathy (BSCR). Read More

View Article and Full-Text PDF

Examining Whether AOSLO-Based Foveal Cone Metrics in Achromatopsia and Albinism Are Representative of Foveal Cone Structure.

Transl Vis Sci Technol 2021 May;10(6):22

Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.

Purpose: Adaptive optics scanning light ophthalmoscopy (AOSLO) imaging in patients with achromatopsia (ACHM) and albinism is not always successful. Here, we tested whether optical coherence tomography (OCT) measures of foveal structure differed between patients for whom AOSLO images were either quantifiable or unquantifiable.

Methods: The study included 166 subjects (84 with ACHM; 82 with albinism) with previously acquired OCT scans, AOSLO images, and best-corrected visual acuity (BCVA, if available). Read More

View Article and Full-Text PDF

Validating Ellipsoid Zone Area Measurement With Multimodal Imaging in Choroideremia.

Transl Vis Sci Technol 2021 May;10(6):17

Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada.

Purpose: To assess en face ellipsoid zone (EZ) maps of remaining retinal structure as outcome measures for the future clinical research in patients with choroideremia.

Methods: Twenty eyes from 12 patients with a confirmed genetic diagnosis of choroideremia were included retrospectively from a single site. From spectral domain-optical coherence tomography volume scans, slabs including the EZ were manually segmented to create the en face EZ maps. Read More

View Article and Full-Text PDF

Longitudinal Evaluation of Hyper-Reflective Foci in the Retina Following Subretinal Delivery of Adeno-Associated Virus in Non-Human Primates.

Transl Vis Sci Technol 2021 May;10(6):15

University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany.

Purpose: The purpose of this study was to evaluate whether clinical grade recombinant adeno-associated virus serotype 8 (rAAV8) leads to increased appearance of hyper-reflective foci (HRF) in the retina of non-human primates (NHPs) following subretinal gene therapy injection.

Methods: Different doses of rAAV8 vector (rAAV8. human phosphodiesterase 6A subunit (hPDE6A) at low dose: 1 × 1011 vector genomes (vg), medium dose: 5 × 1011 vg, or high dose: 1 × 1012 vg) were injected subretinally into the left eyes of NHPs in a formal toxicology study in preparation of a clinical trial. Read More

View Article and Full-Text PDF

Anterior Chamber Measurements in Healthy Children: A Cross-Sectional Study Using Optical Coherence Tomography.

Transl Vis Sci Technol 2021 May;10(6):13

University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK.

Purpose: To establish anterior chamber measurements in children and investigate the influence of demographic factors on anterior chamber development.

Methods: Handheld optical coherence tomography was used to scan the anterior chamber of participants' eyes, without sedation. ImageJ was used to generate quantitative anterior chamber measurements, including central corneal thickness (CCT), anterior chamber width, trabecular meshwork length (TML), Schwalbe's line-angle opening distance (SL-AOD), and trabecular iris surface area (SL-TISA). Read More

View Article and Full-Text PDF

Focal Loss Analysis of Nerve Fiber Layer Reflectance for Glaucoma Diagnosis.

Transl Vis Sci Technol 2021 May;10(6)

Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA.

Purpose: To evaluate nerve fiber layer (NFL) reflectance for glaucoma diagnosis.

Methods: Participants were imaged with 4.5 × 4. Read More

View Article and Full-Text PDF

MAGIC: Manifold and Graph Integrative Convolutional Network for Low-Dose CT Reconstruction.

IEEE Trans Med Imaging 2021 Jun 10;PP. Epub 2021 Jun 10.

Low-dose computed tomography (LDCT) scans, which can effectively alleviate the radiation problem, will degrade the imaging quality. In this paper, we propose a novel LDCT reconstruction network that unrolls the iterative scheme and performs in both image and manifold spaces. Because patch manifolds of medical images have low-dimensional structures, we can build graphs from the manifolds. Read More

View Article and Full-Text PDF

Complications of cholecystitis: a comprehensive contemporary imaging review.

Emerg Radiol 2021 Jun 10. Epub 2021 Jun 10.

Department of Radiology, Emory University Hospital, Atlanta, GA, USA.

Acute cholecystitis is a common cause of right upper quadrant pain in patients presenting to the emergency department. Ultrasound, computed tomography, HIDA scans, and magnetic resonance imaging are increasingly utilized to evaluate suspected cases. The prognosis of acute cholecystitis is usually excellent with timely diagnosis and management. Read More

View Article and Full-Text PDF

"Benefits of the pedicled osteoplastic flap as a surgical approach of mastoidectomy in cochlear implant surgery".

Eur Arch Otorhinolaryngol 2021 Jun 10. Epub 2021 Jun 10.

Otorhinolaryngology Department, PhD, National Institute of Rehabilitation, Mexico City, Mexico.

Objective: To evaluate the esthetic and functional results of an osteoplastic flap for mastoid cavity closure in cochlear implant surgery.

Study Design: Double-blind, prospective, randomized clinical trial.

Setting: tertiary referral center. Read More

View Article and Full-Text PDF

Estimated Utility of the Short-term Assessment of Glaucoma Progression Model in Clinical Practice.

JAMA Ophthalmol 2021 Jun 10. Epub 2021 Jun 10.

Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, La Jolla.

Importance: Clinical trials of glaucoma therapies focused on protecting the optic nerve have required large sample sizes and lengthy follow-up to detect clinically relevant change due to its slow rate of progression. Whether shorter trials may be possible with more frequent testing and use of rate of change as the end point warrants further investigation.

Objective: To describe the design for the Short-term Assessment of Glaucoma Progression (STAGE) model and provide guidance on sample size and power calculations for shorter clinical trials. Read More

View Article and Full-Text PDF

Optical coherence tomography quantifying photo aging: skin microvasculature depth, epidermal thickness and UV exposure.

Arch Dermatol Res 2021 Jun 10. Epub 2021 Jun 10.

Department of Dermatology, Health Sciences Faculty, Zealand University Hospital, University of Copenhagen, Sygehusvej 10, 4000, Roskilde, Denmark.

Introduction: Photo aging predominantly occurs in the face, neck and hands due to UVA and UVB irradiation. It is associated with skin cancer and histological studies indicate thinning of the epidermis and elastosis occurs. Dynamic Optical coherence tomography (D-OCT) is a non-invasive imaging tool able to visualize the epidermis and upper dermis and its blood vessels as well as to evaluate epidermal thickness (ET) and blood flow. Read More

View Article and Full-Text PDF

Body Composition Parameters May Be Prognostic Factors in Upper Urinary Tract Urothelial Carcinoma Treated by Radical Nephroureterectomy.

Front Oncol 2021 24;11:679158. Epub 2021 May 24.

West China Hospital, Sichuan University, Chengdu, China.

Objective: This study assessed the association between body composition and prognosis of patients with upper urinary tract urothelial carcinoma (UTUC) patients treated by radical nephroureterectomy.

Methods: We retrospectively collected baseline data on age, sex, body mass index (BMI), hypertension, diabetes, and tumor-related factors. Computed tomography (CT) scans were performed to measure body composition parameters such as muscle attenuation (MA), total abdominal muscle area (TAMA), visceral fat area (VFA), intermuscular fat area (IMF), and lateral/posterior perirenal fat thickness (L/P PNF), visceral fat density (VD), and subcutaneous fat density (SD). Read More

View Article and Full-Text PDF

Weight-bearing cone-beam computed tomography in the foot and ankle specialty: where we are and where we are going - an update.

Radiol Bras 2021 May-Jun;54(3):177-184

Department of Orthopedics and Rehabilitation, Iowa City, Iowa, USA.

Cone-beam computed tomography (CBCT) has been applied in dentistry and medicine for nearly two decades. Its application in the foot and ankle specialty has grown exponentially in recent years. Weight-bearing CBCT allows clinicians to obtain weight-bearing images that can be viewed in all three planes and to construct three-dimensional models, similar to those constructed from traditional CT scans, as well as exposing patients to less radiation than do traditional CT scans. Read More

View Article and Full-Text PDF

Long-term bone mineral density changes and fractures in lung transplant recipients with cystic fibrosis.

J Cyst Fibros 2021 May 21;20(3):525-532. Epub 2020 Oct 21.

Department of Nutrition, Faculty of Medicine, Université de Montreal, 2405 Cote Sainte-Catherine Rd, Montreal, Quebec H3T 1A8, Canada; Research Centre, CHU Sainte-Justine, 3175 Cote Sainte-Catherine Rd, Montreal, Quebec H3T 1C5, Canada. Electronic address:

Background: Little is known about long-term bone mineral density (BMD) changes and fractures in lung transplant recipients with cystic fibrosis (CF). We examined femur and lumbar spine (LS) BMD changes in men and women with CF up to 10 years post-transplant and documented post-transplant fracture prevalence.

Methods: Retrospective study of individuals who had undergone a lung transplant (2000-2015) and had a pre-transplant and at least one BMD measurement after transplant. Read More

View Article and Full-Text PDF

Efficient high cone-angle artifact reduction in circular cone-beam CT using deep learning with geometry-aware dimension reduction.

Phys Med Biol 2021 Jun 9. Epub 2021 Jun 9.

Centrum Wiskunde en Informatica, Amsterdam, Noord-Holland, NETHERLANDS.

High cone-angle artifacts (HCAAs) appear frequently in circular cone-beam computed tomography (CBCT) images and can heavily affect diagnosis and treatment planning. To reduce HCAAs in CBCT scans, we propose a novel deep learning approach that reduces the three dimensional (3D) nature of HCAAs to two-dimensional (2D) problems in an efficient way. Specifically, we exploit the relationship between HCAAs and the rotational scanning geometry by training a convolutional neural network (CNN) using image slices that were radially sampled from CBCT scans. Read More

View Article and Full-Text PDF

Delivering computationally-intensive digital patient applications to the clinic: An exemplar solution to predict femoral bone strength from CT data.

Comput Methods Programs Biomed 2021 May 25;208:106200. Epub 2021 May 25.

INSIGNEO Institute for in silico Medicine, The University of Sheffield, UK; Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, UK.

Background And Objective: Whilst fragility hip fractures commonly affect elderly people, often causing permanent disability or death, they are rarely addressed in advance through preventive techniques. Quantification of bone strength can help to identify subjects at risk, thus reducing the incidence of fractures in the population. In recent years, researchers have shown that finite element models (FEMs) of the hip joint, derived from computed tomography (CT) images, can predict bone strength more accurately than other techniques currently used in the clinic. Read More

View Article and Full-Text PDF

Pulmonary embolism severity before and during the COVID-19 pandemic.

Br J Radiol 2021 Jun 9:20210264. Epub 2021 Jun 9.

Department of Radiology, Royal Infirmary of Edinburgh, Edinburgh, UK.

Objectives: Early in the coronavirus 2019 (COVID-19) pandemic, a high frequency of pulmonary embolism was identified. This audit aims to assess the frequency and severity of pulmonary embolism in 2020 compared to 2019.

Methods: In this retrospective audit, we compared computed tomography pulmonary angiography (CTPA) frequency and pulmonary embolism severity in April and May 2020, compared to 2019. Read More

View Article and Full-Text PDF