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Asia-Pacific Journal of Ophthalmology... 2017The use of imaging for age-related macular degeneration (AMD) depends on how it benefits clinical management and on reimbursement. The latter should relate to the... (Review)
Review
The use of imaging for age-related macular degeneration (AMD) depends on how it benefits clinical management and on reimbursement. The latter should relate to the former. This review assesses how different forms of AMD can be imaged and what information this provides. For nonneovascular AMD high-resolution optical coherence tomography (OCT), autofluorescence, and near infrared imaging can identify the type of drusen, such as reticular pseudodrusen, which influences prognosis, and the amount of atrophy, for which phase 3 trials are underway. Clarifying the correct diagnosis for late-onset Stargardt and macular telangiectasia, if treatment becomes available, will be especially important. Choroidal thickness can be measured and changes with anti‒vascular endothelial growth factor treatment, but how this influences management is less clear. The finding of a thick choroid may alter the diagnosis to pachychoroid neovasculopathy, which may have a different treatment response. Peripheral retinal changes are commonly found on ultrawide-field imaging but their importance is not yet determined. The mainstay of imaging is OCT, which can detect neovascular AMD by detecting thickening and be used for follow-up, as the presence or absence of thickening is the main determinant of treatment. Higher resolution systems and now OCT angiography are able to distinguish neovascular type, especially type 2 choroidal neovascularization but also polypoidal choroidal vasculopathy and retinal angiomatous proliferation. Fundus fluorescein and indocyanine green angiographies still have a role, although that partly depends on whether photodynamic therapy is being considered. Automated image analysis and machine learning will be increasingly important in supporting clinician decisions.
Topics: Choroidal Neovascularization; Diagnostic Techniques, Ophthalmological; Fluorescein Angiography; Geographic Atrophy; Humans; Macular Degeneration; Tomography, Optical Coherence
PubMed: 28905541
DOI: 10.22608/APO.2017305 -
Developments in Ophthalmology 2016Optical coherence tomography angiography (OCTA) can be used to visualize alterations in the choriocapillaris of patients with dry age-related macular degeneration (AMD).... (Review)
Review
Optical coherence tomography angiography (OCTA) can be used to visualize alterations in the choriocapillaris of patients with dry age-related macular degeneration (AMD). These changes seem to be present during all stages of the disease. Earlier stages are associated with patchy thinning of the choriocapillaris, while geographic atrophy is associated with loss of choriocapillaris lying under the area of geographic atrophy and asymmetric alteration of choriocapillaris at the margins of the geographic atrophy. The use of high-speed, long-wave-length swept-source OCT for angiography, with its better penetration into the choroid and high acquisition speeds, enable OCTA with scaled slowest detectable flow and fastest distinguishable flow. This will enable us to better investigate choriocapillaris changes in patients with dry AMD. The ability to image the choriocapillaris structure and flow impairments may be useful in the future for detecting and monitoring the progression of dry AMD and for monitoring treatment responses in clinical trials to therapies that target disease progression in dry AMD.
Topics: Angiography; Geographic Atrophy; Humans; Tomography, Optical Coherence
PubMed: 27023214
DOI: 10.1159/000442784 -
EuroIntervention : Journal of EuroPCR... Aug 2017Evaluation of non-invasive imaging modalities is shifting to an assessment of their effect on clinical outcomes rather than of their diagnostic accuracy. For this... (Review)
Review
Evaluation of non-invasive imaging modalities is shifting to an assessment of their effect on clinical outcomes rather than of their diagnostic accuracy. For this reason, we present the most useful and commonly used non-invasive tests in the clinical scenario of patients with suspected or already known coronary artery disease in terms of their diagnostic accuracy and prognostic stratification. Each of the four sections, dedicated to a single imaging method (echocardiography, coronary computed tomography angiography, nuclear imaging and cardiac magnetic resonance), describes its early clinical applications, the main current indications and the more promising future field of interest.
Topics: Coronary Angiography; Coronary Artery Disease; Echocardiography, Stress; Heart; Humans; Magnetic Resonance Angiography; Myocardial Ischemia
PubMed: 28844028
DOI: 10.4244/EIJ-D-17-00466 -
The Neuroradiology Journal Jun 2022Among the varied causes of pulsatile tinnitus, the condition that can cause severe mortality and morbidity is a cranial dural arteriovenous fistula (cDAVF). This study...
BACKGROUND
Among the varied causes of pulsatile tinnitus, the condition that can cause severe mortality and morbidity is a cranial dural arteriovenous fistula (cDAVF). This study aimed to assess the diagnostic accuracy of the dilated middle meningeal artery on three-dimensional time-of-flight magnetic resonance angiography in cranial dural arteriovenous fistula and to identify other feeders that can aid in the detection of these lesions.
METHOD
Magnetic resonance angiography and digital subtraction angiography data of all patients with cranial dural arteriovenous fistula treated in a single tertiary referral center between 2007-2020 were included. The middle meningeal artery and other feeders recorded from digital subtraction angiography were assessed on magnetic resonance angiography.
RESULTS
The overall agreement between readers in identifying the dilated middle meningeal artery was substantial (κ = 0.878, 95% confidence interval: 0.775-0.982). The dilated middle meningeal artery indicated the presence of a cranial dural arteriovenous fistula with a sensitivity of 79.49% (95% confidence interval: 66.81-92.16), specificity of 100% (95% confidence interval: 100.00-100.00), and negative predictive value of 94.56% (95% confidence interval: 90.89-98.02). An area under the curve of 0.8341 was observed for the ipsilateral middle meningeal artery, with a sensitivity of 92.2% and a specificity of 75.0% at a cut-off of 0.30 mm for identifying a cranial dural arteriovenous fistula. Of 73 other feeders, the occipital, meningohypophyseal trunk, ascending pharyngeal, and posterior meningeal arteries contributed to a large proportion visualized on magnetic resonance angiography (83.6% (41/49)).
CONCLUSION
The dilated middle meningeal artery sign is useful for identifying a cranial dural arteriovenous fistula. Dilatation of the occipital and ascending pharyngeal arteries and meningohypophyseal trunk should be assessed to facilitate the detection of a cranial dural arteriovenous fistula, particularly in the transverse-sigmoid and petrous regions.
Topics: Angiography, Digital Subtraction; Central Nervous System Vascular Malformations; Humans; Magnetic Resonance Angiography; Meningeal Arteries; Skull
PubMed: 34449286
DOI: 10.1177/19714009211041530 -
Ultrasound in Medicine & Biology Oct 2020Cancerous tumor growth is associated with the development of tortuous, chaotic microvasculature, and this aberrant microvascular morphology can act as a biomarker of... (Review)
Review
Cancerous tumor growth is associated with the development of tortuous, chaotic microvasculature, and this aberrant microvascular morphology can act as a biomarker of malignant disease. Acoustic angiography is a contrast-enhanced ultrasound technique that relies on superharmonic imaging to form high-resolution 3-D maps of the microvasculature. To date, acoustic angiography has been performed with dual-element transducers that can achieve high contrast-to-tissue ratio and resolution in pre-clinical small animal models. In this review, we first describe the development of acoustic angiography, including the principle, transducer design, and optimization of superharmonic imaging techniques. We then detail several preclinical applications of this microvascular imaging method, as well as the current and future development of acoustic angiography as a pre-clinical and clinical diagnostic tool.
Topics: Acoustics; Angiography; Animals; Contrast Media; Forecasting; Humans; Microvessels; Neoplasms; Neovascularization, Pathologic; Ultrasonography
PubMed: 32703659
DOI: 10.1016/j.ultrasmedbio.2020.06.009 -
AJNR. American Journal of Neuroradiology May 2018Deep learning is a branch of artificial intelligence that has demonstrated unprecedented performance in many medical imaging applications. Our purpose was to develop a...
BACKGROUND AND PURPOSE
Deep learning is a branch of artificial intelligence that has demonstrated unprecedented performance in many medical imaging applications. Our purpose was to develop a deep learning angiography method to generate 3D cerebral angiograms from a single contrast-enhanced C-arm conebeam CT acquisition in order to reduce image artifacts and radiation dose.
MATERIALS AND METHODS
A set of 105 3D rotational angiography examinations were randomly selected from an internal data base. All were acquired using a clinical system in conjunction with a standard injection protocol. More than 150 million labeled voxels from 35 subjects were used for training. A deep convolutional neural network was trained to classify each image voxel into 3 tissue types (vasculature, bone, and soft tissue). The trained deep learning angiography model was then applied for tissue classification into a validation cohort of 8 subjects and a final testing cohort of the remaining 62 subjects. The final vasculature tissue class was used to generate the 3D deep learning angiography images. To quantify the generalization error of the trained model, we calculated the accuracy, sensitivity, precision, and Dice similarity coefficients for vasculature classification in relevant anatomy. The 3D deep learning angiography and clinical 3D rotational angiography images were subjected to a qualitative assessment for the presence of intersweep motion artifacts.
RESULTS
Vasculature classification accuracy and 95% CI in the testing dataset were 98.7% (98.3%-99.1%). No residual signal from osseous structures was observed for any 3D deep learning angiography testing cases except for small regions in the otic capsule and nasal cavity compared with 37% (23/62) of the 3D rotational angiographies.
CONCLUSIONS
Deep learning angiography accurately recreated the vascular anatomy of the 3D rotational angiography reconstructions without a mask. Deep learning angiography reduced misregistration artifacts induced by intersweep motion, and it reduced radiation exposure required to obtain clinically useful 3D rotational angiography.
Topics: Artifacts; Cerebral Angiography; Deep Learning; Humans; Image Interpretation, Computer-Assisted; Imaging, Three-Dimensional; Tomography, X-Ray Computed
PubMed: 29567655
DOI: 10.3174/ajnr.A5597 -
Chinese Medical Journal Jun 2016To discuss the feasibility and clinical value of high-resolution magnetic resonance vessel wall imaging (HRMR VWI) for intracranial arterial stenosis. (Review)
Review
OBJECTIVE
To discuss the feasibility and clinical value of high-resolution magnetic resonance vessel wall imaging (HRMR VWI) for intracranial arterial stenosis.
DATE SOURCES
We retrieved information from PubMed database up to December 2015, using various search terms including vessel wall imaging (VWI), high-resolution magnetic resonance imaging, intracranial arterial stenosis, black blood, and intracranial atherosclerosis.
STUDY SELECTION
We reviewed peer-reviewed articles printed in English on imaging technique of VWI and characteristic findings of various intracranial vasculopathies on VWI. We organized this data to explain the value of VWI in clinical application.
RESULTS
VWI with black blood technique could provide high-quality images with submillimeter voxel size, and display both the vessel wall and lumen of intracranial artery simultaneously. Various intracranial vasculopathies (atherosclerotic or nonatherosclerotic) had differentiating features including pattern of wall thickening, enhancement, and vessel remodeling on VWI. This technique could be used for determining causes of stenosis, identification of stroke mechanism, risk-stratifying patients, and directing therapeutic management in clinical practice. In addition, a new morphological classification based on VWI could be established for predicting the efficacy of endovascular therapy.
CONCLUSIONS
This review highlights the value of HRMR VWI for discrimination of different intracranial vasculopathies and directing therapeutic management.
Topics: Carotid Stenosis; Cerebral Angiography; Humans; Intracranial Arteriosclerosis; Magnetic Resonance Angiography
PubMed: 27231176
DOI: 10.4103/0366-6999.182826 -
Tomography (Ann Arbor, Mich.) Sep 2022Gastrointestinal bleeding is a potentially life-threatening abdominal emergency that remains a common cause of hospitalisation. Although 80-85% of cases of... (Review)
Review
Gastrointestinal bleeding is a potentially life-threatening abdominal emergency that remains a common cause of hospitalisation. Although 80-85% of cases of gastrointestinal bleeding resolve spontaneously, it can result in massive haemorrhage and death. The presentation of gastrointestinal bleeding can range from asymptomatic or mildly ill patients requiring only conservative treatments to severely ill patients requiring immediate intervention. Identifying the source of the bleeding can be difficult due to the wide range of potential causes, the length of the gastrointestinal tract and the intermittent nature of the bleeding. The diagnostic and therapeutic approach is fully dependent on the nature of the bleeding and the patient's haemodynamic status. Radiologists should be aware of the appropriate uses of computed tomography angiography and other imaging modalities in patients with acute gastrointestinal bleeding, as well as the semiotics of bleeding and diagnostic pitfalls in order to appropriately diagnose and manage these patients. The learning objective of this review is to illustrate the computed tomography angiography technique, including the potential role of dual-energy computed tomography angiography, also highlighting the tips and tricks to identify the most common and uncommon features of acute gastrointestinal bleeding and its obscure form.
Topics: Humans; Computed Tomography Angiography; Angiography; Gastrointestinal Hemorrhage; Tomography, X-Ray Computed; Acute Disease
PubMed: 36287797
DOI: 10.3390/tomography8050198 -
Interventional Neuroradiology : Journal... Feb 2022There is no study on the role of three-dimensional compressed sensing time of flight MR angiography (3D-CS-TOF) in the management of the WEB device. We evaluated the...
PURPOSE
There is no study on the role of three-dimensional compressed sensing time of flight MR angiography (3D-CS-TOF) in the management of the WEB device. We evaluated the efficacy of 3-tesla 3D-CS-TOF for the management and follow-up of the WEB device implantations.
MATERIALS AND METHODS
Seventy-three aneurysms of 69 patients treated with the WEB device were retrospectively examined. Morphological parameters and embolization results of the aneurysms were assessed and compared on 3D-CS-TOF, CTA, and DSA images.
RESULTS
Occluded, neck remnant, and recurrent aneurysms were observed in 61 (83.6%), 7 (9.6%), and 5 (6.8%) aneurysms, respectively. Inter- and intra-reader agreement values related to aneurysm size measurements were perfect. Aneurysms size, age, and proximal vessel tortuosity were negatively correlated with the visibility of the aneurysms and parent vessels on 3D-CS-TOF images (p = 0.043; p = 0.032; p < 0.001, respectively). Subarachnoid hemorrhage and age are associated with 3D-CS-TOF artifacts (p = 0.031; p = 0.005, respectively). 3D-CS-TOF findings are in perfect agreement with DSA or CT angiography (CTA) results (p < 0.001).
CONCLUSION
According to our results, 3D-CS-TOF can be an easy, fast, and reliable alternative for the management or follow-up of WEB assisted embolization.
Topics: Angiography, Digital Subtraction; Cerebral Angiography; Computed Tomography Angiography; Follow-Up Studies; Humans; Imaging, Three-Dimensional; Intracranial Aneurysm; Magnetic Resonance Angiography; Retrospective Studies; Sensitivity and Specificity
PubMed: 33957798
DOI: 10.1177/15910199211014708 -
JACC. Cardiovascular Interventions Dec 2016
Topics: Coronary Angiography; Fractional Flow Reserve, Myocardial
PubMed: 27838266
DOI: 10.1016/j.jcin.2016.10.003