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Expert Review of Medical Devices Dec 2018Optical coherence tomography angiography (OCTA) is a noninvasive imaging modality for depth-resolved visualization of retinal vasculature. Angiographic data couples with... (Review)
Review
INTRODUCTION
Optical coherence tomography angiography (OCTA) is a noninvasive imaging modality for depth-resolved visualization of retinal vasculature. Angiographic data couples with structural data to generate a cube scan, from which en-face images of vasculature can be obtained at various axial positions. OCTA has expanded understanding of retinal vascular disorders and has primarily been used for qualitative analysis.
AREAS COVERED
Recent studies have explored the quantitative properties of OCTA, which would allow for objective assessment and follow-up of retinal pathologies. Various quantitative metrics have been developed, such as foveal avascular zone area and vessel density. However, quantitative assessment of the characteristics of retinal blood flow remains limited, as OCTA provides an image depicting either the presence or absence of flow at a particular region without information of relative velocities. The development of variable interscan time analysis (VISTA) overcomes this limitation. The VISTA algorithm generates a color-coded map of relative blood flow speeds. VISTA has already demonstrated utility in furthering our understanding of various retinal pathologies, such as geographic atrophy, choroidal neovascularization, aneurysmal type 1 neovascularization, and diabetic retinopathy.
EXPERT COMMENTARY
VISTA, an OCTA flow speed mapping technique, may have a role in developing the utility of OCTA as a screening tool.
Topics: Algorithms; Angiography; Humans; Retinal Diseases; Retinal Vessels; Tomography, Optical Coherence
PubMed: 30460869
DOI: 10.1080/17434440.2018.1548932 -
Interventional Neuroradiology : Journal... Dec 2022The vascular anatomy of orbit is highly complex, and the main blood supply to the orbit is via the ophthalmic artery, which is a branch of the internal carotid artery....
BACKGROUND
The vascular anatomy of orbit is highly complex, and the main blood supply to the orbit is via the ophthalmic artery, which is a branch of the internal carotid artery. The purpose of this study was to determine the morphometry of the ophthalmic artery and its branches by superselective angiography in a large series of pediatric patients.
METHODS
We evaluated 134 angiographies performed on children with intraocular retinoblastoma undergoing intra-arterial chemotherapy. The origin, diameter, and angiographic visibility percentages of the ophthalmic artery and its branches were examined according to age group and sex.
RESULTS
The ophthalmic artery originated 97.8% from the internal carotid artery and 2.2% from the middle meningeal artery. The mean diameter of ophthalmic artery was measured 0.76 ± 0.14 mm in girls, 0.80 ± 0.15 mm in boys and 0.79 ± 0.15 mm in general. The posterior ciliary, lacrimal, inferior muscular, and anterior ethmoidal arteries had a higher angiographic visibility percentages (> 85%) than the other OA branches. Only the diameter of the dorsal nasal artery showed a significant correlation with age. The supratrochlear and posterior ciliary arteries showed statistically significant relationship with sex.
CONCLUSIONS
Present study will make a substantial contribution to the pediatric literature about the ophthalmic artery and its branches. A better understanding of ophthalmic artery morphology can help surgeons and neurointerventional radiologists to avoid possible severe complications during embolization, intra-arterial chemotherapy, cosmetic procedures, endonasal and orbital surgeries.
Topics: Male; Female; Humans; Child; Ophthalmic Artery; Angiography; Carotid Artery, Internal; Meningeal Arteries; Retinal Neoplasms
PubMed: 35317633
DOI: 10.1177/15910199221067664 -
Japanese Journal of Radiology Sep 2022Conventional time-of-flight (TOF) magnetic resonance angiography (MRA) failed to depict clear visualization of coiled cerebral aneurysms with PulseRider due to...
PURPOSE
Conventional time-of-flight (TOF) magnetic resonance angiography (MRA) failed to depict clear visualization of coiled cerebral aneurysms with PulseRider due to metal-induced susceptibility artifacts. Our aim was to overcome the metal artifact using a novel imaging technique of non-contrast-enhanced ultrashort echo-time magnetic resonance angiography (UTE-MRA).
MATERIALS AND METHODS
Five unruptured intracranial aneurysms were treated using PulseRider and the patients underwent silent MRA (UTE-MRA). The images were compared with TOF-MRA and digital subtraction angiography (DSA).
RESULTS
Silent MRA can visualize the residual cavity of the coiled aneurysms, which was not well visualized and rather defective when using TOF-MRA. While a segment of the proximal marker composed of stainless steel was poorly visualized, the other parts of the parent artery and the arteries of bifurcation, including the aneurysmal neck, were clearly visualized, equivalent to that of DSA.
CONCLUSIONS
UTE-MRA achieves better visualization of cerebral aneurysms after PulseRider treatment than TOF-MRA.
Topics: Angiography, Digital Subtraction; Cerebral Angiography; Embolization, Therapeutic; Follow-Up Studies; Humans; Intracranial Aneurysm; Magnetic Resonance Angiography
PubMed: 35430678
DOI: 10.1007/s11604-022-01276-z -
Surgical and Radiologic Anatomy : SRA Jun 2021The embryological development of the cerebral vasculature is very complex. Historical and also more recent studies based on human embryos, comparative anatomy and... (Review)
Review
The embryological development of the cerebral vasculature is very complex. Historical and also more recent studies based on human embryos, comparative anatomy and cerebral angiographies allowed us to better understand this vasculature development. The knowledge and understanding of such embryological development are important for physicians interested in neurovascular pathologies. Indeed, all vascular variants and almost all vascular pathologies, such as aneurysms, dolichoectasia, atherosclerosis, and neurovascular conflicts could be explained by an alteration during the embryological life. There are also many variants of these vascular structures present in normal developed adults, which are variably associated with pathological entities. Understanding the process which leads to the development of the normal cerebral arterial system in humans is, therefore, very important to have a better knowledge of the possible clinical and surgical implications of these anomalies. In this paper, we review the embryological development of the cranio-facial arterial vasculature from its beginning at approximately days 21-50 of intrauterine life, with pictures illustrating each developmental phase.
Topics: Anatomy, Comparative; Cerebral Angiography; Cerebral Arteries; Embryo, Mammalian; Embryonic Development; Face; Humans; Medical Illustration
PubMed: 33492439
DOI: 10.1007/s00276-021-02684-y -
Diagnostic and Interventional Imaging Nov 2014Thanks to a simultaneous acquisition at high and low kilovoltage, dual energy computed tomography (DECT) can achieve material-based decomposition (iodine, water,... (Review)
Review
Thanks to a simultaneous acquisition at high and low kilovoltage, dual energy computed tomography (DECT) can achieve material-based decomposition (iodine, water, calcium, etc.) and reconstruct images at different energy levels (40 to 140keV). Post-processing uses this potential to maximise iodine detection, which elicits demonstrated added value for chest imaging in acute and chronic embolic diseases (increases the quality of the examination and identifies perfusion defects), follow-up of aortic endografts and detection of contrast uptake in oncology. In CT angiography, these unique features are taken advantage of to reduce the iodine load by more than half. This review article aims to set out the physical basis for the technology, the acquisition and post-processing protocols used, its proven advantages in chest pathologies, and to present future developments.
Topics: Angiography; Forecasting; Humans; Image Enhancement; Image Interpretation, Computer-Assisted; Radiography, Dual-Energy Scanned Projection; Radiography, Thoracic; Tomography, X-Ray Computed
PubMed: 24780370
DOI: 10.1016/j.diii.2014.01.001 -
AJNR. American Journal of Neuroradiology Nov 2022Patients with acute ischemic stroke are increasingly triaged with one-stop management approaches, resulting in baseline imaging with a flat detector CT scanner. This...
BACKGROUND AND PURPOSE
Patients with acute ischemic stroke are increasingly triaged with one-stop management approaches, resulting in baseline imaging with a flat detector CT scanner. This study aimed to estimate the effective dose to a patient of a novel cervical and intracranial flat detector CT angiography and a flat detector CT perfusion protocol and to compare it with the effective dose of analogous multidetector row CT protocols.
MATERIALS AND METHODS
We estimated the effective dose to the patient according to the International Commission on Radiological Protection 103 using an anthropomorphic phantom with metal oxide semiconductor field effect transistor dosimeters. Placement was according to the organ map provided by the phantom manufacturer. We used 100 measurement points within the phantom, and 18 metal oxide semiconductor field effect transistor dosimeters were placed on the surface of the phantom. All protocols followed the manufacturer's specifications, and patient positioning and collimation were performed as in routine clinical practice. Measurements were obtained on the latest-generation angiography and multidetector row CT systems with identical placement of the metal oxide semiconductor field effect transistor dosimeters.
RESULTS
The estimated effective doses of the investigated perfusion protocols were 4.52 mSv (flat detector CT perfusion without collimation), 2.88 mSv (flat detector CT perfusion with collimation), and 2.17 mSv (multidetector row CT perfusion). A novel protocol called portrait flat detector CT angiography that has a z-axis coverage area comparable with that of multidetector row CT angiography had an estimated effective dose of 0.91 mSv, while the dose from multidetector row CT was 1.35 mSv.
CONCLUSIONS
The estimated effective dose to the patient for flat detector CT perfusion and angiography on a modern biplane angiography system does not deviate substantially from that of analogous multidetector row CT protocols.
Topics: Humans; Radiation Dosage; Ischemic Stroke; Phantoms, Imaging; Angiography; Multidetector Computed Tomography; Stroke; Oxides
PubMed: 36202555
DOI: 10.3174/ajnr.A7658 -
Acta Neurologica Taiwanica Jun 2019ation. No significant past medical history except for pharmacologically controlled mild hypertension. During the neurological examination the patient appeared alert,...
ation. No significant past medical history except for pharmacologically controlled mild hypertension. During the neurological examination the patient appeared alert, oriented and showed no deficit of strength, sensitivity and coordination. An expressive temporary aphasia was confirmed and Transient Ischemic Attacks (TIA) was suspected. Cranial Computed Tomography Angiography (CTA) showed hypoplasia of left Internal Carotid Artery (ICA) with a focal duplication in the intracavernous segment (Figure 1, arrowhead). Circle of Willis appears to be regular, with the left middle cerebral artery supported by the vertebrobasilar system through the left posterior communicating artery of increased caliber, and by the contralateral ICA via anterior communicating artery. Consequently, patient underwent Digital Subtraction Angiography (DSA) lateral view that confirmed the segmental duplication of the left intracavernous ICA (Figure 2, arrowhead). Vessels had a lightly winding course within the cavernous sinus and the intracranial branches downstream of their confluence presented a slight delay in visualization. After few hours her symptoms completely regressed and, in agreement with clinical and imaging data, diagnosis of TIA was made. The transient ischemic event was, in fact, most likely caused by low flow to the left cerebral hemisphere due to hypoplasia of the ICA and aforementioned abnormalities of its intracavernous tract that caused alteration and reduction of intracranial flow distribution. Medical treatment with anti-platelet drugs was started and patient was discharged with a clinical, laboratory and imaging follow-up program. Duplications of ICA in the intracranial tract are very rare(1,2). Most of the cases are localized in the supraclinoid segment. To our knowledge this is the first case described in literature of true duplication of ICA in the intracavernous tract. Patients with congenital variants or acquired pathology of ICA are mostly asymptomatic, but when symptoms appear, patients must be investigated(1-3). CTA is considered the first line non-invasive diagnostic method for intracranial vascular anatomy. At present, medical treatment remains the choice in patients with no-complicated duplications of ICA in the intracranial tract.
Topics: Angiography, Digital Subtraction; Carotid Artery, Internal; Cerebral Angiography; Computed Tomography Angiography; Female; Humans
PubMed: 31867708
DOI: No ID Found -
Diabetes & Vascular Disease Research 2022Diabetes mellitus is significantly associated with posterior circulation ischemic stroke. We aimed to compare the characteristics of vertebrobasilar plaques in...
Comparison of symptomatic vertebrobasilar plaques between patients with and without Diabetes Mellitus using computed tomographic angiography and vessel wall magnetic resonance imaging.
OBJECTIVES
Diabetes mellitus is significantly associated with posterior circulation ischemic stroke. We aimed to compare the characteristics of vertebrobasilar plaques in symptomatic patients with and without diabetes using high-resolution vessel wall magnetic resonance imaging and computed tomographic angiography.
METHODS
From April 2017 to May 2021, cases from patients with transient ischemic attack or stroke in the posterior circulation territory who underwent high-resolution vessel wall magnetic resonance imaging and computed tomographic angiography were reviewed. Characteristics of culprit vertebrobasilar plaques were compared between patients with and without diabetes. Multivariate regression analysis was performed to assess the correlation between culprit plaque characteristics and diabetes.
RESULTS
A total of 148 patients were included and 75 patients were diagnosed with diabetes mellitus. Patients with diabetes had more intraplaque hemorrhage, calcification, spotty calcification presence, and higher calcification volume (all < 0.05) compared with those without diabetes. Multivariate analysis demonstrated differences in the presence of intraplaque hemorrhage ( = 0.045) and number of spotty calcifications ( = 0.047) were statistically significant after adjusting for baseline characteristics.
CONCLUSIONS
Symptomatic patients with diabetes have a higher incidence of intraplaque hemorrhage and larger calcification burden than those without diabetes, indicating the association of diabetes with more advanced plaque features in the posterior circulation.
Topics: Angiography; Calcinosis; Diabetes Mellitus; Hemorrhage; Humans; Magnetic Resonance Angiography; Magnetic Resonance Imaging; Plaque, Atherosclerotic; Stroke
PubMed: 35199586
DOI: 10.1177/14791641211073944 -
Contrast Media & Molecular Imaging 2019Magnetic resonance angiography (MRA) represents a clinical reference standard for the in vivo assessment of the vasculature. In this study, the potential of...
BACKGROUND
Magnetic resonance angiography (MRA) represents a clinical reference standard for the in vivo assessment of the vasculature. In this study, the potential of non-contrast-enhanced and contrast-enhanced angiography of the head/neck vasculature in mice on a clinical MR imaging system was tested.
METHODS
All in vivo magnetic resonance imaging was performed with a 3T clinical system (Siemens). Non-contrast-enhanced (time-of-flight, TOF) and contrast-enhanced angiography (gadofosveset-trisodium, GdT) were performed in C57BL/6J mouse strain. Lumen-to-muscle ratios (LMRs) and area measurements were assessed. Histology was performed as reference standard of all relevant vascular structures.
RESULTS
A close correlation between TOF ( = 0.79; < 0.05) and contrast-enhanced (GdT) angiography ( = 0.92; < 0.05) with histological area measurements was found. LMRs were comparable between both sequences. Regarding interobserver reproducibility, contrast-enhanced (GdT) angiography yielded a smaller 95% confidence interval and a closer interreader correlation compared to non-contrast-enhanced (TOF) measurements (-0.73-0.89; = 0.81 vs. -0.55-0.56; = 0.94).
CONCLUSION
This study demonstrates that non-contrast-enhanced and contrast-enhanced angiographies of the head/neck vasculature of small animals can reliably performed on a clinical 3T MR scanner. Contrast-enhanced angiography enables the visualization of vascular structures with higher intravascular contrast and higher reproducibility.
Topics: Animals; Contrast Media; Gadolinium; Head and Neck Neoplasms; Humans; Image Enhancement; Imaging, Three-Dimensional; Magnetic Resonance Angiography; Mice; Organometallic Compounds
PubMed: 31275084
DOI: 10.1155/2019/5461809 -
NeuroImage Sep 2021Accurate detection and quantification of unruptured intracranial aneurysms (UIAs) is important for rupture risk assessment and to allow an informed treatment decision to... (Comparative Study)
Comparative Study
Accurate detection and quantification of unruptured intracranial aneurysms (UIAs) is important for rupture risk assessment and to allow an informed treatment decision to be made. Currently, 2D manual measures used to assess UIAs on Time-of-Flight magnetic resonance angiographies (TOF-MRAs) lack 3D information and there is substantial inter-observer variability for both aneurysm detection and assessment of aneurysm size and growth. 3D measures could be helpful to improve aneurysm detection and quantification but are time-consuming and would therefore benefit from a reliable automatic UIA detection and segmentation method. The Aneurysm Detection and segMentation (ADAM) challenge was organised in which methods for automatic UIA detection and segmentation were developed and submitted to be evaluated on a diverse clinical TOF-MRA dataset. A training set (113 cases with a total of 129 UIAs) was released, each case including a TOF-MRA, a structural MR image (T1, T2 or FLAIR), annotation of any present UIA(s) and the centre voxel of the UIA(s). A test set of 141 cases (with 153 UIAs) was used for evaluation. Two tasks were proposed: (1) detection and (2) segmentation of UIAs on TOF-MRAs. Teams developed and submitted containerised methods to be evaluated on the test set. Task 1 was evaluated using metrics of sensitivity and false positive count. Task 2 was evaluated using dice similarity coefficient, modified hausdorff distance (95 percentile) and volumetric similarity. For each task, a ranking was made based on the average of the metrics. In total, eleven teams participated in task 1 and nine of those teams participated in task 2. Task 1 was won by a method specifically designed for the detection task (i.e. not participating in task 2). Based on segmentation metrics, the top two methods for task 2 performed statistically significantly better than all other methods. The detection performance of the top-ranking methods was comparable to visual inspection for larger aneurysms. Segmentation performance of the top ranking method, after selection of true UIAs, was similar to interobserver performance. The ADAM challenge remains open for future submissions and improved submissions, with a live leaderboard to provide benchmarking for method developments at https://adam.isi.uu.nl/.
Topics: Cerebral Angiography; Datasets as Topic; Educational Measurement; Humans; Intracranial Aneurysm; Magnetic Resonance Angiography; Magnetic Resonance Imaging; Random Allocation; Risk Assessment
PubMed: 34052465
DOI: 10.1016/j.neuroimage.2021.118216