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JACC. Cardiovascular Imaging Dec 2020Coronary artery disease remains the leading cause of cardiovascular morbidity and mortality. Invasive X-ray angiography and coronary computed tomography angiography are... (Review)
Review
Coronary artery disease remains the leading cause of cardiovascular morbidity and mortality. Invasive X-ray angiography and coronary computed tomography angiography are established gold standards for coronary luminography. However, they expose patients to invasive complications, ionizing radiation, and iodinated contrast agents. Among a number of imaging modalities, coronary cardiovascular magnetic resonance (CMR) angiography may be used in some cases as an alternative for the detection and monitoring of coronary arterial stenosis, with advantages including its versatility, excellent soft tissue characterization, and avoidance of ionizing radiation and iodinated contrast agents. In this review, we explore the recent advances in motion correction, image acceleration, and reconstruction technologies that are bringing coronary CMR angiography closer to widespread clinical implementation.
Topics: Computed Tomography Angiography; Coronary Angiography; Coronary Artery Disease; Coronary Stenosis; Humans; Magnetic Resonance Angiography; Predictive Value of Tests
PubMed: 32199836
DOI: 10.1016/j.jcmg.2020.01.006 -
Whole-brain arteriography and venography: Using improved velocity-selective saturation pulse trains.Magnetic Resonance in Medicine Apr 2018To develop velocity-selective (VS) MR angiography (MRA) protocols for arteriography and venography with whole-brain coverage.
PURPOSE
To develop velocity-selective (VS) MR angiography (MRA) protocols for arteriography and venography with whole-brain coverage.
METHODS
Tissue suppression using velocity-selective saturation (VSS) pulse trains is sensitive to radiofrequency field (B +) inhomogeneity. To reduce its sensitivity, we replaced the low-flip-angle hard pulses in the VSS pulse train with optimal composite (OCP) pulses. Additionally, new pulse sequences for arteriography and venography were developed by placing spatially selective inversion pulses with a delay to null signals from either venous or arterial blood. The VS MRA techniques were compared to the time-of-flight (TOF) MRA in six healthy subjects and two patients at 3T.
RESULTS
More uniform suppression of stationary tissue was observed when the hard pulses were replaced by OCP pulses in the VSS pulse trains, which improved contrast ratios between blood vessels and tissue background for both arteries (0.87 vs. 0.77) and veins (0.80 vs. 0.59). Both arteriograms and venograms depicted all major cervical and intracranial arteries and veins, respectively. Compared to TOF MRA, VS MRA not only offers larger spatial coverage but also depicts more small vessels. Initial clinical feasibility was shown in two patients with comparisons to TOF protocols.
CONCLUSION
Noncontrast-enhanced whole-brain arteriography and venography can be obtained without losing sensitivity to small vessel detection. Magn Reson Med 79:2014-2023, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Topics: Adult; Angiography; Brain; Cerebral Angiography; Cerebrovascular Circulation; Computer Simulation; Female; Fourier Analysis; Humans; Image Interpretation, Computer-Assisted; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Male; Middle Aged; Models, Theoretical; Phlebography; Radio Waves
PubMed: 28799210
DOI: 10.1002/mrm.26864 -
Magma (New York, N.Y.) Oct 2020Coronary magnetic resonance angiography (coronary MRA) is advantageous in its ability to assess coronary artery morphology and function without ionizing radiation or... (Review)
Review
Coronary magnetic resonance angiography (coronary MRA) is advantageous in its ability to assess coronary artery morphology and function without ionizing radiation or contrast media. However, technical limitations including reduced spatial resolution, long acquisition times, and low signal-to-noise ratios prevent it from clinical routine utilization. Nonetheless, each of these limitations can be specifically addressed by a combination of novel technologies including super-resolution imaging, compressed sensing, and deep-learning reconstruction. In this paper, we first review the current clinical use and motivations for non-contrast coronary MRA, discuss currently available coronary MRA techniques, and highlight current technical developments that hold unique potential to optimize coronary MRA image acquisition and post-processing. In the final section, we examine the various research-based coronary MRA methods and metrics that can be leveraged to assess coronary stenosis severity, physiological function, and atherosclerotic plaque characterization. We specifically discuss how such technologies may contribute to the clinical translation of coronary MRA into a robust modality for routine clinical use.
Topics: Contrast Media; Coronary Angiography; Coronary Vessels; Heart; Magnetic Resonance Angiography
PubMed: 32242282
DOI: 10.1007/s10334-020-00834-8 -
Methodist DeBakey Cardiovascular Journal 2023The past decade has seen significant advances in dynamic imaging of the aorta. Today's vascular surgeons have the opportunity to choose from a wide array of imaging... (Review)
Review
The past decade has seen significant advances in dynamic imaging of the aorta. Today's vascular surgeons have the opportunity to choose from a wide array of imaging modalities to evaluate different aortic pathologies. While vascular ultrasound and aortography are considered to be the bread and butter imaging modalities, newer dynamic imaging techniques provide time-resolved information in various aortic pathologies. However, despite growing evidence of their advantages in the literature, they have not been routinely adopted. In order to understand the role of these emerging modalities, one must understand their principles, advantages, and limitations in the context of various clinical scenarios. In this review, we provide an overview of dynamic imaging techniques for aortic pathologies and describe various dynamic computed tomography and magnetic resonance imaging protocols, clinical applications, and potential future directions.
Topics: Humans; Magnetic Resonance Angiography; Aorta; Tomography, X-Ray Computed; Aortography; Magnetic Resonance Imaging
PubMed: 36910554
DOI: 10.14797/mdcvj.1172 -
The Neuroradiology Journal Feb 2015Advances in imaging modalities have improved the assessment of intracranial hemodynamics using non-invasive techniques. This review examines new imaging modalities and... (Review)
Review
Advances in imaging modalities have improved the assessment of intracranial hemodynamics using non-invasive techniques. This review examines new imaging modalities and clinical applications of currently available techniques, describes pathophysiology and future directions in hemodynamic analysis of intracranial stenoses, aneurysms and arteriovenous malformations and explores how hemodynamic analysis may have prognostic value in predicting clinical outcomes and assist in risk stratification. The advent of new technologies such as pseudo-continuous arterial spin labeling, accelerated magnetic resonance angiography (MRA) techniques, 4D digital subtraction angiography, and improvements in clinically available techniques such as phase-contrast MRA may change the landscape of vascular imaging and modify current clinical practice guidelines.
Topics: Angiography, Digital Subtraction; Brain Ischemia; Central Nervous System Vascular Malformations; Cerebral Angiography; Cerebrovascular Circulation; Four-Dimensional Computed Tomography; Hemodynamics; Humans; Intracranial Aneurysm; Intracranial Hemorrhages; Magnetic Resonance Angiography; Stroke
PubMed: 25924168
DOI: 10.15274/NRJ-2014-10115 -
Magma (New York, N.Y.) Apr 2023
Topics: Magnetic Resonance Imaging; Magnetic Resonance Angiography; Magnetic Resonance Spectroscopy
PubMed: 37072540
DOI: 10.1007/s10334-023-01087-x -
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 -
Cleveland Clinic Journal of Medicine Nov 2020Aneurysms of the renal artery and splenic artery are uncommon but clinically important, as they pose a risk of rupture with a high fatality rate. Indications for... (Review)
Review
Aneurysms of the renal artery and splenic artery are uncommon but clinically important, as they pose a risk of rupture with a high fatality rate. Indications for surgical or endovascular repair are based on aneurysm location and risk factors for rupture, such as aneurysm size, growth, and associated conditions, while medical management is also important. Regular surveillance with imaging is critical before and after intervention to guide treatment.
Topics: Aneurysm; Angiography; Humans; Renal Artery; Risk Assessment; Splenic Artery; Vascular Surgical Procedures; Watchful Waiting
PubMed: 33229392
DOI: 10.3949/ccjm.87a.19140-2 -
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 -
Zeitschrift Fur Medizinische Physik May 2022
Topics: Angiography; Thorium Dioxide
PubMed: 35248451
DOI: 10.1016/j.zemedi.2022.01.004