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Magnetic Resonance in Medicine Sep 2015To improve the spatial/temporal resolution of whole-heart coronary MR angiography by developing a variable-density (VD) 3D cones acquisition suitable for image...
PURPOSE
To improve the spatial/temporal resolution of whole-heart coronary MR angiography by developing a variable-density (VD) 3D cones acquisition suitable for image reconstruction with parallel imaging and compressed sensing techniques.
METHODS
A VD 3D cones trajectory design incorporates both radial and spiral trajectory undersampling techniques to achieve higher resolution. This design is used to generate a VD 3D cones trajectory with 0.8 mm/66 ms isotropic spatial/temporal resolution, using a similar number of readouts as our previous fully sampled cones trajectory (1.2 mm/100 ms). Scans of volunteers and patients are performed to evaluate the performance of the VD trajectory, using non-Cartesian L1 -ESPIRiT for high-resolution image reconstruction.
RESULTS
With gridding reconstruction, the high-resolution scans experience an expected drop in signal-to-noise and contrast-to-noise ratios, but with L1 -ESPIRiT, the apparent noise is substantially reduced. Compared with 1.2 mm images, in each volunteer, the L1 -ESPIRiT 0.8 mm images exhibit higher vessel sharpness values in the right and left anterior descending arteries.
CONCLUSION
Coronary MR angiography with isotropic submillimeter spatial resolution and high temporal resolution can be performed with VD 3D cones to improve the depiction of coronary arteries.
Topics: Aged; Coronary Angiography; Female; Humans; Imaging, Three-Dimensional; Magnetic Resonance Angiography; Male; Middle Aged; Phantoms, Imaging; Signal-To-Noise Ratio
PubMed: 26172829
DOI: 10.1002/mrm.25803 -
Journal of the American College of... Jun 2016
Topics: Angiography; Cardiac Catheterization; Cardiology; Curriculum; Education, Medical, Graduate; Fellowships and Scholarships; Humans; Societies, Medical; United States
PubMed: 27282900
DOI: 10.1016/j.jacc.2016.05.001 -
Surgery Dec 2022In recent years, indocyanine green angiography (ICG-A) has been used increasingly to assist tissue perfusion assessments during plastic and reconstructive surgery...
Delphi survey of intercontinental experts to identify areas of consensus on the use of indocyanine green angiography for tissue perfusion assessment during plastic and reconstructive surgery.
BACKGROUND
In recent years, indocyanine green angiography (ICG-A) has been used increasingly to assist tissue perfusion assessments during plastic and reconstructive surgery procedures, but no guidelines exist regarding its use. We sought to identify areas of consensus and non-consensus among international experts on the use of ICG-A for tissue-perfusion assessments during plastic and reconstructive surgery.
METHODS
A two-round, online Delphi survey was conducted of 22 international experts from four continents asking them to vote on 79 statements divided into five modules: module 1 = patient preparation and contraindications (n = 11 statements); module 2 = ICG administration and camera settings (n = 17); module 3 = other factors impacting perfusion assessments (n = 10); module 4 = specific indications, including trauma debridement (n = 9), mastectomy skin flaps (n = 6), and free flap reconstruction (n = 8); and module 5 = general advantages and disadvantages, training, insurance coverage issues, and future directions (n = 18). Consensus was defined as ≥70% inter-voter agreement.
RESULTS
Consensus was reached on 73/79 statements, including the overall value, advantages, and limitations of ICG-A in numerous surgical settings; also, on the dose (0.05 mg/kg) and timing of ICG administration (∼20-60 seconds preassessment) and best camera angle (61-90) and target-to-tissue distance (20-30 cm). However, consensus also was reached that camera angle and distance can vary, depending on the make of camera, and that further research is necessary to technically optimize this imaging tool. The experts also agreed that ambient light, patient body temperature, and vasopressor use impact perfusion assessments.
CONCLUSION
ICG-A aids perfusion assessments during plastic and reconstructive surgery and should no longer be considered experimental. It has become an important surgical tool.
Topics: Humans; Female; Indocyanine Green; Breast Neoplasms; Mastectomy; Plastic Surgery Procedures; Angiography; Perfusion
PubMed: 36427930
DOI: 10.1016/j.surg.2022.04.015 -
Clinical Medicine & Research Mar 2021To assess the quality of reporting in diagnostic accuracy studies (DAS) referenced by the Quality Improvement Guidelines for Diagnostic Arteriography and their...
To assess the quality of reporting in diagnostic accuracy studies (DAS) referenced by the Quality Improvement Guidelines for Diagnostic Arteriography and their adherence to the Standards for Reporting of Diagnostic Accuracy (STARD) statement. Citations specific to the Society of Interventional Radiology's Quality Improvement Guidelines for Diagnostic Arteriography were collected. Using the 34-item STARD checklist, two authors in a duplicate and blinded fashion documented the number of items reported per diagnostic accuracy study. Authors met, and any discrepancies were resolved in a resolution meeting. Of the 26 diagnostic accuracy studies included, the mean number of STARD items reported was 17.8 (SD ± 3.1). The median adherence was 18 (IQR, 17-19) items. Ten articles were published prior to 2003, the original date of STARD publication, and 16 articles were published after 2003. The mean number of reported items for the articles published prior to STARD 2003, and after STARD 2003 was 17.4 (SD ± 2.4) and 18.1 (SD ± 3.5), respectively. There were 14 STARD items that demonstrated an adherence of < 25%, and 13 an adherence > 75%. The dichotomous distribution of adherence to the STARD statement by DAS investigated demonstrates that areas of deficient reporting may be present and require attention to ensure complete and transparent reporting in the future.
Topics: Angiography; Guideline Adherence; Humans; Radiology, Interventional; Research Design
PubMed: 33547165
DOI: 10.3121/cmr.2020.1549 -
American Journal of Veterinary Research May 2022To evaluate the enhancement accuracy of a triple-phase abdominal CT angiography (CTA) protocol in dogs and explore the patient, scan, and contrast parameters associated...
OBJECTIVE
To evaluate the enhancement accuracy of a triple-phase abdominal CT angiography (CTA) protocol in dogs and explore the patient, scan, and contrast parameters associated with accuracy of enhancement.
ANIMALS
233 client-owned dogs that underwent routine abdominal CTA.
PROCEDURES
During each CTA study, the subjective timing accuracy (early, ideal, late) of the 3 obtained vascular phases (arterial, venous, delayed) was scored by consensus (2 reviewers) at 4 target organs (liver, pancreas, left kidney, and spleen). These scores were evaluated for statistical associations with 21 study variables (patient, scan, and contrast medium). The objective enhancement (HU) for each target organ was also compared statistically with subjective timing accuracy scores and the study variables.
RESULTS
The study protocol performed best for the pancreas, moderately for the liver, and worse for the spleen and left kidney. Measurements of scan length and time were associated positively with phase lateness for most target organs and phases. Increased heart rate was the most significant patient factor associated positively with phase lateness within the liver (all phases), pancreas (arterial and venous phases), and kidney (arterial phase). Contrast medium variables were less associated with timing accuracy in this protocol. Objective enhancement (HU) correlated poorly with subjective phase timing accuracy and study variables.
CLINICAL RELEVANCE
Scan time, scan length, and heart rate were the predominant variables contributing to lateness in this canine abdominal CTA protocol. The findings of this exploratory study may aid in protocol adjustment and choice of included anatomy for dogs undergoing routine abdominal CTA.
Topics: Abdomen; Angiography; Animals; Computed Tomography Angiography; Contrast Media; Dogs; Liver
PubMed: 35930776
DOI: 10.2460/ajvr.21.03.0031 -
European Radiology Jan 2018Traditional contrast-enhanced methods for scanning blood vessels using magnetic resonance imaging (MRI) or CT carry potential risks for patients with advanced kidney...
OBJECTIVES
Traditional contrast-enhanced methods for scanning blood vessels using magnetic resonance imaging (MRI) or CT carry potential risks for patients with advanced kidney disease. Ferumoxytol is a superparamagnetic iron oxide nanoparticle preparation that has potential as an MRI contrast agent in assessing the vasculature.
METHODS
Twenty patients with advanced kidney disease requiring aorto-iliac vascular imaging as part of pre-operative kidney transplant candidacy assessment underwent ferumoxytol-enhanced magnetic resonance angiography (FeMRA) between December 2015 and August 2016. All scans were performed for clinical indications where standard imaging techniques were deemed potentially harmful or inconclusive. Image quality was evaluated for both arterial and venous compartments.
RESULTS
First-pass and steady-state FeMRA using incremental doses of up to 4 mg/kg body weight of ferumoxytol as intravenous contrast agent for vascular enhancement was performed. Good arterial and venous enhancements were achieved, and FeMRA was not limited by calcification in assessing the arterial lumen. The scans were diagnostic and all patients completed their studies without adverse events.
CONCLUSIONS
Our preliminary experience supports the feasibility and utility of FeMRA for vascular imaging in patients with advanced kidney disease due for transplant listing, which has the advantages of obtaining both arteriography and venography using a single test without nephrotoxicity.
KEY POINTS
• Evaluation of vascular disease is important in planning kidney transplantation. • Standard vascular imaging methods are often problematic in kidney disease patients. • FeMRA has the advantage of arteriography and venography in a single test. • FeMRA is safe and non-nephrotoxic. • FeMRA is not limited by arterial calcification.
Topics: Contrast Media; Female; Ferrosoferric Oxide; Humans; Image Enhancement; Kidney; Kidney Transplantation; Magnetic Resonance Angiography; Male; Middle Aged; Patient Selection
PubMed: 28677065
DOI: 10.1007/s00330-017-4934-5 -
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 -
PloS One 2021To investigate any associations between cigarette smoking and retinal microvascular changes in diabetic patients without visible retinopathy.
PURPOSE
To investigate any associations between cigarette smoking and retinal microvascular changes in diabetic patients without visible retinopathy.
DESIGN
Retrospective, cross-sectional study.
PARTICIPANTS
1099 eyes from 1099 diabetic patients with no clinical evidence of diabetic retinopathy (DR) were included in this study.
METHODS
Diabetic patients underwent optical coherence tomography angiography (OCTA) scanning at Zuckerberg San Francisco General Hospital and Trauma Center between April 2018 and September 2019. Patient demographic and clinical information was collected. Standard bivariate statistics and multivariate linear regression were performed.
MAIN OUTCOME MEASURES
OCTA parameters included metrics related to the foveal avascular zone (FAZ; area, perimeter, circularity), perfusion density (PD; full, center, inner), and vessel length density (VLD; full, center, inner).
RESULTS
The study population included 750 non-smokers and 349 smokers. FAZ perimeter was the only OCTA parameter that was significantly different between the two groups on uncontrolled analysis (P = 0.033). Multivariate regression analyses revealed significant associations between lower VLD full (β = -0.31, P = 0.048), lower VLD inner (β = -0.35, P = 0.046) and a history of smoking. No significant associations between cigarette smoking and either FAZ or PD were detected.
CONCLUSIONS
Our results suggest that smoking is likely associated with deleterious changes in the retinal microvasculature of patients with a history of diabetes and no visible DR. Based on these findings, diabetic patients with a history of smoking may benefit from higher prioritization in terms of ophthalmic screening.
Topics: Aged; Angiography; Cigarette Smoking; Cross-Sectional Studies; Diabetic Retinopathy; Ex-Smokers; Female; Humans; Macula Lutea; Male; Middle Aged; Non-Smokers; Retinal Vessels; Retrospective Studies; Risk Factors; Smokers; Tomography, Optical Coherence
PubMed: 34242286
DOI: 10.1371/journal.pone.0253928 -
Epilepsia Sep 2019Various forms of vascular imaging are performed to identify vessels that should be avoided during stereoelectroencephalography (SEEG) planning. Digital subtraction...
OBJECTIVE
Various forms of vascular imaging are performed to identify vessels that should be avoided during stereoelectroencephalography (SEEG) planning. Digital subtraction angiography (DSA) is the gold standard for intracranial vascular imaging. DSA is an invasive investigation, and a balance is necessary to identify all clinically relevant vessels and not to visualize irrelevant vessels that may unnecessarily restrict electrode placement. We sought to estimate the size of vessels that are clinically significant for SEEG planning.
METHODS
Thirty-three consecutive patients who underwent 354 SEEG electrode implantations planned with computer-assisted planning and DSA segmentation between 2016 and 2018 were identified from a prospectively maintained database. Intracranial positions of electrodes were segmented from postimplantation computed tomography scans. Each electrode was manually reviewed using "probe-eye view" with the raw preoperative DSA images for vascular conflicts. The diameter of vessels and the location of conflicts were noted. Vessel conflicts identified on raw DSA images were cross-referenced against other modalities to determine whether the conflict could have been detected.
RESULTS
One hundred sixty-six vessel conflicts were identified between electrodes and DSA-identified vessels, with 0-3 conflicts per electrode and a median of four conflicts per patient. The median diameter of conflicting vessels was 1.3 mm (interquartile range [IQR] = 1.0-1.5 mm). The median depth of conflict was 31.0 mm (IQR = 14.3-45.0 mm) from the cortical surface. The addition of sulcal models to DSA, magnetic resonance venography (MRV), and T1 + gadolinium images, as an exclusion zone during computer-assisted planning, would have prevented the majority of vessel conflicts. We were unable to determine whether vessels were displaced or transected by the electrodes.
SIGNIFICANCE
Vascular segmentation from DSA images was significantly more sensitive than T1 + gadolinium or MRV images. Electrode conflicts with vessels 1-1.5 mm in size did not result in a radiologically detectable or clinically significant hemorrhage and could potentially be excluded from consideration during SEEG planning.
Topics: Angiography, Digital Subtraction; Blood Vessels; Brain; Cerebral Angiography; Electrodes, Implanted; Electroencephalography; Female; Humans; Male; Neurosurgical Procedures
PubMed: 31329275
DOI: 10.1111/epi.16294 -
Interventional Neuroradiology : Journal... Aug 2022Transradial access is widely used in cardiological adult interventions and less in pediatrics. In recent years, this access has become more popular in the...
Transradial access is widely used in cardiological adult interventions and less in pediatrics. In recent years, this access has become more popular in the neuroradiological community in adult patients since it has fewer complications and is more comfortable for the patient after the procedure. We present a single-center case series of 52 transradial access neurointerventions (43 angiographies and 9 therapeutic procedures) in pediatric patients, with a failure of 4 cases (7.7%) in which we could not puncture the artery, crossing over to transfemoral access. Since in five cases we did angiography followed by therapeutic intervention, thus doing only one puncture access for both procedures, then our access failure rate was 10.6%. The 34 successful transradial access solely angiographies had a median radiation exposure of 887 mGy (interquartile range 628-1352), median fluoroscopy time of 9.5 min (interquartile range 7.5-15.3), and median procedure time of 28 min (interquartile range 24-33 min) Therapeutic procedure diagnosis were: one ruptured saccular aneurysm, two juvenile nasopharyngeal angiofibromas, and five arteriovenous malformations. The transradial access neurointerventions for pediatric population older than 11 years is safe and feasible, having previous experience in adults. Younger population should be considered on a case-to-case basis, depending on ultrasound measurement of the arterial diameter and the materials available.
Topics: Adolescent; Angiography; Feasibility Studies; Humans; Neurosurgical Procedures; Radial Artery; Treatment Outcome
PubMed: 34515565
DOI: 10.1177/15910199211041868