Noninvasive Vascular Imaging Research Articles

Noninvasive vascular imaging of polypoidal choroidal vasculopathy by Doppler optical coherence tomography.

To noninvasively investigate the vascular architecture of polypoidal lesions in polypoidal choroidal vasculopathy (PCV) using Doppler optical coherence tomography (OCT), and to evaluate the clinical usefulness of Doppler OCT for the assessment of therapeutic effects in PCV. Fifteen eyes of 15 patients with treatment-naïve PCV were prospectively studied. Vascular imaging was obtained using 1060-nm swept-source Doppler OCT, and compared with indocyanine green angiography (ICGA) images. The therapeutic effect of three consecutive intravitreal aflibercept injections was evaluated with ICGA and Doppler OCT. In Doppler OCT images, polypoidal lesions were clearly detected at the corresponding locations of lesions in the ICGA images. By being insensitive to dye leakage, Doppler OCT identified the complicated vascular structure in the polypoidal lesions. The identified mean area of the polypoidal lesions in the Doppler OCT images (0.04 mm(2)) was significantly smaller than that of the ICGA images (0.13 mm(2)). Polypoidal lesions were located in the retinal pigment epithelial detachment in 13 eyes, in the choroid in one eye, and in both the retinal pigment epithelial detachment and choroid in one eye. After intravitreal aflibercept treatment, areas of polypoidal lesions in the ICGA images were decreased in 14 of 15 eyes. This therapeutic effect was clearly confirmed in the Doppler OCT images. Doppler OCT imaging clearly detected fine vascular structures at the polypoidal lesions in PCV. Doppler OCT might be useful for the diagnosis and evaluation of therapeutic effects in PCV.

FIRST IN MAN OBSERVATIONS WITH SIMULTANEOUS 18F-FDG PET AND MR IMAGING IN PERIPHERAL ARTERY DISEASE USING A WHOLE-BODY INTEGRATED SCANNER

Advanced non-invasive vascular imaging simultaneously combining positron emission tomography (PET) with magnetic resonance imaging (MRI) has recently been made possible. This observational study attempted to identify patients with peripheral artery disease (PAD) at risk for vascular events using

Abstract No. 394 - Non-invasive vascular imaging and endovascular therapy for non-ischemic priapism

We aim to provide the reader with an educational depiction of the imaging findings and endovascular treatment options for non-ischemic priapism. A retrospective review of all the cases of non-ischemic priapism managed in our department in a period of 10 years: from August 2004 to August 2014. Specific examples of embolization cases were retrieved. We carried out a review of the current literature Non-ischemic (arterial, high-flow) priapism is usually the result of perineal or penile trauma. The injury results in a laceration in the cavernosal artery leading to the formation of a fistula between the artery and the lacunar spaces of the sinusoidal tissue. The diagnosis is usually made clinically and is aided by corporal blood aspiration and blood gas analysis. The role of non-invasive vascular imaging, both in diagnosis and in aiding conservative management (site specific perineal compression) is explored. Selective arterial embolization can be performed, usually after failure of conservative management. The relative merits of the different embolic agents used are summarised. The relevant angiographic anatomy is also presented. The operator must be familiar with the relevant anatomy including the critical variations which may necessitate alterations in technique. Non-ischemic priapism is a rare clinical entity that usually results from blunt trauma. Unlike ischemic priapism, it is not an emergency. Non-invasive vascular imaging can be performed to confirm the diagnosis and aid conservative management. Transarterial embolization can provide a definitive treatment in selected patients when conservative therapy has failed.

Abstract T P46: Final Infarct Volume Discriminates Outcome In Mild Strokes

Introduction: Final infarct volume (FIV) is a well-established predictor of outcomes in moderate and severe stroke. However, our knowledge of how FIV predicts disability in the mild stroke population is very limited. Our objective was to determine if FIV could differentiate good versus poor outcome after mild stroke. We hypothesized that smaller FIV will be associated with favorable clinical outcome. Methods: We used a retrospective, multicenter registry for consecutive patients who presented with mild stroke (NIHSS ≤ 5) within 24 hours of stroke onset. The imaging data included baseline head CT, noninvasive vascular imaging and follow up imaging (24-72 hour MR/3-5 day CT). Baseline ASPECTS, proximal arterial occlusion (PAO), collateral scores and FIV (using MIPAV) were assessed by core lab. Clinical data included age, sex, baseline NIHSS and 90 day modified Rankin Scale (mRS). Logistic regression was used to evaluate associations between favorable outcome (mRS 0-1) and imaging and clinical data, and to determine a data-driven cut-point for FIV based on the maximal sensitivity and specificity of the receiver operating characteristic curve. Results: Among 90 patients with mild stroke, 3 who received intravenous thrombolysis and 22 who did not have follow-up imaging were excluded, leaving 65 patients (mean age 86 years, 38% female, median NIHSS score 4) in whom FIV calculations were performed. An optimal FIV cut-point at 20 cc was identified, for differentiating between favorable and poor outcomes (area under curve 0.73, 95% CI: 0.58-0.88). Of the 45 patients with FIV <20 cc, 37 (82%) had a favorable outcome compared to 5 out of 14 (36%) with FIV ≥ 20 cc (P<.01). In the multivariable model, FIV ≥ 20cc remained strongly associated with poor outcome (adjusted OR, 0.11; 95% CI, 0.02- 0.50, P<.01), irrespective of age, gender, stroke severity, ASPECTS and PAO. A higher collateral score was also found to be associated with favorable outcome (adjusted OR, 2.43; 95% CI, 1.12- 5.27, P=0.02). Conclusions: A final infarct volume cut point of 20 cc was found to best differentiate between the likelihood of good versus poor outcome in patients with mild stroke. Further validation of FIV as a surrogate marker is essential to improve risk prediction in mild stroke patients.

Abstract T P312: Utility of Early MRI in Intracerebral Hemorrhage

Introduction: Intracerebral hemorrhage (ICH) causes significant morbidity and mortality. Utility of early magnetic resonance imaging (MRI) is not fully understood. Identifying patients in whom early MRI changes clinical management may improve outcomes in select patients and reduce costs overall by avoiding inpatient MRIs in patients who are unlikely to benefit. Hypothesis: We assessed the hypothesis that early MRI in patients with spontaneous ICH does not alter management acutely in older patients. Methods: We conducted a retrospective chart review of all ICH admitted to our institution from 2006-2012. Patients were excluded if they 1) had a known underlying lesion, 2) were < 18 years, 3) suffered ICH as a result of trauma or 4) did not undergo MRI. Data were evaluated for clinical or radiographic characteristics that resulted in a change in clinical management, including surgical intervention or future avoidance of antithrombotic medications, among others. Results: In total, 248 patients with a median age of 70 years (IQR 58-78) were included. MRI changed management in 79 patients (31.9%). Initial MRI was obtained an average of 10 days after the hemorrhage. Possible structural abnormalities requiring emergent intervention were found in 14 (17.7%) patients, while 64 (81.0%) had findings concerning for other non-emergent/non-surgical anomalies (possible tumor (n=6), cavernoma (n=7), alternate diagnosis (n=1), probable amyloid angiopathy (n=21), evaluation for embolic phenomenon (n=13), evaluation for vasculitis (n=2), abnormal edema/enhancement (n=8), MRI led to additional non-invasive vascular imaging (n=6)). One patient (1.3%) was found to have a venous sinus thrombosis prompting anticoagulation. MRI was more likely to result in a change in management in patients < 55 years of age (47.1% vs 27.9%, p=0.009). Conclusions: MRI after ICH changed management in approximately one-third of patients and resulted in an immediate change in management in a minority of patients. Younger patients are more likely to benefit from early MRI. In older patients suspected of amyloid angiopathy that may preclude future antithrombotic therapy, delayed MRI in the outpatient setting may be reasonable.

Echolucency of the carotid artery intima-media complex and intima-media thickness have different cardiovascular risk factor relationships: the Women's Interagency HIV Study.

BackgroundAdults infected with HIV have increased atherosclerosis potentially associated with both HIV and non‐HIV associated factors. We characterized risk factors for atherosclerosis as measured by noninvasive vascular imaging.Methods and ResultsWe used B‐mode ultrasound to examine levels and correlates of echogenicity and vessel wall thickness of the carotid artery intima‐media complex in 1282 HIV‐infected and 510 HIV‐uninfected women of the Women's Interagency HIV Study. Levels of gray scale median (GSM, a measure of echogenicity) did not vary between HIV infection groups. In both groups, smokers had increased GSM, whereas age, diabetes, elevated blood pressure, and high BMI were associated with lower (rather than higher) GSM. Each of these non‐lipid CVD risk factors, especially age and blood pressure, was also associated with higher levels of carotid artery intima‐media thickness (cIMT). Higher serum triglyceride levels were associated with lower GSM in both HIV‐infected and HIV‐uninfected groups. Additional lipid risk factors for low GSM including high LDL cholesterol and low HDL cholesterol levels were identified in HIV uninfected but not in HIV infected women. In contrast to findings for GSM, among the lipid parameters only LDL cholesterol level had an association with cIMT, which was observed only in the HIV uninfected group.ConclusionsLipid and non‐lipid risk factor associations with echolucency of the carotid artery and the thickness of the common carotid artery intima‐media layer suggest that these measures capture different aspects of atherosclerosis.

Reversible Cerebral Vasoconstriction Syndrome, Part 2: Diagnostic Work-Up, Imaging Evaluation, and Differential Diagnosis.

The diagnostic evaluation of a patient with reversible cerebral vasoconstriction syndrome integrates clinical, laboratory, and radiologic findings. Imaging plays an important role by confirming the presence of cerebral vasoconstriction; monitoring potential complications such as ischemic stroke; and suggesting alternative diagnoses, including CNS vasculitis and aneurysmal subarachnoid hemorrhage. Noninvasive vascular imaging, including transcranial Doppler sonography and MR angiography, has played an increasingly important role in this regard, though conventional angiography remains the criterion standard for the evaluation of cerebral artery vasoconstriction. Newer imaging techniques, including high-resolution vessel wall imaging, may help in the future to better discriminate reversible cerebral vasoconstriction syndrome from primary angiitis of the CNS, an important clinical distinction.

Coincident intrasellar persistent trigeminal artery and craniopharyngioma: case report and implications for transsphenoidal surgery

The persistent trigeminal artery (PTA) is the largest and most commonly occurring type of remnant fetal arteries, typically originating from the posterior bend or lateral wall of the intracavernous carotid artery. There are no published reports of coexisting PTA and midline epithelial tumors. We describe a coincident case of craniopharyngioma associated with an adjacent PTA traversing through the sella turcica, which are both developmental midline skull base anomalies. The caliber and location of the PTA precluded an endoscopic endonasal operation; the tumor was safely resected via a supraorbital keyhole approach. Anatomic implications pertaining to surgical approach and treatment are also discussed. Surgeons performing endonasal skull base operations should be vigilant for the presence of PTAs and related vascular anomalies on MR imaging. Noninvasive vascular imaging can confirm and assist with preoperative planning. • First known description of a craniopharyngioma coincidently occurring with a persistent trigeminal artery, both extremely rare events. • The origin and classification of both craniopharyngiomas and persistent trigeminal arteries are explained. • The persistent trigeminal artery was an unexpected finding and could have been dangerous if not found pre-operatively. • It is imperative that all skull base surgeons use the appropriate imaging to detect possible vascular abnormalities and be wary of abnormal vasculature during surgical planning.

Non-invasive vascular imaging is associated with cardiovascular risk factors among adolescents with bipolar disorder.

Cardiovascular disease (CVD) is exceedingly prevalent among adults with bipolar disorder (BD), implicating BD adolescents as a high-risk group for CVD. Non-invasive ultrasound measures of vascular structure (via carotid intima media thickness [cIMT]) and function (via flow-mediated dilation [FMD]) predict future CVD, and are associated with traditional CVD risk factors among adolescents without mood disorders. This study examined, for the first time, the association of cIMT and FMD with CVD risk factors among adolescents with BD. The presence of multiple potential confounds among adolescents with BD, including various medications and mood states, informs the need to demonstrate whether cIMT and FMD are associated with CVD risk factors in this population specifically. Participants were 30 adolescents, 13-19years old, with BD, without CVD. High-resolution ultrasonography was used to evaluate vascular structure (cIMT) and function (FMD). Analyses examined associations of cIMT and FMD with traditional CVD risk factors. cIMT was significantly positively associated with systolic blood pressure and waist circumference. FMD was significantly negatively associated with waist circumference, body mass index, triglycerides, and glucose, and positively associated with high-density lipoprotein. cIMT and FMD are associated with traditional CVD risk factors among adolescents with BD. Irrespective of numerous potential confounds, non-invasive vascular ultrasound approaches may be used as CVD risk proxies among adolescents with BD as they are for other adolescents.

Contrast enhanced MRA with CAPR (Cartesian Acquisition with Projection like Reconstruction) technique - review of initial clinical experience

Background Contrast enhanced MRA is a well validated and widely used technique for noninvasive vascular imaging. Significant advances in coil development, parallel imaging, and view-sharing techniques can enable imaging with very high spatial and/or temporal resolution which can be tailored to very specific or problematic clinical situations. Cartesian acquisition with projection like reconstruction (CAPR) is a specific technique developed by our MR Research laboratory which supports very high acceleration factors and has been adopted into clinical practice for a number of clinical scenarios. We will present a brief introduction to the technique and an illustrative review of our early clinical experience using CAPR for clinical imaging. Methods CAPR apportions the Cartesian phase-encoded kY -kZ plane into a low-spatial-frequency center region and a high-spatial-frequency outer annulus. The annulus is further divided into sets of projection-like vanes. The corners of the kY -kZ plane are not sampled and are zero-filled, and data for the unsampled gaps between vanes are estimated by 2D homodyne processing. An individual image update consists of elliptical-centric sampling of the center region and one annular vane set, with view sharing applied from previous samples of the other vane sets. This vane pattern gives a visual appearance similar to projection reconstruction. Alternate vanes are sampled or not sampled, allowing for 2D homodyne detection to be performed across the kY-kZ plane. Because homodyne detection is performed in this plane, full echoes are sampled along the readout (kX) direction. Results We have used this technique in both single station and multi-station implementations, the latter using a novel technique of “fluoro-tracking” enabled by real-time reconstruction of image data to allow interactive decision making by the technologist to track the passage of a contrast bolus through multiple stations. We will present a number of cases illustrating the use, including imaging of arteriovenous malformations, imaging peripheral vascular runoff to facilitate bypass graft planning the setting of failed prior CTA, and imaging of the small vessels of the hands and feet. Conclusions

Noninvasive Vascular Imaging in Abdominal Solid Organ Transplantation

In this article, we focus on the vascular complications related to liver, pancreas, and kidney transplantation. Long term allograft survival of solid organ transplantation depends on early intervention of complications. Noninvasive imaging with ultrasound, CT, and MRI allows accurate diagnosis of complications and aids in treatment planning.

Brainstem Strokes in Children: An 11-Year Series From a Tertiary Pediatric Center

MethodsPotential clinical barriers to making a timely diagnosis of pediatric brainstem stroke and pitfalls of noninvasive vascular imaging are presented. MethodsAn institutional review board–approved institutional database query from 2001-2012 yielded 15 patients with brainstem strokes. Medical records were reviewed for symptoms, stroke severity using the Pediatric National Institutes of Health Stroke Scale, and outcomes using the Pediatric Stroke Outcome Measure. Magnetic resonance angiography was compared with digital subtraction angiography. ResultsThere were 10 boys and five girls; 9 months to 17 years of age (mean 7.83 years). Symptoms were headaches (eight); visual problems (eight), seizure-like activity (seven), motor deficits (six), and decreased level of consciousness in four. Time since last seen well was 12 hours to 5 days. Pediatric National Institutes of Health Stroke Scale was 1-34; <10 in eight; 3 in 1, 10-20 in two, and >20 in four. Strokes were pontine in 13/15 and involved >50% of the pons in six and <50% in seven; 2/15 had medullary strokes. Magnetic resonance angiography showed basilar artery occlusion in 8/13 patients and vertebral artery dissection in two. Digital subtraction angiography done within 9-36 hours of magnetic resonance angiography in 10/15 patients confirmed the basilar artery occlusion seen by magnetic resonance angiography and showed vertebral artery dissection in four patients. Patients were systemically anticoagulated without hemorrhagic complications. One patient died. Pediatric Stroke Outcome Measures at 2-36 months is 0-5.0/10 (mean 1.25). ConclusionsVague symptoms contributed to delays in diagnosis. Magnetic resonance angiography was equivalent to digital subtraction angiography for basilar artery occlusion but not for vertebral artery dissection. Even with basilar artery occlusion and high stroke scales, outcome was good when systemic anticoagulation was started promptly.

A radioanatomic study of the internal mammary artery and its perforators using multidetector computed tomography angiography

The Internal Mammary Artery (IMA) and its perforators play an important role in coronary bypass grafting and reconstructive breast, head, and neck surgery. This study aimed to obtain anatomic data pertaining to these vessels using Multi Detector Computed Tomography Angiography (MDCTA) and to demonstrate that the MDCTA could be a considerable assessment tool prior to surgery. In 50 outpatients (27 males and 23 females), the above-mentioned arteries were bilaterally evaluated with a 16-detector spiral computed tomography scanner. Based on the obtained images, diameters of the bilateral IMAs were separately measured in each intercostal spaces from 1 to 5 through their traces. IMAPs greater than 0.5 mm in diameter were bilaterally evaluated in terms of distance from the sternal border to the ramification point under the muscular layer, maximal external diameter at ramification from the IMA, and the length between the ramification point from the IMA and enter point to the subcutaneous fat tissue. Mean diameters of the left and right IMAs were 2.05 ± 0.50 mm and 2.20 ± 0.57 mm, respectively. Mean diameters, distances, and lengths of the perforators were 1.30 ± 0.30 mm, 6.80 ± 3.40 mm, 17.05 ± 6.07 mm on the left side and 1.32 ± 0.25 mm, 6.71 ± 3.43 mm, 17.35 ± 3.48 mm on the right side, respectively. No statistically difference was found between the sides (P > 0.05). About 20 of 36 perforators appeared in the second intercostal space, whereas there were eight in the first and eight in the third intercostal space. MDCTA, as a non-invasive vascular imaging method, can be a valuable tool for investigating the anatomic characteristics of the IMA and its perforators before planning an operation.

Development of Dual Beam High Speed Doppler OFDI

This paper describes development of a high speed Doppler OFDI system for non-invasive vascular imaging. Doppler OFDI (optical frequency domain imaging) is one of the phase-resolved second generation OCT (optical coherence tomography) techniques for high resolution imaging of moving elements in biological tissues. To achieve a phase-resolved imaging, two temporally separated measurements are required. In a conventional Doppler OCT, a pair of massively oversampled successive A-lines is used to minimize de-correlation noise at the expense of significant imaging speed reduction. To minimize a de-correlation noise between targeted two measurements without suffering from significant imaging speed reduction, several methods have been developed such as an optimized scanning pattern and polarization multiplexed dual beam scanning. This research represent novel imaging technique using frequency multiplexed dual beam illumination to measure exactly same position with aimed time interval. Developed system has been verified using a tissue phantom and mouse vessel imaging.

Spinal Dural Arteriovenous Fistulas: A Review

Spinal dural arteriovenous fistulas (SDAVF) are a rare pathologic entity with a diverse and often misleading clinical presentation. While digital subtraction spinal angiography remains the gold standard, recent advances in noninvasive vascular imaging have improved the diagnosis of SDAVF. As this condition can result in permanent spinal cord injury, all patients require treatment, which consists of surgical or endovascular occlusion of the fistula. Failure to recognize and treat SDAVF in a timely fashion can result in irreversible neurologic disability, including myelopathy, lower extremity weakness and bowel, bladder and sexual dysfunction. This article reviews the clinical features, pathogenesis, radiographic features and current treatment strategies for these complex lesions.

Non-invasive vascular imaging in perforator flap surgery.

Preoperative imaging using a range of imaging modalities has become increasingly popular for preoperative planning in plastic surgery, in particular in perforator flap surgery. Modalities in this role include ultrasound (US), magnetic resonance angiography (MRA), and computed tomographic angiography (CTA). The evidence for the use of these techniques has been reported in only a handful of studies. In this paper we conducted a non-systematic review of the literature to establish the role for each of these modalities. The role of state-of-the-art vascular imaging as an application in perforator flap surgery is thus offered.

Shared associations of nonatherosclerotic, large-vessel, cerebrovascular arteriopathies

With ongoing advancements in noninvasive vascular imaging and high-throughput genomics, we have the opportunity to reclassify the cerebrocervical disorders by these shared associations, rather than their downstream events, and to better understand etiology, mechanism and preventive treatments going forward. The common nonatherosclerotic, large-vessel arteriopathies affecting the cerebrovasculature include intracranial aneurysms, cervical artery dissection, fibromuscular dysplasia and moyamoya disease. Together, these entities contribute to a high incidence of devastating cerebrovascular outcomes, including ischemic stroke and subarachnoid hemorrhage, leading to long-term physical and cognitive disability frequently in young otherwise healthy adults. In addition to well reported clinical overlap, these polygenic phenotypes share epidemiological characteristics, environmental risk and a common pathological weakening of the arterial wall. We reviewed both past and present studies relating these shared associations, including reported candidate gene analyses and genome-wide association data. We also catalogue recent descriptions of novel arteriopathic syndromes that add to the growing list of monogenic connective tissue disease affecting the arterial wall, and further inform our understanding of more common polygenic phenotypes. We also place these cerebrocervical arteriopathies in the context of other systemic nonatherosclerotic, large-vessel vascular disease (e.g. aortic aneurysm and dissection).

Coronary vessel wall thickening in asymptomatic young HIV-infected patients vs. controls using phase-sensitive dual inversion recovery (PS-DIR) MRI

Background HIV-infected patients demonstrate premature and more severe vascular disease relative to controls. Therefore, development of a reproducible non-invasive vascular imaging biomarker in this population is important. The purpose of this study was to assess coronary artery wall thickness in young HIV-infected patients who acquired HIV in early life compared to healthy controls using a novel black-blood coronary vessel wall MR imaging technique.

Emergency Noninvasive Angiography for Acute Intracerebral Hemorrhage

Spontaneous ICH is a devastating condition and is associated with significant mortality in the acute phase due to ongoing hemorrhage and hematoma expansion. A growing body of evidence suggests that there may be considerable utility in performing noninvasive vascular imaging during the acute-to-early phase of ICH. CTA has become widely available and is sensitive and specific for detecting vascular causes of secondary ICH such as aneurysms, arteriovenous malformations, dural arteriovenous fistulas, intracranial dissections, and neoplasm. CT venography can also diagnose dural sinus thrombosis presenting as hemorrhagic infarction. Recent data from stroke populations demonstrate a relatively low risk to patients when contrast is administered in the absence of a known serum creatinine. Detection of acute contrast extravasation within the hematoma ("spot sign") with CT angiography is predictive of subsequent hematoma expansion and is associated with increased morbidity and mortality. Risk stratification based on acute CTA can inform and expedite decision-making regarding intensive care unit admission, blood pressure control, correction of coagulopathy, and neurosurgical consultation. Noninvasive vascular imaging should be considered as an important component of the initial diagnostic work-up for patients presenting with acute ICH.

Bildgebungsstrategie bei Kniegelenkverletzungen

Injuries of the knees are common. The Ottawa knee rule provides decisional support to determine whether radiographs are indicated or not. With the use of ultrasound it is possible to detect defects of the extensor ligaments and the anterior cruciate ligament. Furthermore, it is possible to detect indirect signs of an intra-articular fracture, e.g. lipohemarthrosis. In complex fractures, e.g. tibial plateau fractures, further diagnostic procedures with multislice computed tomography (CT) are needed for accurate classification and preoperative planning. Multislice CT with CT angiography enables three-dimensional reconstruction of the knee and non-invasive vascular imaging for detection of vascular injury. Magnetic resonance imaging (MRI) is the gold standard for detection of occult fractures and injuries of the ligaments and menisci. Higher field strengths can be used to improve the diagnostics of cartilage lesions. Virtual MR arthrography is superior to conventional MRI for detection of cartilage lesions especially after meniscus surgery.