Aortic disease in patients with Marfan syndrome: aortic volume assessment for surveillance.

Purpose: To assess the reproducibility of aortic volume estimates and to serially test their use in patients with Marfan syndrome.

Materials And Methods: The study was approved by the medical ethics committee and all subjects gave written informed consent. In 81 patients with Marfan syndrome and seven healthy control subjects, aortic volumes and diameters at baseline were estimated by means of contrast material-enhanced magnetic resonance (MR) imaging.

3D cine phase-contrast MRI at 3T in intracranial aneurysms compared with patient-specific computational fluid dynamics.

Background And Purpose: CFD has been proved valuable for simulating blood flow in intracranial aneurysms, which may add to better rupture risk assessment. However, CFD has drawbacks such as the sensitivity to assumptions needed for the model, which may hinder its clinical implementation. 3D PC-MR imaging is a technique that enables measurements of blood flow.

Automated cerebral infarct volume measurement in follow-up noncontrast CT scans of patients with acute ischemic stroke.

Background And Purpose: Cerebral infarct volume as observed in follow-up CT is an important radiologic outcome measure of the effectiveness of treatment of patients with acute ischemic stroke. However, manual measurement of CIV is time-consuming and operator-dependent. The purpose of this study was to develop and evaluate a robust automated measurement of the CIV.

Carotid pseudo-occlusion on CTA in patients with acute ischemic stroke: a concerning observation.

Objective: Differentiation between an occluded and a patent extracranial internal carotid artery (ICA) is crucial in the diagnostic workup of patients with acute ischemic stroke; particularly in patients eligible for endovascular treatment. We report neurological and radiological findings of cases in which CTA in the acute phase incorrectly revealed an occlusion of the ICA.

Methods: In our image data base of 54 patients with acute ischemic stroke eligible for endovascular treatment, we searched for patients with an occluded extracranial ICA on CTA whereas DSA proved that this artery was patent.

Wall shear stress estimated with phase contrast MRI in an in vitro and in vivo intracranial aneurysm.

Purpose: To evaluate wall shear stress (WSS) estimations in an in vitro and in vivo intracranial aneurysm, WSS was estimated from phase contrast magnetic resonance imaging (PC-MRI) and compared with computational fluid dynamics (CFD).

Materials And Methods: First, WSS was estimated using a high-resolution in vitro PC-MRI measurement under steady and pulsatile flow conditions and compared with CFD simulations. Second, WSS was estimated in steady PC-MRI data acquired at different spatial resolutions.

Three-dimensional rotational angiography of the foot in critical limb ischemia: a new dimension in revascularization strategy.

Purpose: To evaluate the additional value of three-dimensional rotational angiography (3DRA) of the foot compared with digital subtraction angiography (DSA) in patients with critical limb ischemia (CLI).

Technique: For 3DRA, the C-arm was placed in the propeller position with the foot in an isocentric position. The patient's unaffected foot was positioned in a footrest outside the field of view.

Intracranial carotid artery disease in patients with recent neurological symptoms: high prevalence on CTA.

Introduction: Novel postprocessing techniques have enabled accurate quantification of intracranial carotid atherosclerotic disease on CT Angiography (CTA). Our purpose was to estimate the prevalence of intracranial carotid artery disease, i.e.

k-t BLAST and SENSE accelerated time-resolved three-dimensional phase contrast MRI in an intracranial aneurysm.

Objective: The objective of this study was to investigate the performance of k-t BLAST (Broad-use Linear Acquisition Speed-up Technique) accelerated time-resolved 3D PC-MRI compared to SENSE (SENSitivity Encoding) acceleration in an in vitro and in vivo intracranial aneurysm.

Materials And Methods: Non-accelerated, SENSE and k-t BLAST accelerated time-resolved 3D PC-MRI measurements were performed in vivo and in vitro. We analysed the consequences of various temporal resolutions in vitro.

Intracranial aneurysm neck size overestimation with 3D rotational angiography: the impact on intra-aneurysmal hemodynamics simulated with computational fluid dynamics.

Background And Purpose: 3DRA is considered the reference standard for the assessment of intracranial aneurysm morphology. However, it has been shown that 3DRA may overestimate neck size compared with 2D DSA. The purpose of this study was to determine the impact of neck size overestimation with 3DRA on intra-aneurysmal hemodynamics.

Differences in CT perfusion summary maps for patients with acute ischemic stroke generated by 2 software packages.

Background And Purpose: Although CT perfusion is a promising tool to support treatment decisions for patients with acute ischemic stroke, it still lacks a standardized method for CTP analysis. The purpose of this study was to assess the variability of the area of infarct core and penumbra as presented in summary maps produced by 2 different software packages.

Materials And Methods: Forty-one CTP image datasets of 26 consecutive patients who presented with acute ischemic stroke were retrospectively evaluated.

Semi-automatic quantitative measurements of intracranial internal carotid artery stenosis and calcification using CT angiography.

Introduction: Intracranial carotid artery atherosclerotic disease is an independent predictor for recurrent stroke. However, its quantitative assessment is not routinely performed in clinical practice. In this diagnostic study, we present and evaluate a novel semi-automatic application to quantitatively measure intracranial internal carotid artery (ICA) degree of stenosis and calcium volume in CT angiography (CTA) images.

Performance of semiautomatic assessment of carotid artery stenosis on CT angiography: clarification of differences with manual assessment.

Background And Purpose: Semiautomated methods for ICA stenosis measurements have the potential to reduce interobserver variability and to speed up its analysis. In this study, we estimate the precision and accuracy of a semiautomated measurement for carotid artery stenosis degree and identify and explain differences compared with the manual method.

Materials And Methods: In this retrospective study involving 90 patients, 2 observers determined the stenosis degree twice, with both the semiautomated and the manual method.

Multiscale flow patterns within an intracranial aneurysm phantom.

Straightforward quantification of variations of flow patterns within aneurysms fails to accurately describe flow patterns of interest. We applied a multiscale decomposition of the flow in well-defined patterns to detect and quantify flow patterns in an aneurysm phantom that was studied with three different modalities: MRI, computational fluid dynamics, and particle image velocimetry. The method intuitively visualizes main patterns such as locally uniform flow, in- and outflow, and vortices.

The relation of carotid calcium volume with carotid artery stenosis in symptomatic patients.

Background And Purpose: Recent research showed a strong correlation of calcium volume scores with degree of stenosis, suggesting that calcium volume could be used in the diagnosis of carotid artery stenosis. We investigated the accuracy of the use of calcium volume scores to diagnose carotid artery stenosis in our target population of recently symptomatic patients.

Materials And Methods: Ninety symptomatic patients suspected of having carotid artery stenosis underwent CTA, resulting in images of 159 evaluable arteries.

Complex flow patterns in a real-size intracranial aneurysm phantom: phase contrast MRI compared with particle image velocimetry and computational fluid dynamics.

The aim of this study was to validate the flow patterns measured by high-resolution, time-resolved, three-dimensional phase contrast MRI in a real-size intracranial aneurysm phantom. Retrospectively gated three-dimensional phase contrast MRI was performed in an intracranial aneurysm phantom at a resolution of 0.2 × 0.

Model-based measurements of the diameter of the internal carotid artery in CT angiography images.

Purpose: Computed tomography angiography (CTA) is often used to determine the degree of stenosis in patients that suffer from carotid artery occlusive disease. Accurate and precise measurements of the diameter of the stenosed internal carotid artery are required to make decisions on treatment of the patient. However, the inherent blurring of images hampers a straightforward measurement, especially for smaller vessels.

Accuracy of noninvasive coronary stenosis quantification of different commercially available dedicated software packages.

Purpose: The purpose of this study was to investigate the noninvasive quantification of coronary artery stenosis using cardiac software packages and vessel phantoms with known stenosis severity.

Materials And Methods: Four different sizes of vessel phantoms were filled with contrast agent and scanned on a 64-slice multidetector computed tomography. Diameter and area stenosis were evaluated by 2 observers blinded from the true measures using 5 different software packages.

Automatic initialization algorithm for carotid artery segmentation in CTA images.

Analysis of CT datasets is commonly time consuming because of the required manual interaction. We present a novel and fast automatic initialization algorithm to detect the carotid arteries providing a fully automated approach of the segmentation and centerline detection. First, the volume of interest (VOI) is estimated using a shoulder landmark.

Towards quantitative analysis of coronary CTA.

The current high spatial and temporal resolution, multi-slice imaging capability, and ECG-gated reconstruction of multi-slice computed tomography (MSCT) allows the non-invasive 3D imaging of opacified coronary arteries. MSCT coronary angiography studies are currently carried out by the visual inspection of the degree of stenosis and it has been shown that the assessment with sensitivities and specificities of 90% and higher can be achieved. To increase the reproducibility of the analysis, we present a method that performs the quantitative analysis of coronary artery diseases with limited user interaction: only the positioning of one or two seed points is required.