Peter Drivas

Improved respiratory efficiency of 3D late gadolinium enhancement imaging using the continuously adaptive windowing strategy (CLAWS)

Acquisition durations of navigator‐gated high‐resolution three‐dimensional late gadolinium enhancement studies may typically be up to 10 min, depending on the respiratory efficiency and heart rate. Implementation of the continuously adaptive windowing strategy (CLAWS) could increase respiratory efficiency, but the resulting non‐smooth k‐space acquisition order during gadolinium wash‐out could result in increased artifact.

Navigator artifact reduction in three-dimensional late gadolinium enhancement imaging of the atria.

Navigator‐gated three‐dimensional (3D) late gadolinium enhancement (LGE) imaging demonstrates scarring following ablation of atrial fibrillation. An artifact originating from the slice‐selective navigator‐restore pulse is frequently present in the right pulmonary veins (PVs), obscuring the walls and making quantification of enhancement difficult. We describe a simple sequence modification to greatly reduce or remove this artifact.

Free-breathing 3D late gadolinium enhancement imaging of the left ventricle using a stack of spirals at 3T.

To develop navigator‐gated free‐breathing 3D spiral late gadolinium enhancement (LGE) imaging of the left ventricle at 3T and compare it with conventional breath‐hold 2D Cartesian imaging.

Cardiovascular magnetic resonance: Diagnostic utility and specific considerations in the pediatric population

Cardiovascular magnetic resonance is a non-invasive imaging modality which is emerging as important tool for the investigation and management of pediatric cardiovascular disease. In this review we describe the key technical and practical differences between scanning children and adults, and highlight some important considerations that must be taken into account for this patient population. Using case examples commonly seen in clinical practice, we discuss the important clinical applications of cardiovascular magnetic resonance, and briefly highlight key future developments in this field.

Atherosclerosis is evident in treated HIV-infected subjects with low cardiovascular risk by carotid cardiovascular magnetic resonance

Objective:Premature atherosclerosis has been observed among HIV-infected individuals with high cardiovascular risk using one-dimensional ultrasound carotid intima-media thickness. We evaluated the assessment of HIV-infected individuals with low traditional cardiovascular disease risk using cardiovascular magnetic resonance, which allows three-dimensional assessment of the carotid artery wall. Methods:Carotid cardiovascular magnetic resonance was performed in 33 HIV-infected individuals (cases) (19 male, 14 female), and 35 HIV-negative controls (20 male, 15 female). Exclusion criteria included smoking, hypertension, hyperlipidemia (total cholesterol/HDL ratio > 5) or family history of premature atherosclerosis. Cases were stable on combination antiretroviral therapy with plasma HIV-1 RNA <50 copies per milliliter. Using computer modeling, the arterial wall, lumen, and total vessel volumes were calculated for a 4-cm length of each carotid artery centered on the bifurcation. The wall/outer-wall ratio (W/OW), an index of vascular thickening, was compared between the groups. Results:Cases had a median CD4 cell count of 690 cells per microliter. Mean (±SD) age and 10-year Framingham coronary risk scores were similar for cases and controls (45.2 ± 9.7 years versus 46.9 ± 11.6 years and 3.97% ± 3.9% versus 3.72% ± 3.5%, respectively). W/OW was significantly increased in cases compared with controls (36.7% versus 32.5%, P < 0.0001); this was more marked in HIV-infected females. HIV status was significantly associated with increased W/OW after adjusting for age (P < 0.0001). No significant association between antiretroviral type and W/OW was found—W/OW lowered comparing abacavir to zidovudine (P = 0.038), but statistical model fits poorly. Conclusions:In a cohort of treated HIV-infected individuals with low measurable cardiovascular risk, we have observed evidence of premature subclinical atherosclerosis.

Automatic extraction of the left atrial anatomy from MR for atrial fibrillation ablation

This paper describes and evaluates methods to detect pulmonary vein drainages and create detailed vessel trees of each drainage from contrast-enhanced magnetic resonance angiography (MRA). This description of the drainage allow us to determine the highly complex left atrial anatomy in a qualitative and quantitative way. It is beneficial for planning atrial fibrillation ablation procedures. We conclude that our methods permit the creation of drainage trees for the detailed description of the atrial anatomy from cardiac MRA data.

Reproducibility of T1 mapping 11-heart beat MOLLI Sequence

Methods 15 healthy volunteers (31±5 years, 8 males) with no known medical conditions, on no medication, underwent CMR scans (Avanto, Siemens, 1.5T) on two separate attendances with an 11 heart beat MOLLI 5(3)3. Following frequency adjustment, native T1 maps were obtained twice on a basal and a mid-ventricular slice respectively. 15 mins following GBCA administration (0.1 mmol/kg, Gadobutrol, Bayer, Germany) both image planes were acquired again twice. Pixel-wise T1 maps were analyzed offline by 2 independent blinded operators. A Region Of Interest was manually drawn in the septum for myocardium and blood in native and post gad images as shown in fig 1.

A novel approach to phase-contrast velocity offset correction by in vivo high-SNR acquisitions

Background Baseline offset errors on phase-contrast velocity images can be corrected using stationary tissue, for example subtracting fitted corrections from the image (1). Although corrections are often curved over the FOV, 1st order (linear) fitting is typical. This may partly be due to low SNR of static tissue making higher-order fitting unreliable (2). Aim: To evaluate a new method acquiring additional high SNR velocity images specifically to improve offset correction.

Improved dynamic parallel imaging coil calibration method robust to respiratory motion with application to first-pass contrast-enhanced myocardial perfusion imaging.

To develop an accurate method of performing free‐breathing coil calibration for application to parallel imaging reconstructions of dynamic single‐shot datasets.

2014 Left ventricular ejection function and viability assessed by CMR in patients undergoing anterograde versus retrograde percutaneous coronary interventions for chronic total occlusion: a Ppe and post procedure study

Open Access Meeting abstract 2014 Left ventricular ejection function and viability assessed by CMR in patients undergoing anterograde versus retrograde percutaneous coronary interventions for chronic total occlusion: a Ppe and post procedure study Didier Locca*, Chiara Bucciarelli-Ducci, Giuseppe Ferrante, Peter Barlis, Peter Drivas, Agata Grasso, Sanjay K Prasad, Carlo Di Mario and Dudley J Pennell