Ihab Ayad

Four-dimensional, multiphase, steady-state imaging with contrast enhancement (MUSIC) in the heart: a feasibility study in children.

To develop a technique for high resolution, four‐dimensional (4D), multiphase, steady‐state imaging with contrast enhancement (MUSIC) in children with complex congenital heart disease.

Cardiovascular MRI with ferumoxytol

The practice of contrast-enhanced magnetic resonance angiography (CEMRA) has changed significantly in the span of a decade. Concerns regarding gadolinium (Gd)-associated nephrogenic systemic fibrosis in those with severely impaired renal function spurred developments in low-dose CEMRA and non-contrast MRA as well as efforts to seek alternative MR contrast agents. Originally developed for MR imaging use, ferumoxytol (an ultra-small superparamagnetic iron oxide nanoparticle), is currently approved by the US Food and Drug Administration for the treatment of iron deficiency anaemia in adults with renal disease. Since its clinical availability in 2009, there has been rising interest in the scientific and clinical use of ferumoxytol as an MR contrast agent. The unique physicochemical and pharmacokinetic properties of ferumoxytol, including its long intravascular half-life and high r1 relaxivity, support a spectrum of MRI applications beyond the scope of Gd-based contrast agents. Moreover, whereas Gd is not found in biological systems, iron is essential for normal metabolism, and nutritional iron deficiency poses major public health challenges worldwide. Once the carbohydrate shell of ferumoxytol is degraded, the elemental iron at its core is incorporated into the reticuloendothelial system. These considerations position ferumoxytol as a potential game changer in the field of CEMRA and MRI. In this paper, we aim to summarise our experience with the cardiovascular applications of ferumoxytol and provide a brief synopsis of ongoing investigations on ferumoxytol-enhanced MR applications.

MRI with ferumoxytol: A single center experience of safety across the age spectrum

To summarize our single‐center safety experience with the off‐label use of ferumoxytol for magnetic resonance imaging (MRI) and to compare the effects of ferumoxytol on monitored physiologic indices in patients under anesthesia with those of gadofosveset trisodium.

Airway evaluation of conjoined twins.

Case reports in the literature on conjoined twins discuss the difficulties with anesthesia and surgical separation; however, the role of airway endoscopy as a means of evaluating the respiratory tract has not been described. This case of thoraco-omphaloischiopagus laterally conjoined twins demonstrates the importance of videoendoscopic airway evaluation in the management of conjoined twins. Direct laryngoscopy and bronchoscopy was used to evaluate ventilator dependence and demonstrated tracheal anomalies that were partially responsible for difficulties with weaning and endotracheal tube placement. Knowledge of the airway anomalies assisted in ventilator management of the twins, and the neonatalogists were able to proceed with greater confidence because no surgically correctable airway obstruction was found. Direct laryngoscopy and bronchoscopy offer valuable information about thoracopagus conjoined twins and should be included in the preoperative evaluation of planned separation of conjoined twins, as well as being used for conjoined twins who are ventilator-dependent.

CMR in pediatric patients with congenital heart disease: comparison at 1.5T and at 3.0T

Author(s): Nguyen, Kim-Lien; Khan, Sarah; Moriarty, John; Mohajer, Kiyarash; Renella, Pierangelo; Satou, Gary; Ayad, Ihab; Patel, Swati; Boechat, Ines; Finn, J

Ferumoxytol across the age spectrum: a single center experience of safety

Background Ferumoxytol is used for parenteral iron therapy in patients with chronic kidney disease (CKD). Because of its uniquely powerful properties as an intravascular MR contrast agent, there is growing interest in the safety of ferumoxytol as a possible alternative to gadoliniumbased contrast agents in patients with CKD and in patients with congenital heart disease. We reviewed the frequency, type and severity of adverse reactions to ferumoxytol as an MRI contrast agent over a broad spectrum of ages and indications in a single center study.

4D Multiphase steady state imaging with contrast (MUSIC) enhancement using ferumoxytol: a new paradigm in pediatric congenital heart disease

Background CMR in children with congenital heart disease (CHD) often requires expert physician supervision and long examination times. Further, the complex anatomy may not be fully defined with limited 2D slices at the time of image acquisition and missing slice orientations cannot be reconstructed retrospectively. 4D MUSIC (1) generates isotropic high-resolution 3D images over multiple, independent cardiac phases without breath holding. We aim to evaluate this technique in patients with complex CHD and compare it to breathe held contrast enhanced MRA (CE-MRA) and 2D cine.

Contrast enhanced magnetic resonance angiography in children: initial experience at 3.0 Tesla

Background To assess the role of contrast enhanced magnetic resonance angiography (CEMRA) at 3.0T in pediatric patients referred for vascular evaluation, and to compare the technical and diagnostic performance of a clinically similar control group at 1.5T. Methods Fifty pediatric patients referred for vascular evaluation and without evidence of congenital heart disease, were evaluated with CEMRA. Thirty-five patients received 37 studies at 3.0T (age 0.4 -16.5 years, mean 5.8 ± 4.7 years. Fifteen patients received 16 studies at 1.5T (age 0.1 - 17.5 years, mean 5.8 ± 6.4 years). CEMRA was performed in three phases: arterial, early venous and late venous. Two independent observers analyzed the studies for image quality, artifacts and vessel definition. Results Overall image quality and vessel definition scores were higher at 3.0T than 1.5T in the arterial and early venous phase, however not the late venous phase. Overall

CEMRA in neonatal and pediatric congenital vascular diseases at 1.5T and 3.0T: comparison of an intravascular contrast agent (Gadofosveset) with an extracellular agent (Gadopentetate Dimeglumine)

Background The comparison of gadofosveset (Ablavar, Lantheus Medical) at a dose of 0.06 mmol /kg with gadopentetate dimeglumine (Magnevist, Bayer-Schering Inc.) at a dose of 0.2 mmol /kg for CEMRA in pediatric patients with complex congenital heart disease (CCHD) at 1.5T and 3.0T. Methods Twenty-eight pediatric patients with CCHD underwent CEMRA at 3.0T (n=16) or at 1.5T (n=12). Sixteen patients were imaged with gadofosveset; 9 at 3.0T (age 1.00 ± 1.58 months; weight 2.38 ± 1.13 kg) and 7 at 1.5T (age 8.00 ± 7.83 months; weight 5.06 ± 3.09 kg). Twelve patients were imaged with gadopentetate; 7 at 3.0T (age 1.00 ± 1.41 months; weight 3.02 ± 1.59 kg) and 5 at 1.5T (age 6.60 ± 8.62 months; weight 5.23 ± 2.93 kg). High resolution CEMRA was performed in two phases with strictly comparable imaging parameters, acquisition times and contrast agent infusion periods. Two independent observers scored the studies blindly on a four point scale for image quality, artifacts and vessel definition. Results At 3.0T, overall image quality (IQ) was good to excellent (3<=IQ<=4) in all patients and similar for gadofosveset and gadopentate. At 1.5T, IQ was also good to excellent, but higher for gadofosveset than gadopentetate. Cardiac motion or pulsation artifact was found in all studies at both field strengths but appeared more severe at 3.0T than 1.5T. Parallel acquisition artifact was noted in all studies at 3.0T, but in no studies at 1.5T. Vessel definition scores were higher for gadofosveset at both field strengths and both contrast phases, but lower for gadopentetate in the venous phase at 3.0T and in both phases at 1.5T. SNR and CNR was higher at 3.0T than 1.5T in the aortic arch, pulmonary artery, inferior vena cava and superior vena cava. SNR and CNR was higher for gadofosveset than gadopentetate during the arterial phase in the aortic arch and pulmonary artery. Conclusions

Cardiac MR imaging and MR angiography in pediatric congenital heart disease: a comparison between 1.5T and 3.0T

Author(s): Nguyen, KL; Khan, SN; Moriarty, J; Mohajer, K; Renella, P; Satou, G; Ayad, I; Patel, S; Boechat, I; Finn, P