Qun He MEng, Presenter: Nothing to Disclose

Vipul Ravindra Sheth MD, PhD, Abstract Co-Author: Nothing to Disclose

Wen Hong MS, MD, Abstract Co-Author: Nothing to Disclose

Lanqing Ma, Abstract Co-Author: Nothing to Disclose

Jody Corey-Bloom, Abstract Co-Author: Nothing to Disclose

Graeme M. Bydder MBChB, Abstract Co-Author: Nothing to Disclose

Jiang Du PhD, Abstract Co-Author: Nothing to Disclose

Iron deposition may play a primary role in triggering inflammation and disease progression in multiple sclerosis (MS).  However, iron overload may reduce T2 so much that clinical MR sequences may not be able to detect it. In this study we aimed to assess iron deposition in the brain of patients with MS using inversion recovery prepared ultrashort echo time (IR-UTE) sequences at 3T.

We have implemented a 2D adiabatic inversion recovery prepared ultrashort echo time (IR-UTE) sequence (TE=8 μs) for high contrast imaging of iron deposition. An adiabatic inversion pulse was used to suppress the normal white matter and gray matter. Iron deposition tends to reduce T2* and T1, leading to high signal in regions with high iron concentration in IR-UTE imaging. We evaluated this technique on phantoms and patients with MS. The phantom contained 10 vials with different iron concentrations (0.5 to 60 mM). A TR of 750 ms and a TI of 250 ms were used for IR-UTE imaging of the iron phantom. Following the phantom study, 5 MS patients were recruited. They were studied with the following parameters: FOV=24 cm, slice thickness=5 mm, bandwidth=125 kHz, flip angle = 60°, TR = 1000 ms, TI = 330 ms, TE = 8 μs/2.2 ms, sampling points=191, projections=131, reconstruction matrix=256X256, scan time=4.4 min.

The phantom study shows that the conventional clinical IR-FSE sequence provides high contrast images of iron deposition in concentrations up to 2 mM, IR based gradient echo sequences, such as MP-RAGE can generate high contrast images of iron deposition in concentrations up to 5 mM, while the IR-UTE sequence provides high contrast images of iron deposition in concentrations up to 20 mM. The in vivo study shows that the IR-UTE sequence is capable of detecting iron deposition in MS patients. In the two MS patients shown in Figure 1, one patient shows near zero signal in the thalamus while the other shows high signal in the thalamus consistent with increased iron deposition.

The preliminary results show that the IR-UTE sequence can generate high contrast images of iron deposition in concentrations up to 20 mM in phantom studies. This sequence is also capable of high contrast imaging of iron deposition in the brain of patients with MS using a clinical 3T scanner.

High contrast imaging of iron deposition may significantly advance the study of neuro-degenerative diseases including MS.

He, Q, Sheth, V, Hong, W, Ma, L, Corey-Bloom, J, Bydder, G, Du, J, Assessment of Iron Deposition in the Brain in Multiple Sclerosis Using Ultrashort Echo Time (UTE) Sequences.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14008406.html