Real-time Imaging in case of Atrial Fibrillation

Real-time imaging:in case of atrial fibrillation

U.S. Department of

Health and Human

Services

National Institutesof Health

National Heart, Lung,and Blood Institute

Peter Kellman, Ph.D.

Disclosures

I have no financial relationships to disclose.

- and -

I will discuss the following off label use in my presentation:

Use of contrast agent for late enhancement imaging

Peter Kellman, Ph.D., NHLBI/NIH

144x256 matrix -> 1.9x1.4 mm2

8 HB breath-hold (incl. 1 discard)

(24.5 ms)

undersampling with net acceleration = 2.4

Beat

fully

sampled

reference

data

under-

sampled

data

Segmented Breath-held AcquisitionTypical Protocol

beat 1

beat 2

beat 3

Subject with atrial fibrillation:breath-held segmented, retro-gated cine

144x256 matrix

1.9x1.4 mm2

24.5 ms

Parallel imaging factor 2.4

8 HB breath-hold

discard

Subject with atrial fibrillation:breath-held segmented, retro-gated cine

discard

144x256 matrix

1.9x1.4 mm2

24.5 ms

Parallel imaging factor 2.4

8 HB breath-hold

~ 17.4 frames

(57.5 ms)

uniform undersampling with acceleration = 4

92x192 matrix -> 2.9x1.9 mm2

under-

sampled

data

Real-time Free Breathing AcquisitionTypical protocol with parallel imaging

Subject with atrial fibrillation:real-time free-breathing cine

parallel imaging factor 4

92x192 matrix

2.9x1.9 mm2

57.5 ms

Subject with atrial fibrillation:real-time free-breathing cine

Pseudo m-mode

~ 32 frames

(31.4 ms)

partial

Fourier

acquisition

“random” variable density undersampling with net acceleration = 9.4

120x192 matrix -> 2.3x1.9 mm2

Real-time Free Breathing AcquisitionCompressed sensing protocol

M Schmidt, O Ekinci, J Liu, A Lefebvre, MS Nadar, E Mueller, MO Zenge. “Novel highlyaccelerated real-time CINE-MRI …”. J Cardiovascular Magnetic Resonance 2013,15(Suppl 1):P36. (based on SIEMENS CV_Sparse WIP implementation)

Subject with atrial fibrillation:real-time free-breathing cine

Sparse sampled, compressed sensing reconstruction

120x192 matrix

2.3x1.9 mm2

31.4 ms

Single heartbeat late enhancement

•Rapid, multi-slice acquisition

•Arrhythmia insensitive

•Free-breathing acquisition

Huber A, et al., Investigative Radiology. 2006 Feb;41(2):148-53.

Huber A, et al., AJR. 2006 Mar;186(3):627-33.

Sievers B, et al., Circulation. 2007 Jan 16;115(2):236-44.

inversion

imagereadout

Kellman P, et al., MRM. 2004 Feb;51(2):408-12.

conventional

segmented with

poor breath-hold

single-shot

free breathing

Free breathing late enhancement

accelerated

single shotacquisition

respiratorymotioncorrection

averaging

raw

motion corrected

Full FOV

zoom

SENSE rate 2

Kellman P, et al., MRM. 2004 Feb;51(2):408-12.

Ledesma-Carbayo MJ, et al., JMRI. 2007. Jul; 26(1):184-190

Conventionl

IR-turboFLASH

breath-held

accelerated single-shot

IR-trueFISP

free-breathing

single frame

16 HB

single frame

2 HB

8 averages

16 HB

motion

corrected

same acquisition time

Respiratory Motion Corrected Averaging:

Selective averaging between 25-50% of “best”frames effectively mitigates thru plane motion

Rate 3 with 256x144 matrix

motion corrected

average

single heart beat

images

motion corrected

Subject in atrial fibrillationPSIR LGE

motion

corrected

average

single

heart beat

images

motion

corrected

Single-shot fat water separated imaging

motion

corrected

average

single

heart beat

images

motion

corrected

water

fat

1 2 3 M

  

N-echoes per PE line

Single shot, Rate = 3 parallel imaging

   (multiple repetitions)   

Single-shot fat water separated imaging

motion

corrected

average

single

heart beat

images

motion

corrected

water

fat

Review

•Free-breathing real-time cine function

•parallel imaging

•compressed sensing

•Free-breathing PSIR LGE

•accelerated, single shot

•respiratory motion corrected

•selective averaging

•Free-breathing Fat water separated imaging

•Dark blood prepared or PSIR LGE

•Fusion of images with ECG signals