Download VASC-ASL - Hitachi Medical Systems America, Inc.

VASC-ASL
Veins and Arteries Sans Contrast – Arterial Spin Labeling
EchelonTM Technology
The Value of Contrast-free MRA with VASC-ASL
How does VASC-ASL work?
VASC-ASL is a method for performing
high quality Magnetic Resonance Angiography (MRA) without the use of a contrast
agent.
Contrast free MRA techniques are an alternative for patients with compromised
renal function.
1. Subtraction method. Vessel image is acquired with a
bright blood BASG sequence. Then it is acquired a second
time with a selective IR pulse that labels or nulls inflowing blood. After subtraction, only the vessel remains with
high signal. Subtraction method is useful for suppression
of complex background tissue.
Selective IR pulse off
Selective IR pulse on
Blood
flow
Blood
flow
Selective IR
Imaging
slab
VASC-ASL Advantages:
• Provides a contrast-free MRA method
for patients with reduced renal function
• Reduces risk for all patients
• Less complicated workflow – no IV
prep required
• Reduces study expense
• Excellent depiction of renal arteries
and portal veins
• Choice of subtraction or unsubtracted
• methods to best suit anatomy of interest
Blood signal: High
Blood signal: Low
Sub
The blood signal in
the slab is high.
2. Unsubtracted method. Selective IR pulse is placed over
the imaging area extending past the outflow of the vessel.
Only the fresh blood flowing in creates a high signal. Provides less background tissue suppression than subtraction method, but scan time is faster.
Blood
flow
Imaging
slab
Selective IR pulse
Blood flowing into the
region has high signal
High quality MRA imaging without a contrast agent
Exquisite image quality with no
contrast agent.
This 35 FOV renal was scanned in six
minutes using the unsubtracted
method.
Respiratory gating is used to minimize
patient motion artifacts.
Case Study: Renal artery stenosis
The VASC-ASL non contrast image on the left clearly shows stenosis, along with post stenotic
dilation of the left renal artery. The finding confirms a conventional MRA of the same patient.
VASC-ASL presents less risk to the patient and provides for smoother technologist workflow
since no IV or injector is required.
Arterial or venous flow may be depicted depending on the location of the selective IR pulse. Here VASC-ASL is used to image
pulmonary arteries (left) and pulmonary veins (right).
VASC-ASL is excellent for imaging the hepatic portal vein
Hitachi Medical Systems America, Inc. 1959 Summit Commerce Park, Twinsburg, Ohio 44087 USA
Tel: 330.425.1313 800.800.3106 Fax: 330.425.1410 www.HitachiMed.com [email protected]
2010 All Rights Reserved. Printed in the U.S.A. 0510/2000/DM# 71327 v1
HitachiMed.com
800.800.3106