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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