Blind detection of vascular sources and territories using random vessel encoded arterial spin labeling

Abstract

Randomly encoded VEASL provides data that allows for blind detection of source vessels. This method simplifies the VEASL prescription process and allows for efficient detection of atypical or collateral circulation.

Quantitative Assessment of External Carotid Artery Territory Supply with Modified Vessel-Encoded Arterial Spin-Labeling

“…However, the geometric confounders such as vascular curvature could interfere with the labeling plane. In contrast, VE-ASL, as an alternative approach for vessel differentiation, relying only on the distance between arteries determined by vascular anatomies, 20,24 is demonstrated to be able to significantly improve vessel discrimination with the corrections of vessel-specific labeling efficiencies. In this study, the developed method modifies the encoding scheme of VE-ASL, to make it possible to quantitatively depict not only internal but also external carotid territory maps.…”

“…With perfect tagging efficiency, the modified encoding (A) and decoding (A ϩ ) matrices for this 4-vessel separation were the following: used as three 2-vessel encoding steps (eg, the third and fourth encoding cycles are used as 1 encoding step to distinguish the perfusion territory of the right ICA from that in the left ICA by alternatively placing 1 of these 2 vessels in the tag condition). The relative tagging efficiency for each vessel was measured directly from the experimental data 20,24 and was used in the reconstruction of the modified encoding matrix to compensate for the calculated deviation caused by various geometry and flow velocity of the vessels of interest. As shown in Fig 2 (center), the tagging efficiencies of vessels were measured per each encoding step (2 encoding cycles).…”

Arterial spin labeling: its time is now

“…In this issue alone, we see a paper on an innovative approach to mixing continuous and pulsed ASL [3], an exploration of the challenges of pseudo-continuous labeling in humans at 7 Tesla [4] and an investigation into unintended effects of pulses to shape the labeling bolus [5]. The exciting and exploding area of vessel-selective labeling to map perfusion territories is represented here by the New Concept article on random vessel encoding [6].A key issue restricting the reliability of ASL studies is the effect of motion and other instabilities on noise and artifacts in ASL. The successful approach of background suppression [7,8] is emphasized in the article of Maleki et al [9], where suppression is optimized and used to image blood flow to the eye.…”

“…In this issue alone, we see a paper on an innovative approach to mixing continuous and pulsed ASL [3], an exploration of the challenges of pseudo-continuous labeling in humans at 7 Tesla [4] and an investigation into unintended effects of pulses to shape the labeling bolus [5]. The exciting and exploding area of vessel-selective labeling to map perfusion territories is represented here by the New Concept article on random vessel encoding [6].…”

“…As we have seen in the article by Wong and Guo [6], it can provide information on which vessel is the source of the blood flow. But beyond that, ASL can be used as a technique for angiography [24].…”