T1-weighting of Hahn echo-trains in the stray-field for deuterium: prospects for imaging using long echo-train summation

✍ Scribed by Edward W Randall; Teresa G Nunes; Geneviève Guillot; Philippe R Bodart

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 175 KB
• Volume: 14
• Category: Article
• ISSN: 0926-2040
• DOI: 10.1016/s0926-2040(99)00028-4

✦ Synopsis

Hahn-echoes have been observed in stray-field gradients of 37.5 Trm and 74.5 Trm for deuterium in heavy water in a number of forms: liquid, ice, and coordinated in solid copper sulfate and silica gel. In the diamagnetic samples, the Ž . application of many pulses ) 1000 or more in long pulse-trains produced many sustained echoes. This lengthening of T echo Ž . is caused by T -weighting of the components of the Hahn echo even in the absence of spin-locking . In contrast, for the 1 paramagnetic complex, the shortening of T greatly reduces T and only few echoes are obtained. A new protocol for 1 echo Ž . stray field imaging is suggested when T is long: long echo-train summation LETS . The observed magnetisation is much 1 greater for heavy ice than for heavy water because the line-width, and hence the thickness of the excited slice, is greater.