Multiple Sclerosis, 1 October 2002, vol. 8, no. 5,
Hickman S.; Barker G.; Molyneux P.; Miller D.
 NMR Research Unit, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
There is a large historical database of dual-echo conventional spin-echo (CSE) magnetic resonance images in multiple sclerosis (MS).
If new analysis techniques can be developed then this database could provide valuable information.
We have investigated a technique in which the late echo of a dual-echo data set is subtracted from the corresponding early echoyielding images, which appear qualitatively similar to T1-weighted images.
This study investigated whether the hypointense lesions on the 'pseudo-T1' images (created as described above) were related to hypointense lesions on conventional T1-weighted images.
The hypointense lesion areas were measured by a blinded observer using a computer-assisted contouring technique applied to pseudo-T1 and T1-weighted CSE images obtained from 17 patients with secondary progressive MS (SPMS).
The mean hypointense lesion area from T1-weighted images was 2218- 2072 mm2, compared to 1426-1353 mm2 from pseudo-T1 images (p = 0.008).
There was, however, a strong correlation between the values obtained from the two sets of images (r = 0.93, p < 0.001).
The strong correlation between the values obtained from the two sets of images suggests that pseudo-T1 images may be useful to investigate a subgroup of more destructive lesions in MS from historical databases and in future prospective studies when imaging time is limited.