SELECT     dbo_Asset_ImageSizes.id, dbo_Asset_ImageSizes.imagename, dbo_Asset_ImageSizes.imagewidth, dbo_Asset_ImageSizes.imageheight, 
                      dbo_Asset_ProductImages.itemnmbr, CASE [imageType] WHEN NULL THEN 1 CASE [itemnmbr] WHEN 'PCI1802' THEN 1 CASE ELSE 0 END
FROM         dbo_Asset_ImageSizes LEFT JOIN
                      dbo_Asset_ProductImages ON dbo_Asset_ImageSizes.id = dbo_Asset_ProductImages.imageType
WHERE     CASE [imageType] WHEN NULL THEN 1 CASE [itemnmbr] WHEN 'PCI1802' THEN 1 CASE ELSE 0 END = 1;