Web Forms :: Unable To Iterate ThroughIEnumerable And List?

i m new to asp.net 3.5 linq and dnt worked much on generics.i m using IEnumerable to return set of results.i m binding this IEnumerable type method directly to datagrid source then it works fine.But i dnt knw how to iterate through this collection??Same way i m using List<String> to return columns like this

public List<String> FindImageData()
{
List<String> lst = new List<string> { "" };
ISingleResult<Usp_Patient_Radiology_DisplayResult> imagedata = objimagedata.Usp_Patient_Radiology_Display(p_PatientID);
foreach (Usp_Patient_Radiology_DisplayResult h in imagedata)
{
string Imageid = Convert.ToString(h.ImageId);
string imagefilename = Convert.ToString(h.imagefilename);
string history = Convert.ToString(h.history);
string imagetype = Convert.ToString(h.imagetype);
string oprposundertaken = Convert.ToString(h.oprposundertaken);
string patientposition = Convert.ToString(h.patientposition);
string report = Convert.ToString(h.report);
string xfilmorn = Convert.ToString(h.xfilmorn);
lst = new List<String> {Imageid,imagefilename,history,oprposundertaken,patientposition,report,report,xfilmorn };
}
return lst;
}

but at front end again i dnt knw how to iterate through it.it returns only single row??

with dataset it was quiet easy to navigate but with linq to sql navigation through generic collections is tough.