<Page> EXHIBIT 21.1 List of Subsidiaries of MQ Associates, Inc. <Table> <Caption> EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS STATE OR OTHER JURISDICTION OF INCORPORATION OF CHARTER ORGANIZATION MedQuest, Inc. Delaware Anderson Diagnostic Imaging, Inc. South Carolina Asheville Open MRI, Inc. North Carolina BioImaging at Charlotte, Inc. Tennessee BioImaging of Cool Springs, Inc. Tennessee BioImaging at Harding, Inc. Tennessee Cabarrus Diagnostic Imaging, Inc. North Carolina Cape Fear Diagnostic Imaging, Inc. North Carolina Carolina Imaging, Inc. of Fayetteville North Carolina Carolinas Diagnostic Imaging, Inc. South Carolina Chapel Hill Diagnostic Imaging, Inc. North Carolina Chattanooga Diagnostic Imaging, Inc. Tennessee Dothan Diagnostic Imaging, Inc. Alabama Florida Diagnostic Imaging Center, Inc. Florida Grove Diagnostic Imaging Center, Inc. California Imaging Services of Alabama, Inc. Alabama Kansas Diagnostic Imaging, Inc. Kansas Kenosha Diagnostic Imaging, Inc. Wisconsin Lexington Open MRI, Inc. South Carolina Mecklenburg Open MRI, Inc. North Carolina MedQuest Associates, Inc. South Carolina Missouri Imaging, Inc. Missouri Mobile Open MRI, Inc. Alabama Northeast Columbia Diagnostic Imaging, Inc. South Carolina Occupational Solutions, Inc. Georgia Open MRI of Georgia, Inc. Georgia Open MRI & Imaging of Georgia, Inc. Georgia Open MRI & Imaging of Richmond, Inc. Virginia Palmetto Imaging, Inc. South Carolina Phoenix Diagnostic Imaging, Inc. Arizona Piedmont Imaging, Inc. (Forsyth) North Carolina Piedmont Imaging, Inc. (Spartanburg) South Carolina South Carolina Diagnostic Imaging, Inc. South Carolina Sun View Holdings, Inc. South Carolina Texas Imaging Services of El Paso, Inc. Texas Triad Imaging, Inc. North Carolina Tyson's Corner Diagnostic Imaging, Inc. Virginia Vienna Diagnostic Imaging, Inc. Virginia Virginia Diagnostic Imaging, Inc. Virginia Wisconsin Diagnostic Imaging, Inc. Wisconsin Athens MRI, LLC Georgia Bridgeton MRI and Imaging Center, LLC Missouri Brunswick Diagnostic Imaging, LLC Georgia Buckhead Diagnostic Imaging, LLC Georgia Cape Imaging, L.L.C. Missouri </Table> <Page> <Table> <Caption> EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS STATE OR OTHER JURISDICTION OF INCORPORATION OF CHARTER ORGANIZATION Carolina Medical Imaging, LLC South Carolina Clayton Open MRI, LLC Missouri Coastal Imaging, L.L.C. North Carolina Cumming Diagnostic Imaging, LLC Georgia Diagnostic Imaging of Atlanta, LLC Georgia Diagnostic Imaging of Georgia, LLC Georgia Diagnostic Imaging of Hiram, LLC Georgia Diagnostic Imaging of Marietta, LLC Georgia Duluth Diagnostic Imaging, LLC Georgia Duluth CT Center, LLC Georgia Durham Diagnostic Imaging, LLC North Carolina East Cooper Diagnostic Imaging, LLC South Carolina Farmfield Diagnostic Imaging, LLC South Carolina Fort Mill Diagnostic Imaging, LLC South Carolina Hapeville Diagnostic Imaging, LLC Georgia Imaging Center of Central Georgia, LLC Georgia Jacksonville Diagnostic Imaging, LLC North Carolina Kirkwood MRI and Imaging Center, LLC Missouri Midtown Diagnostic Imaging, LLC Georgia Montgomery Open MRI, LLC Alabama Norwood Diagnostic Imaging, LLC Alabama Open MRI & Imaging of Conyers, LLC Georgia Open MRI & Imaging of Albany, LLC Georgia Open MRI & Imaging of Athens, LLC Georgia Open MRI & Imaging of Douglasville, LLC Georgia Open MRI of Atlanta, LLC Georgia Open MRI of Central Georgia, LLC Georgia Open MRI & Imaging of DeKalb, LLC Georgia Open MRI & Imaging of North Fulton, LLC Georgia Open MRI & Imaging of Macon, LLC Georgia Open MRI of Myrtle Beach, LLC South Carolina Open MRI & Imaging of N.E. Georgia, LLC Georgia Open MRI & Imaging of Snellville, LLC Georgia Open MRI & Imaging of Florence, LLC South Carolina Open MRI of Simpsonville, LLC South Carolina Open MRI & Imaging of Richmond, LLC Virginia Richmond West End Diagnostic Imaging, LLC Virginia Simpsonville Open MRI, LLC South Carolina St. Peters MRI & Imaging Center, LLC Missouri Town & Country Open MRI, LLC Missouri Tricom Diagnostic Imaging, LLC South Carolina West Ashley Diagnostic Imaging, LLC South Carolina West Paces Diagnostic Imaging, LLC Georgia Woodstock Diagnostic Imaging, LLC Georgia </Table>