MEDIASTINUM, CHEST WALL, AND DIAPHRAGM S103 Imaging of Diaphrag- matic Injury: A Diagnos- tic Challenge? 1 LEARNING OBJECTIVES FOR TEST 5 After reading this article and taking the test, the reader will be able to:  Recognize the vari- ous signs of dia- phragmatic rupture at chest radiography, CT, and MR imag- ing.  List the most spe- cific signs of right and left diaphrag- matic ruptures.  Discuss the advan- tages and pitfalls of CT, especially multi- section CT. Sandrine Iochum, MD ● Thomas Ludig, MD ● Fre ´de ´ric Walter, MD Hugues Sebbag, MD ● Gilles Grosdidier, MD ● Alain G. Blum, MD Diaphragmatic injuries occur in 0.8%– 8% of patients after blunt trauma. Although the diagnosis may be obvious at standard chest radi- ography or computed tomography (CT) in most situations, some more subtle signs require careful analysis of CT images and examination with magnetic resonance (MR) imaging in some specific situations. Each method of imaging evaluation has advantages and pitfalls accord- ing to the type of diaphragmatic rupture. MR imaging with breath-hold acquisition permits good visualization of diaphragmatic abnormalities, but this technique cannot be performed in emergency situations. Be- cause of a dramatic reduction in motion and beam-hardening artifacts and significant improvement of spatial resolution, especially along the z axis, helical CT and multisection CT allow better demonstration of the most subtle signs, such as a focal indentation of the liver or a right- sided collar sign. In addition, helical CT and multisection CT are use- ful tools in the evaluation of patients with multiple traumatic injuries. © RSNA, 2002 Index terms: Diaphragm, injuries, 66.4124, 795.411 ● Diaphragm, rupture, 66.4124, 795.411 ● Trauma, 66.4124, 795.411 RadioGraphics 2002; 22:S103–S118 1 From the Department of Radiology “Imagerie Guilloz” (S.I., T.L., F.W., A.G.B.) and Department of Surgery (H.S., G.G.), Ho ˆ pital Central, 29 Avenue de Lattre de Tassigny, 54035 Nancy, France. Presented as an education exhibit at the 2001 RSNA scientific assembly. Received February 27, 2002; revision requested April 1; final revision received June 14; accepted June 19. Address correspondence to S.I. (e-mail: s.iochum@chu-nancy.fr). © RSNA, 2002 CME FEATURE See accompanying test at http:// www.rsna.org /education /rg_cme.html RadioGraphics See the commentary by Ko and Primack.