Note: This copy is for your personal non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, contact us at www.rsna.org/rsnarights. VASCULAR/INTERVENTIONAL RADIOLOGY 901 Modern Perforator Flap Imaging with High-Resolution Blood Pool MR Angiography 1 Advances in microsurgical techniques have improved autologous reconstructions by providing new donor site options while decreas- ing donor site morbidity. Various preoperative imaging modalities have been studied to assess the relevant vascular anatomic struc- tures, with magnetic resonance (MR) angiography traditionally lagging behind computed tomography (CT) with respect to spatial resolution. Blood pool MR angiography with gadofosveset triso- dium, a gadolinium-based contrast agent with extended intravas- cular retention, has allowed longer multiplanar acquisitions with resultant voxel sizes similar to or smaller than those of CT and with improved signal-to-noise ratio and soft-tissue contrast while main- taining the ability to depict flow with time-resolved imaging. The resultant vascular detail enables precise evaluation of the relevant vascular anatomic structures, including the vessel course, size, and branching pattern, as well as the venous arborization pattern. In ad- dition, any architectural distortion, vessel alteration, or injury from prior surgery can be depicted. The reporting radiologist should be aware of pertinent and incidental findings relevant to the planned surgery and the patient’s disease so that he or she can assist the microsurgeon in flap design as a member of the multidisciplinary team. Given the lack of ionizing radiation exposure in patients who often have an elevated body mass index, high-spatial-resolution blood pool MR angiography has become the imaging reference standard for the preoperative assessment of perforator flap vascular and soft-tissue morphology in our practice. © RSNA, 2015 • radiographics.rsna.org Alexander C. Kagen, MD Rydhwana Hossain, MD Erez Dayan, MD Soumya Maddula, BA William Samson, MD Joseph Dayan, MD Mark L. Smith, MD RadioGraphics 2015; 35:901–915 Published online 10.1148/rg.2015140133 Content Codes: 1 From the Departments of Radiology (A.C.K.) and Plastic and Reconstructive Surgery (W.S.), Mount Sinai Roosevelt Hospital, 4th Floor Ra- diology Administration, 4C-12, 1000 10th Ave, New York, NY 10019; Departments of Radi- ology (R.H.) and Plastic and Reconstructive Surgery (E.D., J.D., M.L.S.), Mount Sinai Beth Israel Hospital, New York, NY; Departments of Radiology, Mount Sinai St. Luke’s Hospital and Icahn School of Medicine, New York, NY (A.C.K.); and Albert Einstein College of Medi- cine, Bronx, NY (S.M.). Presented as an educa- tion exhibit at the 2013 RSNA Annual Meeting. Received April 2, 2014; revision requested July 21 and received August 13; accepted August 14. For this journal-based SA-CME activity, the author A.C.K. has provided disclosures (see p 914); all other authors, the editor, and the re- viewers have disclosed no relevant relationships. Address correspondence to A.C.K. (e-mail: akagen@chpnet.org). After completing this journal-based SA-CME activity, participants will be able to: ■ Identify common donor flap anatomic structures used in reconstructive micro- surgery. ■ Explain the advantages of using high- resolution blood pool MR angiography for preoperative perforator flap assess- ment. ■ Recognize some common pitfalls and relevant incidental findings when imag- ing perforator flaps. See www.rsna.org/education/search/RG. SA-CME LEARNING OBJECTIVES Introduction Microsurgical autologous flap reconstruction involves the dissec- tion and transfer of tissue perfused by small vessels to a distant site where the tissue is revascularized with the use of microscopic magnification. Microsurgical technique has evolved to allow the isolation of smaller perforating vessels from the surrounding tissue, thereby minimizing morbidity at the donor site. These techniques for perforator dissection have also been applied to nonmicrovas- cular flaps with pedicles, to decrease morbidity at the donor site in regional flap reconstruction. Preoperative imaging is extremely use- ful for identifying these small vessels and any potential aberrations in normal anatomic structures that might affect the reconstructive approach (1,2). Surgical flap design is a complex process that requires an in-depth knowledge of anatomy, an understanding of the patient’s preference with regard to the donor site, and consideration of variant vascular anatomic structures and postsurgical changes that may affect flap