Interventional Radiology


interventional section 4



The mission of the Interventional Radiology Division at the University of Colorado Anschutz Medical Campus is to provide the best care to our patients, using innovative techniques across highly diversified medical and surgical subspecialties. We ha​ve a deep commitment to trainee education at all levels, with a focus on developing future leaders in Interventional Radiology (IR).  We have aligned clinical, translational, and basic science research interests to support our mission of scientific inquiry and discovery.

Division Leadership & Faculty


mclennanGordon McLennan, MD

Section Chief

Vice Chair of Clinical Research


Leigh Casadaban

Leigh Casadaban, MD


Christopher Doe, MD

Integrated and Independent IR Residency Associate Program Director


Larissa Hosler, PA-C



Anne Kirkpatrick, PA-C


Kimi Kondo, DO 

Director of Medical Student Education



Sarah Langan, PA-C



Jonathan Lindquist, MD 

Director of IR Quality and Patient Safety

Medical Director, Interventional Radiology



Shelley Rio, NP, MS, RN


Paul Rochon, MD

Integrated and Independent IR Residency Program Director

Director, Noninvasive Vascular Imaging

Director, Diversity, Equity, and Inclusion

Co-Director, HHT Center of Excellence



  Premal Trivedi, MD, MSE

Director, Health Services Research       

Lisa Walker (2)

Lisa Walker, MD



George Zlotchenko, MD

Medical Director of Highlands Ranch Hospital

interventional section 1Follow us on Twitter! @ColoradoIR​ 


Patient Care

The IR section, which performs approximately 9,000 procedures each year, consists of nine fellowship-trained interventional and neuro interventional radiologists, and three dedicated mid-level providers.  The IR service provides formal consultative services and an inpatient admission service, for adults as well as pediatric patients at the Children’s Hospital of Colorado (also on the Anschutz Medical Campus).  In addition to performing the image-guided procedures, each IR physician runs a weekly outpatient clinic.  Finally, the IR section participates in several weekly multidisciplinary conferences and clinics on the Anschutz Medical Campus.

Research & Academics

The IR Division has an active and productive clinical, basic science, and translational research program, with significant intra- and extramural grant support.  The research enterprise is under the direction of Dr. Thor Johnson.  Specific areas of research include interventional oncology, portal hypertension management, intra/extracranial vascular malformation therapies, venous interventions, and hepatic transplant interventions.  IR faculty also hold many leadership positions in national and regional societies, including presidency in three major professional organizations, as well as serving on many university and hospital committees.

Selected Faculty Bibliography -- Trivedi PS, Brown MA, Rochon PJ, Ryu RK, Johnson DT. Gender Disparity in Inpatient Mortality After Transjugular Intrahepatic Portosystemic Shunt Creation in Patients Admitted With Hepatorenal Syndrome: A Nationwide Study. J Am Coll Radiol. 2020 Feb;17(2):231-237 -- Wadhwa V, Trivedi PS, Chatterjee K, Desai S, Ahmed O. Identifying Patient and Hospital Characteristics Resulting in Higher Use of Inferior Vena Cava Filters among Inpatients with Venous Thromboembolic Disease: Analysis of the 2014 Nationwide Inpatient Sample. J Vasc Interv Radiol. 2018 Aug;29(8):1206-1208    -- Lindquist J, Schramm K. Drug-Eluting Balloons and Drug-Eluting Stents in the Treatment of Peripheral Vascular Disease. Semin Intervent Radiol. 2018 Dec;35(5):443-452 -- Hoffmann JC, Singh A, Szaflarski D, Chick JFB, Azimov N, Mittal S, Flug J, Rochon PJ. Evaluating current and recent fellows' perceptions on the interventional radiology residency: Results of a United States survey. Diagn Interv Imaging. 2018 Jan;99(1):9-14. -- Goldman DT, Magnowski A, Rochon PJ, Bream PR Jr, Kondo KL, Peters G, Martin JG, Fischman AM. The State of Medical Student Teaching of Interventional Radiology: Implications for the Future. J Am Coll Radiol. 2018 Dec;15(12):1761-1764.

Ray CE, Edwards A, Smith MS, Leong S, Gipson M, Rochon PJ, Kondo K, Gupta R, Messersmith W, Purcell T, Durham JD. A meta-analysis of survival, complications, and RECIST response following chemotherapy-based transarterial therapy in patients with unresectable cholangiocarcinoma. J Vasc Interv Radiol 2013;25:58-62

Green TJ, Rochon PJ, Chang S, Ray CE, Brown A, Winston H, Shulman BC, Durham JD. Down staging HCC to within Milan criteria using Doxorubicin-eluting bead TACE. J Vasc Interv radiol 2013;24:1613-22

Smith, MS, Rase B, Kondo K, Woods A, Trotter J, Johnson S, Durham JD. Incarceration of abdominal hernias following transjugular intrahepatic portosystemic shunt (TIPS). J Vasc Interv radiol 2014;25:58-62. 

Hayashi PH, Ludkowski M, Forman LM, Osgood M, Johnson S, Kugelmas M, Trotter JF, Bak T, Wachs M, Kam I, Durham J,Everson GT. Hepatic artery chemoembolization for hepatocellular carcinoma in patients listed for liver transplantation. Am J Transplant. 2004 May;4:782-7.

Hayashi PH, Mao J, Slater K, Liao R, Durham JD, Carroll J, Everson GT, Kam I, Forman LM. Atrial Septal Perforation From TIPS Stent Migration. J Vasc Interv Radiol. 2004;15: 629-32.

Durham JD, Kumpe DA, Rothbarth LJ, Stiegmann GV. Dieulafoy disease: arteriographic findings and treatment. Radiology 1990; 174:937-941.

Kumpe DA, Zwerdlinger SC, Rothbarth LJ, Durham JD, Albrecht BH. Proximal fallopian tube occlusion: Diagnosis and treatment with transcervical fallopian tube catheterization. Radiology 1990;177:183–187.

Gipson MG, Kondo KL Management of lymphoceles after renal transplant: case report of a novel percutaneous image-guided treatment technique J Vasc Interv Radiol 2013;24:881-884

Christenson BM, Rochon P, Gipson M, Gupta R, Smith MT. Treatment of infrapopliteal arterial occlusive disease in critical limb ischemia Semin Intervent Radiol. 2014 Dec;31(4):370-4

Christenson BM, Gipson MG, Smith MT. Pelvic vascular malformations Semin Intervent Radiol. 2013 Dec;30(4):364-71

Gipson MG, Smith MT. Endovascular therapies for primary postpartum hemorrhage: techniques and outcomes Semin Intervent Radiol. 2013 Dec;30(4):333-9

Johnson, DT, et al., Proteomic changes associated with diabetes in the BB-DP rat. Am J Physiol Endocrinol Metab, 2009. 296(3): p. E422-32.

Johnson, DT, et al., Distribution of reported StarClose SE vascular closure device complications in the manufacturer and user facility device experience database. J Vasc Interv Radiol, 2013. 24(7): p. 10516.

Ryu RK Lewandowski RJ Optimizing the use of IVC filters in oncology patients: are all filters created equally? Semin Thromb Hemost 2014;40:401-06

Andreoli JM, Lewandowski RJ, Vogelzang RL, Ryu RK Comparison of complication rates associated with permanent and retrievable inferior vena cava filters: a review of the MAUDE database J Vasc Interv Radiol 2014;25:1181-85

Ryu RK, Parikh P, Lewandowski RJ, et al Optimizing IVC filter utilization: a prospective study of the impact of IR consultation J Am Coll Radiol 2012;9(9):657-660

Lewandowski RJ, Mulcahy MF, Kulik LM, Riaz A, Ryu RK et al Chemoembolization for hepatocellular carcinoma: comprehensive imaging and survival analysis in a 172-patient cohort Radiol 2010;255(3):955

Riaz A, Ryu RK et al Alpha-fetoprotein response after locoregional therapy for hepatocellular carcinoma: oncologic marker of radiologic response, progression, and survival J Clin Onc 2009;27:5734-5742

Scanlon T, Ryu RK Portal vein imaging and access for transjugular intrahepatic portosystemic shunts Tech Vasc Interv Radiol 2008;11:217-224

Cooper VF, Goodhartz LA, Nemcek AA Jr, and Ryu RK Radiology resident interpretations of on-call imaging studies: the incidence of major discrepancies Acad Radiol 2008;15:1198-1204

Mulcahy MF, Lewandowski RJ, Atassi B, Ryu RK, et al Safety and efficacy of Y90 radiotherapy for hepatocellular carcinoma with and without portal vein thrombosis Hepatol 2008;47:71-81

​Ryu RK, Sato KT, Lewandowski RJ, Kulik L, Mulcahy MF, Larson AC, Salem R, Omary RA.  Effect of C-arm Angiographic CT on Transcatheter Arterial Chemoembolization of Liver Tumors  J Vasc Interv Radiol 2007;18:1305-9

Timperman PE, Sichlau MJ, Ryu RK Greater energy delivery improves treatment success of endovenous laser treatment of incompetent saphenous veins J Vasc Interv Radiol 2004;15:1061-1063

interventional section 2Ryu RK, Siddiqi A, Omary RA, Chrisman HB, Nemcek Jr AA, et al  The delayed effects of uterine artery embolization on ovarian arterial perfusion and function  Am J Roentgenol 2003;181(1):89-92

Ryu RK, Durham JD, Krysl J, et al Role of TIPS as a bridge to transplantation in Budd-Chiari syndrome J Vasc Interv Radiol 1999;10:799-805

Ryu RK, Duke BJ, Brega KE, Coldwell DM  Percutaneous endoluminal stent placement for traumatic bilateral internal jugular vein occlusion J Vasc Interv Radiol 1997;8:359-362

Kondo KL, Swerdlow M. Medical Student Curriculum:  What Skills Do Residency Program Directors Believe Are Essential For Medical Students To Attain? Academic Radiology 2013 Mar; 20(3):263-71.

​​Straus CM, Webb EM, Kondo KL, Phillips AW, Naeger DM, Carrico CW, Herring W, Neutze JA, Haines GR, Dodd GD 3rd. Medical Student Radiology Education:  Summary and Recommendations From a National Survey of Medical School and Radiology Department Leadership. Journal of the American College of Radiology 2014 Jun;11(6):606-10.

​Rochon PJ, Reece TB. Endovascular approaches and perioperative consideration in acute aortic dissection. Semin Cardiothorac Vasc Anesth. 2011 Dec;15(4):141-62. 2219428d​

Ray CE Jr, Lorenz JM, Burke CT, Darcy MD, Fidelman N, Greene FL, Hohenwalter EJ, Kinney TB, Kolbeck KJ, Kostelic JK, Kouri BE, Nair AV, Owens CA, Rochon PJ, Rockey DC, Vatakencherry G. American College of Radiology Appropriateness Criteria radiologic manage​ment of benign and malignant biliary obstruction.  J Am Coll Radiol. 2013 Aug;10(8):567-74. 23763879

Green TJ, Rochon PJ, Chang S, Ray Jr CE, Winston H, Ruef R, Kriedler SM, Glueck DH, Shulman BC, Brown AC, Durham J. Downstaging patients with hepatocellular outside of milan criteria: strategies using drug-eluting bead chemoembolization. J Vasc Interv Radiol. 2013 Nov;24(11):1613-22. 24060436

Ray CE, Brown AC, Green TJ, Winston H, Kriedler SM, Glueck DH, Rochon PJ. Survival outcomes in patients with advanced hepatocellular carcinoma treated with drug-eluting bead chemoembolization. AJR Am J Roentgenol. 2015 Feb;204:440-447​