Abdominal MRI in the Emergency Setting

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1 Abdominal MRI in the Emergency Setting Ivan Pedrosa, MD, FSCBTMR UT Southwestern Medical Center. Dallas, TX

2 MRI Use in Tertiary Care ED (01-05) 391% increase in ED MRI (1,900 exams) 38.9% total MRI increase (62,823 exams) 9% decrease in patient ED volume Peak times (4PM-11PM) Rankey D et al. Acad Radiol 2008

3 MRI Utilization in Tertiary Care Ahn S et al. PLoS One 2014

4 Goals Opportunities for Abdominal MRI in ED Reduce Radiation Improve diagnostic performance Optimize Cost Challenges Logistical Technical Abdominal Imaging in ER. Raja et al. Int J Emerg Med 2011

5 Reduce Radiation Indications with frequent visits to the ED requiring Abdomen/Pelvis CT Vulnerable Populations: children, pregnant patients, young adults

6 Acute Appendicitis: Meta-analysis Children 1 Sens 96.5% (95% CI %) Spec 96.1 (95% CI %) PPV 92% (95% CI %) NPV 98.3 (95% CI %) Pregnancy 2 Sens 94% (95% CI 87-98%) Spec 97% (95% CI 96-98%) 1 Moore MM et al. Pediatric Radiol Duke E et al. AJR 2016

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8 Repplinger et al JACR 2016 (Courtesy ScoJ Reeder) Acute Appendicitis 1 % pts with appy with imaging No Imaging CT US MRI CT & US

9 Repplinger et al JACR 2016 (Courtesy ScoJ Reeder) Acute Appy MRI: General Population Sensi&vity = 0.97 ( ) Specificity = 0.96 ( )

10 What limits Its Adoption Then? Cost: MRI>CT>US ED Workflow: Time from order-to-perform Efficient safety screening 24/7 MRI tech coverage (4-11PM peak) ED Workflow: Time from perform-tointerpreted 24/7 Radiology expertise

11 Patient-centered Outcomes Research Clinical Outcomes in Pregnancy 1 Negative Laparotomy rate 30% (7%) Perforation rate 21% Alternative Diagnosis 2 Similar to CT: % (lower in some refs) Better in young women? 1 Pedrosa I et al. Radiology Duke E et al. AJR 2016

12 Since 2004 Lack of comparison of US and MRI No prospective data!!

13 Prospective, excellent results Not proposed as a replacement of US - useful in specific clinical scenarios? No additional data!!

14 Ananthakrishnan et al. Am J Gastroenterol 2010

15 Inflammatory Bowel Disease in the ED Number of ED Visits (x1,000) All IBD patients Crohn s Disease Ulcerative Colitis Ananthakrishnan et al. Am J Gastroenterol 2010

16 Inflammatory Bowel Disease Average diagnosis is 27 years Silverstein MD, et al. Gastroenterology Chatu et al. Int J Clin Pract. 2013

17 High-dose Radiation in IBD patients Meta-analysis: 8 studies (3,512 pts) 1/10 pts >50 msv: Crohn s (11%) vs UC (2%) Most from CT (replace SBFT in U.S.) Risk factors: corticosteroids & IBD-related surgery Out-patient vs In-patient: not analized Chatu et al. Aliment Pharmacol Ther. 2012

18 CT use in ED: IBD 648 pts ( ) P value CT in ED 47% 78% Hospital Admission 68% 71% 0.06 Kerner et al. Inflamm Bowel Dis 2013

19 Can Clinical Decision Rules Identify Patients for Whom Imaging Can Be Safely Avoided? Erythrocyte sedimentation rate +5 x (ESR) and C-reactive protein (CRP) < 10 mg/dl Reduction in CT for Crohn s Disease by half Govani et al. Clin Gastroenterol Hepatol 2014 Ann Emerg Med (in press)

20 MRE vs Clinical Evaluation in Crohn s Per Bowel Segment Terminal Ileum Per Patient Crohn s activity index Sensitivity 59% 89% 91% 92% Specificity 67% 67% 71% 28% Koh et al. AJR 2001

21 MR Enterography (MRE) Protocol Oral prep x 45 min MR Fluoro x 5 min Cor T2 SSh Cor T2 Fat Sat SSh Axial SSFP Cor 3D T1 SPGR pre Glucagon Cor 3D T1 SPGR x2: del art & port Axial 3D T1 SPGR x2: abd & pelvis ] Fixed strictures Wall edema/thickness/ abscesses/phlegmon Fistulas/strictures/vasculature ] Disease activity/ abscesses/ phlegmon

22 MR Enterography (MRE) Protocol Oral prep x 45 min MR Fluoro x 5 min Cor T2 SSh Cor T2 Fat Sat SSh Axial SSFP Cor 3D T1 SPGR pre Cor 3D T1 SPGR x2: del art & port Axial 3D T1 SPGR x2: abd & pelvis Is This All Necessary in the ED SeUng? T2W MRE SSFSE vs Surgery Sensi`vity Bowel 90% stenosis: for small bowel Sens 95%; obstruc`on Spec 95% Abscess: 73% for Level Sens 92%; of obstruc`on Spec 90% Pozza et al. J Gastroenterol Surg % for Cause of obstruc`on Regan et al. AJR 1998

23 What Modalities are Most Appropriate for Imaging Inflammatory Bowel Disease in the ED??? Ann Emerg Med (in press)

24 Abdominal pain in Pregnant Pt with Crohns disease Ax and Cor T2-W SSSFE

25 Crohn s Disease in ED Clinical Decision Tools Admit 5 min MRI Discharge Full-protocol MRE Obstruc`on Abscess/phlegmon Perfora`on? OPT GI F/U

26 Right Upper Quadrant Pain U.S. National Trends Admissions from ED for RUQ Pain (789.01) Charges for RUQ Pain (789.01) hjp://hcupnet.ahrq.gov/

27 Co>on P, et al., Am J Gastro 2010

28 Compressed Sensing in MRCP 3D MRCP with 5% K-space sampling (17-fold acceleration) 20s breath-hold (CS) vs minutes Resp Trig. (standard) Chandarana et al. Radiology 2016 Superior image quality with CS 5-min MRCP Protocol in ED?

29 Imaging Trends in the BWH CT: fast increase Steady decline in imaging after 07 Raja et al. AJR 2014 Implementation of clinical decision support tools (CDS)

30 We Must Address the Challenges Technical: robustness in sick patients (motion) Logistical: Safety screening, MRI tech coverage, time to interpretation Cost: Long exams = $$$ Institutional resistance to lower cost, short exams

31 1. Clinical decision rules 2. Use of administrative data 3. Patient-centered outcomes research 4. Training, education, and competency 5. Knowledge translation and barriers to imaging optimization 6. Comparative effectiveness research in alternatives to traditional computed tomography use. Marin JR, Mills AM. Acad Emerg Med 2015

32 Compara`ve effec`veness research themes (with funding rank ajributed by conference par`cipants) 1. Non-trauma torso CT in ED settings : alternatives to CTA? 2. ED-based trauma CT 3. Positives and negatives of CT in the ED 4. Alternate CT protocols in ED settings 5. Pediatric CT in ED settings: rapid head MRI be used instead of CT? Gunn ML et al. Emerg Radiol (in press, Courtesy Aaron Sodickson, MD)

33 Conclusion Adoption of Abdominal MRI has been slow Growing evidence of excellent MRI performance in several diseases Other logistical and cost-related factors come into place that need to be addressed Development of diagnostic algorithms based on Clinical Decision Support tools is critical for the successful adoption of MRI

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