MRI of the Acute Abdomen: Cost-effective use for the

MRI of the Acute Abdomen: Cost-effective use for the

MRI of the Acute Abdomen:
Cost-effective use for the
Emergency Room Patient
Diego R. Mar,n, M.D., Ph.D. The Cosden Professor and Chairman Department of Medical Imaging University of Arizona College of Medicine Tucson dmartin@radiology.arizona.edu
Emergency Room Care
Ø ED utilization of
healthcare has increased
significantly across the
United States
Ø 1996: 90.3 million ED visits
Ø 2006: 119.2 million ED
visits
Ø Increase of 32%
Ø Imaging ordered at 44% of
all visits
Ø CT ordered at 11.6% of
visits
Pitts, S. R., R. W. Niska, et al. (2008). "National Hospital Ambulatory Medical
Care Survey: 2006 emergency department summary." Natl Health Stat
Report(7): 1-38.
MRI for Acute
Abdominal Pain
Proposed Advantages
Ø Reduce radiation exposure in young patients
Ø Increase ED throughput (no oral or IV contrast)
Ø Decrease total no. of tests (XR + US + CT)
Ø Increase value (Outcome / Cost)
Strategy
Ø Patients <40yo with acute abdominal pain
(excluding renal calculus)
Ø Outcomes monitored (including d/c patients)
Cor T2
Ax T2
T1W 3D GRE FS
(Dixon)
Cor T2 FS
Sag T2
Ax T2 FS
Out of phase
(Dixon)
Sag T2 FS
SSFP
MRCP
In phase (Dixon)
Fat suppressed 3D
T1W (Dixon- Water
only)
3D T1W Dual echo
GRE
(Dixon- In and opposed
phase)
-Blood products
-Proteinaceous
material
-Fat (loss of signal on
opposed phase)
-Iron (loss of signal on
in phase)
T2W (motion resistant)
-Assessment of fluid
containing structures
-Organ morphology
T2W (motion resistant)
with
fat saturation
-Acute inflammation (itis sequence)
-Fat (dermoid, lipoma)
True FISP (motion
resistant)
MRCP
-Vascular analysis
(noncontrast)
-Secondary analysis of
fluid containing
structures
-Bile ducts
-Fluid containing
structures
MRI Interpretation Strategy
T2-weighted images without fat saturation
Ø Coronal, sagittal and axial
ANATOMY
T2-weighted images with fat saturation
(SPAIR technique)
Ø Coronal, sagittal and axial
INFLAMMATION
18 yo F, acute appendicitis
Ax T2
Ax T2 FS
34 yo F, pregnant, RLQ pain from
appendicitis
28 yo F, pregnant, RLQ pain from
ovarian torsion
MRI Interpretation Strategy
Unenhanced 3D GRE Fat-Suppressed (VIBE,
LAVA, THRIVE)
Blood Products
Hemorrhagic ovarian cyst
73 yo M, dropping H&H
A Cross-Section of Cases Showing
An Array of Disease Processes
Spanning GI and Non-GI Etiologies
25 yo M with RLQ pain
25 yo M with RLQ pain
from acute appendicitis
15 yo M, diffuse abdominal pain
15 yo M, diffuse abdominal from
perforated appendicitis
9 yo male, RLQ pain from
appendicitis
22y M: Abdominal Pain
Time: 10:02 am
22y M: Abdominal Pain
Enteritis
Time: 11:50 am
Time: 10:02 am
19 yo M, recurrent RLQ pain
Negative Meckel scan
Meckel’s diverticulum
20y F with abdominal pain
Pyelonephritis
66 yo F, acute appendicitis
Incidental Meckel’s Diverticulum
63y M, LLQ pain
Acute Diverticulitis
42 yo F, POD 11, fever & abdo pain
Bowel perforation and peritonitis
22 yo F, pelvic pain
22 yo F, tubo-ovarian abscess
20 yo F, pelvic pain
Pelvic inflammatory disease
27 yo F, RUQ pain
Acute cholecystitis
65 yo F, RUQ pain
Acute cholecystitis
15 yo F, RUQ pain
Acute hepatitis, with GB wall edema
26 yo F, LLQ pain
Ovarian torsion
Rectus muscle strain
40 yo M, abdominal pain
Pyelonephritis, bilateral
24 yo F
Pyelonephritis, hepatitis, LOV cyst
15 yo F, lower abdominal pain
Results
Ø Over 16 months (8.12 to 12.13)
Ø 234 patients mean age 21.8y
Ø 18% confirmed positive pathology
Ø MRI prospective findings
Ø 0 (0%) false negative
Ø 1 (0.4% or 5% in surgical cases) false positive
Precision of MRI –
Published results
Ø  Cobben L, Groot I, Kingma L, Coerkamp E, Puylaert J and Blickman J. A simple MRI
protocol in patients with clinically suspected appendicitis: results in 138 patients and
effect on outcome of appendectomy. Eur Radiol 2009; 19(5):1175-1183
Ø  Singh AK, Desai H and Novelline RA. Emergency MRI of acute pelvic pain: MR
protocol with no oral contrast. Emerg Radiol 2009; 16(2):133-141
Ø  Inci E, Hocaoglu E, Aydin S, et al. Efficiency of unenhanced MRI in the diagnosis of
acute appendicitis: comparison with Alvarado scoring system and histopathological
results. Eur J Radiol 2011; 80(2):253-258
Ø  Chabanova E, Balslev I, Achiam M, et al. Unenhanced MR Imaging in adults with
clinically suspected acute appendicitis. Eur J Radiol 2011; 79(2):206-210
Ø  Heverhagen JT, Pfestroff K, Heverhagen AE, Klose KJ, Kessler K and Sitter H.
Diagnostic accuracy of magnetic resonance imaging: a prospective evaluation of
patients with suspected appendicitis (diamond). J Magn Reson Imaging 2012; 35(3):
617-623
Ø  Johnson AK, Filippi CG, Andrews T, et al. Ultrafast 3-T MRI in the evaluation of
children with acute lower abdominal pain for the detection of appendicitis. AJR Am J
Roentgenol 2012; 198(6):1424-1430
Summary
Ø MRI provides competitive turnaround time
c/w CT for ED patients
Ø Increased sensitivity and specificity
Ø Utility dependent upon center availability
and skillsets available 24x7