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Diffusion-weighted magnetic resonance imaging in ileocolonic
Crohn’s disease
Juel
1
MA ,
Rafaelsen
2
S,
Nathan
3
T,
Jensen
4
MD ,
Kjeldsen
4
J
1Department
of Hepatology and Gastroenterology, Aarhus University Hospital, Denmark; 2Department of Radiology, Lillebaelt Hospital Vejle, Denmark;
3Department of Internal Medicine, Lillebaelt Hospital Vejle, Denmark; 4Department of Medical Gastroenterology, Odense University Hospital, Denmark.
1. INTRODUCTION
Diffusion-weighted magnetic resonance imaging (dw-MRI) utilizes
differences in the motion of water molecules between tissues for
image formation without administration of contrast materials.
Inflammation in the bowel wall slows water transit resulting in lower
apparent diffusions coefficients (ADC). Previous studies have shown
that dw-MRI combined with conventional MR sequences can be
useful for detection of Crohn’s disease in the terminal ileum and
colon.
The aim of this study was to examine the diagnostic performance of
free-breathing dw-MRI without fasting, bowel preparation or
contrast administration in ileocolonic Crohn’s disease.
Table 1. ADC (x 10-3 mm2/s) in bowel segments with and without active
Crohn’s disease. 95% confidence intervals are displayed in parenthesis. In
the transverse colon, dw-MRI significantly discriminated active from inactive
Crohn’s disease (1.58 x 10− 3 mm2/s vs. 1.18 x 10 − 3 mm2/s, P = 0.01)
2. METHODS
 10 patients with known Crohn’s disease were included in this
prospective and blinded study.
 Ileocolonoscopy with Simple Endoscopic Score for Crohn’s disease
(SES-CD) served as gold standard. Active Crohn’s disease was
defined as a segmental score ≥ 1.
1.00
0.75
0.50
0.25
0.00
 Patients were examined in the prone position before and after
intravenous administration of 20 mg Hyoscin Butylbromide
(Buscopan®, Boehringer Ingelheim, Basel, Switzerland).
Sensitivity
 dw-MRI was performed with a Philips Achieva 1.5T MR system
and body coil (Philips Medical Systems, Eindhoven, The
Netherlands). The MR protocol contained coronal e-thrive and
SShT2 with free-breathing and a factor b fixed at 800 s/mm2.
ROC-analysis for all segments
0.00
0.25
0.50
1-Specif icity
0.75
1.00
dw-MRI
Buscopan:
p ROCwith
area:
0.5644 AUC 0.56
dw-MRI
without Buscopan: AUC 0.64
Ref erence
Figure 2. ROC-analysis revealed an area under the curve (AUC) of 0.56 and
0.64 for dw-MRI with and without Buscopan, respectively (P = 0.3).
3. RESULTS
Demographics
 All patients had active Crohn’s disease.
 Previous ileocecal resection in 3 patients.
 Medical treatment in 7 patients (glucocorticoid 4, glucocoticoid +
azathioprine 3).
Gold standard assessment
 46 bowel segments were assessed with ileocolonoscopy and dwMRI.
 22 (48%) segments were inflamed according to the gold standard.
 Median SES-CD segmental score 4 (range 2-8).
Figure 3. Upper image: dw-MRI showing an increased signal intensity of the
ascending colon on b-800 image. Lower image: Measurement of the
corresponding ADC mapping resulted in an ADC of 0.645 x 10-3 mm2/s
4. CONCLUSIONS
Inactive CD
Active CD
Figure 1. Without Buscopan, there was a trend towards lower ADC in
segments with Crohn’s disease compared to segments without inflammation
(1.43 x 10 − 3 mm2/s vs. 1.48 x 10 − 3 mm2/s, P = 0.08). However, this
difference was not observed with Buscopan (P = 0.49)
The ability of dw-MRI to discriminate Crohn’s disease from
normal bowel segments is inadequate. Large variations of ADC
in normal and diseased bowel segments emphasize the
importance of optimal anatomical distinction for obtaining
precise measurements.
5. REFERENCES
1. Hordonneau C, Buisson A, Scanzi J et al. Am J Gastroenterol 2014;109:89-98.
2. Oussalah A, Laurent V, Brout O et al. Gut 2010;59:1056-1065.