Purpose
Diffusion-weighted imaging (DWI) plays an invaluable role in diagnosing Crohn's disease as it has shown a potential to replace contrast medium administration and provides a quantitative index - apparent diffusion coefficient ADC, to characterise the inflammation [1]. There is a number of DWI techniques that differ in fat suppression type applied. In our institution, SPIR- and STIR- based DWI weighted sequences are used. STIR-based DWI sequence, or DWIBS (Diffusion-Weighted Imaging with Background Body Signal Suppresion), has several advantages over conventional SPIR-based DWI sequence as it...
Methods and materials
Patient population
5 adults (23-57 y.o.) and 12 children (11-17 y.o.) with active Crohn’s disease in the terminal ileal loop were involved in this prospective cross-sectional study. The inclusion criteria were: proven non-stricturizing terminal ileitis with MRI signs of active inflammation: 1) bowel thickness > 3 mm, 2) presence of mural oedema [4], 3) restricted diffusion in both conventional DWI and DWIBS tracking images of b=800 s/mm2, along with low SI in ADC map, 4) early mucosal hyperenhancement in the Gd-enhanced T1 post-contrast series [5]....
Results
In both adult and pediatric patients, there was a weak and statistically unreliable correlation between ADC-DWIBS and ADC-DWI (r=0.274, p=0.13 in adults and r=0.215, p=0.15 in children).
The correlation between DWI-ADC and MaRIA index was moderate negative and statistically reliable in both adults in children (r=-0.5, p
Conclusion
ADC of DWIBS is less suitable for quantitative assessment of inflammatory activity comparing to DWI-ADC in both adults and children. This probably could be related to the non-selectivity of STIR fat suppression, apart from the fat, possibly influencing the ADC by suppression of signal from other substances of short T1 time [7]: 1) the viscous pus contained in crypt abscesses in the bowel wall of Crohn's disease, and 2) due to the partial volume effect, by contamination of the bowel wall signal with a signal...
Personal information and conflict of interest
Ilze Apine, MD
Department of Diagnostic Radiology
Vienibas gatve 45
Riga LV-1004
Phone: +37129461616
Fax: +371270972
e-mail:
[email protected]
All of the authors have nothing to disclose.
References
1.Park S.H. DWI at MR enterography for evaluating bowel inflammation in Crohn disease AJR 2016; 207:40–48
2. Takahara, T.; Imai, Y.; Yamashita, T.; Yasuda, S.; Nasu, S.; Van Cauteren, M. Diffusion weighted whole body imaging with background body signal suppression (DWIBS): Technical improvement using free breathing, STIR and high resolution 3D display. Radiat. Med. 2004, 22, 275–282.
3. Kwee, T.C.; Takahara, T.; Ochiai, R.; Katahira, K.; Van Cauteren, M.; Imai, Y.; Nievelstein, R.A.; Luijten, P.R. Whole-body diffusion-weighted magnetic resonance imaging. Eur. J. Radiol. 2009, 70,...