OBJECTIVE: The objective of our study was to perform a semiquantitative analysis of dynamic contrast-enhanced MRI for the evaluation of disease activity and therapeutic response in patients with perianal fistulizing Crohn disease. SUBJECTS AND METHODS: Sixteen consecutively registered patients with perianal Crohn disease underwent pelvic MRI. A dynamic contrast-enhanced sequence was performed at 3 T (temporal resolution, 4.2 seconds) during i.v. contrast injection. Maximum enhancement, initial slope of increase, volume transfer constant (K(trans)), and the extravascular space fractional volume (x028B;(e)) were calculated in a region of interest drawn around the fistula. Perianal disease activity index, C-reactive protein concentration, and an MRI-based activity score were calculated as reference standards. Six patients underwent a second MRI examination 6 weeks after starting treatment with anti-tumor necrosis factor α (anti-TNF-α). RESULTS: Perianal disease activity index moderately correlated with maximum enhancement (r = 0.67, p = 0.005), initial slope of increase (r = 0.58, p = 0.018), and volume of enhancing pixels (r = 0.79, p < 0.001) but not with K(trans) or x028B;(e). Volume of enhancing pixels also correlated with C-reactive protein concentration and the MRI-based score (r = 0.52, p = 0.041; r = 0.79, p < 0.001). The K(trans) values had decreased significantly 6 weeks after the start of anti-TNF-α therapy. CONCLUSION: Maximum enhancement and initial slope of increase correlate with disease activity in perianal Crohn disease. K(trans) may be an indicator of the effect of therapy on patients starting anti-TNF-α treatment.
OBJECTIVE: The objective of our study was to perform a semiquantitative analysis of dynamic contrast-enhanced MRI for the evaluation of disease activity and therapeutic response in patients with perianal fistulizing Crohn disease. SUBJECTS AND METHODS: Sixteen consecutively registered patients with perianal Crohn disease underwent pelvic MRI. A dynamic contrast-enhanced sequence was performed at 3 T (temporal resolution, 4.2 seconds) during i.v. contrast injection. Maximum enhancement, initial slope of increase, volume transfer constant (K(trans)), and the extravascular space fractional volume (x028B;(e)) were calculated in a region of interest drawn around the fistula. Perianal disease activity index, C-reactive protein concentration, and an MRI-based activity score were calculated as reference standards. Six patients underwent a second MRI examination 6 weeks after starting treatment with anti-tumor necrosis factor α (anti-TNF-α). RESULTS: Perianal disease activity index moderately correlated with maximum enhancement (r = 0.67, p = 0.005), initial slope of increase (r = 0.58, p = 0.018), and volume of enhancing pixels (r = 0.79, p < 0.001) but not with K(trans) or x028B;(e). Volume of enhancing pixels also correlated with C-reactive protein concentration and the MRI-based score (r = 0.52, p = 0.041; r = 0.79, p < 0.001). The K(trans) values had decreased significantly 6 weeks after the start of anti-TNF-α therapy. CONCLUSION: Maximum enhancement and initial slope of increase correlate with disease activity in perianal Crohn disease. K(trans) may be an indicator of the effect of therapy on patients starting anti-TNF-α treatment.
Authors: S Halligan; D Tolan; M M Amitai; C Hoeffel; S H Kim; F Maccioni; M M Morrin; K J Mortele; S R Rafaelsen; J Rimola; S Schmidt; J Stoker; J Yang Journal: Eur Radiol Date: 2020-04-19 Impact factor: 5.315