Objective To investigate the application of magnetic resonance imaging (MRI) in preoperative assessment of rectal cancer. Methods Combined with the literatures, the MRI features and measurements of rectal tumor staging, extramural vascular invasion, circumferential margin involvement, and the distance between distal margin of the tumor from the anorectal ring and the anal margin were described. Results On T2-weighted images (T2WI), T1 staging-tumors were those in which the normal submucosa was replaced by the iso-intensity of tumor tissue without invasion of muscularis propria; T2 staging-tumors were those with extension into the muscularis propria, but not invaded the high-intensity of mesorectal fat; T3 staging-tumors manifested as the rectal tumor penetrated into the muscularis propria and invaded the high-intensity of mesorectal fat; T4 staging-tumors manifested as the tumor invaded adjacent structures or organs. The metastatic lymph nodes were showed with irregular boundaries and mixed signals on T2WI. The tumor signals could be found in the extramural vascular on T1-weighted images (T1WI), accompanied by irregular distortion and expansion of the blood vessels. On T2WI, metastatic lymph nodes, extramural vascular invasion, and the distance between the residual tumor and the low-signal of mesorectal fascia was within 1 mm, indicated the positive circumferential margin. On T2WI, the distal margin of the tumor was located at the junction of hyperintense submucosa and iso-signal of tumor, the tip of the iso-signal puborectal muscle was the apex of the anorectal ring, and the lowest point of the iso-signal external sphincter was the anal margin. Conclusion MRI can provide reliable imaging information for preoperative staging, height measurement, and prognosis of rectal cancer, and it is helpful for early diagnosis and treatment of rectal cancer.
ObjectiveTo investigate long-term efficacy of infliximab (IFX) combined with seton placement in treatment of perianal fistulizing Crohn disease (CD) and to analyze factors affecting its clinical healing and recurrence.MethodsThe patients with perianal fistulizing CD underwent the IFX combined with seton placement therapy from July 2010 to January 2017 were collected from the HIS database of the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine. The healing and recurrence of perianal fistulizing CD were counted and their influencing factors were analyzed.ResultsA total of 103 patients with perianal fistulizing CD were included in the study. After a median follow-up of 36 months, 64 patients (62.1%) had a complete fistula healing, 34 patients (33.0%) relapsed. The cumulative recurrence rates of fistula in the 1, 3, and 5 years was 21.8%, 32.6%, and 37.4%, respectively. The multivariate analysis showed that the Montreal classification B1 ［HR=3.987, 95% CI (1.640, 9.694), P=0.023］ and without abscess ［HR=2.724, 95% CI (1.101, 6.740), P=0.030］ were positively associated with the long-term healing of fistula, and the IFX maintenance treatment >3 times ［HR=5.497, 95% CI (1.197, 25.251), P=0.028］ was a risk factor for the recurrence of the fistula.ConclusionsLong-term healing rate of fistula by IFX combined with seton placement therapy is higher. Montreal classification B1, without abscess, and IFX maintenance treatment less than 3 times are expected to have a better long-term efficacy.