Background: rectal cancer constitutes about one third of all gastrointestinal tumor. High resolution MRI plays a pivotal role in the post-operative follow up and also plays an important role in detection of recurrence. It is the best modality to assess the relations of the rectal tumor and the potential circumferential resection margin (CRM). Therefore it is currently considered the method of choice for local staging of rectal cancer and follows up after total mesorectal excision (TME) and detection of residual or recurrent cancer. Objective: the purpose of this study was to assess the accuracy of MRI in the postoperative assessment rectal carcinoma and detection of recurrence. Subjects and methods: twenty patients with pathologically proven rectal carcinoma underwent pelvic MRI examination. Results: this study was conducted on twenty patients (13 male and 7 female) who underwent surgical excision of pathologically proven cancer rectum. Patients were selected from outpatient's clinic and Department of Surgery at the El-Demerdash Hospital. The patient's age ranges from 32 to 75 years old. Conclusion: MRI of rectal cancer was accurate for post-operative assessment and had high sensitivity with specificity in the detection of recurrence.

Purpose: to assess the effectiveness of diffusion & Dynamic contrast enhanced MRI in imaging of hepatocellular carcinoma after chemoembolization. Patients and Methods: between November 2011 & September 2013, 30 patients were treated with chemoembolization in our interventional radiology unit. All patients underwent pretreatment MRI within 10 days before chemoembolization & post-treatment MRI after one month from treatment. The arterial enhancement as well as the mean Apparent Diffusion Coefficient (ADC) of the focal lesion was prospectively assessed & the percent change in both was assessed. The significance of differences between ADC values of complete & partially responding lesions was calculated. Results: Thirty male patients, ranging in age between 51 & 73 years who met the inclusion criteria were prospectively studied. According to the results of this study, there was a statistically significant difference between patients with partial response & those with complete response as regard the percent change in the mean ADC value of the focal lesion after treatment with P-value less than 0.001. There was significant positive correlation between the percent change in the mean ADC value & the percent change in the diameter of the enhancing tumor tissue after treatment. The percent change in the mean ADC value among patients with complete response was higher than that among patients with partial response with P-value less than 0.001. The best predictive cut off value for differentiation between complete & partial response was 24 % increase in the mean ADC value, with 99 % sensitivity, 84 % specificity, 90 % positive predictive value, 99 % negative predictive value & 86 % accuracy. The % change of the mean ADC value is considered better positive than negative predictor for response to treatment. On the otherhand, there was no statistically significant difference between patients with complete & partial response as regard the mean ADC of the focal lesion before chemoembolization. Conclusion: After chemoembolization, completely responding HCC lesions exhibited more increases in the mean ADC than partially responding lesions. Pretreatment mean ADC values were not predictive of response to chemoembolization