الفهرس 
Acknowledgement
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Abstract
While standard MR modalities show some advantages over CT in assessing the primary bladder tumor, functional MR imaging protocols causing an excellent improvement of overall staging accuracy DWI-MRI is used for assessing local tumor spread ,predicting histological grade and aggressiveness. In addition to guide neo- adjuvant therapy, to refine surgical approaches, to monitor response and relapse after various therapeutic regimes and to assist in predicting and planning for the complications of advancing disease. The regional lymph node metastasis -is also an essential determinant of survival for patients, and this is despite effective local and systematic therapy so detection of metastatic lymph nodes is essential .
In the current work 102 patients with suspicious bladder lesions were referred to Radio-diagnosis department from urology and nephrology hospital, Assiut University ; they underwent MRI study with 1.5T by doing conventional MRI and functional MRI in term of DWI with b-value of 0,150,500,1000.
The aim of this study was to prospectively evaluate the utility of DWI-MRI in diagnosis of bladder wall pathologies, staging of the bladder carcinoma and predict the aggressiveness ,histological cell types and histopathological grades of the tumor and to evaluate the DWI-MRI performance in detection and diagnosis of metastatic lymph nodes .
In this study eight patients had benign lesions with mean ADC of 1.2 x10-3mm2/s and the remaining had malignant lesions with mean ADC of 0.78x10-3mm2/s .Regarding the detection or feasibility of the tumor by DWI we found an excellent performance ,almost all the bladder wall pathologies was clearly seen in 1000 b value as bright signal intensity with sensitivity of 98% and PPV of 96.4%
The specificity and accuracy of the MRI was improved by adding the DWI in the protocol by 75% specificity and 95.2% accuracy.
The current study showed statistically significant difference between benign and malignant bladder wall pathologies regarding ADC value with ≤1x10-3/mm2 ADC cut off for diagnosis of malignant lesions
The pT2 stage was the most common stage in this work, with overall staging accuracy for DWI alone or with T2WI about 68.5%.
Depth of the tumor invasion can determined the treatment of choice, regarding that we found the DWI plus MRI had higher accuracy of 96.7% in differentiation superficial from invasive tumors with cut off ≤0.8 x10-3mm2/s ADC value for diagnosis of invasive tumor and accuracy of MRI plus DWI for differentiation organ confined tumor from organ non confined tumor was 83%which was superior than MRI alone .
The tumor aggressiveness can be predicted by using ADC value as predictor factor, there was an inverse relation- ship of the histopathological grades with ADC, cut off value for predict low grade from high grade tumors was <0.9 x10-3mm2.
In current study TCC was the most histological subtype followed by SCC however there was statistically insignificant difference between the different cell types using ADC value.
Although there was a noticeable ADC overlap between metastatic and non metastatic lymph nodes as the reactive hyperplasia within lymph nodes caused false positive condition. DWI can predicate the presence of lymph nodes metastasis which gives the surgeon a chance to remove all suspicious lymph nodes which isn’t in routine dissection template.