الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
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Abstract
The prostate is an exocrine gland composed of both glandular and non-glandular tissue. It is a cone-shaped organ encircling the neck of bladder and urethra with the apex located immediately above the urogenital diaphragm and the broad base below the bladder (Kim B. & Kim C.K, 2013).
Prostate cancer is one of the most common malignancies in elderly men and it is one of the leading causes of cancer-related mortality (Zidan et al, 2015). Localization of prostate cancer is an important given in the emergence of disease-targeted therapies. Knowledge of the lesion location within the prostate can help to direct maximal therapy to the largest focus of tumor while minimizing damage to the surrounding structures, such as the neurovascular bundles, the rectal wall and the bladder neck (Haider et al , 2007)
By 1990, trans rectal ultrasound (TRUS) has emerged as the best imaging modality of the prostate. Its use led to an improved understanding and demonstration of intra glandular anatomy. For long time, TRUS is used screening, diagnosis and monitoring of benign disease, prostatic cancer and for guiding biopsy from the suspicious lesions (Kammermeir, 1991).
Recently, great interest has been shown in multi-parametric MRI, which combines anatomic T2-weighted (T2W) imaging and T1Wwith MR spectroscopic imaging (MRSI), diffusion-weighted imaging (DWI) and/or dynamic contrast-enhanced MRI (DCE-MRI) (Sciarra et al, 2011). T1W images are not used for diagnostic purposes because
zonal anatomy is difficult to identify and tumors are typically not well seen. However, T1W images are helpful in determining if there is residual hemorrhage due to prior biopsy (Sankineni et al, 2016)
High-resolution axial T2-TSE is the backbone of every MR image of the prostate. T2W imaging allows precise visualization of the zonal anatomy of the prostate. Moreover, nodular, glandular, stromal, and cystic changes in benign prostate hyperplasia (BPH) can be reliably visualized. Prostate carcinomas can be detected in T2w imaging on the basis of their low-signal, classic oval shape as well as their space-occupying nature once they reach a certain size. For T2w imaging without functional sequences, the sensitivity and specificity for prostate cancer are approximately 57 – 83 % and 62 – 82 %. The diagnostic limitations of T2w imaging alone are due to the often similar nature of regularly occurring acute and chronic inflammation of the prostate and hemorrhages, which also cause a hypo intense pattern in T2w imaging. (Durmus et al, 2014).
Aim of our study was to evaluate the diagnostic accuracy of MRI techniques in detection and characterization of different prostatic lesions in comparison with TRUS, and to highlight the value of the advanced MRI techniques in accurate detection, localization and staging of cancer prostate.
In our study, by using conventional MRI almost half of the cases 17 (56.7%) had enlarged transitional zone with abnormal peripheral zone, By MR diffusion there was restriction in 21 (70%) cases, only 7 of them were benign , 2 cases were cystic lesions (prostatic abscess) , 5 cases were (atrophic and granulomatous prostatitis), while 14 cases were malignant and only one case histopathologically proved to be prostate cancer with no restriction.
However, MRI spectroscopy of peripheral zone showed 17 cases were suggesting cancer with percentage of 56.7% (15 case histopathologically proved to be prostatic carcinoma and 2 cases were granulomatous prostatitis) , 3 cases were border line ( histopathologically proved to be benign lesions (atrophic prostatitis) with percentage of 10% and only 10 cases were normal with percentage of 33.33%.
By MRI spectroscopy of transitional zone ,2 cases were showing results suggesting cancer with percentage of 6.7% (proved to be prostatic sarcoma ), 4 cases were borderline with percentage of 13.3% (infarction & granulomatous prostatitis) and 21 cases were normal with percentage of 70%.
By Contrast enhanced MRI, we found that only 11 cases with percentage of 36.6% were valid, as 4 are enhanced with percentage of 13.3 while 7 show no enhancement with percentage of 23.3. We found that with MRI about 18 of cases are diagnosed with prostate cancer with percentage of 60%, 4 case are diagnosed as cystic lesion with percentage of 13.3%, 4 case are diagnosed as BPH with percentage of 13.3% and last 4 are suspicious with 13.3%. 18 of cases are diagnosed as malignant with percentage of 60%, 4 case are diagnosed as suspicious with percentage of 13.3%, 8 case are diagnosed as benign with percentage of 26.6%.
By using TRUS in our study, we found that about 13 cases have enlargement with nodule with percentage of 43.3% )6 case were histopathologically proved as malignant lesions and 7 were benign ), 13 cases have enlargement without nodule with percentage of 43.3% )9 case were histopathologically proved as malignant lesions and 4 were benign ), and 4 cases have cystic lesion with percentage of 13.3% .
Also by TRUS 4 of cases were diagnosed as malignancy (proved histopathologically) with percentage of 13.3% , 4 case were diagnosed as cystic lesion with percentage of 13.3% , 11 case were diagnosed as BPH (also proved histopathologically) with percentage of 36.7% and last 11 were suspicious & for biopsy with percentage of 36.7% ) 4 case were histopathologically proved as malignant lesions and 7 were benign ). This was similar to several previous studies as study from Singapore was performed on 24 men, cancer detection rate of 59.2% (Yuen et al. 2004) and Zangos et al. (2005)
Conclusion
Prostate cancer represents about 13.3 % of cases, as 22.2 % of cases are diagnosed by MRI while TRUS diagnosed 100% of cases with significant difference between the two groups. It shows that cystic lesion represents about 13.3 % of cases, as 100 % of cases are diagnosed by MRI and also TRUS diagnosed 100% of cases with significant difference between the two groups. It also shows that BPH represents about 13.3 % of cases, as 100 % of cases are diagnosed by MRI and while TRUS diagnosed 36.4 % of cases with significant difference between the two groups. We found also that malignancy represents about 13.3 % of cases, as 26.7 % of cases are diagnosed by MRI while TRUS diagnosed 100% of cases with significant difference between the two groups. It shows that benign lesion represents about 26.7% % of cases, as 100 % of cases are diagnosed by MRI and also TRUS diagnosed 53.3% of cases with significant difference between the two groups. It also shows that suspicious represents about 16.7 % of cases, as 71.4 % of cases are diagnosed by MRI and while TRUS diagnosed 45.5 % of cases with significant difference between the two groups. True positive represents about 20 % of cases, as 40 % of cases are diagnosed by MRI while TRUS diagnosed 100% of cases with significant difference between the two groups. It shows that true negative represents about 26.7% % of cases, as 100 % of cases are diagnosed by MRI and also TRUS diagnosed 100% of cases with significant difference between the two groups. It also shows that false positive represents about 23.3 % of cases, as 100 % of cases are diagnosed by MRI and while TRUS diagnosed 77.8 % of cases with significant difference between the two groups.