الفهرس 
Introduction and aim of the work
Normal Anatomy Of The Upper Urinary TractOnly 14 pages are availabe for public view
 |  | from | 137 |  |  |
| | | from | 137 | | |
Abstract
Urothelial cancers of the renal pelvis and collecting system constitute approximately 10 % of all renal tumors: 90% are transitional cell carcinoma (TCC), 9% are squamous cell carcinoma, and 1% is mucinous adenocarcinoma. (1)
Patients usually present with gross or microscopic hematuria, dull flank pain, or acute renal colic due to obstruction. Synchronous bladder cancer occurs in 2%–4% of patients with upper tract tumors, this is the reason for a full urothelial screening. (2)
Post contrast MDCT has shown increased sensitivity and specificity for detection of urothelial tumor and is superior to single detector CT in evaluation of the collecting system and ureters. (5)
The term CTU is often used in clinical practice for a multitude of multi-slice CT techniques for evaluation of the urinary tract. The examination involves the use of multi-slice CT with thin-slice imaging, I.V. administration of a contrast medium, and imaging the excretory phase. (52)
Magnetic resonance urography (MRU) is the only other alternative study, which can image all the anatomic components of the urinary tract in a single test. MRU has advantages over multi-slice CT including the ability to image the pelvicaliceal systems without I.V. iodinated contrast agents using heavily T2 weighted ultra-fast sequences. The clinical usefulness of these sequences has been showing helping detect upper urinary tract abnormalities. Another advantage of MRU is that the significant radiation dose associated with the other modalities is avoided. However, contrast is usually required to evaluate the renal parenchyma especially for renal masses. (6)
In conclusion, MDCT urography offers superior detection of urothelial tumor, and parenchymal tumor over EU and US and allows accurate staging of detected lesions at the same examination. MR imaging, including the newer techniques of MR angiography and MR urography, offer comparable evaluation in patients who cannot tolerate iodinated contrast material and in whom multiplanar, vascular, and collecting system imaging is required. Recognition by the radiologist of the variety of appearances of upper tract TCC with all imaging modalities is necessary to detect and stage tumors accurately. In addition, atypical appearances, particularly in advanced tumors, should be recognized .(1)