الفهرس 
Ureteral AnatomyOnly 14 pages are availabe for public view
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Abstract
Urinary stones are among the oldest pathological conditions in the history of mankind that was described even before defining the urinary tract itself. They represent a major health and economic burden worldwide. The prevalence of stone disease showed an increasing trend over the past few decades, especially among young adults and females. The incidence of stone disease is affected by different variables including age, race, gender, dietary habits, fluid intake, body habitus, and geographical distribution. The process of urinary stone formation is complex and multifactorial. It starts with urinary supersaturation with any solute, followed by the formation of solid nucleus. Subsequently, new crystals are added to the components of the nucleus in a process known as crystal growth. Finally, the formed crystals in a solution bind together in a process known as crystal aggregation forming larger particles. Urolithiasis is affected by a number of promoters (uric acid and acidic urine) and inhibitors (alkaline urine, pyrophosphate, and Tam-Horsfall protein) of crystallization. Urinary stones may be asymptomatic (usually discovered during routine radiological examination) or it may be associated with renal colic and/or hematuria. Rarely, patients may present with urinary retention (especially in bladder stones) or pyelonephritis. Complications may occur if the patient neglect the stone including urinary tract obstruction, acute and chronic renal failure, and pyelonephritis. The gold standard radiological modality for diagnosis of renal stone is helical non-contrast computed tomography; however, other imaging modalities may play a role in its diagnosis including; KUB, ultrasonography,