tailieunhanh - Essential Urology - part 4

Urography liên quan đến việc tiêm hoặc nhỏ thuốc vật liệu tương phản để hình dung rõ hơn các cấu trúc thu thập hay lumenal thận, niệu quản, bàng quang và niệu đạo. Điều này có thể được thực hiện sau khi tiêm tĩnh mạch hoặc nhỏ thuốc trực tiếp vào đường tiết niệu. | Chapter 5 Basic Imaging in Urology 63 Fig. 1. Normal plain-film KUB showing the renal shadows white arrows caused by perinephric fatty tissue and psoas shadows open arrows . From ref. 3. Fig. 2. Plain-film KUB showing a round density arrow overlying the left renal shadow indicative of a left renal calculus. From ref. 3. 64 Richman and Resnick Fig. 3. Plain-film KUB showing calcific densities overlying bilateral pelvicalyceal systems indicative of staghorn calculi. Bilateral percutaneous nephrostomy tubes white arrows are seen. From ref. 3. UROGRAPHY Urography involves injection or instillation of contrast material to better visualize the collecting or lumenal structures of the kidneys ureters bladder and urethra. This can be done after intravenous injection or direct instillation into the urinary tract. Intravenous Urography The intravenous urogram IVU also called the intravenous pyelogram is the classical modality for imaging the entire urothelial tract from the pyelocalyceal system through the ureters to the bladder. Although newer imaging modalities are frequently used in place of the IVU the IVU is an excellent study for identifying small urothelial lesions as well as the severity of obstruction from calculi. This study provides anatomical and qualitative functional information about the kidneys Figs. 4 and 5 . The IVU is performed after a gentle bowel catharsis to reduce interference from air or stool in the intestines. A preliminary KUB is taken. This film is used to demonstrate calculi or other abnormal calcifications that may be obscured by the contrast. Radiographic contrast is then injected usually as a bolus and a second image is obtained. This first contrast image is the nephrogram phase and shows enhancement of the renal shadows as the kidneys are perfused with contrast. Additional images are taken at timed intervals to display excretion into the collecting system and drainage through the ureters. Filling of the bladder with contrast can demonstrate .