Biomaterial Database

Duplex Doppler US of the kidney: differentiation of obstructive from nonobstructive dilatation. 1989

J F Platt, and J M Rubin, and J H Ellis, and M A DiPietro

Department of Radiology, University of Michigan Medical Center, Ann Arbor 48109.

Distinction of the obstructed from the nonobstructed dilated renal collecting system is a difficult problem often requiring interventional procedures and pressure measurements. The authors prospectively performed duplex Doppler ultrasound (US) evaluations in 21 kidneys (obstructed, n = 14; nonobstructed, n = 7) immediately before percutaneous nephrostomy. In addition, ten of the obstructed kidneys were evaluated with follow-up Doppler US after percutaneous nephrostomy. Renal obstruction caused a change in the Doppler waveform detected by means of the resistive index (RI). Thirteen of the 14 obstructed kidneys had a RI value greater than .70, while none of the nonobstructed kidneys had a RI value exceeding .70. Relief of the obstruction resulted in a reduced RI; in nine of ten kidneys, the RI was less than or equal to .70 (similar to that of the nonobstructed kidneys). When a dilated collecting system is being imaged, additional evaluation with duplex Doppler US may help distinguish obstructed from nonobstructed dilatation, which may be of particular benefit in patients with conditions that usually predispose them to collecting system dilatation.

UI	MeSH Term	Description	Entries
D007684	Kidney Tubules	Long convoluted tubules in the nephrons. They collect filtrate from blood passing through the KIDNEY GLOMERULUS and process this filtrate into URINE. Each renal tubule consists of a BOWMAN CAPSULE; PROXIMAL KIDNEY TUBULE; LOOP OF HENLE; DISTAL KIDNEY TUBULE; and KIDNEY COLLECTING DUCT leading to the central cavity of the kidney (KIDNEY PELVIS) that connects to the URETER.	Kidney Tubule,Tubule, Kidney,Tubules, Kidney
D007685	Kidney Tubules, Collecting	Straight tubes commencing in the radiate part of the kidney cortex where they receive the curved ends of the distal convoluted tubules. In the medulla the collecting tubules of each pyramid converge to join a central tube (duct of Bellini) which opens on the summit of the papilla.	Kidney Collecting Ducts,Kidney Collecting Duct,Collecting Duct, Kidney,Collecting Ducts, Kidney
D008297	Male		Males
D009403	Nephrostomy, Percutaneous	The insertion of a catheter through the skin and body wall into the kidney pelvis, mainly to provide urine drainage where the ureter is not functional. It is used also to remove or dissolve renal calculi and to diagnose ureteral obstruction.	Percutaneous Nephrostomy,Nephrostomies, Percutaneous,Percutaneous Nephrostomies
D011446	Prospective Studies	Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.	Prospective Study,Studies, Prospective,Study, Prospective
D003937	Diagnosis, Differential	Determination of which one of two or more diseases or conditions a patient is suffering from by systematically comparing and contrasting results of diagnostic measures.	Diagnoses, Differential,Differential Diagnoses,Differential Diagnosis
D004108	Dilatation, Pathologic	The condition of an anatomical structure's being dilated beyond normal dimensions.	Ectasia,Dilatation, Pathological,Dilatations, Pathologic,Dilatations, Pathological,Pathologic Dilatation,Pathologic Dilatations,Pathological Dilatation,Pathological Dilatations
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006869	Hydronephrosis	Abnormal enlargement or swelling of a KIDNEY due to dilation of the KIDNEY CALICES and the KIDNEY PELVIS. It is often associated with obstruction of the URETER or chronic kidney diseases that prevents normal drainage of urine into the URINARY BLADDER.	Hydronephroses