AMSER Kidney Definitions

Kristen Duncan MS4

CT Pre-Clinical vs Clinical Definition
Appropriateness Criteria
IF CT Pre- Contrast aka Non- Contrast PC The initial phase of a CT Urogram, used to evaluate the urinary tract. The pre-contrast, or non-contrast, phase is useful for identifying stones, as well as determining the Hounsfield units of a homogenous renal mass or masses containing macroscopic fat.
IF CT Cortical Phase PC The corticomedullary phase occurs during the arterial phase of a CT with contrast, about 20 seconds after the injection of contrast, resulting in the enhancement of the renal cortex without the medulla.
IF CT Corticomedullary Phase PC The corticomedullary phase of a CT Urogram usually occurs between 40-60 seconds after injection of contrast, resulting in the enhancement of the renal cortex with minimal enhancement of the renal medulla. Best for delineating subcategories of renal cell carcinomas.
IF CT Nephrogram Phase PC A phase of renal CT that usually occurs 100 sec after injection of contrast resulting in optimal enhancement of the renal parenchyma, including the renal medulla, and demonstrates enhancing components of masses.
IF CT Excretory Phase PC A phase of renal CT that usually occurs 5-10 minutes after injection of contrast, resulting in enhancement of calyces, renal pelvis, and ureters. Useful for identifying filling defects of the upper urinary tract.
Ultrasound
IF US Color Doppler PC Utilized to evaluate blood flow to the kidneys, color doppler ultrasound uses color to depict velocity and direction of blood flow. Flow that travels away from the transducer is typically depicted in blue, and flow that is traveling toward the transducer is typically depicted in red. Lighter shades of each color are used to differentiate higher velocities. A third color, usually green or yellow, is often used to denote areas of high flow turbulence.
IF US Pulsed Doppler PC Pulsed wave doppler technology is based on the principle that moving objects change the characteristics of sound waves. It sends short, brief pulses of sound to accurately measure the velocity of blood flow in real time in a user-defined location. It is used to measure renal artery resistive index and pulsatility index.
Findings
IF Finding Abscess Q C Characterized by the presence of a localized collection of pus within the kidney tissue. May be caused by infection or inflammation. Diagnosis is based on clinical symptoms including fever, leukocytosis, and flank pain, as well as imaging with CT or renal US. Treatment usually involves IV antibiotics or IR drainage, depending on the size and severity of the abscess.
IF Finding Calcification Nephrolithiasis Q PC Nephrolithiasis (aka renal calculi) is a stone located in the kidney, caused by dehydration, infection, metabolic abnormalities or urinary tract abnormalities, commonly affecting adults 30-60 years of age, though infants and children can also be affected. Resulting in stone formation within the kidney, which may be complicated by infection or obstruction of urine outflow and resulting pain. Nephrolithiasis can be asymptomatic or patients may present with renal colic, hematuria, stranguria, or pyelonephritis. Diagnosis is made by urinalysis and culture, as well as CT renal stone protocol. Treatment may range from watchful waiting to medication expulsion therapy, to surgery, depending on various patient and stone-specific factors.
IF Finding Calcification Ureterolithiasis Q PC Ureterolithiasis (aka ureteral calculi aka ureteral stones) are characterized by the presence of stones in the ureter, which may be complicated by infection or obstruction of urine outflow and resulting pain. Diagnosis is made by urinalysis and culture, as well as CT renal stone protocol. Treatment may range from watchful waiting to medication expulsion therapy, to surgery, depending on various patient and stone-specific factors.
IF Finding Cyst Complex MRI C Complex renal cysts are cystic masses of the kidney that do not meet the criteria of a simple renal cyst. Characteristics such as a thickened wall, solid components, or enhancement with IV contrast differentiate complex cysts. They are usually asymptomatic. Diagnosis of a complex renal cyst is usually made incidentally, on imaging with renal US or CT. Renal cysts are usually evaluated by complexity on the Bosniak scale to determine likelihood of malignancy and whether intervention such as ablation, partial or total nephrectomy is indicated.
IF Finding Cyst Septated CT C Septated cysts, aka multiloculated cysts, are renal cysts divided into compartments by septa. Diagnosis is usually incidentally made, primarily through renal CT or US imaging. For cysts with few hairline septa and no other complex features, intervention is usually not indicated.
IF Finding Cyst Septated US C
IF Finding Cyst Simple PC Simple renal cysts are benign lesions of the kidney that increase in prevalence with age. They are usually asymptomatic though may result in pain if rupture occurs. Renal cysts are usually evaluated by complexity on the Bosniak scale. Diagnosis of a simple renal cyst is usually made incidentally, with the presence of a homogeneous, thin-walled, non-enhancing fluid-attenuation lesion on a contrast-enhanced CT, or a well-marginated anechoic lesion with thin walls on renal ultrasound. For incidentally noted, simple renal cysts, intervention is not usually required.
IF Finding Cyst Simple CT Q PC
IF Finding Cyst Simple MRI Q PC
IF Finding Cyst Simple US Q PC
IF Finding Filling Defect Calyx Q C Characterized by a space-occupying lesion or abnormality within a calyx of the kidney leading to that area not filling with contrast during imaging. Causes: Can result from various factors, including stones or tumors. Diagnosis: Imaging (CT or intravenous urography). Treatment: Address the underlying cause, which may involve stone removal or tumor management.
IF Finding Filling Defect in the Renal Pelvis Q C Characterized by an abnormality or space-occupying lesion within the renal pelvis leading to that area not filling with contrast during imaging. Causes: Can result from various factors, including stones or tumors. Diagnosis: Imaging (CT or intravenous urography). Treatment: Address the underlying cause, which may involve stone removal or tumor management.
IF Finding Filling Defect Papilla Q C Characterized by an abnormality or space-occupying lesion within the papilla (renal tip) of the kidney leading to that area not filling with contrast during imaging. Can result from various factors, including tumors. Diagnosis is usually made via imaging with CT urogram. Treatment: Address the underlying cause, which may involve tumor management.
IF Finding Filling Defect Ureter Q C Characterized by an abnormality or space-occupying lesion within the ureter, typically seen on imaging. Can result from various factors, including stones or tumors. Diagnosis is usually made via imaging with CT urogram. Treatment: Address the underlying cause, which may involve stone removal or tumor management.
IF Finding Hydronephrosis PC Characterized by the dilation of the renal pelvis and calyces due to an obstruction in the urinary tract, causing urine backup. Causes: Obstruction, stones, tumors, or congenital issues. Diagnosis is made via imaging with ultrasound or CT. Treatment: Address the underlying cause, which may involve foley catheter, stent placement or surgery.
IF Finding Hydroureter Q PC Characterized by the dilation of the ureter due to an obstruction or other urinary tract issue. Causes: Obstruction, stones, tumors, or congenital issues. Diagnosis is usually made via imaging with ultrasound or CT. Treatment: Address the underlying cause, which may involve stent placement or surgery.
IF Finding Laceration Q C Characterized by a tear or injury to kidney tissue, often due to trauma. Presence of flank pain, ecchymosis, and hematuria after a trauma raise suspicion for a renal laceration. Diagnosis is made via imaging (usually CT). Treatment: Supportive care and, in severe cases, surgery.
IF Finding Mass Solid Unilateral Q C Characterized by a solid mass in one kidney. Causes include cancers such as renal cell carcinoma, transitional cell carcinoma, or other rare malignancies vs benign tumors like oncocytomas or angiomyolipomas, hematoma or infection. Diagnosis is made via imaging with CT or MRI. Treatment: Depends on the nature of the mass, which may require surgery or other interventions.
IF Finding Pelvic Kidney Q C Characterized by the location of the kidney in the pelvic area rather than the normal renal fossa. This is a congenital anomaly. Diagnosis usually incidentally made via imaging with CT. Usually no intervention is required if asymptomatic.
IF Finding Perinephric Hematoma Q C Characterized by a collection of blood in the perinephric space surrounding the kidney, often due to trauma or injury. May cause symptoms including flank pain, a palpable mass and hypovolemic shock if severe. Diagnosis made via imaging with CT or US. Treatment: May involve observation, blood transfusion, or IR or surgical intervention.
IF Finding Staghorn Calculus Q PC Characterized by large kidney stones that fill the renal pelvis and calyces, often causing obstruction. May involve an infectious component, often associated with urease-splitting bacteria. Diagnosis suspected with microhematuria or repeat pyelonephritis and confirmed on imaging with CT. Treatment may involve surgical removal or lithotripsy.
IF Finding Subcapsular Hematoma Q C Characterized by a collection of blood between the kidney and its outer covering. Causes may include trauma or other factors. Diagnosis made via clinical history, presence of hematuria and flank pain, and CT or US imaging. Treatment may include observation, blood transfusion, or surgical intervention, depending on the severity.
IF Finding Urinoma Urine Leak Q C Characterized by the leakage of urine into the surrounding tissues, often due to obstruction of urine flow or injury to the urinary tract. Diagnosis is made via clinical history and the presence of contrast extravasation on IV pyelogram or the excretory phase of a CT urogram; a thin-walled, anechoic collection surrounding a part of the urinary tract on ultrasound; or water attenuation of a fluid collection on MRI. Treatment ranges from conservative management to drainage, depending on the size and severity of the urine leak, and addressing the underlying cause.
IF Finding Vesico-Ureteral Reflux Q PC Vesico-ureteral reflux is characterized by the backflow of urine from the bladder into the ureters and kidneys. It is usually a result of a maturation abnormality of the vesicoureteral junction and is typically diagnosed in young children. It may present as an isolated abnormality or associated with other congenital abnormalities. Diagnosis is usually suspected after an incidence of urinary tract infection in a young child and confirmed through imaging with VCUG or cystoscopy. Treatment varies based on the severity of reflux, ranging from prophylactic antibiotics for UTI prevention to surgical reimplantation of the ureters.
Diseases
IF Disease Agenesis PC A congenital condition characterized by the absence of one or both kidneys. If bilateral, the condition is fatal, whereas if unilateral patients typically have a normal life expectancy. Renal agenesis may occur as a solitary abnormality, or may be associated with chromosomal abnormalities or other abnormalities of the urinary tract. Unilateral renal agenesis is asymptomatic and as a result diagnosis is usually made incidentally on imaging for other reasons, if not identified on antenatal screening. Treatment is usually not indicated for unilateral renal agenesis, though these patients may be at increased risk of pyelonephritis, nephrolithiasis, and/or renal failure.
IF Disease Congenital Partial Duplication PC A partially duplex collecting system, or partial duplicated collecting system, is one of the most common congenital renal tract abnormalities. It is characterized by an incomplete fusion of upper and lower pole moieties resulting in a variety of incomplete duplications of the collecting system. While considered an anatomical variant, duplex collecting systems may be complicated by vesicoureteric reflux, obstruction or ureterocele. Most duplicated systems are asymptomatic and diagnosed incidentally on CT imaging. Treatment is usually not indicated for duplication; however, complications such as reflux or hydronephrosis may necessitate intervention.
IF Disease Congenital Total Duplication PC A partially duplex collecting system, or partial duplicated collecting system, is one of the most common congenital renal tract abnormalities. It is characterized by an incomplete fusion of upper and lower pole moieties resulting in a complete duplication of the collecting system. While considered an anatomical variant, duplex collecting systems may be complicated by vesicoureteric reflux, obstruction or ureterocele. Most duplicated systems are asymptomatic and diagnosed incidentally on CT imaging. Treatment is usually not indicated for duplication; however, complications such as reflux or hydronephrosis may necessitate intervention.
IF Disease Congenital Total Duplication of the Collecting System PC
IF Disease Horseshoe Kidney PC A horseshoe kidney a congenital condition where both kidneys are fused at the lower end, forming a horseshoe shape. It is the most common type of renal fusion anomoly. It is most commonly a solitary abnormality, however are occasionally associated with other genetic syndromes. Horseshoe kidney is asymptomatic and usually diagnosed incidentally on imaging; however, it renders the kidneys susceptible to trauma and may result in complications as a result of poor drainage, including stone formation, infection, risk of malignancy and renovascular hypertension. Treatment is not indicated; however, complications may necessitate intervention.