Kidney Flashcards
In what region are the kidneys located?
Retroperitoneal
Gerota’s Fascia
Fibrous sheath surrounding kidneys, perinephric fat, & adrenals
Renal hilum
“Door of the kidney;” where renal artery, vein, lymphatic vessels, & ureter enter the kidney
Normal size of renal cortex
> 1.5 cm
Cortex
Darker area of kidney
Medulla
Contains the renal pyramids
Columns of Bertin
Area of cortex between renal pyramids
Avg. size of kidney
10-12 cm
Which renal vein is longer?
Left renal vein is longer since IVC is on the right side of body
Which renal artery is longer? Why?
Right renal artery is longer since aorta is on the left side of body
Flow towards kidney
Aorta → Renal artery → Interlobular Arteries → Arcuate Arteries → Interlobular Arteries → Glomerulus
Flow from Kidney
Efferent Arterioles → Peritubular Capillaries → Interlobar Veins → Arcuate Veins → Interlobar Veins → Renal Vein → IVC
Functions of the Kidney
- Dispose of waste through urine
- Main blood pressure through fluid regulation
- Regulate acid/base/electrolytes
2 Hormones of renal function
Aldosterone & ADH
Hypertrophied Column of Bertin
Variant, larger than normal cortical tissue
Dromedary Hump
Variant, bulge in capsule of left kidney due to compression by spleen
Bilateral Renal Agenesis
Absence of both kidneys, fatal
Unilateral Renal Agenesis
Absence of one kidney
Supernumery Kidney
Variant, duplicated kidney
Pelvic Kidney
Variant due to failure of kidney to ascend
What is the most common ectopic kidney?
Pelvic Kidney
Crossed Fused Renal Ectopia
Both kidneys on the same side & fused
Thoracic Kidney
Kidney in thorax due to diaphragmatic hernia in utero
Horseshoe Kidney
Fusion of kidneys at lower poles
What is the most common fusion of kidneys?
Horseshoe kidney
Cake/lump kidney
Fusion of kidney in medial surface
Sigmoid Kidney
Upper pole of one kidney fused to lower pole of other
Unilateral Hypoplasia
aka Compensatory Hyperplasia; one small kidney & a larger kidney to compensate
Persistant Fetal Lobulation
Lobulation in contour after 5 years of age
Double Collecting System
Variant, 2 collecting systems from 1 kidney
Most common anomaly of the urinary tract
Double collecting system
Parapelvic Cyst
Located in the sinus hilum region
Hematoma
Localized blood collection
Abscess
Caused by infection
Ultrasound appearance of Abcess
Poorly defined, thick walls, acoustic shadowing
Pyelonephritis
Inflammation of kidney substance & pelvis; due to bacteria/infection in urinary tract
Acute Lobar Nephronia
Focal bacteria nephritis, affects renal lobes
Ultrasound Appearance of Acute Lobar Nephronia
Decreased echogenicity in single area, wedge shaped, no abscess
Autosomal Dominant Polycystic Disease
Bilateral enlargement of kidney with many cysts, hyperechoic. Cysts may be present in liver, pancreas, and spleen
Autosomal Recessive Polycystic Disease
Infantile; detected in utero w/ oligohydramnios. Associated w/ renal dysfunction & lung hypoplasia
Oligohydramnios
Decreased amount of amniotic fluid during pregnancy due to the baby not urinating
Multicystic Dysplastic Kidney
Unilateral, cysts do not communicate. Caused by unilateral obstruction in early development
Most common cause of abdominal mass in newborn
Multicystic Dysplastic Kidney
Hydronephrosis
Obstruction of urine outflow, causing dilation of the renal pelvis.
Bilateral or unilateral
Non-Obstructive cause of Hydronephrosis
Vesicouretal Reflux
Obstructive Cause of Hydronephrosis
Nephrolithiasis, carcinoma, BPH (enlargement of prostate) pregnancy, congenital, etc
Nephrolithiasis
Formation of kidney stones, can form at any level. Consist of calcium oxalate and/or phosphate
How to differentiate between kidney stones and calcified arteries?
Arteries will not have posterior shadowing
Medullary distinction
Lost in chronic renal failure
Angiomyolipoma
Benign mass composed of blood, muscles, and fat
Where do angiomyolipomas occurs??
Unilaterally, solitary, in females 40-60
Mass associated w Tuberous Sclerosis
Angiomyolipma
Ultrasound Appearance of Angiomyolipoma
Homogenous, well defined, hyperechoic
Renal Adenoma
Benign mass found in renal cortex
Ultrasound Appearance of Renal Adenoma
Hypoechoic/isoechoic, well circumscribed, < 3cm
Oncocytoma
Uncommon benign mass, often found in adult males. Pose a risk for hemorrage and scarring
Renal Cell Carcinoma aka
Hypernephroma, Von Grawitz Tumor, Renal Adenocarcinoma
Most common adult renal malignancy
Renal Cell Carcinoma
Ultrasound appearance of Hypernephroma
Variable, irregula, hypoechoic, calcification
Signs/Symptoms of Renal Adenocarcinoma
Flank pain, weight loss, hematuria, fever
Renal Cell Carcinoma uni/bi
Unilateral
Transitional Cell Carcinoma
Malignancy in the transitional cells of the urinary tract
Occurence of transitional cell carcinoma
Occurs in kidney, pelvis, ureter, bladder & 60+ males
Transitional Cell Carcinoma may result in
Hematuria & hydronephrosis
Ultrasound Appearance of Transitional Cell Carcinoma in bladder
Non-mobile focal masses in bladder lumen
Location of transplanted kidney
In an inverted position & in iliac fossa to connect to iliac artery
Role of Ultrasound in Transplant
Patients who present w azotemia, hydronephrosis, peri-renal fluid collections, vascular complications