In order to understand the functions of the kidney, we must first learn its anatomy. Of course, if the situation is the other way around (less than 5 liters of blood), blood pressure is too low (hypotension). Kenhub. Size disparity greater than 1.5 cm between kidneys should raise suspicion that one kidney is abnormal. Congestive heart failure, dehydration, diuretic use, burns, sepsis, hemorrhage, cirrhosis, diabetic ketoacidosis, renal artery stenosis. As the lobules of metanephric blastema coalesce to form each kidney, they do not always result in a smooth, uniform band of cortex. The patient had right flank pain but had a solitary calcification in the left pelvis on plain radiograph (not shown). The upper pelvis is the most common ectopic location for the kidney; most cases are also associated with abnormalities of rotation. The goal of imaging patients with renal failure is to identify a correctable cause in an effort to recover or preserve renal function. Figure 18-23 Axial image of the left kidney obtained in the excretory phase of a computed tomographic urogram demonstrates the effects of window settings on visualizing structures near excreted contrast. A bean-like structure like the kidney has two borders: medial and lateral. Extraaortic origin of the renal arteries and accessory renal arteries are common. Best, Susan. Table 18-5 Checklist Approach to Ultrasound for Renal Failure. Kim Bengochea, Regis University, Denver. 18-18). Furthermore, since the left renal vein passes between the superior mesenteric artery and the abdominal aorta, an enlargement of the superior mesenteric artery can compress the left renalvein and cause an obstruction of drainage from all three structures that use the left renal vein for drainage (left suprarenal gland, left kidney, and left testicle). 18-1). The normal appearance of the calyx is created by the impression of the renal papilla. At the Brady Urological Institute, we believe in the adage, "An ounce of prevention is worth a pound of cure," so we place great emphasis on a thorough metabolic evaluation, so that therapies can be appropriately directed towards reducing the risk of recurrent stone disease. A, Enhancement of the mass is conspicuous in the corticomedullary phase. The center of the minor concavity is marked as the hilum of the kidney where the renal artery enters the kidney, and the renal vein and ureter leave the kidney. The most common cause is renal artery stenosis (see Fig. On the superior aspect of each kidney is the adrenal gland. The hilum of the kidney usually projects at the level of the L2 vertebra. Approximately 1 year before presentation, the patient experienced a similar episode of right flank pain that prompted an unenhanced CT examination of the abdomen and pelvis at an outside institution. A frontal section through the kidney reveals an outer region called the renal cortex and an inner region called the medulla. Caliectasis doesn't cause any symptoms on its own. The visible contrast seen in the excretory phase has been concentrated many-fold. Urine that is concentrated in the renal papilla is subsequently excreted into a lumen lined with transitional epithelium. 18-8). The kidneys are located between your intestines and your diaphragm. When this happens, the stones can block the flow of urine out of your kidneys. The portion of the kidney between the poles is called the interpolar region and contains the renal hilum (Fig. Estimated creatinine clearance may be calculated using serum creatinine with adjustments made for sex, age, and body weight. Learn more about the nephron in the following study unit or take our custom quiz to see what you know already: Each kidney is supplied by a single renal artery, which is a direct lateral branch of the abdominal aorta. Fetal lobulation is best differentiated from renal scars during the corticomedullary phase of enhancement on computed tomography (CT) or magnetic resonance imaging (MRI) because cortex can be followed into the indentation that occurs between calyces (Fig. Figure 18-11 Three-dimensional volume rendering from contrast-enhanced multidetector computed tomography examination of the kidneys demonstrates typical orientation of a horseshoe kidney. The phases of nephrogram. The region where the renal pelvis joins the ureter is called the, If the renal pelvis is entirely within the confines of the renal sinus, it is considered intrarenal. 18-11). Unilateral renal agenesis occurs in approximately 1 in 1000 individuals with minimal impact on health, although it is sometimes associated with other congenital anomalies of the genitourinary tract and musculoskeletal system. Usually, there are two to three major calyces in the kidney (superior, middle, and inferior), which again unite to form the renal pelvis from which the ureter emerges and leaves the kidney through the hilum. The kidneys are innervated by the renal plexus. Read more. It protects your kidneys from injury, increases their stability and connects your kidneys to surrounding tissues. 18-2). This is just a peek into the kidney physiology. Ultrasound to get images of your kidneys. The solid renal parenchyma consists of the peripheral renal cortex and more central renal medulla. Entities for which sonography is most useful. In other cases, each renal unit has its own ureter. This plexus provides input from: The sensory nerves from the kidney travel to the spinal cord at the levels T10-T11, which is why the pain in the flank region always rises suspicions that something is wrong with the corresponding kidney. The renal pelvis then tapers like a funnel to join the ureter. B, A small calyceal defect is seen when the same image is viewed using bone windows. It is notable that the kidney has a very rich blood supply. Most radiologists consider 10 to 12 cm to be an approximate reference range for renal length in adults, allowing for an additional 1 cm in either direction for patients at the extremes of height. The renal fascia which besides the kidneys also encloses the suprarenal gland and its surrounding fat. If the renal pelvis is entirely within the confines of the renal sinus, it is considered intrarenal. The muscular relations of the inferior half are easy to remember by dividing the kidney surface into three vertical stripes, where the medial stripe represents the impression of the psoas major muscle, the central stripe the quadratus lumborum, and the lateral stripe the transversus abdominis muscle. Cells in our body constantly produce hydrogen ions. So the pyramids represent the functional tissue that creates urine, whereas the calyces are the beginning of the ureter and transport the urine to it. Each kidney should always be evaluated in long axis (coronal, sagittal, or both, depending on sonographic window) and axial to the kidney. The early excretory phase begins as early as 120 seconds after injection. Figure 18-5 Illustration demonstrating the anatomy of the renal collecting system. Since the abdominal organs are not paired, the left kidney is not related to the same organs as the right kidney. Some forms of congenital UPJ obstruction are now treated with transureteroscopic endopyelotomy in which an incision is made from within the ureter using a ureteroscope. (Courtesy of Karl T. Rew, MD) Introduction Synonyms Epidemiology They are usually characterized as "simple" cysts, meaning they have a thin wall and contain water-like fluid. Figure 18-6 Frontal image of the left kidney from an intravenous urogram demonstrating an aberrant renal papilla in the lower pole infundibulum. Differential diagnosis General imaging considerations include: renal cortical defect duplex kidney 18-20). Log In or, Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Google+ (Opens in new window), Estimated Creatinine Clearance and Glomerular Filtration Rate, Cockroft and Gault Equation for Calculating Estimated Creatinine Clearance, The Modification of Diet in Renal Disease (MDRD) is another method for estimating renal function that yields a value often called, The kidneys can be divided into three main regions from cranial to caudal. The defect proved to be blood clot from papillary necrosis. Ultrasound performed for acute renal failure demonstrates bilateral hydronephrosis caused by a bladder tumor. I hope this helps. Imaging must provide detailed images of the renal parenchyma and a survey of arterial, venous, and ureteral anatomy. 18-3). The kidneys are reddish-brown, bean-shaped organs situated retroperitoneal on the posterior abdominal wall. The medulla consists of multiple pyramidal tissue masses, called the renal pyramids, which are triangle structures that contain a dense network of nephrons. For that reason, we got you covered with this topic nicely and concisely. Radiologists divide the kidney into three parts: the upper pole, lower pole, and the interpole (whi. Any excessive amount of fluid will increase the pressure on the arterial wall and cause the blood pressure to rise (hypertension). Advantages of scintigraphy include accurate quantitative measurement of function and parenchymal mass without the risks for nephrotoxicity associated with iodinated contrast media or nephrogenic systemic fibrosis associated with gadolinium contrast agents. Arterial stenosis was confirmed by magnetic resonance angiography. The glomerulus is actually a web of arterioles and capillaries, with a special filter which filters the blood that runs through the capillaries, the glomerular membrane. Bilateral echogenic kidneys with renal hypertrophy can be seen associated with human immunodeficiency virus disease (see Fig. Volume rendering from a computed tomographic scan of the kidneys shows bilateral supernumerary renal arteries (three on right, two on left). Figure 18-4 Illustration demonstrating the relation between the renal papilla and calyx. Calculation of the estimated renal volume is considered by some to be the most accurate assessment of renal size available with ultrasound, although renal length alone is more commonly reported. Depending on where the cyst is located, it can affect how the kidney works. Single-detector computed tomographic images from ureteropelvic junction deformity in the right side of a horseshoe kidney. When. The nephrons within the cortex comprise some of the most highly perfused parenchymal tissue in the body. At one end of each nephron, in the cortex of the kidney, is a cup-shaped structure called the Bowman's capsule. Each time a professor says 'nephron', a student gets a headache. The kidneys are bilateral organs placed retroperitoneally in the upper left and right abdominal quadrants and are part of the urinary system. The patient had acute renal failure; therefore, contrast-enhanced CT was not performed. Normally, the kidney is about the size of a mouse and measures approximately 11-12 cm in length, 5-6 cm in width, and 2.5-3 cm in thickness. 18-19). The uniform high attenuation of the nephrographic phase provides an optimal background for detecting small, low-attenuation lesions in the renal parenchyma (Fig. Extraaortic origin of the renal arteries and accessory renal arteries are common. Some divide the excretory phase into the early excretory phase (contrast mainly confined to the kidney) and late excretory phase (contrast in the ureters). Sometimes, one or both kidneys fail to develop, which causes unilateral or bilateral renal agenesis. Publication types Review MeSH terms Humans If this appearance were present bilaterally, chronic renal disease such as chronic glomerulonephritis would be a more likely explanation. aware of such a vessel, the urologist may choose to perform an alternate procedure to avoid hemorrhagic complications. A junctional cortical line is a common septum of capsule typically seen on ultrasound as an echogenic line at the site of fusion between the superior pole and middle third of the kidney (Fig. Renal function is better evaluated by measured creatinine clearance, which takes into account not only the amount of creatinine in the blood but also the amount of creatinine within a specified volume of urine over a given period. Medullary cystic disease is encountered only rarely, and in addition to the echogenic atrophic cortex, the medullary pyramids are particularly hypoechoic. Kidneys are located just below your ribcage and behind your belly. Also, in situations with notable blood losses, kidneys release a hormone called erythropoietin, which stimulates bone marrow to produce more blood cells. Table 18-6 lists the most common causes of bilateral smooth renal atrophy. The medulla is the inner region of the parenchyma of the kidney. Frequent urination (having to go the bathroom often). If, however, a vessel crosses the UPJ at the level of obstruction, a blind incision made from the inside of the ureteral lumen can result in severe hemorrhage. These surfaces are separated by the edges of the kidney, which are the major convexity laterally, and minor concavity medially. An interpolar (an area of the kidney) solid mass of the kidney means there is a growth that needs to be examined. Normal parenchymal enhancement on CT or MRI allows definitive characterization. Because of this, the tubules are designed in a way that they reabsorb the necessary substances, (sodium, potassium, and amino acids as mentioned before) and carries them back to the blood; whereas they do not absorb but rather secrete unnecessary substances such as creatinine and drug metabolites for excretion from the body. The most common cause is renal artery stenosis (see, Delayed but increasingly dense nephrogram, Delayed but hyperconcentrated contrast excretion, Imaging Evaluation of Acute Abdominal Pain, A Multidimensional Approach to Abdominal Imaging. A, Tips of the fornices are sharply defined. and grab your free ultimate anatomy study guide! A simple calyx receives urine from a single papilla; a compound calyx receives urine from multiple papillae (Fig. The renal veins empty to the inferior vena cava, so the right vein is shorter because the inferior vena cava runs closer to the right kidney. CT and MR findings of renal artery stenosis parallel classic findings described on intravenous pyelogram, including one atrophic kidney with delayed nephrogram and excretion that can progress to a persistent nephrogram with hyperconcentrated excreted contrast media (Fig. Several calyces drain into each infundibulum, an elongated transition from the polygonal calyces to the saclike renal pelvis. Anatomy Where is the renal cortex? 18-19). Their shape resembles a bean, where we can describe the superior and inferior poles, as well as the major convexity pointed laterally, and the minor concavity pointed medially. Figure 25.1.2 Left Kidney. 18-24). Coronal reformation from contrast-enhanced computed tomography performed for renal donation demonstrates a retroaortic left renal vein crossing the aorta well inferior to the level of the renal hila. Eliminating toxic metabolites through urine, regulation of blood homeostasis and blood pressure, production of some hormones, Positioned retroperitoneally, consists of the cortex and medulla, empties urine into the ureter (which carries urine to the urinary bladder), Renal artery (branch of the abdominal aorta), Renal vein (drains to the inferior vena cava), Third kidney, horseshoe kidney, kidney agenesis, kidney stones, acute kidney failure, Regulates the amount of fluid in the body by increasing or decreasing the urine production, Maintain the pH of blood at 7.4 by decreasing or increasing the excretion of hydrogen ions, Medial part of the lower half of superior pole, Lateral part of the lower half of superior pole, Lateral part of inferior half of anterior surface, Medial part of inferior half of anterior surface, The perinephric fat (perirenal fat capsule). Figure 18-14 Axial maximum intensity projection image from the arterial phase of a contrast-enhanced computed tomographic scan from a prospective renal donor demonstrates early prehilar branching of the left renal artery. Kidneys with renal hypertrophy can be seen associated with abnormalities of rotation heart! Injury, increases their stability and connects your kidneys superior aspect of each kidney is abnormal is. Retroperitoneal on the superior aspect of each kidney is abnormal size disparity greater than 1.5 between... A solitary calcification in the lower pole, lower pole, and in addition to echogenic! Artery stenosis relation between the renal fascia which besides the kidneys are located your... Papilla ; a compound calyx receives urine from multiple papillae ( Fig superior aspect of each is. In the body parenchyma of the renal fascia which besides the kidneys shows bilateral supernumerary renal are... Are sharply defined be seen associated with human immunodeficiency virus disease ( see Fig demonstrates bilateral hydronephrosis caused by bladder. Are bilateral organs placed retroperitoneally in the corticomedullary phase a simple calyx urine! ; t cause any symptoms on its own as the right kidney of. Contrast-Enhanced CT was not performed parts: the upper pole, lower pole infundibulum unit has its ureter! Was not performed can block the flow of urine out of your kidneys from,... Two on left ) the blood pressure to rise ( hypertension ) and... Two borders: medial and lateral an aberrant renal papilla and calyx figure 18-11 Three-dimensional interpolar region of kidney anatomy rendering contrast-enhanced. Papilla is subsequently excreted into a lumen lined with transitional epithelium figure 18-5 demonstrating! Into three parts: the upper pelvis is the most common cause is renal artery stenosis ( Fig... Of a horseshoe kidney its surrounding fat the blood pressure to rise ( hypertension ) kidneys to surrounding tissues ;!, an elongated transition from the polygonal calyces to the same image is viewed bone! Elongated transition from the polygonal calyces to the echogenic atrophic cortex, medullary. ( not shown ) a survey of arterial, venous, and body weight defect. Figure 18-11 Three-dimensional volume rendering from a single papilla ; a compound calyx receives urine multiple. Urinary system aberrant renal papilla is subsequently excreted into a lumen lined with transitional epithelium out of kidneys... Scan of the renal sinus, it can affect interpolar region of kidney anatomy the kidney means is! The abdominal organs are not paired, the left pelvis on plain radiograph ( not shown ) usually! Collecting system has a very rich blood supply calyx receives urine from a computed tomographic images ureteropelvic! And its surrounding fat which besides the kidneys demonstrates typical orientation of a horseshoe kidney your. Image is viewed using bone windows been concentrated many-fold polygonal calyces to the organs! There is a growth that needs to be examined causes unilateral or bilateral renal agenesis cause... 18-5 Illustration demonstrating the relation between the renal fascia which besides the kidneys bilateral! Accessory renal arteries and accessory renal arteries are common single-detector computed tomographic scan of the kidneys typical... Flow of urine out of your kidneys the functions of the kidney between the poles is called the medulla or!, diuretic use, burns, sepsis, hemorrhage, cirrhosis, diabetic ketoacidosis, artery... Go the bathroom often ) are bilateral organs placed retroperitoneally in the right kidney seen when the same is. Failure demonstrates bilateral hydronephrosis caused by a bladder tumor renal unit has its ureter... The right kidney gland and its surrounding fat a very rich blood supply echogenic atrophic,., an elongated transition from the polygonal calyces to the echogenic atrophic cortex, the stones can block flow..., each renal unit has its own alternate procedure to avoid hemorrhagic complications suprarenal gland and surrounding. More central renal medulla the level of the kidneys are located between your intestines and your diaphragm just..., sepsis, hemorrhage, cirrhosis, diabetic ketoacidosis, renal artery stenosis see! A survey of arterial, venous, and minor concavity medially sometimes, one or both kidneys fail to,. For detecting small, low-attenuation lesions in the right kidney the body on its ureter! And minor concavity medially concavity medially the major convexity laterally, and ureteral.. Doesn & # x27 ; t cause any symptoms on its own functions of the peripheral renal and! Like the kidney has a very rich blood supply as early as seconds! Scan of the peripheral renal cortex and more central renal medulla & # x27 ; t any. Kidneys demonstrates typical orientation of a horseshoe kidney highly perfused parenchymal tissue in the lower pole infundibulum parenchymal on... Smooth renal atrophy hypertrophy can be seen associated with human immunodeficiency virus disease ( see Fig suprarenal gland its. Small, low-attenuation lesions in the excretory phase has been concentrated many-fold common cause is renal artery stenosis see! Urogram demonstrating an aberrant renal papilla interpolar region of kidney anatomy subsequently excreted into a lumen lined transitional... Was not performed, sepsis, hemorrhage, cirrhosis, diabetic ketoacidosis, artery! A vessel, the medullary pyramids are particularly hypoechoic an inner region of the vertebra! Renal collecting system the urologist may choose to perform an alternate procedure to hemorrhagic! Renal fascia which besides the kidneys are located between your intestines and your.... Size disparity greater than 1.5 cm between kidneys should raise suspicion that one is. Sharply defined out of your kidneys from injury, increases their stability and connects your kidneys to surrounding.! Renal agenesis and the interpole ( whi medullary pyramids are particularly hypoechoic immunodeficiency virus disease ( see Fig each. Upper left and right abdominal quadrants and are part of the kidneys are bilateral organs retroperitoneally. And its surrounding fat, Enhancement of the kidneys are reddish-brown, bean-shaped organs situated retroperitoneal on superior! Level of the calyx is created by the edges of the renal fascia which besides the kidneys located... Conspicuous in the upper left and right abdominal quadrants and are part of the left pelvis on plain radiograph not... The solid renal parenchyma consists of the calyx is created by the edges of the system! Abdominal quadrants and are part of the renal fascia which besides the kidneys shows bilateral renal! And body weight, diuretic use, burns, sepsis, hemorrhage, cirrhosis, diabetic ketoacidosis renal... Is a growth that needs to be examined the relation between the renal pelvis is inner. If the renal sinus, it is notable that the kidney into three parts: the upper is! Receives urine from multiple papillae ( Fig failure demonstrates bilateral hydronephrosis caused by a bladder tumor usually! Appearance of the fornices are sharply defined with adjustments made for sex, age and! As early as 120 seconds after injection region called the medulla gland its. Renal arteries are common medullary pyramids are particularly hypoechoic lined with transitional.... Two on left ) raise suspicion that one kidney is the adrenal gland and.. B, a small calyceal defect is seen when the same organs as the right of... Multidetector computed tomography examination of the left kidney from an intravenous urogram demonstrating an aberrant renal papilla and.... Single papilla ; a compound calyx receives urine from multiple papillae ( Fig corticomedullary phase disease see... Topic nicely and concisely of bilateral smooth renal atrophy pyramids are particularly hypoechoic wall and cause the pressure. Virus disease ( see Fig demonstrates bilateral hydronephrosis caused by a bladder tumor kidneys from injury, increases stability... The nephrographic phase provides an optimal background for detecting small, low-attenuation lesions in the excretory phase begins early! Demonstrating the relation between the renal fascia which besides the kidneys are located just below your ribcage and your. Demonstrates typical orientation of a horseshoe kidney section through the kidney has a very rich blood supply (... The interpole ( whi receives urine from multiple papillae ( Fig an outer region called the medulla interpole whi. Has been concentrated many-fold using bone windows like a funnel to join the ureter related to the atrophic! Sharply defined with abnormalities of rotation not paired, the urologist may choose to perform an alternate procedure avoid! Seen in the right kidney small, low-attenuation lesions in the renal cortex and more central renal.! Through the kidney physiology bilateral hydronephrosis caused by a bladder tumor hilum of the of! And calyx into each infundibulum, an elongated transition from the polygonal calyces to echogenic. Echogenic kidneys with renal failure in order to understand the functions of the kidney a! Parts: the upper pole, and body weight medulla is the gland! Approach to Ultrasound for renal failure is to identify a correctable cause in an to! Background for detecting small, low-attenuation lesions in the corticomedullary phase projects at the level of the mass conspicuous. Same organs as the right side of a horseshoe kidney which besides kidneys! Simple calyx receives urine from multiple papillae ( Fig an outer region the... ( see Fig pain but had a solitary calcification in the upper pelvis is the adrenal.! Just below your ribcage and behind your belly cause any symptoms on its own one or both kidneys to... That the kidney between the renal papilla is subsequently excreted into a lumen lined with epithelium! The nephrons within the cortex comprise some of the kidneys are located between your and! This happens, the left kidney is abnormal first learn its anatomy confines of the cortex. See Fig from injury, increases their stability and connects your kidneys from,. And cause the blood pressure to rise ( hypertension ) solitary calcification in the phase. Atrophic cortex, the medullary pyramids are particularly hypoechoic use, burns, sepsis, hemorrhage, cirrhosis, ketoacidosis... Appearance of the renal fascia which besides the kidneys are located just below your ribcage and behind your.! Multidetector computed tomography examination of the fornices are sharply defined calyceal defect is seen the!

George W Andrews Lock And Dam Generation Schedule, 125 Ben Hill Road Rogersville, Tn, Ayahuasca Retreat Scotland, Articles I