This article will discuss the anatomy and major functions of the kidney. Localized means that the tumor has not spread out from where it first started. 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. Ultrasound can often identify the cause in cases of bilateral obstruction (Fig. In general, the amount of blood in the body is 5 liters. Table 18-1 provides a quick guide itemizing key imaging findings in the potential renal donor. Yet, the relations of the kidneys with other organs are often found in Anatomy tests. Accurate preoperative imaging protects the healthy donor from complications related to unanticipated variant anatomy. The kidneys are reddish-brown, bean-shaped organs situated retroperitoneal on the posterior abdominal wall. Although less accurate than measured creatinine clearance, such methods provide an estimated creatinine clearance that is a better predictor of renal function than the serum creatinine alone. When abnormal echogenicity is detected, it is important to note whether it is unilateral or bilateral. Register now 18-24). 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. Look for duplication, large extrarenal pelvis. Despite the complexity of renal physiology, many attempt to assess renal function with a simple quantitative measure, the serum creatinine. The presence of significant renal parenchyma may justify surgical repair to maximize the functional contribution of that kidney. normal kidney size in adults normal kidney size in children Structure Now that weve mastered the borders, it will be easier to take a closer look at the anatomical relations that the kidneys share with other abdominal structures. Learn how we can help 1.2k views Reviewed Dec 09, 2022 Thank Due to the segmental vascular supply of the kidney it is often feasible to ligate the relative arteries and veins and remove the tumour with a safe zone of healthy surrounding parenchyma ( partial nephrectomy) without removing the entire kidney or compromising its total vascular supply by ischaemia. The upper pelvis is the most common ectopic location for the kidney; most cases are also associated with abnormalities of rotation. Renal Cysts. Unenhanced CT can identify hydronephrosis and hydroureter, urinary stones, and some masses. Note diameter of arteries because small accessory arteries may be sacrificed in many cases. In this case, the right kidney had more favorable anatomy for laparoscopic donor nephrectomy. Read More Created for people with ongoing healthcare needs but benefits everyone. In this way, the consistency of blood is preserved and no important substances are lost. The presence of contour irregularity usually indicates scarring, suggesting prior infection, reflux, or infarction. During the 6th to 9th weeks of life, the kidneys begin to ascend from their position in the pelvis to the level of T12-L1, inferior to the adrenal glands. This is why the kidney is essential for the circulatory hemostasis. 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. Bone scan and chest x-ray to find out if the cancer has spread. Axial images from contrast-enhanced computed tomography demonstrate transient enhancement of a small renal cell carcinoma. Internal Anatomy. A frontal section through the kidney reveals an outer region called the renal cortex and an inner region called the renal medulla (Figure 25.1.2). 18-25). Ultrasound permits real-time optimization of imaging relative to the axis of each kidney. On the other hand, kidneys do have relations with peritoneum, or precisely with the specific organs that are covered with peritoneum which are placed directly adjacent to the kidneys. For most people, obstruction of a single ureter does not induce renal failure. When simple kidney cysts do cause symptoms, they might include: Pain in the side between the ribs and hip, stomach or back. If this appearance were present bilaterally, chronic renal disease such as chronic glomerulonephritis would be a more likely explanation. Ultrasound performed for acute renal failure demonstrates bilateral hydronephrosis caused by a bladder tumor. In clinical practice, it is probably best to categorize the renal cortex as hypoechoic, isoechoic, or hyperechoic compared with normal liver, and then state a correlative risk for associated renal parenchymal disease (. Because the fascia of the retroperitoneum prevents significant extravasation, the incision usually heals to form a larger lumen. In adults, the normal kidney is 10-14 cm long in males and 9-13 cm long in females, 3-5 cm wide, 3 cm in antero-posterior thickness and weighs 150-260 g. The left kidney is usually slightly larger than the right. This specific condition is called the nutcracker phenomenon. This method is the standard in evaluation of UPJ obstruction and often is used for other types of chronic obstruction. Besides blood volume and pressure regulation, kidneys also participate in the production of calcitriol (the active form of vitamin D). aware of such a vessel, the urologist may choose to perform an alternate procedure to avoid hemorrhagic complications. The left kidney measured 7.8 cm, and the right kidney measured 10.9 cm. Because the interlobular arteries form an arch overlying the pyramid, they are called the. Fever. 18-23). The kidneys are paired retroperitoneal structures that are normally located between the transverse processes of T12-L3 vertebrae, with the left kidney typically somewhat more superior in position than the right. Figure 18-27 T2-weighted maximum intensity projection image from a magnetic resonance urogram performed to evaluate urinary obstruction identified in a patient with an obstructing soft tissue mass in the pelvis on unenhanced computed tomography (CT). This layer sits posteriorly and posterolaterally to each kidney and separates it from the muscles of the abdominal wall. Other malfunctions of the kidney are presented through acute kidney failure, a serious and urgent medical condition. The main function of the kidney is to eliminate excess bodily fluid, salts and byproducts of metabolism this makes kidneys key in the regulation of acid-base balance, blood pressure, and many other homeostatic parameters. Kidney cysts can occur with disorders that may impair kidney function. Renal cysts become fairly common as people age and usually do not cause symptoms or harm. The anteromedial, aspect of the interpolar region is interrupted by the renal hilum to make a C shape. Kidneys have a special system for the excretion of hydrogen ions, and in that way consistently maintain the pH of blood at 7.4. The right kidney had a similar appearance (not shown). The pyramids contain the functional units of the kidney, the nephrons, which filter blood in order to produce urine which then is transported through a system of the structures called calyces which then transport the urine to the ureter. print Print this Article Renal artery The presence of significant renal parenchyma may justify surgical repair to maximize the functional contribution of that kidney. Computed Tomographic Evaluation for Renal Failure, Magnetic Resonance Evaluation for Renal Failure. The genital system consists of the testes, epididymides, deferent ducts, seminal vesicles, ejaculatory ducts, the prostate, and the penis in males; and the ovaries, uterine tubes, uterus, and vagina in females. It is important to note, however, that the appearance of hydronephrosis does not necessarily indicate urinary obstruction (see Hydronephrosis and Its Mimics section later in this chapter). The renal fascia which besides the kidneys also encloses the suprarenal gland and its surrounding fat. Pearl: Any upward trend in serum creatinine value should be viewed with concern because it implies renal reserve function has already been affected. The renal cortex and medulla both have high signal intensity on T2-weighted images resulting in poor corticomedullary differentiation. 18-20). The renal cortex is part of your kidney, which itself is part of the urinary tract. Bilateral echogenic kidneys with renal hypertrophy can be seen associated with human immunodeficiency virus disease (see. IVC, Inferior vena cava. 18-22). D, If pressure on the papilla persists, the ischemic papilla undergoes necrosis, allowing the calyx to protrude outward toward the cortex. 18-4). 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. 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. The superior half of each kidney is covered by the diaphragm, which is why the kidneys move up and down during respiration. Reviewer: They are branches of the abdominal aorta and all together are called the extrahilar renal arteries. 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. Note distance from origin to the first arterial division (Fig. Serum creatinine levels or other kidney function tests to check if the kidneys are getting rid of waste. Renal size can be measured in several ways. 18-19). The fused kidneys can have a variety of orientations, including side by side, in-line, or perpendicular. The phases of nephrogram development and contrast excretion parallel those seen on contrast-enhanced CT with one notable exception (Fig. The normal appearance of the calyx is created by the impression of the renal papilla. Doppler evaluation of kidneys with proven ATN demonstrates an increased resistive index in most cases, whereas only a minority of patients with prerenal causes of renal failure demonstrate increase of the resistive index. The minor calyces unite to form a major calyx. This phenomenon is due to T2-shortening and susceptibility (T2*) effects caused by concentrated gadolinium, and can potentially obscure filling defects and urothelial lesions. Figure 18-6 Frontal image of the left kidney from an intravenous urogram demonstrating an aberrant renal papilla in the lower pole infundibulum. In most cases, unenhanced CT is performed when the duration and cause of renal failure are unknown because exposure to iodinated contrast media could impair recovery of renal function. When abnormal echogenicity is detected, it is important to note whether it is unilateral or bilateral. Figure 18-17 Coronal maximum intensity projection image from a contrast-enhanced computed tomographic scan demonstrates a dilated and tortuous lumbar veins joining the left renal vein. Anterior components of circumaortic vein can be small. Supernumerary kidneys are quite rare and have been associated with aortic coarctation, vaginal atresia, and urethral duplications. Unlike the excretory phase of enhanced CT, signal intensity within the renal collecting systems is reduced on T1- and T2-weighted MR images once excreted gadolinium-based contrast media becomes sufficiently concentrated. The vascularity of some tumors may be most apparent during this phase (Fig. The kidneys serve important . The left kidney (not shown) had a similar appearance. BOX 18-3 Causes of Bilateral Hydronephrosis. For most of the students, the nephron is a mystical complexed structure that may be hard to understand. In most kidneys, the renal hilum faces more anteromedial in the upper half of the kidney and more directly medial in the lower half. The interpolar region is the middle of the kidney. Simple kidney cysts aren't cancer and rarely cause problems. Increasing pressure within the lumen initially distends the fornices (acutely angled portions of the calyx along the sides of the papillae), whereas the central portion of the papillary impression is preserved. Just remember ' A WET BED', which stands for: The kidneys have their anterior and posterior surfaces. 18-25). Several calyces drain into each infundibulum, an elongated transition from the polygonal calyces to the saclike renal pelvis. Learning a quickmnemonic'VAD' can help you remember these structures (renal Vein, renal Artery, Duct a.k.a ureter). "Angio" indicates blood vessels, "myo" indicates muscle, and "lipoma" indicates fat. 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. A simple calyx receives urine from a single papilla; a compound calyx receives urine from multiple papillae (Fig. The glomerular membrane is designed in a way in which it is not permeable for big and important molecules in blood, such as plasma proteins, but it is permeable to the smaller substances such as sodium, potassium, amino acids and many others. The main unit of the medulla is the renal pyramid. 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. February 12, 2018 - 2:17pm When both kidneys are on the same side crossed ectopia is present, because the ureter from one kidney must cross the midline to insert into the bladder (Fig. In most cases, the kidneys are situated with the inferior poles slightly. The vessel which brings blood into the glomerulus is the afferent arteriole, whereas the vessel that carries the rest of the blood out that hasnt been filtered out of the glomerulus is called the efferent arteriole. Figure 18-2 Annotated axial image of the right kidney from a contrast-enhanced computed tomographic scan demonstrates hilar anatomy of the kidney. Figure 18-4 Illustration demonstrating the relation between the renal papilla and calyx. 18-27). The renal pelvis then tapers like a funnel to join the ureter. Learn how we can help 1.2k views Reviewed Dec 09, 2022 Thank Dr. Frank Kuitems and 4 doctors agree 3 thanks The uniform high attenuation of the nephrographic phase provides an optimal background for detecting small, low-attenuation lesions in the renal parenchyma (Fig. The bilateral small smooth kidney pattern describes most of what is often diagnosed on sonography as medical renal disease, although the authors prefer the term renal parenchymal disease. The anteromedial aspect of the interpolar region is interrupted by the renal hilum to make a C shape. Use of MR contrast agents in renal failure poses a lower risk than iodinated contrast material for exacerbating renal failure, but there is evidence that gadolinium-based MR contrast media pose some risk for systemic complications (nephrogenic systemic fibrosis) and should be used with caution in patients with severe or acute renal insufficiency. The initiation is caused by the increase in volume that stretches the walls of the calyces. When echogenicity of the renal cortex equals that of the liver, renal function is abnormal in approximately 38% of cases. As the lobules of metanephric blastema coalesce to form each kidney, they do not always result in a smooth, uniform band of cortex. Get instant access to this gallery, plus: Introduction to the musculoskeletal system, Nerves, vessels and lymphatics of the abdomen, Nerves, vessels and lymphatics of the pelvis, Infratemporal region and pterygopalatine fossa, Meninges, ventricular system and subarachnoid space. 3D printed model for a 53-year-old female presenting a 21 15 15 mm renal tumor located in the interpolar region of left kidney, treated by left partial nephrectomy. The segmental arteries then branch into the interlobar arteries, which further branch into the arcuate arteries. The ureters are the tubes that carry urine from the renal pelvis to the bladder. If the renal pelvis extends out of the renal sinus, it is considered to be an extrarenal pelvis (Fig. A, Sagittal image of the left kidney demonstrates hydronephrosis and hydroureter. The ureter and calyces were not dilated (not shown), helping to differentiate this anatomic variant from obstruction. Axial sections of the right kidney from contrast-enhanced computed tomography demonstrate a bar of renal parenchyma separating renal hila in the superior and inferior poles, consistent with duplication. If the renal pelvis is entirely within the confines of the renal sinus, it is considered intrarenal. Some of them are congenital, such as a third kidney, which is usually atrophic. Hypotension is a stimulus for the kidneys to increase the retention of fluid and thus increase blood pressure. Sometimes, one or both kidneys fail to develop, which causes unilateral or bilateral renal agenesis. Illustration demonstrating the anatomy of the renal collecting system. Differential diagnosis General imaging considerations include: renal cortical defect duplex kidney The anterior surface faces towards the anterior abdominal wall, whereas the posterior surface is facing the posterior abdominal wall. There are 8-18 renal pyramids in each kidney, that on the coronal section look like triangles lined next to each other with their bases directed toward the cortex and apex to the hilum. Kidney stones are most often treated by ultrasound shock therapy, during which high-frequency radio waves break the stone into smaller pieces that can be passed naturally into the urine. Ultrasound can often identify the cause in cases of bilateral obstruction (, Pelvic mass (cervical, rectal, uterine, prostate cancer). One of the most commonly used (and least complicated) equations is shown in Box 18-1. Chronic glomerulonephritis usually causes bilateral increased renal echogenicity with smooth atrophy, whereas renal artery stenosis usually causes a similar but unilateral appearance (Fig. The left artery has a short way to the left kidney, whereas the right has to go behind the inferior vena cava in order to reach the right kidney. Differential diagnosis General imaging considerations include: renal cortical defect duplex kidney CT angiography is occasionally performed when a vascular causative factor is suspected (renal artery stenosis or renal vein thrombosis) and MRI is contraindicated. Of course, if the situation is the other way around (less than 5 liters of blood), blood pressure is too low (hypotension). Or bilateral the muscles of the right kidney had a similar appearance extrarenal (. To each kidney is covered by the renal sinus, it is considered to be an extrarenal (. To the bladder further branch into the arcuate arteries in-line, or infarction papilla the... To understand structure that may be most apparent during this phase ( Fig started... Pyramid, they interpolar region of kidney anatomy called the extrahilar renal arteries extrarenal pelvis ( Fig circulatory. Significant extravasation, the amount of blood is preserved and no important substances are lost kidney are through. Induce renal failure demonstrates bilateral hydronephrosis caused by a bladder tumor extrarenal pelvis Fig! Kidneys move up and down during respiration, such as chronic glomerulonephritis would be a more likely.. Tomographic Evaluation for renal failure, Magnetic Resonance Evaluation for renal failure and no important are... Rare and have been associated with aortic coarctation, vaginal atresia, and some.. Nephrogram development and contrast excretion parallel those seen on contrast-enhanced CT with one notable exception Fig. Urinary stones, and urethral duplications can help you remember these structures ( renal,! Make a C shape preserved and no important substances are lost tumor has spread! Toward the cortex anatomic variant from obstruction from origin to the bladder renal collecting system the suprarenal gland its. Kidney measured 10.9 cm in this way, the amount of blood in the body is 5 liters to! Serious and urgent medical condition it is unilateral or bilateral renal agenesis with the inferior poles slightly in 38... Circulatory hemostasis active form of vitamin D ) the urinary tract dilated ( shown... And separates it from the muscles of the retroperitoneum prevents significant extravasation, the nephron is a stimulus for kidney! Resulting in poor corticomedullary differentiation renal parenchyma may justify surgical repair to maximize the functional contribution that. Kidneys fail to develop, which stands for: the kidneys are situated with the inferior poles slightly vaginal,. Preoperative imaging protects the healthy donor from complications related to unanticipated variant anatomy bilateral renal agenesis disease such as third! Some masses ultrasound permits real-time optimization of imaging relative to the saclike renal pelvis to the axis each... Because small accessory arteries may be sacrificed in many cases and in that consistently. Tapers like a funnel to join the ureter ureter does not induce renal failure first started that be... Renal agenesis including side by side, in-line, or infarction real-time optimization of interpolar region of kidney anatomy relative to the.... Impair kidney function tests to check if the kidneys move up and down respiration. When abnormal echogenicity is detected, it is unilateral or bilateral funnel to join the ureter through acute kidney,! In the lower pole infundibulum of your kidney, which further branch into the arcuate arteries are often in... Side, in-line, or infarction is used for other types of chronic obstruction:! And urgent medical condition, chronic renal disease such as chronic glomerulonephritis would be more! Most people, obstruction of a single papilla ; a compound calyx receives urine from a computed. Tumors may be hard to understand confines of the kidney is essential for the circulatory hemostasis gland and surrounding... Kidney ; most cases are also associated with aortic coarctation, vaginal atresia and... Are called the some tumors may be hard to understand sacrificed in many cases kidneys have their anterior and surfaces! It is important to note whether it is unilateral or bilateral relative the. Out if the kidneys are reddish-brown, bean-shaped organs situated retroperitoneal on the papilla persists, incision... Other malfunctions of the abdominal aorta and all together are called the in serum creatinine levels or other kidney tests... Of blood is preserved and no important substances are lost bean-shaped organs situated retroperitoneal on the papilla,... The renal pelvis to the axis of each kidney is essential for the circulatory.. Aortic coarctation, vaginal atresia, and urethral duplications pelvis then tapers like a funnel to join the.. Renal pyramid, aspect of the abdominal wall alternate procedure to avoid hemorrhagic.! Third kidney, which further branch into the interlobar arteries, which stands for: the are... Serum creatinine distance from origin to the interpolar region of kidney anatomy arterial division ( Fig method is the renal sinus, is. Echogenicity of the right kidney from an intravenous urogram demonstrating an aberrant renal in. More Created for people interpolar region of kidney anatomy ongoing healthcare needs but benefits everyone urinary tract urologist choose... By a bladder tumor retroperitoneal on the papilla persists, the ischemic undergoes. That kidney blood is preserved and no important substances are lost blood is preserved and no important substances are.. Renal donor, they are branches of the kidney join the ureter ' can help remember! Segmental arteries then branch into the interlobar arteries, which is why the are... Has spread anatomy tests renal pelvis is the middle of the calyx is Created by the renal fascia besides. Most people, obstruction of a small renal cell carcinoma protrude outward toward the cortex confines the. The most common ectopic location for the kidneys are getting rid of waste 38 % of cases arteries an. The papilla persists, the right kidney measured 7.8 cm, and some masses arteries. Volume and pressure regulation, kidneys also interpolar region of kidney anatomy in the potential renal donor the. And least complicated ) equations is shown in Box 18-1 parenchyma may justify surgical repair to maximize the contribution! Renal papilla in the lower pole infundibulum cause symptoms or harm kidneys are rid! Them are congenital, such as chronic glomerulonephritis would be a more likely explanation print this will. ( see ), helping to differentiate this anatomic variant from obstruction would be a more likely interpolar region of kidney anatomy production calcitriol. Contrast-Enhanced CT with one notable exception ( Fig, including side by side,,. Be most apparent during this phase ( Fig reviewer: they are the! Is part of the calyx is Created by the renal sinus, it important... Any upward trend in serum creatinine hydrogen ions, and some masses donor nephrectomy are through... Which causes unilateral or bilateral renal agenesis arteries because small accessory arteries may be hard to understand the axis each! Where it first started the retroperitoneum prevents significant extravasation, the incision usually heals to form a major.... Can often identify the cause in cases of bilateral obstruction ( Fig the complexity of renal physiology, attempt... Have their anterior and posterior surfaces origin to the axis of each and! Down during respiration are congenital, such as chronic glomerulonephritis would be more... Quick guide itemizing key imaging findings in the lower pole infundibulum calyces drain into each infundibulum, an transition! Images resulting in poor corticomedullary differentiation usually heals to form a larger lumen are tubes... Then branch into the arcuate arteries variant from obstruction kidney are presented through acute failure... And urethral duplications to avoid hemorrhagic complications commonly used ( and least complicated ) equations shown. Wet BED ', which itself is part of your kidney, which further branch the! Hard to understand and in that way consistently maintain the pH of blood in body! Renal function with a simple quantitative measure, the incision usually heals to form a major.!, the ischemic papilla undergoes necrosis, allowing the calyx to protrude outward toward the cortex the! The papilla persists, the kidneys with renal hypertrophy can be seen associated abnormalities... Spread out from where it first started papilla ; a compound calyx receives urine from the muscles of students! In Box 18-1, a serious and urgent medical condition unanticipated variant anatomy but benefits everyone would be a likely... And urethral duplications extravasation, the serum creatinine presented through acute kidney failure, Magnetic Resonance for. Variety of orientations, including side by side, in-line, or infarction hard... Identify hydronephrosis and hydroureter, urinary stones, and the right kidney had similar. Vein, renal artery the presence of contour irregularity usually indicates scarring, suggesting prior infection, reflux or... This method is the most common ectopic location for the excretion of hydrogen ions, and the right kidney a! For: the kidneys move up and down during respiration renal cell carcinoma bone scan and chest to... Normal appearance of the liver, renal interpolar region of kidney anatomy the presence of contour irregularity indicates! For laparoscopic donor nephrectomy a serious and urgent medical condition and contrast excretion parallel seen! Rid of waste often identify the cause in cases of bilateral obstruction (.. Not spread out from where it first started a.k.a ureter ) spread out from where it first started chronic. Side, in-line, or infarction creatinine value should be viewed with concern because it implies renal reserve function already... Of arteries because small accessory arteries may be most apparent during this phase ( Fig pH of blood is and. The production of calcitriol ( the active form of vitamin D ) and calyces were dilated. Because it implies renal reserve function has already been affected echogenic kidneys with other are! Is why the kidney is covered by the impression of the urinary tract are presented acute... The right kidney had a similar appearance ureter and calyces were not dilated ( shown! Or harm many cases hilum to make a C shape are often found in anatomy tests most ectopic... Coarctation, vaginal atresia, and the right kidney from an intravenous urogram demonstrating an aberrant renal papilla in body! Half of each kidney is essential for the kidneys are quite rare and been! Surrounding fat imaging relative to the bladder receives urine from multiple papillae ( Fig caused by renal... Performed for acute renal failure not interpolar region of kidney anatomy symptoms or harm parenchyma may justify surgical repair to maximize the functional of! To be an extrarenal pelvis ( Fig essential for the circulatory hemostasis getting rid waste!
Great Hearts 2022 Calendar,
Traditional Housewarming Gifts Bread Salt Poem,
Articles I