Cross Sectional Anatomy The kidneys hhholdorf This is

Cross Sectional Anatomy The kidneys hhholdorf

This is an image of what?

This is an image of what?

This is an image of what?

Renal Parenchyma

General Stuff �Retroperitoneal �Left higher than the right (Liver on the rt) �Ascends during embryology from the lower abdomen. �Pelvic kidney? �Back pain? Could be your kidney!

Kidney Size �ADULT • 9. 0 to 12. 0 cm in length. • 4. 0 to 5. 0 cm in width. • 2. 5 to 3. 0 cm in height. • Minimum of 1 cm in cortical thickness. �CHILD • 7. 0 to 8. 0 cm in length. �INFANT • 5. 0 to 6. 0 cm in length.

Indications for Exam � � � � Increase in creatinine or BUN levels. Urinary tract infection. Flank pain. Hematuria. Hypertension. Decrease in urine output. Trauma. Evaluate mass from previous medical imaging study (i. e. , CT, MRI, IVP)

LABORATORY VALUES � CREATININE Normal 0. 6 to 1. 2 mg/d. L. A waste product produced from meat protein and normal wear and tear on the muscles in the body. • More specific in determining renal dysfunction than BUN levels. • Elevated in renal failure, chronic nephritis or urinary obstruction. • • � BLOOD UREA NITROGEN Normal 11 to 23 mg/d. L. Produced from the breakdown of food proteins. Elevated in urinary obstruction, renal dysfunction, or dehydration. • Decreased levels associated with over hydration, pregnancy, liver failure, decrease in protein intake, and smoking. • • •

Laboratory Values: Continued � HEMATURIA � Visible or microscopic red blood cells in the urine. � Associated with early renal disease. � PROTEINURIA � Abnormal amount of proteins in the urine. � Associated with nephritis, nephrolithiasis, carcinoma, polycystic disease, hypertension, and diabetes mellitus. � Increases risk of developing progressive renal dysfunction.

Key terms �Dromedary hump cortical bulge on the lateral aspect of the kidney. �fascia fibrous connective membrane of the body that may be separate from other structures. �Fetal lobulation immaturity of renal development resulting in a lobulated renal contour. �Gerota’s fascia protective covering of tissue surrounding each kidney.

Dromedary Hump Kidney

Fetal lobulation variant

�Renal parenchyma the functional tissue of the kidney consisting of the nephrons. �Renin renal enzyme that affects blood pressure.

Renal Parenchyma and relative echogenicity

FUNCTIONS OF THE URINARY SYSTEM Produces urine and erythroprotein. � Influences blood pressure, blood volume, and intake or excretion of salt and water through the renin–angiotensin system. � Regulates serum electrolytes. � Regulates acid–base balance. �

TECHNIQUE PREPARATION • • • Kidneys—patient should be hydrated. Renal vessels—nothing by mouth for 6 to 8 hours before the examination. Bladder—drink 8 to 16 ounces of water 1 hour before the examination.

EXAMINATION TECHNIQUE and imaging optimization �Use the highest-frequency abdominal transducer possible to obtain optimal resolution for penetration depth. � Place gain settings to display the normal adult renal cortex as moderate or low-level echogenicity and the renal sinus as the most echogenic with adjustments to reduce echoes within the vessels.

� Position the focal zone(s) at or below the region of interest. � Sufficient imaging depth to visualize structures posterior to the region of interest. � Harmonic imaging and decreasing the compression (dynamic range) can be used to reduce artifactual echoes within anechoic structures and improve prominence of posterior acoustic shadowing.

� Evaluation and documentation of the superior, inferior, medial, and lateral aspects of each kidney in the coronal or sagittal plane.

�Evaluation and documentation of the superior pole, renal hilum, and inferior pole of each kidney in the transverse plane. �Measurements of maximum length, thickness, and width of each kidney. �Measurement of the cortical thickness of each kidney.

�Evaluation and documentation of the bladder wall. �Prevoid and postvoid bladder volumes may be included. �Kidneys are best evaluated with an empty urinary bladder. �Documentation and measurement of any abnormality in two scanning planes should be included.

PATIENT POSITION �Supine �Right superior pole with intercostal approach �Right inferior pole with subcostal approach

What patient position is this?

�Left posterior oblique (LPO) �Allows bowel to move away from right kidney �Subcostal or intercostal approach

Left Posterior Oblique incorrect

What patient position is this?

Left lateral decubitus �Liver and kidney “fall” from the rib cage �Aids in obese or gassy patients

What patient position is this?

Right posterior oblique (RPO) � Left superior pole with intercostal approach �Posterior subcostal approach for left inferior pole

What patient position is this?

Right lateral decubitus �Left posterior approach with deep inspiration Prone �Demonstrates mid and inferior poles of both kidneys

What patient position is this?

Prone

RAO-Right Anterior Oblique

PHYSIOLOGY The nephron is the basic functional unit of the kidney. • Each kidney contains over one million nephrons. •

The renal Nephron

�ANATOMY �Renal capsule �Fibrous capsule (true capsule) surrounding the cortex �Renal cortex �Outer portion of the kidney

Medulla �Inner portion of the renal parenchyma �Within the medulla lie the renal pyramids �Renal pyramids contain tubules and the loops of Henle

Column of Bertin � Inward extension of the renal cortex between the renal pyramids � Renal sinus � Central portion of the kidney � Contains the major and minor calyces, peripelvic fat, fibrous tissues, arteries, veins, lymphatics, and part of the renal pelvis � Renal hilum � Contains the renal artery, renal vein, and ureter

Column of Bertin between the renal Pyramids

Gerota’s Fascia “C”

Location �Paired bean-shaped structures lying in a sagittal oblique plane in the retroperitoneal cavity. �Located between the first and third lumbar vertebrae. �Superior poles lie more posterior and medial. �Inferior poles lie more anterior and lateral. �Left kidney lies superior to the right kidney.

�Each Kidney Is Located �Anterior to the psoas and quadratus lumborum muscles. �Medial to the transverse abdominus muscle and liver or spleen. �Lateral to the quadratus lumborum muscle.

�Renal Anatomical Variants �Dromedary hump �Cortical bulge on the lateral aspect of the kidney �Demonstrated most often on the left �Asymptomatic Lateral outward cortical bulge � Echogenicity equal to the cortex Carcinoma? � Hematoma?

What is this an image of?

What is this an image of?

�Congenital Anomalies �Agenesis �Absence of the kidney(s)

Renal Agenesis �Unilateral or bilateral Asymptomatic when unilateral � Fatal when bilateral � Associated with genital anomalies Empty renal fossa(e) � Large, contralateral kidney Pelvic kidney? � Surgical removal?

Diagnosis, please.

�Horseshoe kidney

What is this?

Horseshoe kidney

Renal Vasculature

MAIN RENAL ARTERY �The right renal artery arises from the anterolateral aspect of the aorta. The left renal artery arises from the posterolateral aspect of the aorta. � May have multiple ipsilateral arteries

�A single ipsilateral artery may divide into multiple renal arteries at the hilum �Courses posterior to the renal vein �Main renal artery arises 1. 0 -1. 5 cm inferior to the origin of the superior mesenteric artery � Right renal artery is longer than the left renal artery

�Demonstrates low-resistance blood flow �Supplies the kidney, ureter, and adrenal gland �Segmental artery �After entering the renal hilum the artery divides into 4 -5 segmental arteries �Demonstrates low-resistance blood flow

�Interlobar artery �Branch of the segmental artery �Course alongside the renal pyramids �Demonstrates low-resistance blood flow

� Renal Vasculature— � Arcuate artery � Boundary between the cortex and medulla � Branch of the interlobar artery located at the base of the medulla � Arcuate arteries give rise to the interlobular arteries � Demonstrates low-resistance blood flow � Interlobular artery � Branch of the arcuate arteries entering the renal glomeruli

�MAIN RENAL VEIN �Formed from the junction of tributaries in the renal hilum �Courses anterior to the renal artery �Left renal vein receives the left suprarenal and left gonadal vein � Left renal vein is longer than the right renal vein �Dilatation of the left renal vein due to mesenteric compression may be demonstrated

�Ureter Anatomy � 25 – 34 cm long tubular structure connecting the renal pelvis to the urinary bladder. �Coarse vertically with retroperitoneum along the psoas muscles. �Insert posterior and inferiorly at the Trigone of the bladder. �Distal ureter at the trigone considered extraperitoneal.

� � � � � Support Structure of the Kidneys Psoas muscle Major groin muscle Primary flexor of the hip joint Lies posterior to the inferior pole of each kidney Quadratus lumborum muscle Muscle of the posterior abdominal wall Lies posterior and medial to each kidney Transversus abdominus muscle Deepest layer of flat muscles of the anterolateral wall Lies lateral to each kidney Gerota’s fascia Fibrous covering of tissue surrounding each kidney Also known as Gerota’s capsule; renal fascia Perinephric fat Fatty tissue surrounding each kidney Renal capsule Protective connective tissue capsule surrounding each kidney

Gerota’s Fascia “C”

Protocol Right Kidney • Sagittal Mid-Med and Lateral Borders Measure upper pole to lower pole • Doppler Right Renal artery-Nml is low resistant Transverse Mid pole-Measure side to side Upper pole to lower pole Doppler IVC to check for thrombus

Protocol �Left Kidney • Sagittal • Mid-Med Lateral �Measure Upper pole to lower pole �Transverse �Measure mid pole (Lateral side to Medial Side) �Upper pole to lower pole �OTHER �Check bladder

Homework �Locate the following on a cartoon and an ultrasound image: • • • Renal Sinus Column of Bertin Psoas muscle Renal Hilum Perinephric fat Segmental artery Interlobar artery Main Renal Artery Main Renal Vein

List the protocol for a renal exam.

Answer the following either True or False. �The kidneys are retroperitoneal. �Right higher than the left. �Descends during embryology from the upper abdomen.

Which is not an indication for a renal exam? � A. increase in creatinine � B. Decrease in BUN levels � C. Flank Pain. � D. Hematuria � The protective covering of tissue surrounding each kidney is called: � A. parenchyma � B. Renal cortex � C. Gerota’s fascia