Anatomy & Physiology KidneyAlmas khan

RadiographerKhorfakkhan Hospital

Introduction

Anatomy – Vascular FunctionDiagnostic modalities Contra indications CT anatomy Contrast protocolTreatments

Location and External Anatomy of Kidneys• Located retroperitoneally• Lateral to ……… vertebrae ?• T12 to L 3 • Average kidney

– 12 cm tall, 6 cm wide, 3 cm thick

• Hilus– On concave surface – Vessels and nerves enter and

exit• Renal capsule surrounds the

kidney

Anatomy of the kidneys• Superficial outer cortex and inner medulla

– The medulla consists of 6-18 renal pyramids– The cortex is composed of roughly 1.25 million nephrons

• Major and minor calyces along with the pelvis drain urine to the ureters

The kidneys are surrounded by three layers of tissue:The renal fascia is a thin, outer layer of fibrous connective tissue that surrounds each kidney (and the attached adrenal gland) and fastens it to surrounding structures.The adipose capsule is a middle layer of adipose (fat) tissue that cushions the kidneys.The renal capsule is an inner fibrous membrane that prevents the entrance of infections.

Functions of the urinary system• Homeostatic regulation of blood plasma– Regulating blood volume and pressure– Regulating plasma ion concentrations– Stabilizing blood pH– Conserving nutrients

• Filter many liters of fluid from blood• Excretion - The removal of organic waste products

from body fluids– Urea– Uric acid– Creatinine

• Elimination - The discharge of waste products into the environment

FunctionThe urinary system helps maintain homeostasis by regulating water balance and by removing harmful substances from the blood.

The blood is filtered by two kidneys, which produce urine, a fluid containing toxic substances and waste products.

From each kidney, the urine flows through a tube, the ureter, to the urinary bladder, where it is stored until it is expelled from the body through another tube, the urethra.

Ureters :- Pair of narrow thick muscular tube.Kidney to the urinary bladder.They lie deep of peritonium.Length – 25 cm , 3 mm diameter.

Urinary bladder:-Muscular reservoir , lies anterior part of pelvis cavity.Capacity of bladder is ……… ?220 ml.

Urethra :- It is the passage through which urine is expelled out from the urinary bladder.

Mechanisms of Urine Production• Filtration - filtrate of

blood leaves kidney capillaries

• Reabsorption – most nutrients, water, and essential ions reclaimed

• Secretion - active process of removing undesirable molecules

Disease of Kidney Conditions

Kidney stones :- (nephrolithiasis): Minerals in urine form crystals (stones), which may grow large enough to block urine flow. It's considered one of the most painful conditions. Most kidney stones pass on their own but some are too large and need to be treated

• Polycystic kidney disease :- A genetic condition resulting in large cysts in both kidneys that impair their function.

• Kidney cancer:- Renal cell carcinoma is the most common cancer affecting the kidney. Smoking is the most common cause of kidney cancer.

Acute renal failure (kidney failure): A sudden worsening in kidney function. Dehydration, a blockage in the urinary tract, or kidney damage can cause acute renal failure, which is usually reversible.

Chronic renal failure:- A permanent partial loss of kidney function. Diabetes and high blood pressure are the most common causes.

Renal cyst :- A benign hollowed-out space in the kidney. Isolated kidney cysts occur in many normal people and almost never impair kidney function.

Kidney tests

• Urinalysis :- A routine test of the urine by a machine looking through a microscope. Urinalysis can help detect infections, inflammation, microscopic bleeding, and kidney damage.

• USG• Kidney biopsy • X-Ray- KUB , IVP• CT and MRI

Ureteroscopy:- …….?An endoscope (flexible tube with a camera on its end) is passed through the urethra into the bladder and ureters.

Treatments providing

Antibiotics :- Treatment giving with antibiotic medicine

Lithotripsy :- …..?kidney stones may be shattered into small pieces done by a machine that projects ultrasound shock waves through the body.

Hemodialysis :- A person with complete kidney failure is connected to a dialysis machine, which filters the blood and returns it to the body. typically done three days per week in people with ESRD. ?

Kidney transplanting :- Transplanting a kidney into a person with ESRD can restore kidney function. A kidney may be transplanted from a living donor, or a recently deceased organ donor.

Contrast administration…. PATIENT PREPARATION Need C.T. SCAN

• Blood urea and Creatinine … ?• History of allergies to drugs• Previous reactions to contrast

media• Asthma• Renal failure or cardiac problems• Pregnancy or breast feeding• Diabetes Patients:- Stopping Metformin ….? If the patient is diabetic it is important

to establish if they are taking Glucophage/Metformin. These patients

are at risk of lactic acidosis following the administration of the IV contrast media. Renal function should be assessed prior to the injection and the following steps taken:

CT KUB

• Time Calculating ……?• Phase One is completed without

contrast and is the KUB portion of this exam assessing for stone disease

• Phase Two is the arterial phase scanning through the kidney with contrast, identifying hypervascular lesions

• Phase Three is the portal venous phase, allowing further characterization

of enhancement kinetics of any lesion

• Phase Four is a delayed scan through the kidneys, ureter, and bladder when the collecting systems and bladder will be fully opacified

Bolus Tracking Protocol for C T Kidney

• CTA Renal Arteries :- 23 sec – 4cc / sec Locator – just above the kidney ROI – Descending Aort

Tips to remember

Patient preparationlab pls request Bun and CreatininDiabetic patient give correct instruction Time Calculating for contrast protocol Educate the patient about Kidney awarness

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