DR. ANUBHAV KAMAL
DY PATIL MEDICAL COLLEGE, PUNE
Most patients tend to present between 30-60 years of age.
Male : Female (3 : 1)
More common in Asians and whites than in Native Mediterranean
Americans, Africans, African Americans.
Geography (stones are more common in hot and dry areas).
Diet and Hereditary also appears to be factor.
Diet – Vitamin A deficiency causes desquamation of epithelium
which acts as a nidus for stone formation.
Climate – In hot climate, urinary solutes will increase with decrease
in colloids, which leads to chelation of solutes with calcium forming
a nidus for stone.
Citrate level in urine (300-900 mg/24 hours) maintains the calcium
phosphate and carbonate in soluble state. So any decrease in
citrate level in urine causes stone formation.
Infection – Urea splitting organisms (E.coli, Staphylococcus, Proteus)
Prolonged immobilization – causes decalcification of bones so
hypercalciuria leading to stone formation.
Hyperparathyroidism causes hypercalciuria
Hyperoxaluria – result of altered glycine metabolism.
Renal tubular acidosis
Stasis/Slow urine flow – due to obstruction to urine flow (e.g.
Stages of stone formation
Calcium Oxalate Stones
80% of kidney stones contain
White, hard, radiopaque
Calcium PO4: staghorn in renal
Calcium oxalate: present in
Called Mulberry stone (brown)
with sharp projections.
Either be Calcium phosphate
(magnesium or ammonium)
Occurs in infection
Smooth and white color
In alkaline urine, it enlarges rapidly,
filling renal calyces and taking
their shape (STAGHORN
Uric Acid Stones
8% of renal stones contain uric
associated with hyperuricemia
(with or without gout)
Small, friable, yellowish
May form staghorn
Radiolucent (plain x-rays
Occur in Cystinuria (defective
resorption of cystine from renal
Form in acidic urine (soluble in
Radiopaque (contains sulphur)
Smooth, Brick Red
Deficiency of xanthine oxidase
Compound of magnesium,
ammonium phosphate mixed with
associated with chronic UTI
Occurs in presence of ammonia
and urea splitting organisms in
urine (e.g. Proteus, Klebsiella)
Stone occupying the renal pelvis
Triple phosphate stone
White in color, soft, smooth occurs
in pre-existing infection.
Classical features of renal colic (or ureteric colic)
Sudden severe pain – caused by stones in the kidney, renal pelvis or ureter,
causing dilatation, stretching and spasm of the ureter.
Pain starts at the level of the costovertebral angle (but sometimes lower)
and moves to the groin, with tenderness of the loin or renal angle,
sometimes with hematuria.
If the stone is high and distends the renal capsule then pain will be in the
flank but as it moves down pain will move anteriorly and down towards the
A stone that is moving is often more painful than a stone that is static.
The pain radiates down to the testis, scrotum, labia or anterior thigh.
D/D on basis of site of pain
Pyelonephritis: very high temperature. Pain is unlikely to radiate to the groin.
Perforated peptic ulcer.
Epididymo-orchitis or torsion of testis: very tender testis.
Sinister causes of back pain: usually tender over vertebrae.
Drug addiction: There are reports of people with fictitious stories of renal
colic, designed to obtain an injection of pethidine.
D/D of Radiopaque Shadow
Calcified lumbar or mesenteric LN
Gallstone (10% radiopaque)
Concretion in appendix
Ossified tip of 12th ribs
Chip fracture of transverse process of vertebra
Calcified renal tuberculosis
Calcified suprarenal gland
Foreign body in alimentary canal
Caliceal calculi that are non-obstructing are usually asymptomatic.
Patients with small caliceal calculi may still have gross or
microscopic hematuria and may have colic symptoms despite the
lack of imaging findings suggestive of obstruction.
Calculi causing Hydronephrosis
Hydronephrosis is dilatation of the renal pelvis and calyces.
It can be caused by obstruction of the ureters or bladder outlet. Hydronephrosis can also result from
reflux (retrograde leakage of urine from the bladder up the ureters to the renal pelvis.
Ureter has 3 Constrictions:
When it crosses external iliac vessel
Always of Renal Origin
Commonly of elongated shape
Can get impacted at 3 constrictions of
Colicky Pain (from loin to tip genitalia) along
Hematuria, dysuria, frequency, strangury
Tenderness in iliac fossa
Primary vesical calculus:
occurs in sterile urine
Comes down from kidney through ureter and
gets enlarged in bladder (usually oxalate
Can irritate bladder mucosa causing
Secondary vesical calculus:
Occurs in presence of infection (commonest
Usually phosphate stone, occurs in bladder
Same as that of Renal Calculus
Diverticula bladder: which lead to
stagnation of urine superadded
infection stone formation
Bladder stones generally form in the
bladder outflow obstruction
neurogenic bladder (loss of bladder
function due to spinal cord
Those with bladder wall
those with recurrent urinary
infections are also at higher risk of
forming bladder stones.
When seen on an abdominal/pelvic
X-ray they are often multiple and
Note that this stone has a faint
longitudinal lucency which is the
nidus around which the stone
Jackstone calculi resembles toy
composed of calcium oxalate
dense central core and radiating
light brown with dark patches and
are usually described to occur in
the urinary bladder and rarely in
the upper urinary tract.
Frequency more during day than night, because during day, due to
ambulation stone comes in contact with trigone of the bladder and
Pain – referred to tip of penis or labia.
Burning micturition and fever.
Refers to renal parenchymal calcification.
The calcification may be dystrophic or
With dystrophic calcification, there is
deposition of calcium in necrotic tissue.
This type of parenchymal calcification
occurs in tumors, abscesses, and
Metastatic nephrocalcinosis occurs most
often with hypercalcemic states caused
by hyperparathyroidism, renal tubular
acidosis, and renal failure.
Metastatic nephrocalcinosis can be
further categorized by the location of
calcium deposition as cortical or
Causes of Nephrocalcinosis
Causes of cortical nephrocalcinosis include
acute cortical necrosis
chronic hypercalcemic states
ethylene glycol poisoning, sickle cell disease, and
rejected renal transplants
Causes of medullary nephrocalcinosis include
renal tubular acidosis (20%)
medullary sponge kidney
bone metastases, chronic pyelonephritis, cushing’s
hyperthyroidism, malignancy, renal papillary necrosis,
sarcoidosis, sickle cell disease, vitamin D excess, and
Calcification within venous structures.
Common in the pelvis where they may
mimic ureteric calculi, and are also
encountered frequently in venous
Round in shape (but not always)
of a similar size that would correspond
to the diameter of pelvic veins
look like a ring of bone
tend to occur laterally around the
appear as focal calcifications, often
with radiolucent centers
retroperitoneal organs such as the
pancreas which only become
visible when calcified.
Pancreatic calcification is a feature
of chronic pancreatitis.
Adrenal (suprarenal) calcification
is an uncommon finding and is
usually incidental. Most often it is
considered a result of previous
haemorrhage or tuberculosis.
Gallstones (10% radiopaque)
Radiopaque lucency in the RUQ and
presents with typical laminated
Note anterior location on lateral
Gallstones have a variable
position depending on the position
of the gallbladder and may be
mistaken for renal stones
Unlike renal stones they are often
rounded and cluster together
Small calcified stone within the
appendix, and is seen in the right
Calcification of arteries seen on xrays is a sign of more generalised
calcification seen on an
abdominal X-ray reveals an
Typical appearance of calcified
Note the outward bulging of the
Genitourinary tract tuberculosis.
Lobar calcification in a large
destroyed right kidney in a patient
with renal tuberculosis. Note the
involvement of the right ureter
The calcified arrowed structures are likely
to be calcified injection sites.
The calcified lesions at the bottom of the
image are scrotal calculi which are also
known as a fibrinoid loose bodies or
Scrotoliths or scrotal pearls are benign
incidental extra testicular macrocalcifcations within the scrotum. They
frequently occupy the potential space of
the tunica vaginalis or sinus of the
epidydimis. They are usually of no clinical
micro trauma / repetitive trauma to
region - e.g. mountain bikers
prior torsion appendix of testis
CT Scan Renal Stone
On CT almost all stones are opaque, but vary
considerably in density.
calcium oxalate +/- calcium phosphate: 400600HU
struvite (triple phosphate): usually opaque but
uric acid: 100 - 200HU
HIV medication related stones (indinavir)
difficult to visualize
Collimation 5-7 mm
Pitch of 1.5-2
Slice reconstruction of 3 mm
Avoidance of an injection of contrast
Sensitivity 94%, specificity 97%
Alternate diagnosis in patients with acute
Flush Therapy – for low ureteric stones (drinking 2-3 litres of
Inj. Frusemide 60-80 mg
Anti-spasmodic agents to relieve the pain.
Most of the Stones can be removed without open Sx by:
ESWL - Extracorporeal shock wave lithotripsy (ESWL). This uses highenergy shock waves which are focused on to the stones from a
machine outside the body to break up stones. You then pass out the
tiny broken fragments when you pass urine.
PCNL - Percutaneous nephrolithotomy (PCNL) is used for stones not
suitable for ESWL. A nephroscope is passed through the skin and into
the kidney. The stone is broken up and the fragments of stone are
removed via the nephroscope. This procedure is usually done under
URS - In this procedure, a thin ureteroscope is passed up into the
ureter via the urethra and bladder. Once the stone is seen, a laser
(or basket) is used to break up the stone.
For stones in extrarenal pelvis
Posterior subcostal incision
Renal pelvis is opened, stone is
Drain is placed and wound is
Incision on hilum over renal sinus
To remove stones from pelvis and
Incision behind the most convex surface
(Brodel’s line) and stone is removed
incision both over the kidney and pelvis.
Often done for Staghorn Calculus.
done when there are multiple calculi
occupying a pole or when there’s
damage to calyx
Abdominal images containing a
pregnancy are rarely seen today.