KIDNEY, POLYCYSTIC
K
KIDNEYIMAGING
The various kidney imaging techniques can provide different types ofinformation
to help doctors investigate and diagnose kidney disorders.
MRI and CT scanning
These techniques produce cross-
sectional images of bodytissues,
displayed as computer-generated
pictures. They clearly show
structural abnormalities such as
tumours and cysts. This MRI scan of
the abdomen shows a polycystic
kidney (on the right of the image).
C y s t o n l e f t k i d n e y
R i g h t k i d n e y
IVU (Intravenous urography)
This is a type ofX-ray in which
fluid containing a contrast
medium (a substance opaque to
X-rays) is introduced into the
urinary system, then X-rays are
taken. The images show how the
fluid moves through the kidneys,
ureters, and bladder, and can
show up any obstructions, such
as stones in the urinarytract.
R i g h t k i d n e y
L e f t k i d n e y
U r e t e r s
P e lv is
B l a d d e r
Ultrasound scanning
This is a quicktechnique, which
provides clear images ofthe
structure of the kidney. It can
reveal fluid-filled structures such
as cysts, which can be clearly
differentiated from the kidney
tissue surrounding them.
O u t lin e o f k i d n e y
C y st
Radionuclide scanning
This produces coloured images
to show the functioning ofthe
kidneys. (This scan is taken from
the back.) Areas that are brighter
than normal show overactive cells,
as in a tumour; colours that are
less intense than normal show
underactivity, as in kidneyfailure.
L e f t k i d n e y
R i g h t k i d n e y
T w o
t y p e s
o f
r a d i o n u c l i d e s c a n n i n g
a r e
u s e d : D M S A a n d D T P A s c a n n i n g . D M S A
i s
g i v e n
b y
i n t r a v e n o u s
i n j e c t i o n
a n d
b i n d s t o c e l l s i n t h e k i d n e y t u b u l e s , g i v -
i n g
a
s i n g l e ,
s t a t i c
p i c t u r e
o f
t h e
k i d n e y s . D T P A , a l s o g i v e n i n t r a v e n o u s l y ,
i s f i l t e r e d i n t h e k i d n e y s a n d p a s s e s o u t
i n t h e u r i n e . P i c t u r e s t a k e n a t i n t e r v a l s
r e c o r d i t s c l e a r a n c e b y t h e k i d n e y , p r o -
v i d i n g a n i n d i c a t o r o f k i d n e y f u n c t i o n .
k id n e y , p o ly c y s tic
A n
i n h e r i t e d
d i s o r d e r
i n
w h i c h
b o t h
k i d n e y s
d e v e l o p
n u m e r o u s
c y s t s
t h a t
g r a d u a l l y
e n l a r g e
u n t i l
m o s t
o f
t h e
n o r m a l
t i s s u e
i s
d e s t r o y e d .
P o l y c y s t i c
k i d n e y
d i s e a s e
i s
d i s t i n g u i s h e d
f r o m
m u l t i p l e
s i m p l e
k i d n e y
c y s t s
,
w h i c h
o c c u r c o m m o n l y w i t h i n c r e a s i n g a g e .
TYPES
T h e r e a r e t w o t y p e s o f p o l y c y s t i c d i s -
e a s e . T h e
m o s t
c o m
m
o n
t y p e
u s u a l l y
a p p e a r s i n m i d d l e a g e ,
p r o d u c i n g
a b -
d o m i n a l s w e l l i n g ,
p a i n ,
a n d
b l o o d i n
t h e
u r i n e .
A s
t h e
d i s e a s e
p r o g r e s s e s ,
h y p e r t e n s i o n
( h i g h b l o o d p r e s s u r e )
a n d
k i d n e y f a i l u r e
m a y r e s u l t .
T h e
s e c o n d
t y p e
o f p o l y c y s t i c
d i s -
e a s e , w h i c h i s r a r e , c a u s e s e n l a r g e m e n t
o f t h e
k i d n e y s
a n d
k i d n e y
f a i l u r e
i n
i n f a n t s a n d y o u n g c h i l d r e n .
TREATMENT AND PREVENTION
T h e r e i s n o e f f e c t i v e t r e a t m e n t f o r p r e -
s e r v i n g k i d n e y f u n c t i o n i n e i t h e r t y p e
o f t h e c o n d i t i o n , b u t s y m p t o m s o f k i d -
n e y
f a i l u r e
c a n
b e
t r e a t e d
b y
d i a l y s i s
( a r t i f i c i a l p u r i f i c a t i o n o f t h e b l o o d ) a n d
k i d n e y t r a n s p l a n t
.
P e o p l e w i t h a f a m i l y h i s t o r y o f t h i s d i s -
e a s e m a y n e e d
g e n e t i c c o u n s e l l i n g
b e f o r e
s t a r t i n g a f a m i l y . T h e a d u l t f o r m i s a n
a u t o s o m a l
d o m i n a n t
d i s o r d e r
a n d
a n
a f f e c t e d p a r e n t h a s a 5 0 p e r c e n t c h a n c e
o f p a s s i n g o n t h e d e f e c t i v e g e n e . I f b o t h
p a r e n t s c a r r y t h e g e n e f o r t h e j u v e n i l e
f o r m
(
a u t o s o m a l r e c e s s i v e d i s o r d e r
),
t h e i r
f e t u s c a n b e e x a m i n e d u s i n g
u l t r a s o u n d
s c a n n i n g
t o d e t e c t k i d n e y e n l a r g e m e n t .
k id n e y s to n e
S e e
c a l c u l u s , u r i n a r y t r a c t
.
k id n e y tra n s p la n t
A n o p e r a t i o n i n
w h i c h a p e r s o n
w i t h
c h r o n i c
k i d n e y f a i l u r e
r e c e i v e s a h e a l t h y
k i d n e y f r o m a l i v i n g o r , m o r e c o m
m
o n -
ly , a d e a d d o n o r . O n e d o n o r k i d n e y c a n
m a i n t a i n t h e h e a l t h o f t h e r e c i p i e n t .
T h e n e w k i d n e y i s p l a c e d i n t h e
p e l v i s
t h r o u g h
a n
i n c i s i o n
i n
t h e
a b d o m e n
a n d c a r e f u l l y p o s i t i o n e d s o t h a t i t c a n
b e
c o n n e c t e d
e a s i l y
t o
a
n e a r b y
v e i n
a n d a r t e r y a n d t o t h e
b l a d d e r
.
T h e d i s -
e a s e d k i d n e y s m a y b e l e f t i n p l a c e .
T h e t r a n s p l a n t r e m o v e s t h e n e e d f o r
d i a l y s i s
( a r t i f i c i a l p u r i f i c a t i o n o f b l o o d )
a n d o f t e n a l l o w s a r e t u r n t o a n o r m a l
l i f e s t y l e . T h e p r o c e d u r e i s m
o r e s t r a i g h t -
f o r w a r d
t h a n
t r a n s p l a n t a t i o n
o f o t h e r
o r g a n s . U n l e s s t h e d o n o r i s a n i d e n t i c a l
t w i n ,
i m m u n o s u p p r e s s a n t d r u g s
a r e g i v e n
t o a v o i d r e j e c t i o n o f t h e k i d n e y
k id n e y tu m o u rs
G r o w t h s i n t h e
k i d n e y
.
K i d n e y t u m o u r s
m a y b e c a n c e r o u s ( s e e
k i d n e y c a n c e r
)
o r
n o n c a n c e r o u s . T h e l a t t e r t y p e , w h i c h i n -
c l u d e
f i b r o m a s , l i p o m a s ,
a n d
l e i o m y o m a s
,
a r e o f t e n s y m p t o m l e s s , a l t h o u g h a
h a e -
m a n g i o m a
( c o m p o s e d o f a c o l l e c t i o n o f
b l o o d v e s s e l s ) m a y g r o w v e r y l a r g e a n d
c a u s e b l o o d t o a p p e a r i n t h e u r i n e .
CT scan of a kidney tumour
In this scan, the body is seen from below, with the
spine at the base of the image. The kidneys are the
round shapes on either side. A tumour (dark mass)
can be seen on the left kidney (right of image).
450
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