Read before making
Sonoexams:
Blue
text in these
guidelines define the actual Sonoexam scanning
protocols.
Red links in the guidelines lead to live
video samples of the protocols. The videos are large, having diagnostic
quality, and in some cases there are low resolution
alternatives.
Sonoexam protocols:
This Sonoexam aims at covering all lymph node locations.
The neck is basically divided into eight slightly overlapping sectors around
the cirkumference, beginning with the left dorsal part and ending with the
right dorsal part. The number of sectors may be modified to fit necks and
transducers of various sizes, since overlapping of the sector borders is
important. A linear array transducer (15L8w) is preferred, but large, heavily
attenuating necks may require the higher penetration of a curved
array. The patient has the head placed as low as tolerable.
- Transverse scan of the entire length of the neck
dorsally by the left side of the midline, from skull base to shoulder.
Depth to the surface of the vertebral column with a small margin.
- 1 is repeated, but with the transducer positioned
laterally on the dorsal half of the neck, slightly overlapping to the
ventral half of the neck.
- Transverse scan of the left lateral aspect of the
ventral half of the neck with slight overlapping of 2. The transducer is
aimed so that the ventral parts of the deep tissues are preferred over
those by the transverse processes of the vertebrae.
- Transverse scan ventrally along the left side of the
neck, slightly overlapping the midline. The field of view should aim as
dorsally as possible, thus avoiding much of the non-information of the air
in trachea. It is essential that the areas around the large vessels are
well overlapped by scans 3 and 4.
- As 4 to 1, but on the right side in reversed order,
from the ventral midline to the right dorsal part of the neck.
- Oblique scan aiming at the mouth
floor, perpendicular to the lower edge of the mandible, from the left
mandibular angle to the chin.
- Same as 5, but from the chin to the right mandibular angle.
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A linear array transducer is preferred, but large, heavily attenuating necks
may require the addition of the deeper penetration of a curved array. The
patient has the head placed as low as tolerable. The Sonoexam aims at seeing
the two thyroid lobes from two angles transversally, one longitudinally plus
isthmus. Most frequently the isthmus is located between the upper parts of the
lobes, giving the thyroid the shape of a “U” turned upside down. However,
isthmus can be located at any level, giving the thyroid the shape of an “H” or
a “U”.
- Transverse Sonoscan of the left lobe from a slightly
lateral position, the scan plane pointing about 45 degrees medially.
- Transverse Sonoscan of the left lobe from a ventral
position, pointing almost in the dorsal direction, with the trachea just
visible at the medial edge.
- Transverse Sonoscan of the isthmus in the midline.
- 2 and 1 are repeated covering the right lobe,
respectively.
- Longitudinal Sonoscan covering the upper part of the
left lobe, isthmus, and the upper part of the right lobe, in a circular
motion.
- Longitudinal Sonoscan covering the lower part of the
left lobe, over trachea and covering the lower part of the right lobe, in
a circular motion.
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The position and size of the normal gallbladder vary between individuals.
Especially the neck of the gallbladder may be difficult to visualize. Sonoscans
of the lateral segments of the left liver lobe and the head of the pancreas are
done for evaluation of the bile ducts.
- Supine position, intercostal exam with the transducer
aligned along the ribs, one Sonoscan.
- Supine position, inspiration, transversal Sonoscan of
the gallbladder subcostally.
- Supine position, inspiration, longitudinal Sonoscan of
the gallbladder subcostally.
- Left decubitus position, inspiration, transversal
Sonoscan of the gallbladder subcostally.
- Left decubitus position, inspiration, longitudinal
Sonoscan of the gallbladder subcostally.
- Left decubitus position, inspiration, the transducer
plane along the upper part of the main bile duct and the portal vein, one
Sonoscan covering the liver hilum.
- Supine position, inspiration, transversal Sonoscan of
liver segments 2, 3 and left part of 4.
- Supine position, inspiration, longitudinal Sonoscan of
liver segments 2, 3 and left part of 4. Priority of the diaphragm over the
caudal border of the liver.
- Supine position, inspiration, transversal Sonoscan of
the pancreatic head. From above the pancreas and downward passed the
horizontal part of duodenum.
- Supine position, inspiration, longitudinal Sonoscan of
the pancreatic head. From the superior mesenteric vein to the descending
part of duodenum.
Gallstone protocol Video showing how each Sonoscan
should be presented on the monitor. Small stone in neck of gallbladder and
slightly hypertrophic gall bladder wall..
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The liver consists of 8 segments. The goal of the Sonoexam is coverage of
the entire liver and definition of the segment where any pathology is located.
All scanning of transversal scan planes is done craniocaudally, and longitudinal
scans are scanned from left to right. Together, the transversal scans should
cover the entire liver in the cranial-caudal direction with some margin.
In all longitudinal scans except 3 there is priority of diaphragm.
In scan 3 the lower liver edge is the priority.
- Supine position, inspiration, transversal Sonoscan of
segments 2 and 3.
- Supine position, inspiration, longitudinal Sonoscan of
segments 2 and 3.
- Left decubitus position, inspiration, longitudinal
Sonoscan of the caudal part of the entire liver. The depth should reach a
few centimeters deeper than to the first branching of the portal vein.
- Left decubitus position, inspiration, transversal
Sonoscan with the inferior v cava positioned in the deep centre of the
field of view. This Sonoscan includes segments 4, 1 and medial parts of
segments 7 and 8.
- Left decubitus position, inspiration, longitudinal
Sonoscan including segments 4, 1, medial parts of 7 and 8, passing the
inferior v cava halfway through the Sonoscan.
- Left decubitus position, inspiration, transversal
Sonoscan below the right costal arch. This Sonoscan includes the lateral
parts of segments 7 and 8 and the entire segments 5-6.
- Left decubitus position, inspiration, longitudinal
Sonoscan below the right costal arch aiming at the lateral parts of
segments 8, 7, 6 and 5 respectively. Priority of the diaphragm over caudal
parts.
If it is evident that Sonoscans 1-7 have covered the entire
liver including the right lateral aspect, we omit Sonoscans 8 and 9.
- Supine position. The right liver lobe is scanned with
the transducer plane along the intercostal spaces, one 10 second Sonoscan
jumping interstitium by interstitium craniocaudally. Depth setting just
passed the portal vein.
- Supine position, transversal scan with the transducer
positioned subcostally in the right lateral flank for access to the caudal
margin of the right liver lobe. The depth is set to cover the medial
surface of the accessible liver, but not deeper.
- Left decubitus position, inspiration, transversal and
longitudinal Sonoscans of the gallbladder subcostally.
- Left decubitus position, inspiration, the transducer
plane along the upper part of the main bile duct and the portal vein, one
Sonoscan covering the liver hilum.
Liver
Video showing how each Sonoscan should be presented on the monitor. There is no
significant pathology in this exam.
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The
anatomy of the pancreas is complex, especially the correlation to its
surroundings. The head is the biggest part of the pancreas, and is positioned
slightly to the right of the midline in the supine position. The body and the
tail point to the left and slightly cranially to the splenic hilum from the
head. The common bile duct runs from the liver hilum down through the right
part of the head, and v mesenterica superior enters from the caudal aspect to
the left of the head behind the body, where it merges with v lienalis to form v
porta, which in turn runs slanted from the pancreas up to the liver hilum. The
pancreas Sonoexam aim at coverage of the entire organ including the common bile
duct and as much of the pancreatic duct as possible, of the upper part of v
mesenterica superior and the extrahepatic part of v porta. Pancreas is
sometimes partially or totally inaccessible, due to gas in the ventricle and
colon transversum. The tail is the part most often inaccessible. Accessibility
can sometimes be achieved by altering deapth of breath or by the sitting or
both decubital positions. The pancreas is very mobile sideways, especially in
thin patients, which makes the decubital positions even more efficient. Intake
of water may also create a window to the pancreas. The patient should always
have an empty stomach for the exam. For planned exams, an oral laxative taken
the previous day can make a great difference.
Steps 1, 2 and 4 are minimum requirements in abdominal surveys.
All steps are required in targeted pancreas examinations.
- Supine, inspiration, transverse scan in the
epigastrium, of the head and body through the horizontal part of the
duodenum.
- Supine, inspiration, longitudinal scan, from the tail
through the body and head, and the horizontal and descending parts of the
duodenum.
- Supine, inspiration, transverse scan below the left
costal arch, body and tail.
- Supine, breath according to access, along suitable
intercostal in the left flank, from upper ventral aspect of the kidney
well past splenic hilum, through tail.
- Left decubitus, inspiration, transversally along lower
part of common bile duct, slowly from v mes sup through common bile duct,
papilla Vateri into descending part of duodenum.
- Left decubitus, inspiration, longitudinally through the
head with concentration on common bile duct, pancreatic duct and papilla
Vateri, through duodenum.
Pancreas Video showing how each Sonoscan should be
presented on the monitor. There is no significant pathology in this exam.
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The
supine position is usually the best, but sometimes the right decubitus position
has advantages. The patient can usually breathe at liberty, but in some cases
inhalation improves access. Transducer 4C1 (curved abdominal). The objective is
coverage of the full volume of the splenic parenchyma. This is achieved by
tilting the longitudinal Sonoscans along the intercostal spaces, thus avoiding
lines of rib shadows across the scans, and by overlapping several consecutive
scans space by space intercostally The most difficult part to cover is the
cranial surface of the spleen due to gas interference from the pulmonary sinus.
Eventual transversal scans are performed with the 4V1 (vector) transducer at
a perpendicular angle to the longitudinal scans.
- Position the transducer along the most dorsal
intercostal space where the spleen can be seen, and scan at an ordinary
slow pace in a ventral-cranial direction as far as the ribs allow access
to the spleen.
- Move the transducer to the next ventral intercostal
space, and repeat the scanning technique in 1 with as large an overlap as
possible with the previous Sonoloop.
- Repeat 2 until the entire spleen has been covered.
- Change to transducer 4V1 and position it at an angle
perpendicular to the longitudinal Sonoloops. Repeat 1-3, but scan in a
ventral-caudal direction covering the entire spleen through each intercostal
space.
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The best
positions of the transducer are highly variable between individuals. It is
important to scan both kidneys both longitudinally and transversally in both
the supine and decubitus positions since pathology may show in one position but
not the other. Obstruction of visibility by the colon must be avoided. The
following guidelines represent the minimum requirements for acceptable
Sonoexams of the kidneys. Regarding the kidneys the basic scanning rule
"transverse first" is deliberately violated due to the fact that the
kidneys are initially most naturally approached longitudinally. When already in
this position the longitudinal scan becomes the first scan in order to save time.
In Sonoexams of the kidneys of small children it is often beneficial to
exchange the supine position for prone position, scanning the kidneys from the
back. It is important to remember the scanning directions and body marker
positions described in Sonodynamics
fundamentals.
For measurement of renal size, the longitudinal measurement is made bedside and
kept as a still image.
- Supine position, intercostal scan plane longitudinally
along the left kidney, one Sonoscan.
- Supine position, scan plane transversal or almost
transversal to the left kidney, one Sonoscan.
- Right decubitus position, most often inspiration, scan
plane longitudinally along the left kidney, one Sonoscan,
- Right decubitus position, most often inspiration, scan
plane transversal or almost transversal to the left kidney, one Sonoscan.
- Repeat 1-4 on the right kidney.
- Transversal Sonoscan of urinary bladder.
- Longitudinal Sonoscan of urinary bladder.
Kidneys/bladder Video showing how each scan should
be presented on the monitor. There is no significant pathology in this exam.
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Access is often easy below the level of the pancreas, while the upper 1/3 is
sometimes hidden. Accessibility problems can often be solved by inspiration,
the left decubitus position or compression. As a last resort the upper
abdominal aorta may be accessed through the liver (beware not to confuse the
inferior vena cava for the aorta) or the left flank. Obstructing intestine may
sometimes be pressed upward or downward, and angling the transducer can
sometimes give access behind a gassy intestine. The initial position to try is
the supine position.
For measurements it is important to keep the scan plane perpendicular to the
aorta on transverse scans or the measurements will be exaggerated.
- One
transversal Sonoscan of the upper abdominal aorta starting as cranially as
possible and ending well below the superior mesenteric artery.
- One
transversal Sonoscan of the lower abdominal aorta from the superior
mesenteric artery passed the aortic bifurcation.
- Three
longitudinal Sonoscans; one including the diaphragm, one centred on the
middle of the abdominal aorta and one including the aortic bifurcation.
- One
transversal and one longitudinal Sonoscan of each common iliac artery.
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One
practical way of fixation asking the patient to hold the penis cranially. It is
also favourable to ask the patient to tighten the skin of the scrotum by
placing his fingers on the ventras part of the scrotal skin and pulling
cranially. The machine is set at “Detail 1” using the 15L8w (linear)
transducer.
- One transversal Sonoscan craniocaudally of the left
testicle from a lateroventral approach.
- One transversal Sonoscan craniocaudally of the left
testicle from a medioventral approach.
- One longitudinal Sonoscan of the left testicle from
left to right. If the entire testicle does not fit into the field of view,
the Sonoscan is divided into one cranial and one caudal longitudinal
Sonoloop.
- 1-3 are repeated on the right testicle.
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A linear array transducer is preferred, but large, heavily attenuating knees
may require the higher penetration of a curved array. The patient lies in the
prone position, or may eventually stand up. The Sonoexam aims at capturing the
posterior medial, the intermediary and the posterior lateral aspects of the
rear of the knee, with about ten cm margin up and down from the joint level.
The Sonoscans are made according to the basic rule of up-down and toward the
examiner. This means that one begins with the lateral aspect of the right knee,
but with the medial aspect of the left knee, and the sides of the knees are
referred to as left and right in the protocol. The body marker is positioned
with the sides “as seen” from behind the patient.
- Transverse scan of the left aspect of the knee,
including the left surface of the muscles and the adjacent subcutaneous
fat.
- Transverse scan of the knees midline, with a depth that
just reaches the femur and tibia.
- 1 is repeated, but from the right aspect.
- Longitudinal scan of the rear circumference of the knee
from left to right (toward the examiner), slightly above the joint level.
- 4 is repeated at the joint level.
- 4 is repeated slightly below the joint level.
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The patient bends the knees. Transducer 15L8w (linear), “Detail 1” setting.
The depth setting to about 2 cm behind the tendon.
- One transversal Sonoscan directed to the left part of
the tendon, from the patella to the tibia.
- As 1, but with the tendon in the middle of the field of
view.
- As 1, but directed to the right part of the tendon.
- One longitudinal Sonoscan from left to right with the
tenopatellar junction in the upper margin of the field of view.
- One longitudinal Sonoscan from left to right of the
middle of the tendon.
- One longitudinal Sonoscan from left to right with the
tenofibular junction in the lower margin of the field of view.
- As 2, but of the opposite side tendon for comparison of
thickness.
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The patient in the prone position with the feet hanging out over the
“caudal” short end of the bed, bending the foot cranially for tension of the
tendon. Depth to about 2 cm passed the tendon.
- One transversal Sonoscan from about 15 cm above “floor
level” (the plantar surface of the heel)
- One longitudinal Sonoscan pointing at the tendon from a
left posterior oblique angle, including the tenocalcaneus junction.
- One longitudinal Sonoscan pointing at the tendon from a
strictly dorsal aspect, including the tenocalcaneus junction.
- One longitudinal Sonoscan pointing at the tendon from a
right posterior oblique angle, including the tenocalcaneus junction.
- As 2-4, but at a more cranial position slightly
overlapping Sonoscans 2-4.
- As 3, very slow scan, with colour Doppler at the “Low
flow” setting.
- 1 and 3 on the opposing side tendon, 3 being repeated
at a more cranial position slightly overlapping the previous Sonoscan.
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Ascites,
free blood (FAST):
The supine position. Depth reaching behind and above the liver and spleen
respectively, as well as behind the rectum in the Fossa Douglasii.
- One transversal Sonoscan covering the heart chamber
level from the epigastrium. This scan is included for completion of the
FAST protocol.
- Intercostal Sonoscan (one or two Sonoloops through the
liver for access above and behind it).
- Intercostal Sonoscan in the left flank, visualizing the
subdiaphragmal space above and behind the spleen.
- Transversal Sonoscan from a laterocaudal approach of
the paracolic gutter of the right flank, from subcostally to the pelvic
crista, with a depth setting to about 7 cm passed the abdominal wall.
- As 4, but on the left side.
- Transversally through the urinary bladder with about 7
cm margin behind it for visualization of the Fossa Douglasii.
- As 6, but longitudinally.
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