Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5189_Библиотеки_им_академика_М_И_Перельмана.pdf
44
T. Minami
Refraction Artifacts
When a sound wave encounters another medium
with a different propagation speed at an oblique
angle, it can refract, or bend. We see this property
in light as well, when an image is distorted when
seen through water compared to air [5].
Pro-tip
Blood ow can be useful to identify arti-
facts. Artifacts should not affect blood ow.
Summary Points
• An ultrasound machine creates images based
on the physical properties of the ultrasound
wave, with assumptions of its expected
behavior.
• Artifacts arise when the actual behaviors
of the ultrasound deviate from these
assumptions.
• Understanding US artifacts is essential as we
can avoid making erroneous conclusions from
the artifacts. It is also important as we recog-
nize specic pathophysiology from specic
image artifacts.
• There are three types of US artifacts.
– Reection: reverberation, ring-down,
comet tail, mirror image
– Attenuation: shadow artifact, enhancement
artifact
– Beam properties: side-lobe artifact
Question
1. A 51-year-old obese male is admitted with
septic shock. A right internal jugular hemodialysis catheter is placed, and dialysis is underway. You perform a transesophageal
echocardiogram. You see the following on
mid-esophageal long-axis (Video 3.1). What
is the appropriate next step in management?
A. Remove the catheter, it is arterially placed
B. Image the SVC and aorta in the short axis
C. CT scan of the chest with contrast to con-
rm aortic dissection
D. Plan for pericardiocentesis
Answer: B.Image the SVC and aorta in the
short axis (Video 3.2).
The image seen prior is an artifact of the
catheter in the SVC creating a side-lobe artifact into the ascending aorta. Side lobe artifacts can occur both in the imaging plane and
outside the image plane. In the question, the
SVC is not visualized and out of the imaging
plane. When there is suspicion for artifacts,
image for multiple planes. Color Flow imaging may also help determine if a nding is
real, as both aortic dissection and an intraaortic catheter will likely affect blood ow.
The other advice is that it is usually good to be
thorough and complete an exam rather than
rush to treatment based one image. Because
this is an artifact, there is no dissection or
intra-aortic catheter. There is no evidence for
tamponade physiology.
References
1. Feldman MK, Katyal S, Blackwood MS.US artifacts.
Radiographics. 2009;29:1179–89.
2. Edelman S.Understanding ultrasound physics. 3rd ed.
Texas: ESP; 2004.
3. Lichtenstein DA, Meziere GA. Relevance of lung
ultrasound in the diagnosis of acute respiratory failure:
the BLUE protocol. Chest. 2008;134:117–25.
4. Walz-Flannigan AI, Brossoit KJ, Magnuson DJ,
Schueler BA.Pictorial review of digital radiography
artifacts. Radiographics. 2018;38:833–46.
5. Kremkau F.Sonography instruments and principles.
10th ed. Philadelphia: Elsevier; 2021.
Positioning, Safety, Manipulation
ofProbe
SameerKhanijo andMangalaNarasimhan
4
Learning Objectives
1. Suitable patient positioning is essential when
performing all ultrasound scans
2. Optimal patient positioning for cardiac ultrasound involves the patient supine, and if possible, in the left lateral decubitus position
3. The probe should be grasped with the rst
three ngers of the dominant hand
4. The ultrasonographer should be seated on the
same side of the patient as the ultrasound
machine, so they can operate the machine
while scanning
5. Five basic probe movements: sliding, rocking,
tilting, rotating, and compression
Point-of-care ultrasound involves medical provider acquisition and interpretation of ultrasound
images at the patient’s bedside to diagnose and
guide medical therapies [1]. The time-consuming
step in this focused use of ultrasound is often the
image acquisition as it involves appropriate positioning of the patient and sonographer and
manipulation, and ne-tuning, of the transducer
in multiple directions, to obtain the ideal image
[2]. In this chapter we will review patient positioning and safety, ergonomics, practitioner posi-
S. Khanijo · M. Narasimhan (*)
Donald and Barbara Zucker School of Medicine
at Hofstra/Northwell, New York, NY, USA
e-mail: skhanijo2@northwell.edu;
mnarasimhan@northwell.edu
tioning, and holding and manipulation of the
ultrasound probe.
Patient and sonographer positioning and ergonomics are important in the quest for obtaining
optimal imaging. Poor positioning affects scan
time and can cause chronic injuries in ultrasound
practitioners [3]. Optimal patient positioning for
cardiac ultrasound involves the patient supine, or
in the left lateral decubitus position, with arms
raised above their head as this brings the heart
closest to the chest wall [4]. In critical care echocardiography, patient positioning may be
restricted due to the clinical condition (intubation, pacing, or central access sites), room space
with lots of equipment present, and the inability
to move patients. Mechanical ventilation may
alter hemodynamics and therefore scan position
in the critically ill [5].
Ultrasonographers should be positioned to the
side of the patient and in a comfortable position,
seated when feasible. The ultrasound machine
should be on the same side as the scanner.
Transthoracic evaluation can be performed with
the sonographer sitting on either the patient’s left
or right side and this is often a matter of personal
preference, custom, and comfort. However, when
scanning with the right hand the sonographer is
often seated on the right side of the patient and
the machine is manipulated with the left hand. If
scanning on the left side of the patient, the left
hand is used to scan, and the machine is adjusted
with the right hand (Image 4.1). Your arms should
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2025
M. J. Lanspa, A. T. Levinson (eds.), Echocardiography and Ultrasonography in the ICU,
Respiratory Medicine, https://doi.org/10.1007/978-3-031-80038-2_4
45
46
S. Khanijo and M. Narasimhan
Image 4.1 The machine should be placed on the same
side as the operator so they can adjust the machine
be as close to your side as possible and not crossing over your body with the patient positioned
close to you. Make sure you are positioned appropriately to reach onto, and when necessary, over
the patient. Standing may help provide better
posture. Sonographers should move down the
bed rather than contorting their bodies to reach
behind them. It is best to keep all joints in a neutral position when able. Developing the ability to
scan from both sides minimizes the risk of repetitive use injuries and prepares the sonographer for
circumstances where only one side of the patient
is available for scanning. One important note is
that patient positioning may inuence the ndings on lung ultrasonography, particularly in the
heart failure population, and so a consistent
approach to patient positioning during point-ofcare ultrasonography may be important to monitor dynamic changes [6].
Once the patient and provider are appropriately positioned ultrasonography can begin.
Generally, the probe should be held like a pen,
although it can be held in the overhand position
when imaging the heart in subcostal.
Ultrasonographers should not be afraid of getting
gel on their hands or making physical contact
with the patient. The probe, also known as the
transducer, should be grasped with the rst three
ngers of the dominant hand. This is enough to
Image 4.2 Best hand position for the probe
hold and maneuver the probe and leaves the pinkie, nger, and heel of the palm, to stabilize the
probe on the patient (Image 4.2). Direct contact
with the patient is particularly important for
obtaining quality images. Direct contact allows
one to properly stabilize the transducer on the
patient without having to use excessive pressure,
thus making the patient more comfortable and
decreasing fatigue on the hand. Appropriate probe
holding technique will allow one to obtain optimal images without sliding around too much and
without applying too much pressure: this becomes
even more important when the probe is being used
for procedural guidance. Remember to clean the
probe immediately after scanning and prior to use
on a new patient and to use a sterile probe cover if
performing a sterile procedure (Image 4.3).
Ultrasound probe manipulation is important
in point-of-care ultrasound as patient anatomy
and clinical conditions vary greatly. Often, the
transducer placement illustrated in textbooks
does not work in real time. While experienced
clinicians will naturally adjust the probe, new
sonographers will often move the transducer in
multiple planes simultaneously resulting in
repeated suboptimal image acquisition and frustration [2]. Slow ne movements should be
made, and evaluation of the changes seen on the
screen should be continuous.
4 Positioning, Safety, Manipulation ofProbe
Image 4.3 Three probe
types: (a) linear probe
(b) abdominal probe (c)
Smaller linear probe
Initially, there was no consistent terminology
for the manipulation of the ultrasound probe to
obtain high-quality images. In 1999, the American
Institute of Ultrasound in Medicine published a
technical bulletin, which described ve basic
movements: sliding, rocking, tilting, rotating, and
compression [7]. While this nomenclature is standardized, there remain substantial inconsistencies
in terminology describing transducer motion.
Some frequently used, nonstandard terms, include
move, angle, fan, rock, and heel-toe [2].
Understanding, and mastering, the transducer
manipulation techniques will allow practitioners
to obtain the desired images. These movements
are [8] (Image 4.4):
47
Rotate
Tilt/Fan
Slide
Rock
• Sliding involves moving the transducer along
the long axis of the probe across the body with
a consistent angle against the body. Sliding will
move the target structure from side to side on
the screen. This moves the entire probe in a spe-
cic direction to nd a better imaging window.
• Rocking involves motion in the long axis of
the probe at a xed point on the body while
changing the angle against the body. This
allows you to help center the area of interest
and keeps the desired image in plane through-
out the manipulation.
• Tilting, also called fanning, involves a side-
to- side motion along the short axis of the
probe. This allows multiple cross-sectional
Image 4.4 Probe movements
images of a structure of interest. The axis is
unchanged while tilting.
• Rotation is most used to move between short-
axis and long-axis views of a desired structure.
• Compression involves direct pressure on
the transducer onto the body causing compression of the area of interest by the
transducer.
48
S. Khanijo and M. Narasimhan
With all of these tools, scanning can be done
consistently, safely, and comfortably. Teaching
can also be done consistently and using standard
terminology.
Summary Points
• Patient and ultrasonographer positions can
greatly affect the quality of the images obtained.
• In critical care scanning, optimal positioning
may not be possible.
• Ideally, the ultrasonographer should be seated
on the same side as the ultrasound machine in
order to be able to operate the machine while
scanning.
• The probe should be held like a pen with con-
tact made with the patient’s body with the
hypothenar eminence.
• Slow movements should be made while alter-
ing an image or changing an angle.
• Use standardized nomenclature. There are ve
basic movements described: sliding, rocking,
tilting, rotating, and compression.
Pro-tips
The probe should be grasped with the rst
three ngers of the dominant hand. This
leaves the pinkie, nger, and heel of the palm
free to stabilize the probe on the patient.
In 1999, the American Institute of Ultrasound
in Medicine described ve basic probe movements: sliding, rocking, tilting, rotating, and
compression.
Questions
1. Optimal position for the scanner is:
A. On the same side as the machine
B. On the opposite side of the machine
C. Either side is ne
Answer: (A) On the same side as the
machine
For point-of-care ultrasonography, the
scanner must be on the same side as the
machine as the operator must work with
machines as they are scanning. There is usually only one scanner and no technician or
other person to operate the machine.
Adjustments must be made to optimize the
image to x gain, depth, and to make
measurements.
2. To go from the parasternal long axis view of
the heart to the short axis view of the heart the
motion employed is:
A. Tilting
B. Rocking
C. Rotating
D. Sliding
Answer: (C) Rotating
Rotating is moving the probe around the
transducer axis, on a xed point on the body, in
a clockwise or counterclockwise direction. This
motion is the most common one used when
going from a long-axis view of a structure to a
short-axis view of the same structure. When
moving from the parasternal long-axis view to
short-axis view the rotation is clockwise with
the pointer starting at the right shoulder and
ending at the left shoulder (approximately).
References
1. Moore CL, Copel JA.Point-of-care ultrasonography.
N Engl J Med. 2011;364:749–57.
2. Bahner DP, Blickendorf JM, Bacbrader M, et al.
Language of transducer manipulation: codifying terms for effective teaching. J Ultrasound Med.
2016;34:183–8.
3. Claes F, Berger J, Stassijns G.Arm and neck pain in
ultrasonographers. Hum Factors. 2015;57:238–45.
4. Bauman DJ.Position of patient for echocardiography.
Chest. 1977;72(1):132.
5. Kirkpatrick JN, Grimm R, Johri AM, Kimura BJ,
Kort S, Labovitz AJ, Lanspa M, Phillip S, Raza S,
Thorson K, Turner J.Recommendations for echocardiography laboratories participating in cardiac point
of care cardiac ultrasound (POCUS) and critical care
echocardiography training: report from the American
Society of Echocardiography. J Am Soc Echocardiogr.
2020;33(4):409–22.e4.
6. Frasure SE, Matilsky DK, Siadecki SD, Platz E, Saul
T, Lewis RE. Impact of patient positioning on lung
ultrasound ndings in acute heart failure. Eur Heart J
Acute Cardiovasc Care. 2015;4:326–32.
7. American Institute of Ultrasound in Medicine.
AIUM technical bulletin: transducer manipulation. J
Ultrasound Med. 1999;18:169–75.
8. Ramsingh D, Gatling J.Teaching point-of-care ultrasound (POCUS) to the perioperative physician. In:
Bowe E, Schell R, DiLorenzo A, editors. Education
in anesthesia: how to deliver the best learning experience. Cambridge: Cambridge University Press; 2018.
p.131–50.
Part II
Echocardiography
Transthoracic Windows andViews
NovaPanebianco andMichaelO’Neil
5
Learning Objective
1. Describe the surface anatomy, sonographic
anatomy, imaging tips, and common pearls
and pitfalls for each of the transthoracic echocardiography views.
Parasternal Window: PLAX, PSAX,
RV Inow, RV Outow Views
The parasternal window is useful in the assessment of left ventricular ejection fraction, the
presence of pericardial effusion and tamponade
physiology, the right ventricle to left ventricle
ratio, pulmonary inow and outow anatomy, as
well as valvular anatomy and function.
Parasternal Long Axis (PLAX)
See Fig.5.1.
Supplementary Information The online version contains supplementary material available at https://doi.
org/10.1007/978- 3- 031- 80038- 2_5.
N. Panebianco (*)
Department of Emergency Medicine, University
of Pennsylvania, Philadelphia, PA, USA
e-mail: nova.panebianco@uphs.upenn.edu
M. O’Neil
Main Line Emergency Medicine Associates,
West Chester, PA, USA
e-mail: Michael.O’neil@pennmedicine.upenn.edu
External Surface Anatomy
For the parasternal long-axis view, the patient
should be placed in the supine or left lateral decubitus position. Place the probe on the patient’s
left chest just lateral to the sternum in the third to
fth intercostal space with the probe marker facing the right shoulder.
Sonographic Anatomy
In this image, the right ventricle, interventricular septum, left ventricle, aortic outow tract,
aortic root, and the left atrium should be visualized. Deep into the cardiac structures and pericardium, the descending thoracic aorta may be
visualized in the transverse plane (Fig. 5.1,
Video 5.1).
Imaging Tips
If no clear cardiac image is seen in this window,
slide the probe cephalad or caudal until the heart
is encountered. The probe may need to be rotated
clockwise or counter-clockwise to match the axis
of the patient’s heart.
An image is in the plane when the mitral and
aortic valves are seen clearly. To visualize more
of the base of the heart, slide or rock the probe
toward the sternum. To see more of the LV, slide
or rock the probe toward the apex.
The gain should be set so that the uid in the
heart is black, but not so low that the endocardium is difcult to see. Place the focal zone in the
center of the heart.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2025
M. J. Lanspa, A. T. Levinson (eds.), Echocardiography and Ultrasonography in the ICU,
Respiratory Medicine, https://doi.org/10.1007/978-3-031-80038-2_5
51
52
Fig. 5.1 Parasternal
long axis (PLAX)
N. Panebianco and M. O’Neil
Pearls and Pitfalls
• Oblique views can overestimate the EF.
• Patients with COPD/asthma may have midline
hearts with images obstructed by the sternum.
To improve imaging, have the patient roll into
the left-lateral position (if possible), which
may drop the heart into view.
• Pregnant patients may need signicantly more
rotation to match their heart’s axis.
• Pleural effusion can be mistaken for pericardial effusion. To distinguish the two conditions, it is important to identify the
descending thoracic aorta. In a circumferential pericardial effusion, pericardial uid
will tract anterior to the descending thoracic
aorta and may cross the midline. The uid in
a pleural effusion will track posterior to the
descending thoracic aorta and not cross the
midline.
• In a patient where the lung is obscuring relevant cardiac anatomy having the patient fully
exhale may provide a brief opportunity to
obtain diagnostic images.
• The strategies described above to locate the
heart are starting points; however, what you
see on the screen will dictate how to move
your hand when optimizing images.
Right Ventricular (RV) Inow
See Fig.5.2.
External Surface Anatomy
From the parasternal long-axis view, the probe is
tilted caudally and toward the right hip to assess
the right ventricle and give an image of the inow
of the right ventricle (Fig.5.2, Video 5.2).
Sonographic Anatomy
The right ventricle, anterior and posterior leaets
of the tricuspid valve, right atrium, SVC, and
IVC are seen in this sonographic view. The left
ventricle should not be visible if appropriately in
the plane.
Imaging Tips
To optimize the image, roll the patient into the
left-lateral decubitus position and have them
fully exhale.
Pearls and Pitfalls
• Abdominal distention, bowel gas, and stomach contents can interfere with quality images.
• Patients with COPD and asthma may have limited right ventricular views in this window.
5 Transthoracic Windows andViews
Fig. 5.2 Right
ventricular (RV) inow
view
Fig. 5.3 Right
ventricular (RV) outow
view
53
RV Outow
See Fig.5.3.
External Anatomy
In this view, the probe should then be tilted from
the PSLA window toward the left shoulder to
visualize the right atrium and pulmonary artery.
Sonographic Anatomy
In this view, the right atrium, pulmonary valve,
and pulmonary artery should be visualized
(Fig.5.3, Video 5.3).
Imaging Tip
To ensure the image is in the plane, slight rotation
or tilt of the probe may be necessary.
54
N. Panebianco and M. O’Neil
Pearls and Pitfalls
• In an awake and cooperative patient, having
them take a deep breath and then completely
exhale may remove artifacts caused by a lung
curtain.
• Left lateral decubitus positioning is also helpful for this view.
Parasternal Short Axis (PSAX)
The PSAX view, depending on the plane being
visualized, is useful in assessing LV ejection
fraction, regional wall motion abnormalities, aortic valvular structure, mitral valvular structure,
RV/LV ratio, and septal movement abnormalities
caused by increased pulmonary pressures or
volumes.
External Anatomy
For the PSAX view, the ultrasound probe is
placed in the third to fth intercostal space with
the patient in the supine or left lateral decubitus
position. The probe marker in this instance should
be directed toward the patient’s left shoulder.
From the PSLA axis view, the PSSA view is
obtained by rotating the probe 90° clockwise.
Sonographic Anatomy
At the mid-ventricular (or papillary muscle)
level, the papillary muscles are clearly visualized
in the O-shaped left ventricle. This axis is
particularly useful for assessing LV ejection fraction, regional wall motion abnormalities,
increased RV volume/pressure, and pericardial
effusion (Fig.5.4, Video 5.4).
From the mid-ventricular view, the mitral
valve short-axis view is obtained by fanning or
tilting the beam of the probe toward the right
shoulder. In this view, the right ventricle and left
ventricle are visualized. The thin anterior and
posterior leaets of the mitral valve are visualized within the short-axis view of the left ventricle. The axis is particularly useful for assessing
the anatomy of the mitral valve.
To obtain the basilar short view, the probe is
tilted further toward the right shoulder. In this
plane, the base of the heart, right ventricular inow
and outow, aortic valve, and left atrium are visualized. The three aortic valvular leaets should be
clearly visible giving the “Mercedes-Benz” sign.
This plane is commonly used to assess for valvular
anatomy/abnormalities and to assess the gradients
across the tricuspid valve and pulmonary valves
(Fig.5.5, Video 5.5).
Fig. 5.4 Parasternal
short-axis (PSAX) at the
level of the papillary
muscles