Journal of Rehabilitation Medicine 51-8 | Page 88

J Rehabil Med 2019; 51: 624–625
LETTER TO THE EDITOR
ULTRASOUND IMAGING FOR “DUMMIES”: GETTING ORIENTED AMONG THE PLANES
Ultrasound (US) imaging has consolidated its place
among the other routine evaluation/imaging methods
used by physiatrists in daily clinical practice (1, 2).
There is an ever-increasing need for its prompt technical
application and interpretation (3, 4). The aim of this let-
ter is to clarify a particular issue as regards the orienta-
tion between probe positioning and the corresponding
images on the US screen. Independent of the probe type
(linear, convex, hockey-stick) selected for imaging va-
rious structures/pathologies at different depths or with
different surface properties, getting well-oriented is not
as easy as might initially be thought. In addition, ques-
tions often arise, such as “which plane is the probe in?”
or “’which plane of the patient am I looking at?”, etc.
Worse would be the scenario whereby the sonographer
is unware of these issues or does not care, but instead
has a fixed image memory for different structures. This
might pose significant additional challenges, especially
if an intervention is planned (5, 6).
“Getting lost” in the US screen while the long
injector/needle is inside an anxious patient would
indisputably be terrifying. At this point, 3 noteworthy
hints for “dummies” would be: (i) the US screen always
corresponds to the coronal plane in the universe; (ii) US
imaging is a sort of “tomographic examination” that
permits the sonographer to “cut the body into slices”
with a possibility of infinite planes; and (iii) the deeper
you see on the screen refers to what resides “away”
from the footprint of your probe (in the patient’s body).
In order to clarify this discussion, we present here 2
common/exemplary imaging scenarios; shoulder (Fig.
1) and knee (Fig. 2). The knee imaging is easier to
interpret because the plane of the probe and the US
screen are parallel to each other; in this sense “spatial
planning” of the interventional procedure (e.g. where
can I enter with the needle?, where should the needle be
directed?) is simpler and more intuitive (Fig. 2). Thus,
static and dynamic imaging can readily be followed
Fig. 1. Anterior short-axis ultrasound imaging for the shoulder. While the patient is in a sitting position, the probe is naturally positioned in the
transverse plane (A), whereas the image on the screen is in the coronal plane (B). While the patient is in a lying position (C), the 2 aforementioned
planes are aligned parallel in universe. Del: deltoid muscle; GT: greater tuberosity; LT: lesser tuberosity; asterisk: long head of the biceps tendon.
Fig. 2. Anterior long-axis ultrasound imaging for the knee. As the patient is in sitting/lying position, the probe and the US screen are aligned in the
same plane. Pa: patella; F: femur; PFP: prefemoral fat pad; SFP: suprapatellar fat pad; asterisk: suprapatellar bursa/recess; white arrowheads:
quadriceps tendon.
This is an open access article under the CC BY-NC license. www.medicaljournals.se/jrm
doi: 10.2340/16501977-2581
Journal Compilation © 2019 Foundation of Rehabilitation Information. ISSN 1650-1977