Type:
Educational Exhibit
Keywords:
Foreign bodies, Diagnostic procedure, Conventional radiography, Thorax, Mediastinum, Lung
Authors:
J. Arias Fernandez, L. García Del Barrio, M. Ferreira Caramalho, P. Slon, J. Etxano Cantera; Pamplona/ES
DOI:
10.1594/ecr2011/C-2290
Background
The portable chest X-ray (PCXR) is one of the most commonly requested radiographic examinations in the critically ill patient.
It’s readily available,
easy and quick to perform at the patient’s bedside,
and much less expensive than any other imaging modality.
The PCXR plays a key role in aiding diagnosis,
in monitoring evolution and in evaluating response to therapy.
The quality of the PCXR can be highly variable,
ranging from good to uninterpretable.
There are two groups of limitations to obtaining quality PCXR: The first group refers to the inability of critically ill patients to cooperate: without appropriate inspiration,
in decubitus and anteroposterior projection.
Patients are difficult to move and position adequately and so the chest may be imaged incompletely and in rotation artifact.
The second group refers to the X-ray quality due to portable system,
with difficulties in controlling scattered radiation and wide differences in film exposure.
Digital systems,
with exposure compensation and image processing,
have improved the PCXR quality.
And the introduction of picture archiving and communication systems (PACS) have increased fastness and disponibility of these images [1].
Nevertheless,
PCXR still poses unique challenge to the technologist.
The radiograph should be obtained at peak inspiration using 70 to 80 KVp and short exposure times to minimize respiratory artefact.
Focus to patient may be as high as possible to avoid magnification.
External objects should be removed from the field as much as possible to avoid mistakes.
Important problems in these patients may be clinically silent or difficult to detect in the intensive care units (ICU),
or the physical examination may be unreliable.
Most invasive devices require radiographic confirmation of position after placement,
because improper positioning may not be clinically apparent.
So,
PCXR is vital,
often providing bedside clinicians with information they otherwise would not have.
A systematic approach is essential for interpreting PCXR,
as well as any other radiographic examination [2].
These are the main steps:
To evaluate the technical quality
To locate all the external devices
To describe the cardiovascular system
To check the lung parenchyma and possible pleural effusions
To compare with prior studies
At last,
clinical session in the ICU is recommended,
with radiologists and clinical physicians,
to achieve a multidisciplinary approach to critically-ill patients.