Thoracic Ultrasound: Pictorial review of pneumothorax, the fastest and easiest method to diagnose.

Transcription

1 Thoracic Ultrasound: Pictorial review of pneumothorax, the fastest and easiest method to diagnose. Poster No.: C-1588 Congress: ECR 2014 Type: Educational Exhibit Authors: J. A. Guirola, V. Mayoral Campos, P. Menal Muñoz, N. Padron Rodriguez, B. Madariaga, M. J. Gimeno Peribáñez, B. Carro Alonso, E. Jimenez Ayllon; Zaragoza/ES Keywords: Trauma, Artifacts, Acute, elearning, Education, Diagnostic procedure, Ultrasound, Thorax, Emergency, Anatomy DOI: /ecr2014/C-1588 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 26

2 Learning objectives To review and illustrate thoracic ultrasound appearance of pneumothorax and learn a fast and easy method. To describe the use of bedside sonography for excluding small pneumothorax in misdiagnose patients obtained with conventional radiography. Page 2 of 26

3 Images for this section: Fig. 9 RADIOLOGY, HOSPITAL CLINICO UNIVERSITARIO LOZANO BLESA - Zaragoza/ ES Page 3 of 26

4 Background Pneumothorax can quickly become a life threatening pathology, and can be misdiagnose with the use of conventional chest films. Supine AP chest radiograph used in critical ill patients, pneumothorax misdiagnosis may occur up to 30% of all pneumothoraces. Brook et all, proved that efast exam shown 47 % of sensitivity to detect air within pleural space compared to a 16% of sensitivity in plain chest radiography. Thoracic sonography also shown a 99% of specificity to discard pneumothorax with the use of convex probe. Page 4 of 26

5 Images for this section: Fig. 20: Massive left side pneumothorax with right side mediastinal shift. RADIOLOGY, HOSPITAL CLINICO UNIVERSITARIO LOZANO BLESA - Zaragoza/ ES Page 5 of 26

6 Findings and procedure details To help residents and young radiologist learn the use of thoracic ultrasound is necessary to know the basic ultrasound physics and the normal pulmonary signs. Reverberation artifacts The reverberation artifact is an horizontal or vertical image that occurs when ultrasound waves bounce between two interfaces with high acoustic impedance (pleura or interlobullar septae). The waves moves up and down between these interfaces and the machine recognise them as parallel lines which have equal distances between them. This artefact known as "A lines" represents multiple parallel lines horizontal hyperechogenic lines beneath the pleural line. Fig. 1: "A Lines" Page 6 of 26

7 B lines: are narrow based hyperecogenic lines with a vertical orientation, that arise from the pleural line and extends to the edge of the ultrasound screen. This artifact is also know as "comet-tail artifacts". B lines artifact can be seen in normal patients with a 7 mm distance spacing. (normal spacing of the interlobular septae) Fig. 2: "B Lines" Z lines: It may represent like the B lines but not to be confused with these lines, because Z lines doesn't reach distally to the edge of the screen. Found in patients with no pathology, as well as in patients with pneumothorax. They are less echogenic than the pleural line, and they diminish between 2-4 cms. Also this artifact doesn't erase "A lines, and do not move with lung sliding. Page 7 of 26

8 Fig. 3: "Z Lines" E lines: Comet tail artifact seen in superficial and superior the pleural line in patients with parietal emphysema or echogenic foreign bodies in the chest wall. Page 8 of 26

9 Fig. 4: "E Lines" Normal Findings Bedside Thoracic Ultrasound. Bedside ultrasound strict decontamination protocol in each given procedure. The probe can be a convex probe 1-5MHZ or a Linear probe 7-15 MHZ. Always use a systematic and dynamic approach to obtained and interpret the ultrasound images. Also describe the position of the patients (supine, decubitus lateral, etc), as Page 9 of 26

10 well as the area of examination with the help of diagram probe positioning that every ultrasound machine has. The probe should be positioned perpendicularly between the ribs in a longitudinal orientation. Left side of the screen (ultrasound mark) should always point cephalic positioning, and the right side of the screen should correspond to caudal part Fig. 12 Thoracic ultrasound examination Divide the thorax into Upper and lower segments in each hemithorax. Also divide each segment into 4 zones. These áreas should be explore systematically which should take less than 5 minutes using both probes. Linear probe (7-15 Mhz) has a better definition image to detect pneumothorax but has a weak ultrasound wave penetration were the convex probe (2-5 Mhz) helps to detect posterior defects. Page 10 of 26

11 Fig. 5: Anterior View of Thoracic Zones. Page 11 of 26

12 Fig. 6: Lateral View of Thoracic Zones Page 12 of 26

13 Fig. 7: Posterior View of Thoracic Zones ICU patients tend to be critical ill, so thoracic ultrasound examination can be very difficult. Zone 4 is a difficult zone to examine because patients, but pneumothorax (free air between visceral and parietal pleura) usually moves freely to the most upper part of the thorax depending of the situation of the patient (supine). Page 13 of 26

14 Fig. 8: Diagram (parasagittal thoracic CT) illustrating thoracic ultrasound detecting an anterior pnemothorax that usually locates in the most anterior and superior part of the thorax, studied in a supine position. However thoracic ultrasound can detect smaller pneumothoraces compared with conventional chest radiography done with portable X-ray units. Ultrasound signs in normal healthy patients Lung Sliding The visual appearance of the pleural movement (viewed in the 2D-mode or B-mode) in every breath the patient takes or the tidal movement done by the mechanical ventilator if the patient is intubated. Page 14 of 26

15 The pleural line is made up of the visceral and parietal pleura surfaces. During respiration, the two pleural surfaces slide against each other (air displacement), and this appears as a shimmering white line. Fig. 14 Seashore sign M-mode is an effective tool with the ultrasound to detect movement, with a very sensitive and especificity to detect small pneumothorax. It's called seashore sign because it resembles a sky, ocean and beach. It is important to notice the beach part or the grainy part, because grain represents pleural movement. Page 15 of 26

16 Fig. 10 Fig. 13 The beach part in the image is obtained by the motion detected by the sliding effect of the pleura. When no movement is detected a A line pattern appears in which it resembles a sky or sunset called: Page 16 of 26

17 -Strathosphere Sign--> Pneumothorax. Fig. 11 Power slide Using the B-mode in the ultrasound and the power doppler it can easily detect the pleural movement with a laminar enhacement in the power doppler signal located in the pleural line. Page 17 of 26

18 Fig. 15 How to detect pneumothorax Abscence of lung sliding No movement is present between the pleural line with a normal patient breathing (several respiratory cycles). "A-lines" can be present in pneumothorax because A means Air so you can remember. But "B-lines" which are reverberation artifacts obtained by interlobullar septae thickening, so B-lines doesn't diagnose pneumothorax. Strathosphere sign Strathosphere sign is obtained with the M-mode observed through the pleural line between the ribs with several respiratory cycles. False positive strathosphere sign can be detected in COPD patients with small breathing movement. It is important to focus on all the thoracic zones described previously, and to ask the patient to breath heavily like a normal clinical examination is performed. If the patient is critical ill with traqueal intubation, try to notice the chest movement with serveral respiratory cycles and discard false positive strathosphere sign. Page 18 of 26

19 Fig. 11 on page 22 Abscence of power slide Abscence of laminar enhacement in the power doppler signal. Some artifacts can be obtained if the patiet breaths heavily but the doppler enhancement doesn't have a laminar morphology. Quiz 81 year old male with dysphea and chest pain. Normal ECG and cardiac enzymes. --Thoracic USG-Left hemithorax zone I = Fig. 14 on page Right hemithorax zone I= Fig. 16 on page, M-modeFig. 17 on page, M-mode Fig. 18 on page DIAGNOSIS?????? CT= Fig. 19 on page Page 19 of 26

20 Images for this section: Fig. 1: "A Lines" RADIOLOGY, HOSPITAL CLINICO UNIVERSITARIO LOZANO BLESA - Zaragoza/ ES Page 20 of 26

21 Fig. 2: "B Lines" RADIOLOGY, HOSPITAL CLINICO UNIVERSITARIO LOZANO BLESA - Zaragoza/ ES Page 21 of 26

22 Fig. 12 RADIOLOGY, HOSPITAL CLINICO UNIVERSITARIO LOZANO BLESA - Zaragoza/ ES Fig. 10 RADIOLOGY, HOSPITAL CLINICO UNIVERSITARIO LOZANO BLESA - Zaragoza/ ES Page 22 of 26

23 Fig. 11 RADIOLOGY, HOSPITAL CLINICO UNIVERSITARIO LOZANO BLESA - Zaragoza/ ES Page 23 of 26

24 Conclusion Radiologist must learn the basic thoracic ultrasound examination to discard pneumothoraces in critical ill patients with an clinical suspicion or has recently performed a central venous catherization that the main complication is a pneumothorax. Although ultrasound wave behaves very poorly within air, in has shown that thoracic ultrasound is very sensitive and specific diagnostic test to detect small pneumothorax in a fast and easy way. Page 24 of 26

25 References 1. Brook OR, Beck-Razi N, Abadi S, et al. Sonographic detection of pneumothorax by radiology residents as part of extended focused assessment with sonography for trauma. J Ultrasound Med 2009; 28: Blaivas M, Lyon M, Duggal S. A prospective comparison of supine chest radiography and bedside ultrasound for the diagnosis of traumatic pneumothorax. Acad Emerg Med 2005; 12: Cunningham J, Kirkpatrick AW, Nicolaou S, et al. Enhanced recognition of "lung sliding" with power color Doppler imaging in the diagnosis of pneumothorax. J Trauma 2002; 52: Kirkpatrick AW, Sirois M, Laupland KB, et al. Hand-held thoracic sonography for detection post-traumatic pneumothoraces: the extended focused assessment with sonography for trauma (EFAST). J Trauma 2004; 57: Lichtenstein DA, Mezière G, Lascols N, et al. Ultrasound diagnosis of occult pneumothorax. Crit Care Med 2005; 33: Feldman MK, Katyal S, Blackwood MS. US artifacts. Radiographics JulAug;29(4): Abu-Zidan FM, Hefny AF, Corr P. Clinical ultrasound physics. J Emerg Trauma Shock Oct;4(4): doi: / PubMed PMID: ; PubMed Central PMCID: PMC Lichtenstein DA, Mezière GA, Lagoueyte JF, Biderman P, et al. A-lines and B-lines: lung ultrasound as a bedside tool for predicting pulmonary artery occlusion pressure in the critically ill. Chest Oct;136(4): Lichtenstein DA. Ultrasound in the management of thoracic disease. Crit Care Med Jun;33(6): Lichtenstein DA, Mauriat P. Lung Ultrasound in the Critically Ill Neonate. Page 25 of 26

26 Curr Pediatr Rev Aug;8(3): Page 26 of 26