**6. Ultrasound-guided intervention**

#### **6.1. Diagnostic thoracentasis**

The aim of the initial assessment of pleural fluid is to identify malignancy or infection and starts with a visual inspection of the aspirate prior to laboratory analysis. Therefore diagnostic thoracentesis is mandatory. When performed with image guidance thoracentesis provides clinically useful information in more than 90% of cases. If the pleural effusion spans three intercostal spaces and its presence can be confirmed clinically by percussion then aspiration can be performed safely at the bedside without the aid of image guidance. When the effusion is small, loculated or associated with underlying pulmonary collapse this becomes more difficult and hazardous. In all these situations US examination is required to confirm the presence of fluid and to guide thoracentesis. Moreover, bed-side procedures are sometimes necessary due to patient debilitation and can be performed satisfactorily with a portable US machine. By performing the aspiration at the time of the US examination success rates will be optimized and complication rates kept to a minimum. The most commonly reported compli‐ cation for non-guided thoracentesis is that of pneumothorax with published rates varying from 11 to 12%. When US-guidance diagnostic thoracentesis is performed the complication rates fall to between 0.2% and 2.7% [18].

#### **6.2. Ultrasound-guided small-bore chest tube insertion**

Chest US also can be used guidance for small-bore catheter (pigtail tube) insertion and also provide a safe and effective method of draining various pleural diseases which includes pneumothorax, malignant pleural effusion, para-pneumonic effusion/empyema, and massive transudate effusions [19]. In primary spontaneous pneumothorax patients, ultrasound-guided pigtail catheter drainage is effective and had a shorter hospital stay than patients treated by chest tube drainage [20]. Moreover, US-guided pigtail catheter for secondary spontaneous pneumothorax (SSP) is also effective and has low complication rate. A higher treatment failure rate was noted in infectious related SSP patients [21, 22]. In mechanically ventilated patients, US-guided pigtail catheter drainage is also effective in treating iatrogenic pneumothorax [23].

#### **6.3. Ultrasound-guided biopsy**

**Figure 10.** Lung comets. Lung comet tail, also known as 'B lines' (arrows) are indicative an alveolar interstitial syn‐

The aim of the initial assessment of pleural fluid is to identify malignancy or infection and starts with a visual inspection of the aspirate prior to laboratory analysis. Therefore diagnostic thoracentesis is mandatory. When performed with image guidance thoracentesis provides clinically useful information in more than 90% of cases. If the pleural effusion spans three intercostal spaces and its presence can be confirmed clinically by percussion then aspiration can be performed safely at the bedside without the aid of image guidance. When the effusion is small, loculated or associated with underlying pulmonary collapse this becomes more difficult and hazardous. In all these situations US examination is required to confirm the presence of fluid and to guide thoracentesis. Moreover, bed-side procedures are sometimes necessary due to patient debilitation and can be performed satisfactorily with a portable US machine. By performing the aspiration at the time of the US examination success rates will be optimized and complication rates kept to a minimum. The most commonly reported compli‐ cation for non-guided thoracentesis is that of pneumothorax with published rates varying from 11 to 12%. When US-guidance diagnostic thoracentesis is performed the complication rates

Chest US also can be used guidance for small-bore catheter (pigtail tube) insertion and also provide a safe and effective method of draining various pleural diseases which includes pneumothorax, malignant pleural effusion, para-pneumonic effusion/empyema, and massive transudate effusions [19]. In primary spontaneous pneumothorax patients, ultrasound-guided

drome.

**6. Ultrasound-guided intervention**

90 Advancements and Breakthroughs in Ultrasound Imaging

**6.1. Diagnostic thoracentasis**

fall to between 0.2% and 2.7% [18].

**6.2. Ultrasound-guided small-bore chest tube insertion**

Transthoracic needle biopsy with fluoroscopic or computed tomographic (CT) guidance is a well-established and safe method for diagnosing malignant and benign thoracic lesions. However, radiation exposure is considerable and the cost is relatively high, as compared with US guidance. US is as effective as CT for guidance of transthoracic biopsies of peripheral pulmonary lesions and mediastinal tumors and offers a number of advantages. Real-time US imaging allows for dynamic evaluation of vessels and localization of target lesions that move during respiration. In US-guided transthoracic biopsy, the tip of the needle can be monitored throughout the procedure and fine adjustments can be made quickly and precisely; this is especially beneficial for biopsy of small thoracic lesions [24, 25]. Pleural biopsy is required for unexplained pleural effusions, pleural thickening (whether focal or diffuse) and pleural masses. The advances in imaging of the pleura provided by US and CT have meant that radiologists now play an important role in pleural biopsy either directly or indirectly. In most instances biopsies are performed to establish whether or not pleural disease is due to malig‐ nancy or to evaluate a suspected inflammatory process such as tuberculosis. Because focal pleural thickening or pleural tumors can be easily identified by US, US-guided pleural biopsy is related to possible focal pleural involvement in various diseases such as pleural tumor, thickening pleura, and small amounts of pleural effusion [26]. Besides, in critically ill patients, chest US is helpful in diagnosis and is a useful diagnostic tool for critically ill patients with chest disease [27].

#### **6.4. Endobronchial Ultrasound (EBUS)**

Endobronchial ultrasound (EBUS) technology is a relatively new bronchoscopic method of visualizing the tracheobronchial tree, the surrounding pulmonary parenchyma, and the mediastinal structures, with a particular role in lung cancer diagnosis, staging, and treatment [28]. There are 2 types of probes used in EBUS: the peripheral or radial probe (RP) and the linear or convex probe (CP) EBUS, which have technical differences and distinct diagnostic abilities. Both are used for EBUS-guided biopsies and transbronchial needle aspirations (TBNA), which increases the diagnostic yield over conventional bronchoscopic techniques, thus providing advanced information on staging, diagnosis, and treatment. The 20-MHz RP-EBUS (Figure 11) is positioned inside a water-inflatable balloon and is inserted through the working channel of the bronchoscope. The RP-EBUS was first introduced to evaluate the central airway structure. With advances in technology, the small radial probes can now visualize and assist transbronchial biopsies of peripheral lung nodules without exposure to radiation. Kurimoto and colleagues [29] showed that using a guide sheath with radial probe EBUS and leaving it there to pass the forceps catheter through it could improve the diagnostic yield of specimens from peripheral pulmonary lesions/nodules, including those too small to be visualized by fluoroscopy. Nowadays, the evaluation of mediastinal lesions has been facilitated by the use of CP-EBUS probe. This type of probe incorporates a 7.5-MHz ultrasound transducer at the tip of a flexible bronchoscope. Real-time biopsies of the lymph nodes can be carried out with a 22-gauge needle inserted through the working channel. EBUS-TBNA is most commonly used for staging non-small cell lung cancer (NSCLC), but is also used for diagnosis of unexplained mediastinal lymphadenopathy (Figure 12) of other causes. The safety of this technique is well established and few serious complications have been reported, including pneumothorax, pneumomediastinum, and hemomediastinum [30, 31].

**7. Conclusions**

abnormality.

**Author details**

**References**

Hung-Jen Chen1,2 and Hsu Wu-Huei1,2

\*Address all correspondence to: chesttu@gmail.com

na Medical University Hospital, Taichung, Taiwan

2 China Medical University, Taichung, Taiwan

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Pleural US has a proven role in improving the safety of pleural procedures and should be offered as standard of care in this setting. US also offers advantages over conventional radiography in the detection, quantification and characterisation of pleural effusions. Lung US has excellent test characteristics for the diagnosis of consolidation, interstitial syndrome and subpleural pulmonary nodules. EBUS based technology may be used in the diagnosis of a lung or mediastinal lesion, staging of lung cancer, and treatment of an endobronchial

Ultrasound Diagnosis of Chest Diseaseses http://dx.doi.org/10.5772/55419 93

In the future, chest sonography is likely to be an essential skill for the physician, and training

1 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Chi‐

[1] Eibenberger KL, Dock WI, Ammann ME, et al. Quantification of pleural effusions: so‐

[2] Yang PC, Luh KT, Chang DB, et al. Value of sonography in determining the nature of pleural effusion: analysis of 320 cases. AJR Am J Roentgenol 1992;159 29-33.

[3] Hirsch JH, Rogers JV, Mack LA. Real-time sonography of pleural opacities. AJR Am J

[4] Chen HJ, Tu CY, Ling SJ, et al. Sonographic appearances in transudative pleural effu‐ sions: not always an anechoic pattern. Ultrasound Med Biol 2008;34 362-369.

[5] Tsai TH, Yang PC. Ultrasound in the diagnosis and management of pleural disease.

requirements are likely to evolve with advances in the field.

Wei-Chih Liao1,2, Chih-Yen Tu1,2,3\*, Chuen-Ming Shih1,2, Chia-Hung Chen1,2,

3 Department of Life Science, National Chung Hsing University, Taiwan

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**Figure 11.** Radial Probe Endobronchial Ultrasound. Left, probe and deflated balloon. Right, probe within a broncho‐ scope with balloon inflated.

**Figure 12.** Image of a lymph node biopsy under endobronchial ultrasound guidance. Real-time EBUS-TBNA revealed a lymph node of 1.69 cm (A). The needle (arrows) is clearly visible in the lymph node (B).
