Ultrasound-guided core biopsy of thoracic tumors

Ultrasound-guided core-needle biopsy for peripheral pulmonary lesions: a systematic review and meta-analysis

AIM

To evaluate the diagnostic value and safety of ultrasound-guided core-needle biopsy for peripheral pulmonary lesions (PPLs).

MATERIALS AND METHODS

PubMed, EMBASE, and the Cochrane Library for relevant were searched for studies published up to June 2022. The diagnostic accuracy of US-guided percutaneous transthoracic needle biopsy (PTNB) for the diagnosis of PPLs was evaluated using pooled sensitivity, specificity, diagnostic odds ratio (DOR), positive and negative likelihood ratios (PLR and NLR), and the area under the summary receiver operating characteristic curves value (SROC).

RESULTS

The search included 12 original studies (3,830 procedures). For US-guided PTNB, the pooled sensitivity and specificity for the diagnosis of PPLs were 0.93 (95% confidence interval [CI]: 0.91-0.94) and 0.99 (95% CI: 0.96-1.00), respectively. The pooled estimates of the PLR, NLR, and DOR were 134.88 (95% CI: 24.88-731.74), 0.07 (95% CI: 0.06-0.09), and 1,814.95 (95% CI: 333.62-9,873.76), respectively. The area under the SROC curve was 0.95 (95% CI: 0.93-0.97). The overall complication rate was 3.6% (136 of 3,830), including self-limited haemoptysis and asymptomatic pneumothorax, and only six cases of pneumothorax requiring chest tube drainage and one case of severe bleeding were reported.

CONCLUSIONS

US-guided core-needle biopsy is an excellent diagnostic tool for PPLs, with high accuracy and excellent technical performance and safety.

Hemoptysis complicating ultrasound-guided transthoracic needle lung biopsy: air bronchial sign is a risk predictor

Background

Hemoptysis is the most frequently reported complication of ultrasound-guided transthoracic needle lung biopsy (US-TTLB). However, factors influencing the occurrence of hemoptysis as a result of US-TTLB remain uncertain. Therefore, the aim of this study was to evaluate the incidence of hemoptysis as a complication of US-TTLB and to identify the related risk factors.

Methods

We retrospectively analyzed all data of patients who underwent US-TTLB from February 2013 through December 2016. The incidence, severity, and treatment of hemoptysis in each case were carefully recorded. Study variables were classified into patient-related factors (age, sex, smoking history, pulse oxygen saturation, laboratory tests and emphysema), biopsy-related factors (use of contrast agent, number of punctures and operators), and lesion-related factors (lesion location, size, pathology, length of puncture path and the grade of air bronchial sign). Univariate and multivariate logistic regression analyses were performed to analyze the risk factors of hemoptysis. We investigated whether incidence of hemoptysis increased according to increased grade of air bronchial sign by Mantel-Haenszel test.

Results

A total of 209 patients were evaluated. Hemoptysis occurred in 20 of the 209 patients (9.6%). In univariate analysis, the lesion pathology (P=0.037) and grade of air bronchial sign (P<0.001) were statistically significant factors between the hemoptysis group and the non-hemoptysis group. In multivariate analysis, the presence of multi-air bronchogram in sonographic image (odds ratio =8.946; 95% confidence interval: 2.873–27.863; P<0.001) was a statistically significant predictive risk factor for hemoptysis complicating US-TTLB. There was a significant tendency for incidence of hemoptysis with the grade of air bronchial sign (P<0.001).

Conclusions

We found that the rate of hemoptysis complicating US-TTLB was 9.6% and the severity of hemoptysis was not serious. Target lesion without air bronchogram is a safety sign, minor bronchogram means relatively low-risk, while multiple bronchogram is a highly dangerous ultrasound sign of hemoptysis.

Diagnostic value and complication rate of ultrasound-guided transthoracic core needle biopsy in mediastinal lesions

BACKGROUND

Ultrasound-guided transthoracic core needle biopsy (US-TCNB) is a promising method for establishing the correct diagnosis of mediastinal masses. However, the existing studies in this area are scant and with small samples.

PURPOSE

To evaluate the diagnostic value and the complication rate of US-TCNB, particularly large bore cutting biopsy in patients with mediastinal lesions.

MATERIAL AND METHODS

This retrospective study includes 566 patients with mediastinal lesions suspicious of malignancy evaluated between March 2004 and December 2018. Inclusion criteria: 1. Patients with mediastinal lesions detected on thoracic CT scan; 2. Lesions more than 15 mm; 3. Negative histological diagnosis after bronchoscopic biopsy; 4. Normal coagulation status; 5. Cooperative patient; 6. Written informed consent. US visualization of the mediastinal lesions was successful in 308 (54.4%). In all of them, US-TCNB was performed. All patients with mediastinal lesions unsuitable for US visualization were evaluated for a CT-guided transthoracic needle biopsy (CT-TTNB), which was done if the presence of a safe trajectory was available (n = 41, 7.2%). All patients inappropriate for image-guided TTNB were referred to primary surgical diagnostic procedures (n = 217, 38.3%).

RESULTS

The US-TCNB is a highly effective (accuracy 96%, sensitivity 95%) and safe tool (2.6% complications) in the diagnosis of all subgroups mediastinal lesions. It is non-inferior to CT-TTNB (90%) and comes close to the effectiveness of surgical biopsy techniques (98.4%), but is less invasive and with a lower complication rate.

CONCLUSION

US-TCNB of mediastinal lesions is highly effective and safe tool which is particularly helpful in critically ill patients.

Ultrasound of the pleurae and lungs

The value of ultrasound techniques in examination of the pleurae and lungs has been underestimated over recent decades. One explanation for this is the assumption that the ventilated lungs and the bones of the rib cage constitute impermeable obstacles to ultrasound. However, a variety of pathologies of the chest wall, pleurae and lungs result in altered tissue composition, providing substantially increased access and visibility for ultrasound examination. It is a great benefit that the pleurae and lungs can be non-invasively imaged repeatedly without discomfort or radiation exposure for the patient. Ultrasound is thus particularly valuable in follow-up of disease, differential diagnosis and detection of complications. Diagnostic and therapeutic interventions in patients with pathologic pleural and pulmonary findings can tolerably be performed under real-time ultrasound guidance. In this article, an updated overview is given presenting not only the benefits and indications, but also the limitations of pleural and pulmonary ultrasound.

Diagnostic impact of color Doppler ultrasound-guided core biopsy on fine-needle aspiration of anterior mediastinal masses

Although lymphoma and thymoma are common etiologies of anterior mediastinal masses (AMMs), smaller percentages and numbers of patients with these diseases have been enrolled in previous ultrasound-guided biopsy studies. To date, there has been no study of color Doppler sonographic features to support the differentiation of AMMs. For this retrospective cohort study, a search of the database of the China Medical University Hospital using the clinical coding "ultrasound-guided biopsy" was conducted for the period December 2003 to February 2013. We selected patients diagnosed with AMMs (not cysts) using radiographic records. This search yielded a list of 80 cases. Real-time ultrasound-guided core needle biopsy (CNB) was performed in all but 5 patients without a sufficient safety range. In 89% (67/75) of these ultrasound-guided CNB cases, the diagnostic accuracy achieved subclassification. Fine-needle aspiration cytology achieved subclassification in only 10% of cases. On color Doppler sonography, 71% of lymphomas were characterized as "rich vascular with central/crisscross collocations" and 29% as "avascular or localized/scattered peripheral vessels." However, decreased proportions of "rich vascular with central/crisscross collocations" were found in lung cancer (4% [1/23], odds ratio = 0.018, 95% confidence interval: 0.002-0.154, p < 0.001) and thymoma/thymic carcinoma (25% [4/16]; odds ratio = 0.133, 95% confidence interval: 0.035-0.514, p = 0.003) compared with the lymphoma group. We conclude that the vessels in lymphoma AMMs have specific patterns on color Doppler sonography. Ultrasound-guided CNB of AMMs had an accuracy of ≤ 89% in diagnosis and subclassification. Fine-needle aspiration cytology itself cannot aid in the diagnosis. Color Doppler sonographic evaluation of AMMs followed by real-time CNB is a more efficient method.

US-guided transthoracic biopsy of peripheral lung lesions: pleural contact length influences diagnostic yield

BACKGROUND

Transthoracic biopsy of peripheral lung lesions under ultrasonography (US) guidance is a useful diagnostic technique. However, factors affecting diagnostic yield of US-guided transthoracic biopsy of peripheral lung lesions are not well established.

PURPOSE

To determine the factors that influence diagnostic yield of US-guided transthoracic biopsy in peripheral lung lesions.

MATERIAL AND METHODS

A total of 100 consecutive patients underwent US-guided percutaneous cutting biopsy of peripheral lung lesions from October 2007 to March 2009. After seven unconfirmed cases were excluded, 97 procedures in 93 consecutive patients were included in this study. The accuracy of the lung biopsies was assessed by comparing the biopsy results with the final diagnoses. We divided the cases into a correct group (true-positive and true-negative) and an incorrect group (false-positive, false-negative, and non-diagnostic results) and analyzed the differences in the lesions, procedures, and patient variables between the two groups.

RESULTS

According to the final diagnoses, 56 cases (57.7%) were malignant and 41 cases (42.3%) were benign. An overall diagnostic accuracy of 91.8% was obtained. The median size of the lesions was 46.0 mm (interquartile range [IQR], 30.0-69.5 mm), and the median lesion-pleura contact arc length (LPCAL) was 31.0 mm (IQR, 18.0-51.0 mm). Multivariate logistic regression analysis showed that only LPCAL (odds ratio, 1.16; 95% CI, 1.04-1.30) was a significant predictor of a correct diagnosis. When we divided the lesions into those with LPCAL values >30 mm and LPCAL values ≤30 mm, the sensitivity (96.6% vs. 74.1%; P = 0.02) and the accuracy (98% vs. 85.4%; P = 0.03) were significantly higher in the group with larger LPCAL.

CONCLUSION

In US-guided transthoracic biopsy of peripheral lung lesions, the LPCAL of the lesions is an important factor for a correct diagnosis.

Ultrasonography for clinical decision-making and intervention in airway management: from the mouth to the lungs and pleurae

OBJECTIVES

To create a state-of-the-art overview of the new and expanding role of ultrasonography in clinical decision-making, intervention and management of the upper and lower airways, that is clinically relevant, up-to-date and practically useful for clinicians.

METHODS

This is a narrative review combined with a structured Medline literature search.

RESULTS

Ultrasonography can be utilised to predict airway difficulty during induction of anaesthesia, evaluate if the stomach is empty or possesses gastric content that poses an aspiration risk, localise the essential cricothyroid membrane prior to difficult airway management, perform nerve blocks for awake intubation, confirm tracheal or oesophageal intubation and facilitate localisation of tracheal rings for tracheostomy. Ultrasonography is an excellent diagnostic tool in intraoperative and emergency diagnosis of pneumothorax. It also enables diagnosis and treatment of interstitial syndrome, lung consolidation, atelectasis, pleural effusion and differentiates causes of acute breathlessness during pregnancy. Patient safety can be enhanced by performing procedures under ultrasound guidance, e.g. thoracocentesis, vascular line access and help guide timing of removal of chest tubes by quantification of residual pneumothorax size.

CONCLUSIONS

Ultrasonography used in conjunction with hands-on management of the upper and lower airways has multiple advantages. There is a rapidly growing body of evidence showing its benefits.

TEACHING POINTS

• Ultrasonography is becoming essential in management of the upper and lower airways. • The tracheal structures can be identified by ultrasonography, even when unidentifiable by palpation. • Ultrasonography is the primary diagnostic approach in suspicion of intraoperative pneumothorax. • Point-of-care ultrasonography of the airways has a steep learning curve. • Lung ultrasonography allows treatment of interstitial syndrome, consolidation, atelectasis and effusion.

Role of thoracic ultrasound in the assessment of pleural and pulmonary diseases

Although numerous studies have been conducted on the use of ultrasonography (US) for the examination of thoracic structures, this procedure is not as widely accepted as abdominal US. The newer portable scanners can be used at the bedside to detect pleural malignancies and effusions, as well as peripheral lung nodules of the lung, even in seriously ill patients. Focal thickening of the pleura can be easily detected with US and further investigated with a US-guided biopsy. US guidance can also be used during percutaneous drainage of pleural effusion or transthoracic biopsy of peripheral lung lesions, thus reducing the incidence of procedure-related pneumothorax to almost zero. We review the current literature on thoracic US and present our clinical experience with the technique in large groups of patients with pleural and peripheral lung diseases.

Dynamic flow US, color Doppler US, and power Doppler US in the assessment of vessel signals of thoracic lesions abutting pulsatile organs

RATIONALE AND OBJECTIVES

Dynamic flow ultrasound (DFUS) is a new color Doppler imaging method with better B-mode imaging and fewer blooming effects and color noises. This study was designed to compare the imaging quality of vessel signals in thoracic lesions using DFUS, color Doppler US (CDUS), and power Doppler US (PDUS).

MATERIALS AND METHODS

Thirty-four patients with thoracic lesions abutting pulsatile organs [heart (n = 13), aorta (n = 14) and pulmonary artery (n = 7)] and undergoing complete chest US examinations were included to assess the imaging quality about vessel signals, blooming effect, color noise, and the influence of decision in needle biopsy between different US modes.

RESULTS

Our results showed that DFUS, CDUS, and PDUS could all demonstrate the vessel signals clearly (all P > .05). However, when focusing on the blooming effect and color noise, DFUS showed the more superior imaging quality than CDUS and PDUS (all P < or = .001); and acceptable blooming effects/color noise were found with 100% (34/34)/97% (33/34), 35% (12/34)/68% (23/34), and 26% (9/34)/38% (13/34) in DFUS, CDUS, and PDUS, respectively. Especially, in the assessment of decision making for percutaneous needle biopsy, DFUS had the less influence than CDUS and PDUS (3% [1/33] versus 29% [10/34] and 3% [1/33] versus 38% [13/34], both P < .01).

CONCLUSIONS

We concluded that DFUS has a clearly more superior imaging quality than CDUS and PDUS in demonstrating the vessel signals of thoracic lesions, with less blooming effect and color noise.

Transthoracic ultrasound for the pulmonologist

PURPOSE OF REVIEW

Transthoracic ultrasound has received increased interest from chest physicians in recent years. Modern ultrasound devices are user friendly, inexpensive, lightweight, and portable, which makes them suited for outpatient settings as well as for bedside investigation of the severely ill. Ultrasound is set to become a practical and essential tool for the pulmonologist in the near future.

RECENT FINDINGS

An ever-increasing number of articles are aimed at describing and refining how ultrasound can be utilised by chest physicians in daily practice. Only basic ultrasound skills are required to assess pleural effusions and perform ultrasound-guided thoracocentesis. Sonographic assistance with insertion of chest drains as well as identification or biopsy of thoracic masses are more complex, and advanced skills are required for the investigation of pneumothorax and thromboembolic disease.

SUMMARY

The current literature documents the progress in the application of ultrasound for the practicing chest physician. In this article the authors describe the most recent developments and follow up with some simple but essential advice for the novice venturing into chest ultrasound.

Ultrasound in the diagnosis and management of pleural disease

The authors summarize the current applications of chest ultrasonography in the diagnosis and management of various pleural diseases. Ultrasound has been proved to be valuable for the evaluation of a wide variety of chest diseases, particularly when the pleural cavity is involved. Chest ultrasound can supplement other imaging modalities of the chest and guides a variety of diagnostic and therapeutic procedures. Pleural effusion, pleural thickening, pleural tumors, tumor extension into the pleura and even the chest wall, pleuritis, and pneumothorax can be detected easily and accurately with chest ultrasound. Many ultrasound features and signs of these diseases have been well characterized and widely applied in clinical practice. Under real-time ultrasound guidance the success rates of invasive procedures on pleural diseases increase significantly whereas the risks are greatly reduced. The advantages of low-cost, bedside availability and no radiation exposure have made ultrasound an indispensable diagnostic tool in modern pulmonary medicine.

Mature mediastinal teratoma: sonographic imaging patterns and pathologic correlation

OBJECTIVE

To characterize the sonographic patterns of teratomas located within the mediastinum and to correlate them with pathologic findings, because there have been few reports concerning the application of sonography in the diagnosis of mediastinal teratoma.

METHODS

Over a 9-year period, we carried out an image analysis of the sonographic findings of 28 mediastinal teratomas whose diagnoses were proved surgically.

RESULTS

Sonography showed that 18 patients had a complex mass of heterogeneous echogenicity, including regional bright echoes (n = 12), acoustic shadows (n = 8), hyperechoic lines and dots (n = 7), soft tissue septa (n = 9), dermoid plugs (n = 6), and hypoechoic areas (n = 11). This type of mediastinal teratoma revealed, in pathologic findings, varying combinations of fat, sebaceous and mucinous materials, hair, mineralized elements, and multiple compartments. Eight patients had a homogeneous hyperechoic mass, and the 2 remaining patients had floating spherules within a cystic mass. Pathologically, the homogeneous mass mainly contained hair and sebaceous material. The floating spherules were also composed of sebaceous tissue and were above the fluid of the cyst.

CONCLUSIONS

On the basis of the evaluation of the sonographic and pathologic findings, we described 3 major patterns of mediastinal teratoma: a complex mass of heterogeneous echogenicity, homogeneous high echogenicity within a solid mass, and floating spherules within a cystic mass. Thus, sonography can improve the diagnosis of mediastinal teratoma. However, additional prospective studies are needed to test the sensitivity and specificity of these sonographic patterns in the diagnosis of mediastinal teratoma.

Bronchoscopy and needle biopsy techniques for diagnosis and staging of lung cancer

Lung cancer is the leading cause of cancer deaths in the United States. The individual therapeutic approach and prognosis depends on accurate diagnosis and staging. Flexible bronchoscopy (FB) and transthoracic needle biopsy (TNB) are the most widely used techniques for this purpose. This article provides a critical overview of indications, diagnostic yield, and limitations of bronchoscopy and TNB in the diagnosis of lung cancer.

Transthoracic US of the chest: clinical uses and applications

Transthoracic ultrasound (US) of the chest is useful in the evaluation of a wide range of peripheral parenchymal, pleural, and chest wall diseases. Furthermore, it is increasingly used to guide interventional procedures of the chest and pleural space. The technique lends itself to bedside use in the intensive care unit, where suboptimal radiography may mask or mimic clinically significant abnormalities. The authors discuss the uses, techniques and applications of US of the chest. The sonographic appearances of pleural diseases (pleural effusion, pneumothorax, pleural mass, and mesothelioma), parenchymal diseases (pneumonia, neoplasms, heart failure, infarct, and rounded atelectasis), chest wall abnormalities (chest wall tumor and rib fracture), and diaphragmatic paralysis are discussed. The use of US in guiding biopsy, thoracocentesis, and other interventional procedures of the lung, pleural space, and mediastinum are also reviewed.

Imaging guided thoracic interventions

Interventional Radiology is a technique based medical specialty, using all available imaging modalities (fluoroscopy, ultrasound, computed tomography, magnetic resonance, angiography) for guidance of interventional techniques for diagnostic or therapeutic purposes. Actual, percutaneous transthoracic needle biopsy includes core needle biopsy besides fine needle aspiration. Any pleural, pulmonary or mediastinal fluid or gas collection is amenable to percutaneous pulmonary catheter drainage. Treatment of haemoptysis of the bronchial artery or pulmonary artery origin, transcatheter embolization of pulmonary arteriovenous malformations and pseudoaneurysms, angioplasty and stenting of the superior vena caval system and percutaneous foreign body retrieval are well established routine procedures, precluding unnecessary surgery. These techniques are safe and effective in experienced hands. Computed tomography is helpful in pre- and postoperative imaging of patients being considered for endobronchial stenting. Many procedures can be performed on an outpatient basis, thus increasing the cost-effectiveness of radiologically guided interventions in the thorax.

Value of chest sonography in the diagnosis and management of acute chest disease

PURPOSE

The aim of this study was to investigate the value of chest sonography in the diagnosis and management of patients with chest radiograph opacities in an emergency department.

METHODS

Seventy-eight patients with acute chest complaints whose chest radiographs showed opacities underwent chest sonography. The initial diagnosis (based on clinical manifestations and the chest radiograph), the sonographic diagnosis (before any invasive procedures), and the final diagnosis were compared. The impact of chest sonography on the management of patients with chest opacities was also analyzed.

RESULTS

The initial diagnosis was in concordance with the final diagnosis in 60 (77%) of the 78 patients, while the sonographic diagnosis was in concordance with the final diagnosis in 75 (96%) of the patients. Chest sonography therefore significantly increased the rate of correct diagnoses from 77% (95% confidence interval, 67-87%) to 96% (95% confidence interval, 92-100%; p < 0.0001). Sonography provided new information in 52 patients (67%): a different diagnosis from the initial diagnosis in 18 patients and additional diagnostic information in 34 patients. New information gained from sonography affected the management of 35 patients. Sonography also provided help in guiding 42 (70%) of 60 invasive diagnostic procedures and 22 (73%) of 30 invasive therapeutic procedures for which chest radiography and physical examination had failed to or were unsuitable to provide guidance. Overall, sonography assisted in the management of 64 (82%) of 78 patients. Sonography was of no benefit in 14 patients (18%).

CONCLUSIONS

We conclude that chest sonography can complement chest radiography and is of value in the diagnosis and management of emergency department patients with acute chest diseases presenting as opacities on chest radiographs.

US-guided transthoracic cutting biopsy for peripheral thoracic lesions less than 3 cm in diameter

PURPOSE

To evaluate the safety and accuracy of ultrasonography (US)-guided transthoracic cutting biopsy for diagnosing peripheral thoracic lesions (<3 cm).

MATERIALS AND METHODS

Fifty consecutive patients with peripheral thoracic lesions less than 3 cm in diameter underwent US-guided percutaneous transthoracic cutting biopsy with a modified technique. Fifty lesions (43 parenchymal lung, two pleural, two chest wall, and three anterior mediastinal lesions) were sampled for biopsy. The final diagnosis was based on histopathologic analysis of surgical specimens (n = 18) or clinical follow-up (n = 32).

RESULTS

The histology recovery rate was 98% (49 lesions), and the correct diagnosis was obtained in 48 lesions (96%). Twenty-four (48%) lesions were malignant, and 26 (52%) were benign. The diagnostic accuracy for malignant lesions was 92% (22 of 24 lesions). A specific benign diagnosis was made in 17 (65%) of the 26 benign lesions, and the negative predictive value for malignancy was 93% (26 of 28 lesions). Only two patients (4%) developed postbiopsy pneumothorax, and three (6%) developed postbiopsy hemoptysis. Biopsy helped prevent surgery or thoracoscopy in 32 patients (64%): 18 patients with benign disease and 14 with multiple metastases or inoperable cancer.

CONCLUSION

US-guided transthoracic cutting biopsy appears to be a safe and effective method for diagnosing peripheral thoracic lesions less than 3 cm in diameter. The high diagnostic accuracy for benign lesions and metastatic lung cancer can help prevent surgery in many cases.

Semi-invasive and invasive procedures for the diagnosis and staging of lung cancer. I. Percutaneous transthoracic needle biopsy

PTNB is a well-established technique for the diagnosis of lung cancer. In recent years, CT guidance has become the primary imaging modality, replacing fluoroscopy guided biopsies in many institutions. CT fluoroscopy, which is currently not universally available, offers promising advantages and may permit accurate and rapid procedures. A recent innovation in biopsy needles has been the introduction of automatic core biopsy needle devices that yield large specimens and improve the diagnostic accuracy of needle biopsy, particularly in benign lesions. PTNB is one of several methods available for tissue diagnosis of suspected lung cancer. The decision as to which method to use should be tailored to each patient, and is preferably reached by a team consisting of pulmonary physicians, chest surgeons, oncologists, cytologists, and radiologists.

Ultrasound-guided transthoracic biopsy of the chest

Recent studies have confirmed that US is a very useful diagnostic tool for various diseases of the chest. The image information provided by US is helpful for etiologic diagnosis and clinical management. US-guided needle biopsy provides a precise and safe approach for transthoracic tissue sampling of lesions. The diagnostic yield is high, and the procedure is relatively easy and very safe. Color Doppler US and amplitude US angiography further extend the diagnostic potential and safety of this invasive procedure. Vascular information can be obtained and the needle shaft can be visualized clearly while conducting a biopsy. US examination and US-guided needle aspiration biopsy have now become indispensable diagnostic tools for various chest diseases.

Transthoracic needle biopsy

Transthoracic needle biopsy (TNB) has emerged as the semi-invasive technique of choice for the diagnosis of localized intrathoracic lesions. Using CT, fluoroscopic, or sonographic guidance, TNB is highly accurate and safe when combined with expert pathologic interpretation of the aspirated specimen. This article details the preprocedural evaluation of the patient referred for TNB and discusses the technical aspects of performing the biopsy and processing and interpreting the material obtained. The reported results and complications of TNB are reviewed and followed by a brief description of the cost effectiveness of the technique and a comparison with alternative semi-invasive diagnostic techniques including bronchoscopic and video-assisted thoracoscopic biopsy.

Interventional techniques in the thorax

Transthoracic needle biopsy (TNB) has become the diagnostic procedure of choice in evaluation of focal chest lesions. Both advances in cross-sectional image guidance and cytopathologic techniques allow TNB to accurately diagnose malignancy and characterize a spectrum of benign conditions. Image-guided percutaneous drainage of intrathoracic collections has developed as an extension of similar procedures in the abdomen and pelvis. The ability of CT and ultrasound to accurately detect and characterize parenchymal and pleural collections, and advances in interventional techniques and catheter design, have made percutaneous catheter drainage the treatment of choice for a variety of intrathoracic collections. This article provides an updated review of the spectrum of image-guided diagnostic and therapeutic procedures in the thorax.

Ultrasonography of the thorax (excluding the heart)

Until recently, ultrasonography has had a subordinate role in the evaluation of the thorax in both small animals and humans, most likely due to the inability of sound to penetrate air-filled lung. When pathologic processes such as pleural effusion and lung consolidation provide an acoustic window to the thorax, however, thoracic ultrasonography becomes feasible. As this article illustrates, ultrasonography may be effectively employed in the diagnosis and management of various thoracic wall, pleural, mediastinal, pulmonary, and diaphragmatic diseases by providing valuable information not obtainable with routine radiography and enabling percutaneous aspiration or tissue core biopsy of lesions.

Diagnosis of pulmonary arteriovenous malformations by colour Doppler ultrasound and amplitude ultrasound angiography

BACKGROUND

The clinical value of colour Doppler ultrasound and amplitude ultrasound angiography in the diagnosis and follow up of pulmonary arteriovenous malformations (PAVM) was investigated.

METHODS

Six consecutive patients suspected by clinical appearance and abnormal chest radiographic findings of having PAVM were included in the study. Ultrasonography was performed first by real time grey scale imaging then by colour Doppler imaging and amplitude ultrasound angiography in a random order. All were later proved by angiography to have PAVM.

RESULTS

The ultrasound study was successfully performed in all six patients. A total of eight lesions was detected. The real time grey scale image of PAVM revealed well defined hypoechoic subpleural nodules with strong posterior acoustic enhancement. Colour Doppler ultrasound of PAVM showed turbulent flow, manifest as an area of intense colour with high and mixed velocities (reticulated or mosaiclike pattern). Anatomical continuity was demonstrated in some PAVM. Amplitude ultrasound angiography can delineate a tangled vascular structure with a clear vessel wall and anatomical continuity as well as conventional angiography. Spectral wave analysis showed a relatively low impedance flow presenting with high peak systolic velocity (mean 44.4 cm/s) and relatively high diastolic velocity (mean 19.3 cm/s). The mean pulsatility index (PI) and resistive index (RI) were 1.80 and 0.49, respectively. In two patients who received embolotherapy the colour Doppler ultrasound scan obtained after the procedure showed that the previous focal areas of colour flow signals disappeared or diminished in size. This was compatible with the decrease in, or absence of, blood flow demonstrated by angiography after embolotherapy.

CONCLUSIONS

Combined colour Doppler ultrasound and amplitude ultrasound angiography are useful non-invasive techniques for diagnosis PAVM and provide an alternative approach to angiography in evaluating the efficacy of embolotherapy.

Applications of colour Doppler ultrasound in the diagnosis of chest diseases

Colour Doppler ultrasound (US) or colour Doppler imaging is a new imaging modality that can simultaneously display blood flow information and Doppler spectral analysis. This new technique provides an opportunity to assess pulmonary blood flow and perfusion non-invasively. Colour Doppler US has many potential applications in diseases of the chest. Colour Doppler imaging is useful in assisting the diagnosis of pulmonary arteriovenous malformation and pulmonary sequestration. The 'fluid colour sign' can be used to detect minimal effusion amenable to thoracentesis. Colour Doppler US can be used to assess the angiogenesis of a lung tumour and may be helpful in differentiating a malignant tumour from a benign one. Colour Doppler US can be used to guide a transthoracic needle biopsy and improve the safety of this invasive procedure. Colour Doppler US can demonstrate the vascular patterns and assess the regional haemodynamic changes of a pulmonary consolidation. The information of spectral wave analysis is helpful for understanding the haemodynamic changes of a pulmonary consolidation. Colour Doppler US is useful in assessing perfusion and reperfusion status of a pulmonary infarction. The recent advent of amplitude US angiography further improved the sensitivity of colour Doppler US in detecting blood flow signal without angle restriction. The potential application of these new techniques in chest diseases may need further exploration.

Thoracic sonography for diagnosis and intervention

Many physicians believe that ultrasound has limited usefulness in chest disease. Our clinical experiences and a review of the literature in preparation for this monograph have convinced us that sonography can be a very useful and versatile tool for thoracic diagnosis and intervention. Although there are some limitations caused by interposed ribs and air-containing lung, almost all of the compartments of the chest can be evaluated with ultrasound, which gives unique and clinically useful information. Ultrasound guidance for biopsy and drainage does take some time to learn, but we feel that the effort is very worthwhile. The same advantages ultrasound enjoys for other body regions make it a modality that will see increased use in the chest as well. We hope that this monograph will stimulate our colleagues to explore and expand upon the techniques described.

Thoraxsonography--Part II: Peripheral pulmonary consolidation

In many cases of pulmonary diseases extending up to the pleura, ultrasound (US) helps to identify the etiology of the lesion. There are several sonomorphological criteria to differentiate peripheral pulmonary consolidations. Pneumonic infiltration shows a hypoechoic inhomogeneous echo texture, with multiple air inlets and bronchoaerograms. Fluid bronchogram indicates an obstructive pneumonitis. Pulmonary infarctions are visible in different stages as triangular pleural-based lesions in most cases of pulmonary embolism. The diagnostic accuracy of chest sonography in pulmonary embolism was 85%-90%. US-guided transthoracic biopsy shows a diagnostic yield of > 90% in malignancies and 50%-83% of benign lesions. The overall complication rate is very low: 1%-2% hemoptysis, 2%-4% pneumothoraces and 1%-2% requiring chest tube drainage. Color Doppler US can demonstrate the vascular patterns and may help in the understanding of underlying pathophysiology. Sonographic examinations of the upper and central mediastinum provide good results in 90-95% of cases. Some anatomical limitations of transcutaneous US can be circumvented by endoluminal US.

Use of ultrasound-guided percutaneous needle biopsy in the diagnosis of mediastinal tumors

We herein report the usefulness of ultrasound-guided percutaneous needle biopsy for histological diagnosis in 18 patients with mediastinal tumors. Computed tomography revealed these tumors to be in contact with the chest wall. The preoperative diagnosis was thymoma in 7 patients, germinoma in 5, neurogenic tumor in 3, and "other" in 3. The most commonly encountered indication for an ultrasound-guided percutaneous needle biopsy was an anterior mediastinal lesion (78%; 14 of 18 patients). In 16 (89%) of the 18 patients, the biopsy diagnosis corresponded to the postoperative diagnosis. No complications were encountered in any of the patients. This new technique of ultrasound-guided percutaneous needle biopsy is both relatively simple and highly accurate and may thus be useful for outpatients. Preoperative ultrasound-guided percutaneous needle biopsy is thus considered to be a safe and reliable method for the histological diagnosis of mediastinal tumors, and a good alternative to traditional biopsy techniques such as mediastinoscopy or thoracotomy.

Transthoracic needle biopsy of thoracic tumours by a colour Doppler ultrasound puncture guiding device

BACKGROUND

Ultrasound guided transthoracic needle aspiration biopsy has recently been used to obtain specimens for histological diagnosis of pulmonary and mediastinal tumours. Conventional real time, grey scale puncture guiding devices cannot differentiate vascular structures, and clear visualisation of the needle shaft or tip within a desired target is not always possible. This study describes a new built-in colour Doppler ultrasound puncture guiding device and assesses the relative safety of transthoracic needle aspiration biopsy of thoracic tumours by grey scale or colour Doppler ultrasound guidance.

METHODS

Thirty patients with radiographic evidence of pulmonary (22 patients) or mediastinal tumours (eight patients) underwent ultrasonographic evaluation and transthoracic needle aspiration biopsy by using the colour Doppler ultrasound puncture guiding device (Aloka UST 5045P-3.5). These tumours were initially examined by grey scale ultrasound, and colour Doppler imaging was then used to evaluate the number of blood vessels surrounding and within the target tumour and the possibility of visualisation of the needle shaft or needle tip during the aspiration biopsy procedure.

RESULTS

The colour Doppler ultrasound guiding device was far superior to the grey scale device for identification of the number of vessels surrounding or within the target tumour (83% v 20%) and for visualisation of the needle shaft or needle tip (80% v 17%).

CONCLUSIONS

By using the colour Doppler ultrasound puncture device, vascular structures surrounding or within the target tumour can be verified. Visualisation of the needle shaft or tip is also better. Biopsy routes can be selected to avoid puncturing vessels. This approach should be particularly helpful for guiding biopsies of mediastinal tumours, where puncturing the heart or great vessels is a potential complication.

Fallibility of transthoracic needle biopsy of anterior mediastinal masses

Percutaneous transthoracic core needle biopsy has been advocated as a highly accurate technique for the diagnosis of anterior mediastinal masses. A patient is described with a large anterior mediastinal mass in whom the diagnosis of mediastinal carcinoid tumour was made by transthoracic core needle biopsy. At definitive surgical resection the tumour proved to be a B cell lymphoma. This case illustrates one of the important limitations of needle biopsy with its potential for sampling error.

Ultrasonically guided needle biopsy of anterior mediastinal masses: comparison of carcinomatous and non-carcinomatous masses

Thirty-three patients with anterior mediastinal masses underwent percutaneous ultrasonically guided needle biopsy (UGNB), including ultrasonically guided aspiration biopsy (UGAB) in all 33 patients and ultrasonically guided cutting biopsy (UGCB) in 13 patients. Using UGAB alone, the diagnostic rate of anterior mediastinal masses was 52% (17/33); if both the UGAB and UGCB methods were used, the diagnostic rate could achieve 79% (26/33). If the anterior mediastinal masses were divided into carcinomatous (n = 15) and non-carcinomatous (n = 18) groups, we found that the carcinomatous group was more easily diagnosed by UGAB than the non-carcinomatous group (87% vs 22%, p < 0.01) and UGCB was more valuable and helpful than UGAB in the diagnosis of non-carcinomatous mediastinal masses (75% vs 22%). One episode of injury to the aortic wall occurred after a UGCB. Our results show that carcinomatous mediastinal masses can be easily diagnosed by UGAB, and UGCB is often necessary in the diagnosis of non-carcinomatous mediastinal masses.

Direct determination of cryptococcal antigen in transthoracic needle aspirate for diagnosis of pulmonary cryptococcosis

Pulmonary cryptococcosis causes significant morbidity and mortality in immunocompromised patients. Definitive diagnosis of pulmonary cryptococcosis is usually difficult. The use of direct determination of cryptococcal antigen in transthoracic needle aspirate to diagnose pulmonary cryptococcosis was investigated. Over a 2-year period, we studied a total of 41 patients with respiratory symptoms and pulmonary infiltrates of unknown etiology who were suspected of having pulmonary cryptococcosis. Twenty-two patients were immunocompetent patients and 19 patients were immunocompromised. A diagnosis of pulmonary cryptococcosis was based on cytological examination, culture for Cryptococcus neoformans, histopathologic examination, and clinical response to antifungal therapy. All patients underwent chest ultrasound and ultrasound-guided percutaneous transthoracic needle aspiration to obtain specimens for cryptococcal antigen determination. The presence of cryptococcal antigen was determined by the latex agglutination system (CALAS; Meridian Diagnostics, Cincinnati, Ohio). An antigen titer equal to or greater than 1:8 was considered positive. The specimens were also sent for cytological examination, fungal culture, and/or histopathologic examination. A final diagnosis of pulmonary cryptococcosis was made in eight patients. Direct determinations of cryptococcal antigen in lung aspirate were positive in all eight patients with pulmonary cryptococcosis (100% sensitivity, 97% specificity, a positive predictive value of 89%, and negative value of 100%), and there was only one false-positive in noncryptococcosis patients. The diagnostic accuracy was 97.5%. Serum cryptococcal antigen was positive in only three patients with pulmonary cryptococcosis (sensitivity, 37.5%). This study showed that direct measurement of cryptococcal antigen in lung aspirate can be a rapid and useful test for diagnosis of pulmonary cryptococcosis.

Carcinoid tumours of the thymus

BACKGROUND

Carcinoid tumours of the thymus are rare. The clinical manifestations, radiographic findings, and cytological features of eight histopathologically verified thymic carcinoid tumours have been assessed.

METHODS

One hundred and sixty two patients of mean age 52 (range 31-68) years with malignant mediastinal tumours were reviewed retrospectively and eight cases of thymic carcinoid were identified. Four of the eight patients were diagnosed by percutaneous ultrasound guided fine needle aspiration biopsy via a parasternal approach.

RESULTS

Two patients had Cushing's syndrome at presentation and four had symptoms and signs secondary to mediastinal compression. Two were asymptomatic. Local extension of the tumour to pleura, pericardium, great vessels, phrenic nerve or regional lymph nodes, or both, were found in seven patients. Only one had the tumour confined to the thymus at diagnosis. Distant metastases were found in two patients, one to both lungs and the other in the iliac bone. Local recurrence or distant metastases developed 15-60 months after surgery in four of the five patients who underwent radical resection of the thymic tumour. Three patients died at 17 months, 34 months, and 10 years after diagnosis. The other five patients are alive at 9-51 months.

CONCLUSION

Thymic carcinoid is a slow growing tumour with a poor prognosis because of its tendency to local and distant spread. Cytological examination of samples obtained by ultrasound guided fine needle aspiration may provide a useful method for diagnosis in selected patients.