Traumatic pneumothorax detection with thoracic US: correlation with chest radiography and CT--initial experience

PURPOSE: To prospectively compare the accuracy of ultrasonography (US) with that of supine chest radiography in the detection of traumatic pneumothoraces, with computed tomography (CT) as the reference standard. MATERIALS AND METHODS: Thoracic US, supine chest radiography, and CT were performed to assess for pneumothorax in 27 patients who sustained blunt thoracic trauma. US and radiographic findings were compared with CT findings, the reference standard, for pneumothorax detection. For the purpose of this study, the sonographers were blinded to the radiographic and CT findings. RESULTS: Eleven of 27 patients had pneumothorax at CT. All 11 of these pneumothoraces were detected at US, and four were seen at supine chest radiography. In the one false-positive US case, the patient was shown to have substantial bullous emphysema at CT. Sensitivity and negative predictive value of US were 100% (11 of 11 and 15 of 15 patients, respectively), specificity was 94% (15 of 16 patients), and positive predictive value was 92% (11 of 12 patients). Chest radiography had 36% (four of 11 patients) sensitivity, 100% (16 of 16 patients) specificity, a 100% (four of four patients) positive predictive value, and a 70% (16 of 23 patients) negative predictive value. CONCLUSION: In this study, US was more sensitive than supine chest radiography and as sensitive as CT in the detection of traumatic pneumothoraces.     

Pneumothorax post CT-guided lung biopsy: a comparison between detection on chest radiographs and CT

Pneumothorax is reported to be a more common complication of lung biopsy performed under computed tomography (CT) than under fluoroscopic guidance. This may simply reflect the greater sensitivity of CT over chest radiographs (CXRs) in the detection of small pneumothoraces. This study aimed to determine the incidence of pneumothorax detected by CXR and by CT after CT-guided biopsy of non-pleurally based pulmonary masses, and to compare these incidences with previous reports in the literature of pneumothorax incidence post fluoroscopic biopsy. 88 consecutive CT-guided lung biopsies of masses not abutting the pleural surface were included. Immediate post-biopsy CT images, and 1 and 4 h CXRs were assessed independently by two observers for the presence and size of pneumothorax. 72 biopsies were fine needle aspirations (FNAs) performed with 22 G spinal needles only, seven were cutting needle biopsies (CNBs) performed with 18 G cutting needles only, and nine were both. 37 patients (42%) developed a pneumothorax. 35 were detected on CT (40%) and 22 on CXR (25%). None required tube drainage. Of the patients in whom CT demonstrated a pneumothorax, the average depth of this was significantly greater for those in whom CXR also detected a pneumothorax compared with those in whom CXR was negative (7.3 mm versus 3.4 mm, p < 0.05). The incidence of pneumothorax detected on CXR post CT-guided biopsy is similar to the reported incidence post fluoroscopic biopsy.     

Value of ultrasound in diagnosis of pneumothorax: a prospective study

Transthoracic ultrasound (US) 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 role of chest US in the diagnosis of pneumothorax has been established, but comparison with lung computed tomography (CT) scanning has not yet been completely performed. The purpose of this study is to prospectively compare the accuracy of US with that of chest radiography in the detection of pneumothorax, with CT as the reference standard. One hundred ninety-seven patients who were evaluated by spiral chest CT scan for various clinical indications were prospectively evaluated. Ultrasonography was performed by a radiologist, blinded to the chest CT findings. Sensitivity, specificity, and accuracy of ultrasound in the detection of pneumothorax were then compared with chest CT scan. CT scan showed pneumothorax in 92 patients. Sonography and plain X-ray of the chest revealed 74 and 56 cases of pneumothorax, respectively. Statistical analysis disclosed the US to be 80.4 % sensitive and 89 % specific in the detection of pneumothorax with an overall accuracy of 85 %. In this study, US was more sensitive than chest radiography in the detection of pneumothorax. The results of this study suggest that thoracic US, when performed by trained individuals, can be helpful for the detection of pneumothorax.     

Image-guided pleural biopsy: diagnostic yield and complications

BACKGROUND: Pleural biopsy and cytology are standard procedures for the investigation of pleural disease. Recent medical literature has suggested that image-guided pleural biopsy shows improved sensitivity for the diagnosis of pleural malignancy, when compared with the more commonly performed reverse bevel needle biopsy such as Abrams' needle. In our centre there has been an increasing trend towards performing image-guided pleural biopsies, and to our knowledge there is no large published series documenting the complication rate and diagnostic yield. METHODS: The radiology and pathology databases were searched for all image-guided [computed tomography (CT) and ultrasound (US)] pleural biopsies from January 2001 to December 2004. All imaging and histology were reviewed, and final diagnostic information about patients was obtained from the respiratory multidisciplinary team database and patient notes. A record was made of complications following biopsy, presence of pleura in the biopsy, and adequacy of tissue for histological diagnosis. RESULTS: A total of 82 patients underwent 85 image-guided pleural biopsies over a 4-year period. 80 cases were performed under CT and five under US guidance. The rate of new pneumothorax detected by chest radiography was 4.7%. No patient required a chest drain or blood transfusion to treat complications. In 10 (12%) cases, there was inadequate tissue to reach a confident histological diagnosis and in eight (9%) of these, no pleura was present. Assuming all suspicious and inadequate biopsies are treated as benign, which is the worst case scenario, image-guided pleural biopsy has a sensitivity and specificity of 76% and 100%, respectively, for the diagnosis of malignant disease. CONCLUSIONS: Image-guided pleural biopsy is a safe procedure with few associated complications and has a higher sensitivity than previously published series for reverse cutting needle biopsy in the diagnosis of malignant pleural disease.     

Bullous lesions detected by computed tomography

An analysis was made of bullous emphysema detected by plain chest radiography and computed tomography (CT). Bullous lesions were detected in 43 of 214 patients who had thoracic CT as a further assessment of their pulmonary, pleural, and mediastinal abnormalities. Plain chest radiography failed to detect the bullous lesions in 17 (39.5%) out of the 43 patients. Bullous lesions unrecognizable on plain radiographs ranged from 1.0 to 2.0 cm in size, were few in number, and were situated on the mediastinal side of the lung in many patients. CT is a sensitive method for detecting bullous lesions. Therefore, we consider it necessary to perform CT when needle biopsy for a previously known pulmonary lesion is taken into account, because knowledge of coexisting bullous lesions may be useful in preventing the occurrence of severe pneumothorax as complication.     

320例胸部病变CT引导经皮穿刺活检总结

目的：评价CT引导经皮胸部穿刺术的诊断价值和并发症。材料和方法：收集资料完整的320例CT引导胸部穿刺活检病例作回顾性分析。肺部病变267例,纵隔病变30例,胸壁和胸膜病变23例。统计敏感性、特异性、准确性和并发症,并分析其影响因素。结果：191例穿刺确诊为恶性肿瘤。穿刺未发现癌细胞者129例,后经手术和随访证实其中属特征性阴性结果者58例,非特征性阴性结果46例,假阴性25例。未见假阳性,阳性预测值为100％（191／191）,敏感性为88．4％（191／216）,特异性为80．6％（104／129）,准确性为92．2％（295／320）,假阴性率为19．4％（25／129）。29例发生气胸,占9．1％（29／320）,但仅1．6％（5／320）需要引流处理。肺出血12例,咯血12例,纵隔血肿8例,均为少量,不需处理。结论：CT引导经皮胸部穿刺是敏感性高和安全的定性诊断方法,降低假阴性是进一步提高准确性的关键。     

Ultrasound guided puncture of pleural fluid collections and superficial thoracic masses

Fluoroscopically guided percutaneous aspiration biopsy of pulmonary masses and conventional needle thoracocentesis for the diagnostic evaluation and treatment of pleural fluid collections, are well established procedures. In the abdomen, ultrasonographic guidance is a widely accepted method, but is usually considered to be of limited values in the chest because of overlying ribs and aerated lung tissue. Nevertheless, ultrasound is well suited as a guiding modality for both aspiration of pleural fluid collections and biopsy of pleural thoracic masses. We describe and discuss the method on the basis of 55 punctures in 46 patients, in most of whom previous attempts guided by radiography and clinical examination had failed. Diagnostic/therapeutic results were obtained in all cases but one. The only complication was minor pneumothorax in two patients.     

Transthoracic needle biopsy of lung masses: a survey of techniques

AIM: In order to assess the range and everyday use of the various techniques for percutaneous transthoracic needle biopsy of lung masses in the USA and Canada, we surveyed thoracic radiologists in academic and community practice on their standard approach to the procedure. MATERIALS AND METHODS: The 300 questionnaires that were mailed to members of the Society of Thoracic Radiology throughout the USA and Canada contained specific questions on their approach to a transthoracic needle biopsy of a routine case of a 3cm lung mass located in the right lower lobe 1cm from the pleural surface. RESULTS: A total of 140 (47%) members responded. Of the 139 responders who performed lung biopsies, 103 (74%) were located at a teaching centre affiliated to a university or medical school, and 36 (26%) were community-based radiologists. In total 97 (70%) replied that they would perform the procedure under CT guidance, 31 (22%) under either CT or fluoroscopy guidance, and 11 (8%) only under fluoroscopy. Fine-needle aspiration was the procedure of choice for the given case by 101 (73%) responders, whereas 20 (14%) preferred doing core biopsy, and 18 (13%) chose both techniques. On-site cytology confirmation for obtaining diagnostic material was available to 101 (73%) responders. Before performing the procedure, 107 (77%) verified coagulation tests whereas 32 (23%) did not. Follow-up imaging for pneumothorax assessment was not routinely performed by 15 (11%) responders. CONCLUSION: The majority of radiologists performed percutaneous transthoracic needle biopsy of a lung mass under CT guidance, by fine-needle aspiration, using repeated pleural puncture technique, and with a cytologist on site. A significant minority did not obtain coagulation screening before the procedure, and a small minority did not routinely assess for pneumothorax by late chest radiography.     

弹簧芯状活检针在CT引导经皮肺穿刺活检中的应用

目的：探讨CT引导下使用弹簧芯状活检针行比皮肺穿刺活检的诊断准确性和并发症发生率。方法：38例使用弹簧芯状活检针的经皮肺穿刺活检。CT扫描确定并引导穿刺途径,达预定位置取材。结果：35例有明显的病理诊断,诊断准确性92％,恶性肿瘤和良性病变的诊断准确性分别为97％和100％。活后并发气胸4例,咯血1例,结论：CT引导下使用弹簧芯状活检针行经皮肺穿刺活检的气胸发生率与细针抽吸相近,使弹簧芯状活检针行CT引导下肺穿刺活检可以提高诊断的准确性。     

Transthoracic needle biopsy of the lung: results of early discharge in 506 outpatients

PURPOSE: To determine the safety of early discharge (30 minutes) after transthoracic needle biopsy (TTNB) of the lung. MATERIALS AND METHODS: In a prospective study of 506 consecutive outpatients who underwent TTNB of the lung, 440 patients underwent fine-needle aspiration biopsy (FNAB) only, and 66 underwent FNAB and core biopsy. Patients were discharged after 30-minute postbiopsy chest radiography if there was no pneumothorax. Patients were discharged after 60-minute chest radiography if they had a stable asymptomatic pneumothorax. These patients were followed up 1 day and/or 1 week after biopsy to identify delayed complications. Patients with a symptomatic or enlarging pneumothorax were treated with an 8-F pigtail catheter attached to a Heimlich valve, discharged, and followed up 24 hours later for chest tube removal. RESULTS: The pneumothorax rate was 22.9% (116 patients). Eighty-one patients (16.0%) had an asymptomatic pneumothorax, and 33 (6.5%) had a pigtail catheter in place. Seven (1.4%) patients developed a symptomatic pneumothorax after discharge; two of them (0.4%) underwent large-bore chest tube insertion. The other five (1.0%) underwent delayed pigtail catheter insertion. There were no deaths or other major complications. CONCLUSION: Early discharge after outpatient TTNB of the lung is associated with little morbidity and no mortality.     

CT detection of occult pneumothorax in head trauma

A prospective evaluation for occult pneumothorax was performed in 25 consecutive patients with serious head trauma by combining a limited chest CT examination with the emergency head CT examination. Of 21 pneumothoraces present in 15 patients, 11 (52%) were found only by chest CT and were not identified clinically or by supine chest radiograph. Because of pending therapeutic measures, chest tubes were placed in nine of the 11 occult pneumothoraces, regardless of the volume. Chest CT proved itself as the most sensitive method for detection of occult pneumothorax, permitting early chest tube placement to prevent transition to a tension pneumothorax during subsequent mechanical ventilation or emergency surgery under general anesthesia.     

在ICU应用超声诊断危重病人气胸的临床评价

目的探讨在ICU应用床旁超声诊断危重病人气胸的临床效果。方法2005年9月—2006年7月ICU收治95例危重病人,进行床旁胸部超声检查,以“肺滑行”和“彗尾”征消失诊断气胸。在超声检查前后3h内行胸部CT和床旁X片检查,以CT结果为“标准”比较超声和X片诊断气胸的价值。结果95例危重病人中,CT确诊气胸24例27侧,超声诊断21例23侧,X片诊断5例5侧,相应的诊断敏感性、特异性、阳性预测值、阴性预测值和准确度分别为85.1%对18.5%(P<0.001),98.8%对100%(P=0.489),92.0%对100%(P=1.0),97.6%对88.1%(P=0.002)和96.8%对88.4%(P=0.009)。超声与CT诊断气胸的一致性高于X片。结论在ICU应用超声检查诊断气胸具有较高的敏感性和特异性,为危重病人气胸的诊断提供了简单、快速而安全有效的手段。     

Image-guided coaxial fine needle aspiration biopsy with a side-exiting guide

PURPOSE: The aim of this study was to evaluate the diagnostic accuracy and complication rates of a side-exiting coaxial needle system for fine needle aspiration (FNA) biopsies. METHOD: Between 1995 and 1998, 127 nonconsecutive biopsies were performed on 122 patients (74 males, 48 females). CT guidance was used in 111, ultrasound guidance was used in 14, and both were used in 2 biopsies. Patient history, biopsy site, needle performance, complications, and cytology results were recorded. RESULTS: Diagnostic rate and accuracy were 92.9 and 99.2%, respectively. There were minor complications from 14 biopsies, and all of them arose from chest biopsies: pneumothorax in 13 of 47 and hemoptysis in 1 of 47. There were no major complications. CONCLUSION: The side-exiting coaxial needle system is a safe and effective alternative to the conventional end-exiting coaxial needle system for performance of image-guided FNA biopsies.     

Ultrasound diagnosis of pneumothorax

PURPOSE: The purpose of this study was to show the effectiveness of ultrasound (US) in the evaluation of pneumothorax by comparison with X-rays and computed tomography (CT). MATERIALS AND METHODS: A series of 184 patients (130 men and 54 women), aged 26 to 82 years, underwent chest US after percutaneous needle biopsy. US findings were compared with CT postbiopsy selective slices and to X-rays. RESULTS: Pneumothorax was identified in 46 patients (25%) by CT, in 44 by US, with no false positives, and in 19 by X-rays. US sensitivity was 95.65%, specificity 100% and diagnostic effectiveness 98.91%. CONCLUSIONS: Chest US was found to be a valuable diagnostic tool in pneumothorax diagnosis, with diagnostic effectiveness well beyond X-rays and similar to CT.     

Detection and diagnosis of the primary tumor in lung cancer

The role of radiology in the initial detection and diagnosis of primary lung cancer is well established. Recent advances in the detection of lung cancer stem from research into the visual search patterns used by a radiologist when reading a chest radiograph. Computer feedback of "visual-dwell" positions can lead to an increase in true-positive detection of lung nodules and decrease the false-positive rate. Plain film radiography and CT continue as the mainstays for the characterization of lung nodules. New studies involving the use of conventional tomography to detect contrast enhancement of malignant lesions and the use of axial multiplanar reconstruction CT to demonstrate involvement of pulmonary veins by malignant lesions are detailed. Transbronchial and percutaneous transthoracic biopsy techniques are widely used to diagnose the nature of solitary pulmonary nodules. The dependent positioning of the biopsy site has been shown to decrease both the pneumothorax rate and the frequency of chest drain insertion, whereas the blood patch technique was shown not to affect the pneumothorax rate at all.     

CT-guided cutting needle biopsy of lung lesions--safety and efficacy of an out-patient service

AIM: To determine the safety and efficacy of CT-guided cutting needle biopsy of lung lesions as an out-patient procedure. MATERIALS AND METHODS:A total of 185 consecutive biopsies were performed under CT guidance on 183 patients between January 1991 and December 1998 using 20-gauge (n= 33), 18-gauge (n= 151) or 14-gauge (n= 1) core biopsy needles. A chest radiograph was taken after observation in the Radiology department for 1 h and asymptomatic patients were discharged. RESULTS: The histology was malignant in 150 biopsies (81. 1%) and benign in 23 (12.4%) with 12 false-negative results (6.5%); there were no false-positive results. The sensitivity was 92.6%; specificity 100%; negative predictive value 65.7%; and overall accuracy 93.5%. Pneumothoraces occurred in 48 patients (25.9%); one required aspiration only and four required insertion of an intercostal drain. One patient developed a pneumothorax after discharge. Small haemoptyses occurred in 13 patients without pneumothorax (7.0%), one of whom was admitted. In-patient treatment was required in 10 patients (5.4%). CONCLUSION: Computed tomography-guided cutting needle biopsy of pulmonary lesions is a safe technique with a diagnostic accuracy and complication rate comparable to reported figures for fine needle aspiration biopsy. It can be safely performed on an out-patient basis.     

Percutaneous lung biopsies: a survey of UK practice based on 5444 biopsies

Percutaneous transthoracic lung biopsies are commonly performed for the investigation of lung masses. We describe current practice and complication rates in the UK. A postal questionnaire was sent to all centres in the British Thoracic Society directory. 157 replies (61% response rate) were received, providing data on 5444 biopsies. Mean number of biopsies performed per annum was 30.5 per centre; 8% of centres did not perform biopsies, 36% performed <25 biopsies per annum, 34% <50, 16% <100 and 6% >100. Consultant radiologists perform 91% of biopsies. Written consent was obtained at all centres. The operator obtained consent at 50% of centres. Written information for patients was provided at 35 (24%) centres. Biopsies are performed on a day case basis at 103 (71%) centres. Prior to biopsy the following were obtained routinely: CT scan (73% of centres), platelet count (73%), full clotting screen (70%), lung function (55%). Complications included pneumothorax (20.5% of biopsies), pneumothorax requiring chest drain (3.1%), haemoptysis (5.3%) and death (0.15%). The timing of post-procedure chest radiography was variable. Those centres that performed predominantly cutting needle biopsies had similar pneumothorax rates to centres performing mainly fine needle biopsies (18.9% vs 18.3%). There is great variation in practice throughout the UK. Most procedures are performed on a daycase basis. Small pneumothoraces are common but infrequently require treatment. National guidelines are needed to ensure consistency of standards.     

Efficacy of manual aspiration immediately after complicated pneumothorax in CT-guided lung biopsy

PURPOSE: The goal of this study was to evaluate the efficacy of simple aspiration of air from the pleural space to prevent increased pneumothorax and avoid chest tube placement in cases of pneumothorax after computed tomography (CT)-guided lung biopsy. MATERIALS AND METHODS: This retrospective study was based on experience with 283 consecutive percutaneous needle lung biopsies with real-time CT fluoroscopic guidance. While patients were on the CT scanner table, percutaneous manual aspiration was performed in all those with moderate or large pneumothorax demonstrated on postbiopsy chest CT images regardless of symptoms. The authors evaluated the frequency of biopsy-induced pneumothorax, management of each such case, and factors that influenced the incidence of worsening pneumothorax that required chest tube placement despite manual aspiration. RESULTS: Of the 104 (36.7%) pneumothoraces occurring after 283 biopsy procedures, 52 were treated with manual aspiration immediately after biopsy. In 95 of the 104 pneumothoraces (91.3%), the pneumothorax had resolved completely on follow-up chest radiographs without chest tube placement. Only nine patients (3.2% of the entire series; 8.7% of those who developed pneumothorax) required chest tube placement. Requirement of chest tube insertion significantly increased parallel to the increased volume of aspirated air. The optimal cutoff level of aspirated air on which to base a decision to abandon manual aspiration alone and resort to chest tube placement was 543 mL. CONCLUSION: Percutaneous manual aspiration of biopsy-induced pneumothorax performed immediately after biopsy may prevent progressive pneumothorax and eliminate the need for chest tube placement. However, in cases in which the amount of aspirated air is large (such as more than 543 mL in this study), the possibility of required chest tube placement increases.     

Factors influencing pneumothorax rate at lung biopsy: are dwell time and angle of pleural puncture contributing factors?

PURPOSE: To study factors that may influence pneumothorax and chest tube placement rate, especially needle dwell time and pleural puncture angle. MATERIALS AND METHODS: In 159 patients, 160 coaxial computed tomography (CT)-guided lung biopsies were performed. Dwell time, the time between pleural puncture and needle removal, was calculated. The smallest angle of the needle with the pleura ("needle-pleural angle") was measured. These and other variables were correlated with pneumothorax and chest tube rates. RESULTS: One hundred fifty biopsies were included. There were 58 (39%) pneumothoraces (14 noted only at CT), with eight (5%) biopsies resulting in chest tube placement. Longer dwell times (mean, 29 minutes; range, 12-66 minutes) did not correlate with pneumothoraces (P =.81). Smaller needle-pleural angles (< 80 degrees) [corrected], decreased forced expiratory volume in 1 second to vital capacity ratio (<50%), lateral pleural puncture, and lesions along fissures were associated with higher [corrected] pneumothorax rates (P <.05). Emphysema along the needle path, pulmonary function tests showing ventilatory obstruction, and lesions along fissures predisposed patients to chest tube placement (P <.05). Pleural thickening and prior surgery were associated with lower pneumothorax rates (P <.05). CONCLUSION: Longer dwell times do not correlate with pneumothorax and should not influence the decision to obtain more biopsy samples. A shallow pleural puncture angle may increase the pneumothorax rate.     

Value of high-resolution ultrasound in detecting a pneumothorax

This study was designed to compare the detectability of high-resolution ultrasound (HRUS) and bedside chest radiography (CR) for a pneumothorax. During the last 14 months, 97 consecutive patients who were admitted to our institute to undergo a transthoracic needle aspiration and biopsy (TNAB) of the lung were included. Both HRUS and CR were performed immediately after the TNAB procedure. The HRUS images were saved in sequence using the cine-review mode and displayed as an animation on a workstation. Four radiologists independently analyzed both HRUS images and a soft copy of the CR on a diagnostic monitor and identified the pneumothorax. With CT as the reference standard, statistical parameters were calculated. From 97 patients, 35 pneumothorax cases were found on CT after the TNAB. The sensitivities in detecting the pneumothorax were 80 and 47% in HRUS and CR, respectively. The specificities were 94 and 94%. The diagnostic accuracies were 89 and 77%. The inter-observer agreement was excellent (=0.85) in the HRUS images and moderate (=0.49) in the CR. The results of this study suggest that HRUS is a more sensitive and confident method for diagnosing a pneumothorax when compared to bedside chest radiography.