CT-guided transthoracic core-needle biopsy (CT-TTNB) is a minimally invasive procedure that plays a crucial role in diagnosing pulmonary nodules. With high diagnostic yield and low complication rates, CT-TTNB is favored over traditional surgical biopsies, providing accuracy in detecting both malignant and benign conditions. This literature review aims to present a comprehensive overview of CT-TTNB, focusing on its indications, procedural techniques, diagnostic yield, and safety considerations. Studies published between 2013 and 2024 were systematically reviewed from PubMed, Web of Science, Scopus, and Cochrane Library using the SANRA methodology. The results highlight that CT-TTNB has a diagnostic yield of 85-95% and sensitivity rates for detecting malignancies between 92 and 97%. Several factors, including nodule size, lesion depth, needle passes, and imaging techniques, influence diagnostic success. Complications such as pneumothorax and pulmonary hemorrhage were noted, with incidence rates varying from 12 to 45% for pneumothorax and 4 to 27% for hemorrhage. Preventative strategies and management algorithms are essential for minimizing and addressing these risks. In conclusion, CT-TTNB remains a reliable and effective method for diagnosing pulmonary nodules, particularly in peripheral lung lesions. Advancements such as PET/CT fusion imaging, AI-assisted biopsy planning, and robotic systems further enhance precision and safety. This review emphasizes the importance of careful patient selection and procedural planning to maximize outcomes while minimizing risks, ensuring that CT-TTNB continues to be an indispensable tool in pulmonary diagnostics.

Contrast-enhanced ultrasonography (CEUS) is a novel technology in ultrasound medicine that has gained widespread application in clinical practice. While CEUS offers various quantitative and qualitative parameters, it is limited by factors such as the single-color transient coverage of the contrast agent and its dependence on the operator, rendering it less suitable for detecting blood in organ lesions. Additionally, fluid dynamic perfusion remains unsatisfactory. Recently, arrival-time parametric imaging (At-PI) has emerged as a promising alternative; this technology not only uses color overlay to statically represent the dynamic perfusion of blood flow within lesions but also enhances visualization, minimizes operator variability, and provides insights into the vascular patterns of both benign and malignant lesions. At-PI has demonstrated numerous advantages and has been successfully applied to the liver, adrenal gland, breast, lymph nodes, prostate, and gastrointestinal tract, yielding encouraging preliminary results. This review synthesizes existing research findings, highlights significant parameters, examines the current global research landscape regarding this technology, and outlines the research directions pursued by scholars in the field. Furthermore, we offer a critical analysis and discussion of the limitations of these findings. The ultimate aim is to elucidate the role of At-PI in clinical diagnosis and treatment.

Primary pulmonary sarcoma and mesothelioma are rare malignancies. The review article discusses the appearance of these tumors in B-mode ultrasound (US), color Doppler ultrasound and contrast-enhanced ultrasound (CEUS). In particular, the article is intended to inspire the examination of thoracic wall tumors and pleural masses with the possibilities of ultrasonography and to obtain histologically evaluable material using US or CEUS-guided sampling.

To analyze the risk factors for pneumothorax after particle implantation in the treatment of advanced lung cancer and to construct and validate a nomogram prediction model.

A retrospective analysis was conducted on 148 patients who underwent 125I particle implantation for advanced lung cancer at the *** from December 2022 to December 2023. Potential risk factors were identified using univariate logistic regression analysis, followed by a multivariate logistic regression analysis to evaluate the predictive factors for pneumothorax. Interaction effects between variables were studied and incorporated into the model construction. ROC curves and nomograms were generated for visualization. Calibration analysis was performed, and the corresponding net benefit was calculated to adjust the predictive model.

Among the 148 patients, 58 (39.19%) experienced pneumothorax, with a mean age of 62.5 (55.25, 70) years. Multivariate analysis showed that the angle between the puncture needle and the pleura < 50° (P = 0.002, OR: 3.908, CI: 1.621-9.422), preoperative CT suggesting emphysema (P = 0.002, OR: 3.798, CI: 1.600-9.016), atelectasis (P = 0.009, OR: 3.156, CI: 1.331-7.481), and lesion located in the left lung fissure (P = 0.008, OR: 4.675, CI: 14.683) were independent risk factors for pneumothorax after particle implantation in the treatment of advanced lung cancer. Preoperative CT suggesting lesions in the left lung fissure or suggesting emphysema had a significant impact in the nomogram, with probabilities of pneumothorax occurrence at 40% and 38%, respectively. The predictive AUC for the above four risk factors for pneumothorax after particle implantation in the treatment of lung adenocarcinoma was 0.837 (95% CI: 0.767-0.908). When the Youden index was 0.59, the sensitivity was 85.56%, specificity was 74.13%, accuracy was 81.01%, positive predictive value was 83.69%, and negative predictive value was 76.78%.

The angle between the puncture needle and the pleura < 50°, preoperative CT suggesting emphysema, atelectasis, and lesion located in the left lung fissure are independent risk factors for pneumothorax after particle implantation in the treatment of advanced lung cancer. Preoperative planning of the puncture path should avoid lung bullae, interlobar fissures, areas of severe emphysema, and atelectasis.

Medical ultrasound has emerged as an indispensable tool within interventional pulmonology, revolutionizing diagnostic and procedural practices through its non-invasive nature and real-time visualization capabilities. By harnessing the principles of sound waves and employing a variety of transducer types, ultrasound facilitates enhanced accuracy and safety in procedures such as transthoracic needle aspiration and pleural effusion drainage, consequently leading to improved patient outcomes. Understanding the fundamentals of ultrasound physics is paramount for clinicians, as it forms the basis for interpreting imaging results and optimizing interventions. Thoracic ultrasound plays a pivotal role in diagnosing conditions like pleural effusions and pneumothorax, while also optimizing procedures such as thoracentesis and biopsy by providing precise guidance. Advanced ultrasound techniques, including endobronchial ultrasound, has transformed the evaluation and biopsy of lymph nodes, bolstered by innovative features like elastography, which contribute to increased procedural efficacy and patient safety. Peripheral ultrasound techniques, notably radial endobronchial ultrasound (rEBUS), have become essential for assessing pulmonary nodules and evaluating airway structures, offering clinicians valuable insights into disease localization and severity. Neck ultrasound serves as a crucial tool in guiding supraclavicular lymph node biopsy and percutaneous dilatational tracheostomy procedures, ensuring safe placement and minimizing associated complications. Ultrasound technology is suited for further advancement through the integration of artificial intelligence, miniaturization, and the development of portable devices. These advancements hold the promise of not only improving diagnostic accuracy but also enhancing the accessibility of ultrasound imaging in diverse healthcare settings, ultimately expanding its utility and impact on patient care. Additionally, the integration of enhanced techniques such as contrast-enhanced ultrasound and 3D imaging is anticipated to revolutionize personalized medicine by providing clinicians with a more comprehensive understanding of anatomical structures and pathological processes. The transformative potential of medical ultrasound in interventional pulmonology extends beyond mere technological advancements; it represents a paradigm shift in healthcare delivery, empowering clinicians with unprecedented capabilities to diagnose and treat pulmonary conditions with precision and efficacy. By leveraging the latest innovations in ultrasound technology, clinicians can navigate complex anatomical structures with confidence, leading to more informed decision-making and ultimately improving patient outcomes. Moreover, the portability and versatility of modern ultrasound devices enable their deployment in various clinical settings, from traditional hospital environments to remote or resource-limited areas, thereby bridging gaps in healthcare access and equity.

Suspicious tumors of the lung require specific staging, intraoperative detection, and histological confirmation. We performed an intrathoracic, intraoperative contrast-enhanced ultrasound (Io-CEUS) for characterization of lung cancer.

Retrospective analysis of prospectively collected data on the application of Io-CEUS in thoracic surgery for patients with operable lung cancer. Analysis of the preoperative chest CT scan and FDG-PET/CT findings regarding criteria of malignancy. Immediately before lung resection, the intrathoracic Io-CEUS was performed with a contrast-enabled T-probe (6-9 MHz-L3-9i-D) on a high-performance ultrasound machine (Loqic E9, GE). In addition to intraoperative B-mode, color-coded Doppler sonography (CCDS), or power Doppler (macrovascularization) of the lung tumor, contrast enhancement (Io-CEUS) was used after venous application of 2.4-5 mL sulfur hexafluoride (SonoVue, Bracco, Italy) for dynamic recording of microvascularization. The primary endpoint was the characterization of operable lung cancer with Io-CEUS. Secondly, the results of Io-CEUS were compared with the preoperative staging.

The study included 18 patients with operable lung cancer, who received Io-CEUS during minimally invasive thoracic surgery immediately prior to lung resection. In the chest CT scan, the mean size of the lung tumors was 2.54 cm (extension of 0.7-4.5 cm). The mean SUV in the FDG-PET/CT was 7.6 (1.2-16.9). All lung cancers were detected using B-mode and power Doppler confirmed macrovascularization (100%) of the tumors. In addition, Io-CEUS showed an early wash-in with marginal and mostly simultaneous central contrast enhancement.

The intrathoracic application of Io-CEUS demonstrated a peripheral and simultaneous central contrast enhancement in the early phase, which seems to be characteristic of lung cancer. In comparison to preoperative imaging, Io-CEUS was on par with the detection of malignancy and offers an additional tool for the intraoperative assessment of lung cancer before resection.

The incidence and mortality of lung cancer have increased annually. Accurate diagnosis can help improve therapeutic efficacy of interventions and prognosis. Percutaneous lung biopsy is a reliable method for the clinical diagnosis of lung cancer. Ultrasound-guided percutaneous lung biopsy technology has been widely promoted and applied in recent years.

To investigate the diagnostic value of contrast-enhanced ultrasound (CEUS)-guided percutaneous biopsy in peripheral pulmonary lesions.

We retrospectively collected data on 237 patients with peripheral thoracic focal lesions who underwent puncture biopsy at Wuxi People's Hospital. The patients were randomly divided into two groups: The CEUS-guided before lesion puncture group (contrast group) and conventional ultrasound-guided group (control group). Analyze the diagnostic efficacy of the puncture biopsy, impact of tumor size, and number of puncture needles and complications were analyzed and compared between the two groups.

Accurate pathological results were obtained for 92.83% (220/237) of peripheral lung lesions during the first biopsy, with an accuracy rate of 95.8% (113/118) in the contrast group and 89.9% (107/119) in the control group. The difference in the area under the curve (AUC) between the contrast and the control groups was not statistically significant (0.952 vs 0.902, respectively; P > 0.05). However, when the lesion diameter ≥ 5 cm, the diagnostic AUC of the contrast group was higher than that of the control group (0.952 vs 0.902, respectively; P < 0.05). In addition, the average number of puncture needles in the contrast group was lower than that in the control group (2.58 ± 0.53 vs 2.90 ± 0.56, respectively; P < 0.05).

CEUS guidance can enhance the efficiency of puncture biopsy of peripheral pulmonary lesions, especially for lesions with a diameter ≥ 5 cm. Therefore, CEUS guidance has high clinical diagnostic value in puncture biopsy of peripheral focal lung lesions.

Evaluation of patients with peripheral lung lesions and lesions of the chest wall and mediastinum is challenging. The nature of the lesion identified by imaging studies can be determined by histological evaluation of biopsies. An important place in this direction is the ever-increasing popularity among thoracic surgeons of the transthoracic biopsy with a cutting needle under ultrasound control (US-TTCNB).

Minimally invasive image-guided percutaneous core needle biopsy can obtain tissue samples for diagnosis of subpleural lung cancer, which is crucial for the correct management of lung lesions. Common complications of lung biopsy include pneumothorax, parenchymal haemorrhage and haemoptysis. The study aimed to determine the prevalence of ultrasound-guided biopsy among patients with lung lesions undergoing procedures in interventional radiology of a tertiary care centre.

A descriptive cross-sectional study was performed in the Department of Radiology and Imaging from 1 August 2018 to 30 September 2019 after obtaining ethical approval from the Institutional Review Committee. USG-guided biopsy of peripheral lung lesions was performed with an 18 gauge semiautomatic biopsy instrument and a 17 gauge coaxial needle. A convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval.

Among 188 biopsy of lung lesions, ultrasound-guided biopsies were performed in 28 (14.89%) (9.80-19.98, 95% Confidence Interval).

The prevalence of ultrasound guided biopsy among lung lesions is lower than other studies done in similar settings.

biopsy; interventional radiology; lung neoplasms; prevalence.

To explore the factors that influence sample adequacy and safety of ultrasound (US)-guided biopsy for peripheral pulmonary lesions (PPLs) with 16-G needles.

A total of 263 patients (150 men, 113 women; mean age, 60.7 ± 13 years) who received US-guided biopsy for PPLs with 16-G needles from July 2017 to March 2021 were included. Variables including patient demographics, lesion location, lesion size, proportion of lesion necrosis, presence of emphysema, presence of bullae around lesion, patient position, and number of needle passes were recorded. Univariate analysis and multivariable logistic regression analysis were performed to explore the factors that influence sample adequacy and safety.

Biopsy specimens were adequate for diagnosis in 242/263 (92%) cases. Multivariable logistic regression analysis revealed lesion size was significantly associated with sample adequacy (p=0.005, odds ratio [OR] = 1.039). The incidence of overall complication rate was 10.6% (28/263), including pneumothorax and haemorrhage, which occurred in 2.7% (7/263) and 9.9% (26/263) of patients, respectively. Patient position (lateral versus supine) was associated with overall complication rates (p=0.029, OR=3.407) and haemorrhage (p=0.013, OR=4.870). The presence of bullae around the lesion (p=0.026, OR=73.128) was an independent factor associated with pneumothorax.

US-guided percutaneous biopsy for PPLs with 16-G needles is effective and safe. Sample adequacy is significantly affected by lesion size. Patient lateral position is a risk factor for overall complication and haemorrhage. The presence of bullae around the lesion is a predictor of pneumothorax.

Percutaneous puncture is an important means of tumor diagnosis and treatment. At present, most puncture operations are still based on imaging location and clinical experience, and quantitative and accurate targeted puncture cannot be achieved. How to improve the accuracy of percutaneous tumor puncture, avoid errors to the greatest extent, reduce the occurrence of complications, and improve the overall clinical diagnosis and treatment quality and curative effect, are scientific problems worthy of further study.

In the present study, mathematical modeling was first used to construct the tumor puncture path, determine the needle entry angle, and define the relevant limited parameters and the substitution formula. Secondly, relevant parameters were extracted from CT and other imaging data and substituted into formulas, the deviation angle and puncture path were determined, and the personalized tumor puncture scheme was carried out. Third, targeted puncture was precisely implemented under the guidance of B-ultrasound. Compared with the traditional empirical puncture, our model improved the accuracy, decreased the puncture time, and reduced the pain of diagnosis and treatment for patients.

A tumor-targeted puncture model was established based on mathematical theory and imaging data. By extracting clinical data, such as tumor radius, projection distance of tumor center and projection distance from puncture point to body surface, the optimal puncture deviation angle was modeled and calculated and a personalized puncture scheme was established. Compared with the conventional method, our model markedly increased the puncture accuracy rate by ∼30%. The puncture number was decreased by ∼50% using our model. Furthermore, our model shortened the operation time by 20% to ease pain of patients and guarantee greater security for patients. Doctor satisfaction and patient discomfort scores were examined. Our model improved doctor satisfaction by ∼20% and reduced subjective discomfort of patients by ∼25%. These data revealed that the model could markedly improve the accuracy and efficiency of puncture, clinical efficacy and accuracy of tumor diagnosis. Additionally, the confidence of doctors in the operation was greatly enhanced and patient discomfort was greatly reduced.

The present study analyzed in detail how to find the best puncture path using a mathematical model. Based on the mathematical model of cognitive fusion puncture, combined with clinical personalized data and mathematical calculation analysis, accurate puncture was effectively realized. It not only greatly improved the effectiveness of puncture, but also ensured the safety of clinical patients and reduced injury, which means it may be worthy of clinical application.

This study aims to investigate the effect of ultrasound (US)-guided coaxial puncture needle in puncture biopsy of peripheral pulmonary masses. In this retrospective analysis, 157 patients who underwent US-guided percutaneous lung biopsy in our hospital were divided into a coaxial biopsy group and a conventional biopsy group (the control group) according to the puncture tools involved, with 73 and 84 patients, respectively. The average puncture time, number of sampling, sampling satisfaction rate, puncture success rate and complication rate between the 2 groups were compared and discussed in detail. One hundred fifty-seven patients underwent puncture biopsy, and 145 patients finally obtained definitive pathological results. The overall puncture success rate was 92.4% ([145/157]; with a puncture success rate of 97.3% [71/73] from the coaxial biopsy group and a puncture success rate of 88.1% [74/84] from the conventional biopsy group (P < .05). For peripheral pulmonary masses ≤3 cm, the average puncture time in the coaxial biopsy group was shorter than that in the conventional biopsy group, and the number of sampling, sampling satisfaction rate and puncture success rate were significantly higher than those in the conventional biopsy group (P < .05). There was no significant difference in the complication rate between the 2 groups (P > .05). For peripheral pulmonary masses >3 cm, the average puncture time in the coaxial biopsy group was still shorter than that in the conventional biopsy group (P < .05). The differences between the 2 groups in the number of sampling, satisfaction rate of the sampling, the success rate of puncture and the incidence of complications were not significant (P > .05). US guided coaxial puncture biopsy could save puncture time, increase the number of sampling, and improve the satisfaction rate of sampling and the success rate of puncture (especially for small lesions) by establishing a biopsy channel on the basis of the coaxial needle sheath. It provided reliable information for the diagnosis, differential diagnosis and individualized accurate treatment of lesions as well.

Though ultrasound-guided percutaneous lung needle biopsy (US-PLNB) is a first-line small biopsy method for peripheral lung lesions, quality of cellularity in specimens obtained via US-PLNB is uncertain. This study investigated the accuracy, sensitivity, and cellularity of US-PLNB. It examined the ability of contrast-enhanced ultrasound (CEUS) to improve the effectiveness of US-PLNB.

We retrospectively analyzed all data of patients with subpleural lung lesions who underwent US-PLNB. The cellularity of US-PLNB from malignant lesions included the tumor cell number and proportion. The definition of high-quality cellularity (HQC) was concurrently achieving a tumor cell number ≥400 and a proportion ≥20%. The sensitivity, the actual numbers of tumor cell number/proportion, and the rate of HQC were calculated and compared between the CEUS and non-enhanced US groups after propensity score matching (PSM) with subgroup analyses by lesion size (small lesion ≤30 mm and large lesion >30 mm).

A total of 345 patients undergoing 345 US-PLNBs were evaluated, with 3.7±1.1 of punctures on average. There were 201 malignant and 144 benign lesions with a mean size of 43.8±24.1 mm. Among the 201 malignant lesions, 124 cases underwent CEUS and 77 underwent non-enhanced US. The quantity of tumor cells, the proportion of tumor cells, and the rate of HQC in 201 cases of US-PLNB from malignant lesions were 2,862.1±2,288.0, 44.6%±24.5%, and 82.1% [95% confidence interval (CI): 76.6% to 87.1%], respectively. The quantity of tumor cells, the proportion of tumor cells, and rate of HQC were significantly higher in the CEUS group than that in the non-enhanced US group, both in the analysis of overall malignant lesions and in large malignant lesions (all P<0.05).

The US-PLNB has high sensitivity and thereby obtains HQC samples for subpleural lung malignant lesions. The CEUS helps improve the rate of HQC and tissue cellularity of lung malignancies.

Peripheral pulmonary lesions are encountered frequently in clinical practice. Accurate diagnosis of these lesions is of great importance for clinicians. Ultrasound-guided lung tissue puncture is a reliable method for diagnosing these lesions.

To investigate the application value of contrast-enhanced ultrasound (CEUS) combined with rapid on-site evaluation (ROSE) in the diagnosis of peripheral pulmonary focal lesions.

Eighty patients enrolled from July 2020 to June 2021 were divided into two groups: a conventional ultrasound group and a CEUS group. Both groups underwent diagnostic procedures guided by ROSE to improve the success rate of puncture sampling. The success rates and complications in both groups were compared. The results for lesion enhancement, time taken for the contrast agent to reach the lesions (AT) and lung tissues (L-AT), and the difference between these times (∆AT) were compared in the CEUS group.

The success rate of biopsy in the CEUS group was 97.62%, which was significantly higher than that in the conventional ultrasound group (84%; P < .05). Puncture complications did not occur in the CEUS group and occurred in 5.26% of the cases in the conventional ultrasound group, but the difference was not statistically significant (P > .05). A comparison of enhancement of benign lesions and malignant lesions in the CEUS group showed a statistically significant difference (P < .05). The difference between the AT and ∆AT of benign and malignant lesions was statistically significant (P <.05). The optimal threshold of ∆AT was 2.05 s.

CEUS combined with ROSE is a very important approach for biopsy in the diagnosis of peripheral pulmonary focal lesions. CEUS has definite clinical value in the diagnosis of benign and malignant lung lesions.

This article aims to explain the use of a variety of noninvasive of minimally invasive examinations to obtain reliable diagnostic clues. The choice of treatment methods and repair techniques for wound defects are also critical in terms of the prognosis. Here, we describe the case of a 53-year-old male patient who visited our dermatology clinic due to a red plaque on the inner side of his left nipple without any symptoms for more than 30 years. He was given dermoscopy, high-frequency ultrasound (HFUS), Color Doppler flow imaging (CDFI), and contrast-enhanced ultrasound (CEUS) examinations. Currently, there are no literatures on these auxiliary examinations for this disease. Dermoscopy revealed that there were abundant blood vessels on the periphery of the skin lesion with obvious dilation. HFUS revealed an inhomegeneous hypoechoic solid mass in the dermis with clear borders and irregular shape. CDFI indicated that there are abundant blood flow signals in the periphery and central of the tumor. CEUS showed a mixed inhomogeneous, grid-like high-enhancement pattern. Based on the above auxiliary findings, the possibility of malignant lesion was suspected. Therefore, the patient was given a pathological examination, which showed that many luminal structures of the dermis layer were embedded in the hyperplastic fibrous tissue. The atypical cells were not obvious but showed an infiltrating growth pattern. Immunohistochemistry showed positive reaction for cytokeratin 7 (CK7), epithelial membrane antigen (EMA), and carcinoembryonic antigen (CEA) and a weak positive results was obtained for S-100. There was also a negative result for CK20, gross cystic disease fluid protein 15 (GCDFP-15), and P63. As a result, the patient was diagnosed with "syringoid eccrine carcinoma." The treatment was surgical excision. Mohs microsurgery was combined with the looped, broad, and deep-buried suturing technique (LBD tension-reduced suturing technique). This technique directly sutures the wound instead of carrying out traditional skin grafting or flap transfer. The postoperative follow-up results were satisfactory as no obvious keloid formed on the wound during the follow-ups. In conclusion, ultrasound is greatly advantageous in tumor morphology and hemodynamics. It orients the therapeutic management and assesses the therapeutic efficacy and the tumoral prognosis. In surgical treatments, a less-traumatic operation should be selected to reduce the patient's pain.

Ultrasonography is a very good tool for guiding different interventional procedures in the chest. It is the ideal technique for managing conditions involving the pleural space, and it makes it possible to carry out procedures such as thoracocentesis, biopsies, or drainage. In the lungs, only lesions in contact with the costal pleura are accessible to ultrasound-guided interventions. In this type of lung lesions, ultrasound is as effective as computed tomography to guide interventional procedures, but the rate of complications and time required for the intervention are lower for ultrasound-guided procedures.

To evaluate diagnostic performance and safety of ultrasound-guided needle biopsy in the diagnosis of peripheral pulmonary nodules (PPLs) ≤ 2 cm, and the influence factors of sample adequacy and safety.

194 patients (99 men, 95 women; mean age, 56.2 ± 13.7 years) who received biopsy for PPLs ≤ 2 cm between January 2014 to January 2019 were included. Variables including patient demographics, lesion location, lesion size, presence of lesion necrosis, presence of emphysema on CT, patient position, biopsy needle size and number of needle passes were recorded. Univariate analysis and multivariate logistic regression analysis were performed to explore the influence factor of sample adequacy and safety.

Biopsy specimens were adequate for diagnosis in 161/194 (83%) cases; the diagnostic accuracy was 81.4% (158/194). The overall complication rate was 8.8% (17/194), including pneumothorax, hemoptysis and pleural effusion, which occurred in 2.1% (4/194), 5.2% (10/194), and 1.5% (3/194) of patients, respectively. The incidence of pneumothorax in the 16-gauge-needle group were significantly higher than that of the 18-gauge-needle group (5.6% vs 0%, P=0.018). Adequate sampling of 16-gauge and 18-gauge needles were achieved in 90.3%(65/72) and 78.7%(96/122) cases, respectively. Multivariate logistic regression analysis revealed needle size (16-gauge vs 18-gauge) was an independent influence factors of sample adequacy (P=0.015, odds ratio=3.419). A receiver operating characteristic curve was plotted and the area under the curve was 0.774.

US-guided percutaneous needle biopsy is a feasible and safe technique for small PPLs ≤ 2 cm. Needle size is an independent influence factor of sample adequacy and post-procedure pneumothorax. Sixteen-gauge needle has the advantage of achieving adequate sample for pathological analysis, though the risk of pneumothorax should be alerted.