Development and Prospective Validation of an Ultrasound Prediction Model for the Differential Diagnosis of Benign and Malignant Subpleural Pulmonary Lesions: A Large Ambispective Cohort Study

The Role of Contrast-Enhanced Ultrasound in the Differential Diagnosis of Malignant and Benign Subpleural Lung Lesions

Background: The application of transthoracic contrast-enhanced ultrasound (CEUS) to the study of peripheral lung lesions is still a topic of debate. The main objective of this review was to evaluate the diagnostic accuracy of CEUS in the diagnosis of malignant subpleural pulmonary consolidations and, therefore, differentiate them from benign ones. Methods: Papers published before December 2023 were detected through a search of PubMed, Cochrane library, and Embase. The pooled specificity and sensitivity, summary receiver operating characteristic (SROC) curve and diagnostic odds ratio (DOR) were used. Results: CEUS is characterized by a pooled sensitivity of 0.95 (95% CI: 0.93-0.97) and a pooled specificity of 0.93 (95% CI: 0.90-0.95) in differentiating benign and malignant subpleural lung diseases; the AUC of SROC was 0.97. Homogeneous CE was characterized by a pooled sensitivity of 0.43 (95% CI: 0.40-0.45) and the pooled specificity of 0.49 (95% CI: 0.46-0.52). Non-homogeneous CE displayed a pooled sensitivity of 0.57 (95% CI: 0.55-0.60) and a pooled specificity of 0.51 (95% CI: 0.48-0.54). The lack of CE displayed a pooled sensitivity of 0.01 (95% CI: 0.00-0.06) and a pooled specificity of 0.76 (95% CI: 0.64-0.85). Marked CE displayed a pooled sensitivity of 0.41 (95% CI: 0.37-0.44) and a pooled specificity of 0.54 (95% CI: 0.50-0.58). Non-marked CE displayed a pooled sensitivity of 0.59 (95% CI: 0.56-0.63) and a pooled specificity of 0.46 (95% CI: 0.42-0.50). The early AT displayed a pooled sensitivity of 0.04 (95% CI: 0.02-0.08) and a pooled specificity of 0.83 (95% CI: 0.77-0.87). The early wash out displayed a pooled sensitivity of 0.61 (95% CI: 0.48-0.72) and a pooled specificity of 0.98 (95% CI: 0.92-1.00). The delayed wash out displayed a pooled sensitivity of 0.15 (95% CI: 0.10-0.20) and a pooled specificity of 0.69 (95% CI: 0.62-0.75). Conclusions: CEUS is characterized by excellent diagnostic accuracy for the diagnosis of the malignancy of subpleural lung lesions. By separately analyzing the CEUS findings, the diagnostic accuracy values are considerably lower and not significant in some cases. The simultaneous evaluation of multiple CEUS features allows us to reach an excellent diagnostic accuracy. Non-homogeneous CE with early wash out are the most indicative features of malignancy of a lung lesion.

Diagnosis of benign and malignant peripheral lung lesions based on a feature model constructed by the random forest algorithm for grayscale and contrast-enhanced ultrasound

Rationale and objectives

To construct a predictive model for benign and malignant peripheral pulmonary lesions (PPLs) using a random forest algorithm based on grayscale ultrasound and ultrasound contrast, and to evaluate its diagnostic value.

Materials and methods

We selected 254 patients with PPLs detected using chest lung computed tomography between October 2021 and July 2023, including 161 malignant and 93 benign lesions. Relevant variables for judging benign and malignant PPLs were screened using logistic regression analysis. A model was constructed using the random forest algorithm, and the test set was verified. Correlations between these relevant variables and the diagnosis of benign and malignant PPLs were evaluated.

Results

Age, lesion shape, size, angle between the lesion border and chest wall, boundary clarity, edge regularity, air bronchogram, vascular signs, enhancement patterns, enhancement intensity, homogeneity of enhancement, number of non-enhancing regions, non-enhancing region type, arrival time (AT) of the lesion, lesion-lung AT difference, AT difference ratio, and time to peak were the relevant variables for judging benign and malignant PPLs. Consequently, a model and receiver operating characteristic curve were constructed with an AUC of 0.92 and an accuracy of 88.2%. The test set results showed that the model had good predictive ability. The index with the highest correlation for judging benign and malignant PPLs was the AT difference ratio. Other important factors were lesion size, patient age, and lesion morphology.

Conclusion

The random forest algorithm model constructed based on clinical data and ultrasound imaging features has clinical application value for predicting benign and malignant PPLs.

The Role of Contrast-Enhanced Ultrasound Plus Color Parametric Imaging in the Differential Diagnosis of Subpleural Pulmonary Lesions

OBJECTIVES

To distinguish benign and malignant subpleural pulmonary lesions (SPLs) with contrast-enhanced ultrasound (CEUS) and color parametric imaging (CPI), and evaluate the role of CEUS plus CPI in the differential diagnosis of pathological types of SPLs.

METHODS

One hundred and thirty-six patients underwent CEUS with a Logiq E9 XD Clear ultrasonic machine equipped with a 3.5- to 5.0-MHz C5-1 transducer in our center were enrolled in our study, including 27 cases of benign lesions and 109 cases of malignant lesions. The ultrasound contrast agent used in this study was SonoVue. CEUS images and CPI of all cases were reviewed and analyzed by the resident and staff radiologist groups separately.

RESULTS

With CEUS alone, by both the two groups, the main enhancement pattern of benign SPLs was arborization (P < .001), while centripetal enhancement pattern occurred more frequently in malignant SPLs (P < .001). With CEUS plus CPI, by both the two groups, the main enhancement pattern of benign SPLs was arborization (P < .001), while those of malignant SPLs were centripetal (P < .001) and eccentric (P < .05). The diagnosis performance of CEUS plus CPI was significantly higher than that of CEUS alone in both the resident (area under the curve [AUC] = 0.857 vs 0.677, P < .001) and staff (AUC = 0.866 vs 0.681, P < .001) groups. Moreover, CPI offered remarkable inter-consistency improvements in the enhancement pattern determination between the two groups.

CONCLUSION

The CEUS enhancement patterns would provide information of blood perfusion patterns in the differential diagnosis of benign and malignant SPLs. The diagnosis performance could be significantly improved by CEUS plus CPI compared with CEUS alone.

Diagnosis of malignant pleural disease: Ultrasound as "a detective probe"

BACKGROUND

Malignant pleural mesothelioma (MPM) is an invasive, aggressive pleural tumor with a predominantly local spread. The objective of this study was to assess thoracic ultrasound (TUS) as an imaging modality with high sensitivity for the identification of malignant pleural involvement and in order to guide pleural biopsies.

METHODS

In this retrospective single-center study between January 2018 and June 2022, 51 consecutive patients with impassable circumferential pleural thickening underwent TUS at the Thoracic Surgery Unit of the Vanvitelli University of Naples. Pleural biopsies were performed, and then large and multiple samples were sent to the pathological anatomy for histological examination.

RESULTS

In all patients who underwent ultrasound examination, we chose the optimal point of entry to perform pleural biopsies and selected the areas of greater thickening without pleural effusion. No patient had any complications. No drainage tubes were placed after the pleural biopsies and no pneumothorax was present during the following days of hospitalization. The patients were discharged on the second postoperative day.

CONCLUSION

With TUS the precise pleural thickening localization, local infiltration, mass extent, its nature (solid, cystic or complex) and ultrasound features can be easily defined. Furthermore, ultrasound is more economical than computed tomography and avoids the risks associated with radiation. Thoracic ultrasound is an important component of the diagnostic procedure in detecting a safe entry site for biopsies of MPMs.

Utility of high-frequency B-mode and contrast-enhanced ultrasound for the differential diagnosis of benign and malignant pleural diseases: a prospective study

BACKGROUND

Pleural disease is a prevalent condition. As precision therapy advances, noninvasive imaging modalities play even more important roles in the evaluation of pleural diseases. This study investigated the diagnostic capabilities of high-frequency B-mode ultrasound (US) and contrast-enhanced US (CEUS) in terms of differentiating between benign and malignant pleural diseases.

METHODS

Patients with unexplained thickened pleurae were prospectively analyzed via transthoracic US. High-frequency B-mode US was used to derive the pleural thickness, morphology, and echogenicity. We analyzed the high-frequency CEUS data including the enhancement mode and time intensity curve (TIC). The cause of pleural thickening was confirmed by pleural biopsy and follow-up after the biopsy. We analyzed the differences in various ultrasonic features between the malignant and benign groups. Moreover, we plotted receiver operator curves (ROCs) and obtained the area under the curves, sensitivities, and specificities of all significant continuous variables. Multivariate logistic regression was used to assess the combined usefulness of multiple US indicators in terms of predicting malignant pleurae.

RESULTS

Thirty malignant and twenty benign thickened pleurae were finally diagnosed via pleural biopsy and at least six months of follow-up. The pleural morphology and enhancement modes significantly differed between the two groups (all P<0.05). The thickness derived from B-mode US and CEUS were significantly thicker in the malignant group (both P<0.05). Arrival time (AT) and the time to peak (TTP) of TIC were significantly shorter in the malignant group, whereas peak intensity and the area under the TIC were significantly higher in the malignant group (all P<0.05). The area under the ROC for pleural thickness derived from B-mode US was 0.819; pleural thickness derived from CEUS was 0.848; AT was 0.804; TTP was 0.750; peak intensity was 0.745; the area under the TIC was 0.743; and the combined various B-mode and CEUS parameter was 0.975.

CONCLUSIONS

Pleural thickness, morphology, enhancement mode, and the TIC of high-frequency US aided the differentiation of benign from malignant pleural diseases. Combined analysis of US indicators further improved the diagnostic capability.

Can Ultrasound and Contrast-Enhanced Ultrasound Help Differentiate between Subpleural Focal Organizing Pneumonia and Primary Lung Malignancy?

Background: Subpleural focal organizing pneumonia (FOP) and primary lung malignancy (PLM) are usually confused. The aim of this study was to explore the value of ultrasound (US) and contrast-enhanced ultrasound (CEUS) in the differential diagnosis of FOP and PLM. Methods: A total of 23 patients (mean age: 64.57 ± 11.86 years) with FOP and 100 (mean age: 66.29 ± 11.05 years) with subpleural lesions diagnosed as PLM, confirmed by pathological diagnosis and clinical follow-up, were retrospectively enrolled. The largest lesion diameter, angle between the lesion border and thoracic wall, air bronchial sign, internal blood supply, blood supply form, and pleural effusion examined using conventional US were retrospectively analyzed. The indicators of CEUS included the arrival time of contrast agent in the lesion, lesion−lung arrival time difference, degree of enhancement, distribution uniformity of contrast medium, presence of non-enhancing region, and arterial filling mode in the lesion. A p < 0.05 was considered statistically significant. Results: Presence of air bronchial sign (odds ratio [OR] = 6.18, p = 0.025), acute angle between the lesion border and thoracic wall (OR = 7.124, p = 0.033), and homogeneous enhancement (OR = 35.26, p = 0.01) showed predictive value for the diagnosis of FOP. According to the results of the logistic regression analysis, the area under the receiver operating curve of the above features combined was 0.960, and the sensitivity and specificity were 95.0% and 82.6%, respectively. Conclusions: US combined with CEUS has the potential to differentiate between FOP and PLM.

Application value of contrast-enhanced ultrasound in the diagnosis of peripheral pulmonary focal lesions

INTRODUCTION

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.

OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Application of neck ultrasound in the diagnosis of sarcoidosis

Objective

To explore the significance of neck ultrasound (NUS) combined with contrast-enhanced ultrasound (CEUS) in the diagnosis of sarcoidosis.

Methods

88 patients with evidence of intrathoracic lymphadenopathy and suspected sarcoidosis with enlarged cervical lymph nodes underwent NUS, CEUS, fine-needle aspiration and core needle biopsy when technically feasible were retrospectively analyzed in this study. Seven characteristics such as enhanced mode (EM), resolution time, color Doppler flow imaging (CDFI), fading time, peaking state-uniformity, strengthen the area and symmetry were considered to perform the logistic regression model.

Results

Of 88 patients included in this study, sarcoidosis was accounted in 20 cases, tuberculosis in 23 cases, malignancy in 22 cases and inflammatory lymph node in 23 cases. There were statistically significant differences in symmetry, lymphatic hilum, homogeneity, CDFI pattern and elasticity score between the sarcoidosis and non-sarcoidosis groups via NUS. Similarly, we also acknowledged a statistically significant differences in EM, homogeneity, presence or absence of necrosis between the sarcoidosis and non-sarcoidosis groups via CEUS to further group the non-sarcoidosis into tuberculosis, malignancy or inflammatory disorder. The percentage correction of prediction was 90% (18/20).

Conclusion

NUS combined with CEUS has characteristic features in sarcoidosis with cervical lymph node involvement, which is helpful for its diagnosis and differential diagnosis. The binary classification model of NUS combined with CEUS features can help differentiate sarcoidosis from non-sarcoidosis groups.