Virtual bronchoscopic navigation without fluoroscopy guidance for peripheral pulmonary lesions in inexperienced pulmonologist

Objective:Fluoroscopy guidance is generally required for endobronchial ultrasonography with guide sheath(EBUS-GS)in peripheral pulmonary lesions(PPLs).Virtual bronchoscopic navigation(VBN)can guide the bronchoscope by creating virtual images of the bronchial route to the lesion.The diagnostic yield and safety profiles of VBN without fluoroscopy for PPLs have not been evaluated in inexperienced pulmonologist performing EBUS-GS.Methods:Between January 2016 and June 2017,consecutive patients with PPLs referred for EBUS-GS at a single cancer center were enrolled.The diagnostic yield as well as safety profiles was retrospectively analyzed,and our preliminary experience was shared.Results:A total of 109 patients with 109 lesions were included,99(90.8%)lesions were visible on EBUS imaging.According to the procedure time needed to locate the lesion on EBUS,24.8%(27/109)were deemed technically difficult procedures;however,no significant relationships were identified between candidate parameters and technically difficult procedures.The overall diagnosis yield was 74.3%(81/109),and the diagnostic yield of malignancy was 83.7%(77/92).Lesions larger than 20 mm[odds ratio(OR),2.758;95%confidence interval(95%CI),1.077-7.062;P=0.034]and probe of within type(OR,3.174;95%CI,1.151-8.757,P=0.026)were independent factors leading to a better diagnostic yield in multivariate analysis.About 30 practice procedures were needed to achieve a stable diagnostic yield,and the proportion of technically difficult procedures decreased and stabilized after 70 practice procedures.Regarding complications,one patient(0.9%)had intraoperative hemorrhage(100 mL)which was managed under endoscopy.Conclusions:VBN without fluoroscopy guidance is still useful and safe for PPLs diagnosis,especially for malignant diseases when performed by pulmonologist without previous experience of EBUS-GS.VBN may simplify the process of lesion positioning and further multi-center randomized studies are warranted.

Primary pulmonary meningioma and minute pulmonary meningothelial-like nodules: Rare pulmonary nodular lesions requiring more awareness in clinical practice

In this editorial,we comment on an article by Ruan et al published in a recent issue of the World Journal of Clinical Case.Pulmonary meningothelial proliferative lesions,including primary pulmonary meningiomas,minute pulmonary meningothelial-like nodules,and metastatic pulmonary meningiomas are rare pulmonary lesions.These lesions are difficult to differentiate from lung cancers based on clinical and imaging manifestations.Herein,we briefly introduce the clinical,imaging,and pathological characteristics of these lesions and discuss their pathogenesis to strengthen the current understanding of pulmonary meningothelial proliferative lesions in clinical diagnosis and therapy.

Robotic-assisted bronchoscopy in the diagnosis of peripheral pulmonary lesions

More peripheral pulmonary lesions(PPLs)are detected by low-dose helical computed tomography(CT)either in-cidentally or via dedicated lung cancer screening programs.Thus,using methods for safe and accurate diagnosis of these lesions has become increasingly important.Transthoracic needle aspiration(TTNA)and transbronchial lung biopsy(TBLB)are routinely performed during the diagnostic workup for PPLs.However,TTNA often car-ries the risk of pneumothorax,uncontrollable airway hemorrhage,and does not allow mediastinal staging in one procedure.In contrast,traditional TBLB often has a poorer diagnostic yield despite fewer complications.With the ongoing development of technology applied to bronchoscopy,guided bronchoscopy has become widely used and the diagnostic yield of TBLB has improved.Additionally,guided bronchoscopy continues to demonstrate a better safety profile than TTNA.In recent years,robotic-assisted bronchoscopy(RAB)has been introduced and imple-mented in the diagnosis of PPLs.At present,RAB has two platforms that are commercially available:Monarch TM and Ion TM;several other platforms are under development.Both systems differ in characteristics,advantages,and limitations and offer features not seen in previous guided bronchoscopy.Several studies,including cadaveric model studies and clinical trials,have been conducted to examine the feasibility and performance of RAB using these two systems;large multicenter studies are underway.In this review,published experimental results,focus-ing on diagnostic yield and complications of RAB,are analyzed and the potential clinical application of RAB is discussed,which will enable the operators to have a clear overview of RAB.

Pulmonary nodules: optimal slice thickness of CT in revealing bronchial imageology

Objective： The aim of our study was to determine an optimal slice thickness that was efficient in revealing bronchial imageology of pulmonary nodules （PNs） on multi-slice spiral computed tomography （MSCT） images preliminarily. Methods： Fifty-four patients with 62 PNs （diameter 〈 3 cm） underwent multidetector-row computed tomography of the chest in a single-breath-hold technique. The raw data were acquired with a collimation of 0.625 mm. Three sets of contiguous im- ages were reconstructed with 1-, 2-, and 5-mm slice thickness, respectively. Bronchial imageology of SPNs on the CT images presented in 1-, 2-, and 5-mm slice thickness was compared. Using the 1-mm sections as the gold standard, an optimal slice thickness in revealing bronchial imageology of PNs was determined. Results： Bronchial imageology of PNs on the CT images presented in 1 mm slice thickness involved 85 bronchi （35 second-fourth generation bronchi; 50 fifth-eighth generation bronchi）. Bronchial imageology on 2-mm-thick sections was as same as that on I-mm-thick sections in 34 second- fourth generation bronchi. No statistically significant difference in number of second- fourth generation bronchi with same bronchial imageology was found between that on 2-mm-thick images and I-mm-thick images （P = 0.836 〉 0.05）. Bronchial imageology on 5-mm-thick sections was as same as that on 1-mm-thick sections in 24 second-fourth generation bronchi. There was statistically significant difference in number of second-fourth generation bronchi with same bronchial imageology between that on 5-mm-thick images and 1-mm-thick images （P = 0.026 〈 0.05）. Bronchial imageology on 2-mm-thick sections was as same as that on 1-mm-thick sections in 38 fifth-eighth generation bronchi. There was statistically significant difference in number of fifth-eighth generation bronchi with same bronchial imageology between that on 2-mm-thick images and 1-mm- thick images （P = 0.029 〈 0.05）. Bronchial imageology on 5-mm-thick images was as same as that on I-mm-thick images in 31 fifth-eighth generation bronchi. There was statistically significant difference in number of fifth-eighth generation bronchi with same bronchial imageology between that on 5-mm-thick sections and I-mm-thick sections （P = 0.001 〈 0.05）. Conclusion： It is suggested that the use of 2-mm slice thickness is suitable in revealing second- fourth generation bronchi and the use of l-mm slice thickness is suitable in revealing fifth-eighth generation bronchi.

DIFFERENTIAL ULTRASONIC DIAGNOSES OF PULMONARY BENIGN AND MALIGNANT SPACE-OCCUPIED LESIONS OF THE PERIPHERAL TYPE

87 patients with pulmonary space-occupied lesions of the peripheral type which were either adhesive of close to pleura were examined using ultuasonography.Of them,64 cases of lung cancers and 23 of bening lesions were then confirmed by

Contrast enhanced MR angiography in pulmonary sequestration

Objective To evaluate the feasibility of contrast enhanced three-dimensional(3D)magnetic resonance angiography(MRA)in identifying the systemic blood supply in pulmonary sequestration.Methods Three patients who were suspected of pulmonary sequestration were examined by contrast enhanced 3D MRA.MR images were compared with surgical findings.Results Contrast enhanced 3D MRA clearly demonstrated systemic arteries from the descending thoracic aorta supplying the basilar segments of the lower lobe in each case.Pulmonary veins from these segments,which drained into the left atrium in two cases,were also detected.MRA images were consistent with those observed in surgery.Conclusion Contrast enhanced 3D MRA allows accurate diagnosis of pulmonary sequestration and may obviate the need for more invasive investigations.

Extent of Lung Involvement and Serum Cryptococcal Antigen Test in Non-Human Immunodeficiency Virus Adult Patients with Pulmonary Cryptococcosis

Background： Serum cryptococcal antigen （CrAg） test is the most used noninvasive method to detect cryptococcal infection. However, false-negative CrAg test is not uncommon in clinical practice. Then, the aim of this study was to investigate the factors associated with false-negative CrAg test among non-human immunodeficiency virus （HIV） adult patients with pulmonary cryptococcosis and its clinical features. Methods： One hundred and fourteen non-HIV adult patients with pulmonary cryptococcosis, proven by biopsy, were retrospectively reviewed. Finally, 85 patients were enrolled; 56 were CrAg positive （CrAg＋ group） and 29 were negative （CrAg- group）. It was a cross-sectional study. Then, baseline characteristics, underlying diseases, clinical symptoms, laboratory findings, and chest radiological findings were reviewed and analyzed. Chi-square test was used to analyze categorical variable. Odds ratio （OR） was used to measure correlation. Student＇s t-test was obtained to analyze continuous variable. Results： No difference in baseline characteristics, underlying diseases, clinical symptoms, and laboratory findings were found between two groups （P 〉 0.05 in all）. Nevertheless, diffuse extent lesion was 82.1% in CrAg＋ group and 10.3% in CrAg- group （χ2 = 40.34, P〈 0.001; OR = 39.87）. Conclusions： Among patients with limited pulmonary involvement, a negative serum CrAg does not preclude the diagnosis of pulmonary cryptococcosis. However, among patients with extensive pulmonary involvement, serum CrAg is a useful diagnostic tool for pulmonary cryptococcosis. Furthermore, we also noticed that the untypical and mild presentations with extensive pulmonary lesion might be the features of pulmonary cryptococcosis, which needs further investigation.

Solitary pulmonary nodules： comparison of multi-slice computed tomography perfusion study with vascular endothelial growth factor and microvessel density

Background The solitary pulmonary nodule （SPN） is one of the most common findings on chest radiographs. The objectives of clinical practice are to differentiate malignant nodules from benign nodules in the least invasive way and to make a specific diagnosis. This study was aimed to evaluate the correlation between perfusion imaging features and microvessel density （MVD） and vascular endothelial growth factors （VEGF） in SPNs using multi-slice computed tomography （MSCT）; and to provide the theoretical basis for SPN blood flow pattern and blood flow quantitative features. Also, the study called for the discussion of the method＇s clinical application value in the differential diagnosis of benign and malignant SPNs.Methods Sixty-eight patients with SPN underwent multi-location dynamic contrast enhanced （nonionic contrast material was administrated via the antecubital vein at a rate of 4 ml/s） MSCT. Precontrast and postcontrast attenuations on every scan was studied. Perfusion, peak height, and the ratio of the peak height of the SPN to that of the aorta were analyzed. Perfusion was calculated using the maximum gradient of the time-density curves （TDC） and the peak height of the aorta. The quantitative parameters （perfusion, peak height, ratio of peak height of the SPN to that of the aorta） of the blood flow pattern were compared with MVD and the VEGF expression of immunohistochemistry. Results The perfusion peak heights of malignant （（96.15±11.55） HU） and inflammatory （（101.15±8.41） HU） SPNs were significantly higher than those of benign （（47.24±9.15） HU） SPNs （P 〈0.05, P 〈0.05）. Ratios of SPN-to-aorta of malignant and inflammatory SPNs were significantly higher than those of benign SPNs （P 〈0.05, P 〈0.05）. No significant differences were found between the peak height and SPN-to-aorta ratio of malignant SPNs and inflammatory SPNs （P 〉0.05, P 〉0.05）. The precontrast densities of inflammatory SPNs were lower than those of malignant SPNs （P 〈0.05）. Perfusion values of malignant and inflammatory SPNs were significantly higher than those of the benign SPNs （P 〈0.05, P 〈0.05）. The VEGF positive expressions appeared in 32 patients with malignant SPNs and 2 patients with benign SPNs, and the average value of the MVD was higher in patients with malignant SPNs （36.88±6.76） than in patients with either benign （4.51±0.60） or inflammatory （26.11±5.43） SPNs （P 〈0.05, P 〈0.05）. There were statistically significant correlations between the CT perfusion feature and the MVD. The highest correlation was between the peak height of SPN and the MVD （r=0.657, P 〈0.05）.Conclusions Tumor microvessel density and VEGF expression facilitate the exploration of the pathophysiological basis of CT perfusion in SPNs. Multi-slice CT perfusion has shown strong positive correlations with angiogenesis in SPNs.