CT Bronchus Sign Research Articles

Development and validation of diagnostic prediction model for solitary pulmonary nodules

The aim of this study was to develop a simple prediction model for the underlying diagnosis of solitary pulmonary nodules (SPN) based on clinical characteristics and thin-section CT findings. Retrospective analysis was carried out on 452 patients with SPN (113 benign and 339 malignant) smaller than 30 mm, who underwent thin-section CT followed by surgical resection and histological diagnosis. The clinical characteristics were collected from medical records, and radiographic characteristics from thin-section CT findings. The prediction model was determined using multivariate logistic analysis. The prediction model was validated in 148 consecutive patients with undiagnosed SPN, and the diagnostic accuracy of the model was compared with that of an experienced chest radiologist. The prediction model comprised the level of serum CRP, the level of carcinoembryonic antigen, the presence or absence of calcification, spiculation and CT bronchus sign. The areas under the receiver-operating characteristic curve in training and validation sets were 0.966 and 0.840, respectively. The diagnostic accuracies of the prediction model and the experienced chest radiologist for the validation set were 0.858 and 0.905, respectively. The simple prediction model consisted of two biochemical and three radiographic characteristics. The diagnostic accuracy of an experienced chest radiologist was higher compared with the prediction model.

Factors Related to Diagnostic Sensitivity Using an Ultrathin Bronchoscope Under CT Guidance

Background:We investigated factors related to the diagnostic sensitivity of CT-guided transbronchial biopsy (TBB) using an ultrathin bronchoscope and virtual bronchoscopy (VB) navigation for small peripheral pulmonary lesions.Method:We have performed this procedure on 83 patients with 85 small peripheral pulmonary lesions (< 20 mm in diameter). We analyzed the relationship between the diagnostic sensitivity and the location of the lesions, the bronchial generation to which an ultrathin bronchoscope was inserted, and the lesion-bronchial and lesion-pulmonary arterial relationships on high-resolution CT.Results:Fifty-six of the 85 lesions (66%) were diagnosed following CT-guided TBB using an ultrathin bronchoscope with VB navigation. The lesions located in the left superior segment of the lower lobe (S6) had a significantly low diagnostic sensitivity compared to other locations (p < 0.01). When an ultrathin bronchoscope could be inserted to the fifth or greater bronchial generation, the yield was above the average diagnostic sensitivity of 66%. Moreover, not only the patients with the presence of a bronchus leading directly to a lesion (CT-bronchus sign), but also the patients with the presence of a pulmonary artery leading to a lesion (CT-artery sign), had high diagnostic sensitivity (p < 0.01). Multivariate analysis revealed that the location of lesion was an independent predictor of diagnostic sensitivity (p < 0.05).Conclusions:The location of the lesion, the bronchial generation to which an ultrathin bronchoscope was inserted, and the presence of a bronchus as well as a pulmonary artery leading to the lesion were valuable for predicting successful CT-guided TBB using an ultrathin bronchoscope with VB navigation.

Can HRCT Contribute in Decision-Making on Indication for Flexible Bronchoscopy for Solitary Pulmonary Nodules and Masses?

To standardize selection of biopsy procedures for solitary pulmonary nodule and mass (SPNM), we evaluated retrospectively whether high-resolution computed tomography (HRCT) would contribute to decision-making on indication for flexible bronchoscopy (FFB) in 200 SPNM without visible endobronchial abnormalities that underwent HRCT and FFB. A total of 113 SPNM were malignant. For malignancy, the diagnostic yield of FFB was 62.1%. The factors causing low diagnostic yield of FFB are (1) diameter of 25 mm or less (yield 48.9%), (2) distance longer than 40 mm from the inlet of segmental bronchus (yield 50.0%), and (3) no CT bronchus sign (yield 44.9%). If HRCT satisfies two or more of the following conditions—diameter larger than 25 mm, distance from the inlet of segmental bronchus 40 mm or less, positive CT bronchus sign—the likelihood ratios for positive diagnostic FFB range from 1.13 to 4.08; thus, FFB is likely possible to diagnose. The candidate for FFB should be limited to SPNM that satisfies at least two of these three conditions. If SPNM does not satisfy this criterion, likelihood ratios range from 0.18 to 0.64, and another procedure should be considered. On the basis of HRCT, the indication for FFB can be determined.

CT bronchus sign in malignant solitary pulmonary lesions: value in the prediction of cell type.

The aim of this study was to evaluate differences in the prevalence of patterns of CT bronchus sign in malignant solitary pulmonary lesions (SPLs), according to their histologic cell types and with respect to size, location, and degree of cell differentiation. Computed tomography scans of 78 patients, in whom pathologically confirmed malignant SPLs with CT bronchus sign were present, were randomly selected and reviewed by two radiologists under consensus. All 78 were CT scans done using spiral technique with 10-mm collimation and 10-mm reconstruction intervals with enhancement, and 75 included additional high-resolution CT scans. Lesions were classified into four cell types as squamous cell carcinoma (n = 24), small cell carcinoma (n = 12), adenocarcinoma (n = 23), bronchioloalveolar carcinoma (BAC; n = 9), and others (n = 12), into three degrees of differentiation, into three size groups, and according to location (central or peripheral). Patterns of CT bronchus sign were classified into abruptly obstructing (I), patent (II), displacing (III), or tapered narrowing (IV) types. The relationships between the patterns of CT bronchus sign and cell type and degree of cell differentiation were evaluated. Eighty patterns of CT bronchus sign were observed in 78 patients. According to cell type, squamous cell carcinoma showed most often type-I pattern (45.8%) but no type-II pattern, which was the most common pattern observed in BAC (77.8%) and adenocarcinoma (34.8%; p<0.01). Small cell carcinoma showed a varied distribution among the four patterns of CT bronchus sign. According to location, in central squamous cell carcinomas, type-I pattern was more common(55%; p<0.01). Bronchioloalveolar carcinoma showed more peripheral lesions and in both central and peripheral lesions, type-II pattern was significantly more common (100 and 66.7%; p<0.01). In SPLs with CT bronchus sign of obstructing pattern, especially if central location, squamous cell carcinoma should be suspected, whereas in SPLs with patent CT bronchus sign, regardless of the location, the strong possibility of BAC should be considered.

Can Chest CT Decrease the Use of Preoperative Bronchoscopy in the Evaluation of Suspected Bronchogenic Carcinoma?

Fiberoptic bronchoscopy (FOB) is frequently used to diagnose and stage bronchogenic carcinoma (BC). However, the value of FOB in diagnosis/staging BC presenting as a pulmonary nodule or mass (PNM) is controversial. Since chest CT is usually obtained in these patients, it may be used in patient selection for preoperative FOB. Evaluation of the role of chest CT in determining the predictive value of FOB in diagnosing/staging a PNM, by comparing the results of CT and bronchoscopy. Retrospective review of chest CTs and medical records. Consecutive patients with BC between 1992 and 1994 who had diagnostic FOB and CT in our institution, but without radiographic evidence of (1) pulmonary atelectasis, (2) endobronchial tumor or narrowing of the central airways, and (3) the PNM abutting the central airways. Sixty-four patients met the selection criteria. The size of the PNM ranged from 1.5 to 10 cm; the size was < or = 4 cm in 62 patients. FOB provided a diagnosis in 22 patients. Bronchoscopy detected endobronchial lesions in 11 patients (17%); 3 had lesions in more than one lobe. In three patients, the PNM was <3 cm. The radiographically undetected endobronchial tumor increased the tumor stage in only two patients. The "CT bronchus" sign had a positive and negative predictive value of 75% and 68%, respectively. (1) In this study, CT failed to detect endobronchial tumor in 11 of 64 patients (17%). Because of the implications of a new staging system, more studies are necessary before abandoning staging FOB. (2) The CT bronchus sign has a very high positive and negative predictive value in the use of diagnostic FOB and should be used to guide the method of biopsy of a PNM.

CT Bronchus Sign-Guided Bronchoscopic Multiple Diagnostic Procedures in Carcinomatous Solitary Pulmonary Nodules and Masses

CT bronchus sign (BS) designates a bronchus leading directly to a peripheral pulmonary lesion. The objective of this investigation is to determine the contribution of BS-guided bronchoscopic multiple diagnostic procedures (BMDPs) to the diagnostic yield of solitary nodules or masses (SPNMs) suspected of pulmonary carcinoma (PC). A prospective study was carried out in 92 patients with a 2–5 cm diameter SPNM at the level of third to fifth bronchial branching and without endobronchial tumors. Within 10 days after 2-mm CT scans were done, in each of 92, bronchial washing (BW), brushing (BR), transbronchial needle aspiration (TBNA) and transbronchial lung biopsy (TBB) were performed respectively, via fiberoptic bronchoscopy (FB) under fluoroscopic guidance. In 40 (82%) of 49 with BS and in 19 (44%) of 43 without BS, FB established the diagnosis (p < 0.01). In 84 cases of PC, BW, BR, TBNA and TBB provided the diagnostic yields of 4% (3), 26% (22), 57% (48) and 49% (41), respectively; the combined yield reached 68% (57). A metastasis and a tuberculoma were diagnosed exclusively by TBB, and TBNA, respectively. All differences of diagnostic yield except that between TBNA and TBB (p > 0.05) were determined to be significant (p < 0.05). Thoracotomy verified diagnosis in 48 of 59 cases diagnosed and 19 of 33 undiagnosed by FB, and various tissue biopsies or clinical follow-up in 11 diagnosed and 14 undiagnosed by FB. The above data suggest that in the diagnosis of PC as a SPNM at the level of third–fifth bronchial branching, combining the guidance of CT BS, and BMDPs under fluoroscopic guidance can increase the yield considerably.

Lung Cancer With CT-Bronchus Sign: Correlation with CT-findings and the Yield of Bronchoscopic Biopsy

Lung Cancer With CT-Bronchus Sign: Correlation with CT-findings and the Yield of Bronchoscopic Biopsy

Small Bronchogenic Carcinomas Presenting as Solitary Pulmonary Nodules: Bioptic Approach Guided by CT-Positive Bronchus Sign

To evaluate the utility of the CT bronchus sign in making a choice between transbronchial biopsy (TBB) and transthoracic needle aspiration (TTNA) as the first diagnostic procedure in a patient with a solitary pulmonary nodule (SPN), we reviewed the results of TBB and TTNA in 26 patients who had a bronchogenic carcinoma less than 3 cm, studied with thin-section CT. The patients were divided into two groups. Group 1 included ten cases with a third- to fifth-order bronchus sign. Group 2 included two cases with a sixth-order bronchus sign and 14 cases with absence of a bronchus sign. TBB was performed in all the patients; conversely, TTNA was carried out in 22 patients. In group 1, TBB gave a diagnostic yield in eight (80 percent) of ten patients, while TTNA was positive in three (42 percent) of seven patients (p > 0.05). Conversely, in group 2, results of TBB were normal in all the patients, while TTNA gave a diagnosis in 10 (66 percent) of 15 patients (p < 0.05). We think that TBB should be considered the method of choice in diagnosing SPNs associated with a third- to fifth-order bronchus sign; conversely, TTNA is more useful than TBB in diagnosing SPNs in the presence of a more peripheral bronchus sign or with the absence of a bronchus sign. In conclusion, we suggest routine evaluation with thin-section CT of each SPN to optimize diagnostic management.

Solitary Pulmonary Nodules: CT-Bronchoscopic Correlation

The possible contribution of computed tomography (CT) in the management of patients with solitary pulmonary nodules (SPNs) or masses was reviewed retrospectively in 65 patients undergoing fiberoptic bronchoscopy (FOB). Nodules were evaluated by size, location, surface contour, and the presence in cross-section of a bronchus leading to or contained within the nodule or mass, a "positive bronchus sign." Thirty-five lesions were associated with a positive bronchus sign; 21 of 35 (60 percent) were diagnosed endoscopically, (p = .027); of 30 cases with a negative bronchus sign, only ten (30 percent) had a diagnosis made by FOB (p = .034). It is concluded that CT may be of use in the routine evaluation of pulmonary nodules, prior to bronchoscopy, especially in cases for which histologic evaluation is essential, especially to determine the presence or absence of a CT bronchus sign.