Sang Young Oh

Percutaneous CT-Guided Aspiration and Core Biopsy of Pulmonary Nodules Smaller Than 1 cm: Analysis of Outcomes of 305 Procedures From a Tertiary Referral Center

OBJECTIVE We conducted a retrospective analysis to evaluate the diagnostic outcomes of CT-guided aspiration and core biopsy of 305 pulmonary nodules measuring less than 1 cm. MATERIALS AND METHODS We determined the diagnostic yield of using CT-guided aspiration and core biopsy to analyze 305 lesions in 290 patients. Diagnostic performance was evaluated according to the biopsy method, including aspiration alone, core biopsy alone, and combination use, and the consistency of the nodule, including solid, partly solid ground-glass opacity (GGO), and pure GGO. Final diagnoses were established in 268 of the 305 lesions (87.9%). Nondiagnostic biopsy results were obtained for 27 of the 268 lesions (10.1%). RESULTS The overall sensitivity, specificity, positive predictive value, and negative predictive value for the diagnosis of malignancy were 93.1% (148 of 159 lesions), 98.8% (81/82), 99.3% (148/149), and 88.0% (81/92), respectively; diagnostic accuracy was 95.0% (229/241). Using multivariate logistic regression analysis, we found that aspiration alone was a significant independent risk factor associated with diagnostic failure (odds ratio, 3.199; p = 0.001). CONCLUSION The use of CT-guided aspiration and core biopsy resulted in a high diagnostic yield for pulmonary nodules smaller than 1 cm. The use of the aspiration method alone was an independent risk factor associated with diagnostic failure.

Low-dose chest computed tomography with sinogram-affirmed iterative reconstruction, iterative reconstruction in image space, and filtered back projection: studies on image quality.

Objective This study aimed to determine optimal strength of sinogram-affirmed iterative reconstruction (SAFIRE) and to evaluate image quality (IQ) of low-dose chest computed tomography (LDCT) using SAFIRE compared with iterative reconstruction in image space (IRIS) and filtered back projection (FBP). Methods Thirty patients underwent LDCT. Computed tomography (CT) was reconstructed using 5 strengths of SAFIRE (S1-S5), IRIS, and FBP. Objective noise of CT was measured. Two radiologists evaluated CT for subjective IQ, beam-hardening artifacts, and overall IQ. Results Measured noise was highest in FBP, followed by S1, S2, S3, IRIS, S4, and S5. S2 and S3 demonstrated significantly higher overall IQ scores than the other strengths (P < 0.05). Overall IQ and beam-hardening artifacts of S2 and S3 were significantly better than those in FBP and IRIS (P < 0.001). Conclusions S2 or S3 strengths of SAFIRE can be used practically in clinical routines and may have more potential than IRIS and FBP for LDCT with improved IQ.

Detailed analysis of the density change on chest CT of COPD using non-rigid registration of inspiration/expiration CT scans

ObjectivesOne objective was to evaluate the air trapping index (ATI), measured by inspiration/expiration CT, in COPD patients and nonsmokers. Another objective was to assess the association between the pulmonary function test (PFT) and CT parameters such as ATI or other indices, separately in the whole lung, in emphysema, and in hyperinflated and normal lung areas.MethodsOne hundred and thirty-eight COPD patients and 29 nonsmokers were included in our study. The ATI, the emphysema index (EI), the gas trapping index (Exp -856) and expiration/inspiration ratio of mean lung density (E/Iratio of MLD) were measured on CT. The values of the whole lung, of emphysema, and of hyperinflated and normal lung areas were compared and then correlated with various PFT parameters.ResultsCompared with nonsmokers, COPD patients showed a higher ATI in the whole lung and in each lung lesion (all P < 0.05). The ATI showed a higher correlation than EI with FEF25-75%, RV and RV/TLC, and was comparable to Exp -856 and the E/I ratio of MLD. The ATI of emphysema and hyperinflated areas on CT showed better correlation than the normal lung area with PFT parameters.ConclusionsDetailed analysis of density change at inspiration and expiration CT of COPD can provide new insights into pulmonary functional impairment in each lung area.Key Points• COPD patients show significant air trapping in the lung.• The air trapping index is a comparable parameter to other CT indices.• Air trapping of emphysema and hyperinflated lung areas relates to functional loss.• The emphysema area changes more, with less air trapping than other areas.

Texture-Based Automated Quantitative Assessment of Regional Patterns on Initial CT in Patients With Idiopathic Pulmonary Fibrosis: Relationship to Decline in Forced Vital Capacity.

OBJECTIVE The aim of our study was to retrospectively determine predictive factors for a decline in forced vital capacity (FVC) on initial CT using texture-based automated quantification in patients with idiopathic pulmonary fibrosis (IPF). MATERIALS AND METHODS For our study, 193 patients with IPF and 1-year follow-up pulmonary function tests were enrolled in our study. A texture-based automated system used in-house software to quantify six regional CT patterns: normal, ground-glass opacity (GGO), reticular opacity (RO), honeycombing, emphysema, and consolidation. A decline of FVC was defined as a decrease in the initial FVC of more than 10%. RESULTS A decline of FVC occurred in 32 patients: The mean volume of the decline in FVC was 0.43 ± 0.18 (SD) L. The mean extents of GGO, RO, honeycombing, emphysema, and consolidation in all 193 patients were as follows: 12.3% ± 11.9%, 16.8% ± 9.8%, 7.1% ± 6.7%, 3.9% ± 5.5%, and 2.8% ± 0.8%, respectively. A multivariate analysis revealed that RO was the sole independent predictor for a decline in FVC (p = 0.012; adjusted odds ratio, 1.047). ROC analysis showed that the AUC of RO was 0.641 and that the optimal RO cutoff value was 22.05% (sensitivity, 50.0%; specificity, 81.4%; negative predictive value, 89.1%). CONCLUSION RO of less than 22.05% in extent can accurately predict stable IPF at 1-year follow-up in terms of FVC.

Demonstration of Mitral Valve Prolapse with CT for Planning of Mitral Valve Repair

Mitral valve prolapse (MVP), the most frequent cause of severe nonischemic mitral regurgitation, often warrants surgical or interventional valve repair. The severity of mitral regurgitation positively correlates with the development of heart failure and death. Even in patients who are asymptomatic, severe mitral regurgitation causes higher rates of death, heart failure, and atrial fibrillation. Repair procedures for mitral regurgitation have progressed to include leaflet repair, chordal transfer, ring or band annuloplasty, and new percutaneous procedures. In planning for mitral valve repair, detection and localization of mitral valve abnormalities are important. The causes of mitral regurgitation include degenerative mitral valve (eg, prolapsed leaflet, myxomatous degeneration, and Barlow disease [excessive degenerated tissues with elongated chordae]). Cardiac computed tomography (CT) is helpful for depicting mitral valve abnormalities. It allows complete visualization of cardiac anatomic features, including the coronary arteries, paravalvular structures, and cardiac wall motion. This review addresses the role of cardiac CT in depicting anatomic features of the mitral valve, provides a practical method for localizing the exact site of MVP, and discusses the CT findings of various causes of mitral regurgitation. The first step in reconstructing CT images for MVP is to select the best cardiac phase for depicting the anatomic features of the mitral valve. Additional views of the mitral valve then show the specific mitral valve abnormality. This article provides technical tips for demonstrating MVP with CT, as well as imaging results for various causes of MVP and intraoperative findings. Online supplemental material is available for this article.

Assessment of Regional Xenon Ventilation, Perfusion, and Ventilation-Perfusion Mismatch Using Dual-Energy Computed Tomography in Chronic Obstructive Pulmonary Disease Patients.

ObjectivesThe aim of this study was to assess the feasibility of combined xenon-enhanced ventilation (V) and iodine-enhanced perfusion (Q) dual-energy computed tomography (DECT) to evaluate regional V and Q status in patients with chronic obstructive pulmonary disease (COPD). Materials and MethodsCombined V and Q DECT imaging was performed in 52 prospectively enrolled male COPD patients. Virtual noncontrast images, V maps, and Q maps were anatomically coregistered with deformable registration and evaluated using in-house software. After normalization of the V and Q values of each pixel, normalized V and Q, V/Qratio, and VQmin (ie, the smaller of the V and Q in each pixel) maps were generated. For visual analysis, the V/Qratio pattern was determined to be matched, mismatched, or reversed mismatched and compared with the regional disease patterns—emphysema with/without bronchial wall thickening, bronchial wall thickening, or normal parenchyma—in each segment. The mean V, Q, V/Qratio, and VQmin values and the standard deviation of the V/Qratio (V/QSD) of each patient were quantified and compared with pulmonary function test (PFT) parameters using the Pearson correlation test. ResultsSegments with normal parenchyma showed a matched V/Qratio pattern, whereas segments with bronchial wall thickening commonly showed a reversed mismatched V/Qratio pattern. In the emphysema areas, the matched, mismatched, and reversed mismatched patterns were mixed without a dominant pattern. In quantitative analysis, the mean V, Q, VQmin, and V/Qratio values were significantly and positively correlated with PFT parameters (r = 0.290–0.819; P < 0.05). The V/QSD was significantly and negatively correlated with PFT parameters (r = −0.439 to −0.736; P < 0.001). VQmin values showed the best correlation with PFT parameters (r = 0.483–0.819; P < 0.001). ConclusionsVisual and quantitative assessment of the regional V, Q, V/Qratio, and VQmin is feasible with combined V and Q DECT imaging and significantly correlate with PFT results in COPD patients. Assessing disease patterns using conventional computed tomography images may not provide correct evaluation of regional V and Q in COPD patients with emphysema.

Evolving Early Lung Cancers Detected During Follow-Up of Idiopathic Interstitial Pneumonia: Serial CT Features

OBJECTIVE The purpose of this study was to evaluate the CT characteristics of newly developed lung cancer on CT studies obtained during follow-up of idiopathic interstitial pneumonia (IIP) before the appearance of identifiable tumors to the time of detectable lung cancer and thereafter. MATERIALS AND METHODS The study sample included 66 cancers diagnosed in 63 patients with IIP and lung cancer (59 men, four women; median age, 64 years; range, 40-85 years) between October 1998 and July 2012. Two radiologists independently reviewed 193 CT scans, determined the earliest presence of cancer and IIP, and evaluated tumor size, lobar and axial location, shape, and tumor density. Delay in clinical diagnosis and doubling time were measured with first and second follow-up CT examinations. RESULTS Interobserver agreement was good (κ > 0.77). The median tumor size was 17 mm (range, 5-30 mm) for the 46 T1a and 20 T1b cancers. Most of the tumors (42 [63.6%]) were located in the lower lobes. Thirty-five tumors (53.0%) were at the interface between fibrotic cyst and normal lung, and 21 (31.8%) were in the midst of fibrotic lung cysts. Most of the tumors had a round or oval shape (52 [78.8%]) and were solid (62 [93.9%]). The median delay in diagnosis was 46 days (range, 8-760 days). The first median doubling time was 77 days (range, 15-525 days), and the second was 53 days (27-248). CONCLUSION New lung cancers during CT follow-up of IIP usually appear as small solid nodules with a round or oval shape. Most cancers are located at the interface between fibrotic cyst and normal lung or in the midst of fibrotic cysts of the lower lobes of subpleural lung.

Pulmonary sclerosing pneumocytoma of the lung: CT characteristics in a large series of a tertiary referral center.

AbstractThe purpose of this study is to describe the detailed clinical, chest computed tomography (CT), and 18F-fluorodeoxyglucose positron emission tomography (FDG PET) characteristics of the tumor boundary for the diagnosis and investigate the outcome of pulmonary sclerosing pneumocytoma (PSP) using confirmed large data of a tertiary referral center.Confirmed 76 patients were included. We evaluated the findings of CT including 4 CT signs, FDG PET, and histopathology.Most patients had a single lesion (92.1%), smooth boundary (65.8%), and oval shape (65.8%) and the mean diameter was 22.7 mm. The CT signs included marginal pseudocapsule (50%), overlying vessel (26.3%), air gap (2.6%), and halo sign (17.1%). A predominantly solid was the most common histopathologic type. The mean maximum standardized uptake value on FDG PET of 17 patients was 1.8 (range, near 0 or normal tissue metabolism ∼2.9).PSP should be considered in middle-aged women whose CT features show incidental nodule(s), commonly with surrounding ground-glass opacity and characteristic CT signs of the tumor boundary, and hypometabolic uptake on FDG PET. Outcome of patients is excellent.

Bronchoscopic lung volume reduction by endobronchial valve in advanced emphysema: the first Asian report

Purpose Endobronchial valve (EBV) therapy is increasingly being seen as a therapeutic option for advanced emphysema, but its clinical utility in Asian populations, who may have different phenotypes to other ethnic populations, has not been assessed. Patients and methods This prospective open-label single-arm clinical trial examined the clinical efficacy and the safety of EBV in 43 consecutive patients (mean age 68.4±7.5, forced expiratory volume in 1 second [FEV1] 24.5%±10.7% predicted, residual volume 208.7%±47.9% predicted) with severe emphysema with complete fissure and no collateral ventilation in a tertiary referral hospital in Korea. Results Compared to baseline, the patients exhibited significant improvements 6 months after EBV therapy in terms of FEV1 (from 0.68±0.26 L to 0.92±0.40 L; P<0.001), 6-minute walk distance (from 233.5±114.8 m to 299.6±87.5 m; P=0.012), modified Medical Research Council dyspnea scale (from 3.7±0.6 to 2.4±1.2; P<0.001), and St George’s Respiratory Questionnaire (from 65.59±13.07 to 53.76±11.40; P=0.028). Nine patients (20.9%) had a tuberculosis scar, but these scars did not affect target lobe volume reduction or pneumothorax frequency. Thirteen patients had adverse events, ten (23.3%) developed pneumothorax, which included one death due to tension pneumothorax. Conclusion EBV therapy was as effective and safe in Korean patients as it has been shown to be in Western countries. (Trial registration: ClinicalTrials.gov: NCT01869205).

Comparisons of clinical outcomes in patients with and without a preoperative tissue diagnosis in the persistent malignant-looking, ground-glass-opacity nodules.

AbstractTo evaluate the clinical usefulness of surgical resection of persistent malignant-looking ground-glass-opacity nodules (GGN) without a preoperative tissue diagnosis.From September 1998 to November 2011, we retrospectively enrolled 288 patients (126 men, 162 women; mean age, 59.3 years) with lung adenocarcinoma proven by surgery and which appeared as GGN on chest computed tomography (CT, ground-glass-opacity [GGO] proportion >20%). We divided the study subjects into 2 groups: patients with a preoperative tissue diagnosis (PTD group, n = 207) and patients without a preoperative tissue diagnosis (No-PTD group, n = 81). In patients with GGN having GGO ≥ 90% (n = 140), we divided them into 2 groups: PTD group (n = 83) and No-PTD group (n = 57). The clinical and surgical outcomes were compared between the 2 groups.In 204 patients who underwent lobectomy for stage Ia lung cancer, there was no significantly different recurrence-free survival between the 2 groups (P = 0.721). A significantly lower percentage of No-PTD group waited >14 days for surgery (77.8% vs 87.9%, P = 0.030) and were hospitalized for >7 days (56.8% vs 89.9%, P < 0.001). They showed a shorter mean surgery time (136.9 vs 155.0 minutes, P = 0.019). In patients with GGN having GGO ≥ 90%, the results were the same as those of all of the study subjects.No-PTD group can gain benefits perioperatively, showing no different recurrence-free survival with PTD group in stage Ia lung cancer.