Thin-section Computed Tomography Findings Research Articles

Prediction of Pleural Lavage Cytology According to Thin-Section Computed Tomography in Non–Small-Cell Lung Cancer

BackgroundAlthough the positive rate of preresection pleural lavage cytology (PLC) is low, it is an important indicator of poor prognosis for non–small-cell lung cancer patients with frequent pleural dissemination (PD) recurrence. Thin-section computed tomography (TSCT) can reveal relationships between a primary tumor and the pleura at 1 to 2 mm intervals, and this is associated with visceral pleural invasion (VPI). However, its association with PLC remains unclear. Therefore, we aimed to improve PLC efficiency and predict PD recurrence by understanding the relationship between PLC and preoperative TSCT findings. Patients and MethodsBetween January 2014 and December 2018, we reviewed 978 patients with non–small-cell lung cancer who underwent PLC tests during complete resection surgery. Preoperative TSCT findings were evaluated, and factors with the highest specificity (proportion of patients with radiologically to pathologically diagnosed positive PLC) were investigated. We also evaluated their relationships with VPI and PD recurrence. ResultsPLC positive was identified in 55 (5.6%) of the 978 patients. The two TSCT findings predicting PLC results, “the absence of pleural findings,” ie, tumor not attached to pleura or without pleural tag, and “consolidation-to-tumor ratio ≤0.5”, had a specificity of 100% (95% confidence interval: 90.4%-100%); additionally, all cases with these findings were VPI negative and had no PD recurrence. And 24% of the cohort had either of these findings. ConclusionThe absence of pleural findings and/or consolidation-to-tumor ratio ≤0.5 of primary tumor on preoperative TSCT can predict PLC negativity with very high probability; therefore, PLC can be omitted for such patients.

Air trapping in COVID-19 patients following hospital discharge: retrospective evaluation with paired inspiratory/expiratory thin-section CT

ObjectivesThe study reports our experience with paired inspiration/expiration thin-section computed tomographic (CT) scans in the follow-up of COVID-19 patients with persistent respiratory symptoms.MethodsFrom August 13, 2020, to May 31, 2021, 48 long-COVID patients with respiratory symptoms (27 men and 21 women; median age, 62.0 years; interquartile range: 54.0–69.0 years) underwent follow-up paired inspiration-expiration thin-section CT scans. Patient demographics, length of hospital stay, intensive care unit admission rate, and clinical and laboratory features of acute infection were also included. The scans were obtained on a median of 72.5 days after onset of symptoms (interquartile range: 58.5–86.5) and at least 30 days after hospital discharge. Thin-section CT findings included ground-glass opacity, mosaic attenuation pattern, consolidation, traction bronchiectasis, reticulation, parenchymal bands, bronchial wall thickening, and air trapping. We used a quantitative score to determine the degree of air trapping in the expiratory scans.ResultsParenchymal abnormality was found in 50% (24/48) of patients and included air trapping (37/48, 77%), ground-glass opacities (19/48, 40%), reticulation (18/48, 38%), parenchymal bands (15/48, 31%), traction bronchiectasis (9/48, 19%), mosaic attenuation pattern (9/48, 19%), bronchial wall thickening (6/48, 13%), and consolidation (2/48, 4%). The absence of air trapping was observed in 11/48 (23%), mild air trapping in 20/48 (42%), moderate in 13/48 (27%), and severe in 4/48 (8%). Independent predictors of air trapping were, in decreasing order of importance, gender (p = 0.0085), and age (p = 0.0182).ConclusionsOur results, in a limited number of patients, suggest that follow-up with paired inspiratory/expiratory CT in long-COVID patients with persistent respiratory symptoms commonly displays air trapping.Key Points• Our experience indicates that paired inspiratory/expiratory CT in long-COVID patients with persistent respiratory symptoms commonly displays air trapping.• Iterative reconstruction and dose-reduction options are recommended for demonstrating air trapping in long-COVID patients.

Thin-section computed tomography findings and longitudinal variations of the residual pulmonary sequelae after discharge in patients with COVID-19: a short-term follow-up study.

ObjectivesThis study analyzed and compared CT findings and longitudinal variations after discharge between severe and non-severe coronavirus disease (COVID-19) patients who had residual pulmonary sequelae at pre-discharge.MethodsA total of 310 patients were included and stratified into severe and non-severe COVID-19 groups. Cross-sectional CT features across different time periods (T0: pre-discharge, T1: 1–4 weeks after discharge, T2: 5–8 weeks after discharge, T3: 9–12 weeks after discharge, T4: > 12 weeks after discharge) were compared, and the longitudinal variations of CT findings were analyzed and compared in both groups.ResultsThe cumulative absorption rate of fibrosis-like findings in the severe and non-severe groups at T4 was 24.3% (17/70) and 52.0% (53/102), respectively. In both groups, ground-glass opacity (GGO) with consolidation showed a clear decreasing trend at T1, after which they maintained similar lower levels. The GGO in the severe group showed an increasing trend first at T1 and then decreasing at T4; however, the incidence decreased gradually in the non-severe group. Most fibrosis-like findings showed a tendency to decrease rapidly and then remained stable. Bronchial dilatation in the severe group persisted at an intermediate level.ConclusionsAfter discharge, the characteristics and changing trends of pulmonary sequelae caused by COVID-19 were significantly different between the two groups. Pulmonary sequelae were more serious and recovery was slower in patients with severe/critical disease than in patients with moderate disease. A portion of the fibrosis-like findings were completely absorbed in patients with moderate and severe/critical diseases.Key Points • Lung sequelae were more serious and recovery was slower in severe/critical COVID-19 patients. • Complete absorption of fibrosis-like findings after a short-term follow-up was observed in at least 17/70 (24.3%) of COVID-19 patients with severe/critical disease and 53/102 (52.0%) of COVID-19 patients with moderate disease. • The most common fibrosis-like findings was a parenchymal band; irregular interface was a nonspecific sign of COVID-19, and the percentage of bronchial dilatation in patients with severe/critical disease remained at a relatively stable medium level (range, 31.6 to 47.8%) at all stages. Supplementary InformationThe online version contains supplementary material available at 10.1007/s00330-021-07799-9.

MS07.04 Stage I (Resectable) NSCLC: Surgery

MS07.04 Stage I (Resectable) NSCLC: Surgery

Thin-section computed tomography findings in 104 immunocompetent patients with adenovirus pneumonia.

Background To date, there has been no computed tomography (CT) evaluation of adenovirus pneumonia in a large number of immunocompetent patients. Purpose To describe the thin-section CT findings of immunocompetent patients with adenovirus pneumonia. Material and Methods We prospectively enrolled 104 patients with adenovirus pneumonia from a military hospital. CT scans of each patient were retrospectively and independently assessed by two radiologists for the presence of abnormalities, laterality and zonal predominance of the parenchymal abnormalities, and dominant imaging patterns and their anatomic distributions. Results CT findings included consolidation (n = 92), ground-glass opacity (GGO; n = 82), septal thickening (n = 34), nodules (n = 46), bronchial wall thickening (n = 32), pleural effusion (n = 16), and lymphadenopathy (n = 3). Eighty-four patients (81%) exhibited unilateral parenchymal abnormalities and 57 (57%) exhibited lower lung zone abnormalities. The most frequently dominant CT pattern was consolidation with surrounding GGO (n = 50), with subpleural (70%) and peribronchovascular (94%) distributions. Consolidation-the second-most common pattern (n = 33)-also exhibited subpleural (79%) and peribronchovascular (97%) distributions. The dominant nodule pattern (n = 14) exhibited mixed (64%) and peribronchovascular (100%) distributions. A dominant GGO pattern was only observed in four patients; none had central distribution. Conclusion Although the manifestations of adenovirus pneumonia on CT are varied, we found the most frequent pattern was consolidation with or without surrounding GGO, with subpleural and peribronchovascular distributions. Parenchymal abnormalities were predominantly unilateral and located in the lower lung zone. If dominant consolidation findings are present in immunocompetent patients during the early stages, adenovirus pneumonia should be considered.

Thin-section computed tomography findings of lung adenocarcinoma with inherent metastatic potential.

The solid component of lung ground-glass nodules on thin-section computed tomography (TSCT) reflects cancer cell progression and invasiveness. The purpose of this study was to clarify the cut-off value of preoperative TSCT findings in treating a lesion suspected of being adenocarcinoma and to recognize the timing of surgical resection for lung nodules. We reevaluated the TSCT findings in 392 patients with clinical stage IA lung adenocarcinoma who underwent surgical resection between 2003 and 2007. We identified the clinical parameters that were most useful for predicting recurrence and identified a cut-off level for each parameter. Recurrence was observed in 75 (19%) of 392 patients (median follow-up: 7years). The size of internal consolidation of a lung nodule (SCL) and the ratio of the SCL to the maximum tumor diameter (C/T ratio) were extracted as independent factors that predicted recurrence. Only 1 (0.3%) patient each with a lung nodule C/T ratio ≤0.5 and SCL≤10mm recurred. These conditions were associated with a significantly better overall survival and recurrence-free survival. In patients with clinical stage I lung adenocarcinoma with a C/T ratio ≤0.5 and/or SCL≤10mm on TSCT, surgery is extremely likely to achieve a cure.

Thin-Section Computed Tomography Manifestations During Convalescence and Long-Term Follow-Up of Patients with Severe Acute Respiratory Syndrome (SARS)

BackgroundSARS is not only an acute disease, but also leads to long-term impaired lung diffusing capacity in some survivors. However, there is a paucity of data regarding long-term CT findings in survivors after SARS. The aim of this study was to assess the changes in lung function and lung thin-section computed tomography (CT) features in patients recovering from severe acute respiratory syndrome (SARS), especially the dynamic changes in ground-glass opacity (GGO).Material/MethodsClinical and radiological data from 11 patients with SARS were collected. The serial follow-up thin-section CTs were evaluated at 3, 6, and 84 months after SARS presentation. The distribution and predominant thin-section CT findings of lesions were evaluated.ResultsThe extent of the lesions on the CT scans of the 11 patients decreased at 6 and 84 months compared to 3 months. The number of segments involved on 84-month follow-up CTs was less than those at 6 months (P<0.05). The predominant thin-section CT manifestation at 84 months (intralobular and interlobular septal thickening) was different than that at 6 months, at which GGO was predominant.ConclusionsDuring convalescence after SARS, GGO and intralobular and interlobular septal thickening were the main thin-section CT manifestation. Intralobular and interlobular septal thickening predominated over GGO at 84 months.

Relation Between Thin-Section Computed Tomography and Clinical Findings of Mucinous Adenocarcinoma

Detailed reports on mucinous adenocarcinoma (formerly "mucinous bronchioloalveolar carcinoma") have not been published. We evaluated the correlation between thin-section computed tomography findings and the clinicopathologic characteristics and prognosis of mucinous adenocarcinoma. From April 1997 to March 2008, 45 resected lung carcinomas were diagnosed as mucinous adenocarcinoma. Five cases of multiple lung cancers or ambiguous mucinous adenocarcinoma were excluded. Tumors were classified as "solitary-type" or "pneumonic-type" tumors according to the thin-section computed tomography findings. We evaluated the clinicopathologic characteristics and the epidermal growth factor receptor and KRAS gene mutation statuses and correlated the thin-section computed tomography findings with patient prognoses. Thirty patients had solitary-type and 10 had pneumonic-type tumors. The lesions in 23, 14, and 3 patients were classified as pathologic stage I, stage II, and stage III, respectively. Five patients had adenocarcinoma in situ, 9 had minimally invasive adenocarcinoma, and 26had invasive mucinous adenocarcinoma. Thirteen patients showed recurrences, which were classified as intrapulmonary metastases in all patients. The 5-year overall and relapse-free survival rates were 83.3% and 88.8%, respectively, in patients with solitary-type tumors and 20.0% and 0%, respectively, in patients with pneumonic-type tumors (p < 0.001). The median follow-up time for surviving patients was 81 months. KRAS mutations were detected in 30 patients, but epidermal growth factor receptor mutations were absent in all patients. Our results indicated that thin-section computed tomography findings for mucinous adenocarcinoma were useful in predicting prognosis before surgical resection. Further studies are required to improve the treatment strategy for mucinous adenocarcinoma.

The clinical value and prognostic role of preoperative thin-section computed tomography findings in small-sized adenocarcinomas of the lung (10 mm or less in diameter).

e18514 Background: Thin-section computed tomography (TS-CT) findings of lung cancer were reported to reflect the histopathological findings with some accuracy. However, we do not fully understand t...

Identification of Early T1b Lung Adenocarcinoma Based on Thin-Section Computed Tomography Findings

The aim of this study was to radiologically identify early lung adenocarcinoma in clinical T1bN0M0 lung cancer, based on pathological findings and long-term prognosis. In this study, we reviewed lung nodules findings on thin-section computed tomography in 173 patients with clinical T1bN0M0 lung adenocarcinoma who underwent surgery between 2003 and 2007. The ratio of the size of solid attenuation to the maximum tumor dimension (consolidation/tumor [C/T] ratio) was calculated. We defined two groups of patients by C/T ratio cutoff levels of 0.00, 0.25, 0.50, 0.75, and 1.00 and compared the rates of pathological nonaggressive lung adenocarcinoma, overall survival, and recurrence rates between the groups. The percentages of predominant histological subtypes were compared between two groups divided by the optimal cutoff level. Various clinical factors were analyzed by univariate and multivariate analyses to predict pathological lymph node involvement. The median follow-up period was 62 months. All patients with C/T ratios of 0.5 or less were diagnosed as having pathological nonaggressive adenocarcinomas, and there was no recurrence; their 5-year overall survival rate was 97.4%, which was significantly better than that for patients with C/T ratios of greater than 0.5 (76.2%). None of the ground-glass opacity-predominant tumors were predominantly solid adenocarcinoma with mucin. The C/T ratio of 0.5 or more was an independent predictor of lymph node involvement. In patients with clinical T1bN0M0 disease, the C/T ratio of 0.5 or less identified early lung adenocarcinoma. In patients with the identified early disease, a feasibility study of limited surgery may be warranted.

Discriminative features of thin-slice computed tomography for peripheral intrapulmonary lymph nodes

The use of computed tomography (CT) scans has increased the opportunities to detect small nodular shadows in peripheral lung fields. Intrapulmonary lymph nodes (IPLNs) are sometimes identified among these nodular shadows, and a differential diagnosis is often difficult. However, few descriptions of the CT findings of IPLNs, with regard to their potential for the differential diagnosis of lung cancer, have been published. From 2006 through 2011, 606 patients underwent thoracic surgery for pulmonary nodules. Nine patients (1.5%) had pathologically diagnosed IPLNs. We retrospectively reviewed the clinicopathological features and thin-section CT findings of the patients with IPLNs. We also compared these IPLN patients with 17 patients having small-sized lung cancer. In six cases, the nodules were round, and linear density extending from the IPLNs was visualized in seven nodules. The nodules in IPLNs were located in the lower lobe, and the nodule borders were clearer than those of lung cancers. Six out of nine nodules were round, and linear densities were more easily visualized for the IPLNs. Medical specialists need to be familiar with the discriminative features of thin-slice CT for IPLNs not only to avoid performing unnecessary operations, but also to prevent the mis-staging of lung cancer.

Small peripheral lung adenocarcinoma: CT and histopathologic characteristics and prognostic implications.

Since the introduction of computed tomography (CT), detection of small lung cancer, especially small peripheral adenocarcinoma, is common. Recently, the morphological characteristics, including thin-section CT and pathologic findings, and prognosis of small peripheral lung adenocarcinomas have been studied extensively. The radiologic and microscopic findings correlate well with each other and are closely associated with tumour prognosis. Most importantly, some subtypes of small lung adenocarcinomas with specific CT or pathologic features are curable. Therefore, all defining characteristics (CT, pathologic and prognostic) of this kind of tumour should be integrated to improve our understanding, provide guidelines for management and accurately assess its prognosis.

Thin-Section Computed Tomography Findings of Patients With Acute Streptococcus pneumoniaePneumonia With and Without Concurrent Infectio

PURPOSE: To compare the pulmonary thin-section computed tomography (CT) findings of patients with acute Streptococcus pneumoniae pneumonia with and without concurrent infection.

An animal experiment about early pulmonary candidiasis in immunosuppressive rabbits: thin-section CT images dynamically observed and proved by histopathological results

Early detection and treatment of pulmonary fungal infection in immunocompromised patients has a profound impact on mortality. However, information available about the thin-section computed tomography (CT) findings of Candida pneumonia has largely been limited to isolated cases seen in reviews of various infections and to other acute lung diseases seen in immunocompromised patients. To dynamically observe and evaluate CT findings in immunosuppressed animals with histopathologically confirmed pulmonary candidiasis at the acute stage. Twenty-four New Zealand rabbits were randomly divided into an experimental group (n = 21) and a control group (n = 3). Pulmonary candidiasis was established by C. albicans inoculation via a transtracheal route in immunosuppressed rabbits in the experimental group, and an equivalent amount of normal saline was injected via the same way in the control group. Chest CT scan was performed before and on alternative days after inoculation/injection. Microbiological and pathological results were obtained by autopsy. In the experiment group, pulmonary candidiasis was successfully established in 13 rabbits as confirmed by microbiology and pathology. Areas of air-space consolidation were present in 10 (10/13) rabbits, with lobular distribution in six and lobar or segmental distribution in four, pathologically presenting as bronchopneumonia or hemorrhagic lung infarcts. Areas of ground-glass opacity (GGO) were identified in five (5/13) rabbits, three of which were associated with other abnormalities, presenting as bronchopneumonia or interstitial pneumonitis. Multiple nodules were seen in three (3/13) rabbits. They were clustered around bronchovascular bundles in two rabbits, and subpleural in the remaining one, pathologically presenting as hemorrhagic granulomas. Other less common CT findings included thickening of bronchovascular bundles (n = 3), linear opacity (n = 1), and pneumothorax (n = 1). No abnormality was detected by CT scan and pathological examination in the three rabbits of the control group. Peripheral multiple areas of lobular consolidation and/or GGO representing bronchopneumonia were the most common thin-section CT findings of pulmonary candidiasis at the early stage.

Thin-section Computed Tomography findings before and after azithromycin treatment of neutrophilic reversible lung allograft dysfunction

ObjectivesRecently a novel subgroup of bronchiolitis obliterans syndrome (BOS) has been described in patients after lung transplantation with high neutrophil counts in broncho-alveolar lavage and recovery of lung functional decline with azithromycin treatment. We aimed to describe the thin-section computed tomography (CT) findings of these neutrophilic reversible allograft dysfunction (NRAD) patients before and after azithromycin.MethodsA cohort of 100 lung transplant recipients with BOS were treated with azithromycin and underwent lung function testing, broncho-alveolar lavage and CT before azithromycin treatment and during follow-up. The 200 CT data sets were scored for bronchial dilatation, mucus plugging, centrilobular abnormalities, airway wall thickening, consolidation, ground glass and end-expiratory air trapping.ResultsNRAD was characterized by more centrilobular abnormalities on CT (p = 0.03 for prevalence and p = 0.06 for severity) compared to non-responders. At follow-up NRAD patients showed improvement in all CT abnormalities including air trapping, but the degree of improvement in all CT abnormalities was significantly different between responders and non-responders (who showed progression of bronchus dilatation, consolidation and air trapping).ConclusionsWithin BOS patients those with NRAD differ from azithromycin non-responders by more centrilobular abnormalities on CT before azithromycin and improvement in bronchus dilatation, consolidation and air trapping during treatment.

Growth rate of lung cancer recognized as small solid nodule on initial CT findings

To study the characteristics of lung cancer, appearing as small solid nodules on initial computed tomography (CT) findings, and to determine an appropriate follow-up duration so as to differentiate between malignancy and benign tumor. We analyzed the records of 34 patients who had undergone surgical resection of lung cancer, which appeared as small solid nodules on initial CT findings. We studied the CT findings, volume doubling times (VDT), follow-up durations, pathological and clinical findings. VDT is classified as follows: (1) slow growth group (SGG), with a VDT of more than 700 days and (2) rapid growth group (RGG), with a VDT of less than 700 days. The median VDT of the SGG was 1083 days, and the RGG was 256 days (p<0.01). The median duration for follow-up of the SGG was 1218 days, and 179 days for the RGG. A statistical difference was noted in the follow-up durations (p<0.01). There were no statistical differences in the preoperative thin-section CT (TSCT) findings, or in the pathological findings. The RGG included more patients with smoking histories. The CT findings of RGG tended to reveal changed in base lung field such as emphysema, and lung fibrosis. Generally, lung cancer appearing as small solid nodules on initial CT findings grew rapidly, but there were some cases which displayed slow growth patterns. These cases required follow up for over two years, before diagnosis was possible. We concluded the appropriate maximum followup duration is three years.

Thin-Section CT of the Lungs: The Hinterland of Normal

Thin-section computed tomography (CT) of the lungs was introduced more than 20 years ago and has an established role in the assessment of patients who are known to have, or are suspected of having, diffuse lung disease. Thin-section CT can demonstrate very early disease, sometimes in individuals without symptoms or pulmonary function test abnormalities. Such sensitivity comes at a price because it may be difficult to distinguish thin-section CT findings that lie within the normal range from those that represent early, but important, disease. This review examines particular thin-section CT findings that occupy the gray area between unequivocal health and definite disease, with a particular focus on the effects of cigarette smoking and aging.

Correlations of Thin-Section Computed Tomographic, Histopathological, and Clinical Findings of Adenocarcinoma With a Bubblelike Appearance

We reported that adenocarcinomas with a bubblelike appearance (BLA) appear similar to old inflammation (J Comput Assist Tomogr 2009;33:42-48). The histopathological, clinical, and biological characteristics of adenocarcinomas with BLA need more investigation. We retrospectively reviewed the records of 26 patients who had undergone surgical resection between 1993 and 2008. We analyzed correlations between thin-section computed tomographic (TS-CT), histopathological, and clinical findings. We analyzed epidermal growth factor receptor and K-ras gene mutations. The TS-CT findings are unique with one pattern that was the same in all the 26 cases: (1) polygonal with straight and concave margins, (2) slight peripheral ground-glass opacity areas, (3) 3 or more dilated air bronchograms, and (4) clear pleural indentations. The histopathological findings were identical with our TS-CT findings. The mean tumor doubling time was 1165 days. Epidermal growth factor receptor mutations were observed in 17 cases. There were no K-ras mutations. After resection, the 5-year survival rate is 100%. The adenocarcinomas with BLA have unique TS-CT, histopathological, and clinical findings.

Correlation of 18F-fluorodeoxyglucose uptake on positron emission tomography with Ki-67 index and pathological invasive area in lung adenocarcinomas 30 mm or less in size

Background 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is commonly used to distinguish benign from malignant lesion. Recently, maximum standardized uptake value (SUVmax) on FDG-PET has found to have prognostic value. We examined the relationship between SUVmax and proliferative activities as indicated by maximum diameter of tumor opacity on mediastinal-window images (TOM), Ki-67 index, and diameter of the pathological invasive area in lung adenocarcinomas ≤30 mm. Methods Thin-section computed tomography (TS-CT) and FDG-PET were performed on 140 patients with resectable lung adenocarcinomas ≤30 mm between March 2006 and May 2008. Tumors were classified as air-type or solid-type based on TS-CT findings. In all resected specimens, diameter of the pathological invasive area and Ki-67 index were assessed. Results SUVmax was significantly lower for air-type than for solid-type tumors (0.97 vs. 3.96, p < 0.0001). In solid-type tumors, SUVmax correlated with diameter of TOM ( r = 0.450, p < 0.0001), Ki-67 index ( r = 0.567, p < 0.0001), and diameter of the pathological invasive area ( r = 0.672, p < 0.0001). In multiple regression analysis, SUVmax correlated significantly with Ki-67 index and diameter of the pathological invasive area but not with diameter of TOM. The cut-off value of SUVmax for predicting invasive area >5 mm was determined as 2.15 by ROC analysis, with sensitivity of 88.3% and specificity of 84.6%. Conclusions SUVmax correlated significantly with Ki-67 index and diameter of the pathological invasive area. The present results suggest the potential role of FDG-PET in predicting adenocarcinomas with invasive characteristics.

Imaging Findings of Primary Multidrug-Resistant Tuberculosis

This study was designed to identify and describe thin-section computed tomographic (CT) findings of primary multidrug-resistant tuberculosis (MDR TB) as compared with the findings for drug-sensitive TB. Between October 2002 and December 2007, thin-section chest CT findings of 39 patients with primary MDR TB and 39 patients with drug-sensitive TB were retrospectively reviewed. The frequency and patterns of lung lesions (including centrilobular nodules, large nodules, consolidation, cavity, fibrotic bands, bronchiectasis, calcification, pleural effusion, lymphadenopathy, number of lobes affected by parenchymal lesions, and laterality) were compared. Statistical comparisons were performed with the use of the chi2 and the Mann-Whitney U tests for univariate analysis, and a stepwise logistic regression method was used for multivariate analysis. Based on univariate analysis, bilateral involvement (P < 0.001), segmental or lobar consolidation (P < 0.001), and cavities (P < 0.001) were more frequently seen in primary MDR TB patients. A stepwise logistic regression analysis demonstrated that bilateral involvement of parenchymal lesions (odds ratio, 4.7; 95% confidence interval, 1.4-15.6; P = 0.012) and multiple cavities (odds ratio, 1.7; 95% confidence interval, 1.2-2.5; P = 0.004) were significant CT findings associated with primary MDR TB. The presence of primary MDR TB as detected on a CT scan may help the use of appropriate therapy for infected patients before obtaining a definite diagnosis based on bacteriology.