ABSTRACT
Background@#Inactive or old, healed tuberculosis (TB) on chest radiograph (CR) is often found in high TB incidence countries, and to avoid unnecessary evaluation and medication, differentiation from active TB is important. This study develops a deep learning (DL) model to estimate activity in a single chest radiographic analysis. @*Methods@#A total of 3,824 active TB CRs from 511 individuals and 2,277 inactive TB CRs from 558 individuals were retrospectively collected. A pretrained convolutional neural network was fine-tuned to classify active and inactive TB. The model was pretrained with 8,964 pneumonia and 8,525 normal cases from the National Institute of Health (NIH) dataset. During the pretraining phase, the DL model learns the following tasks: pneumonia vs. normal, pneumonia vs. active TB, and active TB vs. normal. The performance of the DL model was validated using three external datasets. Receiver operating characteristic analyses were performed to evaluate the diagnostic performance to determine active TB by DL model and radiologists. Sensitivities and specificities for determining active TB were evaluated for both the DL model and radiologists. @*Results@#The performance of the DL model showed area under the curve (AUC) values of 0.980 in internal validation, and 0.815 and 0.887 in external validation. The AUC values for the DL model, thoracic radiologist, and general radiologist, evaluated using one of the external validation datasets, were 0.815, 0.871, and 0.811, respectively. @*Conclusion@#This DL-based algorithm showed potential as an effective diagnostic tool to identify TB activity, and could be useful for the follow-up of patients with inactive TB in high TB burden countries.
ABSTRACT
Background@#We analyzed the differences between clinical characteristics and computed tomography (CT) findings in patients with coronavirus disease 2019 (COVID-19) to establish potential relationships with mediastinal lymphadenopathy and clinical outcomes. @*Methods@#We compared the clinical characteristics and CT findings of COVID-19 patients from a nationwide multicenter cohort who were grouped based on the presence or absence of mediastinal lymphadenopathy. Differences between clinical characteristics and CT findings in these groups were analyzed. Univariate and multivariate analyses were performed to determine the impact of mediastinal lymphadenopathy on clinical outcomes. @*Results@#Of the 344 patients included in this study, 53 (15.4%) presented with mediastinal lymphadenopathy. The rate of diffuse alveolar damage pattern pneumonia and the visual CT scores were significantly higher in patients with mediastinal lymphadenopathy than in those without (P < 0.05). A positive correlation between the number of enlarged mediastinal lymph nodes and visual CT scores was noted in patients with mediastinal lymphadenopathy (Spearman’s ρ = 0.334, P < 0.001). Multivariate analysis showed that mediastinal lymphadenopathy was independently associated with a higher risk of intensive care unit (ICU) admission (odds ratio, 95% confidence interval; 3.25, 1.06-9.95) but was not significantly associated with an increased risk of in-hospital death in patients with COVID-19. @*Conclusion@#COVID-19 patients with mediastinal lymphadenopathy had a larger extent of pneumonia than those without. Multivariate analysis adjusted for clinical characteristics and CT findings revealed that the presence of mediastinal lymphadenopathy was significantly associated with ICU admission.
ABSTRACT
MRI has the advantages of having excellent soft-tissue contrast and providing functional information without any harmful ionizing radiation. Although previous technical limitations restricted the use of chest MRI, recent technological advances and expansion of insurance coverage are increasing the demand for chest MRI. Recognizing the need for guidelines on appropriate use of chest MRI in Korean clinical settings, the Korean Society of Radiology has composed a development committee, working committee, and advisory committee to develop Korean chest MRI justification guidelines. Five key questions were selected and recommendations have been made with the evidence-based clinical imaging guideline adaptation methodology.Recommendations are as follows. Chest MRI can be considered in the following circumstances:for patients with incidentally found anterior mediastinal masses to exclude non-neoplastic conditions, for pneumoconiosis patients with lung masses to differentiate progressive massive fibrosis from lung cancer, and when invasion of the chest wall, vertebrae, diaphragm, or major vessels by malignant pleural mesothelioma or non-small cell lung cancer is suspected. Chest MRI without contrast enhancement or with minimal dose low-risk contrast media can be considered for pregnant women with suspected pulmonary embolism. Lastly, chest MRI is recommended for patients with pancoast tumors planned for radical surgery.
ABSTRACT
Background@#Few studies have classified chest computed tomography (CT) findings of coronavirus disease 2019 (COVID-19) and analyzed their correlations with prognosis. The present study aimed to evaluate retrospectively the clinical and chest CT findings of COVID-19 and to analyze CT findings and determine their relationships with clinical severity. @*Methods@#Chest CT and clinical features of 271 COVID-19 patients were assessed. The presence of CT findings and distribution of parenchymal abnormalities were evaluated, and CT patterns were classified as bronchopneumonia, organizing pneumonia (OP), or diffuse alveolar damage (DAD). Total extents were assessed using a visual scoring system and artificial intelligence software. Patients were allocated to two groups based on clinical outcomes, that is, to a severe group (requiring O2 therapy or mechanical ventilation, n = 55) or a mild group (not requiring O2 therapy or mechanical ventilation, n = 216). Clinical and CT features of these two groups were compared and univariate and multivariate logistic regression analyses were performed to identify independent prognostic factors. @*Results@#Age, lymphocyte count, levels of C-reactive protein, and procalcitonin were significantly different in the two groups. Forty-five of the 271 patients had normal chest CT findings. The most common CT findings among the remaining 226 patients were groundglass opacity (98%), followed by consolidation (53%). CT findings were classified as OP (93%), DAD (4%), or bronchopneumonia (3%) and all nine patients with DAD pattern were included in the severe group. Uivariate and multivariate analyses showed an elevated procalcitonin (odds ratio [OR], 2.521; 95% confidence interval [CI], 1.001–6.303, P = 0.048), and higher visual CT scores (OR, 1.137; 95% CI, 1.042–1.236; P = 0.003) or higher total extent by AI measurement (OR, 1.048; 95% CI, 1.020–1.076; P < 0.001) were significantly associated with a severe clinical course. @*Conclusion@#CT findings of COVID-19 pneumonia can be classified into OP, DAD, or bronchopneumonia patterns and all patients with DAD pattern were included in severe group. Elevated inflammatory markers and higher CT scores were found to be significant predictors of poor prognosis in patients with COVID-19 pneumonia.
ABSTRACT
MRI has the advantages of having excellent soft-tissue contrast and providing functional information without any harmful ionizing radiation. Although previous technical limitations restricted the use of chest MRI, recent technological advances and expansion of insurance coverage are increasing the demand for chest MRI. Recognizing the need for guidelines on appropriate use of chest MRI in Korean clinical settings, the Korean Society of Radiology has composed a development committee, working committee, and advisory committee to develop Korean chest MRI justification guidelines. Five key questions were selected and recommendations have been made with the evidence-based clinical imaging guideline adaptation methodology.Recommendations are as follows. Chest MRI can be considered in the following circumstances:for patients with incidentally found anterior mediastinal masses to exclude non-neoplastic conditions, for pneumoconiosis patients with lung masses to differentiate progressive massive fibrosis from lung cancer, and when invasion of the chest wall, vertebrae, diaphragm, or major vessels by malignant pleural mesothelioma or non-small cell lung cancer is suspected. Chest MRI without contrast enhancement or with minimal dose low-risk contrast media can be considered for pregnant women with suspected pulmonary embolism. Lastly, chest MRI is recommended for patients with pancoast tumors planned for radical surgery.
ABSTRACT
Background@#Few studies have classified chest computed tomography (CT) findings of coronavirus disease 2019 (COVID-19) and analyzed their correlations with prognosis. The present study aimed to evaluate retrospectively the clinical and chest CT findings of COVID-19 and to analyze CT findings and determine their relationships with clinical severity. @*Methods@#Chest CT and clinical features of 271 COVID-19 patients were assessed. The presence of CT findings and distribution of parenchymal abnormalities were evaluated, and CT patterns were classified as bronchopneumonia, organizing pneumonia (OP), or diffuse alveolar damage (DAD). Total extents were assessed using a visual scoring system and artificial intelligence software. Patients were allocated to two groups based on clinical outcomes, that is, to a severe group (requiring O2 therapy or mechanical ventilation, n = 55) or a mild group (not requiring O2 therapy or mechanical ventilation, n = 216). Clinical and CT features of these two groups were compared and univariate and multivariate logistic regression analyses were performed to identify independent prognostic factors. @*Results@#Age, lymphocyte count, levels of C-reactive protein, and procalcitonin were significantly different in the two groups. Forty-five of the 271 patients had normal chest CT findings. The most common CT findings among the remaining 226 patients were groundglass opacity (98%), followed by consolidation (53%). CT findings were classified as OP (93%), DAD (4%), or bronchopneumonia (3%) and all nine patients with DAD pattern were included in the severe group. Uivariate and multivariate analyses showed an elevated procalcitonin (odds ratio [OR], 2.521; 95% confidence interval [CI], 1.001–6.303, P = 0.048), and higher visual CT scores (OR, 1.137; 95% CI, 1.042–1.236; P = 0.003) or higher total extent by AI measurement (OR, 1.048; 95% CI, 1.020–1.076; P < 0.001) were significantly associated with a severe clinical course. @*Conclusion@#CT findings of COVID-19 pneumonia can be classified into OP, DAD, or bronchopneumonia patterns and all patients with DAD pattern were included in severe group. Elevated inflammatory markers and higher CT scores were found to be significant predictors of poor prognosis in patients with COVID-19 pneumonia.
ABSTRACT
Current advances in CT techniques allow thorough evaluation of the beating heart. The strengths of cardiac CT relative to echocardiography and magnetic resonance imaging are its high availability in most institutions, rapid production of high-quality images, and outstanding delineation of the anatomy. For many normal variants and pathologic conditions, such as thrombi, masses, and congenital abnormalities of the left atrium, CT findings are sufficient to make a presumptive diagnosis. Assessments of the left atrium and left atrial appendage are particularly important for the management of atrial fibrillation, as various catheter-based procedures are aimed at the mechanical and electrical isolation of these structures. CT offers information crucial to a successful catheter-based procedure or surgery. Therefore, a comprehensive review of the geometry (shape, size, and relative position), along with various CT imaging features of pathologic states, should be provided in radiology reports to be of clinical value.
ABSTRACT
Background@#Lung adenocarcinoma (LUAD) with ground-glass opacity (GGO) can become aggravated, but the reasons for this aggravation are not fully understood. The goal of this study was to analyze the genetic features and causes of progression of GGO LUAD. @*Methods@#LUAD tumor samples and normal tissues were analyzed using an Illumina HiSeq 4000 system. After the tumor mutational burden (TMB) was calculated, the identified mutations were classified as those found only in GGO LUAD, those present only in nonGGO LUAD, and those common to both tissue types. Ten high-frequency genes were selected from each domain, after which protein interaction network analysis was conducted. @*Results@#Overall, 227 mutations in GGO LUAD, 212 in non-GGO LUAD, and 48 that were common to both tumor types were found. The TMB was 8.8 in GGO and 7.8 in non-GGO samples. In GGO LUAD, mutations of FCGBP and SFTPA1 were identified. FOXQ1, IRF5, and MAGEC1 mutations were common to both types, and CDC27 and NOTCH4 mutations were identified in the non-GGO LUAD. Protein interaction network analysis indicated that IRF5 (common to both tissue types) and CDC27 (found in the non-GGO LUAD) had significant biological functions related to the cell cycle and proliferation. @*Conclusion@#In conclusion, GGO LUAD exhibited a higher TMB than non-GGO LUAD. No clinically meaningful mutations were found to be specific to GGO LUAD, but mutations involved in the epithelial-mesenchymal transition or cell cycle were found in both tumor types and in non-GGO tissue alone. These findings could explain the non-invasiveness of GGO-type LUAD.
ABSTRACT
Background@#The Korean Society of Thoracic Radiology (KSTR) recently constructed a nation-wide coronavirus disease 2019 (COVID-19) database and imaging repository, referred to the Korean imaging cohort of COVID-19 (KICC-19) based on the collaborative efforts of its members. The purpose of this study was to provide a summary of the clinico-epidemiological data and imaging data of the KICC-19. @*Methods@#The KSTR members at 17 COVID-19 referral centers retrospectively collected imaging data and clinical information of consecutive patients with reverse transcription polymerase chain reaction-proven COVID-19 in respiratory specimens from February 2020 through May 2020 who underwent diagnostic chest computed tomography (CT) or radiograph in each participating hospital. @*Results@#The cohort consisted of 239 men and 283 women (mean age, 52.3 years; age range, 11–97 years). Of the 522 subjects, 201 (38.5%) had an underlying disease. The most common symptoms were fever (n = 292) and cough (n = 245). The 151 patients (28.9%) had lymphocytopenia, 86 had (16.5%) thrombocytopenia, and 227 patients (43.5%) had an elevated CRP at admission. The 121 (23.4%) needed nasal oxygen therapy or mechanical ventilation (n = 38; 7.3%), and 49 patients (9.4%) were admitted to an intensive care unit.Although most patients had cured, 21 patients (4.0%) died. The 465 (89.1%) subjects underwent a low to standard-dose chest CT scan at least once during hospitalization, resulting in a total of 658 CT scans. The 497 subjects (95.2%) underwent chest radiography at least once during hospitalization, which resulted in a total of 1,475 chest radiographs. @*Conclusion@#The KICC-19 was successfully established and comprised of 658 CT scans and 1,475 chest radiographs of 522 hospitalized Korean COVID-19 patients. The KICC-19 will provide a more comprehensive understanding of the clinical, epidemiological, and radiologic characteristics of patients with COVID-19.
ABSTRACT
Current advances in CT techniques allow thorough evaluation of the beating heart. The strengths of cardiac CT relative to echocardiography and magnetic resonance imaging are its high availability in most institutions, rapid production of high-quality images, and outstanding delineation of the anatomy. For many normal variants and pathologic conditions, such as thrombi, masses, and congenital abnormalities of the left atrium, CT findings are sufficient to make a presumptive diagnosis. Assessments of the left atrium and left atrial appendage are particularly important for the management of atrial fibrillation, as various catheter-based procedures are aimed at the mechanical and electrical isolation of these structures. CT offers information crucial to a successful catheter-based procedure or surgery. Therefore, a comprehensive review of the geometry (shape, size, and relative position), along with various CT imaging features of pathologic states, should be provided in radiology reports to be of clinical value.
ABSTRACT
The coumadin ridge, a ridge of atrial tissue separating the left atrial appendage from the left upper pulmonary vein, is considered to be a normal anatomic variant. A prominent coumadin ridge can be easily mistaken for a tumor or thrombus. In the present case, a left atrial mass was noted on echocardiography and cardiac computed tomography (CT) in a 66-year-old female patient with a history of stroke who experienced chest pain. Therefore, we considered performing a surgery to remove the mass to prevent a recurrence of cerebral infarction, and the mass was confirmed to be a coumadin ridge rather than an actual tumor or thrombus. The findings from the subsequent CT image reconstruction were consistent with the operative findings. We present a surgically confirmed case of coumadin ridge that was consistent with the reconstructed CT image.
ABSTRACT
PURPOSE@#To identify the key CT features of lung parenchyma over time after cardiopulmonary resuscitation (CPR).@*MATERIALS AND METHODS@#In total, 72 patients underwent CT after CPR. Because the median time from return of spontaneous circulation (ROSC) to CT was 1 h 3 min, we divided patients into two groups: ≤ 1 h (group 1) and > 1 h (group 2), based on the ROSC to CT time. We analyzed and compared various lung parenchymal CT findings between groups.@*RESULTS@#Each group included 36 patients. Using statistical analysis, we identified seven statistically significant imaging features. Gradient (p = 0.010), lobular gradient (p = 0.017), diffuse pattern (p = 0.000), upper distribution (p = 0.032), and peripheral portion sparing (p = 0.000) were more common in group 1 than in group 2. Dependent density (p = 0.010) and lobular consolidation (p = 0.010) were more common in group 2 than in group 1.@*CONCLUSION@#The gradient and lobular gradient tended to disappear over time after ROSC. In terms of distribution, a diffuse pattern with upper predominance and peripheral portion sparing tended to disappear over time. However, the dependent density and lobular consolidation tended to increase over time in the lung parenchyma after CPR.
ABSTRACT
On page 148, the Institutional Review Board number was incorrectly numbered as D-1609-071-719. The correct number is D-1608-091-785.
ABSTRACT
OBJECTIVE: To evaluate the preference of observers for image quality of chest radiography using the deconvolution algorithm of point spread function (PSF) (TRUVIEW ART algorithm, DRTECH Corp.) compared with that of original chest radiography for visualization of anatomic regions of the chest. MATERIALS AND METHODS: Prospectively enrolled 50 pairs of posteroanterior chest radiographs collected with standard protocol and with additional TRUVIEW ART algorithm were compared by four chest radiologists. This algorithm corrects scattered signals generated by a scintillator. Readers independently evaluated the visibility of 10 anatomical regions and overall image quality with a 5-point scale of preference. The significance of the differences in reader's preference was tested with a Wilcoxon's signed rank test. RESULTS: All four readers preferred the images applied with the algorithm to those without algorithm for all 10 anatomical regions (mean, 3.6; range, 3.2–4.0; p < 0.001) and for the overall image quality (mean, 3.8; range, 3.3–4.0; p < 0.001). The most preferred anatomical regions were the azygoesophageal recess, thoracic spine, and unobscured lung. CONCLUSION: The visibility of chest anatomical structures applied with the deconvolution algorithm of PSF was superior to the original chest radiography.
Subject(s)
Lung , Prospective Studies , Radiography , Radiography, Thoracic , Spine , ThoraxABSTRACT
Vasculitis, characterized by inflammation of vessel walls, is comprised of heterogeneous clinicopathological entities, and thus poses a diagnostic challenge. The most widely used approach for classifying vasculitides is based on the International Chapel Hill Consensus Conference (CHCC) nomenclature system. Based on the recently revised CHCC 2012, we propose computed tomography (CT) features of vasculitides and a differential diagnosis based on location and morphological characteristics. Finally, vasculitis mimics should be differentiated, because erroneous application of immunosuppressive drugs on vasculitis mimics may be ineffective, even deteriorating. This article presents the utility of CT in the diagnosis and differential diagnosis of vasculitides.
Subject(s)
Classification , Consensus , Diagnosis , Diagnosis, Differential , Inflammation , VasculitisABSTRACT
BACKGROUND AND OBJECTIVES: Preoperative identification of intimal tear site in acute type A dissection will help procedural planning. The objective of this study was to determine the key findings of computed tomography (CT)-based prediction for tear site and compare the accuracy between radiologists and surgeons. SUBJECTS AND METHODS: Multi-detector CT (MDCT) images from 50 patients who underwent surgical repair of type A aortic dissection were retrospectively reviewed by 4 cardiac surgeons with limited experience or by 3 radiologists specialized in cardiovascular imaging. Surgical findings of intimal tear site were used as references. RESULTS: In surgical findings, the locations of intimal tear that were identified in 43 patients included aorta (n=25), ascending with arch (n=7), and arch only (n=11). The rest were retrograde dissections from the tear of descending aorta. Key CT findings that were most frequently found were defect in the intimal flap shadow (30.0+/-4.0 patients/reviewer, accuracy 87.0+/-11.7%) and differential filling of false lumen by phase and location (9.4+/-2.9 patients/reviewer, 84.8+/-10.4%). Surgeons predicted tear site (75.0+/-7.7% vs. 86.7+/-1.2%, p=0.055) and specified flap defect (80.5+/-10.3% vs. 95.7+/-7.4%, p=0.073) with lower accuracy than radiologists. CONCLUSIONS: With MDCT imaging, well-educated surgeons could be accurate in three fourths of cases. There was room for improvement through experience. Considering the substantial possibility of inaccuracy, critical decisions on CT images should be made through thorough reviewing by as many experienced radiologists and surgeons as possible.
Subject(s)
Humans , Aorta , Aorta, Thoracic , Retrospective Studies , TearsABSTRACT
The human heart is a complex organ in which many complicated congenital defects may happen and some of them require surgical intervention. Due to the vast complexity of varied anatomical presentations, establishing an accurate and consistent nomenclature system is utmost important to facilitate effective communication among pediatric cardiologists, cardiothoracic surgeons and radiologists. The Van Praagh segmental approach to the complex congenital heart disease (CHD) was developed in the 1960s and has been used widely as the language for describing complex anatomy of CHD over the decades. It utilizes a systematic and sequential method to describe the cardiac segments and connections which in turn allows accurate, comprehensive and unambiguous description of CHD. It can also be applied to multiple imaging modalities such as echocardiogram, cardiac CT and MRI. The Van Praagh notation demonstrates a group of three letters, with each letter representative for a key embryologic region of cardiac anatomy: the atria, ventricles and great vessels. By using a 3-steps approach, we can evaluate complex CHD precisely and have no difficulties in communicating with other medial colleague. This pictorial essay revisits the logical steps of segmental approach, followed by a pictorial illustration of its application.
Subject(s)
Humans , Congenital Abnormalities , Heart , Heart Defects, Congenital , Logic , Magnetic Resonance ImagingABSTRACT
PURPOSE: To evaluate the prevalence and pattern of perfusion defect (PD) on first-pass stress perfusion MR imaging in relation with the degree of left ventricular hypertrophy (LVH) and late gadolinium-enhancement (LGE) in patients with apical hypertrophic cardiomyopathy (APH). MATERIALS AND METHODS: Cardiac MR imaging with first-pass stress perfusion, cine, and LGE sequence was performed in 26 patients with APH from January 2008 to December 2012. We analyzed a total of 416 segments for LV wall thickness on end-diastolic phase of cine images, and evaluated the number of hypertrophied segment and number of consecutive hypertrophied segment (NCH). We assessed the presence or absence of PD and LGE from all patients. If there was PD, we subdivided the pattern into sporadic (sporadic-PD) or ring (ring-PD). Using univariate logistic method, we obtained the independent predictor for presence of overall PD and ring-PD. RESULTS: PD on stress perfusion MRI was observed in 20 patients (76.9%), 12 of them (60%) showed ring-PD. Maximal LV wall thickness and number of hypertrophied segment were independent predictors for overall PD (all, p < 0.05). NCH with more than 3 segments was an additional independent factor for ring-PD. However, LGE was not statistically related with PD in patients with APH. CONCLUSION: About three quarters of the patients with APH showed PD, most of them represented as ring-PD. LVH degree or distribution was related with pattern of PD, however, LGE was not related with PD. Therefore, the clinical significance of PD in the patients with APH seems to be different from those with non-APH, and further comparison study between the two groups should be carried out.
Subject(s)
Humans , Cardiomyopathy, Hypertrophic , Hypertrophy, Left Ventricular , Magnetic Resonance Imaging , Perfusion , PrevalenceABSTRACT
Antibody-mediated rejection (ABMR) is associated with poor renal allograft survival. It shows poor response to conventional treatment with plasmapheresis, rituximab, and intravenous immunoglobulin. Bortezomib, a proteasome inhibitor used for treatment of multiple myeloma, has recently been reported as a treatment alternative for recipient desensitization and ABMR. A 58-year-old man was diagnosed with mixed-type ABMR with donor specific antibodies and acute T cell-mediated rejection early after kidney transplantation. Conventional therapy was administered, including antithymocyte globulin, plasmapheresis, and rituximab; however, his condition was found to be refractory to these antihumoral therapies. Following administration of bortezomib, his serum creatinine level returned to baseline with stable graft function. His serum creatinine level remains stable at 1.3 mg/dL at 10 months posttransplantation. Bortezomib is effective for treatment of refractory ABMR following kidney transplantation.
Subject(s)
Humans , Middle Aged , Allografts , Antibodies , Antilymphocyte Serum , Bortezomib , Creatinine , Immunoglobulins , Kidney Transplantation , Kidney , Multiple Myeloma , Plasmapheresis , Proteasome Inhibitors , Rituximab , Tissue Donors , Transplantation , TransplantsABSTRACT
OBJECTIVE: We investigated low dose digital tomosynthesis (DT) for the evaluation of the paranasal sinus (PNS), and compared its diagnostic accuracy with a PNS radiography series (XR). MATERIALS AND METHODS: We enrolled 43 patients for whom XR, PNS DT, and OMU CT were performed. We measured effective doses (EDs) of XR, DT, and OMU CT using Monte Carlo simulation software. Two radiologists performed independent observation of both XR and DT. For seven PNSs, they scored anatomic conspicuity of sinuses and confidence on the presence of sinusitis using nine point scales. OMU CT was observed by the third radiologist and the findings were regarded as reference standard. We compared scores for conspicuity and sinusitis confidence between XR and DT. RESULTS: Mean EDs were 29 +/- 6 microSv, 48 +/- 10 microSv, and 980 +/- 250 microSv, respectively, for XR, DT, and CT. Mean scores for conspicuity were 6.3 and 7.4, respectively, for XR and DT. Sensitivity per patient basis for sinusitis detection were 52% and 96%, respectively, for XR and DT in observer 1 (p = 0.001) and 80% and 92% for observer 2 (p = 0.25). Specificities for sinusitis exclusion were 100% for both XR and DT for observer 1 and 89% and 100% for observer 2 (p = 0.50). Accuracies for sinusitis diagnosis were 72% and 98%, respectively, for XR and DT for observer 1 (p = 0.001) and 84% and 95% for observer 2 (p = 0.125). CONCLUSION: Patient radiation dose from low dose DT is comparable with that of PNS XR. Diagnostic sensitivity of DT for sinusitis was superior to PNS XR.