Study Protocol for the Evaluation of Multidisciplinary Medication Reconciliation Service in Adult Patients Undergoing Thoracic and Cardiovascular Surgery (The MERITS Study): A Single-Center Controlled before-and-after Study.

Medication reconciliation (MR), which is widely implemented worldwide, aims to improve patient safety to reduce the medication errors during care transition. Despite its widespread use, MR has not yet been implemented in the Republic of Korea, and its effectiveness has not been studied. We aimed to evaluate the impact of a multidisciplinary MR service in older patients undergoing thoracic and cardiovascular surgery. This is a single-center, prospective, controlled, before-and-after study of adult patients taking at least one chronic oral medication. Depending on the period of each patient's participation, they will be allocated to an intervention group or control group. Patients in the intervention group will receive multidisciplinary MR, and those in the control group will receive usual care. The primary outcome is to assess the impact of the MR service on medication discrepancies between the best possible medication history and medication orders at care transition. Secondary outcomes include the incidence rate of medication discrepancies at each transition, the discrepancy rate between the sources of information, the impact of MR on medication appropriateness index score, drug-related problems, 30-day mortality, the emergency department visit rate, readmission rate after discharge, the rate and acceptability of pharmacists' intervention during hospitalization, and patients' satisfaction.

[Immunoglobulin G4-Related Disease in the Thorax: Imaging Findings and Differential Diagnosis]. / 흉부에서 발생한 IgG4 연관 질환: 영상 소견 및 감별진단.

Immunoglobulin G4-related disease (IgG4-RD) is a chronic inflammatory condition involving multiple organs, including the salivary or lacrimal glands, orbit, pancreas, bile duct, liver, kidney, retroperitoneum, aorta, lung, and lymph nodes. It is histologically characterized by tissue infiltration with lymphocytes and IgG4-secreting plasma cells, storiform fibrosis, and obliterative phlebitis. In the thoracic involvement of IgG4-RD, mediastinal lymphadenopathy and perilymphangitic interstitial thickening of the lung are the most common findings. Peribronchovascular and septal thickening and paravertebral band-like soft tissue are characteristic findings of IgG4-RD. Other findings include pulmonary nodules or masses, ground-glass opacity, alveolar interstitial thickening, pleural effusion or thickening, mass in the chest wall or mediastinum, and arteritis involving the aorta and coronary artery. Radiologic differential diagnosis of various malignancies, infections, and inflammatory conditions is needed. In this review, we describe the imaging findings of IgG4-RD and the radiologic differential diagnoses in the thorax.

Sarcoid-Like Reaction after Complete Remission of Malignancy: CT and 18F-FDG PET/CT Features for the Differential Diagnosis from Lymph Node Metastasis.

Purpose: To identify the imaging features indicative of sarcoid-like reactions in patients with intrathoracic lymphadenopathy after complete remission of malignancies. Materials and Methods: This study enrolled five patients with histopathologically confirmed sarcoid-like reactions that developed after cancer remission. The clinical features and findings of CT and 18F-fluorodeoxyglucose (FDG) PET/CT were assessed. Results: The underlying malignancies included breast, nasopharyngeal, colon, and endometrial cancer and lymphoma. The time intervals between complete remission of malignancy and the diagnosis of sarcoid-like reaction ranged from 6 to 78 months. CT findings of sarcoid-like reaction included bilateral hilar and mediastinal lymphadenopathies (n = 5), pulmonary nodules (1-15 mm) with peribronchovascular, fissural, or subpleural distribution, and interlobular interstitial thickening in the lungs (n = 4). 18F-FDG PET/CT revealed hypermetabolic uptake in the mediastinal and hilar lymph nodes and both lungs in the absence of extrathoracic uptake (n = 3). The sarcoid-like reactions resolved in all patients after corticosteroid treatment. Conclusion: In patients with complete remission of malignancies, newly developed bilateral hilar and mediastinal lymphadenopathies with or without pulmonary nodules of perilymphatic distribution, in the absence of recurrence at the primary tumor site and extrathoracic metastasis, may suggest a sarcoid-like reaction. Such cases warrant histologic evaluation of the lymph nodes to prevent unnecessary systemic chemotherapy.

Food Security Status is not Associated with Increased Risk of Metabolic Syndrome in Korean Adults.

Background: It is still uncertain whether food insecurity increases the risk of metabolic syndrome. Recent reports from the United States and developing countries have shown conflicting results on this issue. This study aimed to investigate the association between food security status and metabolic syndrome in Korean adults. Methods: We performed a nationwide population study using data for 18,782 adults obtained from the 2012 to 2015 Korean National Health and Nutrition Examination Surveys. The 18-item Food Security Survey Module was utilized to assess household food security status. We used multiple logistic regression models to determine the association between food security status and metabolic syndrome. Results: The overall prevalence of food insecurity was 8.2% and that of metabolic syndrome was 27.3%. The prevalences of metabolic syndrome were 26.2%, 32.3%, 30.2%, and 28.8% in the high, marginal, low, and very low food security groups, respectively. Food-insecure participants (participants in the low food security and very low food security groups) were significantly more likely to be female, divorced/widowed/separated, and current smokers compared to food-secure participants. Food-insecure participants also had lower incomes, lower education attainments, and lower physical activities (P < 0.05). Compared with the high food security group, the marginal (odds ratio [OR]: 1.34, 95% confidence interval [95% CI]: 1.19-1.50, P < 0.001) and low food security groups (OR: 1.22, 95% CI: 1.04-1.42, P = 0.01) had increased odds of metabolic syndrome in the unadjusted models. However, after controlling for covariates, including age, sex, marital status, education attainment, household income, smoking, alcohol intake, and physical activity, neither marginal food security (adjusted odds ratio [aOR]: 1.02, 95% CI: 0.87-1.19, P = 0.86) nor low food security (aOR: 0.88, 95% CI: 0.71-1.08, P = 0.22) was significantly associated with an increased risk of metabolic syndrome. Conclusions: Contrary to a prior report from the United States, food security status was not significantly associated with the risk of metabolic syndrome in Korean adults.

Imaging Features of Various Benign and Malignant Tumors and Tumorlike Conditions of the Pleura: A Pictorial Review.

Pleural masses may be caused by various conditions, including benign and malignant neoplasms and non-neoplastic tumorlike conditions. Primary pleural neoplasms include solitary fibrous tumor, malignant mesothelioma, and primary pleural non-Hodgkin's lymphoma. Metastatic disease is the most common neoplasm of the pleura and may uncommonly occur in patients with hematologic malignancy, including lymphoma, leukemia, and multiple myeloma. Pleural effusion is usually associated with pleural malignancy. Rarely, pleural malignancy may arise from chronic empyema, and the most common cell type is non-Hodgkin's lymphoma (pyothorax-associated lymphoma). Non-neoplastic pleural masses may be observed in several benign conditions, including tuberculosis, pleural plaques caused by asbestos exposure, and pleural loose body. Herein, we present a review of benign and malignant pleural neoplasms and tumorlike conditions with illustrations of their computed tomographic images.

Spontaneous remission of advanced progressive poorly differentiated non-small cell lung cancer: a case report and review of literature.

BACKGROUND: Spontaneous remission (SR) of cancer is a very rare phenomenon of unknown mechanism. In particular, SR of non-small cell lung cancer (NSCLC) has been scarcely reported. We present the case of a 74-year-old woman with advanced, poorly differentiated NSCLC (highly expressing programmed death ligand-1 [PD-L1]) that progressed despite multiple lines of chemotherapy but then spontaneously remitted. CASE PRESENTATION: The patient presented with hemoptysis and was diagnosed with stage IIIA poorly differentiated NSCLC via bronchoscopic biopsy. She had an unremarkable medical history and moderate performance status. The initial treatment plan was surgery after neoadjuvant chemotherapy. Despite conventional chemotherapy, follow-up chest computed tomography (CT) showed gradual tumor progression and she decided against further treatment after fifth-line chemotherapy. However, the size of lung mass was markedly decreased on follow-up chest CT one year after ceasing chemotherapy. Also, follow-up positron emission tomography images showed decreased metabolic activity in the lung mass and a percutaneous biopsy specimen from the diminished lung mass revealed no viable tumor cells. A diagnosis of SR of NSCLC was confirmed, and the patient was without tumor progression on follow-up nine months later. Later, PD-L1 immunostaining revealed high positivity (> 99%) in initial tumor cells. CONCLUSION: Our case showing SR of poorly advanced NSCLC refractory to multiple lines of chemotherapy suggested the association between immunity and tumor regression.

A functional regulatory variant of MYH3 influences muscle fiber-type composition and intramuscular fat content in pigs.

Muscle development and lipid accumulation in muscle critically affect meat quality of livestock. However, the genetic factors underlying myofiber-type specification and intramuscular fat (IMF) accumulation remain to be elucidated. Using two independent intercrosses between Western commercial breeds and Korean native pigs (KNPs) and a joint linkage-linkage disequilibrium analysis, we identified a 488.1-kb region on porcine chromosome 12 that affects both reddish meat color (a*) and IMF. In this critical region, only the MYH3 gene, encoding myosin heavy chain 3, was found to be preferentially overexpressed in the skeletal muscle of KNPs. Subsequently, MYH3-transgenic mice demonstrated that this gene controls both myofiber-type specification and adipogenesis in skeletal muscle. We discovered a structural variant in the promotor/regulatory region of MYH3 for which Q allele carriers exhibited significantly higher values of a* and IMF than q allele carriers. Furthermore, chromatin immunoprecipitation and cotransfection assays showed that the structural variant in the 5'-flanking region of MYH3 abrogated the binding of the myogenic regulatory factors (MYF5, MYOD, MYOG, and MRF4). The allele distribution of MYH3 among pig populations worldwide indicated that the MYH3 Q allele is of Asian origin and likely predates domestication. In conclusion, we identified a functional regulatory sequence variant in porcine MYH3 that provides novel insights into the genetic basis of the regulation of myofiber type ratios and associated changes in IMF in pigs. The MYH3 variant can play an important role in improving pork quality in current breeding programs.

Risk factors associated with an increase in the size of ground-glass lung nodules on chest computed tomography.

BACKGROUND: The detection rate of ground-glass nodules (GGNs) in the lung has increased with the increased use of low-dose computed tomography (CT) of the chest for cancer screening; however, limited data is available on the natural history, follow-up, and treatment of GGNs. The aim of this study was to identify factors associated with an increase in the size of GGNs. METHODS: A total of 338 patients (mean ages, 59.8 years; males, 35.5%) with 689 nodules who underwent chest CT at our institute between June 2004 and February 2014 were included in this study. The cut-off date of follow-up was August 2018. We analyzed the size, solidity, number, and margins of the nodules compared with their appearance on previous chest CT images. The Cox proportional hazard model was used to identify risk factors associated with nodule growth. RESULTS: The median follow-up period was 21.8 months. Of the 338 patients, 38.5% had a history of malignancy, including lung cancer (8.9%). Among the 689 nodules, the median size of the lesions was 6.0 mm (IQR, 5-8 mm), and the proportion of nodules with size ≥10 mm and multiplicity was 17.1% and 66.3%, respectively. Compared to the nodules without an increase in size, the 79 nodules with an increase in size during the follow-up period were initially larger (growth group, 7.0 mm vs. non-growth group, 6.0 mm; P = 0.027), more likely to have a size ≥10 mm (26.6% vs. 15.9%; P = 0.018), and had less frequent multiplicity (54.4% vs. 67.9%, P = 0.028). In the multivariate analysis, nodule size ≥10 mm (hazard ratio [HR], 2.044; P = 0.005), a patient history of lung cancer (HR: 2.190, P = 0.006), and solitary nodule (HR: 2.499, P < 0.001) were independent risk factors for nodule growth. CONCLUSION: Careful follow-up of GGNs is warranted in patients with a history of malignancy, a large , or a solitary nodule.

Smoking aggravates ventricular arrhythmic events in non-ischemic dilated cardiomyopathy associated with a late gadolinium enhancement in cardiac MRI.

Smoking is known to increase cardiovascular events, but the association and mechanisms between smoking and ventricular arrhythmic events in dilated cardiomyopathy (DCMP) are unknown. The purpose of this study is to investigate the hypothesis that smoking is associated with sudden cardiac death (SCD) and ventricular arrhythmia in DCMP patients. We enrolled 378 patients who underwent cardiovascular magnetic resonance imaging (cMRI) and were diagnosed with DCMP at two general hospitals in Korea. The clinical data and left ventricular late-gadolinium enhancement (LV-LGE) of all patients were analyzed according to being never-smokers or smokers. Smokers were more likely to be male than never-smokers, but there was no other clinical difference between them. Smokers had a greater LV-LGE ratio, and multi-segment involvement of LV-LGEs. Smoking and a low left ventricular (LV) ejection fraction were significant predictors of the presence of LV-LGEs even after adjusting for optimal medical therapy. In addition, smokers had a higher fatal ventricular arrhythmic (FVA; sustained ventricular tachycardia, and ventricular fibrillation) and FVA + SCD, and ex-smokers had a similar FVA to never-smokers during 44.3 ± 36.4 months of follow-up. Finally, smoking independently increased the FVA + SCD even after adjusting for the clinical variables and LV-LGE. Smoking is associated with a multi-segmental involvement of LV-LGE and increased FVA + SCD in DCMP patients when compared to never-smokers.

Emphysematous endocarditis caused by AmpC beta-lactamase-producing Escherichia coli: A case report.

RATIONALE: Infective endocarditis (IE) is a life-threatening disease, mostly caused by gram-positive bacteria. Gram-negative bacteria were identified as a causative organism in relatively small number of cases. Although, antibiotic-resistant Escherichia coli is common cause of gram-negative endocarditis, AmpC beta-lactamase (BL)-harboring E coli is very rare cause of IE. Furthermore, emphysematous endocarditis is also a very rare manifestation of E coli infection. PATIENT CONCERNS: We report a case of 80-year-old female patient presenting with dizziness, fever, and altered mental status, who was finally diagnosed with emphysematous endocarditis caused by E coli harboring an AmpC BL gene. DIAGNOSIS: Her chest computed tomography revealed air bubbles surrounding the annulus of a mitral valve and a transesophageal echocardiogram revealed a hyperechogenic mass fixed on the posteromedial side of the mitral annulus with 2 eccentric mitral regurgitation jets. Blood cultures grew E coli which harbored the DHA-type AmpC BL. The organism belonged to a B2 phylogenic group, and multilocus sequence typing analyses revealed that the strains were of ST-95. INTERVENTIONS: She was treated with meropenem following the resistant profiles, and surgery was recommended by the healthcare professional, but denied by the patient's guardians. She was transferred to another hospital due to a refusal for further treatment. LESSONS: Emphysematous endocarditis is an uncommon complication of E coli bacteremia. Certain phylogenetic groups may be associated with development of E coli endocarditis.

Combined silicosis and mixed dust pneumoconiosis with rapid progression: A case report and literature review.

BACKGROUND: Rapidly progressive pneumoconiosis (RPP) occasionally occurs in coal workers, particularly those with high exposure to silica. Here, we report the case of a 64-year-old male miller with RPP. CASE SUMMARY: The patient had a persistent cough for one month and had been clinically diagnosed with pulmonary tuberculosis in 2011. He worked in a stone processing factory from the ages of 20 through 37 and has owned his own mill for the past 25 years. His chest radiograph showed significant increases in the size and number of lung nodules since his last follow-up in 2013. By percutaneous needle lung biopsy, the nodular lesions showed diffuse infiltration of phagocytic macrophages and birefringent crystals by polarizing microscopy. He was finally diagnosed with RPP of mixed dust pneumoconiosis combined with silicosis. CONCLUSION: In this case, mixed dust pneumoconiosis with silicosis might be accelerated by persistent exposure to grain dust from working in a mill environment.

Peroxiredoxin1, a novel regulator of pronephros development, influences retinoic acid and Wnt signaling by controlling ROS levels.

Peroxiredoxin1 (Prdx1) is an antioxidant enzyme belonging to the peroxiredoxin family of proteins. Prdx1 catalyzes the reduction of H2O2 and alkyl hydroperoxide and plays an important role in different biological processes. Prdx1 also participates in various age-related diseases and cancers. In this study, we investigated the role of Prdx1 in pronephros development during embryogenesis. Prdx1 knockdown markedly inhibited proximal tubule formation in the pronephros and significantly increased the cellular levels of reactive oxygen species (ROS), which impaired primary cilia formation. Additionally, treatment with ROS (H2O2) severely disrupted proximal tubule formation, whereas Prdx1 overexpression reversed the ROS-mediated inhibition in proximal tubule formation. Epistatic analysis revealed that Prdx1 has a crucial role in retinoic acid and Wnt signaling pathways during pronephrogenesis. In conclusion, Prdx1 facilitates proximal tubule formation during pronephrogenesis by regulating ROS levels.

Risk factors associated with treatment refusal in lung cancer.

BACKGROUND: The incidence of lung cancer is increasing with longer life expectancy. Refusal of active treatment for cancer is prone to cause patients to experience more severe symptoms and shorten survival. The purpose of this study was to define the factors related to refusal or abandonment of active therapy in lung cancer. METHODS: We retrospectively reviewed the data of 617 patients from medical records from 2010 to 2014. Two groups were formed: 149 patients who refused anti-cancer treatment and allowed only palliative care were classified into the non-treatment group, while the remaining 468 who received anti-cancer treatment were classified into the treatment group. RESULTS: The groups differed significantly in age, employment, relationship status, number of offspring, educational status, body mass index, presence of chest and systemic symptoms, Charlson Comorbidity Index, Eastern Cooperative Oncology Group score, and tumor node metastasis stage ( P < 0.05). In logistic regression analysis, age (odds ratio [OR] 1.10, 95% confidence interval [CI] 1.07-1.13), educational status lower than high school (OR 1.95, 95% CI 1.2-3.2), no history of surgery (OR 2.29, 95% CI 1.4-3.7), body mass index < 18.5 (OR 2.49, 95% CI 1.3-4.7), and a high Eastern Cooperative Oncology Group score of 3 or 4 (OR 5.02, 95% CI 2.3-10.8) were significant factors for refusal of cancer treatment. CONCLUSION: Individual factors, such as old age, low educational status, low weight, and poor performance status can influence refusal of cancer treatment in patients with lung cancer, and should be considered prior to consultation with patients.

Radiologic Diagnosis of Asbestosis in Korea.

Asbestosis is the most important change noted in the lung parenchyma after environmental and occupational exposure to asbestos fibers. It is characterized by diffuse interstitial pulmonary fibrosis. In Korea, the incidence of asbestosis will continue to increase for many years to come and the government enacted the Asbestos Damage Relief Law in 2011 to provide compensation to those suffering from asbestos-related diseases. Radiologic evaluation is necessary for diagnosis of asbestosis, and radiologists play a key role in this process. Therefore, it is important for radiologists to be aware of the various imaging features of asbestosis.

US characteristics for the prediction of neoplasm in gallbladder polyps 10 mm or larger.

PURPOSE: To evaluate the characteristics of gallbladder polyps 10 mm or larger to predict a neoplasm in US examinations. MATERIALS AND METHODS: Fifty-three patients with gallbladder polyps ≥ 10 mm with follow-up images or pathologic diagnosis were included in the retrospective study. All images and reports were reviewed to determine the imaging characteristics of gallbladder polyps. Univariate and multivariate analyses were used to evaluate predictors for a neoplastic polyp. RESULTS: A neoplastic polyp was verified in 12 of 53 patients and the mean size was 13.9 mm. The univariate analysis revealed that adjacent gallbladder wall thickening, larger size (≥15 mm), older age (≥57 years), absence of hyperechoic foci in a polyp, CT visibility, sessile shape, a solitary polyp, and an irregular surface were significant predictors for a neoplastic polyp. In the multivariate analysis, larger size (≥15 mm) was a significant predictor for a neoplastic polyp. CONCLUSION: A polyp size ≥15 mm was the strongest predictor for a neoplastic polyp with US. The hyperechoic foci in a polyp and CT visibility would be useful indicators for the differentiation of a neoplastic polyp, in addition to the established predictors. KEY POINTS: • A polyp size ≥15 mm is the strongest predictor for a neoplastic polyp with US. • Hyperechoic foci in a polyp and CT visibility are new predictors. • The rate of malignancy is low in polyps even 10 mm or larger (15.1 %).

CT Findings in People Who Were Environmentally Exposed to Asbestos in Korea.

Asbestos related pleuropulmonary disease has been emerging health problem for recent years. It can cause variable clinical symptoms and radiological abnormalities. However, there has been no report for their characteristics in subjects who were environmentally exposed to asbestos. We reviewed the CT images of 35 people who were environmentally exposed to asbestos in Chungnam province, Korea. The study result showed high incidence of pleural plaque and pulmonary fibrosis on chest CT (94% and 77%, respectively). The common CT findings of lung parenchymal lesions were as follows: centrilobular opacities (94%), subpleural dot-like or branching opacities (80%), interlobular septal thickening (57%), intralobular interstitial thickening (46%), parenchymal bands (43%) and subpleural curvilinear line (29%). There were no significant differences in the prevalence of pulmonary fibrosis and pleural plaques according to sex, age and duration of exposure. In conclusion, pleural plaque and pulmonary fibrosis are common asbestos-related CT finding in the exposed people. Asbestos related lung parenchymal CT findings in the participants with environmental exposure show similar to those observed in the occupational exposure.

Progressive Pulmonary Fibrocystic Changes of Both Upper Lungs in a Patient with Ankylosing Spondylitis.

Ankylosing spondylitis is a chronic inflammatory multisystem disease that primarily affects the axial joints. Pleuropulmonary involvement is an uncommon extra-articular manifestation of ankylosing spondylitis. There is a wide spectrum of pulmonary parenchymal changes in ankylosing spondylitis, beginning in the early stages of the disease and increasing over time. The lesions are usually asymptomatic, and not visible on chest radiographs in early stages. We reported a case of advanced ankylosing spondylitis in a 56-year-old man with progressive pulmonary bullous fibrocystic changes on both upper lobes that were misdiagnosed as tuberculosis in the early stages of the disease.

CT Characteristics of Pleural Plaques Related to Occupational or Environmental Asbestos Exposure from South Korean Asbestos Mines.

OBJECTIVE: This study evaluated the CT characteristics of pleural plaques in asbestos-exposed individuals and compared occupational versus environmental exposure groups. MATERIALS AND METHODS: This study enrolled 181 subjects with occupational exposure and 98 with environmental exposure from chrysotile asbestos mines, who had pleural plaques confirmed by a chest CT. The CT scans were analyzed for morphological characteristics, the number and distribution of pleural plaques and combined pulmonary fibrosis. Furthermore, the CT findings were compared between the occupational and environmental exposure groups. RESULTS: Concerning the 279 subjects, the pleural plaques were single in 2.2% and unilateral in 3.6%, and showed variable widths (range, 1-20 mm; mean, 5.4 ± 2.7 mm) and lengths (5-310 mm; 72.6 ± 54.8 mm). The chest wall was the most commonly involved (98.6%), with an upper predominance on the ventral side (upper, 77.8% vs. lower, 55.9%, p < 0.001) and a lower predominance on the dorsal side (upper, 74.9% vs. lower, 91.8%, p = 0.02). Diaphragmatic involvement (78.1%) showed a right-side predominance (right, 73.8% vs. left, 55.6%, p < 0.001), whereas mediastinal plaques (42.7%) were more frequent on the left (right, 17.6% vs. left, 39.4%, p < 0.001). The extent and maximum length of plaques, and presence and severity of combined asbestosis, were significantly higher in the occupational exposure group (p < 0.05). CONCLUSION: Pleural plaques in asbestos-exposed individuals are variable in number and size; and show a predominant distribution in the upper ventral and lower dorsal chest walls, right diaphragm, and left mediastinum. Asbestos mine workers have a higher extent of plaques and pulmonary fibrosis versus environmentally exposed individuals.

A Pleural Loose Body Mimicking a Pleural Tumor: A Case Report.

We present a rare case of a pleural loose body, thought to be a pedunculated pleural tumor, found incidentally in a 58-year-old female. Computed tomography showed a non-enhancing mass, which migrated along the mediastinum and paravertebral area. Thoracoscopic surgery revealed a 4 cm, soap-like mass that was found to be a fibrin body consisting of hyalinized collagen histopathologically. Mobility and the lack of contrast enhancement of a pleural mass are important clues to diagnosing this benign condition.

Ultra-Low-Dose CT of the Thorax Using Iterative Reconstruction: Evaluation of Image Quality and Radiation Dose Reduction.

OBJECTIVE: The purpose of this study is to assess the image quality and radiation dose reduction of ultra-low-dose CT using sinogram-affirmed iterative reconstruction (SAFIRE). SUBJECTS AND METHODS: This prospective study enrolled 25 patients who underwent three consecutive unenhanced CT scans including low-dose CT (120 kVp and 30 mAs) and two ultra-low-dose CT protocols (protocol A, 100 kVp and 20 mAs; protocol B, 80 kVp and 30 mAs) with image reconstruction using SAFIRE. The image quality and radiation dose reduction were assessed. RESULTS: The mean (± SD) effective radiation dose was 1.06 ± 0.11, 0.44 ± 0.05, and 0.31 ± 0.03 mSv for low-dose CT, ultra-low-dose CT protocol A, and ultra-low-dose CT protocol B, respectively. Overall image quality was determined as diagnostic in 100% of low-dose CT scans, 96% of ultra-low-dose CT protocol A scans, and 88% of ultra-low-dose CT protocol B scans. All patients with nondiagnostic quality images had a body mass index (weight in kilograms divided by the square of height in meters) greater than 25. There was no statistically significant difference in detection frequencies of 14 lesion types among the three CT protocols, but pulmonary emphysema was detected in fewer patients (3/25) in ultra-low-dose CT protocol B scans compared with ultra-low-dose CT protocol A scans (5/25) or low-dose CT scans (6/25). We measured the longest dimensions of 33 small solid nodules (3.8-12.4 mm in long diameter) and found no statistically significant difference in the values afforded by the three CT protocols (p = 0.135). CONCLUSION: Iterative reconstruction allows ultra-low-dose CT and affords acceptable image quality, allowing size measurements of solid pulmonary nodules to be made.